@phdthesis{RodriguezCubillos2018,
  author    = {Rodriguez Cubillos, Andres Eduardo},
  title     = {Understanding the impact of heterozygosity on metabolism, growth and hybrid necrosis within a local Arabidopsis thaliana collection site},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-416758},
  school      = {Universit{\"a}t Potsdam},
  pages     = {106},
  year      = {2018},
  abstract  = {Plants are unable to move away from unwanted environments and therefore have to locally adapt to changing conditions. Arabidopsis thaliana (Arabidopsis), a model organism in plant biology, has been able to rapidly colonize a wide spectrum of environments with different biotic and abiotic challenges. In recent years, natural variation in Arabidopsis has shown to be an excellent resource to study genes underlying adaptive traits and hybridization's impact on natural diversity. Studies on Arabidopsis hybrids have provided information on the genetic basis of hybrid incompatibilities and heterosis, as well as inheritance patterns in hybrids. However, previous studies have focused mainly on global accessions and yet much remains to be known about variation happening within a local growth habitat. In my PhD, I investigated the impact of heterozygosity at a local collection site of Arabidopsis and its role in local adaptation. I focused on two different projects, both including hybrids among Arabidopsis individuals collected around T{\"u}bingen in Southern Germany. The first project sought to understand the impact of hybridization on metabolism and growth within a local Arabidopsis collection site. For this, the inheritance patterns in primary and secondary metabolism, together with rosette size of full diallel crosses among seven parents originating from Southern Germany were analyzed. In comparison to primary metabolites, compounds from secondary metabolism were more variable and showed pronounced non-additive inheritance patterns. In addition, defense metabolites, mainly glucosinolates, displayed the highest degree of variation from the midparent values and were positively correlated with a proxy for plant size. In the second project, the role of ACCELERATED CELL DEATH 6 (ACD6) in the defense response pathway of Arabidopsis necrotic hybrids was further characterized. Allelic interactions of ACD6 have been previously linked to hybrid necrosis, both among global and local Arabidopsis accessions. Hence, I characterized the early metabolic and ionic changes induced by ACD6, together with marker gene expression assays of physiological responses linked to its activation. An upregulation of simple sugars and metabolites linked to non-enzymatic antioxidants and the TCA cycle were detected, together with putrescine and acids linked to abiotic stress responses. Senescence was found to be induced earlier in necrotic hybrids and cytoplasmic calcium signaling was unaffected in response to temperature. In parallel, GFP-tagged constructs of ACD6 were developed. This work therefore gave novel insights on the role of heterozygosity in natural variation and adaptation and expanded our current knowledge on the physiological and molecular responses associated with ACD6 activation.},
  language  = {en}
}
@phdthesis{Ullmann2018,
  author    = {Ullmann, Wiebke},
  title     = {Understanding animal movement behaviour in dynamic agricultural landscapes},
  doi       = {10.25932/publishup-42715},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427153},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vii, 183},
  year      = {2018},
  abstract  = {The movement of organisms has formed our planet like few other processes. Movements shape populations, communities, entire ecosystems, and guarantee fundamental ecosystem functions and services, like seed dispersal and pollination. Global, regional and local anthropogenic impacts influence animal movements across ecosystems all around the world. In particular, land-use modification, like habitat loss and fragmentation disrupt movements between habitats with profound consequences, from increased disease transmissions to reduced species richness and abundance. However, neither the influence of anthropogenic change on animal movement processes nor the resulting effects on ecosystems are well understood. Therefore, we need a coherent understanding of organismal movement processes and their underlying mechanisms to predict and prevent altered animal movements and their consequences for ecosystem functions. In this thesis I aim at understanding the influence of anthropogenically caused land-use change on animal movement processes and their underlying mechanisms. In particular, I am interested in the synergistic influence of large-scale landscape structure and fine-scale habitat features on basic-level movement behaviours (e.g. the daily amount of time spend running, foraging, and resting) and their emerging higher-level movements (home range formation). Based on my findings, I identify the likely consequences of altered animal movements that lead to the loss of species richness and abundances. The study system of my thesis are hares in agricultural landscapes. European brown hares (Lepus europaeus) are perfectly suited to study animal movements in agricultural landscapes, as hares are hermerophiles and prefer open habitats. They have historically thrived in agricultural landscapes, but their numbers are in decline. Agricultural areas are undergoing strong land-use changes due to increasing food demand and fast developing agricultural technologies. They are already the largest land-use class, covering 38\% of the world's terrestrial surface. To consider the relevance of a given landscape structure for animal movement behaviour I selected two differently structured agricultural landscapes - a simple landscape in Northern Germany with large fields and few landscape elements (e.g. hedges and tree stands), and a complex landscape in Southern Germany with small fields and many landscape elements. I applied GPS devices (hourly fixes) with internal high-resolution accelerometers (4 min samples) to track hares, receiving an almost continuous observation of the animals' behaviours via acceleration analyses. I used the spatial and behavioural information in combination with remote sensing data (normalized difference vegetation index, or NDVI, a proxy for resource availability), generating an almost complete idea of what the animal was doing when, why and where. Apart from landscape structure (represented by the two differently structured study areas), I specifically tested whether the following fine-scale habitat features influence animal movements: resource, agricultural management events, habitat diversity, and habitat structure. My results show that, irrespective of the movement process or mechanism and the type of fine-scale habitat features, landscape structure was the overarching variable influencing hare movement behaviour. High resource variability forces hares to enlarge their home ranges, but only in the simple and not in the complex landscape. Agricultural management events result in home range shifts in both landscapes, but force hares to increase their home ranges only in the simple landscape. Also the preference of habitat patches with low vegetation and the avoidance of high vegetation, was stronger in the simple landscape. High and dense crop fields restricted hare movements temporarily to very local and small habitat patch remnants. Such insuperable barriers can separate habitat patches that were previously connected by mobile links. Hence, the transport of nutrients and genetic material is temporarily disrupted. This mechanism is also working on a global scale, as human induced changes from habitat loss and fragmentation to expanding monocultures cause a reduction in animal movements worldwide. The mechanisms behind those findings show that higher-level movements, like increasing home ranges, emerge from underlying basic-level movements, like the behavioural modes. An increasing landscape simplicity first acts on the behavioural modes, i.e. hares run and forage more, but have less time to rest. Hence, the emergence of increased home range sizes in simple landscapes is based on an increased proportion of time running and foraging, largely due to longer travelling times between distant habitats and scarce resource items in the landscape. This relationship was especially strong during the reproductive phase, demonstrating the importance of high-quality habitat for reproduction and the need to keep up self-maintenance first, in low quality areas. These changes in movement behaviour may release a cascade of processes that start with more time being allocated to running and foraging, resulting into an increased energy expenditure and may lead to a decline in individual fitness. A decrease in individual fitness and reproductive output will ultimately affect population viability leading to local extinctions. In conclusion, I show that landscape structure has one of the most important effects on hare movement behaviour. Synergistic effects of landscape structure, and fine-scale habitat features, first affect and modify basic-level movement behaviours, that can scales up to altered higher-level movements and may even lead to the decline of species richness and abundances, and the disruption of ecosystem functions. Understanding the connection between movement mechanisms and processes can help to predict and prevent anthropogenically induced changes in movement behaviour. With regard to the paramount importance of landscape structure, I strongly recommend to decrease the size of agricultural fields and increase crop diversity. On the small-scale, conservation policies should assure the year round provision of areas with low vegetation height and high quality forage. This could be done by generating wildflower strips and additional (semi-) natural habitat patches. This will not only help to increase the populations of European brown hares and other farmland species, but also ensure and protects the continuity of mobile links and their intrinsic value for sustaining important ecosystem functions and services.},
  language  = {en}
}
@phdthesis{Koc2018,
  author    = {Ko{\c{c}}, Azize},
  title     = {Ultrafast x-ray studies on the non-equilibrium of the magnetic and phononic system in heavy rare-earths},
  doi       = {10.25932/publishup-42328},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-423282},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ii, 117},
  year      = {2018},
  abstract  = {In this dissertation the lattice and the magnetic recovery dynamics of the two heavy rare-earth metals Dy and Gd after femtosecond photoexcitation are described. For the investigations, thin films of Dy and Gd were measured at low temperatures in the antiferromagnetic phase of Dy and close to room temperature in the ferromagnetic phase of Gd. Two different optical pump-x-ray probe techniques were employed: Ultrafast x-ray diffraction with hard x-rays (UXRD) yields the structural response of heavy rare-earth metals and resonant soft (elastic) x-ray diffraction (RSXD), which allows measuring directly changes in the helical antiferromagnetic order of Dy. The combination of both techniques enables to study the complex interaction between the magnetic and the phononic subsystems.},
  language  = {en}
}
@phdthesis{Sander2018,
  author    = {Sander, Mathias},
  title     = {Ultrafast tailored strain fields in nanostructures},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417863},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvii, 119},
  year      = {2018},
  abstract  = {This publication based thesis, which consists of seven published articles, summarizes my contributions to the research field of laser excited ultrafast structural dynamics. The coherent and incoherent lattice dynamics on microscopic length scales are detected by ultrashort optical and X-ray pulses. The understanding of the complex physical processes is essential for future improvements of technological applications. For this purpose, tabletop soruces and large scale facilities, e.g. synchrotrons, are employed to study structural dynamics of longitudinal acoustic strain waves and heat transport. The investigated effects cover timescales from hundreds of femtoseconds up to several microseconds. The main part of this thesis is dedicated to the investigation of tailored phonon wave packets propagating in perovskite nanostructures. Tailoring is achieved either by laser excitation of nanostructured bilayer samples or by a temporal series of laser pulses. Due to the propagation of longitudinal acoustic phonons, the out-of-plane lattice spacing of a thin film insulator-metal bilayer sample is modulated on an ultrafast timescale. This leads to an ultrafast modulation of the X-ray diffraction efficiency which is employed as a phonon Bragg switch to shorten hard X-ray pulses emitted from a 3rd generation synchrotron. In addition, we have observed nonlinear mixing of high amplitude phonon wave packets which originates from an anharmonic interatomic potential. A chirped optical pulse sequence excites a narrow band phonon wave packet with specific momentum and energy. The second harmonic generation of these phonon wave packets is followed by ultrafast X-ray diffraction. Phonon upconversion takes place because the high amplitude phonon wave packet modulates the acoustic properties of the crystal which leads to self steepening and to the successive generation of higher harmonics of the phonon wave packet. Furthermore, we have demonstrated ultrafast strain in direction parallel to the sample surface. Two consecutive so-called transient grating excitations displaced in space and time are used to coherently control thermal gradients and surface acoustic modes. The amplitude of the coherent and incoherent surface excursion is disentangled by time resolved X-ray reflectivity measurements. We calibrate the absolute amplitude of thermal and acoustic surface excursion with measurements of longitudinal phonon propagation. In addition, we develop a diffraction model which allows for measuring the surface excursion on an absolute length scale with sub-{\"A}angstr{\"o}m precision. Finally, I demonstrate full coherent control of an excited surface deformation by amplifying and suppressing thermal and coherent excitations at the surface of a laser-excited Yttrium-manganite sample.},
  language  = {en}
}
@phdthesis{Aktan2018,
  author    = {Aktan, Oktay},
  title     = {Turkish football clubs in Berlin},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-413616},
  school      = {Universit{\"a}t Potsdam},
  pages     = {221},
  year      = {2018},
  abstract  = {Es gibt in Berlin eine einzigartige Vereinslandschaft im Amateur - und semiprofessionellen Fußballsport, in der einst von t{\"u}rkischen Migranten gegr{\"u}ndete Vereine einen festen Platz einnehmen. Fußballsport bietet einen sozialen Raum f{\"u}r Jugendliche verschiedener kultureller, ethnischer und religi{\"o}ser Herkunft, in dem Gruppen gebildet werden, um gegen einander zu konkurrieren. Ebenso er{\"o}ffnet Fußball dem Einzelnen die M{\"o}glichkeit, die G{\"u}ltigkeit und Relevanz von Vorurteilen und von g{\"a}ngigen Stereotypisierungen anderer Gruppen im Spielalltag einer st{\"a}ndigen Pr{\"u}fung zu unterziehen. Fußballspieler k{\"o}nnen sich sowohl zwischen multi-kulturellen als auch mono-ethnischen Gruppenkonstellationen, in einigen F{\"a}llen auch in transnationalen Konstellationen bewegen, womit sie dabei wesentlich an der Sinngebung ihrer eigenen sozialen Zugeh{\"o}rigkeit mitwirken, die sich aus dem Spannungsfeld von Selbst- und Fremdwahrnehmungsmustern ergibt. In Folge dessen werden in diesem Raum Anerkennungsmechanismen konstituiert. Die vorliegende Dissertation befasst sich mit dem allt{\"a}glichen Leben von t{\"u}rkisch-st{\"a}mmigen, jugendlichen Amateur- und semiprofessionellen Fußballspielern (delikanli), sowie von anderen sozialen Akteuren der t{\"u}rkischen Fußballwelt, wie zum Beispiel „{\"a}ltere" Fußballspieler (agbi) und Fußballtrainer (hoca). Hauptanliegen der Arbeit war die Rekonstruktion kollektiver Wahrnehmungs-, Deutungs - und Handlungsmuster von Mitgliedern t{\"u}rkischer Fußballvereine im allgemeinen und ihrer Selbstdarstellung aber auch ihrer Wahrnehmung der „Anderen" im besonderen. Mittels dieser Studie sollte nachvollzogen werden, ob und inwiefern sich traditionelle soziale Verhaltensmuster der gew{\"a}hlten Gruppe im technisch regulierten und stark Konkurrenz-orientierten Handlungsraum widerspiegeln und die reziproken Beziehungen zwischen dem „Selbst" und den „Anderen" regulieren. Dabei wurde die Relevanz von herkunftsbezogenen Stereotypisierungen und Vorurteilen in der kollektiven Konstitution von Selbstwahrnehmungen und Fremdverstehen im partikularen sozialen Feld (Bourdieu, 2001) des Fußballs rekonstruiert. In dieser Arbeit wurde dar{\"u}ber hinaus beleuchtet, welche Rolle t{\"u}rkische Fußballvereine auf der einen Seite bei der Entstehung sozialer Raumzugeh{\"o}rigkeit zu den Stadtquartieren in Berlin einnehmen und welche Art von Mechanismen der sozialen Integration sie in diesen Vereinen herstellen. Auf der anderen Seite wurde hinterfragt, inwiefern sie zur sozialen Koh{\"a}sion zwischen diversen Kulturen beitragen. Daher wurde gepr{\"u}ft, ob und inwiefern die negativ konnotierte ethnozentrische Wahrnehmung von „Differenz" (Bielefeld, 1998), die als soziales Konstrukt zwischen autochthonen und allochthonen Gruppen hergestellt wird, durch das Engagement der Vereinsakteure einen konstruktiven Wandel erf{\"a}hrt. {\"U}bergeordnetes Ziel all dieser Forschungsfragen war es, ein fundiertes Verst{\"a}ndnis {\"u}ber die Rolle von t{\"u}rkischen Fußballvereinen als soziale Mechanismen zu erlangen und deren Funktionsweise bei der Konstitution von Anpassungsstrategien in diesem sozialen Feld untersuchen. Detailliert wurde diese Rolle unter der Konzeptualisierung von sozialen Positionierungsmuster betrachtet, die als Gef{\"u}ge von Deutungen des Allt{\"a}glichen verstanden werden, das individuelle und kollektive Handlungsmuster und implizit Muster des Fremdverstehens sowie des othering im Migrationskontext reguliert. Eine Rekonstruktion der sozialen Positionierungsmuster bietet eine eingehende soziologische Untersuchung dieser Teilnehmergruppe, die zudem Aufschluss {\"u}ber die Bedeutung und das Verst{\"a}ndnis von ethnischer Zugeh{\"o}rigkeit f{\"u}r letztere gibt. Neben umfangreicher Feldbeobachtung wurden in dieser qualitativen Studie mit Spielern verschiedener Vereine insgesamt zehn Gruppendiskussionen (Bohnsack, 2004) innerhalb ihrer Mannschaften zu gemeinsamen allt{\"a}glichen Erlebnissen und Erfahrungen durchgef{\"u}hrt, aufgezeichnet und mittels sozialwissenschaftlichem hermeneutischem Verfahren (Soeffner, 2004) interpretiert. Auch mit anderen Vereinsmitgliedern, d. h. mit Trainern bzw. hoca, Vorsitzenden, Managern und Sponsoren wurden jeweils zehn narrative und sieben biographische Einzelinterviews sowie sieben Experteninterviews durchgef{\"u}hrt. Deren Analyse erlaubt es, die Rolle dieser Mitglieder sowie wirkende Autorit{\"a}tsmechanismen und kollektiv konstituierte Verhaltensmuster innerhalb der gesamten Vereinsgruppe zu rekonstruieren. Dabei wurde bezweckt, die Gesamtheit des sozialen Netzwerkes bzw. die Beziehungsschemata innerhalb der t{\"u}rkischen Fußballvereine Berlins zu verdeutlichen. In der Arbeit werden zwei Standpunkte der theoretischen Auseinandersetzung verwendet. Auf der einen Seite wird die Lebensweltanalyse (Sch{\"u}tz und Luckmann, 1979, 1990) angewendet, um das soziale Erbe der in der Vergangenheit gesellschaftlich konstituierten Titulierung „Menschen mit Migrationshintergrund" zu rekonstruieren, bzw. den Einfluss dieser sozialen Reproduktion auf die Wahrnehmungs-, Deutungs- und Handlungsmuster der Akteure zu untersuchen. Auf der anderen Seite wird die soziale Wirkung der tats{\"a}chlichen, allt{\"a}glichen Erfahrungsschemata im sozialen Feld des Fußballs auf die Selbstpositionierungen der Akteure mittels Goffmanscher Rahmenanalyse (Goffman, 1980) herausgearbeitet.},
  language  = {en}
}
@phdthesis{Zakarias2018,
  author    = {Zakari{\´a}s, Lilla},
  title     = {Transfer effects after working memory training in post-stroke aphasia},
  doi       = {10.25932/publishup-42360},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-423600},
  school      = {Universit{\"a}t Potsdam},
  pages     = {178},
  year      = {2018},
  abstract  = {Background: Individuals with aphasia after stroke (IWA) often present with working memory (WM) deficits. Research investigating the relationship between WM and language abilities has led to the promising hypothesis that treatments of WM could lead to improvements in language, a phenomenon known as transfer. Although recent treatment protocols have been successful in improving WM, the evidence to date is scarce and the extent to which improvements in trained tasks of WM transfer to untrained memory tasks, spoken sentence comprehension, and functional communication is yet poorly understood. Aims: We aimed at (a) investigating whether WM can be improved through an adaptive n-back training in IWA (Study 1-3); (b) testing whether WM training leads to near transfer to unpracticed WM tasks (Study 1-3), and far transfer to spoken sentence comprehension (Study 1-3), functional communication (Study 2-3), and memory in daily life in IWA (Study 2-3); and (c) evaluating the methodological quality of existing WM treatments in IWA (Study 3). To address these goals, we conducted two empirical studies - a case-controls study with Hungarian speaking IWA (Study 1) and a multiple baseline study with German speaking IWA (Study 2) - and a systematic review (Study 3). Methods: In Study 1 and 2 participants with chronic, post-stroke aphasia performed an adaptive, computerized n-back training. 'Adaptivity' was implemented by adjusting the tasks' difficulty level according to the participants' performance, ensuring that they always practiced at an optimal level of difficulty. To assess the specificity of transfer effects and to better understand the underlying mechanisms of transfer on spoken sentence comprehension, we included an outcome measure testing specific syntactic structures that have been proposed to involve WM processes (e.g., non-canonical structures with varying complexity). Results: We detected a mixed pattern of training and transfer effects across individuals: five participants out of six significantly improved in the n-back training. Our most important finding is that all six participants improved significantly in spoken sentence comprehension (i.e., far transfer effects). In addition, we also found far transfer to functional communication (in two participants out of three in Study 2) and everyday memory functioning (in all three participants in Study 2), and near transfer to unpracticed n-back tasks (in four participants out of six). Pooled data analysis of Study 1 and 2 showed a significant negative relationship between initial spoken sentence comprehension and the amount of improvement in this ability, suggesting that the more severe the participants' spoken sentence comprehension deficit was at the beginning of training, the more they improved after training. Taken together, we detected both near far and transfer effects in our studies, but the effects varied across participants. The systematic review evaluating the methodological quality of existing WM treatments in stroke IWA (Study 3) showed poor internal and external validity across the included 17 studies. Poor internal validity was mainly due to use of inappropriate design, lack of randomization of study phases, lack of blinding of participants and/or assessors, and insufficient sampling. Low external validity was mainly related to incomplete information on the setting, lack of use of appropriate analysis or justification for the suitability of the analysis procedure used, and lack of replication across participants and/or behaviors. Results in terms of WM, spoken sentence comprehension, and reading are promising, but further studies with more rigorous methodology and stronger experimental control are needed to determine the beneficial effects of WM intervention. Conclusions: Results of the empirical studies suggest that WM can be improved with a computerized and adaptive WM training, and improvements can lead to transfer effects to spoken sentence comprehension and functional communication in some individuals with chronic post-stroke aphasia. The fact that improvements were not specific to certain syntactic structures (i.e., non-canonical complex sentences) in spoken sentence comprehension suggest that WM is not involved in the online, automatic processing of syntactic information (i.e., parsing and interpretation), but plays a more general role in the later stage of spoken sentence comprehension (i.e., post-interpretive comprehension). The individual differences in treatment outcomes call for future research to clarify how far these results are generalizable to the population level of IWA. Future studies are needed to identify a few mechanisms that may generalize to at least a subpopulation of IWA as well as to investigate baseline non-linguistic cognitive and language abilities that may play a role in transfer effects and the maintenance of such effects. These may require larger yet homogenous samples.},
  language  = {en}
}
@phdthesis{Bergholz2018,
  author    = {Bergholz, Kolja},
  title     = {Trait-based understanding of plant species distributions along environmental gradients},
  doi       = {10.25932/publishup-42634},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-426341},
  school      = {Universit{\"a}t Potsdam},
  pages     = {128},
  year      = {2018},
  abstract  = {For more than two centuries, plant ecologists have aimed to understand how environmental gradients and biotic interactions shape the distribution and co-occurrence of plant species. In recent years, functional trait-based approaches have been increasingly used to predict patterns of species co-occurrence and species distributions along environmental gradients (trait-environment relationships). Functional traits are measurable properties at the individual level that correlate well with important processes. Thus, they allow us to identify general patterns by synthesizing studies across specific taxonomic compositions, thereby fostering our understanding of the underlying processes of species assembly. However, the importance of specific processes have been shown to be highly dependent on the spatial scale under consideration. In particular, it remains uncertain which mechanisms drive species assembly and allow for plant species coexistence at smaller, more local spatial scales. Furthermore, there is still no consensus on how particular environmental gradients affect the trait composition of plant communities. For example, increasing drought because of climate change is predicted to be a main threat to plant diversity, although it remains unclear which traits of species respond to increasing aridity. Similarly, there is conflicting evidence of how soil fertilization affects the traits related to establishment ability (e.g., seed mass). In this cumulative dissertation, I present three empirical trait-based studies that investigate specific research questions in order to improve our understanding of species distributions along environmental gradients. In the first case study, I analyze how annual species assemble at the local scale and how environmental heterogeneity affects different facets of biodiversity—i.e. taxonomic, functional, and phylogenetic diversity—at different spatial scales. The study was conducted in a semi-arid environment at the transition zone between desert and Mediterranean ecosystems that features a sharp precipitation gradient (Israel). Different null model analyses revealed strong support for environmentally driven species assembly at the local scale, since species with similar traits tended to co-occur and shared high abundances within microsites (trait convergence). A phylogenetic approach, which assumes that closely related species are functionally more similar to each other than distantly related ones, partly supported these results. However, I observed that species abundances within microsites were, surprisingly, more evenly distributed across the phylogenetic tree than expected (phylogenetic overdispersion). Furthermore, I showed that environmental heterogeneity has a positive effect on diversity, which was higher on functional than on taxonomic diversity and increased with spatial scale. The results of this case study indicate that environmental heterogeneity may act as a stabilizing factor to maintain species diversity at local scales, since it influenced species distribution according to their traits and positively influenced diversity. All results were constant along the precipitation gradient. In the second case study (same study system as case study one), I explore the trait responses of two Mediterranean annuals (Geropogon hybridus and Crupina crupinastrum) along a precipitation gradient that is comparable to the maximum changes in precipitation predicted to occur by the end of this century (i.e., -30\%). The heterocarpic G. hybridus showed strong trends in seed traits, suggesting that dispersal ability increased with aridity. By contrast, the homocarpic C. crupinastrum showed only a decrease in plant height as aridity increased, while leaf traits of both species showed no consistent pattern along the precipitation gradient. Furthermore, variance decomposition of traits revealed that most of the trait variation observed in the study system was actually found within populations. I conclude that trait responses towards aridity are highly species-specific and that the amount of precipitation is not the most striking environmental factor at this particular scale. In the third case study, I assess how soil fertilization mediates—directly by increased nutrient addition and indirectly by increased competition—the effect of seed mass on establishment ability. For this experiment, I used 22 species differing in seed mass from dry grasslands in northeastern Germany and analyzed the interacting effects of seed mass with nutrient availability and competition on four key components of seedling establishment: seedling emergence, time of seedling emergence, seedling survival, and seedling growth. (Time of) seedling emergence was not affected by seed mass. However, I observed that the positive effect of seed mass on seedling survival is lowered under conditions of high nutrient availability, whereas the positive effect of seed mass on seedling growth was only reduced by competition. Based on these findings, I developed a conceptual model of how seed mass should change along a soil fertility gradient in order to reconcile conflicting findings from the literature. In this model, seed mass shows a U-shaped pattern along the soil fertility gradient as a result of changing nutrient availability and competition. Overall, the three case studies highlight the role of environmental factors on species distribution and co-occurrence. Moreover, the findings of this thesis indicate that spatial heterogeneity at local scales may act as a stabilizing factor that allows species with different traits to coexist. In the concluding discussion, I critically debate intraspecific trait variability in plant community ecology, the use of phylogenetic relationships and easily measured key functional traits as a proxy for species' niches. Finally, I offer my outlook for the future of functional plant community research.},
  language  = {en}
}
@phdthesis{Lee2018,
  author    = {Lee, Hui-Chun},
  title     = {Toward ultimate control of polymerization and catalytic property},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414973},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vii, iii, 150},
  year      = {2018},
  abstract  = {Reversible-deactivation radical polymerization (RDRP) is without any doubt one of the most prevalent and powerful strategies for polymer synthesis, by which well-defined living polymers with targeted molecular weight (MW), low molar dispersity (Ɖ) and diverse morphologies can be prepared in a controlled fashion. Atom transfer radical polymerization (ATRP) as one of the most extensive studied types of RDRP has been particularly emphasized due to the high accessibility to hybrid materials, multifunctional copolymers and diverse end group functionalities via commercially available precursors. However, due to catalyst-induced side reactions and chain-chain coupling termination in bulk environment, synthesis of high MW polymers with uniform chain length (low Ɖ) and highly-preserved chain-end fidelity is usually challenging. Besides, owing to the inherited radical nature, the control of microstructure, namely tacticity control, is another laborious task. Considering the applied catalysts, the utilization of large amounts of non-reusable transition metal ions which lead to cumbersome purification process, product contamination and complicated reaction procedures all delimit the scope ATRP techniques. Metal-organic frameworks (MOFs) are an emerging type of porous materials combing the properties of both organic polymers and inorganic crystals, characterized with well-defined crystalline framework, high specific surface area, tunable porous structure and versatile nanochannel functionalities. These promising properties of MOFs have thoroughly revolutionized academic research and applications in tremendous aspects, including gas processing, sensing, photoluminescence, catalysis and compartmentalized polymerization. Through functionalization, the microenvironment of MOF nanochannel can be precisely devised and tailored with specified functional groups for individual host-guest interactions. Furthermore, properties of high transition metal density, accessible catalytic sites and crystalline particles all indicate MOFs as prominent heterogeneous catalysts which open a new avenue towards unprecedented catalytic performance. Although beneficial properties in catalysis, high agglomeration and poor dispersibility restrain the potential catalytic capacity to certain degree. Due to thriving development of MOF sciences, fundamental polymer science is undergoing a significant transformation, and the advanced polymerization strategy can eventually refine the intrinsic drawbacks of MOF solids reversely. Therefore, in the present thesis, a combination of low-dimensional polymers with crystalline MOFs is demonstrated as a robust and comprehensive approach to gain the bilateral advantages from polymers (flexibility, dispersibility) and MOFs (stability, crystallinity). The utilization of MOFs for in-situ polymerizations and catalytic purposes can be realized to synthesize intriguing polymers in a facile and universal process to expand the applicability of conventional ATRP methodology. On the other hand, through the formation of MOF/polymer composites by surface functionalization, the MOF particles with environment-adjustable dispersibility and high catalytic property can be as-prepared. In the present thesis, an approach via combination of confined porous textures from MOFs and controlled radical polymerization is proposed to advance synthetic polymer chemistry. Zn2(bdc)2(dabco) (Znbdc) and the initiator-functionalized Zn MOFs, ZnBrbdc, are utilized as a reaction environment for in-situ polymerization of various size-dependent methacrylate monomers (i.e. methyl, ethyl, benzyl and isobornyl methacrylate) through (surface-initiated) activators regenerated by electron transfer (ARGET/SI-ARGET) ATRP, resulting in polymers with control over dispersity, end functionalities and tacticity with respect to distinct molecular size. While the functionalized MOFs are applied, due to the strengthened compartmentalization effect, the accommodated polymers with molecular weight up to 392,000 can be achieved. Moreover, a significant improvement in end-group fidelity and stereocontrol can be observed. The results highlight a combination of MOFs and ATRP is a promising and universal methodology to synthesize versatile well-defined polymers with high molecular weight, increment in isotactic trial and the preserved chain-end functionality. More than being a host only, MOFs can act as heterogeneous catalysts for metal-catalyzed polymerizations. A Cu(II)-based MOF, Cu2(bdc)2(dabco), is demonstrated as a heterogeneous, universal catalyst for both thermal or visible light-triggered ARGET ATRP with expanded monomer range. The accessible catalytic metal sites enable the Cu(II) MOF to polymerize various monomers, including benzyl methacrylate (BzMA), styrene, methyl methacrylate (MMA), 2-(dimethylamino)ethyl methacrylate (DMAEMA) in the fashion of ARGET ATRP. Furthermore, due to the robust frameworks, surpassing the conventional homogeneous catalyst, the Cu(II) MOF can tolerate strongly coordinating monomers and polymerize challenging monomers (i.e. 4-vinyl pyridine, 2-vinyl pyridine and isoprene), in a well-controlled fashion. Therefore, a synthetic procedure can be significantly simplified, and catalyst-resulted chelation can be avoided as well. Like other heterogeneous catalysts, the Cu(II) MOF catalytic complexes can be easily collected by centrifugation and recycled for an arbitrary amount of times. The Cu(II) MOF, composed of photostimulable metal sites, is further used to catalyze controlled photopolymerization under visible light and requires no external photoinitiator, dye sensitizer or ligand. A simple light trigger allows the photoreduction of Cu(II) to the active Cu(I) state, enabling controlled polymerization in the form of ARGET ATRP. More than polymerization application, the synergic effect between MOF frameworks and incorporated nucleophilic monomers/molecules is also observed, where the formation of associating complexes is able to adjust the photochemical and electrochemical properties of the Cu(II) MOF, altering the band gap and light harvesting behavior. Owing to the tunable photoabsorption property resulting from the coordinating guests, photoinduced Reversible-deactivation radical polymerization (PRDRP) can be achieved to further simplify and fasten the polymerization. More than the adjustable photoabsorption ability, the synergistic strategy via a combination of controlled/living polymerization technique and crystalline MOFs can be again evidenced as demonstrated in the MOF-based heterogeneous catalysts with enhanced dispersibility in solution. Through introducing hollow pollen pivots with surface immobilized environment-responsive polymer, PDMAEMA, highly dispersed MOF nanocrystals can be prepared after associating on polymer brushes via the intrinsic amine functionality in each DMAEMA monomer. Intriguingly, the pollen-PDMAEMA composite can serve as a "smart" anchor to trap nanoMOF particles with improved dispersibility, and thus to significantly enhance liquid-phase photocatalytic performance. Furthermore, the catalytic activity can be switched on and off via stimulable coil-to-globule transition of the PDMAEMA chains exposing or burying MOF catalytic sites, respectively.},
  language  = {en}
}
@phdthesis{Weiss2018,
  author    = {Weiß, Katharina},
  title     = {Three Essays on EFRAG},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-415355},
  school      = {Universit{\"a}t Potsdam},
  pages     = {II, 180},
  year      = {2018},
  abstract  = {This cumulative doctoral thesis consists of three papers that deal with the role of one specific European accounting player in the international accounting standard-setting, namely the European Financial Reporting Advisory Group (EFRAG). The first paper examines whether and how EFRAG generally fulfills its role in articulating Europe's interests toward the International Accounting Standards Board (IASB). The qualitative data from the conducted interviews reveal that EFRAG influences the IASB's decision making at a very early stage, long before other constituents are officially asked to comment on the IASB's proposals. The second paper uses quantitative data and investigates the formal participation behavior of European constituents that seek to determine EFRAG's voice. More precisely, this paper analyzes the nature of the constituents' participation in EFRAG's due process in terms of representation (constituent groups and geographical distribution) and the drivers of their participation behavior. EFRAG's official decision making process is dominated by some specific constituent groups (such as preparers and the accounting profession) and by constituents from some specific countries (e.g. those with effective enforcement regimes). The third paper investigates in a first step who of the European constituents choose which lobbying channel (participation only at IASB, only at EFRAG, or at both institutions) and unveils in a second step possible reasons for their lobbying choices. The paper comprises quantitative and qualitative data. It reveals that English skills, time issues, the size of the constituent, and the country of origin are factors that can explain why the majority participates only in the IASB's due process.},
  language  = {en}
}
@phdthesis{Nizardo2018,
  author    = {Nizardo, Noverra Mardhatillah},
  title     = {Thermoresponsive block copolymers with UCST-behavior aimed at biomedical environments},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-412217},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xiii, 134},
  year      = {2018},
  abstract  = {Thermoresponsive block copolymers of presumably highly biocompatible character exhibiting upper critical solution temperature (UCST) type phase behavior were developed. In particular, these polymers were designed to exhibit UCST-type cloud points (Tcp) in physiological saline solution (9 g/L) within the physiologically interesting window of 30-50°C. Further, their use as carrier for controlled release purposes was explored. Polyzwitterion-based block copolymers were synthesized by atom transfer radical polymerization (ATRP) via a macroinitiator approach with varied molar masses and co-monomer contents. These block copolymers can self-assemble in the amphiphilic state to form micelles, when the thermoresponsive block experiences a coil-to-globule transition upon cooling. Poly(ethylene glycol) methyl ether (mPEG) was used as the permanently hydrophilic block to stabilize the colloids formed, and polyzwitterions as the thermoresponsive block to promote the temperature-triggered assembly-disassembly of the micellear aggregates at low temperature. Three zwitterionic monomers were used for this studies, namely 3-((2-(methacryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate (SPE), 4-((2-(methacryloyl- oxy)ethyl)dimethylammonio)butane-1-sulfonate (SBE), and 3-((2-(methacryloyloxy)ethyl)- dimethylammonio)propane-1-sulfate) (ZPE). Their (co)polymers were characterized with respect to their molecular structure by proton nuclear magnetic resonance (1H-NMR) and gel permeation chromatography (GPC). Their phase behaviors in pure water as well as in physiological saline were studied by turbidimetry and dynamic light scattering (DLS). These (co)polymers are thermoresponsive with UCST-type phase behavior in aqueous solution. Their phase transition temperatures depend strongly on the molar masses and the incorporation of co-monomers: phase transition temperatures increased with increasing molar masses and content of poorly water-soluble co-monomer. In addition, the presence of salt influenced the phase transition dramatically. The phase transition temperature decreased with increasing salt content in the solution. While the PSPE homopolymers show a phase transition only in pure water, the PZPE homopolymers are able to exhibit a phase transition only in high salinity, as in physiological saline. Although both polyzwitterions have similar chemical structures that differ only in the anionic group (sulfonate group in SPE and sulfate group in ZPE), the water solubility is very different. Therefore, the phase transition temperatures of targeted block copolymers were modulated by using statistical copolymer of SPE and ZPE as thermoresponsive block, and varying the ratio of SPE to ZPE. Indeed, the statistical copolymers of P(SPE-co-ZPE) show phase transitions both in pure water as well as in physiological saline. Surprisingly, it was found that mPEG-b-PSBE block copolymer can display "schizophrenic" behavior in pure water, with the UCST-type cloud point occurring at lower temperature than the LCST-type one. The block copolymer, which satisfied best the boundary conditions, is block copolymer mPEG114-b-P(SPE43-co-ZPE39) with a cloud point of 45°C in physiological saline. Therefore, it was chosen for solubilization studies of several solvatochromic dyes as models of active agents, using the thermoresponsive block copolymer as "smart" carrier. The uptake and release of the dyes were explored by UV-Vis and fluorescence spectroscopy, following the shift of the wavelength of the absorbance or emission maxima at low and high temperature. These are representative for the loaded and released state, respectively. However, no UCST-transition triggered uptake and release of these dyes could be observed. Possibly, the poor affinity of the polybetaines to the dyes in aqueous environtments may be related to the widely reported antifouling properties of zwitterionic polymers.},
  language  = {en}
}
@phdthesis{Garcia2018,
  author    = {Garcia, Rowena},
  title     = {Thematic role assignment and word order preferences in the child language acquisition of Tagalog},
  address   = {Potsdam},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421742},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvii, 201},
  year      = {2018},
  abstract  = {A critical task in daily communications is identifying who did what to whom in an utterance, or assigning the thematic roles agent and patient in a sentence. This dissertation is concerned with Tagalog-speaking children's use of word order and morphosyntactic markers for thematic role assignment. It aims to explain children's difficulties in interpreting sentences with a non-canonical order of arguments (i.e., patient-before-agent) by testing the predictions of the following accounts: the frequency account (Demuth, 1989), the Competition model (MacWhinney \& Bates, 1989), and the incremental processing account (Trueswell \& Gleitman, 2004). Moreover, the experiments in this dissertation test the influence of a word order strategy in a language like Tagalog, where the thematic roles are always unambiguous in a sentence, due to its verb-initial order and its voice-marking system. In Tagalog's voice-marking system, the inflection on the verb indicates the thematic role of the noun marked by 'ang.' First, the possible basis for a word order strategy in Tagalog was established using a sentence completion experiment given to adults and 5- and 7-year-old children (Chapter 2) and a child-directed speech corpus analysis (Chapter 3). In general, adults and children showed an agent-before-patient preference, although adults' preference was also affected by sentence voice. Children's comprehension was then examined through a self-paced listening and picture verification task (Chapter 3) and an eye-tracking and picture selection task (Chapter 4), where word order (agent-initial or patient-initial) and voice (agent voice or patient voice) were manipulated. Offline (i.e., accuracy) and online (i.e., listening times, looks to the target) measures revealed that 5- and 7-year-old Tagalog-speaking children had a bias to interpret the first noun as the agent. Additionally, the use of word order and morphosyntactic markers was found to be modulated by voice. In the agent voice, children relied more on a word order strategy; while in the patient voice, they relied on the morphosyntactic markers. These results are only partially explained by the accounts being tested in this dissertation. Instead, the findings support computational accounts of incremental word prediction and learning such as Chang, Dell, \& Bock's (2006) model.},
  language  = {en}
}
@phdthesis{Paganini2018,
  author    = {Paganini, Claudio Francesco},
  title     = {The role of trapping in black hole spacetimes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414686},
  school      = {Universit{\"a}t Potsdam},
  pages     = {v, 138},
  year      = {2018},
  abstract  = {In the here presented work we discuss a series of results that are all in one way or another connected to the phenomenon of trapping in black hole spacetimes. First we present a comprehensive review of the Kerr-Newman-Taub-NUT-de-Sitter family of black hole spacetimes and their most important properties. From there we go into a detailed analysis of the bahaviour of null geodesics in the exterior region of a sub-extremal Kerr spacetime. We show that most well known fundamental properties of null geodesics can be represented in one plot. In particular, one can see immediately that the ergoregion and trapping are separated in phase space. We then consider the sets of future/past trapped null geodesics in the exterior region of a sub-extremal Kerr-Newman-Taub-NUT spacetime. We show that from the point of view of any timelike observer outside of such a black hole, trapping can be understood as two smooth sets of spacelike directions on the celestial sphere of the observer. Therefore the topological structure of the trapped set on the celestial sphere of any observer is identical to that in Schwarzschild. We discuss how this is relevant to the black hole stability problem. In a further development of these observations we introduce the notion of what it means for the shadow of two observers to be degenerate. We show that, away from the axis of symmetry, no continuous degeneration exists between the shadows of observers at any point in the exterior region of any Kerr-Newman black hole spacetime of unit mass. Therefore, except possibly for discrete changes, an observer can, by measuring the black holes shadow, determine the angular momentum and the charge of the black hole under observation, as well as the observer's radial position and angle of elevation above the equatorial plane. Furthermore, his/her relative velocity compared to a standard observer can also be measured. On the other hand, the black hole shadow does not allow for a full parameter resolution in the case of a Kerr-Newman-Taub-NUT black hole, as a continuous degeneration relating specific angular momentum, electric charge, NUT charge and elevation angle exists in this case. We then use the celestial sphere to show that trapping is a generic feature of any black hole spacetime. In the last chapter we then prove a generalization of the mode stability result of Whiting (1989) for the Teukolsky equation for the case of real frequencies. The main result of the last chapter states that a separated solution of the Teukolsky equation governing massless test fields on the Kerr spacetime, which is purely outgoing at infinity, and purely ingoing at the horizon, must vanish. This has the consequence, that for real frequencies, there are linearly independent fundamental solutions of the radial Teukolsky equation which are purely ingoing at the horizon, and purely outgoing at infinity, respectively. This fact yields a representation formula for solutions of the inhomogenous Teukolsky equation, and was recently used by Shlapentokh-Rothman (2015) for the scalar wave equation.},
  language  = {en}
}
@phdthesis{Jovanovic2018,
  author    = {Jovanovic, Nenad},
  title     = {The comprehension of the passive voice by different populations and the effects of structural priming on this process},
  doi       = {10.25932/publishup-47590},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-475900},
  school      = {Universit{\"a}t Potsdam},
  pages     = {viii, 164},
  year      = {2018},
  abstract  = {This thesis investigates the comprehension of the passive voice in three distinct populations. First, the comprehension of passives by adult German speakers was studied, followed by an examination of how German-speaking children comprehend the structure. Finally, bilingual Mandarin-English speakers were tested on their comprehension of the passive voice in English, which is their L2. An integral part of testing the comprehension in all three populations is the use of structural priming. In each of the three distinct parts of the research, structural priming was used for a specific reason. In the study involving adult German speakers, productive and receptive structural priming was directly compared. The goal was to see the effect the two priming modalities have on language comprehension. In the study on German-acquiring children, structural priming was an important tool in answering the question regarding the delayed acquisition of the passive voice. Finally, in the study on the bilingual population, cross-linguistic priming was used to investigate the importance of word order in the priming effect, since Mandarin and English have different word orders in passive voice sentences.},
  language  = {en}
}
@phdthesis{Biewener2018,
  author    = {Biewener, Ann-Kathrin},
  title     = {S{\"a}kularisierung im Heiligen Land?},
  doi       = {10.25932/publishup-42491},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-424916},
  school      = {Universit{\"a}t Potsdam},
  pages     = {241},
  year      = {2018},
  abstract  = {Von einer S{\"a}kularisierung in einem Land wie Israel zu sprechen, wo die Religion offensichtlich einen wichtigen Teil des {\"o}ffentlichen Lebens darstellt, scheint widerspr{\"u}chlich zu sein. Doch Israel befindet sich bedingt durch Globalisierung, Pluralisierung und Modernisierung an einem Scheideweg. Teile der israelischen Gesellschaft s{\"a}kularisieren sich bereits. Die religi{\"o}se orthodoxe Vorherrschaft scheint zu br{\"o}ckeln. Kann jedoch deswegen von einem Mentalit{\"a}tswandel oder einer S{\"a}kularisierung des Staates gesprochen werden? Kann ein S{\"a}kularisierungsprozess in Israel erfolgreich sein? Wie muss ein s{\"a}kularer Staat beschaffen sein, um den unterschiedlichen religi{\"o}sen Denominationen die gleichen M{\"o}glichkeiten zu bieten? Welche Rolle spielen dabei die j{\"u}dische Diaspora, Einwanderungen und gesellschaftliche Minderheiten? Ziel der vorliegenden Arbeit ist es diese Fragen zu er{\"o}rtern. Auch wenn die enge Verkn{\"u}pfung von Nation und Religion im Judentum eine S{\"a}kularisierung scheinbar unm{\"o}glich macht, so erlaubt unter Bezugnahme der Konzepte von S{\"a}kularismus und Nationalismus im Kontext der historischen Entwicklungen des Judentums eine differenziertere Betrachtung dieser Verkn{\"u}pfung. Durch die Nutzung von unterschiedlichen qualitativen Methoden, wie der hermeneutischen Methode zur Betrachtung der verschiedenen theoretischen Begriffe und der Analyse des Verh{\"a}ltnisses von Nation und Religion im Judentum; der Nutzung von Zeitungsartikel zur Aufarbeitung der aktuellen Debatten in der israelischen Gesellschaft; der Auswertung von Statistiken; sowie der Durchf{\"u}hrung von Experteninterviews erlauben einen vielseitigen Zugang zum Forschungsgegenstand. Letztendlich soll aufgezeigt werden, dass sich Israel zwar zunehmend s{\"a}kularisiert, aber vor verschiedenen Herausforderungen, wie dem gesellschaftlichen Pluralismus, der instabilen Sicherheitslage, sowie einem zunehmenden religi{\"o}sen Nationalismus steht.},
  language  = {de}
}
@phdthesis{Tan2018,
  author    = {Tan, Li},
  title     = {Synthesis, assembly and thermo-responsivity of polymer-functionalized magnetic cobalt nanoparticles},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418153},
  school      = {Universit{\"a}t Potsdam},
  pages     = {X, 111},
  year      = {2018},
  abstract  = {This thesis mainly covers the synthesis, surface modification, magnetic-field-induced assembly and thermo-responsive functionalization of superparamagnetic Co NPs initially stabilized by hydrophobic small molecules oleic acid (OA) and trioctylphosphine oxide (TOPO), as well as the synthesis of both superparamagnetic and ferromagnetic Co NPs by using end-functionalized-polystyrene as stabilizer. Co NPs, due to their excellent magnetic and catalytic properties, have great potential application in various fields, such as ferrofluids, catalysis, and magnetic resonance imaging (MRI). Superparamagnetic Co NPs are especially interesting, since they exhibit zero coercivity. They get magnetized in an external magnetic field and reach their saturation magnetization rapidly, but no magnetic moment remains after removal of the applied magnetic field. Therefore, they do not agglomerate in the body when they are used in biomedical applications. Normally, decomposition of metallic precursors at high temperature is one of the most important methods in preparation of monodisperse magnetic NPs, providing tunability in size and shape. Hydrophobic ligands like OA, TOPO and oleylamine are often used to both control the growth of NPs and protect them from agglomeration. The as-prepared magnetic NPs can be used in biological applications as long as they are transferred into water. Moreover, their supercrystal assemblies have the potential for high density data storage and electronic devices. In addition to small molecules, polymers can also be used as surfactants for the synthesis of ferromagnetic and superparamagnetic NPs by changing the reaction conditions. Therefore, chapter 2 gives an overview on the basic concept of synthesis, surface modification and self-assembly of magnetic nanoparticles. Various examples were used to illustrate the recent work. The hydrophobic Co NPs synthesized with small molecules as surfactants limit their biological applications, which require a hydrophilic or aqueous environment. Surface modification (e.g., ligand exchange) is a general idea for either phase transition or surface-functionalization. Therefore, in chapter 3, a ligand exchange process was conducted to functionalize the surface of Co NPs. PNIPAM is one of the most popular smart polymers and its lower critical solution temperature (LCST) is around 32 °C, with a reversible change in the conformation structure between hydrophobic and hydrophilic. The novel nanocomposites of superparamagnetic Co NPs and thermo-responsive PNIPAM are of great interest. Thus, well-defined superparamagnetic Co NPs were firstly synthesized through the thermolysis of cobalt carbonyl by using OA and TOPO as surfactants. A functional ATRP initiator, containing an amine (as anchoring group) and a 2-bromopropionate group (SI-ATRP initiator), was used to replace the original ligands. This process is rapid and facial for efficient surface functionalization and afterwards the Co NPs can be dispersed into polar solvent DMF without aggregation. FT-IR spectroscopy showed that the TOPO was completely replaced, but a small amount of OA remained on the surface. A TGA measurement allowed the calculation of the grafting density of the initiator as around 3.2 initiator/nm2. Then, the surface-initiated ATRP was conducted for the polymerization of NIPAM on the surface of Co NPs and rendered the nanocomposites water-dispersible. A temperature-dependent dynamic light scattering study showed the aggregation behavior of PNIPAM-coated Co NPs upon heating and this process was proven to be reversible. The combination of superparamagnetic and thermo-responsive properties in these hybrid nanoparticles is promising for future applications e.g. in biomedicine. In chapter 4, the magnetic-field-induced assembly of superparamagnetic cobalt nanoparticles both on solid substrates and at liquid-air interface was investigated. OA- and TOPO-coated Co NPs were synthesized via the thermolysis of cobalt carbonyl and dispersed into either hexane or toluene. The Co NP dispersion was dropped onto substrates (e.g., TEM grid, silicon wafer) and at liquid-air (water-air or ethylene glycol-air) interface. Due to the attractive dipolar interaction, 1-D chains formed in the presence of an external magnetic field. It is known that the concentration and the strength of the magnetic field can affect the assembly behavior of superparamagnetic Co NPs. Therefore, the influence of these two parameters on the morphology of the assemblies was studied. The formed 1-D chains were shorter and flexible at either lower concentration of the Co NP dispersion or lower strength of the external magnetic field due to thermal fluctuation. However, by increasing either the concentration of the NP dispersion or the strength of the applied magnetic field, these chains became longer, thicker and straighter. The reason could be that a high concentration led to a high fraction of short dipolar chains, and their interaction resulted in longer and thicker chains under applied magnetic field. On the other hand, when the magnetic field increased, the induced moments of the magnetic nanoparticles became larger, which dominated over the thermal fluctuation. Thus, the formed short chains connected to each other and grew in length. Thicker chains were also observed through chain-chain interaction. Furthermore, the induced moments of the NPs tended to direct into one direction with increased magnetic field, thus the chains were straighter. In comparison between the assembly on substrates, at water-air interface and at ethylene glycol-air interface, the assembly of Co NPs in hexane dispersion at ethylene glycol-air interface showed the most regular and homogeneous chain structures due to the better spreading of the dispersion on ethylene glycol subphase than on water subphase and substrates. The magnetic-field-induced assembly of superparamagnetic nanoparticles could provide a powerful approach for applications in data storage and electronic devices. Chapter 5 presented the synthesis of superparamagnetic and ferromagnetic cobalt nanoparticles through a dual-stage thermolysis of cobalt carbonyl (Co2(CO)8) by using polystyrene as surfactant. The amine end-functionalized polystyrene surfactants with different molecular weight were prepared via atom transfer radical polymerization technique. The molecular weight determination of polystyrene was conducted by gel permeation chromatography (GPC) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectrometry techniques. The results showed that, when the molecular weight distribution is low (Mw/Mn < 1.2), the measurement by GPC and MALDI-ToF MS provided nearly similar results. For example, the molecular weight of 10600 Da was obtained by MALDI-ToF MS, while GPC gave 10500 g/mol (Mw/Mn = 1.17). However, if the polymer is poly distributed, MALDI-ToF MS cannot provide an accurate value. This was exemplified for a polymer with a molecular weight of 3130 Da measured by MALDI-TOF MS, while GPC showed 2300 g/mol (Mw/Mn = 1.38). The size, size distribution and magnetic properties of the hybrid particles were different by changing either the molecular weight or concentration of the polymer surfactants. The analysis from TEM characterization showed that the size of cobalt nanoparticles stabilized with polystyrene of lower molecular weight (Mn = 2300 g/mol) varied from 12-22 nm, while the size with middle (Mn = 4500 g/mol) and higher molecular weight (Mn = 10500 g/mol) of polystyrene-coated cobalt nanoparticles showed little change. Magnetic measurements exhibited that the small cobalt particles (12 nm) were superparamagnetic, while larger particles (21 nm) were ferromagnetic and assembled into 1-D chains. The grafting density calculated from thermogravimetric analysis showed that a higher grafting density of polystyrene was obtained with lower molecular weight (Mn = 2300 g/mol) than those with higher molecular weight (Mn = 10500 g/mol). Due to the larger steric hindrance, polystyrene with higher molecular weight cannot form a dense shell on the surface of the nanoparticles, which resulted in a lower grafting density. Wide angle X-ray scattering measurements revealed the epsilon cobalt crystalline phases of both superparamagnetic Co NPs coated with polystyrene (Mn = 2300 g/mol) and ferromagnetic Co NPs coated with polystyrene (Mn = 10500 g/mol). Furthermore, a stability study showed that PS-Co NPs prepared with higher polymer concentration and polymer molecular weight exhibited a better stability.},
  language  = {en}
}
@phdthesis{Karras2018,
  author    = {Karras, Manfred},
  title     = {Synthesis of enantiomerically pure helical aromatics such as NHC ligands and their use in asymmetric catalysis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421497},
  school      = {Universit{\"a}t Potsdam},
  pages     = {121},
  year      = {2018},
  abstract  = {Diese Arbeit besch{\"a}ftigt sich mit der enantiomerenreinen Synthese helikaler, aromatischer Verbindungen. Verschiedene Verbindungen dieses Typs wurden erfolgreich hergestellt und charakterisiert. Desweiteren wurden einige der neuen Verbindungen in {\"U}bergangsmetallkomplexe eingebaut und diese dann als Katalysatoren f{\"u}r Metathese und Kreuzkupplungen getestet. Einer der getesteten Katalysatoren zeigte vielversprechende Ergebnisse in der asymmetrischen Olefinmetathese. Die Struktur des neuen Katalysators wurde untersucht. Anhand der Struktur des neuen Katalysators wurden R{\"u}ckschl{\"u}sse auf einen m{\"o}glichen Mechanismus gezogen.},
  language  = {en}
}
@phdthesis{Dai2018,
  author    = {Dai, Xiaolin},
  title     = {Synthesis of artificial building blocks for sortase-mediated ligation and their enzymatic linkage},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420060},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XIV, 125},
  year      = {2018},
  abstract  = {Das Enzym Sortase A katalysiert die Bildung einer Peptidbindung zwischen der Erkennungssequenz LPXTG und einem Oligoglycin. W{\"a}hrend vielf{\"a}ltige Ligationen zwischen Proteinen und verschiedenen Biomolek{\"u}len, Proteinen und kleinen synthetischen Molek{\"u}len, sowie Proteinen und Oberfl{\"a}chen durchgef{\"u}hrt wurden, besteht das Ziel dieser Arbeit darin, die Sortase-katalysierte Verlinkung von synthetischen Bausteinen zu untersuchen. Dies k{\"o}nnte den Weg bereiten f{\"u}r die Anwendung von Sortase A f{\"u}r chemische Aufgabenstellungen und eventuell sogar in den Materialwissenschaften. F{\"u}r diese grunds{\"a}tzliche Untersuchung wurden die verwendeten Bausteine zun{\"a}chst so einfach wie m{\"o}glich gehalten und leicht zug{\"a}ngliche SiO2 Nanopartikel und kommerziell erh{\"a}ltliche Polymerbl{\"o}cke ausgew{\"a}hlt. Die Bausteine wurden als erstes mit den Peptidsequenzen f{\"u}r Sortase-vermittelte Ligationen funktionalisiert. SiO2 Nanopartikel wurden mit Durchmessern von 60 und 200 nm hergestellt und mit C=C Doppelbindungen oberfl{\"a}chenmodifiziert. Dann wurden Peptide mit einem terminalen Cystein kovalent durch eine Thiol-en Reaktion angebunden. An die 60 nm NP wurden Peptide mit einem Pentaglycin und an die 200 nm Partikel Peptide mit LPETG Sequenz gebunden. Auf die gleiche Art und Weise wurden Peptide mit terminalem Cystein an die Polymere Polyethylenglykol (PEG) und Poly(N Isopropylacrylamid) (PNIPAM), die beide {\"u}ber C=C Endgruppen verf{\"u}gen, gebunden und G5-PEG und PNIPAM-LPETG Konjugate erhalten. Mit den vier Bausteinen wurden nun durch Sortase-vermittelte Ligation NP-Polymer Hybride, NP-NP und Polymer-Polymer Strukturen hergestellt und die Produkte u. a. durch Transmissionselektronen-mikroskopie, MALDI-ToF Massenspektrometrie sowie Dynamische Lichtstreuung charakterisiert. Die Verlinkung dieser synthetischen Bausteine konnte eindeutig gezeigt werden. Das Verwenden von kommerziell erh{\"a}ltlichen Polymeren hat jedoch zu einem Gemisch der Polymer-Peptid Konjugate mit unmodifiziertem Polymer gef{\"u}hrt, welches nicht gereinigt werden konnte. Deswegen wurden anschließend Synthesestrategien f{\"u}r reine Peptid-Polymer und Polymer-Peptid Konjugate als Bausteine f{\"u}r Sortase-vermittelte Ligationen entwickelt. Diese basieren auf der RAFT Polymerisation mit CTAs, die entweder an N- oder C-Terminus eines Peptids gebunden sind. GG-PNIPAM wurde durch das Anbinden eines geeigneten RAFT CTAs an Fmoc-GG in einer Veresterungsreaktion, Polymerisation von NIPAM und Abspalten der Fmoc Schutzgruppe synthetisiert. Weiterhin wurden mehrere Peptide durch Festphasen-Peptidsynthese erhalten. Die Anbindung eines RAFT CTAs (oder eines Polymerisationsinitiators) an den N-Terminus eines Peptids kann automatisiert als letzter Schritt in einem Peptid-Synthetisierer erfolgen. Die Synthese eines solchen Konjugats konnte in dem Zeithorizont dieser Arbeit noch nicht erreicht werden. Jedoch existieren mehrere vielversprechende Strategien, um diesen Ansatz mit verschiedenen Kopplungsreagenzien zur Anbindung des CTAs fortzusetzen. Solche Polymer Bausteine k{\"o}nnen in Zukunft f{\"u}r die Synthese von Protein-Polymer Konjugaten durch Sortase-Katalyse verwendet werden. Außerdem kann der Ansatz auch f{\"u}r die Synthese von Block-Copolymeren aus Polymerbl{\"o}cken mit Peptidmotiven an beiden Enden ausgebaut werden. Auch wenn bei der grunds{\"a}tzlichen Untersuchung im Rahmen dieser Arbeit Hybridstrukturen hergestellt wurden, die auch durch traditionelle chemische Synthesen erhalten werden k{\"o}nnten, wird ein Bausatz solcher Bausteine in Zukunft die Synthese neuer Materialien erm{\"o}glichen und kann auch den Weg f{\"u}r die Anwendung von Enzymen in den Materialwissenschaften ebnen. In Erg{\"a}nzung zu Nanopartikeln und Block-Copolymeren k{\"o}nnen dann auch Hybridmaterialien unter Einbezug von Protein-basierten Bausteinen hergestellt werden. Daher k{\"o}nnten Sortase Enzyme zu einem Werkzeug werden, welches etablierte chemische Verlinkungstechniken erg{\"a}nzt und mit den hoch spezifischen Peptidmotiven {\"u}ber funktionale Einheiten verf{\"u}gt, die orthogonal zu allen chemischen Gruppen sind.},
  language  = {en}
}
@phdthesis{Quade2018,
  author    = {Quade, Markus},
  title     = {Symbolic regression for identification, prediction, and control of dynamical systems},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419790},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xiii, 134},
  year      = {2018},
  abstract  = {In the present work, we use symbolic regression for automated modeling of dynamical systems. Symbolic regression is a powerful and general method suitable for data-driven identification of mathematical expressions. In particular, the structure and parameters of those expressions are identified simultaneously. We consider two main variants of symbolic regression: sparse regression-based and genetic programming-based symbolic regression. Both are applied to identification, prediction and control of dynamical systems. We introduce a new methodology for the data-driven identification of nonlinear dynamics for systems undergoing abrupt changes. Building on a sparse regression algorithm derived earlier, the model after the change is defined as a minimum update with respect to a reference model of the system identified prior to the change. The technique is successfully exemplified on the chaotic Lorenz system and the van der Pol oscillator. Issues such as computational complexity, robustness against noise and requirements with respect to data volume are investigated. We show how symbolic regression can be used for time series prediction. Again, issues such as robustness against noise and convergence rate are investigated us- ing the harmonic oscillator as a toy problem. In combination with embedding, we demonstrate the prediction of a propagating front in coupled FitzHugh-Nagumo oscillators. Additionally, we show how we can enhance numerical weather predictions to commercially forecast power production of green energy power plants. We employ symbolic regression for synchronization control in coupled van der Pol oscillators. Different coupling topologies are investigated. We address issues such as plausibility and stability of the control laws found. The toolkit has been made open source and is used in turbulence control applications. Genetic programming based symbolic regression is very versatile and can be adapted to many optimization problems. The heuristic-based algorithm allows for cost efficient optimization of complex tasks. We emphasize the ability of symbolic regression to yield white-box models. In contrast to black-box models, such models are accessible and interpretable which allows the usage of established tool chains.},
  language  = {en}
}
@phdthesis{ChaleawlertUmpon2018,
  author    = {Chaleawlert-Umpon, Saowaluk},
  title     = {Sustainable electrode materials based on lignin},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-411793},
  school      = {Universit{\"a}t Potsdam},
  pages     = {114},
  year      = {2018},
  abstract  = {The utilization of lignin as renewable electrode material for electrochemical energy storage is a sustainable approach for future batteries and supercapacitors. The composite electrode was fabricated from Kraft lignin and conductive carbon and the charge storage contribution was determined in terms of electrical double layer (EDL) and redox reactions. The important factors at play for achieving high faradaic charge storage capacity contribute to high surface area, accessibility of redox sites in lignin and their interaction with conductive additives. A thinner layer of lignin covering the high surface area of carbon facilitates the electron transfer process with a shorter pathway from the active sites of nonconductive lignin to the current collector leading to the improvement of faradaic charge storage capacity. Composite electrodes from lignin and carbon would be even more sustainable if the fluorinated binder can be omitted. A new route to fabricate a binder-free composite electrode from Kraft lignin and high surface area carbon has been proposed by crosslinking lignin with glyoxal. A high molecular weight of lignin is obtained to enhance both electroactivity and binder capability in composite electrodes. The order of the processing step of crosslinking lignin on the composite electrode plays a crucial role in achieving a stable electrode and high charge storage capacity. The crosslinked lignin based electrodes are promising since they allow for more stable, sustainable, halogen-free and environmentally benign devices for energy storage applications. Furthermore, improvement of the amount of redox active groups (quinone groups) in lignin is useful to enhance the capacity in lithium battery applications. Direct oxidative demethylation by cerium ammonium nitrate has been carried out under mild conditions. This proves that an increase of quinone groups is able to enhance the performance of lithium battery. Thus, lignin is a promising material and could be a good candidate for application in sustainable energy storage devices.},
  language  = {en}
}
@phdthesis{Sixtus2018,
  author    = {Sixtus, Elena},
  title     = {Subtle fingers - tangible numbers: The influence of finger counting experience on mental number representations},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420115},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vi, 138},
  year      = {2018},
  abstract  = {Numbers are omnipresent in daily life. They vary in display format and in their meaning so that it does not seem self-evident that our brains process them more or less easily and flexibly. The present thesis addresses mental number representations in general, and specifically the impact of finger counting on mental number representations. Finger postures that result from finger counting experience are one of many ways to convey numerical information. They are, however, probably the one where the numerical content becomes most tangible. By investigating the role of fingers in adults' mental number representations the four presented studies also tested the Embodied Cognition hypothesis which predicts that bodily experience (e.g., finger counting) during concept acquisition (e.g., number concepts) stays an immanent part of these concepts. The studies focussed on different aspects of finger counting experience. First, consistency and further details of spontaneously used finger configurations were investigated when participants repeatedly produced finger postures according to specific numbers (Study 1). Furthermore, finger counting postures (Study 2), different finger configurations (Study 2 and 4), finger movements (Study 3), and tactile finger perception (Study 4) were investigated regarding their capability to affect number processing. Results indicated that active production of finger counting postures and single finger movements as well as passive perception of tactile stimulation of specific fingers co-activated associated number knowledge and facilitated responses towards corresponding magnitudes and number symbols. Overall, finger counting experience was reflected in specific effects in mental number processing of adult participants. This indicates that finger counting experience is an immanent part of mental number representations. Findings are discussed in the light of a novel model. The MASC (Model of Analogue and Symbolic Codes) combines and extends two established models of number and magnitude processing. Especially a symbolic motor code is introduced as an essential part of the model. It comprises canonical finger postures (i.e., postures that are habitually used to represent numbers) and finger-number associations. The present findings indicate that finger counting functions both as a sensorimotor magnitude and as a symbolic representational format and that it thereby directly mediates between physical and symbolic size. The implications are relevant both for basic research regarding mental number representations and for pedagogic practices regarding the effectiveness of finger counting as a means to acquire a fundamental grasp of numbers.},
  language  = {en}
}
@phdthesis{Ramos2018,
  author    = {Ramos, Catalina},
  title     = {Structure and petrophysical properties of the Southern Chile subduction zone along 38.25°S from seismic data},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-409183},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvi, 111},
  year      = {2018},
  abstract  = {Active and passive source data from two seismic experiments within the interdisciplinary project TIPTEQ (from The Incoming Plate to mega Thrust EarthQuake processes) were used to image and identify the structural and petrophysical properties (such as P- and S-velocities, Poisson's ratios, pore pressure, density and amount of fluids) within the Chilean seismogenic coupling zone at 38.25°S, where in 1960 the largest earthquake ever recorded (Mw 9.5) occurred. Two S-wave velocity models calculated using traveltime and noise tomography techniques were merged with an existing velocity model to obtain a 2D S-wave velocity model, which gathered the advantages of each individual model. In a following step, P- and S-reflectivity images of the subduction zone were obtained using different pre stack and post-stack depth migration techniques. Among them, the recent prestack line-drawing depth migration scheme yielded revealing results. Next, synthetic seismograms modelled using the reflectivity method allowed, through their input 1D synthetic P- and S-velocities, to infer the composition and rocks within the subduction zone. Finally, an image of the subduction zone is given, jointly interpreting the results from this work with results from other studies. The Chilean seismogenic coupling zone at 38.25°S shows a continental crust with highly reflective horizontal, as well as (steep) dipping events. Among them, the Lanalhue Fault Zone (LFZ), which is interpreted to be east-dipping, is imaged to very shallow depths. Some steep reflectors are observed for the first time, for example one near the coast, related to high seismicity and another one near the LFZ. Steep shallow reflectivity towards the volcanic arc could be related to a steep west-dipping reflector interpreted as fluids and/or melts, migrating upwards due to material recycling in the continental mantle wedge. The high resolution of the S-velocity model in the first kilometres allowed to identify several sedimentary basins, characterized by very low P- and S-velocities, high Poisson's ratios and possible steep reflectivity. Such high Poisson's ratios are also observed within the oceanic crust, which reaches the seismogenic zone hydrated due to bending-related faulting. It is interpreted to release water until reaching the coast and under the continental mantle wedge. In terms of seismic velocities, the inferred composition and rocks in the continental crust is in agreement with field geology observations at the surface along the proflle. Furthermore, there is no requirement to call on the existence of measurable amounts of present-day fluids above the plate interface in the continental crust of the Coastal Cordillera and the Central Valley in this part of the Chilean convergent margin. A large-scale anisotropy in the continental crust and upper mantle, previously proposed from magnetotelluric studies, is proposed from seismic velocities. However, quantitative studies on this topic in the continental crust of the Chilean seismogenic zone at 38.25°S do not exist to date.},
  language  = {en}
}
@phdthesis{Jensen2018,
  author    = {Jensen, Anders Christian Solberg},
  title     = {Structure and dynamics of amorphous carbonates related to biomineralization},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421691},
  school      = {Universit{\"a}t Potsdam},
  pages     = {138},
  year      = {2018},
  abstract  = {Amorphous calcium carbonate(ACC) is a wide spread biological material found in many organisms, such as sea Urchins and mollusks, where it serves as either a precursor phase for the crystalline biominerals or is stabilized and used in the amorphous state. As ACC readily crystallizes, stabilizers such as anions, cations or macromolecules are often present to avoid or delay unwanted crystallization. Furthermore, additives often control the properties of the materials to suit the specific function needed for the organism. E.g. cystoliths in leaves that scatter light to optimize energy uptake from the sun or calcite/aragonite crystals used in protective shells in mussels and gastropods. Lifetime of the amorphous phase is controlled by the kinetic stability against crystallization. This has often been linked to water which plays a role in the mobility of ions and hence the probability of forming crystalline nuclei to initiate crystallization. However, it is unclear how the water molecules are incorporated within the amorphous phase, either as liquid confined in pores, as structural water binding to the ions or as a mixture of both. It is also unclear how this is perturbed when additives are added, especially Mg2+, one the most common additives found in biogenic samples. Mg2+ are expected to have a strong influence on the water incorporated into ACC, given the high energy barrier to dehydration of magnesium ions compared to calcium ions in solution. During the last 10-15 years, there has been a large effort to understand the local environment of the ions/molecules and how this affects the properties of the amorphous phase. But only a few aspects of the structure have so far been well-described in literature. The reason for this is partly caused by the low stability of ACC if exposed to air, where it tends to crystallize within minutes and by the limited quantities of ACC produced in traditional synthesis routes. A further obstacle has been the difficulty in modeling the local structure based on experimental data. To solve the problem of stability and sample size, a few studies have used stabilizers such as Mg2+ or OH- and severely dehydrated samples so as to stabilize the amorphous state, allowing for combined neutron and x-ray analysis to be performed. However, so far, a clear description of the local environments of water present in the structure has not been reported. In this study we show that ACC can be synthesized without any stabilizing additives in quantities necessary for neutron measurements and that accurate models can be derived with the help of empirical-potential structural refinement. These analyses have shown that there is a wide range of local environments for all of the components in the system suggesting that the amorphous phase is highly inhomogeneous, without any phase separation between ions and water. We also showed that the water in ACC is mainly structural and that there is no confined or liquid-like water present in the system. Analysis of amorphous magnesium carbonate also showed that there is a large difference in the local structure of the two cations and that Mg2+ surprisingly interacts with significantly less water molecules then Ca2+ despite the higher dehydration energy. All in all, this shows that the role of water molecules as a structural component of ACC, with a strong binding to cat- and anions probably retard or prevents the crystallization of the amorphous phase.},
  language  = {en}
}
@phdthesis{RodriguezLoureiro2018,
  author    = {Rodriguez Loureiro, Ignacio},
  title     = {Structural characterization of single and interacting soft interfaces displaying brushes of synthetic or biomolecular polymers},
  doi       = {10.25932/publishup-42367},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-423675},
  school      = {Universit{\"a}t Potsdam},
  pages     = {132},
  year      = {2018},
  abstract  = {The interaction between surfaces displaying end-grafted hydrophilic polymer brushes plays important roles in biology and in many wet-technological applications. The outer surfaces of Gram-negative bacteria, for example, are composed of lipopolysaccharide (LPS) molecules exposing oligo- and polysaccharides to the aqueous environment. This unique, structurally complex biological interface is of great scientific interest as it mediates the interaction of bacteria with neighboring bacteria in colonies and biofilms. The interaction between polymer-decorated surfaces is generally coupled to the distance-dependent conformation of the polymer chains. Therefore, structural insight into the interacting surfaces is a prerequisite to understand the interaction characteristics as well as the underlying physical mechanisms. This problem has been addressed by theory, but accurate experimental data on polymer conformations under confinement are rare, because obtaining perturbation-free structural insight into buried soft interfaces is inherently difficult. In this thesis, lipid membrane surfaces decorated with hydrophilic polymers of technological and biological relevance are investigated under controlled interaction conditions, i.e., at defined surface separations. For this purpose, dedicated sample architectures and experimental tools are developed. Via ellipsometry and neutron reflectometry pressure-distance curves and distance-dependent polymer conformations in terms of brush compression and reciprocative interpenetration are determined. Additional element-specific structural insight into the end-point distribution of interacting brushes is obtained by standing-wave x-ray fluorescence (SWXF). The methodology is first established for poly[ethylene glycol] (PEG) brushes of defined length and grafting density. For this system, neutron reflectometry revealed pronounced brush interpenetration, which is not captured in common brush theories and therefore motivates rigorous simulation-based treatments. In the second step the same approach is applied to realistic mimics of the outer surfaces of Gram-negative bacteria: monolayers of wild type LPSs extracted from E. Coli O55:B5 displaying strain-specific O-side chains. The neutron reflectometry experiments yield unprecedented structural insight into bacterial interactions, which are of great relevance for the properties of biofilms.},
  language  = {en}
}
@phdthesis{Hill2018,
  author    = {Hill, Lukasz},
  title     = {Soziale Integration und politische Partizipation in Demokratien},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420077},
  school      = {Universit{\"a}t Potsdam},
  pages     = {215},
  year      = {2018},
  abstract  = {Die Frage nach dem Zusammenhalt einer ganzen Gesellschaft ist eine der zentralen Fragen der Sozialwissenschaften und Soziologie. Seit dem {\"U}bergang in die Moderne bildet das Problem des Zusammenhalts von sich differenzierenden Gesellschaften den Gegenstand des wissenschaftlichen und gesellschaftlichen Diskurses. In der vorliegenden Studie stellt soziale Integration eine Form der gelungenen Vergesellschaftung dar, die sich in der Reproduktion von symbolischen und nicht-symbolischen Ressourcen artikuliert. Das Resultat dieser Reproduktion sind pluralistische Vergesellschaftungen, die, bezogen auf politische Pr{\"a}ferenzen, konfligierende Interessen verursachen. Diese Pr{\"a}ferenzen kommen in unterschiedlichen Formen, in ihrer Intensit{\"a}t und Wahrnehmung der politischen Partizipation zum Ausdruck. Da moderne politische Herrschaft aufgrund der rechtlichen und institutionellen Ausstattung einen bedeutsamen Einfluss auf soziale Reproduktion aus{\"u}ben kann (z.B. durch Sozialpolitik), stellt direkte Beeinflussung politischer Entscheidungen, als Artikulation von sich aus den Konfliktlinien etablierenden, unterschiedlichen Pr{\"a}ferenzen, das einzige legitime Mittel zwecks Umverteilung von Ressourcen auf der Ebene des Politischen dar. Somit wird die Konnotation zwischen Integration und politischer Partizipation sichtbar. In die Gesellschaft gut integrierte Mitglieder sind aufgrund einer breiten Teilnahme an Reproduktionsprozessen in der Lage, eigene Interessen zu erkennen und durch politische Aktivit{\"a}ten zum Ausdruck zu bringen. Die empirischen Befunde scheinen den Eindruck zu vermitteln, dass der demokratische Konflikt in der modernen Gesellschaft nicht mehr direkt von Klassenzugeh{\"o}rigkeit und Klasseninteressen gepr{\"a}gt wird, sondern durch den Zugang zu und die Verf{\"u}gbarkeit von symbolischen und nicht-symbolischen Ressourcen geformt wird. In der Konsequenz lautet die Fragestellung der vorliegenden Arbeit, ob integrierte Gesellschaften politisch aktiver sind. Die Fragestellung der Arbeit wird mithilfe von Aggregatdaten demokratisch-verfasster politischer Systemen untersucht, die als etablierte Demokratien gelten und unterschiedlich Breite wohlfahrtstaatlichen Maßnahmen aufweisen. Die empirische {\"U}berpr{\"u}fung der Hypothesen erfolgte mithilfe von bivariaten und multivariaten Regressionsanalysen. Die {\"u}berpr{\"u}ften Hypothesen lassen sich folgend in einer Hypothese zusammenfassen: Je st{\"a}rker die soziale Integration einer Gesellschaft, desto gr{\"o}ßer ist die konventionelle bzw. unkonventionelle politische Partizipation. Verallgemeinert ist die Aussage zul{\"a}ssig, dass soziale Integration einer Gesellschaft positive Effekte auf die H{\"a}ufigkeit politischer Partizipation innerhalb dieser Gesellschaft hat. St{\"a}rker integrierte Gesellschaften sind politisch aktiver und dies unabh{\"a}ngig von der Form (konventionelle oder unkonventionelle) politischer Beteiligung. Dabei ist der direkte Effekt der gesamtgesellschaftlichen Integration auf die konventionellen Formen st{\"a}rker als auf unkonventionellen. Diese Aussage ist nur zul{\"a}ssig, wenn die Elemente des Wahlsystems, wie z.B. Verh{\"a}ltniswahlrecht, und das BIP nicht ber{\"u}cksichtigt werden. Auf der Grundlage der Ergebnisse mit Kontrollvariablen erlauben die Daten die auf die Makroebene bezogene Aussage, dass neben einem hohen Niveau sozialer Integration auch ein durch (Mit-)Beteiligung bestimmtes Wahlsystem und ein hoher wirtschaftlicher Entwicklungsgrad beg{\"u}nstigend f{\"u}r ein hohes Niveau politischer Partizipation sind.},
  language  = {de}
}
@phdthesis{Valliappan2018,
  author    = {Valliappan, Senthamizh Pavai},
  title     = {Solar Activity Reconstruction from Historical Observations of Sunspots},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-413600},
  school      = {Universit{\"a}t Potsdam},
  pages     = {115},
  year      = {2018},
  abstract  = {The solar activity and its consequences affect space weather and Earth's climate. The solar activity exhibits a cyclic behaviour with a period of about 11 years. The solar cycle properties are governed by the dynamo taking place in the interior of the Sun, and they are distinctive. Extending the knowledge about solar cycle properties into the past is essential for understanding the solar dynamo and forecasting space weather. It can be acquired through the analysis of historical sunspot drawings. Sunspots are the dark areas, which are associated with strong magnetic fields, on the solar surface. Sunspots are the oldest and longest available observed features of solar activity. One of the longest available records of sunspot drawings is the collection by Samuel Heinrich Schwabe during 1825-1867. The sunspot sizes measured from digitized Schwabe drawings are not to scale and need to be converted into physical sunspot areas. We employed a statistical approach assuming that the area distribution of sunspots was the same in the 19th century as it was in the 20th century. Umbral areas for about 130 000 sunspots observed by Schwabe were obtained. The annually averaged sunspot areas correlate reasonably well with the sunspot number. Tilt angles and polarity separations of sunspot groups were calculated assuming them to be bipolar. There is, of course, no polarity information in the observations. We derived an average tilt angle by attempting to exclude unipolar groups with a minimum separation of the two surmised polarities and an outlier rejection method, which follows the evolution of each group and detects the moment, when it turns unipolar as it decays. As a result, the tilt angles, although displaying considerable natural scatter, are on average 5.85° ± 0.25°, with the leading polarity located closer to the equator, in good agreement with tilt angles obtained from 20th century data sets. Sources of uncertainties in the tilt angle determination are discussed and need to be addressed whenever different data sets are combined. Digital images of observations printed in the books Rosa Ursina and Prodromus pro sole mobili by Christoph Scheiner, as well as the drawings from Scheiner's letters to Marcus Welser, are analyzed to obtain information on the positions and sizes of sunspots that appeared before the Maunder minimum. In most cases, the given orientation of the ecliptic is used to set up the heliographic coordinate system for the drawings. Positions and sizes are measured manually displaying the drawings on a computer screen. Very early drawings have no indication of the solar orientation. A rotational matching using common spots of adjacent days is used in some cases, while in other cases, the assumption that images were aligned with a zenith-horizon coordinate system appeared to be the most likely. In total, 8167 sunspots were measured. A distribution of sunspot latitudes versus time (butterfly diagram) is obtained for Scheiner's observations. The observations of 1611 are very inaccurate, but the drawings of 1612 have at least an indication of the solar orientation, while the remaining part of the spot positions from 1618-1631 have good to very good accuracy. We also computed 697 tilt angles of apparent bipolar sunspot groups, which were observed in the period 1618-1631. We find that the average tilt angle of nearly 4° does not significantly differ from the 20th century values. The solar cycle properties seem to be related to the tilt angles of sunspot groups, and it is an important parameter in the surface flux transport models. The tilt angles of bipolar sunspot groups from various historical sets of solar drawings including from Schwabe and Scheiner are analyzed. Data by Scheiner, Hevelius, Staudacher, Zucconi, Schwabe, and Spörer deliver a series of average tilt angles spanning a period of 270 years, in addition to previously found values for 20th-century data obtained by other authors. We find that the average tilt angles before the Maunder minimum were not significantly different from modern values. However, the average tilt angles of a period 50 years after the Maunder minimum, namely for cycles 0 and 1, were much lower and near zero. The typical tilt angles before the Maunder minimum suggest that abnormally low tilt angles were not responsible for driving the solar cycle into a grand minimum. With the Schwabe (1826-1867) and Spörer (1866-1880) sunspot data, the butterfly diagram of sunspot groups extends back till 1826. A recently developed method, which separates the wings of the butterfly diagram based on the long gaps present in sunspot group occurrences at different latitudinal bands, is used to separate the wings of the butterfly diagram. The cycle-to-cycle variation in the start (F), end (L), and highest (H) latitudes of the wings with respect to the strength of the wings are analyzed. On the whole, the wings of the stronger cycles tend to start at higher latitudes and have a greater extent. The time spans of the wings and the time difference between the wings in the northern hemisphere display a quasi-periodicity of 5-6 cycles. The average wing overlap is zero in the southern hemisphere, whereas it is 2-3 months in the north. A marginally significant oscillation of about 10 solar cycles is found in the asymmetry of the L latitudes. This latest, extended database of butterfly wings provides new observational constraints, regarding the spatio-temporal distribution of sunspot occurrences over the solar cycle, to solar dynamo models.},
  language  = {en}
}
@phdthesis{Tofelde2018,
  author    = {Tofelde, Stefanie},
  title     = {Signals stored in sediment},
  doi       = {10.25932/publishup-42716},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427168},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XVII, 172},
  year      = {2018},
  abstract  = {Tectonic and climatic boundary conditions determine the amount and the characteristics (size distribution and composition) of sediment that is generated and exported from mountain regions. On millennial timescales, rivers adjust their morphology such that the incoming sediment (Qs,in) can be transported downstream by the available water discharge (Qw). Changes in climatic and tectonic boundary conditions thus trigger an adjustment of the downstream river morphology. Understanding the sensitivity of river morphology to perturbations in boundary conditions is therefore of major importance, for example, for flood assessments, infrastructure and habitats. Although we have a general understanding of how rivers evolve over longer timescales, the prediction of channel response to changes in boundary conditions on a more local scale and over shorter timescales remains a major challenge. To better predict morphological channel evolution, we need to test (i) how channels respond to perturbations in boundary conditions and (ii) how signals reflecting the persisting conditions are preserved in sediment characteristics. This information can then be applied to reconstruct how local river systems have evolved over time. In this thesis, I address those questions by combining targeted field data collection in the Quebrada del Toro (Southern Central Andes of NW Argentina) with cosmogenic nuclide analysis and remote sensing data. In particular, I (1) investigate how information on hillslope processes is preserved in the 10Be concentration (geochemical composition) of fluvial sediments and how those signals are altered during downstream transport. I complement the field-based approach with physical experiments in the laboratory, in which I (2) explore how changes in sediment supply (Qs,in) or water discharge (Qw) generate distinct signals in the amount of sediment discharge at the basin outlet (Qs,out). With the same set of experiments, I (3) study the adjustments of alluvial channel morphology to changes in Qw and Qs,in, with a particular focus in fill-terrace formation. I transfer the findings from the experiments to the field to (4) reconstruct the evolution of a several-hundred meter thick fluvial fill-terrace sequence in the Quebrada del Toro. I create a detailed terrace chronology and perform reconstructions of paleo-Qs and Qw from the terrace deposits. In the following paragraphs, I summarize my findings on each of these four topics. First, I sampled detrital sediment at the outlet of tributaries and along the main stem in the Quebrada del Toro, analyzed their 10Be concentration ([10Be]) and compared the data to a detailed hillslope-process inventory. The often observed non-linear increase in catchment-mean denudation rate (inferred from [10Be] in fluvial sediment) with catchment-median slope, which has commonly been explained by an adjustment in landslide-frequency, coincided with a shift in the main type of hillslope processes. In addition, the [10Be] in fluvial sediments varied with grain-size. I defined the normalized sand-gravel-index (NSGI) as the 10Be-concentration difference between sand and gravel fractions divided by their summed concentrations. The NSGI increased with median catchment slope and coincided with a shift in the prevailing hillslope processes active in the catchments, thus making the NSGI a potential proxy for the evolution of hillslope processes over time from sedimentary deposits. However, the NSGI recorded hillslope-processes less well in regions of reduced hillslope-channel connectivity and, in addition, has the potential to be altered during downstream transport due to lateral sediment input, size-selective sediment transport and abrasion. Second, my physical experiments revealed that sediment discharge at the basin outlet (Qs,out) varied in response to changes in Qs,in or Qw. While changes in Qw caused a distinct signal in Qs,out during the transient adjustment phase of the channel to new boundary conditions, signals related to changes in Qs,in were buffered during the transient phase and likely only become apparent once the channel is adjusted to the new conditions. The temporal buffering is related to the negative feedback between Qs,in and channel-slope adjustments. In addition, I inferred from this result that signals extracted from the geochemical composition of sediments (e.g., [10Be]) are more likely to represent modern-day conditions during times of aggradation, whereas the signal will be temporally buffered due to mixing with older, remobilized sediment during times of channel incision. Third, the same set of experiments revealed that river incision, channel-width narrowing and terrace cutting were initiated by either an increase in Qw, a decrease in Qs,in or a drop in base level. The lag-time between the external perturbation and the terrace cutting determined (1) how well terrace surfaces preserved the channel profile prior to perturbation and (2) the degree of reworking of terrace-surface material. Short lag-times and well preserved profiles occurred in cases with a rapid onset of incision. Also, lag-times were synchronous along the entire channel after upstream perturbations (Qw, Qs,in), whereas base-level fall triggered an upstream migrating knickzone, such that lag-times increased with distance upstream. Terraces formed after upstream perturbations (Qw, Qs,in) were always steeper when compared to the active channel in new equilibrium conditions. In the base-level fall experiment, the slope of the terrace-surfaces and the modern channel were similar. Hence, slope comparisons between the terrace surface and the modern channel can give insights into the mechanism of terrace formation. Fourth, my detailed terrace-formation chronology indicated that cut-and-fill episodes in the Quebrada del Toro followed a ~100-kyr cyclicity, with the oldest terraces ~ 500 kyr old. The terraces were formed due to variability in upstream Qw and Qs. Reconstructions of paleo-Qs over the last 500 kyr, which were restricted to times of sediment deposition, indicated only minor (up to four-fold) variations in paleo-denudation rates. Reconstructions of paleo-Qw were limited to the times around the onset of river incision and revealed enhanced discharge from 10 to 85\% compared to today. Such increases in Qw are in agreement with other quantitative paleo-hydrological reconstructions from the Eastern Andes, but have the advantage of dating further back in time.},
  language  = {en}
}
@phdthesis{Vogel2018,
  author    = {Vogel, Stefanie},
  title     = {Sequence dependency of photon and electron induced DNA strand breaks},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419669},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xii, 117},
  year      = {2018},
  abstract  = {Deoxyribonucleic acid (DNA) is the carrier of human genetic information and is exposed to environmental influences such as the ultraviolet (UV) fraction of sunlight every day. The photostability of the DNA against UV light is astonishing. Even if the DNA bases have a strong absorption maximum at around 260 nm/4.77 eV, their quantum yield of photoproducts remains very low 1. If the photon energies exceed the ionization energy (IE) of the nucleobases ( ̴ 8-9 eV) 2, the DNA can be severely damaged. Photoexcitation and -ionization reactions occur, which can induce strand breaks in the DNA. The efficiency of the excitation and ionization induced strand breaks in the target DNA sequences are represented by cross sections. If Si as a substrate material is used in the VUV irradiation experiments, secondary electrons with an energy below 3.6 eV are generated from the substrate. This low energy electrons (LEE) are known to induce dissociative electron attachment (DEA) in DNA and with it DNA strand breakage very efficiently. LEEs play an important role in cancer radiation therapy, since they are generated secondarily along the radiation track of ionizing radiation. In the framework of this thesis, different single stranded DNA sequences were irradiated with 8.44 eV vacuum UV (VUV) light and cross sections for single strand breaks (SSB) were determined. Several sequences were also exposed to secondary LEEs, which additionally contributed to the SSBs. First, the cross sections for SSBs depending on the type of nucleobases were determined. Both types of DNA sequences, mono-nucleobase and mixed sequences showed very similar results upon VUV radiation. The additional influence of secondarily generated LEEs resulted in contrast in a clear trend for the SSB cross sections. In this, the polythymine sequence had the highest cross section for SSBs, which can be explained by strong anionic resonances in this energy range. Furthermore, SSB cross sections were determined as a function of sequence length. This resulted in an increase in the strand breaks to the same extent as the increase in the geometrical cross section. The longest DNA sequence (20 nucleotides) investigated in this series, however, showed smaller cross section values for SSBs, which can be explained by conformational changes in the DNA. Moreover, several DNA sequences that included the radiosensitizers 5-Bromouracil (5BrU) and 8-Bromoadenine (8BrA) were investigated and the corresponding SSB cross sections were determined. It was shown that 5BrU reacts very strongly to VUV radiation leading to high strand break yields, which showed in turn a strong sequence-dependency. 8BrA, on the other hand, showed no sensitization to the applied VUV radiation, since almost no increase in strand breakage yield was observed in comparison to non-modified DNA sequences. In order to be able to identify the mechanisms of radiation damage by photons, the IEs of certain DNA sequences were further explored using photoionization tandem mass spectrometry. By varying the DNA sequence, both the IEs depending on the type of nucleobase as well as on the DNA strand length could be identified and correlated to the SSB cross sections. The influence of the IE on the photoinduced reaction in the brominated DNA sequences could be excluded.},
  language  = {en}
}
@phdthesis{Kruse2018,
  author    = {Kruse, Sebastian},
  title     = {Scalable data profiling},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-412521},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ii, 156},
  year      = {2018},
  abstract  = {Data profiling is the act of extracting structural metadata from datasets. Structural metadata, such as data dependencies and statistics, can support data management operations, such as data integration and data cleaning. Data management often is the most time-consuming activity in any data-related project. Its support is extremely valuable in our data-driven world, so that more time can be spent on the actual utilization of the data, e. g., building analytical models. In most scenarios, however, structural metadata is not given and must be extracted first. Therefore, efficient data profiling methods are highly desirable. Data profiling is a computationally expensive problem; in fact, most dependency discovery problems entail search spaces that grow exponentially in the number of attributes. To this end, this thesis introduces novel discovery algorithms for various types of data dependencies - namely inclusion dependencies, conditional inclusion dependencies, partial functional dependencies, and partial unique column combinations - that considerably improve over state-of-the-art algorithms in terms of efficiency and that scale to datasets that cannot be processed by existing algorithms. The key to those improvements are not only algorithmic innovations, such as novel pruning rules or traversal strategies, but also algorithm designs tailored for distributed execution. While distributed data profiling has been mostly neglected by previous works, it is a logical consequence on the face of recent hardware trends and the computational hardness of dependency discovery. To demonstrate the utility of data profiling for data management, this thesis furthermore presents Metacrate, a database for structural metadata. Its salient features are its flexible data model, the capability to integrate various kinds of structural metadata, and its rich metadata analytics library. We show how to perform a data anamnesis of unknown, complex datasets based on this technology. In particular, we describe in detail how to reconstruct the schemata and assess their quality as part of the data anamnesis. The data profiling algorithms and Metacrate have been carefully implemented, integrated with the Metanome data profiling tool, and are available as free software. In that way, we intend to allow for easy repeatability of our research results and also provide them for actual usage in real-world data-related projects.},
  language  = {en}
}
@phdthesis{Rosenwinkel2018,
  author    = {Rosenwinkel, Swenja},
  title     = {Rock glaciers and natural dams in Central Asia},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-410386},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvii, 181},
  year      = {2018},
  abstract  = {The formation and breaching of natural dammed lakes have formed the landscapes, especially in seismically active high-mountain regions. Dammed lakes pose both, potential water resources, and hazard in case of dam breaching. Central Asia has mostly arid and semi-arid climates. Rock glaciers already store more water than ice-glaciers in some semi-arid regions of the world, but their distribution and advance mechanisms are still under debate in recent research. Their impact on the water availability in Central Asia will likely increase as temperatures rise and glaciers diminish. This thesis provides insight to the relative age distribution of selected Kyrgyz and Kazakh rock glaciers and their single lobes derived from lichenometric dating. The size of roughly 8000 different lichen specimens was used to approximate an exposure age of the underlying debris surface. We showed that rock-glacier movement differs signifcantly on small scales. This has several implications for climatic inferences from rock glaciers. First, reactivation of their lobes does not necessarily point to climatic changes, or at least at out-of-equilibrium conditions. Second, the elevations of rock-glacier toes can no longer be considered as general indicators of the limit of sporadic mountain permafrost as they have been used traditionally. In the mountainous and seismically active region of Central Asia, natural dams, besides rock glaciers, also play a key role in controlling water and sediment infux into river valleys. However, rock glaciers advancing into valleys seem to be capable of infuencing the stream network, to dam rivers, or to impound lakes. This influence has not previously been addressed. We quantitatively explored these controls using a new inventory of 1300 Central Asian rock glaciers. Elevation, potential incoming solar radiation, and the size of rock glaciers and their feeder basins played key roles in predicting dam appearance. Bayesian techniques were used to credibly distinguish between lichen sizes on rock glaciers and their lobes, and to find those parameters of a rock-glacier system that are most credibly expressing the potential to build natural dams. To place these studies in the region's history of natural dams, a combination of dating of former lake levels and outburst flood modelling addresses the history and possible outburst flood hypotheses of the second largest mountain lake of the world, Issyk Kul in Kyrgyzstan. Megafoods from breached earthen or glacial dams were found to be a likely explanation for some of the lake's highly fluctuating water levels. However, our detailed analysis of candidate lake sediments and outburst-flood deposits also showed that more localised dam breaks to the west of Issyk Kul could have left similar geomorphic and sedimentary evidence in this Central Asian mountain landscape. We thus caution against readily invoking megafloods as the main cause of lake-level drops of Issyk Kul. In summary, this thesis addresses some new pathways for studying rock glaciers and natural dams with several practical implications for studies on mountain permafrost and natural hazards.},
  language  = {en}
}
@phdthesis{Sieg2018,
  author    = {Sieg, Tobias},
  title     = {Reliability of flood damage estimations across spatial scales},
  doi       = {10.25932/publishup-42616},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-426161},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XIII, 115},
  year      = {2018},
  abstract  = {Extreme Naturereignisse sind ein integraler Bestandteil der Natur der Erde. Sie werden erst dann zu Gefahren f{\"u}r die Gesellschaft, wenn sie diesen Ereignissen ausgesetzt ist. Dann allerdings k{\"o}nnen Naturgefahren verheerende Folgen f{\"u}r die Gesellschaft haben. Besonders hydro-meteorologische Gefahren wie zum Beispiel Flusshochwasser, Starkregenereignisse, Winterst{\"u}rme, Orkane oder Tornados haben ein hohes Schadenspotential und treten rund um den Globus auf. Einhergehend mit einer immer w{\"a}rmer werdenden Welt, werden auch Extremwetterereignisse, welche potentiell Naturgefahren ausl{\"o}sen k{\"o}nnen, immer wahrscheinlicher. Allerdings tr{\"a}gt nicht nur eine sich ver{\"a}ndernde Umwelt zur Erh{\"o}hung des Risikos von Naturgefahren bei, sondern auch eine sich ver{\"a}ndernde Gesellschaft. Daher ist ein angemessenes Risikomanagement erforderlich um die Gesellschaft auf jeder r{\"a}umlichen Ebene an diese Ver{\"a}nderungen anzupassen. Ein essentieller Bestandteil dieses Managements ist die Absch{\"a}tzung der {\"o}konomischen Auswirkungen der Naturgefahren. Bisher allerdings fehlen verl{\"a}ssliche Methoden um die Auswirkungen von hydro-meteorologischen Gefahren abzusch{\"a}tzen. Ein Hauptbestandteil dieser Arbeit ist daher die Entwicklung und Anwendung einer neuen Methode, welche die Verl{\"a}sslichkeit der Schadenssch{\"a}tzung verbessert. Die Methode wurde beispielhaft zur Sch{\"a}tzung der {\"o}konomischen Auswirkungen eines Flusshochwassers auf einzelne Unternehmen bis hin zu den Auswirkungen auf das gesamte Wirtschaftssystem Deutschlands erfolgreich angewendet. Bestehende Methoden geben meist wenig Information {\"u}ber die Verl{\"a}sslichkeit ihrer Sch{\"a}tzungen. Da diese Informationen Entscheidungen zur Anpassung an das Risiko erleichtern, wird die Verl{\"a}sslichkeit der Schadenssch{\"a}tzungen mit der neuen Methode dargestellt. Die Verl{\"a}sslichkeit bezieht sich dabei nicht nur auf die Schadenssch{\"a}tzung selber, sondern auch auf die Annahmen, die {\"u}ber betroffene Geb{\"a}ude gemacht werden. Nach diesem Prinzip kann auch die Verl{\"a}sslichkeit von Annahmen {\"u}ber die Zukunft dargestellt werden, dies ist ein wesentlicher Aspekt f{\"u}r Prognosen. Die Darstellung der Verl{\"a}sslichkeit und die erfolgreiche Anwendung zeigt das Potential der Methode zur Verwendung von Analysen f{\"u}r gegenw{\"a}rtige und zuk{\"u}nftige hydro-meteorologische Gefahren.},
  language  = {en}
}
@phdthesis{Wendi2018,
  author    = {Wendi, Dadiyorto},
  title     = {Recurrence Plots and Quantification Analysis of Flood Runoff Dynamics},
  doi       = {10.25932/publishup-43191},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-431915},
  school      = {Universit{\"a}t Potsdam},
  pages     = {114},
  year      = {2018},
  abstract  = {This paper introduces a novel measure to assess similarity between event hydrographs. It is based on Cross Recurrence Plots and Recurrence Quantification Analysis which have recently gained attention in a range of disciplines when dealing with complex systems. The method attempts to quantify the event runoff dynamics and is based on the time delay embedded phase space representation of discharge hydrographs. A phase space trajectory is reconstructed from the event hydrograph, and pairs of hydrographs are compared to each other based on the distance of their phase space trajectories. Time delay embedding allows considering the multi-dimensional relationships between different points in time within the event. Hence, the temporal succession of discharge values is taken into account, such as the impact of the initial conditions on the runoff event. We provide an introduction to Cross Recurrence Plots and discuss their parameterization. An application example based on flood time series demonstrates how the method can be used to measure the similarity or dissimilarity of events, and how it can be used to detect events with rare runoff dynamics. It is argued that this methods provides a more comprehensive approach to quantify hydrograph similarity compared to conventional hydrological signatures.},
  language  = {en}
}
@phdthesis{Siegmund2018,
  author    = {Siegmund, Jonatan Frederik},
  title     = {Quantifying impacts of climate extreme events on vegetation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407095},
  school      = {Universit{\"a}t Potsdam},
  pages     = {129},
  year      = {2018},
  abstract  = {Together with the gradual change of mean values, ongoing climate change is projected to increase frequency and amplitude of temperature and precipitation extremes in many regions of Europe. The impacts of such in most cases short term extraordinary climate situations on terrestrial ecosystems are a matter of central interest of recent climate change research, because it can not per se be assumed that known dependencies between climate variables and ecosystems are linearly scalable. So far, yet, there is a high demand for a method to quantify such impacts in terms of simultaneities of event time series. In the course of this manuscript the new statistical approach of Event Coincidence Analysis (ECA) as well as it's R implementation is introduced, a methodology that allows assessing whether or not two types of event time series exhibit similar sequences of occurrences. Applications of the method are presented, analyzing climate impacts on different temporal and spacial scales: the impact of extraordinary expressions of various climatic variables on tree stem variations (subdaily and local scale), the impact of extreme temperature and precipitation events on the owering time of European shrub species (weekly and country scale), the impact of extreme temperature events on ecosystem health in terms of NDVI (weekly and continental scale) and the impact of El Ni{\~n}o and La Ni{\~n}a events on precipitation anomalies (seasonal and global scale). The applications presented in this thesis refine already known relationships based on classical methods and also deliver substantial new findings to the scientific community: the widely known positive correlation between flowering time and temperature for example is confirmed to be valid for the tails of the distributions while the widely assumed positive dependency between stem diameter variation and temperature is shown to be not valid for very warm and very cold days. The larger scale investigations underline the sensitivity of anthrogenically shaped landscapes towards temperature extremes in Europe and provide a comprehensive global ENSO impact map for strong precipitation events. Finally, by publishing the R implementation of the method, this thesis shall enable other researcher to further investigate on similar research questions by using Event Coincidence Analysis.},
  language  = {en}
}
@phdthesis{Kotha2018,
  author    = {Kotha, Sreeram Reddy},
  title     = {Quantification of uncertainties in seismic ground-motion prediction},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-415743},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xii, 101},
  year      = {2018},
  abstract  = {The purpose of Probabilistic Seismic Hazard Assessment (PSHA) at a construction site is to provide the engineers with a probabilistic estimate of ground-motion level that could be equaled or exceeded at least once in the structure's design lifetime. A certainty on the predicted ground-motion allows the engineers to confidently optimize structural design and mitigate the risk of extensive damage, or in worst case, a collapse. It is therefore in interest of engineering, insurance, disaster mitigation, and security of society at large, to reduce uncertainties in prediction of design ground-motion levels. In this study, I am concerned with quantifying and reducing the prediction uncertainty of regression-based Ground-Motion Prediction Equations (GMPEs). Essentially, GMPEs are regressed best-fit formulae relating event, path, and site parameters (predictor variables) to observed ground-motion values at the site (prediction variable). GMPEs are characterized by a parametric median (μ) and a non-parametric variance (σ) of prediction. μ captures the known ground-motion physics i.e., scaling with earthquake rupture properties (event), attenuation with distance from source (region/path), and amplification due to local soil conditions (site); while σ quantifies the natural variability of data that eludes μ. In a broad sense, the GMPE prediction uncertainty is cumulative of 1) uncertainty on estimated regression coefficients (uncertainty on μ,σ_μ), and 2) the inherent natural randomness of data (σ). The extent of μ parametrization, the quantity, and quality of ground-motion data used in a regression, govern the size of its prediction uncertainty: σ_μ and σ. In the first step, I present the impact of μ parametrization on the size of σ_μ and σ. Over-parametrization appears to increase the σ_μ, because of the large number of regression coefficients (in μ) to be estimated with insufficient data. Under-parametrization mitigates σ_μ, but the reduced explanatory strength of μ is reflected in inflated σ. For an optimally parametrized GMPE, a ~10\% reduction in σ is attained by discarding the low-quality data from pan-European events with incorrect parametric values (of predictor variables). In case of regions with scarce ground-motion recordings, without under-parametrization, the only way to mitigate σ_μ is to substitute long-term earthquake data at a location with short-term samples of data across several locations - the Ergodic Assumption. However, the price of ergodic assumption is an increased σ, due to the region-to-region and site-to-site differences in ground-motion physics. σ of an ergodic GMPE developed from generic ergodic dataset is much larger than that of non-ergodic GMPEs developed from region- and site-specific non-ergodic subsets - which were too sparse to produce their specific GMPEs. Fortunately, with the dramatic increase in recorded ground-motion data at several sites across Europe and Middle-East, I could quantify the region- and site-specific differences in ground-motion scaling and upgrade the GMPEs with 1) substantially more accurate region- and site-specific μ for sites in Italy and Turkey, and 2) significantly smaller prediction variance σ. The benefit of such enhancements to GMPEs is quite evident in my comparison of PSHA estimates from ergodic versus region- and site-specific GMPEs; where the differences in predicted design ground-motion levels, at several sites in Europe and Middle-Eastern regions, are as large as ~50\%. Resolving the ergodic assumption with mixed-effects regressions is feasible when the quantified region- and site-specific effects are physically meaningful, and the non-ergodic subsets (regions and sites) are defined a priori through expert knowledge. In absence of expert definitions, I demonstrate the potential of machine learning techniques in identifying efficient clusters of site-specific non-ergodic subsets, based on latent similarities in their ground-motion data. Clustered site-specific GMPEs bridge the gap between site-specific and fully ergodic GMPEs, with their partially non-ergodic μ and, σ ~15\% smaller than the ergodic variance. The methodological refinements to GMPE development produced in this study are applicable to new ground-motion datasets, to further enhance certainty of ground-motion prediction and thereby, seismic hazard assessment. Advanced statistical tools show great potential in improving the predictive capabilities of GMPEs, but the fundamental requirement remains: large quantity of high-quality ground-motion data from several sites for an extended time-period.},
  language  = {en}
}
@phdthesis{Knospe2018,
  author    = {Knospe, Gloria-Mona},
  title     = {Processing of pronouns and reflexives in Turkish-German bilinguals},
  doi       = {10.25932/publishup-43644},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-436442},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxii, 410},
  year      = {2018},
  abstract  = {Previous studies on native language (L1) anaphor resolution have found that monolingual native speakers are sensitive to syntactic, pragmatic, and semantic constraints on pronouns and reflexive resolution. However, most studies have focused on English and other Germanic languages, and little is currently known about the online (i.e., real-time) processing of anaphors in languages with syntactically less restricted anaphors, such as Turkish. We also know relatively little about how 'non-standard' populations such as non-native (L2) speakers and heritage speakers (HSs) resolve anaphors. This thesis investigates the interpretation and real-time processing of anaphors in German and in a typologically different and as yet understudied language, Turkish. It compares hypotheses about differences between native speakers' (L1ers) and L2 speakers' (L2ers) sentence processing, looking into differences in processing mechanisms as well as the possibility of cross-linguistic influence. To help fill the current research gap regarding HS sentence comprehension, it compares findings for this group with those for L2ers. To investigate the representation and processing of anaphors in these three populations, I carried out a series of offline questionnaires and Visual-World eye-tracking experiments on the resolution of reflexives and pronouns in both German and Turkish. In the German experiments, native German speakers as well as L2ers of German were tested, while in the Turkish experiments, non-bilingual native Turkish speakers as well as HSs of Turkish with L2 German were tested. This allowed me to observe both cross-linguistic differences as well as population differences between monolinguals' and different types of bilinguals' resolution of anaphors. Regarding the comprehension of Turkish anaphors by L1ers, contrary to what has been previously assumed, I found that Turkish has no reflexive that follows Condition A of Binding theory (Chomsky, 1981). Furthermore, I propose more general cross-linguistic differences between Turkish and German, in the form of a stronger reliance on pragmatic information in anaphor resolution overall in Turkish compared to German. As for the processing differences between L1ers and L2ers of a language, I found evidence in support of hypotheses which propose that L2ers of German rely more strongly on non-syntactic information compared to L1ers (Clahsen \& Felser, 2006, 2017; Cunnings, 2016, 2017) independent of a potential influence of their L1. HSs, on the other hand, showed a tendency to overemphasize interpretational contrasts between different Turkish anaphors compared to monolingual native speakers. However, lower-proficiency HSs were likely to merge different forms for simplified representation and processing. Overall, L2ers and HSs showed differences from monolingual native speakers both in their final interpretation of anaphors and during online processing. However, these differences were not parallel between the two types of bilingual and thus do not support a unified model of L2 and HS processing (cf. Montrul, 2012). The findings of this thesis contribute to the field of anaphor resolution by providing data from a previously unexplored language, Turkish, as well as contributing to research on native and non-native processing differences. My results also illustrate the importance of considering individual differences in the acquisition process when studying bilingual language comprehension. Factors such as age of acquisition, language proficiency and the type of input a language learner receives may influence the processing mechanisms they develop and employ, both between and within different bilingual populations.},
  language  = {en}
}
@phdthesis{Li2018,
  author    = {Li, Lina},
  title     = {Preparation of novel photoactive materials},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-410952},
  school      = {Universit{\"a}t Potsdam},
  pages     = {105},
  year      = {2018},
  abstract  = {Photocatalysis is considered significant in this new energy era, because the inexhaustibly abundant, clean, and safe energy of the sun can be harnessed for sustainable, nonhazardous, and economically development of our society. In the research of photocatalysis, the current focus was held by the design and modification of photocatalyst. As one of the most promising photocatalysts, g-C3N4 has gained considerable attention for its eye-catching properties. It has been extensively explored in photocatalysis applications, such as water splitting, organic pollutant degradation, and CO2 reduction. Even so, it also has its own drawbacks which inhibit its further application. Inspired by that, this thesis will mainly present and discuss the process and achievement on the preparation of some novel photocatalysts and their photocatalysis performance. These materials were all synthesized via the alteration of classic g-C3N4 preparation method, like using different pre-compositions for initial supramolecular complex and functional group post-modification. By taking place of cyanuric acid, 2,5-Dihydroxy-1,4-benzoquinone and chloranilic acid can form completely new supramolecular complex with melamine. After heating, the resulting products of the two complex shown 2D sheet-like and 1D fiber-like morphologies, respectively, which maintain at even up to high temperature of 800 °C. These materials cover crystals, polymers and N-doped carbons with the increase of synthesis temperature. Based on their different pre-compositions, they show different dye degradation performances. For CLA-M-250, it shows the highest photocatalytic activity and strong oxidation capacity. It shows not only great photo-performance in RhB degradation, but also oxygen production in water splitting. In the post-modification method, a novel photocatalysis solution was proposed to modify carbon nitride scaffold with cyano group, whose content can be well controlled by the input of sodium thiocyanate. The cyanation modification leads to narrowed band gap as well as improved photo-induced charges separation. Cyano group grafted carbon nitride thus shows dramatically enhanced performance in the photocatalytic coupling reaction between styrene and sodium benzenesulfinate under green light irradiation, which is in stark contrast with the inactivity of pristine g-C3N4.},
  language  = {en}
}
@phdthesis{Roezer2018,
  author    = {R{\"o}zer, Viktor},
  title     = {Pluvial flood loss to private households},
  doi       = {10.25932/publishup-42991},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-429910},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XXII, 109},
  year      = {2018},
  abstract  = {Today, more than half of the world's population lives in urban areas. With a high density of population and assets, urban areas are not only the economic, cultural and social hubs of every society, they are also highly susceptible to natural disasters. As a consequence of rising sea levels and an expected increase in extreme weather events caused by a changing climate in combination with growing cities, flooding is an increasing threat to many urban agglomerations around the globe. To mitigate the destructive consequences of flooding, appropriate risk management and adaptation strategies are required. So far, flood risk management in urban areas is almost exclusively focused on managing river and coastal flooding. Often overlooked is the risk from small-scale rainfall-triggered flooding, where the rainfall intensity of rainstorms exceeds the capacity of urban drainage systems, leading to immediate flooding. Referred to as pluvial flooding, this flood type exclusive to urban areas has caused severe losses in cities around the world. Without further intervention, losses from pluvial flooding are expected to increase in many urban areas due to an increase of impervious surfaces compounded with an aging drainage infrastructure and a projected increase in heavy precipitation events. While this requires the integration of pluvial flood risk into risk management plans, so far little is known about the adverse consequences of pluvial flooding due to a lack of both detailed data sets and studies on pluvial flood impacts. As a consequence, methods for reliably estimating pluvial flood losses, needed for pluvial flood risk assessment, are still missing. Therefore, this thesis investigates how pluvial flood losses to private households can be reliably estimated, based on an improved understanding of the drivers of pluvial flood loss. For this purpose, detailed data from pluvial flood-affected households was collected through structured telephone- and web-surveys following pluvial flood events in Germany and the Netherlands. Pluvial flood losses to households are the result of complex interactions between impact characteristics such as the water depth and a household's resistance as determined by its risk awareness, preparedness, emergency response, building properties and other influencing factors. Both exploratory analysis and machine-learning approaches were used to analyze differences in resistance and impacts between households and their effects on the resulting losses. The comparison of case studies showed that the awareness around pluvial flooding among private households is quite low. Low awareness not only challenges the effective dissemination of early warnings, but was also found to influence the implementation of private precautionary measures. The latter were predominately implemented by households with previous experience of pluvial flooding. Even cases where previous flood events affected a different part of the same city did not lead to an increase in preparedness of the surveyed households, highlighting the need to account for small-scale variability in both impact and resistance parameters when assessing pluvial flood risk. While it was concluded that the combination of low awareness, ineffective early warning and the fact that only a minority of buildings were adapted to pluvial flooding impaired the coping capacities of private households, the often low water levels still enabled households to mitigate or even prevent losses through a timely and effective emergency response. These findings were confirmed by the detection of loss-influencing variables, showing that cases in which households were able to prevent any loss to the building structure are predominately explained by resistance variables such as the household's risk awareness, while the degree of loss is mainly explained by impact variables. Based on the important loss-influencing variables detected, different flood loss models were developed. Similar to flood loss models for river floods, the empirical data from the preceding data collection was used to train flood loss models describing the relationship between impact and resistance parameters and the resulting loss to building structures. Different approaches were adapted from river flood loss models using both models with the water depth as only predictor for building structure loss and models incorporating additional variables from the preceding variable detection routine. The high predictive errors of all compared models showed that point predictions are not suitable for estimating losses on the building level, as they severely impair the reliability of the estimates. For that reason, a new probabilistic framework based on Bayesian inference was introduced that is able to provide predictive distributions instead of single loss estimates. These distributions not only give a range of probable losses, they also provide information on how likely a specific loss value is, representing the uncertainty in the loss estimate. Using probabilistic loss models, it was found that the certainty and reliability of a loss estimate on the building level is not only determined by the use of additional predictors as shown in previous studies, but also by the choice of response distribution defining the shape of the predictive distribution. Here, a mix between a beta and a Bernoulli distribution to account for households that are able to prevent losses to their building's structure was found to provide significantly more certain and reliable estimates than previous approaches using Gaussian or non-parametric response distributions. The successful model transfer and post-event application to estimate building structure loss in Houston, TX, caused by pluvial flooding during Hurricane Harvey confirmed previous findings, and demonstrated the potential of the newly developed multi-variable beta model for future risk assessments. The highly detailed input data set constructed from openly available data sources containing over 304,000 affected buildings in Harris County further showed the potential of data-driven, building-level loss models for pluvial flood risk assessment. In conclusion, pluvial flood losses to private households are the result of complex interactions between impact and resistance variables, which should be represented in loss models. The local occurrence of pluvial floods requires loss estimates on high spatial resolutions, i.e. on the building level, where losses are variable and uncertainties are high. Therefore, probabilistic loss estimates describing the uncertainty of the estimate should be used instead of point predictions. While the performance of probabilistic models on the building level are mainly driven by the choice of response distribution, multi-variable models are recommended for two reasons: First, additional resistance variables improve the detection of cases in which households were able to prevent structural losses. Second, the added variability of additional predictors provides a better representation of the uncertainties when loss estimates from multiple buildings are aggregated. This leads to the conclusion that data-driven probabilistic loss models on the building level allow for a reliable loss estimation at an unprecedented level of detail, with a consistent quantification of uncertainties on all aggregation levels. This makes the presented approach suitable for a wide range of applications, from decision support in spatial planning to impact- based early warning systems.},
  language  = {en}
}
@phdthesis{Rafighi2018,
  author    = {Rafighi, Iman},
  title     = {Plasma Instabilities from blazar-induced pair beams propagating through IGM},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417428},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ix, 114},
  year      = {2018},
  abstract  = {Modern gamma-ray telescopes, provide the main stream of data for astrophysicists in quest of detecting the sources of gamma rays such as active galactic nuclei (AGN). Many blazars have been detected with gamma-ray telescopes such as HESS, VERITAS, MAGIC and Fermi satellite as sources of gamma-rays with the energy E ≥ 100 GeV. These very-high-energy photons interact with extragalactic background light (EBL) producing ultra-relativistic electron-positron pairs. Observations with Fermi-LAT indicate that the GeV gamma-ray flux from some blazars is lower than that predicted from the full electromagnetic cascade. The pairs can induce electrostatic and electromagnetic instabilities. In this case, wave-particle interactions can reduce the energy of the pairs. Therefore, the collective plasma effects can also substantially suppress the GeV-band gamma-ray emission affecting as well the IGMF constraints. Using Particle in cell (PIC) simulations, we have revisited the issue of plasma instabilities induced by electron-positron beams in the fully ionized intergalactic medium. This problem is related to pair beams produced by TeV radiation of blazars. The main objective of our study is to clarify the feedback of the beam-driven instabilities on the pairs. The present dissertation provides new results regarding the plasma instabilities from blazar induced pair beams interacting with intergalactic medium. This clarifies the relevance of plasma instabilities and improves our understanding of blazars.},
  language  = {en}
}
@phdthesis{Naseri2018,
  author    = {Naseri, Gita},
  title     = {Plant-derived transcription factors and their application for synthetic biology approaches in Saccharomyces cerevisiae},
  doi       = {10.25932/publishup-42151},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421514},
  school      = {Universit{\"a}t Potsdam},
  pages     = {187},
  year      = {2018},
  abstract  = {Bereits seit 9000 Jahren verwendet die Menschheit die B{\"a}ckerhefe Saccharomyces cerevisiae f{\"u}r das Brauen von Bier, aber erst seit 150 Jahren wissen wir, dass es sich bei diesem unerm{\"u}dlichen Helfer im Brauprozess um einzellige, lebende Organismen handelt. Und die B{\"a}ckerhefe kann noch viel mehr. Im Rahmen des Forschungsgebietes der Synthetischen Biologie soll unter anderem die B{\"a}ckerhefe als innovatives Werkzeug f{\"u}r die biobasierte Herstellung verschiedenster Substanzen etabliert werden. Zu diesen Substanzen z{\"a}hlen unter anderem Feinchemikalien, Biokraftstoffe und Biopolymere sowie pharmakologisch und medizinisch interessante Pflanzenstoffe. Damit diese verschiedensten Substanzen in der B{\"a}ckerhefe hergestellt werden k{\"o}nnen, m{\"u}ssen große Mengen an Produktionsinformationen zum Beispiel aus Pflanzen in die Hefezellen {\"u}bertragen werden. Dar{\"u}ber hinaus m{\"u}ssen die neu eingebrachten Biosynthesewege reguliert und kontrolliert in den Zellen ablaufen. Auch Optimierungsprozesse zur Erh{\"o}hung der Produktivit{\"a}t sind notwendig. F{\"u}r alle diese Arbeitsschritte mangelt es bis heute an anwendungsbereiten Technologien und umfassenden Plattformen. Daher wurden im Rahmen dieser Doktorarbeit verschiedene Technologien und Plattformen zur Informations{\"u}bertragung, Regulation und Prozessoptimierung geplant und erzeugt. F{\"u}r die Konstruktion von Biosynthesewegen in der B{\"a}ckerhefe wurde als erstes eine Plattform aus neuartigen Regulatoren und Kontrollelementen auf der Basis pflanzlicher Kontrollelemente generiert und charakterisiert. Im zweiten Schritt erfolgte die Entwicklung einer Technologie zur kombinatorischen Verwendung der Regulatoren in der Planung und Optimierung von Biosynthesewegen (COMPASS). Abschließend wurde eine Technologie f{\"u}r die Prozessoptimierung der ver{\"a}nderten Hefezellen entwickelt (CapRedit). Die Leistungsf{\"a}higkeit der entwickelten Plattformen und Technologien wurde durch eine Optimierung der Produktion von Carotenoiden (Beta-Carotin und Beta-Ionon) und Flavonoiden (Naringenin) in Hefezellen nachgewiesen. Die im Rahmen der Arbeit etablierten neuartigen Plattformen und innovativen Technologien sind ein wertvoller Grundbaustein f{\"u}r die Erweiterung der Nutzbarkeit der B{\"a}ckerhefe. Sie erm{\"o}glichen den Einsatz der Hefezellen in kosteneffizienten Produktionswegen und alternativen chemischen Wertsch{\"o}pfungsketten. Dadurch k{\"o}nnen zum Beispiel Biokraftstoffe und pharmakologisch interessante Pflanzenstoffe unter Verwendung von nachwachsenden Rohstoffen, Reststoffen und Nebenprodukten hergestellt werden. Dar{\"u}ber hinaus ergeben sich Anwendungsm{\"o}glichkeiten zur Bodensanierung und Wasseraufbereitung.},
  language  = {en}
}
@phdthesis{Fuhrmann2018,
  author    = {Fuhrmann, Saskia},
  title     = {Physiologically-based pharmacokinetic and mechanism-based pharmacodynamic modelling of monoclonal antibodies with a focus on tumour targeting},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418861},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvii, 171},
  year      = {2018},
  abstract  = {Monoclonal antibodies (mAbs) are an innovative group of drugs with increasing clinical importance in oncology, combining high specificity with generally low toxicity. There are, however, numerous challenges associated with the development of mAbs as therapeutics. Mechanistic understanding of factors that govern the pharmacokinetics (PK) of mAbs is critical for drug development and the optimisation of effective therapies; in particular, adequate dosing strategies can improve patient quality life and lower drug cost. Physiologically-based PK (PBPK) models offer a physiological and mechanistic framework, which is of advantage in the context of animal to human extrapolation. Unlike for small molecule drugs, however, there is no consensus on how to model mAb disposition in a PBPK context. Current PBPK models for mAb PK hugely vary in their representation of physiology and parameterisation. Their complexity poses a challenge for their applications, e.g., translating knowledge from animal species to humans. In this thesis, we developed and validated a consensus PBPK model for mAb disposition taking into account recent insights into mAb distribution (antibody biodistribution coefficients and interstitial immunoglobulin G (IgG) pharmacokinetics) to predict tissue PK across several pre-clinical species and humans based on plasma data only. The model allows to a priori predict target-independent (unspecific) mAb disposition processes as well as mAb disposition in concentration ranges, for which the unspecific clearance (CL) dominates target-mediated CL processes. This is often the case for mAb therapies at steady state dosing. The consensus PBPK model was then used and refined to address two important problems: 1) Immunodeficient mice are crucial models to evaluate mAb efficacy in cancer therapy. Protection from elimination by binding to the neonatal Fc receptor is known to be a major pathway influencing the unspecific CL of both, endogenous and therapeutic IgG. The concentration of endogenous IgG, however, is reduced in immunodeficient mouse models, and this effect on unspecific mAb CL is unknown, yet of great importance for the extrapolation to human in the context of mAb cancer therapy. 2) The distribution of mAbs into solid tumours is of great interest. To comprehensively investigate mAb distribution within tumour tissue and its implications for therapeutic efficacy, we extended the consensus PBPK model by a detailed tumour distribution model incorporating a cell-level model for mAb-target interaction. We studied the impact of variations in tumour microenvironment on therapeutic efficacy and explored the plausibility of different mechanisms of action in mAb cancer therapy. The mathematical findings and observed phenomena shed new light on therapeutic utility and dosing regimens in mAb cancer treatment.},
  language  = {en}
}
@phdthesis{Riedel2018,
  author    = {Riedel, Marc},
  title     = {Photonic wiring of enzymatic reactions to photoactive entities for the construction of biohybrid electrodes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417280},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VIII, 168},
  year      = {2018},
  abstract  = {In this work, different strategies for the construction of biohybrid photoelectrodes are investigated and have been evaluated according to their intrinsic catalytic activity for the oxidation of the cofactor NADH or for the connection with the enzymes PQQ glucose dehydrogenase (PQQ-GDH), FAD-dependent glucose dehydrogenase (FAD-GDH) and fructose dehydrogenase (FDH). The light-controlled oxidation of NADH has been analyzed with InGaN/GaN nanowire-modified electrodes. Upon illumination with visible light the InGaN/GaN nanowires generate an anodic photocurrent, which increases in a concentration-dependent manner in the presence of NADH, thus allowing determination of the cofactor. Furthermore, different approaches for the connection of enzymes to quantum dot (QD)-modified electrodes via small redox molecules or redox polymers have been analyzed and discussed. First, interaction studies with diffusible redox mediators such as hexacyanoferrate(II) and ferrocenecarboxylic acid have been performed with CdSe/ZnS QD-modified gold electrodes to build up photoelectrochemical signal chains between QDs and the enzymes FDH and PQQ-GDH. In the presence of substrate and under illumination of the electrode, electrons are transferred from the enzyme via the redox mediators to the QDs. The resulting photocurrent is dependent on the substrate concentration and allows a quantification of the fructose and glucose content in solution. A first attempt with immobilized redox mediator, i.e. ferrocenecarboxylic acid chemically coupled to PQQ-GDH and attached to QD-modified gold electrodes, reveal the potential to build up photoelectrochemical signal chains even without diffusible redox mediators in solution. However, this approach results in a significant deteriorated photocurrent response compared to the situation with diffusing mediators. In order to improve the photoelectrochemical performance of such redox mediator-based, light-switchable signal chains, an osmium complex-containing redox polymer has been evaluated as electron relay for the electronic linkage between QDs and enzymes. The redox polymer allows the stable immobilization of the enzyme and the efficient wiring with the QD-modified electrode. In addition, a 3D inverse opal TiO2 (IO-TiO2) electrode has been used for the integration of PbS QDs, redox polymer and FAD-GDH in order to increase the electrode surface. This results in a significantly improved photocurrent response, a quite low onset potential for the substrate oxidation and a broader glucose detection range as compared to the approach with ferrocenecarboxylic acid and PQQ-GDH immobilized on CdSe/ZnS QD-modified gold electrodes. Furthermore, IO-TiO2 electrodes are used to integrate sulfonated polyanilines (PMSA1) and PQQ-GDH, and to investigate the direct interaction between the polymer and the enzyme for the light-switchable detection of glucose. While PMSA1 provides visible light excitation and ensures the efficient connection between the IO-TiO2 electrode and the biocatalytic entity, PQQ-GDH enables the oxidation of glucose. Here, the IO-TiO2 electrodes with pores of approximately 650 nm provide a suitable interface and morphology, which is required for a stable and functional assembly of the polymer and enzyme. The successful integration of the polymer and the enzyme can be confirmed by the formation of a glucose-dependent anodic photocurrent. In conclusion, this work provides insights into the design of photoelectrodes and presents different strategies for the efficient coupling of redox enzymes to photoactive entities, which allows for light-directed sensing and provides the basis for the generation of power from sun light and energy-rich compounds.},
  language  = {en}
}
@phdthesis{Kox2018,
  author    = {Kox, Thomas},
  title     = {Perception and use of uncertainty in severe weather warnings},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-411541},
  school      = {Universit{\"a}t Potsdam},
  pages     = {154},
  year      = {2018},
  abstract  = {Uncertainty is an essential part of atmospheric processes and thus inherent to weather forecasts. Nevertheless, weather forecasts and warnings are still predominately issued as deterministic (yes or no) forecasts, although research suggests that providing weather forecast users with additional information about the forecast uncertainty can enhance the preparation of mitigation measures. Communicating forecast uncertainty would allow for a provision of information on possible future events at an earlier time. The desired benefit is to enable the users to start with preparatory protective action at an earlier stage of time based on the their own risk assessment and decision threshold. But not all users have the same threshold for taking action. In the course of the project WEXICOM ('Wetterwarnungen: Von der Extremereignis-Information zu Kommunikation und Handlung') funded by the Deutscher Wetterdienst (DWD), three studies were conducted between the years 2012 and 2016 to reveal how weather forecasts and warnings are reflected in weather-related decision-making. The studies asked which factors influence the perception of forecasts and the decision to take protective action and how forecast users make sense of probabilistic information and the additional lead time. In a first exploratory study conducted in 2012, members of emergency services in Germany were asked questions about how weather warnings are communicated to professional endusers in the emergency community and how the warnings are converted into mitigation measures. A large number of open questions were selected to identify new topics of interest. The questions covered topics like users' confidence in forecasts, their understanding of probabilistic information as well as their lead time and decision thresholds to start with preparatory mitigation measures. Results show that emergency service personnel generally have a good sense of uncertainty inherent in weather forecasts. Although no single probability threshold could be identified for organisations to start with preparatory mitigation measures, it became clear that emergency services tend to avoid forecasts based on low probabilities as a basis for their decisions. Based on this findings, a second study conducted with residents of Berlin in 2014 further investigated the question of decision thresholds. The survey questions related to the topics of the perception of and prior experience with severe weather, trustworthiness of forecasters and confidence in weather forecasts, and socio-demographic and social-economic characteristics. Within the questionnaire a scenario was created to determine individual decision thresholds and see whether subgroups of the sample lead to different thresholds. The results show that people's willingness to act tends to be higher and decision thresholds tend to be lower if the expected weather event is more severe or the property at risk is of higher value. Several influencing factors of risk perception have significant effects such as education, housing status and ability to act, whereas socio-demographic determinants alone are often not sufficient to fully grasp risk perception and protection behaviour. Parallel to the quantitative studies, an interview study was conducted with 27 members of German civil protection between 2012 and 2016. The results show that the latest developments in (numerical) weather forecasting do not necessarily fit the current practice of German emergency services. These practices are mostly carried out on alarms and ground truth in a reactive manner rather than on anticipation based on prognosis or forecasts. As the potential consequences rather than the event characteristics determine protective action, the findings support the call and need for impact-based warnings. Forecasters will rely on impact data and need to learn the users' understanding of impact. Therefore, it is recommended to enhance weather communication not only by improving computer models and observation tools, but also by focusing on the aspects of communication and collaboration. Using information about uncertainty demands awareness about and acceptance of the limits of knowledge, hence, the capabilities of the forecaster to anticipate future developments of the atmosphere and the capabilities of the user to make sense of this information.},
  language  = {en}
}
@phdthesis{Arora2018,
  author    = {Arora, Ashima},
  title     = {Optical and electric field control of magnetism},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421479},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ii, 126},
  year      = {2018},
  abstract  = {Future magnetic recording industry needs a high-density data storage technology. However, switching the magnetization of small bits requires high magnetic fields that cause excessive heat dissipation. Therefore, controlling magnetism without applying external magnetic field is an important research topic for potential applications in data storage devices with low power consumption. Among the different approaches being investigated, two of them stand out, namely i) all-optical helicity dependent switching (AO-HDS) and ii) ferroelectric control of magnetism. This thesis aims to contribute towards a better understanding of the physical processes behinds these effects as well as reporting new and exciting possibility for the optical and/or electric control of magnetic properties. Hence, the thesis contains two differentiated chapters of results; the first devoted to AO-HDS on TbFe alloys and the second to the electric field control of magnetism in an archetypal Fe/BaTiO3 system. In the first part, the scalability of the AO-HDS to small laser spot-sizes of few microns in the ferrimagnetic TbFe alloy is investigated by spatially resolving the magnetic contrast with photo-emission electron microscopy (PEEM) and X-ray magnetic circular dichroism (XMCD). The results show that the AO-HDS is a local effect within the laser spot size that occurs in the ring-shaped region in the vicinity of thermal demagnetization. Within the ring region, the helicity dependent switching occurs via thermally activated domain wall motion. Further, the thesis reports on a novel effect of thickness dependent inversion of the switching orientation. It addresses some of the important questions like the role of laser heating and the microscopic mechanism driving AO-HDS. The second part of the thesis focuses on the electric field control of magnetism in an artificial multiferroic heterostructure. The sample consists of an Fe wedge with thickness varying between 0:5 nm and 3 nm, deposited on top of a ferroelectric and ferroelastic BaTiO3 [001]-oriented single crystal substrate. Here, the magnetic contrast is imaged via PEEM and XMCD as a function of out-of-plane voltage. The results show the evidence of the electric field control of superparamagnetism mediated by a ferroelastic modification of the magnetic anisotropy. The changes in the magnetoelastic anisotropy drive the transition from the superparamagnetic to superferromagnetic state at localized sample positions.},
  language  = {en}
}
@phdthesis{Hain2018,
  author    = {Hain, Gerrit},
  title     = {Onsets and dependencies of strenuous spine bending accelerations in drop landings},
  doi       = {10.25932/publishup-42746},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427461},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XVI, 118},
  year      = {2018},
  abstract  = {BACKGROUND: Physical activity involving high spinal load has been exposed to possess a crucial impact in the genesis of acute and chronic low back pain and disorder. Vigorous spinal loads are surmised in drop landings, for which strenuous bending loads were formerly evinced for the lower extremity structures. Thus far, clinical studies revealed that repetitive landing impacts can evoke benign structural adaptions or damage to the lumbar vertebrae. Though, causes for these observations are hitherto not conclusively evinced; since actual spinal load has to date not been experimentally documented. Moreover, it is yet undetermined how physiological activation of trunk musculature compensates for landing impact induced spinal loads, and to which extend trunk activity and spinal load are affected by landing demands and performer characteristics. AIMS of this study are 1. the localisation and quantification of spinal bending loads under various landing demands and 2. the identification of compensatory trunk muscular activity pattern, which potentially alleviate spinal load magnitudes. Three consecutive Hypotheses (H1 - H3) were hereto postulated: H1 posits that spinal bending loads in segregated motion planes can feasibly and reliably be evaluated from peak spine segmental angular accelerations. H2 furthermore assumes that vertical drop landings elicit highest spine bending load in sagittal flexion of the lumbar spine. Based on these verifications, a second study shall prove the successive hypothesis (H3) that diversified landing conditions, like performer's landing familiarity and gender, as an implementation of an instantaneous follow-up task, affect the emerging lumbar spinal bending load. Herein it is moreover surmised that lumbar spinal bending loads under distinct landing conditions are predominantly modulated by herewith disparately deployed conditioned pre-activations of trunk muscles. METHODS: To test the above arrayed hypothesis, two successive studies were carried out. In STUDY 1, 17 subjects were repetitively assessed performing various drop landings (heigth: 15, 30, 45, 60cm; unilateral, bilateral, blindfolded, catching a ball) in a test-retest-design. Herein individual peak angular accelerations [αMAX] were derived from three-dimensional motion data of four trunk-segments (upper thoracic, lower thoracic, lumbar, pelvis). αMAX was herein assessed in flexion, lateral flexion, and rotation of each spinal joint, formed by two adjacent segments. Reliability of αMAX within and between test-days was evaluated by CV\%, ICC 2.1, TRV\%, and Bland \& Altman Analysis (BIAS±LoA). Subsequently, peak flexion acceleration of the lumbo-pelvic joint [αFLEX[LS-PV]] was statistically compared to αMAX expressions of each other assessed spinal joint and motion plane (Mean ±SD, Independent Samples T-test). STUDY 2 deliberately assessed mere peak lumbo-pelvic flexion accelerations [αFLEX[LS-PV]] and electro-myographic trunk pre-activity prior to αFLEX[LS-PV] on 43 subjects performing varied landing tasks (height 45cm; with definite or indefinite predictability of a subsequent instant follow up jump). Subjects were contrasted with respect to their previous landing familiarity ( >1000 vs. <100 landings performed in the past 10 years) and gender. Differences of αFLEX[LS-PV] and muscular pre-activity between contrasted subject groups as between landing tasks were equally statistically tested by three-way mixed ANOVA with Post-hoc tests. Associations between αFLEX[LS-PV] and muscular pre-activity were factor-specifically assessed by Spearman's rank order correlation coefficient (rS). Complementarily, muscular pre-activity was subdivided by landing phases [DROP, IMPACT] and discretely assessed for phase specific associations to αFLEX[LS-PV]. Each muscular activity was moreover pairwise compared between DROP and IMPACT (Mean ±SD, Dependent Samples T-test). RESULTS: αMAX was presented with overall high variability within test-days (CV =36\%). Lowest intra-individual variability and highest reproducibility of αMAX between test-days was shown in flexion of the spine. αFLEX[LS-PV] showed largely consistent sig. higher magnitudes compared to αMAX presented in more cranial spinal joints and other motion planes. αFLEX[LS-PV] moreover gradually increased with escalations in landing heights. Landing unfamiliar subjects presented sig. higher αFLEX[LS-PV] in contrast to landing familiar ones (p=.016). M. Obliquus Int. with M. Transversus Abd. (66 ±32\%MVC) and M. Erector Spinae (47 ±15\%MVC) presented maredly highest activity in contrast to lowest activity of M. Rectus Abd. (10 ±4\%MVC). Landing unfamiliar subjects showed compared to landing familiar ones sig. higher activity of M. Obliquus Ext. (17 ±8\%MVC, 12 ±7\%MVC, p= .044). M. Obliquus Ext. and its co-contraction ratio with M. Erector Spinae moreover exhibited low but sig. positive correlations to αFLEX[LS-PV] (rs=.39, rs=.31). Each trunk muscule distributed larger shares of its activity to DROP, whereas peak activations of most muscles emerged in the proportionally shorter IMPACT phase. Commonly increased muscular pre-activation particularly at IMPACT was found in landings with a contrived follow up jump and in female subjects, whereby αFLEX[LS-PV] was hereof only marginally affected. DISCUSSION: Highest spine segmental angular accelerations in drop landings emerge in sagittal flexion of the lumbar spine. The compensatory stabilisation of the spine appears to be preponderantly provided by a dorso-ventral co-contraction of M. Obliquus Int., M. Transversus Abd. and M. Erector Spinae. Elevated pre-activity of M. Obliquuis Ext. supposably characterises poor landing experience, which might engender increased bending loads to the lumbar spine. A pervasive large variability of spinal angular accelerations measured across all landing types, suggests a multifarious utilisation of diverse mechanisms compensating for spinal impacts in landing performances. A standardised assessment and valid evaluation of landing evoked lumbar bending loads is hereof largley confined. CONCLUSION: Drop landings elicit most strenuous lumbo-pelvic flexion accelerations, which can be appraised as representatives for high energetic bending loads to the spine. Such entail the highest risk to overload the spinal tissue, when landing demands exceed the individual's landing skill. Previous landing experience and training appears to effectively improve muscular spine stabilisation pattern, diminishing spinal bending loads.},
  language  = {en}
}
@phdthesis{Platz2018,
  author    = {Platz, Anna},
  title     = {Novel pre-stack data confinement and selection for magnetotelluric data processing and its application to data of the Eastern Karoo Basin, South Africa},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-415087},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xx, 1131},
  year      = {2018},
  abstract  = {Magnetotellurics (MT) is a geophysical method that is able to image the electrical conductivity structure of the subsurface by recording time series of natural electromagnetic (EM) field variations. During the data processing these time series are divided into small segments and for each segment spectral values are computed which are typically averaged in a statistical manner to obtain MT transfer functions. Unfortunately, the presence of man-made EM noise sources often deteriorates a significant amount of the recorded time series resulting in disturbed transfer functions. Many advanced processing techniques, e.g. robust statistics, pre-stack data selection or remote reference, have been developed to tackle this problem. The first two techniques reduce the amount of outliers and noise in the data whereas the latter approach removes noise by using data from another MT station. However, especially in populated regions the data processing is still quite challenging even with these approaches. In this thesis, I present two novel pre-stack data confinement and selection criteria for the detection of outliers and noise affected data based on (i) a distance measure of each data segment with regard to the entire sample distribution and (ii) the evaluation of the magnetic polarisation direction of all segments. The first criterion is able to remove data points that scatter around the desired MT distribution and furthermore it can, under some circumstances, even reject complete data cluster originating from noise sources. The second criterion eliminates data points caused by a strongly polarised magnetic signal. Both criteria have been successfully applied to many stations with different noise contaminations showing that they can significantly improve the transfer function estimation. The novel criteria were used to evaluate a MT data set from the Eastern Karoo Basin in South Africa. The corresponding field experiment is part of an extensive research programme to collect information of the current e.g. geological setting in this region prior to a potential shale gas exploitation. The aim was to investigate whether a three-dimensional (3D) inversion of the newly measured data fosters a more realistic mapping of physical properties of the target horizon. For this purpose, a comprehensive 3D model was derived by using all available data. In a second step, I analysed parameters of the target horizon, e.g. its conductivity, that are proxies for physical properties such as thermal maturity and porosity.},
  language  = {en}
}
@phdthesis{Behrendt2018,
  author    = {Behrendt, Felix Nicolas},
  title     = {New bio-based polymers},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418316},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vii, 153},
  year      = {2018},
  abstract  = {Redox-responsive polymers, such as poly(disulfide)s, are a versatile class of polymers with potential applications including gene- and drug-carrier systems. Their degradability under reductive conditions allows for a controlled response to the different redox states that are present throughout the body. Poly(disulfide)s are typically synthesized by step growth polymerizations. Step growth polymerizations, however, may suffer from low conversions and therefore low molar masses, limiting potential applications. The purpose of this thesis was therefore to find and investigate new synthetic routes towards the synthesis of amino acid-based poly(disulfide)s. The different routes in this thesis include entropy-driven ring opening polymerizations of novel macrocyclic monomers, derived from cystine derivatives. These monomers were obtained with overall yields of up to 77\% and were analyzed by mass spectrometry as well as by 1D and 2D NMR spectroscopy. The kinetics of the entropy-driven ring-opening metathesis polymerization (ED-ROMP) were thoroughly investigated in dependence of temperature, monomer concentration, and catalyst concentration. The polymerization was optimized to yield poly(disulfide)s with weight average molar masses of up to 80 kDa and conversions of ~80\%, at the thermodynamic equilibrium. Additionally, an alternative metal free polymerization, namely the entropy-driven ring-opening disulfide metathesis polymerization (ED-RODiMP) was established for the polymerization of the macrocyclic monomers. The effect of different solvents, concentrations and catalyst loadings on the polymerization process and its kinetics were studied. Polymers with very high weight average molar masses of up to 177 kDa were obtained. Moreover, various post-polymerization reactions were successfully performed. This work provides the first example of the homopolymerization of endo-cyclic disulfides by ED-ROMP and the first substantial study into the kinetics of the ED-RODiMP process.},
  language  = {en}
}
@phdthesis{Groetzner2018,
  author    = {Gr{\"o}tzner, Bj{\"o}rn},
  title     = {Nervous allies},
  doi       = {10.25932/publishup-47089},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-470894},
  school      = {Universit{\"a}t Potsdam},
  pages     = {537},
  year      = {2018},
  abstract  = {Diese Dissertation untersucht die Entwicklung der diplomatischen Beziehungen zwischen Frankreich, den USA und der Bundesrepublik Deutschland im Zeitraum von 1969-1980. Auf breiter multiarchivarischer Quellengrundlage rekonstruiert sie die interdependente Außenpolitik dieser drei Staaten im Kontext zentraler Themenkomplexe der 1970er Jahre: des Aufstiegs und Verfalls der Entspannungspolitik, des Streits um den Status quo in Europa, die Deutsche Frage und die Zukunft Berlins, der internationalen Wirtschafts- und W{\"a}hrungskrise, der Debatte um Sicherheit und Zukunft des westlichen B{\"u}ndnisses und des NATO-Doppelbeschlusses. Ebenso betrachtet werden eine Reihe von regionalen Ereignissen und Konflikten mit weitreichenden Auswirkungen wie der Jom-Kippur-Krieg, die Portugiesische Revolution oder die sowjetische Invasion Afghanistans. Die Untersuchung folgt der zentralen, theoretisch motivierten Fragestellung, in welchem Maß staatliche Außenpolitik und diplomatische Beziehungen von individuellen Akteuren an der Spitze der Regierungen, ihren Agenden, Sichtweisen und pers{\"o}nlichen Beziehungen zu internationalen Partnern gepr{\"a}gt wurden oder in welchem Maß deren Entscheidungsfindung andererseits durch strukturelle Faktoren geopolitischer, {\"o}konomischer oder politischer Natur definiert und limitiert wurde. Um diese Frage zu beantworten, fokussiert sich die Dissertation auf die Analyse von Regierungswechseln und deren Auswirkungen auf Kontinuit{\"a}t und Wandel der Außenpolitik. Die Narrative umfasst sieben solcher Regierungswechsel: von Bundeskanzler Kurt Georg Kiesinger zu Willy Brandt (1969) und von Brandt zu Helmut Schmidt (1974) in Bonn, von Pr{\"a}sident Charles de Gaulle zu Georges Pompidou (1969) und von Pompidou zu Val{\´e}ry Giscard d'Estaing (1974) in Paris sowie von Lyndon B. Johnson zu Richard M. Nixon (1969), von Nixon zu Gerald R. Ford (1974) und von Ford zu Jimmy Carter (1977) in Washington. Abseits eines Spektrums empirisch fundierter Erkenntnisse {\"u}ber die Geschichte der internationalen Beziehungen der 1970er Jahre belegt diese Arbeit vor allem hochgradig personalisierte und exklusive außenpolitische Entscheidungsstrukturen und eine deutliche Abh{\"a}ngigkeit der Qualit{\"a}t intergouvernementaler Beziehungen von den pers{\"o}nlichen Beziehungen außenpolitischer F{\"u}hrungspers{\"o}nlichkeiten. Zugleich werden jedoch strukturelle Grenzen ihres Handlungsspielraums im internationalen System deutlich, die von Faktoren wie milit{\"a}rischer Sicherheit und geopolitischer Lage, Zugang zu Ressourcen und {\"o}konomischer Leistungsf{\"a}higkeit sowie politischem Druck aus dem In- und Ausland abh{\"a}ngen. Die Dissertation kommt zu dem zentralen Ergebnis, dass Regierungswechsel zwar bisweilen drastische Einschnitte in Inhalt und Stil der ausw{\"a}rtigen Beziehungen nach sich zogen und Bonn, Paris und Washington im Laufe der Dekade mit vielerlei neuen Herausforderungen konfrontiert wurden, dass in der Gesamtschau jedoch pfadabh{\"a}ngige strukturelle Druckszenarien zu h{\"o}herer politischer Kontinuit{\"a}t im internationalen System f{\"u}hrten, als oft mit den f{\"u}r tiefgreifenden historischen Wandel bekannten 1970er Jahren assoziiert wird.},
  language  = {de}
}
@phdthesis{Zimmermann2018,
  author    = {Zimmermann, Marc},
  title     = {Multifunctional patchy silica particles via microcontact printing},
  doi       = {10.25932/publishup-42773},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427731},
  school      = {Universit{\"a}t Potsdam},
  pages     = {IX, 121, xiii},
  year      = {2018},
  abstract  = {This research addressed the question, if it is possible to simplify current microcontact printing systems for the production of anisotropic building blocks or patchy particles, by using common chemicals while still maintaining reproducibility, high precision and tunability of the Janus-balance Chapter 2 introduced the microcontact printing materials as well as their defined electrostatic interactions. In particular polydimethylsiloxane stamps, silica particles and high molecular weight polyethylenimine ink were mainly used in this research. All of these components are commercially available in large quantities and affordable, which gives this approach a huge potential for further up-scaling developments. The benefits of polymeric over molecular inks was described including its flexible influence on the printing pressure. With this alteration of the µCP concept, a new method of solvent assisted particle release mechanism enabled the switch from two-dimensional surface modification to three-dimensional structure printing on colloidal silica particles, without changing printing parameters or starting materials. This effect opened the way to use the internal volume of the achieved patches for incorporation of nano additives, introducing additional physical properties into the patches without alteration of the surface chemistry. The success of this system and its achievable range was further investigated in chapter 3 by giving detailed information about patch geometry parameters including diameter, thickness and yield. For this purpose, silica particles in a size range between 1µm and 5µm were printed with different ink concentrations to change the Janus-balance of these single patched particles. A necessary intermediate step, consisting of air-plasma treatment, for the production of trivalent particles using "sandwich" printing was discovered and comparative studies concerning the patch geometry of single and double patched particles were conducted. Additionally, the usage of structured PDMS stamps during printing was described. These results demonstrate the excellent precision of this approach and opens the pathway for even greater accuracy as further parameters can be finely tuned and investigated, e.g. humidity and temperature during stamp loading. The performance of these synthesized anisotropic colloids was further investigated in chapter 4, starting with behaviour studies in alcoholic and aqueous dispersions. Here, the stability of the applied patches was studied in a broad pH range, discovering a release mechanism by disabling the electrostatic bonding between particle surface and polyelectrolyte ink. Furthermore, the absence of strong attractive forces between divalent particles in water was investigated using XPS measurements. These results lead to the conclusion that the transfer of small PDMS oligomers onto the patch surface is shielding charges, preventing colloidal agglomeration. However, based on this knowledge, further patch modifications for particle self-assembly were introduced including physical approaches using magnetic nano additives, chemical patch functionalization with avidin-biotin or the light responsive cyclodextrin-arylazopyrazoles coupling as well as particle surface modification for the synthesis of highly amphiphilic colloids. The successful coupling, its efficiency, stability and behaviour in different solvents were evaluated to find a suitable coupling system for future assembly experiments. Based on these results the possibility of more sophisticated structures by colloidal self-assembly is given. Certain findings needed further analysis to understand their underlying mechanics, including the relatively broad patch diameter distribution and the decreasing patch thickness for smaller silica particles. Mathematical assumptions for both effects are introduced in chapter 5. First, they demonstrate the connection between the naturally occurring particle size distribution and the broadening of the patch diameter, indicating an even higher precision for this µCP approach. Second, explaining the increase of contact area between particle and ink surface due to higher particle packaging, leading to a decrease in printing pressure for smaller particles. These calculations ultimately lead to the development of a new mechanical microcontact printing approach, using centrifugal forces for high pressure control and excellent parallel alignment of printing substrates. First results with this device and the comparison with previously conducted by-hand experiments conclude this research. It furthermore displays the advantages of such a device for future applications using a mechanical printing approach, especially for accessing even smaller nano particles with great precision and excellent yield. In conclusion, this work demonstrates the successful adjustment of the µCP approach using commercially available and affordable silica particles and polyelectrolytes for high flexibility, reduced costs and higher scale-up value. Furthermore, its was possible to increase the modification potential by introducing three-dimensional patches for additional functionalization volume. While keeping a high colloidal stability, different coupling systems showed the self-assembly capabilities of this toolbox for anisotropic particles.},
  language  = {en}
}
@phdthesis{Hoischen2018,
  author    = {Hoischen, Clemens},
  title     = {Multi-Messenger Astronomy with H.E.S.S: the Starburst Galaxy NGC253 and the Search for Short Time-Scale Transients},
  doi       = {10.25932/publishup-42452},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-424521},
  school      = {Universit{\"a}t Potsdam},
  pages     = {135},
  year      = {2018},
  abstract  = {Gamma-ray astronomy has proven to provide unique insights into cosmic-ray accelerators in the past few decades. By combining information at the highest photon energies with the entire electromagnetic spectrum in multi-wavelength studies, detailed knowledge of non-thermal particle populations in astronomical objects and systems has been gained: Many individual classes of gamma-ray sources could be identified inside our galaxy and outside of it. Different sources were found to exhibit a wide range of temporal evolution, ranging from seconds to stable behaviours over many years of observations. With the dawn of both neutrino- and gravitational wave astronomy, additional messengers have come into play over the last years. This development presents the advent of multi-messenger astronomy: a novel approach not only to search for sources of cosmic rays, but for astronomy in general. In this thesis, both traditional multi-wavelength studies and multi-messenger studies will be presented. They were carried out with the H.E.S.S. experiment, an imaging air Cherenkov telescope array located in the Khomas Highland of Namibia. H.E.S.S. has entered its second phase in 2012 with the addition of a large, fifth telescope. While the initial array was limited to the study of gamma-rays with energies above 100 GeV, the new instrument allows to access gamma-rays with energies down to a few tens of GeV. Strengths of the multi-wavelength approach will be demonstrated at the example of the galaxy NGC253, which is undergoing an episode of enhanced star-formation. The gamma-ray emission will be discussed in light of all the information on this system available from radio, infrared and X-rays. These wavelengths reveal detailed information on the population of supernova remnants, which are suspected cosmic-ray accelerators. A broad-band gamma-ray spectrum is derived from H.E.S.S. and Fermi-LAT data. The improved analysis of H.E.S.S. data provides a measurement which is no longer dominated by systematic uncertainties. The long-term behaviour of cosmic rays in the starburst galaxy NGC253 is finally characterised. In contrast to the long time-scale evolution of a starburst galaxy, multi-messenger studies are especially intriguing when shorter time-scales are being probed. A prime example of a short time-scale transient are Gamma Ray Bursts. The efforts to understand this phenomenon effectively founded the branch of gamma-ray astronomy. The multi-messenger approach allows for the study of illusive phenomena such as Gamma Ray Bursts and other transients using electromagnetic radiation, neutrinos, cosmic rays and gravitational waves contemporaneously. With contemporaneous observations getting more important just recently, the execution of such observation campaigns still presents a big challenge due to the different limitations and strengths of the infrastructures. An alert system for transient phenomena has been developed over the course of this thesis for H.E.S.S. It aims to address many follow-up challenges in order to maximise the science return of the new large telescope, which is able to repoint much faster than the initial four telescopes. The system allows for fully automated observations based on scientific alerts from any wavelength or messenger and allows H.E.S.S. to participate in multi-messenger campaigns. Utilising this new system, many interesting multi-messenger observation campaigns have been performed. Several highlight observations with H.E.S.S. are analysed, presented and discussed in this work. Among them are observations of Gamma Ray Bursts with low latency and low energy threshold, the follow-up of a neutrino candidate in spatial coincidence with a flaring active galactic nucleus and of the merger of two neutron stars, which was revealed by the coincidence of gravitational waves and a Gamma-Ray Burst.},
  language  = {en}
}
@phdthesis{Elin2018,
  author    = {Elin, Kirill},
  title     = {Morphological processing in older adults},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418605},
  school      = {Universit{\"a}t Potsdam},
  pages     = {217},
  year      = {2018},
  abstract  = {Over the last decades mechanisms of recognition of morphologically complex words have been extensively examined in order to determine whether all word forms are stored and retrieved from the mental lexicon as wholes or whether they are decomposed into their morphological constituents such as stems and affixes. Most of the research in this domain focusses on English. Several factors have been argued to affect morphological processing including, for instance, morphological structure of a word (e.g., existence of allomorphic stem alternations) and its linguistic nature (e.g., whether it is a derived word or an inflected word form). It is not clear, however, whether processing accounts based on experimental evidence from English would hold for other languages. Furthermore, there is evidence that processing mechanisms may differ across various populations including children, adult native speakers and language learners. Recent studies claim that processing mechanisms could also differ between older and younger adults (Clahsen \& Reifegerste, 2017; Reifegerste, Meyer, \& Zwitserlood, 2017). The present thesis examined how properties of the morphological structure, types of linguistic operations involved (i.e., the linguistic contrast between inflection and derivation) and characteristics of the particular population such as older adults (e.g., potential effects of ageing as a result of the cognitive decline or greater experience and exposure of older adults) affect initial, supposedly automatic stages of morphological processing in Russian and German. To this end, a series of masked priming experiments was conducted. In experiments on Russian, the processing of derived -ost' nouns (e.g., glupost' 'stupidity') and of inflected forms with and without allomorphic stem alternations in 1P.Sg.Pr. (e.g., igraju - igrat' 'to play' vs. košu - kosit' 'to mow') was examined. The first experiment on German examined and directly compared processing of derived -ung nouns (e.g., Gr{\"u}ndung 'foundation') and inflected -t past participles (e.g., gegr{\"u}ndet 'founded'), whereas the second one investigated the processing of regular and irregular plural forms (-s forms such as Autos 'cars' and -er forms such as Kinder 'children', respectively). The experiments on both languages have shown robust and comparable facilitation effects for derived words and regularly inflected forms without stem changes (-t participles in German, forms of -aj verbs in Russian). Observed morphological priming effects could be clearly distinguished from purely semantic or orthographic relatedness between words. At the same time, we found a contrast between forms with and without allomorphic stem alternations in Russian and regular and irregular forms in German, with significantly more priming for unmarked stems (relative to alternated ones) and significantly more priming for regular (compared) word forms. These findings indicate the relevance of morphological properties of a word for initial stages of processing, contrary to claims made in the literature holding that priming effects are determined by surface form and meaning overlap only. Instead, our findings are more consistent with approaches positing a contrast between combinatorial, rule-based and lexically-stored forms (Clahsen, Sonnenstuhl, \& Blevins, 2003). The doctoral dissertation also addressed the role of ageing and age-related cognitive changes on morphological processing. The results obtained on this research issue are twofold. On the one hand, the data demonstrate effects of ageing on general measures of language performance, i.e., overall longer reaction times and/or higher accuracy rates in older than younger individuals. These findings replicate results from previous studies, which have been linked to the general slowing of processing speed at older age and to the larger vocabularies of older adults. One the other hand, we found that more specific aspects of language processing appear to be largely intact in older adults as revealed by largely similar morphological priming effects for older and younger adults. These latter results indicate that initial stages of morphological processing investigated here by means of the masked priming paradigm persist in older age. One caveat should, however, be noted. Achieving the same performance as a younger individual in a behavioral task may not necessarily mean that the same neural processes are involved. Older people may have to recruit a wider brain network than younger individuals, for example. To address this and related possibilities, future studies should examine older people's neural representations and mechanisms involved in morphological processing.},
  language  = {en}
}
@phdthesis{Ostrowski2018,
  author    = {Ostrowski, Max},
  title     = {Modern constraint answer set solving},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407799},
  school      = {Universit{\"a}t Potsdam},
  pages     = {135},
  year      = {2018},
  abstract  = {Answer Set Programming (ASP) is a declarative problem solving approach, combining a rich yet simple modeling language with high-performance solving capabilities. Although this has already resulted in various applications, certain aspects of such applications are more naturally modeled using variables over finite domains, for accounting for resources, fine timings, coordinates, or functions. Our goal is thus to extend ASP with constraints over integers while preserving its declarative nature. This allows for fast prototyping and elaboration tolerant problem descriptions of resource related applications. The resulting paradigm is called Constraint Answer Set Programming (CASP). We present three different approaches for solving CASP problems. The first one, a lazy, modular approach combines an ASP solver with an external system for handling constraints. This approach has the advantage that two state of the art technologies work hand in hand to solve the problem, each concentrating on its part of the problem. The drawback is that inter-constraint dependencies cannot be communicated back to the ASP solver, impeding its learning algorithm. The second approach translates all constraints to ASP. Using the appropriate encoding techniques, this results in a very fast, monolithic system. Unfortunately, due to the large, explicit representation of constraints and variables, translation techniques are restricted to small and mid-sized domains. The third approach merges the lazy and the translational approach, combining the strength of both while removing their weaknesses. To this end, we enhance the dedicated learning techniques of an ASP solver with the inferences of the translating approach in a lazy way. That is, the important knowledge is only made explicit when needed. By using state of the art techniques from neighboring fields, we provide ways to tackle real world, industrial size problems. By extending CASP to reactive solving, we open up new application areas such as online planning with continuous domains and durations.},
  language  = {en}
}
@phdthesis{Carstensen2018,
  author    = {Carstensen, Janet},
  title     = {Modellentwicklung f{\"u}r eine wirtschaftsorientierte Ausbildung vor dem Hintergrund des Generationenwandels am Beispiel Potsdam},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417542},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XII, 217, L},
  year      = {2018},
  abstract  = {Die deutsche Berufsausbildung hat in den vergangenen Jahren stark an Zuspruch verloren. Dies trifft insbesondere auch auf die duale kaufm{\"a}nnische Berufsausbildung zu. Galt sie vor einigen Jahren noch als ein m{\"o}glicher Ausbildungsweg f{\"u}r leistungsstarke Sch{\"u}ler/-innen, pr{\"a}ferieren diese heute zum großen Teil das Studium. Die wachsende Anzahl an Studienabbrechern belegt jedoch, dass dadurch auch Potenzial verloren geht, weil sich Jugendliche mit dem Studium f{\"u}r einen Ausbildungsweg entscheiden, der f{\"u}r sie nicht geeignet ist. Bisherige Bem{\"u}hungen zur Etablierung alternativer Bildungswege wie zum Beispiel Berufsakademien weisen zwar Erfolge auf, basieren jedoch auf einem Konzept, das sich ausschließlich am Bedarf der Wirtschaft orientiert. Es ist jedoch die {\"U}berzeugung der Autorin, dass neue innovative Bildungswege auch die Bed{\"u}rfnisse und Vorstellungen derjenigen ber{\"u}cksichtigen m{\"u}ssen, f{\"u}r die sie entworfen werden. Denn die Generation der heutigen Jugendlichen zeichnet sich dadurch aus, dass sie ein anderes Wertekonzept als ihre Vorg{\"a}ngergenerationen aufweist. Die Dissertation entwickelt daher ein Modell einer wirtschaftsorientierten Ausbildung, welches sich aus unterschiedlichen motivationstheoretischen Elementen ableitet und zugleich die Werte der Generation der heutigen Jugend-lichen ber{\"u}cksichtigt. Es umfasst sowohl die Anreiz-Beitrags-Theorie nach Barnard als auch die Inhalts-Erwartungstheorie nach Vroom. Zudem liegt ein Hauptaugenmerk dieser Arbeit auf der Anpassung der Zwei-Faktoren-Theorie nach Herzberg auf die heutige Zeit. Empirisch basiert die Dissertation auf einem dreistufigen Untersuchungsdesign. Die erste Stufe umfasst eine quantitative Befragung von insgesamt 459 Abiturienten/-innen und 100 Studierenden. In der zweiten Stufe wurden 10 Studieren-de und 12 Abiturienten/-innen qualitativ befragt. Eine Validierung der Ergebnis-se erfolgte in der dritten Stufe mittels Experteninterviews. Das Ziel der empirischen Untersuchung bestand in der {\"U}berpr{\"u}fung von vier Hypothesen als Basis zur Modellableitung: Hypothese H1 - Flexibilit{\"a}t erh{\"o}ht die Attraktivit{\"a}t einer wirtschaftsorientierten Ausbildung: Der Faktor Flexibilit{\"a}t wurde als ein relevanter Motivator f{\"u}r die Wahl eines Ausbildungsweges identifiziert. Jugendliche wollen sich heutzutage nicht sofort bzw. nicht zu fr{\"u}h festlegen m{\"u}ssen. Hypothese H2 - Auslandsaufenthalte erh{\"o}hen die Attraktivit{\"a}t einer wirtschaftsorientierten Ausbildung: Es wurde best{\"a}tigt, dass Auslandsaufenthalte die Attraktivit{\"a}t einer wirtschaftsorientierten Ausbildung steigert, es besteht jedoch eine Reihe von Barrieren, die Jugendliche (obwohl sie den grunds{\"a}tzlichen Vor-teil sehen) davon abhalten, einen Auslandsaufenthalt f{\"u}r sich selbst in Betracht zu ziehen. Hypothese H3 - Das Aufzeigen einer Karriereperspektive erh{\"o}ht die Attraktivit{\"a}t einer wirtschaftsorientierten Ausbildung: F{\"u}r die Generation der heutigen Jugendlichen steht bez{\"u}glich der Wahl ihres Ausbildungsweges die Aussicht auf eine T{\"a}tigkeit im Vordergrund, die ein gesichertes Einkommen und somit ein gutes Leben erm{\"o}glicht und zudem aus ihrer Sicht eine gewisse Sinnhaftigkeit hat. F{\"u}hrungspositionen, in denen auch h{\"o}here Verantwortung {\"u}bernommen wird, strebt nur eine Minderheit an. Hypothese H4 - Zus{\"a}tzliche monet{\"a}re Anreize erh{\"o}hen die Attraktivit{\"a}t einer wirtschaftsorientierten Ausbildung: Verg{\"u}tungsbestandteile werden grunds{\"a}tzlich nicht abgelehnt (das w{\"a}re auch irrational), haben jedoch auch nicht die Anreizfunktion, die ihr auf Basis der Voruntersuchung im Rahmen dieser Arbeit h{\"a}tte unterstellt werden k{\"o}nnen. F{\"u}r die Entscheidungsfindung bez{\"u}glich eines Ausbildungsweges spielen sie nur eine untergeordnete Rolle. Dennoch tr{\"a}gt die Verg{\"u}tung zur Attraktivit{\"a}t eines Ausbildungsweges bei. Basierend auf den zuvor genannten Ergebnissen wurde das Modell einer wirtschaftsorientieren Ausbildung abgeleitet, das sowohl horizontal als auch vertikal flexibel ist. Horizontale Flexibilit{\"a}t ist dadurch gegeben, dass innerhalb eines Ausbildungsjahres unterschiedliche Unternehmen und Branchen kennengelernt werden (Jahr 1 und Jahr 2). Eine Spezialisierung erfolgt erst in den sp{\"a}teren Ausbildungsjahren. Durch die M{\"o}glichkeit, nach jedem Ausbildungsjahr mit einem Abschluss ins Berufsleben zu wechseln und die Ausbildung gegebenenfalls zu einem sp{\"a}teren Zeitpunkt fortzusetzen, ist auch eine vertikale Flexibilit{\"a}t gegeben. Zudem bietet das Modell Studienabbrechern/-innen die M{\"o}glichkeit, im Ausbildungsjahr 2 bzw. 3 in die Ausbildung einzusteigen. Im Jahr 2 und/oder Jahr 3 sind Auslandsaufenthalte integriert. Diese werden fakultativ an-geboten. Bereits ab dem Jahr 1 besteht die M{\"o}glichkeit, Vorbereitungskurse zu belegen. Der hohen Bedeutung der Karriereperspektive wird im abgeleiteten Modell auf mehreren Ebenen Rechnung getragen. So werden nach jedem Ausbildungsjahr anerkannte Abschl{\"u}sse erreicht. W{\"a}hrend diese in den Jahren 1 und 2 mit IHK-Abschl{\"u}ssen gleichzusetzen sind, beginnen ab Jahr 3 die akademischen Graduierungen (Jahr 3 Bachelor, Jahr 4 Master). Die Verg{\"u}tung wird Bestandteil einer wirtschaftsorientierten Ausbildung, wobei ihre H{\"o}he mit Dauer der Ausbildung zunimmt. Da mit der Einf{\"u}hrung des Modells einer wirtschaftsorientierten Ausbildung die {\"U}berwindung von institutionellen Paradigmen und Schranken verbunden sind, erfolgte im Rahmen des Ausblicks der Arbeit eine weitere Expertenbefragung bez{\"u}glich seiner Umsetzbarkeit. Es setzt eine Beweglichkeit von institutioneller Seite voraus (hierbei insbesondere auch von den Kammern), die von der Mehr-zahl der Experten derzeit skeptisch gesehen wird. Die konzeptionelle Ausgestaltung findet grunds{\"a}tzlichen Zuspruch, wobei in einigen Details, zum Beispiel in der Dauer der Ausbildung, noch Kl{\"a}rungsbedarf besteht. Grunds{\"a}tzlich schließen sich die Experten/-innen der Meinung der Autorin an, dass ein Sinneswandel in der deutschen Ausbildungslandschaft gew{\"u}nscht und gefordert wird. Dies betrifft insbesondere auch den kaufm{\"a}nnischen Bereich. Diese Arbeit liefert mit dem Modell der wirtschaftsorientierten Ausbildung einen wichtigen Beitrag zur Diskussion {\"u}ber neue Ausbildungswege.},
  language  = {de}
}
@phdthesis{Fer2018,
  author    = {Fer, Istem},
  title     = {Modeling past, present and future climate induced vegetation changes in East Africa},
  doi       = {10.25932/publishup-42777},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427777},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxii, 156},
  year      = {2018},
  abstract  = {Ostafrika ist ein nat{\"u}rliches Labor: Durch ein Studium seiner einzigartigen geologischen und biologischen Geschichte lassen sich unsere Theorien und Modelle {\"u}berpr{\"u}fen und verbessern. Ein Studium seiner Gegenwart und seiner Zukunft wiederum hilft uns dabei, die global bedeutende Artenvielfalt und die {\"o}kosystemaren Dienstleistungen Ostafrikas zu sch{\"u}tzen. Eine zentrale Rolle spielt dabei spielt die ostafrikanische Vegetation, deren Dynamiken in dieser Dissertation durch Computersimulationen quantifiziert werden sollen. {\"U}ber Computersimulationen lassen sich fr{\"u}here Rahmenbedingungen reproduzieren, Voraussagen treffen oder Simulationsexperimente durchf{\"u}hren, die durch Feldforschung nicht m{\"o}glich w{\"a}ren. Zuallererst muss jedoch ihre Leistungsf{\"a}higkeit {\"u}berpr{\"u}ft werden. Die von dem Modell anhand der heutigen Inputs gelieferten Ergebnisse stimmten weitgehend mit heutigen Beobachtungen ostafrikanischer Vegetation {\"u}berein. Als n{\"a}chstes wurde die fr{\"u}here Vegetation simuliert, f{\"u}r die fossile Pollen-Daten zum Abgleich vorliegen. {\"U}ber Computermodelle lassen sich Wissensl{\"u}cken zwischen Standorten {\"u}berbr{\"u}cken, bei denen wir {\"u}ber fossile Pollen-Daten verf{\"u}gen, sodass ein vollst{\"a}ndigeres Bild der Vergangenheit entsteht. Zus{\"a}tzlich validiert wurde die Leistungsf{\"a}higkeit des Modells durch die hohe {\"U}bereinstimmung zwischen Modell und Pollen-Daten, wo sie im Raum {\"u}berlappen. Nachdem das Modell getestet und f{\"u}r die Region validiert war, konnte eine der seit langem offenen Fragen {\"u}ber die ostafrikanische Vegetation angegangen werden, n{\"a}mlich wie Ostafrika seines Tropenwaldes verlustig gehen konnte. In den Tropen wird die heutige Vegetation weltweit haupts{\"a}chlich von W{\"a}ldern dominiert, mit Ausnahme der Tropengebiete Ostafrikas, wo W{\"a}lder nur noch stellenweise an der K{\"u}ste und im Hochland vorkommen. Durch eine Reihe von Simulationsexperimenten konnte aufgezeigt werden, unter welchen Bedingungen jene Waldgebiete fr{\"u}her zusammenhingen und schließlich fragmentiert wurden. Die Studie hat erwiesen, wie empfindlich die ostafrikanische Vegetation f{\"u}r die Klimaschwankungen ist, die durch den k{\"u}nftigen Klimawandel zu erwarten sind. Weitere Auswirkungen auf das ostafrikanische Klima ergeben sich aus dem El Ni{\~n}o/Southern Oscillation-Ph{\"a}nomen (ENSO), das aus Temperaturfluktuationen zwischen dem Ozean und der Atmosph{\"a}re herr{\"u}hrt und k{\"u}nftig an Intensit{\"a}t zunehmen d{\"u}rfte. Die derzeitigen Klimamodelle sind allerdings noch nicht gut genug beim Erfassen solcher Ereignismuster. In einer Studie wurde der Einfluss des ENSO-Ph{\"a}nomens auf die ostafrikanische Vegetation quantifiziert und dabei aufgezeigt, wie sehr sich die k{\"u}nftige Vegetation von den heute simulierten Ergebnissen unterscheiden k{\"o}nnte, bei denen der genaue ENSO-Beitrag nicht ber{\"u}cksichtigt werden kann. Bei der Berechnung der k{\"u}nftigen weltweiten CO2-Bilanz und den zu treffenden Entscheidungen stellt dies einen zus{\"a}tzlichen Unsicherheitsfaktor dar.},
  language  = {en}
}
@phdthesis{Pufahl2018,
  author    = {Pufahl, Luise},
  title     = {Modeling and executing batch activities in business processes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-408013},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xix, 163},
  year      = {2018},
  abstract  = {Business process automation improves organizations' efficiency to perform work. Therefore, a business process is first documented as a process model which then serves as blueprint for a number of process instances representing the execution of specific business cases. In existing business process management systems, process instances run independently from each other. However, in practice, instances are also collected in groups at certain process activities for a combined execution to improve the process performance. Currently, this so-called batch processing is executed manually or supported by external software. Only few research proposals exist to explicitly represent and execute batch processing needs in business process models. These works also lack a comprehensive understanding of requirements. This thesis addresses the described issues by providing a basic concept, called batch activity. It allows an explicit representation of batch processing configurations in process models and provides a corresponding execution semantics, thereby easing automation. The batch activity groups different process instances based on their data context and can synchronize their execution over one or as well multiple process activities. The concept is conceived based on a requirements analysis considering existing literature on batch processing from different domains and industry examples. Further, this thesis provides two extensions: First, a flexible batch configuration concept, based on event processing techniques, is introduced to allow run time adaptations of batch configurations. Second, a concept for collecting and batching activity instances of multiple different process models is given. Thereby, the batch configuration is centrally defined, independently of the process models, which is especially beneficial for organizations with large process model collections. This thesis provides a technical evaluation as well as a validation of the presented concepts. A prototypical implementation in an existing open-source BPMS shows that with a few extensions, batch processing is enabled. Further, it demonstrates that the consolidated view of several work items in one user form can improve work efficiency. The validation, in which the batch activity concept is applied to different use cases in a simulated environment, implies cost-savings for business processes when a suitable batch configuration is used. For the validation, an extensible business process simulator was developed. It enables process designers to study the influence of a batch activity in a process with regards to its performance.},
  language  = {en}
}
@phdthesis{Vogel2018,
  author    = {Vogel, Thomas},
  title     = {Model-driven engineering of self-adaptive software},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-409755},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvi, 357},
  year      = {2018},
  abstract  = {The development of self-adaptive software requires the engineering of an adaptation engine that controls the underlying adaptable software by a feedback loop. State-of-the-art approaches prescribe the feedback loop in terms of numbers, how the activities (e.g., monitor, analyze, plan, and execute (MAPE)) and the knowledge are structured to a feedback loop, and the type of knowledge. Moreover, the feedback loop is usually hidden in the implementation or framework and therefore not visible in the architectural design. Additionally, an adaptation engine often employs runtime models that either represent the adaptable software or capture strategic knowledge such as reconfiguration strategies. State-of-the-art approaches do not systematically address the interplay of such runtime models, which would otherwise allow developers to freely design the entire feedback loop. This thesis presents ExecUtable RuntimE MegAmodels (EUREMA), an integrated model-driven engineering (MDE) solution that rigorously uses models for engineering feedback loops. EUREMA provides a domain-specific modeling language to specify and an interpreter to execute feedback loops. The language allows developers to freely design a feedback loop concerning the activities and runtime models (knowledge) as well as the number of feedback loops. It further supports structuring the feedback loops in the adaptation engine that follows a layered architectural style. Thus, EUREMA makes the feedback loops explicit in the design and enables developers to reason about design decisions. To address the interplay of runtime models, we propose the concept of a runtime megamodel, which is a runtime model that contains other runtime models as well as activities (e.g., MAPE) working on the contained models. This concept is the underlying principle of EUREMA. The resulting EUREMA (mega)models are kept alive at runtime and they are directly executed by the EUREMA interpreter to run the feedback loops. Interpretation provides the flexibility to dynamically adapt a feedback loop. In this context, EUREMA supports engineering self-adaptive software in which feedback loops run independently or in a coordinated fashion within the same layer as well as on top of each other in different layers of the adaptation engine. Moreover, we consider preliminary means to evolve self-adaptive software by providing a maintenance interface to the adaptation engine. This thesis discusses in detail EUREMA by applying it to different scenarios such as single, multiple, and stacked feedback loops for self-repairing and self-optimizing the mRUBiS application. Moreover, it investigates the design and expressiveness of EUREMA, reports on experiments with a running system (mRUBiS) and with alternative solutions, and assesses EUREMA with respect to quality attributes such as performance and scalability. The conducted evaluation provides evidence that EUREMA as an integrated and open MDE approach for engineering self-adaptive software seamlessly integrates the development and runtime environments using the same formalism to specify and execute feedback loops, supports the dynamic adaptation of feedback loops in layered architectures, and achieves an efficient execution of feedback loops by leveraging incrementality.},
  language  = {en}
}
@phdthesis{SarnesNitu2018,
  author    = {Sarnes-Nitu, Juliane},
  title     = {Mit der Schuldenbremse zu nachhaltigen Staatsfinanzen?},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-413804},
  school      = {Universit{\"a}t Potsdam},
  pages     = {294},
  year      = {2018},
  abstract  = {The core question of this paper is: Does the debt brake secure fiscal sustainability in Germany? To answer this question, we will first examine the effects of the introduction of the debt brake on the German federal states in the period 2010-16. For this purpose, the observed consolidation performance and the consolidation incentive or pressure experienced by the federal states were evaluated with the help of a scorecard specifically developed for this purpose. Multiple regression analysis was used to analyze how the scorecard factors affect the consolidation performance of the federal states. It found that nearly 90\% of the variation was explained by the independent variables budgetary position, debt burden, revenue growth and pension burden. Thus the debt brake likely played a subordinate role in the 2009-2016 consolidation episode. Subsequently, the data collected in 65 expert interviews was used to analyze the limits of the new fiscal rule, and to determine which potential risks could hinder or prevent the debt brake in the future: municipal debt, FEUs, contingent liabilities in the form of guarantees for financial institutions and pension obligations. The frequently expressed criticism that the debt brake impedes economic growth and public investments is also reviewed and rejected. Finally, we discuss potential future developments regarding the debt brake and the German public administration as well as future consolidation efforts of the L{\"a}nder.},
  language  = {de}
}
@phdthesis{AriasAndres2018,
  author    = {Arias Andr{\´e}s, Mar{\´i}a de Jes{\´u}s},
  title     = {Microbial gene exchange on microplastic particles},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417241},
  school      = {Universit{\"a}t Potsdam},
  pages     = {94},
  year      = {2018},
  abstract  = {Plastic pollution is ubiquitous on the planet since several millions of tons of plastic waste enter aquatic ecosystems each year. Furthermore, the amount of plastic produced is expected to increase exponentially shortly. The heterogeneity of materials, additives and physical characteristics of plastics are typical of these emerging contaminants and affect their environmental fate in marine and freshwaters. Consequently, plastics can be found in the water column, sediments or littoral habitats of all aquatic ecosystems. Most of this plastic debris will fragment as a product of physical, chemical and biological forces, producing particles of small size. These particles (< 5mm) are known as "microplastics" (MP). Given their high surface-to-volume ratio, MP stimulate biofouling and the formation of biofilms in aquatic systems. As a result of their unique structure and composition, the microbial communities in MP biofilms are referred to as the "Plastisphere." While there is increasing data regarding the distinctive composition and structure of the microbial communities that form part of the plastisphere, scarce information exists regarding the activity of microorganisms in MP biofilms. This surface-attached lifestyle is often associated with the increase in horizontal gene transfer (HGT) among bacteria. Therefore, this type of microbial activity represents a relevant function worth to be analyzed in MP biofilms. The horizontal exchange of mobile genetic elements (MGEs) is an essential feature of bacteria. It accounts for the rapid evolution of these prokaryotes and their adaptation to a wide variety of environments. The process of HGT is also crucial for spreading antibiotic resistance and for the evolution of pathogens, as many MGEs are known to contain antibiotic resistance genes (ARGs) and genetic determinants of pathogenicity. In general, the research presented in this Ph.D. thesis focuses on the analysis of HGT and heterotrophic activity in MP biofilms in aquatic ecosystems. The primary objective was to analyze the potential of gene exchange between MP bacterial communities vs. that of the surrounding water, including bacteria from natural aggregates. Moreover, the thesis addressed the potential of MP biofilms for the proliferation of biohazardous bacteria and MGEs from wastewater treatment plants (WWTPs) and associated with antibiotic resistance. Finally, it seeks to prove if the physiological profile of MP biofilms under different limnological conditions is divergent from that of the water communities. Accordingly, the thesis is composed of three independent studies published in peer-reviewed journals. The two laboratory studies were performed using both model and environmental microbial communities. In the field experiment, natural communities from freshwater ecosystems were examined. In Chapter I, the inflow of treated wastewater into a temperate lake was simulated with a concentration gradient of MP particles. The effects of MP on the microbial community structure and the occurrence of integrase 1 (int 1) were followed. The int 1 is a marker associated with mobile genetic elements and known as a proxy for anthropogenic effects on the spread of antimicrobial resistance genes. During the experiment, the abundance of int1 increased in the plastisphere with increasing MP particle concentration, but not in the surrounding water. In addition, the microbial community on MP was more similar to the original wastewater community with increasing microplastic concentrations. Our results show that microplastic particles indeed promote persistence of standard indicators of microbial anthropogenic pollution in natural waters. In Chapter II, the experiments aimed to compare the permissiveness of aquatic bacteria towards model antibiotic resistance plasmid pKJK5, between communities that form biofilms on MP vs. those that are free-living. The frequency of plasmid transfer in bacteria associated with MP was higher when compared to bacteria that are free-living or in natural aggregates. Moreover, comparison increased gene exchange occurred in a broad range of phylogenetically-diverse bacteria. The results indicate a different activity of HGT in MP biofilms, which could affect the ecology of aquatic microbial communities on a global scale and the spread of antibiotic resistance. Finally, in Chapter III, physiological measurements were performed to assess whether microorganisms on MP had a different functional diversity from those in water. General heterotrophic activity such as oxygen consumption was compared in microcosm assays with and without MP, while diversity and richness of heterotrophic activities were calculated by using Biolog® EcoPlates. Three lakes with different nutrient statuses presented differences in MP-associated biomass build up. Functional diversity profiles of MP biofilms in all lakes differed from those of the communities in the surrounding water, but only in the oligo-mesotrophic lake MP biofilms had a higher functional richness compared to the ambient water. The results support that MP surfaces act as new niches for aquatic microorganisms and can affect global carbon dynamics of pelagic environments. Overall, the experimental works presented in Chapters I and II support a scenario where MP pollution affects HGT dynamics among aquatic bacteria. Among the consequences of this alteration is an increase in the mobilization and transfer efficiency of ARGs. Moreover, it supposes that changes in HGT can affect the evolution of bacteria and the processing of organic matter, leading to different catabolic profiles such as demonstrated in Chapter III. The results are discussed in the context of the fate and magnitude of plastic pollution and the importance of HGT for bacterial evolution and the microbial loop, i.e., at the base of aquatic food webs. The thesis supports a relevant role of MP biofilm communities for the changes observed in the aquatic microbiome as a product of intense human intervention.},
  language  = {en}
}
@phdthesis{Kettner2018,
  author    = {Kettner, Marie Therese},
  title     = {Microbial colonization of microplastic particles in aquatic systems},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418854},
  school      = {Universit{\"a}t Potsdam},
  pages     = {139},
  year      = {2018},
  abstract  = {The continuously increasing pollution of aquatic environments with microplastics (plastic particles < 5 mm) is a global problem with potential implications for organisms of all trophic levels. For microorganisms, trillions of these floating microplastics particles represent a huge surface area for colonization. Due to the very low biodegradability, microplastics remain years to centuries in the environment and can be transported over thousands of kilometers together with the attached organisms. Since also pathogenic, invasive, or otherwise harmful species could be spread this way, it is essential to study microplastics-associated communities. For this doctoral thesis, eukaryotic communities were analyzed for the first time on microplastics in brackish environments and compared to communities in the surrounding water and on the natural substrate wood. With Illumina MiSeq high-throughput sequencing, more than 500 different eukaryotic taxa were detected on the microplastics samples. Among them were various green algae, dinoflagellates, ciliates, fungi, fungal-like protists and small metazoans such as nematodes and rotifers. The most abundant organisms was a dinoflagellate of the genus Pfiesteria, which could include fish pathogenic and bloom forming toxigenic species. Network analyses revealed that there were numerous interaction possibilities among prokaryotes and eukaryotes in microplastics biofilms. Eukaryotic community compositions on microplastics differed significantly from those on wood and in water, and compositions were additionally distinct among the sampling locations. Furthermore, the biodiversity was clearly lower on microplastics in comparison to the diversity on wood or in the surrounding water. In another experiment, a situation was simulated in which treated wastewater containing microplastics was introduced into a freshwater lake. With increasing microplastics concentrations, the resulting bacterial communities became more similar to those from the treated wastewater. Moreover, the abundance of integrase I increased together with rising concentrations of microplastics. Integrase I is often used as a marker for anthropogenic environmental pollution and is further linked to genes conferring, e.g., antibiotic resistance. This dissertation gives detailed insights into the complexity of prokaryotic and eukaryotic communities on microplastics in brackish and freshwater systems. Even though microplastics provide novel microhabitats for various microbes, they might also transport toxigenic, pathogenic, antibiotic-resistant or parasitic organisms; meaning their colonization can pose potential threats to humans and the environment. Finally, this thesis explains the urgent need for more research as well as for strategies to minimize the global microplastic pollution.},
  language  = {en}
}
@phdthesis{Ion2018,
  author    = {Ion, Alexandra},
  title     = {Metamaterial devices},
  doi       = {10.25932/publishup-42986},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-429861},
  school      = {Universit{\"a}t Potsdam},
  pages     = {x, 173},
  year      = {2018},
  abstract  = {Digital fabrication machines such as 3D printers excel at producing arbitrary shapes, such as for decorative objects. In recent years, researchers started to engineer not only the outer shape of objects, but also their internal microstructure. Such objects, typically based on 3D cell grids, are known as metamaterials. Metamaterials have been used to create materials that, e.g., change their volume, or have variable compliance. While metamaterials were initially understood as materials, we propose to think of them as devices. We argue that thinking of metamaterials as devices enables us to create internal structures that offer functionalities to implement an input-process-output model without electronics, but purely within the material's internal structure. In this thesis, we investigate three aspects of such metamaterial devices that implement parts of the input-process-output model: (1) materials that process analog inputs by implementing mechanisms based on their microstructure, (2) that process digital signals by embedding mechanical computation into the object's microstructure, and (3) interactive metamaterial objects that output to the user by changing their outside to interact with their environment. The input to our metamaterial devices is provided directly by the users interacting with the device by means of physically pushing the metamaterial, e.g., turning a handle, pushing a button, etc. The design of such intricate microstructures, which enable the functionality of metamaterial devices, is not obvious. The complexity of the design arises from the fact that not only a suitable cell geometry is necessary, but that additionally cells need to play together in a well-defined way. To support users in creating such microstructures, we research and implement interactive design tools. These tools allow experts to freely edit their materials, while supporting novice users by auto-generating cells assemblies from high-level input. Our tools implement easy-to-use interactions like brushing, interactively simulate the cell structures' deformation directly in the editor, and export the geometry as a 3D-printable file. Our goal is to foster more research and innovation on metamaterial devices by allowing the broader public to contribute.},
  language  = {en}
}
@phdthesis{anHaack2018,
  author    = {an Haack, Jan},
  title     = {Market and affect in evangelical mission},
  doi       = {10.25932/publishup-42469},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-424694},
  school      = {Universit{\"a}t Potsdam},
  pages     = {viii, 240},
  year      = {2018},
  abstract  = {This text is a contribution to the research on the worldwide success of evangelical Christianity and offers a new perspective on the relationship between late modern capitalism and evangelicalism. For this purpose, the utilization of affect and emotion in evangelicalism towards the mobilization of its members will be examined in order to find out what similarities to their employment in late modern capitalism can be found. Different examples from within the evangelical spectrum will be analyzed as affective economies in order to elaborate how affective mobilization is crucial for evangelicalism's worldwide success. Pivotal point of this text is the exploration of how evangelicalism is able to activate the voluntary commitment of its members, financiers, and missionaries. Gathered here are examples where both spheres—evangelicalism and late modern capitalism—overlap and reciprocate, followed by a theoretical exploration of how the findings presented support a view of evangelicalism as an inner-worldly narcissism that contributes to an assumed re-enchantment of the world.},
  language  = {en}
}
@phdthesis{Hintsche2018,
  author    = {Hintsche, Marius},
  title     = {Locomotion of a bacterium with a polar bundle of flagella},
  doi       = {10.25932/publishup-42697},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-426972},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xi, 108},
  year      = {2018},
  abstract  = {Movement and navigation are essential for many organisms during some parts of their lives. This is also true for bacteria, which can move along surfaces and swim though liquid environments. They are able to sense their environment, and move towards environmental cues in a directed fashion. These abilities enable microbial lifecyles in biofilms, improved food uptake, host infection, and many more. In this thesis we study aspects of the swimming movement - or motility - of the soil bacterium (P. putida). Like most bacteria, P. putida swims by rotating its helical flagella, but their arrangement differs from the main model organism in bacterial motility research: (E. coli). P. putida is known for its intriguing motility strategy, where fast and slow episodes can occur after each other. Up until now, it was not known how these two speeds can be produced, and what advantages they might confer to this bacterium. Normally the flagella, the main component of thrust generation in bacteria, are not observable by ordinary light microscopy. In order to elucidate this behavior, we therefore used a fluorescent staining technique on a mutant strain of this species to specifically label the flagella, while leaving the cell body only faintly stained. This allowed us to image the flagella of the swimming bacteria with high spacial and temporal resolution with a customized high speed fluorescence microscopy setup. Our observations show that P. putida can swim in three different modes. First, It can swim with the flagella pushing the cell body, which is the main mode of swimming motility previously known from other bacteria. Second, it can swim with the flagella pulling the cell body, which was thought not to be possible in situations with multiple flagella. Lastly, it can wrap its flagellar bundle around the cell body, which results in a speed wich is slower by a factor of two. In this mode, the flagella are in a different physical conformation with a larger radius so the cell body can fit inside. These three swimming modes explain the previous observation of two speeds, as well as the non strict alternation of the different speeds. Because most bacterial swimming in nature does not occur in smoothly walled glass enclosures under a microscope, we used an artificial, microfluidic, structured system of obstacles to study the motion of our model organism in a structured environment. Bacteria were observed in microchannels with cylindrical obstacles of different sizes and with different distances with video microscopy and cell tracking. We analyzed turning angles, run times, and run length, which we compared to a minimal model for movement in structured geometries. Our findings show that hydrodynamic interactions with the walls lead to a guiding of the bacteria along obstacles. When comparing the observed behavior with the statics of a particle that is deflected with every obstacle contact, we find that cells run for longer distances than that model. Navigation in chemical gradients is one of the main applications of motility in bacteria. We studied the swimming response of P. putida cells to chemical stimuli (chemotaxis) of the common food preservative sodium benzoate. Using a microfluidic gradient generation device, we created gradients of varying strength, and observed the motion of cells with a video microscope and subsequent cell tracking. Analysis of different motility parameters like run lengths and times, shows that P. putida employs the classical chemotaxis strategy of E. coli: runs up the gradient are biased to be longer than those down the gradient. Using the two different run speeds we observed due to the different swimming modes, we classify runs into `fast' and `slow' modes with a Gaussian mixture model (GMM). We find no evidence that P. putida's uses its swimming modes to perform chemotaxis. In most studies of bacterial motility, cell tracking is used to gather trajectories of individual swimming cells. These trajectories then have to be decomposed into run sections and tumble sections. Several algorithms have been developed to this end, but most require manual tuning of a number of parameters, or extensive measurements with chemotaxis mutant strains. Together with our collaborators, we developed a novel motility analysis scheme, based on generalized Kramers-Moyal-coefficients. From the underlying stochastic model, many parameters like run length etc., can be inferred by an optimization procedure without the need for explicit run and tumble classification. The method can, however, be extended to a fully fledged tumble classifier. Using this method, we analyze E. coli chemotaxis measurements in an aspartate analog, and find evidence for a chemotactic bias in the tumble angles.},
  language  = {en}
}
@phdthesis{Feldmann2018,
  author    = {Feldmann, David},
  title     = {Light-driven diffusioosmosis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417184},
  school      = {Universit{\"a}t Potsdam},
  pages     = {viii, 150},
  year      = {2018},
  abstract  = {The emergence of microfluidics created the need for precise and remote control of micron-sized objects. I demonstrate how light-sensitive motion can be induced at the micrometer scale by a simple addition of a photosensitive surfactant, which makes it possible to trigger hydrophobicity with light. With point-like laser irradiation, radial inward and outward hydrodynamic surface flows are remotely switched on and off. In this way, ensembles of microparticles can be moved toward or away from the irradiation center. Particle motion is analyzed according to varying parameters, such as surfactant and salt concentration, illumination condition, surface hydrophobicity, and surface structure. The physical origin of this process is the so-called light-driven diffusioosmosis (LDDO), a phenomenon that was discovered in the framework of this thesis and is described experimentally and theoretically in this work. To give a brief explanation, a focused light irradiation induces a local photoisomerization that creates a concentration gradient at the solid-liquid interface. To compensate for the change in osmotic pressure near the surface, a hydrodynamic flow along the surface is generated. Surface-surfactant interaction largely governs LDDO. It is shown that surfactant adsorption depends on the isomerization state of the surfactant. Photoisomerization, therefore, triggers a surfactant attachment or detachment from the surface. This change is considered to be one of the reasons for the formation of LDDO flow. These flows are introduced not only by a focused laser source but also by global irradiation. Porous particles show reversible repulsive and attractive interactions when dispersed in the solution of photosensitive surfactant. Repulsion and attraction is controlled by the irradiation wavelength. Illumination with red light leads to formation of aggregates, while illumination with blue light leads to the formation of a well-separated grid with equal interparticle distances, between 2µm and 80µm, depending on the particle surface density. These long-range interactions are considered to be a result of an increase or decrease of surfactant concentration around each particle, depending on the irradiation wavelength. Surfactant molecules adsorb inside the pores of the particles. A light-induced photoisomerization changes adsorption to the pores and drives surfactant molecules to the outside. The concentration gradients generate symmetric flows around each single particle resulting in local LDDO. With a break of the symmetry (i.e., by closing one side of the particle with a metal cap), one can achieve active self-propelled particle motion.},
  language  = {en}
}
@phdthesis{Schukraft2018,
  author    = {Schukraft, Stefan},
  title     = {Legislativer Konflikt in den deutschen L{\"a}ndern},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-450-0},
  doi       = {10.25932/publishup-42216},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-422162},
  school      = {Universit{\"a}t Potsdam},
  pages     = {563},
  year      = {2018},
  abstract  = {Gesetzgebungsmehrheiten in parlamentarischen Systemen mit ihrem Dualismus aus Regierungslager und Oppositionsparteien bilden sich nicht frei. Vielmehr findet ihre Koordination in einem Spannungsfeld aus den programmatischen Positionen der Akteure und ihrem opportunistischen Wettbewerb untereinander statt. Diese Problematik bricht die Arbeit auf drei konkrete Fragestellungen herunter, im Rahmen derer sie die Konfliktmuster zwischen Akteuren bei der legislativen Mehrheitskoordination unter Mehrheitsregierungen in den deutschen Landesparlamenten untersucht: 1) Inwieweit h{\"a}ngt es von programmatischen Positionen oder vom opportunistischen Wettbewerb des Neuen Dualismus zwischen Regierungslager und Oppositionsparteien ab, ob Oppositionsparteien und Regierungslager bei der Bildung von Gesetzgebungsmehrheiten kooperieren oder konfligieren? 2) Inwieweit kommt es vor dem Hintergrund unterschiedlicher programmatischer Positionen und opportunistischer {\"U}berlegungen zu Konflikt statt Kooperation zwischen Koalitionsakteuren bei der Bildung gemeinsamer Gesetzgebungsmehrheiten? Letztere Fragestellung wird sodann auch in den Kontext des bundesrepublikanischen Kooperativf{\"o}deralismus eingebettet: 3) Inwieweit geht die Bildung von Gesetzgebungsmehrheiten bei der Ausf{\"u}hrung von Bundesgesetzen in Mischkoalitionen (bestehend aus Parteien, die sich auf Bundesebene in konkurrierenden Lagern gegen{\"u}berstehen) mit mehr Konflikt einher als in ebenen{\"u}bergreifend kongruenten Regierungskoalitionen? Theoretisch wird ein rationalistisches Modell der grundlegenden Handlungsanreize bei der Bildung von Gesetzgebungsmehrheiten in den deutschen Landesparlamenten erarbeitet. Auf dieser Basis besch{\"a}ftigt sich die Arbeit damit, wie die Akteure strategisch programmatische und opportunistische Anreize zu Konflikt und Kooperation abw{\"a}gen. Die Arbeit leitet dann konkrete Determinanten ab, die vorwiegend - aber nicht nur - mittels quantitativer Methoden getestet werden. Die Arbeit st{\"u}tzt sich dabei auf eine gr{\"o}ßtenteils neu zusammengestellte Gesetzgebungsdatenbank aus 3.359 Gesetzgebungsvorg{\"a}ngen aus 23 Legislaturperioden zwischen 1990 und 2013 in den L{\"a}ndern Hamburg, Hessen, Mecklenburg-Vorpommern, Nordrhein-Westfalen und Sachsen-Anhalt. Die Analyse der Konfliktmuster zwischen Oppositionsparteien und Regierungslager zeigt, dass programmatische Distanz einer Oppositionspartei zum Regierungslager f{\"u}r Oppositionsverhalten eine Rolle spielt; dies gilt jedoch auch f{\"u}r opportunistische Aspekte (so l{\"a}sst sich beispielsweise ein kompetitiveres Oppositionsverhalten beobachten, wenn nach der letzten Wahl ein vollst{\"a}ndiger Regierungswechsel erfolgte). Oppositionsverhalten erscheint dabei recht kleinteilig ausgepr{\"a}gt. Neben Unterschieden zwischen Legislaturperioden treten solche auch innerhalb von Legislaturperioden zwischen Akteuren sowie zwischen Gesetzentw{\"u}rfen auf. Die Analyse generellen Koalitionskonflikts weist darauf hin, dass ein nicht unerheblicher Teil von Koalitionskonflikt strukturell bedingt ist. Handelt es sich bei einer gebildeten Regierungskoalition um die Wunschkoalition der beteiligten Parteien, so ist dies Koalitionskonflikt abtr{\"a}glich. Selbiges gilt f{\"u}r eine gr{\"o}ßere Mehrheitsmarge des Regierungslagers. Dar{\"u}ber hinaus ergeben sich Hinweise, dass die Ausf{\"u}hrung von Bundesgesetzen unter Mischkoalitionen bei bundespolitischer Abgrenzung der Koalitionspartner mit mehr Koalitionskonflikt einhergeht als eine Ausf{\"u}hrung unter kongruenten Koalitionen. Der Beitrag der Arbeit ist polymorph angelegt. Sie hilft zun{\"a}chst, die Strategien von Akteuren im Gesetzgebungsprozess besser zu verstehen. Als normativer Beitrag tritt auf einer zweiten Ebene die bessere Erforschung etwaiger nachteiliger Effekte des Neuen Dualismus unter Mehrheitsregierungen hinzu. Gleichzeitig soll die Arbeit drittens in der Zusammenschau helfen, die Mechanik der parlamentarischen Systeme in den L{\"a}ndern selbst zu erhellen und besser normativ bewerten zu k{\"o}nnen. Hintergrund sind hier die jahrzehntealten Debatten um das beste Regierungssystem und -format der deutschen L{\"a}nder als subnationale Entit{\"a}ten. Die dritte Fragestellung dieser Arbeit konnte diese Debatte zudem mit einem neuen Aspekt bereichern. Wissen dar{\"u}ber, inwieweit die Ausf{\"u}hrung von Bundesgesetzen in den L{\"a}ndern je nach ebenen{\"u}bergreifendem Koalitionsmuster in unterschiedlichem Ausmaß mit einem ‚coalition governance'-Problem verbunden ist, f{\"u}gt der Forschung zum f{\"o}deralen Entscheiden in der Bundesrepublik eine neue und beachtenswerte Facette hinzu. Denn dabei handelt es sich um eine f{\"o}deral bedingte mechanische Beeintr{\"a}chtigung der Mehrheitskoordination in den Landesparlamenten selbst, die die potenziell gegebene f{\"o}derale Flexibilit{\"a}t bei der Ausf{\"u}hrung von Bundesgesetzen hemmt. Dies ebnet den Weg zu neuen Debatten dar{\"u}ber, wie in den deutschen L{\"a}ndern mehr legislative Abstimmungsflexibilit{\"a}t erm{\"o}glicht werden kann als unter den bisher {\"u}blichen Mehrheits-Koalitionsregierungen.},
  language  = {de}
}
@phdthesis{Oeztuerk2018,
  author    = {{\"O}zt{\"u}rk, Ugur},
  title     = {Learning more to predict landslides},
  doi       = {10.25932/publishup-42643},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-426439},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxi, 104},
  year      = {2018},
  abstract  = {Landslides are frequent natural hazards in rugged terrain, when the resisting frictional force of the surface of rupture yields to the gravitational force. These forces are functions of geological and morphological factors, such as angle of internal friction, local slope gradient or curvature, which remain static over hundreds of years; whereas more dynamic triggering events, such as rainfall and earthquakes, compromise the force balance by temporarily reducing resisting forces or adding transient loads. This thesis investigates landslide distribution and orientation due to landslide triggers (e.g. rainfall) at different scales (6-4∙10^5 km^2) and aims to link rainfall movement with the landslide distribution. It additionally explores the local impacts of the extreme rainstorms on landsliding and the role of precursory stability conditions that could be induced by an earlier trigger, such as an earthquake. Extreme rainfall is a common landslide trigger. Although several studies assessed rainfall intensity and duration to study the distribution of thus triggered landslides, only a few case studies quantified spatial rainfall patterns (i.e. orographic effect). Quantifying the regional trajectories of extreme rainfall could aid predicting landslide prone regions in Japan. To this end, I combined a non-linear correlation metric, namely event synchronization, and radial statistics to assess the general pattern of extreme rainfall tracks over distances of hundreds of kilometers using satellite based rainfall estimates. Results showed that, although the increase in rainfall intensity and duration positively correlates with landslide occurrence, the trajectories of typhoons and frontal storms were insufficient to explain landslide distribution in Japan. Extreme rainfall trajectories inclined northwestwards and were concentrated along some certain locations, such as coastlines of southern Japan, which was unnoticed in the landslide distribution of about 5000 rainfall-triggered landslides. These landslides seemed to respond to the mean annual rainfall rates. Above mentioned findings suggest further investigation on a more local scale to better understand the mechanistic response of landscape to extreme rainfall in terms of landslides. On May 2016 intense rainfall struck southern Germany triggering high waters and landslides. The highest damage was reported at the Braunsbach, which is located on the tributary-mouth fan formed by the Orlacher Bach. Orlacher Bach is a ~3 km long creek that drains a catchment of about ~6 km^2. I visited this catchment in June 2016 and mapped 48 landslides along the creek. Such high landslide activity was not reported in the nearby catchments within ~3300 km^2, despite similar rainfall intensity and duration based on weather radar estimates. My hypothesis was that several landslides were triggered by rainfall-triggered flash floods that undercut hillslope toes along the Orlacher Bach. I found that morphometric features such as slope and curvature play an important role in landslide distribution on this micro scale study site (<10 km^2). In addition, the high number of landslides along the Orlacher Bach could also be boosted by accumulated damages on hillslopes due karst weathering over longer time scales. Precursory damages on hillslopes could also be induced by past triggering events that effect landscape evolution, but this interaction is hard to assess independently from the latest trigger. For example, an earthquake might influence the evolution of a landscape decades long, besides its direct impacts, such as landslides that follow the earthquake. Here I studied the consequences of the 2016 Kumamoto Earthquake (MW 7.1) that triggered some 1500 landslides in an area of ~4000 km^2 in central Kyushu, Japan. Topography, i.e. local slope and curvature, both amplified and attenuated seismic waves, thus controlling the failure mechanism of those landslides (e.g. progressive). I found that topography fails in explaining the distribution and the preferred orientation of the landslides after the earthquake; instead the landslides were concentrated around the northeast of the rupture area and faced mostly normal to the rupture plane. This preferred location of the landslides was dominated mainly by the directivity effect of the strike-slip earthquake, which is the propagation of wave energy along the fault in the rupture direction; whereas amplitude variations of the seismic radiation altered the preferred orientation. I suspect that the earthquake directivity and the asymmetry of seismic radiation damaged hillslopes at those preferred locations increasing landslide susceptibility. Hence a future weak triggering event, e.g. scattered rainfall, could further trigger landslides at those damaged hillslopes.},
  language  = {en}
}
@phdthesis{Ott2018,
  author    = {Ott, Florian},
  title     = {Late Glacial and Holocene climate and environmental evolution in the southern Baltic lowlands derived from varved lake sediments},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414805},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xix, 241},
  year      = {2018},
  abstract  = {Holocene climate variability is generally characterized by low frequency changes than compared to the last glaciations including the Lateglacial. However, there is vast evidence for decadal to centennial scale oscillations and millennial scale climate trends, which are within and beyond a human lifetime perception, respectively. Within the Baltic realm, a transitional zone between oceanic and continental climate influence, the impact of Holocene and Lateglacial climate and environmental change is currently partly understood. This is mainly attributed to the scarcity of well-dated and high-resolution sediment records and to the lacking continuity of already investigated archives. The aim of this doctoral thesis is to reconstruct Holocene and Late Glacial climate variability on local to (over)regional scales based on varved (annually laminated) sediments from Lake Czechowskie down to annual resolution. This project was carried out within the Virtual Institute for Integrated Climate and Landscape Evolution Analyses (ICLEA) and funded by the Helmholtz Association and the Helmholtz Climate Initiative REKLIM (Regional Climate Change). ICLEA intended to gain a better understanding of climate variability and landscape evolution processes in the Northern Central European lowlands since the last deglaciation. REKLIM Topic 8 "Abrupt climate change derived from proxy data" aims at identifying spatiotemporal patterns of climate variability between e.g. higher and lower latitudes. The main aim of this thesis was (i) to establish a robust chronology based on a multiple dating approach for Lake Czechowskie covering the Late Glacial and Holocene and for the Trzechowskie palaeolake for the Lateglacial, respectively, (ii) to reconstruct past climatic and environmental conditions on centennial to multi-millennial time scales and (iii) to distinguish between local to regional different sediments responses to climate change. Addressing the first aim, the Lake Czechowskie chronology has been established by a multiple dating approach comprising information from varve counting, tephrochronology, AMS 14C dating of terrestrial plant remains, biostratigraphy and 137Cs activity concentration measurements. Those independent age constraints covering the Lateglacial and the entire Holocene and have been further implemented in a Bayesian age model by using OxCal v.4.2. Thus, even within non-varved sediment intervals, robust chronological information has been used for absolute age determination. The identification of five cryptotephras, of which three are used as unambiguous isochrones, is furthermore a significant improvement of the Czechowskie chronology and currently unique for the Holocene within Poland. The first findings of coexisting early Holocene H{\"a}sseldalen and Askja-S cryptotephras within a varved sequence even allowed differential dating between both volcanic ashes and stimulated the discussion of revising the absolute ages of the Askja-S tephra. The Trzechowskie palaeolake chronology has been established by a multiple dating approach comprising varve counting, tephrochronology, AMS 14C dating of terrestrial plant remains and biostratigraphy, covers the Lateglacial period (Aller{\o}d and Younger Dryas) and has been implemented in OxCal v.4.2. Those age constraints allowed regional correlation to other high-resolution climate archives and identifying leads and lags of proxy responses at the onset of the Younger Dryas. The second aim has been accomplished by detailed micro-facies and geochemical analyses of the Czechowskie sediments for the entire Holocene. Thus, especially micro-facies changes had been linked to enhanced productivity at Lake Czechowskie. Most prominent changes have been recorded at 7.3, 6.5, 4.3 and 2.8 varve kyrs BP and are linked to a stepwise increasing influence of Atlantic air masses. Especially, the mid-Holocene change, which had been widely reported from palaeohydrological records in low latitudes, has been identified and linked to large scale reorganization of atmospheric circulation patterns. Thus, especially long-term changes of climatic and environmental boundary conditions are widely recorded by the Czechowskie sediments. The pronounced response to (multi)millennial scale changes is further corroborated by the lack of clear sediment responses to early Holocene centennial scale climate oscillations (e.g. the Preboreal Oscillation). However, decadal scale changes at Lake Czechowskie during the most recent period (last 140 years) have been investigated in a lake comparison study. To fulfill the third aim of the doctoral thesis, three lakes in close vicinity to each other have been investigated in order to better distinguish how local, site-specific parameters, may superimpose regional climate driven changes. All lakes haven been unambiguously linked by the Askja AD1875 cryptotephra and independent varve chronologies. As a result, climate warming has only been recorded by sedimentation changes at the smallest and best sheltered lake (Głęboczek), whereas the largest lake (Czechowskie) and the shallowest lake (Jelonek) showed attenuated and less clear sediment responses, respectively. The different responses have been linked to morphological lake characteristics (lake size and depth, catchment area). This study highlights the potential of high-resolution lake comparison for robust proxy based climate reconstructions. In summary, the doctoral thesis presents a high-resolution sediment record with an underlying age model, which is prerequisite for unprecedented age control down to annual resolution. Sediment proxy based climate reconstructions demonstrate the importance of the Czechowskie sediments for better understanding climate variability in the southern Baltic realm. Case studies showed the clear response on millennial time scale, while decadal scale fluctuations are either less well expressed or superimposed by local, site-specific parameters. The identification of volcanic ash layers is not only used for unambiguous isochrones, those are key tie lines for local to supra regional archive synchronization and establish the Lake Czechowskie as a key climate archive.},
  language  = {en}
}
@phdthesis{Eugster2018,
  author    = {Eugster, Patricia},
  title     = {Landscape evolution in the western Indian Himalaya since the Miocene},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420329},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XXI, 208},
  year      = {2018},
  abstract  = {The Himalayan arc stretches >2500 km from east to west at the southern edge of the Tibetan Plateau, representing one of the most important Cenozoic continent-continent collisional orogens. Internal deformation processes and climatic factors, which drive weathering, denudation, and transport, influence the growth and erosion of the orogen. During glacial times wet-based glaciers sculpted the mountain range and left overdeepend and U-shaped valleys, which were backfilled during interglacial times with paraglacial sediments over several cycles. These sediments partially still remain within the valleys because of insufficient evacuation capabilities into the foreland. Climatic processes overlay long-term tectonic processes responsible for uplift and exhumation caused by convergence. Possible processes accommodating convergence within the orogenic wedge along the main Himalayan faults, which divide the range into four major lithologic units, are debated. In this context, the identification of processes shaping the Earth's surface on short- and on long-term are crucial to understand the growth of the orogen and implications for landscape development in various sectors along the arc. This thesis focuses on both surface and tectonic processes that shape the landscape in the western Indian Himalaya since late Miocene. In my first study, I dated well-preserved glacially polished bedrock on high-elevated ridges and valley walls in the upper of the Chandra Valley the by means of 10Be terrestrial cosmogenic radionuclides (TCN). I used these ages and mapped glacial features to reconstruct the extent and timing of Pleistocene glaciation at the southern front of the Himalaya. I was able to reconstruct an extensive valley glacier of ~200 km length and >1000 m thickness. Deglaciation of the Chandra Valley glacier started subsequently to insolation increase on the Northern Hemisphere and thus responded to temperature increase. I showed that the timing this deglaciation onset was coeval with retreat of further midlatitude glaciers on the Northern and Southern Hemispheres. These comparisons also showed that the post-LGM deglaciation very rapid, occurred within a few thousand years, and was nearly finished prior to the B{\o}lling/Aller{\o}d interstadial. A second study (co-authorship) investigates how glacial advances and retreats in high mountain environments impact the landscape. By 10Be TCN dating and geomorphic mapping, we obtained maximal length and height of the Siachen Glacier within the Nubra Valley. Today the Shyok and Nubra confluence is backfilled with sedimentary deposits, which are attributed to the valley blocking of the Siachen Glacier 900 m above the present day river level. A glacial dam of the Siachen Glacier blocked the Shyok River and lead to the evolution of a more than 20 km long lake. Fluvial and lacustrine deposits in the valley document alternating draining and filling cycles of the lake dammed by the Siachen Glacier. In this study, we can show that glacial incision was outpacing fluvial incision. In the third study, which spans the million-year timescale, I focus on exhumation and erosion within the Chandra and Beas valleys. In this study the position and discussed possible reasons of rapidly exhuming rocks, several 100-km away from one of the main Himalayan faults (MFT) using Apatite Fission Track (AFT) thermochronometry. The newly gained AFT ages indicate rapid exhumation and confirm earlier studies in the Chandra Valley. I assume that the rapid exhumation is most likely related to uplift over subsurface structures. I tested this hypothesis by combining further low-temperature thermochronometers from areas east and west of my study area. By comparing two transects, each parallel to the Beas/Chandra Valley transect, I demonstrate similarities in the exhumation pattern to transects across the Sutlej region, and strong dissimilarities in the transect crossing the Dhauladar Range. I conclude that the belt of rapid exhumation terminates at the western end of the Kullu-Rampur window. Therewith, I corroborate earlier studies suggesting changes in exhumation behavior in the western Himalaya. Furthermore, I discussed several causes responsible for the pronounced change in exhumation patterns along strike: 1) the role of inherited pre-collisional features such as the Proterozoic sedimentary cover of the Indian basement, former ridges and geological structures, and 2) the variability of convergence rates along the Himalayan arc due to an increased oblique component towards the syntaxis. The combination of field observations (geological and geomorphological mapping) and methods to constrain short- and long-term processes (10Be, AFT) help to understand the role of the individual contributors to exhumation and erosion in the western Indian Himalaya. With the results of this thesis, I emphasize the importance of glacial and tectonic processes in shaping the landscape by driving exhumation and erosion in the studied areas.},
  language  = {en}
}
@phdthesis{HerreraBorquez2018,
  author    = {Herrera Borquez, Kenya},
  title     = {La cabrona aqu{\´i} soy yo},
  doi       = {10.25932/publishup-42368},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-423686},
  school      = {Universit{\"a}t Potsdam},
  pages     = {277},
  year      = {2018},
  abstract  = {La {\´u}ltima d{\´e}cada ha visto un inter{\´e}s creciente en el fen{\´o}meno del narcotr{\´a}fico en M{\´e}xico a nivel global. Las diversas expresiones de violencia extrema que acompa{\~n}an al negocio ilegal de drogas se narran en artefactos medi{\´a}ticos que provocan fascinaci{\´o}n e intriga. As{\´i}, la literatura y el cine, la m{\´u}sica y la televisi{\´o}n presentan im{\´a}genes e historias sobre el narcotr{\´a}fico que alimentan el imaginario colectivo. En este contexto, a nivel global hay representaciones medi{\´a}ticas de la mujer mexicana narcotraficante que reproducen estereotipos femeninos donde la mujer se cosifica, exagerando los atributos sexuales del cuerpo de las mujeres. Esta representaci{\´o}n cultural hace de la mujer un objeto de deseo, cuya belleza sirve como una marca de prestigio y ostentaci{\´o}n para el hombre narcotraficante. La cultura del narcotr{\´a}fico impone a las mujeres un ideal est{\´e}tico particular distintivo, que las mujeres reproducen meticulosamente para emular esta representaci{\´o}n. Aunado a la belleza f{\´i}sica, la mujer es retratada violenta y sin escr{\´u}pulos, usa su belleza y poder de seducci{\´o}n para acumular dinero y poder a costa de los hombres que conquista. Para los que no pertenecen al mundo del narcotr{\´a}fico, este tipo de mujer, hipersexualizada, inspira juicios negativos, discriminaci{\´o}n, desconfianza y temor. La intenci{\´o}n de la pregunta y objetivos de investigaci{\´o}n de este trabajo fue rebasar estas representaciones para observar las complejidades de las experiencias de vida de estas mujeres. El prop{\´o}sito de esta tesis de doctorado fue explorar c{\´o}mo cambian las vidas de las mujeres mexicanas cuando se involucran en la narcocultura, en la frontera M{\´e}xico-Estados Unidos. En espec{\´i}fico, la investigaci{\´o}n analiz{\´o} las transformaciones en la corporalidad y en las subjetividades de estas mujeres, y c{\´o}mo estas transformaciones influ{\´i}an en el lugar que ocupan en el espacio social y cultural que configura el narcotr{\´a}fico. Adem{\´a}s, se analiz{\´o} qu{\´e} m{\´a}rgenes de negociaci{\´o}n tienen las mujeres en la narcocultura, para poder actuar y definirse a s{\´i} mismas. Las preguntas que guiaron el trabajo indagaban sobre c{\´o}mo las mujeres cambiaban su cuerpo para encarnar el ideal est{\´e}tico y qu{\´e} significados se atribu{\´i}an a estos cambios. Fue importante analizar qu{\´e} din{\´a}micas de poder se pon{\´i}an en juego a partir de estos cuerpos femeninos, en las relaciones con los hombres y con otras mujeres. Tambi{\´e}n, otro objetivo fue qu{\´e} procesos de subjetivaci{\´o}n operaban en las mujeres que participan en la narcocultura, y qu{\´e} m{\´a}rgenes de negociaci{\´o}n ten{\´i}an para actuar y definirse a s{\´i} mismas. Esta es una investigaci{\´o}n inscrita dentro de los estudios culturales y con una perspectiva feminista interseccional. La investigaci{\´o}n se realiz{\´o} en la frontera mexicana con Estados Unidos, en el noroeste, espec{\´i}ficamente en las ciudades de Mexicali, Tijuana y San Diego, California. La frontera, en esta tesis, se observa como un espacio con m{\´u}ltiples contextos de interpretaci{\´o}n, polis{\´e}mico y heterog{\´e}neo. Estas cualidades hacen que los fen{\´o}menos culturales que ocurren en {\´e}l sean diversos y contradictorios. Para entender los fen{\´o}menos culturales que emergen de la frontera norte de M{\´e}xico, fue {\´u}til el concepto de transfrontera de Jos{\´e} Valenzuela Arce (2014). La propuesta de este acad{\´e}mico es que las transfronteras son "espacios que se niegan a una sola de las condiciones o los lados que la integran" (p. 9). As{\´i}, el concepto habla de los procesos de conectividad y simultaneidad que la globalizaci{\´o}n genera y que redefinen a los Estados-territorio. Al mismo tiempo, habla tambi{\´e}n de los l{\´i}mites que estos mismos Estados utilizan para sostener narrativas nacionales que son "referentes organizadores de adscripciones identitarias y culturales" (p. 18) que crean diferencias y desigualdades. Si esto es as{\´i}, una frontera no se explica completamente desde la demarcaci{\´o}n territorial o desde la diferenciaci{\´o}n jer{\´a}rquica que incluye a algunos y excluye a otros, pero tampoco puede entenderse si nos concentramos solamente en los procesos de hibridaci{\´o}n cultural que ocurren en esos espacios. Por eso, para Valenzuela las fronteras son entre espacios y entre tiempos. Este concepto ayuda a entender c{\´o}mo se intersecta lo global y local en los sistemas semi{\´o}ticos que componen el universo cultural del narcotr{\´a}fico mexicano, al mismo tiempo que explica c{\´o}mo se estructuran mecanismos de exclusi{\´o}n y jerarqu{\´i}as a partir del g{\´e}nero, la posici{\´o}n social y otras marcas de diferenciaci{\´o}n social. En {\´u}ltima instancia, ayuda a localizar estos procesos culturales, materializados en el cuerpo de las mujeres. El concepto de narcocultura tambi{\´e}n fue una herramienta heur{\´i}stica {\´u}til. La cultura aqu{\´i} se entiende como un proceso de producci{\´o}n y reproducci{\´o}n de modelos simb{\´o}licos, materializados en artefactos o representaciones y, adem{\´a}s, interiorizados en l{\´o}gicas de vida, sistemas de valores y creencias, que circulan a trav{\´e}s de las pr{\´a}cticas individuales y colectivas de mujeres y hombres, en contextos hist{\´o}ricos y espaciales espec{\´i}ficos. La narcocultura ser{\´i}a entonces el sistema semi{\´o}tico producido en torno al negocio transnacional de tr{\´a}fico ilegal de drogas, tal como se vive en la frontera norte de M{\´e}xico. La narcocultura, tal como se define en este trabajo es un sistema semi{\´o}tico con l{\´i}mites difusos. As{\´i}, las distinciones entre el mundo ilegal del narcotr{\´a}fico y el mundo de la legalidad externo a este negocio, en el mejor de los casos son borrosas, en el peor, ficticias. La narcocultura trasciende l{\´i}mites territoriales, es un fen{\´o}meno cultural transnacional. Fue necesario delinear las caracter{\´i}sticas de los estudios culturales latinoamericanos y los Kulturwissenschaften en Alemania, para distinguir las genealog{\´i}as de estas dos diferentes perspectivas, entender sus diferencias, pero, sobre todo, encontrar los puntos en com{\´u}n entre ellas. La coincidencia central fue el car{\´a}cter transdisciplinario de estas dos tradiciones acad{\´e}micas. Los estudios culturales entonces se entienden como un espacio de articulaci{\´o}n entre disciplinas (Castro G{\´o}mez, 2002), que no tiene como objetivo la unificaci{\´o}n sino la pluralizaci{\´o}n de significados, actitudes y modos de percepci{\´o}n (Bachmann-Medick, 2016). La transdisciplina permite trazar las complejidades de los fen{\´o}menos culturales, creando puentes entre diferentes formas de conocimiento y pr{\´a}cticas de investigaci{\´o}n. El feminismo interseccional es una perspectiva central en el trabajo de investigaci{\´o}n. Una contribuci{\´o}n del feminismo a los estudios culturales que influye en esta investigaci{\´o}n es cuestionar "Hombre" y "Mujer" como esencias naturales dadas e inmutables, desde la premisa que "los signos "hombre" y "mujer" son construcciones discursivas que el lenguaje de la cultura proyecta e inscribe en el escenario de los cuerpos, disfrazando sus montajes de signos tras la falsa apariencia de que lo masculino y lo femenino son verdades naturales, ahist{\´o}ricas" (Richard, 2009, p. 77). Los estudios culturales feministas suponen que estos signos se construyen en un sistema de representaciones que articulan subjetividades en mundos culturales concretos. Su objetivo entonces es develar en las pr{\´a}cticas significantes, los elementos ideol{\´o}gicos que configuran los signos y los conflictos que se suscitan a trav{\´e}s del uso e interpretaci{\´o}n de {\´e}stos. Estos signos adquieren m{\´u}ltiples significados y lecturas de acuerdo con especificidades que se distinguen en la diferencia. La interseccionalidad, dentro del feminismo es un discurso te{\´o}rico y metodol{\´o}gico que aboga por reconocer que el signo "mujer" no es una categor{\´i}a absoluta, y por lo tanto no puede explicar por s{\´i} misma las variadas experiencias vitales de las mujeres. Las diferencias se vuelven legibles cuando se ponen en juego con otras categor{\´i}as sociales como la posici{\´o}n social, la raza, la edad y la discapacidad. Las diferencias sociales est{\´a}n fincadas en diferentes discursos que naturalizan los diferentes atributos de estas categor{\´i}as sociales cuando, para esta perspectiva, son socialmente construidos y cambiantes. El objetivo de una perspectiva interseccional es identificar c{\´o}mo interact{\´u}an diferentes categor{\´i}as sociales en instituciones, pr{\´a}cticas y subjetividades, para entender c{\´o}mo se materializan las desigualdades a trav{\´e}s del tiempo. Los conceptos te{\´o}ricos que gu{\´i}an esta tesis son cuerpo y subjetividad. Para esta tesis, el cuerpo se entiende como un sitio de articulaci{\´o}n, donde se materializan c{\´o}digos culturales y el orden social. El cuerpo puede entenderse como una frontera din{\´a}mica y mutable, donde convergen lo f{\´i}sico, lo simb{\´o}lico y lo social. Sujeto y cuerpo son mutuamente constitutivos; el cuerpo es el medio a trav{\´e}s del cual el sujeto vive experiencias en el mundo social, y son esas experiencias las que llevan al sujeto a encarnar las diferencias sociales, materializadas en g{\´e}nero, sexo, clase social y raza. A pesar de esta relaci{\´o}n indisociable, para facilitar el an{\´a}lisis, una parte se concentra en el cuerpo y otra en la subjetividad. As{\´i}, para entender la dimensi{\´o}n corporal se puso en tensi{\´o}n la representaci{\´o}n con la experiencia vivida, a trav{\´e}s del an{\´a}lisis audiovisual y la observaci{\´o}n etnogr{\´a}fica le{\´i}da en conjunto. En el caso de la subjetividad, se puso en tensi{\´o}n la vida en la narrativa de ficci{\´o}n con las narraciones de vida en entrevistas, para tambi{\´e}n encontrar los puentes entre las representaciones y la experiencia vital. Esta investigaci{\´o}n fue un estudio cualitativo y transdisciplinario. Se utilizaron diversos recursos metodol{\´o}gicos para construir el an{\´a}lisis. Se realiz{\´o} observaci{\´o}n etnogr{\´a}fica en diversos bares y clubs a ambos lados de la frontera, que son frecuentados por personas que se adscriben al mundo de la narcocultura o bien, que trabajan dentro de las redes del narcotr{\´a}fico. En las incursiones a estos sitios, se observ{\´o} el f{\´i}sico de las mujeres: su manera de vestir, su arreglo personal, sus formas corporales. Se observ{\´o} la conducta: las gestualidades y las interacciones con otros sujetos en el espacio. Adem{\´a}s, se observ{\´o} el espacio, para ver c{\´o}mo se establec{\´i}an reglas, l{\´i}mites y jerarquizaciones en la disposici{\´o}n f{\´i}sica de los lugares visitados. Se analizaron tres videos de narcocorridos a trav{\´e}s de la video hermen{\´e}utica, para determinar c{\´o}mo se representan las mujeres en estos artefactos culturales, usando los mismos criterios f{\´i}sicos y conductuales que mencion{\´e} anteriormente. El an{\´a}lisis de los videos de la mano del trabajo etnogr{\´a}fico ayud{\´o} a profundizar en los significados atribuidos a la corporalidad femenina, y tambi{\´e}n a los impactos que estos significados tienen en las vivencias y relaciones de estas mujeres. Se realizaron 5 entrevistas semi estructuradas con mujeres que se identificaban con la narcocultura. Algunas s{\´o}lo simpatizan con el estilo de vida, otras estuvieron involucradas de alguna manera en el negocio ilegal de drogas. En las entrevistas se exploraron narraciones sobre sus vidas donde se revelaban discursos sobre qu{\´e} es lo femenino, qu{\´e} significa ser mujer y c{\´o}mo se vive el ser mujer en el mundo del narcotr{\´a}fico. Adicionalmente, utilic{\´e} las narraciones de dos textos literarios de la narrativa sobre narcotr{\´a}fico del norte de M{\´e}xico. En estos dos textos, los personajes principales son mujeres. Analic{\´e} c{\´o}mo se construye al sujeto femenino en la narraci{\´o}n y qu{\´e} discursos se transparentan en el texto sobre la feminidad y ser una mujer en el mundo del narco. Aqu{\´i} tambi{\´e}n se puso en tensi{\´o}n la representaci{\´o}n y la experiencia de vida, buscando en el an{\´a}lisis de la narraci{\´o}n literaria y las experiencias narradas por las mujeres, discursos comunes que explicaran los procesos de subjetivaci{\´o}n femenina dentro de la narcocultura mexicana. La primera parte del an{\´a}lisis articul{\´o} la observaci{\´o}n etnogr{\´a}fica con el material audiovisual para entender las exigencias est{\´e}ticas que la narcocultura demanda a las mujeres y las maneras en que ellas transforman su cuerpo para complacer esta demanda. La narcocultura impone a las mujeres un ideal est{\´e}tico que se convierte en un medio de acceso a un tipo de poder. Este ideal exige un tipo particular de fisonom{\´i}a y de apariencia personal, que las mujeres intentan reproducir a trav{\´e}s de intervenciones en el cuerpo, con el maquillaje y el peinado y/o la cirug{\´i}a est{\´e}tica. Adem{\´a}s, demanda cierto estilo de moda, en ropa y accesorios, de marcas de lujo de consumo global. Entre m{\´a}s fielmente se reproduzca este ideal, las mujeres est{\´a}n en posibilidad de acceder a beneficios econ{\´o}micos y sociales que les dan m{\´a}rgenes de acci{\´o}n dentro de este entorno social. El cuerpo de las mujeres se convierte en el recurso primario para la movilidad social y la agencia dentro de este mundo. El cuerpo es el signo principal para determinar el lugar de las mujeres dentro de los sistemas de jerarquizaci{\´o}n, de inclusi{\´o}n y exclusi{\´o}n en los espacios f{\´i}sicos y sociales que fabrica el narcotr{\´a}fico. Estos mecanismos de diferencia reproducen las desigualdades sociales, de g{\´e}nero, edad, posici{\´o}n social y raza que se observan en otros {\´a}mbitos de la sociedad mexicana. La observaci{\´o}n etnogr{\´a}fica y el an{\´a}lisis audiovisual revelan que las posibilidades para performar la feminidad est{\´a} confinado a limites muy estrechos. Alicia Gaspar de Alba llama a esto The Three Maria Syndrome, que ella define como "the patriarchal social discourse of Chicano/Mexicano culture that constructs women's gender and sexuality according to three Biblical archetypes -virgins, mothers and whores-" (Gaspar de Alba, 2014, pos.3412). Estas representaciones femeninas son alegor{\´i}as a las constricciones que la cultura machista mexicana impone sobre las mujeres, someti{\´e}ndolas a un repertorio restringido de opciones de vida y al control social de su sexualidad. Las mujeres dentro de la narcocultura tienen un lugar en {\´e}l en funci{\´o}n de su belleza f{\´i}sica, el cuerpo es el referente principal para definirse como sujetos. Las mujeres son objetos de deseo, cuya belleza es una joya m{\´a}s para la corona de un narcotraficante, una posesi{\´o}n m{\´a}s para ostentar su poder{\´i}o. Al mismo tiempo, aparecen cada vez m{\´a}s las representaciones femeninas como sujetos activos, participando del negocio y de la violencia a la par de los hombres. Se observan transgresiones al ideal de feminidad que se exige a la mujer tradicional en la cultura mexicana. La docilidad, la suavidad y la sumisi{\´o}n que se espera, el recato y la compostura, no est{\´a} presente. Las mujeres adoptan cualidades consideradas masculinas, tomando para s{\´i} el ejercicio de la violencia y la agresividad sexual para demostrar que ellas tambi{\´e}n pueden navegar un mundo agresivo e hipermasculino. A pesar de esto, esta mujer guerrera y valiente est{\´a} dentro de los confines limitados que la cultura patriarcal impone al r{\´e}gimen heterosexual. Siguen al pie de la letra la prescripci{\´o}n del Three Maria Syndrome. Esto queda patente un sistema de jerarquizaci{\´o}n a trav{\´e}s de la cual se eval{\´u}a a las mujeres dentro de la narcocultura. Las mujeres son juzgadas a partir de criterios que intersectan componentes raciales, de g{\´e}nero y de clase. Aunque las maneras en las que estas marcas de diferencia se encarnan en un cuerpo femenino de manera muy diversa, se puede identificar, a trav{\´e}s de las representaciones y la observaci{\´o}n etnogr{\´a}fica, que las mujeres m{\´a}s privilegiadas, son mujeres que encarnan los signos de una posici{\´o}n econ{\´o}mica alta: tienen tez clara, son atractivas y cuidan su apariencia para presentar signos de feminidad de manera discreta, y su conducta proyecta compostura y respetabilidad, en funci{\´o}n de su restricci{\´o}n, particularmente en la expresi{\´o}n de la sexualidad. A las mujeres que encarnan estos signos de feminidad se les respeta y se consideran valiosas. Su valor se formaliza a trav{\´e}s de la respetabilidad del contrato matrimonial: este tipo de performance de g{\´e}nero lo reproducen, por lo general, mujeres esposas de narcotraficantes. En el otro extremo del espectro est{\´a}n las mujeres menos valoradas: son mujeres morenas, que utilizan una est{\´e}tica asociada con la clase trabajadora, por lo general ostentosa y recargada de decoraciones. La conducta de estas mujeres se juzga como vulgar y sin restricciones. A las mujeres que encarnan este tipo de feminidad se les discrimina y cosifica, son las m{\´a}s vulnerables a la violencia en funci{\´o}n del poco valor que tienen dentro del mundo del narcotr{\´a}fico. La buchona representa una versi{\´o}n devaluada de la feminidad, que choca con el decoro y la discreci{\´o}n que exigen las normas tradicionales de g{\´e}nero. Son mujeres que se consideran vulgares, porque sus cuerpos portan signos de una sexualidad agresiva, porque adoptan conductas que irrumpen las restricciones sociales impuestas a las mujeres, porque sus pr{\´a}cticas y consumos culturales est{\´a}n asociadas a las clases trabajadoras y rurales. En las mujeres que entrevist{\´e} hay un conflicto entre la atractiva libertad que promete la transgresi{\´o}n de ser buchona y el deseo de respetabilidad que otorga ser una mujer que cumple con lo que la sociedad exige. Uno de los dilemas al centro de performar el cuerpo buch{\´o}n es la batalla entre una feminidad aceptada socialmente, pero restrictiva y una feminidad que otorga poder, pero castiga. Por este motivo, las mujeres que entrevist{\´e} rechazaban ser nombradas como buchonas y prefer{\´i}an llamarse a s{\´i} mismas cabronas. En este contexto particular, la palabra cabrona es una resignificaci{\´o}n de un t{\´e}rmino coloquial castellano, usado para ofender. Aqu{\´i}, la mujer cabrona se convierte en un eje articulador para la constituci{\´o}n de subjetividades femeninas dentro de la narcocultura. La cabrona es un tropo femenino que entrelaza narrativas sobre ser mujer que circulan a nivel global con narrativas locales sobre la feminidad. Asumirse "cabrona", se convierte en un recurso para enfrentar un mundo violento y encontrar estrategias de acci{\´o}n en un espacio claramente dominado por los hombres. La cabrona representa independencia y fuerza, autonom{\´i}a y acci{\´o}n. La cabrona confronta los discursos tradicionales de una feminidad abnegada y d{\´o}cil, con diferentes matices, aparentemente interpelando la dominaci{\´o}n masculina. Por lo mismo, carga un fuerte estigma. La cultura de masas tambi{\´e}n produce representaciones sobre la cabrona. Se transmiten en discursos de g{\´e}nero que circulan a trav{\´e}s de im{\´a}genes en las redes sociales, en libros y workshops del mercado de autoayuda en el mundo entero, y que promueven una idea de mujer ind{\´o}cil frente a la gente de su entorno, suscrita al consumo y al individualismo de la cultura capitalista. En estas representaciones culturales contempor{\´a}neas, la mujer es fuerte e insumisa, pero conservando c{\´o}digos corporales y pr{\´a}cticas femeninas. En el contexto concreto de la narcocultura, los discursos globales sobre una mujer fuerte e independiente con poder econ{\´o}mico y a cargo de su sexualidad, se encuentran con las condiciones particulares del norte mexicano. La violencia extrema, el machismo, las desigualdades sociales pronunciadas y la crisis de legitimidad del Estado intervienen para que estos discursos globales sobre la mujer muten en la representaci{\´o}n de la buchona y la cabrona, interpretaciones locales de un discurso de g{\´e}nero global. Para las mujeres, asumirse cabrona es un recurso para enfrentar un mundo violento y encontrar estrategias de acci{\´o}n en un espacio claramente dominado por los hombres. Ayuda a enfrentar la violencia perpetrada sobre ella, abre la posibilidad a ser la victimaria. La cabrona es la reacci{\´o}n que provoca el cuerpo femenino vulnerable y vulnerado, pero tambi{\´e}n, es la posibilidad de apropiarse de la violencia para ejercerla sobre otros cuerpos. Implica independencia, libertad sexual y {\´e}xito econ{\´o}mico, evidenciadas por el consumo y el estilo de vida. Cuando niegan ser buchonas, est{\´a}n rechazando todos los estigmas que acarrea la palabra. No se reconocen en la discriminaci{\´o}n de clase, las connotaciones raciales y los prejuicios sexistas que contiene. Prefieren cabrona porque es una manera de escindirse de los discursos negativos que se vuelcan sobre ellas, es un camino de acceso a una feminidad global que los medios de comunicaci{\´o}n masiva presentan como ideal. El an{\´a}lisis explor{\´o} qu{\´e} elementos compon{\´i}an este tropo femenino a trav{\´e}s de las entrevistas a mujeres y de personajes femeninos en novelas sobre narcotr{\´a}fico, para encontrar puentes entre la ficci{\´o}n y la experiencia vital. La belleza y la capacidad de seducir tiene una utilidad ambivalente. Por un lado, todo el tiempo, dinero y cuidado que se invierte en apropiarse de un ideal est{\´e}tico, es para convertirse en una mujer que un narco pueda presumir. Para las mujeres es un motivo de orgullo saberse deseadas y puestas en aparador. Las mujeres est{\´a}n sometidas a las presiones que genera la creencia de que, para sobrevivir, hay que ser bella. En los textos literarios y en las entrevistas, se transparenta una naturalizaci{\´o}n del lugar de la mujer como objeto de ostentaci{\´o}n para el hombre y, adem{\´a}s, la validaci{\´o}n que sienten las mujeres al ser reconocidas como bellas. La ficci{\´o}n y la vida nos presentan la precaria condici{\´o}n del sujeto femenino en la narcocultura. Es una subjetividad anclada a los discursos que demandan un ideal de belleza imposible para las mujeres y que encajonan el ser mujer a los caprichos y necesidades del hombre. Sin embargo, la belleza femenina tiene otra faceta. La subjetividad femenina en la narcocultura no s{\´o}lo es resultado del sometimiento de la mujer a los discursos que regulan su apariencia y su conducta. La belleza tambi{\´e}n es un instrumento al servicio de las mujeres para acceder a dinero y poder. La belleza y el poder de seducci{\´o}n femenino se convierten en estrategias de subsistencia, y esto transforma a la mujer de un objeto sometido a un sujeto que somete. La belleza y la seducci{\´o}n podr{\´a}n dar a las mujeres ciertos m{\´a}rgenes de acci{\´o}n, pero esto tiene l{\´i}mites muy claros. Aunque estas estrategias femeninas muevan la balanza de poder hac{\´i}a el sujeto femenino, hay que recordar el contexto. Est{\´a}n insertas en un mundo violento y machista, as{\´i} que ejercer ese poder es un ejercicio de equilibrio muy delicado y arriesgado. Las mujeres que habitan la narcocultura est{\´a}n inmersas es un mundo de violencia, y no conocer y respetar las reglas y l{\´i}mites significa un riesgo de muerte. La muerte violenta es una consecuencia muy real por cometer errores en este mundo. Esto lleva a tercer componente de ser cabrona: el riesgo. Para los hombres y mujeres que se involucran en el mundo cultural del narcotr{\´a}fico, perseguir el riesgo es parte integral de vivir y es una parte importante de la constituci{\´o}n de subjetividades en la narcocultura. En las narraciones de las entrevistas y en las narraciones literarias, hay muchos momentos donde las mujeres viven situaciones de riesgo que ponen en peligro hasta sus vidas. A trav{\´e}s de las narraciones se asoma la manera en qu{\´e} ellas interpretan su papel en la situaci{\´o}n y c{\´o}mo se ven a s{\´i} mismas en funci{\´o}n de esas experiencias. El riesgo le da sentido al car{\´a}cter recio y atrevido que demanda asumir el rol de una cabrona, pero tambi{\´e}n expone la vulnerabilidad de la condici{\´o}n de las mujeres en un mundo violento. Tomar riesgos es otra manera de afirmarse como mujeres fuertes y poner distancia con las disposiciones de g{\´e}nero que les exigen ser d{\´o}ciles y pasivas. Tienen que demostrar lo que valen frente a un mundo dominado por hombres y el control de sus emociones juega un rol fundamental en lograr esto. Sin embargo, el reconocimiento del miedo y vulnerabilidad es, parad{\´o}jicamente, lo que las ayuda a sobrevivir. Detr{\´a}s de los discursos de fuerza y poder femenino, se revela la fragilidad de unas vidas sumergidas en un mundo donde la violencia y el machismo deja a las mujeres en el filo de la vida y de la muerte. Para el caso que nos compete, el vac{\´i}o institucional para garantizar seguridad a las mujeres en M{\´e}xico deja a estas mujeres absolutamente expuestas, y cobra sentido la adopci{\´o}n del discurso de la cabrona como estrategia de persistencia. Al investirse como cabronas, encuentran una manera de enfrentarse al mundo violento al que deciden pertenecer, aunque al final de cuentas, permanecen atrapadas en {\´e}l.},
  language  = {es}
}
@phdthesis{Roder2018,
  author    = {Roder, Phillip},
  title     = {Kombination von Fluoreszenzmikroskopie und Rasterkraftmikroskopie zur Aufkl{\"a}rung physiologischer Prozesse in lebenden Zellen},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419806},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvi, 113},
  year      = {2018},
  abstract  = {Innerhalb dieser Doktorarbeit wurde eine neuartige Mikromanipulationstechnik f{\"u}r die lokale Fl{\"u}ssigkeitsabgabe am komplexen Dr{\"u}sengewebe der Schabe P. americana charakterisiert und f{\"u}r die damit verbundene gezielte Manipulation von einzelnen Zellen in einem Zellkomplex (Gewebe) angewandt. Bei dieser Mikromanipulationstechnik handelt es sich um die seit 2009 bekannte nanofluidische Rasterkraftmikroskopie (FluidFM = fluidic force microscopy). Dabei werden sehr kleine mikrokan{\"a}lige Rasterkraftspitzen bzw. Mikro-/Nanopipetten mit einer {\"O}ffnung zwischen 300 nm und 2 µm verwendet, mit denen es m{\"o}glich ist, sehr kleine Volumina im Pikoliter- bis Femtoliter-Bereich (10-12 L - 10-15 L) gezielt und ortsgenau abzugeben. Das Ziel dieser Arbeit war die Analyse zellul{\"a}rer Prozesse, wie z. B. Zell-Zell-Kommunikation oder Signalweiterleitung, zwischen benachbarten Zellen unter Zuhilfenahme der Fluoreszenzmikroskopie. Mit dieser Methode k{\"o}nnen die Zellen und ihre Bestandteile mittels vorheriger Farbstoffbeladung unter einem Mikroskop mit hohem Kontrast optisch dargestellt werden. Mit Hilfe der Fluoreszenzmikroskopie sollten schlussendlich die zellul{\"a}ren Reaktionen innerhalb des Gewebes nach der lokalen Manipulation visualisiert werden. Zun{\"a}chst wurde die Anwendung des Systems an Luft und w{\"a}ssriger Umgebung beschrieben. In diesem Zusammenhang wurde eine Reinigungs- und Beladungsmethode entwickelt, mit der es m{\"o}glich war, die kostspieligen Mikro-/Nanopipetten zu reinigen und anschließend mehrmals wiederzuverwenden. Hierzu wurde eine alternative Methode getestet, mit der das Diffusionsverhalten von Farbstoffmolek{\"u}len in unterschiedlichen Medien untersucht werden kann. Des Weiteren wurden die Systemparameter optimiert, welche n{\"o}tig sind, um zwischen der Probenoberfl{\"a}che und der Pipette einen guten Pipetten{\"o}ffnungs-abschluss zu erhalten. Dieser Abschluss ist essentiell, damit die abgegebene Fl{\"u}ssigkeit ausschließlich in der Abgaberegion mit der Probe wechselwirkt und die darauffolgenden Reaktionen nur innerhalb des Gewebes erfolgen, da ansonsten die Zell-Zell-Signalweiterleitung zwischen den Zellen nicht eindeutig nachvollzogen werden kann. Diese interzellul{\"a}re Kommunikation wurde anhand zweier sekund{\"a}rer Botenstoffe (Ca2+ und NO) untersucht. Hierbei war es m{\"o}glich einzelne lokale Reaktionen zu detektieren, welche sich {\"u}ber weitere Zellen ausbreiteten. Schlussendlich wurde die Fertigung einer speziellen Injektionspipette beschrieben, welche an zwei biologischen Systemen getestet wurde.},
  language  = {de}
}
@phdthesis{Abouserie2018,
  author    = {Abouserie, Ahed},
  title     = {Ionic liquid precursors for multicomponent inorganic nanomaterials},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418950},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xx, 193},
  year      = {2018},
  abstract  = {Health effects, attributed to the environmental pollution resulted from using solvents such as benzene, are relatively unexplored among petroleum workers, personal use, and laboratory researchers. Solvents can cause various health problems, such as neurotoxicity, immunotoxicity, and carcinogenicity. As such it can be absorbed via epidermal or respiratory into the human body resulting in interacting with molecules that are responsible for biochemical and physiological processes of the brain. Owing to the ever-growing demand for finding a solution, an Ionic liquid can use as an alternative solvent. Ionic liquids are salts in a liquid state at low temperature (below 100 C), or even at room temperature. Ionic liquids impart a unique architectural platform, which has been interesting because of their unusual properties that can be tuned by simple ways such as mixing two ionic liquids. Ionic liquids not only used as reaction solvents but they became a key developing for novel applications based on their thermal stability, electric conductivity with very low vapor pressure in contrast to the conventional solvents. In this study, ionic liquids were used as a solvent and reactant at the same time for the novel nanomaterials synthesis for different applications including solar cells, gas sensors, and water splitting. The field of ionic liquids continues to grow, and become one of the most important branches of science. It appears to be at a point where research and industry can work together in a new way of thinking for green chemistry and sustainable production.},
  language  = {en}
}
@phdthesis{TchoumbaKwamen2018,
  author    = {Tchoumba Kwamen, Christelle Larodia},
  title     = {Investigating the dynamics of polarization reversal in ferroelectric thin films by time-resolved X-ray diffraction},
  doi       = {10.25932/publishup-42781},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427815},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvii, 126, xxiii},
  year      = {2018},
  abstract  = {Ferroic materials have attracted a lot of attention over the years due to their wide range of applications in sensors, actuators, and memory devices. Their technological applications originate from their unique properties such as ferroelectricity and piezoelectricity. In order to optimize these materials, it is necessary to understand the coupling between their nanoscale structure and transient response, which are related to the atomic structure of the unit cell. In this thesis, synchrotron X-ray diffraction is used to investigate the structure of ferroelectric thin film capacitors during application of a periodic electric field. Combining electrical measurements with time-resolved X-ray diffraction on a working device allows for visualization of the interplay between charge flow and structural motion. This constitutes the core of this work. The first part of this thesis discusses the electrical and structural dynamics of a ferroelectric Pt/Pb(Zr0.2,Ti0.8)O3/SrRuO3 heterostructure during charging, discharging, and polarization reversal. After polarization reversal a non-linear piezoelectric response develops on a much longer time scale than the RC time constant of the device. The reversal process is inhomogeneous and induces a transient disordered domain state. The structural dynamics under sub-coercive field conditions show that this disordered domain state can be remanent and can be erased with an appropriate voltage pulse sequence. The frequency-dependent dynamic characterization of a Pb(Zr0.52,Ti0.48)O3 layer, at the morphotropic phase boundary, shows that at high frequency, the limited domain wall velocity causes a phase lag between the applied field and both the structural and electrical responses. An external modification of the RC time constant of the measurement delays the switching current and widens the electromechanical hysteresis loop while achieving a higher compressive piezoelectric strain within the crystal. In the second part of this thesis, time-resolved reciprocal space maps of multiferroic BiFeO3 thin films were measured to identify the domain structure and investigate the development of an inhomogeneous piezoelectric response during the polarization reversal. The presence of 109° domains is evidenced by the splitting of the Bragg peak. The last part of this work investigates the effect of an optically excited ultrafast strain or heat pulse propagating through a ferroelectric BaTiO3 layer, where we observed an additional current response due to the laser pulse excitation of the metallic bottom electrode of the heterostructure.},
  language  = {en}
}
@phdthesis{Muench2018,
  author    = {M{\"u}nch, Thomas},
  title     = {Interpretation of temperature signals from ice cores},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414963},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxi, 197},
  year      = {2018},
  abstract  = {Earth's climate varies continuously across space and time, but humankind has witnessed only a small snapshot of its entire history, and instrumentally documented it for a mere 200 years. Our knowledge of past climate changes is therefore almost exclusively based on indirect proxy data, i.e. on indicators which are sensitive to changes in climatic variables and stored in environmental archives. Extracting the data from these archives allows retrieval of the information from earlier times. Obtaining accurate proxy information is a key means to test model predictions of the past climate, and only after such validation can the models be used to reliably forecast future changes in our warming world. The polar ice sheets of Greenland and Antarctica are one major climate archive, which record information about local air temperatures by means of the isotopic composition of the water molecules embedded in the ice. However, this temperature proxy is, as any indirect climate data, not a perfect recorder of past climatic variations. Apart from local air temperatures, a multitude of other processes affect the mean and variability of the isotopic data, which hinders their direct interpretation in terms of climate variations. This applies especially to regions with little annual accumulation of snow, such as the Antarctic Plateau. While these areas in principle allow for the extraction of isotope records reaching far back in time, a strong corruption of the temperature signal originally encoded in the isotopic data of the snow is expected. This dissertation uses observational isotope data from Antarctica, focussing especially on the East Antarctic low-accumulation area around the Kohnen Station ice-core drilling site, together with statistical and physical methods, to improve our understanding of the spatial and temporal isotope variability across different scales, and thus to enhance the applicability of the proxy for estimating past temperature variability. The presented results lead to a quantitative explanation of the local-scale (1-500 m) spatial variability in the form of a statistical noise model, and reveal the main source of the temporal variability to be the mixture of a climatic seasonal cycle in temperature and the effect of diffusional smoothing acting on temporally uncorrelated noise. These findings put significant limits on the representativity of single isotope records in terms of local air temperature, and impact the interpretation of apparent cyclicalities in the records. Furthermore, to extend the analyses to larger scales, the timescale-dependency of observed Holocene isotope variability is studied. This offers a deeper understanding of the nature of the variations, and is crucial for unravelling the embedded true temperature variability over a wide range of timescales.},
  language  = {en}
}
@phdthesis{Lopes2018,
  author    = {Lopes, Pedro},
  title     = {Interactive Systems Based on Electrical Muscle Stimulation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421165},
  school      = {Universit{\"a}t Potsdam},
  pages     = {171},
  year      = {2018},
  abstract  = {How can interactive devices connect with users in the most immediate and intimate way? This question has driven interactive computing for decades. Throughout the last decades, we witnessed how mobile devices moved computing into users' pockets, and recently, wearables put computing in constant physical contact with the user's skin. In both cases moving the devices closer to users allowed devices to sense more of the user, and thus act more personal. The main question that drives our research is: what is the next logical step? Some researchers argue that the next generation of interactive devices will move past the user's skin and be directly implanted inside the user's body. This has already happened in that we have pacemakers, insulin pumps, etc. However, we argue that what we see is not devices moving towards the inside of the user's body, but rather towards the body's biological "interface" they need to address in order to perform their function. To implement our vision, we created a set of devices that intentionally borrow parts of the user's body for input and output, rather than adding more technology to the body. In this dissertation we present one specific flavor of such devices, i.e., devices that borrow the user's muscles. We engineered I/O devices that interact with the user by reading and controlling muscle activity. To achieve the latter, our devices are based on medical-grade signal generators and electrodes attached to the user's skin that send electrical impulses to the user's muscles; these impulses then cause the user's muscles to contract. While electrical muscle stimulation (EMS) devices have been used to regenerate lost motor functions in rehabilitation medicine since the 1960s, in this dissertation, we propose a new perspective: EMS as a means for creating interactive systems. We start by presenting seven prototypes of interactive devices that we have created to illustrate several benefits of EMS. These devices form two main categories: (1) Devices that allow users eyes-free access to information by means of their proprioceptive sense, such as the value of a variable in a computer system, a tool, or a plot; (2) Devices that increase immersion in virtual reality by simulating large forces, such as wind, physical impact, or walls and heavy objects. Then, we analyze the potential of EMS to build interactive systems that miniaturize well and discuss how they leverage our proprioceptive sense as an I/O modality. We proceed by laying out the benefits and disadvantages of both EMS and mechanical haptic devices, such as exoskeletons. We conclude by sketching an outline for future research on EMS by listing open technical, ethical and philosophical questions that we left unanswered.},
  language  = {en}
}
@phdthesis{Hesse2018,
  author    = {Hesse, Cornelia},
  title     = {Integrated water quality modelling in meso- to large-scale catchments of the Elbe river basin under climate and land use change},
  doi       = {10.25932/publishup-42295},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-422957},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ix, 217},
  year      = {2018},
  abstract  = {In einer sich {\"a}ndernden Umwelt sind Fließgew{\"a}sser{\"o}kosysteme vielf{\"a}ltigen direkten und indirekten anthropogenen Belastungen ausgesetzt, die die Gew{\"a}sser sowohl in ihrer Menge als auch in ihrer G{\"u}te beeintr{\"a}chtigen k{\"o}nnen. Ein {\"u}berm{\"a}ßiger Eintrag von N{\"a}hrstoffen verursacht etwa Massenentwicklungen von Algen und Sauerstoffdefizite in den Gew{\"a}ssern, was zum Verfehlen der Ziele der Wasserrahmenrichtlinie (WRRL) f{\"u}hren kann. In vielen europ{\"a}ischen Einzugsgebieten und auch dem der Elbe sind solche Probleme zu beobachten. W{\"a}hrend der letzten Jahrzehnte entstanden diverse computergest{\"u}tzte Modelle, die zum Schutz und Management von Wasserressourcen genutzt werden k{\"o}nnen. Sie helfen beim Verstehen der N{\"a}hrstoffprozesse und Belastungspfade in Einzugsgebieten, bei der Absch{\"a}tzung m{\"o}glicher Folgen von Klima- und Landnutzungs{\"a}nderungen f{\"u}r die Wasserk{\"o}rper, sowie bei der Entwicklung eventueller Kompensationsmaßnahmen. Aufgrund der Vielzahl an sich gegenseitig beeinflussenden Prozessen ist die Modellierung der Wasserqualit{\"a}t komplexer und aufw{\"a}ndiger als eine reine hydrologische Modellierung. {\"O}kohydrologische Modelle zur Simulation der Gew{\"a}sserg{\"u}te, einschließlich des Modells SWIM (Soil and Water Integrated Model), bed{\"u}rfen auch h{\"a}ufig noch einer Weiterentwicklung und Verbesserung der Prozessbeschreibungen. Aus diesen {\"U}berlegungen entstand die vorliegende Dissertation, die sich zwei Hauptanliegen widmet: 1) einer Weiterentwicklung des N{\"a}hrstoffmoduls des {\"o}kohydrologischen Modells SWIM f{\"u}r Stickstoff- und Phosphorprozesse, und 2) der Anwendung des Modells SWIM im Elbegebiet zur Unterst{\"u}tzung eines anpassungsf{\"a}higen Wassermanagements im Hinblick auf m{\"o}gliche zuk{\"u}nftige {\"A}nderungen der Umweltbedingungen. Die kumulative Dissertation basiert auf f{\"u}nf wissenschaftlichen Artikeln, die in internationalen Zeitschriften ver{\"o}ffentlicht wurden. Im Zuge der Arbeit wurden verschiedene Modellanpassungen in SWIM vorgenommen, wie etwa ein einfacher Ansatz zur Verbesserung der Simulation der Wasser- und N{\"a}hrstoffverh{\"a}ltnisse in Feuchtgebieten, ein um Ammonium erweiterter Stickstoffkreislauf im Boden, sowie ein Flussprozessmodul, das Umwandlungsprozesse, Sauerstoffverh{\"a}ltnisse und Algenwachstum im Fließgew{\"a}sser simuliert, haupts{\"a}chlich angetrieben von Temperatur und Licht. Auch wenn dieser neue Modellansatz ein sehr komplexes Modell mit einer Vielzahl an neuen Kalibrierungsparametern und steigender Unsicherheit erzeugte, konnten gute Ergebnisse in den Teileinzugsgebieten und dem gesamten Gebiet der Elbe erzielt werden, so dass das Modell zur Absch{\"a}tzung m{\"o}glicher Folgen von Klimavariabilit{\"a}ten und ver{\"a}nderten anthropogenen Einfl{\"u}ssen f{\"u}r die Gew{\"a}sserg{\"u}te genutzt werden konnte. Das neue Fließgew{\"a}ssermodul ist ein wichtiger Beitrag zur Verbesserung der N{\"a}hrstoffmodellierung in SWIM, vor allem f{\"u}r Stoffe, die haupts{\"a}chlich aus Punktquellen in die Gew{\"a}sser gelangen (wie z.B. Phosphat). Der neue Modellansatz verbessert zudem die Anwendbarkeit von SWIM f{\"u}r Fragestellungen im Zusammenhang mit der WRRL, bei der biologische Qualit{\"a}tskomponenten (wie etwa Phytoplankton) eine zentrale Rolle spielen. Die dargestellten Ergebnisse der Wirkungsstudien k{\"o}nnen bei Entscheidungstr{\"a}gern und anderen Akteuren das Verst{\"a}ndnis f{\"u}r zuk{\"u}nftige Herausforderungen im Gew{\"a}ssermanagement erh{\"o}hen und dazu beitragen, ein angepasstes Management f{\"u}r das Elbeeinzugsgebiet zu entwickeln.},
  language  = {en}
}
@phdthesis{Ramage2018,
  author    = {Ramage, Justine Lucille},
  title     = {Impact of Hillslope Thermokarst on the Nearshore Carbon Budget Along the Yukon Coast, Canada},
  doi       = {10.25932/publishup-42186},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421867},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvii, 103},
  year      = {2018},
  abstract  = {In ice-rich permafrost regions, changes in the permafrost thermal regime cause surface disturbances. These changes are amplified by the increase in air temperatures recorded in the Arctic in the past decades. Thermokarst is a process that leads to surface subsidence and formation of characteristic landforms following thawing of ice-rich permafrost or melting of massive ice. Thermokarst is widespread on hillslopes and the number of associated landforms is increasing in the Arctic. Through this process large amounts of material are eroded and transported to the sea or accumulate along hillslopes. While hillslope thermokarst modifies terrestrial and aquatic ecosystems, there is limited understanding of its environmental impact at a regional scale. In this thesis we quantify the environmental impacts of hillslope thermokarst on the valley and nearshore ecosystems along the Yukon Coast, Canada. Using supervised machine learning, we identified geomorphic factors that favour the development of coastal retrogressive thaw slump (RTS), one of the most dynamic hillslope thermokarst landform. Coastal geomorphology and ground ice type and content play a major role in RTS occurrence. Using aerial photographs and satellite imagery, we traced the evolution of RTSs between 1952 and 2011. During this time, the number and areal coverage of RTSs increased by 73\%. RTSs eroded and partly released to the nearshore zone organic carbon contained in millions of cubic meters of material. Our results show that 56\% of the RTSs identified along the coast in 2011 have eroded 16.6 × 10^6 m3 of material; a large part (45\%) was transported alongshore due to coastal processes. Moreover, we show that RTSs are a major contributor to the carbon budget in the nearshore ecosystem: 17\% of the coastal RTSs identified in 2011 contributed annually up to 0.6\% of the organic carbon released by coastal retreat along the Yukon Coast. To assess the impact of hillslope thermokarst on the terrestrial ecosystem, we measured the spatial distribution of soil organic carbon (SOC) and total nitrogen (TN) along hillslopes in three Arctic valleys. We highlight the high spatial variability in the distribution of SOC and TN in the valleys. This distribution is caused by complex soil processes occurring along the hillslopes. Hillslope thermokarst impacts the degradation of organic matter and affects the storage of SOC and TN.},
  language  = {de}
}
@phdthesis{Danckert2018,
  author    = {Danckert, Lena},
  title     = {Immunscreening Virulenz-adaptierter Expressionsbibliotheken aus einem in vitro Infektionsmodell mit Salmonella Enteritidis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421108},
  school      = {Universit{\"a}t Potsdam},
  pages     = {144},
  year      = {2018},
  abstract  = {Die Folgen einer lebensmittelbedingten Erkrankung sind zum Teil gravierend, insbesondere f{\"u}r Kinder und immunsupprimierte Menschen. Hierbei geh{\"o}ren Salmonella und Campylobacter zu den h{\"a}ufigsten Erregern, die verantwortlich f{\"u}r gastrointestinale Erkrankungen in Deutschland sind. Trotz umfassender Maßnahmen der EU zur Pr{\"a}vention und Bek{\"a}mpfung von Salmonellen in Gefl{\"u}gelbest{\"a}nden und der Lebensmittel-Industrie, wird von einem stagnierenden Trend von Infektionszahlen berichtet. Zoonose-Erreger wie Salmonellen k{\"o}nnen {\"u}ber Nutztiere in die Nahrungskette des Menschen gelangen, wodurch sich Infektionsherde schnell ausbreiten k{\"o}nnen. Dabei sind bestehende Pr{\"a}ventionsstrategien f{\"u}r Gefl{\"u}gel vorhanden, die aber nicht auf den Menschen {\"u}bertragbar sind. Folglich sind Diagnostik und Pr{\"a}vention in der Lebensmittelindustrie essentiell. Deshalb besteht ein hoher Bedarf f{\"u}r spezifische, sensitive und zuverl{\"a}ssige Nachweismethoden, die eine Point-of-care Diagnostik gew{\"a}hrleisten. Durch ein wachsendes Verst{\"a}ndnis der wirtsspezifischen Faktoren von S. enterica Serovaren kann die Entwicklung sowohl neuartiger diagnostischer Methoden, als auch neuartiger Therapien und Impfstoffe maßgeblich vorangetrieben werden. Infolgedessen wurde in dieser Arbeit ein infektions{\"a}hnliches in vitro Modell f{\"u}r S. Enteritidis etabliert und darauf basierend eine umfassende Untersuchung zur Identifizierung neuer Zielstrukturen f{\"u}r den Erreger durchgef{\"u}hrt. W{\"a}hrend einer Salmonellen-Infektion ist die erste zellul{\"a}re Barriere im Wirt die Epithelschicht. Dementsprechend wurde eine humane Zelllinie (CaCo 2, Darmepithel) f{\"u}r die Pathogen-Wirt-Studie ausgew{\"a}hlt. Das Salmonellen-Transkriptom und morphologische Eigenschaften der Epithelzellen wurden in verschiedenen Phasen der Salmonellen-Infektion untersucht und mit bereits gut beschriebenen Virulenzfaktoren und Beobachtungen in Bezug gesetzt. Durch dieses Infektionsmodell konnte ein spezifischer Ph{\"a}notyp f{\"u}r die intrazellul{\"a}ren Salmonellen in den Epithelzellen nachgewiesen werden. Zudem wurde aufgezeigt, dass bereits die Kultivierung in Fl{\"u}ssigmedium einen invasionsaktiven Zustand der Salmonellen erzeugt. Allerdings wurde durch die Kokultivierung mit Epithelzellen eine zus{\"a}tzliche Expression relevanter Gene induziert, um eine effiziente Adh{\"a}sion und Transmembran-Transport zu gew{\"a}hrleisten. Letzterer ist charakteristisch f{\"u}r die intrazellul{\"a}re Limitierung von N{\"a}hrstoffen und pr{\"a}gt den infektionsrelevanten Status. Unter Ber{\"u}cksichtigung dieser Faktoren ergab sich ein Ph{\"a}notyp, der eindeutig Mechanismen zur Wirtsadaptation und m{\"o}glicherweise auch Pathogenese aufzeigt. Die intrazellul{\"a}ren Bakterien m{\"u}ssen vom Wirt separiert werden, was ein wesentlicher Schritt f{\"u}r Pathogen-bestimmende Analysen ist. Hierbei wurde mithilfe einer Detergenz-basierten Lyse der eukaryotischen Zellmembran und differentieller Zentrifugation, der eukaryotische Eintrag minimal gehalten. Unter Verwendung der Virulenz-adaptierten Salmonellen wurden Untersuchungen in Hinblick auf die Identifizierung neuer Zielstrukturen f{\"u}r S. Enteritidis durchgef{\"u}hrt. Mithilfe eines immunologischen Screenings wurden neue potentielle Antigene entdeckt. Zu diesem Zweck wurden bakterielle cDNA-basierte Expressionsbibliotheken hergestellt, die durch eine vereinfachte Microarray-Anwendung ein Hochdurchsatzscreening von Proteinen als potentielle Binder erm{\"o}glichen. Folglich konnten neue unbeschriebene Proteine identifiziert werden, die sich durch eine Salmonella-Spezifit{\"a}t oder Membranst{\"a}ndigkeit auszeichnen. Ebenso wurde ein Vergleich der im Screening identifizierten Proteine mit der Regulation der kodierenden Gene im infektions{\"a}hnlichen Modell durchgef{\"u}hrt. Dabei wurde deutlich, dass die H{\"a}ufigkeit von Transkripten einen Einfluss auf die Verf{\"u}gbarkeit in der cDNA-Bibliothek und folglich auch auf die Expressionsbibliothek nimmt. Angesichts eines Ungleichgewichts zwischen der Gesamtzahl protein-kodierender Gene in S. Enteritidis zu m{\"o}glichen Klonen, die w{\"a}hrend des Microarray-Screenings untersucht werden k{\"o}nnen, besteht der Bedarf einer Anreicherung von Proteinen in der Expressionsbibliothek. Das infektions{\"a}hnliche Modell zeigte, dass nicht nur Virulenz-assoziierte, sondern auch Stress- und Metabolismus-relevante Gene hochreguliert werden. Durch die Konstruktion dieser spezifischen cDNA-Bibliotheken ist die Erkennung von charakteristischen molekularen Markern gegeben. Weiterhin wurden anhand der Transkriptomanalyse spezifisch hochregulierte Gene identifiziert, die relevant f{\"u}r das intrazellul{\"a}re {\"U}berleben von S. Enteritidis in humanen Epithelzellen sind. Hiervon wurden drei Gene n{\"a}her untersucht, indem ihr Einfluss im infektions{\"a}hnlichen Modell mittels entsprechender Gen-Knockout-St{\"a}mme analysiert wurde. Dabei wurde f{\"u}r eine dieser Mutanten ein reduziertes Wachstum in der sp{\"a}ten intrazellul{\"a}ren Phase nachgewiesen. Weiterf{\"u}hrende in vitro Analysen sind f{\"u}r die Charakterisierung des Knockout-Stamms notwendig, um den Einsatz als potenzielles Therapeutikum zu verifizieren. Zusammenfassend wurde ein in vitro Infektionsmodell f{\"u}r S. Enteritidis etabliert, wodurch neue Zielstrukturen des Erregers identifiziert wurden. Diese sind f{\"u}r diagnostische oder therapeutische Anwendungen interessant. Das Modell l{\"a}sst sich ebenso f{\"u}r andere intrazellul{\"a}re Pathogene {\"u}bertragen und gew{\"a}hrleistet eine zuverl{\"a}ssige Identifizierung von potentiellen Antigenen.},
  language  = {de}
}
@phdthesis{Rothkegel2018,
  author    = {Rothkegel, Lars Oliver Martin},
  title     = {Human scanpaths in natural scene viewing and natural scene search},
  doi       = {10.25932/publishup-42000},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420005},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xv, 131},
  year      = {2018},
  abstract  = {Understanding how humans move their eyes is an important part for understanding the functioning of the visual system. Analyzing eye movements from observations of natural scenes on a computer screen is a step to understand human visual behavior in the real world. When analyzing eye-movement data from scene-viewing experiments, the impor- tant questions are where (fixation locations), how long (fixation durations) and when (ordering of fixations) participants fixate on an image. By answering these questions, computational models can be developed which predict human scanpaths. Models serve as a tool to understand the underlying cognitive processes while observing an image, especially the allocation of visual attention. The goal of this thesis is to provide new contributions to characterize and model human scanpaths on natural scenes. The results from this thesis will help to understand and describe certain systematic eye-movement tendencies, which are mostly independent of the image. One eye-movement tendency I focus on throughout this thesis is the tendency to fixate more in the center of an image than on the outer parts, called the central fixation bias. Another tendency, which I will investigate thoroughly, is the characteristic distribution of angles between successive eye movements. The results serve to evaluate and improve a previously published model of scanpath generation from our laboratory, the SceneWalk model. Overall, six experiments were conducted for this thesis which led to the following five core results: i) A spatial inhibition of return can be found in scene-viewing data. This means that locations which have already been fixated are afterwards avoided for a certain time interval (Chapter 2). ii) The initial fixation position when observing an image has a long-lasting influence of up to five seconds on further scanpath progression (Chapter 2 \& 3). iii) The often described central fixation bias on images depends strongly on the duration of the initial fixation. Long-lasting initial fixations lead to a weaker central fixation bias than short fixations (Chapter 2 \& 3). iv) Human observers adjust their basic eye-movement parameters, like fixation dura- tions and saccade amplitudes, to the visual properties of a target they look for in visual search (Chapter 4). v) The angle between two adjacent saccades is an indicator for the selectivity of the upcoming saccade target (Chapter 4). All results emphasize the importance of systematic behavioral eye-movement tenden- cies and dynamic aspects of human scanpaths in scene viewing.},
  language  = {en}
}
@phdthesis{Cheng2018,
  author    = {Cheng, Lung-Pan},
  title     = {Human actuation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418371},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xiv, 85},
  year      = {2018},
  abstract  = {Ever since the conception of the virtual reality headset in 1968, many researchers have argued that the next step in virtual reality is to allow users to not only see and hear, but also feel virtual worlds. One approach is to use mechanical equipment to provide haptic feedback, e.g., robotic arms, exoskeletons and motion platforms. However, the size and the weight of such mechanical equipment tends to be proportional to its target's size and weight, i.e., providing human-scale haptic feedback requires human-scale equipment, often restricting them to arcades and lab environments. The key idea behind this dissertation is to bypass mechanical equipment by instead leveraging human muscle power. We thus create software systems that orchestrate humans in doing such mechanical labor—this is what we call human actuation. A potential benefit of such systems is that humans are more generic, flexible, and versatile than machines. This brings a wide range of haptic feedback to modern virtual reality systems. We start with a proof-of-concept system—Haptic Turk, focusing on delivering motion experiences just like a motion platform. All Haptic Turk setups consist of a user who is supported by one or more human actuators. The user enjoys an interactive motion simulation such as a hang glider experience, but the motion is generated by those human actuators who manually lift, tilt, and push the user's limbs or torso. To get the timing and force right, timed motion instructions in a format familiar from rhythm games are generated by the system. Next, we extend the concept of human actuation from 3-DoF to 6-DoF virtual reality where users have the freedom to walk around. TurkDeck tackles this problem by orchestrating a group of human actuators to reconfigure a set of passive props on the fly while the user is progressing in the virtual environment. TurkDeck schedules human actuators by their distances from the user, and instructs them to reconfigure the props to the right place on the right time using laser projection and voice output. Our studies in Haptic Turk and TurkDeck showed that human actuators enjoyed the experience but not as much as users. To eliminate the need of dedicated human actuators, Mutual Turk makes everyone a user by exchanging mechanical actuation between two or more users. Mutual Turk's main functionality is that it orchestrates the users so as to actuate props at just the right moment and with just the right force to produce the correct feedback in each other's experience. Finally, we further eliminate the need of another user, making human actuation applicable to single-user experiences. iTurk makes the user constantly reconfigure and animate otherwise passive props. This allows iTurk to provide virtual worlds with constantly varying or even animated haptic effects, even though the only animate entity present in the system is the user. Our demo experience features one example each of iTurk's two main types of props, i.e., reconfigurable props (the foldable board from TurkDeck) and animated props (the pendulum). We conclude this dissertation by summarizing the findings of our explorations and pointing out future directions. We discuss the development of human actuation compare to traditional machine actuation, the possibility of combining human and machine actuators and interaction models that involve more human actuators.},
  language  = {en}
}
@phdthesis{Angermann2018,
  author    = {Angermann, Lisa},
  title     = {Hillslope-stream connectivity across scales},
  doi       = {10.25932/publishup-42454},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-424542},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xix, 193},
  year      = {2018},
  abstract  = {The concept of hydrologic connectivity summarizes all flow processes that link separate regions of a landscape. As such, it is a central theme in the field of catchment hydrology, with influence on neighboring disciplines such as ecology and geomorphology. It is widely acknowledged to be an important key in understanding the response behavior of a catchment and has at the same time inspired research on internal processes over a broad range of scales. From this process-hydrological point of view, hydrological connectivity is the conceptual framework to link local observations across space and scales. This is the context in which the four studies this thesis comprises of were conducted. The focus was on structures and their spatial organization as important control on preferential subsurface flow. Each experiment covered a part of the conceptualized flow path from hillslopes to the stream: soil profile, hillslope, riparian zone, and stream. For each study site, the most characteristic structures of the investigated domain and scale, such as slope deposits and peat layers were identified based on preliminary or previous investigations or literature reviews. Additionally, further structural data was collected and topographical analyses were carried out. Flow processes were observed either based on response observations (soil moisture changes or discharge patterns) or direct measurement (advective heat transport). Based on these data, the flow-relevance of the characteristic structures was evaluated, especially with regard to hillslope to stream connectivity. Results of the four studies revealed a clear relationship between characteristic spatial structures and the hydrological behavior of the catchment. Especially the spatial distribution of structures throughout the study domain and their interconnectedness were crucial for the establishment of preferential flow paths and their relevance for large-scale processes. Plot and hillslope-scale irrigation experiments showed that the macropores of a heterogeneous, skeletal soil enabled preferential flow paths at the scale of centimeters through the otherwise unsaturated soil. These flow paths connected throughout the soil column and across the hillslope and facilitated substantial amounts of vertical and lateral flow through periglacial slope deposits. In the riparian zone of the same headwater catchment, the connectivity between hillslopes and stream was controlled by topography and the dualism between characteristic subsurface structures and the geomorphological heterogeneity of the stream channel. At the small scale (1 m to 10 m) highest gains always occurred at steps along the longitudinal streambed profile, which also controlled discharge patterns at the large scale (100 m) during base flow conditions (number of steps per section). During medium and high flow conditions, however, the impact of topography and parafluvial flow through riparian zone structures prevailed and dominated the large-scale response patterns. In the streambed of a lowland river, low permeability peat layers affected the connectivity between surface water and groundwater, but also between surface water and the hyporheic zone. The crucial factor was not the permeability of the streambed itself, but rather the spatial arrangement of flow-impeding peat layers, causing increased vertical flow through narrow "windows" in contrast to predominantly lateral flow in extended areas of high hydraulic conductivity sediments. These results show that the spatial organization of structures was an important control for hydrological processes at all scales and study areas. In a final step, the observations from different scales and catchment elements were put in relation and compared. The main focus was on the theoretical analysis of the scale hierarchies of structures and processes and the direction of causal dependencies in this context. Based on the resulting hierarchical structure, a conceptual framework was developed which is capable of representing the system's complexity while allowing for adequate simplifications. The resulting concept of the parabolic scale series is based on the insight that flow processes in the terrestrial part of the catchment (soil and hillslopes) converge. This means that small-scale processes assemble and form large-scale processes and responses. Processes in the riparian zone and the streambed, however, are not well represented by the idea of convergence. Here, the large-scale catchment signal arrives and is modified by structures in the riparian zone, stream morphology, and the small-scale interactions between surface water and groundwater. Flow paths diverge and processes can better be represented by proceeding from large scales to smaller ones. The catchment-scale representation of processes and structures is thus the conceptual link between terrestrial hillslope processes and processes in the riparian corridor.},
  language  = {en}
}
@phdthesis{Sapegin2018,
  author    = {Sapegin, Andrey},
  title     = {High-Speed Security Log Analytics Using Hybrid Outlier Detection},
  doi       = {10.25932/publishup-42611},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-426118},
  school      = {Universit{\"a}t Potsdam},
  pages     = {162},
  year      = {2018},
  abstract  = {The rapid development and integration of Information Technologies over the last decades influenced all areas of our life, including the business world. Yet not only the modern enterprises become digitalised, but also security and criminal threats move into the digital sphere. To withstand these threats, modern companies must be aware of all activities within their computer networks. The keystone for such continuous security monitoring is a Security Information and Event Management (SIEM) system that collects and processes all security-related log messages from the entire enterprise network. However, digital transformations and technologies, such as network virtualisation and widespread usage of mobile communications, lead to a constantly increasing number of monitored devices and systems. As a result, the amount of data that has to be processed by a SIEM system is increasing rapidly. Besides that, in-depth security analysis of the captured data requires the application of rather sophisticated outlier detection algorithms that have a high computational complexity. Existing outlier detection methods often suffer from performance issues and are not directly applicable for high-speed and high-volume analysis of heterogeneous security-related events, which becomes a major challenge for modern SIEM systems nowadays. This thesis provides a number of solutions for the mentioned challenges. First, it proposes a new SIEM system architecture for high-speed processing of security events, implementing parallel, in-memory and in-database processing principles. The proposed architecture also utilises the most efficient log format for high-speed data normalisation. Next, the thesis offers several novel high-speed outlier detection methods, including generic Hybrid Outlier Detection that can efficiently be used for Big Data analysis. Finally, the special User Behaviour Outlier Detection is proposed for better threat detection and analysis of particular user behaviour cases. The proposed architecture and methods were evaluated in terms of both performance and accuracy, as well as compared with classical architecture and existing algorithms. These evaluations were performed on multiple data sets, including simulated data, well-known public intrusion detection data set, and real data from the large multinational enterprise. The evaluation results have proved the high performance and efficacy of the developed methods. All concepts proposed in this thesis were integrated into the prototype of the SIEM system, capable of high-speed analysis of Big Security Data, which makes this integrated SIEM platform highly relevant for modern enterprise security applications.},
  language  = {en}
}
@phdthesis{Haendel2018,
  author    = {H{\"a}ndel, Annabel},
  title     = {Ground-motion model selection and adjustment for seismic hazard analysis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418123},
  school      = {Universit{\"a}t Potsdam},
  pages     = {122},
  year      = {2018},
  abstract  = {Erdbeben k{\"o}nnen starke Bodenbewegungen erzeugen und es ist wichtig, diese in einer seismischen Gef{\"a}hrdungsanalyse korrekt vorherzusagen. {\"U}blicherweise werden dazu empirisch ermittelte Bodenbewegungsmodelle (GMPE) in einem logischen Baum zusammengef{\"u}gt. Wenn jedoch die Bodenbewegung in einem Gebiet mit geringer Seismizit{\"a}t bestimmen werden soll, dann fehlen in der Regel die Daten, um regionsspezifische GMPEs zu entwickeln. In diesen F{\"a}llen ist es notwendig, auf Modelle aus anderen Gebieten mit guter Datengrundlage zur{\"u}ckzugreifen und diese an die Zielregion anzupassen. Zur korrekten Anpassung werden seismologische Informationen aus der Zielregion wie beispielsweise die standortspezifische D{\"a}mpfung kappa0 ben{\"o}tigt. Diese Parameter lassen sich jedoch ebenfalls nur unzuverl{\"a}ssig bestimmen, wenn die Datengrundlage schlecht ist. In meiner Dissertation besch{\"a}ftige ich mich daher mit der Auswahl von GMPEs f{\"u}r den logischen Baum beziehungsweise deren Anpassung an Regionen mit geringer Seismizit{\"a}t. Ich folge dabei zwei verschiedenen Strategien. Im ersten Ansatz geht es um das Aufstellen eines logischen Baumes, falls kein regionsspezifisches Modell vorhanden ist. Ich stelle eine Methode vor, in der mehrere regionsfremde Modelle zu einem Mixmodell zusammengef{\"u}gt werden. Die Modelle werden dabei je nach ihrer Eignung gewichtet und die Gewichte mittels der wenigen verf{\"u}gbaren Daten aus der Zielregion ermittelt. Ein solches Mixmodell kann als sogenanntes 'Backbone'-Modell verwendet werden, welches in der Lage ist, mittlere Bodenbewegungen in der Zielregion korrekt vorherzusagen. Ich teste diesen Ansatz f{\"u}r Nordchile und acht GMPEs, die f{\"u}r verschiedene Subduktionszonen auf der Welt entwickelt wurden. Die Resultate zeigen, dass das Mixmodell bessere Ergebnisse liefert als die einzelnen GMPEs, die zu seiner Erzeugung genutzt wurden. Es ist außerdem ebenso gut in der Vorhersage von Bodenbewegungen wie ein Regressionsmodell, welches extra f{\"u}r Nordchile entwickelt wurde. Im zweiten Ansatz besch{\"a}ftige ich mich mit der Bestimmung der standortspezifischen D{\"a}mpfung kappa0. kappa0 ist einer der wichtigsten Parameter zur Anpassung eines GMPEs an eine andere Region. Mein Ziel ist es, kappa0 aus seismischer Bodenunruhe anstelle von Erdbeben zu ermitteln, da diese kontinuierlich aufgezeichnet wird. Mithilfe von Interferometrie kann die Geschwindigkeit und D{\"a}mpfung von seismischen Wellen im Untergrund bestimmt werden. Dazu werden lange Aufzeichnungsreihen seismischer Bodenunruhe entweder kreuzkorreliert oder entfaltet (Dekonvolution). Die Bestimmung der D{\"a}mpfung aus Bodenunruhe bei Frequenzen {\"u}ber 1 Hz und in geringen Tiefen ist jedoch nicht trivial. Ich zeige in meiner Dissertation die Ergebnisse von zwei Studien. In der ersten Studie wird die D{\"a}mpfung von Love-Wellen zwischen 1-4 Hz f{\"u}r ein kleines Testarray in Griechenland ermittelt. In der zweiten Studie verwende ich die Daten einer Bohrloch und einer Oberfl{\"a}chenstation aus dem Vogtland, um die D{\"a}mpfung von S-Wellen zwischen 5-15 Hz zu bestimmen. Diese beiden Studien stellen jedoch nur den Ausgangspunkt f{\"u}r zuk{\"u}nftige Untersuchungen dar, in denen kappa0 direkt aus der seismischer Bodenunruhe hergeleitet werden soll.},
  language  = {en}
}
@phdthesis{Strunk2018,
  author    = {Strunk, David},
  title     = {Gewinnung phenolischer Komponenten aus dem Birkenstamm als Rohstoffquelle f{\"u}r die Synthese eines neuen substituierten Phenylmethacrylats und dessen Polymerisation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-409228},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VIII, 157},
  year      = {2018},
  abstract  = {In der vorliegenden Arbeit werden Wege zur Gewinnung verschiedener phenolischer Substanzen wie Lignin, Diarylheptanoide und 4-(3-Oxobutyl)phenol (Himbeerketon) aus dem Stamm der H{\"a}ngebirke (Betula pendula) aufgezeigt. Durch Methacrylierung des 4-(3-Oxobutyl)phenols wurde ein Monomer erzeugt, welches mittels freier radikalischer Masse- und L{\"o}sungspolymerisation, sowie enzymatischer Polymerisation polymerisiert werden kann. Eine erste Isolierung von Bestandteilen wurde durch Extraktion von Innenholz bzw. Rinde mit Methanol erzielt. Die in Methanol unl{\"o}slichen Bestandteile des Innenholzes und der Rinde wurden anschließend mit ausgew{\"a}hlten ionischen Fl{\"u}ssigkeiten extrahiert. Es wurde ein Verfahren zum selektiven Trennen der mit diesen ionischen Fl{\"u}ssigkeiten extrahierten Bestandteile in Cellulose, Hemicellulose, Lignin und mit Ethylacetat extrahierbare Bestandteile entwickelt. Hierdurch war es m{\"o}glich, sowohl die verwendeten ionischen Fl{\"u}ssigkeiten als auch das Innenholz und die Rinde hinsichtlich ihres Extraktionsverhaltens miteinander zu vergleichen. Ferner wurden verschiedene Strategien aufgezeigt, um insgesamt drei Spezies an Diarylheptanoiden aus dem methanolischen Extrakt der Rinde zu isolieren. Eines der gefundenen Diarylheptanoide (5 Hydroxy-1,7-bis(4-hydroxyphenyl)-3-heptanon) wurde via Retroaldolreaktion in 4 (3 Oxobutyl)phenol (Himbeerketon) und 3 (4 Hydroxyphenyl)propanal gespalten. Es wurde die Verwendung des 4-(3-Oxobutyl)phenol als Monomerbestandteil untersucht. Hierf{\"u}r wurde 4-(3-Oxobutyl)phenylmethacrylat synthetisiert und Wege zur Reinigung mittels S{\"a}ulenchromatographie und Umkristallisation aufgezeigt. Anschließend wurde Poly(4-(3-oxobutyl)phenylmethacrylat) (PObMA) und Polybenzylmethacrylats (PBzMA) aus Massen- und L{\"o}sungspolymerisation hergestellt. Die Ausbeuten an PObpMA im Vergleich zum PBzMA liegen bei gleichen Reaktionsbedingungen auf gleichem Niveau. Im Kontrast hierzu ist der Polymerisationsgrad aus freier radikalischer Polymerisation in Masse des PObpMA im Vergleich zum PBzMA um den Faktor 3,7 gr{\"o}ßer. Die Glas{\"u}bergangstemperaturen des PObpMA liegen bei gleichen Reaktionsbedingungen sowohl bei freier radikalischer Polymerisation in Masse, als auch bei L{\"o}sungspolymerisation {\"u}ber denen des PBzMA. Dar{\"u}ber hinaus wurde die Polymerisation von 4-(3-Oxobutyl)phenylmethacrylat und Benzylmethacrylat mit einem Initiatorsystem bestehend aus Meerrettichperoxidase, Acetylaceton und Wasserstoffperoxid bei Raumtemperatur beschrieben. Die mit enzymatischem Initiatorsystem erzeugten Produkte zeigten starke {\"U}bereinstimmung mit Produkten aus L{\"o}sungspolymerisationen, welche mit Azobis(isobutyronitril) initiiert wurden.},
  language  = {de}
}
@phdthesis{Stoll2018,
  author    = {Stoll, Josefine},
  title     = {Gesundheitsmonitoring im Langstreckenmotorsport},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420880},
  school      = {Universit{\"a}t Potsdam},
  pages     = {117},
  year      = {2018},
  abstract  = {Professionelle GT Langstreckenmotorsportler (Rennfahrer) m{\"u}ssen den hohen motorischen und kognitiven Anspr{\"u}chen ohne Verlust der Performance w{\"a}hrend eines Rennens endgegenwirken k{\"o}nnen. Sie m{\"u}ssen stets, bei hoher Geschwindigkeit fokussiert und konzentriert auf ihr Auto, die Rennstrecke und ihre Gegner reagieren k{\"o}nnen. Dar{\"u}ber hinaus sind Rennfahrer zus{\"a}tzlich durch die notwendige Kommunikation im Auto mit den Ingenieuren und Mechanikern in der Boxengasse gefordert. Daten {\"u}ber die tats{\"a}chliche Beanspruchung und h{\"a}ufig auftretende Beschwerden und/oder Verletzung von Profiathleten liegen kaum vor. F{\"u}r eine m{\"o}glichst gute Performance im Auto w{\"a}hrend eines Rennens ist es notwendige neben der k{\"o}rperlichen Beanspruchung auch die h{\"a}ufigen Krankheitsbilder zu kennen. Auf Basis dessen kann eine optimale Pr{\"a}vention oder notwendige Therapie zur m{\"o}glichst schnellen Reintegration in den Sport abgeleitet und entwickelt werden. Die vorliegende Arbeit befasst sich durch ein regelm{\"a}ßiges Gesundheitsmonitoring mit der Erfassung h{\"a}ufiger Beschwerden und oder Verletzungen im GT Langestreckenmotorsport zur Ableitung eines pr{\"a}ventiven (trainingstherapeutischen) und therapeutischen Konzeptes. Dar{\"u}ber hinaus, soll {\"u}ber die Einsch{\"a}tzung der k{\"o}rperlichen Leistungsf{\"a}higkeit der Athleten, auf Basis der Beanspruchung im Rennfahrzeug ein m{\"o}gliches Trainingskonzept in Abh{\"a}ngigkeit der Saison entwickelt werden. Insgesamt wurden {\"u}ber 15 Jahre (2003-2017) 37 m{\"a}nnliche Athleten aus dem GT Langstreckenmotorsport 353mal im Rahmen eines Gesundheitsmonitorings untersucht. Dabei wurden Athleten maximal 14 Jahre und mindestens 1 Jahr sportmedizinische betreut. Diese 2x im Jahr stattfindende Untersuchung beinhaltete im Wesentlichen eine sportmedizinische Untersuchung zur Einsch{\"a}tzung der Tauglichkeit f{\"u}r den Sport und die Erfassung der k{\"o}rperlichen Leistungsf{\"a}higkeit. {\"U}ber das Gesundheitsmonitoring hinaus erfolgte die Betreuung zus{\"a}tzlich an der Rennstrecke zur weiteren Erfassung der Beschwerden, Erkrankungen und Verletzungen der Athleten w{\"a}hrend ihrer sportartspezifischen Belastung. Zusammengefasst zeigen die Athleten geringe Pr{\"a}valenzen und Inzidenzen der Krankheitsbilder bzw. Beschwerden. Ein Unterschied der Pr{\"a}valenzen zeigt sich zwischen den Gesundheitsuntersuchungen und der Betreuung an der Rennstrecke. Die h{\"a}ufigsten Beschwerdebilder zeigen sich aus Orthop{\"a}die und Innerer Medizin. So sind Infekte der oberen Atemwege sowie Allergien neben Beschwerden der unteren Extremit{\"a}t und der Wirbels{\"a}ule am h{\"a}ufigsten. Demzufolge werden vorrangig physio- und trainingstherapeutische Konsequenzen abgeleitet. Eine medikament{\"o}se Therapie erfolgt im Wesentlichen w{\"a}hrend der Rennbetreuung. Zur Reduktion der orthop{\"a}dischen und internistischen Beschwerden sollten pr{\"a}ventive Maßnahmen mehr betont werden. Die k{\"o}rperliche Leistungsf{\"a}higkeit zeigt im Wesentlichen {\"u}ber die Untersuchungsjahre eine stabile Performance f{\"u}r die Ausdauer-, Kraft und sensomotorische Leistungsf{\"a}higkeit. Die Ausdauerleistungsf{\"a}higkeit kann in Abh{\"a}ngigkeit der Sportartspezifik mit einer guten bis sehr guten Auspr{\"a}gung definiert werden. Die Kraftleistungsf{\"a}higkeit und die sensomotorische Leistungsf{\"a}higkeit lassen sportartspezifische Unterschiede zu und sollte k{\"o}rpergewichtsbezogen betrachtet werden. Ein sportmedizinisches und trainingstherapeutisches Konzept m{\"u}sste demnach eine regelm{\"a}ßige {\"a}rztlich-medizinische Untersuchung mit dem Fokus der Orthop{\"a}die, Inneren Medizin und Hals- Nasen-Ohren-Kunde beinhalten. Dar{\"u}ber hinaus sollte eine regelm{\"a}ßige Erfassung der k{\"o}rperlichen Leistungsf{\"a}higkeit zur m{\"o}glichst effektiven Ableitung von Trainingsinhalten oder Pr{\"a}ventionsmaßnahmen ber{\"u}cksichtig werden. Auf Grundlage der hohen Reiset{\"a}tigkeit und der ganzj{\"a}hrigen Saison k{\"o}nnte ein 1-2x j{\"a}hrlich stattfindendes Trainingslager, im Sinne eines Grundlagen- und Aufbautrainings zur Optimierung der Leistungsf{\"a}higkeit beitragen, das Konzept komplementieren. Zudem scheint eine {\"a}rztliche Rennbetreuung notwendig.},
  language  = {de}
}
@phdthesis{Beck2018,
  author    = {Beck, Christoph},
  title     = {Geschichtsphilosophie als Provokation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-410977},
  school      = {Universit{\"a}t Potsdam},
  pages     = {316},
  year      = {2018},
  abstract  = {In einer verschr{\"a}nkten Lekt{\"u}re von Curtius, Auerbach und Bachtin macht die Dissertation sichtbar, wie die Autoren mit ihren Arbeiten zur europ{\"a}ischen Literaturgeschichte nach einer ethischen Orientierung in der Krise der Moderne suchen. Ihr Konzept einer philologisch fundierten Geschichtsphilosophie in praktischer Absicht wird sowohl kultur- und theoriegeschichtlich aufbereitet, als auch anhand detaillierter Textanalysen nachvollzogen. Der Blick auf den geschichtsphilosophischen Aspekt ihrer Forschungsarbeit erweist sich hierbei nicht nur insoweit als fruchtbar, als er sich als Schl{\"u}ssel offenbart, philologische Mikrologie und breite Zusammenschau sowie ideengeschichtliche und gesellschaftliche Entwicklungen zu verkn{\"u}pfen. Ihr Ansatz offenbart sich auch als wesentlich differenzierter, als es die g{\"a}ngigen Vorbehalte gegen{\"u}ber der Geschichtsphilosophie vermuten lassen. Die Untersuchung erweitert aus diesem Grund den methodischen Diskurshorizont, indem sie die M{\"o}glichkeiten einer kritischen Geschichtsphilosophie f{\"u}r gegenw{\"a}rtige Fragen der Literaturgeschichte neu justiert. Dies geschieht {\"u}ber den Zugang so unterschiedlicher Rezeptionen wie der von Anselm Haverkamp, Edward Said, Terry Eagleton und Homi Bhabha, die einen Diskussionsraum er{\"o}ffnen, welcher den eigenen historischen Standpunkt der Dissertation im Kontext von Postmoderne und Postkolonialismus reflektiert.},
  language  = {de}
}
@phdthesis{Scholta2018,
  author    = {Scholta, Tobias},
  title     = {Georg Schneider und die {\"a}rztliche Selbstverwaltung in Brandenburg zwischen Deutschem Kaiserreich und Sowjetischer Besatzungszone},
  doi       = {10.25932/publishup-43020},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-430209},
  school      = {Universit{\"a}t Potsdam},
  pages     = {298},
  year      = {2018},
  abstract  = {Der am 15. Juni 1875 in Frankfurt (Oder) geborene und langj{\"a}hrig in seiner Wahlheimat Potsdam praktizierende Allgemeinmediziner Georg Otto Schneider war einer der bedeutendsten {\"a}rztlichen Standesvertreter der ersten H{\"a}lfte des 20. Jahrhunderts. Eng verkn{\"u}pft mit seinem Namen sind eine geradlinige, liberale Berufspolitik sowie die Entfaltung und der Erhalt beruflicher Selbstverwaltung in der brandenburgischen und gesamtdeutschen {\"A}rzteschaft. Als f{\"u}hrendes Mitglied in mehreren provinzialen und reichsweiten Verb{\"a}nden engagierte sich Schneider {\"u}ber vier historische Epochen stets im Sinne einer freien Aus{\"u}bung und autonomen Verwaltung des Arztberufes. Im Deutschen Kaiserreich war Schneiders standespolitisches Handeln zun{\"a}chst noch regional begrenzt. 1912 initiierte er die Errichtung eines Schutzverbandes f{\"u}r die {\"A}rzte des Bezirks Potsdam, dem er {\"u}ber zehn Jahre vorsaß. In der Weimarer Republik stieg Schneider sodann zu einer Schl{\"u}sselfigur der Gesundheits- und {\"a}rztlichen Berufspolitik auf. 1920 belebte er den {\"A}rzteverband f{\"u}r die Provinz Brandenburg, ab 1928 leitete er dazu in Personalunion die brandenburgische {\"A}rztekammer. Bereits zwei Jahre zuvor hatte er die Gesch{\"a}ftsf{\"u}hrung des Deutschen {\"A}rztevereinsbundes {\"u}bernommen. Infolge der Macht{\"u}bernahme der Nationalsozialisten schied Schneider bis Mitte 1934 aus allen {\"A}mtern aus, seine Bem{\"u}hungen f{\"u}r den Erhalt der Berufsautonomie waren vergebens. Anders sah es zun{\"a}chst nach Ende des Zweiten Weltkriegs aus. In der Sowjetischen Besatzungszone saß Schneider der Fachgruppe {\"A}rzte im Freien Deutschen Gewerkschaftsbund Brandenburg vor und verteidigte die M{\"o}glichkeiten der selbstst{\"a}ndigen Berufsverwaltung. Zudem war er von 1946 an bis zu seinem Tod am 26. Oktober 1949 Fraktionsvorsitzender der Liberal-Demokratischen Partei im brandenburgischen Landtag. Vor dem Hintergrund des Lebens und Wirkens Georg Schneiders untersucht die Dissertation Kontinuit{\"a}ten und Br{\"u}che im {\"a}rztlichen Organisationswesen, ausgehend vom Deutschen Kaiserreich {\"u}ber die Weimarer Epoche und den Nationalsozialismus bis hin zur Zeit der sowjetischen Besatzung. Die Arbeit stellt die Auswirkungen der jeweiligen politischen, sozio{\"o}konomischen und gesellschaftlichen Entwicklungen auf den {\"A}rztestand und die entsprechenden Reaktionen der {\"a}rztlichen Berufsvertreter, allen voran Georg Schneiders, gegen{\"u}ber. Dabei hinterfragt sie, inwiefern sich die {\"a}rztlichen Organisationsstrukturen dem jeweiligen System anpassten und welchen Einfluss Schneider als einzelne Person in den gr{\"o}ßeren Institutionen entfalten konnte.},
  language  = {de}
}
@phdthesis{Bertz2018,
  author    = {Bertz, Martin},
  title     = {Funktion von Selenoproteinen  w{\"a}hrend der kolorektalen Karzinogenese},
  doi       = {10.25932/publishup-42780},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427808},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VII, 109},
  year      = {2018},
  abstract  = {Kolorektalkrebs (CRC) ist die dritth{\"a}ufigste Tumorerkrankung weltweit. Neben dem Alter spielt auch die Ern{\"a}hrung eine wichtige Rolle bei der Entstehung der Krankheit. Eine vermutlich krebspr{\"a}ventive Wirkung wird dabei dem Spurenelement Selen zugeschrieben, das fast ausschließlich {\"u}ber Lebensmittel aufgenommen wird. So h{\"a}ngt beispielsweise ein niedriger Selenstatus mit dem Risiko, im Laufe des Lebens an CRC zu erkranken, zusammen. Seine Funktionen vermittelt Selen dabei {\"u}berwiegend durch Selenoproteine, in denen es in Form von Selenocystein eingebaut wird. Zu den bisher am besten untersuchten Selenoproteinen mit m{\"o}glicher Funktion w{\"a}hrend CRC z{\"a}hlen die Glutathionperoxidasen (GPXen). Die Mitglieder dieser Familie tragen aufgrund ihrer Hydroperoxid-reduzierenden Eigenschaften entscheidend zum Schutz der Zellen vor oxidativem Stress bei. Dies kann je nach Art und Stadium des Tumors entweder krebshemmend oder -f{\"o}rdernd wirken, da auch transformierte Zellen von dieser Schutzfunktion profitieren. In dieser Arbeit wurde die GPX2 in HT29-Darmkrebszellen mithilfe stabil-transfizierter shRNA herunterreguliert, um die Funktion des Enzyms vor allem in Hinblick auf regulierte Signalwege zu untersuchen. Ein Knockdowns (KD) der strukturell {\"a}hnlichen GPX1 kam ebenfalls zum Einsatz, um gezielt Isoform-spezifische Funktionen unterscheiden zu k{\"o}nnen. Anhand eines PCR-Arrays wurden Signalwege identifiziert, die auf einen Einfluss der beiden Proteine im Zellwachstum hindeuteten. Anschließende Untersuchungen ließen auf einen verminderten Differenzierungsstatus in den GPX1- und GPX2-KDs aufgrund einer geringeren Aktivit{\"a}t der Alkalischen Phosphatase schließen. Zudem war die Zellviabilit{\"a}t im Neutralrot-Assay (NRU) bei Fehlen der GPX1 bzw. GPX2 im Vergleich zur Kontrolle reduziert. Die Ergebnisse des PCR-Arrays, und speziell f{\"u}r die GPX2 fr{\"u}here Untersuchungen der Arbeitsgruppe, wiesen weiterhin auf eine Rolle der beiden Proteine in der entz{\"u}ndungsgetriebenen Karzinogenese hin. Daher wurden auch m{\"o}gliche Interaktionen mit dem NFκB-Signalweg analysiert. Eine Stimulation der Zellen mit dem proinflammatorischen Zytokin IL1β ging mit einer verst{\"a}rkten Aktivierung der MAP-Kinasen ERK1/2 in den Zellen mit GPX1- bzw. GPX2-KD einher. Die gleichzeitige Behandlung mit dem Antioxidans NAC f{\"u}hrte nicht zur R{\"u}cknahme der Effekte in den KDs, sodass m{\"o}glicherweise nicht nur die antioxidativen Eigenschaften der Enzyme bei der Interaktion mit diesen Signalwegsproteinen relevant sind. Weiterhin wurden Analysen zum Substratspektrum der GPX2 in HCT116-Zellen mit einer {\"U}berexpression des Proteins durchgef{\"u}hrt. Dabei zeigte sich mittels NRU-Assay und DNA-Laddering, dass die GPX2 besonders vor den proapoptotischen Effekten einer Behandlung mit den Lipidhydroperoxiden HPODE und HPETE sch{\"u}tzt. Im Gegensatz zur GPX2 l{\"a}sst sich Selenoprotein H (SELENOH) st{\"a}rker durch die aliment{\"a}re Selenzufuhr beeinflussen. Einer m{\"o}glichen Nutzung als Biomarker oder gar als Ansatzpunkt bei der Pr{\"a}vention bzw. Behandlung von CRC steht allerdings unvollst{\"a}ndiges Wissen {\"u}ber die Funktion des Proteins gegen{\"u}ber. Zur genaueren Charakterisierung von SELENOH wurden daher stabil-transfizierte KD-Klone in HT29- und Caco2-Zellen hergestellt und zun{\"a}chst auf ihre Tumorigenit{\"a}t untersucht. Zellen mit SELENOH-KD bildeten mehr und gr{\"o}ßere Kolonien im Soft Agar und zeigten ein erh{\"o}htes Proliferations- und Migrationspotenzial im Vergleich zur Kontrolle. Ein Xenograft in Nacktm{\"a}usen resultierte zudem in einer st{\"a}rkeren Tumorbildung nach Injektion von KD-Zellen. Untersuchungen zur Beteiligung von SELENOH an der Zellzyklusregulation deuten auf eine hemmende Rolle des Proteins in der G1/S-Phase hin. Die weiterhin beobachtete Hochregulation von SELENOH in humanen Adenokarzinomen und pr{\"a}kanzer{\"o}sem Mausgewebe l{\"a}sst sich m{\"o}glicherweise mit der postulierten Schutzfunktion vor oxidativen Zell- und DNA-Sch{\"a}den erkl{\"a}ren. In gesunden Darmepithelzellen war das Protein vorrangig am Kryptengrund lokalisiert, was zu einer potenziellen Rolle w{\"a}hrend der gastrointestinalen Differenzierung passt.},
  language  = {de}
}
@phdthesis{Walther2018,
  author    = {Walther, Sebastian},
  title     = {Funktionalisierung von {\"O}ls{\"a}uremethylester und Alkydharzen f{\"u}r die photoinduzierte radikalische Polymerisation im UV Bereich},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421467},
  school      = {Universit{\"a}t Potsdam},
  pages     = {136},
  year      = {2018},
  abstract  = {Die vorliegende Arbeit behandelt die Synthese und Charakterisierung von funktionalisierten Alkydharzen und die photoinduzierte Polymerisation dieser unter Einsatz einer Quecksilberdampflampe oder einer UV LED mit unterschiedlicher Lichtintensit{\"a}t. Der Fokus dieser Arbeit bestand in der gezielten Substitution der internalen Doppelbindungen der Fetts{\"a}ureester durch reaktivere Gruppen, wie Acrylate oder Methacrylate, welche f{\"u}r Alkydharze in dieser Form so in der Literatur nicht beschrieben sind. Untersuchungen des Polymerisationsverhaltens dieser funktionalisierten Harze wurden mit der Photo DSC durchgef{\"u}hrt, wobei Bis - (4 - methoxybenzoyl) diethylgermanium als Photoinitiator diente. Die Ergebnisse haben gezeigt, dass die Harze radikalisch polymerisiert werden k{\"o}nnen und eine geringere Abh{\"a}ngigkeit von der Umgebungsatmosph{\"a}re (Luftsauerstoff bzw. Stickstoff) vorliegt. Dies ist so in der Literatur f{\"u}r funktionalisierte Alkydharze nicht bekannt. Abmischungen von unterschiedlichen Monomeren und funktionalisierten Harzen bewirkten eine Steigerung der Viskosit{\"a}t sowie eine Verringerung der Sauerstoffinhibierung im Zuge der photoinduzierten Polymerisation unter Luftsauerstoff f{\"u}r die Quecksilberdampflampe und der UV LED. Zur Untersuchung der sauerstoffinhibierenden Wirkung der Harze sind Synthesen unterschiedlicher, funktionalisierter {\"O}ls{\"a}uremethylester als Modellsubstanzen durchgef{\"u}hrt worden. Ein verbessertes Polymerisationsverhalten und eine geringe Abh{\"a}ngigkeit von der Umgebungsatmosph{\"a}re konnte f{\"u}r die Modelle nachgewiesen werden. Zur Aufkl{\"a}rung des verbesserten Polymerisationsverhaltens sind gezielt Substituenten (Imidazol, Brom, Alkohol, Acetat) in den funktionalisierten {\"O}ls{\"a}uremethylester eingebaut worden, um den Einfluss dieser aufzuzeigen. Im Rahmen dieser Synthesen sind neuartige Strukturen synthetisiert worden, welche so in der Literatur nicht beschrieben sind. Die Gegen{\"u}berstellung der Polymerisationszeit, der Umsatz der (Meth-)Acrylatgruppen sowie die Zeit zum Erreichen der maximalen Polymerisationsgeschwindigkeit unter Verwendung von unterschiedlichen UV Lichtquellen hat einen Einfluss der Substituenten auf das Polymerisationsverhalten gezeigt.},
  language  = {de}
}
@phdthesis{Lama2018,
  author    = {Lama, Sandy M. G.},
  title     = {Functionalization of Porous Carbon Materials with Heteroatoms and Application as Supports in Industrial Heterogeneous Catalysis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-415797},
  school      = {Universit{\"a}t Potsdam},
  pages     = {124},
  year      = {2018},
  abstract  = {Due to a challenging population growth and environmental changes, a need for new routes to provide required chemicals for human necessities arises. An effective solution discussed in this thesis is industrial heterogeneous catalysis. The development of an advanced industrial heterogeneous catalyst is investigated herein by considering porous carbon nano-material as supports and modifying their surface chemistry structure with heteroatoms. Such modifications showed a significant influence on the performance of the catalyst and provided a deeper insight regarding the interaction between the surface structure of the catalyst and the surrounding phase. This thesis contributes to the few present studies about heteroatoms effect on the catalyst performance and emphasizes on the importance of understanding surface structure functionalization in a catalyst in different phases (liquid and gaseous) and for different reactions (hydrogenolysis, oxidation, and hydrogenation/ polymerization). Herein, the heteroatoms utilized for the modifications are hydrogen (H), oxygen (O), and nitrogen (N). The heteroatoms effect on the metal particle size, on the polarity of the support/ the catalyst, on the catalytic performance (activity, selectivity, and stability), and on the interaction with the surrounding phase has been explored. First hierarchical porous carbon nanomaterials functionalized with heteroatoms (N) is synthesized and applied as supports for nickel nanoparticles for hydrogenolysis process of kraft lignin in liquid phase. This reaction has been performed in batch and flow reactors for three different catalysts, two of comparable hierarchical porosity, yet one is modified with N and the other is not, and a third is a prepared catalyst from a commercial carbon support. The reaction production and analyses show that the catalysts with hierarchical porosity perform catalytically much better than in presence of a commercial carbon support with lower surface area. Moreover, the modification with N-heteroatoms enhanced the catalytic performance because the heteroatom modified porous carbon material with nickel nanoparticles catalyst (Ni-NDC) performed highest among the other catalysts. In the flow reactor, Ni-NDC selectively degraded the ether bonds (β-O-4) in kraft lignin with an activity of 2.2 x10^-4 mg lignin mg Ni-1 s-1 for 50 h at 350°C and 3.5 mL min-1 flow, providing ~99 \% conversion to shorter chained chemicals (mainly guaiacol derivatives). Then, the functionalization of carbon surface was further studied in selective oxidation of glucose to gluconic acid using < 1 wt. \% of gold (Au) deposited on the previously-mentioned synthesized carbon (C) supports with different functionalities (Au-CGlucose, Au-CGlucose-H, Au-CGlucose-O, Au-CGlucoseamine). Except for Au-CGlucose-O, the other catalysts achieved full glucose conversion within 40-120 min and 100\% selectivity towards gluconic acid with a maximum activity of 1.5 molGlucose molAu-1 s-1 in an aqueous phase at 45 °C and pH 9. Each heteroatom influenced the polarity of the carbon differently, affecting by that the deposition of Au on the support and thus the activity of the catalyst and its selectivity. The heteroatom effect was further investigated in a gas phase. The Fischer-Tropsch reaction was applied to convert synthetic gas (CO and H2) to short olefins and paraffins using surface-functionalized carbon nanotubes (CNTs) with heteroatoms as supports for ion (Fe) deposition in presence and absence of promoters (Na and S). The results showed the promoted Fe-CNT doped with nitrogen catalyst to be stable up to 180 h and selective to the formation of olefins (~ 47 \%) and paraffins (~6 \%) with a conversion of CO ~ 92 \% at a maximum activity of 94 *10^-5 mol CO g Fe-1 s-1. The more information given regarding this topic can open wide range of applications not only in catalysis, but in other approaches as well. In conclusion, incorporation of heteroatoms can be the next approach for an advanced industrial heterogeneous catalyst, but also for other applications (e.g. electrocatalysis, gas adsorption, or supercapacitors).},
  language  = {en}
}
@phdthesis{Przybylla2018,
  author    = {Przybylla, Mareen},
  title     = {From Embedded Systems to Physical Computing: Challenges of the "Digital World" in Secondary Computer Science Education},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418339},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvii, 277},
  year      = {2018},
  abstract  = {Physical computing covers the design and realization of interactive objects and installations and allows learners to develop concrete, tangible products of the real world, which arise from their imagination. This can be used in computer science education to provide learners with interesting and motivating access to the different topic areas of the subject in constructionist and creative learning environments. However, if at all, physical computing has so far mostly been taught in afternoon clubs or other extracurricular settings. Thus, for the majority of students so far there are no opportunities to design and create their own interactive objects in regular school lessons. Despite its increasing popularity also for schools, the topic has not yet been clearly and sufficiently characterized in the context of computer science education. The aim of this doctoral thesis therefore is to clarify physical computing from the perspective of computer science education and to adequately prepare the topic both content-wise and methodologically for secondary school teaching. For this purpose, teaching examples, activities, materials and guidelines for classroom use are developed, implemented and evaluated in schools. In the theoretical part of the thesis, first the topic is examined from a technical point of view. A structured literature analysis shows that basic concepts used in physical computing can be derived from embedded systems, which are the core of a large field of different application areas and disciplines. Typical methods of physical computing in professional settings are analyzed and, from an educational perspective, elements suitable for computer science teaching in secondary schools are extracted, e. g. tinkering and prototyping. The investigation and classification of suitable tools for school teaching show that microcontrollers and mini computers, often with extensions that greatly facilitate the handling of additional components, are particularly attractive tools for secondary education. Considering the perspectives of science, teachers, students and society, in addition to general design principles, exemplary teaching approaches for school education and suitable learning materials are developed and the design, production and evaluation of a physical computing construction kit suitable for teaching is described. In the practical part of this thesis, with "My Interactive Garden", an exemplary approach to integrate physical computing in computer science teaching is tested and evaluated in different courses and refined based on the findings in a design-based research approach. In a series of workshops on physical computing, which is based on a concept for constructionist professional development that is developed specifically for this purpose, teachers are empowered and encouraged to develop and conduct physical computing lessons suitable for their particular classroom settings. Based on their in-class experiences, a process model of physical computing teaching is derived. Interviews with those teachers illustrate that benefits of physical computing, including the tangibility of crafted objects and creativity in the classroom, outweigh possible drawbacks like longer preparation times, technical difficulties or difficult assessment. Hurdles in the classroom are identified and possible solutions discussed. Empirical investigations in the different settings reveal that "My Interactive Garden" and physical computing in general have a positive impact, among others, on learner motivation, fun and interest in class and perceived competencies. Finally, the results from all evaluations are combined to evaluate the design principles for physical computing teaching and to provide a perspective on the development of decision-making aids for physical computing activities in school education.},
  language  = {en}
}
@phdthesis{Stolley2018,
  author    = {Stolley, Florian},
  title     = {Four essays on altruism and compliance},
  doi       = {10.25932/publishup-42801},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-428013},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ix, 129},
  year      = {2018},
  abstract  = {There are numerous situations in which people ask for something or make a request, e.g. asking a favor, asking for help or requesting compliance with specific norms. For this reason, how to ask for something in order to increase people's willingness to fulfill such requests is one of the most important question for many people working in various different fields of responsibility such as charitable giving, marketing, management or policy making. This dissertation consists of four chapters that deal with the effects of small changes in the decision-making environment on altruistic decision-making and compliance behavior. Most notably, written communication as an influencing factor is the focus of the first three chapters. The starting point was the question how to devise a request in order to maximize its chance of success (Chapter 1). The results of the first chapter originate the ideas for the second and third chapter. Chapter 2 analyzes how communication by a neutral third-party, i.e. a text from the experimenters that either reminds potential benefactors of their responsibility or highlights their freedom of choice, affects altruistic decision-making. Chapter 3 elaborates on the effect of thanking people in advance when asking them for help. While being not as closely related to the other chapters as the three first ones are, the fourth chapter deals as well with the question how compliance (here: compliance with norms and rules) is affected by subtle manipulations of the environment in which decisions are made. This chapter analyzes the effect of default settings in a tax return on tax compliance. In order to study the research questions outlined above, controlled experiments were conducted. Chapter 1, which analyzes the effect of text messages on the decision to give something to another person, employs a mini-dictator game. The recipient sends a free-form text message to the dictator before the latter makes a binary decision whether or not to give part of her or his endowment to the recipient. We find that putting effort into the message by writing a long note without spelling mistakes increases dictators' willingness to give. Moreover, writing in a humorous way and mentioning reasons why the money is needed pays off. Furthermore, men and women seem to react differently to some message categories. Only men react positively to efficiency arguments, while only women react to messages that emphasize the dictator's power and responsibility. Building on this last result, Chapter 2 attempts to disentangle the effect of reminding potential benefactors of their responsibility for the potential beneficiary and the effect of highlighting their decision power and freedom of choice on altruistic decision-making by studying the effects of two different texts on giving in a dictator game. We find that only men react positively to a text that stresses their responsibility for the recipient by giving more to her or him, whereas only women seem to react positively to a text that emphasizes their decision power and freedom of choice. Chapter 3 focuses on the compliance with a request. In the experiment, participants are asked to provide a detailed answer to an open question. Compliance is measured by the effort participants spend on answering the question. The treatment variable is whether or not they see the text "thanks in advance." We find that participants react negatively by putting less effort into complying with the request in response to the phrase "thanks in advance." Chapter 4 studies the effect of prefilled tax returns with mostly inaccurate default values on tax compliance. In a laboratory experiment, participants earn income by performing a real-effort task and must subsequently file a tax return for three consecutive rounds. In the main treatment, the tax return is prefilled with a default value, resulting from participants' own performance in previous rounds, which varies in its relative size. The results suggest that there is no lasting effect of a default value on tax honesty, neither for relatively low nor relatively high defaults. However, participants who face a default that is lower than their true income in the first round evade significantly and substantially more taxes in this round than participants in the control treatment without a default.},
  language  = {en}
}
@phdthesis{Stettner2018,
  author    = {Stettner, Samuel},
  title     = {Exploring the seasonality of rapid Arctic changes from space},
  doi       = {10.25932/publishup-42578},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-425783},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XIII, 132},
  year      = {2018},
  abstract  = {Arctic warming has implications for the functioning of terrestrial Arctic ecosystems, global climate and socioeconomic systems of northern communities. A research gap exists in high spatial resolution monitoring and understanding of the seasonality of permafrost degradation, spring snowmelt and vegetation phenology. This thesis explores the diversity and utility of dense TerraSAR-X (TSX) X-Band time series for monitoring ice-rich riverbank erosion, snowmelt, and phenology of Arctic vegetation at long-term study sites in the central Lena Delta, Russia and on Qikiqtaruk (Herschel Island), Canada. In the thesis the following three research questions are addressed: • Is TSX time series capable of monitoring the dynamics of rapid permafrost degradation in ice-rich permafrost on an intra-seasonal scale and can these datasets in combination with climate data identify the climatic drivers of permafrost degradation? • Can multi-pass and multi-polarized TSX time series adequately monitor seasonal snow cover and snowmelt in small Arctic catchments and how does it perform compared to optical satellite data and field-based measurements? • Do TSX time series reflect the phenology of Arctic vegetation and how does the recorded signal compare to in-situ greenness data from RGB time-lapse camera data and vegetation height from field surveys? To answer the research questions three years of TSX backscatter data from 2013 to 2015 for the Lena Delta study site and from 2015 to 2017 for the Qikiqtaruk study site were used in quantitative and qualitative analysis complimentary with optical satellite data and in-situ time-lapse imagery. The dynamics of intra-seasonal ice-rich riverbank erosion in the central Lena Delta, Russia were quantified using TSX backscatter data at 2.4 m spatial resolution in HH polarization and validated with 0.5 m spatial resolution optical satellite data and field-based time-lapse camera data. Cliff top lines were automatically extracted from TSX intensity images using threshold-based segmentation and vectorization and combined in a geoinformation system with manually digitized cliff top lines from the optical satellite data and rates of erosion extracted from time-lapse cameras. The results suggest that the cliff top eroded at a constant rate throughout the entire erosional season. Linear mixed models confirmed that erosion was coupled with air temperature and precipitation at an annual scale, seasonal fluctuations did not influence 22-day erosion rates. The results highlight the potential of HH polarized X-Band backscatter data for high temporal resolution monitoring of rapid permafrost degradation. The distinct signature of wet snow in backscatter intensity images of TSX data was exploited to generate wet snow cover extent (SCE) maps on Qikiqtaruk at high temporal resolution. TSX SCE showed high similarity to Landsat 8-derived SCE when using cross-polarized VH data. Fractional snow cover (FSC) time series were extracted from TSX and optical SCE and compared to FSC estimations from in-situ time-lapse imagery. The TSX products showed strong agreement with the in-situ data and significantly improved the temporal resolution compared to the Landsat 8 time series. The final combined FSC time series revealed two topography-dependent snowmelt patterns that corresponded to in-situ measurements. Additionally TSX was able to detect snow patches longer in the season than Landsat 8, underlining the advantage of TSX for detection of old snow. The TSX-derived snow information provided valuable insights into snowmelt dynamics on Qikiqtaruk previously not available. The sensitivity of TSX to vegetation structure associated with phenological changes was explored on Qikiqtaruk. Backscatter and coherence time series were compared to greenness data extracted from in-situ digital time-lapse cameras and detailed vegetation parameters on 30 areas of interest. Supporting previous results, vegetation height corresponded to backscatter intensity in co-polarized HH/VV at an incidence angle of 31°. The dry, tall shrub dominated ecological class showed increasing backscatter with increasing greenness when using the cross polarized VH/HH channel at 32° incidence angle. This is likely driven by volume scattering of emerging and expanding leaves. Ecological classes with more prostrate vegetation and higher bare ground contributions showed decreasing backscatter trends over the growing season in the co-polarized VV/HH channels likely a result of surface drying instead of a vegetation structure signal. The results from shrub dominated areas are promising and provide a complementary data source for high temporal monitoring of vegetation phenology. Overall this thesis demonstrates that dense time series of TSX with optical remote sensing and in-situ time-lapse data are complementary and can be used to monitor rapid and seasonal processes in Arctic landscapes at high spatial and temporal resolution.},
  language  = {en}
}
@phdthesis{Leser2018,
  author    = {Leser, Eva},
  title     = {Eta Carinae},
  doi       = {10.25932/publishup-42814},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-428141},
  school      = {Universit{\"a}t Potsdam},
  pages     = {X, 117},
  year      = {2018},
  abstract  = {Das außergew{\"o}hnliche Doppelsternsystem Eta Carinae fasziniert WissenschaftlerInnen und BeobachterInnen auf der s{\"u}dlichen Erdhalbkugel seit hunderten Jahren. Nach einem Supernova-{\"a}hnlichem Ausbruch war Eta Carinae zeitweise der hellste Stern am Nachthimmel. Heute sind durch zahlreiche Beobachtungen, von Radiowellen bis zu R{\"o}ntgenstrahlung, der Aufbau des Sternsystems und die Eigenschaften seiner Strahlung bis zu Energien von ~ 50 keV gut erforscht. Das Doppelsternsystem besteht aus zwei massiven Sternen (~ 30 und ~ 100 Sonnenmassen Gewicht) mit starken Sternwinden, {\"u}ber die sie kontinuierlich einen Teil ihrer Masse verlieren. Wenn diese Sternwinde kollidieren, entsteht auf beiden Seiten ein Kompressionsschock der das Plasma in der Kollisionszone aufheizt, was sich in R{\"o}ntgenstrahlung beobachten l{\"a}sst. Bei Energien oberhalb von ~ 50 keV ist der Ursprung der Strahlung nicht mehr thermisch: um ein Plasma auf die entsprechende Temperatur zu bringen, wird mehr mechanische Energie ben{\"o}tigt, als in den Sternwinden vorhanden. In hoch-energetischer Gamma-Strahlung ist Eta Carinae das einzige eindeutig detektierte Sternsystem seiner Art und sein Energiespektrum reicht bis zu ~ hundert GeV. Bodengebundene Gamma-Strahlungsexperimente haben in diesem Energiebereich den Vorteil von großen Detektorfl{\"a}chen. H.E.S.S. ist das einzige bodengebundene Gamma-Strahlungsexperiment auf der S{\"u}dhalbkugel und somit in der Lage, Eta Carinae in diesen Energien zu beobachten. H.E.S.S. misst Gamma-Strahlung mit Hilfe der elektromagnetischen Teilchenschauer, die sehr hoch-energetische Photonen in der Atmosph{\"a}re ausl{\"o}sen. Die gr{\"o}ßte Herausforderung der Messung von Eta Carinaes Strahlung mit H.E.S.S. ist die ultraviolette Strahlung des Carina Nebels, die zu einem Hintergrund f{\"u}hrt, der bis zu zehn mal st{\"a}rker ist als der Durchschnitt in H.E.S.S. In dieser Arbeit wird die erste Detektion eines Doppelsternsystems mit kollidierenden Sternwinden in sehr hoch-energetischer Gamma-Strahlung pr{\"a}sentiert und die Studien, die diese erm{\"o}glicht haben. Das differentielle Gamma-Strahlungsspektrum bis 700 GeV wird untersucht. Hadronische und leptonische Szenarios f{\"u}r den Ursprung der Gamma-Strahlung werden diskutiert und das hadronische Szenario wird aufgrund eines Vergleichs der K{\"u}hlzeiten bevorzugt.},
  language  = {en}
}
@phdthesis{Konon2018,
  author    = {Konon, Alexander},
  title     = {Essays on career choice under risk and ambiguity},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-416466},
  school      = {Universit{\"a}t Potsdam},
  pages     = {x, 250, xxxv},
  year      = {2018},
  abstract  = {This dissertation consists of five self-contained essays, addressing different aspects of career choices, especially the choice of entrepreneurship, under risk and ambiguity. In Chapter 2, the first essay develops an occupational choice model with boundedly rational agents, who lack information, receive noisy feedback, and are restricted in their decisions by their personality, to analyze and explain puzzling empirical evidence on entrepreneurial decision processes. In the second essay, in Chapter 3, I contribute to the literature on entrepreneurial choice by constructing a general career choice model on the basis of the assumption that outcomes are partially ambiguous. The third essay, in Chapter 4, theoretically and empirically analyzes the impact of media on career choices, where information on entrepreneurship provided by the media is treated as an informational shock affecting prior beliefs. The fourth essay, presented in Chapter 5, contains an empirical analysis of the effects of cyclical macro variables (GDP and unemployment) on innovative start-ups in Germany. In the fifth, and last, essay in Chapter 6, we examine whether information on personality is useful for advice, using the example of career advice.},
  language  = {en}
}
@phdthesis{Wulff2018,
  author    = {Wulff, Alexander},
  title     = {Essays in macroeconomics and financial market imperfections},
  doi       = {10.25932/publishup-42995},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-429956},
  school      = {Universit{\"a}t Potsdam},
  pages     = {X, 142},
  year      = {2018},
  abstract  = {This dissertation consists of four self-contained papers that deal with the implications of financial market imperfections and heterogeneity. The analysis mainly relates to the class of incomplete-markets models but covers different research topics. The first paper deals with the distributional effects of financial integration for developing countries. Based on a simple heterogeneous-agent approach, it is shown that capital owners experience large welfare losses while only workers moderately gain due to higher wages. The large welfare losses for capital owners contrast with the small average welfare gains from representative-agent economies and indicate that a strong opposition against capital market opening has to be expected. The second paper considers the puzzling observation of capital flows from poor to rich countries and the accompanying changes in domestic economic development. Motivated by the mixed results from the literature, we employ an incomplete-markets model with different types of idiosyncratic risk and borrowing constraints. Based on different scenarios, we analyze under what conditions the presence of financial market imperfections contributes to explain the empirical findings and how the conditions may change with different model assumptions. The third paper deals with the interplay of incomplete information and financial market imperfections in an incomplete-markets economy. In particular, it analyzes the impact of incomplete information about idiosyncratic income shocks on aggregate saving. The results show that the effect of incomplete information is not only quantitatively substantial but also qualitatively ambiguous and varies with the influence of the income risk and the borrowing constraint. Finally, the fourth paper analyzes the influence of different types of fiscal rules on the response of key macroeconomic variables to a government spending shock. We find that a strong temporary increase in public debt contributes to stabilizing consumption and leisure in the first periods following the change in government spending, whereas a non-debt-intensive fiscal rule leads to a faster recovery of consumption, leisure, capital and output in later periods. Regarding optimal debt policy, we find that a debt-intensive fiscal rule leads to the largest aggregate welfare benefit and that the individual welfare gain is particularly high for wealth-poor agents.},
  language  = {en}
}
@phdthesis{Grunert2018,
  author    = {Grunert, Bianca},
  title     = {Entwicklung von Markierungsreagenzien f{\"u}r die bildgebende Diagnostik},
  doi       = {10.25932/publishup-42283},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-422830},
  school      = {Universit{\"a}t Potsdam},
  pages     = {155},
  year      = {2018},
  abstract  = {Die intrazellul{\"a}re Markierung mit geeigneten Reagenzien erm{\"o}glicht ihre bildgebende Darstellung in lebenden Organismen. Dieses Verfahren (auch „Zell-Tracking" genannt) wird in der Grundlagenforschung zur Entwicklung zellul{\"a}rer Therapien, f{\"u}r die Erforschung pathologischer Prozesse, wie der Metastasierung, sowie f{\"u}r Therapiekontrollen eingesetzt. Besondere Bedeutung haben in den letzten Jahren zellul{\"a}re Therapien mit Stammzellen erlangt, da sie großes Potential bei der Regeneration von Geweben bei Krankheiten wie Morbus Parkinson oder Typ-1-Diabetes versprechen. F{\"u}r die Entwicklung einer zellul{\"a}ren Therapie sind Informationen {\"u}ber den Verbleib der applizierten Zellen in vivo (Homing-Potential), {\"u}ber ihre Zellphysiologie sowie {\"u}ber die Entstehung m{\"o}glicher Entz{\"u}ndungen notwendig. Das Ziel der vorliegenden Arbeit war daher die Synthese von Markierungsreagenzien, die nicht nur eine effiziente Zellmarkierung erm{\"o}glichen, sondern einen synergistischen Effekt hinsichtlich des modalit{\"a}ts{\"u}bergreifenden Einsatzes in den bildgebenden Verfahren MRT und Laser-Ablation(LA)-ICP-MS erlauben. Die MRT-Bildgebung erm{\"o}glicht die nicht invasive Nachverfolgung markierter Zellen in vivo und die LA-ICP-MS die anschließende ex vivo Analytik zur Darstellung der Elementverteilung (Bioimaging) in einer Biopsieprobe oder in einem Gewebeschnitt. F{\"u}r diese Zwecke wurden zwei verschiedene Markierungsreagenzien mit dem kontrastgebenden Element Gadolinium synthetisiert. Gadolinium eignet sich aufgrund seines hohen magnetischen Moments hervorragend f{\"u}r die MRT-Bildgebung und da es in Biomolek{\"u}len nicht nat{\"u}rlich vorkommt, konnten die Reagenzien gleichermaßen f{\"u}r die Zellmarkierung und das Bioimaging mit der LA-ICP-MS untersucht werden. F{\"u}r die Synthese eines makromolekularen Reagenzes wurde das kommerziell verf{\"u}gbare Dendrimer G5-PAMAM {\"u}ber bifunktionelle Linker mit dem Chelator DOTA funktionalisiert, um anschließend Gadolinium zu komplexieren. Ein zweites, nanopartikul{\"a}res Reagenz wurde {\"u}ber eine Solvothermal-Synthese erhalten, bei der Ln:GdVO4-Nanokristalle mit einer funktionellen Polyacryls{\"a}ure(PAA)-H{\"u}lle dargestellt wurden. Die Dotierung der Ln:GdVO4-PAA Nanokristalle mit verschiedenen Lanthanoiden (Ln=Eu, Tb) zeigte ihre prinzipielle Multiplexf{\"a}higkeit in der LA-ICP-MS. Beide Markierungsreagenzien zeichneten sich durch gute Biovertr{\"a}glichkeiten und r1-Relaxivit{\"a}ten aus, was zudem ihr Potential f{\"u}r Anwendungen als pr{\"a}klinische „blood-pool" MRT-Kontrastmittel belegte. Die Untersuchung der Zellmarkierung erfolgte anhand einer Tumorzelllinie und einer Stammzelllinie, wobei beide Zellarten erfolgreich intrazellul{\"a}r mit beiden Reagenzien markiert wurden. Nach der Zellmarkierung veranschaulichte die in vitro MRT-Bildgebung von Zell-Phantomen eine deutlichere Kontrastverst{\"a}rkung der Zellen nach der Markierung mit den Nanokristallen im Vergleich zum kommerziellen Kontrastmittel Magnevist®. Die hohe Effizienz der Zellmarkierung mit den Nanokristallen und die damit verbundenen hohen Signalintensit{\"a}ten in einer einzelnen Zelle erlaubten beim Bioimaging mit der LA-ICP-MS, Messungen bis zu einer Aufl{\"o}sung von 4 µm Laser Spot Size. Nach der Zellmarkierung mit den DOTA(Gd3+)-funktionalisierten G5-PAMAM Dendrimeren waren hingegen Aufnahmen mit der LA-ICP-MS nur bis zu einer Aufl{\"o}sung von 12 µm Laser Spot Size m{\"o}glich. Insgesamt waren die Ln:GdVO4-PAA Nanokristalle mit gr{\"o}ßerer Ausbeute und kosteng{\"u}nstiger herstellbar als die DOTA(Gd3+)-funktionalisierten G5-PAMAM Dendrimere und zeigten zudem eine effizientere Zellmarkierung. Die Ln:GdVO4-PAA Nanokristalle erscheinen somit f{\"u}r das Zell-Tracking als besonders vielversprechend. Darauf aufbauend wurden die Nanokristalle zur Etablierung der Antik{\"o}rper-Konjugation ausgew{\"a}hlt, was sie f{\"u}r die molekulare in vivo Bildgebung sowie f{\"u}r die Immuno-Bildgebung von Gewebeschnitten oder Biopsie-Proben mit der LA-ICP-MS anwendbar macht.},
  language  = {de}
}
@phdthesis{Schulze2018,
  author    = {Schulze, Sven},
  title     = {Entwicklung und Charakterisierung optischer Biosensorplattformen basierend auf photonischen Kristallen und Faser-Bragg-Gitter},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-422139},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xviii, 149, A-23, B-2, C-8},
  year      = {2018},
  abstract  = {In dieser Arbeit steht die Entwicklung einer Sensorplattform f{\"u}r biochemische Anwendungen, welche auf einem optischen Detektionsprinzips beruht, im Vordergrund. W{\"a}hrend der Entwicklung wurden zwei komplement{\"a}re Konzeptideen behandelt, zum einen ein Sensor, der auf photonischen Kristallen und Wellenleiterstrukturen basiert und zum anderen einen faserbasierten Sensor, der chemisch modifizierte Faser-Bragg-Gitter enth{\"a}lt. Das optische Detektionsprinzip in beiden Sensorideen ist die resultierende Brechungsindex{\"a}nderung als messbare physikochemische Kenngr{\"o}ße. Das aus der Natur bekannte Ph{\"a}nomen der photonischen Kristalle, das u. a. bei Opalen und bei Schmetterlingen zu finden ist, wurde bereits 1887 von Lord Rayleigh beschrieben. Er beschrieb die optischen Eigenschaften von periodischen mehrschichtigen Filmen, welche als vereinfachtes Modell eines eindimensionalen photonischen Kristalls verstanden werden k{\"o}nnen. Die Periodizit{\"a}t der Brechungsindex{\"a}nderung resultiert in einem optischen Filter f{\"u}r Frequenzen in einem bestimmten spektralen Bereich, weshalb dann dort keine Lichtausbreitung mehr m{\"o}glich ist. Wird dieses System aber durch eine Defektstelle in der Brechungsindexperiodizit{\"a}t gest{\"o}rt, sodass daraus zwei perfekt periodische Systeme entstehen, ist die Lichtausbreitung f{\"u}r eine bestimmte Frequenz dennoch m{\"o}glich. In der Folge resultiert daraus ein schmalbandiges Signal im Transmissionsspektrum. Die erlaubte Frequenz ist dabei u. a. abh{\"a}ngig vom Brechungsindexunterschied des periodischen Systems, d.h. Ver{\"a}nderung des Brechungsindexes einer Schicht f{\"u}hrt zu einer spektralen Verschiebung der erlaubten Frequenz, dadurch kann dieses Sensorkonzept f{\"u}r biochemische Sensorik ausgenutzt werden [1]. Diese Entwicklung des auf photonischen Kristallen basierenden Sensors war eine Kooperation mit dem Industriepartner „Nanoplus GmbH". In der Doktorarbeit wurden Simulationen und praktischen Arbeiten zur Designentwicklung des Sensors und die Arbeiten an einem ersten Modellaufbau f{\"u}r die biochemischen Anwendungen durchgef{\"u}hrt. F{\"u}r den faserbasierten Sensor wurden Faser-Bragg-Gitter in den Faserkern hineingeschrieben. Hill et al. entdeckten 1978, dass solche Gitterstrukturen genau wie photonische Kristalle als optische Filter fungieren [2]. Die Gitter bestehen dabei aus {\"A}nderungen des Brechungsindexes im Faserkern. Im Laufe der n{\"a}chsten vierzig Jahren wurden verschiedene Einschreibetechniken und Gitterstrukturen entwickelt, weshalb die Eigenschaften der jeweiligen Gitterstrukturen variieren. Eine solche Gitterstruktur sind u. a. die Faser-Bragg-Gitter, deren Gitterperiode, d. h. die Abst{\"a}nde der Brechungsindexmodifikationen, sich im Nanometer- bis Mikrometerbereich befinden. Aufgrund der kleinen Gitterperiode wird eine r{\"u}ckw{\"a}rtsf{\"u}hrende Welle im Kern f{\"u}r eine bestimmte Frequenz bzw. Wellenl{\"a}nge, der Bragg-Wellenl{\"a}nge, erzeugt. Im Endeffekt resultiert daraus ein schmalbandiges Signal sowohl im Transmissionsspektrum, als auch im Reflexionsspektrum. Die Resonanzwellenl{\"a}nge ist dabei proportional zu der Gitterperiode und dem effektiven Brechungsindex, welcher vom Brechungsindex des Kerns und des kernumgebenen Materials abh{\"a}ngig ist. Letztlich eignet sich diese Technik f{\"u}r physikochemische Sensorik. Im Rahmen dieser Arbeit wurden die Gitter mit Hilfe einer relativen neuen Herstellungsmethode in die Fasern geschrieben [3]. Anschließend stand die Entwicklung eines Biosensors im Vordergrund, wobei zun{\"a}chst ein Protokoll zum {\"A}tzen der Faser mit Flusss{\"a}ure entwickelt worden ist, dass das System sensitiv zum umgebenen Brechungsindex macht. Am Ende wurde ein Modellaufbau realisiert, indem ein Modellsystem, hier die Detektion vom C-reaktiven Protein mittels spezifischen einzelstr{\"a}ngigen DNS-Aptameren, erfolgreich getestet und quantifiziert worden ist. 1 Mandal, S.; Erickson, D. Nanoscale Optofluidic Sensor Arrays. Opt. Express 2008, 16 (3), 1623-1631. 2 Hill, K. O.; Fujii, Y.; Johnson, D. C.; Kawasaki, B. S. Photosensitivity in Optical Fiber Waveguides: Application to Reflection Filter Fabrication. Appl. Phys. Lett. 1978, 32 (10), 647-649. 3 Mart{\´i}nez, A.; Dubov, M.; Khrushchev, I.; Bennion, I. Direct Writing of Fibre Bragg Gratings by Femtosecond Laser. Electron. Lett. 2004, 40 (19), 1170.},
  language  = {de}
}
@phdthesis{Jaeger2018,
  author    = {Jaeger, David},
  title     = {Enabling Big Data security analytics for advanced network attack detection},
  doi       = {10.25932/publishup-43571},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435713},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XVII, 201, XXXIII},
  year      = {2018},
  abstract  = {The last years have shown an increasing sophistication of attacks against enterprises. Traditional security solutions like firewalls, anti-virus systems and generally Intrusion Detection Systems (IDSs) are no longer sufficient to protect an enterprise against these advanced attacks. One popular approach to tackle this issue is to collect and analyze events generated across the IT landscape of an enterprise. This task is achieved by the utilization of Security Information and Event Management (SIEM) systems. However, the majority of the currently existing SIEM solutions is not capable of handling the massive volume of data and the diversity of event representations. Even if these solutions can collect the data at a central place, they are neither able to extract all relevant information from the events nor correlate events across various sources. Hence, only rather simple attacks are detected, whereas complex attacks, consisting of multiple stages, remain undetected. Undoubtedly, security operators of large enterprises are faced with a typical Big Data problem. In this thesis, we propose and implement a prototypical SIEM system named Real-Time Event Analysis and Monitoring System (REAMS) that addresses the Big Data challenges of event data with common paradigms, such as data normalization, multi-threading, in-memory storage, and distributed processing. In particular, a mostly stream-based event processing workflow is proposed that collects, normalizes, persists and analyzes events in near real-time. In this regard, we have made various contributions in the SIEM context. First, we propose a high-performance normalization algorithm that is highly parallelized across threads and distributed across nodes. Second, we are persisting into an in-memory database for fast querying and correlation in the context of attack detection. Third, we propose various analysis layers, such as anomaly- and signature-based detection, that run on top of the normalized and correlated events. As a result, we demonstrate our capabilities to detect previously known as well as unknown attack patterns. Lastly, we have investigated the integration of cyber threat intelligence (CTI) into the analytical process, for instance, for correlating monitored user accounts with previously collected public identity leaks to identify possible compromised user accounts. In summary, we show that a SIEM system can indeed monitor a large enterprise environment with a massive load of incoming events. As a result, complex attacks spanning across the whole network can be uncovered and mitigated, which is an advancement in comparison to existing SIEM systems on the market.},
  language  = {en}
}
@phdthesis{SanchezGarcia2018,
  author    = {S{\´a}nchez Garc{\´i}a, Mar{\´i}a Clemencia},
  title     = {El parlache como elemento evocador de la oralidad ficcional en la novela Rosario Tijeras, de Jorge Franco},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-415297},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxi, 283},
  year      = {2018},
  abstract  = {El objetivo de este trabajo es investigar c{\´o}mo se evoca la realidad del habla en la novela Rosario Tijeras, del colombiano Jorge Franco, y sus traducciones al alem{\´a}n y al ingl{\´e}s. En esta novela negra, el autor recurre a un lenguaje coloquial llamado parlache, t{\´i}pico de un sector socioecon{\´o}mico marginal de Medell{\´i}n, y cuya influencia se ha extendido a todos los {\´a}mbitos de la ciudad y del pa{\´i}s. El estudio se centrar{\´a} en la descripci{\´o}n de la variaci{\´o}n diat{\´o}pica y diastr{\´a}tica en la ficci{\´o}n; concretamente, de las expresiones t{\´i}picas del parlache. Con ello se pretende determinar la contribuci{\´o}n de ciertos recursos ling{\"u}{\´i}sticos t{\´i}picos de esta variedad del espa{\~n}ol a la construcci{\´o}n de un di{\´a}logo hablado veros{\´i}mil. Adem{\´a}s, se estudiar{\´a} c{\´o}mo se reexpresa este «colorido local» en la evocaci{\´o}n de la oralidad en las traducciones. Se intentar{\´a}n determinar, por tanto, las divergencias de traducci{\´o}n y profundizar en la descripci{\´o}n de la variaci{\´o}n ling{\"u}{\´i}stica (diat{\´o}pica y diastr{\´a}tica) en la traducci{\´o}n literaria.},
  language  = {es}
}
@phdthesis{Fabian2018,
  author    = {Fabian, Jenny},
  title     = {Effects of algae on microbial carbon cycling in freshwaters},
  doi       = {10.25932/publishup-42222},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-422225},
  school      = {Universit{\"a}t Potsdam},
  pages     = {90},
  year      = {2018},
  abstract  = {Microbial processing of organic matter (OM) in the freshwater biosphere is a key component of global biogeochemical cycles. Freshwaters receive and process valuable amounts of leaf OM from their terrestrial landscape. These terrestrial subsidies provide an essential source of energy and nutrients to the aquatic environment as a function of heterotrophic processing by fungi and bacteria. Particularly in freshwaters with low in-situ primary production from algae (microalgae, cyanobacteria), microbial turnover of leaf OM significantly contributes to the productivity and functioning of freshwater ecosystems and not least their contribution to global carbon cycling. Based on differences in their chemical composition, it is believed that leaf OM is less bioavailable to microbial heterotrophs than OM photosynthetically produced by algae. Especially particulate leaf OM, consisting predominantly of structurally complex and aromatic polymers, is assumed highly resistant to enzymatic breakdown by microbial heterotrophs. However, recent research has demonstrated that OM produced by algae promotes the heterotrophic breakdown of leaf OM in aquatic ecosystems, with profound consequences for the metabolism of leaf carbon (C) within microbial food webs. In my thesis, I aimed at investigating the underlying mechanisms of this so called priming effect of algal OM on the use of leaf C in natural microbial communities, focusing on fungi and bacteria. The works of my thesis underline that algal OM provides highly bioavailable compounds to the microbial community that are quickly assimilated by bacteria (Paper II). The substrate composition of OM pools determines the proportion of fungi and bacteria within the microbial community (Paper I). Thereby, the fraction of algae OM in the aquatic OM pool stimulates the activity and hence contribution of bacterial communities to leaf C turnover by providing an essential energy and nutrient source for the assimilation of the structural complex leaf OM substrate. On the contrary, the assimilation of algal OM remains limited for fungal communities as a function of nutrient competition between fungi and bacteria (Paper I, II). In addition, results provide evidence that environmental conditions determine the strength of interactions between microalgae and heterotrophic bacteria during leaf OM decomposition (Paper I, III). However, the stimulatory effect of algal photoautotrophic activities on leaf C turnover remained significant even under highly dynamic environmental conditions, highlighting their functional role for ecosystem processes (Paper III). The results of my thesis provide insights into the mechanisms by which algae affect the microbial turnover of leaf C in freshwaters. This in turn contributes to a better understanding of the function of algae in freshwater biogeochemical cycles, especially with regard to their interaction with the heterotrophic community.},
  language  = {en}
}
@phdthesis{SaadHassanin2018,
  author    = {Saad Hassanin, Alshaimaa},
  title     = {Dynamic coronal mass ejection process and magnetic reconnection},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419626},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xix, 113},
  year      = {2018},
  abstract  = {The Sun is the nearest star to the Earth. It consists of an interior and an atmosphere. The convection zone is the outermost layer of the solar interior. A flux rope may emerge as a coherent structure from the convection zone into the solar atmosphere or be formed by magnetic reconnection in the atmosphere. A flux rope is a bundle of magnetic field lines twisting around an axis field line, creating a helical shape by which dense filament material can be supported against gravity. The flux rope is also considered as the key structure of the most energetic phenomena in the solar system, such as coronal mass ejections (CMEs) and flares. These magnetic flux ropes can produce severe geomagnetic storms. In particular, to improve the ability to forecast space weather, it is important to enrich our knowledge about the dynamic formation of flux ropes and the underlying physical mechanisms that initiate their eruption, such as a CME. A confined eruption consists of a filament eruption and usually an associated are, but does not evolve into a CME; rather, the moving plasma is halted in the solar corona and usually seen to fall back. The first detailed observations of a confined filament eruption were obtained on 2002 May 27by the TRACE satellite in the 195 A band. So, in the Chapter 3, we focus on a flux rope instability model. A twisted flux rope can become unstable by entering the kink instability regime. We show that the kink instability, which occurs if the twist of a flux rope exceeds a critical value, is capable of initiating of an eruption. This model is tested against the well observed confined eruption on 2002 May 27 in a parametric magnetohydrodynamic (MHD) simulation study that comprises all phases of the event. Very good agreement with the essential observed properties is obtained, only except for a relatively poor matching of the initial filament height. Therefore, in Chapter 4, we submerge the center point of the flux rope deeper below the photosphere to obtain a flatter coronal rope section and a better matching with the initial height profile of the erupting filament. This implies a more realistic inclusion of the photospheric line tying. All basic assumptions and the other parameter settings are kept the same as in Chapter 3. This complement of the parametric study shows that the flux rope instability model can yield an even better match with the observational data. We also focus in Chapters 3 and 4 on the magnetic reconnection during the confined eruption, demonstrating that it occurs in two distinct locations and phases that correspond to the observed brightenings and changes of topology, and consider the fate of the erupting flux, which can reform a (less twisted) flux rope. The Sun also produces series of homologous eruptions, i.e. eruptions which occur repetitively in the same active region and are of similar morphology. Therefore, in Chapter 5, we employ the reformed flux rope as a new initial condition, to investigate the possibility of subsequent homologous eruptions. Free magnetic energy is built up by imposing motions in the bottom boundary, such as converging motions, leading to flux cancellation. We apply converging motions in the sunspot area, such that a small part of the flux from the sunspots with different polarities is transported toward the polarity inversion line (PIL) and cancels with each other. The reconnection associated with the cancellation process forms more helical magnetic flux around the reformed flux rope, which leads to a second and a third eruption. In this study, we obtain the first MHD simulation results of a homologous sequence of eruptions that show a transition from a confined to two ejective eruptions, based on the reformation of a flux rope after each eruption.},
  language  = {en}
}
@phdthesis{Choi2018,
  author    = {Choi, Youngeun},
  title     = {DNA origami structures as versatile platforms for nanophotonics},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421483},
  school      = {Universit{\"a}t Potsdam},
  pages     = {125},
  year      = {2018},
  abstract  = {Nanophotonics is the field of science and engineering aimed at studying the light-matter interactions on the nanoscale. One of the key aspects in studying such optics at the nanoscale is the ability to assemble the material components in a spatially controlled manner. In this work, DNA origami nanostructures were used to self-assemble dye molecules and DNA coated plasmonic nanoparticles. Optical properties of dye nanoarrays, where the dyes were arranged at distances where they can interact by F{\"o}rster resonance energy transfer (FRET), were systematically studied according to the size and arrangement of the dyes using fluorescein (FAM) as the donor and cyanine 3 (Cy 3) as the acceptor. The optimized design, based on steady-state and time-resolved fluorometry, was utilized in developing a ratiometric pH sensor with pH-inert coumarin 343 (C343) as the donor and pH-sensitive FAM as the acceptor. This design was further applied in developing a ratiometric toxin sensor, where the donor C343 is unresponsive and FAM is responsive to thioacetamide (TAA) which is a well-known hepatotoxin. The results indicate that the sensitivity of the ratiometric sensor can be improved by simply arranging the dyes into a well-defined array. The ability to assemble multiple fluorophores without dye-dye aggregation also provides a strategy to amplify the signal measured from a fluorescent reporter, and was utilized here to develop a reporter for sensing oligonucleotides. By incorporating target capturing sequences and multiple fluorophores (ATTO 647N dye molecules), a reporter for microbead-based assay for non-amplified target oligonucleotide sensing was developed. Analysis of the assay using VideoScan, a fluorescence microscope-based technology capable of conducting multiplex analysis, showed the DNA origami nanostructure based reporter to have a lower limit of detection than a single stranded DNA reporter. Lastly, plasmonic nanostructures were assembled on DNA origami nanostructures as substrates to study interesting optical behaviors of molecules in the near-field. Specifically, DNA coated gold nanoparticles, silver nanoparticles, and gold nanorods, were placed on the DNA origami nanostructure aiming to study surface-enhanced fluorescence (SEF) and surface-enhanced Raman scattering (SERS) of molecules placed in the hotspot of coupled plasmonic structures.},
  language  = {en}
}
@phdthesis{Bazhenova2018,
  author    = {Bazhenova, Ekaterina},
  title     = {Discovery of Decision Models Complementary to Process Models},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-410020},
  school      = {Universit{\"a}t Potsdam},
  year      = {2018},
  abstract  = {Business process management is an acknowledged asset for running an organization in a productive and sustainable way. One of the most important aspects of business process management, occurring on a daily basis at all levels, is decision making. In recent years, a number of decision management frameworks have appeared in addition to existing business process management systems. More recently, Decision Model and Notation (DMN) was developed by the OMG consortium with the aim of complementing the widely used Business Process Model and Notation (BPMN). One of the reasons for the emergence of DMN is the increasing interest in the evolving paradigm known as the separation of concerns. This paradigm states that modeling decisions complementary to processes reduces process complexity by externalizing decision logic from process models and importing it into a dedicated decision model. Such an approach increases the agility of model design and execution. This provides organizations with the flexibility to adapt to the ever increasing rapid and dynamic changes in the business ecosystem. The research gap, identified by us, is that the separation of concerns, recommended by DMN, prescribes the externalization of the decision logic of process models in one or more separate decision models, but it does not specify this can be achieved. The goal of this thesis is to overcome the presented gap by developing a framework for discovering decision models in a semi-automated way from information about existing process decision making. Thus, in this thesis we develop methodologies to extract decision models from: (1) control flow and data of process models that exist in enterprises; and (2) from event logs recorded by enterprise information systems, encapsulating day-to-day operations. Furthermore, we provide an extension of the methodologies to discover decision models from event logs enriched with fuzziness, a tool dealing with partial knowledge of the process execution information. All the proposed techniques are implemented and evaluated in case studies using real-life and synthetic process models and event logs. The evaluation of these case studies shows that the proposed methodologies provide valid and accurate output decision models that can serve as blueprints for executing decisions complementary to process models. Thus, these methodologies have applicability in the real world and they can be used, for example, for compliance checks, among other uses, which could improve the organization's decision making and hence it's overall performance.},
  language  = {en}
}