@misc{McKennaLeimkuehlerHerteretal.2015, author = {McKenna, Shane M. and Leimk{\"u}hler, Silke and Herter, Susanne and Turner, Nicholas J. and Carnell, Andrew J.}, title = {Enzyme cascade reactions}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-102271}, pages = {3271 -- 3275}, year = {2015}, abstract = {A one-pot tandem enzyme reaction using galactose oxidase M3-5 and aldehyde oxidase PaoABC was used to convert hydroxymethylfurfural (HMF) to the pure bioplastics precursor FDCA in 74\% isolated yield. A range of alcohols was also converted to carboxylic acids in high yield under mild conditions.}, language = {en} } @phdthesis{Brachs2015, author = {Brachs, Maria}, title = {Genome wide expression analysis and metabolic mechanisms predicting body weight maintenance}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-100767}, school = {Universit{\"a}t Potsdam}, pages = {106}, year = {2015}, abstract = {Obesity is a major health problem for many developing and industrial countries. Increasing rates reach almost 50 \% of the population in some countries and related metabolic diseases including cardiovascular events and T2DM are challenging the health systems. Adiposity, an increase in body fat mass, is a major hallmark of obesity. Adipose tissue is long known not only to store lipids but also to influence whole-body metabolism including food intake, energy expenditure and insulin sensitivity. Adipocytes can store lipids and thereby protect other tissue from lipotoxic damage. However, if the energy intake is higher than the energy expenditure over a sustained time period, adipose tissue will expand. This can lead to an impaired adipose tissue function resulting in higher levels of plasma lipids, which can affect other tissue like skeletal muscle, finally leading to metabolic complications. Several studies showed beneficial metabolic effects of weight reduction in obese subjects immediately after weight loss. However, weight regain is frequently observed along with potential negative effects on cardiovascular risk factors and a high intra-individual response. We performed a body weight maintenance study investigating the mechanisms of weight maintenance after intended WR. Therefore we used a low caloric diet followed by a 12-month life-style intervention. Comprehensive phenotyping including fat and muscle biopsies was conducted to investigate hormonal as well as metabolic influences on body weight regulation. In this study, we showed that weight reduction has numerous potentially beneficial effects on metabolic parameters. After 3-month WR subjects showed significant weight and fat mass reduction, lower TG levels as well as higher insulin sensitivity. Using RNA-Seq to analyse whole fat and muscle transcriptome a strong impact of weight reduction on adipose tissue gene expression was observed. Gene expression alterations over weight reduction included several cellular metabolic genes involved in lipid and glucose metabolism as well as insulin signalling and regulatory pathways. These changes were also associated with anthropometric parameters assigning body composition. Our data indicated that weight reduction leads to a decreased expression of several lipid catabolic as well as anabolic genes. Long-term body weight maintenance might be influenced by several parameters including hormones, metabolic intermediates as well as the transcriptional landscape of metabolic active tissues. Our data showed that genes involved in biosynthesis of unsaturated fatty acids might influence the BMI 18-month after a weight reduction phase. This was further supported by analysing metabolic parameters including RQ and FFA levels. We could show that subjects maintaining their lost body weight had a higher RQ and lower FFA levels, indicating increased metabolic flexibility in subjects. Using this transcriptomic approach we hypothesize that low expression levels of lipid synthetic genes in adipose tissue together with a higher mitochondrial activity in skeletal muscle tissue might be beneficial in terms of body weight maintenance.}, language = {en} } @phdthesis{Radenacker2015, author = {Radenacker, Anke}, title = {Economic consequences of family dissolution}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-100217}, school = {Universit{\"a}t Potsdam}, pages = {v, 134}, year = {2015}, abstract = {Welfare states and policies have changed greatly over the past decades, mostly characterized by retrenchments in terms of government spending or in terms of restricted access to certain benefits. In the area of family policies, however, a lot of countries have simultaneously expanded provisions and transfers for families. Bringing together the macro analysis of policy variation and household income changes on the micro-level, the main research question of the dissertation is to what extent economic consequences following separation and divorce in families with children have changed between the 1980s and the 2000s in Germany and the United States. The second research question of the dissertation regards the differences in dissolution outcomes between married and cohabiting parents in Germany. The dissertation thus aims to link institutional regulations of welfare states with the actual income situation of families. To achieve this, a research design was developed that has never been used for the analysis of the economic consequences of family dissolution. For this, the two longest running panel datasets, German Socio-economic Panel (GSOEP) and the US American Panel Study of Income Dynamics (PSID), have been used. The analytic strategy applied to estimate the effects of family dissolution on household income is a difference-in-difference design combined with coarsened exact matching (CEM). To begin with, the dissertation confirmed many findings of previous research, for example regarding the gender differences in family dissolution outcomes. Mothers experience clearly higher relative income losses and consequently higher risks of poverty than fathers. This finding is universal, that is it holds for both countries, for all time periods observed, and for all measures of economic outcome that were employed. Another confirmed finding is the higher level of welfare state intervention in Germany compared to the United States. The dissertation also revealed a number of novel findings. The results show that the expansion of family policies in Germany over time has not been accompanied by substantially decreasing income losses for mothers. Though income losses have slightly decreased over time, they have become more persistent during the years following family dissolution. The impact of the German welfare state has meanwhile been quite stable. American mothers' income losses took place on a slightly lower level than those of German mothers. Only during the 1980s their relative losses were clearly lower than those of German mothers. And also American mothers did not recover as much from their income losses during the 2000s than they used to during the 1980s. For them, the 1996 welfare reform brought a considerable decrease in welfare state support. Accordingly, the results for American mothers can certainly be described as a shift from public to private provision. The general finding of previous studies that fathers do not have to suffer income losses, or if at all rather moderate ones compared to mothers, can be confirmed. Nevertheless, both German and US American fathers face a deterioration of the economic consequences of family dissolution over time. German fathers' relative income changes are still positive though they have decreased over time. One reason for this decrease is the increasing loss of partner earnings following union dissolution. Also among American fathers, income gains still prevail in the year of family dissolution. Two years later, however, they have been facing income losses already since the 1980s which have furthermore increased considerably over time. Zooming in on Germany, family dissolution outcomes by marital status show negligible differences between cohabiting and married mothers in disposable income, but considerable differences in losses of income before taxes and transfers. It is the impact of the welfare state that equalizes the differences in income losses between these two groups of mothers. For married mothers, losses are not as high in the year of event but they have difficulties to recover from these losses. Without the income buffering of the welfare state, married mothers would, three years after family dissolution, remain with relative income losses double as high as for cohabiting mothers. Compared to mothers, differences between married and cohabiting fathers are visible in changes of income before as well as after taxes and transfers. The welfare state does not alter the difference between the two groups of fathers. With regard to both income concepts, cohabiting fathers fare worse than married fathers. Cohabiting fathers suffer moderate income losses of disposable income while married fathers experience moderate income gains. Accounting for support payments is decisive for fathers' income changes. If these payments are not deducted from disposable income, both married and cohabiting fathers experience gains in disposable income following family dissolution.}, language = {en} } @misc{TremblayBlancoRey2015, author = {Tremblay, Jean Christophe and Blanco-Rey, Maria}, title = {Manipulating interfacial hydrogens at palladium via STM}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-99511}, pages = {11}, year = {2015}, abstract = {In this contribution, we provide a detailed dynamical analysis of the interfacial hydrogen migration mediated by scanning tunneling microscopy (STM). Contributions from the STM-current and from the non-adiabatic couplings are taken into account using only first principle models. The slight asymmetry of the tunnelling rates with respect to the potential bias sign inferred from experimental observations is reproduced by weighting the contributions of the metal acceptor-donor states for the propagation of the impinging electrons. The quasi-thermal inelastic collision mechanism is treated perturbatively. The influence of hydrogen pre-coverage is also investigated using new potential energy surfaces obtained from periodic density functional theory calculations. Fully quantum dynamical simulations of the system evolution are performed by solving the Pauli master equation, providing insight into the reaction mechanism of STM manipulation of subsurface hydrogens. It is observed that the hydrogen impurity favors resurfacing over occupation of the bulk and subsurface sites whenever possible. The present simulations give strong indication that the experimentally observed protuberances after STM-excitation are due to hydrogen accumulating in the vicinity of the surface.}, language = {en} } @misc{ChakrabortyChenBornhorstetal.2015, author = {Chakraborty, Sudipta and Chen, Pan and Bornhorst, Julia and Schwerdtle, Tanja and Schumacher, Fabian and Kleuser, Burkhard and Bowman, Aaron B. and Aschner, Michael A.}, title = {Loss of pdr-1/parkin influences Mn homeostasis through altered ferroportin expression in C. elegans}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-99508}, pages = {10}, year = {2015}, abstract = {Overexposure to the essential metal manganese (Mn) can result in an irreversible condition known as manganism that shares similar pathophysiology with Parkinson's disease (PD), including dopaminergic (DAergic) cell loss that leads to motor and cognitive impairments. However, the mechanisms behind this neurotoxicity and its relationship with PD remain unclear. Many genes confer risk for autosomal recessive, early-onset PD, including the parkin/PARK2 gene that encodes for the E3 ubiquitin ligase Parkin. Using Caenorhabditis elegans (C. elegans) as an invertebrate model that conserves the DAergic system, we previously reported significantly increased Mn accumulation in pdr-1/parkin mutants compared to wildtype (WT) animals. For the current study, we hypothesize that this enhanced accumulation is due to alterations in Mn transport in the pdr-1 mutants. While no change in mRNA expression of the major Mn importer proteins (smf-1-3) was found in pdr-1 mutants, significant downregulation in mRNA levels of the putative Mn exporter ferroportin (fpn-1.1) was observed. Using a strain overexpressing fpn-1.1 in worms lacking pdr-1, we show evidence for attenuation of several endpoints of Mn-induced toxicity, including survival, metal accumulation, mitochondrial copy number and DAergic integrity, compared to pdr-1 mutants alone. These changes suggest a novel role of pdr-1 in modulating Mn export through altered transporter expression, and provides further support of metal dyshomeostasis as a component of Parkinsonism pathophysiology.}, language = {en} } @phdthesis{Mitidieri2015, author = {Mitidieri, Gaetano}, title = {Wissenschaft, Technik und Medien im Werk Alfred D{\"o}blins im Kontext der europ{\"a}ischen Avantgarde}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-364-0}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89390}, school = {Universit{\"a}t Potsdam}, pages = {970}, year = {2015}, abstract = {Ziel dieser Studie ist es die bislang nur sporadisch untersuchten Wechselverh{\"a}ltnisse zwischen den Kulturbereichen Wissenschaft/Technik und Literatur am herausragenden Beispiel des Oeuvres des Schriftstellers und Arztes Alfred D{\"o}blin aufzusp{\"u}ren. Hierbei scheint seine {\"a}rztlich-psychiatrische Laufbahn, die eine breite Grundlage wissenschaftlicher Diskurse anbietet, wie auch seine avantgardistische Literaturpraxis diese gegenseitige Befruchtung gef{\"o}rdert zu haben. Im Hinblick auf den Forschungsgegenstand und -zweck ist ein kulturwissenschaftlicher Ansatz versucht worden. Dieser vielperspektivische Ansatz, der von der Pr{\"a}misse eines Wechselspiels aller Kulturbereiche untereinander ausgeht, gestattet eine dem Gegenstand angepasste Verkn{\"u}pfung von verschiedenen Arbeitsmethoden wie der philologisch-literarhistorischen mit der konstruktivistischen und der komparatistischen. Hierbei ist eine Einbeziehung wissenschafts- und technikphilosophischer Reflexion wie auch eine dementsprechend erweiterte kulturhistorische Kontextualisierung vorgenommen worden. Die hier vorgelegte Analyse fokussiert auf wissenschaftlich-technische Bez{\"u}ge sowohl in thematischer Hinsicht als auch in der Textgestaltung der schriftstellerischen Werke D{\"o}blins bis 1924. Gleichzeitig wird die diskursgepr{\"a}gte, sprachliche und literarische Dimension seiner wissenschaftlichen Studien und technischer Texte - wie Krankenakte - hervorgehoben. Dieses erweiterte ‚Oeuvre'-Konzept gestattet die Analyse der psychiatrischen, klinisch-{\"a}rztlichen und biochemischen Schriften D{\"o}blins sowie seiner Erz{\"a}hlwerke, seiner vielgestaltigen Publizistik und seiner intermedialen Anregungen aus den neuen audiovisuellen Medien. Dadurch wird eine diskurskritische kultur{\"u}bergreifende Interdiskursivit{\"a}t wie auch eine ‚Hybridit{\"a}t' aller Texte aufgezeigt, die die Grundunterschiede zwischen Textsorten und Gattungsgrenzen relativiert.}, language = {de} } @phdthesis{Reimer2015, author = {Reimer, Anna Maria}, title = {The poetics of the real and aesthetics of the reel}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-95660}, school = {Universit{\"a}t Potsdam}, pages = {298}, year = {2015}, abstract = {The dissertation proposes that the spread of photography and popular cinema in 19th- and 20th-century-India have shaped an aesthetic and affective code integral to the reading and interpretation of Indian English novels, particularly when they address photography and/or cinema film, as in the case of the four corpus texts. In analyzing the nexus between 'real' and 'reel', the dissertation shows how the texts address the reader as media consumer and virtual image projector. Furthermore, the study discusses the Indian English novel against the backdrop of the cultural and medial transformations of the 20th century to elaborate how these influenced the novel's aesthetics. Drawing upon reception aesthetics, the author devises the concept of the 'implied spectator' to analyze the aesthetic impact of the novels' images as visual textures. No God in Sight (2005) by Altaf Tyrewala comprises of a string of 41 interior monologues, loosely connected through their narrators' random encounters in Mumbai in the year 2000. Although marked by continuous perspective shifts, the text creates a sensation of acute immediacy. Here, the reader is addressed as implied spectator and is sutured into the narrated world like a film spectator ― an effect created through the use of continuity editing as a narrative technique. Similarly, Ruchir Joshi's The Last Jet Engine Laugh (2002) coll(oc)ates disparate narrative perspectives and explores photography as an artistic practice, historiographic recorder and epistemological tool. The narrative appears guided by the random viewing of old photographs by the protagonist and primary narrator, the photographer Paresh Bhatt. However, it is the photographic negative and the practice of superimposition that render this string of episodes and different perspectives narratively consequential and cosmologically meaningful. Photography thus marks the perfect symbiosis of autobiography and historiography. Tabish Khair's Filming. A Love Story (2007) immerses readers in the cine-aesthetic of 1930s and 40s Bombay film, the era in which the embedded plot is set. Plotline, central scenes and characters evoke the key films of Indian cinema history such as Satyajit Ray's "Pather Panchali" or Raj Kapoor's "Awara". Ultimately, the text written as film dissolves the boundary between fiction and (narrated) reality, reel and real, thereby showing that the images of individual memory are inextricably intertwined with and shaped by collective memory. Ultimately, the reconstruction of the past as and through film(s) conquers trauma and endows the Partition of India as a historic experience of brutal contingency with meaning. The Bioscope Man (Indrajit Hazra, 2008) is a picaresque narrative set in Calcutta - India's cultural capital and birthplace of Indian cinema at the beginning of the 20th century. The autodiegetic narrator Abani Chatterjee relates his rise and fall as silent film star, alternating between the modes of tell and show. He is both autodiegetic narrator and spectator or perceiving consciousness, seeing himself in his manifold screen roles. Beyond his film roles however, the narrator remains a void. The marked psychoanalytical symbolism of the text is accentuated by repeated invocations of dark caves and the laterna magica. Here too, 'reel life' mirrors and foreshadows real life as Indian and Bengali history again interlace with private history. Abani Chatterjee thus emerges as a quintessentially modern man of no qualities who assumes definitive shape only in the lost reels of the films he starred in. The final chapter argues that the static images and visual frames forwarded in the texts observe an integral psychological function: Premised upon linear perspective they imply a singular, static subjectivity appealing to the postmodern subject. In the corpus texts, the rise of digital technology in the 1990s thus appears not so much to have displaced older image repertories, practices and media techniques, than it has lent them greater visibility and appeal. Moreover, bricolage and pastiche emerge as cultural techniques which marked modernity from its inception. What the novels thus perpetuate is a media archeology not entirely servant to the poetics of the real. The permeable subject and the notion of the gaze as an active exchange as encapsulated in the concept of darshan - ideas informing all four texts - bespeak the resilience of a mythical universe continually re-instantiated in new technologies and uses. Eventually, the novels convey a sense of subalternity to a substantially Hindu nationalist history and historiography, the centrifugal force of which developed in the twentieth century and continues into the present.}, language = {en} } @misc{Erdmann2015, author = {Erdmann, Julius}, title = {Semiotics of Pictorial Signs on Social Networking Sites}, series = {Postprints der Universit{\"a}t Potsdam : Philosophische Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Philosophische Reihe}, number = {118}, issn = {1866-8380}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-96484}, pages = {16}, year = {2015}, abstract = {The paper aims at considering characteristics from one field of contemporary visual studies that has for a long time been neglected in academic research: Pictorial signs on Social Network Sites (SNS) are an outstanding class of semiotic resources that is greatly shaped by processes of technological and collective sign production and distribution. A brief examination of the scholarly research on the pragmatics and semiotics of pictorial signs on SNS shows that the heterogeneity of visual signs is often neglected and that it mostly concentrates on one aspect of these pictorial signs: their technological production or their purpose for individual self-disclosure. The paper therefore considers the semiosis of pictorial signs on SNS in a holistic perspective as one the one hand produced by individual and collective meaning making as well as on the other hand a product of technological framing. It therefore develops a techno-semiotic pragmatic account that takes into consideration both processes. Starting from a prominent class of pictorial signs on SNS during Tunisian Revolution, the Tunisian Flag graphics, the paper than shows that communicative and social interaction functions on the graphic interface of SNS ('like'-function, sharing and commenting option) are not only directly inscribed into the pictorial frame, but also greatly influence the reading of a pictorial sign. The location of images on the SNS' interface has an impact on its meaning and on the social functions of a pictorial sign, as profile pictures are directly linked to the online identity of the user. Through technological sign processing, the polysemy of the image is reduced. We therefore consider the images on the one hand as individual self-narratives and on the other as instances of SNS' visual culture that brings out dominant visual codes but also allows social and political movements to spread.}, language = {de} } @phdthesis{Dunlop2015, author = {Dunlop, John William Chapman}, title = {The physics of shape changes in biology}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-96554}, school = {Universit{\"a}t Potsdam}, pages = {vii, 202}, year = {2015}, abstract = {Biological materials, in addition to having remarkable physical properties, can also change shape and volume. These shape and volume changes allow organisms to form new tissue during growth and morphogenesis, as well as to repair and remodel old tissues. In addition shape or volume changes in an existing tissue can lead to useful motion or force generation (actuation) that may even still function in the dead organism, such as in the well known example of the hygroscopic opening or closing behaviour of the pine cone. Both growth and actuation of tissues are mediated, in addition to biochemical factors, by the physical constraints of the surrounding environment and the architecture of the underlying tissue. This habilitation thesis describes biophysical studies carried out over the past years on growth and swelling mediated shape changes in biological systems. These studies use a combination of theoretical and experimental tools to attempt to elucidate the physical mechanisms governing geometry controlled tissue growth and geometry constrained tissue swelling. It is hoped that in addition to helping understand fundamental processes of growth and morphogenesis, ideas stemming from such studies can also be used to design new materials for medicine and robotics.}, language = {en} } @book{OPUS4-8381, title = {Proceedings of the Master seminar on event processing systems for business process management systems}, number = {102}, editor = {Baumgraß, Anne and Meyer, Andreas and Weske, Mathias}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-347-3}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-83819}, publisher = {Universit{\"a}t Potsdam}, pages = {vii, 67}, year = {2015}, abstract = {Traditionally, business process management systems only execute and monitor business process instances based on events that originate from the process engine itself or from connected client applications. However, environmental events may also influence business process execution. Recent research shows how the technological improvements in both areas, business process management and complex event processing, can be combined and harmonized. The series of technical reports included in this collection provides insights in that combination with respect to technical feasibility and improvements based on real-world use cases originating from the EU-funded GET Service project - a project targeting transport optimization and green-house gas reduction in the logistics domain. Each report is complemented by a working prototype. This collection introduces six use cases from the logistics domain. Multiple transports - each being a single process instance - may be affected by the same events at the same point in time because of (partly) using the same transportation route, transportation vehicle or transportation mode (e.g. containers from multiple process instances on the same ship) such that these instances can be (partly) treated as batch. Thus, the first use case shows the influence of events to process instances processed in a batch. The case of sharing the entire route may be, for instance, due to origin from the same business process (e.g. transport three containers, where each is treated as single process instance because of being transported on three trucks) resulting in multi-instance process executions. The second use case shows how to handle monitoring and progress calculation in this context. Crucial to transportation processes are frequent changes of deadlines. The third use case shows how to deal with such frequent process changes in terms of propagating the changes along and beyond the process scope to identify probable deadline violations. While monitoring transport processes, disruptions may be detected which introduce some delay. Use case four shows how to propagate such delay in a non-linear fashion along the process instance to predict the end time of the instance. Non-linearity is crucial in logistics because of buffer times and missed connection on intermodal transports (a one-hour delay may result in a missed ship which is not going every hour). Finally, use cases five and six show the utilization of location-based process monitoring. Use case five enriches transport processes with real-time route and traffic event information to improve monitoring and planning capabilities. Use case six shows the inclusion of spatio-temporal events on the example of unexpected weather events.}, language = {en} } @misc{HeistermannCollisDixonetal.2015, author = {Heistermann, Maik and Collis, Scott and Dixon, M. J. and Helmus, J. J. and Henja, A. and Michelson, D. B. and Pfaff, Thomas}, title = {An Open Virtual Machine for Cross-Platform Weather Radar Science}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-96604}, pages = {1641 -- 1645}, year = {2015}, abstract = {In a recent BAMS article, it is argued that community-based Open Source Software (OSS) could foster scientific progress in weather radar research, and make weather radar software more affordable, flexible, transparent, sustainable, and interoperable. Nevertheless, it can be challenging for potential developers and users to realize these benefits: tools are often cumbersome to install; different operating systems may have particular issues, or may not be supported at all; and many tools have steep learning curves. To overcome some of these barriers, we present an open, community-based virtual machine (VM). This VM can be run on any operating system, and guarantees reproducibility of results across platforms. It contains a suite of independent OSS weather radar tools (BALTRAD, Py-ART, wradlib, RSL, and Radx), and a scientific Python stack. Furthermore, it features a suite of recipes that work out of the box and provide guidance on how to use the different OSS tools alone and together. The code to build the VM from source is hosted on GitHub, which allows the VM to grow with its community. We argue that the VM presents another step toward Open (Weather Radar) Science. It can be used as a quick way to get started, for teaching, or for benchmarking and combining different tools. It can foster the idea of reproducible research in scientific publishing. Being scalable and extendable, it might even allow for real-time data processing. We expect the VM to catalyze progress toward interoperability, and to lower the barrier for new users and developers, thus extending the weather radar community and user base.}, language = {en} } @misc{MuinodeBruijnPajoroetal.2015, author = {Mui{\~n}o, Jose M. and de Bruijn, Suzanne and Pajoro, Alice and Geuten, Koen and Vingron, Martin and Angenent, Gerco C. and Kaufmann, Kerstin}, title = {Evolution of DNA-Binding Sites of a Floral Master Regulatory Transcription Factor}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-96580}, pages = {1225 -- 1245}, year = {2015}, abstract = {Flower development is controlled by the action of key regulatory transcription factors of the MADS-domain family. The function of these factors appears to be highly conserved among species based on mutant phenotypes. However, the conservation of their downstream processes is much less well understood, mostly because the evolutionary turnover and variation of their DNA-binding sites (BSs) among plant species have not yet been experimentally determined. Here, we performed comparative ChIP (chromatin immunoprecipitation)-seq experiments of the MADS-domain transcription factor SEPALLATA3 (SEP3) in two closely related Arabidopsis species: Arabidopsis thaliana and A. lyrata which have very similar floral organ morphology. We found that BS conservation is associated with DNA sequence conservation, the presence of the CArG-box BS motif and on the relative position of the BS to its potential target gene. Differences in genome size and structure can explain that SEP3 BSs in A. lyrata can be located more distantly to their potential target genes than their counterparts in A. thaliana. In A. lyrata, we identified transposition as a mechanism to generate novel SEP3 binding locations in the genome. Comparative gene expression analysis shows that the loss/gain of BSs is associated with a change in gene expression. In summary, this study investigates the evolutionary dynamics of DNA BSs of a floral key-regulatory transcription factor and explores factors affecting this phenomenon.}, language = {en} } @misc{KormannFranckeRenneretal.2015, author = {Kormann, C. and Francke, Till and Renner, M. and Bronstert, Axel}, title = {Attribution of high resolution streamflow trends in Western Austria}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-96560}, pages = {1225 -- 1245}, year = {2015}, abstract = {The results of streamflow trend studies are often characterized by mostly insignificant trends and inexplicable spatial patterns. In our study region, Western Austria, this applies especially for trends of annually averaged runoff. However, analysing the altitudinal aspect, we found that there is a trend gradient from higher-altitude to lower-altitude stations, i.e. a pattern of mostly positive annual trends at higher stations and negative ones at lower stations. At midaltitudes, the trends are mostly insignificant. Here we hypothesize that the streamflow trends are caused by the following two main processes: on the one hand, melting glaciers produce excess runoff at higher-altitude watersheds. On the other hand, rising temperatures potentially alter hydrological conditions in terms of less snowfall, higher infiltration, enhanced evapotranspiration, etc., which in turn results in decreasing streamflow trends at lower-altitude watersheds. However, these patterns are masked at mid-altitudes because the resulting positive and negative trends balance each other. To support these hypotheses, we attempted to attribute the detected trends to specific causes. For this purpose, we analysed trends of filtered daily streamflow data, as the causes for these changes might be restricted to a smaller temporal scale than the annual one. This allowed for the explicit determination of the exact days of year (DOYs) when certain streamflow trends emerge, which were then linked with the corresponding DOYs of the trends and characteristic dates of other observed variables, e.g. the average DOY when temperature crosses the freezing point in spring. Based on these analyses, an empirical statistical model was derived that was able to simulate daily streamflow trends sufficiently well. Analyses of subdaily streamflow changes provided additional insights. Finally, the present study supports many modelling approaches in the literature which found out that the main drivers of alpine streamflow changes are increased glacial melt, earlier snowmelt and lower snow accumulation in wintertime.}, language = {en} } @misc{LobmaierFischer2015, author = {Lobmaier, Janek S. and Fischer, Martin H.}, title = {Facial Feedback Affects Perceived Intensity but Not Quality of Emotional Expressions}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-96428}, pages = {357 -- 368}, year = {2015}, abstract = {Motivated by conflicting evidence in the literature, we re-assessed the role of facial feedback when detecting quantitative or qualitative changes in others' emotional expressions. Fifty-three healthy adults observed self-paced morph sequences where the emotional facial expression either changed quantitatively (i.e., sad-to-neutral, neutral-to-sad, happy-to-neutral, neutral-to-happy) or qualitatively (i.e. from sad to happy, or from happy to sad). Observers held a pen in their own mouth to induce smiling or frowning during the detection task. When morph sequences started or ended with neutral expressions we replicated a congruency effect: Happiness was perceived longer and sooner while smiling; sadness was perceived longer and sooner while frowning. Interestingly, no such congruency effects occurred for transitions between emotional expressions. These results suggest that facial feedback is especially useful when evaluating the intensity of a facial expression, but less so when we have to recognize which emotion our counterpart is expressing.}, language = {en} } @misc{KappelTrostCzesnicketal.2015, author = {Kappel, Christian and Trost, Gerda and Czesnick, Hj{\"o}rdis and Ramming, Anna and Kolbe, Benjamin and Vi, Song Lang and Bispo, Cl{\´a}udia and Becker, J{\"o}rg D. and de Moor, Cornelia and Lenhard, Michael}, title = {Genome-Wide Analysis of PAPS1-Dependent Polyadenylation Identifies Novel Roles for Functionally Specialized Poly(A) Polymerases in Arabidopsis thaliana}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-96400}, pages = {1 -- 30}, year = {2015}, abstract = {The poly(A) tail at 3' ends of eukaryotic mRNAs promotes their nuclear export, stability and translational efficiency, and changes in its length can strongly impact gene expression. The Arabidopsis thaliana genome encodes three canonical nuclear poly(A) polymerases, PAPS1, PAPS2 and PAPS4. As shown by their different mutant phenotypes, these three isoforms are functionally specialized, with PAPS1 modifying organ growth and suppressing a constitutive immune response. However, the molecular basis of this specialization is largely unknown. Here, we have estimated poly(A)-tail lengths on a transcriptome-wide scale in wild-type and paps1 mutants. This identified categories of genes as particularly strongly affected in paps1 mutants, including genes encoding ribosomal proteins, cell-division factors and major carbohydrate-metabolic proteins. We experimentally verified two novel functions of PAPS1 in ribosome biogenesis and redox homoeostasis that were predicted based on the analysis of poly(A)-tail length changes in paps1 mutants. When overlaying the PAPS1-dependent effects observed here with coexpression analysis based on independent microarray data, the two clusters of transcripts that are most closely coexpressed with PAPS1 show the strongest change in poly(A)-tail length and transcript abundance in paps1 mutants in our analysis. This suggests that their coexpression reflects at least partly the preferential polyadenylation of these transcripts by PAPS1 versus the other two poly(A)-polymerase isoforms. Thus, transcriptome-wide analysis of poly(A)-tail lengths identifies novel biological functions and likely target transcripts for polyadenylation by PAPS1. Data integration with large-scale co-expression data suggests that changes in the relative activities of the isoforms are used as an endogenous mechanism to co-ordinately modulate plant gene expression.}, language = {en} } @misc{KumarGoodwinUhouseetal.2015, author = {Kumar, Kevin K. and Goodwin, Cody R. and Uhouse, Michael A. and Bornhorst, Julia and Schwerdtle, Tanja and Aschner, Michael A. and McLean, John A. and Bowman, Aaron B.}, title = {Untargeted metabolic profiling identifies interactions between Huntington's disease and neuronal manganese status}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-94314}, pages = {363 -- 370}, year = {2015}, abstract = {Manganese (Mn) is an essential micronutrient for development and function of the nervous system. Deficiencies in Mn transport have been implicated in the pathogenesis of Huntington's disease (HD), an autosomal dominant neurodegenerative disorder characterized by loss of medium spiny neurons of the striatum. Brain Mn levels are highest in striatum and other basal ganglia structures, the most sensitive brain regions to Mn neurotoxicity. Mouse models of HD exhibit decreased striatal Mn accumulation and HD striatal neuron models are resistant to Mn cytotoxicity. We hypothesized that the observed modulation of Mn cellular transport is associated with compensatory metabolic responses to HD pathology. Here we use an untargeted metabolomics approach by performing ultraperformance liquid chromatography-ion mobility-mass spectrometry (UPLC-IM-MS) on control and HD immortalized mouse striatal neurons to identify metabolic disruptions under three Mn exposure conditions, low (vehicle), moderate (non-cytotoxic) and high (cytotoxic). Our analysis revealed lower metabolite levels of pantothenic acid, and glutathione (GSH) in HD striatal cells relative to control cells. HD striatal cells also exhibited lower abundance and impaired induction of isobutyryl carnitine in response to increasing Mn exposure. In addition, we observed induction of metabolites in the pentose shunt pathway in HD striatal cells after high Mn exposure. These findings provide metabolic evidence of an interaction between the HD genotype and biologically relevant levels of Mn in a striatal cell model with known HD by Mn exposure interactions. The metabolic phenotypes detected support existing hypotheses that changes in energetic processes underlie the pathobiology of both HD and Mn neurotoxicity.}, language = {en} } @misc{Weiss2015, author = {Weiß, Norman}, title = {The Nature of Children's Well-Being, Theory and Practice [rezensiert von Norman Weiß]}, series = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, volume = {20}, journal = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, number = {2}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1434-2820}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-94969}, pages = {130 -- 130}, year = {2015}, abstract = {Buchbesprechung: Alexander Bagattini/Colin Macleod (Hrsg.), The Nature of Children's Well-Being, Theory and Practice (Children's Well-Being: Indicators and Research, 9), Springer, 2015, 262 Seiten, ISBN 978-94-017-9251-6.}, language = {de} } @article{Naegeler2015, author = {N{\"a}geler, Pascal}, title = {Bericht {\"u}ber die T{\"a}tigkeit des Menschenrechtsausschusses der Vereinten Nationen im Jahre 2014 - Teil II: Individualbeschwerden}, series = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, volume = {20}, journal = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, number = {2}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1434-2820}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-94943}, pages = {117 -- 129}, year = {2015}, abstract = {I. Einf{\"u}hrung II. Das Individualbeschwerdeverfahren III. Statistische Angaben IV. Zul{\"a}ssigkeitsfragen V. Materiellrechtliche Fragen}, language = {de} } @article{Volger2015, author = {Volger, Helmut}, title = {Die St{\"a}rkung der Vertragsorgane im UN-Menschenrechtssystem}, series = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, volume = {20}, journal = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, number = {2}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1434-2820}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-94938}, pages = {107 -- 116}, year = {2015}, abstract = {I. Das UN-Menschenrechtsschutzsystem II. Die Menschenrechtsvertragsorgane III. Das System der Menschenrechtsvertragsorgane in der Praxis IV. Die Reform der Vertragsorgane V. Der Abschluss des Reformprozesses: Resolution 68/268 VI. Fazit}, language = {de} } @article{Richter2015, author = {Richter, Dagmar}, title = {Recht des Tieres und menschliche Interessen}, series = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, volume = {20}, journal = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, number = {2}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1434-2820}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-94926}, pages = {97 -- 106}, year = {2015}, abstract = {I. Einf{\"u}hrung II. Die Kreaturw{\"u}rde im schweizerischen Recht - Entstehung und Konzeption III. Inhalt und Bedeutung der Kreaturw{\"u}rde IV. Die besondere Herausforderung: W{\"u}rde der Pflanze V. Kreaturw{\"u}rde und Menschenw{\"u}rde VI. Kreaturw{\"u}rde in der Gentechnologie VII. Kreaturw{\"u}rde im Tierschutz VIII. Reflexion}, language = {de} } @article{Schmitz2015, author = {Schmitz, Friederike}, title = {Tierschutz, Tierrechte oder Tierbefreiung?}, series = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, volume = {20}, journal = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, number = {2}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1434-2820}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-94912}, pages = {87 -- 96}, year = {2015}, abstract = {I. Einleitung II. Ethik III. Moralische Tierrechte? IV. Die Nutzung von Tieren V. Ethik und politische Theorie der Nutztierhaltung VI. Tierrechte oder Tierbefreiung?}, language = {de} } @article{Ladwig2015, author = {Ladwig, Bernd}, title = {Warum manche Tiere Rechte haben - und wir nicht die einzigen sind}, series = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, volume = {20}, journal = {MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen}, number = {2}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1434-2820}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-94900}, pages = {75 -- 86}, year = {2015}, abstract = {In diesem Text soll zweierlei gezeigt werden. Erstens, weil Menschen Rechte haben, gibt es wenigstens einige Tiere, die Rechte haben (I.). Zweitens, wir k{\"o}nnen die Rechte von Tieren nicht willk{\"u}rfrei auf die Art begrenzen, die wir selber bilden; Menschen sind nicht die einzigen Tiere, die Rechte haben (II.).}, language = {de} } @phdthesis{Bittermann2015, author = {Bittermann, Klaus}, title = {Semi-empirical sea-level modelling}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-93881}, school = {Universit{\"a}t Potsdam}, pages = {v, 88}, year = {2015}, abstract = {Semi-empirical sea-level models (SEMs) exploit physically motivated empirical relationships between global sea level and certain drivers, in the following global mean temperature. This model class evolved as a supplement to process-based models (Rahmstorf (2007)) which were unable to fully represent all relevant processes. They thus failed to capture past sea-level change (Rahmstorf et al. (2012)) and were thought likely to underestimate future sea-level rise. Semi-empirical models were found to be a fast and useful tool for exploring the uncertainties in future sea-level rise, consistently giving significantly higher projections than process-based models. In the following different aspects of semi-empirical sea-level modelling have been studied. Models were first validated using various data sets of global sea level and temperature. SEMs were then used on the glacier contribution to sea level, and to infer past global temperature from sea-level data via inverse modelling. Periods studied encompass the instrumental period, covered by tide gauges (starting 1700 CE (Common Era) in Amsterdam) and satellites (first launched in 1992 CE), the era from 1000 BCE (before CE) to present, and the full length of the Holocene (using proxy data). Accordingly different data, model formulations and implementations have been used. It could be shown in Bittermann et al. (2013) that SEMs correctly predict 20th century sea-level when calibrated with data until 1900 CE. SEMs also turned out to give better predictions than the Intergovernmental Panel on Climate Change (IPCC) 4th assessment report (AR4, IPCC (2007)) models, for the period from 1961-2003 CE. With the first multi-proxy reconstruction of global sea-level as input, estimate of the human-induced component of modern sea-level change and projections of future sea-level rise were calculated (Kopp et al. (2016)). It turned out with 90\% confidence that more than 40 \% of the observed 20th century sea-level rise is indeed anthropogenic. With the new semi-empirical and IPCC (2013) 5th assessment report (AR5) projections the gap between SEM and process-based model projections closes, giving higher credibility to both. Combining all scenarios, from strong mitigation to business as usual, a global sea-level rise of 28-131 cm relative to 2000 CE, is projected with 90\% confidence. The decision for a low carbon pathway could halve the expected global sea-level rise by 2100 CE. Present day temperature and thus sea level are driven by the globally acting greenhouse-gas forcing. Unlike that, the Milankovich forcing, acting on Holocene timescales, results mainly in a northern-hemisphere temperature change. Therefore a semi-empirical model can be driven with northernhemisphere temperatures, which makes it possible to model the main subcomponent of sea-level change over this period. It showed that an additional positive constant rate of the order of the estimated Antarctic sea-level contribution is then required to explain the sea-level evolution over the Holocene. Thus the global sea level, following the climatic optimum, can be interpreted as the sum of a temperature induced sea-level drop and a positive long-term contribution, likely an ongoing response to deglaciation coming from Antarctica.}, language = {en} } @masterthesis{Kreibich2015, type = {Bachelor Thesis}, author = {Kreibich, Christoph}, title = {Erucas{\"a}ure in Brassica napus L. - ein ph{\"a}notypisches Merkmal im Genetikunterricht und ihr Nachweis mit Hilfe von Papierchromatographie}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-93341}, school = {Universit{\"a}t Potsdam}, pages = {II, 35}, year = {2015}, abstract = {Erucic acid is a mono-unsaturated fatty acid that is naturally found in large quantities in seeds of rapeseed (Brassica napus L.) and other Brassica species. Erucic acid represents an important resource in the industry, however, due to its injurious effects on the heart muscle, this fatty acid is considered to be nutritionally harmful. Therefore, new high quality rapeseed cultivars were bred in order to eliminate the content of erucic acid in rapeseed oil at the end of the 20th century. In the breeding process, paper chromatography was used for the distinction between seeds with high and low content of erucic acid. Here, this outdated method was revised and optimized for educational purposes. By means of paper chromatography the qualitative content of erucic acid and four other unsaturated fatty acids was analyzed in rapeseed and linseed. The character 'erucic acid content', determined by two additive genes, can be used as a practical example of a phenotypic marker in school lessons, for instance, in the course 'achievement of plant breeding'. Thus, this qualitative analysis of erucic acid content enables the teacher to connect classical genetics with modern methods of plant genetics.}, language = {de} } @book{OPUS4-8996, title = {Auswertung der Befragung zum Einsatz mobiler internetf{\"a}higer Ger{\"a}te durch Studierende an der Universit{\"a}t Potsdam}, number = {3}, editor = {Bereich Lehre und Medien, Zentrum f{\"u}r Qualit{\"a}tsentwicklung in Lehre und Studium}, issn = {2199-6520}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89966}, publisher = {Universit{\"a}t Potsdam}, pages = {ii, 20}, year = {2015}, abstract = {Welche mobilen internetf{\"a}higen Ger{\"a}te Studierende der Universit{\"a}t Potsdam nutzen und in welchem Rahmen dies geschieht, soll die hiermit vorgelegte Untersuchung aufzeigen. Im Sommersemester 2014 hat die AG eLEARNiNG der Universit{\"a}t Potsdam unter 290 Studierenden unterschiedlicher Fachrichtungen eine Umfrage zum Umgang mobilen, internetf{\"a}higen Endger{\"a}ten durchgef{\"u}hrt, um das E-Learning-Angebot den Bed{\"u}rfnissen der Studierenden entsprechend anpassen und weiterentwickeln zu k{\"o}nnen. Um einen Vergleich zwischen verschiedenen Studieng{\"a}ngen und -standorten ziehen zu k{\"o}nnen, wurde die Befragung mit Studierenden in Veranstaltungen mit kontr{\"a}ren Parametern (Studienfach, Semesterzahl, Universit{\"a}tsstandort) durchgef{\"u}hrt.}, language = {de} } @phdthesis{Bojahr2015, author = {Bojahr, Juliane}, title = {Aktivierung des humanen S{\"u}ßgeschmacksrezeptors im zellbasierten Testsystem}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-93331}, school = {Universit{\"a}t Potsdam}, pages = {XIII, 174}, year = {2015}, abstract = {Zellbasierte heterologe Expressionssysteme bieten ein einfaches und schnelles Verfahren, um neue S{\"u}ßstoffe oder S{\"u}ßverst{\"a}rker zu finden. Unter Verwendung eines solchen Testsystems, konnte ich in Zusammenarbeit mit der Symrise AG, Holzminden und dem Institut f{\"u}r Pflanzenbiochemie in Halle/Saale die vietnamesische Pflanze Mycetia balansae als Quelle eines neuen S{\"u}ßstoffs identifizieren. Deren Hauptkomponenten, genannt Balansine, aktivieren spezifisch den humanen S{\"u}ßrezeptor. Chim{\"a}re Rezeptoren zeigten, dass die amino-terminalen Dom{\"a}nen der S{\"u}ßrezeptoruntereinheiten, welche ein Großteil der Liganden des S{\"u}ßrezeptors binden, f{\"u}r dessen Aktivierung durch Balansin A nicht notwendig sind. Voraussetzung f{\"u}r die Anwendung zellbasierter Testsysteme zum Auffinden neuer S{\"u}ßstoffe ist jedoch, dass s{\"u}ße Substanzen gesichert identifiziert werden, w{\"a}hrend nicht s{\"u}ße Substanzen zuverl{\"a}ssig keine Rezeptoraktivierung aufweisen. W{\"a}hrend in HEK293 TAS1R2 TAS1R3To Galpha15i3-Zellen S{\"u}ßrezeptoraktivierung gegen{\"u}ber nicht s{\"u}ß schmeckenden Substanzen beobachtet wurde, konnte mit den HEK293PEAKrapid Galpha15-Zellen ein zuverl{\"a}ssiges Testsystem identifiziert, welches den S{\"u}ßgeschmack der untersuchten Substanzen widerspiegelte. Es fanden sich keine Hinweise, dass akzessorische Proteine oder verwandte Rezeptoren des S{\"u}ßrezeptors das unterschiedliche Verhalten der Zellen verursachen. Es konnte gezeigt werden, dass die Verwendung unterschiedlicher G-Proteine die Signalamplituden des S{\"u}ßrezeptors beeinflusst, die Unterschiede zwischen den Zellsystemen jedoch nicht vollst{\"a}ndig erkl{\"a}rt. Keine der untersuchten Galpha-Proteinchim{\"a}ren spiegelte die intrinsische S{\"u}ße der Substanzen wider. Wenn auch nicht urs{\"a}chlich f{\"u}r die Diskrepanz zwischen S{\"u}ßrezeptoraktivierung in vitro und S{\"u}ßgeschmack in vivo, so weisen die Ergebnisse dieser Arbeit auf eine Interaktion der S{\"u}ßrezeptoruntereinheiten mit dem humanen Calcium-sensing Rezeptor hin. Vanillin und Ethylvanillin konnten als neue Agonisten des Calcium-sensing Rezeptors identifiziert werden. Wie die vorliegende Arbeit zeigt, k{\"o}nnen sich kleine Unterschiede im Zellhintergrund deutlich auf die Funktionsweise heterolog exprimierter Rezeptoren auswirken. Dies zeigt wie wichtig die Wahl der Zellen f{\"u}r solche Screeningsysteme ist.}, language = {de} } @misc{SicardKappelJosephsetal.2015, author = {Sicard, Adrien and Kappel, Christian and Josephs, Emily B. and Wha Lee, Young and Marona, Cindy and Stinchcombe, John R. and Wright, Stephen I. and Lenhard, Michael}, title = {Divergent sorting of a balanced ancestral polymorphism underlies the establishment of gene-flow barriers in Capsella}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-93568}, year = {2015}, abstract = {In the Bateson-Dobzhansky-Muller model of genetic incompatibilities post-zygotic gene-flow barriers arise by fixation of novel alleles at interacting loci in separated populations. Many such incompatibilities are polymorphic in plants, implying an important role for genetic drift or balancing selection in their origin and evolution. Here we show that NPR1 and RPP5 loci cause a genetic incompatibility between the incipient species Capsella grandiflora and C. rubella, and the more distantly related C. rubella and C. orientalis. The incompatible RPP5 allele results from a mutation in C. rubella, while the incompatible NPR1 allele is frequent in the ancestral C. grandiflora. Compatible and incompatible NPR1 haplotypes are maintained by balancing selection in C. grandiflora, and were divergently sorted into the derived C. rubella and C. orientalis. Thus, by maintaining differentiated alleles at high frequencies, balancing selection on ancestral polymorphisms can facilitate establishing gene-flow barriers between derived populations through lineage sorting of the alternative alleles.}, language = {en} } @misc{ValentePhillimoreEtienne2015, author = {Valente, Luis M. and Phillimore, Albert B. and Etienne, Rampal S.}, title = {Equilibrium and non-equilibrium dynamics simultaneously operate in the Gal{\´a}pagos islands}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-93525}, pages = {9}, year = {2015}, abstract = {Island biotas emerge from the interplay between colonisation, speciation and extinction and are often the scene of spectacular adaptive radiations. A common assumption is that insular diversity is at a dynamic equilibrium, but for remote islands, such as Hawaii or Gal{\´a}pagos, this idea remains untested. Here, we reconstruct the temporal accumulation of terrestrial bird species of the Gal{\´a}pagos using a novel phylogenetic method that estimates rates of biota assembly for an entire community. We show that species richness on the archipelago is in an ascending phase and does not tend towards equilibrium. The majority of the avifauna diversifies at a slow rate, without detectable ecological limits. However, Darwin's finches form an exception: they rapidly reach a carrying capacity and subsequently follow a coalescent-like diversification process. Together, these results suggest that avian diversity of remote islands is rising, and challenge the mutual exclusivity of the non-equilibrium and equilibrium ecological paradigms.}, language = {en} } @phdthesis{Soulie2015, author = {Souli{\´e}, Virginie}, title = {Sessile droplets of salt solutions on inert and metallic surfaces}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90329}, school = {Universit{\"a}t Potsdam}, year = {2015}, abstract = {In this thesis we investigate the evaporation behaviour of sessile droplets of aqueous saline solutions on planar inert and metallic surfaces and characterise the corrosion phenomenon for iron surfaces. First we study the evaporation behaviour of sessile salty droplets on inert surfaces for a wide range of salt concentrations, relative humidities, droplet sizes and contact angles. Our study reveals the range of validity of the well-accepted diffusion-controlled evaporation model and highlights the impact of salt concentration (surface tension) gradients driven Marangoni flows on the evaporation behaviour and the subsequent salty deposit patterns. Furthermore we study the spatial-temporal evolution of sessile droplets from saline solutions on metallic surfaces. In contrast to the simple, generally accepted Evans droplet model, we show that the corrosion spreads ahead of the macroscopic contact line with a peripheral film. The three-phase contact line is destabilized by surface tension gradients induced by ionic composition changes during the course of the corrosion process and migration of cations towards the droplet perimeter. Finally we investigate the corrosion behaviour under drying salty sessile droplets on metallic surfaces. The corrosion process, in particular the location of anodic and cathodic activities over the footprint droplet area is correlated to the spatial distribution of the salt inside the drying droplet.}, language = {en} } @phdthesis{Boettle2015, author = {B{\"o}ttle, Markus}, title = {Coastal floods in view of sea level rise}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-91074}, school = {Universit{\"a}t Potsdam}, pages = {xiii, 111}, year = {2015}, abstract = {The sea level rise induced intensification of coastal floods is a serious threat to many regions in proximity to the ocean. Although severe flood events are rare they can entail enormous damage costs, especially when built-up areas are inundated. Fortunately, the mean sea level advances slowly and there is enough time for society to adapt to the changing environment. Most commonly, this is achieved by the construction or reinforcement of flood defence measures such as dykes or sea walls but also land use and disaster management are widely discussed options. Overall, albeit the projection of sea level rise impacts and the elaboration of adequate response strategies is amongst the most prominent topics in climate impact research, global damage estimates are vague and mostly rely on the same assessment models. The thesis at hand contributes to this issue by presenting a distinctive approach which facilitates large scale assessments as well as the comparability of results across regions. Moreover, we aim to improve the general understanding of the interplay between mean sea level rise, adaptation, and coastal flood damage. Our undertaking is based on two basic building blocks. Firstly, we make use of macroscopic flood-damage functions, i.e. damage functions that provide the total monetary damage within a delineated region (e.g. a city) caused by a flood of certain magnitude. After introducing a systematic methodology for the automatised derivation of such functions, we apply it to a total of 140 European cities and obtain a large set of damage curves utilisable for individual as well as comparative damage assessments. By scrutinising the resulting curves, we are further able to characterise the slope of the damage functions by means of a functional model. The proposed function has in general a sigmoidal shape but exhibits a power law increase for the relevant range of flood levels and we detect an average exponent of 3.4 for the considered cities. This finding represents an essential input for subsequent elaborations on the general interrelations of involved quantities. The second basic element of this work is extreme value theory which is employed to characterise the occurrence of flood events and in conjunction with a damage function provides the probability distribution of the annual damage in the area under study. The resulting approach is highly flexible as it assumes non-stationarity in all relevant parameters and can be easily applied to arbitrary regions, sea level, and adaptation scenarios. For instance, we find a doubling of expected flood damage in the city of Copenhagen for a rise in mean sea levels of only 11 cm. By following more general considerations, we succeed in deducing surprisingly simple functional expressions to describe the damage behaviour in a given region for varying mean sea levels, changing storm intensities, and supposed protection levels. We are thus able to project future flood damage by means of a reduced set of parameters, namely the aforementioned damage function exponent and the extreme value parameters. Similar examinations are carried out to quantify the aleatory uncertainty involved in these projections. In this regard, a decrease of (relative) uncertainty with rising mean sea levels is detected. Beyond that, we demonstrate how potential adaptation measures can be assessed in terms of a Cost-Benefit Analysis. This is exemplified by the Danish case study of Kalundborg, where amortisation times for a planned investment are estimated for several sea level scenarios and discount rates.}, language = {en} } @phdthesis{Schnitzler2015, author = {Schnitzler, Carola}, title = {Phonologische Bewusstheit und Schriftspracherwerb}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-92370}, school = {Universit{\"a}t Potsdam}, pages = {IV, 52}, year = {2015}, abstract = {Die vorliegende Arbeit besch{\"a}ftigt sich mit der Fragestellung, inwieweit die Integrit{\"a}t der phonologischen Sprachverarbeitung f{\"u}r den erfolgreichen Schriftspracherwerb bei deutschsprachigen Kindern relevant ist. Hierbei bilden F{\"a}higkeiten zur phonologischen Bewusstheit (PhB) den Schwerpunkt. Der erfolgreiche Schriftspracherwerb ist nicht nur f{\"u}r den Bildungserfolg mit den damit verbundenen beruflichen und sozio‑{\"o}konomischen Perspektiven wichtig, sondern auch f{\"u}r die aktive Teilhabe am sozialen und kulturellen Leben in unserer Gesellschaft. Die Bestandteile dieser publikationsbasierten Dissertation sind eine Monographie (Schnitzler, 2008), ein Beitrag in einem Sammelwerk (Schnitzler, 2013) sowie zwei Zeitschriftenartikel (Schnitzler, 2014, 2015). Die ersten beiden Publikationen besch{\"a}ftigen sich mit der Entwicklung der PhB sowie Zusammenh{\"a}ngen zwischen PhB und Schriftsprachfertigkeiten. Die beiden Zeitschriftenartikel besch{\"a}ftigen sich mit dem LRS‑Risiko deutschsprachiger Kinder, die im Vorschulalter aufgrund phonologischer Aussprachest{\"o}rungen (PhAS) logop{\"a}disch behandelt werden. Hierzu wurden in Schnitzler (2015) die Ergebnisse einer selbst durchgef{\"u}hrten Studie dargestellt. In dieser Studie wurden m{\"o}gliche Einfl{\"u}sse zus{\"a}tzlicher nicht‑phonologischer Symptome und der Art der phonologischen Aussprachest{\"o}rung kontrolliert. Die Ergebnisse weisen darauf hin, dass zum Schulbeginn und w{\"a}hrend der Schuleingangsphase genau beobachtet werden sollte, ob Kinder {\"u}ber altersentsprechende F{\"a}higkeiten zur PhB verf{\"u}gen und ob sie diese segmental‑phonologischen Wissensbest{\"a}nde bewusst aktivieren und beim Lesen und Schreiben effizient nutzen. Dies gilt insbesondere f{\"u}r Kinder, f{\"u}r die ein erh{\"o}htes LRS‑Risiko besteht. Verf{\"u}gen Kinder zu dieser Zeit {\"u}ber unzureichend spezifizierte phonologische Repr{\"a}sentationen, ist eine fr{\"u}hzeitige Intervention im Sinne einer Pr{\"a}vention von LRS angezeigt.}, language = {de} } @phdthesis{Obu2015, author = {Obu, Jaroslav}, title = {Effect of mass wasting on soil organic carbon storage and coastal erosion in permafrost environments}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90599}, school = {Universit{\"a}t Potsdam}, pages = {iii, 93}, year = {2015}, abstract = {Accelerated permafrost thaw under the warming Arctic climate can have a significant impact on Arctic landscapes. Areas underlain by permafrost store high amounts of soil organic carbon (SOC). Permafrost disturbances may contribute to increased release of carbon dioxide and methane to the atmosphere. Coastal erosion, amplified through a decrease in Arctic sea-ice extent, may also mobilise SOC from permafrost. Large expanses of permafrost affected land are characterised by intense mass-wasting processes such as solifluction, active-layer detachments and retrogressive thaw slumping. Our aim is to assess the influence of mass wasting on SOC storage and coastal erosion. We studied SOC storage on Herschel Island by analysing active-layer and permafrost samples, and compared non-disturbed sites to those characterised by mass wasting. Mass-wasting sites showed decreased SOC storage and material compaction, whereas sites characterised by material accumulation showed increased storage. The SOC storage on Herschel Island is also significantly correlated to catenary position and other slope characteristics. We estimated SOC storage on Herschel Island to be 34.8 kg C m-2. This is comparable to similar environments in northwest Canada and Alaska. Coastal erosion was analysed using high resolution digital elevation models (DEMs). Two LIDAR scanning of the Yukon Coast were done in 2012 and 2013. Two DEMs with 1 m horizontal resolution were generated and used to analyse elevation changes along the coast. The results indicate considerable spatial variability in short-term coastline erosion and progradation. The high variability was related to the presence of mass-wasting processes. Erosion and deposition extremes were recorded where the retrogressive thaw slump (RTS) activity was most pronounced. Released sediment can be transported by longshore drift and affects not only the coastal processes in situ but also along adjacent coasts. We also calculated volumetric coastal erosion for Herschel Island by comparing a stereo-photogrammetrically derived DEM from 2004 with LIDAR DEMs. We compared this volumetric erosion to planimetric erosion, which was based on coastlines digitised from satellite imagery. We found a complex relationship between planimetric and volumetric coastal erosion, which we attribute to frequent occurrence of mass-wasting processes along the coasts. Our results suggest that volumetric erosion corresponds better with environmental forcing and is more suitable for the estimation of organic carbon fluxes than planimetric erosion. Mass wasting can decrease SOC storage by several mechanisms. Increased aeration following disturbance may increase microbial activity, which accelerates organic matter decomposition. New hydrological conditions that follow the mass wasting event can cause leaching of freshly exposed material. Organic rich material can also be directly removed into the sea or into a lake. On the other hand the accumulation of mobilised material can result in increased SOC storage. Mass-wasting related accumulations of mobilised material can significantly impact coastal erosion in situ or along the adjacent coast by longshore drift. Therefore, the coastline movement observations cannot completely resolve the actual sediment loss due to these temporary accumulations. The predicted increase of mass-wasting activity in the course of Arctic warming may increase SOC mobilisation and coastal erosion induced carbon fluxes.}, language = {en} } @misc{BothevanderLindeRichteretal.2015, author = {Bothe, Jan Philipp and van der Linde, Benjamin and Richter, Susan and Rogger, Philippe and Petzold, Sara and Pranghofer, Sebastian}, title = {Milit{\"a}r und Gesellschaft in der Fr{\"u}hen Neuzeit}, volume = {18}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1617-9722}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-79680}, year = {2015}, abstract = {Der Arbeitskreis Milit{\"a}r und Gesellschaft in der Fr{\"u}hen Neuzeit e. V. wurde im Fr{\"u}hjahr 1995 gegr{\"u}ndet. Er hat es sich zur Aufgabe gemacht, die Erforschung des Milit{\"a}rs im Rahmen der fr{\"u}hneuzeitlichen Geschichte zu bef{\"o}rdern und zugleich das Bewusstsein der Fr{\"u}hneuzeit-HistorikerInnen f{\"u}r die Bedeutung des Milit{\"a}rs in all seinen Funktionen zu wecken. Das Milit{\"a}r steht somit als soziale Gruppe selbst im Mittelpunkt der Aktivit{\"a}ten des Arbeitskreises, wird aber auch in seinen Wirkungen und Repr{\"a}sentationen thematisiert. Ziel ist es, die Rolle des Milit{\"a}rs als Teil der fr{\"u}hneuzeitlichen Gesellschaft umfassend herauszuarbeiten und zu w{\"u}rdigen. Insofern versteht der AMG seine Arbeit nicht nur als Beitrag zur Milit{\"a}rgeschichte, sondern vor allem als Beitrag zur Geschichte der Fr{\"u}hen Neuzeit insgesamt. Der Arbeitskreis bietet ein Diskussions- und Informationsforum durch die Organisation von Tagungen, die Herausgabe der Schriftenreihe ‚Herrschaft und soziale Systeme in der Fr{\"u}hen Neuzeit', die Zeitschrift ‚Milit{\"a}r und Gesellschaft in der Fr{\"u}hen Neuzeit' und die Mailingliste mil-fnz.}, language = {de} } @phdthesis{Prokhorov2015, author = {Prokhorov, Boris E.}, title = {High-latitude coupling processes between thermospheric circulation and solar wind driven magnetospheric currents and plasma convection}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-92353}, school = {Universit{\"a}t Potsdam}, pages = {117}, year = {2015}, abstract = {The high-latitudinal thermospheric processes driven by the solar wind and Interplanetary Magnetic Field (IMF) interaction with the Earth magnetosphere are highly variable parts of the complex dynamic plasma environment, which represent the coupled Magnetosphere - Ionosphere - Thermosphere (MIT) system. The solar wind and IMF interactions transfer energy to the MIT system via reconnection processes at the magnetopause. The Field Aligned Currents (FACs) constitute the energetic links between the magnetosphere and the Earth ionosphere. The MIT system depends on the highly variable solar wind conditions, in particular on changes of the strength and orientation of the IMF. In my thesis, I perform an investigation on the physical background of the complex MIT system using the global physical - numerical, three-dimensional, time-dependent and self-consistent Upper Atmosphere Model (UAM). This model describes the thermosphere, ionosphere, plasmasphere and inner magnetosphere as well as the electrodynamics of the coupled MIT system for the altitudinal range from 80 (60) km up to the 15 Earth radii. In the present study, I developed and investigated several variants of the high-latitudinal electrodynamic coupling by including the IMF dependence of FACs into the UAM model. For testing, the various variants were applied to simulations of the coupled MIT system for different seasons, geomagnetic activities, various solar wind and IMF conditions. Additionally, these variants of the theoretical model with the IMF dependence were compared with global empirical models. The modelling results for the most important thermospheric parameters like neutral wind and mass density were compared with satellite measurements. The variants of the UAM model with IMF dependence show a good agreement with the satellite observations. In comparison with the empirical models, the improved variants of the UAM model reproduce a more realistic meso-scale structures and dynamics of the coupled MIT system than the empirical models, in particular at high latitudes. The new configurations of the UAM model with IMF dependence contribute to the improvement of space weather prediction.}, language = {en} } @book{FelgentreffHirschfeldMillsteinetal.2015, author = {Felgentreff, Tim and Hirschfeld, Robert and Millstein, Todd and Borning, Alan}, title = {Babelsberg/RML}, number = {103}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-348-0}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-83826}, publisher = {Universit{\"a}t Potsdam}, pages = {68}, year = {2015}, abstract = {New programming language designs are often evaluated on concrete implementations. However, in order to draw conclusions about the language design from the evaluation of concrete programming languages, these implementations need to be verified against the formalism of the design. To that end, we also have to ensure that the design actually meets its stated goals. A useful tool for the latter has been to create an executable semantics from a formalism that can execute a test suite of examples. However, this mechanism so far did not allow to verify an implementation against the design. Babelsberg is a new design for a family of object-constraint languages. Recently, we have developed a formal semantics to clarify some issues in the design of those languages. Supplementing this work, we report here on how this formalism is turned into an executable operational semantics using the RML system. Furthermore, we show how we extended the executable semantics to create a framework that can generate test suites for the concrete Babelsberg implementations that provide traceability from the design to the language. Finally, we discuss how these test suites helped us find and correct mistakes in the Babelsberg implementation for JavaScript.}, language = {en} } @misc{OPUS4-9223, title = {Kentron : Journal zur Lehrerbildung}, number = {28}, issn = {1867-4720}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-92235}, year = {2015}, abstract = {Editorial (Dr. Roswitha Lohwaßer) ; Erwartungen und Ziele. Fragen der kentron-Redaktion an die Mitglieder der Versammlung des Zentrums f{\"u}r Lehrerbildung und Bildungsforschung (Prof. Dr. Bernd Meier, Prof. Dr. Agi Schr{\"u}nder, Prof. Dr. Andreas Borowski, Prof. Dr. Erin Gerlach, Matthias Schall, Prof. Dr. Martin Leubner, Prof. Dr. Bernd Schmidt) ; PSI - Potsdam. Professionalisierung - Schulpraktische Studien - Inklusion: Potsdamer Modell der Lehrerbildung (Dr. Jolanda Hermanns) ; Professionalisierung. Verbesserung des Professionswissens von Lehramtsstudierenden durch Integration von fachwissenschaftlichen und fachdidaktischen Ausbildungsanteilen (Dr. Ingrid Glowinksi) ; Schulpraktische Studien. St{\"a}rkung des Kompetenzerwerbs bei der Integration schulpraktischer Elemente (Prof. Dr. Andreas Borowski) ; Inklusion und Heterogenit{\"a}t (Prof. Dr. Antje Ehlert)}, language = {de} } @misc{OPUS4-9222, title = {Kentron : Journal zur Lehrerbildung}, number = {27}, issn = {1867-4720}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-92226}, year = {2015}, abstract = {Editorial (Dr. Roswitha Lohwaßer) ; Inklusion braucht Struktur. Impulse aus dem Response-to-Intervention-Modell f{\"u}r die Gestaltung eines inklusiven Wandels (Prof. Dr. Christian Huber) ; MoBas-TaPir-FeSch. Heterogenit{\"a}t und Inklusion an der Humanwissenschaftlichen Fakult{\"a}t (Prof. Dr. Barbara H{\"o}hle und Dr. Julia Festman) ; Kinder mit Lernst{\"o}rungen professionell begleiten. Was gebraucht und wer gebraucht wird (Beatrice Tr{\"u}eb, Marina Rottig) ; Sprachliches Denken und seine Bedeutung beim mathematischen Lernen (Dr. J{\"o}rg Kwapis) ; Konzeptionelle Ver{\"a}nderungen der schulpraktischen Studien im Rahmen des IEP. Status quo der Umsetzung und Ausblick (J{\"o}rn Simon) ; Meine Ausrichtung des Sachunterrichts (Prof. Dr. Hartmut Giest) ; Mehr Medienkompetenz in der Lehramtsausbildung (Christian Bleek und Cornelia Br{\"u}ckner) ; Phoniatrisches Gutachten. Sprecherziehung f{\"u}r zuk{\"u}nftige Lehrerinnen und Lehrer hat an der Universit{\"a}t Tradition (Katharina Paulke) ; Satzung f{\"u}r das Zentrums f{\"u}r Lehrerbildung und Bildungsforschung der Universit{\"a}t Potsdam}, language = {de} } @book{OttoPollakWerneretal.2015, author = {Otto, Philipp and Pollak, Jaqueline and Werner, Daniel and Wolff, Felix and Steinert, Bastian and Thamsen, Lauritz and Taeumel, Marcel and Lincke, Jens and Krahn, Robert and Ingalls, Daniel H. H. and Hirschfeld, Robert}, title = {Exploratives Erstellen von interaktiven Inhalten in einer dynamischen Umgebung​}, number = {101}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-346-6}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-83806}, publisher = {Universit{\"a}t Potsdam}, pages = {vii, 115}, year = {2015}, abstract = {Bei der Erstellung von Visualisierungen gibt es im Wesentlichen zwei Ans{\"a}tze. Zum einen k{\"o}nnen mit geringem Aufwand schnell Standarddiagramme erstellt werden. Zum anderen gibt es die M{\"o}glichkeit, individuelle und interaktive Visualisierungen zu programmieren. Dies ist jedoch mit einem deutlich h{\"o}heren Aufwand verbunden. Flower erm{\"o}glicht eine schnelle Erstellung individueller und interaktiver Visualisierungen, indem es den Entwicklungssprozess stark vereinfacht und die Nutzer bei den einzelnen Aktivit{\"a}ten wie dem Import und der Aufbereitung von Daten, deren Abbildung auf visuelle Elemente sowie der Integration von Interaktivit{\"a}t direkt unterst{\"u}tzt.}, language = {de} } @phdthesis{Koehler2015, author = {K{\"o}hler, Anke}, title = {Theoriebasierte Betreuung des Schulpraktikums im Lehramtsstudium Englisch}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-91531}, school = {Universit{\"a}t Potsdam}, year = {2015}, abstract = {Der Beitrag der Dissertation „Theoriebasierte Betreuung vom Schulpraktikum im Lehramtsstudium Englisch" zum wissenschaftlichen Diskurs liegt in der Verbindung von Theoriebereichen der Professionalisierungsforschung und angewandten Linguistik mit Untersuchungen zur hochschuldidaktischen Begleitung und Betreuung im ersten Unterrichtspraktikum des Lehramtsstudiums, dem fachdidaktischen Tagespraktikum, an der Universit{\"a}t Potsdam. Ein interaktionsanalytisches Vorgehen wurde eingesetzt zur Weiterentwicklung des hochschuldidaktischen Settings einer disziplinenverbindenden, fachwissenschaftlichen Begleitung von Praktika im komplexen Kontext Schule. Die Implementierung entsprechender Formate ins regul{\"a}re Studium wurde in einer {\"u}ber drei Jahre angelegten iterativen Studie turnusm{\"a}ßig evaluiert.}, language = {de} } @phdthesis{Aich2015, author = {Aich, Valentin}, title = {Floods in the Niger River Basin in the face of global change}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-91577}, school = {Universit{\"a}t Potsdam}, pages = {xxi, 275}, year = {2015}, abstract = {In the last decade, the number and dimensions of catastrophic flooding events in the Niger River Basin (NRB) have markedly increased. Despite the devastating impact of the floods on the population and the mainly agriculturally based economy of the riverine nations, awareness of the hazards in policy and science is still low. The urgency of this topic and the existing research deficits are the motivation for the present dissertation. The thesis is an initial detailed assessment of the increasing flood risk in the NRB. The research strategy is based on four questions regarding (1) features of the change in flood risk, (2) reasons for the change in the flood regime, (3) expected changes of the flood regime given climate and land use changes, and (4) recommendations from previous analysis for reducing the flood risk in the NRB. The question examining the features of change in the flood regime is answered by means of statistical analysis. Trend, correlation, changepoint, and variance analyses show that, in addition to the factors exposure and vulnerability, the hazard itself has also increased significantly in the NRB, in accordance with the decadal climate pattern of West Africa. The northern arid and semi-arid parts of the NRB are those most affected by the changes. As potential reasons for the increase in flood magnitudes, climate and land use changes are attributed by means of a hypothesis-testing framework. Two different approaches, based on either data analysis or simulation, lead to similar results, showing that the influence of climatic changes is generally larger compared to that of land use changes. Only in the dry areas of the NRB is the influence of land use changes comparable to that of climatic alterations. Future changes of the flood regime are evaluated using modelling results. First ensembles of statistically and dynamically downscaled climate models based on different emission scenarios are analyzed. The models agree with a distinct increase in temperature. The precipitation signal, however, is not coherent. The climate scenarios are used to drive an eco-hydrological model. The influence of climatic changes on the flood regime is uncertain due to the unclear precipitation signal. Still, in general, higher flood peaks are expected. In a next step, effects of land use changes are integrated into the model. Different scenarios show that regreening might help to reduce flood peaks. In contrast, an expansion of agriculture might enhance the flood peaks in the NRB. Similarly to the analysis of observed changes in the flood regime, the impacts of climate- and land use changes for the future scenarios are also most severe in the dry areas of the NRB. In order to answer the final research question, the results of the above analysis are integrated into a range of recommendations for science and policy on how to reduce flood risk in the NRB. The main recommendations include a stronger consideration of the enormous natural climate variability in the NRB and a focus on so called "no-regret" adaptation strategies which account for high uncertainty, as well as a stronger consideration of regional differences. Regarding the prevention and mitigation of catastrophic flooding, the most vulnerable and sensitive areas in the basin, the arid and semi-arid Sahelian and Sudano-Sahelian regions, should be prioritized. Eventually, an active, science-based and science-guided flood policy is recommended. The enormous population growth in the NRB in connection with the expected deterioration of environmental and climatic conditions is likely to enhance the region´s vulnerability to flooding. A smart and sustainable flood policy can help mitigate these negative impacts of flooding on the development of riverine societies in West Africa.}, language = {en} } @phdthesis{Liebrich2015, author = {Liebrich, Marietta}, title = {Einfluss von Prozessoptimierungen auf die mikrobielle Diversit{\"a}t und die Effizienz der Gasbildung in Co-Verg{\"a}rungsanlagen der Abfallwirtschaft}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-91066}, school = {Universit{\"a}t Potsdam}, pages = {VII, 102}, year = {2015}, abstract = {Im Hinblick auf die Problematik der Umweltverschmutzung durch die Nutzung fossiler Brennstoffe ist es n{\"o}tig, eine langfristig stabile und umweltfreundliche Energieversorgung zu gew{\"a}hrleisten. Eine M{\"o}glichkeit, den Energiebedarf CO2-neutral zu decken, ist die Nutzung von Biogas. Hierbei spielt der Einsatz von biogenen Reststoffen, die durch einen hohen Anteil an Kohlenhydraten, Fetten und Proteinen gekennzeichnet sind und daher ein hohes Biogaspotential besitzen, eine wichtige Rolle. Voraussetzung f{\"u}r die Effizienz und Rentabilit{\"a}t solcher Anlagen ist u. a. ein stabiler Gasbildungsprozess. Da bisher noch nicht alle Aspekte der Biogasbildung vollst{\"a}ndig verstanden sind, werden die Anlagen oft nicht optimal ausgelastet, um Prozessst{\"o}rungen wie z. B. {\"U}bers{\"a}uerung zu vermeiden. Um dennoch auftretende Prozessst{\"o}rungen zu beheben, k{\"o}nnen unterschiedliche Maßnahmen durchgef{\"u}hrt werden. Neben der Senkung der Raumbelastung, ist es m{\"o}glich, den pH-Wert durch die Zugabe von Natronlauge oder Calciumoxid anzuheben. In der vorliegenden Arbeit wurden sowohl Prozessst{\"o}rungen als auch Prozessregenerierungen an einer großtechnischen Biogasanlage und in Laborversuchen untersucht. Dabei galt es, neben den physikalischen und chemischen Parametern, die mikrobielle Bioz{\"o}nose mit Hilfe des genetischen Fingerprintings zu charakterisieren und {\"A}nderungen zu detektieren. W{\"a}hrend der Prozessregenerierungen wurden nach der Zugabe von CaO Ver{\"a}nderungen des G{\"a}rrestes beobachtet. Es bildeten sich Pellets, die im Hinblick auf ihre Funktion f{\"u}r die Prozessregenerierung und die Prozessstabilit{\"a}t molekularbiologisch und mikroskopisch untersucht wurden. Es wurde weiterhin der Frage nachgegangen, welche Rolle die Mikroorganismen bei der Entstehung der Pellets spielen. Die vor allem aus Calcium und Fetts{\"a}uren bestehenden Pellets dienten als Aufwuchsfl{\"a}chen f{\"u}r verschiedene Mikroorganismen. Die Bildung von Biofilmen, wie sie auf und in den Pellets nachgewiesen wurde, bot f{\"u}r Mikroorganismen einen Schutz vor negativen Umwelteinfl{\"u}ssen wie z. B. hohe Propions{\"a}urekonzentrationen. Unter diesen g{\"u}nstigen Bedingungen war die Bildung von Biogas auch unter hohen Wasserstoffpartialdr{\"u}cken, die den Abbau von Propions{\"a}ure hemmten, m{\"o}glich. Als Indikator f{\"u}r bessere Lebensbedingungen wurde im Laborversuch ein Methanoculleus receptaculi-verwandter Organismus identifiziert. Dieses methanogene Archaeon wurde im Pellet nachgewiesen, w{\"a}hrend es im G{\"a}rrest erst nach der Prozessregenerierung detektiert wurde. Der Nachweis eines im Vergleich zum umgebenden G{\"a}rrest h{\"o}heren Anteils an Archaeen im Kern der Pellets sowie von Biofilmen/EPS, verschiedenen Phosphatsalzen und schwerl{\"o}slichen Calciumsalzen zeigte, dass sowohl Pr{\"a}zipitation und Adsorption als auch Degradation von LCFA dazu f{\"u}hren, dass deren Konzentration im fl{\"u}ssigen G{\"a}rrest gesenkt wird. Dadurch nimmt die Hemmung auf die Bioz{\"o}nose ab und die Biogasbildungsrate steigt. Daher ist der Abbau der Fetts{\"a}uren auch bei einem niedrigen pH-Wert und unter hohen Wasserstoffpartialdr{\"u}cken m{\"o}glich und der Biogasbildungsprozess ist langfristig stabil. Die Bildung von Pellets unterst{\"u}tzt die Prozessstabilit{\"a}t, sofern diese nicht zu groß werden und dann u. a. die Durchmischung behindern und den Ablauf verstopfen. Nach erfolgreicher Prozessstabilisierung wurden keine Pellets im G{\"a}rrest beobachtet. Der Abbau des organischen Materials wurde sowohl durch die steigende Calciumkonzentration als auch die steigende Gasproduktion angezeigt.}, language = {de} } @phdthesis{Schroeder2015, author = {Schr{\"o}der, Sarah}, title = {Modelling surface evolution coupled with tectonics}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90385}, school = {Universit{\"a}t Potsdam}, pages = {viii, 129}, year = {2015}, abstract = {This study presents the development of 1D and 2D Surface Evolution Codes (SECs) and their coupling to any lithospheric-scale (thermo-)mechanical code with a quadrilateral structured surface mesh. Both SECs involve diffusion as approach for hillslope processes and the stream power law to reflect riverbed incision. The 1D SEC settles sediment that was produced by fluvial incision in the appropriate minimum, while the supply-limited 2D SEC DANSER uses a fast filling algorithm to model sedimantation. It is based on a cellular automaton. A slope-dependent factor in the sediment flux extends the diffusion equation to nonlinear diffusion. The discharge accumulation is achieved with the D8-algorithm and an improved drainage accumulation routine. Lateral incision enhances the incision's modelling. Following empirical laws, it incises channels of several cells width. The coupling method enables different temporal and spatial resolutions of the SEC and the thermo-mechanical code. It transfers vertical as well as horizontal displacements to the surface model. A weighted smoothing of the 3D surface displacements is implemented. The smoothed displacement vectors transmit the deformation by bilinear interpolation to the surface model. These interpolation methods ensure mass conservation in both directions and prevent the two surfaces from drifting apart. The presented applications refer to the evolution of the Pamir orogen. A calibration of DANSER's parameters with geomorphological data and a DEM as initial topography highlights the advantage of lateral incision. Preserving the channel width and reflecting incision peaks in narrow channels, this closes the huge gap between current orogen-scale incision models and observed topographies. River capturing models in a system of fault-bounded block rotations reaffirm the importance of the lateral incision routine for capturing events with channel initiation. The models show a low probability of river capturings with large deflection angles. While the probability of river capturing is directly depending on the uplift rate, the erodibility inside of a dip-slip fault speeds up headward erosion along the fault: The model's capturing speed increases within a fault. Coupling DANSER with the thermo-mechanical code SLIM 3D emphasizes the versatility of the SEC. While DANSER has minor influence on the lithospheric evolution of an indenter model, the brittle surface deformation is strongly affected by its sedimentation, widening a basin in between two forming orogens and also the southern part of the southern orogen to south, east and west.}, language = {en} } @phdthesis{Kniepert2015, author = {Kniepert, Juliane}, title = {Correlation between dynamic parameters and device performance of organic solar cells}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90087}, school = {Universit{\"a}t Potsdam}, pages = {129}, year = {2015}, abstract = {Organic bulk heterojunction (BHJ) solar cells based on polymer:fullerene blends are a promising alternative for a low-cost solar energy conversion. Despite significant improvements of the power conversion efficiency in recent years, the fundamental working principles of these devices are yet not fully understood. In general, the current output of organic solar cells is determined by the generation of free charge carriers upon light absorption and their transport to the electrodes in competition to the loss of charge carriers due to recombination. The object of this thesis is to provide a comprehensive understanding of the dynamic processes and physical parameters determining the performance. A new approach for analyzing the characteristic current-voltage output was developed comprising the experimental determination of the efficiencies of charge carrier generation, recombination and transport, combined with numerical device simulations. Central issues at the beginning of this work were the influence of an electric field on the free carrier generation process and the contribution of generation, recombination and transport to the current-voltage characteristics. An elegant way to directly measure the field dependence of the free carrier generation is the Time Delayed Collection Field (TDCF) method. In TDCF charge carriers are generated by a short laser pulse and subsequently extracted by a defined rectangular voltage pulse. A new setup was established with an improved time resolution compared to former reports in literature. It was found that charge generation is in general independent of the electric field, in contrast to the current view in literature and opposed to the expectations of the Braun-Onsager model that was commonly used to describe the charge generation process. Even in cases where the charge generation was found to be field-dependend, numerical modelling showed that this field-dependence is in general not capable to account for the voltage dependence of the photocurrent. This highlights the importance of efficient charge extraction in competition to non-geminate recombination, which is the second objective of the thesis. Therefore, two different techniques were combined to characterize the dynamics and efficiency of non-geminate recombination under device-relevant conditions. One new approach is to perform TDCF measurements with increasing delay between generation and extraction of charges. Thus, TDCF was used for the first time to measure charge carrier generation, recombination and transport with the same experimental setup. This excludes experimental errors due to different measurement and preparation conditions and demonstrates the strength of this technique. An analytic model for the description of TDCF transients was developed and revealed the experimental conditions for which reliable results can be obtained. In particular, it turned out that the \$RC\$ time of the setup which is mainly given by the sample geometry has a significant influence on the shape of the transients which has to be considered for correct data analysis. Secondly, a complementary method was applied to characterize charge carrier recombination under steady state bias and illumination, i.e. under realistic operating conditions. This approach relies on the precise determination of the steady state carrier densities established in the active layer. It turned out that current techniques were not sufficient to measure carrier densities with the necessary accuracy. Therefore, a new technique {Bias Assisted Charge Extraction} (BACE) was developed. Here, the charge carriers photogenerated under steady state illumination are extracted by applying a high reverse bias. The accelerated extraction compared to conventional charge extraction minimizes losses through non-geminate recombination and trapping during extraction. By performing numerical device simulations under steady state, conditions were established under which quantitative information on the dynamics can be retrieved from BACE measurements. The applied experimental techniques allowed to sensitively analyse and quantify geminate and non-geminate recombination losses along with charge transport in organic solar cells. A full analysis was exemplarily demonstrated for two prominent polymer-fullerene blends. The model system P3HT:PCBM spincast from chloroform (as prepared) exhibits poor power conversion efficiencies (PCE) on the order of 0.5\%, mainly caused by low fill factors (FF) and currents. It could be shown that the performance of these devices is limited by the hole transport and large bimolecular recombination (BMR) losses, while geminate recombination losses are insignificant. The low polymer crystallinity and poor interconnection between the polymer and fullerene domains leads to a hole mobility of the order of 10^-7 cm^2/Vs which is several orders of magnitude lower than the electron mobility in these devices. The concomitant build up of space charge hinders extraction of both electrons and holes and promotes bimolecular recombination losses. Thermal annealing of P3HT:PCBM blends directly after spin coating improves crystallinity and interconnection of the polymer and the fullerene phase and results in comparatively high electron and hole mobilities in the order of 10^-3 cm^2/Vs and 10^-4 cm^2/Vs, respectively. In addition, a coarsening of the domain sizes leads to a reduction of the BMR by one order of magnitude. High charge carrier mobilities and low recombination losses result in comparatively high FF (>65\%) and short circuit current (J_SC ≈ 10 mA/cm^2). The overall device performance (PCE ≈ 4\%) is only limited by a rather low spectral overlap of absorption and solar emission and a small V_OC, given by the energetics of the P3HT. From this point of view the combination of the low bandgap polymer PTB7 with PCBM is a promising approach. In BHJ solar cells, this polymer leads to a higher V_OC due to optimized energetics with PCBM. However, the J_SC in these (unoptimized) devices is similar to the J_SC in the optimized blend with P3HT and the FF is rather low (≈ 50\%). It turned out that the unoptimized PTB7:PCBM blends suffer from high BMR, a low electron mobility of the order of 10^-5 cm^2/Vs and geminate recombination losses due to field dependent charge carrier generation. The use of the solvent additive DIO optimizes the blend morphology, mainly by suppressing the formation of very large fullerene domains and by forming a more uniform structure of well interconnected donor and acceptor domains of the order of a few nanometers. Our analysis shows that this results in an increase of the electron mobility by about one order of magnitude (3 x 10^-4 cm^2/Vs), while BMR and geminate recombination losses are significantly reduced. In total these effects improve the J_SC (≈ 17 mA/cm^2) and the FF (> 70\%). In 2012 this polymer/fullerene combination resulted in a record PCE for a single junction OSC of 9.2\%. Remarkably, the numerical device simulations revealed that the specific shape of the J-V characteristics depends very sensitively to the variation of not only one, but all dynamic parameters. On the one hand this proves that the experimentally determined parameters, if leading to a good match between simulated and measured J-V curves, are realistic and reliable. On the other hand it also emphasizes the importance to consider all involved dynamic quantities, namely charge carrier generation, geminate and non-geminate recombination as well as electron and hole mobilities. The measurement or investigation of only a subset of these parameters as frequently found in literature will lead to an incomplete picture and possibly to misleading conclusions. Importantly, the comparison of the numerical device simulation employing the measured parameters and the experimental \$J-V\$ characteristics allows to identify loss channels and limitations of OSC. For example, it turned out that inefficient extraction of charge carriers is a criticical limitation factor that is often disobeyed. However, efficient and fast transport of charges becomes more and more important with the development of new low bandgap materials with very high internal quantum efficiencies. Likewise, due to moderate charge carrier mobilities, the active layer thicknesses of current high-performance devices are usually limited to around 100 nm. However, larger layer thicknesses would be more favourable with respect to higher current output and robustness of production. Newly designed donor materials should therefore at best show a high tendency to form crystalline structures, as observed in P3HT, combined with the optimized energetics and quantum efficiency of, for example, PTB7.}, language = {en} } @phdthesis{Wohlfarth2015, author = {Wohlfarth, Kai}, title = {PPP: zu Finanzierungsformen, Kapitalmarktrelevanz und {\"o}ffentlicher Verschuldung}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90216}, school = {Universit{\"a}t Potsdam}, pages = {X, 184}, year = {2015}, abstract = {Die vorliegende Arbeit thematisiert die Finanzierungsmodelle von Public-Private-Partnership-Projekten (PPP) und deren Refinanzierung durch die Kapitalgeber. Dabei wurden zwei zentrale Fragestellungen thematisiert. Erstens: F{\"u}hren PPP­Projekte zu einer Verschuldung der {\"o}ffentlichen Hand und sind sie entsprechend bei den Berechnungen der Konvergenzkriterien bzw. der Schulden- und Neuverschuldungsquoten zu ber{\"u}cksichtigen? Die zu pr{\"u}fende Arbeitshypothese geht von einer Verschuldung der {\"o}ffentlichen Hand in Folge von PPP-Projekten aus. Zweitens: Unterstellt wird eine bedeutsame Funktion von PPP f{\"u}r die Infrastrukturfinanzierung, wobei im Sinne einer Effizienzsteigerung die Passgenauigkeit beziehungsweise Konsistenz der haushaltsrechtlichen Regelungen mit den regulatorischen Vorgaben f{\"u}r die Kapitalgeber von PPP-Projekten analysiert wird. Diese Schnittstelle und die zur Generierung g{\"u}nstiger („kommunal{\"a}hnlicher") Finanzierungskonditionen notwendigen staatlichen Garantien bei PPP dr{\"a}ngt geradezu zu einem ordnungspolitischen Vergleich von Ans{\"a}tzen bzw. Projekten im Bereich PPP und in Cash-Flow-Kalk{\"u}len. Die Arbeit f{\"u}hrt mit einem gewissen gesamtwirtschaftlichen Fokus der PPP tief in die Analyse des Kapitalmarktes und der Bankenregulierung. Es erfolgt ein Vergleich der gedeckten Refinanzierungsinstrumente f{\"u}r PPP, die durch Forderungen besichert sind (Asset Backed Securities) und solche, die beispielsweise durch Forderungen gegen die {\"o}ffentliche Hand besichert sind (Covered Bonds). Letztere k{\"o}nnen auch grundpfandrechtlich gesichert sein. Hier setzt der Verfasser sp{\"a}ter seine Skizze eines „Infrastructure Covered Bonds" f{\"u}r die Finanzierung notwendiger Infrastrukturmaßnahmen nicht nur in Deutschland an, wobei das Wertpapier hier ausschließlich zur Finanzierung der Infrastruktur bei einem entsprechend neu zuschaffenden (Deckungs-) Registers begeben werden wird.}, language = {de} } @phdthesis{Helpa2015, author = {Helpa, Vanessa}, title = {Interplay between mineral reaction and deformation via structural defects}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90332}, school = {Universit{\"a}t Potsdam}, pages = {x, 104}, year = {2015}, abstract = {This thesis contains three experimental studies addressing the interplay between deformation and the mineral reaction between natural calcite and magnesite. The solid-solid mineral reaction between the two carbonates causes the formation of a magnesio-calcite precursor layer and a dolomite reaction rim in every experiment at isostatic annealing and deformation conditions. CHAPTER 1 briefly introduces general aspects concerning mineral reactions in nature and diffusion pathways for mass transport. Moreover, results of previous laboratory studies on the influence of deformation on mineral reactions are summarized. In addition, the main goals of this study are pointed out. In CHAPTER 2, the reaction between calcite and magnesite single crystals is examined at isostatic annealing conditions. Time series performed at a fixed temperature revealed a diffusion-controlled dolomite rim growth. Two microstructural domains could be identified characterized by palisade-shaped dolomite grains growing into the magnesite and granular dolomite growing towards calcite. A model was provided for the dolomite rim growth based on the counter-diffusion of CaO and MgO. All reaction products exhibited a characteristic crystallographic relationship with respect to the calcite reactant. Moreover, kinetic parameters of the mineral reaction were determined out of a temperature series at a fixed time. The main goal of the isostatic test series was to gain information about the microstructure evolution, kinetic parameters, chemical composition and texture development of the reaction products. The results were used as a reference to quantify the influence of deformation on the mineral reaction. CHAPTER 3 deals with the influence of non-isostatic deformation on dolomite and magnesio-calcite layer production between calcite and magnesite single crystals. Deformation was achieved by triaxial compression and by torsion. Triaxial compression up to 38 MPa axial stress at a fixed time showed no significant influence of stress and strain on dolomite formation. Time series conducted at a fixed stress yield no change in growth rates for dolomite and magnesio-calcite at low strains. Slightly larger magnesio-calcite growth rates were observed at strains above >0.1. High strains at similar stresses were caused by the activation of additional glide systems in the calcite single crystal and more mobile dislocations in the magnesio-calcite grains, providing fast diffusion pathways. In torsion experiments a gradual decrease in dolomite and magnesio-calcite layer thickness was observed at a critical shear strain. During deformation, crystallographic orientations of reaction products rearranged with respect to the external framework. A direct effect of the mineral reaction on deformation could not be recognized due to the relatively small reaction product widths. In CHAPTER 4, the influence of starting material microfabrics and the presence of water on the reaction kinetics was evaluated. In these experimental series polycrystalline material was in contact with single crystals or two polycrystalline materials were used as reactants. Isostatic annealing resulted in different dolomite and magnesio-calcite layer thicknesses, depending on starting material microfabrics. The reaction progress at the magnesite interface was faster with smaller magnesite grain size, because grain boundaries provided fast pathways for diffusion and multiple nucleation sites for dolomite formation. Deformation by triaxial compression and torsion yield lower dolomite rim thicknesses compared to annealed samples for the same time. This was caused by grain coarsening of polycrystalline magnesite during deformation. In contrast, magnesio-calcite layers tended to be larger during deformation, which triggered enhanced diffusion along grain boundaries. The presence of excess water had no significant influence on the reaction kinetics, at least if the reactants were single crystals. In CHAPTER 5 general conclusions about the interplay between deformation and the mineral reaction in the carbonate system are presented. Finally, CHAPTER 6 highlights possible future work in the carbonate system based on the results of this study.}, language = {en} } @misc{ThomasStadler2015, author = {Thomas, Linda and Stadler, Heike}, title = {Workflow zur Identifizierung von Publikationen f{\"u}r die Zweitver{\"o}ffentlichung}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-90377}, year = {2015}, abstract = {Verf{\"u}gbare Allianz- und Nationallizenzen k{\"o}nnen eine Open-Access-Komponente beinhalten. Diese r{\"a}umen den autorisierten Autoren oder Einrichtungen bestimmte Open-Access-Rechte zur Zweitver{\"o}ffentlichung ein. Vorhandene Lizenzrechte zur Realisierung des Gr{\"u}nen Weges k{\"o}nnen somit zuk{\"u}nftig verst{\"a}rkt genutzt werden. Dabei kann die Bibliothek eine aktive Rolle einnehmen. Pr{\"a}sentiert wird ein Workflow, der sich an der Checkliste f{\"u}r Repository-Manager orientiert. Sieben herausgearbeitete Schritte werden genannt und n{\"a}her erl{\"a}utert. An Beispielen wurde der Workflow getestet. Die Ergebnisse werden ebenfalls vorgestellt. Die Erweiterung des Workflows zur Identifizierung von Publikationen f{\"u}r die Zweitver{\"o}ffentlichung l{\"a}sst sich ggf. auch auf Creative-Commons-Lizenzen anwenden bzw. auf Zeitschriften, die keine Open-Access-Komponente haben.}, language = {de} } @phdthesis{Olszewska2015, author = {Olszewska, Agata}, title = {Forming magnetic chain with the help of biological organisms}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89767}, school = {Universit{\"a}t Potsdam}, pages = {101}, year = {2015}, abstract = {Magnetite nanoparticles and their assembly comprise a new area of development for new technologies. The magnetic particles can interact and assemble in chains or networks. Magnetotactic bacteria are one of the most interesting microorganisms, in which the assembly of nanoparticles occurs. These microorganisms are a heterogeneous group of gram negative prokaryotes, which all show the production of special magnetic organelles called magnetosomes, consisting of a magnetic nanoparticle, either magnetite (Fe3O4) or greigite (Fe3S4), embedded in a membrane. The chain is assembled along an actin-like scaffold made of MamK protein, which makes the magnetosomes to arrange in mechanically stable chains. The chains work as a compass needle in order to allow cells to orient and swim along the magnetic field of the Earth. The formation of magnetosomes is known to be controlled at the molecular level. The physico-chemical conditions of the surrounding environment also influence biomineralization. The work presented in this manuscript aims to understand how such external conditions, in particular the extracellular oxidation reduction potential (ORP) influence magnetite formation in the strain Magnetospirillum magneticum AMB-1. A controlled cultivation of the microorganism was developed in a bioreactor and the formation of magnetosomes was characterized. Different techniques have been applied in order to characterize the amount of iron taken up by the bacteria and in consequence the size of magnetosomes produced at different ORP conditions. By comparison of iron uptake, morphology of bacteria, size and amount of magnetosomes per cell at different ORP, the formation of magnetosomes was inhibited at ORP 0 mV, whereas reduced conditions, ORP - 500 mV facilitate biomineralization process. Self-assembly of magnetosomes occurring in magnetotactic bacteria became an inspiration to learn from nature and to construct nanoparticles assemblies by using the bacteriophage M13 as a template. The M13 bacteriophage is an 800 nm long filament with encapsulated single-stranded DNA that has been recently used as a scaffold for nanoparticle assembly. I constructed two types of assemblies based on bacteriophages and magnetic nanoparticles. A chain - like assembly was first formed where magnetite nanoparticles are attached along the phage filament. A sperm - like construct was also built with a magnetic head and a tail formed by phage filament. The controlled assembly of magnetite nanoparticles on the phage template was possible due to two different mechanism of nanoparticle assembly. The first one was based on the electrostatic interactions between positively charged polyethylenimine coated magnetite nanoparticles and negatively charged phages. The second phage -nanoparticle assembly was achieved by bioengineered recognition sites. A mCherry protein is displayed on the phage and is was used as a linker to a red binding nanobody (RBP) that is fused to the one of the proteins surrounding the magnetite crystal of a magnetosome. Both assemblies were actuated in water by an external magnetic field showing their swimming behavior and potentially enabling further usage of such structures for medical applications. The speed of the phage - nanoparticles assemblies are relatively slow when compared to those of microswimmers previously published. However, only the largest phage-magnetite assemblies could be imaged and it is therefore still unclear how fast these structures can be in their smaller version.}, language = {en} } @misc{SchwarzEtteBredekampetal.2015, author = {Schwarz, Ingo and Ette, Ottmar and Bredekamp, Horst and Bispinck-Roßbacher, Julia and Kraft, Tobias and Erdmann, Dominik and Weber, Jutta and Lenz, Markus Alexander and Blankenstein, David and Savoy, B{\´e}n{\´e}dicte and Faak, Margot}, title = {HiN : Alexander von Humboldt im Netz = Amerikanische Reisetageb{\"u}cher}, series = {HIN : Alexander von Humboldt im Netz ; international review for Humboldtian studies}, volume = {XVI}, journal = {HIN : Alexander von Humboldt im Netz ; international review for Humboldtian studies}, number = {31}, editor = {Ette, Ottmar and Knobloch, Eberhard}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1617-5239}, doi = {10.18443/hinvol16iss312015}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89032}, pages = {121}, year = {2015}, abstract = {Ingo Schwarz: „etwas hervorzubringen, was meines K{\"o}nigs und meines Vaterlandes werth sein kann" - Briefe von Alexander von Humboldt an Friedrich Wilhelm III., 1805 Ottmar Ette: Tras la huella de la vida. El proyecto de larga duraci{\´o}n „Centro Alejandro de Humboldt. Ciencia en movimiento" edita los apuntes transdisciplinarios de Humboldt Horst Bredekamp: Die Amerikanischen Reisetageb{\"u}cher: ein erster Zugang Julia Bispinck-Roßbacher: „Zwischen den Zeilen …" Zur kodikologischen Untersuchung der Amerikanischen Reisetageb{\"u}cher von Alexander von Humboldt Tobias Kraft: Humboldts Hefte. Geschichte und Gegenwart von Tagebuch-Forschung und -Rezeption Dominik Erdmann, Jutta Weber: Nachlassgeschichten - Bemerkungen zu Humboldts nachgelassenen Papieren in der Berliner Staatsbibliothek und der Biblioteka Jagiellońska Krakau Bewegte Systematik. Alexander von Humboldts „Amerikanische Reisetageb{\"u}cher" als Problemfelder der Literaturgeschichte und historischen Epistemologie Markus Alexander Lenz: Bewegte Systematik. Alexander von Humboldts „Amerikanische Reisetageb{\"u}cher" als Problemfelder der Literaturgeschichte und historischen Epistemologie David Blankenstein, B{\´e}n{\´e}dicte Savoy: Frontale Pr{\"a}senz - Zu einem unbekannten Portr{\"a}t Alexander von Humboldts im Besitz des franz{\"o}sischen Conseil d'{\´E}tat Margot Faak: Alexander von Humboldts Amerikareise}, language = {mul} } @article{Faak2015, author = {Faak, Margot}, title = {Alexander von Humboldts Amerikareise}, series = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, volume = {XVI}, journal = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, number = {31}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1617-5239}, doi = {10.18443/226}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89029}, pages = {115 -- 121}, year = {2015}, abstract = {F{\"u}r Margot Faak (1926-2015) Am 14. Juni 2015 starb unsere Kollegin Margot Faak im 89. Lebensjahr. Wir erinnern an sie mit Worten des Abschieds von Eberhard Knobloch und dem Wiederabdruck eines Aufsatzes aus ihrer Feder von 1999. Die Neuver{\"o}ffentlichung erfolgt mit freundlicher Genehmigung der Alexander von Humboldt-Stiftung. Der Text wurde in den Fußnoten durch einige aktuelle bibliographische und sachliche Angaben erg{\"a}nzt. HiN VII, 13 (2006) war Margot Faak zu ihrem 80. Geburtstag gewidmet. Das Heft enth{\"a}lt einen Lebenslauf und ein Verzeichnis ihrer Schriften. Berlin, Oktober 2015 Regina Mikosch und Ingo Schwarz}, language = {de} } @article{BlankensteinSavoy2015, author = {Blankenstein, David and Savoy, B{\´e}n{\´e}dicte}, title = {Frontale Pr{\"a}senz}, series = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, volume = {XVI}, journal = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, number = {31}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1617-5239}, doi = {10.18443/225}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89012}, pages = {107 -- 114}, year = {2015}, abstract = {Ein bislang unver{\"o}ffentlichtes Portr{\"a}t Alexander von Humboldts aus der Hand Fr{\´e}d{\´e}ric d'Houdetots, ein Sch{\"u}ler des Malers Jacques-Louis David, bereichert die Humboldt-Ikonographie um eine Darstellung, die den ber{\"u}hmten Reisenden und Gelehrten als jungen Mann, wenige Jahre nach seiner R{\"u}ckkehr aus Amerika zeigt - beeindruckend lebendig, fokussiert und pr{\"a}sent. Das 1807 w{\"a}hrend der Franzosenzeit in Berlin entstandene Portr{\"a}t verweist als Teil eines im Conseil d'{\´E}tat in Paris aufbewahrten Portr{\"a}t-Albums auf die Zirkel und Beziehungen, die sich in der besetzten preußischen Hauptstadt zwischen Besatzern, j{\"u}dischen Salonkreisen und der wissenschaftlichen Community gebildet haben, ein N{\"a}hrboden f{\"u}r den transnationalen Austausch von Vertretern einer jungen und vitalen Generation, die sich als echte Europ{\"a}er verstanden.}, language = {de} } @article{Lenz2015, author = {Lenz, Markus Alexander}, title = {Bewegte Systematik}, series = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, volume = {XVI}, journal = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, number = {31}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1617-5239}, doi = {10.18443/224}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89001}, pages = {80 -- 106}, year = {2015}, abstract = {Die Amerikanischen Reisetageb{\"u}cher stellen eine Herausforderung f{\"u}r die Erforschung historischer Epistemologie dar. Der vorliegende Aufsatz will ausgehend vom Scheitern einer eindeutigen gattungsgeschichtlichen Zuschreibung die Sonderstellung der B{\"a}nde als Instrumente der Erfahrung herausarbeiten, welche an der Schwelle zum 19. Jh. den ontologischen Optimismus sowie das methodische Tasten eines Wissenschaftlers, Schriftstellers und Forschungsreisenden in subjektbezogener Form zug{\"a}nglich machen. Gerade der multifunktionale Charakter der ‚Journale' als Log- bzw. Reisetageb{\"u}cher und Skizzenhefte, die noch weit entfernt von der Ordnung wissenschaftlichen Schreibens scheinen, lassen jene Voraussetzungen wissenschaftlicher Erkenntnisprozesse sichtbar werden, mithilfe derer Humboldt innerhalb der kantschen Koordinaten Raum und Zeit einen ‚Rhythmus' situativ verarbeiteter Natur- und Welterfahrung in ein dynamisches Speichermedium einfließen l{\"a}sst.}, language = {de} } @article{ErdmannWeber2015, author = {Erdmann, Dominik and Weber, Jutta}, title = {Nachlassgeschichten}, series = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, volume = {XVI}, journal = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, number = {31}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1617-5239}, doi = {10.18443/223}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88997}, pages = {60 -- 79}, year = {2015}, abstract = {Der Artikel schildert die Geschichte verschiedener Teile des Manuskriptnachlasses Alexander von Humboldts, die sich heute in der Staatsbibliothek zu Berlin - Preußischer Kulturbesitz (SBB) und in der Biblioteka Jagiellońska in Krakau (BJ) befinden. Dabei wird insbesondere auf den unterschiedlichen ‚Quellenwert' der drei großen Nachlassabteilungen - der amerikanischen Reisetageb{\"u}cher, der Kollektaneen zum Kosmos (beide SBB) und dem sogenannten Nachlass Alexander von Humboldt (BJ) - eingegangen.}, language = {de} } @article{Kraft2015, author = {Kraft, Tobias}, title = {Humboldts Hefte}, series = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, volume = {XVI}, journal = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, number = {31}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1617-5239}, doi = {10.18443/222}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88986}, pages = {49 -- 59}, year = {2015}, abstract = {Der 2013 gegl{\"u}ckte Ankauf der Amerikanischen Tageb{\"u}cher durch ein Konsortium {\"o}ffentlicher und privater Geldgeber hat es nicht nur erm{\"o}glicht, Alexander von Humboldts Reisemanuskripte zum ersten Mal einer breiten interessierten {\"O}ffentlichkeit vorzustellen, sondern wirft auch ein besonderer Licht auf die Geschichte ihrer Rezeption und Erforschung. Welche Phasen der Arbeit und Auswertung der Tageb{\"u}cher lassen sich nachzeichnen? Und an welchem Punkt steht die Humboldt-Forschung in dieser Frage heute?}, language = {de} } @article{BispinckRossbacher2015, author = {Bispinck-Roßbacher, Julia}, title = {„Zwischen den Zeilen …"}, series = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, volume = {XVI}, journal = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, number = {31}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1617-5239}, doi = {10.18443/221}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88978}, pages = {43 -- 48}, year = {2015}, abstract = {Der Artikel besch{\"a}ftigt sich mit dem kodikologischen Befund der Amerikanischen Reisetageb{\"u}cher und materialtechnologischen Untersuchungen zu ihrem Papier und Beschreibstoffen. Der kodikologische Aspekt beinhaltet eine umfassende Erfassung aller physischen Merkmale und Besonderheiten der Tageb{\"u}cher, wobei ein Fokus auf die Zusammenstellung der Lagen, auf heraus getrennten oder ganz fehlenden Seiten liegt. Dies geschieht vor dem Hintergrund, die urspr{\"u}ngliche Zusammenstellung der Tageb{\"u}cher zu rekonstruieren, die Genese zu erforschen und im Nachlass befindliche Teile ggf. fehlenden Bl{\"a}ttern oder Fragmenten in den Tageb{\"u}chern zuzuordnen. Wasserzeichenaufnahmen mit der Thermographiekamera und Tintenanlaysen mithilfe der R{\"o}ntgenfluoreszenztechnik k{\"o}nnen dabei helfen aufzuzeigen, wie die Tageb{\"u}cher entstanden sind und wie sie bis zum Tod Alexander von Humboldts von ihm als Arbeitsinstrument genutzt wurden.}, language = {de} } @article{Bredekamp2015, author = {Bredekamp, Horst}, title = {Die Amerikanischen Reisetageb{\"u}cher}, series = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, volume = {XVI}, journal = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, number = {31}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1617-5239}, doi = {10.18443/220}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88963}, pages = {26 -- 42}, year = {2015}, abstract = {Die Reisetageb{\"u}cher der Amerika-Reise (1799-1804) stellen ein Kompendium an schriftlichen Eintr{\"a}gen, Tabellen, Diagrammen und Zeichnungen dar, das in der Tradition r{\"o}mischer Papiermuseen des 17. Jhs. steht. Sie k{\"o}nnen als Mikrokosmen kleiner Kunstkammern aufgefasst werden, in denen Naturobjekte, Kunstwerke und Arbeitsmittel einen gemeinsamen Reflexionsraum bilden. Im Zentrum des vorliegenden Beitrags steht Humboldts Auffassung einer gestalteten Bestimmung von Landschaft vermittels besonders einpr{\"a}gsamer Bildformen. Auf erstaunliche Weise n{\"a}hert sich Humboldts {\"A}sthetik der Gesamtsicht von Natur Charles Darwins Begriff der nat{\"u}rlichen Sch{\"o}nheit an. In den Reisetageb{\"u}chern zeigt sich ein heterogener, von Lebendigkeit zeugender Charakter, der sowohl durch das unterschiedliche Format der einzelnen Hefte, als auch durch die inkonsistente Behandlung des Papiers erreicht wird. Dieser bewegliche Zug setzt sich in zahlreichen Zetteln, Briefen und weiteren Texten fort als ein eigenes Prinzip von Evolution.}, language = {de} } @article{Ette2015, author = {Ette, Ottmar}, title = {Tras la huella de la vida}, series = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, volume = {XVI}, journal = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, number = {31}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1617-5239}, doi = {10.18443/219}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88913}, pages = {21 -- 25}, year = {2015}, abstract = {El proyecto de larga duraci{\´o}n "Centro Alejandro de Humboldt - Ciencia en movimiento" (iniciado en 2015) de la Academia de las Ciencias y Humanidades Berl{\´i}n-Brandemburgo tiene como objetivo la edici{\´o}n de los manuscritos de viaje del famoso autor, naturalista, cosmop{\´o}lito y viajero. La edici{\´o}n incluir{\´a} los manuscritos de sus dos viajes hemisf{\´e}ricos (Am{\´e}rica, Asia) como tambi{\´e}n los de su legado literario. La pregunta esencial que acompa{\~n}a las investigaciones en torno al proyecto de la Academia es la importancia que Humboldt le da a la vida y a la convivencia. Los tres pilares en los que descansa la reflexi{\´o}n son: la relacionalidad, la concomitancia entre ciencia y est{\´e}tica y el movimiento.}, language = {es} } @article{Schwarz2015, author = {Schwarz, Ingo}, title = {„etwas hervorzubringen, was meines K{\"o}nigs und meines Vaterlandes werth sein kann"}, series = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, volume = {XVI}, journal = {HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies}, number = {31}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1617-5239}, doi = {10.18443/218}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88904}, pages = {5 -- 20}, year = {2015}, language = {de} } @misc{MondalMarquardtJaniaketal.2015, author = {Mondal, Suvendu Sekhar and Marquardt, Dorothea and Janiak, Christoph and Holdt, Hans-J{\"u}rgen}, title = {Use of a 4,5-dicyanoimidazolate anion based ionic liquid for the synthesis of iron and silver nanoparticles}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89696}, pages = {5476 -- 5483}, year = {2015}, abstract = {Sixteen new ionic liquids (ILs) with tetraethylammonium, 1-butyl-3-methylimidazolium, 3-methyl-1-octylimidazolium and tetrabutylphosphonium cations paired with 2-substituted 4,5-dicyanoimidazolate anions (substituent at C2 = methyl, trifluoromethyl, pentafluoroethyl, N,N′-dimethyl amino and nitro) have been synthesized and characterized by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The effects of cation and anion type and structure of the resulting ILs, including several room temperature ionic liquids (RTILs), are reflected in the crystallization, melting points and thermal decomposition of the ILs. ILs exhibited large liquid and crystallization ranges and formed glasses on cooling with glass transition temperatures in the range of -22 to -71 °C. We selected one of the newly designed ILs due to its bigger size, compared to the common conventional IL anion and high electron-withdrawing nitrile group leads to an overall stabilization anion that may stabilize the metal nanoparticles. Stable and better separated iron and silver nanoparticles are obtained by the decomposition of corresponding Fe2(CO)9 and AgPF6, respectively, under N2-atmosphere in newly designed nitrile functionalized 4,5-dicyanoimidazolate anion based IL. Very small and uniform size for Fe-nanoparticles of about 1.8 ± 0.6 nm were achieved without any additional stabilizers or capping molecules. Comparatively bigger size of Ag-nanoparticles was obtained through the reduction of AgPF6 by hydrogen gas. Additionally, the AgPF6 precursor was decomposed under microwave irradiation (MWI), fabricating nut-in-shell-like, that is, core-separated-from-shell Ag-nano-structures.}, language = {en} } @misc{KlaperWessigLinker2015, author = {Klaper, M. and Wessig, Pablo and Linker, Torsten}, title = {Base catalysed decomposition of anthracene endoperoxide}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89676}, pages = {1210 -- 1213}, year = {2015}, abstract = {Catalytic amounts of a weak base are sufficient to induce the decomposition of anthracene endoperoxides to anthraquinone. The mechanism has been elucidated by isolation of intermediates in combination with DFT calculations. The whole process is suitable for the convenient generation of hydrogen peroxide under very mild conditions.}, language = {en} } @misc{PrestelMoeller2015, author = {Prestel, Andreas and M{\"o}ller, Heiko Michael}, title = {Spatio-temporal control of cellular uptake achieved by photoswitchable cell-penetrating peptides}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89658}, pages = {701 -- 704}, year = {2015}, abstract = {The selective uptake of compounds into specific cells of interest is a major objective in cell biology and drug delivery. By incorporation of a novel, thermostable azobenzene moiety we generated peptides that can be switched optically between an inactive state and an active, cell-penetrating state with excellent spatio-temporal control.}, language = {en} } @misc{KlierKumke2015, author = {Klier, Dennis Tobias and Kumke, Michael Uwe}, title = {Analysing the effect of the crystal structure on upconversion luminescence in Yb3+,Er3+-co-doped NaYF4 nanomaterials}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89630}, pages = {11228 -- 11238}, year = {2015}, abstract = {NaYF4:Yb:Er nanoparticles (UCNP) were synthesized under mild experimental conditions to obtain a pure cubic lattice. Upon annealing at different temperatures up to Tan = 700 °C phase transitions to the hexagonal phase and back to the cubic phase were induced. The UCNP materials obtained for different Tan were characterized with respect to the lattice phase using standard XRD and Raman spectroscopy as well as steady state and time resolved upconversion luminescence. The standard techniques showed that for the annealing temperature range 300 °C < Tan < 600 °C the hexagonal lattice phase was dominant. For Tan < 300 °C hardly any change in the lattice phase could be deduced, whereas for Tan > 600 °C a back transfer to the α-phase was observed. Complementarily, the luminescence upconversion properties of the annealed UCNP materials were characterized in steady state and time resolved luminescence measurements. Distinct differences in the upconversion luminescence intensity, the spectral intensity distribution and the luminescence decay kinetics were found for the cubic and hexagonal lattice phases, respectively, corroborating the results of the standard analytical techniques used. In laser power dependent measurements of the upconversion luminescence intensity it was found that the green (G1, G2) and red (R) emission of Er3+ showed different effects of Tan on the number of required photons reflecting the differences in the population routes of different energy levels involved. Furthermore, the intensity ratio of Gfull/R is highly effected by the laser power only when the β-phase is present, whereas the G1/G2 intensity ratio is only slightly effected regardless of the crystal phase. Moreover, based on different upconversion luminescence kinetics characteristics of the cubic and hexagonal phase time-resolved area normalized emission spectra (TRANES) proved to be a very sensitive tool to monitor the phase transition between cubic and hexagonal phases. Based on the TRANES analysis it was possible to resolve the lattice phase transition in more detail for 200 °C < Tan < 300 °C, which was not possible with the standard techniques.}, language = {en} } @misc{KlierKumke2015, author = {Klier, Dennis Tobias and Kumke, Michael Uwe}, title = {Upconversion NaYF4:Yb:Er nanoparticles co-doped with Gd3+ and Nd3+ for thermometry on the nanoscale}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89618}, pages = {67149 -- 67156}, year = {2015}, abstract = {In the present work, the upconversion luminescence properties of oleic acid capped NaYF4:Gd3+:Yb3+:Er3+ upconversion nanoparticles (UCNP) with pure β crystal phase and Nd3+ ions as an additional sensitizer were studied in the temperature range of 288 K < T < 328 K. The results of this study showed that the complex interplay of different mechanisms and effects, causing the special temperature behavior of the UCNP can be developed into thermometry on the nanoscale, e.g. to be applied in biological systems on a cellular level. The performance was improved by the use of Nd3+ as an additional dopant utilizing the cascade sensitization mechanism in tri-doped UCNP.}, language = {en} } @misc{MatisSchoenbornSaalfrank2015, author = {Matis, Jochen Ren{\´e} and Sch{\"o}nborn, Jan Boyke and Saalfrank, Peter}, title = {A multi-reference study of the byproduct formation for a ring-closed dithienylethene photoswitch}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89594}, pages = {14088 -- 14095}, year = {2015}, abstract = {Photodriven molecular switches are sometimes hindered in their performance by forming byproducts which act as dead ends in sequences of switching cycles, leading to rapid fatigue effects. Understanding the reaction pathways to unwanted byproducts is a prerequisite for preventing them. This article presents a study of the photochemical reaction pathways for byproduct formation in the photochromic switch 1,2-bis-(3-thienyl)-ethene. Specifically, using single- and multi-reference methods the post-deexcitation reaction towards the byproduct in the electronic ground state S0 when starting from the S1-S0 conical intersection (CoIn), is considered in detail. We find an unusual low-energy pathway, which offers the possibility for the formation of a dyotropic byproduct. Several high-energy pathways can be excluded with high probability.}, language = {en} } @misc{Reger2015, type = {Master Thesis}, author = {Reger, Martin}, title = {M{\"a}nnlichkeits- und Weiblichkeitskonstruktionen deutschsprachiger Rapper/-innen}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-342-8}, issn = {2363-8168}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-81630}, school = {Universit{\"a}t Potsdam}, pages = {143 S.}, year = {2015}, abstract = {Gangsta-Rap ist besonders in Deutschland stark m{\"a}nnlich dominiert und als Musikgenre kommerziell sehr erfolgreich. Er gilt als eine der wenigen Zonen bislang weitestgehend unbedrohter M{\"a}nnlichkeitsentw{\"u}rfe. Die Ende des Jahres 2011 in Erscheinung getretene Gangsta-Rapperin ­Schwesta Ewa k{\"o}nnte gerade aufgrund ihres biologischen Geschlechts die Chance nutzen, M{\"a}nnlichkeitskonzeptionen und Vorstellungen von Weiblichkeit im Gangsta-­Rap infrage zu stellen. Doch welche Konstruktionen von M{\"a}nnlichkeit und Weiblichkeit stellen M{\"a}nner und Frauen in der Praxis genau auf? Zur Beantwortung dieser Forschungsfrage werden prim{\"a}r die soziologischen Konzepte zu hegemonialer M{\"a}nnlichkeit (Connell), Habitus (Bourdieu) und m{\"a}nnlichem Geschlechts­habitus (Meuser) herangezogen. Die theoriegeleitete, fallspezifische Zuordnung und Analyse von Songtexten erfolgt durch die empirische Methode der inhaltlich strukturierenden Inhaltsanalyse. Ein Ergebnis ist, dass Schwesta Ewa eine komplexe Eigen-Weiblichkeitskonstruktion aufstellt. {\"U}ber den Vergleich mit dem untersuchten Gangsta-Rapper Kollegah wird u. a. die These von Connell und Messerschmidt empirisch nachgewiesen, wonach auch Frauen Tr{\"a}ger von Aspekten hegemonialer M{\"a}nnlichkeit sein k{\"o}nnen. Die erste Forschungsfrage untersucht vor allem die homosoziale Dimension sowie das f{\"u}r Gangsta-Rap konstitutive Moment von Eigenaufwertung und Fremdabwertung. Welche Muster von Anerkennung existieren jedoch zwischen M{\"a}nnern und Frauen? F{\"u}r diese zweite Forschungsfrage wird eine Diskursanalyse durchgef{\"u}hrt, mit der viele K{\"u}nstler/-innen und ihre Songtexte untersucht werden. Es wird ermittelt, dass Gangsta-Rap auch als Repr{\"a}sentation konservativer Geschlechterbilder zu verstehen ist. Ebenso sind Schilderungen zu allt{\"a}glich erfahrbaren sozialen Ph{\"a}nomenen wie Liebe und Freundschaft als auch zu den damit einhergehenden sozialen Rollen vorzufinden. Die Perspektive gegengeschlechtlicher Wertsch{\"a}tzung kann aber gleichzeitig ablaufende Abwertung beibehalten.}, language = {de} } @misc{deCarvalhoMetzlerCherstvy2015, author = {de Carvalho, Sidney J. and Metzler, Ralf and Cherstvy, Andrey G.}, title = {Inverted critical adsorption of polyelectrolytes in confinement}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89562}, pages = {4430 -- 4443}, year = {2015}, abstract = {What are the fundamental laws for the adsorption of charged polymers onto oppositely charged surfaces, for convex, planar, and concave geometries? This question is at the heart of surface coating applications, various complex formation phenomena, as well as in the context of cellular and viral biophysics. It has been a long-standing challenge in theoretical polymer physics; for realistic systems the quantitative understanding is however often achievable only by computer simulations. In this study, we present the findings of such extensive Monte-Carlo in silico experiments for polymer-surface adsorption in confined domains. We study the inverted critical adsorption of finite-length polyelectrolytes in three fundamental geometries: planar slit, cylindrical pore, and spherical cavity. The scaling relations extracted from simulations for the critical surface charge density sc—defining the adsorption-desorption transition—are in excellent agreement with our analytical calculations based on the ground-state analysis of the Edwards equation. In particular, we confirm the magnitude and scaling of sc for the concave interfaces versus the Debye screening length 1/k and the extent of confinement a for these three interfaces for small ka values. For large ka the critical adsorption condition approaches the known planar limit. The transition between the two regimes takes place when the radius of surface curvature or half of the slit thickness a is of the order of 1/k. We also rationalize how sc(k) dependence gets modified for semi-flexible versus flexible chains under external confinement. We examine the implications of the chain length for critical adsorption—the effect often hard to tackle theoretically—putting an emphasis on polymers inside attractive spherical cavities. The applications of our findings to some biological systems are discussed, for instance the adsorption of nucleic acids onto the inner surfaces of cylindrical and spherical viral capsids.}, language = {en} } @misc{HentrichJungingerBrunsetal.2015, author = {Hentrich, Doreen and Junginger, Mathias and Bruns, Michael and B{\"o}rner, Hans Gerhard and Brandt, Jessica and Brezesinski, Gerald and Taubert, Andreas}, title = {Interface-controlled calcium phosphate mineralization}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89540}, pages = {6901 -- 6913}, year = {2015}, abstract = {The phase behavior of an amphiphilic block copolymer based on a poly(aspartic acid) hydrophilic block and a poly(n-butyl acrylate) hydrophobic block was investigated at the air-water and air-buffer interface. The polymer forms stable monomolecular films on both subphases. At low pH, the isotherms exhibit a plateau. Compression-expansion experiments and infrared reflection absorption spectroscopy suggest that the plateau is likely due to the formation of polymer bi- or multilayers. At high pH the films remain intact upon compression and no multilayer formation is observed. Furthermore, the mineralization of calcium phosphate beneath the monolayer was studied at different pH. The pH of the subphase and thus the polymer charge strongly affects the phase behavior of the film and the mineral formation. After 4 h of mineralization at low pH, atomic force microscopy shows smooth mineral films with a low roughness. With increasing pH the mineral films become inhomogeneous and the roughness increases. Transmission electron microscopy confirms this: at low pH a few small but uniform particles form whereas particles grown at higher pH are larger and highly agglomerated. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy confirm the formation of calcium phosphate. The levels of mineralization are higher in samples grown at high pH.}, language = {en} } @phdthesis{Buss2015, author = {Buß, Claudia}, title = {Instrumente der B{\"u}rgerbeteiligung in St{\"a}dten}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88888}, school = {Universit{\"a}t Potsdam}, pages = {xi, 468}, year = {2015}, abstract = {Die vergleichende Arbeit besch{\"a}ftigt sich mit der B{\"u}rgerbeteiligung in St{\"a}dten in Deutschland und Frankreich. In den letzten 20 Jahren haben sich die Formen lokaler Demokratie immer wieder ver{\"a}ndert und sich den {\"o}rtlichen Gegebenheiten angepasst. Das Interesse der B{\"u}rger, Verwaltung und politisch gew{\"a}hlten Vertreter an Partizipation w{\"a}chst stetig . Das heißt aber auch, dass sich diese 3 Akteure den neuen Strukturen anpassen und eigene Strategien entwickeln m{\"u}ssen. Die demokratischen Formen der kooperativen bzw. partizipativen Demokratie werden immer h{\"a}ufiger angewandt. Diese Arbeit evaluiert die verschiedenen B{\"u}rgerbeteiligungsinstrumente in Frankreich und Deutschland in dem zwischen Input, Output und Outcome unterschieden wird. Insbesondere die B{\"u}rgerhaushalte, Beir{\"a}te und Quartiersr{\"a}te werden genauer betrachtet. Die Ergebnisse zeigen erste Hinweise in welche demokratische Richtung sich die deutschen St{\"a}dte k{\"u}nftig entwickeln.}, language = {de} } @phdthesis{Schernthanner2015, author = {Schernthanner, Harald}, title = {Untersuchungen zur r{\"a}umlichen Analyse und Visualisierung von Mietpreisdaten f{\"u}r Immobilienportale}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89492}, school = {Universit{\"a}t Potsdam}, pages = {xiii, 136}, year = {2015}, abstract = {Die vorliegende Arbeit verfolgt das Ziel, aus geoinformatischer Sicht eine konzeptionelle Grundlage zur r{\"a}umlichen Optimierung von Immobilienportalen zu schaffen. Die Arbeit geht dabei von zwei Hypothesen aus: 1. Verfahren der r{\"a}umlichen Statistik und des Maschinellen Lernens zur Mietpreissch{\"a}tzung sind den bisher eingesetzten Verfahren der hedonischen Regression {\"u}berlegen und eignen sich zur r{\"a}umlichen Optimierung von Immobilienportalen. 2. Die von Immobilienportalen publizierten webbasierten Mietpreiskarten geben nicht die tats{\"a}chlichen r{\"a}umlichen Verh{\"a}ltnisse auf Immobilienm{\"a}rkten wieder. Alternative webbasierte Darstellungsformen, wie z.B. Gridmaps, sind dem Status Quo der Immobilienpreiskarten von Immobilienportalen {\"u}berlegen und visualisieren die tats{\"a}chlichen r{\"a}umlichen Verh{\"a}ltnisse von Immobilienpreisen zweckm{\"a}ßiger. Beide Thesen k{\"o}nnen bewiesen werden. Es erfolgt zun{\"a}chst eine umfangreiche Erhebung des Forschungsbedarfs mittels Literaturstudien und technologischer Recherche. Zur Beantwortung der Forschungsfragen wird als quantitative Datenbasis ein 74.098 Mietangebote umfassender Datensatz (von Januar 2007 bis September 2013) eines Immobilienportals akquiriert. Dieser reicht jedoch nicht in vollem Umfang zur Beantwortung der Fragestellungen aus. Deshalb f{\"u}hrt der Autor Experteninterviews zur Erhebung einer qualitativen Datenbasis. Deren Analyse ergibt in Kombination mit der Literaturstudie und der technologischen Recherche ein umfassendes, bisher so nicht verf{\"u}gbares Bild. Es stellt den Status Quo der r{\"a}umlichen Sicht sowie der raumanalytischen und geovisuellen Defizite von Immobilienportalen dar. Zur Optimierung der raumanalytischen und geovisuellen Defizite werden forschungsbasierte L{\"o}sungsans{\"a}tze herausgearbeitet und teilimplementiert. Methoden des Maschinellen Lernens und r{\"a}umliche Sch{\"a}tzverfahren werden als Alternativen zu den von Immobilienportalen bisher genutzten „nicht r{\"a}umlichen" Analyseverfahren zur Preismodellierung untersucht. Auf Grundlage eines hierf{\"u}r konzipierten Validierungsrahmens werden diese Methoden f{\"u}r die Nutzung im Kontext von Immobilienportalen adaptiert. Die prototypische Teilimplementierung zeigt die programmiertechnische Umsetzung des Konzeptes auf. Eine umfassende Analyse geeigneter Sekund{\"a}rvariablensets zur Mietpreissch{\"a}tzung liefert als methodisches Resultat, dass Interpolatoren, die Sekund{\"a}rvariablen ben{\"o}tigen (Kriging with external drift, Ordinary Cokriging), kaum zu valideren Mietpreissch{\"a}tzergebnissen gelangen als die Methode des Ordinary Kriging, die keine Sekund{\"a}rvariablen ben{\"o}tigt. Die Methoden Random Forest aus dem Maschinellen Lernen und die Geographisch Gewichtete Regression hingegen bergen großes Potential zur Nutzung der r{\"a}umlichen Mietpreissch{\"a}tzung im Kontext von Immobilien-portalen. Die Forschungsergebnisse der r{\"a}umlichen Preismodellierung werden in die r{\"a}umliche Visualisierung von Mietpreisen transferiert. F{\"u}r die webbasierte Mietpreisdarstellung wird ein Set alternativer Darstellungsmethoden entwickelt, um Mietpreiskarten-Prototypen abzuleiten. Ein methodisches Ergebnis der Entwicklung der Mietpreiskarten-Prototypen ist die Entwicklung eines geeigneten Ansatzes der Losl{\"o}sung des Preisbezugs von fachfremd verwendeten Bezugsgeometrien. Hierf{\"u}r wird vom Autor der Begriff der zonenlosen Preiskarte gepr{\"a}gt. Diese werden mit Methoden des Gridmapping erstellt. Es werden optimale Rasteraufl{\"o}sungen zur Darstellung interpolierter Rastergr{\"o}ßen ermittelt. Zonenlose Preiskarten mit Methoden des Gridmapping, gepaart mit einer optionalen geb{\"a}udescharfen Darstellung in gr{\"o}ßeren Maßst{\"a}ben, sind als Resultate der Forschung die bestm{\"o}gliche, sich an realen Verh{\"a}ltnissen orientierende, r{\"a}umliche Mietpreisdarstellung. Die entstandenen Prototypen sind eine Ann{\"a}herung der wahren Verteilung des Mietpreises im Raum und um einiges sch{\"a}rfer, als die auf der hedonischen Regression basierenden Darstellungen. Somit kann die wahre „Topographie" der Mietpreislandschaft abgebildet werden. Ein Einsatz der Karten f{\"u}r Nutzergruppen wie Makler, Investoren oder Kommunen zur Analyse st{\"a}dtischer Mietm{\"a}rkte ist denkbar. Alle entstandenen Prototypen sind unter der Nutzung von Map APIs umgesetzt. Ein Ergebnis dessen ist, dass Map APIs noch an diversen „Kinderkrankheiten" leiden und derart umgesetzte Mietpreiskarten noch einen weiten Weg vor sich haben, bis sie das Niveau thematischer Karten von Immhof oder Arnberger erreichen. Die konzeptionellen {\"U}berlegungen und Teilimplementierungen m{\"u}nden in drei Prozessketten, die Umsetzungsoptionen f{\"u}r eine r{\"a}umliche Optimierung von Immobilienportalen darstellen. Dabei werden zwei Szenarien f{\"u}r eine r{\"a}umlich optimierte Mietpreissch{\"a}tzung und ein Szenario f{\"u}r eine r{\"a}umlich optimierte Mietpreisdarstellung herausgearbeitet.}, language = {de} } @phdthesis{Boesche2015, author = {B{\"o}sche, Nina Kristine}, title = {Detection of rare earth elements and rare earth oxides with hyperspectral spectroscopy}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-85363}, school = {Universit{\"a}t Potsdam}, pages = {147}, year = {2015}, abstract = {The continuously increasing demand for rare earth elements in technical components of modern technologies, brings the detection of new deposits closer into the focus of global exploration. One promising method to globally map important deposits might be remote sensing, since it has been used for a wide range of mineral mapping in the past. This doctoral thesis investigates the capacity of hyperspectral remote sensing for the detection of rare earth element deposits. The definition and the realization of a fundamental database on the spectral characteristics of rare earth oxides, rare earth metals and rare earth element bearing materials formed the basis of this thesis. To investigate these characteristics in the field, hyperspectral images of four outcrops in Fen Complex, Norway, were collected in the near-field. A new methodology (named REEMAP) was developed to delineate rare earth element enriched zones. The main steps of REEMAP are: 1) multitemporal weighted averaging of multiple images covering the sample area; 2) sharpening the rare earth related signals using a Gaussian high pass deconvolution technique that is calibrated on the standard deviation of a Gaussian-bell shaped curve that represents by the full width of half maxima of the target absorption band; 3) mathematical modeling of the target absorption band and highlighting of rare earth elements. REEMAP was further adapted to different hyperspectral sensors (EO-1 Hyperion and EnMAP) and a new test site (Lofdal, Namibia). Additionally, the hyperspectral signatures of associated minerals were investigated to serve as proxy for the host rocks. Finally, the capacity and limitations of spectroscopic rare earth element detection approaches in general and of the REEMAP approach specifically were investigated and discussed. One result of this doctoral thesis is that eight rare earth oxides show robust absorption bands and, therefore, can be used for hyperspectral detection methods. Additionally, the spectral signatures of iron oxides, iron-bearing sulfates, calcite and kaolinite can be used to detect metasomatic alteration zones and highlight the ore zone. One of the key results of this doctoral work is the developed REEMAP approach, which can be applied from near-field to space. The REEMAP approach enables rare earth element mapping especially for noisy images. Limiting factors are a low signal to noise ratio, a reduced spectral resolution, overlaying materials, atmospheric absorption residuals and non-optimal illumination conditions. Another key result of this doctoral thesis is the finding that the future hyperspectral EnMAP satellite (with its currently published specifications, June 2015) will be theoretically capable to detect absorption bands of erbium, dysprosium, holmium, neodymium and europium, thulium and samarium. This thesis presents a new methodology REEMAP that enables a spatially wide and rapid hyperspectral detection of rare earth elements in order to meet the demand for fast, extensive and efficient rare earth exploration (from near-field to space).}, language = {en} } @phdthesis{Priegnitz2015, author = {Priegnitz, Mike}, title = {Development of geophysical methods to characterize methane hydrate reservoirs on a laboratory scale}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89321}, school = {Universit{\"a}t Potsdam}, pages = {X, 99}, year = {2015}, abstract = {Gashydrate sind kristalline Feststoffe bestehend aus Wasser und Gasmolek{\"u}len. Sie sind stabil bei erh{\"o}hten Dr{\"u}cken und niedrigen Temperaturen. Nat{\"u}rliche Hydratvorkommen treten daher an Kontinentalh{\"a}ngen, in Permafrostb{\"o}den und in tiefen Seen sowie Binnenmeeren auf. Bei der Hydratbildung orientieren sich die Wassermolek{\"u}le neu und bilden sogenannte K{\"a}figstrukturen, in die Gas eingelagert werden kann. Aufgrund des hohen Drucks bei der Hydratbildung k{\"o}nnen große Mengen an Gas in die Hydratstruktur eingebaut werden. Das Volumenverh{\"a}ltnis von Wasser zu Gas kann dabei bis zu 1:172 bei 0°C und Atmosph{\"a}rendruck betragen. Nat{\"u}rliche Gashydrate enthalten haupts{\"a}chlich Methan. Da Methan sowohl ein Treibhausgas als auch ein Brenngas ist, stellen Gashydrate gleichermaßen eine potentielle Energieressource sowie eine m{\"o}gliche Quelle f{\"u}r Treibhausgase dar. Diese Arbeit untersucht die physikalischen Eigenschaften von Methanhydrat ges{\"a}ttigten Sedimentproben im Labormaßstab. Dazu wurde ein großer Reservoirsimulator (LARS) mit einer eigens entwickelten elektrischen Widerstandstomographie ausger{\"u}stet, die das erste Mal an hydratges{\"a}ttigten Sedimentproben unter kontrollierten Temperatur-, Druck-, und Hydrats{\"a}ttigungsbedingungen im Labormaßstab angewendet wurde. {\"U}blicherweise ist der Porenraum von (marinen) Sedimenten mit elektrisch gut leitendem Salzwasser gef{\"u}llt. Da Hydrate einen elektrischen Isolator darstellen, ergeben sich große Kontraste hinsichtlich der elektrischen Eigenschaften im Porenraum w{\"a}hrend der Hydratbildung und -zersetzung. Durch wiederholte Messungen w{\"a}hrend der Hydraterzeugung ist es m{\"o}glich die r{\"a}umliche Widerstandsverteilung in LARS aufzuzeichnen. Diese Daten bilden in der Folge die Grundlage f{\"u}r eine neue Auswerteroutine, welche die r{\"a}umliche Widerstandsverteilung in die r{\"a}umliche Verteilung der Hydrats{\"a}ttigung {\"u}berf{\"u}hrt. Dadurch ist es m{\"o}glich, die sich {\"a}ndernde Hydrats{\"a}ttigung sowohl r{\"a}umlich als auch zeitlich hoch aufgel{\"o}st w{\"a}hrend der gesamten Hydraterzeugungsphase zu verfolgen. Diese Arbeit zeigt, dass die entwickelte Widerstandstomographie eine gute Datenqualit{\"a}t aufwies und selbst geringe Hydrats{\"a}ttigungen innerhalb der Sedimentprobe detektiert werden konnten. Bei der Umrechnung der Widerstandsverteilung in lokale Hydrat-S{\"a}ttigungswerte wurden die besten Ergebnisse mit dem Archie-var-phi Ansatz erzielt, der die zunehmende Hydratphase dem Sedimentger{\"u}st zuschreibt, was einer Abnahme der Porosit{\"a}t gleichkommt. Die Widerstandsmessungen zeigten weiterhin, dass die schnelle Hydraterzeugung im Labor zur Ausbildung von kleinen Hydratkristallen f{\"u}hrte, die dazu neigten, zu rekristalliesieren. Es wurden weiterhin Hydrat-Abbauversuche durchgef{\"u}hrt, bei denen die Hydratphase {\"u}ber Druckerniedrigung in Anlehnung an den 2007/2008 Mallik Feldtest zersetzt wurde. Dabei konnte beobachtet werden, dass die Muster der Gas- undWasserflussraten im Labor zum Teil gut nachgebildet werden konnten, jedoch auch aufbaubedingte Abweichungen auftraten. In zwei weiteren Langzeitversuchen wurde die Realisierbarkeit und das Verhalten bei CO2-CH4-Hydrat Austauschversuchen in LARS untersucht. Das tomographische Messsystem wurde dabei genutzt um w{\"a}hrend der CH4 Hydrat Aufbauphase die Hydratverteilung innerhalb der Sedimentprobe zu {\"u}berwachen. Im Zuge der anschließenden CO2-Injektion konnte mithilfe der Widerstandstomographie die sich ausbreitende CO2-Front {\"u}berwacht und der Zeitpunkt des CO2 Durchbruchs identifiziert werden.}, language = {en} } @book{OPUS4-8334, title = {Proceedings of the 9th Ph.D. retreat of the HPI Research School on service-oriented systems engineering}, number = {100}, editor = {Meinel, Christoph and Plattner, Hasso and D{\"o}llner, J{\"u}rgen Roland Friedrich and Weske, Mathias and Polze, Andreas and Hirschfeld, Robert and Naumann, Felix and Giese, Holger and Baudisch, Patrick and Friedrich, Tobias}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-345-9}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-83347}, publisher = {Universit{\"a}t Potsdam}, pages = {vi, 250}, year = {2015}, abstract = {Design and implementation of service-oriented architectures impose numerous research questions from the fields of software engineering, system analysis and modeling, adaptability, and application integration. Service-oriented Systems Engineering represents a symbiosis of best practices in object orientation, component-based development, distributed computing, and business process management. It provides integration of business and IT concerns. Service-oriented Systems Engineering denotes a current research topic in the field of IT-Systems Engineering with high potential in academic research and industrial application. The annual Ph.D. Retreat of the Research School provides all members the opportunity to present the current state of their research and to give an outline of prospective Ph.D. projects. Due to the interdisciplinary structure of the Research School, this technical report covers a wide range of research topics. These include but are not limited to: Human Computer Interaction and Computer Vision as Service; Service-oriented Geovisualization Systems; Algorithm Engineering for Service-oriented Systems; Modeling and Verification of Self-adaptive Service-oriented Systems; Tools and Methods for Software Engineering in Service-oriented Systems; Security Engineering of Service-based IT Systems; Service-oriented Information Systems; Evolutionary Transition of Enterprise Applications to Service Orientation; Operating System Abstractions for Service-oriented Computing; and Services Specification, Composition, and Enactment.}, language = {en} } @phdthesis{Hanf2015, author = {Hanf, Franziska Stefanie}, title = {South Asian summer monsoon variability: a modelling study with the atmospheric regional climate model HIRHAM5}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89331}, school = {Universit{\"a}t Potsdam}, pages = {ii, 126}, year = {2015}, abstract = {The lives of more than 1/6 th of the world population is directly affected by the caprices of the South Asian summer monsoon rainfall. India receives around 78 \% of the annual precipitation during the June-September months, the summer monsoon season of South Asia. But, the monsoon circulation is not consistent throughout the entire summer season. Episodes of heavy rainfall (active periods) and low rainfall (break periods) are inherent to the intraseasonal variability of the South Asian summer monsoon. Extended breaks or long-lasting dryness can result in droughts and hence trigger crop failures and in turn famines. Furthermore, India's electricity generation from renewable sources (wind and hydro-power), which is increasingly important in order to satisfy the rapidly rising demand for energy, is highly reliant on the prevailing meteorology. The major drought years 2002 and 2009 for the Indian summer monsoon during the last decades, which are results of the occurrence of multiple extended breaks, emphasise exemplary that the understanding of the monsoon system and its intraseasonal variation is of greatest importance. Although, numerous studies based on observations, reanalysis data and global model simulations have been carried out with the focus on monsoon active and break phases over India, the understanding of the monsoon intraseasonal variability is only in the infancy stage. Regional climate models could benefit the comprehension of monsoon breaks by its resolution advantage. This study investigates moist dynamical processes that initiate and maintain breaks during the South Asian summer monsoon using the atmospheric regional climate model HIRHAM5 at a horizontal resolution of 25 km forced by the ECMWF ERA Interim reanalysis for the period 1979-2012. By calculating moisture and moist static energy budgets the various competing mechanisms leading to extended breaks are quantitatively estimated. Advection of dry air from the deserts of western Asia towards central India is the dominant moist dynamical process in initiating extended break conditions over South Asia. Once initiated, the extended breaks are maintained due to many competing mechanisms: (i) the anomalous easterlies at the southern flank of this anticyclonic anomaly weaken the low-level cross-equatorial jet and thus the moisture transport into the monsoon region, (ii) differential radiative heating over the continental and the oceanic tropical convergence zone induces a local Hadley circulation with anomalous rising over the equatorial Indian Ocean and descent over central India, and (iii) a cyclonic response to positive rainfall anomalies over the near-equatorial Indian Ocean amplifies the anomalous easterlies over India and hence contributes to the low-level divergence over central India. A sensitivity experiment that mimics a scenario of higher atmospheric aerosol concentrations over South Asia addresses a current issue of large uncertainty: the role aerosols play in suppressing monsoon rainfall and hence in triggering breaks. To study the indirect aerosol effects the cloud droplet number concentration was increased to imitate the aerosol's function as cloud condensation nuclei. The sensitivity experiment with altered microphysical cloud properties shows a reduction in the summer monsoon precipitation together with a weakening of the South Asian summer monsoon. Several physical mechanisms are proposed to be responsible for the suppressed monsoon rainfall: (i) according to the first indirect radiative forcing the increase in the number of cloud droplets causes an increase in the cloud reflectivity of solar radiation, leading to a climate cooling over India which in turn reduces the hydrological cycle, (ii) a stabilisation of the troposphere induced by a differential cooling between the surface and the upper troposphere over central India inhibits the growth of deep convective rain clouds, (iii) an increase of the amount of low and mid-level clouds together with a decrease in high-level cloud amount amplify the surface cooling and hence the atmospheric stability, and (iv) dynamical changes of the monsoon manifested as a anomalous anticyclonic circulation over India reduce the moisture transport into the monsoon region. The study suggests that the changes in the total precipitation, which are dominated by changes in the convective precipitation, mainly result from the indirect radiative forcing. Suppression of rainfall due to the direct microphysical effect is found to be negligible over India. Break statistics of the polluted cloud scenario indicate an increase in the occurrence of short breaks (3 days), while the frequency of extended breaks (> 7 days) is clearly not affected. This disproves the hypothesis that more and smaller cloud droplets, caused by a high load of atmospheric aerosols trigger long drought conditions over central India.}, language = {en} } @phdthesis{Nimz2015, author = {Nimz, Katharina}, title = {Sound perception and production in a foreign language}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-361-9}, issn = {2190-4545}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88794}, school = {Universit{\"a}t Potsdam}, pages = {xix, 236}, year = {2015}, abstract = {The present study addresses the question of how German vowels are perceived and produced by Polish learners of German as a Foreign Language. It comprises three main experiments: a discrimination experiment, a production experiment, and an identification experiment. With the exception of the discrimination task, the experiments further investigated the influence of orthographic marking on the perception and production of German vowel length. It was assumed that explicit markings such as the Dehnungs-h ("lengthening h") could help Polish GFL learners in perceiving and producing German words more correctly. The discrimination experiment with manipulated nonce words showed that Polish GFL learners detect pure length differences in German vowels less accurately than German native speakers, while this was not the case for pure quality differences. The results of the identification experiment contrast with the results of the discrimination task in that Polish GFL learners were better at judging incorrect vowel length than incorrect vowel quality in manipulated real words. However, orthographic marking did not turn out to be the driving factor and it is suggested that metalinguistic awareness can explain the asymmetry between the two perception experiments. The production experiment supported the results of the identification task in that lengthening h did not help Polish learners in producing German vowel length more correctly. Yet, as far as vowel quality productions are concerned, it is argued that orthography does influence L2 sound productions because Polish learners seem to be negatively influenced by their native grapheme-to-phoneme correspondences. It is concluded that it is important to differentiate between the influence of the L1 and L2 orthographic system. On the one hand, the investigation of the influence of orthographic vowel length markers in German suggests that Polish GFL learners do not make use of length information provided by the L2 orthographic system. On the other hand, the vowel quality data suggest that the L1 orthographic system plays a crucial role in the acquisition of a foreign language. It is therefore proposed that orthography influences the acquisition of foreign sounds, but not in the way it was originally assumed.}, language = {en} } @phdthesis{Lischke2015, author = {Lischke, Betty}, title = {Food web regulation under different forcing regimes in shallow lakes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89149}, school = {Universit{\"a}t Potsdam}, pages = {131}, year = {2015}, abstract = {The standing stock and production of organismal biomass depends strongly on the organisms' biotic environment, which arises from trophic and non-trophic interactions among them. The trophic interactions between the different groups of organisms form the food web of an ecosystem, with the autotrophic and bacterial production at the basis and potentially several levels of consumers on top of the producers. Feeding interactions can regulate communities either by severe grazing pressure or by shortage of resources or prey production, termed top-down and bottom-up control, respectively. The limitations of all communities conglomerate in the food web regulation, which is subject to abiotic and biotic forcing regimes arising from external and internal constraints. This dissertation presents the effects of alterations in two abiotic, external forcing regimes, terrestrial matter input and long-lasting low temperatures in winter. Diverse methodological approaches, a complex ecosystem model study and the analysis of two whole-lake measurements, were performed to investigate effects for the food web regulation and the resulting consequences at the species, community and ecosystem scale. Thus, all types of organisms, autotrophs and heterotrophs, at all trophic levels were investigated to gain a comprehensive overview of the effects of the two mentioned altered forcing regimes. In addition, an extensive evaluation of the trophic interactions and resulting carbon fluxes along the pelagic and benthic food web was performed to display the efficiencies of the trophic energy transfer within the food webs. All studies were conducted in shallow lakes, which is worldwide the most abundant type of lakes. The specific morphology of shallow lakes allows that the benthic production contributes substantially to the whole-lake production. Further, as shallow lakes are often small they are especially sensitive to both, changes in the input of terrestrial organic matter and the atmospheric temperature. Another characteristic of shallow lakes is their appearance in alternative stable states. They are either in a clear-water or turbid state, where macrophytes and phytoplankton dominate, respectively. Both states can stabilize themselves through various mechanisms. These two alternative states and stabilizing mechanisms are integrated in the complex ecosystem model PCLake, which was used to investigate the effects of the enhanced terrestrial particulate organic matter (t-POM) input to lakes. The food web regulation was altered by three distinct pathways: (1) Zoobenthos received more food, increased in biomass which favored benthivorous fish and those reduced the available light due to bioturbation. (2) Zooplankton substituted autochthonous organic matter in their diet by suspended t-POM, thus the autochthonous organic matter remaining in the water reduced its transparency. (3) T-POM suspended into the water and reduced directly the available light. As macrophytes are more light-sensitive than phytoplankton they suffered the most from the lower transparency. Consequently, the resilience of the clear-water state was reduced by enhanced t-POM inputs, which makes the turbid state more likely at a given nutrient concentration. In two subsequent winters long-lasting low temperatures and a concurrent long duration of ice coverage was observed which resulted in low overall adult fish biomasses in the two study lakes - Schulzensee and Gollinsee, characterized by having and not having submerged macrophytes, respectively. Before the partial winterkill of fish Schulzensee allowed for a higher proportion of piscivorous fish than Gollinsee. However, the partial winterkill of fish aligned both communities as piscivorous fish are more sensitive to low oxygen concentrations. Young of the year fish benefitted extremely from the absence of adult fish due to lower predation pressure. Therefore, they could exert a strong top-down control on crustaceans, which restructured the entire zooplankton community leading to low crustacean biomasses and a community composition characterized by copepodites and nauplii. As a result, ciliates were released from top-down control, increased to high biomasses compared to lakes of various trophic states and depths and dominated the zooplankton community. While being very abundant in the study lakes and having the highest weight specific grazing rates among the zooplankton, ciliates exerted potentially a strong top-down control on small phytoplankton and particle-attached bacteria. This resulted in a higher proportion of large phytoplankton compared to other lakes. Additionally, the phytoplankton community was evenly distributed presumably due to the numerous fast growing and highly specific ciliate grazers. Although, the pelagic food web was completely restructured after the subsequent partial winterkills of fish, both lakes were resistant to effects of this forcing regime at the ecosystem scale. The consistently high predation pressure on phytoplankton prevented that Schulzensee switched from the clear-water to the turbid state. Further mechanisms, which potentially stabilized the clear-water state, were allelopathic effects by macrophytes and nutrient limitation in summer. The pelagic autotrophic and bacterial production was an order of magnitude more efficient transferred to animal consumers than the respective benthic production, despite the alterations of the food web structure after the partial winterkill of fish. Thus, the compiled mass-balanced whole-lake food webs suggested that the benthic bacterial and autotrophic production, which exceeded those of the pelagic habitat, was not used by animal consumers. This holds even true if the food quality, additional consumers such as ciliates, benthic protozoa and meiobenthos, the pelagic-benthic link and the potential oxygen limitation of macrobenthos were considered. Therefore, low benthic efficiencies suggest that lakes are primarily pelagic systems at least at the animal consumer level. Overall, this dissertation gives insights into the regulation of organism groups in the pelagic and benthic habitat at each trophic level under two different forcing regimes and displays the efficiency of the carbon transfer in both habitats. The results underline that the alterations of external forcing regimes affect all hierarchical level including the ecosystem.}, language = {en} } @phdthesis{Borschewski2015, author = {Borschewski, Aljona}, title = {Bedeutung der Interaktion von Calcineurin und SORLA f{\"u}r die Regulation des Na⁺,K⁺,2Cl⁻-Kotransporters (NKCC2) in der Niere}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89205}, school = {Universit{\"a}t Potsdam}, pages = {II, 86}, year = {2015}, abstract = {Der Na⁺-K⁺-2Cl⁻-Kotransporter (NKCC2) wird im distalen Nephron der Niere exprimiert. Seine Verteilung umfasst die Epithelien der medull{\"a}ren und kortikalen Teile der dicken aufsteigenden Henle-Schleife (Thick ascending limb, TAL) und die Macula densa. Resorptiver NaCl-Transport {\"u}ber den NKCC2 dient dem renalen Konzentrierungsmechanismus und reguliert systemisch auch Volumenstatus und Blutdruck. Die Aktivit{\"a}t des NKCC2 ist mit der Phosphorylierung seiner N-terminalen Aminos{\"a}urereste Serin 126 und Threonin 96/101 verbunden. Vermittelt wird diese durch die homologen Kinasen SPAK (SPS-related proline/alanine-rich kinase) und OSR1 (Oxidative stress responsive kinase 1), die hierzu ihrerseits phosphoryliert werden m{\"u}ssen. Der regulatorische Kontext dieser Kinasen ist mittlerweile gut charakterisiert. {\"U}ber Mechanismen und Produkte, die den NKCC2 deaktivieren, war hingegen weniger bekannt. Ziel der Arbeit war daher zu untersuchen, welche Wege zur Deaktivierung des Transporters f{\"u}hren. Der intrazellul{\"a}re Sortierungsrezeptor SORLA (Sorting-protein-related receptor with A-type repeats) war zuvor in seiner Bedeutung f{\"u}r das Nephron charakterisiert worden. Ein SORLA-defizientes Mausmodell weist unter anderem eine stark verringerte NKCC2-Phosphorylierung auf. Unter osmotischem Stress k{\"o}nnen SORLA-defiziente M{\"a}use ihren Urin weniger effizient konzentrieren. Meine Resultate zeigen mit hochaufl{\"o}sender Technik, dass SORLA apikal im TAL lokalisiert ist und dass mit NKCC2 eine anteilige Kolokalisation besteht. Unter SORLA Defizienz war die f{\"u}r die NKCC2 Aktivit{\"a}t maßgebliche SPAK/OSR1-Phosphorylierung gegen{\"u}ber dem Wildtyp nicht ver{\"a}ndert. Jedoch war die ebenfalls im TAL exprimierte Phosphatase Calcineurin Aβ (CnAβ) per Western blot um das zweifache gesteigert. Parallel hierzu wurde immunhistochemisch die Kolokalisation von verst{\"a}rktem CnAβ-Signal und NKCC2 best{\"a}tigt. Beide Befunde geben zusammen den Hinweis auf einen Bezug zwischen der reduzierten NKCC2-Phosphorylierung und der gesteigerten Pr{\"a}senz von CnAβ bei SORLA Defizienz. Die parallel induzierte {\"U}berexpression von SORLA in HEK-Zellen zeigte entsprechend eine Halbierung der CnAβ Proteinmenge. SORLA steuert demzufolge sowohl die Abundanz als auch die zellul{\"a}re Verteilung der Phosphatase. Weiterhin ließ sich die Interaktion zwischen CnAβ und SORLA (intrazellul{\"a}re Dom{\"a}ne) mittels Co-Immunpr{\"a}zipitation bzw. GST-pulldown assay nachweisen. Auch die Interaktion zwischen CnAβ und NKCC2 wurde auf diesem Weg belegt. Da allerdings weder SORLA noch NKCC2 ein spezifisches Bindungsmuster f{\"u}r CnAβ aufweisen, sind vermutlich intermedi{\"a}re Adapterproteine bei ihrer Bindung involviert. Die pharmakologische Inhibition von CnAβ mittels Cyclosporin A (CsA; 1 h) f{\"u}hrte bei SORLA Defizienz zur Normalisierung der NKCC2-Phosphorylierung. Entsprechend f{\"u}hrte in vitro die Gabe von CsA bei TAL Zellen zu einer 7-fach gesteigerten NKCC2-Phosphorylierung. Zusammenfassend zeigen die Ergebnisse, dass die Phosphatase CnAβ {\"u}ber ihre Assoziation mit NKCC2 diesen im adluminalen Zellkompartiment deaktivieren kann. Gesteuert wird dieser Vorgang durch die Eigenschaft von SORLA, CnAβ apikal zu reduzieren und damit die adluminale Phosphorylierung und Aktivit{\"a}t von NKCC2 zu unterst{\"u}tzen. Da Calcineurin-Inhibitoren derzeit die Grundlage der immunsupprimierenden Therapie darstellen, haben die Ergebnisse eine klinische Relevanz. Angesichts der Co-Expression von SORLA und CnAβ in verschiedenen anderen Organen k{\"o}nnen die Ergebnisse auch {\"u}ber die Niere hinaus Bedeutung erlangen.}, language = {de} } @phdthesis{Weckmann2015, author = {Weckmann, Ute}, title = {Die elektrische Leitf{\"a}higkeit von fossilen St{\"o}rungszonen und Mobile Belts}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88820}, school = {Universit{\"a}t Potsdam}, pages = {vi, VIII, 74}, year = {2015}, abstract = {In der vorliegenden Arbeit werden verschiedene Experimente zur Untersuchung der elektrischen Leitf{\"a}higkeit von Sutur- und Kollisionszonen im Zusammenhang diskutiert, um die M{\"o}glichkeiten, die die moderne Magnetotellurik (MT) f{\"u}r das Abbilden fossiler tektonischer Systeme bietet, aufzuzeigen. Aus den neuen hochaufl{\"o}senden Abbildern der elektrischen Leitf{\"a}higkeit k{\"o}nnen potentielle Gemeinsamkeiten verschiedener tektonischer Einheiten abgeleitet werden. Innerhalb der letzten Dekade haben sich durch die Weiterentwicklung der Messger{\"a}te und der Auswerte- und Interpretationsmethoden v{\"o}llig neue Perspektiven f{\"u}r die geodynamische Tiefensondierung ergeben. Dies wird an meinen Forschungsarbeiten deutlich, die ich im Rahmen von Projekten selbst eingeworben und am Deutschen GeoForschungsZentrum Potsdam durchgef{\"u}hrt habe. In Tabelle A habe ich die in dieser Arbeit ber{\"u}cksichtigten Experimente aufgef{\"u}hrt, die in den letzten Jahren entweder als Array- oder als Profilmessungen durchgef{\"u}hrt wurden. F{\"u}r derart große Feldexperimente ben{\"o}tigt man ein Team von WissenschaftlerInnen, StudentInnen und technischem Personal. Das bedeutet aber auch, dass von mir betreute StudentInnen und DoktorandInnen Teilaspekte dieser Experimente in Form von Diplom-, Bachelor- und Mastersarbeiten oder Promotionsschriften verarbeitet haben. Bei anschließender Ver{\"o}ffentlichung der Arbeiten habe ich als Co-Autor mitgewirkt. Die beiliegenden Ver{\"o}ffentlichungen enthalten eine Einf{\"u}hrung in die Methode der Magnetotellurik und gegebenenfalls die Beschreibung neu entwickelter Methoden. Eine allgemeine Darstellung der theoretischen Grundlagen der Magnetotellurik findet man zum Beispiel in Chave \& Jones (2012); Simpson \& Bahr (2005); Kaufman \& Keller (1981); Nabighian (1987); Weaver (1994). Die Arbeit beinhaltet zudem ein Glossar, in dem einige Begriffe und Abk{\"u}rzungen erkl{\"a}rt werden. Ich habe mich entschieden, Begriffe, f{\"u}r die es keine ad{\"a}quate deutsche {\"U}bersetzung gibt oder die im Deutschen eine andere oder missverst{\"a}ndliche Bedeutung bekommen, auf Englisch in der Arbeit zu belassen. Sie sind durch eine kursive Schreibweise gekennzeichnet.}, language = {de} } @phdthesis{Cattania2015, author = {Cattania, Camilla}, title = {Improvement of aftershock models based on Coulomb stress changes and rate-and-state dependent friction}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87097}, school = {Universit{\"a}t Potsdam}, pages = {xvi, 123}, year = {2015}, abstract = {Earthquake clustering has proven the most useful tool to forecast changes in seismicity rates in the short and medium term (hours to months), and efforts are currently being made to extend the scope of such models to operational earthquake forecasting. The overarching goal of the research presented in this thesis is to improve physics-based earthquake forecasts, with a focus on aftershock sequences. Physical models of triggered seismicity are based on the redistribution of stresses in the crust, coupled with the rate-and-state constitutive law proposed by Dieterich to calculate changes in seismicity rate. This type of models are known as Coulomb- rate and-state (CRS) models. In spite of the success of the Coulomb hypothesis, CRS models typically performed poorly in comparison to statistical ones, and they have been underepresented in the operational forecasting context. In this thesis, I address some of these issues, and in particular these questions: (1) How can we realistically model the uncertainties and heterogeneity of the mainshock stress field? (2) What is the effect of time dependent stresses in the postseismic phase on seismicity? I focus on two case studies from different tectonic settings: the Mw 9.0 Tohoku megathrust and the Mw 6.0 Parkfield strike slip earthquake. I study aleatoric uncertainties using a Monte Carlo method. I find that the existence of multiple receiver faults is the most important source of intrinsic stress heterogeneity, and CRS models perform better when this variability is taken into account. Epistemic uncertainties inherited from the slip models also have a significant impact on the forecast, and I find that an ensemble model based on several slip distributions outperforms most individual models. I address the role of postseismic stresses due to aseismic slip on the mainshock fault (afterslip) and to the redistribution of stresses by previous aftershocks (secondary triggering). I find that modeling secondary triggering improves model performance. The effect of afterslip is less clear, and difficult to assess for near-fault aftershocks due to the large uncertainties of the afterslip models. Off-fault events, on the other hand, are less sensitive to the details of the slip distribution: I find that following the Tohoku earthquake, afterslip promotes seismicity in the Fukushima region. To evaluate the performance of the improved CRS models in a pseudo-operational context, I submitted them for independent testing to a collaborative experiment carried out by CSEP for the 2010-2012 Canterbury sequence. Preliminary results indicate that physical models generally perform well compared to statistical ones, suggesting that CRS models may have a role to play in the future of operational forecasting. To facilitate efforts in this direction, and to enable future studies of earthquake triggering by time dependent processes, I have made the code open source. In the final part of this thesis I summarize the capabilities of the program and outline technical aspects regarding performance and parallelization strategies.}, language = {en} } @phdthesis{Jehannin2015, author = {Jehannin, Marie}, title = {About the role of physico-chemical properties and hydrodynamics on the progress of a precipitation reaction}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88364}, school = {Universit{\"a}t Potsdam}, pages = {xii, 130}, year = {2015}, abstract = {The size and morphology control of precipitated solid particles is a major economic issue for numerous industries. For instance, it is interesting for the nuclear industry, concerning the recovery of radioactive species from used nuclear fuel. The precipitates features, which are a key parameter from the post-precipitate processing, depend on the process local mixing conditions. So far, the relationship between precipitation features and hydrodynamic conditions have not been investigated. In this study, a new experimental configuration consisting of coalescing drops is set to investigate the link between reactive crystallization and hydrodynamics. Two configurations of aqueous drops are examined. The first one corresponds to high contact angle drops (>90°) in oil, as a model system for flowing drops, the second one correspond to sessile drops in air with low contact angle (<25°). In both cases, one reactive is dissolved in each drop, namely oxalic acid and cerium nitrate. When both drops get into contact, they may coalesce; the dissolved species mix and react to produce insoluble cerium oxalate. The precipitates features and effect on hydrodynamics are investigated depending on the solvent. In the case of sessile drops in air, the surface tension difference between the drops generates a gradient which induces a Marangoni flow from the low surface tension drop over the high surface tension drop. By setting the surface tension difference between the two drops and thus the Marangoni flow, the hydrodynamics conditions during the drop coalescence could be modified. Diols/water mixtures are used as solvent, in order to fix the surface tension difference between the liquids of both drops regardless from the reactant concentration. More precisely, the used diols, 1,2-propanediol and 1,3-propanediol, are isomer with identical density and close viscosity. By keeping the water volume fraction constant and playing with the 1,2-propanediol and 1,3-propanediol volume fractions of the solvents, the mixtures surface tensions differ up to 10 mN/m for identical/constant reactant concentration, density and viscosity. 3 precipitation behaviors were identified for the coalescence of water/diols/recatants drops depending on the oxalic excess. The corresponding precipitates patterns are visualized by optical microscopy and the precipitates are characterized by confocal microscopy SEM, XRD and SAXS measurements. In the intermediate oxalic excess regime, formation of periodic patterns can be observed. These patterns consist in alternating cerium oxalate precipitates with distinct morphologies, namely needles and "microflowers". Such periodic fringes can be explained by a feedback mechanism between convection, reaction and the diffusion.}, language = {en} } @phdthesis{Bora2015, author = {Bora, Sanjay Singh}, title = {Regionally adaptable ground-motion Prediction Equations (GMPEs) for seismic hazard analysis}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88806}, school = {Universit{\"a}t Potsdam}, pages = {xiv, 138}, year = {2015}, abstract = {Adjustment of empirically derived ground motion prediction equations (GMPEs), from a data- rich region/site where they have been derived to a data-poor region/site, is one of the major challenges associated with the current practice of seismic hazard analysis. Due to the fre- quent use in engineering design practices the GMPEs are often derived for response spectral ordinates (e.g., spectral acceleration) of a single degree of freedom (SDOF) oscillator. The functional forms of such GMPEs are based upon the concepts borrowed from the Fourier spectral representation of ground motion. This assumption regarding the validity of Fourier spectral concepts in the response spectral domain can lead to consequences which cannot be explained physically. In this thesis, firstly results from an investigation that explores the relationship between Fourier and response spectra, and implications of this relationship on the adjustment issues of GMPEs, are presented. The relationship between the Fourier and response spectra is explored by using random vibration theory (RVT), a framework that has been extensively used in earthquake engineering, for instance within the stochastic simulation framework and in the site response analysis. For a 5\% damped SDOF oscillator the RVT perspective of response spectra reveals that no one-to-one correspondence exists between Fourier and response spectral ordinates except in a limited range (i.e., below the peak of the response spectra) of oscillator frequencies. The high oscillator frequency response spectral ordinates are dominated by the contributions from the Fourier spectral ordinates that correspond to the frequencies well below a selected oscillator frequency. The peak ground acceleration (PGA) is found to be related with the integral over the entire Fourier spectrum of ground motion which is in contrast to the popularly held perception that PGA is a high-frequency phenomenon of ground motion. This thesis presents a new perspective for developing a response spectral GMPE that takes the relationship between Fourier and response spectra into account. Essentially, this frame- work involves a two-step method for deriving a response spectral GMPE: in the first step two empirical models for the FAS and for a predetermined estimate of duration of ground motion are derived, in the next step, predictions from the two models are combined within the same RVT framework to obtain the response spectral ordinates. In addition to that, a stochastic model based scheme for extrapolating the individual acceleration spectra beyond the useable frequency limits is also presented. To that end, recorded acceleration traces were inverted to obtain the stochastic model parameters that allow making consistent extrapola- tion in individual (acceleration) Fourier spectra. Moreover an empirical model, for a dura- tion measure that is consistent within the RVT framework, is derived. As a next step, an oscillator-frequency-dependent empirical duration model is derived that allows obtaining the most reliable estimates of response spectral ordinates. The framework of deriving the response spectral GMPE presented herein becomes a self-adjusting model with the inclusion of stress parameter (∆σ) and kappa (κ0) as the predictor variables in the two empirical models. The entire analysis of developing the response spectral GMPE is performed on recently compiled RESORCE-2012 database that contains recordings made from Europe, the Mediterranean and the Middle East. The presented GMPE for response spectral ordinates should be considered valid in the magnitude range of 4 ≤ MW ≤ 7.6 at distances ≤ 200 km.}, language = {en} } @phdthesis{Wallenta2015, author = {Wallenta, Daniel}, title = {Sequences of compact curvature}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87489}, school = {Universit{\"a}t Potsdam}, pages = {viii, 73}, year = {2015}, abstract = {By perturbing the differential of a (cochain-)complex by "small" operators, one obtains what is referred to as quasicomplexes, i.e. a sequence whose curvature is not equal to zero in general. In this situation the cohomology is no longer defined. Note that it depends on the structure of the underlying spaces whether or not an operator is "small." This leads to a magical mix of perturbation and regularisation theory. In the general setting of Hilbert spaces compact operators are "small." In order to develop this theory, many elements of diverse mathematical disciplines, such as functional analysis, differential geometry, partial differential equation, homological algebra and topology have to be combined. All essential basics are summarised in the first chapter of this thesis. This contains classical elements of index theory, such as Fredholm operators, elliptic pseudodifferential operators and characteristic classes. Moreover we study the de Rham complex and introduce Sobolev spaces of arbitrary order as well as the concept of operator ideals. In the second chapter, the abstract theory of (Fredholm) quasicomplexes of Hilbert spaces will be developed. From the very beginning we will consider quasicomplexes with curvature in an ideal class. We introduce the Euler characteristic, the cone of a quasiendomorphism and the Lefschetz number. In particular, we generalise Euler's identity, which will allow us to develop the Lefschetz theory on nonseparable Hilbert spaces. Finally, in the third chapter the abstract theory will be applied to elliptic quasicomplexes with pseudodifferential operators of arbitrary order. We will show that the Atiyah-Singer index formula holds true for those objects and, as an example, we will compute the Euler characteristic of the connection quasicomplex. In addition to this we introduce geometric quasiendomorphisms and prove a generalisation of the Lefschetz fixed point theorem of Atiyah and Bott.}, language = {en} } @phdthesis{Hogenacker2015, author = {Hogenacker, Jens}, title = {Essays on the transition from unemployment to employment with a special emphasis on start-up subsidies in Germany}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87464}, school = {Universit{\"a}t Potsdam}, pages = {xvi, 272}, year = {2015}, abstract = {The promotion of self-employment as part of active labor market policies is considered to be one of the most important unemployment support schemes in Germany. Against this background the main part of this thesis contributes to the evaluation of start-up support schemes within ALMP. Chapter 2 and 4 focus on the evaluation of the New Start-up Subsidy (NSUS, Gr{\"u}ndungszuschuss) in its first version (from 2006 to the end of 2011). The chapters offer an advancement of the evaluation of start-up subsidies in Germany, and are based on a novel data set of administrative data from the Federal Employment Agency that was enriched with information from a telephone survey. Chapter 2 provides a thorough descriptive analysis of the NSUS that consists of two parts. First, the participant structure of the program is compared with the one of two former programs. In a second step, the study conducts an in-depth characterization of the participants of the NSUS focusing on founding motives, the level of start-up capital and equity used as well as the sectoral distribution of the new business. Furthermore, the business survival, income situation of founders and job creation by the new businesses is analyzed during a period of 19 months after start-up. The contribution of Chapter 4 is to introduce a new explorative data set that allows comparing subsidized start-ups out of unemployment with non-subsidized business start-ups that were founded by individuals who were not unemployed at the time of start-up. Because previous evaluation studies commonly used eligible non-participants amongst the unemployed as control group to assess the labor market effects of the start-up subsidies, the corresponding results hence referred to the effectiveness of the ALMP measure, but could not address the question whether the subsidy leads to similarly successful and innovative businesses compared to non-subsidized businesses. An assessment of this economic/growth aspect is also important, since the subsidy might induce negative effects that may outweigh the positive effects from an ALMP perspective. The main results of Chapter 4 indicate that subsidized founders seem to have no shortages in terms of formal education, but exhibit less employment and industry-specific experience, and are less likely to benefit from intergenerational transmission of start-ups. Moreover, the study finds evidence that necessity start-ups are over-represented among subsidized business founders, which suggests disadvantages in terms of business preparation due to possible time restrictions right before start-up. Finally, the study also detects more capital constraints among the unemployed, both in terms of the availability of personal equity and access to loans. With respect to potential differences between both groups in terms of business development over time, the results indicate that subsidized start-ups out of unemployment face higher business survival rates 19 months after start-up. However, they lag behind regular business founders in terms of income, business growth, and innovation. The arduous data collection process for start-up activities of non-subsidized founders for Chapter 4 made apparent that Germany is missing a central reporting system for business formations. Additionally, the different start-up reporting systems that do exist exhibit substantial discrepancies in data processing procedures, and therefore also in absolute numbers concerning the overall start-up activity. Chapter 3 is therefore placed in front of Chapter 4 and has the aim to provide a comprehensive review of the most important German start-up reporting systems. The second part of the thesis consists of Chapter 5 which contributes to the literature on determinants of job search behavior of the unemployed individuals by analyzing the effectiveness of internet search with regard to search behavior of unemployed individuals and subsequent job quality. The third and final part of the thesis outlines why the German labor market reacted in a very mild fashion to the Great Recession 2008/09, especially compared to other countries. Chapter 6 describes current economic trends of the labor market in light of general trends in the European Union, and reveals some of the main associated challenges. Thereafter, recent reforms of the main institutional settings of the labor market which influence labor supply are analyzed. Finally, based on the status quo of these institutional settings, the chapter gives a brief overview of strategies to adequately combat the challenges in terms of labor supply and to ensure economic growth in the future.}, language = {en} } @phdthesis{Zajnulina2015, author = {Zajnulina, Marina}, title = {Optical frequency comb generation in optical fibres}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88776}, school = {Universit{\"a}t Potsdam}, pages = {xii, 103}, year = {2015}, abstract = {Optical frequency combs (OFC) constitute an array of phase-correlated equidistant spectral lines with nearly equal intensities over a broad spectral range. The adaptations of combs generated in mode-locked lasers proved to be highly efficient for the calibration of high-resolution (resolving power > 50000) astronomical spectrographs. The observation of different galaxy structures or the studies of the Milky Way are done using instruments in the low- and medium resolution range. To such instruments belong, for instance, the Multi Unit Spectroscopic Explorer (MUSE) being developed for the Very Large Telescope (VLT) of the European Southern Observatory (ESO) and the 4-metre Multi-Object Spectroscopic Telescope (4MOST) being in development for the ESO VISTA 4.1 m Telescope. The existing adaptations of OFC from mode-locked lasers are not resolvable by these instruments. Within this work, a fibre-based approach for generation of OFC specifically in the low- and medium resolution range is studied numerically. This approach consists of three optical fibres that are fed by two equally intense continuous-wave (CW) lasers. The first fibre is a conventional single-mode fibre, the second one is a suitably pumped amplifying Erbium-doped fibre with anomalous dispersion, and the third one is a low-dispersion highly nonlinear optical fibre. The evolution of a frequency comb in this system is governed by the following processes: as the two initial CW-laser waves with different frequencies propagate through the first fibre, they generate an initial comb via a cascade of four-wave mixing processes. The frequency components of the comb are phase-correlated with the original laser lines and have a frequency spacing that is equal to the initial laser frequency separation (LFS), i.e. the difference in the laser frequencies. In the time domain, a train of pre-compressed pulses with widths of a few pico-seconds arises out of the initial bichromatic deeply-modulated cosine-wave. These pulses undergo strong compression in the subsequent amplifying Erbium-doped fibre: sub-100 fs pulses with broad OFC spectra are formed. In the following low-dispersion highly nonlinear fibre, the OFC experience a further broadening and the intensity of the comb lines are fairly equalised. This approach was mathematically modelled by means of a Generalised Nonlinear Schr{\"o}dinger Equation (GNLS) that contains terms describing the nonlinear optical Kerr effect, the delayed Raman response, the pulse self-steepening, and the linear optical losses as well as the wavelength-dependent Erbium gain profile for the second fibre. The initial condition equation being a deeply-modulated cosine-wave mimics the radiation of the two initial CW lasers. The numerical studies are performed with the help of Matlab scripts that were specifically developed for the integration of the GNLS and the initial condition according to the proposed approach for the OFC generation. The scripts are based on the Fourth-Order Runge-Kutta in the Interaction Picture Method (RK4IP) in combination with the local error method. This work includes the studies and results on the length optimisation of the first and the second fibre depending on different values of the group-velocity dispersion of the first fibre. Such length optimisation studies are necessary because the OFC have the biggest possible broadband and exhibit a low level of noise exactly at the optimum lengths. Further, the optical pulse build-up in the first and the second fibre was studied by means of the numerical technique called Soliton Radiation Beat Analysis (SRBA). It was shown that a common soliton crystal state is formed in the first fibre for low laser input powers. The soliton crystal continuously dissolves into separated optical solitons as the input power increases. The pulse formation in the second fibre is critically dependent on the features of the pulses formed in the first fibre. I showed that, for low input powers, an adiabatic soliton compression delivering low-noise OFC occurs in the second fibre. At high input powers, the pulses in the first fibre have more complicated structures which leads to the pulse break-up in the second fibre with a subsequent degradation of the OFC noise performance. The pulse intensity noise studies that were performed within the framework of this thesis allow making statements about the noise performance of an OFC. They showed that the intensity noise of the whole system decreases with the increasing value of LFS.}, language = {en} } @misc{Sauer2015, type = {Master Thesis}, author = {Sauer, Tim-Oliver}, title = {Quasi-condensation in low-dimensional Bose gases}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87247}, school = {Universit{\"a}t Potsdam}, pages = {154}, year = {2015}, abstract = {The subject of the present thesis is the one-dimensional Bose gas. Since long-rang order is destroyed by infra-red fluctuations in one dimension, only the formation of a quasi-condensate is possible, which exhibits suppressed density fluctuations, but whose phase fluctuates strongly. It is shown that modified mean-field theories based on a symmetry-breaking approach can even characterise phase coherence properties of such a quasi-condensate properly. A correct description of the transition from the degenerate ideal Bose gas to the quasi-condensate, which is a smooth cross-over rather than a phase transition, is not possible though. Basic conditions for the applicability of the theories are not fulfilled in this regime, such that the existence of a critical point is predicted. The theories are compared on the basis of their excitation sprectum, equation of state, density fluctuations and related correlation functions. High-temperature expansions of the corresponding integrals are derived analytically for the numerical evaluation of the self-consistent integral equations. Apart from that, the Stochastic Gross-Pitaevskii equation (SGPE), a non-linear Langevin equation, is analysed numerically by means of Monte-Carlo simulations and the results are compared to those of the mean-field theories. In this context, a lot of attention is payed to the appropriate choice of the parameters. The simulations prove that the SGPE is capable of describing the cross-over properly, but highlight the limitations of the widely used local density approximation as well.}, language = {en} } @phdthesis{Otto2015, author = {Otto, Katharina Alexandra}, title = {Mass wasting and the Coriolis effect on asteroid Vesta}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87390}, school = {Universit{\"a}t Potsdam}, pages = {XVII, 251}, year = {2015}, abstract = {This work investigates the influence of the Coriolis force on mass motion related to the Rheasilvia impact basin on asteroid (4) Vesta's southern hemisphere. The giant basin is 500km in diameter, with a centre which nearly coincides with the rotation axis of Vesta. The Rheasilvia basin partially overlaps an earlier, similarly large impact basin, Veneneia. Mass motion within and in the vicinity of the Rheasilvia basin includes slumping and landslides, which, primarily due to their small linear extents, have not been noticeably affected by the Coriolis force. However, a series of ridges related to the basin exhibit significant curvature, which may record the effect of the Coriolis force on the mass motion which generated them. In this thesis 32 of these curved ridges, in three geologically distinct regions, were examined. The mass motion velocities from which the ridge curvatures may have resulted during the crater modification stage were investigated. Velocity profiles were derived by fitting inertial circles along the curved ridges and considering both the current and past rotation states of Vesta. An iterative, statistical approach was used, whereby the radii of inertial circles were obtained through repeated fitting to triplets of points across the ridges. The most frequently found radius for each central point was then used for velocity derivation at that point. The results of the velocity analysis are strongly supportive of a Coriolis force origin for the curved ridges. Derived velocities (29.6 ± 24.6 m/s) generally agree well with previously published predictions from numerical simulations of mass motion during the impact process. Topographical features such as local slope gradient and mass deposition regions on the curved ridges also independently agree with regions in which the calculated mass motion accelerates or decelerates. Sections of constant acceleration, deceleration and constant velocity are found, showing that mass motion is being governed by varying conditions of topography, regolith structure and friction. Estimates of material properties such as the effective viscosities (1.9-9.0·10⁶ Pa·s) and coefficients of friction (0.02-0.81) are derived from the velocity profile information in these sections. From measured accelerations of mass motions on the crater wall, it is also shown that the crater walls must have been locally steeper at the time of the mass motion. Together with these novel insights into the state and behaviour of material moving during the modification stage of Rheasilvia's formation, this work represents the first time that the Coriolis Effect on mass motions during crater formation has been shown to result in diagnostic features preserved until today.}, language = {en} } @article{Pflueger2015, author = {Pfl{\"u}ger, Georg A.}, title = {Erfahrungsbericht der Schulgenossenschaft F. W. Raiffeisen- Schule e. G. Wetzlar}, series = {Schulen im kommunalen Bildungsmanagement}, journal = {Schulen im kommunalen Bildungsmanagement}, editor = {Bauer, Hartmut and B{\"u}chner, Christiane and Markmann, Friedrich}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88648}, pages = {149 -- 155}, year = {2015}, language = {de} } @article{Thies2015, author = {Thies, Heike}, title = {Kooperationsoptionen zwischen {\"o}ffentlichen und privaten Schulen}, series = {Schulen im kommunalen Bildungsmanagement}, journal = {Schulen im kommunalen Bildungsmanagement}, editor = {Bauer, Hartmut and B{\"u}chner, Christiane and Markmann, Friedrich}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88637}, pages = {135 -- 148}, year = {2015}, language = {de} } @article{Grosse2015, author = {Große, Gerrit}, title = {Privatschulen in der kommunalen Bildungslandschaft}, series = {Schulen im kommunalen Bildungsmanagement}, journal = {Schulen im kommunalen Bildungsmanagement}, editor = {Bauer, Hartmut and B{\"u}chner, Christiane and Markmann, Friedrich}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88626}, pages = {129 -- 133}, year = {2015}, language = {de} } @article{Rombey2015, author = {Rombey, Wolfgang}, title = {Erfolgsfaktoren einer kommunalen Bildungslandschaft}, series = {Schulen im kommunalen Bildungsmanagement}, journal = {Schulen im kommunalen Bildungsmanagement}, editor = {Bauer, Hartmut and B{\"u}chner, Christiane and Markmann, Friedrich}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88604}, pages = {100 -- 126}, year = {2015}, language = {de} } @article{Kluth2015, author = {Kluth, Winfried}, title = {Rechtliche Rahmenbedingungen f{\"u}r interkommunale Kooperation im Schulsektor}, series = {Schulen im kommunalen Bildungsmanagement}, journal = {Schulen im kommunalen Bildungsmanagement}, editor = {Bauer, Hartmut and B{\"u}chner, Christiane and Markmann, Friedrich}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88592}, pages = {83 -- 98}, year = {2015}, language = {de} } @article{Glittenberg2015, author = {Glittenberg, Barbara}, title = {E-Learning}, series = {Schulen im kommunalen Bildungsmanagement}, journal = {Schulen im kommunalen Bildungsmanagement}, editor = {Bauer, Hartmut and B{\"u}chner, Christiane and Markmann, Friedrich}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88581}, pages = {67 -- 80}, year = {2015}, language = {de} } @article{Boettcher2015, author = {B{\"o}ttcher, Karl-Ludwig}, title = {Modelle zur Sicherung von Schulstandorten aus Brandenburger Sicht}, series = {Schulen im kommunalen Bildungsmanagement}, journal = {Schulen im kommunalen Bildungsmanagement}, editor = {Bauer, Hartmut and B{\"u}chner, Christiane and Markmann, Friedrich}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88573}, pages = {61 -- 66}, year = {2015}, language = {de} } @article{Hebeler2015, author = {Hebeler, Timo}, title = {Schulen der Zukunft}, series = {Schulen im kommunalen Bildungsmanagement}, journal = {Schulen im kommunalen Bildungsmanagement}, editor = {Bauer, Hartmut and B{\"u}chner, Christiane and Markmann, Friedrich}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88569}, pages = {51 -- 59}, year = {2015}, language = {de} } @article{Becker2015, author = {Becker, Ulrike}, title = {Inklusion f{\"u}r alle}, series = {Schulen im kommunalen Bildungsmanagement}, journal = {Schulen im kommunalen Bildungsmanagement}, editor = {Bauer, Hartmut and B{\"u}chner, Christiane and Markmann, Friedrich}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88550}, pages = {43 -- 49}, year = {2015}, language = {de} } @article{Wichmann2015, author = {Wichmann, Maren}, title = {Zukunftsmodell Ganztagsschule}, series = {Schulen im kommunalen Bildungsmanagement}, journal = {Schulen im kommunalen Bildungsmanagement}, editor = {Bauer, Hartmut and B{\"u}chner, Christiane and Markmann, Friedrich}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88548}, pages = {27 -- 42}, year = {2015}, language = {de} } @article{BauerMarkmann2015, author = {Bauer, Hartmut and Markmann, Friedrich}, title = {Schulen im kommunalen Bildungsmanagement}, series = {Schulen im kommunalen Bildungsmanagement}, journal = {Schulen im kommunalen Bildungsmanagement}, editor = {Bauer, Hartmut and B{\"u}chner, Christiane and Markmann, Friedrich}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88534}, pages = {11 -- 23}, year = {2015}, language = {de} } @techreport{Buss2015, type = {Working Paper}, author = {Buß, Claudia}, title = {Die Modernisierung der kommunalen R{\"a}te - Aber wie?}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-84200}, pages = {98}, year = {2015}, abstract = {Die Mitglieder der Stadtr{\"a}te in den großen deutschen St{\"a}dten sind ehrenamtlich t{\"a}tig und m{\"u}ssen große Herausforderungen, wie die Europ{\"a}isierung der lokalen Ebene oder die Finanzierungsl{\"u}cken im kommunalen Haushalt, bew{\"a}ltigen. Die Ehren{\"a}mtler m{\"u}ssen die Aufgabenbelastung durch Professionalisierungsmechanismen ausgleichen. Welche Arten der Professionalisierungsbed{\"u}rfnisse liegen aber vor und sollten in den deutschen St{\"a}dten gepr{\"u}ft werden? Diese Arbeit besch{\"a}ftigt sich mit konkreten Ver{\"a}nderungen vor Ort, um die Faktoren Zeiteffektivit{\"a}t, Tranzparenz und Informationsverarbeitung zu verbessern. Das empirische Beispiel Potsdam wurde f{\"u}r die Analayse ausgew{\"a}hlt, da {\"u}berdurchschnittlich lang und h{\"a}ufig getagt wird. Die Indikatoren Fraktionsgr{\"o}ße, Positionsmenge oder Engagementl{\"a}nge sollen aufzeigen, in welchem konkreten Rahmen Ver{\"a}nderungen n{\"o}tig und auch gewollt sind. Die Arbeit soll andere St{\"a}dte zur {\"U}berpr{\"u}fung ihrer eigenen R{\"a}te anregen. Daraus ergibt sich die Frage, ob die Belastung der Mitglieder der Stadtr{\"a}te und Stadtverordnetenversammlungen so groß geworden ist, dass Deutschland gar eine dritte f{\"o}derale Ebene ben{\"o}tigt, um die Aufgaben zu bew{\"a}ltigen. Ist nicht eine schleichende dritte Ebene in der Realit{\"a}t bereits vorhanden. Die Analysekriterien sind der zeitliche Umfang des Engagements, die finanzielle Kompensierung der Ehrenamtlichkeit und die Elemente der Parlamentarisierung.}, subject = {Professionalisierung}, language = {de} } @phdthesis{Kulikova2015, author = {Kulikova, Galina}, title = {Source parameters of the major historical earthquakes in the Tien-Shan region from the late 19th to the early 20th century}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88370}, school = {Universit{\"a}t Potsdam}, pages = {xiv, 164}, year = {2015}, abstract = {The Tien-Shan and the neighboring Pamir region are two of the largest mountain belts in the world. Their deformation is dominated by intermontane basins bounded by active thrust and reverse faulting. The Tien-Shan mountain belt is characterized by a very high rate of seismicity along its margins as well as within the Tien-Shan interior. The study area of the here presented thesis, the western part of the Tien-Shan region, is currently seismically active with small and moderate sized earthquakes. However, at the end of the 19th beginning of the 20th century, this region was struck by a remarkable series of large magnitude (M>7) earthquakes, two of them reached magnitude 8. Those large earthquakes occurred prior to the installation of the global digital seismic network and therefore were recorded only by analog seismic instruments. The processing of the analog data brings several difficulties, for example, not always the true parameters of the recording system are known. Another complicated task is the digitization of those records - a very time-consuming and delicate part. Therefore a special set of techniques is developed and modern methods are adapted for the digitized instrumental data analysis. The main goal of the presented thesis is to evaluate the impact of large magnitude M≥7.0 earthquakes, which occurred at the turn of 19th to 20th century in the Tien-Shan region, on the overall regional tectonics. A further objective is to investigate the accuracy of previously estimated source parameters for those earthquakes, which were mainly based on macroseismic observations, and re-estimate them based on the instrumental data. An additional aim of this study is to develop the tools and methods for faster and more productive usage of analog seismic data in modern seismology. In this thesis, the ten strongest and most interesting historical earthquakes in Tien-Shan region are analyzed. The methods and tool for digitizing and processing the analog seismic data are presented. The source parameters of the two major M≥8.0 earthquakes in the Northern Tien-Shan are re-estimated in individual case studies. Those studies are published as peer-reviewed scientific articles in reputed journals. Additionally, the Sarez-Pamir earthquake and its connection with one of the largest landslides in the world, Usoy landslide, is investigated by seismic modeling. These results are also published as a research paper. With the developed techniques, the source parameters of seven more major earthquakes in the region are determined and their impact on the regional tectonics was investigated. The large magnitudes of those earthquakes are confirmed by instrumental data. The focal mechanism of these earthquakes were determined providing evidence for responsible faults or fault systems.}, language = {en} } @article{SugawaraTsuboiMaedaetal.2015, author = {Sugawara, Y. and Tsuboi, Y. and Maeda, Y. and Pollock, A. M. T. and Williams, P. M.}, title = {The Swift monitoring of the colliding wind binary WR 21a}, series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015}, journal = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88517}, pages = {366}, year = {2015}, abstract = {The X-ray observations of the colliding wind binary WR 21a is reported. The first monitoring performed by Swift/XRT in order to reveal the phase-locked variation. Our observations cover 201 different epochs from 2013 October 1 to 2015 January 30 for a total exposure of about 306 ks. It is found for the first time that the luminosity varies roughly in inverse proportion to the separation of the two stars before the X-ray maximum but later drops rapidly toward periastron.}, language = {en} } @article{SteinkeOskinovaHamannetal.2015, author = {Steinke, M. and Oskinova, Lidia M. and Hamann, Wolf-Rainer and Sander, A.}, title = {The Wolf-Rayet stars WR102c and 102ka and their isolation}, series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015}, journal = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88503}, pages = {365}, year = {2015}, abstract = {While the majority of very massive stars is clearly found in clusters, there are also very massive objects not associated with any cluster, suggesting they may have been born in isolation. In order to gain more insights, we studied the regions around two WR stars in the Galactic Center region. To understand the nature of the potential cluster around massive stars, photometry alone is not sufficient. We therefore used the ESO VLT/SINFONI integral field spectrograph to obtain photometry and spectra for the whole region around our two candidate stars. In total, more than 60 stars have been found and assigned a spectral type.}, language = {en} } @article{RoMatzner2015, author = {Ro, S. and Matzner, C. D.}, title = {Envelope Inflation or Stellar Wind?}, series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015}, journal = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88491}, pages = {364}, year = {2015}, abstract = {We an optically-thick, transonic, steady wind model for a H-free Wolf-Rayet star. A bifurcation is found across a critical mass loss rate Mb. Slower winds M < Mb extend by several hydrostatic stellar radii, reproduce features of envelope in ation from Petrovic et al. (2006) and Gr{\"a}fener et al. (2012), and are energetically unbound. This work is of particular interest for extended envelopes and winds, radiative hydrodynamic instabilities (eg. wind stagnation, clumping, etc.), and NLTE atmospheric models.}, language = {en} }