@phdthesis{Eskelson2018,
  author    = {Eskelson, Daniela},
  title     = {The market of sustainable and responsible investment},
  school      = {Universit{\"a}t Potsdam},
  pages     = {412, IXXiii},
  year      = {2018},
  language  = {en}
}
@phdthesis{Zuba2018,
  author    = {Zuba, Anna},
  title     = {The role of weight stigma and weight bias internalization in psychological functioning among school-aged children},
  school      = {Universit{\"a}t Potsdam},
  pages     = {146},
  year      = {2018},
  language  = {en}
}
@phdthesis{Lensing2018,
  author    = {Lensing, Johanna Nele},
  title     = {Executive Functions in Middle Childhood},
  school      = {Universit{\"a}t Potsdam},
  pages     = {159},
  year      = {2018},
  abstract  = {This doctoral dissertation aims at elucidating the development of hot and cool executive functions in middle childhood and at gaining insight about their role in childhood overweight. The dissertation is based on three empirical studies which have been published in peer-reviewed journals. Data from a large 3-year longitudinal study (the "PIER-study") was used. The findings presented in the dissertation demonstrated that both hot and cool EF abilities increase during middle childhood. They also supported the notion that hot and cool EF facets are distinguishable from each other in middle childhood, that they have distinct developmental trajectories, and different predictors. Evidence was found for associations of hot and cool EF with body weight in middle childhood, which is in line with the notion that they might play a role in the self-regulation of eating and the multifactorial etiology of childhood overweight.},
  language  = {en}
}
@phdthesis{Lawas2018,
  author    = {Lawas, Lovely Mae F.},
  title     = {Molecular characterization of rice exposed to heat and drought stress at flowering and early grain filling},
  pages     = {VII, 150},
  year      = {2018},
  language  = {en}
}
@phdthesis{Lange2018,
  author    = {Lange, Anne},
  title     = {On a small scale},
  school      = {Universit{\"a}t Potsdam},
  pages     = {337},
  year      = {2018},
  abstract  = {This study argues that micro relations matter in peacekeeping. Asking what makes the implementation of peacekeeping interventions complex and how complexity is resolved, I find that formal, contractual mechanisms only rarely effectively reduce complexity - and that micro relations fill this gap. Micro relations are personal relationships resulting from frequent face-to-face interaction in professional and - equally importantly - social contexts. This study offers an explanation as to why micro relations are important for coping with complexity, in the form of a causal mechanism. For this purpose, I bring together theoretical and empirical knowledge: I draw upon the current debate on 'institutional complexity' (Greenwood et al. 2011) in organizational institutionalism as well as original empirical evidence from a within-case study of the peacekeeping intervention in Haiti, gained in ten weeks of field research. In this study, scholarship on institutional complexity serves to identify theoretical causal channels which guide empirical analysis. An additional, secondary aim is pursued with this mechanism-centered approach: testing the utility of Beach and Pedersen's (2013) theory-testing process tracing. Regarding the first research question - what makes the implementation of peacekeeping interventions complex -, the central finding is that complexity manifests itself in the dual role of organizations as cooperation partners and competitors for (scarce) resources, turf and influence. UN organizations, donor agencies and international NGOs implementing peacekeeping activities in post-conflict environments have chronic difficulty mastering both roles because they entail contradictory demands: effective cooperation requires information exchange, resource and responsibility-sharing as well as external scrutiny, whereas prevailing over competitors demands that organizations conceal information, guard resources, increase relative turf and influence, as well as shield themselves from scrutiny. Competition fuels organizational distrust and friction - and impedes cooperation. How is this complexity resolved? The answer to this second research question is that deep-seated organizational competition is routinely mediated - and cooperation motivated - in micro relations and micro interaction. Regular, frequent face-to-face interaction between individual organizational members generates social resources that help to transcend organizational distrust and conflict, most importantly familiarity with each other, personal trust and belief in reciprocity. Furthermore, informal conflict mediation and control mechanisms - namely, open discussion, mutual monitoring in direct interaction and social exclusion - enhance solidarity and mutual support.},
  language  = {en}
}
@phdthesis{Hlawenka2018,
  author    = {Hlawenka, Peter},
  title     = {Samarium hexaboride},
  school      = {Universit{\"a}t Potsdam},
  pages     = {116, XXI},
  year      = {2018},
  language  = {en}
}
@phdthesis{Heucher2018,
  author    = {Heucher, Angela},
  title     = {Through IOs' Eyes},
  school      = {Universit{\"a}t Potsdam},
  pages     = {323},
  year      = {2018},
  abstract  = {Is global governance characterized by overlap and fragmentation, or by coordination and harmonization? There are two rather different narratives about the worlds in which international organizations (IOs) live. One way or another, IOs are part of a broader environment and engage in relations with other actors in it. Rather than being detached from their environment, IOs are shaped by and respond to developments taking place within it (e.g., overlap). Thus, the general research interest of this dissertation lies in organizational responses to such environmental developments. Therein, the emphasis is placed on IO positionality, meaning the position of an IO within a "web" of interorganizational relations, or, more precisely, an IO's position within an organizational field as a specification of the IO environment. Against this background, the dissertation poses the following research question: How does an IO's position within an organizational field shape its responses to developments of the field? In that, three subquestions are advanced: Which position does an IO occupy within the organizational field? How does an IO perceive the organizational field? How does an IO respond to developments and features of the field? Theoretically, the dissertation combines an open system perspective on IOs with two variants of field theory inspired by Bourdieu and by DiMaggio and Powell. Building on the central concept of the organizational field, the dissertation understands IOs as actors with agency. Empirically, the dissertation consists of a qualitative, comparative study and analyzes two IOs located within the organizational field of global food security governance. I select IOs that occupy different positions within the field of food security governance, namely an IO at the core of the field (the United Nations Food and Agriculture Organization, or FAO) and an IO at the periphery of the field (the United Nations Industrial Development Organization, or UNIDO). I compare and analyze their respective perceptions of the field of food security governance, including their own role and their understandings of food security, and their responses over time. To investigate these IOs' perceptions and responses over time, the method of choice consists of a qualitative content analysis of a wide range of organizational documents (e.g., governing bodies' reports). The main argument this dissertation advances is as follows: The position that an IO occupies within an organizational field influences how the organization perceives its environment—in particular, features of and developments within this environment. Against this background, the main findings of this dissertation are as follows: Overall, FAO and UNIDO both perceive proliferation, overlap, and duplication as relevant developments of the organizational field of global food security governance over time. While both IOs see developments in the field of food security governance (e.g., overlap and duplication) as problematic given their detrimental effects for food security governance, FAO and UNIDO differ in decisive regards. Whereas FAO holds a narrative that other actors were responsible for this state of affairs, and thus responsible for reducing or even eliminating overlap and duplication, UNIDO perceives these developments differently. UNIDO acknowledges its own role in the development of overlap and duplication, and therefore also sees a role for itself in addressing these developments. The two IOs thus differ in what they understand to be the causes and historical priors of field-specific developments. Furthermore, while both FAO and UNIDO attempt to demonstrate that they are constructive players within the UN development system, the two IOs differ in their responses: While FAO engages in balancing by voicing its commitment to UN processes and to coordination, yet early on making different reservations, UNIDO, in contrast, engages in UN processes without similar reservations. Accordingly, the two IOs also differ on the responses they employ to field-level harmonization demands. The dissertation makes several contributions. Theoretically, I contribute an innovative argument on the influence of perceptions for organizational responses to developments in the IOs' environment. This argument may help us to better understand how IOs as actors embedded within an organizational field deal with changes evolving within these fields. Empirically, I scrutinize developments in food security governance, such as proliferation and overlap, through the eyes of IOs in the field. While proliferation, overlap, and duplication are often referred to in academic debates on food security governance, we do not yet actually understand these phenomena very well. To this, I contribute a study that analyzes IO perceptions of these developments in the field, thus resulting in a more in-depth and nuanced picture of how IOs perceive these developments as a central type of actor in food security governance. Next, to this emphasis on the IO perspective, I also inductively develop a spectrum of IO responses to field developments, ranging from expanding scope to defending turf. Finally, I also make a methodological-conceptual contribution: While concepts such as "position" are well-known, they are sometimes drawn on without developing a clear foundation of how to assess different positions. I thus add an approach for bringing this concept of position to life by developing a range of criteria that can be used to approximate an IO's position within an organizational field, depending on different types of capital.},
  language  = {en}
}
@phdthesis{Willner2018,
  author    = {Willner, Sven N.},
  title     = {Global economic response to flood damages under climate change},
  school      = {Universit{\"a}t Potsdam},
  pages     = {v, 247},
  year      = {2018},
  abstract  = {Climate change affects societies across the globe in various ways. In addition to gradual changes in temperature and other climatic variables, global warming is likely to increase intensity and frequency of extreme weather events. Beyond biophysical impacts, these also directly affect societal and economic activity. Additionally, indirect effects can occur; spatially, economic losses can spread along global supply-chains; temporally, climate impacts can change the economic development trajectory of countries. This thesis first examines how climate change alters river flood risk and its local socio-economic implications. Then, it studies the global economic response to river floods in particular, and to climate change in general. Changes in high-end river flood risk are calculated for the next three decades on a global scale with high spatial resolution. In order to account for uncertainties, this assessment makes use of an ensemble of climate and hydrological models as well as a river routing model, that is found to perform well regarding peak river discharge. The results show an increase in high-end flood risk in many parts of the world, which require profound adaptation efforts. This pressure to adapt is measured as the enhancement in protection level necessary to stay at historical high-end risk. In developing countries as well as in industrialized regions, a high pressure to adapt is observed - the former to increase low protection levels, the latter to maintain the low risk levels perceived in the past. Further in this thesis, the global agent-based dynamic supply-chain model acclimate is developed. It models the cascading of indirect losses in the global supply network. As an anomaly model its agents - firms and consumers - maximize their profit locally to respond optimally to local perturbations. Incorporating quantities as well as prices on a daily basis, it is suitable to dynamically resolve the impacts of unanticipated climate extremes. The model is further complemented by a static measure, which captures the inter-dependencies between sectors across regions that are only connected indirectly. These higher-order dependencies are shown to be important for a comprehensive assessment of loss-propagation and overall costs of local disasters. In order to study the economic response to river floods, the acclimate model is driven by flood simulations. Within the next two decades, the increase in direct losses can only partially be compensated by market adjustments, and total losses are projected to increase by 17\% without further adaptation efforts. The US and the EU are both shown to receive indirect losses from China, which is strongly affected directly. However, recent trends in the trade relations leave the EU in a better position to compensate for these losses. Finally, this thesis takes a broader perspective when determining the investment response to the climate change damages employing the integrated assessment model DICE. On an optimal economic development path, the increase in damages is anticipated as emissions and consequently temperatures increase. This leads to a significant devaluation of investment returns and the income losses from climate damages almost double. Overall, the results highlight the need to adapt to extreme weather events - local physical adaptation measures have to be combined with regional and global policy measures to prepare the global supply-chain network to climate change.},
  language  = {en}
}
@phdthesis{Ring2018,
  author    = {Ring, Christiane},
  title     = {The role of the commensal gut bacterium Akkermansia muciniphila in acute and chronic intestinal inflammation},
  year      = {2018},
  abstract  = {Microbiota analyses of patients suffering from various diseases suggest a beneficial role of Akkermansia muciniphila in the maintenance of health, whereas several studies in animal models of intestinal inflammation report that this organism may aggravate inflammation. Therefore, it is important to clarify under which circumstances A. muciniphila exerts negative effects in the intestine of its host. The previously reported observation that A. muciniphila aggravates acute intestinal inflammation in the Salmonella enterica serovar Typhimurium infection mouse model colonized with a simplified human intestinal microbiota was investigated in this study. To unravel the underlying mechanism that led to the observed phenomenon, the time course of events following the infection was analyzed. In mice colonized with a simplified human intestinal microbiota, Salmonella infection induced clear signs of intestinal inflammation three days post infection. The inflammatory response was similar in mice colonized with A. muciniphila before Salmonella infection. These observations were independent of the time when colonization with the simplified human intestinal microbiota occurred, right after birth or only after weaning, and contradict the previous report. To find out whether A. muciniphila influences the development of chronic intestinal inflammation in a genetically predisposed host, mono-associated interleukin-10-deficient (Il10-/-) mice, Il10-/- mice dual-associated with A. muciniphila and colitogenic Escherichia coli NC101, as well as Il10-/- mice associated with A. muciniphila and a simplified human intestinal microbiota were compared to the respective mice without A. muciniphila. The data clearly show that in these gnotobiotic Il10-/- mice, A. muciniphila neither induces intestinal inflammation itself nor modulates it after induction by a colitogenic bacterium or by a simplified human intestinal microbiota. The experiments lead to the conclusion that the promotion of intestinal inflammation is not an intrinsic feature of this bacterium. The results of this study encourage the proposed use of A. muciniphila for the prevention or treatment of metabolic disorders.},
  language  = {en}
}
@phdthesis{Liebig2018,
  author    = {Liebig, Ferenc},
  title     = {Synthesis and characterization of superstructures based on gold nanotriangles},
  school      = {Universit{\"a}t Potsdam},
  pages     = {136},
  year      = {2018},
  language  = {en}
}
@phdthesis{Kuehn2018,
  author    = {K{\"u}hn, Danilo},
  title     = {Synchrotron-based angle-resolved time-of-flight electron spectroscopy for dynamics in dichalogenides},
  school      = {Universit{\"a}t Potsdam},
  pages     = {147},
  year      = {2018},
  language  = {en}
}
@phdthesis{Jende2018,
  author    = {Jende, Alexander},
  title     = {On the characterization of particular orthogroups by disjunctions of identities},
  school      = {Universit{\"a}t Potsdam},
  pages     = {112},
  year      = {2018},
  abstract  = {In this thesis, we discuss the characterization of orthogroups by so-called disjunctions of identities. The orthogroups are a subclass of the class of completely regular semigroups, a generalization of the concept of a group. Thus there is for all elements of an orthogroup some kind of an inverse element such that both elements commute. Based on a fundamental result by A.H. Clifford, every completely regular semigroup is a semilattice of completely simple semigroups. This allows the description the gross structure of such semigroup. In particular every orthogroup is a semilattice of rectangular groups which are isomorphic to direct products of rectangular bands and groups. Semilattices of rectangular groups coming from various classes are characterized using the concept of an alternative variety, a generalization of the classical idea of a variety by Birkhoff. After starting with some fundamental definitions and results concerning semigroups, we introduce the concept of disjunctions of identities and summarize some necessary properties. In particular we present some disjunction of identities which is sufficient for a semigroup for being completely regular. Furthermore we derive from this identity some statements concerning Rees matrix semigroups, a possible representation of completely simple semigroups. A main result of this thesis is the general description of disjunctions of identities such that a completely regular semigroup satisfying the described identity is a semilattice of left groups (right groups / groups). In this case the completely regular semigroup is an orthogroup. Furthermore we define various classes of rectangular groups such that there is an exponent taken from a set of pairwise coprime positive integers. An important result is the characterization of the class of all semilattices of particular rectangular groups (taken from the classes defined before) using a set-theoretic minimal set of disjunctions of identities. Additionally we investigate semilattices of groups (so-called Clifford semigroups). For this purpose we consider abelian groups of particular exponents and prove some well-known results from the theory of Clifford semigroups in an alternative way applying the concept of disjunctions of identities. As a practical application of the results concerning semilattices of left zero semigroups and right zero semigroups we identify a particular transformation semigroup. For more detailed information about the product of two arbitrary elements of a semilattice of semigroups we introduce the concept of strong semilattices of semigroups. It is well-known that a semilattice of groups is a strong semilattice of groups. So we can characterize a strong semilattice of groups of particular pairwise coprime exponents by disjunctions of identities. Additionally we describe the class of all strong semilattices of left zero semigroups and right zero semigroups with the help of such kind of identity, and we relate this statement to the theory of normal bands. A possible extension of the already described semilattices of rectangular groups can be achieved by an auxiliary total order (in terms of chains of semigroups). To this end we present a corresponding characterization due to disjunctions of identities which is obviously minimal. A list of open questions which have arisen during the research for this thesis, but left crude, is attached.},
  language  = {en}
}
@phdthesis{Radloff2018,
  author    = {Radloff, Katrin},
  title     = {The role of the fatty acid profile and its modulation by cytokines in the systemic inflammation in cancer cachexia},
  school      = {Universit{\"a}t Potsdam},
  pages     = {156},
  year      = {2018},
  abstract  = {Systemic inflammation is a hallmark of cancer cachexia. Among tumor-host interactions, the white adipose tissue (WAT) is an important contributor to inflammation as it suffers morphological reorganization and lipolysis, releasing free fatty acids (FA), bioactive lipid mediators (LM) and pro-inflammatory cytokines, which accentuate the activation of pro-inflammatory signaling pathways and the recruitment of immune cells to the tissue. This project aimed to investigate which inflammatory factors are involved in the local adipose tissue inflammation and what is the influence of such factors upon enzymes involved in FA or LM metabolism in healthy individuals (Control), weight stable gastro-intestinal cancer patients (WSC) and cachectic cancer patients (CC). The results demonstrated that the inflammatory signature of systemic inflammation is different from local adipose tissue inflammation. The systemic inflammation of the cachectic cancer patients was characterized by higher levels of circulating saturated fatty acids (SFA), tumor-necrosis-factor-α (TNF-α), interleukins IL-6, IL-8 and CRP while levels of polyunsaturated fatty acids (PUFAs), especially n3-PUFAs, were lower in CC than in the other groups. In vitro and in adipose tissue explants, pro-inflammatory cytokines and SFAs were shown to increase the chemokines IL-8 and CXCL10 that were found to be augmented in adipose tissue inflammation in CC which was more profound in the visceral adipose tissue (VAT) than in subcutaneous adipose tissue (SAT). Systemic inflammation was negatively associated with the expression of PUFA synthesizing enzymes, though gene and protein expression did hardly differ between groups. The effects of inflammatory factors on enzymes in the whole tissue could have been masked by differentiated modulation of the diverse cell types in the same tissue. In vitro experiments showed that the expression of FA-modifying enzymes such as desaturases and elongases in adipocytes and macrophages was regulated into opposing directions by TNF-α, IL-6, LPS or palmitate. The higher plasma concentration of the pro-resolving LM resolvin D1 in CC cannot compensate the overall inflammatory status and the results indicate that inflammatory cytokines interfere with synthesis pathways of pro-resolving LM. In summary, the data revealed a complex inter-tissue and inter-cellular crosstalk mediated by pro-inflammatory cytokines and lipid compounds enhancing inflammation in cancer cachexia by feed-forward mechanisms.},
  language  = {en}
}
@phdthesis{Radloff2018,
  author    = {Radloff, Katrin},
  title     = {The role of the fatty acid profile and its modulation by cytokines in the systemic inflammation in cancer cachexia},
  school      = {Universit{\"a}t Potsdam},
  pages     = {156},
  year      = {2018},
  language  = {en}
}
@phdthesis{Harutyunyan2018,
  author    = {Harutyunyan, Gohar},
  title     = {Spectroscopy at the limit},
  pages     = {X, 112},
  year      = {2018},
  language  = {en}
}
@phdthesis{Mott2018,
  author    = {Mott, Alessandro},
  title     = {Analysis of the lithium resonance doublet in cool stars with 3D model atmospheres and NLTE line formation},
  pages     = {X, 148},
  year      = {2018},
  language  = {en}
}
@phdthesis{Stoessel2018,
  author    = {St{\"o}ßel, Daniel},
  title     = {Biomarker Discovery in Multiple Sclerosis and Parkinson's disease},
  school      = {Universit{\"a}t Potsdam},
  pages     = {135},
  year      = {2018},
  abstract  = {Neuroinflammatory and neurodegenerative diseases such as Parkinson's (PD) and multiple sclerosis (MS) often result in a severe impairment of the patient´s quality of life. Effective therapies for the treatment are currently not available, which results in a high socio-economic burden. Due to the heterogeneity of the disease subtypes, stratification is particularly difficult in the early phase of the disease and is mainly based on clinical parameters such as neurophysiological tests and central nervous imaging. Due to good accessibility and stability, blood and cerebrospinal fluid metabolite markers could serve as surrogates for neurodegenerative processes. This can lead to an improved mechanistic understanding of these diseases and further be used as "treatment response" biomarkers in preclinical and clinical development programs. Therefore, plasma and CSF metabolite profiles will be identified that allow differentiation of PD from healthy controls, association of PD with dementia (PDD) and differentiation of PD subtypes such as akinetic rigid and tremor dominant PD patients. In addition, plasma metabolites for the diagnosis of primary progressive MS (PPMS) should be investigated and tested for their specificity to relapsing-remitting MS (RRMS) and their development during PPMS progression. By applying untargeted high-resolution metabolomics of PD patient samples and in using random forest and partial least square machine learning algorithms, this study identified 20 plasma metabolites and 14 CSF metabolite biomarkers. These differentiate against healthy individuals with an AUC of 0.8 and 0.9 in PD, respectively. We also identify ten PDD specific serum metabolites, which differentiate against healthy individuals and PD patients without dementia with an AUC of 1.0, respectively. Furthermore, 23 akinetic-rigid specific plasma markers were identified, which differentiate against tremor-dominant PD patients with an AUC of 0.94 and against healthy individuals with an AUC of 0.98. These findings also suggest more severe disease pathology in the akinetic-rigid PD than in tremor dominant PD. In the analysis of MS patient samples a partial least square analysis yielded predictive models for the classification of PPMS and resulted in 20 PPMS specific metabolites. In another MS study unknown changes in human metabolism were identified after administration of the multiple sclerosis drug dimethylfumarate, which is used for the treatment of RRMS. These results allow to describe and understand the hitherto completely unknown mechanism of action of this new drug and to use these findings for the further development of new drugs and targets against RRMS. In conclusion, these results have the potential for improved diagnosis of these diseases and improvement of mechanistic understandings, as multiple deregulated pathways were identified. Moreover, novel Dimethylfumarate targets can be used to aid drug development and treatment efficiency. Overall, metabolite profiling in combination with machine learning identified as a promising approach for biomarker discovery and mode of action elucidation.},
  language  = {en}
}
@phdthesis{Eickelmann2018,
  author    = {Eickelmann, Stephan Felix},
  title     = {Experimental Study of Liquid Interfaces with Compositional Gradients},
  doi       = {10.17617/2.3010222},
  school      = {Universit{\"a}t Potsdam},
  pages     = {153},
  year      = {2018},
  abstract  = {Der Inhalt dieser Arbeit ist die experimentelle Untersuchung von verdunstenen d{\"u}nnen Filmen auf glatten Oberfl{\"a}chen, und die Anreicherung, das Kristallwachstum so wie Marangoni-Fluss in der N{\"a}he der Dreiphasenlinie bei partiell benetzenden Mischungen aus fl{\"u}chtigen und nichtfl{\"u}chtigen Fl{\"u}ssigkeiten. Im Detail werden die Eigenschaften von planaren Fl{\"u}ssigkeitsfilmen und d{\"u}nnen Fl{\"u}ssigkeitsabschnitten in der N{\"a}he der dreiphasigen Kontaktlinie behandelt. In beiden F{\"a}llen verliert die Fl{\"u}ssigkeit kontinuierlich eine Komponente durch Verdampfung. Ein Thema ist das ntnetzungsveralten ultrad{\"u}nner Filme aus bin{\"a}ren Mischungen eines fl{\"u}chtigen L{\"o}sungsmittels und eines nichtfl{\"u}chtigen Stoffes. Dabei wird analysiert wie die Dicke, bei der der Film reißt, mit der Kristallisation des gel{\"o}sten Stoffes an der Grenzfl{\"a}che zwischen Fl{\"u}ssigkeit und Substrat in Verbindung steht, sobald der gel{\"o}ste Stoff seine {\"U}bers{\"a}ttigung erreicht. Die Resultate dieses Projektes zeigen eine universelle Beziehung zwischen der Entnetzungdicke und dem S{\"a}ttigungsverhalten. Das zweite Forschungsgebiet sind einzelne Nanopartikel, die in molekular d{\"u}nne Filme auf planaren Substraten eingebettet sind. Es zeigt sich, dass die Nanopartikel eine unerwartet große Filmoberfl{\"a}chenverzerrung (Meniskus) verursachen. Diese Verzerrung kann durch herk{\"o}mmliche Reflexionsmikroskopie quantitativ gemessen werden, obwohl die Nanopartikel viel kleiner als die Rayleigh-Beugungsgrenze sind. Untersuchungen mit bin{\"a}ren Mischungen fl{\"u}chtiger L{\"o}sungsmittel und nichtfl{\"u}chtiger Stoffe (Polymere) zielen auf ein besseres Verst{\"a}ndnis/Vorhersage der finalen Schichtdicke, zeitaufgel{\"o}sten Verd{\"u}nnung, zeitaufgel{\"o}sten Verdunstung und der Entwicklung der Konzentration des gel{\"o}sten Stoffes innerhalb des verd{\"u}nnenden Filmes. Eine quantitative theoretische Beschreibung der experimentellen Ergebnisse wird hergeleitet. Unerwarteterweise zeigen die Experimente, mit vollst{\"a}ndig mischbarer bin{\"a}rer Mischungen fl{\"u}chtiger Fl{\"u}ssigkeiten, die einzeln glatte Filme bilden, dass Filme dieser Mischungen nicht notwendigerweise kontinuierlich und glatt sind. Vielmehr k{\"o}nnen sie Oberfl{\"a}chenwellen bilden oder sogar aufreißen. Dies wird mit Oberfl{\"a}chen-Marangoni-Str{\"o}mungen erkl{\"a}rt. Es wird eine neue Methode f{\"u}r die schnelle Herstellung von ultralang gerichtetn Diphenylalanin-Einkristallen (Dip- Casting) (mm/min) vorgestellt. Dabei viii wird gezeigt, wie die spezifischen Verdunstungsbedingen an der Dreiphasenlinie f{\"u}r einen kontrollierten Peptidkristallwachstumsprozess verwendet werden k{\"o}nnen. Abschließend wird gezeigt, wie die Beschr{\"a}nkung innerhalb einer kleinen Kapillare die Peptidkristallisation beeinflusst, diese verstanden und verwendet werden kann.},
  language  = {en}
}
@phdthesis{Hasan2018,
  author    = {Hasan, Ahmed Abdallah Abdalrahman Mohamed},
  title     = {GLP-1 receptor-independent mechanisms of DPP-4 inhibition on renal disease progression},
  school      = {Universit{\"a}t Potsdam},
  pages     = {113},
  year      = {2018},
  language  = {en}
}
@phdthesis{Schimka2018,
  author    = {Schimka, Selina},
  title     = {Photoresponsive soft nano-objects},
  school      = {Universit{\"a}t Potsdam},
  pages     = {135},
  year      = {2018},
  language  = {en}
}
@phdthesis{Totz2018,
  author    = {Totz, Sonja Juliana},
  title     = {Modeling and data analysis of large-scale atmosphere dynamics associated with extreme weather},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xii, 166},
  year      = {2018},
  abstract  = {In the last decades the frequency and intensity of extreme weather events like heat waves and heavy rainfall have increased and are at least partly linked to global warming. These events can have a strong impact on agricultural and economic production and, thereby, on society. Thus, it is important to improve our understanding of the physical processes leading to those extreme events in order to provide accurate near-term and long-term forecasts. Thermodynamic drivers associated with global warming are well understood, but dynamical aspects of the atmosphere much less so. The dynamical aspects, while less important than the thermodynamic drivers in regards to large-scale and long-time averaged effects, play a critical role in the formation of extremes. The overall aim of this thesis is to improve our understanding of patterns, variability and trends in the global atmospheric circulation under a changing climate. In particular, in this dissertation I developed two new data-driven methods to quantitatively describe the dynamics of jet streams, Hadley cells and storm tracks. In addition, I introduce and validate a new statistical-dynamical atmosphere model that can be used to efficiently model the large-scale circulation. First, I developed a scheme based on the Dijkstra 'shortest-path' algorithm to identify jet stream cores. Using reanalysis data, I found a significant change in jet stream strength and position over the last decades: Specifically, a decrease in wind speeds and a spatial shift toward the poles. This work also shows that the splitting or merging of the polar front jet stream and the subtropical jet stream depends on the season and longitudinal position. In a follow-up study, I analyzed trends in the latitudinal position of the poleward edge of the Hadley cell and subtropical jet stream core for all longitudes. These trends depend strongly on longitude and thus the impacts of tropical expansion might be pronounced in some regions and absent in others. The second approach was to develop an empirical forecast method for European and Mediterranean winter precipitation. This prediction algorithm innovatively incorporates the spatial patterns of predictors in autumn using clustering analyses. I identified the most important precursors (snow cover in Eurasia, Barents and Kara sea ice concentrations as well as sea surface temperature in the Atlantic and Mediterranean region) for the precipitation prediction. This forecast algorithm had higher forecast skills than conventionally employed methods such as Canonical Correlation Analysis or operational systems using climate models. The last approach was to examine the atmospheric circulation using the novel statisticaldynamical atmosphere model Aeolus. First, I validated the model's depiction of the largescale circulation in terms of Hadley circulation, jet streams, storm tracks and planetary waves. To do so, I performed a parameter optimization using simulated annealing. Next, I investigated the sensitivity of the large-scale circulation to three different temperature components: global mean temperature, meridional temperature gradient and zonal temperature gradient. The model experiment showed that the strength of the Hadley cell, storm tracks and jet streams depend almost linearly on both the global mean temperature and the meridional temperature gradient, whereas the zonal temperature gradient is shown to have little or no influence. The magnitude of planetary waves is clearly affected by all three temperature components. Finally, the width of the Hadley cell behaves nonlinearly with respect to all three temperature components. These findings might have profound consequences for climate modeling of the Mediterranean region. The latitudinal poleward trend of the Hadley cell edge position might become stronger under climate change according to the results with Aeolus. These changes would lead to a substantial reduction of the winter precipitation in the Mediterranean region. In this case seasonal empirical forecast methods, like the clustering-based prediction scheme, will play an important role for forecasting seasonal droughts in advance such that water managers and politicians can mitigate impacts.},
  language  = {en}
}
@phdthesis{Mubeen2018,
  author    = {Mubeen, Umarah},
  title     = {Regulation of central carbon and nitrogen metabolism by Target of Rapamycin (TOR) kinase in Chlamydomonas reinhardtii},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vii, 153},
  year      = {2018},
  abstract  = {The highly conserved protein complex containing the Target of Rapamycin (TOR) kinase is known to integrate intra- and extra-cellular stimuli controlling nutrient allocation and cellular growth. This thesis describes three studies aimed to understand how TOR signaling pathway influences carbon and nitrogen metabolism in Chlamydomonas reinhardtii. The first study presents a time-resolved analysis of the molecular and physiological features across the diurnal cycle. The inhibition of TOR leads to 50\% reduction in growth followed by nonlinear delays in the cell cycle progression. The metabolomics analysis showed that the growth repression is mainly driven by differential carbon partitioning between anabolic and catabolic processes. Furthermore, the high accumulation of nitrogen-containing compounds indicated that TOR kinase controls the carbon to nitrogen balance of the cell, which is responsible for biomass accumulation, growth and cell cycle progression. In the second study the cause of the high accumulation of amino acids is explained. For this purpose, the effect of TOR inhibition on Chlamydomonas was examined under different growth regimes using stable 13C- and 15N-isotope labeling. The data clearly showed that an increased nitrogen uptake is induced within minutes after the inhibition of TOR. Interestingly, this increased N-influx is accompanied by increased activities of nitrogen assimilating enzymes. Accordingly, it was concluded that TOR inhibition induces de-novo amino acid synthesis in Chlamydomonas. The recognition of this novel process opened an array of questions regarding potential links between central metabolism and TOR signaling. Therefore a detailed phosphoproteomics study was conducted to identify the potential substrates of TOR pathway regulating central metabolism. Interestingly, some of the key enzymes involved in carbon metabolism as well as amino acid synthesis exhibited significant changes in the phosphosite intensities immediately after TOR inhibition. Altogether, these studies provide a) detailed insights to metabolic response of Chlamydomonas to TOR inhibition, b) identification of a novel process causing rapid upshifts in amino acid levels upon TOR inhibition and c) finally highlight potential targets of TOR signaling regulating changes in central metabolism. Further biochemical and molecular investigations could confirm these observations and advance the understanding of growth signaling in microalgae.},
  language  = {en}
}
@phdthesis{Bolius2018,
  author    = {Bolius, Sarah},
  title     = {Microbial invasions in aquatic systems - strain identity, genetic diversity and timing},
  school      = {Universit{\"a}t Potsdam},
  pages     = {154},
  year      = {2018},
  abstract  = {Biological invasions are the dispersal and following establishment of species outside their native habitat. Due to globalisation, connectivity of regions and climate changes the number of invasive species and their successful establishment is rising. The impact of these species is mostly negative, can induce community and habitat alterations, and is one main cause for biodiversity loss. This impact is particularly high and less researched in aquatic systems and microbial organisms and despite the high impact, the knowledge about overall mechanisms and specific factors affecting invasions are not fully understood. In general, the characteristics of the habitat, native community and invader determine the invasiveness. In this thesis, I aimed to provide a better understanding of aquatic invasions focusing on the invader and its traits and identity. This thesis used a set of 12 strains of the invasive cyanobacterium <i>Cylindrospermopsis raciborskii</i> to examine the effect and impact of the invaders' identity and genetic diversity. Further, the effect of timing on the invasion potential and success was determined, because aquatic systems in particular undergo seasonal fluctuations. Most studies revealed a higher invasion success with increasing genetic diversity. Here, the increase of the genetic diversity, by either strain richness or phylogenetic dissimilarity, is not firstly driving the invasion, but the strain-identity. The high variability among the strains in traits important for invasions led to the highly varying strain-specific invasion success. This success was most dependent on nitrogen uptake and efficient resource use. The lower invasion success into communities comprising further N-fixing species indicates <i>C. raciborskii</i> can use this advantage only without the presence of competitive species. The relief of grazing pressure, which is suggested to be more important in aquatic invasions, was only promoting the invasion when unselective and larger consumers were present. High abundances of unselective consumers hampered the invasion success. This indicates a more complex and temporal interplay of competitive and consumptive resistance mechanisms during the invasion process. Further, the fluctuation abundance and presence of competitors (= primary producers) and consumers (= zooplankton) in lakes can open certain 'invasion windows'. Remarkably, the composition of the resident community was also strain-specific affected and altered, independent of a high or low invasion success. Prior, this was only documented on the species level. Further, investigations on the population of invasive strains can reveal more about the invasion patterns and how multiple strain invasions change resident communities. The present dissertation emphasises the importance of invader-addition experiments with a community context and the importance of the strain-level for microbial invasions and in general, e.g. for community assemblies and the outcome of experiments. The strain-specific community changes, also after days, may explain some sudden changes in communities, which have not been explained yet. This and further knowledge may also facilitate earlier and less cost-intensive management to step in, because these species are rarely tracked until they reach a high abundance or bloom, because of their small size. Concluded for <i>C. raciborskii</i>, it shows that this species is no 'generalistic' invader and its invasion success depends more on the competitor presence than grazing pressure. This may explain its, still unknown, invasion pattern, as <i>C. raciborskii</i> is not found in all lakes of a region.},
  language  = {en}
}
@phdthesis{Herzberg2018,
  author    = {Herzberg, Nico},
  title     = {Integrating events into non-automated business process environments},
  school      = {Universit{\"a}t Potsdam},
  pages     = {243},
  year      = {2018},
  language  = {en}
}
@phdthesis{Agrawal2018,
  author    = {Agrawal, Shreya},
  title     = {Engineering the isoprenoid pathway for molecular farming and effect of tRNA(Glu) manipulation on tetrapyrrole biosynthesis},
  school      = {Universit{\"a}t Potsdam},
  pages     = {viii, 131},
  year      = {2018},
  language  = {en}
}
@phdthesis{Darmawan2018,
  author    = {Darmawan, Herlan},
  title     = {Morphometric changes at the Merapi lava dome between 2012 and 2017},
  school      = {Universit{\"a}t Potsdam},
  pages     = {134},
  year      = {2018},
  language  = {en}
}
@phdthesis{Ma2018,
  author    = {Ma, Xuemin},
  title     = {Characterization of NAC transcription factors involved in leaf senescence and fruit ripening in tomato},
  school      = {Universit{\"a}t Potsdam},
  pages     = {134},
  year      = {2018},
  language  = {en}
}
@phdthesis{Reese2018,
  author    = {Reese, Ronja},
  title     = {The far reach of ice-shelf thinning in Antarctica},
  school      = {Universit{\"a}t Potsdam},
  pages     = {227},
  year      = {2018},
  language  = {en}
}
@phdthesis{Schoene2018,
  author    = {Sch{\"o}ne, Anne-Christin},
  title     = {Degradation of Aliphatic Polyesters at the Air-Water Interface - Capabilities of the Langmuir Monolayer Technique},
  school      = {Universit{\"a}t Potsdam},
  pages     = {109, XXXIX},
  year      = {2018},
  language  = {en}
}
@phdthesis{Schwarzer2018,
  author    = {Schwarzer, Christian},
  title     = {Climate change, adaptive divergence and their effects on species interactions in European bog-plant communities},
  school      = {Universit{\"a}t Potsdam},
  pages     = {169},
  year      = {2018},
  language  = {en}
}
@phdthesis{Hilgers2018,
  author    = {Hilgers, Leon},
  title     = {From innovation to diversification},
  school      = {Universit{\"a}t Potsdam},
  pages     = {130},
  year      = {2018},
  language  = {en}
}
@phdthesis{Gruetze2018,
  author    = {Gr{\"u}tze, Toni},
  title     = {Adding value to text with user-generated content},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ii, 114},
  year      = {2018},
  abstract  = {In recent years, the ever-growing amount of documents on the Web as well as in closed systems for private or business contexts led to a considerable increase of valuable textual information about topics, events, and entities. It is a truism that the majority of information (i.e., business-relevant data) is only available in unstructured textual form. The text mining research field comprises various practice areas that have the common goal of harvesting high-quality information from textual data. These information help addressing users' information needs. In this thesis, we utilize the knowledge represented in user-generated content (UGC) originating from various social media services to improve text mining results. These social media platforms provide a plethora of information with varying focuses. In many cases, an essential feature of such platforms is to share relevant content with a peer group. Thus, the data exchanged in these communities tend to be focused on the interests of the user base. The popularity of social media services is growing continuously and the inherent knowledge is available to be utilized. We show that this knowledge can be used for three different tasks. Initially, we demonstrate that when searching persons with ambiguous names, the information from Wikipedia can be bootstrapped to group web search results according to the individuals occurring in the documents. We introduce two models and different means to handle persons missing in the UGC source. We show that the proposed approaches outperform traditional algorithms for search result clustering. Secondly, we discuss how the categorization of texts according to continuously changing community-generated folksonomies helps users to identify new information related to their interests. We specifically target temporal changes in the UGC and show how they influence the quality of different tag recommendation approaches. Finally, we introduce an algorithm to attempt the entity linking problem, a necessity for harvesting entity knowledge from large text collections. The goal is the linkage of mentions within the documents with their real-world entities. A major focus lies on the efficient derivation of coherent links. For each of the contributions, we provide a wide range of experiments on various text corpora as well as different sources of UGC. The evaluation shows the added value that the usage of these sources provides and confirms the appropriateness of leveraging user-generated content to serve different information needs.},
  language  = {en}
}
@phdthesis{Weiss2018,
  author    = {Weiß, Stefanie},
  title     = {Contribution of bacterially synthesized folate vitamers to folate status and impact on crohn's Disease},
  school      = {Universit{\"a}t Potsdam},
  pages     = {148},
  year      = {2018},
  language  = {en}
}
@phdthesis{Pham2018,
  author    = {Pham, Phuong Anh},
  title     = {The metabolic significance of the NAD+ salvage pathway and the alternative pathway of respiration in Arabidopsis thaliana},
  school      = {Universit{\"a}t Potsdam},
  pages     = {186},
  year      = {2018},
  language  = {en}
}
@phdthesis{Warner2018,
  author    = {Warner, Greta J.},
  title     = {Personal initiative in childhood and early adolescence},
  school      = {Universit{\"a}t Potsdam},
  pages     = {235},
  year      = {2018},
  language  = {en}
}
@phdthesis{Brell2018,
  author    = {Brell, Maximilian},
  title     = {Physically based fusion of airborne hyperspectral and lidar data},
  school      = {Universit{\"a}t Potsdam},
  pages     = {112},
  year      = {2018},
  language  = {en}
}
@phdthesis{Heinecke2018,
  author    = {Heinecke, Liv},
  title     = {Environmental change in the Eastern Pamir Mountains during last 28 cal ka BP},
  school      = {Universit{\"a}t Potsdam},
  pages     = {139},
  year      = {2018},
  language  = {en}
}
@phdthesis{Remuss2018,
  author    = {Remuß, Nina-Louisa},
  title     = {Theorising Institutional Change},
  school      = {Universit{\"a}t Potsdam},
  pages     = {231},
  year      = {2018},
  language  = {en}
}
@phdthesis{Gaus2018,
  author    = {Gaus, Alexander},
  title     = {Politics at the international competition network},
  school      = {Universit{\"a}t Potsdam},
  pages     = {X, 260},
  year      = {2018},
  language  = {en}
}
@phdthesis{Chen2018,
  author    = {Chen, Guoxiang},
  title     = {Nanoparticles at solid interfaces},
  school      = {Universit{\"a}t Potsdam},
  pages     = {112},
  year      = {2018},
  abstract  = {Nanoparticles (NPs) are particles between 1 and 100 nanometers in size. They have attracted enormous research interests owing to their remarkable physicochemical properties and potential applications in the optics, catalysis, sensing, electronics, or optical devices. The thesis investigates systems of NPs attached to planar substrates. In the first part of the results section of the thesis a new method is presented to immobilize NPs. In many NP applications a strong, persistent adhesion to substrates is a key requirement. Up to now this has been achieved with various methods, which are not always the optimum regarding adhesion strength or applicability. We propose a new method which uses capillarity to enhance the binding agents in the contact area between NP and substrate. The adhesion strength resulting from the new approach is investigated in detail and it is shown that the new approach is superior to older methods in several ways. The following section presents the optical visualization of nano-sized objects through a combination of thin film surface distortion and interference enhanced optical reflection microscopy. It is a new, fast and non-destructive technique. It not only reveals the location of NPs as small as 20nm attached to planar surfaces and embedded in a molecularly thin liquid film. It also allows the measurement of the geometry of the surface distortion of the liquid film. Even for small NPs the meniscus reaches out for micrometers, which is the reason why the NPs produce such a pronounced optical footprint. The nucleation and growth of individual bubbles is presented in chapter 5. Nucleation is a ubiquitous natural phenomenon and of great importance in numerous industrial processes. Typically it occurs on very small scales (nanometers) and it is of a random nature (thermodynamics of small systems). Up to now most experimental nucleation studies deal with a large number of individual nucleation processes to cope with its inherently statistical, spatio-temporal character. In contrast, in this thesis the individual O2-bubble formation from single localized platinum NP active site is studied experimentally. The bubble formation is initiated by the catalytic reaction of H2O2 on the Pt surface. It is studied how the bubble nucleation and growth depends on the NP size, the H2O2 concentration and the substrate surface properties. It is observed that in some cases the bubbles move laterally over the substrate surface, driven by the O2-production and the film ablation.},
  language  = {en}
}
@phdthesis{Mueller2018,
  author    = {M{\"u}ller, Sandra Marie},
  title     = {Food-relevant arsenic species},
  school      = {Universit{\"a}t Potsdam},
  pages     = {163, Viii},
  year      = {2018},
  language  = {en}
}
@phdthesis{AlFadel2018,
  author    = {Al Fadel, Frdoos},
  title     = {Influence of sphingosine 1-phosphate and its receptor modulators on the development of liver fibrosis},
  school      = {Universit{\"a}t Potsdam},
  pages     = {156},
  year      = {2018},
  language  = {en}
}
@phdthesis{Zhang2018,
  author    = {Zhang, Quanchao},
  title     = {Shape-memory properties of polymeric micro-scale objects prepared by electrospinning and electrospraying},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvi, 53},
  year      = {2018},
  abstract  = {The ongoing trend of miniaturizing multifunctional devices, especially for minimally-invasive medical or sensor applications demands new strategies for designing the required functional polymeric micro-components or micro-devices. Here, polymers, which are capable of active movement, when an external stimulus is applied (e.g. shape-memory polymers), are intensively discussed as promising material candidates for realization of multifunctional micro-components. In this context further research activities are needed to gain a better knowledge about the underlying working principles for functionalization of polymeric micro-scale objects with a shape-memory effect. First reports about electrospun solid microfiber scaffolds, demonstrated a much more pronounced shape-memory effect than their bulk counterparts, indicating the high potential of electrospun micro-objects. Based on these initial findings this thesis was aimed at exploring whether the alteration of the geometry of micro-scale electrospun polymeric objects can serve as suitable parameter to tailor their shape-memory properties. The central hypothesis was that different geometries should result in different degrees of macromolecular chain orientation in the polymeric micro-scale objects, which will influence their mechanical properties as well as thermally-induced shape-memory function. As electrospun micro-scale objects, microfiber scaffolds composed of hollow microfibers with different wall thickness and electrosprayed microparticles as well as their magneto-sensitive nanocomposites all prepared from the same polymer exhibiting pronounced bulk shape-memory properties were investigated. For this work a thermoplastic multiblock copolymer, named PDC, with excellent bulk shape-memory properties, associated with crystallizable oligo(ε-caprolactone) (OCL) switching domains, was chosen for the preparation of electrospun micro-scale objects, while crystallizable oligo(p-dioxanone) (OPDO) segments serve as hard domains in PDC. In the first part of the thesis microfiber scaffolds with different microfiber geometries (solid or hollow with different wall thickness) were discussed. Hollow microfiber based PDC scaffolds were prepared by coaxial electrospinning from a 1, 1, 1, 3, 3, 3 hexafluoro-2-propanol (HFP) solution with a polymer concentration of 13\% w·v-1. Here as a first step core-shell fiber scaffolds consisting of microfibers with a PDC shell and sacrificial poly(ethylene glycol) (PEG) core are generated. The hollow PDC microfibers were achieved after dissolving the PEG core with water. The utilization of a fixed electrospinning setup and the same polymer concentration of the PDC spinning solution could ensure the fabrication of microfibers with almost identical outer diameters of 1.4 ± 0.3 µm as determined by scanning electron microscopy (SEM). Different hollow microfiber wall thicknesses of 0.5 ± 0.2 and 0.3 ± 0.2 µm (analyzed by SEM) have been realized by variation of the mass flow rate, while solid microfibers were obtained by coaxial electrospinning without supplying any core solution. Differential scanning calorimetry experiments and tensile tests at ambient temperature revealed an increase in degree of OCL crystallinity form χc,OCL = 34 ± 1\% to 43 ± 1\% and a decrease in elongation of break from 800 ± 40\% to 200 ± 50\% associated with an increase in Young´s modulus and failture stress for PDC hollow microfiber scaffolds when compared with soild fibers. The observed effects were enhanced with decreasing wall thickness of the single hollow fibers. The shape-memory properties of the electrospun PDC scaffolds were quantified by cyclic, thermomechanical tensile tests. Here, scaffolds comprising hollow microfibers exhibited lower shape fixity ratios around Rf = 82 ± 1\% and higher shape recovery ratios of Rr = 67 ± 1\% associated to more pronounced relaxation at constant strain during the first test cycle and a lower switching temperature of Tsw = 33 ± 1 °C than the fibrous meshes consisting of solid microfibers. These findings strongly support the central hypothesis that different fiber geometries (solid or hollow with different wall thickness) in electrospun scaffolds result in different degrees of macromolecular chain orientation in the polymeric micro-scale objects, which can be applied as design parameter for tailoring their mechanical and shape-memory properties. The second part of the thesis deals with electrosprayed particulate PDC micro-scale objects. Almost spherical PDC microparticles with diameters of 3.9 ± 0.9 μm (as determined by SEM) were achieved by electrospraying of HFP solution with a polymer concentration of 2\% w·v-1. In contrast, smaller particles with sizes of 400 ± 100 nm or 1.2 ± 0.3 μm were obtained for the magneto-sensitive composite PDC microparticles containing 23 ± 0.5 wt\% superparamagnetic magnetite nanoparticles (mNPs). All prepared PDC microparticles exhibited a similar overall crystallinity like the PDC bulk material as analyzed by DSC. AFM nanoindentation results revealed no influence of the nanofiller incorporation on the local mechanical properties represented by the reduced modulus determined for pure PDC microparticles and magneto-sensitive composite PDC microparticles with similar diameters around 1.3 µm. It was found that the reduced modulus of the nanocomposite microparticles increased substantially with decreasing particles size from 2.4 ± 0.9 GPa (1.2 µm) to 11.9 ± 3.1 GPa (0.4 µm), which can be related to a higher orientation of the macromolecules at the surface of smaller sized microparticles. The magneto-sensitivity of such nanocomposite microparticles could be demonstrated in two aspects. One was by attracting/collecting the composite micro-objects with an external permanent magnet. The other one was by a inductive heating to 44 ± 1 °C, which is well above the melting transition of the OCL switching domains, when compacted to a 10 x 10 mm2 film with a thickness of 10 µm and exposed to an alternating magnet field with an magnetic field strength of 30 kA·m-1. Both functions are of great relevance for designing next generation drug delivery systems combining targeting and on demand release. By a compression approach shape-memory functionalization of individual microparticles could be realized. Here different programming pressures and compression temperatures were applied. The shape-recovery capability of the programmed PDC microparticles was quantified by online and off-line heating experiments analyzed via microscopy measurement. The obtained shape-memory properties were found to be strongly depending on the applied programming pressure and temperature. The best shape-memory performance with a high shape recovery rate of about Rr = 80±1\% was obtained when a low pressure of 0.2 MPa was applied at 55 °C. Finally, it was demonstrated that PDC microparticles can be utilized as micro building parts for preparation of a macroscopic film with temporary stability by compression of a densely packed array of PDC microparticles at 60 °C followed by subsequent cooling to ambient temperature. This film disintegrates into individual microparticles upon heating to 60 °C. Based on this technology the design of stable macroscopic release systems can be envisioned, which can be easily fixed at the site of treatment (i.e. by suturing) and disintegrate on demand to microparticles facilitating the drug release. In summary, the results of this thesis could confirm the central hypothesis that the variation of the geometry of polymeric micro-objects is a suitable parameter to adjust their shape-memory performance by changing the degree of macromolecular chain orientation in the specimens or by enabling new functions like on demand disintegration. These fundamental findings might be relevant for designing novel miniaturized multifunctional polymer-based devices.},
  language  = {en}
}
@phdthesis{Wang2018,
  author    = {Wang, Li},
  title     = {Reprogrammable, magnetically controlled polymer actuators},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxviii, 107},
  year      = {2018},
  abstract  = {Polymeric materials, which can perform reversible shape changes after programming, in response to a thermal or electrical stimulation, can serve as (soft) actuating components in devices like artificial muscles, photonics, robotics or sensors. Such polymeric actuators can be realized with hydrogels, liquid crystalline elastomers, electro-active polymers or shape-memory polymers by controlling with stumuli such as heat, light, electrostatic or magnetic field. If the application conditions do not allow the direct heating or electric stimulation of these smart devices, noncontact triggering will be required. Remotely controlled actuation have been reported for liquid crystalline elastomer composites or shape-memory polymer network composites, when a persistent external stress is applied during inductive heating in an alternating magnetic field. However such composites cannot meet the demands of applications requiring remotely controlled free-standing motions of the actuating components. The current thesis investigates, whether a reprogrammable remotely controlled soft actuator can be realized by magneto-sensitive multiphase shape-memory copolymer network composites containing magnetite nanoparticles as magneto-sensitive multivalent netpoints. A central hypothesis was that a magnetically controlled two-way (reversible bidirectional) shape-memory effect in such nanocomposites can be achieved without application of external stress (freestanding), when the required orientation of the crystallizable actuation domains (ADs) can be ensured by an internal skeleton like structure formed by a second crystallizable phase determing the samples´s geometry, while magneto-sensitive iron oxide nanoparticles covalently integrated in the ADs allow remote temperature control. The polymer matrix of these composites should exhibit a phase-segregated morphology mainly composed of cyrstallizable ADs, whereby a second set of higher melting crystallites can take a skeleton like, geometry determining function (geometry determining domains, GDs) after programming of the composite and in this way the orientation of the ADs is established and maintained during actuation. The working principle for the reversible bidirectional movements in the multiphase shape-memory polymer network composite is related to a melting-induced contraction (MIC) during inductive heating and the crystallization induced elongation (CIE) of the oriented ADs during cooling. Finally, the amount of multivalent magnetosensitive netpoints in such a material should be as low as possible to ensure an adequate overall elasticity of the nanocomposite and at the same time a complete melting of both ADs and GDs via inductive heating, which is mandatory for enabling reprogrammability. At first, surface decorated iron oxide nanoparticles were synthesized and investigated. The coprecipitation method was applied to synthesize magnetic nanoparticles (mNPs) based on magnetite with size of 12±3 nm and in a next step a ring-opening polymerization (ROP) was utilized for covalent surface modification of such mNPs with oligo(ϵ-caprolactone) (OCL) or oligo(ω-pentadecalactone) (OPDL) via the "grafting from" approach. A successful coating of mNPs with OCL and OPDL was confirmed by differential scanning calorimetry (DSC) experiments showing melting peaks at 52±1 °C for mNP-OCL and 89±1 °C for mNP-OPDL. It was further explored whether two-layered surface decorated mNPs, can be prepared via a second surface-initiated ROP of mNP-OCL or mNP-OPDL with ω-pentadecalactone or ϵ-caprolactone. The observation of two distinct melting transitions in DSC experiments as well as the increase in molecular weight of the detached coatings determined by GPC and 1H-NMR indicated a successful synthesis of the twolayered nanoparticles mNP-OCL-OPDL and mNP-OPDL-OCL. In contrast TEM micrographs revealed a reduction of the thickness of the polymeric coating on the nanoparticles after the second ROP, indicating that the applied synthesis and purification required further optimization. For evaluating the impact of the dispersion of mNPs within a polymer matrix on the resulting inductive heating capability of composites, plain mNPs as well as OCL coated magnetite nanoparticles (mNP-OCLs) were physically incorporated into crosslinked poly(ε-caprolactone) (PCL) networks. Inductive heating experiments were performed with both networks cPCL/mNP and cPCL/mNP-OCL in an alternating magnetic field (AMF) with a magnetic field strength of H = 30 kA·m-1. Here a bulk temperature of Tbulk = 74±2 °C was achieved for cPCL/mNP-OCL, which was almost 20 °C higher than the melting transition of the PCL-based polymer matrix. In contrast, the composite with plain mNPs could only reach a Tbulk of 48±2 °C, which is not sufficient for a complete melting of all PCL crystallites as required for actuation. The inductive heating capability of a multiphase copolymer nanocomposite network (designed as soft actuators) containing surface decorated mNPs as covalent netpoints was investigated. Such composite was synthesized from star-shaped OCL and OPDL precursors, as well as mNP-OCLs via reaction with HDI. The weight ratio of OPDL and OCL in the starting reaction mixture was 15/85 (wt\%/wt\%) and the amount of iron oxide in the nanocomposite was 4 wt\%. DSC experiments revealed two well separated melting and crystallization peaks confirming the required phase-segregated morphology in the nanocomposite NC-mNP-OCL. TEM images could illustrate a phase-segregated morphology of the polymer matrix on the microlevel with droplet shaped regions attributed to the OPDL domains dispersed in an OCL matrix. The TEM images could further demonstrate that the nanoparticulate netpoints in NC-mNP-OCL were almost homogeneously dispersed within the OCL domains. The tests of the inductive heating capability of the nanocomposites at a magnetic field strength of Hhigh = 11.2 kA·m-1 revealed a achievable plateau surface temperature of Tsurf = 57±1 °C for NC-mNP-OCL recorded by an infrared video camera. An effective heat generation constant (̅P) can be derived from a multi-scale model for the heat generation, which is proportional to the rate of heat generation per unit volume of the sample. NC-mNP-OCL with homogeneously dispersed mNP-OCLs exhibited a ̅P value of 1.04±0.01 K·s- 1 at Hhigh, while at Hreset = 30.0 kA·m-1 a Tsurf of 88±1 °C (where all OPDL related crystallite are molten) and a ̅P value of 1.93±0.02 K·s-1 was obtained indicating a high magnetic heating capability of the composite. The free-standing magnetically-controlled reversible shape-memory effect (mrSME) was explored with originally straight nanocomposite samples programmed by bending to an angle of 180°. By switching the magnetic field on and off the composite sample was allowed to repetitively heat to 60 °C and cool to the ambient temperature. A pronounced mrSME, characterized by changes in bending angle of Δϐrev = 20±3° could be obtained for a composite sample programmed by bending when a magnetic field strength of Hhigh = 11.2 kA·m-1 was applied in a multi-cyclic magnetic bending experiment with 600 heating-cooling cycles it could be shown that the actuation performance did not change with increasing number of test cycles, demonstrating the accuracy and reproducibility of this soft actuator. The degree of actuation as well as the kinetics of the shape changes during heating could be tuned by variation of the magnetic filed strength between Hlow and Hhigh or the magnetic field exposure time. When Hreset = 30.0 kA·m-1 was applied the programmed geometry was erased and the composite sample returned to it´s originally straight shape. The reprogrammability of the nanocomposite actuators was demonstrated by one and the same test specimen first exhibiting reversible angle changes when programmed by bending, secondly reprogrammed to a concertina, which expands upon inductive heating and contracts during cooling and finally reprogrammed to a clip like shape, which closes during cooling and opens when Hhigh was applied. In a next step the applicability of the presented remote controllable shape-memory polymer actuators was demonstrated by repetitive opening and closing of a multiring device prepared from NC-mNP-OCL, which repetitively opens and closes when a alternating magnetic field (Hhigh = 11.2 kA·m-1) was switched on and off. For investigation of the micro- and nanostructural changes related to the actuation of the developed nanocomposite, AFM and WAXS experiments were conducted with programmed nanocomposite samples under cyclic heating and cooling between 25 °C and 60 °C. In AFM experiments the change in the distance (D) between representative droplet-like structures related to the OPDL geometry determining domains was used to calculate the reversible change in D. Here Drev = 3.5±1\% was found for NC-mNP-OCL which was in good agreement with the results of the magneto-mechanical actuation experiments. Finally, the analysis of azimuthal (radial) WAXS scattering profiles could support the oriented crystallization of the OCL actuation domains at 25 °C. In conclusion, the results of this work successfully demonstrated that shape-memory polymer nanocomposites, containing mNPs as magneto-sensitive multifunctional netpoints in a covalently crosslinked multiphase polymer matrix, exhibit magnetically (remotely) controlled actuations upon repetitive exposure to an alternating magnetic field. Furthermore, the (shape) memory of such a nanocomposite can be erased by exposing it to temperatures above the melting temperature of the geometry forming domains, which allows a reprogramming of the actuator. These findings would be relevant for designing novel reprogrammable remotely controllable soft polymeric actuators.},
  language  = {en}
}
@phdthesis{AbdAllahSalem2018,
  author    = {Abd Allah Salem, Mohamed},
  title     = {Comparative and systemic metabolomic analysis of the model plant Arabidopsis thaliana after perturbing the essential Target of Rapamycin (TOR) pathway},
  school      = {Universit{\"a}t Potsdam},
  pages     = {113},
  year      = {2018},
  language  = {en}
}
@phdthesis{Preuss2018,
  author    = {Preuß, Melanie},
  title     = {New Perspectives on Negotiation Styles},
  series = {Schriftenreihe zum Verhandlungsmanagement},
  journal   = {Schriftenreihe zum Verhandlungsmanagement},
  number    = {7},
  publisher = {Verlag Dr. Kovač},
  address   = {Hamburg},
  isbn      = {978-3-8300-9794-5},
  issn      = {2365-7898},
  pages     = {XI, 110},
  year      = {2018},
  abstract  = {Companies have a keen interest in developing skilled negotiators in order to improve their negotiation outcome. A crucial determinant of the negotiation outcome are negotiation styles that represent the negotiator's actual behavior during the negotiation process. In this context, the author examines the variation in negotiation styles throughout the negotiation process, points out the relevance of the negotiator's characteristics and situational context as determinants of negotiation styles, and emphasizes the importance not only of actual but also of perceived negotiation behavior. As a result, existing negotiation research is advanced as new perspectives on negotiation styles are offered to improve a negotiator's performance.},
  language  = {en}
}
@phdthesis{Robalo2018,
  author    = {Robalo, Jo{\~a}o Ramiro Alavedra Mendes},
  title     = {Investigating the role of fluorinated amino acids on protein structure and function using simulation},
  school      = {Universit{\"a}t Potsdam},
  pages     = {84},
  year      = {2018},
  language  = {en}
}