@phdthesis{ValdiviaOrozco2013, author = {Valdivia Orozco, Pablo Emilio}, title = {Weltenvielfalt ; eine Romantheoretische Studie im Ausgang von Gabriel Garcia Maraquez, Sandra Cisneros und Roberto Bolano}, series = {Mimesis : Romanische Literaturen der Welt}, volume = {56}, journal = {Mimesis : Romanische Literaturen der Welt}, publisher = {de Gruyter}, address = {Berlin}, isbn = {978-3-11-028974-0}, issn = {0178-7489}, pages = {559 S.}, year = {2013}, language = {de} } @phdthesis{Duensing2013, author = {Duensing, Nina}, title = {Transport processes in the arbuscular mycorrhizal symbiosis}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-68210}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {The nutrient exchange between plant and fungus is the key element of the arbuscular mycorrhizal (AM) symbiosis. The fungus improves the plant's uptake of mineral nutrients, mainly phosphate, and water, while the plant provides the fungus with photosynthetically assimilated carbohydrates. Still, the knowledge about the mechanisms of the nutrient exchange between the symbiotic partners is very limited. Therefore, transport processes of both, the plant and the fungal partner, are investigated in this study. In order to enhance the understanding of the molecular basis underlying this tight interaction between the roots of Medicago truncatula and the AM fungus Rhizophagus irregularis, genes involved in transport processes of both symbiotic partners are analysed here. The AM-specific regulation and cell-specific expression of potential transporter genes of M. truncatula that were found to be specifically regulated in arbuscule-containing cells and in non-arbusculated cells of mycorrhizal roots was confirmed. A model for the carbon allocation in mycorrhizal roots is suggested, in which carbohydrates are mobilized in non-arbusculated cells and symplastically provided to the arbuscule-containing cells. New insights into the mechanisms of the carbohydrate allocation were gained by the analysis of hexose/H+ symporter MtHxt1 which is regulated in distinct cells of mycorrhizal roots. Metabolite profiling of leaves and roots of a knock-out mutant, hxt1, showed that it indeed does have an impact on the carbohydrate balance in the course of the symbiosis throughout the whole plant, and on the interaction with the fungal partner. The primary metabolite profile of M. truncatula was shown to be altered significantly in response to mycorrhizal colonization. Additionally, molecular mechanisms determining the progress of the interaction in the fungal partner of the AM symbiosis were investigated. The R. irregularis transcriptome in planta and in extraradical tissues gave new insight into genes that are differentially expressed in these two fungal tissues. Over 3200 fungal transcripts with a significantly altered expression level in laser capture microdissection-collected arbuscules compared to extraradical tissues were identified. Among them, six previously unknown specifically regulated potential transporter genes were found. These are likely to play a role in the nutrient exchange between plant and fungus. While the substrates of three potential MFS transporters are as yet unknown, two potential sugar transporters are might play a role in the carbohydrate flow towards the fungal partner. In summary, this study provides new insights into transport processes between plant and fungus in the course of the AM symbiosis, analysing M. truncatula on the transcript and metabolite level, and provides a dataset of the R. irregularis transcriptome in planta, providing a high amount of new information for future works.}, language = {en} } @phdthesis{Dannehl2013, author = {Dannehl, Claudia}, title = {Fragments of the human antimicrobial LL-37 and their interaction with model membranes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-68144}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {A detailed description of the characteristics of antimicrobial peptides (AMPs) is highly demanded, since the resistance against traditional antibiotics is an emerging problem in medicine. They are part of the innate immune system in every organism, and they are very efficient in the protection against bacteria, viruses, fungi and even cancer cells. Their advantage is that their target is the cell membrane, in contrast to antibiotics which disturb the metabolism of the respective cell type. This allows AMPs to be more active and faster. The lack of an efficient therapy for some cancer types and the evolvement of resistance against existing antitumor agents make AMPs promising in cancer therapy besides being an alternative to traditional antibiotics. The aim of this work was the physical-chemical characterization of two fragments of LL-37, a human antimicrobial peptide from the cathelicidin family. The fragments LL-32 and LL-20 exhibited contrary behavior in biological experiments concerning their activity against bacterial cells, human cells and human cancer cells. LL-32 had even a higher activity than LL-37, while LL-20 had almost no effect. The interaction of the two fragments with model membranes was systematically studied in this work to understand their mode of action. Planar lipid films were mainly applied as model systems in combination with IR-spectroscopy and X-ray scattering methods. Circular Dichroism spectroscopy in bulk systems completed the results. In the first approach, the structure of the peptides was determined in aqueous solution and compared to the structure of the peptides at the air/water interface. In bulk, both peptides are in an unstructured conformation. Adsorbed and confined to at the air-water interface, the peptides differ drastically in their surface activity as well as in the secondary structure. While LL-32 transforms into an α-helix lying flat at the water surface, LL-20 stays partly unstructured. This is in good agreement with the high antimicrobial activity of LL-32. In the second approach, experiments with lipid monolayers as biomimetic models for the cell membrane were performed. It could be shown that the peptides fluidize condensed monolayers of negatively charged DPPG which can be related to the thinning of a bacterial cell membrane. An interaction of the peptides with zwitterionic PCs, as models for mammalian cells, was not clearly observed, even though LL-32 is haemolytic. In the third approach, the lipid monolayers were more adapted to the composition of human erythrocyte membranes by incorporating sphingomyelin (SM) into the PC monolayers. Physical-chemical properties of the lipid films were determined and the influence of the peptides on them was studied. It could be shown that the interaction of the more active LL-32 is strongly increased for heterogeneous lipid films containing both gel and fluid phases, while the interaction of LL-20 with the monolayers was unaffected. The results indicate an interaction of LL-32 with the membrane in a detergent-like way. Additionally, the modelling of the peptide interaction with cancer cells was performed by incorporating some negatively charged lipids into the PC/SM monolayers, but the increased charge had no effect on the interaction of LL-32. It was concluded, that the high anti-cancer activity of the peptide originates from the changed fluidity of cell membrane rather than from the increased surface charge. Furthermore, similarities to the physical-chemical properties of melittin, an AMP from the bee venom, were demonstrated.  }, language = {en} } @phdthesis{Rothe2013, author = {Rothe, Monique}, title = {Response of intestinal Escherichia coli to dietary factors in the mouse intestine}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-66387}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Diet is a major force influencing the intestinal microbiota. This is obvious from drastic changes in microbiota composition after a dietary alteration. Due to the complexity of the commensal microbiota and the high inter-individual variability, little is known about the bacterial response at the cellular level. The objective of this work was to identify mechanisms that enable gut bacteria to adapt to dietary factors. For this purpose, germ-free mice monoassociated with the commensal Escherichia coli K-12 strain MG1655 were fed three different diets over three weeks: a diet rich in starch, a diet rich in non-digestible lactose and a diet rich in casein. Two dimensional gel electrophoresis and electrospray tandem mass spectrometry were applied to identify differentially expressed proteins of E. coli recovered from small intestine and caecum of mice fed the lactose or casein diets in comparison with those of mice fed the starch diet. Selected differentially expressed bacterial proteins were characterised in vitro for their possible roles in bacterial adaptation to the various diets. Proteins belonging to the oxidative stress regulon oxyR such as alkyl hydroperoxide reductase subunit F (AhpF), DNA protection during starvation protein (Dps) and ferric uptake regulatory protein (Fur), which are required for E. coli's oxidative stress response, were upregulated in E. coli of mice fed the lactose-rich diet. Reporter gene analysis revealed that not only oxidative stress but also carbohydrate-induced osmotic stress led to the OxyR-dependent expression of ahpCF and dps. Moreover, the growth of E. coli mutants lacking the ahpCF or oxyR genes was impaired in the presence of non-digestible sucrose. This indicates that some OxyR-dependent proteins are crucial for the adaptation of E. coli to osmotic stress conditions. In addition, the function of two so far poorly characterised E. coli proteins was analysed: 2 deoxy-D gluconate 3 dehydrogenase (KduD) was upregulated in intestinal E. coli of mice fed the lactose-rich diet and this enzyme and 5 keto 4 deoxyuronate isomerase (KduI) were downregulated on the casein-rich diet. Reporter gene analysis identified galacturonate and glucuronate as inducers of the kduD and kduI gene expression. Moreover, KduI was shown to facilitate the breakdown of these hexuronates, which are normally degraded by uronate isomerase (UxaC), altronate oxidoreductase (UxaB), altronate dehydratase (UxaA), mannonate oxidoreductase (UxuB) and mannonate dehydratase (UxuA), whose expression was repressed by osmotic stress. The growth of kduID-deficient E. coli on galacturonate or glucuronate was impaired in the presence of osmotic stress, suggesting KduI and KduD to compensate for the function of the regular hexuronate degrading enzymes under such conditions. This indicates a novel function of KduI and KduD in E. coli's hexuronate metabolism. Promotion of the intracellular formation of hexuronates by lactose connects these in vitro observations with the induction of KduD on the lactose-rich diet. Taken together, this study demonstrates the crucial influence of osmotic stress on the gene expression of E. coli enzymes involved in stress response and metabolic processes. Therefore, the adaptation to diet-induced osmotic stress is a possible key factor for bacterial colonisation of the intestinal environment.}, language = {en} } @phdthesis{Matthes2013, author = {Matthes, Annika}, title = {Die Dehydro-Diels-Alder-Reaktion (DDA-Reaktion) als neue Methode zur Darstellung von Naphthalenophanen}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-65264}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Die Dissertation beschreibt die Herstellung von ringf{\"o}rmigen Verbindungen (Naphthalenophanen) mit Hilfe der Dehydro-Diels-Alder-Reaktion, wobei immer Enantiomerenpaare auftreten. Es wird der diastereoselektive Aufbau von Naphthalenophanen und der enantiomeren reine Aufbau von Biarylen untersucht. Desweiteren werden die physikalischen Eigenschaften der erhaltenen Verbindungen, wie die Phosphoreszenz, Trennbarkeit der entstehenden Enantiomere und die Ringspannung beschrieben.}, language = {de} } @phdthesis{Patz2013, author = {Patz, Ronny}, title = {Information flows in the context of EU policy-making : affiliation networks and the post-2012 reform of the EU's Common Fisheries Policy}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70732}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Information flows in EU policy-making are heavily dependent on personal networks, both within the Brussels sphere but also reaching outside the narrow limits of the Belgian capital. These networks develop for example in the course of formal and informal meetings or at the sidelines of such meetings. A plethora of committees at European, transnational and regional level provides the basis for the establishment of pan-European networks. By studying affiliation to those committees, basic network structures can be uncovered. These affiliation network structures can then be used to predict EU information flows, assuming that certain positions within the network are advantageous for tapping into streams of information while others are too remote and peripheral to provide access to information early enough. This study has tested those assumptions for the case of the reform of the Common Fisheries Policy for the time after 2012. Through the analysis of an affiliation network based on participation in 10 different fisheries policy committees over two years (2009 and 2010), network data for an EU-wide network of about 1300 fisheries interest group representatives and more than 200 events was collected. The structure of this network showed a number of interesting patterns, such as - not surprisingly - a rather central role of Brussels-based committees but also close relations of very specific interests to the Brussels-cluster and stronger relations between geographically closer maritime regions. The analysis of information flows then focused on access to draft EU Commission documents containing the upcoming proposal for a new basic regulation of the Common Fisheries Policy. It was first documented that it would have been impossible to officially obtain this document and that personal networks were thus the most likely sources for fisheries policy actors to obtain access to these "leaks" in early 2011. A survey of a sample of 65 actors from the initial network supported these findings: Only a very small group had accessed the draft directly from the Commission. Most respondents who obtained access to the draft had received it from other actors, highlighting the networked flow of informal information in EU politics. Furthermore, the testing of the hypotheses connecting network positions and the level of informedness indicated that presence in or connections to the Brussels sphere had both advantages for overall access to the draft document and with regard to timing. Methodologically, challenges of both the network analysis and the analysis of information flows but also their relevance for the study of EU politics have been documented. In summary, this study has laid the foundation for a different way to study EU policy-making by connecting topical and methodological elements - such as affiliation network analysis and EU committee governance - which so far have not been considered together, thereby contributing in various ways to political science and EU studies.}, language = {en} } @phdthesis{Pauly2013, author = {Pauly, Dennis}, title = {Grenzf{\"a}lle der Subordination : Merkmale, Empirie und Theorie abh{\"a}ngiger Nebens{\"a}tze}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70275}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Gegenstand dieser Arbeit sind sog. nicht-kanonische bzw. unintegrierte Nebens{\"a}tze. Diese Nebens{\"a}tze zeichnen sich dadurch aus, dass sie sich mittels g{\"a}ngiger Kriterien (Satzgliedstatus, Verbletztstellung) nicht klar als koordiniert oder subordiniert beschreiben lassen. Das Ph{\"a}nomen nicht-kanonischer Nebens{\"a}tze ist ein Thema, welches in der Sprachwissenschaft generell seit den sp{\"a}ten Siebzigern (Davison 1979) diskutiert wird und sp{\"a}testens mit Fabricius-Hansen (1992) auch innerhalb der germanistischen Linguistik angekommen ist. Ein viel beachteter Komplex ist hierbei - neben der reinen Identifizierung nicht-kanonischer Satzgef{\"u}ge - meist auch die Erstellung einer Klassifikation zur Erfassung zumindest einiger nicht-kanonischer Gef{\"u}ge, wie dies etwa bei Fabricius-Hansen (1992) und Reis (1997) zu sehen ist. Das Ziel dieser Studie ist es, eine exhaustive Klassifikation der angesprochenen Nebensatztypen vorzunehmen. Dazu werden zun{\"a}chst - unter Zuhilfenahme von Korpusdaten - alle potentiellen Subordinationsmerkmale genauer untersucht, da die meisten bisherigen Studien zu diesem Thema die stets gleichen Merkmale als gegeben voraussetzen. Dabei wird sich herausstellen, dass nur eine kleine Anzahl von Merkmalen sich wirklich zweifelsfrei dazu eignet, Aufschluss {\"u}ber die Satzverkn{\"u}pfungsqualit{\"a}t zu geben. Die anschließend aufgestellte Taxonomie deutscher Nebens{\"a}tze wird schließlich einzig mit der Postulierung einer nicht-kanonischen Nebensatzklasse auskommen. Sie ist dar{\"u}ber hinaus auch in der Lage, die zahlreich vorkommenden Ausnahmef{\"a}lle zu erfassen. Dies heißt konkret, dass auch etwaige Nebens{\"a}tze, die sich aufgrund bestimmter Eigenschaften teilweise idiosynkratisch verhalten, einfach in die vorgeschlagene Klassifikation {\"u}bernommen werden k{\"o}nnen. In diesem Zuge werde ich weiterhin zeigen, wie eine Nebensatzklassifikation auch sog. sekund{\"a}ren Subordinationsmerkmalen gerecht werden kann, obwohl diese sich hinsichtlich der einzelnen Nebensatzklassen nicht einheitlich verhalten. Schließlich werde ich eine theoretische Modellierung der zuvor postulierten Taxonomie vornehmen, die auf Basis der HPSG mittels Merkmalsvererbung alle m{\"o}glichen Nebensatztypen zu erfassen imstande ist.}, language = {de} } @phdthesis{Theves2013, author = {Theves, Matthias}, title = {Bacterial motility and growth in open and confined environments}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70313}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {In the presence of a solid-liquid or liquid-air interface, bacteria can choose between a planktonic and a sessile lifestyle. Depending on environmental conditions, cells swimming in close proximity to the interface can irreversibly attach to the surface and grow into three-dimensional aggregates where the majority of cells is sessile and embedded in an extracellular polymer matrix (biofilm). We used microfluidic tools and time lapse microscopy to perform experiments with the polarly flagellated soil bacterium Pseudomonas putida (P. putida), a bacterial species that is able to form biofilms. We analyzed individual trajectories of swimming cells, both in the bulk fluid and in close proximity to a glass-liquid interface. Additionally, surface related growth during the early phase of biofilm formation was investigated. In the bulk fluid, P.putida shows a typical bacterial swimming pattern of alternating periods of persistent displacement along a line (runs) and fast reorientation events (turns) and cells swim with an average speed around 24 micrometer per second. We found that the distribution of turning angles is bimodal with a dominating peak around 180 degrees. In approximately six out of ten turning events, the cell reverses its swimming direction. In addition, our analysis revealed that upon a reversal, the cell systematically changes its swimming speed by a factor of two on average. Based on the experimentally observed values of mean runtime and rotational diffusion, we presented a model to describe the spreading of a population of cells by a run-reverse random walker with alternating speeds. We successfully recover the mean square displacement and, by an extended version of the model, also the negative dip in the directional autocorrelation function as observed in the experiments. The analytical solution of the model demonstrates that alternating speeds enhance a cells ability to explore its environment as compared to a bacterium moving at a constant intermediate speed. As compared to the bulk fluid, for cells swimming near a solid boundary we observed an increase in swimming speed at distances below d= 5 micrometer and an increase in average angular velocity at distances below d= 4 micrometer. While the average speed was maximal with an increase around 15\% at a distance of d= 3 micrometer, the angular velocity was highest in closest proximity to the boundary at d=1 micrometer with an increase around 90\% as compared to the bulk fluid. To investigate the swimming behavior in a confinement between two solid boundaries, we developed an experimental setup to acquire three-dimensional trajectories using a piezo driven objective mount coupled to a high speed camera. Results on speed and angular velocity were consistent with motility statistics in the presence of a single boundary. Additionally, an analysis of the probability density revealed that a majority of cells accumulated near the upper and lower boundaries of the microchannel. The increase in angular velocity is consistent with previous studies, where bacteria near a solid boundary were shown to swim on circular trajectories, an effect which can be attributed to a wall induced torque. The increase in speed at a distance of several times the size of the cell body, however, cannot be explained by existing theories which either consider the drag increase on cell body and flagellum near a boundary (resistive force theory) or model the swimming microorganism by a multipole expansion to account for the flow field interaction between cell and boundary. An accumulation of swimming bacteria near solid boundaries has been observed in similar experiments. Our results confirm that collisions with the surface play an important role and hydrodynamic interactions alone cannot explain the steady-state accumulation of cells near the channel walls. Furthermore, we monitored the number growth of cells in the microchannel under medium rich conditions. We observed that, after a lag time, initially isolated cells at the surface started to grow by division into colonies of increasing size, while coexisting with a comparable smaller number of swimming cells. After 5:50 hours, we observed a sudden jump in the number of swimming cells, which was accompanied by a breakup of bigger clusters on the surface. After approximately 30 minutes where planktonic cells dominated in the microchannel, individual swimming cells reattached to the surface. We interpret this process as an emigration and recolonization event. A number of complementary experiments were performed to investigate the influence of collective effects or a depletion of the growth medium on the transition. Similar to earlier observations on another bacterium from the same family we found that the release of cells to the swimming phase is most likely the result of an individual adaption process, where syntheses of proteins for flagellar motility are upregulated after a number of division cycles at the surface.}, language = {en} } @phdthesis{Berg2013, author = {Berg, Gregor}, title = {Virtual prototypes for the model-based elicitation and validation of collaborative scenarios}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69729}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Requirements engineers have to elicit, document, and validate how stakeholders act and interact to achieve their common goals in collaborative scenarios. Only after gathering all information concerning who interacts with whom to do what and why, can a software system be designed and realized which supports the stakeholders to do their work. To capture and structure requirements of different (groups of) stakeholders, scenario-based approaches have been widely used and investigated. Still, the elicitation and validation of requirements covering collaborative scenarios remains complicated, since the required information is highly intertwined, fragmented, and distributed over several stakeholders. Hence, it can only be elicited and validated collaboratively. In times of globally distributed companies, scheduling and conducting workshops with groups of stakeholders is usually not feasible due to budget and time constraints. Talking to individual stakeholders, on the other hand, is feasible but leads to fragmented and incomplete stakeholder scenarios. Going back and forth between different individual stakeholders to resolve this fragmentation and explore uncovered alternatives is an error-prone, time-consuming, and expensive task for the requirements engineers. While formal modeling methods can be employed to automatically check and ensure consistency of stakeholder scenarios, such methods introduce additional overhead since their formal notations have to be explained in each interaction between stakeholders and requirements engineers. Tangible prototypes as they are used in other disciplines such as design, on the other hand, allow designers to feasibly validate and iterate concepts and requirements with stakeholders. This thesis proposes a model-based approach for prototyping formal behavioral specifications of stakeholders who are involved in collaborative scenarios. By simulating and animating such specifications in a remote domain-specific visualization, stakeholders can experience and validate the scenarios captured so far, i.e., how other stakeholders act and react. This interactive scenario simulation is referred to as a model-based virtual prototype. Moreover, through observing how stakeholders interact with a virtual prototype of their collaborative scenarios, formal behavioral specifications can be automatically derived which complete the otherwise fragmented scenarios. This, in turn, enables requirements engineers to elicit and validate collaborative scenarios in individual stakeholder sessions - decoupled, since stakeholders can participate remotely and are not forced to be available for a joint session at the same time. This thesis discusses and evaluates the feasibility, understandability, and modifiability of model-based virtual prototypes. Similarly to how physical prototypes are perceived, the presented approach brings behavioral models closer to being tangible for stakeholders and, moreover, combines the advantages of joint stakeholder sessions and decoupled sessions.}, language = {en} } @phdthesis{Santan2013, author = {Santan, Harshal Diliprao}, title = {Synthesis and characterization of thermosensitive hydrogels derived from polysaccharides}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69793}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {In this work, thermosensitive hydrogels having tunable thermo-mechanical properties were synthesized. Generally the thermal transition of thermosensitive hydrogels is based on either a lower critical solution temperature (LCST) or critical micelle concentration/ temperature (CMC/ CMT). The temperature dependent transition from sol to gel with large volume change may be seen in the former type of thermosensitive hydrogels and is negligible in CMC/ CMT dependent systems. The change in volume leads to exclusion of water molecules, resulting in shrinking and stiffening of system above the transition temperature. The volume change can be undesired when cells are to be incorporated in the system. The gelation in the latter case is mainly driven by micelle formation above the transition temperature and further colloidal packing of micelles around the gelation temperature. As the gelation mainly depends on concentration of polymer, such a system could undergo fast dissolution upon addition of solvent. Here, it was envisioned to realize a thermosensitive gel based on two components, one responsible for a change in mechanical properties by formation of reversible netpoints upon heating without volume change, and second component conferring degradability on demand. As first component, an ABA triblockcopolymer (here: Poly(ethylene glycol)-b-poly(propylene glycol)-b-poly(ethylene glycol) (PEPE) with thermosensitive properties, whose sol-gel transition on the molecular level is based on micellization and colloidal jamming of the formed micelles was chosen, while for the additional macromolecular component crosslinking the formed micelles biopolymers were employed. The synthesis of the hydrogels was performed in two ways, either by physical mixing of compounds showing electrostatic interactions, or by covalent coupling of the components. Biopolymers (here: the polysaccharides hyaluronic acid, chondroitin sulphate, or pectin, as well as the protein gelatin) were employed as additional macromolecular crosslinker to simultaneously incorporate an enzyme responsiveness into the systems. In order to have strong ionic/electrostatic interactions between PEPE and polysaccharides, PEPE was aminated to yield predominantly mono- or di-substituted PEPEs. The systems based on aminated PEPE physically mixed with HA showed an enhancement in the mechanical properties such as, elastic modulus (G′) and viscous modulus (G′′) and a decrease of the gelation temperature (Tgel) compared to the PEPE at same concentration. Furthermore, by varying the amount of aminated PEPE in the composition, the Tgel of the system could be tailored to 27-36 °C. The physical mixtures of HA with di-amino PEPE (HA·di-PEPE) showed higher elastic moduli G′ and stability towards dissolution compared to the physical mixtures of HA with mono-amino PEPE (HA·mono-PEPE). This indicates a strong influence of electrostatic interaction between -COOH groups of HA and -NH2 groups of PEPE. The physical properties of HA with di-amino PEPE (HA·di-PEPE) compare beneficially with the physical properties of the human vitreous body, the systems are highly transparent, and have a comparable refractive index and viscosity. Therefore,this material was tested for a potential biological application and was shown to be non-cytotoxic in eluate and direct contact tests. The materials will in the future be investigated in further studies as vitreous body substitutes. In addition, enzymatic degradation of these hydrogels was performed using hyaluronidase to specifically degrade the HA. During the degradation of these hydrogels, increase in the Tgel was observed along with decrease in the mechanical properties. The aminated PEPE were further utilised in the covalent coupling to Pectin and chondroitin sulphate by using EDC as a coupling agent. Here, it was possible to adjust the Tgel (28-33 °C) by varying the grafting density of PEPE to the biopolymer. The grafting of PEPE to Pectin enhanced the thermal stability of the hydrogel. The Pec-g-PEPE hydrogels were degradable by enzymes with slight increase in Tgel and decrease in G′ during the degradation time. The covalent coupling of aminated PEPE to HA was performed by DMTMM as a coupling agent. This method of coupling was observed to be more efficient compared to EDC mediated coupling. Moreover, the purification of the final product was performed by ultrafiltration technique, which efficiently removed the unreacted PEPE from the final product, which was not sufficiently achieved by dialysis. Interestingly, the final products of these reaction were in a gel state and showed enhancement in the mechanical properties at very low concentrations (2.5 wt\%) near body temperature. In these hydrogels the resulting increase in mechanical properties was due to the combined effect of micelle packing (physical interactions) by PEPE and covalent netpoints between PEPE and HA. PEPE alone or the physical mixtures of the same components were not able to show thermosensitive behavior at concentrations below 16 wt\%. These thermosensitive hydrogels also showed on demand solubilisation by enzymatic degradation. The concept of thermosensitivity was introduced to 3D architectured porous hydrogels, by covalently grafting the PEPE to gelatin and crosslinking with LDI as a crosslinker. Here, the grafted PEPE resulted in a decrease in the helix formation in gelatin chains and after fixing the gelatin chains by crosslinking, the system showed an enhancement in the mechanical properties upon heating (34-42 °C) which was reversible upon cooling. A possible explanation of the reversible changes in mechanical properties is the strong physical interactions between micelles formed by PEPE being covalently linked to gelatin. Above the transition temperature, the local properties were evaluated by AFM indentation of pore walls in which an increase in elastic modulus (E) at higher temperature (37 °C) was observed. The water uptake of these thermosensitive architectured porous hydrogels was also influenced by PEPE and temperature (25 °C and 37 °C), showing lower water up take at higher temperature and vice versa. In addition, due to the lower water uptake at high temperature, the rate of hydrolytic degradation of these systems was found to be decreased when compared to pure gelatin architectured porous hydrogels. Such temperature sensitive architectured porous hydrogels could be important for e.g. stem cell culturing, cell differentiation and guided cell migration, etc. Altogether, it was possible to demonstrate that the crosslinking of micelles by a macromolecular crosslinker increased the shear moduli, viscosity, and stability towards dissolution of CMC-based gels. This effect could be likewise be realized by covalent or non-covalent mechanisms such as, micelle interactions, physical interactions of gelatin chains and physical interactions between gelatin chains and micelles. Moreover, the covalent grafting of PEPE will create additional net-points which also influence the mechanical properties of thermosensitive architectured porous hydrogels. Overall, the physical and chemical interactions and reversible physical interactions in such thermosensitive architectured porous hydrogels gave a control over the mechanical properties of such complex system. The hydrogels showing change of mechanical properties without a sol-gel transition or volume change are especially interesting for further study with cell proliferation and differentiation.}, language = {en} } @phdthesis{Toele2013, author = {T{\"o}le, Jonas Claudius}, title = {{\"U}ber die Arc-catFISH-Methode als neues Werkzeug zur Charakterisierung der Geschmacksverarbeitung im Hirnstamm der Maus}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70491}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Intensive Forschung hat in den vergangenen Jahrzehnten zu einer sehr detaillierten Charakterisierung des Geschmackssystems der S{\"a}ugetiere gef{\"u}hrt. Dennoch sind mit den bislang eingesetzten Methoden wichtige Fragestellungen unbeantwortet geblieben. Eine dieser Fragen gilt der Unterscheidung von Bitterstoffen. Die Zahl der Substanzen, die f{\"u}r den Menschen bitter schmecken und in Tieren angeborenes Aversionsverhalten ausl{\"o}sen, geht in die Tausende. Diese Substanzen sind sowohl von der chemischen Struktur als auch von ihrer Wirkung auf den Organismus sehr verschieden. W{\"a}hrend viele Bitterstoffe potente Gifte darstellen, sind andere in den Mengen, die mit der Nahrung aufgenommen werden, harmlos oder haben sogar positive Effekte auf den K{\"o}rper. Zwischen diesen Gruppen unterscheiden zu k{\"o}nnen, w{\"a}re f{\"u}r ein Tier von Vorteil. Ein solcher Mechanismus ist jedoch bei S{\"a}ugetieren nicht bekannt. Das Ziel dieser Arbeit war die Untersuchung der Verarbeitung von Geschmacksinformation in der ersten Station der Geschmacksbahn im Mausgehirn, dem Nucleus tractus solitarii (NTS), mit besonderem Augenmerk auf der Frage nach der Diskriminierung verschiedener Bitterstoffe. Zu diesem Zweck wurde eine neue Untersuchungsmethode f{\"u}r das Geschmackssystem etabliert, die die Nachteile bereits verf{\"u}gbarer Methoden umgeht und ihre Vorteile kombiniert. Die Arc-catFISH-Methode (cellular compartment analysis of temporal activity by fluorescent in situ hybridization), die die Charakterisierung der Antwort großer Neuronengruppen auf zwei Stimuli erlaubt, wurde zur Untersuchung geschmacksverarbeitender Zellen im NTS angewandt. Im Zuge dieses Projekts wurde erstmals eine stimulusinduzierte Arc-Expression im NTS gezeigt. Die ersten Ergebnisse offenbarten, dass die Arc-Expression im NTS spezifisch nach Stimulation mit Bitterstoffen auftritt und sich die Arc exprimierenden Neurone vornehmlich im gustatorischen Teil des NTS befinden. Dies weist darauf hin, dass Arc-Expression ein Marker f{\"u}r bitterverarbeitende gustatorische Neurone im NTS ist. Nach zweimaliger Stimulation mit Bittersubstanzen konnten {\"u}berlappende, aber verschiedene Populationen von Neuronen beobachtet werden, die unterschiedlich auf die drei verwendeten Bittersubstanzen Cycloheximid, Chininhydrochlorid und Cucurbitacin I reagierten. Diese Neurone sind vermutlich an der Steuerung von Abwehrreflexen beteiligt und k{\"o}nnten so die Grundlage f{\"u}r divergentes Verhalten gegen{\"u}ber verschiedenen Bitterstoffen bilden.}, language = {de} } @phdthesis{Fleischhauer2013, author = {Fleischhauer, Elisabeth}, title = {Morphological processing in children : an experimental study of German past participles}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70581}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {An important strand of research has investigated the question of how children acquire a morphological system using offline data from spontaneous or elicited child language. Most of these studies have found dissociations in how children apply regular and irregular inflection (Marcus et al. 1992, Weyerts \& Clahsen 1994, Rothweiler \& Clahsen 1993). These studies have considerably deepened our understanding of how linguistic knowledge is acquired and organised in the human mind. Their methodological procedures, however, do not involve measurements of how children process morphologically complex forms in real time. To date, little is known about how children process inflected word forms. The aim of this study is to investigate children's processing of inflected words in a series of on-line reaction time experiments. We used a cross-modal priming experiment to test for decompositional effects on the central level. We used a speeded production task and a lexical decision task to test for frequency effects on access level in production and recognition. Children's behaviour was compared to adults' behaviour towards three participle types (-t participles, e.g. getanzt 'danced' vs. -n participles with stem change, e.g. gebrochen 'broken' vs.-n participles without stem change, e.g. geschlafen 'slept'). For the central level, results indicate that -t participles but not -n participles have decomposed representations. For the access level, results indicate that -t participles are represented according to their morphemes and additionally as full forms, at least from the age of nine years onwards (Pinker 1999 and Clahsen et al. 2004). Further evidence suggested that -n participles are represented as full-form entries on access level and that -n participles without stem change may encode morphological structure (cf. Clahsen et al. 2003). Out data also suggests that processing strategies for -t participles are differently applied in recognition and production. These results provide evidence that children (within the age range tested) employ the same mechanisms for processing participles as adults. The child lexicon grows as children form additional full-form representations for -t participles on access level and elaborate their full-form lexical representations of -n participles on central level. These results are consistent with processing as explained in dual-system theories.}, language = {en} } @phdthesis{Nikolaeva2013, author = {Nikolaeva, Elena}, title = {Landslide kinematics and interactions studied in central Georgia by using synthetic aperture radar interferometry, optical imagery and inverse modeling}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70406}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Landslides are one of the biggest natural hazards in Georgia, a mountainous country in the Caucasus. So far, no systematic monitoring and analysis of the dynamics of landslides in Georgia has been made. Especially as landslides are triggered by extrinsic processes, the analysis of landslides together with precipitation and earthquakes is challenging. In this thesis I describe the advantages and limits of remote sensing to detect and better understand the nature of landslide in Georgia. The thesis is written in a cumulative form, composing a general introduction, three manuscripts and a summary and outlook chapter. In the present work, I measure the surface displacement due to active landslides with different interferometric synthetic aperture radar (InSAR) methods. The slow landslides (several cm per year) are well detectable with two-pass interferometry. In same time, the extremely slow landslides (several mm per year) could be detected only with time series InSAR techniques. I exemplify the success of InSAR techniques by showing hitherto unknown landslides, located in the central part of Georgia. Both, the landslide extent and displacement rate is quantified. Further, to determine a possible depth and position of potential sliding planes, inverse models were developed. Inverse modeling searches for parameters of source which can create observed displacement distribution. I also empirically estimate the volume of the investigated landslide using displacement distributions as derived from InSAR combined with morphology from an aerial photography. I adapted a volume formula for our case, and also combined available seismicity and precipitation data to analyze potential triggering factors. A governing question was: What causes landslide acceleration as observed in the InSAR data? The investigated area (central Georgia) is seismically highly active. As an additional product of the InSAR data analysis, a deformation area associated with the 7th September Mw=6.0 earthquake was found. Evidences of surface ruptures directly associated with the earthquake could not be found in the field, however, during and after the earthquake new landslides were observed. The thesis highlights that deformation from InSAR may help to map area prone landslides triggering by earthquake, potentially providing a technique that is of relevance for country wide landslide monitoring, especially as new satellite sensors will emerge in the coming years.}, language = {en} } @phdthesis{Gollrad2013, author = {Gollrad, Anja}, title = {Prosodic cue weighting in sentence comprehension}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-81954}, school = {Universit{\"a}t Potsdam}, pages = {148}, year = {2013}, abstract = {Gegenstand der Dissertation ist die Untersuchung der Gewichtung prosodischer Korrelate der Phrasierung im Deutschen, insbesondere der Dauer- und Grundfrequenzeigenschaften auf der Ebene der phonologischen Phrase (φ) und der Intonationsphrase (ι). F{\"u}r die prosodische Dom{\"a}ne der phonologischen Phrase und der Intonationsphrase gilt als belegt, dass sie h{\"a}upts{\"a}chlich durch phonetische Parameter der pr{\"a}finalen Dehnung (Lehiste, 1973; Klatt, 1976; Price et al., 1991; Turk \& White, 1999), der Pausendauer (Fant \& Kruckenberg, 1996) und der Ver{\"a}nderung der Grundfrequenz (Pierrehumbert, 1980) ausgedr{\"u}ckt werden, wobei die phonetischen grenzmarkierenden Eigenschaften eher quantitativer als qualitativer Natur sind. Ebenfalls ist bekannt, dass auf der anderen Seite H{\"o}rer diese phonetischen Eigenschaften der Sprecher nutzen, um die prosodische Struktur einer {\"A}ußerung zu ermitteln (Snedeker \& Trueswell, 2003; Kraljic \& Brennan, 2005). Perzeptuelle Evidenz aus dem Englischen und Niederl{\"a}ndischen deuten allerdings darauf hin, dass sich Sprachen hinsichtlich der entscheidenden Korrelate, die f{\"u}r die Perzeption der Dom{\"a}nen konsultiert werden, unterscheiden (Aasland \& Baum, 2003; Sanderman \& Collier, 1997; Scott, 1982; Streeter, 1978). Die grenzmarkierenden phonetischen Korrelate der Dom{\"a}nen werden in der Perzeption unterschiedlich stark gewichtet, was sich im Konzept eines sprachspezifischen prosodischen cue weightings ausdr{\"u}ckt. F{\"u}r das Deutsche ist allerdings nicht hinreichend bekannt, welche dieser drei phonetischen Parameter die wichtigste Rolle f{\"u}r die Perzeption der phonologischen Phrasengrenze und der Intonationsphrasengrenze spielt. Ziel der Dissertation war es, diejenigen phonetischen Merkmale zu identifizieren, die f{\"u}r die Perzeption der phonologischen Phrasengrenze und der Intonationsphrasengrenze entscheidend sind und sich somit f{\"u}r die Bildung der jeweiligen prosodischen Phrasengrenze als notwendig herausstellen. Die Identifikation und Gewichtung eines phonetischen Merkmals erfolgte in der vorliegenden Arbeit durch die Effekte prosodischer Manipulation der phonetischen Korrelate an phonologischen Phrasengrenzen und Intonationsphrasengrenzen auf die Disambiguierung lokaler syntaktischer Ambiguit{\"a}ten in der Perzeption. Der Einfluss einzelner phonetischer Merkmale wurde in einem forced-choice Experiment evaluiert, bei dem H{\"o}rern syntaktisch ambige Satzfragmente auditiv pr{\"a}sentiert wurden und ihnen anschließend die Aufgabe zukam, aus einer Auswahl an disambiguierenden Satzvervollst{\"a}ndigung zu w{\"a}hlen. Die Anzahl der ausgew{\"a}hlten Satzvervollst{\"a}ndigungen pro Satzbedingung {\"a}nderte sich in Abh{\"a}ngigkeit der prosodischen Manipulation der pr{\"a}finalen Dehnung, der Pausendauer und der Grundfrequenz, wodurch der Einfluss eines einzelnen phonetischen Merkmals auf den Disambiguierungsprozess sichtbar wurde. Ein phonetischer Parameter wurde genau dann als notwendig klassifiziert, wenn sich durch seine Manipulation die F{\"a}higkeit zur Disambiguierung der syntaktischen Strukturen signifikant reduzierte, oder g{\"a}nzlich scheiterte, und somit die Wahrnehmung prosodischer Kategorien beinflusst wurde (Heldner, 2001). Hat sich in der Perzeption ein phonetisches Merkmal als notwendig herausgestellt, wurde nachfolgend eine optimalit{\"a}tstheoretische Modellierung vorgeschlagen, die die phonetischen Eigenschaften auf eine (abstrakte) phonologische Strukturerstellung beschreibt. Dieser Verarbeitungsschritt entspricht dem Teilbereich des Perzeptionsprozesses, der in Boersma \& Hamann (2009), Escudero (2009) und F{\´e}ry et al. (2009) unter anderen als Phonetik-Phonologie-Mapping beschrieben wird. Die Dissertation hat folgende Hauptergebnisse hervorgebracht: (1) F{\"u}r die Perzeption phonologischer Phrasengrenzen und Intonationsphrasengrenzen werden nicht alle messbaren phonetischen Grenzmarkierungen gleichermaßen stark genutzt. Das phonetische Merkmal der pr{\"a}finalen Dehnung ist auf der Ebene der kleineren prosodischen Dom{\"a}ne, der phonologischen Phrase, notwendig. Die Information der Grundfrequenz in der Form von Grenzt{\"o}nen ist in der gr{\"o}ßeren Dom{\"a}ne der Intonationsphrase notwendig und damit ausschlaggebend f{\"u}r die Perzeption der prosodischen Phrasengrenze. (2) Auf der Ebene der φ-Phrase werden phonetische Eigenschaften der segmentalen Dauer in Form pr{\"a}finalen Dehnung zur Bildung abstrakter phonologischer Repr{\"a}sentationen herangezogen werden. L{\"a}ngenconstraints schreiben syntaktische Konstituenten aufgrund ihrer Inputdauern einer prosodischen Kategorie zu. Inputdauern der ersten Nominalphrase von 500ms und mehr signalisieren Finalit{\"a}t und sind durch eine φ- Grenze am rechten Rand markiert. Inputdauern von 400ms und weniger signalisieren Kontinuit{\"a}t und werden durch das Ausbleiben einer φ-Grenze am rechten Rand der ersten Nominalphrase markiert. Inputdauern, die zwischen den kritischen L{\"a}ngen von 400ms und 500ms variieren sind bez{\"u}glich der Bildung von φ- Grenzen ambig und k{\"o}nnen in der Perzeption nicht eindeutig disambiguiert werden. (3) Auf der Ebene der ι-Phrase wird die Bildung einer prosodischen Struktur durch die reine tonale Kontur (steigend oder fallend) an der ersten Nominalphrase gelenkt. Eine fallende Grundfrequenzkontur an der ersten Nominalphrase signalisiert Finalit{\"a}t und wird durch eine ι-Grenze am rechten Rand markiert. Eine steigende Kontur an der ersten Nominalphrase signalisiert phrasale Kontinuit{\"a}t und ist bei den vorliegenden S{\"a}tzen der Genitivbedingung gerade durch das Ausbleiben einer ι-Grenze auf der phonologischen Repr{\"a}sentationseben gekennzeichnet.}, language = {en} } @phdthesis{Discher2013, author = {Discher, Christian}, title = {Sprachkontakt, Migration und Variation}, series = {T{\"u}binger Beitr{\"a}ge zur Linguistik ; 549}, journal = {T{\"u}binger Beitr{\"a}ge zur Linguistik ; 549}, publisher = {Narr}, address = {T{\"u}bingen}, isbn = {978-3-8233-6915-8}, pages = {272}, year = {2013}, language = {de} } @phdthesis{Meyer2013, author = {Meyer, Sven}, title = {Wie ist liberale Eugenik m{\"o}glich?}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-77166}, school = {Universit{\"a}t Potsdam}, pages = {273}, year = {2013}, abstract = {Folgt tats{\"a}chlich aus einem liberalen Wertekanon eine generative Selbstbestimmung, eine weitgehende elterliche Handlungsfreiheit bei eugenischen Maßnahmen, wie es Vertreter einer „liberalen Eugenik" versichern? Diese Arbeit diskutiert die Rolle Staates und die Handlungsspielr{\"a}ume der Eltern bei der genetischen Gestaltung von Nachkommen im Rahmen eines liberalen Wertverst{\"a}ndnisses. Den Schwerpunkt/Fokus der Betrachtungen liegt hier Maßnahmen des genetic enhancement. Dar{\"u}ber hinaus wird auch das Verh{\"a}ltnis der „liberalen Eugenik" zur „autorit{\"a}ren Eugenik" neu beleuchtet. Die Untersuchung beginnt bei der Analyse zentraler liberaler Werte und Normen, wie Freiheit, Autonomie und Gerechtigkeit und deren Funktionen in der „liberalen Eugenik". Wobei nur sehr eingeschr{\"a}nkt von der „liberalen Eugenik" gesprochen werden kann, sondern viel mehr von Varianten einer „liberalen Eugenik". Dar{\"u}ber hinaus wird in dieser Arbeit die historische Entwicklung der „liberalen" und der „autorit{\"a}ren Eugenik", speziell des Sozialdarwinismus, untersucht und verglichen, insbesondere im Hinblick auf liberale Werte und Normen und der generativen Selbstbestimmung. Den Kern der Arbeit bildet der Vergleich der „liberalen Eugenik" mit der „liberalen Erziehung". Da hier die grundlegenden Aufgaben der Eltern, aber auch des Staates, analysiert und deren Verh{\"a}ltnis diskutiert wird. Es zeigt sich, dass sich aus einem liberalen Wertverst{\"a}ndnisses heraus keine umfangreiche generative Selbstbestimmung ableiten l{\"a}sst, sondern sich viel mehr staatlich kontrollierte enge Grenzen bei eugenischen Maßnahmen zum Wohle der zuk{\"u}nftigen Person, begr{\"u}nden. Zudem wurde der Weg zur autorit{\"a}ren Eugenik nicht durch die Abkehr von der generativen Selbstbestimmung geebnet, sondern viel mehr durch die {\"U}bertragung des Fortschrittsgedankens auf den Menschen selbst. Damit verliert die generative Selbstbestimmung auch ihre Funktion als Brandmauer gegen eine autorit{\"a}re Eugenik. Nicht der Verlust der generativen Selbstbestimmung, sondern viel mehr die Idee der Perfektionierung des Menschen muss kritisch betrachtet und letztlich abgelehnt werden. Ohne generative Selbstbestimmung und einer Perfektionierung des Menschen, bleibt nur eine Basis-Eugenik, bei der die Entwicklungsf{\"a}higkeit des Menschen sichergestellt wird, nicht jedoch seine Verbesserung. Dar{\"u}ber hinaus muss auch {\"u}ber eine Entwicklungsm{\"o}glichkeit des zuk{\"u}nftigen Menschen gesprochen werden, d. h. ein minimales Potential zu gesellschaftlicher Integration muss gegeben sein. Nur wenn tats{\"a}chlich keine M{\"o}glichkeiten seitens der Gesellschaft bestehen eine Person zu integrieren und dieser eine Entwicklungsm{\"o}glichkeit zu bieten, w{\"a}ren eugenische Maßnahmen als letztes Mittel akzeptabel.}, language = {de} } @phdthesis{Emer2013, author = {Emer, Wolfgang}, title = {Von der Konzeption zur Praxis}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-77199}, school = {Universit{\"a}t Potsdam}, pages = {IV, 123, A4, 271}, year = {2013}, abstract = {Die kumulative Dissertation zur Projektdidaktik tr{\"a}gt den Titel „Von der Konzeption zur Praxis: Zur Entwicklung der Projektdidaktik am Oberstufen-Kolleg Bielefeld und ihre Impulsgebung und Modellbildung f{\"u}r das deutsche Regelschulwesen". Die Dissertation versteht sich als beispielgebende Umsetzung und Implementierung der Projektdidaktik f{\"u}r das Regelschulsystem. Auf der Basis von 22 bereits erschienenen Publikationen und einer Monographie werden mit f{\"u}nf methodischen Zugriffen (bildungshistorisch, dichte Beschreibung, Aktionsforschung, empirische Untersuchung an Regelschulen und Implementierungsforschung, s. Kapitel 1) in sieben Kapiteln (2- 8) des systematischen ersten Teils die Entwicklung der Unterrichtsform Projektunterricht in der BRD, Projektbegriff und Weiterentwicklung des Konzepts, Methodik, Bewertung sowie Organisation des Projektunterrichts am Oberstufen-Kolleg, der Versuchsschule des Landes NRW, in Auseinandersetzung mit der allgemeinen Projektdidaktik dargestellt sowie Formen und Verfahren der erprobten Implementierung in das Regelschulsystem pr{\"a}sentiert. Ein Schlusskapitel (9) fasst die Ergebnisse zusammen. Im umfangreichen Anhang finden sich verschiedene Publikationen zu Aspekten der Projektdidaktik, auf die der systematische Teil jeweils Bezug nimmt. Die bildungshistorische Analyse (Kapitel 2) untersucht das Verh{\"a}ltnis von p{\"a}dagogischer Theorie und schulischer Praxis, die weder in Literatur und noch in Praxis gen{\"u}gend verbunden sind. Nach der Rezeption der gut erforschten Konzeptgeschichte p{\"a}dagogischer Theorie in Anlehnung an Dewey und Kilpatrick wird durch eine erste Analyse der „Praxisgeschichte" des Projektunterrichts auf ein Forschungsdesiderat hingewiesen, dies auch um die Projektpraxis am Oberstufen-Kolleg in Beziehung zu der in den Regelschulen setzen zu k{\"o}nnen. Dabei wurden seit 1975 sechs Entwicklungslinien herausgearbeitet: Start, Krise und ihre {\"U}berwindung durch {\"O}ffnung und Vernetzung (1975-1990), didaktisch-methodische Differenzierung und Notwendigkeit von Professionalisierung (ab 1990) sowie Schulentwicklung und Institutionalisierung (seit Ende der 1990er Jahre). Projektunterricht besteht am Oberstufen-Kolleg seit der Gr{\"u}ndung 1974 als fest eingerichtete Unterrichtsform (seit 2002 zweimal j{\"a}hrlich 2 Wochen) mit dem Ziel, f{\"u}r das Regelschulsystem die Projektdidaktik zu erproben und weiterzuentwickeln. Als wichtige praxisorientierte Ziele wurden ein praxistauglicher Begriff, Bildungswert und Kompetenzen im Unterschied zum Lehrgang herausgearbeitet (z.B. handlungs- und anwendungsorientierte Kompetenzen) und das Verh{\"a}ltnis zum Fachunterricht bestimmt (Kapitel 3). Letzteres wurde am Beispiel des Fachs Geschichte entwickelt und exemplarisch in Formen der Verzahnung dargestellt (Kapitel 6). Auch f{\"u}r die methodische Dimension galt, die allgemeine Projektdidaktik weiterzuentwickeln durch ihre Abgrenzung zu anderen Methoden der {\"O}ffnung von Schule und Unterricht (Kapitel 4). Dabei wurde als zentrales methodisches Prinzip die Handlungsorientierung bestimmt sowie sieben Phasen und jeweilige Handlungsschritte festgelegt. Besonders Planung und Rollenwechsel bed{\"u}rfen dabei besonderer Beachtung, um Selbstt{\"a}tigkeit der ProjektteilnehmerInnen zu erreichen. Verschiedene methodische „Et{\"u}den" ( z.B. Gruppenarbeit, recherchieren, sich {\"o}ffentlich verhalten), handlungsorientierte Vorformen und projektorientiertes Arbeiten sollten die Vollform Projektunterricht vorbereiten helfen. Die Bewertung von Projekten (Kapitel 5) stellt andere Anforderungen als der Lehrgang, weil sie unterschiedliche Bewertungsebenen (z.B. Prozessbedeutung, Produktbeurteilung, Gruppenbewertung) umfasst. Dazu sind am Oberstufen-Kolleg andere Bewertungsformen als die Ziffernnote entwickelt worden: z.B. ein „Reflexionsbericht" als individuelle R{\"u}ckmeldung von Sch{\"u}lerInnen und LehrerInnen und ein „Zertifikat" f{\"u}r besondere Leistungen im Projekt. Zentral f{\"u}r die Entwicklung von Projektunterricht ist jedoch die Organisationsfrage (Kapitel 7). Dazu bedarf es einer Organisationsgruppe Projekt, die die Unterrichtsform didaktisch betreut und in einem Hearing die angemeldeten Projekte ber{\"a}t. Das Oberstufen-Kolleg hat damit eine entwickelte „Projektkultur" organisatorisch umgesetzt. F{\"u}r eine empirische Untersuchung an sechs Regelschulen in Ostwestfalen ist dann eine idealtypische Merkmalsliste von schulischer „Projektkultur" als Untersuchungsinstrument entstanden, das zugleich als Leitlinie f{\"u}r Schulentwicklung im Bereich Projektlernen in den Regelschulen dienen kann. Zu dieser Implementierung (Kapitel 8) wurden Konzepte und Erfahrungen vom Oberstufen-Kolleg f{\"u}r schulinterne und schulexterne Fortbildungsformen sowie eine exemplarische Fortbildungseinheit entwickelt. So konnten in zahlreichen Lehrerfortbildungen durch die Versuchsschule Impulse f{\"u}r das Regelschulsystem gegeben werden.}, language = {de} } @phdthesis{Bach2013, author = {Bach, Christoph}, title = {Improving statistical seismicity models}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70591}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Several mechanisms are proposed to be part of the earthquake triggering process, including static stress interactions and dynamic stress transfer. Significant differences of these mechanisms are particularly expected in the spatial distribution of aftershocks. However, testing the different hypotheses is challenging because it requires the consideration of the large uncertainties involved in stress calculations as well as the appropriate consideration of secondary aftershock triggering which is related to stress changes induced by smaller pre- and aftershocks. In order to evaluate the forecast capability of different mechanisms, I take the effect of smaller--magnitude earthquakes into account by using the epidemic type aftershock sequence (ETAS) model where the spatial probability distribution of direct aftershocks, if available, is correlated to alternative source information and mechanisms. Surface shaking, rupture geometry, and slip distributions are tested. As an approximation of the shaking level, ShakeMaps are used which are available in near real-time after a mainshock and thus could be used for first-order forecasts of the spatial aftershock distribution. Alternatively, the use of empirical decay laws related to minimum fault distance is tested and Coulomb stress change calculations based on published and random slip models. For comparison, the likelihood values of the different model combinations are analyzed in the case of several well-known aftershock sequences (1992 Landers, 1999 Hector Mine, 2004 Parkfield). The tests show that the fault geometry is the most valuable information for improving aftershock forecasts. Furthermore, they reveal that static stress maps can additionally improve the forecasts of off--fault aftershock locations, while the integration of ground shaking data could not upgrade the results significantly. In the second part of this work, I focused on a procedure to test the information content of inverted slip models. This allows to quantify the information gain if this kind of data is included in aftershock forecasts. For this purpose, the ETAS model based on static stress changes, which is introduced in part one, is applied. The forecast ability of the models is systematically tested for several earthquake sequences and compared to models using random slip distributions. The influence of subfault resolution and segment strike and dip is tested. Some of the tested slip models perform very good, in that cases almost no random slip models are found to perform better. Contrastingly, for some of the published slip models, almost all random slip models perform better than the published slip model. Choosing a different subfault resolution hardly influences the result, as long the general slip pattern is still reproducible. Whereas different strike and dip values strongly influence the results depending on the standard deviation chosen, which is applied in the process of randomly selecting the strike and dip values.}, language = {en} } @phdthesis{Cirannek2013, author = {Cirannek, Vanessa}, title = {Die Exportplattform als Instrument der ausl{\"a}ndischen Marktversorgung}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71345}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Zur Versorgung ausl{\"a}ndischer M{\"a}rkte bedienen sich Unternehmen unterschiedlicher Versorgungsformen. Die proximity-concentration trade-off-Literatur betrachtet die Wahl zwischen Export und Auslandsproduktion und erkl{\"a}rt die Entstehung von internationalem Handel und horizontalen ausl{\"a}ndischen Direktinvestitionen. Das Standardmodell von Brainard (1993) integriert die Auslandsproduktion als alternative Versorgungsform zum Handel in ein allgemeines Gleichgewichtsmodell mit zwei L{\"a}ndern, monopolistischer Konkurrenz, steigenden Skalenertr{\"a}gen und Transportkosten. Im Gleichgewicht versorgen Unternehmen ausl{\"a}ndische M{\"a}rkte entweder durch Exporte oder eine Auslandsproduktion. Die real zu beobachtende Ko-Existenz von internationalem Handel und ausl{\"a}ndischen Direktinvestitionen auf der Unternehmensebene kann mit diesem Modell nicht erkl{\"a}rt werden. Im Rahmen dieser Arbeit wird die Exportplattform (EP) als m{\"o}gliche Antwort auf dieses Ph{\"a}nomen herangezogen. Eine Exportplattform ist eine Auslandsproduktion, durch die nicht nur der lokale Auslandsmarkt, sondern auch Drittl{\"a}nder versorgt werden. Im modelltheoretischen Teil dieser Arbeit wird ein partialanalytisches EP-Modell formuliert, dass auf Brainard (1993) aufbaut. Dabei wird ihr Modell um eine Mehr-L{\"a}nder-Welt mit heterogener Verteilungsstruktur erweitert und die Versorgungsalternative der EP-Exporte nach dem Beispiel von Neary (2002) integriert. Durch die analytische L{\"o}sung des partiellen Gleichgewichts l{\"a}sst sich die substitutive Beziehung zwischen Heimatexporten, Auslandsproduktion und EP-Exporten aufzeigen. Ferner kann die Wirkung der Versorgungskosten auf die Versorgungswahl analysiert werden. Dabei wird neben der analytischen Modellbeschreibung besonders auf die Gleichgewichtsbestimmung und die Existenz der Gleichgewichte eingegangen. Aufbauend auf den analytisch abzuleitenden Hypothesen wird das EP-Modell ferner einem empirischen Signifikanztest unterzogen. Unter Anwendung von nicht-linearen Regressionsverfahren wird die Wahl zwischen EP-Exporten und Auslandsproduktion, zwischen EP- und Heimatexporten sowie zwischen EP-Exporten und der EP-Produktion separat gesch{\"a}tzt. Hierf{\"u}r wird auf Daten der Automobilindustrie zur{\"u}ckgegriffen, welche die regionalen PKW-Produktions- und -Absatzdaten s{\"a}mtlicher Automobilhersteller in Osteuropa, Asien und Ozeanien umfassen.}, language = {de} } @phdthesis{Kroencke2013, author = {Kr{\"o}ncke, Klaus}, title = {Stability of Einstein Manifolds}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69639}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {This thesis deals with Einstein metrics and the Ricci flow on compact mani- folds. We study the second variation of the Einstein-Hilbert functional on Ein- stein metrics. In the first part of the work, we find curvature conditions which ensure the stability of Einstein manifolds with respect to the Einstein-Hilbert functional, i.e. that the second variation of the Einstein-Hilbert functional at the metric is nonpositive in the direction of transverse-traceless tensors. The second part of the work is devoted to the study of the Ricci flow and how its behaviour close to Einstein metrics is influenced by the variational be- haviour of the Einstein-Hilbert functional. We find conditions which imply that Einstein metrics are dynamically stable or unstable with respect to the Ricci flow and we express these conditions in terms of stability properties of the metric with respect to the Einstein-Hilbert functional and properties of the Laplacian spectrum.}, language = {en} } @phdthesis{Baumgart2013, author = {Baumgart, Natalie}, title = {Faltungseigenschaften des extrazellul{\"a}ren Proteins Internalin J und seine Cysteinleiter}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69603}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Internalin J (InlJ) geh{\"o}rt zu der Klasse der bakteriellen, cysteinhaltigen (leucine-rich repeat) LRR Proteine. Bei den Internalinen handelt es sich um meist invasions-assoziierte Proteine der Listerien. Die LRR-Dom{\"a}ne von InlJ ist aus 15 regelm{\"a}ßig wiederkehrenden, stark konservierten Sequenzeinheiten (repeats, 21 Aminos{\"a}uren) aufgebaut. Ein interessantes Detail dieses Internalins ist das stark konservierte Cystein innerhalb der repeats. Daraus ergibt sich eine ungew{\"o}hnliche Anordnung von 12 Cysteinen in einem Stapel. Die H{\"a}ufigkeit von Cysteinen in InlJ ist f{\"u}r ein extrazellul{\"a}res Protein von L. monocytogenes außergew{\"o}hnlich, und die Frage nach ihrer Funktion daher umso brennender. Im Vergleich zum ubiquit{\"a}ren Vorkommen der sogenannten repeat-Proteine in der Natur sind Studien zu ihrer Stabilit{\"a}t und Faltung nicht {\"a}quivalent vertreten. Die zentrale Eigenschaft der repeat-Proteine ist ihr modularer Aufbau, der durch einfache Topologie gekennzeichnet ist und auf kurzreichenden Wechselwirkungen basiert. Diese Topologie macht repeat-Proteine zu idealen Modellproteinen, um die stabilit{\"a}tsrelevanten Wechselwirkungen zu separieren und zuzuordnen. In der vorliegenden Arbeit wurde die Faltung und Entfaltung von InlJ umfassend charakterisiert und die Relevanz der Cysteine n{\"a}her beleuchtet. Die spektroskopische Charakterisierung von InlJ zeigte, dass dessen Faltungszustand durch zwei Tryptophane im N- und C-Terminus fluoreszenzspektroskopisch gut zug{\"a}nglich ist. Die thermodynamische Stabilit{\"a}t wurde mittels fluoreszenz-detektierten, Guanidiniumchlorid-induzierten Gleichgewichtsexperimenten bestimmt. Um die kinetischen Eigenschaften von InlJ zu erfassen, wurden die Faltungs- sowie die Entfaltungsreaktion spektroskopisch untersucht. Die Identifizierung der produktiven Faltungsreaktion war lediglich durch die Anwendung des reversen Doppelsprungexperiments m{\"o}glich. Die Auswertung erfolgte nach dem Zweizustandsmodell, wonach die Faltung dem „Alles-oder-Nichts" Prinzip folgt. Die G{\"u}ltigkeit dieser Annahme wurde durch die kinetische Charakterisierung best{\"a}tigt. Es wurde sowohl in den Gleichgewichtsexperimenten als auch in den kinetisch erhaltenen Daten eine hohe freie Stabilisierungsenthalpie festgestellt. Die hohe Stabilit{\"a}t von InlJ geht mit hoher Kooperativit{\"a}t einher. Die kinetischen Daten zeigen zudem, dass die hohe Kooperativit{\"a}t haupts{\"a}chlich der Faltungsreaktion entstammt. Der Tanford-Wert von 0.93 impliziert, dass die Oberfl{\"a}chen{\"a}nderung w{\"a}hrend der Faltung bereits zum gr{\"o}ßten Teil erfolgt ist, bevor der {\"U}bergangszustand ausgebildet wurde. Direkte strukturelle Informationen {\"u}ber den {\"U}bergangszustand wurden mit Hilfe von Mutationsstudien erhalten. Zu diesem Zweck wurden 12 der 14 Cysteine gegen ein Alanin ausgetauscht. Die repeats 1 bis 11 von InlJ beinhalten jeweils ein Cystein, deren Anordnung eine Leiter ergibt. Deren Substitutionen haben einen vergleichbar destabilisierenden Effekt auf InlJ von durchschnittlich 4.8 kJ/mol. Die Verlangsamung der Faltung deutet daraufhin, dass die Interaktionen der repeats 5 bis 11 im {\"U}bergangszustand bereits voll ausgebildet sind. Demnach liegt bei InlJ ein zentraler Faltungsnukleus vor. Im Rahmen dieser Promotionsarbeit wurde eine hohe Stabilit{\"a}t und ein stark-kooperatives Verhalten f{\"u}r das extrazellul{\"a}re Protein InlJ beobachtet. Diese Erkenntnisse k{\"o}nnten wichtige Beitr{\"a}ge zur Entwicklung artifizieller repeat-Proteine leisten, deren Verwendung sich stetig ausweitet.}, language = {de} } @phdthesis{Boehm2013, author = {B{\"o}hm, Christoph}, title = {Enriching the Web of Data with topics and links}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-68624}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {This thesis presents novel ideas and research findings for the Web of Data - a global data space spanning many so-called Linked Open Data sources. Linked Open Data adheres to a set of simple principles to allow easy access and reuse for data published on the Web. Linked Open Data is by now an established concept and many (mostly academic) publishers adopted the principles building a powerful web of structured knowledge available to everybody. However, so far, Linked Open Data does not yet play a significant role among common web technologies that currently facilitate a high-standard Web experience. In this work, we thoroughly discuss the state-of-the-art for Linked Open Data and highlight several shortcomings - some of them we tackle in the main part of this work. First, we propose a novel type of data source meta-information, namely the topics of a dataset. This information could be published with dataset descriptions and support a variety of use cases, such as data source exploration and selection. For the topic retrieval, we present an approach coined Annotated Pattern Percolation (APP), which we evaluate with respect to topics extracted from Wikipedia portals. Second, we contribute to entity linking research by presenting an optimization model for joint entity linking, showing its hardness, and proposing three heuristics implemented in the LINked Data Alignment (LINDA) system. Our first solution can exploit multi-core machines, whereas the second and third approach are designed to run in a distributed shared-nothing environment. We discuss and evaluate the properties of our approaches leading to recommendations which algorithm to use in a specific scenario. The distributed algorithms are among the first of their kind, i.e., approaches for joint entity linking in a distributed fashion. Also, we illustrate that we can tackle the entity linking problem on the very large scale with data comprising more than 100 millions of entity representations from very many sources. Finally, we approach a sub-problem of entity linking, namely the alignment of concepts. We again target a method that looks at the data in its entirety and does not neglect existing relations. Also, this concept alignment method shall execute very fast to serve as a preprocessing for further computations. Our approach, called Holistic Concept Matching (HCM), achieves the required speed through grouping the input by comparing so-called knowledge representations. Within the groups, we perform complex similarity computations, relation conclusions, and detect semantic contradictions. The quality of our result is again evaluated on a large and heterogeneous dataset from the real Web. In summary, this work contributes a set of techniques for enhancing the current state of the Web of Data. All approaches have been tested on large and heterogeneous real-world input.}, language = {en} } @phdthesis{Ganahl2013, author = {Ganahl, Joseph Patrick}, title = {Corruption, good governance, and the African state : a critical analysis of the political-economic foundations of orruption in Sub-Saharan Africa}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-248-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-65167}, school = {Universit{\"a}t Potsdam}, pages = {x, 300}, year = {2013}, abstract = {African states are often called corrupt indicating that the political system in Africa differs from the one prevalent in the economically advanced democracies. This however does not give us any insight into what makes corruption the ruling norm of African statehood. Thus we must turn to the overly neglected theoretical work on the political economy of Africa in order to determine how the poverty of governance in Africa is firmly anchored both in Africa's domestic socioeconomic reality, as well as in the region's role in the international economic order. Instead of focusing on increased monitoring, enforcement and formal democratic procedures, this book integrates economic analysis with political theory in order to arrive at a better understanding of the political-economic roots of corruption in Sub-Saharan Africa.}, language = {en} } @phdthesis{MostafaKamelAbdelfatah2013, author = {Mostafa Kamel Abdelfatah, Ali}, title = {Interactions of food proteins with plant phenolics - modulation of structural, techno- and bio-functional properties of proteins}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69033}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {The phenolic compounds as food components represent the largest group of secondary metabolites in plant foods. The phenolic compounds, e.g. chlorogenic acid (CQA), are susceptible to oxidation by enzymes specially, polyphenol oxidase (PPO) and at alkaline conditions. Both enzymatic and non-enzymatic oxidations occur in the presence of oxygen and produce quinone, which normally further react with other quinone to produce colored compounds (dimers), as well as is capable of undergoing a nucleophilic addition to proteins. The interactions of proteins with the phenolic compounds have received considerable attention in the recent years where, plant phenolic compounds have drawn increasing attention due to their antioxidant properties and their noticeable effects in the prevention of various oxidative stress associated diseases. Green coffee beans are one of the richest sources of chlorogenic acids. Therefore, a green coffee extract would provide an eligible food relevant source for phenolic compounds for modification of proteins. The interaction between 5-CQA and amino acid lysine showed decrease in both free CQA and amino acid groups and only a slight effect on the antioxidative capacity depending on the reaction time was found. Furthermore, this interaction showed a large number of intermediary substances of low intensities. The reaction of lysine with 5-CQA in a model system initially leads to formation of 3-CQA and 4-CQA (both are isomers of 5-CQA), oxidation giving rise to the formation of a dimer which subsequently forms an adduct with lysine to finally result in a benzacridine derivative as reported and confirmed with the aid of HPLC coupled with ESI-MSn. The benzacridine derivative containing a trihydroxy structural element, was found to be yellow, being very reactive with oxygen yielding semiquinone and quinone type of products with characteristic green colors. Finally, the optimal conditions for this interaction as assessed by both the loss of CQA and free amino groups of lysine can be given at pH 7 and 25°C, the interaction increasing with incubation time and depending also on the amount of tyrosinase present. Green coffee bean has a higher diversity and content of phenolics, where besides the CQA isomers and their esters, other conjugates like feruloylquinic acids were also identified, thus documenting differences in phenolic profiles for the two coffee types (Coffea arabica and Coffea robusta). Coffee proteins are modified by interactions with phenolic compounds during the extraction, where those from C. arabica are more susceptible to these interactions compared to C. robusta, and the polyphenol oxidase activity seems to be a crucial factor for the formation of these addition products. Moreover, In-gel digestion combined with MALDI-TOF-MS revealed that the most reactive and susceptible protein fractions to covalent reactions are the α-chains of the 11S storage protein. Thus, based on these results and those supplied by other research groups, a tentative list of possible adduct structures was derived. The diversity of the different CQA derivatives present in green coffee beans complicates the series of reactions occurring, providing a broad palette of reaction products. These interactions influence the properties of protein, where they exposed changes in the solubility and hydrophobicity of proteins compared to faba bean proteins (as control). Modification of milk whey protein products (primarily b-lactoglobulin) with coffee specific phenolics and commercial CQA under enzymatic and alkaline conditions seems to be affecting their chemical, structural and functional properties, where both modifications led to reduced free amino-,thiol groups and tryptophan content. We propose that the disulfide-thiol exchange in the C-terminus of b-lactoglobulin may be initiated by the redox conditions provided in the presence of CQA. The protein structure b-lactoglobulin thereupon becomes more disordered as simulated by molecular dynamic calculation. This unfolding process may additionally be supported by the reaction of the CQA at the proposed sites of modification of -amino groups of lysine (K77, K91, K138, K47) and the thiol group of cysteine (C121). These covalent modifications also decreased the solubility and hydrophobicity of b-lactoglobulin, moreover they provide modified protein samples with a high antioxidative power, thermally more stable as reflected by a higher Td, require less amount of energy to unfold and when emulsified with lutein esters, exhibit their higher stability against UV light. The MALDI-TOF and SDS-PAGE results revealed that proteins treated at alkaline conditions were more strongly modified than those treated under enzymatic conditions. Finally, the results showed a slight change in emulsifying properties of modified proteins.}, language = {en} } @phdthesis{BaumannWilke2013, author = {Baumann-Wilke, Maria}, title = {Combining body wave tomography, surface wave inversion, seismic interferometry and laboratory measurements to characterize the black shales on Bornholm at different scales}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69007}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Black shales are sedimentary rocks with a high content of organic carbon, which leads to a dark grayish to black color. Due to their potential to contain oil or gas, black shales are of great interest for the support of the worldwide energy supply. An integrated seismic investigation of the Lower Palaeozoic black shales was carried out at the Danish island Bornholm to locate the shallow-lying Alum Shale layer and its surrounding formations and to characterize its potential as a source rock. Therefore, two seismic experiments at a total of three crossing profiles were carried out in October 2010 and in June 2012 in the southern part of the island. Two different active measurements were conducted with either a weight drop source or a minivibrator. Additionally, the ambient noise field was recorded at the study location over a time interval of about one day, and also a laboratory analysis of borehole samples was carried out. The seismic profiles were positioned as close as possible to two scientific boreholes which were used for comparative purposes. The seismic field data was analyzed with traveltime tomography, surface wave inversion and seismic interferometry to obtain the P-wave and S-wave velocity models of the subsurface. The P-wave velocity models which were determined for all three profiles clearly locate the Alum Shale layer between the Komstad Limestone layer on top and the L{\ae}s{\aa} Sandstone Formation at the base of the models. The black shale layer has P-wave velocities around 3 km/s which are lower compared to the adjacent formations. Due to a very good agreement of the sonic log and the vertical velocity profiles of the two seismic lines, which are directly crossing the borehole where the sonic log was conducted, the reliability of the traveltime tomography is proven. A correlation of the seismic velocities with the content of organic carbon is an important task for the characterization of the reservoir properties of a black shale formation. It is not possible without calibration but in combination with a full 2D tomographic image of the subsurface it gives the subsurface distribution of the organic material. The S-wave model obtained with surface wave inversion of the vibroseis data of one of the profiles images the Alum Shale layer also very well with S-wave velocities around 2 km/s. Although individual 1D velocity models for each of the source positions were determined, the subsurface S-wave velocity distribution is very uniform with a good match between the single models. A really new approach described here is the application of seismic interferometry to a really small study area and a quite short time interval. Also new is the selective procedure of only using time windows with the best crosscorrelation signals to achieve the final interferograms. Due to the small scale of the interferometry even P-wave signals can be observed in the final crosscorrelations. In the laboratory measurements the seismic body waves were recorded for different pressure and temperature stages. Therefore, samples of different depths of the Alum Shale were available from one of the scientific boreholes at the study location. The measured velocities have a high variance with changing pressure or temperature. Recordings with wave propagation both parallel and perpendicular to the bedding of the samples reveal a great amount of anisotropy for the P-wave velocity, whereas the S-wave velocity is almost independent of the wave direction. The calculated velocity ratio is also highly anisotropic with very low values for the perpendicular samples and very high values for the parallel ones. Interestingly, the laboratory velocities of the perpendicular samples are comparable to the velocities of the field experiments indicating that the field measurements are sensitive to wave propagation in vertical direction. The velocity ratio is also calculated with the P-wave and S-wave velocity models of the field experiments. Again, the Alum Shale can be clearly separated from the adjacent formations because it shows overall very low vP/vS ratios around 1.4. The very low velocity ratio indicates the content of gas in the black shale formation. With the combination of all the different methods described here, a comprehensive interpretation of the seismic response of the black shale layer can be made and the hydrocarbon source rock potential can be estimated.}, language = {en} } @phdthesis{Garoufi2013, author = {Garoufi, Konstantina}, title = {Interactive generation of effective discourse in situated context : a planning-based approach}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69108}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {As our modern-built structures are becoming increasingly complex, carrying out basic tasks such as identifying points or objects of interest in our surroundings can consume considerable time and cognitive resources. In this thesis, we present a computational approach to converting contextual information about a person's physical environment into natural language, with the aim of helping this person identify given task-related entities in their environment. Using efficient methods from automated planning - the field of artificial intelligence concerned with finding courses of action that can achieve a goal -, we generate discourse that interactively guides a hearer through completing their task. Our approach addresses the challenges of controlling, adapting to, and monitoring the situated context. To this end, we develop a natural language generation system that plans how to manipulate the non-linguistic context of a scene in order to make it more favorable for references to task-related objects. This strategy distributes a hearer's cognitive load of interpreting a reference over multiple utterances rather than one long referring expression. Further, to optimize the system's linguistic choices in a given context, we learn how to distinguish speaker behavior according to its helpfulness to hearers in a certain situation, and we model the behavior of human speakers that has been proven helpful. The resulting system combines symbolic with statistical reasoning, and tackles the problem of making non-trivial referential choices in rich context. Finally, we complement our approach with a mechanism for preventing potential misunderstandings after a reference has been generated. Employing remote eye-tracking technology, we monitor the hearer's gaze and find that it provides a reliable index of online referential understanding, even in dynamically changing scenes. We thus present a system that exploits hearer gaze to generate rapid feedback on a per-utterance basis, further enhancing its effectiveness. Though we evaluate our approach in virtual environments, the efficiency of our planning-based model suggests that this work could be a step towards effective conversational human-computer interaction situated in the real world.}, language = {en} } @phdthesis{Buchholz2013, author = {Buchholz, Claus}, title = {Politikgestaltung durch institutionalisierte Evaluationsverfahren? : Eine Analyse am Beispiel der Forschungspolitik der Europ{\"a}ischen Union}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69047}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Die vorliegende Arbeit besch{\"a}ftigt sich mit einer klassischen aber noch immer zentralen und aktuellen Frage der Evaluationsforschung, der Hinterfragung der Verwendung bzw. Wirksamkeit von Evaluationsverfahren. Vor dem Hintergrund der seit Ende der 1990er Jahre vor allem in Europa starken Zunahme von institutionalisierten Politik-Evaluationsverfahren sowie der zugleich zunehmenden Kritik dieser Verfahren in Wissenschaft und Praxis, untersucht die Arbeit diese Wirksamkeit am Fallbeispiel der Forschungspolitik der Europ{\"a}ischen Union. Aufbauend auf einer Aufarbeitung des Forschungsstandes zur Evaluationsverwendungsforschung und einer Vorstellung des gew{\"a}hlten Politikfeldes sowie der spezifischen Evaluationspraxis, erfolgt dazu eine systematische Gegen{\"u}berstellung der zentralen Evaluationsempfehlungen und der Entwicklung im Politikfeld {\"u}ber die vergangenen 15 Jahre. Im Ergebnis kommt die Arbeit zu der Feststellung eines ({\"u}berraschend) hohen Ausmaßes an Entsprechung der Evaluationsempfehlungen mit der Politikentwicklung im untersuchten Fallbeispiel. Auf der Basis der Untersuchung des Fallbeispiels aber auch unter Heranziehung weiterer empirischer Beitr{\"a}ge in der Literatur ist damit der Behauptung der fehlenden Wirksamkeit der institutionalisierten Evaluation auf die Politikgestaltung klar zu widersprechen. Eine weitergehende Diskussion des Ergebnisses der Fallstudie legt dar{\"u}ber hinaus nahe, dass einige spezifische Faktoren und Bedingungen die Wirksamkeit der Evaluationsverfahren im untersuchten Fallbeispiel positiv zu beeinflussen scheinen. Im Einzelnen sind dies: der Charakter und die Auspr{\"a}gung der Evaluationsempfehlungen, das spezifische institutionelle Umfeld der Evaluation sowie das spezifische 'politische Klima'. Aus dem Ergebnis l{\"a}sst sich andererseits aber auch folgern, dass insbesondere im Hinblick auf die Akzeptanzproblematik eine Verst{\"a}rkung der Bem{\"u}hungen zur Wahrnehmung der Evaluations-wirksamkeit auf Seiten aller Beteiligten geboten scheint. Die Arbeit stellt hierzu abschließend einige Vorschl{\"a}ge und Ideen zusammen, die diese Wahrnehmung verbessern k{\"o}nnen.}, language = {de} } @phdthesis{Schlolaut2013, author = {Schlolaut, Gordon}, title = {Varve and event layer chronology of Lake Suigetsu (Japan) back to 40 kyr BP and contribution to the international consensus atmospheric radiocarbon calibration curve}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69096}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {The main intention of the PhD project was to create a varve chronology for the Suigetsu Varves 2006' (SG06) composite profile from Lake Suigetsu (Japan) by thin section microscopy. The chronology was not only to provide an age-scale for the various palaeo-environmental proxies analysed within the SG06 project, but also and foremost to contribute, in combination with the SG06 14C chronology, to the international atmospheric radiocarbon calibration curve (IntCal). The SG06 14C data are based on terrestrial leaf fossils and therefore record atmospheric 14C values directly, avoiding the corrections necessary for the reservoir ages of the marine datasets, which are currently used beyond the tree-ring limit in the IntCal09 dataset (Reimer et al., 2009). The SG06 project is a follow up of the SG93 project (Kitagawa \& van der Plicht, 2000), which aimed to produce an atmospheric calibration dataset, too, but suffered from incomplete core recovery and varve count uncertainties. For the SG06 project the complete Lake Suigetsu sediment sequence was recovered continuously, leaving the task to produce an improved varve count. Varve counting was carried out using a dual method approach utilizing thin section microscopy and micro X-Ray Fluorescence (µXRF). The latter was carried out by Dr. Michael Marshall in cooperation with the PhD candidate. The varve count covers 19 m of composite core, which corresponds to the time frame from ≈10 to ≈40 kyr BP. The count result showed that seasonal layers did not form in every year. Hence, the varve counts from either method were incomplete. This rather common problem in varve counting is usually solved by manual varve interpolation. But manual interpolation often suffers from subjectivity. Furthermore, sedimentation rate estimates (which are the basis for interpolation) are generally derived from neighbouring, well varved intervals. This assumes that the sedimentation rates in neighbouring intervals are identical to those in the incompletely varved section, which is not necessarily true. To overcome these problems a novel interpolation method was devised. It is computer based and automated (i.e. avoids subjectivity and ensures reproducibility) and derives the sedimentation rate estimate directly from the incompletely varved interval by statistically analysing distances between successive seasonal layers. Therefore, the interpolation approach is also suitable for sediments which do not contain well varved intervals. Another benefit of the novel method is that it provides objective interpolation error estimates. Interpolation results from the two counting methods were combined and the resulting chronology compared to the 14C chronology from Lake Suigetsu, calibrated with the tree-ring derived section of IntCal09 (which is considered accurate). The varve and 14C chronology showed a high degree of similarity, demonstrating that the novel interpolation method produces reliable results. In order to constrain the uncertainties of the varve chronology, especially the cumulative error estimates, U-Th dated speleothem data were used by linking the low frequency 14C signal of Lake Suigetsu and the speleothems, increasing the accuracy and precision of the Suigetsu calibration dataset. The resulting chronology also represents the age-scale for the various palaeo-environmental proxies analysed in the SG06 project. One proxy analysed within the PhD project was the distribution of event layers, which are often representatives of past floods or earthquakes. A detailed microfacies analysis revealed three different types of event layers, two of which are described here for the first time for the Suigetsu sediment. The types are: matrix supported layers produced as result of subaqueous slope failures, turbidites produced as result of landslides and turbidites produced as result of flood events. The former two are likely to have been triggered by earthquakes. The vast majority of event layers was related to floods (362 out of 369), which allowed the construction of a respective chronology for the last 40 kyr. Flood frequencies were highly variable, reaching their greatest values during the global sea level low-stand of the Glacial, their lowest values during Heinrich Event 1. Typhoons affecting the region represent the most likely control on the flood frequency, especially during the Glacial. However, also local, non-climatic controls are suggested by the data. In summary, the work presented here expands and revises knowledge on the Lake Suigetsu sediment and enabls the construction of a far more precise varve chronology. The 14C calibration dataset is the first such derived from lacustrine sediments to be included into the (next) IntCal dataset. References: Kitagawa \& van der Plicht, 2000, Radiocarbon, Vol 42(3), 370-381 Reimer et al., 2009, Radiocarbon, Vol 51(4), 1111-1150}, language = {en} } @phdthesis{Morad2013, author = {Morad, Iris}, title = {Freiheit und Verantwortung : {\"U}berlegungen im Anschluss an Peter Bieri}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69215}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {In der Diskussion {\"u}ber Freiheit und Verantwortung vertritt die Hirnforschung die These, dass wir determiniert sind und unser Gehirn es ist, das denkt und entscheidet. Aus diesem Grunde k{\"o}nne uns f{\"u}r unsere Entscheidungen und Handlungen auch keine Verantwortung zugewiesen werden. Die Philosophie versucht in dieser Diskussion zu kl{\"a}ren, ob wir trotz Determiniertheit f{\"u}r unsere Entscheidungen und Urteile verantwortlich sind oder ob Vereinbarkeit von Freiheit und Determinismus grunds{\"a}tzlich nicht m{\"o}glich ist. Diese Fragen stellt diese Untersuchung {\"u}ber Freiheit und Verantwortung nicht. In dieser Untersuchung wird ein gewisses Maß an Freiheit vorausgesetzt, weil diese Annahme der erste Schritt f{\"u}r unsere Freiheit ist. In dieser Arbeit geht es um die Verbindung von Freiheit und Verantwortung und was diese Verbindung in unserem Menschsein und Miteinander bedeutet. Ziel ist es, zu zeigen, dass wir uns zus{\"a}tzliche Freiheit aneignen k{\"o}nnen, dass Bildung f{\"u}r unsere Freiheit n{\"o}tig und dass Freiheit ohne Verantwortung nicht m{\"o}glich ist. Die Untersuchung schließt sich Peter Bieris Thesen an, dass Aneignung von Freiheit und Bildung, die weder als Schul- noch als Ausbildung zu verstehen ist, m{\"o}glich und n{\"o}tig sind, um verantwortlich entscheiden und handeln zu k{\"o}nnen, lehnt jedoch Peter Bieris These ab, dass bedingte Freiheit Voraussetzung f{\"u}r unsere Freiheit ist. Zudem geht diese Arbeit {\"u}ber Peter Bieri hinaus, indem sie eine L{\"o}sungsm{\"o}glichkeit f{\"u}r unsere Freiheit und der damit verbundenen Verantwortlichkeit anbietet. Als L{\"o}sung wird eine Bildung vorgeschlagen, die uns die Verbundenheit mit den anderen und die Abh{\"a}ngigkeit von den anderen zeigt und die die Rechte und Bed{\"u}rfnisse der anderen ebenso anerkennen l{\"a}sst wie unsere eigenen. Es ist eine Bildung, die nicht nur Wissen, sondern auch bestimmte rationale und emotionale Kompetenzen beinhaltet. Es ist eine Bildung, die als lern- und lehrbar angesehen wird. Um diese Bildung als eine Notwendigkeit f{\"u}r unsere Freiheit und Verantwortlichkeit uns und den anderen gegen{\"u}ber vermitteln zu k{\"o}nnen, ist es wichtig, uns in unserem Wesen verstehen. Deshalb werden in dieser Arbeit Faktoren dargestellt, die auf uns wirken und die uns als Menschen ausmachen. Es sind Faktoren, die auf unsere Freiheit und Verantwortung Einfluss nehmen, indem sie unsere Entscheidungen, unser Urteilsverm{\"o}gen und in diesem Sinne auch unsere Handlungen erm{\"o}glichen oder einschr{\"a}nken. Durch die Darstellung dieser Faktoren werden wir auf unsere M{\"o}glichkeiten hingewiesen, die uns unser Leben in Selbstverantwortung und in Verantwortlichkeit den anderen gegen{\"u}ber gestalten lassen. In dieser Untersuchung wird gezeigt, dass Freiheit ohne Verantwortung nicht m{\"o}glich ist und es wird gezeigt, dass wir, wenn wir unsere Verantwortung abgeben, unsere Freiheit verlieren.}, language = {de} } @phdthesis{Thomas2013, author = {Thomas, Bj{\"o}rn Daniel}, title = {Analysis and management of low flows in small catchments of Brandenburg, Germany}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69247}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Water management and environmental protection is vulnerable to extreme low flows during streamflow droughts. During the last decades, in most rivers of Central Europe summer runoff and low flows have decreased. Discharge projections agree that future decrease in runoff is likely for catchments in Brandenburg, Germany. Depending on the first-order controls on low flows, different adaption measures are expected to be appropriate. Small catchments were analyzed because they are expected to be more vulnerable to a changing climate than larger rivers. They are mainly headwater catchments with smaller ground water storage. Local characteristics are more important at this scale and can increase vulnerability. This thesis mutually evaluates potential adaption measures to sustain minimum runoff in small catchments of Brandenburg, Germany, and similarities of these catchments regarding low flows. The following guiding questions are addressed: (i) Which first-order controls on low flows and related time scales exist? (ii) Which are the differences between small catchments regarding low flow vulnerability? (iii) Which adaption measures to sustain minimum runoff in small catchments of Brandenburg are appropriate considering regional low flow patterns? Potential adaption measures to sustain minimum runoff during periods of low flows can be classified into three categories: (i) increase of groundwater recharge and subsequent baseflow by land use change, land management and artificial ground water recharge, (ii) increase of water storage with regulated outflow by reservoirs, lakes and wetland water management and (iii) regional low flow patterns have to be considered during planning of measures with multiple purposes (urban water management, waste water recycling and inter-basin water transfer). The question remained whether water management of areas with shallow groundwater tables can efficiently sustain minimum runoff. Exemplary, water management scenarios of a ditch irrigated area were evaluated using the model Hydrus-2D. Increasing antecedent water levels and stopping ditch irrigation during periods of low flows increased fluxes from the pasture to the stream, but storage was depleted faster during the summer months due to higher evapotranspiration. Fluxes from this approx. 1 km long pasture with an area of approx. 13 ha ranged from 0.3 to 0.7 l\s depending on scenario. This demonstrates that numerous of such small decentralized measures are necessary to sustain minimum runoff in meso-scale catchments. Differences in the low flow risk of catchments and meteorological low flow predictors were analyzed. A principal component analysis was applied on daily discharge of 37 catchments between 1991 and 2006. Flows decreased more in Southeast Brandenburg according to meteorological forcing. Low flow risk was highest in a region east of Berlin because of intersection of a more continental climate and the specific geohydrology. In these catchments, flows decreased faster during summer and the low flow period was prolonged. A non-linear support vector machine regression was applied to iteratively select meteorological predictors for annual 30-day minimum runoff in 16 catchments between 1965 and 2006. The potential evapotranspiration sum of the previous 48 months was the most important predictor (r²=0.28). The potential evapotranspiration of the previous 3 months and the precipitation of the previous 3 months and last year increased model performance (r²=0.49, including all four predictors). Model performance was higher for catchments with low yield and more damped runoff. In catchments with high low flow risk, explanatory power of long term potential evapotranspiration was high. Catchments with a high low flow risk as well as catchments with a considerable decrease in flows in southeast Brandenburg have the highest demand for adaption. Measures increasing groundwater recharge are to be preferred. Catchments with high low flow risk showed relatively deep and decreasing groundwater heads allowing increased groundwater recharge at recharge areas with higher altitude away from the streams. Low flows are expected to stay low or decrease even further because long term potential evapotranspiration was the most important low flow predictor and is projected to increase during climate change. Differences in low flow risk and runoff dynamics between catchments have to be considered for management and planning of measures which do not only have the task to sustain minimum runoff.}, language = {en} } @phdthesis{Patra2013, author = {Patra, Pintu}, title = {Population dynamics of bacterial persistence}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69253}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {The life of microorganisms is characterized by two main tasks, rapid growth under conditions permitting growth and survival under stressful conditions. The environments, in which microorganisms dwell, vary in space and time. The microorganisms innovate diverse strategies to readily adapt to the regularly fluctuating environments. Phenotypic heterogeneity is one such strategy, where an isogenic population splits into subpopulations that respond differently under identical environments. Bacterial persistence is a prime example of such phenotypic heterogeneity, whereby a population survives under an antibiotic attack, by keeping a fraction of population in a drug tolerant state, the persister state. Specifically, persister cells grow more slowly than normal cells under growth conditions, but survive longer under stress conditions such as the antibiotic administrations. Bacterial persistence is identified experimentally by examining the population survival upon an antibiotic treatment and the population resuscitation in a growth medium. The underlying population dynamics is explained with a two state model for reversible phenotype switching in a cell within the population. We study this existing model with a new theoretical approach and present analytical expressions for the time scale observed in population growth and resuscitation, that can be easily used to extract underlying model parameters of bacterial persistence. In addition, we recapitulate previously known results on the evolution of such structured population under periodically fluctuating environment using our simple approximation method. Using our analysis, we determine model parameters for Staphylococcus aureus population under several antibiotics and interpret the outcome of cross-drug treatment. Next, we consider the expansion of a population exhibiting phenotype switching in a spatially structured environment consisting of two growth permitting patches separated by an antibiotic patch. The dynamic interplay of growth, death and migration of cells in different patches leads to distinct regimes in population propagation speed as a function of migration rate. We map out the region in parameter space of phenotype switching and migration rate to observe the condition under which persistence is beneficial. Furthermore, we present an extended model that allows mutation from the two phenotypic states to a resistant state. We find that the presence of persister cells may enhance the probability of resistant mutation in a population. Using this model, we explain the experimental results showing the emergence of antibiotic resistance in a Staphylococcus aureus population upon tobramycin treatment. In summary, we identify several roles of bacterial persistence, such as help in spatial expansion, development of multidrug tolerance and emergence of antibiotic resistance. Our study provides a theoretical perspective on the dynamics of bacterial persistence in different environmental conditions. These results can be utilized to design further experiments, and to develop novel strategies to eradicate persistent infections.}, language = {en} } @phdthesis{Ganesh2013, author = {Ganesh, Bhanu Priya}, title = {Host-microbe interactions in the inflamed gut}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69558}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Initiation and perpetuation of inflammatory bowel diseases (IBD) may result from an exaggerated mucosal immune response to the luminal microbiota in a susceptible host. We proposed that this may be caused either 1) by an abnormal microbial composition or 2) by weakening of the protective mucus layer due to excessive mucus degradation, which may lead to an easy access of luminal antigens to the host mucosa triggering inflammation. We tested whether the probiotic Enterococcus faecium NCIMB 10415 (NCIMB) is capable of reducing chronic gut inflammation by changing the existing gut microbiota composition and aimed to identify mechanisms that are involved in possible beneficial effects of the probiotic. To identify health-promoting mechanisms of the strain, we used interleukin (IL)-10 deficient mice that spontaneously develop gut inflammation and fed these mice a diet containing NCIMB (106 cells g-1) for 3, 8 and 24 weeks, respectively. Control mice were fed an identically composed diet but without the probiotic strain. No clear-cut differences between the animals were observed in pro-inflammatory cytokine gene expression and in intestinal microbiota composition after probiotic supplementation. However, we observed a low abundance of the mucin-degrading bacterium Akkermansia muciniphila in the mice that were fed NCIMB for 8 weeks. These low cell numbers were associated with significantly lower interferon gamma (IFN-γ) and IFN-γ-inducible protein (IP-10) mRNA levels as compared to the NCIMB-treated mice that were killed after 3 and 24 weeks of intervention. In conclusion, NCIMB was not capable of reducing gut inflammation in the IL-10-/- mouse model. To further identify the exact role of A. muciniphila and uncover a possible interaction between this bacterium, NCIMB and the host in relation to inflammation, we performed in vitro studies using HT-29 colon cancer cells. The HT-29 cells were treated with bacterial conditioned media obtained by growing either A. muciniphila (AM-CM) or NCIMB (NCIMB-CM) or both together (COMB-CM) in Dulbecco's Modified Eagle Medium (DMEM) for 2 h at 37 °C followed by bacterial cell removal. HT-29 cells treated with COMB-CM displayed reduced cell viability after 18 h (p<0.01) and no viable cells were detected after 24 h of treatment, in contrast to the other groups or heated COMB-CM. Detection of activated caspase-3 in COMB-CM treated groups indicated that death of the HT-29 cells was brought about by apoptosis. It was concluded that either NCIMB or A. muciniphila produce a soluble and heat-sensitive factor during their concomitant presence that influences cell viability in an in vitro system. We currently hypothesize that this factor is a protein, which has not yet been identified. Based on the potential effect of A. muciniphila on inflammation (in vivo) and cell-viability (in vitro) in the presence of NCIMB, we investigated how the presence of A. muciniphila affects the severity of an intestinal Salmonella enterica Typhimurium (STm)-induced gut inflammation using gnotobiotic C3H mice with a background microbiota of eight bacterial species (SIHUMI, referred to as simplified human intestinal microbiota). Presence of A. muciniphila in STm-infected SIHUMI (SIHUMI-AS) mice caused significantly increased histopathology scores and elevated mRNA levels of IFN-γ, IP-10, tumor necrosis factor alpha (TNF-α), IL-12, IL-17 and IL-6 in cecal and colonic tissue. The number of mucin filled goblet cells was 2- to 3- fold lower in cecal tissue of SIHUMI-AS mice compared to SIHUMI mice associated with STm (SIHUMI-S) or A. muciniphila (SIHUMI-A) or SIHUMI mice. Reduced goblet cell numbers significantly correlated with increased IFN-γ (r2 = -0.86, ***P<0.001) in all infected mice. In addition, loss of cecal mucin sulphation was observed in SIHUMI-AS mice. Concomitant presence of A. muciniphila and STm resulted in a drastic change in microbiota composition of the SIHUMI consortium. The proportion of Bacteroides thetaiotaomicron in SIHUMI, SIHUMI-A and SIHUMI-S mice made up to 80-90\% but was completely taken over by STm in SIHUMI-AS mice contributing 94\% to total bacteria. These results suggest that A. muciniphila exacerbates STm-induced intestinal inflammation by its ability to disturb host mucus homeostasis. In conclusion, abnormal microbiota composition together with excessive mucus degradation contributes to severe intestinal inflammation in a susceptible host.}, language = {en} } @phdthesis{May2013, author = {May, Felix}, title = {Spatial models of plant diversity and plant functional traits : towards a better understanding of plant community dynamics in fragmented landscapes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-68444}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {The fragmentation of natural habitat caused by anthropogenic land use changes is one of the main drivers of the current rapid loss of biodiversity. In face of this threat, ecological research needs to provide predictions of communities' responses to fragmentation as a prerequisite for the effective mitigation of further biodiversity loss. However, predictions of communities' responses to fragmentation require a thorough understanding of ecological processes, such as species dispersal and persistence. Therefore, this thesis seeks an improved understanding of community dynamics in fragmented landscapes. In order to approach this overall aim, I identified key questions on the response of plant diversity and plant functional traits to variations in species' dispersal capability, habitat fragmentation and local environmental conditions. All questions were addressed using spatially explicit simulations or statistical models. In chapter 2, I addressed scale-dependent relationships between dispersal capability and species diversity using a grid-based neutral model. I found that the ratio of survey area to landscape size is an important determinant of scale-dependent dispersal-diversity relationships. With small ratios, the model predicted increasing dispersal-diversity relationships, while decreasing dispersal-diversity relationships emerged, when the ratio approached one, i.e. when the survey area approached the landscape size. For intermediate ratios, I found a U-shaped pattern that has not been reported before. With this study, I unified and extended previous work on dispersal-diversity relationships. In chapter 3, I assessed the type of regional plant community dynamics for the study area in the Southern Judean Lowlands (SJL). For this purpose, I parameterised a multi-species incidence-function model (IFM) with vegetation data using approximate Bayesian computation (ABC). I found that the type of regional plant community dynamics in the SJL is best characterized as a set of isolated "island communities" with very low connectivity between local communities. Model predictions indicated a significant extinction debt with 33\% - 60\% of all species going extinct within 1000 years. In general, this study introduces a novel approach for combining a spatially explicit simulation model with field data from species-rich communities. In chapter 4, I first analysed, if plant functional traits in the SJL indicate trait convergence by habitat filtering and trait divergence by interspecific competition, as predicted by community assembly theory. Second, I assessed the interactive effects of fragmentation and the south-north precipitation gradient in the SJL on community-mean plant traits. I found clear evidence for trait convergence, but the evidence for trait divergence fundamentally depended on the chosen null-model. All community-mean traits were significantly associated with the precipitation gradient in the SJL. The trait associations with fragmentation indices (patch size and connectivity) were generally weaker, but statistically significant for all traits. Specific leaf area (SLA) and plant height were consistently associated with fragmentation indices along the precipitation gradient. In contrast, seed mass and seed number were interactively influenced by fragmentation and precipitation. In general, this study provides the first analysis of the interactive effects of climate and fragmentation on plant functional traits. Overall, I conclude that the spatially explicit perspective adopted in this thesis is crucial for a thorough understanding of plant community dynamics in fragmented landscapes. The finding of contrasting responses of local diversity to variations in dispersal capability stresses the importance of considering the diversity and composition of the metacommunity, prior to implementing conservation measures that aim at increased habitat connectivity. The model predictions derived with the IFM highlight the importance of additional natural habitat for the mitigation of future species extinctions. In general, the approach of combining a spatially explicit IFM with extensive species occupancy data provides a novel and promising tool to assess the consequences of different management scenarios. The analysis of plant functional traits in the SJL points to important knowledge gaps in community assembly theory with respect to the simultaneous consequences of habitat filtering and competition. In particular, it demonstrates the importance of investigating the synergistic consequences of fragmentation, climate change and land use change on plant communities. I suggest that the integration of plant functional traits and of species interactions into spatially explicit, dynamic simulation models offers a promising approach, which will further improve our understanding of plant communities and our ability to predict their dynamics in fragmented and changing landscapes.}, language = {en} } @phdthesis{Abdelfadil2013, author = {Abdelfadil, Khaled Mohamed}, title = {Geochemistry of Variscan lamprophyre magmatism in the Saxo-Thuringian Zone}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-68854}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Lamprophyres are mantle-derived magmatic rocks, commonly occurring as dikes. They are readily identified from their field setting, petrography, chemical and mineralogical composition. These rocks not only provide important information on melting processes in the mantle, but also on geodynamic processes modifying the mantle. There are numerous occurrences of lamprophyres in the Saxo-Thuringian Zone of Variscan Central Europe, which are useful to track the variable effects of the Variscan orogeny on local mantle evolution. This work presents and evaluates the mineralogical, geochemical, and Sr-Nd-Pb isotopic data of late-Variscan calc-alkaline lamprophyres, post-Variscan ultramafic lamprophyres, of alkaline basalt from Lusatia, and, for comparison, of pre-Variscan gabbros. In addition, lithium isotopic signatures combined with Sr-Nd-Pb isotopic data of late-Variscan calc-alkaline lamprophyres from three different Variscan Domains (i.e., Erzgebirge, Lusatia, and Sudetes) are used to assess compositional changes of the mantle during Variscan orogeny.}, language = {de} } @phdthesis{Tyrallova2013, author = {Tyrallov{\´a}, Lucia}, title = {Automatisierte Objektidentifikation und Visualisierung terrestrischer Oberfl{\"a}chenformen}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69268}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Die automatisierte Objektidentifikation stellt ein modernes Werkzeug in den Geoinformationswissenschaften dar (BLASCHKE et al., 2012). Um bei thematischen Kartierungen untereinander vergleichbare Ergebnisse zu erzielen, sollen aus Sicht der Geoinformatik Mittel f{\"u}r die Objektidentifikation eingesetzt werden. Anstelle von Feldarbeit werden deshalb in der vorliegenden Arbeit multispektrale Fernerkundungsdaten als Prim{\"a}rdaten verwendet. Konkrete nat{\"u}rliche Objekte werden GIS-gest{\"u}tzt und automatisiert {\"u}ber große Fl{\"a}chen und Objektdichten aus Prim{\"a}rdaten identifiziert und charakterisiert. Im Rahmen der vorliegenden Arbeit wird eine automatisierte Prozesskette zur Objektidentifikation konzipiert. Es werden neue Ans{\"a}tze und Konzepte der objektbasierten Identifikation von nat{\"u}rlichen isolierten terrestrischen Oberfl{\"a}chenformen entwickelt und implementiert. Die Prozesskette basiert auf einem Konzept, das auf einem generischen Ansatz f{\"u}r automatisierte Objektidentifikation aufgebaut ist. Die Prozesskette kann anhand charakteristischer quantitativer Parameter angepasst und so umgesetzt werden, womit das Konzept der Objektidentifikation modular und skalierbar wird. Die modulbasierte Architektur erm{\"o}glicht den Einsatz sowohl einzelner Module als auch ihrer Kombination und m{\"o}glicher Erweiterungen. Die eingesetzte Methodik der Objektidentifikation und die daran anschließende Charakteristik der (geo)morphometrischen und morphologischen Parameter wird durch statistische Verfahren gest{\"u}tzt. Diese erm{\"o}glichen die Vergleichbarkeit von Objektparametern aus unterschiedlichen Stichproben. Mit Hilfe der Regressionsund Varianzanalyse werden Verh{\"a}ltnisse zwischen Objektparametern untersucht. Es werden funktionale Abh{\"a}ngigkeiten der Parameter analysiert, um die Objekte qualitativ zu beschreiben. Damit ist es m{\"o}glich, automatisiert berechnete Maße und Indizes der Objekte als quantitative Daten und Informationen zu erfassen und unterschiedliche Stichproben anzuwenden. Im Rahmen dieser Arbeit bilden Thermokarstseen die Grundlage f{\"u}r die Entwicklungen und als Beispiel sowie Datengrundlage f{\"u}r den Aufbau des Algorithmus und die Analyse. Die Geovisualisierung der multivariaten nat{\"u}rlichen Objekte wird f{\"u}r die Entwicklung eines besseren Verst{\"a}ndnisses der r{\"a}umlichen Relationen der Objekte eingesetzt. Kern der Geovisualisierung ist das Verkn{\"u}pfen von Visualisierungsmethoden mit karten{\"a}hnlichen Darstellungen.}, language = {de} } @phdthesis{Reilich2013, author = {Reilich, Julia}, title = {Bildungsrenditen in Deutschland}, series = {Potsdamer Schriften zur Raumwirtschaft}, journal = {Potsdamer Schriften zur Raumwirtschaft}, number = {5}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-219-3}, issn = {2190-8702}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-62658}, school = {Universit{\"a}t Potsdam}, pages = {xxiv, 244}, year = {2013}, abstract = {Der Einfluss von Bildung gewinnt gesellschaftlich und politisch an Bedeutung. Auch im wissenschaftlichen Bereich zeigt sich dies {\"u}ber eine vielseitige Diskussion zum Einfluss von Bildung auf das Einkommen. In dieser Arbeit werden nationale und regionale Disparit{\"a}ten in der monet{\"a}ren Wertsch{\"a}tzung von allgemeinem Humankapital aufgedeckt und diskutiert. Daf{\"u}r werden verschiedene Verfahren diskutiert und basierend darauf Intervalle f{\"u}r die mittleren Bildungsrenditen bestimmt. Im ersten Abschnitt wird die Thematik theoretisch {\"u}ber zwei verschiedene Modellans{\"a}tze fundiert und kritisch diskutiert. Anschließend folgt die Darstellung des aktuellen empirischen Forschungsbestands. Der Hauptteil der Arbeit beginnt mit der Darstellung des verwendeten Datensatzes und seiner kritischen Repr{\"a}sentativit{\"a}tspr{\"u}fung. Eine n{\"a}here Variablenbeschreibung mit deskriptiver Analyse dient zur Erkl{\"a}rung der verwendeten Gr{\"o}ßen. Darauffolgend werden bestehende Verfahren zur Sch{\"a}tzung von Bildungsrenditen diskutiert. Unter ausschließlicher Ber{\"u}cksichtigung der Erwerbst{\"a}tigen zeigt das 3SLS-Verfahren die besten Eigenschaften. Bezieht man jedoch alle Erwerbspersonen in die Analyse mit ein, so erweist sich das Heckman-Verfahren als sehr geeignet. Die Analyse - zun{\"a}chst auf nationaler Ebene - best{\"a}tigt weitestgehend die bestehenden Erkenntnisse der Literatur. Eine Separierung des Datensatzes auf verschiedene Alterscluster, Voll- und Teilerwerbst{\"a}tige sowie Erwerbst{\"a}tige in der Privatwirtschaft und im {\"o}ffentlichen Dienst zeigen keine signifikanten Unterschiede in der H{\"o}he der gezahlten durchschnittlichen Bildungsrenditen. Anders verh{\"a}lt es sich bei der regionalen Analyse. Zun{\"a}chst werden Ost- und Westdeutschland separat betrachtet. F{\"u}r diese erste Analyse lassen sich {\"u}ber 95 \%-Konfidenzintervalle deutliche Unterschiede in der H{\"o}he der Bildungsrenditen ermitteln. Aufbauend auf diese Ergebnisse wird die Analyse vertieft. Eine Separierung auf Bundesl{\"a}nderebene und ein weiterer Vergleich der Konfidenzintervalle folgen. Zur besseren statistischen Vergleichbarkeit der Ergebnisse wird neben dem 3SLS-Verfahren, angewendet auf die separierten Datens{\"a}tze, auch ein Modell ohne die Notwendigkeit der Separierung gew{\"a}hlt. Hierbei ist die Variation der Regionen {\"u}ber Interaktionsterme ber{\"u}cksichtigt. Dieses Regressionsmodell wird auf das OLS- und das Heckman-Verfahren angewendet. Der Vorteil hierbei ist, dass die Koeffizienten auf Gleichheit getestet werden k{\"o}nnen. Dabei kristallisieren sich deutlich unterschiedliche Bildungsrenditen f{\"u}r Mecklenburg-Vorpommern, aber auch f{\"u}r Sachsen-Anhalt und Th{\"u}ringen im Vergleich zu den restlichen Bundesl{\"a}ndern Deutschlands heraus. Diese L{\"a}nder zeichnen sich durch eine besonders hohe j{\"a}hrliche Verzinsung von allgemeinem Humankapital aus. Es folgt eine Diskussion {\"u}ber m{\"o}gliche Ursachen f{\"u}r die regional verschiedenen Bildungsrenditen. Dabei zeigt sich, dass in den Bundesl{\"a}ndern mit hoher Rendite das mittlere Einkommensniveau und auch das durchschnittliche Preisniveau tendenziell geringer sind. Weiterhin wird deutlich, dass bei h{\"o}heren relativen Abweichungen der durchschnittlichen Einkommen h{\"o}here Renditen zu verzeichnen sind. Auch die Wanderungsbewegungen je nach Qualifikation unterscheiden sich. Unter zus{\"a}tzlicher Ber{\"u}cksichtigung der Arbeitslosenquoten zeigt sich in den L{\"a}ndern mit hoher Rendite eine tendenziell h{\"o}here Arbeitslosigkeit. Im zusammenfassenden Fazit der Arbeit werden abschließend die Erkenntnisse gew{\"u}rdigt. Dabei ist zu bemerken, dass der Beitrag einen Start in die bundesl{\"a}nderweite Analyse liefert, die eine Fortf{\"u}hrung auf beispielsweise eine mehrperiodische Betrachtung anregt.}, language = {de} } @phdthesis{Bauckmann2013, author = {Bauckmann, Jana}, title = {Dependency discovery for data integration}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-66645}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Data integration aims to combine data of different sources and to provide users with a unified view on these data. This task is as challenging as valuable. In this thesis we propose algorithms for dependency discovery to provide necessary information for data integration. We focus on inclusion dependencies (INDs) in general and a special form named conditional inclusion dependencies (CINDs): (i) INDs enable the discovery of structure in a given schema. (ii) INDs and CINDs support the discovery of cross-references or links between schemas. An IND "A in B" simply states that all values of attribute A are included in the set of values of attribute B. We propose an algorithm that discovers all inclusion dependencies in a relational data source. The challenge of this task is the complexity of testing all attribute pairs and further of comparing all of each attribute pair's values. The complexity of existing approaches depends on the number of attribute pairs, while ours depends only on the number of attributes. Thus, our algorithm enables to profile entirely unknown data sources with large schemas by discovering all INDs. Further, we provide an approach to extract foreign keys from the identified INDs. We extend our IND discovery algorithm to also find three special types of INDs: (i) Composite INDs, such as "AB in CD", (ii) approximate INDs that allow a certain amount of values of A to be not included in B, and (iii) prefix and suffix INDs that represent special cross-references between schemas. Conditional inclusion dependencies are inclusion dependencies with a limited scope defined by conditions over several attributes. Only the matching part of the instance must adhere the dependency. We generalize the definition of CINDs distinguishing covering and completeness conditions and define quality measures for conditions. We propose efficient algorithms that identify covering and completeness conditions conforming to given quality thresholds. The challenge for this task is twofold: (i) Which (and how many) attributes should be used for the conditions? (ii) Which attribute values should be chosen for the conditions? Previous approaches rely on pre-selected condition attributes or can only discover conditions applying to quality thresholds of 100\%. Our approaches were motivated by two application domains: data integration in the life sciences and link discovery for linked open data. We show the efficiency and the benefits of our approaches for use cases in these domains.}, language = {en} } @phdthesis{Thalmann2013, author = {Thalmann, Sophie}, title = {Korrelation zwischen der genetischen und der funktionellen Diversit{\"a}t humaner Bitterrezeptoren}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-66845}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Der Mensch besitzt ~25 funktionelle Bitterrezeptoren (TAS2R), die f{\"u}r die Wahrnehmung potenziell toxischer Substanzen in der Nahrung verantwortlich sind. Aufgrund der großen genetischen Variabilit{\"a}t der TAS2R-Gene k{\"o}nnte es eine Vielzahl funktionell unterschiedlicher TAS2R-Haplotypen geben, die zu Unterschieden der Bitterwahrnehmung f{\"u}hren. Dies konnte bereits in funktionellen Analysen und sensorischen Studien f{\"u}r einzelne Bitterrezeptoren gezeigt werden. In dieser Arbeit wurden die h{\"a}ufigsten Haplotypen aller 25 Bitterrezeptoren verschiedener Ethnien funktionell charakterisiert. Das Ziel war eine umfassende Aussage {\"u}ber die funktionelle Diversit{\"a}t der TAS2Rs, die die molekulare Grundlage f{\"u}r individuelle Bitterwahrnehmung bildet, treffen zu k{\"o}nnen. Fehlende Varianten wurden aus genomischer DNA kloniert oder durch gezielte Mutagenese bereits vorhandener TAS2R-Konstrukte generiert. Die funktionelle Analyse erfolgte mittels Expression der TAS2R-Haplotypen in HEK293TG16gust44 Zellen und anschließenden Calcium-Imaging-Experimenten mit zwei bekannten Agonisten. Die Haplotypen der f{\"u}nf orphanen TAS2Rs wurden mit {\"u}ber hundert Bitterstoffen stimuliert. Durch die gelungene Deorphanisierung des TAS2R41 in dieser Arbeit, wurden f{\"u}r die 21 aktivierbaren TAS2Rs 36 funktionell-unterschiedliche Haplotypen identifiziert. Die tats{\"a}chliche funktionelle Vielfalt blieb jedoch deutlich hinter der genetischen Variabilit{\"a}t der TAS2Rs zur{\"u}ck. Neun Bitterrezeptoren wiesen funktionell homogene Haplotypen auf oder besaßen nur eine weltweit vorherrschende Variante. Funktionell heterogene Haplotypen wurden f{\"u}r zw{\"o}lf TAS2Rs identifiziert. Inaktive Varianten der Rezeptoren TAS2R9, TAS2R38 und TAS2R46 sollten die Wahrnehmung von Bitterstoffen wie Ofloxacin, Cnicin, Hydrocortison, Limonin, Parthenolid oder Strychnin beeinflussen. Unterschiedlich sensitive Varianten, besonders der Rezeptoren TAS2R47 und TAS2R49, sollten f{\"u}r Agonisten wie Absinthin, Amarogentin oder Cromolyn ebenfalls zu ph{\"a}notypischen Unterschieden f{\"u}hren. Wie f{\"u}r den TAS2R16 bereits gezeigt, traten Haplotypen des funktionell heterogenen TAS2R7 und TAS2R41 ethnien-spezifisch auf, was auf lokale Anpassung und verschiedene Ph{\"a}notypen hinweisen k{\"o}nnte. Weiterf{\"u}hrend muss nun eine Analyse der funktionell-variablen TAS2Rs in sensorischen Tests erfolgen, um ihre ph{\"a}notypische Relevanz zu pr{\"u}fen. Die Analyse der funktionsmodulierenden Aminos{\"a}urepositionen, z.Bsp. des TAS2R44, TAS2R47 oder TAS2R49, k{\"o}nnte weiterf{\"u}hrend zum besseren Verst{\"a}ndnis der Rezeptor-Ligand- und Rezeptor-G-Protein-Interaktion beitragen.}, language = {de} } @phdthesis{Jahnke2013, author = {Jahnke, D{\"o}rte}, title = {Gest{\"o}rtes Essverhalten im familialen Kontext : Welche Rolle spielen m{\"u}tterliche gewichts- und essst{\"o}rungsrelevante Merkmale bei der Auspr{\"a}gung gest{\"o}rten Essverhaltens im Kindesalter?}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-65145}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Gewichts- und essst{\"o}rungsrelevante Auff{\"a}lligkeiten sind bereits im Kindesalter verbreitet. Neben genetischen Faktoren kommt auch die familiale Vermittlung gest{\"o}rten Essverhaltens als Genesefaktor in Betracht. Ab dem Alter von zehn Jahren gibt es eine breite empirische Basis f{\"u}r die Verkn{\"u}pfung gest{\"o}rten Essverhaltens zwischen M{\"u}ttern und ihren Kindern. F{\"u}r das Alter unter zehn Jahren existiert bislang wenig gesichertes Wissen. Die Erforschung der spezifischen Wirkung des m{\"u}tterlichen auf kindliches gest{\"o}rtes Essverhalten ist jedoch im Hinblick auf Ans{\"a}tze zur Pr{\"a}vention kindlicher Gewichts- und Essst{\"o}rungen f{\"u}r dieses Alter von Bedeutung. Im Rahmen der vorliegenden Arbeit wurde gest{\"o}rtes Essverhalten von M{\"u}ttern und Kindern im Alter zwischen einem und zehn Jahren sowie die Beziehung gest{\"o}rten Essverhaltens von M{\"u}ttern und ihren Kindern in zwei Studien analysiert. Die erste Studie verfolgte das Ziel, gest{\"o}rtes Essverhalten von M{\"u}ttern und Kindern sowie deren Beziehung im Kontext m{\"u}tterlichen {\"U}bergewichts zu analysieren. Es wurden 219 M{\"u}tter von Kindern im Alter von drei bis sechs Jahren befragt. In der zweiten Studie wurde neben m{\"u}tterlichem {\"U}bergewicht die Rolle m{\"u}tterlicher Essst{\"o}rungssymptomatik fokussiert und in den Analysen des gest{\"o}rten Essverhaltens von Kindern im Alter von einem bis zehn Jahren ber{\"u}cksichtigt. In die Untersuchung ging eine Stichprobe von 506 M{\"u}ttern und deren Kindern ein. In beiden Studien beantworteten M{\"u}tter ein Fragebogenpaket, welches Instrumente zum gest{\"o}rten Essverhalten der M{\"u}tter (emotionales, externales und gez{\"u}geltes Essverhalten) und gest{\"o}rten Essverhalten des Kindes (emotionales und externales Essverhalten sowie Verlangen nach Essen) umfasste. In der zweiten Studie wurden dar{\"u}ber hinaus Prim{\"a}rsymptomatik einer Essst{\"o}rung der Mutter (Schlankheitsstreben, K{\"o}rperunzufriedenheit und bulimisches Essverhalten) und pathologisches Essverhalten der Kinder erfragt. {\"U}bergewichtige M{\"u}tter berichteten nicht nur h{\"o}here Auspr{\"a}gungen emotionalen und externalen Essverhaltens, sondern auch mehr Schlankheitsstreben, K{\"o}rperunzufriedenheit und bulimisches Essverhalten als normal- und untergewichtige M{\"u}tter. Insgesamt 26\% der befragten M{\"u}tter der zweiten Studie berichteten eine relevante Essst{\"o}rungssymptomatik, davon waren 62\% {\"u}bergewichtig. F{\"u}r die Kinder konnten keine Geschlechtsunterschiede hinsichtlich des Essverhaltens nachgewiesen werden. Im Grundschulalter waren emotionales und pathologisches Essverhalten h{\"o}her ausgepr{\"a}gt als bei j{\"u}ngeren Kindern. Kindliches {\"U}bergewicht war mit mehr emotionalem und externalem Essverhalten, Verlangen nach Essen sowie pathologischem Essverhalten verbunden. Das Vorliegen m{\"u}tterlichen {\"U}bergewichts sowie einer m{\"u}tterlichen Essst{\"o}rungssymptomatik war mit h{\"o}heren Auspr{\"a}gungen v.a. emotionalen Essverhaltens des Kindes assoziiert. Die h{\"o}chsten Auspr{\"a}gungen emotionalen Essverhaltens zeigten Kinder, deren M{\"u}tter {\"U}bergewicht und eine komorbide Essst{\"o}rungssymptomatik berichtet hatten. Dar{\"u}ber hinaus leisteten gest{\"o}rte Essverhaltensweisen der Mutter {\"u}ber allgemeine und gewichtsspezifische Aspekte hinaus einen relevanten Beitrag zur Varianzaufkl{\"a}rung emotionalen und externalen Essverhaltens des Kindes. Dabei war emotionales und externales Essverhalten von Mutter und Kind spezifisch miteinander verkn{\"u}pft. In der ersten Studie ließ sich im Rahmen eines Mediatormodells zeigen, dass die Beziehung zwischen m{\"u}tterlichem BMI und emotionalem Essverhalten des Kindes vollst{\"a}ndig durch das emotionale Essverhalten der Mutter vermittelt wurde. In der zweiten Studie moderierte das Alter des Kindes die Beziehung zwischen emotionalem Essverhalten von M{\"u}ttern und ihren Kindern in Richtung einer signifikanten Assoziation ab dem Alter von 5,4 Jahren des Kindes. Die vorliegende Arbeit liefert deutliche Hinweise auf die Verkn{\"u}pfung zwischen m{\"u}tterlichen gewichts- und essst{\"o}rungsrelevanten Merkmalen und kindlichem gest{\"o}rtem Essverhalten. Die Befunde legen nahe, dass emotionales Essverhalten als spezifischer {\"U}bertragungsweg gewichts- und essbezogener St{\"o}rungen zwischen M{\"u}ttern und Kindern in Betracht kommt und in Pr{\"a}ventionsans{\"a}tzen ber{\"u}cksichtigt werden sollte.}, language = {de} } @phdthesis{Kussmaul2013, author = {Kussmaul, Bj{\"o}rn}, title = {Modifizierung von Silikonelastomeren mit organischen Dipolen f{\"u}r Dielektrische Elastomer Aktuatoren}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-65121}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Ein Dielektrischer Elastomer Aktuator (DEA) ist ein dehnbarer Kondensator, der aus einem Elastomerfilm besteht, der sich zwischen zwei flexiblen Elektroden befindet. Bei Anlegen einer elektrischen Spannung, ziehen sich die Elektroden aufgrund elektrostatischer Wechselwirkungen an, wodurch das Elastomer in z-Richtung zusammengepresst wird und sich dementsprechend in der x-,y-Ebene ausdehnt. Hierdurch werden Aktuationsbewegungen erreicht, welche sehr pr{\"a}zise {\"u}ber die Spannung gesteuert werden k{\"o}nnen. Zus{\"a}tzlich sind DEAs kosteng{\"u}nstig, leicht und aktuieren ger{\"a}uschlos. DEAs k{\"o}nnen beispielsweise f{\"u}r Produkte im medizinischen Bereich oder f{\"u}r optischer Komponenten genutzt werden. Ebenso kann aus diesen Bauteilen Strom erzeugt werden. Das gr{\"o}ßte Hindernis f{\"u}r eine weite Implementierung dieser Materialien liegt in den erforderlichen hohen Spannungen zum Erzeugen der Aktuationsbewegung, welche sich tendenziell im Kilovolt-Bereich befinden. Dies macht die Elektronik teuer und die Bauteile unsicher f{\"u}r Anwender. Um geringere Betriebsspannungen f{\"u}r die DEAs zu erreichen, sind signifikante Materialverbesserungen - insbesondere des verwendeten Elastomers - erforderlich. Um dies zu erreichen, k{\"o}nnen die dielektrischen Eigenschaften (Permittivit{\"a}t) der Elastomere gesteigert und/oder deren Steifigkeit (Young-Modul) gesenkt werden. In der vorliegenden Arbeit konnte die Aktuationsleistung von Silikonfilmen durch die Addition organischer Dipole erheblich verbessert werden. Hierf{\"u}r wurde ein Verfahren etabliert, um funktionalisierte Dipole kovalent an das Polymernetzwerk zu binden. Dieser als "One-Step-Verfahren" bezeichnete Ansatz ist einfach durchzuf{\"u}hren und es werden homogene Filme erhalten. Die Dipoladdition wurde anhand verschiedener Silikone erprobt, die sich hinsichtlich ihrer mechanischen Eigenschaften unterschieden. Bei maximalem Dipolgehalt verdoppelte sich die Permittivit{\"a}t aller untersuchten Silikone und die Filme wurden deutlich weicher. Hierbei war festzustellen, dass die Netzwerkstruktur der verwendeten Silikone einen erheblichen Einfluss auf die erreichte Aktuationsdehnung hat. Abh{\"a}ngig vom Netzwerk erfolgte eine enorme Steigerung der Aktuationsleistung im Bereich von 100 \% bis zu 4000 \%. Dadurch k{\"o}nnen die Betriebsspannungen in DEAs deutlich abgesenkt werden, so dass sie tendenziell bei Spannungen unterhalb von einem Kilovolt betrieben werden k{\"o}nnen.}, language = {de} } @phdthesis{Helfert2013, author = {Helfert, Susanne}, title = {Die Rolle aussehensbezogenen sozialen Drucks in der Entstehung von K{\"o}rperunzufriedenheit im Jugendalter}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-66946}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {K{\"o}rperliche Attraktivit{\"a}t und gutes Aussehen spielen in der heutigen Gesellschaft eine entscheidende Rolle, was bereits fr{\"u}hzeitig auch Kinder und Jugendliche in ihren Einstellungen und der Wahrnehmung ihres K{\"o}rpers pr{\"a}gt. Sorgen um den eigenen K{\"o}rper gelten als normatives Problem unter Jugendlichen und bergen nicht selten das Risiko f{\"u}r gesundheitsgef{\"a}hrdendes Verhalten und psychische Erkrankungen. In der Suche nach den Ursachen gerieten in den letzten Jahren insbesondere soziokulturelle Faktoren, insbesondere der Einfluss von medial vermittelten Sch{\"o}nheitsidealen, in den Fokus der Forschung. Es ist jedoch fraglich, warum nicht alle Jugendlichen in gleicher Weise auf den allgegenw{\"a}rtigen Mediendruck reagieren. Naheliegend ist, dass die Jugendlichen besonders gef{\"a}hrdet sind, deren unmittelbares soziales Umfeld das geltende Sch{\"o}nheitsideal direkt oder indirekt vermittelt und verst{\"a}rkt. Das Verst{\"a}ndnis der Rolle sozialen Drucks ist jedoch bislang noch durch zahlreiche inhaltliche und methodische Aspekte beschr{\"a}nkt (z.B. Einschr{\"a}nkungen in der Operationalisierung, ungen{\"u}gende Ber{\"u}cksichtigung geschlechtsspezifischer Mechanismen, fehlende l{\"a}ngsschnittliche Belege). Daher widmet sich die vorliegende Arbeit der Bedeutung aussehensbezogenen sozialen Drucks in der Entstehung von K{\"o}rperunzufriedenheit im Jugendalter in drei aufeinander aufbauenden Untersuchungsschritten. Ausgehend von der Entwicklung eines umfassenden und zuverl{\"a}ssigen Erhebungsinstruments zielt die Arbeit darauf ab, unterschiedliche Aspekte sozialen Drucks gegen{\"u}berzustellen und hinsichtlich ihrer Verbreitung und Risikowirkung zu vergleichen. Die Umsetzung des Forschungsvorhabens erfolgte in unterschiedlichen Sch{\"u}lerstichproben der Klassen 7 bis 9 unterschiedlicher Gymnasien und Gesamtschulen (Hauptstichprobe N = 1112, im Mittel = 13.4 ± 0.8 Jahre). Dabei wurden sowohl quer- als auch l{\"a}ngsschnittliche Analysen durchgef{\"u}hrt. Zus{\"a}tzlich wurden zur Erprobung des Fragebogenverfahrens klinische Stichproben mit Ess- und Gewichtsst{\"o}rungen herangezogen. Zur detaillierten Erfassung unterschiedlicher Formen aussehensbezogenen sozialen Drucks erfolgte im ersten Schritt die Entwicklung des Fragebogen zum aussehensbezogen sozialen Druck (FASD), welcher acht unterschiedliche Formen aussehensbezogene sozialen Drucks ausgehend von Eltern und Gleichaltrigen reliabel und valide erfasst. Dabei erwies sich das Verfahren gleichermaßen f{\"u}r Jungen und M{\"a}dchen, wie f{\"u}r Jugendliche mit unterschiedlichem Gewichtsstatus geeignet. Die psychometrische G{\"u}te des Verfahrens konnte sowohl f{\"u}r populationsbasierte als auch f{\"u}r klinische Stichproben mit Ess- und Gewichtsst{\"o}rung belegt werden, wodurch eine breite Einsatzm{\"o}glichkeit in Forschung und Praxis denkbar ist. Im zweiten Schritt erfolgte die Untersuchung der Verbreitung aussehensbezogenen sozialen Drucks unter besonderer Ber{\"u}cksichtigung von Geschlechts-, Alters- und Gewichtsgruppenunterschieden. Dabei erwiesen sich M{\"a}dchen als st{\"a}rker von aussehensbezogenem Druck durch Gleichaltrige betroffen als Jungen. Dar{\"u}berhinaus legen die Ergebnisse nahe, dass {\"U}bergewicht ungeachtet des Geschlechts mit verst{\"a}rkten aussehensbezogenen Abwertungen und Ausgrenzungserfahrungen verbunden ist. Zudem deuten die Alterseffekte der Studie darauf hin, dass der {\"U}bergang von fr{\"u}her zu mittlerer Adoleszenz aber auch Schulwechsel besonderes kritische Zeitpunkte f{\"u}r die Etablierung aussehensbezogener Einfl{\"u}sse darstellen. Abschließend widmete sich die Arbeit der l{\"a}ngsschnittlichen Risikowirkung unterschiedlicher Aspekte aussehensbezogenen sozialen Drucks in der Entstehung von K{\"o}rperunzufriedenheit. Aussehensbezogene Einfl{\"u}sse von Freunden verst{\"a}rkten l{\"a}ngsschnittlich K{\"o}rpersorgen sowohl bei M{\"a}dchen als auch bei Jungen. Zudem ergab sich das Erleben von Ausgrenzung durch Gleichaltrige als entscheidender Risikofaktor f{\"u}r gewichtsbezogene K{\"o}rpersorgen unter Jungen. Als bedeutsamster elterlicher Einfluss erwiesen sich Aufforderungen auf die Figur zu achten. Diese Aufforderungen verst{\"a}rkten gleichermaßen f{\"u}r M{\"a}dchen und Jungen gewichtsbezogene K{\"o}rpersorgen. Die vorliegende Arbeit widmete sich dem Ziel, die Rolle aussehensbezogener sozialer Einfl{\"u}sse weiter aufzukl{\"a}ren. Das dazu vorgelegte umfassende Instrument erm{\"o}glichte eine differenzierte Betrachtung der Verbreitung und Wirkung unterschiedlicher Formen sozialen Drucks. Hierdurch weisen die Ergebnisse nicht nur auf wichtige geschlechtsspezifische Mechanismen hin, sondern leisten ebenso einen Beitrag zum vertieften Verst{\"a}ndnis der Risikowirkung sozialen Drucks. Diese Erkenntnisse liefern somit einerseits konkrete Ansatzpunkte f{\"u}r Pr{\"a}vention und Intervention und erm{\"o}glichen andererseits auch eine weitere Konkretisierung bereits etablierter soziokultureller Wirkmodelle.}, language = {de} } @phdthesis{Mueller2013, author = {M{\"u}ller, Mike-Freya}, title = {Die Glutathionperoxidase 2 : physiologische Funktion und Rolle in der Azoxymethan-induzierten Colonkanzerogenese}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-66955}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Das Selenoprotein Glutathionperoxidase 2 (GPx2) ist ein epithelzellspezifisches, Hydroperoxide-reduzierendes Enzym, welches im Darmepithel, vor allem in den proliferierenden Zellen des Kryptengrundes, exprimiert wird. Die Aufrechterhaltung der GPx2-Expression im Kryptengrund auch bei subad{\"a}quatem Selenstatus k{\"o}nnte darauf hinweisen, dass sie hier besonders wichtige Funktionen wahrnimmt. Tats{\"a}chlich weisen GPx2 knockout (KO)-M{\"a}use eine erh{\"o}hte Apoptoserate im Kryptengrund auf. Ein Ziel dieser Arbeit war es deshalb, die physiologische Funktion der GPx2 n{\"a}her zu untersuchen. In Kryptengrundepithelzellen aus dem Colon selenarmer GPx2 KO-M{\"a}use wurde eine erh{\"o}hte Caspase 3/7-Aktivit{\"a}t im Vergleich zum Wildtyp (WT) festgestellt. Zudem wiesen diese Zellen eine erh{\"o}hte Suszeptibilit{\"a}t f{\"u}r oxidativen Stress auf. Die GPx2 gew{\"a}hrleistet also den Schutz der proliferierenden Zellen des Kryptengrundes auch bei subad{\"a}quater Selenversorgung. Des Weiteren wurde im Colon selenarmer (-Se) und -ad{\"a}quater (+Se) GPx2 KO-M{\"a}use im Vergleich zum WT eine erh{\"o}hte Tumornekrosefaktor α-Expression und eine erh{\"o}hte Infiltration von Makrophagen festgestellt. Durch F{\"u}tterung einer selensupplementierten Di{\"a}t (++Se) konnte dies verhindert werden. In GPx2 KO-M{\"a}usen liegt demnach bereits basal eine niedriggradige Entz{\"u}ndung vor. Dies unterstreicht, dass GPx2 vor allem eine wichtige antiinflammatorische Funktion im Darmepithel besitzt. Dem Mikron{\"a}hrstoff Selen werden protektive Funktionen in der Colonkanzerogenese zugeschrieben. In einem Mausmodell der Colitis-assoziierten Colonkanzerogenese wirkte GPx2 antiinflammatorisch und hemmte so die Tumorentstehung. Auf der anderen Seite wurden jedoch auch prokanzerogene Eigenschaften der GPx2 aufgedeckt. Deshalb sollte in dieser Arbeit untersucht werden, welchen Effekt ein GPx2 knockout in einem Modell der sporadischen, durch Azoxymethan (AOM) induzierten, Colonkanzerogenese hat. Im WT kam es in pr{\"a}neoplastischen L{\"a}sionen h{\"a}ufig zu einer erh{\"o}hten GPx2-Expression im Vergleich zur normalen Darmmucosa. Eine derartige Steigerung der GPx2-Expression wurde auch in der humanen Colonkanzerogenese beschrieben. Das Fehlen der GPx2 resultierte in einer verminderten Entstehung von Tumoren (-Se und ++Se) und pr{\"a}neoplastischen L{\"a}sionen (-Se und +Se). Somit f{\"o}rderte GPx2 die Tumorentstehung im AOM-Modell. Acht Stunden nach AOM-Gabe war im GPx2 KO-Colon im Vergleich zum WT eine erh{\"o}hte Apoptoserate in der Kryptenmitte (-Se, +Se), nicht jedoch im Kryptengrund oder in der ++Se-Gruppe zu beobachten. M{\"o}glicherweise wirkte GPx2 prokanzerogen, indem sie die effiziente Elimination gesch{\"a}digter Zellen in der Tumorinitiationsphase verhinderte. Eine {\"a}hnliche Wirkung w{\"a}re auch durch die erh{\"o}hte GPx2-Expression in der Promotionsphase denkbar. So k{\"o}nnte GPx2 proliferierende pr{\"a}neoplastische Zellen vor oxidativem Stress, Apoptosen, oder auch der Antitumorimmunit{\"a}t sch{\"u}tzen. Dies k{\"o}nnte durch ein Zusammenwirken mit anderen Selenoproteinen wie GPx1 und Thioredoxinreduktasen, f{\"u}r die ebenfalls auch prokanzerogene Funktionen beschrieben wurden, verst{\"a}rkt werden. Eine wichtige Rolle k{\"o}nnte hier die Modulation des Redoxstatus in Tumorzellen spielen. Die Variation des Selengehalts der Di{\"a}t hatte im WT einen eher U-f{\"o}rmigen Effekt. So traten in der -Se und ++Se-Gruppe tendenziell mehr und gr{\"o}ßere Tumore auf, als in der +Se Gruppe. Zusammenfassend sch{\"u}tzt GPx2 also die proliferierenden Zellen des Kryptengrundes. Sie k{\"o}nnte jedoch auch proliferierende transformierte Zellen sch{\"u}tzen und so die sporadische, AOM-induzierte Colonkanzerogenese f{\"o}rdern. In einem Modell der Colitis-assoziierten Colonkanzerogenese hatte GPx2 auf Grund ihrer antiinflammatorischen Wirkung einen gegenteiligen Effekt und hemmte die Tumorentstehung. Die Rolle der GPx2 in der Colonkanzerogenese ist also abh{\"a}ngig vom zugrunde liegenden Mechanismus und wird maßgeblich von der Beteiligung einer Entz{\"u}ndung bestimmt.}, language = {de} } @phdthesis{Buchhorn2013, author = {Buchhorn, Marcel}, title = {Ground-based hyperspectral and spectro-directional reflectance characterization of Arctic tundra vegetation communities : field spectroscopy and field spectro-goniometry of Siberian and Alaskan tundra in preparation of the EnMAP satellite mission}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70189}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {The Arctic tundra, covering approx. 5.5 \% of the Earth's land surface, is one of the last ecosystems remaining closest to its untouched condition. Remote sensing is able to provide information at regular time intervals and large spatial scales on the structure and function of Arctic ecosystems. But almost all natural surfaces reveal individual anisotropic reflectance behaviors, which can be described by the bidirectional reflectance distribution function (BRDF). This effect can cause significant changes in the measured surface reflectance depending on solar illumination and sensor viewing geometries. The aim of this thesis is the hyperspectral and spectro-directional reflectance characterization of important Arctic tundra vegetation communities at representative Siberian and Alaskan tundra sites as basis for the extraction of vegetation parameters, and the normalization of BRDF effects in off-nadir and multi-temporal remote sensing data. Moreover, in preparation for the upcoming German EnMAP (Environmental Mapping and Analysis Program) satellite mission, the understanding of BRDF effects in Arctic tundra is essential for the retrieval of high quality, consistent and therefore comparable datasets. The research in this doctoral thesis is based on field spectroscopic and field spectro-goniometric investigations of representative Siberian and Alaskan measurement grids. The first objective of this thesis was the development of a lightweight, transportable, and easily managed field spectro-goniometer system which nevertheless provides reliable spectro-directional data. I developed the Manual Transportable Instrument platform for ground-based Spectro-directional observations (ManTIS). The outcome of the field spectro-radiometrical measurements at the Low Arctic study sites along important environmental gradients (regional climate, soil pH, toposequence, and soil moisture) show that the different plant communities can be distinguished by their nadir-view reflectance spectra. The results especially reveal separation possibilities between the different tundra vegetation communities in the visible (VIS) blue and red wavelength regions. Additionally, the near-infrared (NIR) shoulder and NIR reflectance plateau, despite their relatively low values due to the low structure of tundra vegetation, are still valuable information sources and can separate communities according to their biomass and vegetation structure. In general, all different tundra plant communities show: (i) low maximum NIR reflectance; (ii) a weakly or nonexistent visible green reflectance peak in the VIS spectrum; (iii) a narrow "red-edge" region between the red and NIR wavelength regions; and (iv) no distinct NIR reflectance plateau. These common nadir-view reflectance characteristics are essential for the understanding of the variability of BRDF effects in Arctic tundra. None of the analyzed tundra communities showed an even closely isotropic reflectance behavior. In general, tundra vegetation communities: (i) usually show the highest BRDF effects in the solar principal plane; (ii) usually show the reflectance maximum in the backward viewing directions, and the reflectance minimum in the nadir to forward viewing directions; (iii) usually have a higher degree of reflectance anisotropy in the VIS wavelength region than in the NIR wavelength region; and (iv) show a more bowl-shaped reflectance distribution in longer wavelength bands (>700 nm). The results of the analysis of the influence of high sun zenith angles on the reflectance anisotropy show that with increasing sun zenith angles, the reflectance anisotropy changes to azimuthally symmetrical, bowl-shaped reflectance distributions with the lowest reflectance values in the nadir view position. The spectro-directional analyses also show that remote sensing products such as the NDVI or relative absorption depth products are strongly influenced by BRDF effects, and that the anisotropic characteristics of the remote sensing products can significantly differ from the observed BRDF effects in the original reflectance data. But the results further show that the NDVI can minimize view angle effects relative to the contrary spectro-directional effects in the red and NIR bands. For the researched tundra plant communities, the overall difference of the off-nadir NDVI values compared to the nadir value increases with increasing sensor viewing angles, but on average never exceeds 10 \%. In conclusion, this study shows that changes in the illumination-target-viewing geometry directly lead to an altering of the reflectance spectra of Arctic tundra communities according to their object-specific BRDFs. Since the different tundra communities show only small, but nonetheless significant differences in the surface reflectance, it is important to include spectro-directional reflectance characteristics in the algorithm development for remote sensing products.}, language = {en} } @phdthesis{Ohl2013, author = {Ohl, Sven}, title = {Small eye movements during fixation : the case of postsaccadic fixation and preparatory influences}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69862}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Describing human eye movement behavior as an alternating sequence of saccades and fixations turns out to be an oversimplification because the eyes continue to move during fixation. Small-amplitude saccades (e.g., microsaccades) are typically observed 1-2 times per second during fixation. Research on microsaccades came in two waves. Early studies on microsaccades were dominated by the question whether microsaccades affect visual perception, and by studies on the role of microsaccades in the process of fixation control. The lack of evidence for a unique role of microsaccades led to a very critical view on the importance of microsaccades. Over the last years, microsaccades moved into focus again, revealing many interactions with perception, oculomotor control and cognition, as well as intriguing new insights into the neurophysiological implementation of microsaccades. In contrast to early studies on microsaccades, recent findings on microsaccades were accompanied by the development of models of microsaccade generation. While the exact generating mechanisms vary between the models, they still share the assumption that microsaccades are generated in a topographically organized saccade motor map that includes a representation for small-amplitude saccades in the center of the map (with its neurophysiological implementation in the rostral pole of the superior colliculus). In the present thesis I criticize that models of microsaccade generation are exclusively based on results obtained during prolonged presaccadic fixation. I argue that microsaccades should also be studied in a more natural situation, namely the fixation following large saccadic eye movements. Studying postsaccadic fixation offers a new window to falsify models that aim to account for the generation of small eye movements. I demonstrate that error signals (visual and extra-retinal), as well as non-error signals like target eccentricity influence the characteristics of small-amplitude eye movements. These findings require a modification of a model introduced by Rolfs, Kliegl and Engbert (2008) in order to account for the generation of small-amplitude saccades during postsaccadic fixation. Moreover, I present a promising type of survival analysis that allowed me to examine time-dependent influences on postsaccadic eye movements. In addition, I examined the interplay of postsaccadic eye movements and postsaccadic location judgments, highlighting the need to include postsaccadic eye movements as covariate in the analyses of location judgments in the presented paradigm. In a second goal, I tested model predictions concerning preparatory influences on microsaccade generation during presaccadic fixation. The observation, that the preparatory set significantly influenced microsaccade rate, supports the critical model assumption that increased fixation-related activity results in a larger number of microsaccades. In the present thesis I present important influences on the generation of small-amplitude saccades during fixation. These eye movements constitute a rich oculomotor behavior which still poses many research questions. Certainly, small-amplitude saccades represent an interesting source of information and will continue to influence future studies on perception and cognition.}, language = {en} } @phdthesis{Becker2013, author = {Becker, Basil}, title = {Architectural modelling and verification of open service-oriented systems of systems}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70158}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Systems of Systems (SoS) have received a lot of attention recently. In this thesis we will focus on SoS that are built atop the techniques of Service-Oriented Architectures and thus combine the benefits and challenges of both paradigms. For this thesis we will understand SoS as ensembles of single autonomous systems that are integrated to a larger system, the SoS. The interesting fact about these systems is that the previously isolated systems are still maintained, improved and developed on their own. Structural dynamics is an issue in SoS, as at every point in time systems can join and leave the ensemble. This and the fact that the cooperation among the constituent systems is not necessarily observable means that we will consider these systems as open systems. Of course, the system has a clear boundary at each point in time, but this can only be identified by halting the complete SoS. However, halting a system of that size is practically impossible. Often SoS are combinations of software systems and physical systems. Hence a failure in the software system can have a serious physical impact what makes an SoS of this kind easily a safety-critical system. The contribution of this thesis is a modelling approach that extends OMG's SoaML and basically relies on collaborations and roles as an abstraction layer above the components. This will allow us to describe SoS at an architectural level. We will also give a formal semantics for our modelling approach which employs hybrid graph-transformation systems. The modelling approach is accompanied by a modular verification scheme that will be able to cope with the complexity constraints implied by the SoS' structural dynamics and size. Building such autonomous systems as SoS without evolution at the architectural level --- i. e. adding and removing of components and services --- is inadequate. Therefore our approach directly supports the modelling and verification of evolution.}, language = {en} } @phdthesis{Vogel2013, author = {Vogel, Kristin}, title = {Applications of Bayesian networks in natural hazard assessments}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69777}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Even though quite different in occurrence and consequences, from a modeling perspective many natural hazards share similar properties and challenges. Their complex nature as well as lacking knowledge about their driving forces and potential effects make their analysis demanding: uncertainty about the modeling framework, inaccurate or incomplete event observations and the intrinsic randomness of the natural phenomenon add up to different interacting layers of uncertainty, which require a careful handling. Nevertheless deterministic approaches are still widely used in natural hazard assessments, holding the risk of underestimating the hazard with disastrous effects. The all-round probabilistic framework of Bayesian networks constitutes an attractive alternative. In contrast to deterministic proceedings, it treats response variables as well as explanatory variables as random variables making no difference between input and output variables. Using a graphical representation Bayesian networks encode the dependency relations between the variables in a directed acyclic graph: variables are represented as nodes and (in-)dependencies between variables as (missing) edges between the nodes. The joint distribution of all variables can thus be described by decomposing it, according to the depicted independences, into a product of local conditional probability distributions, which are defined by the parameters of the Bayesian network. In the framework of this thesis the Bayesian network approach is applied to different natural hazard domains (i.e. seismic hazard, flood damage and landslide assessments). Learning the network structure and parameters from data, Bayesian networks reveal relevant dependency relations between the included variables and help to gain knowledge about the underlying processes. The problem of Bayesian network learning is cast in a Bayesian framework, considering the network structure and parameters as random variables itself and searching for the most likely combination of both, which corresponds to the maximum a posteriori (MAP score) of their joint distribution given the observed data. Although well studied in theory the learning of Bayesian networks based on real-world data is usually not straight forward and requires an adoption of existing algorithms. Typically arising problems are the handling of continuous variables, incomplete observations and the interaction of both. Working with continuous distributions requires assumptions about the allowed families of distributions. To "let the data speak" and avoid wrong assumptions, continuous variables are instead discretized here, thus allowing for a completely data-driven and distribution-free learning. An extension of the MAP score, considering the discretization as random variable as well, is developed for an automatic multivariate discretization, that takes interactions between the variables into account. The discretization process is nested into the network learning and requires several iterations. Having to face incomplete observations on top, this may pose a computational burden. Iterative proceedings for missing value estimation become quickly infeasible. A more efficient albeit approximate method is used instead, estimating the missing values based only on the observations of variables directly interacting with the missing variable. Moreover natural hazard assessments often have a primary interest in a certain target variable. The discretization learned for this variable does not always have the required resolution for a good prediction performance. Finer resolutions for (conditional) continuous distributions are achieved with continuous approximations subsequent to the Bayesian network learning, using kernel density estimations or mixtures of truncated exponential functions. All our proceedings are completely data-driven. We thus avoid assumptions that require expert knowledge and instead provide domain independent solutions, that are applicable not only in other natural hazard assessments, but in a variety of domains struggling with uncertainties.}, language = {en} } @phdthesis{Mabrok2013, author = {Mabrok, Hoda Hussein Bakr}, title = {Protective role of lignan-converting bacteria on chemically-induced breast cancer in gnotobiotic rats}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64933}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Enterolignans (enterodiol and enterolactone) exhibit structural similarity to estradiol and have therefore been hypothesized to modulate hormone related cancers such as breast cancer. The bioactivation of the plant lignan secoisolariciresinol diglucoside (SDG) requires the transformation by intestinal bacteria including the deglycosylation of SDG to secoisolariciresinol (SECO) followed by demethylation and dehydroxylation of SECO to enterodiol (ED). Finally, ED is dehydrogenated to enterolactone (EL). It is unclear whether the bacterial activation of SDG to ED and EL is crucial for the cancer preventing effects of dietary lignans. The possible protective effect of bacterial lignan transformation on a 7,12 dimethylbenz(a)anthracene (DMBA)-induced breast cancer in gnotobiotic rats was investigated. Germ-free rats were associated with a defined lignan-converting consortium (Clostridium saccharogumia, Blautia producta, Eggerthella lenta, and Lactonifactor longoviformis). The rats colonized with lignan-converting bacteria consortium (LCC) were fed a lignan-rich flaxseed diet and breast cancer was chemical induced. Identically treated germ-free rats served as control. All bacteria of the consortium successfully colonized the intestine of the LCC rats. The plant lignan SDG was converted into the enterolignans ED and EL in the LCC rats but not in the germ-free rats. This transformation did not influence cancer incidence but significantly decreased tumor numbers per tumor-bearing rat, and tumor size. Cell proliferation was significantly inhibited and apoptosis was significantly induced in LCC rats. No differences between LCC and control rats were observed in the expression of the genes encoding the estrogen receptors (ERα and ERβ) and G-coupled protein receptor 30 (GPR30). Similar findings were observed for both insulin-like growth factor 1 (IGF-1) and epidermal growth factor receptor (EGFR) genes involved in tumor growth. Proteome analysis revealed that 24 proteins were differentially expressed in tumor tissue from LCC and germ-free. RanBP-type and C3HC4-type zinc finger-containing protein 1 (RBCK1) and poly(rC)-binding protein 1 (PBCP1) were down-regulated by 3.2- and 2.0-fold, respectively. These proteins are associated with cell proliferation. The activity of selected enzymes involved in the degradation of oxidants in plasma and liver was significantly increased in the LCC rats. However, plasma and liver concentrations of reduced glutathione (non-enzymatic antioxidant) and malondialdehyde (oxidative stress marker) did not differ between the groups. In conclusion, the bacterial conversion of plant lignan to enterolignans beneficially influences their anti-cancer effect. However, the mechanisms involved in these effects remain elusive.}, language = {en} } @phdthesis{Nass2013, author = {Naß, Andrea}, title = {Konzeption und Implementierung eines GIS-basierten Kartierungssystems f{\"u}r die geowissenschaftliche Planetenforschung}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-65298}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Die Kartierung planetarer K{\"o}rper stellt ein wesentliches Mittel der raumfahrtgest{\"u}tzten Exploration der Himmelsk{\"o}rper dar. Aktuell kommen zur Erstellung der planetaren Karten Geo-Informationssysteme (GIS) zum Einsatz. Ziel dieser Arbeit ist es, eine GIS-orientierte Prozesskette (Planetary Mapping System (PMS)) zu konzipieren, mit dem Schwerpunkt geologische und geomorphologische Karten planetarer Oberfl{\"a}chen einheitlich durchf{\"u}hren zu k{\"o}nnen und nachhaltig zug{\"a}nglich zu machen.}, language = {de} } @phdthesis{Buller2013, author = {Buller, Jens}, title = {Entwicklung neuer stimuli-sensitiver Hydrogelfilme als Plattform f{\"u}r die Biosensorik}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-66261}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Diese Arbeit befasst sich mit der Synthese und der Charakterisierung von thermoresponsiven Polymeren und ihrer Immobilisierung auf festen Oberfl{\"a}chen als nanoskalige d{\"u}nne Schichten. Dabei wurden thermoresponsive Polymere vom Typ der unteren kritischen Entmischungstemperatur (engl.: lower critical solution temperature, LCST) verwendet. Sie sind bei niedrigeren Temperaturen im L{\"o}sungsmittel gut und nach Erw{\"a}rmen oberhalb einer bestimmten kritischen Temperatur nicht mehr l{\"o}slich; d. h. sie weisen bei einer bestimmten Temperatur einen Phasen{\"u}bergang auf. Als Basismaterial wurden verschiedene thermoresponsive und biokompatible Polymere basierend auf Diethylenglykolmethylethermethacrylat (MEO2MA) und Oligo(ethylenglykol)methylethermethacrylat (OEGMA475, Mn = 475 g/ mol) {\"u}ber frei radikalische Copolymerisation synthetisiert. Der thermoresponsive Phasen{\"u}bergang der Copolymere wurde in w{\"a}ssriger L{\"o}sung und in gequollenen vernetzten d{\"u}nnen Schichten beobachtet. Außerdem wurde untersucht, inwiefern eine selektive Proteinbindung an geeignete funktionalisierte Copolymere die Phasen{\"u}bergangstemperatur beeinflusst. Die thermoresponsiven Copolymere wurden {\"u}ber photovernetzbare Gruppen auf festen Oberfl{\"a}chen immobilisiert. Die n{\"o}tigen lichtempfindlichen Vernetzereinheiten wurden mittels des polymerisierbaren Benzophenonderivates 2 (4 Benzoylphenoxy)ethylmethacrylat (BPEM) in das Copolymer integriert. D{\"u}nne Filme der Copolymere mit ca. 100 nm Schichtdicke wurden {\"u}ber Rotationsbeschichtung auf Siliziumwafer aufgeschleudert und anschließend durch Bestrahlung mit UV Licht vernetzt und auf der Oberfl{\"a}che immobilisiert. Die Filme sind stabiler je gr{\"o}ßer der Vernetzeranteil und je gr{\"o}ßer die Molmasse der Copolymere ist. Bei einem Waschprozess nach der Vernetzung wird beispielsweise aus einem Film mit moderater Molmasse und geringem Vernetzeranteil mehr unvernetztes Copolymer ausgewaschen als bei einem h{\"o}hermolekularen Copolymer mit hohem Vernetzeranteil. Die Quellbarkeit der Polymerschichten wurde mit Ellipsometrie untersucht. Sie ist gr{\"o}ßer je geringer der Vernetzeranteil in den Copolymeren ist. Schichten aus thermoresponsiven OEG Copolymeren zeigen einen Volumenphasen{\"u}bergang vom Typ der LCST. Der thermoresponsive Kollaps der Schichten ist komplett reversibel, die Kollapstemperatur kann {\"u}ber die Zusammensetzung der Copolymere eingestellt werden. F{\"u}r einen Vergleich dieser Eigenschaften mit dem gut charakterisierten und derzeit wohl am h{\"a}ufigsten untersuchten thermoresponsiven Polymer Poly(N-isopropylacrylamid) (PNIPAM) wurden zus{\"a}tzlich photovernetzte Schichten aus PNIPAM hergestellt und ebenfalls ellipsometrisch vermessen. Im Vergleich zu PNIPAM verl{\"a}uft der Phasen{\"u}bergang der Schichten aus den Copolymeren mit Oligo(ethylenglykol)-seitenketten (OEG Copolymere) {\"u}ber einen gr{\"o}ßeren Temperaturbereich. Mit Licht einer Wellenl{\"a}nge > 300 nm wurden die photosensitiven Benzophenongruppen selektiv angeregt. Bei der Verwendung kleinerer Wellenl{\"a}ngen vernetzten die Copolymerschichten auch ohne die Anwesenheit der lichtempfindlichen Benzophenongruppen. Dieser Effekt ließ sich zur kontrollierten Immobilisierung und Vernetzung der OEG Copolymere einsetzen. Als weitere Methode zur Immobilisierung der Copolymere wurde die Anbindung {\"u}ber Amidbindungen untersucht. Dazu wurden OEG Copolymere mit dem carboxylgruppenhaltigen 2 Succinyloxyethylmethacrylat (MES) auf mit 3 Aminopropyldimethylethoxysilan (APDMSi) silanisierte Siliziumwafer rotationsbeschichtet, und mit dem oligomeren α, ω Diamin Jeffamin® ED 900 vernetzt. Die Vernetzungsreaktion erfolgte ohne weitere Zus{\"a}tze durch Erhitzen der Proben. Die Hydrogelschichten waren anschließend stabil und zeigten neben thermoresponsivem auch pH responsives Verhalten. Um zu untersuchen, ob die Phasen{\"u}bergangstemperatur durch eine Proteinbindung beeinflusst werden kann, wurde ein polymerisierbares Biotinderivat 2 Biotinyl-aminoethylmethacrylat (BAEMA) in das thermoresponsive Copolymer eingebaut. Der Einfluss des biotinbindenen Proteins Avidin auf das thermoresponsive Verhalten des Copolymers in L{\"o}sung wurde untersucht. Die spezifische Bindung von Avidin an das biotinylierte Copolymer verschob die {\"U}bergangstemperatur deutlich zu h{\"o}heren Temperaturen. Kontrollversuche zeigten, dass dieses Verhalten auf eine selektive Proteinbindung zur{\"u}ckzuf{\"u}hren ist. Thermoresponsive OEG Copolymere mit photovernetzbaren Gruppen aus BPEM und Biotingruppen aus BAEMA wurden {\"u}ber Rotationsbeschichtung auf Gold- und auf Siliziumoberfl{\"a}chen aufgetragen und durch UV Strahlung vernetzt. Die spezifische Bindung von Avidin an die Copolymerschicht wurde mit Oberfl{\"a}chenplasmonenresonanz und Ellipsometrie untersucht. Die Bindungskapazit{\"a}t der Schichten war umso gr{\"o}ßer, je kleiner der Vernetzeranteil, d. h. je gr{\"o}ßer die Maschenweite des Netzwerkes war. Die Quellbarkeit der Schichten wurde durch die Avidinbindung erh{\"o}ht. Bei hochgequollenen Systemen verursachte eine Mehrfachbindung des tetravalenten Avidins allerdings eine zus{\"a}tzliche Quervernetzung des Polymernetzwerkes. Dieser Effekt wirkt der erh{\"o}hten Quellbarkeit durch die Avidinbindung entgegen und l{\"a}sst die Polymernetzwerke schrumpfen.}, language = {de} } @phdthesis{Lange2013, author = {Lange, Dustin}, title = {Effective and efficient similarity search in databases}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-65712}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Given a large set of records in a database and a query record, similarity search aims to find all records sufficiently similar to the query record. To solve this problem, two main aspects need to be considered: First, to perform effective search, the set of relevant records is defined using a similarity measure. Second, an efficient access method is to be found that performs only few database accesses and comparisons using the similarity measure. This thesis solves both aspects with an emphasis on the latter. In the first part of this thesis, a frequency-aware similarity measure is introduced. Compared record pairs are partitioned according to frequencies of attribute values. For each partition, a different similarity measure is created: machine learning techniques combine a set of base similarity measures into an overall similarity measure. After that, a similarity index for string attributes is proposed, the State Set Index (SSI), which is based on a trie (prefix tree) that is interpreted as a nondeterministic finite automaton. For processing range queries, the notion of query plans is introduced in this thesis to describe which similarity indexes to access and which thresholds to apply. The query result should be as complete as possible under some cost threshold. Two query planning variants are introduced: (1) Static planning selects a plan at compile time that is used for all queries. (2) Query-specific planning selects a different plan for each query. For answering top-k queries, the Bulk Sorted Access Algorithm (BSA) is introduced, which retrieves large chunks of records from the similarity indexes using fixed thresholds, and which focuses its efforts on records that are ranked high in more than one attribute and thus promising candidates. The described components form a complete similarity search system. Based on prototypical implementations, this thesis shows comparative evaluation results for all proposed approaches on different real-world data sets, one of which is a large person data set from a German credit rating agency.}, language = {en} } @phdthesis{Kyprianidis2013, author = {Kyprianidis, Jan Eric}, title = {Structure adaptive stylization of images and video}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64104}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {In the early days of computer graphics, research was mainly driven by the goal to create realistic synthetic imagery. By contrast, non-photorealistic computer graphics, established as its own branch of computer graphics in the early 1990s, is mainly motivated by concepts and principles found in traditional art forms, such as painting, illustration, and graphic design, and it investigates concepts and techniques that abstract from reality using expressive, stylized, or illustrative rendering techniques. This thesis focuses on the artistic stylization of two-dimensional content and presents several novel automatic techniques for the creation of simplified stylistic illustrations from color images, video, and 3D renderings. Primary innovation of these novel techniques is that they utilize the smooth structure tensor as a simple and efficient way to obtain information about the local structure of an image. More specifically, this thesis contributes to knowledge in this field in the following ways. First, a comprehensive review of the structure tensor is provided. In particular, different methods for integrating the minor eigenvector field of the smoothed structure tensor are developed, and the superiority of the smoothed structure tensor over the popular edge tangent flow is demonstrated. Second, separable implementations of the popular bilateral and difference of Gaussians filters that adapt to the local structure are presented. These filters avoid artifacts while being computationally highly efficient. Taken together, both provide an effective way to create a cartoon-style effect. Third, a generalization of the Kuwahara filter is presented that avoids artifacts by adapting the shape, scale, and orientation of the filter to the local structure. This causes directional image features to be better preserved and emphasized, resulting in overall sharper edges and a more feature-abiding painterly effect. In addition to the single-scale variant, a multi-scale variant is presented, which is capable of performing a highly aggressive abstraction. Fourth, a technique that builds upon the idea of combining flow-guided smoothing with shock filtering is presented, allowing for an aggressive exaggeration and an emphasis of directional image features. All presented techniques are suitable for temporally coherent per-frame filtering of video or dynamic 3D renderings, without requiring expensive extra processing, such as optical flow. Moreover, they can be efficiently implemented to process content in real-time on a GPU.}, language = {en} } @phdthesis{Yang2013, author = {Yang, Haojin}, title = {Automatic video indexing and retrieval using video ocr technology}, address = {Potsdam}, pages = {182 S.}, year = {2013}, language = {en} } @phdthesis{Trapp2013, author = {Trapp, Matthias}, title = {Interactive rendering techniques for focus+context visualization of 3D geovirtual environments}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-66824}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {This thesis introduces a collection of new real-time rendering techniques and applications for focus+context visualization of interactive 3D geovirtual environments such as virtual 3D city and landscape models. These environments are generally characterized by a large number of objects and are of high complexity with respect to geometry and textures. For these reasons, their interactive 3D rendering represents a major challenge. Their 3D depiction implies a number of weaknesses such as occlusions, cluttered image contents, and partial screen-space usage. To overcome these limitations and, thus, to facilitate the effective communication of geo-information, principles of focus+context visualization can be used for the design of real-time 3D rendering techniques for 3D geovirtual environments (see Figure). In general, detailed views of a 3D geovirtual environment are combined seamlessly with abstracted views of the context within a single image. To perform the real-time image synthesis required for interactive visualization, dedicated parallel processors (GPUs) for rasterization of computer graphics primitives are used. For this purpose, the design and implementation of appropriate data structures and rendering pipelines are necessary. The contribution of this work comprises the following five real-time rendering methods: • The rendering technique for 3D generalization lenses enables the combination of different 3D city geometries (e.g., generalized versions of a 3D city model) in a single image in real time. The method is based on a generalized and fragment-precise clipping approach, which uses a compressible, raster-based data structure. It enables the combination of detailed views in the focus area with the representation of abstracted variants in the context area. • The rendering technique for the interactive visualization of dynamic raster data in 3D geovirtual environments facilitates the rendering of 2D surface lenses. It enables a flexible combination of different raster layers (e.g., aerial images or videos) using projective texturing for decoupling image and geometry data. Thus, various overlapping and nested 2D surface lenses of different contents can be visualized interactively. • The interactive rendering technique for image-based deformation of 3D geovirtual environments enables the real-time image synthesis of non-planar projections, such as cylindrical and spherical projections, as well as multi-focal 3D fisheye-lenses and the combination of planar and non-planar projections. • The rendering technique for view-dependent multi-perspective views of 3D geovirtual environments, based on the application of global deformations to the 3D scene geometry, can be used for synthesizing interactive panorama maps to combine detailed views close to the camera (focus) with abstract views in the background (context). This approach reduces occlusions, increases the usage the available screen space, and reduces the overload of image contents. • The object-based and image-based rendering techniques for highlighting objects and focus areas inside and outside the view frustum facilitate preattentive perception. The concepts and implementations of interactive image synthesis for focus+context visualization and their selected applications enable a more effective communication of spatial information, and provide building blocks for design and development of new applications and systems in the field of 3D geovirtual environments.}, language = {en} } @phdthesis{Plume2013, author = {Plume, Anna-Marleen}, title = {Die Dominanz traditioneller Familienarrangements : eine Analyse des geschlechtsspezifischen Arbeitsangebotsverhaltens in Deutschland}, series = {Vollkswirtschaftliche Forschungsergebnisse}, volume = {186}, journal = {Vollkswirtschaftliche Forschungsergebnisse}, publisher = {Kova?}, address = {Hamburg}, isbn = {978-3-8300-6879-2}, issn = {1435-6872}, pages = {270 S.}, year = {2013}, language = {de} } @phdthesis{Reichelt2013, author = {Reichelt, Jonas}, title = {Informationssuche und Online Word-of-Mouth : eine empirische Analyse anhand von Diskussionsforen}, publisher = {Springer Fachmedien Wiesbaden}, address = {Wiesbaden}, isbn = {978-3-658-01372-1}, pages = {330 S.}, year = {2013}, language = {de} } @phdthesis{Form2013, author = {Form, Laurens}, title = {Im Blick des Zweiten : die DDR-Sportberichterstattung im ZDF ; eine quantitative und qualitative Analyse anhand ausgew{\"a}hlter Beispiel aus dem Programm des Zweiten Deutschen Fernsehens (ZDF)}, volume = {87}, publisher = {Kova?}, address = {Hamburg}, isbn = {978-3-8300-6973-7}, pages = {470 S.}, year = {2013}, language = {de} } @phdthesis{Rakow2013, author = {Rakow, Bastian}, title = {{\"O}kologische Industriepolitik in Deutschland und Europa : eine volkswirtschaftliche Analyse des Konzeptes}, series = {Europ{\"a}ische Hochschulschriften Reihe 5 Volks- und Betriebswirtschaft}, volume = {3424}, journal = {Europ{\"a}ische Hochschulschriften Reihe 5 Volks- und Betriebswirtschaft}, publisher = {Peter Lang GmbH Internationaler Verlag der Wissenschaften}, address = {Frankfurt}, isbn = {978-3-631-64032-6}, issn = {0531-7339}, pages = {268 S.}, year = {2013}, language = {de} } @phdthesis{Kraus2013, author = {Kraus, Sissy Manuela}, title = {Menschenrechtliche Aspekte der Staatenlosigkeit}, publisher = {BWV Berliner Wissenschafts-Verlag}, address = {Berlin}, isbn = {978-3-8305-3157-9}, pages = {317 S.}, year = {2013}, language = {de} } @phdthesis{Otto2013, author = {Otto, Sebastian}, title = {Zulassungskonforme und schnelle massenspektronomische Analytik und pr{\"a}klinische Pharmakokinetik neuer Wirkstoffkandidaten}, address = {Potsdam}, pages = {143 S.}, year = {2013}, language = {de} } @phdthesis{Wiemann2013, author = {Wiemann, Rebekka}, title = {Sexuelle Orientierung im V{\"o}lker- und Europarecht : zwischen kulturellem Relativismus und Universalismus}, series = {Menschenrechtszentrum der Universit{\"a}t Potsdam}, volume = {36}, journal = {Menschenrechtszentrum der Universit{\"a}t Potsdam}, publisher = {BWV Berliner Wiss.-Verl.}, address = {Berlin}, isbn = {978-3-8305-3121-0}, pages = {341 S.}, year = {2013}, language = {de} } @phdthesis{Casertano2013, author = {Casertano, Stefano}, title = {Our Land, our oil! : natural resources, local nationalism, and violent secession}, publisher = {Springer}, address = {Wiesbaden}, isbn = {978-3-531-19442-4}, doi = {10.1007/978-3-531-19443-1}, pages = {311 S.}, year = {2013}, language = {en} } @phdthesis{Mende2013, author = {Mende, Jan}, title = {Die Tonwarenfabrik : Tobias Chr. Feilner in Berlin ; Kunst und Industrie im Zeitalter Schinkels}, series = {Kunstwissenschaftliche Studien}, volume = {178}, journal = {Kunstwissenschaftliche Studien}, publisher = {Dt. Kunstverl.}, address = {Berlin}, isbn = {978-3-422-07207-7}, pages = {511 S.}, year = {2013}, language = {de} } @phdthesis{Dechtrirat2013, author = {Dechtrirat, Decha}, title = {Combination of self-assembled monolayers (SAMs) and molecularly imprinted polymers (MIPs) in biomimetic sensors}, address = {Potsdam}, pages = {107 S.}, year = {2013}, language = {en} } @phdthesis{Buhl2013, author = {Buhl, Elmar}, title = {Brittle deformation of porous sandstone in hypervelocity impact experiments}, address = {Potsdam}, pages = {124 S.}, year = {2013}, language = {en} } @phdthesis{Reschke2013, author = {Reschke, Stefan}, title = {Untersuchungen zur Bildung und Modifizierung des Molybd{\"a}ncofaktors und dessen Einbau in Molybdoenzyme}, address = {Potsdam}, pages = {133 S.}, year = {2013}, language = {de} } @phdthesis{Menon2013, author = {Menon, Arathy}, title = {Indian summer monsoon : future variability, extreme events and effects of lagged adaptation}, address = {Potsdam}, pages = {80 S.}, year = {2013}, language = {en} } @phdthesis{Zulawski2013, author = {Zulawski, Monika Anna}, title = {Die Rolle der Phosphorylierung in der Regulation pflanzlicher Proteine}, address = {Potsdam}, pages = {160 S.}, year = {2013}, language = {de} } @phdthesis{Garapati2013, author = {Garapati, Prashanth}, title = {Functional characterization of H2=2-responsive NAC transcription factors ATAF1 and JUB1 in Arabidopsis thaliana}, address = {Potsdam}, pages = {177, V S.}, year = {2013}, language = {en} } @phdthesis{Gros2013, author = {Gros, Oliver}, title = {Computergest{\"u}tzte Wissensextraktion aus befundtexten der Pathologie}, address = {Potsdam}, pages = {170 S.}, year = {2013}, language = {de} } @phdthesis{Attermeyer2013, author = {Attermeyer, Katrin}, title = {Effects of allochthonous organic carbon on bacterial metabolism and community structure, and consequences for carbon cycling in smal, shallow lakes}, address = {Potsdam}, pages = {182 S.}, year = {2013}, language = {en} } @phdthesis{Yu2013, author = {Yu, Linghui}, title = {Hydrothermal synthesis of carbon and carbon nanocomposite materials for environmental and energy applications}, address = {Potsdam}, pages = {103 S.}, year = {2013}, language = {en} } @phdthesis{Haberlandt2013, author = {Haberlandt, Niels}, title = {Rechtsextreme Strategien im Sport : der organisierte Sport im strategischen Konzept rechtsextremer Gruppen im Land Brandenburg}, series = {Region - Nation - Europa}, volume = {73 i.e. 72}, journal = {Region - Nation - Europa}, publisher = {LIT-Verl.}, address = {Berlin}, isbn = {978-3-643-11993-3}, pages = {228 S.}, year = {2013}, language = {de} } @phdthesis{Meyer2013, author = {Meyer, Lars}, title = {The working memory of argument - verb dependencies : spatiotemporal brain dynamics during sentence processing}, series = {MPI Series in human cognitive and brain sciences}, volume = {145}, journal = {MPI Series in human cognitive and brain sciences}, publisher = {Max Planck Inst. for Human Cognitive and Brain Sciences}, address = {Leipzig}, isbn = {978-3-941504-29-5}, pages = {193 S.}, year = {2013}, language = {en} } @phdthesis{Grabow2013, author = {Grabow, Stefan}, title = {Die Sicherungserpressung}, series = {Schriften zum Strafrecht}, volume = {240}, journal = {Schriften zum Strafrecht}, publisher = {Duncker \& Humblot}, address = {Berlin}, isbn = {978-3-428-14027-5}, doi = {10.3790/978-3-428-54027-3}, pages = {276 S.}, year = {2013}, language = {de} } @phdthesis{Serno2013, author = {Serno, Sascha}, title = {Marine productivity and eolian dust supply in the subarctic north pacific : proxy development and evaluation in marine sediments}, address = {Potsdam}, pages = {216 S.}, year = {2013}, language = {en} } @phdthesis{Grohme2013, author = {Grohme, Markus Alexander}, title = {Molecular adaptations to anhydrobiosis in the tardigrade Milnesium tardigradum}, address = {Potsdam}, year = {2013}, language = {en} } @phdthesis{Galeazzi2013, author = {Galeazzi, Filippo}, title = {Towards realistic modeling of relativistic stars}, address = {Potsdam}, pages = {195 S.}, year = {2013}, language = {en} } @phdthesis{Meyer2013, author = {Meyer, Elske}, title = {Vorstandsverg{\"u}tung : eine rechts{\"o}konomische Analyse zur Angemessenheit der Vorstandsverg{\"u}tung}, series = {Schriften zum Gesellschafts-, Bank- und Kapitalmarktrecht}, volume = {36}, journal = {Schriften zum Gesellschafts-, Bank- und Kapitalmarktrecht}, publisher = {Nomos}, address = {Baden-Baden}, isbn = {978-3-8329-7639-2}, pages = {354 S.}, year = {2013}, language = {de} } @phdthesis{Mueller2013, author = {M{\"u}ller, Frank J.}, title = {Integrative Grundschulen aus Sicht der Eltern - auf dem Weg zur Inklusion? : eine qualitative/quantitative Erhebung zur Elternzufriedenheit}, publisher = {Klinkhardt}, address = {Bad Heilbrunn}, isbn = {978-3-7815-1935-0}, pages = {469 S.}, year = {2013}, language = {de} } @phdthesis{Steiger2013, author = {Steiger, Dominik}, title = {Das v{\"o}lkerrechtliche Folterverbot und der Krieg gegen den Terror}, series = {Beitr{\"a}ge zum ausl{\"a}ndischen {\"o}ffentlichen Recht und V{\"o}lkerrecht}, volume = {241}, journal = {Beitr{\"a}ge zum ausl{\"a}ndischen {\"o}ffentlichen Recht und V{\"o}lkerrecht}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-642-37154-7}, doi = {10.1007/978-3-642-37155-4}, pages = {XXX, 821 S.}, year = {2013}, language = {de} } @phdthesis{Jourdan2013, author = {Jourdan, Cornelia}, title = {Ordnungswidrigkeiten in Press und Rundfunk in Zeiten der Konvergenz}, series = {Europ{\"a}ische Hochschulschriften : Reihe Rechtswissenschaften}, volume = {5423}, journal = {Europ{\"a}ische Hochschulschriften : Reihe Rechtswissenschaften}, publisher = {PL Academic Research}, address = {Frankfurt}, isbn = {978-3-631-63774-6}, pages = {241 S.}, year = {2013}, language = {de} } @phdthesis{Neumann2013, author = {Neumann, Stefan}, title = {Modular timing analysis of component-based real-time embedded systems}, address = {Potsdam}, pages = {218 S.}, year = {2013}, language = {en} } @phdthesis{Hoff2013, author = {Hoff, Holger}, title = {Teleconnections in the global water system, their impacts on local water resources, and opportunities for addressing them in IWRM}, address = {Potsdam}, pages = {142 S.}, year = {2013}, language = {en} } @phdthesis{Schaefrich2013, author = {Sch{\"a}frich, Daniela}, title = {Die Verfahrensbefugnisse und Klagerechte Dritter im Bereich des {\"o}ffentlich-rechtlichen Bodenschutzes am Beispiel des Umweltschadensgesetzes}, series = {Europ{\"a}ische Hochschulschriften : Rechtswissenschaften}, volume = {5558}, journal = {Europ{\"a}ische Hochschulschriften : Rechtswissenschaften}, publisher = {Peter Lang GmbH Internationaler Verlag der Wissenschaften}, address = {Frankfurt}, isbn = {978-3-631-64202-3}, pages = {240 S.}, year = {2013}, language = {de} } @phdthesis{Broedel2013, author = {Br{\"o}del, Andreas K.}, title = {Novel cell-free systems for increasing efficiency and versatility of protein synthesis}, address = {Potsdam}, pages = {137 S.}, year = {2013}, language = {en} } @phdthesis{Tartivel2013, author = {Tartivel, Lucile}, title = {Design of hydrogels with inverse shape-memory function for biomedical applications}, address = {Potsdam}, pages = {150 S.}, year = {2013}, language = {en} } @phdthesis{Fiedler2013, author = {Fiedler, Sebastian}, title = {Thermodynamic stability of the a-Helical membrane-interacting protein mistic in detergent micelles}, address = {Potsdam}, pages = {99 S.}, year = {2013}, language = {en} } @phdthesis{Arnold2013, author = {Arnold, Gabriele}, title = {Spektrale Fernerkundung der terristrischen Planetoberfl{\"a}chen von Merkur, Venus und Mars vom visuellen bis in den infraroten Wellenl{\"a}ngenbereich}, address = {Potsdam}, pages = {573 S.}, year = {2013}, language = {de} } @phdthesis{Barknowitz2013, author = {Barknowitz, Gitte}, title = {Serumalbumin- und H{\"a}moglobin-Addukte als Biomarker der Exposition gegen{\"u}ber Mutagenen Metaboliten von 1-Methoxy-Indolylmethyl-Glucosinolat-Untersuchungen in Maus und Menschen}, address = {Potsdam}, pages = {118 S.}, year = {2013}, language = {de} } @phdthesis{Dominguez2013, author = {Dom{\´i}nguez, Pablo Haro}, title = {Nanostructured poly(benzimidazole)s by chemical modification}, address = {Potsdam}, pages = {95, XXVIII S.}, year = {2013}, language = {en} } @phdthesis{Kallweit2013, author = {Kallweit, Nils-Christian}, title = {Drittschutz aus dem Denkmalschutz}, series = {Schriften zum {\"O}ffentlich Recht}, volume = {1256}, journal = {Schriften zum {\"O}ffentlich Recht}, publisher = {Duncker \& Humblot}, address = {Berlin}, isbn = {978-3-428-14198-2}, issn = {0582-0200}, doi = {10.3790/978-3-428-54198-0}, pages = {276 S.}, year = {2013}, language = {de} } @phdthesis{Sydow2013, author = {Sydow, Bj{\"o}rn}, title = {Philosophische Anthropologie der Leidenschaften : {\"u}ber den Menschen als k{\"o}rperliches Wesen}, publisher = {Akademie-Verl.}, address = {Berlin}, isbn = {978-3-05-006256-3}, doi = {10.1524/9783050063386}, pages = {195 S.}, year = {2013}, language = {de} } @phdthesis{Wawrzinek2013, author = {Wawrzinek, Robert C. W.}, title = {Fluoreszenzfarbstoffe mit Dioxolobenzodioxol-Grundger{\"u}st: Synthese, Untersuchungen und Anwendungen}, address = {Potsdam}, pages = {214 S.}, year = {2013}, language = {de} } @phdthesis{Dahl2013, author = {Dahl, Jan-Ulrik}, title = {Characterization of the role of the sulfur carrier protein TusA for molybdenum cofactor biosynthesis in Escherichia coli}, address = {Potsdam}, year = {2013}, language = {en} } @phdthesis{Wiegelmann2013, author = {Wiegelmann, Alexander Martin}, title = {Risikotransfers in den Schattenfinanzsektor : Regulatorische und geldpolitische Reaktionen auf die Finanzkrise 2007/08}, address = {Potsdam}, pages = {324 S.}, year = {2013}, language = {de} } @phdthesis{Hintze2013, author = {Hintze, Ksenia}, title = {Entwicklung und Ausbildung des Gesundheitsbegriffs im Grundschulalter : Gesundheitsbildung nach der Lehr- und Lernstrategie des Aufsteigens vom Abstrakten zum Kronkreten}, series = {International Cultural-historical Human Sciences}, volume = {46}, journal = {International Cultural-historical Human Sciences}, publisher = {Lehmanns Media}, address = {Berlin}, isbn = {978-3-86541-567-7}, pages = {288 S.}, year = {2013}, language = {de} } @phdthesis{Lehmann2013, author = {Lehmann, Carsten}, title = {Glucosinolate in der entz{\"u}ndungsgetriebenen Kolonkanzerogenese - Induktion von Phase I und Phase II Enzymen sowie der Einfluss der intestinalen Mikrobiota}, address = {Potsdam}, pages = {117 S.}, year = {2013}, language = {de} } @phdthesis{Schleussner2013, author = {Schleussner, Carl-Friedrich}, title = {Variability and trend of the North Atlantic ocean circulation in past and future climate}, address = {Potsdam}, pages = {127 S.}, year = {2013}, language = {en} } @phdthesis{Picchi2013, author = {Picchi, Douglas Gatte}, title = {On the characterisation of biosynthetic pathways and functional metagenomic approaches of cyanobacterial peptides}, address = {Potsdam}, pages = {146 S}, year = {2013}, language = {en} } @phdthesis{Greco2013, author = {Greco, Tonino Lucio}, title = {Synthese von Halbleiter-Nanopartikeln zur Anwendung in Licht-ermittierenden Dioden}, address = {Potsdam}, pages = {158 S.}, year = {2013}, language = {de} }