@phdthesis{Carstensen2018,
  author    = {Carstensen, Janet},
  title     = {Modellentwicklung f{\"u}r eine wirtschaftsorientierte Ausbildung vor dem Hintergrund des Generationenwandels am Beispiel Potsdam},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417542},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XII, 217, L},
  year      = {2018},
  abstract  = {Die deutsche Berufsausbildung hat in den vergangenen Jahren stark an Zuspruch verloren. Dies trifft insbesondere auch auf die duale kaufm{\"a}nnische Berufsausbildung zu. Galt sie vor einigen Jahren noch als ein m{\"o}glicher Ausbildungsweg f{\"u}r leistungsstarke Sch{\"u}ler/-innen, pr{\"a}ferieren diese heute zum großen Teil das Studium. Die wachsende Anzahl an Studienabbrechern belegt jedoch, dass dadurch auch Potenzial verloren geht, weil sich Jugendliche mit dem Studium f{\"u}r einen Ausbildungsweg entscheiden, der f{\"u}r sie nicht geeignet ist. Bisherige Bem{\"u}hungen zur Etablierung alternativer Bildungswege wie zum Beispiel Berufsakademien weisen zwar Erfolge auf, basieren jedoch auf einem Konzept, das sich ausschließlich am Bedarf der Wirtschaft orientiert. Es ist jedoch die {\"U}berzeugung der Autorin, dass neue innovative Bildungswege auch die Bed{\"u}rfnisse und Vorstellungen derjenigen ber{\"u}cksichtigen m{\"u}ssen, f{\"u}r die sie entworfen werden. Denn die Generation der heutigen Jugendlichen zeichnet sich dadurch aus, dass sie ein anderes Wertekonzept als ihre Vorg{\"a}ngergenerationen aufweist. Die Dissertation entwickelt daher ein Modell einer wirtschaftsorientierten Ausbildung, welches sich aus unterschiedlichen motivationstheoretischen Elementen ableitet und zugleich die Werte der Generation der heutigen Jugend-lichen ber{\"u}cksichtigt. Es umfasst sowohl die Anreiz-Beitrags-Theorie nach Barnard als auch die Inhalts-Erwartungstheorie nach Vroom. Zudem liegt ein Hauptaugenmerk dieser Arbeit auf der Anpassung der Zwei-Faktoren-Theorie nach Herzberg auf die heutige Zeit. Empirisch basiert die Dissertation auf einem dreistufigen Untersuchungsdesign. Die erste Stufe umfasst eine quantitative Befragung von insgesamt 459 Abiturienten/-innen und 100 Studierenden. In der zweiten Stufe wurden 10 Studieren-de und 12 Abiturienten/-innen qualitativ befragt. Eine Validierung der Ergebnis-se erfolgte in der dritten Stufe mittels Experteninterviews. Das Ziel der empirischen Untersuchung bestand in der {\"U}berpr{\"u}fung von vier Hypothesen als Basis zur Modellableitung: Hypothese H1 - Flexibilit{\"a}t erh{\"o}ht die Attraktivit{\"a}t einer wirtschaftsorientierten Ausbildung: Der Faktor Flexibilit{\"a}t wurde als ein relevanter Motivator f{\"u}r die Wahl eines Ausbildungsweges identifiziert. Jugendliche wollen sich heutzutage nicht sofort bzw. nicht zu fr{\"u}h festlegen m{\"u}ssen. Hypothese H2 - Auslandsaufenthalte erh{\"o}hen die Attraktivit{\"a}t einer wirtschaftsorientierten Ausbildung: Es wurde best{\"a}tigt, dass Auslandsaufenthalte die Attraktivit{\"a}t einer wirtschaftsorientierten Ausbildung steigert, es besteht jedoch eine Reihe von Barrieren, die Jugendliche (obwohl sie den grunds{\"a}tzlichen Vor-teil sehen) davon abhalten, einen Auslandsaufenthalt f{\"u}r sich selbst in Betracht zu ziehen. Hypothese H3 - Das Aufzeigen einer Karriereperspektive erh{\"o}ht die Attraktivit{\"a}t einer wirtschaftsorientierten Ausbildung: F{\"u}r die Generation der heutigen Jugendlichen steht bez{\"u}glich der Wahl ihres Ausbildungsweges die Aussicht auf eine T{\"a}tigkeit im Vordergrund, die ein gesichertes Einkommen und somit ein gutes Leben erm{\"o}glicht und zudem aus ihrer Sicht eine gewisse Sinnhaftigkeit hat. F{\"u}hrungspositionen, in denen auch h{\"o}here Verantwortung {\"u}bernommen wird, strebt nur eine Minderheit an. Hypothese H4 - Zus{\"a}tzliche monet{\"a}re Anreize erh{\"o}hen die Attraktivit{\"a}t einer wirtschaftsorientierten Ausbildung: Verg{\"u}tungsbestandteile werden grunds{\"a}tzlich nicht abgelehnt (das w{\"a}re auch irrational), haben jedoch auch nicht die Anreizfunktion, die ihr auf Basis der Voruntersuchung im Rahmen dieser Arbeit h{\"a}tte unterstellt werden k{\"o}nnen. F{\"u}r die Entscheidungsfindung bez{\"u}glich eines Ausbildungsweges spielen sie nur eine untergeordnete Rolle. Dennoch tr{\"a}gt die Verg{\"u}tung zur Attraktivit{\"a}t eines Ausbildungsweges bei. Basierend auf den zuvor genannten Ergebnissen wurde das Modell einer wirtschaftsorientieren Ausbildung abgeleitet, das sowohl horizontal als auch vertikal flexibel ist. Horizontale Flexibilit{\"a}t ist dadurch gegeben, dass innerhalb eines Ausbildungsjahres unterschiedliche Unternehmen und Branchen kennengelernt werden (Jahr 1 und Jahr 2). Eine Spezialisierung erfolgt erst in den sp{\"a}teren Ausbildungsjahren. Durch die M{\"o}glichkeit, nach jedem Ausbildungsjahr mit einem Abschluss ins Berufsleben zu wechseln und die Ausbildung gegebenenfalls zu einem sp{\"a}teren Zeitpunkt fortzusetzen, ist auch eine vertikale Flexibilit{\"a}t gegeben. Zudem bietet das Modell Studienabbrechern/-innen die M{\"o}glichkeit, im Ausbildungsjahr 2 bzw. 3 in die Ausbildung einzusteigen. Im Jahr 2 und/oder Jahr 3 sind Auslandsaufenthalte integriert. Diese werden fakultativ an-geboten. Bereits ab dem Jahr 1 besteht die M{\"o}glichkeit, Vorbereitungskurse zu belegen. Der hohen Bedeutung der Karriereperspektive wird im abgeleiteten Modell auf mehreren Ebenen Rechnung getragen. So werden nach jedem Ausbildungsjahr anerkannte Abschl{\"u}sse erreicht. W{\"a}hrend diese in den Jahren 1 und 2 mit IHK-Abschl{\"u}ssen gleichzusetzen sind, beginnen ab Jahr 3 die akademischen Graduierungen (Jahr 3 Bachelor, Jahr 4 Master). Die Verg{\"u}tung wird Bestandteil einer wirtschaftsorientierten Ausbildung, wobei ihre H{\"o}he mit Dauer der Ausbildung zunimmt. Da mit der Einf{\"u}hrung des Modells einer wirtschaftsorientierten Ausbildung die {\"U}berwindung von institutionellen Paradigmen und Schranken verbunden sind, erfolgte im Rahmen des Ausblicks der Arbeit eine weitere Expertenbefragung bez{\"u}glich seiner Umsetzbarkeit. Es setzt eine Beweglichkeit von institutioneller Seite voraus (hierbei insbesondere auch von den Kammern), die von der Mehr-zahl der Experten derzeit skeptisch gesehen wird. Die konzeptionelle Ausgestaltung findet grunds{\"a}tzlichen Zuspruch, wobei in einigen Details, zum Beispiel in der Dauer der Ausbildung, noch Kl{\"a}rungsbedarf besteht. Grunds{\"a}tzlich schließen sich die Experten/-innen der Meinung der Autorin an, dass ein Sinneswandel in der deutschen Ausbildungslandschaft gew{\"u}nscht und gefordert wird. Dies betrifft insbesondere auch den kaufm{\"a}nnischen Bereich. Diese Arbeit liefert mit dem Modell der wirtschaftsorientierten Ausbildung einen wichtigen Beitrag zur Diskussion {\"u}ber neue Ausbildungswege.},
  language  = {de}
}
@phdthesis{Fer2018,
  author    = {Fer, Istem},
  title     = {Modeling past, present and future climate induced vegetation changes in East Africa},
  doi       = {10.25932/publishup-42777},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427777},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxii, 156},
  year      = {2018},
  abstract  = {Ostafrika ist ein nat{\"u}rliches Labor: Durch ein Studium seiner einzigartigen geologischen und biologischen Geschichte lassen sich unsere Theorien und Modelle {\"u}berpr{\"u}fen und verbessern. Ein Studium seiner Gegenwart und seiner Zukunft wiederum hilft uns dabei, die global bedeutende Artenvielfalt und die {\"o}kosystemaren Dienstleistungen Ostafrikas zu sch{\"u}tzen. Eine zentrale Rolle spielt dabei spielt die ostafrikanische Vegetation, deren Dynamiken in dieser Dissertation durch Computersimulationen quantifiziert werden sollen. {\"U}ber Computersimulationen lassen sich fr{\"u}here Rahmenbedingungen reproduzieren, Voraussagen treffen oder Simulationsexperimente durchf{\"u}hren, die durch Feldforschung nicht m{\"o}glich w{\"a}ren. Zuallererst muss jedoch ihre Leistungsf{\"a}higkeit {\"u}berpr{\"u}ft werden. Die von dem Modell anhand der heutigen Inputs gelieferten Ergebnisse stimmten weitgehend mit heutigen Beobachtungen ostafrikanischer Vegetation {\"u}berein. Als n{\"a}chstes wurde die fr{\"u}here Vegetation simuliert, f{\"u}r die fossile Pollen-Daten zum Abgleich vorliegen. {\"U}ber Computermodelle lassen sich Wissensl{\"u}cken zwischen Standorten {\"u}berbr{\"u}cken, bei denen wir {\"u}ber fossile Pollen-Daten verf{\"u}gen, sodass ein vollst{\"a}ndigeres Bild der Vergangenheit entsteht. Zus{\"a}tzlich validiert wurde die Leistungsf{\"a}higkeit des Modells durch die hohe {\"U}bereinstimmung zwischen Modell und Pollen-Daten, wo sie im Raum {\"u}berlappen. Nachdem das Modell getestet und f{\"u}r die Region validiert war, konnte eine der seit langem offenen Fragen {\"u}ber die ostafrikanische Vegetation angegangen werden, n{\"a}mlich wie Ostafrika seines Tropenwaldes verlustig gehen konnte. In den Tropen wird die heutige Vegetation weltweit haupts{\"a}chlich von W{\"a}ldern dominiert, mit Ausnahme der Tropengebiete Ostafrikas, wo W{\"a}lder nur noch stellenweise an der K{\"u}ste und im Hochland vorkommen. Durch eine Reihe von Simulationsexperimenten konnte aufgezeigt werden, unter welchen Bedingungen jene Waldgebiete fr{\"u}her zusammenhingen und schließlich fragmentiert wurden. Die Studie hat erwiesen, wie empfindlich die ostafrikanische Vegetation f{\"u}r die Klimaschwankungen ist, die durch den k{\"u}nftigen Klimawandel zu erwarten sind. Weitere Auswirkungen auf das ostafrikanische Klima ergeben sich aus dem El Ni{\~n}o/Southern Oscillation-Ph{\"a}nomen (ENSO), das aus Temperaturfluktuationen zwischen dem Ozean und der Atmosph{\"a}re herr{\"u}hrt und k{\"u}nftig an Intensit{\"a}t zunehmen d{\"u}rfte. Die derzeitigen Klimamodelle sind allerdings noch nicht gut genug beim Erfassen solcher Ereignismuster. In einer Studie wurde der Einfluss des ENSO-Ph{\"a}nomens auf die ostafrikanische Vegetation quantifiziert und dabei aufgezeigt, wie sehr sich die k{\"u}nftige Vegetation von den heute simulierten Ergebnissen unterscheiden k{\"o}nnte, bei denen der genaue ENSO-Beitrag nicht ber{\"u}cksichtigt werden kann. Bei der Berechnung der k{\"u}nftigen weltweiten CO2-Bilanz und den zu treffenden Entscheidungen stellt dies einen zus{\"a}tzlichen Unsicherheitsfaktor dar.},
  language  = {en}
}
@phdthesis{Pufahl2018,
  author    = {Pufahl, Luise},
  title     = {Modeling and executing batch activities in business processes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-408013},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xix, 163},
  year      = {2018},
  abstract  = {Business process automation improves organizations' efficiency to perform work. Therefore, a business process is first documented as a process model which then serves as blueprint for a number of process instances representing the execution of specific business cases. In existing business process management systems, process instances run independently from each other. However, in practice, instances are also collected in groups at certain process activities for a combined execution to improve the process performance. Currently, this so-called batch processing is executed manually or supported by external software. Only few research proposals exist to explicitly represent and execute batch processing needs in business process models. These works also lack a comprehensive understanding of requirements. This thesis addresses the described issues by providing a basic concept, called batch activity. It allows an explicit representation of batch processing configurations in process models and provides a corresponding execution semantics, thereby easing automation. The batch activity groups different process instances based on their data context and can synchronize their execution over one or as well multiple process activities. The concept is conceived based on a requirements analysis considering existing literature on batch processing from different domains and industry examples. Further, this thesis provides two extensions: First, a flexible batch configuration concept, based on event processing techniques, is introduced to allow run time adaptations of batch configurations. Second, a concept for collecting and batching activity instances of multiple different process models is given. Thereby, the batch configuration is centrally defined, independently of the process models, which is especially beneficial for organizations with large process model collections. This thesis provides a technical evaluation as well as a validation of the presented concepts. A prototypical implementation in an existing open-source BPMS shows that with a few extensions, batch processing is enabled. Further, it demonstrates that the consolidated view of several work items in one user form can improve work efficiency. The validation, in which the batch activity concept is applied to different use cases in a simulated environment, implies cost-savings for business processes when a suitable batch configuration is used. For the validation, an extensible business process simulator was developed. It enables process designers to study the influence of a batch activity in a process with regards to its performance.},
  language  = {en}
}
@phdthesis{Vogel2018,
  author    = {Vogel, Thomas},
  title     = {Model-driven engineering of self-adaptive software},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-409755},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvi, 357},
  year      = {2018},
  abstract  = {The development of self-adaptive software requires the engineering of an adaptation engine that controls the underlying adaptable software by a feedback loop. State-of-the-art approaches prescribe the feedback loop in terms of numbers, how the activities (e.g., monitor, analyze, plan, and execute (MAPE)) and the knowledge are structured to a feedback loop, and the type of knowledge. Moreover, the feedback loop is usually hidden in the implementation or framework and therefore not visible in the architectural design. Additionally, an adaptation engine often employs runtime models that either represent the adaptable software or capture strategic knowledge such as reconfiguration strategies. State-of-the-art approaches do not systematically address the interplay of such runtime models, which would otherwise allow developers to freely design the entire feedback loop. This thesis presents ExecUtable RuntimE MegAmodels (EUREMA), an integrated model-driven engineering (MDE) solution that rigorously uses models for engineering feedback loops. EUREMA provides a domain-specific modeling language to specify and an interpreter to execute feedback loops. The language allows developers to freely design a feedback loop concerning the activities and runtime models (knowledge) as well as the number of feedback loops. It further supports structuring the feedback loops in the adaptation engine that follows a layered architectural style. Thus, EUREMA makes the feedback loops explicit in the design and enables developers to reason about design decisions. To address the interplay of runtime models, we propose the concept of a runtime megamodel, which is a runtime model that contains other runtime models as well as activities (e.g., MAPE) working on the contained models. This concept is the underlying principle of EUREMA. The resulting EUREMA (mega)models are kept alive at runtime and they are directly executed by the EUREMA interpreter to run the feedback loops. Interpretation provides the flexibility to dynamically adapt a feedback loop. In this context, EUREMA supports engineering self-adaptive software in which feedback loops run independently or in a coordinated fashion within the same layer as well as on top of each other in different layers of the adaptation engine. Moreover, we consider preliminary means to evolve self-adaptive software by providing a maintenance interface to the adaptation engine. This thesis discusses in detail EUREMA by applying it to different scenarios such as single, multiple, and stacked feedback loops for self-repairing and self-optimizing the mRUBiS application. Moreover, it investigates the design and expressiveness of EUREMA, reports on experiments with a running system (mRUBiS) and with alternative solutions, and assesses EUREMA with respect to quality attributes such as performance and scalability. The conducted evaluation provides evidence that EUREMA as an integrated and open MDE approach for engineering self-adaptive software seamlessly integrates the development and runtime environments using the same formalism to specify and execute feedback loops, supports the dynamic adaptation of feedback loops in layered architectures, and achieves an efficient execution of feedback loops by leveraging incrementality.},
  language  = {en}
}
@phdthesis{SarnesNitu2018,
  author    = {Sarnes-Nitu, Juliane},
  title     = {Mit der Schuldenbremse zu nachhaltigen Staatsfinanzen?},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-413804},
  school      = {Universit{\"a}t Potsdam},
  pages     = {294},
  year      = {2018},
  abstract  = {The core question of this paper is: Does the debt brake secure fiscal sustainability in Germany? To answer this question, we will first examine the effects of the introduction of the debt brake on the German federal states in the period 2010-16. For this purpose, the observed consolidation performance and the consolidation incentive or pressure experienced by the federal states were evaluated with the help of a scorecard specifically developed for this purpose. Multiple regression analysis was used to analyze how the scorecard factors affect the consolidation performance of the federal states. It found that nearly 90\% of the variation was explained by the independent variables budgetary position, debt burden, revenue growth and pension burden. Thus the debt brake likely played a subordinate role in the 2009-2016 consolidation episode. Subsequently, the data collected in 65 expert interviews was used to analyze the limits of the new fiscal rule, and to determine which potential risks could hinder or prevent the debt brake in the future: municipal debt, FEUs, contingent liabilities in the form of guarantees for financial institutions and pension obligations. The frequently expressed criticism that the debt brake impedes economic growth and public investments is also reviewed and rejected. Finally, we discuss potential future developments regarding the debt brake and the German public administration as well as future consolidation efforts of the L{\"a}nder.},
  language  = {de}
}
@phdthesis{AriasAndres2018,
  author    = {Arias Andr{\´e}s, Mar{\´i}a de Jes{\´u}s},
  title     = {Microbial gene exchange on microplastic particles},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417241},
  school      = {Universit{\"a}t Potsdam},
  pages     = {94},
  year      = {2018},
  abstract  = {Plastic pollution is ubiquitous on the planet since several millions of tons of plastic waste enter aquatic ecosystems each year. Furthermore, the amount of plastic produced is expected to increase exponentially shortly. The heterogeneity of materials, additives and physical characteristics of plastics are typical of these emerging contaminants and affect their environmental fate in marine and freshwaters. Consequently, plastics can be found in the water column, sediments or littoral habitats of all aquatic ecosystems. Most of this plastic debris will fragment as a product of physical, chemical and biological forces, producing particles of small size. These particles (< 5mm) are known as "microplastics" (MP). Given their high surface-to-volume ratio, MP stimulate biofouling and the formation of biofilms in aquatic systems. As a result of their unique structure and composition, the microbial communities in MP biofilms are referred to as the "Plastisphere." While there is increasing data regarding the distinctive composition and structure of the microbial communities that form part of the plastisphere, scarce information exists regarding the activity of microorganisms in MP biofilms. This surface-attached lifestyle is often associated with the increase in horizontal gene transfer (HGT) among bacteria. Therefore, this type of microbial activity represents a relevant function worth to be analyzed in MP biofilms. The horizontal exchange of mobile genetic elements (MGEs) is an essential feature of bacteria. It accounts for the rapid evolution of these prokaryotes and their adaptation to a wide variety of environments. The process of HGT is also crucial for spreading antibiotic resistance and for the evolution of pathogens, as many MGEs are known to contain antibiotic resistance genes (ARGs) and genetic determinants of pathogenicity. In general, the research presented in this Ph.D. thesis focuses on the analysis of HGT and heterotrophic activity in MP biofilms in aquatic ecosystems. The primary objective was to analyze the potential of gene exchange between MP bacterial communities vs. that of the surrounding water, including bacteria from natural aggregates. Moreover, the thesis addressed the potential of MP biofilms for the proliferation of biohazardous bacteria and MGEs from wastewater treatment plants (WWTPs) and associated with antibiotic resistance. Finally, it seeks to prove if the physiological profile of MP biofilms under different limnological conditions is divergent from that of the water communities. Accordingly, the thesis is composed of three independent studies published in peer-reviewed journals. The two laboratory studies were performed using both model and environmental microbial communities. In the field experiment, natural communities from freshwater ecosystems were examined. In Chapter I, the inflow of treated wastewater into a temperate lake was simulated with a concentration gradient of MP particles. The effects of MP on the microbial community structure and the occurrence of integrase 1 (int 1) were followed. The int 1 is a marker associated with mobile genetic elements and known as a proxy for anthropogenic effects on the spread of antimicrobial resistance genes. During the experiment, the abundance of int1 increased in the plastisphere with increasing MP particle concentration, but not in the surrounding water. In addition, the microbial community on MP was more similar to the original wastewater community with increasing microplastic concentrations. Our results show that microplastic particles indeed promote persistence of standard indicators of microbial anthropogenic pollution in natural waters. In Chapter II, the experiments aimed to compare the permissiveness of aquatic bacteria towards model antibiotic resistance plasmid pKJK5, between communities that form biofilms on MP vs. those that are free-living. The frequency of plasmid transfer in bacteria associated with MP was higher when compared to bacteria that are free-living or in natural aggregates. Moreover, comparison increased gene exchange occurred in a broad range of phylogenetically-diverse bacteria. The results indicate a different activity of HGT in MP biofilms, which could affect the ecology of aquatic microbial communities on a global scale and the spread of antibiotic resistance. Finally, in Chapter III, physiological measurements were performed to assess whether microorganisms on MP had a different functional diversity from those in water. General heterotrophic activity such as oxygen consumption was compared in microcosm assays with and without MP, while diversity and richness of heterotrophic activities were calculated by using Biolog® EcoPlates. Three lakes with different nutrient statuses presented differences in MP-associated biomass build up. Functional diversity profiles of MP biofilms in all lakes differed from those of the communities in the surrounding water, but only in the oligo-mesotrophic lake MP biofilms had a higher functional richness compared to the ambient water. The results support that MP surfaces act as new niches for aquatic microorganisms and can affect global carbon dynamics of pelagic environments. Overall, the experimental works presented in Chapters I and II support a scenario where MP pollution affects HGT dynamics among aquatic bacteria. Among the consequences of this alteration is an increase in the mobilization and transfer efficiency of ARGs. Moreover, it supposes that changes in HGT can affect the evolution of bacteria and the processing of organic matter, leading to different catabolic profiles such as demonstrated in Chapter III. The results are discussed in the context of the fate and magnitude of plastic pollution and the importance of HGT for bacterial evolution and the microbial loop, i.e., at the base of aquatic food webs. The thesis supports a relevant role of MP biofilm communities for the changes observed in the aquatic microbiome as a product of intense human intervention.},
  language  = {en}
}
@phdthesis{Kettner2018,
  author    = {Kettner, Marie Therese},
  title     = {Microbial colonization of microplastic particles in aquatic systems},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418854},
  school      = {Universit{\"a}t Potsdam},
  pages     = {139},
  year      = {2018},
  abstract  = {The continuously increasing pollution of aquatic environments with microplastics (plastic particles < 5 mm) is a global problem with potential implications for organisms of all trophic levels. For microorganisms, trillions of these floating microplastics particles represent a huge surface area for colonization. Due to the very low biodegradability, microplastics remain years to centuries in the environment and can be transported over thousands of kilometers together with the attached organisms. Since also pathogenic, invasive, or otherwise harmful species could be spread this way, it is essential to study microplastics-associated communities. For this doctoral thesis, eukaryotic communities were analyzed for the first time on microplastics in brackish environments and compared to communities in the surrounding water and on the natural substrate wood. With Illumina MiSeq high-throughput sequencing, more than 500 different eukaryotic taxa were detected on the microplastics samples. Among them were various green algae, dinoflagellates, ciliates, fungi, fungal-like protists and small metazoans such as nematodes and rotifers. The most abundant organisms was a dinoflagellate of the genus Pfiesteria, which could include fish pathogenic and bloom forming toxigenic species. Network analyses revealed that there were numerous interaction possibilities among prokaryotes and eukaryotes in microplastics biofilms. Eukaryotic community compositions on microplastics differed significantly from those on wood and in water, and compositions were additionally distinct among the sampling locations. Furthermore, the biodiversity was clearly lower on microplastics in comparison to the diversity on wood or in the surrounding water. In another experiment, a situation was simulated in which treated wastewater containing microplastics was introduced into a freshwater lake. With increasing microplastics concentrations, the resulting bacterial communities became more similar to those from the treated wastewater. Moreover, the abundance of integrase I increased together with rising concentrations of microplastics. Integrase I is often used as a marker for anthropogenic environmental pollution and is further linked to genes conferring, e.g., antibiotic resistance. This dissertation gives detailed insights into the complexity of prokaryotic and eukaryotic communities on microplastics in brackish and freshwater systems. Even though microplastics provide novel microhabitats for various microbes, they might also transport toxigenic, pathogenic, antibiotic-resistant or parasitic organisms; meaning their colonization can pose potential threats to humans and the environment. Finally, this thesis explains the urgent need for more research as well as for strategies to minimize the global microplastic pollution.},
  language  = {en}
}
@phdthesis{Ion2018,
  author    = {Ion, Alexandra},
  title     = {Metamaterial devices},
  doi       = {10.25932/publishup-42986},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-429861},
  school      = {Universit{\"a}t Potsdam},
  pages     = {x, 173},
  year      = {2018},
  abstract  = {Digital fabrication machines such as 3D printers excel at producing arbitrary shapes, such as for decorative objects. In recent years, researchers started to engineer not only the outer shape of objects, but also their internal microstructure. Such objects, typically based on 3D cell grids, are known as metamaterials. Metamaterials have been used to create materials that, e.g., change their volume, or have variable compliance. While metamaterials were initially understood as materials, we propose to think of them as devices. We argue that thinking of metamaterials as devices enables us to create internal structures that offer functionalities to implement an input-process-output model without electronics, but purely within the material's internal structure. In this thesis, we investigate three aspects of such metamaterial devices that implement parts of the input-process-output model: (1) materials that process analog inputs by implementing mechanisms based on their microstructure, (2) that process digital signals by embedding mechanical computation into the object's microstructure, and (3) interactive metamaterial objects that output to the user by changing their outside to interact with their environment. The input to our metamaterial devices is provided directly by the users interacting with the device by means of physically pushing the metamaterial, e.g., turning a handle, pushing a button, etc. The design of such intricate microstructures, which enable the functionality of metamaterial devices, is not obvious. The complexity of the design arises from the fact that not only a suitable cell geometry is necessary, but that additionally cells need to play together in a well-defined way. To support users in creating such microstructures, we research and implement interactive design tools. These tools allow experts to freely edit their materials, while supporting novice users by auto-generating cells assemblies from high-level input. Our tools implement easy-to-use interactions like brushing, interactively simulate the cell structures' deformation directly in the editor, and export the geometry as a 3D-printable file. Our goal is to foster more research and innovation on metamaterial devices by allowing the broader public to contribute.},
  language  = {en}
}
@phdthesis{anHaack2018,
  author    = {an Haack, Jan},
  title     = {Market and affect in evangelical mission},
  doi       = {10.25932/publishup-42469},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-424694},
  school      = {Universit{\"a}t Potsdam},
  pages     = {viii, 240},
  year      = {2018},
  abstract  = {This text is a contribution to the research on the worldwide success of evangelical Christianity and offers a new perspective on the relationship between late modern capitalism and evangelicalism. For this purpose, the utilization of affect and emotion in evangelicalism towards the mobilization of its members will be examined in order to find out what similarities to their employment in late modern capitalism can be found. Different examples from within the evangelical spectrum will be analyzed as affective economies in order to elaborate how affective mobilization is crucial for evangelicalism's worldwide success. Pivotal point of this text is the exploration of how evangelicalism is able to activate the voluntary commitment of its members, financiers, and missionaries. Gathered here are examples where both spheres—evangelicalism and late modern capitalism—overlap and reciprocate, followed by a theoretical exploration of how the findings presented support a view of evangelicalism as an inner-worldly narcissism that contributes to an assumed re-enchantment of the world.},
  language  = {en}
}
@phdthesis{Hintsche2018,
  author    = {Hintsche, Marius},
  title     = {Locomotion of a bacterium with a polar bundle of flagella},
  doi       = {10.25932/publishup-42697},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-426972},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xi, 108},
  year      = {2018},
  abstract  = {Movement and navigation are essential for many organisms during some parts of their lives. This is also true for bacteria, which can move along surfaces and swim though liquid environments. They are able to sense their environment, and move towards environmental cues in a directed fashion. These abilities enable microbial lifecyles in biofilms, improved food uptake, host infection, and many more. In this thesis we study aspects of the swimming movement - or motility - of the soil bacterium (P. putida). Like most bacteria, P. putida swims by rotating its helical flagella, but their arrangement differs from the main model organism in bacterial motility research: (E. coli). P. putida is known for its intriguing motility strategy, where fast and slow episodes can occur after each other. Up until now, it was not known how these two speeds can be produced, and what advantages they might confer to this bacterium. Normally the flagella, the main component of thrust generation in bacteria, are not observable by ordinary light microscopy. In order to elucidate this behavior, we therefore used a fluorescent staining technique on a mutant strain of this species to specifically label the flagella, while leaving the cell body only faintly stained. This allowed us to image the flagella of the swimming bacteria with high spacial and temporal resolution with a customized high speed fluorescence microscopy setup. Our observations show that P. putida can swim in three different modes. First, It can swim with the flagella pushing the cell body, which is the main mode of swimming motility previously known from other bacteria. Second, it can swim with the flagella pulling the cell body, which was thought not to be possible in situations with multiple flagella. Lastly, it can wrap its flagellar bundle around the cell body, which results in a speed wich is slower by a factor of two. In this mode, the flagella are in a different physical conformation with a larger radius so the cell body can fit inside. These three swimming modes explain the previous observation of two speeds, as well as the non strict alternation of the different speeds. Because most bacterial swimming in nature does not occur in smoothly walled glass enclosures under a microscope, we used an artificial, microfluidic, structured system of obstacles to study the motion of our model organism in a structured environment. Bacteria were observed in microchannels with cylindrical obstacles of different sizes and with different distances with video microscopy and cell tracking. We analyzed turning angles, run times, and run length, which we compared to a minimal model for movement in structured geometries. Our findings show that hydrodynamic interactions with the walls lead to a guiding of the bacteria along obstacles. When comparing the observed behavior with the statics of a particle that is deflected with every obstacle contact, we find that cells run for longer distances than that model. Navigation in chemical gradients is one of the main applications of motility in bacteria. We studied the swimming response of P. putida cells to chemical stimuli (chemotaxis) of the common food preservative sodium benzoate. Using a microfluidic gradient generation device, we created gradients of varying strength, and observed the motion of cells with a video microscope and subsequent cell tracking. Analysis of different motility parameters like run lengths and times, shows that P. putida employs the classical chemotaxis strategy of E. coli: runs up the gradient are biased to be longer than those down the gradient. Using the two different run speeds we observed due to the different swimming modes, we classify runs into `fast' and `slow' modes with a Gaussian mixture model (GMM). We find no evidence that P. putida's uses its swimming modes to perform chemotaxis. In most studies of bacterial motility, cell tracking is used to gather trajectories of individual swimming cells. These trajectories then have to be decomposed into run sections and tumble sections. Several algorithms have been developed to this end, but most require manual tuning of a number of parameters, or extensive measurements with chemotaxis mutant strains. Together with our collaborators, we developed a novel motility analysis scheme, based on generalized Kramers-Moyal-coefficients. From the underlying stochastic model, many parameters like run length etc., can be inferred by an optimization procedure without the need for explicit run and tumble classification. The method can, however, be extended to a fully fledged tumble classifier. Using this method, we analyze E. coli chemotaxis measurements in an aspartate analog, and find evidence for a chemotactic bias in the tumble angles.},
  language  = {en}
}
@phdthesis{Feldmann2018,
  author    = {Feldmann, David},
  title     = {Light-driven diffusioosmosis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417184},
  school      = {Universit{\"a}t Potsdam},
  pages     = {viii, 150},
  year      = {2018},
  abstract  = {The emergence of microfluidics created the need for precise and remote control of micron-sized objects. I demonstrate how light-sensitive motion can be induced at the micrometer scale by a simple addition of a photosensitive surfactant, which makes it possible to trigger hydrophobicity with light. With point-like laser irradiation, radial inward and outward hydrodynamic surface flows are remotely switched on and off. In this way, ensembles of microparticles can be moved toward or away from the irradiation center. Particle motion is analyzed according to varying parameters, such as surfactant and salt concentration, illumination condition, surface hydrophobicity, and surface structure. The physical origin of this process is the so-called light-driven diffusioosmosis (LDDO), a phenomenon that was discovered in the framework of this thesis and is described experimentally and theoretically in this work. To give a brief explanation, a focused light irradiation induces a local photoisomerization that creates a concentration gradient at the solid-liquid interface. To compensate for the change in osmotic pressure near the surface, a hydrodynamic flow along the surface is generated. Surface-surfactant interaction largely governs LDDO. It is shown that surfactant adsorption depends on the isomerization state of the surfactant. Photoisomerization, therefore, triggers a surfactant attachment or detachment from the surface. This change is considered to be one of the reasons for the formation of LDDO flow. These flows are introduced not only by a focused laser source but also by global irradiation. Porous particles show reversible repulsive and attractive interactions when dispersed in the solution of photosensitive surfactant. Repulsion and attraction is controlled by the irradiation wavelength. Illumination with red light leads to formation of aggregates, while illumination with blue light leads to the formation of a well-separated grid with equal interparticle distances, between 2µm and 80µm, depending on the particle surface density. These long-range interactions are considered to be a result of an increase or decrease of surfactant concentration around each particle, depending on the irradiation wavelength. Surfactant molecules adsorb inside the pores of the particles. A light-induced photoisomerization changes adsorption to the pores and drives surfactant molecules to the outside. The concentration gradients generate symmetric flows around each single particle resulting in local LDDO. With a break of the symmetry (i.e., by closing one side of the particle with a metal cap), one can achieve active self-propelled particle motion.},
  language  = {en}
}
@phdthesis{Schukraft2018,
  author    = {Schukraft, Stefan},
  title     = {Legislativer Konflikt in den deutschen L{\"a}ndern},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-450-0},
  doi       = {10.25932/publishup-42216},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-422162},
  school      = {Universit{\"a}t Potsdam},
  pages     = {563},
  year      = {2018},
  abstract  = {Gesetzgebungsmehrheiten in parlamentarischen Systemen mit ihrem Dualismus aus Regierungslager und Oppositionsparteien bilden sich nicht frei. Vielmehr findet ihre Koordination in einem Spannungsfeld aus den programmatischen Positionen der Akteure und ihrem opportunistischen Wettbewerb untereinander statt. Diese Problematik bricht die Arbeit auf drei konkrete Fragestellungen herunter, im Rahmen derer sie die Konfliktmuster zwischen Akteuren bei der legislativen Mehrheitskoordination unter Mehrheitsregierungen in den deutschen Landesparlamenten untersucht: 1) Inwieweit h{\"a}ngt es von programmatischen Positionen oder vom opportunistischen Wettbewerb des Neuen Dualismus zwischen Regierungslager und Oppositionsparteien ab, ob Oppositionsparteien und Regierungslager bei der Bildung von Gesetzgebungsmehrheiten kooperieren oder konfligieren? 2) Inwieweit kommt es vor dem Hintergrund unterschiedlicher programmatischer Positionen und opportunistischer {\"U}berlegungen zu Konflikt statt Kooperation zwischen Koalitionsakteuren bei der Bildung gemeinsamer Gesetzgebungsmehrheiten? Letztere Fragestellung wird sodann auch in den Kontext des bundesrepublikanischen Kooperativf{\"o}deralismus eingebettet: 3) Inwieweit geht die Bildung von Gesetzgebungsmehrheiten bei der Ausf{\"u}hrung von Bundesgesetzen in Mischkoalitionen (bestehend aus Parteien, die sich auf Bundesebene in konkurrierenden Lagern gegen{\"u}berstehen) mit mehr Konflikt einher als in ebenen{\"u}bergreifend kongruenten Regierungskoalitionen? Theoretisch wird ein rationalistisches Modell der grundlegenden Handlungsanreize bei der Bildung von Gesetzgebungsmehrheiten in den deutschen Landesparlamenten erarbeitet. Auf dieser Basis besch{\"a}ftigt sich die Arbeit damit, wie die Akteure strategisch programmatische und opportunistische Anreize zu Konflikt und Kooperation abw{\"a}gen. Die Arbeit leitet dann konkrete Determinanten ab, die vorwiegend - aber nicht nur - mittels quantitativer Methoden getestet werden. Die Arbeit st{\"u}tzt sich dabei auf eine gr{\"o}ßtenteils neu zusammengestellte Gesetzgebungsdatenbank aus 3.359 Gesetzgebungsvorg{\"a}ngen aus 23 Legislaturperioden zwischen 1990 und 2013 in den L{\"a}ndern Hamburg, Hessen, Mecklenburg-Vorpommern, Nordrhein-Westfalen und Sachsen-Anhalt. Die Analyse der Konfliktmuster zwischen Oppositionsparteien und Regierungslager zeigt, dass programmatische Distanz einer Oppositionspartei zum Regierungslager f{\"u}r Oppositionsverhalten eine Rolle spielt; dies gilt jedoch auch f{\"u}r opportunistische Aspekte (so l{\"a}sst sich beispielsweise ein kompetitiveres Oppositionsverhalten beobachten, wenn nach der letzten Wahl ein vollst{\"a}ndiger Regierungswechsel erfolgte). Oppositionsverhalten erscheint dabei recht kleinteilig ausgepr{\"a}gt. Neben Unterschieden zwischen Legislaturperioden treten solche auch innerhalb von Legislaturperioden zwischen Akteuren sowie zwischen Gesetzentw{\"u}rfen auf. Die Analyse generellen Koalitionskonflikts weist darauf hin, dass ein nicht unerheblicher Teil von Koalitionskonflikt strukturell bedingt ist. Handelt es sich bei einer gebildeten Regierungskoalition um die Wunschkoalition der beteiligten Parteien, so ist dies Koalitionskonflikt abtr{\"a}glich. Selbiges gilt f{\"u}r eine gr{\"o}ßere Mehrheitsmarge des Regierungslagers. Dar{\"u}ber hinaus ergeben sich Hinweise, dass die Ausf{\"u}hrung von Bundesgesetzen unter Mischkoalitionen bei bundespolitischer Abgrenzung der Koalitionspartner mit mehr Koalitionskonflikt einhergeht als eine Ausf{\"u}hrung unter kongruenten Koalitionen. Der Beitrag der Arbeit ist polymorph angelegt. Sie hilft zun{\"a}chst, die Strategien von Akteuren im Gesetzgebungsprozess besser zu verstehen. Als normativer Beitrag tritt auf einer zweiten Ebene die bessere Erforschung etwaiger nachteiliger Effekte des Neuen Dualismus unter Mehrheitsregierungen hinzu. Gleichzeitig soll die Arbeit drittens in der Zusammenschau helfen, die Mechanik der parlamentarischen Systeme in den L{\"a}ndern selbst zu erhellen und besser normativ bewerten zu k{\"o}nnen. Hintergrund sind hier die jahrzehntealten Debatten um das beste Regierungssystem und -format der deutschen L{\"a}nder als subnationale Entit{\"a}ten. Die dritte Fragestellung dieser Arbeit konnte diese Debatte zudem mit einem neuen Aspekt bereichern. Wissen dar{\"u}ber, inwieweit die Ausf{\"u}hrung von Bundesgesetzen in den L{\"a}ndern je nach ebenen{\"u}bergreifendem Koalitionsmuster in unterschiedlichem Ausmaß mit einem ‚coalition governance'-Problem verbunden ist, f{\"u}gt der Forschung zum f{\"o}deralen Entscheiden in der Bundesrepublik eine neue und beachtenswerte Facette hinzu. Denn dabei handelt es sich um eine f{\"o}deral bedingte mechanische Beeintr{\"a}chtigung der Mehrheitskoordination in den Landesparlamenten selbst, die die potenziell gegebene f{\"o}derale Flexibilit{\"a}t bei der Ausf{\"u}hrung von Bundesgesetzen hemmt. Dies ebnet den Weg zu neuen Debatten dar{\"u}ber, wie in den deutschen L{\"a}ndern mehr legislative Abstimmungsflexibilit{\"a}t erm{\"o}glicht werden kann als unter den bisher {\"u}blichen Mehrheits-Koalitionsregierungen.},
  language  = {de}
}
@phdthesis{Oeztuerk2018,
  author    = {{\"O}zt{\"u}rk, Ugur},
  title     = {Learning more to predict landslides},
  doi       = {10.25932/publishup-42643},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-426439},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxi, 104},
  year      = {2018},
  abstract  = {Landslides are frequent natural hazards in rugged terrain, when the resisting frictional force of the surface of rupture yields to the gravitational force. These forces are functions of geological and morphological factors, such as angle of internal friction, local slope gradient or curvature, which remain static over hundreds of years; whereas more dynamic triggering events, such as rainfall and earthquakes, compromise the force balance by temporarily reducing resisting forces or adding transient loads. This thesis investigates landslide distribution and orientation due to landslide triggers (e.g. rainfall) at different scales (6-4∙10^5 km^2) and aims to link rainfall movement with the landslide distribution. It additionally explores the local impacts of the extreme rainstorms on landsliding and the role of precursory stability conditions that could be induced by an earlier trigger, such as an earthquake. Extreme rainfall is a common landslide trigger. Although several studies assessed rainfall intensity and duration to study the distribution of thus triggered landslides, only a few case studies quantified spatial rainfall patterns (i.e. orographic effect). Quantifying the regional trajectories of extreme rainfall could aid predicting landslide prone regions in Japan. To this end, I combined a non-linear correlation metric, namely event synchronization, and radial statistics to assess the general pattern of extreme rainfall tracks over distances of hundreds of kilometers using satellite based rainfall estimates. Results showed that, although the increase in rainfall intensity and duration positively correlates with landslide occurrence, the trajectories of typhoons and frontal storms were insufficient to explain landslide distribution in Japan. Extreme rainfall trajectories inclined northwestwards and were concentrated along some certain locations, such as coastlines of southern Japan, which was unnoticed in the landslide distribution of about 5000 rainfall-triggered landslides. These landslides seemed to respond to the mean annual rainfall rates. Above mentioned findings suggest further investigation on a more local scale to better understand the mechanistic response of landscape to extreme rainfall in terms of landslides. On May 2016 intense rainfall struck southern Germany triggering high waters and landslides. The highest damage was reported at the Braunsbach, which is located on the tributary-mouth fan formed by the Orlacher Bach. Orlacher Bach is a ~3 km long creek that drains a catchment of about ~6 km^2. I visited this catchment in June 2016 and mapped 48 landslides along the creek. Such high landslide activity was not reported in the nearby catchments within ~3300 km^2, despite similar rainfall intensity and duration based on weather radar estimates. My hypothesis was that several landslides were triggered by rainfall-triggered flash floods that undercut hillslope toes along the Orlacher Bach. I found that morphometric features such as slope and curvature play an important role in landslide distribution on this micro scale study site (<10 km^2). In addition, the high number of landslides along the Orlacher Bach could also be boosted by accumulated damages on hillslopes due karst weathering over longer time scales. Precursory damages on hillslopes could also be induced by past triggering events that effect landscape evolution, but this interaction is hard to assess independently from the latest trigger. For example, an earthquake might influence the evolution of a landscape decades long, besides its direct impacts, such as landslides that follow the earthquake. Here I studied the consequences of the 2016 Kumamoto Earthquake (MW 7.1) that triggered some 1500 landslides in an area of ~4000 km^2 in central Kyushu, Japan. Topography, i.e. local slope and curvature, both amplified and attenuated seismic waves, thus controlling the failure mechanism of those landslides (e.g. progressive). I found that topography fails in explaining the distribution and the preferred orientation of the landslides after the earthquake; instead the landslides were concentrated around the northeast of the rupture area and faced mostly normal to the rupture plane. This preferred location of the landslides was dominated mainly by the directivity effect of the strike-slip earthquake, which is the propagation of wave energy along the fault in the rupture direction; whereas amplitude variations of the seismic radiation altered the preferred orientation. I suspect that the earthquake directivity and the asymmetry of seismic radiation damaged hillslopes at those preferred locations increasing landslide susceptibility. Hence a future weak triggering event, e.g. scattered rainfall, could further trigger landslides at those damaged hillslopes.},
  language  = {en}
}
@phdthesis{Ott2018,
  author    = {Ott, Florian},
  title     = {Late Glacial and Holocene climate and environmental evolution in the southern Baltic lowlands derived from varved lake sediments},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414805},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xix, 241},
  year      = {2018},
  abstract  = {Holocene climate variability is generally characterized by low frequency changes than compared to the last glaciations including the Lateglacial. However, there is vast evidence for decadal to centennial scale oscillations and millennial scale climate trends, which are within and beyond a human lifetime perception, respectively. Within the Baltic realm, a transitional zone between oceanic and continental climate influence, the impact of Holocene and Lateglacial climate and environmental change is currently partly understood. This is mainly attributed to the scarcity of well-dated and high-resolution sediment records and to the lacking continuity of already investigated archives. The aim of this doctoral thesis is to reconstruct Holocene and Late Glacial climate variability on local to (over)regional scales based on varved (annually laminated) sediments from Lake Czechowskie down to annual resolution. This project was carried out within the Virtual Institute for Integrated Climate and Landscape Evolution Analyses (ICLEA) and funded by the Helmholtz Association and the Helmholtz Climate Initiative REKLIM (Regional Climate Change). ICLEA intended to gain a better understanding of climate variability and landscape evolution processes in the Northern Central European lowlands since the last deglaciation. REKLIM Topic 8 "Abrupt climate change derived from proxy data" aims at identifying spatiotemporal patterns of climate variability between e.g. higher and lower latitudes. The main aim of this thesis was (i) to establish a robust chronology based on a multiple dating approach for Lake Czechowskie covering the Late Glacial and Holocene and for the Trzechowskie palaeolake for the Lateglacial, respectively, (ii) to reconstruct past climatic and environmental conditions on centennial to multi-millennial time scales and (iii) to distinguish between local to regional different sediments responses to climate change. Addressing the first aim, the Lake Czechowskie chronology has been established by a multiple dating approach comprising information from varve counting, tephrochronology, AMS 14C dating of terrestrial plant remains, biostratigraphy and 137Cs activity concentration measurements. Those independent age constraints covering the Lateglacial and the entire Holocene and have been further implemented in a Bayesian age model by using OxCal v.4.2. Thus, even within non-varved sediment intervals, robust chronological information has been used for absolute age determination. The identification of five cryptotephras, of which three are used as unambiguous isochrones, is furthermore a significant improvement of the Czechowskie chronology and currently unique for the Holocene within Poland. The first findings of coexisting early Holocene H{\"a}sseldalen and Askja-S cryptotephras within a varved sequence even allowed differential dating between both volcanic ashes and stimulated the discussion of revising the absolute ages of the Askja-S tephra. The Trzechowskie palaeolake chronology has been established by a multiple dating approach comprising varve counting, tephrochronology, AMS 14C dating of terrestrial plant remains and biostratigraphy, covers the Lateglacial period (Aller{\o}d and Younger Dryas) and has been implemented in OxCal v.4.2. Those age constraints allowed regional correlation to other high-resolution climate archives and identifying leads and lags of proxy responses at the onset of the Younger Dryas. The second aim has been accomplished by detailed micro-facies and geochemical analyses of the Czechowskie sediments for the entire Holocene. Thus, especially micro-facies changes had been linked to enhanced productivity at Lake Czechowskie. Most prominent changes have been recorded at 7.3, 6.5, 4.3 and 2.8 varve kyrs BP and are linked to a stepwise increasing influence of Atlantic air masses. Especially, the mid-Holocene change, which had been widely reported from palaeohydrological records in low latitudes, has been identified and linked to large scale reorganization of atmospheric circulation patterns. Thus, especially long-term changes of climatic and environmental boundary conditions are widely recorded by the Czechowskie sediments. The pronounced response to (multi)millennial scale changes is further corroborated by the lack of clear sediment responses to early Holocene centennial scale climate oscillations (e.g. the Preboreal Oscillation). However, decadal scale changes at Lake Czechowskie during the most recent period (last 140 years) have been investigated in a lake comparison study. To fulfill the third aim of the doctoral thesis, three lakes in close vicinity to each other have been investigated in order to better distinguish how local, site-specific parameters, may superimpose regional climate driven changes. All lakes haven been unambiguously linked by the Askja AD1875 cryptotephra and independent varve chronologies. As a result, climate warming has only been recorded by sedimentation changes at the smallest and best sheltered lake (Głęboczek), whereas the largest lake (Czechowskie) and the shallowest lake (Jelonek) showed attenuated and less clear sediment responses, respectively. The different responses have been linked to morphological lake characteristics (lake size and depth, catchment area). This study highlights the potential of high-resolution lake comparison for robust proxy based climate reconstructions. In summary, the doctoral thesis presents a high-resolution sediment record with an underlying age model, which is prerequisite for unprecedented age control down to annual resolution. Sediment proxy based climate reconstructions demonstrate the importance of the Czechowskie sediments for better understanding climate variability in the southern Baltic realm. Case studies showed the clear response on millennial time scale, while decadal scale fluctuations are either less well expressed or superimposed by local, site-specific parameters. The identification of volcanic ash layers is not only used for unambiguous isochrones, those are key tie lines for local to supra regional archive synchronization and establish the Lake Czechowskie as a key climate archive.},
  language  = {en}
}
@phdthesis{Eugster2018,
  author    = {Eugster, Patricia},
  title     = {Landscape evolution in the western Indian Himalaya since the Miocene},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420329},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XXI, 208},
  year      = {2018},
  abstract  = {The Himalayan arc stretches >2500 km from east to west at the southern edge of the Tibetan Plateau, representing one of the most important Cenozoic continent-continent collisional orogens. Internal deformation processes and climatic factors, which drive weathering, denudation, and transport, influence the growth and erosion of the orogen. During glacial times wet-based glaciers sculpted the mountain range and left overdeepend and U-shaped valleys, which were backfilled during interglacial times with paraglacial sediments over several cycles. These sediments partially still remain within the valleys because of insufficient evacuation capabilities into the foreland. Climatic processes overlay long-term tectonic processes responsible for uplift and exhumation caused by convergence. Possible processes accommodating convergence within the orogenic wedge along the main Himalayan faults, which divide the range into four major lithologic units, are debated. In this context, the identification of processes shaping the Earth's surface on short- and on long-term are crucial to understand the growth of the orogen and implications for landscape development in various sectors along the arc. This thesis focuses on both surface and tectonic processes that shape the landscape in the western Indian Himalaya since late Miocene. In my first study, I dated well-preserved glacially polished bedrock on high-elevated ridges and valley walls in the upper of the Chandra Valley the by means of 10Be terrestrial cosmogenic radionuclides (TCN). I used these ages and mapped glacial features to reconstruct the extent and timing of Pleistocene glaciation at the southern front of the Himalaya. I was able to reconstruct an extensive valley glacier of ~200 km length and >1000 m thickness. Deglaciation of the Chandra Valley glacier started subsequently to insolation increase on the Northern Hemisphere and thus responded to temperature increase. I showed that the timing this deglaciation onset was coeval with retreat of further midlatitude glaciers on the Northern and Southern Hemispheres. These comparisons also showed that the post-LGM deglaciation very rapid, occurred within a few thousand years, and was nearly finished prior to the B{\o}lling/Aller{\o}d interstadial. A second study (co-authorship) investigates how glacial advances and retreats in high mountain environments impact the landscape. By 10Be TCN dating and geomorphic mapping, we obtained maximal length and height of the Siachen Glacier within the Nubra Valley. Today the Shyok and Nubra confluence is backfilled with sedimentary deposits, which are attributed to the valley blocking of the Siachen Glacier 900 m above the present day river level. A glacial dam of the Siachen Glacier blocked the Shyok River and lead to the evolution of a more than 20 km long lake. Fluvial and lacustrine deposits in the valley document alternating draining and filling cycles of the lake dammed by the Siachen Glacier. In this study, we can show that glacial incision was outpacing fluvial incision. In the third study, which spans the million-year timescale, I focus on exhumation and erosion within the Chandra and Beas valleys. In this study the position and discussed possible reasons of rapidly exhuming rocks, several 100-km away from one of the main Himalayan faults (MFT) using Apatite Fission Track (AFT) thermochronometry. The newly gained AFT ages indicate rapid exhumation and confirm earlier studies in the Chandra Valley. I assume that the rapid exhumation is most likely related to uplift over subsurface structures. I tested this hypothesis by combining further low-temperature thermochronometers from areas east and west of my study area. By comparing two transects, each parallel to the Beas/Chandra Valley transect, I demonstrate similarities in the exhumation pattern to transects across the Sutlej region, and strong dissimilarities in the transect crossing the Dhauladar Range. I conclude that the belt of rapid exhumation terminates at the western end of the Kullu-Rampur window. Therewith, I corroborate earlier studies suggesting changes in exhumation behavior in the western Himalaya. Furthermore, I discussed several causes responsible for the pronounced change in exhumation patterns along strike: 1) the role of inherited pre-collisional features such as the Proterozoic sedimentary cover of the Indian basement, former ridges and geological structures, and 2) the variability of convergence rates along the Himalayan arc due to an increased oblique component towards the syntaxis. The combination of field observations (geological and geomorphological mapping) and methods to constrain short- and long-term processes (10Be, AFT) help to understand the role of the individual contributors to exhumation and erosion in the western Indian Himalaya. With the results of this thesis, I emphasize the importance of glacial and tectonic processes in shaping the landscape by driving exhumation and erosion in the studied areas.},
  language  = {en}
}
@phdthesis{HerreraBorquez2018,
  author    = {Herrera Borquez, Kenya},
  title     = {La cabrona aqu{\´i} soy yo},
  doi       = {10.25932/publishup-42368},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-423686},
  school      = {Universit{\"a}t Potsdam},
  pages     = {277},
  year      = {2018},
  abstract  = {La {\´u}ltima d{\´e}cada ha visto un inter{\´e}s creciente en el fen{\´o}meno del narcotr{\´a}fico en M{\´e}xico a nivel global. Las diversas expresiones de violencia extrema que acompa{\~n}an al negocio ilegal de drogas se narran en artefactos medi{\´a}ticos que provocan fascinaci{\´o}n e intriga. As{\´i}, la literatura y el cine, la m{\´u}sica y la televisi{\´o}n presentan im{\´a}genes e historias sobre el narcotr{\´a}fico que alimentan el imaginario colectivo. En este contexto, a nivel global hay representaciones medi{\´a}ticas de la mujer mexicana narcotraficante que reproducen estereotipos femeninos donde la mujer se cosifica, exagerando los atributos sexuales del cuerpo de las mujeres. Esta representaci{\´o}n cultural hace de la mujer un objeto de deseo, cuya belleza sirve como una marca de prestigio y ostentaci{\´o}n para el hombre narcotraficante. La cultura del narcotr{\´a}fico impone a las mujeres un ideal est{\´e}tico particular distintivo, que las mujeres reproducen meticulosamente para emular esta representaci{\´o}n. Aunado a la belleza f{\´i}sica, la mujer es retratada violenta y sin escr{\´u}pulos, usa su belleza y poder de seducci{\´o}n para acumular dinero y poder a costa de los hombres que conquista. Para los que no pertenecen al mundo del narcotr{\´a}fico, este tipo de mujer, hipersexualizada, inspira juicios negativos, discriminaci{\´o}n, desconfianza y temor. La intenci{\´o}n de la pregunta y objetivos de investigaci{\´o}n de este trabajo fue rebasar estas representaciones para observar las complejidades de las experiencias de vida de estas mujeres. El prop{\´o}sito de esta tesis de doctorado fue explorar c{\´o}mo cambian las vidas de las mujeres mexicanas cuando se involucran en la narcocultura, en la frontera M{\´e}xico-Estados Unidos. En espec{\´i}fico, la investigaci{\´o}n analiz{\´o} las transformaciones en la corporalidad y en las subjetividades de estas mujeres, y c{\´o}mo estas transformaciones influ{\´i}an en el lugar que ocupan en el espacio social y cultural que configura el narcotr{\´a}fico. Adem{\´a}s, se analiz{\´o} qu{\´e} m{\´a}rgenes de negociaci{\´o}n tienen las mujeres en la narcocultura, para poder actuar y definirse a s{\´i} mismas. Las preguntas que guiaron el trabajo indagaban sobre c{\´o}mo las mujeres cambiaban su cuerpo para encarnar el ideal est{\´e}tico y qu{\´e} significados se atribu{\´i}an a estos cambios. Fue importante analizar qu{\´e} din{\´a}micas de poder se pon{\´i}an en juego a partir de estos cuerpos femeninos, en las relaciones con los hombres y con otras mujeres. Tambi{\´e}n, otro objetivo fue qu{\´e} procesos de subjetivaci{\´o}n operaban en las mujeres que participan en la narcocultura, y qu{\´e} m{\´a}rgenes de negociaci{\´o}n ten{\´i}an para actuar y definirse a s{\´i} mismas. Esta es una investigaci{\´o}n inscrita dentro de los estudios culturales y con una perspectiva feminista interseccional. La investigaci{\´o}n se realiz{\´o} en la frontera mexicana con Estados Unidos, en el noroeste, espec{\´i}ficamente en las ciudades de Mexicali, Tijuana y San Diego, California. La frontera, en esta tesis, se observa como un espacio con m{\´u}ltiples contextos de interpretaci{\´o}n, polis{\´e}mico y heterog{\´e}neo. Estas cualidades hacen que los fen{\´o}menos culturales que ocurren en {\´e}l sean diversos y contradictorios. Para entender los fen{\´o}menos culturales que emergen de la frontera norte de M{\´e}xico, fue {\´u}til el concepto de transfrontera de Jos{\´e} Valenzuela Arce (2014). La propuesta de este acad{\´e}mico es que las transfronteras son "espacios que se niegan a una sola de las condiciones o los lados que la integran" (p. 9). As{\´i}, el concepto habla de los procesos de conectividad y simultaneidad que la globalizaci{\´o}n genera y que redefinen a los Estados-territorio. Al mismo tiempo, habla tambi{\´e}n de los l{\´i}mites que estos mismos Estados utilizan para sostener narrativas nacionales que son "referentes organizadores de adscripciones identitarias y culturales" (p. 18) que crean diferencias y desigualdades. Si esto es as{\´i}, una frontera no se explica completamente desde la demarcaci{\´o}n territorial o desde la diferenciaci{\´o}n jer{\´a}rquica que incluye a algunos y excluye a otros, pero tampoco puede entenderse si nos concentramos solamente en los procesos de hibridaci{\´o}n cultural que ocurren en esos espacios. Por eso, para Valenzuela las fronteras son entre espacios y entre tiempos. Este concepto ayuda a entender c{\´o}mo se intersecta lo global y local en los sistemas semi{\´o}ticos que componen el universo cultural del narcotr{\´a}fico mexicano, al mismo tiempo que explica c{\´o}mo se estructuran mecanismos de exclusi{\´o}n y jerarqu{\´i}as a partir del g{\´e}nero, la posici{\´o}n social y otras marcas de diferenciaci{\´o}n social. En {\´u}ltima instancia, ayuda a localizar estos procesos culturales, materializados en el cuerpo de las mujeres. El concepto de narcocultura tambi{\´e}n fue una herramienta heur{\´i}stica {\´u}til. La cultura aqu{\´i} se entiende como un proceso de producci{\´o}n y reproducci{\´o}n de modelos simb{\´o}licos, materializados en artefactos o representaciones y, adem{\´a}s, interiorizados en l{\´o}gicas de vida, sistemas de valores y creencias, que circulan a trav{\´e}s de las pr{\´a}cticas individuales y colectivas de mujeres y hombres, en contextos hist{\´o}ricos y espaciales espec{\´i}ficos. La narcocultura ser{\´i}a entonces el sistema semi{\´o}tico producido en torno al negocio transnacional de tr{\´a}fico ilegal de drogas, tal como se vive en la frontera norte de M{\´e}xico. La narcocultura, tal como se define en este trabajo es un sistema semi{\´o}tico con l{\´i}mites difusos. As{\´i}, las distinciones entre el mundo ilegal del narcotr{\´a}fico y el mundo de la legalidad externo a este negocio, en el mejor de los casos son borrosas, en el peor, ficticias. La narcocultura trasciende l{\´i}mites territoriales, es un fen{\´o}meno cultural transnacional. Fue necesario delinear las caracter{\´i}sticas de los estudios culturales latinoamericanos y los Kulturwissenschaften en Alemania, para distinguir las genealog{\´i}as de estas dos diferentes perspectivas, entender sus diferencias, pero, sobre todo, encontrar los puntos en com{\´u}n entre ellas. La coincidencia central fue el car{\´a}cter transdisciplinario de estas dos tradiciones acad{\´e}micas. Los estudios culturales entonces se entienden como un espacio de articulaci{\´o}n entre disciplinas (Castro G{\´o}mez, 2002), que no tiene como objetivo la unificaci{\´o}n sino la pluralizaci{\´o}n de significados, actitudes y modos de percepci{\´o}n (Bachmann-Medick, 2016). La transdisciplina permite trazar las complejidades de los fen{\´o}menos culturales, creando puentes entre diferentes formas de conocimiento y pr{\´a}cticas de investigaci{\´o}n. El feminismo interseccional es una perspectiva central en el trabajo de investigaci{\´o}n. Una contribuci{\´o}n del feminismo a los estudios culturales que influye en esta investigaci{\´o}n es cuestionar "Hombre" y "Mujer" como esencias naturales dadas e inmutables, desde la premisa que "los signos "hombre" y "mujer" son construcciones discursivas que el lenguaje de la cultura proyecta e inscribe en el escenario de los cuerpos, disfrazando sus montajes de signos tras la falsa apariencia de que lo masculino y lo femenino son verdades naturales, ahist{\´o}ricas" (Richard, 2009, p. 77). Los estudios culturales feministas suponen que estos signos se construyen en un sistema de representaciones que articulan subjetividades en mundos culturales concretos. Su objetivo entonces es develar en las pr{\´a}cticas significantes, los elementos ideol{\´o}gicos que configuran los signos y los conflictos que se suscitan a trav{\´e}s del uso e interpretaci{\´o}n de {\´e}stos. Estos signos adquieren m{\´u}ltiples significados y lecturas de acuerdo con especificidades que se distinguen en la diferencia. La interseccionalidad, dentro del feminismo es un discurso te{\´o}rico y metodol{\´o}gico que aboga por reconocer que el signo "mujer" no es una categor{\´i}a absoluta, y por lo tanto no puede explicar por s{\´i} misma las variadas experiencias vitales de las mujeres. Las diferencias se vuelven legibles cuando se ponen en juego con otras categor{\´i}as sociales como la posici{\´o}n social, la raza, la edad y la discapacidad. Las diferencias sociales est{\´a}n fincadas en diferentes discursos que naturalizan los diferentes atributos de estas categor{\´i}as sociales cuando, para esta perspectiva, son socialmente construidos y cambiantes. El objetivo de una perspectiva interseccional es identificar c{\´o}mo interact{\´u}an diferentes categor{\´i}as sociales en instituciones, pr{\´a}cticas y subjetividades, para entender c{\´o}mo se materializan las desigualdades a trav{\´e}s del tiempo. Los conceptos te{\´o}ricos que gu{\´i}an esta tesis son cuerpo y subjetividad. Para esta tesis, el cuerpo se entiende como un sitio de articulaci{\´o}n, donde se materializan c{\´o}digos culturales y el orden social. El cuerpo puede entenderse como una frontera din{\´a}mica y mutable, donde convergen lo f{\´i}sico, lo simb{\´o}lico y lo social. Sujeto y cuerpo son mutuamente constitutivos; el cuerpo es el medio a trav{\´e}s del cual el sujeto vive experiencias en el mundo social, y son esas experiencias las que llevan al sujeto a encarnar las diferencias sociales, materializadas en g{\´e}nero, sexo, clase social y raza. A pesar de esta relaci{\´o}n indisociable, para facilitar el an{\´a}lisis, una parte se concentra en el cuerpo y otra en la subjetividad. As{\´i}, para entender la dimensi{\´o}n corporal se puso en tensi{\´o}n la representaci{\´o}n con la experiencia vivida, a trav{\´e}s del an{\´a}lisis audiovisual y la observaci{\´o}n etnogr{\´a}fica le{\´i}da en conjunto. En el caso de la subjetividad, se puso en tensi{\´o}n la vida en la narrativa de ficci{\´o}n con las narraciones de vida en entrevistas, para tambi{\´e}n encontrar los puentes entre las representaciones y la experiencia vital. Esta investigaci{\´o}n fue un estudio cualitativo y transdisciplinario. Se utilizaron diversos recursos metodol{\´o}gicos para construir el an{\´a}lisis. Se realiz{\´o} observaci{\´o}n etnogr{\´a}fica en diversos bares y clubs a ambos lados de la frontera, que son frecuentados por personas que se adscriben al mundo de la narcocultura o bien, que trabajan dentro de las redes del narcotr{\´a}fico. En las incursiones a estos sitios, se observ{\´o} el f{\´i}sico de las mujeres: su manera de vestir, su arreglo personal, sus formas corporales. Se observ{\´o} la conducta: las gestualidades y las interacciones con otros sujetos en el espacio. Adem{\´a}s, se observ{\´o} el espacio, para ver c{\´o}mo se establec{\´i}an reglas, l{\´i}mites y jerarquizaciones en la disposici{\´o}n f{\´i}sica de los lugares visitados. Se analizaron tres videos de narcocorridos a trav{\´e}s de la video hermen{\´e}utica, para determinar c{\´o}mo se representan las mujeres en estos artefactos culturales, usando los mismos criterios f{\´i}sicos y conductuales que mencion{\´e} anteriormente. El an{\´a}lisis de los videos de la mano del trabajo etnogr{\´a}fico ayud{\´o} a profundizar en los significados atribuidos a la corporalidad femenina, y tambi{\´e}n a los impactos que estos significados tienen en las vivencias y relaciones de estas mujeres. Se realizaron 5 entrevistas semi estructuradas con mujeres que se identificaban con la narcocultura. Algunas s{\´o}lo simpatizan con el estilo de vida, otras estuvieron involucradas de alguna manera en el negocio ilegal de drogas. En las entrevistas se exploraron narraciones sobre sus vidas donde se revelaban discursos sobre qu{\´e} es lo femenino, qu{\´e} significa ser mujer y c{\´o}mo se vive el ser mujer en el mundo del narcotr{\´a}fico. Adicionalmente, utilic{\´e} las narraciones de dos textos literarios de la narrativa sobre narcotr{\´a}fico del norte de M{\´e}xico. En estos dos textos, los personajes principales son mujeres. Analic{\´e} c{\´o}mo se construye al sujeto femenino en la narraci{\´o}n y qu{\´e} discursos se transparentan en el texto sobre la feminidad y ser una mujer en el mundo del narco. Aqu{\´i} tambi{\´e}n se puso en tensi{\´o}n la representaci{\´o}n y la experiencia de vida, buscando en el an{\´a}lisis de la narraci{\´o}n literaria y las experiencias narradas por las mujeres, discursos comunes que explicaran los procesos de subjetivaci{\´o}n femenina dentro de la narcocultura mexicana. La primera parte del an{\´a}lisis articul{\´o} la observaci{\´o}n etnogr{\´a}fica con el material audiovisual para entender las exigencias est{\´e}ticas que la narcocultura demanda a las mujeres y las maneras en que ellas transforman su cuerpo para complacer esta demanda. La narcocultura impone a las mujeres un ideal est{\´e}tico que se convierte en un medio de acceso a un tipo de poder. Este ideal exige un tipo particular de fisonom{\´i}a y de apariencia personal, que las mujeres intentan reproducir a trav{\´e}s de intervenciones en el cuerpo, con el maquillaje y el peinado y/o la cirug{\´i}a est{\´e}tica. Adem{\´a}s, demanda cierto estilo de moda, en ropa y accesorios, de marcas de lujo de consumo global. Entre m{\´a}s fielmente se reproduzca este ideal, las mujeres est{\´a}n en posibilidad de acceder a beneficios econ{\´o}micos y sociales que les dan m{\´a}rgenes de acci{\´o}n dentro de este entorno social. El cuerpo de las mujeres se convierte en el recurso primario para la movilidad social y la agencia dentro de este mundo. El cuerpo es el signo principal para determinar el lugar de las mujeres dentro de los sistemas de jerarquizaci{\´o}n, de inclusi{\´o}n y exclusi{\´o}n en los espacios f{\´i}sicos y sociales que fabrica el narcotr{\´a}fico. Estos mecanismos de diferencia reproducen las desigualdades sociales, de g{\´e}nero, edad, posici{\´o}n social y raza que se observan en otros {\´a}mbitos de la sociedad mexicana. La observaci{\´o}n etnogr{\´a}fica y el an{\´a}lisis audiovisual revelan que las posibilidades para performar la feminidad est{\´a} confinado a limites muy estrechos. Alicia Gaspar de Alba llama a esto The Three Maria Syndrome, que ella define como "the patriarchal social discourse of Chicano/Mexicano culture that constructs women's gender and sexuality according to three Biblical archetypes -virgins, mothers and whores-" (Gaspar de Alba, 2014, pos.3412). Estas representaciones femeninas son alegor{\´i}as a las constricciones que la cultura machista mexicana impone sobre las mujeres, someti{\´e}ndolas a un repertorio restringido de opciones de vida y al control social de su sexualidad. Las mujeres dentro de la narcocultura tienen un lugar en {\´e}l en funci{\´o}n de su belleza f{\´i}sica, el cuerpo es el referente principal para definirse como sujetos. Las mujeres son objetos de deseo, cuya belleza es una joya m{\´a}s para la corona de un narcotraficante, una posesi{\´o}n m{\´a}s para ostentar su poder{\´i}o. Al mismo tiempo, aparecen cada vez m{\´a}s las representaciones femeninas como sujetos activos, participando del negocio y de la violencia a la par de los hombres. Se observan transgresiones al ideal de feminidad que se exige a la mujer tradicional en la cultura mexicana. La docilidad, la suavidad y la sumisi{\´o}n que se espera, el recato y la compostura, no est{\´a} presente. Las mujeres adoptan cualidades consideradas masculinas, tomando para s{\´i} el ejercicio de la violencia y la agresividad sexual para demostrar que ellas tambi{\´e}n pueden navegar un mundo agresivo e hipermasculino. A pesar de esto, esta mujer guerrera y valiente est{\´a} dentro de los confines limitados que la cultura patriarcal impone al r{\´e}gimen heterosexual. Siguen al pie de la letra la prescripci{\´o}n del Three Maria Syndrome. Esto queda patente un sistema de jerarquizaci{\´o}n a trav{\´e}s de la cual se eval{\´u}a a las mujeres dentro de la narcocultura. Las mujeres son juzgadas a partir de criterios que intersectan componentes raciales, de g{\´e}nero y de clase. Aunque las maneras en las que estas marcas de diferencia se encarnan en un cuerpo femenino de manera muy diversa, se puede identificar, a trav{\´e}s de las representaciones y la observaci{\´o}n etnogr{\´a}fica, que las mujeres m{\´a}s privilegiadas, son mujeres que encarnan los signos de una posici{\´o}n econ{\´o}mica alta: tienen tez clara, son atractivas y cuidan su apariencia para presentar signos de feminidad de manera discreta, y su conducta proyecta compostura y respetabilidad, en funci{\´o}n de su restricci{\´o}n, particularmente en la expresi{\´o}n de la sexualidad. A las mujeres que encarnan estos signos de feminidad se les respeta y se consideran valiosas. Su valor se formaliza a trav{\´e}s de la respetabilidad del contrato matrimonial: este tipo de performance de g{\´e}nero lo reproducen, por lo general, mujeres esposas de narcotraficantes. En el otro extremo del espectro est{\´a}n las mujeres menos valoradas: son mujeres morenas, que utilizan una est{\´e}tica asociada con la clase trabajadora, por lo general ostentosa y recargada de decoraciones. La conducta de estas mujeres se juzga como vulgar y sin restricciones. A las mujeres que encarnan este tipo de feminidad se les discrimina y cosifica, son las m{\´a}s vulnerables a la violencia en funci{\´o}n del poco valor que tienen dentro del mundo del narcotr{\´a}fico. La buchona representa una versi{\´o}n devaluada de la feminidad, que choca con el decoro y la discreci{\´o}n que exigen las normas tradicionales de g{\´e}nero. Son mujeres que se consideran vulgares, porque sus cuerpos portan signos de una sexualidad agresiva, porque adoptan conductas que irrumpen las restricciones sociales impuestas a las mujeres, porque sus pr{\´a}cticas y consumos culturales est{\´a}n asociadas a las clases trabajadoras y rurales. En las mujeres que entrevist{\´e} hay un conflicto entre la atractiva libertad que promete la transgresi{\´o}n de ser buchona y el deseo de respetabilidad que otorga ser una mujer que cumple con lo que la sociedad exige. Uno de los dilemas al centro de performar el cuerpo buch{\´o}n es la batalla entre una feminidad aceptada socialmente, pero restrictiva y una feminidad que otorga poder, pero castiga. Por este motivo, las mujeres que entrevist{\´e} rechazaban ser nombradas como buchonas y prefer{\´i}an llamarse a s{\´i} mismas cabronas. En este contexto particular, la palabra cabrona es una resignificaci{\´o}n de un t{\´e}rmino coloquial castellano, usado para ofender. Aqu{\´i}, la mujer cabrona se convierte en un eje articulador para la constituci{\´o}n de subjetividades femeninas dentro de la narcocultura. La cabrona es un tropo femenino que entrelaza narrativas sobre ser mujer que circulan a nivel global con narrativas locales sobre la feminidad. Asumirse "cabrona", se convierte en un recurso para enfrentar un mundo violento y encontrar estrategias de acci{\´o}n en un espacio claramente dominado por los hombres. La cabrona representa independencia y fuerza, autonom{\´i}a y acci{\´o}n. La cabrona confronta los discursos tradicionales de una feminidad abnegada y d{\´o}cil, con diferentes matices, aparentemente interpelando la dominaci{\´o}n masculina. Por lo mismo, carga un fuerte estigma. La cultura de masas tambi{\´e}n produce representaciones sobre la cabrona. Se transmiten en discursos de g{\´e}nero que circulan a trav{\´e}s de im{\´a}genes en las redes sociales, en libros y workshops del mercado de autoayuda en el mundo entero, y que promueven una idea de mujer ind{\´o}cil frente a la gente de su entorno, suscrita al consumo y al individualismo de la cultura capitalista. En estas representaciones culturales contempor{\´a}neas, la mujer es fuerte e insumisa, pero conservando c{\´o}digos corporales y pr{\´a}cticas femeninas. En el contexto concreto de la narcocultura, los discursos globales sobre una mujer fuerte e independiente con poder econ{\´o}mico y a cargo de su sexualidad, se encuentran con las condiciones particulares del norte mexicano. La violencia extrema, el machismo, las desigualdades sociales pronunciadas y la crisis de legitimidad del Estado intervienen para que estos discursos globales sobre la mujer muten en la representaci{\´o}n de la buchona y la cabrona, interpretaciones locales de un discurso de g{\´e}nero global. Para las mujeres, asumirse cabrona es un recurso para enfrentar un mundo violento y encontrar estrategias de acci{\´o}n en un espacio claramente dominado por los hombres. Ayuda a enfrentar la violencia perpetrada sobre ella, abre la posibilidad a ser la victimaria. La cabrona es la reacci{\´o}n que provoca el cuerpo femenino vulnerable y vulnerado, pero tambi{\´e}n, es la posibilidad de apropiarse de la violencia para ejercerla sobre otros cuerpos. Implica independencia, libertad sexual y {\´e}xito econ{\´o}mico, evidenciadas por el consumo y el estilo de vida. Cuando niegan ser buchonas, est{\´a}n rechazando todos los estigmas que acarrea la palabra. No se reconocen en la discriminaci{\´o}n de clase, las connotaciones raciales y los prejuicios sexistas que contiene. Prefieren cabrona porque es una manera de escindirse de los discursos negativos que se vuelcan sobre ellas, es un camino de acceso a una feminidad global que los medios de comunicaci{\´o}n masiva presentan como ideal. El an{\´a}lisis explor{\´o} qu{\´e} elementos compon{\´i}an este tropo femenino a trav{\´e}s de las entrevistas a mujeres y de personajes femeninos en novelas sobre narcotr{\´a}fico, para encontrar puentes entre la ficci{\´o}n y la experiencia vital. La belleza y la capacidad de seducir tiene una utilidad ambivalente. Por un lado, todo el tiempo, dinero y cuidado que se invierte en apropiarse de un ideal est{\´e}tico, es para convertirse en una mujer que un narco pueda presumir. Para las mujeres es un motivo de orgullo saberse deseadas y puestas en aparador. Las mujeres est{\´a}n sometidas a las presiones que genera la creencia de que, para sobrevivir, hay que ser bella. En los textos literarios y en las entrevistas, se transparenta una naturalizaci{\´o}n del lugar de la mujer como objeto de ostentaci{\´o}n para el hombre y, adem{\´a}s, la validaci{\´o}n que sienten las mujeres al ser reconocidas como bellas. La ficci{\´o}n y la vida nos presentan la precaria condici{\´o}n del sujeto femenino en la narcocultura. Es una subjetividad anclada a los discursos que demandan un ideal de belleza imposible para las mujeres y que encajonan el ser mujer a los caprichos y necesidades del hombre. Sin embargo, la belleza femenina tiene otra faceta. La subjetividad femenina en la narcocultura no s{\´o}lo es resultado del sometimiento de la mujer a los discursos que regulan su apariencia y su conducta. La belleza tambi{\´e}n es un instrumento al servicio de las mujeres para acceder a dinero y poder. La belleza y el poder de seducci{\´o}n femenino se convierten en estrategias de subsistencia, y esto transforma a la mujer de un objeto sometido a un sujeto que somete. La belleza y la seducci{\´o}n podr{\´a}n dar a las mujeres ciertos m{\´a}rgenes de acci{\´o}n, pero esto tiene l{\´i}mites muy claros. Aunque estas estrategias femeninas muevan la balanza de poder hac{\´i}a el sujeto femenino, hay que recordar el contexto. Est{\´a}n insertas en un mundo violento y machista, as{\´i} que ejercer ese poder es un ejercicio de equilibrio muy delicado y arriesgado. Las mujeres que habitan la narcocultura est{\´a}n inmersas es un mundo de violencia, y no conocer y respetar las reglas y l{\´i}mites significa un riesgo de muerte. La muerte violenta es una consecuencia muy real por cometer errores en este mundo. Esto lleva a tercer componente de ser cabrona: el riesgo. Para los hombres y mujeres que se involucran en el mundo cultural del narcotr{\´a}fico, perseguir el riesgo es parte integral de vivir y es una parte importante de la constituci{\´o}n de subjetividades en la narcocultura. En las narraciones de las entrevistas y en las narraciones literarias, hay muchos momentos donde las mujeres viven situaciones de riesgo que ponen en peligro hasta sus vidas. A trav{\´e}s de las narraciones se asoma la manera en qu{\´e} ellas interpretan su papel en la situaci{\´o}n y c{\´o}mo se ven a s{\´i} mismas en funci{\´o}n de esas experiencias. El riesgo le da sentido al car{\´a}cter recio y atrevido que demanda asumir el rol de una cabrona, pero tambi{\´e}n expone la vulnerabilidad de la condici{\´o}n de las mujeres en un mundo violento. Tomar riesgos es otra manera de afirmarse como mujeres fuertes y poner distancia con las disposiciones de g{\´e}nero que les exigen ser d{\´o}ciles y pasivas. Tienen que demostrar lo que valen frente a un mundo dominado por hombres y el control de sus emociones juega un rol fundamental en lograr esto. Sin embargo, el reconocimiento del miedo y vulnerabilidad es, parad{\´o}jicamente, lo que las ayuda a sobrevivir. Detr{\´a}s de los discursos de fuerza y poder femenino, se revela la fragilidad de unas vidas sumergidas en un mundo donde la violencia y el machismo deja a las mujeres en el filo de la vida y de la muerte. Para el caso que nos compete, el vac{\´i}o institucional para garantizar seguridad a las mujeres en M{\´e}xico deja a estas mujeres absolutamente expuestas, y cobra sentido la adopci{\´o}n del discurso de la cabrona como estrategia de persistencia. Al investirse como cabronas, encuentran una manera de enfrentarse al mundo violento al que deciden pertenecer, aunque al final de cuentas, permanecen atrapadas en {\´e}l.},
  language  = {es}
}
@phdthesis{Roder2018,
  author    = {Roder, Phillip},
  title     = {Kombination von Fluoreszenzmikroskopie und Rasterkraftmikroskopie zur Aufkl{\"a}rung physiologischer Prozesse in lebenden Zellen},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419806},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvi, 113},
  year      = {2018},
  abstract  = {Innerhalb dieser Doktorarbeit wurde eine neuartige Mikromanipulationstechnik f{\"u}r die lokale Fl{\"u}ssigkeitsabgabe am komplexen Dr{\"u}sengewebe der Schabe P. americana charakterisiert und f{\"u}r die damit verbundene gezielte Manipulation von einzelnen Zellen in einem Zellkomplex (Gewebe) angewandt. Bei dieser Mikromanipulationstechnik handelt es sich um die seit 2009 bekannte nanofluidische Rasterkraftmikroskopie (FluidFM = fluidic force microscopy). Dabei werden sehr kleine mikrokan{\"a}lige Rasterkraftspitzen bzw. Mikro-/Nanopipetten mit einer {\"O}ffnung zwischen 300 nm und 2 µm verwendet, mit denen es m{\"o}glich ist, sehr kleine Volumina im Pikoliter- bis Femtoliter-Bereich (10-12 L - 10-15 L) gezielt und ortsgenau abzugeben. Das Ziel dieser Arbeit war die Analyse zellul{\"a}rer Prozesse, wie z. B. Zell-Zell-Kommunikation oder Signalweiterleitung, zwischen benachbarten Zellen unter Zuhilfenahme der Fluoreszenzmikroskopie. Mit dieser Methode k{\"o}nnen die Zellen und ihre Bestandteile mittels vorheriger Farbstoffbeladung unter einem Mikroskop mit hohem Kontrast optisch dargestellt werden. Mit Hilfe der Fluoreszenzmikroskopie sollten schlussendlich die zellul{\"a}ren Reaktionen innerhalb des Gewebes nach der lokalen Manipulation visualisiert werden. Zun{\"a}chst wurde die Anwendung des Systems an Luft und w{\"a}ssriger Umgebung beschrieben. In diesem Zusammenhang wurde eine Reinigungs- und Beladungsmethode entwickelt, mit der es m{\"o}glich war, die kostspieligen Mikro-/Nanopipetten zu reinigen und anschließend mehrmals wiederzuverwenden. Hierzu wurde eine alternative Methode getestet, mit der das Diffusionsverhalten von Farbstoffmolek{\"u}len in unterschiedlichen Medien untersucht werden kann. Des Weiteren wurden die Systemparameter optimiert, welche n{\"o}tig sind, um zwischen der Probenoberfl{\"a}che und der Pipette einen guten Pipetten{\"o}ffnungs-abschluss zu erhalten. Dieser Abschluss ist essentiell, damit die abgegebene Fl{\"u}ssigkeit ausschließlich in der Abgaberegion mit der Probe wechselwirkt und die darauffolgenden Reaktionen nur innerhalb des Gewebes erfolgen, da ansonsten die Zell-Zell-Signalweiterleitung zwischen den Zellen nicht eindeutig nachvollzogen werden kann. Diese interzellul{\"a}re Kommunikation wurde anhand zweier sekund{\"a}rer Botenstoffe (Ca2+ und NO) untersucht. Hierbei war es m{\"o}glich einzelne lokale Reaktionen zu detektieren, welche sich {\"u}ber weitere Zellen ausbreiteten. Schlussendlich wurde die Fertigung einer speziellen Injektionspipette beschrieben, welche an zwei biologischen Systemen getestet wurde.},
  language  = {de}
}
@phdthesis{Abouserie2018,
  author    = {Abouserie, Ahed},
  title     = {Ionic liquid precursors for multicomponent inorganic nanomaterials},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418950},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xx, 193},
  year      = {2018},
  abstract  = {Health effects, attributed to the environmental pollution resulted from using solvents such as benzene, are relatively unexplored among petroleum workers, personal use, and laboratory researchers. Solvents can cause various health problems, such as neurotoxicity, immunotoxicity, and carcinogenicity. As such it can be absorbed via epidermal or respiratory into the human body resulting in interacting with molecules that are responsible for biochemical and physiological processes of the brain. Owing to the ever-growing demand for finding a solution, an Ionic liquid can use as an alternative solvent. Ionic liquids are salts in a liquid state at low temperature (below 100 C), or even at room temperature. Ionic liquids impart a unique architectural platform, which has been interesting because of their unusual properties that can be tuned by simple ways such as mixing two ionic liquids. Ionic liquids not only used as reaction solvents but they became a key developing for novel applications based on their thermal stability, electric conductivity with very low vapor pressure in contrast to the conventional solvents. In this study, ionic liquids were used as a solvent and reactant at the same time for the novel nanomaterials synthesis for different applications including solar cells, gas sensors, and water splitting. The field of ionic liquids continues to grow, and become one of the most important branches of science. It appears to be at a point where research and industry can work together in a new way of thinking for green chemistry and sustainable production.},
  language  = {en}
}
@phdthesis{TchoumbaKwamen2018,
  author    = {Tchoumba Kwamen, Christelle Larodia},
  title     = {Investigating the dynamics of polarization reversal in ferroelectric thin films by time-resolved X-ray diffraction},
  doi       = {10.25932/publishup-42781},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427815},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvii, 126, xxiii},
  year      = {2018},
  abstract  = {Ferroic materials have attracted a lot of attention over the years due to their wide range of applications in sensors, actuators, and memory devices. Their technological applications originate from their unique properties such as ferroelectricity and piezoelectricity. In order to optimize these materials, it is necessary to understand the coupling between their nanoscale structure and transient response, which are related to the atomic structure of the unit cell. In this thesis, synchrotron X-ray diffraction is used to investigate the structure of ferroelectric thin film capacitors during application of a periodic electric field. Combining electrical measurements with time-resolved X-ray diffraction on a working device allows for visualization of the interplay between charge flow and structural motion. This constitutes the core of this work. The first part of this thesis discusses the electrical and structural dynamics of a ferroelectric Pt/Pb(Zr0.2,Ti0.8)O3/SrRuO3 heterostructure during charging, discharging, and polarization reversal. After polarization reversal a non-linear piezoelectric response develops on a much longer time scale than the RC time constant of the device. The reversal process is inhomogeneous and induces a transient disordered domain state. The structural dynamics under sub-coercive field conditions show that this disordered domain state can be remanent and can be erased with an appropriate voltage pulse sequence. The frequency-dependent dynamic characterization of a Pb(Zr0.52,Ti0.48)O3 layer, at the morphotropic phase boundary, shows that at high frequency, the limited domain wall velocity causes a phase lag between the applied field and both the structural and electrical responses. An external modification of the RC time constant of the measurement delays the switching current and widens the electromechanical hysteresis loop while achieving a higher compressive piezoelectric strain within the crystal. In the second part of this thesis, time-resolved reciprocal space maps of multiferroic BiFeO3 thin films were measured to identify the domain structure and investigate the development of an inhomogeneous piezoelectric response during the polarization reversal. The presence of 109° domains is evidenced by the splitting of the Bragg peak. The last part of this work investigates the effect of an optically excited ultrafast strain or heat pulse propagating through a ferroelectric BaTiO3 layer, where we observed an additional current response due to the laser pulse excitation of the metallic bottom electrode of the heterostructure.},
  language  = {en}
}
@phdthesis{Muench2018,
  author    = {M{\"u}nch, Thomas},
  title     = {Interpretation of temperature signals from ice cores},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414963},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxi, 197},
  year      = {2018},
  abstract  = {Earth's climate varies continuously across space and time, but humankind has witnessed only a small snapshot of its entire history, and instrumentally documented it for a mere 200 years. Our knowledge of past climate changes is therefore almost exclusively based on indirect proxy data, i.e. on indicators which are sensitive to changes in climatic variables and stored in environmental archives. Extracting the data from these archives allows retrieval of the information from earlier times. Obtaining accurate proxy information is a key means to test model predictions of the past climate, and only after such validation can the models be used to reliably forecast future changes in our warming world. The polar ice sheets of Greenland and Antarctica are one major climate archive, which record information about local air temperatures by means of the isotopic composition of the water molecules embedded in the ice. However, this temperature proxy is, as any indirect climate data, not a perfect recorder of past climatic variations. Apart from local air temperatures, a multitude of other processes affect the mean and variability of the isotopic data, which hinders their direct interpretation in terms of climate variations. This applies especially to regions with little annual accumulation of snow, such as the Antarctic Plateau. While these areas in principle allow for the extraction of isotope records reaching far back in time, a strong corruption of the temperature signal originally encoded in the isotopic data of the snow is expected. This dissertation uses observational isotope data from Antarctica, focussing especially on the East Antarctic low-accumulation area around the Kohnen Station ice-core drilling site, together with statistical and physical methods, to improve our understanding of the spatial and temporal isotope variability across different scales, and thus to enhance the applicability of the proxy for estimating past temperature variability. The presented results lead to a quantitative explanation of the local-scale (1-500 m) spatial variability in the form of a statistical noise model, and reveal the main source of the temporal variability to be the mixture of a climatic seasonal cycle in temperature and the effect of diffusional smoothing acting on temporally uncorrelated noise. These findings put significant limits on the representativity of single isotope records in terms of local air temperature, and impact the interpretation of apparent cyclicalities in the records. Furthermore, to extend the analyses to larger scales, the timescale-dependency of observed Holocene isotope variability is studied. This offers a deeper understanding of the nature of the variations, and is crucial for unravelling the embedded true temperature variability over a wide range of timescales.},
  language  = {en}
}
@phdthesis{Lopes2018,
  author    = {Lopes, Pedro},
  title     = {Interactive Systems Based on Electrical Muscle Stimulation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421165},
  school      = {Universit{\"a}t Potsdam},
  pages     = {171},
  year      = {2018},
  abstract  = {How can interactive devices connect with users in the most immediate and intimate way? This question has driven interactive computing for decades. Throughout the last decades, we witnessed how mobile devices moved computing into users' pockets, and recently, wearables put computing in constant physical contact with the user's skin. In both cases moving the devices closer to users allowed devices to sense more of the user, and thus act more personal. The main question that drives our research is: what is the next logical step? Some researchers argue that the next generation of interactive devices will move past the user's skin and be directly implanted inside the user's body. This has already happened in that we have pacemakers, insulin pumps, etc. However, we argue that what we see is not devices moving towards the inside of the user's body, but rather towards the body's biological "interface" they need to address in order to perform their function. To implement our vision, we created a set of devices that intentionally borrow parts of the user's body for input and output, rather than adding more technology to the body. In this dissertation we present one specific flavor of such devices, i.e., devices that borrow the user's muscles. We engineered I/O devices that interact with the user by reading and controlling muscle activity. To achieve the latter, our devices are based on medical-grade signal generators and electrodes attached to the user's skin that send electrical impulses to the user's muscles; these impulses then cause the user's muscles to contract. While electrical muscle stimulation (EMS) devices have been used to regenerate lost motor functions in rehabilitation medicine since the 1960s, in this dissertation, we propose a new perspective: EMS as a means for creating interactive systems. We start by presenting seven prototypes of interactive devices that we have created to illustrate several benefits of EMS. These devices form two main categories: (1) Devices that allow users eyes-free access to information by means of their proprioceptive sense, such as the value of a variable in a computer system, a tool, or a plot; (2) Devices that increase immersion in virtual reality by simulating large forces, such as wind, physical impact, or walls and heavy objects. Then, we analyze the potential of EMS to build interactive systems that miniaturize well and discuss how they leverage our proprioceptive sense as an I/O modality. We proceed by laying out the benefits and disadvantages of both EMS and mechanical haptic devices, such as exoskeletons. We conclude by sketching an outline for future research on EMS by listing open technical, ethical and philosophical questions that we left unanswered.},
  language  = {en}
}
@phdthesis{Hesse2018,
  author    = {Hesse, Cornelia},
  title     = {Integrated water quality modelling in meso- to large-scale catchments of the Elbe river basin under climate and land use change},
  doi       = {10.25932/publishup-42295},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-422957},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ix, 217},
  year      = {2018},
  abstract  = {In einer sich {\"a}ndernden Umwelt sind Fließgew{\"a}sser{\"o}kosysteme vielf{\"a}ltigen direkten und indirekten anthropogenen Belastungen ausgesetzt, die die Gew{\"a}sser sowohl in ihrer Menge als auch in ihrer G{\"u}te beeintr{\"a}chtigen k{\"o}nnen. Ein {\"u}berm{\"a}ßiger Eintrag von N{\"a}hrstoffen verursacht etwa Massenentwicklungen von Algen und Sauerstoffdefizite in den Gew{\"a}ssern, was zum Verfehlen der Ziele der Wasserrahmenrichtlinie (WRRL) f{\"u}hren kann. In vielen europ{\"a}ischen Einzugsgebieten und auch dem der Elbe sind solche Probleme zu beobachten. W{\"a}hrend der letzten Jahrzehnte entstanden diverse computergest{\"u}tzte Modelle, die zum Schutz und Management von Wasserressourcen genutzt werden k{\"o}nnen. Sie helfen beim Verstehen der N{\"a}hrstoffprozesse und Belastungspfade in Einzugsgebieten, bei der Absch{\"a}tzung m{\"o}glicher Folgen von Klima- und Landnutzungs{\"a}nderungen f{\"u}r die Wasserk{\"o}rper, sowie bei der Entwicklung eventueller Kompensationsmaßnahmen. Aufgrund der Vielzahl an sich gegenseitig beeinflussenden Prozessen ist die Modellierung der Wasserqualit{\"a}t komplexer und aufw{\"a}ndiger als eine reine hydrologische Modellierung. {\"O}kohydrologische Modelle zur Simulation der Gew{\"a}sserg{\"u}te, einschließlich des Modells SWIM (Soil and Water Integrated Model), bed{\"u}rfen auch h{\"a}ufig noch einer Weiterentwicklung und Verbesserung der Prozessbeschreibungen. Aus diesen {\"U}berlegungen entstand die vorliegende Dissertation, die sich zwei Hauptanliegen widmet: 1) einer Weiterentwicklung des N{\"a}hrstoffmoduls des {\"o}kohydrologischen Modells SWIM f{\"u}r Stickstoff- und Phosphorprozesse, und 2) der Anwendung des Modells SWIM im Elbegebiet zur Unterst{\"u}tzung eines anpassungsf{\"a}higen Wassermanagements im Hinblick auf m{\"o}gliche zuk{\"u}nftige {\"A}nderungen der Umweltbedingungen. Die kumulative Dissertation basiert auf f{\"u}nf wissenschaftlichen Artikeln, die in internationalen Zeitschriften ver{\"o}ffentlicht wurden. Im Zuge der Arbeit wurden verschiedene Modellanpassungen in SWIM vorgenommen, wie etwa ein einfacher Ansatz zur Verbesserung der Simulation der Wasser- und N{\"a}hrstoffverh{\"a}ltnisse in Feuchtgebieten, ein um Ammonium erweiterter Stickstoffkreislauf im Boden, sowie ein Flussprozessmodul, das Umwandlungsprozesse, Sauerstoffverh{\"a}ltnisse und Algenwachstum im Fließgew{\"a}sser simuliert, haupts{\"a}chlich angetrieben von Temperatur und Licht. Auch wenn dieser neue Modellansatz ein sehr komplexes Modell mit einer Vielzahl an neuen Kalibrierungsparametern und steigender Unsicherheit erzeugte, konnten gute Ergebnisse in den Teileinzugsgebieten und dem gesamten Gebiet der Elbe erzielt werden, so dass das Modell zur Absch{\"a}tzung m{\"o}glicher Folgen von Klimavariabilit{\"a}ten und ver{\"a}nderten anthropogenen Einfl{\"u}ssen f{\"u}r die Gew{\"a}sserg{\"u}te genutzt werden konnte. Das neue Fließgew{\"a}ssermodul ist ein wichtiger Beitrag zur Verbesserung der N{\"a}hrstoffmodellierung in SWIM, vor allem f{\"u}r Stoffe, die haupts{\"a}chlich aus Punktquellen in die Gew{\"a}sser gelangen (wie z.B. Phosphat). Der neue Modellansatz verbessert zudem die Anwendbarkeit von SWIM f{\"u}r Fragestellungen im Zusammenhang mit der WRRL, bei der biologische Qualit{\"a}tskomponenten (wie etwa Phytoplankton) eine zentrale Rolle spielen. Die dargestellten Ergebnisse der Wirkungsstudien k{\"o}nnen bei Entscheidungstr{\"a}gern und anderen Akteuren das Verst{\"a}ndnis f{\"u}r zuk{\"u}nftige Herausforderungen im Gew{\"a}ssermanagement erh{\"o}hen und dazu beitragen, ein angepasstes Management f{\"u}r das Elbeeinzugsgebiet zu entwickeln.},
  language  = {en}
}
@phdthesis{Ramage2018,
  author    = {Ramage, Justine Lucille},
  title     = {Impact of Hillslope Thermokarst on the Nearshore Carbon Budget Along the Yukon Coast, Canada},
  doi       = {10.25932/publishup-42186},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421867},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvii, 103},
  year      = {2018},
  abstract  = {In ice-rich permafrost regions, changes in the permafrost thermal regime cause surface disturbances. These changes are amplified by the increase in air temperatures recorded in the Arctic in the past decades. Thermokarst is a process that leads to surface subsidence and formation of characteristic landforms following thawing of ice-rich permafrost or melting of massive ice. Thermokarst is widespread on hillslopes and the number of associated landforms is increasing in the Arctic. Through this process large amounts of material are eroded and transported to the sea or accumulate along hillslopes. While hillslope thermokarst modifies terrestrial and aquatic ecosystems, there is limited understanding of its environmental impact at a regional scale. In this thesis we quantify the environmental impacts of hillslope thermokarst on the valley and nearshore ecosystems along the Yukon Coast, Canada. Using supervised machine learning, we identified geomorphic factors that favour the development of coastal retrogressive thaw slump (RTS), one of the most dynamic hillslope thermokarst landform. Coastal geomorphology and ground ice type and content play a major role in RTS occurrence. Using aerial photographs and satellite imagery, we traced the evolution of RTSs between 1952 and 2011. During this time, the number and areal coverage of RTSs increased by 73\%. RTSs eroded and partly released to the nearshore zone organic carbon contained in millions of cubic meters of material. Our results show that 56\% of the RTSs identified along the coast in 2011 have eroded 16.6 × 10^6 m3 of material; a large part (45\%) was transported alongshore due to coastal processes. Moreover, we show that RTSs are a major contributor to the carbon budget in the nearshore ecosystem: 17\% of the coastal RTSs identified in 2011 contributed annually up to 0.6\% of the organic carbon released by coastal retreat along the Yukon Coast. To assess the impact of hillslope thermokarst on the terrestrial ecosystem, we measured the spatial distribution of soil organic carbon (SOC) and total nitrogen (TN) along hillslopes in three Arctic valleys. We highlight the high spatial variability in the distribution of SOC and TN in the valleys. This distribution is caused by complex soil processes occurring along the hillslopes. Hillslope thermokarst impacts the degradation of organic matter and affects the storage of SOC and TN.},
  language  = {de}
}
@phdthesis{Danckert2018,
  author    = {Danckert, Lena},
  title     = {Immunscreening Virulenz-adaptierter Expressionsbibliotheken aus einem in vitro Infektionsmodell mit Salmonella Enteritidis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421108},
  school      = {Universit{\"a}t Potsdam},
  pages     = {144},
  year      = {2018},
  abstract  = {Die Folgen einer lebensmittelbedingten Erkrankung sind zum Teil gravierend, insbesondere f{\"u}r Kinder und immunsupprimierte Menschen. Hierbei geh{\"o}ren Salmonella und Campylobacter zu den h{\"a}ufigsten Erregern, die verantwortlich f{\"u}r gastrointestinale Erkrankungen in Deutschland sind. Trotz umfassender Maßnahmen der EU zur Pr{\"a}vention und Bek{\"a}mpfung von Salmonellen in Gefl{\"u}gelbest{\"a}nden und der Lebensmittel-Industrie, wird von einem stagnierenden Trend von Infektionszahlen berichtet. Zoonose-Erreger wie Salmonellen k{\"o}nnen {\"u}ber Nutztiere in die Nahrungskette des Menschen gelangen, wodurch sich Infektionsherde schnell ausbreiten k{\"o}nnen. Dabei sind bestehende Pr{\"a}ventionsstrategien f{\"u}r Gefl{\"u}gel vorhanden, die aber nicht auf den Menschen {\"u}bertragbar sind. Folglich sind Diagnostik und Pr{\"a}vention in der Lebensmittelindustrie essentiell. Deshalb besteht ein hoher Bedarf f{\"u}r spezifische, sensitive und zuverl{\"a}ssige Nachweismethoden, die eine Point-of-care Diagnostik gew{\"a}hrleisten. Durch ein wachsendes Verst{\"a}ndnis der wirtsspezifischen Faktoren von S. enterica Serovaren kann die Entwicklung sowohl neuartiger diagnostischer Methoden, als auch neuartiger Therapien und Impfstoffe maßgeblich vorangetrieben werden. Infolgedessen wurde in dieser Arbeit ein infektions{\"a}hnliches in vitro Modell f{\"u}r S. Enteritidis etabliert und darauf basierend eine umfassende Untersuchung zur Identifizierung neuer Zielstrukturen f{\"u}r den Erreger durchgef{\"u}hrt. W{\"a}hrend einer Salmonellen-Infektion ist die erste zellul{\"a}re Barriere im Wirt die Epithelschicht. Dementsprechend wurde eine humane Zelllinie (CaCo 2, Darmepithel) f{\"u}r die Pathogen-Wirt-Studie ausgew{\"a}hlt. Das Salmonellen-Transkriptom und morphologische Eigenschaften der Epithelzellen wurden in verschiedenen Phasen der Salmonellen-Infektion untersucht und mit bereits gut beschriebenen Virulenzfaktoren und Beobachtungen in Bezug gesetzt. Durch dieses Infektionsmodell konnte ein spezifischer Ph{\"a}notyp f{\"u}r die intrazellul{\"a}ren Salmonellen in den Epithelzellen nachgewiesen werden. Zudem wurde aufgezeigt, dass bereits die Kultivierung in Fl{\"u}ssigmedium einen invasionsaktiven Zustand der Salmonellen erzeugt. Allerdings wurde durch die Kokultivierung mit Epithelzellen eine zus{\"a}tzliche Expression relevanter Gene induziert, um eine effiziente Adh{\"a}sion und Transmembran-Transport zu gew{\"a}hrleisten. Letzterer ist charakteristisch f{\"u}r die intrazellul{\"a}re Limitierung von N{\"a}hrstoffen und pr{\"a}gt den infektionsrelevanten Status. Unter Ber{\"u}cksichtigung dieser Faktoren ergab sich ein Ph{\"a}notyp, der eindeutig Mechanismen zur Wirtsadaptation und m{\"o}glicherweise auch Pathogenese aufzeigt. Die intrazellul{\"a}ren Bakterien m{\"u}ssen vom Wirt separiert werden, was ein wesentlicher Schritt f{\"u}r Pathogen-bestimmende Analysen ist. Hierbei wurde mithilfe einer Detergenz-basierten Lyse der eukaryotischen Zellmembran und differentieller Zentrifugation, der eukaryotische Eintrag minimal gehalten. Unter Verwendung der Virulenz-adaptierten Salmonellen wurden Untersuchungen in Hinblick auf die Identifizierung neuer Zielstrukturen f{\"u}r S. Enteritidis durchgef{\"u}hrt. Mithilfe eines immunologischen Screenings wurden neue potentielle Antigene entdeckt. Zu diesem Zweck wurden bakterielle cDNA-basierte Expressionsbibliotheken hergestellt, die durch eine vereinfachte Microarray-Anwendung ein Hochdurchsatzscreening von Proteinen als potentielle Binder erm{\"o}glichen. Folglich konnten neue unbeschriebene Proteine identifiziert werden, die sich durch eine Salmonella-Spezifit{\"a}t oder Membranst{\"a}ndigkeit auszeichnen. Ebenso wurde ein Vergleich der im Screening identifizierten Proteine mit der Regulation der kodierenden Gene im infektions{\"a}hnlichen Modell durchgef{\"u}hrt. Dabei wurde deutlich, dass die H{\"a}ufigkeit von Transkripten einen Einfluss auf die Verf{\"u}gbarkeit in der cDNA-Bibliothek und folglich auch auf die Expressionsbibliothek nimmt. Angesichts eines Ungleichgewichts zwischen der Gesamtzahl protein-kodierender Gene in S. Enteritidis zu m{\"o}glichen Klonen, die w{\"a}hrend des Microarray-Screenings untersucht werden k{\"o}nnen, besteht der Bedarf einer Anreicherung von Proteinen in der Expressionsbibliothek. Das infektions{\"a}hnliche Modell zeigte, dass nicht nur Virulenz-assoziierte, sondern auch Stress- und Metabolismus-relevante Gene hochreguliert werden. Durch die Konstruktion dieser spezifischen cDNA-Bibliotheken ist die Erkennung von charakteristischen molekularen Markern gegeben. Weiterhin wurden anhand der Transkriptomanalyse spezifisch hochregulierte Gene identifiziert, die relevant f{\"u}r das intrazellul{\"a}re {\"U}berleben von S. Enteritidis in humanen Epithelzellen sind. Hiervon wurden drei Gene n{\"a}her untersucht, indem ihr Einfluss im infektions{\"a}hnlichen Modell mittels entsprechender Gen-Knockout-St{\"a}mme analysiert wurde. Dabei wurde f{\"u}r eine dieser Mutanten ein reduziertes Wachstum in der sp{\"a}ten intrazellul{\"a}ren Phase nachgewiesen. Weiterf{\"u}hrende in vitro Analysen sind f{\"u}r die Charakterisierung des Knockout-Stamms notwendig, um den Einsatz als potenzielles Therapeutikum zu verifizieren. Zusammenfassend wurde ein in vitro Infektionsmodell f{\"u}r S. Enteritidis etabliert, wodurch neue Zielstrukturen des Erregers identifiziert wurden. Diese sind f{\"u}r diagnostische oder therapeutische Anwendungen interessant. Das Modell l{\"a}sst sich ebenso f{\"u}r andere intrazellul{\"a}re Pathogene {\"u}bertragen und gew{\"a}hrleistet eine zuverl{\"a}ssige Identifizierung von potentiellen Antigenen.},
  language  = {de}
}
@phdthesis{Rothkegel2018,
  author    = {Rothkegel, Lars Oliver Martin},
  title     = {Human scanpaths in natural scene viewing and natural scene search},
  doi       = {10.25932/publishup-42000},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420005},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xv, 131},
  year      = {2018},
  abstract  = {Understanding how humans move their eyes is an important part for understanding the functioning of the visual system. Analyzing eye movements from observations of natural scenes on a computer screen is a step to understand human visual behavior in the real world. When analyzing eye-movement data from scene-viewing experiments, the impor- tant questions are where (fixation locations), how long (fixation durations) and when (ordering of fixations) participants fixate on an image. By answering these questions, computational models can be developed which predict human scanpaths. Models serve as a tool to understand the underlying cognitive processes while observing an image, especially the allocation of visual attention. The goal of this thesis is to provide new contributions to characterize and model human scanpaths on natural scenes. The results from this thesis will help to understand and describe certain systematic eye-movement tendencies, which are mostly independent of the image. One eye-movement tendency I focus on throughout this thesis is the tendency to fixate more in the center of an image than on the outer parts, called the central fixation bias. Another tendency, which I will investigate thoroughly, is the characteristic distribution of angles between successive eye movements. The results serve to evaluate and improve a previously published model of scanpath generation from our laboratory, the SceneWalk model. Overall, six experiments were conducted for this thesis which led to the following five core results: i) A spatial inhibition of return can be found in scene-viewing data. This means that locations which have already been fixated are afterwards avoided for a certain time interval (Chapter 2). ii) The initial fixation position when observing an image has a long-lasting influence of up to five seconds on further scanpath progression (Chapter 2 \& 3). iii) The often described central fixation bias on images depends strongly on the duration of the initial fixation. Long-lasting initial fixations lead to a weaker central fixation bias than short fixations (Chapter 2 \& 3). iv) Human observers adjust their basic eye-movement parameters, like fixation dura- tions and saccade amplitudes, to the visual properties of a target they look for in visual search (Chapter 4). v) The angle between two adjacent saccades is an indicator for the selectivity of the upcoming saccade target (Chapter 4). All results emphasize the importance of systematic behavioral eye-movement tenden- cies and dynamic aspects of human scanpaths in scene viewing.},
  language  = {en}
}
@phdthesis{Cheng2018,
  author    = {Cheng, Lung-Pan},
  title     = {Human actuation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418371},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xiv, 85},
  year      = {2018},
  abstract  = {Ever since the conception of the virtual reality headset in 1968, many researchers have argued that the next step in virtual reality is to allow users to not only see and hear, but also feel virtual worlds. One approach is to use mechanical equipment to provide haptic feedback, e.g., robotic arms, exoskeletons and motion platforms. However, the size and the weight of such mechanical equipment tends to be proportional to its target's size and weight, i.e., providing human-scale haptic feedback requires human-scale equipment, often restricting them to arcades and lab environments. The key idea behind this dissertation is to bypass mechanical equipment by instead leveraging human muscle power. We thus create software systems that orchestrate humans in doing such mechanical labor—this is what we call human actuation. A potential benefit of such systems is that humans are more generic, flexible, and versatile than machines. This brings a wide range of haptic feedback to modern virtual reality systems. We start with a proof-of-concept system—Haptic Turk, focusing on delivering motion experiences just like a motion platform. All Haptic Turk setups consist of a user who is supported by one or more human actuators. The user enjoys an interactive motion simulation such as a hang glider experience, but the motion is generated by those human actuators who manually lift, tilt, and push the user's limbs or torso. To get the timing and force right, timed motion instructions in a format familiar from rhythm games are generated by the system. Next, we extend the concept of human actuation from 3-DoF to 6-DoF virtual reality where users have the freedom to walk around. TurkDeck tackles this problem by orchestrating a group of human actuators to reconfigure a set of passive props on the fly while the user is progressing in the virtual environment. TurkDeck schedules human actuators by their distances from the user, and instructs them to reconfigure the props to the right place on the right time using laser projection and voice output. Our studies in Haptic Turk and TurkDeck showed that human actuators enjoyed the experience but not as much as users. To eliminate the need of dedicated human actuators, Mutual Turk makes everyone a user by exchanging mechanical actuation between two or more users. Mutual Turk's main functionality is that it orchestrates the users so as to actuate props at just the right moment and with just the right force to produce the correct feedback in each other's experience. Finally, we further eliminate the need of another user, making human actuation applicable to single-user experiences. iTurk makes the user constantly reconfigure and animate otherwise passive props. This allows iTurk to provide virtual worlds with constantly varying or even animated haptic effects, even though the only animate entity present in the system is the user. Our demo experience features one example each of iTurk's two main types of props, i.e., reconfigurable props (the foldable board from TurkDeck) and animated props (the pendulum). We conclude this dissertation by summarizing the findings of our explorations and pointing out future directions. We discuss the development of human actuation compare to traditional machine actuation, the possibility of combining human and machine actuators and interaction models that involve more human actuators.},
  language  = {en}
}
@phdthesis{Angermann2018,
  author    = {Angermann, Lisa},
  title     = {Hillslope-stream connectivity across scales},
  doi       = {10.25932/publishup-42454},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-424542},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xix, 193},
  year      = {2018},
  abstract  = {The concept of hydrologic connectivity summarizes all flow processes that link separate regions of a landscape. As such, it is a central theme in the field of catchment hydrology, with influence on neighboring disciplines such as ecology and geomorphology. It is widely acknowledged to be an important key in understanding the response behavior of a catchment and has at the same time inspired research on internal processes over a broad range of scales. From this process-hydrological point of view, hydrological connectivity is the conceptual framework to link local observations across space and scales. This is the context in which the four studies this thesis comprises of were conducted. The focus was on structures and their spatial organization as important control on preferential subsurface flow. Each experiment covered a part of the conceptualized flow path from hillslopes to the stream: soil profile, hillslope, riparian zone, and stream. For each study site, the most characteristic structures of the investigated domain and scale, such as slope deposits and peat layers were identified based on preliminary or previous investigations or literature reviews. Additionally, further structural data was collected and topographical analyses were carried out. Flow processes were observed either based on response observations (soil moisture changes or discharge patterns) or direct measurement (advective heat transport). Based on these data, the flow-relevance of the characteristic structures was evaluated, especially with regard to hillslope to stream connectivity. Results of the four studies revealed a clear relationship between characteristic spatial structures and the hydrological behavior of the catchment. Especially the spatial distribution of structures throughout the study domain and their interconnectedness were crucial for the establishment of preferential flow paths and their relevance for large-scale processes. Plot and hillslope-scale irrigation experiments showed that the macropores of a heterogeneous, skeletal soil enabled preferential flow paths at the scale of centimeters through the otherwise unsaturated soil. These flow paths connected throughout the soil column and across the hillslope and facilitated substantial amounts of vertical and lateral flow through periglacial slope deposits. In the riparian zone of the same headwater catchment, the connectivity between hillslopes and stream was controlled by topography and the dualism between characteristic subsurface structures and the geomorphological heterogeneity of the stream channel. At the small scale (1 m to 10 m) highest gains always occurred at steps along the longitudinal streambed profile, which also controlled discharge patterns at the large scale (100 m) during base flow conditions (number of steps per section). During medium and high flow conditions, however, the impact of topography and parafluvial flow through riparian zone structures prevailed and dominated the large-scale response patterns. In the streambed of a lowland river, low permeability peat layers affected the connectivity between surface water and groundwater, but also between surface water and the hyporheic zone. The crucial factor was not the permeability of the streambed itself, but rather the spatial arrangement of flow-impeding peat layers, causing increased vertical flow through narrow "windows" in contrast to predominantly lateral flow in extended areas of high hydraulic conductivity sediments. These results show that the spatial organization of structures was an important control for hydrological processes at all scales and study areas. In a final step, the observations from different scales and catchment elements were put in relation and compared. The main focus was on the theoretical analysis of the scale hierarchies of structures and processes and the direction of causal dependencies in this context. Based on the resulting hierarchical structure, a conceptual framework was developed which is capable of representing the system's complexity while allowing for adequate simplifications. The resulting concept of the parabolic scale series is based on the insight that flow processes in the terrestrial part of the catchment (soil and hillslopes) converge. This means that small-scale processes assemble and form large-scale processes and responses. Processes in the riparian zone and the streambed, however, are not well represented by the idea of convergence. Here, the large-scale catchment signal arrives and is modified by structures in the riparian zone, stream morphology, and the small-scale interactions between surface water and groundwater. Flow paths diverge and processes can better be represented by proceeding from large scales to smaller ones. The catchment-scale representation of processes and structures is thus the conceptual link between terrestrial hillslope processes and processes in the riparian corridor.},
  language  = {en}
}
@phdthesis{Sapegin2018,
  author    = {Sapegin, Andrey},
  title     = {High-Speed Security Log Analytics Using Hybrid Outlier Detection},
  doi       = {10.25932/publishup-42611},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-426118},
  school      = {Universit{\"a}t Potsdam},
  pages     = {162},
  year      = {2018},
  abstract  = {The rapid development and integration of Information Technologies over the last decades influenced all areas of our life, including the business world. Yet not only the modern enterprises become digitalised, but also security and criminal threats move into the digital sphere. To withstand these threats, modern companies must be aware of all activities within their computer networks. The keystone for such continuous security monitoring is a Security Information and Event Management (SIEM) system that collects and processes all security-related log messages from the entire enterprise network. However, digital transformations and technologies, such as network virtualisation and widespread usage of mobile communications, lead to a constantly increasing number of monitored devices and systems. As a result, the amount of data that has to be processed by a SIEM system is increasing rapidly. Besides that, in-depth security analysis of the captured data requires the application of rather sophisticated outlier detection algorithms that have a high computational complexity. Existing outlier detection methods often suffer from performance issues and are not directly applicable for high-speed and high-volume analysis of heterogeneous security-related events, which becomes a major challenge for modern SIEM systems nowadays. This thesis provides a number of solutions for the mentioned challenges. First, it proposes a new SIEM system architecture for high-speed processing of security events, implementing parallel, in-memory and in-database processing principles. The proposed architecture also utilises the most efficient log format for high-speed data normalisation. Next, the thesis offers several novel high-speed outlier detection methods, including generic Hybrid Outlier Detection that can efficiently be used for Big Data analysis. Finally, the special User Behaviour Outlier Detection is proposed for better threat detection and analysis of particular user behaviour cases. The proposed architecture and methods were evaluated in terms of both performance and accuracy, as well as compared with classical architecture and existing algorithms. These evaluations were performed on multiple data sets, including simulated data, well-known public intrusion detection data set, and real data from the large multinational enterprise. The evaluation results have proved the high performance and efficacy of the developed methods. All concepts proposed in this thesis were integrated into the prototype of the SIEM system, capable of high-speed analysis of Big Security Data, which makes this integrated SIEM platform highly relevant for modern enterprise security applications.},
  language  = {en}
}
@phdthesis{Haendel2018,
  author    = {H{\"a}ndel, Annabel},
  title     = {Ground-motion model selection and adjustment for seismic hazard analysis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418123},
  school      = {Universit{\"a}t Potsdam},
  pages     = {122},
  year      = {2018},
  abstract  = {Erdbeben k{\"o}nnen starke Bodenbewegungen erzeugen und es ist wichtig, diese in einer seismischen Gef{\"a}hrdungsanalyse korrekt vorherzusagen. {\"U}blicherweise werden dazu empirisch ermittelte Bodenbewegungsmodelle (GMPE) in einem logischen Baum zusammengef{\"u}gt. Wenn jedoch die Bodenbewegung in einem Gebiet mit geringer Seismizit{\"a}t bestimmen werden soll, dann fehlen in der Regel die Daten, um regionsspezifische GMPEs zu entwickeln. In diesen F{\"a}llen ist es notwendig, auf Modelle aus anderen Gebieten mit guter Datengrundlage zur{\"u}ckzugreifen und diese an die Zielregion anzupassen. Zur korrekten Anpassung werden seismologische Informationen aus der Zielregion wie beispielsweise die standortspezifische D{\"a}mpfung kappa0 ben{\"o}tigt. Diese Parameter lassen sich jedoch ebenfalls nur unzuverl{\"a}ssig bestimmen, wenn die Datengrundlage schlecht ist. In meiner Dissertation besch{\"a}ftige ich mich daher mit der Auswahl von GMPEs f{\"u}r den logischen Baum beziehungsweise deren Anpassung an Regionen mit geringer Seismizit{\"a}t. Ich folge dabei zwei verschiedenen Strategien. Im ersten Ansatz geht es um das Aufstellen eines logischen Baumes, falls kein regionsspezifisches Modell vorhanden ist. Ich stelle eine Methode vor, in der mehrere regionsfremde Modelle zu einem Mixmodell zusammengef{\"u}gt werden. Die Modelle werden dabei je nach ihrer Eignung gewichtet und die Gewichte mittels der wenigen verf{\"u}gbaren Daten aus der Zielregion ermittelt. Ein solches Mixmodell kann als sogenanntes 'Backbone'-Modell verwendet werden, welches in der Lage ist, mittlere Bodenbewegungen in der Zielregion korrekt vorherzusagen. Ich teste diesen Ansatz f{\"u}r Nordchile und acht GMPEs, die f{\"u}r verschiedene Subduktionszonen auf der Welt entwickelt wurden. Die Resultate zeigen, dass das Mixmodell bessere Ergebnisse liefert als die einzelnen GMPEs, die zu seiner Erzeugung genutzt wurden. Es ist außerdem ebenso gut in der Vorhersage von Bodenbewegungen wie ein Regressionsmodell, welches extra f{\"u}r Nordchile entwickelt wurde. Im zweiten Ansatz besch{\"a}ftige ich mich mit der Bestimmung der standortspezifischen D{\"a}mpfung kappa0. kappa0 ist einer der wichtigsten Parameter zur Anpassung eines GMPEs an eine andere Region. Mein Ziel ist es, kappa0 aus seismischer Bodenunruhe anstelle von Erdbeben zu ermitteln, da diese kontinuierlich aufgezeichnet wird. Mithilfe von Interferometrie kann die Geschwindigkeit und D{\"a}mpfung von seismischen Wellen im Untergrund bestimmt werden. Dazu werden lange Aufzeichnungsreihen seismischer Bodenunruhe entweder kreuzkorreliert oder entfaltet (Dekonvolution). Die Bestimmung der D{\"a}mpfung aus Bodenunruhe bei Frequenzen {\"u}ber 1 Hz und in geringen Tiefen ist jedoch nicht trivial. Ich zeige in meiner Dissertation die Ergebnisse von zwei Studien. In der ersten Studie wird die D{\"a}mpfung von Love-Wellen zwischen 1-4 Hz f{\"u}r ein kleines Testarray in Griechenland ermittelt. In der zweiten Studie verwende ich die Daten einer Bohrloch und einer Oberfl{\"a}chenstation aus dem Vogtland, um die D{\"a}mpfung von S-Wellen zwischen 5-15 Hz zu bestimmen. Diese beiden Studien stellen jedoch nur den Ausgangspunkt f{\"u}r zuk{\"u}nftige Untersuchungen dar, in denen kappa0 direkt aus der seismischer Bodenunruhe hergeleitet werden soll.},
  language  = {en}
}
@phdthesis{Strunk2018,
  author    = {Strunk, David},
  title     = {Gewinnung phenolischer Komponenten aus dem Birkenstamm als Rohstoffquelle f{\"u}r die Synthese eines neuen substituierten Phenylmethacrylats und dessen Polymerisation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-409228},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VIII, 157},
  year      = {2018},
  abstract  = {In der vorliegenden Arbeit werden Wege zur Gewinnung verschiedener phenolischer Substanzen wie Lignin, Diarylheptanoide und 4-(3-Oxobutyl)phenol (Himbeerketon) aus dem Stamm der H{\"a}ngebirke (Betula pendula) aufgezeigt. Durch Methacrylierung des 4-(3-Oxobutyl)phenols wurde ein Monomer erzeugt, welches mittels freier radikalischer Masse- und L{\"o}sungspolymerisation, sowie enzymatischer Polymerisation polymerisiert werden kann. Eine erste Isolierung von Bestandteilen wurde durch Extraktion von Innenholz bzw. Rinde mit Methanol erzielt. Die in Methanol unl{\"o}slichen Bestandteile des Innenholzes und der Rinde wurden anschließend mit ausgew{\"a}hlten ionischen Fl{\"u}ssigkeiten extrahiert. Es wurde ein Verfahren zum selektiven Trennen der mit diesen ionischen Fl{\"u}ssigkeiten extrahierten Bestandteile in Cellulose, Hemicellulose, Lignin und mit Ethylacetat extrahierbare Bestandteile entwickelt. Hierdurch war es m{\"o}glich, sowohl die verwendeten ionischen Fl{\"u}ssigkeiten als auch das Innenholz und die Rinde hinsichtlich ihres Extraktionsverhaltens miteinander zu vergleichen. Ferner wurden verschiedene Strategien aufgezeigt, um insgesamt drei Spezies an Diarylheptanoiden aus dem methanolischen Extrakt der Rinde zu isolieren. Eines der gefundenen Diarylheptanoide (5 Hydroxy-1,7-bis(4-hydroxyphenyl)-3-heptanon) wurde via Retroaldolreaktion in 4 (3 Oxobutyl)phenol (Himbeerketon) und 3 (4 Hydroxyphenyl)propanal gespalten. Es wurde die Verwendung des 4-(3-Oxobutyl)phenol als Monomerbestandteil untersucht. Hierf{\"u}r wurde 4-(3-Oxobutyl)phenylmethacrylat synthetisiert und Wege zur Reinigung mittels S{\"a}ulenchromatographie und Umkristallisation aufgezeigt. Anschließend wurde Poly(4-(3-oxobutyl)phenylmethacrylat) (PObMA) und Polybenzylmethacrylats (PBzMA) aus Massen- und L{\"o}sungspolymerisation hergestellt. Die Ausbeuten an PObpMA im Vergleich zum PBzMA liegen bei gleichen Reaktionsbedingungen auf gleichem Niveau. Im Kontrast hierzu ist der Polymerisationsgrad aus freier radikalischer Polymerisation in Masse des PObpMA im Vergleich zum PBzMA um den Faktor 3,7 gr{\"o}ßer. Die Glas{\"u}bergangstemperaturen des PObpMA liegen bei gleichen Reaktionsbedingungen sowohl bei freier radikalischer Polymerisation in Masse, als auch bei L{\"o}sungspolymerisation {\"u}ber denen des PBzMA. Dar{\"u}ber hinaus wurde die Polymerisation von 4-(3-Oxobutyl)phenylmethacrylat und Benzylmethacrylat mit einem Initiatorsystem bestehend aus Meerrettichperoxidase, Acetylaceton und Wasserstoffperoxid bei Raumtemperatur beschrieben. Die mit enzymatischem Initiatorsystem erzeugten Produkte zeigten starke {\"U}bereinstimmung mit Produkten aus L{\"o}sungspolymerisationen, welche mit Azobis(isobutyronitril) initiiert wurden.},
  language  = {de}
}
@phdthesis{Stoll2018,
  author    = {Stoll, Josefine},
  title     = {Gesundheitsmonitoring im Langstreckenmotorsport},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420880},
  school      = {Universit{\"a}t Potsdam},
  pages     = {117},
  year      = {2018},
  abstract  = {Professionelle GT Langstreckenmotorsportler (Rennfahrer) m{\"u}ssen den hohen motorischen und kognitiven Anspr{\"u}chen ohne Verlust der Performance w{\"a}hrend eines Rennens endgegenwirken k{\"o}nnen. Sie m{\"u}ssen stets, bei hoher Geschwindigkeit fokussiert und konzentriert auf ihr Auto, die Rennstrecke und ihre Gegner reagieren k{\"o}nnen. Dar{\"u}ber hinaus sind Rennfahrer zus{\"a}tzlich durch die notwendige Kommunikation im Auto mit den Ingenieuren und Mechanikern in der Boxengasse gefordert. Daten {\"u}ber die tats{\"a}chliche Beanspruchung und h{\"a}ufig auftretende Beschwerden und/oder Verletzung von Profiathleten liegen kaum vor. F{\"u}r eine m{\"o}glichst gute Performance im Auto w{\"a}hrend eines Rennens ist es notwendige neben der k{\"o}rperlichen Beanspruchung auch die h{\"a}ufigen Krankheitsbilder zu kennen. Auf Basis dessen kann eine optimale Pr{\"a}vention oder notwendige Therapie zur m{\"o}glichst schnellen Reintegration in den Sport abgeleitet und entwickelt werden. Die vorliegende Arbeit befasst sich durch ein regelm{\"a}ßiges Gesundheitsmonitoring mit der Erfassung h{\"a}ufiger Beschwerden und oder Verletzungen im GT Langestreckenmotorsport zur Ableitung eines pr{\"a}ventiven (trainingstherapeutischen) und therapeutischen Konzeptes. Dar{\"u}ber hinaus, soll {\"u}ber die Einsch{\"a}tzung der k{\"o}rperlichen Leistungsf{\"a}higkeit der Athleten, auf Basis der Beanspruchung im Rennfahrzeug ein m{\"o}gliches Trainingskonzept in Abh{\"a}ngigkeit der Saison entwickelt werden. Insgesamt wurden {\"u}ber 15 Jahre (2003-2017) 37 m{\"a}nnliche Athleten aus dem GT Langstreckenmotorsport 353mal im Rahmen eines Gesundheitsmonitorings untersucht. Dabei wurden Athleten maximal 14 Jahre und mindestens 1 Jahr sportmedizinische betreut. Diese 2x im Jahr stattfindende Untersuchung beinhaltete im Wesentlichen eine sportmedizinische Untersuchung zur Einsch{\"a}tzung der Tauglichkeit f{\"u}r den Sport und die Erfassung der k{\"o}rperlichen Leistungsf{\"a}higkeit. {\"U}ber das Gesundheitsmonitoring hinaus erfolgte die Betreuung zus{\"a}tzlich an der Rennstrecke zur weiteren Erfassung der Beschwerden, Erkrankungen und Verletzungen der Athleten w{\"a}hrend ihrer sportartspezifischen Belastung. Zusammengefasst zeigen die Athleten geringe Pr{\"a}valenzen und Inzidenzen der Krankheitsbilder bzw. Beschwerden. Ein Unterschied der Pr{\"a}valenzen zeigt sich zwischen den Gesundheitsuntersuchungen und der Betreuung an der Rennstrecke. Die h{\"a}ufigsten Beschwerdebilder zeigen sich aus Orthop{\"a}die und Innerer Medizin. So sind Infekte der oberen Atemwege sowie Allergien neben Beschwerden der unteren Extremit{\"a}t und der Wirbels{\"a}ule am h{\"a}ufigsten. Demzufolge werden vorrangig physio- und trainingstherapeutische Konsequenzen abgeleitet. Eine medikament{\"o}se Therapie erfolgt im Wesentlichen w{\"a}hrend der Rennbetreuung. Zur Reduktion der orthop{\"a}dischen und internistischen Beschwerden sollten pr{\"a}ventive Maßnahmen mehr betont werden. Die k{\"o}rperliche Leistungsf{\"a}higkeit zeigt im Wesentlichen {\"u}ber die Untersuchungsjahre eine stabile Performance f{\"u}r die Ausdauer-, Kraft und sensomotorische Leistungsf{\"a}higkeit. Die Ausdauerleistungsf{\"a}higkeit kann in Abh{\"a}ngigkeit der Sportartspezifik mit einer guten bis sehr guten Auspr{\"a}gung definiert werden. Die Kraftleistungsf{\"a}higkeit und die sensomotorische Leistungsf{\"a}higkeit lassen sportartspezifische Unterschiede zu und sollte k{\"o}rpergewichtsbezogen betrachtet werden. Ein sportmedizinisches und trainingstherapeutisches Konzept m{\"u}sste demnach eine regelm{\"a}ßige {\"a}rztlich-medizinische Untersuchung mit dem Fokus der Orthop{\"a}die, Inneren Medizin und Hals- Nasen-Ohren-Kunde beinhalten. Dar{\"u}ber hinaus sollte eine regelm{\"a}ßige Erfassung der k{\"o}rperlichen Leistungsf{\"a}higkeit zur m{\"o}glichst effektiven Ableitung von Trainingsinhalten oder Pr{\"a}ventionsmaßnahmen ber{\"u}cksichtig werden. Auf Grundlage der hohen Reiset{\"a}tigkeit und der ganzj{\"a}hrigen Saison k{\"o}nnte ein 1-2x j{\"a}hrlich stattfindendes Trainingslager, im Sinne eines Grundlagen- und Aufbautrainings zur Optimierung der Leistungsf{\"a}higkeit beitragen, das Konzept komplementieren. Zudem scheint eine {\"a}rztliche Rennbetreuung notwendig.},
  language  = {de}
}
@phdthesis{Beck2018,
  author    = {Beck, Christoph},
  title     = {Geschichtsphilosophie als Provokation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-410977},
  school      = {Universit{\"a}t Potsdam},
  pages     = {316},
  year      = {2018},
  abstract  = {In einer verschr{\"a}nkten Lekt{\"u}re von Curtius, Auerbach und Bachtin macht die Dissertation sichtbar, wie die Autoren mit ihren Arbeiten zur europ{\"a}ischen Literaturgeschichte nach einer ethischen Orientierung in der Krise der Moderne suchen. Ihr Konzept einer philologisch fundierten Geschichtsphilosophie in praktischer Absicht wird sowohl kultur- und theoriegeschichtlich aufbereitet, als auch anhand detaillierter Textanalysen nachvollzogen. Der Blick auf den geschichtsphilosophischen Aspekt ihrer Forschungsarbeit erweist sich hierbei nicht nur insoweit als fruchtbar, als er sich als Schl{\"u}ssel offenbart, philologische Mikrologie und breite Zusammenschau sowie ideengeschichtliche und gesellschaftliche Entwicklungen zu verkn{\"u}pfen. Ihr Ansatz offenbart sich auch als wesentlich differenzierter, als es die g{\"a}ngigen Vorbehalte gegen{\"u}ber der Geschichtsphilosophie vermuten lassen. Die Untersuchung erweitert aus diesem Grund den methodischen Diskurshorizont, indem sie die M{\"o}glichkeiten einer kritischen Geschichtsphilosophie f{\"u}r gegenw{\"a}rtige Fragen der Literaturgeschichte neu justiert. Dies geschieht {\"u}ber den Zugang so unterschiedlicher Rezeptionen wie der von Anselm Haverkamp, Edward Said, Terry Eagleton und Homi Bhabha, die einen Diskussionsraum er{\"o}ffnen, welcher den eigenen historischen Standpunkt der Dissertation im Kontext von Postmoderne und Postkolonialismus reflektiert.},
  language  = {de}
}
@phdthesis{Scholta2018,
  author    = {Scholta, Tobias},
  title     = {Georg Schneider und die {\"a}rztliche Selbstverwaltung in Brandenburg zwischen Deutschem Kaiserreich und Sowjetischer Besatzungszone},
  doi       = {10.25932/publishup-43020},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-430209},
  school      = {Universit{\"a}t Potsdam},
  pages     = {298},
  year      = {2018},
  abstract  = {Der am 15. Juni 1875 in Frankfurt (Oder) geborene und langj{\"a}hrig in seiner Wahlheimat Potsdam praktizierende Allgemeinmediziner Georg Otto Schneider war einer der bedeutendsten {\"a}rztlichen Standesvertreter der ersten H{\"a}lfte des 20. Jahrhunderts. Eng verkn{\"u}pft mit seinem Namen sind eine geradlinige, liberale Berufspolitik sowie die Entfaltung und der Erhalt beruflicher Selbstverwaltung in der brandenburgischen und gesamtdeutschen {\"A}rzteschaft. Als f{\"u}hrendes Mitglied in mehreren provinzialen und reichsweiten Verb{\"a}nden engagierte sich Schneider {\"u}ber vier historische Epochen stets im Sinne einer freien Aus{\"u}bung und autonomen Verwaltung des Arztberufes. Im Deutschen Kaiserreich war Schneiders standespolitisches Handeln zun{\"a}chst noch regional begrenzt. 1912 initiierte er die Errichtung eines Schutzverbandes f{\"u}r die {\"A}rzte des Bezirks Potsdam, dem er {\"u}ber zehn Jahre vorsaß. In der Weimarer Republik stieg Schneider sodann zu einer Schl{\"u}sselfigur der Gesundheits- und {\"a}rztlichen Berufspolitik auf. 1920 belebte er den {\"A}rzteverband f{\"u}r die Provinz Brandenburg, ab 1928 leitete er dazu in Personalunion die brandenburgische {\"A}rztekammer. Bereits zwei Jahre zuvor hatte er die Gesch{\"a}ftsf{\"u}hrung des Deutschen {\"A}rztevereinsbundes {\"u}bernommen. Infolge der Macht{\"u}bernahme der Nationalsozialisten schied Schneider bis Mitte 1934 aus allen {\"A}mtern aus, seine Bem{\"u}hungen f{\"u}r den Erhalt der Berufsautonomie waren vergebens. Anders sah es zun{\"a}chst nach Ende des Zweiten Weltkriegs aus. In der Sowjetischen Besatzungszone saß Schneider der Fachgruppe {\"A}rzte im Freien Deutschen Gewerkschaftsbund Brandenburg vor und verteidigte die M{\"o}glichkeiten der selbstst{\"a}ndigen Berufsverwaltung. Zudem war er von 1946 an bis zu seinem Tod am 26. Oktober 1949 Fraktionsvorsitzender der Liberal-Demokratischen Partei im brandenburgischen Landtag. Vor dem Hintergrund des Lebens und Wirkens Georg Schneiders untersucht die Dissertation Kontinuit{\"a}ten und Br{\"u}che im {\"a}rztlichen Organisationswesen, ausgehend vom Deutschen Kaiserreich {\"u}ber die Weimarer Epoche und den Nationalsozialismus bis hin zur Zeit der sowjetischen Besatzung. Die Arbeit stellt die Auswirkungen der jeweiligen politischen, sozio{\"o}konomischen und gesellschaftlichen Entwicklungen auf den {\"A}rztestand und die entsprechenden Reaktionen der {\"a}rztlichen Berufsvertreter, allen voran Georg Schneiders, gegen{\"u}ber. Dabei hinterfragt sie, inwiefern sich die {\"a}rztlichen Organisationsstrukturen dem jeweiligen System anpassten und welchen Einfluss Schneider als einzelne Person in den gr{\"o}ßeren Institutionen entfalten konnte.},
  language  = {de}
}
@phdthesis{Bertz2018,
  author    = {Bertz, Martin},
  title     = {Funktion von Selenoproteinen  w{\"a}hrend der kolorektalen Karzinogenese},
  doi       = {10.25932/publishup-42780},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427808},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VII, 109},
  year      = {2018},
  abstract  = {Kolorektalkrebs (CRC) ist die dritth{\"a}ufigste Tumorerkrankung weltweit. Neben dem Alter spielt auch die Ern{\"a}hrung eine wichtige Rolle bei der Entstehung der Krankheit. Eine vermutlich krebspr{\"a}ventive Wirkung wird dabei dem Spurenelement Selen zugeschrieben, das fast ausschließlich {\"u}ber Lebensmittel aufgenommen wird. So h{\"a}ngt beispielsweise ein niedriger Selenstatus mit dem Risiko, im Laufe des Lebens an CRC zu erkranken, zusammen. Seine Funktionen vermittelt Selen dabei {\"u}berwiegend durch Selenoproteine, in denen es in Form von Selenocystein eingebaut wird. Zu den bisher am besten untersuchten Selenoproteinen mit m{\"o}glicher Funktion w{\"a}hrend CRC z{\"a}hlen die Glutathionperoxidasen (GPXen). Die Mitglieder dieser Familie tragen aufgrund ihrer Hydroperoxid-reduzierenden Eigenschaften entscheidend zum Schutz der Zellen vor oxidativem Stress bei. Dies kann je nach Art und Stadium des Tumors entweder krebshemmend oder -f{\"o}rdernd wirken, da auch transformierte Zellen von dieser Schutzfunktion profitieren. In dieser Arbeit wurde die GPX2 in HT29-Darmkrebszellen mithilfe stabil-transfizierter shRNA herunterreguliert, um die Funktion des Enzyms vor allem in Hinblick auf regulierte Signalwege zu untersuchen. Ein Knockdowns (KD) der strukturell {\"a}hnlichen GPX1 kam ebenfalls zum Einsatz, um gezielt Isoform-spezifische Funktionen unterscheiden zu k{\"o}nnen. Anhand eines PCR-Arrays wurden Signalwege identifiziert, die auf einen Einfluss der beiden Proteine im Zellwachstum hindeuteten. Anschließende Untersuchungen ließen auf einen verminderten Differenzierungsstatus in den GPX1- und GPX2-KDs aufgrund einer geringeren Aktivit{\"a}t der Alkalischen Phosphatase schließen. Zudem war die Zellviabilit{\"a}t im Neutralrot-Assay (NRU) bei Fehlen der GPX1 bzw. GPX2 im Vergleich zur Kontrolle reduziert. Die Ergebnisse des PCR-Arrays, und speziell f{\"u}r die GPX2 fr{\"u}here Untersuchungen der Arbeitsgruppe, wiesen weiterhin auf eine Rolle der beiden Proteine in der entz{\"u}ndungsgetriebenen Karzinogenese hin. Daher wurden auch m{\"o}gliche Interaktionen mit dem NFκB-Signalweg analysiert. Eine Stimulation der Zellen mit dem proinflammatorischen Zytokin IL1β ging mit einer verst{\"a}rkten Aktivierung der MAP-Kinasen ERK1/2 in den Zellen mit GPX1- bzw. GPX2-KD einher. Die gleichzeitige Behandlung mit dem Antioxidans NAC f{\"u}hrte nicht zur R{\"u}cknahme der Effekte in den KDs, sodass m{\"o}glicherweise nicht nur die antioxidativen Eigenschaften der Enzyme bei der Interaktion mit diesen Signalwegsproteinen relevant sind. Weiterhin wurden Analysen zum Substratspektrum der GPX2 in HCT116-Zellen mit einer {\"U}berexpression des Proteins durchgef{\"u}hrt. Dabei zeigte sich mittels NRU-Assay und DNA-Laddering, dass die GPX2 besonders vor den proapoptotischen Effekten einer Behandlung mit den Lipidhydroperoxiden HPODE und HPETE sch{\"u}tzt. Im Gegensatz zur GPX2 l{\"a}sst sich Selenoprotein H (SELENOH) st{\"a}rker durch die aliment{\"a}re Selenzufuhr beeinflussen. Einer m{\"o}glichen Nutzung als Biomarker oder gar als Ansatzpunkt bei der Pr{\"a}vention bzw. Behandlung von CRC steht allerdings unvollst{\"a}ndiges Wissen {\"u}ber die Funktion des Proteins gegen{\"u}ber. Zur genaueren Charakterisierung von SELENOH wurden daher stabil-transfizierte KD-Klone in HT29- und Caco2-Zellen hergestellt und zun{\"a}chst auf ihre Tumorigenit{\"a}t untersucht. Zellen mit SELENOH-KD bildeten mehr und gr{\"o}ßere Kolonien im Soft Agar und zeigten ein erh{\"o}htes Proliferations- und Migrationspotenzial im Vergleich zur Kontrolle. Ein Xenograft in Nacktm{\"a}usen resultierte zudem in einer st{\"a}rkeren Tumorbildung nach Injektion von KD-Zellen. Untersuchungen zur Beteiligung von SELENOH an der Zellzyklusregulation deuten auf eine hemmende Rolle des Proteins in der G1/S-Phase hin. Die weiterhin beobachtete Hochregulation von SELENOH in humanen Adenokarzinomen und pr{\"a}kanzer{\"o}sem Mausgewebe l{\"a}sst sich m{\"o}glicherweise mit der postulierten Schutzfunktion vor oxidativen Zell- und DNA-Sch{\"a}den erkl{\"a}ren. In gesunden Darmepithelzellen war das Protein vorrangig am Kryptengrund lokalisiert, was zu einer potenziellen Rolle w{\"a}hrend der gastrointestinalen Differenzierung passt.},
  language  = {de}
}
@phdthesis{Walther2018,
  author    = {Walther, Sebastian},
  title     = {Funktionalisierung von {\"O}ls{\"a}uremethylester und Alkydharzen f{\"u}r die photoinduzierte radikalische Polymerisation im UV Bereich},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421467},
  school      = {Universit{\"a}t Potsdam},
  pages     = {136},
  year      = {2018},
  abstract  = {Die vorliegende Arbeit behandelt die Synthese und Charakterisierung von funktionalisierten Alkydharzen und die photoinduzierte Polymerisation dieser unter Einsatz einer Quecksilberdampflampe oder einer UV LED mit unterschiedlicher Lichtintensit{\"a}t. Der Fokus dieser Arbeit bestand in der gezielten Substitution der internalen Doppelbindungen der Fetts{\"a}ureester durch reaktivere Gruppen, wie Acrylate oder Methacrylate, welche f{\"u}r Alkydharze in dieser Form so in der Literatur nicht beschrieben sind. Untersuchungen des Polymerisationsverhaltens dieser funktionalisierten Harze wurden mit der Photo DSC durchgef{\"u}hrt, wobei Bis - (4 - methoxybenzoyl) diethylgermanium als Photoinitiator diente. Die Ergebnisse haben gezeigt, dass die Harze radikalisch polymerisiert werden k{\"o}nnen und eine geringere Abh{\"a}ngigkeit von der Umgebungsatmosph{\"a}re (Luftsauerstoff bzw. Stickstoff) vorliegt. Dies ist so in der Literatur f{\"u}r funktionalisierte Alkydharze nicht bekannt. Abmischungen von unterschiedlichen Monomeren und funktionalisierten Harzen bewirkten eine Steigerung der Viskosit{\"a}t sowie eine Verringerung der Sauerstoffinhibierung im Zuge der photoinduzierten Polymerisation unter Luftsauerstoff f{\"u}r die Quecksilberdampflampe und der UV LED. Zur Untersuchung der sauerstoffinhibierenden Wirkung der Harze sind Synthesen unterschiedlicher, funktionalisierter {\"O}ls{\"a}uremethylester als Modellsubstanzen durchgef{\"u}hrt worden. Ein verbessertes Polymerisationsverhalten und eine geringe Abh{\"a}ngigkeit von der Umgebungsatmosph{\"a}re konnte f{\"u}r die Modelle nachgewiesen werden. Zur Aufkl{\"a}rung des verbesserten Polymerisationsverhaltens sind gezielt Substituenten (Imidazol, Brom, Alkohol, Acetat) in den funktionalisierten {\"O}ls{\"a}uremethylester eingebaut worden, um den Einfluss dieser aufzuzeigen. Im Rahmen dieser Synthesen sind neuartige Strukturen synthetisiert worden, welche so in der Literatur nicht beschrieben sind. Die Gegen{\"u}berstellung der Polymerisationszeit, der Umsatz der (Meth-)Acrylatgruppen sowie die Zeit zum Erreichen der maximalen Polymerisationsgeschwindigkeit unter Verwendung von unterschiedlichen UV Lichtquellen hat einen Einfluss der Substituenten auf das Polymerisationsverhalten gezeigt.},
  language  = {de}
}
@phdthesis{Lama2018,
  author    = {Lama, Sandy M. G.},
  title     = {Functionalization of Porous Carbon Materials with Heteroatoms and Application as Supports in Industrial Heterogeneous Catalysis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-415797},
  school      = {Universit{\"a}t Potsdam},
  pages     = {124},
  year      = {2018},
  abstract  = {Due to a challenging population growth and environmental changes, a need for new routes to provide required chemicals for human necessities arises. An effective solution discussed in this thesis is industrial heterogeneous catalysis. The development of an advanced industrial heterogeneous catalyst is investigated herein by considering porous carbon nano-material as supports and modifying their surface chemistry structure with heteroatoms. Such modifications showed a significant influence on the performance of the catalyst and provided a deeper insight regarding the interaction between the surface structure of the catalyst and the surrounding phase. This thesis contributes to the few present studies about heteroatoms effect on the catalyst performance and emphasizes on the importance of understanding surface structure functionalization in a catalyst in different phases (liquid and gaseous) and for different reactions (hydrogenolysis, oxidation, and hydrogenation/ polymerization). Herein, the heteroatoms utilized for the modifications are hydrogen (H), oxygen (O), and nitrogen (N). The heteroatoms effect on the metal particle size, on the polarity of the support/ the catalyst, on the catalytic performance (activity, selectivity, and stability), and on the interaction with the surrounding phase has been explored. First hierarchical porous carbon nanomaterials functionalized with heteroatoms (N) is synthesized and applied as supports for nickel nanoparticles for hydrogenolysis process of kraft lignin in liquid phase. This reaction has been performed in batch and flow reactors for three different catalysts, two of comparable hierarchical porosity, yet one is modified with N and the other is not, and a third is a prepared catalyst from a commercial carbon support. The reaction production and analyses show that the catalysts with hierarchical porosity perform catalytically much better than in presence of a commercial carbon support with lower surface area. Moreover, the modification with N-heteroatoms enhanced the catalytic performance because the heteroatom modified porous carbon material with nickel nanoparticles catalyst (Ni-NDC) performed highest among the other catalysts. In the flow reactor, Ni-NDC selectively degraded the ether bonds (β-O-4) in kraft lignin with an activity of 2.2 x10^-4 mg lignin mg Ni-1 s-1 for 50 h at 350°C and 3.5 mL min-1 flow, providing ~99 \% conversion to shorter chained chemicals (mainly guaiacol derivatives). Then, the functionalization of carbon surface was further studied in selective oxidation of glucose to gluconic acid using < 1 wt. \% of gold (Au) deposited on the previously-mentioned synthesized carbon (C) supports with different functionalities (Au-CGlucose, Au-CGlucose-H, Au-CGlucose-O, Au-CGlucoseamine). Except for Au-CGlucose-O, the other catalysts achieved full glucose conversion within 40-120 min and 100\% selectivity towards gluconic acid with a maximum activity of 1.5 molGlucose molAu-1 s-1 in an aqueous phase at 45 °C and pH 9. Each heteroatom influenced the polarity of the carbon differently, affecting by that the deposition of Au on the support and thus the activity of the catalyst and its selectivity. The heteroatom effect was further investigated in a gas phase. The Fischer-Tropsch reaction was applied to convert synthetic gas (CO and H2) to short olefins and paraffins using surface-functionalized carbon nanotubes (CNTs) with heteroatoms as supports for ion (Fe) deposition in presence and absence of promoters (Na and S). The results showed the promoted Fe-CNT doped with nitrogen catalyst to be stable up to 180 h and selective to the formation of olefins (~ 47 \%) and paraffins (~6 \%) with a conversion of CO ~ 92 \% at a maximum activity of 94 *10^-5 mol CO g Fe-1 s-1. The more information given regarding this topic can open wide range of applications not only in catalysis, but in other approaches as well. In conclusion, incorporation of heteroatoms can be the next approach for an advanced industrial heterogeneous catalyst, but also for other applications (e.g. electrocatalysis, gas adsorption, or supercapacitors).},
  language  = {en}
}
@phdthesis{Przybylla2018,
  author    = {Przybylla, Mareen},
  title     = {From Embedded Systems to Physical Computing: Challenges of the "Digital World" in Secondary Computer Science Education},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418339},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvii, 277},
  year      = {2018},
  abstract  = {Physical computing covers the design and realization of interactive objects and installations and allows learners to develop concrete, tangible products of the real world, which arise from their imagination. This can be used in computer science education to provide learners with interesting and motivating access to the different topic areas of the subject in constructionist and creative learning environments. However, if at all, physical computing has so far mostly been taught in afternoon clubs or other extracurricular settings. Thus, for the majority of students so far there are no opportunities to design and create their own interactive objects in regular school lessons. Despite its increasing popularity also for schools, the topic has not yet been clearly and sufficiently characterized in the context of computer science education. The aim of this doctoral thesis therefore is to clarify physical computing from the perspective of computer science education and to adequately prepare the topic both content-wise and methodologically for secondary school teaching. For this purpose, teaching examples, activities, materials and guidelines for classroom use are developed, implemented and evaluated in schools. In the theoretical part of the thesis, first the topic is examined from a technical point of view. A structured literature analysis shows that basic concepts used in physical computing can be derived from embedded systems, which are the core of a large field of different application areas and disciplines. Typical methods of physical computing in professional settings are analyzed and, from an educational perspective, elements suitable for computer science teaching in secondary schools are extracted, e. g. tinkering and prototyping. The investigation and classification of suitable tools for school teaching show that microcontrollers and mini computers, often with extensions that greatly facilitate the handling of additional components, are particularly attractive tools for secondary education. Considering the perspectives of science, teachers, students and society, in addition to general design principles, exemplary teaching approaches for school education and suitable learning materials are developed and the design, production and evaluation of a physical computing construction kit suitable for teaching is described. In the practical part of this thesis, with "My Interactive Garden", an exemplary approach to integrate physical computing in computer science teaching is tested and evaluated in different courses and refined based on the findings in a design-based research approach. In a series of workshops on physical computing, which is based on a concept for constructionist professional development that is developed specifically for this purpose, teachers are empowered and encouraged to develop and conduct physical computing lessons suitable for their particular classroom settings. Based on their in-class experiences, a process model of physical computing teaching is derived. Interviews with those teachers illustrate that benefits of physical computing, including the tangibility of crafted objects and creativity in the classroom, outweigh possible drawbacks like longer preparation times, technical difficulties or difficult assessment. Hurdles in the classroom are identified and possible solutions discussed. Empirical investigations in the different settings reveal that "My Interactive Garden" and physical computing in general have a positive impact, among others, on learner motivation, fun and interest in class and perceived competencies. Finally, the results from all evaluations are combined to evaluate the design principles for physical computing teaching and to provide a perspective on the development of decision-making aids for physical computing activities in school education.},
  language  = {en}
}
@phdthesis{Stolley2018,
  author    = {Stolley, Florian},
  title     = {Four essays on altruism and compliance},
  doi       = {10.25932/publishup-42801},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-428013},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ix, 129},
  year      = {2018},
  abstract  = {There are numerous situations in which people ask for something or make a request, e.g. asking a favor, asking for help or requesting compliance with specific norms. For this reason, how to ask for something in order to increase people's willingness to fulfill such requests is one of the most important question for many people working in various different fields of responsibility such as charitable giving, marketing, management or policy making. This dissertation consists of four chapters that deal with the effects of small changes in the decision-making environment on altruistic decision-making and compliance behavior. Most notably, written communication as an influencing factor is the focus of the first three chapters. The starting point was the question how to devise a request in order to maximize its chance of success (Chapter 1). The results of the first chapter originate the ideas for the second and third chapter. Chapter 2 analyzes how communication by a neutral third-party, i.e. a text from the experimenters that either reminds potential benefactors of their responsibility or highlights their freedom of choice, affects altruistic decision-making. Chapter 3 elaborates on the effect of thanking people in advance when asking them for help. While being not as closely related to the other chapters as the three first ones are, the fourth chapter deals as well with the question how compliance (here: compliance with norms and rules) is affected by subtle manipulations of the environment in which decisions are made. This chapter analyzes the effect of default settings in a tax return on tax compliance. In order to study the research questions outlined above, controlled experiments were conducted. Chapter 1, which analyzes the effect of text messages on the decision to give something to another person, employs a mini-dictator game. The recipient sends a free-form text message to the dictator before the latter makes a binary decision whether or not to give part of her or his endowment to the recipient. We find that putting effort into the message by writing a long note without spelling mistakes increases dictators' willingness to give. Moreover, writing in a humorous way and mentioning reasons why the money is needed pays off. Furthermore, men and women seem to react differently to some message categories. Only men react positively to efficiency arguments, while only women react to messages that emphasize the dictator's power and responsibility. Building on this last result, Chapter 2 attempts to disentangle the effect of reminding potential benefactors of their responsibility for the potential beneficiary and the effect of highlighting their decision power and freedom of choice on altruistic decision-making by studying the effects of two different texts on giving in a dictator game. We find that only men react positively to a text that stresses their responsibility for the recipient by giving more to her or him, whereas only women seem to react positively to a text that emphasizes their decision power and freedom of choice. Chapter 3 focuses on the compliance with a request. In the experiment, participants are asked to provide a detailed answer to an open question. Compliance is measured by the effort participants spend on answering the question. The treatment variable is whether or not they see the text "thanks in advance." We find that participants react negatively by putting less effort into complying with the request in response to the phrase "thanks in advance." Chapter 4 studies the effect of prefilled tax returns with mostly inaccurate default values on tax compliance. In a laboratory experiment, participants earn income by performing a real-effort task and must subsequently file a tax return for three consecutive rounds. In the main treatment, the tax return is prefilled with a default value, resulting from participants' own performance in previous rounds, which varies in its relative size. The results suggest that there is no lasting effect of a default value on tax honesty, neither for relatively low nor relatively high defaults. However, participants who face a default that is lower than their true income in the first round evade significantly and substantially more taxes in this round than participants in the control treatment without a default.},
  language  = {en}
}
@phdthesis{Stettner2018,
  author    = {Stettner, Samuel},
  title     = {Exploring the seasonality of rapid Arctic changes from space},
  doi       = {10.25932/publishup-42578},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-425783},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XIII, 132},
  year      = {2018},
  abstract  = {Arctic warming has implications for the functioning of terrestrial Arctic ecosystems, global climate and socioeconomic systems of northern communities. A research gap exists in high spatial resolution monitoring and understanding of the seasonality of permafrost degradation, spring snowmelt and vegetation phenology. This thesis explores the diversity and utility of dense TerraSAR-X (TSX) X-Band time series for monitoring ice-rich riverbank erosion, snowmelt, and phenology of Arctic vegetation at long-term study sites in the central Lena Delta, Russia and on Qikiqtaruk (Herschel Island), Canada. In the thesis the following three research questions are addressed: • Is TSX time series capable of monitoring the dynamics of rapid permafrost degradation in ice-rich permafrost on an intra-seasonal scale and can these datasets in combination with climate data identify the climatic drivers of permafrost degradation? • Can multi-pass and multi-polarized TSX time series adequately monitor seasonal snow cover and snowmelt in small Arctic catchments and how does it perform compared to optical satellite data and field-based measurements? • Do TSX time series reflect the phenology of Arctic vegetation and how does the recorded signal compare to in-situ greenness data from RGB time-lapse camera data and vegetation height from field surveys? To answer the research questions three years of TSX backscatter data from 2013 to 2015 for the Lena Delta study site and from 2015 to 2017 for the Qikiqtaruk study site were used in quantitative and qualitative analysis complimentary with optical satellite data and in-situ time-lapse imagery. The dynamics of intra-seasonal ice-rich riverbank erosion in the central Lena Delta, Russia were quantified using TSX backscatter data at 2.4 m spatial resolution in HH polarization and validated with 0.5 m spatial resolution optical satellite data and field-based time-lapse camera data. Cliff top lines were automatically extracted from TSX intensity images using threshold-based segmentation and vectorization and combined in a geoinformation system with manually digitized cliff top lines from the optical satellite data and rates of erosion extracted from time-lapse cameras. The results suggest that the cliff top eroded at a constant rate throughout the entire erosional season. Linear mixed models confirmed that erosion was coupled with air temperature and precipitation at an annual scale, seasonal fluctuations did not influence 22-day erosion rates. The results highlight the potential of HH polarized X-Band backscatter data for high temporal resolution monitoring of rapid permafrost degradation. The distinct signature of wet snow in backscatter intensity images of TSX data was exploited to generate wet snow cover extent (SCE) maps on Qikiqtaruk at high temporal resolution. TSX SCE showed high similarity to Landsat 8-derived SCE when using cross-polarized VH data. Fractional snow cover (FSC) time series were extracted from TSX and optical SCE and compared to FSC estimations from in-situ time-lapse imagery. The TSX products showed strong agreement with the in-situ data and significantly improved the temporal resolution compared to the Landsat 8 time series. The final combined FSC time series revealed two topography-dependent snowmelt patterns that corresponded to in-situ measurements. Additionally TSX was able to detect snow patches longer in the season than Landsat 8, underlining the advantage of TSX for detection of old snow. The TSX-derived snow information provided valuable insights into snowmelt dynamics on Qikiqtaruk previously not available. The sensitivity of TSX to vegetation structure associated with phenological changes was explored on Qikiqtaruk. Backscatter and coherence time series were compared to greenness data extracted from in-situ digital time-lapse cameras and detailed vegetation parameters on 30 areas of interest. Supporting previous results, vegetation height corresponded to backscatter intensity in co-polarized HH/VV at an incidence angle of 31°. The dry, tall shrub dominated ecological class showed increasing backscatter with increasing greenness when using the cross polarized VH/HH channel at 32° incidence angle. This is likely driven by volume scattering of emerging and expanding leaves. Ecological classes with more prostrate vegetation and higher bare ground contributions showed decreasing backscatter trends over the growing season in the co-polarized VV/HH channels likely a result of surface drying instead of a vegetation structure signal. The results from shrub dominated areas are promising and provide a complementary data source for high temporal monitoring of vegetation phenology. Overall this thesis demonstrates that dense time series of TSX with optical remote sensing and in-situ time-lapse data are complementary and can be used to monitor rapid and seasonal processes in Arctic landscapes at high spatial and temporal resolution.},
  language  = {en}
}
@phdthesis{Leser2018,
  author    = {Leser, Eva},
  title     = {Eta Carinae},
  doi       = {10.25932/publishup-42814},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-428141},
  school      = {Universit{\"a}t Potsdam},
  pages     = {X, 117},
  year      = {2018},
  abstract  = {Das außergew{\"o}hnliche Doppelsternsystem Eta Carinae fasziniert WissenschaftlerInnen und BeobachterInnen auf der s{\"u}dlichen Erdhalbkugel seit hunderten Jahren. Nach einem Supernova-{\"a}hnlichem Ausbruch war Eta Carinae zeitweise der hellste Stern am Nachthimmel. Heute sind durch zahlreiche Beobachtungen, von Radiowellen bis zu R{\"o}ntgenstrahlung, der Aufbau des Sternsystems und die Eigenschaften seiner Strahlung bis zu Energien von ~ 50 keV gut erforscht. Das Doppelsternsystem besteht aus zwei massiven Sternen (~ 30 und ~ 100 Sonnenmassen Gewicht) mit starken Sternwinden, {\"u}ber die sie kontinuierlich einen Teil ihrer Masse verlieren. Wenn diese Sternwinde kollidieren, entsteht auf beiden Seiten ein Kompressionsschock der das Plasma in der Kollisionszone aufheizt, was sich in R{\"o}ntgenstrahlung beobachten l{\"a}sst. Bei Energien oberhalb von ~ 50 keV ist der Ursprung der Strahlung nicht mehr thermisch: um ein Plasma auf die entsprechende Temperatur zu bringen, wird mehr mechanische Energie ben{\"o}tigt, als in den Sternwinden vorhanden. In hoch-energetischer Gamma-Strahlung ist Eta Carinae das einzige eindeutig detektierte Sternsystem seiner Art und sein Energiespektrum reicht bis zu ~ hundert GeV. Bodengebundene Gamma-Strahlungsexperimente haben in diesem Energiebereich den Vorteil von großen Detektorfl{\"a}chen. H.E.S.S. ist das einzige bodengebundene Gamma-Strahlungsexperiment auf der S{\"u}dhalbkugel und somit in der Lage, Eta Carinae in diesen Energien zu beobachten. H.E.S.S. misst Gamma-Strahlung mit Hilfe der elektromagnetischen Teilchenschauer, die sehr hoch-energetische Photonen in der Atmosph{\"a}re ausl{\"o}sen. Die gr{\"o}ßte Herausforderung der Messung von Eta Carinaes Strahlung mit H.E.S.S. ist die ultraviolette Strahlung des Carina Nebels, die zu einem Hintergrund f{\"u}hrt, der bis zu zehn mal st{\"a}rker ist als der Durchschnitt in H.E.S.S. In dieser Arbeit wird die erste Detektion eines Doppelsternsystems mit kollidierenden Sternwinden in sehr hoch-energetischer Gamma-Strahlung pr{\"a}sentiert und die Studien, die diese erm{\"o}glicht haben. Das differentielle Gamma-Strahlungsspektrum bis 700 GeV wird untersucht. Hadronische und leptonische Szenarios f{\"u}r den Ursprung der Gamma-Strahlung werden diskutiert und das hadronische Szenario wird aufgrund eines Vergleichs der K{\"u}hlzeiten bevorzugt.},
  language  = {en}
}
@phdthesis{Konon2018,
  author    = {Konon, Alexander},
  title     = {Essays on career choice under risk and ambiguity},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-416466},
  school      = {Universit{\"a}t Potsdam},
  pages     = {x, 250, xxxv},
  year      = {2018},
  abstract  = {This dissertation consists of five self-contained essays, addressing different aspects of career choices, especially the choice of entrepreneurship, under risk and ambiguity. In Chapter 2, the first essay develops an occupational choice model with boundedly rational agents, who lack information, receive noisy feedback, and are restricted in their decisions by their personality, to analyze and explain puzzling empirical evidence on entrepreneurial decision processes. In the second essay, in Chapter 3, I contribute to the literature on entrepreneurial choice by constructing a general career choice model on the basis of the assumption that outcomes are partially ambiguous. The third essay, in Chapter 4, theoretically and empirically analyzes the impact of media on career choices, where information on entrepreneurship provided by the media is treated as an informational shock affecting prior beliefs. The fourth essay, presented in Chapter 5, contains an empirical analysis of the effects of cyclical macro variables (GDP and unemployment) on innovative start-ups in Germany. In the fifth, and last, essay in Chapter 6, we examine whether information on personality is useful for advice, using the example of career advice.},
  language  = {en}
}
@phdthesis{Wulff2018,
  author    = {Wulff, Alexander},
  title     = {Essays in macroeconomics and financial market imperfections},
  doi       = {10.25932/publishup-42995},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-429956},
  school      = {Universit{\"a}t Potsdam},
  pages     = {X, 142},
  year      = {2018},
  abstract  = {This dissertation consists of four self-contained papers that deal with the implications of financial market imperfections and heterogeneity. The analysis mainly relates to the class of incomplete-markets models but covers different research topics. The first paper deals with the distributional effects of financial integration for developing countries. Based on a simple heterogeneous-agent approach, it is shown that capital owners experience large welfare losses while only workers moderately gain due to higher wages. The large welfare losses for capital owners contrast with the small average welfare gains from representative-agent economies and indicate that a strong opposition against capital market opening has to be expected. The second paper considers the puzzling observation of capital flows from poor to rich countries and the accompanying changes in domestic economic development. Motivated by the mixed results from the literature, we employ an incomplete-markets model with different types of idiosyncratic risk and borrowing constraints. Based on different scenarios, we analyze under what conditions the presence of financial market imperfections contributes to explain the empirical findings and how the conditions may change with different model assumptions. The third paper deals with the interplay of incomplete information and financial market imperfections in an incomplete-markets economy. In particular, it analyzes the impact of incomplete information about idiosyncratic income shocks on aggregate saving. The results show that the effect of incomplete information is not only quantitatively substantial but also qualitatively ambiguous and varies with the influence of the income risk and the borrowing constraint. Finally, the fourth paper analyzes the influence of different types of fiscal rules on the response of key macroeconomic variables to a government spending shock. We find that a strong temporary increase in public debt contributes to stabilizing consumption and leisure in the first periods following the change in government spending, whereas a non-debt-intensive fiscal rule leads to a faster recovery of consumption, leisure, capital and output in later periods. Regarding optimal debt policy, we find that a debt-intensive fiscal rule leads to the largest aggregate welfare benefit and that the individual welfare gain is particularly high for wealth-poor agents.},
  language  = {en}
}
@phdthesis{Grunert2018,
  author    = {Grunert, Bianca},
  title     = {Entwicklung von Markierungsreagenzien f{\"u}r die bildgebende Diagnostik},
  doi       = {10.25932/publishup-42283},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-422830},
  school      = {Universit{\"a}t Potsdam},
  pages     = {155},
  year      = {2018},
  abstract  = {Die intrazellul{\"a}re Markierung mit geeigneten Reagenzien erm{\"o}glicht ihre bildgebende Darstellung in lebenden Organismen. Dieses Verfahren (auch „Zell-Tracking" genannt) wird in der Grundlagenforschung zur Entwicklung zellul{\"a}rer Therapien, f{\"u}r die Erforschung pathologischer Prozesse, wie der Metastasierung, sowie f{\"u}r Therapiekontrollen eingesetzt. Besondere Bedeutung haben in den letzten Jahren zellul{\"a}re Therapien mit Stammzellen erlangt, da sie großes Potential bei der Regeneration von Geweben bei Krankheiten wie Morbus Parkinson oder Typ-1-Diabetes versprechen. F{\"u}r die Entwicklung einer zellul{\"a}ren Therapie sind Informationen {\"u}ber den Verbleib der applizierten Zellen in vivo (Homing-Potential), {\"u}ber ihre Zellphysiologie sowie {\"u}ber die Entstehung m{\"o}glicher Entz{\"u}ndungen notwendig. Das Ziel der vorliegenden Arbeit war daher die Synthese von Markierungsreagenzien, die nicht nur eine effiziente Zellmarkierung erm{\"o}glichen, sondern einen synergistischen Effekt hinsichtlich des modalit{\"a}ts{\"u}bergreifenden Einsatzes in den bildgebenden Verfahren MRT und Laser-Ablation(LA)-ICP-MS erlauben. Die MRT-Bildgebung erm{\"o}glicht die nicht invasive Nachverfolgung markierter Zellen in vivo und die LA-ICP-MS die anschließende ex vivo Analytik zur Darstellung der Elementverteilung (Bioimaging) in einer Biopsieprobe oder in einem Gewebeschnitt. F{\"u}r diese Zwecke wurden zwei verschiedene Markierungsreagenzien mit dem kontrastgebenden Element Gadolinium synthetisiert. Gadolinium eignet sich aufgrund seines hohen magnetischen Moments hervorragend f{\"u}r die MRT-Bildgebung und da es in Biomolek{\"u}len nicht nat{\"u}rlich vorkommt, konnten die Reagenzien gleichermaßen f{\"u}r die Zellmarkierung und das Bioimaging mit der LA-ICP-MS untersucht werden. F{\"u}r die Synthese eines makromolekularen Reagenzes wurde das kommerziell verf{\"u}gbare Dendrimer G5-PAMAM {\"u}ber bifunktionelle Linker mit dem Chelator DOTA funktionalisiert, um anschließend Gadolinium zu komplexieren. Ein zweites, nanopartikul{\"a}res Reagenz wurde {\"u}ber eine Solvothermal-Synthese erhalten, bei der Ln:GdVO4-Nanokristalle mit einer funktionellen Polyacryls{\"a}ure(PAA)-H{\"u}lle dargestellt wurden. Die Dotierung der Ln:GdVO4-PAA Nanokristalle mit verschiedenen Lanthanoiden (Ln=Eu, Tb) zeigte ihre prinzipielle Multiplexf{\"a}higkeit in der LA-ICP-MS. Beide Markierungsreagenzien zeichneten sich durch gute Biovertr{\"a}glichkeiten und r1-Relaxivit{\"a}ten aus, was zudem ihr Potential f{\"u}r Anwendungen als pr{\"a}klinische „blood-pool" MRT-Kontrastmittel belegte. Die Untersuchung der Zellmarkierung erfolgte anhand einer Tumorzelllinie und einer Stammzelllinie, wobei beide Zellarten erfolgreich intrazellul{\"a}r mit beiden Reagenzien markiert wurden. Nach der Zellmarkierung veranschaulichte die in vitro MRT-Bildgebung von Zell-Phantomen eine deutlichere Kontrastverst{\"a}rkung der Zellen nach der Markierung mit den Nanokristallen im Vergleich zum kommerziellen Kontrastmittel Magnevist®. Die hohe Effizienz der Zellmarkierung mit den Nanokristallen und die damit verbundenen hohen Signalintensit{\"a}ten in einer einzelnen Zelle erlaubten beim Bioimaging mit der LA-ICP-MS, Messungen bis zu einer Aufl{\"o}sung von 4 µm Laser Spot Size. Nach der Zellmarkierung mit den DOTA(Gd3+)-funktionalisierten G5-PAMAM Dendrimeren waren hingegen Aufnahmen mit der LA-ICP-MS nur bis zu einer Aufl{\"o}sung von 12 µm Laser Spot Size m{\"o}glich. Insgesamt waren die Ln:GdVO4-PAA Nanokristalle mit gr{\"o}ßerer Ausbeute und kosteng{\"u}nstiger herstellbar als die DOTA(Gd3+)-funktionalisierten G5-PAMAM Dendrimere und zeigten zudem eine effizientere Zellmarkierung. Die Ln:GdVO4-PAA Nanokristalle erscheinen somit f{\"u}r das Zell-Tracking als besonders vielversprechend. Darauf aufbauend wurden die Nanokristalle zur Etablierung der Antik{\"o}rper-Konjugation ausgew{\"a}hlt, was sie f{\"u}r die molekulare in vivo Bildgebung sowie f{\"u}r die Immuno-Bildgebung von Gewebeschnitten oder Biopsie-Proben mit der LA-ICP-MS anwendbar macht.},
  language  = {de}
}
@phdthesis{Schulze2018,
  author    = {Schulze, Sven},
  title     = {Entwicklung und Charakterisierung optischer Biosensorplattformen basierend auf photonischen Kristallen und Faser-Bragg-Gitter},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-422139},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xviii, 149, A-23, B-2, C-8},
  year      = {2018},
  abstract  = {In dieser Arbeit steht die Entwicklung einer Sensorplattform f{\"u}r biochemische Anwendungen, welche auf einem optischen Detektionsprinzips beruht, im Vordergrund. W{\"a}hrend der Entwicklung wurden zwei komplement{\"a}re Konzeptideen behandelt, zum einen ein Sensor, der auf photonischen Kristallen und Wellenleiterstrukturen basiert und zum anderen einen faserbasierten Sensor, der chemisch modifizierte Faser-Bragg-Gitter enth{\"a}lt. Das optische Detektionsprinzip in beiden Sensorideen ist die resultierende Brechungsindex{\"a}nderung als messbare physikochemische Kenngr{\"o}ße. Das aus der Natur bekannte Ph{\"a}nomen der photonischen Kristalle, das u. a. bei Opalen und bei Schmetterlingen zu finden ist, wurde bereits 1887 von Lord Rayleigh beschrieben. Er beschrieb die optischen Eigenschaften von periodischen mehrschichtigen Filmen, welche als vereinfachtes Modell eines eindimensionalen photonischen Kristalls verstanden werden k{\"o}nnen. Die Periodizit{\"a}t der Brechungsindex{\"a}nderung resultiert in einem optischen Filter f{\"u}r Frequenzen in einem bestimmten spektralen Bereich, weshalb dann dort keine Lichtausbreitung mehr m{\"o}glich ist. Wird dieses System aber durch eine Defektstelle in der Brechungsindexperiodizit{\"a}t gest{\"o}rt, sodass daraus zwei perfekt periodische Systeme entstehen, ist die Lichtausbreitung f{\"u}r eine bestimmte Frequenz dennoch m{\"o}glich. In der Folge resultiert daraus ein schmalbandiges Signal im Transmissionsspektrum. Die erlaubte Frequenz ist dabei u. a. abh{\"a}ngig vom Brechungsindexunterschied des periodischen Systems, d.h. Ver{\"a}nderung des Brechungsindexes einer Schicht f{\"u}hrt zu einer spektralen Verschiebung der erlaubten Frequenz, dadurch kann dieses Sensorkonzept f{\"u}r biochemische Sensorik ausgenutzt werden [1]. Diese Entwicklung des auf photonischen Kristallen basierenden Sensors war eine Kooperation mit dem Industriepartner „Nanoplus GmbH". In der Doktorarbeit wurden Simulationen und praktischen Arbeiten zur Designentwicklung des Sensors und die Arbeiten an einem ersten Modellaufbau f{\"u}r die biochemischen Anwendungen durchgef{\"u}hrt. F{\"u}r den faserbasierten Sensor wurden Faser-Bragg-Gitter in den Faserkern hineingeschrieben. Hill et al. entdeckten 1978, dass solche Gitterstrukturen genau wie photonische Kristalle als optische Filter fungieren [2]. Die Gitter bestehen dabei aus {\"A}nderungen des Brechungsindexes im Faserkern. Im Laufe der n{\"a}chsten vierzig Jahren wurden verschiedene Einschreibetechniken und Gitterstrukturen entwickelt, weshalb die Eigenschaften der jeweiligen Gitterstrukturen variieren. Eine solche Gitterstruktur sind u. a. die Faser-Bragg-Gitter, deren Gitterperiode, d. h. die Abst{\"a}nde der Brechungsindexmodifikationen, sich im Nanometer- bis Mikrometerbereich befinden. Aufgrund der kleinen Gitterperiode wird eine r{\"u}ckw{\"a}rtsf{\"u}hrende Welle im Kern f{\"u}r eine bestimmte Frequenz bzw. Wellenl{\"a}nge, der Bragg-Wellenl{\"a}nge, erzeugt. Im Endeffekt resultiert daraus ein schmalbandiges Signal sowohl im Transmissionsspektrum, als auch im Reflexionsspektrum. Die Resonanzwellenl{\"a}nge ist dabei proportional zu der Gitterperiode und dem effektiven Brechungsindex, welcher vom Brechungsindex des Kerns und des kernumgebenen Materials abh{\"a}ngig ist. Letztlich eignet sich diese Technik f{\"u}r physikochemische Sensorik. Im Rahmen dieser Arbeit wurden die Gitter mit Hilfe einer relativen neuen Herstellungsmethode in die Fasern geschrieben [3]. Anschließend stand die Entwicklung eines Biosensors im Vordergrund, wobei zun{\"a}chst ein Protokoll zum {\"A}tzen der Faser mit Flusss{\"a}ure entwickelt worden ist, dass das System sensitiv zum umgebenen Brechungsindex macht. Am Ende wurde ein Modellaufbau realisiert, indem ein Modellsystem, hier die Detektion vom C-reaktiven Protein mittels spezifischen einzelstr{\"a}ngigen DNS-Aptameren, erfolgreich getestet und quantifiziert worden ist. 1 Mandal, S.; Erickson, D. Nanoscale Optofluidic Sensor Arrays. Opt. Express 2008, 16 (3), 1623-1631. 2 Hill, K. O.; Fujii, Y.; Johnson, D. C.; Kawasaki, B. S. Photosensitivity in Optical Fiber Waveguides: Application to Reflection Filter Fabrication. Appl. Phys. Lett. 1978, 32 (10), 647-649. 3 Mart{\´i}nez, A.; Dubov, M.; Khrushchev, I.; Bennion, I. Direct Writing of Fibre Bragg Gratings by Femtosecond Laser. Electron. Lett. 2004, 40 (19), 1170.},
  language  = {de}
}
@phdthesis{Jaeger2018,
  author    = {Jaeger, David},
  title     = {Enabling Big Data security analytics for advanced network attack detection},
  doi       = {10.25932/publishup-43571},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435713},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XVII, 201, XXXIII},
  year      = {2018},
  abstract  = {The last years have shown an increasing sophistication of attacks against enterprises. Traditional security solutions like firewalls, anti-virus systems and generally Intrusion Detection Systems (IDSs) are no longer sufficient to protect an enterprise against these advanced attacks. One popular approach to tackle this issue is to collect and analyze events generated across the IT landscape of an enterprise. This task is achieved by the utilization of Security Information and Event Management (SIEM) systems. However, the majority of the currently existing SIEM solutions is not capable of handling the massive volume of data and the diversity of event representations. Even if these solutions can collect the data at a central place, they are neither able to extract all relevant information from the events nor correlate events across various sources. Hence, only rather simple attacks are detected, whereas complex attacks, consisting of multiple stages, remain undetected. Undoubtedly, security operators of large enterprises are faced with a typical Big Data problem. In this thesis, we propose and implement a prototypical SIEM system named Real-Time Event Analysis and Monitoring System (REAMS) that addresses the Big Data challenges of event data with common paradigms, such as data normalization, multi-threading, in-memory storage, and distributed processing. In particular, a mostly stream-based event processing workflow is proposed that collects, normalizes, persists and analyzes events in near real-time. In this regard, we have made various contributions in the SIEM context. First, we propose a high-performance normalization algorithm that is highly parallelized across threads and distributed across nodes. Second, we are persisting into an in-memory database for fast querying and correlation in the context of attack detection. Third, we propose various analysis layers, such as anomaly- and signature-based detection, that run on top of the normalized and correlated events. As a result, we demonstrate our capabilities to detect previously known as well as unknown attack patterns. Lastly, we have investigated the integration of cyber threat intelligence (CTI) into the analytical process, for instance, for correlating monitored user accounts with previously collected public identity leaks to identify possible compromised user accounts. In summary, we show that a SIEM system can indeed monitor a large enterprise environment with a massive load of incoming events. As a result, complex attacks spanning across the whole network can be uncovered and mitigated, which is an advancement in comparison to existing SIEM systems on the market.},
  language  = {en}
}
@phdthesis{SanchezGarcia2018,
  author    = {S{\´a}nchez Garc{\´i}a, Mar{\´i}a Clemencia},
  title     = {El parlache como elemento evocador de la oralidad ficcional en la novela Rosario Tijeras, de Jorge Franco},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-415297},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxi, 283},
  year      = {2018},
  abstract  = {El objetivo de este trabajo es investigar c{\´o}mo se evoca la realidad del habla en la novela Rosario Tijeras, del colombiano Jorge Franco, y sus traducciones al alem{\´a}n y al ingl{\´e}s. En esta novela negra, el autor recurre a un lenguaje coloquial llamado parlache, t{\´i}pico de un sector socioecon{\´o}mico marginal de Medell{\´i}n, y cuya influencia se ha extendido a todos los {\´a}mbitos de la ciudad y del pa{\´i}s. El estudio se centrar{\´a} en la descripci{\´o}n de la variaci{\´o}n diat{\´o}pica y diastr{\´a}tica en la ficci{\´o}n; concretamente, de las expresiones t{\´i}picas del parlache. Con ello se pretende determinar la contribuci{\´o}n de ciertos recursos ling{\"u}{\´i}sticos t{\´i}picos de esta variedad del espa{\~n}ol a la construcci{\´o}n de un di{\´a}logo hablado veros{\´i}mil. Adem{\´a}s, se estudiar{\´a} c{\´o}mo se reexpresa este «colorido local» en la evocaci{\´o}n de la oralidad en las traducciones. Se intentar{\´a}n determinar, por tanto, las divergencias de traducci{\´o}n y profundizar en la descripci{\´o}n de la variaci{\´o}n ling{\"u}{\´i}stica (diat{\´o}pica y diastr{\´a}tica) en la traducci{\´o}n literaria.},
  language  = {es}
}
@phdthesis{Fabian2018,
  author    = {Fabian, Jenny},
  title     = {Effects of algae on microbial carbon cycling in freshwaters},
  doi       = {10.25932/publishup-42222},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-422225},
  school      = {Universit{\"a}t Potsdam},
  pages     = {90},
  year      = {2018},
  abstract  = {Microbial processing of organic matter (OM) in the freshwater biosphere is a key component of global biogeochemical cycles. Freshwaters receive and process valuable amounts of leaf OM from their terrestrial landscape. These terrestrial subsidies provide an essential source of energy and nutrients to the aquatic environment as a function of heterotrophic processing by fungi and bacteria. Particularly in freshwaters with low in-situ primary production from algae (microalgae, cyanobacteria), microbial turnover of leaf OM significantly contributes to the productivity and functioning of freshwater ecosystems and not least their contribution to global carbon cycling. Based on differences in their chemical composition, it is believed that leaf OM is less bioavailable to microbial heterotrophs than OM photosynthetically produced by algae. Especially particulate leaf OM, consisting predominantly of structurally complex and aromatic polymers, is assumed highly resistant to enzymatic breakdown by microbial heterotrophs. However, recent research has demonstrated that OM produced by algae promotes the heterotrophic breakdown of leaf OM in aquatic ecosystems, with profound consequences for the metabolism of leaf carbon (C) within microbial food webs. In my thesis, I aimed at investigating the underlying mechanisms of this so called priming effect of algal OM on the use of leaf C in natural microbial communities, focusing on fungi and bacteria. The works of my thesis underline that algal OM provides highly bioavailable compounds to the microbial community that are quickly assimilated by bacteria (Paper II). The substrate composition of OM pools determines the proportion of fungi and bacteria within the microbial community (Paper I). Thereby, the fraction of algae OM in the aquatic OM pool stimulates the activity and hence contribution of bacterial communities to leaf C turnover by providing an essential energy and nutrient source for the assimilation of the structural complex leaf OM substrate. On the contrary, the assimilation of algal OM remains limited for fungal communities as a function of nutrient competition between fungi and bacteria (Paper I, II). In addition, results provide evidence that environmental conditions determine the strength of interactions between microalgae and heterotrophic bacteria during leaf OM decomposition (Paper I, III). However, the stimulatory effect of algal photoautotrophic activities on leaf C turnover remained significant even under highly dynamic environmental conditions, highlighting their functional role for ecosystem processes (Paper III). The results of my thesis provide insights into the mechanisms by which algae affect the microbial turnover of leaf C in freshwaters. This in turn contributes to a better understanding of the function of algae in freshwater biogeochemical cycles, especially with regard to their interaction with the heterotrophic community.},
  language  = {en}
}
@phdthesis{SaadHassanin2018,
  author    = {Saad Hassanin, Alshaimaa},
  title     = {Dynamic coronal mass ejection process and magnetic reconnection},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419626},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xix, 113},
  year      = {2018},
  abstract  = {The Sun is the nearest star to the Earth. It consists of an interior and an atmosphere. The convection zone is the outermost layer of the solar interior. A flux rope may emerge as a coherent structure from the convection zone into the solar atmosphere or be formed by magnetic reconnection in the atmosphere. A flux rope is a bundle of magnetic field lines twisting around an axis field line, creating a helical shape by which dense filament material can be supported against gravity. The flux rope is also considered as the key structure of the most energetic phenomena in the solar system, such as coronal mass ejections (CMEs) and flares. These magnetic flux ropes can produce severe geomagnetic storms. In particular, to improve the ability to forecast space weather, it is important to enrich our knowledge about the dynamic formation of flux ropes and the underlying physical mechanisms that initiate their eruption, such as a CME. A confined eruption consists of a filament eruption and usually an associated are, but does not evolve into a CME; rather, the moving plasma is halted in the solar corona and usually seen to fall back. The first detailed observations of a confined filament eruption were obtained on 2002 May 27by the TRACE satellite in the 195 A band. So, in the Chapter 3, we focus on a flux rope instability model. A twisted flux rope can become unstable by entering the kink instability regime. We show that the kink instability, which occurs if the twist of a flux rope exceeds a critical value, is capable of initiating of an eruption. This model is tested against the well observed confined eruption on 2002 May 27 in a parametric magnetohydrodynamic (MHD) simulation study that comprises all phases of the event. Very good agreement with the essential observed properties is obtained, only except for a relatively poor matching of the initial filament height. Therefore, in Chapter 4, we submerge the center point of the flux rope deeper below the photosphere to obtain a flatter coronal rope section and a better matching with the initial height profile of the erupting filament. This implies a more realistic inclusion of the photospheric line tying. All basic assumptions and the other parameter settings are kept the same as in Chapter 3. This complement of the parametric study shows that the flux rope instability model can yield an even better match with the observational data. We also focus in Chapters 3 and 4 on the magnetic reconnection during the confined eruption, demonstrating that it occurs in two distinct locations and phases that correspond to the observed brightenings and changes of topology, and consider the fate of the erupting flux, which can reform a (less twisted) flux rope. The Sun also produces series of homologous eruptions, i.e. eruptions which occur repetitively in the same active region and are of similar morphology. Therefore, in Chapter 5, we employ the reformed flux rope as a new initial condition, to investigate the possibility of subsequent homologous eruptions. Free magnetic energy is built up by imposing motions in the bottom boundary, such as converging motions, leading to flux cancellation. We apply converging motions in the sunspot area, such that a small part of the flux from the sunspots with different polarities is transported toward the polarity inversion line (PIL) and cancels with each other. The reconnection associated with the cancellation process forms more helical magnetic flux around the reformed flux rope, which leads to a second and a third eruption. In this study, we obtain the first MHD simulation results of a homologous sequence of eruptions that show a transition from a confined to two ejective eruptions, based on the reformation of a flux rope after each eruption.},
  language  = {en}
}
@phdthesis{Choi2018,
  author    = {Choi, Youngeun},
  title     = {DNA origami structures as versatile platforms for nanophotonics},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421483},
  school      = {Universit{\"a}t Potsdam},
  pages     = {125},
  year      = {2018},
  abstract  = {Nanophotonics is the field of science and engineering aimed at studying the light-matter interactions on the nanoscale. One of the key aspects in studying such optics at the nanoscale is the ability to assemble the material components in a spatially controlled manner. In this work, DNA origami nanostructures were used to self-assemble dye molecules and DNA coated plasmonic nanoparticles. Optical properties of dye nanoarrays, where the dyes were arranged at distances where they can interact by F{\"o}rster resonance energy transfer (FRET), were systematically studied according to the size and arrangement of the dyes using fluorescein (FAM) as the donor and cyanine 3 (Cy 3) as the acceptor. The optimized design, based on steady-state and time-resolved fluorometry, was utilized in developing a ratiometric pH sensor with pH-inert coumarin 343 (C343) as the donor and pH-sensitive FAM as the acceptor. This design was further applied in developing a ratiometric toxin sensor, where the donor C343 is unresponsive and FAM is responsive to thioacetamide (TAA) which is a well-known hepatotoxin. The results indicate that the sensitivity of the ratiometric sensor can be improved by simply arranging the dyes into a well-defined array. The ability to assemble multiple fluorophores without dye-dye aggregation also provides a strategy to amplify the signal measured from a fluorescent reporter, and was utilized here to develop a reporter for sensing oligonucleotides. By incorporating target capturing sequences and multiple fluorophores (ATTO 647N dye molecules), a reporter for microbead-based assay for non-amplified target oligonucleotide sensing was developed. Analysis of the assay using VideoScan, a fluorescence microscope-based technology capable of conducting multiplex analysis, showed the DNA origami nanostructure based reporter to have a lower limit of detection than a single stranded DNA reporter. Lastly, plasmonic nanostructures were assembled on DNA origami nanostructures as substrates to study interesting optical behaviors of molecules in the near-field. Specifically, DNA coated gold nanoparticles, silver nanoparticles, and gold nanorods, were placed on the DNA origami nanostructure aiming to study surface-enhanced fluorescence (SEF) and surface-enhanced Raman scattering (SERS) of molecules placed in the hotspot of coupled plasmonic structures.},
  language  = {en}
}
@phdthesis{Bazhenova2018,
  author    = {Bazhenova, Ekaterina},
  title     = {Discovery of Decision Models Complementary to Process Models},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-410020},
  school      = {Universit{\"a}t Potsdam},
  year      = {2018},
  abstract  = {Business process management is an acknowledged asset for running an organization in a productive and sustainable way. One of the most important aspects of business process management, occurring on a daily basis at all levels, is decision making. In recent years, a number of decision management frameworks have appeared in addition to existing business process management systems. More recently, Decision Model and Notation (DMN) was developed by the OMG consortium with the aim of complementing the widely used Business Process Model and Notation (BPMN). One of the reasons for the emergence of DMN is the increasing interest in the evolving paradigm known as the separation of concerns. This paradigm states that modeling decisions complementary to processes reduces process complexity by externalizing decision logic from process models and importing it into a dedicated decision model. Such an approach increases the agility of model design and execution. This provides organizations with the flexibility to adapt to the ever increasing rapid and dynamic changes in the business ecosystem. The research gap, identified by us, is that the separation of concerns, recommended by DMN, prescribes the externalization of the decision logic of process models in one or more separate decision models, but it does not specify this can be achieved. The goal of this thesis is to overcome the presented gap by developing a framework for discovering decision models in a semi-automated way from information about existing process decision making. Thus, in this thesis we develop methodologies to extract decision models from: (1) control flow and data of process models that exist in enterprises; and (2) from event logs recorded by enterprise information systems, encapsulating day-to-day operations. Furthermore, we provide an extension of the methodologies to discover decision models from event logs enriched with fuzziness, a tool dealing with partial knowledge of the process execution information. All the proposed techniques are implemented and evaluated in case studies using real-life and synthetic process models and event logs. The evaluation of these case studies shows that the proposed methodologies provide valid and accurate output decision models that can serve as blueprints for executing decisions complementary to process models. Thus, these methodologies have applicability in the real world and they can be used, for example, for compliance checks, among other uses, which could improve the organization's decision making and hence it's overall performance.},
  language  = {en}
}
@phdthesis{Antić2018,
  author    = {Antić, Andreas},
  title     = {Digitale {\"O}ffentlichkeiten und intelligente Kooperation},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-431-9},
  doi       = {10.25932/publishup-41096},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-410964},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ii, 454},
  year      = {2018},
  abstract  = {Um die gegenw{\"a}rtige Transformation der {\"O}ffentlichkeit im digitalen Zeitalter erfassen zu k{\"o}nnen, ist in der {\"O}ffentlichkeitstheorie eine erweiterte Perspektive notwendig, die nicht nur den massenmedialen Diskurs, sondern auch die Ver{\"a}nderung sozialer Praktiken und institutioneller Strukturen in den Blick nimmt. Das Ziel dieses Buches besteht darin, die Grundlagen einer solchen Perspektive auf die Theorie digitaler {\"O}ffentlichkeiten zu entwickeln. Im vorgeschlagenen Ansatz wird {\"O}ffentlichkeit im Anschluss an John Dewey als Prozess verstanden. In seiner prozessualen und funktionalen Bestimmung von {\"O}ffentlichkeit liegt eine besondere Originalit{\"a}t, die seinen Ansatz von anderen {\"O}ffentlichkeitskonzeptionen unterscheidet. Das Buch liefert sowohl eine systematische Rekonstruktion und Interpretation der Philosophie John Deweys als auch einen Vorschlag zur gesellschaftstheoretischen Deutung des digitalen Wandels.},
  language  = {de}
}
@phdthesis{vonNordheim2018,
  author    = {von Nordheim, Danny},
  title     = {Dielectric non-linearities of P(VDF-TrFE) single and multilayers for memory applications},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421778},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XVI, 109},
  year      = {2018},
  abstract  = {Poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) ferroelectric thin films of different molar ratio have been studied with regard to data memory applications. Therefore, films with thicknesses of 200 nm and less have been spin coated from solution. Observations gained from single layers have been extended to multilayer capacitors and three terminal transistor devices. Besides conventional hysteresis measurements, the measurement of dielectric non-linearities has been used as a main tool of characterisation. Being a very sensitive and non-destructive method, non-linearity measurements are well suited for polarisation readout and property studies. Samples have been excited using a high quality, single-frequency sinusoidal voltage with an amplitude significantly smaller than the coercive field of the samples. The response was then measured at the excitation frequency and its higher harmonics. Using the measurement results, the linear and non-linear dielectric permittivities ɛ₁, ɛ₂ and ɛ₃ have been determined. The permittivities have been used to derive the temperature-dependent polarisation behaviour as well as the polarisation state and the order of the phase transitions. The coercive field in VDF-TrFE copolymers is high if compared to their ceramic competitors. Therefore, the film thickness had to be reduced significantly. Considering a switching voltage of 5 V and a coercive field of 50 MV/m, the film thickness has to be 100 nm and below. If the thickness becomes substantially smaller than the other dimensions, surface and interface layer effects become more pronounced. For thicker films of P(VDF-TrFE) with a molar fraction of 56/44 a second-order phase transition without a thermal hysteresis for an ɛ₁(T) temperature cycle has been predicted and observed. This however, could not be confirmed by the measurements of thinner films. A shift of transition temperatures as well as a temperature independent, non-switchable polarisation and a thermal hysteresis for P(VDF-TrFE) 56/44 have been observed. The impact of static electric fields on the polarisation and the phase transition has therefore been studied and simulated, showing that all aforementioned phenomena including a linear temperature dependence of the polarisation might originate from intrinsic electric fields. In further experiments the knowledge gained from single layer capacitors has been extended to bilayer copolymer thin films of different molar composition. Bilayers have been deposited by succeeding cycles of spin coating from solution. Single layers and their bilayer combination have been studied individually in order to prove the layers stability. The individual layers have been found to be physically stable. But while the bilayers reproduced the main ɛ₁(T) properties of the single layers qualitatively, quantitative numbers could not be explained by a simple serial connection of capacitors. Furthermore, a linear behaviour of the polarisation throughout the measured temperature range has been observed. This was found to match the behaviour predicted considering a constant electric field. Retention time is an important quantity for memory applications. Hence, the retention behaviour of VDF-TrFE copolymer thin films has been determined using dielectric non-linearities. The polarisation loss in P(VDF-TrFE) poled samples has been found to be less than 20\% if recorded over several days. The loss increases significantly if the samples have been poled with lower amplitudes, causing an unsaturated polarisation. The main loss was attributed to injected charges. Additionally, measurements of dielectric non-linearities have been proven to be a sensitive and non-destructive tool to measure the retention behaviour. Finally, a ferroelectric field effect transistor using mainly organic materials (FerrOFET) has been successfully studied. DiNaphtho[2,3-b:2',3'-f]Thieno[3,2-b]Thiophene (DNTT) has proven to be a stable, suitable organic semiconductor to build up ferroelectric memory devices. Furthermore, an oxidised aluminium bottom electrode and additional dielectric layers, i.e. parylene C, have proven to reduce the leakage current and therefore enhance the performance significantly.},
  language  = {en}
}
@phdthesis{SchulteUmberg2018,
  author    = {Schulte-Umberg, Ulf},
  title     = {Die langobardischen Hofkirchen in Capua},
  doi       = {10.25932/publishup-48109},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-481099},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VII, 427},
  year      = {2018},
  abstract  = {Im historischen Zentrum der mittelalterlichen Stadt Capua hat sich mit den drei Kirchen S. Salvatore „Maggiore" a Corte, S. Giovanni a Corte und S. Michele a Corte eine Gruppe von Sakralbauten erhalten, die nicht nur durch ihre {\"u}bereinstimmende namentliche Attribution einen Zusammenhang mit dem langobardischen F{\"u}rstenhof der Stadt offenbaren, sondern auch durch die r{\"a}umliche Disposition im urbanistischen Gef{\"u}ge. Im vorliegenden Buch wird die {\"u}berkommene Bausubstanz einer grundlegenden Analyse unterzogen, um herauszuarbeiten, welche Bestandteile den {\"a}ltesten Bauphasen zuzuordnen sind und somit als langobardenzeitlich angesprochen werden k{\"o}nnen. Eine ausf{\"u}hrliche Untersuchung der zugeh{\"o}rigen Bauplastik erg{\"a}nzt gleichwertig diesen ersten Teil. Die Kontextualisierung der Ergebnisse hilft dabei, ein Bild von der Kunst und Architektur des in S{\"u}ditalien an Monumenten eher armen 10. Jahrhunderts zu generieren und erlaubt R{\"u}ckschl{\"u}sse auf den geistigen Hintergrund, vor dem die drei Hofkirchen entstanden sind.},
  language  = {de}
}
@phdthesis{Kirchner2018,
  author    = {Kirchner, Moritz},
  title     = {Der neueste Geist des Kapitalismus},
  doi       = {10.25932/publishup-41498},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414985},
  school      = {Universit{\"a}t Potsdam},
  pages     = {520},
  year      = {2018},
  abstract  = {Der neueste Geist des Kapitalismus beschreibt das heutige Mobilisierungs- und Rechtfertigungsregime, welches uns immer wieder dazu bringt, unsere Arbeitskraft zu verwerten und uns t{\"a}glich ins kapitalistische Hamsterrad zu begeben. Der alte Geist des Kapitalismus, nach dem Fleiß, Disziplin und Sparsamkeit zum gesellschaftlichen Aufstieg f{\"u}hren, tr{\"a}gt l{\"a}ngst nicht mehr. Auch reine Selbstverwirklichung, der Anspruch auf Flexibilit{\"a}t und flache Hierarchien reicht nicht mehr aus, um insbesondere gut qualifizierte Menschen zur Arbeit zu motivieren. Der neueste Geist des Kapitalismus hingegen ist das Produkt der tiefen Subjektivierung und Verinnerlichung des Neoliberalismus. Es geht um best{\"a}ndige berufliche und private Optimierung sowie ein umfassendes Nutzendenken. Gl{\"u}cklich zu sein, ist nicht mehr nur eine Option, sondern es gibt den normativen Anspruch, gl{\"u}cklich sein zu sollen. Das Leistungsprinzip wird aktiv bejaht und Leistungsgerechtigkeit eingefordert. Die Bew{\"a}ltigung von Komplexit{\"a}t wird zum Metathema. Der Anspruch auf Distinktion, insbesondere auch gegen{\"u}ber „Minderleisten" nimmt zu. Die Welt wird zunehmend durch die Brille von Zahlen und Statistiken betrachtet, und Key Performance Indicators werden zu st{\"a}ndigen Wegbegleitern. Das Leben wird, verst{\"a}rkt durch die sozialen Netzwerke, zunehmend zu einer performativen B{\"u}hne, die zugleich dem Networking dient. In der Konsequenz der best{\"a}ndigen Optimierung wird es jedoch immer schwerer, zur Ruhe zu kommen. Dieser neueste Geist des Kapitalismus, dieser umfassende Optimierungsanspruch, hat jedoch gravierende Konsequenzen. Zu den manifesten Pathologien des neuesten Geistes geh{\"o}ren gestiegene Raten von Depressionen, Burn-out und Angstst{\"o}rungen. Gesellschaftlich spreizt sich die soziale Schere immer mehr anhand der F{\"a}higkeit, Komplexit{\"a}t bew{\"a}ltigen zu k{\"o}nnen, was viele Verlierer und prek{\"a}re Gewinner produziert. Daher wird dieser neueste Geist des Kapitalismus sozialkritisch, k{\"u}nstlerkritisch und ideologiekritisch hinterfragt. Die Rolle der Gewerkschaften als der Zentralinstitution der Sozialkritik, die ein tats{\"a}chliches Gegengewicht zum neuesten Geist des Kapitalismus bieten kann, wird kontrovers diskutiert. Und es wird aufgezeigt: chillen ist die neue Subversion.},
  language  = {de}
}
@phdthesis{Fliesser2018,
  author    = {Fließer, Michael},
  title     = {Der Einfluss unterschiedlicher Indikatoren des sozio{\"o}konomischen Status auf R{\"u}ckenschmerz},
  doi       = {10.25932/publishup-42345},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-423455},
  school      = {Universit{\"a}t Potsdam},
  pages     = {84},
  year      = {2018},
  abstract  = {Obwohl der sozio{\"o}konomische Status (SES) eine in der Sozialepidemiologie h{\"a}ufig gebrauchte Variable darstellt, ist seine Verwendung mit methodischen Problemen verkn{\"u}pft: Seine latente Struktur f{\"u}hrt dazu, dass sich verschiedene M{\"o}glichkeiten der Operationalisierung er{\"o}ffnen. Diese reichen von klassischen Ungleichheitsindikatoren wie Bildung, Einkommen oder Berufsposition, {\"u}ber multidimensionale oder {\"u}ber Nachbarschaftsmerkmale konstruierte Indizes, bis hin zu subjektiven Statuseinsch{\"a}tzungen. Problematisch ist dies insofern, als verschiedene Indikatoren auf unterschiedlichen theoretischen Konstrukten beruhen und unterschiedliche Schlussfolgerungen erlauben. In dieser Arbeit wird deshalb in einem ersten Schritt anhand eines systematischen Reviews zum Zusammenhang von SES und R{\"u}ckenschmerzen {\"u}berpr{\"u}ft, welche Indikatoren in wissenschaftlichen Publikationen eingesetzt werden und wie die Auswahl begr{\"u}ndet wird. Das Ergebnis zeigt eine klare Pr{\"a}ferenz f{\"u}r klassische Indikatoren (Bildung, Einkommen und Berufsposition). Erl{\"a}utert wurde die jeweilige Auswahl allerdings nur in einem geringen Prozentsatz der untersuchten Artikel, obwohl die unterschiedlichen Studienergebnisse nahelegen, dass der gew{\"a}hlte Indikator einen Einfluss auf den gefundenen Zusammenhang aus{\"u}ben k{\"o}nnte. Deshalb wurde in einem weiteren Schritt {\"u}berpr{\"u}ft, wie unterschiedliche SES-Indikatoren mit der Verbesserung von R{\"u}ckenschmerzen nach einer Rehabilitation (Studie 1) und der Neuentstehung von R{\"u}ckenschmerzen (Studie 2) zusammenh{\"a}ngen. Außerdem wurde untersucht, ob ein einfaches Modell den Zusammenhang von SES und Gesundheit so darstellen kann, dass a priori abzusch{\"a}tzen ist, wie hoch der Einfluss unterschiedlicher Indikatoren auf einen bestimmten Gesundheitsoutput sein k{\"o}nnte. Es zeigt sich, dass sich der errechnete Zusammenhang zwischen den verschiedenen Indikatoren und chronischen R{\"u}ckenschmerzen erheblich unterscheidet: F{\"u}r Menschen, die bereits wegen R{\"u}ckenschmerzen in Rehabilitation waren, erwiesen sich Bildung und Berufsposition als {\"a}hnlich einflussreiche Einflussfaktoren, w{\"a}hrend f{\"u}r das Einkommen kein bedeutender Zusammenhang festgestellt werden konnte. F{\"u}r die Neuentstehung chronischer R{\"u}ckenschmerzen zeigte sich die Berufsposition als wichtigster Indikator, gefolgt von Bildung, w{\"a}hrend f{\"u}r Einkommen kein signifikanter Zusammenhang gefunden werden konnte. Folglich bestimmt die Wahl des Indikators die H{\"o}he des festgestellten Zusammenhangs stark mit. Unterschiedliche Indikatoren d{\"u}rfen deshalb nicht als austauschbar betrachtet werden und es muss bei jeder Forschungsfrage genau {\"u}berlegt werden, welcher Indikator f{\"u}r die jeweilige Fragestellung am besten verwendet werden kann. Das vorgeschlagene theoretische Modell kann dabei als Unterst{\"u}tzung dienen.},
  language  = {de}
}
@phdthesis{Holl2018,
  author    = {Holl, Anna Katharina},
  title     = {Deficits in theory of mind and executive function as risk factors for conduct problems from middle childhood to early adolescence - a longitudinal perspective},
  doi       = {10.25932/publishup-45991},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-459915},
  school      = {Universit{\"a}t Potsdam},
  pages     = {292},
  year      = {2018},
  abstract  = {In this thesis, deficits in theory of mind (ToM) and executive function (EF) were examined in tandem and separately as risk factors for conduct problems, including different forms and functions of aggressive behavior. All three reported studies and the additional analyses were based on a large community sample of N = 1,657 children, including three waves of a longitudinal study covering middle childhood and the transition to early adolescence (range 6 to 13 years) over a total of about three years. All data were analyzed with structural equation modeling. Altogether, the results of all the conducted studies in this thesis extend previous research and confirm the propositions of the SIP model (Crick \& Dodge, 1994) and of the amygdala theory of violent behavior (e.g., Blair et al., 2014) besides other accounts. Considering the three main research questions, the results of the thesis suggest first that deficits in ToM are a risk factor for relational and physical aggression from a mean age of 8 to 11 years under the control of stable between-person differences in aggression. In addition, earlier relationally aggressive behavior predicts later deficits in ToM in this age range, which confirms transactional relations between deficits in ToM and aggressive behavior in children (Crick \& Dodge, 1994). Further, deficits in ToM seem to be a risk factor for parent-rated conduct problems cross-sectionally in an age range from 9 to 13 years. Second, deficits in cool EF are a risk factor for later physical, relational, and reactive aggression but not for proactive aggression over a course of three years from middle childhood to early adolescence. Habitual anger seems to mediate the relation between cool EF and physical, and as a trend also relational, aggression. Deficits in emotional and inhibitory control and planning have a direct effect on the individual level of conduct problems under the control of interindividual differences in conduct problems at a mean age of 8 years, but not on the trajectory of conduct problems over the course from age 8 to 11. Third, when deficits in cool EF and ToM are studied in tandem cross-sectionally at the transition from middle childhood to early adolescence, deficits in cool EF seem to play only an indirect role through deficits in ToM as a risk factor for conduct problems. Finally, all results hold equal for females and males in the conducted studies. The results of this thesis emphasize the need to intervene in the transactional processes between deficits in ToM and in EF and conduct problems, including different forms and functions of aggression, particularly in the socially sensible period from middle and late childhood to early adolescence.},
  language  = {en}
}
@phdthesis{Smith2018,
  author    = {Smith, Taylor},
  title     = {Decadal changes in the snow regime of High Mountain Asia, 1987-2016},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-407120},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xiii, 142},
  year      = {2018},
  abstract  = {More than a billion people rely on water from rivers sourced in High Mountain Asia (HMA), a significant portion of which is derived from snow and glacier melt. Rural communities are heavily dependent on the consistency of runoff, and are highly vulnerable to shifts in their local environment brought on by climate change. Despite this dependence, the impacts of climate change in HMA remain poorly constrained due to poor process understanding, complex terrain, and insufficiently dense in-situ measurements. HMA's glaciers contain more frozen water than any region outside of the poles. Their extensive retreat is a highly visible and much studied marker of regional and global climate change. However, in many catchments, snow and snowmelt represent a much larger fraction of the yearly water budget than glacial meltwaters. Despite their importance, climate-related changes in HMA's snow resources have not been well studied. Changes in the volume and distribution of snowpack have complex and extensive impacts on both local and global climates. Eurasian snow cover has been shown to impact the strength and direction of the Indian Summer Monsoon -- which is responsible for much of the precipitation over the Indian Subcontinent -- by modulating earth-surface heating. Shifts in the timing of snowmelt have been shown to limit the productivity of major rangelands, reduce streamflow, modify sediment transport, and impact the spread of vector-borne diseases. However, a large-scale regional study of climate impacts on snow resources had yet to be undertaken. Passive Microwave (PM) remote sensing is a well-established empirical method of studying snow resources over large areas. Since 1987, there have been consistent daily global PM measurements which can be used to derive an estimate of snow depth, and hence snow-water equivalent (SWE) -- the amount of water stored in snowpack. The SWE estimation algorithms were originally developed for flat and even terrain -- such as the Russian and Canadian Arctic -- and have rarely been used in complex terrain such as HMA. This dissertation first examines factors present in HMA that could impact the reliability of SWE estimates. Forest cover, absolute snow depth, long-term average wind speeds, and hillslope angle were found to be the strongest controls on SWE measurement reliability. While forest density and snow depth are factors accounted for in modern SWE retrieval algorithms, wind speed and hillslope angle are not. Despite uncertainty in absolute SWE measurements and differences in the magnitude of SWE retrievals between sensors, single-instrument SWE time series were found to be internally consistent and suitable for trend analysis. Building on this finding, this dissertation tracks changes in SWE across HMA using a statistical decomposition technique. An aggregate decrease in SWE was found (10.6 mm/yr), despite large spatial and seasonal heterogeneities. Winter SWE increased in almost half of HMA, despite general negative trends throughout the rest of the year. The elevation distribution of these negative trends indicates that while changes in SWE have likely impacted glaciers in the region, climate change impacts on these two pieces of the cryosphere are somewhat distinct. Following the discussion of relative changes in SWE, this dissertation explores changes in the timing of the snowmelt season in HMA using a newly developed algorithm. The algorithm is shown to accurately track the onset and end of the snowmelt season (70\% within 5 days of a control dataset, 89\% within 10). Using a 29-year time series, changes in the onset, end, and duration of snowmelt are examined. While nearly the entirety of HMA has experienced an earlier end to the snowmelt season, large regions of HMA have seen a later start to the snowmelt season. Snowmelt periods have also decreased in almost all of HMA, indicating that the snowmelt season is generally shortening and ending earlier across HMA. By examining shifts in both the spatio-temporal distribution of SWE and the timing of the snowmelt season across HMA, we provide a detailed accounting of changes in HMA's snow resources. The overall trend in HMA is towards less SWE storage and a shorter snowmelt season. However, long-term and regional trends conceal distinct seasonal, temporal, and spatial heterogeneity, indicating that changes in snow resources are strongly controlled by local climate and topography, and that inter-annual variability plays a significant role in HMA's snow regime.},
  language  = {en}
}
@phdthesis{Schwahn2018,
  author    = {Schwahn, Kevin},
  title     = {Data driven approaches to infer the regulatory mechanism shaping and constraining levels of metabolites in metabolic networks},
  doi       = {10.25932/publishup-42324},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-423240},
  school      = {Universit{\"a}t Potsdam},
  pages     = {109},
  year      = {2018},
  abstract  = {Systems biology aims at investigating biological systems in its entirety by gathering and analyzing large-scale data sets about the underlying components. Computational systems biology approaches use these large-scale data sets to create models at different scales and cellular levels. In addition, it is concerned with generating and testing hypotheses about biological processes. However, such approaches are inevitably leading to computational challenges due to the high dimensionality of the data and the differences in the dimension of data from different cellular layers. This thesis focuses on the investigation and development of computational approaches to analyze metabolite profiles in the context of cellular networks. This leads to determining what aspects of the network functionality are reflected in the metabolite levels. With these methods at hand, this thesis aims to answer three questions: (1) how observability of biological systems is manifested in metabolite profiles and if it can be used for phenotypical comparisons; (2) how to identify couplings of reaction rates from metabolic profiles alone; and (3) which regulatory mechanism that affect metabolite levels can be distinguished by integrating transcriptomics and metabolomics read-outs. I showed that sensor metabolites, identified by an approach from observability theory, are more correlated to each other than non-sensors. The greater correlations between sensor metabolites were detected both with publicly available metabolite profiles and synthetic data simulated from a medium-scale kinetic model. I demonstrated through robustness analysis that correlation was due to the position of the sensor metabolites in the network and persisted irrespectively of the experimental conditions. Sensor metabolites are therefore potential candidates for phenotypical comparisons between conditions through targeted metabolic analysis. Furthermore, I demonstrated that the coupling of metabolic reaction rates can be investigated from a purely data-driven perspective, assuming that metabolic reactions can be described by mass action kinetics. Employing metabolite profiles from domesticated and wild wheat and tomato species, I showed that the process of domestication is associated with a loss of regulatory control on the level of reaction rate coupling. I also found that the same metabolic pathways in Arabidopsis thaliana and Escherichia coli exhibit differences in the number of reaction rate couplings. I designed a novel method for the identification and categorization of transcriptional effects on metabolism by combining data on gene expression and metabolite levels. The approach determines the partial correlation of metabolites with control by the principal components of the transcript levels. The principle components contain the majority of the transcriptomic information allowing to partial out the effect of the transcriptional layer from the metabolite profiles. Depending whether the correlation between metabolites persists upon controlling for the effect of the transcriptional layer, the approach allows us to group metabolite pairs into being associated due to post-transcriptional or transcriptional regulation, respectively. I showed that the classification of metabolite pairs into those that are associated due to transcriptional or post-transcriptional regulation are in agreement with existing literature and findings from a Bayesian inference approach. The approaches developed, implemented, and investigated in this thesis open novel ways to jointly study metabolomics and transcriptomics data as well as to place metabolic profiles in the network context. The results from these approaches have the potential to provide further insights into the regulatory machinery in a biological system.},
  language  = {en}
}
@phdthesis{Luehe2018,
  author    = {L{\"u}he, Josefine},
  title     = {Das Zusammenspiel von Geschlecht und sozialer Herkunft im Bildungserfolg und in den beruflichen Aspirationen},
  doi       = {10.25932/publishup-42887},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-428870},
  school      = {Universit{\"a}t Potsdam},
  pages     = {198},
  year      = {2018},
  abstract  = {Studien zum Bildungserfolg in Deutschland weisen auf verschiedene Ungleichheitsdimensionen hin. So wurde wiederholt ein enger Zusammenhang zwischen der sozialen Herkunft und dem schulischen Bildungserfolg dokumentiert. Des Weiteren stellen auch Geschlechterunterschiede im Bildungserfolg einen vielfach berichteten und sowohl wissenschaftlich als auch gesellschaftlich diskutierten Befund dar. Der großen Anzahl an Studien, die sich jeweils einer dieser Ungleichheitsdimensionen widmen, steht jedoch ein Forschungsbedarf bez{\"u}glich des systematischen Wissens {\"u}ber die Wechselwirkung von Geschlecht und sozialer Herkunft im Bildungserfolg gegen{\"u}ber. Vor diesem Hintergrund hat die vorliegende Arbeit zum Ziel, das Zusammenspiel von Geschlecht und sozialer Herkunft zu untersuchen, wobei sie von zwei {\"u}bergeordneten Fragestellungen geleitet wird, die im Rahmen von vier Teilstudien untersucht werden.Erstens wurde das Zusammenspiel von Geschlecht und sozio{\"o}konomischem Status (SES) in unterschiedlichen Facetten des Bildungserfolges sowie in den Berufsaspirationen analysiert (Teilstudien 1-3). Zweitens wurde untersucht, inwiefern die elterlichen Geschlechterrollenvorstellungen mit den Schulleistungen ihres Kindes assoziiert sind. Vor diesem Hintergrund wurde ebenso der Zusammenhang zwischen den elterlichen Geschlechterrollenvorstellungen und Merkmalen des famili{\"a}ren Hintergrundes analysiert (Teilstudie 4). Zusammenfassend betrachtet weisen die Ergebnisse der Teilstudien auf eine Wechselwirkung von Geschlechtszugeh{\"o}rigkeit und sozialer Herkunft im Bildungserfolg sowie in den beruflichen Aspirationen hin, auch wenn die entsprechenden Effekte eher klein ausfallen. Entgegen der gesellschaftlichen Konnotation von Mathematik als „Jungenfach" stellen die Befunde damit beispielsweise einen Hinweis darauf dar, dass die vielfach zitierten Geschlechterunterschiede in den mathematischen Kompetenzen nicht als „naturgegeben" sondern beeinflussbar verstanden werden k{\"o}nnen. Damit untermauern die Ergebnisse die unter anderem im Rahmen verschiedener Theorien herausgestellte Bedeutsamkeit des Sozialisationskontextes f{\"u}r die Entwicklung der F{\"a}higkeiten und Ziele von Jungen und M{\"a}dchen sowie die im internationalen Vergleich gezeigte Variabilit{\"a}t von Geschlechterunterschieden in Schulleistungen.},
  language  = {de}
}
@phdthesis{Hein2018,
  author    = {Hein, Friederike},
  title     = {Das Recht auf Familiennachzug im Ausl{\"a}nderrecht},
  doi       = {10.25932/publishup-43264},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-432642},
  school      = {Universit{\"a}t Potsdam},
  pages     = {170},
  year      = {2018},
  abstract  = {Die Arbeit besch{\"a}ftigt sich mit den aktuellen Regelungen des deutschen Aufenthaltsrechts in Bezug auf die M{\"o}glichkeiten des Familiennachzuges. Es werden Schwachstellen der aktuellen Regelungen aufgezeigt, Ursachen, Rechtfertigungsgr{\"u}nde und m{\"o}gliche L{\"o}sungsans{\"a}tze betrachtet. Schwerpunkt der Betrachtung sind die Konflikte, welche sich unter dem Begriff der Inl{\"a}nderdiskriminierung zusammenfassen lassen. Hierzu wird das Ph{\"a}nomen der Inl{\"a}nderdiskriminierung untersucht und die im Kontext des Familiennachzuges hierzu ergangene Rechtsprechung des EuGH betrachtet. Dabei gilt das Hauptaugenmerk der Figur des grenz{\"u}berschreitenden Bezuges, welche der EuGH im Ergebnis mittlerweile aufgel{\"o}st hat. Als Ergebnis dieses Abschnittes der Arbeit wird festgestellt, dass eine Unterscheidung von Nachzug zu Deutschen oder zu Unionsb{\"u}rgern gegen Gleichheitss{\"a}tze verst{\"o}ßt und aufzuheben ist. Weiterhin betrachtet die Arbeit verschiedene alternative Lebensmodelle neben der klassischen verschiedengeschlechtlichen Ehe. In Bezug auf gleichgeschlechtliche Lebensgemeinschaften werden auch nach Einf{\"u}hrung der „Ehe f{\"u}r alle" weitere Schwachstellen verortet, die vor allem darauf fußen, dass Nachzugsrechte vom Bestehen eines Instituts abh{\"a}ngen, welches in großen Teilen der Welt nicht gibt. In Hinblick auf nichtehelichen Lebensgemeinschaften wird hingegen die geltende Rechtslage als ausreichend betrachtet. Zuletzt betrachtet die Arbeit Ehemodelle, welche im deutschen Recht nicht vorgesehen und anerkannt sind. Dies sind die Zwangs-, Kinder- und Mehrehe. Es wird beleuchtet, wie das deutsche Recht und insbesondere das Aufenthaltsrecht mit diesen Ehen umgeht und welcher Zweck mit den bestehenden Regelungen verfolgt wird. W{\"a}hrend der Gesetzgeber den Schutz der Opfer solcher Eheschließungen vor Augen hatte, kommt die Untersuchung zu dem Ergebnis, dass vielmehr eine weitere Gef{\"a}hrdung eintritt, welche nur zu vermeiden w{\"a}re, wenn auch diese Ehemodelle zun{\"a}chst anerkannt w{\"u}rden und den Opfern im Inland sodann Hilfe angeboten w{\"u}rde. Insgesamt stellt die Arbeit gravierende M{\"a}ngel in menschenrechtlicher Hinsicht im bestehenden Recht des Familiennachzugs fest und schl{\"a}gt eine generelle Neuordnung vor. Die betrachteten Regelungen entsprechen dem Regelungsstand im Juli 2018.},
  language  = {de}
}
@phdthesis{Mielke2018,
  author    = {Mielke, Jahel},
  title     = {Coordination on Green Investment},
  doi       = {10.25932/publishup-42745},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427459},
  school      = {Universit{\"a}t Potsdam},
  pages     = {viii, 209},
  year      = {2018},
  abstract  = {To reach its climate targets, the European Union has to implement a major sustainability transition in the coming decades. While the socio-technical change required for this transition is well discussed in the academic literature, the economics that go along with it are often reduced to a cost-benefit perspective of climate policy measures. By investigating climate change mitigation as a coordination problem, this thesis offers a novel perspective: It integrates the economic and the socio-technical dimension and thus allows to better understand the opportunities of a sustainability transition in Europe. First, a game theoretic framework is developed to illustrate coordination on green or brown investment from an agent perspective. A model based on the coordination game "stag hunt" is used to discuss the influence of narratives and signals for green investment as a means to coordinate expectations towards green growth. Public and private green investment impulses - triggered by credible climate policy measures and targets - serve as an example for a green growth perspective for Europe in line with a sustainability transition. This perspective also embodies a critical view on classical analyses of climate policy measures. Secondly, this analysis is enriched with empirical results derived from stakeholder involvement. In interviews and with a survey among European insurance companies, coordination mechanisms such as market and policy signals are identified and evaluated by their impact on investment strategies for green infrastructure. The latter, here defined as renewable energy, electricity distribution and transmission as well as energy efficiency improvements, is considered a central element of the transition to a low-carbon society. Thirdly, this thesis identifies and analyzes major criticisms raised towards stakeholder involvement in sustainability science. On a conceptual level, different ways of conducting such qualitative research are classified. This conceptualization is then evaluated by scientists, thereby generating empirical evidence on ideals and practices of stakeholder involvement in sustainability science. Through the combination of theoretical and empirical research on coordination problems, this thesis offers several contributions: On the one hand, it outlines an approach that allows to assess the economic opportunities of sustainability transitions. This is helpful for policy makers in Europe that are striving to implement climate policy measures addressing the targets of the Paris Agreement as well as to encourage a shift of investments towards green infrastructure. On the other hand, this thesis enhances the stabilization of the theoretical foundations in sustainability science. Therefore, it can aid researchers who involve stakeholders when studying sustainability transitions.},
  language  = {en}
}
@phdthesis{Cheng2018,
  author    = {Cheng, Xiao},
  title     = {Controlled solvent vapor annealing of block copolymer films},
  doi       = {10.25932/publishup-42417},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-424179},
  school      = {Universit{\"a}t Potsdam},
  pages     = {X, 166},
  year      = {2018},
  abstract  = {This project was focused on exploring the phase behavior of poly(styrene)187000-block-poly(2-vinylpyridine)203000 (SV390) with high molecular weight (390 kg/mol) in thin films, in which the self-assembly of block copolymers (BCPs) was realized via thermo-solvent annealing. The advanced processing technique of solvent vapor treatment provides controlled and stable conditions. In Chapter 3, the factors to influence the annealing process and the swelling behavior of homopolymers are presented and discussed. The swelling behavior of BCP in films is controlled by the temperature of the vapor and of the substrate, on one hand, and variation of the saturation of the solvent vapor atmosphere (different solvents), on the other hand. Additional factors like the geometry and material of the chamber, the type of flow inside the chamber etc. also influence the reproducibility and stability of the processing. The slightly selective solvent vapor of chloroform gives 10\% more swelling of P2VP than PS in films with thickness of ~40 nm. The tunable morphology in ultrathin films of high molecular weight BCP (SV390) was investigated in Chapter 4. First, the swelling behavior can be precisely tuned by temperature and/or vapor flow separately, which provided information for exploring the multiple-parameter-influenced segmental chain mobility of polymer films. The equilibrium state of SV390 in thin films influenced by temperature was realized at various temperatures with the same degree of swelling. Various methods including characterization with SFM, metallization and RIE were used to identify the morphology of films as porous half-layer with PS dots and P2VP matrix. The kinetic investigations demonstrate that on substrates with either weak or strong interaction the original morphology of the BCP with high molecular weight is changed very fast within 5 min, and the further annealing serves for annihilation of defects. The morphological development of symmetric BCP in films with thickness increasing from half-layer to one-layer influenced by confinement factors of gradient film thicknesses and various surface properties of substrates was studied in Chapter 5. SV390 and SV99 films show bulk lamella-forming morphology after slightly selective solvent vapor (chloroform) treatment. SV99 films show cylinder-forming morphology under strongly selective solvent vapor (toluene) treatment since the asymmetric structure (caused by toluene uptake in PS blocks only) of SV99 block copolymer during annealing. Both kinds of morphology (lamella and cylinder) are influenced by the film thickness. The annealed morphology of SV390 and SV99 influenced by the combination of confined film and substrate property is similar to the morphology on flat silicon wafers. In this chapter the gradients in the film thickness and surface properties of the substrates with regard to their influence on the morphological development in thin BCP films are presented. Directed self-assembly (graphoepitaxy) of this SV390 was also investigated to compare with systematically reported SV99. In Chapter 6 an approach to induced oriented microphase separation in thick block copolymer films via treatment with the oriented vapor flow using mini-extruder is envisaged to be an alternative to existing methodologies, e.g. via non-solvent-induced phase separation. The preliminary tests performed in this study confirm potential perspective of this method, which alters the structure through the bulk of the film (as revealed by SAXS measurements), but more detailed studies have to be conducted in order to optimize the preparation.},
  language  = {en}
}
@phdthesis{Richter2018,
  author    = {Richter, Rico},
  title     = {Concepts and techniques for processing and rendering of massive 3D point clouds},
  doi       = {10.25932/publishup-42330},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-423304},
  school      = {Universit{\"a}t Potsdam},
  pages     = {v, 131},
  year      = {2018},
  abstract  = {Remote sensing technology, such as airborne, mobile, or terrestrial laser scanning, and photogrammetric techniques, are fundamental approaches for efficient, automatic creation of digital representations of spatial environments. For example, they allow us to generate 3D point clouds of landscapes, cities, infrastructure networks, and sites. As essential and universal category of geodata, 3D point clouds are used and processed by a growing number of applications, services, and systems such as in the domains of urban planning, landscape architecture, environmental monitoring, disaster management, virtual geographic environments as well as for spatial analysis and simulation. While the acquisition processes for 3D point clouds become more and more reliable and widely-used, applications and systems are faced with more and more 3D point cloud data. In addition, 3D point clouds, by their very nature, are raw data, i.e., they do not contain any structural or semantics information. Many processing strategies common to GIS such as deriving polygon-based 3D models generally do not scale for billions of points. GIS typically reduce data density and precision of 3D point clouds to cope with the sheer amount of data, but that results in a significant loss of valuable information at the same time. This thesis proposes concepts and techniques designed to efficiently store and process massive 3D point clouds. To this end, object-class segmentation approaches are presented to attribute semantics to 3D point clouds, used, for example, to identify building, vegetation, and ground structures and, thus, to enable processing, analyzing, and visualizing 3D point clouds in a more effective and efficient way. Similarly, change detection and updating strategies for 3D point clouds are introduced that allow for reducing storage requirements and incrementally updating 3D point cloud databases. In addition, this thesis presents out-of-core, real-time rendering techniques used to interactively explore 3D point clouds and related analysis results. All techniques have been implemented based on specialized spatial data structures, out-of-core algorithms, and GPU-based processing schemas to cope with massive 3D point clouds having billions of points. All proposed techniques have been evaluated and demonstrated their applicability to the field of geospatial applications and systems, in particular for tasks such as classification, processing, and visualization. Case studies for 3D point clouds of entire cities with up to 80 billion points show that the presented approaches open up new ways to manage and apply large-scale, dense, and time-variant 3D point clouds as required by a rapidly growing number of applications and systems.},
  language  = {en}
}
@phdthesis{Alhajturki2018,
  author    = {Alhajturki, Dema},
  title     = {Characterization of altered inflorescence architecture in Arabidopsis thaliana BG-5 x Kro-0 hybrid},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420934},
  school      = {Universit{\"a}t Potsdam},
  pages     = {109},
  year      = {2018},
  abstract  = {A reciprocal cross between two A. thaliana accessions, Kro-0 (Krotzenburg, Germany) and BG-5 (Seattle, USA), displays purple rosette leaves and dwarf bushy phenotype in F1 hybrids when grown at 17 °C and a parental-like phenotype when grown at 21 °C. This F1 temperature-dependent-dwarf-bushy phenotype is characterized by reduced growth of the primary stem together with an increased number of branches. The reduced stem growth was the strongest at the first internode. In addition, we found that a temperature switch from 21 °C to 17 °C induced the phenotype only before the formation of the first internode of the stem. Similarly, the F1 dwarf-bushy phenotype could not be reversed when plants were shifted from 17 °C to 21 °C after the first internode was formed. Metabolic analysis showed that the F1 phenotype was associated with a significant upregulation of anthocyanin(s), kaempferol(s), salicylic acid, jasmonic acid and abscisic acid. As it has been previously shown that the dwarf-bushy phenotype is linked to two loci, one on chromosome 2 from Kro-0 and one on chromosome 3 from BG-5, an artificial micro-RNA approach was used to investigate the necessary genes on these intervals. From the results obtained, it was found that two genes, AT2G14120 that encodes for a DYNAMIN RELATED PROTEIN3B and AT2G14100 that encodes a member of the Cytochrome P450 family protein CYP705A13, were necessary for the appearance of the F1 phenotype on chromosome 2. It was also discovered that AT3G61035 that encodes for another cytochrome P450 family protein CYP705A13 and AT3G60840 that encodes for a MICROTUBULE-ASSOCIATED PROTEIN65-4 on chromosome 3 were both necessary for the induction of the F1 phenotype. To prove the causality of these genes, genomic constructs of the Kro-0 candidate genes on chromosome 2 were transferred to BG-5 and genomic constructs of the chromosome 3 candidate genes from BG-5 were transferred to Kro-0. The T1 lines showed that these genes are not sufficient alone to induce the phenotype. In addition to the F1 phenotype, more severe phenotypes were observed in the F2 generations that were grouped into five different phenotypic classes. Whilst seed yield was comparable between F1 hybrids and parental lines, three phenotypic classes in the F2 generation exhibited hybrid breakdown in the form of reproductive failure. This F2 hybrid breakdown was less sensitive to temperature and showed a dose-dependent effect of the loci involved in F1 phenotype. The severest class of hybrid breakdown phenotypes was observed only in the population of backcross with the parent Kro-0, which indicates a stronger contribution of the BG-5 allele when compared to the Kro-0 allele on the hybrid breakdown phenotypes. Overall, the findings of my thesis provide a further understanding of the genetic and metabolic factors underlying altered shoot architecture in hybrid dysfunction.},
  language  = {en}
}
@phdthesis{Behrens2018,
  author    = {Behrens, Ricarda},
  title     = {Causes for slow weathering and erosion in the steep, warm, monsoon-subjected Highlands of Sri Lanka},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-408503},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ix, 107, XXIV},
  year      = {2018},
  abstract  = {In the Highlands of Sri Lanka, erosion and chemical weathering rates are among the lowest for global mountain denudation. In this tropical humid setting, highly weathered deep saprolite profiles have developed from high-grade metamorphic charnockite during spheroidal weathering of the bedrock. The spheroidal weathering produces rounded corestones and spalled rindlets at the rock-saprolite interface. I used detailed textural, mineralogical, chemical, and electron-microscopic (SEM, FIB, TEM) analyses to identify the factors limiting the rate of weathering front advance in the profile, the sequence of weathering reactions, and the underlying mechanisms. The first mineral attacked by weathering was found to be pyroxene initiated by in situ Fe oxidation, followed by in situ biotite oxidation. Bulk dissolution of the primary minerals is best described with a dissolution - re-precipitation process, as no chemical gradients towards the mineral surface and sharp structural boundaries are observed at the nm scale. Only the local oxidation in pyroxene and biotite is better described with an ion by ion process. The first secondary phases are oxides and amorphous precipitates from which secondary minerals (mainly smectite and kaolinite) form. Only for biotite direct solid state transformation to kaolinite is likely. The initial oxidation of pyroxene and biotite takes place in locally restricted areas and is relatively fast: log J = -11 molmin/(m2 s). However, calculated corestone-scale mineral oxidation rates are comparable to corestone-scale mineral dissolution rates: log R = -13 molpx/(m2 s) and log R = -15 molbt/(m2 s). The oxidation reaction results in a volume increase. Volumetric calculations suggest that this observed oxidation leads to the generation of porosity due to the formation of micro-fractures in the minerals and the bedrock allowing for fluid transport and subsequent dissolution of plagioclase. At the scale of the corestone, this fracture reaction is responsible for the larger fractures that lead to spheroidal weathering and to the formation of rindlets. Since these fractures have their origin from the initial oxidational induced volume increase, oxidation is the rate limiting parameter for weathering to take place. The ensuing plagioclase weathering leads to formation of high secondary porosity in the corestone over a distance of only a few cm and eventually to the final disaggregation of bedrock to saprolite. As oxidation is the first weathering reaction, the supply of O2 is a rate-limiting factor for chemical weathering. Hence, the supply of O2 and its consumption at depth connects processes at the weathering front with erosion at the surface in a feedback mechanism. The strength of the feedback depends on the relative weight of advective versus diffusive transport of O2 through the weathering profile. The feedback will be stronger with dominating diffusive transport. The low weathering rate ultimately depends on the transport of O2 through the whole regolith, and on lithological factors such as low bedrock porosity and the amount of Fe-bearing primary minerals. In this regard the low-porosity charnockite with its low content of Fe(II) bearing minerals impedes fast weathering reactions. Fresh weatherable surfaces are a pre-requisite for chemical weathering. However, in the case of the charnockite found in the Sri Lankan Highlands, the only process that generates these surfaces is the fracturing induced by oxidation. Tectonic quiescence in this region and low pre-anthropogenic erosion rate (attributed to a dense vegetation cover) minimize the rejuvenation of the thick and cohesive regolith column, and lowers weathering through the feedback with erosion.},
  language  = {en}
}
@phdthesis{Stolle2018,
  author    = {Stolle, Amelie},
  title     = {Catastrophic Sediment Pulses in the Pokhara Valley, Nepal},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-413341},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XVII, 173},
  year      = {2018},
  abstract  = {Fluvial terraces, floodplains, and alluvial fans are the main landforms to store sediments and to decouple hillslopes from eroding mountain rivers. Such low-relief landforms are also preferred locations for humans to settle in otherwise steep and poorly accessible terrain. Abundant water and sediment as essential sources for buildings and infrastructure make these areas amenable places to live at. Yet valley floors are also prone to rare and catastrophic sedimentation that can overload river systems by abruptly increasing the volume of sediment supply, thus causing massive floodplain aggradation, lateral channel instability, and increased flooding. Some valley-fill sediments should thus record these catastrophic sediment pulses, allowing insights into their timing, magnitude, and consequences. This thesis pursues this theme and focuses on a prominent ~150 km2 valley fill in the Pokhara Valley just south of the Annapurna Massif in central Nepal. The Pokhara Valley is conspicuously broad and gentle compared to the surrounding dissected mountain terrain, and is filled with locally more than 70 m of clastic debris. The area's main river, Seti Khola, descends from the Annapurna Sabche Cirque at 3500-4500 m asl down to 900 m asl where it incises into this valley fill. Humans began to settle on this extensive fan surface in the 1750's when the Trans-Himalayan trade route connected the Higher Himalayas, passing Pokhara city, with the subtropical lowlands of the Terai. High and unstable river terraces and steep gorges undermined by fast flowing rivers with highly seasonal (monsoon-driven) discharge, a high earthquake risk, and a growing population make the Pokhara Valley an ideal place to study the recent geological and geomorphic history of its sediments and the implication for natural hazard appraisals. The objective of this thesis is to quantify the timing, the sedimentologic and geomorphic processes as well as the fluvial response to a series of strong sediment pulses. I report diagnostic sedimentary archives, lithofacies of the fan terraces, their geochemical provenance, radiocarbon-age dating and the stratigraphic relationship between them. All these various and independent lines of evidence show consistently that multiple sediment pulses filled the Pokhara Valley in medieval times, most likely in connection with, if not triggered by, strong seismic ground shaking. The geomorphic and sedimentary evidence is consistent with catastrophic fluvial aggradation tied to the timing of three medieval Himalayan earthquakes in ~1100, 1255, and 1344 AD. Sediment provenance and calibrated radiocarbon-age data are the key to distinguish three individual sediment pulses, as these are not evident from their sedimentology alone. I explore various measures of adjustment and fluvial response of the river system following these massive aggradation pulses. By using proxies such as net volumetric erosion, incision and erosion rates, clast provenance on active river banks, geomorphic markers such as re-exhumed tree trunks in growth position, and knickpoint locations in tributary valleys, I estimate the response of the river network in the Pokhara Valley to earthquake disturbance over several centuries. Estimates of the removed volumes since catastrophic valley filling began, require average net sediment yields of up to 4200 t km-2 yr-1 since, rates that are consistent with those reported for Himalayan rivers. The lithological composition of active channel-bed load differs from that of local bedrock material, confirming that rivers have adjusted 30-50\% depending on data of different tributary catchments, locally incising with rates of 160-220 mm yr-1. In many tributaries to the Seti Khola, most of the contemporary river loads come from a Higher Himalayan source, thus excluding local hillslopes as sources. This imbalance in sediment provenance emphasizes how the medieval sediment pulses must have rapidly traversed up to 70 km downstream to invade the downstream reaches of the tributaries up to 8 km upstream, thereby blocking the local drainage and thus reinforcing, or locally creating new, floodplain lakes still visible in the landscape today. Understanding the formation, origin, mechanism and geomorphic processes of this valley fill is crucial to understand the landscape evolution and response to catastrophic sediment pulses. Several earthquake-triggered long-runout rock-ice avalanches or catastrophic dam burst in the Higher Himalayas are the only plausible mechanisms to explain both the geomorphic and sedimentary legacy that I document here. In any case, the Pokhara Valley was most likely hit by a cascade of extremely rare processes over some two centuries starting in the early 11th century. Nowhere in the Himalayas do we find valley fills of comparable size and equally well documented depositional history, making the Pokhara Valley one of the most extensively dated valley fill in the Himalayas to date. Judging from the growing record of historic Himalayan earthquakes in Nepal that were traced and dated in fault trenches, this thesis shows that sedimentary archives can be used to directly aid reconstructions and predictions of both earthquake triggers and impacts from a sedimentary-response perspective. The knowledge about the timing, evolution, and response of the Pokhara Valley and its river system to earthquake triggered sediment pulses is important to address the seismic and geomorphic risk for the city of Pokhara. This thesis demonstrates how geomorphic evidence on catastrophic valley infill can help to independently verify paleoseismological fault-trench records and may initiate re-thinking on post-seismic hazard assessments in active mountain regions.},
  language  = {en}
}
@phdthesis{Witt2018,
  author    = {Witt, Tanja Ivonne},
  title     = {Camera Monitoring at volcanoes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421073},
  school      = {Universit{\"a}t Potsdam},
  pages     = {viii, 140},
  year      = {2018},
  abstract  = {Basaltic fissure eruptions, such as on Hawai'i or on Iceland, are thought to be driven by the lateral propagation of feeder dikes and graben subsidence. Associated solid earth processes, such as deformation and structural development, are well studied by means of geophysical and geodetic technologies. The eruptions themselves, lava fountaining and venting dynamics, in turn, have been much less investigated due to hazardous access, local dimension, fast processes, and resulting poor data availability. This thesis provides a detailed quantitative understanding of the shape and dynamics of lava fountains and the morphological changes at their respective eruption sites. For this purpose, I apply image processing techniques, including drones and fixed installed cameras, to the sequence of frames of video records from two well-known fissure eruptions in Hawai'i and Iceland. This way I extract the dimensions of multiple lava fountains, visible in all frames. By putting these results together and considering the acquisition times of the frames I quantify the variations in height, width and eruption velocity of the lava fountains. Then I analyse these time-series in both time and frequency domains and investigate the similarities and correlations between adjacent lava fountains. Following this procedure, I am able to link the dynamics of the individual lava fountains to physical parameters of the magma transport in the feeder dyke of the fountains. The first case study in this thesis focuses on the March 2011 Pu'u'O'o eruption, Hawai'i, where a continuous pulsating behaviour at all eight lava fountains has been observed. The lava fountains, even those from different parts of the fissure that are closely connected, show a similar frequency content and eruption behaviour. The regular pattern in the heights of lava fountain suggests a controlling process within the magma feeder system like a hydraulic connection in the underlying dyke, affecting or even controlling the pulsating behaviour. The second case study addresses the 2014-2015 Holuhraun fissure eruption, Iceland. In this case, the feeder dyke is highlighted by the surface expressions of graben-like structures and fault systems. At the eruption site, the activity decreases from a continuous line of fire of ~60 vents to a limited number of lava fountains. This can be explained by preferred upwards magma movements through vertical structures of the pre-eruptive morphology. Seismic tremors during the eruption reveal vent opening at the surface and/or pressure changes in the feeder dyke. The evolving topography of the cinder cones during the eruption interacts with the lava fountain behaviour. Local variations in the lava fountain height and width are controlled by the conduit diameter, the depth of the lava pond and the shape of the crater. Modelling of the fountain heights shows that long-term eruption behaviour is controlled mainly by pressure changes in the feeder dyke. This research consists of six chapters with four papers, including two first author and two co-author papers. It establishes a new method to analyse lava fountain dynamics by video monitoring. The comparison with the seismicity, geomorphologic and structural expressions of fissure eruptions shows a complex relationship between focussed flow through dykes, the morphology of the cinder cones, and the lava fountain dynamics at the vents of a fissure eruption.},
  language  = {en}
}
@phdthesis{Khalil2018,
  author    = {Khalil, Sara},
  title     = {Boundary Value Problems on Manifolds with Singularities},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419018},
  school      = {Universit{\"a}t Potsdam},
  pages     = {10, 160},
  year      = {2018},
  abstract  = {In the thesis there are constructed new quantizations for pseudo-differential boundary value problems (BVPs) on manifolds with edge. The shape of operators comes from Boutet de Monvel's calculus which exists on smooth manifolds with boundary. The singular case, here with edge and boundary, is much more complicated. The present approach simplifies the operator-valued symbolic structures by using suitable Mellin quantizations on infinite stretched model cones of wedges with boundary. The Mellin symbols themselves are, modulo smoothing ones, with asymptotics, holomorphic in the complex Mellin covariable. One of the main results is the construction of parametrices of elliptic elements in the corresponding operator algebra, including elliptic edge conditions.},
  language  = {en}
}
@phdthesis{Sakowski2018,
  author    = {Sakowski, Fabian},
  title     = {Bodennutzung in der New Economic Geography},
  series = {Potsdamer Schriften zur Raumwirtschaft},
  journal   = {Potsdamer Schriften zur Raumwirtschaft},
  number    = {7},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-426-5},
  issn      = {2190-8702},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-413737},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xiv, 290},
  year      = {2018},
  abstract  = {Mit der New Economic Geography (NEG) kann die Verteilung von Unternehmen und Arbeitskr{\"a}ften auf Regionen modellhaft diskutiert werden. In diesem Beitrag wird untersucht, welche r{\"a}umlichen Verteilungen der mobilen Arbeitskr{\"a}fte und Unternehmen in einem NEG-Modellansatz resultieren, wenn die Gr{\"o}ße einer Region und damit der ihr zur Verf{\"u}gung stehende Boden, die zu {\"u}berwindende Distanz f{\"u}r den G{\"u}tertransport innerhalb der Regionen, sowie Bodennutzungskonkurrenzen zwischen Wohnen, Industrie und Landwirtschaft ber{\"u}cksichtigt werden. Auch wird der Frage nachgegangen, welche Wohlfahrtswirkungen hierbei resultieren.},
  language  = {de}
}
@phdthesis{Genderjahn2018,
  author    = {Genderjahn, Steffi},
  title     = {Biosignatures of Present and Past Microbial Life in Southern African Geoarchives},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-410110},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XI, 166, xxii},
  year      = {2018},
  abstract  = {Global climate change is one of the greatest challenges of the 21st century, with influence on the environment, societies, politics and economies. The (semi-)arid areas of Southern Africa already suffer from water scarcity. There is a great variety of ongoing research related to global climate history but important questions on regional differences still exist. In southern African regions terrestrial climate archives are rare, which makes paleoclimate studies challenging. Based on the assumption that continental pans (sabkhas) represent a suitable geo-archive for the climate history, two different pans were studied in the southern and western Kalahari Desert. A combined approach of molecular biological and biogeochemical analyses is utilized to investigate the diversity and abundance of microorganisms and to trace temporal and spatial changes in paleoprecipitation in arid environments. The present PhD thesis demonstrates the applicability of pan sediments as a late Quaternary geo-archive based on microbial signature lipid biomarkers, such as archaeol, branched and isoprenoid glycerol dialkyl glycerol tetraethers (GDGTs) as well as phospholipid fatty acids (PLFA). The microbial signatures contained in the sediment provide information on the current or past microbial community from the Last Glacial Maximum to the recent epoch, the Holocene. The results are discussed in the context of regional climate evolution in southwestern Africa. The seasonal shift of the Innertropical Convergence Zone (ITCZ) along the equator influences the distribution of precipitation- and climate zones. The different expansion of the winter- and summer rainfall zones in southern Africa was confirmed by the frequency of certain microbial biomarkers. A period of increased precipitation in the south-western Kalahari could be described as a result of the extension of the winter rainfall zone during the last glacial maximum (21 ± 2 ka). Instead a period of increased paleoprecipitation in the western Kalahari was indicated during the Late Glacial to Holocene transition. This was possibly caused by a southwestern shift in the position of the summer rainfall zone associated to the southward movement of the ITCZ. Furthermore, for the first time this study characterizes the bacterial and archaeal life based on 16S rRNA gene high-throughput sequencing in continental pan sediments and provides an insight into the recent microbial community structure. Near-surface processes play an important role for the modern microbial ecosystem in the pans. Water availability as well as salinity might determine the abundance and composition of the microbial communities. The microbial community of pan sediments is dominated by halophilic and dry-adapted archaea and bacteria. Frequently occurring microorganisms such as, Halobacteriaceae, Bacillus and Gemmatimonadetes are described in more detail in this study.},
  language  = {en}
}
@phdthesis{Klimczak2018,
  author    = {Klimczak, Franziska},
  title     = {Bildlichkeit und Metaphorik in sp{\"a}tmittelalterlichen Fastnachtspielen des 15. Jahrhunderts},
  isbn      = {978-3-86956-408-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-397320},
  school      = {Universit{\"a}t Potsdam},
  pages     = {208},
  year      = {2018},
  abstract  = {Die Dissertation untersucht die Sexualmetaphorik im N{\"u}rnberger Fastnachtspiel des 15. Jahrhunderts und w{\"a}hlt als Textgrundlage die Ausgabe der N{\"u}rnberger Fastnachtspiele von Adelbert von Keller als einzig vollst{\"a}ndige Sammlung. Anliegen der Dissertation ist es, die Einzigartigkeit des Wortschatzes des Fastnachtspiels herauszuarbeiten, indem mit Fokus auf die Bildhaftigkeit und die Metaphorik der obsz{\"o}nen Redeweise {\"u}ber deren Aussage- und Wirkkraft im historischen Fastnachtspielkontext reflektiert wird. Wie die Metapher gezielt tabuisierte, intime Inhalte zum Zwecke der Komik legitimiert, wird erst theoretisch ergr{\"u}ndet und dann in einer Interpretation der sprachlichen Gestaltung von Sexualit{\"a}t und Obsz{\"o}nit{\"a}t mit Blick auf den soziokulturellen Hintergrund des N{\"u}rnberger Fastnachtspiels kritisch reflektiert. In einer interdisziplin{\"a}ren Ann{\"a}herung werden zun{\"a}chst sowohl Erkenntnisse und Theorien aus der Fastnachtspiel- und Mittelalterforschung als auch theoretische Ans{\"a}tze aus der Metaphorologie und der Komikforschung zusammengetragen und diskutiert. Im Rahmen des breitgef{\"a}cherten, wissenschaftlichen Diskurses zu den Fastnachtspielen wird das N{\"u}rnberger Fastnachtspiel aus inhaltlicher, funktionaler, genderbezogener, kulturgeschichtlicher und sprachlicher Perspektive beleuchtet, um ein besseres Verst{\"a}ndnis der Sprache des Fastnachtspiels zu erlangen. Im n{\"a}chsten Schritt werden das mittelalterliche Ehe- und Familienleben und die soziale und rechtliche Stellung von Mann und Frau analysiert, indem theologisch-normativer und literarischer Ehediskurs einander gegen{\"u}bergestellt und gattungsspezifisch untersucht werden. So k{\"o}nnen Logiken und Verfahrensweisen in der mittelalterlichen Alltags-, Glaubens- und Rechtspraxis aufgedeckt werden. Dadurch ist es m{\"o}glich, die Inszenierungen des K{\"o}rpers im Fastnachtspiel einzusch{\"a}tzen, die die mittelalterliche Sexualmoral verhandeln und so mannigfaltige Bilder und Vorstellungen von Mann und Frau entwerfen. Anschließend wird in der Diskussion relevanter Metapherntheorien ergr{\"u}ndet, wie die metaphorische Sprache dabei den obsz{\"o}nen Inhalten gleichzeitig die T{\"u}r {\"o}ffnet und sie auf Distanz h{\"a}lt. Bei der Betrachtung poststrukturalistischer, erkenntnistheoretischer, kognitiver, semantischer und philosophischer Theorien zur Beschreibung der Arbeits- und Wirkweise der Metapher erweisen sich insbesondere analogieorientierte und funktionale Ans{\"a}tze als gewinnbringend, weil sie die Kontextualisierung der Metapher als bindend voraussetzen und sie als komplexes, metakognitives Ph{\"a}nomen diskutieren, das auf Interaktions- und {\"U}bertragungsprozessen beruht. Sodann werden die vielf{\"a}ltigen Anl{\"a}sse, sozialen Formen und Funktionen des Lachens in der mittelalterlichen Gesellschaft n{\"a}her in den Blick genommen, um den komisch-derbsinnlichen Duktus der Fastnachtspiele nachvollziehen zu k{\"o}nnen. Mit der Bewusstmachung wiederkehrender Elemente und Muster des Komischen kann der Unterhaltungswert der Fastnachtspielsprache exemplarisch verdeutlicht werden. Die sich anschließende umfassende Interpretation der Fastnachtspiele wird methodisch angeleitet durch die Theorie der bildlichen Rede von Hans Georg Coenen. Er bleibt mit seinen Analogiedefinitionen der klassischen Rhetorik verpflichtet und unterscheidet unter anderem „kreative", „konventionalisierte" und „lexikalisierte" Metaphern. Bei der außerordentlichen Vielfalt sexualmetaphorischer Ausdrucksweisen liegt der Fokus auf den Darstellungen der Geschlechtsorgane von Mann und Frau und dem Koitus. Die Verfasserin gelangt zu folgenden Ergebnissen: Die Metapher sorgt durch ihre bildgestaltende Vermittlung jeweils daf{\"u}r, dass der sexuelle Inhalt darstellbar wird, ohne jedoch in unmissverst{\"a}ndlicher Direktheit auf den Betrachter zu treffen. Ob sie mit ihren allt{\"a}glichen, meist b{\"a}uerlichen Bildmotiven f{\"u}r die Schamsph{\"a}re {\"u}ber- oder untertreibt, abwertet oder aufwertet, verh{\"u}llt oder entlarvt - in jedweder Form und Gestalt kann die Metapher den sexuellen Inhalt {\"a}sthetisieren. Weil sie ihn unter neuer oder anderer Perspektive betrachtet, entr{\"u}ckt sie ihn formal. Damit erscheint das Sprechen {\"u}ber Sexualit{\"a}t in der metaphorischen Rede wie auf Abstand gerechtfertigt und das Ausmaß bzw. {\"U}bermaß der Inszenierung von Sexualit{\"a}t im Fastnachtspiel {\"u}berhaupt erst m{\"o}glich. H{\"a}ufig werden Bilder vom Penis als Esel, von der Vagina als Wiese und vom Koitus als Speerkampf entworfen. Die Metapher stellt damit gewohnte Vorstellungen von Mann und Frau mitsamt den normativ gesetzten Erwartungen und Strukturen im Eheleben auf den Kopf. Das kann als obsz{\"o}n und unanst{\"a}ndig, aber auch als am{\"u}sant empfunden worden sein und heute noch empfunden werden. Immer bleibt die Metapher dabei ambigue. In ihrer mehrkanaligen Wirkweise, ihrer innovativen Kraft und auch in ihrer Widerspr{\"u}chlichkeit liegen ihre dichterische Begabung und ihre Qualit{\"a}t zur Komisierung. Damit stellt sich die kunstfertige Sprache des Fastnachtspiels der K{\"o}rperlichkeit der Spielinhalte entgegen. Die Dissertation demonstriert das innovative, normkritische Potenzial der Fastnachtspielsprache, die sie als eine Poetik der Ambiguit{\"a}t lesbar und als einen Schatz an vielf{\"a}ltigen und differenzierten Ausdrucksweisen f{\"u}r die Schamsph{\"a}re wertsch{\"a}tzbar macht. Damit leistet die Arbeit einen wichtigen Beitrag zur sprach- und literaturwissenschaftlichen Analyse des N{\"u}rnberger Fastnachtsspiels und zu einem differenzierteren Verst{\"a}ndnis von dessen kulturgeschichtlicher Bedeutung.},
  language  = {de}
}
@phdthesis{Codutti2018,
  author    = {Codutti, Agnese},
  title     = {Behavior of magnetic microswimmers},
  doi       = {10.25932/publishup-42297},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-422976},
  school      = {Universit{\"a}t Potsdam},
  pages     = {iv, 142},
  year      = {2018},
  abstract  = {Microswimmers, i.e. swimmers of micron size experiencing low Reynolds numbers, have received a great deal of attention in the last years, since many applications are envisioned in medicine and bioremediation. A promising field is the one of magnetic swimmers, since magnetism is biocom-patible and could be used to direct or actuate the swimmers. This thesis studies two examples of magnetic microswimmers from a physics point of view. The first system to be studied are magnetic cells, which can be magnetic biohybrids (a swimming cell coupled with a magnetic synthetic component) or magnetotactic bacteria (naturally occurring bacteria that produce an intracellular chain of magnetic crystals). A magnetic cell can passively interact with external magnetic fields, which can be used for direction. The aim of the thesis is to understand how magnetic cells couple this magnetic interaction to their swimming strategies, mainly how they combine it with chemotaxis (the ability to sense external gradient of chemical species and to bias their walk on these gradients). In particular, one open question addresses the advantage given by these magnetic interactions for the magnetotactic bacteria in a natural environment, such as porous sediments. In the thesis, a modified Active Brownian Particle model is used to perform simulations and to reproduce experimental data for different systems such as bacteria swimming in the bulk, in a capillary or in confined geometries. I will show that magnetic fields speed up chemotaxis under special conditions, depending on parameters such as their swimming strategy (run-and-tumble or run-and-reverse), aerotactic strategy (axial or polar), and magnetic fields (intensities and orientations), but it can also hinder bacterial chemotaxis depending on the system. The second example of magnetic microswimmer are rigid magnetic propellers such as helices or random-shaped propellers. These propellers are actuated and directed by an external rotating magnetic field. One open question is how shape and magnetic properties influence the propeller behavior; the goal of this research field is to design the best propeller for a given situation. The aim of the thesis is to propose a simulation method to reproduce the behavior of experimentally-realized propellers and to determine their magnetic properties. The hydrodynamic simulations are based on the use of the mobility matrix. As main result, I propose a method to match the experimental data, while showing that not only shape but also the magnetic properties influence the propellers swimming characteristics.},
  language  = {en}
}
@phdthesis{Kraft2018,
  author    = {Kraft, Frederik},
  title     = {Be Creative, Now!},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414009},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VII, 230},
  year      = {2018},
  abstract  = {Purpose - This thesis set out to explore, describe, and evaluate the reality behind the rhetoric of freedom and control in the context of creativity. The overarching subject is concerned with the relationship between creativity, freedom, and control, considering freedom is also seen as an element of control to manage creativity. Design/methodology/approach - In-depth qualitative data gathered from at two innovative start-ups. Two ethnographic studies were conducted. The data are based on participatory observations, interviews, and secondary sources, each of which included a three months field study and a total of 41 interviews from both organizations. Findings - The thesis provides explanations for the practice of freedom and the control of creativity within organizations and expands the existing theory of neo-normative control. The findings indicate that organizations use complex control systems that allow a high degree of freedom that paradoxically leads to more control. Freedom is a cover of control, which in turn leads to creativity. Covert control even results in the responsibility to be creative outside working hours. Practical implications - Organizations, which rely on creativity might use the results of this thesis. Positive workplace control of creativity provides both freedom and structure for creative work. While freedom leads to organizational members being more motivated and committing themselves more strongly to their and the organization's goals, and a specific structure also helps to provide the requirements for creativity. Originality/value - The thesis provides an insight into an approach to workplace control, which has mostly neglected in creativity research and proposes a modified concept of neo-normative control. It serves to provide a further understanding of freedom for creativity and to challenge the liberal claims of new control forms.},
  language  = {en}
}
@phdthesis{Pavleski2018,
  author    = {Pavleski, Stefan},
  title     = {Arbeitslosigkeit in S{\"u}dosteuropa im Kontext der EU-Integration},
  series = {Potsdam Economic Studies},
  journal   = {Potsdam Economic Studies},
  number    = {7},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-421-0},
  issn      = {2196-8691},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-404287},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxi, 263},
  year      = {2018},
  abstract  = {Diese Arbeit besteht aus drei Aufs{\"a}tzen. Der erste Aufsatz („Die Arbeitsmarktpolitik in S{\"u}dosteuropa: Von der Transformation bis zur EU-Integration") er{\"o}rtert die wirtschaftlichen und politischen Rahmenbedingungen in S{\"u}dosteuropa und die damit einhergehenden Entwicklungen auf den jeweiligen Arbeitsm{\"a}rkten seit 1991. Im Fokus steht dabei der Einfluss der Arbeitslosigkeit (als systemunabh{\"a}ngiges Problem) auf den EU-Integrationsprozess in den jugoslawischen Nachfolgestaaten und Albanien. Welchen Einfluss haben der qualifikatorische und regionale Mismatch auf die Arbeitslosigkeit in Kroatien? Um diese Frage zu beantworten, wird im zweiten Kapitel dieser Arbeit („Arbeitslosigkeit im Transformationsprozess: Qualifikatorischer und regionaler Mismatch in Kroatien") der Mismatch sowohl statisch mit Mismatch-Indikatoren als auch dynamisch im Rahmen der Matching-Funktion er{\"o}rtert. Unter Anwendung von Paneldaten f{\"u}r neun Berufsgruppen und 21 Regionen im Zeitraum zwischen Januar 2004 und Juni 2015 wird in diesem Kapitel mithilfe von Fixed-Effects-Modellen dieser Einfluss gesch{\"a}tzt. F{\"u}hrt die Anpassung der Arbeitslosenversicherungsgesetze an die EU-Standards zu einer Verbesserung der Arbeitsmarktergebnisse in den Staaten S{\"u}dosteuropas? Mit Hilfe von Paneldaten f{\"u}r den Zeitraum 1996-2014 wird f{\"u}r f{\"u}nf s{\"u}dosteurop{\"a}ische Staaten (Albanien, Kroatien, Mazedonien, Montenegro und Serbien) dieser Einfluss im Rahmen eines Differenz-in-Differenzen-Modells im dritten Aufsatz („Unvollst{\"a}ndige Integration: Eine Differenz-in-Differenzen-Analyse der s{\"u}dosteurop{\"a}ischen Arbeitsm{\"a}rkte") gesch{\"a}tzt.},
  language  = {de}
}
@phdthesis{Ma2018,
  author    = {Ma, Siyuan},
  title     = {Analysis of Teukolsky equations on slowly rotating Kerr spacetimes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414781},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vi, 89},
  year      = {2018},
  abstract  = {In this thesis, we treat the extreme Newman-Penrose components of both the Maxwell field (s=±1) and the linearized gravitational perturbations (or "linearized gravity" for short) (s=±2) in the exterior of a slowly rotating Kerr black hole. Upon different rescalings, we can obtain spin s components which satisfy the separable Teukolsky master equation (TME). For each of these spin s components defined in Kinnersley tetrad, the resulting equations by performing some first-order differential operator on it once and twice (twice only for s=±2), together with the TME, are in the form of an "inhomogeneous spin-weighted wave equation" (ISWWE) with different potentials and constitute a linear spin-weighted wave system. We then prove energy and integrated local energy decay (Morawetz) estimates for this type of ISWWE, and utilize them to achieve both a uniform bound of a positive definite energy and a Morawetz estimate for the regular extreme Newman-Penrose components defined in the regular Hawking-Hartle tetrad. We also present some brief discussions on mode stability for TME for the case of real frequencies. This says that in a fixed subextremal Kerr spacetime, there is no nontrivial separated mode solutions to TME which are purely ingoing at horizon and purely outgoing at infinity. This yields a representation formula for solutions to inhomogeneous Teukolsky equations, and will play a crucial role in generalizing the above energy and Morawetz estimates results to the full subextremal Kerr case.},
  language  = {en}
}
@phdthesis{Kegeles2018,
  author    = {Kegeles, Alexander},
  title     = {Algebraic foundation of Group Field Theory},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421014},
  school      = {Universit{\"a}t Potsdam},
  pages     = {124},
  year      = {2018},
  abstract  = {In this thesis we provide a construction of the operator framework starting from the functional formulation of group field theory (GFT). We define operator algebras on Hilbert spaces whose expectation values in specific states provide correlation functions of the functional formulation. Our construction allows us to give a direct relation between the ingredients of the functional GFT and its operator formulation in a perturbative regime. Using this construction we provide an example of GFT states that can not be formulated as states in a Fock space and lead to math- ematically inequivalent representations of the operator algebra. We show that such inequivalent representations can be grouped together by their symmetry properties and sometimes break the left translation symmetry of the GFT action. We interpret these groups of inequivalent representations as phases of GFT, similar to the classification of phases that we use in QFT's on space-time.},
  language  = {en}
}
@phdthesis{Gidion2018,
  author    = {Gidion, Gunnar},
  title     = {Akustische Resonatoren zur Analyse und Kontrolle von schwingungsf{\"a}higen Systemen am Beispiel von Streichinstrumenten und Dielektrischen Elastomeraktoren},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-411772},
  school      = {Universit{\"a}t Potsdam},
  pages     = {190},
  year      = {2018},
  abstract  = {Die Klangeigenschaften von Musikinstrumenten werden durch das Zusammenwirken der auf ihnen anregbaren akustischen Schwingungsmoden bestimmt, welche sich wiederum aus der geometrischen Struktur des Resonators in Kombination mit den verwendeten Materialien ergeben. In dieser Arbeit wurde das Schwingungsverhalten von Streichinstrumenten durch den Einsatz minimal-invasiver piezoelektrischer Polymerfilmsensoren untersucht. Die studierten Kopplungsph{\"a}nomene umfassen den sogenannten Wolfton und Schwingungstilger, die zu dessen Abschw{\"a}chung verwendet werden, sowie die gegenseitige Beeinflussung von Bogen und Instrument beim Spielvorgang. An Dielektrischen Elastomeraktormembranen wurde dagegen der Einfluss der elastischen Eigenschaften des Membranmaterials auf das akustische und elektromechanische Schwingungsverhalten gezeigt. Die Dissertation gliedert sich in drei Teile, deren wesentliche Ergebnisse im Folgenden zusammengefasst werden. In Teil I wurde die Funktionsweise eines abstimmbaren Schwingungstilgers zur D{\"a}mpfung von Wolft{\"o}nen auf Streichinstrumenten untersucht. Durch Abstimmung der Resonanzfrequenz des Schwingungstilgers auf die Wolftonfrequenz kann ein Teil der Saitenschwingungen absorbiert werden, so dass die zu starke Anregung der Korpusresonanz vermieden wird, die den Wolfton verursacht. Der Schwingungstilger besteht aus einem „Wolft{\"o}ter", einem Massest{\"u}ck, welches auf der Nachl{\"a}nge der betroffenen Saite (zwischen Steg und Saitenhalter) installiert wird. Hier wurde gezeigt, wie die Resonanzen dieses Schwingungstilgers von der Masse des Wolft{\"o}ters und von dessen Position auf der Nachl{\"a}nge abh{\"a}ngen. Aber auch die Geometrie des Wolft{\"o}ters stellte sich als ausschlaggebend heraus, insbesondere bei einem nicht-rotationssymmetrischen Wolft{\"o}ter: In diesem Fall entsteht - basierend auf den zu erwartenden nicht-harmonischen Moden einer massebelasteten Saite - eine zus{\"a}tzliche Mode, die von der Polarisationsrichtung der Saitenschwingung abh{\"a}ngt. Teil II der Dissertation befasst sich mit Elastomermembranen, die als Basis von Dielektrischen Elastomeraktoren dienen, und die wegen der Membranspannung auch akustische Resonanzen aufweisen. Die Ansprache von Elastomeraktoren h{\"a}ngt unter anderem von der Geschwindigkeit der elektrischen Anregung ab. Die damit zusammenh{\"a}ngenden viskoelastischen Eigenschaften der hier verwendeten Elastomere, Silikon und Acrylat, wurden einerseits in einer frequenzabh{\"a}ngigen dynamisch-mechanischen Analyse des Elastomers erfasst, andererseits auch optisch an vollst{\"a}ndigen Aktoren selbst gemessen. Die h{\"o}here Viskosit{\"a}t des Acrylats, das bei tieferen Frequenzen h{\"o}here Aktuationsdehnungen als das Silikon zeigt, f{\"u}hrt zu einer Verminderung der Dehnungen bei h{\"o}heren Frequenzen, so dass {\"u}ber etwa 40 Hertz mit Silikon gr{\"o}ßere Aktuationsdehnungen erreicht werden. Mit den untersuchten Aktoren konnte die Gitterkonstante weicher optischer Beugungsgitter kontrolliert werden, die als zus{\"a}tzlicher Film auf der Membran installiert wurden. {\"U}ber eine Messung der akustischen Resonanzfrequenz von Elastomermebranen aus Acrylat in 1Abh{\"a}ngigkeit von ihrer Vorstreckung konnte in Verbindung mit einer Modellierung des hyperelastischen Verhaltens des Elastomers (Ogden-Modell) der Schermodul bestimmt werden. Schließlich wird in Teil III die Untersuchung von Geigen und ihrer Streichanregung mit Hilfe minimal-invasiver piezoelektrischer Polymerfilme geschildert. Es konnten am Bogen und am Steg von Geigen - unter den beiden F{\"u}ßen des Stegs - jeweils zwei Filmsensoren installiert werden. Mit den beiden Sensoren am Steg wurden Frequenzg{\"a}nge von Geigen gemessen, welche eine Bestimmung der frequenzabh{\"a}ngigen Stegbewegung erlaubten. Diese Methode erm{\"o}glicht damit auch eine umfassende Charakterisierung der Signaturmoden in Bezug auf die Stegdynamik. Die Ergebnisse der komplement{\"a}ren Methoden von Impulsanregung und nat{\"u}rlichem Spielen der Geigen konnten dank der Sensoren verglichen werden. F{\"u}r die Nutzung der Sensoren am Bogen - insbesondere f{\"u}r eine Messung des Bogendrucks - wurde eine Kalibrierung des Bogen-Sensor-Systems mit Hilfe einer Materialpr{\"u}fmaschine durchgef{\"u}hrt. Bei einer Messung w{\"a}hrend des nat{\"u}rlichen Spielens wurde mit den Sensoren am Bogen einerseits die {\"U}bertragung der Saitenschwingung auf den Bogen festgestellt. Dabei konnten außerdem longitudinale Bogenhaarresonanzen identifiziert werden, die von der Position der Saite auf dem Bogen abh{\"a}ngen. Aus der Analyse dieses Ph{\"a}nomens konnte die longitudinale Wellengeschwindigkeit der Bogenhaare bestimmt werden, die eine wichtige Gr{\"o}ße f{\"u}r die Kopplung zwischen Saite und Bogen ist. Mit Hilfe des Systems aus Sensoren an Bogen und Steg werden auf Grundlage der vorliegenden Arbeit Studien an Streichinstrumenten vorgeschlagen, in denen die Bespielbarkeit der Instrumente zu den jeweils angeregten Steg- und Bogenschwingungen in Beziehung gesetzt werden kann. Damit k{\"o}nnte nicht zuletzt auch die bisher nicht vollst{\"a}ndig gekl{\"a}rte Rolle des Bogens f{\"u}r Klang und Bespielbarkeit besser beurteilt werden},
  language  = {de}
}
@phdthesis{Buschmann2018,
  author    = {Buschmann, Stefan},
  title     = {A software framework for GPU-based geo-temporal visualization techniques},
  doi       = {10.25932/publishup-44340},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-443406},
  school      = {Universit{\"a}t Potsdam},
  pages     = {viii, 99},
  year      = {2018},
  abstract  = {R{\"a}umlich-zeitliche Daten sind Daten, welche sowohl einen Raum- als auch einen Zeitbezug aufweisen. So k{\"o}nnen beispielsweise Zeitreihen von Geodaten, thematische Karten die sich {\"u}ber die Zeit ver{\"a}ndern, oder Bewegungsaufzeichnungen von sich bewegenden Objekten als r{\"a}umlich-zeitliche Daten aufgefasst werden. In der heutigen automatisierten Welt gibt es eine wachsende Anzahl von Datenquellen, die best{\"a}ndig r{\"a}umlich-zeitliche Daten generieren. Hierzu geh{\"o}ren beispielsweise Verkehrs{\"u}berwachungssysteme, die Bewegungsdaten von Menschen oder Fahrzeugen aufzeichnen, Fernerkundungssysteme, welche regelm{\"a}ßig unsere Umgebung scannen und digitale Abbilder wie z.B. Stadt- und Landschaftsmodelle erzeugen, sowie Sensornetzwerke in unterschiedlichsten Anwendungsgebieten, wie z.B. der Logistik, der Verhaltensforschung von Tieren, oder der Klimaforschung. Zur Analyse r{\"a}umlich-zeitlicher Daten werden neben der automatischen Analyse mittels statistischer Methoden und Data-Mining auch explorative Methoden angewendet, welche auf der interaktiven Visualisierung der Daten beruhen. Diese Methode der Analyse basiert darauf, dass Anwender in Form interaktiver Visualisierung die Daten explorieren k{\"o}nnen, wodurch die menschliche Wahrnehmung sowie das Wissen der User genutzt werden, um Muster zu erkennen und dadurch einen Einblick in die Daten zu erlangen. Diese Arbeit beschreibt ein Software-Framework f{\"u}r die Visualisierung r{\"a}umlich-zeitlicher Daten, welches GPU-basierte Techniken beinhaltet, um eine interaktive Visualisierung und Exploration großer r{\"a}umlich-zeitlicher Datens{\"a}tze zu erm{\"o}glichen. Die entwickelten Techniken umfassen Datenhaltung, Prozessierung und Rendering und erm{\"o}glichen es, große Datenmengen in Echtzeit zu prozessieren und zu visualisieren. Die Hauptbeitr{\"a}ge der Arbeit umfassen: - Konzept und Implementierung einer GPU-zentrierten Visualisierungspipeline. Die beschriebenen Techniken basieren auf dem Konzept einer GPU-zentrierten Visualisierungspipeline, in welcher alle Stufen -- Prozessierung,Mapping, Rendering -- auf der GPU ausgef{\"u}hrt werden. Bei diesem Konzept werden die r{\"a}umlich-zeitlichen Daten direkt im GPU-Speicher abgelegt. W{\"a}hrend des Rendering-Prozesses werden dann mittels Shader-Programmen die Daten prozessiert, gefiltert, ein Mapping auf visuelle Attribute vorgenommen, und schließlich die Geometrien f{\"u}r die Visualisierung erzeugt. Datenprozessierung, Filtering und Mapping k{\"o}nnen daher in Echtzeit ausgef{\"u}hrt werden. Dies erm{\"o}glicht es Usern, die Mapping-Parameter sowie den gesamten Visualisierungsprozess interaktiv zu steuern und zu kontrollieren. - Interaktive Visualisierung attributierter 3D-Trajektorien. Es wurde eine Visualisierungsmethode f{\"u}r die interaktive Exploration einer großen Anzahl von 3D Bewegungstrajektorien entwickelt. Die Trajektorien werden dabei innerhalb einer virtuellen geographischen Umgebung in Form von einfachen Geometrien, wie Linien, B{\"a}ndern, Kugeln oder R{\"o}hren dargestellt. Durch interaktives Mapping k{\"o}nnen Attributwerte der Trajektorien oder einzelner Messpunkte auf visuelle Eigenschaften abgebildet werden. Hierzu stehen Form, H{\"o}he, Gr{\"o}ße, Farbe, Textur, sowie Animation zur Verf{\"u}gung. Mithilfe dieses dynamischen Mappings wurden außerdem verschiedene Visualisierungsmethoden implementiert, wie z.B. eine Focus+Context-Visualisierung von Trajektorien mithilfe von interaktiven Dichtekarten, sowie einer Space-Time-Cube-Visualisierung zur Darstellung des zeitlichen Ablaufs einzelner Bewegungen. - Interaktive Visualisierung geographischer Netzwerke. Es wurde eine Visualisierungsmethode zur interaktiven Exploration geo-referenzierter Netzwerke entwickelt, welche die Visualisierung von Netzwerken mit einer großen Anzahl von Knoten und Kanten erm{\"o}glicht. Um die Analyse von Netzwerken verschiedener Gr{\"o}ßen und in unterschiedlichen Kontexten zu erm{\"o}glichen, stehen mehrere virtuelle geographische Umgebungen zur Verf{\"u}gung, wie bspw. ein virtueller 3D-Globus, als auch 2D-Karten mit unterschiedlichen geographischen Projektionen. Zur interaktiven Analyse dieser Netzwerke stehen interaktive Tools wie Filterung, Mapping und Selektion zur Verf{\"u}gung. Des weiteren wurden Visualisierungsmethoden f{\"u}r verschiedene Arten von Netzwerken, wie z.B. 3D-Netzwerke und zeitlich ver{\"a}nderliche Netzwerke, implementiert. Zur Demonstration des Konzeptes wurden interaktive Tools f{\"u}r zwei unterschiedliche Anwendungsf{\"a}lle entwickelt. Das erste beinhaltet die Visualisierung attributierter 3D-Trajektorien, welche die Bewegungen von Flugzeugen um einen Flughafen beschreiben. Es erm{\"o}glicht Nutzern, die Trajektorien von ankommenden und startenden Flugzeugen {\"u}ber den Zeitraum eines Monats interaktiv zu explorieren und zu analysieren. Durch Verwendung der interaktiven Visualisierungsmethoden f{\"u}r 3D-Trajektorien und interaktiven Dichtekarten k{\"o}nnen Einblicke in die Daten gewonnen werden, wie beispielsweise h{\"a}ufig genutzte Flugkorridore, typische sowie untypische Bewegungsmuster, oder ungew{\"o}hnliche Vorkommnisse wie Fehlanfl{\"u}ge. Der zweite Anwendungsfall beinhaltet die Visualisierung von Klimanetzwerken, welche geographischen Netzwerken in der Klimaforschung darstellen. Klimanetzwerke repr{\"a}sentieren die Dynamiken im Klimasystem durch eine Netzwerkstruktur, die die statistische Beziehungen zwischen Orten beschreiben. Das entwickelte Tool erm{\"o}glicht es Analysten, diese großen Netzwerke interaktiv zu explorieren und dadurch die Struktur des Netzwerks zu analysieren und mit den geographischen Daten in Beziehung zu setzen. Interaktive Filterung und Selektion erm{\"o}glichen es, Muster in den Daten zu identifizieren, und so bspw. Cluster in der Netzwerkstruktur oder Str{\"o}mungsmuster zu erkennen.},
  language  = {en}
}
@phdthesis{VillatoroLeal2018,
  author    = {Villatoro Leal, Jos{\´e} Andr{\´e}s},
  title     = {A combined approach for the analysis of biomolecules using IR-MALDI ion mobility spectrometry and molecular dynamics simulations of peptide ions in the gas phase},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419723},
  school      = {Universit{\"a}t Potsdam},
  pages     = {133},
  year      = {2018},
  abstract  = {The aim of this doctoral thesis was to establish a technique for the analysis of biomolecules with infrared matrix-assisted laser dispersion (IR-MALDI) ion mobility (IM) spectrometry. The main components of the work were the characterization of the IR-MALDI process, the development and characterization of different ion mobility spectrometers, the use of IR-MALDI-IM spectrometry as a robust, standalone spectrometer and the development of a collision cross-section estimation approach for peptides based on molecular dynamics and thermodynamic reweighting. First, the IR-MALDI source was studied with atmospheric pressure ion mobility spectrometry and shadowgraphy. It consisted of a metal capillary, at the tip of which a self-renewing droplet of analyte solution was met by an IR laser beam. A relationship between peak shape, ion desolvation, diffusion and extraction pulse delay time (pulse delay) was established. First order desolvation kinetics were observed and related to peak broadening by diffusion, both influenced by the pulse delay. The transport mechanisms in IR-MALDI were then studied by relating different laser impact positions on the droplet surface to the corresponding ion mobility spectra. Two different transport mechanisms were determined: phase explosion due to the laser pulse and electrical transport due to delayed ion extraction. The velocity of the ions stemming from the phase explosion was then measured by ion mobility and shadowgraphy at different time scales and distances from the source capillary, showing an initially very high but rapidly decaying velocity. Finally, the anatomy of the dispersion plume was observed in detail with shadowgraphy and general conclusions over the process were drawn. Understanding the IR-MALDI process enabled the optimization of the different IM spectrometers at atmospheric and reduced pressure (AP and RP, respectively). At reduced pressure, both an AP and an RP IR-MALDI source were used. The influence of the pulsed ion extraction parameters (pulse delay, width and amplitude) on peak shape, resolution and area was systematically studied in both AP and RP IM spectrometers and discussed in the context of the IR-MALDI process. Under RP conditions, the influence of the closing field and of the pressure was also examined for both AP and RP sources. For the AP ionization RP IM spectrometer, the influence of the inlet field (IF) in the source region was also examined. All of these studies led to the determination of the optimal analytical parameters as well as to a better understanding of the initial ion cloud anatomy. The analytical performance of the spectrometer was then studied. Limits of detection (LOD) and linear ranges were determined under static and pulsed ion injection conditions and interpreted in the context of the IR-MALDI mechanism. Applications in the separation of simple mixtures were also illustrated, demonstrating good isomer separation capabilities and the advantages of singly charged peaks. The possibility to couple high performance liquid chromatography (HPLC) to IR-MALDI-IM spectrometry was also demonstrated. Finally, the reduced pressure spectrometer was used to study the effect of high reduced field strength on the mobility of polyatomic ions in polyatomic gases. The last focus point was on the study of peptide ions. A dataset obtained with electrospray IM spectrometry was characterized and used for the calibration of a collision cross-section (CCS) determination method based on molecular dynamics (MD) simulations at high temperature. Instead of producing candidate structures which are evaluated one by one, this semi-automated method uses the simulation as a whole to determine a single average collision cross-section value by reweighting the CCS of a few representative structures. The method was compared to the intrinsic size parameter (ISP) method and to experimental results. Additional MD data obtained from the simulations was also used to further analyze the peptides and understand the experimental results, an advantage with regard to the ISP method. Finally, the CCS of peptide ions analyzed by IR-MALDI were also evaluated with both ISP and MD methods and the results compared to experiment, resulting in a first validation of the MD method. Thus, this thesis brings together the soft ionization technique that is IR-MALDI, which produces mostly singly charged peaks, with ion mobility spectrometry, which can distinguish between isomers, and a collision cross-section determination method which also provides structural information on the analyte at hand.},
  language  = {en}
}
@phdthesis{Engelhardt2018,
  author    = {Engelhardt, Jonathan},
  title     = {40Ar/39Ar geochronology of ICDP PALEOVAN drilling cores},
  doi       = {10.25932/publishup-42953},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-429539},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxi, 338},
  year      = {2018},
  abstract  = {The scientific drilling campaign PALEOVAN was conducted in the summer of 2010 and was part of the international continental drilling programme (ICDP). The main goal of the campaign was the recovery of a sensitive climate archive in the East of Anatolia. Lacustrine deposits underneath the lake floor of 'Lake Van' constitute this archive. The drilled core material was recovered from two locations: the Ahlat Ridge and the Northern Basin. A composite core was constructed from cored material of seven parallel boreholes at the Ahlat Ridge and covers an almost complete lacustrine history of Lake Van. The composite record offered sensitive climate proxies such as variations of total organic carbon, K/Ca ratios, or a relative abundance of arboreal pollen. These proxies revealed patterns that are similar to climate proxy variations from Greenland ice cores. Climate variations in Greenland ice cores have been dated by modelling the timing of orbital forces to affect the climate. Volatiles from melted ice aliquots are often taken as high-resolution proxies and provide a base for fitting the according temporal models. The ICDP PALEOVAN scientific team fitted proxy data from the lacustrine drilling record to ice core data and constructed an age model. Embedded volcaniclastic layers had to be dated radiometrically in order to provide independent age constraints to the climate-stratigraphic age model. Solving this task by an application of the 40Ar/39Ar method was the main objective of this thesis. Earlier efforts to apply the 40Ar/39Ar dating resulted in inaccuracies that could not be explained satisfactorily. The absence of K-rich feldspars in suitable tephra layers implied that feldspar crystals needed to be 500 μm in size minimum, in order to apply single-crystal 40Ar/39Ar dating. Some of the samples did not contain any of these grain sizes or only very few crystals of that size. In order to overcome this problem this study applied a combined single-crystal and multi-crystal approach with different crystal fractions from the same sample. The preferred method of a stepwise heating analysis of an aliquot of feldspar crystals has been applied to three samples. The Na-rich crystals and their young geological age required 20 mg of inclusion-free, non-corroded feldspars. Small sample volumes (usually 25 \% aliquots of 5 cm3 of sample material - a spoon full of tephra) and the widespread presence of melt-inclusion led to the application of combined single- and multigrain total fusion analyses. 40Ar/39Ar analyses on single crystals have the advantage of being able to monitor the presence of excess 40Ar and detrital or xenocrystic contamination in the samples. Multigrain analyses may hide the effects from these obstacles. The results from the multigrain analyses are therefore discussed with respect to the findings from the respective cogenetic single crystal ages. Some of the samples in this study were dated by 40Ar/39Ar on feldspars on multigrain separates and (if available) in combination with only a few single crystals. 40Ar/39Ar ages from two of the samples deviated statistically from the age model. All other samples resulted in identical ages. The deviations displayed older ages than those obtained from the age model. t-Tests compared radiometric ages with available age control points from various proxies and from the relative paleointensity of the earth magnetic field within a stratigraphic range of ± 10 m. Concordant age control points from different relative chronometers indicated that deviations are a result of erroneous 40Ar/39Ar ages. The thesis argues two potential reasons for these ages: (1) the irregular appearance of 40Ar from rare melt- and fluid- inclusions and (2) the contamination of the samples with older crystals due to a rapid combination of assimilation and ejection. Another aliquot of feldspar crystals that underwent separation for the application of 40Ar/39Ar dating was investigated for geochemical inhomogeneities. Magmatic zoning is ubiquitous in the volcaniclastic feldspar crystals. Four different types of magmatic zoning were detected. The zoning types are compositional zoning (C-type zoning), pseudo-oscillatory zoning of trace ele- ment concentrations (PO-type zoning), chaotic and patchy zoning of major and trace element concentrations (R-type zoning) and concentric zoning of trace elements (CC-type zoning). Sam- ples that deviated in 40Ar/39Ar ages showed C-type zoning, R-type zoning or a mix of different types of zoning (C-type and PO-type). Feldspars showing PO-type zoning typically represent the smallest grain size fractions in the samples. The constant major element compositions of these crystals are interpreted to represent the latest stages in the compositional evolution of feldspars in a peralkaline melt. PO-type crystals contain less melt- inclusions than other zoning types and are rarely corroded. This thesis concludes that feldspars that show PO-type zoning are most promising chronometers for the 40Ar/39Ar method, if samples provide mixed zoning types of Quaternary anorthoclase feldspars. Five samples were dated by applying the 40Ar/39Ar method to volcanic glass. High fractions of atmospheric Ar (typically > 98\%) significantly hampered the precision of the 40Ar/39Ar ages and resulted in rough age estimates that widely overlap the age model. Ar isotopes indicated that the glasses bore a chorine-rich Ar-end member. The chlorine-derived 38Ar indicated chlorine-rich fluid-inclusions or the hydration of the volcanic glass shards. This indication strengthened the evidence that irregularly distributed melt-inclusions and thus irregular distributed excess 40Ar influenced the problematic feldspar 40Ar/39Ar ages. Whether a connection between a corrected initial 40Ar/36Ar ratio from glasses to the 40Ar/36Ar ratios from pore waters exists remains unclear. This thesis offers another age model, which is similarly based on the interpolation of the temporal tie points from geophysical and climate-stratigraphic data. The model used a PCHIP- interpolation (piecewise cubic hermite interpolating polynomial) whereas the older age model used a spline-interpolation. Samples that match in ages from 40Ar/39Ar dating of feldspars with the earlier published age model were additionally assigned with an age from the PCHIP- interpolation. These modelled ages allowed a recalculation of the Alder Creek sanidine mineral standard. The climate-stratigraphic calibration of an 40Ar/39Ar mineral standard proved that the age versus depth interpolations from PAELOVAN drilling cores were accurate, and that the applied chronometers recorded the temporal evolution of Lake Van synchronously. Petrochemical discrimination of the sampled volcaniclastic material is also given in this thesis. 41 from 57 sampled volcaniclastic layers indicate Nemrut as their provenance. Criteria that served for the provenance assignment are provided and reviewed critically. Detailed correlations of selected PALEOVAN volcaniclastics to onshore samples that were described in detail by earlier studies are also discussed. The sampled volcaniclastics dominantly have a thickness of < 40 cm and have been ejected by small to medium sized eruptions. Onshore deposits from these types of eruptions are potentially eroded due to predominant strong winds on Nemrut and S{\"u}phan slopes. An exact correlation with the data presented here is therefore equivocal or not possible at all. Deviating feldspar 40Ar/39Ar ages can possibly be explained by inherited 40Ar from feldspar xenocrysts contaminating the samples. In order to test this hypothesis diffusion couples of Ba were investigated in compositionally zoned feldspar crystals. The diffusive behaviour of Ba in feldspar is known, and gradients in the changing concentrations allowed for the calculation of the duration of the crystal's magmatic development since the formation of the zoning interface. Durations were compared with degassing scenarios that model the Ar-loss during assimilation and subsequent ejection of the xenocrystals. Diffusive equilibration of the contrasting Ba concentrations is assumed to generate maximum durations as the gradient could have been developed in several growth and heating stages. The modelling does not show any indication of an involvement of inherited 40Ar in any of the deviating samples. However, the analytical set-up represents the lower limit of the required spatial resolution. Therefore, it cannot be excluded that the degassing modelling relies on a significant overestimation of the maximum duration of the magmatic history. Nevertheless, the modelling of xenocrystal degassing evidences that the irregular incorporation of excess 40Ar by melt- and fluid inclusions represents the most critical problem that needs to be overcome in dating volcaniclastic feldspars from the PALEOVAN drill cores. This thesis provides the complete background in generating and presenting 40Ar/39Ar ages that are compared to age data from a climate-stratigraphic model. Deviations are identified statistically and then discussed in order to find explanations from the age model and/or from 40Ar/39Ar geochronology. Most of the PALEOVAN stratigraphy provides several chronometers that have been proven for their synchronicity. Lacustrine deposits from Lake Van represent a key archive for reconstructing climate evolution in the eastern Mediterranean and in the Near East. The PALEOVAN record offers a climate-stratigraphic age model with a remarkable accuracy and resolution.},
  language  = {en}
}