@phdthesis{Ziese2014,
  author    = {Ziese, Ramona},
  title     = {Geometric electroelasticity},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72504},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vi, 113},
  year      = {2014},
  abstract  = {In this work a diffential geometric formulation of the theory of electroelasticity is developed which also includes thermal and magnetic influences. We study the motion of bodies consisting of an elastic material that are deformed by the influence of mechanical forces, heat and an external electromagnetic field. To this end physical balance laws (conservation of mass, balance of momentum, angular momentum and energy) are established. These provide an equation that describes the motion of the body during the deformation. Here the body and the surrounding space are modeled as Riemannian manifolds, and we allow that the body has a lower dimension than the surrounding space. In this way one is not (as usual) restricted to the description of the deformation of three-dimensional bodies in a three-dimensional space, but one can also describe the deformation of membranes and the deformation in a curved space. Moreover, we formulate so-called constitutive relations that encode the properties of the used material. Balance of energy as a scalar law can easily be formulated on a Riemannian manifold. The remaining balance laws are then obtained by demanding that balance of energy is invariant under the action of arbitrary diffeomorphisms on the surrounding space. This generalizes a result by Marsden and Hughes that pertains to bodies that have the same dimension as the surrounding space and does not allow the presence of electromagnetic fields. Usually, in works on electroelasticity the entropy inequality is used to decide which otherwise allowed deformations are physically admissible and which are not. It is alsoemployed to derive restrictions to the possible forms of constitutive relations describing the material. Unfortunately, the opinions on the physically correct statement of the entropy inequality diverge when electromagnetic fields are present. Moreover, it is unclear how to formulate the entropy inequality in the case of a membrane that is subjected to an electromagnetic field. Thus, we show that one can replace the use of the entropy inequality by the demand that for a given process balance of energy is invariant under the action of arbitrary diffeomorphisms on the surrounding space and under linear rescalings of the temperature. On the one hand, this demand also yields the desired restrictions to the form of the constitutive relations. On the other hand, it needs much weaker assumptions than the arguments in physics literature that are employing the entropy inequality. Again, our result generalizes a theorem of Marsden and Hughes. This time, our result is, like theirs, only valid for bodies that have the same dimension as the surrounding space.},
  language  = {en}
}
@phdthesis{Yeldesbay2014,
  author    = {Yeldesbay, Azamat},
  title     = {Complex regimes of synchronization},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-73348},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ii, 60},
  year      = {2014},
  abstract  = {Synchronization is a fundamental phenomenon in nature. It can be considered as a general property of self-sustained oscillators to adjust their rhythm in the presence of an interaction. In this work we investigate complex regimes of synchronization phenomena by means of theoretical analysis, numerical modeling, as well as practical analysis of experimental data. As a subject of our investigation we consider chimera state, where due to spontaneous symmetry-breaking of an initially homogeneous oscillators lattice split the system into two parts with different dynamics. Chimera state as a new synchronization phenomenon was first found in non-locally coupled oscillators system, and has attracted a lot of attention in the last decade. However, the recent studies indicate that this state is also possible in globally coupled systems. In the first part of this work, we show under which conditions the chimera-like state appears in a system of globally coupled identical oscillators with intrinsic delayed feedback. The results of the research explain how initially monostable oscillators became effectivly bistable in the presence of the coupling and create a mean field that sustain the coexistence of synchronized and desynchronized states. Also we discuss other examples, where chimera-like state appears due to frequency dependence of the phase shift in the bistable system. In the second part, we make further investigation of this topic by modeling influence of an external periodic force to an oscillator with intrinsic delayed feedback. We made stability analysis of the synchronized state and constructed Arnold tongues. The results explain formation of the chimera-like state and hysteric behavior of the synchronization area. Also, we consider two sets of parameters of the oscillator with symmetric and asymmetric Arnold tongues, that correspond to mono- and bi-stable regimes of the oscillator. In the third part, we demonstrate the results of the work, which was done in collaboration with our colleagues from Psychology Department of University of Potsdam. The project aimed to study the effect of the cardiac rhythm on human perception of time using synchronization analysis. From our part, we made a statistical analysis of the data obtained from the conducted experiment on free time interval reproduction task. We examined how ones heartbeat influences the time perception and searched for possible phase synchronization between heartbeat cycles and time reproduction responses. The findings support the prediction that cardiac cycles can serve as input signals, and is used for reproduction of time intervals in the range of several seconds.},
  language  = {en}
}
@phdthesis{Yadavalli2014,
  author    = {Yadavalli, Nataraja Sekhar},
  title     = {Advances in experimental methods to probe surface relief grating formation mechanism in photosensitive materials},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71213},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {When azobenzene-modified photosensitive polymer films are irradiated with light interference patterns, topographic variations in the film develop that follow the electric field vector distribution resulting in the formation of surface relief grating (SRG). The exact correspondence of the electric field vector orientation in interference pattern in relation to the presence of local topographic minima or maxima of SRG is in general difficult to determine. In my thesis, we have established a systematic procedure to accomplish the correlation between different interference patterns and the topography of SRG. For this, we devise a new setup combining an atomic force microscope and a two-beam interferometer (IIAFM). With this set-up, it is possible to track the topography change in-situ, while at the same time changing polarization and phase of the impinging interference pattern. To validate our results, we have compared two photosensitive materials named in short as PAZO and trimer. This is the first time that an absolute correspondence between the local distribution of electric field vectors of interference pattern and the local topography of the relief grating could be established exhaustively. In addition, using our IIAFM we found that for a certain polarization combination of two orthogonally polarized interfering beams namely SP (↕, ↔) interference pattern, the topography forms SRG with only half the period of the interference patterns. Exploiting this phenomenon we are able to fabricate surface relief structures below diffraction limit with characteristic features measuring only 140 nm, by using far field optics with a wavelength of 491 nm. We have also probed for the stresses induced during the polymer mass transport by placing an ultra-thin gold film on top (5-30 nm). During irradiation, the metal film not only deforms along with the SRG formation, but ruptures in regular and complex manner. The morphology of the cracks differs strongly depending on the electric field distribution in the interference pattern even when the magnitude and the kinetic of the strain are kept constant. This implies a complex local distribution of the opto-mechanical stress along the topography grating. The neutron reflectivity measurements of the metal/polymer interface indicate the penetration of metal layer within the polymer resulting in the formation of bonding layer that confirms the transduction of light induced stresses in the polymer layer to a metal film.},
  language  = {en}
}
@phdthesis{Wunderlich2014,
  author    = {Wunderlich, Kai},
  title     = {Entwicklung einer parallelen Mehrkomponentenanalyse von Antigen-Antik{\"o}rper-Reaktionen in der Dopinganalyse},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-76869},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VIII, 130},
  year      = {2014},
  abstract  = {Weltweit streben Anti-Doping Institute danach jene Sportler zu {\"u}berf{\"u}hren, welche sich unerlaubter Mittel oder Methoden bedienen. Die hierf{\"u}r notwendigen Testsysteme werden kontinuierlich weiterentwickelt und neue Methoden aufgrund neuer Wirkstoffe der Pharmaindustrie etabliert. Gegenstand dieser Arbeit war es, eine parallele Mehrkomponentenanalyse auf Basis von Antigen-Antik{\"o}rper Reaktionen zu entwickeln, bei dem es prim{\"a}r um Verringerung des ben{\"o}tigten Probevolumens und der Versuchszeit im Vergleich zu einem Standard Nachweis-Verfahren ging. Neben der Verwendung eines Multiplex Ansatzes und der Mikroarraytechnologie stellten ebenfalls die Genauigkeit aller Messparameter, die Stabilit{\"a}t des Versuchsaufbaus sowie die Performance {\"u}ber einen Einfach-Blind-Ansatz Herausforderungen dar. Die Anforderung an den Multiplex Ansatz, keine falschen Signale trotz {\"a}hnlicher Strukturen zu messen, konnte durch die gezielte Kombination von spezifischen Antik{\"o}rpern realisiert werden. Hierf{\"u}r wurden neben Kreuzreaktivit{\"a}tstests auf dem Mikroarray parallel erfolgreich Western Blot Versuche durchgef{\"u}hrt. Jene Antik{\"o}rper, welche in diesen Versuchen die gesetzten Anforderungen erf{\"u}llten, wurden f{\"u}r das Ermitteln der kleinsten nachweisbaren Konzentration verwendet. {\"U}ber das Optimieren der Versuchsbedingungen konnte unter Verwendung von Tween in der Waschl{\"o}sung sowohl auf Glas als auch auf Kunststoff die Hintergrundfluoreszenz reduziert und somit eine Steigerung des Signal/Hintergrundverh{\"a}ltnisses erreicht werden. In den Versuchen zu Ermittlung der Bestimmungsgrenze wurde f{\"u}r das humane Choriongonadotropin (hCG-i) eine Konzentration von 10 mU/ml, f{\"u}r dessen beta-Untereinheit (hCG-beta) eine Konzentration von 3,6 mU/ml und f{\"u}r das luteinisierende Hormon (LH) eine Konzentration von 10 mU/ml bestimmt. Den ermittelten Wert im Serum f{\"u}r das hCG-i entspricht dem von der Welt-Anti-Dopin-Agentur (WADA) geforderten Wert in Urin von 5 mU/ml. Neben der Ermittlung von Bestimmungsgrenzen wurden diese hinsichtlich auftretender Matrixeffekte in Serum und Blut gemessen. Wie aus den Versuchen zur Ermittlung von Kreuzreaktivit{\"a}ten auf dem Mikroarray zu entnehmen ist, lassen sich das LH, das hCG-i und hCG-β ebenfalls in Serum und Blut messen. Die Durchf{\"u}hrung einer Performance-Analyse {\"u}ber einem Einfach-Blind-Ansatz mit 130 Serum Proben, wurde ebenfalls {\"u}ber dieses System realisiert. Die ausgewerteten Proben wurden anschließend {\"u}ber eine Grenzwertoptimierungskurve analysiert und die diagnostische Spezifit{\"a}t ermittelt. F{\"u}r die Messungen des LH konnte eine Sensitivit{\"a}t und Spezifit{\"a}t von 100\% erreicht werden. Demnach wurden alle negativen und positiven Proben eindeutig interpretiert. F{\"u}r das hCG-β konnte ebenfalls eine Spezifit{\"a}t von 100\% und eine Sensitivit{\"a}t von 97\% erreicht werden. Die hCG-i Proben wurden mit einer Spezifit{\"a}t von 100\% und eine Sensitivit{\"a}t von 97,5\% gemessen. Um den Nachweis zu erbringen, dass dieser Versuchsaufbau {\"u}ber mehrere Wochen stabile Signale bei Vermessen von identischen Proben liefert, wurde ein {\"u}ber zw{\"o}lf Wochen angesetzter Stabilit{\"a}tstest f{\"u}r alle Parameter erfolgreich in Serum und Blut durchgef{\"u}hrt. Zusammenfassend konnte in dieser Arbeit erfolgreich eine Mehrkomponentenanalyse als Multiplex Ansatz auf einem Mikroarray entwickelt werden. Die Durchf{\"u}hrung der Performance-Analyse und des Stabilit{\"a}tstests zeigen bereits die m{\"o}gliche Einsatzf{\"a}higkeit dieses Tests im Kontext einer Dopinganalyse.},
  language  = {de}
}
@phdthesis{Wilde2014,
  author    = {Wilde, Anja},
  title     = {Auspr{\"a}gungen r{\"a}umlicher Identit{\"a}t in ehemaligen sudetendeutschen Gebieten der Tschechischen Republik},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-311-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-70247},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XVI, 395},
  year      = {2014},
  abstract  = {Das tschechische Grenzgebiet ist eine der Regionen in Europa, die in der Folge des Zweiten Weltkrieges am gravierendsten von Umbr{\"u}chen in der zuvor bestehenden Bev{\"o}lkerungsstruktur betroffen waren. Der erzwungenen Aussiedlung eines Großteils der ans{\"a}ssigen Bev{\"o}lkerung folgten die Neubesiedlung durch verschiedenste Zuwanderergruppen sowie teilweise langanhaltende Fluktuationen der Einwohnerschaft. Die Stabilisierung der Bev{\"o}lkerung stand sodann unter dem Zeichen der sozialistischen Gesellschafts- und Wirtschaftsordnung, die die Lebensweise und Raumwahrnehmung der neuen Einwohner nachhaltig pr{\"a}gte. Die Grenz{\"o}ffnung von 1989, die politische Transformation sowie die Integration der Tschechischen Republik in die Europ{\"a}ische Union brachten neue demographische und sozio{\"o}konomische Entwicklungen mit sich. Sie schufen aber auch die Bedingungen daf{\"u}r, sich neu und offen auch mit der spezifischen Geschichte des ehemaligen Sudetenlandes sowie mit dem Zustand der gegenw{\"a}rtigen Gesellschaft in diesem Gebiet auseinanderzusetzen. Im Rahmen der vorliegenden Arbeit wird anhand zweier Beispielregionen untersucht, welche Raumvorstellungen und Raumbindungen bei der heute in den ehemaligen sudetendeutschen Gebieten ans{\"a}ssigen Bev{\"o}lkerung vorhanden sind und welche Einfl{\"u}sse die unterschiedlichen raumstrukturellen Bedingungen darauf aus{\"u}ben. Besonderes Augenmerk wird auf die soziale Komponente der Auspr{\"a}gung r{\"a}umlicher Identit{\"a}t gelegt, das heißt auf die Rolle von Bedeutungszuweisungen gegen{\"u}ber Raumelementen im Rahmen sozialer Kommunikation und Interaktion. Dies erscheint von besonderer Relevanz in einem Raum, der sich durch eine gewisse Heterogenit{\"a}t seiner Einwohnerschaft hinsichtlich ihres ethnischen, kulturellen beziehungsweise biographischen Hintergrundes auszeichnet. Schließlich wird ermittelt, welche Impulse unter Umst{\"a}nden von einer ausgepr{\"a}gten r{\"a}umlichen Identit{\"a}t f{\"u}r die Entwicklung des Raumes ausgehen.},
  language  = {de}
}
@phdthesis{Widdrat2014,
  author    = {Widdrat, Marc},
  title     = {Formation and alteration of magnetite nanoparticles},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-72239},
  school      = {Universit{\"a}t Potsdam},
  pages     = {113},
  year      = {2014},
  abstract  = {Magnetite is an iron oxide, which is ubiquitous in rocks and is usually deposited as small nanoparticulate matter among other rock material. It differs from most other iron oxides because it contains divalent and trivalent iron. Consequently, it has a special crystal structure and unique magnetic properties. These properties are used for paleoclimatic reconstructions where naturally occurring magnetite helps understanding former geological ages. Further on, magnetic properties are used in bio- and nanotechnological applications -synthetic magnetite serves as a contrast agent in MRI, is exploited in biosensing, hyperthermia or is used in storage media. Magnetic properties are strongly size-dependent and achieving size control under preferably mild synthesis conditions is of interest in order to obtain particles with required properties. By using a custom-made setup, it was possible to synthesize stable single domain magnetite nanoparticles with the co-precipitation method. Furthermore, it was shown that magnetite formation is temperature-dependent, resulting in larger particles at higher temperatures. However, mechanistic approaches about the details are incomplete. Formation of magnetite from solution was shown to occur from nanoparticulate matter rather than solvated ions. The theoretical framework of such processes has only started to be described, partly due to the lack of kinetic or thermodynamic data. Synthesis of magnetite nanoparticles at different temperatures was performed and the Arrhenius plot was used determine an activation energy for crystal growth of 28.4 kJ mol-1, which led to the conclusion that nanoparticle diffusion is the rate-determining step. Furthermore, a study of the alteration of magnetite particles of different sizes as a function of their storage conditions is presented. The magnetic properties depend not only on particle size but also depend on the structure of the oxide, because magnetite oxidizes to maghemite under environmental conditions. The dynamics of this process have not been well described. Smaller nanoparticles are shown to oxidize more rapidly than larger ones and the lower the storage temperature, the lower the measured oxidation. In addition, the magnetic properties of the altered particles are not decreased dramatically, thus suggesting that this alteration will not impact the use of such nanoparticles as medical carriers. Finally, the effect of biological additives on magnetite formation was investigated. Magnetotactic bacteria¬¬ are able to synthesize and align magnetite nanoparticles of well-defined size and morphology due to the involvement of special proteins with specific binding properties. Based on this model of morphology control, phage display experiments were performed to determine peptide sequences that preferably bind to (111)-magnetite faces. The aim was to control the shape of magnetite nanoparticles during the formation. Magnetotactic bacteria are also able to control the intracellular redox potential with proteins called magnetochromes. MamP is such a protein and its oxidizing nature was studied in vitro via biomimetic magnetite formation experiments based on ferrous ions. Magnetite and further trivalent oxides were found. This work helps understanding basic mechanisms of magnetite formation and gives insight into non-classical crystal growth. In addition, it is shown that alteration of magnetite nanoparticles is mainly based on oxidation to maghemite and does not significantly influence the magnetic properties. Finally, biomimetic experiments help understanding the role of MamP within the bacteria and furthermore, a first step was performed to achieve morphology control in magnetite formation via co-precipitation.},
  language  = {en}
}
@phdthesis{Vu2014,
  author    = {Vu, Dinh Phuong},
  title     = {Using video study to investigate eighth-grade mathematics classrooms in Vietnam},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72464},
  school      = {Universit{\"a}t Potsdam},
  pages     = {273},
  year      = {2014},
  abstract  = {The International Project for the Evaluation of Educational Achievement (IEA) was formed in the 1950s (Postlethwaite, 1967). Since that time, the IEA has conducted many studies in the area of mathematics, such as the First International Mathematics Study (FIMS) in 1964, the Second International Mathematics Study (SIMS) in 1980-1982, and a series of studies beginning with the Third International Mathematics and Science Study (TIMSS) which has been conducted every 4 years since 1995. According to Stigler et al. (1999), in the FIMS and the SIMS, U.S. students achieved low scores in comparison with students in other countries (p. 1). The TIMSS 1995 "Videotape Classroom Study" was therefore a complement to the earlier studies conducted to learn "more about the instructional and cultural processes that are associated with achievement" (Stigler et al., 1999, p. 1). The TIMSS Videotape Classroom Study is known today as the TIMSS Video Study. From the findings of the TIMSS 1995 Video Study, Stigler and Hiebert (1999) likened teaching to "mountain ranges poking above the surface of the water," whereby they implied that we might see the mountaintops, but we do not see the hidden parts underneath these mountain ranges (pp. 73-78). By watching the videotaped lessons from Germany, Japan, and the United States again and again, they discovered that "the systems of teaching within each country look similar from lesson to lesson. At least, there are certain recurring features [or patterns] that typify many of the lessons within a country and distinguish the lessons among countries" (pp. 77-78). They also discovered that "teaching is a cultural activity," so the systems of teaching "must be understood in relation to the cultural beliefs and assumptions that surround them" (pp. 85, 88). From this viewpoint, one of the purposes of this dissertation was to study some cultural aspects of mathematics teaching and relate the results to mathematics teaching and learning in Vietnam. Another research purpose was to carry out a video study in Vietnam to find out the characteristics of Vietnamese mathematics teaching and compare these characteristics with those of other countries. In particular, this dissertation carried out the following research tasks: - Studying the characteristics of teaching and learning in different cultures and relating the results to mathematics teaching and learning in Vietnam - Introducing the TIMSS, the TIMSS Video Study and the advantages of using video study in investigating mathematics teaching and learning - Carrying out the video study in Vietnam to identify the image, scripts and patterns, and the lesson signature of eighth-grade mathematics teaching in Vietnam - Comparing some aspects of mathematics teaching in Vietnam and other countries and identifying the similarities and differences across countries - Studying the demands and challenges of innovating mathematics teaching methods in Vietnam - lessons from the video studies Hopefully, this dissertation will be a useful reference material for pre-service teachers at education universities to understand the nature of teaching and develop their teaching career.},
  language  = {en}
}
@phdthesis{Videla2014,
  author    = {Videla, Santiago},
  title     = {Reasoning on the response of logical signaling networks with answer set programming},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71890},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Deciphering the functioning of biological networks is one of the central tasks in systems biology. In particular, signal transduction networks are crucial for the understanding of the cellular response to external and internal perturbations. Importantly, in order to cope with the complexity of these networks, mathematical and computational modeling is required. We propose a computational modeling framework in order to achieve more robust discoveries in the context of logical signaling networks. More precisely, we focus on modeling the response of logical signaling networks by means of automated reasoning using Answer Set Programming (ASP). ASP provides a declarative language for modeling various knowledge representation and reasoning problems. Moreover, available ASP solvers provide several reasoning modes for assessing the multitude of answer sets. Therefore, leveraging its rich modeling language and its highly efficient solving capacities, we use ASP to address three challenging problems in the context of logical signaling networks: learning of (Boolean) logical networks, experimental design, and identification of intervention strategies. Overall, the contribution of this thesis is three-fold. Firstly, we introduce a mathematical framework for characterizing and reasoning on the response of logical signaling networks. Secondly, we contribute to a growing list of successful applications of ASP in systems biology. Thirdly, we present a software providing a complete pipeline for automated reasoning on the response of logical signaling networks.},
  language  = {en}
}
@phdthesis{Truemper2014,
  author    = {Tr{\"u}mper, Jonas},
  title     = {Visualization techniques for the analysis of software behavior and related structures},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72145},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Software maintenance encompasses any changes made to a software system after its initial deployment and is thereby one of the key phases in the typical software-engineering lifecycle. In software maintenance, we primarily need to understand structural and behavioral aspects, which are difficult to obtain, e.g., by code reading. Software analysis is therefore a vital tool for maintaining these systems: It provides - the preferably automated - means to extract and evaluate information from their artifacts such as software structure, runtime behavior, and related processes. However, such analysis typically results in massive raw data, so that even experienced engineers face difficulties directly examining, assessing, and understanding these data. Among other things, they require tools with which to explore the data if no clear question can be formulated beforehand. For this, software analysis and visualization provide its users with powerful interactive means. These enable the automation of tasks and, particularly, the acquisition of valuable and actionable insights into the raw data. For instance, one means for exploring runtime behavior is trace visualization. This thesis aims at extending and improving the tool set for visual software analysis by concentrating on several open challenges in the fields of dynamic and static analysis of software systems. This work develops a series of concepts and tools for the exploratory visualization of the respective data to support users in finding and retrieving information on the system artifacts concerned. This is a difficult task, due to the lack of appropriate visualization metaphors; in particular, the visualization of complex runtime behavior poses various questions and challenges of both a technical and conceptual nature. This work focuses on a set of visualization techniques for visually representing control-flow related aspects of software traces from shared-memory software systems: A trace-visualization concept based on icicle plots aids in understanding both single-threaded as well as multi-threaded runtime behavior on the function level. The concept's extensibility further allows the visualization and analysis of specific aspects of multi-threading such as synchronization, the correlation of such traces with data from static software analysis, and a comparison between traces. Moreover, complementary techniques for simultaneously analyzing system structures and the evolution of related attributes are proposed. These aim at facilitating long-term planning of software architecture and supporting management decisions in software projects by extensions to the circular-bundle-view technique: An extension to 3-dimensional space allows for the use of additional variables simultaneously; interaction techniques allow for the modification of structures in a visual manner. The concepts and techniques presented here are generic and, as such, can be applied beyond software analysis for the visualization of similarly structured data. The techniques' practicability is demonstrated by several qualitative studies using subject data from industry-scale software systems. The studies provide initial evidence that the techniques' application yields useful insights into the subject data and its interrelationships in several scenarios.},
  language  = {en}
}
@phdthesis{Trost2014,
  author    = {Trost, Gerda},
  title     = {Poly(A) Polymerase 1 (PAPS1) influences organ size and pathogen response in Arabidopsis thaliana},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72345},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Polyadenylation of pre-mRNAs is critical for efficient nuclear export, stability, and translation of the mature mRNAs, and thus for gene expression. The bulk of pre-mRNAs are processed by canonical nuclear poly(A) polymerase (PAPS). Both vertebrate and higher-plant genomes encode more than one isoform of this enzyme, and these are coexpressed in different tissues. However, in neither case is it known whether the isoforms fulfill different functions or polyadenylate distinct subsets of pre-mRNAs. This thesis shows that the three canonical nuclear PAPS isoforms in Arabidopsis are functionally specialized owing to their evolutionarily divergent C-terminal domains. A moderate loss-of-function mutant in PAPS1 leads to increase in floral organ size, whereas leaf size is reduced. A strong loss-of-function mutation causes a male gametophytic defect, whereas a weak allele leads to reduced leaf growth. By contrast, plants lacking both PAPS2 and PAPS4 function are viable with wild-type leaf growth. Polyadenylation of SMALL AUXIN UP RNA (SAUR) mRNAs depends specifically on PAPS1 function. The resulting reduction in SAUR activity in paps1 mutants contributes to their reduced leaf growth, providing a causal link between polyadenylation of specific pre-mRNAs by a particular PAPS isoform and plant growth. Additionally, opposite effects of PAPS1 on leaf and flower growth reflect the different identities of these organs. The overgrowth of paps1 mutant petals is due to increased recruitment of founder cells into early organ primordia whereas the reduced leaf size is due to an ectopic pathogen response. This constitutive immune response leads to increased resistance to the biotrophic oomycete Hyaloperonospora arabidopsidis and reflects activation of the salicylic acid-independent signalling pathway downstream of ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1)/PHYTOALEXIN DEFICIENT4 (PAD4). Immune responses are accompanied by intracellular redox changes. Consistent with this, the redox-status of the chloroplast is altered in paps1-1 mutants. The molecular effects of the paps1-1 mutation were analysed using an RNA sequencing approach that distinguishes between long- and short tailed mRNA. The results shown here suggest the existence of an additional layer of regulation in plants and possibly vertebrate gene expression, whereby the relative activities of canonical nuclear PAPS isoforms control de novo synthesized poly(A) tail length and hence expression of specific subsets of mRNAs.},
  language  = {en}
}
@phdthesis{Trabant2014,
  author    = {Trabant, Christoph},
  title     = {Ultrafast photoinduced phase transitions in complex materials probed by time-resolved resonant soft x-ray diffraction},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71377},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {In processing and data storage mainly ferromagnetic (FM) materials are being used. Approaching physical limits, new concepts have to be found for faster, smaller switches, for higher data densities and more energy efficiency. Some of the discussed new concepts involve the material classes of correlated oxides and materials with antiferromagnetic coupling. Their applicability depends critically on their switching behavior, i.e., how fast and how energy efficient material properties can be manipulated. This thesis presents investigations of ultrafast non-equilibrium phase transitions on such new materials. In transition metal oxides (TMOs) the coupling of different degrees of freedom and resulting low energy excitation spectrum often result in spectacular changes of macroscopic properties (colossal magneto resistance, superconductivity, metal-to-insulator transitions) often accompanied by nanoscale order of spins, charges, orbital occupation and by lattice distortions, which make these material attractive. Magnetite served as a prototype for functional TMOs showing a metal-to-insulator-transition (MIT) at T = 123 K. By probing the charge and orbital order as well as the structure after an optical excitation we found that the electronic order and the structural distortion, characteristics of the insulating phase in thermal equilibrium, are destroyed within the experimental resolution of 300 fs. The MIT itself occurs on a 1.5 ps timescale. It shows that MITs in functional materials are several thousand times faster than switching processes in semiconductors. Recently ferrimagnetic and antiferromagnetic (AFM) materials have become interesting. It was shown in ferrimagnetic GdFeCo, that the transfer of angular momentum between two opposed FM subsystems with different time constants leads to a switching of the magnetization after laser pulse excitation. In addition it was theoretically predicted that demagnetization dynamics in AFM should occur faster than in FM materials as no net angular momentum has to be transferred out of the spin system. We investigated two different AFM materials in order to learn more about their ultrafast dynamics. In Ho, a metallic AFM below T ≈ 130 K, we found that the AFM Ho can not only be faster but also ten times more energy efficiently destroyed as order in FM comparable metals. In EuTe, an AFM semiconductor below T ≈ 10 K, we compared the loss of magnetization and laser-induced structural distortion in one and the same experiment. Our experiment shows that they are effectively disentangled. An exception is an ultrafast release of lattice dynamics, which we assign to the release of magnetostriction. The results presented here were obtained with time-resolved resonant soft x-ray diffraction at the Femtoslicing source of the Helmholtz-Zentrum Berlin and at the free-electron laser in Stanford (LCLS). In addition the development and setup of a new UHV-diffractometer for these experiments will be reported.},
  language  = {en}
}
@phdthesis{Tinnefeld2014,
  author    = {Tinnefeld, Christian},
  title     = {Building a columnar database on shared main memory-based storage},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-72063},
  school      = {Universit{\"a}t Potsdam},
  pages     = {175},
  year      = {2014},
  abstract  = {In the field of disk-based parallel database management systems exists a great variety of solutions based on a shared-storage or a shared-nothing architecture. In contrast, main memory-based parallel database management systems are dominated solely by the shared-nothing approach as it preserves the in-memory performance advantage by processing data locally on each server. We argue that this unilateral development is going to cease due to the combination of the following three trends: a) Nowadays network technology features remote direct memory access (RDMA) and narrows the performance gap between accessing main memory inside a server and of a remote server to and even below a single order of magnitude. b) Modern storage systems scale gracefully, are elastic, and provide high-availability. c) A modern storage system such as Stanford's RAMCloud even keeps all data resident in main memory. Exploiting these characteristics in the context of a main-memory parallel database management system is desirable. The advent of RDMA-enabled network technology makes the creation of a parallel main memory DBMS based on a shared-storage approach feasible. This thesis describes building a columnar database on shared main memory-based storage. The thesis discusses the resulting architecture (Part I), the implications on query processing (Part II), and presents an evaluation of the resulting solution in terms of performance, high-availability, and elasticity (Part III). In our architecture, we use Stanford's RAMCloud as shared-storage, and the self-designed and developed in-memory AnalyticsDB as relational query processor on top. AnalyticsDB encapsulates data access and operator execution via an interface which allows seamless switching between local and remote main memory, while RAMCloud provides not only storage capacity, but also processing power. Combining both aspects allows pushing-down the execution of database operators into the storage system. We describe how the columnar data processed by AnalyticsDB is mapped to RAMCloud's key-value data model and how the performance advantages of columnar data storage can be preserved. The combination of fast network technology and the possibility to execute database operators in the storage system opens the discussion for site selection. We construct a system model that allows the estimation of operator execution costs in terms of network transfer, data processed in memory, and wall time. This can be used for database operators that work on one relation at a time - such as a scan or materialize operation - to discuss the site selection problem (data pull vs. operator push). Since a database query translates to the execution of several database operators, it is possible that the optimal site selection varies per operator. For the execution of a database operator that works on two (or more) relations at a time, such as a join, the system model is enriched by additional factors such as the chosen algorithm (e.g. Grace- vs. Distributed Block Nested Loop Join vs. Cyclo-Join), the data partitioning of the respective relations, and their overlapping as well as the allowed resource allocation. We present an evaluation on a cluster with 60 nodes where all nodes are connected via RDMA-enabled network equipment. We show that query processing performance is about 2.4x slower if everything is done via the data pull operator execution strategy (i.e. RAMCloud is being used only for data access) and about 27\% slower if operator execution is also supported inside RAMCloud (in comparison to operating only on main memory inside a server without any network communication at all). The fast-crash recovery feature of RAMCloud can be leveraged to provide high-availability, e.g. a server crash during query execution only delays the query response for about one second. Our solution is elastic in a way that it can adapt to changing workloads a) within seconds, b) without interruption of the ongoing query processing, and c) without manual intervention.},
  language  = {en}
}
@phdthesis{Tietz2014,
  author    = {Tietz, Marcel},
  title     = {Europ{\"a}isches Verwaltungsmanagement : Vergleich von Hauptst{\"a}dten neuer und alter Mitgliedsstaaten der EU am Beispiel der B{\"u}rgerdienste},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72171},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Im Rahmen der Dissertation wird die Anwendung und Wirkung von Kernelementen des New Public Management (NPM) am Beispiel der B{\"u}rgerdienste der sechs europ{\"a}ischen Hauptst{\"a}dte Berlin, Br{\"u}ssel, Kopenhagen, Madrid, Prag und Warschau analysiert. Hierbei steht der Vergleich von Hauptst{\"a}dten der MOE-Staaten mit Hauptst{\"a}dten alter EU-Mitgliedsstaaten im Vordergrund. Es wird die folgende Forschungshypothese untersucht: Die Verwaltungen in den Hauptst{\"a}dten der {\"o}stlichen Mitgliedsstaaten der EU haben in Folge der grunds{\"a}tzlichen gesellschaftlichen und politischen Umbr{\"u}che in den 1990er Jahren bedeutend mehr Kernelemente des NPM beim Neuaufbau ihrer {\"o}ffentlichen Verwaltungen eingef{\"u}hrt. Durch den folgerichtigen Aufbau kundenorientierter und moderner Verwaltungen sowie der strikten Anwendung der Kernelemente des New Public Management arbeiten die B{\"u}rgerdienste in den Hauptst{\"a}dten {\"o}stlicher EU-Mitgliedsstaaten effizienter und wirkungsvoller als vergleichbare B{\"u}rgerdienste in den Hauptst{\"a}dten westlicher EU-Mitgliedsstaaten. Zur {\"U}berpr{\"u}fung der Forschungshypothese werden die Vergleichsst{\"a}dte zun{\"a}chst den entsprechenden Rechts- und Verwaltungstraditionen (kontinentaleurop{\"a}isch deutsch, napoleonisch und skandinavisch) zugeordnet und bez{\"u}glich ihrer Ausgangslage zum Aufbau einer modernen Verwaltung (Westeurop{\"a}ische Verwaltung, Wiedervereinigungsverwaltung und Transformations-verwaltung) kategorisiert. Im Anschluss werden die institutionellen Voraussetzungen hinterfragt, was die deskriptive Darstellung der Stadt- und Verwaltungsgeschichte sowie die Untersuchung von organisatorischen Strukturen der B{\"u}rgerdienste, die Anwendung der NPM-Instrumente als auch die Innen- und Außenperspektive des NPM umfasst. Es wird festgestellt, ob und in welcher Form die B{\"u}rgerdienste der Vergleichsst{\"a}dte die Kernelemente des NPM anwenden. Im Anschluss werden die Vergleichsst{\"a}dte bez{\"u}glich der Anwendung der Kernelemente miteinander verglichen, wobei der Fokus auf dem pers{\"o}nlichen Vertriebsweg und der Kundenorientierung liegt. Der folgende Teil der Dissertation befasst sich mit dem Output der B{\"u}rgerdienste, der auf operative Resultate untersucht und verglichen wird. Hierbei stellt sich insbesondere die Frage nach den Leistungsmengen und der Produktivit{\"a}t des Outputs. Es werden aber auch die Ergebnisse von Verwaltungsprozessen untersucht, insbesondere in Bezug auf die Kundenorientierung. Hierf{\"u}r wird ein Effizienzvergleich der B{\"u}rgerdienste in den Vergleichsst{\"a}dten anhand einer relativen Effizienzmessung und der Free Disposal Hull (FDH)-Methode nach Bouckaert durchgef{\"u}hrt. Es ist eine Konzentration auf popul{\"a}re Dienstleistungen aus dem Portfolio der B{\"u}rgerdienste notwendig. Daher werden die vergleichbaren Dienstleistungen Melde-, Personalausweis-, F{\"u}hrerschein- und Reisepass-angelegenheiten unter Einbeziehung des Vollzeit{\"a}quivalents zur Berechnung der Effizienz der B{\"u}rgerdienste herangezogen. Hierf{\"u}r werden Daten aus den Jahren 2009 bis 2011 genutzt, die teilweise aus verwaltungsinternen Datenbanken stammen. Anschließend wird der Versuch unternommen, den Outcome in die Effizienzanalyse der B{\"u}rgerdienste einfließen zu lassen. In diesem Zusammenhang wird die Anwendbarkeit von verschiedenen erweiterten Best-Practice-Verfahren und auch eine Erweiterung der relativen Effizienzmessung und der FDH-Methode gepr{\"u}ft. Als Gesamtfazit der Dissertation kann festgehalten werden, dass die B{\"u}rgerdienste in den untersuchten Hauptst{\"a}dten der MOE-Staaten nicht mehr Kernelemente des NPM anwenden, als die Hauptst{\"a}dte der westlichen Mitgliedsstaaten der EU. Im Gegenteil wendet Prag deutlich weniger NPM-Instrumente als andere Vergleichsst{\"a}dte an, wohingegen Warschau zwar viele NPM-Instrumente anwendet, jedoch immer von einer westeurop{\"a}ischen Vergleichsstadt {\"u}bertroffen wird. Auch die Hypothese, dass die B{\"u}rgerdienste in den Hauptst{\"a}dten der MOE-Staaten effizienter arbeiten als vergleichbare B{\"u}rgerdienste in den Hauptst{\"a}dten westlicher EU-Mitgliedsstaaten wurde durch die Dissertation entkr{\"a}ftet. Das Gegenteil ist der Fall, da Prag und Warschau im Rahmen des Effizienzvergleichs lediglich durchschnittliche oder schlechte Performances aufweisen. Die aufgestellte Hypothese ist durch die Forschungsergebnisse widerlegt, lediglich das gute Abschneiden der Vergleichsstadt Warschau bei der Anwendungsanalyse kann einen Teil der These im gewissen Umfang best{\"a}tigen.},
  language  = {de}
}
@phdthesis{Tenenboim2014,
  author    = {Tenenboim, Yehezkel},
  title     = {Characterization of a Chlamydomonas protein involved in cell division and autophagy},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70650},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {The contractile vacuole (CV) is an osmoregulatory organelle found exclusively in algae and protists. In addition to expelling excessive water out of the cell, it also expels ions and other metabolites and thereby contributes to the cell's metabolic homeostasis. The interest in the CV reaches beyond its immediate cellular roles. The CV's function is tightly related to basic cellular processes such as membrane dynamics and vesicle budding and fusion; several physiological processes in animals, such as synaptic neurotransmission and blood filtration in the kidney, are related to the CV's function; and several pathogens, such as the causative agents of sleeping sickness, possess CVs, which may serve as pharmacological targets. The green alga Chlamydomonas reinhardtii has two CVs. They are the smallest known CVs in nature, and they remain relatively untouched in the CV-related literature. Many genes that have been shown to be related to the CV in other organisms have close homologues in C. reinhardtii. We attempted to silence some of these genes and observe the effect on the CV. One of our genes, VMP1, caused striking, severe phenotypes when silenced. Cells exhibited defective cytokinesis and aberrant morphologies. The CV, incidentally, remained unscathed. In addition, mutant cells showed some evidence of disrupted autophagy. Several important regulators of the cell cycle as well as autophagy were found to be underexpressed in the mutant. Lipidomic analysis revealed many meaningful changes between wild-type and mutant cells, reinforcing the compromised-autophagy observation. VMP1 is a singular protein, with homologues in numerous eukaryotic organisms (aside from fungi), but usually with no relatives in each particular genome. Since its first characterization in 2002 it has been associated with several cellular processes and functions, namely autophagy, programmed cell-death, secretion, cell adhesion, and organelle biogenesis. It has been implicated in several human diseases: pancreatitis, diabetes, and several types of cancer. Our results reiterate some of the observations in VMP1's six reported homologues, but, importantly, show for the first time an involvement of this protein in cell division. The mechanisms underlying this involvement in Chlamydomonas, as well as other key aspects, such as VMP1's subcellular localization and interaction partners, still await elucidation.},
  language  = {en}
}
@phdthesis{Takouna2014,
  author    = {Takouna, Ibrahim},
  title     = {Energy-efficient and performance-aware virtual machine management for cloud data centers},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72399},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Virtualisierte Cloud Datenzentren stellen nach Bedarf Ressourcen zur Verf{\"u}gu-ng, erm{\"o}glichen agile Ressourcenbereitstellung und beherbergen heterogene Applikationen mit verschiedenen Anforderungen an Ressourcen. Solche Datenzentren verbrauchen enorme Mengen an Energie, was die Erh{\"o}hung der Betriebskosten, der W{\"a}rme innerhalb der Zentren und des Kohlendioxidausstoßes verursacht. Der Anstieg des Energieverbrauches kann durch ein ineffektives Ressourcenmanagement, das die ineffiziente Ressourcenausnutzung verursacht, entstehen. Die vorliegende Dissertation stellt detaillierte Modelle und neue Verfahren f{\"u}r virtualisiertes Ressourcenmanagement in Cloud Datenzentren vor. Die vorgestellten Verfahren ziehen das Service-Level-Agreement (SLA) und die Heterogenit{\"a}t der Auslastung bez{\"u}glich des Bedarfs an Speicherzugriffen und Kommunikationsmustern von Web- und HPC- (High Performance Computing) Applikationen in Betracht. Um die pr{\"a}sentierten Techniken zu evaluieren, verwenden wir Simulationen und echte Protokollierung der Auslastungen von Web- und HPC- Applikationen. Außerdem vergleichen wir unser Techniken und Verfahren mit anderen aktuellen Verfahren durch die Anwendung von verschiedenen Performance Metriken. Die Hauptbeitr{\"a}ge dieser Dissertation sind Folgendes: Ein Proaktives auf robuster Optimierung basierendes Ressourcenbereitstellungsverfahren. Dieses Verfahren erh{\"o}ht die F{\"a}higkeit der Hostes zur Verf{\"u}g-ungsstellung von mehr VMs. Gleichzeitig aber wird der unn{\"o}tige Energieverbrauch minimiert. Zus{\"a}tzlich mindert diese Technik unerw{\"u}nschte {\"A}nde-rungen im Energiezustand des Servers. Die vorgestellte Technik nutzt einen auf Intervall basierenden Vorhersagealgorithmus zur Implementierung einer robusten Optimierung. Dabei werden unsichere Anforderungen in Betracht gezogen. Ein adaptives und auf Intervall basierendes Verfahren zur Vorhersage des Arbeitsaufkommens mit hohen, in k{\"u}rzer Zeit auftretenden Schwankungen. Die Intervall basierende Vorhersage ist implementiert in der Standard Abweichung Variante und in der Median absoluter Abweichung Variante. Die Intervall-{\"A}nderungen basieren auf einem adaptiven Vertrauensfenster um die Schwankungen des Arbeitsaufkommens zu bew{\"a}ltigen. Eine robuste VM Zusammenlegung f{\"u}r ein effizientes Energie und Performance Management. Dies erm{\"o}glicht die gegenseitige Abh{\"a}ngigkeit zwischen der Energie und der Performance zu minimieren. Unser Verfahren reduziert die Anzahl der VM-Migrationen im Vergleich mit den neu vor kurzem vorgestellten Verfahren. Dies tr{\"a}gt auch zur Reduzierung des durch das Netzwerk verursachten Energieverbrauches. Außerdem reduziert dieses Verfahren SLA-Verletzungen und die Anzahl von {\"A}nderungen an Energiezus-t{\"a}nden. Ein generisches Modell f{\"u}r das Netzwerk eines Datenzentrums um die verz{\"o}-gerte Kommunikation und ihre Auswirkung auf die VM Performance und auf die Netzwerkenergie zu simulieren. Außerdem wird ein generisches Modell f{\"u}r ein Memory-Bus des Servers vorgestellt. Dieses Modell beinhaltet auch Modelle f{\"u}r die Latenzzeit und den Energieverbrauch f{\"u}r verschiedene Memory Frequenzen. Dies erlaubt eine Simulation der Memory Verz{\"o}gerung und ihre Auswirkung auf die VM-Performance und auf den Memory Energieverbrauch. Kommunikation bewusste und Energie effiziente Zusammenlegung f{\"u}r parallele Applikationen um die dynamische Entdeckung von Kommunikationsmustern und das Umplanen von VMs zu erm{\"o}glichen. Das Umplanen von VMs benutzt eine auf den entdeckten Kommunikationsmustern basierende Migration. Eine neue Technik zur Entdeckung von dynamischen Mustern ist implementiert. Sie basiert auf der Signal Verarbeitung des Netzwerks von VMs, anstatt die Informationen des virtuellen Umstellung der Hosts oder der Initiierung der VMs zu nutzen. Das Ergebnis zeigt, dass unsere Methode die durchschnittliche Anwendung des Netzwerks reduziert und aufgrund der Reduzierung der aktiven Umstellungen Energie gespart. Außerdem bietet sie eine bessere VM Performance im Vergleich zu der CPU-basierten Platzierung. Memory bewusste VM Zusammenlegung f{\"u}r unabh{\"a}ngige VMs. Sie nutzt die Vielfalt des VMs Memory Zuganges um die Anwendung vom Memory-Bus der Hosts zu balancieren. Die vorgestellte Technik, Memory-Bus Load Balancing (MLB), verteilt die VMs reaktiv neu im Bezug auf ihre Anwendung vom Memory-Bus. Sie nutzt die VM Migration um die Performance des gesamtem Systems zu verbessern. Außerdem sind die dynamische Spannung, die Frequenz Skalierung des Memory und die MLB Methode kombiniert um ein besseres Energiesparen zu leisten.},
  language  = {en}
}
@phdthesis{Strauss2014,
  author    = {Strauß, Jens},
  title     = {Organic carbon in ice-rich permafrost},
  doi       = {10.25932/publishup-7523},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-75236},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XIII, 107, 102},
  year      = {2014},
  abstract  = {Permafrost, defined as ground that is frozen for at least two consecutive years, is a distinct feature of the terrestrial unglaciated Arctic. It covers approximately one quarter of the land area of the Northern Hemisphere (23,000,000 km²). Arctic landscapes, especially those underlain by permafrost, are threatened by climate warming and may degrade in different ways, including active layer deepening, thermal erosion, and development of rapid thaw features. In Siberian and Alaskan late Pleistocene ice-rich Yedoma permafrost, rapid and deep thaw processes (called thermokarst) can mobilize deep organic carbon (below 3 m depth) by surface subsidence due to loss of ground ice. Increased permafrost thaw could cause a feedback loop of global significance if its stored frozen organic carbon is reintroduced into the active carbon cycle as greenhouse gases, which accelerate warming and inducing more permafrost thaw and carbon release. To assess this concern, the major objective of the thesis was to enhance the understanding of the origin of Yedoma as well as to assess the associated organic carbon pool size and carbon quality (concerning degradability). The key research questions were: - How did Yedoma deposits accumulate? - How much organic carbon is stored in the Yedoma region? - What is the susceptibility of the Yedoma region's carbon for future decomposition? To address these three research questions, an interdisciplinary approach, including detailed field studies and sampling in Siberia and Alaska as well as methods of sedimentology, organic biogeochemistry, remote sensing, statistical analyses, and computational modeling were applied. To provide a panarctic context, this thesis additionally includes results both from a newly compiled northern circumpolar carbon database and from a model assessment of carbon fluxes in a warming Arctic. The Yedoma samples show a homogeneous grain-size composition. All samples were poorly sorted with a multi-modal grain-size distribution, indicating various (re-) transport processes. This contradicts the popular pure loess deposition hypothesis for the origin of Yedoma permafrost. The absence of large-scale grinding processes via glaciers and ice sheets in northeast Siberian lowlands, processes which are necessary to create loess as material source, suggests the polygenetic origin of Yedoma deposits. Based on the largest available data set of the key parameters, including organic carbon content, bulk density, ground ice content, and deposit volume (thickness and coverage) from Siberian and Alaskan study sites, this thesis further shows that deep frozen organic carbon in the Yedoma region consists of two distinct major reservoirs, Yedoma deposits and thermokarst deposits (formed in thaw-lake basins). Yedoma deposits contain ~80 Gt and thermokarst deposits ~130 Gt organic carbon, or a total of ~210 Gt. Depending on the approach used for calculating uncertainty, the range for the total Yedoma region carbon store is ±75 \% and ±20 \% for conservative single and multiple bootstrapping calculations, respectively. Despite the fact that these findings reduce the Yedoma region carbon pool by nearly a factor of two compared to previous estimates, this frozen organic carbon is still capable of inducing a permafrost carbon feedback to climate warming. The complete northern circumpolar permafrost region contains between 1100 and 1500 Gt organic carbon, of which ~60 \% is perennially frozen and decoupled from the short-term carbon cycle. When thawed and reintroduced into the active carbon cycle, the organic matter qualities become relevant. Furthermore, results from investigations into Yedoma and thermokarst organic matter quality studies showed that Yedoma and thermokarst organic matter exhibit no depth-dependent quality trend. This is evidence that after freezing, the ancient organic matter is preserved in a state of constant quality. The applied alkane and fatty-acid-based biomarker proxies including the carbon-preference and the higher-land-plant-fatty-acid indices show a broad range of organic matter quality and thus no significantly different qualities of the organic matter stored in thermokarst deposits compared to Yedoma deposits. This lack of quality differences shows that the organic matter biodegradability depends on different decomposition trajectories and the previous decomposition/incorporation history. Finally, the fate of the organic matter has been assessed by implementing deep carbon pools and thermokarst processes in a permafrost carbon model. Under various warming scenarios for the northern circumpolar permafrost region, model results show a carbon release from permafrost regions of up to ~140 Gt and ~310 Gt by the years 2100 and 2300, respectively. The additional warming caused by the carbon release from newly-thawed permafrost contributes 0.03 to 0.14°C by the year 2100. The model simulations predict that a further increase by the 23rd century will add 0.4°C to global mean surface air temperatures. In conclusion, Yedoma deposit formation during the late Pleistocene was dominated by water-related (alluvial/fluvial/lacustrine) as well as aeolian processes under periglacial conditions. The circumarctic permafrost region, including the Yedoma region, contains a substantial amount of currently frozen organic carbon. The carbon of the Yedoma region is well-preserved and therefore available for decomposition after thaw. A missing quality-depth trend shows that permafrost preserves the quality of ancient organic matter. When the organic matter is mobilized by deep degradation processes, the northern permafrost region may add up to 0.4°C to the global warming by the year 2300.},
  language  = {en}
}
@phdthesis{Steyrleuthner2014,
  author    = {Steyrleuthner, Robert},
  title     = {Korrelation von Struktur, optischen Eigenschaften und Ladungstransport in einem konjugierten Naphthalindiimid-Bithiophen Copolymer mit herausragender Elektronenmobilit{\"a}t},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71413},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Organische Halbleiter besitzen neue, bemerkenswerte Materialeigenschaften, die sie f{\"u}r die grundlegende Forschung wie auch aktuelle technologische Entwicklung (bsw. org. Leuchtdioden, org. Solarzellen) interessant werden lassen. Aufgrund der starken konformative Freiheit der konjugierten Polymerketten f{\"u}hrt die Vielzahl der m{\"o}glichen Anordnungen und die schwache intermolekulare Wechselwirkung f{\"u}r gew{\"o}hnlich zu geringer struktureller Ordnung im Festk{\"o}rper. Die Morphologie hat gleichzeitig direkten Einfluss auf die elektronische Struktur der organischen Halbleiter, welches sich meistens in einer deutlichen Reduktion der Ladungstr{\"a}gerbeweglichkeit gegen{\"u}ber den anorganischen Verwandten zeigt. So stellt die Beweglichkeit der Ladungen im Halbleiter einen der limitierenden Faktoren f{\"u}r die Leistungsf{\"a}higkeit bzw. den Wirkungsgrad von funktionellen organischen Bauteilen dar. Im Jahr 2009 wurde ein neues auf Naphthalindiimid und Bithiophen basierendes Dornor/Akzeptor Copolymer vorgestellt [P(NDI2OD‑T2)], welches sich durch seine außergew{\"o}hnlich hohe Ladungstr{\"a}germobilit{\"a}t auszeichnet. In dieser Arbeit wird die Ladungstr{\"a}germobilit{\"a}t in P(NDI2OD‑T2) bestimmt, und der Transport durch eine geringe energetischer Unordnung charakterisiert. Obwohl dieses Material zun{\"a}chst als amorph beschrieben wurde zeigt eine detaillierte Analyse der optischen Eigenschaften von P(NDI2OD‑T2), dass bereits in L{\"o}sung geordnete Vorstufen supramolekularer Strukturen (Aggregate) existieren. Quantenchemische Berechnungen belegen die beobachteten spektralen {\"A}nderungen. Mithilfe der NMR-Spektroskopie kann die Bildung der Aggregate unabh{\"a}ngig von optischer Spektroskopie best{\"a}tigt werden. Die Analytische Ultrazentrifugation an P(NDI2OD‑T2) L{\"o}sungen legt nahe, dass sich die Aggregation innerhalb der einzelnen Ketten unter Reduktion des hydrodynamischen Radius vollzieht. Die Ausbildung supramolekularen Strukturen nimmt auch eine signifikante Rolle bei der Filmbildung ein und verhindert gleichzeitig die Herstellung amorpher P(NDI2OD‑T2) Filme. Durch chemische Modifikation der P(NDI2OD‑T2)-Kette und verschiedener Prozessierungs-Methoden wurde eine {\"A}nderung des Kristallinit{\"a}tsgrades und gleichzeitig der Orientierung der kristallinen Dom{\"a}nen erreicht und mittels R{\"o}ntgenbeugung quantifiziert. In hochaufl{\"o}senden Elektronenmikroskopie-Messungen werden die Netzebenen und deren Einbettung in die semikristallinen Strukturen direkt abgebildet. Aus der Kombination der verschiedenen Methoden erschließt sich ein Gesamtbild der Nah- und Fernordnung in P(NDI2OD‑T2). {\"U}ber die Messung der Elektronenmobilit{\"a}t dieser Schichten wird die Anisotropie des Ladungstransports in den kristallographischen Raumrichtungen von P(NDI2OD‑T2) charakterisiert und die Bedeutung der intramolekularen Wechselwirkung f{\"u}r effizienten Ladungstransport herausgearbeitet. Gleichzeitig wird deutlich, wie die Verwendung von gr{\"o}ßeren und planaren funktionellen Gruppen zu h{\"o}heren Ladungstr{\"a}germobilit{\"a}ten f{\"u}hrt, welche im Vergleich zu klassischen semikristallinen Polymeren weniger sensitiv auf die strukturelle Unordnung im Film sind.},
  language  = {de}
}
@phdthesis{Steinhaus2014,
  author    = {Steinhaus, Sebastian Peter},
  title     = {Constructing quantum spacetime},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72558},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Despite remarkable progress made in the past century, which has revolutionized our understanding of the universe, there are numerous open questions left in theoretical physics. Particularly important is the fact that the theories describing the fundamental interactions of nature are incompatible. Einstein's theory of general relative describes gravity as a dynamical spacetime, which is curved by matter and whose curvature determines the motion of matter. On the other hand we have quantum field theory, in form of the standard model of particle physics, where particles interact via the remaining interactions - electromagnetic, weak and strong interaction - on a flat, static spacetime without gravity. A theory of quantum gravity is hoped to cure this incompatibility by heuristically replacing classical spacetime by quantum spacetime'. Several approaches exist attempting to define such a theory with differing underlying premises and ideas, where it is not clear which is to be preferred. Yet a minimal requirement is the compatibility with the classical theory, they attempt to generalize. Interestingly many of these models rely on discrete structures in their definition or postulate discreteness of spacetime to be fundamental. Besides the direct advantages discretisations provide, e.g. permitting numerical simulations, they come with serious caveats requiring thorough investigation: In general discretisations break fundamental diffeomorphism symmetry of gravity and are generically not unique. Both complicates establishing the connection to the classical continuum theory. The main focus of this thesis lies in the investigation of this relation for spin foam models. This is done on different levels of the discretisation / triangulation, ranging from few simplices up to the continuum limit. In the regime of very few simplices we confirm and deepen the connection of spin foam models to discrete gravity. Moreover, we discuss dynamical, e.g. diffeomorphism invariance in the discrete, to fix the ambiguities of the models. In order to satisfy these conditions, the discrete models have to be improved in a renormalisation procedure, which also allows us to study their continuum dynamics. Applied to simplified spin foam models, we uncover a rich, non--trivial fixed point structure, which we summarize in a phase diagram. Inspired by these methods, we propose a method to consistently construct the continuum theory, which comes with a unique vacuum state.},
  language  = {en}
}
@phdthesis{Steinert2014,
  author    = {Steinert, Bastian},
  title     = {Built-in recovery support for explorative programming},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71305},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {This work introduces concepts and corresponding tool support to enable a complementary approach in dealing with recovery. Programmers need to recover a development state, or a part thereof, when previously made changes reveal undesired implications. However, when the need arises suddenly and unexpectedly, recovery often involves expensive and tedious work. To avoid tedious work, literature recommends keeping away from unexpected recovery demands by following a structured and disciplined approach, which consists of the application of various best practices including working only on one thing at a time, performing small steps, as well as making proper use of versioning and testing tools. However, the attempt to avoid unexpected recovery is both time-consuming and error-prone. On the one hand, it requires disproportionate effort to minimize the risk of unexpected situations. On the other hand, applying recommended practices selectively, which saves time, can hardly avoid recovery. In addition, the constant need for foresight and self-control has unfavorable implications. It is exhaustive and impedes creative problem solving. This work proposes to make recovery fast and easy and introduces corresponding support called CoExist. Such dedicated support turns situations of unanticipated recovery from tedious experiences into pleasant ones. It makes recovery fast and easy to accomplish, even if explicit commits are unavailable or tests have been ignored for some time. When mistakes and unexpected insights are no longer associated with tedious corrective actions, programmers are encouraged to change source code as a means to reason about it, as opposed to making changes only after structuring and evaluating them mentally. This work further reports on an implementation of the proposed tool support in the Squeak/Smalltalk development environment. The development of the tools has been accompanied by regular performance and usability tests. In addition, this work investigates whether the proposed tools affect programmers' performance. In a controlled lab study, 22 participants improved the design of two different applications. Using a repeated measurement setup, the study examined the effect of providing CoExist on programming performance. The result of analyzing 88 hours of programming suggests that built-in recovery support as provided with CoExist positively has a positive effect on programming performance in explorative programming tasks.},
  language  = {en}
}
@phdthesis{Sorce2014,
  author    = {Sorce, Jenny},
  title     = {From Spitzer mid-infrared observations and measurements of peculiar velocities to constrained simulations of the local universe},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72486},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xx, 303},
  year      = {2014},
  abstract  = {Galaxies are observational probes to study the Large Scale Structure. Their gravitational motions are tracers of the total matter density and therefore of the Large Scale Structure. Besides, studies of structure formation and galaxy evolution rely on numerical cosmological simulations. Still, only one universe observable from a given position, in time and space, is available for comparisons with simulations. The related cosmic variance affects our ability to interpret the results. Simulations constrained by observational data are a perfect remedy to this problem. Achieving such simulations requires the projects Cosmic flows and CLUES. Cosmic flows builds catalogs of accurate distance measurements to map deviations from the expansion. These measures are mainly obtained with the galaxy luminosity-rotation rate correlation. We present the calibration of that relation in the mid-infrared with observational data from Spitzer Space Telescope. Resulting accurate distance estimates will be included in the third catalog of the project. In the meantime, two catalogs up to 30 and 150 Mpc/h have been released. We report improvements and applications of the CLUES' method on these two catalogs. The technique is based on the constrained realization algorithm. The cosmic displacement field is computed with the Zel'dovich approximation. This latter is then reversed to relocate reconstructed three-dimensional constraints to their precursors' positions in the initial field. The size of the second catalog (8000 galaxies within 150 Mpc/h) highlighted the importance of minimizing the observational biases. By carrying out tests on mock catalogs, built from cosmological simulations, a method to minimize observational bias can be derived. Finally, for the first time, cosmological simulations are constrained solely by peculiar velocities. The process is successful as resulting simulations resemble the Local Universe. The major attractors and voids are simulated at positions approaching observational positions by a few megaparsecs, thus reaching the limit imposed by the linear theory.},
  language  = {en}
}
@phdthesis{Serrano2014,
  author    = {Serrano, Paloma},
  title     = {Methanogens from Siberian permafrost as models for life on Mars : response to simulated martian conditions and biosignature characterization},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72299},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Mars is one of the best candidates among planetary bodies for supporting life. The presence of water in the form of ice and atmospheric vapour together with the availability of biogenic elements and energy are indicators of the possibility of hosting life as we know it. The occurrence of permanently frozen ground - permafrost, is a common phenomenon on Mars and it shows multiple morphological analogies with terrestrial permafrost. Despite the extreme inhospitable conditions, highly diverse microbial communities inhabit terrestrial permafrost in large numbers. Among these are methanogenic archaea, which are anaerobic chemotrophic microorganisms that meet many of the metabolic and physiological requirements for survival on the martian subsurface. Moreover, methanogens from Siberian permafrost are extremely resistant against different types of physiological stresses as well as simulated martian thermo-physical and subsurface conditions, making them promising model organisms for potential life on Mars. The main aims of this investigation are to assess the survival of methanogenic archaea under Mars conditions, focusing on methanogens from Siberian permafrost, and to characterize their biosignatures by means of Raman spectroscopy, a powerful technology for microbial identification that will be used in the ExoMars mission. For this purpose, methanogens from Siberian permafrost and non-permafrost habitats were subjected to simulated martian desiccation by exposure to an ultra-low subfreezing temperature (-80ºC) and to Mars regolith (S-MRS and P-MRS) and atmospheric analogues. They were also exposed to different concentrations of perchlorate, a strong oxidant found in martian soils. Moreover, the biosignatures of methanogens were characterized at the single-cell level using confocal Raman microspectroscopy (CRM). The results showed survival and methane production in all methanogenic strains under simulated martian desiccation. After exposure to subfreezing temperatures, Siberian permafrost strains had a faster metabolic recovery, whereas the membranes of non-permafrost methanogens remained intact to a greater extent. The strain Methanosarcina soligelidi SMA-21 from Siberian permafrost showed significantly higher methane production rates than all other strains after the exposure to martian soil and atmospheric analogues, and all strains survived the presence of perchlorate at the concentration on Mars. Furthermore, CRM analyses revealed remarkable differences in the overall chemical composition of permafrost and non-permafrost strains of methanogens, regardless of their phylogenetic relationship. The convergence of the chemical composition in non-sister permafrost strains may be the consequence of adaptations to the environment, and could explain their greater resistance compared to the non-permafrost strains. As part of this study, Raman spectroscopy was evaluated as an analytical technique for remote detection of methanogens embedded in a mineral matrix. This thesis contributes to the understanding of the survival limits of methanogenic archaea under simulated martian conditions to further assess the hypothetical existence of life similar to methanogens on the martian subsurface. In addition, the overall chemical composition of methanogens was characterized for the first time by means of confocal Raman microspectroscopy, with potential implications for astrobiological research.},
  language  = {en}
}
@phdthesis{Senyuk2014,
  author    = {Senyuk, Ulyana},
  title     = {Zum Status relativ{\"a}hnlicher S{\"a}tze im Fr{\"u}hneuhochdeutschen},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-91673},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vi, 276},
  year      = {2014},
  abstract  = {Diese Arbeit befasst sich mit den sogenannten relativ{\"a}hnlichen S{\"a}tzen im Fr{\"u}hneuhochdeutschen und leistet somit einen Beitrag zur Subordinationsforschung des {\"a}lteren Deutsch. Relativ{\"a}hnliche S{\"a}tze sind formal durch ein satzinitiales anaphorisches d-Element und die Endstellung des finiten Verbs gekennzeichnet. Semantisch gesehen beziehen sie sich auf den vorangehenden Satz als Ganzes, indem sie ihn in bestimmter Weise weiterf{\"u}hren oder kommentieren. In der bisherigen Forschung werden diese S{\"a}tze satztypologisch als Haupts{\"a}tze mit Verbendstellung analysiert (vgl. dazu Maurer 1926, Behaghel 1932 und L{\"o}tscher 2000). Nach der ausf{\"u}hrlichen Diskussion der formalen Abh{\"a}ngigkeitsmarker im {\"a}lteren Deutsch sowie anhand einer umfangreichen korpusbasierten Untersuchung wird in dieser Arbeit gezeigt, dass relativ{\"a}hnliche S{\"a}tze im Fr{\"u}hneuhochdeutschen auch als abh{\"a}ngige S{\"a}tze - analog zu den weiterf{\"u}hrenden Relativs{\"a}tzen im Gegenwartsdeutschen - analysiert werden k{\"o}nnen. Die weiterf{\"u}hrenden Relativs{\"a}tze im Gegenwartsdeutschen enthalten satzinitial auch ein anaphorisches Element, das sich auf das Gesagte in dem vorangehenden Satz bezieht. Verbendstellung weisen sie ebenfalls auf (mehr zur Grammatik der weiterf{\"u}hrenden Relativs{\"a}tze vgl. insb. Brandt 1990 und Holler 2005). {\"U}ber die Untersuchung relativ{\"a}hnlicher S{\"a}tze hinaus befasst sich diese Arbeit ausf{\"u}hrlich mit formalen Abh{\"a}ngigkeitsmarkern des {\"a}lteren Deutsch, wie Verbendstellung, Einleiter und afinite Konstruktion.},
  language  = {de}
}
@phdthesis{Sen2014,
  author    = {Sen, Ali Tolga},
  title     = {Inversion of seismic source parameters for weak mining-induced and natural earthquakes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71914},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {The purpose of this thesis is to develop an automated inversion scheme to derive point and finite source parameters for weak earthquakes, here intended with the unusual meaning of earthquakes with magnitudes at the limit or below the bottom magnitude threshold of standard source inversion routines. The adopted inversion approaches entirely rely on existing inversion software, the methodological work mostly targeting the development and tuning of optimized inversion flows. The resulting inversion scheme is tested for very different datasets, and thus allows the discussion on the source inversion problem at different scales. In the first application, dealing with mining induced seismicity, the source parameters determination is addressed at a local scale, with source-sensor distance of less than 3 km. In this context, weak seismicity corresponds to event below magnitude MW 2.0, which are rarely target of automated source inversion routines. The second application considers a regional dataset, namely the aftershock sequence of the 2010 Maule earthquake (Chile), using broadband stations at regional distances, below 300 km. In this case, the magnitude range of the target aftershocks range down to MW 4.0. This dataset is here considered as a weak seismicity case, since the analysis of such moderate seismicity is generally investigated only by moment tensor inversion routines, with no attempt to resolve source duration or finite source parameters. In this work, automated multi-step inversion schemes are applied to both datasets with the aim of resolving point source parameters, both using double couple (DC) and full moment tensor (MT) models, source duration and finite source parameters. A major result of the analysis of weaker events is the increased size of resulting moment tensor catalogues, which interpretation may become not trivial. For this reason, a novel focal mechanism clustering approach is used to automatically classify focal mechanisms, allowing the investigation of the most relevant and repetitive rupture features. The inversion of the mining induced seismicity dataset reveals the repetitive occurrence of similar rupture processes, where the source geometry is controlled by the shape of the mined panel. Moreover, moment tensor solutions indicate a significant contribution of tensile processes. Also the second application highlights some characteristic geometrical features of the fault planes, which show a general consistency with the orientation of the slab. The additional inversion for source duration allowed to verify the empirical correlation for moment normalized earthquakes in subduction zones among a decreasing rupture duration with increasing source depth, which was so far only observed for larger events.},
  language  = {en}
}
@phdthesis{Schwarz2014,
  author    = {Schwarz, Franziska},
  title     = {Einfluss von Kalorienrestriktion auf den Metabolismus},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-83147},
  school      = {Universit{\"a}t Potsdam},
  pages     = {130},
  year      = {2014},
  abstract  = {Die H{\"a}ufung von Diabetes, Herz-Kreislauf-Erkrankungen und einigen Krebsarten, deren Entstehung auf {\"U}bergewicht und Bewegungsmangel zur{\"u}ckzuf{\"u}hren sind, ist ein aktuelles Problem unserer Gesellschaft. Insbesondere mit fortschreitendem Alter nehmen die damit einhergehenden Komplikationen zu. Umso bedeutender ist das Verst{\"a}ndnis der pathologischen Mechanismen in Folge von Adipositas, Bewegungsmangel, des Alterungsprozesses und den Einfluss-nehmenden Faktoren. Ziel dieser Arbeit war die Entstehung metabolischer Erkrankungen beim Menschen zu untersuchen. Die Auswertung von Verlaufsdaten anthropometrischer und metabolischer Parameter der 584 Teilnehmern der prospektiven ‚Metabolisches Syndrom Berlin Potsdam Follow-up Studie' wies f{\"u}r die gesamte Kohorte einen Anstieg an {\"U}bergewicht, ebenso eine Verschlechterung des Blutdrucks und des Glukosestoffwechsels auf. Wir untersuchten, ob das Hormon FGF21 Einfluss an dem Auftreten eines Diabetes mellitus Typ 2 (T2DM) oder des Metabolischen Syndroms (MetS) hat. Wir konnten zeigen, dass Personen, die sp{\"a}ter ein MetS entwickeln, bereits zu Studienbeginn einen erh{\"o}hten FGF21-Spiegel, einen h{\"o}heren BMI, WHR, Hb1Ac und diastolischen Blutdruck aufwiesen. Neben FGF21 wurde auch Vaspin in diesem Zusammenhang untersucht. Es zeigte sich, dass Personen, die sp{\"a}ter einen T2DM entwickeln, neben einer Erh{\"o}hung klinischer Parameter tendenziell erh{\"o}hte Spiegel des Hormons aufwiesen. Mit FGF21 und Vaspin wurden hier zwei neue Faktoren f{\"u}r die Vorhersage des Metabolischen Syndroms bzw. Diabetes mellitus Typ 2 identifiziert. Der langfristige Effekt einer Gewichtsreduktion wurde in einer Subkohorte von 60 Personen untersucht. Der {\"u}berwiegende Teil der Probanden mit Gewichtsabnahme-Intervention nahm in der ersten sechsmonatigen Phase erfolgreich ab. Jedoch zeigte sich ein deutlicher Trend zur Wiederzunahme des verlorenen Gewichts {\"u}ber den Beobachtungszeitraum von f{\"u}nf Jahren. Von besonderem Interesse war die Absch{\"a}tzung des kardiovaskul{\"a}ren Risikos {\"u}ber den Framingham Score. Es wurde deutlich, dass f{\"u}r Personen mit konstanter Gewichtsabnahme ein deutlich geringeres kardiovaskul{\"a}res Risiko bestand. Hingegen zeigten Personen mit konstanter Wiederzunahme oder starken Gewichtsschwankungen ein hohes kardiovaskul{\"a}res Risiko. Unsere Daten legten nahe, dass eine erfolgreiche dauerhafte Gewichtsreduktion statistisch mit einem erniedrigten kardiovaskul{\"a}ren Risiko assoziiert ist, w{\"a}hrend Probanden mit starken Gewichtsschwankungen oder einer Gewichtszunahme ein gesteigertes Risiko haben k{\"o}nnten. Um die Interaktion der molekularen Vorg{\"a}nge hinsichtlich der Gewichtsreduktion und Lebensspanne untersuchen zu k{\"o}nnen, nutzen wir den Modellorganismus C.elegans. Eine kontinuierliche Restriktion wirkte sich verl{\"a}ngernd, eine {\"U}berversorgung verk{\"u}rzend auf die Lebensspanne des Rundwurms aus. Der Einfluss eines zeitlich eingeschr{\"a}nkten, intermittierenden Nahrungsregimes, analog zum Weight-Cycling im Menschen, auf die Lebensspanne war von großem Interesse. Dieser regelm{\"a}ßige Wechsel zwischen ad libitum F{\"u}tterung und Restriktion hatte in Abh{\"a}ngigkeit von der H{\"a}ufigkeit der Restriktion einen unterschiedlich starken lebensverl{\"a}ngernden Effekt. Ph{\"a}nomene, wie Gewichtswiederzunahmen, sind in C.elegans nicht zu beobachten und beruhen vermutlich auf einem Mechanismus ist, der evolution{\"a}r j{\"u}nger und in C.elegans noch nicht angelegt ist. Um neue Stoffwechselwege zu identifizieren, die die Lebensspanne beeinflussen, wurden Metabolitenprofile genetischer als auch di{\"a}tetischer Langlebigkeitsmodelle analysiert. Diese Analysen wiesen den Tryptophan-Stoffwechsel als einen neuen, bisher noch nicht im Fokus stehenden Stoffwechselweg aus, der mit Langlebigkeit in Verbindung steht.},
  language  = {de}
}
@phdthesis{Schulz2014,
  author    = {Schulz, Anneli},
  title     = {Search for gamma-ray emission from bow shocks of runaway stars},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-73905},
  school      = {Universit{\"a}t Potsdam},
  pages     = {123},
  year      = {2014},
  abstract  = {The mystery of the origin of cosmic rays has been tackled for more than hundred years and is still not solved. Cosmic rays are detected with energies spanning more than 10 orders of magnitude and reaching energies up to ~10²¹ eV, far higher than any man-made accelerator can reach. Different theories on the astrophysical objects and processes creating such highly energetic particles have been proposed. A very prominent explanation for a process producing highly energetic particles is shock acceleration. The observation of high-energy gamma rays from supernova remnants, some of them revealing a shell like structure, is clear evidence that particles are accelerated to ultrarelativistic energies in the shocks of these objects. The environments of supernova remnants are complex and challenge detailed modelling of the processes leading to high-energy gamma-ray emission. The study of shock acceleration at bow shocks, created by the supersonic movement of individual stars through the interstellar medium, offers a unique possibility to determine the physical properties of shocks in a less complex environment. The shocked medium is heated by the stellar and the shock excited radiation, leading to thermal infrared emission. 28 bow shocks have been discovered through their infrared emission. Nonthermal radiation in radio and X-ray wavelengths has been detected from two bow shocks, pointing to the existence of relativistic particles in these systems. Theoretical models of the emission processes predict high-energy and very high-energy emission at a flux level in reach of current instruments. This work presents the search for gamma-ray emission from bow shocks of runaway stars in the energy regime from 100MeV to ~100TeV. The search is performed with the large area telescope (LAT) on-board the Fermi satellite and the H.E.S.S. telescopes located in the Khomas Highland in Namibia. The Fermi-LAT was launched in 2008 and is continuously scanning the sky since then. It detects photons with energies from 20MeV to over 300 GeV and has an unprecedented sensitivity. The all-sky coverage allows us to study all 28 bow shocks of runaway stars listed in the E-BOSS catalogue of infrared bow shocks. No significant emission was detected from any of the objects, although predicted by several theoretical models describing the non-thermal emission of bow shocks of runaway stars. The H.E.S.S. experiment is the most sensitive system of imaging atmospheric Cherenkov telescopes. It detects photons from several tens of GeV to ~100TeV. Seven of the bow shocks have been observed with H.E.S.S. and the data analysis is presented in this thesis. The analyses of the very-high energy data did not reveal significant emission from any of the sources either. This work presents the first systematic search for gamma-ray emission from bow shocks of runaway stars. For the first time Fermi-LAT data was specifically analysed to reveal emission from bow shocks of runaway stars. In the TeV regime no searches for emission from theses objects have been published so far, the study presented here is the first in this energy regime. The level of the gamma-ray emission from bow shocks of runaway stars is constrained by the calculated upper limits over six orders in magnitude in energy. The upper limits calculated for the bow shocks of runaway stars in the course of this work, constrain several models. For the best candidate, ζ Ophiuchi, the upper limits in the Fermi-LAT energy range are lower than the predictions by a factor ~5. This challenges the assumptions made in this model and gives valuable input for further modelling approaches. The analyses were performed with the software packages provided by the H.E.S.S. and Fermi collaborations. The development of a unified analysis framework for gamma-ray data, namely GammaLib/ctools, is rapidly progressing within the CTA consortium. Recent implementations and cross-checks with current software frameworks are presented in the Appendix.},
  language  = {en}
}
@phdthesis{Schultheiss2014,
  author    = {Schultheiss, Corinna},
  title     = {Die Bewertung der pharyngalen Schluckphase mittels Bioimpedanz},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-284-1},
  issn      = {1869-3822},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69589},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XV, 108},
  year      = {2014},
  abstract  = {Schlucken ist ein lebensnotwendiger Prozess, dessen Diagnose und Therapie eine enorme Herausforderung bedeutet. Die Erkennung und Beurteilung von Schlucken und Schluckst{\"o}rungen erfordert den Einsatz von technisch aufwendigen Verfahren, wie Videofluoroskopie (VFSS) und fiberoptisch-endoskopische Schluckuntersuchung (FEES), die eine hohe Belastung f{\"u}r die Patienten darstellen. Beide Verfahren werden als Goldstandard in der Diagnostik von Schluckst{\"o}rungen eingesetzt. Die Durchf{\"u}hrung obliegt in der Regel {\"a}rztlichem Personal. Dar{\"u}ber hinaus erfordert die Auswertung des Bildmaterials der Diagnostik eine ausreichend hohe Erfahrung. In der Therapie findet neben den klassischen Therapiemethoden, wie z.B. di{\"a}tetische Modifikationen und Schluckman{\"o}ver, auch zunehmend die funktionelle Elektrostimulation Anwendung. Ziel der vorliegenden Dissertationsschrift ist die Evaluation eines im Verbundprojekt BigDysPro entwickelten Bioimpedanz (BI)- und Elektromyographie (EMG)-Messsystems. Es wurde gepr{\"u}ft, ob sich das BI- und EMG-Messsystem eignet, sowohl in der Diagnostik als auch in der Therapie als eigenst{\"a}ndiges Messsystem und im Rahmen einer Schluckneuroprothese eingesetzt zu werden. In verschiedenen Studien wurden gesunde Probanden f{\"u}r die {\"U}berpr{\"u}fung der Reproduzierbarkeit (Intra-und Interrater-Reliabilit{\"a}t), der Unterscheidbarkeit von Schluck- und Kopfbewegungen und der Beeinflussung der Biosignale (BI, EMG) durch verschiedene Faktoren (Geschlecht der Probanden, Leitf{\"a}higkeit, Konsistenz und Menge der Nahrung) untersucht. Durch zus{\"a}tzliche Untersuchungen mit Patienten wurde einerseits der Einfluss der Elektrodenart gepr{\"u}ft. Andererseits wurden parallel zur BI- und EMG-Messung auch endoskopische (FEES) und radiologische Schluckuntersuchungen (VFSS) durchgef{\"u}hrt, um die Korrelation der Biosignale mit der Bewegung anatomischer Strukturen (VFSS) und mit der Schluckqualit{\"a}t (FEES) zu pr{\"u}fen. Es wurden 31 gesunde Probanden mit 1819 Schlucken und 60 Patienten mit 715 Schlucken untersucht. Die Messkurven zeigten einen typischen, reproduzierbaren Signalverlauf, der mit anatomischen und funktionellen {\"A}nderungen w{\"a}hrend der pharyngalen Schluckphase in der VFSS korrelierte (r > 0,7). Aus dem Bioimpedanzsignal konnten Merkmale extrahiert werden, die mit physiologischen Merkmalen eines Schluckes, wie verz{\"o}gerter laryngealer Verschluss und Kehlkopfhebung, korrelierten und eine Einsch{\"a}tzung der Schluckqualit{\"a}t in {\"U}bereinstimmung mit der FEES erm{\"o}glichten. In den Signalverl{\"a}ufen der Biosignale konnten signifikante Unterschiede zwischen Schluck- und Kopfbewegungen und den Nahrungsmengen und -konsistenzen nachgewiesen werden. Im Gegensatz zur Nahrungsmenge und -konsistenz zeigte die Leitf{\"a}higkeit der zu schluckenden Nahrung, das Geschlecht der Probanden und die Art der Elektroden keinen signifikanten Einfluss auf die Messsignale. Mit den Ergebnissen der Evaluation konnte gezeigt werden, dass mit dem BI- und EMG-Messsystem ein neuartiges und nicht-invasives Verfahren zur Verf{\"u}gung steht, das eine reproduzierbare Darstellung der pharyngalen Schluckphase und ihrer Ver{\"a}nderungen erm{\"o}glicht. Daraus ergeben sich vielseitige Einsatzm{\"o}glichkeiten in der Diagnostik, z.B. Langzeitmessung zur Schluckfrequenz und Einsch{\"a}tzung der Schluckqualit{\"a}t, und in der Therapie, z.B. der Einsatz in einer Schluckneuroprothese oder als Biofeedback zur Darstellung des Schluckes, von Schluckst{\"o}rungen.},
  language  = {de}
}
@phdthesis{Schubert2014,
  author    = {Schubert, Marcel},
  title     = {Elementary processes in layers of electron transporting Donor-acceptor copolymers : investigation of charge transport and application to organic solar cells},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70791},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Donor-acceptor (D-A) copolymers have revolutionized the field of organic electronics over the last decade. Comprised of a electron rich and an electron deficient molecular unit, these copolymers facilitate the systematic modification of the material's optoelectronic properties. The ability to tune the optical band gap and to optimize the molecular frontier orbitals as well as the manifold of structural sites that enable chemical modifications has created a tremendous variety of copolymer structures. Today, these materials reach or even exceed the performance of amorphous inorganic semiconductors. Most impressively, the charge carrier mobility of D-A copolymers has been pushed to the technologically important value of 10 cm^{2}V^{-1}s^{-1}. Furthermore, owed to their enormous variability they are the material of choice for the donor component in organic solar cells, which have recently surpassed the efficiency threshold of 10\%. Because of the great number of available D-A copolymers and due to their fast chemical evolution, there is a significant lack of understanding of the fundamental physical properties of these materials. Furthermore, the complex chemical and electronic structure of D-A copolymers in combination with their semi-crystalline morphology impede a straightforward identification of the microscopic origin of their superior performance. In this thesis, two aspects of prototype D-A copolymers were analysed. These are the investigation of electron transport in several copolymers and the application of low band gap copolymers as acceptor component in organic solar cells. In the first part, the investigation of a series of chemically modified fluorene-based copolymers is presented. The charge carrier mobility varies strongly between the different derivatives, although only moderate structural changes on the copolymers structure were made. Furthermore, rather unusual photocurrent transients were observed for one of the copolymers. Numerical simulations of the experimental results reveal that this behavior arises from a severe trapping of electrons in an exponential distribution of trap states. Based on the comparison of simulation and experiment, the general impact of charge carrier trapping on the shape of photo-CELIV and time-of-flight transients is discussed. In addition, the high performance naphthalenediimide (NDI)-based copolymer P(NDI2OD-T2) was characterized. It is shown that the copolymer posses one of the highest electron mobilities reported so far, which makes it attractive to be used as the electron accepting component in organic photovoltaic cells.\par Solar cells were prepared from two NDI-containing copolymers, blended with the hole transporting polymer P3HT. I demonstrate that the use of appropriate, high boiling point solvents can significantly increase the power conversion efficiency of these devices. Spectroscopic studies reveal that the pre-aggregation of the copolymers is suppressed in these solvents, which has a strong impact on the blend morphology. Finally, a systematic study of P3HT:P(NDI2OD-T2) blends is presented, which quantifies the processes that limit the efficiency of devices. The major loss channel for excited states was determined by transient and steady state spectroscopic investigations: the majority of initially generated electron-hole pairs is annihilated by an ultrafast geminate recombination process. Furthermore, exciton self-trapping in P(NDI2OD-T2) domains account for an additional reduction of the efficiency. The correlation of the photocurrent to microscopic morphology parameters was used to disclose the factors that limit the charge generation efficiency. Our results suggest that the orientation of the donor and acceptor crystallites relative to each other represents the main factor that determines the free charge carrier yield in this material system. This provides an explanation for the overall low efficiencies that are generally observed in all-polymer solar cells.},
  language  = {en}
}
@phdthesis{Schollaen2014,
  author    = {Schollaen, Karina},
  title     = {Tracking climate signals in tropical trees},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71947},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {The tropical warm pool waters surrounding Indonesia are one of the equatorial heat and moisture sources that are considered as a driving force of the global climate system. The climate in Indonesia is dominated by the equatorial monsoon system, and has been linked to El Ni{\~n}o-Southern Oscillation (ENSO) events, which often result in severe droughts or floods over Indonesia with profound societal and economic impacts on the populations living in the world's fourth most populated country. The latest IPCC report states that ENSO will remain the dominant mode in the tropical Pacific with global effects in the 21st century and ENSO-related precipitation extremes will intensify. However, no common agreement exists among climate simulation models for projected change in ENSO and the Australian-Indonesian Monsoon. Exploring high-resolution palaeoclimate archives, like tree rings or varved lake sediments, provide insights into the natural climate variability of the past, and thus helps improving and validating simulations of future climate changes. Centennial tree-ring stable isotope records | Within this doctoral thesis the main goal was to explore the potential of tropical tree rings to record climate signals and to use them as palaeoclimate proxies. In detail, stable carbon (δ13C) and oxygen (δ18O) isotopes were extracted from teak trees in order to establish the first well-replicated centennial (AD 1900-2007) stable isotope records for Java, Indonesia. Furthermore, different climatic variables were tested whether they show significant correlation with tree-ring proxies (ring-width, δ13C, δ18O). Moreover, highly resolved intra-annual oxygen isotope data were established to assess the transfer of the seasonal precipitation signal into the tree rings. Finally, the established oxygen isotope record was used to reveal possible correlations with ENSO events. Methodological achievements | A second goal of this thesis was to assess the applicability of novel techniques which facilitate and optimize high-resolution and high-throughput stable isotope analysis of tree rings. Two different UV-laser-based microscopic dissection systems were evaluated as a novel sampling tool for high-resolution stable isotope analysis. Furthermore, an improved procedure of tree-ring dissection from thin cellulose laths for stable isotope analysis was designed. The most important findings of this thesis are: I) The herein presented novel sampling techniques improve stable isotope analyses for tree-ring studies in terms of precision, efficiency and quality. The UV-laser-based microdissection serve as a valuable tool for sampling plant tissue at ultrahigh-resolution and for unprecedented precision. II) A guideline for a modified method of cellulose extraction from wholewood cross-sections and subsequent tree-ring dissection was established. The novel technique optimizes the stable isotope analysis process in two ways: faster and high-throughput cellulose extraction and precise tree-ring separation at annual to high-resolution scale. III) The centennial tree-ring stable isotope records reveal significant correlation with regional precipitation. High-resolution stable oxygen values, furthermore, allow distinguishing between dry and rainy season rainfall. IV) The δ18O record reveals significant correlation with different ENSO flavors and demonstrates the importance of considering ENSO flavors when interpreting palaeoclimatic data in the tropics. The findings of my dissertation show that seasonally resolved δ18O records from Indonesian teak trees are a valuable proxy for multi-centennial reconstructions of regional precipitation variability (monsoon signals) and large-scale ocean-atmosphere phenomena (ENSO) for the Indo-Pacific region. Furthermore, the novel methodological achievements offer many unexplored avenues for multidisciplinary research in high-resolution palaeoclimatology.},
  language  = {en}
}
@phdthesis{Schmitt2014,
  author    = {Schmitt, Clemens Nikolaus Zeno},
  title     = {The role of protein metal complexes in the mechanics of Mytilus californianus byssal threads},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-74216},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VIII, 93},
  year      = {2014},
  abstract  = {Protein-metal coordination complexes are well known as active centers in enzymatic catalysis, and to contribute to signal transduction, gas transport, and to hormone function. Additionally, they are now known to contribute as load-bearing cross-links to the mechanical properties of several biological materials, including the jaws of Nereis worms and the byssal threads of marine mussels. The primary aim of this thesis work is to better understand the role of protein-metal cross-links in the mechanical properties of biological materials, using the mussel byssus as a model system. Specifically, the focus is on histidine-metal cross-links as sacrificial bonds in the fibrous core of the byssal thread (Chapter 4) and L-3,4-dihydroxyphenylalanine (DOPA)-metal bonds in the protective thread cuticle (Chapter 5). Byssal threads are protein fibers, which mussels use to attach to various substrates at the seashore. These relatively stiff fibers have the ability to extend up to about 100 \% strain, dissipating large amounts of mechanical energy from crashing waves, for example. Remarkably, following damage from cyclic loading, initial mechanical properties are subsequently recovered by a material-intrinsic self-healing capability. Histidine residues coordinated to transition metal ions in the proteins comprising the fibrous thread core have been suggested as reversible sacrificial bonds that contribute to self-healing; however, this remains to be substantiated in situ. In the first part of this thesis, the role of metal coordination bonds in the thread core was investigated using several spectroscopic methods. In particular, X-ray absorption spectroscopy (XAS) was applied to probe the coordination environment of zinc in Mytilus californianus threads at various stages during stretching and subsequent healing. Analysis of the extended X-ray absorption fine structure (EXAFS) suggests that tensile deformation of threads is correlated with the rupture of Zn-coordination bonds and that self-healing is connected with the reorganization of Zn-coordination bond topologies rather than the mere reformation of Zn-coordination bonds. These findings have interesting implications for the design of self-healing metallopolymers. The byssus cuticle is a protective coating surrounding the fibrous thread core that is both as hard as an epoxy and extensible up to 100 \% strain before cracking. It was shown previously that cuticle stiffness and hardness largely depend on the presence of Fe-DOPA coordination bonds. However, the byssus is known to concentrate a large variety of metals from seawater, some of which are also capable of binding DOPA (e.g. V). Therefore, the question arises whether natural variation of metal composition can affect the mechanical performance of the byssal thread cuticle. To investigate this hypothesis, nanoindentation and confocal Raman spectroscopy were applied to the cuticle of native threads, threads with metals removed (EDTA treated), and threads in which the metal ions in the native tissue were replaced by either Fe or V. Interestingly, replacement of metal ions with either Fe or V leads to the full recovery of native mechanical properties with no statistical difference between each other or the native properties. This likely indicates that a fixed number of metal coordination sites are maintained within the byssal thread cuticle - possibly achieved during thread formation - which may provide an evolutionarily relevant mechanism for maintaining reliable mechanics in an unpredictable environment. While the dynamic exchange of bonds plays a vital role in the mechanical behavior and self-healing in the thread core by allowing them to act as reversible sacrificial bonds, the compatibility of DOPA with other metals allows an inherent adaptability of the thread cuticle to changing circumstances. The requirements to both of these materials can be met by the dynamic nature of the protein-metal cross-links, whereas covalent cross-linking would fail to provide the adaptability of the cuticle and the self-healing of the core. In summary, these studies of the thread core and the thread cuticle serve to underline the important and dynamic roles of protein-metal coordination in the mechanical function of load-bearing protein fibers, such as the mussel byssus.},
  language  = {en}
}
@phdthesis{Schmidt2014,
  author    = {Schmidt, Lukas},
  title     = {Aerosols and boundary layer structure over Arctic sea ice based on airborne lidar and dropsonde measurements},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-75076},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vii, 98, xiii},
  year      = {2014},
  abstract  = {The atmosphere over the Arctic Ocean is strongly influenced by the distribution of sea ice and open water. Leads in the sea ice produce strong convective fluxes of sensible and latent heat and release aerosol particles into the atmosphere. They increase the occurrence of clouds and modify the structure and characteristics of the atmospheric boundary layer (ABL) and thereby influence the Arctic climate. In the course of this study aircraft measurements were performed over the western Arctic Ocean as part of the campaign PAMARCMIP 2012 of the Alfred Wegener Institute for Polar and Marine Research (AWI). Backscatter from aerosols and clouds within the lower troposphere and the ABL were measured with the nadir pointing Airborne Mobile Aerosol Lidar (AMALi) and dropsondes were launched to obtain profiles of meteorological variables. Furthermore, in situ measurements of aerosol properties, meteorological variables and turbulence were part of the campaign. The measurements covered a broad range of atmospheric and sea ice conditions. In this thesis, properties of the ABL over Arctic sea ice with a focus on the influence of open leads are studied based on the data from the PAMARCMIP campaign. The height of the ABL is determined by different methods that are applied to dropsonde and AMALi backscatter profiles. ABL heights are compared for different flights representing different conditions of the atmosphere and of sea ice and open water influence. The different criteria for ABL height that are applied show large variation in terms of agreement among each other, depending on the characteristics of the ABL and its history. It is shown that ABL height determination from lidar backscatter by methods commonly used under mid-latitude conditions is applicable to the Arctic ABL only under certain conditions. Aerosol or clouds within the ABL are needed as a tracer for ABL height detection from backscatter. Hence an aerosol source close to the surface is necessary, that is typically found under the present influence of open water and therefore convective conditions. However it is not always possible to distinguish residual layers from the actual ABL. Stable boundary layers are generally difficult to detect. To illustrate the complexity of the Arctic ABL and processes therein, four case studies are analyzed each of which represents a snapshot of the interplay between atmosphere and underlying sea ice or water surface. Influences of leads and open water on the aerosol and clouds within the ABL are identified and discussed. Leads are observed to cause the formation of fog and cloud layers within the ABL by humidity emission. Furthermore they decrease the stability and increase the height of the ABL and consequently facilitate entrainment of air and aerosol layers from the free troposphere.},
  language  = {en}
}
@phdthesis{Schmidl2014,
  author    = {Schmidl, Ricarda},
  title     = {Empirical essays on job search behavior, active labor market policies, and propensity score balancing methods},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71145},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {In Chapter 1 of the dissertation, the role of social networks is analyzed as an important determinant in the search behavior of the unemployed. Based on the hypothesis that the unemployed generate information on vacancies through their social network, search theory predicts that individuals with large social networks should experience an increased productivity of informal search, and reduce their search in formal channels. Due to the higher productivity of search, unemployed with a larger network are also expected to have a higher reservation wage than unemployed with a small network. The model-theoretic predictions are tested and confirmed empirically. It is found that the search behavior of unemployed is significantly affected by the presence of social contacts, with larger networks implying a stronger substitution away from formal search channels towards informal channels. The substitution is particularly pronounced for passive formal search methods, i.e., search methods that generate rather non-specific types of job offer information at low relative cost. We also find small but significant positive effects of an increase of the network size on the reservation wage. These results have important implications on the analysis of the job search monitoring or counseling measures that are usually targeted at formal search only. Chapter 2 of the dissertation addresses the labor market effects of vacancy information during the early stages of unemployment. The outcomes considered are the speed of exit from unemployment, the effects on the quality of employment and the short-and medium-term effects on active labor market program (ALMP) participation. It is found that vacancy information significantly increases the speed of entry into employment; at the same time the probability to participate in ALMP is significantly reduced. Whereas the long-term reduction in the ALMP arises in consequence of the earlier exit from unemployment, we also observe a short-run decrease for some labor market groups which suggest that caseworker use high and low intensity activation measures interchangeably which is clearly questionable from an efficiency point of view. For unemployed who find a job through vacancy information we observe a small negative effect on the weekly number of hours worked. In Chapter 3, the long-term effects of participation in ALMP are assessed for unemployed youth under 25 years of age. Complementary to the analysis in Chapter 2, the effects of participation in time- and cost-intensive measures of active labor market policies are examined. In particular we study the effects of job creation schemes, wage subsidies, short-and long-term training measures and measures to promote the participation in vocational training. The outcome variables of interest are the probability to be in regular employment, and participation in further education during the 60 months following program entry. The analysis shows that all programs, except job creation schemes have positive and long-term effects on the employment probability of youth. In the short-run only short-term training measures generate positive effects, as long-term training programs and wage subsidies exhibit significant locking-in'' effects. Measures to promote vocational training are found to increase the probability of attending education and training significantly, whereas all other programs have either no or a negative effect on training participation. Effect heterogeneity with respect to the pre-treatment level education shows that young people with higher pre-treatment educational levels benefit more from participation most programs. However, for longer-term wage subsidies we also find strong positive effects for young people with low initial education levels. The relative benefit of training measures is higher in West than in East Germany. In the evaluation studies of Chapters 2 and 3 semi-parametric balancing methods of Propensity Score Matching (PSM) and Inverse Probability Weighting (IPW) are used to eliminate the effects of counfounding factors that influence both the treatment participation as well as the outcome variable of interest, and to establish a causal relation between program participation and outcome differences. While PSM and IPW are intuitive and methodologically attractive as they do not require parametric assumptions, the practical implementation may become quite challenging due to their sensitivity to various data features. Given the importance of these methods in the evaluation literature, and the vast number of recent methodological contributions in this field, Chapter 4 aims to reduce the knowledge gap between the methodological and applied literature by summarizing new findings of the empirical and statistical literature and practical guidelines for future applied research. In contrast to previous publications this study does not only focus on the estimation of causal effects, but stresses that the balancing challenge can and should be discussed independent of question of causal identification of treatment effects on most empirical applications. Following a brief outline of the practical implementation steps required for PSM and IPW, these steps are presented in detail chronologically, outlining practical advice for each step. Subsequently, the topics of effect estimation, inference, sensitivity analysis and the combination with parametric estimation methods are discussed. Finally, new extensions of the methodology and avenues for future research are presented.},
  language  = {en}
}
@phdthesis{Schipper2014,
  author    = {Schipper, Florian},
  title     = {Biomass derived carbon for new energy storage technologies},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72045},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {The thesis deals with the production and evaluation of porous carbon materials for energy storage technologies, namely super capacitors and lithium sulfur batteries.},
  language  = {de}
}
@phdthesis{Scheinemann2014,
  author    = {Scheinemann, Hendrik Alexander},
  title     = {Hygienisierung von Rinderg{\"u}lle und Kl{\"a}rschl{\"a}mmen mittels milchsaurer Fermentation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-77949},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xviii, 172},
  year      = {2014},
  abstract  = {Tierische und menschliche F{\"a}kalien aus Landwirtschaft und Haushalten enthalten zahlreiche obligat und opportunistisch pathogene Mikroorganismen, deren Konzentration u. a. je nach Gesundheitszustand der betrachteten Gruppe schwankt. Neben den Krankheitserregern enthalten F{\"a}kalien aber auch essentielle Pflanzenn{\"a}hrstoffe (276) und dienen seit Jahrtausenden (63) als D{\"u}nger f{\"u}r Feldfr{\"u}chte. Mit der unbedarften Verwendung von pathogenbelastetem F{\"a}kald{\"u}nger steigt jedoch auch das Risiko einer Infektion von Mensch und Tier. Diese Gefahr erh{\"o}ht sich mit der globalen Vernetzung der Landwirtschaft, z. B. durch den Import von kontaminierten Futter- bzw. Lebensmitteln (29). Die vorliegende Arbeit stellt die milchsaure Fermentation von Rinderg{\"u}lle und Kl{\"a}rschlamm als alternative Hygienisierungsmethode gegen{\"u}ber der Pasteurisation in Biogasanlagen bzw. gebr{\"a}uchlichen Kompostierung vor. Dabei wird ein Abfall der Gram-negativen Bakterienflora sowie der Enterokokken, Schimmel- und Hefepilze unter die Nachweisgrenze von 3 log10KbE/g beobachtet, gleichzeitig steigt die Konzentration der Lactobacillaceae um das Tausendfache. Dar{\"u}ber hinaus wird gezeigt, dass pathogene Bakterien wie Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, EHEC O:157 und vegetative Clostridum perfringens-Zellen innerhalb von 3 Tagen inaktiviert werden. Die Inaktivierung von ECBO-Viren und Spulwurmeiern erfolgt innerhalb von 7 bzw. 56 Tagen. Zur Aufkl{\"a}rung der Ursache der beobachteten Hygienisierung wurde das fermentierte Material auf fl{\"u}chtige Fetts{\"a}uren sowie pH-Wert{\"a}nderungen untersucht. Es konnte festgestellt werden, dass die gemessenen Werte nicht die alleinige Ursache f{\"u}r das Absterben der Erreger sind, vielmehr wird eine zus{\"a}tzliche bakterizide Wirkung durch eine mutmaßliche Bildung von Bakteriozinen in Betracht gezogen. Die parasitizide Wirkung wird auf die physikalischen Bedingungen der Fermentation zur{\"u}ckgef{\"u}hrt. Die methodischen Grundlagen basieren auf Analysen mittels zahlreicher klassisch-kultureller Verfahren, wie z. B. der Lebendkeimzahlbestimmung. Dar{\"u}ber hinaus findet die MALDI-TOF-Massenspektrometrie und die klassische PCR in Kombination mit der Gradienten-Gelelektrophorese Anwendung, um kultivierbare Bakterienfloren zu beschreiben bzw. nicht kultivierbare Bakterienfloren stichprobenartig zu erfassen. Neben den Aspekten der Hygienisierung wird zudem die Eignung der Methode f{\"u}r die landwirtschaftliche Nutzung ber{\"u}cksichtigt. Dies findet sich insbesondere in der Komposition des zu fermentierenden Materials wieder, welches f{\"u}r die verst{\"a}rkte Humusakkumulation im Ackerboden optimiert wurde. Dar{\"u}ber hinaus wird die Masseverlustbilanz w{\"a}hrend der milchsauren Fermentation mit denen der Kompostierung sowie der Verarbeitung in der Biogasanlage verglichen und als positiv bewertet, da sie mit insgesamt 2,45 \% sehr deutlich unter den bisherigen Alternativen liegt (73, 138, 458). Weniger Verluste an organischem Material w{\"a}hrend der Hygienisierung f{\"u}hren zu einer gr{\"o}ßeren verwendbaren D{\"u}ngermenge, die auf Grund ihres organischen Ursprungs zu einer Verst{\"a}rkung des Humusanteiles im Ackerboden beitragen kann (56, 132).},
  language  = {de}
}
@phdthesis{Schaefer2014,
  author    = {Schaefer, Laura},
  title     = {Synchronisationsph{\"a}nomene myotendin{\"o}ser Oszillationen interagierender neuromuskul{\"a}rer Systeme},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72445},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Muskeln oszillieren nachgewiesener Weise mit einer Frequenz um 10 Hz. Doch was geschieht mit myofaszialen Oszillationen, wenn zwei neuromuskul{\"a}re Systeme interagieren? Die Dissertation widmet sich dieser Fragestellung bei isometrischer Interaktion. W{\"a}hrend der Testmessungen ergaben sich Hinweise f{\"u}r das Vorhandensein von m{\"o}glicherweise zwei verschiedenen Formen der Isometrie. Arbeiten zwei Personen isometrisch gegeneinander, k{\"o}nnen subjektiv zwei Modi eingenommen werden: man kann entweder isometrisch halten - der Kraft des Partners widerstehen - oder isometrisch dr{\"u}cken - gegen den isometrischen Widerstand des Partners arbeiten. Daher wurde zus{\"a}tzlich zu den Messungen zur Interaktion zweier Personen an einzelnen Individuen gepr{\"u}ft, ob m{\"o}glicherweise zwei Formen der Isometrie existieren. Die Promotion besteht demnach aus zwei inhaltlich und methodisch getrennten Teilen: I „Single-Isometrie" und II „Paar-Isometrie". F{\"u}r Teil I wurden mithilfe eines pneumatisch betriebenen Systems die hypothetischen Messmodi Halten und Dr{\"u}cken w{\"a}hrend isometrischer Aktion untersucht. Bei n = 10 Probanden erfolgte parallel zur Aufzeichnung des Drucksignals w{\"a}hrend der Messungen die Erfassung der Kraft (DMS) und der Beschleunigung sowie die Aufnahme der mechanischen Muskeloszillationen folgender myotendin{\"o}ser Strukturen via Mechanomyo- (MMG) bzw. Mechanotendografie (MTG): M. triceps brachii (MMGtri), Trizepssehne (MTGtri), M. obliquus externus abdominis (MMGobl). Pro Proband wurden bei 80 \% der MVC sowohl sechs 15-Sekunden-Messungen (jeweils drei im haltenden bzw. dr{\"u}ckenden Modus; Pause: 1 Minute) als auch vier Erm{\"u}dungsmessungen (jeweils zwei im haltenden bzw. dr{\"u}ckenden Modus; Pause: 2 Minuten) durchgef{\"u}hrt. Zum Vergleich der Messmodi Halten und Dr{\"u}cken wurden die Amplituden der myofaszialen Oszillationen sowie die Kraftausdauer herangezogen. Signifikante Unterschiede zwischen dem haltenden und dem dr{\"u}ckenden Modus zeigten sich insbesondere im Bereich der Erm{\"u}dungscharakteristik. So lassen Probanden im haltenden Modus signifikant fr{\"u}her nach als im dr{\"u}ckenden Modus (t(9) = 3,716; p = .005). Im dr{\"u}ckenden Modus macht das l{\"a}ngste isometrische Plateau durchschnittlich 59,4 \% der Gesamtdauer aus, im haltenden sind es 31,6 \% (t(19) = 5,265, p = .000). Die Amplituden der Single-Isometrie-Messungen unterscheiden sich nicht signifikant. Allerdings variieren die Amplituden des MMGobl zwischen den Messungen im dr{\"u}ckenden Modus signifikant st{\"a}rker als im haltenden Modus. Aufgrund dieser teils signifikanten Unterschiede zwischen den beiden Messmodi wurde dieses Setting auch im zweiten Teil „Paar-Isometrie" ber{\"u}cksichtigt. Dort wurden n = 20 Probanden - eingeteilt in zehn gleichgeschlechtliche Paare - w{\"a}hrend isometrischer Interaktion untersucht. Die Sensorplatzierung erfolgte analog zu Teil I. Die Oszillationen der erfassten MTG- sowie MMG-Signale wurden u.a. mit Algorithmen der Nichtlinearen Dynamik auf ihre Koh{\"a}renz hin untersucht. Durch die Paar-Isometrie-Messungen zeigte sich, dass die Muskeln und die Sehnen beider neuromuskul{\"a}rer Systeme bei Interaktion im bekannten Frequenzbereich von 10 Hz oszillieren. Außerdem waren sie in der Lage, sich bei Interaktion so aufeinander abzustimmen, dass sich eine signifikante Koh{\"a}renz entwickelte, die sich von Zufallspaarungen signifikant unterscheidet (Patchanzahl: t(29) = 3,477; p = .002; Summe der 4 l{\"a}ngsten Patches: t(29) = 7,505; p = .000). Es wird der Schluss gezogen, dass neuromuskul{\"a}re Komplement{\"a}rpartner in der Lage sind, sich im Sinne koh{\"a}renten Verhaltens zu synchronisieren. Bez{\"u}glich der Parameter zur Untersuchung der m{\"o}glicherweise vorhandenen zwei Formen der Isometrie zeigte sich bei den Paar-Isometrie-Messungen zwischen Halten und Dr{\"u}cken ein signifikanter Unterschied bei der Erm{\"u}dungscharakteristik sowie bez{\"u}glich der Amplitude der MMGobl. Die Ergebnisse beider Teilstudien best{\"a}rken die Hypothese, dass zwei Formen der Isometrie existieren. Fraglich ist, ob man {\"u}berhaupt von Isometrie sprechen kann, da jede isometrische Muskelaktion aus feinen Oszillationen besteht, die eine per Definition postulierte Isometrie ausschließen. Es wird der Vorschlag unterbreitet, die Isometrie durch den Begriff der Hom{\"o}ometrie auszutauschen. Die Ergebnisse der Paar-Isometrie-Messungen zeigen u.a., dass neuromuskul{\"a}re Systeme in der Lage sind, ihre myotendin{\"o}sen Oszillationen so aufeinander abzustimmen, dass koh{\"a}rentes Verhalten entsteht. Es wird angenommen, dass hierzu beide neuromuskul{\"a}ren Systeme funktionell intakt sein m{\"u}ssen. Das Verfahren k{\"o}nnte f{\"u}r die Diagnostik funktioneller St{\"o}rungen relevant werden.},
  language  = {de}
}
@phdthesis{Sayago2014,
  author    = {Sayago, Jhosnella},
  title     = {Late Paleozoic basin analysis of the Loppa High and Finnmark Platform in the Norwegian Barents Sea : integration of seismic attributes and seismic sequence stratigraphy},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72576},
  school      = {Universit{\"a}t Potsdam},
  pages     = {viii, 109},
  year      = {2014},
  abstract  = {The subsurface upper Palaeozoic sedimentary successions of the Loppa High half-graben and the Finnmark platform in the Norwegian Barents Sea (southwest Barents Sea) were investigated using 2D/3D seismic datasets combined with well and core data. These sedimentary successions represent a case of mixed siliciclastic-carbonates depositional systems, which formed during the earliest phase of the Atlantic rifting between Greenland and Norway. During the Carboniferous and Permian the southwest part of the Barents Sea was located along the northern margin of Pangaea, which experienced a northward drift at a speed of ~2-3 mm per year. This gradual shift in the paleolatitudinal position is reflected by changes in regional climatic conditions: from warm-humid in the early Carboniferous, changing to warm-arid in the middle to late Carboniferous and finally to colder conditions in the late Permian. Such changes in paleolatitude and climate have resulted in major changes in the style of sedimentation including variations in the type of carbonate factories. The upper Palaeozoic sedimentary succession is composed of four major depositional units comprising chronologically the Billefjorden Group dominated by siliciclastic deposition in extensional tectonic-controlled wedges, the Gipsdalen Group dominated by warm-water carbonates, stacked buildups and evaporites, the Bjarmeland Group characterized by cool-water carbonates as well as by the presence of buildup networks, and the Tempelfjorden Group characterized by fine-grained sedimentation dominated by biological silica production. In the Loppa High, the integration of a core study with multi-attribute seismic facies classification allowed highlighting the main sedimentary unconformities and mapping the spatial extent of a buried paleokarst terrain. This geological feature is interpreted to have formed during a protracted episode of subaerial exposure occurring between the late Palaeozoic and middle Triassic. Based on seismic sequence stratigraphy analysis the palaeogeography in time and space of the Loppa High basin was furthermore reconstructed and a new and more detailed tectono-sedimentary model for this area was proposed. In the Finnmark platform area, a detailed core analysis of two main exploration wells combined with key 2D seismic sections located along the main depositional profile, allowed the evaluation of depositional scenarios for the two main lithostratigraphic units: the {\O}rn Formation (Gipsdalen Group) and the Isbj{\o}rn Formation (Bjarmeland Group). During the mid-Sakmarian, two major changes were observed between the two formations including (1) the variation in the type of the carbonate factories, which is interpreted to be depth-controlled and (2) the change in platform morphology, which evolved from a distally steepened ramp to a homoclinal ramp. The results of this study may help supporting future reservoirs characterization of the upper Palaeozoic units in the Barents Sea, particularly in the Loppa High half-graben and the Finmmark platform area.},
  language  = {en}
}
@phdthesis{Sarrar2014,
  author    = {Sarrar, Lea},
  title     = {Kognitive Funktionen bei adoleszenten Patienten mit Anorexia nervosa und unipolaren Affektiven St{\"o}rungen},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72439},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Anorexia nervosa und unipolare Affektive St{\"o}rungen stellen h{\"a}ufige und schwerwiegende kinder- und jugendpsychiatrische St{\"o}rungsbilder dar, deren Pathogenese bislang nicht vollst{\"a}ndig entschl{\"u}sselt ist. Verschiedene Studien zeigen bei erwachsenen Patienten gravierende Auff{\"a}lligkeiten in den kognitiven Funktionen. Dahingegen scheinen bei adoleszenten Patienten lediglich leichtere Einschr{\"a}nkungen in den kognitiven Funktionen vorzuliegen. Die Pr{\"a}valenz der Anorexia nervosa und unipolaren Affektiven St{\"o}rung ist mit Beginn der Adoleszenz deutlich erh{\"o}ht. Es ist anzunehmen, dass kognitive Dysfunktionen, die sich bereits in diesem Alter abzeichnen, den weiteren Krankheitsverlauf bis in das Erwachsenenalter, die Behandlungsergebnisse und die Prognose maßgeblich beeintr{\"a}chtigen k{\"o}nnten. Zudem ist von einem h{\"o}heren Chronifizierungsrisiko auszugehen. In der vorliegenden Arbeit wurden daher kognitive Funktionen bei adoleszenten Patientinnen mit Anorexia nervosa sowie Patienten mit unipolaren Affektiven St{\"o}rungen untersucht. Die {\"U}berpr{\"u}fung der kognitiven Funktionen bei Patientinnen mit Anorexia nervosa erfolgte vor und nach Gewichtszunahme. Weiterhin wurden zugrundeliegende biologische Mechanismen {\"u}berpr{\"u}ft. Zudem wurde die Spezifit{\"a}t kognitiver Dysfunktionen f{\"u}r beide St{\"o}rungsbilder untersucht und bei Patienten mit unipolaren Affektiven St{\"o}rungen geschlechtsbezogene Unterschiede exploriert. Insgesamt gingen 47 Patientinnen mit Anorexia nervosa (mittleres Alter 16,3 + 1,6 Jahre), 39 Patienten mit unipolaren Affektiven St{\"o}rungen (mittleres Alter 15,5 + 1,3 Jahre) sowie 78 Kontrollprobanden (mittleres Alter 16,5 + 1,3 Jahre) in die Untersuchung ein. S{\"a}mtliche Studienteilnehmer durchliefen eine neuropsychologische Testbatterie, bestehend aus Verfahren zur {\"U}berpr{\"u}fung der kognitiven Flexibilit{\"a}t sowie visuellen und psychomotorischen Verarbeitungsgeschwindigkeit. Neben einem Intelligenzscreening wurden zudem das Ausmaß der depressiven Symptomatik sowie die allgemeine psychische Belastung erfasst. Die Ergebnisse legen nahe, dass bei adoleszenten Patientinnen mit Anorexia nervosa, sowohl im akut untergewichtigen Zustand als auch nach Gewichtszunahme, lediglich milde Beeintr{\"a}chtigungen in den kognitiven Funktionen vorliegen. Im akut untergewichtigen Zustand offenbarten sich deutliche Zusammenh{\"a}nge zwischen dem appetitregulierenden Peptid Agouti-related Protein und kognitiver Flexibilit{\"a}t, nicht jedoch zwischen Agouti-related Protein und visueller oder psychomotorischer Verarbeitungsgeschwindigkeit. Bei dem Vergleich von Anorexia nervosa und unipolaren Affektiven St{\"o}rungen pr{\"a}dizierte die Zugeh{\"o}rigkeit zu der Patientengruppe Anorexia nervosa ein Risiko f{\"u}r das Vorliegen kognitiver Dysfunktionen. Es zeigte sich zudem, dass adoleszente Patienten mit unipolaren Affektiven St{\"o}rungen lediglich in der psychomotorischen Verarbeitungsgeschwindigkeit tendenziell schw{\"a}chere Leistungen offenbarten als gesunde Kontrollprobanden. Es ergab sich jedoch ein genereller geschlechtsbezogener Vorteil f{\"u}r weibliche Probanden in der visuellen und psychomotorischen Verarbeitungsgeschwindigkeit. Die vorliegenden Befunde unterstreichen die Notwendigkeit der {\"U}berpr{\"u}fung kognitiver Funktionen bei adoleszenten Patienten mit Anorexia nervosa sowie unipolaren Affektiven St{\"o}rungen in der klinischen Routinediagnostik. Die Patienten k{\"o}nnten von spezifischen Therapieprogrammen profitieren, die Beeintr{\"a}chtigungen in den kognitiven Funktionen mildern bzw. pr{\"a}ventiv behandeln.},
  language  = {de}
}
@phdthesis{Sarkar2014,
  author    = {Sarkar, Saswati},
  title     = {Holocene variations in the strength of the Indian Monsoon system},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-74905},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ix, 114},
  year      = {2014},
  abstract  = {The monsoon is an important component of the Earth's climate system. It played a vital role in the development and sustenance of the largely agro-based economy in India. A better understanding of past variations in the Indian Summer Monsoon (ISM) is necessary to assess its nature under global warming scenarios. Instead, our knowledge of spatiotemporal patterns of past ISM strength, as inferred from proxy records, is limited due to the lack of high-resolution paleo-hydrological records from the core monsoon domain. In this thesis I aim to improve our understanding of Holocene ISM variability from the core 'monsoon zone' (CMZ) in India. To achieve this goal, I tried to understand modern and thereafter reconstruct Holocene monsoonal hydrology, by studying surface sediments and a high-resolution sedimentary record from the saline-alkaline Lonar crater lake, central India. My approach relies on analyzing stable carbon and hydrogen isotope ratios from sedimentary lipid biomarkers to track past hydrological changes. In order to evaluate the relationship of the modern ecosystem and hydrology of the lake I studied the distribution of lipid biomarkers in the modern ecosystem and compared it to lake surface sediments. The major plants from dry deciduous mixed forest type produced a greater amount of leaf wax n-alkanes and a greater fraction of n-C31 and n-C33 alkanes relative to n-C27 and n-C29. Relatively high average chain length (ACL) values (29.6-32.8) for these plants seem common for vegetation from an arid and warm climate. Additionally I found that human influence and subsequent nutrient supply result in increased lake primary productivity, leading to an unusually high concentration of tetrahymanol, a biomarker for salinity and water column stratification, in the nearshore sediments. Due to this inhomogeneous deposition of tetrahymanol in modern sediments, I hypothesize that lake level fluctuation may potentially affect aquatic lipid biomarker distributions in lacustrine sediments, in addition to source changes. I reconstructed centennial-scale hydrological variability associated with changes in the intensity of the ISM based on a record of leaf wax and aquatic biomarkers and their stable carbon (δ13C) and hydrogen (δD) isotopic composition from a 10 m long sediment core from the lake. I identified three main periods of distinct hydrology over the Holocene in central India. The period between 10.1 and 6 cal. ka BP was likely the wettest during the Holocene. Lower ACL index values (29.4 to 28.6) of leaf wax n-alkanes and their negative δ13C values (-34.8 per mille to -27.8 per mille) indicated the dominance of woody C3 vegetation in the catchment, and negative δDwax (average for leaf wax n-alkanes) values (-171 per mille to -147 per mille) argue for a wet period due to an intensified monsoon. After 6 cal. ka BP, a gradual shift to less negative δ13C values (particularly for the grass derived n-C31) and appearance of the triterpene lipid tetrahymanol, generally considered as a marker for salinity and water column stratification, marked the onset of drier conditions. At 5.1 cal. ka BP increasing flux of leaf wax n-alkanes along with the highest flux of tetrahymanol indicated proximity of the lakeshore to the center due to a major lake level decrease. Rapid fluctuations in abundance of both terrestrial and aquatic biomarkers between 4.8 and 4 cal. ka BP indicated an unstable lake ecosystem, culminating in a transition to arid conditions. A pronounced shift to less negative δ13C values, in particular for n-C31 (-25.2 per mille to -22.8 per mille), over this period indicated a change of dominant vegetation to C4 grasses. Along with a 40 per mille increase in leaf wax n-alkane δD values, which likely resulted from less rainfall and/or higher plant evapotranspiration, I interpret this period to reflect the driest conditions in the region during the last 10.1 ka. This transition led to protracted late Holocene arid conditions and the establishment of a permanently saline lake. This is supported by the high abundance of tetrahymanol. A late Holocene peak of cyanobacterial biomarker input at 1.3 cal. ka BP might represent an event of lake eutrophication, possibly due to human impact and the onset of cattle/livestock farming in the catchment. The most intriguing feature of the mid-Holocene driest period was the high amplitude and rapid fluctuations in δDwax values, probably due to a change in the moisture source and/or precipitation seasonality. I hypothesize that orbital induced weakening of the summer solar insolation and associated reorganization of the general atmospheric circulation were responsible for an unstable hydroclimate in the mid-Holocene in the CMZ. My findings shed light onto the sequence of changes during mean state changes of the monsoonal system, once an insolation driven threshold has been passed, and show that small changes in solar insolation can be associated to major environmental changes and large fluctuations in moisture source, a scenario that may be relevant with respect to future changes in the ISM system.},
  language  = {en}
}
@phdthesis{SahyaziciKnaak2014,
  author    = {Sahyazici-Knaak, Fidan},
  title     = {Dysfunktionale Einstellungen und Depression im Kindes- und Jugendalter},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-76417},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XVI, 264},
  year      = {2014},
  abstract  = {Die vorliegende Studie besch{\"a}ftigte sich mit der Bedeutung der dysfunktionalen Einstellungen f{\"u}r die Entwicklung von depressiven Symptomen bei Kindern und Jugendlichen. Nach der kognitiven Theorie der Depression von Beck (1967, 1996) f{\"u}hren dysfunktionale Einstellungen in Interaktion mit Stress zu depressiven Symptomen. Es existieren allerdings nur wenige Studien, die die longitudinale Beziehung zwischen den dysfunktionalen Einstellungen und der Depressivit{\"a}t bei Kindern und Jugendlichen untersucht haben (Lakdawalla et al., 2007). Folglich kann noch nicht eindeutig gekl{\"a}rt werden, ob die dysfunktionalen Einstellungen Ursache, Begleiterscheinung oder Konsequenz der Depression sind. Als Datengrundlage diente eine Stichprobe von Kindern und Jugendlichen im Alter von 9 bis 20 Jahren, die im Rahmen der PIER-Studie zu dysfunktionalen Einstellungen, kritischen Lebensereignissen und depressiven Symptomen befragt wurden (Nt1t2 = 1.053; t1: 2011/2012, t2: 2013/2014). Querschnittliche Analysen zeigten hohe Assoziationen zwischen den dysfunktionalen Einstellungen, kritischen Lebensereignissen und depressiven Symptomen. Eine latente Moderationsanalyse wies nur bei den Jugendlichen auf signifikante Interaktion zwischen den dysfunktionalen Einstellungen und den kritischen Lebensereignissen in der Vorhersage depressiver Symptomatik hin. Im L{\"a}ngsschnitt zeigten latente Cross-Lagged-Panel-Analysen erwartungsgem{\"a}ß, dass die dysfunktionalen Einstellungen und die Depressivit{\"a}t mit dem Alter immer stabilere Konstrukte darstellen, die sehr eng miteinander zusammenh{\"a}ngen. Eine diesem Modell hinzugef{\"u}gte latente Moderationsanalyse konnte das kognitive Modell der Depression nach Beck weder bei Kindern noch bei Jugendlichen best{\"a}tigen. Die sp{\"a}tere depressive Symptomatik konnte lediglich durch Haupteffekte der fr{\"u}heren Auspr{\"a}gung der Depressivit{\"a}t und der kritischen Lebensereignisse vorhergesagt werden. Diese Ergebnisse legen den Schluss nahe, dass es sich bei den dysfunktionalen Einstellungen eher um Begleiterscheinungen als um Risikofaktoren oder Konsequenzen der depressiven Symptomatik handelt.},
  language  = {de}
}
@phdthesis{RoggeSolti2014,
  author    = {Rogge-Solti, Andreas},
  title     = {Probabilistic Estimation of Unobserved Process Events},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70426},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Organizations try to gain competitive advantages, and to increase customer satisfaction. To ensure the quality and efficiency of their business processes, they perform business process management. An important part of process management that happens on the daily operational level is process controlling. A prerequisite of controlling is process monitoring, i.e., keeping track of the performed activities in running process instances. Only by process monitoring can business analysts detect delays and react to deviations from the expected or guaranteed performance of a process instance. To enable monitoring, process events need to be collected from the process environment. When a business process is orchestrated by a process execution engine, monitoring is available for all orchestrated process activities. Many business processes, however, do not lend themselves to automatic orchestration, e.g., because of required freedom of action. This situation is often encountered in hospitals, where most business processes are manually enacted. Hence, in practice it is often inefficient or infeasible to document and monitor every process activity. Additionally, manual process execution and documentation is prone to errors, e.g., documentation of activities can be forgotten. Thus, organizations face the challenge of process events that occur, but are not observed by the monitoring environment. These unobserved process events can serve as basis for operational process decisions, even without exact knowledge of when they happened or when they will happen. An exemplary decision is whether to invest more resources to manage timely completion of a case, anticipating that the process end event will occur too late. This thesis offers means to reason about unobserved process events in a probabilistic way. We address decisive questions of process managers (e.g., "when will the case be finished?", or "when did we perform the activity that we forgot to document?") in this thesis. As main contribution, we introduce an advanced probabilistic model to business process management that is based on a stochastic variant of Petri nets. We present a holistic approach to use the model effectively along the business process lifecycle. Therefore, we provide techniques to discover such models from historical observations, to predict the termination time of processes, and to ensure quality by missing data management. We propose mechanisms to optimize configuration for monitoring and prediction, i.e., to offer guidance in selecting important activities to monitor. An implementation is provided as a proof of concept. For evaluation, we compare the accuracy of the approach with that of state-of-the-art approaches using real process data of a hospital. Additionally, we show its more general applicability in other domains by applying the approach on process data from logistics and finance.},
  language  = {en}
}
@phdthesis{Riemer2014,
  author    = {Riemer, Martin},
  title     = {Vom Phenol zum Naturstoff : Entwicklung nachhaltiger Mikrowellen-vermittelter SUZUKI-MIYAURA-Kupplungen und Tandem-Reaktionen},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72525},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Ziel dieser Arbeit war die Entwicklung von Methoden zur Synthese von auf Phenol basierenden Naturstoffen. Insbesondere wurde bei der Methodenentwicklung die Nachhaltigkeit in den Vordergrund ger{\"u}ckt. Dies bedeutet, dass durch die Zusammenfassung mehrerer Syntheseschritte zu einem (Tandem-Reaktion) beispielsweise unn{\"o}tige Reaktionsschritte vermieden werden sollten. Ferner sollten im Sinne der Nachhaltigkeit m{\"o}glichst ungiftige Reagenzien und L{\"o}sungmittel verwendet werden, ebenso wie mehrfach wiederverwertbare Katalysatoren zum Einsatz kommen. Im Rahmen dieser Arbeit wurden Methoden zum Aufbau von Biphenolen mittels Pd/C-katalysierten Suzuki-Miyaura-Kupplungen entwickelt. Diese Methoden sind insofern {\"a}ußerst effizient, da der ansonsten gebr{\"a}uchliche Syntheseweg {\"u}ber drei Reaktionsschritte somit auf lediglich eine Reaktionsstufe reduziert wurde. Weiterhin wurden die Reaktionsbedingungen so gestaltet, dass einfaches Wasser als vollkommen ungiftiges L{\"o}sungsmittel verwendet werden konnte. Des Weiteren wurde f{\"u}r diese Reaktionen ein Katalysator gew{\"a}hlt, der einfach durch Filtration vom Reaktionsgemisch abgetrennt und f{\"u}r weitere Reaktionen mehrfach wiederverwendet werden konnte. Dar{\"u}ber hinaus konnte durch die Synthese von mehr als 100 Verbindungen die breite Anwendbarkeit der Methoden aufgezeigt werden. Mit den entwickelten Methoden konnten 14 Naturstoffe - z. T. erstmals - synthetisiert werden. Derartige Stoffe werden u. a. von den {\"o}konomisch bedeutenden Kernobstgew{\"a}chsen ({\"A}pfeln, Birnen) als Abwehrmittel gegen{\"u}ber Sch{\"a}dlingen erzeugt. Folglich konnte mit Hilfe dieser Methoden ein Syntheseweg f{\"u}r potentielle Pflanzenschutzmittel entwickelt werden. Im zweiten Teil dieser Arbeit wurde ein Zugang zu den sich ebenfalls vom Phenol ableitenden Chromanonen, Chromonen und Cumarinen untersucht. Bei diesen Untersuchungen konnte durch die Entwicklung zweier neuer Tandem-Reaktionen ein nachhaltiger und stufen{\"o}konomischer Syntheseweg zur Darstellung substituierter Benzo(dihydro)pyrone aufgezeigt werden. Durch die erstmalige Kombination der Claisen-Umlagerung mit einer Oxa-Michael-Addition bzw. konjugierten-Addition wurden zwei vollkommen atom{\"o}konomische Reaktionen miteinander verkn{\"u}pft und somit eine {\"u}beraus effiente Synthese von allyl- bzw. prenylsubstituierten Chromanonen und Chromonen erm{\"o}glicht. Ferner konnten durch die Anwendung einer Claisen-Umlagerung-Wittig-Laktonisierungs-Reaktion allyl- bzw. prenylsubstituierte Cumarine erhalten werden. Herausragendes Merkmal dieser Methoden war, dass in nur einem Schritt der jeweilige Naturstoffgrundk{\"o}rper aufgebaut und eine lipophile Seitenkette generiert werden konnte. Die Entwicklung dieser Methoden ist von hohem pharmazeutischem Stellenwert, da auf diesen Wegen Verbindungen synthetisiert werden k{\"o}nnen, die zum einem {\"u}ber das notwendige pharmakologische Grundger{\"u}st verf{\"u}gen und zum anderen {\"u}ber eine Seitenkette, welche die Aufnahmef{\"a}higkeit und damit die Wirksamkeit im Organismus betr{\"a}chtlich erh{\"o}ht. Insgesamt konnten mittels der entwickelten Methoden 15 Chromanon-, Chromon- und Cumarin-Naturstoffe z. T. erstmals synthetisiert werden.},
  language  = {de}
}
@phdthesis{Reiter2014,
  author    = {Reiter, Karsten},
  title     = {Crustal stress variability across spatial scales - examples from Canada, Northern Switzerland and a South African gold mine},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-76762},
  school      = {Universit{\"a}t Potsdam},
  pages     = {VIII, 149, XI},
  year      = {2014},
  abstract  = {The quantitative descriptions of the state of stress in the Earth's crust, and spatial-temporal stress changes are of great importance in terms of scientific questions as well as applied geotechnical issues. Human activities in the underground (boreholes, tunnels, caverns, reservoir management, etc.) have a large impact on the stress state. It is important to assess, whether these activities may lead to (unpredictable) hazards, such as induced seismicity. Equally important is the understanding of the in situ stress state in the Earth's crust, as it allows the determination of safe well paths, already during well planning. The same goes for the optimal configuration of the injection- and production wells, where stimulation for artificial fluid path ways is necessary. The here presented cumulative dissertation consists of four separate manuscripts, which are already published, submitted or will be submitted for peer review within the next weeks. The main focus is on the investigation of the possible usage of geothermal energy in the province Alberta (Canada). A 3-D geomechanical-numerical model was designed to quantify the contemporary 3-D stress tensor in the upper crust. For the calibration of the regional model, 321 stress orientation data and 2714 stress magnitude data were collected, whereby the size and diversity of the database is unique. A calibration scheme was developed, where the model is calibrated versus the in situ stress data stepwise for each data type and gradually optimized using statistically test methods. The optimum displacement on the model boundaries can be determined by bivariate linear regression, based on only three model runs with varying deformation ratio. The best-fit model is able to predict most of the in situ stress data quite well. Thus, the model can provide the full stress tensor along any chosen virtual well paths. This can be used to optimize the orientation of horizontal wells, which e.g. can be used for reservoir stimulation. The model confirms regional deviations from the average stress orientation trend, such as in the region of the Peace River Arch and the Bow Island Arch. In the context of data compilation for the Alberta stress model, the Canadian database of the World Stress Map (WSM) could be expanded by including 514 new data records. This publication of an update of the Canadian stress map after ~20 years with a specific focus on Alberta shows, that the maximum horizontal stress (SHmax) is oriented southwest to northeast over large areas in Northern America. The SHmax orientation in Alberta is very homogeneous, with an average of about 47°. In order to calculate the average SHmax orientation on a regular grid as well as to estimate the wave-length of stress orientation, an existing algorithm has been improved and is applied to the Canadian data. The newly introduced quasi interquartile range on the circle (QIROC) improves the variance estimation of periodic data, as it is less susceptible to its outliers. Another geomechanical-numerical model was built to estimate the 3D stress tensor in the target area "N{\"o}rdlich L{\"a}gern" in Northern Switzerland. This location, with Opalinus clay as a host rock, is a potential repository site for high-level radioactive waste. The performed modelling aims to investigate the sensitivity of the stress tensor on tectonic shortening, topography, faults and variable rock properties within the Mesozoic sedimentary stack, according to the required stability needed for a suitable radioactive waste disposal site. The majority of the tectonic stresses caused by the far-field shortening from the South are admitted by the competent rock units in the footwall and hanging wall of the argillaceous target horizon, the Upper Malm and Upper Muschelkalk. Thus, the differential stress within the host rock remains relatively low. East-west striking faults release stresses driven by tectonic shortening. The purely gravitational influence by the topography is low; higher SHmax magnitudes below topographical depression and lower values below hills are mainly observed near the surface. A complete calibration of the model is not possible, as no stress magnitude data are available for calibration, yet. The collection of this data will begin in 2015; subsequently they will be used to adjust the geomechanical-numerical model again. The third geomechanical-numerical model investigates the stress variation in an ultra-deep gold mine in South Africa. This reservoir model is spatially one order of magnitude smaller than the previous local model from Northern Switzerland. Here, the primary focus is to investigate the hypothesis that the Mw 1.9 earthquake on 27 December 2007 was induced by stress changes due to the mining process. The Coulomb failure stress change (DeltaCFS) was used to analyse the stress change. It confirmed that the seismic event was induced by static stress transfer due to the mining progress. The rock was brought closer to failure on the derived rupture plane by stress changes of up to 1.5-15MPa, in dependence of the DeltaCFS analysis type. A forward modelling of a generic excavation scheme reveals that with decreasing distance to the dyke the DeltaCFS values increase significantly. Hence, even small changes in the mining progress can have a significant impact on the seismic hazard risk, i.e. the change of the occurrence probability to induce a seismic event of economic concern.},
  language  = {en}
}
@phdthesis{Raiser2014,
  author    = {Raiser, Christoph},
  title     = {Kompromisse im Europ{\"a}ischen Parlament : eine kultursoziologische Analyse von Entscheidungsprozessen in einer supranationalen Institution},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  isbn      = {978-3-86956-283-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69560},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxiii, 313},
  year      = {2014},
  abstract  = {Das Europ{\"a}ische Parlament ist zweifelsohne die m{\"a}chtigste parlamentarische Versammlung auf supranationaler Ebene. Das provoziert die Frage, wie Entscheidungen in diesem Parlament gef{\"a}llt werden und wie sie begr{\"u}ndet werden k{\"o}nnen. Darin liegt das Hauptanliegen dieser Arbeit, die zur Beantwortung dieser Frage auf soziologische Ans{\"a}tze der Erkl{\"a}rung sozialen Handelns zur{\"u}ckgreift und damit einen neuen Zugang zur Beobachtung parlamentarischen Handelns schafft. Dabei arbeitet sie heraus, wie wichtig es ist, bei der Analyse politischer Entscheidungsprozesse zu beachten, wie politische Probleme von Akteuren interpretiert und gegen{\"u}ber Verhandlungspartnern dargestellt werden. An den Fallbeispielen der Entscheidungsprozesse zur Dienstleistungsrichtlinie, zur Chemikalien-Verordnung REACH und dem TDIP (CIA)-Ausschuss in der Legislaturperiode 2004-2009, wird der soziale Mechanismus dargestellt, der hinter Einigungen im Europ{\"a}ischen Parlament steckt. Kultur als Interpretation der Welt wird so zum Schl{\"u}ssel des Verst{\"a}ndnisses politischer Entscheidungen auf supranationaler Ebene.},
  language  = {de}
}
@phdthesis{Radeff2014,
  author    = {Radeff, Giuditta},
  title     = {Geohistory of the Central Anatolian Plateau southern margin (southern Turkey)},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71865},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {The Adana Basin of southern Turkey, situated at the SE margin of the Central Anatolian Plateau is ideally located to record Neogene topographic and tectonic changes in the easternmost Mediterranean realm. Using industry seismic reflection data we correlate 34 seismic profiles with corresponding exposed units in the Adana Basin. The time-depth conversion of the interpreted seismic profiles allows us to reconstruct the subsidence curve of the Adana Basin and to outline the occurrence of a major increase in both subsidence and sedimentation rates at 5.45 - 5.33 Ma, leading to the deposition of almost 1500 km3 of conglomerates and marls. Our provenance analysis of the conglomerates reveals that most of the sediment is derived from and north of the SE margin of the Central Anatolian Plateau. A comparison of these results with the composition of recent conglomerates and the present drainage basins indicates major changes between late Messinian and present-day source areas. We suggest that these changes in source areas result of uplift and ensuing erosion of the SE margin of the plateau. This hypothesis is supported by the comparison of the Adana Basin subsidence curve with the subsidence curve of the Mut Basin, a mainly Neogene basin located on top of the Central Anatolian Plateau southern margin, showing that the Adana Basin subsidence event is coeval with an uplift episode of the plateau southern margin. The collection of several fault measurements in the Adana region show different deformation styles for the NW and SE margins of the Adana Basin. The weakly seismic NW portion of the basin is characterized by extensional and transtensional structures cutting Neogene deposits, likely accomodating the differential uplift occurring between the basin and the SE margin of the plateau. We interpret the tectonic evolution of the southern flank of the Central Anatolian Plateau and the coeval subsidence and sedimentation in the Adana Basin to be related to deep lithospheric processes, particularly lithospheric delamination and slab break-off.},
  language  = {en}
}
@phdthesis{Pussak2014,
  author    = {Pussak, Marcin},
  title     = {Seismic characterization of geothermal reservoirs by application of the common-reflection-surface stack method and attribute analysis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-77565},
  school      = {Universit{\"a}t Potsdam},
  pages     = {viii, 140},
  year      = {2014},
  abstract  = {An important contribution of geosciences to the renewable energy production portfolio is the exploration and utilization of geothermal resources. For the development of a geothermal project at great depths a detailed geological and geophysical exploration program is required in the first phase. With the help of active seismic methods high-resolution images of the geothermal reservoir can be delivered. This allows potential transport routes for fluids to be identified as well as regions with high potential of heat extraction to be mapped, which indicates favorable conditions for geothermal exploitation. The presented work investigates the extent to which an improved characterization of geothermal reservoirs can be achieved with the new methods of seismic data processing. The summations of traces (stacking) is a crucial step in the processing of seismic reflection data. The common-reflection-surface (CRS) stacking method can be applied as an alternative for the conventional normal moveout (NMO) or the dip moveout (DMO) stack. The advantages of the CRS stack beside an automatic determination of stacking operator parameters include an adequate imaging of arbitrarily curved geological boundaries, and a significant increase in signal-to-noise (S/N) ratio by stacking far more traces than used in a conventional stack. A major innovation I have shown in this work is that the quality of signal attributes that characterize the seismic images can be significantly improved by this modified type of stacking in particular. Imporoved attribute analysis facilitates the interpretation of seismic images and plays a significant role in the characterization of reservoirs. Variations of lithological and petro-physical properties are reflected by fluctuations of specific signal attributes (eg. frequency or amplitude characteristics). Its further interpretation can provide quality assessment of the geothermal reservoir with respect to the capacity of fluids within a hydrological system that can be extracted and utilized. The proposed methodological approach is demonstrated on the basis on two case studies. In the first example, I analyzed a series of 2D seismic profile sections through the Alberta sedimentary basin on the eastern edge of the Canadian Rocky Mountains. In the second application, a 3D seismic volume is characterized in the surroundings of a geothermal borehole, located in the central part of the Polish basin. Both sites were investigated with the modified and improved stacking attribute analyses. The results provide recommendations for the planning of future geothermal plants in both study areas.},
  language  = {en}
}
@phdthesis{Pixner2014,
  author    = {Pixner, Sofia},
  title     = {Evaluation einer Gesundheitspr{\"a}ventionsmaßnahme f{\"u}r baden-w{\"u}rttembergische Lehrkr{\"a}fte (Lehrergesundheitsprojekt) gem{\"a}ß dem "Lehrer/innen-Coaching nach dem Freiburger Modell" in zwei Darbietungsmodi},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-77998},
  school      = {Universit{\"a}t Potsdam},
  pages     = {192},
  year      = {2014},
  abstract  = {In der Berufsgruppe der Lehrerinnen und Lehrer besteht eine hohe Pr{\"a}valenz psychischer und psychosomatischer Erkrankungen. Aus- und Weiterbildungsangebote zur Vermittlung lehrerspezifischer sozialer Kompetenzen spielen eine wichtige Rolle bei der F{\"o}rderung der Lehrergesundheit. In der vorliegenden Studie wurde das „Lehrer/innen-Coaching nach dem Freiburger Modell" evaluiert, welches die Kompetenz von Lehrkr{\"a}ften st{\"a}rken soll, innerhalb der Schule und insbesondere im Unterricht, schwierige interpersonelle Situationen aktiv und konstruktiv zu gestalten. Damit sollen stressbedingte gesundheitliche Belastungen abgebaut und dem Entstehen gravierender psychischer St{\"o}rungen vorgebeugt werden. In der vorliegenden Arbeit werden zwei modifizierte Versionen dieses Programms erstmalig im Rahmen einer landesweiten Feldstudie untersucht. Die zentralen Evaluationsfragestellungen beziehen sich auf die Effektivit{\"a}t der Intervention als Gesundheitsf{\"o}rderungsmaßnahme (Akzeptanz, Wirksamkeit, Wirksamkeitsvergleich der beiden Interventionsformen im landesweiten Einsatz). Daneben strebt die Studie einen Vergleich mit den Ergebnissen einer Vorg{\"a}ngerstudie sowie die Generierung weiterer Erkenntnisse zum Zusammenhang zwischen Aspekten der sozialen Kompetenz von Lehrkr{\"a}ften und ihrer psychischen Gesundheit an. An der Maßnahme konnten alle baden-w{\"u}rttembergischen Lehrerinnen und Lehrer mit einer Berufserfahrung von mindestens 10 Jahren teilnehmen. F{\"u}r die Untersuchung der Wirksamkeit der Maßnahme und des Wirksamkeitsvergleichs der beiden unterschiedlichen Formen liegt ein quasiexperimentelles Design mit insgesamt zwei Messzeitpunkten vor. In die Auswertung zur Wirksamkeit der Intervention konnten die Daten von den 314 Teilnehmern einbezogen werden. Die Messinstrumente, die in der vorliegenden Studie zur Anwendung kamen, waren der General Health Questionnaire (GHQ-12), das Maslach Burnout Inventory (MBI-D) und die ins Deutsche {\"u}bersetzte Jefferson Scale of Empathy (JSE) in der an Lehrer adaptierten Form. Die Evaluationsergebnisse zeigen, dass die Teilnahme am „Lehrer/innen-Coaching nach dem Freiburger Modell" mit einer signifikanten Verbesserung der gesundheitsbezogenen abh{\"a}ngigen Variablen einhergeht. Besonders hervorzuheben ist die ausgepr{\"a}gte Verbesserung der mittels GHQ-12 erfassten psychischen Gesundheit. Das Ergebnis des Pr{\"a}-Post-Vergleichs der Gesundheitswerte beider Interventionsgruppen best{\"a}tigte sich auch im Vergleich zu einer Null-Interventionsgruppe: Entsprechend der Hypothese gab es bei den Teilnehmern eine signifikant st{\"a}rkere Verbesserung der psychischen Gesundheit als bei den Nicht-Teilnehmern (Null-Interventionsgruppe). Die beiden Interventionsmodi „Kompaktform" und „Kurzform" erwiesen sich im Hinblick auf die Verbesserung der Lehrergesundheit als gleichermaßen wirksam. Zudem zeigen die Ergebnisse der Teilnehmerbefragung, dass die Maßnahme Anklang bei der Zielgruppe fand. Die Akzeptanz durch die Zielgruppe ist f{\"u}r die Wirksamkeit einer auf Freiwilligkeit basierenden verhaltenspr{\"a}ventiven Maßnahme naturgem{\"a}ß eine essenzielle Voraussetzung. Bei der psychischen Gesundheit der Lehrer bestehen - wie aus weiteren Befunden der Studie ersichtlich - bedeutsame Zusammenh{\"a}nge zu einer intakten zwischenmenschlichen Beziehung mit den Sch{\"u}lern, einer gelungenen, durch gegenseitige Unterst{\"u}tzung gekennzeichneten Interaktion im Kollegium und einem entsprechend unterst{\"u}tzenden F{\"u}hrungsverhalten der Schulleitung. Dies macht deutlich, welches besondere Gewicht einer gelingenden Beziehungsgestaltung an Schulen und im Unterricht beizumessen ist. Bez{\"u}glich der Vorgehensweise in der vorliegenden Untersuchung werden einige methodische Limitationen hinsichtlich des Designs diskutiert. Erg{\"a}nzend wird im Ausblick der Evaluationsstudie darauf hingewiesen, wie sich durch die Verkn{\"u}pfung des vorliegenden Programms mit weiteren, auf den Ebenen Verhalten, Verh{\"a}ltnisse und F{\"u}hrung ansetzenden gesundheitspr{\"a}ventiven Maßnahmen, zuk{\"u}nftig die St{\"a}rkung der psychischen Gesundheit von Lehrkr{\"a}ften weiter ausbauen ließe.},
  language  = {de}
}
@phdthesis{Orgis2014,
  author    = {Orgis, Thomas},
  title     = {Unstetige Galerkin-Diskretisierung niedriger Ordnung in einem atmosph{\"a}rischen Multiskalenmodell},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70687},
  school      = {Universit{\"a}t Potsdam},
  year      = {2014},
  abstract  = {Die Dynamik der Atmosph{\"a}re der Erde umfasst einen Bereich von mikrophysikalischer Turbulenz {\"u}ber konvektive Prozesse und Wolkenbildung bis zu planetaren Wellenmustern. F{\"u}r Wettervorhersage und zur Betrachtung des Klimas {\"u}ber Jahrzehnte und Jahrhunderte ist diese Gegenstand der Modellierung mit numerischen Verfahren. Mit voranschreitender Entwicklung der Rechentechnik sind Neuentwicklungen der dynamischen Kerne von Klimamodellen, die mit der feiner werdenden Aufl{\"o}sung auch entsprechende Prozesse aufl{\"o}sen k{\"o}nnen, notwendig. Der dynamische Kern eines Modells besteht in der Umsetzung (Diskretisierung) der grundlegenden dynamischen Gleichungen f{\"u}r die Entwicklung von Masse, Energie und Impuls, so dass sie mit Computern numerisch gel{\"o}st werden k{\"o}nnen. Die vorliegende Arbeit untersucht die Eignung eines unstetigen Galerkin-Verfahrens niedriger Ordnung f{\"u}r atmosph{\"a}rische Anwendungen. Diese Eignung f{\"u}r Gleichungen mit Wirkungen von externen Kr{\"a}ften wie Erdanziehungskraft und Corioliskraft ist aus der Theorie nicht selbstverst{\"a}ndlich. Es werden n{\"o}tige Anpassungen beschrieben, die das Verfahren stabilisieren, ohne sogenannte „slope limiter" einzusetzen. F{\"u}r das unmodifizierte Verfahren wird belegt, dass es nicht geeignet ist, atmosph{\"a}rische Gleichgewichte stabil darzustellen. Das entwickelte stabilisierte Modell reproduziert eine Reihe von Standard-Testf{\"a}llen der atmosph{\"a}rischen Dynamik mit Euler- und Flachwassergleichungen in einem weiten Bereich von r{\"a}umlichen und zeitlichen Skalen. Die L{\"o}sung der thermischen Windgleichung entlang der mit den Isobaren identischen charakteristischen Kurven liefert atmosph{\"a}rische Gleichgewichtszust{\"a}nde mit durch vorgegebenem Grundstrom einstellbarer Neigung zu(barotropen und baroklinen)Instabilit{\"a}ten, die f{\"u}r die Entwicklung von Zyklonen wesentlich sind. Im Gegensatz zu fr{\"u}heren Arbeiten sind diese Zust{\"a}nde direkt im z-System(H{\"o}he in Metern)definiert und m{\"u}ssen nicht aus Druckkoordinaten {\"u}bertragen werden.Mit diesen Zust{\"a}nden, sowohl als Referenzzustand, von dem lediglich die Abweichungen numerisch betrachtet werden, und insbesondere auch als Startzustand, der einer kleinen St{\"o}rung unterliegt, werden verschiedene Studien der Simulation von barotroper und barokliner Instabilit{\"a}t durchgef{\"u}hrt. Hervorzuheben ist dabei die durch die Formulierung von Grundstr{\"o}men mit einstellbarer Baroklinit{\"a}t erm{\"o}glichte simulationsgest{\"u}tzte Studie des Grades der baroklinen Instabilit{\"a}t verschiedener Wellenl{\"a}ngen in Abh{\"a}ngigkeit von statischer Stabilit{\"a}t und vertikalem Windgradient als Entsprechung zu Stabilit{\"a}tskarten aus theoretischen Betrachtungen in der Literatur.},
  language  = {de}
}
@phdthesis{Nguyen2014,
  author    = {Nguyen, Van Manh},
  title     = {Large-scale floodplain sediment dynamics in the Mekong Delta : present state and future prospects},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72512},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ix, 95},
  year      = {2014},
  abstract  = {The Mekong Delta (MD) sustains the livelihood and food security of millions of people in Vietnam and Cambodia. It is known as the "rice bowl" of South East Asia and has one of the world's most productive fisheries. Sediment dynamics play a major role for the high productivity of agriculture and fishery in the delta. However, the MD is threatened by climate change, sea level rise and unsustainable development activities in the Mekong Basin. But despite its importance and the expected threats, the understanding of the present and future sediment dynamics in the MD is very limited. This is a consequence of its large extent, the intricate system of rivers, channels and floodplains and the scarcity of observations. Thus this thesis aimed at (1) the quantification of suspended sediment dynamics and associated sediment-nutrient deposition in floodplains of the MD, and (2) assessed the impacts of likely future boundary changes on the sediment dynamics in the MD. The applied methodology combines field experiments and numerical simulation to quantify and predict the sediment dynamics in the entire delta in a spatially explicit manner. The experimental part consists of a comprehensive procedure to monitor quantity and spatial variability of sediment and associated nutrient deposition for large and complex river floodplains, including an uncertainty analysis. The measurement campaign applied 450 sediment mat traps in 19 floodplains over the MD for a complete flood season. The data also supports quantification of nutrient deposition in floodplains based on laboratory analysis of nutrient fractions of trapped sedimentation.The main findings are that the distribution of grain size and nutrient fractions of suspended sediment are homogeneous over the Vietnamese floodplains. But the sediment deposition within and between ring dike floodplains shows very high spatial variability due to a high level of human inference. The experimental findings provide the essential data for setting up and calibration of a large-scale sediment transport model for the MD. For the simulation studies a large scale hydrodynamic model was developed in order to quantify large-scale floodplain sediment dynamics. The complex river-channel-floodplain system of the MD is described by a quasi-2D model linking a hydrodynamic and a cohesive sediment transport model. The floodplains are described as quasi-2D presentations linked to rivers and channels modeled in 1D by using control structures. The model setup, based on the experimental findings, ignored erosion and re-suspension processes due to a very high degree of human interference during the flood season. A two-stage calibration with six objective functions was developed in order to calibrate both the hydrodynamic and sediment transport modules. The objective functions include hydraulic and sediment transport parameters in main rivers, channels and floodplains. The model results show, for the first time, the tempo-spatial distribution of sediment and associated nutrient deposition rates in the whole MD. The patterns of sediment transport and deposition are quantified for different sub-systems. The main factors influencing spatial sediment dynamics are the network of rivers, channels and dike-rings, sluice gate operations, magnitude of the floods and tidal influences. The superposition of these factors leads to high spatial variability of the sediment transport and deposition, in particular in the Vietnamese floodplains. Depending on the flood magnitude, annual sediment loads reaching the coast vary from 48\% to 60\% of the sediment load at Kratie, the upper boundary of the MD. Deposited sediment varies from 19\% to 23\% of the annual load at Kratie in Cambodian floodplains, and from 1\% to 6\% in the compartmented and diked floodplains in Vietnam. Annual deposited nutrients (N, P, K), which are associated to the sediment deposition, provide on average more than 50\% of mineral fertilizers typically applied for rice crops in non-flooded ring dike compartments in Vietnam. This large-scale quantification provides a basis for estimating the benefits of the annual Mekong floods for agriculture and fishery, for assessing the impacts of future changes on the delta system, and further studies on coastal deposition/erosion. For the estimation of future prospects a sensitivity-based approach is applied to assess the response of floodplain hydraulics and sediment dynamics to the changes in the delta boundaries including hydropower development, climate change in the Mekong River Basin and effective sea level rise. The developed sediment model is used to simulate the mean sediment transport and sediment deposition in the whole delta system for the baseline (2000-2010) and future (2050-2060) periods. For each driver we derive a plausible range of future changes and discretize it into five levels, resulting in altogether 216 possible factor combinations. Our results thus cover all plausible future pathways of sediment dynamics in the delta based on current knowledge. The uncertainty of the range of the resulting impacts can be decreased in case more information on these drivers becomes available. Our results indicate that the hydropower development dominates the changes in sediment dynamics of the Mekong Delta, while sea level rise has the smallest effect. The floodplains of Vietnamese Mekong Delta are much more sensitive to the changes compared to the other subsystems of the delta. In terms of median changes of the three combined drivers, the inundation extent is predicted to increase slightly, but the overall floodplain sedimentation would be reduced by approximately 40\%, while the sediment load to the Sea would diminish to half of the current rates. These findings provide new and valuable information on the possible impacts of future development on the delta, and indicate the most vulnerable areas. Thus, the presented results are a significant contribution to the ongoing international discussion on the hydropower development in the Mekong basin and its impact on the Mekong delta.},
  language  = {en}
}
@phdthesis{NetchaevBakinski2014,
  author    = {Netchaev-Bakinski, Alexandre},
  title     = {Les voies/voix radicales en Angleterre, 1789-1848},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-75472},
  school      = {Universit{\"a}t Potsdam},
  pages     = {355},
  year      = {2014},
  abstract  = {What is a radical? Somebody who goes against mainstream opinions? An agitator who suggests transforming society at the risk of endangering its harmony? In the political context of the British Isles at the end of the eighteenth century, the word radical had a negative connotation. It referred to the Levellers and the English Civil War, it brought back a period of history which was felt as a traumatic experience. Its stigmas were still vivid in the mind of the political leaders of these times. The reign of Cromwell was certainly the main reason for the general aversion of any form of virulent contestation of the power, especially when it contained political claims. In the English political context, radicalism can be understood as the different campaigns for parliamentary reforms establishing universal suffrage. However, it became evident that not all those who were supporting such a reform originated from the same social class or shared the same ideals. As a matter of fact, the reformist associations and their leaders often disagreed with each other. Edward Royle and Hames Walvin claimed that radicalism could not be analyzed historically as a concept, because it was not a homogeneous movement, nor it had common leaders and a clear ideology. For them, radicalism was merely a loose concept, « a state of mind rather than a plan of action. » At the beginning of the nineteenth-century, the newspaper The Northern Star used the word radical in a positive way to designate a person or a group of people whose ideas were conform to those of the newspaper. However, an opponent of parliamentary reform will use the same word in a negative way, in this case the word radical will convey a notion of menace. From the very beginning, the term radical covered a large spectrum of ideas and conceptions. In fact, the plurality of what the word conveys is the main characteristic of what a radical is. As a consequence, because the radicals tended to differentiate themselves with their plurality and their differences rather than with common features, it seems impossible to define what radicalism (whose suffix in -ism implies that it designate a doctrine, an ideology) is. Nevertheless, today it is accepted by all historians. From the mid-twentieth century, we could say that it was taken from granted to consider radicalism as a movement that fitted with the democratic precepts (universal suffrage, freedom of speech) of our modern world. Let us first look at radicalism as a convenient way to designate the different popular movements appealing to universal suffrage during the time period 1792-1848. We could easily observe through the successions of men and associations, a long lasting radical state of mind: Cartwright, Horne Tooke, Thomas Hardy, Francis Burdett, William Cobbett, Henry Hunt, William Lovett, Bronterre O'Brien, Feargus O'Connor, The London Society for Constitutional information (SCI), The London Corresponding Society (LCS), The Hampden Clubs, The Chartists, etc. These organizations and people acknowledged having many things in common and being inspired by one another in carrying out their activities. These influences can be seen in the language and the political ideology that British historians name as "Constitutionalist", but also, in the political organization of extra-parliamentary societies. Most of the radicals were eager to redress injustices and, in practice, they were inspired by a plan of actions drawn on from the pamphlets of the True Whigs of the eighteenth-century. We contest the argument that the radicals lacked coherence and imagination or that they did not know how to put into practice their ambitions. In fact, their innovative forms of protest left a mark on history and found many successors in the twentieth century. Radicals' prevarications were the result of prohibitive legislation that regulated the life of associations and the refusal of the authorities to cooperate with them. As mentioned above, the term radical was greatly used and the contemporaries of the period starting from the French Revolution to Chartism never had to quarrel about the notions the word radical covered. However, this does not imply that all radicals were the same or that they belong to the same entity. Equally to Horne Tooke, the Reverend and ultra-Tory Stephens was considered as a radical, it went also with the shoemaker Thomas Hardy and the extravagant aristocrat Francis Burdett. Whether one belonged to the Aristocracy, the middle-class, the lower class or the Church, nothing could prevent him from being a radical. Surely, anybody could be a radical in its own way. Radicalism was wide enough to embrace everybody, from revolutionary reformers to paternalistic Tories. We were interested to clarify the meaning of the term radical because its inclusive nature was overlooked by historians. That's why the term radical figures in the original title of our dissertation Les voix/voies radicales (radical voices/ways to radicalism). In the French title, both words voix/voies are homonymous; the first one voix (voice) correspond to people, the second one voies (ways) refers to ideas. By this, we wanted to show that the word radical belongs to the sphere of ideas and common experience but also to the nature of human beings. Methodoloy The thesis stresses less on the question of class and its formation than on the circumstances that brought people to change their destiny and those of their fellows or to modernize the whole society. We challenged the work of E.P. Thompson, who in his famous book, The Making of the English Working Class, defined the radical movements in accordance with an idea of class. How a simple shoe-maker, Thomas Hardy, could become the center of attention during a trial where he was accused of being the mastermind of a modern revolution? What brought William Cobbett, an ultra-Tory, self-taught intellectual, to gradually espouse the cause of universal suffrage at a period where it was unpopular to do so? Why a whole population gathered to hear Henry Hunt, a gentleman farmer whose background did not destine him for becoming the champion of the people? It seemed that the easiest way to answer to these questions and to understand the nature of the popular movements consisted in studying the life of their leaders. We aimed at reconstructing the universe which surrounded the principal actors of the reform movements as if we were a privileged witness of theses times. This idea to associate the biographies of historical characters for a period of more than fifty years arouse when we realized that key events of the reform movements were echoing each other, such the trial of Thomas Hardy in 1794 and the massacre of Peterloo of 1819. The more we learned about the major events of radicalism and the life of their leaders, the more we were intrigued. Finally, one could ask himself if being a radical was not after all a question of character rather than one of class. The different popular movements in favour of a parliamentary reform were in fact far more inclusive and diversified from what historians traditionally let us to believe. For instance, once he manage to gather a sufficient number of members of the popular classes, Thomas Hardy projected to give the control of his association to an intellectual elite led by Horne Tooke. Moreover, supporters of the radical reforms followed leaders whose background was completely different as theirs. For example, O'Connor claimed royal descent from the ancient kings of Ireland. William Cobbett, owner of a popular newspaper was proud of his origins as a farmer. William Lovett, close to the liberals and a few members of parliament came from a very poor family of fishermen. We have thus put together the life of these five men, Thomas hardy, William Cobbett, Henry Hunt, William Lovett and Feargus O'Connor in order to compose a sort of a saga of the radicals. This association gives us a better idea of the characteristics of the different movements in which they participated, but also, throw light on the circumstances of their formation and their failures, on the particular atmosphere which prevailed at these times, on the men who influenced these epochs, and finally on the marks they had left. These men were at the heart of a whole network and in contact with other actors of peripheral movements. They gathered around themselves close and loyal fellows with whom they shared many struggles but also quarreled and had strong words. The original part of our approach is reflected in the choice to not consider studying the fluctuations of the radical movements in a linear fashion where the story follows a strict chronology. We decided to split up the main issue of the thesis through different topics. To do so, we simply have described the life of the people who inspired these movements. Each historical figure covers a chapter, and the general story follows a chronological progression. Sometimes we had to go back through time or discuss the same events in different chapters when the main protagonists lived in the same period of time. Radical movements were influenced by people of different backgrounds. What united them above all was their wish to obtain a normalization of the political world, to redress injustices and obtain parliamentary reform. We paid particular attention to the moments where the life of these men corresponded to an intense activity of the radical movement or to a transition of its ideas and organization. We were not so much interested in their feelings about secondary topics nor did we about their affective relations. Furthermore, we had little interest in their opinions on things which were not connected to our topic unless it helped us to have a better understanding of their personality. We have purposely reduced the description of our protagonists to their radical sphere. Of course we talked about their background and their intellectual development; people are prone to experience reversals of opinions, the case of Cobbett is the most striking one. The life of these personalities coincided with particular moments of the radical movement, such as the first popular political associations, the first open-air mass meetings, the first popular newspapers, etc. We wanted to emphasize the personalities of those who addressed speeches and who were present in the radical associations. One could argue that the inconvenience of focusing on a particular person presents a high risk of overlooking events and people who were not part of his world. However, it was essential to differ from an analysis or a chronicle which had prevailed in the studies of the radical movements, as we aimed at offering a point of view that completed the precedents works written on that topic. In order to do so, we have deliberately put the humane character of the radical movement at the center of our work and used the techniques of biography as a narrative thread. Conclusion The life of each historical figure that we have portrayed corresponded to a particular epoch of the radical movement. Comparing the speeches of the radical leaders over a long period of time, we noticed that the radical ideology evolved. The principles of the Rights of Men faded away and gave place to more concrete reasoning, such as the right to benefit from one's own labour. This transition is characterized by the Chartist period of Feargus O'Connor. This does not mean that collective memory and radical tradition ceased to play an important part. The popular classes were always appealed to Constitutional rhetoric and popular myths. Indeed, thanks to them they identified themselves and justified their claims to universal suffrage. We focused on the life of a few influent leaders of radicalism in order to understand its evolution and its nature. The description of their lives constituted our narrative thread and it enabled us to maintain consistency in our thesis. If the chapters are independent the one from the other, events and speeches are in correspondences. Sometimes we could believe that we were witnessing a repetition of facts and events as if history was repeating itself endlessly. However, like technical progress, the spirit of time, Zeitgeist, experiences changes and mutations. These features are fundamental elements to comprehend historical phenomena; the latter cannot be simplified to philosophical, sociological, or historical concept. History is a science which has this particularity that the physical reality of phenomena has a human dimension. As a consequence, it is essential not to lose touch with the human aspect of history when one pursues studies and intellectual activities on a historical phenomenon. We decided to take a route opposite to the one taken by many historians. We have first identified influential people from different epochs before entering into concepts analysis. Thanks to this compilation of radical leaders, a new and fresh look to the understanding of radicalism was possible. Of course, we were not the first one to have studied them, but we ordered them following a chronology, like Plutarch enjoyed juxtaposing Greeks and Romans historical figures. Thanks to this technique we wanted to highlight the features of the radical leaders' speeches, personalities and epochs, but also their differences. At last, we tried to draw the outlines and the heart of different radical movements in order to follow the ways that led to radicalism. We do not pretend to have offered an original and exclusive definition of radicalism, we mainly wanted to understand the nature of what defines somebody as a radical and explain the reasons why thousands of people decided to believe in this man. Moreover, we wanted to distance ourselves from the ideological debate of the Cold War which permeated also the interpretation of past events. Too often, the history of radicalism was either narrated with a form of revolutionary nostalgia or in order to praise the merits of liberalism. If the great mass meetings ends in the mid-nineteenth-century with the fall of Chartism, this practice spread out in the whole world in the twentieth-century. Incidentally, the Arab Spring of the beginning of the twenty-first-century demonstrated that a popular platform was the best way for the people to claim their rights and destabilize a political system which they found too authoritative. Through protest the people express an essential quality of revolt, which is an expression of emancipation from fear. From then on, a despotic regime loses this psychological terror which helped it to maintain itself into power. The balance of power between the government and its people would also take a new turn. The radicals won this psychological victory more than 150 years ago and yet universal suffrage was obtained only a century later. From the acceptance of the principles of liberties to their cultural practice, a long route has to be taken to change people's mind. It is a wearisome struggle for the most vulnerable people. In the light of western history, fundamental liberties must be constantly defended. Paradoxically, revolt is an essential and constitutive element of the maintenance of democracy.},
  language  = {fr}
}
@phdthesis{Negri2014,
  author    = {Negri, Michael},
  title     = {How coaches influence referee decisions},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-72247},
  school      = {Universit{\"a}t Potsdam},
  pages     = {132},
  year      = {2014},
  abstract  = {The work elaborates on the question if coaches in non-professional soccer can influence referee decisions. Modeled from a principal-agent perspective, the managing referee boards can be seen as the principal. They aim at facilitating a fair competition which is in accordance with the existing rules and regulations. In doing so, the referees are assigned as impartial agents on the pitch. The coaches take over a non-legitimate principal-like role trying to influence the referees even though they do not have the formal right to do so. Separate questionnaires were set up for referees and coaches. The coach questionnaire aimed at identifying the extent and the forms of influencing attempts by coaches. The referee questionnaire tried to elaborate on the questions if referees take notice of possible influencing attempts and how they react accordingly. The results were put into relation with official match data in order to identify significant influences on personal sanctions (yellow cards, second yellow cards, red cards) and the match result. It is found that there is a slight effect on the referee's decisions. However, this effect is rather disadvantageous for the influencing coach and there is no evidence for an impact on the match result itself.},
  language  = {en}
}
@phdthesis{Munack2014,
  author    = {Munack, Henry},
  title     = {From phantom blocks to denudational noise},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-72629},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvii, 172},
  year      = {2014},
  abstract  = {Knowing the rates and mechanisms of geomorphic process that shape the Earth's surface is crucial to understand landscape evolution. Modern methods for estimating denudation rates enable us to quantitatively express and compare processes of landscape downwearing that can be traced through time and space—from the seemingly intact, though intensely shattered, phantom blocks of the catastrophically fragmented basal facies of giant rockslides up to denudational noise in orogen-wide data sets averaging over several millennia. This great variety of spatiotemporal scales of denudation rates is both boon and bane of geomorphic process rates. Indeed, processes of landscape downwearing can be traced far back in time, helping us to understand the Earth's evolution. Yet, this benefit may turn into a drawback due to scaling issues if these rates are to be compared across different observation timescales. This thesis investigates the mechanisms, patterns and rates of landscape downwearing across the Himalaya-Tibet orogen. Accounting for the spatiotemporal variability of denudation processes, this thesis addresses landscape downwearing on three distinctly different spatial scales, starting off at the local scale of individual hillslopes where considerable amounts of debris are generated from rock instantaneously: Rocksliding in active mountains is a major impetus of landscape downwearing. Study I provides a systematic overview of the internal sedimentology of giant rockslide deposits and thus meets the challenge of distinguishing them from macroscopically and microscopically similar glacial deposits, tectonic fault-zone breccias, and impact breccias. This distinction is important to avoid erroneous or misleading deduction of paleoclimatic or tectonic implications. -> Grain size analysis shows that rockslide-derived micro-breccia closely resemble those from meteorite impact or tectonic faults. -> Frictionite may occur more frequently that previously assumed. -> M{\"o}ssbauer-spectroscopy derived results indicate basal rock melting in the absence of water, involving short-term temperatures of >1500°C. Zooming out, Study II tracks the fate of these sediments, using the example of the upper Indus River, NW India. There we use river sand samples from the Indus and its tributaries to estimate basin-averaged denudation rates along a ~320-km reach across the Tibetan Plateau margin, to answer the question whether incision into the western Tibetan Plateau margin is currently active or not. -> We find an about one-order-of-magnitude upstream decay—from 110 to 10 mm kyr^-1—of cosmogenic Be-10-derived basin-wide denudation rates across the morphological knickpoint that marks the transition from the Transhimalayan ranges to the Tibetan Plateau. This trend is corroborated by independent bulk petrographic and heavy mineral analysis of the same samples. -> From the observation that tributary-derived basin-wide denudation rates do not increase markedly until ~150-200 km downstream of the topographic plateau margin we conclude that incision into the Tibetan Plateau is inactive. -> Comparing our postglacial Be-10-derived denudation rates to long-term (>10^6 yr) estimates from low-temperature thermochronometry, ranging from 100 to 750 mm kyr^-1, points to an order- of-magnitude decay of rates of landscape downwearing towards present. We infer that denudation rates must have been higher in the Quaternary, probably promoted by the interplay of glacial and interglacial stages. Our investigation of regional denudation patterns in the upper Indus finally is an integral part of Study III that synthesizes denudation of the Himalaya-Tibet orogen. In order to identify general and time-invariant predictors for Be-10-derived denudation rates we analyze tectonic, climatic and topographic metrics from an inventory of 297 drainage basins from various parts of the orogen. Aiming to get insight to the full response distributions of denudation rate to tectonic, climatic and topographic candidate predictors, we apply quantile regression instead of ordinary least squares regression, which has been standard analysis tool in previous studies that looked for denudation rate predictors. -> We use principal component analysis to reduce our set of 26 candidate predictors, ending up with just three out of these: Aridity Index, topographic steepness index, and precipitation of the coldest quarter of the year. -> Topographic steepness index proves to perform best during additive quantile regression. Our consequent prediction of denudation rates on the basin scale involves prediction errors that remain between 5 and 10 mm kyr^-1. -> We conclude that while topographic metrics such as river-channel steepness and slope gradient—being representative on timescales that our cosmogenic Be-10-derived denudation rates integrate over—generally appear to be more suited as predictors than climatic and tectonic metrics based on decadal records.},
  language  = {en}
}