Rivers play an important role in the global water cycle, support biodiversity and ecological integrity. However, river flow and thermal regimes are heavily altered in dammed rivers. These impacts are being exacerbated and become more apparent in rivers fragmented by multiple dams. Recent studies mainly focused on evaluating the cumulative impact of cascade reservoirs on flow or thermal regimes, but the role of upstream reservoirs in shaping the hydrology and hydrodynamics of downstream reservoirs remains poorly understood. To improve the understanding of the hydrodynamics in cascade reservoirs, long-term observational data are used in combination with numerical modeling to investigate the changes in flow and thermal regime in three cascade reservoirs at the upper reach of the Yangtze River. The three studied reservoirs are Xiluodu (XLD), Xiangjiaba (XJB) and Three Gorges Reservoir (TGR). In addition, the effects of single reservoir operation (at seasonal/daily time scale) on hydrodynamics are examined in a large tributary of TGR. The results show that the inflow of TGR has been substantially altered by the two upstream reservoirs with a higher discharge in spring and winter and a reduced peak flow in summer. XJB had no obvious contribution to the variations in inflow of TGR. The seasonal water temperature of TGR was also widely affected by the upstream two reservoirs, i.e., an increase in winter and decrease in spring, associated with a delay in water temperature rise and fall. These effects will probably be intensified in the coming years due to the construction of new reservoirs. The study also underlines the importance of reservoir operation in shaping the hydrodynamics of TGR. The seasonal dynamics of density currents in a tributary bay of TGR are closely related to seasonal reservoir operations. In addition, high-frequency water level fluctuations and flow velocity variations were observed in response to periodic tributary bay oscillations, which are driven by the diurnal discharge variations caused by the operation of TGR. As another consequence of operation of cascade reservoirs, the changes in TGR inflow weakened spring thermal stratification and caused warming in spring, autumn and winter. In response to this change, the intrusions from TGR occurred more frequently as overflow and earlier in spring, which caused a sharp reduction in biomass and frequency of phytoplankton blooms in tributary bays of TGR. This study suggests that high-frequency bay oscillations can potentially be used as an efficient management strategy for controlling algal blooms, which can be included in future multi-objective ecological conservation strategies.

Real-time operating systems for mixed-criticality systems must support different types of software, such as real-time applications and general purpose applications, and, at the same time, must provide strong spatial and temporal isolation between independent software components. Therefore, state-of-the-art real-time operating systems focus mainly on predictability and bounded worst-case behavior. However, general purpose operating systems such as Linux often feature more efficient---but less deterministic---mechanisms that significantly improve the average execution time. This thesis addresses the combination of the two contradicting requirements and shows thread synchronization mechanisms with efficient average-case behavior, but without sacrificing predictability and worst-case behavior. This thesis explores and evaluates the design space of fast paths in the implementation of typical blocking synchronization mechanisms, such as mutexes, condition variables, counting semaphores, barriers, or message queues. The key technique here is to avoid unnecessary system calls, as system calls have high costs compared to other processor operations available in user space, such as low-level atomic synchronization primitives. In particular, the thesis explores futexes, the state-of-the-art design for blocking synchronization mechanisms in Linux that handles the uncontended case of thread synchronization by using atomic operations in user space and calls into the kernel only to suspend and wake up threads. The thesis also proposes non-preemptive busy-waiting monitors that use an efficient priority ceiling mechanism to prevent the lock holder preemption problem without using system calls, and according low-level kernel primitives to construct efficient wait and notify operations. The evaluation shows that the presented approaches improve the average performance comparable to state-of-the-art approaches in Linux. At the same time, a worst-case timing analysis shows that the approaches only need constant or bounded temporal overheads at the operating system kernel level. Exploiting these fast paths is a worthwhile approach when designing systems that not only have to fulfill real-time requirements, but also best-effort workloads.

Internationale Bildungsstudien (TIMSS und PISA) offenbarten, dass es deutschen Schülern nur begrenzt gelingt, ihr erworbenes Wissen im Physikunterricht zur Problemlösung in neuen Kontexten zu nutzen. Als Grund nennen die Studien die gering ausgeprägte Kompetenz-erwartung in Bezug zum Fach Physik. Die Folge ist eine geringe Motivation der Lernenden, physikalische Aufgaben zu lösen. Studien zeigen aber auch, dass die Motivation beim Lernen durch den Einsatz digitaler Lernmedien gesteigert werden konnte. Aus diesem Grund wird in dieser Arbeit untersucht, ob das Vertrauen in die eigenen Fähigkeiten durch das Lernen in einer integrierten Lernumgebung gefördert werden kann. Im Rahmen eines Design-Based-Research-Forschungsansatzes (DBR) wurde eine integrierte Lernumgebung „Wärmelehre“ mit digitalen Lernmedien für den Physikunterricht gestaltet, die dann in zwei Schulformen (IGS und Gymnasium) innerhalb einer quasi-experimentellen Feldstudie erprobt wurde. Im 1. Zyklus des DBR wurden die Wirkungen des selbstständigen Lernens mit digitalen/analogen Medien in Einzelarbeit untersucht. Die Ergebnisse der Wissenstests zeigen einen höheren Lernerfolg bei den Lernenden der Experimentalgruppen, der sich aber nicht signifikant von den Lernenden der Kontrollgruppen (analoge Medien) unterscheidet. Die Lernenden konnten sich in der integrierten Lernumgebung mit Unterstützung beider Medienformate selbstständig Fachwissen aneignen und problembasierte Textaufgaben lösen. Die Ergebnisse der Befragungen der Lernenden zeigen, dass sich die Lerngruppen signifikant in ihrem erlebten Grad der Selbststeuerung unterscheiden. Die Lernenden beider Experimentalgruppen bewerten ihren Handlungsspielraum besser als die Lernenden der beiden Kontrollgruppen. Ebenfalls konnte festgestellt werden, dass sich die individuellen Lernvoraussetzungen, der Lernstiltyp, das Kompetenzerleben und die Aspekte der Medien-gestaltung wechselseitig beeinflussen und auf den Lernerfolg wirken. Die Ergebnisse der Lernstilanalyse zeigen, dass sich selbst kleine Lerngruppen heterogen zusammensetzen. Demnach scheint es für einen guten Lernerfolg notwendig zu sein, dass die Lehrenden, die Lernumgebung an die individuellen Lernpräferenzen der Lernenden der Lerngruppe anpassen. Aus den Ergebnissen lässt sich als Konsequenz für den Physikunterricht ableiten, dass Selbstlernphasen mit digitalen Lernmedien regelmäßig in den Unterricht integriert werden sollten, um die Problemlöse- und die Selbststeuerungskompetenz zu fördern. Es ist von Vorteil, wenn die Lehrenden für die Gestaltung einer Lernumgebung, das Vorwissen, die individuellen Lernvoraussetzungen und die Zusammensetzung der Lerngruppe (Lernstiltyp) als Qualitätsdimensionen erfassen. Im Re-Design werden Vorschläge unterbreitet, wie die integrierte Lernumgebung lernstilgerecht weiterentwickelt werden kann. Im 2. Zyklus soll dann erforscht werden, ob sich Unterschiede im Lernerfolg und in den untersuchten Aspekten zeigen, wenn die Lernenden in Einzelarbeit, in Partnerarbeit oder in ihrer Lernstilgruppe selbstgesteuert lernen, um die Lernumgebung zyklisch weiterzuentwickeln.

Obwohl Kinder beim Bauen mit Bauklötzen bereits früh Erfahrungen mit Aspekten der Stabilität von Bauwerken, wie z. B. Kräfteverteilung, Standfestigkeit sowie Gleich- und Gegengewicht, sammeln und es verschiedene Studien gibt, die den fächerübergreifenden Lerngehalt von Bauklötzen hervorheben, ist das Verständnis bezüglich der Stabilität von Bauklotzanordnungen bisher kaum erforscht. Daher wurde untersucht, welche Vorstellungen sechs- bis siebenjährige Kinder zur Stabilität von Bauklotzanordnungen zeigen und welche Unterstützungsmaßnahmen eine Vorstellungsveränderung anregen. In Studie 1 und 2 zeigt sich, dass Kinder in der Schuleingangsphase erste Vorstellungen zur Stabilität von Bauklotzanordnungen haben. Über verschiedene Analysen wurden schwierigkeitsbestimmende Merkmale bzw. lösungsrelevante Dimensionen identifiziert. Kinder mit ca. fünf Jahren orientieren sich eher an der geometrischen Mitte und beziehen somit die Abstandsdimension ein, bei Neunjährigen berücksichtigen hingegen knapp über die Hälfte bereits den Massenmittelpunkt. Folglich reicht die „Bauerfahrung“ von Kindern bis zum neunten Lebensjahr nicht aus, um die Fähigkeit, Bauklotzanordnungen bezüglich ihrer Stabilität zu beurteilen, vollständig zu entwickeln. Deshalb wurde in Studie 3 untersucht, inwieweit sich eine Vorstellungsveränderung zur Stabilität von Bauklotzanordnungen mithilfe verschiedener Unterstützungsmaßnahmen innerhalb einer kurzen Lerneinheit anregen lässt. Dabei wurden verschiedene materiale und verbale Unterstützungsmaßnahmen in Form von Fotos und gezielten sprachlichen Instruktionen in einem systematischen Vergleich gegenübergestellt. Die Ergebnisse weisen nach, dass bereits mit einer kurzen Lerneinheit ein Wissenszuwachs bei Siebenjährigen angeregt werden kann, insbesondere wenn sie durch Fotos und gezielte sprachliche Instruktionen unterstützt werden. Die Ergebnisse sind ein erster Schritt für die Entwicklung eines naturwissenschaftlichen Unterrichts zur Stabilität von Bauklotzanordnungen.

Perfluorocarboxylic acids (PFCA) are substances of anthropogenic origin and have been used for several decades. These compounds are a new class of environmental pollutants. Their high surface activity, thermal stability, amphipathicity and weak intermolecular interactions lead to persistence and bioaccumulation. Therefore, there is a great need for reliable analytical methods for detecting the presence and determination of concentration in both environmental samples and everyday products. GC-MS is a cost-effective alternative and supplement to established LC-MS/MS methods. The greatest challenge in the method development is the derivatization reaction. Many of the previously published derivatization reactions for PFCA are time consuming and require high reaction temperatures or toxic reagents. In the present dissertation, two new derivatization reactions for PFCA have been developed and optimized. The first part of the thesis shows the development and optimization of the reaction with triethylsilanol in water. In addition to optimizing the reaction, classical solid-phase extraction was modified to simplify the sample preparation. In the second part of the work, the reaction products of perfluorooctanoic acid (PFOA) with N,N-dimethylformamide dimethyl acetal (DMF-DMA) and -diethyl acetal (DMF-DEA) were identified. From these measurements, it follows that both DMF-DMA and DMF-DEA in the presence of PFOA form an iminium cation, which leads to salt formation. This PFOA salt react further in the GC injector and a corresponding amine is produced. In the last part of the thesis, an analytical method based on the DMF-DMA reaction was developed. The matrix effects have been described in detail. The method has been successfully applied for three different types of samples: dental floss, textiles and sewage sludge. The results were verified by LC-MS/MS analysis in an external laboratory. The differences between the PFCA values for a spiked sample measured by GC-MS and LC-MS/MS were less than 10%.

Warum kann ich mir nicht vorstellen, meine Haare wachsen zu lassen, insbesondere meine Körperhaare? Diese Frage und das damit verbundene Unbehagen motivierten mich 2016 zur Entwicklung meines Dissertationsprojektes. Die Suche nach einer Antwort führt zu einer Studie, die einen feministisch-phänomenologischen Erfahrungsbegriff zentral setzt. Bedeutsam für die Entwicklung eines solchen Begriffs sind die phänomenologischen Beiträge „Zur poststrukturalistischen Kritik an der Erfahrung im Kontext der feministischen Philosophie“ (Stoller 2005) von Silvia Stoller und „Phänomenologie, Poststrukturalismus und feministische Theorie. Zum Begriff der Erfahrung“ (Alcoff 1997) von Linda Martín Alcoff. Darauf aufbauend verfolgt das Dissertationsprojekt zunächst das Anliegen, Erfahrungen sichtbar zu machen, indem sie veranschaulicht und zur Sprache gebracht werden. Auf diese Weise wird es möglich, Erfahrungen hinterfragen zu können, um anschließend Antworten entwickeln zu können. Demnach beruhen mein Unvermögen, Körperhaare wachsen zu lassen, sowie das damit einhergehende Unbehagen darauf, eine drohende Erfahrung der Fremdheit mir selbst gegenüber abwenden zu wollen. Zu einer solchen Fremderfahrung würde es kommen, wenn ich durch meine Körperhaare damit konfrontiert werde, dass ich mir fremd bin. Jedoch um sich selbst kennenzulernen sind Menschen nach phänomenologischem Verständnis (vgl. Meyer-Drawe 2001: 141-142) auf andere Menschen angewiesen, da sie sich selbst erst durch andere bewusst werden können. Doch stellt es angesichts des gelebten Ideals der Haarlosigkeit (vgl. Labre 2002: 120-122, Strmljan 2018: 406) eine Herausforderung dar, meine drohende Fremderfahrung, aufgrund der Konfrontation mit meinen Körperhaaren, im Kontakt mit anderen Menschen zu überwinden, sodass ich eine solche Fremderfahrung vermeide, indem ich meine Körperhaare entferne. Als Resultat verbleibt mein Unbehagen darüber, dem Ideal der Haarlosigkeit zu entsprechen. Zu einer solchen Antwort gelange ich anhand einer Studie, die folgender Forschungsfrage folgt: Wie erfahren sich Menschen beim Waxing in einem Kosmetikstudio unter den Bedingungen der binären Geschlechterordnung? Dass die Erfahrungen in einem Kosmetikstudio erforscht werden, begründet sich damit, dass in einem solchen der Zugang zu Erfahrungen bei der Entfernung von Körperhaaren möglich wird. Körperhaare zu entfernen ist zwar ein alltäglicher Umgang mit Körpern, jedoch intim und persönlich, sodass ein Zugang schwierig wird. Eine Lösung stellt hierfür ein Kosmetikstudio dar. Als Praktikantin in dem Kosmetikstudio Beautystudio werden mir Erfahrungen beim Waxing – einer kosmetischen Technik der Haarentfernung – zugänglich. Auf solche Weise Daten zu erheben folgt dem ethnographischen Vorgehen der teilnehmenden Beobachtung. Forscher*innen nehmen beobachtend vor Ort teil und erheben Daten, indem sie Notizen, Protokolle und schließlich Studien erstellen. Mittels eines solchen Forschungsstils können Forscher*innen Erfahrungen in einer Studie zentral setzen, da sie so Erfahrungen selbst machen können und Zugang zu den Erfahrungen anderer erhalten (vgl. Amann/ Hirschauer 1997: 29-30, Breidenstein et al. 2013: 86-87, 103, 177-178). Im Zuge der Datenerhebung zeigt sich wiederum, dass im Umgang mit Körperhaaren die Bedingungen der binären Geschlechterordnung wirksam werden. Beispielsweise wird in vielen Situationen die dichotome Differenz zwischen Männern und Frauen betont, ohne dass es konkret für die kosmetische Anwendung notwendig zu sein scheint. So erklärt sich, dass für die Analyse und das Hinterfragen der zur Sprache gebrachten Erfahrungen ein geschlechtertheoretisches Konzept herangezogen wird, welches Erfahrungen hinsichtlich der Bedingungen der binären Geschlechterordnung befragen kann. Eine solche Betrachtung der Daten bietet Gesa Lindemanns Konzept „Der leiblich-affektiven Konstruktion des Geschlechts“ (1992). Basierend auf dem feministisch-phänomenologischen Erfahrungsbegriff, dem ethnographischen Vorgehen und dem Geschlechterkonzept Lindemann zeigt sich, dass Menschen beim Waxing erfahren (können), mit anderen Menschen verbunden und sich selbst unverbunden zu sein. Dabei wird die Haut zum Kristallisationspunkt der Verbindung zu anderen Menschen (und auch Apparaten). Durch die Berührungen wird einerseits Verbundenheit gestaltet und eine gegenseitige Zuwendung erfahrbar, andererseits wird diese aber auch unterbrochen, wenn durch das Waxing Schmerz zugefügt wird oder Menschen durch Blicke entblößt werden. So wird die Haut zum Medium zwischen den Erfahrungen der Verbundenheit und Unverbundenheit. (Hinweisen möchte ich an dieser Stelle, dass alle Namen und Orte anonymisiert sind. Demnach handelt es sich beim Beautystudio um den anonymisierten Namen des Kosmetikstudios, in welchem ich forschte. Auf diese Weise soll die Persönlichkeit der Kontaktpersonen im Feld gewahrt bleiben.) Literaturhinweise: Alcoff, Linda M. (1997): Phänomenologie, Poststrukturalismus und feministische Theorie. Zum Begriff der Erfahrung. In: Stoller, Silvia/ Vetter, Helmuth (Hg.): Phänomenologie und Geschlechterdifferenz. Wien: WUV-Universitäts-Verlag: 227-271. Amann, Klaus/ Hirschauer, Stefan (1997): Die Befremdung der eigenen Kultur. Ein Programm. In: Hirschauer, Stefan/ Amann, Klaus (Hg.): Die Befremdung der eigenen Kultur: Zur ethnographischen Herausforderung soziologischer Empirie. Frankfurt am Main: Suhrkamp Verlag: 7-52. Breidenstein, Georg/ Hirschauer, Stefan/ Kalthoff, Stefan/ Nieswand, Boris (2013): Ethnografie. Die Praxis der Feldforschung. Konstanz & München: UVK Verlagsgesellschaft Labre Peixoto, Magdala (2002): The Brazilian Wax: New Hairlessness Norm for Women? In: Journal of Communication Inquiry: 26 (2): 113-132. Lindemann, Gesa (1992): Die leiblich-affektive Konstruktion des Geschlechts. Für eine Mikrosoziologie des Geschlechts unter der Haut. In: Zeitschrift für Soziologie: 21 (5): 330-346. Meyer-Drawe, Käte (2001): Leiblichkeit und Sozialität. München: Wilhelm Fink Verlag. Stoller, Silvia (2005): Zur poststrukturalistischen Kritik an der Erfahrung im Kontext der feministischen Philosophie. In: Stoller, Silvia/ Vasterling, Veronica/ Fisher, Linda (Hg.): Feministische Phänomenologie und Hermeneutik. Würzburg: Königshausen & Neumann GmbH: 139-170. Strmljan, Alina (2018): Haare zum Schämen? Weibliche Körperbehaarung und ihre Entfernung – Normen, Tabus und Trivialisierungen. In: Breuss, Susanne (Hg.): Mit Haut und Haar. Frisieren, Rasieren, Verschönern. Wien: Metroverlag: 404-410.

In this thesis we examined the question whether personality traits of early child care workers influence process quality in preschool. Research has shown that in educational settings such as preschool, pedagogical quality affects children’s developmental outcome (e.g. NICHD, 2002; Peisner-Feinberg et al., 1999). A substantial part of pedagogical quality known to be vital in this respect is the interaction between teacher and children (e.g., Tietze, 2008). Results of prior classroom research indicate that the teachers’ personality might be an important factor for good teacher-child-interaction (Mayr, 2011). Thus, personality traits might play a vital role for the interaction in preschool. Therefore, the aims of this thesis were to a) identify pivotal personality traits of child care workers, b) assess ideal levels of the identified personality traits and c) examine the relationship between pivotal personality traits and process quality. On that account, we conducted two requirement analyses and a video study. The results of these studies showed that subject matter experts (parents, child care workers, lecturers) partly agreed as to which personality traits are pivotal for child care workers. Furthermore, the experts showed high consensus with regard to the minimum, ideal and maximum personality trait profiles. Furthermore, child care workers whose profiles lay closer to the experts’ ideal also showed higher process quality. In addition, regression analyses showed that the child care workers’ levels of the Big Two (Communion and Agency) related significantly to their process quality.

The history of human kind is characterized by social conflict. Every conflict can be the starting point of social change or the escalation into more destructive forms. The social conflict in regard to rising numbers of refugees and their acceptance that arose in most host countries in 2015 already took on destructive forms – in Germany, right-wing extremists attacked refugee shelters and even killed multiple people, including political leaders who openly supported refugees. Thus, incompatible expectancies and values of different parts of the society led to violent action tendencies, which tremendously threaten intergroup relations. Psychological research has developed several interventions in past decades to improve intergroup relations, but they fall short, for example, when it comes to the inclusion of people with extreme attitudes and to precisely differentiate potential prosocial outcomes of the interventions. Thus, this dissertation aimed to a) develop psychological interventions, that could also be applied to people with more extreme attitudes, thereby putting a special emphasis on collecting a diverse sample; b) gain knowledge about target- and outcome specific effects: Who benefits from which intervention and how can specific prosocial actions be predicted in order to develop interventions that guide needs-based actions; and c) shed light on potential underlying mechanisms of the interventions. The dissertation will be introduced by the socio-political background that motivated the line of research pursued, before providing an overview of the conceptualization of social conflicts and potential psychological inhibitors and catalyzers for conflict transformation. Based on past research on socio-psychological interventions and their limitations, the aims of the dissertation will be presented in more detail, followed by a short summary of each manuscript. Overall, the present thesis comprises four manuscripts that were summarized in the general discussion into a road map for social-psychological interventions to put them into a broader perspective. The road map aspires to provide recommendations for increasing – either approach-oriented or support-oriented actions – by the socio-psychological interventions for a variety of host society groups depending on their pre-existing attitude towards refugees. A Paradoxical Intervention targeting central beliefs of people with negative attitudes towards refugees influenced inhibitory and catalyzing factors for conflict transformation over the course of three experiments – thereby providing an effective tool to establish approach-oriented action tendencies, such as the willingness to get in contact with refugees. Further, the dissertation presents a novel mechanism – namely Cognitive Flexibility – which could explain the Paradoxical Interventions’ effect of past research. By positively affecting a context-free mindset, the Paradoxical Intervention could impact more flexible thought processes in general, irrespective of the topic tackled in the Paradoxical Intervention itself. For people with rather positive attitudes addressing emotions may increase specific support-oriented action tendencies. The dissertation provides evidence of a positive relation between moral outrage and hierarchy-challenging actions, such as solidarity-based collective action, and sympathy with prosocial hierarchy-maintaining support-oriented actions, such as dependency-oriented helping. These exclusive relations between specific emotions and action intentions provide important implications for the theorizing of emotion-behavior relations, as well as for practical considerations. In addition, a diversity workshop conducted with future diplomats showed indirect effects on solidarity-based collective action via diversity perception and superordinate group identification, thereby extending past research by including action intentions and going beyond the focus on grassroot-initiatives by presenting an implementable intervention for future leaders in a real world context. Taken together, this dissertation provides important insights for the development of socio-psychological interventions. By integrating a diverse sample, including members of institutions on meso- and macro-levels (non-governmental organizations and future politicians) of our society, this dissertation presents a unique multi-perspective of host society members on the social conflict of refugee acceptance and support. Thereby, this work contributes to theoretical and practical advancement of how social psychology can contribute not only to negative peace – by for example (indirectly) reducing support of violence against refugees – but also to positive peace – by for example investigating precursors of hierarchy-challenging actions that enable equal rights.

In the context of augmented reality we define tracking as a collection of methods to obtain the position and orientation (pose) of a user. By means of various displaying techniques, this ensures a correct visual overlay of graphical information onto the reality perceived. Precise results for calculation of the camera pose are gained by methods of image processing, usually analyzing the pixels of an image and extracing features, which can be recognized over the image sequence. However, these methods do not regard the process of image synthesis or at least in a very simplyfied way. In contrast, the class of model-based methods assumes a given 3D model of the observed scene. Based on the model data features can be identified to establish correspondences in the camera image. From these feature correspondences the camera pose is calculated. An interesting approach is the strategy of analysis-by-synthesis, regarding the computer graphics rendering process for extending the knowledge about the model by information from image synthesis and other environment variables. In this thesis the components of a tracking system are identified and further it is analyzed, to what extend information about the model, the rendering process and the environment can contribute to the components for improvement of the tracking process using analysis-by-synthesis. In particular, by using knowledge as topological information, lighting or perspective, the feature synthesis and correspondence finding should lead to visually unambiguous features that can be predicted and evaluated to be suitable for stable tracking of the camera pose.

Initial goal of the current dissertation was the determination of image-based biomarkers sensitive for neurodegenerative processes in the human brain. One such process is the demyelination of neural cells characteristic for Multiple sclerosis (MS) - the most common neurological disease in young adults for which there is no cure yet. Conventional MRI techniques are very effective in localizing areas of brain tissue damage and are thus a reliable tool for the initial MS diagnosis. However, a mismatch between the clinical fndings and the visualized areas of damage is observed, which renders the use of the standard MRI diffcult for the objective disease monitoring and therapy evaluation. To address this problem, a novel algorithm for the fast mapping of myelin water content using standard multiecho gradient echo acquisitions of the human brain is developed in the current work. The method extents a previously published approach for the simultaneous measurement of brain T1, T∗ 2 and total water content. Employing the multiexponential T∗ 2 decay signal of myelinated tissue, myelin water content is measured based on the quantifcation of two water pools (myelin water and rest) with different relaxation times. Whole brain in vivo myelin water content maps are acquired in 10 healthy controls and one subject with MS. The in vivo results obtained are consistent with previous reports. The acquired quantitative data have a high potential in the context of MS. However, the parameters estimated in a multiparametric acquisition are correlated and constitute therefore an ill-posed, nontrivial data analysis problem. Motivated by this specific problem, a new data clustering approach is developed called Nuclear Potential Clustering, NPC. It is suitable for the explorative analysis of arbitrary dimensional and possibly correlated data without a priori assumptions about its structure. The developed algorithm is based on a concept adapted from nuclear physics. To partition the data, the dynamic behavior of electrically even charged nucleons interacting in a d-dimensional feature space is modeled. An adaptive nuclear potential, comprised of a short-range attractive (Strong interaction) and a long-range repulsive term (Coulomb potential), is assigned to each data point. Thus, nucleons that are densely distributed in space fuse to build nuclei (clusters), whereas single point clusters are repelled (noise). The algorithm is optimized and tested in an extensive study with a series of synthetic datasets as well as the Iris data. The results show that it can robustly identify clusters even when complex configurations and noise are present. Finally, to address the initial goal, quantitative MRI data of 42 patients are analyzed employing NPC. A series of experiments with different sets of image-based features show a consistent grouping tendency: younger patients with low disease grade are recognized as cohesive clusters, while those of higher age and impairment are recognized as outliers. This allows for the definition of a reference region in a feature space associated with phenotypic data. Tracking of the individual's positions therein can disclose patients at risk and be employed for therapy evaluation.

Stream ecosystems are one of the most threatened ecosystems worldwide due to their exposure to diverse anthropogenic stressors. Pesticides appear to be the most relevant stressor for agricultural streams. Due to the current mismatch of modelled and measured pesticide concentrations, monitoring is necessary to inform risk assessment or improve future pesticide approvals. Knowing if biotic stress responses are similar across large scales and long time frames could ultimately help in estimating protective stressor thresholds. This thesis starts with an overview of entry pathways of pesticides to streams as well as the framework of current pesticide monitoring and gives an outline of the objectives of the thesis. In chapter 2, routine monitoring data based on grab sampling from several countries is analysed to identify the most frequently occurring pesticide mixtures. These mixtures are comprised of relatively low numbers of pesticides, of which herbicides are dominating. The detected pesticide mixtures differ between regions and countries, due to differences in the spectrum of analysed compounds and limits of quantification. Current routine monitoring does not include sampling during pesticide peaks associated with heavy rainfall events which likely influences the detected pesticide mixtures. In chapter 3, sampling rates of 42 organic pesticides for passive sampling are provided together with recommendations for the monitoring of field-relevant peaks. Using this information, in chapter 4 a pesticide gradient is established in an Eastern European region where agricultural intensity adjacent to sampled streams ranges from low to high. In contrast to current routine monitoring, rainfall events were sampled and a magnitude of pesticides were analysed. This led to the simultaneous detection of numerous pesticides of which one to three drive the pesticide toxicity. The toxicity, however, showed no relationship to the agricultural intensity. Using microcosms, the stress responses of fungal communities, the hyphomycetes, and the related ecosystem function of leaf decomposition, is investigated in chapter 5. Effects of a field-relevant fungicide mixture are examined across three biogeographical regions for three consecutive cycles of microbial leaf colonisation and decomposition. Despite different initial communities, stress responses as well as recoveries were similar across biogeographical regions, indicating a general pattern. Overall, this thesis contributes to an improved understanding of occurrence and concentrations of pesticides mixtures in streams, their monitoring and impact on an ecosystem function. We showed that estimated pesticide toxicities reach levels that affect non-target organisms and thereby potentially whole ecosystems. Routine monitoring, however, likely underestimates the threat by pesticides. Effects leading to a loss in biodiversity or functions in streams ecosystems can be reduced by reassessing approved pesticides with ongoing targeted monitoring and increased knowledge of effects caused by these pesticides.

The three biodegradable polymers polylactic acid (PLA), polyhydroxybutyrate (PHB) and polybutylene adipate terephthalate (PBAT) were coated with hydrogenated amorphous carbon layers (a-C:H) in the context of this thesis. A direct alignment of the sample surface to the source was chosen, resulting in the deposition of a robust, r-type a-C:H. At the same time, a partly covered silicon wafer was placed together with the polymers in the coating chamber and was coated. Silicon is a hard material and serves as a reference for the applied layers. Due to the hardness of the material, no mixed phase occurs between the substrate and the applied layer (no interlayer formation). In addition, the thickness of the applied layer can be estimated with the help of the silicon sample. The deposition of the layer was realized by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD). For the coating the samples were pre-treated with an oxygen plasma. Acetylene was used as precursor gas for the plasma coating. Coatings with increasing thickness in 50 nm steps from 0-500 nm were realised. The surface analysis was performed using several techniques: The morphology and layer stability were analyzed with scanning electron microscopy (SEM) measurements. The wettability was determined by contact angle technique. In addition, the contact angles provide macroscopic information about the bond types of the carbon atoms present on the surface. For microscopic analysis of the chemical composition of the sample and layer surfaces, diffuse reflectance Fourier transform infrared spectroscopy (DRIFT) as well as synchrotron based X-ray photon spectroscopy (XPS) and near edge X-ray absorption fine structure spectroscopy (NEXAFS) were used. All coated polymers showed several cases of layer failure due to internal stress in the layers. However, these were at different layer thicknesses, so there was a substrate effect. In addition, it is visible in the SEM images that the coatings of PLA and PHB can cause the applied layer to wave, the so-called cord buckling. This does not occur with polymer PBAT, which indicates a possible better bonding of the layer to the polymer. The chemical analyses of the layer surfaces show for each material a layer thickness dependent ratio of sp² to sp³ bonds of carbon, which alternately dominate the layer. In all polymers, the sp³ bond initially dominates, but the sp² to sp³ ratio changes at different intervals. Although the polymers were coated in the same plasma, i.e. the respective layer thicknesses (50 nm, 100 nm, ...) were applied in the same plasma process, the respective systems differed considerably from each other. A substrate effect is therefore demonstrably present. In addition, it was found that a change in the dominant bond from sp³ to sp² is an indication ofan upcoming layer failure of the a-C:H layer deposited on the polymer. In the case of PLA, this occurs immediately with change to sp² as the dominant bond; in the case of PHB and PBAT, this occurs with different delay to increased layer thicknesses (at PHB 100 nm, at PBAT approx. 200 nm. Overall, this thesis shows that there is a substrate effect in the coating of the biodegradable polymers PLA, PHB and PBAT, since despite the same coating there is a different chemical composition of the surface at the respective layer thicknesses. In addition, a layer failure can be predicted by analyzing the existing bond.

Data-minimization and fairness are fundamental data protection requirements to avoid privacy threats and discrimination. Violations of data protection requirements often result from: First, conflicts between security, data-minimization and fairness requirements. Second, data protection requirements for the organizational and technical aspects of a system that are currently dealt with separately, giving rise to misconceptions and errors. Third, hidden data correlations that might lead to influence biases against protected characteristics of individuals such as ethnicity in decision-making software. For the effective assurance of data protection needs, it is important to avoid sources of violations right from the design modeling phase. However, a model-based approach that addresses the issues above is missing. To handle the issues above, this thesis introduces a model-based methodology called MoPrivFair (Model-based Privacy & Fairness). MoPrivFair comprises three sub-frameworks: First, a framework that extends the SecBPMN2 approach to allow detecting conflicts between security, data-minimization and fairness requirements. Second, a framework for enforcing an integrated data-protection management throughout the development process based on a business processes model (i.e., SecBPMN2 model) and a software architecture model (i.e., UMLsec model) annotated with data protection requirements while establishing traceability. Third, the UML extension UMLfair to support individual fairness analysis and reporting discriminatory behaviors. Each of the proposed frameworks is supported by automated tool support. We validated the applicability and usability of our conflict detection technique based on a health care management case study, and an experimental user study, respectively. Based on an air traffic management case study, we reported on the applicability of our technique for enforcing an integrated data-protection management. We validated the applicability of our individual fairness analysis technique using three case studies featuring a school management system, a delivery management system and a loan management system. The results show a promising outlook on the applicability of our proposed frameworks in real-world settings.

Microbial pollution of surface waters poses substantial risks for public health, amongst others during recreational use. Microbial pollution was studied at selected sampling sites in rivers Rhine, Moselle and Lahn (Germany) on the basis of commonly used fecal indicator organisms (FIO) indicating bacterial (Escherichia coli, intestinal enterococci) and viral (somatic coliphages) fecal contamination. In addition, blaCTX-Mantibiotic resistance genes (ARG) were quantified at twosites in river Lahn and were used as markers for tracking the spread of antibiotic resistance in the aquatic environment. The impact of changes in climate-related parameters on FIO was examined by studying monitoring results of contrasting flow conditions at rivers Rhine and Moselle. Analyses at all studied river sites clearly indicate that high discharge and precipitation enhance the influx of FIO, ARG and thus potentially (antibiotic resistant) pathogens into rivers. In contrast, a decrease in hygienic microbial pollution was observed under high solar irradiation and increasing water temperatures. Based on identified contributing key factors, multiple linear regression (MLR) models for five sites at a stretch of river Lahn were established that allow a timely assessment of fecal indicator abundances. An interaction between abiotic and biotic factors (i.e. enhanced grazing pressure) considerably contributed to the formation of seasonal patterns among FIO abundances. This was enhanced during extraordinary low flow conditions in rivers with pronounced trophic interactions, clearly hampering a transfer of model approaches between rivers of different biological and hydrological characteristics. Bacterial indicatorswere stronger influenced by grazing pressure than phages. Hence, bacterial indicators alone do not sufficiently describe viral pollution in rivers. BlaCTX-Mgenes were omnipresent in Lahn River water and corresponded to distribution patterns of FIO, indicating fecal sources. Agriculture and waste watertreatment plant effluents contributed to ARG loads and participants in non-bathing water sports were found to be at risk of ingesting antibiotic resistant bacteria (ARB) including ARG, bearing the risk of infection or colonization. Results of the present study highlight the need to be aware of such risks not only in designated bathing waters. ARG abundance at both riverine sampling sites could largely be explained by E. coliabundance and may thus also be incorporated into multiple regression models using E. colispecific environmental predictors. It can be expected that the frequency of short-term microbial pollution events will increase over the next decades due to climate change. Several challenges were identified with regard to the implementation of early warning systems to protect the public from exposure to pathogens in rivers. Most importantly, the concept of the Bathing Water Directive (Directive 2006/7/EC) itself as well as the lack of harmonization in the regulatory framework at European Union (EU) level are major drawbacks and require future adjustments to reliably manage health risks related to microbial water pollution in waters used in multifunctional ways.

Lastkraftwagen werden weltweit in verschiedenen Konfigurationen für den Transport von Gütern und für Spezialanwendungen genutzt. Das sichere Navigieren solcher Großfahrzeuge stellt eine herausfordernde Aufgabe für den Fahrer und unter Umständen für automatische Steuerungssysteme, z. B. im semi-autonomen oder autonomen Betrieb, dar. Insbesondere in kinematisch schwierigen Situationen, auf unebenem Untergrund oder bei engen Platzverhältnissen steigt die Komplexität des sicheren Steuerns. Umso verwunderlicher ist es, dass unterstützende Systeme, welche die speziellen Belange von LKW und insbesondere LKW-Gespannen adressieren, im Vergleich zum Angebot auf dem PKW-Markt nur in rudimentärem Maß angeboten werden. Das Gefahrenpotential, dass von Großfahrzeugen ausgeht, wird zunehmend in der aktuellen Tagespolitik diskutiert. Unter anderem wird die verpflichtende Einführung von Fahrerassistenzsystemen gefordert. In dieser Arbeit werden zwei Themen behandelt, die sich mit den speziellen Anforderungen von Nutzfahrzeugen befassen. Im ersten Themenblock wird die Erfassung der Artikulation in einem LKW-Anhänger-Gespann mit Drehschemelanhänger bearbeitet. Dabei wird ein neuartiges Verfahren vorgestellt, das auf an der Universität Koblenz-Landau geleisteten Vorarbeiten aufbaut. Es ermöglicht die Erfassung von Knickwinkeln in mehreren Dimensionen und ist daher auch für den Einsatz auf unebenem Grund, wie beispielsweise in Baustellen- oder Agrarszenarien geeignet. Das Verfahren nutzt dabei eine Kamera und ein künstliches Muster, um den Gespannzustand zu ermitteln. Im zweiten Bereich wird die Umfeldvisualisierung durch eine Vogelperspektivenansicht thematisiert. Herkömmliche Systeme weisen systembedingte Verzerrungen auf, die unnatürlich wirkende Ansichten zur Folge haben. Diesem Problem wird durch die Entwicklung einer neuen Herangehensweise begegnet: Mit den Tiefendaten von Stereokameras wird eine Umgebungsmodellierung realisiert, die im nächsten Schritt perspektivisch korrekt mit Kamerabildern fusioniert wird. Mittels einer speziell für diesen Fall erweiterten Stereo-Hinderniserkennung wird zudem eine zusätzliche Umfeldüberwachung ermöglicht. Die beiden in dieser Dissertation vorgestellten Verfahren beinhalten grundlegende Arbeiten, die für die Entwicklung maßgeschneiderter Assistenzsysteme für LKW angewandt werden können.

Because silver nanoparticles (Ag NPs) are broadly applied in consumer products, their leaching will result in the continuous release of Ag NPs into the natural aquatic environment. Therefore, bacterial biofilms, as the prominent life form of microorganisms in the aquatic environment, are most likely confronted with Ag NPs as a pollutant stressor. Notwithstanding the significant ecological relevance of bacterial biofilms in aquatic systems, and though Ag NPs are expected to accumulate within these biofilms in the environment, the knowledge on the environmental and ecological impact of Ag NPs, is still lagging behind the industrial growth of nanotechnology. Consequently, aim of this thesis was to perform effect assessment of Ag NP exposure on bacterial biofilms with ambient Ag NPs concentrations and under environmentally relevant conditions. Therefore, a comprehensive set of methods was applied in this work to study if and how Ag NPs of two different sizes (30 and 70 nm) affect bacterial biofilms i.e. both monospecies biofilms and freshwater biofilms in environmentally relevant concentrations (600 - 2400 µg l-1). Within the first part of this work, a newly developed assay to test the mechanical stability of monospecies biofilms of the freshwater model bacterium Aquabacterium citratiphilum was validated. In the first study, to investigate the impact of Ag NPs on the mechanical stability of bacterial biofilms, sublethal effects on the mechanical stability of the biofilms were observed with negative implications for biostabilization. Furthermore, as it is still challenging to monitor the ecotoxicity of Ag NPs in natural freshwater environments, a mesocosm study was performed in this work to provide the possibility for the detailed investigation of effects of Ag NPs on freshwater biofilms under realistic environmental conditions. By applying several approaches to analyze biofilms as a whole in response to Ag NP treatment, insights into the resilience of bacterial freshwater biofilms were obtained. However, as revealed by t-RFLP fingerprinting combined with phylogenetic studies based on the 16S gene, a shift in the bacterial community composition, where Ag NP-sensitive bacteria were replaced by more Ag NP-tolerant species with enhanced adaptability towards Ag NP stress was determined. This shift within the bacterial community may be associated with potential detrimental effects on the functioning of these biofilms with respect to nutrient loads, transformation and/or degradation of pollutants, and biostabilization. Overall, bringing together the key findings of this thesis, 4 general effect mechanisms of Ag NP treatment have been identified, which can be extrapolated to natural freshwater biofilms i.e. (i) the identification of Comamonadaceae as Ag NP-tolerant, (ii) a particular resilient behaviour of the biofilms, (iii) the two applied size fractions of Ag NPs exhibited similar effects independent of their sizes and their synthesis method, and (iv) bacterial biofilms show a high uptake capacity for Ag NPs, which indicates cumulative enrichment.

The analysis of three-dimensional and complex motion sequences of human gait and therefore the most important question of kenesiology ”why are we falling?” is the essence of this paper. The gerontology and its science of movement is currently limited to simple and one-dimensional methods and models. An extensive literature research shows the latest state of research of the three common methods to determine the stability of human gait. To assess the margin of stability, local stability and orbital stability it is shown, how those methods are applicable to evaluate the subject’s ability to recover from any disturbences of the subject’s gait. Based on this assessment and the method’s advantages and disadvantages a new method will be derived that allows spatial analysis of dynamic instability of linear and non-linear human gait. A motion capture system and the timed up and go test serve as a basis for this new method and will be explained. A numerical approximation to optimise the number of markers within a marker-set of a motion capture analysis and its maximum correlation with the full-body-marker-set will be given. This simplification is very helpful for further clinical or scientific research. To validate the new method a trial with subjects will be shown and discussed. New appreciable variables and snapshots of specific situations during the gait offer new and different interpretations of the human gait. The new method is the most applicable and appropriate assessment of human gait and the individual development of the human gait while aging, as well as to detect and prevent falling and associated injuries. Especially directional change of a non-linear gait become assessable with the new method.

The European landscape is dominated by intensive agriculture which leads to widespread impact on the environment. The frequent use of agricultural pesticides is one of the major causes of an ongoing decline in flower-visiting insects (FVIs). The conservation of this ecologically diverse assemblage of mobile, flying insect species is required by international and European policy. To counteract the decrease in species numbers and their abundances, FVIs need to be protected from anthropogenic stressors. European pesticide risk assessment was devised to prevent unacceptable adverse consequences of pesticide use on FVIs. However, there is an ongoing discussion by scientists and policy-makers if the current risk assessment actually provides adequate protection for FVI species. The first main objective of this thesis was to investigate pesticide impact on FVI species. The scientific literature was reviewed to identify groups of FVIs, summarize their ecology, and determine their habitat. This was followed by a synthesis of studies about the exposure of FVIs in their habitat and subsequent effects. In addition, the acute sensitivity of one FVI group, bee species, to pesticides was studied in laboratory experiments. The second main objective was to evaluate the European risk assessment for possible deficits and propose improvements to the current framework. Regulatory documents were screened to assess the adequacy of the guidance in place in light of the scientific evidence. The suitability of the honey bee Apis mellifera as the currently only regulatory surrogate species for FVIs was discussed in detail. The available scientific data show that there are far more groups of FVIs than the usually mentioned bees and butterflies. FVIs include many groups of ecologically different species that live in the entire agricultural landscape. Their habitats in crops and adjacent semi-natural areas can be contaminated by pesticides through multiple pathways. Environmentally realistic exposure of these habitats can lead to severe effects on FVI population parameters. The laboratory studies of acute sensitivity in bee species showed that pesticide effects on FVIs can vary greatly between species and pesticides. The follow-up critical evaluation of the European FVI risk assessment revealed major shortcomings in exposure and effect assessment. The honey bee proved to be a sufficient surrogate for bee species in lower tier risk assessment. Additional test species may be chosen for higher tier risk assessment to account for ecological differences. This thesis shows that the ecology of FVIs should generally be considered to a greater extent to improve the regulatory process. Data-driven computational approaches could be used as alternative methods to incorporate ecological trait data in spatio-temporal scenarios. Many open questions need to be answered by further research to better understand FVI species and promote necessary changes to risk assessment. In general, other FVI groups than bees need to be investigated. Furthermore, comprehensive data on FVI groups and their ecology need to be collected. Contamination of FVI habitat needs to be linked to exposure of FVI individuals and ecologically complex effects on FVI populations should receive increased attention. In the long term, European FVI risk assessment would benefit from shifting its general principles towards more scientifically informed regulatory decisions. This would require a paradigm shift from arbitrary assumptions and unnecessarily complicated schemes to a substantiated holistic framework.

Engineered inorganic nanoparticles (EINPs) are produced and utilized on a large scale and will end up in surface waters. Once in surface waters, EINPs are subjected to transformations induced by environmental processes altering the particles’ fate and inherent toxicity. UV irradiation of photoactive EINPs is defined as one effect-inducing pathway, leading to the formation of reactive oxygen species (ROS), increasing EINP toxicity by exerting oxidative stress in aquatic life. Simultaneously, UV irradiation of photoactive EINP alters the toxicity of co-occurring micropollutants (e.g. pesticides) by affecting their degradation. The presence of natural organic matter (NOM) reduces the agglomeration and sedimentation of EINPs, extending the exposure of pelagic species, while delaying the exposure of benthic species living in and on the sediment, which is suggested as final sink for EINPs. However, the joint impact of NOM and UV irradiation on EINP-induced toxicity, but also EINP-induced degradation of micropollutants, and the resulting risk for aquatic biota, is poorly understood. Although potential effects of EINPs on benthic species are increasingly investigated, the importance of exposure pathways (waterborne or dietary) is unclear, along with the reciprocal pathway of EINPs, i.e. the transport back from aquatic to terrestrial ecosystems. Therefore, this thesis investigates: (i) how the presence of NOM affects the UV-induced toxicity of the model EINP titanium dioxide (nTiO2) on the pelagic organism Daphnia magna, (ii) to which extent UV irradiation of nTiO2 in the presence and absence of NOM modifies the toxicity of six selected pesticides in D. magna, (iii) potential exposure pathway dependent effects of nTiO2 and silver (nAg) EINPs on the benthic organism Gammarus fossarum, and (iv) the transport of nTiO2 and gold EINPs (nAu) via the merolimnic aquatic insect Chaetopteryx villosa back to terrestrial ecosystems. nTiO2 toxicity in D. magna increased up to 280-fold in the presence of UV light, and was mitigated by NOM up to 12-fold. Depending on the pesticide, UV irradiation of nTiO2 reduced but also enhanced pesticide toxicity, by (i) more efficient pesticide degradation, and presumably (ii) formation of toxic by-products, respectively. Likewise, NOM reduced and increased pesticide toxicity, induced by (i) protection of D. magna against locally acting ROS, and (ii) mitigation of pesticide degradation, respectively. Gammarus’ energy assimilation was significantly affected by both EINPs, however, with distinct variation in direction and pathway dependence between nTiO2 and nAg. EINP presence delayed C. villosa emergence by up to 30 days, and revealed up to 40% reduced lipid reserves, while the organisms carried substantial amounts of nAu (~1.5 ng/mg), and nTiO2 (up to 2.7 ng/mg). This thesis shows, that moving test conditions of EINPs towards a more field-relevant approach, meaningfully modifies the risk of EINPs for aquatic organisms. Thereby, more efforts need to be made to understand the relative importance of EINP exposure pathways, especially since a transferability between different types of EINPs may not be given. When considering typically applied risk assessment factors, adverse effects on aquatic systems might already be expected at currently predicted environmental EINP concentrations in the low ng-µg/L range.

Nowadays, almost any IT system involves personal data processing. In such systems, many privacy risks arise when privacy concerns are not properly addressed from the early phases of the system design. The General Data Protection Regulation (GDPR) prescribes the Privacy by Design (PbD) principle. As its core, PbD obliges protecting personal data from the onset of the system development, by effectively integrating appropriate privacy controls into the design. To operationalize the concept of PbD, a set of challenges emerges: First, we need a basis to define privacy concerns. Without such a basis, we are not able to verify whether personal data processing is authorized. Second, we need to identify where precisely in a system, the controls have to be applied. This calls for system analysis concerning privacy concerns. Third, with a view to selecting and integrating appropriate controls, based on the results of system analysis, a mechanism to identify the privacy risks is required. Mitigating privacy risks is at the core of the PbD principle. Fourth, choosing and integrating appropriate controls into a system are complex tasks that besides risks, have to consider potential interrelations among privacy controls and the costs of the controls. This thesis introduces a model-based privacy by design methodology to handle the above challenges. Our methodology relies on a precise definition of privacy concerns and comprises three sub-methodologies: model-based privacy analysis, modelbased privacy impact assessment and privacy-enhanced system design modeling. First, we introduce a definition of privacy preferences, which provides a basis to specify privacy concerns and to verify whether personal data processing is authorized. Second, we present a model-based methodology to analyze a system model. The results of this analysis denote a set of privacy design violations. Third, taking into account the results of privacy analysis, we introduce a model-based privacy impact assessment methodology to identify concrete privacy risks in a system model. Fourth, concerning the risks, and taking into account the interrelations and the costs of the controls, we propose a methodology to select appropriate controls and integrate them into a system design. Using various practical case studies, we evaluate our concepts, showing a promising outlook on the applicability of our methodology in real-world settings.

The bio-insecticide Bacillus thuringiensis israelensis (Bti) has worldwide become the most commonly used agentin mosquito control programs that pursue two main objectives: the control of vector-borne diseases and the reduction of nuisance, mainly coming frommosquitoes that emerge in large quantities from seasonal wetlands. The Upper Rhine Valley, a biodiversity hotspot in Germany, has been treated withBti for decades to reduce mosquito-borne nuisance and increase human well-being.Although Btiis presumed to be an environmentally safe agent,adverse effects on wetland ecosystems are still a matter of debate especially when it comes to long-term and indirect effects on non-target organisms. In light of the above, this thesis aims at investigating direct and indirect effects of Bti-based mosquito control on non-target organisms within wetland food chains.Effects were examinedin studies with increasingeco(toxico)logical complexity, ranging from laboratory over mesocosm to field approaches with a focus on the non-biting Chironomidae and amphibian larvae (Rana temporaria, Lissotriton sp.).In addition, public acceptance of environmentally less invasive alternative mosquito control methods was evaluated within surveys among the local population. Chironomids were the most severely affected non-target aquatic invertebrates. Bti substantially reduced larval and adult chironomid abundances and modified their species composition. Repeated exposures to commonly used Bti formulations induced sublethal alterations of enzymatic biomarkers activityin frog tadpoles. Bti-induced reductions of chironomid prey availability indirectly decreased body size of newts at metamorphosis and increased predation on newt larvae in mesocosm experiments. Indirect effects of severe reductions in midge biomassmight equally be passed through aquatic but also terrestrial food chains influencing predators of higher trophic levels. The majority ofaffectedpeople in the Upper Rhine Valley expressed a high willingness to contributefinancially to environmentally less harmful mosquito control.Alternative approaches could still include Bti applications excepting treatment of ecologically valuable areas. Potentially rising mosquito levels could be counteracted with local acting mosquito traps in domestic and urban areas because mosquito presence was experienced as most annoying in the home environment. As Bti-based mosquito control can adversely affect wetland ecosystems, its large-scale applications, including nature conservation areas, should be considered more carefully to avoid harmful consequences for the environmentat the Upper Rhine Valley.This thesis emphasizesthe importance to reconsiderthe current practice of mosquito control and encourage research on alternative mosquito control concepts that are endorsed by the local population. In the context ofthe ongoing amphibian and insect declinesfurther human-induced effects onwetlands should be avoided to preserve biodiversity in functioning ecosystems.

In der vorliegenden Studie geht es um den möglichen und tatsächlichen Beitrag von sogenannten Geschäftsmodellen im Kontext eines reflexiven Bildungsmanagements im Feld der wissenschaftlichen Weiterbildung an (öffentlichen) Hochschulen in Deutschland. Im Anschluss an Behrmann (2006) wird ein reflexives Bildungsmanagement verwendet, um mögliche strategische und entwicklungsrelevante Orientierungen für die strategische (Neu-)Positionierung von Weiterbildungseinrichtungen bzw. reflexive Entwicklung von Hochschulen im Handlungs- bzw. Geschäftsfeld der wissenschaftlichen Weiterbildung zu strukturieren. In diesem Zusammenhang unterstützen Geschäftsmodelle die Realisierung des (Weiter-)Bildungsauftrags von (öffentlichen) Hochschulen bzw. von deren Weiterbildungseinrichtungen. Diese möglichen Orientierungen wurden im Rahmen von qualitativen Inhaltsanalysen nach Kuckartz (2016) auf der Grundlage von visualisierten Gruppendiskussionen nach Kühl (2009) rekonstruiert. Der Feldzugang erfolgte mit Unterstützung der Deutschen Gesellschaft für wissenschaftliche Weiterbildung und Fernstudium e.V. (DGWF).

This dissertation deals with the opportunities and restrictions that parties face in an election campaign at the supranational level of the EU. Using communication science concepts of agenda-setting (focus: media) and agenda-building (focus: political parties), the first part of the study is based on the election campaign for the European Parliament (EP) in 2014. It analyses to what extent political parties put the EU on the agenda. Second, it is examined whether parties have used their structural advantage of being able to influence the media agenda at the supranational level during the election campaign in the context of the EP election campaign. Third, it is examined whether parties can gain an advantage for the visibility of their campaigns by rejecting EU integration and the associated conflictual communication. Fourth and final, it will be explored whether agenda-building can influence the rankings of specific policy issues on the media agenda in the European context. First, the analyses show that a European political focus of election campaign communication can no longer be found only on the part of the small (eurosceptic) parties. Second, parties have a good chance of being present in media coverage if the they pursue a European political focus in their campaign communication. Third, a negative tone in party communication turns out not to be decisive for the parties' visibility in the election campaign. Fourth, a clear positioning on political issues also prepares parties for restrictions of the further development of a European thematic agenda. After a discussion of these results, the paper concludes with an assessment of the analysis limitations and an outlook on further research approaches.

Im Zentrum der Untersuchung steht die Entwicklung des künstlerischen Siebdrucks in Deutschland seit dem Zweiten Weltkrieg. Nach der thematischen Einführung und einer ersten kritischen Bestandsaufnahme der Forschung zum Siebdruck wird im Folgenden der Verlauf und die methodische Vorgehensweise der Arbeit verdeutlicht. Im zweiten Kapitel „Etablierung einer künstlerischen Technik“ wird zuerst die Geschichte des Siebdrucks dem Rahmen dieser Arbeit gemäß nachgezeichnet. Nachfolgend wird in einem Unterkapitel dargestellt, wie sich die Serigrafie als künstlerisches Verfahren parallel zum industriellen Siebdruck etablierte. In der Folge wendet sich die Untersuchung der Entstehung und Entwicklung des künstlerischen Siebdrucks in Deutschland zu. Dabei wird Willi Baumeister als Beispiel für die erste Generation von Künstlern in Deutschland herangezogen, die sich mit der Serigrafie beschäftigte. Im nächsten Schritt wird ein Überblick zu den Willi Baumeister nachfolgenden deutschen bzw. deutschsprachigen Serigrafie–Künstlern präsentiert. In dem sich anschließenden Exkurs-Kapitel liegt der Schwerpunkt auf der Zusammenarbeit zwischen Künstler und Drucker. Dabei werden an Beispielen namhafter Drucker wie Luitpold Domberger und Hans-Peter Haas unter anderem Einflüsse der Drucker auf die Entstehung und den Ausdruck der Kunstwerke aufgezeigt.Nach einer Einführung in die Entstehung und Geschichte der Serigrafie in Deutschland und einem ersten Überblick über deutsche Serigrafie-Künstler wird im vierten Kapitel der Einsatz der Serigrafie-Technik bei verschiedenen Künstlern aus unterschiedlichen Zeiträumen eingehend untersucht. Besonderes Augenmerk gilt dabei dem Einfluss der Technik auf die Ausdrucksmöglichkeiten und Inhalte der Werke, die Anwendung innerhalb einer und verschiedener Kunstrichtungen sowie die Experimente, die mit der Siebdrucktechnik gemacht wurden. Dazu werden Werke ausgewählter Künstler analysiert. Im Fokus stehen Künstler der Pop Art, des Neuen und des Kritischen Realismus, der Abstrakten und Konkreten Kunst. Ferner werden Künstler, deren Werk durch einen expressiven, bisweilen primitiven Charakter geprägt ist, in die Betrachtung mit einbezogen. Eine weitere Gruppe bilden Künstler, die die Serigrafie in einen Zusammenhang zur Architektur und zum öffentlichen Raum stellen. Die aus der Untersuchung hervorgehenden Ergebnisse dienen insbesondere dazu, die Charakteristika der Technik in ihrer künstlerischen Verwendung herauszustellen und Aspekte einer künstlerisch motivierten Weiterentwicklung aufzuzeigen. Die Entwicklung des druckgraphischen Werkes und der Technik von Gerd Winner werden in Kapitel 5 eingehend untersucht. Auf diese Weise lässt sich eine systematische, nicht rein formale, sondern ästhetische und inhaltliche Darstellung der Serigrafie in Deutschland erstellen. Ein besonderes Augenmerk liegt dabei auf der Frage, wie sich die Technik und deren Neuerungen auf den Inhalt auswirkten.

Sustainable water management requires methods for assessing ecological stream quality. Many years of limnological research are needed to provide a basis for developing such methods. However, research of this kind is still lacking in Turkey. Therefore, the aim of this doctoral thesis was to provide basic research in the field of aquatic ecology and to present methods for the assessment of ecological stream quality based on benthic invertebrates. For this purpose, I selected 17 tributaries of the Euphrates with a similar typology/water order and varying levels of pollution or not affected by pollution at all. The characterisation of the natural mountain streams was the first important step in the analysis of ecological quality. Based on community indices, I found that the five selected streams had a very good ecological status. I also compared the different biological indications, collected on two occasions ¬– once in spring (May) and once in autumn (September) – to determine the optimal sampling time. The macroinvertebrate composition differed considerably between the two seasons, with the number of taxa and Shannon index being significantly higher in autumn than in spring. In the final step, I examined the basal resources of the macroinvertebrates in the reference streams with an isotope analysis. I found that FPOM and biofilm were the most relevant basal resources of benthic invertebrates. Subsequently, based on the similarity of their community structures, I divided the 17 streams into three quality classes, supported by four community indices (EPT [%], EPTCBO [%], number of individuals, evenness). In this process, 23 taxa were identified as indicators for the three quality classes. In the next step, I presented two new or adapted indices for the assessment of quality class. Firstly, I adapted the Hindu Kush-Himalaya biotic index to the catchment area of the Euphrates and created a new, ecoregion-specific score list (Euph-Scores) for 93 taxa. The weighted ASPT values, which were renamed the Euphrates Biotic Score (EUPHbios) in this study, showed sharper differentiations of quality classes compared to the other considered ASPT values. Thus, this modified index has proved to be very effective and easy to implement in practical applications. As a second biological index, I suggested the proportion of habitat specialists. To calculate this index, the habitat preferences of the 20 most common benthic invertebrates were identified using the new habitat score. The proportion of habitat specialists differed significantly among the three quality classes with higher values in natural streams than in polluted streams. The methods and results presented in this doctoral thesis can be used in a multi-metric index for a Turkish assessment programme.