TY - THES A1 - Hesse, Günter T1 - A benchmark for enterprise stream processing architectures T1 - Ein Benchmark für Architekturen zur Datenstromverarbeitung im Unternehmenskontext N2 - Data stream processing systems (DSPSs) are a key enabler to integrate continuously generated data, such as sensor measurements, into enterprise applications. DSPSs allow to steadily analyze information from data streams, e.g., to monitor manufacturing processes and enable fast reactions to anomalous behavior. Moreover, DSPSs continuously filter, sample, and aggregate incoming streams of data, which reduces the data size, and thus data storage costs. The growing volumes of generated data have increased the demand for high-performance DSPSs, leading to a higher interest in these systems and to the development of new DSPSs. While having more DSPSs is favorable for users as it allows choosing the system that satisfies their requirements the most, it also introduces the challenge of identifying the most suitable DSPS regarding current needs as well as future demands. Having a solution to this challenge is important because replacements of DSPSs require the costly re-writing of applications if no abstraction layer is used for application development. However, quantifying performance differences between DSPSs is a difficult task. Existing benchmarks fail to integrate all core functionalities of DSPSs and lack tool support, which hinders objective result comparisons. Moreover, no current benchmark covers the combination of streaming data with existing structured business data, which is particularly relevant for companies. This thesis proposes a performance benchmark for enterprise stream processing called ESPBench. With enterprise stream processing, we refer to the combination of streaming and structured business data. Our benchmark design represents real-world scenarios and allows for an objective result comparison as well as scaling of data. The defined benchmark query set covers all core functionalities of DSPSs. The benchmark toolkit automates the entire benchmark process and provides important features, such as query result validation and a configurable data ingestion rate. To validate ESPBench and to ease the use of the benchmark, we propose an example implementation of the ESPBench queries leveraging the Apache Beam software development kit (SDK). The Apache Beam SDK is an abstraction layer designed for developing stream processing applications that is applied in academia as well as enterprise contexts. It allows to run the defined applications on any of the supported DSPSs. The performance impact of Apache Beam is studied in this dissertation as well. The results show that there is a significant influence that differs among DSPSs and stream processing applications. For validating ESPBench, we use the example implementation of the ESPBench queries developed using the Apache Beam SDK. We benchmark the implemented queries executed on three modern DSPSs: Apache Flink, Apache Spark Streaming, and Hazelcast Jet. The results of the study prove the functioning of ESPBench and its toolkit. ESPBench is capable of quantifying performance characteristics of DSPSs and of unveiling differences among systems. The benchmark proposed in this thesis covers all requirements to be applied in enterprise stream processing settings, and thus represents an improvement over the current state-of-the-art. N2 - Data Stream Processing Systems (DSPSs) sind eine Schlüsseltechnologie, um kontinuierlich generierte Daten, wie beispielsweise Sensormessungen, in Unternehmensanwendungen zu integrieren. Die durch DSPSs ermöglichte permanente Analyse von Datenströmen kann dabei zur Überwachung von Produktionsprozessen genutzt werden, um möglichst zeitnah auf ungewollte Veränderungen zu reagieren. Darüber hinaus filtern, sampeln und aggregieren DSPSs einkommende Daten, was die Datengröße reduziert und so auch etwaige Kosten für die Datenspeicherung. Steigende Datenvolumen haben in den letzten Jahren den Bedarf für performante DSPSs steigen lassen, was zur Entwicklung neuer DSPSs führte. Während eine große Auswahl an verfügbaren Systemen generell gut für Nutzer ist, stellt es potentielle Anwender auch vor die Herausforderung, das für aktuelle und zukünftige Anforderungen passendste DSPS zu identifizieren. Es ist wichtig, eine Lösung für diese Herausforderung zu haben, da das Austauschen von einem DSPS zu teuren Anpassungen oder Neuentwicklungen der darauf laufenden Anwendungen erfordert, falls für deren Entwicklung keine Abstraktionsschicht verwendet wurde. Das quantitative Vergleichen von DSPSs ist allerdings eine schwierige Aufgabe. Existierende Benchmarks decken nicht alle Kernfunktionalitäten von DSPSs ab und haben keinen oder unzureichenden Tool-Support, was eine objektive Ergebnisberechnung hinsichtlich der Performanz erschwert. Zudem beinhaltet kein Benchmark die Integration von Streamingdaten und strukturierten Geschäftsdaten, was ein besonders für Unternehmen relevantes Szenario ist. Diese Dissertation stellt ESPBench vor, einen neuen Benchmark für Stream Processing-Szenarien im Unternehmenskontext. Der geschäftliche Kontext wird dabei durch die Verbindung von Streamingdaten und Geschäftsdaten dargestellt. Das Design von ESPBench repräsentiert Szenarien der realen Welt, stellt die objektive Berechnung von Benchmarkergebnissen sicher und erlaubt das Skalieren über Datencharakteristiken. Das entwickelte Toolkit des Benchmarks stellt wichtige Funktionalitäten bereit, wie beispielsweise die Automatisierung den kompletten Benchmarkprozesses sowie die Überprüfung der Abfrageergebnisse hinsichtlich ihrer Korrektheit. Um ESPBench zu validieren und die Anwendung weiter zu vereinfachen, haben wir eine Beispielimplementierung der Queries veröffentlicht. Die Implementierung haben wir mithilfe des in Industrie und Wissenschaft eingesetzten Softwareentwicklungsbaukastens Apache Beam durchgeführt, der es ermöglicht, entwickelte Anwendungen auf allen unterstützten DSPSs auszuführen. Den Einfluss auf die Performanz des Verwendens von Apache Beam wird dabei ebenfalls in dieser Arbeit untersucht. Weiterhin nutzen wir die veröffentlichte Beispielimplementierung der Queries um drei moderne DSPSs mit ESPBench zu untersuchen: Apache Flink, Apache Spark Streaming und Hazelcast Jet. Der Ergebnisse der Studie verdeutlichen die Funktionsfähigkeit von ESPBench und dessen Toolkit. ESPBench befähigt Performanzcharakteristiken von DSPSs zu quantifizieren und Unterschiede zwischen Systemen aufzuzeigen. Der in dieser Dissertation vorgestellte Benchmark erfüllt alle Anforderungen, um in Stream Processing-Szenarien im Unternehmenskontext eingesetzt zu werden und stellt somit eine Verbesserung der aktuellen Situation dar. KW - stream processing KW - performance KW - benchmarking KW - dsps KW - espbench KW - benchmark KW - Performanz KW - Datenstromverarbeitung KW - Benchmark Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-566000 ER - TY - THES A1 - Mertzen, Daniela T1 - A cross-linguistic investigation of similarity-based interference in sentence comprehension T1 - Eine cross-linguistische Untersuchung ähnlichkeitsbasierter Interferenz in der Satzverarbeitung N2 - The aim of this dissertation was to conduct a larger-scale cross-linguistic empirical investigation of similarity-based interference effects in sentence comprehension. Interference studies can offer valuable insights into the mechanisms that are involved in long-distance dependency completion. Many studies have investigated similarity-based interference effects, showing that syntactic and semantic information are employed during long-distance dependency formation (e.g., Arnett & Wagers, 2017; Cunnings & Sturt, 2018; Van Dyke, 2007, Van Dyke & Lewis, 2003; Van Dyke & McElree, 2011). Nevertheless, there are some important open questions in the interference literature that are critical to our understanding of the constraints involved in dependency resolution. The first research question concerns the relative timing of syntactic and semantic interference in online sentence comprehension. Only few interference studies have investigated this question, and, to date, there is not enough data to draw conclusions with regard to their time course (Van Dyke, 2007; Van Dyke & McElree, 2011). Our first cross-linguistic study explores the relative timing of syntactic and semantic interference in two eye-tracking reading experiments that implement the study design used in Van Dyke (2007). The first experiment tests English sentences. The second, larger-sample experiment investigates the two interference types in German. Overall, the data suggest that syntactic and semantic interference can arise simultaneously during retrieval. The second research question concerns a special case of semantic interference: We investigate whether cue-based retrieval interference can be caused by semantically similar items which are not embedded in a syntactic structure. This second interference study builds on a landmark study by Van Dyke & McElree (2006). The study design used in their study is unique in that it is able to pin down the source of interference as a consequence of cue overload during retrieval, when semantic retrieval cues do not uniquely match the retrieval target. Unlike most other interference studies, this design is able to rule out encoding interference as an alternative explanation. Encoding accounts postulate that it is not cue overload at the retrieval site but the erroneous encoding of similar linguistic items in memory that leads to interference (Lewandowsky et al., 2008; Oberauer & Kliegl, 2006). While Van Dyke & McElree (2006) reported cue-based retrieval interference from sentence-external distractors, the evidence for this effect was weak. A subsequent study did not show interference of this type (Van Dyke et al., 2014). Given these inconclusive findings, further research is necessary to investigate semantic cue-based retrieval interference. The second study in this dissertation provides a larger-scale cross-linguistic investigation of cue-based retrieval interference from sentence-external items. Three larger-sample eye-tracking studies in English, German, and Russian tested cue-based interference in the online processing of filler-gap dependencies. This study further extends the previous research by investigating interference in each language under varying task demands (Logačev & Vasishth, 2016; Swets et al., 2008). Overall, we see some very modest support for proactive cue-based retrieval interference in English. Unexpectedly, this was observed only under a low task demand. In German and Russian, there is some evidence against the interference effect. It is possible that interference is attenuated in languages with richer case marking. In sum, the cross-linguistic experiments on the time course of syntactic and semantic interference from sentence-internal distractors support existing evidence of syntactic and semantic interference during sentence comprehension. Our data further show that both types of interference effects can arise simultaneously. Our cross-linguistic experiments investigating semantic cue-based retrieval interference from sentence-external distractors suggest that this type of interference may arise only in specific linguistic contexts. N2 - Ziel dieser Dissertation war es, eine größer-angelegte, sprachübergreifende, empirische Untersuchung von Interferenzeffekten beim Satzverstehen durchzuführen. Interferenzstudien bieten wertvolle Einblicke in die Mechanismen, die während der Satzverarbeitung, insbesondere bei der Bildung von nicht-lokalen Dependenzen eine Rolle spielen. Studien zu ähnlichkeitsbasierten Interferenzeffekten haben gezeigt, dass syntaktische und semantische Informationen bei der Bildung von nicht-lokalen Dependenzen verwendet werden (z. B. Arnett & Wagers, 2017; Cunnings & Sturt, 2018; Van Dyke, 2007, Van Dyke & Lewis, 2003; Van Dyke & McElree, 2011). Dennoch bleiben in der Interferenzliteratur einige wichtige Fragen unbeantwortet, die für unser Verständnis der Satzverarbeitungsmechanismen von Bedeutung sind. Die erste Forschungsfrage betrifft den zeitlichen Ablauf syntaktischer und semantischer Interferenz während des Satzverstehens. Nur wenige Interferenzstudien haben diese Frage untersucht, jedoch sind aktuell nicht genügend Daten vorhanden, um Schlussfolgerungen bezüglich des zeitlichen Verlaufs zu ziehen (Van Dyke, 2007; Van Dyke & McElree, 2011). Die erste sprachübergreifende Studie in dieser Dissertation untersucht den zeitlichen Ablauf von syntaktischer und semantischer Interferenz mithilfe zweier Eyetracking-Leseexperimente. Diese nutzen das von Van Dyke (2007) implementierte Studiendesign. Das erste Experiment testet englische Sätze. Das zweite Experiment, welches eine größere Stichprobe untersucht, testet Interferenzeffekte im Deutschen. Insgesamt deuten die Daten darauf hin, dass syntaktische und semantische Interferenzeffekte zeitgleich auftreten können. Die zweite Forschungsfrage untersucht einen Spezialfall der semantischen Interferenz: Es wird untersucht, ob cue-abhängige Abrufinterferenz durch Items verursacht werden kann, die nicht in die syntaktische Struktur eingebettet sind. Diese zweite Interferenzstudie nutzt das Studiendesign von Van Dyke & McElree (2006), welches in der Lage ist, die Quelle der Interferenzeffekte als Folge von “cue overload” zu bestimmen, d.h., wenn semantische cues während des Abrufs aus dem Gedächtnis nicht eindeutig mit dem Zielwort übereinstimmen. Im Gegensatz zu anderen Interferenzstudien kann dieses Design Enkodierungsinterferenz als alternative Erklärung ausschließen. Enkodierungsansätze nehmen an, dass nicht ein “cue overload”, sondern eine fehlerhafte Kodierung ähnlicher Items im Gedächtnis Interferenz zur Folge hat (Lewandowsky et al., 2008; Oberauer & Kliegl, 2006). Obwohl die Van Dyke & McElree (2006) Studie angibt, cue-basierte Interferenz zu beobachten, ist die Evidenz für diesen Effekt schwach. Eine Folgestudie findet keine Evidenz für Interferenzeffekte dieser Art (Van Dyke et al., 2014). Die nicht eindeutigen Ergebnisse erfordern weitere Untersuchungen semantischer cue-basierter Interferenz. Die zweite Studie in dieser Dissertation untersucht cue-basierte Interferenzeffekte durch Items, die nicht in die syntaktische Struktur eingebettet sind. Drei Eyetracking-Studien, im Englischen, Deutschen und Russischen, untersuchen cue-basierte Interferenz während der Verarbeitung von “filler-gap” Dependenzen. Diese Studie ergänzt bisherige Studien, indem sie Interferenz in mehreren Sprachen sowie unter unterschiedlich komplexen Aufgabenanforderungen untersucht (Logačev & Vasishth, 2016; Swets et al., 2008). Insgesamt zeigen die Daten nur sehr schwache Evidenz für cue-basierte Interferenz im Englischen, und ausschließlich unter wenig komplexen Aufgabenanforderungen. Im Deutschen und Russischen sprechen die Daten gegen einen Interferenzeffekt, was darauf hinweisen könnte, dass Interferenzeffekte in Sprachen mit reicher Kasusmarkierung nur abgeschwächt vorzufinden sind. Insgesamt zeigen die sprachübergreifenden Experimente zum zeitlichen Verlauf syntaktischer und semantischer Interferenz durch satz-interne Items, dass beide Arten von Interferenzeffekten gleichzeitig auftreten können. Unsere sprachübergreifenden Experimente zur Untersuchung semantischer Interferenzen durch satz-externe Items deuten darauf hin, dass diese Art von Interferenz nur kontextspezifisch auftritt. KW - psycholinguistics KW - sentence processing KW - cue-based retrieval KW - similarity-based interference KW - eye-tracking KW - Psycholinguistik KW - Satzverarbeitung KW - Cue-abhängiger Abruf KW - ähnlichkeitsbasierte Gedächtnisinterferenz KW - Eye-tracking Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-556685 ER - TY - THES A1 - Tattarini, Giulia T1 - A job is good, but is a good job healthier? BT - Longitudinal analyses on the health consequences of unemployment and precarious employment in Europe N2 - What are the consequences of unemployment and precarious employment for individuals' health in Europe? What are the moderating factors that may offset (or increase) the health consequences of labor-market risks? How do the effects of these risks vary across different contexts, which differ in their institutional and cultural settings? Does gender, regarded as a social structure, play a role, and how? To answer these questions is the aim of my cumulative thesis. This study aims to advance our knowledge about the health consequences that unemployment and precariousness cause over the life course. In particular, I investigate how several moderating factors, such as gender, the family, and the broader cultural and institutional context, may offset or increase the impact of employment instability and insecurity on individual health. In my first paper, 'The buffering role of the family in the relationship between job loss and self-perceived health: Longitudinal results from Europe, 2004-2011', I and my co-authors measure the causal effect of job loss on health and the role of the family and welfare states (regimes) as moderating factors. Using EU-SILC longitudinal data (2004-2011), we estimate the probability of experiencing 'bad health' following a transition to unemployment by applying linear probability models and undertake separate analyses for men and women. Firstly, we measure whether changes in the independent variable 'job loss' lead to changes in the dependent variable 'self-rated health' for men and women separately. Then, by adding into the model different interaction terms, we measure the moderating effect of the family, both in terms of emotional and economic support, and how much it varies across different welfare regimes. As an identification strategy, we first implement static fixed-effect panel models, which control for time-varying observables and indirect health selection—i.e., constant unobserved heterogeneity. Secondly, to control for reverse causality and path dependency, we implement dynamic fixed-effect panel models, adding a lagged dependent variable to the model. We explore the role of the family by focusing on close ties within households: we consider the presence of a stable partner and his/her working status as a source of social and economic support. According to previous literature, having a partner should reduce the stress from adverse events, thanks to the symbolic and emotional dimensions that such a relationship entails, regardless of any economic benefits. Our results, however, suggest that benefits linked to the presence of a (female) partner also come from the financial stability that (s)he can provide in terms of a second income. Furthermore, we find partners' employment to be at least as important as the mere presence of the partner in reducing the negative effect of job loss on the individual's health by maintaining the household's standard of living and decreasing economic strain on the family. Our results are in line with previous research, which has highlighted that some people cope better than others with adverse life circumstances, and the support provided by the family is a crucial resource in that regard. We also reported an important interaction between the family and the welfare state in moderating the health consequences of unemployment, showing how the compensation effect of the family varies across welfare regimes. The family plays a decisive role in cushioning the adverse consequences of labor market risks in Southern and Eastern welfare states, characterized by less developed social protection systems and –especially the Southern – high level of familialism. The first paper also found important gender differences concerning job loss, family and welfare effects. Of particular interest is the evidence suggesting that health selection works differently for men and women, playing a more prominent role for women than for men in explaining the relationship between job loss and self-perceived health. The second paper, 'Gender roles and selection mechanisms across contexts: A comparative analysis of the relationship between unemployment, self-perceived health, and gender.' investigates more in-depth the gender differential in health driven by unemployment. Being a highly contested issue in literature, we aim to study whether men are more penalized than women or the other way around and the mechanisms that may explain the gender difference. To do that, we rely on two theoretical arguments: the availability of alternative roles and social selection. The first argument builds on the idea that men and women may compensate for the detrimental health consequences of unemployment through the commitment to 'alternative roles,' which can provide for the resources needed to fulfill people's socially constructed needs. Notably, the availability of alternative options depends on the different positions that men and women have in society. Further, we merge the availability of the 'alternative roles' argument with the health selection argument. We assume that health selection could be contingent on people's social position as defined by gender and, thus, explain the gender differential in the relationship between unemployment and health. Ill people might be less reluctant to fall or remain (i.e., self-select) in unemployment if they have alternative roles. In Western societies, women generally have more alternative roles than men and thus more discretion in their labor market attachment. Therefore, health selection should be stronger for them, explaining why unemployment is less menace for women than for their male counterparts. Finally, relying on the idea of different gender regimes, we extended these arguments to comparison across contexts. For example, in contexts where being a caregiver is assumed to be women's traditional and primary roles and the primary breadwinner role is reserved to men, unemployment is less stigmatized, and taking up alternative roles is more socially accepted for women than for men (Hp.1). Accordingly, social (self)selection should be stronger for women than for men in traditional contexts, where, in the case of ill-health, the separation from work is eased by the availability of alternative roles (Hp.2). By focusing on contexts that are representative of different gender regimes, we implement a multiple-step comparative approach. Firstly, by using EU-SILC longitudinal data (2004-2015), our analysis tests gender roles and selection mechanisms for Sweden and Italy, representing radically different gender regimes, thus providing institutional and cultural variation. Then, we limit institutional heterogeneity by focusing on Germany and comparing East- and West-Germany and older and younger cohorts—for West-Germany (SOEP data 1995-2017). Next, to assess the differential impact of unemployment for men and women, we compared (unemployed and employed) men with (unemployed and employed) women. To do so, we calculate predicted probabilities and average marginal effect from two distinct random-effects probit models. Our first step is estimating random-effects models that assess the association between unemployment and self-perceived health, controlling for observable characteristics. In the second step, our fully adjusted model controls for both direct and indirect selection. We do this using dynamic correlated random-effects (CRE) models. Further, based on the fully adjusted model, we test our hypotheses on alternative roles (Hp.1) by comparing several contexts – models are estimated separately for each context. For this hypothesis, we pool men and women and include an interaction term between unemployment and gender, which has the advantage to allow for directly testing whether gender differences in the effect of unemployment exist and are statistically significant. Finally, we test the role of selection mechanisms (Hp.2), using the KHB method to compare coefficients across nested nonlinear models. Specifically, we test the role of selection for the relationship between unemployment and health by comparing the partially-adjusted and fully-adjusted models. To allow selection mechanisms to operate differently between genders, we estimate separate models for men and women. We found support to our first hypotheses—the context where people are embedded structures the relationship between unemployment, health, and gender. We found no gendered effect of unemployment on health in the egalitarian context of Sweden. Conversely, in the traditional context of Italy, we observed substantive and statistically significant gender differences in the effect of unemployment on bad health, with women suffering less than men. We found the same pattern for comparing East and West Germany and younger and older cohorts in West Germany. On the contrary, our results did not support our theoretical argument on social selection. We found that in Sweden, women are more selected out of employment than men. In contrast, in Italy, health selection does not seem to be the primary mechanism behind the gender differential—Italian men and women seem to be selected out of employment to the same extent. Namely, we do not find any evidence that health selection is stronger for women in more traditional countries (Hp2), despite the fact that the institutional and the cultural context would offer them a more comprehensive range of 'alternative roles' relative to men. Moreover, our second hypothesis is also rejected in the second and third comparisons, where the cross-country heterogeneity is reduced to maximize cultural differences within the same institutional context. Further research that addresses selection into inactivity is needed to evaluate the interplay between selection and social roles across gender regimes. While the health consequences of unemployment have been on the research agenda for a pretty long time, the interest in precarious employment—defined as the linking of the vulnerable worker to work that is characterized by uncertainty and insecurity concerning pay, the stability of the work arrangement, limited access to social benefits, and statutory protections—has emerged only later. Since the 80s, scholars from different disciplines have raised concerns about the social consequences of de-standardization of employment relationships. However, while work has become undoubtedly more precarious, very little is known about its causal effect on individual health and the role of gender as a moderator. These questions are at the core of my third paper : 'Bad job, bad health? A longitudinal analysis of the interaction between precariousness, gender and self-perceived health in Germany'. Herein, I investigate the multidimensional nature of precarious employment and its causal effect on health, particularly focusing on gender differences. With this paper, I aim at overcoming three major shortcomings of earlier studies: The first one regards the cross-sectional nature of data that prevents the authors from ruling out unobserved heterogeneity as a mechanism for the association between precarious employment and health. Indeed, several unmeasured individual characteristics—such as cognitive abilities—may confound the relationship between precarious work and health, leading to biased results. Secondly, only a few studies have directly addressed the role of gender in shaping the relationship. Moreover, available results on the gender differential are mixed and inconsistent: some found precarious employment being more detrimental for women's health, while others found no gender differences or stronger negative association for men. Finally, previous attempts to an empirical translation of the employment precariousness (EP) concept have not always been coherent with their theoretical framework. EP is usually assumed to be a multidimensional and continuous phenomenon; it is characterized by different dimensions of insecurity that may overlap in the same job and lead to different "degrees of precariousness." However, researchers have predominantly focused on one-dimensional indicators—e.g., temporary employment, subjective job insecurity—to measure EP and study the association with health. Besides the fact that this approach partially grasps the phenomenon's complexity, the major problem is the inconsistency of evidence that it has produced. Indeed, this line of inquiry generally reveals an ambiguous picture, with some studies finding substantial adverse effects of temporary over permanent employment, while others report only minor differences. To measure the (causal) effect of precarious work on self-rated health and its variation by gender, I focus on Germany and use four waves from SOEP data (2003, 2007, 2011, and 2015). Germany is a suitable context for my study. Indeed, since the 1980s, the labor market and welfare system have been restructured in many ways to increase the German economy's competitiveness in the global market. As a result, the (standard) employment relationship has been de-standardized: non-standard and atypical employment arrangements—i.e., part-time work, fixed-term contracts, mini-jobs, and work agencies—have increased over time while wages have lowered, even among workers with standard work. In addition, the power of unions has also fallen over the last three decades, leaving a large share of workers without collective protection. Because of this process of de-standardization, the link between wage employment and strong social rights has eroded, making workers more powerless and more vulnerable to labor market risks than in the past. EP refers to this uneven distribution of power in the employment relationship, which can be detrimental to workers' health. Indeed, by affecting individuals' access to power and other resources, EP puts precarious workers at risk of experiencing health shocks and influences their ability to gain and accumulate health advantages (Hp.1). Further, the focus on Germany allows me to investigate my second research question on the gender differential. Germany is usually regarded as a traditionalist gender regime: a context characterized by a configuration of roles. Here, being a caregiver is assumed to be women's primary role, whereas the primary breadwinner role is reserved for men. Although many signs of progress have been made over the last decades towards a greater equalization of opportunities and more egalitarianism, the breadwinner model has barely changed towards a modified version. Thus, women usually take on the double role of workers (the so-called secondary earner) and caregivers, and men still devote most of their time to paid work activities. Moreover, the overall upward trend towards more egalitarian gender ideologies has leveled off over the last decades, moving notably towards more traditional gender ideologies. In this setting, two alternative hypotheses are possible. Firstly, I assume that the negative relationship between EP and health is stronger for women than for men. This is because women are systematically more disadvantaged than men in the public and private spheres of life, having less access to formal and informal sources of power. These gender-related power asymmetries may interact with EP-related power asymmetries resulting in a stronger effect of EP on women's health than on men's health (Hp.2). An alternative way of looking at the gender differential is to consider the interaction that precariousness might have with men's and women's gender identities. According to this view, the negative relationship between EP and health is weaker for women than for men (Hp.2a). In a society with a gendered division of labor and a strong link between masculine identities and stable and well-rewarded job—i.e., a job that confers the role of primary family provider—a male worker with precarious employment might violate the traditional male gender role. Men in precarious jobs may perceive themselves (and by others) as possessing a socially undesirable characteristic, which conflicts with the stereotypical idea of themselves as the male breadwinner. Engaging in behaviors that contradict stereotypical gender identity may decrease self-esteem and foster feelings of inferiority, helplessness, and jealousy, leading to poor health. I develop a new indicator of EP that empirically translates a definition of EP as a multidimensional and continuous phenomenon. I assume that EP is a latent construct composed of seven dimensions of insecurity chosen according to the theory and previous empirical research: Income insecurity, social insecurity, legal insecurity, employment insecurity, working-time insecurity, representation insecurity, worker's vulnerability. The seven dimensions are proxied by eight indicators available in the four waves of the SOEP dataset. The EP composite indicator is obtained by performing a multiple correspondence analysis (MCA) on the eight indicators. This approach aims to construct a summary scale in which all dimensions contribute jointly to the measured experience of precariousness and its health impact. Further, the relationship between EP and 'general self-perceived health' is estimated by applying ordered probit random-effects estimators and calculating average marginal effect (further AME). Then, to control for unobserved heterogeneity, I implement correlated random-effects models that add to the model the within-individual means of the time-varying independent variables. To test the significance of the gender differential, I add an interaction term between EP and gender in the fully adjusted model in the pooled sample. My correlated random-effects models showed EP's negative and substantial 'effect' on self-perceived health for both men and women. Although nonsignificant, the evidence seems in line with previous cross-sectional literature. It supports the hypothesis that employment precariousness could be detrimental to workers' health. Further, my results showed the crucial role of unobserved heterogeneity in shaping the health consequences of precarious employment. This is particularly important as evidence accumulates, yet it is still mostly descriptive. Moreover, my results revealed a substantial difference among men and women in the relationship between EP and health: when EP increases, the risk of experiencing poor health increases much more for men than for women. This evidence falsifies previous theory according to whom the gender differential is contingent on the structurally disadvantaged position of women in western societies. In contrast, they seem to confirm the idea that men in precarious work could experience role conflict to a larger extent than women, as their self-standard is supposed to be the stereotypical breadwinner worker with a good and well-rewarded job. Finally, results from the multiple correspondence analysis contribute to the methodological debate on precariousness, showing that a multidimensional and continuous indicator can express a latent variable of EP. All in all, complementarities are revealed in the results of unemployment and employment precariousness, which have two implications: Policy-makers need to be aware that the total costs of unemployment and precariousness go far beyond the economic and material realm penetrating other fundamental life domains such as individual health. Moreover, they need to balance the trade-off between protecting adequately unemployed people and fostering high-quality employment in reaction to the highlighted market pressures. In this sense, the further development of a (universalistic) welfare state certainly helps mitigate the adverse health effects of unemployment and, therefore, the future costs of both individuals' health and welfare spending. In addition, the presence of a working partner is crucial for reducing the health consequences of employment instability. Therefore, policies aiming to increase female labor market participation should be promoted, especially in those contexts where the welfare state is less developed. Moreover, my results support the significance of taking account of a gender perspective in health research. The findings of the three articles show that job loss, unemployment, and precarious employment, in general, have adverse effects on men's health but less or absent consequences for women's health. Indeed, this suggests the importance of labor and health policies that consider and further distinguish the specific needs of the male and female labor force in Europe. Nevertheless, a further implication emerges: the health consequences of employment instability and de-standardization need to be investigated in light of the gender arrangements and the transforming gender relationships in specific cultural and institutional contexts. My results indeed seem to suggest that women's health advantage may be a transitory phenomenon, contingent on the predominant gendered institutional and cultural context. As the structural difference between men's and women's position in society is eroded, egalitarianism becomes the dominant normative status, so will probably be the gender difference in the health consequences of job loss and precariousness. Therefore, while gender equality in opportunities and roles is a desirable aspect for contemporary societies and a political goal that cannot be postponed further, this thesis raises a further and maybe more crucial question: What kind of equality should be pursued to provide men and women with both good life quality and equal chances in the public and private spheres? In this sense, I believe that social and labor policies aiming to reduce gender inequality in society should focus on improving women's integration into the labor market, implementing policies targeting men, and facilitating their involvement in the private sphere of life. Equal redistribution of social roles could activate a crucial transformation of gender roles and the cultural models that sustain and still legitimate gender inequality in Western societies. KW - unemployment KW - employment precariousness KW - self-rated health KW - gender KW - family KW - welfare and gender regimes Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-536723 ER - TY - THES A1 - Gerling, Marten Tobias T1 - A microfluidic system for high-precision image-based live cell sorting using dielectrophoretic forces T1 - Ein mikrofluidisches System zur hochpräzisen und bildgestützten Sortierung lebender Zellen mittels dielektrophoretischer Kräfte N2 - An important goal in biotechnology and (bio-) medical research is the isolation of single cells from a heterogeneous cell population. These specialised cells are of great interest for bioproduction, diagnostics, drug development, (cancer) therapy and research. To tackle emerging questions, an ever finer differentiation between target cells and non-target cells is required. This precise differentiation is a challenge for a growing number of available methods. Since the physiological properties of the cells are closely linked to their morphology, it is beneficial to include their appearance in the sorting decision. For established methods, this represents a non addressable parameter, requiring new methods for the identification and isolation of target cells. Consequently, a variety of new flow-based methods have been developed and presented in recent years utilising 2D imaging data to identify target cells within a sample. As these methods aim for high throughput, the devices developed typically require highly complex fluid handling techniques, making them expensive while offering limited image quality. In this work, a new continuous flow system for image-based cell sorting was developed that uses dielectrophoresis to precisely handle cells in a microchannel. Dielectrophoretic forces are exerted by inhomogeneous alternating electric fields on polarisable particles (here: cells). In the present system, the electric fields can be switched on and off precisely and quickly by a signal generator. In addition to the resulting simple and effective cell handling, the system is characterised by the outstanding quality of the image data generated and its compatibility with standard microscopes. These aspects result in low complexity, making it both affordable and user-friendly. With the developed cell sorting system, cells could be sorted reliably and efficiently according to their cytosolic staining as well as morphological properties at different optical magnifications. The achieved purity of the target cell population was up to 95% and about 85% of the sorted cells could be recovered from the system. Good agreement was achieved between the results obtained and theoretical considerations. The achieved throughput of the system was up to 12,000 cells per hour. Cell viability studies indicated a high biocompatibility of the system. The results presented demonstrate the potential of image-based cell sorting using dielectrophoresis. The outstanding image quality and highly precise yet gentle handling of the cells set the system apart from other technologies. This results in enormous potential for processing valuable and sensitive cell samples. N2 - Ein wichtiges Ziel in der Biotechnologie und (bio-) medizinischen Forschung ist die Isolation von Einzelzellen aus einer heterogenen Zellpopulation. Aufgrund ihrer besonderen Eigenschaften sind diese Zellen für die Bioproduktion, Diagnostik, Arzneimittelentwicklung, (Krebs-) Therapie und Forschung von großem Interesse. Um neue Fragestellungen angehen zu können, ist eine immer feinere Differenzierung zwischen Zielzellen und Nicht-Zielzellen erforderlich. Diese präzise Differenzierung stellt eine Herausforderung für eine wachsende Zahl verfügbarer Methoden dar. Da die physiologischen Eigenschaften der Zellen eng mit ihrer Morphologie verknüpft sind, ist es sinnvoll ihr Erscheinungsbild mit in die Sortierentscheidung einzubeziehen. Für etablierte Methoden stellt dies jedoch einen nicht adressierbaren Parameter dar, weshalb neue Methoden zur Identifikation und Isolation der Zielzellen benötigt werden. Folglich wurde in den letzten Jahren eine Vielzahl neuer durchflussbasierter Methoden entwickelt und vorgestellt, die 2D-Bilddaten zur Identifikation der Zielzellen innerhalb einer Probe heranziehen. Da diese Methoden auf hohe Durchsätze abzielen, erfordern die entwickelten Geräte in der Regel hochkomplexe Techniken zur Handhabung der Flüssigkeiten, was sie teuer macht und gleichzeitig zu einer begrenzten Bildqualität führt. In dieser Arbeit wurde ein neues durchflussbasiertes System zur bildbasierten Zellsortierung entwickelt, das Dielektrophorese zur präzisen Handhabung der Zellen in einem Mikrokanal verwendet. Dielektrophoretische Kräfte werden von inhomogenen elektrischen Wechselfeldern auf polarisierbare Partikel (hier: Zellen) ausgeübt. Bei dem vorliegenden System können die elektrischen Felder durch einen Signalgenerator präzise und schnell ein- und ausgeschaltet werden. Neben der daraus resultierenden einfachen und effektiven Handhabung der Zellen zeichnet sich das System durch die hervorragende Qualität der erzeugten Bilddaten und die Kompatibilität mit Standardmikroskopen aus. Diese Aspekte führen zu einer geringen Komplexität, die es sowohl erschwinglich als auch benutzerfreundlich macht. Mit dem entwickelten System zur Zellsortierung konnten Zellen sowohl auf Basis einer zytosolischen Färbung als auch auf Basis morphologischer Eigenschaften bei verschiedenen optischen Vergrößerungen zuverlässig und effizient sortiert werden. Die erreichte Reinheit der Zielzellpopulation betrug bis zu 95% wobei etwa 85% der sortierten Zellen aus dem System zurückgewonnen werden konnten. Dabei wurde eine gute Übereinstimmung der ermittelten Ergebnisse mit theoretischen Überlegungen erreicht. Der erreichte Durchsatz des Systems betrug bis zu 12.000 Zellen pro Stunde. Untersuchungen der Zellvitalität deuteten darauf hin, dass das System eine hohe Biokompatibilität aufweist. Die vorgestellten Ergebnisse demonstrieren das Potenzial der bildbasierten Zellsortierung mittels Dielektrophorese. Die herausragende Bildqualität und hochpräzise aber dennoch zellschonende Handhabung der Zellen grenzen das System von anderen Technologien ab. Daraus ergibt sich ein enormes Potenzial für die Verarbeitung wertvoller und sensibler Zellproben. KW - microfluidics KW - cell sorting KW - dielectrophoresis KW - Zellsortierung KW - Dielektrophorese KW - Mikrofluidik Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-587421 ER - TY - THES A1 - Vu, Nils Leif T1 - A task-based parallel elliptic solver for numerical relativity with discontinuous Galerkin methods N2 - Elliptic partial differential equations are ubiquitous in physics. In numerical relativity---the study of computational solutions to the Einstein field equations of general relativity---elliptic equations govern the initial data that seed every simulation of merging black holes and neutron stars. In the quest to produce detailed numerical simulations of these most cataclysmic astrophysical events in our Universe, numerical relativists resort to the vast computing power offered by current and future supercomputers. To leverage these computational resources, numerical codes for the time evolution of general-relativistic initial value problems are being developed with a renewed focus on parallelization and computational efficiency. Their capability to solve elliptic problems for accurate initial data must keep pace with the increasing detail of the simulations, but elliptic problems are traditionally hard to parallelize effectively. In this thesis, I develop new numerical methods to solve elliptic partial differential equations on computing clusters, with a focus on initial data for orbiting black holes and neutron stars. I develop a discontinuous Galerkin scheme for a wide range of elliptic equations, and a stack of task-based parallel algorithms for their iterative solution. The resulting multigrid-Schwarz preconditioned Newton-Krylov elliptic solver proves capable of parallelizing over 200 million degrees of freedom to at least a few thousand cores, and already solves initial data for a black hole binary about ten times faster than the numerical relativity code SpEC. I also demonstrate the applicability of the new elliptic solver across physical disciplines, simulating the thermal noise in thin mirror coatings of interferometric gravitational-wave detectors to unprecedented accuracy. The elliptic solver is implemented in the new open-source SpECTRE numerical relativity code, and set up to support simulations of astrophysical scenarios for the emerging era of gravitational-wave and multimessenger astronomy. N2 - Elliptische partielle Differentialgleichungen sind in der Physik allgegenwärtig. Das elektrische Feld einer Ladung, die Gravitation der Erde, die Statik einer Brücke, oder die Temperaturverteilung auf einer heißen Herdplatte folgen trotz verschiedenster zugrundeliegender Physik elliptischen Gleichungen ähnlicher Struktur, denn es sind statische, also zeitunabhängige Effekte. Elliptische Gleichungen beschreiben auch astrophysikalische Szenarien von kataklysmischen Ausmaßen, die jegliche Gegebenheiten auf der Erde weit überschreiten. So werden Schwarze Löcher und Neutronensterne -- zwei mögliche Endstadien von massereichen Sternen -- ebenfalls von elliptischen Gleichungen beschrieben. In diesem Fall sind es Einstein's Feldgleichungen von Raum, Zeit, Gravitation und Materie. Da Schwarze Löcher und Neutronensterne mehr Masse als unsere Sonne auf die Größe einer Stadt wie Potsdam komprimieren übernimmt die Gravitation, und damit Einstein's allgemeine Relativitätstheorie, die Kontrolle. Es ist die Aufgabe der numerischen Relativität, Szenarien wie die Kollision solcher gewaltigen Objekte mithilfe von Supercomputern zu simulieren und damit die Gravitationswellensignale vorherzusagen, die von Detektoren auf der Erde gemessen werden können. Jede dieser Simulationen beginnt mit Anfangsdaten, die elliptische Gleichungen erfüllen müssen. In dieser Dissertation entwickle ich neue numerische Methoden um elliptische partielle Differentialgleichungen auf Supercomputern zu lösen, mit besonderem Augenmerk auf Anfangsdaten für Simulationen von Schwarzen Löchern und Neutronensternen. Ich entwickle dafür eine sogenannte discontinuous Galerkin Methode um elliptische Gleichungen auf Computern zu repräsentieren, sowie eine Reihe von Algorithmen um diese Gleichungen anschließend schrittweise numerisch zu lösen bis sie die notwendige Präzision erfüllen. Die Besonderheit dieser Algorithmen liegt in ihrer Eigenschaft, in viele Teilprobleme zerlegt auf einer großen Zahl von Rechenkernen parallel arbeiten zu können. Dieses task-based parallelism ermöglicht die effektive Verwendung von Supercomputern. Ich demonstriere die Fähigkeit meiner Algorithmen, Berechnungen von über 200 Millionen Unbekannten mit hoher Effizienz auf mindestens einige Tausend Rechenkerne verteilen zu können, und Anfangsdaten zweier sich umkreisender Schwarzer Löcher bereits etwa zehnmal schneller zu lösen als der langjährig verwendete Computercode SpEC. Außerdem zeige ich, dass mein neuer Code auch außerhalb der Relativitätstheorie anwendbar ist. Dazu simuliere ich thermisches Rauschen in den Beschichtungen von Spiegeln, das ebenfalls von elliptischen Gleichungen beschrieben wird. Solche Spiegel sind Objekt großen Forschungsinteresses, da sie ein zentrales Element von Gravitationswellendetektoren darstellen. Mein Code zur numerischen Lösung elliptischer Gleichungen ist Teil des kollaborativen und quelloffenen SpECTRE Forschungsprojekts zur Simulation astrophysikalischer Szenarien für die aufstrebende Ära der Gravitationswellen- und Multimessenger-Astronomie. KW - numerical relativity KW - task-based parallelism KW - discontinuous Galerkin methods KW - elliptic partial differential equations KW - black holes KW - initial data KW - high-performance computing KW - iterative methods for sparse linear systems KW - gravitational waves KW - thermal noise in mirror coatings KW - numerische Relativität KW - elliptische partielle Differentialgleichungen KW - schwarze Löcher KW - Anfangsdaten KW - Hochleistungscomputer KW - iterative Methoden zur Lösung linearer Systeme KW - Gravitationswellen KW - thermisches Rauschen in Spiegelbeschichtungen Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-562265 ER - TY - THES A1 - Müller, Daniela T1 - Abrupt climate changes and extreme events in two different varved lake sediment records T1 - Abrupte Klimaveränderungen und Extremevents in Sedimentprofilen zweier verschiedener warvierter Seen N2 - Different lake systems might reflect different climate elements of climate changes, while the responses of lake systems are also divers, and are not completely understood so far. Therefore, a comparison of lakes in different climate zones, during the high-amplitude and abrupt climate fluctuations of the Last Glacial to Holocene transition provides an exceptional opportunity to investigate distinct natural lake system responses to different abrupt climate changes. The aim of this doctoral thesis was to reconstruct climatic and environmental fluctuations down to (sub-) annual resolution from two different lake systems during the Last Glacial-Interglacial transition (~17 and 11 ka). Lake Gościąż, situated in the temperate central Poland, developed in the Allerød after recession of the Last Glacial ice sheets. The Dead Sea is located in the Levant (eastern Mediterranean) within a steep gradient from sub-humid to hyper-arid climate, and formed in the mid-Miocene. Despite their differences in sedimentation processes, both lakes form annual laminations (varves), which are crucial for studies of abrupt climate fluctuations. This doctoral thesis was carried out within the DFG project PALEX-II (Paleohydrology and Extreme Floods from the Dead Sea ICDP Core) that investigates extreme hydro-meteorological events in the ICDP core in relation to climate changes, and ICLEA (Virtual Institute of Integrated Climate and Landscape Evolution Analyses) that intends to better the understanding of climate dynamics and landscape evolutions in north-central Europe since the Last Glacial. Further, it contributes to the Helmholtz Climate Initiative REKLIM (Regional Climate Change and Humans) Research Theme 3 “Extreme events across temporal and spatial scales” that investigates extreme events using climate data, paleo-records and model-based simulations. The three main aims were to (1) establish robust chronologies of the lakes, (2) investigate how major and abrupt climate changes affect the lake systems, and (3) to compare the responses of the two varved lakes to these hemispheric-scale climate changes. Robust chronologies are a prerequisite for high-resolved climate and environmental reconstructions, as well as for archive comparisons. Thus, addressing the first aim, the novel chronology of Lake Gościąż was established by microscopic varve counting and Bayesian age-depth modelling in Bacon for a non-varved section, and was corroborated by independent age constrains from 137Cs activity concentration measurements, AMS radiocarbon dating and pollen analysis. The varve chronology reaches from the late Allerød until AD 2015, revealing more Holocene varves than a previous study of Lake Gościąż suggested. Varve formation throughout the complete Younger Dryas (YD) even allowed the identification of annually- to decadal-resolved leads and lags in proxy responses at the YD transitions. The lateglacial chronology of the Dead Sea (DS) was thus far mainly based on radiocarbon and U/Th-dating. In the unique ICDP core from the deep lake centre, continuous search for cryptotephra has been carried out in lateglacial sediments between two prominent gypsum deposits – the Upper and Additional Gypsum Units (UGU and AGU, respectively). Two cryptotephras were identified with glass analyses that correlate with tephra deposits from the Süphan and Nemrut volcanoes indicating that the AGU is ~1000 years younger than previously assumed, shifting it into the YD, and the underlying varved interval into the Bølling/Allerød, contradicting previous assumptions. Using microfacies analyses, stable isotopes and temperature reconstructions, the second aim was achieved at Lake Gościąż. The YD lake system was dynamic, characterized by higher aquatic bioproductivity, more re-suspended material and less anoxia than during the Allerød and Early Holocene, mainly influenced by stronger water circulation and catchment erosion due to stronger westerly winds and less lake sheltering. Cooling at the YD onset was ~100 years longer than the final warming, while environmental proxies lagged the onset of cooling by ~90 years, but occurred contemporaneously during the termination of the YD. Chironomid-based temperature reconstructions support recent studies indicating mild YD summer temperatures. Such a comparison of annually-resolved proxy responses to both abrupt YD transitions is rare, because most European lake archives do not preserve varves during the YD. To accomplish the second aim at the DS, microfacies analyses were performed between the UGU (~17 ka) and Holocene onset (~11 ka) in shallow- (Masada) and deep-water (ICDP core) environments. This time interval is marked by a huge but fluctuating lake level drop and therefore the complete transition into the Holocene is only recorded in the deep-basin ICDP core. In this thesis, this transition was investigated for the first time continuously and in detail. The final two pronounced lake level drops recorded by deposition of the UGU and AGU, were interrupted by one millennium of relative depositional stability and a positive water budget as recorded by aragonite varve deposition interrupted by only a few event layers. Further, intercalation of aragonite varves between the gypsum beds of the UGU and AGU shows that these generally dry intervals were also marked by decadal- to centennial-long rises in lake level. While continuous aragonite varves indicate decadal-long stable phases, the occurrence of thicker and more frequent event layers suggests general more instability during the gypsum units. These results suggest a pattern of complex and variable hydroclimate at different time scales during the Lateglacial at the DS. The third aim was accomplished based on the individual studies above that jointly provide an integrated picture of different lake responses to different climate elements of hemispheric-scale abrupt climate changes during the Last Glacial-Interglacial transition. In general, climatically-driven facies changes are more dramatic in the DS than at Lake Gościąż. Further, Lake Gościąż is characterized by continuous varve formation nearly throughout the complete profile, whereas the DS record is widely characterized by extreme event layers, hampering the establishment of a continuous varve chronology. The lateglacial sedimentation in Lake Gościąż is mainly influenced by westerly winds and minor by changes in catchment vegetation, whereas the DS is primarily influenced by changes in winter precipitation, which are caused by temperature variations in the Mediterranean. Interestingly, sedimentation in both archives is more stable during the Bølling/Allerød and more dynamic during the YD, even when sedimentation processes are different. In summary, this doctoral thesis presents seasonally-resolved records from two lake archives during the Lateglacial (ca 17-11 ka) to investigate the impact of abrupt climate changes in different lake systems. New age constrains from the identification of volcanic glass shards in the lateglacial sediments of the DS allowed the first lithology-based interpretation of the YD in the DS record and its comparison to Lake Gościąż. This highlights the importance of the construction of a robust chronology, and provides a first step for synchronization of the DS with other eastern Mediterranean archives. Further, climate reconstructions from the lake sediments showed variability on different time scales in the different archives, i.e. decadal- to millennial fluctuations in the lateglacial DS, and even annual variations and sub-decadal leads and lags in proxy responses during the rapid YD transitions in Lake Gościąż. This showed the importance of a comparison of different lake archives to better understand the regional and local impacts of hemispheric-scale climate variability. An unprecedented example is demonstrated here of how different lake systems show different lake responses and also react to different climate elements of abrupt climate changes. This further highlights the importance of the understanding of the respective lake system for climate reconstructions. N2 - Verschiedene Seesysteme können unterschiedliche Klimaelemente während Klimaveränderungen wiederspiegeln und auch diverse Seesystemreaktionen aufweisen, wobei letztere bislang noch nicht vollständig verstanden sind. Ein Vergleich von Seesystemen in verschiedenen Klimazonen während der hoch-amplituden und abrupten Klimaveränderung innerhalb des Übergangs vom Letzten Glazial zum Holozän, ermöglicht die Untersuchung deutlicher natürlicher Seesystemreaktionen in Bezug zu abrupten Klimaänderungen. Das Ziel dieser Doktorarbeit war die Rekonstruktion von Klima- und Umweltschwankungen von zwei verschiedenen Seesystemen während des Letzten Glazial-Interglazial-Übergangs (~17.000-11.000 BP) bis hinunter zu saisonaler Auflösung. Der Gościąż See liegt in der gemäßigten Klimazone in Zentralpolen und entwickelte sich im Allerød nach dem Rückgang der Eisschilde des letzten Glazials. Das Tote Meer liegt in der Levante (östlicher Mittelmeerraum) innerhalb eines steilen Gradienten von subhumidem zu hyperaridem Klima und entstand im mittleren Miozän. Trotz ihrer unterschiedlichen Sedimentationsprozesse bilden beide Seen jährliche Laminierungen (Warven) aus. Dies ist essentiell für Studien abrupter Klimaveränderungen. Diese Doktorarbeit wurde innerhalb des DFG-Projektes PALEX-II (Paläohydrologie und Sturzfluten vom ICDP-Kern des Toten Meeres) und ICELA (Virtuelles Institut zur Integrierten Klima- und Landschaftsentwicklungsanalyse) durchgeführt. PALEX-II untersucht hydrometeorologische Extremereignisse im ICDP-Kern in Bezug zu Klimaveränderungen, während ICLEA beabsichtig das Verständnis von Klimadynamiken und Landschaftsevolution in Nord- und Zentraleuropa seit dem letzten Glazial zu verbessern. Zudem, trägt diese Doktorarbeit auch zum Forschungsthema 3 „Extremevents auf unterschiedlichen zeitlichen und räumlichen Skalen“ der Helmholtz-Klimainitiative REKLIM (Regionale Klimaänderungen und Mensch) bei, das basierend auf Klimadaten, Paläoarchiven und modelbasierten Simulationen Extremevents untersucht. Robuste Chronologien sind Voraussetzung für hochaufgelöste Klima- und Umweltstudien, sowie für den Vergleich von Archiven. Um das erste Ziel zu erreichen, wurde für den Gościąż See mithilfe von mikroskopischer Warvenzählung und einer bayesschen Alters-Tiefen-Modellierung eine neue Chronologie erstellt. Diese wurde durch unabhängige Altersinformationen von 137Cs Konzentrationsmessungen, AMS Radiokarbondatierung und Pollenanalyse bestätigt. Die Warvenchronologie beginnt im späten Allerød und endet AD 2015. Sie offenbart mehr Warven im Holozän als in einer früheren Studie vom Gościąż See gezeigt wurde. Warvenbildung durch die gesamte Jüngere Dryaszeit (JD) hindurch ermöglicht sogar die Identifizierung von jährlich bis dekadisch aufgelösten Abfolgen in Proxyreaktion während der Übergangszonen der JD. Die spätglaziale Chronologie des Toten Meeres basierte bisher auf Radiokarbon- und U/Th-Datierungen. In den spätglazialen Sedimenten des einzigartigen ICDP-Kern vom tiefen Seezentrum wurde zwischen zwei markanten Gipseinheiten – den Oberen und Zusätzlichen Gipseinheiten (UGU bzw. AGU) – kontinuierlich nach Kryptotephra gesucht. Gläser zweier Kryptotephren korrelieren mit Aschenablagerungen der Süphan und Nemrut Vulkane. Dies deutet darauf hin, dass die AGU ~1000 Jahre jünger ist als bisher angenommen, was sie komplett in die JD verlagert und das darunterliegende warvierte Intervall in das Bølling/Allerød. Diese Ergebnisse widersprechen bisherigen Annahmen. Unter Verwendung von Mikrofaziesanalysen, stabiler Isotope und Temperaturrekonstruktionen, wurde das zweite Ziel am Gościąż See erreicht. Das Seesystem war während der JD dynamisch und durch höhere aquatische Bioproduktivität, Resuspension und geringere anoxische Bedingungen als das Allerød und frühe Holozän gekennzeichnet. Dies wurde hauptsächlich durch eine verstärkte Wasserzirkulation und Erosion im Einzugsgebiet hervorgerufen, die wiederum durch stärkere Westwinde und geringeren Schutz vor Wind im Einzugsgebiet verursacht wurden. Die Abkühlung am Beginn der JD war etwa 100 Jahre länger als die finale Erwärmung an ihrem Ende, während die Umweltproxies ca. 90 Jahre nach Beginn der Abkühlung, aber gleichzeitig mit der Erwärmung auftraten. Auf Chironomiden basierende Temperatur-rekonstruktionen unterstützen neueste Studien, die milde Sommertemperaturen während der JD anzeigen. Da die meisten europäischen Seearchive keine Warven während der JD erhalten, ist ein solcher Vergleich von jährlich aufgelösten Proxyreaktionen während beiden JD Übergangszonen sehr selten. Um das zweite Ziel auch am Toten Meer zu realisieren, wurden Mikrofaziesanalysen zwischen der UGU (~17.000 BP) und dem Beginn des Holozäns (~11.000 BP) in Sedimenten aus dem Flachwasserbereich (Masada) und aus dem tiefen Becken (ICDP-Kern) durchgeführt. In diesem Intervall sinkt der Seespiegel gewaltig ab, wobei er von Schwankungen betroffen ist. Daher ist der komplette Übergang in das Holozän nur im ICDP-Kern enthalten, der im tiefen Becken gezogen wurde. In dieser Doktorarbeit wurde dieser Übergang zum ersten Mal kontinuierlich und im Detail untersucht. Während der beiden finalen Seespiegelabfälle wurden die UGU und AGU abgelagert. Zwischen den beiden Gipseinheiten zeugen jedoch Aragonitwarven und nur wenige Extremevents von sedimentärer Stabilität und einem positiven Wasserbudget für beinahe ein Jahrtausend. Selbst innerhalb der UGU und AGU deutet die Ablagerung von Aragonitwarven zwischen Gipslagen auf Dekaden bis Jahrhunderte andauernde Anstiege im Seespiegel hin, was zeigt, dass UGU und AGU nicht kontinuierlich von Trockenheit gekennzeichnet waren. Die kontinuierliche Bildung von Aragonitwarven zeigt hier stabile Phasen über Dekaden, wohingegen mächtigere und häufigere Extremevents generell auf eine erhöhte Instabilität während der Gipseinheiten hindeuten. Diese Ergebnisse zeigen, dass ein komplexes und variables Hydroklima auf unterschiedlichen Zeitskalen während des Spätglazials am Toten Meer operierte. Das dritte Ziel wurde basierend auf den individuellen Studien erreicht, die zusammen ein ganzheitliches Bild zu verschiedenen Seesystemreaktionen liefern, die während des Übergangs vom letzten Glazial zum Holozän durch diverse Klimaelemente während abrupter Klimaveränderungen mit hemisphärischen Ausmaßen beeinflusst sind. Grundsätzlich sind die durch Klimaänderungen ausgelösten Faziesänderungen ausgeprägter am Toten Meer als im Gościąż See. Zudem ist der Gościąż See beinahe durchgängig warviert, während die Sedimente des Toten Meeres weithin durch Ablagerungen von Extremevents geprägt sind, welche die Konstruktion einer kontinuierlichen Warvenchronologie verhindern. Die spätglaziale Sedimentation im Gościąż See ist hauptsächlich durch Westwinde beeinflusst und untergeordnet auch durch Vegetationsänderungen im Einzugsgebiet. Im Gegensatz dazu ist die spätglaziale Sedimentation im Toten Meer überwiegend von Schwankungen im Niederschlag während des Winters beeinflusst. Diese wiederum werden durch Temperaturschwankungen im Mittelmeer verursacht. Obwohl die Sedimentationsprozesse so verschieden sind, ist die Sedimentation interessanterweise in beiden Archiven stabiler im Bølling/Allerød und dynamischer in der JD. Kurz zusammengefasst, präsentiert diese Doktorarbeit saisonal-aufgelöste Sedimentprofile zweier Seearchive während des Spätglazials (ca. 17.000-11.000 BP), um die Auswirkungen abrupter Klimaveränderungen in verschiedenen Seesystemen zu untersuchen. Neue Altersinformationen anhand der Identifizierung von vulkanischen Aschen in den spätglazialen Sedimenten des Toten Meeres erlaubten die erste Lithologie-basierte Interpretation der JD im Sedimentprofil des Toten Meeres und den Vergleich mit dem Gościąż See. Dies hebt die Bedeutung der Erstellung einer robusten Chronologie hervor und liefert einen ersten Schritt für die Synchronisierung des Toten Meeres mit anderen Archiven im östlichen Mittelmeerraum. Des Weiteren haben die Klimarekonstruktionen anhand der Seesedimente Variabilität auf verschiedenen Zeitskalen in den Archiven gezeigt. Diese umfassen dekadische bis tausendjährige Schwankungen im Toten Meer und sogar jährliche und sub-dekadische Schwankungen in Proxys während der rapiden Übergangszonen der JD im Gościąż See. Dies zeigt wie bedeutend es ist verschiedene Seearchive zu vergleichen um die regionalen und lokalen Auswirkungen von hemisphärischen Klimaschwankungen besser zu verstehen. Hier wurde eine beispiellose Fallstudie gezeigt, die die diversen Reaktionen unterschiedlicher Seen beleuchtet und aufzeigt wie diese von verschiedenen Klimaelementen abrupter Klimaveränderungen beeinflusst werden können. Dies hebt auch hervor, wie bedeutsam es für Klimarekonstruktionen ist das jeweilige Seesystem zu verstehen. KW - paleoclimatology KW - Paläoklimatologie KW - varved lake sediments KW - warvierte Seesedimente KW - extreme events KW - Extremereignisse KW - lake system responses KW - Seesystemreaktionen Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-558331 ER - TY - THES A1 - Gunold, Sascha T1 - Abzug unter Beobachtung T1 - Withdrawal under observation BT - Kooperation und Konkurrenz von Bundeswehr und Bundesnachrichtendienst beim Abzug der sowjetischen/russischen Truppen aus Deutschland bis 1994 BT - competition and cooperation of German Armed Forces and Federal Foreign Intelligence Service during withdrawal of Soviet/Russian forces from Germany until 1994 N2 - Mehr als vier Jahrzehnte lang beobachteten die Streitkräfte und Militärnachrichtendienste der NATO-Staaten die sowjetischen Truppen in der DDR. Hierfür übernahm in der Bundesrepublik Deutschland der Bundesnachrichtendienst (BND) die militärische Auslandsaufklärung unter Anwendung nachrichtendienstlicher Mittel und Methoden. Die Bundeswehr betrieb dagegen taktische Fernmelde- und elektronische Aufklärung und hörte vor allem den Funkverkehr der „Gruppe der sowjetischen Streitkräfte in Deutschland“ (GSSD) ab. Mit der Aufstellung einer zentralen Dienststelle für das militärische Nachrichtenwesen, dem Amt für Nachrichtenwesen der Bundeswehr, bündelte und erweiterte zugleich das Bundesministerium für Verteidigung in den 1980er Jahren seine analytischen Kapazitäten. Das Monopol des BND in der militärischen Auslandsaufklärung wurde von der Bundeswehr dadurch zunehmend infrage gestellt. Nach der deutschen Wiedervereinigung am 3. Oktober 1990 befanden sich immer noch mehr als 300.000 sowjetische Soldaten auf deutschem Territorium. Die 1989 in Westgruppe der Truppen (WGT) umbenannte GSSD sollte – so der Zwei-plus-Vier-Vertrag – bis 1994 vollständig abziehen. Der Vertrag verbot auch den drei Westmächten, in den neuen Bundesländern militärisch tätig zu sein. Die für die Militäraufklärung bis dahin unverzichtbaren Militärverbindungsmissionen der Westmächte mussten ihre Dienste einstellen. Doch was geschah mit diesem „alliierten Erbe“? Wer übernahm auf deutscher Seite die Aufklärung der sowjetischen Truppen und wer kontrollierte den Truppenabzug?  Die Studie untersucht die Rolle von Bundeswehr und BND beim Abzug der WGT zwischen 1990 und 1994 und fragt dabei nach Kooperation und Konkurrenz zwischen Streitkräften und Nachrichtendiensten. Welche militärischen und nachrichtendienstlichen Mittel und Fähigkeiten stellte die Bundesregierung zur Bewältigung des Truppenabzugs zur Verfügung, nachdem die westlichen Militärverbindungsmissionen aufgelöst wurden? Wie veränderten sich die Anforderungen an die militärische Auslandsaufklärung des BND? Inwieweit setzten sich Konkurrenz und Kooperation von Bundeswehr und BNDbeim Truppenabzug fort? Welche Rolle spielten dabei die einstigen Westmächte? Die Arbeit versteht sich nicht nur als Beitrag zur Militärgeschichte, sondern auch zur deutschen Nachrichtendienstgeschichte. N2 - The study examines the cooperation and competition between the Federal Defence Forces of Germany (Bundeswehr) and the German Foreign Intelligence Service (Bundesnachichtendienst, BND) during the withdrawal of Soviet Group of Western Forces from Germany 1990-1994. It is a common approach of military and intelligence history also reflecting the decommissioning of Military Liaison Missions of USA, United Kingdom and France (USMLM, BRIXMIS, MMFL). KW - Bundeswehr KW - Bundesnachrichtendienst KW - Gruppe der Sowjetischen Streitkräfte in Deutschland KW - Westgruppe der Truppen KW - Alliierte Militärverbindungsmissionen KW - Nachrichtendienstgeschichte KW - Militärgeschichte KW - Kalter Krieg KW - Wiedervereinigung KW - Bundeswehrkommando Ost KW - Nuklearwaffen KW - Atomwaffen KW - Spionage KW - Truppenabzug KW - allied military liaison missions KW - nuclear weapons KW - Federal Foreign Intelligence Service KW - Federal Armed Forces of Germany KW - Bundeswehrkommando Ost KW - group of Soviet forces in Germany KW - Cold War KW - military history KW - Intelligence history KW - espionage, Intelligence KW - withdrawal of troops KW - western group of forces KW - German reunification Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-571977 ER - TY - THES A1 - Chen, Hui Ching T1 - Acquisition of focus - in a cross-linguistic perspective T1 - Spracherwerb im Fokus - eine sprachübergreifende Perspektive N2 - In dieser Dissertation untersuchen wir, wie chinesischen Muttersprachler und deutschen Muttersprachler, sowohl die Erwachsenen als auch die Kinder, verschiedene linguistische Mittel, wie z. B. Wortstellungsinformationen, prosodische und lexikalische Mittel im Sprachverständnis korrekt interpretieren. N2 - Successful communication is often explored by people throughout their life courses. To effectively transfer one’s own information to others, people employ various linguistic tools, such as word order information, prosodic cues, and lexical choices. The exploration of these linguistic cues is known as the study of information structure (IS). Moreover, an important issue in the language acquisition of children is the investigation of how they acquire IS. This thesis seeks to improve our understanding of how children acquire different tools (i.e., prosodical cues, syntactical cues, and the focus particle only) of focus marking in a cross linguistic perspective. In the first study, following Szendrői and her colleagues (2017)- the sentence-picture verification task- was performed to investigate whether three- to five-year-old Mandarin-speaking children as well as Mandarin-speaking adults could apply prosodic information to recognize focus in sentences. More, in the second study, not only Mandarin-speaking adults and Mandarin-speaking children but also German-speaking adults and German-speaking children were included to confirm the assumption that children could have adult-like performance in understanding sentence focus by identifying language specific cues in their mother tongue from early onwards. In this study, the same paradigm- the sentence-picture verification task- as in the first study was employed together with the eye-tracking method. Finally, in the last study, an issue of whether five-year-old Mandarin-speaking children could understand the pre-subject only sentence was carried out and again whether prosodic information would help them to better understand this kind of sentences. The overall results seem to suggest that Mandarin-speaking children from early onwards could make use of the specific linguistic cues in their ambient language. That is, in Mandarin, a Topic-prominent and tone language, the word order information plays a more important rule than the prosodic information and even three-year-old Mandarin-speaking children could follow the word order information. More, although it seems that German-speaking children could follow the prosodic information, they did not have the adult-like performance in the object-accented condition. A feasible reason for this result is that there are more possibilities of marking focus in German, such as flexible word order, prosodic information, focus particles, and thus it would take longer time for German-speaking children to manage these linguistic tools. Another important empirical finding regarding the syntactically-marked focus in German is that it seems that the cleft construction is not a valid focus construction and this result corroborates with the previous observations (Dufter, 2009). Further, eye-tracking method did help to uncover how the parser direct their attention for recognizing focus. In the final study, it is showed that with explicit verbal context Mandarin-speaking children could understand the pre-subject only sentence and the study brought a better understanding of the acquisition of the focus particle- only with the Mandarin-speaking children. KW - information structure KW - language acquisition KW - Mandarin KW - German KW - Prosody KW - Informationsstruktur KW - Spracherwerb KW - Deutsch KW - Mandarin KW - Prosodie Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-553458 ER - TY - THES A1 - Stoll, Andreas T1 - Advanced spectroscopic instruments enabled by integrated optics N2 - The aim of this work is the study of silica Arrayed Waveguide Gratings (AWGs) in the context of applications in astronomy. The specific focus lies on the investigation of the feasibility and technology limits of customized silica AWG devices for high resolution near-infrared spectroscopy. In a series of theoretical and experimental studies, AWG devices of varying geometry, foot-print and spectral resolution are constructed, simulated using a combination of a numerical beam propagation method and Fraunhofer diffraction and fabricated devices are characterized with respect to transmission efficiency, spectral resolution and polarization sensitivity. The impact of effective index non-uniformities on the performance of high-resolution AWG devices is studied numerically. Characterization results of fabricated devices are used to extrapolate the technology limits of the silica platform. The important issues of waveguide birefringence and defocus aberration are discussed theoretically and addressed experimentally by selection of an appropriate aberration-minimizing anastigmatic AWG layout structure. The drawbacks of the anastigmatic AWG geometry are discussed theoretically. From the results of the experimental studies, it is concluded that fabrication-related phase errors and waveguide birefringence are the primary limiting factors for the growth of AWG spectral resolution. It is shown that, without post-processing, the spectral resolving power is phase-error-limited to R < 40, 000 and, in the case of unpolarized light, birefringence-limited to R < 30, 000 in the AWG devices presented in this work. Necessary measures, such as special waveguide geometries and post-fabrication phase error correction are proposed for future designs. The elimination of defocus aberration using an anastigmatic AWG geometry is successfully demonstrated in experiment. Finally, a novel, non-planar dispersive in-fibre waveguide structure is proposed, discussed and studied theoretically. N2 - Das Ziel der vorliegenden Arbeit ist die Untersuchung von Arrayed Waveguide Gratings (AWGs) auf SiO2-Basis im Kontext von Anwendungen in der Astronomie. Der besondere Fokus liegt auf der Untersuchung der Machbarkeit und der technologischen Grenzen von spezialisierten AWGs für die hochauflösende Nahinfrarot-Spektroskopie. In einer Reihe von theoretischen und experimentellen Studien werden AWGs unterschiedlicher Geometrie, Größe und spektraler Auflösung konstruiert, unter Verwendung einer numerischen Beam-Propagation-Methode (BPM) und Fraunhofer-Beugung simuliert und hinsichtlich Effizienz, spektraler Auflösung und Polarisationsempfindlichkeit charakterisiert. Der Einfluss von Variationen des effektiven Brechungsindex auf die Leistung von hochauflösenden AWGs wird numerisch untersucht. Mit hergestellten AWGs gewonnene Messergebnisse werden verwendet, um die technologischen Grenzen der SiO2-Plattform zu extrapolieren. Die relevanten Probleme der Polarisationsempfindlichkeit und der in kanonischen Rowland-Geometrien auftretenden Defokusaberration werden theoretisch diskutiert und experimentell durch die Auswahl einer geeigneten aberrationsminimierenden AWG-Struktur angegangen. Die Nachteile anastigmatischer AWGs werden theoretisch diskutiert. Aus den Ergebnissen der experimentellen Studien wird geschlossen, dass herstellungsbedingte Phasenfehler und Wellenleiter-Doppelbrechung die primären begrenzenden Faktoren für die Erhöhung der AWG-Spektralauflösung sind. Es wird gezeigt, dass das spektrale Auflösungsvermögen der in dieser Arbeit präsentierten AWGs ohne Phasenfehlerkorrektur auf R < 40, 000 und durch Doppelbrechung auf R < 30, 000 im Fall unpolarisierten Lichtes begrenzt ist. Notwendige Maßnahmen wie spezielle Wellenleitergeometrien und Phasenfehlerkorrektur nach der Herstellung werden für zukünftige AWG-Designs empfohlen. Die Eliminierung von Defokussierungsfehlern unter Verwendung einer anastigmatischen AWG-Geometrie wird erfolgreich im Experiment demonstriert. Schließlich wird eine neuartige, in eine optische Faser eingebettete, nicht-planare dispersive Wellenleiterstruktur vorgeschlagen, diskutiert und theoretisch untersucht. KW - Astrophotonics KW - Integrated spectrograph KW - planar lightwave circuit KW - arrayed waveguide grating KW - silica-on-silicon KW - Astrophotonik KW - integrierter Spektrograph KW - planare Lichtwellenleiter KW - Siliziumdioxid-auf-Silizium Y1 - 2022 ER - TY - THES A1 - Yilmaz Wörfel, Seda T1 - Adverbial Relations in Turkish-German Bilingualism T2 - Mehrsprachigkeit = Multilingualism N2 - The Turkish language in diaspora is in process of change due to different language constellations of immigrants and the dominance of majority languages. This led to a great interest in various research areas, particularly in linguistics. Against this background, this study focuses on developmental change in the use of adverbial clause-combining constructions in Turkish-German bilingual students’ oral and written text production. It illustrates the use of non-finite constructions and some unique alternative strategies to express adverbial relations with authentic examples in Turkish and German. The findings contribute to a better understanding of how bilingual competencies vary in expressing adverbial relations depending on language contact and extra-linguistic factors. Y1 - 2022 SN - 978-3-8309-4542-0 SN - 978-3-8309-9542-5 SN - 1433-0792 IS - 53 PB - Waxmann CY - Münster ER -