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    1752 research outputs found

    Statistical eco(-toxico)logy

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    Freshwaters are of immense importance for human well-being. Nevertheless, they are currently facing unprecedented levels of threat from habitat loss and degradation, overexploitation, invasive species and pollution. To prevent risks to aquatic ecosystems, chemical substances, like agricultural pesticides, have to pass environmental risk assessment (ERA) before entering the market. Concurrently, large-scale environmental monitoring is used for surveillance of biological and chemical conditions in freshwaters. This thesis examines statistical methods currently used in ERA. Moreover, it presents a national-scale compilation of chemical monitoring data, an analysis of drivers and dynamics of chemical pollution in streams and, provides a large-scale risk assessment by combination with results from ERA. Additionally, software tools have been developed to integrate different datasets used in ERA. The thesis starts with a brief introduction to ERA and environmental monitoring and gives an overview of the objectives of the thesis. Chapter 2 addresses experimental setups and their statistical analyses using simulations. The results show that current designs exhibit unacceptably low statistical power, that statistical methods chosen to fit the type of data provide higher power and that statistical practices in ERA need to be revised. In chapter 3 we compiled all available pesticide monitoring data from Germany. Hereby, we focused on small streams, similar to those considered in ERA and used threshold concentrations derived during ERA for a large-scale assessment of threats to freshwaters from pesticides. This compilation resulted in the most comprehensive dataset on pesticide exposure currently available for Germany. Using state-of-the-art statistical techniques, that explicitly take the limits of quantification into account, we demonstrate that 25% of small streams are at threat from pesticides. In particular neonicotinoid pesticides are responsible for these threats. These are associated with agricultural intensity and can be detected even at low levels of agricultural use. Moreover, our results indicated that current monitoring underestimates pesticide risks, because of a sampling decoupled from precipitation events. Additionally, we provide a first large-scale study of annual pesticide exposure dynamics. Chapters 4 and 5 describe software solutions to simplify and accelerate the integration of data from ERA, environmental monitoring and ecotoxicology that is indispensable for the development of landscape-level risk assessment. Overall, this thesis contributes to the emerging discipline of statistical ecotoxicology and shows that pesticides pose a large-scale threat to small streams. Environmental monitoring can provide a post-authorisation feedback to ERA. However, to protect freshwater ecosystems ERA and environmental monitoring need to be further refined and we provide software solutions to utilise existing data for this purpose

    Mitteilungsblatt der Universität Koblenz-Landau Nr. 5/2016

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    Erste Ordnung zur Änderung der Promotionsordnung des Fachbereiches 3: Mathematik / Naturwissenschaften der Universität Koblenz–Landau Prüfungsordnung für den Bachelorstudiengang „Mensch und Umwelt: Psychologie, Kommunikation, Ökonomie“ an der Universität Koblenz-Landau, Campus Landau Sechzehnte Ordnung zur Änderung der Prüfungsordnung für die Prüfung im lehramtsbezogenen Bachelorstudiengang an der Universität Koblenz-Landau Fünfzehnte Ordnung zur Änderung der Prüfungsordnung für die Prüfung in den Masterstudiengängen für das Lehramt an Grundschulen, das Lehramt an Realschulen plus, das Lehramt an Förderschulen sowie das Lehramt an Gymnasien an der Universität Koblenz-Landau Vierzehnte Ordnung zur Änderung der Ordnung für die Prüfung im lehramtsbezogenen Zertifikatsstudiengang (Erweiterungsprüfung) an der Universität Koblenz-Landa

    Semi-automatic feature detection in volume data through anomalies in local histograms

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    In scientific data visualization huge amounts of data are generated, which implies the task of analyzing these in an efficient way. This includes the reliable detection of important parts and a low expenditure of time and effort. This is especially important for the big-sized seismic volume datasets, that are required for the exploration of oil and gas deposits. Since the generated data is complex and a manual analysis is very time-intensive, a semi-automatic approach could on one hand reduce the time required for the analysis and on the other hand offer more flexibility, than a fully automatic approach. This master's thesis introduces an algorithm, which is capable of locating regions of interest in seismic volume data automatically by detecting anomalies in local histograms. Furthermore the results are visualized and a variety of tools for the exploration and interpretation of the detected regions are developed. The approach is evaluated by experiments with synthetic data and in interviews with domain experts on the basis of real-world data. Conclusively further improvements to integrate the algorithm into the seismic interpretation workflow are suggested

    Regional insecurity and state weakness as harbinger of terrorism and insurgency in Mali

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    Introduction: In March 2012 a secessionist-Islamist insurgency gained momentum in Mali and quickly took control of two-thirds of the state territory. Within weeks radical Islamists, drug smugglers and rebels suddenly ruled over a territory bigger than Germany. News of the abuse of the population and the introduction of harsh Sharia law spread soon, and word got out that the Malian Army had simply abandoned the land. The general echo of the IC was surprise, a reaction that was, as this research will show, as unfunded as it was unconstructive*. When Malian state structures collapsed, the world watched in shock, even though the developments couldhave been anticipated –and prevented. Ultimately, the situation had to be resolved by international forces (most notably French troops), who are still in Mali at the time of writing (Arieff 2013a: 5; Lohmann 2012: 3; Walther and Christopoulos 2015: 514f.; Shaw 2013: 204; Qantara, Interview, 2012;L’Express, Mali, 2015; Deutscher Bundestag, MINUSMA und EUTM Mali, 2016; UN, MUNISMA, 2016; Boeke and Schuurmann 2015: 801; Chivvis 2016: 93f.). This research will show that the developments in Mali in 2012 have been developing for a long time and could have been avoided. In doing so, it will also show why state security can never be analyzed or consolidated in an isolated manner. Instead, it is necessary to take into account regional dynamics and developments in order to find a comprehensive approach to security in individual states. Once state failure occurs, not only does the state itself fail, but the surrounding region equally failed to prevent the failure. Weak states are a growing concern in many world regions, particularly in Africa. As international intervention often proves unsustainable for various reasons*, the author believes that states which cannot stabilize themselves need a regional agent to support them. This regional agent should be a Regional Security Complex (RSC) asdefined by Barry Buzan and Ole Waever (Buzan and Waever 2003). As the following analysis will show, Mali is a case in point. The hope is that this study will help avoid similar failures in the future by making a strong case for the establishment of RSC’s.

    Eine empirische Studie über die Korrelation zwischen Sicherheitsschwachstellen und Qualitätseigenschaften von Software-Designs

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    Da Software heute nahezu alle Bereiche des Alltags durchdringt, ist Sicherheit von Softwaresystemen ein wichtigeres Anliegen als je zuvor. Die Sicherheit eines Softwaresystems zu bewerten stellt in der Praxis jedoch eine Herausforderung dar, da nicht viele Metriken existieren, die Sicherheitseigenschaften von Sourcecode auf Zahlenwerte abbilden. Eine geläufige Annahme ist, dass das Auftreten von Sicherheitslücken in Korrelation mit der Qualität von Software-Designs steht, allerdings fehlt es momentan an klaren Belegen für diese Annahme. Der Nachweis einer vorhandenen Korrelation kann dazu beitragen die Messung von Programmsicherheit zu optimieren, da man dann gezielt Qualitätsmetriken zum Messen von Sicherheit einsetzen könnte. Zu diesem Zweck wurden in dieser Arbeit für 50 Android-Apps aus dem Open Source-Bereich drei Sicherheits- und sieben Qualitätsmetriken, sowie Korrelationen zwischen diesen Metriken berechnet. Bei den Qualitätsmetriken handelt es sich um einfache Code-Metriken bis hin zu High-Level-Metriken, wie objektorientierte Antipatterns, die zusammen ein umfassendes Bild der Qualität vermitteln. Um die Sicherheit darzustellen wurden zwei Sichtbarkeitsmetriken zusammen mit einer Metrik, die die minimale Rechteanforderung mobiler Applikationen berechnet, ausgewählt. Es wurde festgestellt, dass auf Basis der betrachteten Evaluationsprojekte deutliche Korrelationen zwischen den meisten Qualitätsmetriken liegen. Zu den Sicherheitsmetriken wurden dahingegen keine signifikanten Korrelationen gefunden. Es werdendiese Korrelationen und deren Ursachen diskutiert und auf dieser Basis Empfehlungen formuliert.Since software influences nearly every aspect of everyday life, the security of software systems is more important than ever before. The evaluation of the security of a software system still poses a significant challenge in practice, mostly due to the lack of metrics, which can map the security properties of source code onto numeric values. It is a common assumption, that the occurrence of security vulnerabilities and the quality of the software design stand in direct correlation, but there is currently no clear evidence to support this. A proof of an existing correlation could help to optimize the measurements of program security, making it possible to apply quality measurements to evaluate it. For this purpose, this work evaluates fifty open-source android applications, using three security and seven quality metrics. It also considers the correlations between the metrics. The quality metrics range from simple code metrics to high-level metrics such as object-oriented anti-patterns, which together provide a comprehensive picture of the quality. Two visibility metrics, along with a metric that computes the minimal permission request for mobile applications, were selected to illustrate the security. Using the evaluation projects, it was found that there is a clear correlation between most quality metrics. By contrast, no significant correlations were found using the security metrics. This work discusses the correlations and their causes as well as further recommendations based on the findings

    KONECS "Koblenzer Netzwerk Campus, Schulen & Studienseminare" : Abschlussbericht

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    Bericht über die Arbeit der ersten drei Projektjahre des vom 01.01.2013 bis 31.12.2015 vom Ministerium für Bildung, Wissenschaft, Weiterbildung und Kultur Rheinland-Pfalz geförderten Projekts KONEC

    Mitteilungsblatt der Universität Koblenz-Landau Nr. 1/2017

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    Wahlordnung der örtlichen Studierendenschaft der Universität Koblenz-Landau, Campus Landau Ordnung zur Änderung der Einschreibeordnung für die Universität Koblenz-Landau Promotionsordnung des Fachbereichs 5: Erziehungswissenschaften der Universität Koblenz-Landau Erste Ordnung zur Änderung der Promotionsordnung des Fachbereiches 6: Kultur- und Sozialwissenschaften der Universität Koblenz–Landau Änderungssatzung zur Satzung über die Festsetzung von Zulassungszahlen an der Universität Koblenz- Landau für das Studienjahr 2016/2017 Erste Ordnung zur Änderung der Ordnung für die Eignungsprüfung Musik an der Universität Koblenz- Landau Siebzehnte Ordnung zur Änderung der Prüfungsordnung für die Prüfung im lehramtsbezogenen Bachelorstudiengang an der Universität Koblenz- Landa

    Evolutionary Genomics in Daphnia

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    For a comprehensive understanding of evolutionary processes and for providing reliable prognoses about the future consequences of environmental change, it is essential to reveal the genetic basis underlying adaptive responses. The importance of this goal increases in light of ongoing climate change, which confronts organisms worldwide with new selection pressures and requires rapid evolutionary change to avoid local extinction. Thereby, freshwater ectotherms like daphnids are particularly threatened. Unraveling the genetic basis of local adaptation is complicated by the interplay of forces affecting patterns of genetic divergence among populations. Due to their key position in freshwater communities, cyclic parthenogenetic mode of reproduction and resting propagules (which form biological archives), daphnids are particularly suited for this purpose. The aim of this thesis was to assess the impact of local thermal selection on the Daphnia longispina complex and to reveal the underlying genetic loci. Therefore, I compared genetic differentiation among populations containing Daphnia galeata, Daphnia longispina and their interspecific hybrids across time, space, and species boundaries. I revealed strongly contrasting patterns of genetic differentiation between selectively neutral and functional candidate gene markers, between the two species, and among samples from different lakes, suggesting (together with a correlation with habitat temperatures) local thermal selection acting on candidate gene TRY5F and indicating adaptive introgression. To reveal the candidate genes’ impact on fitness, I performed association analyses among data on genotypes and phenotypic traits of D. galeata clones from seven populations. The tests revealed a general temperature effect as well as inter-population differences in phenotypic traits and imply a possible contribution of the candidate genes to life-history traits. Finally, utilizing a combined population transcriptomic and reverse ecology approach, I introduced a methodology with a wide range of applications in evolutionary biology and revealed that local thermal selection was probably a minor force in shaping sequence and gene expression divergence among four D. galeata populations, but contributed to sequence divergence among two populations. I identified many transcripts possibly under selection or contributing strongly to population divergence, a large amount thereof putatively under local thermal selection, and showed that genetic and gene expression variation is not depleted specifically in temperature-related candidate genes. In conclusion, I detected signs of local adaptation in the D. longispina complex across space, time, and species barriers. Populations and species remained genetically divergent, although increased gene flow possibly contributed, together with genotypes recruited from the resting egg bank, to the maintenance of standing genetic variation. Further work is required to accurately determine the influence of introgression and the effects of candidate genes on individual fitness. While I found no evidence suggesting a response to intense local thermal selection, the high resilience and adaptive potential regarding environmental change I observed suggest positive future prospects for the populations of the D. longispina complex. However, overall, due to the continuing environmental degradation, daphnids and other aquatic invertebrates remain vulnerable and threatened

    Campuszeitung Ausg. 1/2017

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    10 Jahre Kulturwissenschaft Innovation für das autonome Fahren Griechenlands Krise und die prinzipiellen Bedingungen für produktives Arbeiten Gesundheitsmanagement am Campus Holzfaser-Kunststoff-Verbundwerkstoff

    Spectral Graph Convolutional Networks for Part-of-Speech Tagging

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    Part-of-Speech tagging is the process of assigning words with similar grammatical properties to a part of speech (PoS). In the English language, PoS-tagging algorithms generally reach very high accuracy. This thesis undertakes the task to test against these accuracies in PoS-tagging as a qualitative measure in classification capabilities for a recently developed neural network model, called graph convolutional network (GCN). The novelty proposed in this thesis is to translate a corpus into a graph as a direct input for the GCN. The experiments in this thesis serve as a proof of concept with room for improvements

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