TY - JOUR A1 - Ayzel, Georgy A1 - Heistermann, Maik A1 - Winterrath, Tanja T1 - Optical flow models as an open benchmark for radar-based precipitation nowcasting (rainymotion v0.1) JF - Geoscientific model development N2 - Quantitative precipitation nowcasting (QPN) has become an essential technique in various application contexts, such as early warning or urban sewage control. A common heuristic prediction approach is to track the motion of precipitation features from a sequence of weather radar images and then to displace the precipitation field to the imminent future (minutes to hours) based on that motion, assuming that the intensity of the features remains constant (“Lagrangian persistence”). In that context, “optical flow” has become one of the most popular tracking techniques. Yet the present landscape of computational QPN models still struggles with producing open software implementations. Focusing on this gap, we have developed and extensively benchmarked a stack of models based on different optical flow algorithms for the tracking step and a set of parsimonious extrapolation procedures based on image warping and advection. We demonstrate that these models provide skillful predictions comparable with or even superior to state-of-the-art operational software. Our software library (“rainymotion”) for precipitation nowcasting is written in the Python programming language and openly available at GitHub (https://github.com/hydrogo/rainymotion, Ayzel et al., 2019). That way, the library may serve as a tool for providing fast, free, and transparent solutions that could serve as a benchmark for further model development and hypothesis testing – a benchmark that is far more advanced than the conventional benchmark of Eulerian persistence commonly used in QPN verification experiments. KW - machine KW - system Y1 - 2019 U6 - https://doi.org/10.5194/gmd-12-1387-2019 SN - 1991-9603 SN - 1991-959X IS - 12 SP - 1387 EP - 1402 PB - Copernicus Publications CY - Göttingen ER - TY - THES A1 - Reeg, Jette T1 - Simulating the impact of herbicide drift exposure on non-target terrestrial plant communities T1 - Simulation der Auswirkungen von Herbizid-Drift-Expositionen auf Gemeinschaften von Nichtzielpflanzen N2 - In Europe, almost half of the terrestrial landscape is used for agriculture. Thus, semi-natural habitats such as field margins are substantial for maintaining diversity in intensively managed farmlands. However, plants located at field margins are threatened by agricultural practices such as the application of pesticides within the fields. Pesticides are chemicals developed to control for undesired species within agricultural fields to enhance yields. The use of pesticides implies, however, effects on non-target organisms within and outside of the agricultural fields. Non-target organisms are organisms not intended to be sprayed or controlled for. For example, plants occurring in field margins are not intended to be sprayed, however, can be impaired due to herbicide drift exposure. The authorization of plant protection products such as herbicides requires risk assessments to ensure that the application of the product has no unacceptable effects on the environment. For non-target terrestrial plants (NTTPs), the risk assessment is based on standardized greenhouse studies on plant individual level. To account for the protection of plant populations and communities under realistic field conditions, i.e. extrapolating from greenhouse studies to field conditions and from individual-level to community-level, assessment factors are applied. However, recent studies question the current risk assessment scheme to meet the specific protection goals for non-target terrestrial plants as suggested by the European Food Safety Authority (EFSA). There is a need to clarify the gaps of the current risk assessment and to include suitable higher tier options in the upcoming guidance document for non-target terrestrial plants. In my thesis, I studied the impact of herbicide drift exposure on NTTP communities using a mechanistic modelling approach. I addressed main gaps and uncertainties of the current risk assessment and finally suggested this modelling approach as a novel higher tier option in future risk assessments. Specifically, I extended the plant community model IBC-grass (Individual-based community model for grasslands) to reflect herbicide impacts on plant individuals. In the first study, I compared model predictions of short-term herbicide impacts on artificial plant communities with empirical data. I demonstrated the capability of the model to realistically reflect herbicide impacts. In the second study, I addressed the research question whether or not reproductive endpoints need to be included in future risk assessments to protect plant populations and communities. I compared the consequences of theoretical herbicide impacts on different plant attributes for long-term plant population dynamics in the community context. I concluded that reproductive endpoints only need to be considered if the herbicide effect is assumed to be very high. The endpoints measured in the current vegetative vigour and seedling emergence studies had high impacts for the dynamic of plant populations and communities already at lower effect intensities. Finally, the third study analysed long-term impacts of herbicide application for three different plant communities. This study highlighted the suitability of the modelling approach to simulate different communities and thus detecting sensitive environmental conditions. Overall, my thesis demonstrates the suitability of mechanistic modelling approaches to be used as higher tier options for risk assessments. Specifically, IBC-grass can incorporate available individual-level effect data of standardized greenhouse experiments to extrapolate to community-level under various environmental conditions. Thus, future risk assessments can be improved by detecting sensitive scenarios and including worst-case impacts on non-target plant communities. N2 - Fast die Hälfte der gesamten Landfläche in Europa wird für landwirtschaftliche Zwecke genutzt. Daher sind halb-natürliche Gebiete, wie zum Beispiel Ackerränder, von besonderer Bedeutung für den Artenreichtum in intensiv genutzten Ackerlandschaften. Vor allem in den intensiv genutzten Äckern werden Chemikalien eingesetzt um die Erträge zu erhöhen. So werden zum Beispiel Pflanzenschutzmittel eingesetzt, um Unkräuter im Acker zu vernichten. Allerdings kann dieser Einsatz auch Auswirkungen auf sogenannte Nicht-Zielarten haben. Dies sind solche Arten oder Artindividuen, die z.B. innerhalb vom Acker nicht in Konkurrenz mit den darauf wachsenden Getreidesorten stehen oder sich nicht innerhalb vom Feld befinden aber dennoch den Pflanzenschutzmitteln ausgesetzt sind. Um den Artenreichtum in halb-natürlichen Gebieten zu schützen, ist es daher notwendig eine Risikoabschätzung durchzuführen bevor ein Pflanzenschutzmittel für den Verkauf und die Anwendung zugelassen wird. Für terrestrische Nicht-Zielpflanzen erfolgt eine solche Risikoabschätzung basierend auf standardisierten Gewächshausexperimenten, in denen die Effekte auf der Ebene von Einzelindividuen gemessen werden. Um das letztliche Risiko im Freiland für ganze Pflanzengemeinschaften abzuschätzen, werden sogenannte Unsicherheitsfaktoren hinzugenommen. Allerdings stellen neuere Studien in Frage, ob der derzeitige Ansatz ausreichend sicher ist. Dies gilt vor allem in Bezug auf die aktuellen speziellen Schutzziele, die den Fokus auf den Schutz von Pflanzengemeinschaften und Artenreichtum legen. Es ist daher zwingend notwendig die Wissenslücken der derzeitigen Risikoabschätzung zu schließen und Optionen zu weiteren Studien zu geben, die das Risiko vom Einsatz von Pflanzenschutzmitteln für Nicht-Zielpflanzen realistischer abschätzen können. In meiner Dissertation nutze ich einen mechanistischen Modellierungsansatz um den Einfluss von Pflanzenschutzmitteln auf Nicht-Zielpflanzengemeinschaften zu untersuchen. Hierbei spreche ich die wesentlichen Wissenslücken und Unklarheiten der aktuellen Risikoabschätzung an und schlage zusammenfassend eine neue Option für eine realistischere Abschätzung des Risikos vor. Hierzu integriere ich den Einfluss von Herbiziden auf Einzelindividuen in das Pflanzengemeinschaftsmodell IBC-grass. In meiner ersten Studie vergleiche ich Modellvorhersagen von kurzzeitigen Herbizideffekten in künstlichen Artgemeinschaften mit experimentellen Daten. Mit der Studie zeige ich, dass das Modell den Einfluss von Herbiziden auf die Pflanzengemeinschaft realistisch vorhersagen kann. In der zweiten Studie fokussiere ich mich auf die Frage, ob Effekte auf weitere Pflanzeneigenschaften, insbesondere Fortpflanzungseigenschaften, wie zum Beispiel die Samenproduktion, im Rahmen der standardisierten Gewächshausstudien gemessen werden sollten. Die Studie zeigt, dass die derzeitig gemessenen Pflanzeneigenschaften am meisten Einfluss auf die Dynamiken einer Pflanzengesellschaft haben und somit schon geringe Schädigungen dieser Eigenschaften auf Individuenebene Auswirkungen für die Gemeinschaft haben. Dahingegen führten nur sehr starke Effekte auf die Fortpflanzungseigenschaften zu einem Einfluss auf Gemeinschaftsebene. Mit der letzten Studie zeige ich, dass der Modellansatz dazu genutzt werden kann Auswirkungen für unterschiedliche Pflanzengemeinschaften darzustellen. Zusammengefasst zeigen die Studien meiner Dissertation, dass mechanistische Modellierung eine geeignete Option für eine realistischere Risikoabschätzung ist. Auf Grund des besonderen Designs von IBC-grass können die durch derzeitige Gewächshausstudien zur Verfügung stehenden empirischen Daten in das Modell eingearbeitet werden und somit das Risiko auf Gemeinschaftsebene abgeschätzt werden. Mit Hilfe des Modells können mehrere Umweltbedingungen getestet werden und somit Extremszenarien abgedeckt werden. Meine Studien tragen dazu bei, zukünftige Risikoabschätzungen für Nicht-Zielpflanzen zu verbessern. KW - ecological modelling KW - pesticide KW - risk assessment KW - plant community KW - non-target organisms KW - ökologische Modellierung KW - Pestizide KW - Risikoabschätzung KW - Pflanzengemeinschaft KW - Nicht-Zielorganismen Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-429073 ER - TY - GEN A1 - Sieg, Tobias A1 - Shinko, Thomas A1 - Vogel, Kristin A1 - Mechler, Reinhard A1 - Merz, Bruno A1 - Kreibich, Heidi T1 - Integrated assessment of short-term direct and indirect economic flood impacts including uncertainty quantification T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Understanding and quantifying total economic impacts of flood events is essential for flood risk management and adaptation planning. Yet, detailed estimations of joint direct and indirect flood-induced economic impacts are rare. In this study an innovative modeling procedure for the joint assessment of short-term direct and indirect economic flood impacts is introduced. The procedure is applied to 19 economic sectors in eight federal states of Germany after the flood events in 2013. The assessment of the direct economic impacts is object-based and considers uncertainties associated with the hazard, the exposed objects and their vulnerability. The direct economic impacts are then coupled to a supply-side Input-Output-Model to estimate the indirect economic impacts. The procedure provides distributions of direct and indirect economic impacts which capture the associated uncertainties. The distributions of the direct economic impacts in the federal states are plausible when compared to reported values. The ratio between indirect and direct economic impacts shows that the sectors Manufacturing, Financial and Insurance activities suffered the most from indirect economic impacts. These ratios also indicate that indirect economic impacts can be almost as high as direct economic impacts. They differ strongly between the economic sectors indicating that the application of a single factor as a proxy for the indirect impacts of all economic sectors is not appropriate. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 708 KW - June 2013 KW - Damage KW - Model KW - Inoperability KW - Disasters KW - Hazards KW - Germany KW - Losses KW - Event KW - Costs Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-429119 IS - 708 ER - TY - JOUR A1 - Sieg, Tobias A1 - Schinko, Thomas A1 - Vogel, Kristin A1 - Mechler, Reinhard A1 - Merz, Bruno A1 - Kreibich, Heidi T1 - Integrated assessment of short-term direct and indirect economic flood impacts including uncertainty quantification JF - PLoS ONE N2 - Understanding and quantifying total economic impacts of flood events is essential for flood risk management and adaptation planning. Yet, detailed estimations of joint direct and indirect flood-induced economic impacts are rare. In this study an innovative modeling procedure for the joint assessment of short-term direct and indirect economic flood impacts is introduced. The procedure is applied to 19 economic sectors in eight federal states of Germany after the flood events in 2013. The assessment of the direct economic impacts is object-based and considers uncertainties associated with the hazard, the exposed objects and their vulnerability. The direct economic impacts are then coupled to a supply-side Input-Output-Model to estimate the indirect economic impacts. The procedure provides distributions of direct and indirect economic impacts which capture the associated uncertainties. The distributions of the direct economic impacts in the federal states are plausible when compared to reported values. The ratio between indirect and direct economic impacts shows that the sectors Manufacturing, Financial and Insurance activities suffered the most from indirect economic impacts. These ratios also indicate that indirect economic impacts can be almost as high as direct economic impacts. They differ strongly between the economic sectors indicating that the application of a single factor as a proxy for the indirect impacts of all economic sectors is not appropriate. KW - June 2013 KW - Damage KW - Model KW - Inoperability KW - Disasters KW - Hazards KW - Germany KW - Losses KW - Event KW - Costs Y1 - 2019 U6 - https://doi.org/10.1371/journal.pone.0212932 SN - 1932-6203 VL - 14 IS - 4 PB - Public Library of Science CY - San Francisco ER - TY - RPRT A1 - McLachlan, Campbell T1 - The Double-facing Foreign Relations Function of the Executive and Its Self-enforcing Obligation to Comply with International Law T2 - KFG Working Paper Series N2 - How does the international Rule of Law apply to constrain the conduct of the Executive within a constitutional State that adopts a dualist approach to the reception of international law? This paper argues that, so far from being inconsistent with the concept of the Rule of Law, the Executive within a dualist constitution has a self-enforcing obligation to abide by the obligations of the State under international law. This is not dependent on Parliament’s incorporation of treaty obligations into domestic law. It is the correlative consequence of the allocation to the Executive of the power to conduct foreign relations. The paper develops this argument in response to recent debate in the United Kingdom on whether Ministers have an obligation to comply with international law–a reference that the Government removed from the Ministerial Code. It shows that such an obligation is consistent with both four centuries of the practice of the British State and with principle. T3 - KFG Working Paper Series - 30 Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-429088 IS - 30 ER - TY - THES A1 - Kav, Batuhan T1 - Membrane adhesion mediated via lipid-anchored saccharides T1 - Membranadhäsion durch Lipid-verankerte Saccharide N2 - Membrane adhesion is a fundamental biological process in which membranes are attached to neighboring membranes or surfaces. Membrane adhesion emerges from a complex interplay between the binding of membrane-anchored receptors/ligands and the membrane properties. In this work, we study membrane adhesion mediated by lipid-anchored saccharides using microsecond-long full-atomistic molecular dynamics simulations. Motivated by neutron scattering experiments on membrane adhesion via lipid-anchored saccharides, we investigate the role of LeX, Lac1, and Lac2 saccharides and membrane fluctuations in membrane adhesion. We study the binding of saccharides in three different systems: for saccharides in water, for saccharides anchored to essentially planar membranes at fixed separations, and for saccharides anchored to apposing fluctuating membranes. Our simulations of two saccharides in water indicate that the saccharides engage in weak interactions to form dimers. We find that the binding occurs in a continuum of bound states instead of a certain number of well-defined bound structures, which we term as "diffuse binding". The binding of saccharides anchored to essentially planar membranes strongly depends on separation of the membranes, which is fixed in our simulation system. We show that the binding constants for trans-interactions of two lipid-anchored saccharides monotonically decrease with increasing separation. Saccharides anchored to the same membrane leaflet engage in cis-interactions with binding constants comparable to the trans-binding constants at the smallest membrane separations. The interplay of cis- and trans-binding can be investigated in simulation systems with many lipid-anchored saccharides. For Lac2, our simulation results indicate a positive cooperativity of trans- and cis-binding. In this cooperative binding the trans-binding constant is enhanced by the cis-interactions. For LeX, in contrast, we observe no cooperativity between trans- and cis-binding. In addition, we determine the forces generated by trans-binding of lipid-anchored saccharides in planar membranes from the binding-induced deviations of the lipid-anchors. We find that the forces acting on trans-bound saccharides increase with increasing membrane separation to values of the order of 10 pN. The binding of saccharides anchored to the fluctuating membranes results from an interplay between the binding properties of the lipid-anchored saccharides and membrane fluctuations. Our simulations, which have the same average separation of the membranes as obtained from the neutron scattering experiments, yield a binding constant larger than in planar membranes with the same separation. This result demonstrates that membrane fluctuations play an important role at average membrane separations which are seemingly too large for effective binding. We further show that the probability distribution of the local separation can be well approximated by a Gaussian distribution. We calculate the relative membrane roughness and show that our results are in good agreement with the roughness values reported from the neutron scattering experiments. N2 - Membranadhäsion ist ein fundamentaler biologischer Prozess, bei dem Membranen sich an benachbarte Membranen oder Oberfläche anheften. Membranadhäsion entstammt einem komplexen Zusammenspiel aus Bindungen zwischen Membranverankerten Rezeptor/Ligand-Bindungen und den Membraneigenschaften selbst. In dieser Arbeit untersuchen wir Membranadhäsion vermittelt durch Lipid-verankerte Saccharide mittels Mikrosekunden-langer voll-atomistischer molekular-dynamischer Simulationen. Motiviert durch Neutronen Scattering Experimente von Lipid-verankerten Sacchariden und deren Einfluss auf Membranadhäsion, untersuchen wir die Rolle der Saccharide LeX, Lac1 und Lac2 sowie der Membranfluktuationen in Membranadhäsion. Wir untersuchen die Bindungen der Saccharide in drei verschiedenen Systemen: In Wasser, verankert in quasi-ebenflächigen Membranen bei fixierten Abständen, und verankert in aneinanderliegenden, fluktuierenden Membranen. Unsere Simulationen von zwei Sacchariden in Wasser deuten darauf hin, dass diese Saccharide durch schwache Interaktionen Dimere formen. Anstelle einiger klar definierter Bindungsstrukturen, finden wir ein Kontinuum von gebundenen Zuständen vor, das wir als "diffuse Bindung" bezeichnen. Die Bindungen von Sacchariden in quasi-ebenflächigen Membranen hängt stark vom Abstand zwischen diesen Membranen ab, der in unserem System fest gewählt ist. Wir zeigen, dass die Bundungskonstanten für trans-Interaktionen zweier Lipid-verankerter Saccharide monoton abnimmt mit zunehmendem Abstand. Saccharide verankert auf der selben Membran wechselwirken in cis-Interaktionen, deren Bindungskonstanten denen der trans-Interaktionen bei dem kleinsten gewählten Membranabstand ähneln. Das Zusammenspiel der cis- und trans-Interaktionen kann in Simulationssystemen mit vielen Lipid-verankerten Sacchariden untersucht werden. Für Lac2 deuten unsere Simulationen auf eine Kooperativität zwischen cis- und trans-Interaktionen hin: In diesem kooperativen Bindungsprozess verstärkt die cis-Interkation die trans-Bindunskonstante. Für LeX hingegen stellen wir keine Kooperativität zwischen trans- und cis-Bindung fest. Zusätzlich bestimmen wir die generierten Kräfte, die durch trans-gebundene Lipid-verankerte Saccharide in ebenflächigen Membranen und die resultierende Ablenkung der Lipid-Anker hervorgerufen werden. Wir stellen fest, dass mit gesteigertem Abstand zwischen den Membranen, die auf trans-gebundene Saccharide wirkenden Kräfte auf bis zu 10 pN ansteigen. Die Bindungen von Sacchariden, die in fluktuierenden Membranen verankert sind, resultieren aus einem Zusammenspiel zwischen den Eigenschaften dieser Lipid-verankerten Saccharide und den Membranfluktuationen. Unsere Simulationen, die den Membranabstand aufweisen, der auch in den Neutron Scattering Experimenten ermittelt wurde, resultieren in einer Bindungskonstante, die größer ist als jene in quasi-ebenflächigen Membranen bei dem gleichen Abstand. Dieses Ergebnis demonstriert, dass Membranfluktuationen eine wichtige Rolle spielen bei mittleren Membranabstünden, die sonst scheinbar zu groß sind für effektive Bindungsprozesse. Weiterhin zeigen wir, dass die Wahrscheinlichkeitsverteilung der lokalen Abstünde gut durch eine Gauss-Verteilung approximiert werden kann. Wir berechnen die relative Membranrauigkeit und zeigen, dass unsere Ergebnisse gut mit denen der Neutron Scattering Experimente vereinbar sind. KW - molecular dynamics KW - membrane adhesion KW - lipid-anchored saccharide KW - lipid membranes KW - membrane adhesion forces KW - Molekulardynamik KW - Membranadhäsion KW - lipid-verankerte Saccharide KW - Lipidmembran KW - Membran-Adhäsionskräfte Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-428790 ER - TY - THES A1 - Schleicher, Anja Maria T1 - The significance of clay minerals in active fault zones N2 - Die vorliegende Habilitationsschrift umfasst Forschungsergebnisse aus Studien, die sich mit Fluid-Gesteins-Wechselwirkungen und Deformationsprozessen in aktiven Störungszonen befassen, wobei der Einfluss der Tonminerale auf das geochemische und hydromechanische Verhalten dieser Störungen im Vordergrund steht. Kernproben (core) und Bohrklein (cuttings) aus vier verschiedenen Bohrprojekten an der San Andreas Störung (USA), der Nankai Trough Subduktionszone und der Japan Trench Subduktionszone (Japan), sowie der Alpine Störung in Neuseeland wurden untersucht. Die von ICDP (International Continental Scientific Drilling Program) und IODP (International Ocean Discovery Program) unterstützten Projekte verfolgen alle das Ziel, das Verhalten von Erdbeben besser zu verstehen. In Kapitel 1 werden in einer kurzen Einleitung die allgemeinen thematischen Grundlagen und Ziele der Arbeit beschrieben. Kapitel 2 umfasst den Stand der Forschung, eine kurze Beschreibung der einzelnen Bohrprojekte und Standorte, sowie eine Zusammenfassung der wichtigsten Messmethoden. Kapitel 3 beinhaltet insgesamt zehn wissenschaftliche Arbeiten, die alle in einem methodisch-thematischen Zusammenhang stehen. Die Manuskripte wurden in den Jahren 2006-2015 veröffentlicht, wobei weitere Arbeiten aus diesem Themenbereich im Literaturverzeichnis vermerkt sind. Sie gehen auf unterschiedliche Fragestellungen um die Bildung und das Verhalten von Tonmineralen in aktiven Störungszonen ein. Insgesamt sechs Publikationen beinhalten Daten und Forschungsergebnisse, die im Rahmen des SAFOD Projektes, USA (San Andreas Fault Observatory at Depth) erstellt wurden. Hier wurde vor allem auf die Fluid-Gesteins-Wechselwirkungsprozesse im Störungsgestein und die daraus resultierende Bildung von Tonmineralen eingegangen. Drei weitere Arbeiten wurden im Rahmen des NanTroSEIZE Projektes, Japan (Nankai Trough Seismogenic Zone Experiment) und des JFAST Projektes, Japan (Japan Trench Fast Drilling Project) erstellt. Hier steht vor allem das Verhalten von quellfähigen Tonmineralen auf sich ändernde Umgebungsbedingungen (z.B. Temperatur und Feuchtigkeit) im Mittelpunkt. Die zehnte hier vorgestellte Veröffentlichung betrifft Analysen rund um das DFDP Projekt (Deep Fault Drilling Project) in Neuseeland, wobei hier die Deformation von Tonmineralen und das hydro-mechanische Verhalten der Störungszone im Vordergrund stehen. In neun Veröffentlichungen war ich als Erstautor für die Vorbereitung des Projektes, das Erstellen der Daten und die Fertigstellung der Manuskripte zuständig. In einer Publikation war ich als Mitautorin für die elektronenmikroskopischen Analysen und deren Interpretation verantwortlich. Die wichtigsten Ergebnisse der in Kapitel 3 vorgelegten Arbeiten werden in Kapitel 4 unter Berücksichtigung neuer Publikationen diskutiert. Nach der Beschreibung der Thesen in Kapitel 5 werden in Kapitel 6 „Outlook“ die Highlights zukünftiger Forschungspläne am GFZ näher beschrieben. Die Habilitationsschrift endet mit dem Anhang, in welchem unter anderem das Laborequipment genauer beschrieben wird, sowie die Publikationen, Konferenzbeiträge und Lehrbeiträge aufgelistet sind. N2 - The habilitation thesis presented here includes results from several studies dealing with fluid-rock interactions and rock deformation processes in active fault zones. The focus in all of these studies is on the influence of clay minerals on the geochemical and the hydro-mechanical behavior of the fault rocks. The research was conducted on rock cores and cuttings from four scientific drilling projects at the San Andreas Fault (USA), the Nankai Trough subduction zone and the Japan Trench subduction zone (Japan), as well as the Alpine Fault in New Zealand. These ICDP (International Continental Scientific Drilling Program) and IODP (International Ocean Discovery Program) funded projects were all conducted with the aim to monitor and better understand earthquakes. Chapter 1 contains a short introduction to the topic with basic principles and objectives regarding the research approach. Chapter 2 describes the state of the art in clay mineral and fault zone science, gives a short description of the individual drilling projects and their locations on which the research was based, and summarizes the most important analytical methods used. Chapter 3 comprises ten peer-reviewed publications that are connected thematically and methodologically. The papers were published in the years 2006-2015, and additional related publications including myself as co-author are given in the literature list. The ten publications address different questions concerning the formation of clay minerals and processes of fluid-rock interaction in active fault zones. Six papers contain results from the SAFOD drilling project, USA (San Andreas Fault Observatory at Depth), with the main focus on fluid-rock interaction processes in fault rocks and the formation and location of clay minerals. Three publications report on research from the NanTroSEIZE drilling project (Nankai Trough Seismogenic Zone Experiment) and the JFAST drilling project (Japan Trench Fast Drilling Project). Both projects are situated in Japan. Here, the swelling behavior of smectite clay minerals in relation to changing environmental conditions (e.g. temperature and/or humidity) was investigated. The last publication included here concerns a study from the DFDP project (Deep Fault Drilling Project) in New Zealand, where I investigated the deformation of clay minerals on the context of the hydro-mechanical behavior of the fault zone rocks. I was first author in nine of the publications and in charge of the project preparation, measurements and data analyses, and the completion of the manuscript. As co-author on the other publication I was responsible for electronmicroscopy analyses (SEM and TEM) and their interpretation. The key results from the publications in Chapter 3 are discussed in Chapter 4 with additional considerations from more recent papers. Following the major theses in Chapter 5, Chapter 6 highlights a future research project in clay mineralogy research at the GFZ. An appendix includes more detailed descriptions of the laboratory equipment and lists of all publications, conference contributions and teaching courses and modules. KW - fault zone KW - Störungszone KW - clay mineral KW - fluid-rock interaction KW - Tonminerale KW - Fluid-Gesteins Wechselwirkung Y1 - 2019 ER - TY - THES A1 - Moffitt, Ursula Elinor T1 - On being and belonging T2 - Othering, islamophobia, and identity in contemporary Germany Y1 - 2019 ER - TY - THES A1 - Tinpun, Kittisak T1 - Relative rank of infinite full transformation semigroups with restricted range Y1 - 2019 ER - TY - RPRT A1 - Müller, Kai-Uwe A1 - Wrohlich, Katharina T1 - Does subsidized care for toddlers increase maternal labor supply? BT - Evidence from a large-scale expansion of early childcare T2 - CEPA Discussion Papers N2 - Expanding public or publicly subsidized childcare has been a top social policy priority in many industrialized countries. It is supposed to increase fertility, promote children’s development and enhance mothers’ labor market attachment. In this paper, we analyze the causal effect of one of the largest expansions of subsidized childcare for children up to three years among industrialized countries on the employment of mothers in Germany. Identification is based on spatial and temporal variation in the expansion of publicly subsidized childcare triggered by two comprehensive childcare policy reforms. The empirical analysis is based on the German Microcensus that is matched to county level data on childcare availability. Based on our preferred specification which includes time and county fixed effects we find that an increase in childcare slots by one percentage point increases mothers’ labor market participation rate by 0.2 percentage points. The overall increase in employment is explained by the rise in part-time employment with relatively long hours (20-35 hours per week). We do not find a change in full-time employment or lower part-time employment that is causally related to the childcare expansion. The effect is almost entirely driven by mothers with medium-level qualifications. Mothers with low education levels do not profit from this reform calling for a stronger policy focus on particularly disadvantaged groups in coming years. T3 - CEPA Discussion Papers - 9 KW - childcare provision KW - mother’s labor supply KW - generalized difference-in-difference Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427727 SN - 2628-653X IS - 9 ER - TY - THES A1 - Civitillo, Sauro T1 - Teachers’ cultural diversity beliefs and culturally responsive practices T1 - Überzeugungen von Lehrern zur kulturellen Vielfalt und kultursensiblen Unterricht N2 - The present dissertation about teachers’ cultural diversity beliefs and culturally responsive practices includes a general introduction (Chapter 1), a systematic literature review (Chapter 2), three empirical studies (Chapter 3, 4, and 5) and it ends with a general discussion and conclusion (Chapter 6). The major focus of investigation laid in creating a deeper understanding of teachers’ beliefs about cultural diversity and how those beliefs are related to teaching practices, which could or could not be considered to be culturally responsive. In this dissertation, I relied on insights from theoretical perspectives that derived from the field of psychology such as social cognitive theory and intergroup ideologies, as well as from the field of multicultural education such as culturally responsive teaching. In Chapter 1, I provide the background of this dissertation, with contextual information regarding the German educational system, the theoretical framework used and the main research objectives of each study. In Chapter 2, I conducted a systematic review of the existing international studies on trainings addressing cultural diversity beliefs with pre-service teachers. More specifically, the aims of the systematic literature review were (1) to provide a description of main components and contextual characteristics of teacher trainings targeting cultural diversity beliefs, (2) report the training effects, and (3) detail the methodological strengths and weaknesses of these studies. By examining the main components and contextual characteristics of teacher trainings, the effects on beliefs about cultural diversity as well as the methodological strengths and weaknesses of these studies in a single review, I took an integrated approach to these three processes. To review the final pool of studies (N = 36) I used a descriptive and narrative approach, relying primarily on the use of words and text to summarise and explain findings of the synthesis. The three empirical studies that follow, all highlight aspects of how far and how teacher beliefs about cultural diversity translate into real-world practices in schools. In Chapter 3, to expand the validity of culturally responsive teaching to the German context, I aimed at verifying the dimensional structure of German version of the Culturally Responsive Classroom Management Self-Efficacy Scale (CRCMSES; Siwatu, Putman, Starker-Glass, & Lewis, 2015). I conducted Exploratory and Confirmatory Factor Analysis, and run correlations between the subscales of the CRCMSES and a measure of cultural diversity- related stress. Data (n = 504) used for the first empirical study (Chapter 3) were collected in the InTePP-project (Inclusive Teaching Professionalization Panel) in which pre-service teachers’ competencies and beliefs were assessed longitudinally at two universities: the University of Potsdam and the University of Cologne. In the second empirical study, which forms Chapter 4, the focus is on teachers’ practices resembling school approaches to cultural diversity. In this study, I investigated two research questions: (1a) What types of descriptive norms regarding cultural diversity are perceived by teachers and students with and without an immigrant background and (1b) what is their degree of congruence? Additionally, I was also interested in how are teachers’ and students’ perceptions of descriptive norms about cultural diversity related to practices and artefacts in the physical and virtual school environment? Data for the second empirical study (Chapter 4) were previously collected in a dissertation project of doctor Maja Schachner funded by the federal program “ProExzellenz” of the Free State of Thuringia. Adopting a mixed-methods research design I conducted a secondary analysis of data from teachers’ (n = 207) and students’ (n = 1,644) gathered in 22 secondary schools in south-west Germany. Additional sources of data in this study were based on pictures of school interiors (hall and corridors) and sixth-grade classrooms’ walls (n = 2,995), and screenshots from each school website (n = 6,499). Chapter 5 addresses the question of how culturally responsive teaching, teacher cultural diversity beliefs, and self-reflection on own teaching are related. More specifically, in this study I addressed two research questions: (1) How does CRT relate to teachers’ beliefs about incorporating cultural diversity content into daily teaching and learning activities? And (2) how does the level of teachers’ self-reflection on their own teaching relate to CRT? For this last empirical chapter, I conducted a multiple case study with four ethnic German teachers who work in one culturally and ethnically diverse high school in Berlin, using classroom video observations and post-observation interviews. In the final chapter (Chapter 6), I summarised the main findings of the systematic literature review and three empirical studies, and discuss their scientific and practical implications. This dissertation makes a significant contribution to the field of educational science to understanding culturally responsive teaching in terms of its measurement, focus on both beliefs and practices and the link between the two, and theoretical, practical, and future study implications. N2 - Die vorliegende Dissertation über Überzeugungen von Lehrern zur kulturellen Vielfalt und zum kultursensiblen Unterricht beinhaltet eine allgemeine Einführung (Kapitel 1), eine systematische Literaturübersicht (Kapitel 2), drei empirische Studien (Kapitel 3, 4 und 5) und endet mit einer allgemeinen Diskussion und dem Fazit (Kapitel 6). Der Schwerpunkt der Untersuchung sollte auf der Schaffung eines tieferen Verständnisses und Überzeugungen der Lehrer über kulturelle Vielfalt liegen und wie diese Überzeugungen mit den Unterrichtspraktiken zusammenhängen, die als kulturell ansprechend angesehen werden konnten oder nicht. In dieser Dissertation stützte ich mich auf Erkenntnisse aus theoretischen Perspektiven, die sich aus dem Bereich der Psychologie, insb. wie der sozialen Kognitionstheorie und gruppenübergreifenden Ideologien sowie aus dem Bereich der multikulturellen Bildungsarbeit und des kultursensiblen Unterrichts, ableiten. In Kapitel 1 stelle ich den Hintergrund dieser Dissertation mit kontextuellen Informationen über das deutsche Bildungssystem, den theoretischen Rahmen und die Forschungsziele der einzelnen Studien dar. In Kapitel 2 habe ich mit Lehrern in der Ausbildung eine systematische Review der bestehenden internationalen Studien zu Schulungen, die sich mit den Überzeugungen zur kulturellen Vielfalt befassen, durchgeführt. Insbesondere waren Ziele der systematischen Literaturrecherche: (1) die Beschreibung der Hauptkomponenten und kontextuellen Merkmale von Lehrerausbildungen, die sich an den Überzeugungen der kulturellen Vielfalt orientieren; (2) die Schulungseffekte zu berichten und (3) die methodischen Stärken und Schwächen dieser Studien zu beschreiben. Durch die Prüfung der Hauptkomponenten und kontextuellen Merkmale der Lehrerausbildung, der Auswirkungen auf die Überzeugungen von kulltureller Vielfalt sowie der methodischen Stärken und Schwächen dieser Studien in einer einzigen Untersuchung, habe ich einen ganzheitlichen Ansatz für diese drei Prozesse gewählt. Um die endgültige Kette von Studien (N = 36) zu untersuchen, benutzte ich einen deskriptiven und narrativen Ansatz, der sich hauptsächlich auf die Verwendung von Wörtern und Texten stützte, um die Ergebnisse der Synthese zusammenzufassen und zu erläutern. Die drei folgenden empirischen Studien zeigen Aspekte auf, inwieweit sich die Überzeugungen der Lehrer über kulturelle Vielfalt in reale Praktiken in Schulen umsetzen lassen. In Kapitel 3, zielte ich darauf ab, die Gültigkeit der Schulung bei kultureller Herausforderung auf den deutschen Kontext auszudehnen und die dimensionale Struktur der deutschen Version der Culturally Responsive Classroom Management Self-Efficacy Scale (CRCMSES; Siwatu, Putman, Starker-Glass, & Lewis, 2015) nachzuprüfen. Ich habe eine Exploratory und Contirmatory Factor Analysis durchgeführt, und um Korrelationen zwischen den Subskalen der CRCMSES und einem Maß für den Stress im Zusammenhang mit kultureller Vielfalt zu ermitteln. Die Daten (n = 504) für die erste empirische Studie (Kapitel 3) wurden im InTePP-Projekt (Inclusive Teaching Professionalization Panel) gesammelt, in dem die Kompetenzen und Überzeugungen der Lehrkräfte in Ausbildung an zwei Universitäten, der Universität Potsdam und der Universität Köln, longitudinal bewertet wurden. In der zweiten empirischen Studie, die Kapitel 4 bildet, liegt der Schwerpunkt auf den Praktiken der Lehrer, die den schulischen Ansätzen zur kulturellen Vielfalt ähneln. In dieser Studie bin ich zwei Forschungsfragen nachfegangen: (1a) Welche Arten von beschreibenden Normen zur kulturellen Vielfalt werden von Lehrern und Schülern mit und ohne Migrationshintergrund wahrgenommen und (1b) wie hoch ist ihr Grad der Kongruenz? Darüber hinaus interessierte mich auch, wie die Wahrnehmungen von Lehrern und Schülern über die Normen zur kulturellen Vielfalt mit Praktiken und Unterrichtsergebnessen in der physischen und virtuellen Schulumgebung zusammen hängen? Die Daten für die zweite empirische Studie (Kapitel 4) wurden zuvor in einem vom Landesprogramm "ProExzellenz" des Freistaates Thüringen geförderten Dissertationsprojekt von Doktor Maja Schachner gesammelt. Mit Hilfe einer gemischten Forschungsmethode habe ich eine Sekundäranalyse der Daten von Lehrern (n = 207) und Schülern (n = 1.644) an 22 Sekundarschulen im Südwesten Deutschlands durchgeführt. Weitere Datenquellen in dieser Studie basierten auf Bildern von Schulinnenräumen (Halle und Flure) und Wänden von Klassenzimmern der sechsten Klasse (n = 2,995) sowie Screenshots von jeder Schul-Website (n = 6,499). Kapitel 5 befasst sich mit der Frage, wie kulturell ansprechender Unterricht, mit den Überzeugungen von Lehrern zur kulturellen Vielfalt und Selbstreflexion über den eigenen Unterricht zusammenhängen. Genauer gesagt, habe ich in dieser Studie zwei Forschungsfragen angesprochen: (1) Wie verhält sich CRT zu den Überzeugungen der Lehrer über die Einbeziehung von Inhalten zur kulturellen Vielfalt in die täglichen Lehr- und Lernaktivitäten? Und (2) Inwiefern bezieht sich das Niveau der Selbstreflexion der Lehrer über ihren eigenen Unterricht auf CRT? Für dieses letzte empirische Kapitel habe ich eine mehrfache Fallstudie mit vier ethnischen Deutschlehrern durchgeführt, die an einem kulturell und ethnisch vielfältigen Gymnasium in Berlin arbeiten, wobei ich Videobeobachtungen im Klassenzimmer und Interviews nach der Beobachtung verwendete. Im letzten Kapitel (Kapitel 6) habe ich die wichtigsten Ergebnisse der systematischen Literaturrecherche und den drei empirischen Studien zusammengefasst und deren wissenschaftliche und praktische Auswirkungen diskutiert. Diese Dissertation leistet einen wichtigen Beitrag auf dem Gebiet der Erziehungswissenschaft zum Verständnis einer Schulung mit kultureller Herausforderung in Bezug auf ihre Messbarkeit, die sich konzentrieren auf beides: Überzeugungen und Praktiken und die Verbindung zwischen den beiden und auf theoretische, praktische und zukünftige Auswirkungen der Studie. Stichworte: kulturelle Vielfalt, Überzeugungen von Lehrern, kultursensibler Unterricht. KW - cultural diversity KW - kulturelle Vielfalt KW - teacher beliefs KW - culturally responsive teaching KW - Überzeugungen von Lehrern KW - kultursensibler Unterricht Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427763 ER - TY - RPRT A1 - Borck, Rainald A1 - Schrauth, Philipp T1 - Population density and urban air quality T2 - CEPA Discussion Papers N2 - We use panel data from Germany to analyze the effect of population density on urban air pollution (nitrogen oxides, particulate matter and ozone). To address unobserved heterogeneity and omitted variables, we present long difference/fixed effects estimates and instrumental variables estimates, using historical population and soil quality as instruments. Our preferred estimates imply that a one-standard deviation increase in population density increases air pollution by 3-12%. T3 - CEPA Discussion Papers - 8 KW - population density KW - air pollution Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427719 SN - 2628-653X IS - 8 ER - TY - RPRT A1 - Bruttel, Lisa Verena A1 - Nithammer, Juri A1 - Stolley, Florian T1 - ”Thanks in Advance” BT - The Negative Effect of a Polite Phrase on Compliance with a Request T2 - CEPA Discussion Papers N2 - This paper studies the effect of the commonly used phrase “thanks in advance” on compliance with a small request. In a controlled laboratory experiment we ask participants to give a detailed answer to an open question. The treatment variable is whether or not they see the phrase “thanks in advance.” Our participants react to the treatment by exerting less effort in answering the request even though they perceive the phrase as polite. T3 - CEPA Discussion Papers - 7 KW - compliance behavior KW - gratitude KW - reciprocity KW - experiment Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427706 SN - 2628-653X IS - 7 ER - TY - RPRT A1 - Caliendo, Marco A1 - Tübbicke, Stefan T1 - New Evidence on Long-Term Effects of Start-Up Subsidies BT - Matching Estimates and their Robustness T2 - CEPA Discussion Papers N2 - The German start-up subsidy (SUS) program for the unemployed has recently undergone a major make-over, altering its institutional setup, adding an additional layer of selection and leading to ambiguous predictions of the program’s effectiveness. Using propensity score matching (PSM) as our main empirical approach, we provide estimates of long-term effects of the post-reform subsidy on individual employment prospects and labor market earnings up to 40 months after entering the program. Our results suggest large and persistent long-term effects of the subsidy on employment probabilities and net earned income. These effects are larger than what was estimated for the pre-reform program. Extensive sensitivity analyses within the standard PSM framework reveal that the results are robust to different choices regarding the implementation of the weighting procedure and also with respect to deviations from the conditional independence assumption. As a further assessment of the results’ sensitivity, we go beyond the standard selection-on-observables approach and employ an instrumental variable setup using regional variation in the likelihood of receiving treatment. Here, we exploit the fact that the reform increased the discretionary power of local employment agencies in allocating active labor market policy funds, allowing us to obtain a measure of local preferences for SUS as the program of choice. The results based on this approach give rise to similar estimates. Thus, our results indicating that SUS are still an effective active labor market program after the reform do not appear to be driven by “hidden bias”. T3 - CEPA Discussion Papers - 6 KW - Start-Up Subsidies KW - Policy Reform KW - Matching KW - Instrumental Variables Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426798 SN - 2628-653X IS - 6 ER - TY - GEN A1 - Zeuschner, Steffen Peer A1 - Parpiiev, Tymur A1 - Pezeril, Thomas A1 - Hillion, Arnaud A1 - Dumesnil, Karine A1 - Anane, Abdelmadjid A1 - Pudell, Jan-Etienne A1 - Willig, Lisa A1 - Rössle, Matthias A1 - Herzog, Marc A1 - Reppert, Alexander von A1 - Bargheer, Matias T1 - Tracking picosecond strain pulses in heterostructures that exhibit giant magnetostriction T2 - Postprints der Universität Potsdam : Mathematisch-naturwissenschaftliche Reihe N2 - We combine ultrafast X-ray diffraction (UXRD) and time-resolved Magneto-Optical Kerr Effect (MOKE) measurements to monitor the strain pulses in laser-excited TbFe2/Nb heterostructures. Spatial separation of the Nb detection layer from the laser excitation region allows for a background-free characterization of the laser-generated strain pulses. We clearly observe symmetric bipolar strain pulses if the excited TbFe2 surface terminates the sample and a decomposition of the strain wavepacket into an asymmetric bipolar and a unipolar pulse, if a SiO2 glass capping layer covers the excited TbFe2 layer. The inverse magnetostriction of the temporally separated unipolar strain pulses in this sample leads to a MOKE signal that linearly depends on the strain pulse amplitude measured through UXRD. Linear chain model simulations accurately predict the timing and shape of UXRD and MOKE signals that are caused by the strain reflections from multiple interfaces in the heterostructure. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 706 KW - Heterostructures KW - Magnetooptical effects KW - Metal oxides KW - Crystal lattices KW - Transition metals KW - Magnetism KW - Ultrafast X-ray diffraction KW - Lasers KW - Bragg peak KW - Phonons Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-428457 SN - 1866-8372 IS - 706 ER - TY - JOUR A1 - Zeuschner, Steffen Peer A1 - Parpiiev, Tymur A1 - Pezeril, Thomas A1 - Hillion, Arnaud A1 - Dumesnil, Karine A1 - Anane, Abdelmadjid A1 - Pudell, Jan-Etienne A1 - Willig, Lisa A1 - Rössle, Matthias A1 - Herzog, Marc A1 - Reppert, Alexander von A1 - Bargheer, Matias T1 - Tracking picosecond strain pulses in heterostructures that exhibit giant magnetostriction JF - Structural Dynamics N2 - We combine ultrafast X-ray diffraction (UXRD) and time-resolved Magneto-Optical Kerr Effect (MOKE) measurements to monitor the strain pulses in laser-excited TbFe2/Nb heterostructures. Spatial separation of the Nb detection layer from the laser excitation region allows for a background-free characterization of the laser-generated strain pulses. We clearly observe symmetric bipolar strain pulses if the excited TbFe2 surface terminates the sample and a decomposition of the strain wavepacket into an asymmetric bipolar and a unipolar pulse, if a SiO2 glass capping layer covers the excited TbFe2 layer. The inverse magnetostriction of the temporally separated unipolar strain pulses in this sample leads to a MOKE signal that linearly depends on the strain pulse amplitude measured through UXRD. Linear chain model simulations accurately predict the timing and shape of UXRD and MOKE signals that are caused by the strain reflections from multiple interfaces in the heterostructure. KW - Heterostructures KW - Magnetooptical effects KW - Metal oxides KW - Crystal lattices KW - Transition metals KW - Magnetism KW - Ultrafast X-ray diffraction KW - Lasers KW - Bragg peak KW - Phonons Y1 - 2019 U6 - https://doi.org/10.1063/1.5084140 SN - 2329-7778 VL - 6 IS - 2 PB - AIP Publishing LLC CY - Melville, NY ER - TY - RPRT A1 - Bruttel, Lisa Verena T1 - Is There a Loyalty-Enhancing Effect of Retroactive Price-Reduction Schemes? T2 - CEPA Discussion Papers N2 - This paper presents an experiment on the effect of retroactive price-reduction schemes on buyers’ repeated purchase decisions. Such schemes promise buyers a reduced price for all units that are bought in a certain time frame if the total quantity that is purchased passes a given threshold. This study finds a loyalty-enhancing effect of retroactive price-reduction schemes only if the buyers ex-ante expected that entering into the scheme would maximize their monetary gain, but later learn that they should leave the scheme. Furthermore, the effect crucially hinges on the framing of the price reduction. T3 - CEPA Discussion Papers - 5 KW - rebate and discount KW - buyer behavior KW - risk aversion KW - loss aversion KW - regulation of dominant firms KW - experiment Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427688 SN - 2628-653X IS - 5 ER - TY - RPRT A1 - Audretsch, David B. A1 - Hafenstein, Marian A1 - Kritikos, Alexander A1 - Schiersch, Alexander T1 - Firm Size and Innovation in the Service Sector T2 - CEPA Discussion Papers N2 - A rich literature links knowledge inputs with innovative outputs. However, most of what is known is restricted to manufacturing. This paper analyzes whether the three aspects involving innovative activity - R&D; innovative output; and productivity - hold for knowledge intensive services. Combining the models of Crepon et al. (1998) and of Ackerberg et al. (2015), allows for causal interpretation of the relationship between innovation output and labor productivity. We find that knowledge intensive services benefit from innovation activities in the sense that these activities causally increase their labor productivity. Moreover, the firm size advantage found for manufacturing in previous studies nearly disappears for knowledge intensive services. T3 - CEPA Discussion Papers - 4 KW - MSMEs KW - R&D KW - Service Sector KW - Innovation KW - Productivity KW - Entrepreneurship Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427670 SN - 2628-653X IS - 4 ER - TY - RPRT A1 - Müller, Kai-Uwe A1 - Neumann, Michael A1 - Wrohlich, Katharina T1 - Labor supply under participation and hours constraints BT - An extended structural model for policy evaluations T2 - CEPA Discussion Papers N2 - The paper extends a static discrete-choice labor supply model by adding participation and hours constraints. We identify restrictions by survey information on the eligibility and search activities of individuals as well as actual and desired hours. This provides for a more robust identification of preferences and constraints. Both, preferences and restrictions are allowed to vary by and are related through observed and unobserved characteristics. We distinguish various restrictions mechanisms: labor demand rationing, working hours norms varying across occupations, and insufficient public childcare on the supply side of the market. The effect of these mechanisms is simulated by relaxing different constraints at a time. We apply the empirical frame- work to evaluate an in-work benefit for low-paid parents in the German institutional context. The benefit is supposed to increase work incentives for secondary earners. Based on the structural model we are able to disentangle behavioral reactions into the pure incentive effect and the limiting impact of constraints at the intensive and extensive margin. We find that the in-work benefit for parents substantially increases working hours of mothers of young children, especially when they have a low education. Simulating the effects of restrictions shows their substantial impact on employment of mothers with young children. T3 - CEPA Discussion Papers - 3 KW - labor supply KW - hours restrictions KW - involuntary unemployment KW - gender Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427656 SN - 2628-653X IS - 3 ER - TY - THES A1 - Solopow, Sergej T1 - Wavelength dependent demagnetization dynamics in Co2MnGa Heusler-alloy T1 - Wellenlängeabhängige Entmagnetisierungsdynamik in Co2MnGa Heusler-Legierung N2 - In dieser Arbeit haben wir ultraschnelle Entmagnetisierung an einer Heusler-Legierung untersucht. Es handelt sich um ein Halbmetall, das sich in einer ferromagnetischen Phase befindet. Die Besonderheit dieses Materials besteht im Aufbau einer Bandstruktur. Diese bildet Zustandsdichten, in der die Majoritätselektronen eine metallische Bänderbildung aufweisen und die Minoritätselektronen eine Bandlücke in der Nähe des Fermi-Niveaus aufweisen, das dem Aufbau eines Halbleiters entspricht. Mit Hilfe der Pump-Probe-Experimente haben wir zeitaufgelöste Messungen durchgeführt. Für das Pumpen wurden ultrakurze Laserpulse mit einer Pulsdauer von 100 fs benutzt. Wir haben dabei zwei verschiedene Wellenlängen mit 400 nm und 1240 nm benutzt, um den Effekt der Primäranregung und der Bandlücke in den Minoritätszuständen zu untersuchen. Dabei wurde zum ersten Mal OPA (Optical Parametrical Amplifier) für die Erzeugung der langwelligen Pulse an der FEMTOSPEX-Beamline getestet und erfolgreich bei den Experimenten verwendet. Wir haben Wellenlängen bedingte Unterschiede in der Entmagnetisierungszeit gemessen. Mit der Erhöhung der Photonenenergie ist der Prozess der Entmagnetisierung deutlich schneller als bei einer niedrigeren Photonenenergie. Wir verknüpften diese Ergebnisse mit der Existenz der Energielücke für Minoritätselektronen. Mit Hilfe lokaler Elliot-Yafet-Streuprozesse können die beobachteten Zeiten gut erklärt werden. Wir haben in dieser Arbeit auch eine neue Probe-Methode für die Magnetisierung angewandt und somit experimentell deren Effektivität, nämlich XMCD in Refletiongeometry, bestätigen können. Statische Experimente liefern somit deutliche Indizien dafür, dass eine magnetische von einer rein elektronischen Antwort des Systems getrennt werden kann. Unter der Voraussetzung, dass die Photonenenergie der Röntgenstrahlung auf die L3 Kante des entsprechenden Elements eingestellt, ein geeigneter Einfallswinkel gewählt und die zirkulare Polarisation fixiert wird, ist es möglich, diese Methode zur Analyse magnetischer und elektronischer Respons anzuwenden. N2 - In this work we investigated ultrafast demagnetization in a Heusler-alloy. This material belongs to the halfmetal and exists in a ferromagnetic phase. A special feature of investigated alloy is a structure of electronic bands. The last leads to the specific density of the states. Majority electrons form a metallic like structure while minority electrons form a gap near the Fermi-level, like in semiconductor. This particularity offers a good possibility to use this material as model-like structure and to make some proof of principles concerning demagnetization. Using pump-probe experiments we carried out time-resolved measurements to figure out the times of demagnetization. For the pumping we used ultrashort laser pulses with duration around 100 fs. Simultaneously we used two excitation regimes with two different wavelengths namely 400 nm and 1240 nm. Decreasing the energy of photons to the gap size of the minority electrons we explored the effect of the gap on the demagnetization dynamics. During this work we used for the first time OPA (Optical Parametrical Amplifier) for the generation of the laser irradiation in a long-wave regime. We tested it on the FETOSPEX-beamline in BASSYII electron storage ring. With this new technique we measured wavelength dependent demagnetization dynamics. We estimated that the demagnetization time is in a correlation with photon energy of the excitation pulse. Higher photon energy leads to the faster demagnetization in our material. We associate this result with the existence of the energy-gap for minority electrons and explained it with Elliot-Yaffet-scattering events. Additionally we applied new probe-method for magnetization state in this work and verified their effectivity. It is about the well-known XMCD (X-ray magnetic circular dichroism) which we adopted for the measurements in reflection geometry. Static experiments confirmed that the pure electronic dynamics can be separated from the magnetic one. We used photon energy fixed on the L3 of the corresponding elements with circular polarization. Appropriate incidence angel was estimated from static measurements. Using this probe method in dynamic measurements we explored electronic and magnetic dynamics in this alloy. KW - magnetizationdynamic KW - XMCD KW - Heusler-alloy KW - Magnetisierungsdynamik KW - XMCD KW - Heusler-Legierung Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427860 ER - TY - THES A1 - Vietze, Jana T1 - Social context as a resource for cultural belonging and adjustment BT - a developmental perspective on cultural minority youth in three european countries Y1 - 2019 ER - TY - GEN A1 - Choi, Youngeun A1 - Schmidt, Carsten A1 - Tinnefeld, Philip A1 - Bald, Ilko A1 - Rödiger, Stefan T1 - A new reporter design based on DNA origami nanostructures for quantification of short oligonucleotides using microbeads T2 - Postprints der Universität Potsdam : Mathematisch-naturwissenschaftliche Reihe N2 - The DNA origami technique has great potential for the development of brighter and more sensitive reporters for fluorescence based detection schemes such as a microbead-based assay in diagnostic applications. The nanostructures can be programmed to include multiple dye molecules to enhance the measured signal as well as multiple probe strands to increase the binding strength of the target oligonucleotide to these nanostructures. Here we present a proof-of-concept study to quantify short oligonucleotides by developing a novel DNA origami based reporter system, combined with planar microbead assays. Analysis of the assays using the VideoScan digital imaging platform showed DNA origami to be a more suitable reporter candidate for quantification of the target oligonucleotides at lower concentrations than a conventional reporter that consists of one dye molecule attached to a single stranded DNA. Efforts have been made to conduct multiplexed analysis of different targets as well as to enhance fluorescence signals obtained from the reporters. We therefore believe that the quantification of short oligonucleotides that exist in low copy numbers is achieved in a better way with the DNA origami nanostructures as reporters. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 705 KW - nucleic-acids KW - hybridization KW - microrna KW - flourescence KW - biomarkers KW - platform KW - particle KW - binding KW - array KW - gene Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-428271 SN - 1866-8372 IS - 705 ER - TY - JOUR A1 - Choi, Youngeun A1 - Schmidt, Carsten A1 - Tinnefeld, Philip A1 - Bald, Ilko A1 - Rödiger, Stefan T1 - A new reporter design based on DNA origami nanostructures for quantification of short oligonucleotides using microbeads JF - Scientific Reports N2 - The DNA origami technique has great potential for the development of brighter and more sensitive reporters for fluorescence based detection schemes such as a microbead-based assay in diagnostic applications. The nanostructures can be programmed to include multiple dye molecules to enhance the measured signal as well as multiple probe strands to increase the binding strength of the target oligonucleotide to these nanostructures. Here we present a proof-of-concept study to quantify short oligonucleotides by developing a novel DNA origami based reporter system, combined with planar microbead assays. Analysis of the assays using the VideoScan digital imaging platform showed DNA origami to be a more suitable reporter candidate for quantification of the target oligonucleotides at lower concentrations than a conventional reporter that consists of one dye molecule attached to a single stranded DNA. Efforts have been made to conduct multiplexed analysis of different targets as well as to enhance fluorescence signals obtained from the reporters. We therefore believe that the quantification of short oligonucleotides that exist in low copy numbers is achieved in a better way with the DNA origami nanostructures as reporters. KW - nucleic-acids KW - hybridization KW - microrna KW - flourescence KW - biomarkers KW - platform KW - particle KW - binding KW - array KW - gene Y1 - 2019 U6 - https://doi.org/10.1038/s41598-019-41136-x SN - 2045-2322 IS - 9 PB - Macmillan Publishers Limited CY - London ER - TY - GEN A1 - Hadzic, Miralem A1 - Eckstein, Max Lennart A1 - Schugardt, Monique T1 - The Impact of Sodium Bicarbonate on Performance in Response to Exercise Duration in Athletes BT - A Systematic Review T2 - Potsprints der Universität Potsdam : Humanwissenschaftliche Reihe N2 - According to recent literature sodium bicarbonate (NaHCO3) has been proposed as a performance enhancing aid by reducing acidosis during exercise. The aim of the current review is to investigate if the duration of exercise is an essential factor for the effect of NaHCO3. To collect the latest studies from electronic database of PubMed, study publication time was restricted from December 2006 to December 2016. The search was updated in July 2018. The studies were divided into exercise durations of > 4 or ≤ 4 minutes for easier comparability of their effects in different exercises. Only randomized controlled trials were included in this review. Of the 775 studies, 35 met the inclusion criteria. Study design, subjects, effects as well as outcome criteria were inconsistent throughout the studies. Seventeen of these studies reported performance enhancing effects after supplementing NaHCO3. Eleven of twenty studies with exercise duration of ≤ 4 minutes showed positive and four diverse results after supplementing NaHCO3. On the other hand six of fifteen studies with an exercise duration of >4 minutes showed performance enhancing and two studies showed diverse results. Consequently, the duration of exercise might be influential for inducing a performance enhancing effect when supplementing NaHCO3, but to which extent, remains unclear due to the inconsistencies in the study results. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 548 KW - Sodium bicarbonate KW - supplementation KW - acute KW - chronic KW - performance outcome Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-428078 SN - 1866-8364 IS - 548 ER - TY - JOUR A1 - Hadzic, Miralem A1 - Eckestein, Max Lennart A1 - Schugardt, Monique T1 - The Impact of Sodium Bicarbonate on Performance in Response to Exercise Duration in Athletes BT - A Systematic Review JF - Journal of sports science & medicine : JSSM N2 - According to recent literature sodium bicarbonate (NaHCO3) has been proposed as a performance enhancing aid by reducing acidosis during exercise. The aim of the current review is to investigate if the duration of exercise is an essential factor for the effect of NaHCO3. To collect the latest studies from electronic database of PubMed, study publication time was restricted from December 2006 to December 2016. The search was updated in July 2018. The studies were divided into exercise durations of > 4 or ≤ 4 minutes for easier comparability of their effects in different exercises. Only randomized controlled trials were included in this review. Of the 775 studies, 35 met the inclusion criteria. Study design, subjects, effects as well as outcome criteria were inconsistent throughout the studies. Seventeen of these studies reported performance enhancing effects after supplementing NaHCO3. Eleven of twenty studies with exercise duration of ≤ 4 minutes showed positive and four diverse results after supplementing NaHCO3. On the other hand six of fifteen studies with an exercise duration of >4 minutes showed performance enhancing and two studies showed diverse results. Consequently, the duration of exercise might be influential for inducing a performance enhancing effect when supplementing NaHCO3, but to which extent, remains unclear due to the inconsistencies in the study results. KW - Sodium bicarbonate KW - supplementation KW - acute KW - chronic KW - performance outcome Y1 - 2019 UR - https://www.jssm.org/hfabst.php?id=jssm-18-271.xml SN - 1303-2968 IS - 18 SP - 271 EP - 281 PB - Department of Sports Medicine, Medical Faculty of Uludag University CY - Bursa, Turkey ER - TY - RPRT A1 - Bruttel, Lisa Verena A1 - Stolley, Florian A1 - Utikal, Verena T1 - Getting a Yes BT - An Experiment on the Power of Asking T2 - CEPA Discussion Papers N2 - This paper studies how the request for a favor has to be devised in order to maximize its chance of success. We present results from a mini-dictator game, in which the recipient can send a free-form text message to the dictator before the latter decides. We find that putting effort into the message, writing in a humorous way and mentioning reasons why the money is needed pays off. Additionally, we find differences in the behavior of male and female dictators. Only men react positively to efficiency arguments, while only women react to messages that emphasize the dictator’s power and responsibility. T3 - CEPA Discussion Papers - 2 KW - dictator game KW - communication KW - inequality KW - text analysis KW - experiment Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427638 SN - 2628-653X IS - 2 ER - TY - GEN A1 - Grubic, Mira A1 - Wierzba, Marta T1 - Presupposition Accommodation of the German Additive Particle auch (= “too”) T2 - Postprints der Universität Potsdam Humanwissenschaftliche Reihe N2 - Presupposition triggers differ with respect to whether their presupposition is easily accommodatable. The presupposition of focus-sensitive additive particles like also or too is often classified as hard to accommodate, i.e., these triggers are infelicitous if their presupposition is not entailed by the immediate linguistic or non-linguistic context. We tested two competing accounts for the German additive particle auch concerning this requirement: First, that it requires a focus alternative to the whole proposition to be salient, and second, that it merely requires an alternative to the focused constituent (e.g., an individual) to be salient. We conducted two experiments involving felicity judgments as well as questions asking for the truth of the presupposition to be accommodated. Our results suggest that the latter account is too weak: mere previous mention of a potential alternative to the focused constituent is not enough to license the use of auch. However, our results also suggest that the former account is too strong: when an alternative of the focused constituent is prementioned and certain other accommodation-enhancing factors are present, the context does not have to entail the presupposed proposition. We tested the following two potentially accommodation-enhancing factors: First, whether the discourse can be construed to be from the perspective of the individual that the presupposition is about, and second, whether the presupposition is needed to establish coherence between the host sentence of the additive particle and the preceding context. The factor coherence was found to play a significant role. Our results thus corroborate the results of other researchers showing that discourse participants go to great lengths in order to identify a potential presupposition to accommodate, and we contribute to these results by showing that coherence is one of the factors that enhance accommodation. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 547 KW - alternatives KW - additive particles KW - presupposition KW - anaphoricity KW - accommodation KW - experimental data KW - German Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-428003 SN - 1866-8364 IS - 547 ER - TY - JOUR A1 - Grubic, Mira A1 - Wierzba, Marta T1 - Presupposition Accommodation of the German Additive Particle auch (= “too”) JF - Frontiers in Communication N2 - Presupposition triggers differ with respect to whether their presupposition is easily accommodatable. The presupposition of focus-sensitive additive particles like also or too is often classified as hard to accommodate, i.e., these triggers are infelicitous if their presupposition is not entailed by the immediate linguistic or non-linguistic context. We tested two competing accounts for the German additive particle auch concerning this requirement: First, that it requires a focus alternative to the whole proposition to be salient, and second, that it merely requires an alternative to the focused constituent (e.g., an individual) to be salient. We conducted two experiments involving felicity judgments as well as questions asking for the truth of the presupposition to be accommodated. Our results suggest that the latter account is too weak: mere previous mention of a potential alternative to the focused constituent is not enough to license the use of auch. However, our results also suggest that the former account is too strong: when an alternative of the focused constituent is prementioned and certain other accommodation-enhancing factors are present, the context does not have to entail the presupposed proposition. We tested the following two potentially accommodation-enhancing factors: First, whether the discourse can be construed to be from the perspective of the individual that the presupposition is about, and second, whether the presupposition is needed to establish coherence between the host sentence of the additive particle and the preceding context. The factor coherence was found to play a significant role. Our results thus corroborate the results of other researchers showing that discourse participants go to great lengths in order to identify a potential presupposition to accommodate, and we contribute to these results by showing that coherence is one of the factors that enhance accommodation. KW - alternatives KW - additive particles KW - presupposition KW - anaphoricity KW - accommodation KW - experimental data KW - German Y1 - 2019 U6 - https://doi.org/10.3389/fcomm.2019.00015 SN - 2297-900X VL - 4 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Pilz, Tobias A1 - Delgado, José Miguel Martins A1 - Voss, Sebastian A1 - Vormoor, Klaus Josef A1 - Francke, Till A1 - Cunha Costa, Alexandre A1 - Martins, Eduardo A1 - Bronstert, Axel T1 - Seasonal drought prediction for semiarid northeast Brazil BT - what is the added value of a process-based hydrological model? JF - Hydrology and Earth System Sciences N2 - The semiarid northeast of Brazil is one of the most densely populated dryland regions in the world and recurrently affected by severe droughts. Thus, reliable seasonal forecasts of streamflow and reservoir storage are of high value for water managers. Such forecasts can be generated by applying either hydrological models representing underlying processes or statistical relationships exploiting correlations among meteorological and hydrological variables. This work evaluates and compares the performances of seasonal reservoir storage forecasts derived by a process-based hydrological model and a statistical approach. Driven by observations, both models achieve similar simulation accuracies. In a hindcast experiment, however, the accuracy of estimating regional reservoir storages was considerably lower using the process-based hydrological model, whereas the resolution and reliability of drought event predictions were similar by both approaches. Further investigations regarding the deficiencies of the process-based model revealed a significant influence of antecedent wetness conditions and a higher sensitivity of model prediction performance to rainfall forecast quality. Within the scope of this study, the statistical model proved to be the more straightforward approach for predictions of reservoir level and drought events at regionally and monthly aggregated scales. However, for forecasts at finer scales of space and time or for the investigation of underlying processes, the costly initialisation and application of a process-based model can be worthwhile. Furthermore, the application of innovative data products, such as remote sensing data, and operational model correction methods, like data assimilation, may allow for an enhanced exploitation of the advanced capabilities of process-based hydrological models. KW - Water Availability KW - Uncertainty Processor KW - Forecasting Framework KW - Sediment Transport KW - Reservoir Networks KW - Jaguaribe Basin KW - Climate KW - Precipitation KW - Nordeste KW - Connectivity Y1 - 2019 U6 - https://doi.org/10.5194/hess-23-1951-2019 SN - 1027-5606 SN - 1607-7938 VL - 23 SP - 1951 EP - 1971 PB - Copernicus Publications CY - Göttingen ER - TY - GEN A1 - Pilz, Tobias A1 - Delgado, José Miguel Martins A1 - Voss, Sebastian A1 - Vormoor, Klaus Josef A1 - Francke, Till A1 - Cunha Costa, Alexandre A1 - Martins, Eduardo A1 - Bronstert, Axel T1 - Seasonal drought prediction for semiarid northeast Brazil BT - what is the added value of a process-based hydrological model? T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - The semiarid northeast of Brazil is one of the most densely populated dryland regions in the world and recurrently affected by severe droughts. Thus, reliable seasonal forecasts of streamflow and reservoir storage are of high value for water managers. Such forecasts can be generated by applying either hydrological models representing underlying processes or statistical relationships exploiting correlations among meteorological and hydrological variables. This work evaluates and compares the performances of seasonal reservoir storage forecasts derived by a process-based hydrological model and a statistical approach. Driven by observations, both models achieve similar simulation accuracies. In a hindcast experiment, however, the accuracy of estimating regional reservoir storages was considerably lower using the process-based hydrological model, whereas the resolution and reliability of drought event predictions were similar by both approaches. Further investigations regarding the deficiencies of the process-based model revealed a significant influence of antecedent wetness conditions and a higher sensitivity of model prediction performance to rainfall forecast quality. Within the scope of this study, the statistical model proved to be the more straightforward approach for predictions of reservoir level and drought events at regionally and monthly aggregated scales. However, for forecasts at finer scales of space and time or for the investigation of underlying processes, the costly initialisation and application of a process-based model can be worthwhile. Furthermore, the application of innovative data products, such as remote sensing data, and operational model correction methods, like data assimilation, may allow for an enhanced exploitation of the advanced capabilities of process-based hydrological models. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 702 KW - Water Availability KW - Uncertainty Processor KW - Forecasting Framework KW - Sediment Transport KW - Reservoir Networks KW - Jaguaribe Basin KW - Climate KW - Precipitation KW - Nordeste KW - Connectivity Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427950 SN - 1866-8372 IS - 702 ER - TY - THES A1 - Weber, Marie-Christin T1 - Performance Enhancing Strategies in Different Negotiation Phases N2 - The present dissertation investigates profit-maximizing behavior in different phases of the negotiation process. Over the last decades, research dealt in detail with behavior of negotiation actors with the aim of identifying performance enhancing factors. The majority of those studies focused on behavior within the main negotiation phase. This work, however, considers phases which are, so far, underrepresented in research but show an impact on the negotiation process and outcome. Those phases are the pre-negotiation, the first offer, and the main negotiation phase which is further divided by breaks into several rounds. Within these phases, traits of behavior are analyzed that can be used strategically in order to impact the negotiation outcome. The dissertation contains three papers, each one dealing with a specific strategy within one phase. The first paper investigates communication behavior in the pre-negotiation phase. Content analysis of a negotiation experiment shows that the employment of positive communication elements such as the generation of enthusiasm for an upcoming project results in an increase of agreements on entering a negotiation and also leads to a higher willingness to make concessions. The second paper explores the impact of a semantic first anchor, which does not contain a specific number but only gives a numerical direction, on the opponent’s concession behavior and the final outcome. By means of two scenario-based questionnaires and a negotiation experiment it is demonstrated that semantic offers reveal an anchoring effect and lead to better negotiation outcomes. The third paper deals with the introduction of breaks and their effect on the following negotiation process. Therefore, content and outcome of another negotiation experiment are investigated. The analysis shows that breaks evoke a dominant impression but can negatively impact the atmosphere and thereby also the outcome. Finally, the gathered insights are brought together and discussed. The dissertation closes with implications for practice, limitations of the work, and ideas for future research. N2 - Die Autorin untersucht gewinnmaximierendes Verhalten in verschiedenen Phasen des Verhandlungsprozesses. Bereits seit einigen Jahrzehnten setzt sich die Forschung eingehend mit dem Verhalten von Akteuren in Verhandlungen auseinander und versucht, Faktoren, welche die Performance beeinflussen, zu identifizieren. Die Mehrheit der Studien fokussiert sich dabei auf Verhaltensweisen innerhalb der Hauptphase einer Verhandlung. Die Abhandlung betrachtet hingegen Phasen, die bislang in der Forschung unterrepräsentiert sind, jedoch einen Einfluss auf den Verhandlungsverlauf und das Verhandlungsergebnis aufweisen. Diese Phasen sind die Vorverhandlungsphase, die erste Angebotsabgabe und der damit einhergehende Übergang in die Hauptverhandlungsphase und Pausen, welche die Hauptverhandlung in mehrere Runden einteilen. Innerhalb dieser Phasen werden Verhaltensweisen untersucht und analysiert, die strategisch eingesetzt werden können, um das individuelle Verhandlungsergebnis zu beeinflussen. Die Dissertation umfasst drei empirische Artikel, die sich jeweils mit einer konkreten Strategie innerhalb einer Phase befassen. Im ersten Paper wird das Kommunikationsverhalten in der Vorverhandlungsphase untersucht. Dabei wird mittels eines Verhandlungsexperiments und anschließender Inhaltsanalyse der Gesprächsprotokolle herausgestellt, dass die Verwendung positiver Kommunikationselemente wie das Erzeugen von Enthusiasmus für ein anstehendes Projekt, zu einem prozentualen Anstieg an Einigungen für den Verhandlungseintritt und einer höheren Konzessionsbereitschaft führt. Das zweite Paper untersucht die Wirkung eines semantischen ersten Angebots, welches keine spezifische Zahl beinhaltet, sondern nur eine numerische Richtung vorgibt, auf das Konzessionsverhalten der Gegenseite und das Verhandlungsergebnis. Anhand zweier Szenario-basierter Befragungen und einem Verhandlungsexperiment wird verdeutlicht, dass semantische Angebote eine Ankerwirkung aufweisen und sogar zu besseren Verhandlungsergebnissen führen. Das dritte Paper betrachtet das Setzen von Pausen und deren Auswirkung auf den weiteren Verhandlungsverlauf. Hierzu werden die Gesprächsinhalte sowie die Ergebnisse eines weiteren Verhandlungsexperiments untersucht. Die Analyse zeigt, dass Pausen zwar eine dominante Wirkung haben, sich jedoch negativ auf die Stimmung innerhalb der Verhandlung und somit auch auf das Verhandlungsergebnis auswirken können. Abschließend werden die gewonnen Erkenntnisse zusammengetragen und diskutiert. Die Dissertation schließt mit Implikationen für die Praxis, Limitationen der Arbeit, sowie einem Forschungsausblick ab. Y1 - 2019 SN - 978-3-339-10946-0 PB - Kovac CY - Hamburg ER - TY - GEN A1 - Abbas, Ioana M. A1 - Vranic, Marija A1 - Hoffmann, Holger A1 - El-Khatib, Ahmed H. A1 - Montes-Bayón, María A1 - Möller, Heiko Michael A1 - Weller, Michael G. T1 - Investigations of the Copper Peptide Hepcidin-25 by LC-MS/MS and NMR⁺ T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Hepcidin-25 was identified as themain iron regulator in the human body, and it by binds to the sole iron-exporter ferroportin. Studies showed that the N-terminus of hepcidin is responsible for this interaction, the same N-terminus that encompasses a small copper(II) binding site known as the ATCUN (amino-terminal Cu(II)- and Ni(II)-binding) motif. Interestingly, this copper-binding property is largely ignored in most papers dealing with hepcidin-25. In this context, detailed investigations of the complex formed between hepcidin-25 and copper could reveal insight into its biological role. The present work focuses on metal-bound hepcidin-25 that can be considered the biologically active form. The first part is devoted to the reversed-phase chromatographic separation of copper-bound and copper-free hepcidin-25 achieved by applying basic mobile phases containing 0.1% ammonia. Further, mass spectrometry (tandemmass spectrometry (MS/MS), high-resolutionmass spectrometry (HRMS)) and nuclear magnetic resonance (NMR) spectroscopy were employed to characterize the copper-peptide. Lastly, a three-dimensional (3D)model of hepcidin-25with bound copper(II) is presented. The identification of metal complexes and potential isoforms and isomers, from which the latter usually are left undetected by mass spectrometry, led to the conclusion that complementary analytical methods are needed to characterize a peptide calibrant or referencematerial comprehensively. Quantitative nuclear magnetic resonance (qNMR), inductively-coupled plasma mass spectrometry (ICP-MS), ion-mobility spectrometry (IMS) and chiral amino acid analysis (AAA) should be considered among others. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 701 KW - hepcidin-25 KW - copper KW - nickel KW - copper complex KW - ATCUN motif KW - metal complex KW - MS KW - NMR structure KW - metal peptide KW - metalloprotein KW - metallopeptide KW - isomerization KW - racemization KW - purity KW - reference material Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427926 SN - 1866-8372 IS - 701 ER - TY - GEN A1 - Spiekermann, Georg A1 - Harder, M. A1 - Gilmore, Keith A1 - Zalden, Peter A1 - Sahle, Christoph J. A1 - Petitgirard, Sylvain A1 - Wilke, Max A1 - Biedermann, Nicole A1 - Weis, Thomas A1 - Morgenroth, Wolfgang A1 - Tse, John S. A1 - Kulik, E. A1 - Nishiyama, Norimasa A1 - Yavaş, Hasan A1 - Sternemann, Christian T1 - Persistent Octahedral Coordination in Amorphous GeO₂ Up to 100 GPa by Kβ'' X-Ray Emission Spectroscopy T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - We measure valence-to-core x-ray emission spectra of compressed crystalline GeO₂ up to 56 GPa and of amorphous GeO₂ up to 100 GPa. In a novel approach, we extract the Ge coordination number and mean Ge-O distances from the emission energy and the intensity of the Kβ'' emission line. The spectra of high-pressure polymorphs are calculated using the Bethe-Salpeter equation. Trends observed in the experimental and calculated spectra are found to match only when utilizing an octahedral model. The results reveal persistent octahedral Ge coordination with increasing distortion, similar to the compaction mechanism in the sequence of octahedrally coordinated crystalline GeO₂ high-pressure polymorphs. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 699 KW - rutile-type KW - glass KW - crystalline KW - pressures KW - complexes KW - silicon KW - oxygen KW - SIO₂ KW - MO KW - CU Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427755 SN - 1866-8372 IS - 699 ER - TY - JOUR A1 - Spiekermann, Georg A1 - Harder, M. A1 - Gilmore, Keith A1 - Zalden, Peter A1 - Sahle, Christoph J. A1 - Petitgirard, Sylvain A1 - Wilke, Max A1 - Biedermann, Nicole A1 - Weis, Thomas A1 - Morgenroth, Wolfgang A1 - Tse, John S. A1 - Kulik, E. A1 - Nishiyama, Norimasa A1 - Yavaş, Hasan A1 - Sternemann, Christian T1 - Persistent Octahedral Coordination in Amorphous GeO₂ Up to 100 GPa by Kβ'' X-Ray Emission Spectroscopy JF - Physical Review X N2 - We measure valence-to-core x-ray emission spectra of compressed crystalline GeO₂ up to 56 GPa and of amorphous GeO₂ up to 100 GPa. In a novel approach, we extract the Ge coordination number and mean Ge-O distances from the emission energy and the intensity of the Kβ'' emission line. The spectra of high-pressure polymorphs are calculated using the Bethe-Salpeter equation. Trends observed in the experimental and calculated spectra are found to match only when utilizing an octahedral model. The results reveal persistent octahedral Ge coordination with increasing distortion, similar to the compaction mechanism in the sequence of octahedrally coordinated crystalline GeO₂ high-pressure polymorphs. KW - rutile-type KW - glass KW - crystalline KW - pressures KW - complexes KW - silicon KW - oxygen KW - SIO₂ KW - MO KW - CU Y1 - 2019 U6 - https://doi.org/10.1103/PhysRevX.9.011025 SN - 2469-9926 SN - 0556-2791 SN - 1050-2947 SN - 1094-1622 VL - 9 IS - 1 PB - American Physical Society by the American Institute of Physics CY - Melville, NY ER - TY - THES A1 - Farhan, Muhammad T1 - Multifunctional reprogrammable actuators based on polymer networks with crystallizable segments N2 - Soft polymeric materials, which can change their shape reversibly in response to external stimuli, can serve as actuating components in robotic systems. Besides electroactive polymers (EAP), hydrogels and liquid crystalline elastomers (LCE), crosslinked crystallizable shape-memory polymers networks have been introduced recently as reprogrammable thermo-reversible actuators. The integration of additional functions in such materials will lead to multifunctional polymeric actuators, which meet the complex requirements of modern robotic applications. The primary aim of this thesis was to achieve multifunctional reprogrammable thermo-reversible actuators based on thermoplastic polymers. Here, three different actuators providing additional functionalities such as surface modification capability (i), self-healing capability (ii) or a tailorable non-response function enabling noncontinuous multi-step motions (iii) were realized. At first, it was hypothesized that surface modifiable polymeric actuators (i) can be achieved by crosslinking of crystallizable thermoplastic terpolymers having reactive moieties, where subsequent thermomechanical programming enables reversible actuations while the sustained reactive groups allow post surface modification. For the second actuator type (ii) it was hypothesized that self-healing during reprogramming of polymeric actuators prepared by crosslinking of crystallizable linear homopolymers, can be achieved by adjusting the amount of freely interpenetrating extractable polymer moieties. Finally, it was hypothesized that thermo-reversible actuators providing a non-response function (iii) and thus enable multistep motions upon continuous normal stimulation, can be achieved by a crosslinked blend of two thermoplastic polymers with co-continuous morphology having a well-separated melting and crystallization transitions. In addition, these actuators can be physically reprogrammed by heating above all melting transitions to provide a different actuating shape. In this study, surface functionalizable actuators were realized from crosslinked poly[(ethylene)-co-(ethyl acrylate)-co-(maleic anhydride)] (cPEEAMA) based networks. Here crystallizable polyethylene (PE) segments should serve as actuation segments, ethyl acrylate (EA) provides elasticity to the system required for deformation, while reactive maleic anhydride (MA) will be used as chemically modifiable entities for post surface modification. Networks with varied crosslink density were prepared and its effect on thermomechanical properties as well as actuation performance was analyzed. Cyclic thermomechanical experiments were employed to investigate the actuation capability, which revealed a reversible actuation (ε׳rev) between 5 and 15%. Fourier-transform infrared spectroscopy (FTIR) measurements confirmed that MA groups were sustained at the sample surface after processing and programming, which could be modified by reaction with ethylene diamine. Such amine functionalization allows the attachment of bioactive molecules to the actuator surface, which might provide a route to actuating substrates for biotechnology. Self-healable actuating materials were realized by poly(ε-caprolactone) (PCL) polymer networks with extractable linear PCL fractions of 5 to 60 wt%. A detailed evaluation of the actuation capabilities by cyclic experiments revealed the highest reversible change in strain of Δε = 24% for the cPCL network with 30 wt% of linear polymer. The thermal treatment of damaged samples resulted in the healing of the network when heated to 80 °C. Here a linear polymer fraction ≥ 30 wt% was necessary to achieve a self-healing efficiency of ≥ 50%. The application of such high temperatures erases the programmed actuator shape and at the same time allows to reprogram a new actuating shape. Such sustainable actuators with self-healing function are of great interest for future robotic devices. Afore mentioned actuators operate continuously between two shapes and their movements can only be interrupted when the temperature is stopped. To overcome this limitation, noncontinuously responding actuators enabling multi-step actuation were realized from crosslinked blend networks prepared from PCL and poly[(ethylene)-co-(vinyl acetate)] (PEVA). These polymers (PCL and PEVA) were selected due to their immiscible character, where crystallizable PE and PCL segments provide two different actuation units, while vinyl acetate (VA) segment enabled sufficient elasticity of the system. A gap of 20 K in the melting and crystallization temperature of PE and PCL was achieved by selecting PEVA with 5 wt% VA content (cPCL-PEVA5) providing a co-continuous phase morphology. Cyclic thermomechanical investigations were employed to investigate noncontinuous actuation, which revealed a high Δε = 25% with a similar contribution from PCL and PE actuation units with a non-response region in the temperature range from 50 to 71 °C in heating step and 30 to 60 °C in cooling step. The actuation related to PCL part changed from 13 to 2% by altering the heating and cooling rates from 3 to 10 K·min-1. Free-standing reversible noncontinuous actuation was realized by rotating demonstrator which exhibits reversible angle change in a custom-made setup. For this purpose, cPCL-PEVA5 stripe was programmed by twisting and reversible rotational actuation was realized from 0 to 180° while pausing in the 90° position during non-response. These blends can be physically programmed to perform reversible noncontinuous actuations, while the programmed geometry can be erased by heating it to temperature above all melting transitions. By physically reprogramming of the material various different actuation modes can be obtained. Such a noncontinuous actuator would be relevant for designing interruptive actuating soft robots at continuous trigger signals. N2 - Weiche, Polymer-basierte Materialien, die ihre Form in Abhängigkeit eines äußeren Reizes reversibel ändern können, können als bewegliche Bauteile in Robotern Verwendung finden. Neben elektro-aktiven Polymeren, Hydrogelen und flüssigkristallinen Elastomeren wurden vernetzte kristallisierbare Polymernetzwerke mit Formgedächtnisfunktion als reprogrammierbare, temperatur-abhängige Aktuatoren beschrieben. Das Integrieren von zusätzlichen Funktionen in derartige Materialien führt zu neuen multifunktionalen Aktuatoren, die in der Lage sein sollten die immer komplexer werdenden Anforderungen an weiche Roboter in zukünftigen Anwendungsfelder erfüllen zu können. Das Ziel dieser Arbeit war es multifunktionale, reprogrammierbare thermo-sensitive Aktuatoren auf Basis von thermoplastischen Polymeren zu realisieren. Hierfür wurden drei unterschiedliche multifunktionale Aktuator-Typen mit zusätzlichen Funktionen hergestellt und untersucht. Als zusätzliche Funktionen wurden: (i) die Möglichkeit der Oberflächenmodifikation, (ii) Selbstheilung der Materialien und (iii) einstellbare diskontinuierliche Bewegungen erforscht. Zu Beginn wurden Aktuatoren betrachtet, die eine modifizierbaren Oberfläche (i) aufweisen. Durch Vernetzung von kristallisierbaren Thermoplasten, die reaktive, funktionelle Gruppen beinhalten wurden entsprechende Materialien hergestellt. Während die reversible Bewegungsinformation über eine thermomechanische Behandlung im Material gespeichert wird, erfolgt die Funktionalisierung mittels chemischer Behandlung an der Oberfläche nachträglich. Der zweite Ansatz (ii) verfolgt das Ziel den Aktuator mit selbstheilende Eigenschaften auszustatten. Dabei soll über freie, unvernetzte lineare Polymerketten innerhalb des Polymernetzwerkes, während der Reprogrammierungsphase eine Reparatur von zuvor eingebrachten oder entstandenen Schäden erfolgen. Im letzten Teilprojekt soll ein diskontinuierliches Bewegungsprofil mit einem polymeren Aktuator umgesetzt werden. Hierfür wird ein kovalent vernetztes Copolymernetzwerk aus einer Mischung von zwei Thermoplasten mit deutlich getrennten thermischen Übergängen (Schmelzbereich und Kristallisationsbereich) hergestellt, welches bei kontinuierlichem Heizen und Kühlen eine pausierend Bewegung ausführt z.B. eine unterbrochene Längenänderung (oder auch anderen Bewegung). Eine Gemeinsamkeit für alle untersuchten Materialien ist deren Fähigkeit zur Reprogrammierung in unterschiedliche Bewegungsformen über ein rein physikalisches (thermomechanisches) Verfahren wobei alle kristallinen Bereiche aufgeschmolzen werden. Im Rahmen der Oberflächen-modifizierbaren Aktuatoren wurden Netzwerke aus dem Terpolymer, Poly[(ethylen)-co-(ethylacrylat)-co-(maleinsäureanhydrid)] hergestellt. Der kristallisierbare Anteil von Polyethylen (PE) dient als Aktuator-Domäne, Ethylacrylat unterstützt die Deformierbarkeit des Polymernetzwerkes und Maleinsäureanhydrid ermöglicht die nachträgliche Funktionalisierung an der Oberfläche. Netzwerke mit unterschiedlichen Vernetzungsdichten wurden bezüglich ihrer thermomechanischen Eigenschaften und ihrer Aktuator-Performance untersucht und zeigten in zyklischen Heiz-Kühl-Experimenten reversible Formänderungen zwischen 5 und 15%. Messungen mit dem Fourier-Transform-Infrarotspektrometer zeigen die Beständigkeit der Maleinsäureanhydrid-Gruppen auch nach der Vernetzung und der thermomechanischen Behandlung. Durch chemische Reaktion der Maleinsäureanhydrid Gruppen mit Ethylendiamin wurden Amin-Funktionalitäten an der Oberfläche etabliert. Diese ermöglichen die kovalente Anknüpfung von bioaktiven Molekülen auf dem Aktuator, was insbesondere für Anwendungen in der Biotechnologie relevant sein könnte. Selbstheilende Aktuatoren wurden am Beispiel von Netzwerken aus Poly(ε-Caprolacton) (PCL) erforscht. Hier wurden Materialien mit unterschiedliche Anteilen an extrahierbaren Polymerketten von bis zu 60 Gew.-% hergestellt und untersucht. Diese Untersuchungen zeigten, dass die höchsten reversiblen Bewegungsänderungen für Netzwerke mit ein Anteil von 30 Gew.-% an unvernetzten PCL erzielt werden können. Ein Erwärmen von beschädigten Probenkörpern auf 80 °C ermöglichte das „Heilen“, wobei ein Anteil von ≥ 30 Gew.-% an freien Polymerketten nötig ist um hohe Heilungs-Effizienz zu erreichen. Die Behandlung bei 80 °C erlaubt neben dem Schließen von Beschädigungen auch die Programmierung einer anderen Bewegungsform des Prüfkörpers. Dieser Typ von nachhaltigen Aktuatoren könnte zukünftig neuartige Technologien ermöglichen. Alle vorher genannten Beispiele haben gemeinsam, dass sie ihre Form zwischen zwei definierten Zuständen über eine gleichmäßige Bewegung ändern bzw. diese Bewegung nur unterbrochen werden kann, wenn die Temperatur angehalten wird. Um diese Einschränkung zu überwinden wurden eine Mischung aus zwei Polymer-Systeme, PCL und Poly[(Ethylen)-co-(Vinylacetat)] (PEVA) hergestellt und vernetzt. Durch ihre geringe Mischbarkeit phasenseparieren PCL und PEVA und es entsteht ein Material mit co-kontinuierlicher Morphologie. Die entsprechenden Schmelz- und Kristallisationstemperaturen der beiden Komponenten PCL und PEVA weisen eine Differenz von gut 20 °C auf. In zyklischen Heiz-Kühl-Experimenten konnten reversible Formänderungen von bis zu 25% erzielt werden, wobei die Beiträge der beiden kristallisierbaren PCL und PEVA Domänen ähnlich sind. Während des Heizens findet im Temperaturbereich zwischen 50 und 71 °C keine Formänderung statt und gleichermaßen beobachtet man beim Kühlen zwischen 60 und 30 °C keine Bewegung. Diese Beobachtung lässt sich gut durch den Abstand der Schmelztemperaturen der beiden Polymere PCL und PEVA erklären. Das Aufschmelzen und die Kristallisation von Polymeren sind abhängig von den angewendeten Heiz-/Kühlraten. Insbesondere für den PCL-Anteil im Material kann durch die Änderung der Heiz-/Kühlraten sowohl die mehrstufige Bewegungsperformance als auch der Temperaturbereich in dem keine Bewegung stattfindet beeinflusst werden. Um die Vielfältigkeit der Formänderung von Aktuatoren zu demonstrieren wurden Probenkörper auch verdrillt und deren reversible Rotation untersucht, wobei eine der Längenänderung vergleichbare Performance beobachtet wurde. Derartige Aktuatoren, die eine Unterbrechung in ihrer Bewegung aufweisen, bei einem kontinuierlichen Steuerimpulses, könnten Anwendung im Bereich der weichen Robotik finden in denen diskontinuierliche Bewegungsabläufe gefordert sind. KW - shape-memory polymers KW - soft actuators KW - thermoplastic polymers KW - Formgedächtnispolymere KW - weiche Aktuatoren KW - thermoplastischen Polymere Y1 - 2019 ER - TY - THES A1 - Lefebvre, Marie G. T1 - Two stages of skarn formation - two tin enrichments T1 - Zwei Stufen der Skarn-Bildung - zwei Phasen der Zinnmobilisierung BT - the Hämmerlein polymetallic skarn deposit, western Erzgebirge, Germany BT - die polymetallische Skarnablagerung Hämmerlein, West Erzgebirge, Deutschland N2 - Skarn deposits are found on every continents and were formed at different times from Precambrian to Tertiary. Typically, the formation of a skarn is induced by a granitic intrusion in carbonates-rich sedimentary rocks. During contact metamorphism, fluids derived from the granite interact with the sedimentary host rocks, which results in the formation of calc-silicate minerals at the expense of carbonates. Those newly formed minerals generally develop in a metamorphic zoned aureole with garnet in the proximal and pyroxene in the distal zone. Ore elements contained in magmatic fluids are precipitated due to the change in fluid composition. The temperature decrease of the entire system, due to the cooling of magmatic fluids and the entering of meteoric water, allows retrogression of some prograde minerals. The Hämmerlein skarn deposit has a multi-stage history with a skarn formation during regional metamorphism and a retrogression of primary skarn minerals during the granitic intrusion. Tin was mobilized during both events. The 340 Ma old tin-bearing skarn minerals show that tin was present in sediments before the granite intrusion, and that the first Sn enrichment occurred during the skarn formation by regional metamorphism fluids. In a second step at ca. 320 Ma, tin-bearing fluids were produced with the intrusion of the Eibenstock granite. Tin, which has been added by the granite and remobilized from skarn calc-silicates, precipitated as cassiterite. Compared to clay or marl, the skarn is enriched in Sn, W, In, Zn, and Cu. These metals have been supplied during both regional metamorphism and granite emplacement. In addition, the several isotopic and chemical data of skarn samples show that the granite selectively added elements such as Sn, and that there was no visible granitic contribution to the sedimentary signature of the skarn The example of Hämmerlein shows that it is possible to form a tin-rich skarn without associated granite when tin has already been transported from tin-bearing sediments during regional metamorphism by aqueous metamorphic fluids. These skarns are economically not interesting if tin is only contained in the skarn minerals. Later alteration of the skarn (the heat and fluid source is not necessarily a granite), however, can lead to the formation of secondary cassiterite (SnO2), with which the skarn can become economically highly interesting. N2 - Skarn-Lagerstätten befinden sich auf allen Kontinenten und wurden zu unterschiedlichen Zeiten vom Präkambrium bis zum Tertiär gebildet. Typischerweise wird die Bildung eines Skarns durch die Intrusion eines Granits in karbonatreiche Sedimentgesteine induziert. Während der Kontaktmetamorphose reagieren die Fluide aus dem Granit mit dem sedimentären Wirtgestein, was zur Bildung von Kalksilikaten auf Kosten von Karbonaten führt. Diese neu gebildeten Minerale entwickeln sich im Allgemeinen in einer metamorph zonierten Aureole mit Granat im proximalen und Pyroxen im distalen Bereich. Erzelemente die in magmatischen Fluiden enthalten sind werden aufgrund der veränderten Fluidzusammensetzung ausgefällt. Die Temperaturabsenkung des gesamten Systems, hervorgerufen durch die Abkühlung von magmatischen Fluiden sowie durch das Eindringen meteorischen Wassers, führen zu teilweisen oder vollständigen Umwandlung prograder Minerale. Die Skarn-Lagerstätte Hämmerlein hat eine mehrstufige Geschichte mit Skarnsbildung während der regionalen Metamorphose und Retrogression der primären Skarn-Minerale während der Intrusion von Graniten. Zinn wurde während beiden Ereignissen mobilisiert. Die 340 Ma alten zinnhaltigen Skarnminerale zeigen, dass Zinn in Sedimenten bereits vor dem Graniteintrag vorhanden war, und dass die erste Sn-Anreicherung während der Bildung des Skarns durch Fluide der Regionalmetamorphose stattfand. In einem zweiten Schritt um 320 Ma wurden Zinn-haltige Fluide durch die Intrusion des Eibenstockgranits freigesetzt. Diese Fluide überprägten den Skarn. Das freisetzen und das neu zugefügte Zinn ist in Kassiterit gebunden und führten dem System zusätzliches Zinn zu, wobei Zinn aus den Skarn-Kalksilikaten remobilisiert wurde. Im Vergleich zu Tonstein oder Mergel sind die Skarn mit Sn, W, In, Zn, und Cu angereichet. Diese Metalle sind während der Regionalmetamorphose und der Granitplatznahme zu unterschiedlichen Teilen zugeführt worden. Darüber hinaus zeigen die verschiedenen isotopen und chemischen Daten der Skarn-Proben, dass der Granit selektiv einige Elemente wie Sn hinzugefügt, und dass es keinen sichtbar granitischen Beitrag zur sedimentären Signatur des Skarns gab. Das Beispiel Hämmerlein zeigt, dass es möglich ist einen zinnreichen Skarn ohne zugehörigen Granit zu bilden, wenn Zinn von zinnhaltigen Sedimenten während einer Regionalmetamorphose mit wässrigen metamorphen Fluiden transportiert worden ist. Diese Skarne sind wirtschaftlich uninterssant wenn das Zinn nur in den Skarn-Mineralen enthalten ist. Spätere Umwandlung des Skarns (die Quelle der Wärme und Fluiden ist nicht unbedingt ein Granit) kann jedoch zur Bildung von sekundärem Kassiterite (SnO2) führen, womit der Skarn plötzlich wirtschaftlich hoch interessant sein kann. KW - Hämmerlein KW - skarn KW - tin KW - ore deposit KW - geochronology KW - lithium KW - boron KW - Hämmerlein KW - Skarn KW - Zinn KW - Lagerstätte KW - Geochronologie KW - Lithium KW - Bor Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427178 ER - TY - THES A1 - Goktas, Melis T1 - Coiled coils as molecular force sensors for the extracellular matrix T1 - Coiled coils als molekulare Kraftsensoren für die extrazelluläre Matrix N2 - Kraft spielt eine fundamentale Rolle bei der Regulation von biologischen Prozessen. Zellen messen mechanische Eigenschaften der extrazellulären Matrix und benutzen diese Information zur Regulierung ihrer Funktion. Dazu werden im Zytoskelett Kräfte generiert und auf extrazelluläre Rezeptor-Ligand Wechselwirkungen übertragen. Obwohl der grundlegende Einfluss von mechanischen Signalen für das Zellschicksal eindeutig belegt ist, sind die auf molekularer Ebene wirkenden Kräfte kaum bekannt. Zur Messung dieser Kräfte wurden verschiedene molekulare Kraftsensoren entwickelt, die ein mechanisches Inputsignal aufnehmen und in einen optischen Output (Fluoreszenz) umwandeln. Diese Arbeit etabliert einen neuen Kraftsensor-Baustein, der die mechanischen Eigenschaften der extrazellulären Matrix nachbildet. Dieser Baustein basiert auf natürlichen Matrixproteinen, sogenannten coiled coils (CCs), die α-helikale Strukturen im Zytoskelett und der Matrix formen. Eine Serie an CC-Heterodimeren wurde konzipiert und mittels Einzelmolekül-Kraftspektroskopie und Molekulardynamik-Simulationen charakterisiert. Es wurde gezeigt, dass eine anliegende Scherkraft die Entfaltung der helikalen Struktur induziert. Die mechanische Stabilität (Separation der CC Helices) wird von der CC Länge und der Zuggeschwindigkeit bestimmt. Im Folgenden wurden 2 CCs unterschiedlicher Länge als Kraftsensoren verwendet, um die Adhäsionskräfte von Fibroblasten und Endothelzellen zu untersuchen. Diese Kraftsensoren deuten an, dass diese Zelltypen unterschiedlich starke Kräften generieren und mittels Integrin-Rezeptoren auf einen extrazellulären Liganden (RGD-Peptid) übertragen. Dieses neue CC-basierte Sensordesign ist ein leistungsstarkes Werkzeug zur Betrachtung zellulärer Kraftwahrnehmungsprozesse auf molekularer Ebene, das neue Erkenntnisse über die involvierten Mechanismen und Kräfte an der Zell-Matrix-Schnittstelle ermöglicht. Darüber hinaus wird dieses Sensordesign auch Anwendung bei der Entwicklung mechanisch kontrollierter Biomaterialien finden. Dazu können mechanisch charakterisierte, und mit einem Fluoreszenzreporter versehene, CCs in Hydrogele eingefügt werden. Dies erlaubt die Untersuchung der Zusammenhänge zwischen molekularer und makroskopischer Mechanik und eröffnet neue Möglichkeiten zur Diskriminierung von lokalen und globalen Faktoren, die die zelluläre Antwort auf mechanische Signale bestimmen. N2 - Force plays a fundamental role in the regulation of biological processes. Cells can sense the mechanical properties of the extracellular matrix (ECM) by applying forces and transmitting mechanical signals. They further use mechanical information for regulating a wide range of cellular functions, including adhesion, migration, proliferation, as well as differentiation and apoptosis. Even though it is well understood that mechanical signals play a crucial role in directing cell fate, surprisingly little is known about the range of forces that define cell-ECM interactions at the molecular level. Recently, synthetic molecular force sensor (MFS) designs have been established for measuring the molecular forces acting at the cell-ECM interface. MFSs detect the traction forces generated by cells and convert this mechanical input into an optical readout. They are composed of calibrated mechanoresponsive building blocks and are usually equipped with a fluorescence reporter system. Up to date, many different MFS designs have been introduced and successfully used for measuring forces involved in the adhesion of mammalian cells. These MFSs utilize different molecular building blocks, such as double-stranded deoxyribonucleic acid (dsDNA) molecules, DNA hairpins and synthetic polymers like polyethylene glycol (PEG). These currently available MFS designs lack ECM mimicking properties. In this work, I introduce a new MFS building block for cell biology applications, derived from the natural ECM. It combines mechanical tunability with the ability to mimic the native cellular microenvironment. Inspired by structural ECM proteins with load bearing function, this new MFS design utilizes coiled coil (CC)-forming peptides. CCs are involved in structural and mechanical tasks in the cellular microenvironment and many of the key protein components of the cytoskeleton and the ECM contain CC structures. The well-known folding motif of CC structures, an easy synthesis via solid phase methods and the many roles CCs play in biological processes have inspired studies to use CCs as tunable model systems for protein design and assembly. All these properties make CCs ideal candidates as building blocks for MFSs. In this work, a series of heterodimeric CCs were designed, characterized and further used as molecular building blocks for establishing a novel, next-generation MFS prototype. A mechanistic molecular understanding of their structural response to mechanical load is essential for revealing the sequence-structure-mechanics relationships of CCs. Here, synthetic heterodimeric CCs of different length were loaded in shear geometry and their mechanical response was investigated using a combination of atomic force microscope (AFM)-based single-molecule force spectroscopy (SMFS) and steered molecular dynamics (SMD) simulations. SMFS showed that the rupture forces of short heterodimeric CCs (3-5 heptads) lie in the range of 20-50 pN, depending on CC length, pulling geometry and the applied loading rate (dF/dt). Upon shearing, an initial rise in the force, followed by a force plateau and ultimately strand separation was observed in SMD simulations. A detailed structural analysis revealed that CC response to shear load depends on the loading rate and involves helix uncoiling, uncoiling-assisted sliding in the direction of the applied force and uncoiling-assisted dissociation perpendicular to the force axis. The application potential of these mechanically characterized CCs as building blocks for MFSs has been tested in 2D cell culture applications with the goal of determining the threshold force for cell adhesion. Fully calibrated, 4- to 5-heptad long, CC motifs (CC-A4B4 and CC-A5B5) were used for functionalizing glass surfaces with MFSs. 3T3 fibroblasts and endothelial cells carrying mutations in a signaling pathway linked to cell adhesion and mechanotransduction processes were used as model systems for time-dependent adhesion experiments. A5B5-MFS efficiently supported cell attachment to the functionalized surfaces for both cell types, while A4B4-MFS failed to maintain attachment of 3T3 fibroblasts after the first 2 hours of initial cell adhesion. This difference in cell adhesion behavior demonstrates that the magnitude of cell-ECM forces varies depending on the cell type and further supports the application potential of CCs as mechanoresponsive and tunable molecular building blocks for the development of next-generation protein-based MFSs.This novel CC-based MFS design is expected to provide a powerful new tool for observing cellular mechanosensing processes at the molecular level and to deliver new insights into the mechanisms and forces involved. This MFS design, utilizing mechanically tunable CC building blocks, will not only allow for measuring the molecular forces acting at the cell-ECM interface, but also yield a new platform for the development of mechanically controlled materials for a large number of biological and medical applications. KW - molecular force sensors KW - cell-ECM interactions KW - extracellular matrix (ECM) KW - cellular forces KW - coiled coil KW - single molecule force spectroscopy KW - molekulare Kraftsensoren KW - Zell-Matrix-Wechselwirkung KW - extrazelluläre Matrix KW - zelluläre Kräfte KW - coiled coil KW - Einzelmolekül-Kraftspektroskopie Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427493 ER - TY - RPRT A1 - Caliendo, Marco A1 - Schröder, Carsten A1 - Wittbrodt, Linda T1 - The Causal Effects of the Minimum Wage Introduction in Germany BT - An Overview T2 - CEPA Discussion Papers N2 - In 2015, Germany introduced a statutory hourly minimum wage that was not only universally binding but also set at a relatively high level. We discuss the short-run effects of this new minimum wage on a wide set of socio-economic outcomes, such as employment and working hours, earnings and wage inequality, dependent and self-employment, as well as reservation wages and satisfaction. We also discuss difficulties in the implementation of the minimum wage and the measurement of its effects related to non-compliance and suitability of data sources. Two years after the minimum wage introduction, the following conclusions can be drawn: while hourly wages increased for low-wage earners, some small negative employment effects are also identifiable. The effects on aspired goals, such as poverty and inequality reduction, have not materialized in the short run. Instead, a tendency to reduce working hours is found, which alleviates the desired positive impact on monthly income. Additionally, the level of non-compliance was substantial in the short run, thus drawing attention to problems when implementing such a wide-reaching policy. T3 - CEPA Discussion Papers - 1 KW - Minimum Wage KW - Evaluation KW - Earnings KW - Working Hours KW - Employment Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426929 SN - 2628-653X IS - 1 ER - TY - JOUR A1 - Lonnemann, Jan A1 - Li, Su A1 - Zhao, Pei A1 - Linkersdörfer, Janosch A1 - Lindberg, Sven A1 - Hasselhorn, Marcus T1 - Differences in Counting Skills Between Chinese and German Children Are Accompanied by Differences in Processing of Approximate Numerical Magnitude Information JF - Frontiers in Psychology N2 - Human beings are supposed to possess an approximate number system (ANS) dedicated to extracting and representing approximate numerical magnitude information as well as an object tracking system (OTS) for the rapid and accurate enumeration of small sets. It is assumed that the OTS and the ANS independently contribute to the acquisition of more elaborate numerical concepts. Chinese children have been shown to exhibit more elaborate numerical concepts than their non-Chinese peers, but it is still an open question whether similar cross-national differences exist with regard to the underlying systems, namely the ANS and the OTS. In the present study, we investigated this question by comparing Chinese and German preschool children with regard to their performance in a non-symbolic numerical magnitude comparison task (assessing the ANS) and in an enumeration task (assessing the OTS). In addition, we compared children’s counting skills. To ensure that possible between-group differences could not be explained by differences in more general performance factors, we also assessed children’s reasoning ability and processing speed. Chinese children showed a better counting performance and a more accurate performance in the non-symbolic numerical magnitude comparison task. These differences in performance could not be ascribed to differences in reasoning abilities and processing speed. In contrast, Chinese and German children did not differ significantly in the enumeration of small sets. The superior counting performance of Chinese children was thus found to be reflected in the ANS but not in the OTS. KW - approximate number system KW - subitizing KW - counting KW - cross-national comparison KW - preschool Y1 - 2019 U6 - https://doi.org/10.3389/fpsyg.2018.02656 SN - 1664-1078 VL - 9 PB - Frontiers Research Foundation CY - Lausanne ER - TY - GEN A1 - Fay, Doris A1 - Urbach, Tina A1 - Scheithauer, Linda T1 - What motivates you right now? BT - Development of a measure of momentary-chronic regulatory focus T2 - Postprints der Universität Potsdam Humanwissenschaftliche Reihe N2 - Regulatory focus is a motivational construct that describes humans’ motivational orientation during goal pursuit. It is conceptualized as a chronic, trait-like, as well as a momentary, state-like orientation. Whereas there is a large number of measures to capture chronic regulatory focus, measures for its momentary assessment are only just emerging. This paper presents the development and validation of a measure of Momentary–Chronic Regulatory Focus. Our development incorporates the distinction between self-guide and reference-point definitions of regulatory focus. Ideals and ought striving are the promotion and prevention dimension in the self-guide system; gain and non-loss regulatory focus are the respective dimensions within the reference-point system. Three-survey-based studies test the structure, psychometric properties, and validity of the measure in its version to assess chronic regulatory focus (two samples of working participants, N = 389, N = 672; one student sample [time 1, N = 105; time 2, n = 91]). In two further studies, an experience sampling study with students (N = 84, k = 1649) and a daily-diary study with working individuals (N = 129, k = 1766), the measure was applied to assess momentary regulatory focus. Multilevel analyses test the momentary measure’s factorial structure, provide support for its sensitivity to capture within-person fluctuations, and provide evidence for concurrent construct validity. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 545 KW - Regulatory focus KW - State and trait measurement KW - Scale development KW - Diary study KW - Experience sampling method Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427350 SN - 1866-8364 IS - 545 ER - TY - JOUR A1 - Fay, Doris A1 - Urbach, Tina A1 - Scheithauer, Linda T1 - What motivates you right now? BT - Development of a measure of momentary-chronic regulatory focus JF - Measurement Instruments for the Social Sciences N2 - Regulatory focus is a motivational construct that describes humans’ motivational orientation during goal pursuit. It is conceptualized as a chronic, trait-like, as well as a momentary, state-like orientation. Whereas there is a large number of measures to capture chronic regulatory focus, measures for its momentary assessment are only just emerging. This paper presents the development and validation of a measure of Momentary–Chronic Regulatory Focus. Our development incorporates the distinction between self-guide and reference-point definitions of regulatory focus. Ideals and ought striving are the promotion and prevention dimension in the self-guide system; gain and non-loss regulatory focus are the respective dimensions within the reference-point system. Three-survey-based studies test the structure, psychometric properties, and validity of the measure in its version to assess chronic regulatory focus (two samples of working participants, N = 389, N = 672; one student sample [time 1, N = 105; time 2, n = 91]). In two further studies, an experience sampling study with students (N = 84, k = 1649) and a daily-diary study with working individuals (N = 129, k = 1766), the measure was applied to assess momentary regulatory focus. Multilevel analyses test the momentary measure’s factorial structure, provide support for its sensitivity to capture within-person fluctuations, and provide evidence for concurrent construct validity. KW - Regulatory focus KW - State and trait measurement KW - Scale development KW - Diary study KW - Experience sampling method Y1 - 2019 U6 - https://doi.org/10.1186/s42409-019-0007-7 SN - 2523-8930 VL - 2 IS - 5 PB - BioMed Central CY - London ER - TY - GEN A1 - Wright, Michelle F. A1 - Wachs, Sebastian T1 - Does Peer Rejection Moderate the Associations among Cyberbullying Victimization, Depression, and Anxiety among Adolescents with Autism Spectrum Disorder? T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe N2 - While the consequences of cyberbullying victimization have received some attention in the literature, to date, little is known about the multiple types of strains in adolescents’ lives, such as whether cyberbullying victimization and peer rejection increase their vulnerability to depression and anxiety. Even though some research found that adolescents with disabilities show higher risk for cyberbullying victimization, most research has focused on typically developing adolescents. Thus, the present study focused on examining the moderating effect of peer rejection in the relationships between cyberbullying victimization, depression, and anxiety among adolescents with autism spectrum disorder. There were 128 participants (89% male; ages ranging from 11–16 years old) with autism spectrum disorder in the sixth, seventh, or eighth grade at 16 middle schools in the United States. Participants completed questionnaires on cyberbullying victimization, peer rejection, depression, and anxiety. Results revealed that cyberbullying victimization was associated positively with peer rejection, anxiety, and depression among adolescents with autism spectrum disorder. Further, peer rejection was linked positively with depression and anxiety. Peer rejection moderated the positive relationship between cyberbullying victimization and depression, but not anxiety. Implications for prevention programs and future research are discussed. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 544 KW - anxiety KW - depression KW - cyberbullying victimization KW - autism spectrum disorder KW - peer rejection Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427266 EP - 544 ER - TY - JOUR A1 - Wright, Michelle F. A1 - Wachs, Sebastian T1 - Does Peer Rejection Moderate the Associations among Cyberbullying Victimization, Depression, and Anxiety among Adolescents with Autism Spectrum Disorder? JF - Children N2 - While the consequences of cyberbullying victimization have received some attention in the literature, to date, little is known about the multiple types of strains in adolescents’ lives, such as whether cyberbullying victimization and peer rejection increase their vulnerability to depression and anxiety. Even though some research found that adolescents with disabilities show higher risk for cyberbullying victimization, most research has focused on typically developing adolescents. Thus, the present study focused on examining the moderating effect of peer rejection in the relationships between cyberbullying victimization, depression, and anxiety among adolescents with autism spectrum disorder. There were 128 participants (89% male; ages ranging from 11–16 years old) with autism spectrum disorder in the sixth, seventh, or eighth grade at 16 middle schools in the United States. Participants completed questionnaires on cyberbullying victimization, peer rejection, depression, and anxiety. Results revealed that cyberbullying victimization was associated positively with peer rejection, anxiety, and depression among adolescents with autism spectrum disorder. Further, peer rejection was linked positively with depression and anxiety. Peer rejection moderated the positive relationship between cyberbullying victimization and depression, but not anxiety. Implications for prevention programs and future research are discussed. KW - anxiety KW - depression KW - cyberbullying victimization KW - autism spectrum disorder KW - peer rejection Y1 - 2019 U6 - https://doi.org/10.3390/children6030041 SN - 2227-9067 VL - 6 EP - 3 PB - MDPI CY - Basel ER - TY - GEN A1 - Kalinowski, Eva A1 - Gronostaj, Anna A1 - Vock, Miriam T1 - Effective Professional Development for Teachers to Foster Students’ Academic Language Proficiency Across the Curriculum BT - A Systematic Review T2 - Postprints der Universität Potsdam Humanwissenschaftliche Reihe N2 - This review summarizes features of professional development programs that aim to prepare in-service teachers to improve students’ academic language proficiency when teaching subject areas. The 38 studies reviewed suggest that all of the profiled interventions were effective to some extent. The programs share many characteristics considered important in successful teacher professional development across different subject areas. They also include some features that appear to be specific to teacher training in this particular domain. This review supports the idea that professional development helps change teachers’ thinking and practice and benefits students, if certain features are taken into consideration in its design and implementation. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 543 KW - professional development KW - language KW - cross-curriculum KW - content areas KW - in-service teacher training Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427219 SN - 1866-8364 IS - 543 ER - TY - JOUR A1 - Kalinowski, Eva A1 - Gronostaj, Anna A1 - Vock, Miriam T1 - Effective Professional Development for Teachers to Foster Students’ Academic Language Proficiency Across the Curriculum BT - A Systematic Review JF - AERA Open N2 - This review summarizes features of professional development programs that aim to prepare in-service teachers to improve students’ academic language proficiency when teaching subject areas. The 38 studies reviewed suggest that all of the profiled interventions were effective to some extent. The programs share many characteristics considered important in successful teacher professional development across different subject areas. They also include some features that appear to be specific to teacher training in this particular domain. This review supports the idea that professional development helps change teachers’ thinking and practice and benefits students, if certain features are taken into consideration in its design and implementation. KW - professional development KW - language KW - cross-curriculum KW - content areas KW - in-service teacher training Y1 - 2019 U6 - https://doi.org/10.1177/2332858419828691 SN - 2332-8584 VL - 5 IS - 1 SP - 1 EP - 23 PB - Sage CY - Thousand Oaks ER - TY - JOUR A1 - Sarhan, Radwan Mohamed A1 - Koopman, Wouter-Willem Adriaan A1 - Schuetz, Roman A1 - Schmid, Thomas A1 - Liebig, Ferenc A1 - Koetz, Joachim A1 - Bargheer, Matias T1 - The importance of plasmonic heating for the plasmondriven photodimerization of 4-nitrothiophenol JF - Scientific Reports N2 - Metal nanoparticles form potent nanoreactors, driven by the optical generation of energetic electrons and nanoscale heat. The relative influence of these two factors on nanoscale chemistry is strongly debated. This article discusses the temperature dependence of the dimerization of 4-nitrothiophenol (4-NTP) into 4,4′-dimercaptoazobenzene (DMAB) adsorbed on gold nanoflowers by Surface-Enhanced Raman Scattering (SERS). Raman thermometry shows a significant optical heating of the particles. The ratio of the Stokes and the anti-Stokes Raman signal moreover demonstrates that the molecular temperature during the reaction rises beyond the average crystal lattice temperature of the plasmonic particles. The product bands have an even higher temperature than reactant bands, which suggests that the reaction proceeds preferentially at thermal hot spots. In addition, kinetic measurements of the reaction during external heating of the reaction environment yield a considerable rise of the reaction rate with temperature. Despite this significant heating effects, a comparison of SERS spectra recorded after heating the sample by an external heater to spectra recorded after prolonged illumination shows that the reaction is strictly photo-driven. While in both cases the temperature increase is comparable, the dimerization occurs only in the presence of light. Intensity dependent measurements at fixed temperatures confirm this finding. KW - enhanced raman-scattering KW - charge-transfer KW - metal KW - nanoparticles KW - catalysis KW - AU KW - 4-nitrobenzenethiol KW - aminothiophenol KW - photocatalysis KW - wavelength Y1 - 2019 U6 - https://doi.org/10.1038/s41598-019-38627-2 SN - 2045-2322 VL - 9 PB - Macmillan Publishers Limited CY - London ER - TY - THES A1 - Raatz, Michael T1 - Strategies within predator-prey interactions – from individuals to ecosystems T1 - Strategien in Räuber-Beute Interaktionen – vom Individuum bis zum Ökosystem N2 - Predator-prey interactions provide central links in food webs. These interaction are directly or indirectly impacted by a number of factors. These factors range from physiological characteristics of individual organisms, over specifics of their interaction to impacts of the environment. They may generate the potential for the application of different strategies by predators and prey. Within this thesis, I modelled predator-prey interactions and investigated a broad range of different factors driving the application of certain strategies, that affect the individuals or their populations. In doing so, I focused on phytoplankton-zooplankton systems as established model systems of predator-prey interactions. At the level of predator physiology I proposed, and partly confirmed, adaptations to fluctuating availability of co-limiting nutrients as beneficial strategies. These may allow to store ingested nutrients or to regulate the effort put into nutrient assimilation. We found that these two strategies are beneficial at different fluctuation frequencies of the nutrients, but may positively interact at intermediate frequencies. The corresponding experiments supported our model results. We found that the temporal structure of nutrient fluctuations indeed has strong effects on the juvenile somatic growth rate of {\itshape Daphnia}. Predator colimitation by energy and essential biochemical nutrients gave rise to another physiological strategy. High-quality prey species may render themselves indispensable in a scenario of predator-mediated coexistence by being the only source of essential biochemical nutrients, such as cholesterol. Thereby, the high-quality prey may even compensate for a lacking defense and ensure its persistence in competition with other more defended prey species. We found a similar effect in a model where algae and bacteria compete for nutrients. Now, being the only source of a compound that is required by the competitor (bacteria) prevented the competitive exclusion of the algae. In this case, the essential compounds were the organic carbon provided by the algae. Here again, being indispensable served as a prey strategy that ensured its coexistence. The latter scenario also gave rise to the application of the two metabolic strategies of autotrophy and heterotrophy by algae and bacteria, respectively. We found that their coexistence allowed the recycling of resources in a microbial loop that would otherwise be lost. Instead, these resources were made available to higher trophic levels, increasing the trophic transfer efficiency in food webs. The predation process comprises the next higher level of factors shaping the predator-prey interaction, besides these factors that originated from the functioning or composition of individuals. Here, I focused on defensive mechanisms and investigated multiple scenarios of static or adaptive combinations of prey defense and predator offense. I confirmed and extended earlier reports on the coexistence-promoting effects of partially lower palatability of the prey community. When bacteria and algae are coexisting, a higher palatability of bacteria may increase the average predator biomass, with the side effect of making the population dynamics more regular. This may facilitate experimental investigations and interpretations. If defense and offense are adaptive, this allows organisms to maximize their growth rate. Besides this fitness-enhancing effect, I found that co-adaptation may provide the predator-prey system with the flexibility to buffer external perturbations. On top of these rather internal factors, environmental drivers also affect predator-prey interactions. I showed that environmental nutrient fluctuations may create a spatio-temporal resource heterogeneity that selects for different predator strategies. I hypothesized that this might favour either storage or acclimation specialists, depending on the frequency of the environmental fluctuations. We found that many of these factors promote the coexistence of different strategies and may therefore support and sustain biodiversity. Thus, they might be relevant for the maintenance of crucial ecosystem functions that also affect us humans. Besides this, the richness of factors that impact predator-prey interactions might explain why so many species, especially in the planktonic regime, are able to coexist. N2 - Organismen interagieren miteinander und mit ihrer Umwelt. Innerhalb dieses Netzwerks von Interaktionen sind Fraßbeziehungen zwischen Räubern und ihrer Beute von zentraler Bedeutung. Sie werden auf verschiedenen Ebenen von unterschiedlichen Faktoren beeinflusst, was zur Ausprägung von diversen Strategien von Räuber oder Beute führen kann. Diese Faktoren und die Strategien die sie hervor bringen sind Gegenstand dieser Doktorarbeit. In mehreren Modellierungsstudien habe ich vielseitige Faktoren untersucht, die sich dem Aufbau einzelner Organismen, Verteidigungs- und Angriffsmechanismen sowie Umwelteinflüssen zuordnen lassen. Dabei konzentrierte ich mich auf ein etabliertes Modellsystem zur Erforschung von Räuber-Beute-Dynamiken und untersuchte die Fraßbeziehung zwischen Phytoplankton als Beute und Zooplankton als Räuber. Ich fand heraus, dass die Bereitstellung von essentiellen Ressourcen für Konkurrenten oder Räuber eine Strategie sein kann, mit der Beutearten sich vor dem Aussterben schützen können. Auch die direkte Verteidigung gegen den Räuber ist eine häufige Strategie zur Verringerung des Fraßdrucks und kann ebenfalls Koexistenz fördern. Für anpassungsfähige Verteidigung der Beute und Angriffsstärke des Räubers konnte ich zeigen, dass dies sowohl die Fitness erhöhen, als auch die Robustheit der Räuber-Beute-Dynamiken gegen äußere Störungen erhöhen kann. Weiterhin fand ich heraus, dass physiologische Anpassungsmechanismen wie Speicherung oder anpassungsfähige Aufnahme von Nährstoffen die Wachstumsrate des Räubers verbessern können, wenn die Qualität der verfügbaren Beute in der Umwelt des Räubers fluktuiert. Viele der Strategien, die ich in dieser Arbeit herausgestellt habe, können die Koexistenz von verschiedenen Arten fördern und damit zu erhöhter Biodiversität beitragen, welche wiederum entscheidend ist für die Stabilität von Ökosystemen und deren Nutzbarkeit. KW - predator-prey KW - biodiversity KW - modelling KW - Räuber-Beute KW - Biodiversität KW - Modellierung Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426587 ER - TY - THES A1 - Perlaza-Jimenez, Laura T1 - Discerning functional associations and relationships between molecules in Arabidopsis thaliana using genome-wide correlated mutations Y1 - 2019 ER - TY - THES A1 - Cecchini, Gloria T1 - Improving network inference by overcoming statistical limitations T1 - Verbesserung der Netzwerkrekonstruktion durch überwinden statistischer Limits N2 - A reliable inference of networks from data is of key interest in many scientific fields. Several methods have been suggested in the literature to reliably determine links in a network. These techniques rely on statistical methods, typically controlling the number of false positive links, but not considering false negative links. In this thesis new methodologies to improve network inference are suggested. Initial analyses demonstrate the impact of falsepositive and false negative conclusions about the presence or absence of links on the resulting inferred network. Consequently, revealing the importance of making well-considered choices leads to suggest new approaches to enhance existing network reconstruction methods. A simulation study, presented in Chapter 3, shows that different values to balance false positive and false negative conclusions about links should be used in order to reliably estimate network characteristics. The existence of type I and type II errors in the reconstructed network, also called biased network, is accepted. Consequently, an analytic method that describes the influence of these two errors on the network structure is explored. As a result of this analysis, an analytic formula of the density of the biased vertex degree distribution is found (Chapter 4). In the inverse problem, the vertex degree distribution of the true underlying network is analytically reconstructed, assuming the probabilities of type I and type II errors. Chapters 4-5 show that the method is robust to incorrect estimates of α and β within reasonable limits. In Chapter 6, an iterative procedure to enhance this method is presented in the case of large errors on the estimates of α and β. The investigations presented so far focus on the influence of false positive and false negative links on the network characteristics. In Chapter 7, the analysis is reversed - the study focuses on the influence of network characteristics on the probability of type I and type II errors, in the case of networks of coupled oscillators. The probabilities of α and β are influenced by the shortest path length and the detour degree, respectively. These results have been used to improve the network reconstruction, when the true underlying network is not known a priori, introducing a novel and advanced concept of threshold. N2 - Eine zuverlässige Rekonstruktion eines Netzwerks aus Daten ist von entscheidender Bedeutung in der Wissenschaft. Einige Methoden werden in der Literatur vorgeschlagen um Verbindungen in einem Netzwerk akkurat zu bestimmen. Diese Methoden vertrauen auf die Anwendung der Statistik, indem sie falsch positive Verbindungen berücksichtigen, allerdings positiv falsche Verbindungen ignoriert. In dieser Arbeit werden neue Methoden vorgeschlagen, um die Rekonstruktion zu verbessern. Erste Analysen veranschaulichen den Einfluss falsch positiver und positiv falscher Verbindungen auf das resultierende Netzwerk. Daraus wird die Bedeutsamkeit ersichtlich, die eine gut gewählte Entscheidung hinsichtlich der Faktoren auf die Qualität der Rekonstruktion hat, wodurch sich neu Methoden ableiten lassen. Eine Simulation, welche in Kapitel 3 zu finden ist, veranschaulicht, dass verschiedene Werte für falsch postive und positiv falsche Verbindungen zu verwenden sind, um genaue Vorhersagen bezüglich des Netzwerkverhaltens zu treffen. Die Existenz Fehler erster und zweiter Art in der Rekonstruktion sind unvermeidbar und werden akzeptiert. Ein analytischer Ansatz, der den Einfluss dieser beiden Fehler beschreibt wird gesucht. Aus dieser Analyse in Kapitel 4 folgt eine Formel welche die Verteilung der Quantität der Knotenverbindungen beschreibt. Bei dem inversen Problem wird die Knotengrad-Verteilung des originalen Netzwerkes, mit Berücksichtigung der Wahrscheinlichkeit von Fehlern erster und zweiter Art, analytisch berechnet. Kapitel 4-5 zeigen, dass die Methode auch bei einigermaßen falschen Schätzungen von α und β Resultate innerhalb vertretbarer Grenzen liefert. In Kapitel 6 wird ein iteratives Verfahren vorgestellt, welches diese Methode bei außerordentlich falschen Schätzungen von α und β verbessert. Die bis jetzt vorgestellte Recherche fokussiert sich auf den Einfluss falsch positiver und positiv falscher Verbindungen auf die Netzwerkscharakteristik. Im Kapitel 7 wird der Prozess umgedreht. Die Arbeit fokussiert sich auf den Einfluss auf die Netzwerkkarakteristik durch die Fehler erster und zweiter Art im Falle eines Netzwerkes mit gekoppelten Oszillatoren. Die Wahrscheinlichkeit von α und β wird beeinflusst durch den kürzesten Verbindungsweg und dem Detour Grad. Diese Ergebnisse wurden genutzt um die Netzwerk Rekonstruktion zu verbessern, wenn das originale Netzwerk nicht zuvor bekannt war. Dies beschreibt einen neuen fortgeschritten Weg der Grenzwertbestimmung. KW - network inference KW - network reconstruction KW - statistical methods KW - Netzwerk Inferenz KW - Netzwerk Rekonstruktion KW - statistische Methoden Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426705 ER - TY - RPRT A1 - Krieger, Heike T1 - Populist governments and international law T2 - KFG Working Paper Series N2 - The worldwide populist wave has contributed to a perception that international law is currently in a state of crisis. This article examines in how far populist governments have challenged prevailing interpretations of international law. The article links structural features of populism with an analysis of populist governmental strategies and argumentative practices. It demonstrates that, in their rhetoric, populist governments promote an understanding of international law as a mere law of coordination. This is, however, not entirely reflected in their legal practices where an instrumental, cherry-picking approach prevails. The article concludes that policies of populist governments affect the current state of international law on two different levels: In the political sphere their practices alter the general environment in which legal rules are interpreted. In the legal sphere populist governments push for changes in the interpretation of established international legal rules. The article substantiates these propositions by focusing on the principle of nonintervention and foreign funding for NGOs. T3 - KFG Working Paper Series - 29 Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426863 IS - 29 ER - TY - RPRT A1 - McLachlan, Campbell T1 - The assault on international adjudication and the limits of withdrawal T2 - KFG Working Paper Series N2 - International adjudication is currently under assault, encouraging a number of States to withdraw, or to consider withdrawing, from treaties providing for international dispute settlement. This Working Paper argues that the act of treaty withdrawal is not merely as the unilateral executive exercise of the individual sovereign prerogative of a State. International law places checks upon the exercise of withdrawal, recognising that it is an act that of its nature affects the interests of other States parties, which have a collective interest in constraining withdrawal. National courts have a complementary function in restraining unilateral withdrawal in order to support the domestic constitution. The arguments advanced against international adjudication in the name of popular democracy at the national level can serve as a cloak for the exercise of executive power unrestrained by law. The submission by States of their disputes to peaceful settlement through international adjudication is central, not incidental, to the successful operation of the international legal system. T3 - KFG Working Paper Series - 28 Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426855 IS - 28 ER - TY - THES A1 - Gawron, Marian T1 - Towards automated advanced vulnerability analysis N2 - The identification of vulnerabilities in IT infrastructures is a crucial problem in enhancing the security, because many incidents resulted from already known vulnerabilities, which could have been resolved. Thus, the initial identification of vulnerabilities has to be used to directly resolve the related weaknesses and mitigate attack possibilities. The nature of vulnerability information requires a collection and normalization of the information prior to any utilization, because the information is widely distributed in different sources with their unique formats. Therefore, the comprehensive vulnerability model was defined and different sources have been integrated into one database. Furthermore, different analytic approaches have been designed and implemented into the HPI-VDB, which directly benefit from the comprehensive vulnerability model and especially from the logical preconditions and postconditions. Firstly, different approaches to detect vulnerabilities in both IT systems of average users and corporate networks of large companies are presented. Therefore, the approaches mainly focus on the identification of all installed applications, since it is a fundamental step in the detection. This detection is realized differently depending on the target use-case. Thus, the experience of the user, as well as the layout and possibilities of the target infrastructure are considered. Furthermore, a passive lightweight detection approach was invented that utilizes existing information on corporate networks to identify applications. In addition, two different approaches to represent the results using attack graphs are illustrated in the comparison between traditional attack graphs and a simplistic graph version, which was integrated into the database as well. The implementation of those use-cases for vulnerability information especially considers the usability. Beside the analytic approaches, the high data quality of the vulnerability information had to be achieved and guaranteed. The different problems of receiving incomplete or unreliable information for the vulnerabilities are addressed with different correction mechanisms. The corrections can be carried out with correlation or lookup mechanisms in reliable sources or identifier dictionaries. Furthermore, a machine learning based verification procedure was presented that allows an automatic derivation of important characteristics from the textual description of the vulnerabilities. N2 - Die Erkennung von Schwachstellen ist ein schwerwiegendes Problem bei der Absicherung von modernen IT-Systemen. Mehrere Sicherheitsvorfälle hätten durch die vorherige Erkennung von Schwachstellen verhindert werden können, da in diesen Vorfällen bereits bekannte Schwachstellen ausgenutzt wurden. Der Stellenwert der Sicherheit von IT Systemen nimmt immer weiter zu, was auch mit der Aufmerksamkeit, die seit kurzem auf die Sicherheit gelegt wird, zu begründen ist. Somit nimmt auch der Stellenwert einer Schwachstellenanalyse der IT Systeme immer mehr zu, da hierdurch potenzielle Angriffe verhindert und Sicherheitslücken geschlossen werden können. Die Informationen über Sicherheitslücken liegen in verschiedenen Quellen in unterschiedlichen Formaten vor. Aus diesem Grund wird eine Normalisierungsmethode benötigt, um die verschiedenen Informationen in ein einheitliches Format zu bringen. Das damit erzeugte Datenmodell wird in der HPI-VDB gespeichert, in die auch darauf aufbauende Analyseansätze integriert wurden. Diese Analysemethoden profitieren direkt von den Eigenschaften des Datenmodells, das maschinenlesbare Vor- und Nachbedingungen enthält. Zunächst wurden verschiedene Methoden zur Erkennung von Schwachstellen in IT Systemen von durchschnittlichen Nutzern und auch in Systemen von großen Firmen entwickelt. Hierbei wird der Identifikation der installierten Programme die größte Aufmerksamkeit beigemessen, da es der grundlegende Bestandteil der Erkennung von Schwachstellen ist. Für die Ansätze wird weiterhin die Erfahrung des Nutzers und die Eigenschaften der Zielumgebung berücksichtigt. Zusätzlich wurden zwei weitere Ansätze zur Repräsentation der Ergebnisse integriert. Hierfür wurden traditionelle Angriffsgraphen mit einer vereinfachten Variante verglichen, die auch in die Datenbank integriert wurde. Des Weiteren spielt die Datenqualität eine wichtige Rolle, da die Effizienz der Analysemethoden von der Qualität der Informationen abhängt. Deshalb wurden Probleme wie Unvollständigkeit und Unzuverlässigkeit der Informationen mit verschiedenen Korrekturansätzen bewältigt. Diese Korrekturen werden mithilfe von Korrelationen und Maschinellem Lernen bewerkstelligt, wobei die automatische Ausführbarkeit eine grundlegende Anforderung darstellt. KW - IT-security KW - vulnerability KW - analysis KW - IT-Sicherheit KW - Schwachstelle KW - Analyse Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426352 ER - TY - THES A1 - Kegelmann, Lukas T1 - Advancing charge selective contacts for efficient monolithic perovskite-silicon tandem solar cells T1 - Entwicklung Ladungsselektiver Kontakte für Effiziente Monolithische Perowskit-Silizium Tandem-Solarzellen N2 - Hybrid organic-inorganic perovskites are one of the most promising material classes for photovoltaic energy conversion. In solar cells, the perovskite absorber is sandwiched between n- and p-type contact layers which selectively transport electrons and holes to the cell’s cathode and anode, respectively. This thesis aims to advance contact layers in perovskite solar cells and unravel the impact of interface and contact properties on the device performance. Further, the contact materials are applied in monolithic perovskite-silicon heterojunction (SHJ) tandem solar cells, which can overcome the single junction efficiency limits and attract increasing attention. Therefore, all contact layers must be highly transparent to foster light harvesting in the tandem solar cell design. Besides, the SHJ device restricts processing temperatures for the selective contacts to below 200°C. A comparative study of various electron selective contact materials, all processed below 180°C, in n-i-p type perovskite solar cells highlights that selective contacts and their interfaces to the absorber govern the overall device performance. Combining fullerenes and metal-oxides in a TiO2/PC60BM (phenyl-C60-butyric acid methyl ester) double-layer contact allows to merge good charge extraction with minimized interface recombination. The layer sequence thereby achieved high stabilized solar cell performances up to 18.0% and negligible current-voltage hysteresis, an otherwise pronounced phenomenon in this device design. Double-layer structures are therefore emphasized as a general concept to establish efficient and highly selective contacts. Based on this success, the concept to combine desired properties of different materials is transferred to the p-type contact. Here, a mixture of the small molecule Spiro-OMeTAD [2,2’,7,7’-tetrakis(N,N-di-p-methoxyphenylamine)-9,9’-spirobifluoren] and the doped polymer PEDOT [poly(3,4-ethylenedioxythiophene)] is presented as a novel hole selective contact. PEDOT thereby remarkably suppresses charge recombination at the perovskite surface, allowing an increase of quasi-Fermi level splitting in the absorber. Further, the addition of Spiro-OMeTAD into the PEDOT layer is shown to enhance charge extraction at the interface and allow high efficiencies up to 16.8%. Finally, the knowledge on contact properties is applied to monolithic perovskite-SHJ tandem solar cells. The main goal is to optimize the top contact stack of doped Spiro-OMeTAD/molybdenum oxide(MoOx)/ITO towards higher transparency by two different routes. First, fine-tuning of the ITO deposition to mitigate chemical reduction of MoOx and increase the transmittance of MoOx/ITO stacks by 25%. Second, replacing Spiro-OMeTAD with the alternative hole transport materials PEDOT/Spiro-OMeTAD mixtures, CuSCN or PTAA [poly(triaryl amine)]. Experimental results determine layer thickness constrains and validate optical simulations, which subsequently allow to realistically estimate the respective tandem device performances. As a result, PTAA represents the most promising replacement for Spiro-OMeTAD, with a projected increase of the optimum tandem device efficiency for the herein used architecture by 2.9% relative to 26.5% absolute. The results also reveal general guidelines for further performance gains of the technology. N2 - Hybride, organisch-anorganische Perowskite gelten als eine der vielversprechendsten Materialklassen für die photovoltaische Energieumwandlung. Dazu werden Perowskit-Absorber in Solarzellen zwischen n- und p-Typ Kontaktschichten angeordnet, die Elektronen oder Löcher selektiv zur Kathode bzw. Anode der Zelle transportieren. Ziel dieser Arbeit ist es, die ladungsselektiven Transportschichten in Perowskit-Solarzellen zu verbessern und Einflüsse der Grenzflächen- und Kontakteigenschaften auf die Zelleffizienz herauszustellen. Darüber hinaus werden die selektiven Schichten in monolithischen Perowskit-Silizium-Heterokontakt (SHK) Tandem-Solarzellen eingesetzt. Diese können höhere Wirkungsgrade als Einfachsolarzellen erzielen und erfahren zunehmende Aufmerksamkeit aus der Forschung. Hierfür müssen alle Kontaktschichten hochtransparent sein, um eine möglichst effiziente Lichtausnutzung im Tandem-Solarzellen-Design zu erzielen. Des Weiteren limitiert die SHK-Solarzelle die höchst mögliche Temperatur zur Abscheidung der selektiven Kontakte auf 200°C. In einer Vergleichsstudie werden deshalb zunächst verschiedene elektronenselektive Kontaktmaterialien, die alle unter 180°C prozessiert werden, in n-i-p-Typ Perowskit-Solarzellen eingesetzt. Es zeigt sich hierbei, wie wesentlich die selektiven Kontakte und ihre Grenzflächen zum Absorber die Effizienz der Solarzellen bestimmen. Eine Kombination aus Fulleren und Metalloxid in einem TiO2/PC60BM (Phenyl-C60-Buttersäuremethylester) Doppelschichtkontakt ermöglicht dabei eine besonders gute Ladungsextraktion und stark reduzierte Grenzflächenrekombination. Die Materialzusammenstellung erreicht in der Studie hohe stabilisierte Solarzellenwirkungsgrade bis zu 18,0% und eine vernachlässigbare Strom-Spannungs-Hysterese, ein üblicherweise ausgeprägtes Phänomen in diesem Zellaufbau. Das Ergebnis stellt Doppelschicht-Strukturen als generelles Konzept zur Herstellung effizienter und hochselektiver Kontakte heraus. Basierend auf diesem Erfolg wird das Konzept, Eigenschaften verschiedener Materialien miteinander zu kombinieren, anschließend auf den p-Typ Kontakt übertragen. Dazu wird ein neuartiger lochselektiver Kontakt vorgestellt, bestehend aus einer Mischung des kleinen Moleküls Spiro-OMeTAD [2,2‘7,7‘-tetrakis(N,N-di-p-methoxyphenylamin)-9,9‘-spirobifluoren] und dem dotierten Polymer PEDOT [poly(3,4-ethylendioxythiophen)]. PEDOT unterdrückt dabei bemerkenswerter Weiße die Ladungsträgerrekombination an der Perowskit-Grenzfläche, wodurch eine Erhöhung der Quasi-Fermi-Niveau-Aufspaltung im Absorber erzielt wird. Weiterhin wird gezeigt, dass die Zugabe von Spiro-OMeTAD in die PEDOT-Schicht die Lochextraktion an der Grenzfläche verbessert und folglich hohe Solarzellenwirkungsgrade von bis zu 16,8% ermöglicht. Schließlich wird das gewonnene Wissen über die Bedeutung der Kontakt- und Grenzflächeneigenschaften auf monolithische Perowskit-SHK-Tandemsolarzellen angewandt. Das Hauptziel dabei ist die Optimierung des oberen Kontaktstapels, bestehend aus dotiertem Spiro-OMeTAD/Molybdän Oxid (MoOx)/ITO, hin zu verbesserter Transparenz. Zwei verschiedene Ansätze werden hierzu verfolgt. Erstens, durch Feinanpassung der ITO-Abscheidung kann eine chemische Reduktion von MoOx verringert und die Transmission von MoOx/ITO-Schichtstapeln um 25% erhöht werden. Zweitens: Durch Ersetzen des Spiro-OMeTAD mit alternativen, transparenteren Lochtransportmaterialien sollen parasitäre Absorptionsverluste vermieden werden. Als potentielle Lochkontakte werden dabei PEDOT/Spiro-OMeTAD-Mischungen, CuSCN und PTAA [Poly(triarylamin)] analysiert. Experimentelle Untersuchungen liefern optimierte Dicken der Lochkontakt und MoOx Schichten und dienen der Validierung optischer Simulationen der Schichtstapel. Dies erlaubt im Folgenden eine realistische Abschätzung der maximal erreichbaren Tandemsolarzelleneffizienzen. Dabei stellt PTAA den vielversprechendsten Ersatz für Spiro-OMeTAD dar, mit einer prognostizierten Erhöhung des erreichbaren Tandem-Solarzellenwirkungsgrad um 2,9% relativ auf 26,5% absolut. Die Ergebnisse stellen zudem einen Leitfaden zur weiteren Effizienzsteigerung der Tandemsolarzellen-Technologie dar. KW - perovskite KW - silicon KW - tandem solar cell KW - interface engineering KW - contact layers KW - Perowskit KW - Silizium KW - Tandem-Solarzelle KW - Interface-Engineering KW - Kontaktschichten Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426428 ER - TY - THES A1 - Fuchs, Matthias T1 - Soil organic carbon and nitrogen pools in thermokarst-affected permafrost terrain Y1 - 2019 ER - TY - THES A1 - Beamish, Alison Leslie T1 - Hyperspectral remote sensing of the spatial and temporal heterogeneity of low Arctic vegetation T1 - Hyperspektrale Fernerkundung der räumlichen und zeitlichen Heterogenität niedriger arktischer Vegetation BT - the role of phenology, vegetation colour, and intrinsic ecosystem components BT - die Rolle von Phänologie, Vegetationsfarbe und intrinsischer Ökosystemkomponenten N2 - Arctic tundra ecosystems are experiencing warming twice the global average and Arctic vegetation is responding in complex and heterogeneous ways. Shifting productivity, growth, species composition, and phenology at local and regional scales have implications for ecosystem functioning as well as the global carbon and energy balance. Optical remote sensing is an effective tool for monitoring ecosystem functioning in this remote biome. However, limited field-based spectral characterization of the spatial and temporal heterogeneity limits the accuracy of quantitative optical remote sensing at landscape scales. To address this research gap and support current and future satellite missions, three central research questions were posed: • Does canopy-level spectral variability differ between dominant low Arctic vegetation communities and does this variability change between major phenological phases? • How does canopy-level vegetation colour images recorded with high and low spectral resolution devices relate to phenological changes in leaf-level photosynthetic pigment concentrations? • How does spatial aggregation of high spectral resolution data from the ground to satellite scale influence low Arctic tundra vegetation signatures and thereby what is the potential of upcoming hyperspectral spaceborne systems for low Arctic vegetation characterization? To answer these questions a unique and detailed database was assembled. Field-based canopy-level spectral reflectance measurements, nadir digital photographs, and photosynthetic pigment concentrations of dominant low Arctic vegetation communities were acquired at three major phenological phases representing early, peak and late season. Data were collected in 2015 and 2016 in the Toolik Lake Research Natural Area located in north central Alaska on the North Slope of the Brooks Range. In addition to field data an aerial AISA hyperspectral image was acquired in the late season of 2016. Simulations of broadband Sentinel-2 and hyperspectral Environmental and Mapping Analysis Program (EnMAP) satellite reflectance spectra from ground-based reflectance spectra as well as simulations of EnMAP imagery from aerial hyperspectral imagery were also obtained. Results showed that canopy-level spectral variability within and between vegetation communities differed by phenological phase. The late season was identified as the most discriminative for identifying many dominant vegetation communities using both ground-based and simulated hyperspectral reflectance spectra. This was due to an overall reduction in spectral variability and comparable or greater differences in spectral reflectance between vegetation communities in the visible near infrared spectrum. Red, green, and blue (RGB) indices extracted from nadir digital photographs and pigment-driven vegetation indices extracted from ground-based spectral measurements showed strong significant relationships. RGB indices also showed moderate relationships with chlorophyll and carotenoid pigment concentrations. The observed relationships with the broadband RGB channels of the digital camera indicate that vegetation colour strongly influences the response of pigment-driven spectral indices and digital cameras can track the seasonal development and degradation of photosynthetic pigments. Spatial aggregation of hyperspectral data from the ground to airborne, to simulated satel-lite scale was influenced by non-photosynthetic components as demonstrated by the distinct shift of the red edge to shorter wavelengths. Correspondence between spectral reflectance at the three scales was highest in the red spectrum and lowest in the near infra-red. By artificially mixing litter spectra at different proportions to ground-based spectra, correspondence with aerial and satellite spectra increased. Greater proportions of litter were required to achieve correspondence at the satellite scale. Overall this thesis found that integrating multiple temporal, spectral, and spatial data is necessary to monitor the complexity and heterogeneity of Arctic tundra ecosystems. The identification of spectrally similar vegetation communities can be optimized using non-peak season hyperspectral data leading to more detailed identification of vegetation communities. The results also highlight the power of vegetation colour to link ground-based and satellite data. Finally, a detailed characterization non-photosynthetic ecosystem components is crucial for accurate interpretation of vegetation signals at landscape scales. N2 - Die arktische Erwärmung beeinflusst Produktivität, Wachstums, Artenzusammensetzung, Phänologie und den Reproduktionserfolg arktischer Vegetation, mit Auswirkungen auf die Ökosystemfunktionen sowie auf den globalen Kohlenstoff- und Energiehaushalt. Feldbasierte Messungen und spektrale Charakterisierungen der räumlichen und zeitlichen Heterogenität arktischer Vegetationsgemeinschaften sind limitiert und die Genauigkeit fernerkundlicher Methoden im Landschaftsmaßstab eingeschränkt. Um diese Forschungslücke zu schließen und aktuelle und zukünftige Satellitenmissionen zu unterstützen, wurden drei zentrale Forschungsfragen entwickelt: 1) Wie unterscheidet sich die spektrale Variabilität des Kronendaches zwischen dominanten Vegetationsgemeinschaften der niederen Arktis und wie verändert sich diese Variabilität zwischen den wichtigsten phänologischen Phasen? 2) Wie hängen Aufnahmen der Vegetationsfarbe des Kronendaches von hoch und niedrig auflösenden Geräten mit phänologischen Veränderungen des photosynthetischen Pigmentgehalts auf Blattebene zusammen? 3) Wie beeinflusst die räumliche Aggregation von Daten mit hoher spektraler Auflösung von der Boden- bis zur Satelliten-Skala die arktischen Vegetationssignale der Tundra und welches Potenzial haben zukünftige hyperspektraler Satellitensysteme für die arktische Vegetationscharakterisierung? Zur Beantwortung dieser Fragen wurde eine detaillierte Datenbank aus feldbasierten Daten erstellt und mit hyperspektralen Luftbildern sowie multispektralen Sentinel-2 und simulierten hyperspektralen EnMAP Satellitendaten verglichen. Die Ergebnisse zeigten, dass die Spätsai-son am besten geeignet ist um dominante Vegetationsgemeinschaften mit Hilfe von hyper-spektralen Daten zu identifizieren. Ebenfalls konnte gezeigt werden, dass die mit handelsüb-lichen Digitalkameras aufgenommene Vegetationsfarbe pigmentgesteuerte Spektralindizes stark beeinflusst und den Verlauf von photosynthetischen Pigmenten nachverfolgen kann. Die räumliche Aggregation hyperspektraler Daten von der Boden- über die Luft- zur Satelli-tenskala wurde durch nicht-photosynthetische Komponenten beeinflusst und die spektralen Reflexionsvermögen der drei Skalen stimmten im roten Spektrum am höchsten und im nahen Infrarotbereich am niedrigsten überein. Die vorliegende Arbeit zeigt, dass die Integration zeitlicher, spektraler und räumlicher Daten notwendig ist, um Komplexität und Heterogenität arktischer Vegetationsreaktionen in Reaktion auf klimatische Veränderungen zu überwachen. KW - hyperspectral remote sensing KW - Arctic tundra KW - vegetation KW - imaging spectroscopy KW - hyperspektral Fernerkundung KW - arktische Tundra KW - Vegetation KW - Spektroskopie Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425922 ER - TY - GEN A1 - Perkins, Daniel M. A1 - Perna, Andrea A1 - Adrian, Rita A1 - Cermeño, Pedro A1 - Gaedke, Ursula A1 - Huete-Ortega, Maria A1 - White, Ethan P. A1 - Yvon-Durocher, Gabriel T1 - Energetic equivalence underpins the size structure of tree and phytoplankton communities T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The size structure of autotroph communities – the relative abundance of small vs. large individuals – shapes the functioning of ecosystems. Whether common mechanisms underpin the size structure of unicellular and multicellular autotrophs is, however, unknown. Using a global data compilation, we show that individual body masses in tree and phytoplankton communities follow power-law distributions and that the average exponents of these individual size distributions (ISD) differ. Phytoplankton communities are characterized by an average ISD exponent consistent with three-quarter-power scaling of metabolism with body mass and equivalence in energy use among mass classes. Tree communities deviate from this pattern in a manner consistent with equivalence in energy use among diameter size classes. Our findings suggest that whilst universal metabolic constraints ultimately underlie the emergent size structure of autotroph communities, divergent aspects of body size (volumetric vs. linear dimensions) shape the ecological outcome of metabolic scaling in forest vs. pelagic ecosystems. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 684 KW - general quantitative theory KW - cell-size KW - forest structure KW - scaling relationships KW - marine-phytoplankton KW - metabolic ecology KW - distributions KW - abundance KW - biomass KW - allometry Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425695 SN - 1866-8372 IS - 684 ER - TY - THES A1 - Pohlenz, Julia T1 - Structural insights into sodium-rich silicate - carbonate glasses and melts T1 - Strukturelle Eigenschaften von natriumreichen silikatisch-karbonatischen Gläsern und Schmelzen mittels in-situ XAFS an Spurenelementen und Molekular Dynamik BT - a combined study of trace element in-situ XAFS and Molecular Dynamics N2 - Carbonate-rich silicate and carbonate melts play a crucial role in deep Earth magmatic processes and their melt structure is a key parameter, as it controls physical and chemical properties. Carbonate-rich melts can be strongly enriched in geochemically important trace elements. The structural incorporation mechanisms of these elements are difficult to study because such melts generally cannot be quenched to glasses, which are usually employed for structural investigations. This thesis investigates the influence of CO2 on the local environments of trace elements contained in silicate glasses with variable CO2 concentrations as well as in silicate and carbonate melts. The compositions studied include sodium-rich peralkaline silicate melts and glasses and carbonate melts similar to those occurring naturally at Oldoinyo Lengai volcano, Tanzania. The local environments of the three elements yttrium (Y), lanthanum (La) and strontium (Sr) were investigated in synthesized glasses and melts using X-ray absorption fine structure (XAFS) spectroscopy. Especially extended X-ray absorption fine structure spectroscopy (EXAFS) provides element specific information on local structure, such as bond lengths, coordination numbers and the degree of disorder. To cope with the enhanced structural disorder present in glasses and melts, EXAFS analysis was based on fitting approaches using an asymmetric distribution function as well as a correlation model according to bond valence theory. Firstly, silicate glasses quenched from high pressure/temperature melts with up to 7.6 wt % CO2 were investigated. In strongly and extremely peralkaline glasses the local structure of Y is unaffected by the CO2 content (with oxygen bond lengths of ~ 2.29 Å). Contrary, the bond lengths for Sr-O and La-O increase with increasing CO2 content in the strongly peralkaline glasses from ~ 2.53 to ~ 2.57 Å and from ~ 2.52 to ~ 2.54 Å, respectively, while they remain constant in extremely peralkaline glasses (at ~ 2.55 Å and 2.54 Å, respectively). Furthermore, silicate and unquenchable carbonate melts were investigated in-situ at high pressure/temperature conditions (2.2 to 2.6 GPa, 1200 to 1500 °C) using a Paris-Edinburgh press. A novel design of the pressure medium assembly for this press was developed, which features increased mechanical stability as well as enhanced transmittance at relevant energies to allow for low content element EXAFS in transmission. Compared to glasses the bond lengths of Y-O, La-O and Sr-O are elongated by up to + 3 % in the melt and exhibit higher asymmetric pair distributions. For all investigated silicate melt compositions Y-O bond lengths were found constant at ~ 2.37 Å, while in the carbonate melt the Y-O length increases slightly to 2.41 Å. The La-O bond lengths in turn, increase systematically over the whole silicate – carbonate melt joint from 2.55 to 2.60 Å. Sr-O bond lengths in melts increase from ~ 2.60 to 2.64 Å from pure silicate to silicate-bearing carbonate composition with constant elevated bond length within the carbonate region. For comparison and deeper insight, glass and melt structures of Y and Sr bearing sodium-rich silicate to carbonate compositions were simulated in an explorative ab initio molecular dynamics (MD) study. The simulations confirm observed patterns of CO2-dependent local changes around Y and Sr and additionally provide further insights into detailed incorporation mechanisms of the trace elements and CO2. Principle findings include that in sodium-rich silicate compositions carbon either is mainly incorporated as a free carbonate-group or shares one oxygen with a network former (Si or [4]Al) to form a non-bridging carbonate. Of minor importance are bridging carbonates between two network formers. Here, a clear preference for two [4]Al as adjacent network formers occurs, compared to what a statistical distribution would suggest. In C-bearing silicate melts minor amounts of molecular CO2 are present, which is almost totally dissolved as carbonate in the quenched glasses. The combination of experiment and simulation provides extraordinary insights into glass and melt structures. The new data is interpreted on the basis of bond valence theory and is used to deduce potential mechanisms for structural incorporation of investigated elements, which allow for prediction on their partitioning behavior in natural melts. Furthermore, it provides unique insights into the dissolution mechanisms of CO2 in silicate melts and into the carbonate melt structure. For the latter, a structural model is suggested, which is based on planar CO3-groups linking 7- to 9-fold cation polyhedra, in accordance to structural units as found in the Na-Ca carbonate nyerereite. Ultimately, the outcome of this study contributes to rationalize the unique physical properties and geological phenomena related to carbonated silicate-carbonate melts. N2 - Karbonatische und karbonatreiche silikatische Schmelzen spielen eine entscheidende Rolle in den magmatischen Prozessen der Erde. Die interne Schmelzstruktur bestimmt dabei maßgeblich ihre physikalischen und chemischen Eigenschaften. Karbonatreiche Schmelzen können sehr stark mit geochemisch wichtigen Spurenelementen angereichert sein. Die strukturellen Einbaumechanismen sind jedoch kaum verstanden, da diese Schmelzen nicht zu homogenen Gläsern abgeschreckt werden können, welche üblicherweise für strukturelle Untersuchungen genutzt werden. Die vorliegende Arbeit widmet sich dem Einfluss von CO2 auf die lokale Umgebung von ausgewählten Spurenelementen in karbonathaltigen silikatischen Gläsern sowie silikatisch bis karbonatischen Schmelzen. Untersucht werden natriumreiche, stark bis extrem peralkaline silikatische und karbonatische Zusammensetzungen, wie sie vom Vulkan Oldoinyo Lengai, Tansania, bekannt sind. Zum einen werden die lokale Umgebungen von Yttrium (Y), Lanthan (La) und Strontium (Sr) in synthetisierten Gläsern und Schmelzen mit Röntgen-Absorption-Feinstruktur-Spektroskopie (engl. X-ray absorption fine structure (XAFS) spectroscopy) untersucht. Insbesondere extended X-ray absorption fine structure (EXAFS) spectroscopy liefert elementspezifisch strukturelle Informationen über Bindungslängen, Koordinationszahlen und Ordnungsgrad. Dem hohen Grad struktureller Unordnung in Gläsern und Schmelzen wird in den vorliegenden EXAFS-Analysen mit der Verwendung einer asymmetrischen Verteilungsfunktion und eines Korrelationsmodells, basierend auf der Bindungsvalenztheorie, Rechnung getragen. Für silikatische Gläser mit steigendem CO2-Gehalt zwischen 0 und bis zu 7,6 Gew.-% ist festzustellen: (1) Konstante Bindungslängen für Sr-O (~ 2,55 Å) und La-O (~ 2,54 Å) in extrem peralkaliner Zusammensetzung, sowie für Y-O (~ 2,29 Å) in stark und extrem peralkaliner Zusammensetzung. (2) Zunehmende Bindungslängen für Sr-O (~ von 2,53 auf 2,57 Å) und La-O in stark peralkaliner Zusammensetzung (~ von 2,52 auf 2,54 Å). Weiterhin werden silikatische sowie nicht-abschreckbare karbonatische Schmelzen in-situ unter hohem Druck und hoher Temperatur (2,2 bis 2,6 GPa, 1200 bis 1500 °C, untersucht in einer Paris-Edinburgh-Presse) analysiert. Ein neu entwickelter Aufbau des Druckübertragungsmediums garantiert eine hohe mechanische Festigkeit und ermöglicht aufgrund hervorragender Transmissivität im relevanten Energiebereich Transmissions-EXAFS an niedrigkonzentrierten Elementen. Im Vergleich zu den Gläsern zeigen die Schmelzen generell ~ 3 % höhere Y-O-, La-O-, und Sr-O-Bindungslängen und eine erhöhte Asymmetrie in der Paarverteilung. In silikatischen Schmelzen sind Y-O-Bindungslängen konstant (~ 2,37 Å), wohingegen sie in karbonatischen Schmelzen zunehmen (bis zu 2,41 Å). La-O-Abstände vergrößern sich systematisch von silikatischen zu karbonatischen Schmelzen (von 2,55 auf 2,60 Å). Sr-O-Abstände steigen von 2,60 auf 2,64 Å in silikatischen Zusammensetzungen mit steigendem CO2-Gehalt und sind für alle karbonatischen Zusammensetzungen konstant. Zum Vergleich und besserem Verständnis wurden Y- und Sr-haltige, silikatische und karbonatische Glas- und Schmelzstrukturen in einer explorativen ab-initio Molekular Dynamik (MD) Studie simuliert. Die MD-Studie bestätigt die CO2-abhängigen lokalen Veränderungen um Y und Sr und liefert zusätzliche Einblicke in silikatische und karbonatische Glas- und Schmelzstrukturen. In natriumreicher silikatischer Zusammensetzung wird CO2 hauptsächlich als freie Karbonatgruppe eingebaut oder teilt sich als nicht-brückenbildendes Karbonat genau ein Sauerstoffatom mit einem Netzwerkbildner (Si oder [4]Al). Seltener tritt es als brückenbildendes Karbonat zwischen zwei Netzwerkbildnern auf; dabei allerdings mit einer gegenüber der statistischen Verteilung deutlich erhöhten Präferenz für zwei [4]Al als anliegende Netzwerkbildner. C-haltige Schmelzen weisen geringe Mengen an molekularem CO2 auf, welches in den abgeschreckten Gläsern fast vollständig als Karbonat gelöst ist. Die Kombination aus Experiment und Simulation gewährt außerordentliche Einblicke in nur schwierig zu untersuchende Glas- und Schmelzstrukturen. Die gewonnenen Daten werden auf Grundlage der Bindungsvalenztheorie gedeutet und hinsichtlich potentieller Mechanismen des strukturellen Spurenelementeinbaus sowie dem daraus ableitbaren Fraktionierungsverhalten in natürlichen Schmelzen diskutiert. Neue Erkenntnisse über den strukturellen CO2-Einbau werden genutzt, um ein Strukturmodell für karbonatische Schmelzen abzuleiten. Dieses basiert auf der Verknüpfung von 7- bis 9-fach koordinierten Kationenpolyedern durch die planaren Karbonat-Gruppen, ähnlich wie es im Na-Ca-Karbonat Nyerereite zu beobachten ist. Letztendlich leisten die Erkenntnisse der Arbeit somit ihren Beitrag, das Verständnis um die einzigartigen physikalischen Eigenschaften und geologischen Phänomene dieser Schmelzen zu vertiefen. KW - glass structure KW - melt structure KW - X-ray absorption spectroscopy KW - Glasstruktur KW - Schmelzstruktur KW - Röntgenabsorptionsspektroskopie Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-423826 ER - TY - RPRT A1 - Krieger, Heike A1 - Liese, Andrea Margit T1 - A Metamorphosis of International Law? BT - Value changes in the international legal order from the perspectives of legal and political science T2 - KFG Working Paper Series N2 - The paper aims to lay out a framework for evaluating value shifts in the international legal order for the purposes of a forthcoming book. In view of current contestations it asks whether we are observing yet another period of norm change (Wandel) or even a more fundamental transformation of international law – a metamorphosis (Verwandlung). For this purpose it suggests to look into the mechanisms of how norms change from the perspective of legal and political science and also to approximate a reference point where change turns into metamorphosis. It submits that such a point may be reached where specific legally protected values are indeed changing (change of legal values) or where the very idea of protecting certain values through law is renounced (delegalizing of values). The paper discusses the benefits of such an interdisciplinary exchange and tries to identify differences and commonalities among both disciplinary perspectives. T3 - KFG Working Paper Series - 27 Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426088 IS - 27 ER - TY - THES A1 - Bielefeldt, Jonas T1 - Toward Service-based Value Creation BT - The Role of Service Business Development in Manufacturing Companies T2 - Schriftenreihe zum Business Development ; 7 N2 - Over the past decade, society has witnessed an increasing expansion of service economies as manufacturing (i.e., product-oriented) companies break free from their product-based business model and move toward more service-oriented value creation as a result of several economic, technological, and social changes. As they shift from products to (service) solutions, manufacturing companies pursue new strategic direction, inter alia, by extensively employing service business development activities. The objective of this dissertation is to investigate the considerable (re-)emerging stream of service business development by providing vital insights for academia and management into important focus areas that have hardly, if at all, been (empirically) investigated in the existing literature before. Therefore, these findings can be vital to informing a differentiation in current and future marketing strategies in business practice. First of all, this dissertation focuses on the extent to which service business development is transposed into business practice. Because scarce empirical-quantitative research has studied the current state of service business development across various industry and market sectors, this study analyzes a unique, manually collected dataset of 266 (product and service) business development activities. In so doing, this investigation contributes to literature by presenting a comprehensive, industry-wide status quo and trend report of service business development in practice. Furthermore, given the surprisingly limited scientific attention paid to the question of how service business development is strategically configured and further applied to different environmental circumstances, this dissertation provides comprehensive theoretical and practical implications by analyzing in detail a sample of 137 service business developments of 66 product-oriented companies. Lastly, manufacturers are recognizing that service-oriented value creation is moving toward a more collaborative process of co-creation as a promising measure to achieve competitive advantage, and even more as an appropriate response to complex business environments. Thus, an increasing number of companies around the world have recently introduced business models related to access-based services such as car-, scooter-, and bike-sharing systems. But despite the considerable advantages of access-based services as an alternative to ownership, these companies are now seeing that consumer adoption and (re-)usage rates remain insufficient. Owing to the lack of general and cross-national scientific knowledge, the purpose of this dissertation continues to explore which factors impede diffusion of related service business development activities from a consumer perspective and what kind of differences can be established between countries. Consequently, with a total of 1,443 participants, a cross-national survey was carried out in three countries, i.e., the United States, Germany, and China, to measure a vast number of different adoption barriers derived from a developed integrated framework that combines established theories within innovation and adoption behavior research. Y1 - 2019 SN - 978-3-339-10642-1 PB - Kovac CY - Hamburg ER - TY - JOUR A1 - Kriegerowski, Marius A1 - Cesca, Simone A1 - Ohrnberger, Matthias A1 - Dahm, Torsten A1 - Krüger, Frank T1 - Event couple spectral ratio Q method for earthquake clusters BT - application to northwest Bohemia JF - Solid Earth N2 - We develop an amplitude spectral ratio method for event couples from clustered earthquakes to estimate seismic wave attenuation (Q-1) in the source volume. The method allows to study attenuation within the source region of earthquake swarms or aftershocks at depth, independent of wave path and attenuation between source region and surface station. We exploit the high-frequency slope of phase spectra using multitaper spectral estimates. The method is tested using simulated full wave-field seismograms affected by recorded noise and finite source rupture. The synthetic tests verify the approach and show that solutions are independent of focal mechanisms but also show that seismic noise may broaden the scatter of results. We apply the event couple spectral ratio method to northwest Bohemia, Czech Republic, a region characterized by the persistent occurrence of earthquake swarms in a confined source region at mid-crustal depth. Our method indicates a strong anomaly of high attenuation in the source region of the swarm with an averaged attenuation factor of Qp < 100. The application to S phases fails due to scattered P-phase energy interfering with S phases. The Qp anomaly supports the common hypothesis of highly fractured and fluid saturated rocks in the source region of the swarms in northwest Bohemia. However, high temperatures in a small volume around the swarms cannot be excluded to explain our observations. KW - west bohemia KW - attenuation tomography KW - swarm earthquakes KW - focal zone KW - parameters KW - locations KW - fault Y1 - 2019 U6 - https://doi.org/10.5194/se-10-317-2019 SN - 1869-9529 IS - 10 SP - 317 EP - 328 PB - Copernicus Publications CY - Göttingen ER - TY - RPRT A1 - Letsiou Häusler, Anna A1 - Beckenkamp, Nicolas A1 - Röthlisberger, Livia ED - Weiß, Norman T1 - New Dimensions of an Old Dilemma BT - Hate Speech and Freedom of Expression T2 - Staat, Recht und Politik – Forschungs- und Diskussionspapiere T2 - State, Law, and Politics - Research and Discussion Papers N2 - Unfolding the history of one of the oldest human val-ues, the freedom of expression, while defining its limits, is a complicated task. Does freedom stop where hate starts? This very old dilemma is -now more than ever before- revealing new dimensions. Politicians and new laws aim at regulating free expression, while disagree-ments over such regulation gradually become a source of endless conflict in newly formed multicultural, inter-connected, and digitized societies. The example of the Network Enforcement Act is used to understand the idea of restrictive legal practices in Germany, but also to enlighten the fact that law is a human construction which was created in order to regulate communication among individuals. Alternative practices, to straight legal ones, are summarized to show other dimensions of regulating hate speech without involving top-down approaches. The article proposes the approach of re-storative justice as a combination of legal and medita-tive practices in cases of hate speech. One advantage of the restorative justice approach elaborated in this arti-cle is the potential to remedy the inner hate and the pain, both of the victim and perpetrator. Finally, reveal-ing parts of history and new aspects of the ‘hate speech-puzzle’, leads to a questioning of contemporary social structures that possibly generate hate itself. N2 - Der Schutzbereich und die Grenzen der Meinungsfrei-heit müssen stets auf neue definiert und sie muss ge-gebenenfalls mit anderen Menschenrechten abgewogen werden. Hört die Freiheit dort auf, wo der Hass be-ginnt? Mit neuen Gesetzen zielen Politiker auf die Re-gulierung der freien Meinungsäußerung ab, während Meinungsverschiedenheiten über solche Regulierungen zu einer Quelle endloser Konflikte in neu gebildeten multikulturellen, miteinander verbundenen und digita-lisierten Gesellschaften werden. Am Beispiel des Netz-werkdurchsetzungsgesetzes wird die Idee restriktiver Rechtspraktiken in Deutschland untersucht, aber auch aufgezeigt, dass Recht eine menschliche Konstruktion ist, die geschaffen wurde, um die Kommunikation zwi-schen Individuen zu regeln. Alternative, nicht aus-schließlich juristische Praktiken werden zusammenge-fasst, um andere Dimensionen der Regulierung von Hassreden aufzuzeigen, die ohne Top-down-Ansätze auskommen. Wir schlagen den Ansatz der restorativen Gerechtigkeit als eine Kombination aus rechtlichen und meditativen Praktiken in Fällen von Hassrede vor. Ein Vorteil des in diesem Artikel erarbeiteten restaurativen Gerechtigkeitsansatzes ist das Potenzial, den inneren Hass und den Schmerz von Opfern und Tätern zu beseitigen. T3 - Staat, Recht und Politik – Forschungs- und Diskussionspapiere = State, Law, and Politics - Research and Discussion Papers - 7 KW - Freedom of expression KW - Hate speech Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-424869 SN - 2509-6974 IS - 7 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - THES A1 - Eckert, Sebastian T1 - Accessing active sites of molecular proton dynamics N2 - The unceasing impact of intense sunlight on earth constitutes a continuous source of energy fueling countless natural processes. On a molecular level, the energy contained in the electromagnetic radiation is transferred through photochemical processes into chemical or thermal energy. In the course of such processes, photo-excitations promote molecules into thermally inaccessible excited states. This induces adaptations of their molecular geometry according to the properties of the excited state. Decay processes towards energetically lower lying states in transient molecular geometries result in the formation of excited state relaxation pathways. The photo-chemical relaxation mechanisms depend on the studied system itself, the interactions with its chemical environment and the character of the involved states. This thesis focuses on systems in which photo-induced deprotonation processes occur at specific atomic sites. To detect these excited-state proton dynamics at the affected atoms, a local probe of molecular electronic structure is required. Therefore, site-selective and orbital-specific K-edge soft X-ray spectroscopy techniques are used here to detect photo-induced proton dynamics in gaseous and liquid sample environments. The protonation of nitrogen (N) sites in organic molecules and the oxygen (O) atom in the water molecule are probed locally through transitions between 1s orbitals and the p-derived molecular valence electronic structure. The used techniques are X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS). Both yield access to the unoccupied local valence electronic structure, whereas the latter additionally probes occupied states. We apply these probes in optical pump X-ray probe experiments to investigate valence excited-state proton transfer capabilities of aqueous 2-thiopyridone. A characteristic shift of N K-edge X-ray absorption resonances as well as a distinct X-ray emission line are established by us as spectral fingerprints of N deprotonation in the system. We utilize them to identify photo-induced N deprotonation of 2-thiopyridone on femtosecond timescales, in optical pump N K-edge RIXS probe measurements. We further establish excited state proton transfer mechanisms on picosecond and nanosecond timescales along the dominant relaxation pathways of 2-thiopyridone using transient N K-edge XAS. Despite being an excellent probe mechanism for valence excited-state proton dynamics, the K-edge core-excitation itself also disturbs the electronic structure at specific sites of a molecule. The rapid reaction of protons to 1s photo-excitations can yield directional structural distortions within the femtosecond core-excited state lifetime. These directional proton dynamics can change the energetic separation of eigenstates of the system and alter probabilities for radiative decay between them. Both effects yield spectral signatures of the dynamics in RIXS spectra. Using these signatures of RIXS transitions into electronically excited states, we investigate proton dynamics induced by N K-edge excitation in the amino-acid histidine. The minor core-excited state dynamics of histidine in basic and neutral chemical environments allow us to establish XAS and RIXS spectral signatures of different N protonation states at its imidazole N sites. Based on these signatures, we identify an excitation-site-independent N-H dissociation for N K-edge excitation under acidic conditions. Such directional structural deformations, induced by core-excitations, also make proton dynamics in electronic ground states accessible through RIXS transitions into vibrationally excited states. In that context, we interpret high resolution RIXS spectra of the water molecule for three O K-edge resonances based on quantum-chemical wave packet propagation simulations. We show that highly oriented ground state vibrational modes of coupled nuclear motion can be populated through RIXS processes by preparation of core-excited state nuclear wave packets with the same directionality. Based on that, we analytically derive the possibility to extract one-dimensional directional cuts through potential energy surfaces of molecular systems from the corresponding RIXS spectra. We further verify this concept through the extraction of the gas-phase water ground state potential along three coordinates from experimental data in comparison to quantum-chemical simulations of the potential energy surface. This thesis also contains contributions to instrumentation development for investigations of photo-induced molecular dynamics at high brilliance X-ray light sources. We characterize the setup used for the transient valence-excited state XAS measurements of 2-thiopyridone. Therein, a sub-micrometer thin liquid sample environment is established employing in-vacuum flat-jet technology, which enables a transmission experimental geometry. In combination with a MHz-laser system, we achieve a high detection sensitivity for photo-induced X-ray absorption changes. Additionally, we present conceptual improvements for temporal X-ray optical cross-correlation techniques based on transient changes of multilayer optical properties, which are crucial for the realization of femtosecond time-resolved studies at synchrotrons and free-electron lasers. N2 - Die stetige Bestrahlung der Erde mit intensivem Sonnenlicht stellt einen permanente Energiequelle dar, die zahllose natürliche Prozesse antreibt. Auf molekularer Ebene wird die Energie der elektromagnetischen Strahlung durch photochemische Prozesse in chemische und thermische Energie umgewandelt. Während dieser Prozesse werden thermisch nicht erreichbare angeregte Zustände von Molekülen durch Photoanregungen bevölkert. Dies führt zu Änderungen der Molekülgeometrie, die abhängig von den Eigenschaften der angeregten Zustände sind. Zerfallsprozesse in energetisch tieferliegende Zustände in transienten Molekülgeometrien führen zur Ausbildung von Relaxationspfaden angeregter Zustände. Die Relaxationsmechanismen sind dabei abhängig vom untersuchten System selbst, den Wechselwirkungen mit seiner chemischen Umgebung und den Eigenschaften der beteiligten angeregten Zustände. In dieser Arbeit werden Systeme untersucht, in denen die Protonierung bestimmter Atome im Molekül durch eine Photoanregung geändert werden kann. Um Protonendynamik an den betreffenden Atomen zu untersuchen, wird ein lokaler Zugang zur elektronischen Struktur des Moleküls benötigt. Daher wird in dieser Arbeit K-Kanten Weichröntgenspektroskopie genutzt, um photo-induzierte Protonendynamik in gasförmigen und flüssigen Proben zu untersuchen. Zusätzlich zur Selektivität bzgl. des Elements und des chemischen Zustands des betreffenden Atoms bietet diese Zugang zum Charakter und zur Lokalisierung der bindungsformenden Valenzorbitale. Die Protonierung von Stickstoffatomen (N) in organischen Systemen und die des Sauerstoffatoms (O) im Wassermolekül wird dabei durch Übergänge zwischen stark lokalisierten 1s- und Valenzorbitalen mit 2p-Charakter detektiert. Die verwendeten Spektroskopiemethoden Röntgenabsorption (engl. X-ray absorption spectroscopy, XAS) und resonate inelastische Röntgenstreuung (engl. resonant inelastic X-ray scattering, RIXS) bieten dabei einen lokalen Zugang zur unbesetzten bzw. im Fall von RIXS auch zur besetzten elektronischen Struktur der untersuchten Moleküle. Mit Hilfe der genannten Methoden haben wir in zeitaufgelösten Anrege-Abfrage (engl. pump-probe) Experimenten durch Valenzanregungen induzierte Protonentransfer-Prozesse (engl. excited state proton transfer, ESPT) des Moleküls 2-Thiopyridon in wässriger Lösung untersucht. Eine Verschiebung der N K-Kanten Röntgenabsorptionsresonanzen, sowie eine charakteristische Röntgenemissionslinie werden von uns als spektrale Signaturen einer N Deprotonierung des Systems etabliert. Eine potenzielle photo-induzierte N Deprotonierung des Moleküls wird anhand dieser Signaturen auf femtosekunden Zeitskalen über zeitaufgelöste N K-Kanten RIXS Messungen identifiziert. Protonentransfer-Mechanismen auf Pico- und Nanosekunden Zeitskalen entlang der dominanten Relaxationspfade des Systems werden mit zeitaufgelöstem N K-Kanten XAS untersucht. K-Kanten Rumpfanregungen eignen sich nicht nur ideal zur Detektion von Protonendynamik in valenzangeregten Zuständen, da die Rumpfanregungen selbst auch eine lokalisierte Störung der elektronischen Struktur darstellen. Vor allem die Reaktion von Protonen auf diese Störung innerhalb der 1s Rumpfloch-Lebensdauer von wenigen Femtosekunden kann zu einer gerichteten Verzerrung der Molekülstruktur führen. Die damit verbundenen Änderungen von Übergangsenergien und -wahrscheinlichkeiten sind als Signaturen dieser gerichteten Protonendynamik in RIXS Spektren zugänglich. Anhand von RIXS Übergängen in elektronisch angeregte Zustände untersuchen wir Protonendynamik, die durch N K-Kanten Anregungen an den N Atomen im Imidazolring der Aminosäure Histidin induziert wird. Die schwache Dynamik in basischen und neutralen wässrigen Lösungen erlauben es uns, die Protonierung dieser N Atome mit charakteristischen spektralen Signaturen zu korrelieren. Mit Hilfe dieser Signaturen identifizieren wir eine durch K-Kanten Anregung verursachte N-H Dissoziation in saurer Lösung. Dieser Prozess ist unabhängig davon, an welchem der N Atome des Imidazolrings die Rumpfanregung lokalisiert ist. Solche, durch Rumpfanregungen verursachten, gerichteten Verzerrungen der Molekülstruktur ermöglichen einen Zugang zu Protonendynamik im elektronischen Grundzustand über RIXS Prozesse in dessen vibrationsangeregte Zustände. In diesem Zusammenhang vergleichen wir hochaufgelöste O K-Kanten RIXS Spektren des Wassermoleküls in der Gasphase mit quantenchemischen Simulationen zur Wellenpaketpropagation in den rumpfangeregten Zuständen. Dabei wird deutlich, dass die gerichtete Verzerrung der Molekülstruktur im rumpfangeregten Zustand eine Bevölkerung von Vibrationsmoden des Grundzustandes mit der gleichen Ausrichtung durch den RIXS Prozess verursacht. Anhand dieser Ergebnisse leiten wir ab, unter welchen Bedingungen eine Extraktion eindimensionaler Querschnitte der Potentialfläche des Grundzustandes aus den entsprechenden RIXS Spektren möglich ist. Wir verifizieren diese Methode anhand der Extraktion der Grundzustandspotentialfläche des Wassermoleküls entlang drei unterschiedlicher Richtungen im Vergleich zu den quantenchemischen Rechnungen. Diese Arbeit enthält zudem Beiträge zur Entwicklung von Instrumentierung für Untersuchungen valenzangeregter Moleküldynamik an Röntgenquellen mit hoher Brillianz. Der experimentelle Aufbau, der für die zeitaufgelösten XAS Messungen an 2-Thiopyridon verwendet wurde, wird vorgestellt. Ein sub-Mikrometer dünner Flüssigkeitsflachstrahl erlaubt dabei Messungen in einer Transmissionsgeometrie. In Kombination mit einem MHz-Lasersystem können transiente Absorptionsänderungen effizient detektiert werden. Zudem präsentieren wir Konzepte zur zeitlichen Korrelation von Röntgen- und optischen Lichtpulsen, basierend auf Änderungen der optischen Eigenschaften von Dünnschichtsystemen, die essenziell für Studien transienter Prozesse an Synchrotrons und Freie-Elektronen Lasern mit Femtosekunden Zeitauflösung sind. KW - molecular proton dynamics KW - Protonendynamik molekularer Systeme KW - K-edge soft X-ray spectroscopy KW - K-Kanten Weichröntgenspektroskopie KW - excited state proton transfer KW - Protonentransfer in angeregten Zuständen KW - core-excited state dynamics KW - Dynamik in rumpfangeregten Zuständen KW - optical pump - X-ray probe spectroscopy KW - Kurzzeitspektroskopie mit optischer Anregung und Röntgendetektion Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425870 ER - TY - GEN A1 - Grafe, Marianne A1 - Batsios, Petros A1 - Meyer, Irene A1 - Lisin, Daria A1 - Baumann, Otto A1 - Goldberg, Martin W. A1 - Gräf, Ralph T1 - Supramolecular Structures of the Dictyostelium Lamin NE81 T2 - Potsprint der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Nuclear lamins are nucleus-specific intermediate filaments (IF) found at the inner nuclear membrane (INM) of the nuclear envelope (NE). Together with nuclear envelope transmembrane proteins, they form the nuclear lamina and are crucial for gene regulation and mechanical robustness of the nucleus and the whole cell. Recently, we characterized Dictyostelium NE81 as an evolutionarily conserved lamin-like protein, both on the sequence and functional level. Here, we show on the structural level that the Dictyostelium NE81 is also capable of assembling into filaments, just as metazoan lamin filament assemblies. Using field-emission scanning electron microscopy, we show that NE81 expressed in Xenopous oocytes forms filamentous structures with an overall appearance highly reminiscent of Xenopus lamin B2. The in vitro assembly properties of recombinant His-tagged NE81 purified from Dictyostelium extracts are very similar to those of metazoan lamins. Super-resolution stimulated emission depletion (STED) and expansion microscopy (ExM), as well as transmission electron microscopy of negatively stained purified NE81, demonstrated its capability of forming filamentous structures under low-ionic-strength conditions. These results recommend Dictyostelium as a non-mammalian model organism with a well-characterized nuclear envelope involving all relevant protein components known in animal cells. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 682 KW - lamin KW - NE81 KW - Dictyostelium KW - nuclear envelope KW - nuclear lamina KW - expansion microscopy Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425976 SN - 1866-8372 IS - 682 ER - TY - JOUR A1 - Grafe, Marianne A1 - Batsios, Petros A1 - Meyer, Irene A1 - Lisin, Daria A1 - Baumann, Otto A1 - Goldberg, Martin W. A1 - Gräf, Ralph T1 - Supramolecular Structures of the Dictyostelium Lamin NE81 JF - Cells N2 - Nuclear lamins are nucleus-specific intermediate filaments (IF) found at the inner nuclear membrane (INM) of the nuclear envelope (NE). Together with nuclear envelope transmembrane proteins, they form the nuclear lamina and are crucial for gene regulation and mechanical robustness of the nucleus and the whole cell. Recently, we characterized Dictyostelium NE81 as an evolutionarily conserved lamin-like protein, both on the sequence and functional level. Here, we show on the structural level that the Dictyostelium NE81 is also capable of assembling into filaments, just as metazoan lamin filament assemblies. Using field-emission scanning electron microscopy, we show that NE81 expressed in Xenopous oocytes forms filamentous structures with an overall appearance highly reminiscent of Xenopus lamin B2. The in vitro assembly properties of recombinant His-tagged NE81 purified from Dictyostelium extracts are very similar to those of metazoan lamins. Super-resolution stimulated emission depletion (STED) and expansion microscopy (ExM), as well as transmission electron microscopy of negatively stained purified NE81, demonstrated its capability of forming filamentous structures under low-ionic-strength conditions. These results recommend Dictyostelium as a non-mammalian model organism with a well-characterized nuclear envelope involving all relevant protein components known in animal cells. KW - lamin KW - NE81 KW - Dictyostelium KW - nuclear envelope KW - nuclear lamina KW - expansion microscopy Y1 - 2019 U6 - https://doi.org/10.3390/cells8020162 SN - 2073-4409 VL - 8 IS - 2 PB - Molecular Diversity Preservation International CY - Basel ER - TY - GEN A1 - Rawel, Harshadrai Manilal A1 - Huschek, Gerd A1 - Sagu Tchewonpi, Sorel A1 - Homann, Thomas T1 - Cocoa Bean Proteins BT - Characterization, Changes and Modifications due to Ripening and Post-Harvest Processing T2 - Postprints der Universität Potsdam: Mathematisch-Naturwissenschaftliche Reihe N2 - The protein fractions of cocoa have been implicated influencing both the bioactive potential and sensory properties of cocoa and cocoa products. The objective of the present review is to show the impact of different stages of cultivation and processing with regard to the changes induced in the protein fractions. Special focus has been laid on the major seed storage proteins throughout the different stages of processing. The study starts with classical introduction of the extraction and the characterization methods used, while addressing classification approaches of cocoa proteins evolved during the timeline. The changes in protein composition during ripening and maturation of cocoa seeds, together with the possible modifications during the post-harvest processing (fermentation, drying, and roasting), have been documented. Finally, the bioactive potential arising directly or indirectly from cocoa proteins has been elucidated. The “state of the art” suggests that exploration of other potentially bioactive components in cocoa needs to be undertaken, while considering the complexity of reaction products occurring during the roasting phase of the post-harvest processing. Finally, the utilization of partially processed cocoa beans (e.g., fermented, conciliatory thermal treatment) can be recommended, providing a large reservoir of bioactive potentials arising from the protein components that could be instrumented in functionalizing foods. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 681 KW - cocoa processing KW - cocoa proteins KW - classification KW - extraction and characterization methods KW - fermentation-related enzymes KW - bioactive peptides KW - heath potentials KW - protein–phenol interactions Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425953 SN - 1866-8372 IS - 681 ER - TY - JOUR A1 - Rawel, Harshadrai Manilal A1 - Huschek, Gerd A1 - Sagu Tchewonpi, Sorel A1 - Homann, Thomas T1 - Cocoa Bean Proteins BT - Characterization, Changes and Modifications due to Ripening and Post-Harvest Processing JF - Nutrients N2 - The protein fractions of cocoa have been implicated influencing both the bioactive potential and sensory properties of cocoa and cocoa products. The objective of the present review is to show the impact of different stages of cultivation and processing with regard to the changes induced in the protein fractions. Special focus has been laid on the major seed storage proteins throughout the different stages of processing. The study starts with classical introduction of the extraction and the characterization methods used, while addressing classification approaches of cocoa proteins evolved during the timeline. The changes in protein composition during ripening and maturation of cocoa seeds, together with the possible modifications during the post-harvest processing (fermentation, drying, and roasting), have been documented. Finally, the bioactive potential arising directly or indirectly from cocoa proteins has been elucidated. The “state of the art” suggests that exploration of other potentially bioactive components in cocoa needs to be undertaken, while considering the complexity of reaction products occurring during the roasting phase of the post-harvest processing. Finally, the utilization of partially processed cocoa beans (e.g., fermented, conciliatory thermal treatment) can be recommended, providing a large reservoir of bioactive potentials arising from the protein components that could be instrumented in functionalizing foods. KW - cocoa processing KW - cocoa proteins KW - classification KW - extraction and characterization methods KW - fermentation-related enzymes KW - bioactive peptides KW - heath potentials KW - protein–phenol interactions Y1 - 2019 U6 - https://doi.org/10.3390/nu11020428 SN - 2072-6643 VL - 11 IS - 2 PB - Molecular Diversity Preservation International CY - Basel ER - TY - GEN A1 - Wickert, Andrew D. A1 - Schildgen, Taylor F. T1 - Long-profile evolution of transport-limited gravel-bed rivers T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Alluvial and transport-limited bedrock rivers constitute the majority of fluvial systems on Earth. Their long profiles hold clues to their present state and past evolution. We currently possess first-principles-based governing equations for flow, sediment transport, and channel morphodynamics in these systems, which we lack for detachment-limited bedrock rivers. Here we formally couple these equations for transport-limited gravel-bed river long-profile evolution. The result is a new predictive relationship whose functional form and parameters are grounded in theory and defined through experimental data. From this, we produce a power-law analytical solution and a finite-difference numerical solution to long-profile evolution. Steady-state channel concavity and steepness are diagnostic of external drivers: concavity decreases with increasing uplift rate, and steepness increases with an increasing sediment-to-water supply ratio. Constraining free parameters explains common observations of river form: to match observed channel concavities, gravel-sized sediments must weather and fine – typically rapidly – and valleys typically should widen gradually. To match the empirical square-root width–discharge scaling in equilibrium-width gravel-bed rivers, downstream fining must occur. The ability to assign a cause to such observations is the direct result of a deductive approach to developing equations for landscape evolution. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 680 KW - bedrock incision models KW - sediment transport KW - landscape response KW - stream-power KW - alluvial river KW - size distribution KW - channel changes KW - basin geometry KW - grain-size KW - flow Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425718 SN - 1866-8372 IS - 680 ER - TY - GEN A1 - Weithoff, Guntram A1 - Beisner, Beatrix E. T1 - Measures and Approaches in Trait-Based Phytoplankton Community Ecology BT - From Freshwater to Marine Ecosystems T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Trait-based approaches to investigate (short- and long-term) phytoplankton dynamics and community assembly have become increasingly popular in freshwater and marine science. Although the nature of the pelagic habitat and the main phytoplankton taxa and ecology are relatively similar in both marine and freshwater systems, the lines of research have evolved, at least in part, separately. We compare and contrast the approaches adopted in marine and freshwater ecosystems with respect to phytoplankton functional traits. We note differences in study goals relating to functional trait use that assess community assembly and those that relate to ecosystem processes and biogeochemical cycling that affect the type of characteristics assigned as traits to phytoplankton taxa. Specific phytoplankton traits relevant for ecological function are examined in relation to herbivory, amplitude of environmental change and spatial and temporal scales of study. Major differences are identified, including the shorter time scale for regular environmental change in freshwater ecosystems compared to that in the open oceans as well as the type of sampling done by researchers based on site-accessibility. Overall, we encourage researchers to better motivate why they apply trait-based analyses to their studies and to make use of process-driven approaches, which are more common in marine studies. We further propose fully comparative trait studies conducted along the habitat gradient spanning freshwater to brackish to marine systems, or along geographic gradients. Such studies will benefit from the combined strength of both fields. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 679 KW - algae KW - functional traits KW - ocean KW - lake KW - biogeochemistry KW - community assembly Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425814 SN - 1866-8372 IS - 679 ER - TY - JOUR A1 - Weithoff, Guntram A1 - Beisner, Beatrix E. T1 - Measures and Approaches in Trait-Based Phytoplankton Community Ecology BT - From Freshwater to Marine Ecosystems JF - Frontiers in Marine Science N2 - Trait-based approaches to investigate (short- and long-term) phytoplankton dynamics and community assembly have become increasingly popular in freshwater and marine science. Although the nature of the pelagic habitat and the main phytoplankton taxa and ecology are relatively similar in both marine and freshwater systems, the lines of research have evolved, at least in part, separately. We compare and contrast the approaches adopted in marine and freshwater ecosystems with respect to phytoplankton functional traits. We note differences in study goals relating to functional trait use that assess community assembly and those that relate to ecosystem processes and biogeochemical cycling that affect the type of characteristics assigned as traits to phytoplankton taxa. Specific phytoplankton traits relevant for ecological function are examined in relation to herbivory, amplitude of environmental change and spatial and temporal scales of study. Major differences are identified, including the shorter time scale for regular environmental change in freshwater ecosystems compared to that in the open oceans as well as the type of sampling done by researchers based on site-accessibility. Overall, we encourage researchers to better motivate why they apply trait-based analyses to their studies and to make use of process-driven approaches, which are more common in marine studies. We further propose fully comparative trait studies conducted along the habitat gradient spanning freshwater to brackish to marine systems, or along geographic gradients. Such studies will benefit from the combined strength of both fields. KW - algae KW - functional traits KW - ocean KW - lake KW - biogeochemistry KW - community assembly Y1 - 2019 U6 - https://doi.org/10.3389/fmars.2019.00040 SN - 2296-7745 VL - 6 PB - Frontiers Media CY - Lausanne ER - TY - THES A1 - Grishina, Yulia T1 - Assessing the applicability of annotation projection methods for coreference relations T1 - Analyse der Qualität von Annotationsprojektionsmethoden für Koreferenzrelationen N2 - The main goal of this thesis is to explore the feasibility of using cross-lingual annotation projection as a method of alleviating the task of manual coreference annotation. To reach our goal, we build a first trilingual parallel coreference corpus that encompasses multiple genres. For the annotation of the corpus, we develop common coreference annotation guidelines that are applicable to three languages (English, German, Russian) and include a novel domain-independent typology of bridging relations as well as state-of-the-art near-identity categories. Thereafter, we design and perform several annotation projection experiments. In the first experiment, we implement a direct projection method with only one source language. Our results indicate that, already in a knowledge-lean scenario, our projection approach is superior to the most closely related work of Postolache et al. (2006). Since the quality of the resulting annotations is to a high degree dependent on the word alignment, we demonstrate how using limited syntactic information helps to further improve mention extraction on the target side. As a next step, in our second experiment, we show how exploiting two source languages helps to improve the quality of target annotations for both language pairs by concatenating annotations projected from two source languages. Finally, we assess the projection quality in a fully automatic scenario (using automatically produced source annotations), and propose a pilot experiment on manual projection of bridging pairs. For each of the experiments, we carry out an in-depth error analysis, and we conclude that noisy word alignments, translation divergences and morphological and syntactic differences between languages are responsible for projection errors. We systematically compare and evaluate our projection methods, and we investigate the errors both qualitatively and quantitatively in order to identify problematic cases. Finally, we discuss the applicability of our method to coreference annotations and propose several avenues of future research. N2 - Ziel dieser Dissertation ist, die Durchführbarkeit von crosslingualer Annotationsprojektion als Methode zur Erleichterung der manuellen Koreferenzannotation zu erproben. Um dieses Ziel zu erreichen, wird das erste dreisprachige parallele Koreferenzkorpus gebaut, das mehrere Textsorten umfasst. Für die Korpusannotation werden gemeinsame Annotationsrichtlinien entwickelt, die auf drei Sprachen anwendbar sind (Englisch, Deutsch, Russisch) und eine neue domänenunabhängige Typologie von indirekten Wiederaufnahmen und sogenannten Near-Identity-Kategorien enthalten. Danach werden mehrere Projektionsexperimente entworfen und durchgeführt. Im ersten Experiment wird eine direkte Projektionsmethode mit nur einer Ausgangs\-sprache implementiert. Die Ergebnisse zeigen, dass bereits in einem wissensarmen Szenario der vorgeschlagene Projektionsansatz die Resultate der verwandten Arbeit von Postolache et al. (2006) übertrifft. Da die Qualität der resultierenden Annotationen in hohem Maße von der Wortalignierung abhängig ist, zeigen wir, wie die Verwendung begrenzter syntaktischer Informationen weiterhilft, die Extraktion von referierenden Ausdrücken auf der Zielseite zu verbessern. Im nächsten Schritt, dem zweiten Experiment, demonstrieren wir, wie die Nutzung von zwei Ausgangssprachen zur weiteren Verbesserung der Qualität der Zielannotationen für beide Sprachpaare beiträgt, indem die Annotationen aus zwei Quellsprachen kombiniert werden. Schließlich wird die Projektionsqualität noch in einem vollautomatischen Szenario ausgewertet (mit automatisch erstellten Quellannotationen), und ein Pilotversuch zur manuellen Projektion von Paaren indirekter Wiederaufnahmen vorgestellt. Für jedes Experiment wird eine detaillierte Fehleranalyse durchgeführt. Daraus schließen wir, dass fehlerhafte Wortalignierungen, Übersetzungsdivergenzen und morphologische sowie syntaktische Unterschiede zwischen den Sprachen für die Projektionsfehler verantwortlich sind. Hierzu werden die Projektionsmethoden systematisch verglichen und ausgewertet, und die Fehler sowohl qualitativ als auch quantitativ untersucht, um problematische Fälle zu identifizieren. Zum Schluss wird die Anwendbarkeit unserer Methode für Koreferenzannotationen diskutiert, und es werden Ansatzpunkte für weitere Forschung vorgeschlagen. KW - annotation KW - annotation projection KW - bridging KW - near-identity KW - coreference resolution KW - multilingual coreference KW - coreference corpus KW - Annotation KW - Annotationsprojektion KW - Koreferenz KW - indirekte Wiederaufnahmen KW - Near-identity KW - Koreferenzauflösung KW - multilinguale Koreferenz KW - Koreferenzkorpus Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425378 ER - TY - GEN A1 - Schneider, Simon A1 - Heinecke, Liv T1 - The need to transform Science Communication from being multi-cultural via cross-cultural to intercultural T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - When dealing with issues that are of high so-cietal relevance, Earth sciences still face a lack of accep-tance, which is partly rooted in insufficient communicationstrategies on the individual and local community level. Toincrease the efficiency of communication routines, sciencehas to transform its outreach concepts to become more awareof individual needs and demands. The “encoding/decoding”concept as well as critical intercultural communication stud-ies can offer pivotal approaches for this transformation. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 677 Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425768 SN - 1866-8372 IS - 677 ER - TY - JOUR A1 - Schneider, Simon A1 - Heinecke, Liv T1 - The need to transform Science Communication from being multi-cultural via cross-cultural to intercultural JF - Advances in Geosciences N2 - When dealing with issues that are of high societal relevance, Earth sciences still face a lack of acceptance, which is partly rooted in insufficient communication strategies on the individual and local community level. To increase the efficiency of communication routines, science has to transform its outreach concepts to become more aware of individual needs and demands. The “encoding/decoding” concept as well as critical intercultural communication studies can offer pivotal approaches for this transformation. Y1 - 2019 U6 - https://doi.org/10.5194/adgeo-46-11-2019 SN - 1680-7359 IS - 46 SP - 11 EP - 19 PB - Copernicus Publications CY - Göttingen ER - TY - THES A1 - Ferrari, Camilla T1 - Comparative transcriptomic studies to predict gene function and investigate the evolution of diurnal regulation Y1 - 2019 ER - TY - GEN A1 - Biskaborn, Boris A1 - Smith, Sharon L. A1 - Noetzli, Jeannette A1 - Matthes, Heidrun A1 - Vieira, Gonçalo A1 - Streletskiy, Dmitry A. A1 - Schoeneich, Philippe A1 - Romanovsky, Vladimir E. A1 - Lewkowicz, Antoni G. A1 - Abramov, Andrey A1 - Allard, Michel A1 - Boike, Julia A1 - Cable, William L. A1 - Christiansen, Hanne H. A1 - Delaloye, Reynald A1 - Diekmann, Bernhard A1 - Drozdov, Dmitry A1 - Etzelmüller, Bernd A1 - Große, Guido A1 - Guglielmin, Mauro A1 - Ingeman-Nielsen, Thomas A1 - Isaksen, Ketil A1 - Ishikawa, Mamoru A1 - Johansson, Margareta A1 - Joo, Anseok A1 - Kaverin, Dmitry A1 - Kholodov, Alexander A1 - Konstantinov, Pavel A1 - Kröger, Tim A1 - Lambiel, Christophe A1 - Lanckman, Jean-Pierre A1 - Luo, Dongliang A1 - Malkova, Galina A1 - Meiklejohn, Ian A1 - Moskalenko, Natalia A1 - Oliva, Marc A1 - Phillips, Marcia A1 - Ramos, Miguel A1 - Sannel, A. Britta K. A1 - Sergeev, Dmitrii A1 - Seybold, Cathy A1 - Skryabin, Pavel A1 - Vasiliev, Alexander A1 - Wu, Qingbai A1 - Yoshikawa, Kenji A1 - Zheleznyak, Mikhail A1 - Lantuit, Hugues T1 - Permafrost is warming at a global scale T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Permafrost warming has the potential to amplify global climate change, because when frozen sediments thaw it unlocks soil organic carbon. Yet to date, no globally consistent assessment of permafrost temperature change has been compiled. Here we use a global data set of permafrost temperature time series from the Global Terrestrial Network for Permafrost to evaluate temperature change across permafrost regions for the period since the International Polar Year (2007–2009). During the reference decade between 2007 and 2016, ground temperature near the depth of zero annual amplitude in the continuous permafrost zone increased by 0.39 ± 0.15 °C. Over the same period, discontinuous permafrost warmed by 0.20 ± 0.10 °C. Permafrost in mountains warmed by 0.19 ± 0.05 °C and in Antarctica by 0.37 ± 0.10 °C. Globally, permafrost temperature increased by 0.29 ± 0.12 °C. The observed trend follows the Arctic amplification of air temperature increase in the Northern Hemisphere. In the discontinuous zone, however, ground warming occurred due to increased snow thickness while air temperature remained statistically unchanged. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 669 KW - seasonal snow cover KW - thermal state KW - climate-change KW - activ-layer KW - Antarctic Peninsula KW - stability Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425341 SN - 1866-8372 IS - 669 ER - TY - CHAP A1 - Turner, Bryan S. T1 - Introduction BT - demography, demogracy and right-wing populism T2 - Populism and the crisis of democracy. Volume 3. Migration, gender and religion Y1 - 2019 SN - 978-1-138-09138-2 SP - 1 EP - 8 PB - Routledge CY - London ER - TY - CHAP A1 - Fitzi, Gregor T1 - Introduction BT - political populism as a symptom of the great transformation of democracy T2 - Populism and the crisis of democracy. Volume 2. Politics, social movements and extremism Y1 - 2019 SN - 978-1-138-09137-5 SP - 1 EP - 8 PB - Routledge CY - London ER - TY - BOOK ED - Fitzi, Gregor ED - Mackert, Jürgen ED - Turner, Bryan S. T1 - Politics, Social Movements and Extremism T3 - Populism and the crisis of democracy N2 - The contributions to this volume Politics, Social Movements and Extremism take serious the fact that populism is a symptom of the crisis of representation that is affecting parliamentary democracy. Right-wing populism skyrocketed to electoral success and is now part of the government in several European countries, but it also shaped the Brexit campaign and the US presidential election. In Southern Europe, left-wing populism transformed the classical two parties systems into ungovernable three fractions parliaments, whereas in Latin America it still presents an instable alternative to liberal democracy. The varying consequences of populist mobilisation so far consist in the maceration of the established borders of political culture, the distortion of legislation concerning migrants and migration, and the emergence of hybrid regimes bordering on and sometimes leaning towards dictatorship. Yet, in order to understand populism, innovative research approaches are required that need to be capable of overcoming stereotypes and conceptual dichotomies which are deeply rooted in the political debate. The chapters of this volume offer such new theoretical strategies for inquiring into the multi-faceted populist phenomenon. The chapters analyse its language, concepts and its relationship to social media in an innovative way, draw the con -tours of left- and right-wing populism and reconstruct its shifting delimitation to political extremism. Furthermore, they value the most significant aftermath of populist mobilisation on the institutional frame of parliamentary democracy from the limitation of the freedom of press, to the dismantling of the separation of powers, to the erosion of citizenship rights. This volume will be an invaluable reference for students and scholars in the field of political theory, political sociology and European Studies. Y1 - 2019 SN - 978-1-31510-806-3 SN - 978-1-138-09137-5 U6 - https://doi.org/10.4324/9781315108063 VL - 2 PB - Routledge CY - London ER - TY - GEN A1 - Sperber, Hannah Sabeth A1 - Welke, Robert-William A1 - Petazzi, Roberto Arturo A1 - Bergmann, Ronny A1 - Schade, Matthias A1 - Shai, Yechiel A1 - Chiantia, Salvatore A1 - Herrmann, Andreas A1 - Schwarzer, Roland T1 - Self-association and subcellular localization of Puumala hantavirus envelope proteins T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Hantavirus assembly and budding are governed by the surface glycoproteins Gn and Gc. In this study, we investigated the glycoproteins of Puumala, the most abundant Hantavirus species in Europe, using fluorescently labeled wild-type constructs and cytoplasmic tail (CT) mutants. We analyzed their intracellular distribution, co-localization and oligomerization, applying comprehensive live, single-cell fluorescence techniques, including confocal microscopy, imaging flow cytometry, anisotropy imaging and Number&Brightness analysis. We demonstrate that Gc is significantly enriched in the Golgi apparatus in absence of other viral components, while Gn is mainly restricted to the endoplasmic reticulum (ER). Importantly, upon co-expression both glycoproteins were found in the Golgi apparatus. Furthermore, we show that an intact CT of Gc is necessary for efficient Golgi localization, while the CT of Gn influences protein stability. Finally, we found that Gn assembles into higher-order homo-oligomers, mainly dimers and tetramers, in the ER while Gc was present as mixture of monomers and dimers within the Golgi apparatus. Our findings suggest that PUUV Gc is the driving factor of the targeting of Gc and Gn to the Golgi region, while Gn possesses a significantly stronger self-association potential. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 648 KW - Sin-Nombre-Virus KW - nucleocapsid protein KW - cytoplasmic tails KW - electron cryotomography KW - autophagic clearance KW - glycoprotein KW - Gn KW - G1 KW - brightness KW - fever Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425040 SN - 1866-8372 IS - 648 ER - TY - GEN A1 - Marc, Odin A1 - Behling, Robert A1 - Andermann, Christoff A1 - Turowski, Jens M. A1 - Illien, Luc A1 - Roessner, Sigrid A1 - Hovius, Niels T1 - Long-term erosion of the Nepal Himalayas by bedrock landsliding BT - the role of monsoons, earthquakes and giant landslides T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - In active mountain belts with steep terrain, bedrock landsliding is a major erosional agent. In the Himalayas, landsliding is driven by annual hydro-meteorological forcing due to the summer monsoon and by rarer, exceptional events, such as earthquakes. Independent methods yield erosion rate estimates that appear to increase with sampling time, suggesting that rare, high-magnitude erosion events dominate the erosional budget. Nevertheless, until now, neither the contribution of monsoon and earthquakes to landslide erosion nor the proportion of erosion due to rare, giant landslides have been quantified in the Himalayas. We address these challenges by combining and analysing earthquake- and monsoon-induced landslide inventories across different timescales. With time series of 5 m satellite images over four main valleys in central Nepal, we comprehensively mapped landslides caused by the monsoon from 2010 to 2018. We found no clear correlation between monsoon properties and landsliding and a similar mean landsliding rate for all valleys, except in 2015, where the valleys affected by the earthquake featured ∼ 5–8 times more landsliding than the pre-earthquake mean rate. The longterm size–frequency distribution of monsoon-induced landsliding (MIL) was derived from these inventories and from an inventory of landslides larger than ∼ 0.1 km 2 that occurred between 1972 and 2014. Using a published landslide inventory for the Gorkha 2015 earthquake, we derive the size–frequency distribution for earthquake-induced landsliding (EQIL). These two distributions are dominated by infrequent, large and giant landslides but under-predict an estimated Holocene frequency of giant landslides (> 1 km 3 ) which we derived from a literature compilation. This discrepancy can be resolved when modelling the effect of a full distribution of earthquakes of variable magnitude and when considering that a shallower earthquake may cause larger landslides. In this case, EQIL and MIL contribute about equally to a total long-term erosion of ∼ 2 ± 0.75 mm yr −1 in agreement with most thermo-chronological data. Independently of the specific total and relative erosion rates, the heavy-tailed size–frequency distribution from MIL and EQIL and the very large maximal landslide size in the Himalayas indicate that mean landslide erosion rates increase with sampling time, as has been observed for independent erosion estimates. Further, we find that the sampling timescale required to adequately capture the frequency of the largest landslides, which is necessary for deriving long-term mean erosion rates, is often much longer than the averaging time of cosmogenic 10 Be methods. This observation presents a strong caveat when interpreting spatial or temporal variability in erosion rates from this method. Thus, in areas where a very large, rare landslide contributes heavily to long-term erosion (as the Himalayas), we recommend 10 Be sample in catchments with source areas > 10 000 km 2 to reduce the method mean bias to below ∼ 20 % of the long-term erosion. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 646 KW - rainfall thresholds KW - global database KW - sediment flux KW - mountain belt KW - rates KW - river KW - size KW - exhumation KW - precipitation KW - inventories Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425022 SN - 1866-8372 IS - 646 ER - TY - GEN A1 - Sixtus, Elena A1 - Lonnemann, Jan A1 - Fischer, Martin H. A1 - Werner, Karsten T1 - Mental Number Representations in 2D Space T2 - Postprints der Universität Potsdam Humanwissenschaftliche Reihe N2 - There is evidence both for mental number representations along a horizontal mental number line with larger numbers to the right of smaller numbers (for Western cultures) and a physically grounded, vertical representation where “more is up.” Few studies have compared effects in the horizontal and vertical dimension and none so far have combined both dimensions within a single paradigm where numerical magnitude was task-irrelevant and none of the dimensions was primed by a response dimension. We now investigated number representations over both dimensions, building on findings that mental representations of numbers and space co-activate each other. In a Go/No-go experiment, participants were auditorily primed with a relatively small or large number and then visually presented with quasi-randomly distributed distractor symbols and one Arabic target number (in Go trials only). Participants pressed a central button whenever they detected the target number and elsewise refrained from responding. Responses were not more efficient when small numbers were presented to the left and large numbers to the right. However, results indicated that large numbers were associated with upper space more strongly than small numbers. This suggests that in two-dimensional space when no response dimension is given, numbers are conceptually associated with vertical, but not horizontal space. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 538 KW - spatial-numerical associations KW - SNARC KW - vertical space KW - horizontal space KW - Go/No-go task Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-424960 SN - 1866-8364 IS - 538 ER - TY - JOUR A1 - Sixtus, Elena A1 - Lonnemann, Jan A1 - Fischer, Martin H. A1 - Werner, Karsten T1 - Mental Number Representations in 2D Space JF - Frontiers in Psychology N2 - There is evidence both for mental number representations along a horizontal mental number line with larger numbers to the right of smaller numbers (for Western cultures) and a physically grounded, vertical representation where “more is up.” Few studies have compared effects in the horizontal and vertical dimension and none so far have combined both dimensions within a single paradigm where numerical magnitude was task-irrelevant and none of the dimensions was primed by a response dimension. We now investigated number representations over both dimensions, building on findings that mental representations of numbers and space co-activate each other. In a Go/No-go experiment, participants were auditorily primed with a relatively small or large number and then visually presented with quasi-randomly distributed distractor symbols and one Arabic target number (in Go trials only). Participants pressed a central button whenever they detected the target number and elsewise refrained from responding. Responses were not more efficient when small numbers were presented to the left and large numbers to the right. However, results indicated that large numbers were associated with upper space more strongly than small numbers. This suggests that in two-dimensional space when no response dimension is given, numbers are conceptually associated with vertical, but not horizontal space. KW - spatial-numerical associations KW - SNARC KW - vertical space KW - horizontal space KW - Go/No-go task Y1 - 2019 U6 - https://doi.org/10.3389/fpsyg.2019.00172 SN - 1664-1078 VL - 10 PB - Frontiers Research Foundation CY - Lausanne ER - TY - GEN A1 - Czapka, Sophia A1 - Klassert, Annegret A1 - Festman, Julia T1 - Executive Functions and Language BT - Their Differential Influence on Mono- vs. Multilingual Spelling in Primary School T2 - Postprints der Universität Potsdam Humanwissenschaftliche Reihe N2 - We aimed at unveiling the role of executive functions (EFs) and language-related skills in spelling for mono- versus multilingual primary school children. We focused on EF and language-related skills, in particular lexicon size and phonological awareness (PA), because these factors were found to predict spelling in studies predominantly conducted with monolinguals, and because multilingualism can modulate these factors. There is evidence for (a) a bilingual advantage in EF due to constant high cognitive demands through language control, (b) a smaller mental lexicon in German and (c) possibly better PA. Multilinguals in Germany show on average poorer German language proficiency, what can influence performance on language-based tasks negatively. Thus, we included two spelling tasks to tease apart spelling based on lexical knowledge (i.e., word spelling) from spelling based on non-lexical strategies (i.e., non-word spelling). Our sample consisted of heterogeneous third graders from Germany: 69 monolinguals (age: M = 108 months) and 57 multilinguals (age: M = 111 months). On less language-dependent tasks (e.g., non-word spelling, PA, intelligence, short-term memory (STM) and three EF tasks testing switching, inhibition, and working memory) performance of both groups did not differ significantly. However, multilinguals performed significantly more poorly on tasks measuring German lexicon size and word spelling than monolinguals. Regression analyses revealed that for multilinguals, inhibition was related to spelling, whereas switching was the only EF component to influence word spelling in monolinguals and non-word spelling performance in both groups. By adding lexicon size and other language-related factors to the regression models, the influence of switching was reduced to insignificant effects, but inhibition remained significant for multilinguals. Language-related skills best predicted spelling and both language groups shared those variables: PA for word spelling, and STM for non-word spelling. Additionally, multilinguals’ word spelling performance was also predicted by their German lexicon size, and non-word spelling performance by PA. This study offers an in-depth look at spelling acquisition at a certain point of literacy development. Mono- and multilinguals have the predominant factors for spelling in common, but probably due to superior language knowledge, monolinguals were already able to make use of EF during spelling. For multilinguals, German lexicon size was more important for spelling than EF. For multilinguals’ spelling these functions might come into play only at a later stage. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 537 KW - bilingualism KW - spelling KW - literacy acquisition KW - executive functions KW - lexicon size KW - primary school Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-424935 SN - 1866-8364 IS - 537 ER - TY - JOUR A1 - Czapka, Sophia A1 - Klassert, Annegret A1 - Festman, Julia T1 - Executive Functions and Language BT - Their Differential Influence on Mono- vs. Multilingual Spelling in Primary School JF - Frontiers in Psychology N2 - We aimed at unveiling the role of executive functions (EFs) and language-related skills in spelling for mono- versus multilingual primary school children. We focused on EF and language-related skills, in particular lexicon size and phonological awareness (PA), because these factors were found to predict spelling in studies predominantly conducted with monolinguals, and because multilingualism can modulate these factors. There is evidence for (a) a bilingual advantage in EF due to constant high cognitive demands through language control, (b) a smaller mental lexicon in German and (c) possibly better PA. Multilinguals in Germany show on average poorer German language proficiency, what can influence performance on language-based tasks negatively. Thus, we included two spelling tasks to tease apart spelling based on lexical knowledge (i.e., word spelling) from spelling based on non-lexical strategies (i.e., non-word spelling). Our sample consisted of heterogeneous third graders from Germany: 69 monolinguals (age: M = 108 months) and 57 multilinguals (age: M = 111 months). On less language-dependent tasks (e.g., non-word spelling, PA, intelligence, short-term memory (STM) and three EF tasks testing switching, inhibition, and working memory) performance of both groups did not differ significantly. However, multilinguals performed significantly more poorly on tasks measuring German lexicon size and word spelling than monolinguals. Regression analyses revealed that for multilinguals, inhibition was related to spelling, whereas switching was the only EF component to influence word spelling in monolinguals and non-word spelling performance in both groups. By adding lexicon size and other language-related factors to the regression models, the influence of switching was reduced to insignificant effects, but inhibition remained significant for multilinguals. Language-related skills best predicted spelling and both language groups shared those variables: PA for word spelling, and STM for non-word spelling. Additionally, multilinguals’ word spelling performance was also predicted by their German lexicon size, and non-word spelling performance by PA. This study offers an in-depth look at spelling acquisition at a certain point of literacy development. Mono- and multilinguals have the predominant factors for spelling in common, but probably due to superior language knowledge, monolinguals were already able to make use of EF during spelling. For multilinguals, German lexicon size was more important for spelling than EF. For multilinguals’ spelling these functions might come into play only at a later stage. KW - bilingualism KW - spelling KW - literacy acquisition KW - executive functions KW - lexicon size KW - primary school Y1 - 2019 U6 - https://doi.org/10.3389/fpsyg.2019.00097 SN - 1664-1078 VL - 10 PB - Frontiers Research Foundation CY - Lausanne ER - TY - GEN A1 - Zinke, Fridolin A1 - Warnke, Torsten A1 - Gäbler, Martijn A1 - Granacher, Urs T1 - Effects of Isokinetic Training on Trunk Muscle Fitness and Body Composition in World-Class Canoe Sprinters T2 - Postprints der Universität Potsdam Humanwissenschaftliche Reihe N2 - In canoe sprint, the trunk muscles play an important role in stabilizing the body in an unstable environment (boat) and in generating forces that are transmitted through the shoulders and arms to the paddle for propulsion of the boat. Isokinetic training is well suited for sports in which propulsion is generated through water resistance due to similarities in the resistive mode. Thus, the purpose of this study was to determine the effects of isokinetic training in addition to regular sport-specific training on trunk muscular fitness and body composition in world-class canoeists and to evaluate associations between trunk muscular fitness and canoe-specific performance. Nine world-class canoeists (age: 25.6 ± 3.3 years; three females; four world champions; three Olympic gold medalists) participated in an 8-week progressive isokinetic training with a 6-week block “muscle hypertrophy” and a 2-week block “muscle power.” Pre- and post-tests included the assessment of peak isokinetic torque at different velocities in concentric (30 and 140∘s-1) and eccentric (30 and 90∘s-1) mode, trunk muscle endurance, and body composition (e.g., body fat, segmental lean mass). Additionally, peak paddle force was assessed in the flume at a water current of 3.4 m/s. Significant pre-to-post increases were found for peak torque of the trunk rotators at 30∘s-1 (p = 0.047; d = 0.4) and 140∘s-1 (p = 0.014; d = 0.7) in concentric mode. No significant pre-to-post changes were detected for eccentric trunk rotator torque, trunk muscle endurance, and body composition (p > 0.148). Significant medium-to-large correlations were observed between concentric trunk rotator torque but not trunk muscle endurance and peak paddle force, irrespective of the isokinetic movement velocity (all r ≥ 0.886; p ≤ 0.008). Isokinetic trunk rotator training is effective in improving concentric trunk rotator strength in world-class canoe sprinters. It is recommended to progressively increase angular velocity from 30∘s-1 to 140∘s-1 over the course of the training period. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 536 KW - peak torque KW - canoe racing KW - core strength KW - sport-specific performance KW - elite athletes Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-424898 SN - 1866-8364 IS - 536 ER - TY - JOUR A1 - Zinke, Fridolin A1 - Warnke, Torsten A1 - Gäbler, Martijn A1 - Granacher, Urs T1 - Effects of Isokinetic Training on Trunk Muscle Fitness and Body Composition in World-Class Canoe Sprinters JF - Frontiers in Physiology N2 - In canoe sprint, the trunk muscles play an important role in stabilizing the body in an unstable environment (boat) and in generating forces that are transmitted through the shoulders and arms to the paddle for propulsion of the boat. Isokinetic training is well suited for sports in which propulsion is generated through water resistance due to similarities in the resistive mode. Thus, the purpose of this study was to determine the effects of isokinetic training in addition to regular sport-specific training on trunk muscular fitness and body composition in world-class canoeists and to evaluate associations between trunk muscular fitness and canoe-specific performance. Nine world-class canoeists (age: 25.6 ± 3.3 years; three females; four world champions; three Olympic gold medalists) participated in an 8-week progressive isokinetic training with a 6-week block “muscle hypertrophy” and a 2-week block “muscle power.” Pre- and post-tests included the assessment of peak isokinetic torque at different velocities in concentric (30 and 140∘s-1) and eccentric (30 and 90∘s-1) mode, trunk muscle endurance, and body composition (e.g., body fat, segmental lean mass). Additionally, peak paddle force was assessed in the flume at a water current of 3.4 m/s. Significant pre-to-post increases were found for peak torque of the trunk rotators at 30∘s-1 (p = 0.047; d = 0.4) and 140∘s-1 (p = 0.014; d = 0.7) in concentric mode. No significant pre-to-post changes were detected for eccentric trunk rotator torque, trunk muscle endurance, and body composition (p > 0.148). Significant medium-to-large correlations were observed between concentric trunk rotator torque but not trunk muscle endurance and peak paddle force, irrespective of the isokinetic movement velocity (all r ≥ 0.886; p ≤ 0.008). Isokinetic trunk rotator training is effective in improving concentric trunk rotator strength in world-class canoe sprinters. It is recommended to progressively increase angular velocity from 30∘s-1 to 140∘s-1 over the course of the training period. KW - peak torque KW - canoe racing KW - core strength KW - sport-specific performance KW - elite athletes Y1 - 2019 U6 - https://doi.org/10.3389/fphys.2019.00021 SN - 1664-042X VL - 10 PB - Frontiers Research Foundation CY - Lausanne ER - TY - GEN A1 - Sánchez, Alba A1 - Thomas, Christine A1 - Deeken, Friederike A1 - Wagner, Sören A1 - Klöppel, Stefan A1 - Kentischer, Felix A1 - von Arnim, Chrstine A. F. A1 - Denkinger, Michael A1 - Conzelmann, Lars O. A1 - Biermann-Stallwitz, Janine A1 - Joos, Stefanie A1 - Sturm, Heidrun A1 - Metz, Brigitte A1 - Auer, Ramona A1 - Skrobik, Yoanna A1 - Eschweiler, Gerhard W. A1 - Rapp, Michael A. T1 - Patient safety, cost-effectiveness, and quality of life BT - reduction of delirium risk and postoperative cognitive dysfunction after elective procedures in older adults—study protocol for a stepped-wedge cluster randomized trial (PAWEL Study) T2 - Postprints der Universität Potsdam Humanwissenschaftliche Reihe N2 - Background Postoperative delirium is a common disorder in older adults that is associated with higher morbidity and mortality, prolonged cognitive impairment, development of dementia, higher institutionalization rates, and rising healthcare costs. The probability of delirium after surgery increases with patients’ age, with pre-existing cognitive impairment, and with comorbidities, and its diagnosis and treatment is dependent on the knowledge of diagnostic criteria, risk factors, and treatment options of the medical staff. In this study, we will investigate whether a cross-sectoral and multimodal intervention for preventing delirium can reduce the prevalence of delirium and postoperative cognitive decline (POCD) in patients older than 70 years undergoing elective surgery. Additionally, we will analyze whether the intervention is cost-effective. Methods The study will be conducted at five medical centers (with two or three surgical departments each) in the southwest of Germany. The study employs a stepped-wedge design with cluster randomization of the medical centers. Measurements are performed at six consecutive points: preadmission, preoperative, and postoperative with daily delirium screening up to day 7 and POCD evaluations at 2, 6, and 12 months after surgery. Recruitment goals are to enroll 1500 patients older than 70 years undergoing elective operative procedures (cardiac, thoracic, vascular, proximal big joints and spine, genitourinary, gastrointestinal, and general elective surgery procedures. Discussion Results of the trial should form the basis of future standards for preventing delirium and POCD in surgical wards. Key aims are the improvement of patient safety and quality of life, as well as the reduction of the long-term risk of conversion to dementia. Furthermore, from an economic perspective, we expect benefits and decreased costs for hospitals, patients, and healthcare insurances. Trial registration German Clinical Trials Register, DRKS00013311. Registered on 10 November 2017. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 535 KW - Cross-sectoral care KW - Delirium prevention KW - Postoperative cognitive dysfunction KW - Dementia KW - Older patients KW - Elective surgery KW - Quality of life KW - Cost-effectiveness Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-424883 SN - 1866-8364 IS - 535 ER - TY - JOUR A1 - Sánchez, Alba A1 - Thomas, Christine A1 - Deeken, Friederike A1 - Wagner, Sören A1 - Klöppel, Stefan A1 - Kentischer, Felix A1 - von Arnim, Chrstine A. F. A1 - Denkinger, Michael A1 - Conzelmann, Lars O. A1 - Biermann-Stallwitz, Janine A1 - Joos, Stefanie A1 - Sturm, Heidrun A1 - Metz, Brigitte A1 - Auer, Ramona A1 - Skrobik, Yoanna A1 - Eschweiler, Gerhard W. A1 - Rapp, Michael A. T1 - Patient safety, cost-effectiveness, and quality of life BT - reduction of delirium risk and postoperative cognitive dysfunction after elective procedures in older adults—study protocol for a stepped-wedge cluster randomized trial (PAWEL Study) JF - Trials N2 - Background Postoperative delirium is a common disorder in older adults that is associated with higher morbidity and mortality, prolonged cognitive impairment, development of dementia, higher institutionalization rates, and rising healthcare costs. The probability of delirium after surgery increases with patients’ age, with pre-existing cognitive impairment, and with comorbidities, and its diagnosis and treatment is dependent on the knowledge of diagnostic criteria, risk factors, and treatment options of the medical staff. In this study, we will investigate whether a cross-sectoral and multimodal intervention for preventing delirium can reduce the prevalence of delirium and postoperative cognitive decline (POCD) in patients older than 70 years undergoing elective surgery. Additionally, we will analyze whether the intervention is cost-effective. Methods The study will be conducted at five medical centers (with two or three surgical departments each) in the southwest of Germany. The study employs a stepped-wedge design with cluster randomization of the medical centers. Measurements are performed at six consecutive points: preadmission, preoperative, and postoperative with daily delirium screening up to day 7 and POCD evaluations at 2, 6, and 12 months after surgery. Recruitment goals are to enroll 1500 patients older than 70 years undergoing elective operative procedures (cardiac, thoracic, vascular, proximal big joints and spine, genitourinary, gastrointestinal, and general elective surgery procedures. Discussion Results of the trial should form the basis of future standards for preventing delirium and POCD in surgical wards. Key aims are the improvement of patient safety and quality of life, as well as the reduction of the long-term risk of conversion to dementia. Furthermore, from an economic perspective, we expect benefits and decreased costs for hospitals, patients, and healthcare insurances. Trial registration German Clinical Trials Register, DRKS00013311. Registered on 10 November 2017. KW - Cross-sectoral care KW - Delirium prevention KW - Postoperative cognitive dysfunction KW - Dementia KW - Older patients KW - Elective surgery KW - Quality of life KW - Cost-effectiveness Y1 - 2019 U6 - https://doi.org/10.1186/s13063-018-3148-8 SN - 1468-6694 SN - 1745-6215 SN - 1468-6708 VL - 20 IS - 71 PB - BioMed Central CY - London ER - TY - GEN A1 - Lozada Gobilard, Sissi Donna A1 - Stang, Susanne A1 - Pirhofer-Walzl, Karin A1 - Kalettka, Thomas A1 - Heinken, Thilo A1 - Schröder, Boris A1 - Eccard, Jana A1 - Jasmin Radha, Jasmin T1 - Environmental filtering predicts plant‐community trait distribution and diversity BT - Kettle holes as models of meta‐community systems T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Meta‐communities of habitat islands may be essential to maintain biodiversity in anthropogenic landscapes allowing rescue effects in local habitat patches. To understand the species‐assembly mechanisms and dynamics of such ecosystems, it is important to test how local plant‐community diversity and composition is affected by spatial isolation and hence by dispersal limitation and local environmental conditions acting as filters for local species sorting. We used a system of 46 small wetlands (kettle holes)—natural small‐scale freshwater habitats rarely considered in nature conservation policies—embedded in an intensively managed agricultural matrix in northern Germany. We compared two types of kettle holes with distinct topographies (flatsloped, ephemeral, frequently plowed kettle holes vs. steep‐sloped, more permanent ones) and determined 254 vascular plant species within these ecosystems, as well as plant functional traits and nearest neighbor distances to other kettle holes. Differences in alpha and beta diversity between steep permanent compared with ephemeral flat kettle holes were mainly explained by species sorting and niche processes and mass effect processes in ephemeral flat kettle holes. The plant‐community composition as well as the community trait distribution in terms of life span, breeding system, dispersal ability, and longevity of seed banks significantly differed between the two habitat types. Flat ephemeral kettle holes held a higher percentage of non‐perennial plants with a more persistent seed bank, less obligate outbreeders and more species with seed dispersal abilities via animal vectors compared with steep‐sloped, more permanent kettle holes that had a higher percentage of wind‐dispersed species. In the flat kettle holes, plant‐species richness was negatively correlated with the degree of isolation, whereas no such pattern was found for the permanent kettle holes. Synthesis: Environment acts as filter shaping plant diversity (alpha and beta) and plant‐community trait distribution between steep permanent compared with ephemeral flat kettle holes supporting species sorting and niche mechanisms as expected, but we identified a mass effect in ephemeral kettle holes only. Flat ephemeral kettle holes can be regarded as meta‐ecosystems that strongly depend on seed dispersal and recruitment from a seed bank, whereas neighboring permanent kettle holes have a more stable local species diversity. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 629 KW - biodiversity KW - dispersal KW - disturbance KW - landscape diversity KW - life‐history traits KW - plant diversity KW - seed bank KW - species assembly KW - wetland vegetation Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-424843 SN - 1866-8372 IS - 629 ER - TY - JOUR A1 - Lozada Gobilard, Sissi Donna A1 - Stang, Susanne A1 - Pirhofer-Walzl, Karin A1 - Kalettka, Thomas A1 - Heinken, Thilo A1 - Schröder, Boris A1 - Eccard, Jana A1 - Jasmin Radha, Jasmin T1 - Environmental filtering predicts plant‐community trait distribution and diversity BT - Kettle holes as models of meta‐community systems JF - Ecology and Evolution N2 - Meta‐communities of habitat islands may be essential to maintain biodiversity in anthropogenic landscapes allowing rescue effects in local habitat patches. To understand the species‐assembly mechanisms and dynamics of such ecosystems, it is important to test how local plant‐community diversity and composition is affected by spatial isolation and hence by dispersal limitation and local environmental conditions acting as filters for local species sorting. We used a system of 46 small wetlands (kettle holes)—natural small‐scale freshwater habitats rarely considered in nature conservation policies—embedded in an intensively managed agricultural matrix in northern Germany. We compared two types of kettle holes with distinct topographies (flatsloped, ephemeral, frequently plowed kettle holes vs. steep‐sloped, more permanent ones) and determined 254 vascular plant species within these ecosystems, as well as plant functional traits and nearest neighbor distances to other kettle holes. Differences in alpha and beta diversity between steep permanent compared with ephemeral flat kettle holes were mainly explained by species sorting and niche processes and mass effect processes in ephemeral flat kettle holes. The plant‐community composition as well as the community trait distribution in terms of life span, breeding system, dispersal ability, and longevity of seed banks significantly differed between the two habitat types. Flat ephemeral kettle holes held a higher percentage of non‐perennial plants with a more persistent seed bank, less obligate outbreeders and more species with seed dispersal abilities via animal vectors compared with steep‐sloped, more permanent kettle holes that had a higher percentage of wind‐dispersed species. In the flat kettle holes, plant‐species richness was negatively correlated with the degree of isolation, whereas no such pattern was found for the permanent kettle holes. Synthesis: Environment acts as filter shaping plant diversity (alpha and beta) and plant‐community trait distribution between steep permanent compared with ephemeral flat kettle holes supporting species sorting and niche mechanisms as expected, but we identified a mass effect in ephemeral kettle holes only. Flat ephemeral kettle holes can be regarded as meta‐ecosystems that strongly depend on seed dispersal and recruitment from a seed bank, whereas neighboring permanent kettle holes have a more stable local species diversity. KW - biodiversity KW - dispersal KW - disturbance KW - landscape diversity KW - life‐history traits KW - plant diversity KW - seed bank KW - species assembly KW - wetland vegetation Y1 - 2019 U6 - https://doi.org/10.1002/ece3.4883 SN - 2045-7758 PB - John Wiley & Sons, Inc. CY - Hoboken ER - TY - GEN A1 - Schneider, Birgit A1 - Walsh, Lynda T1 - The politics of zoom BT - Problems with downscaling climate visualizations T2 - Postprints der Universität Potsdam Philosophische Reihe N2 - Following the mandate in the Paris Agreement for signatories to provide “climate services” to their constituents, “downscaled” climate visualizations are proliferating. But the process of downscaling climate visualizations does not neutralize the political problems with their synoptic global sources—namely, their failure to empower communities to take action and their replication of neoliberal paradigms of globalization. In this study we examine these problems as they apply to interactive climate‐visualization platforms, which allow their users to localize global climate information to support local political action. By scrutinizing the political implications of the “zoom” tool from the perspective of media studies and rhetoric, we add to perspectives of cultural cartography on the issue of scaling from our fields. Namely, we break down the cinematic trope of “zooming” to reveal how it imports the political problems of synopticism to the level of individual communities. As a potential antidote to the politics of zoom, we recommend a downscaling strategy of connectivity, which associates rather than reduces situated views of climate to global ones. T3 - Zweitveröffentlichungen der Universität Potsdam : Philosophische Reihe - 159 KW - climate change KW - climate services KW - climate visualization KW - connectivity KW - downscaling KW - spherical KW - synopticism KW - zoom Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-424819 SN - 1866-8380 IS - 159 ER - TY - JOUR A1 - Schneider, Birgit A1 - Walsh, Lynda T1 - The politics of zoom BT - Problems with downscaling climate visualizations JF - Geo: Geography and Environment N2 - Following the mandate in the Paris Agreement for signatories to provide “climate services” to their constituents, “downscaled” climate visualizations are proliferating. But the process of downscaling climate visualizations does not neutralize the political problems with their synoptic global sources—namely, their failure to empower communities to take action and their replication of neoliberal paradigms of globalization. In this study we examine these problems as they apply to interactive climate‐visualization platforms, which allow their users to localize global climate information to support local political action. By scrutinizing the political implications of the “zoom” tool from the perspective of media studies and rhetoric, we add to perspectives of cultural cartography on the issue of scaling from our fields. Namely, we break down the cinematic trope of “zooming” to reveal how it imports the political problems of synopticism to the level of individual communities. As a potential antidote to the politics of zoom, we recommend a downscaling strategy of connectivity, which associates rather than reduces situated views of climate to global ones. KW - climate change KW - climate services KW - climate visualization KW - connectivity KW - downscaling KW - spherical KW - synopticism KW - zoom Y1 - 2019 U6 - https://doi.org/10.1002/geo2.70 SN - 2054-4049 VL - 6 IS - 1 PB - Wiley-Blackwell CY - Hoboken ER - TY - THES A1 - Böhne, Sebastian T1 - Different degrees of formality T1 - Verschiedene Formalitätsgrade BT - an introduction to the concept and a demonstration of its usefulness BT - Vorstellung des Konzepts und Nachweis seiner Nützlichkeit N2 - In this thesis we introduce the concept of the degree of formality. It is directed against a dualistic point of view, which only distinguishes between formal and informal proofs. This dualistic attitude does not respect the differences between the argumentations classified as informal and it is unproductive because the individual potential of the respective argumentation styles cannot be appreciated and remains untapped. This thesis has two parts. In the first of them we analyse the concept of the degree of formality (including a discussion about the respective benefits for each degree) while in the second we demonstrate its usefulness in three case studies. In the first case study we will repair Haskell B. Curry's view of mathematics, which incidentally is of great importance in the first part of this thesis, in light of the different degrees of formality. In the second case study we delineate how awareness of the different degrees of formality can be used to help students to learn how to prove. Third, we will show how the advantages of proofs of different degrees of formality can be combined by the development of so called tactics having a medium degree of formality. Together the three case studies show that the degrees of formality provide a convincing solution to the problem of untapped potential. N2 - In dieser Dissertation stellen wir das Konzept der Formalitätsgrade vor, welches sich gegen eine dualistische Sichtweise richtet, die nur zwischen formalen und informalen Beweisen unterscheidet. Letztere Sichtweise spiegelt nämlich die Unterschiede zwischen den als informal klassifizierten Argumentationen nicht wieder und ist außerdem unproduktiv, weil sie nicht in der Lage ist, das individuelle Potential der jeweiligen Argumentationsstile wertzuschätzen und auszuschöpfen. Die Dissertation hat zwei Teile. Im ersten analysieren wir das Konzept der Formalitätsgrade (eine Diskussion über die Vorteile der jeweiligen Grade eingeschlossen), während wir im zweiten Teil die Nützlichkeit der Formalitätsgrade anhand von drei Fallbeispielen nachweisen. Im ersten von diesen werden wir Haskell B. Currys Sichtweise zur Mathematik, die nebenbei bemerkt von größter Wichtigkeit für den ersten Teil der Dissertation ist, mithilfe der verschiedenen Formalitätsgrade reparieren. Im zweiten Fallbeispiel zeigen wir auf, wie die Beachtung der verschiedenen Formalitätsgrade den Studenten dabei helfen kann, das Beweisen zu erlernen. Im letzten Fallbeispiel werden wir dann zeigen, wie die Vorteile von Beweisen verschiedener Formalitätsgrade durch die Anwendung sogenannter Taktiken mittleren Formalitätsgrades kombiniert werden können. Zusammen zeigen die drei Fallbeispiele, dass die Formalitätsgrade eine überzeugende Lösung für das Problem des ungenutzten Potentials darstellen. KW - argumentation KW - Coq KW - Curry KW - degree of formality KW - formalism KW - logic KW - mathematics education KW - philosophy of mathematics KW - proof KW - proof assistant KW - proof environment KW - tactic KW - Argumentation KW - Beweis KW - Beweisassistent KW - Beweisumgebung KW - Coq KW - Curry KW - Formalismus KW - Formalitätsgrad KW - Logik KW - Mathematikdidaktik KW - Mathematikphilosophie KW - Taktik Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-423795 N1 - CCS -> Applied computing -> Education -> Interactive learning environments CCS -> Theory of computation -> Logic CCS -> Computing methodologies -> Symbolic and algebraic manipulation -> Symbolic and algebraic algorithms -> Theorem proving algorithms ER - TY - THES A1 - Jadhav Sudam, Sagar T1 - Metabolic regulation and key genes of tomato secondary metabolism T1 - Stoffwechselregulation und Schlüsselgene des Sekundärstoffwechsels in Tomaten N2 - Domestication syndrome has resulted in the large loss of genetic variation of crop plants. Because of such genetic loss, productivity of various beneficial secondary (specialized) metabolites that protect against abiotic/biotic stresses, has been narrowed in many domesticated crops. Many key regulators or structural genes of secondary metabolic pathways in the domesticated as well as wild tomatoes are still largely unknown. In recent studies, metabolic quantitative trait loci (mQTL) analysis using the population of introgression lines (ILs), each containing a single introgression from Solanum pennellii (wild tomato) in the genetic background of domesticated tomato (M82, Solanum lycopersicum), has been used for investigation of metabolic regulation and key genes involved in both primary and secondary metabolism. In this thesis, three research projects, i) understanding of metabolic linkage between branched chain amino acids (BCAAs) and secondary metabolism using antisense lines of BCAAs metabolic genes, ii) investigation of novel key genes involved in tomato secondary metabolism and fruit ripening, iii) mapping of drought stress responsive mQTLs in tomato, are presented and discussed. In the first part, metabolic linkage between leucine and secondary metabolism is investigated by analyzing antisense lines of four key genes (ketol-acid reductoisomerase, KARI; dihydroxy-acid dehydratase, DHAD; isopropylmalate dehydratase, IPMD and branched chain aminotransferases1, BCAT1) found previously in mQTL of leucine contents. Obtained results indicate that KARI might be a rate limiting enzyme for iC5 acyl-sucrose synthesis in young leaf but not in red ripe fruits. By integrating obtained results with previous reports, inductive metabolic linkage between BCAAs and other secondary metabolic pathways at DHAD transcriptional levels in fruit is proposed. In the second part, candidate genes that are involved in secondary metabolism and fruit ripening in tomato were found by the approach of expression quantitative trait loci (eQTL) analysis. To predict functions of those candidate genes, functional validation by virus induced gene silencing and transient overexpression were performed. Results obtained by analyzing T0 overexpression and artificial miRNA lines for some of those candidates confirm their predicted functions, for example involved in fruit ripening (WD40, Solyc04g005020) and iC5 acyl-sucrose synthesis (P450, Solyc03g111940). In the third part, mapping of drought stress responsive mQTLs was performed using 57 S. pennellii ILs population. Evaluation of genetic architecture of mQTL analysis resulted in identifying drought responsive ILs (11-2, 8-3-1, 10-1-1 and 3-1). Location of well characterized regulators in these ILs helped to filter potential new key genes involved in drought stress tolerance. Obtained results suggests us our approaches could be viable for narrowing down potential candidates involved in creating interspecific variation in secondary metabolite content and at the level of fruit ripening. N2 - Das Domestikationssyndrom hat zu einem großen Verlust an genetischer Variation von Kulturpflanzen geführt. Aufgrund dieses genetischen Verlustes ist die Produktivität verschiedener nützlicher, sekundärer (spezialisierter) Metabolite, die gegen abiotische/biotische Belastungen schützen, in vielen domestizierten Nutzpflanzen eingeschränkt worden. Viele Schlüsselregulatoren oder Strukturgene des Sekundärstoffwechsels sind sowohl in den domestizierten als auch in den wilden Tomaten noch weitgehend unbekannt. In neueren Studien wurde die mQTL-Analyse (metabolic quantitative trait loci) durchgeführt, unter Verwendung der Solanum pennellii Introgressionslinienpopulation (ILs), um Stoffwechselregulation und Schlüsselgene zu untersuchen, die sowohl am Primär- als auch am Sekundärstoffwechsel beteiligt sind. In dieser Doktorarbeit werden drei Forschungsprojekte vorgestellt und diskutiert, i) Verständnis der metabolischen Verbindung zwischen verzweigtkettigen Aminosäuren (BCAAs branched-chain amino acids) und dem Sekundärstoffwechsel unter Verwendung von Antisense-Linien von metabolischen Genen der BCAAs, ii) Untersuchung neuer Schlüsselgene im Tomaten-Sekundärstoffwechsel und Fruchtreifung, iii ) Kartierung mQTLs in Tomaten, die auf Trockenstress ansprechen. Im ersten Teil wird die metabolische Verknüpfung zwischen Leucin und dem Sekundärmetabolismus untersucht, indem Antisense-Linien von vier Schlüsselgenen (Ketol-Säure-Reduktoisomerase, KARI; Dihydroxysäuredehydratase, DHAD; Isopropylmalatdehydratase, IPMD und verzweigtkettige Aminotransferasen1, BCAT1) untersucht werden, die in mQTLs für den Leucingehalt gefunden wurden. Die Ergebnisse weisen darauf hin, dass KARI ein geschwindigkeitslimitierendes Enzym für die iC5-Acyl-Saccharosesynthese in jungen Blättern, aber nicht in roten reifen Früchten sein könnte. Durch Integration der erhaltenen Ergebnisse mit früheren Berichten wird eine induktive metabolische Verbindung zwischen BCAAs und anderen sekundären Stoffwechselwegen auf DHAD-Transkriptionsebene in Früchten vorgeschlagen. Im zweiten Teil wurden Kandidatengene gefunden, die am sekundären Metabolismus und der Fruchtreife von Tomaten beteiligt sind, durch den Ansatz der eQTL-Analyse (expression QTL). Um die Funktionen dieser Kandidatengene vorherzusagen, wurde eine funktionelle Validierung durch virusinduziertes Gen-Silencing und transiente Überexpression durchgeführt. Ergebnisse, die durch Analyse von T0-Überexpressions- und künstlichen miRNA-Linien für einige dieser Kandidatengene erhalten wurden, bestätigen ihre vorhergesagten Funktionen, z. B. Beteiligt an Fruchtreifung (WD40, Solyc04g005020) und iC5-Acylsaccharosesynthese (P450, Solyc03g111940). Im dritten Teil wurde die Kartierung von auf Trockenstress ansprechenden mQTLs unter Verwendung von 57 S. pennellii-IL-Populationen durchgeführt. Die Evaluierung der genetischen Architektur der mQTL-Analyse führte zur Identifizierung von ILs, die auf Trockenheit ansprechen (11-2, 8-3-1, 10-1-1 und 3-1). Die Position gut charakterisierter Regulatoren in diesen ILs half dabei, potenzielle neue Schlüsselregulatoren, die an der Toleranz gegenüber Trockenstress beteiligt sind, heraus zu filtern. Die erhaltenen Ergebnisse legen nahe, dass unsere Ansätze geeignet sein könnten, potentielle Kandidatengene einzugrenzen, die interspezifische Unterschiede im Sekundärmetabolitengehalt verursachen. KW - metabolic regulation KW - expression Quantitative Trait Loci KW - metabolic Quantitative Trait Loci KW - branched chain amino acids KW - Introgression Lines KW - Stoffwechselregulation KW - verzweigtkettige Aminosäuren Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-424478 ER - TY - THES A1 - Wolf, Mathias Johannes T1 - The role of partial melting on trace element and isotope systematics of granitic melts T1 - Die Bedeutung partieller Schmelzbildung für die Spurenelement- und Isotopensystematik granitischer Schmelzen N2 - Partial melting is a first order process for the chemical differentiation of the crust (Vielzeuf et al., 1990). Redistribution of chemical elements during melt generation crucially influences the composition of the lower and upper crust and provides a mechanism to concentrate and transport chemical elements that may also be of economic interest. Understanding of the diverse processes and their controlling factors is therefore not only of scientific interest but also of high economic importance to cover the demand for rare metals. The redistribution of major and trace elements during partial melting represents a central step for the understanding how granite-bound mineralization develops (Hedenquist and Lowenstern, 1994). The partial melt generation and mobilization of ore elements (e.g. Sn, W, Nb, Ta) into the melt depends on the composition of the sedimentary source and melting conditions. Distinct source rocks have different compositions reflecting their deposition and alteration histories. This specific chemical “memory” results in different mineral assemblages and melting reactions for different protolith compositions during prograde metamorphism (Brown and Fyfe, 1970; Thompson, 1982; Vielzeuf and Holloway, 1988). These factors do not only exert an important influence on the distribution of chemical elements during melt generation, they also influence the volume of melt that is produced, extraction of the melt from its source, and its ascent through the crust (Le Breton and Thompson, 1988). On a larger scale, protolith distribution and chemical alteration (weathering), prograde metamorphism with partial melting, melt extraction, and granite emplacement are ultimately depending on a (plate-)tectonic control (Romer and Kroner, 2016). Comprehension of the individual stages and their interaction is crucial in understanding how granite-related mineralization forms, thereby allowing estimation of the mineralization potential of certain areas. Partial melting also influences the isotope systematics of melt and restite. Radiogenic and stable isotopes of magmatic rocks are commonly used to trace back the source of intrusions or to quantify mixing of magmas from different sources with distinct isotopic signatures (DePaolo and Wasserburg, 1979; Lesher, 1990; Chappell, 1996). These applications are based on the fundamental requirement that the isotopic signature in the melt reflects that of the bulk source from which it is derived. Different minerals in a protolith may have isotopic compositions of radiogenic isotopes that deviate from their whole rock signature (Ayres and Harris, 1997; Knesel and Davidson, 2002). In particular, old minerals with a distinct parent-to-daughter (P/D) ratio are expected to have a specific radiogenic isotope signature. As the partial melting reaction only involves selective phases in a protolith, the isotopic signature of the melt reflects that of the minerals involved in the melting reaction and, therefore, should be different from the bulk source signature. Similar considerations hold true for stable isotopes. N2 - Partielle Schmelzbildung ist ein zentraler Prozess für die geochemische Differentiation der Erdkruste (Vielzeuf et al., 1990). Die Umverteilung chemischer Elemente während der Schmelzbildung beeinflusst die Zusammensetzung der oberen und unteren Erdkruste entscheidend und stellt einen Mechanismus zur Konzentration und zum Transport chemischer Elemente dar. Das Verständnis der diversen Prozesse und der kontrollierenden Faktoren ist deshalb nicht nur von wissenschaftlichem Interesse sondern auch von ökonomischer Bedeutung um die Nachfrage für seltene Metalle zu decken. Die Umverteilung von Haupt- und Spurenelementen während des partiellen Aufschmelzens ist ein entscheidender Schritt für das Verständnis wie sich granitgebundene Lagerstätten bilden (Hedenquist and Lowenstern, 1994). Die Schmelzbildung und die Mobilisierung von Erz-Elementen (z. B. Sn, W, Nb, Ta) in die Schmelze hängt von der Zusammensetzung der sedimentären Ausgangsgesteine und den Schmelzbedingungen ab. Verschiedene Ausgangsgesteine haben aufgrund ihrer Ablagerungs- und Verwitterungsgeschichte unterschiedliche Zusammensetzungen. Dieses spezifische geochemische „Gedächtnis“ resultiert in unterschiedlichen Mineralparagenesen und Schmelzreaktionen in verschiedenen Ausgangsgesteinen während der prograden Metamorphose. (Brown and Fyfe, 1970; Thompson, 1982; Vielzeuf and Holloway, 1988). Diese Faktoren haben nicht nur einen wichtigen Einfluss auf die Verteilung chemischer Elemente während der Schmelzbildung, sie beeinflussen auch das Volumen an Schmelze, die Extraktion der Schmelze aus dem Ausgangsgestein und deren Aufstieg durch die Erdkruste (Le Breton and Thompson, 1988). Auf einer grösseren Skala unterliegen die Verteilung der Ausgangsgesteine und deren chemische Alteration (Verwitterung), die prograde Metamorphose mit partieller Schmelzbildung, Schmelzextraktion und die Platznahme granitischer Intrusionen einer plattentektonischen Kontrolle. Das Verständnis der einzelnen Schritte und deren Wechselwirkungen ist entscheidend um zu verstehen wie granitgebunden Lagerstätten entstehen und erlaubt es, das Mineralisierungspotential bestimmter Gebiete abzuschätzen. Partielles Aufschmelzen beeinflusst auch die Isotopensystematik der Schmelze und des Restites. Die Zusammensetzungen radiogener und stabiler Isotopen von magmatischen Gesteinen werden im Allgemeinen dazu verwendet um deren Ursprungsgesteine zu identifizieren oder um Mischungsprozesses von Magmen unterschiedlichen Ursprunges zu quantifizieren (DePaolo and Wasserburg, 1979; Lesher, 1990; Chappell, 1996). Diese Anwendungen basieren auf der fundamentalen Annahme, dass die Isotopenzusammensetzung der Schmelze derjenigen des Ausgangsgesteines entspricht. Unterschiedliche Minerale in einem Gestein können unterschiedliche, vom Gesamtgestein abweichende, Isotopenzusammensetzungen haben (Ayres and Harris, 1997; Knesel and Davidson, 2002). Insbesondere für alte Minerale, mit einem unterschiedlichen Mutter-Tochter Nuklidverhältnis, ist eine spezifische Isotopenzusammensetzung zu erwarten. Da im partiellen Schmelzprozess nur bestimmte Minerale eines Gesteines involviert sind, entspricht die Isotopenzusammensetzung der Schmelze derjenigen der Minerale welche an der Schmelzreaktion teilnehmen. Daher sollte die Isotopenzusammensetzung der Schmelze von derjenigen des Ursprungsgesteines abweichen. Ähnliche Überlegungen treffen auch für stabile Isotopen zu. KW - geochemistry KW - trace elements KW - radiogenic isotopes KW - stable isotopes KW - resources KW - Sn Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-423702 ER - TY - CHAP A1 - Thorau, Christian T1 - "What ought to be heard" : touristic listening and the guided ear T2 - The Oxford handbook of music listening in the 19th and 20th centuries Y1 - 2019 SN - 978-0-19-046696-1 SP - 207 EP - 227 PB - Oxford University Press CY - New York ER - TY - BOOK ED - Thorau, Christian ED - Ziemer, Hansjacob T1 - The Oxford handbook of music listening in the 19th and 20th centuries N2 - An idealized image of European concert-goers has long prevailed in historical overviews of the nineteenth and twentieth centuries. This act of listening was considered to be an invisible and amorphous phenomenon, a naturally given mode of perception. This narrative influenced the conditions of listening from the selection of repertoire to the construction of concert halls and programmes. However, as listening moved from the concert hall to the opera house, street music, and jazz venues, new and visceral listening traditions evolved. In turn, the art of listening was shaped by phenomena of the modern era including media innovation and commercialization. This Handbook asks whether, how, and why practices of music listening changed as the audience moved from pleasure gardens and concert venues in the eighteenth century to living rooms in the twentieth century, and mobile devices in the twenty-first. Through these questions, chapters enable a differently conceived history of listening and offer an agenda for future research. Y1 - 2019 SN - 978-0-19-046696-1 PB - Oxford University Press CY - New York ER - TY - RPRT A1 - Roggeband, Conny T1 - International women’s rights BT - Progress under attack? T2 - KFG Working Paper Series N2 - This paper explores current contestations of women’s rights and the implications thereof for international legislation. While contestation over women’s rights is a far from new phenomenon, over the past two decades opposition to gender equality has become better organized at the transnational level, mobilizing a dispersed set of state and non-state actors, and is becoming more successful in halting the progress of women’s rights. I argue that the position of oppositional actors vis-à-vis women rights activism appears to be strengthened by two recent political developments: democratic backsliding and the closure of civic space. Some preliminary findings show how these interrelated developments lead to an erosion of women’s rights at the national level. Governments use low key tactics to dismantle institutional and implementation arrangements and sideline women’s organisations. Next, I explore the implications of these developments for gender equality norms at the national and international level. The active strategy of counter norming adopted by conservative and religious state and non-state actors, designed to circumvent and also undermine Western norms, is increasingly successful. In addition to this, the threatened position of domestic actors monitoring compliance of international treaties, makes the chances of backsliding on international commitments much higher. T3 - KFG Working Paper Series - 26 Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-423887 SN - 2509-3770 SN - 2509-3762 IS - 26 ER - TY - RPRT A1 - de Wet, Erika T1 - Entrenching international values through positive law BT - The (limited) effect of peremptory norms T2 - KFG Working Paper Series N2 - Underpinning a legal system with certain values and helping to resolve norm conflicts is in domestic legal systems usually achieved through hierarchical superiority of certain norms of a constitutional nature. The present paper examines the question whether jus cogens can discharge this function within the traditionally horizontal and decentralized international legal order. In so doing, it commences with an overview of the historical origins of peremptory norms in legal scholarship, followed by its endorsement by positive law and courts and tribunals. This analysis illustrates that there are lingering uncertainties pertaining to the process of identification of peremptory norms. Even so, the concept has been invoked in State executive practice (although infrequently) and has been endorsed by various courts. However, such invocation thus far has had a limited impact from a legal perspective. It was mainly confined to a strengthened moral appeal and did in particular not facilitate the resolution of norm conflicts. The contribution further suggests that this limited impact results from the fact that the content of peremptory obligations is either very narrow or very vague. This, in turn, implies a lack of consensus amongst States regarding the content (scope) of jus cogens, including the values underlying these norms. As a result, it is questionable whether the construct of jus cogens is able to provide meaningful legal protection against the erosion of legal norms. It is too rudimentary in character to entrench and stabilize core human rights values as the moral foundation of the international legal order. T3 - KFG Working Paper Series - 25 Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-423859 SN - 2509-3770 SN - 2509-3762 IS - 25 ER - TY - THES A1 - Al Nakeeb, Noah T1 - Self-assembly and crosslinking approaches of double hydrophilic linear-brush block copolymers BT - a biocompatible platform for the next generation of nanoreactors Y1 - 2019 ER - TY - THES A1 - Küçükgöze, Gökhan T1 - Purification and characterization of mouse aldehyde oxidases T1 - Aufreinigung und Charakterisierung von Maus-Aldehyd-Oxidasen N2 - Mouse aldehyde oxidases (mAOXs) have a homodimeric structure and belong to xanthine oxidase family of molybdo-flavoenzymes. In general, each dimer is characterized by three subdomains: a 20 kDa N-terminal 2x[2Fe2S] cluster containing domain, a 40 kDa central FAD-containing domain and an 85 kDa C-terminal molybdenum cofactor (Moco) containing domain. Aldehyde oxidases have a broad substrate specificity including the oxidation of different aldehydes and N-heterocyclic compounds. AOX enzymes are present in mainly all eukaryotes. Four different homologs of AOX were identified to be present with varying numbers among species and rodents like mice and rats contain the highest number of AOX isoenzymes. There are four identified homologs in mouse named mAOX1, mAOX3, mAOX2, and mAOX4. The AOX homologs in mice are expressed in a tissue-specific manner. Expression of mAOX1 and mAOX3 are almost superimposable and predominantly synthesized in liver, lung, and testis. The richest source of mAOX4 is the Harderian gland, which is found within the eye's orbit in tetrapods. Expression of mAOX2 is strictly restricted to the Bowman’s gland, the main secretory organ of the nasal mucosa. In this study, the four catalytically active mAOX enzymes were expressed in a heterologous expression system in Escherichia coli and purified in a catalytically active form. Thirty different structurally related aromatic, aliphatic and N-heterocyclic compounds were used as substrates, and the kinetic parameters of all four mAOX enzymes were directly compared. The results showed that all enzymes can catalyze a broad range of substrates. Generally, no major differences between mAOX1, mAOX3 and mAOX2 were identified and the substrate specificity of mAOX1, mAOX3, and mAOX2 was broader compared to that of mAOX4 since mAOX4 showed no activity with substrates like methoxy-benzaldehydes, phenanthridine, N1-methyl-nicotinamide, and cinnamaldehyde and 4-(dimethylamino)cinnamaldehyde. We investigated differences at the flavin site of the mAOX enzymes by measuring the ability of the four mAOX enzymes to oxidize NADH in the absence of oxygen. NADH was able to reduce only mAOX3. The four mouse AOXs are also characterized by quantitative differences in their ability to produce superoxide radicals. mAOX2 is the enzyme generating the largest rate of superoxide radicals of around 40% in relation to moles of substrate converted and it is followed by mAOX1 with a ratio of 30%. To understand the factors that contribute to the substrate specificity of mAOX4, site-directed mutagenesis was applied to substitute amino acids in the substrate-binding funnel by the ones present in mAOX1, mAOX3, and mAOX2. The amino acids Val1016, Ile1018 and Met1088 were selected as targets. An increase in activity was obtained by the amino acid exchange M1088V in the active site identified to be specific for mAOX4, to the amino acid identified in mAOX3. N2 - Mouse aldehyde oxidases (mAOXs) have a homodimeric structure and belong to xanthine oxidase family of molybdo-flavoenzymes. In general, each dimer is characterized by three subdomains: a 20 kDa N-terminal 2x[2Fe2S] cluster containing domain, a 40 kDa central FAD-containing domain and an 85 kDa C-terminal molybdenum cofactor (Moco) containing domain. Aldehyde oxidases have a broad substrate specificity including the oxidation of different aldehydes and N-heterocyclic compounds. AOX enzymes are present in mainly all eukaryotes. Four different homologs of AOX were identified to be present with varying numbers among species and rodents like mice and rats contain the highest number of AOX isoenzymes. There are four identified homologs in mouse named mAOX1, mAOX3, mAOX2, and mAOX4. The AOX homologs in mice are expressed in a tissue-specific manner. Expression of mAOX1 and mAOX3 are almost superimposable and predominantly synthesized in liver, lung, and testis. The richest source of mAOX4 is the Harderian gland, which is found within the eye's orbit in tetrapods. Expression of mAOX2 is strictly restricted to the Bowman’s gland, the main secretory organ of the nasal mucosa. In this study, the four catalytically active mAOX enzymes were expressed in a heterologous expression system in Escherichia coli and purified in a catalytically active form. Thirty different structurally related aromatic, aliphatic and N-heterocyclic compounds were used as substrates, and the kinetic parameters of all four mAOX enzymes were directly compared. The results showed that all enzymes can catalyze a broad range of substrates. Generally, no major differences between mAOX1, mAOX3 and mAOX2 were identified and the substrate specificity of mAOX1, mAOX3, and mAOX2 was broader compared to that of mAOX4 since mAOX4 showed no activity with substrates like methoxy-benzaldehydes, phenanthridine, N1-methyl-nicotinamide, and cinnamaldehyde and 4-(dimethylamino)cinnamaldehyde. We investigated differences at the flavin site of the mAOX enzymes by measuring the ability of the four mAOX enzymes to oxidize NADH in the absence of oxygen. NADH was able to reduce only mAOX3. The four mouse AOXs are also characterized by quantitative differences in their ability to produce superoxide radicals. mAOX2 is the enzyme generating the largest rate of superoxide radicals of around 40% in relation to moles of substrate converted and it is followed by mAOX1 with a ratio of 30%. To understand the factors that contribute to the substrate specificity of mAOX4, site-directed mutagenesis was applied to substitute amino acids in the substrate-binding funnel by the ones present in mAOX1, mAOX3, and mAOX2. The amino acids Val1016, Ile1018 and Met1088 were selected as targets. An increase in activity was obtained by the amino acid exchange M1088V in the active site identified to be specific for mAOX4, to the amino acid identified in mAOX3. KW - aldehyde oxidase KW - drug metabolism KW - molybdenum cofactor KW - enzyme isoforms KW - enzyme kinetics KW - Aldehyd-oxidase KW - Metabolismus von Medikamenten KW - Molybdänkofaktor KW - Isoenzyme KW - Enzymkinetik Y1 - 2019 ER -