Refine
Has Fulltext
- no (112) (remove)
Year of publication
- 2020 (112) (remove)
Document Type
- Doctoral Thesis (112) (remove)
Keywords
- Digitalisierung (2)
- Migration (2)
- Wissensmanagement (2)
- knowledge management (2)
- 1,6,7,12-Tetraazaperylen (1)
- AIDS (1)
- AMP (1)
- Active Labor Market Programs (1)
- Adviescollege Toetsing Administrative Lasten (1)
- Adviescollege Toetsing Regeldruk (1)
Institute
- Institut für Biochemie und Biologie (14)
- Öffentliches Recht (11)
- Institut für Chemie (9)
- Institut für Anglistik und Amerikanistik (7)
- Historisches Institut (6)
- Institut für Ernährungswissenschaft (6)
- Bürgerliches Recht (5)
- Fachgruppe Betriebswirtschaftslehre (5)
- Institut für Physik und Astronomie (5)
- Strafrecht (5)
Feminist Solidarities after Modulation produces an intersectional analysis of transnational feminist movements and their contemporary digital frameworks of identity and solidarity. Engaging media theory, critical race theory, and Black feminist theory, as well as contemporary feminist movements, this book argues that digital feminist interventions map themselves onto and make use of the multiplicity and ambiguity of digital spaces to question presentist and fixed notions of the internet as a white space and technologies in general as objective or universal. Understanding these frameworks as colonial constructions of the human, identity is traced to a socio-material condition that emerges with the modernity/colonialism binary. In the colonial moment, race and gender become the reasons for, as well as the effects of, technologies of identification, and thus need to be understood as and through technologies. What Deleuze has called modulation is not a present modality of control, but is placed into a longer genealogy of imperial division, which stands in opposition to feminist, queer, and anti-racist activism that insists on non-modular solidarities across seeming difference. At its heart, Feminist Solidarities after Modulation provides an analysis of contemporary digital feminist solidarities, which not only work at revealing the material histories and affective ""leakages"" of modular governance, but also challenges them to concentrate on forms of political togetherness that exceed a reductive or essentialist understanding of identity, solidarity, and difference.
In der Arbeit „Von der Studienaufnahme bis zum Studienabbruch“ strebt die Autorin an, das Phänomen des Studienabbruchs sowohl handlungstheoretisch einzubetten als auch längsschnittlich zu untersuchen und damit einen wichtigen Beitrag für die Hochschulforschung zu leisten. Die übergeordneten Fragestellungen der Arbeit lauten „Wie kann der Entscheidungsprozess zum Studienabbruch handlungstheoretisch beschrieben werden?“ und „Inwieweit kann ein Studienabbruch durch die Veränderung wesentlicher Einflussfaktoren, wie des studentischen Frames, empirisch erklärt werden?“. Zur Beantwortung dieser zwei übergeordneten Fragen wählt die Autorin die integrative Handlungstheorie und das Modell der Frame-Selektion von Hartmut Esser und Clemens Kroneberg. Anhand dieser entwickelt die Autorin im theoretischen Teil ihrer Arbeit ein Modell des Reframings in der Studieneingangsphase, was den Prozess der Entscheidung zum Studienabbruch bzw. Studienverbleib beschreibt. Die Wahl der Theorie begründet sie durch den aktuellen Forschungsstand zu Bildungsentscheidungen aus der soziologischen Bildungsforschung. Im Rahmen des abgeleiteten Modells stellt der Studienabbruch eine weitere allgemeine Bildungsentscheidung dar, die durch ein Reframing des Interpretationsrahmens der Studierenden (das sogenannte Frame) in der Studieneingangsphase verursacht werden kann. Dabei liegt der Fokus des Modells auf dem Prozess der Entscheidung, indem beschrieben wird, wie und durch welche Faktoren das ursprüngliche Frame, mit dem die Studienentscheidung getroffen wurde, in der Studieneingangsphase sich verändert und infolgedessen es zu einer wiederholten Bildungsentscheidung kommt. Mit dem empirischen Teil der Arbeit verfolgt die Autorin zwei Ziele. Zum einen werden die theoretischen Annahmen aus dem Modell zum Reframing in der Studieneingangsphase anhand von Wiederholungsbefragungen von Studierenden überprüft. Zum anderen untersucht die Autorin mithilfe dieser Daten die Entscheidung zum Studienabbruch für den deutschen Kontext erstmalig im Längsschnitt. Die empirischen Untersuchungen umfassen vier Teilstudien und orientieren sich chronologisch am theoretischen Modell. So wird zunächst in der Teilstudie I die messtheoretische Güte der Operationalisierung des studentischen Frames überprüft und anschließend Bestimmungsfaktoren des anfänglichen studentischen Frames zur Studienaufnahme betrachtet. Die Teilstudie II bietet eine Untersuchung zum Match zwischen den anfänglichen Erwartungen und der vorgefundenen Studienrealität in der Studieneingangsphase, wobei das Match anhand von individuellen und institutionellen Faktoren erklärt wird. Der Fokus der Teilstudie III liegt auf dem Ausmaß und den Bedingungsfaktoren der Veränderungen des Frames in der Studieneingangsphase. Letztlich bietet die Teilstudie IV erstmalig für die deutsche Hochschulforschung eine längsschnittliche Perspektive mit dem Fokus auf die zeitliche Veränderung des studentischen Frames zur Erklärung des Studienabbruchs und Studienverbleibs. Im Fazit diskutiert die Autorin Implikationen für die Weiterentwicklung des vorgeschlagenen theoretischen Modells, Implikationen für die zukünftige Forschung zum Studienabbruch und Implikationen für die Praxis an den Hochschulen zur Gestaltung der Studieneingangsphase und Prävention von Studienabbrüchen. Dabei kann sie vor allem für die Hochschulpraxis fünf große Themenbereiche identifizieren: der Umfang von unerfüllten Erwartungen der Studierenden; die Heterogenität der studentischen Frames bei der Studienaufnahme; der große Anteil an Studierenden, die mindestens einen Studiengangwechsel vollzogen haben; die phasenspezifische Veränderung des studentischen Frames und ihre Bedeutung für die Stabilisierung bzw. Destabilisierung der Studienentscheidung sowie die Bedeutung der inhaltlichen und qualitativen Gestaltung der Studieneingangsphase und des Studiums. Letztlich spricht sich die Autorin auch für eine Entstigmatisierung des Studienabbruchs aus.
From self-help books and nootropics, to self-tracking and home health tests, to the tinkering with technology and biological particles – biohacking brings biology, medicine, and the material foundation of life into the sphere of »do-it-yourself«. This trend has the potential to fundamentally change people's relationship with their bodies and biology but it also creates new cultural narratives of responsibility, authority, and differentiation. Covering a broad range of examples, this book explores practices and representations of biohacking in popular culture, discussing their ambiguous position between empowerment and requirement, promise and prescription.
The goal of regenerative medicine is to guide biological systems towards natural healing outcomes using a combination of niche-specific cells, bioactive molecules and biomaterials. In this regard, mimicking the extracellular matrix (ECM) surrounding cells and tissues in vivo is an effective strategy to modulate cell behaviors. Cellular function and phenotype is directed by the biochemical and biophysical signals present in the complex 3D network of ECMs composed mainly of glycoproteins and hydrophilic proteoglycans. While cellular modulation in response to biophysical cues emulating ECM features has been investigated widely, the influence of biochemical display of ECM glycoproteins mimicking their presentation in vivo is not well characterized. It remains a significant challenge to build artificial biointerfaces using ECM glycoproteins that precisely match their presentation in nature in terms of morphology, orientation and conformation. This challenge becomes clear, when one understands how ECM glycoproteins self-assemble in the body. Glycoproteins produced inside the cell are secreted in the extra-cellular space, where they are bound to the cell membrane or other glycoproteins by specific interactions. This leads to elevated local concentration and 2Dspatial confinement, resulting in self-assembly by the reciprocal interactions arising from the molecular complementarity encoded in the glycoprotein domains. In this thesis, air-water (A-W) interface is presented as a suitable platform, where self-assembly parameters of ECM glycoproteins such as pH, temperature and ionic strength can be controlled to simulate in vivo conditions (Langmuir technique), resulting in the formation of glycoprotein layers with defined characteristics. The layer can be further compressed with surface barriers to enhance glycoprotein-glycoprotein contacts and defined layers of glycoproteins can be immobilized on substrates by horizontal lift and touch method, called Langmuir-Schäfer (LS) method. Here, the benefit of Langmuir and LS methods in achieving ECM glycoprotein biointerfaces with controlled network morphology and ligand density on substrates is highlighted and contrasted with the commonly used (glyco)protein solution deposition (SO) method on substrates. In general, the (glyco)protein layer formation by SO is rather uncontrolled, influenced strongly by (glyco)protein-substrate interactions and it results in multilayers and aggregations on substrates, while the LS method results in (glyco)proteins layers with a more homogenous presentation. To achieve the goal of realizing defined ECM layers on substrates, ECM glycoproteins having the ability to self-assemble were selected: Collagen-IV (Col-IV) and fibronectin (FN). Highly packed FN layer with uniform presentation of ligands was deposited on polydimethysiloxane VIII (PDMS) by LS method, while a heterogeneous layer was formed on PDMS by SO with prominent aggregations visible. Mesenchymal stem cells (MSC) on PDMS equipped with FN by LS exhibited more homogeneous and elevated vinculin expression and weaker stress fiber formation than on PDMS equipped with FN by SO and these divergent responses could be attributed to the differences in glycoprotein presentation at the interface. Col-IV are scaffolding components of specialized ECM called basement membranes (BM), and have the propensity to form 2D networks by self-polymerization associated with cells. Col- IV behaves as a thin-disordered network at the A-W interface. As the Col-IV layer was compressed at the A-W interface using trough barriers, there was negligible change in thickness (layer thickness ~ 50 nm) or orientation of molecules. The pre-formed organization of Col-IV was transferred by LS method in a controlled fashion onto substrates meeting the wettability criterion (CA ≤ 80°). MSC adhesion (24h) on PET substrates deposited with Col-IV LS films at 10, 15 and 20 mN·m-1 surface pressures was (12269.0 ± 5856.4) cells for LS10, (16744.2 ± 1280.1) cells for LS15 and (19688.3 ± 1934.0) cells for LS20 respectively. Remarkably, by selecting the surface areal density of Col-IV on the Langmuir trough on PET, there is a linear increase between the number of adherent MSCs and the Col-IV ligand density. Further, FN has the ability to self-stabilize and form 2D networks (even without compression) while preserving native β-sheet structure at the A-W interface on a defined subphase (pH = 2). This provides the possibility to form such layers on any vessel (even on standard six-well culture plates) and the cohesive FN layers can be deposited by LS transfer, without the need for expensive LB instrumentation. Multilayers of FN can be immobilized on substrates by this approach, as easily as Layer-by-Layer method, even without the need for secondary adlayer or activated bare substrate. Thus, this facile glycoprotein coating strategy approach is accessible to many researchers to realize defined FN films on substrates for cell culture. In conclusion, Langmuir and LS methods can create biomimetic glycoprotein biointerfaces on substrates controlling aspects of presentation such as network morphology and ligand density. These methods will be utilized to produce artificial BM mimics and interstitial ECM mimics composed of more than one ECM glycoprotein layer on substrates, serving as artificial niches instructing stem cells for cell-replacement therapies in the future.
Matthias Walden
(2020)
Matthias Walden (1927–1984) war einer der Vertreter eines politischen Neuanfangs im Journalismus in Deutschland nach 1945. Im Kern seines politischen Denkens stand die Verteidigung der liberalen Demokratie, deren ideellen Gehalt Walden sowohl durch eine personelle Kontinuität in der Bundesrepublik Deutschland zum Nationalsozialismus als auch durch die von ihm als Anbiederung empfundene Neue Ostpolitik und den gesellschaftlichen Protest der 1960er und 1970er Jahre in Gefahr sah.
Als profilierter Leitartikler wurde er vor allem für den Verlag Axel Springer zu einem intellektuellen Impulsgeber. Walden war überzeugt, Diktaturen und totalitäre Gesellschaftsentwürfe sähen immer nur so aus, als wären sie für die Ewigkeit gemacht. Im Kalten Krieg gab ihm gerade die Unmenschlichkeit der kommunistischen Regime die Gewissheit, dass diese einst verschwinden würden.
Nils Lange legt mit seiner intellektuellen Biographie von Matthias Walden die erste umfassende Arbeit über diesen streitbaren Journalisten vor. Er arbeitet sowohl die politischen als auch die ideengeschichtlichen Ursprünge von Waldens Denken heraus.
Die Arbeit beleuchtet das besondere öffentliche Interesse an der Strafverfolgung in seiner Gesamtheit. Im ersten Teil der Arbeit werden insbesondere die formellen Aspekte rund um das besondere öffentliche Interesse untersucht. Im Zentrum stehen hierbei die besonders problematischen Aspekte der Frage nach der Prozessvoraussetzung und der gerichtlichen Überprüfbarkeit. Aufgezeigt wird, dass das besondere öffentliche Interesse tatsächlich vorliegen und dessen Vorliegen vom mit der Sache befassten Gericht vollständig überprüft werden muss. Im zweiten Teil geht es um die inhaltliche Auslegung des besonderen öffentlichen Interesses. Nachdem kurz der derzeitige Forschungsstand aufgezeigt wird, wird zunächst die Frage erörtert, ob das besondere öffentliche als ein gegenüber dem öffentlichen Interesse gesteigerter Begriff anzusehen ist, was verneint wird. Anschließend wird der eigene Auslegungsansatz erarbeitet, der das besondere öffentliche Interesse als Ergebnis einer Abwägung begreift.
Die Aufgabe der Selbstregulierung der Presse wird in Deutschland vom Deutschen Presserat wahrgenommen. Dieser sieht sich seit seiner Gründung fortwährender Kritik ausgesetzt. Die Arbeit geht der Frage nach, ob der Deutsche Presserat mit seiner bisherigen Tätigkeit den Ansprüchen an eine erfolgreiche Selbstregulierung gerecht wird. Sodann werden elf Lösungsvorschläge auf ihre rechtliche Umsetzbarkeit und ihre Auswirkungen auf die Pressekontrolle in Deutschland untersucht. Zudem wird das britische Modell der Presseselbstkontrolle mit dem deutschen verglichen, um Unterschiede und Gemeinsamkeiten aufzuzeigen, sowie Anregungen und Verbesserungsvorschläge für die Zukunft zu erforschen. Durch ähnliche Strukturen am Anfang ihres Entstehens und das größtenteils parallele Bestehen von Presseräten in beiden Ländern eignet sich explizit das britische Modell für einen Vergleich mit dem Deutschen Presserat.
Die Auswirkungen der reformierten Psychotherapierichtlinie auf die ambulante Patentenversorgung
(2020)
Subsea permafrost is perennially cryotic earth material that lies offshore. Most submarine permafrost is relict terrestrial permafrost beneath the Arctic shelf seas, was inundated after the last glaciation, and has been warming and thawing ever since. It is a reservoir and confining layer for gas hydrates and has the potential to release greenhouse gases and affect global climate change. Furthermore, subsea permafrost thaw destabilizes coastal infrastructure. While numerous studies focus on its distribution and rate of thaw over glacial timescales, these studies have not been brought together and examined in their entirety to assess rates of thaw beneath the Arctic Ocean. In addition, there is still a large gap in our understanding of sub-aquatic permafrost processes on finer spatial and temporal scales. The degradation rate of subsea permafrost is influenced by the initial conditions upon submergence. Terrestrial permafrost that has already undergone warming, partial thawing or loss of ground ice may react differently to inundation by seawater compared to previously undisturbed ice-rich permafrost. Heat conduction models are sufficient to model the thaw of thick subsea permafrost from the bottom, but few studies have included salt diffusion for top-down chemical degradation in shallow waters characterized by mean annual cryotic conditions on the seabed. Simulating salt transport is critical for assessing degradation rates for recently inundated permafrost, which may accelerate in response to warming shelf waters, a lengthening open water season, and faster coastal erosion rates. In the nearshore zone, degradation rates are also controlled by seasonal processes like bedfast ice, brine injection, seasonal freezing under floating ice conditions and warm freshwater discharge from large rivers. The interplay of all these variables is complex and needs further research. To fill this knowledge gap, this thesis investigates sub-aquatic permafrost along the southern coast of the Bykovsky Peninsula in eastern Siberia. Sediment cores and ground temperature profiles were collected at a freshwater thermokarst lake and two thermokarst lagoons in 2017. At this site, the coastline is retreating, and seawater is inundating various types of permafrost: sections of ice-rich Pleistocene permafrost (Yedoma) cliffs at the coastline alternate with lagoons and lower elevation previously thawed and refrozen permafrost basins (Alases). Electrical resistivity surveys with floating electrodes were carried out to map ice-bearing permafrost and taliks (unfrozen zones in the permafrost, usually formed beneath lakes) along the diverse coastline and in the lagoons. Combined with the borehole data, the electrical resistivity results permit estimation of contemporary ice-bearing permafrost characteristics, distribution, and occasionally, thickness. To conceptualize possible geomorphological and marine evolutionary pathways to the formation of the observed layering, numerical models were applied. The developed model incorporates salt diffusion and seasonal dynamics at the seabed, including bedfast ice. Even along coastlines with mean annual non-cryotic boundary conditions like the Bykovsky Peninsula, the modelling results show that salt diffusion minimizes seasonal freezing of the seabed, leading to faster degradation rates compared to models without salt diffusion. Seasonal processes are also important for thermokarst lake to lagoon transitions because lagoons can generate cold hypersaline conditions underneath the ice cover. My research suggests that ice-bearing permafrost can form in a coastal lagoon environment, even under floating ice. Alas basins, however, may degrade more than twice as fast as Yedoma permafrost in the first several decades of inundation. In addition to a lower ice content compared to Yedoma permafrost, Alas basins may be pre-conditioned with salt from adjacent lagoons. Considering the widespread distribution of thermokarst in the Arctic, its integration into geophysical models and offshore surveys is important to quantify and understand subsea permafrost degradation and aggradation. Through numerical modelling, fieldwork, and a circum-Arctic review of subsea permafrost literature, this thesis provides new insights into sub-aquatic permafrost evolution in saline coastal environments.
Die Ordnung der Religionen
(2020)
Der römische Adlige und Humanist Pietro Della Valle bereist von 1614 bis 1626 das Osmanische Reich, Persien und Indien. In einer Zeit des Umbruchs sucht er nach neuen Allianzen für Rom: Gegen die Reformatoren will er die Einheit mit den orientalischen Christen wiederherstellen. Gegen die Osmanen sucht er ein Bündnis mit dem schiitischen Schah Abbas I. zu schließen. Sein Reisebericht, die „Viaggi“ (3 Teile, 1650-63), dokumentiert seine Ambitionen und enthält umfangreiche Erläuterungen zu vielen Religionen Asiens, die damals wie heute im Zentrum des Interesses stehen.
In der Form einer Begriffs- und Ideengeschichte untersuche ich in den „Viaggi“, welche Rolle Religion in den damaligen Auseinandersetzungen spielt und wie sich Della Valle mit der großen religiösen Vielfalt Asiens auseinandersetzt. Welche Hoffnungen und Befürchtungen verbindet er mit den verschiedenen Religionen? Welche Strategien verfolgt er in Bezug auf sie? Wo zieht er Grenzen und wo baut er Brücken?
Recent advances in microscopy have led to an improved visualization of different cell processes. Yet, this also leads to a higher demand of tools which can process images in an automated and quantitative fashion. Here, we present two applications that were developed to quantify different processes in eukaryotic cells which rely on the organization and dynamics of the cytoskeleton.. In plant cells, microtubules and actin filaments form the backbone of the cytoskeleton. These structures support cytoplasmic streaming, cell wall organization and tracking of cellular material to and from the plasma membrane. To better understand the underlying mechanisms of cytoskeletal organization, dynamics and coordination, frameworks for the quantification are needed. While this is fairly well established for the microtubules, the actin cytoskeleton has remained difficult to study due to its highly dynamic behaviour. One aim of this thesis was therefore to provide an automated framework to quantify and describe actin organization and dynamics. We used the framework to represent actin structures as networks and examined the transport efficiency in Arabidopsis thaliana hypocotyl cells. Furthermore, we applied the framework to determine the growth mode of cotton fibers and compared the actin organization in wild-type and mutant cells of rice. Finally, we developed a graphical user interface for easy usage. Microtubules and the actin cytoskeleton also play a major role in the morphogenesis of epidermal leaf pavement cells. These cells have highly complex and interdigitated shapes which are hard to describe in a quantitative way. While the relationship between microtubules, the actin cytoskeleton and shape formation is the object of many studies, it is still not clear how and if the cytoskeletal components predefine indentations and protrusions in pavement cell shapes. To understand the underlying cell processes which coordinate cell morphogenesis, a quantitative shape descriptor is needed. Therefore, the second aim of this thesis was the development of a network-based shape descriptor which captures global and local shape features, facilitates shape comparison and can be used to evaluate shape complexity. We demonstrated that our framework can be used to describe and compare shapes from various domains. In addition, we showed that the framework accurately detects local shape features of pavement cells and outperform contending approaches. In the third part of the thesis, we extended the shape description framework to describe pavement cell shape features on tissue-level by proposing different network representations of the underlying imaging data.
Um ihre ästhetischen und strukturellen Ähnlichkeiten zum Fernsehprogramm aufzudecken, analysiert Christian Richter ausführlich mediale Inszenierungen von Netflix und YouTube. Die Schlagworte »Flow«, »Serialität«, »Liveness« und »Adressierung« dienen dabei als zentrale Orientierungshilfen. Antworten liefern etablierte Fernsehtheorien ebenso wie facettenreiche und triviale Beispiele. Diese reichen vom ZDF-Fernsehgarten und alten Horrorfilmen über den SuperBowl und einsame Bahnfahrten durch Norwegen bis zu BibisBeautyPalace und House of Cards. Am Ende schält sich ein Zustand von FERNSEHEN heraus, der als eine neue Version aufgefasst werden kann.
Organizations continue to assemble and rely upon teams of remote workers as an essential element of their business strategy; however, knowledge processing is particular difficult in such isolated, largely digitally mediated settings. The great challenge for a knowledge-based organization lies not in how individuals should interact using technology but in how to achieve effective cooperation and knowledge exchange. Currently more attention has been paid to technology and the difficulties machines have processing natural language and less to studies of the human aspect—the influence of our own individual cognitive abilities and preferences on the processing of information when interacting online. This thesis draws on four scientific domains involved in the process of interpreting and processing massive, unstructured data—knowledge management, linguistics, cognitive science, and artificial intelligence—to build a model that offers a reliable way to address the ambiguous nature of language and improve workers’ digitally mediated interactions. Human communication can be discouragingly imprecise and is characterized by a strong linguistic ambiguity; this represents an enormous challenge for the computer analysis of natural language. In this thesis, I propose and develop a new data interpretation layer for the processing of natural language based on the human cognitive preferences of the conversants themselves. Such a semantic analysis merges information derived both from the content and from the associated social and individual contexts, as well as the social dynamics that emerge online. At the same time, assessment taxonomies are used to analyze online comportment at the individual and community level in order to successfully identify characteristics leading to greater effectiveness of communication. Measurement patterns for identifying effective methods of individual interaction with regard to individual cognitive and learning preferences are also evaluated; a novel Cyber-Cognitive Identity (CCI)—a perceptual profile of an individual’s cognitive and learning styles—is proposed. Accommodation of such cognitive preferences can greatly facilitate knowledge management in the geographically dispersed and collaborative digital environment. Use of the CCI is proposed for cognitively labeled Latent Dirichlet Allocation (CLLDA), a novel method for automatically labeling and clustering knowledge that does not rely solely on probabilistic methods, but rather on a fusion of machine learning algorithms and the cognitive identities of the associated individuals interacting in a digitally mediated environment. Advantages include: a greater perspicuity of dynamic and meaningful cognitive rules leading to greater tagging accuracy and a higher content portability at the sentence, document, and corpus level with respect to digital communication.
Due to continuously intensifying human usage of the marine environment worldwide ranging cetaceans face an increasing number of threats. Besides whaling, overfishing and by-catch, new technical developments increase the water and noise pollution, which can negatively affect marine species. Cetaceans are especially prone to these influences, being at the top of the food chain and therefore accumulating toxins and contaminants. Furthermore, they are extremely noise sensitive due to their highly developed hearing sense and echolocation ability. As a result, several cetacean species were brought to extinction during the last century or are now classified as critically endangered. This work focuses on two odontocetes. It applies and compares different molecular methods for inference of population status and adaptation, with implications for conservation. The worldwide distributed sperm whale (Physeter macrocephalus) shows a matrilineal population structure with predominant male dispersal. A recently stranded group of male sperm whales provided a unique opportunity to investigate male grouping for the first time. Based on the mitochondrial control region, I was able to infer that male bachelor groups comprise multiple matrilines, hence derive from different social groups, and that they represent the genetic variability of the entire North Atlantic. The harbor porpoise (Phocoena phocoena) occurs only in the northern hemisphere. By being small and occurring mostly in coastal habitats it is especially prone to human disturbance. Since some subspecies and subpopulations are critically endangered, it is important to generate and provide genetic markers with high resolution to facilitate population assignment and subsequent protection measurements. Here, I provide the first harbour porpoise whole genome, in high quality and including a draft annotation. Using it for mapping ddRAD seq data, I identify genome wide SNPs and, together with a fragment of the mitochondrial control region, inferred the population structure of its North Atlantic distribution range. The Belt Sea harbors a distinct subpopulation oppose to the North Atlantic, with a transition zone in the Kattegat. Within the North Atlantic I could detect subtle genetic differentiation between western (Canada-Iceland) and eastern (North Sea) regions, with support for a German North Sea breading ground around the Isle of Sylt. Further, I was able to detect six outlier loci which show isolation by distance across the investigated sampling areas. In employing different markers, I could show that single maker systems as well as genome wide data can unravel new information about population affinities of odontocetes. Genome wide data can facilitate investigation of adaptations and evolutionary history of the species and its populations. Moreover, they facilitate population genetic investigations, providing a high resolution, and hence allowing for detection of subtle population structuring especially important for highly mobile cetaceans.
This thesis investigates how the permafrost microbiota responds to global warming. In detail, the constraints behind methane production in thawing permafrost were linked to methanogenic activity, abundance and composition. Furthermore, this thesis offers new insights into microbial adaptions to the changing environmental conditions during global warming. This was assesed by investigating the potential ecological relevant functions encoded by plasmid DNA within the permafrost microbiota. Permafrost of both interglacial and glacial origin spanning the Holocene to the late Pleistocene, including Eemian, were studied during long-term thaw incubations. Furthermore, several permafrost cores of different stratigraphy, soil type and vegetation cover were used to target the main constraints behind methane production during short-term thaw simulations. Short- and long-term incubations simulating thaw with and without the addition of substrate were combined with activity measurements, amplicon and metagenomic sequencing of permanently frozen and seasonally thawed active layer. Combined, it allowed to address the following questions. i) What constraints methane production when permafrost thaws and how is this linked to methanogenic activity, abundance and composition? ii) How does the methanogenic community composition change during long-term thawing conditions? iii) Which potential ecological relevant functions are encoded by plasmid DNA in active layer soils?
The major outcomes of this thesis are as follows. i) Methane production from permafrost after long-term thaw simulation was found to be constrained mainly by the abundance of methanogens and the archaeal community composition. Deposits formed during periods of warmer temperatures and increased precipitation, (here represented by deposits from the Late Pleistocene of both interstadial and interglacial periods) were found to respond strongest to thawing conditions and to contain an archaeal community dominated by methanogenic archaea (40% and 100% of all detected archaea). Methanogenic population size and carbon density were identified as main predictors for potential methane production in thawing permafrost in short-term incubations when substrate was sufficiently available.
ii) Besides determining the methanogenic activity after long-term thaw, the paleoenvironmental conditions were also found to influence the response of the methanogenic community composition. Substantial shifts within methanogenic community structure and a drop in diversity were observed in deposits formed during warmer periods, but not in deposits from stadials, when colder and drier conditions occurred. Overall, a shift towards a dominance of hydrogenotrophic methanogens was observed in all samples, except for the oldest interglacial deposits from the Eemian, which displayed a potential dominance of acetoclastic methanogens. The Eemian, which is discussed to serve as an analogue to current climate conditions, contained highly active methanogenic communities. However, all potential limitation of methane production after permafrost thaw, it means methanogenic community structure, methanogenic population size, and substrate pool might be overcome after permafrost had thawed on the long-term. iii) Enrichments with soil from the seasonally thawed active layer revealed that its plasmid DNA (‘metaplasmidome’) carries stress-response genes. In particular it encoded antibiotic resistance genes, heavy metal resistance genes, cold shock proteins and genes encoding UV-protection. Those are functions that are directly involved in the adaptation of microbial communities to stresses in polar environments. It was further found that metaplasmidomes from the Siberian active layer originate mainly from Gammaproteobacteria. By applying enrichment cultures followed by plasmid DNA extraction it was possible to obtain a higher average contigs length and significantly higher recovery of plasmid sequences than from extracting plasmid sequences from metagenomes. The approach of analyzing ‘metaplasmidomes’ established in this thesis is therefore suitable for studying the ecological role of plasmids in polar environments in general.
This thesis emphasizes that including microbial community dynamics have the potential to improve permafrost-carbon projections. Microbially mediated methane release from permafrost environments may significantly impact future climate change. This thesis identified drivers of methanogenic composition, abundance and activity in thawing permafrost landscapes. Finally, this thesis underlines the importance to study how the current warming Arctic affects microbial communities in order to gain more insight into microbial response and adaptation strategies.
Philosophische Tugenden
(2020)
Worin besteht gutes Philosophieren? Und weshalb ist gerade John Stuart Mill ein außergewöhnlich guter Philosoph? Joachim Toenges-Hinn verbindet in diesem Band die metaphilosophische Suche danach, was gute Philosophie ausmacht, mit einer historischen Betrachtung des Philosophen John Stuart Mill. Dabei fungiert Mill zugleich als Urheber von und Verkörperung des Strebens nach zwei philosophischen Tugenden, die Toenges-Hinn aus Mills philosophischem Werk ableitet und anschließend systematisch verteidigt. Diese als „Bentham-Ideal“ und „Coleridge-Ideal“ bezeichneten Tugenden stehen dabei ebenso im Fokus seiner Untersuchung wie die Bedeutung von Lebensexperimenten für philosophische Biografien.
Ein Ergebnis der interkulturellen Beziehungen in Südostasien sind die immer noch existierenden portugiesisch-basierten Kreolsprachen Papia Kristang und Macaísta, die zu Muttersprachen von Generationen von Menschen in Malakka und Macau geworden sind. Welche Faktoren bewirken den Sprachwandel dieser Idiome, und wie ist dieser erkennbar? Dieser Band beschäftigt sich nicht nur mit der Sprachdynamik der portugiesisch-basierten Kreolsprachen Südostasiens, sondern auch mit anderen wesentlichen Fragestellungen der Variationslinguistik. Als Basis dienen die Ergebnisse einer empirischen Datenerhebung, die insbesondere die Veränderungen im Sprachgebrauch dokumentieren. Darüber hinaus stellt der Autor neue Resultate hinsichtlich der Sprachidentifikationen vor, die nicht nur für die Kreolistik von Bedeutung sind, sondern auch fachübergreifend für das Interesse der allgemeinen Sprachwissenschaft.
This book endeavours to understand the seemingly direct link between utopianism and the USA, discussing novels that have never been brought together in this combination before, even though they all revolve around intentional communities: Imlay’s The Emigrants (1793), Hawthorne’s The Blithedale Romance (1852), Howland’s Papas Own Girl (1874), Griggs’s Imperium in Imperio (1899), and Du Bois’s The Quest of the Silver Fleece (1911). They relate nation and utopia not by describing perfect societies, but by writing about attempts to immediately live radically different lives. Signposting the respective communal history, the readings provide a literary perspective to communal studies, and add to a deeply necessary historicization for strictly literary approaches to US utopianism, and for studies that focus on Pilgrims/Puritans/Founding Fathers as utopian practitioners. This book therefore highlights how the authors evaluated the USA’s utopian potential and traces the nineteenth-century development of the utopian imagination from various perspectives.
The development of methods such as super-resolution microscopy (Nobel prize in Chemistry, 2014) and multi-scale computer modelling (Nobel prize in Chemistry, 2013) have provided scientists with powerful tools to study microscopic systems. Sub-micron particles or even fluorescently labelled single molecules can now be tracked for long times in a variety of systems such as living cells, biological membranes, colloidal solutions etc. at spatial and temporal resolutions previously inaccessible. Parallel to such single-particle tracking experiments, super-computing techniques enable simulations of large atomistic or coarse-grained systems such as biologically relevant membranes or proteins from picoseconds to seconds, generating large volume of data. These have led to an unprecedented rise in the number of reported cases of anomalous diffusion wherein the characteristic features of Brownian motion—namely linear growth of the mean squared displacement with time and the Gaussian form of the probability density function (PDF) to find a particle at a given position at some fixed time—are routinely violated. This presents a big challenge in identifying the underlying stochastic process and also estimating the corresponding parameters of the process to completely describe the observed behaviour. Finding the correct physical mechanism which leads to the observed dynamics is of paramount importance, for example, to understand the first-arrival time of transcription factors which govern gene regulation, or the survival probability of a pathogen in a biological cell post drug administration. Statistical Physics provides useful methods that can be applied to extract such vital information. This cumulative dissertation, based on five publications, focuses on the development, implementation and application of such tools with special emphasis on Bayesian inference and large deviation theory. Together with the implementation of Bayesian model comparison and parameter estimation methods for models of diffusion, complementary tools are developed based on different observables and large deviation theory to classify stochastic processes and gather pivotal information. Bayesian analysis of the data of micron-sized particles traced in mucin hydrogels at different pH conditions unveiled several interesting features and we gained insights into, for example, how in going from basic to acidic pH, the hydrogel becomes more heterogeneous and phase separation can set in, leading to observed non-ergodicity (non-equivalence of time and ensemble averages) and non-Gaussian PDF. With large deviation theory based analysis we could detect, for instance, non-Gaussianity in seeming Brownian diffusion of beads in aqueous solution, anisotropic motion of the beads in mucin at neutral pH conditions, and short-time correlations in climate data. Thus through the application of the developed methods to biological and meteorological datasets crucial information is garnered about the underlying stochastic processes and significant insights are obtained in understanding the physical nature of these systems.
The steadily rising number of investor-State arbitration proceedings within the EU has triggered an extensive backlash and an increased questioning of the international investment law regime by different Member States as well as the EU Commission. This has resulted in the EU's assertion of control over the intra-EU investment regime by promoting the termination of bilateral intra-EU investment treaties (intra-EU BITs) and by opposing the jurisdiction of arbitral tribunals in intra-EU investor-State arbitration proceedings. Against the backdrop of the landmark Achmea decision of the European Court of Justice, the book offers an in depth analysis of the interplay of international investment law and the law of the European Union with regard to intra-EU investments, i.e. investments undertaken by an investor from one EU Member State within the territory of another EU Member State. It specifically analyses the conflict between the two investment protection regimes applicable within the EU with a particular emphasis on the compatibility of the international legal instruments with the law of the European Union. The book thereby addresses the more general question of the relationship between EU law and international law and offers a conceptual framework of intra-European investment protection based on the analysis of all intra-EU BITs, the Energy Charter Treaty and EU law, as well as the arbitral practice in over 180 intra-EU investor-State arbitration proceedings. Finally, the book develops possible solutions to reconcile the international legal standards of protection with the regionalized transnational law of the European Union
Nach lavierenden obiter dicta entspricht die Steueranspruchstheorie wieder der gefestigten Rechtsprechung des 1. Strafsenates des BGH (zuletzt: BGH, Beschl. v. 1.4.2020 – 1 StR 5/20, BeckRS 2020, 23245). Für den prozessualen Nachweis des Steuerhinterziehungsvorsatzes ist damit erforderlich, dass der Steuerpflichtige auch in rechtlicher Hinsicht den verletzten Steueranspruch kannte. Die vorliegende Rechtsprechungsanalyse zum straf- und finanzgerichtlichen Vorsatznachweis bei § 370 AO zeigt, dass die Judikatur mit diesem Konzept besser umgeht als vielfach unterstellt.
Insoweit wird herausgearbeitet, dass die Rechtsprechung mit einem hinreichend etablierten Kanon an Indizien operiert, welche berechtigterweise den Schluss auf vorsätzliches Handeln zulassen. Zugleich kommt die Untersuchung zu dem Ergebnis, dass die Rechtsprechung ebenfalls konsistent entlastende Umstände würdigt und bei entsprechender Indizienlage einen vorsatzausschließenden Irrtum feststellt. Als weiteres Ergebnis liefert die Untersuchung zugleich eine Leitlinie für den Tatrichter bei der Vorsatzfeststellung im Steuerstrafverfahren.
Die Trennung von Werbung und Programm gilt als »Magna Charta« des Medienrechts. In der Medienpraxis scheinen jedoch andere Spielregeln zu herrschen: Werbung soll dort so unauffällig wie möglich in das redaktionelle Programm eingebaut werden, um mit dem potenziellen Käufer erfolgreich zu kommunizieren. Immer neue programmintegrierte Werbeformen entstehen, die Programme darauf ausrichten, Markenprodukte in Szene zu setzen. Dieser Widerspruch zwischen Recht und Praxis bildet den Hintergrund dieser Arbeit. Im Schwerpunkt wird der Rechtsbegriff der Schleichwerbung im nationalen Medienrecht untersucht. Für die Bestimmung der verbotenen programmintegrierten Werbeform im Fernsehen und Internet stellt der Rundfunkstaatsvertrag die entscheidende Rechtsgrundlage dar. Insbesondere spielt die Schleichwerbung im Zusammenhang mit dem Influencer-Marketing eine große Rolle und daher klärt die Arbeit, was Werbebetreibende in sozialen Medien beachten müssen. Ferner werden die Aktualität und Angemessenheit der heutigen Regeln analysiert. Die Arbeit wurde ausgezeichnet mit dem Wolf-Rüdiger-Bub-Preis des Vereins der Freunde und Förderer der Juristischen Fakultät der Universität Potsdam.
The transfer of particulate organic carbon from continents to the ocean is an important component of the global carbon cycle. Transfer to and burial of photosynthetically fixed biospheric organic carbon in marine sediments can effectively sequester atmospheric carbon dioxide over geological timescales. The exhumation and erosion of fossil organic carbon contained in sedimentary rocks, i.e. petrogenic carbon, can result in remineralization, releasing carbon to the atmosphere. In contrast, eroded petrogenic organic carbon that gets transferred back to the ocean and reburied does not affect atmospheric carbon content.
Mountain ranges play a key role in this transfer since they can source vast amounts of sediment including particulate organic carbon. Globally, the export of both, biospheric and petrogenic organic carbon has been linked to sediment export. Additionally, short transfer times from mountains to the ocean and high sediment concentrations have been shown to increase the likelihood of organic carbon burial. While the importance of mountain ranges in the organic carbon cycle is now widely recognized, the processes acting within mountain ranges to influence the storage, cycling and mobilization of organic carbon, as well as carbon fluxes from mountain ranges remain poorly constrained.
In this thesis, I employ different methods to assess the nature and fate of particulate organic carbon in mountain belts, ranging from the molecular to regional landscape scale. These studies are located along the Trans-Himalayan Kali Gandaki River in Central Nepal. This river traverses all major geological and climatic zones of the Himalaya, from the dry northern Tibetan plateau to the high-relief, monsoon dominated steep High Himalaya and the lower relief and abundant vegetation of the Lesser Himalayan region.
First, I document how biospheric organic matter has accumulated during the Holocene in the headwaters of the Kali Gandaki River valley, by combining compound specific isotope measurements with different dating methods and grain size data, and investigate the stability of this organic carbon reservoir on millennial timescales. I show, that around 1.6 ka an eco-geomorphic tipping point occurred leading to a destabilization of the landscape resulting in today’s high erosion rates and the excavation of the aged organic carbon reservoir. This study highlights the climatic and geomorphic controls on biospheric organic carbon storage and release from mountain ranges.
Second, I systematically investigate the spatial variation of particulate organic carbon fluxes across the Himalaya along the Kali Gandaki River, using bulk stable and radioactive isotopes combined with a new Bayesian modeling approach. The detailed dataset allows the distinction of aged and modern biospheric organic carbon as well as petrogenic organic carbon across the Himalayan mountain range and the investigation of the role of climatic and geomorphic factors in their riverine export. The data suggest a decoupling of the particulate organic carbon from the sediment yield along the Kali Gandaki River, partially driven by climatic and geomorphic processes. In contrast to the suspended sediment, a large part of the particulate organic carbon exported by the river originates from the Tibetan part of the catchment and is dominated by petrogenic organic carbon derived from Jurassic shales with only minor contributions of modern and aged biospheric organic carbon. These findings emphasize the importance of organic carbon source distribution and erosion mechanisms in determining the organic carbon export from mountain ranges.
In a third step, I explore the potential of ultra-high resolution mass spectrometry for particulate organic carbon transport studies. I have generated a novel and unprecedented high-resolution molecular dataset, which contains up to 103 molecular formulas of the lipid fraction of particulate organic matter for modern and aged biospheric carbon, petrogenic organic carbon and river sediments. First, I test if this dataset can be used to better resolve different organic carbon sources and to identify new geochemical tracers. Using multivariate statistics, I identify up to 10² characteristic molecular formulas for the major organic carbon sources in the upper part of the Kali Gandaki catchment, and trace their transfer from the surrounding landscape into the river sediment. Second, I test the potential of the molecular dataset to trace molecular transformations along source-to-sink pathways. I identify changes in molecular metrics derived from the dataset, which are characteristic of transformation processes during incorporation of litter into soil, the aging of soil material, and the mobilization of the organic carbon into the river. These two studies demonstrate that high-resolution molecular datasets open a promising analytical window on particulate organic carbon and can provide novel insights into the composition, sourcing and transformation of riverine particulate organic carbon.
Collectively, these studies advance our understanding of the processes contributing to the storage and mobilization of organic carbon in the Central Himalaya, the mountain belt that dominates global erosional fluxes. They do so by identifying the major sources of particulate organic carbon to the Trans-Himalayan Kali Gandaki River, by elucidating their sensitivity to climate and geomorphic processes, and by identifying some of the transformations of this material on the molecular scale. As a result, the thesis demonstrates that the amount and composition of organic carbon routed from mountain belts is a function of the dynamic interactions of geologic, biologic, geomorphic and climatic processes within the mountain belt. This understanding will ultimately help in answering whether the build-up and erosion of mountain ranges over geological time represents a net carbon source or sink to the atmosphere. Beyond this, the thesis contributes to our technical ability to characterize organic matter and attribute it to sources by scoping the potential of high-end molecular analysis.
Grenzen des Organisierbaren
(2020)
With populations growing worldwide and climate change threatening food production there is an urgent need to find ways to ensure food security. Increasing carbon fixation rate in plants is a promising approach to boost crop yields. The carbon-fixing enzyme Rubisco catalyzes, beside the carboxylation reaction, also an oxygenation reaction that generates glycolate-2P, which needs to be recycled via a metabolic route termed photorespiration. Photorespiration dissipates energy and most importantly releases previously fixed CO2, thus significantly lowering carbon fixation rate and yield. Engineering plants to omit photorespiratory CO2 release is the goal of the FutureAgriculture consortium and this thesis is part of this collaboration. The consortium aims to establish alternative glycolate-2P recycling routes that do not release CO2. Ultimately, they are expected to increase carbon fixation rates and crop yields. Natural and novel reactions, which require enzyme engineering, were considered in the pathway design process. Here I describe the engineering of two pathways, the arabinose-5P and the erythrulose shunt. They were designed to recycle glycolate-2P via glycolaldehyde into a sugar phosphate and thereby reassimilate glycolate-2P to the Calvin cycle. I used Escherichia coli gene deletion strains to validate and characterize the activity of both synthetic shunts. The strains’ auxotrophies can be alleviated by the activity of the synthetic route, thus providing a direct way to select for pathway activity. I introduced all pathway components to these dedicated selection strains and discovered inhibitions, limitations and metabolic cross talk interfering with pathway activity. After resolving these issues, I was able to show the in vivo activity of all pathway components and combine them into functional modules.. Specifically, I demonstrate the activity of a new-to-nature module of glycolate reduction to glycolaldehyde. Also, I successfully show a new glycolaldehyde assimilation route via arabinose-5P to ribulose-5P. In addition, all necessary enzymes for glycolaldehyde assimilation via L-erythrulose were shown to be active and an L-threitol assimilation route via L-erythrulose was established in E. coli. On their own, these findings demonstrate the power of using an easily engineerable microbe to test novel pathways; combined, they will form the basis for implementing photorespiration bypasses in plants.
Das Ziel der vorliegenden Dissertation war es herauszuarbeiten, ob Nachhaltigkeitsbewusstsein den Konsum von Luxusgütern beeinflusst und ob verschiedene Moderatoren einen Einfluss auf diesen Zusammenhang ausüben. Das Nachhaltigkeitsbewusstsein wurde dabei basierend auf dem von Balderjahn et al. (2013) entwickelten Consciousness-for-sustainable-consumption-Modell durch die ökologische, soziale und die ökonomische Nachhaltigkeit sowie ergänzend durch das Tierschutzbewusstsein und Bewusstsein für lokale Produktion repräsentiert. Als Moderatoren dienten das Streben nach sozialer Anerkennung und Prestige, Materialismus, Hedonismus und Traditionsbewusstsein. Für die Aufdeckung möglicher Zusammenhänge zwischen den verschiedenen Dimensionen der Nachhaltigkeit und Luxuskonsum wurde eine Prädiktorenanalyse durchgeführt. Moderatorenanalysen offenbarten zusätzlich, ob ein Einfluss der verschiedenen Moderatoren auf die einzelnen Zusammenhänge vorlag. Die Untersuchung zeigte, dass jeweils das Umweltbewusstsein, das Bewusstsein für genügsamen Konsum sowie das Bewusstsein für schuldenfreien Konsum als Teil der ökonomischen Nachhaltigkeit und das Tierschutzbewusstsein einen Einfluss auf den Luxuskonsum ausüben. Darüber hinaus konnten insgesamt sieben Einflüsse durch die verschiedenen Moderatorvariablen auf die unterschiedlichen Zusammenhänge zwischen den Nachhaltigkeitsdimensionen und Luxuskonsum aufgedeckt werden.
Today’s focus on the 1930s as a time of radical politics paving the way for the apocalypse of the Second World War ignores the complexity of the decade’s cultural responses, especially those by British women writers who highlighted gender issues within their contemporary political climate. The decade’s literature is often understood to capture the political unrest, either narrating people’s chaotic movement or their paralysed shock. This book argues that 1930s novels collapse the distinction between movement and standstill and calls this phenomenon Dynamic Stasis. This Dynamic Stasis thematically and structurally informs the novels of Nancy Mitford, Stevie Smith, Rosamond Lehmann and Jean Rhys. By disrupting the oft-repeated cliché of the 1930s as the age of political extremes, gender politics and negotiations of femininity can emerge from the discursive periphery. This book therefore corrects a persistent gender blind spot, which opens up a (re)consideration of authors that have been overlooked in literary criticism of 1930s to this day.
Advanced hybrid materials are recognized as one of the most significant enablers for new technologies, which holds true especially on the quest for sustainable energy sources and energy production schemes (e.g., semiconductor based photocatalytic materials). Usually, a single component is far from meeting all the demands needed for these advanced applications. Hybrid materials are composed of at least two components commonly an inorganic and an organic material on the molecular level, which feature novel properties exceeding the sum of the individual parts and might be the milestones of next-generation applications. This dissertation aims to provide novel combinations of the metal-free semiconductor graphitic carbon nitride (g-C3N4) with polymers to obtain materials with advanced properties and applications. Visible light constitutes the core of the present work as it is the only energy source utilized either in synthesis or in the application process. In the area of applications by combination of g-C3N4 and polymers, two different hybrids were thoroughly elucidated, i.e.. their design and construction as well as potential application in photocatalysis. Novel soft 3D liquid objects were formed via charge-interaction driven interfacial jamming between polyelectrolytes in aqueous environment and colloidal dispersions of g-C3N4 in edible sunflower oil. As such, stable liquid objects could be molded into specific shapes and utilized for photodegradation of organic dyes in water. Furthermore, the grafting of polymers onto g-C3N4 was investigated. Allyl-end functionalized polymers were grafted onto g-C3N4 by a photoinitiated process to yield g-C3N4 with versatile and improved properties, e.g. advanced dispersibility enabling processing via spin coating. As g-C3N4 produces radicals under visible light irradiation, which is of significant interest for polymer science, g-C3N4 containing polymer latex and macrogel beads (MGB) were synthesized by emulsion photopolymerization and inverse suspension photopolymerization, respectively. A well-controlled emulsion photopolymerization process via g-C3N4 initiation was designed, which features synthesis of well-defined and cross-linked polymer particles. Furthermore, the polymerization process was investigated thoroughly, indicating an ad-layer polymerization in early stages of the process. The utilization of functionalized g-C3N4 allowed the polymerization of various monomer types. Moreover, g-C3N4 was utilized as photoinitiator in hydrogel MGB formation. The formed MGB properties could be tailored via process design, e.g. stirring rate, cross-linker content and g-C3N4 content. Finally, MGBs were introduced as photocatalyst for waste water remediation, i.e. the degradation of Rhodamine B in aqueous solution was studied. The present thesis therefore builds a bridge between g-C3N4 and polymers and provides strategies for hybrid material formation. Furthermore, several potential applications are revealed with significant implications for photocatalysis, polymerization processes and polymer materials.
Bilder des Glaubens
(2020)
Medien prägen maßgeblich das öffentliche Bild von Religion in der modernen Gesellschaft, weshalb die Kirchen frühzeitig mediale Wege der Verkündigung suchten. Das Fernsehen als bedeutendstes Massenmedium in der zweiten Hälfte des 20. Jahrhunderts spielte dabei eine Schlüsselrolle. Von den Kirchen produzierte Unterhaltungsserien erreichten große Reichweiten, gleichzeitig entwickelte sich das bundesdeutsche Fernsehen zu einem Experimentierfeld für neue Praktiken der Religionsausübung. Alternative Glaubensformen gewannen an Aufmerksamkeit, etwa nichtchristliche Weltreligionen wie der Islam, Gläubige am Rande der Kirchen wie die Evangelikalen oder als »Sekten« geschmähte Gruppen wie die Zeugen Jehovas, aber auch spirituelle Phänomene wie Wahrsagerei, Okkultismus und »New Age«. Ronald Funke analysiert die zwischen den 1950er und 1980er Jahren im Fernsehen gezeigten Bilder des Glaubens in der Bundesrepublik und verdeutlicht, wie deren Inhalte durch enge Zusammenarbeit, aber auch durch Konflikte ausgehandelt wurden.
Grenzen des Organiesierbaren
(2020)
Interessiert man sich für den gesellschaftlichen Einfluss der Organisationssoziologie auf die Praxis des Organisierens, so muss der Befund ernüchtern. Stärker als auf organisationssoziologische Wissensbestände wird in Unternehmen oder Verwaltungen auf aktuelle Managementtrends rekurriert. Man könnte diesen Befund beklagen und als fehlerhafte Rezeption der Praxis beiseitelegen. Alternativ ließe sich aber auch diskutieren, welchen Beitrag die Disziplin selbst zu dieser Rezeption leistet. Mit einer solchen Diskussion begibt man sich fast unweigerlich auf einen schwierigen Pfad. Zum einen kann die Soziologie gerade dann, wenn sie ihren Blick auf die Erforschung von Unternehmen oder Verwaltungen richtet, nicht die von der Praxis erwarteten positiven Antworten liefern. Gerade die Organisationssoziologie begibt sich zum anderen jedoch in direkte Konkurrenz zu Nachbardisziplinen wie die Betriebswirtschaftslehre oder die Organisationspsychologie, die die Rezeptionsfähigkeit ihrer Wissensbestände im Praxisfeld in den letzten Jahren unter Beweis gestellt haben. Die Erwartungen an die Umsetzbarkeit wissenschaftlicher Erkenntnisse in der Praxis sind dadurch gestiegen. Eine Soziologie, die ihre Erkenntniskraft in der kritischen Distanz sieht, mag das skeptisch stimmen. Es gilt daher, die Frage zu beantworten, wie die Praxisrelevanz einer Wissenschaft des zweiten Blicks auf Organisationen konkret aussehen kann. Diesem Vorhaben widmet sich das vorgelegte Promotionsprojekt. Die in der kumulativen Dissertation versammelten Beiträge verstehen sich allesamt als Erkundungen und Erprobungen der Praxisrelevanz der Organisationssoziologie anhand aktueller Managementfragen in Unternehmen. Die These lautet dabei, dass sich diese Praxisrelevanz nur als Kritik entfalten kann. Eine solche Kritik kann dabei zwei grundsätzliche Formen annehmen: Als Strukturkritik bezieht sie sich auf konkrete Organisationen, deren spezifische Eigenlogiken und strukturelle Verstrickungen. Sie beschreibt dabei für den Einzelfall Funktionen und Folgen von Erwartungsstrukturen, die sich dann z. B. fallvergleichend generalisieren oder typisieren lassen. Organisationssoziologische Strukturkritik kann sich damit sowohl als vergleichender, praxissensibler Forschungsansatz realisieren, als auch die Grundlage einer soziologisch orientierten Beratung bilden. Als Schematakritik richtet sie sich gegen verkürzte Vorstellungen des Organisierens, die sich etwa in Managementmoden finden lassen. Dem Kumulus zugrunde liegen fünf Beiträge, die konkrete Ausprägungen beider Kritikformen ausloten. Der erste Beitrag „Datafizierung und Organisation“ zeigt, wie Schematakritik an Nachbardisziplinen aussehen kann, indem er Organisation als blinden Fleck der Digitalisierungsforschung diskutiert und Anschlussstellen für interdisziplinäre Forschung ausweist. Daher liefert der Beitrag einen systematischen Zugang zu organisationalen Implikationen der Digitalisierung. Neben der Anreicherung der Digitalisierungsforschung kann die entwickelte Argumentation auch für die Praxis Erkenntniskraft haben, indem z. B. problematisiert wird, dass im Managementdiskurs um Digitalisierung überzogene Rationalisierungserwartungen herrschen oder durch digitale Infrastrukturen entstehende Informalitäten systematisch ausgeblendet werden Der zweite Beitrag „Führung als erfolgreiche Einflussnahme in kritischen Momenten“ legt eine Umdeutung des populären Managementbegriffs Führung durch Schematakritik vor. Damit trägt er in mehrfacher Hinsicht zu einer praxisrelevanten Neubestimmung von Führung bei. Für Führungskräfte ermöglicht er beispielsweise die Einsicht, dass sie ihre Führungsaufgaben auf kritische Momente konzentrieren können und postuliert die Abkehr vom heroischen Bild des dauerhaft Führenden. Diese Umdeutung kann auch für Führungskräfte in Organisationen entlastend sein, weist sie doch auf den Zusammenhang zwischen der organisationalen Verfasstheit und Führungschancen hin und eröffnet damit Gestaltungschancen jenseits der Führungskräfte- und Personalentwicklung. Für die Organisationsforschung liefert der Beitrag einen theoretisch integrierten Führungsbegriff, der Führung sowohl organisational als auch situativ bestimmt. Er steht somit exemplarisch für eine organisationssoziologische Schematakritik, die etablierte Managementbegriffe neu deutet. Der dritte Beitrag kritisiert mit dem Konzept der transformationalen Führung eine Managementmode und zeigt auf, wie das darin enthaltene Führungsmodell durch die Bildung moralischer Kategorien Organisationsprobleme auf Organisationsmitglieder (hier: Führungskräfte) verschiebt. Es wird einerseits eine organisationssoziologische Kritik am populären Managementkonzept der transformationalen Führung vorgelegt. Andererseits verdeutlicht der Beitrag anhand systemtheoretischer Konzepte wie elementarer Verhaltensweisen, Moral oder Rollentrennung exemplarisch, dass organisationssoziologisches Denken den Managementdiskurs bereichern kann, indem es Verkürzungen und Simplifizierungen aufdeckt und alternative Analyse- und Gestaltungsansätze bereitstellt. Dafür lässt sich auch im Praxisdiskurs Gehör finden, weil man annehmen darf, dass mit den Heilsversprechen von Kompaktlösungen auch Enttäuschungen einhergehen, für die die Organisationssoziologie Erklärungen liefern kann. Die Möglichkeiten und Grenzen von Strukturkritik werden in den letzten beiden Beiträgen diskutiert. Das Potenzial von Strukturkritik für die soziologisch orientierte Beratung von Organisationen exploriert der Beitrag „Die schwierige Liaison von Organisationssoziologie und Praxisbezug am Beispiel der Beratung“. Ausgehend vom Theorie-Praxis-Komplex wird eruiert, wie soziologischer Praxisbezug im Feld der Beratung aussehen kann. Dafür systematisiert der Beitrag organisationssoziologische Ansätze von Beratung und zeigt auf, wie ein genuin soziologischer Beratungsansatz aussehen könnte. Der letzte Beitrag stellt Grundzüge einer Methodologie strukturkritischer Forschung vor und illustriert diese an einem durchgeführten Forschungsprojekt zu Managementmoden. Anhand der Forschung in einem Produktionsbetrieb wird gezeigt, wie strukturkritische Forschung konkret aussehen kann. Solch strukturkritische Forschung steht im Forschungsprozess vor drei Herausforderungen: dem qualitativ hochwertigen Feldzugang, der Entwicklung einer für Forschung und Praxis instruktiven Fragestellung und der Rückspiegelung der Ergebnisse in das Feld. Der Beitrag stellt Grundzüge einer Methodologie strukturkritischer Organisationsforschung vor, die sich sachlich, zeitlich und sozial entlang der drei beschriebenen Momente des Feldzugangs, der Ausgangsfragestellung und der Rückspiegelung der Ergebnisse spezifizieren lassen.
TrainTrap
(2020)
Die Verweigerung des Militärdienstes und seine Folgen sind angesichts andauernder bewaffneter Konflikte immer häufiger Gegenstand von Asylanträgen. Die Autorin untersucht die Voraussetzungen für die Flüchtlingsanerkennung von Wehrdienstverweigerern anhand verschiedener Fallgruppen und unter Einbeziehung zahlreicher Entscheidungen von angloamerikanischen, europäischen und deutschen Gerichten. Dabei widmet sie sich dem Spannungsfeld zwischen dem Wehrdienst als Grundpflicht und dem Recht auf Kriegsdienstverweigerung aus Gewissensgründen. Zudem beleuchtet sie das Verhältnis des Flüchtlingsrechts zum humanitären Völkerrecht und Völkerstrafrecht, bettet also das Flüchtlingsrecht in andere Teilbereiche des Völkerrechts ein.
Sie senden den Wandel
(2020)
Altbekannt ist, welch wichtige Rolle Medien bei der Konsolidierung oder aber auch bei der Transformation einer Gesellschaft spielen. Was aber geschieht, wenn Medien von unten aus agieren und dies in großer Zahl geschieht, unter Einbindung vieler gesellschaftlicher Akteure sowie gegenüber einem umfassenden Publikum? In Argentinien hat sich eine faszinierende Radiolandschaft gebildet, die kollektiv, partizipativ und progressiv arbeitet: Die Community-Radios. Viviana Uriona nimmt uns mit auf eine ethnografische Reise durch die Geschichte dieser Radios, analysiert ihre Arbeitsweise und sucht nach den Gründen ihres Erfolges. Am Ende der Lektüre bleibt eine Frage nicht mehr offen: Könnte hierzulande in gleicher Weise gelingen, was dort geschah?
Lehrkräftefortbildungen werden in der Forschung als vielversprechende Möglichkeit angesehen, Lehrkräfte dabei zu unterstützen, den an sie gestellten Anforderungen gerecht zu werden (Darling-Hammond, Hyler & Gardner, 2017). Über verschiedene Studien hinweg konnte hierbei gezeigt werden, dass die Teilnahme einer Lehrkraft an Fortbildungen positiv mit der Entwicklung ihrer Schüler*innen zusammenhängt (Kalinowski, Egert, Gronostaj & Vock, 2020; Yoon, Duncan, Lee, Scarloss & Shapley, 2007). Während ein Teil der Forschung ihren Fokus auf die Wirksamkeit von Fortbildungsangeboten richtet, nehmen andere Untersuchungen stärker die Nutzung dieser Angebote in den Blick. Die vorliegende Arbeit knüpft an die bisherige Forschung zur Lehrkräftefortbildung an und versucht, Aspekte der Nutzung und des Angebots der Lehrkräftefortbildung in Deutschland im Rahmen des Comprehensive Lifelong Learning Participation Models stärker gemeinsam zu betrachten (Boeren, Nicaise & Baert, 2010). Hierbei handelt es sich um ein Mehrebenen-Modell zur Erklärung von Weiterbildungsverhalten, welches verschiedene Akteursgruppen (z.B. Fortbildungsteilnehmer*innen, Fortbildungsinstitute) auf der Nachfrage- und der Angebotsseite berücksichtigt und deren Interdependenz in den Blick nimmt. Vor diesem Hintergrund beschäftigt sich die vorliegende Arbeit in vier Teilstudien mit den Merkmalen der Fortbildungsteilnehmer*innen und des Fortbildungsangebots. Sie untersucht zudem die Prädiktoren für Fortbildungsbeteiligung von Lehrkräften auf der Nachfrage- und Angebotsseite. Studie 1 fokussiert zunächst die Nachfrageseite des Comprehensive Lifelong Learning Participation Models (Boeren et al., 2010) und betrachtet die in der Forschung wenig beachtete Gruppe der Nicht-Teilnehmer*innen. An Befunde der allgemeinen Weiterbildungsforschung anknüpfend, beschäftigt sich diese Teilstudie mit den Teilnahmebarrieren von Lehrkräften an Fortbildungen und untersucht, wie diese mit der Fortbildungsaktivität von Lehrkräften zusammenhängen. Die Beantwortung der Forschungsfragen basiert auf einer Sekundärdatenanalyse des IQB-Ländervergleichs 2012 (Pant et al., 2013), auf dessen Grundlage ein Gruppenvergleich von Teilnehmer*innen und Nicht-Teilnehmer*innen an Fortbildung sowie eine faktoranalytische Betrachtung der berichteten Teilnahmebarrieren durchgeführt wurde. Studie 2 greift die Frage auf, welche Lehrkräfte intensiv von Angeboten der Fortbildung Gebrauch machen. Ausgangspunkt der Arbeit ist die Beobachtung eines Matthäus-Effektes durch die allgemeine Weiterbildungsforschung. Demnach beteiligen sich insbesondere jene Personen stärker an beruflichen Lerngelegenheiten, die bereits vor der Maßnahme über günstige Ausgangsvoraussetzungen, etwa in Form eines höheren Kompetenzniveaus im Vergleich zu Personen, die nicht oder weniger an Angeboten der Fort- und Weiterbildung partizipieren, verfügen. In Anlehnung an diese Befunde diskutiert Teilstudie 2 verschiedene Aspekte der Qualität von Lehrkräften und geht anhand bivariater Zusammenhangsanalysen der Frage nach, welche Zusammenhänge zwischen der Voraussetzung der Lehrkraft und der Nutzung von Fortbildung bestehen. Dabei berücksichtigt die Studie das von Boeren et al. (2010) eingeführte Comprehensive Lifelong Learning Participation Model, indem sie die Befunde der Wirksamkeits- und Angebotsforschung aufgreift und differentielle Effekte in Abhängigkeit der Merkmale der Fortbildungen (fachlich vs. nicht-fachlich) in den Blick nimmt. Die durchgeführten Analysen beruhen auf einer Sekundärdatenanalyse des COACTIV-Forschungsprojekts (Kunter, Baumert & Blum, 2011). Auch in Studie 3 steht die Interaktion von Nachfrage- und Angebotsseite im Mittelpunkt. Während in Studie 2 jedoch konzeptionelle Merkmale der Fortbildung fokussiert wurden, liegt der Fokus in Studie 3 auf dem strukturellen Merkmal Zeit. Zeiten zum (beruflichen) Lernen werden hierbei zunächst auf Basis empirischer Befunde als Grundvoraussetzung für das Zustandekommen von Fortbildungsbeteiligung herausgearbeitet. Die Studie geht dann der Frage nach, welche zeitlichen Merkmale das Fortbildungsangebot für Lehrkräfte aufweist und wie diese Merkmale des Angebots im Zusammenhang mit der Nutzung durch Lehrkräfte stehen. Zur Beantwortung der Forschungsfragen werden eine Programmanalyse sowie polynomiale Regressionen durchgeführt. Die der Analyse zugrundeliegenden Daten beruhen hierbei auf den in der elektronischen Datenbank hinterlegten Fortbildungsangebotsdaten für das Land Brandenburg aus dem akademischen Jahr 2016/2017. Studie 4 fokussiert schließlich die Gruppe der Lehrerfortbildner*innen und somit die Angebotsseite des Comprehensive Lifelong Learning Participation Models (Boeren et al., 2010). In Anlehnung an theoretische Arbeiten zur professionellen Identität wird dabei der Frage nachgegangen, wie Lehrerfortbildner*innen ihre Aufgaben wahrnehmen und wie diese Wahrnehmung mit weiteren Aspekten ihrer professionellen Identität und der Gestaltung ihrer Fortbildungsveranstaltungen zusammenhängt. Hierzu wurden selbsterhobene Daten einer schriftlichen Befragung von Lehrerfortbildner*innen im Jahr 2019 zunächst faktoranalytisch betrachtet und anschließend mithilfe bivariater Zusammenhangsanalysen untersucht. Die zentralen Ergebnisse der vorliegenden Arbeit werden abschließend zusammengefasst diskutiert. Sie deuten insgesamt darauf hin, dass das derzeitige Fortbildungssystem in Deutschland nicht dazu geeignet erscheint, alle Lehrkräfte mit qualitativ hochwertigen Fortbildungen so zu erreichen, dass sie an ihren Schwächen arbeiten können. Die Befunde zeigen weiter, dass Fortbildner*innen eine mögliche Stellschraube für die Veränderung von Teilen des Fortbildungsangebots darstellen. Die Befunde bieten somit die Grundlage für zukünftige Forschungsarbeiten und mögliche Implikationen in der Fortbildungspraxis und Bildungspolitik.
Small moonlets or moons embedded in dense planetary rings create S-shaped density modulations called propellers if their masses are smaller than a certain threshold, alternatively they create a circumferential gap in the disk if the embedded body’s mass exceeds this threshold (Spahn and Sremčević, 2000). The gravitational perturber scatters the ring particles, depletes the disk’s density, and, thus, clears a gap, whereas counteracting viscous diffusion of the ring material has the tendency to close the created gap, thereby forming a propeller. Propeller objects were predicted by Spahn and Sremčević (2000) and Sremčević et al. (2002) and were later discovered by the Cassini space probe (Tiscareno et al., 2006, Sremčević et al., 2007, Tiscareno et al., 2008, and Tiscareno et al., 2010). The ring moons Pan and Daphnis are massive enough to maintain the circumferential Encke and Keeler gaps in Saturn’s A ring and were detected by Showalter (1991) and Porco (2005) in Voyager and Cassini images, respectively. In this thesis, a nonlinear axisymmetric diffusion model is developed to describe radial density profiles of circumferential gaps in planetary rings created by embedded moons (Grätz et al., 2018). The model accounts for the gravitational scattering of the ring particles by the embedded moon and for the counteracting viscous diffusion of the ring matter back into the gap. With test particle simulations it is shown that the scattering of the ring particles passing the moon is larger for small impact parameters than estimated by Goldreich and Tremaine (1980). This is especially significant for the modeling of the Keeler gap. The model is applied to the Encke and Keeler gaps with the aim to estimate the shear viscosity of the ring in their vicinities. In addition, the model is used to analyze whether tiny icy moons whose dimensions lie below Cassini’s resolution capabilities would be able to cause the poorly understood gap structure of the C ring and the Cassini Division. One of the most intriguing facets of Saturn’s rings are the extremely sharp edges of the Encke and Keeler gaps: UVIS-scans of their gap edges show that the optical depth drops from order unity to zero over a range of far less than 100 m, a spatial scale comparable to the ring’s vertical extent. This occurs despite the fact that the range over which a moon transfers angular momentum onto the ring material is much larger. Borderies et al. (1982, 1989) have shown that this striking feature is likely related to the local reversal of the usually outward-directed viscous transport of angular momentum in strongly perturbed regions. We have revised the Borderies et al. (1989) model using a granular flow model to define the shear and bulk viscosities, ν and ζ, in order to incorporate the angular momentum flux reversal effect into the axisymmetric diffusion model for circumferential gaps presented in this thesis (Grätz et al., 2019). The sharp Encke and Keeler gap edges are modeled and conclusions regarding the shear and bulk viscosities of the ring are discussed. Finally, we explore the question of whether the radial density profile of the central and outer A ring, recently measured by Tiscareno and Harris (2018) in the highest resolution to date, and in particular, the sharp outer A ring edge can be modeled consistently from the balance of gravitational scattering by several outer moons and the mass and momentum transport. To this aim, the developed model is extended to account for the inward drifts caused by multiple discrete and overlapping resonances with multiple outer satellites and is then used to hydrodynamically simulate the normalized surface mass density profile of the A ring. This section of the thesis is based on studies by Tajeddine et al. (2017a) who recently discussed the common misconception that the 7:6 resonance with Janus alone maintains the outer A ring edge, showing that the combined effort of several resonances with several outer moons is required to confine the A ring as observed by the Cassini spacecraft.
To meet the demands of a growing world population while reducing carbon dioxide (CO2) emissions, it is necessary to capture CO2 and convert it into value-added compounds. In recent years, metabolic engineering of microbes has gained strong momentum as a strategy for the production of valuable chemicals. As common microbial feedstocks like glucose directly compete with human consumption, the one carbon (C1) compound formate was suggested as an alternative feedstock. Formate can be easily produced by various means including electrochemical reduction of CO2 and could serve as a feedstock for microbial production, hence presenting a novel entry point for CO2 to the biosphere and a storage option for excess electricity. Compared to the gaseous molecule CO2, formate is a highly soluble compound that can be easily handled and stored. It can serve as a carbon and energy source for natural formatotrophs, but these microbes are difficult to cultivate and engineer. In this work, I present the results of several projects that aim to establish efficient formatotrophic growth of E. coli – which cannot naturally grow on formate – via synthetic formate assimilation pathways. In the first study, I establish a workflow for growth-coupled metabolic engineering of E. coli. I demonstrate this approach by presenting an engineering scheme for the PFL-threonine cycle, a synthetic pathway for anaerobic formate assimilation in E. coli. The described methods are intended to create a standardized toolbox for engineers that aim to establish novel metabolic routes in E. coli and related organisms. The second chapter presents a study on the catalytic efficiency of C1-oxidizing enzymes in vivo. As formatotrophic growth requires generation of both energy and biomass from formate, the engineered E. coli strains need to be equipped with a highly efficient formate dehydrogenase, which provides reduction equivalents and ATP for formate assimilation. I engineered a strain that cannot generate reducing power and energy for cellular growth, when fed on acetate. Under this condition, the strain depends on the introduction of an enzymatic system for NADH regeneration, which could further produce ATP via oxidative phosphorylation. I show that the strain presents a valuable testing platform for C1-oxidizing enzymes by testing different NAD-dependent formate and methanol dehydrogenases in the energy auxotroph strain. Using this platform, several candidate enzymes with high in vivo activity, were identified and characterized as potential energy-generating systems for synthetic formatotrophic or methylotrophic growth in E. coli. In the third chapter, I present the establishment of the serine threonine cycle (STC) – a synthetic formate assimilation pathway – in E. coli. In this pathway, formate is assimilated via formate tetrahydrofolate ligase (FtfL) from Methylobacterium extorquens (M. extorquens). The carbon from formate is attached to glycine to produce serine, which is converted into pyruvate entering central metabolism. Via the natural threonine synthesis and cleavage route, glycine is regenerated and acetyl-CoA is produced as the pathway product. I engineered several selection strains that depend on different STC modules for growth and determined key enzymes that enable high flux through threonine synthesis and cleavage. I could show that expression of an auxiliary formate dehydrogenase was required to achieve growth via threonine synthesis and cleavage on pyruvate. By overexpressing most of the pathway enzymes from the genome, and applying adaptive laboratory evolution, growth on glycine and formate was achieved, indicating the activity of the complete cycle. The fourth chapter shows the establishment of the reductive glycine pathway (rGP) – a short, linear formate assimilation route – in E. coli. As in the STC, formate is assimilated via M. extorquens FtfL. The C1 from formate is condensed with CO2 via the reverse reaction of the glycine cleavage system to produce glycine. Another carbon from formate is attached to glycine to form serine, which is assimilated into central metabolism via pyruvate. The engineered E. coli strain, expressing most of the pathway genes from the genome, can grow via the rGP with formate or methanol as a sole carbon and energy source.
This thesis offers new insights on the effects of Start-Up Subsidies (SUS) for unemployed individuals as a special kind of active labor market program (ALMP) that aims to re-integrate individuals into the labor market via the route of self-employment. Moreover, this thesis contributes to the literature on methods for causal inference when the treatment variable is continuous rather than binary. For example, this is the case when individuals differ in their degree of exposure to a common treatment.
The analysis of the effects of SUS focuses on the main current German program called “Gründungszuschuss” (New Start-Up Subsidy, NSUS) after its reform in 2011. Average Effects on participants' labor market outcomes - as measured by employment and earnings - as well as subjective well-being are estimated mainly based on propensity score matching (PSM) techniques. PSM aims to achieve balance in terms of observed characteristics by matching participants with at least one comparable non-participant in terms of their probability to receive the treatment. This estimation strategy is valid as long as all relevant characteristics that explain selection patterns into treatment are observed and included in the estimation of the propensity score. To make our analysis as credible as possible, we control for a large vector of characteristics as observed through the combination of rich administrative data from the Federal Employment Agency as well as through survey data.
Chapters two to four of this thesis puts special emphasis on aspects regarding (the evaluation of) SUS programs that have received no or only limited attention thus far. The first aspect relates to the interplay of institutional details of the program and its effectiveness. So far, relatively little is known about the importance of SUS program features such as the duration of support. Second, there is no experimental benchmark evaluation of SUS available and thus, the reliability of non-experimental estimation techniques such as PSM is of crucial importance as estimates are biased when relevant confounders are omitted from the analysis. Third, there may be potentially detrimental effects of transitioning into (relatively risky) self-employment on subjective well-being among subsidized founders out of unemployment. These were to remain undetected if the analysis would focus exclusively on labor market outcomes of participants. The results indicate positive long-term effects of SUS participation on employment and earnings among participants. These effects are substantially larger than what estimated before the reform, indicating room for improvement in program design via changes in institutional details. Moreover, non-experimental estimates of treatment effects are remarkably robust to hidden confounding. Regarding subjective well-being, this thesis finds a positive long-run impact on job satisfaction and a detrimental effect on satisfaction with social security. The latter appears to be driven by adverse effects on social insurance contributions.
In chapter five, a novel automated covariate balancing technique for the estimation of causal effects in the context of continuous treatments is derived and assessed regarding its performance compared to other (automated) balancing techniques. Although binary research designs that only differentiate between participants and non-participants of some treatment remain the most-common case in empirical practice, many applications can be adapted to include continuous treatments as well. Often, this will allow for more meaningful estimates of causal effects in order to further improve the design of programs. In the context of SUS, one may further investigate the effects of the size of monetary support or its duration on participants' labor market outcomes. Both Monte-Carlo investigations and analysis of two well-known datasets suggests superior performance of the proposed Entropy Balancing for continuous treatments (EBCT) compared to other existing estimation strategies.
In beiden deutschen Teilstaaten gehörten die Rentenversicherungen zu den ersten Nutzern von Computern. Bereits seit Mitte der 1950er Jahre berechneten diese die Altersruhegelder im Westen, zehn Jahre später auch in der DDR. Die digitale Datenverarbeitung versprach große Rationalisierungs- und Beschleunigungseffekte. Gleichwohl führten die verschiedenen Staats- und Versicherungsformen zu einer unterschiedlichen Nutzung von Computern.
Die Studie von Thomas Kasper zeigt, unter welchen Bedingungen sich die elektronische Datenverarbeitung in der Sozialverwaltung durchsetzen konnte. Sie verdeutlicht, welchen bisher unbekannten Einfluss sie auf sozialpolitische Entscheidungen sowie auf die Arbeitsverhältnisse und den Datenschutz in beiden deutschen Teilstaaten hatte. Nach der Wiedervereinigung ließ nur die gemeinsame Nutzung der vorhandenen digitalen Strukturen die Zusammenführung beider Sozialsysteme gelingen.
Plants are an attractive platform for the production of medicinal compounds because of their potential to generate large amounts of biomass cheaply. The use of chloroplast transformation is an attractive way to achieve the recombinant production of proteins in plants, because of the chloroplasts’ high capacity to produce foreign proteins in comparison to nuclear transformed plants. In this thesis, the production of two different types of antimicrobial polypeptides in chloroplasts is explored.
The first example is the production of the potent HIV entry inhibitor griffithsin. Griffithsin has the potential to prevent HIV infections by blocking the entry of the virus into human cells. Here the use of transplastomic plants as an inexpensive production method for griffithsin was explored. Transplastomic plants grew healthily and were able to accumulate griffithsin to up to 5% of the total soluble protein. Griffithsin could easily be purified from tobacco leaf tissue and had a similarly high neutralization activity as griffithsin recombinantly produced in bacteria. Griffithsin could be purified from dried tobacco leaves, demonstrating that dried leaves could be used as a storable starting material for griffithsin purification, circumventing the need for immediate purification after harvest.
The second example is the production of antimicrobial peptides (AMPs) that have the capacity to kill bacteria and are an attractive alternative to currently used antibiotics that are increasingly becoming ineffective. The production of antimicrobial peptides was considerably more challenging than the production of griffithsin. Small AMPs are prone to degradation in plastids. This problem was overcome by fusing AMPs to generate larger polypeptides. In one approach, AMPs were fused to each other to increase size and combine the mode of action of multiple AMPs. This improved the accumulation of AMPs but also resulted in impaired plant growth. This was solved by the use of two different inducible systems, which could largely restore plant growth. Fusions of multiple AMPs were insoluble and could not be purified.
In addition to fusing AMPs to each other, the fusion of AMPs to small ubiquitin-like modifier (SUMO), was tested as an approach to improve the accumulation, facilitate purification, and reduce the toxicity of AMPs to chloroplasts. Fusion of AMPs to SUMO indeed increased accumulation while reducing the toxicity to the plants. SUMO fusions produced inside chloroplasts could be purified, and SUMO could be efficiently cleaved off with the SUMO protease. Such fusions therefore provide a promising strategy for the production of AMPs and other small polypeptides inside chloroplasts.
The earth’s ecosystems undergo considerable changes characterized by human-induced alterations of environmental factors. In order to develop conservation goals for vulnerable ecosystems, research on ecosystem functioning is required.. Therefore, it is crucial to explore organismal interactions, such as trophic interaction or competition, which are decisive for key processes in ecosystems. These interactions are determined by the performance responses of organisms to environmental changes, which in turn, are shaped by the organism’s functional traits. Exploring traits, their variation, and the environmental factors that act on them may provide insights on how ecological interactions affect
populations, community structures and dynamics, and thus ecosystem
functioning. In aquatic ecosystems, global warming intensifies
phytoplankton blooms, which are more frequently dominated by
cyanobacteria. As cyanobacteria are poor in polyunsaturated fatty acids
(PUFA) and sterols, this compositional change alters the biochemical
food quality of phytoplankton for consumer species with potential
effects on ecological interactions. Within this thesis, I studied the
effects of biochemical food quality on consumer traits and performance responses at the phytoplankton-zooplankton interface using different strains of two closely related generalist rotifer species Brachionus calyciflorus and Brachionus fernandoi and three phytoplankton species that differ in their biochemical food quality, i.e. in their content and composition of PUFA and sterols. In a series of laboratory feeding experiments I found that biochemical food quality affected rotifer’s performance, i.e. fecundity, survival, and population growth, across a broad range of food quantities. Biochemical food quality constraints,
which are often underestimated as influencing environmental factors, had strong impacts on performance responses. I further explored the potential of biochemical food quality in mediating consumer response variation between species and among strains of one species. Co-limitation by food quantity and biochemical food quality resulted in differences in performance responses, which were more pronounced within than between rotifer species. Furthermore, I demonstrated that the body PUFA compositions of rotifer species and strains were differently affected by the dietary PUFA supply, which indicates inter- and intraspecific differences in physiological traits, such as PUFA retention, allocation, and/or bioconversion capacity, within the genus Brachionus. This indicates that dietary PUFA are involved in shaping traits and performance responses of rotifers. This thesis reveals that biochemical food quality is an environmental factor with strong effects on individual traits and performance responses of consumers. Biochemical food quality constraints can further mediate trait and response variation among species or strains. Consequently, they carry the potential to shape ecological interactions and evolutionary processes with effects on community structures and dynamics. Trait-based approaches, which include food quality research, thus may provide further insights into the linkage between functional diversity and the maintenance of crucial ecosystem functions.
Fiktion und Wirklichkeit
(2020)
Die Untersuchung widmet sich mit der Besteuerung von Ordensgemeinschaften einem bisher in der Rechtswissenschaft vernachlässigten Thema, aus dem größeren Themenbereich der Besteuerung des Dritten Sektors. Die Vernachlässigung verwundert, kommt den Ordensgemeinschaften doch seit Jahrhunderten mit denen von ihnen in Deutschland betriebenen sozialen Einrichtungen eine erhebliche Bedeutung zu. Die vorliegende Arbeit schließt diese Lücke in ansprechender Weise. Durch die Bearbeitung entsteht auch ein übergreifendes Bild des geltenden Besteuerungsregimes im Dritten Sektor und seiner Problemfelder.
Die §§ 299a, 299b StGB sind das Ergebnis eines legitimen gesetzgeberischen Anliegens, die Umsetzung erfolgte indes defizitär.
Der Rechtsgüterschutz ist nicht konsistent, was zu dessen Weiterentwicklung zwingt.
Die unkritische Übernahme der Auslegungsergebnisse zu § 299 StGB – obwohl vom Gesetzgeber intendiert – ist darüber hinaus oftmals verfehlt. Die Arbeit hinterfragt diesen Ansatz und zeigt Lösungen auf.
Um existente Strafbarkeitslücken zu schließen ist es ferner unerlässlich eine verfassungskonforme „Pflichtverletzungsvariante“ einzuführen. Ferner böte eine Clearingstelle Rechtssicherheit, insbesondere mit der Möglichkeit zur Genehmigung von Austauschverhältnissen im Gesundheitswesen. Hierzu werden Vorschläge gemacht.
Algorithmen in der Justiz
(2020)
Unter welchen Bedingungen dürfen Gerichte in Deutschland digitale Anwendungen zur Entscheidungsfindung einsetzen? Das Werk zeigt die engen Grenzen und einen Lösungsweg hierfür auf. Neben rechtstheoretischen und durch die computerspezifische Arbeitsweise gesetzten Grenzen ist der durch das Grundgesetz und das Europarecht abgesteckte Rechtsrahmen zu beachten. Im Zentrum der Bearbeitung steht die Garantie der richterlichen Unabhängigkeit, die durch den Technikeinsatz nicht infrage gestellt werden darf. Zur Auflösung des daraus resultierenden Konflikts wird ein Zertifizierungsverfahren für determinierte Programme vorgeschlagen. Schließlich werden konkrete Anwendungsbeispiele beleuchtet.
Um auch die unbeabsichtigten Folgen ihrer Politik zu ermitteln, unternehmen Regierungen umfassende Gesetzesfolgenabschätzungen. Immer häufiger lassen sie sich dabei von unabhängigen Expertengremien kontrollieren. Doch: Wie erzielen diese Gremien Einfluss? Und welche Rolle spielen sie als Politikberater für Bürokratieabbau und bessere Rechtsetzung? Das Buch eröffnet neue Einblicke in die Entwicklungshistorie und Handlungsrealität der drei erfahrensten Normenkontrollräte in Europa. Vor dem Hintergrund unterschiedlicher Verwaltungskulturen werden die Ratstypen „Wachhund“, „Torwächter“ und „Kritischer Freund“ herausgearbeitet. Die Ergebnisse schärfen die politische und wissenschaftliche Debatte um die Leistungsfähigkeit von Normenkontrollräten.
‘The Territorialities of U.S. Imperialisms’ sets into relation U.S. imperial and Indigenous conceptions of territoriality as articulated in U.S. legal texts and Indigenous life writing in the 19th century. It analyzes the ways in which U.S. legal texts as “legal fictions” narratively press to affirm the United States’ territorial sovereignty and coherence in spite of its reliance on a variety of imperial practices that flexibly disconnect and (re)connect U.S. sovereignty, jurisdiction and territory.
At the same time, the book acknowledges Indigenous life writing as legal texts in their own right and with full juridical force, which aim to highlight the heterogeneity of U.S. national territory both from their individual perspectives and in conversation with these legal fictions. Through this, the book’s analysis contributes to a more nuanced understanding of the coloniality of U.S. legal fictions, while highlighting territoriality as a key concept in the fashioning of the narrative of U.S. imperialism.
Escaping the plant cell
(2020)
The PhD thesis entitled “Actions through the lens of communicative cues. The influence of verbal cues and emotional cues on action processing and action selection in the second year of life” is based on four studies, which examined the cognitive integration of another person’s communicative cues (i.e., verbal cues, emotional cues) with behavioral cues in 18- and 24-month-olds. In the context of social learning of instrumental actions, it was investigated how the intention-related coherence of either a verbally announced action intention or an emotionally signaled action evaluation with an action demonstration influenced infants’ neuro-cognitive processing (Study I) and selection (Studies II, III, IV) of a novel object-directed action. Developmental research has shown that infants benefit from another’s behavioral cues (e.g., action effect, persistency, selectivity) to infer the underlying goal or intention, respectively, of an observed action (e.g., Cannon & Woodward, 2012; Woodward, 1998). Particularly action effects support infants in distinguishing perceptual action features (e.g., target object identity, movement trajectory, final target object state) from conceptual action features such as goals and intentions. However, less is known about infants’ ability to cognitively integrate another’s behavioral cues with additional action-related communicative cues. There is some evidence showing that in the second year of life, infants selectively imitate a novel action that is verbally (“There!”) or emotionally (positive expression) marked as aligning with the model’s action intention over an action that is verbally (“Whoops!”) or emotionally (negative expression) marked as unintentional (Carpenter, Akhtar, & Tomasello, 1998; Olineck & Poulin-Dubois, 2005, 2009; Repacholi, 2009; Repacholi, Meltzoff, Toub, & Ruba, 2016). Yet, it is currently unclear which role the specific intention-related coherence of a communicative cue with a behavioral cue plays in infants’ action processing and action selection that is, whether the communicative cue confirms, contrasts, clarifies, or is unrelated to the behavioral cue. Notably, by using both verbal cues and emotional cues, we examined not only two domains of communicative cues but also two qualitatively distinct relations between behavioral cues on the one hand and communicative cues on the other hand. More specifically, a verbal cue has the potential to communicate an action intention in the absence of an action demonstration and thus a prior-intention (Searle, 1983), whereas an emotional cue evaluates an ongoing or past action demonstration and thus signals an intention-in-action (Searle, 1983). In a first research focus, this thesis examined infants’ capacity to cognitively integrate another’s intention-related communicative cues and behavioral cues, and also focused on the role of the social cues’ coherence in infants’ action processing and action selection. In a second research focus, and to gain more elaborate insights into how the sub-processes of social learning (attention, encoding, response; cf. Bandura, 1977) are involved in this coherence-sensitive integrative processing, we employed a multi-measures approach. More specifically, we used Electroencephalography (EEG) and looking times to examine how the cues’ coherence influenced the compound of attention and encoding, and imitation (including latencies to first-touch and first-action) to address the compound of encoding and response. Based on the action-reconstruction account (Csibra, 2007), we predicted that infants use extra-motor information (i.e., communicative cues) together with behavioral cues to reconstruct another’s action intention. Accordingly, we expected infants to possess a flexibly organized internal action hierarchy, which they adapt according to the cues’ coherence that is, according to what they inferred to be the overarching action goal. More specifically, in a social-learning situation that comprised an adult model, who demonstrated an action on a novel object that offered two actions, we expected the demonstrated action to lead infants’ action hierarchy when the communicative (i.e., verbal, emotional) cue conveyed similar (confirming coherence) or no additional (un-related coherence) intention-related information relative to the behavioral cue. In terms of action selection, this action hierarchy should become evident in a selective imitation of the demonstrated action. However, when the communicative cue questioned (contrasting coherence) the behaviorally implied action goal or was the only cue conveying meaningful intention-related information (clarifying coherence), the verbally/emotionally intended action should ascend infants’ action hierarchy. Consequently, infants’ action selection should align with the verbally/emotionally intended action (goal emulation). Notably, these predictions oppose the direct-matching perspective (Rizzolatti & Craighero, 2004), according to which the observation of another’s action directly resonates with the observer’s motor repertoire, with this motor resonance enabling the identification of the underlying action goal. Importantly, the direct-matching perspective predicts a rather inflexible action hierarchy inasmuch as the process of goal identification should solely rely on the behavioral cue, irrespective of the behavioral cue’s coherence with extra-motor intention-related information, as it may be conveyed via communicative cues. As to the role of verbal cues, Study I used EEG to examine the influence of a confirming (Congruent) versus contrasting (Incongruent) coherence of a verbal action intention with the same action demonstration on 18-month-olds’ conceptual action processing (as measured via mid-latency mean negative ERP amplitude) and motor activation (as measured via central mu-frequency band power). The action was demonstrated on a novel object that offered two action alternatives from a neutral position. We expected mid-latency ERP negativity to be enhanced in Incongruent compared to Congruent, because past EEG research has demonstrated enhanced conceptual processing for stimuli that mismatched rather than matched the semantic context (Friedrich & Friederici, 2010; Kaduk et al., 2016). Regarding motor activation, Csibra (2007) posited that the identification of a clear action goal constitutes a crucial basis for motor activation to occur. We therefore predicted reduced mu power (indicating enhanced motor activation) for Congruent than Incongruent, because in Congruent, the cues’ match provides unequivocal information about the model’s action goal, whereas in Incongruent, the conflict may render the model’s action goal more unclear. Unexpectedly, in the entire sample, 18-month-olds’ mid-latency ERP negativity during the observation of the same action demonstration did not differ significantly depending on whether this action was congruent or incongruent with the model’s verbal action intention. Yet, post hoc analyses revealed the presence of two subgroups of infants, each of which exhibited significantly different mid-latency ERP negativity for Congruent versus Incongruent, but in opposing directions. The subgroups differed in their productive action-related language skills, with the linguistically more advanced infants exhibiting the expected response pattern of enhanced ERP mean negativity in Incongruent than Congruent, indicating enhanced conceptual processing of an action demonstration that was contrasted rather than confirmed by the verbal action context. As expected, central mu power in the entire sample was reduced in Congruent relative to Incongruent, indicating enhanced motor activation when the action demonstration was preceded by a confirming relative to a contrasting verbal action intention. This finding may indicate the covert preparation for a preferential imitation of the congruent relative to the incongruent action (Filippi et al., 2016; Frey & Gerry, 2006). Overall, these findings are in line with the action-reconstruction account (Csibra, 2007), because they suggest a coherence-sensitive attention to and encoding of the same perceptual features of another’s behavior and thus a cognitive integration of intention-related verbal cues and behavioral cues. Yet, because the subgroup constellation in infants’ ERPs was only discovered post hoc, future research is clearly required to substantiate this finding. Also, future research should validate our interpretation that enhanced motor activation may reflect an electrophysiological marker of subsequent imitation by employing EEG and imitation in a within-subjects design. Study II built on Study I by investigating the impact of coherence of a verbal cue and a behavioral cue on 18- and 24-month-olds’ action selection in an imitation study. When infants of both age groups observed a confirming (Congruent) or unrelated (Pseudo-word: action demonstration was associated with novel verb-like cue) coherence, they selectively imitated the demonstrated action over the not demonstrated, alternative action, with no difference between these two conditions. These findings suggest that, as expected, infants’ action hierarchy was led by the demonstrated action when the verbal cue provided similar (Congruent) or no additional (Pseudo-word) intention-related information relative to a meaningful behavioral cue. These findings support the above-mentioned interpretation that enhanced motor activation during action observation may reflect a covert preparation for imitation (Study I). Interestingly, infants did not seem to benefit from the intention-highlighting effect of the verbal cue in Congruent, suggesting that the verbal cue had an unspecific (e.g., attention-guiding) effect on infants’ action selection. Contrary, when infants observed a contrasting (Incongruent) or clarifying (Failed-attempt: model failed to manipulate the object but verbally announced a certain action intention) coherence, their action selection varied with age and also varied across the course of the experiment (block 1 vs. block 2). More specifically, the 24-month-olds made stronger use of the verbal cue for their action selection in block 1 than did the 18-month-olds. However, while the 18-month-olds’ use of the verbal cue increased across blocks, particularly in Incongruent, the 24-month-olds’ use of the verbal cue decreased across blocks. Overall, these results suggest that, as expected, infants’ action hierarchy in Incongruent (both age groups) and Failed-attempt (only 24-month-olds) drew on the verbal action intention, because in both age groups, infants emulated the verbal intention about as often as they imitated the demonstrated action or even emulated the verbal action intention preferentially. Yet, these findings were confined to certain blocks. It may be argued that the younger age group had a harder time inferring and emulating the intended, yet never observed action, because this requirement is more demanding in cognitive and motor terms. These demands may explain why the 18-month-olds needed some time to take account of the verbal action intention. Contrary, it seems that the 24-month-olds, although demonstrating their principle capacity to take account of the verbal cue in block 1, lost trust in the model’s verbal cue, maybe because the verbal cue did not have predictive value for the model’s actual behavior. Supporting this interpretation, research on selective trust has demonstrated that already infants evaluate another’s reliability or competence, respectively, based on how that model handles familiar objects (behavioral reliability) or labels familiar objects (verbal reliability; for reviews, see Mills, 2013; Poulin-Dubois & Brosseau-Liard, 2016). Relatedly, imitation research has demonstrated that the interpersonal aspects of a social-learning situation gain increasing relevance for infants during the second year of life (Gellén & Buttelmann, 2019; Matheson, Moore, & Akhtar, 2013; Uzgiris, 1981). It may thus be argued that when the 24-month-olds were repeatedly faced with a verbally unreliable model, they de-evaluated the verbal cue as signaling the model’s action intention and instead relied more heavily on alternative cues such as the behavioral cue (Incongruent) or the action context (e.g., object affordances, salience; Failed-attempt). Infants’ first-action latencies were higher in Incongruent and Failed-attempt than in both Congruent and Pseudo-word, and were also higher in Failed-attempt than in Incongruent. These latency-findings thus indicate that situations involving a meaningful verbal cue that deviated from the behavioral cue are cognitively more demanding, resulting in a delayed initiation of a behavioral response. In sum, the findings of Study II suggest that both age groups were highly flexible in their integration of a verbal cue and behavioral cue. Moreover, our results do not indicate a general superiority of either cue. Instead, it seems to depend on the informational gain conveyed by the verbal cue whether it exerts a specific, intention-highlighting effect (Incongruent, Failed-attempt) or an unspecific (e.g., attention-guiding) effect (Congruent, Pseudo-word). Studies III and IV investigated the impact of another’s action-related emotional cues on 18-month-olds’ action selection. In Study III, infants observed a model, who demonstrated two actions on a novel object in direct succession, and who combined one of the two actions with a positive (happy) emotional expression and the other action with a negative (sad) emotional expression. As expected, infants imitated the positively emoted (PE) action more often than the negatively emoted (NE) action. This preference arose from an increase in infants’ readiness to perform the PE action from the baseline period (prior to the action demonstrations) to the test period (following the action demonstrations), rather than from a decrease in readiness to the perform the NE action. The positive cue thus had a stronger behavior-regulating effect than the negative cue. Notably, infants’ more general object-directed behavior in terms of first-touch latencies remained unaffected by the emotional cues’ valence, indicating that infants had linked the emotional cues specifically to the corresponding action and not the object as a whole (Repacholi, 2009). Also, infants’ looking times during the action demonstration did not differ significantly as a function of emotional valence and were characterized by a predominant attentional focus to the action/object rather than to the model’s face. Together with the findings on infants’ first-touch latencies, these results indicate a sensitivity for the notion that emotions can have very specific referents (referential specificity; Martin, Maza, McGrath, & Phelps, 2014). Together, Study III provided evidence for selective imitation based on another’s intention-related (particularly positive) emotional cues in an action-selection task, and thus indicates that infants’ action hierarchy flexibly responds to another’s emotional evaluation of observed actions. According to Repacholi (2009), we suggest that infants used the model’s emotional evaluation to re-appraise the corresponding action (effect), for instance in terms of desirability. Study IV followed up on Study III by investigating the role of the negative emotional cue for infants’ action selection in more detail. Specifically, we investigated whether a contrasting (negative) emotional cue alone would be sufficient to differentially rank the two actions along infants’ action hierarchy or whether instead infants require direct information about the model’s action intention (in the form of a confirming action-emotion pair) to align their action selection with the emotional cues. Also, we examined whether the absence of a direct behavior-regulating effect of the negative cue in Study III was due to the negative cue itself or to the concurrently available positive cue masking the negative cue’s potential effect. To this end, we split the demonstration of the two action-emotion pairs across two trials. In each trial, one action was thus demonstrated and emoted (PE, NE action), and one action was not demonstrated and un-emoted (UE action). For trial 1, we predicted that infants, who observed a PE action demonstration, would selectively imitate the PE action, whereas infants, who observed a NE action demonstration would selectively emulate the UE action. As to trial 2, we expected the complementary action-emotion pair to provide additional clarifying information as the model’s emotional evaluation of both actions, which should either lead to adaptive perseveration (if infants’ action selection in trial 1 had already drawn on the emotional cue) or adaptive change (if infants’ action selection in trial 1 signaled a disregard of the emotional cue). As to trial 1, our findings revealed that, as expected, infants imitated the PE action more often than they emulated the UE action. Like in Study III, this selectivity arose from an increase in infants’ propensity to perform the PE action from baseline to trial 1. Also like in Study III, infants performed the NE action about equally often in baseline and trial 1, which speaks against a direct behavior-regulating effect of the negative cue also when presented in isolation. However, after a NE action demonstration, infants emulated the UE action more often in trial 1 than in baseline, suggesting an indirect behavior-regulating effect of the negative cue. Yet, this indirect effect did not yield a selective emulation of the UE action, because infants performed both action alternatives about equally often in trial 1. Unexpectedly, infants’ action selection in trial 2 was unaffected by the emotional cue. Instead, infants perseverated their action selection of trial 1 in trial 2, irrespective of whether it was adaptive or non-adaptive with respect to the model’s emotional evaluation of the action. It seems that infants changed their strategy across trials, from an initial adherence to the emotional (particularly positive) cue, towards bringing about a salient action effect (Marcovich & Zelazo, 2009). In sum, Studies III and IV indicate a dynamic interplay of different action-selection strategies, depending on valence and presentation order. Apparently, at least in infancy, action reconstruction as one basis for selective action performance reaches its limits when infants can only draw on indirect intention-related information (i.e., which action should be avoided). Overall, our findings favor the action-reconstruction account (Csibra, 2007), according to which actions are flexibly organized along a hierarchy, depending on inferential processes based on extra-motor intention-related information. At the same time, the findings question the direct-matching hypothesis (Rizzolatti & Craighero, 2004), according to which the identification (and pursuit) of action goals hinges on a direct simulation of another’s behavioral cues. Based on the studies’ findings, a preliminary working model is introduced, which seeks to integrate the two theoretical accounts by conceptualizing the routes that activation induced by social cues may take to eventually influence an infant’s action selection. Our findings indicate that it is useful to strive a differentiated conceptualization of communicative cues, because they seem to operate at different places within the process of cue integration, depending on their potential to convey direct intention-related information. Moreover, we suggest that there is bidirectional exchange within each compound of adjacent sub-processes (i.e., between attention and encoding, and encoding and response), and between the compounds. Hence, our findings highlight the benefits of a multi-measures approach when studying the development of infants’ social-cognitive abilities, because it provides a more comprehensive picture how the concerted use of social cues from different domains influences infants’ processing and selection of instrumental actions. Finally, this thesis points to potential future directions to substantiate our current interpretation of the findings.. Moreover, an extension to additional kinds of coherence is suggested to get closer to infants’ everyday-world of experience.
Magnetotactic bacteria comprise a heterogeneous group of Gram negative bacteria which share the ability to synthesise intracellular magnetic nanoparticles surrounded by a lipid bilayer, known as magnetosomes, which are arranged in linear chains. The bacteria exert a unique level of control onto the biomineralization of these nanoparticles, which is seen in the controlled size and shape they have. These characteristics have attracted great attention on understanding the process by which the bacteria synthesise the magnetosomes. Moreover, the magnetosome chain impart the bacteria with a net magnetic dipole which makes them susceptible to interact with magnetic fields and thus orient with the Earth’s magnetic field. This feature has attracted as well much interest to understand how the swimming motility of these microorganisms is affected by the presence of magnetic fields. Most of the studies performed in these bacteria so far have been conducted in the traditional manner using large populations of cells. Such studies have the disadvantage of averaging many different individuals with heterogeneous behaviours and fail to consider individual variations. In addition, in large populations each bacterium will be subjected to a different microenvironment that will influence the bacterial behaviour, but which cannot be defined using these traditional methods. In this thesis, different microfluidic platforms are proposed to overcome these limitations and to offer the possibility to study magnetotactic bacteria in defined environments and down to a single-cell resolution. First, a sediment-like microfluidic platform is presented with the purpose of mimicking the porous environment they bacteria naturally dwell in. The platform allows to observe via transmitted light microscopy that bacterial navigation in crowded environments is enhanced by the Earth’s magnetic field strengths (B = 50 μT) rather than by null (B = 0 μT) or higher magnetic fields (B = 500 μT). Second, a microfluidic system to confine single-bacterial cells in physically defined environments is presented. The system allows to study via transmitted light microscopy the interplay between wall curvature, magnetic fields and bacterial speed affect the motion of a confined bacterium, and shows how bacterial trajectories depend on those three parameters. Third, a microfluidic platform to conduct semi in vivo magnetosome nucleation with a single-cell resolution via X-ray fluorescence is fabricated. It is shown that signal arising from magnetosome full chains can be observed individually in each bacterium. Finally, the iron uptake kinetics of a single bacterium are studied via a fluorescent reporter through confocal microscopy. Two different approaches are used for this: one of the previously mentioned platforms, as well as giant lipid vesicles. It is observed how iron uptake rates vary between cells, as well as how these rates are consistent with magnetosome formation taking place within some hours. The present thesis shows therefore how microfluidic technologies can be implemented for the study of magnetotactic bacteria at different degrees, and the level of resolution that can be attained by going into the single- cell scale.
Die vorliegende Dissertationsschrift mit dem Titel: „Ruthenium(II)- und Rhenium(I)-Komplexe des 1,6,7,12-Tetraazaperylens und seiner Dimethyl- und Tetramethylderivate“ von Matthias Kirste wurde unter der Leitung des Herrn Prof. Dr. Hans-Jürgen Holdt am Institut für Chemie der Universität Potsdam angefertigt. Die Arbeit beschäftigt sich mit Ruthenium(II)- und Rhenium(I)-Komplexen des großflächigen Liganden 1,6,7,12-Tetraazaperylen (tape) und seiner 2,11-Dimethyl-(dmtape)- und 2,5,8,11-Tetramethyl-(tmtape)-derivate. Es wurden die bekannten Herstellungen des tape- sowie des dmtape-Liganden verbessert und die Synthese des tmtape-Liganden neu entwickelt. Zudem gelang mit einer neu entwickelten chemischen Reaktion die Synthese des dianionischen 3,10-Disulfonato-1,6,7,12-tetraazaperylens. Mit dmtape und tmtape wurde jeweils ein neuer Ruthenium(II)-Komplex hergestellt. Die Komplexe wurden photophysikalisch und elektrochemisch charakterisiert. KT-DNS-Interkalationen wurden von einkernigen Ruthenium(II)-Komplexen mit jeweils tape-, dmtape- und tmtape als interkalative Einheit vermessen. Es zeigte sich, dass diese Komplexe mit einer hohen Bindungsaffinität in die doppelsträngige KT-DNS interkalieren. Aus den mononuklearen Ruthenium(II)-Komplexen gelang die Herstellung von heterodinuklearen RuIIReI-Komplexen, die charakteristische Signale in ihren UV/Vis-Absorptionsspektren zeigen und sehr leicht jeweils ein- sowie zweifach im Bereich von 70 mV bis -80 mV und -440 mV bis -600 mV vs. GKE reduzierbar sind. Diese dmtape- sowie tmtape-verbrückten heterodinuklearen RuIIReI-Komplexe ermöglichen eine Feinjustierung ihrer photophysikalischen und elektrochemischen Eigenschaften, wobei in dieser Arbeit mithilfe einer chemischen Reaktion eine gezielte Einstellung dieser Eigenschaften gezeigt werden konnte. Metallkomplexe mit solchen charakteristischen, leicht einstellbaren photophysikalischen sowie elektrochemischen Eigenschaften sind geeignete Sensor- und Elektronen-Shuttle-Moleküle besonders für bioanalytische Einsatzgebiete. Zudem könnten die vielen Einstellmöglichkeiten der elektronischen Struktur dieser Komplexe sehr interessant für katalytische Anwendungen sein.
This dissertation examines the activity of knowledge sharing by public employees in the workplace. Building on the Rubicon model of human behavior formation, I use a threefold approach to analyze the knowledge-sharing process: public employees’ motivation to share knowledge, their intention to share, and knowledge sharing behavior as such. The first article maps the knowledge-sharing behavior of public employees. It builds a typology of behavioral patterns and shows that public employees mainly share their knowledge responsively and directly with a knowledge receiver rather than an information medium. The second article elaborates on the construct of knowledge-sharing motivation and develops a scale to measure this kind of work motivation in a selective and domain-specific way. Data from three studies indicate three dimensions of knowledge-sharing motivation, namely appreciation, growth and altruism, and tangible rewards. Based on these dimensions, the third article analyzes whether the satisfaction of public employees’ underlying needs can foster ther knowledge-sharing intention. The study indicates that both tested treatments (appreciation by co-workers, benefits in a performance appraisal) positively affect knowledge-sharing intention if it is explicit knowledge that ought to be shared. However, no effects of either treatment can be found if implicit knowledge is shared. Hence, to foster sharing of explicit knowledge, the analyzed motivation-enhancing rewards can be used in public management practice. To enhance implicit knowledge sharing, ability- and opportunity-enhancing management instruments are discussed. All in all, this dissertation integrates a micro-level perspective on human knowledge sharing into a meso-level perspective on organizational knowledge management. It adds to the literature on workplace behaviors of public employees and knowledge management and aims to incorporate knowledge sharing and management into the public administration and management literature.
One of the tremendous discoveries by the Cassini spacecraft has been the detection of propeller structures in Saturn's A ring. Although the generating moonlet is too small to be resolved by the cameras aboard Cassini, its produced density structure within the rings, caused by its gravity can be well observed. The largest observed propeller is called Blériot and has an azimuthal extent over several thousand kilometers. Thanks to its large size, Blériot could be identified in different images over a time span of over 10 years, allowing the reconstruction of its orbital evolution. It turns out that Blériot deviates considerably from its expected Keplerian orbit in azimuthal direction by several thousand kilometers. This excess motion can be well reconstructed by a superposition of three harmonics, and therefore resembles the typical fingerprint of a resonantly perturbed body. This PhD thesis is directed to the excess motion of Blériot. Resonant perturbations are a known for some of the outer satellites of Saturn. Thus, in the first part of this thesis, we seek for suiting resonance candidates nearby the propeller, which might explain the observed periods and amplitudes. In numeric simulations, we show that indeed resonances by Prometheus, Pandora and Mimas can explain the libration periods in good agreement, but not the amplitudes. The amplitude problem is solved by the introduction of a propeller-moonlet interaction model, where we assume a broken symmetry of the propeller by a small displacement of the moonlet. This results in a librating motion the moonlet around the propeller's symmetry center due to the non-vanishing accelerations. The retardation of the reaction of the propeller structure to the motion of the moonlet causes the propeller to become asymmetric. Hydrodynamic simulations to test our analytical model confirm our predictions. In the second part of this thesis, we consider a stochastic migration of the moonlet, which is an alternative hypothesis to explain the observed excess motion of Blériot. The mean-longitude is a time-integrated quantity and thus introduces a correlation between the independent kicks of a random walk, smoothing the noise and thus makes the residual look similar to the observed one for Blériot. We apply a diagonalization test to decorrelated the observed residuals for the propellers Blériot and Earhart and the ring-moon Daphnis. It turns out that the decorrelated distributions do not strictly follow the expected Gaussian distribution. The decorrelation method fails to distinguish a correlated random walk from a noisy libration and thus we provide an alternative study. Assuming the three-harmonic fit to be a valid representation of the excess motion for Blériot, independently from its origin, we test the likelihood that this excess motion can be created by a random walk. It turns out that a non-correlated and correlated random walk is unlikely to explain the observed excess motion.
Die vorgelegte Arbeit besteht aus drei Teilprojekten, der Realisierung eines Multiparametersensors (Temperatur, pH-Wert und Sauerstoffkonzentration), der Konzipierung und Untersuchung eines optischen Atemgassensors und Untersuchungen zur Anwendung des Konzeptes der Sauerstofflöschung in der Immuntechnologie. Zur Realisierung des Multiparametersensors wurden die einzelnen Sensorfarbstoffe, sofern notwendig, synthetisiert und anschließend einzeln unter Laborbedingungen charakterisiert. Im weiteren Verlauf wurde ein Versuchsaufbau konzipiert mit dem es möglich ist, alle verwendeten Sensorfarbstoffe mit einer Anregungsquelle anzuregen. Dabei erfolgte die Detektion der Parameter Temperatur und Sauerstoffkonzentration mittels Phasenmodulationsspektroskopie und die pH-Wert-bestimmung mittels stationärer Fluoreszenzspektroskopie. So konnte ein Multiparametersensor konzipiert werden, mit dem es möglich ist, die drei genannten Parameter simultan, in Echtzeit und ohne externe Temperaturmessung zu detektieren. Im Rahmen der Entwicklung eines optischen Atemgassensors konnte zunächst eine neue Sensorform entwickelt werden. Durch diese neue Sensorform, welche sich durch sehr kurze Ansprechzeiten auszeichnet, ist es möglich den Sauerstoffgehalt in der Exspirationsluft sehr detailreich zu erfassen. Durch freiwillige Selbstversuche mit dem Atemgassensor konnte eine Korrelation mit einer etablierten Untersuchungsmethode hergestellt werden. Während der Untersuchungen zur Anwendung des Konzeptes der Sauerstofflöschung in der Immuntechnologie konnte zunächst ein Modell entwickelt werden, welches die Wechselwirkung zwischen Antikörper und synthetisiertem Farbstoff, welcher als Antigen fungierte, beschreibt. Nachdem weiterhin eine Wechselwirkung zwischen Antikörper und Antigen in einfachen Medien, wie PBS-Pufferlösung, gezeigt werden konnte, gelang dies auch in komplexen Medien wie bovinem Serum, Kuhmilch oder Speichelflüssigkeit. So konnte ein System entwickelt werden, mit dem es möglich ist Antikörper-Antigen-Wechselwirkungen in komplexen biologischen Medien zu verfolgen.
NADPH is an essential cofactor that drives biosynthetic reactions in all living organisms. It is a reducing agent and thus electron donor of anabolic reactions that produce major cellular components as well as many products in biotechnology. Indeed, the engineering of metabolic pathways for the production of many products is often limited by the availability of NADPH. One common strategy to address this issue is to swap cofactor specificity from NADH to NADPH of enzymes. However, this process is time consuming and challenging because multiple parameters need to be engineered in parallel. Therefore, the first aim of this project is to establish an efficient metabolic biosensor to select enzymes that can reduce NADP+. An NADPH auxotroph strain was constructed by deleting major reactions involved in NADPH biosynthesis in E. coli’s central carbon metabolism with the exception of 6-phosphogluconate dehydrogenase. To validate this strain, two enzymes were tested in the presence of several carbon sources: a dihydrolipoamide dehydrogenase variant of E. coli harboring seven mutations and a formate dehydrogenase (FDH) from Mycobacterium vaccae N10 harboring four mutations were found to support NADPH biosynthesis and growth. The strain was subjected to adaptive laboratory evolution with the goal of testing its robustness under different carbon sources. Our evolution experiment resulted in the random mutagenesis of the malic enzyme (maeA), enabling it to produce NADPH. The additional deletion of maeA rendered a more robust second-generation biosensor strain for NADP+ reduction. We devised a structure-guided directed evolution approach to change cofactor specificity in Pseudomonas sp. 101 FDH. To this end, a library of >106 variants was tested using in vivo selection. Compared to the best engineered enzymes reported, our best variant carrying five mutations shows 5-fold higher catalytic efficiency and 13-fold higher specificity towards NADP+, as well as 2-fold higher affinity towards formate. In conclusion, we demonstrate the potential of in vivo selection and evolution-guided approaches to develop better NADPH biosensors and to engineer cofactor specificity by the simultaneous improvement of multiple parameters (kinetic efficiency with NADP+, specificity towards NADP+, and affinity towards formate), which is a major challenge in protein engineering due to the existence of tradeoffs and epistasis.
Im internationalen Deliktsrecht kommt es immer wieder zu Friktionen, wenn das anwendbare Recht nicht dem Recht des Ortes der schädigenden Handlung entspricht. Der maßgebliche haftungsbegründende Verhaltensmaßstab ist für den Schädiger, der sich im Regelfall am Recht des Handlungsortes orientiert, in solchen Konstellationen nur schwer vorherzusehen. Der europäische Verordnungsgeber hat daher mit Art. 17 Rom-II-VO eine Norm geschaffen, die die „Berücksichtigung” von Sicherheits- und Verhaltensregeln des Handlungsortes unabhängig vom anwendbaren Recht allgemein anordnet. Diese „Berücksichtigung” statutsfremder Regeln ist ein Fremdkörper im hergebrachten Methodengefüge des kontinentalen IPR. Vor diesem Hintergrund untersucht Yannick Diehl Möglichkeiten zur Entwicklung einer tragfähigen dogmatischen Untermauerung der bisher zu großen Teilen diffus gebliebenen Rechtsfigur.
Zufriedenheitsanalysen durch Patientenbefragungen, wie in diesem Fall der neu entwickele und getestet Fragebogen (HNO-PROM), haben drei Säulen. Es kann zum einen eine bessere Patientenbindung geschaffen werden, die Qualität kann gemessen, verglichen und optimiert werden und es kann ein Mitarbeiterleitfaden im Sinne einer „Corporate Identity“ erstellt werden, welcher konkrete Managementimplikationen im Sinne von Handlungsimplikationen enthält. Der Leitgedanke des Qualitätsmanagements ist die Patientenorientierung im Sinne der Patientenzentrierten Medizin. Hierbei sollen nicht nur Wünsche und Bedürfnisse des Patienten erfüllt werden, sondern vorallem auch die Zufriedenheit gemessen und geplant werden. Gleichzeit muss man in diesem Zusammenhang die Behandlung der Patienten als Dienstleistung verstehen und die größtmögliche Zufriedenheit des Patienten als primäres Ziel setzen. Dies führt zu einer Kundenbindung dadurch, dass Patienten sowohl eine gleichbleibende Qualität erwarten können als auch und auch weiche Faktoren ihren Wünschen entsprechen werden. Corporate Identity mit dem Ziel als Unternehmen einheitlich für die Werte und damit die Qualität zu stehen.. Dies ermöglicht, das Wohlbefinden in der Vorstellung der Patienten beginnen zu lassen und dadurch Vertrauen zu schaffen. Alle drei Säulen haben nicht nur die Patientenzufriedenheit zum Ziel, sondern in gleichem Maße auch die Positionierung einer Institution auf dem Gesundheitsmarkt und damit die Verbesserung der Kosten-Nutzen-Rechnung durch ein positives Outcome. Damit fördern Zufriedenheitsanalysen nicht nur die ökonomische Position einer Abteilung, sondern behalten gleichermaßen die ethischen Aspekte einer Arzt-Patienten-Beziehung im Blick.
The idea of critical childhood studies is a relatively young disciplinary undertaking in eastern Africa. And so, a lot of inquiries have not been carried out. This field is a potential important socio-political marker, among others, of some narratives, that have emerged out of eastern Africa. Towards this end, my research seeks out an archaeology of childhood in eastern Africa. There is a monochromatic hue which has often painted the eastern African childhood. This broad stroke portrays the childhood as characterized by want. The image of the eastern African childhood is composed in terms of the war-child, poverty, disease-ridden, and aid-begging. The pitfall of this consciousness is that it erases a differentiated and pluralist nature of the eastern African childhood. Therefore, I hypothesise that childhood is a discourse from which institutional vectors become conduits of certain statement-making both process-wise and content-wise. As such a critical childhood study is a theatre of staging and unearthing its joys, tribulations, cultural constructions, and even political interventions. To this end childhood and its literatures not only reflect but also contribute to meaning making and worldliness thereof. As an attempt to move from an un-nuanced depiction, which is often monodirectional, I seek to present a chronologically synchronic and diachronic analysis of childhood in the eastern Africa. Accordingly, I excavate a chronological construction of childhood within this geopolitical region. The main conceptual anchorage is Francis Nyamnjoh who tells of the African occupying a life on convivial frontiers. He theorises an Africa that is involved in technologies of self-definition that privilege conversations, fluidity of being and relational connections on a globalised scale. I also appropriate the notion of Bula Matadi from the Congo as a decolonialist epistemological exercise to break apart polarising representations and practices of childhood in eastern Africa. This opens a space for an unbounded reconfiguration of childhood in eastern Africa. This book works on and with archival matter, in a cross-disciplinary manner and ranges from pre-colonial to post-colonial eastern Africa. It is an exploration of the trajectory of the discourse of childhood in eastern Africa, in order to eclectically investigate childhood in eastern Africa, in fictional and non-fictional representations.
Unter Verschluss
(2020)
In recent years the development of renewable energy sources attracted much attention due to the increasing environmental pollution induced by burning fossil fuels. The growing public interest in reducing greenhouse gases and the use of pollution-free energies (bio-mass-, geothermal-, solar-, water- or wind energy) paved the way for scientific research in renewable energies. [1] Solar energy provides unlimited access and offers high applicational flexibility, which is needed for energy consumption in a modern society. The scientific interest in photovoltaics (PV) nowadays focuses on discovering new materials and improving materials properties, aiming for the production of highly efficient solar cells. Lately, a new type of absorber material based on the perovskite type structure reached power conversion efficiencies of more than 24%. [2] By varying the chemical composition the electronic properties as e.g. the band gap energy can be tuned to increase the absorption range of this absorber material. This makes them in particular attractive for use in tandem solar cells, where silicon and perovskite absorber layers are combined to absorb a large range of the vible light (28.0% efficiency). [2] However, perovskite based solar cells not only suffer from fast degradation when exposed to humidity, but also from the use of toxic elements (e.g. lead), which can result in long-term environmental damage. Therefore, the aim of this study was to determine the fundamental structural and optoelectronical properties of highly interesting hybrid perovskite materials, the MAPbX3 solid solution (MA=CH3NH3; X=I,Br,Cl) and the triple cation (FA1-xMAx)1-yCsyPbI3 solid solution (FA=HC(NH2)2). The study was performed on powder samples by using X-ray diffraction, revealing the crystal structure and solubility behavior of all solid solutions. Moreover the temperature-dependent behavior was studied using in-situ high resolution synchrotron X-ray diffraction and combinatorial thermal analysis methods. The influence of compositional changes on the band gap energy variation were observed using spectroscopic methods as photoluminescence and diffuse reflectance spectroscopy. The obtained results have shown that for the MAPb(I1-xBrx)3 solid solution a large miscibility gap in the range of 0.29 ( ± 0.02) ≤ x ≤ 0.92 ( ± 0.02) is present. This miscibility gap limits the suitable compositional range for use in thin film solar cells of mixed halide compounds. From the temperature-dependent in-situ synchrotron X-ray diffraction studies the complete T-X-phase diagram was established. Studies on the MAPb(Cl1-xBrx)3 solid solution revealed that MAPb(Cl1-xBrx)3 forms a complete solid solution series. For the triple cation (FA1-xMAx)1-yCsyPbI3 solid solution the aim was to study the formation of the d-modification in FAPbI3, which is undesired for solar cell application. This can be overcome by stabilizing the favored high temperature cubic a-modification at ambient conditions. By partial substituting the formamidinium molecule by methylammonium and cesium the stabilization of the cubic modification was successful. The solubility limit of FA1-xCsxPbI3 solid solution was determined to be x=0.1, while a full miscibility was observed for the FA1-xMAxPbI3 solid solution. For the triple cation (FA1-xMAx)1-yCsyPbI3 solid solution a solubility limit of cesium was observed to be y=0.1. The optoelectronic properties were investigated, revealing a linear change of band gap energy with chemical composition. It is demonstrated that the stabilized triple cation compound with cubic perovskite-type crystal structure shows enhanced stability of approximately six months. Furthermore, a short insight into lead-free perovskite-type materials is given, using germanium as non-toxic alternative to lead. For germanium based perovskites a fast decomposition in air was observed, due to the preferred formation of GeI4 in oxygen atmosphere. In-situ low temperature synchrotron X-ray diffraction measurements revealed a yet unknown low temperature modification of MAGeI3. [1] WESSELAK, Viktor; SCHABBACH, Thomas; LINK, Thomas; FISCHER, Joachim: Handbuch Regenerative Energietechnik. Springer, 2017 [2] NREL: Best Research-Cell Efficiencies. https://www.nrel.gov/pv/assets/pdfs/best-research-cell-efficiencies-190416.pdf. – 25.04.2019
Carbon nitride and poly(ionic liquid)s (PILs) have been successfully applied in various fields of materials science owing to their outstanding properties. This thesis aims at the successful application of these polymers as innovative materials in the interfaces of hybrid organic–inorganic perovskite solar cells. A critical problem in harnessing the full thermodynamic potential of halide perovskites in solar cells is the design and modification of interfaces to reduce carrier recombination. Therefore, the interface must be properly studied and improved. This work investigated the effect of applying carbon nitride and PILs on a perovskite surface on the device performance. The facile synthetic method for modifying carbon nitride with vinyl thiazole and barbituric acid (CMB-vTA) yields 2.3 nm layers when solution processing is performed using isopropanol. The nanosheets were applied as a metal-free electron transport layer in inverted perovskite solar cells. The application of carbon nitride layers (CMB-vTA) resulted in negligible current-voltage hysteresis with a high open circuit voltage (Voc) of 1.1 V and a short-circuit current (Jsc) of 20.28 mA cm-2, which afforded efficiencies of up to 17%. Thus, the successful implementation of a carbon nitride-based structure enabled good charge extraction with minimized interface recombination between the perovskite and PCBM. Similarly, PILs represent a new strategy of interfacial modification using an ionic polymer in an n-i-p perovskite architecture.. The application of PILs as an interfacial modifier resulted in solar cell devices with an extraordinarily high efficiency of 21.8% and a Voc of 1.17 V. The implementation reduced non-radiative recombination at the perovskite surface through defect passivation. Finally, our work proposes a novel method to efficiently suppress non-radiative charge recombination using the unexplored properties of carbon nitride and PILs in the solar cell field. Additionally, the method for interfacial modification has general applicability because of the simplicity of the post-treatment approach, and therefore has potential applicability in other solar cells. Thus, this work opens the door to a new class of materials to be implemented.
Der zentralasiatische Naturraum, wie er sich uns heute präsentiert, ist das Ergebnis eines Zusammenwirkens vieler verschiedener Faktoren über Jahrmillionen hinweg. Im aktuellen Kontext des Klimawandels zeigt sich jedoch, wie stark sich Stoffflüsse auch kurzfristig ändern und dabei das Gesicht der Landschaft verwandeln können. Die Gobi-Wüste in der Inneren Mongolei (China), als Teil der gleichnamigen Trockenregionen Nordwestchinas, ist aufgrund der Ausgestaltung ihrer landschaftsprägenden Elemente sowie ihrer Landschaftsdynamik, im Zusammenhang mit der Lage zum Tibet-Plateau, in den Fokus der klimageschichtlichen Grundlagenforschung gerückt. Als großes Langzeitarchiv unterschiedlichster fluvialer, lakustriner und äolischer Sedimente stellt sie eine bedeutende Lokalität zur Rekonstruktion von lokalen und regionalen Stoffflüssen dar.. Andererseits ist die Gobi-Wüste zugleich auch eine bedeutende Quelle für den überregionalen Staubtransport, da sie aufgrund der klimatischen Bedingungen insbesondere der Erosion durch Ausblasung preisgegeben wird. Vor diesem Hintergrund erfolgten zwischen 2011 und 2014, im Rahmen des BMBF-Verbundprogramms WTZ Zentralasien – Monsundynamik & Geoökosysteme (Förderkennzeichen 03G0814), mehrere deutsch-chinesische Expeditionen in das Ejina-Becken (Innere Mongolei) und das Qilian Shan-Vorland. Im Zuge dieser Expeditionen wurden für eine Bestimmung potenzieller Sedimentquellen erstmals zahlreiche Oberflächenproben aus dem gesamten Einzugsgebiet des Heihe (schwarzer Fluss) gesammelt. Zudem wurden mit zwei Bohrungen im inneren des Ejina-Beckens, ergänzende Sedimentbohrkerne zum bestehenden Bohrkern D100 (siehe Wünnemann (2005)) abgeteuft, um weit reichende, ergänzende Informationen zur Landschaftsgeschichte und zum überregionalen Sedimenttransfer zu erhalten. Gegenstand und Ziel der vorliegenden Doktorarbeit ist die sedimentologisch-mineralogische Charakterisierung des Untersuchungsgebietes in Bezug auf potenzielle Sedimentquellen und Stoffflüsse des Ejina-Beckens sowie die Rekonstruktion der Ablagerungsgeschichte eines dort erbohrten, 19m langen Sedimentbohrkerns (GN100). Schwerpunkt ist hierbei die Klärung der Sedimentherkunft innerhalb des Bohrkerns sowie die Ausweisung von Herkunftssignalen und möglichen Sedimentquellen bzw. Sedimenttransportpfaden. Die methodische Herangehensweise basiert auf einem Multi-Proxy-Ansatz zur Charakterisierung der klastischen Sedimentfazies anhand von Geländebeobachtungen, lithologisch-granulometrischen und mineralogisch-geochemischen Analysen sowie statistischen Verfahren. Für die mineralogischen Untersuchungen der Sedimente wurde eine neue, rasterelektronenmikroskopische Methode zur automatisierten Partikelanalyse genutzt und den traditionellen Methoden gegenübergestellt. Die synoptische Betrachtung der granulometrischen, geochemischen und mineralogischen Befunde der Oberflächensedimente ergibt für das Untersuchungsgebiet ein logisches Kaskadenmodell mit immer wiederkehrenden Prozessbereichen und ähnlichen Prozesssignalen. Die umfangreichen granulometrischen Analysen deuten dabei auf abnehmende Korngrößen mit zunehmender Entfernung vom Qilian Shan hin und ermöglichen die Identifizierung von vier texturellen Signalen: den fluvialen Sanden, den Dünensanden, den Stillwassersedimenten und Stäuben. Diese Ergebnisse können als Interpretationsgrundlage für die Korngrößenanalysen des Bohrkerns genutzt werden. Somit ist es möglich, die Ablagerungsgeschichte der Bohrkernsedimente zu rekonstruieren und in Verbindung mit eigenen und literaturbasierten Datierungen in einen Gesamtkontext einzuhängen. Für das Untersuchungsgebiet werden somit vier Ablagerungsphasen ausgewiesen, die bis in die Zeit des letzten glazialen Maximums (LGM) zurückreichen. Während dieser Ablagerungsphasen kam es im Zuge unterschiedlicher Aktivitäts- und Stabilitätsphasen zu einer kontinuierlichen Progradation und Überprägung des Schwemmfächers. Eine besonders aktive Phase kann zwischen 8 ka und 4 ka BP festgestellt werden, während der es aufgrund zunehmender fluvialer Aktivitäten zu einer deutlich verstärkten Schwemmfächerdynamik gekommen zu sein scheint. In den Abschnitten davor und danach waren es vor allem äolische Prozesse, die zu einer Überprägung des Schwemmfächers geführt haben. Hinsichtlich der mineralogischen Herkunftssignale gibt es eine große Variabilität. Dies spiegelt die enorme Heterogenität der Geologie des Untersuchungsgebietes wider, wodurch die räumlichen Signale nicht sehr stark ausgeprägt sind. Dennoch, können für das Einzugsgebiet drei größere Bereiche deklariert werden, die als Herkunftsgebiet in Frage kommen. Das östliche Qilian Shan Vorland zeichnet sich dabei durch deutlich höhere Chloritgehalte als primäre Quelle für die Sedimente im Ejina-Becken aus. Sie unterscheiden sich insbesondere durch stark divergierende Chloritgehalte in der Tonmineral- und Gesamtmineralfraktion, was das östliche Qilian Shan Vorland als primäre Quelle für die Sedimente im Ejina-Becken auszeichnet. Dies steht in Zusammenhang mit den Grünschiefern, Ophioliten und Serpentiniten in diesem Bereich. Geochemisch deutet vor allem das Cr/Rb-Verhältnis eine große Variabilität innerhalb des Einzugsgebietes an. Auch hier ist es das östliche Vorland, welches aufgrund seines hohen Anteils an mafischen Gesteinen reich an Chromiten und Spinellen ist und sich somit vom restlichen Untersuchungsgebiet abhebt. Die zeitliche aber auch die generelle Variabilität der Sedimentherkunft lässt sich in den Bohrkernsedimenten nicht so deutlich nachzeichnen. Die mineralogisch-sedimentologischen Eigenschaften der erbohrten klastischen Sedimente zeugen zwar von zwischenzeitlichen Änderungen bei der Sedimentherkunft, diese sind jedoch nicht so deutlich ausgeprägt, wie es die Quellsignale in den Oberflächensedimenten vermuten lassen. Ein Grund dafür scheint die starke Vermischung unterschiedlichster Sedimente während des Transportes zu sein. Die Kombination der Korngrößenergebnisse mit den Befunden der Gesamt- und Schwermineralogie deuten darauf hin, dass es zwischenzeitlich eine Phase mit überwiegend äolischen Prozessen gegeben hat, die mit einem Sedimenteintrag aus dem westlichen Bei Shan in Verbindung stehen. Neben der Zunahme ultrastabiler Schwerminerale wie Zirkon und Granat und der Abnahme opaker Schwerminerale, weisen vor allem die heutigen Verhältnisse darauf hin. Der Vergleich der traditionellen Schwermineralanalyse mit der Computer-Controlled-Scanning-Electron-Microscopy (kurz: CCSEM), die eine automatisierte Partikelauswertung der Proben ermöglicht, zeigt den deutlichen Vorteil der modernen Analysemethode. Neben einem zeitlichen Vorteil, den man durch die automatisierte Abarbeitung der vorbereiteten Proben erlangen kann, steht vor allem die deutlich größere statistische Signifikanz des Ergebnisses im Vordergrund. Zudem können mit dieser Methode auch chemische Varietäten einiger Schwerminerale bestimmt werden, die eine noch feinere Klassifizierung und sicherere Aussagen zu einer möglichen Sedimentherkunft ermöglichen. Damit ergeben sich außerdem verbesserte Aussagen zu Zusammensetzungen und Entstehungsprozessen der abgelagerten Sedimente. Die Studie verdeutlicht, dass die Sedimentherkunft innerhalb des Untersuchungsgebietes sowie die ablaufenden Prozesse zum Teil stark von lokalen Gegebenheiten abhängen. Die Heterogenität der Geologie und die Größe des Einzugsgebietes sowie die daraus resultierende Komplexität der Sedimentgenese, machen exakte Zuordnungen zu klar definierten Sedimentquellen sehr schwer. Dennoch zeigen die Ergebnisse, dass die Sedimentzufuhr in das Ejina-Becken in erster Linie durch fluviale klastische Sedimente des Heihe aus dem Qilian Shan erfolgt sein muss. Die Untersuchungsergebnisse zeigen jedoch ebenso die Notwendigkeit einer ergänzenden Bearbeitung angrenzender Untersuchungsgebiete, wie beispielsweise den Gobi-Altai im Norden oder den Beishan im Westen, sowie die Verdichtung der Oberflächenbeprobung zur feineren Auflösung von lokalen Sedimentquellen.
The electronic charge distributions of transition metal complexes fundamentally determine their chemical reactivity. Experimental access to the local valence electronic structure is therefore crucial in order to determine how frontier orbitals are delocalized between different atomic sites and electronic charge is spread throughout the transition metal complex. To that end, X-ray spectroscopies are employed in this thesis to study a series of solution-phase iron complexes with respect to the response of their local electronic charge distributions to different external influences. Using resonant inelastic X-ray scattering (RIXS) and X-ray absorption spectroscopy (XAS) at the iron L-edge, changes in local charge densities are investigated at the iron center depending on different ligand cages as well as solvent environments. A varying degree of charge delocalization from the metal center onto the ligands is observed, which is governed by the capabilities of the ligands to accept charge density into their unoccupied orbitals. Specific solvents are furthermore shown to amplify this process. Solvent molecules of strong Lewis-acids withdraw charge from the ligand allowing in turn for more metal charge to be delocalized onto the ligand. The resulting local charge deficiencies at the metal center are, however, counteracted by competing electron-donation channels from the ligand towards the iron, which are additionally revealed. This is interpreted as a compensating effect which strives to maintain local charge densities at the iron center. This mechanism of charge density preservation is found to be of general nature. Using time-resolved RIXS and XAS at the iron L-edge, an analogous interplay of electron donation and back-donation channels is also revealed for the case of charge-transfer excited states. In such transient configurations, the electronic occupation of iron-centered frontier orbitals has been altered by an optical excitation. Changes in local charge densities that are expected to follow an increased or decreased population of iron-centered orbitals are, however, again counteracted. By scaling the degree of electron donation from the ligand onto the metal, local charge densities at the iron center can be efficiently maintained. Since charge-transfer excitations, however, often constitute the initial step in many electron transfer processes, these findings challenge common notions of charge-separation in transition metal dyes.
Kohärenz und Kreativität
(2020)
Die Entwicklung einer Theorie zur schulischen Inklusion ist das zentrale Thema der Dissertation. Die Autorin nutzt empirische Analysen zur Umsetzung inklusiven Lernens sowie Daten zu sonderpädagogischen Förderschwerpunkten an inklusiven Grundschulen für die Erarbeitung von Bedingungen und Formen eines inklusiven Schulsystems. Empirische Daten zur Umsetzung inklusiver Bildung liegen aus vielen Bundesländern vor, es fehlte jedoch eine forschungsleitende Theorie zur Einordnung und Analyse der Daten. Jennifer Lambrecht hat diese Theorie auf Grundlage der Systemtheorie Luhmanns entwickelt. Sie differenziert zwischen Schulsystemen und verortet unterschiedliche Inklusionsverständnisse. Im Ergebnis entwickelt sie fünf Thesen zur schulischen Inklusion im allgemeinen Schulsystem und im Sonderschulsystem. Die Dissertation, die ein hochaktuelles Thema der empirischen Bildungsforschung behandelt, regt zum Mit- und Nachdenken an und generiert neue, interessante Forschungsfragen.
The metabolic state of an organism reflects the entire phenotype that is jointly affected by genetic and environmental changes. Due to the complexity of metabolism, system-level modelling approaches have become indispensable tools to obtain new insights into biological functions. In particular, simulation and analysis of metabolic networks using constraint-based modelling approaches have helped the analysis of metabolic fluxes. However, despite ongoing improvements in prediction of reaction flux through a system, approaches to directly predict metabolite concentrations from large-scale metabolic networks remain elusive. In this thesis, we present a computational approach for inferring concentration ranges from genome-scale metabolic models endowed with mass action kinetics. The findings specify a molecular mechanism underling facile control of concentration ranges for components in large-scale metabolic networks. Most importantly, an extended version of the approach can be used to predict concentration ranges without knowledge of kinetic parameters, provided measurements of concentrations in a reference state. We show that the approach is applicable with large-scale kinetic and stoichiometric metabolic models of organisms from different kingdoms of life. By challenging the predictions of concentration ranges in the genome-scale metabolic network of Escherichia coli with real-world data sets, we further demonstrate the prediction power and limitations of the approach. To predict concentration ranges in other species, e.g. model plant species Arabidopsis thaliana, we would rely on estimates of kinetic parameters (i.e. enzyme catalytic rates) since plant-specific enzyme catalytic rates are poorly documented. Using the constraint-based approach of Davidi et al. for estimation of enzyme catalytic rates, we obtain values for 168 plant enzymes. The approach depends on quantitative proteomics data and flux estimates obtained from constraint-based model of plant leaf metabolism integrating maximal rates of selected enzymes, plant-specific constraints on fluxes through canonical pathways, and growth measurements from Arabidopsis thaliana rosette under ten conditions. We demonstrate a low degree of plant enzyme saturation, supported by the agreement between concentrations of nicotinamide adenine dinucleotide, adenosine triphosphate, and glyceraldehyde 3-phosphate, based on our maximal in vivo catalytic rates, and available quantitative metabolomics data. Hence, our results show genome-wide estimation for plant-specific enzyme catalytic rates is feasible. These can now be readily employed to study resource allocation, to predict enzyme and metabolite concentrations using recent constrained-based modelling approaches. Constraint-based methods do not directly account for kinetic mechanisms and corresponding parameters. Therefore, a number of workflows have already been proposed to approximate reaction kinetics and to parameterize genome-scale kinetic models. We present a systems biology strategy to build a fully parameterized large-scale model of Chlamydomonas reinhardtii accounting for microcompartmentalization in the chloroplast stroma. Eukaryotic algae comprise a microcompartment, the pyrenoid, essential for the carbon concentrating mechanism (CCM) that improves their photosynthetic performance. Since the experimental study of the effects of microcompartmentation on metabolic pathways is challenging, we employ our model to investigate compartmentation of fluxes through the Calvin-Benson cycle between pyrenoid and stroma. Our model predicts that ribulose-1,5-bisphosphate, the substrate of Rubisco, and 3-phosphoglycerate, its product, diffuse in and out of the pyrenoid. We also find that there is no major diffusional barrier to metabolic flux between the pyrenoid and stroma. Therefore, our computational approach represents a stepping stone towards understanding of microcompartmentalized CCM in other organisms. This thesis provides novel strategies to use genome-scale metabolic networks to predict and integrate metabolite concentrations. Therefore, the presented approaches represent an important step in broadening the applicability of large-scale metabolic models to a range of biotechnological and medical applications.
Negotiations have become a central aspect of managerial life and influence a company’s profit significantly. This is why organizations generally endeavor to increase their negotiation performance. Over the last decades, besides other factors, research found goal setting to be one of the best predictor of negotiation outcomes. Given the extent and complexity of multi-issue business negotiations, profit optimizing by means of improving a company’s goal setting has a great deal of potential. However, developing goal setting strategies before the actual negotiation is still rather uncommon in business practice. In order to provide professionals with empirical guidance, this work aims at investigating three steps for the development and effective management of goal setting strategies for business negotiations. Therefore, this dissertation contains three papers, each one dealing with one specific step. The first paper explores the characterization of social and economic outcomes in different business relationship types at the beginning of the relationship and the development of these outcomes toward the actual status quo. The second paper takes the number of goals into account for goal setting strategies. This paper uses the two dimensions goal scope and goal difficulty to investigate the relevance and potentials of combining different level of these dimensions in multi-issue negotiations. Therefore, a large experiment was conducted measuring the impact on individual and joint negotiation outcomes, and the impasse rate. The third paper analyzes the type and orientation of negotiation goals. When the set of negotiation issues has an integrative potential, the opportunity to increase the joint gains arises. To what extent negotiators pursue the integrative potential depends largely on their goal orientation. A quantitative analysis with practitioners was used to examine the influence that business negotiations’ situative and organizational factors have on the negotiators’ goal orientation. The dissertation closes with implications for practice, limitations of the work, and ideas for future research.
Die Kooperation von Schule und Jugendhilfe befindet sich aktuell im Wandel. Spätestens seit Beginn der 2000er-Jahre wird insbesondere von Seiten der Politik eine verstärkte Zusammenarbeit beider Institutionen gefordert. Die PISA-Studie des Jahres 2000 verdeutlichte die Chancenungleichheit unseres Bildungssystems und sorgte damit für eine Renaissance der Thematik. Zuletzt führten die Inklusionsdebatte und die Flüchtlingsströme, die Europa seit 2015 erreichen, sowie daraus folgende rechtspopulistische Tendenzen in Deutschland verstärkt zur Notwendigkeit, die Bildungswelten Jugendhilfe und Schule stärker zu vernetzen. Junge Menschen unterschiedlichster Personengruppen sollen besser ins Bildungssystem integriert und demokratiefeindlichem Gedankengut entgegengewirkt werden.
Die Zusammenarbeit von Jugendhilfe und Schule ist somit aktuell stärker gefragt denn je. Sie gilt als komplexe Problemlösestrategie und wird mit einer Vielzahl positiver Erwartungen assoziiert. Sie soll auf bildungs- und sozialpolitische Fragen Antwort geben, den demokratischen Gedanken stärken und junge Menschen auf rasche technische und mediale Veränderungen im Arbeitsalltag vorbereiten. In der Theorie wird die Zusammenarbeit von Jugendhilfe und Schule als Allheilmittel angepriesen, doch wie gestaltet sich die Praxis?
Diese Studie geht dieser Frage nach, indem sie exemplarisch die Kooperation an der Bildungsstätte „Kurt Löwenstein“ im brandenburgischen Werneuchen aus der Sicht von Lehrkräften untersucht. Die Autorin wertet Leitfadeninterviews systematisch aus und kommt dabei zu überraschenden Ergebnissen. Die Studie legt Erfolgsfaktoren und Hemmnisse der Kooperation dar und liefert eine kritische und differenzierte Analyse des Ist-Zustandes.
Socializing Development
(2020)
Cybergrooming, die Anbahnung des sexuellen Missbrauchs eines Kindes über Soziale Medien und Onlinespiele, gilt als eines der schwerwiegendsten digitalen Risiken für Kinder. Für viele Kinder gehört es dabei zur Normalität in einer digitalisierten Welt aufzuwachsen und ihre Zeit in Sozialen Medien und Onlinespielen zu verbringen. In diesen Programmen spielen und kommunizieren die Kinder ganz selbstverständlich auch mit unbekannten Erwachsenen und anderen Minderjährigen. Hieraus können für die Kinder eine Vielzahl von Risiken entstehen. Eines der vermutlich relevantesten ist dabei die Gefahr, dass das Kind Opfer eines Sexualdelikts wird. Wie effektiv sind aber gegenwärtig die gesellschaftlichen und vor allem kriminalpolitischen Maßnahmen, um Kinder vor solchen Risiken in einem globalisierten digitalen Raum zu schützen? Dieses Buch setzt sich daher grundlegend mit dem Phänomen des Cybergroomings und seiner gesellschaftlichen Bekämpfungsstrategien auseinander. Neben einer umfangreichen Darstellung der Phänomenologie, der Täter- und Opferstruktur sowie der Ursachen für normenabweichendes Verhalten im digitalen Raum aus Sicht der Cyberkriminologie, liegt ein Schwerpunkt der Arbeit auf der strafrechtlichen Einordnung von Cybergrooming in Deutschland. Im Zentrum dieser juristischen Betrachtung steht die aktuelle Auseinandersetzung über die Auswirkungen der Einführung einer Versuchsstrafbarkeit für § 176 Abs. 4 Nr. 3 StGB. Die vorliegende Publikation versteht sich als eine intradisziplinäre Arbeit, die Erkenntnisse aus den Bereichen der Rechtswissenschaft, der Cyberkriminologie und der Medienwissenschaften kombiniert, um einen möglichst ganzheitlichen Blick auf das Phänomen Cybergrooming zu gewinnen. Im Ergebnis werden kriminalpolitische Handlungsempfehlungen abgeleitet, die in der Gesamtheit die Keimzelle einer digitalen Generalprävention bilden könnten.
Obwohl die Herrschaft Lindow-Ruppin im Spätmittelalter eine zentrale Lage zwischen den großen Landesherrschaften im Osten des Reiches einnahm und sich ihre beiden Landesteile über eine weite Entfernung erstreckten, ist sie weitgehend in Vergessenheit geraten. Lediglich die Frage nach der Herrschaftsgründung der aus dem nordöstlichen Harzraum stammenden Arnsteiner im Land Ruppin gab Historikern Anlass zur Beschäftigung mit dem Thema. Eine differenzierte Erforschung blieb bisher hingegen aus.
Anhand teils neu entdeckter Quellen untersucht André Stellmacher verschiedene Schwerpunkte, wie die Heirats- und Erwerbspolitik, die Besitzverteilung innerhalb der Herrschaft und das Verhältnis der Grafen zu ihren Vasallen. Eine beinahe 1.000 Einträge umfassende Regestensammlung bildet dafür die Grundlage. Neu geschaffene Karten und der reich bebilderte anhängende Siegelkatalog belegen die Ergebnisse auf anschauliche Weise.
Mit dieser Arbeit soll ein Vorschlag unterbreitet werden, wie gerichtliche Entscheidungen analysiert und bewertet werden können. Im Mittelpunkt der Arbeit steht dabei die von Karl Larenz aufgeworfene Fragestellung, unter welchen Voraussetzungen eine richterliche Rechtsfortbildung als gelungen bezeichnet werden kann. Geht man in diesem Zusammenhang von der grundsätzlichen Annahme aus, dass sich die Auslegung und Rechtsfortbildung trennen lassen, werden für diese Arbeit im wesentlichen drei Dinge relevant: Zum einen stellt sich die Frage wie Richterrecht auszulegen ist, da nur bei Klärung des konkreten Inhalts einer Entscheidung ein qualitatives Urteil ermöglicht wird. Sodann stellt sich die Frage, wie die Kriterien zu entwickeln sind. Dabei schlägt diese Arbeit Wege vor, bestehende Kriterien zu untermauern und zu präzisieren und neue Maßstäbe selbst zu entwickeln. Eine Anwendung der entwickelten Kriterien soll zum Abschluss anhand der Delisting-Rechtsprechung des BGH erfolgen.
Addressing both scholars of international law and political science as well as decision makers involved in cybersecurity policy, the book tackles the most important and intricate legal issues that a state faces when considering a reaction to a malicious cyber operation conducted by an adversarial state. While often invoked in political debates and widely analysed in international legal scholarship, self-defence and countermeasures will often remain unavailable to states in situations of cyber emergency due to the pervasive problem of reliable and timely attribution of cyber operations to state actors. Analysing the legal questions surrounding attribution in detail, the book presents the necessity defence as an evidently available alternative. However, the shortcomings of the doctrine as based in customary international law that render it problematic as a remedy for states are examined in-depth. In light of this, the book concludes by outlining a special emergency regime for cyberspace.
Die Umsatzbesteuerung staatlichen Handelns scheint widersinnig. Zum Schutz des freien Wettbewerbs kann dies jedoch geboten sein. Die steuerliche Definition des Wettbewerbsbegriffes, des Marktes sowie der wirtschaftlichen Tätigkeit führt dazu, dass staatliches und privates Handeln konsequent anhand des Wettbewerbskriteriums getrennt werden müssen. Für die Frage der Steuerbarkeit ist dann nicht mehr entscheidend, ob der Staat in Rechtsform einer GmbH als juristische Person des Privatrechts oder als juristische Person des öffentlichen Rechts gehandelt hat. Das in dieser Arbeit entwickelte Verständnis des Wettbewerbsbegriffs zeigt auch die Schwächen des neuen §2b Umsatzsteuergesetz auf und macht einen Rückgriff auf das Europarecht weiterhin zwingend notwendig.
Hugo Greßmann (1877-1927) hat als einer der führenden Vertreter der Religionsgeschichtlichen Schule die religionsgeschichtliche Methode zur Geltung gebracht. Die biographisch-wissenschaftsgeschichtliche Studie stellt Greßmanns religionsgeschichtliches Programm dar, ordnet es in den wissenschaftshistorischen Kontext ein und zeigt seine Bedeutung für die weitere Wissenschaftsgeschichte auf.
Organizing immigration
(2020)
Immigration constitutes a dynamic policy field with – often quite unpredictable – dynamics. This is based on immigration constituting a ‘wicked problem’ meaning that it is characterized by uncertainty, ambiguity and complexity. Due to the dynamics in the policy field, expectations towards public administrations often change. Following neo-institutionalist theory, public administrations depend on meeting the expectations in the organizational field in order to maintain legitimacy as the basis for, e.g., resources and compliance of stakeholders. With the dynamics in the policy field, expectations might change and public administrations consequently need to adapt in order to maintain or repair the then threatened legitimacy. If their organizational legitimacy is threatened by a perception of structures and processes being inadequate for changed expectations, an ‘institutional crisis’ unfolds. However, we know little about ministerial bureaucracies’ structural reactions to such crucial momentums and how this effects the quest for coordination within policy-making. Overall, the dissertation thus links to both policy analysis and public administration research and consists of five publications. It asks: How do structures in ministerial bureaucracies change in the context of institutional crises? And what effect do these changes have on ministerial coordination? The dissertation hereby focusses on the above described dynamic policy field of immigration in Germany in the period from 2005 to 2017 and pursues three objectives: 1) to identify the context and impulse for changes in the structures of ministerial bureaucracies, 2) to describe respective changes with regard to their organizational structures, and 3) to identify their effect on coordination. It hereby compares and contrasts institutional crises by incremental change and shock as well as changes and effects at federal and Länder level which allows a comprehensive answer to both of the research questions. Theoretically, the dissertation follows neo-institutionalist theory with a particular focus on changes in organizational structures, coordination and crisis management. Methodologically, it follows a comparative design. Each article (except for the literature review), focusses on ministerial bureaucracies at one governmental level (federal or Länder) and on an institutional crisis induced by either an incremental process or a shock. Thus, responses and effects can be compared and contrasted across impulses for institutional crises and governmental levels. Overall, the dissertation follows a mixed methods approach with a majority of qualitative single and small-n case studies based on document analysis and semi-structured interviews. Additionally, two articles use quantitative methods as they best suited the respective research question. The rather explorative nature of these two articles however fits to the overall interpretivist approach of the dissertation. Overall, the dissertation’s core argument is: Within the investigation period, varying dynamics and thus impulses for institutional crises took place in the German policy field of immigration. Respectively, expectations by stakeholders on how the politico-administrative system should address the policy problem changed. Ministerial administrations at both the federal and Länder level adapted to these expectations in order to maintain, or regain respectively, organizational legitimacy. The administration hereby referred to well-known recipes of structural changes. Institutional crises do not constitute fields of experimentation. The new structures had an immediate effect on ministerial coordination, with respect to both the horizontal and vertical dimension. Yet, they did not mean a comprehensive change of the system in place. The dissertation thus challenges the idea of the toppling effect of crises and rather shows that adaptability and persistence of public administrations constitute two sides of the same coin.
Hugo Greßmann (1877-1927) hat als einer der führenden Vertreter der Religionsgeschichtlichen Schule die religionsgeschichtliche Methode zur Geltung gebracht. Die biographisch-wissenschaftsgeschichtliche Studie stellt Greßmanns religionsgeschichtliches Programm dar, ordnet es in den wissenschaftshistorischen Kontext ein und zeigt seine Bedeutung für die weitere Wissenschaftsgeschichte auf.
Die wirtschaftliche Intensivierung des Profisports hat in den vergangenen Jahrzehnten zu einer Anpassung der Organisationsstrukturen des Sports geführt. Immer wieder wird hierbei die Frage aufgeworfen, inwiefern eine identitätsstiftende Rückkoppelung des Sports an seine Basis gewährleistet werden kann. In der Rechtspraxis steht hier die basisdemokratische Ausrichtung der im Sport vorherrschenden Rechtsform des eingetragenen Vereins im Spannungsverhältnis zu der Ausgliederung wirtschaftlicher Betätigung auf Kapitalgesellschaften.
Der Autor untersucht in diesem Kontext, inwiefern sich die Rechtsform der eingetragenen Genossenschaft als Rechtsform für den Sport eignet. Hierbei nimmer er Bezug auf die rechtliche Zulässigkeit, die Organisations- und Finanzverfassung, das mit der Rechtsform einhergehende genossenschaftliche Prüfwesen sowie die steuerrechtlichen Auswirkungen, und entwickelt konkrete Einsatzmöglichkeiten der eingetragenen Genossenschaft in der Organisationspyramide des Sports.
Wege zur Gesangskarriere
(2020)
Hybride Gestaltungen gehören zu den wichtigsten Aufbauelementen von grenzüberschreitenden Steuergestaltungsmodellen und sind eines der komplexesten Themen des Internationalen Steuerrechts. Mit der Anti Tax Avoidance Directive (ATAD) hat der Unionsgesetzgeber den Mitgliedstaaten die rechtliche Verpflichtung auferlegt, die mit hybriden Gestaltungen einhergehenden Besteuerungsinkongruenzen durch Korrespondenzregelungen zu neutralisieren.
Das Werk durchdringt die einschlägigen Richtlinienvorschriften grundlegend und greift dabei die OECD-Regelungsempfehlungen zu BEPS-Aktionspunkt 2 auf. Dabei werden bedeutsame Divergenzen aufgezeigt und Zweifelsfragen diskutiert. Die Vorarbeiten dienen als Beurteilungsrahmen für den nachfolgend durchgeführten Abgleich mit dem deutschen Rechtsrahmen. Auf dieser Grundlage wird der verbleibende gesetzgeberische Umsetzungsbedarf identifiziert. Zum Abschluss wird der Entwurf des ATAD-Umsetzungsgesetzes kritisch gewürdigt.
Die Reformation in Brandenburg gilt als Musterbeispiel einer obrigkeitlich initiierten und gesteuerten Fürstenreformation in einem nordostdeutschen Territorialstaat. Deshalb haben lange Zeit das Handeln und die Motive hauptsächlich der Landesherrschaft die Aufmerksamkeit der brandenburgischen Reformationsgeschichtsforschung auf sich vereinigt. Felix Engel erweitert diesen recht eng gesteckten Horizont, indem er die Perspektive »von unten« in seine Betrachtung einbezieht und systematisch ergründet, welche Mittel und Wege den städtischen Akteuren zu verschiedenen Phasen des Reformationsprozesses offenstanden, um die Umgestaltung ihrer kommunalen Kirchenwesen aktiv zu beeinflussen. Daher finden zunächst sowohl die strukturellen und ideellen Vorbedingungen als auch die Reformationsverläufe Berücksichtigung. Anschließend werden Kontinuitäten und Brüche sowie die Handlungsspielräume der beteiligten Protagonisten in zentralen Bereichen der städtischen Kirchenwesen analysiert.