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Der Untersuchungsgegenstand der vorliegenden Arbeit ist die Praxis der Europäischen Bürgerinitiative (EBI) nach Art. 11 Abs. 4 EUV, dem weltweit ersten und einzigen Instrument transnationaler, partizipativer und digitaler Demokratie. Im Mittelpunkt der Untersuchung steht die Frage, welchen Beitrag die EBI zur weiteren Demokratisierung der EU leisten kann und auf welche Art und Weise insoweit noch weitere Verbesserungen erzielt werden können. Nach zehnjähriger Anwendungspraxis von 2012 bis 2022 liegen inzwischen ausreichend empirische Daten vor, um den Forschungsgegenstand umfassend zu erforschen und das Instrument mit Blick auf seinen von den EU-Institutionen versprochenen Legitimations- und Demokratisierungsbeitrag bewerten zu können. Insbesondere wird das EBI-Verfahren in dieser Arbeit auf seine empirisch nachweisbare Nutzung, auf seine prozedurale Nutzerfreundlichkeit sowie auf seine politische wie rechtliche Wirkmächtigkeit untersucht. Zum Zwecke der korrekten Kategorisierung, Bewertung sowie der nutzerfreundlichen Ausgestaltung des EBI-Verfahrens werden Vergleiche mit Bürger- und Volksinitiativverfahren in den EU-Mitgliedstaaten sowie mit Bürgerbeteiligungsverfahren auf EU-Ebene vorgenommen. Den empirischen und komparativen Analysen werden eine historische Analyse über die Genese der EBI seit dem EU-Verfassungskonvent sowie theoretisch-normative Überlegungen und praktische Untersuchungen zu unterschiedlichen beteiligungszentrierten Demokratiemodellen vorangestellt, um die EBI einzuordnen und die Steigerungsmöglichkeiten ihres Demokratisierungsbeitrags zu erschließen. Letzteres zielt schließlich auf die Frage nach der prozeduralen Kombination und Kompatibilität der EBI mit demokratischen Innovationen aus dem Bereich der deliberativen und direkten Demokratie ab. Die Arbeit schließt mit einem Ausblick und unterbreitet umfassende EBI-Reformoptionen sowohl auf der primär- und sekundärrechtlichen als auch auf der informellen Ebene.
The digitization has permeated almost all aspects of an individual’s life. In the work context as well as in the private sphere, one readily encounters and relies on Information and Communication Technologies (ICTs), such as Social Networking Sites (SNS), smartphones and so forth. By communicating with as well as obtaining information via such technologies, ICTs engage one’s mind as interaction happens. This interaction of ICTs and the human mind form the focal topic of this thesis. Within this thesis, the human mind is represented on behalf of a facilitated model comprising a perceptual, a cognitive and a motor subsystem. ICTs represent an external stimulus, which triggers the human mind's perceptual subsystem, the cognitive subsystem and eventually leads to a motoric response via the motor subsystem. The external stimulus causing this event chain is within this thesis an ICT. The digital environment and related ICTs are high attention environments offering large and easily accessible amounts of information. Not surprisingly, issues may arise, when the human mind deals with ICTs. Thus, the interplay between ICTs and the human mind entails downsides. This thesis investigates these downsides and in addition the ICT-based factors that cause these downsides. More specifically, the thesis investigates these two aspects as research questions in the context of SNSs as well as other ICTs (such as smartphones, e-learning etc.). Addressing the research questions, 8 articles are submitted within this thesis which address the topic with different methodologies, including quantitative, qualitative, mixed methods as well as systematic literature reviews. Article 1 investigates factors that lead to SNS fatigue and discontinuance intentions in a mixed-methods design. Article 2 explores if certain factors encountered on a newsfeed hamper sensemaking. Article 3 proposes a study design to explore the link between disorderly perceptions of a SNSs newsfeed and gender stereotype activations. Article 4 considers the interplay between users and algorithms via the newsfeed interface and the implications for relevance perceptions. Article 5 explores information acquisition, hampering factors and verification strategies of social media users. Article 6 systematically reviews addiction scales of various ICTs. Article 7 investigates click behavior in e-learning contexts and how this is linked to cultural and personality traits. Finally, article 8 offers a comprehensive overview of the antecedents and consequences of children’s smartphone usage. Within the specific context of SNSs, the thesis suggests that the cognitive tolls imposed on users’ minds cause adverse effects, such as impaired sensemaking, fatigue, stereotype activation as well as intentions to discontinue the service. Other ICTs lead to addiction, and i.e., smartphones evidence to cause cognitive impairments in children. Factors on the ICT side that promote these adverse effects are linked to specific features, such as the newsfeed for SNSs and entail overload or perceptions of disorder. The thesis adds theoretically to the understanding of downsides that arise from the interplay between human minds and ICTs. Especially, the context of SNSs is spotlighted and insights add to the growing body of literature on experiences and perceptions. For instance, one study’s result suggests that considering information organization is as important as merely decreasing overload perceptions from the users in countering adverse effects of SNS usage. Practically, the thesis emphasizes the importance of mindful interaction with ICTs. Future research is welcome to build on the exploratory investigations and may draw an even more holistic picture to enhance the interaction between ICTs and the human mind.
Potato FLC-like and SVP-like proteins jointly control growth and distinct developmental processes
(2023)
Based on worldwide consumption, Solanum tuberosum L. (potato) is the most important non-grain food crop. Potato has two ways of stable propagation: sexually via flowering and vegetatively via tuberization. Remarkably, these two developmental processes are controlled by similar molecular regulators and mechanisms. Given that FLC and SVP genes act as key flowering regulators in the model species Arabidopsis and in various other crop species, this study aimed at identifying FLC and SVP homologs in potato and investigating their roles in the regulation of plant development, with a particular focus on flowering and tuberization. Our analysis demonstrated that there are five FLC-like and three SVP like proteins encoded in the potato genome. The expression profiles of StFLCs and StSVPs throughout potato development and the detected interactions between their proteins indicate tissue specificity of the individual genes and distinct roles of a variety of putative protein complexes. In particular, we discovered that StFLC-D, as well as StFLC-B, StSVP-A, and StSVP-B play a complex role in the regulation of flowering time, as not only increased but also decreased levels of their transcripts promote earlier flowering. Most importantly, StFLC-D has a marked impact on tuberization under non-inductive conditions and susceptibility to temperature-induced tuber malformation, also known as second growth. Plants with decreased levels of StFLC-D demonstrated a strong ability to produce tubers under long days and appeared to be insensitive to temperature-induced second growth. Lastly, our data also suggests that StFLCs and StSVPs may be involved in the nitrogen-dependent regulation of potato development. Taken together, this study highlights the functional importance of StFLC and StSVP genes in the regulation of distinct developmental processes in potato.
Negotiations are a way of joint decision-making and thereby a form of social conflict. By determining the concrete allocation of scarce resources, negotiations have a great impact on the value creation of companies. If companies succeed in achieving better negotiation results in the long term, they can increase their profitability. Ensuring a company's negotiation success is therefore an organizational issue of central importance. While the question of ensuring individual negotiation success has been the subject and topic of multidisciplinary research for a long time, the question of how organizations can implement and ensure continuous negotiation success remains largely unexplored. This dissertation therefore aims to investigate how companies enable their employees to consistently achieve better negotiation outcomes. It is significant that, in the corporate context, negotiators do not act as individuals but as embedded representatives of an organization, and that negotiations are not one-time events but recurring necessities for the existence of the organization instead. In organizations, those recurring processes with a similar fundamental structure are handled by routines. A planned improvement of routines is often forced by new artifacts. In this context, artifacts refer to human-created technologies with which humans interact within routines and therefore artifacts have a central influence on executing the routine. If negotiation activities in companies are represented by organizational routines, one central issue for improving companies’ negotiation performance is the artifacts’ incorporation into organizational negotiation routines that facilitate the efficient application of the insights from negotiation research. The dissertation consists of three studies that were written as research papers to examine artifacts in the organizational negotiation context. The first study focuses on the pre-negotiation stage and presents four tools to assist negotiation practitioners in efficiently preparing for negotiation. The study examines the negotiation preparation’s effectiveness and efficiency and the negotiation outcome in a case-based experiment. The second study is devoted to a closer examination of the barriers that inhibit the adoption of negotiation support systems (NSSs) as one kind of organizational negotiation artifact. The investigation is conducted using a structural equation model based on information from participating practitioners. The third study is concerned with the future of negotiation support system research. An exploratory study based on qualitative in-depth interviews with proven and published experts in the field aims to evaluate the current state of research. The general discussion of the dissertation connects, summarizes, and concludes the study results and derives implications for practice, limitations, and future research ideas.
Interested in the ideological workings of fiction, I study how major avant-garde tropes promote the potential of permanent renewal as white America’s property. Renewal ties to the capacities to create, progress, transcend, and simply be. From Black critique we know that, within dominant discourse, all these capacities have been denied to Black bodies ever since colonization. Black work has been fetishized, appropriated, stolen, and dismissed in and by dominant culture, while Black being is construed as negativity and barred on the level of ontology. It follows then that racialization operates on multiple levels in the conceptual frame of renewal. I study this conceptualization by re-reading the works of and criticism on progressive white authors. I examine how images of renewal enable the claim on futurity, transformative potential, and movement forward as exclusively white properties. Premised on oppositions between positive capacities and a state of complete incapacitation, these images are often viewed as separate constructions. This project shows that, deriving from white ideology, such representations are symbiotic and simultaneous - the "good" story of white renewal rests on the continual transgression towards Black being.
The musculoskeletal system provides support and enables movement to the body, and its deterioration is a crucial aspect of age-related functional decline. Mesenchymal stromal cells (MSCs) play an important role in musculoskeletal homeostasis due to their broad differentiation potentials and their ability to support osteogenic and myogenic tissue maintenance and regeneration. In the bone, MSCs differentiate either into osteochondrogenic progenitors to form osteocytes and chondrocytes, or increasingly with age into adipogenic progenitors which give rise to bone-resident adipocytes. In skeletal muscle, during healthy regeneration MSCs provide regulatory signals that activate local, tissue-specific stem cells, known as satellite cells, which regenerate contractile myofibres. This process involves a significant cross-talk to immune cells stemming from both lymphoid and myeloid lineages. During ageing, muscle-resident MSCs undergo increased adipogenic lineage commitment, causing niche changes that contribute to fatty infiltration in muscles. These shifts in cell populations in bone lead to the loss of osteogenic cells and subsequently osteoporosis, or in muscle to impaired regeneration and to the development of sarcopenia. However, the signals that drive transition of MSCs into their respective cellular fates remain elusive.
This thesis aims to elucidate the transcriptional shifts modulating cell states and cell types in musculoskeletal MSC fate determination. Single-cell RNA-sequencing (scRNA-seq) was used to characterise cell type-specific transcript regulation. State-of-the-art bioinformatics tools were combined with different analytical platforms that include both droplet-based scRNA-seq for large heterogeneous populations, and microfluidics-based scRNA-seq to assess small, rare subpopulations. For each platform, distinct computational pipelines were established including filtering steps to exclude low-quality cells, and data visualisation was performed by dimensionality reduction. Downstream analysis included clustering, cell type annotation, and differential gene expression to investigate transcriptional states in defined cell types during ageing and injury in the muscle and bone. Finally, a novel tool to assess publication activities in defined areas of research for the identified marker genes was developed.
The results in the bone indicate that ageing MSCs increasingly commit towards an adipogenic fate at the expense of osteogenic specialisation. The data also suggests that significant cell population shifts of MSC-type fibro-adipogenic progenitors during muscle ageing underlie the pathologies observed in homeostatic and post-injury regenerative conditions. High-throughput visualisation of publication activity for candidate genes enabled more effective biological evaluation of scRNA-seq data. These results expose critical age-related changes in the stem cell niches of skeletal muscle and bone, highlight their respective sensitivity to nutrition and pathology, and elucidate novel factors that modulate stem cell-based regeneration. Targeting these processes might improve musculoskeletal health in the context of ageing and prevent the negative effects of pathological lineage determination.
Teacher self-efficacy is highly relevant for effective teaching, student academic development, and teachers’ wellbeing, as theoretical work (Bandura, 1997; Tschannen-Moran et al., 1998) and empirical studies (i.e., Burić & Kim, 2020; Klassen & Chiu, 2010; van Uden et al., 2013) have shown associations with effective classroom management, student support, student motivation, and teachers’ job satisfaction. Given the importance of teacher self-efficacy for teaching and learning, it is interesting to note that existing research is limited in several aspects – first, longitudinal studies on the relations between teacher self-efficacy and student academic outcomes are widely missing; second, empirical studies often assess teacher self-efficacy as a one-dimensional construct, neglecting its multidimensional character; third, studies often only focus on either the students’ or the teachers’ perspective on teaching and thus do not include simultaneously multiple sources of information on teaching practices as a consequence of teacher self-efficacy; fourth, research often does not systematically consider the effects of teacher self-efficacy on students’ academic outcomes at both the group and individual level. Against this backdrop, this dissertation presents three longitudinal studies that aim to contribute to a more detailed perspective on teacher self-efficacy by examining systematically and longitudinally the relations between multiple dimensions of teacher self-efficacy and theoretically aligned teaching quality facets as perceived by teachers and students, as well as their relations to students’ motivational-affective outcomes – more concretely, their relations to students’ interest, enjoyment, and self-efficacy in a multi-level analysis approach. Study 1 examines the longitudinal relations between teacher self-efficacy for classroom management and student-perceived monitoring and social relatedness, and investigates whether the two student-reported teaching dimensions explain the relations between teacher self-efficacy for classroom management and student enjoyment using multi-level analyses. Study 2 examines longitudinally how teacher self-efficacy for student engagement relates to student interest through student- and teacher-perceived emotional support. Also, including student and teacher perspectives on teaching, Study 3 examines the longitudinal relations between specific facets of teacher self-efficacy for classroom management and classroom discipline, teacher self-efficacy for instructional strategies and cognitive activation, teacher self-efficacy for student engagement and competence support, teacher self-efficacy for emotional support and social relatedness, as well as teacher self-efficacy for student-oriented teaching and learning goal-oriented instruction with students’ enjoyment and self-efficacy. Furthermore, in Studies 2 and 3 the cross-level mediation effects of longitudinal relations with teacher self-efficacy on student motivational-affective characteristics via teaching practices are examined in order to address the lack of empirical studies disentangling the relations for specifically individual- vs. group-level effects. The limitations and implications are discussed in terms of their theoretical and practical relevance for school practice, teacher education, and teacher training.
The G protein-coupled estrogen receptor (GPER1) is acknowledged as an important mediator of estrogen signaling. Given the ubiquitous expression of GPER1, it is likely that the receptor plays a role in a variety of malignancies, not only in the classic hormonally regulated tissues (e.g., breast, ovary, and prostate), but also in the colon. As colorectal cancer (CRC) is the third most common cancer in both men and women worldwide and environmental factors and dietary habits are important risk factors, it is increasingly recognized that natural and synthetic hormones and their associated receptors might play a role in CRC. Through oral consumption, environmental contaminants with endocrine activity are in contact with the gastrointestinal mucosa, where they might exert their toxic effects. Although GPER1 has been shown to be engaged in physiological and pathophysiological processes, its role in CRC remains poorly understood. Thus, pro- as well as anti-tumorigenic effects are described in the literature. This thesis has uncovered novel roles of GPER1 in mediating major CRC-associated phenotypes in transformed and non-transformed colon cell lines. Exposure to the estrogens 17β-estradiol (E2), bisphenol-A (BPA) and diethylstilbestrol (DES) but also the androgen dihydrotestosterone (DHT) resulted in GPER1-dependent induction of supernumerary centrosomes, whole chromosomal instability (w-CIN) and aneuploidy. Indeed, both knockdown and inhibition of GPER1 attenuated the generation of (xeno)hormone-driven supernumerary centrosomes and karyotype instability. Mechanistically, (xeno)hormone-induced centrosome amplification was associated with transient multipolar mitosis and the generation of so called anaphase “lagging” chromosomes. The results of this thesis propose a GPER1/PKA/AKAP9-pathway in regulating centrosome numbers in colorectal cancer cells and the involvement of the centriolar protein centrin. Remarkably, exposure to (xeno)hormones resulted in atypical enlargement and unexpected phosphorylation of the centriole marker centrin in interphase. These findings provide a novel role for GPER1 in key CRC-prone lesions and shed light on underlying mechanisms that involve GPER1 function in the colon. Elucidating to what extent centrosomal proteins are involved in the GPER1-mediated aneugenic effect will be an important task for future studies. The present study was intended to lay a first foundation to understand the molecular basis and potential risk factors of CRC which might help to reduce the use of laboratory animals. Since numerous animal experiments are conducted in biomedical research, the development of alternative methods is indispensable. The Federal Institute for Risk Assessment (BfR) as the German Center for the Protection of Laboratory Animals (Bf3R) addresses this issue by uncovering underlying mechanisms leading to colorectal cancer as necessary prerequisite in order to develop alternative methods.
Krafttraining ist ein etabliertes Mittel für die Entwicklung körperlicher Fitness und sport-artspezifischer Leistungen in verschiedenen Sportarten. Dabei scheint dem Krafttraining auch im Hinblick auf den langfristigen Leistungsaufbau im Nachwuchsleistungssport Rudern eine besondere Rolle zuzukommen. Die vorliegende Arbeit widmet sich der Optimie-rung der Leistungsdiagnostik sowie der Bewertung der Effektivität von Krafttrainingsmethoden zur Verbesserung der körperlichen Fitness und der sportartspezifischen Leistung im Nachwuchsleistungsrudern.
Die erste Studie im Rahmen dieser kumulativen Arbeit beinhaltet die Analyse eines sport-artspezifischen Anforderungsprofils der Sportart Rudern. Die Studienergebnisse zeigen, dass die Energiebereitstellung im Ruderwettkampf zu einem großen Anteil aus aeroben und zu einem geringen Anteil aus anaeroben Stoffwechselprozessen erfolgt. Während der vier Phasen des rudertechnischen Leitbildes werden nahezu alle großen Muskelgruppen beansprucht. Aufgrund der hohen Trainingsumfänge auf internationalem Leistungsniveau besteht bei Ruderern ein erhöhtes Risiko, Verletzungen im lumbalen Rückensegment, den Knien sowie den Rippen zu erleiden.
Im Rahmen der zweiten Studie wurden die Effekte von Krafttraining auf die körperliche Fitness und die sportartspezifische Leistung von Ruderern unterschiedlichen Expertisen-niveaus untersucht. Die Studienergebnisse zeigen, dass signifikante kleine Effekte des Krafttrainings auf die körperliche Fitness (Maximalkraft der unteren Gliedmaßen) und auf die sportartspezifische Leistung existieren. Subgruppenanalysen für Krafttrainingstyp und Expertisenniveau zeigten nicht signifikante Unterschiede zwischen den jeweiligen Subgruppen der Ruderer.
Die dritte Studie analysierte die Zusammenhänge zwischen der biologischen Reife, der Körperkonstitution und der körperlichen Fitness mit der Leistung auf dem Ruderergometer über 700-m bei weiblichen Nachwuchseliteruderern. Die Analyse zeigte signifikante mittle-re bis hohe Zusammenhänge zwischen der biologischen Reife, Kennwerten der Körperkonstitution, der körperlichen Fitness (z. B. Maximalkraft, Kraftausdauer) und der Leistung auf dem Ruderergometer. Zusätzlich konnte gezeigt werden, dass die Prädiktoren Körperkonstitution (Magermasse) und Kraftausdauer (Bourban-Test) die Leistung des 700-m Ruderergometertest am besten abbilden.
Die vierte Studie untersuchte die Effekte von zwei unterschiedlichen Krafttrainingsmetho-den, die jeweils über neun Wochen durchgeführt wurden, auf die körperliche Fitness und die Leistung auf dem Ruderergometer bei weiblichen Elite-Nachwuchsruderern. Die Stu-dienergebnisse zeigen, dass beide Gruppen signifikante Steigerungen auf ausgewählte Komponenten der körperlichen Fitness (z. B. Maximalkraft, Schnellkraft, anaerobe Aus-dauer und Richtungswechselgeschwindigkeit) und die sportartspezifische Leistung erzielten. Signifikant größere Zuwächse resultierten nach Krafttraining mit höheren Intensitäten [HI] bei gleichem Volumen im Vergleich zu Kraftausdauertraining [KA] in ausgewählten Komponenten der körperlichen Fitness (z. B. Maximalkraft). Im Gegensatz dazu, führte KA bei gleichem Volumen im Vergleich zu HI zu größeren Steigerungen der sportartspezifischen Leistung.
Zusammenfassend zeigen die Ergebnisse, dass Krafttraining ein effektives Mittel zur Steigerung ausgewählter Komponenten der körperlichen Fitness und der sportartspezifischen Leistung in der Sportart Rudern für RuderInnen und im Speziellen für den Nachwuchssport ist. Insbesondere im Nachwuchsleistungsrudern zeigte sich, dass HI zusätzlich zum regulären Rudertraining effektiver zur Verbesserung der körperlichen Fitness (z. B. Maximalkraft) ist als KA. Zur Verbesserung der sportartspezifischen Leistung jedoch, stellte KA im Vergleich zu HI bei weiblichen Elite-Nachwuchsruderern die effektivere Krafttrainings-methode dar. Weiterhin wird Trainern im Nachwuchsrudersport empfohlen, ausgewählte Merkmale der biologischen Reife, Körperkonstitution sowie der körperlichen Fitness (Maximalkraft, Kraftausdauer) für die Talententwicklung zu berücksichtigen.
In nature, plants often encounter biotic and abiotic stresses, which can cause reduced crop yield and quality, and threaten the nutrition of a growing human population. As heat stress (HS) is one of the main abiotic stresses, and is projected to increase due to global warming, it is necessary to better understand how plants respond and survive under HS. In Arabidopsis thaliana, plants can survive under severe HS if primed by a non-lethal HS, a process called acquisition of thermotolerance. This primed stated can be maintained for several days, and the ability of plants to maintain the primed state is called maintenance of acquired thermotolerance (mATT) or HS memory. According to current research, two Heat shock factors (HSFs) HSFA2 and HSFA3 are known to account for the majority of mATT capability, and there are other HSFs e.g. HSFA1b and HSFA6b in HSF complexes containing HSFA2 and/or HSFA3, however, the roles of these HSFs in HS memory is not clearly understood. Moreover, the mechanism of these HSFs in regulating HS memory is unclear, whether transcriptional machinery e.g. the Mediator complex contributes to transcriptional memory. This work investigates the role of HSFs and Mediator subunits in HS memory in A. thaliana. For the role of HSFs, the interaction between HSFA1b and HSFA2 during HS memory phase was confirmed by in vivo co- immunoprecipitation (Co-IP). HSFA1b, HSFA2, HSFA3 and HSFA6b targeted HS memory-related genes according to DNA affinity purification sequencing (DAP-seq) data, and targets of HSFA1b were confirmed in vivo by chromatin immunoprecipitation qPCR (ChIP-qPCR). The mutant of hsfa6b showed an HS memory deficiency phenotype in mATT survival assay. These data confirmed the role for HSFA2 and HSFA3 in HS memory, and suggest that HSFA1b and HSFA6b also function in HS memory. The Mediator complex functions as an RNA Polymerase II (RNA Pol II) co-regulator, and includes Head, Middle, Tail and Kinase modules. Both MED23 and MED32 belong to the Tail module, and they have a positive role in HS memory. MED23 interacted with HSFA3, as determined by yeast two hybrid (Y2H) and in vivo Co-IP assays. The med23 mutant showed a decreased HS memory phenotype, reduced expression of Type I (sustained expression) memory genes following HS, and reduced accumulation of the memory-associated Tri-methylation of histone H3 lysine 4 (H3K4me3)histone modification at HS memory-related gene loci after HS. MED23 was recruited to HS-inducible memory and non-memory genes after HS, as determined by ChIP-qPCR. The med32
mutant showed a reduced HS memory phenotype, decreased expression of Type I and Type II (hyper-induction) memory genes, and lower accumulation of H3K4me3 at memory gene lociafter HS. However, MED32 did not show interaction with any tested HSF in Y2H or in vivo Co-IP. MED32 regulated the recruitment of RNA Pol II at HS-inducible genes after HS, but was not itself recruited to HS memory genes after HS. These results provided more evidence
that the Mediator subunits MED23 and MED32 regulate HS memory on transcriptional and epigenetic levels. In general, this work provides a better insight into the molecular mechanism of how HSFs and Mediator subunits regulate HS memory in plants and will provide new perspectives to breed crops with improved thermotolerance.
Functional materials, also called "Smart Materials", are described by their ability to fulfill a desired task through targeted interaction with its environment. Due to this functional integration, such materials are of increased interest, especially in areas where the increasing micronization of components is required. Modern manufacturing processes (e.g. microfluidics) and the availability of a wide variety of functional materials (e.g. shape memory materials) now enable the production of particle-based switching components. This category includes micropumps and microvalves, whose basic function is the active control of liquid flows. One approach in realizing those microcomponents as pursued by this work, enables variable size-switching of water-filled microballoons by implementing a stimulus-sensitive switching motif in the capsule's membrane shell, while being under the influence of a constant driving force. The switching motif with its gatekeeper function has a critical influence on one or more material parameters, which modulate the capsule's resistance against the driving force in microballoon expansion process. The advantage of this concept is that even non-variable analyte conditions, such as concentration levels of ions, can be capitalized to generate external force fields that, under the control of the membrane, cause an inflation of the microballoon by an osmotically driven water influx. In case of osmotic pressure gradients as the driving force for the capsule expansion, material parameters associated with the gatekeeper function are specifically the permeability and the mechanical stiffness of the shell material. While a modulation of the shell permeability could be utilized to kinetically impede the water influx on large time scales, a modulation of the shell's mechanical stiffness even might be utilized to completely prevent the capsule inflation due to a possible non-deformability beneath a certain threshold pressure. In polymer networks, which are a suitable material class for the demanded capsule shell because of their excellent elasticity, both the permeability and the mechanical properties are strongly influenced by the crystallinity of the material. Since the permeability is effectively reduced with increasing crystallinity, while the mechanical stiffness is simultaneously greatly increased, both effects point in the same direction in terms of their functional relationship. For this reason and due to a reversible and contactless modulation of the membrane crystallinity by heat input, crystallites may be suitable switching motifs for controlling the capsule expansion. As second design element of reversible expandable microballoons, the capsule geometry, defined by an aqueous core enveloped by the temperature-sensitive polymer network membrane, should allow an osmotic pressure gradient across the membrane layer. The strength of the inflation pressure and the associated inflation velocity upon membrane melting should be controlled by the salt concentration within the aqueous core, while a turn in the osmotic gradient should furthermore allow the reversible process of capsule deflation. Therefore, it should be possible to build either microvalves and micropumps, while their intended action of either pumping or valving is determined by their state of expansion and the direction of the osmotic pressure gradient.. Microballoons of approximately 300 µm in diameter were formed via droplet-based microfluidics from double-emulsion templates (w/o/w). The elastomeric capsule membrane was formed by photo-crosslinking of methacrylate (MA) functionalized oligo(ε-caprolactone) precursors (≈ 3.8 MA-arms, Mn ≈ 12000 g mol-1) within the organic medium layer (o) via UV-exposure after droplet-formation. After removal of the toluene/chloroform mixture by slow extraction via the continuous aqueous phase, the capsules solidified under the development of a characteristic "mushroom"-like shape at specific experimental conditions (e.g. λ = 308 nm, 57 mJ·s-1·cm-2, 16 min). It could be furthermore shown that in dependency to the process parameters: oligomer concentration and curing-time also spherical capsules were accessible. Long curing-times and high oligomer concentrations at a fixed light-intensity favored the formation of "mushroom"-like capsules, whereas the contrary led to spherical shaped capsules. A comparative study on thin polymer network films of same composition and equal treatment proved a correlation between the film's crosslink density and their contraction capability, while stronger crosslinked polymer networks showed a stronger contraction after solvent removal. In combination with observations during capsule solidification via light-microscopy, where a continuous shaping from almost spherical crosslinked templates to "mushroom"-shaped and solidified capsules was stated, the following mechanism was proposed. In case of low oligomer contents and short curing-times, the contraction of the capsule shell during solvent removal is strongly diminished due to a low degree of crosslinking. Therefore, the solidifying shell could freely collapse onto the aqueous core. In the other case, high oligomer concentrations and long curing-times will favor the formation of highly crosslinked capsule membranes with a strong contraction capability. Due to an observed decentered location of the aqueous core within the swollen polymer network, an uneven radial stress along the capsule's circumference is exerted to the incompressible core. This lead to an uneven contraction during solvent removal and a directed flow of the core fluid into the direction of the minimal stress vector. In consequence, the initially thicker spherical cap contracts, whereas the opposing thinner spherical cap get stretched. The "mushroom"-shape over some advantages over their spherical shaped counterparts, why they were selected for the further experiments. Besides the necessity of a high density of crosslinking for the purpose of extraordinary elasticity and toughness, the form-anisotropy promotes a faster microballoon expandability due to a partial reduction of the membrane thickness. Additionally, pre-stretched regions of thin thickness might provide a better resistance against inflation pressure than spherical but non-stretched capsules of equal membrane thickness. The resulting "mushroom"-shaped microcapsules exhibited a melting point of Tm ≈ 50 - 60 °C and a degree of crystallinity of Xc ≈ 29 - 38 % depending on the membrane thickness and internal salt content, which is slightly lower than for the non-crosslinked oligomer and reasoned by a limited chain mobility upon crosslinking. Nonetheless, the melting transition of the polymer network was associated with a strong drop in its mechanical stiffness, which was shown to have a strong influence on the osmotic driven expansion of the microcapsules. Capsules that were subjected to osmotic pressures between 1.5 and 4.7 MPa did not expand if the temperature was well below the melting point of the capsule's membrane, i.e. at room temperature. In contrast, a continuous expansion, while approaching asymptotically to a final capsule size, was observed if the temperature exceeded the melting point, i.e. 60 °C. Microballoons, which were kept for 56 days at ∆Π = 1.5 MPa and room temperature, did not change significantly in diameter, why the impact of the mechanical stiffness on the expansion behavior is considered to be the greater than the influence of the shell permeability. The time-resolved expansion behavior of the microballoons above their Tm was subsequently modeled, using difusion equations that were corrected for shape anisotropy and elastic restoring forces. A shape-related and expansion dependent pre-factor was used to dynamically address the influence of the shell thickness differences along the circumference on the inflation velocity, whereas the microballoon's elastic contraction upon inflation was rendered by the inclusion of a hyperelastic constitutive model. An important finding resulting from this model was the pronounced increase in inflation velocity compared to hypothetical capsules with a homogeneous shell thickness, which stresses the benefit of employing shape anisotropic balloon-like capsules in this study. Furthermore, the model was able to predict the finite expandability on basis of entropy-elastic recovery forces and strain-hardening effects. A comparison of six different microballoons with different shell thicknesses and internal salt contents showed the linear relationship between the volumetric expansion, the shell thickness and the applied osmotic pressure, as represented by the model. As the proposed model facilitates the prediction of the expansion kinetics depending on the membranes mechanical and diffusional characteristics, it might be a screening tool for future material selections. In course of the microballoon expansion process, capsules of intermediate diameters could be isolated by recrystallization of the membrane, which is mainly caused by a restoration of the membrane's mechanical stiffness and is otherwise difficult to achieve with other stimuli-sensitive systems. The capsule's crystallinity of intermediate expansion states was nearly unchanged, whereas the lamellar crystal size tends to decreased with the expansion ratio. Therefore, it was assumed that the elastic modulus was only minimally altered and might increased due to the networks segment-chain extension. In addition to the volume increase achieved by inflation, a turn in the osmotic gradient also facilitated the reversible deflation, which was shown in inflation/deflation cycles. These both characteristics of the introduced microballoons are important parameter regarding the realization of micropumps and microvalves. The fixation of expanded microcapsules via recrystallization enabled the storage of entropy-elastic strain-energy, which could be utilized for pumping actions in non-aqueous media. Here, the pumping velocity depended on both, the type of surrounding medium and the applied temperature. Surrounding media that supported the fast transport of pumped liquid showed an accelerated deflation, while high temperatures further accelerate the pumping velocity. Very fast rejection of the incorporated payload was furthermore realized with pierced expanded microballoons, which were subjected to temperatures above their Tm. The possible fixation of intermediate particle sizes provide opportunities for vent constructions that allowed the precise adjustment of specific flow-rates and multiple valve openings and closings. A valve construction was realized by the insertion of a single or multiple microballoons in a microfluidic channel. A complete and a partial closing of the microballoon-valves was demonstrated as a function of the heating period. In this context, a difference between the inflation and deflation velocity was stated, summarizing slower expansion kinetics. Overall, microballoons, which presented both on-demand pumping and reversible valving by a temperature-triggered change in the capsule's volume, might be suitable components that help to design fully integrated LOC devices, due to the implementation of the control switch and controllable inflation/deflation kinetics. In comparison to other state of the art stimuli-sensitive materials, one has to highlight the microballoons capability of stabilizing almost continuously intermediate capsule sizes by simple recrystallization of the microballoon's membrane.
In times of ongoing biodiversity loss, understanding how communities are structured and what mechanisms and local adaptations underlie the patterns we observe in nature is crucial for predicting how future ecological and anthropogenic changes might affect local and regional biodiversity. Aquatic zooplankton are a group of primary consumers that represent a critical link in the food chain, providing nutrients for the entire food web. Thus, understanding the adaptability and structure of zooplankton communities is essential. In this work, the genetic basis for the different temperature adaptations of two seasonally shifted (i.e., temperature-dependent) occurring freshwater rotifers of a formerly cryptic species complex (Brachionus calyciflorus) was investigated to understand the overall genetic diversity and evolutionary scenario for putative adaptations to different temperature regimes. Furthermore, this work aimed to clarify to what extent the different temperature adaptations may represent a niche partitioning process thus enabling co-existence. The findings were then embedded in a metacommunity context to understand how zooplankton communities assemble in a kettle hole metacommunity located in the northeastern German "Uckermark" and which underlying processes contribute to the biodiversity patterns we observe. Using a combined approach of newly generated mitochondrial resources (genomes/cds) and the analysis of a candidate gene (Heat Shock Protein 40kDa) for temperature adaptation, I showed that the global representatives of B. calyciflorus s.s.. are genetically more similar than B. fernandoi (average pairwise nucleotide diversity: 0.079 intraspecific vs. 0.257 interspecific) indicating that both species carry different standing genetic variation. In addition to differential expression in the thermotolerant B. calyciflorus s.s. and thermosensitive B. fernandoi, the HSP 40kDa also showed structural variation with eleven fixed and six positively selected sites, some of which are located in functional areas of the protein. The estimated divergence time of ~ 25-29 Myr combined with the fixed sites and a prevalence of ancestral amino acids in B. calyciflorus s.s. indicate that B. calyciflorus s.s. remained in the ancestral niche, while B. fernandoi partitioned into a new niche. The comparison of mitochondrial and nuclear markers (HPS 40kDa, ITS1, COI) revealed a hybridisation event between the two species. However, as hybridisation between the two species is rare, it can be concluded that the temporally isolated niches (i.e., seasonal-shifted occurrence) they inhabit based on their different temperature preferences most likely represent a pre-zygotic isolation mechanism that allows sympatric occurrence while maintaining species boundaries. To determine the processes underlying zooplankton community assembly, a zooplankton metacommunity comprising 24 kettle holes was sampled over a two-year period. Active (i.e., water samples) and dormant communities (i.e., dormant eggs hatched from sediment) were identified using a two-fragment DNA metabarcoding approach (COI and 18S). Species richness and diversity as well as community composition were analysed considering spatial, temporal and environmental parameters. The analysis revealed that environmental filtering based on parameters such as pH, size and location of the habitat patch (i.e., kettle hole) and surrounding field crops largely determined zooplankton community composition (explained variance: Bray-Curtis dissimilarities: 10.5%; Jaccard dissimilarities: 12.9%), indicating that adaptation to a particular habitat is a key feature of zooplankton species in this system. While the spatial configuration of the kettle holes played a minor role (explained variance: Bray-Curtis dissimilarities: 2.8% and Jaccard dissimilarities: 5.5%), the individual kettle hole sites had a significant influence on the community composition. This suggests monopolisation/priority effects (i.e., dormant communities) of certain species in individual kettle holes. As environmental filtering is the dominating process structuring zooplankton communities, this system could be significantly influenced by future land-use change, pollution and climate change.
Das Eigene und das Fremde
(2023)
Die vorliegende Arbeit stellt eine Untersuchung des Fremdverstehens von Lehrkräften im Mathematikunterricht dar. Mit ‚Fremdverstehen‘ soll dabei – in Anlehnung an den Soziologen Alfred Schütz – der Prozess bezeichnet werden, in welchem eine Lehrkraft versucht, das Verhalten einer Schülerin oder eines Schülers zu verstehen, indem sie dieses Verhalten auf ein Erleben zurückführt, das ihm zugrunde gelegen haben könnte. Als ein wesentliches Merkmal des Prozesses stellt Schütz in seiner Theorie des Fremdverstehens heraus, dass das Fremdverstehen eines Menschen immer auch auf seinen eigenen Erlebnissen basiert. Aus diesem Grund wird in der Arbeit ein methodischer Zweischritt vorgenommen: Es werden zunächst die mathematikbezogenen Erlebnisse zweier Lehrkräfte nachgezeichnet, bevor dann ihr Fremdverstehen in konkreten Situationen im Mathematikunterricht rekonstruiert wird. In der ersten Teiluntersuchung (= der Rekonstruktion eigener Erlebnisse der untersuchten Lehrkräfte) erfolgt die Datenerhebung mit Hilfe biographisch-narrativer Interviews, in denen die untersuchten Lehrkräfte angeregt werden, ihre mathematikbezogene Lebensgeschichte zu erzählen. Die Analyse dieser Interviews wird im Sinne der rekonstruktiven Fallanalyse vorgenommen. Insgesamt führt die erste Teiluntersuchung zu textlichen Darstellungen der rekonstruierten mathematikbezogenen Lebensgeschichte der untersuchten Mathematiklehrkräfte. In der zweiten Teiluntersuchung (= der Rekonstruktion des Fremdverstehens der untersuchten Lehrkräfte) werden dann narrative Interviews geführt, in denen die untersuchten Lehrkräfte von ihrem Fremdverstehen in konkreten Situationen im Mathematikunterricht erzählen. Die Analyse dieser Interviews erfolgt mit Hilfe eines dreischrittigen Analyseverfahrens, welches die Autorin eigens zum Zweck der Rekonstruktion von Fremdverstehen entwickelte. Am Ende dieser zweiten Teiluntersuchung werden sowohl das rekonstruierte Fremdverstehen der Lehrkräfte in verschiedenen Unterrichtssituationen dargestellt als auch Strukturen, die sich in ihrem Fremdverstehen abzeichnen. Mit Hilfe einer theoretischen Verallgemeinerung werden schließlich – auf Basis der Ergebnisse der zweiten Teiluntersuchung – Aussagen über fünf Merkmale des Fremdverstehens von Lehrkräften im Mathematikunterricht im Allgemeinen gewonnen. Mit diesen Aussagen vermag die Arbeit eine erste Beschreibung davon hervorzubringen, wie sich das Phänomen des Fremdverstehens von Lehrkräften im Mathematikunterricht ausgestalten kann.
Von Ulfila bis Rekkared
(2014)
Für etwa 200 Jahre, vom Ende des 4. Jahrhunderts bis 589 n. Chr., gehören die Westgoten einem von der Orthodoxie der Reichskirche abweichenden christlichen Bekenntnis an. Auf dem 3. Konzil von Toledo beendet König Rekkared diesen Zustand religiöser Alterität durch die Konversion zum Katholizismus. Die antiken Berichte zeichnen nur vordergründig ein kohärentes Bild des Christentums der Goten. Dagegen weist Eike Faber Widersprüche und Fehler in der Überlieferung nach und bietet eine Reihe neuer Interpretationen an. Die genauere Betrachtung vermag dabei sowohl den dogmatischen Gehalt des Christentums der Goten schärfer zu konturieren als auch die Beweggründe für die Annahme des neuen Glaubens herauszustellen und die traditionelle Datierung dieses Vorgangs zu widerlegen. Schließlich wird deutlich, welche Funktion das fortgesetzte Festhalten an einer demonstrativ anderen religiösen Überzeugung für die Goten hatte. Prägnante Wegmarken der gotischen Geschichte, wie die Bibelübersetzung Ulfilas, die Eroberung und Plünderung Roms 410 n. Chr. oder die demonstrative Aufgabe der religiösen Differenz durch König Rekkared, werden erst durch diesen neuen, umfassenden Kontext verständlich.
Mitochondria and plastids are organelles with an endosymbiotic origin. During evolution, many genes are lost from the organellar genomes and get integrated in the nuclear genome, in what is known as intracellular/endosymbiotic gene transfer (IGT/EGT). IGT has been reproduced experimentally in Nicotiana tabacum at a gene transfer rate (GTR) of 1 event in 5 million cells, but, despite its centrality to eukaryotic evolution, there are no genetic factors known to influence the frequency of IGT in higher eukaryotes. The focus of this work was to determine the role of different DNA repair pathways of double strand break repair (DSBR) in the integration step of organellar DNA in the nuclear genome during IGT. Here, a CRISPR/Cas9 mutagenesis strategy was implemented in N. tabacum, with the aim of generating mutants in nuclear genes without expected visible phenotypes. This strategy led to the generation of a collection of independent mutants in the LIG4 (necessary for non-homologous end joining, NHEJ) and POLQ genes (necessary for microhomology mediated end joining, MMEJ). Targeting of other DSBR genes (KU70, KU80, RPA1C) generated mutants with unexpectedly strong developmental phenotypes.. These factors have telomeric roles, hinting towards a possible relationship between telomere length, and strength of developmental disruption upon loss of telomere structure in plants. The mutants were made in a genetic background encoding a plastid-encoded IGT reporter, that confers kanamycin resistance upon transfer to the nucleus. Through large scale independent experiments, increased IGT from the chloroplast to the nucleus was observed in lig4 mutants, as well as lines encoding a POLQ gene with a defective polymerase domain (polqΔPol). This shows that NHEJ or MMEJ have a double-sided relationship with IGT: while transferred genes may integrate using either pathway, the presence of both pathways suppresses IGT in wild-type somatic cells, thus demonstrating for the first time the extent on which nuclear genes control IGT frequency in plants. The IGT frequency increases in the mutants are likely mediated by increased availability of double strand breaks for integration. Additionally, kinetic analysis reveals that gene transfer (GT) events accumulate linearly as a function of time spent under antibiotic selection in the experiment, demonstrating that, contrary to what was previously thought, there is no such thing as a single GTR in somatic IGT experiments. Furthermore, IGT in tissue culture experiments appears to be the result of a "race against the clock" for integration in the nuclear genome, that starts when the organellar DNA arrives to the nucleus granting transient antibiotic resistance. GT events and escapes of kanamycin selection may be two possible outcomes from this race: those instances where the organellar DNA gets to integrate are recovered as GT events, and in those cases where timely integration fails, antibiotic resistance cannot be sustained, and end up considered as escapes. In the mutants, increased opportunities for integration in the nuclear genome change the overall ratio between IGT and escape events. The resources generated here are promising starting points for future research: (1) the mutant collection, for the further study of processes that depend on DNA repair in plants (2) the collection of GT lines obtained from these experiments, for the study of the effect of DSBR pathways over integration patterns and stability of transferred genes and (3) the developed CRISPR/Cas9 workflow for mutant generation, to make N. tabacum meet its potential as an attractive model for answering complex biological questions.
Social networking sites
(2023)
"Il Gattopardo" nella DDR
(2023)
Sulla base di materiale d'archivio inedito si ripercorre l'avvincente storia della prima edizione del Gattopardo nella DDR (1961). È qui analizzata la corsa ad ostacoli del romanzo tra congruenze ed eccezioni che assume i tratti di un giallo letterario. L'opera di un principe defunto scavalca il Muro grazie ad Alfred Kurella, potente funzionario della SED. Nella sua postfazione Il Gattopardo non è canto della decadenza, ma preannuncio di una nuova epoca, manifesto dello Stato in procinto di entrare nell'era socialista. La chiave di lettura è un unicum con una marcata impronta ideologica che ne determina prima la fortuna e poi l'isolamento. Al Gattopardo nella Germania Est Bernardina Rago dà per la prima volta voce.
De/lirios
(2023)
En base al concepto de "de/lirio", que articula trastornos en la enunciación literaria en primera persona, por un lado, con la caracterización psicopatológica de este yo enunciativo, por otro lado, el estudio explora las "líricas desviadas" de Mario Levrero y Alberto Laiseca, y muestra como responden productivamente a problemáticas estéticas, éticas y ontológicas propias de la vuelta del milenio, en el Río de la Plata y más allá.
The aim of this work is the study of silica Arrayed Waveguide Gratings (AWGs) in the context of applications in astronomy. The specific focus lies on the investigation of the feasibility and technology limits of customized silica AWG devices for high resolution near-infrared spectroscopy. In a series of theoretical and experimental studies, AWG devices of varying geometry, foot-print and spectral resolution are constructed, simulated using a combination of a numerical beam propagation method and Fraunhofer diffraction and fabricated devices are characterized with respect to transmission efficiency, spectral resolution and polarization sensitivity. The impact of effective index non-uniformities on the performance of high-resolution AWG devices is studied numerically. Characterization results of fabricated devices are used to extrapolate the technology limits of the silica platform. The important issues of waveguide birefringence and defocus aberration are discussed theoretically and addressed experimentally by selection of an appropriate aberration-minimizing anastigmatic AWG layout structure. The drawbacks of the anastigmatic AWG geometry are discussed theoretically. From the results of the experimental studies, it is concluded that fabrication-related phase errors and waveguide birefringence are the primary limiting factors for the growth of AWG spectral resolution. It is shown that, without post-processing, the spectral resolving power is phase-error-limited to R < 40, 000 and, in the case of unpolarized light, birefringence-limited to R < 30, 000 in the AWG devices presented in this work. Necessary measures, such as special waveguide geometries and post-fabrication phase error correction are proposed for future designs. The elimination of defocus aberration using an anastigmatic AWG geometry is successfully demonstrated in experiment. Finally, a novel, non-planar dispersive in-fibre waveguide structure is proposed, discussed and studied theoretically.
Das menschenrechtliche Prinzip des Non-Refoulement vor den Vertragsorganen der Vereinten Nationen
(2023)
Die Vertragsorgane der Vereinten Nationen können durch die Abstimmung ihrer Praxis Rechtssicherheit schaffen, und zwar sowohl für Betroffene als auch für die Vertragsstaaten. Durch den ständigen Dialog mit den Vertragsstaaten, die Beeinflussung der Vertragsorgane untereinander und das Aufgreifen der Praxis durch andere internationale Akteure lässt sich Gewohnheitsrecht identifizieren. -- Dabei ist das menschenrechtliche Prinzip des Non-Refoulement besonders geeignet, dieses Potenzial der Vertragsorgane zu veranschaulichen. Hierbei handelt es sich um ein Rechtsprinzip, das zwar dem Grunde nach allgemein anerkannt ist, dessen Reichweite im Detail jedoch kontinuierlich umstritten ist. Erstmals wird ein umfassender Überblick über die gesamte Praxis der Vertragsorgane zum Prinzip des Non-Refoulement gegeben. Es wird gezeigt, wie sich die Vertragsorgane sowohl auf prozessualer Ebene als auch bei der Bestimmung des materiellen Schutzbereichs von Refoulementverboten einander annähern.
In jüngerer Vergangenheit häuften sich Fälle, in denen die Verwaltung Entscheidungen von Verwaltungsgerichten bewusst nicht umsetzte. Der Autor nimmt diese Entwicklung zum Anlass und befasst sich mit der Frage, welchen Anteil die Vollstreckungsregeln der Verwaltungsgerichtsordnung an dieser Entwicklung haben. Dabei erfasst er sowohl die staatsrechtliche als auch die grundrechtliche Perspektive. Er überprüft insbesondere, ob die Vorschriften, die die Vollstreckung aus verwaltungsgerichtlichen Entscheidungen gegen den Staat regeln, verfassungsgemäß sind. Nach ausführlicher Diskussion denkbarer Lösungsansätze kommt der Autor zu dem Ergebnis, dass eine Änderung der Vollstreckungsvorschriften dringend geboten ist.
The African weakly electric fish genus Campylomormyrus includes 15 described species mostly native to the Congo River and its tributaries. They are considered sympatric species, because their distribution area overlaps. These species generate species-specific electric organ discharges (EODs) varying in waveform characteristics, including duration, polarity, and phase number. They exhibit also pronounced divergence in their snout, i.e. the length, thickness, and curvature. The diversifications in these two phenotypical traits (EOD and snout) have been proposed as key factors promoting adaptive radiation in Campylomormyrus. The role of EODs as a pre-zygotic isolation mechanism driving sympatric speciation by promoting assortative mating has been examined using behavioral, genetical, and histological approaches. However, the evolutionary effects of the snout morphology and its link to species divergence have not been closely examined. Hence, the main objective of this study is to investigate the effect of snout morphology diversification and its correlated EOD to better understand their sympatric speciation and evolutionary drivers. Moreover, I aim to utilize the intragenus and intergenus hybrids of Campylomormyrus to better understand trait divergence as well as underlying molecular/genetic mechanisms involved in the radiation scenario. To this end, I utilized three different approaches: feeding behavior analysis, diet assessment, and geometric morphometrics analysis. I performed feeding behavior experiments to evaluate the concept of the phenotype-environment correlation by testing whether Campylomormyrus species show substrate preferences. The behavioral experiments showed that the short snout species exhibits preference to sandy substrate, the long snout species prefers a stone substrate, and the species with intermediate snout size does not exhibit any substrate preference. The experiments suggest that the diverse feeding apparatus in the genus Campylomormyrus may have evolved in adaptation to their microhabitats. I also performed diet assessments of sympatric Campylomormyrus species and a sister genus species (Gnathonemus petersii) with markedly different snout morphologies and EOD using NGS-based DNA metabarcoding of their stomach contents. The diet of each species was documented showing that aquatic insects such as dipterans, coleopterans and trichopterans represent the major diet component. The results showed also that all species are able to exploit diverse food niches in their habitats. However, comparing the diet overlap indices showed that different snout morphologies and the associated divergence in the EOD translated into different prey spectra. These results further support the idea that the EOD could be a ‘magic trait’ triggering both adaptation and reproductive isolation. Geometric morphometrics method was also used to compare the phenotypical shape traits of the F1 intragenus (Campylomormyrus) and intergenus (Campylomormyrus species and Gnathonemus petersii) hybrids relative to their parents. The hybrids of these species were well separated based on the morphological traits, however the hybrid phenotypic traits were closer to the short-snouted species. In addition, the likelihood that the short snout expressed in the hybrids increases with increasing the genetic distance of the parental species. The results confirmed that additive effects produce intermediate phenotypes in F1-hybrids. It seems, therefore, that morphological shape traits in hybrids, unlike the physiological traits, were not expressed straightforward.
Beinahe 30 Jahre lang glänzte die »Völkerfreundschaft« zwischen Kuba und der DDR im öffentlichen Diskurs der SED als Musterbeispiel ihres proletarischen Internationalismus. Doch die Rhetorik täuscht: Besonders in den Anfangsjahren der bilateralen Beziehungen nahmen die deutschen Kader ihre kubanischen »Genossen« in der Karibik als notorische Querschläger wahr, die mit ihrem Aufbegehren gegen den ideologischen Suprematieanspruch des Kremls die Stabilität des Ostblocks gefährdeten.
Anhand bislang unveröffentlichten Quellenmaterials aus deutschen und kubanischen Archiven veranschaulicht Antonia Bihlmayer die Bemühungen der Regierung Walter Ulbrichts, die widerspenstigen Sozialisten in der Karibik auf Moskau auszurichten. Auf politisch-ideologischer, wirtschaftlicher und kulturpolitischer Ebene analysiert ihre Studie zum einen die Charakteristika dieser sozialistischen Zivilisierungsmission. Zum anderen nimmt sie diejenigen Faktoren in den Blick, die dafür ausschlaggebend waren, dass sich diese beiden sozialistischen Enklaven ab Mitte der 1970er Jahre schließlich zu gleichwertigen »Juniorpartnern« der Sowjetunion entwickelten.
Answer Set Programming (ASP) allows us to address knowledge-intensive search and optimization problems in a declarative way due to its integrated modeling, grounding, and solving workflow. A problem is modeled using a rule based language and then grounded and solved. Solving results in a set of stable models that correspond to solutions of the modeled problem. In this thesis, we present the design and implementation of the clingo system---perhaps, the most
widely used ASP system. It features a rich modeling language originating from the field of knowledge representation and reasoning, efficient grounding algorithms based on database evaluation techniques, and high performance solving algorithms based on Boolean satisfiability (SAT) solving technology.
The contributions of this thesis lie in the design of the modeling language, the design and implementation of the grounding algorithms, and the design and implementation of an Application Programmable Interface (API) facilitating the use of ASP in real world applications and the implementation of complex forms of reasoning beyond the traditional ASP workflow.
Für die Sondernutzung des gemeindlichen Verkehrsraumes durch die Verlegung und den Betrieb von Leitungen kann die Gemeinde vom Wasserversorger eine Konzessionsabgabe erheben. Gleichwohl kleine Regie- und Eigenbetriebe den größten Teil der Wasserversorger ausmachen, ein Großteil der Abnehmerbeziehungen über Gebühren ausgestaltet ist, und Konzessionsabgaben einen beachtlichen Faktor in den kommunalen Haushalten darstellen, ist die Frage, ob von einem Eigenbetrieb gezahlte Konzessionsabgaben in die Gebührenkalkulation eingestellt werden können, umstritten. Mehrere Oberverwaltungsgerichte verneinen dies. Die Verfasserin untersucht die zugrundeliegende Thematik aus zahlreichen rechtlichen Perspektiven und widerspricht der Rechtsprechung.
The Media Privilege under Data Protection Law: Journalism and data protection are fundamentally at odds with each other. In view of current developments, the need for a functioning regulatory concept for both legal positions is probably more important than ever. This conceptual balance is provided by the journalistic exemption in data protection law. The thesis focuses on the scope of the exception. It also identifies existing coherence problems between European and national law.
Investment control has experienced a considerable increase in importance in M&A transactions, as it has been constantly adapted to real economic conditions and successively tightened. The result is a partially inconsistent review regime that contains value contradictions and creates legal uncertainties. In a comprehensive approach, this doctoral thesis analyzes the problems of the current investment control regime and states concrete reform proposals.
In der vorliegenden Arbeit liegt der Fokus auf jungen russischsprachigen Jüdinnen und Juden, deren Eltern in den 90er Jahren des 20 Jahrhunderts nach Deutschland eingewandert sind. Im Rahmen dieser Studie wird der Bildungsweg dieser MigrantInnengruppe und deren Erfahrungen in Deutschland aus der biographischen Perspektive nachvollzogen. Der Fokus wird insbesondere auf die biographischen Lebenserfahrungen gelegt, d.h. die allgemeinen Lebensumstände, Hürden und Schwierigkeiten, die die jungen russischsprachigen Jüdinnen und Juden in Deutschland überwinden mussten, um auf ihrem Bildungsweg an ihr Ziel zu kommen. Des Weiteren werden die Rolle des sozialen Umfelds auf die Auswahl ihres Bildungsweges sowie ihre Zugehörigkeit und ihr Beitrag zur deutschen Gesellschaft beleuchtet. Ein weiteres Hauptaugenmerk dieser Arbeit liegt auf den gesellschaftlichen, politischen und familiären Rahmenbedingungen, die den BiographInnen den Zugang zum Bildungsweg ermöglichten.
Die in der Arbeit formulierten Forschungsfragen wurden mithilfe der interpretativen Sozialforschung, genauer, der fallrekonstruktiven Auswertung nach Gabriele Rosenthal beantwortet.
Über den biographischen Verlauf der Lebensgeschichte der jungen russischsprachigen Jüdinnen und Juden wurde deutlich, dass die BiographInnen in die säkulare Gesellschaft gehen müssen, um ihren Bildungsweg erfolgreich zu gestalten. Dort erfahren sie einen sehr starken Antisemitismus und sind diesem schutzlos ausgeliefert. Bei allen drei Interviewten wurde diese Erfahrung in der Schule gemacht, an einem Ort, an dem sie Schutz erfahren sollten. Diesen Anfeindungen begegneten sie auf unterschiedliche Weise und sie entwickelten verschiedene Handlungsstrategien. Einige BiographInnen setzen sich auf der intellektuellen Ebene bewusst damit auseinander, andere wiederum versuchen, nicht hinzuschauen und es zu ignorieren.
Des Weiteren wurde als Resultat der Untersuchung in einigen Fällen ein übereinstimmendes, in anderen ein nicht übereinstimmendes Passungsverhältnis zwischen elterlichen Vorstellungen und den Bildungswegen der jungen russischsprachigen Jüdinnen und Juden gefunden.
Das kolonisierte Heiligtum
(2022)
Während der Zeit des historischen Kolonialismus wurden in Völkerkundemuseen komplexe Formen rassistischer und religiöser Diskriminierung institutionalisiert, z.B. in den dort gültigen Ästhetik- und Kunstbegriffen. Viele der heutigen Museumsangestellten erklären sich deswegen zu Reformen bereit. Doch können sie sich tatsächlich vom Kolonialismus trennen? Ist eine Dekolonisation ethnologischer Museen mit kolonialer Beute je abschließend möglich? Am Beispiel umstrittener Heiligtümer lebender Kulturen untersucht Christoph Balzar das Verfahren der Musealisierung durch die Linse der Diskriminierungskritik. Im Fokus stehen dabei die Sammlungen der »Staatlichen Museen zu Berlin«.
Zu Seiner Majestät allerhöchstem Interesse als titelgebendem Zitat bekannten sich die zeitgenössischen Amtsträger in ihrer Beeidigung als grundlegende Maxime des durch den König verkörperten werdenden preussischen Staates.Die Domänenpolitik Friedrich Wilhelms I., dem zweiten preussischen König, war die wesentliche Voraussetzung für die folgende Entwicklung Preussens von einer Regionalmacht im Heiligen Römischen Reich zu einer europäischen Grossmacht. Ohne nennenswerte Rohstoffe und handwerkliche Traditionen, agrarisch geprägt und ganz dem merkantilistischen Wirtschaftsmodell und seiner kameralistischen Methodik verhaftet, war der Ausbau und die Intensivierung der landesherrlichen Gutswirtschaft der für Preussen verheissungsvollste Weg zur Erwirtschaftung der Mittel, die es zum Schuldenabbau, dem Aufbau einer starken Militärmacht und Anhäufung eines Staatsschatzes befähigte. Erreicht wurde dies durch konsequente Einnahmen- und Ausgabenkontrolle und die Schaffung eines effizienten Verwaltungsapparates mit detaillierten Vorschriften, was knapp einhundert Jahre Bestand behalten sollte und bis zu nahezu 50 Prozent der Staatseinnahmen hervorbrachte. Das friderizianische Preussen wäre ohne die Leistungen Friedrich Wilhelms I. nicht möglich gewesen.Der vorliegende Band stellt diese Entwicklung mit einer Fülle von Quellenmaterial und dessen Auswertungen sowie einem umfangreichen Anhang unter Beweis. Der allein 22seitige Personenindex mit über 1.300 Verweisen und 103 Kurzbiogra-fien der kurmärkischen Kammerräte machen deutlich, wer hinter den Leistungen dieser Epoche stand.
Der Jüdische Friedhof in Potsdam am Pfingstberg wurde 1743 angelegt und kontinuierlich bis in die NS-Zeit belegt. Bis Anfang des 21. Jahrhunderts gab es vereinzelte Begräbnisse mit Bezug zur alten Jüdischen Gemeinde Potsdams; mehrere Gedenkanlagen wurden errichtet. Mit mehr als 500 historischen Grabanlagen, seinem Ensemble aus Friedhofsbauten sowie aufgrund seiner Landschaftsarchitektur gehört dieser Ort heute zum UNESCO-Welterbe.
Teil 1 von Anke Geißler-Grünbergs Studie ist der Geschichte des Friedhofs gewidmet. Nach einem Blick auf die Rolle der Jüdischen Gemeinde Potsdams als Eigentümerin des Friedhofs erfolgt unter Auswertung von umfangreichem Archivmaterial eine detaillierte Darstellung der Geschichte des „Guten Ortes“. Eine Untersuchung sämtlicher Grabmale auf unterschiedliche Gestaltungsmerkmale visualisiert und rekonstruiert die Veränderungen in der erhaltenen Sepulkralkultur. Abschließend richtet sich der Fokus auf den Umgang mit dem Friedhof als Ort der Erinnerung.
Teil 2 bietet die Dokumentation von 370 Grabanlagen. Um den Friedhof in seiner Gesamtheit abzubilden, wurde die 1992 erfolgte Teildokumentation der 158 Grabsteine des gesamten ältesten Begräbnisfeldes ergänzend hinzugenommen. Mit mehr als 1.000 Fotos wird hier ein einmaliges Zeugnis der Brandenburger Juden dokumentiert.
Der Jüdische Friedhof in Potsdam am Pfingstberg wurde 1743 angelegt und kontinuierlich bis in die NS-Zeit belegt. Bis Anfang des 21. Jahrhunderts gab es vereinzelte Begräbnisse mit Bezug zur alten Jüdischen Gemeinde Potsdams; mehrere Gedenkanlagen wurden errichtet. Mit mehr als 500 historischen Grabanlagen, seinem Ensemble aus Friedhofsbauten sowie aufgrund seiner Landschaftsarchitektur gehört dieser Ort heute zum UNESCO-Welterbe.
Teil 1 von Anke Geißler-Grünbergs Studie ist der Geschichte des Friedhofs gewidmet. Nach einem Blick auf die Rolle der Jüdischen Gemeinde Potsdams als Eigentümerin des Friedhofs erfolgt unter Auswertung von umfangreichem Archivmaterial eine detaillierte Darstellung der Geschichte des „Guten Ortes“. Eine Untersuchung sämtlicher Grabmale auf unterschiedliche Gestaltungsmerkmale visualisiert und rekonstruiert die Veränderungen in der erhaltenen Sepulkralkultur. Abschließend richtet sich der Fokus auf den Umgang mit dem Friedhof als Ort der Erinnerung.
Teil 2 bietet die Dokumentation von 370 Grabanlagen. Um den Friedhof in seiner Gesamtheit abzubilden, wurde die 1992 erfolgte Teildokumentation der 158 Grabsteine des gesamten ältesten Begräbnisfeldes ergänzend hinzugenommen. Mit mehr als 1.000 Fotos wird hier ein einmaliges Zeugnis der Brandenburger Juden dokumentiert.
Die betriebliche oder „arbeitsplatzorientierte Grundbildung (AoG)“ ist ein noch junges Forschungsgebiet der wissenschaftlichen Erwachsenenbildung. Neuerdings wenden sich auch betriebliche Kursangebote an die „Bildungsverlierer“ unseres Schulsystems, die mit z.T. massiven Problemen die Haupt- oder Sonderschule verlassen. Diese qualitative Studie ist dem Bereich der subjektwissenschaftlichen Lernforschung zuzuordnen. Sie rekonstruiert die subjektiven Lernbegründungen der formal gering literalisierten Beschäftigten, wenn sie an Grundbildungskursen am Arbeitsplatz teilnehmen. Die Studie zeigt auf, dass erhebliche lernbiografisch begründete Widerstände überwunden werden müssen, um – eingebettet in Anerkennungsverhältnisse im Kurs – zu persönlich bedeutsamem produktivem Lernen vorzudringen. Zunächst sind Freiwilligkeit und Teilnehmendenorientierung in Kursen häufig in Frage gestellt. Mehr oder weniger reflektierte Lernwiderstände mit defensiven Lerngründen werden insofern vom Autor als subjektiv sinnvolle Handlungsstrategien verstanden. Als lebenslang tätiger Praktiker erläutert der Autor, wie die Resultate der Studie für eine gute Praxis betrieblicher Grundbildung genutzt werden können.
Queer Curating
(2022)
Dieses Buch ist für alle, die mutig genug sind, sich selbst und das Zeigen von Kunst zu stören. Beatrice Miersch entwirft radikal-relationale Alternativen zu zeitgenössischen Ausstellungspraktiken. Um sich der gesellschaftlichen Verantwortung im Rahmen des Ausstellens von Kunst zu stellen, erprobt sie queer-feministische, kulturwissenschaftliche und selbstreflektierende Methoden in der Praxis und Theorie des Kuratierens. Momente kuratorischer Störung werden zu produktiv-schöpferischen Momenten der Unterbrechung, mit denen sie reflektierte, offene, engagierte und vulnerable Perspektiven auf das Ausstellen eröffnet und tradierte Strukturen durchbricht.
Die Conversos
(2022)
Das 15. Jahrhundert ist das Zeitalter der letzten Massenkonversionen zum Christentum auf der Iberischen Halbinsel. Unter starkem Druck und zum Teil mit Gewalt wurde die zuvor große jüdische Bevölkerung gedrängt, sich taufen zu lassen. Gleichwohl akzeptierten große Teile der christlichen Mehrheit die Neubekehrten nicht als gleichwertig und bezweifelten ihre Rechtgläubigkeit. Gegen diese Diskriminierung wandten sich immer wieder Geistliche und Gelehrte mit Predigten, Briefen und Denkschriften. Die vorliegende Studie zeichnet erstmals detailliert die wesentlichen Inhalte ihrer Theologie nach, ihre spezielle Auslegung der Bibel und deren Wurzeln in Recht und Tradition der lateinischen Kirche.
Die Arbeit ist ein Beitrag zu einer grundlegenden Diskussion der Kapitalmarktforschung, dem messbaren Erfolg „aktiver vs. passiver“ Investmentstrategien. Der Autor setzt sich kritisch mit den wesentlichen Anlagestrategien und Modellen für Indexprodukte auseinander und beleuchtet zugleich Closet Indexing bei aktiv gemanagten Investmentfonds. Das Ergebnis zeigt, dass Closet Indexing nicht nur sporadisch auftritt, sondern eine weit verbreitete Anlagestrategie in vielen vermeintlich aktiv gemanagten Aktieninvestmentfonds ist.
Social networking site use and well-being - a nuanced understanding of a complex relationship
(2022)
Social Networking Sites (SNSs) are ubiquitous and attract an enormous chair of the digital population. Their functionalities allow users to connect and interact with others and weave complex social networks in which social information is continuously disseminated between users. Besides the social value SNSs are generating, they likewise attract companies and allow for new forms of marketing, thereby creating considerable economic value alike. However, as SNSs grew in popularity, so did concerns about the impact of their use on social interactions in general and the well-being of individual users in particular. While existing scientific evidence points to both risk as well as benefits of SNS use, research still lacks a profound understanding of which aspects of SNSs enable an impact on well-being and which psychological processes on the part of the users underly and explain this relationship. Therefore, this thesis is dedicated to an in-depth exploration of the relationship between SNS use and well-being and aims to answer how SNS use can impact well-being. Primarily, it focuses on the unique technological features that characterize SNSs and enable potential well- being alterations and on specific psychological processes on the part of the users, underlying and explaining the relationship. For this purpose, the thesis first introduces the concept of well- being. It continues by presenting SNSs’ unique technological features, divided into specifics of the content disseminated on SNSs and the network structure of SNSs. Further, the thesis introduces three classes of psychological processes assumed most relevant for the relationship between SNSs and well-being: other-focused, self-focused, and contrastive processes.. It is assumed that the course and quality of these common processes change in the SNS context and that a complex interplay between the unique features of SNSs and these processes determines how SNSs may ultimately affect users' well-being - both in positive and negative ways. The dissertation comprises seven research articles, each of which focusses on a particular set of SNS characteristics, their interplay with one or more of the proposed psychological processes, and ultimately the resulting effects on user well-being or its key resilience and risk factors. The seven articles investigate this relationship using different methodological approaches. Three articles are based on either systematic or narrative literature reviews, one applies an empirical cross-sectional research design, and three articles present an experimental investigation. Thematically, two articles revolve around SNS use’s effect on self-esteem. Three articles examine the specific role of the emotion of envy and its potential to establish and perpetuate a well-being-damaging social climate on SNSs. The two last articles of this thesis revolve around the established assumption that active and passive SNS use, as different modalities of SNS use, cause differential effects on users’ well-being due to the involvement of different psychological processes. The results of this thesis illustrate different ways how SNSs can affect users’ well-being. The results suggest that especially contrastive processes play a decisive role in explaining potential well-being risks for SNS users. Their interplay with certain SNS features seems to foster upward social comparisons and feelings of envy, potentially leading to a complex set of deleterious effects on users’ well-being. At the same time, the findings illuminate ways in which SNSs can benefit users and their self-esteem – especially when SNS use promotes self- focused and social-feedback-based other-focused processes. The thesis and their findings illustrate that the relationship between SNSs and well-being is complex. Therefore, a nuanced perspective, taking into consideration both the technological uniqueness of SNSs and the psychological processes they are enabling, is crucial to understand how these technologies affect their users in good and potentially harmful ways. On the one hand, the gathered insights contribute to research, providing novel insights into the complex relationship between SNS use and well-being. On the other hand, the results enable a focused and action-oriented derivation of recommendations for stakeholders such as individual users, policymakers, and platform providers. The findings of this thesis can help them to better combat SNS-related risks and ultimately ensure a healthy and sustainable environment for users - and thus also the economic values of SNSs - in the long term.
Seismology, like many scientific fields, e.g., music information retrieval and speech signal pro- cessing, is experiencing exponential growth in the amount of data acquired by modern seismo- logical networks. In this thesis, I take advantage of the opportunities offered by "big data" and by the methods developed in the areas of music information retrieval and machine learning to predict better the ground motion generated by earthquakes and to study the properties of the surface layers of the Earth. In order to better predict seismic ground motions, I propose two approaches based on unsupervised deep learning methods, an autoencoder network and Generative Adversarial Networks. The autoencoder technique explores a massive amount of ground motion data, evaluates the required parameters, and generates synthetic ground motion data in the Fourier amplitude spectra (FAS) domain. This method is tested on two synthetic datasets and one real dataset. The application on the real dataset shows that the substantial information contained within the FAS data can be encoded to a four to the five-dimensional manifold. Consequently, only a few independent parameters are required for efficient ground motion prediction. I also propose a method based on Conditional Generative Adversarial Networks (CGAN) for simulating ground motion records in the time-frequency and time domains. CGAN generates the time-frequency domains based on the parameters: magnitude, distance, and shear wave velocities to 30 m depth (VS30). After generating the amplitude of the time-frequency domains using the CGAN model, instead of classical conventional methods that assume the amplitude spectra with a random phase spectrum, the phase of the time-frequency domains is recovered by minimizing the observed and reconstructed spectrograms. In the second part of this dissertation, I propose two methods for the monitoring and characterization of near-surface materials and site effect analyses. I implement an autocorrelation function and an interferometry method to monitor the velocity changes of near-surface materials resulting from the Kumamoto earthquake sequence (Japan, 2016). The observed seismic velocity changes during the strong shaking are due to the non-linear response of the near-surface materials. The results show that the velocity changes lasted for about two months after the Kumamoto mainshock. Furthermore, I used the velocity changes to evaluate the in-situ strain-stress relationship. I also propose a method for assessing the site proxy "VS30" using non-invasive analysis. In the proposed method, a dispersion curve of surface waves is inverted to estimate the shear wave velocity of the subsurface. This method is based on the Dix-like linear operators, which relate the shear wave velocity to the phase velocity. The proposed method is fast, efficient, and stable. All of the methods presented in this work can be used for processing "big data" in seismology and for the analysis of weak and strong ground motion data, to predict ground shaking, and to analyze site responses by considering potential time dependencies and nonlinearities.
Starch is an insoluble polyglucan, comprises of two polymers, namely, the branched α-1,4: α-1,6-D-glucan amylopectin and the almost unbranched α-1,4-D-glucan amylose. The growth of all plants is directly dependent on the accumulation of transitory starch during the daytime when photosynthesis takes place and subsequently starch degradation during the night. Starch phosphorylation takes place by starch-related dikinases called α-glucan, water dikinase (GWD), and phosphoglucan, water dikinase (PWD), and is a very important step in starch degradation. The biochemical mechanisms of phosphorylation of starch are not properly understood. Recent studies have found that there are two starch binding proteins namely, Early Starvation1 (ESV1) and Like Early Starvation1 (LESV), which play an important role in starch metabolism. It has been shown that ESV1 and LESV proteins affect the starch phosphorylation activity of GWD and PWD enzymes, which control the rate of degradation of starch granules. In this thesis, various in vitro assays were performed to identify and understand the mechanism of recombinant proteins; ESV1 and LESV on the starch degradation. The starch degradation was performed by phosphorylation enzymes, GWD and PWD separately. In various enzymatic assays, the influence of the ESV1 and LESV on the actions of GWD and PWD on the surfaces of different native starch granules were analysed. Furthermore, ESV1 and LESV have specifically shown influences on the phosphorylation activities of GWD and PWD on the starch granule surfaces in an antagonistic pattern in such a way that, the GWD mediated phosphorylation were significantly reduced while PWD mediated phosphorylation were significantly increased respectively. In another set of experiments, ISA and BAM hydrolyzing enzymes were used to alter the structure of starch, and then determine the effect of both dikinases mediated phosphorylation in the presence of ESV1 and LESV on the altered starch granules surfaces. In these results, significant decreases in both GWD and PWD mediated phosphorylation were observed in all the treatments containing either ESV1 or LESV proteins only or both ESV1 and LESV. It was also found that LESV preferentially binds to both amylose and amylopectin, while ESV1 binds to highly ordered glucans such as maltodextrins and amylopectin, which are crystalline in structure. Both ESV1 or LESV proteins either individually or in combination have shown influence on the activity of GWD and PWD phosphate incorporation into the starch granules via reduction even though at different percentages depending on the sources of starch, therefore it is difficult to distinguish the specific function between them. The biochemical studies have shown that protein-glucan interaction specifically between ESV1 or LESV or in combination with different species of starch granules has very strong surface binding, or it might be possible that both the proteins not only bind to the surface of the starch granules but also have entered deep inside the glucan structure of the starch granules. However, the results also revealed that ESV1 and LESV did not alter the autophosphorylation of the dikinases. Also, the chain length distribution pattern of the released glucan chains after treatment of starch with ISA enzyme was evaluated with respect to the degree of polymerization (DP) of the different starch granules. Capillary electrophoresis was employed to study the effect of LESV and ESV1 on the chain length distribution. In summary, this study confirms that ESV1 and LESV play an important role in organizing and regulating the starch metabolism process. In the later half, studies were performed to monitor whether the metabolism of carbohydrates and partitioning, contribute to the higher salt tolerance of the facultative halophyte Hordeum marinum when compared to glycophyte Hordeum vulgare. Seedlings with the same size from both species were hydroponically grown at 0, 150, and 300 mM of NaCl for 3 weeks. H. marinum maintained a high relative growth rate, which was found concomitant in higher aptitude plants to maintain efficient shoot tissue hydration and integrity of membrane under salt conditions when compared to H. vulgare. Hence, our data suggested that the change in the starch storage, distribution of soluble sugar concentrations between source and sink organs, and also changes in the level of enzymes involved in the starch metabolism was significant to give insights into the importance of carbohydrate metabolism in barley species with regards to the salt tolerance. Although these results are still in their nascent state, it could be vital for other researchers to formulate future studies. The preliminary results which were studies about the carbohydrate metabolism and partitioning in salt responses in the halophyte H. marinum and the glycophyte H. vulgare revealed that salt tolerance in barley species is not due to osmotic adjustments, but due to other reasons that were not explored in the past studies. However, the activity of DPE2 in H. vulgare was not hampered by the presence of NaCl as observed. While Pho1 and Pho2, activities were highly increased in cultivated barley. These findings could be suggestive of a possible role of these enzymes in the responses of carbohydrate metabolism to salinity. When sea and cultivated barley species were compared, it was discovered that the former had more versatility in carbohydrate metabolism and distribution.
Does youth matter?
(2022)
This dissertation is a compilation of publications and submitted publication manuscripts that seek to improve the understanding of modern partnership trajectories. Romantic relationships constitute one of the most important dimensions in a person’s life. They serve to satisfy social and emotional needs (Arránz Becker, 2008) and have an impact on various other dimensions of life. Since the 1970s, partnership formation has been characterized by increased heterogeneity, has become less ordered and much more diverse in terms of living arrangements and the number of unions across the life course (Helske et al, 2015; Ross et al, 2009). This dissertation argues that while partnerships have become more unstable, the need for attachment and the importance of relationship have remained high, if not increased, as evidenced by the prevalence of couple relationships that have remained quite stable (Eckhardt, 2015). The life course perspective (Elder, 1994; Elder et al., 2004; Mayer, 2009) offers an appropriate framework for the understanding of partnership formations throughout the life course. This perspective stresses the path dependency of the life course as well as the interdependencies of life domains (Bernardi et al., 2019). Thus, it can be argued that conditions, resources, and experiences in youth have a substantial influence on later life course outcomes. Given the increasing heterogeneity of partnership trajectories, research to understand partnership processes cannot be based only on single events (e.g., marriage or divorce) or life stages, but must be explored in a dynamic context and over a longer period of time. In sum, this thesis argues that partnership trajectories have to be considered from a holistic perspective. Not only single transitions or events are useful to describe modern partnership histories adequately, but rather the whole process. Additionally, as partnership trajectories are linked to various outcomes (e.g., economics, health, effects on children), it is therefore highly relevant to improve our understanding of partnership dynamics and their determinants and consequences. Findings in this field of research contribute to a better understanding of how childhood and youth are of prospective importance for the later partnership trajectories and whether there are any long-term effects of the conditions and resources formed and stabilized in youth, which then help to understand and explain partnership dynamics. Thus, the interest of this thesis lies in the longitudinal description and prediction of the dynamics of partnership trajectories in light of the individual resources formed and stabilized in youth, as well as in the investigation of the consequences of different partnership trajectory patterns on individual well-being. For these objectives, a high demand on the data is required, as prospective data at the beginning of the partnership biography are needed, as well as data on current life dimensions and the detailed partnership history. The German LifE Study provides this particular data structure as it examines life courses of more than 1,300 individuals from adolescence to middle adulthood. With regard to the overall aim of this dissertation, the main conclusion is that early life conditions, experiences, and resources influence the dynamics of individual partnership trajectories. The results illustrate that youth matters and that characteristics and resources anchored in youth influence the timing of early status passages, which sets individuals on specific life paths. However, in addition to personal and social resources, partnership trajectories were also significantly influenced by individuals’ sociodemographic placement. Additionally, individual resources are also linked to the overall turbulence or stability of partnership trajectories. This overall dynamic, which is reflected in different partnership patterns, influences individual well-being, with stability being associated with greater satisfaction, and instability (women), or permanent singlehood (men), having a negative impact on well-being. My analyses contribute to life course research by examining path dependency against the background of various individual factors (socio-structural and psychological characteristics) to model decision-making processes in partnerships in more detail. They do so by including also non-cohabitational union types in the analyses, by accounting for pre-trajectory life conditions and resources, and, most importantly, by modeling the partnership trajectory in a holistic and dynamic perspective, applying this perspective to appropriate and modern statistical methods on a unique dataset.
Das Totenfürsorgerecht
(2022)
Die vorliegende Untersuchung befasst sich mit den allgegenwärtigen Fragen, welches rechtliche Schicksal der menschliche Körper nach dem Tod nimmt, ob der Leichnam vererbt wird und wer in welchem Umfang über ihn bestimmen darf. Die Autorin gelangt zu dem Ergebnis, dass das Totenfürsorgerecht als wesentlicher Bestandteil des - im Grundgesetz als Staatszielbestimmung zu verankernden - sog. postmortalen Persönlichkeitsschutzes auf die Wahrung der Pietät ziele und zuvörderst dem Willen des Verstorbenen verpflichtet sei. Bei unbekanntem Verstorbenenwillen dürfe der Totenfürsorgeberechtigte aber in einigen wenigen Bereichen auch eigene Entscheidungen über den ihm anvertrauten Leichnam treffen. Der Umgang mit dem Leichnam lasse sich bislang keinem bekannten Rechtsinstitut zuordnen und stelle Gewohnheitsrecht dar. Gegenwärtig herrsche Rechtsunsicherheit. Zur Behebung des gesetzgeberischen Defizits schlägt die Autorin ein Bundesgesetz vor und unterbreitet hierfür einen Gesetzesvorschlag.