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Nuclear migration during growth and development is a conserved phenomenon among many eukaryotic species. In Arabidopsis, movement of the nucleus is important for root hair growth, but the detailed mechanism behind this movement is not well known. Previous studies in different cell types have reported that the myosin XI-I motor protein is responsible for this nuclear movement by attaching to the nuclear transmembrane protein complex WIT1/WIT2. Here, we analyzed nuclear movement in growing root hairs of wild-type, myosin xi-i, and wit1 wit2 Arabidopsis lines in the presence of actin and microtubule-disrupting inhibitors to determine the individual effects of actin filaments and microtubules on nuclear movement. We discovered that forward nuclear movement during root hair growth can occur in the absence of myosin XI-I, suggesting the presence of an alternative actin-based mechanism that mediates rapid nuclear displacements. By quantifying nuclear movements with high temporal resolution during the initial phase of inhibitor treatment, we determined that microtubules work to dampen erratic nuclear movements during root hair growth. We also observed microtubule-dependent backwards nuclear movement when actin filaments were impaired in the absence of myosin XI-I, indicating the presence of complex interactions between the cytoskeletal arrays during nuclear movements in growing root hairs.

The generated power and thrust of a wind turbine strongly depend on the flow field around the turbine. In the present study, three different inflow methods, i.e., a time series (TS) from large eddy simulation (LES) of atmospheric boundary layer flow field, a synthetic turbulent flow field using the Mann model (MM), and a steady-state mean wind profile with shear, are integrated with the free vortex filament wake method to investigate the effect of wind field generation methods on the wind turbine performance where the impact of the turbine and the trailing wake vortices on the turbulent flow fields is ignored. For this purpose, an in-house vortex lattice free wake (VLFW) code is developed and used to predict the aerodynamic loads on rotor blades. The NREL 5-MW reference wind turbine is used for the VLFW simulations. For a fair assessment of different inflow generation methods on power production of a wind turbine, it is not sufficient that the generated wind fields employed in the TS and MM methods have the same streamwise mean velocity and turbulence intensity at hub height. Instead, the generated inflows must have equivalent power-spectral densities especially at low frequencies since the rotor blades essentially respond to the large-scale fluctuations (macroscopic scales) rather than small-scale fluctuations (microscopic scales). A faster energy decay rate of LES inflow leads to a higher energy content in the TS method at low frequencies (associated with the macroscopic dynamics of the rotor blades). This extra kinetic energy results in a slightly higher mean power production while using the TS method although the inflow conditions at hub height/rotor plane are the same for both the TS and MM methods. Moreover, the impact of simulation time (the length of time integration) on the power production of a wind turbine (exposed to an unsteady inflow) must be taken into account. A short simulation time remarkably affects the mean wind speed over the rotor area for identical turbulent inflows. For Taylor’s hypothesis application using a single LES flow field, the results show a significant difference in the mean powers corresponding to the different realizations due to large turbulent fluctuations.

Südasien, Bd. 38 Nr. 2 (2018): Adivasi und Indigenität

Dissertation - University of Veterinary Medicine Vienna - 2021, Cyclin-dependent kinase 6 (CDK6) and its close homolog cyclin-dependent kinase 4 (CDK4) are classic cell cycle kinases that become catalytically active upon binding their respective regulatory subunits, the cyclins, to allow G1/S phase progression. Components of these cell cycle associated complexes are frequently altered in various types of cancer with elevated CDK6 expression levels being common in hematological malignancies. Over the last years, an additional role for CDK6 as transcriptional regulator has been identified. As such, CDK6 modulates expression of numerous genes involved in proliferation, angiogenesis and survival. In this thesis, the contribution of CDK6 to epigenetic regulation has been studied. We demonstrate a direct effect of CDK6 on DNA methylation in BCR- ABL transformed cells and identify a correlation between CDK6 and DNA methyltransferase (DNMT) expression in ALL patients. ChIP-Seq analysis uncovered binding of CDK6 to specific genomic regions associated with DNMTs. Combined ATAC -Seq, RNA-Seq and chromatome analysis showed a reduced chromatin accessibility in CDK6-deficient BCR-ABL+ cells for the regions encoding DNMTs, which resulted in lower gene and protein expression of DNMT3B. Motif analysis indicates that CDK6 cooperates with ETS factors to control DNMT3B levels. Reduced- representation bisulfite sequencing confirmed a reversible effect of CDK6 on cell-line specific DNA methylation patterns. Our results uncover CDK6 as regulator of the DNA methylation process in transformed cells. In the second part of my thesis, we assigned CDK6 a critical role during oncogene-induced stress. During BCR-ABL-induced transformation, CDK6 operates as a pro- survival factor counteracting p53-mediated responses. Cells lacking kinase activity of CDK6 displayed a severely impaired capacity to form stable leukemic cell lines. To overcome the inability to immortalize, these cells were forced to mutate or delete p53. Our observations in the murine system were reflected in human hematopoietic malignancies, where we verified an inverse correlation between CDK6 expression levels and the incidence of p53 mutations. In summary, my studies underline the versatile and complex functions of CDK6., Dissertation - Veterinärmedizinische Universität Wien - 2021, Die Cyclin-abhängige Kinase 6 (CDK6) und 4 (CDK4) sind klassische Zellzykluskinasen, die durch Bindung an ihre jeweiligen regulatorischen Untereinheiten, die Cykline, die Zellen durch die G1 Phase des Zellzyklus treiben. Komponenten dieser Zellzyklus -assozierten Komplexe sind häufig in diversen Krebsarten verändert, wobei erhöhte CDK6 Ex pressionswerte insbesondere in hämatologischen Erkrankungen vermehrt beobachtet wurden. Erkenntnisse der letzten Jahre haben gezeigt, dass CDK6 zusätzlich als transkriptioneller Regulator fungiert. CDK6 moduliert die Expression zahlreicher Gene, die für die Proliferation, Angiogenese und das Überleben der Zelle verantwortlich sind. Diese Dissertation befasst sich mit CDK6 und Epigenetik und zeigt, dass CDK6 einen direkten Effekt auf die DNA Methylierung in BCR- ABL transformierten Zellen hat. Wir konnten eine Korrelation zwischen CDK6 und DNA Methyltransferasen (DNMTs) in ALL Patienten identifizieren. Die ChIP -Seq Analyse deckte die Bindung von CDK6 an spezifische genomische Regionen, die mit DNMTs assoziert sind, auf. Kombinierte ATAC-Seq, RNA-Seq und Chromatome Analysen zeigten eine stark reduzierte Chromatinzugänglichkeit für DNMT kodierende Regionen in CDK6-defizienten BCR-ABL+ Zellen, die in einer reduzierten Gen- und Proteinexpression von DNMT3B resultierten. Die Motivanalyse weist daraufhin, dass CDK6 mit ETS-Faktoren interagiert, um DNMT3B zu regulieren. Die RRBS Analyse bestätigte einen reversiblen Effekt von CDK6 auf das zelllinienspezifische DNA Methylierungsmuster. Unsere Resultate definieren CDK6 als Regulator des DNA -Methylierungsprozesses in transformierten Zellen. Im zweiten Teil meiner Dissertation zeigen wir, dass CDK6 eine kritische Funktion während Onkogen-induziertem Stress einnimmt. Während der BCR-ABL induzierten Transformation agiert CDK6 als überlebensfördernder Faktor, der p53-mediierten Antworten entgegenwirkt. Zellen, denen die Kinasefunktion von CDK6 fehlte, wiesen eine starke Beeinträchtigung in der Fähigkeit stabile leukämische Zelllinien auszubilden auf. Um dieses Defizit auszugleichen, sind die Zellen gezwungen p53 zu mutieren oder zu deletieren. Unsere Beobachtungen im murinen System konnten in humanen hämatopoetischen Erkrankungen bestätigt werden. Eine inverse Korrelation zwischen der Expression von CDK6 und dem Auftreten von p53 Mutationen ist nachweisbar.

BackgroundThe common dragonet, Callionymus lyra, is one of three Callionymus species inhabiting the North Sea. All three species show strong sexual dimorphism. The males show strong morphological differentiation, e.g., species-specific colouration and size relations, while the females of different species have few distinguishing characters. Callionymus belongs to the ‘benthic associated clade’ of the order Syngnathiformes. The ‘benthic associated clade’ so far is not represented by genome data and serves as an important outgroup to understand the morphological transformation in ‘long-snouted’ syngnatiforms such as seahorses and pipefishes.FindingsHere, we present the chromosome-level genome assembly of C. lyra. We applied Oxford Nanopore Technologies’ long-read sequencing, short-read DNBseq, and proximity-ligation-based scaffolding to generate a high-quality genome assembly. The resulting assembly has a contig N50 of 2.2 Mbp, a scaffold N50 of 26.7 Mbp. The total assembly length is 568.7 Mbp, of which over 538 Mbp were scaffolded into 19 chromosome-length scaffolds. The identification of 94.5% of complete BUSCO genes indicates high assembly completeness. Additionally, we sequenced and assembled a multi-tissue transcriptome with a total length of 255.5 Mbp that was used to aid the annotation of the genome assembly. The annotation resulted in 19,849 annotated transcripts and identified a repeat content of 27.66%.ConclusionsThe chromosome-level assembly of C. lyra provides a high-quality reference genome for future population genomic, phylogenomic, and phylogeographic analyses.

Cytoplasmic streaming is characterized by the rapid movement of organelles and other cellular components throughout the cell. In plants, the process depends on actin filaments and myosin motor proteins and plays an important role in cell growth. Detailed quantification of organelle movements can yield important insights into the dynamics of intracellular organization and its functional aspects. This quantification is hindered by a lack of knowledge of the different types of movements and generic tracking algorithms that yield erroneous output. This protocol provides a step-by-step guide to the detection and measurement of organelle motility as well as a description of additional analysis steps distinguishing undirected, diffusion-like movements from directional movements along the actin cytoskeleton.

Cytoplasmic streaming is characterized by the rapid movement of organelles and other cellular components throughout the cell. In plants, the process depends on actin filaments and myosin motor proteins and plays an important role in cell growth. Detailed quantification of organelle movements can yield important insights into the dynamics of intracellular organization and its functional aspects. This quantification is hindered by a lack of knowledge of the different types of movements and generic tracking algorithms that yield erroneous output. This protocol provides a step-by-step guide to the detection and measurement of organelle motility as well as a description of additional analysis steps distinguishing undirected, diffusion-like movements from directional movements along the actin cytoskeleton.

Seit den Protesten rund um den Bau des Bahnprojekts Stuttgart 21 werden Politik und Verwaltung auf kommunaler Ebene mit beständig stärker werdenden Beteiligungswünschen der Bürgerinnen und Bürger konfrontiert. Aber auch in der internationalen Partizipationsforschung taucht der Begriff der Bürgerbeteiligung in den letzten zehn bis 15 Jahren immer beharrlicher auf. In direkter Reaktion hierauf befasst sich die Stadt Heidelberg, als eine der ersten Kommunen deutschlandweit, seit dem Jahr 2010 intensiv mit der Beteiligung ihrer Bürgerinnen und Bürger am politischen Entscheidungsfindungsprozess. Die deutschsprachige Forschung allerdings konzentriert sich lediglich auf die inhaltliche Ausgestaltung von Bürgerbeteiligung anhand einer Vielzahl an Handbüchern, Checklisten und Leitlinien für die kommunale Praxis. Wissenschaftliche Überlegungen zu deren Wirksamkeit werden so gut wie gar nicht angestellt. Die Dissertation „Wirkung der Mitwirkung - Messung der Effektivität von Bürgerbeteiligung am Beispiel der Stadt Heidelberg -“ von Pascal Nebenführ geht aufgrund dessen anhand einer quantitativen Datenanalyse der Fragestellung nach, welchen Grad an Effektivität Bürgerbeteiligung in der Stadt Heidelberg innehat. Der Autor entwickelt hierfür zuerst eine an Benjamin Barbers (1994) starker Demokratie orientierte normative Definition von Bürgerbeteiligung. Anschließend werden, bezugnehmend auf die Publikationen von Archon Fung (2003) sowie Lyn Carson und Phillip Hart (2005), Beurteilungsdimensionen effektiver Bürgerbeteiligung (Empowerment, Efficacy, Inclusion und Quality) entworfen. Darauf aufbauend konstruiert der Autor ein empirisches Messmodell, welches im letzten Teil der Arbeit anhand von Primär- und Sekundärdaten auf die Stadt Heidelberg angewandt wird. Als Ergebnis der Arbeit zeigt sich unter anderem, dass die Effektivität von Partizipationsverfahren von vielen unterschiedlichen Einflussfaktoren und Parametern abhängig ist, die nicht alle einer Messung zugeführt werden können. Zudem wird deutlich, dass Kommunen vorrangig bei den Beurteilungsdimensionen Inclusion und Quality ansetzen müssen, um die Wirksamkeit von Bürgerbeteiligung zu erhöhen. Beispielsweise durch den Partizipationsprozess begleitende Maßnahmen wie eine aleatorische Teilnehmerauswahl oder die Zahlung von Aufwandsentschädigungen. Der Autor kommt abschließend zu der Überzeugung, dass die Kombination aus normativen und quantitativen Untersuchungen das Verständnis von Bürgerbeteiligung auf kommunaler Ebene erheblich verbessern wird.

Summary Rice blast disease, caused by the fungus Magnaporthe oryzae, is the most devastating disease of rice. In our ongoing characterization of the defence mechanisms of rice plants against M. oryzae, a terpene synthase gene OsTPS19 was identified as a candidate defence gene. Here, we report the functional characterization of OsTPS19, which is up‐regulated by M. oryzae infection. Overexpression of OsTPS19 in rice plants enhanced resistance against M. oryzae, while OsTPS19 RNAi lines were more susceptible to the pathogen. Metabolic analysis revealed that the production of a monoterpene (S)‐limonene was increased and decreased in OsTPS19 overexpression and RNAi lines, respectively, suggesting that OsTPS19 functions as a limonene synthase in planta. This notion was further supported by in vitro enzyme assays with recombinant OsTPS19, in which OsTPS19 had both sesquiterpene activity and monoterpene synthase activity, with limonene as a major product. Furthermore, in a subcellular localization experiment, OsTPS19 was localized in plastids. OsTPS19 has a highly homologous paralog, OsTPS20, which likely resulted from a recent gene duplication event. We found that the variation in OsTPS19 and OsTPS20 enzyme activities was determined by a single amino acid in the active site cavity. The expression of OsTPS20 was not affected by M. oryzae infection. This indicates functional divergence of OsTPS19 and OsTPS20. Lastly, (S)‐limonene inhibited the germination of M. oryzae spores in vitro. OsTPS19 was determined to function as an (S)‐limonene synthase in rice and plays a role in defence against M. oryzae, at least partly, by inhibiting spore germination.

The cytoskeleton is the main organizing principle that defines not only the distribution of cellular components within cells but also the overall shape and growth pattern of cells and entire multicellular organisms. This function is particularly evident in plant cells, where, for example, the

Microscopy imaging allows detailed observations of intracellular movements and the acquisition of large datasets that can be fully analyzed only by automated algorithms. Here, we develop a computational method for the automatic identification and reconstruction of trajectories followed by subcellular particles captured in microscopy image data. The method operates on stacks of raw image data and computes the complete set of contained trajectories. The method utilizes topological data analysis and standard image processing techniques and makes no assumptions about the underlying dynamics besides continuity. We test the developed method successfully against artificial and experimental datasets. Application of the method on the experimental data reveals good agreement with manual tracking and benchmarking yields performance scores competitive to the existing state-of-the-art tracking methods.