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Changes in reproduction mediate the effects of climate change and grassland management on plant population dynamics
Get PDFClimate change is one of the largest threats to grassland plant species, which can be modified by land management. Although climate change and land management are expected to separately and interactively influence plant demography, this has been rarely considered in climate change experiments. We used a large-scale experiment in central Germany to quantify the effects of grassland management, climate change, and their joint effect on the demography and population growth rate of 11 plant species all native to this temperate grassland ecosystem. We parameterized integral projection models with five years of demographic data to project population growth rate. We hypothesized that plant populations perform better in the ambient than in the future climate treatment that creates hotter and drier summer conditions. Further, we hypothesized that plant performance interactively responds to climate and land management in a species-specific manner based on the drought, mowing, and grazing tolerances as well as the flowering phenology of each species. Due to extreme drought events, over half of our study species went quasi extinct, which highlights how extreme climate events can influence long-term experimental results. We found no consistent support for our expectation that plants perform better in ambient compared with future climate conditions. However, several species showed interactive responses to the treatments, indicating that optimal management strategies for plant performance are expected to shift with climate change. Changes in population growth rates of these species across treatments were mostly due to changes in plant reproduction. Experiments combined with measuring plant demographic responses provide a way to isolate the effects of different drivers on the long-term persistence of species and to identify the demographic vital rates that are critical to manage in the future. Our study suggests that it will become increasingly difficult to maintain species with preferences for moister soil conditions, and that climate and land use can interactively alter demographic responses of the remaining grassland species
Regulation of cellular function by mineralocorticoid receptors
Get PDFThe mineralocorticoid receptor (MR), activated by aldosterone, influences renal physiology and also contributes to aging and cardiovascular pathology. This thesis investigates how MR activation alters cellular function, focusing on metabolic shifts, ER stress, autophagy, and cell death in an inducible HEK-MR model. Aldosterone stimulation increased glycolysis and triggered stress-response pathways. PDK4 was identified as an MR-target gene potentially involved in glucose metabolism and stress adaptation. Additionally, nitrosative stress enhanced MR translocation and induced the expression of genes associated with cardiac disease. These findings suggest elevated MR activity drives cellular changes contributing to MR-related pathophysiolog
Neuroplastin and Plasma Membrane Ca2+ ATPases in murine macrophages : a phenotypical analysis
Get PDFNeuroplastin, an immunoglobulin superfamily transmembrane protein, has been implicated
in synaptic plasticity and learning and memory. Moreover, Neuroplastin has been established
as a close interacting partner of Plasma Membrane Calcium ATPases (PMCAs). This interaction
stabilizes PMCAs, and thus, plays a critical role in maintaining Ca2+ homeostasis within cells.
Recent studies have addressed the roles of Neuroplastin-PMCA in immune cells, for which
Ca2+ plays a crucial role. While the role of Ca2+ is well-defined in T and B lymphocyte activation,
its precise function and the mechanisms of its entry and exit in macrophages remain an active
area of research. In this study, I first addressed the relevance of Neuroplastin and PMCA
(isoform 1) for Ca2+ homeostasis in macrophages based on knockout mutants. PMCA1 rather
than Neuroplastin emerged as vital for regulating intracellular Ca2+ levels. Next, I performed
a comparative analysis of signaling, cytokine production, and metabolism in Neuroplastin and
PMCA1 knockout macrophages after M1 polarization with IFNg/LPS. Interestingly, despite loss
of >70% of PMCAs, Neuroplastin knockout macrophages showed normal canonical signaling
(STAT1, NF-kB, ERK1/2) and no or little differences in cytokine production along with
moderate elevation of Ca2+ in the ER as well as subdued glycolysis. In contrast, PMCA1
knockout macrophages demonstrated elevated basal and stored Ca2+ levels, upregulated
ERK1/2 signaling upon stimulation, and significantly upregulated cytokine production after
M1 polarization. Also, these macrophages showed elevated OXPHOS and glycolysis (after M1
polarization). These findings provide an understanding of the role of Neuroplastin and PMCA
in macrophage function, shedding light on the underlying fundamental difference between a
Neuroplastin and a PMCA knockout macrophage. This study also involved a high-throughput
RNAseq analysis of PMCA1 knockout macrophages versus controls before and after
stimulation. About 2 to 3% of all genes displayed differential expression in the absence of
PMCA1 upon stimulation. Within this fraction, genes related to NF-kB- and Ca2+-signaling, as
well as to autoimmune diseases, were found enriched. Together, these findings provide
valuable insights into the underlying mechanisms enabling macrophages to survive disturbed
Ca2+ homeostasis and maintain polarization within limits. This knowledge could be harnessed
to develop strategies for managing conditions associated with disrupted Ca2+ homeostasis,
such as degenerative processes and inflammatory diseases.Neuroplastin, ein Transmembranprotein der Immunglobulin-Superfamilie, ist an der
synaptischen Plastizität sowie an Lernen und Gedächtnis beteiligt. Darüber hinaus hat sich
Neuroplastin als enger Interaktionspartner von Plasmamembran-Calcium-ATPasen (PMCAs)
erwiesen. Diese Interaktion stabilisiert die PMCAs und spielt somit eine wichtige Rolle bei der
Aufrechterhaltung der intrazellulären Ca2+-Homöostase. Neuere Studien haben sich mit der
Rolle von Neuroplastin-PMCA in Immunzellen befasst, für die Ca2+ eine entscheidende Rolle
spielt. Während die Rolle von Ca2+ bei der Aktivierung von T- und B-Lymphozyten gut definiert
ist, werden seine genaue Funktion und die Mechanismen seines Eintritts und Austritts in
Makrophagen nach wie vor aktiv beforscht. In dieser Studie habe ich zunächst die Bedeutung
von Neuroplastin und PMCA (Isoform 1) für die Ca2+-Homöostase in Makrophagen anhand von
Knockout-Mutanten untersucht. Es stellte sich heraus, dass PMCA1, jedoch nicht
Neuroplastin, für die Regulierung des intrazellulären Ca2+-Spiegels entscheidend ist. Als
nächstes führte ich eine vergleichende Analyse der Signalübertragung, der Zytokinproduktion
und des Stoffwechsels in Neuroplastin- und PMCA1-Knockout-Makrophagen nach M1-
Polarisierung mit IFNg/LPS durch. Interessanterweise zeigten Neuroplastin-Knockout-
Makrophagen trotz des Verlusts von mehr als 70 % der PMCAs eine normale kanonische
Signalübertragung (STAT1, NF-kB, ERK1/2) und keine oder nur geringe Unterschiede in der
Zytokinproduktion sowie eine moderate Erhöhung von Ca2+ im ER und eine gedämpfte
Glykolyse. Im Gegensatz dazu zeigten PMCA1-Knockout-Makrophagen sowohl erhöhtes
basales Ca2+ als auch deutlich erhöhtes Ca2+ im ER-Speicher und zudem eine hochregulierte
ERK1/2-Signalgebung nach Stimulation und eine signifikant erhöhte Zytokinproduktion nach
M1-Polarisierung. Darüber hinaus zeigten diese Makrophagen erhöhte OXPHOS als auch
Glykolyse (nach M1-Polarisierung). Diese Ergebnisse ermöglichen ein Verständnis der Rolle
von Neuroplastin und PMCA bei der Makrophagenfunktion und belegen den grundlegenden
Unterschied zwischen Neuroplastin- und PMCA-Knockout-Makrophagen. Die vorliegende
Studie enthält auch eine Hochdurchsatz-RNAseq-Analyse von PMCA1-Knockout-
Makrophagen im Vergleich zu Kontrollen, vor und nach Stimulation. Etwa 2 bis 3 % aller Gene
zeigten eine unterschiedliche Expression in Abwesenheit von PMCA1 nach Stimulation.
Innerhalb dieser Fraktion sind Gene angereichert, die mit NF-kB - und Ca2+-Signalen sowie mit
Autoimmunkrankheiten in Verbindung stehen. Zusammengenommen bieten diese Ergebnisse wertvolle Einblicke in die zugrundeliegenden Mechanismen, die es Makrophagen
ermöglichen, eine gestörte Ca2+-Homöostase zu überleben und ihre Polarisierung in Grenzen
zu halten. Dieses Wissen könnte genutzt werden, um Strategien zur Behandlung von
Zuständen zu entwickeln, die mit einer gestörten Ca2+-Homöostase einhergehen, wie z.B.
degenerative Prozesse und Entzündungskrankheiten
Optimierung automatisierter Analysen von Ultraschallaufnahmen mittel Bild-Segmentierung am Fallbeispiel des Breast Ultrasound Images Dataset und der U-Net-Architektur
Get PDFZiel der Arbeit ist es, eine nachvollziehbare Empfehlung zur optimalen Konfiguration eines U-Net-Modells für die Bildsegmentierung zur Erkennung von Tumoren zu entwickeln. Für die Untersuchung wird der Breast Ultrasound Image (BUSI)-Datensatz genutzt
WHIRLY1 regulates aliphatic glucosinolate biosynthesis in early seedling development of arabidopsis
Get PDFWHIRLY1 belongs to a family of plant-specific transcription factors capable of binding DNA or RNA in all three plant cell compartments that contain genetic materials. In Arabidopsis thaliana, WHIRLY1 has been studied at the later stages of plant development, including flowering and leaf senescence, as well as in biotic and abiotic stress responses. In this study, WHIRLY1 knockout mutants of A. thaliana were prepared by CRISPR/Cas9-mediated genome editing to investigate the role of WHIRLY1 during early seedling development. The loss-of-function of WHIRLY1 in 5-day-old seedlings did not cause differences in the phenotype and the photosynthetic performance of the emerging cotyledons compared with the wild type. Nevertheless, comparative RNA sequencing analysis revealed that the knockout of WHIRLY1 affected the expression of a small but specific set of genes during this critical phase of development. About 110 genes were found to be significantly deregulated in the knockout mutant, wherein several genes involved in the early steps of aliphatic glucosinolate (GSL) biosynthesis were suppressed compared with wild-type plants. The downregulation of these genes in WHIRLY1 knockout lines led to decreased GSL contents in seedlings and in seeds. Since GSL catabolism mediated by myrosinases was not altered during seed-to-seedling transition, the results suggest that AtWHIRLY1 plays a major role in modulation of aliphatic GSL biosynthesis during early seedling development. In addition, phylogenetic analysis revealed a coincidence between the evolution of methionine-derived aliphatic GSLs and the addition of a new WHIRLY in core families of the plant order Brassicales
A barley pan-transcriptome reveals layers of genotype-dependent transcriptional complexity
Get PDFA pan-transcriptome describes the transcriptional and post-transcriptional consequences of genome diversity from multiple individuals within a species. We developed a barley pan-transcriptome using 20 inbred genotypes representing domesticated barley diversity by generating and analyzing short- and long-read RNA-sequencing datasets from multiple tissues. To overcome single reference bias in transcript quantification, we constructed genotype-specific reference transcript datasets (RTDs) and integrated these into a linear pan-genome framework to create a pan-RTD, allowing transcript categorization as core, shell or cloud. Focusing on the core (expressed in all genotypes), we observed significant transcript abundance variation among tissues and between genotypes driven partly by RNA processing, gene copy number, structural rearrangements and conservation of promotor motifs. Network analyses revealed conserved co-expression module::tissue correlations and frequent functional diversification. To complement the pan-transcriptome, we constructed a comprehensive cultivar (cv.) Morex gene-expression atlas and illustrate how these combined datasets can be used to guide biological inquiry
Effect of Ga variation on the bulk and grain-boundary properties of Cu(In,Ga)Se₂ absorbers in thin-film solar cells and their impacts on open-circuit voltage losses
Get PDFPolycrystalline widegap Cu(In,Ga)Se2 (CIGSe) absorbers for top cells in photovoltaic tandem devices can be synthesized via [Ga]/([Ga] + [In]) (GGI) ratios of > 0.5. However, the power conversion efficiencies of such high-GGI devices are smaller than those of the record cells with GGI 0.5, which can be attributed to low bulk lifetimes and enhanced recombination at GBs in CIGSe absorbers in this compositional range
Industrie 4.0-angepasste Datenverkehrskonzepte für industrielle 5G-TSN-Netzwerke
Get PDFTrends und Weiterentwicklungen von Industrie 4.0 in Richtung einer ständig wandelbaren Fabrik
führen zu mehr Mobilität und Flexibilität der einzelnen Teilnehmer in der Fabrikhalle. Dadurch steigen
die Anforderungen an die drahtlose Kommunikation. Der entscheidende Faktor ist dabei eine hoch-
zuverlässige Kommunikation mit geringer Latenz, wie sie z. B. Anwendungsfälle der kooperativen
mobilen Robotik fordern.
5G-Mobilfunk bietet der industriellen Automatisierung eine alternative drahtlose Technologie zu
Bluetooth und (Industrial) WLAN, bei der industrielle Anforderungen bereits in der Standardisierung
berücksichtigt wurden. Time-Sensitive Networking (TSN) umfasst Mechanismen für Echtzeit und
Determinismus über Ethernet. Die Kombination beider Technologien soll hybride kabelgebundene
und drahtlose Netzwerke für cyber-physische Systeme (CPS) im Sinne von Industrie 4.0 ermöglichen.
Um 5G in TSN zu integrieren, spezifizierte die globale Standardisierungsorganisation für Mobilfunk,
3rd Generation Partnership Project (3GPP), das Modell des 5G-Systems als virtuelle TSN-Bridge. Diese
enthält TSN-Übersetzungsfunktionen, die Mechanismen zur Zeitsynchronisation und Steuerung der
Dienstgüte, engl. Quality of Service (QoS), von TSN auf 5G abbilden.
Allerdings sind 5G und TSN lediglich in Testumgebungen praktisch implementiert, da die
Technologiereife bislang nicht für einen produktiven Einsatz ausreicht. Zudem sind viele Aspekte des
Integrationskonzepts für 5G und TSN noch ungeklärt. Bislang liegt der Forschungsschwerpunkt auf der
Zeitsynchronisation von TSN über 5G, was eine Grundvoraussetzung für die deterministische
Datenübertragung bildet. Fundierte wissenschaftliche Untersuchungen zur Zuordnung der jeweiligen
Parameter und Mechanismen für ein gemeinsames QoS-Modell bzw. Datenverkehrskonzept stehen
weiterhin aus.
Zur Lösung dieser Problemstellung gilt es die folgenden Fragen zu klären: Wie lassen sich TSN als
kabelgebundene und 5G-Mobilfunk als drahtlose Kommunikationsstandards so kombinieren, dass ein
für Industrie 4.0 geeignetes Datenverkehrskonzept entsteht? Nach welchen Anforderungen lassen
sich Anwendungsfälle für die Integration von 5G in TSN im Kontext von Industrie 4.0 charakterisieren?
Welche Faktoren spielen für eine einsatzfähige Lösung einer vollintegrierten industriellen 5G-TSN-
Netzwerkarchitektur im Hinblick auf Industrie 4.0 eine Rolle? Wie sieht ein ganzheitliches
Datenverkehrskonzept basierend auf den Kommunikations-anforderungen der Applikationen
kombiniert mit der Netzwerkarchitektur aus? Inwiefern ist dieses Datenverkehrskonzept umsetzbar?
Die vorliegende Dissertation beschäftigt sich mit diesen Forschungsfragen aus der dafür notwendigen
ganzheitlichen Sicht. Dafür werden einerseits Standards wie IEC/IEEE 60802 (TSN-Profil für die
industrielle Automatisierung) sowie das 5G Bridge-Modell und das 5G QoS-Modell aus 3GPP
herangezogen. Andererseits werden Informationen über repräsentativen Datenverkehr in
industriellen Automatisierungsnetzwerken benötigt. In dieser Dissertation werden die Eigenschaften
und Unterschiede von 5G und TSN beim Umgang mit QoS für bestimmten Datenverkehr analysiert
und mögliche Lösungen aufgezeigt, um die jeweiligen QoS-Parameter aufeinander abzubilden. Aus der
Analyse von Datenverkehrsmodellen wird ein Datenverkehrskonzept entwickelt, welches mehrere
Konfigurationen mit unterschiedlicher Komplexität und Flexibilität umfasst. Die Validierung des
Datenverkehrskonzepts erfolgt in drei Schritten anhand von Messungen an einem realen
Versuchsaufbau, analytischen Berechnungen sowie Simulationen.
Die Ergebnisse dieser Dissertation tragen zur Entwicklung eines 5G QoS-Modells für die Integration in
TSN in Industrie 4.0 bei und dienen als Grundlage für die Konkretisierung der TSN-
Übersetzungsfunktionen im 5G-System.Trends and enhancements of Industry 4.0 towards a constantly adaptive factory lead to more mobility
and flexibility on the factory floor. Consequently, requirements on wireless communication increase.
The decisive factor is the demand for highly reliable communication with low latency, as required by
cooperative mobile robotics use cases, for example.
5G mobile radio offers industrial automation an alternative wireless technology to Bluetooth and
(Industrial) Wi-Fi, in which industrial requirements have already been taken into account in the
standardization process. Time-Sensitive Networking (TSN) includes mechanisms for real-time and
determinism via Ethernet. The combination of both technologies should enable hybrid wired and
wireless networks for cyber-physical systems (CPS) in the sense of Industry 4.0. In order to integrate
5G into TSN, the global standardization organization for mobile radio communications, 3rd Generation
Partnership Project (3GPP), specified the model of the 5G system as a virtual TSN bridge. This contains
TSN translator functions that map mechanisms for time synchronization and Quality of
Service (QoS) control from TSN to 5G.
However, 5G and TSN have only been practically implemented in test environments, as the
technological maturity is not yet sufficient for productive use. In addition, many aspects of the
integration concept for 5G and TSN are still unclear. So far, research has focused on the time
synchronization of TSN over 5G, which is a basic requirement for deterministic data transmission.
Sound scientific studies on the assignment of the respective parameters and mechanisms for a
common QoS model or data traffic concept are still pending.
To solve this problem, the following questions need to be clarified: How can TSN as a wired
communication standard and 5G mobile radio as a wireless communication standard be combined to
create a data traffic concept suitable for Industry 4.0? What requirements can be used to characterize
use cases for the integration of 5G in TSN in the context of Industry 4.0? What factors affect a viable
solution for a fully integrated industrial 5G-TSN network architecture with regard to Industry 4.0?
What does a holistic data traffic concept based on the communication requirements of the
applications combined with the network architecture look like? To what extent can this data
traffic concept be implemented?
This doctoral thesis deals with these research questions from the necessary holistic perspective. On
the one hand, standards such as IEC/IEEE 60802 (TSN profile for industrial automation) as well as the
3GPP bridge and QoS models for 5G are used. On the other hand, information on representative data
traffic in industrial automation networks is required. This doctoral thesis analyzes the characteristics
and differences of 5G and TSN when dealing with QoS for specific data traffic and identifies possible
solutions to map the individual QoS parameters to each other. Based on the analysis of data traffic
models, a data traffic concept is developed, which includes multiple configurations with different
complexity and flexibility. The validation of the data traffic concept is carried out in three steps using
measurements on a real test setup, analytical calculations and simulations.
The results of this doctoral thesis contribute to the development of a 5G QoS model for integration
into TSN in Industry 4.0 and serve as a basis for the concretization of the TSN translator functions in
the 5G system
Carbon‐centered reactivity in carbodiphosphorane-based ligands allowing for redox-non-innocent ligand/ligand dual bond-activation
Get PDFA pronounced nucleophilicity in combination with a distinct redox non-innocence is a unique feature of a
coordinated ligand, which in the current case, leads to unprecedented carbon-centered reactivity patterns: A
carbodiphosphorane-based (CDP) pincer-type rhodium complex allows to cleave two C–Cl-bonds of geminal dichlorides
via two consecutive SN2-type oxidative additions resulting in the formation of a stabilized carbene fragment. In the
presence of a suitable reductant the carbene fragment can even be converted into olefines or hydrodehalogenation
products in a catalytic reaction. The developed method can also be used to convert chlorofluorocarbons (CFCs) such as
CH2ClF to fluoromethane and methane. The strong nucleophilic character of coordinated CDPs is also reflected in the
low potential for oxidation, which favors radical reactivity and gives rise to an unique cationic C-centered radical CDP
ligand, which is capable of a carbon-centered dihydrogen activation, following an unprecedented radical mechanism
involving ligand/ligand-cooperativity (LLC)