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Amtliche Bekanntmachungen, 55. Jahrgang, Nr. 21
No full textAkkreditierungsbeschluss vom 4. März 2025 Comparative Theological Studies (M.A.) vom 14. April 202
Development and Characterization of an Irradiation Site for Radiation Damage Studies of the ATLAS ITk Pixel Detector
No full textSilicon pixel detectors build the foundation of particle tracking in high-rate environments, delivering high spatial resolution while sustaining hit rates of up to several GHz cm-2. In the field of modern-day high-energy particle physics, pixel detectors are operated in extreme conditions, marking the frontier of radiation levels for microelectronics. In this environment, silicon devices suffer from radiation-induced damage and subsequent performance degradation of the detector components. To allow for research, development and verification of novel tracking detectors for extreme radiation applications, irradiation sites are a crucial part of the infrastructure.
In this work, a novel irradiation site for silicon detectors has been developed, characterized and commissioned at the University of Bonn. The site is located at the Bonn Isochronous Cyclotron (BIC) facility and operated with nominally 14 MeV protons with beam currents of up to 1 µA. Devices Under Test (DUTs) are situated in a thermally-insulated box at temperatures of ≤ −20 °C while being moved through the beam on a row-based meander pattern, achieving a uniform fluence distribution. A set of custom diagnostics facilitate non-destructive online beam monitoring at the site with a relative uncertainty of ≤ 2 %. The beam monitoring capabilities enable a purely beam-based, on- and offline dosimetry approach and beam-driven irradiation routine that result in highly uniform fluence profiles with spatial resolution and uncertainties of a few percent. Dedicated irradiation campaigns allow for determination of the proton hardness factor of κ = 3.75 ± 0.12, enabling one to irradiate up to NIEL fluences of 1 × 1016 neq /cm2 within a few hours. Comparison of multiple irradiation sites shows good agreement of the NIEL scaling with the irradiation site at the BIC providing the largest scaling factor at the lowest relative uncertainty.
Using the established irradiation infrastructure, radiation hardness studies of an ITkPix pixel detector assembly are performed. After proton irradiation up to the anticipated ATLAS ITk end of life levels for the sensor and readout chip, respectively, the assembly is functional and can be operated within specifications in a lab setting. Subsequent test beam measurements show a hit detection efficiency of up to 91 % with the indication of possibly achieving higher efficiencies by increasing the sensor bias voltage. In conclusion, an irradiation site has been implemented at the BIC, allowing for irradiations up to extreme fluence levels with low uncertainty, using protons with high NIEL scaling. Radiation damage studies of an ITkPix pixel detector assembly show its suitability for operation up to the radiation levels anticipated for the ATLAS ITk
Ukraine - NATO Identity Politics 1997-2018 : Representations of National Identity on the Question of Accession
Get PDFThis dissertation analyses the changes in national identity among the ruling political elites in Ukraine. Specifically, it argues that there is a constitutive relationship between changes in foreign policy and transformations in the discursive articulation of Ukraine's identity. The argument is developed on the basis of a longitudinal study on Ukraine-NATO identity politics from 1997 to 2018. Ukraine has been an outlier in the NATO enlargement process: it has had territorial disputes and a protracted armed conflict, it has neither reached a consensus on its Euro-Atlantic integration policy within the country nor has it ensured full support of NATO membership. Yet, despite the lack of a formal invitation to join NATO, Ukraine's ruling elites managed to adopt amendments to the Constitution, fixing the aspirations of NATO membership in 2019. This dissertation explores the intertwined nature of national debates on NATO accession, placing trends in national identity projects in their historical national and international contexts.
The research takes into account structural changes of Ukrainian politics and national identity articulation, applying a discourse-analytical approach to a wider political debate. Foreign policy is treated as identity politics.
The results of the dissertation provide a nuanced understanding of a variety of positions on Ukraine-NATO relations that were constructed within three basic discourses on NATO accession. Russia, NATO, and the U.S. are constitutive Others that shape identity representations of Ukraine into different projects of identity articulated by basic discourses. Representations which became incompatible with political realities and other national identity representations disappeared from those discourses. The national identity project constructed by the dominant pro-NATO discourse provided a justification for fixing NATO accession in the constitution
Colostrum Management on German Dairy Farms : Current State and Potential for Improvements
Get PDFCalf rearing is the fundament of any dairy farm. In consequence, colostrum management is an important part of calf rearing because calves are passively immunized through colostrum uptake. Therefore, colostrum management is of particular importance for healthy calves and long lasting performances of cows and should be optimized. However, high mortality and morbidity rates of 3.0–15.0% in German calf rearing indicate that colostrum management has enormous potential for improvement. The objective of this thesis was to identify potential strategies for enhancement and to underscore the significance of optimized colostrum management on German dairy farms. The thesis offers a comprehensive account of colostrum management and its implications for calf development.
Study 1 looked at indirect and direct methods of measuring colostrum quality. Direct methods are not easily applicable in practice, so farmers have to resort to indirect methods such as colostrometers and refractometers. Indirect methods allow conclusions about the concentration of Ig in colostrum, which can be used to assess the quality of the colostrum. In addition, the parameters influencing the Ig concentration were investigated in Study 1. Many parameters can be considered and positively influenced by the farmer. In particular, yield, parity and temporal aspects serve as key factors. Newer aspects such as dry period, seasonal influences and genetics are becoming increasingly important, but their impact on Ig concentrations has not been sufficiently investigated. Furthermore, there is a particular need for research in the area of data management.
To gain an overview of colostrum management practices on German dairy farms, a 33 question online survey focusing on frozen colostrum storage was developed (Study 2). The survey highlighted areas where a more targeted knowledge transfer can improve colostrum management. In addition, there appeared to be a lack of “Standard Operating Procedures” for employees on the practical implementation of colostrum management. Particular attention should be paid to the regular determination and documentation of Ig concentrations. The added value of stored colostrum should also be emphasized, especially for smaller farms.
Based on the two studies, the three areas of work organization, knowledge transfer, and data management were placed in the context of improved colostrum management. The objective was to identify the most important future tasks and implementation challenges to achieve adequate colostrum management of German dairy farms.Die Kälberaufzucht ist die Basis eines jeden Milchviehbetriebes. Insbesondere das Kolostrummanagement ist ein wichtiger Bestandteil der Erstversorgung, da die Kälber über das Kolostrum eine passive Immunisierung erfahren. Hohe Mortalitäts und Morbiditätsraten in der deutschen Kälberaufzucht von 3.0–15.0 % zeigen jedoch, dass das Kolostrummanagement ein enormes Optimierungspotenzial aufweist. Ziel dieser Dissertation war es, Verbesserungsstrategien aufzuzeigen und die Bedeutung eines optimierten Kolostrummanagements in deutschen Milchviehbetrieben hervorzuheben. Die Arbeit bietet eine umfassende Darstellung des Kolostrummanagements und seiner Auswirkungen auf die Kälberentwicklung.
Studie 1 beschäftigte sich mit indirekten und direkten Messmethoden zur Erfassung der Kolostrumqualität. Direkte Messmethoden sind in der Praxis nicht ohne weiteres anwendbar, daher müssen die Landwirte meist auf indirekte Methoden mittels Kolostrometer oder Refraktometer zurückgreifen. Indirekte Methoden lassen Rückschlüsse auf die Ig Konzentration im Kolostrum zu, wodurch die Qualität des Kolostrums beurteilt werden kann. Weiterhin wurden in Studie 1 die Einflussfaktoren auf die Ig Konzentration untersucht. Es gab zahlreiche Einflussfaktoren, die jedoch vom Landwirt berücksichtigt und positiv beeinflusst werden können. Insbesondere die Kolostrummenge, Laktation und zeitliche Aspekte spielen eine wesentliche Rolle. Neuere Aspekte wie Trockenstehzeit, saisonale Einflüsse und Genetik gewinnen an Bedeutung, ihr Einfluss auf die Ig Konzentration ist aber noch nicht ausreichend untersucht. Außerdem besteht vor allem im Bereich des Datenmanagements Entwicklungsbedarf.
Um einen Überblick über die Praxis des Kolostrummanagements in deutschen Milchviehbetrieben zu erhalten, wurde eine Online Umfrage mit 33 Fragen entwickelt (Studie 2), die sich auf gefrorene Kolostrumreserven konzentrierte. Die Umfrage zeigte Bereiche auf, in denen ein gezielterer Wissenstransfer das Kolostrummanagement verbessern kann. Darüber hinaus schien es an konkreten, umsetzbaren Anweisungen (sog. Standard Operating Procedures) für das Personal zur praktischen Umsetzung des Kolostrummanagements zu mangeln. Dabei sollte vor allem auf die regelmäßige Bestimmung und Dokumentation der Ig Konzentrationen Wert gelegt werden. Auch der Mehrwert von gelagertem Kolostrum im Vergleich zu einem höheren Arbeitsaufwand sollte insbesondere in kleineren Betrieben hervorgehoben werden.
Auf Basis der beiden Studien werden die drei Bereiche Arbeitsorganisation, Wissenstransfer und Datenmanagement in den Kontext eines verbesserten Kolostrummanagements gestellt. Um das Kolostrummanagement in deutschen Milchviehbetrieben zu verbessern, war es das Ziel, die wichtigsten zukünftigen Aufgaben und Herausforderungen bei der Umsetzung zu identifizieren
Amtliche Bekanntmachungen, 55. Jahrgang, Nr. 59
No full textPrüfungsordnung für den konsekutiven Masterstudiengang „Agricultural Science and Resource Management in the Tropics and Subtropics“ (ARTS) der Agar-, Ernährungs- und Ingenieurwissenschaftlichen Fakultät der Rheinischen Friedrich-Wilhelms-Universität Bonn vom 20. August 202
Die adjuvante Radiosynoviorthese bei Pigmentierter Villonodulärer Synovialitis : eine retrospektive Analyse der Rezidivrate und der postoperativen Funktionalität
Get PDFDie PVNS ist eine seltene proliferative Erkrankung vor allem des jungen Menschen mit schmerzhaften Gelenkbeschwerden. Der Goldstandard der Behandlung ist die operative Resektion. In der Literatur wurde in den letzten Jahren zunehmend die RSO als Rezidivprophylaxe aufgeführt. Ihr Nutzen bleibt in Ermangelung suffizienter Daten umstritten. Ziel der vorliegenden Arbeit war die retrospektive Auswertung eines Patientenkollektivs nach operativer Behandlung einer PVNS hinsichtlich der Rezidivrate und Gelenkfunktion in Abhängigkeit der Durchführung einer adjuvanten RSO. In dieser retrospektiven Datenerhebung konnten zwischen April 2010 und April 2020 38 Patienten eingeschlossen werden, bei denen in der Klinik und Poliklinik für Orthopädie und Unfallchirurgie des Universitätsklinikums Bonn eine PVNS diagnostiziert und behandelt wurde. Die Gelenkfunktion wurde anhand der KOOS, HOOS, LEFS und EQ5D5L-Fragebögen ermittelt. Die statistische Auswertung erfolgte mit SPSS 16 für Microsoft Windows. Gruppenunterschiede wurden mit dem Mann-Whitney-U-Test sowie Chi² Test ermittelt. Eine statistische Signifikanz wurde ab einem p-Wert von < 0,05 (Alpha-Signifikanzniveau 5 %) angenommen. Von den 38 untersuchten Patienten erhielten 25 (66 %) eine adjuvante RSO nach operativer Resektion der PVNS und 13 (34 %) Patienten wurden rein operativ behandelt. In der Kontrollgruppe ohne adjuvante RSO zeigten sich 3 Rezidive (23 %). In der RSO-Gruppe kam es zu 4 Rezidiven (16 %). Es gab keinen statisch signifikanten Unterschied zwischen den beiden Gruppen. Hinsichtlich der ausgewerteten Algofunktionsscores ergab sich für die getesteten Items aus dem KOOS, dem LEFS, dem KSS und dem EQ5D5L kein statisch signifikanter Unterschied zwischen beiden Gruppen. Somit zeigen die Ergebnisse keinen statistisch signifikanten Unterschied zwischen beiden Gruppen in Bezug auf die Rezidivrate oder die Gelenkfunktion. Die Hauptlimitation der Studie ist die geringe Anzahl an Patienten. Auf der Grundlage der vorliegenden Daten konnte kein Vorteil der RSO, bezogen auf die Rezidivrate und die Gelenkfunktion, nachgewiesen werden, so dass unter gleichzeitiger Berücksichtigung der einschlägigen Literatur deren adjuvante Durchführung nicht empfohlen werden kann
Identification of compensatory mechanisms and disease pathways in mitochondrial disease and synucleinopathy
Get PDFMitochondria play vital roles in a variety of processes such as cellular metabolism, intracellular signalling and cell death. Defects in mitochondria can lead to inherited metabolic disorders and neurodegenerative diseases. There is often a poor genotype-to-phenotype correlation in mitochondrial diseases, with distinct mutations that lead to a wide variety of clinical manifestations, age of onset and disease severity. This heterogeneity of symptoms, in combination with a relatively low frequency in the population, makes the development of novel treatments particularly challenging.
In invertebrates and some mouse models of mitochondrial diseases, inhibition of the mitochondrial oxidative phosphorylation (OXPHOS) can lead to a paradoxical lifespan extension through the engagement of compensatory mechanisms. As an explanation of this phenomena, the “mitochondrial threshold effect theory” states that mitochondrial dysfunction below a certain threshold promotes stress resilience and metabolic rewiring, leading to enhanced longevity. However, if damage exceeds a certain threshold, animals develop disease. In a human context, a better understanding of the “mitochondrial threshold effect” may explain some of the molecular signatures and variable disease traits observed in patients.
We sought to explore the compensatory mechanisms that organisms activate in response to the inhibition of OXPHOS using Caenorhabditis elegans as a genetically tractable model, in combination with mouse and human cells. Our goals were to investigate the underlying molecular mechanisms that contribute to mitochondrial dysfunction and neurodegenerative processes.
By performing a cross-species analysis, we identified VPS-39/VPS39 and SPL-1/SGPL1 to be part of the molecular mechanisms that compensate for mitochondrial dysfunction. In the context of neurodegenerative processes, we found that the actin nucleation promoting factor WSP-1/N-WASP is a disease modifier that contributes to mitochondrial dysfunction and proteotoxicity. Together, these results build on our growing understanding of the mechanisms that counteract mitochondrial dysfunction and pathogenic processes
Characterization of dopaminergic innervation and receptor expression in mouse models and patients with Focal Cortical Dysplasia
No full textFocal Cortical Dysplasia (FCD) type 2 is the most prevalent malformation of cortical development (MCD) associated with pharmacoresistant focal epilepsy, frequently located in the frontal cortex. Neuropathological features include abnormal cortical layering and enlarged dysmorphic neurons and balloon cells. Profoundly altered local neuronal activity has been observed in epilepsy-surgical biopsies from patients with FCD type 2. Notably, FCD type 2 emerges during brain development and integrates into complex connectivity architectures with surrounding neuronal networks. Local cortical microcircuits, especially in the frontal cortex, are extensively modulated by monoaminergic axonal projections from the brainstem. Prior studies of human FCD type 2 biopsies suggested altered density and distribution of monoaminergic axons; however, a systematic investigation remains lacking.
In this study, we provide a comprehensive analysis of dopaminergic (DA) innervation in human FCD type 2b biopsies and in the medial prefrontal cortex (mPFC) of a mouse model with mTOR hyperactivation (FCD type 2 model) during adolescence and adulthood. We also investigate DA receptor transcript expression using multiplex fluorescent RNA in situ hybridization in human specimens and the mPFC of this mouse model. Our findings in the mouse model reveal transient alterations in DA innervation density during adolescence and a trend toward decreased innervation in adulthood. Similarly, in human FCD type 2b biopsies, DA innervation density is reduced in the affected cortical areas compared to control regions from the same patients, with an altered lamination pattern of DA axons in the FCD type 2b regions. Additionally, DA receptor 1 (DRD1/Drd1) and receptor 2 (DRD2/Drd2) mRNA transcripts are upregulated in dysmorphic neurons in human samples and mTOR-mutated neurons in mice, compared to normally-developed neurons from control tissue or surrounding ones.
These findings suggest complex molecular and structural cortical changes impacting DA neurotransmission within FCD type 2 and putatively affecting local cortical activity, manifestation of seizures and psychiatric comorbidities. This impaired DA signaling may have significant implications for understanding the pathology of FCD type 2 and developing targeted therapeutic strategies
TNIP1 affects proliferation, apoptosis and migration of Human Embryonic Kidney 293 cells
Get PDFTNIP1 is a protein associated with autophagy and inflammation, which is ubiquitously expressed in the brain. It mediates extracellular signals such as growth factor signaling, influences nuclear expression patterns driven by NF-kappaB transcriptional regulation and exhibits both pro- and anti-apoptotic properties. The involvement in these cellular pathways deems it an attractive candidate gene for neurodegenerative disease pathogenesis. In fact, gene variations of TNIP1 have recently been linked to both amyotrophic lateral sclerosis and Alzheimer’s disease. Moreover, TNIP1 has been shown to interact with Engrailed-2, a transcription factor associated with autism spectrum disorder (ASD). While the linkage between ASD and TNIP1 is currently low, the fact that TNIP1 has long been considered a pleiotropic risk locus for autoimmune and chronic inflammatory disorders, is intriguing, considering these are common comorbidities of ASD. Despite the plethora of links to cell death and inflammatory processes in the body, exact cellular and molecular pathways are not yet elucidated. In addition, proper animal models are not available thus far. Therefore, it was the aim of this thesis, to establish genetic tools to overexpress and repress TNIP1. Using these genetic tools, I was able to demonstrate that TNIP1 expression can be altered in the mammalian cell line HEK 293. I was able to identify an antibody suitable to track changes in TNIP1 expression and I demonstrated that the alteration of TNIP1 expression in HEK 293 cells enhanced apoptosis and diminished both proliferation and cellular migration. Having these tools at hand now paves the way not only for the manipulation of neuronal cell cultures, but also for the investigation of TNIP1 expression patterns in brain tissue. It will also allow for the characterization of animal models, to hopefully provide further insights into TNIP1 mediated neurodegenerative processes
Spatio-Temporal Perception for Mobile Robots in Dynamic Environments
No full textRobotic systems have the potential to revolutionize operations in environments that are too dangerous, intricate, or demanding for humans. These environments pose notable challenges due to their dynamic and often unpredictable nature, requiring robots to identify and adapt to short- and long-term changes. By leveraging advanced perception capabilities, robots can address critical tasks such as preventing accidents by detecting and reacting to vulnerable road users. They can also autonomously transport humans and goods while adapting to evolving demands, carrying out time-consuming tasks like crop monitoring, or accomplishing dangerous missions like disaster response. Robots can execute tasks more efficiently and safely by overcoming human limitations such as fatigue, inattention, or restricted sensory perception.
In these scenarios, mobile robots typically operate autonomously, continuously perceiving their environment to estimate both their internal state and the state of their surroundings. They usually rely on sensors like global navigation satellite system receivers, cameras, radar sensors, inertial measurement units, or LiDAR scanners. Key tasks include building maps of the environment, localizing in such maps, or segmenting different classes like cars, buildings, or traffic signs. Urban environments are often complex and dynamic, containing moving objects like humans or undergoing structural changes. To solve such tasks, a mobile robot must possess both spatial awareness and spatio-temporal perception - an understanding of how the environment evolves and what is changing in it explicitly. A major challenge these approaches encounter is the unknown nature of the environment beforehand, which requires the system to be highly robust and able to generalize across different sensor configurations and settings.
This thesis focuses on two main questions when deploying mobile robots in unknown and dynamic environments: “What is moving?” and “Where is an object moving to?”. We must process and interpret spatial and temporal data to address these. First, knowing which parts of the environment belong to moving objects is an essential spatio-temporal perception task for online path planning. For example, moving objects occupy space only temporarily, meaning we can consider the space again traversable for planning after the object has moved. Moving objects can also advance into areas previously regarded as free, causing potential collisions with our planned trajectory. Second, we are interested in estimating the future state of the surroundings. This prediction enables us to, for example, properly plan a future path that reflects the future behavior of other traffic participants.Roboter haben das Potenzial, Aufgaben in Umgebungen zu übernehmen, die für Menschen zu gefährlich, komplex oder anspruchsvoll sind. Solche Umgebungen stellen aufgrund ihrer dynamischen und oft unvorhersehbaren Natur besondere Herausforderungen dar. Mobile Systeme müssen daher in der Lage sein, kurz- und langfristige Veränderungen in ihrer Umwelt zu erkennen und entsprechend darauf zu reagieren. Mithilfe intelligenter Wahrnehmungssysteme können Roboter Unfälle verhindern, indem sie beispielsweise andere Verkehrsteilnehmer erkennen und rechtzeitig Ausweichmanöver einleiten. Zudem können sie autonom Personen und Güter transportieren, zeitaufwändige Aufgaben wie die Überwachung von Pflanzenwachstum übernehmen oder gefährliche Missionen im Katastrophenschutz durchführen. Generell erledigen Roboter Aufgaben effizienter und sicherer als Menschen, die durch Müdigkeit, Unaufmerksamkeit oder eingeschränkte Sinneswahrnehmungen beeinträchtigt sein können.
In den genannten Szenarien arbeiten mobile Roboter in der Regel autonom und nehmen kontinuierlich ihre Umgebung wahr, um sowohl ihren internen Zustand als auch die Umwelt zu analysieren. Dazu nutzen sie Sensoren wie globale Navigationssatellitensysteme, Kameras, Radarsensoren, inertiale Messeinheiten oder LiDAR-Scanner. Zu den wichtigsten Aufgaben gehören die Erstellung von Karten, die Lokalisierung in diesen Karten und die Segmentierung von Sensordaten in Klassen wie Autos, Gebäude oder Verkehrsschilder. Um diese Aufgaben effektiv zu lösen, muss ein mobiler Roboter seine komplexe und dynamische Umgebung sowohl räumlich als auch zeitlich wahrnehmen. Dazu analysiert er bewegte Objekte wie Menschen und erkennt gleichzeitig strukturelle Veränderungen der Umwelt. Eine besondere Herausforderung ist, dass weder die Beschaffenheit der Umgebung noch die Eigenschaften der Objekte im Vorfeld bekannt sind. Dies erfordert eine hohe Robustheit der Systeme gegenüber Unsicherheiten sowie die Fähigkeit, über verschiedene Sensorkonfigurationen hinweg zu generalisieren.
Diese Arbeit konzentriert sich auf zwei zentrale Fragen beim Einsatz mobiler Roboter in unbekannten und dynamischen Umgebungen: “Was bewegt sich?” und “Wohin bewegt sich ein Objekt?”. Um diese zu beantworten, verarbeiten und interpretieren wir räumliche und zeitliche Daten. Erstens müssen wir bewegte Objekte identifizieren, da diese temporäre Hindernisse für die Online-Pfadplanung darstellen. Zweitens ist es notwendig, den zukünftigen Zustand der Umgebung zu schätzen, um beispielsweise einen Pfad zu planen, der das zukünftige Verhalten anderer Verkehrsteilnehmer berücksichtigt