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Amtliche Bekanntmachungen, 55. Jahrgang, Nr. 42
No full textKorrektur einer Ausgabe der Amtlichen Bekanntmachungen: Wahlbekanntmachung für die Nachwahl eines Mitglieds in der Gruppe der Hochschullehrerinnen und Hochschullehrer zum Senat im Wahlkreis Katholisch-Theologische Fakultät der Rheinischen Friedrich-Wilhelms-Universität Bonn vom 17. Juli 202
Vergleichende Untersuchung zur Pränataldiagnostik und Therapieregime von Teratomen und kindlichen Tumoren im Kopf-/Halsbereich
Get PDFEpignathi im Kopf-/Halsbereich sind seltene angeborene Fehlbildungen oder Tumore. Das am Universitätsklinikum Bonn zwischen 1989 und 2019 nachuntersuchte Patientenkollektiv mit 43 Fällen behandelter zervikofazialen Epignathi zeigte eine sehr gute Prognose hinsichtlich der Resektabilität und dem Langzeitüberleben, wobei in fünf Fällen eine EXIT-Prozedur indiziert war. In 53 % (n=18) der Fälle handelte es sich bei den Neoplasien um Teratome, gefolgt von Lymphangiomen (n=5) und selteneren Tumorentitäten wie z.B. Rhabdomyosarkomen. Die stationäre Liegedauer der 12 von 18 in domo geborenen und überlebenden Kindern betrug durchschnittlich 37 Tage (min. 1 bis max. 122; SD=35,5), wobei es in 67 % einer intensivmedizinischen Betreuung mit einer durchschnittlichen Beatmungsdauer von 28 Tagen bedurfte. Die Langzeituntersuchung zeigt eine Rezidivfreiheit für die sechs nachuntersuchten Teratomfälle. Kinder mit einem Epignathus erfordern eine umfassende Versorgung und suffiziente Pränataldiagnostik, selbst dann, wenn keine oder nur wenigen Komorbiditäten vorliegen. Neben einer Sonographie ist eine weitere Bildgebung indiziert. Ein pränatal durchgeführtes MRT ist nicht zwingend notwendig, kann allerdings in vielen Fällen das weitere Procedere und die Operationsplanung erleichtern und zeigte in der Nachuntersuchung, das mit progredientem Tumorwachstum cervikofaziale Strukturen zunehmend verdrängt werden (p=0,0007). Das durchschnittliche Tumorwachstum für Teratome betrug 67±62 cm3/Woche. Limitierender Faktor pränataler MRTs ist die eingeschränkte Beurteilbarkeit relevanter cervikofazialer Strukturen. Die Einschätzung hinsichtlich komprimierter oder nicht abgrenzbarer Strukturen im Vergleich zum postnatalem MRT ist erschwert und wird leicht überschätzt (14 % pränatal vs. 2 % postnatal). Bei nicht durchgeführtem pränatalem MRT sollte zumindest postpartal eine MRT-Untersuchung als Standard vor einer chirurgischen Intervention erfolgen. Aktuell gibt es in der Epignathusdiagnostik keine einheitliche Pränataldiagnostik. Verschiedene Laborparameter, können als erweiterte Diagnostik beim Teratom- bzw. Rhabdomyomverdacht während der Schwangerschaft hilfreich sein. Bei einer auffälligen Sonographie mit Vorliegen eines Polyhydramnions können zur weiteren Abklärung die genannten Marker indiziert sein. Bezüglich der gesundheitsbezogenen Lebensqualität, welche mittels dem PedsQL ermittelt wurde, zeigt sich die Tendenz, dass unser Patientenkollektiv im emotionalen Bereich eine unterdurchschnittliche Lebensqualität zeigt. Der körperliche, soziale und kognitive Bereich lagen jeweils über dem Durchschnitt. Aufgrund der geringen Anzahl der Auswertung sind eine Nachbearbeitung wünschenswert und weitere Studien nötig. Zusammenfassend ist die Qualität der perinatalen Versorgung von entscheidender Bedeutung um sicherzustellen, dass jeder Patient die bestmögliche Betreuung erhält
Temporary migration: Characteristics, livelihood effects, and destination choices in northern rural Bangladesh
Get PDFTemporary migration is common in poor agrarian economies but remains largely under-researched. While this migration is weaker in reducing poverty than longer-term migration, the reasons many poor rural households continue to prefer temporary migration are inadequately explored in the literature. Similarly, while migration theories often emphasize income-driven migration from rural origins to urban destinations, the preference for rural destinations among many temporary migrants also remains unclear. Employing a mixed-method approach, this study addresses these two key questions in northern rural Bangladesh, contributing to the emerging literature on temporary migration in poor agrarian economies. A qualitative methodology is used to conceptualize temporary migration and destination decision-making, while these insights are further explored through quantitative data from over 800 household surveys and relevant econometric models.
The findings reveal that farm labor constraints and family obligations limit longer-term migration, making temporary migration a viable alternative for risk diversification in the less-diversified local economy. For poor rural households, temporary migration is crucial for improving food consumption and dietary quality during agricultural lean periods, despite its relatively limited effects on overall household income compared to longer-term migration. Additionally, constrained, poor households often favor rural destinations for temporary migration, which offer a better income-to-cost ratio and allow short-duration mobility without exacerbating their existing constraints at home. By contrast, urban destinations, while associated with higher remittance potential, pose greater costs and risks, making them less viable for these households.
The study highlights the importance of supporting temporary migration as a critical risk mitigation strategy in poor agrarian contexts. Policy measures such as improving access to wage information, reducing search costs, and enhancing inter-district transportation networks could facilitate temporary migration, particularly to rural destinations, thereby improving the welfare of a significant portion of poor agrarian societies. These measures could not only benefit migrating households but also help address farm labor shortages in labor-intensive agricultural regions. Additionally, the study calls for further research into the effects of temporary migration on agricultural production in destination rural areas and the implications of farm mechanization for the livelihoods of rural-bound temporary migrant households
Workflow Integration of Artificial Intelligence in Clinical Practice
Get PDFArtificial intelligence (AI) is increasingly being integrated into healthcare to support clinicians, reduce workloads, and improve workflow efficiency. AI is particularly beneficial in image-based and data-driven medical fields due to its pattern recognition capabilities. While extensive research has been done to explore the potential of AI under experimental conditions, the knowledge about the intricacies of its real-world implementation in clinical settings remains scarce. Consequently, a human factors approach that considers healthcare's complexity as a sociotechnical system is essential.
In this dissertation an examination of the AI integration into clinical workflows is presented, offering a comprehensive view of human-AI interaction in healthcare's complex environment. The theoretical background of this work is the System Engineering Initiative for Patient Safety Model, with the related Conceptual Model of Workflow Integration and the Technology Acceptance Model. Three research projects – one systematic review and two use cases – are presented in this dissertation.
The systematic review involved an assessment of AI's impact on efficiency, clinician outcomes, and workflows in medical imaging, revealing a positive effect on time for tasks and leading to the identification of different AI-augmented workflows. A novel framework was also introduced to categorize the level of AI implementation in the studies. The first considered use case involved an AI implementation in a radiology department, where the AI tool under study was not yet fully integrated into the routine workflow. While the users who participated in the study initially had a positive attitude, the poor fit and longer reading times for complex cases led to workarounds and frustration. The second considered use case, a fully implemented AI tool in human genetics, highlighted that usability and organizational factors were key to successful adoption, as most users incorporated the tool into their daily routines.
The work for this dissertation combined various study designs across different medical specialties. By identifying multiple variations of AI-facilitated clinical workflows, it was emphasized that the context of AI implementation is often unique and AI implementation requires local adaptation. Moreover, recommendations drawing upon identified facilitators and barriers are proposed which should be considered for safe and effective future implementation processes of AI in clinical care
Chemosensitivierung von Ovarialkarzinomzellen mittels Laserstrahlen
Get PDFDas Ovarialkarzinom ist eine häufige gynäkologische Tumorerkrankung. Das Fehlen spezifischer Frühsymptome und einer effektiven Screeningmethode führt dazu, dass diese bei einem Großteil der Betroffenen erst spät erkannt wird. Eine Therapie in fortgeschrittenen Stadien ist mit einer Vielzahl von Nebenwirkungen und einer hohen Einschränkung der Lebensqualität verbunden. Die hypertherme intraperitoneale Chemotherapie ist ein umstrittener Therapieansatz, da sie mit einer hohen Rate an Nebenwirkungen einher geht. Durch Kombination mit physikalischen Verfahren wie Laserstrahlung könnten diese reduziert werden. Die Exposition mit Laserstrahlung wirkt auf verschiedene zelluläre Regulationsmechanismen, unter Anderem auf die Membranpermeabilität. Darüber können Laserstrahlen eine gesteigerte Aufnahme von Zytostatika in die Tumorzellen bewirken. Der Erfolg der Laserbehandlung ist abhängig von der Laserleistung, -energie und Behandlungszeit. Der klinische Einsatz von Laserstrahlen ist vielfältig und könnte mit diesen Erkenntnissen in Zukunft weiter ausgebaut werden
Adoption and Impacts of Animal Health Management Practices in Kenya’s Dairy Sector
Get PDFCurrent trends in population growth and increased demand for animal-sourced foods (ASF) present opportunities for many livestock farmers in the Global South. However, poor health conditions in livestock production continue to cause sizeable losses. Accessing and utilizing important animal health services is still challenging for many resource-constrained farmers. Thus, interventions to increase access to these services would be an important policy objective towards sustainable livestock intensification. However, to better design policies, there is a need to also understand the potential implications - both social and environmental - of these animal health management practices. This dissertation seeks to contribute to the literature through three essays, focusing on various relevant aspects in dairy systems in Kenya. The research uses primary data collected through surveys and experiments with dairy farmers and econometric methods for data analysis.
In the first essay, we explore how to better design animal health service provision through dairy cooperatives using a choice experiment. Results provide evidence of farmers’ preferences for institutional innovations that overcome technical and liquidity constraints in accessing the East Coast Fever (ECF) vaccine. This is also likely to hold for other animal health services. In the second essay, we provide empirical evidence that the adoption of these practices is associated with more labor demand for men and women in livestock production activities. The findings also show negative associations with different aspects of women empowerment including access to and control over income and productive resources. Lastly, in the third essay, using regressions and the environmental impact quotient (EIQ), we show improper acaracide use practices – an important preventive practice against ticks – are associated with increased potential negative effects on the environment and human health.
The findings of this study underscore the important role that collective institutions such as dairy cooperatives can play in providing last-mile access to technologies including animal health services. However, future policy interventions on sustainable intensification of livestock production should be gender-sensitive. Further, we advocate for the design of policies that promote the responsible use of acaricides and call for the promotion of environmentally friendly approaches in vector control in livestock systems.
Behandlung von Tumorschmerzen unter den Bedingungen der Covid-19 Pandemie
Get PDFMit der am 11. März 2020 offiziell als Pandemie klassifizierten Verbreitung des zum damaligen Zeitpunkt neuartigen Coronavirus Sars-Cov2 und der damit verbundenen Erkrankung Covid-19, welche sich seit Dezember 2019 von Wuhan in China aus verbreitet hatte, ergaben sich weitreichende Konsequenzen in allen Lebensbereichen, insbesondere in der medizinischen Versorgung.
Im Spannungsfeld der Versorgung von Patient:innen und Patientengruppen unter den Bedingungen einer Pandemie, konnte in diversen Bereichen des medizinischen Sektors eine Versorgungseinschränkung herausgearbeitet werden. Hüppe D et. Al (2020) stellten beispielhaft die Versorgungsprobleme von Patient:innen mit chronischer Hepatitis C während der COVID-19-Pandemie und den Lockdown-Verordnungen dar, während Bialas E et al. (2020) im Rahmen der Auswirkungen des Lockdowns im April 2020 einen Rückgang im Bereich der planbaren Operationen von mehr als 40 % ermittelten.
Von den in Deutschland jährlich rund 500 000 Patient:innen mit der Diagnose einer Krebserkrankung (RKI, 2019) entwickeln im Verlauf bis zu 90 % tumorbedingte Schmerzen (Deutsche Schmerzgesellschaft, 2021). Diese werden in unterschiedlichen Organisationseinheiten, wie zum Beispiel Schmerzambulanzen, AAPV, SAPV, Palliativstationen oder Schmerzstationen schmerzmedizinisch versorgt. Mit dem neuaufgetretenen Coronavirus und der Entwicklung der pandemischen Lage im Frühjahr 2020 in Deutschland bestand in diesem Sektor die Gefahr von Versorgungseinschränkungen.
Bisher existieren keine Untersuchungen zur Versorgung von Tumorschmerzpatient:innen während beziehungsweise unter den Bedingungen der Covid-19 Pandemie.
Das Ziel der vorliegenden Untersuchung war in diesem Zusammenhang eine systematische Analyse des Ausmaßes der Versorgungseinschränkungen, denen sich die Patient:innen seit diesem Zeitpunkt ausgesetzt gesehen haben, sowie die Herausarbeitung und Bewertung angewandter Strategien zur Bewältigung der entstandenen Problematik mit Blick auf Verbesserungsmöglichkeiten bezüglich künftiger Pandemieereignisse
Human Aspects in Secure Messaging
Get PDFThe widespread adoption of digital communication demands robust security and privacy protections, particularly through secure messaging systems that can protect personal and sensitive information. Despite advancements in end-to-end security, encryption, and anonymity, significant gaps remain in usability and user trust, limiting widespread adoption. This cumulative dissertation examines the human aspects of secure messaging systems through four peer-reviewed studies, addressing fundamental challenges in usability, trust establishment, and practical implementations.
Diverse methodological approaches drive the research, including systematic protocol analysis with a focus on human aspects, large-scale empirical studies, and qualitative investigations, alongside the proposal and evaluation of improved technical implementations. First, a comprehensive systematization of knowledge establishes a unified framework for evaluating secure messaging protocols and “in-the-wild” tools, investigating critical gaps in current approaches. Second, an empirical study with 1047 participants examines fingerprint representation approaches for trust establishment. Third, qualitative research explores potential misconceptions in user mental models and trust for end-to-end security in general. Finally, a novel hardware-based approach utilizing NFC-enabled wearables demonstrates practical solutions for simplifying cryptographic key management while maintaining security.
Key findings indicate that (1) trust establishment remains the cornerstone of secure messaging, as it requires user interaction and underpins the entire security guarantees; failure in this area compromises the system entirely. (2) traditional hex-based fingerprint representations significantly underperform in both attack detection and perceived usability compared to the proposed sentence-based representation, but also numeric representation, as commonly used outside cryptographic contexts, also proving more effective; (3) users mistrust messaging platforms and security features in general and substantially overestimate attackers while underestimating cryptographic capabilities; and (4) less invasive security mechanisms as with using wearables show promise for broader adoption. The findings align with current developments in secure messaging applications, where similar verification approaches are used.
This work advances the field of usable security by bridging theoretical understanding with practical implementation, contributing to the development of more effective and accessible secure communication systems. The findings provide guidance for designing next-generation secure messaging solutions that balance robust security with user needs and capabilities
Large Scale Single Cell RNA sequencing Analysis of Lung Tissue and Bronchoalveolar Lavage Fluid from Patients with Chronic Obstructive Pulmonary Disease, COVID-19 and Idiopathic Pulmonary Fibrosis
Get PDFIdiopathic Pulmonary Fibrosis (IPF) is a progressive interstitial lung disease of unknown etiology, primarily characterized by the development of fibrosis. IPF affects 3–9 out of every 100,000 people globally, with its prevalence on the rise. Early perspectives posited that IPF was a chronic inflammatory disease. However, due to the lack of evidence supporting sustained inflammation in IPF and the limited efficacy of corticosteroid treatments, this theory has been increasingly discredited.The few pharmacotherapies available have demonstrated limited effectiveness, and lung transplantation remains the only definitive treatment option for IPF.
Recent evidence increasingly indicates that IPF is associated with the loss or apoptosis of alveolar type 2 cells (AT2), which subsequently leads to dysregulated repair mechanisms and the pathogenic activation of fibroblasts. This observation evokes parallels with another disease characterized by AT2 cell damage: the recent global pandemic of COVID-19, which severe cases are also associated with the development of pulmonary fibrosis during the acute respiratory distress syndrome phase. Consequently, it is imperative to elucidate the central molecular mechanisms involving AT2 cells in these diseases.
Alveolar macrophages represent a specialized population of immune cells localized within the alveolar spaces, serving as sentinel guardians that play a critical role in maintaining pulmonary homeostasis and providing defense against pathogens. Therefore, elucidating the key regulatory hub that influence the functional outcomes of Alveolar macrophages is essential for optimizing their therapeutic potential in lung diseases.
In this study, we integrated 22 single-cell sequencing datasets pertaining to COPD, IPF, and COVID-19, and conducted a comprehensive analysis focusing on five major aspects: cell proportions, differentially expressed genes, cytokine profiles, the correlations with clinical indicators, and cellular interactions.Our findings revealed an increase in monocyte populations within the lung tissue of COPD patients, contrasting with a decrease observed in both COVID19 and IPF patients. Additionally, proliferative macrophages were found to be elevated in the lung tissue of IPF patients, while their presence was diminished in cases of COVID-19 and COPD. In respect of chemokine expression, Monocytes were found to express high level of CXCL8 in patients with COVID-19. In relation to clinical indicators, our study identified that gender differences across all three diseases led to alterations in alveolar epithelial cells. Furthermore, we also observed a positive correlation between macrophage subtypes and age in patients with COVID-19. With respect to the cellular communication, our findings indicate that in IPF, Apoptosis AT2 engage in cellular communication with macrophages subtypes (via the MK signaling pathway. Thus, our study reveals disease-specific profiles in alveolar epithelial cells and macrophages among COPD, IPF and COVID-19, highlighting potential therapeutic targets across these diseases
Algorithm Engineering and Integer Programming for the Maximum Cut Problem
Get PDFThe maximum cut problem, MaxCut for short, is one of the fundamental problems in combinatorial optimization. It is part of a large family of graph partitioning problems that ask for a division of all vertices of the graph into disjoint sets. In its optimization form MaxCut is about finding a bipartition that maximizes the value of a cut. A cut in the context of a vertex partition is defined as the set of edges connecting vertices of different partitions. The value of a cut is the sum of all weights associated with the edges of the cut.
Although MaxCut allows for a compact description, it has highly relevant modeling power. Many real-world applications for MaxCut have been described in the literature over the years; these range from chip design to scheduling sports leagues and, more recently, the benchmarking of certain quantum algorithms and computers. Depending on the application, good solutions do not suffice and practitioners and researchers are interested in optimal solutions. Unfortunately, MaxCut is NP-hard in general, and it is still unknown whether we can solve NP-hard problems fast, that is, in time polynomial in the input size. However, practical algorithms for solving MaxCut to optimality have been designed in the past, and this thesis aims to improve them and develop new ones. We focus especially on techniques for sparse graphs, as real-world instances often turn out to be sparse.
An important way to speed up algorithms for hard problems is to reduce the search space before even exploring it. The process of performing these reductions without sacrificing optimal solutions is called presolving. We develop new presolving algorithms for MaxCut in three categories. One of these is based on vertex separators that have not been explicitly considered for MaxCut so far.
For exploring and further pruning of the search space for MaxCut we resort to integer programming and the branch-and-cut algorithm, which has yielded good results for exact MaxCut algorithms in the past. We extend previous work and suggest a refined integer program. This model has implications for other modules part of the branch-and-cut algorithm that we present in detail. Examples are the generation of cutting planes and problem-specific branching rules. From these we derive new and concrete algorithms that can be employed in MaxCut solvers based on branch-and-cut.
To evaluate the practical relevance of our new techniques, we perform elaborate experimental studies and compare them against the state of the art. For this we carefully engineered a new solver that contains state-of-the-art techniques and our new ones. The solver is competitive to the fastest MaxCut solver in general and clearly outperforms the state of the art for certain inputs. In detailed ablation studies, we track these improvements down to our new techniques. Especially, our presolving and cutting plane generation offers significant speed-up potential of up to one order of magnitude over the state of the art