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The phenotypic and genetic basis of a reef fish radiation
Full text linkThe origins of the extraordinary diversity of life on Earth have long intrigued scientists. Evolutionary radiations, where species emerge from increased diversification rates, play an instrumental role in generating biodiversity. These events are often characterized and shaped by remarkable level of phenotypic diversity. At their early stages, phenotypic variation provides a substrate for selection and a means for further diversification. While the genomic underpinnings of speciation have been extensively investigated, phenotypic studies have been limited by analytical power, despite advances in data acquisition. The advent of computer vision now enables systematic, multivariate analyses of phenotypes, transforming our ability to examine their eco-evolutionary relevance. This thesis aims to investigate the evolution of color pattern phenotypes in the early stages of a reef fish radiation. I focus on the genus Hypoplectrus (hamlets), a group of 18+ species that exhibit striking color pattern differences and represent one of the most recent marine radiations. Color patterns in hamlets are implicated in visually based assortative mating, acting as prezygotic barriers, and may also play ecological roles through mimicry, thereby subjecting this trait to selection pressures. By integrating phenotypic and genomic approaches, I aim to characterize color pattern variation and explore its contribution to reproductive isolation at the onset of speciation. The genic view of speciation posits that at early stages a few loci can disproportionately contribute to reproductive isolation. By characterizing color pattern variation and its genomic basis in hamlets, I explore how this perspective aligns with patterns of speciation in this radiation. I first develop a quantitative pipeline for the analysis of standardized in situ photographs, providing the first multivariate, pixel-scale phenotypic dataset for reef fishes. Coupled with genomic association studies, this approach reveals three genomic regions of large effect that underlie color pattern variation. This modular genetic and phenotypic architecture suggests that hamlet diversity arises from different allele combinations at these loci. Expanding on this, I leverage a dataset of 571 photographs and genomic data from 327 individuals to examine interspecific and intraspecific variation. While phenotypic and genomic clusters of sympatric species are locally retrieved, these clusters become largely continuous at the scale of the whole radiation. This pattern, driven by intraspecific variation, suggests contributions from ancestral variation and hybridization, and underscores the role of local processes in sympatric speciation. Finally, I assess the genic view by integrating both whole-genome data and color pattern-associated genomic regions in a phylogenetic analysis. I find that reproductive isolation in hamlets does not translate into a phylogenetic signal, whether using whole-genome datasets or specific regions. As predicted under the genic view, these findings suggest that reproductive isolation can occur first without a detectable genomic signature. Taken together, my results support the view that speciation is a continuous and multidimensional process, where divergence accumulates along genetic and phenotypic axes, ultimately mediating reproductive isolation and diversification. These insights advance our comprehension of the complex interplay between genetics, phenotypes, and speciation, particularly in the early stages of evolutionary radiations
Untersuchungen der Immuncheckpoints VISTA und PD-L1 in der Plazenta von Präeklampsie-Patientinnen
Full text linkPräeklampsie gehört zur Gruppe der hypertensiven Erkrankungen in der Schwangerschaft. Die klassische Form zeigt sich durch Hypertonie und Proteinurie; frühestens ab der 20. SSW. Ca. 2 % aller Schwangerschaften in Europa sind betroffen.
Die Plazenta spielt eine Schlüsselrolle in der Entstehung. Ätiologisch wird die gestörte mütterlich-fetale Immuntoleranz diskutiert.
Diese Pilotstudie analysiert den Einfluss der immunsuppressiven Immuncheckpoints (ICs) PD-L1 und VISTA auf die Entstehung der Präeklampsie. Eine verminderte Expression von PD-L1 und VISTA wird bei Präeklampsie-Patientinnen erwartet.
Fixiertes Plazentagewebe (10 Präeklampsie-pos., 10 Präeklampsie-neg.) wurde mittels
immunhistochemischer Färbung sowie einer qRT-PCR mit Genstudie untersucht.
Eine signifikant reduzierte VISTA Expression bei Präeklampsie zeigte sich. Die Expression von PD-L1 war nicht signifikant erniedrigt.
Das spricht für eine zentrale Rolle von VISTA in der Immuntoleranz der Schwangerschaft.
Das langfristige Ziel stellt die Entwicklung von Prognosemarkern und die mögliche Behandlung der Präeklampsie hinsichtlich der immunologischen Ätiologie dar
Integrated Assessment of Demand-Side Flexibility: Quantification, Aggregation, Variability Analysis, and Evaluation of Operational Impacts
Full text linkThe PhD thesis investigates flexibility as an additional function of the energy systems, meaning that flexibility provision must not undermine their primary purposes and therefore must not negatively impact end-user energy needs. An integrated methodological framework is developed for the com-prehensive technical assessment of flexibility of the energy systems and storage installed in buildings and urban districts. This framework includes the quantification and aggregation of flexibility poten-tial, explicit consideration of the primary applications of the energy systems, incorporation of varia-bility and uncertainty, and evaluation of the impacts of flexibility provision on the subsequent opera-tion of energy systems and the power grid. The resulting flexibility is represented in a universal, two-dimensional, and technologically agnostic form, enabling consistent comparison and aggregation. This thesis establishes a foundation for the effective integration of demand-side flexibility into mod-ern energy infrastructure, supporting the sustainable and resilient power system with a high share of renewable energy sources
Retrospective analysis to verify the stability in dose distribution in patients with head and neck cancer undergoing radiotherapy for quality control
Full text linkOur study retrospectively analyzed the stability of dose distribution in patients undergoing radiotherapy for head and neck cancer. Due to the increasing incidence of head and neck cancers in Western Europe, radiotherapy serves as a key treatment alternative to surgery, especially for elderly and inoperable patients. Anatomical changes such as tissue swelling or weight loss can impact dose distribution, affecting treatment quality and patient outcomes. The study aimed to assess dose stability during the first 25 fractions and identify influencing factors.
Fourteen patients were analyzed using weekly CBCT scans during the first five treatment weeks, compared to the initial planning CT. Despite common acute side effects like mucositis (93%) and radiation dermatitis (64%), the dose remained stable in the tumor region and most organs at risk. Clinically relevant dose deviations were only observed in two cases involving the parotid glands. Further randomized studies are needed to optimize radiotherapy and patient outcomes
Environmental exposure assessment in the German National Cohort (NAKO)
No full textWe aimed to assess the exposure to multiple environmental indicators and compare the spatial variation across participants of the German National Cohort (NAKO) to lay the foundation for health analyses.
We collected highly resolved German-wide data to capture the following environmental drivers: urbanisation by population density; outdoor air pollution by particulate matter (PM2.5), nitrogen dioxide (NO2), ozone; road traffic noise; meteorology by air temperature, relative humidity; and the built environment by greenspace and land cover. All assessed exposures were assigned to the NAKO participants based on their baseline residential addresses.
The NAKO study regions ranged from highly urbanised areas (Berlin, Hamburg) to rural regions (Neubrandenburg). This large variation is reflected in the individual environmental exposures at the place of residence. In 2019, annual PM2.5 and NO2 levels ranged from 6.0 to 14.6 and 3.7–33.6 μg/m3, respectively. Annual mean air temperature ranged between 7.8 and 12.7 °C. Noise data was available for a subset of urban residents (22 %), of which 42 % fell into the lowest and 1.8 % into the highest category of Lden 55–59 and Lden >75 dB(A), respectively. Greenspace also showed considerable differences (Normalised Difference Vegetation Index between 0.08 and 0.84). Spearman correlation was moderate to high within the different exposure groups, but mostly low to moderate between the groups.
For the first time, a comprehensive population-based dataset with high quality environmental indicators is available for the whole of Germany. Expanding the database by adding innovative indicators such as light pollution, walkability, biodiversity as well as contextual socioeconomic factors will further increase its usefulness for science and public health
Combinatorial studies of Fano varieties via toric embeddings
Full text linkThis thesis contributes to the development of combinatorial methods for the study of geometrical invariants of Fano varieties. In the first part, we provide a combinatorial criterion for a non-degenerate toric complete intersection to be normal and irreducible. This is done by studying the structure of complete and simplicial fans corresponding to toric varieties of Picard number two. Secondly, we prove that the Gorenstein index of Fano general arrangement varieties can be read off the anticanonical complex (a polyhedral complex that generalizes the toric Fano polytope for broader classes of varieties) in full analogy to the Fano polytope. As an application, we classify certain threefolds with Gorenstein index at most three.
Lastly, we contribute to the classification of Fano threefolds with torus action of complexity one. For this purpose, we take advantage of the properties of the anticanonical complex. We extend previous classification results by allowing combinatorially non-minimal varieties
Gaze-based Multimodal Interaction: Methods for Active and Passive Gaze-based Interaction
Full text linkModern eye tracking technology allows developers to incorporate real-time gaze information as input to multimodal human-computer interfaces. It can be used as an active or passive input modality in multimodal interfaces: a user can influence a system via explicit eye movements, and a system can implicitly derive information about the user and the environment by analyzing eye tracking data. However, many issues remain underexplored, so the technology cannot be widely deployed in interactive intelligent systems. This thesis aims to address related challenges, following the main research question: “How can we enable effective and efficient gaze-based user interfaces and their development?”. It presents new approaches and methods with the goal of addressing the challenges when using gaze as input in interactive systems. It further outlines a framework for gaze-based multimodal interaction, relating it to multimodal-multisensor and intelligent user interfaces
Quantifizierung von Augenlinsentrübungen mittels Vorderabschnitts-Tomographie (Pentacam®) nach Strahlenbehandlung aufgrund endokriner Orbitopathie
Full text linkZiel dieser Studie war es, herauszufinden, ob die Pentacam®-Scheimpflugkamera zur Erkennung und Quantifizierung strahlungsinduzierter Linsenschädigungen nach retrobulbärer
Bestrahlung geeignet ist. Untersucht wurden 21 bestrahlte Patientinnen und Patienten (40 Augen) sowie 27
unbestrahlte Kontrollpersonen (38 Augen). Die Linsentrübung wurde sowohl objektiv mittels Pentacam® als auch subjektiv anhand der LOCS III-Skala beurteilt. Während die LOCS III-Skala signifikante Unterschiede zwischen den Gruppen aufzeigte, konnten mit keiner der vier Pentacam®-Auswertungsmethoden statistisch signifikante
Differenzen nachgewiesen werden. Allerdings zeigte sich eine lineare Korrelation zwischen der LOCS III-Bewertung und der Pentacam®-Analyse der Gesamtlinse in beiden Gruppen.
Zusammenfassend ist die Pentacam grundsätzlich zur quantitativen Erfassung von Linsentrübungen geeignet, zeigte sich jedoch der etablierten semiquantitativen LOCS III-Skala
in dieser Studie im Hinblick auf die Erkennung von Linsenschäden in der Gruppe der bestrahlten Patienten im Vergleich zur Kontrollgruppe unterlegen. Posterior subkapsuläre Katarakte zeigten sich in dieser Studie bei keinem der bestrahlten Patienten
Belastungsreduktion in der Pflege durch physische Mensch-Roboter-Kooperation
Full text linkKörperliche Belastungen, die über einen längeren Zeitraum durch körperliche Arbeit entstehen, können zur Entwicklung von Muskel-Skelett-Erkrankungen führen. Insbesondere im Gesundheitswesen und hier explizit in der Pflege ist das Risiko für Muskel-Skelett-Erkrankungen im Vergleich zu anderen Berufsgruppen besonders hoch. In dieser Dissertation wurde ein Konzept zur körperlichen Entlastung des Pflegepersonals durch kooperative Roboterassistenz entworfen. Dieses Konzept wurde entwickelt, um auf Basis einer sensorischen Belastungseinschätzung eine kraftbasierte Unterstützung in verschiedenen Phasen ausgewählter Pflegetätigkeiten direkt am Pflegebett anzubieten. In mehreren Laborstudien konnte unter Einbezug der Pflegepraxis gezeigt werden, dass das Assistenzsystem zu einer signifikanten Verringerung der körperlichen Belastung führt. Die Ergebnisse dieser Arbeit unterstreichen das Potenzial robotischer Assistenzsysteme zur Entlastung von Pflegefachpersonen im klinischen Alltag
Komponistinnen aus Rumänien
Full text linkIn Rumänien ist es anders.
Wie viele Komponistinnen in der Gegenwart aktiv sind, erhellt aus Konzertprogrammen unmittelbar. Musik von Frauen muss nicht erst „sichtbar“ gemacht werden. Sie bedarf keiner expliziten Fürsprache, sie braucht keine Schutzräume. Die Zeiten, in denen ein ästhetischer Diskurs auch eine Funktion des Geschlechts der Handelnden wäre, sind in Rumänien vorbei. Das hat Gründe.
Dass Frauen die Teilhabe an allen Lebensbereichen in sozialistischen Ländern leichter möglich war, ist gewiss eine nicht zu unterschätzende Voraussetzung auch für eine
paritätische Partizipation in Kunst und Wissenschaft.
Doch das ist allenfalls eine hinreichende Bedingung.
Viel wichtiger dürfte sein, dass die Parameter eines ästhetischen Leitdiskurses in Rumänien größere Deutungsperspektiven eröffneten als in anderen Ländern, wo der Diskurs enger (und strenger) geführt wurde, limitiert auf Fragen von Material, Technik und Handwerk: Begriffe, die zum Raisonnement einladen, weniger aber zu Spontaneität ermutigen. Und der Körper, der Musik macht und erlebt, gerät dann zur nachgeordneten Instanz.
Doch auch der Bezug zu Tradition und Geschichte ist in Rumänien unbefangener. Es fällt nicht schwer, sich in Bezug zur Historie zu setzen, zu Formen autochthonen Musizierens in Ritus, Liturgie und Geselligkeit. Ethos und Rhythmus, Modi und Metren sind Bausteine, die schlicht adaptiert werden können, die jedoch auch vielfältige Entwicklungen zulassen