http://hdl.handle.net/10900/42133 Fri, 03 Jul 2026 18:10:30 GMT 2026-07-03T18:10:30Z http://hdl.handle.net/10900/181306 Systematic and taxonomic revision of Late Miocene Eurasian rhinocerotids, with a focus on Chilotherium Ringström, 1924 Kampouridis, Panagiotis Rhinoceroses are amongst the most iconic animals alive today. However, today’s only five existing species constitute only a small fraction of a remarkably diverse lineage that spanned the Cenozoic Era. The group’s extensive fossil record reveals a rich evolutionary history, marked by significant taxonomic and ecomorphological variety. Rhinocerotidae reached their highest diversity during the Miocene, but in spite of their richness many details about their systematics are shrouded in mystery. Beyond the Rhinocerotinae that comprises all extant rhinoceroses, the family includes two extinct groups: the Aceratheriinae, also known as hornless rhinoceroses and the Elasmotheriinae, relatives of the Siberian unicorn. Despite over a century of palaeontological research the phylogeny, biogeography, and ecology of extinct rhinoceroses remain poorly resolved. This Dissertation addresses many of the persisting issues in the systematics of extinct Rhinocerotidae. An important component of this research was to clarify the phylogenetic relationships of Parelasmotherium, a key taxon in the evolutionary history of derived elasmotheriines and revise the systematics of the group as a whole. This was accomplished through the reevaluation of the type species of the genus, Parelasmotherium schansiense, using micro-computed tomography to study previously unknown features in the dentition of the species. These novel data clarify the phylogenetic position of the genus and demonstrate that two taxa previously assigned to Parelasmotherium are not closely related to the type species, necessitating their taxonomic from this genus. The primary focus of this Dissertation, however, was to elucidate the systematics of the chilotheres and resolve the taxonomy of the included species. This was achieved by revising historical material from several fossil sites across Eurasia that belonged to different species. This allowed the verification of some hypothesis about the systematic affinities of the group’ representatives, such as the synonymisation of Teleoceras ponticus, Aceratherium wegneri, and Aceratherium angustifrons with Chilotherium schlosseri from the Upper Miocene of Samos (Greece). It further enabled the rejection of some other past hypotheses like the synonymisation of Chilotherium kowalevskii from the Upper Miocene of Grebeniki (Ukraine) with C. schlosseri, which in fact represent distinct species. The systematics of the group were further improved by redefining the Chilotheriina at the subtribe level and restricting it to the three genera: Chilotherium, Shansirhinus, and Eochilotherium. The latter genus was re-established for the species Eochilotherium samium, which exhibits features distinguishing it from all Chilotherium, as well as Shansirhinus, species. For this purpose, neotypes were designated for the two valid chilothere species from Samos, C. schlosseri and E. samium. The conclusions were further refined by integrating previously neglected chilothere material, which includes elements of the appendicular skeleton and juvenile cranial, mandibular, and dental elements housed in collections across Europe. This provides new insight into the taxonomy and relationships of the chilothere species, suggesting a more complex biogeographical history for the group than previously hypothesised.; Nashörner gehören zu den emblematischsten Tieren der heutigen Zeit. Die lediglich fünf noch existierenden Arten stellen jedoch nur einen kleinen Bruchteil einer höchst diversen und erfolgreichen Evolutionslinie dar, die sich über das gesamte Känozoikum erstreckte. Der umfangreiche Fossilbericht der Gruppe offenbart eine reiche Evolutionsgeschichte, die durch eine signifikante taxonomische und ökomorphologische Vielfalt gekennzeichnet ist. Die Familie der Rhinocerotidae erreichte während des Miozäns ihre höchste Diversität, doch trotz dieses Reichtums sind viele Details ihrer Systematik noch immer ungeklärt. Neben den Rhinocerotinae, welche alle rezenten Nashörner umfassen, beinhaltet die Familie zwei ausgestorbene Gruppen: die Aceratheriinae, auch bekannt als hornlose Nashörner, und die Elasmotheriinae, Verwandte des „Sibirischen Einhorns“. Trotz über eines Jahrhunderts paläontologischer Forschung bleiben die Phylogenie, Biogeographie und Ökologie ausgestorbener Nashörner in großem Maße unklar. Diese Dissertation befasst sich mit vielen der hartnäckigen Probleme in der Systematik der ausgestorbenen Rhinocerotidae. Ein wesentlicher Bestandteil dieser Forschung war die Klärung der phylogenetischen Beziehungen von Parelasmotherium, einem Schlüsseltaxon in der Evolutionsgeschichte der abgeleiteten Elasmotheriinen, sowie die Revision der Systematik dieser Gruppe als Ganzes. Dies wurde durch eine Neubewertung der Typusart der Gattung, Parelasmotherium schansiense, erreicht, wobei Mikro-Computertomographie eingesetzt wurde, um bisher unbekannte Merkmale der Zähne dieser Art zu untersuchen. Diese neuen Daten klären die phylogenetische Position der Gattung und zeigen, dass zwei zuvor Parelasmotherium zugeordnete Taxa nicht eng mit der Typusart verwandt sind, was ihre taxonomische Ausgliederung aus dieser Gattung erforderlich macht. Der Hauptfokus dieser Dissertation lag jedoch bei der Klärung der Systematik der Chilotherien und der Taxonomie der enthaltenen Arten. Dies gelang durch die Revision von historischem Material verschiedener Arten von mehreren Fundstellen aus ganz Eurasien. Dadurch konnten Hypothesen über die systematischen Verwandtschaftsverhältnisse der Vertreter dieser Gruppe überprüft werden, wie etwa die Synonymisierung von Teleoceras ponticus, Aceratherium wegneri und Aceratherium angustifrons mit Chilotherium schlosseri aus dem Obermiozän von Samos (Griechenland). Des Weiteren ermöglichte dies die Ablehnung anderer früherer Hypothesen, wie der Synonymisierung von Chilotherium kowalevskii aus dem Obermiozän von Grebeniki (Ukraine) mit C. schlosseri, die in der Tat unterschiedliche Arten darstellen. Die Systematik der Gruppe wurde zudem durch die Neudefinition der Chilotheriina auf Subtribus-Ebene verbessert, die nun nur noch die drei Gattungen Chilotherium, Shansirhinus und Eochilotherium umfasst. Letztere Gattung wurde für die Art Eochilotherium samium wiedererrichtet, die Merkmale aufweist, die sie von allen Chilotherium- sowie Shansirhinus-Arten unterscheiden. Zudem Zweck wurden Neotypen für die zwei validen Chilotherien Arten aus Samos, C. schlosseri und E. samium, festgelegt. Die Schlussfolgerungen wurden durch den Einbezug von zuvor vernachlässigtem Chilotherien-Material weiter präzisiert, welches Elemente des Appendikularskellets sowie juvenile kraniale, mandibulare und dentale Elemente aus europäischen Sammlungen umfasst. Dies liefert neue Einblicke in die Taxonomie und die Verwandtschaftsverhältnisse der Chilotherien-Arten und deutet auf eine komplexere biogeographische Geschichte der Gruppe hin als bisher angenommen. Fri, 03 Jul 2026 00:00:00 GMT http://hdl.handle.net/10900/181306 2026-07-03T00:00:00Z http://hdl.handle.net/10900/181305 Cell Fate Acquisition in the Early Embryo by MAP Kinase-Mediated Phosphorylation of Transcriptional Regulators Bischoff, Torren Mattis In the process of plant embryogenesis, the fundamental framework for the future plant is established. During this process the initial differences between cells are set in place after the polarized zygote divides and subsequent assignment of cell fate of the apical and basal cell. Critical for these decisions are transcription factors (TF), which are subject to control by modification. One pathway that has been demonstrated to play a critical role in this process is the ERECTA/YODA (ER/YDA) pathway. The TF SCREAM/INDUCER OF CBF EXPRESSION 1 (SCRM/ICE1) has been characterized thoroughly in the context of stomata as critical for correct entry into the cell lineage and subsequent steps. In stomata SCRM is phosphorylated by Mitogen-Activated Protein Kinase 6 (MPK6), a downstream component of the ER/YDA pathway. Phosphorylation of SCRM in stomata leads to decreased stability and in turn ER/YDA activity leads to suppression of stomatal cell fate. However, the role of SCRM hasn’t been characterized thoroughly in embryo development. Examination of SCRM mutants revealed that scrm loss-of-function and scrm-D, a stabilized mutant, show similar phenotype. Yet, in stomata these mutations produce opposite effects on development. Investigation of the role of SCRM in embryo development revealed that it is critical for correct polarization of the embryo. Additionally, SCRM has been shown to function in parallel with WRKY2 to regulate the activation of WUSCHEL HOMEOBOX 8 (WOX8), a TF important for cell fate assignment. Furthermore, we found evidence that phosphorylation of SCRM by MPK6 is critical for zygote elongation and polarization, as non-phosphorylatable SCRM mutants are unable to rescue the scrm phenotype. The phytohormone auxin has been described as critical during the process of assigning cell fate in the 1-cell embryo. The distribution of auxin following zygote division has been extrapolated based on auxin responses. However, analysis of auxin distribution using more direct methods revealed that auxin was distributed evenly, rather than differentially in the 1-cell embryo. The gap in the auxin model opened by these findings and was subsequently filled by IAA8. This INDOLE-3-ACETIC ACID INDUCIBLE (Aux/IAA) has previously been shown to be phosphorylated and in turn stabilized in stress by MPK6. Further analysis of IAA8 in the early embryo revealed that it undergoes differential stabilization in the early embryo, in a pattern corresponding with ER/YDA activity. Consequently, this results in the suppression of the auxin response machinery essentially, thereby establishing an auxin response gradient before a gradient in auxin concentration is established. Additionally, interference with differential stabilization of IAA8 has been shown to result in stochasticity in auxin responses during early embryogenesis. In summary, our findings in my thesis indicate that cellular context plays a pivotal role in the regulation of TFs. Secondly, we expanded the understanding of how the early auxin responses are regulated and established how receptor signaling can directly impact regulatory components of the auxin response machinery.; Die Dissertation ist gesperrt bis zum 21. Mai 2027 ! Fri, 21 May 2027 00:00:00 GMT http://hdl.handle.net/10900/181305 2027-05-21T00:00:00Z http://hdl.handle.net/10900/181230 Haptify: A Measurement-Based System for Quantifying the Quality of Haptic Interfaces Fazlollahi, Farimah Die Dissertation ist gesperrt bis zum 05. März 2028 !; Grounded force-feedback (GFF) devices, exoskeletons, and other haptic robots modulate human movement through carefully engineered mechanical, electrical, and computational designs. Given their significant societal potential and often high cost, it is essential to fairly and efficiently assess the quality of these intimate cyber-physical interfaces. However, existing device specifications and low-level performance metrics often fail to capture the nuanced qualities that expert users perceive during hands-on experimentation. To address this gap, this thesis introduces Haptify, a comprehensive benchmarking system that can thoroughly, fairly, and noninvasively evaluate GFF haptic devices. Haptify integrates multiple sensing modalities---a seven-camera optical motion-capt\-ure system, a custom-built 60-cm-square force plate, and an instrumented end-effector that can be adapted to different devices---to record the interaction between the human hand, the device, and the ground during both passive and active experiments. With this setup, users hold the device end-effector and move it through a series of carefully designed tasks while Haptify measures kinematic and kinetic responses. From this process, we establish six key ways to assess GFF device performance: workspace shape, global free-space forces, global free-space vibrations, local dynamic forces and torques, frictionless surface rendering, and stiffness rendering. These benchmarks enable systematic evaluation and comparison across devices. We first apply Haptify to benchmark two GFF devices produced by 3D Systems: the widely used Touch and the more expensive Touch X. Results reveal that the Touch X offers a slightly smaller workspace than the Touch, but it produces smaller and more predictable free-space forces, reduced vibrations, more consistent dynamic forces and torques, and higher-quality rendering of both frictionless surfaces and stiff virtual objects. To further validate and extend our approach, we conducted a user study with sixteen expert hapticians who used Haptify to evaluate four commercial GFF devices: Novint Falcon, Force Dimension Omega.3, Touch, and Touch X. Experts tested the devices in unpowered mode and across five representative virtual benchmark environments, providing extensive quantitative ratings and qualitative feedback. We distilled recurring themes from their input and analyzed correlations between expert opinions and sensor-based measurements. Our findings show that expert judgments of fundamental haptic quality indicators align closely with the metrics derived from Haptify. Moreover, device performance both unpowered and in active benchmarks can be used to predict its suitability for more complex applications, such as teleoperated surgery. By linking expert assessments with external measurement data, this thesis establishes a combined qualitative--quantitative framework for benchmarking haptic robots. This approach not only enables fair comparison across diverse devices but also establishes a direct connection between objective measurements and the subjective expertise of experienced hapticians. In doing so, it lays the foundation for more rigorous, transparent, and application-relevant evaluation of haptic technologies. Sun, 05 Mar 2028 00:00:00 GMT http://hdl.handle.net/10900/181230 2028-03-05T00:00:00Z http://hdl.handle.net/10900/181222 Analysis and Identification of Per- and Polyfluoroalkyl Substances (PFAS) from Aqueous Film Forming Foams (AFFF) and their Products of Incomplete Destruction using High Resolution Mass Spectrometry Schüßler, Melanie Per- and polyfluoroalkyl substances (PFAS) are a large group of anthropogenic chemicals, produced since the 1940s, which are characterized by unique properties such as high stability, hydrophobicity as well as oleophobicity and surface activity, that make them attractive for a wide range of industrial applications. Their high stability results from the strength of the C-F bond which makes them also very persistent in environmental matrices. For some PFAS, such as perfluoroalkyl acids (PFAAs), toxic effects have been reported, leading to their ban and restriction. Although PFAAs are no longer used in industry, they can still be formed as terminal products of biotransformation of polyfluorinated, non-restricted PFAS precursor compounds. Extensive use of PFAS led to their world-wide distribution in all environmental compartments, and through their use in aqueous film forming foams (AFFF) they can be discharged directly into the environment, resulting in heavily contaminated hot-spots. PFAS used in AFFF do not have to be disclosed by the manufacturers, can show diverse chemical structures, be of anionic, zwitterionic and cationic nature and may be also transformed to PFAAs under environmental conditions. To prevent and manage threats for drinking water resources, AFFF contaminated sites should be efficiently remediated. A prerequisite for effective remediation is a well-characterized extent of the contamination. Since analytical standards are often unavailable for many PFAS, non-target screening (NTS) by high-resolution mass spectrometry (HRMS) can reveal the contamination, and, through semi-quantification (quantitative NTS, qNTS), even estimate its magnitude. Thermal remediation techniques have been discussed as viable options for PFAS remediation, however little is known about thermal behaviour of PFAS and formation of potentially toxic products of incomplete destruction (PIDs), especially for AFFF PFAS. Therefore, in the first part of this dissertation, soil and groundwater from an AFFF contaminated field site in Germany were subjected to a newly developed qNTS workflow, revealing the presence of 124 individual PFAS from 42 subclasses in the soil. The analysis showed that the contamination was diverse and from potentially different AFFF formulations due to fire-fighting acitvities. Semi-quantification revealed that more than 50% of the identified contamination would have been missed without the qNTS approach. Also, most of the contamination was still present in the top meter of the soil, which was attributed to the presence of zwitter- and cationic- precursors which have strong retention in soil due to electrostatic effects. Nevertheless, mostly short-chained, mobile PFAAs were identified in deeper soil layers and groundwater, highlighting the threat to drinking water resources. In the second part of this work, thermal transformation and desorption behaviour of 6:2 FTSAm-Pr-B, the most abundant compound in the soil from the Reilingen field site, was investigated to evaluate the potential of thermal remediation methods to AFFF contaminated soil. Results demonstrated, that 6:2 FTSAm-Pr-B can produce a variety of PIDs in both a closed and open system-setup and that its transformation can be initiated at temperatures ≥ 150 °C. However, a mass balance (MB) approach revealed a gap in the mass balance at temperatures > 150 °C, indicating the presence of additional PIDs that were not detectable with the applied methods. In an open system, no thermal desorption (TD) of 6:2 FTSAm-Pr-B was observed. Instead, transformation was the dominant process. Temperatures, at which transformation was initiated as well as reaction kinetics were found to be strongly dependent on the sorbent material. Reaction kinetics were fastest with granular activated carbon (GAC) and slowest with organic carbon (OC) rich soil, indicating that GAC may facilitate and OC may hinder the reaction. It was further shown that some PIDs of FTSAm-Pr-B were more stable than their precursors and may also be able to thermally desorb. In conclusion, this work demonstrates the importance of quantitative NTS workflows for the characterization of complex contaminations, such as the Reilingen field site. Furthermore, the evaluation of the thermal transformation of 6:2 FTSAm-Pr-B revealed that the application of thermal remediation strategies to contaminated soils is possible, but not straightforward, as a variety of PIDs must be considered and monitored, even in low-temperature applications, aiming for thermal desorption.; Die Dissertation ist gesperrt bis zum 31. Dezember 2026 ! Thu, 31 Dec 2026 00:00:00 GMT http://hdl.handle.net/10900/181222 2026-12-31T00:00:00Z