Real-time on-board obstacle avoidance for UAVs based on embedded stereo vision

In order to improve usability and safety, modern unmanned aerial vehicles (UAVs) are equipped with sensors to monitor the environment, such as laser-scanners and cameras. One important aspect in this monitoring process is to detect obstacles in the flight path in order to avoid collisions. Since a large number of consumer UAVs suffer from tight weight and power constraints, our work focuses on obstacle avoidance based on a lightweight stereo camera setup. We use disparity maps, which are computed from the camera images, to locate obstacles and to automatically steer the UAV around them. For disparity map computation we optimize the well-known semi-global matching (SGM) approach for the deployment on an embedded FPGA. The disparity maps are then converted into simpler representations, the so called U-/V-Maps, which are used for obstacle detection. Obstacle avoidance is based on a reactive approach which finds the shortest path around the obstacles as soon as they have a critical distance to the UAV. One of the fundamental goals of our work was the reduction of development costs by closing the gap between application development and hardware optimization. Hence, we aimed at using high-level synthesis (HLS) for porting our algorithms, which are written in C/C++, to the embedded FPGA. We evaluated our implementation of the disparity estimation on the KITTI Stereo 2015 benchmark. The integrity of the overall realtime reactive obstacle avoidance algorithm has been evaluated by using Hardware-in-the-Loop testing in conjunction with two flight simulators.Comment: Accepted in the International Archives of the Photogrammetry, Remote Sensing and Spatial Information Scienc

Real-Time On-Board Obstacle Avoidance for UAVs based on Embedded Stereo Vision

In order to improve usability and safety, modern unmanned aerial vehicles (UAVs) are equipped with sensors to monitor the environment, such as laser-scanners and cameras. One important aspect in this monitoring process is to detect obstacles in the flight path in order to avoid collisions. Since a large number of consumer UAVs suffer from tight weight and power constraints, our work focuses on obstacle avoidance based on a lightweight stereo camera setup. We use disparity maps, which are computed from the camera images, to locate obstacles and to automatically steer the UAV around them. For disparity map computation we optimize the well-known semi-global matching (SGM) approach for the deployment on an embedded FPGA. The disparity maps are then converted into simpler representations, the so called U-/V-Maps, which are used for obstacle detection. Obstacle avoidance is based on a reactive approach which finds the shortest path around the obstacles as soon as they have a critical distance to the UAV. One of the fundamental goals of our work was the reduction of development costs by closing the gap between application development and hardware optimization. Hence, we aimed at using high-level synthesis (HLS) for porting our algorithms, which are written in C/C++, to the embedded FPGA. We evaluated our implementation of the disparity estimation on the KITTI Stereo 2015 benchmark. The integrity of the overall real-time reactive obstacle avoidance algorithm has been evaluated by using Hardware-in-the-Loop testing in conjunction with two flight simulators

German evidence-based guidelines for the treatment of Psoriasis vulgaris (short version)

Psoriasis vulgaris is a common and chronic inflammatory skin disease which has the potential to significantly reduce the quality of life in severely affected patients. The incidence of psoriasis in Western industrialized countries ranges from 1.5 to 2%. Despite the large variety of treatment options available, patient surveys have revealed insufficient satisfaction with the efficacy of available treatments and a high rate of medication non-compliance. To optimize the treatment of psoriasis in Germany, the Deutsche Dermatologische Gesellschaft and the Berufsverband Deutscher Dermatologen (BVDD) have initiated a project to develop evidence-based guidelines for the management of psoriasis. The guidelines focus on induction therapy in cases of mild, moderate, and severe plaque-type psoriasis in adults. The short version of the guidelines reported here consist of a series of therapeutic recommendations that are based on a systematic literature search and subsequent discussion with experts in the field; they have been approved by a team of dermatology experts. In addition to the therapeutic recommendations provided in this short version, the full version of the guidelines includes information on contraindications, adverse events, drug interactions, practicality, and costs as well as detailed information on how best to apply the treatments described (for full version, please see Nast et al., JDDG, Suppl 2:S1–S126, 2006; or http://www.psoriasis-leitlinie.de)

STAT5A and STAT5B in hematopoiesis and leukemogenesis

Dissertation - University of Veterinary Medicine Vienna - 2021 The full text is only available to university members. Please log in!The transcription factors STAT5A and STAT5B exert critical roles in hematopoiesis and are deregulated in hematopoietic malignancies. STAT5A and STAT5B share more than 90 % homology at the protein level and were believed to have redundant functions within the hematopoietic system. As gain-of-function mutations in STAT5B, but not in STAT5A, have been uncovered in hematopoietic malignancies, we here studied the underlying molecular mechanism. We investigated the individual roles of STAT5A and STAT5B using BCR/ABL as a leukemia model which signals via STAT5. STAT5B had a drastic impact on cell line transformation and survival, whereas STAT5A exerted minor effects. Stat5b-deficient cell lines rarely evolved, required high levels of BCR/ABL and induced leukemia with a significantly delayed latency. In contrast, Stat5a-deficient cell lines caused a disease comparable to wild type BCR/ABL cells. RNA-seq profiling revealed that STAT5B prominently suppressed IFNα/γ signaling to allow BCR/ABL induced transformation and proliferation. Our results were verified by RNA-seq data of STAT5B-mutated leukemia patient samples. This partly explains the higher frequency of STAT5B mutations in hematopoietic malignancies. In the second part of my thesis, I focused on the roles of STAT5A and STAT5B in hematopoietic and leukemic stem cells. STAT5 is a critical regulator of stem cell self-renewal and engraftment, but the precise functions of STAT5A and STAT5B remained unknown. We found STAT5B, but not STAT5A, to act as a driver for self-renewal and provide an explanation for its dominance – selective STAT5B activation downstream of cytokines and oncogenes. We tested STAT5B target genes revealed from hematopoietic stem cells by single cell RNA-seq for their prognostic relevance in leukemia and identified the surface protein CD9 as a marker for activated STAT5B. Of note, high levels of CD9 represent a negative prognostic marker for leukemia patients harboring STAT5-activating mutations. Our data indicate that CD9-blocking antibodies are a useful treatment to target and eradicate STAT5-driven leukemic stem cells. This thesis emphasizes the need to consider STAT5A and STAT5B as distinct entities in hematopoiesis and leukemogenesis to understand their individual functions to improve therapeutic approaches.Dissertation - University of Veterinary Medicine Vienna - 2021 The full text is only available to university members. Please log in!The transcription factors STAT5A and STAT5B exert critical roles in hematopoiesis and are deregulated in hematopoietic malignancies. STAT5A and STAT5B share more than 90 % homology at the protein level and were believed to have redundant functions within the hematopoietic system. As gain-of-function mutations in STAT5B, but not in STAT5A, have been uncovered in hematopoietic malignancies, we here studied the underlying molecular mechanism. We investigated the individual roles of STAT5A and STAT5B using BCR/ABL as a leukemia model which signals via STAT5. STAT5B had a drastic impact on cell line transformation and survival, whereas STAT5A exerted minor effects. Stat5b-deficient cell lines rarely evolved, required high levels of BCR/ABL and induced leukemia with a significantly delayed latency. In contrast, Stat5a-deficient cell lines caused a disease comparable to wild type BCR/ABL cells. RNA-seq profiling revealed that STAT5B prominently suppressed IFNα/γ signaling to allow BCR/ABL induced transformation and proliferation. Our results were verified by RNA-seq data of STAT5B-mutated leukemia patient samples. This partly explains the higher frequency of STAT5B mutations in hematopoietic malignancies. In the second part of my thesis, I focused on the roles of STAT5A and STAT5B in hematopoietic and leukemic stem cells. STAT5 is a critical regulator of stem cell self-renewal and engraftment, but the precise functions of STAT5A and STAT5B remained unknown. We found STAT5B, but not STAT5A, to act as a driver for self-renewal and provide an explanation for its dominance – selective STAT5B activation downstream of cytokines and oncogenes. We tested STAT5B target genes revealed from hematopoietic stem cells by single cell RNA-seq for their prognostic relevance in leukemia and identified the surface protein CD9 as a marker for activated STAT5B. Of note, high levels of CD9 represent a negative prognostic marker for leukemia patients harboring STAT5-activating mutations. Our data indicate that CD9-blocking antibodies are a useful treatment to target and eradicate STAT5-driven leukemic stem cells. This thesis emphasizes the need to consider STAT5A and STAT5B as distinct entities in hematopoiesis and leukemogenesis to understand their individual functions to improve therapeutic approaches.Dissertation - Veterinärmedizinische Universität Wien - 2021 Aus rechtlichen Gründen sind nicht alle Teile dieser Arbeit frei zugänglich. Der Zugriff auf den elektronischen Volltext ist auf Angehörige der Veterinärmedizinischen Universität Wien beschränkt. Bitte einloggen!Die Transkriptionsfaktoren STAT5A und STAT5B spielen eine entscheidende Rolle in der Hämatopoese und sind in hämatopoetischen Erkrankungen oft dereguliert. STAT5A und STAT5B sind auf Proteinebene zu über 90 % homolog und ihre Funktion im hämatopoietischen System wird als redundant angesehen. Da Gain-of-Function Mutationen in STAT5B, aber nicht in STAT5A, in hämatopoetischen Erkrankungen häufig beschrieben wurden, studieren wir hier den zugrundeliegenden molekularen Mechanismus. Wir untersuchten die individuellen Funktionen von STAT5A und STAT5B und verwendeten dafür BCR/ABL als Leukämiemodell. STAT5B hatte einen drastischen Einfluss auf die Zelllinientransformation und das Überleben, wohingegen STAT5A nur geringe Auswirkungen verursachte. Stat5b-defiziente Zelllinien konnten nur selten etabliert werden, exprimierten mehr BCR/ABL und induzierten signifikant später Leukämie. Im Gegensatz dazu verursachten Stat5a-defiziente Zelllinien eine Leukämie vergleichbar zu Wildtyp-BCR/ABL-Zellen. RNA-Seq-Profiling konnte zeigen, dass primär STAT5B die IFNα/γ Signalwege unterdrückt und dadurch die BCR/ABL induzierte Transformation und Proliferation fördert. Unsere Ergebnisse konnten durch RNA-seq Daten von STAT5B-mutieren LeukämiepatientInnen validiert werden. Wir liefern hiermit einen Teil der Erklärung für STAT5B-Mutationen in hämatopoetischen Erkrankungen. Im zweiten Teil meiner Doktorarbeit fokussiere ich mich auf die Rollen von STAT5A und STAT5B in hämatopoetischen und leukämischen Stammzellen. STAT5 gilt als wichtiger Regulator der Stammzell-Selbsterneuerung und des Anwachsens nach Transplantationen, doch die genauen Funktionen von STAT5A und STAT5B wurden bisher nicht untersucht. Wir konnten zeigen, dass STAT5B, aber nicht STAT5A, ein Treiber für die Selbsterneuerung ist und eine Erklärung für diese Dominanz liefern – eine selektive Aktivierung von STAT5B durch Zytokine und Onkogene. Wir testeten STAT5B-spezifische Gene, welche wir in hämatopoetischen Stammzellen durch Einzelzell-RNA-Seq gefunden haben, auf ihre prognostische Relevanz bei Leukämien und konnten das Oberflächenprotein CD9 als Marker für aktiviertes STAT5B identifizieren. Die CD9-Levels fungieren als prognostischer Marker in Leukämien, die STAT5-aktivierende Mutationen aufweisen. Unsere Daten zeigen, dass CD9-blockierende Antikörper STAT5-getriebene leukämische Stammzellen spezifisch eliminieren können. Die Ergebnisse dieser Dissertation unterstreichen die Notwendigkeit, STAT5A und STAT5B als unterschiedliche Entitäten in der Hämatopoese und der Leukämie zu betrachten, um die zugrundeliegenden molekularen Mechanismen besser zu verstehen und folglich therapeutische Ansätze zu verbessern

STAT5A and STAT5B—Twins with Different Personalities in Hematopoiesis and Leukemia

The transcription factors STAT5A and STAT5B have essential roles in survival and proliferation of hematopoietic cells—which have been considered largely redundant. Mutations of upstream kinases, copy number gains, or activating mutations in STAT5A, or more frequently in STAT5B, cause altered hematopoiesis and cancer. Interfering with their activity by pharmacological intervention is an up-and-coming therapeutic avenue. Precision medicine requests detailed knowledge of STAT5A’s and STAT5B’s individual functions. Recent evidence highlights the privileged role for STAT5B over STAT5A in normal and malignant hematopoiesis. Here, we provide an overview on their individual functions within the hematopoietic system

Revisiting the anatomy of the central nervous system of a hemimetabolous model insect species: the pea aphid Acyrthosiphon pisum

Aphids show a marked phenotypic plasticity, producing asexual or sexual and winged or wingless morphs depending on environmental conditions and season. We describe here the general structure of the brain of various morphs of the pea aphid Acyrthosiphon pisum. This is the first detailed anatomical study of the central nervous system of an aphid by immunocytochemistry (synapsin, serotonin, and several neuropeptides), ethyl-gallate staining, confocal laser scanning microscopy, and three-dimensional reconstructions. The study has revealed well-developed optic lobes composed of lamina, medulla, and lobula complex. Ocelli are only present in males and winged parthenogenetic females. The central complex is well-defined, with a central body divided into two parts, a protocerebral bridge, and affiliated lateral accessory lobes. The mushroom bodies are ill-defined, lacking calyces, and only being visualized by using an antiserum against the neuropeptide orcokinin. The antennal lobes contain poorly delineated glomeruli but can be clearly visualized by performing antennal backfills. On the basis of our detailed description of the brain of winged and wingless parthenogenetic A. pisum females, an anatomical map is now available that should improve our knowledge of the way that these structures are involved in the regulation of phenotypic plasticity

Twins with different personalities : STAT5B-but not STAT5A-has a key role in BCR/ABL-induced leukemia

Deregulation of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway is found in cancer with STAT5A/B controlling leukemic cell survival and disease progression. As mutations in STAT5B, but not STAT5A, have been frequently described in hematopoietic tumors, we used BCR/ABL as model systems to investigate the contribution of STAT5A or STAT5B for leukemogenesis. The absence of STAT5A decreased cell survival and colony formation. Even more drastic effects were observed in the absence of STAT5B. STAT5B-deficient cells formed BCR/ABL(+) colonies or stable cell lines at low frequency. The rarely evolving Stat5b(-/-) cell lines expressed enhanced levels of BCR/ABL oncoprotein compared to wild-type cells. In line, Stat5b(-/-) leukemic cells induced leukemia with a significantly prolonged disease onset, whereas Stat5a(-/-) cells rapidly caused a fatal disease superimposable to wild-type cells. RNA-sequencing (RNA-seq) profiling revealed a marked enhancement of interferon (IFN)-alpha and IFN-gamma signatures in Stat5b(-/-) cells. Inhibition of IFN responses rescued BCR/ABL(+) colony formation of Stat5b(-/-)-deficient cells. A downregulated IFN response was also observed in patients suffering from leukemia carrying STAT5B mutations. Our data define STAT5B as major STAT5 isoform driving BCR/ABL(+) leukemia. STAT5B enables transformation by suppressing IFN-alpha/gamma, thereby facilitating leukemogenesis. Our findings might help explain the high frequency of STAT5B mutations in hematopoietic tumors.Peer reviewe

Automatic Image Processing in the Digital Humanities. A Pre-study for Children Books in the 19th Century

Im C, Mandl T, Helm W, Schmideler S. Automatic Image Processing in the Digital Humanities. A Pre-study for Children Books in the 19th Century. In: Kollmann S, Müller L, Reh S, Dane J, Ruiten T van, BBF, eds. Picture archives and the emergence of visual history of education. ISCHE 40 pre-conference workshop. 3rd workshop "Pictura Paedagogica Online: educational knowledge in images". Berlin: BBF; 2018: 77-86