859 research outputs found

    Geometrie und Topologie von Trajektorienoptimierung für vollautomatisches Fahren

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    Zur Erschließung allgemeiner Prinzipien für das Themenfeld der Bewegungsplanung für vollautomatisches Fahren wird eine intuitive Problemformulierung als Euler-Lagrange-Modell aufgestellt und zur globalen Optimierung in ein korrespondierendes Hidden-Markov-Modell umgewandelt. Geometrische und topologische Betrachtungen führen zu einer probabilistischen Umgebungsmodellierung in Kombination mit dem C²-Modell und resultieren in universellen Schlussfolgerungen über die Struktur von Verkehrsgeschehen

    Experimental infection of the pig with Mycobacterium ulcerans : a novel model for studying the pathogenesis of Buruli ulcer disease

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    Buruli ulcer (BU) is a slowly progressing, necrotising disease of the skin caused by infection with Mycobacterium ulcerans. Non-ulcerative manifestations are nodules, plaques and oedema, which may progress to ulceration of large parts of the skin. Histopathologically, BU is characterized by coagulative necrosis, fat cell ghosts, epidermal hyperplasia, clusters of extracellular acid fast bacilli (AFB) in the subcutaneous tissue and lack of major inflammatory infiltration. The mode of transmission of BU is not clear and there is only limited information on the early pathogenesis of the disease available.; For evaluating the potential of the pig as experimental infection model for BU, we infected pigs subcutaneously with different doses of M. ulcerans. The infected skin sites were excised 2.5 or 6.5 weeks after infection and processed for histopathological analysis. With doses of 2×107 and 2×106 colony forming units (CFU) we observed the development of nodular lesions that subsequently progressed to ulcerative or plaque-like lesions. At lower inoculation doses signs of infection found after 2.5 weeks had spontaneously resolved at 6.5 weeks. The observed macroscopic and histopathological changes closely resembled those found in M. ulcerans disease in humans.; Our results demonstrate that the pig can be infected with M. ulcerans. Productive infection leads to the development of lesions that closely resemble human BU lesions. The pig infection model therefore has great potential for studying the early pathogenesis of BU and for the development of new therapeutic and prophylactic interventions

    Continual Learning for Class- and Domain-Incremental Semantic Segmentation

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    The field of continual deep learning is an emerging field and a lot of progress has been made. However, concurrently most of the approaches are only tested on the task of image classification, which is not relevant in the field of intelligent vehicles. Only recently approaches for class-incremental semantic segmentation were proposed. However, all of those approaches are based on some form of knowledge distillation. At the moment there are no investigations on replay-based approaches that are commonly used for object recognition in a continual setting. At the same time while unsupervised domain adaption for semantic segmentation gained a lot of traction, investigations regarding domain-incremental learning in an continual setting is not well-studied. Therefore, the goal of our work is to evaluate and adapt established solutions for continual object recognition to the task of semantic segmentation and to provide baseline methods and evaluation protocols for the task of continual semantic segmentation. We firstly introduce evaluation protocols for the class- and domain-incremental segmentation and analyze selected approaches. We show that the nature of the task of semantic segmentation changes which methods are most effective in mitigating forgetting compared to image classification. Especially, in class-incremental learning knowledge distillation proves to be a vital tool, whereas in domain-incremental learning replay methods are the most effective method

    Geographic distribution, age pattern and sites of lesions in a cohort of buruli ulcer patients from the mapé basin of cameroon

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    Buruli ulcer (BU), a neglected tropical disease of the skin, caused by Mycobacterium ulcerans, occurs most frequently in children in West Africa. Risk factors for BU include proximity to slow flowing water, poor wound care and not wearing protective clothing. Man-made alterations of the environment have been suggested to lead to increased BU incidence. M. ulcerans DNA has been detected in the environment, water bugs and recently also in mosquitoes. Despite these findings, the mode of transmission of BU remains poorly understood and both transmission by insects or direct inoculation from contaminated environment have been suggested. Here, we investigated the BU epidemiology in the Mapé basin of Cameroon where the damming of the Mapé River since 1988 is believed to have increased the incidence of BU. Through a house-by-house survey in spring 2010, which also examined the local population for leprosy and yaws, and continued surveillance thereafter, we identified, till June 2012, altogether 88 RT-PCR positive cases of BU. We found that the age adjusted cumulative incidence of BU was highest in young teenagers and in individuals above the age of 50 and that very young children (>5) were underrepresented among cases. BU lesions clustered around the ankles and at the back of the elbows. This pattern neither matches any of the published mosquito biting site patterns, nor the published distribution of small skin injuries in children, where lesions on the knees are much more frequent. The option of multiple modes of transmission should thus be considered. Analyzing the geographic distribution of cases in the Mapé Dam area revealed a closer association with the Mbam River than with the artificial lake

    Experimental infection of the pig with Mycobacterium ulcerans: a novel model for studying the pathogenesis of Buruli ulcer disease.

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    BACKGROUND Buruli ulcer (BU) is a slowly progressing, necrotising disease of the skin caused by infection with Mycobacterium ulcerans. Non-ulcerative manifestations are nodules, plaques and oedema, which may progress to ulceration of large parts of the skin. Histopathologically, BU is characterized by coagulative necrosis, fat cell ghosts, epidermal hyperplasia, clusters of extracellular acid fast bacilli (AFB) in the subcutaneous tissue and lack of major inflammatory infiltration. The mode of transmission of BU is not clear and there is only limited information on the early pathogenesis of the disease available. METHODOLOGY/PRINCIPAL FINDINGS For evaluating the potential of the pig as experimental infection model for BU, we infected pigs subcutaneously with different doses of M. ulcerans. The infected skin sites were excised 2.5 or 6.5 weeks after infection and processed for histopathological analysis. With doses of 2 × 10(7) and 2 × 10(6) colony forming units (CFU) we observed the development of nodular lesions that subsequently progressed to ulcerative or plaque-like lesions. At lower inoculation doses signs of infection found after 2.5 weeks had spontaneously resolved at 6.5 weeks. The observed macroscopic and histopathological changes closely resembled those found in M. ulcerans disease in humans. CONCLUSION/SIGNIFICANCE Our results demonstrate that the pig can be infected with M. ulcerans. Productive infection leads to the development of lesions that closely resemble human BU lesions. The pig infection model therefore has great potential for studying the early pathogenesis of BU and for the development of new therapeutic and prophylactic interventions

    Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires

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    The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of ttt\overline{t}, W+bbW+b\overline{b} and W+ccW+c\overline{c} is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 ±\pm 0.02 \mbox{fb}^{-1}. The WW bosons are reconstructed in the decays WνW\rightarrow\ell\nu, where \ell denotes muon or electron, while the bb and cc quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions

    Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

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    Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a ZZ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 <pT<100< p_{\textrm{T}} < 100 GeV and in the pseudorapidity range 2.5<η<42.5 < \eta < 4. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb1^{-1}. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages
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