406 research outputs found

    Obtaining Robust Control and Navigation Policies for Multi-Robot Navigation via Deep Reinforcement Learning

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    Multi-robot navigation is a challenging task in which multiple robots must be coordinated simultaneously within dynamic environments. We apply deep reinforcement learning (DRL) to learn a decentralized end-to-end policy which maps raw sensor data to the command velocities of the agent. In order to enable the policy to generalize, the training is performed in different environments and scenarios. The learned policy is tested and evaluated in common multi-robot scenarios like switching a place, an intersection and a bottleneck situation. This policy allows the agent to recover from dead ends and to navigate through complex environments.Comment: 13 page

    Contact sensitization to essential oils: IVDK data of the years 2010–2019

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    Background: Essential oils (EOs) are widely used in cosmetics, perfumes, massage fluids, aroma therapy and natural medicine. Some EOs contain contact sensitizers. Objectives: To describe the frequency of sensitization to EOs in dermatitis patients presenting in skin clinics including concomitant reactions, to evaluate the EO patch test preparations and to identify patient groups with an increased risk of EO sensitization. Patients and methods: Retrospective analysis of data from the Information Network of Departments of Dermatology (IVDK), 2010-2019. Results: Twelve EOs were patch tested in an aimed manner in 10 930 patients, of whom 908 (8.3%) reacted to at least 1 EO. Only 6 EOs elicited more than 1% positive patch test reactions: ylang ylang (I + II) oil (3.9%), lemongrass oil (2.6%), jasmine absolute (1.8%), sandalwood oil (1.8%), clove oil (1.6%) and neroli oil (1.1%). Concomitant reactions among EOs or to EOs and fragrances were frequent. Among EO-positive patients, women, leg dermatitis patients, patients aged 40 years or more, masseurs and cosmeticians were over-represented. Conclusions: Sensitization to EOs occurs, albeit infrequently in most cases. Masseurs and cosmeticians have an increased risk of sensitization to EOs. Keywords: clinical epidemiology; contact allergy; essential oils; fragrances; patch testin

    Collective dynamics in crystalline polymorphs of ZnCl2_{2}: potential modelling and inelastic neutron scattering study

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    We report a phonon density of states measurement of α\alpha-ZnCl2_{2} using the coherent inelastic neutron scattering technique and a lattice dynamical calculation in four crystalline phases of ZnCl2_{2} using a transferable interatomic potential. The model calculations agree reasonably well with the available experimental data on the structures, specific heat, Raman frequencies and their pressure variation in various crystalline phases. The calculated results have been able to provide a fair description of the vibrational as well as the thermodynamic properties of ZnCl2_{2} in all its four phases.Comment: Accepted in J. Phys.: Condens. Matte

    Update about Oralair® as a treatment for grass pollen allergic rhinitis

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    Sublingual immunotherapy (SLIT) is a well-tolerated, safe, and effective approach to treating allergic rhinitis (AR). Oralair (R) is a five-grass pollen SLIT tablet containing natural pollen allergens from five of the major grass species responsible for seasonal AR due to grass pollen allergy. Recommended use is in a pre-coseasonal regimen, starting daily treatment approximately 4 months before the start of the pollen season, with treatment then continued daily throughout the season; treatment should continue for 3-5 y. Clinical efficacy and safety of Oralair (R) in patients with grass pollen-induced AR has been demonstrated in a comprehensive clinical development program of randomized controlled trials. Effectiveness has been substantiated in subsequent observational studies with sustained efficacy following treatment cessation and a favorable level of adherence, quality of life, benefit, and satisfaction for the patients. Supportive evidence for a benefit in reducing the risk or delaying the development of allergic asthma is emerging

    Impact of climate change on allergic diseases in Germany

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    Background: Allergic diseases, especially inhalant allergies, have reached epidemic levels and environmental factors play an important role in their development. Climate change influences the occurrence, frequency, and severity of allergic diseases. Methods: The contents of this article were selected by the authors and developed section by section according to their expertise and the current state of knowledge. The sections were then discussed and agreed upon amongst all authors. Results: The article highlights direct and indirect effects of climate change on allergies. It goes into detail about the connections between climate change and (new) pollen allergens as well as (new) occupational inhalation allergens, explains the effects of climate change on the clinical picture of atopic dermatitis, discusses the connections between air pollutants and allergies, and provides information about the phenomenon of thunderstorm asthma. Conclusions: There is a need for action in the field of pollen and fungal spore monitoring, allergy and sensitisation monitoring, urban planning from an allergological perspective, and changes in the working environment, among others. This is part of a series of articles that constitute the German Status Report on Climate Change and Health 2023

    Hypersensitivity manifestations to the fruit mango

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    The objectives of this study are 1) To review the published data and document the current knowledge on allergic manifestations to the fruit mango 2) To highlight the two distinct clinical presentations of hypersensitivity reactions caused by mango 3) To discuss the role of cross-reactivity 4) To increase awareness of potentially life threatening complications that can be caused by allergy to mango. An extensive search of the literature was performed in Medline/PubMed with the key terms "mango", "anaphylaxis", "contact dermatitis", "cross-reactivity", "food hypersensitivity", "oral allergy syndrome" and "urticaria". The bibliographies of all papers thus located were searched for further relevant articles. A total of 17 reports describing 22 patients were documented, including ten patients with immediate hypersensitivity reaction and twelve patients with delayed hypersensitivity reaction to mango. Ten of these patients (four with immediate reaction; six with delayed reaction) were from geographical areas cultivating mango, whereas twelve patients (six with immediate reaction; six with delayed reaction) were from the countries where large scale mango cultivation does not occur. The clinical features, pathogenesis and diagnostic modalities of both these presentations are highlighted. The fruit mango can cause immediate and delayed hypersensitivity reactions, as also "oral allergy syndrome". Although rare, it can even result in a life threatening event. Reactions may even occur in individuals without prior exposure to mango, owing to cross reactivity. It is imperative to recognize such a phenomenon early so as to avoid potentially severe clinical reactions in susceptible patients

    Clinical efficacy of omalizumab in chronic spontaneous urticaria is associated with a reduction of FcεRI-positive cells in the skin

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    Background. Treatment with omalizumab, a humanized recombinant monoclonal anti-IgE antibody, results in clinical efficacy in patients with Chronic Spontaneous Urticaria (CSU). The mechanism of action of omalizumab in CSU has not been elucidated in detail. Objectives. To determine the effects of omalizumab on levels of high affinity IgE receptor-positive (FcεRI+) and IgE- positive (IgE+) dermal cells and blood basophils. Treatment efficacy and safety were also assessed. Study design. In a double-blind study, CSU patients aged 18‑75 years were randomized to receive 300 mg omalizumab (n=20) or placebo (n=10) subcutaneously every 4 weeks for 12 weeks. Changes in disease activity were assessed by use of the weekly Urticaria Activity Score (UAS7). Circulating IgE levels, basophil numbers and levels of expression of FcεRI+ and IgE+ cells in the skin and in blood basophils were determined. Results. Patients receiving omalizumab showed a significantly greater decrease in UAS7 compared with patients receiving placebo. At Week 12 the mean difference in UAS7 between treatment groups was -14.82 (p=0.0027), consistent with previous studies. Total IgE levels in serum were increased after omalizumab treatment and remained elevated up to Week 12. Free IgE levels decreased after omalizumab treatment. Mean levels of FcεRI+ skin cells in patients treated with omalizumab 300 mg were decreased at Week 12 compared with baseline in the dermis of both non-lesional and lesional skin, reaching levels comparable with those seen in healthy volunteers (HVs). There were no statistically significant changes in mean FcɛRI+ cell levels in the placebo group. Similar results were seen for changes in IgE+ cells, although the changes were not statistically significant. The level of peripheral blood basophils increased immediately after treatment start and returned to Baseline values after the follow-up period. The levels of FcεRI and IgE expression on peripheral blood basophils were rapidly reduced by omalizumab treatment up to Week 12. Conclusions. Treatment with omalizumab resulted in rapid clinical benefits in patients with CSU. Treatment with omalizumab was associated with reduction in FcɛRI+ and IgE+ basophils and intradermal cells
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