2,568 research outputs found

    A Novel Tool for the Absolute End-to-End Calibration of Fluorescence Telescopes -The XY-Scanner

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    Predictive factors of the contracture test for diagnosing malignant hyperthermia in a Brazilian population sample: a retrospective observational study

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    Introduction: Malignant Hyperthermia (MH) is a pharmacogenetic, hereditary and autosomal dominant syndrome triggered by halogenates/succinylcholine. The In Vitro Contracture Test (IVCT) is the gold standard diagnostic test for MH, and it evaluates abnormal skeletal muscle reactions of susceptible individuals (earlier/greater contracture) when exposed to caffeine/halothane. MH susceptibility episodes and IVCT seem to be related to individual features. Objective: To assess variables that correlate with IVCT in Brazilian patients referred for MH investigation due to a history of personal/family MH. Methods: We examined IVCTs of 80 patients investigated for MH between 2004‚Äí2019. We recorded clinical data (age, sex, presence of muscle weakness or myopathy with muscle biopsy showing cores, genetic evaluation, IVCT result) and IVCT features (initial and final maximum contraction, caffeine/halothane concentration triggering contracture of 0.2g, contracture at caffeine concentration of 2 and 32 mmoL and at 2% halothane, and contraction after 100 Hz stimulation). Results: Mean age of the sample was 35¬Ī13.3 years, and most of the subjects were female (n=43 or 54%) and MH susceptible (60%). Of the 20 subjects undergoing genetic investigation, 65% showed variants in RYR1/CACNA1S genes. We found no difference between the positive and negative IVCT groups regarding age, sex, number of probands, presence of muscle weakness or myopathy with muscle biopsy showing cores. Regression analysis revealed that the best predictors of positive IVCT were male sex (+12%), absence of muscle weakness (+20%), and personal MH background (+17%). Conclusions: Positive IVCT results have been correlated to male probands, in accordance with early publications. Furthermore, normal muscle strength has been confirmed as a significant predictor of positive IVCT while investigating suspected MH cases.Funda√ß√£o de Amparo √† Pesquisa do Estado de S√£o Paulo (FAPESP)0012021_06180-

    AugerPrime Surface Detector Electronics

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    International audienceOperating since 2004, the Pierre Auger Observatory has led to major advances in our understanding of the ultra-high-energy cosmic rays. The latest findings have revealed new insights that led to the upgrade of the Observatory, with the primary goal of obtaining information on the primary mass of the most energetic cosmic rays on a shower-by-shower basis. In the framework of the upgrade, called AugerPrime, the 1660 water-Cherenkov detectors of the surface array are equipped with plastic scintillators and radio antennas, allowing us to enhance the composition sensitivity. To accommodate new detectors and to increase experimental capabilities, the electronics is also upgraded. This includes better timing with up-to-date GPS receivers, higher sampling frequency, increased dynamic range, and more powerful local processing of the data. In this paper, the design characteristics of the new electronics and the enhanced dynamic range will be described. The manufacturing and test processes will be outlined and the test results will be discussed. The calibration of the SD detector and various performance parameters obtained from the analysis of the first commissioning data will also be presented

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5‚Äď7 vast areas of the tropics remain understudied.8‚Äď11 In the American tropics, Amazonia stands out as the world‚Äôs most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13‚Äď15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon‚Äôs biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region‚Äôs vulnerability to environmental change. 15%‚Äď18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    12,500+ and counting: biodiversity of the Brazilian Pampa

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    Knowledge on biodiversity is fundamental for conservation strategies. The Brazilian Pampa region, located in subtropical southern Brazil, is neglected in terms of conservation, and knowledge of its biodiversity is fragmented. We aim to answer the question: how many, and which, species occur in the Brazilian Pampa? In a collaborative effort, we built species lists for plants, animals, bacteria, and fungi that occur in the Brazilian Pampa. We included information on distribution patterns, main habitat types, and conservation status. Our study resulted in referenced lists totaling 12,503 species (12,854 taxa, when considering infraspecific taxonomic categories [or units]). Vascular plants amount to 3,642 species (including 165 Pteridophytes), while algae have 2,046 species (2,378 taxa) and bryophytes 316 species (318 taxa). Fungi (incl. lichenized fungi) contains 1,141 species (1,144 taxa). Animals total 5,358 species (5,372 taxa). Among the latter, vertebrates comprise 1,136 species, while invertebrates are represented by 4,222 species. Our data indicate that, according to current knowledge, the Pampa holds approximately 9% of the Brazilian biodiversity in an area of little more than 2% of Brazil’s total land. The proportion of species restricted to the Brazilian Pampa is low (with few groups as exceptions), as it is part of a larger grassland ecoregion and in a transitional climatic setting. Our study yielded considerably higher species numbers than previously known for many species groups; for some, it provides the first published compilation. Further efforts are needed to increase knowledge in the Pampa and other regions of Brazil. Considering the strategic importance of biodiversity and its conservation, appropriate government policies are needed to fund studies on biodiversity, create accessible and constantly updated biodiversity databases, and consider biodiversity in school curricula and other outreach activities

    The number of muons measured in hybrid events detected by the Pierre Auger Observatory

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    Deep-Learning-Based Cosmic-Ray Mass Reconstruction Using the Water-Cherenkov and Scintillation Detectors of AugerPrime

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    At the highest energies, cosmic rays can be detected only indirectly by the extensive air showers they create upon interaction with the Earth\u27s atmosphere. While high-statistics measurements of the energy and arrival directions of cosmic rays can be performed with large surface detector arrays like the Pierre Auger Observatory, the determination of the cosmic-ray mass on an event-by-event basis is challenging. Meaningful physical observables in this regard include the depth of maximum of air-shower profiles, which is related to the mean free path of the cosmic ray in the atmosphere and the shower development, as well as the number of muons that rises with the number of nucleons in a cosmic-ray particle. In this contribution, we present an approach to determine both of these observables from combined measurements of water-Cherenkov detectors and scintillation detectors, which are part of the AugerPrime upgrade of the Observatory. To characterize the time-dependent signals of the two detectors both separately as well as in correlation to each other, we apply deep learning techniques. Transformer networks employing the attention mechanism are especially well-suited for this task. We present the utilized network concepts and apply them to simulations to determine the precision of the event-by-event mass reconstruction that can be achieved by the combined measurements of the depth of shower maximum and the number of muons

    Constraints on metastable superheavy dark matter coupled to sterile neutrinos with the Pierre Auger Observatory

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    International audienceDark matter particles could be superheavy, provided their lifetime is much longer than the age of the universe. Using the sensitivity of the Pierre Auger Observatory to ultra-high energy neutrinos and photons, we constrain a specific extension of the Standard Model of particle physics that meets the lifetime requirement for a superheavy particle by coupling it to a sector of ultra-light sterile neutrinos. Our results show that, for a typical dark coupling constant of 0.1, the mixing angle őłm\theta_m between active and sterile neutrinos must satisfy, roughly, őłm‚Č≤2.5√ó10‚ąí6(MX/109¬†GeV)‚ąí2\theta_m \lesssim 2.5\times 10^{-6}(M_X/10^9~\mathrm{GeV})^{-2} for a mass MXM_X of the dark-matter particle between 2.3√ó1082.3\times 10^8 and 1011¬†10^{11}~GeV

    Edge detection in biphasic flow images of an experimental natural circulation circuit by the FUNED (Fuzzy Number Edge Detector) method

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    Este trabalho aplicou o m√©todo FUNED (do ingl√™s \"Fuzzy Number Edge Detector\") que √© baseado em n√ļmeros Fuzzy para detec√ß√£o de contornos em um conjunto de imagens digitais de escoamento bif√°sico obtidas em experimentos no Circuito de Circula√ß√£o Natural (CCN) do Instituto de Pesquisas Energ√©ticas e Nucleares (IPEN). O algoritmo se baseia na utiliza√ß√£o de cada pixel da imagem adquirida como um n√ļmero Fuzzy para gerar uma imagem que permita mostrar a pertin√™ncia do pixel em rela√ß√£o √†s regi√Ķes de borda e fundo. A imagem-pertin√™ncia gerada √© utilizada como base para a identifica√ß√£o das bordas, onde um pixel branco significa valores acima do limiar e um pixel preto indica valores abaixo desse valor, processo conhecido como binariza√ß√£o da imagem. Ap√≥s encontrar-se o limiar √≥timo, √© aplicada a t√©cnica de supress√£o de n√£o-m√°ximos para criar uma borda mais fina. As imagens finais do m√©todo s√£o comparadas com imagens idealmente classificadas (constru√≠das pixel a pixel por um especialista). A mesma compara√ß√£o foi realizada utilizando-se o cl√°ssico detector de bordas de Canny, permitindo-se mostrar a efici√™ncia do detector de bordas FUNED. Os resultados mostraram que o m√©todo FUNED detectou corretamente entre 19% e 25% dos pixels que foram idealmente classificados como borda pelo especialista e, de forma complementar detectou corretamente entre 96% e 98% dos pixels classificados como fundo. O detector de Canny foi aplicado nas mesmas imagens e sob a mesma an√°lise, apresentou um percentual de acertos entre 25% e 39% na predi√ß√£o do que era borda e complementarmente, entre 98% e 99% do que era fundo.This work applied the FUNED method (Fuzzy Number Edge Detector), which is based on Fuzzy numbers for contour detection in a set of digital images of twophase flow obtained in experiments in the Natural Circulation Circuit (CCN) of the Instituto de Pesquisas Energ√©ticas e Nucleares (IPEN). The algorithm uses each pixel of acquired image as a fuzzy number to generate an image that shows the pixel pertinence in relation to the border and background regions. The generated membership-image is used as a basis for the identification of edges, where a white pixel denotes values above the threshold and black pixel denotes values below this value, a process known as image binarization. After finding the optmal threshold, the non-maximum suppression technique is applied, allowing creating a thinner edge detainment. The final image of the method is compared with an ideally classified image, constructed pixel by pixel by an expert. The same comparison was performed with the classic Canny edge detector, showing the FUNED edge detector efficiency. The results showed that the FUNED method conectly detected between 19% and 25% of the pixels that were classified as edge by the specialist and, in a complementary way, conectly detected between 96% and 98% of pixels that were classified as background. The Canny detector was Applied to the same images and, under the same analysis, presented correctly detected between 25% and 39% of what was edge and, additionally, between 98% and 99% of what was background
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