1,359 research outputs found

    Étale Covers and Fundamental Groups of Schematic Finite Spaces

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    [EN] We introduce the category of finite Ă©tale covers of an arbitraryschematic space X and show that, equipped with an appropriate naturalfiber functor, it is a Galois Category. This allows us to define the Ă©tale fundamental group of schematic spaces. If X is a finite model of a schemeS, we show that the resulting Galois theory on X coincides with theclassical theory of finite Ă©tale covers on S, and therefore, we recover the classical Ă©tale fundamental group introduced by Grothendieck. Toprove these results, it is crucial to find a suitable geometric notion ofconnectedness for schematic spaces and also to study their geometric points. We achieve these goals by means of the strong cohomologicalconstraints enjoyed by schematic spaces.PublicaciĂłn en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y LeĂłn (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEĂ“N, ActuaciĂłn:20007-CL - Apoyo Consorcio BUCLE

    Bridging Model and Observed Stellar Spectra

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    Accurate model stellar fluxes are key for the analysis of observations of individual stars or stellar populations. Model spectra differ from real stellar spectra due to limitations of the input physical data and adopted simplifications, but can be empirically calibrated to maximise their resemblance to actual stellar spectra. I describe a least-squares procedure of general use and test it on the MILES library.Comment: 7 pages, 6 figures, accepted for publication in MNRA

    CaracterizaciĂłn de algunas propiedades en tableros de corteza de Pinus pinaster Ait. y tableros de vermiculita expandida

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    The search for new applications to use boards requires innovation of their pro-perties. The improvement of insulation properties, the possibility to regulate the environmental conditions, the improvement of fire resistance and the increase of physical and mechanical properties allow a more diverse use of boards. Using new components in the production of boards and/or component materials also called composites (1), enables the improvement of these properties. This publication analyses different physical and mechanical properties of various types of single-layer boards produced either based on expanded vermiculite particles bonded with soluble silicate glasses (2) or based on lignocelluloses particles bark of "Pinus pinaster" Ait., agglutinated with cement derivatives of magnesium (3), the latter included in the classification of the norm (4). Commercial wood wool boards (5) are used as reference material.La búsqueda de nuevas aplicaciones en el uso de los tableros requiere de la innovación en sus propiedades. Las mejoras en el aislamiento, en la regulación de las condiciones ambientales, en su resistencia al fuego y el incremento en sus propiedades físico-mecánicas, aumentan la diversificación de sus usos. El empleo de nuevas materias en los tableros y/o en los materiales compuestos, denominados composites (1), posibilita la mejora en estas propiedades. Esta publicación analiza diversas propiedades físicas y mecánicas de varios tipos de tableros monocapa, elaborados, por un lado, a base de partículas minerales de vermiculita expandida aglutinadas con silicatos de vidrios solubles (2), y por otro lado, a base de partículas lignocelulósicas de corteza de Pinus pinaster Ait., aglutinadas con cementos derivados del magnesio (3), incluidos ya estos últimos en la clasificación de la norma (4). Como material de referencia se emplean tableros comerciales de virutas de madera (5)

    Tocilizumab in refractory Caucasian Takayasu’s arteritis: a multicenter study of 54 patients and literature review

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    Arteritis de Takayasu; Tocilizumab; Teràpia biològicaArteritis de Takayasu; Tocilizumab; Terapia biológicaTakayasu’s arteritis; Tocilizumab; Biological therapyObjective: To assess the efficacy and safety of tocilizumab (TCZ) in Caucasian patients with refractory Takayasu’s arteritis (TAK) in clinical practice. Methods: A multicenter study of Caucasian patients with refractory TAK who received TCZ. The outcome variables were remission, glucocorticoid-sparing effect, improvement in imaging techniques, and adverse events. A comparative study between patients who received TCZ as monotherapy (TCZMONO) and combined with conventional disease modifying anti-rheumatic drugs (cDMARDs) (TCZCOMBO) was performed. Results: The study comprised 54 patients (46 women/8 men) with a median [interquartile range (IQR)] age of 42.0 (32.5–50.5) years. TCZ was started after a median (IQR) of 12.0 (3.0–31.5) months since TAK diagnosis. Remission was achieved in 12/54 (22.2%), 19/49 (38.8%), 23/44 (52.3%), and 27/36 (75%) patients at 1, 3, 6, and 12 months, respectively. The prednisone dose was reduced from 30.0 mg/day (12.5–50.0) to 5.0 (0.0–5.6) mg/day at 12 months. An improvement in imaging findings was reported in 28 (73.7%) patients after a median (IQR) of 9.0 (6.0–14.0) months. Twenty-three (42.6%) patients were on TCZMONO and 31 (57.4%) on TCZCOMBO: MTX (n = 28), cyclosporine A (n = 2), azathioprine (n = 1). Patients on TCZCOMBO were younger [38.0 (27.0–46.0) versus 45.0 (38.0–57.0)] years; difference (diff) [95% confidence interval (CI) = -7.0 (-17.9, -0.56] with a trend to longer TAK duration [21.0 (6.0–38.0) versus 6.0 (1.0–23.0)] months; diff 95% CI = 15 (-8.9, 35.5), and higher c-reactive protein [2.4 (0.7–5.6) versus 1.3 (0.3–3.3)] mg/dl; diff 95% CI = 1.1 (-0.26, 2.99). Despite these differences, similar outcomes were observed in both groups (log rank p = 0.862). Relevant adverse events were reported in six (11.1%) patients, but only three developed severe events that required TCZ withdrawal. Conclusion: TCZ in monotherapy, or combined with cDMARDs, is effective and safe in patients with refractory TAK of Caucasian origin.The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was partially supported by RETICS Programs, RD08/0075 (RIER), RD12/0009/0013 and RD16/0012 from “Instituto de Salud Carlos III” (ISCIII) (Spain). However, this research did not receive any specific grant from funding agencies in the commercial or not-for-profit sectors

    Modelling and simulation of a lava flow affecting a shore platform: a case study of Montaña de Aguarijo eruption, El Hierro (Canary Islands, Spain)

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    Recent subaerial volcanism at El Hierro Island (Canary Islands, Spain) consists of monogenetic volcanic fields. This volcanism generated cinder cones, tephra air-fall deposits, and lava flows. The lava flows reach several kilometres in length extending through shore platforms and, sometimes, penetrating under the sea level. The volcanic landforms of El Hierro convert it into a natural laboratory for topographic and morphometric modelling and lava flow simulations. We perform the modelling and simulation of the Montaña de Aguarijo eruption, a cinder cone at the NE rift. The associated lava flow channelled through a V-shaped ravine until reaching a cliff, where formed cascades. The flow spread at the cliff base over a platform before reaching the sea modifying the coastline. Different maps were designed to show the results, including the geomorphologic reconstruction of the area affected by this eruption and the lava flow simulations obtained with the Q-LavHA plugin. © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of Journal of Maps
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