1,279 research outputs found

    Impacto de las redes de distribución de gas natural en la confiabilidad de sistemas de distribución de energía eléctrica con generación distribuida

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    En este trabajo se desarrolla una metodología que permite cuantificar el impacto de la confiabilidad del sistema de gas natural sobre la con fiabilidad del sistema eléctrico. El impacto se mide mediante una relación entre la energía no suministrada por contingencias en la red de gas natural con la energía no suministrada por las contingencias en la red eléctrica, donde se consideran posibles valores para tasas de fallas y tiempos de reparación de la red de gas natural. Los resultados numéricos indican que en sistemas de distribución con alta penetración de generación distribuida la con fiabilidad de la red de gas natural impacta fuertemente la confiabilidad del sistema eléctrico

    Criterion-Related Validity of Field-Based Fitness Tests in Adults: A Systematic Review

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    We comprehensively assessed the criterion-related validity of existing field-based fitness tests used to indicate adult health (19-64 years, with no known pathologies). The medical electronic databases MEDLINE (via PubMed) and Web of Science (all databases) were screened for studies published up to July 2020. Each original study's methodological quality was classified as high, low and very low, according to the number of participants, the description of the study population, statistical analysis and systematic reviews which were appraised via the AMSTAR rating scale. Three evidence levels were constructed (strong, moderate and limited evidence) according to the number of studies and the consistency of the findings. We identified 101 original studies (50 of high quality) and five systematic reviews examining the criterion-related validity of field-based fitness tests in adults. Strong evidence indicated that the 20 m shuttle run, 1.5-mile, 12 min run/walk, YMCA step, 2 km walk and 6 min walk test are valid for estimating cardiorespiratory fitness; the handgrip strength test is valid for assessing hand maximal isometric strength; and the Biering-Sorensen test to evaluate the endurance strength of hip and back muscles; however, the sit-and reach test, and its different versions, and the toe-to-touch test are not valid for assessing hamstring and lower back flexibility. We found moderate evidence supporting that the 20 m square shuttle run test is a valid test for estimating cardiorespiratory fitness. Other field-based fitness tests presented limited evidence, mainly due to few studies. We developed an evidence-based proposal of the most valid field-based fitness tests in healthy adults aged 19-64 years old.This project was supported by Ministry of Economy, Industry and Competitiveness in the 2017 call for R&D Projects of the State Program for Research, Development and Innovation Oriented to the Challenges of the Company; National Plan for Scientific and Technical Research and of Innovation 2017-2020 (DEP2017-88043-R); and the Regional Government of Andalusia and University of Cadiz: Research and Knowledge Transfer Fund (PPIT-FPI19)

    Search for supersymmetry in electroweak production with photons and large missing transverse energy in pp collisions at √s=8TeV

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    Open Access funded by SCOAP³ - Sponsoring Consortium for Open Access Publishing in Particle Physics.-- et al.Results are reported from a search for supersymmetry with gauge-mediated supersymmetry breaking in electroweak production. Final states with photons and large missing transverse energy ( EmissT ) were examined. The data sample was collected in pp collisions at √s=8TeV with the CMS detector at the LHC and corresponds to 7.4fb. The analysis focuses on scenarios in which the lightest neutralino has bino- or wino-like components, resulting in decays to photons and gravitinos, where the gravitinos escape undetected. The data were obtained using a specially designed trigger with dedicated low thresholds, providing good sensitivity to signatures with photons, EmissT , and low hadronic energy. No excess of events over the standard model expectation is observed. The results are interpreted using the model of general gauge mediation. With the wino mass fixed at 10GeV above that of the bino, wino masses below 710GeV are excluded at 95% confidence level. Constraints are also set in the context of two simplified models, for which the analysis sets the lowest cross section limits on the electroweak production of supersymmetric particles.Funded by SCOAP3.Peer Reviewe

    Search for narrow resonances decaying to dijets in proton-proton collisions at √s=13 TeV

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    et al.A search for narrow resonances in proton-proton collisions at √s=13  TeV is presented. The invariant mass distribution of the two leading jets is measured with the CMS detector using a data set corresponding to an integrated luminosity of 2.4  fb−1. The highest observed dijet mass is 6.1 TeV. The distribution is smooth and no evidence for resonant particles is observed. Upper limits at 95% confidence level are set on the production cross section for narrow resonances with masses above 1.5 TeV. When interpreted in the context of specific models, the limits exclude string resonances with masses below 7.0 TeV, scalar diquarks below 6.0 TeV, axigluons and colorons below 5.1 TeV, excited quarks below 5.0 TeV, color-octet scalars below 3.1 TeV, and W′ bosons below 2.6 TeV. These results significantly extend previously published limits.Peer Reviewe

    Measurements of tt¯ spin correlations and top quark polarization using dilepton final states in pp collisions at √s=8  TeV

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    et al.Measurements of the top quark-antiquark (tt¯) spin correlations and the top quark polarization are presented for tt¯ pairs produced in pp collisions at √s=8  TeV. The data correspond to an integrated luminosity of 19.5  fb−1 collected with the CMS detector at the LHC. The measurements are performed using events with two oppositely charged leptons (electrons or muons) and two or more jets, where at least one of the jets is identified as originating from a bottom quark. The spin correlations and polarization are measured from the angular distributions of the two selected leptons, both inclusively and differentially, with respect to the invariant mass, rapidity, and transverse momentum of the tt¯ system. The measurements are unfolded to the parton level and found to be in agreement with predictions of the standard model. A search for new physics in the form of anomalous top quark chromo moments is performed. No evidence of new physics is observed, and exclusion limits on the real part of the chromo-magnetic dipole moment and the imaginary part of the chromo-electric dipole moment are evaluated.Individuals have received support from the Marie-Curie programme and the European Research Council and EPLANET (European Union); the Leventis Foundation; the A. P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWTBelgium); the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Council of Science and Industrial Research, India; the HOMING PLUS programme of the Foundation for Polish Science, cofinanced from European Union, Regional Development Fund; the OPUS programme of the National Science Center (Poland); the Compagnia di San Paolo (Torino); MIUR project 20108T4XTM (Italy); the Thalis and Aristeia programmes cofinanced by EU-ESF and the Greek NSRF; the National Priorities Research Program by Qatar National Research Fund; the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University (Thailand); the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); and the Welch Foundation, Contract No. C-1845.Peer Reviewe

    Impact of COVID-19 confinement on physical activity and sedentary behaviour in Spanish university students: role of gender

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    During the COVID-19 pandemic, entire populations were instructed to live in home-confinement to prevent the expansion of the disease. Spain was one of the countries with the strictest conditions, as outdoor physical activity was banned for nearly two months. This study aimed to analyse the changes in physical activity and sedentary behaviours in Spanish university students before and during the confinement by COVID-19 with special focus on gender. We also analysed enjoyment, the tools used and motivation and impediments for doing physical activity. An online questionnaire, which included the International Physical Activity Questionnaire Short Form and certain 'ad hoc' questions, was designed. Students were recruited by distributing an invitation through the administrative channels of 16 universities and a total of 13,754 valid surveys were collected. Overall, university students reduced moderate (-29.5%) and vigorous (-18.3%) physical activity during the confinement and increased sedentary time (+52.7%). However, they spent more time on high intensity interval training (HIIT) (+18.2%) and mind-body activities (e.g., yoga) (+80.0%). Adaptation to the confinement, in terms of physical activity, was handled better by women than by men. These results will help design strategies for each gender to promote physical activity and reduce sedentary behaviour during confinement periods.This research was funded by the High Sports Council (Consejo Superior de Deportes, CSD) of the Ministry of Culture and Sports of the Government of Spain, grant number 45/UPB/20. A.E. is a recipient of a grant of the Basque Government (Eusko Jaurlaritza), grant number PRE_2019_1_0373. D.J.-P. is supported by a grant from the Spanish Ministry of Science and Innovation-MINECO, grant number RYC-2014-16938

    ALPHA-fitness test battery: health-related field-based fitness tests assessment in children and adolescents

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    Batería ALPHA-Fitness: test de campo para la evaluación de la condición física relacionada con la salud en niños y adolescentes (DOI:10.3305/nh.2011.26.6.5611)En el presente estudio describe el trabajo desarrollado para la creación de la batería ALPHA-Fitness de test de campo para la evaluación de la condición física relacionada con la salud en niños y adolescentes. La batería ALPHA-Fitness basada en la evidencia incluye los siguientes test: 1) test de ida y vuelta de 20 metros para evaluar la capacidad aeróbica, 2) test de fuerza de prensión manual y 3) test de salto de longitud a pies juntos para evaluar la capacidad músculo-esquelética, y 4) el IMC, 5) el perímetro de la cintura, y 6) los pliegues cutáneos (tríceps y subscapular) para evaluar la composición corporal. Además, se incluyen 2 variantes: i) batería ALPHA-Fitness de alta prioridad. Esta variante incluye todos los tests excepto la medida de pliegues cutáneos, y ii) la batería ALPHA-Fitness extendida, que incluye todos los test y además del test de velocidad y agilidad de 4 x 10 m.Hereby we summarize the work developed by the ALPHA (Assessing Levels of Physical Activity) Study and describe the tests included in the ALPHA health-related fitness test battery for children and adolescents. The evidence-based ALPHA-Fitness test battery include the following tests: 1) the 20 m shuttle run test to assess cardiorespiratory fitness; 2) the handgrip strength and 3) standing broad jump to assess musculoskeletal fitness, and 4) body mass index, 5) waist circumference; and 6) skinfold thickness (triceps and subscapular) to assess body composition. Furthermore, we include two versions: 1) the high priority ALPHA health-related fitness test battery, which comprises all the evidence-based fitness tests except the measurement of the skinfold thickness; and 2) the extended ALPHA health-related fitness tests battery for children and adolescents, which includes all the evidence-based fitness tests plus the 4 x 10 m shuttle run test to assess motor fitness.El estudio ALPHA ha sido financiado con fondos de la Unión Europea (Ref: 2006120), El Ministerio de Educación (EX-2008-0641, EX-2009-0899, AP2008-03806), los fondos FEDER (Acciones Complementarias DEP2007-29933-E), y el Ministerio de Ciencia e Innovación (RYC-2010-05957, CEB09-0005 GREIB, JCI-2010-07055), y la Swedish Lung-Heart Foundation (20090635)

    Iberoamérica en pospandemia : diálogos desde la comunicación y la cultura

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    241 páginasEste libro es fruto de una iniciativa de la Red Iberoamericana de Investigadores, Académicos y Productores Transmedia, que surge en España en 1997, conocida en sus inicios como Red RAVIDA e integrada por investigadores, profesores y realizadores audiovisuales de distintos países. El objetivo de la Red es promover el intercambio de recursos académicos, científicos y humanos a fin de lograr un mayor aprovechamiento del conocimiento dentro de las comunidades de Iberoamérica. A lo largo de los años, las acciones desarrolladas se han traducido en publicaciones, producciones audiovisuales y gestión cultural que muestran y reflexionan sobre diversas experiencias llevadas a cabo en Latinoamérica y España. Repensar los fenómenos de la pandemia y la pospandemia propone entender los retos y desafíos a los que se enfrenta la sociedad ante el escenario complejo que ha vinculado a cada persona, en lo hiperlocal de su morada, con el escenario de un fenómeno mundial. Generar la reflexión desde distintos ámbitos, perspectivas y geografías, a partir del intercambio de experiencias, tiene como intención compartir y socializar conocimientos en torno a la actual coyuntura sociohistórica. Por ello, aportar propuestas de intervención desde tres distintos ámbitos —lo social, lo cultural y la comunicación— revela las distintas miradas sobre esta realidad. Estamos seguros de que este documento visibiliza aciertos y pendientes, por lo que seguramente abrirá nuevos panoramas de reflexión a académicos, investigadores, docentes, artistas, gestores culturales y profesionales de los medios en Iberoamérica

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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