1,249 research outputs found

    El entrenamiento intervalado de alta intensidad mejora el rendimiento específico en los atletas de taekwondo

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    [ES] Los métodos de entrenamiento específicos son un aspecto importante en la preparación de los atletas de taekwondo. El propósito de este estudio fue investigar el efecto de un programa de entrenamiento intervalado de alta intensidad (EIAI) de corta duración con técnicas específicas de taekwondo sobre el rendimiento anaeróbico. Doce atletas de taekwondo fueron asignados al azar a un grupo control (n=6) o grupo experimental (n=6). El protocolo experimental consistió en 3 bloques de 6 series de esfuerzo total de 10 segundos, con recuperación pasiva de 10 segundos entre series e intervalos de descanso de 1 minuto entre bloques, realizado 3 días por semana durante 4 semanas. Se realizó un análisis de varianza de tres vías (ANOVA) (grupo, serie y tiempo) con mediciones repetidas en los dos últimos factores para comparar el rendimiento durante cada serie de la prueba Frequency Speed Kick Test(FSKT) y un ANOVA de dos vías (grupo y tiempo) con mediciones repetidas se utilizó para comparar el número total de patadas y el índice de fatiga de patadas (IFP). Ambos grupos mantuvieron su entrenamiento regular de taekwondo, que era exactamente el mismo. Antes y después del programa de entrenamiento, los atletas realizaron el FSKT. El grupo experimental aumentó el rendimiento (p <0,01) en cada una de las cinco series de FSKT y en el número total de patadas (p <0,001). No se observó diferencia estadística en el grupo control después de 4 semanas o entre el grupo control y el grupo experimental en ningún momento. Un programa de EIAI de corta duración con técnicas específicas de taekwondo mejoró el rendimiento anaeróbico medido a través del FSKT. Sin embargo, el índice de fatiga no cambió.[EN] Specific training methods is an important aspect in the preparation of taekwondo athletes.The purpose of this study was to investigate the effect of a short-duration high-intensity interval training (HIIT) program with specific taekwondo techniques on anaerobic performance.Twelve taekwondo athletes were randomized into a control (n=6) or experimental groups (n=6). The experimental protocol consisted of 3 blocks of 6 sets of 10s all-out effort, with 10s passive recovery between sets and 1-min rest interval between blocks, conducted 3 days per week during 4-weeks. A three-way analysis of variance (ANOVA) (group, set and moment) with repeated measurements in the two last factors was conducted to compare the performance during each set of the Frequency Speed Kick Test (FSKT), and an ANOVA two-way (group and moment) with repeated measurements was used to compare the total number of kicks and kick decrement index (KDI). Both groups maintained their regular taekwondo training, which was exactly the same. Before and after the training program the athletes performed the FSKT.The experimental group increased (p<0.01) performance in each of the five sets of the FSKT and in the total number of kicks (p<0.001). No statistical difference was observed in the control group after 4-weeks or between the control and experimental group in any moment. A short-duration HIIT program with specific taekwondo techniques improved anaerobic performance measured through the FSKT. However, the fatigue index did not change.[PT] Os métodos de treinamento específicos são um aspecto importante na preparação física dos atletas de taekwondo. O propósito deste estudo foi investigar o efeito de um programa de treinamento intervalado de alta intensidade (TIAI), de curta duração, com técnicas específicas de taekwondo sobre o desempenho anaeróbio. Doze atletas de taekwondo foram alocados aleatoriamente a um grupo controle (n=6) ou a um grupo experimental (n=6). O protocolo experimental consistiu em 3 blocos de 6 séries de esforço com duração de 10 segundos, com recuperação passiva de 10 segundos entre as séries e intervalos de descanso de 1 minuto entre os blocos, realizado 3 dias por semana durante 4 semanas. Foi utilizada a análise de variância (ANOVA) a três fatores (grupo, série e tempo) com medidas repetidas nos dois últimos fatores para comparar o desempenho durante cada série do Frequency Speed Kick Test (FSKT) e uma ANOVA a dois fatores (grupo e tempo) com medidas repetidas foi utilizada para comparar o número total de chutes e o índice de fadiga de chutes (IFC). Os dois grupos mantiveram seu treinamento regular de taekwondo, o qual era exatamente o mesmo. Antes e depois do programa de treinamento os atletas realizaram o FSKT. O grupo experimental aumentou o desempenho (p <0,01) em cada uma das cinco séries do FSKT e no número total de chutes (p<0,001). Não foi observada diferença estatística no grupo controle depois de 4 semanas ou entre o grupo controle e o grupo experimental em nenhum momento. Um programa de TIAI, de curta duração, com técnicas específicas de taekwondo melhorou o desempenho anaeróbio medido por meio do FSKT. Contudo, o IFC não mudou

    Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

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    A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

    Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

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    A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

    The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

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    Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase&nbsp;1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation&nbsp;disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age&nbsp; 6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score&nbsp; 652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc&nbsp;= 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N&nbsp;= 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in&nbsp;Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in&nbsp;Asia&nbsp;and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

    Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

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    Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| &lt; 0.03 at 95% confidence level. [Figure not available: see fulltext.

    Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at root s=13 TeV

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    MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

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    Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

    Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

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    The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

    Search for Physics beyond the Standard Model in Events with Overlapping Photons and Jets

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    Results are reported from a search for new particles that decay into a photon and two gluons, in events with jets. Novel jet substructure techniques are developed that allow photons to be identified in an environment densely populated with hadrons. The analyzed proton-proton collision data were collected by the CMS experiment at the LHC, in 2016 at root s = 13 TeV, and correspond to an integrated luminosity of 35.9 fb(-1). The spectra of total transverse hadronic energy of candidate events are examined for deviations from the standard model predictions. No statistically significant excess is observed over the expected background. The first cross section limits on new physics processes resulting in such events are set. The results are interpreted as upper limits on the rate of gluino pair production, utilizing a simplified stealth supersymmetry model. The excluded gluino masses extend up to 1.7 TeV, for a neutralino mass of 200 GeV and exceed previous mass constraints set by analyses targeting events with isolated photons.Peer reviewe
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