1,742 research outputs found

    Decision making and skill development In youth football players

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    Este artículo presenta como se desarrolla la toma de decisiones y la habilidad técnica en jugadores con alto nivel de pericia desde los 6-7 a 13-14 años. El marco teórico está basado en la perspectiva de los sistemas dinámicos y la enseñanza comprensiva de los deportes. Se tomó como muestra a 57 jugadores del primer equipo de cada categoría de edad del Albacete Balompié: prebenjamín, benjamín, alevín e infantil. El instrumento usado fue la Herramienta de Evaluación del Rendimiento de Juego (HERJ), que mide la toma de decisiones y la ejecución, incluyendo el análisis ecológico atendiendo a principios tácticos (Bayer, 1992), comparando la situación en el juego con la decisión aplicada. Los resultados se basan en el análisis inferencial y correlacional. La evolución del rendimiento de juego se orienta desde el ataque hasta la defensa. Se han encontrado diferencias significativas en las variables entre las cuatro categorías de formación estudiadas, especialmente en el principio táctico de progresar hacia la portería contraria y en el desmarque, así como en el marcaje y la ayuda en defensa.This paper presents how decision-making and skills are developed in high level of expertise players from 6-7 to 13-14 years. The framework is based on the dynamical systems and teaching games for understanding approaches. Participants were 57 first team players of each age (n = 13 to 16) of Albacete Balompié: U-8, U-10, U-12 and U-14. The Game Performance Assessment Tool (GPET) was the instrument used for assessment, which measures decision-making and execution from an ecological view in relation to tactical principles (Bayer, 1992), comparing the game situation with the decision applied. The results are based on inferential and correlation analysis. The evolution of knowledge evolves attack to defensive. We have found significant differences in variables between the four age categories studied. These differences have been shown in attack: the progress toward goal tactical principle and shake off; on defence: marking and cover (off-ball defenders)

    Visual behavior influence on decision in volleyball blocking

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    El objetivo del presente estudio fue conocer la influencia del comportamiento visual (localización, número y duración de las fijaciones visuales) sobre la toma de decisiones en la acción del bloqueo en voleibol. Se analizó el comportamiento visual de 38 jugadoras de voleibol (23.9 4.2 años), que competían de manera federada, mediante el sistema de registro de movimientos oculares (Mobile Eye) durante la visualización de secuencias de video proyectadas a tamaño real. Los modelos de regresión obtenidos muestran que se obtienen mayores porcentajes de acierto cuando la duración de las fijaciones es reducida en las zonas HC y CB, y cuando aumenta el número de fijaciones en la zona BM y disminuye en la zona CBThe purpose of this study was to determine the influence of visual behaviour (visual fixation location, number and duration) on decision-making in volleyball blocking. The visual behavior of 38 volleyball players (23.9 4.2 years), who took part in federated competition, was analyzed with the eye tracking system (Mobile Eye) during visualization of real size video sequences. Regression models show that higher success percentages were obtained when the duration of fixations is low in HC and CB areas, and when the number of fixations increases in BM zone and decreases in CB zon

    Influencia del modelo de Educación Deportiva en las necesidades psicológicas básicas

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    Tomando la teoría de la Autodeterminación como marco, el objetivodel estudio fue conocer el impacto del modelo de Educación Deportivaen la satisfacción de las necesidades psicológicas básicas en alumnos deEducación Secundaria en Educación Física. Para ello se seleccionaron dosgrupos de alumnos de entre 15 y 17 años: un grupo experimental (n=43)que desarrolló un programa de intervención basado en el modelo de EducaciónDeportiva de 19 sesiones, y un grupo de control (n=43) que cursó unprograma de 19 sesiones de Educación Física tradicional. Se tomaron medidaspre- y pos-test en ambos grupos. Los resultados hallaron mejoras significativasen la satisfacción de competencia en los alumnos que utilizaronel modelo de Educación Deportiva. Se discutieron los resultados obtenidossubrayando la idoneidad del modelo de Educación Deportiva para favorecerla satisfacción de las necesidades psicológicas básicas en Educación Física

    Direct Glutamatergic Signaling From Midbrain Dopaminergic Neurons Onto Pyramidal Prefrontal Cortex Neurons

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    The dopaminergic neurons of the ventral tegmental area (VTA) have been identified with the ability to co-release dopamine and glutamate. This ability was first documented in the nucleus accumbens but showed to be absent in the dorsal striatum. Recently the ability to release glutamate from a subpopulation of the VTA dopaminergic neurons has been shown to control the prefrontal cortex (PFC) excitation through the exclusive innervation of GABAergic fast spiking interneurons. Here, using an optogenetic approach, we expand this view by presenting that the VTA dopaminergic neurons do not only innervate interneurons but also pyramidal PFC neurons. This finding opens the range of possibilities for the VTA dopaminergic neurons to modulate the activity of PFC

    Evaluating the controlled reopening of nightlife during the COVID-19 pandemic : a matched cohort study in Sitges, Spain, in May 2021 (Reobrim Sitges)

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    To assess the impact of relaxing the state of alarm restrictions on SARS-CoV-2 infections at 14 days among people attending reopened nightclub venues. Matched cohort study with a paired control group (1:5 ratio). Five small nightclubs with indoor areas and outdoor terraces, in a nightlife-restricted area in Sitges, Spain, on 20 May 2021. Wearing masks was mandatory, drinking was allowed and social distance was not required. Volunteers were selected through a convenience sampling. To attend the event, participants were required to be older than 17 years, with a negative rapid antigen diagnostic test (Ag-RDT) on the same afternoon, without a positive reverse-transcription PCR (RT-PCR) or Ag-RDT and/or symptoms associated with COVID-19 in the previous 7 days, to not having knowingly been in close contact with someone infected in the previous 10 days and to not have knowingly had close contact with someone with a suspicion of COVID-19 in the previous 48 hours. A control group was paired by exact age, gender, residence municipality, socioeconomic index, previous SARS-CoV-2-confirmed infection and vaccination status, in a 1:5 ratio, from the primary care electronic health records. Evidence of infection at electronic health records by SARS-CoV-2 at 14-day follow-up. Among the 391 participants (median age 37 years; 44% (n=173) women), no positive SARS-CoV-2 cases were detected at 14 days, resulting in a cumulative incidence estimation of 0 (95% CI 0 to 943) per 100 000 inhabitants. In the control group, two cases with RT-PCR test were identified, resulting in a cumulative incidence of 102.30 (12.4 to 369) per 100 000 inhabitants. Nightlife attendance under controlled conditions and with a requirement for a negative Ag-RDT was not associated with increased transmissibility of SARS-CoV-2 in a pandemic context of low infection rates. In such circumstances, secure opening of the nightlife sector was possible, under reduced capacity and controlled access by Ag-RDT, and environments where compliance with sanitary measures are maintainable

    Experimental and theoretical assessment of native oxide in the superconducting TaN

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    In this manuscript, we show through an experimental-computational proof of concept the native oxide formation into superconducting TaN films. First, TaN was synthesized at an ultra-high vacuum system by reactive pulsed laser deposition and characterized in situ by X-ray photoelectron spectroscopy. The material was also characterized ex situ by X-ray diffraction, transmission electron microscopy, and the four-point probe method. It was detected that TaN contained considerable oxygen impurities (up to 26 %O) even though it was grown in an ultra-high vacuum chamber. Furthermore, the impurified TaN evidence a face-centered cubic crystalline structure only and exhibits superconductivity at 2.99 K. To understand the feasibility of the native oxide in TaN, we study the effect of incorporating different amounts of O atoms in TaN using ab-initio calculations. A thermodynamic stability analysis shows that a TaOxN1-x model increases its stability as oxygen is added, demonstrating that oxygen may always be present in TaN, even when obtained at ultra-high vacuum conditions. All analyzed models exhibit metallic behavior. Charge density difference maps reveal that N and O atoms have a higher charge density redistribution than Ta atoms. The electron localization function maps and line profiles indicate that Ta-O and Ta-N bonds are mainly ionic. As expected, stronger ionic behavior is observed in the Ta-O bonds due to the electronegativity difference between O and N atoms. Recent evidence points to superconductivity in bulk TaO, confirming the asseverations of superconductivity in our samples. The results discussed here highlight the importance of considering native oxide when reporting superconductivity in TaN films since the TaO regions formed in the compound may be key to understanding the different critical temperatures reported in the literature.Comment: 23 pages, 7 figure

    Microvascular cutaneous coverage in wounds that expose the Achilles tendon: case report

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    Achilles tendon rupture, being one of the main tendon ruptures present, surgery being the most favourable option even taking into account complications such as infections and skin necrosis, it is necessary to develop techniques which help to reduce complications and increase benefits. The methods follow-up of 2 cases of patients with skin defects in the region of the Achilles tendon in patients who were treated at the "Luis Guillermo lbarra lbarra" national rehabilitation institute during the period 2020-2021 in the Traumatology service, treated with radial free flap forearm, using the description of the most used flaps in the literature. Results in both cases integrity of the free radial forearm flap in its entirety, functional recovery for walking, ability to put shoes back on, and without the need for reoperation, as well as a high level of satisfaction by patients. Conclusions if we are talking about an Achilles tendon rupture with a significant skin defect, the free radial forearm flap is an adequate option, if we are talking about a complete defect, the composite flap is the best option, remember that the decision on what type of flap will be used will depend on of the size of the lesion

    The unidentified TeV source (TeVJ2032+4130) and surrounding field: Final HEGRA IACT-System results

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    The unidentified TeV source in Cygnus is now confirmed by follow-up observations from 2002 with the HEGRA stereoscopic system of Cherenkov Telescopes. Using all data (1999 to 2002) we confirm this new source as steady in flux over the four years of data taking, extended with radius 6.2 arcmin (+-1.2 arcmin (stat) +-0.9 arcmin (sys)) and exhibiting a hard spectrum with photon index -1.9. It is located in the direction of the dense OB stellar association, Cygnus OB2. Its integral flux above energies E>1 TeV amounts to \~5% of the Crab assuming a Gaussian profile for the intrinsic source morphology. There is no obvious counterpart at radio, optical nor X-ray energies, leaving TeVJ2032+4130 presently unidentified. Observational parameters of this source are updated here and some astrophysical discussion is provided. Also included are upper limits for a number of other interesting sources in the FoV, including the famous microquasar Cygnus X-3.Comment: 7 pages, 3 figures. Accepted for publication in Astronomy & Astrophysic

    Measurement of the Crab Nebula spectrum over three decades in energy with the MAGIC telescopes

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    The MAGIC stereoscopic system collected 69 hours of Crab Nebula data between October 2009 and April 2011. Analysis of this data sample using the latest improvements in the MAGIC stereoscopic software provided an unprecedented precision of spectral and night-by-night light curve determination at gamma rays. We derived a differential spectrum with a single instrument from 50 GeV up to almost 30 TeV with 5 bins per energy decade. At low energies, MAGIC results, combined with Fermi-LAT data, show a flat and broad Inverse Compton peak. The overall fit to the data between 1 GeV and 30 TeV is not well described by a log-parabola function. We find that a modified log-parabola function with an exponent of 2.5 instead of 2 provides a good description of the data (χ2=35/26\chi^2=35/26). Using systematic uncertainties of red the MAGIC and Fermi-LAT measurements we determine the position of the Inverse Compton peak to be at (53 ±\pm 3stat + 31syst -13syst) GeV, which is the most precise estimation up to date and is dominated by the systematic effects. There is no hint of the integral flux variability on daily scales at energies above 300 GeV when systematic uncertainties are included in the flux measurement. We consider three state- of-the-art theoretical models to describe the overall spectral energy distribution of the Crab Nebula. The constant B-field model cannot satisfactorily reproduce the VHE spectral measurements presented in this work, having particular difficulty reproducing the broadness of the observed IC peak. Most probably this implies that the assumption of the homogeneity of the magnetic field inside the nebula is incorrect. On the other hand, the time-dependent 1D spectral model provides a good fit of the new VHE results when considering a 80 {\mu}G magnetic field. However, it fails to match the data when including the morphology of the nebula at lower wavelengths.Comment: accepted by JHEAp, 9 pages, 6 figure

    MAGIC observations of MWC 656, the only known Be/BH system

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    Context: MWC 656 has recently been established as the first observationally detected high-mass X-ray binary system containing a Be star and a black hole (BH). The system has been associated with a gamma-ray flaring event detected by the AGILE satellite in July 2010. Aims: Our aim is to evaluate if the MWC 656 gamma-ray emission extends to very high energy (VHE > 100 GeV) gamma rays. Methods. We have observed MWC 656 with the MAGIC telescopes for \sim23 hours during two observation periods: between May and June 2012 and June 2013. During the last period, observations were performed contemporaneously with X-ray (XMM-Newton) and optical (STELLA) instruments. Results: We have not detected the MWC 656 binary system at TeV energies with the MAGIC Telescopes in either of the two campaigns carried out. Upper limits (ULs) to the integral flux above 300 GeV have been set, as well as differential ULs at a level of \sim5% of the Crab Nebula flux. The results obtained from the MAGIC observations do not support persistent emission of very high energy gamma rays from this system at a level of 2.4% the Crab flux.Comment: Accepted for publication in A&A. 5 pages, 2 figures, 2 table
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