Regulación emocional y recuperación física de los jóvenes deportistas en modalidades deportivas individual y colectiva

Indexación: Scopus.Due to the influence of positive and negative affects experienced during competition on sports performance, emotional regulation is one of the psychological variables that are more interesting to the sport psychology field. In this sense, this study analyzes how the use of reappraisal and suppression stimulates or hampers the physical recovery of young athletes. All of this taking into account the mediating role of self-efficacy and cognitive anxiety experienced during competition. Three hundred Chilean athletes with ages from 11 to 18 years old participated in this study (M = 15.15; SD = 2.38). Specifically, 139 of them practiced individual sports (boating, athletics, swimming, rhythmic gymnastics, and tennis) and 161 collective sports (basketball, volleyball, soccer, and rugby). Results show that the use of cognitive reappraisal as a dispositional strategy is associated with positive affect. In addition, cognitive reappraisal promotes self-efficacy in athletes during competition and stimulates their physical recovery. Emotional suppression produces the opposite effect, being associated to negative affect and impairing physical recovery by cognitive anxiety. Results are also discussed related to differences observed in the use of these two emotional regulation strategies in individual and collective sports, along with their practice implications for the training of young athletes in both modalities. © 2018 Revista Internacional de Ciencias del Deporte. All rights reserved.La influencia que los estados emocionales tienen en los deportistas cuando compiten ha hecho que la regulación emocional sea una de las variables psicológicas más interesantes a estudiar en los últimos años en el ámbito deportivo. En este sentido, este estudio analiza cómo los usos de las dos estrategias de regulación más usadas de forma disposicional favorecen o disminuyen la recuperación física de los deportistas jóvenes después de la competición. Todo ello teniendo en cuenta el papel mediador que la autoeficacia y la ansiedad cognitiva tienen en esa relación. Para este estudio se contó con la participación de 300 deportistas chilenos de 11 a 18 años (M = 15,15; DT = 2,38). En concreto, 139 practicaban deportes individuales (canotaje, atletismo, natación, gimnasia rítmica y tenis) y 161 deportes colectivos (básquetbol, voleibol, fútbol y rugby). Los resultados del estudio muestran que el uso de la reevaluación cognitiva como estrategia disposicional favorece la autoeficacia de los deportistas en competición y mejora la recuperación física. La supresión emocional, en cambio, se muestra como una estrategia desadaptativa que favorece la ansiedad cognitiva en competición y dificulta la recuperación física. Se discuten también los resultados respecto a las diferencias observadas en el uso de estas dos estrategias de regulación en deportes individuales y colectivos, y su implicación práctica en la preparación de los deportistas jóvenes en ambas modalidades deportivas.https://www.scopus.com/redirect/linking.uri?targetURL=https%3a%2f%2fdoi.org%2f10.5232%2fricyde2018.05301&locationID=1&categoryID=4&eid=2-s2.0-85049895193&issn=18853137&linkType=ViewAtPublisher&year=2018&origin=recordpage&dig=40092fbd145b817ecfc2d14738ebee92&recordRank

Self-trapping transition for nonlinear impurities embedded in a Cayley tree

The self-trapping transition due to a single and a dimer nonlinear impurity embedded in a Cayley tree is studied. In particular, the effect of a perfectly nonlinear Cayley tree is considered. A sharp self-trapping transition is observed in each case. It is also observed that the transition is much sharper compared to the case of one-dimensional lattices. For each system, the critical values of $\chi$ for the self-trapping transitions are found to obey a power-law behavior as a function of the connectivity $K$ of the Cayley tree.Comment: 6 pages, 7 fig

Control PD de Robots: Dinámica de Actuadores y Nueva Sintonía

ResumenEn el presente trabajo se estudia el control PD con compensación deseada de gravedad de robots rígidos. Se introduce un nuevo criterio, menos conservador, para seleccionar las ganancias proporcionales. Se demuestra estabilidad asintótica global cuando se toma en consideración durante el diseño la dinámica eléctrica de los motores de CD con escobillas usados como actuadores. Este resultado no requiere que la dinámica eléctrica de los actuadores sea rápida comparada con la dinámica de la parte mecánica. Se presenta un estudio formal de la técnica de control conocida como control de par la cual es ampliamente utilizada en la práctica industrial

Desarrollo y validación del cuestionario de autoconfianza en competición CACD para deportes individuales y colectivos

El objetivo de este estudio fue construir y validar un cuestionario de autoconfianza en competición deportiva en Chile. Este fue administrado a una muestra de 307 deportistas de deportes individuales y colectivos en competición regular con edades que oscilaban entre los 11 y 35 años. Los análisis factoriales exploratorio y confirmatorio apoyan una estructuraunidimensional de autoconfianza en situación deportiva. La consistencia interna es adecuada y además las puntuaciones muestran correlaciones positivas y significativas con la dimensión de autoconfianza del CSAI II y con una medida de autoeficacia general de Schwarzer y Baessler (1996) que al utilizarse con deportistas también mostró valores adecuados

Micropillar compression of LiF [111] single crystals: effect of size, ion irradiation and misorientation

The mechanical response under compression of LiF single crystal micropillars oriented in the [111] direction was studied. Micropillars of different diameter (in the range 1–5 lm) were obtained by etching the matrix in directionally-solidified NaCl–LiF and KCl–LiF eutectic compounds. Selected micropillars were exposed to high-energy Ga+ ions to ascertain the effect of ion irradiation on the mechanical response. Ion irradiation led to an increase of approximately 30% in the yield strength and the maximum compressive strength but no effect of the micropillar diameter on flow stress was found in either the as-grown or the ion irradiated pillars. The dominant deformation micromechanisms were analyzed by means of crystal plasticity finite element simulations of the compression test, which explained the strong effect of micropillar misorientation on the mechanical response. Finally, the lack of size effect on the flow stress was discussed to the light of previous studies in LiF and other materials which show high lattice resistance to dislocation motion

Superplastic deformation of directionally solidified nanofibrillar Al2O3-Y3Al5O12-Zr O2 eutectics

Nanofibrillar Al2O3–Y3Al5O12–ZrO2 eutectic rods were manufactured by directional solidification from the melt at high growth rates in an inert atmosphere using the laser-heated floating zone method. Under conditions of cooperative growth, the ternary eutectic presented a homogeneous microstructure, formed by bundles of single-crystal c-oriented Al2O3 and Y3Al5O12 (YAG) whiskers of ˜100 nm in width with smaller Y2O3-doped ZrO2 (YSZ) whiskers between them. Owing to the anisotropic fibrillar microstructure, Al2O3–YAG–YSZ ternary eutectics present high strength and toughness at ambient temperature while they exhibit superplastic behavior at 1600 K and above. Careful examination of the deformed samples by transmission electron microscopy did not show any evidence of dislocation activity and superplastic deformation was attributed to mass-transport by diffusion within the nanometric domains. This combination of high strength and toughness at ambient temperature together with the ability to support large deformations without failure above 1600 K is unique and shows a large potential to develop new structural materials for very high temperature structural applications

Vacuum fluctuations and topological Casimir effect in Friedmann-Robertson-Walker cosmologies with compact dimensions

We investigate the Wightman function, the vacuum expectation values of the field squared and the energy-momentum tensor for a massless scalar field with general curvature coupling parameter in spatially flat Friedmann-Robertson-Walker universes with an arbitrary number of toroidally compactified dimensions. The topological parts in the expectation values are explicitly extracted and in this way the renormalization is reduced to that for the model with trivial topology. In the limit when the comoving lengths of the compact dimensions are very short compared to the Hubble length, the topological parts coincide with those for a conformal coupling and they are related to the corresponding quantities in the flat spacetime by standard conformal transformation. In the opposite limit of large comoving lengths of the compact dimensions, in dependence of the curvature coupling parameter, two regimes are realized with monotonic or oscillatory behavior of the vacuum expectation values. In the monotonic regime and for nonconformally and nonminimally coupled fields the vacuum stresses are isotropic and the equation of state for the topological parts in the energy density and pressures is of barotropic type. In the oscillatory regime, the amplitude of the oscillations for the topological part in the expectation value of the field squared can be either decreasing or increasing with time, whereas for the energy-momentum tensor the oscillations are damping.Comment: 20 pages, 2 figure

Measurement of the p-pbar -> Wgamma + X cross section at sqrt(s) = 1.96 TeV and WWgamma anomalous coupling limits

The WWgamma triple gauge boson coupling parameters are studied using p-pbar -> l nu gamma + X (l = e,mu) events at sqrt(s) = 1.96 TeV. The data were collected with the DO detector from an integrated luminosity of 162 pb^{-1} delivered by the Fermilab Tevatron Collider. The cross section times branching fraction for p-pbar -> W(gamma) + X -> l nu gamma + X with E_T^{gamma} > 8 GeV and Delta R_{l gamma} > 0.7 is 14.8 +/- 1.6 (stat) +/- 1.0 (syst) +/- 1.0 (lum) pb. The one-dimensional 95% confidence level limits on anomalous couplings are -0.88 < Delta kappa_{gamma} < 0.96 and -0.20 < lambda_{gamma} < 0.20.Comment: Submitted to Phys. Rev. D Rapid Communication

Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt{s} = 1.96 TeV using Kinematic Characteristics of Lepton + Jets Events

We present a measurement of the top quark pair ttbar production cross section in ppbar collisions at a center-of-mass energy of 1.96 TeV using 230 pb**{-1} of data collected by the DO detector at the Fermilab Tevatron Collider. We select events with one charged lepton (electron or muon), large missing transverse energy, and at least four jets, and extract the ttbar content of the sample based on the kinematic characteristics of the events. For a top quark mass of 175 GeV, we measure sigma(ttbar) = 6.7 {+1.4-1.3} (stat) {+1.6- 1.1} (syst) +/-0.4 (lumi) pb, in good agreement with the standard model prediction.Comment: submitted to Phys.Rev.Let

Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Lepton + Jets Events with Lifetime b-tagging

We present a measurement of the top quark pair ($t\bar{t}$) production cross section ($\sigma_{t\bar{t}}$) in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV using 230 pb$^{-1}$ of data collected by the D0 experiment at the Fermilab Tevatron Collider. We select events with one charged lepton (electron or muon), missing transverse energy, and jets in the final state. We employ lifetime-based b-jet identification techniques to further enhance the $t\bar{t}$ purity of the selected sample. For a top quark mass of 175 GeV, we measure $\sigma_{t\bar{t}}=8.6^{+1.6}_{-1.5}(stat.+syst.)\pm 0.6(lumi.)$ pb, in agreement with the standard model expectation.Comment: 7 pages, 2 figures, 3 tables Submitted to Phys.Rev.Let