1,581 research outputs found

    Variables cinéticas de la batida relacionadas con el rendimiento del salto horizontal a pies juntos

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    El presente trabajo analiza las variables fuerza-tiempo (f-t), velocidad-tiempo (V-t) y potenciatiempo (P-t) que mås se relacionan con la distancia del salto horizontal (SH), y discute sobre la validez de este test como predictor de la fuerza explosiva de las extremidades inferiores. Participaron 144 estudiantes de educación física (96 hombres y 48 mujeres) que realizaron 3 saltos verticales (SV) sobre plataforma de contacto y 3 SH sobre plataforma de fuerzas. Se obtuvieron correlaciones significativas (p<0.05) entre SH y f-t, SH y P-t (relativas al peso corporal) y SH y V-t. Paralelamente, se obtuvieron diferencias significativas (p<0.05) en estas variables entre hombres y mujeres (6-36%). También se obtuvieron altas relaciones (p<0.001) entre SH y SV en hombres y mujeres (r= 0.68 y r= 0.69, respectivamente). En conclusión, el test de SH es vålido para evaluar la fuerza explosiva de las extremidades inferiores. Algunos aspectos metodológicos deben tenerse en cuenta para analizar y tratar las variables cinéticas del SH. Futuros trabajos deben seleccionar las variables cinéticas mås importantes para corregir la técnica del SH.The present work analyzes the force-time (f-t), speed-time (V-t) and power-time (P-t) variables related with the standing long jump distance (SLJ). Also, this work analyzes the validity of the SLJ in order to predict the lower extremities explosive force. 144 physical education students (96 men and 48 women) participated in this study. The students carried out 3 vertical jumps (VJ) on contact mat, and 3 SLJ on force plate. We have obtained significant correlations (p<0.05) between SLJ and f-t, SLJ and P-t (relative to body weight) and SLJ and V-t variables. Significant differences (p<0.05) between men and women were obtained in these variables (6-36 %). Also, relationships between SLJ and VJ (p< 0.001) were obtained in men and women (r= 0.68 and r= 0.69, respectively). In conclusion, the SLJ test is valid in order to evaluate the lower extremities explosive force. Some methodological aspects are important in order to analyze the SLJ kinetic variables. Future works should select the most important SLJ kinetic variables in order to correct the SLJ technique

    The names of southwestern european goats: Is iberian ibex the best common name for capra pyrenaica?

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    The names of southwestern European goats: is Iberian ibex the best common name for Capra pyrenaica? The common name designated to a species is important because it connects specialists with non–experts. The matter of the correct common name is relevant to the conservation and management of conspicuous or flag species. The English name "Spanish ibex" to designate Capra pyrenaica is extensive in the scientific literature, and some have defended its appropriateness. However, in our opinion, it is not the best term to designate this species. We propose that "Iberian wild goat" should be used. Herein, we review the etymology, history, taxonomy and public use of the names used to designate goats (domestic and wild) in southwestern Europe during the last two millennia. Used first by Pliny the Elder, the name "ibex" has been applied most often for the Alpine wild goat (C. ibex), and few authors applied this name to C. pyrenaica until the 20th century when some influential works extended its use in the scientific literature. Adult males of C. pyrenaica have lyre–shaped, and typically smooth horns that do not match the ibex morphotype, which has scimitar–shaped knotted horns. Although C. pyrenaica and C. ibex are probably phylogenetically close, their common names do not necessarily have to match. The rules of common names differ from those of scientific names. Cabra montĂ©s or cabra brava (wild goat) is the common name used by most authors in the Iberian peninsula. This name is deeply entrenched in the Iberian languages and has been used since the earliest references to the species in mediaeval times. We propose the adoption of "Iberian wild goat" for legal and scientific communication and when interacting with the media

    Anålisis en función del género de los jugadores sobre la percepción que tienen de su entrenador

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    [ES] El objetivo de este estudio fue analizar en funciĂłn del gĂ©nero de los jugadores la percepciĂłn que tienen de sus entrenadores respecto a su estilo de liderazgo autĂ©ntico, justicia percibida, competencia y atenciĂłn a las necesidades psicolĂłgicas bĂĄsicas . Participaron en el estudio 217 jugadores de fĂștbol y balonmano (147 hombres y 70 mujeres). Las deportistas de gĂ©nero femenino a diferencias de los de gĂ©nero masculino, mostraron niveles mĂĄs altos en las variables psicolĂłgicas seleccionadas. Este estudio deberĂ­a ser Ăștil a los entrenadores para reconocer cuales son las percepciones de sus deportistas, y de este modo, poder matizar su intervenciĂłn en funciĂłn del gĂ©nero del equipo al cual se entrene.[EN] This study aimed to analyze gender differences in athletes' perception of their coaches' authentic leadership style, perceived justice, competence, and attention to basic psychological needs. A total of 217 soccer and handball players (147 men and 70 women) participated. In contrast to male athletes, female athletes showed higher levels in the selected variables. This study should be helpful for coaches to identify their athletes' different perceptions depending on gender. Consequently, coaches may use a different approach depending on their team’s gender.S

    Perception of Coach According to the Role of Starter or Substitute in the Final Stage of the Season

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    [EN] This paper examines the athletes’ perception of their coaches according to the role of starter or substitute in the final phase of the season. The variables analyzed were: leadership style, perceived justice, competence, and support for basic psychological needs. A longitudinal study was developed, evaluating the participants at two different stages: the end of the season and seven weeks before. A total of 112 football and handball players participated in this study, 78 completing the questionnaire at the two waves. The final sample comprised 51 starters (80.39% males) and 27 substitutes (70.37% males) who evaluated their coaches’ leadership, competence, and support of the players’ psychological needs. The interaction moment of measurement (seven weeks before the end of the season vs. end of the season) * group (starters vs. substitutes) was statistically significant for the variables authentic leadership, perceived justice, and the basic psychological need of competence. Post hoc analyses revealed a significant decline in the perception of authentic leadership from coaches, perceived justice, and support of the psychological need of competence at the end of the season only in those in a starter position, with no change observed in the substitutes group. The findings show that the perceptions of coaches among starting players deteriorates significantly in the final phase of the season, while those among substitutes remain unaffected.S

    Well-Being and Throwing Speed of Women Handball Players Affected by Feedback

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    [EN] This research aims at studying the e ect of feedback on well-being (vitality, and positive and negative a ect), competence valuation, perceived competence, motivation, and performance (throwing speed and accuracy) in a throwing task. Thirty nine expert women handball players, with experience in international handball competitions, participated in this study. They were indiscriminately ascribed to one of three di erent experimental conditions measuring feedback: (positive, negative, and none). Significant di erences in well-being (positive a ect) and throwing speed were found among the three feedback groups. More concretely, higher levels of positive a ect and throwing speed were found in the negative feedback group in comparison with the other two groups (positive and no-feedback). These results have important implications for athletes’ well-being and performance, and for coaches’ training programs.S

    Full parameter scan of the Zee model: exploring Higgs lepton flavor violation

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    Published: April 21, 2017We study the general Zee model, which includes an extra Higgs scalar doublet and a new singly-charged scalar singlet. Neutrino masses are generated at one-loop level, and in order to describe leptonic mixing, both the Standard Model and the extra Higgs scalar doublets need to couple to leptons (in a type-III two-Higgs doublet model), which necessarily generates large lepton flavor violating signals, also in Higgs decays. Imposing all relevant phenomenological constraints and performing a full numerical scan of the parameter space, we find that both normal and inverted neutrino mass orderings can be fitted, although the latter is disfavored with respect to the former. In fact, inverted ordering can only be accommodated if ξ₂₃ turns out to be in the first octant. A branching ratio for h → Ï„ÎŒ of up to 10⁻ÂČ is allowed, but it could be as low as 10⁻⁶. In addition, if future expected sensitivities of τ → ÎŒÎł are achieved, normal ordering can be almost completely tested. Also, ÎŒe conversion is expected to probe large parts of the parameter space, excluding completely inverted ordering if no signal is observed. Furthermore, non-standard neutrino interactions are found to be smaller than 10⁻⁶, which is well below future experimental sensitivity. Finally, the results of our scan indicate that the masses of the additional scalars have to be below 2.5 TeV, and typically they are lower than that and therefore within the reach of the LHC and future colliders.Juan Herrero-GarcĂ­a, Tommy Ohlsson, Stella Riad and Jens WirĂ©

    The Impact of an Authentic Sports Leadership Program for Coach

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    [EN] Purpose: This paper studies the effects of authentic sports leadership training on coaches’ self-perception of their own authentic leadership, perceived justice, competence, overall self-efficacy, and collective efficacy. Additionally, players’ perceptions of their coaches with respect to their authentic leadership, perceived justice, competence, collective efficacy, satisfaction with the coach, and support for basic psychological needs were analyzed. Design: Twenty-five football and handball coaches were randomly assigned to two groups. Fifteen coaches made up the experimental group that carried out the training leadership program, while 10 coachesmade up the control group, carrying out no training whatsoever. A total of 248 football and handball players participated in this study; 136 were led by coaches who participated in the training program, and 112 by coaches who did not participate in the program. Results: The results of this study indicate that coaches’ self-perception is positively influenced after having received training in the variables of authentic leadership, perceived justice, competence, overall self-efficacy, and collective efficacy. Players whose coaches were part of the program perceive them as being more competent as coaches. Conclusions: The effects of an authentic sports leadership training program are effective for coaches and players alike.S

    Linear programming of a slate quarry

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    [Abstract] A new exploitation of roofing slate has several possibilities of marketing depending on the sizes of the pieces that it makes. Three sizes has been chosen among aH the possibilities in base of the conditions and the production of the rock in the quarry, the marketing limitation and the final price of the producto We've procces aH these data to obtain the optimun output, with the simplex algorithm. The objective function (week invoicing) and the restrictions of the problem are created in canonical and standard formo Optimun solution has been obtained among aH the basic and practical ones, using the graphic and the analytic method. Sorne conclusions come from the algorithm matrix about the outputs for each marketing option
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