1,085 research outputs found

    Large Area Crop Inventory Experiment (LACIE). Intensive test site assessment report

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    There are no author-identified significant results in this report

    One-repetition-maximum measures or maximum bar-power output: which Is more related to sport performance?

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    Purpose: This study compared the associations between optimum power loads and 1-repetition maximum (1RM) values (assessed in half-squat [HS] and jump squat [JS] exercises) and multiple performance measures in elite athletes. Methods: Sixty-one elite athletes (fifteen Olympians) from four different sports (track and field [sprinters and jumpers], rugby sevens, bobsled, and soccer) performed squat and countermovement jumps, HS exercise (for assessing 1RM), HS and JS exercises (for assessing bar-power output), and sprint tests (60-m for sprinters and jumpers and 40-m for the other athletes). Pearson’s product moment correlation test was used to determine relationships between 1RM and bar-power outputs with vertical jumps and sprint times in both exercises. Results: Overall, both measurements were moderately to near perfectly related to speed performance (r values varying from -0.35 to -0.69 for correlations between 1RM and sprint times, and from -0.36 to -0.91 for correlations between bar-power outputs and sprint times; P< 0.05). However, on average, the magnitude of these correlations was stronger for power-related variables, and only the bar-power outputs were significantly related to vertical jump height. Conclusions: The bar-power outputs were more strongly associated with sprint-speed and power performance than the 1RM measures. Therefore, coaches and researchers can use the bar-power approach for athlete testing and monitoring. Due to the strong correlations presented, it is possible to infer that meaningful variations in bar-power production may also represent substantial changes in actual sport performance

    Optimum power loads for elite boxers: case study with the Brazilian national olympic team

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    The purpose of this case study was to examine the effects of a resistance-training program based on the optimum power loads (OPL) method on neuromuscular performance of Olympic boxing athletes during preparation for the Rio-2016 Olympic Games. Twelve elite amateur boxers from the Brazilian National Olympic Team participated in this study. Athletes were assessed at four time-points, over two consecutive competitive seasons. In the first season (considered as "control period"), the athletes executed a non-controlled strength-power training program for 10 weeks. In the second season (a seven-week experimental period), the elite boxers performed 14 power-oriented training sessions, comprising bench press (BP) and jump squat (JS) exercises at the OPL. Maximum bar-power output in BP and JS exercises was measured pre and post both training phases. Magnitude-based inferences were used to compare changes in pre and post training tests. Bar-power outputs increased meaningfully in both BP (+8%) and JS (+7%) exercises after the OPL training program. In contrast, after the control period, no worthwhile improvements were observed in the variables tested. Based on the findings of this study, highly trained boxers might benefit from the use of a training scheme based on OPL

    Entropy of Extremal Black Holes in Two Dimensions

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    Entropy for two dimensional extremal black holes is computed explicitly in a finite-space formulation of the black hole thermodynamics and is shown to be zero {\it locally}. Our results are in conformity with the recent one by Hawking et al in four dimensions.Comment: 11 page

    Regge Asymptotics of Scattering with Flavour Exchange in QCD

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    The contribution to the perturbative Regge asymptotics of the exchange of two reggeized fermions with opposite helicity is investigated. The methods of conformal symmetry known for the case of gluon exchange are extended to this case where double-logarithmic contributions dominate the asymptotics. The Regge trajectories at large momentum transfer are calculated.Comment: 18 pages LATEX, 3 figures using package FEYNMAN, N3-9

    High Energy Quark-Antiquark Elastic scattering with Mesonic Exchange

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    We studies the high energy elastic scattering of quark anti-quark with an exchange of a mesonic state in the tt channel with −t/Λ2≫1-t/\Lambda^{2} \gg 1. Both the normalization factor and the Regge trajectory can be calculated in PQCD in cases of fixed (non-running) and running coupling constant. The dependence of the Regge trajectory on the coupling constant is highly non-linear and the trajectory is of order of 0.20.2 in the interesting physical range.Comment: 29 page

    Infinite Lorentz boost along the M-theory circle and non-asymptotically flat solutions in supergravities

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    Certain non-asymptotically flat but supersymmetric classical solution of the type IIA supergravity can be interpreted as the infinitely-boosted version of the D-particle solution along the M-theory circle. By a chain of T-dual transformations, this analysis also applies to yield non-asymptotically flat solutions from the asymptotically flat and (non)-extremal solutions with intersecting D-strings and D five-branes of the type IIB supergravity compactified on a five-torus. Under S-duality, the non-asymptotically flat solutions in this context can in particular be used to describe the (1+1)-dimensional CGHS type black holes via spontaneous compactifications.Comment: 14 pages, Revte

    Flat World of Dilatonic Domain Walls

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    We study dilatonic domain walls specific to superstring theory. Along with the matter fields and metric the dilaton also changes its value in the wall background. We found supersymmetric (extreme) solutions which in general interpolate between isolated superstring vacua with non-equal value of the matter potential; they correspond to the static, planar domain walls with {\it flat} metric in the string (sigma model) frame. We point out similarities between the space-time of dilatonic walls and that of charged dilatonic black holes. We also comment on non-extreme solutions corresponding to expanding bubbles.Comment: 11 pgs (+2 figures available upon request), UPR-560-
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