Los pliegues cutáneos como predictores del porcentaje graso en futbolistas profesionales

El objetivo del presente estudio fue determinar los pliegues cutáneos que mejor predicen el porcentaje de grasa de futbolistas profesionales Peruanos a partir de tres ecuaciones. Para lo cual, se estudiaron 136 futbolistas profesionales evaluándose el peso corporal (kg), la estatura (m) y los pliegues cutáneos (mm) tricipital, subescapular, suprailiaco, abdominal, muslo y pantorrilla. Los resultados fueron analizados a través de la estadística descriptiva de la media aritmética (X) y desviación estándar (DE) y la estadística inferencial de regresión múltiple StepWise (p<0,001). Los resultados señalan que el % de grasa corporal hallado por las tres ecuaciones sugieren que los pliegues cutáneos tricipital, subescapular, suprailiaco y abdominal, explican mejor el % de grasa en relación a los pliegues del muslo y la pantorrilla media.The aim of this study was to determine the best predictors skinfold fat percentage Peruvian professional footballers from three equations. To this end, we studied 136 professional football players evaluated body weight (kg), height (m) and skinfold (mm) triceps, subscapular, suprailiac, abdominal, thigh and calf. The results were analyzed through descriptive statistics of the arithmetic mean (X) and standard deviation (SD) and inferential statistics multiple stepwise regression (p <0.001). The results indicate that the% body fat found by the three equations suggest that the triceps skinfold, subscapular, suprailiac and abdominal best explain the% fat in relation to the folds of the thigh and calf average.Peer Reviewe

A Minmax Principle, Index of the Critical Point, and Existence of Sign Changing Solutions to Elliptic Boundary Value Problems

In this article we apply the minmax principle we developed in [6] to obtain sign-changing solutions for superlinear and asymptotically linear Dirichlet problems. We prove that, when isolated, the local degree of any solution given by this minmax principle is +1. By combining the results of [6] with the degree-theoretic results of Castro and Cossio in [5], in the case where the nonlinearity is asymptotically linear, we provide sufficient conditions for: i) the existence of at least four solutions (one of which changes sign exactly once), ii) the existence of at least five solutions (two of which change sign), and iii) the existence of precisely two sign-changing solutions. For a superlinear problem in thin annuli we prove: i) the existence of a non-radial sign-changing solution when the annulus is sufficiently thin, and ii) the existence of arbitrarily many sign-changing non-radial solutions when, in addition, the annulus is two dimensional. The reader is referred to [7] where the existence of non-radial sign-changing solutions is established when the underlying region is a ball

On Multiple Solutions of a Nonlinear Dirichlet Problem

We prove that a semilinear elliptic boundary value problem has five solutions when the range of the derivative of the nonlinearity includes at least the first two eigenvalues. We also prove that if the region is a ball the semilinear elliptic problem has two solutions that change sign and are nonradial

Assessing the capability of in silico mutation protocols for predicting the finite temperature conformation of amino acids

Mutation protocols are a key tool in computational biophysics for modelling unknown side chain conformations. In particular, these protocols are used to generate the starting structures for molecular dynamics simulations. The accuracy of the initial side chain and backbone placement is crucial to obtain a stable and quickly converging simulation. In this work, we assessed the performance of several mutation protocols in predicting the most probable conformer observed in finite temperature molecular dynamics simulations for a set of protein-peptide crystals differing only by single-point mutations in the peptide sequence. Our results show that several programs which predict well the crystal conformations fail to predict the most probable finite temperature configuration. Methods relying on backbone-dependent rotamer libraries have, in general, a better performance, but even the best protocol fails in predicting approximately 30% of the mutations

Effects of supplementation of L-carnitine on the body composition of trained and sedentary rats

El objetivo del presente estudio es determinar el efecto de la suplementación de L-carnitina sobre la composición corporal de ratas entrenadas y sedentarias. Fueron seleccionadas de forma aleatoria 30 ratas machos Wistar, de 12 semanas de vida, cuyo peso osciló entre 350 a 380 gramos, constituyéndose cuatro grupos de animales: sedentario no suplementado (SNS), sedentario suplementado (SS), entrenado no suplementado (ENS) y entrenado suplementado (ES). El entrenamiento fue realizado con sesiones de carrera en la estera rodante, con duración de una hora y con suplementación oral crónica de L-Carnitina. Ambos protocolos con una duración de 4 semanas. La composición corporal fue evaluada a través de ecuaciones de predicción para determinar la masa libre de grasa (MLG) y masa de grasa (MG). Los resultados muestran que el entrenamiento físico disminuye los valores de la MLG y MG en el grupo ENS, y que la administración de la L-carnitina en forma conjunta con el entrenamiento físico revierte parcialmente la reducción de la MLG en el grupo ES. Finalmente se concluye que el ejercicio físico debe ser realizado juntamente con la suplementación de L-carnitina, permitiendo una disminución de la MG y mantener los niveles de MLG en ratas en proceso de crecimiento.The aim of this study is to determine the effect of L-carnitine supplementation on body composition of trained and sedentary rats. Were randomly selected 30 male Wistar rats of 12 weeks of age, whose weight ranged between 350 to 380 grams, four groups of animals: sedentary non-supplemented (SNS), sedentary supplemented (SS), trained not supplemented (ENS) trained and supplemented (ES). The training was done with sessions running on a treadmill, lasting an hour and chronic oral supplementation of L-carnitine. Both protocols with a duration of 4 weeks. Body composition was assessed by prediction equations to determine fat-free (FFM) and fat mass (FM). The results show that physical training decreases the values of FFM and FM in the ENS group, and that the administration of L-carnitine together with physical training partially reverses the reduction of MLG in ES. Finally concluded that physical exercise should be conducted jointly with the supplementation of L-carnitine, allowing a reduction in the MG and maintain levels in rats MLG growth process.Peer Reviewe

Correlation between explosive strength and speed in young players

El objetivo del presente estudio fue determinar las relaciones entre la fuerza explosiva y la velocidad V(20m) en futbolistas cadetes y juveniles. Para el estudio fueron evaluados 18 jugadores de la categoría infantil y 18 de la categoría juvenil, siendo un total de 36 futbolistas. Se evaluó el peso corporal (kg), estatura (cm) y el % de grasa corporal. Así como también los test de squat Jump SJ(cm), CounterMovement Jump CMJ(cm) y saltos verticales contínuos en 5 segundos CJ5s(cm). Los resultados muestran altas correlaciones entre SJ y CMJ (0,80), SJ y V(20m) ( 0,71) y CMJ y V(20m) (-0,61) en cadetes, así como en juveniles SJ y CMJ (0,89) y SJ y V(20m) (-0,62), respectivamente. Por lo tanto, se concluye que la fuerza explosiva se encuentra en estrecha relación con la velocidad (20m), tanto en jugadores de la categoría cadetes y juvenil.The aim of this study was to determine the relationship between the explosive power and speed V(20m) in children and youth players. For the study were evaluated 18 players in the cadet’s category and 18 in the youth category, for a total of 36 players. We assessed body weight (kg), height (cm) and% body fat, as well as the squat jump test, SJ (cm), countermovement jump CMJ (cm) and continuous vertical jumps in 5 seconds CJ5s (cm). The results show high correlations between SJ and CMJ (0.80), SJ and V(20m) ( 0.71) and CMJ and V (20m) (-0.61) in cadet’s and youth in SJ and CMJ (0.89) and SJ and V(20m) (-0.62), respectively. Therefore, we conclude that the explosive force is closely related to the speed (20m), both players of the cadets and youth category.Peer Reviewe

Propuesta de valores normativos para la clasificación de variables antropométricas en futbolistas profesionales

El objetivo del presente estudio es proponer una clasificación para identificar el % graso ideal a partir de variables antropométricas en futbolistas profesionales. Para lo cual, fueron utilizados 132 futbolistas profesionales a los que se les evaluó la Masa corporal (kg), Estatura (cm) y pliegues cutáneos (mm). Para el análisis estadístico se utilizó la estadística descriptiva de media aritmética (X), desviación estándar (DE), coeficiente de variación (CV) y para clasificar las variables antropométricas se utilizó los percentiles. Los resultados muestran que los valores ideales de % graso de los futbolistas oscila entre 9,0 a 12,6%, (p25 a p75), respectivamente. Finalmente, los parámetros adoptados como puntos de corte podrían ser utilizados como posibles indicadores para diagnosticar futbolistas con riesgo de lesión (pp75), a partir del % graso, masa corporal, e inclusive por la sumatoria de cuatro y seis pliegues cutáneos.The aim of this study is to propose a classification to identify the ideal % fat from anthropometric variables in professional soccer players. To which, using 132 players were professionals who were assessed for body mass (kg) Height (cm) and skinfolds (mm). For statistical analysis, descriptive statistics were used for arithmetic mean (X), standard deviation (SD), coefficient of variation (CV) and to classify the variables used anthropometric percentiles. The results show that the ideal values of % fat of the players ranges from 9.0 to 12.6% (p25 to p75), respectively. Finally, the parameters adopted as cutoff points could be used as indicators to diagnose potential players at risk of injury (p p75) from the % fat, body mass, and even by the sum of four and six skinfolds.Peer Reviewe

Participatory Plant Breeding: A New Challenge in the Generation and Appropriation of Potato Varieties by Farmers in Bolivia

Experiments on participatory plant breeding were carried out with the active participation of farmers from the Morochata Region in Bolivia