Implementation of a resistance training on young football players

El objetivo de este estudio, es comprobar el efecto de un programa de 20 sesiones de entrenamiento específico de fuerza en futbolistas jóvenes Participaron 38 sujetos en el estudio, divididos en un grupo experimental (GE) y un grupo control (GC). Al GE se le administró un entrenamiento de fútbol y un trabajo específico de fuerza; mientras el GC sólo efectuó práctica de fútbol. Ambos fueron evaluados al inicio y al final del programa, con el objetivo de conocer su fuerza dinámica máxima en los flexores y extensores de la rodilla; su masa muscular en las extremidades inferiores; el porcentaje de grasa; y, por último, la velocidad en las pruebas de 10 y 20 metros. Únicamente el GE mejora de forma muy significativa la fuerza dinámica máxima (p<0,01). No se encuentran diferencias en la masa muscular, ni en la velocidad. El GE y el GC incrementan el porcentaje de grasa corporalThe aim of this study is to check the effect of a specific training strength program on young footballers. 38 players took place in the study; they were divided into an experimental group (EG) and a control group (CG). The EG added a specific strength work to their football workout, whereas the CG just practised football. Both of them were assessed at the beginning and at the end of the program to know their maximum dynamic strength in their flexor and extensor muscles of their knees; their muscle mass in their lower extremities; their body mass and fat percentage; and their speed in the 10 and 20 metres trials. Just the EG improves remarkably their maximum dynamic strength … No differences in their muscle mass or in their movement strength are found. The EG and the CG increase their MBRate and their body fa

Influencia de la carga de sólido en la producción de D-xilosa mediante hidrólisis del hueso de aceituna con ácido sulfúrico diluido

The selective hydrolysis of hemicellulose from olive stones was attempted in order to achieve a maximum D-xylose yield. For this aim, batch hydrolysis was conducted under different operating conditions of temperature, acid concentration and solid loading. Firstly, distilled water, sulphuric acid and nitric acid were assessed as hydrolytic agents at different temperatures (200, 205, 210 and 220 °C) and at a fixed acid concentration (0.025 M). Sulphuric acid and 200 °C were selected for the subsequent dilute acid hydrolysis optimization based on the obtained D-xylose yields. The combined influence of solid loading (from 29.3 to 170.7 g olive stones into 300 mL acid solution) and sulphuric acid concentration (0.006–0.034 M) on the release of D-xylose was then estimated by response surface methodology. According to a statistical analysis, both parameters had significant interaction effects on D-xylose production. The results illustrated that the higher the solid loading, the higher the required acid concentration. The decrease in the solid/liquid ratio in the reactor had a positive effect on D-xylose extraction and on the amount of acid used. The optimum solid loading and sulphuric acid concentration were determined to be 50 g (solid/liquid ratio 1/6) and 0.016 M, respectively. Under these conditions, the predicted D-xylose yield (expressed as g of sugar per 100 g of dry matter fed) was 20.4 (87.2% of maximum attainable).Se ha desarrollado una hidrólisis selectiva de la fracción hemicelulósica del hueso de aceituna con el fin de obtener el máximo rendimiento de D-xilosa. Para ello las hidrólisis se llevaron a cabo en un reactor discontinuo a distintas condiciones de temperatura, concentración de ácido y carga de sólidos. En primer lugar se evaluó la capacidad hidrolítica del agua destilada y de los ácidos nítrico y sulfúrico a distintas temperaturas (200, 205, 210 y 220°C) manteniendo fija la concentración de ácido (0,025 M). A partir de los rendimientos en D-xilosa obtenidos se seleccionó el ácido sulfúrico y una temperatura de 200 °C para la posterior optimización del proceso. La influencia conjunta de la carga de sólidos (desde 29,3 a 170,7 g de hueso de aceituna en 300 mL de disolución ácida) y de la concentración de ácido sulfúrico (0,006–0,034 M) sobre los rendimientos de D-xilosa fue determinada mediante metodología de superficie de respuesta. Según el análisis estadístico ambos parámetros tuvieron un efecto interactivo significativo en la producción de D-xilosa. Los resultados mostraron que se requiere mayor concentración de ácido a mayor carga de sólidos. La disminución de la relación sólido/líquido en el reactor tuvo un efecto positivo en la extracción de D-xilosa y en la cantidad de ácido utilizado. Las condiciones óptimas fueron 50 g de sólidos (relación sólido/ líquido 1/6) y concentración de ácido sulfúrico 0,016 M. Bajo estas condiciones, el rendimiento de D-xilosa predicho, expresado en g de azúcar por cada 100 g de huesos de aceituna, fue 20,4 (87,2% del máximo teórico)

Anderson localization in a periodic photonic lattice with a disordered boundary

We investigate experimentally the light evolution inside a two-dimensional finite periodic array of weakly- coupled optical waveguides with a disordered boundary. For a completely localized initial condition away from the surface, we find that the disordered boundary induces an asymptotic localization in the bulk, centered around the initial position of the input beam.Comment: 3 pages, 4 figure

Hygienization and control of Diplodia seriata fungus in vine pruning waste composting and its seasonal variability in open and closed systems

After the ban on sodium arsenite, waste management alternatives to the prevalent burning method, such as the hygienization and biodegradation in solid phase by composting, are required for the pruned material from grapevines affected by various fungi. In this work the dynamics of a fungus associated with vine decay (Diplodia seriata) during the composting process of a mixture of laying hen manure and vine pruning waste (2:1 w/w) have been investigated in an open pile and a discontinuous closed biodigester. Through the optimization of the various physical–chemical parameters, hygienization of the infected waste materials was attained, yielding class-A organo-mineral fertilizers. Nevertheless, important differences in the efficiency of each system were observed: whereas in the open pile it took 10 days to control D. seriata and 35 additional composting days to achieve full inactivation, in the discontinuous biodigester the fungus was entirely inactivated within the first 3–7 days. Finally, the impact of seasonal variability was assessed and summer temperatures shown to have greater significance in the open pile

Distribución de elementos menores y trazas en casiteritas de distintos tipos de yacimientos españoles

[Resumen] En este trabajo se presenta, por primera vez, la composición química de muestras de casi teri tas pertenecientes a distintos tipos de yacimientos españoles, local izados a lo largo del Macizo Hespérico. Se establecen correlaciones entre los caracteres geoquímicos y genéticos, así como, entre el hábito y el color con la tipología del yacimiento: Bipirámides de tonalidades oscuras, junto con una escasa ó nula maclación, son típicas de los depósitos de diseminación y pegmatíticos. Prismas apuntados en pirámides, con una extensa gama de color y abundante maclación I son característicos de yacimientos filonianos.[Abstract] This study presents the chemical composi tion of cassi teri tes samples from different kinds of Spanish deposi ts, for first time. The correlations between geochemical and genetic characteristics are presented, and also, between habi t and colour wi th the type of deposit: Bipyramids of dark tonali ties wi th a li ttle or null twining are characteristic of dissemination and pegmati tic deposits. Pointed prims in pyramid wi th a wide range of colours and abundant twining are characteristic of lode deposit

Effect of small-sided games on football players

El objetivo ha sido analizar cómo influyen los juegos reducidos o SSGs sobre la condición física, técnica y los cambios de dirección (CODA) en jugadoras alevines de fútbol femenino. Participan 12 jugadoras de fútbol femenino. Realizaron 14 sesiones de entrenamiento basado en juegos reducidos de fútbol. La muestra presenta valores normales en la prueba de Saphiro-Wilk, además, en la prueba de t de Student muestra que existen diferencias estadísticamente muy significativas (p ≤0,00) en todas las variables físicas analizadas, menos en el caso de la fuerza explosiva. En las variables de técnica nos muestra que existen diferencias significativas en todas las variables analizadas (p ≤0,00). Por último existen correlaciones positivas y estadísticamente significativas entre las distintas variables analizadas. De esta forma podemos considerar los juegos reducidos son un método adecuado y muy ventajoso para el entrenamiento en las etapas iniciales o de formación en jugadoras de fútbolThe objective has been to analyze how small-sided games or SSGs affect physical, technical and changes of direction (CODA) in U12 female soccer players. 12 female soccer players participate. They conducted 14 training sessions based on reduced soccer games. The sample has normal values in the Saphiro-Wilk test, and in the Student's t test it shows that there are statistically very significant differences (p ≤0,00) in all the analyzed physical variables, less in the case of the explosive force. In the technique variables we show that there are significant differences in all variables analyzed (p ≤0,00). Finally, there are positive and statistically significant correlations between the different variables analyzed. In this way we can consider reduced games are a suitable and very advantageous method for training in the initial stages or training in soccer player

Singular sources in the Demianski-Newman spacetimes

The analysis of singular regions in the NUT solutions carried out in the recent paper (Manko and Ruiz, 2005 Class. Quantum Grav. 22, p.3555) is now extended to the Demianski-Newman vacuum and electrovacuum spacetimes. We show that the effect which produces the NUT parameter in a more general situation remains essentially the same as in the purely NUT solutions: it introduces the semi-infinite singularities of infinite angular momenta and positive or negative masses depending on the interrelations between the parameters; the presence of the electromagnetic field additionally endows the singularities with electric and magnetic charges. The exact formulae describing the mass, charges and angular momentum distributions in the Demianski-Newman solutions are obtained and concise general expressions P_n=(m+i\nu)(ia)^n, Q_n=(q+ib)(ia)^n for the entire set of the respective Beig-Simon multipole moments are derived. These moments correspond to a unique choice of the integration constant in the expression of the metric function \omega which is different from the original choice made by Demianski and Newman.Comment: 22 pages, 5 figures; submitted to Classical and Quantum Gravit

Uncertainty quantification and predictability of wind speed over the Iberian Peninsula

During recent decades, the use of probabilistic forecasting methods has increased markedly. However, these predictions still need improvement in uncertainty quantification and predictability analysis. For this reason, the main aim of this paper is to develop tools for quantifying uncertainty and predictability of wind speed over the Iberian Peninsula. To achieve this goal, several spread indexes extracted from an ensemble prediction system are defined in this paper. Subsequently, these indexes were evaluated with the aim of selecting the most appropriate for the characterization of uncertainty associated to the forecasting. Selection is based on comparison of the average magnitude of ensemble spread (ES) and mean absolute percentage error (MAPE). MAPE is estimated by comparing the ensemble mean with wind speed values from different databases. Later, correlation between MAPE and ES was evaluated. Furthermore, probability distribution functions (PDFs) of spread indexes are analyzed to select the index with greater similarity to MAPE PDFs. Then, the spread index selected as optimal is used to carry out a spatiotemporal analysis of model uncertainty in wind forecasting. The results indicate that mountainous regions and the Mediterranean coast are characterized by strong uncertainty, and the spread increases more rapidly in areas affected by strong winds. Finally, a predictability index is proposed for obtaining a tool capable of providing information on whether the predictability is higher or lower than average. The applications developed may be useful in the forecasting of wind potential several days in advance, with substantial importance for estimating wind energy production

Integral field spectroscopy of M1-67. A Wolf-Rayet nebula with LBVN appearance

This work aims to disentangle the morphological, kinematic, and chemical components of the nebula M1-67 to shed light on its process of formation around the central Wolf-Rayet (WR) star WR124. We have carried out integral field spectroscopy observations over two regions of M1-67, covering most of the nebula in the optical range. Maps of electron density, line ratios, and radial velocity were created to perform a detailed analysis of the two-dimensional structure. We studied the physical and chemical properties by means of integrated spectra selected over the whole nebula. Photoionization models were performed to confirm the empirical chemical results theoretically. In addition, we analysed infrared spectroscopic data and the MIPS 24micron image of M1-67 from Spitzer. We find that the ionized gas of M1-67 is condensed in knots aligned in a preferred axis along the NE-SW direction, like a bipolar structure. Both electron density and radial velocity decrease in this direction when moving away from the central star. From the derived electron temperature, Te~8200 K, we have estimated chemical abundances, obtaining that nitrogen appears strongly enriched and oxygen depleted. From the last two results, we infer that this bipolarity is the consequence of an ejection of an evolved stage of WR124 with material processed in the CNO cycle. The infrared study has revealed that the bipolar axis is composed of ionized gas with a low ionization degree that is well mixed with warm dust and of a spherical bubble surrounding the ejection at 24micron. Taking the evolution of a 60 Mo star and the temporal scale of the bipolar ejection into account, we propose that the observed gas was ejected during an eruption in the luminous blue variable. The star has entered the WR phase recently without apparent signs of interaction between WR-winds and interstellar material.Comment: Accepted for publication in section 6 of Astronomy and Astrophysics. The official date of acceptance is 15/03/2013. 17 pages, 14 figures and 8 table