Formulation of exactly balanced solvers for blood flow in elastic vessels and their application to collapsed states

In this work, numerical solvers based on extensions of the Roe and HLL schemes are adapted to deal with test cases involving extreme collapsing conditions in elastic vessels. To achieve this goal, the system is transformed to provide a conservation–law form, allowing to define Rankine–Hugoniot conditions. The approximate solvers allow to describe the inner states of the solution. Therefore, source term fixes can be used to prevent unphysical values of vessel area and, at the same time, the eigenvalues of the system control stability. Numerical solvers of different order are tested using a wide variety of Riemann problems, including extreme vessel collapse and blockage. In all cases, the robustness of the approximate solvers presented here is checked using first and third order methods in time and space, using the WENO reconstruction scheme in combination with the TVDRK3 method

Influence of change of regulation on the goals achieved in futsal

Este artículo analiza la hipótesis de que los cambios introducidos en la normativa del fútbol sala modifican su lógica interna disminuyendo los goles totales y modificando su forma de ejecución. El objetivo de estudio es analizar los goles y manera de realizarlos en una temporada anterior y posterior al cambio de reglamentación para establecer cuantitativamente cómo el cambio de reglas del 2.006 afecta al juego. Se analizaron 3.126 goles en 442 partidos, 1.771 goles en 232 partidos en la temporada 2.002-2.003 y 1.355 goles en 210 partidos en la temporada 2.013-2.014. El método utilizado fue la metodología observacional, se utilizó el programa Lince vl.2.1. Los resultados muestran una reducción estadísticamente significativa en el número de goles de una temporada a otra. En la temporada 2.002-2.003 se lograron 1.927 goles con un promedio por equipo de 120,38 ± 28,58, y en la temporada 2.013-2.014 1.355 goles con un promedio de 90,40 ± 27,72This article analyses the hypothesis that the changes introduced in the regulation of futsal modify the inner logic of the game, what turns into a reduction of total goals and a significant variation in the form of execution. Therefore, it is set out as aim of study to analyze the goals and the way to achieve them in a previous season and in one subsequent to the change of regulation in order to establish quantitatively how the 2006 rules change has affected the game. Totally, 3126 goals were analyzed, scored in 442 matches, distributed in 1771 goals in 232 matches in season 2002-2003 and 1355 goals in 210 matches in season 2103-2014. The method used in this study was observational methodology. For the observational process, it has been used the observational software Lince vl.2.1. It has been carried out using the IBM SPSS 19.0.0 program. The results show a statistically significant reduction in the number of goals from one season to another. In season 2002-2003, 1927 goals were achieved with an average by team of 120.38±28.58, by 1355 goals in season 2013-2014 of 90.40±27.7

An efficient GPU implementation for a faster simulation of unsteady bed-load transport

Computational tools may help engineers in the assessment of sediment transport during the decision-making processes. The main requirements are that the numerical results have to be accurate and simulation models must be fast. The present work is based on the 2D shallow water equations in combination with the 2D Exner equation. The resulting numerical model accuracy was already discussed in previous work. Regarding the speed of the computation, the Exner equation slows down the already costly 2D shallow water model as the number of variables to solve is increased and the numerical stability is more restrictive. In order to reduce the computational effort required for simulating realistic scenarios, the authors have exploited the use of Graphics Processing Units in combination with non-trivial optimization procedures. The gain in computing cost obtained with the graphic hardware is compared against single-core (sequential) and multi-core (parallel) CPU implementations in two unsteady cases

Observational analysis of the goals the two seasons of the Spanish Professional Futsal League

Este estudio analiza las acciones ofensivas que terminan en gol a lo largo de las temporadas 2.012-2.013 y 2.013-2.014 en la liga de fútbol sala profesional español determinando las relaciones entre las variables anteriores que están involucrados en estas acciones. Los goles totales analizados han sido 2.449. El método utilizado fue una metodología observacional a través del programa Lince vl.2. Para el análisis estadístico se utilizó el programa IBM SPSS 19.0.0 para determinar la asociación o independencia entre las variables zona de tirosuperficie de contacto-tipo de tiro y tipo de acción-número de pases-jugadores involucrados. Los resultados muestran que la mayoría de los goles en fútbol sala se producen en jugadas rápidas de 1-2 pases con 1-2 jugadores participantes y que con defensas organizadas se requiere un mayor número de pases y la participación de 3 jugadores para encontrar líneas de pase antes de disparar con opciones de hacer golThis article analyse the offensive actions ending goal along the seasons 2.012- 2.013 and 2.013-2.014 of the Spanish professional futsal league and determine the relationships between the previous variables which are involved in these actions and influence goal. The total goals analyzed have been 2.449. The method used in this study was observational methodology. For the observational process, it has been used the observational software Lince vl.2.1. It has been carried out using the IBM SPSS 19.0.0 program to determine the association or independence between variables zone from which the shot is taken-contact surface-type of shot and type of play-number of passes-players involved. The results show with organized defenses, a bigger number of passes and the participation of 3 players touching the ball to find passing lanes before shooting with goal options are required and most of the goals in actual futsal occur in fast moves of 1-2 passes with 1 or 2 players involved in i

A Riemann coupled edge (RCE) 1D–2D finite volume inundation and solute transport model

A novel 1D–2D shallow water model based on the resolution of the Riemann problem at the coupled grid edges is presented in this work. Both the 1D and the 2D shallow water models are implemented in a finite volume framework using approximate Roe’s solvers that are able to deal correctly with wet/dry fronts. After an appropriate geometric link between the models, it is possible to define local Riemann problems at each coupled interface and estimate the contributions that update the cell solutions from the interfaces. The solute transport equation is also incorporated into the proposed procedure. The numerical results achieved by the 1D–2D coupled model are compared against a complete 2D model, which is considered the reference solution. The computational time is also examined

Physical activity levels during unstructured recess in Spanish primary and secondary schools

Introduction. The goals of this study were: a) to describe sedentary time and different physical activity (PA) intensities during school recess; b) to analyze sex and education level differences; c) to describe compliance with recommended guidelines for recess and; d) to determine the contribution of unstructured recess to PA guidelines. Material and Methods. Two subsamples from Spain participated: one of primary school students (114 girls, 8.77 +/- 1.74 years and 59 boys, 8.47 +/- 1.71 years), and one of secondary school students (100 girls, 12.16 +/- 0.49 years and 116 boys, 12.15 +/- 0.52 years). PA was quantified by accelerometers. Results and Discussion. Significant sex and education level effect was found over the combination of different percentages of PA intensities. All PA intensities except sedentary and light, showed higher values in primary education students. Boys reported higher values in MVPA both in primary and secondary. It was found a significant effect of sex and education level on the contribution of recess to PA guidelines. Conclusions. Interventions should be carried out to encourage PA during recess, especially for girls and secondary school students. Introducción. Los objetivos de este estudio fueron: a) describir el tiempo sedentario y diferentes niveles de intensidad de actividad física (AF) durante los recreos escolares; b) analizar las diferencias según el sexo y el nivel educativo; c) determinar el cumplimiento con las recomendaciones internacionales de práctica de AF para los periodos de recreo; d) definir la contribución de los recreos a las recomendaciones diarias de actividad física. Materiales y Métodos. Participaron dos muestras de alumnos: una de educación primaria (114 chicas, 8.77±1.74 años y 59 chicos, 8.47±1.71 años), y una de educación secundaria (100 chicas, 12.16±0.49 años y 116 chicos, 12.15±0.52 años). Se utilizaron acelerómetros para analizar los niveles de AF. Resultados y discusión. Los resultados mostraron un efecto significativo del género y el nivel educativo en las diferentes intensidades de actividad física. Todas las intensidades, excepto tiempo sedentario y actividad ligera, mostraron valores mayores en alumnos de educación primaria. Los chicos mostraron valores mayores en la actividad física moderada-vigorosa (AFMV). Se encontró también un efecto significativo del sexo y el nivel educativo en la contribución del recreo al cumplimiento de las recomendaciones de AF. Conclusiones. Deberían desarrollarse intervenciones para fomentar la AF durante los recreos, especialmente para chicas y alumnos de educación secundaria

Genética de poblaciones amazónicas: la historia evolutiva del jaguar, ocelote, delfín rosado, mono lanudo y piurí, reconstruida a partir de sus genes

The Amazon has more than the half of the world's biodiversity. Nevertheless, the major fraction of the Amazon species has unknown evolutionary histories. This is also certain for mammals and birds. Population genetics, employing molecular markers and theoretical mathematics models, can reconstruct these evolutionary histories and offer very powerful tools for the application of correct conservation politics. Herein, we show a comparative view of population genetics results obtained for Amazon populations of jaguar, ocelot, pink river dolphin, woolly monkey and wattled curassow and provide recommendation for their biological conservation. Each species showed its own specific evolutionary particularities, characteristics that were not shared by the other species. This finding should be taken into consideration for any effective biological conservation program. Key words: Amazon, Population genetics, Panthera, Leopardus, Inia, Lagothrix, Crax.El Amazonas contiene más de la mitad de la biodiversidad a escala mundial. Sin embargo, muchas de las especies que alberga, poseen historias evolutivas totalmente desconocidas. Esto incluye el caso de los mamíferos y de las aves. La genética de poblaciones, mediante el uso de marcadores moleculares, modelos y metodologías matemáticas, puede intentar reconstruir esa historia evolutiva y ofrecer herramientas efectivas para la aplicación de políticas correctas de conservación. Se muestra aquí un resumen de los estudios genético realizados en poblaciones amazónicas de jaguar, ocelote, delfín rosado, mono lanudo y piurí y se proponen algunas recomendaciones para su conservación biológica. En cada especie se observaron particularidades evolutivas propias no compartidas por las otras especies. Este hecho debe ser recogido por cualquier programa de conservación que pretenda ser efectivo. Palabras clave: Amazonas, Genética de poblaciones, Panthera, Leopardus, Inia, Lagothrix, Crax

Factors associated with compliance with physical activity recommendations among adolescents in Huesca.

BACKGROUND: Schools have been identified as environments of choice for physical activity promotion. This study examines factors associated with compliance with objectively assessed physical activity recommendations for early adolescents taking part in “Sigue la Huella”, a school-based intervention guided by a social ecological framework and Self-Determination Theory (Deci & Ryan, 2002). METHODS: A total of 200 students (108 boys) aged 12-13 years (M = 12.16; SD = ± 0.51), wore accelerometers during a 7-day period and completed a questionnaire. Participants were considered compliant to the recommendations if their moderate to vigorous physical activity, averaged over 7 days, was =60 minutes a day. RESULTS: 57.4% of boys and 9.9% of girls met recommendations. In a mixed logistic regression model, compliance was higher among boys and students attending private schools, and lower for obese students. Compliance was also associated with higher perceptions of physical competence, higher perceptions of autonomy in physical education, greater importance attached to physical education and less sedentary behavior. CONCLUSIONS: Assessed objectively, gender differences in compliance with physical activity recommendations were greater than expected. Self-Determination Theory emerged as a useful framework to identify motivational factors that can be addressed in school-based physical activity interventions and programs for early adolescents

HF spectrum activity prediction model based on HMM for cognitive radio applications

Although most of the research on Cognitive Radio is focused on communication bands above the HF upper limit (30 MHz), Cognitive Radio principles can also be applied to HF communications to make use of the extremely scarce spectrum more efficiently. In this work we consider legacy users as primary users since these users transmit without resorting to any smart procedure, and our stations using the HFDVL (HF Data+Voice Link) architecture as secondary users. Our goal is to enhance an efficient use of the HF band by detecting the presence of uncoordinated primary users and avoiding collisions with them while transmitting in different HF channels using our broad-band HF transceiver. A model of the primary user activity dynamics in the HF band is developed in this work to make short-term predictions of the sojourn time of a primary user in the band and avoid collisions. It is based on Hidden Markov Models (HMM) which are a powerful tool for modelling stochastic random processes and are trained with real measurements of the 14 MHz band. By using the proposed HMM based model, the prediction model achieves an average 10.3% prediction error rate with one minute-long channel knowledge but it can be reduced when this knowledge is extended: with the previous 8 min knowledge, an average 5.8% prediction error rate is achieved. These results suggest that the resulting activity model for the HF band could actually be used to predict primary users activity and included in a future HF cognitive radio based station