Current methods of soccer match analysis

Ha sido realizada una revisión de 86 artículos, con el objetivo de analizar a través de los estudios más recientes los beneficios y limitaciones de los nuevos sistemas para el análisis del futbolista durante el partido, debido a que las mayores exigencias en el rendimiento del fútbol moderno está obligando a replantearse cuáles son sus demandas físicas, así como los modelos de planificación y los métodos de entrenamiento tradicionales. Los resultados muestran que el vídeo análisis asistido por ordenador para la codificación de los patrones de movimiento y la tecnología GPS se presentan como herramientas de gran utilidad para conocer mejor la carga física del jugador, mientras que el diseño observacional facilita la evaluación del comportamiento técnico-táctico del futbolista y el equipo. Como conclusión podemos decir que hemos observado sin embargo una metodología diferente entre las opciones comerciales disponibles y una tecnología ubicada todavía en una etapa inicial de desarrolloA review of 86 references has been made, in order to analyze through the most recent studies the benefits and limitations of the new systems for the analysis of soccer player during the match, due to the fact that the greater performance requirements of modern soccer is forcing to review his physical demands, as well as planning models and traditional training methods. The results show that the computer-aided video analysis for coding movement patterns and the GPS technology are presented as very useful tools for a better understanding of the players physical load, whereas the observational design facilitates assessment of the technical-tactical behavior of the soccer player and the team. In conclusion we can say that we have however observed a different methodology among the available commercial options and a technology still placed at an initial stage of development

3x2 Achievement Goals, Friendship and Affectivity in Physical Education: Age-Gender Differences

Se persiguen tres objetivos: (a) analizar las diferencias relativas a la edad y sexo en las metas de logro 3x2, metas de amistad, y afectividad en Educación Física, (b) estudiar las relaciones entre esas variables, y (c) explorar el valor predictivo de las metas de logro 3x2 y amistad sobre la afectividad. La muestra estuvo formada por 1610 alumnos (855 varones y 755 mujeres) de 10 a 17 años. Se realizaron MANOVAS, análisis univariados (Scheffé), y regresiones lineales. Los resultados mostraron un descenso significativo de las metas de logro (excepto aproximación-otro), metas de amistad y afecto positivo debido al desarrollo. Los varones puntuaron más alto las metas de aproximación-tarea, aproximación-otro, y evitación-otro. Las metas de aproximación-tarea y aproximación-amistad fueron los principales predictores positivos del afecto positivo. La franja de 13 a 14 años muestra una gran sensibilidad a los tres estándares de competencia de logro, competencia social e inestabilidad afectivaThe objectives of the study are three: (a) to analyze the differences related to age and sex in the 3x2 achievement goals, the friendship goals, and the affectivity in Physical Education, (b) to study the relationships between these variables, and c) to explore the predictive value of the 3x2 achievement goals and friendship on affectivity. The sample consisted of 1610 students (855 males and 755 females), aged between 10 and 17 years. MANOVAS, univariate analyzes (Scheffé), and linear regressions were performed. The results showed a significant decrease in achievement goals (except other-approach), friendship goals, and positive affect due to development. Males scored higher on task-approach, other-approach, and other-avoidance goals than women. Task-approach and friendship-approach were the main positive predictors of positive affect. The range of 13 to 14 years shows a great sensitivity to the three competences of achievement, social competence, and affective instabilit

Formation of asymmetric arms in barred galaxies

ABSTRACTWe establish a dynamical mechanism to explain the origin of the asymmetry between the arms observed in some barred disc galaxies, where one of the two arms emanating from the bar ends is very well defined, while the second one displays a ragged structure, extending between its ridge and the bar. To this purpose, we study the invariant manifolds associated with the Lyapunov periodic orbits around the unstable equilibrium points at the ends of the bar. Matter from the galaxy centre is transported along these manifolds to the periphery, forming this way the spiral arms that emanate from the bar ends. If the mass distribution in the galaxy centre is not homogeneous, because of an asymmetric bar with one side stronger than the other, or because of a non-centred bulge, the dynamics about the two unstable Lagrange points at the ends of the bar will not be symmetric as well. One of their invariant manifolds becomes more extended than the other, enclosing a smaller section and the escaping orbits on it are fewer and dispersed in a wider region. The result is a weaker arm and more ragged than the one at the other end of the bar

Mujeres que son pareja de un varón infectado por el VIH: descripción de sus características y valoración del riesgo

ObjetivoDescribir las situaciones de riesgo y la prevalencia del virus de la inmunodeficiencia humana (VIH) en mujeres con pareja heterosexual infectada por el VIH.DiseñoEstudio descriptivo y transversal.EmplazamientoCentro ambulatorio de diagnóstico del VIH de Madrid.PacientesSe incluyó en el estudio a 229 mujeres atendidas por primera vez entre 1993 y 2002 por tener una pareja heterosexual estable diagnosticada de infección por el VIH, sin otra exposición de riesgo.Mediciones principalesInformación sociodemográfica, historial reproductivo, conducta sexual, datos clínicos y analíticos de ambos miembros de la pareja.ResultadosEl 66% de las parejas mantenían relaciones sexuales desde hacía más de un año. Las mujeres tenían menor edad media (29,6 años) que los varones. El 29% de las mujeres tenían hijos y el 5,2% estaban embarazadas. Entre los varones, el 82% se había inyectado drogas, pero sólo el 13% mantenía esta práctica. El 73% estaba diagnosticado de infección por el VIH desde hacía más de 6 meses, el 16% presentaba criterios de sida y el 35% recibía tratamiento antirretroviral. El 60% de los varones que conocían previamente su infección habían evitado sistemáticamente los coitos sin preservativo, frente al 33% de los que no se sabían infectados (p < 0,001). El 19% había tenido accidentes en el uso del preservativo. La seroprevalencia del VIH en las mujeres fue del 6,1% (intervalo de confianza del 95%, 3,5-10,3%).ConclusionesLa atención a las personas con VIH debe incluir la asistencia a la pareja sexual, ofreciendo información, apoyo psicológico, consejo preventivo y reproductivo, además del diagnóstico del VIH y de otras infecciones de transmisión sexual.ObjectiveTo describe the situations of risk and the prevalence of HIV in women with a heterosexual partner infected by HIV.DesignCross-sectional descriptive study.SettingOut-patient HIV diagnosis centre in Madrid.Patients229 women seen for the first time between 1993 and 2002 because they had a stable heterosexual partner diagnosed with HIV, and who were exposed to no other risk.Main measurementsSocial and personal details, reproduction history, sexual conduct, clinical, and analytic data of both partners.Results66% of couples had maintained sexual relations for over a year.Women were on average younger (29.6 years old) than the men. 29% of the women had children and 5.2% were pregnant. 82% of men had injected drugs, but only 13% still did. 73% had been diagnosed with HIV for over 6 months, 16% had AIDS criteria, and 35% were taking retroviral treatment. 60% of the men who knew of their infection had systematically avoided sex without condoms, against 33% of those who did not know they were infected (P<.001). 19% had had accidents in use of the condom.HIV seroprevalence in the women was 6.1% (95% CI, 3.5%-10.3%).ConclusionsHealth care of people with HIV must include care of their sexual partner, involving information, psychological support, preventive and reproductive advice, as well as diagnosis of HIV or other sexually transmitted diseases

Theoretical and experimental evidence of level repulsion states and evanescent modes in sonic crystal stubbed waveguides

The complex band structures calculated using the Extended Plane Wave Expansion (EPWE) reveal the presence of evanescent modes in periodic systems, never predicted by the classical \omega(\vec{k}) methods, providing novel interpretations of several phenomena as well as a complete picture of the system. In this work we theoretically and experimentally observe that in the ranges of frequencies where a deaf band is traditionally predicted, an evanescent mode with the excitable symmetry appears changing drastically the interpretation of the transmission properties. On the other hand, the simplicity of the sonic crystals in which only the longitudinal polarization can be excited, is used to interpret, without loss of generality, the level repulsion between symmetric and antisymmetric bands in sonic crystals as the presence of an evanescent mode connecting both repelled bands. These evanescent modes, obtained using EPWE, explain both the attenuation produced in this range of frequencies and the transfer of symmetry from one band to the other in good agreement with both experimental results and multiple scattering predictions. Thus, the evanescent properties of the periodic system have been revealed necessary for the design of new acoustic and electromagnetic applications based on periodicity

Tunable Plasmon Molecules in Overlapping Nanovoids

Coupled and shape-tailored metallic nanoparticles are known to exhibit hybridized plasmon resonances. This Letter discuss the optical properties of a complementary system formed by overlapped nanovoid dimers buried in gold and filled with silica. This is an alternative route for plasmon engineering that benefits from vanishing radiation losses. Our analysis demonstrates the possibility of designing artificial plasmon molecules on the basis of void plasmon hybridization, which allows fine mode tuning by varying the overlap between voids. The proposed structures could find application to both signal processing through buried optical elements and tunable-plasmon biosensing.Comment: 4 pages, 4 figure

Plasmon tunability in metallodielectric metamaterials

The dielectric properties of metamaterials consisting of periodically arranged metallic nanoparticles of spherical shape are calculated by rigorously solving Maxwell's equations. Effective dielectric functions are obtained by comparing the reflectivity of planar surfaces limiting these materials with Fresnel's formulas for equivalent homogeneous media, showing mixing and splitting of individual-particle modes due to inter-particle interaction. Detailed results for simple cubic and fcc crystals of aluminum spheres in vacuum, silver spheres in vacuum, and silver spheres in a silicon matrix are presented. The filling fraction of the metal f is shown to determine the position of the plasmon modes of these metamaterials. Significant deviations are observed with respect to Maxwell-Garnett effective medium theory for large f, and multiple plasmons are predicted to exist in contrast to Maxwell-Garnett theory.Comment: 6 pages, 4 figure

Source identification for mobile devices, based on wavelet transforms combined with sensor imperfections

One of the most relevant applications of digital image forensics is to accurately identify the device used for taking a given set of images, a problem called source identification. This paper studies recent developments in the field and proposes the mixture of two techniques (Sensor Imperfections and Wavelet Transforms) to get better source identification of images generated with mobile devices. Our results show that Sensor Imperfections and Wavelet Transforms can jointly serve as good forensic features to help trace the source camera of images produced by mobile phones. Furthermore, the model proposed here can also determine with high precision both the brand and model of the device

Variability of early autumn planktonic assemblages in the strait of Gibraltar: a regionalization analysis

The Strait of Gibraltar (SG) is the only connection of the Mediterranean Sea with the global circulation. The SG is an outstanding marine region to explore physical-biological coupling of pelagic communities due to its hydrodynamic complexity, including strong tidal forcing and marked spatial gradients and fronts. The authors have unravelled the role of the fortnightly tidal scale (spring and neap tides) and local processes (upwelling and tidal-topographic mixing) that shape planktonic assemblages in the Strait. To do so, an oceanographic cruise was taken in early autumn 2008 with a high-resolution grid sampling and spring/neap tidal conditions. The planktonic features were captured using different automatic and semi-automatic techniques of plankton analyses (flow cytometry, FlowCAM, LOPC and Ecotaxa) that allowed covering a wide range of sizes of the community from pico- to mesoplankton. The SG was sectorized into two clusters based on the biogeochemical and main water column properties. Cluster 1 (CL1) covered shallow productive areas around Cape Trafalgar (CT). CL1 presented higher concentrations of chlorophyll and nutrients, and phytoplankton was mostly represented by Synechococcus and coastal diatoms while zooplankton had the highest percentage of meroplankton (31%). In contrast, cluster 2 (CL2) covered open ocean waters and presented more oligotrophic features, i.e. nitrogen-depleted waters with lower chlorophyll concentrations and a picoplankton community dominated by Prochlorococcus and holoplankton predominance in mesozooplankton. Under early autumn conditions with overall nutrient-depleted and stratified waters, the CT area emerges as an ecosystem where the constant tidal mixing and nutrients supply is coupled with an active production also being favored by high residence times and finally shaping a plankton community with unique features in the area.En prensa0,56