THE KINETIC CHAIN PERFORMED BY HIGH PERFORMANCE TENNIS PLAYERS

The tennis serve is one of the fundamental strokes in the development of the high performance tennis player. The aim of this study is to find the kinetic chain of two women professional tennis players’ serve by means of 3D photogrammetric. The sample was 12 and 14 flat tennis serves, recorded with high speed cameras at 125 Hz. Their mean serve speeds were 38.1 m/s and 41.4 m/s. The mean of the angular velocities were 618 and 415 º/s at the thorax, 416 and 197 º/s at the pelvis; and 1404 and 1962 º/s at the internal rotation of upper arm. The kinetic energy was the biomechanical parameter considered. In both cases there was found significant energy transference between the body segments. Also, the kinetic chains found did not follow the key events of maximum angular velocities. Their parameters and “timing” were different between each player, in the way that they showed two models which were no compatible each other

Training-induced changes in drag-flick technique in female field hockey players

The penalty corner is one of the most important goal plays in field hockey. The drag-flick is used less by women than men in a penalty corner. The aim of this study was to describe training-induced changes in the drag-flick technique in female field hockey players. Four female players participated in the study. The VICON optoelectronic system (Oxford Metrics, Oxford, UK) measured the kinematic parameters of the drag-flick with six cameras sampling at 250 Hz, prior to and after training. Fifteen shots were captured for each subject. A Wilcoxon test assessed the differences between pre-training and post-training parameters. Two players received specific training twice a week for 8 weeks; the other two players did not train. The proposed drills improved the position of the stick at the beginning of the shot (p<0.05), the total distance of the shot (p<0.05)and the rotation radius at ball release (p<0.01). It was noted that all players had lost speed of the previous run. Further studies should include a larger sample, in order to provide more information on field hockey performance

Secuencia temporal en el swing de golf de jóvenes promesas

The golf swing is a skill which could be classified as a high velocity hitting where the main goal is that the head of the golf club reaches its maximum velocity at impact time. Ten golf swings executed by four young players were biomechanicaly analyze. Automatic capture with Vicon Oxford Metrics © was used. The absolute values of the linear velocities were higher at men that at women. At the interval analysis, the downswing presented less variation than the backswing. The analisis of the maximum timing sequence showed that depending on the gender they described different order. At men, the secuence started with the hip movement, followed by, left elbow, left shoulder and the club head. At women the hips and left elbow occurred simultaneously followed by the left shoulder and the club head. El swing en golf es una destreza que podríamos catalogar de golpeo de velocidad donde el objetivo es que la cara del palo alcance la máxima velocidad en el momento del impacto. Se han analizado biomecánicamente diez golpeos de cuatro jugadores promesas, mediante el sistema fotogrametría 3D Vicon Oxford Metrics © de captura automática. En primer lugar se ha podido comprobar que los valores absolutos de velocidades lineales eran mayores en los chicos que en los chicas. El análisis de las dos fases del swing indica que la fase de aceleración (downswing) presenta una variabilidad menor que el backwing. El análisis de la secuencia temporal de máximos alcanzados en los segmentos muestra cómo las aEcciones de los mismos siguen un orden diferente en función del género. La secuencia en los chicos empieza por el movimiento de caderas y sigue con el codo izquierdo, el hombro izquierdo y el palo; en las chicas, las caderas y el codo izquierdo actúan simultáneamente seguidos del hombro izquierdo y del palo.Peer Reviewe

La formación continua del profesorado en educación intercultural: estereotipos y heurísticos

Esta comunicación tiene por objetivo abordar la importancia de la educación intercultural en la formación continua del profesorado. Se pretende, por un lado, examinar los contenidos que la formación en educación intercultural para profesorado debe incluir y, por otro, analizar las necesidades, conocimientos y la situación de los docentes. Primeramente, se realiza un repaso teórico de los diferentes aspectos que la educación intercultural abarca y a continuación, se presenta la experiencia docente y la línea de investigación sobre la competencia intercultural llevada a cabo entre el profesorado de Primaria y Secundaria participante en el curso “La Educación Intercultural en la Práctica” de Formación Permanente ofrecido por el Departamento de Educación del Gobierno Vasco. Así, en la formación del profesorado se parte del propio conocimiento y la reflexión continua sobre las experiencias profesionales. Aunque un sector del profesorado todavía no ha recibido nunca formación sobre competencias interculturales, muchos docentes valoran la necesidad de formarse porque tienen el reto diario de abordar la diversidad en el centro educativo. Por lo tanto, se parte de la reflexión sobre la práctica y se interrelaciona la teoría y la práctica constantemente. Con respecto a los contendidos, resulta necesario definir, formular y explicar adecuadamente varias cuestiones: ¿Qué es y qué no es educación intercultural?, ¿Cómo ampliar el repertorio de prácticas inclusivas y metodologías para la diversidad?, ¿Por qué los estereotipos y prejuicios suponen un obstáculo para la convivencia intercultural? etc. En efecto, la mayoría de los expertos entienden la educación intercultural (Aguado, Gil Jaurena y Mata, 2005; Besalú, 2002; Carbonell, 2000) desde un enfoque holístico e inclusivo, y como un proceso de transformación que envuelve a toda la comunidad educativa con el fin de construir la equidad educativa y la justicia social. Así, las competencias y temas a desarrollar en un programa de formación son amplios y variados: La educación intercultural y el alumnado (necesidades del alumnado, convivencia escolar…), el profesorado (curriculum intercultural, practicas inclusivas…), las familias (participación en el contexto educativo, formación…), la organización escolar (utilización de recursos comunitarios, proyectos educativos…), etc. Finalmente, con respecto a la línea de investigación sobre la competencia intercultural del profesorado, se analiza cuáles son los estereotipos más comunes que el profesorado posee sobre el alumnado inmigrante y cómo influye el razonamiento heurístico en los juicios y consideraciones sobre la inmigración. Para ello, se proponen distintas acciones educativas de cara a prevenir estos efectos negativos y promover así la educación en y para la diversidad. En definitiva, como se recogen en las directrices de la UNESCO (2006) es necesaria una formación docente inicial adecuada y una formación profesional permanente que brinde a los profesores, entre otros aspectos, una profunda comprensión del paradigma intercultural en la educación y su importancia para la transformación de la práctica cotidiana en las aulas, las escuelas y las comunidades. Y, para ello, es necesario seguir investigando cómo se forman y cómo funcionan los estereotipos y sus relaciones con el razonamiento heurístico

Real time plasma disruptions detection in JET implemented with the ITMS platform using FPGA based IDAQ

The use of FPGAs in data acquisition cards for processing purposes allows an efficient real time pattern recognition algorithm implementation. Using 13 JETs database waveforms an algorithm for detecting incoming plasma disruptions has been implemented. This algorithm is written in MATLAB using floating point representation. In this work we show the methodology used to implement the real time version of the algorithm using Intelligent Data Acquisition Cards (IDAQ), DAQ devices with field programmable gate array (FPGA) for local processing. This methodology is based on the translation of the MATLAB code to LabVIEW and the final coding of specific pieces of code in LabVIEW for FPGA in fixed point format. The whole system for evaluating the real time disruption detection (RTDD) has been implemented using the Intelligent Test and Measurement System (ITMS) platform. ITMS offers distributed data acquisition, distribution and real time processing capabilities with advanced, but easy to use, software tools that simplify application development and system setup. The RTDD implementation uses a standard PXI/PXIe architecture. Two 8 channel analog output cards play JETs database signals, two 8 channel DAQ with FPGA acquire signals and computes a feature vector based in FFT analysis. Finally the vector acquired is used by the system CPU to execute a pattern recognition algorithm to estimate an incoming disruption

Iatrogenic salivary duct injury in head and neck cancer patients: report of four cases and review of the literature

Introduction: The lesions of the salivary ducts may be idiopathic, post- traumatic, or iatrogenic and lead to sialocele formation with persistent painful facial swelling or cutaneous fistula formation. No consensus on treatment of this condition exists: the options of treatment include needle aspiration, pressure dressings, antisialogogue therapy, radiotherapy, botulinum toxin and surgical approaches as duct repair, diversion, ligation, different drainage systems and even parotidectomy/submaxilectomy. The management and special features of iatrogenic salivary duct injury in patients with oral cancer who underwent head and neck reconstructive surgery has not been described yet. Material and Methods: We present four cases of iatrogenic lesions of salivary ducts and its management in patients with oral cancer. Conclusions: The iatrogenic lesions of salivary ducts are to be taken into account in patients with oral cancer as the distal ends of salivary ducts could be involved in the margins of surgical resection. Different options of treatment of this complication are described

A Cholinergic Synaptically Triggered Event Participates in the Generation of Persistent Activity Necessary for Eye Fixation

An exciting topic regarding integrative properties of the nervous system is how transient motor commands or brief sensory stimuli are able to evoke persistent neuronal changes, mainly as a sustained, tonic action potential firing. A persisting firing seems to be necessary for postural maintenance after a previous movement. We have studied in vitro and in vivo the generation of the persistent neuronal activity responsible for eye fixation after spontaneous eye movements. Rat sagittal brainstem slices were used for the intracellular recording of prepositus hypoglossi (PH) neurons and their synaptic activation from nearby paramedian pontine reticular formation (PPRF) neurons. Single electrical pulses applied to the PPRF showed a monosynaptic glutamatergic projection on PH neurons, acting on AMPA-kainate receptors. Train stimulation of the PPRF area evoked a sustained depolarization of PH neurons exceeding (by hundreds of milliseconds) stimulus duration. Both duration and amplitude of this sustained depolarization were linearly related to train frequency. The train-evoked sustained depolarization was the result of interaction between glutamatergic excitatory burst neurons and cholinergic mesopontine reticular fibers projecting onto PH neurons, because it was prevented by slice superfusion with cholinergic antagonists and mimicked by cholinergic agonists. As expected, microinjections of cholinergic antagonists in the PH nucleus of alert behaving cats evoked a gaze-holding deficit consisting of a re-centering drift of the eye after each saccade. These findings suggest that a slow, cholinergic, synaptically triggered event participates in the generation of persistent activity characteristic of PH neurons carrying eye position signals.Unión Europea Grants BI04-CT98-0546España, Ministerio de Ciencia PB98-0011, BFI2000-00936, BFI2000-1190, y BFI2002-0137

Ultrasound imaging evaluation of textural features in athletes with soleus pathology : a novel case-control study

Background: the aim of this study was to compare the echotexture of patients with soleus muscle injury and age matched controls. Methods: a sample of 62 athletes was recruited at the private clinic and was divided in two group: a healthy group (n = 31) and a soleus pathology group whose athletes had soleus muscle injury, located in the central tendon (n = 31). The muscle thickness (MTh), echointensity (EI) and echovariation (EV) were analyzed. An intra-rater reliability test (Intraclass Correlation Coefficient-ICC) was performed in order to analyze the reliability of the values of the measurements. Results: Sociodemographic variables did not show statistically significant differences (p > 0.05). Ultrasound imaging measurements who reported statistically significant differences were EI (p = 0.001) and standard deviation (SD) (p = 0.001). MTh and EV variables did not show statistically significant differences (p = 0.381 and p = 0.364, respectively). Moreover, reliability values for the MTh (ICC = 0.911), EI (ICC = 0.982), SD (ICC = 0.955) and EV (ICC = 0.963). Based on these results the intra-rater reliability was considered excellent. Conclusion: Athletes with a central tendon injury of soleus muscle showed a lower EI when they were compared to healthy athletes. The echogenicity showed by the quantitative ultrasound imaging measurement may be a more objective parameter for the diagnosis and follow-up the soleus muscle injurie

Exploiting graphic processing units parallelism to improve intelligent data acquisition system performance in JET's correlation reflectometer

The performance of intelligent data acquisition systems relies heavily on their processing capabilities and local bus bandwidth, especially in applications with high sample rates or high number of channels. This is the case of the self adaptive sampling rate data acquisition system installed as a pilot experiment in KG8B correlation reflectometer at JET. The system, which is based on the ITMS platform, continuously adapts the sample rate during the acquisition depending on the signal bandwidth. In order to do so it must transfer acquired data to a memory buffer in the host processor and run heavy computational algorithms for each data block. The processing capabilities of the host CPU and the bandwidth of the PXI bus limit the maximum sample rate that can be achieved, therefore limiting the maximum bandwidth of the phenomena that can be studied. Graphic processing units (GPU) are becoming an alternative for speeding up compute intensive kernels of scientific, imaging and simulation applications. However, integrating this technology into data acquisition systems is not a straight forward step, not to mention exploiting their parallelism efficiently. This paper discusses the use of GPUs with new high speed data bus interfaces to improve the performance of the self adaptive sampling rate data acquisition system installed on JET. Integration issues are discussed and performance evaluations are presente

El patró de moviment en el swing de golf en joves promeses

El swing de golf és una destresa que podríem catalogar de cop de velocitat en què l&apos;objectiu és que la cara del pal assoleixi la màxima velocitat en el moment de l&apos;impacte. L&apos;objectiu d&apos;aquest estudi va ser analitzar la seqüència temporal del swing de golf i trobar-ne el patró de moviment. Mètodes: S&apos;han analitzat biomecànicament 10 cops de 4 jugadors promeses, mitjançant el sistema de fotogrametria 3D Vicon Oxford Metrics® de captura automàtica. Resultats: En primer lloc, s&apos;ha pogut comprovar que els valors absoluts de velocitats lineals eren més alts en els nois que en les noies. L&apos;anàlisi de les dues fases del swing indica que la fase d&apos;acceleració downswing presenta una variabilitat menor que el backswing. L&apos;anàlisi de la seqüència temporal de màxims aconseguits en les velocitats lineals dels segments mostra com aquestes accions segueixen un ordre diferent en funció del sexe. La seqüència en els nois comença pel moviment de malucs i segueix amb el colze esquerre, l&apos;espatlla esquerra i el pal; en les noies, els malucs i el colze esquerre actuen simultàniament, seguits de l&apos;espatlla esquerra i del pal. En canvi, les seqüències de velocitats angulars trobades seguien en ambdós sexes el mateix ordre: primer el gir de malucs, després el gir d&apos;espatlles i per últim l&apos;acceleració del pal. Aquesta seqüència d&apos;esdeveniments es trobava més separada en el temps en els homes en comparació amb les dones. Conclusions: Es van trobar els patrons del moviment mitjançant fórmules discriminants en ambdós grups de gènere, capaços de predir si el cop seria "bo" o "dolent" seguint el criteri de rendiment marcat en la velocitat del cap del pal