9,834 research outputs found

    Left wind forward in football (soccer). Khinanthropometry and footprint analysis

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    Kinanthropometry is the study of size, shape, proportionality, body composition, biological maturation and body function with the objective of understanding the process of growth, exercise, sport performance and nutrition. It has been accepted measurements in the right side of the subject as equivalent of the overall sportsman. Right and left side variations therefore have not been sufficiently studied, particularly in left handed football players. Materials and Methods: Analysis of 5 professional footballers from the C.D. Leganés, S.A.D. was carried, being left dominant and by their team position considered as left wing forwards. The method selected to study kinanthropometric variables was established by Heath-Carter and followed by the ISAK-GREC (International Society for the Advancement of Kinanthropometry and Grupo Español de Cineantropometría-Spanish Group of Kinanthropometry-). Footprint obtained by the simplified Hernandez-Corvo methodology, being classified as: flat, flat-normal, normal, normal-high arch, high arch, strong high arch and extreme high arch, prior and subsequent to a football match. Informed consent attained as established by local legislation. Statistics analysed by t-Student with a significance of 95% (p<0.05) and the results processed by the PC statistical software SPSS 11.5. Results: Football players have a mean height of 174.02 cm. and a mean weight of 75.32 Kg. Right foot mean length is 24.84 cm. and left foot mean length is 24.96 cm., while right foot mean width is 9.73 cm. and left foot mean width is 9.60 cm.; the footprint varies from normal prior to match to normal- high arch after the game, whereas left foot remains normal-high arch all along. Total number of lesions accounted for 9 sprains in the right ankle and 12 sprains in left ankle, 1 anterior cruciate ligament rupture and 1 menisectomy in the right knee with 1 interior lateral ligament rupture and 1 menisectomy in the left knee. Discussion: Data in variation of right and left side related to football is missing in international bibliography, which may be important due to the fact of the general belief in football environment that left dominant footballers are of better technique and therefore will have more chance of success in a world ruled by financial interests. Notice to analysis remarks the fact whereas the mean left foot is longer than the mean right foot, the mean right foot is wider than the mean left foot. Statistical significant differences arise between left and right footprint prior and subsequent to a football match, associated to statistical significant changes in various anthropometric measurements: ileospinal, throcanteric and tibial heights; total superior extremity, arm, forearm, hand, thigh, leg and foot lengths; subescapular, axillary, ileocrestal, supraspinal, thigh, leg and abdominal skinfolds; epicondyle of humerus diameter and ankle perimeter. Conclusion: 1) Footprint modifies with football practice. 2) Footprint differs in a football player in left and right feet prior and subsequent to a football match, associated with statistical discrepancies between various right and left kinanthropometric variables. 3) Broader population must be studied to better value the repercussion of football practice in footprint. 4) Research must be completed in order to analyse modification in right handed football players. 5) Research must be completed in order to analyse modification of footprint because of sport practice. 6) Research must be completed to observe differences with similar population detailing in certain sportive gestures (running, jumping, swimming, etc.)

    Estimación del grado de desarrollo de la composición corporal en deportistas púberes y prepúberes

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    Un valioso elemento en la vigilancia de la salud pediátrica es la gráfica de recimiento, que relaciona en curvas de percentil la edad con el peso y la talla. Bastante útiles en edades preescolares, son poco representativas de los cambios producidos en etapas adolescentes en las que se añade al crecimiento normal, los cambios fisiológicos propios del desarrollo puberal y factores ambientales tales como la practica de actividades deportivas, que pueden inducir un desarrollo diferente de cada componente corporal. Aplicando el método antropométrico se calcula la composición corporal de 300 escolares entre 10 y 15 años, estudiando el fraccionamiento del peso corporal en 4 componentes. Los objetivos del presente estudio son: conocer cómo cambian los distintos componentes corporales durante las etapas preadolescente y adolescente de los individuos que realizan deporte extraescolar y obtener gráficas de crecimiento para cada componente similares a las existentes para la correlación edad/peso, edad/talla, peso/talla aceptadas por la OMS y de idéntico manejo, que muestren las variables en percentiles por edad, no en términos de proporción del peso total, sino en valor absoluto para cada componente, de modo que permitan monitorizar el desarrollo de cada individuo, resultando así de utilidad en la práctica clínica diaria.Los resultados de la artroplastia de codo han mejorado sustancialmente coincidiendo con el mejor conocimiento de la biomecánica del codo. El diseño y los resultados clínicos de las prótesis de codo se basan en un conocimiento preciso de la cinemática, los estabilizadores y las fuerzas que atraviesan esta articulación.A valuable element in the vigilance of the pediatric health is the graph of growth which relates in curves of percentile the age with the weight and the height. Very useful in preschool ages, they are not very representative in the changes of the adolescent stages in which, to the normal growth, it adds the physiologic changes characteristic of the development puberal and environmental factors just as practice of sport activities that can induce a different development in each corporal component. Applying the anthropometric method, the body composition of 300 scholars, between 10 and 15 years old, is calculated, studying the division of the corporal mass according to four compartment model. The objectives of the present study are: to know the change of the different corporal components during the preadolescent and adolescent stages of the people whom practice extra-school sport and to obtain graphics of growth for each component similar to the existent ones for the correlation age/weight, age/height, weight/height accepted by the WHO and of identical handling that show the variables in percentiles for age, not in terms of proportion of the total weight, but in absolute value for each component, so they allow to monitor the development of each person, being that utility in the everyday clinical practice

    Human-in-the-Loop Model Predictive Control of an Irrigation Canal

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    Until now, advanced model-based control techniques have been predominantly employed to control problems that are relatively straightforward to model. Many systems with complex dynamics or containing sophisticated sensing and actuation elements can be controlled if the corresponding mathematical models are available, even if there is uncertainty in this information. Consequently, the application of model-based control strategies has flourished in numerous areas, including industrial applications [1]-[3].Junta de Andalucía P11-TEP-812

    Structural and optoelectronical characterization of Si-SiO_2/SiO_2 multilayers with applications in all Si tandem solar cells

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    SiO_2 multilayers with embedded Si nanocrystals (Si-ncs) were investigated as an approach for developing highly efficient all Si tandem solar cells. The nanostructured samples, fabricated by means of a reactive magnetron sputtering, were structurally and optoelectronically characterized using different techniques. High resolution transmission electron microscopy (TEM) and energy filtered images in TEM show a high density of Si-nc with uniform sizes below 4 nm, while electrical characterization indicates high resistance values (10^2 kΩ) of these samples. In order to develop a better understanding of the optoelectronical behavior, photocurrent I-V curves were measured, obtaining variations under "dark" or "illumination" conditions. Recombination lifetimes in the order of tenths of nanoseconds were estimated by applying the transverse pump/probe technique

    Un estudi sobre interdisciplinarietat, professions socials i acció socioeducativa

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    Aquest article és el relat d'un seguit d'accions encetades per donar resposta a una serie de preguntes referides a l'àmbit de la intervenció socioeducativa. El que volíem era conèixer I'estat de la interdisciplinarietat en I'àmbit de les accions socioeducatives professionals. En quin grau i de quina manera conflueixen les diferents disc iplines en I'acció social o socioeducativa? Quines professions i professionals d'alló social van desenvolupant aquestes accions? Quines relacions -de col·laboració; de confrontació; d'aïllament, etc.- es produeixen entre elles? I, per últim, ens preguntàvem: existeix una consciència entre els i les professionals sobre la necessitat -o no- d'aquesta interdisciplinarietat

    On the relation between virial coefficients and the close-packing of hard disks and hard spheres

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    The question of whether the known virial coefficients are enough to determine the packing fraction η\eta_\infty at which the fluid equation of state of a hard-sphere fluid diverges is addressed. It is found that the information derived from the direct Pad\'e approximants to the compressibility factor constructed with the virial coefficients is inconclusive. An alternative approach is proposed which makes use of the same virial coefficients and of the equation of state in a form where the packing fraction is explicitly given as a function of the pressure. The results of this approach both for hard-disk and hard-sphere fluids, which can straightforwardly accommodate higher virial coefficients when available, lends support to the conjecture that η\eta_\infty is equal to the maximum packing fraction corresponding to an ordered crystalline structure.Comment: 10 pages, 6 figures; v2: discussion about hard-square and hard-hexagon systems on a lattice added; five new reference

    The structure of Chariklo's rings from stellar occultations

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    Two narrow and dense rings (called C1R and C2R) were discovered around the Centaur object (10199) Chariklo during a stellar occultation observed on 2013 June 3. Following this discovery, we planned observations of several occultations by Chariklo's system in order to better characterize the physical properties of the ring and main body. Here, we use 12 successful occulations by Chariklo observed between 2014 and 2016. They provide ring profiles (physical width, opacity, edge structure) and constraints on the radii and pole position. Our new observations are currently consistent with the circular ring solution and pole position, to within the ±3.3\pm 3.3 km formal uncertainty for the ring radii derived by Braga-Ribas et al. The six resolved C1R profiles reveal significant width variations from 5\sim 5 to 7.5 km. The width of the fainter ring C2R is less constrained, and may vary between 0.1 and 1 km. The inner and outer edges of C1R are consistent with infinitely sharp boundaries, with typical upper limits of one kilometer for the transition zone between the ring and empty space. No constraint on the sharpness of C2R's edges is available. A 1σ\sigma upper limit of 20\sim 20 m is derived for the equivalent width of narrow (physical width <4 km) rings up to distances of 12,000 km, counted in the ring plane
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