1,683 research outputs found

    Valoración de las repercusiones cinemáticas en la extremidad inferior del antepié varo, en niños entre 7 y 10 años

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    El objetivo del estudio fue determinar las repercusiones cinemáticas del antepié varo (AV) en un grupo de niños de 7-10 años, tanto en estática como durante la marcha. Población: 30 niños con AV (9.3 ± 1.7 años; 6.1º ± 2.3º de AV), 21 niños control (GC) (9.2 ± 1.6 años). Se utilizaron los modelos “Oxford Foot” y “Plug-In-Gait” para analizar la cinemática, en estática y durante la marcha, en los 2 grupos (Sistema VICON, 6 cámaras). Para comparar todas las variables entre los dos grupos, se aplicó el t-test para muestras independientes, cuando los datos eran normales, y el test de Mann Whitney cuando no lo eran. En estática, el grupo AV presentó mayor eversión del retropié, descenso del arco longitudinal interno y una actitud en flexión de toda la extremidad inferior. Al caminar, este grupo presentó mayor eversión del retropié y aplanamiento del arco interno en todas las fases de la marcha analizadas; proximalmente, se observó mayor báscula anterior de la pelvis y flexión de las 3 grandes articulaciones de la extremidad inferior y mayor rotación externa de cadera. No existieron diferencias en la velocidad de la marcha, pero, para conseguir esta velocidad, el grupo AV necesitó mayor cadencia y una longitud y una duración de paso menor.The aim of this study was to determine the impact of the forefoot varus (FV) on the kinematics of the lower limb, in standing and during walking, in a group of children aged between 7 and 10 years. The Oxford Foot Model was used, simultaneously with a conventional lower limb model, to compare the kinematics of 10 forefoot varus children (9.3 ± 1.7 years; 6.1º ± 2.3º of FV) and 11 healthy controls (9.2 ± 1.6 years). Data acquisition was performed using a six-camera motion capture system. The independent t- test was used to compare normal data and the Mann-Whitney test to compare non-normal data. In standing, the FV group showed a higher hindfoot eversion, a lower height of the internal longitudinal arch and a higher flexion in the 3 main joints of the lower limb. During walking, this group presented a higher hindfoot eversion and a lower height of the internal longitudinal arch in all the studied phases; on the other hand, a higher pelvis anterior tilt, a higher flexion of the 3 main joints of the lower limb and a higher external rotation of the hip were found. There were no differences in the gait speed but, to achieve this speed, the FV group needed a higher cadence, due to a lower length and duration of the step.Peer Reviewe

    N=2 Supersymmetric Kinks and real algebraic curves

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    The kinks of the (1+1)-dimensional Wess-Zumino model with polynomic superpotential are investigated and shown to be related to real algebraic curves.Comment: 8 pages, LaTeX, epsfig, 4 figures include

    Graph search and beyond:SIGIR 2015 workshop summary

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    Modern Web data is highly structured in terms of entities and relations from large knowledge resources, geo-temporal references and social network structure, resulting in a massive multidimensional graph. This graph essentially unifies both the searcher and the information resources that played a fundamentally different role in traditional IR, and "Graph Search" offers major new ways to access relevant information. Graph search affects both query formulation (complex queries about entities and relations building on the searcher's context) as well as result exploration and discovery (slicing and dicing the information using the graph structure) in a completely personalized way. This new graph based approach introduces great opportunities, but also great challenges, in terms of data quality and data integration, user interface design, and privacy. We view the notion of "graph search" as searching information from your personal point of view (you are the query) over a highly structured and curated information space. This goes beyond the traditional two-term queries and ten blue links results that users are familiar with, requiring a highly interactive session covering both query formulation and result exploration. The workshop attracted a range of researchers working on this and related topics, and made concrete progress working together on one of the greatest challenges in the years to come

    Changing shapes: adiabatic dynamics of composite solitary waves

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    We discuss the solitary wave solutions of a particular two-component scalar field model in two-dimensional Minkowski space. These solitary waves involve one, two or four lumps of energy. The adiabatic motion of these composite non-linear non-dispersive waves points to variations in shape.Comment: 21 pages, 15 figures. To appear in Physica D: Nonlinear Phenomen

    Fracture test of a Gothic ribbed vault

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    A Gothic ribbed vault has been built at the School of Architecture of Madrid in order to investigate the construction complexities of this kind of vaults. The ribbed vault is described in the manuscript of Alonso de Vandelvira, and its shape was reconstructed making using the drawings this architect from the 16th century. The fracture test was carried on by loading the central keystone of the vault until its collapse took place. The experiment was filmed and by doing so, it was possible to observe the failure mechanism of the vault. At the same time, it was interesting to compare this collapse experience with the results obtained using two different me-thods. First, a stability calculation was carried out through graphic statics, and secondly a calcu-lation was performed using the rigid-block analysis method. The focus of this paper is to show and analyze the results of both studies

    Supersymmetry versus Integrability in two-dimensional Classical Mechanics

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    Supersymmetric extensions of Hamilton-Jacobi separable Liouville mechanical systems with two degrees of freedom are defined. It is shown that supersymmetry can be implemented in this type of systems in two independent ways. The structure of the constants of motion is unveiled and the entanglement between integrability and supersymmetry is explored.Comment: 28 pages, Added reference
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