2,837 research outputs found

    La erosión en campos cultivados en Galicia (NW España)

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    [Resumen] En la presente comunicación se realiza un seguimiento de la erosión en parcelas cultivadas en Galicia. Para ello, en la estación experimental El Pedroso se construyeron dos parcelas, de diferente pendiente, y se sometieron a un proceso de laboreo según las formas tradicionales de cultivar. En la presente comunicación se exponen los resultados del seguimiento de la experimentación desde abril a diciembre de 1995, en donde se observa que la pendiente desempeña una función distinta de la que en un principio podría pensarse, dado que la escorrentía y carga varían de forma inversa a la pendiente.[Abstract] A very closed study of erosion is made in this paper about plough plots in Galicia. For this, in the experimental station El Pedroso were built two plots, with different slope, and were ploughed in a traditional way. In this paper we resume the results of the experiment from april to december 1995, where it is seen that slope has a different function that was thought at the beginning of the experiment, because discharge and load don't vary directly with slope

    Evolución de la condición física en jugadoras de balonmano en las categorías infantil, cadete y juvenil

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    En la presente investigación se analiza la condición física de 91 jugadoras de balonmano, con edades comprendidas entre 13 y 18 años, distribuidas en tres categorías diferentes, infantil (n = 30), cadete (n = 32) y juvenil (n = 29). La investigación tiene carácter descriptivo y transversal. El principal objetivo es analizar la estructura condicional de las jugadoras. Para su valoración se aplicó la batería Eurofit, la batería de Bosco y test de Abalakov. Se encontraron diferencias significativas entre la categoría infantil-cadete en cinco de las 14 variables estudiadas, y ninguna entre la categoría cadete-juvenil. Los mejores resultados se produjeron en la categoría juvenil. En general, las restantes variables siempre alcanzaron mejores valores que la población escolar (en aquellas variables en las que la comparación fue posible), pero peores que los valores presentados por las jugadoras de las selecciones españolas. En las pruebas que valoraron la fuerza de tren inferior, los resultados indican que a mayor categoría las diferencias son menores entre categorías

    Precisión del posicionamiento en interiores utilizando Bluetooth con diferentes técnicas de reconocimiento de patrones

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    Object indoor location is a field that receives much research effort but that is lacking enough maturity for its integration in popular devices like mobile phones. This paper describes the results of an experiment carried out to compare different pattern recognition algorithms in order to process the information from a set of Bluetooth transmitters, located in fixed positions, with the aim of locating an object in a precise position. Our conclusion is that the best algorithms, among the five we tested, are random forests and model-based clustering, which gave accuracies around 90%. We have also conducted experiments to analyse the influence of the number of Bluetooth transmitters and to determine the sets of features with better performance. The proposed approach is simple and gives 90% of accuracy for locating objects with 1 m precision, making it suitable for a wide range of applications.Facultad de Informátic

    Multi-objective optimisation of product quality in the manufacture of Ti-6AI-4V prostheses

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    [EN] This paper presents a multi-objective optimisation procedure for optimising the quality of prostheses and manufacturing productivity. The aim of this procedure is to develop machining performance models through a minimal and progressive Design of Experiment (DoE), which models the variables of interest by linear regressions or Surface Response Models (SRMs). The multi-objective optimisation is based on desirability functions, which are defined according to the relative importance of each variable of interest. The procedure was implemented to optimise a process of manufacturing spherical turned components for Ti-6Al-4V hip prostheses with special requirements as regards surface roughness Ra, Rz and geometrical form toleranceThis work has been partially supported by Fundació Caixa-Castelló Bancaixa under the research project INV-2009-39. The authors are grateful to Miguel Angel Aymerich and Arcadi Sanz, who assisted in the experimental part. The authors extend their acknowledgements to Lafitt Company for its collaboration. Additional support was provided by Tecnológico de Monterrey through the research group in Mechatronics and Intelligent Machines.Abellán Nebot, JV.; Siller Carrillo, HR.; Vila, C.; Rodríguez González, CA. (2010). Multi-objective optimisation of product quality in the manufacture of Ti-6AI-4V prostheses. Journal of Manufacturing Technology Research. 5(3):353-369. https://doi.org/10.1504/IJMR.2010.033471S3533695

    proMetalloproteinase-10 is associated with brain damage and clinical outcome in acute ischemic stroke

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    BACKGROUND: Matrix metalloproteinases (MMPs) mediate tissue injury during stroke but also neurovascular remodeling and we have shown that MMP-10 is involved in atherothrombosis. OBJECTIVE: The purpose of this study was to examine the relationship between proMMP-10 and clinical outcome, assessing inflammatory and proteolytic markers, in patients with acute ischemic stroke. METHODS: We prospectively studied 76 patients with ischemic stroke treated with tPA within the first 3 h from symptom onset, compared with 202 non-tPA-treated ischemic stroke patients and 83 asymptomatic subjects. Stroke severity was assessed with the National Institutes of Health Stroke Scale (NIHSS). Hemorrhagic transformation (HT) and severe brain edema were diagnosed by cranial CT. Good functional outcome was defined as a modified Rankin scale score </= 2 at 90 days. Serum levels of MMP-9, proMMP-10, TIMP-1, tumor necrosis factor-alpha (TNFalpha), interleukin-6 and cellular fibronectin were measured at admission. The effect of TNFalpha on endothelial proMMP-10 was assessed in vitro. RESULTS: Serum proMMP-10 concentration in ischemic stroke patients, non-treated or treated with t-PA, which was higher than age-matched healthy subjects (P < 0.0001), was independently associated with higher infarct volume, severe brain edema, neurological deterioration and poor functional outcome at 3 months (all P < 0.05), but not with HT. proMMP-10 levels were also independently and positively associated with circulating levels of TNFalpha (P < 0.0001), which induced its endothelial expression in vitro, both mRNA and protein. MMP-9, however, was only associated with HT and severe edema (all P < 0.05). CONCLUSIONS: Increased serum proMMP-10 after acute ischemic stroke, associated with TNFalpha, is a new marker of brain damage and poor outcome

    A method for incorporating residual stresses into patient-specific finite element simulations of arteries with an example on AAAs

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    Through progress in medical imaging, image analysis and finite element (FE) meshing tools it is now possible to extract patient-specific geometries from medical images of abdominal aortic aneurysms(AAAs), and thus to study clinically-relevant problems via FE simulations. Such simulations allow additional insight into human physiology in both healthy and diseased states. Medical imaging is most often performed in vivo, and hence the reconstructed model geometry in the problem of interest will represent the in vivo state, e.g., the AAA at physiological blood pressure. However, classical continuum mechanics and FE methods assume that constitutive models and the corresponding simulations begin from an unloaded, stress-free reference condition

    Style Guidelines for Naming and Labeling Ontologies in the Multilingual Web

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    In the context of the Semantic Web, natural language descriptions associated with ontologies have proven to be of major importance not only to support ontology developers and adopters, but also to assist in tasks such as ontology mapping, information extraction, or natural language generation. In the state-of-the-art we find some attempts to provide guidelines for URI local names in English, and also some disagreement on the use of URIs for describing ontology elements. When trying to extrapolate these ideas to a multilingual scenario, some of these approaches fail to provide a valid solution. On the basis of some real experiences in the translation of ontologies from English into Spanish, we provide a preliminary set of guidelines for naming and labeling ontologies in a multilingual scenario

    3LD: towards high quality, industry-ready linguistic Linked Licensed Data

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    The application of Linked Data technology to the publication of linguistic data promises to facilitate interoperability of these data and has lead to the emergence of the so called Linguistic Linked Data Cloud (LLD) in which linguistic data is published following the Linked Data principles. Three essential issues need to be addressed for such data to be easily exploitable by language technologies: i) appropriate machine-readable licensing information is needed for each dataset, ii) minimum quality standards for Linguistic Linked Data need to be defined, and iii) appropriate vocabularies for publishing Linguistic Linked Data resources are needed. We propose the notion of Licensed Linguistic Linked Data (3LD) in which different licensing models might co-exist, from totally open to more restrictive licenses through to completely closed datasets

    Heart of Darkness: Heart Rate Variability on Patients with Risk of Suicide

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    Heart Rate Variability (HRV) is an emerging research field in the study of diverse pathologies, as long as it allows considering another measurement for detecting possible aggravations. The aim of this work is to study the applicability of the analysis of HRV in order to establish if a person is at risk of suffering from suicidal ideation. This work includes the development and testing of a heart rate acquisition and automatic analysis system, with friendly software for clinicians, customized to the necessities of an emergency unit. Furthermore, it includes the analysis of the obtained data with the purpose of assessing possible correlations between HRV parameters and personality impulsive traits. 20 patients and 10 normal cases were selected to develop this pilot study. Results show significant statistical difference (p<0.05) among patients and normal cases for pNN50, IRRR, MADRR, total HRV power, Approximate Entropy and Fractal Dimension

    Entorno didáctico de bajo coste para formación en tecnologías de cirugía guiada por imagen y robótica

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    Este trabajo de investigación presenta un nuevo entorno didáctico de bajo coste para la formación ingenieril de temáticas de cirugía guiada por imagen y robótica. Con este entorno se pretende mejorar la motivación y autonomía del alumnado, que hasta el momento se hallaba acotada debido al alto componente teórico de las sesiones impartidas. El entorno está formado por un phantom, una herramienta software, un sistema robótico y un manipulador que permite obtener una realimentación háptica. Se ha llevado a cabo una experiencia piloto en la asignatura de cuarto curso "Simulación y planificación quirúrgica" del Grado de Ingeniería Biomédica de la Universidad Politécnica de Madrid. Los resultados de las encuestas llevadas a cabo muestran que la nueva metodología mejora en todos los casos los valores obtenidos usando la metodología clásica basada en la clase magistral y prácticas
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