272 research outputs found

    La digitalización de la palabra escrita

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    Las reflexiones que inspiran este artículo se enmarcan en los supuestos teóricos que desarrollamos en el Centro de Investigación de la Universidad Nacional de la Patagonia Austral, Unidad Académica Río Gallegos, centro en el cual desempeñamos nuestras tareas. Fundamentamos nuestros aportes desde miradas interdisciplinarias que se conjugan para iluminar el objeto de conocimiento que intentamos develar: los procesos de lectura mediados por instrumentos digitales. A lo largo de nuestra trayectoria como docentes investigadores hemos advertido que los procesos de lectura se hallan atravesados por prácticas culturales de uso mediadas por las tecnologías de la información que evidentemente producen no sólo nuevos hábitos lectores sino que también desarrollan rutinas lectoras que configuran nuevas modalidades de comprensión y de representación de los significados expuestos en los textos. Hallamos una redefinición de los gustos y estilos preferidos por los lectores, así como una reestructuración de los textos escolares en los cuales se evidencia el atravesamiento de los procesos hipertextuales y de digitalización que deben ser contemplados a fin de establecer propuestas didácticas apropiadas.The observations which inspire this article are framed around the basic theoretical assumptions that we develop at the Investigation Centre of the National University of Austral Patagonia, Academic Unit Río Gallegos, centre in which we perform our tasks. We base our contributions on interdisciplinary sights which conjugate to illuminate the object of knowledge that we try to unveil: lecture processes mediated by digital instruments. Throughout our career as educational investigators, we have noticed that reading processes occur to be traversed by cultural practices of use mediated by IT technologies which obviously produce not only new reading habits, but also develop reading routines which set up new comprehension and representation modalities of meanings represented in texts. We find a redefinition of taste and style preferred by the readers, as well as the restructuring of school textbooks in which the traversing of hypertext and digitalization processes which must be considered in order to establish proper didactic proposals is evidenced

    Relationships between adolescent physical self-concept and physical activity

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    El objetivo de este estudio es someter a prueba dos modelos contrapuestos sobre las relaciones entre las autopercepciones físicas y la actividad físico-deportiva en la adolescencia: mientras que un modelo postula la influencia de la actividad física sobre el autoconcepto físico, el modelo alternativo propone al autoconcepto físico como factor influyente en la actividad físicodeportiva. Participan en la investigación 704 estudiantes, 394 (55.96 %) hombres y 310 (44.04 %) mujeres entre 11 y 19 años (M = 14.91; D.T. = 2.13), residentes en dos Comunidades Autónomas (Cantabria y País Vasco) de España. Los resultados indican que las influencias entre el autoconcepto físico y la actividad físico-deportiva se producen de forma bidireccional si bien ajusta mejor el modelo que propone al autoconcepto físico como factor influyente. Se comprueban diferencias entre hombres y mujeres en el modelo. Por otro lado, la autopercepción de atractivo físico mantiene una relación negativa con la actividad físico-deportivaThe aim of this study is to test two opposing models of the relationship between physical self-perceptions and physical activity during adolescence: one which postulates that physical activity influences physical self-concept, and another one which proposes that physical self-concept influences physical activity. Participants were 704 students aged between 11 and 19 (M = 14.91; SD = 2.13) from two different Autonomous Regions in Spain (Cantabria and the Basque Country). 394 (55.96%) were male and 310 (44.04%) were female. The results indicate that the influences between physical self-concept and physical activity are bidirectional in nature, although the model that proposes physical selfconcept as an influencing factor was found to have a better fitness. Differences were found in the model between male and female students. Furthermore, selfperception of physical attractiveness was found to be negatively related to physical activityEste artículo lo firman componentes del Grupo Consolidado de Investigación del Sistema Universitario Vasco IT701-13 y forman parte de los resultados del proyecto EDU2009-10102 (subprograma EDUC) subvencionado por el MICINN. La investigación se ha realizado con la colaboración del Programa para la Contratación de Doctores Recientes de la Universidad del País Vasco (UPV/EHU

    Tracking with Sparse and Correlated Measurements via a Shrinkage-based Particle Filter

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    This paper presents a shrinkage-based particle filter method for tracking a mobile user in wireless networks. The proposed method estimates the shadowing noise covariance matrix using the shrinkage technique. The particle filter is designed with the estimated covariance matrix to improve the tracking performance. The shrinkage-based particle filter can be applied in a number of applications for navigation, tracking and localization when the available sensor measurements are correlated and sparse. The performance of the shrinkage-based particle filter is compared with the posterior Cramer-Rao lower bound, which is also derived in the paper. The advantages of the proposed shrinkage-based particle filter approach are demonstrated via simulation and experimental results

    Evolution of residual stresses induced by machining in a Nickel based alloy under static loading at room temperature

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    Tensile residual stresses are very often generated on the surface when machining nickel alloys. In order to determine their influence on the final mechanical behaviour of the component residual stress stability should be considered. In the present work the evolution of residual stresses induced by machining in Inconel 718 under static loading at room temperature has been studied. An Inconel 718 disc has been face turned and specimens for tensile tests have been extracted from the disc. Then surface residual stresses have been measured by X-ray diffraction for initial state and different loading levels. Finally, a finite element model has been fitted to experimental results and the study has been extended for more loading conditions. For the studied case, it has been observed that tensile residual stresses remain stable when applying elastic loads but they increase at higher loads close to the yield stress of the material

    Impact of HF radar current gap-filling methodologies on the Lagrangian assessment of coastal dynamics

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    High-frequency radar, HFR, is a cost-effective monitoring technique that allows us to obtain high-resolution continuous surface currents, providing new insights for understanding small-scale transport processes in the coastal ocean. In the last years, the use of Lagrangian metrics to study mixing and transport properties has been growing in importance. A common condition among all the Lagrangian techniques is that complete spatial and temporal velocity data are required to compute trajectories of virtual particles in the flow. However, hardware or software failures in the HFR system can compromise the availability of data, resulting in incomplete spatial coverage fields or periods without data. In this regard, several methods have been widely used to fill spatiotemporal gaps in HFR measurements. Despite the growing relevance of these systems there are still many open questions concerning the reliability of gap-filling methods for the Lagrangian assessment of coastal ocean dynamics. In this paper, we first develop a new methodology to reconstruct HFR velocity fields based on self-organizing maps (SOMs). Then, a comparative analysis of this method with other available gap-filling techniques is performed, i.e., open-boundary modal analysis (OMA) and data interpolating empirical orthogonal functions (DINEOFs). The performance of each approach is quantified in the Lagrangian frame through the computation of finite-size Lyapunov exponents, Lagrangian coherent structures and residence times. We determine the limit of applicability of each method regarding four experiments based on the typical temporal and spatial gap distributions observed in HFR systems unveiled by a K-means clustering analysis. Our results show that even when a large number of data are missing, the Lagrangian diagnoses still give an accurate description of oceanic transport properties.</p

    Daily scale wintertime sea surface temperature and IPC-Navidad variability in the southern Bay of Biscay from 1981 to 2010

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    The combination of remotely sensed gappy Sea surface temperature (SST) images with the missing data filling DINEOF (data interpolating empirical orthogonal functions) technique, followed by a principal component analysis of the reconstructed data, has been used to identify the time evolution and the daily scale variability of the wintertime surface signal of the Iberian Poleward Current (IPC), or Navidad, during the 1981-2010 period. An exhaustive comparison with the existing bibliography, and the vertical temperature and salinity profiles related to its extremes over the Bay of Biscay area, show that the obtained time series accurately reflect the IPC-Navidad variability. Once a time series for the evolution of the SST signal of the current over the last decades is well established, this time series is used to propose a physical mechanism in relation to the variability of the IPC-Navidad, involving both atmospheric and oceanic variables. According to the proposed mechanism, an atmospheric circulation anomaly observed in both the 500 hPa and the surface levels generates atmospheric surface level pressure, wind-stress and heat-flux anomalies. In turn, those surface level atmospheric anomalies induce mutually coherent SST and sea level anomalies over the North Atlantic area, and locally, in the Bay of Biscay area. These anomalies, both locally over the Bay of Biscay area and over the North Atlantic, are in agreement with several mechanisms that have separately been related to the variability of the IPC-Navidad, i.e. the south-westerly winds, the joint effect of baroclinicity and relief (JEBAR) effect, the topographic beta effect and a weakened North Atlantic gyre.ERA-Interim data were obtained from the ECMWF data server (http://data.ecmwf.int/data). Pathfinder v5.2 data were provided by GHRSST and the US National Oceanographic Data Center. AMSR-E data are produced by Remote Sensing Systems and sponsored by the NASA Earth Science MEaSUREs DISCOVER Project and the AMSR-E Science Team. Data are available at www.remss.com. The altimeter products were produced by Ssalto/Duacs and distributed by Aviso, with support from Cnes (http://www.aviso.oceanobs.com/duacs/). ICOADS data for this study have been retrieved from the Research Data Archive (RDA) which is maintained by the Computational and Information Systems Laboratory (CISL) at the National Center for Atmospheric Research (NCAR). Word Ocean Database data were obtained from http://www.nodc.noaa.gov/OC5/WOD/pr_wod.html. DINEOF source code is freely available at http://modb.oce.ulg.ac.be/mediawiki/index.php/DINEOF. G. Esnaola is supported by a research grant (Interaccion Atmosfera-Oceano en el Golfo de Bizkaia) from Fundacion Centros Tecnologicos Inaki Goenaga. Jon Saenz would like to thank the financial support from project CGL2008-03321 (Spanish National R+D+I Programme). He also thanks funding provided by the University of the Basque Country (UFI 11/55, PPH12/01 and GIU 11/01). The Basque Government (Department of Agriculture, Fisheries and Food) has funded the project VARIACIONES. The authors want to express their gratitude to A. Caballero from AZTI-Tecnalia for her help with the Altimetry data and to B. Le Cann from UBO-CNRS-IRD-IFREMER for his useful comments on an early draft of this document. This is contribution number 649 of the Marine Research Division of AZTI-Tecnalia

    Digitalización de los contenidos curriculares

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    Variability in the air–sea interaction patterns and timescales within the south-eastern Bay of Biscay, as observed by HF radar data

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    Two high-frequency (HF) radar stations were installed on the coast of the south-eastern Bay of Biscay in 2009, providing high spatial and temporal resolution and large spatial coverage of currents in the area for the first time. This has made it possible to quantitatively assess the air–sea interaction patterns and timescales for the period 2009–2010. The analysis was conducted using the Barnett–Preisendorfer approach to canonical correlation analysis (CCA) of reanalysis surface winds and HF radar-derived surface currents. The CCA yields two canonical patterns: the first wind–current interaction pattern corresponds to the classical Ekman drift at the sea surface, whilst the second describes an anticyclonic/cyclonic surface circulation. The results obtained demonstrate that local winds play an important role in driving the upper water circulation. The wind–current interaction timescales are mainly related to diurnal breezes and synoptic variability. In particular, the breezes force diurnal currents in waters of the continental shelf and slope of the south-eastern Bay. It is concluded that the breezes may force diurnal currents over considerably wider areas than that covered by the HF radar, considering that the northern and southern continental shelves of the Bay exhibit stronger diurnal than annual wind amplitudes

    From the portal to the classroom: interactions of digital teaching materials

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    En estas líneas se presentan los resultados de un estudio descriptivo cuyos objetivos principales son conocer los portales instituciones de dos países, analizar la oferta de materiales didácticos digitales dirigidos a la etapa de Educación Primaria y realizar una serie de recomendaciones o propuestas para modificar las prácticas docentes hacia un modelo de enseñanza mediada por tecnología. Los resultados indican la existencia de portales institucionales que se considera una de las principales fuentes de materiales didácticos digitales utilizadas por los docentes para acceder a recursos útiles en la escuela del siglo XXI. Partiendo de esta realidad se concluye la necesidad de formación del profesorado en competencia digital, la dotación de dispositivos en los centros educativos y el desarrollo de una cultura de cooperación entre docentes para compartir recursos educativos en abierto. Esto permitirá modificar las prácticas de aula que en muchos casos siguen estando ancladas en el pasadoThese lines present the results of a descriptive study whose main objective is to know the institutions' portals of two countries, analyze the offer of digital teaching materials aimed at the Primary Education stage and make a series of recommendations or proposals to modify teaching practices towards a model of technology-mediated teaching. The results indicate the existence of institutional portals that are considered one of the main sources of digital teaching materials used by teachers to access useful resources in the 21st century school. Based on this reality, the need for teacher training in digital competence, the provision of devices in schools and the development of a culture of cooperation among teachers to share educational resources in the open is concluded. This will allow the modification of classroom practices that in many cases remain anchored in the pas

    Why does Spain have smaller inequalities in mortality?

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    Background: While educational inequalities in mortality are substantial in most European countries, they are relatively small in Spain. A better understanding of the causes of these smaller inequalities in Spain may help to develop policies to reduce inequalities in mortality elsewhere. The aim of the present study was therefore to identify the specific causes of death and determinants contributing to these smaller inequalities. Methods: Data on mortality by education were obtained from longitudinal mortality studies in three Spanish populations (Barcelona, Madrid, the Basque Country), and six other Western European populations. Data on determinants by education were obtained from health interview surveys. Results: The Spanish populations have considerably smaller absolute inequalities in mortality than other Western European populations. This is due mainly to smaller inequalities in mortality from cardiovascular disease (men) and cancer (women). Inequalities in mortality from most other causes are not smaller in Spain than elsewhere. Spain also has smaller inequalities in smoking and sedentary lifestyle and this is due to more smoking and physical inactivity in higher educated groups. Conclusion: Overall, the situation with regard to health inequalities does not appear to be more favourable in Spain than in other Western European populations. Smaller inequalities in mortality from cardiovascular disease and cancer in Spain are likely to be related to its later socio-economic modernization. Although these smaller inequalities in mortality seem to be a historical coincidence rather than the outcome of deliberate policies, the Spanish example does suggest that large inequalities in total mortality are
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