880 research outputs found

    GPCALMA: a Grid Approach to Mammographic Screening

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    The next generation of High Energy Physics experiments requires a GRID approach to a distributed computing system and the associated data management: the key concept is the "Virtual Organisation" (VO), a group of geographycally distributed users with a common goal and the will to share their resources. A similar approach is being applied to a group of Hospitals which joined the GPCALMA project (Grid Platform for Computer Assisted Library for MAmmography), which will allow common screening programs for early diagnosis of breast and, in the future, lung cancer. HEP techniques come into play in writing the application code, which makes use of neural networks for the image analysis and shows performances similar to radiologists in the diagnosis. GRID technologies will allow remote image analysis and interactive online diagnosis, with a relevant reduction of the delays presently associated to screening programs.Comment: 4 pages, 3 figures; to appear in the Proceedings of Frontier Detectors For Frontier Physics, 9th Pisa Meeting on Advanced Detectors, 25-31 May 2003, La Biodola, Isola d'Elba, Ital

    A technological acceptance of e-learning tools used in practical and laboratory teaching, according to the European higher education area

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    The application of scientific tools to analyse the use of Internet-based e-learning tools in academic settings is in general an ignored area. E-learning tools are actually an emergent topic as a result of the new ideas introduced by the European Higher Education Area. Lifelong learning, or the promotion of student initiative, is the new paradigm of a learner-centred education. In this context, e-learning tools can represent an effective way of supporting this new trend in education. Assuming the premise that successful use of these web-based tools depends primarily on a user’s behaviour, the objective of this research is to examine the technology acceptance model (TAM) of web-based elearning tools used in practical and laboratory teaching. The research hypotheses derived from this model have empirically been validated using the responses to a survey on e-learning usage among 220 users. These responses have been examined through partial least square. The obtained results strongly support the extended TAM in predicting a student’s intention to use e-learning and define a set of external variables with a significant influence in the original TAM variables. Surprisingly, perceived ease of use did not posit a significant impact on student attitude or intention towards e-learning tool usage. Therefore, early evaluation of e-learning material is considered essential to providing a framework for further improvements of the too

    A Computer Aided Detection system for mammographic images implemented on a GRID infrastructure

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    The use of an automatic system for the analysis of mammographic images has proven to be very useful to radiologists in the investigation of breast cancer, especially in the framework of mammographic-screening programs. A breast neoplasia is often marked by the presence of microcalcification clusters and massive lesions in the mammogram: hence the need for tools able to recognize such lesions at an early stage. In the framework of the GPCALMA (GRID Platform for Computer Assisted Library for MAmmography) project, the co-working of italian physicists and radiologists built a large distributed database of digitized mammographic images (about 5500 images corresponding to 1650 patients) and developed a CAD (Computer Aided Detection) system, able to make an automatic search of massive lesions and microcalcification clusters. The CAD is implemented in the GPCALMA integrated station, which can be used also for digitization, as archive and to perform statistical analyses. Some GPCALMA integrated stations have already been implemented and are currently on clinical trial in some italian hospitals. The emerging GRID technology can been used to connect the GPCALMA integrated stations operating in different medical centers. The GRID approach will support an effective tele- and co-working between radiologists, cancer specialists and epidemiology experts by allowing remote image analysis and interactive online diagnosis.Comment: 5 pages, 5 figures, to appear in the Proceedings of the 13th IEEE-NPSS Real Time Conference 2003, Montreal, Canada, May 18-23 200

    A dedicated electric oven for characterization of thermoresistive polymer nanocomposites

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    AbstractThe construction, characterization and control of an electric oven dedicated to the study of thermoresistive polymer nanocomposites is presented. The oven is designed with a heating plate capable of reaching 300°C with a resolution of 0.3°C and an area of uniform temperature of 3.8cm×2.5cm. The temperature is regulated by means of a discrete proportional–integral–derivative controller. A heat transfer model comprising three coupled non-linear differential equations is proposed to predict the thermal profiles of the oven during heating and cooling, which are experimentally verified. The oven is used for thermoresistive characterization of polymer nanocomposites manufactured from a polysulfone polymer and multiwall carbon nanotubes

    Tectonic fabrics vs. mineralogical artifacts in AMS analysis: A case study of the Western Morocco extensional Triassic basins

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    New magnetic fabric data from 48 sites in Upper Triassic red beds from the Argana, Asni and Tizi n''Tichka areas in the western High Atlas, in combination with rock magnetic analyses, SEM observations and qualitative chemical analyses, reveal that mineralization processes can affect the primary (extensional) or secondary (post-depositional) magnetic fabrics. Twenty out of the 48 analyzed sites show tectonic-related fabrics consistent with the rifting stage (primary). Their orientation suggests that the extensional Atlasic (for the Asni area) and Atlantic (for Argana area) distinct directions prevailing during Liassic times are already present in the Upper Triassic sediments. The other 28 sites show axes switching (including different possibilities, kmax-kmin or kint-kmin), indicating their secondary development related to mineralogical changes after deposition. However, orientation of magnetic susceptibility axes (without considering their relative value) is consistent with the main directions obtained for the rifting stage. This magnetic fabric study also suggests that (i) extension had a small transtensional component and (ii) there is a limited influence of compressional inversion tectonics

    Targeting specific nutrient deficiencies in proteinrestricted diets: some practical facts in PKU dietary management

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    Among aminoacidopathies, phenylketonuria (PKU) is the most prevalent one. Early diagnosis in the neonatal period with a prompt nutritional therapy (low natural-protein and phenylalanine diet, supplemented with phenylalanine-free amino acid mixtures and special low-protein foods) remains the mainstay of the treatment. Data considering nutrient contents of cooked dishes is lacking. In this study, fourteen dishes specifically prepared for PKU individuals were analysed, regarding the lipid profile and iron and zinc contents. These dishes are poor sources of essential nutrients like Fe, Zn or n-3 fatty acids, reinforcing the need for adequate supplementation to cover individual patients’ needs. This study can contribute to a more accurate adjustment of PKU diets and supplementation in order to prevent eventual nutritional deficiencies. This study contributes to a better understanding of nutrient intake from PKU patients’ meals, showing the need for dietary supplementation

    Estrategia de aprendizaje interactivo para la mejora de la aplicación de la competencia matemática en el entorno de la Farmacia Galénica: Impacto de las primeras acciones de mejora sobre el rendimiento de los alumnos

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    Projecte: 2015PID-UB/039Se presentan los avances del Grupo de Innovación Docente de Tecnología Farmacéutica (GIDTF) en su línea de actuación relativa a la implementación de una estrategia de aprendizaje interactivo en los seminarios de problemas de Farmacia Galénica para el desarrollo de la competencia matemática en este ámbito por los estudiantes del grado de Farmacia. Las acciones realizadas incluyen actividades individuales de autoevaluación para detectar el nivel de capacidad resolutiva a modo de diagnóstico y otras grupales para fomentar un aprendizaje entre iguales. Se confirma que las acciones de mejora en la estrategia de enseñanza-aprendizaje implantada en curso 2015-16, respecto al desarrollo de la competencia matemática en Farmacia Galénica, han dado los resultados benéficos esperados.Universidad de Barcelon

    Predicting potential distribution and identifying priority areas for conservation of the Yellow-tailed Woolly Monkey (Lagothrix flavicauda) in Peru

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    Species distribution models (SDMs) provide conservationist with spatial distributions estimations of priority species. Lagothrix flavicauda (Humboldt, 1812), commonly known as the Yellow-tailed Woolly Monkey, is one of the largest primates in the New World. This species is endemic to the montane forests of northern Peru, in the departments of Amazonas, San Martín, Huánuco, Junín, La Libertad, and Loreto at elevation from1,000 to 2,800 m. It is classified as “Critically Endangered” (CR) by the International Union for Conservation of Nature (IUCN) as well as by Peruvian legislation. Furthermore, it is listed in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Research on precise estimates of its potential distribution are scare. Therefore, in this study we modeled the potential distribution area of this species in Peru, the model was generated using the MaxEnt algorithm, along with 80 georeferenced occurrence records and 28 environmental variables. The total distribution (high, moderate, and low) for L. flavicauda is 29,383.3 km2, having 3,480.7 km2 as high potential distribution. In effect, 22.64 % (6,648.49 km2) of the total distribution area of L. flavicauda is found within Natural Protected Areas (NPAs), with the following categories representing the largest areas of distribution: Protected Forests (1,620.41 km2), Regional Conservation Areas (1,976.79 km2), and Private Conservation Areas (1,166.55 km2). After comparing the predicted distribution with the current NPAs system, we identified new priority areas for the conservation of the species. We, therefore, believe that this study will contribute significantly to the conservation of L. flavicauda in Peru

    Identification of Designing Variable of an Elearning Tool

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    En este artículo se muestran, a través de mapas bidimensionales, los resultados procedentes de un proyecto de investigación mediante el cual se han identificado las variables externas a tener en cuenta en el diseño de una herramienta de eLearning para conseguir evaluar, posteriormente, su uso real. La técnica empleada para ello es la "Elaboración de mapas conceptuales". Asimismo, se observa la necesidad de tener en cuenta cómo llevar a cabo la gestión de la herramienta por parte del usuario. Finalmente, se ha analizado la fiabilidad de nuestros mapasIn this paper the results from a research project1 are shown. A scientific technique called "Concept Mapping Process" has been used to identify the external variables to be kept in mind in the design of an eLearning tool, in order to evaluate its true usage later. Results are shown through two-dimensional maps. Another important result is the necessity of designing tools to carry out the management of the tool on the part of the user. Finally, there has been analysed the reliability of our mapsMinisterio de Educación y Ciencia EA2005-017

    Espectroscopia Mössbauer para la caracterización de fases magnéticas en catalizadores del tipo MCM-41 modificados

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    Se prepararon silicatos mesoporosos del tipo MCM-41 modificados con hierro, mediante el método de impregnación húmeda. Se determinaron las distintas especies metálicas formadas según el contenido de hierro. Para esto se debió utilizar la técnica de espectroscopia Mössbauer, la cual nos dio información acerca de las fases presentes y el comportamiento magnético derivado de las mismas.Mesoporous silica MCM-41 modified with iron, by the method of wet impregnation were prepared. Different metallic species formed by the iron content were determined. This was due to using Mössbauer spectroscopy technique, which gave information about the phases present and the magnetic behavior derivative thereof.Instituto de Física La Plat
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