446 research outputs found

    Slow light in molecular aggregates nanofilms

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    We study slow light performance of molecular aggregates arranged in nanofilms by means of coherent population oscillations (CPO). The molecular cooperative behavior inside the aggregate enhances the delay of input signals in the GHz range in comparison with other CPO-based devices. Moreover, the problem of residual absorption present in CPO processes, is removed. We also propose an optical switch between different delays by exploiting the optical bistability of these aggregates.Comment: 4 pages, 4 figure

    Ensamblado ad hoc de clasificadores para la detección de cáncer de mama usando Scikit-learn

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    En el presente, el cáncer de mama es uno de los cánceres más frecuentes y es la segunda causa de muerte en mujeres en todo el mundo. Asimismo, cada vez es más difícil ignorar el constante e intenso aumento de la importancia de los enfoques de minería de datos en los diagnósticos médicos. En este sentido, central a toda la disciplina de la minería de datos, encontramos la clasificación como la tarea preponderante en el proceso de toma de decisiones para los médicos. A día de hoy, una gran cantidad de clasificadores se han propuesto en la literatura. Sin embargo, teniendo en cuenta la cantidad de personas afectadas por el cáncer, merece la pena seguir desarrollando técnicas que puedan contribuir en mejores formas de diagnóstico. En lo que a este estudio concierne, se ha considerado introducir un ensamblado de clasificadores, propuesto en razón al balance entre sus factores individuales de sesgo y varianza. Demostrando la correctitud de la metodología adoptada para la conjunción ad hoc de los clasificadores, los resultados empíricos de este estudio proporcionan evidencia de una mejor clasificación de los tumores como maligno o benigno, en cuanto a precisión se refiere.XVI Workshop Bases de Datos y Minería de Datos.Red de Universidades con Carreras en Informátic

    Ensamblado ad hoc de clasificadores para la detección de cáncer de mama usando Scikit-learn

    Get PDF
    En el presente, el cáncer de mama es uno de los cánceres más frecuentes y es la segunda causa de muerte en mujeres en todo el mundo. Asimismo, cada vez es más difícil ignorar el constante e intenso aumento de la importancia de los enfoques de minería de datos en los diagnósticos médicos. En este sentido, central a toda la disciplina de la minería de datos, encontramos la clasificación como la tarea preponderante en el proceso de toma de decisiones para los médicos. A día de hoy, una gran cantidad de clasificadores se han propuesto en la literatura. Sin embargo, teniendo en cuenta la cantidad de personas afectadas por el cáncer, merece la pena seguir desarrollando técnicas que puedan contribuir en mejores formas de diagnóstico. En lo que a este estudio concierne, se ha considerado introducir un ensamblado de clasificadores, propuesto en razón al balance entre sus factores individuales de sesgo y varianza. Demostrando la correctitud de la metodología adoptada para la conjunción ad hoc de los clasificadores, los resultados empíricos de este estudio proporcionan evidencia de una mejor clasificación de los tumores como maligno o benigno, en cuanto a precisión se refiere.XVI Workshop Bases de Datos y Minería de Datos.Red de Universidades con Carreras en Informátic

    Educational innovation with the use of gamification and robotics

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    Motivar e interesar al alumnado en el estudio de las asignaturas STEM (en inglés Science, Technology, Engineering & Maths) es un nuevo reto para la Unión Europea. Se presenta un proyecto de investigación H2020 que se está desarrollando actualmente en cinco países europeos (Finlandia, Bielorrusia, Grecia, Alemania y España) y que pretende promover el gusto por el estudio de estas asignaturas entre el alumnado de 10 a 18 años. El proyecto tiene una duración de 3 años y para establecer los principios pedagógicos se ha llevado a cabo un estudio de corte eminentemente cualitativo a través del análisis de grupos focales, formados por alumnado, profesorado, padres y representantes de empresas del sector. Se dan a conocer las líneas generales del proyecto, así como la metodología empleada y las actuaciones llevadas a cabo a través de grupos focales y entrevistas a expertos. Se está desarrollando una investigación para conocer las preferencias de los estudiantes al abordar las materias STEM del currículum. Los resultados, hasta el momento, muestran la necesidad del estudiante de sentir alegría por el estudio y el aprendizaje.Motivating and interesting students in the study of STEM subjects (in English Science, Technology, Engineering & Maths) is a new challenge for the European Union. It presents a research project H2020 that is currently being developed in five European countries (Finland, Belarus, Greece, Germany and Spain) and that aims to promote a taste for the study of these subjects among students from 10 to 18 years. The project has a duration of 3 years and to establish the pedagogical principles, an eminently qualitative study has been carried out through the analysis of focus groups, formed by students, teachers, parents and representatives of companies in the sector. The general lines of the project are presented, as well as the methodology used and the actions carried out through focus groups and interviews with experts. An investigation is being developed to know the preferences of the students when approaching the STEM subjects of the curriculum. The results, so far, show the student’s need to feel joy of learning.peerReviewe

    Vegetative growth response of beets and lettuce to stored human urine

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    ArticleIn this work, we present the experimental results of the effect of stored human urine (SHU) on the growth of beets (Beta vulgaris L) and lettuce (Lactuca sativaL). We apply different amounts of SHU according to the recommended dose of nitrogen, considering soil from farmland and vermiculite as substrates. The last allows us to determine with high precision the isolated effect of SHU over the vegetative development of beet plants, without considering other nutrients present in common soils. Experimental results demonstrate that the application of SHU has no significant effects on lettuce vegetative growth under our soil conditions. In contrast, SHU can be used successfully as a fertilizer of beets. The optimum dose was found at 120kgN ha-1and resulted in average dry weight of 125g. However, if the dose exceeds the optimum levels, the growth of the plant is inhibited. Beets fertilized with SHU does not pose any hygienic risk for human consumption. Our findings represent a promising alternative to propose expanding the use of SHU as fertilizer in medium-sized greenhouses and to provide benefits to families in rural areas, with little or no available water supplies

    Tunable slow- and fast-light devices based on molecular-aggregate nanofilms

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    We study the tunability of nanofilms composed of linear molecular aggregates for slow- and fast-light performance. In order to describe a wide range of intensity field regimes, we consider a two-exciton model for the molecular aggregate where exciton creation or annihilation may occur. Our simulations show fractional delays and advancements of the order of those found in longer propagating media. This nanometric device presents two functionalities: (i) it allows the existence of slow or fast light in a different bandwidth of pulsed signals and (ii) such dual performance can be tuned by a small perturbation of the input signal amplitude for a fixed pulse temporal width. Both effects are tested under the usual presence of disorder in these molecular systems. This study concludes that a molecular-aggregate nanofilm presents a wide control of group velocity in the GHz and THz bandwidths

    Diseño de filtros corrugados mediante la técnica de enjambre de partículas

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    En este artículo se presenta la experiencia en la aplicación de la técnica de optimización de enjambre de partículas o PSO (Particle Swarm Optimization) al diseño de filtros corrugados en guía de onda. Los resultados obtenidos indican que esta técnica permite realizar diseños que se adaptan a una máscara de filtrado predeterminada con una alta convergencia hacia la solución óptima

    Analysis of noise temperature sensitivity for the design of a broadband thermal noise primary standard

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    A broadband primary standard for thermal noise measurements is presented and its thermal and electromagnetic behaviour is analysed by means of a novel hybrid analytical?numerical simulation methodology. The standard consists of a broadband termination connected to a 3.5mm coaxial airline partially immersed in liquid nitrogen and is designed in order to obtain a low reflectivity and a low uncertainty in the noise temperature. A detailed sensitivity analysis is made in order to highlight the critical characteristics that mostly affect the uncertainty in the noise temperature, and also to determine the manufacturing and operation tolerances for a proper performance in the range 10MHz to 26.5 GHz. Aspects such as the thermal bead design, the level of liquid nitrogen or the uncertainties associated with the temperatures, the physical properties of the materials in the standard and the simulation techniques are discussed

    Genomic characterization and seroprevalence studies on alphaviruses in Uruguay

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    Alphaviruses (Togaviridae) are arboviruses frequently associated with emerging infectious diseases. In this study, we aimed to investigate the presence of alphaviruses in Uruguay by detecting the viral genome in mosquitoes and neutralizing antibodies in equines. A total of 3,575 mosquitoes were analyzed for alphavirus genome detection. Serologic studies were performed on 425 horse sera by plaque reduction neutralization test (PRNT80) against Venezuelan equine encephalitis virus (VEEV) subtype IAB, Pixuna virus (PIXV), Rio Negro virus (RNV), western equine encephalitis virus (WEEV), and Madariaga virus (MADV). Mosquitoes belonging to six genera were captured and 82.9% were identified as Culex pipiens. Two Cx. pipiens pools collected in Fray Bentos and Las Toscas localities were alphavirus positive, and phylogenetic analyses showed that the sequences grouped into two different clusters: the lineage I of eastern equine encephalitis virus and RNV (VEEV complex), respectively. Plaque reduction neutralization test assays showed antibodies against strains of the VEEV complex, MADV, and WEEV. Rio Negro virus was the most geographically widespread virus, showing higher seroprevalences (up to 20%). Seroprevalences against VEEV IAB ranged between 4.6% and 13%; antibodies against PIXV, WEEV, and MADV were less frequent (3–4%). In conclusion, RNV exhibited the highest seroprevalence in horses, a wide geographical distribution, and viral genome was detected in Cx. pipiens mosquitoes. Madariaga virus had a low seroprevalence in equines, but an epizootic lineage typical of North America was detected in Cx. pipiens mosquitoes. Taken together, our results show that alphaviruses are present in Uruguay with variable occurrence and geographical distribution being a potential threat for human and equine health

    Role of the employment status and education of mothers in the prevalence of intestinal parasitic infections in Mexican rural schoolchildren

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    <p><b>Background:</b> Intestinal parasitic infections are a public health problem in developing countries such as Mexico. As a result, two governmental programmes have been implemented: a) "National Deworming Campaign" and b) "Opportunities" aimed at maternal care. However, both programmes are developed separately and their impact is still unknown. We independently investigated whether a variety of socio-economic factors, including maternal education and employment levels, were associated with intestinal parasite infection in rural school children.</p> <p><b>Methods:</b> This cross-sectional study was conducted in 12 rural communities in two Mexican states. The study sites and populations were selected on the basis of the following traits: a) presence of activities by the national administration of albendazole, b) high rates of intestinal parasitism, c) little access to medical examination, and d) a population having less than 2,500 inhabitants. A total of 507 schoolchildren (mean age 8.2 years) were recruited and 1,521 stool samples collected (3 per child). Socio-economic information was obtained by an oral questionnaire. Regression modelling was used to determine the association of socio-economic indicators and intestinal parasitism.</p> <p><b>Results:</b> More than half of the schoolchildren showed poliparasitism (52%) and protozoan infections (65%). The prevalence of helminth infections was higher in children from Oaxaca (53%) than in those from Sinaloa (33%) (p < 0.0001). Giardia duodenalis and Hymenolepis nana showed a high prevalence in both states. Ascaris lumbricoides, Trichuris trichiura and Entamoeba hystolitica/dispar showed low prevalence. Children from lower-income families and with unemployed and less educated mothers showed higher risk of intestinal parasitism (odds ratio (OR) 6.0, 95% confidence interval (CI) 1.6–22.6; OR 4.5, 95% CI 2.5–8.2; OR 3.3, 95% CI 1.5–7.4 respectively). Defecation in open areas was also a high risk factor for infection (OR 2.4, 95% CI 2.0–3.0).</p> <p><b>Conclusion:</b> Intestinal parasitism remains an important public health problem in Sinaloa (north-western Mexico) and Oaxaca (south-eastern Mexico). Lower income, defecation in open areas, employment status and a lower education level of mothers were the significant factors related to these infections. We conclude that mothers should be involved in health initiatives to control intestinal parasitism in Mexico.</p&gt
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