10,829 research outputs found

    2GHz MIMO channel model from experimental outdoor data analysis in UMTS

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    The key objective of this work was to obtain a MIMO model for a line of sight (LOS) channel component as well as the covariance matrix for a non-LOS deployment. A maximum likelihood criteria is applied to obtain a LOS spatial signature vector and a NLOS covariance matrix derived from channel measurements taken in the 2 GHz UMTS spectrum for an urban deployment in Bristol (UK). Different user equipment deployments were considered to represent both LOS and NLOS, as well as static and dynamic (motion) situations. The parameters of interest were estimated from these data and the fitness model was satisfactorily evaluated in all cases. Further, the Kronecker product between transmitter and receiver matrices was evaluated in order to simplify the model, for both, LOS and NLOS cases, including polarization diversity cases.The key objective of this work was to obtain a MIMO model for a line of sight (LOS) channel component as well as the covariance matrix for a non-LOS deployment. A maximum likelihood criteria is applied to obtain a LOS spatial signature vector and a NLOS covariance matrix derived from channel measurements taken in the 2 GHz UMTS spectrum for an urban deployment in Bristol (UK). Different user equipment deployments were considered to represent both LOS and NLOS, as well as static and dynamic (motion) situations. The parameters of interest were estimated from these data and the fitness model was satisfactorily evaluated in all cases. Further, the Kronecker product between transmitter and receiver matrices was evaluated in order to simplify the model, for both, LOS and NLOS cases, including polarization diversity cases

    Breaking Tri-bimaximal Mixing and Large θ13\theta_{13}

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    The long baseline neutrino experiment, T2K, and the reactor experiment, Double Chooz will soon present new data. If we expect sinθ13\sin\theta_{13} to be 0.1-0.2, which is close to the present experimental upper bound, we should not persist in the paradigm of the tri-bimaximal mixing. We discuss breaking the tri-bimaximal mixing by adding a simple mass matrix, which could be derived from some non-Abelian discrete symmetries. It is found that sinθ13=0.10.2\sin\theta_{13}=0.1-0.2 is expected in our model independent analysis of the generalized mass matrix for the normal or inverted hierarchical neutrino mass spectrum. On the other hand, sin2θ23\sin^2\theta_{23} and sin2θ12\sin^2\theta_{12} are expected to be not far from 1/2 and 1/3, respectively. As a typical example, we also discuss the A4A_4 flavor model with the 1 and 1' flavons, which break the tri-bimaximal mixing considerably. In this modified version of the Altarelli and Feruglio model, sinθ13\sin\theta_{13} is predicted to be around 0.15 in the case of the normal hierarchical neutrino masses m3m2,m1m_3\gg m_2, m_1, and 0.2 in the case of the inverted hierarchy m3m2,m1m_3\ll m_2, m_1. The form of the neutrino mass matrix looks rather interesting --- it is suggestive of other discrete symmetries as well.Comment: 10 pages, 12 figures, final versio

    Catechol estrogens stimulate insulin secretion in pancreatic β-cells via activation of the transient receptor potential A1 (TRPA1) channel

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    Estrogen hormones play an important role in controlling glucose homeostasis and pancreatic β-cell function. Despite the significance of estrogen hormones for regulation of glucose metabolism, little is known about the roles of endogenous estrogen metabolites in modulating pancreatic β-cell function. In this study, we evaluated the effects of major natural estrogen metabolites, catechol estrogens, on insulin secretion in pancreatic β-cells. We show that catechol estrogens, hydroxylated at positions C2 and C4 of the steroid A ring, rapidly potentiated glucose-induced insulin secretion via a nongenomic mechanism. 2-Hydroxyestrone, the most abundant endogenous estrogen metabolite, was more efficacious in stimulating insulin secretion than any other tested catechol estrogens. In insulin-secreting cells, catechol estrogens produced rapid activation of calcium influx and elevation in cytosolic free calcium. Catechol estrogens also generated sustained elevations in cytosolic free calcium and evoked inward ion current in HEK293 cells expressing the transient receptor potential A1 (TRPA1) cation channel. Calcium influx and insulin secretion stimulated by estrogen metabolites were dependent on the TRPA1 activity and inhibited with the channel-specific pharmacological antagonists or the siRNA. Our results suggest the role of estrogen metabolism in a direct regulation of TRPA1 activity with potential implications for metabolic diseases

    Evaluación del Proyecto Epikouros de Inserción Sociolaboral de Inmigrantes

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    El proyecto Epikouros del Ayuntamiento de Barcelona representa un modelo de servicio específico de orientación para la inserción sociolaboral dirigido a personas procedentes de la inmigración exterior y con situación socioeconómica deficitaria. El proyecto pretendía responder a las necesidad peculiares que estas personas tienen en su proceso de inserción sociolaboral en la ciudad de Barcelona. Su finalidad fue acercar a los colectivos, asociaciones y personas inmigrantes los distintos servicios de inserción sociolaboral normalizados del Ayuntamiento de Barcelona, a la vez que facilitar la coordinación y adaptación de éstos a las necesidades diferenciales que tiene esta población. El proyecto atendió a un total de 235 personas inmigrantes

    Diversidad y Multiculturalidad

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    Esta ponencia se enmarca en la línea de anteriores trabajos nuestros, en los que se ha intentado ofrecer el panorama general de la investigación llevada a cabo en el campo de la diferenciación educativa, y, más en concreto de la educación intercultural. En «Diseños y metodologías de investigación desde la perspectiva de la educación intercultural » (Bartolomé, 1992), tras una breve clarificación de términos asociados a la educación multicultural, analizábamos los principales métodos de investigación y campos de estudio que se habían desarrollado a lo largo de este siglo en el ámbito mundial. En «Modelos de investigación en la intervención educativa diferencial» (Bartolomé, Cabrera, F., Espín, J., Marín, M.A., Del Rincón, D. y Rodríguez, M., 1993) nos centrábamos en un marco más amplio, intentando abordar el estado de la investigación en ese momento en cada una de las áreas temáticas, al tiempo que profundizábamos en los principales problemas metodológicos hallados

    Analysis of University Postgraduate Nursing Education in Spain

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    Background: The nursing education program framework in Spain has recently been adapted and modified. This study aimed to analyze university postgraduate master'slevel nursing education during the past 21 years in Spain in terms of educational supply and demand. Method: A retrospective, longitudinal, descriptive, and observational design was used. The educational offerings at 15 university nursing schools in Spain were examined. The target population was 7,871 registered and licensed nurses who had completed postgraduate education. Results: Among the 211 programs offered, public universities' educational offerings focused on two areas public health and emergency care whereas most courses in private universities were in surgery. Regarding demand, 1,235 nurses were enrolled. The most frequently requested educational areas were surgery, emergency and urgent care, and public health. Conclusion: Although the postgraduate nursing education situation has changed, supply and demand for this type of education in Spain are well balanced at both public and private universities

    Homozygosity Mapping and Genetic Analysis of Autosomal Recessive Retinal Dystrophies in 144 Consanguineous Pakistani Families.

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    PurposeThe Pakistan Punjab population has been a rich source for identifying genes causing or contributing to autosomal recessive retinal degenerations (arRD). This study was carried out to delineate the genetic architecture of arRD in the Pakistani population.MethodsThe genetic origin of arRD in a total of 144 families selected only for having consanguineous marriages and multiple members affected with arRD was examined. Of these, causative mutations had been identified in 62 families while only the locus had been identified for an additional 15. The remaining 67 families were subjected to homozygosity exclusion mapping by screening of closely flanking microsatellite markers at 180 known candidate genes/loci followed by sequencing of the candidate gene for pathogenic changes.ResultsOf these 67 families subjected to homozygosity mapping, 38 showed homozygosity for at least one of the 180 regions, and sequencing of the corresponding genes showed homozygous cosegregating mutations in 27 families. Overall, mutations were detected in approximately 61.8 % (89/144) of arRD families tested, with another 10.4% (15/144) being mapped to a locus but without a gene identified.ConclusionsThese results suggest the involvement of unmapped novel genes in the remaining 27.8% (40/144) of families. In addition, this study demonstrates that homozygosity mapping remains a powerful tool for identifying the genetic defect underlying genetically heterogeneous arRD disorders in consanguineous marriages for both research and clinical applications

    Protocol for studying cough frequency in people with pulmonary tuberculosis.

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    INTRODUCTION: Cough is a key symptom of tuberculosis (TB) as well as the main cause of transmission. However, a recent literature review found that cough frequency (number of coughs per hour) in patients with TB has only been studied once, in 1969. The main aim of this study is to describe cough frequency patterns before and after the start of TB treatment and to determine baseline factors that affect cough frequency in these patients. Secondarily, we will evaluate the correlation between cough frequency and TB microbiological resolution. METHODS: This study will select participants with culture confirmed TB from 2 tertiary hospitals in Lima, Peru. We estimated that a sample size of 107 patients was sufficient to detect clinically significant changes in cough frequency. Participants will initially be evaluated through questionnaires, radiology, microscopic observation drug susceptibility broth TB-culture, auramine smear microscopy and cough recordings. This cohort will be followed for the initial 60 days of anti-TB treatment, and throughout the study several microbiological samples as well as 24 h recordings will be collected. We will describe the variability of cough episodes and determine its association with baseline laboratory parameters of pulmonary TB. In addition, we will analyse the reduction of cough frequency in predicting TB cure, adjusted for potential confounders. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the ethics committees at each participating hospital in Lima, Peru, Asociación Benéfica PRISMA in Lima, Peru, the Universidad Peruana Cayetano Heredia in Lima, Peru and Johns Hopkins University in Baltimore, USA. We aim to publish and disseminate our findings in peer-reviewed journals. We also expect to create and maintain an online repository for TB cough sounds as well as the statistical analysis employed

    Environment of the submillimeter-bright massive starburst HFLS3 at zz\sim6.34

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    We describe the search for Lyman-break galaxies (LBGs) near the sub-millimeter bright starburst galaxy HFLS3 at zz==6.34 and a study on the environment of this massive galaxy during the end of reionization.We performed two independent selections of LBGs on images obtained with the \textit{Gran Telescopio Canarias} (GTC) and the \textit{Hubble Space Telescope} (HST) by combining non-detections in bands blueward of the Lyman-break and color selection. A total of 10 objects fulfilling the LBG selection criteria at zz>>5.5 were selected over the 4.54 and 55.5 arcmin2^2 covered by our HST and GTC images, respectively. The photometric redshift, UV luminosity, and the star-formation rate of these sources were estimated with models of their spectral energy distribution. These zz\sim6 candidates have physical properties and number densities in agreement with previous results. The UV luminosity function at zz\sim6 and a Voronoi tessellation analysis of this field shows no strong evidence for an overdensity of relatively bright objects (mF105W_{F105W}<<25.9) associated with \textit{HFLS3}. However, the over-density parameter deduced from this field and the surface density of objects can not excluded definitively the LBG over-density hypothesis. Moreover we identified three faint objects at less than three arcseconds from \textit{HFLS3} with color consistent with those expected for zz\sim6 galaxies. Deeper data are needed to confirm their redshifts and to study their association with \textit{HFLS3} and the galaxy merger that may be responsible for the massive starburst.Comment: 14 pages, 12 figures, accepted for publication in Ap

    Maíz de alto contenido proteínico (Zea mays l.) en hogares rurales marginados del estado de Puebla

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    El déficit en ingesta diaria de proteínas y calorías registrado en la población infantil mexicana, se muestra de modo extremo en áreas rurales. El déficit se agudiza por la problemática económica y sanitaria actual, lo que se constituye en un problema alimentario de naturaleza nacional. En este trabajo se estudió el nivel de aceptabilidad del maíz de alta calidad proteínica (ACP) con el cálculo de un índice de aceptabilidad, con información de 78 productores, del sur del estado de Puebla, que participan en un programa de la SDR, caracterizados por IDH bajo y alto índice de desnutrición. Se aplicó un cuestionario de 51 preguntas a una muestra por muestreo aleatorio simple, con grado de confiabilidad de 95%. Se encontró que la semilla del maíz ACP se distribuye con sus atributos proteínicos, pero con una deficiente transferencia de tecnología; con índice de aceptabilidad del 60%, que muestra buena aceptación para ser sembrado por los productores. Lo siembran uno, dos o tres años, valorando sus circunstancias para repetirlo en ciclos siguientes, ignorando sus propiedades proteínicas. El consumo, del maíz ACP se incorpora al forraje para animales de traspatio y esporádicamente en la dieta de la familia
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