23 research outputs found

    A Collaborative Filtering Probabilistic Approach for Recommendation to Large Homogeneous and Automatically Detected Groups

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    In the collaborative filtering recommender systems (CFRS) field, recommendation to group of users is mainly focused on stablished, occasional or random groups. These groups have a little number of users: relatives, friends, colleagues, etc. Our proposal deals with large numbers of automatically detected groups. Marketing and electronic commerce are typical targets of large homogenous groups. Large groups present a major difficulty in terms of automatically achieving homogeneity, equilibrated size and accurate recommendations. We provide a method that combines diverse machine learning algorithms in an original way: homogeneous groups are detected by means of a clustering based on hidden factors instead of ratings. Predictions are made using a virtual user model, and virtual users are obtained by performing a hidden factors aggregation. Additionally, this paper selects the most appropriate dimensionality reduction for the explained RS aim. We conduct a set of experiments to catch the maximum cumulative deviation of the ratings information. Results show an improvement on recommendations made to large homogeneous groups. It is also shown the desirability of designing specific methods and algorithms to deal with automatically detected groups

    Regression of cardiomyocyte hypertrophy in SHR following chronic inhibition of the Na+/H+ exchanger

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    Objective: Experiments were performed to examine the effect of chronic inhibition of the Na+/H+ exchanger isoform-1 (NHE-1) on cardiac hypertrophy of spontaneously hypertensive rats (SHR). Methods: SHR were orally treated during 1 month with two different doses (0.3 and 3.0 mg/kg/day) of the NHE-1 inhibitor, cariporide, or nifedipine (10.0 mg/kg/day). Results: The two doses of cariporide did not differ in their effects after 1 month of treatment, since both induced a slight decrease in systolic blood pressure (SBP) of ∼6 mmHg and regression of the heart weight to body weight ratio (mg/g) from 3.28±0.05 to 3.04±0.05 (0.3 mg) and 2.99±0.10 (3.0 mg, P<0.05). Nifedipine, given for the same period, produced similar reduction in the hypertrophy index (3.03±0.05), but with a much greater decrease in arterial pressure (35.6±7.4 mmHg). Chronic treatment with cariporide induced a complete regression of the augmented cross sectional area of left ventricular myocytes without significant changes in collagen content, serum procollagen 1 propeptide levels or myocardial distensibility. Conclusions: NHE inhibition represents a novel approach to induce regression of pathological hypertrophy of the heart. The finding can be rationalized mechanistically by previous in vitro studies suggesting a role of the NHE in the development of myocardial hypertrophy.Facultad de Ciencias MédicasFacultad de Ciencias VeterinariasCentro de Investigaciones Cardiovasculare

    Regression of hypertensive myocardial fibrosis by Na+/H+ exchange inhibition

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    We have recently reported that the inhibition of the Na+/H+ exchanger (NHE) during 1 month in spontaneously hypertensive rats (SHR) is followed by regression of cardiomyocyte hypertrophy but not of myocardial fibrosis. The aim of this study was to evaluate whether a treatment of longer duration could reduce myocardial fibrosis and stiffness. SHR received 3.0 mg/kg per day of the specific NHE-1 inhibitor cariporide; the effect on cardiomyocyte cross-sectional area, myocardial collagen volume fraction, collagen synthesis, and myocardial stiffness (length-tension relation in left papillary muscles) was evaluated at several time points (after 1, 2, or 3 months). A slight decrease of ≈5 mm Hg in systolic blood pressure was observed after 1 month of treatment with no further changes. After 2 and 3 months of treatment, the size of cardiomyocytes remained within normal values and myocardial fibrosis progressively decreased to normal level. Accordingly, myocardial stiffness and the serum levels of the carboxyterminal propeptide of procollagen type I, a marker of collagen type I synthesis, were normalized after 3 months. Left ventricular weight decreased from 910±43 (in untreated SHR) to 781±21 mg (treated SHR) after 3 months of treatment. No difference in body weight between treated and untreated SHR was observed after this period of treatment. The present data allow us to conclude that in the SHR the administration of an NHE-1 inhibitor for 2 or 3 months leads to the normalization of collagen type I synthesis, myocardial collagen volume fraction, and stiffness.Facultad de Ciencias MédicasFacultad de Ciencias Veterinaria

    Regression of cardiomyocyte hypertrophy in SHR following chronic inhibition of the Na+/H+ exchanger

    Get PDF
    Objective: Experiments were performed to examine the effect of chronic inhibition of the Na+/H+ exchanger isoform-1 (NHE-1) on cardiac hypertrophy of spontaneously hypertensive rats (SHR). Methods: SHR were orally treated during 1 month with two different doses (0.3 and 3.0 mg/kg/day) of the NHE-1 inhibitor, cariporide, or nifedipine (10.0 mg/kg/day). Results: The two doses of cariporide did not differ in their effects after 1 month of treatment, since both induced a slight decrease in systolic blood pressure (SBP) of ∼6 mmHg and regression of the heart weight to body weight ratio (mg/g) from 3.28±0.05 to 3.04±0.05 (0.3 mg) and 2.99±0.10 (3.0 mg, P<0.05). Nifedipine, given for the same period, produced similar reduction in the hypertrophy index (3.03±0.05), but with a much greater decrease in arterial pressure (35.6±7.4 mmHg). Chronic treatment with cariporide induced a complete regression of the augmented cross sectional area of left ventricular myocytes without significant changes in collagen content, serum procollagen 1 propeptide levels or myocardial distensibility. Conclusions: NHE inhibition represents a novel approach to induce regression of pathological hypertrophy of the heart. The finding can be rationalized mechanistically by previous in vitro studies suggesting a role of the NHE in the development of myocardial hypertrophy.Facultad de Ciencias MédicasFacultad de Ciencias VeterinariasCentro de Investigaciones Cardiovasculare

    Regression of hypertensive myocardial fibrosis by Na+/H+ exchange inhibition

    Get PDF
    We have recently reported that the inhibition of the Na+/H+ exchanger (NHE) during 1 month in spontaneously hypertensive rats (SHR) is followed by regression of cardiomyocyte hypertrophy but not of myocardial fibrosis. The aim of this study was to evaluate whether a treatment of longer duration could reduce myocardial fibrosis and stiffness. SHR received 3.0 mg/kg per day of the specific NHE-1 inhibitor cariporide; the effect on cardiomyocyte cross-sectional area, myocardial collagen volume fraction, collagen synthesis, and myocardial stiffness (length-tension relation in left papillary muscles) was evaluated at several time points (after 1, 2, or 3 months). A slight decrease of ≈5 mm Hg in systolic blood pressure was observed after 1 month of treatment with no further changes. After 2 and 3 months of treatment, the size of cardiomyocytes remained within normal values and myocardial fibrosis progressively decreased to normal level. Accordingly, myocardial stiffness and the serum levels of the carboxyterminal propeptide of procollagen type I, a marker of collagen type I synthesis, were normalized after 3 months. Left ventricular weight decreased from 910±43 (in untreated SHR) to 781±21 mg (treated SHR) after 3 months of treatment. No difference in body weight between treated and untreated SHR was observed after this period of treatment. The present data allow us to conclude that in the SHR the administration of an NHE-1 inhibitor for 2 or 3 months leads to the normalization of collagen type I synthesis, myocardial collagen volume fraction, and stiffness.Facultad de Ciencias MédicasFacultad de Ciencias Veterinaria

    Regression of cardiomyocyte hypertrophy in SHR following chronic inhibition of the Na+/H+ exchanger

    Get PDF
    Objective: Experiments were performed to examine the effect of chronic inhibition of the Na+/H+ exchanger isoform-1 (NHE-1) on cardiac hypertrophy of spontaneously hypertensive rats (SHR). Methods: SHR were orally treated during 1 month with two different doses (0.3 and 3.0 mg/kg/day) of the NHE-1 inhibitor, cariporide, or nifedipine (10.0 mg/kg/day). Results: The two doses of cariporide did not differ in their effects after 1 month of treatment, since both induced a slight decrease in systolic blood pressure (SBP) of ∼6 mmHg and regression of the heart weight to body weight ratio (mg/g) from 3.28±0.05 to 3.04±0.05 (0.3 mg) and 2.99±0.10 (3.0 mg, P<0.05). Nifedipine, given for the same period, produced similar reduction in the hypertrophy index (3.03±0.05), but with a much greater decrease in arterial pressure (35.6±7.4 mmHg). Chronic treatment with cariporide induced a complete regression of the augmented cross sectional area of left ventricular myocytes without significant changes in collagen content, serum procollagen 1 propeptide levels or myocardial distensibility. Conclusions: NHE inhibition represents a novel approach to induce regression of pathological hypertrophy of the heart. The finding can be rationalized mechanistically by previous in vitro studies suggesting a role of the NHE in the development of myocardial hypertrophy.Facultad de Ciencias MédicasFacultad de Ciencias VeterinariasCentro de Investigaciones Cardiovasculare

    Regression of hypertensive myocardial fibrosis by Na+/H+ exchange inhibition

    Get PDF
    We have recently reported that the inhibition of the Na+/H+ exchanger (NHE) during 1 month in spontaneously hypertensive rats (SHR) is followed by regression of cardiomyocyte hypertrophy but not of myocardial fibrosis. The aim of this study was to evaluate whether a treatment of longer duration could reduce myocardial fibrosis and stiffness. SHR received 3.0 mg/kg per day of the specific NHE-1 inhibitor cariporide; the effect on cardiomyocyte cross-sectional area, myocardial collagen volume fraction, collagen synthesis, and myocardial stiffness (length-tension relation in left papillary muscles) was evaluated at several time points (after 1, 2, or 3 months). A slight decrease of ≈5 mm Hg in systolic blood pressure was observed after 1 month of treatment with no further changes. After 2 and 3 months of treatment, the size of cardiomyocytes remained within normal values and myocardial fibrosis progressively decreased to normal level. Accordingly, myocardial stiffness and the serum levels of the carboxyterminal propeptide of procollagen type I, a marker of collagen type I synthesis, were normalized after 3 months. Left ventricular weight decreased from 910±43 (in untreated SHR) to 781±21 mg (treated SHR) after 3 months of treatment. No difference in body weight between treated and untreated SHR was observed after this period of treatment. The present data allow us to conclude that in the SHR the administration of an NHE-1 inhibitor for 2 or 3 months leads to the normalization of collagen type I synthesis, myocardial collagen volume fraction, and stiffness.Facultad de Ciencias MédicasFacultad de Ciencias Veterinaria

    El paisaje rural en la microregión de Honorato Vásquez y Buerán-Burgay

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    Licenciado en Ciencias de la Educación. Especialidad Historia y GeografíaCuenc

    Estudio comparativo de la gestión del desarrollo como libertad, caso de los gobiernos parroquiales rurales: Chorocopte, Ingapirca y Honorato Vásquez, de la Provincia y Cantón Cañar, durante el año 2011

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    La gestión del desarrollo de los gobiernos parroquiales desde el enfoque de libertad política, viene a ser instrumental y constitutiva, conlleva al acceso de toda una serie de libertades fundamentales, nos permite desarrollar nuestras capacidades como seres humanos. Desde sus inicios, los gobiernos parroquiales han pasado procesos históricos hasta convertirse en gobiernos descentralizados con autonomía, política, administrativa y financiera; con competencias exclusivas y concurrentes, bajo un marco jurídico de la Constitución y la COOTAD. El desarrollo local endógeno es sostenible, cuando satisface las necesidades del presente, sin comprometer las capacidades para las futuras generaciones, puedan satisfacer las carencias, compromete a los gobiernos gestionar mediante la participación plural ciudadana, con reconocimiento al otro, la alteridad, sin descuidar lo invisible de nuestras economías producto del neoliberalismo. Los enfoques de la libertad y el buen vivir, se amalgaman por la cosmovisión andina; a nivel local nos permite reconstruir, reivindicar, revitalizar el proyecto andino campesino, indígena y del pueblo, propuesta desde hace años, debiendo los gobiernos construir sus modelos del desarrollo en base a las libertades como medios: las libertades políticas con espacios a las críticas democráticas, los servicios económicos, las oportunidades sociales, las garantías de transparencia y la seguridad protectora, en forma proporcional y complementaria en igualdad de género. Para obtener el ejercicio de la libertad, debemos implementar políticas públicas en inversiones sociales para llegar a la felicidad, del sentir, pensar y vivir.Magíster en Sociología y Desarrollo. Mención en Ciencias PolíticasCuenc
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