621 research outputs found

    Energy Efficiency of Hybrid-Power HetNets: A Population-like Games Approach

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    In this paper, a distributed control scheme based on population games is proposed. The controller is in charge of dealing with the energy consumption problem in a Heterogeneous Cellular Network (HetNet) powered by hybrid energy sources (grid and renewable energy) while guaranteeing appropriate quality of service (QoS) level at the same time. Unlike the conventional approach in population games, it considers both atomicity and non-anonymity. Simulation results show that the proposed population-games approach reduces grid consumption by up to about 12% compared to the traditional best-signal level association policy.U.S. Air Force Office of Scientific Research FA9550-17-1-0259Ministerio de Cultura y Deporte DPI2016-76493-C3-3-RMinisterio de Economía y Empresa DPI2017-86918-

    Genetic diversity of Colombian sheep by microsatellite markers

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    RESUMEN: In Colombia the sheep production systems are managed under extensive conditions and mainly correspond to peasant production systems so their genetic management has led to increased homozygosity and hence productivity loss. The aim of this study was to determine the genetic diversity in 549 individuals corresponding to 13 sheep breeds in Colombia, using a panel of 11 microsatellite molecular markers. One hundred and fifty seven alleles were found (average of 14.27 alleles/locus), with a range of observed and expected heterozygosity from 0.44 to 0.84 and 0.67 to 0.86, respectively. Thirty-three of 143 Hardy Weinberg tests performed showed significant deviations (p < 0.05) due to a general lack of heterozygous individuals. The Fis ranged from 0.01 in Corriedale to 0.15 for the Persian Black Head breed, suggesting that there are presenting low to moderate levels of inbreeding. Overall, Colombian sheep showed high levels of genetic diversity which is very important for future selection and animalbreeding programs

    Desarrollo de algoritmos de procesamiento de imágenes basados en “operadores de ventana”sobre una FPGA

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    Los Filtros de tipo espacial utilizados en el Procesamiento de Imágenes están fuertemente ligados a los Operadores de Ventana. En este trabajo se presenta el diseño de Módulos específicos para facilitar la implementación de algoritmos Basados en dichos Operadores. Además, se muestra la implementación de varios filtros que requieren de dichos módulos para realizar el Procesamiento de una Imagen. Entre los algoritmos implementados se encuentran los basados en operadores morfológicos, el filtro de mediana y la convolución espacial. Mediante las diferentes aplicaciones se muestra la reusabilidad de los módulos que implementan los Operadores de Ventana en VHDL y la eficiencia con que se pueden implementar varios filtros en una misma FPGA

    Caracterización genética de ovinos criollos colombianos

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    ABSTRACT: indigenous breeds are important for poor farmers because of their natural selection against harsh environments and adaptation to regional conditions. However, inbreeding of indigenous sheep populations has increased in Colombia due to indiscriminate cross-breeding with foreign animals and lack of reproductive controls, with subsequent loss in productivity, which poses a great risk for the conservation of valuable genes. Objective: to determine the genetic diversity in Colombian indigenous sheep by using a panel of 10 microsatellite molecular markers. Methods: blood samples from 362 individuals from 43 farms in 11 Colombian provinces were genotyped and analyzed for a panel of 10 microsatellite markers. Results: a total of 134 alleles were found (13.4 alleles/locus on average) with a range of observed and expected heterozygosity of 0.428 to 0.831 and 0.615 to 0.855, respectively, and 0.742 polymorphic information content (PIC). The average Wright F-statistics (FIS ) of the breeds was 0.107, suggesting moderate levels of inbreeding. Colombian sheep showed a low level of genetic differentiation among breeds (FST = 0.054) and STRUCTURE analysis showed complex patterns of admixture in the breeds. Conclusion: overall, Colombian sheep have high genetic variability, which is very important for future conservation programs and genetic improvement.RESUMEN: las razas animales autóctonas son importantes para los agricultores de escasos recursos a causa de su selección natural contra el duro ambiente y su adaptación a condiciones regionales. Sin embargo en Colombia, debido al cruce indiscriminado con razas foráneas y a la falta de control de la reproducción, ha aumentado la consanguinidad en las poblaciones de ovinos criollos y por lo tanto la pérdida en la productividad, lo que supone un gran riesgo para la conservación de genes valiosos. Objetivo: determinar la diversidad genética en razas criollas de ovinos colombianos utilizando análisis por microsatélites. Métodos: se visitaron 43 granjas localizadas en 11 departamentos del país, en las cuales se tomaron muestras de sangre a 362 individuos. Las muestras fueron genotipadas y analizadas para un panel de 10 marcadores microsatélites. Resultados: un total de 134 alelos fueron encontrados (13,4 alelos/locus en promedio), con un rango de heterocigocidad observada y esperada de 0,428 a 0,831 y 0,615 a 0,855, respectivamente, y un contenido de información polimórfica (PIC) promedio de 0,742. El Wright F-statistics (FIS) promedio de las razas evaluadas fue 0,107, lo cual sugiere que las razas tienen niveles moderados de consanguinidad. Las ovejas colombianas presentaron un bajo grado de diferenciación genética entre las distintas razas (FST = 0,054) y el análisis de STRUCTURE mostro complejos patrones de mezcla en las razas estudiadas. Conclusión: en términos generales, las ovejas colombianas presentan una alta variabilidad genética lo cual es muy importante para futuros programas de conservacion y mejoramiento genetico

    Marine sponges of the genus neopetrosia with anti-inflammatory activity

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    The present study aimed to investigate the anti-inflammatory effect of marine sponges of the genus Neopetrosia which are abundant in the Colombian Caribbean. We obtained three fractions from a total methanolic extract of Neopetrosia rosariensis and proxima. In vivo activity was measured using λ-carrageenan-induced paw edema assay. The in vitro inhibitory effects were evaluated on myeloperoxidase activity (MPO) and nitric oxide (NO), prostaglandin E2 (PGE2), and tumor necrosis factor alpha (TNF- α) production. Total extracts of N. rosariensis and N. proxima (100 mg/Kg) significantly inhibited the paw edema of rats (71.74% and 60.06%, respectively). Dichloromethane and methanol fractions of Neopetrosia sponges reduced MPO activity. Only, dichloromethane fraction of N. rosariensis significantly inhibited NO (66%), PGE2 (30.5%) and TNF-α production (72%). Our results show anti-inflammatory activity in extracts and fractions from species of marine sponges belonging to Neopetrosia genus and open the way for complementary studies to purify and identify active molecules.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Binary Collisions and the Slingshot Effect

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    We derive the equations for the gravity assist manoeuvre in the general 2D case without the constraints of circular planetary orbits or widely different masses as assumed by Broucke, and obtain the slingshot conditions and maximum energy gain for arbitrary mass ratios of two colliding rigid bodies. Using the geometric view developed in an earlier paper by the authors the possible trajectories are computed for both attractive or repulsive interactions yielding a further insight on the slingshot mechanics and its parametrization. The general slingshot manoeuvre for arbitrary masses is explained as a particular case of the possible outcomes of attractive or repulsive binary collisions, and the correlation between asymptotic information and orbital parameters is obtained in general.Comment: 12 pages, 7 figures, accepted for publication Dec'07, Celestial Mechanics and Dynamical Astronom

    Sucrose esters from Physalis peruviana calyces with anti-inflammatory activity

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    Physalis peruviana is a native plant from the South American Andes and is widely used in tra- ditional Colombian medicine of as an anti-inflam- matory medicinal plant, specifically the leaves, calyces, and small stems in poultice form. Pre- vious studies performed by our group on P. pe- ruviana calyces showed potent anti-inflamma- tory activity in an enriched fraction obtained from an ether total extract. The objective of the present study was to obtain and elucidate the ac- tive compounds from this fraction and evaluate their anti-inflammatory activity in vivo and in vi- tro. The enriched fraction of P. peruviana was pu- rified by several chromatographic methods to ob- tain an inseparable mixture of two new sucrose esters named peruviose A (1) and peruviose B (2). Structures of the new compounds were eluci- dated using spectroscopic methods and chemical transformations. The anti-inflammatory activity of the peruvioses mixture was evaluated using λ-carrageenan-induced paw edema in rats and lipopolysaccharide-activated peritoneal macro- phages. Results showed that the peruvioses did not produce side effects on the liver and kidneys and significantly attenuated the inflammation in- duced by λ-carrageenan in a dosage-dependent manner, probably due to an inhibition of nitric oxide and prostaglandin E2, which was demon- strated in vitro. To our knowledge, this is the first report of the presence of sucrose esters in P. pe- ruviana that showed a potent anti-inflammatory effect. These results suggest the potential of su- crose esters from the Physalis genus as a novel natural alternative to treat inflammatory diseases

    Checklist of the freshwater fishes of Colombia

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    Data derived from the literature supplemented by examination of specimens in collections show that 1435 species of native fishes live in the freshwaters of Colombia. These species represent 14 orders and 47 families. Orders with the largest numbers of species in the Colombian continental ichthyofauna are the Characiformes (637 species), Siluriformes (524 species), Perciformes (124 species), and Gymnotiformes (74 species), with the remaining 10 orders having from 1 to 35 species. At the family level, the Characidae has the greatest number of species (399 species), with this followed by the Loricariidae (166 species), Cichlidae (114 species), Pimelodidae (54 species), and Trichomycteridae (54 species); the remaining 42 families having 1 to 52 species. Present data indicate that 311 of the species occur solely at locations within Colombia. Continued descriptions of new species from the continental waters of Colombia demonstrate that the present total underestimates the species-level diversity of the ichthyofauna. The 1435 species living in Colombian freshwaters represent approximately 5% of all freshwater and marine fish species now recognized worldwide and approximately 29% of the freshwater fish species known to inhabit the drainages across the expanse from the southern border of Mexico through to Chile and Argentina. Various historical and ecological factors potentially contributing to the species-level richness of the Colombian freshwater fish fauna are discussed (e.g. geology, climate, physiography, water chemistry)

    Desarrollo de algoritmos de procesamiento de imágenes basados en "Operadores de Ventana" sobre una FPGA

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    Con el avance de la tecnología las FPGAs se han convertido en una herramienta indispensable en el diseño rápido y eficiente de proyectos que requieren procesamiento digital y lógica programable. Es por eso que se ha convertido en la principal herramienta para la implementación de los algoritmos de procesamiento Digital de imágenes presentados en este trabajo. Debido a la gran cantidad de algoritmos para procesamiento de imágenes basados en los Operadores de Ventana, se llega a la necesidad de bloques reusables que permitan implementar los diferentes algoritmos basados en dichos operadores. En base a dichos bloques y mediante el agregado de un bloque adicional específico de cada algoritmo de procesamiento se puede implementar de manera eficiente y con un mínimo desarrollo una diversidad de filtros para procesamiento de imágenes que permiten el realce, acondicionamiento y la obtención de información de las diferentes imágenes en el campo de la Medicina. Para la implementación del sistema basado en Operadores Morfológicos, previa simulación en matlab, se realizó una interfaz serial que permite enviar los pixeles a procesar en la FPGA, y luego del procesamiento, (mediante tres bloques que implementan el algoritmo), recuperar la imagen procesada y acondicionada.Facultad de Ingenierí

    Marine sponges of the genus neopetrosia with anti-inflammatory activity

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    The present study aimed to investigate the anti-inflammatory effect of marine sponges of the genus Neopetrosia which are abundant in the Colombian Caribbean. We obtained three fractions from a total methanolic extract of Neopetrosia rosariensis and proxima. In vivo activity was measured using λ-carrageenan-induced paw edema assay. The in vitro inhibitory effects were evaluated on myeloperoxidase activity (MPO) and nitric oxide (NO), prostaglandin E2 (PGE2), and tumor necrosis factor alpha (TNF- α) production. Total extracts of N. rosariensis and N. proxima (100 mg/Kg) significantly inhibited the paw edema of rats (71.74% and 60.06%, respectively). Dichloromethane and methanol fractions of Neopetrosia sponges reduced MPO activity. Only, dichloromethane fraction of N. rosariensis significantly inhibited NO (66%), PGE2 (30.5%) and TNF-α production (72%). Our results show anti-inflammatory activity in extracts and fractions from species of marine sponges belonging to Neopetrosia genus and open the way for complementary studies to purify and identify active molecules.Colegio de Farmacéuticos de la Provincia de Buenos Aire
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