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Search Results: 1 - 10 of 38315 matches for " Luis Benítez "
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Diáspora salvadore a: identidades y mapas culturales en el ciberespacio
José Luis Benítez
Encuentro , 2008,
Abstract: EL FENóMENO DE LA MIGRACIóN INTERNACIONAL PLANTEA NUEVOS desafíos de investigación al campo académico de la comunicación. En esta perspectiva, algunos estudios de comunicación han analizado el papel de los medios de comunicación y sus narrativas mediáticas sobre la migración, la construcción de imaginarios sociales acerca de la experiencia de emigrar, y la importancia de las nuevas tecnologías enlas prácticas cotidianas de los inmigrantes. En este contexto, este artículo explora algunos contenidos y formatos que grupos y comunidades migrantes salvadore as construyen desde sitios y páginas web, usos de medios de comunicación local y nacional accesibles desde el Internet, y nuevas plataformas de redes sociales como los blogs, Myspace, Facebook, YouTube, entre otros. Por tanto, este artículo intenta dibujar algunos trazos de mapas culturales y expresiones de identidades colectivas que la diáspora salvadore a construye día a día en el ciberespacio.
Asimetría Fluctuante: Una herramienta morfo-funcional para Medir Estabilidad del Desarrollo
Benítez,Hugo A; Parra,Luis E;
International Journal of Morphology , 2011, DOI: 10.4067/S0717-95022011000400066
Abstract: the ability of an organism to produce an ideal phenotype, despite the disturbances encountered during its development is the causal mechanism of the developmental stability (ds). this ability is used to evaluate a variety of stress types and the genotypic ability to correct them. the measurement tool mostly used to estimate the ds is the fluctuating asymmetry (fa), this being a small measure of random deviations that occur between the left and right sides of bilaterally symmetrical features. the study of fa management in its simplicity and speed in obtaining results has become the focus of interest in biology, and during the last years, and although there has been a progressive increase in published articles using fa to evaluate disturbances in the ds, many questions remain as to what constitutes the underlying causes that generate fa. this review compiles information on the progress in studies of fa use, its methodology, mechanisms, benefits and controversies in time, and proposes that it is strictly necessary to generate a better understanding of this tool, and as a result the use of more precise study models that justify a unified approach to the analysis of patterns in fa and ds.
HALLAZGO DE MERCURIO EN PECES DE LA CIéNAGA DE AYAPEL, CóRDOBA, COLOMBIA
Marrugo,José; Lans,Edineldo; Benítez,Luis;
Revista MVZ Córdoba , 2007,
Abstract: objetive. to establish total mercury (hg-t) concentrations in some fishes species in the ayapel marsh (colombia). materials and methods. sampling was conducted from july 2004 to june 2005, including both the dry and rainy seasons. hg-t was analized by cold vapor atomic absorption spectroscopy after acid digestion. results. the highest concentrations in hg-t were observed for analized samples of the carnivorous specie ageneiosus caucanus (0.504±0.103 mg hg kg-1 fresh weight), and the lowest concentrations in the iliophagus specie prochilodus magdalenae (0.130±0.056 mg hg kg-1 fresh wt). the highest hg-t concentrations were found in the samples of the dry season. the hg-t mean levels for fish samples did not exceed the human limit consumption level according to the world health organization (who, 0.5 mg hg kg-1 fresh weight). conclusions. the risk assessment based on the hazard index suggested that the consumption of 0.12 kg per day of fish (mainly carnivorous) could increase the risk of mercury poisoning in the local population.
Asimetría Fluctuante: Una herramienta morfo-funcional para Medir Estabilidad del Desarrollo Fluctuating Asymmetry: A Morpho-functional Tool to Measure Development Stability
Hugo A Benítez,Luis E Parra
International Journal of Morphology , 2011,
Abstract: La capacidad de un organismo para producir un fenotipo ideal, pese a las perturbaciones encontradas durante su desarrollo, es el mecanismo causal de la estabilidad del desarrollo (ED). Esta capacidad es utilizada para evaluar variedad de tipos de estrés y la capacidad genotípica de corregirlos. La herramienta de medición más utilizada para estimar la ED es la asimetría fluctuante (AF), siendo esta una medida de las peque as desviaciones al azar que ocurren entre el lado izquierdo y derecho de rasgos bilateralmente simétricos. El estudio de AF, por su simplicidad de manejo y rapidez en la obtención de resultados, se ha convertido en un foco de interés para la biología, y durante los últimos a os el aumento en artículos publicados usando AF para evaluar perturbaciones en la ED ha sido progresivo, pero aun así existen muchas interrogantes de cuales son las causas subyacentes que generan la AF. La presente revisión recopila información sobre el avance en los estudios del uso de la AF, su metodología, mecanismos, ventajas y controversias en el tiempo, y propone que es estrictamente necesario generar una mejor comprensión de esta herramienta, producto de eso, la utilización de modelos más exactos de estudio que signifiquen (o justifiquen) un enfoque unificado en el análisis de los patrones en AF y ED. The ability of an organism to produce an ideal phenotype, despite the disturbances encountered during its development is the causal mechanism of the developmental stability (DS). This ability is used to evaluate a variety of stress types and the genotypic ability to correct them. The measurement tool mostly used to estimate the DS is the fluctuating asymmetry (FA), this being a small measure of random deviations that occur between the left and right sides of bilaterally symmetrical features. The study of FA management in its simplicity and speed in obtaining results has become the focus of interest in biology, and during the last years, and although there has been a progressive increase in published articles using FA to evaluate disturbances in the DS, many questions remain as to what constitutes the underlying causes that generate FA. This review compiles information on the progress in studies of FA use, its methodology, mechanisms, benefits and controversies in time, and proposes that it is strictly necessary to generate a better understanding of this tool, and as a result the use of more precise study models that justify a unified approach to the analysis of patterns in FA and DS.
Effect of cadmium on the coelomic cellular response of Pyura vittata (Stimpson, 1852)
Luis Arredondo,Roseulys Benítez,Mairin Lemus
RETEL : Revista de Toxicología en Línea , 2012,
Abstract: The marine and terrestrial ecosystems are exposed to many types of contaminants in which protrude the heavy metals by their high persistence, non-degradability and toxicity. Many organismos have been used to assess the presence of these elements. In this paper Pyura vittata was used to evaluate the effect of a sublethal dose of cadmium on the coelomic cell population. Sublethal dose was estimated at 96 h following the methodology proposed by the Environmental Protection Agency of the United States later sublethal dose was selected for conducting chronic tests for 21 days. We determined the incorporation of metal in the hepatopancreas muscle, tunic and gills. Samples were taken from the coelomic fraction at 3, 7.15 and 21 days of exposure to assess the fraction of celomocitos. Coelomic fraction was obtained and performed total cell count, percentage of viable cells and percentage of each cell type. The median lethal dose for P. vittata exposed to cadmium was 0.02 mg/l. The results determined that cadmium induces an increase in the number of celomocitos in short periods of exposure, three days, however during chronic exposure of 21 days, the organisms tend to standardize the cell number.
HALLAZGO DE MERCURIO EN PECES DE LA CIéNAGA DE AYAPEL, CóRDOBA, COLOMBIA
José Marrugo,Edineldo Lans,Luis Benítez
Revista MVZ Córdoba , 2007,
Abstract: Objetivo. Determinar las concentraciones de mercurio total (Hg-T) en algunasespecies de peces de la ciénaga de Ayapel (Colombia). Materiales y métodos. Losmuestreos fueron realizados desde Julio de 2004 a Junio de 2005, incluyendo lasépocas seca y lluviosa. Las muestras fueron analizadas por espectrometría deabsorción atómica por vapor frío después de digestión ácida. Resultados. Lasconcentraciones más altas de Hg-T se observaron para las muestras analizadas dela especie carnívora Ageneiosus caucanus (0.504±0.103 mg Hg kg-1 peso fresco), ylas menores concentraciones en la especie Iliófaga Prochilodus magdalenae(0.130±0.056 mg Hg kg-1 peso fresco). Las concentraciones más altas fueronencontradas en las muestras de la época seca. Los niveles promedio de Hg-T en lasmuestras de peces no excedieron el límite para consumo humano establecido por laOrganización Mundial de la Salud (OMS, 0.5 mg Hg Kg-1 peso fresco). Conclusiones.La evaluación del riesgo basado en el índice de peligrosidad sugiere que el consumode 0.12 kg de pescado por día en la población humana (principalmente carnívoros)podría incrementar el riesgo de envenenamiento por mercurio en la población local.
Myths and Realities about Mexico-United States Migration  [PDF]
Luis Arturo Rivas Tovar, Adela Chávez, Juan Enrique Azuara Munguía, Ana Gabriela Benítez Jurado
iBusiness (IB) , 2014, DOI: 10.4236/ib.2014.62008
Abstract:

This is an article review of state-of-the-art about Mexicans’ migration to the USA, in last 5 years. We analyzed 4 myths: 1). Migration generates negative effects for the receiving country because when migrants arrive. 2). Mexicans’ migration to the USA generates big distortions in the receiving communities and Mexico is the only economic beneficiary. 3). Migrants collapse public health services in USA. 4). Mexican migrants are mistreated by American authorities. The findings will show the lack of empirical evidence of these generalized ideas.

Determinantes clínicos de la presión de fin de diástole
Benítez,Luis Miguel; Narváez,José Vicente;
Acta Medica Colombiana , 2007,
Abstract: abstract introduction: many cardiovascular diseases may cause heart failure, because of impairment of systolic or diastolic function, or both. it is frequently observed that regardless of physiopathological processes that were presumed to cause major symptoms, some patients have normal or quite normal functional class of dyspnea. this observation is sometimes confirmed in the cath lab, when the measured end diastolic pressure (edp) is normal. objective: to study which clinical factors are related with changes in edp. methods: 200 patients were included in a sample of 1.730 patients studied in the cath lab during 2005. this retrospective, descriptive and analytic study seeked for association between edp and independent variables such as: age, sex gender, weight, clinical risk factor for coronary artery disease, the clinical presentation, ejection fraction (ef) measured, structural changes in left ventricle morphology (dilatation or hypertrophy), extent of coronary disease (one, two or three-vessel disease, normal coronaries, or reduced intracoronary flow), and the coronary artery involved. statistically, a simple linear regression model was applied in the stata 9 program. results: increasing variability in the edp was found to be significantly related with: hypertension, dilated left ventricle, 3-vessel disease, left coronary descendant and right coronary artery involvement. decreasing variability of edp presented with increasing ef and normal coronary arteries. conclusions: some clinical factors were confirmed as related with altered edp, but others, such as the more unstable clinical conditions and hypertrophy, surprisingly showed no significant relation with edp variations. this investigation offers new pathways to future clinical studies in this area.
OBSERVACIóN AL SENTIDO DE LOS PROCESOS PENALES MEXICANOS DESDE EL SISTEMISMO AUTORREFERENCIAL
García Rosas,Elias; ávila Benítez,Luis;
Ius et Praxis , 2009, DOI: 10.4067/S0718-00122009000200007
Abstract: the purpose of the research here described, was to investigate the meaning of the mexican criminal trials' model, that because there are no theorical or practical sustainable references to establish it. in the study, self-steering systems theory of niklas luhmann and his functional method were used, developing a documental research and following a second-order observation thecnique, under a constructivistic epistemological view. was found that the mexican trials' systemic meaning is accomplishing the definitive judicial solution, excluding other themes traditionally considered trial's goals, such as the "historic truth", paradigm which breaks down with the results achieved.
β-Lactamasas de Espectro Expandido en Enterobacterias aisladas en Centros de Salud de Caracas
Torres,Luis; Gagliotta,Vanesa; Torres,Orlando; Benítez,Minerva;
Revista de la Sociedad Venezolana de Microbiología , 2006,
Abstract: the extended-spectrum ?-lactamases (esbls) are ?-lactamases produced by a variety of gram-negative bacteria that confers resistance to cephalosporins of third and quarter generation and aztreonam. they are most commonly produced by isolates of k. pneumoniae and e. coli, although the plasmidic nature of the genes that encode them has allowed a wide dissemination to other bacterial genera. a phenotypical and molecular detection of esbls were carried out to 224 enterobacteria isolates from eight health centers of caracas . a 91.1% of stumps analyzed by double disk method and the nccls 2004, were esbls' producers. the mic analysis for ceftazidime, cefotaxime, cefepime and aztreonam showed a bigger proportion of stumps esbl with ceftazidimase activity compatible to the shv families and/or tem, and in a smaller proportion to the ctx-m family. the pcr results based on genes blashv, blatem and blactx-m, amplification confirmed a predominance of shv-esbl (72%) and ctx-m-esbl (21.1%). therefore, carbapenems with 100% of sensibility constitute the best therapeutic option. this investigation has allowed the detection of circulating esbls type in eight hospitals, and is also the first report that determines the ctx-m type esbls in our country.
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