oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 25 )

2018 ( 185 )

2017 ( 203 )

2016 ( 260 )

Custom range...

Search Results: 1 - 10 of 146684 matches for " F. Restrepo-Betancur "
All listed articles are free for downloading (OA Articles)
Page 1 /146684
Display every page Item
Caracterización de las propiedades del aire húmedo (Sicrometría) del microclima de la hacienda Vegas de la Clara (nordeste antioque?o, Colombia)
Estrada-Pareja,Mónica M; Márquez-Girón,Sara M; Restrepo-Betancur,Luis F;
Revista Colombiana de Ciencias Pecuarias , 2007,
Abstract: an exploratory descriptive statistical analysis was applied for determining the characteristics of the humid air (sicrometría) of the microclimate of vegas de la clara farm (northeast antioque?o) were determined, for which the atmospheric pressure (910.41 kg/cm2), ambient temperature (25 ± 3.264 oc), and relative humidity (75.4 ± 11.97%) were measured, at different times of the year (rainy, transition time and dry periods). from these results a psychrometric chart was constructed and used as a tool for an experimental study focused on the estimation of heat losses in broilers during its finishing period reported elsewhere.
Caracterización de las propiedades del aire húmedo (Sicrometría) del microclima de la hacienda Vegas de la Clara (nordeste antioque o, Colombia) Determination of the states of the humid air (psychrometric) of the microclimate of the Vegas de la Clara farm (nordeste antioque o, Colombia)
Mónica M Estrada-Pareja,Sara M Márquez-Girón,Luis F Restrepo-Betancur
Revista Colombiana de Ciencias Pecuarias , 2007,
Abstract: Mediante un análisis estadístico descriptivo exploratorio se determinaron las características del aire húmedo (Sicrometría) del microclima de la hacienda Vegas de la Clara (nordeste antioque o), para lo cual se midieron la presión atmosférica (910.41 kg/cm2), la temperatura ambiente (25 ± 3.264οC), y la humedad relativa (75.4 ± 11.9%), en diferentes momentos del a o (periodos de lluvia, época de transición y periodo seco). A partir de los resultados se construyó la carta Sicrométrica como herramienta para el estudio posterior sobre las pérdidas de calor de los pollos en la etapa de finalización del periodo productivo (publicada en otro artículo de este mismo volumen). An exploratory descriptive statistical analysis was applied for determining the characteristics of the humid air (Sicrometría) of the microclimate of Vegas de la Clara farm (northeast antioque o) were determined, for which the atmospheric pressure (910.41 kg/cm2), ambient temperature (25 ± 3.264oC), and relative humidity (75.4 ± 11.97%) were measured, at different times of the year (rainy, transition time and dry periods). From these results a psychrometric chart was constructed and used as a tool for an experimental study focused on the estimation of heat losses in broilers during its finishing period reported elsewhere.
Relationship between Plant Species Diversity and Plant Biomass of Orchard Grass and Lucerne Sown in Different Ratios in the Province of Salamanca, Spain  [PDF]
M. Medina-Sierra, M. Igual-Arroyo, F. Restrepo-Betancur, A. Valverde-Portal, I. Santa-Regina
Open Journal of Forestry (OJF) , 2017, DOI: 10.4236/ojf.2017.73020
Abstract: A field experiment was carried out at the CSIC Muñovela farm belonging to the Spanish National Research Council (CSIC) in order to evaluate the effect of sowing orchard grass (Dactylis glomerata var. Trerano) and lucerne (Medicago sativa var. Aragon) in monoculture and in combination. The experiment was based on a randomized block designed with a factorial arrangement (5 × 2). Experimental units were 40 plots distributed in four blocks. The phosphorus fertilization (P) factor included two types of conditions: basal fertilization without phosphorus (-P) and basal fertilization with phosphorus (+P), and the vegetation cover factor (T) included five conditions depending on the grass (G) and the legume (L). Above-ground biomass showed statistically significant differences among seasons and years (P < 0.05). However, no statistically significant differences treatments were found among various treatments. The presence of the grass species Lolium perenne L. and Poa pratensis L. throughout the three years indicated that both species significantly increased their presence over time regardless of the treatments applied. The analysis performed for the other plant species (those other than grasses and legumes) allowed us to determine that the T1 and T5 treatments, which correspond to single species not treated with the application of phosphorus, influenced the presence of 70% of other species planted. Our specific aim was to explore how changing plant biotic diversity affects productivity under a given set of conditions. We manipulated plant species richness as an experimental factor to determine if productivity would be affected by changes in the ratios of plants sown.
Estudio clínico y hematológico de una infección experimental con Aeromonas hydrophila y Edwardsiella tarda en tilapia, Oreochromis sp
Vásquez-Pi?eros,Mónica A.; Rondón-Barragán,Iang S; Restrepo-Betancur,Luis F; Eslava-Mocha,Pedro R.;
ORINOQUIA , 2010,
Abstract: opportunistic bacteria as a. hydrophila and e. tarda are related to haemorrhagic septicaemia outbreaks in cultured tilapias in our country, being the aetiological agents of highest participation on the diagnosis of infection disease in cultures of oreochromis sp., in departamento del meta. this article reports a clinical and hematological study of tilapia hybrid (50-70g) during the experimental infection with aeromonas hydrophila and edwardsiella tarda made by intraperitoneal inoculation of 7 x 108 cfu/ml and 2 x 108 cfu/ml of a. hydrophila and e. tarda, respectively. from 11 hours infected fish showed paleness, lethargy, gasping, increased respiratory frequency and loss of swim axis. at hematological examination, infected animals showed severe lymphopenia, increased monocytes, hemolysis, increased blastic cells, karyorrhexis, hypochromia and anisocytosis, which is characteristic of a hypochromic anemia and erythroclasia described in fish bacterial infection. at necropsy examination, fish inoculated with bacteria showed: hemorrhages on the base of fins and internal organs, pale and mottled liver, increased abdominal fluid and blood-stained fluid in intestine, unlike control animals that did not show these lesions. additionally, hepatomegaly was observed in experimental infected animals, even though there were not significance differences in the hepatosomatic index of these animals with respect to control. in treatment of e. tarda, whitish nodules with multifocal distribution were observed in spleen. during the present study, hybrid tilapias infected with e. tarda y a. hydrophila, showed a clinical condition compatible with haemorrhagic septicaemia, possibly associated to extracellular products (ecp), such as hemolysins and aerolisyns, with hemolytic and cytotoxic activity in fish, among other factors. this work is an approximation to a model of study of bacterial disease of tilapia with pathogenic strains isolated in the region.
Prevalencia de Parasitosis Intestinales y Factores Asociados en un Corregimiento de la Costa Atlántica Colombiana
Agudelo-Lopez,Sonia; Gómez-Rodríguez,Lucila; Coronado,Xiomara; Orozco,Adalina; Valencia-Gutierrez,Carlos A.; Restrepo-Betancur,Luis F.; Galvis-Gómez,Luisa A.; Botero-Palacio,Luz E.;
Revista de Salud Pública , 2008, DOI: 10.1590/S0124-00642008000400013
Abstract: objectives determining the prevalence of intestinal parasitism and identifying the associated risk factors in the village of loma arena, bolivar department, colombia. methodology the community's sanitary and educational conditions were evaluated by using a questionnaire which was applied to each family group. two stool samples obtained by spontaneous evacuation, on two different days, were gathered from each participating person for the coproparasitological study. the coprological test involved direct examination in saline physiological solution and temporary staining with lugol's solution and the formol-ether concentration method. results it was found that 92 % of the population was parasitised, 92 % of them with at least one pathogenic parasite. polyparasitism was very important (89,2 %); a maximum of 7 species per host was found. helminth and protozoa coinfection was frequent (64 %). there was only 0,9 % teniosis prevalence. there was a significant association between symptomatology and parasite presence (p< 0.05), though such relationship was not seen with potentially pathogenic parasites (with the exception of trichuris trichura and abdominal pain). the statistical analysis did not reveal any relationship between parasitism and educational level or sanitary habits. conclusion the uniform distribution of most intestinal parasites amongst the five age-groups evaluated showed that people in loma arena were evenly exposed to sources of infection in all age-groups.
Inmovilización de lactobacillus helveticus en soportes vítreos obtenidos por tecnología sol-gel
Betancur, J. F.,Restrepo, Y. B.,Abad, P.,Arias, M.
Boletín de la Sociedad Espa?ola de Cerámica y Vidrio , 2003,
Abstract: The immobilization of bio catalyst agents like cells and enzymes, is a tool used to improve and simplify biotechnical continued industrial processes, given that it allows to work with higher concentrations of the bio catalyst agent, retain it inside the bioreactor to avoid their loss in the outside current, decreases the number of separation operations, and therefore, the cost of purification of the product. For such an end, we studied the technical feasibility of immobilizing cells of lactobacillus helveticus encapsulating it in supports elaborated by means of Sol-Gel process using as precursor tetraetil-orto-silicate (TEOS) and later, with immobilized cells, we studied the viability of the cells through its capacity of conversion of the lactose coming from the serum of milk in lactic acid. These results were compared with those obtained using free cells under the same operation conditions, and it was observed that the immobilized cells didn’t only conserve their metabolic activity, but rather, in some cases, the conversion of lactose to lactic acid was improved. Obtained particles had size distribution among 1 - 3 mm, good mechanical resistance, stability in the support, and a pore size that it was not highly restrictive to the transfer of molecules between support and product. Finally, the immobilized cells showed good behaviour during at least five successive fermentations of 40 hours each one. La inmovilización de biocatalizadores tales como células y enzimas, es una herramienta utilizada en el mejoramiento de procesos biotecnológicos que permite trabajar con concentraciones más altas del biocatalizador retenido dentro del bio-reactor, y evitar su pérdida en la corriente efluente. Así; entre otras ventajas, se facilita operar en forma continua reduciendo el número de operaciones de separación y por lo tanto, el costo de purificación del producto. Para tal fin, inicialmente se estudia la factibilidad técnica de inmovilizar células de lactobacillus helveticus por atrapamiento en soportes vítreos elaborados mediante tecnología sol-gel, utilizando como precursor tetraetil-orto-silicato (TEOS). Posteriormente, se determina la viabilidad de las células inmovilizadas a través de su capacidad de convertir en ácido láctico la lactosa proveniente del suero de leche. éstos resultados se compararon con los obtenidos utilizando células libres bajo las mismas condiciones de operación, y se observó que las células inmovilizadas además de conservar su actividad metabólica, en algunos casos mejoraron la conversión a ácido láctico. Se obtuvieron partículas estables
Modelación de las funciones de crecimiento aplicadas a la producción animal
Agudelo Gómez,Divier A; Cerón Mu?oz,Mario F; Restrepo Betancur,Luis F;
Revista Colombiana de Ciencias Pecuarias , 2008,
Abstract: animal growth is one of the most important aspect for evaluating animal productivity in beef cattle enterprises and in some cases it is used as a criterion of selection, nevertheless, the fact that animal growth is not exclusively due to genetic factors but also, to environmental effects must be keep in mind. measurement of animal growth have been performed by lineal and no-lineal mathematical models, choosing they for their fitness of adjustment and the feasibility for biological interpretation of their parameters. recently the mixed models have been used in which their parameters are composed of fixed and random effects representing the expected values and variance of the fixed ones, respectively, which permits to evaluate the variability of different curves between individuals of a population, as well as the covariance between parameters. the most used criteria for selection of the curve that best fit data are: determination coefficient and the percent of significant and atypical curves found for each function. in addition, other models as the akaike information criteria and bayesian information criteria can also be applied. the objective of the present review is to provide the criteria for application of linear and non linear models in analyzing animal growth.
Modelación de las funciones de crecimiento aplicadas a la producción animal Modela o das fun es do crescimento aplicadas a lá produ o animal Modeling of growth functions applied to animal production
Divier A Agudelo Gómez,Mario F Cerón Mu?oz,Luis F Restrepo Betancur
Revista Colombiana de Ciencias Pecuarias , 2008,
Abstract: El crecimiento animal es uno de los aspectos más importantes al momento de evaluar la productividad en las explotaciones dedicadas a la producción de carne y en algunos casos es usado como criterio de selección, sin embargo, debe tenerse en cuenta que el crecimiento no se debe exclusivamente a factores genéticos sino también, a efectos ambientales. Para medir el crecimiento animal se han usado diferentes modelos matemáticos lineales e no lineales, eligiéndolos por su bondad de ajuste y la facilidad de interpretación biológica de sus parámetros. Recientemente se han usado modelos mixtos en los que sus parámetros están compuestos de efectos fijos y efectos aleatorios, representando los valores esperados y la varianza de los primeros, respectivamente, lo que permite evaluar la variabilidad de las diferentes curvas entre los individuos de una población, así como la covarianza entre los parámetros. Los criterios más usados para elegir la curva que mejor ajusta a los datos son: el coeficiente de determinación, el porcentaje de curvas significativas y atípicas encontradas para cada función; además se pueden aplicar criterios como el criterio de información Akaike y el criterio de información Bayesiano. El objetivo del presente trabajo es indicarle al lector una aplicación de los modelos no lineales y no lineales mixtos en el análisis del crecimiento animal. O crescimento animal é um dos aspectos mais importantes no momento de avaliar a produtividade nos sistemas de produ o dedicados á produ o de carne. Em alguns dos casos é usado como critério de sele o, mais é necessário ter em conta que depende de fatores ambientais e genéticos. Para medir o crescimento animal tem-se utilizado diferentes modelos matemáticos lineares e n o lineares, entre outros, os quais a escolha do melhor modelo é realizada pela qualidade do ajuste e da interpreta o biológica de seus parametros. Recentemente, tem-se utilizado modelos mistos nos quais os parametros est o compostos por efeitos fixos e aleatórios, representando os valores esperados e a variancia dos primeiros, respectivamente, o que permite avaliar a variabilidade das diferentes curvas entre os indivíduos de uma popula o, assim como a covariancia entre os parametros. Os critérios mais utilizados para escolher a curva que melhor ajuste os dados s o: o coeficiente de determina o, a porcentagem de curvas significativas e atípicas encontradas para cada fun o; alem do mais, podem-se aplicar critérios como o critério de informa o de Akaike e o critério de informa o Bayesiano. O objetivo do presente trabalho foi indicar-lhe
Efecto de la temperatura y la humedad relativa en los parámetros productivos y la transferencia de calor en pollos de engorde
Estrada-Pareja,Mónica M; Márquez-Girón,Sara M; Restrepo Betancur,Luis F;
Revista Colombiana de Ciencias Pecuarias , 2007,
Abstract: to achieve maximum productive yields in broiler production, it is indispensable to manage an appropriate environment that provides to the birds the good environmental conditions. in this work the effect of temperature and relative humidity in the productive performance and transfer of heat in broilers was evaluated, with the purpose of establishing the thermal comfort zone in the microclimate of vegas de la clara farm (nordeste antioque?o, colombia), to optimize the production models. in the first part of the work, the behaviour of breed ross chickens in the breeding stage was determined by means of an exploratory descriptive statistical analysis, measuring changes of corporal temperature from birth (heterothermos with (corporal temperature of 39.741 ± 0.44 oc), until the chickens reached the endothermos condition (corporal temperature of 40.37 ± 0.221 oc); when concluding this stage the homogeneity of the lot was determined, concerning body weight, with the purpose of obtaining uniformity in the experimental units (chickens) to carry out the experimental phase corresponding to the final stage of the productive period. in the experimental phase, the influence of three different temperatures (19, 25 and 31 oc) with a constant relative humidity of 75% on heat transfer and broiler productive yield as measured by food consumption, body weight, nutritional conversion and morbi–mortality, was evaluated. the results were evaluated by manova with canonical contrasts and a totally randomized design of structures. the best productive behaviour to body weight and nutritional conversion was obtained at a temperature of 19 oc when compared to the other treatments (p<0.05). heat losses were represented in a psychrometric cart, which indicated that treatment at 19 oc, followed by treatments at 31 oc and 25 oc (p<0.05), represented the greatest losses of sensible heat, respectively. regarding latent heat losses statistically significant differences were no found (p>0.05).
Efecto de la temperatura y la humedad relativa en los parámetros productivos y la transferencia de calor en pollos de engorde Effect of temperature and relative humidity on the productive behaviour and the transfer of heat in broilers
Mónica M Estrada-Pareja,Sara M Márquez-Girón,Luis F Restrepo Betancur
Revista Colombiana de Ciencias Pecuarias , 2007,
Abstract: Para lograr máximos rendimientos productivos en las explotaciones de pollo de engorde, es imprescindible manejar un entorno adecuado que les proporcione a las aves las condiciones ambientales óptimas. En este trabajo se evaluó el efecto de la temperatura y la humedad relativa en la respuesta productiva y transferencia de calor en pollos de engorde, con el propósito de establecer la zona termo-neutral en el microclima de la hacienda Vegas de la Clara (nordeste antioque o, Colombia), para optimizar los modelos de producción. En la primera parte del trabajo, se determinó, mediante un análisis estadístico descriptivo exploratorio el comportamiento térmico de los pollos de la línea Ross en la etapa de cría, midiendo los cambios de temperatura corporal desde el nacimiento (heterotermos con temperatura corporal de 39.741 ± 0.44 oC), hasta que alcanzaron la condición de endotermos (temperatura corporal: 40.37 ± 0.221 oC); al finalizar ésta etapa fue determinada la homogeneidad del lote, en cuanto a pesos corporales, con el propósito de obtener uniformidad en las unidades experimentales (pollos) para llevar a cabo la fase experimental correspondiente a la etapa final del periodo productivo. En la fase experimental, se evaluó los efectos de tres diferentes temperaturas (19, 25, y 31 oC) a una humedad relativa del 75% en la transferencia de calor y en el rendimiento productivo, por medio de consumo de alimento, peso corporal, conversión alimenticia y morbi – mortalidad. Mediante la aplicación de la técnica de MANOVA con contrastes canónicos y un dise o de estructuras completamente aleatorizado se determinó que el mejor comportamiento productivo para el peso corporal y la conversión alimenticia se obtuvo a una temperatura de 19 oC (p<0.05) con respecto a los demás tratamientos. Las pérdidas de calor representadas mediante la graficación en la carta Sicrométrica, indicaron mayores pérdidas de calor sensible en el tratamiento a 19 oC, seguido del tratamiento a 31 oC y luego del tratamiento a 25 oC (p<0.05). En cuanto a las pérdidas de calor latente no se encontraron diferencias estadísticamente significativas (p>0.05). To achieve maximum productive yields in broiler production, it is indispensable to manage an appropriate environment that provides to the birds the good environmental conditions. In this work the effect of temperature and relative humidity in the productive performance and transfer of heat in broilers was evaluated, with the purpose of establishing the thermal comfort zone in the microclimate of Vegas de la Clara farm (Nordeste antioque o, Colombia), to
Page 1 /146684
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.