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Search Results: 1 - 10 of 43582 matches for " Diego Ramírez "
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LA PLANIFICACIóN DE LA ACCIóN APLICADA A LOS SISTEMAS DE PSA
ALEJANDRO ARANGO RAMíREZ,DIEGO PAREDES CUERVO
Scientia Et Technica , 2008,
Abstract: Buscando aportar una de las primeras aproximaciones metodológicas al tema del pago por servicios ambientales (PSA) en la cuenca del río Otún (Risaralda, Colombia) se propuso un plan de acción para la instalación de un sistema de PSA en la zona. El resultado principal de este proceso fue la definición de las actividades, responsabilidades y recursos para la implementación de un proyecto piloto de PSA enfocado en la calidad hídrica y la conservación de la biodiversidad y que incluirá como proveedores a una muestra representativa de propietarios de tierra donde se practique la actividad ganadera y el cultivo de cebolla.
Producción primaria, biomasa y composición taxonómica del fitoplancton costero y oceánico en el Pacífico colombiano (septiembre-octubre 2004)
Ramírez,Diego G; Giraldo,Alan; Tovar,Jorge;
Investigaciones marinas , 2006, DOI: 10.4067/S0717-71782006000200023
Abstract: quantitative and qualitative studies of the phytoplankton community were carried out at two coastal and two oceanic stations in the colombian pacific. the 43 species identified in the study area included 19 diatoms and 24 dinofiagellates. the average diversity values were greater at the coastal (2.89 bits·cel-1) than at the oceanic (1.42 bits·cel-1) stations. the same was true of primary production, with estimated values of 155.87 (coastal) and 60.50 mgc·m-2·h-1(oceanic). the chlorophyll-a concentration fiuctuated between 11.37 and 32.35 mg·m-2, as an integrated value in the frictional infiuence zone (0-50 m depth). a positive correlation was found for primary production with species diversity (r = 1.0) and with the nitrite concentration (r = 0.8), whereas the reverse was found with the phosphate concentration (r = -1.0). these results represent the first attempt to estimate primary production in the oceanic waters of the colombian pacific basin, providing a starting point for other such studies in this area
Modelos unifactoriales de tipos de interés: aplicación al mercado Colombiano
Restrepo Tobón,Diego Alexander; Botero Ramírez,Juan Carlos;
Cuadernos de Administración , 2008,
Abstract: this article is a first approach to implementing in the colombian market the unifactorial interest rate models developed by hull and white (1990) and by black and karasinski (1991) with constant volatility and reversion velocity parameters. the main findings from this research are 1) implementing both models using trinomial trees enables accurately replicating the forward structure of market interest rates; 2) the parallel movements of the installment structure of interest rates in colombia explains most of their variability, thus, using unifactorial models such as the ones proponed herein is appropriate; 3) the volatility and reversion velocity mean parameters on the mean short-term interest rate must be estimated using time series econometric models; 4) future articles must broach the problems related to coverage using such types of models, to estimating volatility structures and surfaces, and to multifactorial model calibration.
Concordancia de la evaluación objetiva y subjetiva en la predicción y hallazgo de vía aérea difícil
Meléndez,Héctor J; Leal,Douglas; Ramírez,Diego;
Revista Colombiana de Anestesiología , 2010,
Abstract: introduction. when assessing the airway, there are multiple factors that hinder the accurate prediction of the degree of difficulty for airway management. during the physical examination, disagreement among the physicians with regards to the definition and use of predictive factors of a difficult airway is crucial. most assessments are subjective, not all the validated predictors are used and usually the assessment is made in an emergency setting with the patient in decubitus position, giving rise to disagreement in the diagnosis of a difficult airway. objective. to assess the agreement between objective and subjective predictions and the finding of a difficult airway in a sitting and decubital position, by anesthesiologists and residents. materials and methods. this was a trial for evaluating diagnostic technology. the estimated sample included 116 patients with 100 % follow-up. the patients were from the santander university hospital with a 1 - 3 asa score. agreement was established using kappa values. every predictor was evaluated for performance (sensitivity, specificity, prognostic values) and finally, a logistic regression model was developed. results. the level of agreement between the objective and subjective evaluation of the difficult airway in both positions was poor. the mallampatti classification gave the best kappa index (0,20). intraobserver agreement was excellent or good. in general, all predictors were specific and low in sensitivity. just the mouth opening and mallampati classification in the predictive model exhibited a significant odds ratio (or), which stresses the believe that an accurate oral cavity evaluation is an appropriate predictor for a difficult airway.
Condiciones de seguridad en calderas de vapor de empresas afiliadas a una administradora de riesgos profesionales en Antioquia, 2009
Sepúlveda M,Diego L; Ramírez G,Jairo;
Revista Facultad Nacional de Salud Pública , 2011,
Abstract: objective: to determine the safety conditions of steam boilers in companies associated with a professional risk administration company in antioquia, colombia. to this end, their operation conditions shall be characterized, the associated risks identified, and their safety level assessed. methodology: a descriptive cross-sectional study was carried out in twenty companies whose production processes involve boilers. a survey on the conditions for operation was applied on both the maintenance managers and the boilers operators in each company. a hazard risk assessment matrix was made as instructed in the gtc-45 colombian technical guide, and an assessment instrument was applied to determine the safety level for each boiler. results: 70% of the assessed boilers obtained a low score (less than 65 points) according to the scale, which has been validated by experts; the remaining boilers obtained an acceptable score (66 to 81 points) . it was also found that 85% of the boilers had no operating instructions, and 60% of them did not have any kind of alarm. conclusions: the studied boilers had poor security conditions, mainly related to the absence of operation protocols, boiler operator training, and poor supervision by competent authorities.
Análisis de sensibilidad por la colocación de los electrodos en la electromiografía de superficie (semg)
Ramírez,Angélica; Garzón,Diego Alexander;
Revista Facultad de Ingeniería Universidad de Antioquia , 2008,
Abstract: the surface electromyography is widely used in laboratories of movement analysis due to its easy manipulation and its noninvasive character. however, this extended use generates a variation in the protocols and produces difficult to compare results [1]. in the present study, an analysis of sensitivity for the positioning of bipolar electrodes is made on three muscles of the quadriceps: vastus lateralis (vl), vastus medialis (vm) and rectus femoris (rf). the three main factors of the study are: a. the longitudinal position of electrode, b. the orientation of electrode and c. the angle of extension of the knee. additionally, the response factors are the maxima force and the rms of the emg signal. the tests were made for maxima voluntary contraction (mvc) during an isometric force. we conclude that there are differences in the emg signal when the electrodes are in different position and orientation. the best distance for the electrodes is 22.59 ± 2.84% for the vl, 29.44 ± 1.88% for the vm and 66.28 ± 0.38% for the rf from the apex of the patella. the best orientation of the electrodes is 0ofor the vl, 70ofor the vm and -20ofor the rf.
Comparación de la solución analítica de la función de producción de COBB-DOUGLAS con la obtenida por el método de mínimos cuadrado
Díaz Ossa,Wilmar A.; Giral Ramírez,Diego A.;
Tecnura , 2011,
Abstract: in this article a detailed descriptive analysis mathematica lfunction cobb-douglas production, and compared with analytical solution obtained using the least squares method. also there is a brief history of its origin, and explains a possible way as charles cobband paul douglas came to the algebraic formulation of the production function that describes the growth of the u.s. economy in the period from 1899 to 1922.
Comparación de la solución analítica de la función de producción de COBB - DOUGLAS con la obtenida por el método de mínimos cuadrado
Wilmar A. Díaz Ossa,Diego A. Giral Ramírez
Tecnura , 2011,
Abstract: In this article a detailed descriptive analysis mathematica lfunction Cobb-Douglas production, and compared with analytical solution obtained using the least squares method. Also there is a brief history of its origin, and explains a possible way as Charles Cobband Paul Douglas came to the algebraic formulation of the production function that describes the growth of the U.S. economy in the period from1899 to 1922.
Evaluación y comparación de la eficiencia de dos sistemas de incubación de huevos de Genypterus chilensis (Guichenot, 1848) Evaluation and comparison of the efficiency of two incubation systems for Genypterus chilensis (Guichenot, 1848) eggs
Rolando Vega,Miguel Pradenas,Juan Manuel Estrada,Diego Ramírez
Latin american journal of aquatic research , 2012,
Abstract: Actualmente la tendencia de la acuicultura mundial está orientada hacia la diversificación de los cultivos, principalmente de especies nativas. El congrio colorado Genypterus chilensis es un pez nativo de alta demanda gastronómica y explotación estacional que lo proyecta como candidato para el desarrollo de su tecnología de cultivo. El objetivo de este trabajo fue evaluar la eficiencia de dos sistemas de incubación de masas de huevos de G. chilensis, uno con circuito cerrado de agua (SICC) y el otro con circuito abierto (SICA); su eficiencia fue medida por el porcentaje de eclosión de huevos. Dos ensayos fueron realizados midiendo y comparando los porcentajes de fecundación y eclosión de huevos en cuatro réplicas entre los dos sistemas, encontrándose solo diferencias significativas entre los porcentajes de fecundación del bioensayo 2. El bioensayo 1 tuvo un 81% promedio de fecundación de los huevos y el porcentaje promedio de eclosión para el SICC fue 42,9 ± 34,5% y para el SICA fue 0,0 ± 0,0%. El bioensayo 2 tuvo un porcentaje promedio de fecundación de los huevos de 87,3 ± 2,6% para el SICC y 79,8 ± 3,2% para el SICA y el porcentaje promedio de eclosión para el SICC fue 27,9 ± 33,7% y para el SICA fue 4,8 ± 5,6%. Se discuten los parámetros de incubación para obtener una máxima eclosión y se entrega una proposición para mejorar el sistema SICC. El sistema de incubación con circuito cerrado de agua generó mayores sobrevivencias en los huevos de G. chilensis. The current trend in world aquaculture is towards the diversification of cultures, mainly native species. The red cusk eel Genypterus chilensis is a native Chilean species of high gastronomic demand and seasonal exploitation that is projected as a candidate for the development of farming technology. The objective of this study was to test the efficiency of two incubation systems for G. chilensis egg masses, one with a closed water circuit (SICC) and the other with an open water circuit (SICA). Efficiency was measured by the percentage of eggs hatched. Two assays were performed, measuring and comparing the percentages of egg fecundation and hatching in four replicates between the two incubation systems. Significant differences were only found between the percentages of fecundation of bioassay 2. On average, in bioassay 1, egg fecundation reached 81%, and the average of hatching for the SICC was 42.9 ± 34.5% and for the SICA was 0.0 ± 0.0%. Bioassay 2 had an average fecundation of 87.3 ± 2.6% for the SICC and 79.8 ± 3.2% for the SICA, and the average for hatching was 27.9 ± 33.7% for the SICC and 4.8
PRODUCCIóN DE BIOMASA Y EXOPOLISACáRIDOS DE Grifóla frondosa BAJO CULTIVO SUMERGIDO UTILIZANDO FUENTES DE CARBONO NO CONVENCIONALES
Paula Zapata,Diego Rojas,Carlos Fernández,David Ramírez
Revista EIA , 2007,
Abstract: Grifóla frondosa es un hongo Basidiomycete comestible y medicinal que produce polisacáridos tipo glucanos (β-1,6 y β-1,3) con actividad antitumoral e inmunomoduladora. Para el presente trabajo, el objetivo fue evaluar la incidencia de diferentes fuentes de carbono (FC) en la producción de biomasa y exopolisacári-dos (EPS), bajo condiciones de cultivo sumergido, utilizando un dise o estadístico factorial con dos factores: fuente de carbono (FC(1-7)) y medio (MB y MS). La máxima producción de biomasa micelial (21,10 ± 0,82) g/l y la máxima producción de EPS (6,53 ± 0,14) g/l se logró utilizando el medio MB suplementado con FC4. Además de lo anterior, se logró desarrollar un medio de cultivo que cumple con el objetivo de disminuir costos, de Col $18.455 a $656 por litro de medio, produciendo (14,14 ± 0,82) g/l de biomasa y (5,16 ± 0,14) g/l de EPS, utilizando el medio MS suplementando con FC4. Estos resultados abren nuevas alternativas y posibilidades en nuestro país para el desarrollo de productos a partir de esta especie con costos que estén al alcance de la población. Grifóla frondosa is a Basidiomycete fungus edible and medicinal, it produces polysaccharides such a glucans (β-1,6 and β-1,3) with anti-tumor and inmuno-stimulating activity. For this work, the aim was evaluate the incidence of different carbon sources (FC) in biomass and exo-polymer (EPS) production, under submerged culture conditions, by using a factorial statistical design with two factors: carbon source (FC(1-7)) and medium (MB and MS). The maximal yield of mycelial biomass (21,10 ± 0,82) g/l and the maximal yield in EPS (6,53 ± 0,14) g/l was achieved by using the MB medium supplemented with FC4. Besides, it was possible to develop a medium that fulfills the objective of reducing costs from $18.455 to $656 Colombian pesos for each liter of medium used, which produces (14,14 ± 0,82) g/l of biomass and (5,16 ± 0,14) g/l of EPS, using the MS medium supplemented with FC4. This result opens new alternatives and possibilities in our country for developing products of this species with cost that can be reached by population.
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