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Search Results: 1 - 10 of 209833 matches for " Claudia E. Hernández-Olmos "
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Evaluación de insecticidas sintéticos sobre adultos de Metamasius spinolae (Coleoptera: Curculionidae) procedentes de Tlalnepantla, Morelos Evaluation of synthetic insecticides on Metamasius spinolae (Coleoptera: Curculionidae) adults from Tlalnepantla, Morelos
Claudia Cerón-González,Esteban Rodríguez-Leyva,J. Refugio Lomeli-Flores,Claudia E. Hernández-Olmos
Revista mexicana de ciencias agrícolas , 2012,
Abstract: El picudo del nopal, Metamasius spinolae (Gyllenhal), es una de las plaga más importantes en nopal verdura (Opuntia ficus-indica (L.) Miller) en México y en especial en Tlalnepantla, Morelos, la segunda región de importancia en la producción de este cultivo con alrededor de 2 500 ha. Tanto adultos como larvas causan da o al cultivo, la larva realiza galerías en las pencas maduras y el adulto da a los márgenes de los nopalitos. A pesar de que no existen plaguicidas autorizados en México para su control, este hecho no limita a los productores para el uso de productos químicos sin conocer su efectividad. Por esta razón, en este trabajo se evaluó la efectividad de ocho insecticidas pertenecientes a dos grupos, organofosforados y piretroides, sobre adultos de este curculiónido. Las pruebas de laboratorio y campo realizadas durante 2007 mostraron que el Malatión causó una mortalidad similar a otros productos del mismo grupo que son más tóxicos (Paratión Metílico y Metidatión). Por otro lado, sólo un insecticida piretroide (Permetrina), proporcionó una mortalidad cercana a 86%, en comparación con los tres restantes (Cipermetrina, Deltametrina y Fenvalerato) que lograron mortalidades menores a 20%. Existió una respuesta diferencial del sexo del insecto a los insecticidas, las hembras mostraron menor susceptibilidad que los machos a algunos productos, tales como Diazinón, Permetrina y Cipermetrina. Este es el primer reporte formal de la evaluación de productos químicos en este insecto y se discuten algunos problemas relacionados con su manejo. The cactus weevil, Metamasius spinolae (Gyllenhal), is one of the most important pests in prickly pear (Opuntia ficus-indica (L.) Miller) in Mexico and especially in Tlalnepantla, Morelos, the second most important region in the production of this crop, with about 2 500 ha. Both adults and larvae cause damage to this crop; larvae make galleries in mature pads and adults damage young pads of the cactus. Although there are no authorized pesticides for its control in Mexico, this fact does not stop farmers from using synthetic insecticides without knowing their effectiveness. For this reason, this study evaluated the effectiveness of eight pesticides in two chemical groups, organophosphates and pyrethroids, on adults of this insect. The laboratory and field tests conducted in 2007 showed that malathion caused a mortality similar to other more toxic products in the same group (Methyl Parathion and Methidathion). On the other hand, only a pyrethroid insecticide (Permethrin) provided a mortality rate close to 86%, in comparison
Evaluación de insecticidas sintéticos sobre adultos de Metamasius spinolae (Coleoptera: Curculionidae) procedentes de Tlalnepantla, Morelos
Cerón-González, Claudia;Rodríguez-Leyva, Esteban;Lomeli-Flores, J. Refugio;Hernández-Olmos, Claudia E.;Pe?a-Martínez, Rebeca;Mora-Aguilera, Gustavo;
Revista mexicana de ciencias agrícolas , 2012,
Abstract: the cactus weevil, metamasius spinolae (gyllenhal), is one of the most important pests in prickly pear (opuntia ficus-indica (l.) miller) in mexico and especially in tlalnepantla, morelos, the second most important region in the production of this crop, with about 2 500 ha. both adults and larvae cause damage to this crop; larvae make galleries in mature pads and adults damage young pads of the cactus. although there are no authorized pesticides for its control in mexico, this fact does not stop farmers from using synthetic insecticides without knowing their effectiveness. for this reason, this study evaluated the effectiveness of eight pesticides in two chemical groups, organophosphates and pyrethroids, on adults of this insect. the laboratory and field tests conducted in 2007 showed that malathion caused a mortality similar to other more toxic products in the same group (methyl parathion and methidathion). on the other hand, only a pyrethroid insecticide (permethrin) provided a mortality rate close to 86%, in comparison to the remaining three (cypermethrin, deltamethrin and fenvalerate) which caused a mortality of under 20% mortality. there was a differential response of the sex of the insect to insecticides, in which females were less susceptible than males to some products, such as diazinon, permethrin and cypermethrin. this is the first formal report of the evaluation of synthetic insecticides in this insect and we discuss some issues related to management.
Successive duopoly under moral hazard: Will incentive contracts persist?
Marta Fernández-Olmos,Jorge Rosell Martínez,Manuel Antonio Espitia Escuer,Luz María Marín Vinuesa
Journal of Industrial Engineering and Management , 2009, DOI: 10.3926/jiem..v2n1.p208-229
Abstract: The central purpose of this paper is to examine the incentive contract as an equilibrium phenomenon. We analyse a model of vertical differentiation in which we deal with the strategic role of the competitor’s decisions in a successive duopoly. Is it better for a processor to offer an incentive contract to an upstream producer or the spot market? We determine the equilibrium of a game in which the processors simultaneously decide whether to offer an incentive contract or to continue at the spot market to acquire their input. Our results show that under successive duopoly, offering an incentive contract constitutes the unique equilibrium solution, which highlights the incentive contract persistence.
Respiratory Mechanics and Plasma Levels of Tumor Necrosis Factor Alpha and Interleukin 6 Are Affected by Gas Humidification during Mechanical Ventilation in Dogs
Claudia Hernández-Jiménez, Rogelio García-Torrentera, J. Raúl Olmos-Zú?iga, Rogelio Jasso-Victoria, Miguel O. Gaxiola-Gaxiola, Matilde Baltazares-Lipp, Luis H. Gutiérrez-González
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0101952
Abstract: The use of dry gases during mechanical ventilation has been associated with the risk of serious airway complications. The goal of the present study was to quantify the plasma levels of TNF-alpha and IL-6 and to determine the radiological, hemodynamic, gasometric, and microscopic changes in lung mechanics in dogs subjected to short-term mechanical ventilation with and without humidification of the inhaled gas. The experiment was conducted for 24 hours in 10 dogs divided into two groups: Group I (n = 5), mechanical ventilation with dry oxygen dispensation, and Group II (n = 5), mechanical ventilation with oxygen dispensation using a moisture chamber. Variance analysis was used. No changes in physiological, hemodynamic, or gasometric, and radiographic constants were observed. Plasma TNF-alpha levels increased in group I, reaching a maximum 24 hours after mechanical ventilation was initiated (ANOVA p = 0.77). This increase was correlated to changes in mechanical ventilation. Plasma IL-6 levels decreased at 12 hours and increased again towards the end of the study (ANOVA p>0.05). Both groups exhibited a decrease in lung compliance and functional residual capacity values, but this was more pronounced in group I. Pplat increased in group I (ANOVA p = 0.02). Inhalation of dry gas caused histological lesions in the entire respiratory tract, including pulmonary parenchyma, to a greater extent than humidified gas. Humidification of inspired gases can attenuate damage associated with mechanical ventilation.
Seguimiento de Egresados en Tres Programas de Maestría en una Escuela del Instituto Politécnico Nacional en México
Hernández,Claudia A; Tavera,María E; Jiménez,Martha;
Formación universitaria , 2012, DOI: 10.4067/S0718-50062012000200006
Abstract: the results of a study to know the improvement in labor and earnings in their jobs of persons graduated from masters programs are presented. the study considered three master programs of five generations of the school of higher education belonging to the national polytechnic institute in mexico city. the method used was quantitative, descriptive and transversal. a questionnaire designed to take into account basic scheme factors of graduates proposed by the mexican national association of universities and higher education institutions was used. in conclusion, the graduates from these three master degrees improved their labor situation after concluding their studies, while the increase in salaries varies depending on the program they followed.
EVALUACIóN DE LA ACTIVIDAD LEISHMANICIDA DE LOS EXTRACTOS ETANóLICOS DE Rollinia rufinervis SOBRE Leishmania chagasi
HERNáNDEZ C.,Jorge E.; TENORIO V.,José L.; ROJAS,Claudia M.; VALLEJO,Gustavo A.;
Vitae , 2005,
Abstract: in this study the bioactivity of the fractions obtained from the ethanolic extracts of the leaves, of the trunk bark and of the root bark of rollinia rufinervis (annonaceae) is evaluated. it is found that they show cytotoxic activity and that the presence of acetogenins can cause the antiparasitaire activity. the fractions are tested at concentration between 0.095 "g/ml and 100 "g/ml against promastigotes of leishmania chagasi, evaluating the parasite mobility after 72 hours. the effect of the fractions is contrasted with the mediun schneider- drosófila without extract and with glucantime?, used as control. the rollinia rufinervis fractions of: ethyl acetate of the root, petroleum ether of the bark, ethyl acetate of the bark and ethyl acetate of the leaves present leishmanicidal activity. the last fraction has the largest activity causing appreciable or total immobility of the parasites during the experiment. probably ?-sitosterol is isolated from this fraction.
EVALUACIóN DE LA ACTIVIDAD LEISHMANICIDA DE LOS EXTRACTOS ETANóLICOS DE Rollinia rufinervis SOBRE Leishmania chagasi EVALUATION OF THE LEISHMANICIDAL ACTIVITY OF THE ETHANOLIC EXTRACTS OF Rollinia rufinervis ON Leishmania chagasi
Jorge E. HERNáNDEZ C.,José L. TENORIO V.,Claudia M. ROJAS,Gustavo A. VALLEJO
Vitae , 2005,
Abstract: En éste estudio se evalúa la bioactividad de las fracciones obtenidas de los extractos etanólicos de las hojas, de la corteza del tronco y de la corteza de la raíz de Rollinia rufinervis (Annonaceae), las cuales presentan actividad citotóxica y se detecta la presencia de las acetogeninas, que pueden ser responsables de la actividad antiparasitaria. Las fracciones son probadas a concentraciones entre 0.095 μg/mL y 100 μg/mL contra promastigotes de Leishmania chagasi, evaluando la movilidad de los parásitos a las 72 horas. El efecto de las fracciones es contrastado con el medio Schneider-Drosófila sin extracto y con glucantime , utilizados como control. Las fracciones de Rollinia rufinervis de: acetato de etilo de raíz, éter de petróleo de corteza, acetato de etilo de corteza y acetato de etilo de hojas, presentan actividad leishmanicida. La última fracción es la de mayor actividad causando inmovilidad apreciable o total de los parásitos a lo largo del experimento. De ella se aisló posiblemente el β-sitosterol. In this study the bioactivity of the fractions obtained from the ethanolic extracts of the leaves, of the trunk bark and of the root bark of Rollinia rufinervis (Annonaceae) is evaluated. It is found that they show cytotoxic activity and that the presence of acetogenins can cause the antiparasitaire activity. The fractions are tested at concentration between 0.095 "g/mL and 100 "g/mL against promastigotes of Leishmania chagasi, evaluating the parasite mobility after 72 hours. The effect of the fractions is contrasted with the mediun Schneider- Drosófila without extract and with glucantime , used as control. The Rollinia rufinervis fractions of: ethyl acetate of the root, petroleum ether of the bark, ethyl acetate of the bark and ethyl acetate of the leaves present leishmanicidal activity. The last fraction has the largest activity causing appreciable or total immobility of the parasites during the experiment. Probably -sitosterol is isolated from this fraction.
Biomarcadores séricos del estado de salud en jóvenes universitarios de acuerdo a su nivel de actividad física
Raimundo E Cordero,Daniela Pagavino,Claudia I Hernández,Merlyn I Contrera
Revista de la Facultad de Medicina , 2008,
Abstract: El objetivo del estudio fue categorizar el riesgo a sufrir enfermedades cardiometabólicas a partir del uso de biomarcadores del metabolismo de los lípidos y proteínas en estudiantes deportistas o sedentarios de la Universidad Central de Venezuela. Se determinó en suero de 103 sujetos (55 deportistas y 48 sedentarios), por método colorimétrico: creatinina (Cr), proteína total (Pt), albúmina (Al), triglicéridos (Tg), colesterol total (Col-T), y lipoproteínas de alta densidad (HDL-C), mientras que la de baja densidad (LDL-C) se obtuvo por la fórmula de Friedewald y las globulinas por la resta entre Pt y Al. Los niveles séricos de los biomarcadores se encontraron dentro de los rangos de referencia. Sólo en las HDL-C y las globulinas no se observaron diferencias significativas entre sedentarios y deportistas. En estos últimos se consiguieron los Tg notablemente bajos, mientras que el Col-T fue alto, principalmente a expensa de la LDL-C. En este grupo, la condición de los diferentes componentes del perfil lipídico y del índice Col-T/HDL-C estuvieron influenciadas por una distorsión transitoria de la lipemia, posiblemente asociada a procesos inflamatorios mediados por respuesta inmune que se presenta en actividad física de alta intensidad. Se detectó baja proporción de HDL-C elevado en sedentarios y deportistas. Apenas 2,1 % de los sedentarios y 1,0 % de la muestra total tuvieron albúmina sérica baja, la cual está asociada a riesgo incrementado a sufrir enfermedades cardiovasculares (ECV). Una peque a proporción de la muestra evaluada pudiera ser susceptible a sufrir algún tipo de enfermedad cardiometabólica. The main objective of this study was to categorize the risk of suffering of cardiometabolic disease. For this, lipids and proteins metabolic biomarkers were used on sporting or sedentary students from Universidad Central de Venezuela. The following parameters were determined by colorimetric methods: Creatinine (Cr), Total protein (Tp), Albumin (Al), Triglycerides (Tg), Total cholesterol (T-Cho) and High density lipoproteins (HDL-C). The low density lipoproteins (LDL-C) were calculated by using the Friedewald formulae and globulins values were obtained by subtracting Tp from Al. The seric biomarkers levels were in the normal reference ranges. There were not significant differences on the HDL-C and globulins values between sporting and sedentary students. The sporting group showed very low Tg levels, with high T-Cho, due mainly to LDL-C. In this group, the conditions of the different components of the lipidic profile and T-Cho/HDL-C rate were influenced by
Difracción De Luz Con Momento Angular Orbital Por Un Axicon
ángela M. Guzmán,Claudia P. Barrera P.,Jefferson Flórez G.,Florencio E. Hernández
Bistua : Revista de la Facultad de Ciencias Básicas , 2009,
Abstract: Estudiamos aquí el problema de la difracción escalar de Fresnel por un axicón iluminado con haces de Laguerre-Gauss ( , , ) pl u r z con modo radial p arbitrario y momento angular orbital l, cuya dirección de propagación coincide con el eje del axicón. Para obtener expresiones analíticas del campo difractado utilizamos una expansiónen serie de Taylor de la transmitancia del axicón en la aproximación de elemento óptico delgado y transparente, y la transformada de Hankel de orden l. Se presentan resultados de los patrones de difracción para diferentes valores del momento angular de la luz en función de la distancia de propagación. El axicón no altera el momento angular de la luz ni discrimina entre ondas de helicidad positiva y negativa, pero introduce una superposición de modos radiales con el mismo momento angular.
Inventario de la Tortuga Arrau, Podocnemis expansa (Schweigger, 1812) en Zoológicos de Venezuela.: Valores Referenciales del Hemograma y la Bioquímica Sérica.
Martínez,Enrique O; Hernández,Omar E; Boede,Ernesto O; Pe?aloza,Claudia; Rodríguez,Alberto E;
Revista Científica , 2007,
Abstract: the arrau sideneck turtle (podocnemis expansa) is the biggest fresh water hard shell chelonian of the world, which has been subjected to an irrational hunting to the point of being in the verge of extinction. among the diverse strategies of conservation of this species, it has been considered the possibility to employ the zoos that kept this species in their collections as ex situ breeding centers, and also for raising wild born hatchlings until one year of age for re-introduction purposes. in such a sense it was carried out an inventory of the captive zoo specimens where we counted 101 adult animals (94 females and 7 males). the inspection of the exhibits gave as a result that most of the facilities requires modifications, also in habitat conditions, animal husbandry, research and public information in order to reach mentioned aims. blood samples were collected from the neck of some turtles, with the purpose to obtain hematological and blood chemistry reference values, as an essential step to estimate its health condition. the results obtained by the observation under microscope and a blood automatic analizer were: packed cell volume 34.30%, erythrocytes 470 x 109/l, leukocytes 3.08 x 109/l, lymphocytes 34.00%, monocytes 1.33%, heterophils 63.50%, total proteins 43.7 g/l, albumin 19.2 g/l, globulins 19.6 g/l, total bilirubine 0.004 g/l, direct bilirubin 0.001 g/l, uric acid 0.012 g/l, urea nitrogen 0.366 g/l, glucose 0.485 mg/l, iron 1.088, mg/l, calcium 0.093 g/l, sodium 134.78 mmol/l, potassium 4.26 mmol/l, chloride 104.38 mmol/l, phosphorus 0.033 g/l, ck 1673 u/l, ast 26.50 u/l, alt (6.80 u/, and alp 154.60 u/l),respectively.
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