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Search Results: 1 - 10 of 328783 matches for " Moisés Carrascal Medina "
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Actividad larvicida de extractos etanólicos de Tabernaemontana cymosa y Trichilia hirta sobre larvas de estadio III y IV de Aedes aegypti (Diptera: Culicidae) Larvicidal activity of ethanol extracts of Tabernaemontana cymosa and Trichilia hirta against III and IV stage larvae of Aedes aegypti (Diptera: Culicidae)
Fredyc Díaz Castillo,Sandra Marcela Morelos Cardona,Moisés Carrascal Medina,Yina Pájaro González
Revista Cubana de Plantas Medicinales , 2012,
Abstract: Introducción: el mosquito Aedes aegypti es el principal vector de los virus del dengue y la fiebre amarilla. Una de las formas actuales para combatir estas enfermedades es el control del vector. Sin embargo, los problemas causados por los insecticidas sintéticos y la resistencia adquirida por los mosquitos, hacen cada vez más difícil esta lucha. Las plantas constituyen una fuente alternativa al uso de insecticidas sintéticos. Objetivos: evaluar la actividad larvicida para el mosquito Aedes aegypti, de los extractos etanólicos y fracciones activas, de diferentes órganos vegetales de las especies Trichilia hirta L. y Tabernaemontana cymosa Jacq. Métodos: en este estudio se utilizaron larvas de Aedes aegypti en estadios III y IV. Los extractos etanólicos totales se obtuvieron por maceración del material vegetal seco y molido, durante una semana y posterior secado a presión reducida con un rotoevaporador. La obtención de fracciones y subfracciones, se realizó por cromatografía de columna abierta, usando solventes de diferentes polaridades. La actividad larvicida se evaluó bajo protocolos recomendados por la Organización Mundial de la Salud. Resultados: los extractos etanólicos de corteza de Trichilia hirta y flores, corteza y hojas de Tabernaemontana cymosa, no mostraron actividad larvicida. El extracto de semillas de Trichilia hirta mostró una actividad moderada con una CL50 y CL90 de 219,2 y 331,4 mg/L respectivamente. El extracto etanólico de semillas de Tabernaemontana cymosa, la fracción F008 y la subfracción F011, mostraron una buena actividad larvicida con CL50 de 35,1; 20,9, y 14,98 mg/L, respectivamente. Conclusiones: según los resultados, se consideró como promisorio el extracto de semillas de Tabernaemontana cymosa para la obtención de metabolitos secundarios con actividad larvicida. Introduction: Aedes aegypti is the main vector of dengue and yellow fever. One way to combat these diseases today is the vector control. However, the problems caused by synthetic insecticides and the acquired resistance by mosquitoes, turn this control into a more difficult struggle every day. The plants offer an alternative source to the use of synthetic insecticides. Objectives: the objective of this study was to evaluate the larvicidal activity of the ethanol extracts and active fractions of different organs of Trichilia hirta L. and Tabernaemontana cymosa Jacq. Methods: in this study, Aedes aegypti larvae in III and IV stages were used. The total ethanol extracts were obtained by maceration of dried and ground plant material for a week and then dried at reduced p
Effect of Cedar Extract (Cedrela odorata L.) on the Termite (Reticulitermes spp.)  [PDF]
Leopoldo Partida Ruvalcaba, Karely Guadalupe Monjardín Armenta, Tomás Díaz Valdés, Teresa de Jesús Velázquez Alcaraz, Felipe Ayala Tafoya, Raymundo Medina López, Moisés Gilberto Yá?ez Juárez
Agricultural Sciences (AS) , 2017, DOI: 10.4236/as.2017.84019
Abstract: For knowing the effect that causes the extract from the leaves of the cedar (Cedrela odorata L.) in termites (Reticulitermes sp.) that affecting rooms, libraries, racks, fence posts and all articles wood source, considering the hypothesis that the extract from the leaves of the cedar is a substance that it makes termites die at a certain time, which makes it possible to use the extract as a biological insecticide that does not harm the environment and influencing the sustainable management of the rooms and many articles wood source. Termites were reared in a greenhouse in susceptible consumption and suitable for reproduction wood, of where the termites were collected and placed in petri dishes toguether with the remains of wood that contained. The application of the extract was done with a manual atomizer, sprinkling it on termites and wood waste, using 20 mL per petri dish and then counted the seconds until termites immovilized or dead in a 100%. Cedar extract acted as insecticide on termites but of all doses tested 5.0 g of leaves per 500 mL of water was the that caused the termites died in a few seconds after application under laboratory conditions.
Aspectos agronómicos para la producción de anís de monte (Tagetes filifolia LAG.) En temporal en Ocuituco, Morelos
Campos Mu?iz, Moisés;Medina Pitalúa, Juan L.;Serrato Cruz, Miguel A.;
Revista fitotecnia mexicana , 2010,
Abstract: agronomic aspects of irish lace marigold (tagetes filifolia lag., anise) as new crop for rainfall or dry farming conditions at ocuituco, morelos, méxico, were evaluated. two experiments were conducted. three sow densities (1, 2 and 3 g of seed/m2), two herbicides (metribuzine 0.12 kg ha-1 and linuron 0.35 kg ha-1 at pre-and postemergence, both applied in mixtures with metholachlor 1.35 kg ha-1 for preemergence and with sethoxydim 0.27 kg ha-1 for postemergence) and two soil textures (clayey and sandy) were evaluated regarding anise and weed plants establishment and anise plants growth for experiment 1. for experiment 2, fertilizer doses (30 and 60 n; 25 k; 70 p; 30:70 and 60:70 np; 75:75:20 and 125:125:50 npk) were evaluated on anise plants growth. more anise plants (p ≤ 0.05) became established on sandy soil (32 plants) than on the clayey one (27 plants), and weed plants and anise fresh weight plants increased (4 plants and 529 g m-2) on the clay soil than on the sandy one (2 plants and 445 g m-2). by increasing plant density the number of anise plants (11, 34 and 43 plants) and their respective fresh weight (414, 504 and 542 g m-2) also increased (p ≤ 0.05) but weed density (4, 3 and 2 plants) and canopy diameter of anise plant (15, 13 y 12 cm) decreased. preemergence herbicides inhibited both anise (2 to 4) and weed (one) plants compared to the control with no-herbicide (51 and 12 plants, respectively). postemergence herbicides allowed anise plants to establish (43 to 46 plants) and weed plants to be controlled (one plant). the fertilizer trial showed that the npk doses of 125-125-50, 60-30-0 and 60-0-0 were better (p ≤ 0.05) than the non fertilized treatment, interms of plant height, canopy diameter and fresh weight of anise plants.
Greenness, Plant Height and Yellow Berry of the Wheat Grain in Response to Paclobutrazol  [PDF]
Agustín Zárate Márquez, Juan Francisco Ponce Medina, Leopoldo Partida Ruvalcaba, Felipe Ayala Tafoya, Moisés Gilberto Yánez Juárez, Teresa de Jesús Velázquez Alcaraz, Raymundo Medina López
Open Access Library Journal (OALib Journal) , 2015, DOI: 10.4236/oalib.1101581
Abstract: To know the response of the wheat in the greenness, plant height and grain with yellow berry, paclobutrazol (PBZ) was applied to the foliage of the cultivars “Cachanilla F-2000”, “Yécora F-70” and “Yécora Red”. Doses were 0 (control), 50, 100, 150, 200, 250, 300 and 350 mg of PBZ L1 of water, which were applied only once with a hand pump. The experimental design was a randomized complete block with four replications; experimental units of four rows of 20 m long, which were fertilized with 364 kg·N·ha1 more 56 kg of P, were applied in pre-seeding. In “Cachanilla F-2000” greenness, the maximum increase (7.2%) was achieved with 100 mg of PBZ L1 of water. In “Yécora F-70” was 12.2% with 300 mg, and in “Yécora Red” was 19.1% with 50 mg of PBZ. In “Cachanilla F-2000” height decreased 6.0%, 6.3%, 6.3%, 9.4%, 10.7%, 10.9% and 13.0% with 50, 100, 150, 200, 250, 300 or 350 mg of PBZ, compared with the control. In “Yécora F-70” the largest decrease (10%) occurred with 150 mg of PBZ, while in “Yécora Red” height decreases ranged from 7.9% - 17.0% with doses of 50 - 350 mg. The yellow berry decreased from 48.5% - 74.4% in “Cachanilla F-2000”, and to zero in “Yécora F-70” and “Yécora Red”. These results indicate that PBZ can be used to increase greenness and photosynthesis to improve the quality of the grain of flour and durum wheat.
Estimation of Fracture Toughness by Testing Notched Fracture Specimens and Applying the Theory of Critical Distances
S. Cicero,V. Madrazo,I. A. Carrascal
ISRN Materials Science , 2012, DOI: 10.5402/2012/689386
Estimation of Fracture Toughness by Testing Notched Fracture Specimens and Applying the Theory of Critical Distances
S. Cicero,V. Madrazo,I. A. Carrascal
ISRN Materials Science , 2012, DOI: 10.5402/2012/689386
Abstract: This paper applies a methodology that allows the fracture toughness of a given material to be estimated by testing notched fracture toughness specimens and applying the Theory of Critical Distances, which requires the elastic stress field at the notch tip to be determined by finite elements simulation. This methodology, which is not intended to substitute any standardised fracture characterisation procedure, constitutes an alternative in those situations where pre-cracking processes may be too time-consuming, too expensive or, simply, cannot be performed. It comprises testing two notched specimens with different notch radii, defining the corresponding stress fields at fracture by using finite elements analysis, and applying the Theory of Critical Distances in order to calibrate the material’s critical distance and to apply the corresponding apparent fracture toughness formulation. The methodology has been applied to two different materials, PMMA and Al7075-T651, and the results have proven that, as long as the Theory of Critical Distances has been applied within its validity range, the fracture toughness estimations are highly accurate. 1. Introduction The experimental obtainment of the fracture toughness ( ) of a given material is generally performed following well-known international standards (e.g., [1–3]). The tests basically consist in applying an increasing quasistatic load to fracture toughness specimens (generally Compact or Single-Edge Bend specimens [1–3]) until the final fracture takes place, and the corresponding standard provides comprehensive guidance on how to proceed with the obtained test data in order to derive the fracture toughness value. The tests are, therefore, quite simple. However, these tests involve time-consuming preparation of specimens, which includes machining and, above all, fatigue precracking. The latter requires the use of dynamic machines and the careful application of variable loads until a certain crack is obtained. Any problem (e.g., overload) during the precracking process may induce excessive plasticity on the crack tip, and the specimen becomes useless. Therefore, considering that because of these precracking processes, ordinary fracture toughness tests may be rather time consuming (and thus, expensive), requires the use of expensive, specific dynamic machines, and is susceptible to unexpected events causing the uselessness of specimens, it is here considered of interest to propose alternative fracture toughness characterisation methodologies that avoid the need for precracking processes. With this objective and
Consideraciones taxonómicas de Callistochiton pulchellus (Gray, 1828) (Mollusca, Placophora) en Iquique, norte de Chile
Aguilera,Moisés A.;
Investigaciones marinas , 2005, DOI: 10.4067/S0717-71782005000200008
Abstract: information is presented on taxonomic traits of callistochiton pulchellus (gray, 1828) collected at thirteen sites between iquique (20°12's-70°09'w) and pabellón de pica (20°54's-70°08'w) in the north of chile. sampling sites were at least one km apart. the species was found at only three of the thirteen sampling sites (23%), and only underneath boulders sunken in sand. a new southern limit for this species was recorded in chanavayita, 54 km south of iquique. the most important characteristics of its habitat are presently discussed, as well as the the most relevant morphological differences of this species in comparison with calloplax vivipara (plate, 1902) which it closely resembles in form and tegmental ornamentation. c. pulchellus had a greater number of radial lines on the cephalic plate (? 12) than c. vivipara (? 9). it was also noted that the central plates in the former species were more rectangular than those of the latter species
Cirripedios en la dieta del molusco herbívoro Chiton granosus Frembly, 1827 (Mollusca, Placophora) presente en el intermareal rocoso de Iquique, norte de Chile
Aguilera,Moisés A;
Investigaciones marinas , 2005, DOI: 10.4067/S0717-71782005000100008
Abstract: preliminary quantitative information is given on the presence of barnacle cyprids and post-metamorphic stages in the diet of the molluscan grazer chiton granosus frembly 1827 (mollusca: placophora) sampled at iquique, chile. in december 2000, we observed the presence of barnacle cyprids and post-metamorphic stages at a high relative percentage of abundance (n = 30, 54,1% and 39,9%, respectively) and they were frequent in all of the individuals analyzed. moreover, a high frequency of ocurrence of cyprid larvae (f% = 67) was recorded in the distal portion of the intestine; of these larvae, 15 were observed with signs of vital activity (appendage movement) in 45% of all the stomachs analyzed. ingestion of barnacle cyprids and post-metamorphic stages was observed at a high frequency throughout the five months of the study (n = 10, 96% ± 6,5 and 78% ± 23,6)
Las ideas de Bruner: ?De la revolución cognitiva ? a la ?revolución cultural?
Guilar,Moisés Esteban;
Educere , 2009,
Abstract: this article highlights two periods in the life and work of american psychologist jerome s. bruner. the first coincides with his staying at harvard (1945-1972) which we could call his cognitive revolution era? and a second with his teaching done at oxford (1972-1979) which leads to his current times in the new york law school. this is what we call his ?cultural revolution era.? on both periods in bruner?s biography there are highlighted contributions done by him that have been a landmark in the development of the science of education in the 20ieth century and current times. the ?spiral curriculum?, the ?scaffolding?, the #educational reform? or the ?reciprocal teaching? are notions described in this article.
Historia Crítica , 2004,
Abstract: during the hispanic colonial period, ufe in the city or in the pólice referred to the need for public and prívate control on the part of authorities in the lndian territories. it was a question of living together to the sound of the bell, congregated in an orderly manner, around or cióse to a church. likewise, the neighborhood not only exerted control over the neighbors, but over the authorities as well, in the defense of morality, justice, and the common good. the pólice fund of the general archive of the nation illustrates this point with respect to specific cases, either of violation or of fulfillment of the norms, and facilitates comprehension of the reasons for which the authorities were anxious to live out their lives on good terms in the city. good order was an everyday issuer, a question of daily ufe with a very broad field of action.
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