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Polvos de Especias Aromáticas para el Control del Gorgojo del Maiz, Sitophilus zeamais Motschulsky, en Trigo Almacenado
Salvadores U,Yessica; Silva A,Gonzalo; Tapia V,Maritza; Hepp G,Ruperto;
Agricultura Técnica , 2007, DOI: 10.4067/S0365-28072007000200004
Abstract: the maize weevil, sitophilus zeamais motschulsky, is considered one of the most important pests of stored grains. plant powders from nine seasoning spices were tested in the laboratory to control s. zeamais at 0,5, 1, 2 and 4% (w/w). the variables evaluated were mortality and emergence (f1) of adult insects, grain weight loss and grain germination. the repellent and fumigant effects were evaluated at concentrations of 0.5, 1, 2 and 4%; the experimental design was completely randomized, with four replicates, and the group of treatments was repeated three times. the highest mortality percentages were obtained with piper nigrum l. at 1% (83.4%), 2% (97.6%) and 4% (100%). the lowest adult insect emergence was obtained with the same treatments more capsicum annuum var. longum sendtn., cinnamomum zeylanicum blume and pimpinella anisum l. at 4% (w/w). no significant differences were recorded as regards grain weight loss and germination. all the plant powders tested had a repellent effect on sitophilus zeamais and no fumigant effect was recorded
Polvos de Especias Aromáticas para el Control del Gorgojo del Maiz, Sitophilus zeamais Motschulsky, en Trigo Almacenado Spices Powders for the Control of Maize Weevil, Sitophilus zeamais Motschulsky, in Stored Wheat
Yessica Salvadores U,Gonzalo Silva A,Maritza Tapia V,Ruperto Hepp G
Agricultura Técnica , 2007,
Abstract: El gorgojo del maíz Sitophilus zeamais Motschulsky, es considerado una de las plagas mas importantes de productos almacenados. Se evaluaron, en laboratorio, polvos vegetales provenientes de nueve especias condimentarias para el control de S. zeamais en concentraciones de 0,5; 1; 2 y 4%. Las variables evaluadas fueron mortalidad y emergencia (F1) de adultos y pérdida de peso y germinación del grano. También se evaluó el efecto repelente y fumigante a las concentraciones de 0,5; 1 y 2%. El dise o experimental fue completamente al azar, los tratamientos tuvieron cuatro repeticiones y el grupo de tratamientos fue repetido tres veces. Las mayores mortalidades se obtuvieron con Piper nigrum L. a 1% (83,4%), 2% (97,6%) y 4% (100%). Las menores emergencias de insectos adultos se obtuvieron en los mismos tratamientos más Capsicum annuum var. Longum Sendtn., Cinnamomun zeylanicum Blime y Pimpinella anisum L. al 4% (p/p). La pérdida de peso y germinación de granos no registraron diferencia significativa. Todos los polvos vegetales fueron repelentes para Sitophilus zeamais y ninguno tuvo efecto fumigante The maize weevil, Sitophilus zeamais Motschulsky, is considered one of the most important pests of stored grains. Plant powders from nine seasoning spices were tested in the laboratory to control S. zeamais at 0,5, 1, 2 and 4% (w/w). The variables evaluated were mortality and emergence (F1) of adult insects, grain weight loss and grain germination. The repellent and fumigant effects were evaluated at concentrations of 0.5, 1, 2 and 4%; the experimental design was completely randomized, with four replicates, and the group of treatments was repeated three times. The highest mortality percentages were obtained with Piper nigrum L. at 1% (83.4%), 2% (97.6%) and 4% (100%). The lowest adult insect emergence was obtained with the same treatments more Capsicum annuum var. longum Sendtn., Cinnamomum zeylanicum Blume and Pimpinella anisum L. at 4% (w/w). No significant differences were recorded as regards grain weight loss and germination. All the plant powders tested had a repellent effect on Sitophilus zeamais and no fumigant effect was recorded
Hoyos negros
Yessica Mireles Zavala
Acta Universitaria , 2012,
Abstract: Hacyan, Shahen. Los Hoyos negros y la curvatura del espacio-tiempo. México: FCE, 1998. (La Ciencia para Todos; 50).
INHIBICIóN DE LAS ACTIVIDADES PROTEOLíTICA, COAGULANTE Y HEMOLíTICA INDIRECTA INDUCIDAS POR EL VENENO DE Bothrops asper POR EXTRACTOS ETANóLICOS DE TRES ESPECIES DE HELICONIAS
PEREA?EZ J,Jaime A; JIMéNEZ,Silvia L; QUINTANA,Juan C; NU?EZ,Vitelbina; FERNANDEZ,Maritza; RESTREPO,Yessica;
Vitae , 2008,
Abstract: in colombia, bothrops asper (mapaná) inflicts at least 70 to 90% of an approximated 3.000 snakebites reported each year. for many centuries, traditional medicine has used plants for treatment of snakebites. in colombia, 60% of snakebite victims are initially attended by traditional healers or "chamanes", who use at least 100 medicinal plants species in different forms according to clinical conditions of patients. in this work, the ethanol extracts of three species of heliconiaceae family, h. latispatha benth, hemidesmus indicus petersen and h. curtispatha petersen, were examined for their possible inhibitory ability against proteolytic, coagulant and indirect hemolytic effects induced by b. asper. the first of three induced more inhibition percentage of indirect hemolytic activity than the heliconia wagneriana, as well as induced reduction of venom proteins intensity with 14 kda of molecular weight, belonging to phospholipases a2. the extract of h. latispatha showed major inhibition on the proteolytic effect induced by bothrops asper venom, as well as greater change on the protein bands with molecular weights between 95 and 110 kda, possibly belonging to proteases (metalloproteases). heliconia curtispatha showed the greatest inhibitory ability against mentioned effects, including coagulant induced by bothrops asper venom, and it did present degradation of all venom proteins , as well as it had been reported previously.
Errors and Their Mitigation at the Kirchhoff-Law-Johnson-Noise Secure Key Exchange
Yessica Saez, Laszlo B. Kish
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0081103
Abstract: A method to quantify the error probability at the Kirchhoff-law-Johnson-noise (KLJN) secure key exchange is introduced. The types of errors due to statistical inaccuracies in noise voltage measurements are classified and the error probability is calculated. The most interesting finding is that the error probability decays exponentially with the duration of the time window of single bit exchange. The results indicate that it is feasible to have so small error probabilities of the exchanged bits that error correction algorithms are not required. The results are demonstrated with practical considerations.
Marcadores plasmáticos de estrés oxidante en población mexicana sana de 31 a 60 a?os de edad
Torres-Ramos, Yessica Dorin;Sierra-Vargas, Martha Patricia;Olivares-Corichi, Ivonne María;Hicks Gómez, Juan José;
Revista del Instituto Nacional de Enfermedades Respiratorias , 2006,
Abstract: introduction: patients with asthma, copd, diabetes mellitus, kidney diseases and alzheimer syndrome, conditions associated to oxidative stress, have modifications and rupture of certain plasma biomolecules. in order to explain properly this findings, basal values in normal individuals of such biomolecules should be known. objective: to determine the basal values of some markers of oxidative stress in healthy 31 to 60 year old individuals. method: seventy seven healthy volunteers were classified into group 1, 31 to 40 years, group 2, 41 to 50 years and group 3, 51 to 60 years; the following oxidative stress markers were measured: reactive compounds to tiobarbituric acid (tbars), predisposition to oxidative stress, determination of carbonil groups, total antioxidative capacity of plasma (tacp) and enzymatic activity of paraoxonase. anova and bonferroni tests were used; a level of 0.05 was considered significant. results: croup 2 and 3 showed significant increment in tbars (8.462 ± 0.571 vs 10.34 ± 1.23μm tbars, respectively). in the predisposition to lipoper oxidation, group 3 was more susceptible, due to an increase in rcta levels (477.0 ± 16.71 μm) in comparison to group 2 (432.3 ± 25.71 μm) and 1 (320.6 ± 28.95 μm). there was no difference in the determination of carbonil groups between the groups. tacp is significantly diminished in group 2 in relation to group 1 (0.950 ± 0.071 vs 0.69 ± 0.068 units, respectively). paraoxonase's activity showed a significant increase in group 3 in relation to group 1 (0.119 ± 0.004 vs 0.072 ± 0.007 nmol p-nitrophenol/mg protein, respectively). conclusion: advancing age modifies biomolecular markers of oxidative stress; during the natural aging process, the main damage is to lipids.
PARTICIPACIóN DE LAS ESPECIES REACTIVAS DEL OXíGENO EN LAS ENFERMEDADES PULMONARES
SIERRA VARGAS, MARTHA PATRICIA;GUZMáN GRENFELL, ALBERTO MARTíN;OLIVARES CORICHI, IVONNE MARíA;TORRES RAMOS, YESSICA DORIN;HICKS GóMEZ, JUAN JOSé;
Revista del Instituto Nacional de Enfermedades Respiratorias , 2004,
Abstract: reactive oxygen species (ros) are very reactive molecules (o2?-, ho?, no? ) since they have a single and unpaired electron in the last orbital (free radical) which confers them physical instability. free radical precursors such as h2o2 , hono2- are considered ros. these species are important in the physiological processes. when ros production exceeds the inactivation mechanisms, oxidative stress takes place. this stress is characterized by molecular and cellular damage which predisposes to or modifies chronic-degenerative diseases. among pulmonary diseases in which ros participation has been proved are ards, copd and asthma. the aim of this paper was to analyze the mechanisms of oxidative stress that lead to those illnesses.
INCORPORACIóN DE COMPUTADORES EN ESCUELAS RURALES: ESTUDIOS DESCRIPTIVO DE CUATRO CASOS DEL SUR DE CHILE
Arancibia Herrera,Marcelo; Carrasco Rojas,Yessica;
Estudios pedagógicos (Valdivia) , 2006, DOI: 10.4067/S0718-07052006000200001
Abstract: this article presents results of one research whose main goal was to describe the transformations produced in the interaction of education agents after de computer incorporation. an ethnographic approach is used, based on observation techniques not taking part of the pedagogical practices, through informatics resources and extensive interviews to teachers and students from four elementary schools of the province of valdivia, selected for the research. the main findings were: the use of the computers depends on the perception of teachers concerning their effectivity upon learning; training received by teachers is identified as vital to achieve an innovative use. three cases are classified as transmitter/reproducer and one as practical/situational (bautista 1994). finally, the computer is used by students mainly incorporated to classes activities from differents subjects. the main conclusion is that the informatics resources in a rural school presents higher possibilities to be effectively used as curricular material supporting the learning process, mainly since the children from these communities know this technology for the first time at school; nevertheless, its use becomes inefficient due to inexperience and low training of teachers concerning innovation using i.c.t.
Desarrollo de plantaciones experimentales jóvenes de Fitzroya cupressoides establecidas en el arboreto de la Universidad Austral de Chile, Valdivia
Gerding,Víctor; Rivas T,Yessica;
Bosque (Valdivia) , 2006, DOI: 10.4067/S0717-92002006000200010
Abstract: two experimental plantations of fitzroya cupressoides (alerce), established at the arboretum of universidad austral de chile (valdivia, 39°48?s and 73°14?w; 50 m asl) in 1994, were evaluated in may 2004 in order to assess its development ex situ through an integrated diagnosis. the plants had been produced from seeds in a three-year-nursery period (cordillera de la costa de valdivia, coastal mountain range, valdivia). in 1998 approximately 50% of the trees were transplanted to an adjacent area with 70% regeneration coverage of acacia melanoxylon, being frequently cut for clearance (stand a). the remainder on the grassland corresponded to stand b. the distance between trees was 4 x 4 m. the climate is warm and rainy with mediterranean influence; the soil has a loamy silty texture with no structure or drainage boundaries, rich in organic matter, strongly acid and with low phosphorous availability. alerce shows adequate climatic and edaphic adaptation, and good nutritional and sanitary state. stand b reached a height greater (p < 0.05) than stand a (289 vs. 260 cm), but none of them was different in crown diameter (181 vs. 167 cm), dhb (4.1 vs. 3.8 cm) and survival (76%).
Diferenciación poblacional en la talla corporal de la liebre de Tehuantepec (lepus flavigularis)
Yessica Rico,Consuelo Lorenzo,Sergio López
Acta zoológica mexicana , 2008,
Abstract: En este trabajo se analizaron las diferencias en la talla corporal de tres poblaciones de la liebre de Tehuantepec, Lepus flavigularis, en el Istmo de Tehuantepec, Oaxaca, México. Los análisis de regresión linear entre la longitud total del cuerpo y el peso corporal fueron estadísticamente significativos para las hembras y machos de la población de Santa María del Mar, y para los machos de la población de Montecillo Santa Cruz, pero no para las hembras. Asimismo, la relación no fue significativa para los machos de Aguachil. El análisis de varianza indicó que las liebres de Santa María del Mar tienen mayor longitud corporal que las liebres de Aguachil y Montecillo Santa Cruz. Los resultados encontrados coincidieron con los datos genéticos que separan a las liebres de Santa María del Mar en un grupo distinto del resto de las poblaciones. Es posible que las diferencias en la longitud corporal estén relacionadas con las características ecológicas del hábitat que predominan en cada una de las poblaciones de liebres.
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