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Search Results: 1 - 10 of 373414 matches for " Pérez Alemán "
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Respuesta fisiológica y bioquímica de Stylosanthes guianensis cv. CIAT-184 y Centrosema molle al estrés por cloruro de sodio Physiological and biochemical response of Stylosanthes guianensis cv. CIAT-184 and Centrosema molle to sodium chloride stress
Leticia Fuentes,Y Pérez,Silvia Alemán,Daynet Sosa
Pastos y Forrajes , 2010,
Abstract: Se realizó un estudio sobre el efecto de diferentes concentraciones de cloruro de sodio (NaCl) en plántulas de Stylosanthes guianensis cv. CIAT-184 y Centrosema molle, cultivadas en tierra vegetal. A los 15 días posteriores al tratamiento se determinaron la masa fresca, la masa seca, la relación raíz-brote y la distribución de la biomasa, así como la concentración de fenoles solubles, ligados a la pared y totales, además de la clorofila a, b y total. En ambos cultivares las raíces fueron los órganos más afectados con relación a la masa fresca y hubo un decrecimiento de la masa seca a elevadas concentraciones de NaCl. La relación raíz-brote mostró un aumento a 200 mM de NaCl en S. guianensis, mientras que no se observaron cambios significativos en C. molle. En la medida que la concentración de NaCl se elevó, la concentración de fenoles solubles aumentó sensiblemente en las raíces de ambas especies, así como los fenoles totales; mientras que en las hojas sólo se observaron aumentos en los niveles de fenoles solubles en S. guianensis. La concentración de clorofila a y total disminuyó significativamente a 200 mM de NaCl en ambos cultivares con relación al control. Los niveles de clorofila b disminuyeron en C. molle a 200 mM y se mantuvieron constantes en S. guianensis. El índice de estabilidad clorofílica mostró diferencias altamente significativas en C. molle (-8,154 y 269,1 para 100 y 200 mM de NaCl), a diferencia de S. guianensis que presentó una mayor estabilidad (20,47 y 31,37). La relación clorofila a/b decreció en Centrosema y no se observaron diferencias entre los tratamientos en Stylosanthes. A study was conducted on the effect of different concentrations of sodium chloride (NaCl) on seedlings of Stylosanthes guianensis cv. CIAT-184 and Centrosema molle, cultivated on topsoil. Fifteen days after the treatment fresh mass, dry mass, root/shoot ratio and biomass distribution were determined, as well as the concentration of soluble phenols, cell wall-bound phenols and total phenols, in addition to chlorophyll a, b and total chlorophyll. In both cultivars the roots were the most affected organs regarding fresh mass and there was a decrease of dry mass at high concentrations of NaCl. The root/shoot ratio showed an increase at 200 mM of NaCl in S. guianensis, while no significant changes were observed in C. molle. As the concentration of NaCl increased, the concentration of soluble phenols increased noticeably in the roots of both species, as well as total phenols; while in the leaves increases in the levels of soluble phenols were observed only in S. gui
Antiretroviral drug resistance in HIV-1 therapy-na ve patients in Cuba, 2006–2011
L Pérez,Y Alemán,C Correa,C Fonseca
Journal of the International AIDS Society , 2012, DOI: 10.7448/ias.15.6.18185
Abstract: In 2009, genotypic drug resistance testing was introduced for HIV-1 patients failing antiviral therapy in Cuba. The high prevalence of drug resistance in this population indicated the need for surveillance of transmitted drug resistance (TDR) in therapy-na ve patients. Therefore, the objectives of this study were to analyze the level and patterns of TDR and subtype in therapy-na ve HIV-1 patients in Cuba from 2006 to 2011, and to compare it with reported data from 2004 that indicated 4% TDR, solely restricted to NRTI. 153 plasma from HIV-1 therapy-na ve patients were collected between June 2006 and December 2011 and subsequently extracted, amplified and sequenced. Drug resistance was interpreted according to HIVdb v.6.1.1 and WHO list for TDR surveillance (2009) using the CPR tool v.6.0. Phylogenetic analysis was performed using Neighbour Joining (Kimura 2) in Mega 4. The majority of patients was male (82.4%), MSM (68.6%) and originated from Havana province (68.1%). 8.4% were recent infections. Subtype B was the most prevalent subtype (31.3%) followed by CRF20-23-24_BG (28.1%), CRF19 (18.3%) and CRF18 (13.0%). The prevalence of subtype B declined from 43.7% in the 2004 study to 31.3% in the present study, whereas BG recombinants increased from 14.4% to 28.1%. Overall, 12.4% (19/154) had evidence of TDR. 3.9% carried at least one NRTI, 1.9% at least one NNRTI and 1.9% at least one PI mutation. Drug resistance mutations against both NRTI and NNRTI were observed in 3.9%, whereas triple class resistance was found in only 0.6%. The most frequent NRTI mutations were M184V (55.5%), T215F/Y/rev (16.6%) and K70R (16.6%). The most frequent NNRTI mutations were K103N (61.1%) and G190A (22.2%). The most common PI mutation was L90M (5.5%). From the 19 patients with TDR, 13 (68.4%) were diagnosed with a recent HIV-1 infection. AZT/D4T + 3TC + NVP may be effective in 6 of the patients with TDR (31.5%), partially effective in 6 (31.5%) and ineffective in 7 (36.8%). AZT/D4T + 3TC + IDV would be effective in 9 of the patients with TDR (47.3%), partially effective in 8 (42.1%) and ineffective in 2 (10.5%). This analysis confirmed the further expansion of BG recombinants in Cuba and revealed that antiretroviral drug resistance in HIV-1 therapy-na ve patients has increased to 12.4% in 2006–2011. The current study emphasizes the need to perform surveillance studies for TDR in therapy-na ve patients, as the extent of TDR might jeopardize the effectiveness of first-line regimens prescribed in Cuba.
Family Control and Earnings Quality
Carolina Bona Sánchez,Jerónimo Pérez Alemán,Domingo Javier Santana Martín
Revista de Contabilidad : Spanish Accounting Review , 2007,
Abstract: El trabajo analiza la relación entre el control familiar y la calidad de la información contable en un contexto en el que el tradicional conflicto de agencia entre directivos y accionistas se desplaza a la divergencia de intereses entre accionistas controladores y minoritarios. Los resultados alcanzados muestran que, en comparación con las no familiares, las empresas de naturaleza familiar divulgan unos resultados de mayor calidad, tanto en términos de menores ajustes por devengo discrecionales como de mayor capacidad de los componentes actuales del resultado para predecir los cash flows futuros. Además, el aumento en los derechos de voto en manos de la familia controladora incrementa la calidad de los resultados contables. La evidencia obtenida se muestra consistente con la presencia de un efecto reputación/vinculación a largo plazo asociado a la empresa familiar. Adicionalmente, el trabajo refleja que a medida que disminuye la divergencia entre los derechos de voto y de cash flow en manos de la familia controladora, aumenta la calidad de la información contable.PALABRAS CLAVE: derechos de voto, divergencia, empresa familiar, calidad delresultado, reputación, beneficios privados.This work examines the relationship between family control and earnings quality in a context where the salient agency problem shifts away from the classical divergence between managers and shareholders to conflicts between the controlling owner and minority shareholders. The results reveal that, compared to non-family firms, family firms reveal higher earnings quality in terms of both lower discretionary accruals and greater predictability of future cash flows. They also show a positive relationship between the level of voting rights held by the controlling family and earnings quality. The evidence is consistent with the presence of a reputation/long-term involvement effect associated with the family firm. Moreover, the work reflects that, as the divergence between the voting and cash flow rights in the hands of the controlling family decreases, earnings quality increases.
Informativeness of accounting earnings in family firms
CAROLINA BONA SáNCHEZ,JERóNIMO PéREZ ALEMáN,DOMINGO JAVIER SANTANA MARTíN
Cuadernos de Gestión , 2009,
Abstract: This work examines the relationship between the family control and informativeness of accounting earnings in listed non-financial Spanish companies between 1997 and 2003. The results reveal a negative relationship between the family nature of the controlling shareholder and the credibility of accounting information. Moreover, as the level of voting rights in the hands of the family ultimate owner increases, the informativeness of earnings decreases. Only in family firms where the CEO is hired, the family nature affects positively on the informativeness of accounting earnings.
Caracterización morfológica de 13 variedades de arroz venezolanas
Montoya,María; Rodríguez,Nohelia; Pérez-Almeida,Iris; Cova,Jenny; Alemán,Luis;
Agronomía Tropical , 2007,
Abstract: in venezuela, rice, oryza sativa l., is the third cereal of human consumption, to which continuous studies are performed in search of genetic improvement. nowadays there are few references involving morphological characterization of the main varieties used in venezuelan rice production under the same experimental conditions. in this respect, we described 13 rice varieties available in our country and 35 elite lines jointly planted under alfa latticce (6*8) design with two blocks at inia-portuguesa experimental field, in order to evaluate 41 characters using the descriptors suggested by the international union for the protection of new varieties of plants (upov) and the international center for tropical agriculture (ciat) during all crop developmental stages, including culinary and milling quality, and disease incidence. under this study we found no significant differences among varieties yield, only 38.46% of the studied varieties presented less than 17% chalky plus white belly grains. concerning the yield of whole grain 61.54% of the materials had less than 47% and more than 96% showed intermediate values for amylose content. sarocladium oryzae and helminthosporium spp affected higher number of materials with an incidence between 5 and 25%. broadly speaking, through the morphological assessment we determined that qualitative nominal variables are the same for all the materials, whereas qualitative ordinal and quantitative variables differ, thus allowing to achieving a differential description among genetic materials.
Localización y afectación de costes medioambientales y no medioambientales en las empresas de aguas: el coste del agua desalada
Pérez Alemán,Jerónimo; Piedra Herrera,Francisca; Mesa Mendoza,Margarita; Bona Sánchez,Carolina;
Innovar , 2005,
Abstract: the directive 2000/60/ec of the european parliament and the council establishes a framework for community action in the field of water policy. this standard indicates in its article 9 that member of the states shall take account of the principle of recovery of the costs of water services, including the environmental ones. according to this legal framework, municipal water supply entities must generate information about their general costs and, more particularly, about their environmental costs and other environmental items. so, in this paper we focus on the cost of desalinated water, which is one of these entities? main outputs.
Necesidad de tratamiento ortodóncico en escolares. Aplicación del índice DAI
Alemán Estévez,María Gudelia; Martínez Brito,Isabel; Pérez Lauzurique,Aleida;
Revista M??dica Electr?3nica , 2011,
Abstract: the dental malocclusions are occlusal alterations or disorders that are subject of important aesthetic, ethnic and cultural conditionings, making it difficult its definition and classification. an early diagnosis and a successful treatment of the malocclusions may have benefits in a short term. this research was made in a sample of 450 students aged 8 and 9 years, 232 in the 8-years-old group, for the 51,6 %, and 218 in the 9-years-old group, representing the 48,4 %. with the purpose of determining the orthodontic treatment necessity, we carried out a cross-sectional, descriptive study, applying the dental esthetic index of the orthodontic treatment necessity, and determining that 32,9 % of the students had a slight malocclusion or normal occlusion, 24, 4 % a defined malocclusion, 16,0 % a serious malocclusion and 26,7 % a very serious malocclusion. we determined the high prevalence of treatment necessity in the studied ages.
índice de estética dental y criterio profesional para determinar la necesidad de tratamiento ortodóntico
Alemán Estévez,María Gudelia; Martínez Brito,Isabel; Pérez Lauzurique,Aleida;
Revista M??dica Electr?3nica , 2011,
Abstract: the dental malocclusion used to be the final product of several events in the human being growing up and development leaving prints in the oral-facial deformity; it is an entity increasing its prevalence and incidence, becoming a health problem. the purpose of this work was determining the necessity of the orthodontic treatment applying the dental aesthetic index, and comparing it with the criteria of the professional. the sample of the study was formed by 450 students aged 8-9 years from the heath area milanés, matanzas. we carried out a cross-sectional, descriptive study, determining the necessity of the orthodontic study altogether with the criteria of the professional, stating that 37,1 % of the patients who need treatment might be attended by the general integral stomatologist who may take preventive and interceptive measures, avoiding the malocclusions worsening. the biggest discrepancy found between the index and the criteria of the professional was in the category slight malocclusion where the specialist concluded that 48,6 % of the patients do not need treatment and the index established 32,9 %.
Flebotomíneos (Diptera: Psychodidae) antropofílicos de importancia en salud pública en Los Montes de María, Colombia
Cortés Alemán,Luis; Pérez-Doria,Alveiro; Bejarano Martínez,Eduar Elías;
Revista Cubana de Medicina Tropical , 2009,
Abstract: introduction: cutaneous leishmaniasis is an endemic disease in los montes de maría, colombia, but the identity of the human-biting sand fly species in the region remained unknown until now. objective: to determine the lutzomyia species that could be involved in the epidemiological cycle of cutaneous leishmaniasis in this area, considering their anthropophilic habits and epidemiological background. methods: sand flies were sampled using protected human baits, during the dry season in january and august, 2005, and the rainy period in april and november, 2005. human bait collections were made from 18:00 to 24:00 hours by three men equipped with mouth aspirators and torches, inside a house where a cutaneous leishmaniasis case had occurred the last year. results:a total of 567 sand flies of the genus lutzomyia were collected, comprising 504 females and 63 males. the composition of anthropophilic sand fly fauna was 97.5 % of lu. evansi, 1.23 % of lu. cayennensis cayennensis, 0.5 % of lu. panamensis, 0.5 % of lu. dubitans, and 0.2 % of lu. gomezi. the l. evansi female's biting rate on humans was 1.5 in january, 1.4 in april, 0.85 in august, and 0.6 in november. other lutzomyia species exhibited human-biting rates equal to 0 in january and april; and equal to or lower than 0,024 in august and november. conclusions: some of these sand fly species might play a role in the epidemiological cycle of cutaneous leishmaniasis in the region.
Flebotomíneos (Diptera: Psychodidae) antropofílicos de importancia en salud pública en Los Montes de María, Colombia Anthropophilic sand flies (Diptera: Psychodidae) of public health importance in Los Montes de María, Colombia
Luis Cortés Alemán,Alveiro Pérez-Doria,Eduar Elías Bejarano Martínez
Revista Cubana de Medicina Tropical , 2009,
Abstract: INTRODUCCIóN: la leishmaniasis cutánea es una enfermedad endémica en Los Montes de María, Colombia, pero hasta la fecha se desconocían los flebotomíneos que pican al humano en el área. OBJETIVO: determinar las especies de Lutzomyia que, por sus hábitos antropofílicos y antecedentes vectoriales, podrían mantener el ciclo epidemiológico de la leishmaniasis cutánea en la región. MéTODOS: se recolectaron los insectos con cebo humano protegido durante enero y agosto de 2005, que comprende parte de la época seca, así como en abril y noviembre del mismo a o, pertenecientes a la temporada de lluvias. Tres personas equipadas con aspiradores bucales y linternas se ubicaron entre las 18:00 y 24:00 h dentro de una vivienda, donde se había registrado un caso de leishmaniasis cutánea. RESULTADOS: se obtuvieron 567 flebotomíneos del género Lutzomyia, distribuidos en 504 hembras y 63 machos. La constitución de la fauna de flebotomíneos antropofílicos correspondió a 97,5 % Lutzomyia evansi, 1,23 % Lutzomyia cayennensis cayennensis, 0,5 % Lutzomyia panamensis, 0,5 % Lutzomyia dubitans y 0,2 % Lutzomyia gomezi. La tasa de picadura de las hembras de Lutzomyia evansi fue de 1,5 en enero, 1,4 en abril, 0,85 en agosto y 0,6 en noviembre. En las demás especies la tasa de picadura mostró valores de 0 en enero y abril, e iguales o inferiores a 0,024 en agosto y noviembre. CONCLUSIONES: algunas de las especies de flebotomíneos encontradas podrían participar en el ciclo epidemiológico de la leishmaniasis cutánea en la región. INTRODUCTION: cutaneous leishmaniasis is an endemic disease in Los Montes de María, Colombia, but the identity of the human-biting sand fly species in the region remained unknown until now. OBJECTIVE: to determine the Lutzomyia species that could be involved in the epidemiological cycle of cutaneous leishmaniasis in this area, considering their anthropophilic habits and epidemiological background. METHODS: sand flies were sampled using protected human baits, during the dry season in January and August, 2005, and the rainy period in April and November, 2005. Human bait collections were made from 18:00 to 24:00 hours by three men equipped with mouth aspirators and torches, inside a house where a cutaneous leishmaniasis case had occurred the last year. RESULTS: a total of 567 sand flies of the genus Lutzomyia were collected, comprising 504 females and 63 males. The composition of anthropophilic sand fly fauna was 97.5 % of Lu. evansi, 1.23 % of Lu. cayennensis cayennensis, 0.5 % of Lu. panamensis, 0.5 % of Lu. dubitans, and 0.2 % of Lu. gomezi. The L. evansi fem
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