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Search Results: 1 - 10 of 122558 matches for " José Luis;Sosa Ramírez "
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Ab Initio Molecular Orbital Calculation for Optical and Electronic Properties Evaluation of Small and Medium Size Silicon Nano-Clusters Found in Silicon Rich Oxide Films  [PDF]
Néstor David Espinosa Torres, José Francisco Javier Flores Gracia, José Alberto Luna López, Juan Carlos Ramírez García, Alfredo Morales Sánchez, José Luis Sosa Sánchez, David Hernández de la Luz, Francisco Morales Morales
Journal of Modern Physics (JMP) , 2013, DOI: 10.4236/jmp.2013.411A2001
Abstract:

In systems in atomic and nano scales such as clusters or agglomerates constituted of particles from a few to less than one hundred of atoms, quantum confinement effects are very important. Their optical and electronic properties are often dependent on the size of the systems and the way in which the atoms in these clusters are bonded. Generally, these nano-structures display optical and electronic properties significantly different of those found in corresponding bulk materials. Silicon agglomerates found in Silicon Rich Oxide (SRO) films have optical properties, which have reported as depended directly on nano-crystal size. Furthermore, the room temperature photoluminescence (PL) of Silicon Rich Oxides (SRO) has repeatedly generated a huge interest due to their possible applications in optoelectronic devices. However, a plausible emission mechanism has not yet widespread acceptance of the scientific community. In this research, we employed the Density Functional Theory with a functional B3LYP and a basis set 6 - 31G* to calculate the optical and electronic properties of small (six to ten silicon atoms) and medium size clusters of silicon (constituted of eleven to fourteen silicon atoms). With the theoretical calculation of the structural and optical properties of silicon clusters, it is possible to evaluate the contribution of silicon agglomerates in the luminescent emission mechanism experimentally found in thin SRO films.

Ordenamiento ecológico comunitario: un modelo de manejo de recursos naturales para el desarrollo comunitario. Estudio de caso ejido Potrero de los López, Aguascalientes
Meraz Jiménez, Antonio de Jesús;Galarza Mendoza, José Luis;Sosa Ramírez, Joaquín;Ponce Montoya, Amalio;Torres González, Jorge Alejandro;
Revista Chapingo. Serie ciencias forestales y del ambiente , 2011, DOI: 10.5154/r.rchscfa.2010.11.044
Abstract: natural resource management based on participatory community-based environmental management (pcem) is a support tool to implement rural development projects at the community level, from a regional planning framework through the use and application of technical tools to analyze the potentials and limits of natural resources and the use of a methodology to drive participatory processes. management elements and production processes were characterized and defined using landform, land use and vegetation through field samplings of 1000 m2 plots for forests and 1 m2 ones for pasturelands, validated by sub-supervised spot image classification and the edaphological conditions proposed by inegi (1978). through participatory planning workshops conducted in 2006, the results of the technical analysis were compared and validated and the community proposals were identified. among the strategic guidelines are: appropriate livestock, agricultural, forestry and ecotourism uses; conservation, reconstruction of water bodies; and restoration of degraded ecosystems, which is based on taking decisions such as establishing buffer zones between use areas and conservation areas where the original ecosystem remains.
Desarrollo ovárico y su relación con las concentraciones séricas de 17β-estradiol y 17α-hidroxi- 4-pregnen-3-ona en hembras de primera maduración de pez blanco, Chirostoma humboldtianum (Atheriniformes: Atherinopsidae)
Blancas Arroyo, Guillermo Artemio;Barriga Sosa, Irene de los ángeles;Morato Cartagena, Tomás;Romero Ramírez, Carlos Manuel;Arredondo Figueroa, José Luis;
Veterinaria México , 2008,
Abstract: the first reproductive cycle of 50 females of the shortfin silverside, chirostoma humboldtianum (valenciennes) in culture conditions was analyzed. ovarian developmental stages, gonadosomatic (gi) and hepatosomatic (hi) indexes were described. histo-logical description of the ovaries and quantification of estradiol serum levels (e2) and 17α-hydroxy-4-pregnen-3-one (17-p4) by radioinmune assay were performed. results showed a first reproductive season longer than six months. females initiated spawning at the age of one year. four ovarian maturation stages (i to iv) were determined during the spawning season and one (v) during the non-spawning season, the last one showed a non-defined pattern of development. the gi and hi indexes values indicate a positive lineal relation to body-weight only during the reproductive season (r2 = 0.74 and r2 = 0.86, p < 0.05, respectively). histological analysis of the ovaries indicated that the species correspond to the pattern described as group-synchronous with multiple spawnings. the follicular population showed reproductive activity during the first stages of maturation with a predominant population of pre-vitellogenic follicles. as the ovarian maturation increased, the presence of all the follicular developmental stages was observed, with a tendency of an increase of vitellogenic and mature follicles. the concentration of circulating sexual steroid hormones of estradiol (e2) and 17α-hydroxy-4-pregnen-3-one (17-p4) were high during stage i (2.5 ± 0.7 ng/m l and 2.4 ± 0.3 ng/mlfor e2 and 17-p4, respectively); a decrease was observed during stage ii, and the highest values were observed in stage iv (7.6 ± 2.1 ng/ml for e2 and 1.8 ± 0.9 ng/ml for 17-p4). the same pattern was observed during non-spawning season (anova p < 0.05), these results are the first findings on the reproductive physiology of the shortfin silverside fish, suggesting an early steroidogenic activity in immature females. furthermore, the species maintains its hormona
Mexican Guidelines for the Diagnosis and Treatment of Chronic Myeloid Leukaemia  [PDF]
Eduardo Cervera, Federico Godínez, Rosa Sosa, Ramón Rivas, Carlos Best, Juan Hernández, Adrián Morales, Hugo Zurita, Ivette Carrasco, Jorge Cruz, álvaro Aguayo, José Espinoza, Juan Labardini, Luis Valero, Judith Cruz, Diana Arcos, Diego Limón, Omar López-Navarro, Daniela Gordillo-Bastidas, Myrna Candelaria, Francisco Torres, Juan Kassack, Oscar de Jesús Pérez Ramírez, Jorge Aquino, Guillermo Díaz, Mariela Cardiel, Margarita Rodríguez, Patricia Montoya, Juan Contreras, María Chávez, Sandra Chávez, David Gómez, Olga Cantú, Jorge Duque, Luis Pita, Eduardo Lobato, Julio López, Antonio López, Pedro González, Jorge Cortés
Journal of Cancer Therapy (JCT) , 2013, DOI: 10.4236/jct.2013.43092
Abstract:

Background: This document includes recommendations and guidelines issued by a group of Mexican researchers and specialists gathered in the First National Colloquium for the Diagnosis and Management of Chronic Myeloid Leukaemia (CML) by initiative of Instituto Nacional de Cancerología and with the support of the Leukaemia Department of the MD Anderson Cancer Center. Mexico lacks of updated information taken from its own reality on the diagnosis and treatment of CML and other haematological disorders; besides, there are no national guidelines. Aim: To publish a consensus document with guidelines for the management of CML adjusted to the national environment and overall characteristics. Method: The participants answered a DELPHI questionnaire about the overall aspects of the disease, aiming to target controversial topics, discuss them in the colloquium, and to agree on the best ones. After those meetings, a final document was drawn up. Results: The group presents recommendations for definition, diagnosis, prognosis, monitoring, and treatment of CML in Mexico. Conclusions: Having consensus guidelines for the clinical management of CML in our country will enable the consensual practice of Mexican specialists regarding the clinical approach to CML, as well as optimize the resources which allow the rational planning of the medical care strategies.

Biosafety why and for whom? Latin America on target
Ramírez,José Luis;
Interciencia , 2003,
Abstract: latin american countries (lac), as never before face contrasting forces from economical, ecological and social sectors influencing their decision to embrace or not a modern biotechnology based agriculture. an unevenly scientifically educated general public, when challenged by economical and ecological lobbying groups, frequently overreacts, hampering clear sighted and knowledge based decision making. in this essay, several critical issues proper of lac are addressed. a survey of the situation in three countries is presented and several recommendations are advanced. finally the role of the united nations university programme biotechnology for latin america and the caribbean in empowering lac institutions to deal with the challenges of agri-biotechnology is highlighted.
Impacto de la biología molecular, genómica y proteómica en el estudio de los Kinetoplastida
Ramírez,José Luis;
Boletín de Malariología y Salud Ambiental , 2006,
Abstract: kinetoplastida is an order of protozoa that includes important pathogens to humans, animals and plants. here, a historical recounting of the impact of molecular biology on kinetoplastida biology is made. this review is mainly focused on the new developments originated after the publication of the genome sequences of leishmania major, trypanosoma cruzi, and trypanosoma brucei, emphasizing those subjects where useful information can be derived to fight these parasites. in addition, the new tendencies that may be relevant to parasitology in the near future are discussed, such as the application of systems biology to study the host-parasite interaction. systemic considerations are made to direct the attention to new metabolic or genetic hubs, de-emphasizing the attack of the complex parasite system of surface proteins or surfome this review is aimed to non-molecular biology specialists.
La Retórica, fundamento de la ciudadanía y de la formación escolar en la sociedad moderna - Rhetoric: the foundation for citizenship and academic education in modern society
José Luis Ramírez
Foro Interno : Anuario de Teoría Política , 2008,
Abstract: This article does not involve an attempt to analyze processes or structures, as is common in political science. Instead, we will seek to discover what, according to Aristotle, enables and composes the political life of the citizen. Aristotle presents politics as the result of an architecture of prudence and science; the instrument that generates that architecture is language. The use of this social instrument, fundamental for the establishment of human society and its political organization, is what we know as Rhetoric. An instrument is a manner of achieving specific forms and goals, but when the instrument acquires a fundamental nature, it no longer functions simply as a means of attaining goals, and actually takes on the role of determining the end and the structure that is being developed. This instrumentality that directs and orients us can also at times remain unnoticed, as part of the collective subconscious. Considering Rhetoric as the conscious use of language, the author seeks to emphasize the value of rhetorical consciousness, which is essential in the coordination of action for each and every member of a social and political community.
La libertad: un enga o conceptual?
José Luis Ramírez
Foro Interno : Anuario de Teoría Política , 2002,
Abstract:
El retorno de la retórica
José Luis Ramírez
Foro Interno : Anuario de Teoría Política , 2001,
Abstract:
International workshop: building (Bio) pharmaceutical systems in developing countries, United Nations University Institute for New Technologies (INTECH), Maastricht: 26-27 february 2003
Ramírez José Luis
Memórias do Instituto Oswaldo Cruz , 2003,
Abstract:
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