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Search Results: 1 - 10 of 5047 matches for " Doroteo Reyes "
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Nucleocytoplasmic Gynodioecy  [PDF]
R. Doroteo, J. A. Vargas
Applied Mathematics (AM) , 2013, DOI: 10.4236/am.2013.412226

We study the evolution of a gynodioecious species under mixed-mating through a nucleocytoplasmic male sterility model. We consider two cytoplasmic types and a nuclear locus with two alleles. Here, the interaction between one cytoplasmic type and a recessive nuclear male-sterility factor gives rise to only one female genotype, while the remaining types correspond to hermaphroditic plants. We include two fitness paramaters: the advantageous female fitness t of females relative to that of hermaphrodites; and a silent and dominant cost of restoration, that is, a diminished fitness for plants carrying a dominant restorer gene relative to that of hermaphrodites. The parameter related to the cost of restoration is assumed to be present on outcrossing male fertility only. We find that every population converges to a stable population. We also determine the nature of the attracting stable population, which could be a nucleocytoplasmic polymorphism, a nuclear polymorphism or another population with some genotypes absent. This depends on the position of t with respect to critical values expressed in terms of the other parameters and also on the initial population.

Avifauna de la Reserva de la Biosfera Barranca de Metztitlán, Hidalgo, México Birds of the Biosphere Reserve Barranca de Metztitlán, Hidalgo, Mexico
Raúl Ortiz-Pulido,Jessica Bravo-Cadena,Vanessa Martínez-García,Doroteo Reyes
Revista mexicana de biodiversidad , 2010,
Abstract: El manejo y conservación de un área natural protegida depende en gran parte del conocimiento biológico que se tenga sobre ella. En este estudio se presenta el listado de las aves de la Reserva de la Biosfera Barranca de Metztitlán, Hidalgo, México realizado durante 7 a os de trabajo de campo y que incluye 271 especies. Las familias más ricas fueron Tyrannidae y Parulidae (24 especies cada una), Emberizidae (19), Icteridae (13) y Trochilidae (12). Se registran 117 especies como residentes, 88 migratorias, 34 ocasionales, 6 con poblaciones residentes-migratorias y 26 sin estacionalidad clara. Se observaron 16 especies abundantes, 67 comunes, 153 raras y 35 sin abundancia relativa clara. Los tipos de vegetación más utilizados por las aves son: matorral submontano (113 especies), bosque tropical caducifolio (97), bosque de tascate (96) y matorral crasicaule con dominancia de S. dumortieri (91). Los gremios alimenticios mejor representados fueron: insectívoro (235 especies), frugívoro (88) y granívoro (85). Con base en la normatividad mexicana, se registraron 17 especies bajo alguna categoría de riesgo y 32 con algún grado de endemismo. En la zona habitan cerca del 60% de las aves de Hidalgo y 27% de las de México, razón por la cual se sugiere que esta zona sea declarada área Importante para la Conservación de las Aves (AICA) en México. Management and conservation of natural protected areas depends critically on their biological knowledge. Herein we report a check-list of the Barranca de Metztitlán Biosphere Reserve, Hidalgo, Mexico. We registered 271 species. The families that include more species were Tyrannidae and Parulidae (24 species each one), Emberizidae (19), Icteridae (13) and Trochilidae (12). We recorded 117 resident species, 88 migratory, 34 transient, 6 with resident-migratory populations and 26 with status not clear. We registered 16 abundant species, 67 common, 153 rare, and 35 with undetermined abundance. The richest vegetation types were: submontane shrubland with 113 species, tropical deciduous forest with 97, Juniperus forest with 96, and crasicaule shrubland with Stenocereus dumortieri dominance with 91. The best represented gremials were: insectivorous (235 species), frugivorous (88), and granivorous (85). We found 17 species under some risk category according with the Mexican law, and 32 species possesses some endemic degree. In the reserve inhabit near of the 60% of the birds of the Hidalgo state and 27% of the Mexican birds. This region should be considered as an Important Bird Area in Mexico.
Multilayer Graphene Synthesized by CVD Using Liquid Hexane as the Carbon Precursor  [PDF]
Claudia Bautista Flores, Doroteo Mendoza López
World Journal of Condensed Matter Physics (WJCMP) , 2011, DOI: 10.4236/wjcmp.2011.14023
Abstract: We produce multilayer graphene by the Chemical Vapor Deposition (CVD) method at atmospheric pressure and 1000°C, using flexible copper substrates as catalyst and liquid hexane as the source of carbon. We designed an optical device to measure the transmittance of the carbon films; with this information we calculate that the approximate number of layers is 11.
Factores Comunes en la Información Financiera de las Empresas y su Relación con el Tama o
Doroteo Martín Jiménez
Revista de Contabilidad : Spanish Accounting Review , 1999,
Abstract: El presente trabajo tiene como objetivo analizar los factores que explican la variabilidad de la información contable recogida en las cuentas anuales de las empresas. Para ello se parte de una muestra de sociedades industriales de Castilla y León en los Registro Mercantiles en los a os 1992 y 1994. Se utilizan treinta y siete ratios como variables de partida y se obtiene un conjunto de factores, entre 7 y 12, que consiguen explicar la variabilidad de la información de los datos de panida. Asimismo se estudian posibles diferencias en los resultados cuando se agrupan las empresas en función de su tama o. The object of this paper is to analyse the Factors explaining the variability of the accounting information contained in the annual accounts of an enterprise. The sample consists of the annual accounts prepared by industrial enterprises in 1992 and 1994. Thirty seven ratios were used as initial variables and between 7 and 12 factors were found to explain the variability of the initial information for each one of cases tested. Differences in the results are studied and commented upon when the enterprises are grouped according to their size.
Avifauna de la Reserva de la Biosfera Barranca de Metztitlán, Hidalgo, México
Ortiz-Pulido, Raúl;Bravo-Cadena, Jessica;Martínez-García, Vanessa;Reyes, Doroteo;Mendiola-González, Ma. Eugenia;Sánchez, Guillermo;Sánchez, Maximino;
Revista mexicana de biodiversidad , 2010,
Abstract: management and conservation of natural protected areas depends critically on their biological knowledge. herein we report a check-list of the barranca de metztitlán biosphere reserve, hidalgo, mexico. we registered 271 species. the families that include more species were tyrannidae and parulidae (24 species each one), emberizidae (19), icteridae (13) and trochilidae (12). we recorded 117 resident species, 88 migratory, 34 transient, 6 with resident-migratory populations and 26 with status not clear. we registered 16 abundant species, 67 common, 153 rare, and 35 with undetermined abundance. the richest vegetation types were: submontane shrubland with 113 species, tropical deciduous forest with 97, juniperus forest with 96, and crasicaule shrubland with stenocereus dumortieri dominance with 91. the best represented gremials were: insectivorous (235 species), frugivorous (88), and granivorous (85). we found 17 species under some risk category according with the mexican law, and 32 species possesses some endemic degree. in the reserve inhabit near of the 60% of the birds of the hidalgo state and 27% of the mexican birds. this region should be considered as an important bird area in mexico.
Diagnóstico y tratamiento de la uretritis crónica en la sanidad militar con el cambio de siglo (XIX-XX)
Martín-Laborda y Bergasa,Fernando; Lozano Lozano,Doroteo;
Archivos Espa?oles de Urología (Ed. impresa) , 2007, DOI: 10.4321/S0004-06142007000800018
Abstract: objectives: we can say that in military hospitals, pioneer institutions in health-care in our country, approximately 25% of the pathology over the second half of the 19th century would correspond to sexually transmitted diseases (std,) with hospital wards dedicated to these diseases , initially associated with genitourinary diseases. the "military drip" or blennorrhagic urethritis was a venereal disease with great incidence and prevalence in the pre-antibiotic era. this article reviews the diagnostic and therapeutic methods employed by spanish military doctors during such period. methods: in the introduction we state the relationship between the knowledge of the time and the environment in which military doctors developed their professional activity. we make reference to military health-care journals, vehicle for their worries and demonstration of the level of theoretical and practical knowledge they were distinguished for. based on their service records and publications we refer the urologists from the military health-care system that showed a greater interest in the field of urethral diseases, talking about the methodology they used for diagnosis and treatment of blennorrhagic urethritis. results and conclusions: military health-care at the end of 18th century and the beginning of the 19th century joined a group of professionals who demonstrated talent and perseverance in the treatment of "military drip". to know the concepts for the diagnosis and treatment of urethritis improves our perspective in the knowledge of these pathologies, and confirms us in the evaluation of the advances available for us today, thanks to the addition of efforts of our predecessors.
Implementation of an efficacious intervention for high risk women in Mexico: protocol for a multi-site randomized trial with a parallel study of organizational factors
Patterson Thomas L,Semple Shirley J,Chavarin Claudia V,Mendoza Doroteo V
Implementation Science , 2012, DOI: 10.1186/1748-5908-7-105
Abstract: Background Studies of implementation of efficacious human immunodeficiency virus (HIV) prevention interventions are rare, especially in resource-poor settings, but important, because they have the potential to increase the impact of interventions by improving uptake and sustainability. Few studies have focused on provider and organizational factors that may influence uptake and fidelity to core intervention components. Using a hybrid design, we will study the implementation of an efficacious intervention to reduce sexually transmitted infections (STIs) among female sex workers (FSWs) in 12 cities across Mexico. Our protocol will test a ‘train-the-trainer’ implementation model for transporting the Mujer Segura (Healthy Woman) intervention into community-based organizations (CBOs). Methods We have partnered with Mexican Foundation for Family Planning (Mexfam), a non-governmental organization that has CBOs throughout Mexico. At each CBO, trained ethnographers will survey CBO staff on characteristics of their organization and on their attitudes toward their CBO and toward the implementation of evidence-based interventions (EBIs). Then, after CBO staff recruit a sample of 80 eligible FSWs and deliver a standard-care, didactic intervention to 40 women randomly selected from that pool, a Mexfam staff person will be trained in the Mujer Segura intervention and will then train other counselors to deliver Mujer Segura to the 40 remaining participating FSWs. FSW participants will receive a baseline behavioral assessment and be tested for HIV and STIs (syphilis, gonorrhea, and chlamydia); they will be reassessed at six months post-intervention to measure for possible intervention effects. At the same time, both qualitative and quantitative data will be collected on the implementation process, including measures of counselors’ fidelity to the intervention model. After data collection at each CBO is complete, the relative efficacy of the Mujer Segura intervention will be analyzed, and across CBOs, correlations will be examined between individual and organizational provider characteristics and intervention efficacy. Discussion This cooperative, bi-national research study will provide critical insights into barriers and facilitating factors associated with implementing interventions in CBOs using the ‘train the trainer’ model. Our work builds on similar scale-up strategies that have been effective in the United States. This study has the potential to increase our knowledge of the generalizability of such strategies across health issues, national contexts, and
Improving the Reliability of Unmanned Aircraft System Wireless Communications through Cognitive Radio Technology  [PDF]
Hector Reyes, Naima Kaabouch
Communications and Network (CN) , 2013, DOI: 10.4236/cn.2013.53027

Unmanned Aircraft System networks are a special type of networks where high speeds of the nodes, long distances and radio spectrum scarcity pose a number of challenges. In these networks, the strength of the transmitted/received signals varies due to jamming, multipath propagation, and the changing distance among nodes. High speeds cause another problem, Doppler Effect, which produces a shifting of the central frequency of the signal at the receiver. In this paper we discuss a modular system based on cognitive to enhance the reliability of UAS networks.

?La voz del Amado1?: Palabras de promesa y realidad del entendimiento en el Com Cant de Gregorio de Nisa
Teología y vida , 2011, DOI: 10.4067/S0049-34492011000100008
Abstract: this article aims to understand the relationship between reason and revelation in in cant. by gregory of nyssa. the subject basically pertains to theological anthropology, since, faced with finite man's difficulty in aspiring to the infinite, the experience of grace becomes clear: without discrediting human effort or reason, the nyssian asserts that it is only known through love; god is recognized as always greater, and reason within its own limits.
La analogía como estrategia para desarrollar el pensamiento
EPISTEME , 2007,
Abstract: the necessity of motivating or stimulating the thinking capabilities of our students has been frequently emphasized; in fact, this has even been suggested in a variety of bibliographical sources. however, it is necessary to think over the importance that such thinking capabilities have, as well as the different alternatives that can be generated to promote them in students. in this respect, the analogical process is proposed as one of the many effective activities to achieve this goal.
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