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Search Results: 1 - 10 of 1208 matches for " Feria-Arroyo "
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Reevaluación del riesgo de extinción de cinco especies del género Polianthes L. (Agavaceae)
Feria-Arroyo, Teresa Patricia;Solano, Eloy;García-Mendoza, Abisaí;
Acta botánica mexicana , 2010,
Abstract: we reassessed the extinction risk of the species polianthes densiflora, p. howardii, p. longiflora, p. palustris and p. platyphylla by applying the mer (method of evaluation of extinction risk of wild species for mexico). these species are listed as rare by the international union for conservation of nature (iucn) and are considered to be in the category of special protection according to mexican regulation. mer criterion a (geographic distribution) was assessed with three methods: area of occupancy, extent of ocurrence, and species distribution models. criteria b (habitat conditions) and d (impact of human activity) were examined by superimposing the human footprint map of sanderson et al., where values range from 0 to 100. in this map, 0-10 denote pristine areas and 100 indicates that the habitat has been completely transformed. criterion c (intrinsic biological vulnerability) was assigned based on the geophytic nature of the species. according to our findings, polianthes densiflora and p. longiflora are in danger of extinction, while p. howardii and p. platyphylla are endangered and p. palustris is likely extinct. none of the five species concerned occur in any natural protected area. we propose in situ and ex situ strategies to maintain these species as well as the development of programs of sustainable use for polianthes longiflora and p. platyphylla. these species could be cultivated and domesticated by means of vegetative propagation.
REEVALUACIóN DEL RIESGO DE EXTINCIóN DE CINCO ESPECIES DEL GéNERO POLIANTHES L. (AGAVACEAE)
Teresa Patricia Feria-Arroyo,Eloy Solano,Abisaí García-Mendoza
Acta botánica mexicana , 2010,
Abstract: Con base en el método de evaluación del riesgo de extinción de las especies silvestres en México (MER), se redefinió el de Polianthes densiflora, P. howardii, P. longiflora, P. palustris y P. platyphylla. Estas cinco plantas se encuentran listadas en la categoría de protección especial en la Norma Oficial Mexicana y fueron catalogadas como raras por la Unión Internacional para la Conservación de la Naturaleza (IUCN). El criterio A del MER (amplitud de la distribución geográfica) se estimó mediante tres métodos: área ocupada, extensión del área ocupada y mapas obtenidos a partir de modelos de distribución. Los criterios B (condición del hábitat natural) y D (impacto humano) fueron evaluados con base en el mapa de Influencia Humana de Sanderson et al., el cual asigna valores entre 0 y 100, en donde 0-10 indica áreas conservadas y 100 la total destrucción del hábitat. El criterio C (vulnerabilidad intrínseca), se asignó en función de la naturaleza geófila de las especies. Los resultados obtenidos sugieren que Polianthes densiflora y P. howardii están en peligro de extinción, P. longiflora y P. platyphylla se encuentran amenazadas y P. palustris está probablemente extinta. Ninguna de las cinco plantas se ha registrado en alguna área Natural Protegida. Se proponen estrategias de conservación in situ y ex situ para las especies estudiadas, así como el desarrollo de programas de uso sustentable para P. longiflora y P. platyphylla, que podrían ser cultivadas y domesticadas mediante la propagación vegetativa.
Metástasis poco frecuentes del carcinoma renal
Arroyo, Carlos;Palacios, Pedro;Uribe, Norma;Barrera, Manuel;Feria, Guillermo;
Gaceta médica de México , 2005,
Abstract: introduction: renal clear cell carcinoma (rccca) represents 2-3% of the neoplasms in the adult population, and can be metastatic in up to 30% at the time of diagnosis. in these cases its mortality can be of up to 99% in 5 years, due to the lack of response to current treatments, unless it is a single, surgically resectable metastasis. currently, there is no explanation for its routes of progression, it even seems to be non existent based on the rare tumor implant sites. objective: to report unusual metastasis from rccca and a review of the literature. material and methods: we reviewed retrospectively 15 years of patient records diagnosed with metastatic carcc different from: local lymph nodes, lung, bone or liver. we identified 11 cases: brain (2), duodenum (2), tonsils, thyroid, esophagus, diaphragm, testicle, adrenal gland and soft tissue of the knee. conclusion: a description of this and other literature series with rare metastasis was done, as well as an analysis of possible routes and mechanisms responsible for the unusual tumor progression in rccca. we need to continue investigating the dissemination pathways and other cellular conditions involved in metastatic kidney cancer in order to better understand and improve the treatment of patients in advanced stages.
Projected Future Distributions of Vectors of Trypanosoma cruzi in North America under Climate Change Scenarios
Miroslava Garza,Teresa Patricia Feria Arroyo ,Edgar A. Casillas,Victor Sanchez-Cordero,Chissa-Louise Rivaldi,Sahotra Sarkar
PLOS Neglected Tropical Diseases , 2014, DOI: 10.1371/journal.pntd.0002818
Abstract: Background Chagas disease kills approximately 45 thousand people annually and affects 10 million people in Latin America and the southern United States. The parasite that causes the disease, Trypanosoma cruzi, can be transmitted by insects of the family Reduviidae, subfamily Triatominae. Any study that attempts to evaluate risk for Chagas disease must focus on the ecology and biogeography of these vectors. Expected distributional shifts of vector species due to climate change are likely to alter spatial patterns of risk of Chagas disease, presumably through northward expansion of high risk areas in North America. Methodology/Principal Findings We forecast the future (2050) distributions in North America of Triatoma gerstaeckeri and T. sanguisuga, two of the most common triatomine species and important vectors of Trypanosoma cruzi in the southern United States. Our aim was to analyze how climate change might affect the future shift of Chagas disease in North America using a maximum entropy algorithm to predict changes in suitable habitat based on vector occurrence points and predictive environmental variables. Projections based on three different general circulation models (CCCMA, CSIRO, and HADCM3) and two IPCC scenarios (A2 and B2) were analyzed. Twenty models were developed for each case and evaluated via cross-validation. The final model averages result from all twenty of these models. All models had AUC >0.90, which indicates that the models are robust. Our results predict a potential northern shift in the distribution of T. gerstaeckeri and a northern and southern distributional shift of T. sanguisuga from its current range due to climate change. Conclusions/Significance The results of this study provide baseline information for monitoring the northward shift of potential risk from Chagas disease in the face of climate change.
Climate-Induced Range Shifts and Possible Hybridisation Consequences in Insects
Rosa Ana Sánchez-Guillén, Jesús Mu?oz, Gerardo Rodríguez-Tapia, T. Patricia Feria Arroyo, Alex Córdoba-Aguilar
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0080531
Abstract: Many ectotherms have altered their geographic ranges in response to rising global temperatures. Current range shifts will likely increase the sympatry and hybridisation between recently diverged species. Here we predict future sympatric distributions and risk of hybridisation in seven Mediterranean ischnurid damselfly species (I. elegans, I. fountaineae, I. genei, I. graellsii, I. pumilio, I. saharensis and I. senegalensis). We used a maximum entropy modelling technique to predict future potential distribution under four different Global Circulation Models and a realistic emissions scenario of climate change. We carried out a comprehensive data compilation of reproductive isolation (habitat, temporal, sexual, mechanical and gametic) between the seven studied species. Combining the potential distribution and data of reproductive isolation at different instances (habitat, temporal, sexual, mechanical and gametic), we infer the risk of hybridisation in these insects. Our findings showed that all but I. graellsii will decrease in distributional extent and all species except I. senegalensis are predicted to have northern range shifts. Models of potential distribution predicted an increase of the likely overlapping ranges for 12 species combinations, out of a total of 42 combinations, 10 of which currently overlap. Moreover, the lack of complete reproductive isolation and the patterns of hybridisation detected between closely related ischnurids, could lead to local extinctions of native species if the hybrids or the introgressed colonising species become more successful.
El SRI de Aguascalientes a través de sus códigos lingüísticos en la prensa diaria: una aproximación
Feria Cruz, Maribel;
Contaduría y administración , 2008,
Abstract: starting from the analysis of content of the communication codes used among the actors of the national systems of innovation (nsi) -with particular attention to the regional system of innovation of aguascalientes (rsi)-, such that they were extracted of a journalistic corpus conformed by diverse written means, this work seeks to know some of the nexuses that link to the companies and institutions of aguascalientes with the economic development at level speech, as well as the difficulties for the integration of nets of innovation.
Patrimonio territorial y desarrollo sostenible: un estudio comparativo en Iberoamérica y Espa a
Feria Toribio, José Ma
Estudios Geográficos , 2010,
Abstract: This paper intends to explore, through the comparative analysis o five study cases in Latin America and Spain, the relationships between territorial heritage and sustanaible development. In order to cope wth this aim, first, it should deep on the conceptual and methodological basis linked to both terms and, secondly, from then, to develop an empirical task which allow to recognize and to evaluate, on commom basis, the main characteristics of the territoriall heritage in each study area and their relationships with sustainable development. The analysis provides ambivalent conclusions, since together the evident richness of territorial heritage in all the study areas and their better relative socioeconomic development situation, it is found out an uneven explotaition of territorial resources and scarce attention to environmental sustainability. El artículo plantea explorar, a través del análisis comparativo de cinco ámbitos de estudio en Iberoamerica y Espa a, las relaciones entre patrimonio territorial y desarrollo sostenible. Para cubrir dicho objetivo, es necesario profundizar en las bases conceptuales y metodológicas que implican ambas nociones y, a partir de ellas, realizar un trabajo de sistematización empírica que permita reconocer y evaluar, sobre patrones comunes, las características del patrimonio territorial y su relación con el desarrollo sostenible en cada uno de los ámbitos. Las conclusiones derivadas del análisis son ambivalentes, ya que a la demostrada riqueza del patrimonio territorial en todos los ámbitos analizados y a su mejor situación relativa en cuanto a desarrollo socioeconómico, se une una desequilibrada explotación de los recursos territoriales y una escasa atención a las cuestiones de sostenibilidad ambiental. [fr] Cet article propose d’analyser, à travers de l’analyse comparative de cinq domaines d’étude en L’Amérique Latine et en L’Espagne, les relations entre le patrimoine territoriel et le développement durable. Pour atteindre cet objectif, il est nécessaire d’approfondir dans les bases conceptuelles et méthodologiques qui impliquent les deux concepts et, à partir d’elles, effectuer un travail de systématisation empirique qu’il permet de reconna tre et d’évaluer, sur les patrons communs, les caractéristiques du patrimoine territoriel et sa relation avec le développement durable dans chacun des domaines. Les conclusions dérivées de l’analyse sont ambivalents, puisqu’à la richesse démontrée du patrimoine territoriel dans tous les domaines analysés et à sa meilleure situation relative quant à développement socio-économique, on
El SRI de Aguascalientes a través de sus códigos lingüísticos en la prensa diaria. Una aproximación
Maribel Feria Cruz
Contaduría y administración , 2008,
Abstract: A partir del análisis de contenido de los códigos de comunicación empleados entre los actores de los Sistemas Nacionales de Innovación (SNI) -con particular atención al Sistema Regional de Innovación de Aguascalientes (SRI)- y que fueron extraídos de un corpus periodístico conformado por diversos medios escritos, este trabajo pretende conocer algunos de los nexos que a nivel discurso vinculan a las empresas e instituciones aguascalentenses con el desarrollo económico, así como las dificultades para la integración de redes interinstitucionales de innovación.
The general $ Gamma -$ compatible rook length polynomials
Edward Arroyo,Fangjun Arroyo
Tamkang Journal of Mathematics , 2010, DOI: 10.5556/j.tkjm.41.2010.195-206
Abstract: Rook placements and rook polynomials have been studied by mathematicians since the early 1970's. Since then many relationships between rook placements and other subjects have been discovered (cf. [1], [6-15]). In [2] and [3], K. Ding introduced the rook length polynomials and the $ gamma - $compatible rook length polynomials. In [3] and [4], he used these polynomials to establish a connection between rook placements and algebraic geometry for the first time. In this paper, we give explicit formulas for the $ gamma - $compatible rook length polynomials in more general cases than considered in [3]. In particular, we generalize the formula for the rook length polynomial in the parabolic case in [2] to the $ gamma -$compatible rook length polynomial.
La cooperación en los procesos de transferencia de conocimiento científico-tecnológico en México: Una evidencia empírica
Feria,Víctor; Hidalgo,Antonio;
Innovar , 2012,
Abstract: the relationship between science and the productive sector in knowledge transference (kt) processes has become less fortuitous and more systemic. however, although there are many ways to carry out kt between companies and universities, there is still very little understanding of these mechanisms. this publication presents the results of an analysis focusing on scientific-technological knowledge transference at four mexican companies, and carried out using a case study approach. the analysis stresses the use of kt mechanisms by companies as a way to obtain scientific- technological knowledge, build scientific-technological capacities and in terms of the scope of the results of our r & d and innovation.
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