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Search Results: 1 - 10 of 8646 matches for " Felipe Nava Peralta "
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Evaluación de maíces precoces e intermedios en valles altos centrales de México. II. Divergencia genética
Felipe Nava Peralta,Josu00E9 Apolinar Meju00EDa Contreras
Revista fitotecnia mexicana , 2002,
Abstract: En algunas poblaciones de maíz (Zea mays L.) utilizadas en los programas de mejoramiento genético de Valles Altos Centrales de México se desconocen las razas y las relaciones de parentesco, por lo que se planteó este estudio para determinar el grado de asociación de las poblaciones de maíz y agruparlas mediante técnicas de taxonomía numérica. Se evaluaron 109 poblaciones de maíz y testigos en un dise o de látice simple duplicado 11 x 11 en las localidades de Metepec, Tecamac, Montecillo y Chapingo, México, y se hizo análisis de componentes principales en los caracteres: días a floración masculina y femenina, altura de planta y de mazorca, número de plantas y de mazorcas, y diámetro y longitud de mazorca, para conocer la dispersión gráfica de las poblaciones y la clasificación o agrupación de las mismas. Se utilizó el promedio de grupo, y como medida de disimilitud el complemento del coeficiente de correlación (rc) del dendrograma correspondiente. Se encontraron siete agrupaciones a una distancia rc de 0.70, con base en la variabilidad fenotípica característica de las poblaciones. Los grupos G1, G4 y G7 fueron considerados como poblaciones nuevas, adaptadas a Valles Altos Centrales de México. Al usar como referencia a poblaciones cuya raza principal es conocida, fue posible determinar relaciones de parentesco de las poblaciones provenientes del Valle de Toluca: Acambay, Stgo. Yeche, Ixtlahuaca, Jiquipilco y Almoloya de Juárez, y de las colectas: Col-3228, Col- 3364, Col-3359, Col-499, Col-1288, Col-1444, Col-568, Col-1396, Col- 477, Col-1296 y Col-1439. También se determinaron agrupaciones y asociaciones de maíces criollos anteriormente desconocidas.
Evaluación de maíces precoces e intermedios en valles altos centrales de méxico. i. poblaciones sobresalientes
Felipe Nava Peralta,Josu00E9 Apolinar Meju00EDa Contreras,Fernando Castillo Gonzu00E1lez,Josu00E9 Domingo Molina Galu00E1n
Revista fitotecnia mexicana , 2000,
Abstract:
Modos de mercantilización del agua: Un análisis de contraste sobre la regulación desde el Estado y la visión pro empresarial en boga
De Alba,Felipe; Nava,Luzma;
Argos , 2009,
Abstract: from a theoretical approach, this article presents a review of cases of neoliberal water management in developed countries. we establish a contrast relation - but no comparative -with three other cases of water service management in some latin-american countries. the objective is to discuss the process of modernization of the latin american states with respect to hydric resources management and to explore the hypothetical latin american administrations modernization reasons by following an external example, making abstraction of their own local premises. we conclude the management pro entrepreneurial of water public services is the cause of social revolts in divers regions, and in a way, take advantage of the conjunctures to establish new decisional schemes of strategic management.
Efecto de dos Especies de árboles Remanentes y de un Pasto en la Capacidad Amortiguadora del PH del Suelo en un Ecosistema Tropical Estacional
Maribel Nava Mendoza,Leopoldo Galicia,Felipe García Oliva
Boletín de la Sociedad Botánica de México , 2000,
Abstract:
Synthesis and Structural Characterization of Hydroxyapatite-Wollastonite Biocomposites, Produced by an Alternative Sol-Gel Route  [PDF]
Martín A. Encinas-Romero, Jesús Peralta-Haley, Jesús L. Valenzuela-García, Felipe F. Castillón-Barraza
Journal of Biomaterials and Nanobiotechnology (JBNB) , 2013, DOI: 10.4236/jbnb.2013.44041
Abstract:

Hydroxyapatite is a type of calcium phosphate-based material with great interest for biomedical applications, due to the chemical similarity between this material and the mineral part of human bone. However, synthetic hydroxyapatite is essentially brittle; the practice indicates that the use of hydroxyapatite without additives for implant production is not efficient, due to its low strength parameters. In the present work, biocomposites of hydroxyapatite-wollastonite were synthesized by an alternative sol-gel route, using calcium nitrate and ammonium phosphate as precursors of hydroxyapatite, and high purity natural wollastonite was added in ratios of 20, 50 and 80 percent by weight immersed in aqueous medium. Formation of hydroxyapatite occurs at a relatively low temperature of about 350?C, while the wollastonite remains unreacted. After that, these biocomposites were sintered at 1200?C for 5 h to produce dense materials. The characterization techniques demonstrated the presence of hydroxyapatite and wollastonite as unique phases in all products.

La Havane et la Ville de Mexico: une métropolisation par le patrimoine
Le Bel, Pierre-M.;De Alba, Felipe;Nava, Luzma Fabiola;
Intera??es (Campo Grande) , 2008, DOI: 10.1590/S1518-70122008000100008
Abstract: the studies on the phenomenon of metropolisation relate especially to the very great urban centres of the more "developed" countries. this article shows that it is also possible to see this phenomenon at work in a city of the "south", which is in addition in a "socialist" context. by comparing the strategies of development and territorial management based on business holdings of the city of mexico and havana, we show how the patrimonial rehabilitation plays a part in the wider strategy of the mexican capital and how it is the main way for the cuban city to participate to the network of world cities.
LOS ORíGENES DE LA CIVILIZACIóN MIXTECA (The Origins of the Mixtec Civilization)
Andrew K. Balkansky,Felipe de Jesús Nava Rivera,M.a Teresa Palomares Rodríguez
Arqueología Iberoamericana , 2009,
Abstract: La cultura de la Mixteca Alta, en el actual estado de Oaxaca, México, es conocida por su desarrollo durante la época del Posclásico; no obstante estudios recientes han abordado sus orígenes en sitios del Formativo Temprano, Medio y Tardío, aportando una gran gama de datos sobre los inicios de una de las civilizaciones más importantes de Mesoamérica. Los primeros mixtecos ya presentaban características culturales singulares y de identidad, sin embargo también contaban con rasgos similares a sitios tempranos de otras regiones, lo cual los ubica como parte de una dinámica cultural regional e interregional. El estudio sobre los cambios culturales de una organización aldeana a un centro urbano o ciudad, es analizado a través de dos sitios de la Mixteca Alta: Huamelulpan y Tayata. La evidencia de cambios estructurales importantes en el sitio Tayata, durante el Formativo Medio, la hemos relacionado con el desarrollo de nuevos centros políticos en la Mixteca Alta, asimilables a un estado urbano, como lo fue Huamelulpan. Estos acontecimientos se produjeron paralelamente a la aparición de sociedades complejas en el Valle de Oaxaca, como la relación San José Mogote-Monte Albán. A través del estudio de estos procesos culturales, se podrán producir nuevos datos para conocer y entender de una mejor manera los orígenes y desarrollo de la civilización mixteca, así como la relación con el resto de Oaxaca y Mesoamérica desde tiempos tempranos. ENGLISH: The Prehispanic culture of the Mixteca Alta, in the current state of Oaxaca, Mexico, is known for its development during the Postclassic, but recent archaeological research is providing new insights into the origins of the Mixtec civilization thousands of years prior to Spanish contact. The first Mixtecos had unique cultural characteristics, but also had features similar to other early Mesoamerican societies, linking them to a wider set of contacts and cultural dynamics. The transition from village-based societies to urban states in the Mixteca Alta is apparent from a comparison of Tayata to its successor site of Huamelulpan. These events occurred in parallel with the emergence of complex societies in the Valley of Oaxaca. These parallels suggest that in addition to understanding the early history of the Mixtec, our studies are revealing general processes of social evolution.
Mariliasuchus robustus, um Novo Crocodylomorpha (Mesoeucrocodylia) da Bacia Bauru, Brasil.
Pedro Henrique Nobre,Ismar de Souza Carvalho,Felipe Mesquita de Vasconcellos,Willian Roberto Nava
Anuário do Instituto de Geociências , 2007,
Abstract: Herein is described a new species of a Crocodylomorpha Mesoeucrcodylia belonging to the genus Mariliasuchusfrom the Adamantina Formation (Upper Cretaceous, Turonian-Santonian), Bauru Basin, Brazil. The diagnostic features ofthe new species of Mariliasuchus are related to increased stoutness of the skull, wich is high, short and posteriorlly wide;the posterior region of the skull is almost as high as wide. The rostrum is straight, high, and rectangular in cross-section,with a convex dorsal surface, bearing no signs of a antorbital fenestrae. The orbits are large and laterally positioned in the skull. The external nares are forward oriented. The dentition presents pointed anterior teeth (incisiform), a hypertrophied caniniform and a low and globular post-caniniform teeth. The mandible is robust and display a strong vertical bending in its anterior and posterior ends.
Modelo para la estimación de tres parámetros ruminales biológicos
Vargas-Villamil,Luis; Ku-Vera,Juan; Vargas-Villamil,Felipe; Medina-Peralta,Salvador;
Interciencia , 2004,
Abstract: a mechanistic deterministic dynamic model (turix v1.0) was described that is useful as the base of a regression function during the fitting of three parameters associated with a closed system of ruminal bacterial growth. the model parameters estimated are: km,sml describes the performance of the substrate uptake process, klm describes the performance of the bacterial growth from an intermediate metabolite, and ypagv,fs describes the performance of the fermentation products microbial yield. the model of 11 state variables is based on the concepts of monod, michaelis-menten and black box models, as well as on available information. this model does not use the steady state assumption on biomass and fermentation products variable states and assumes that the concentration of the microbial substrate is directly proportional to itself and to the microbial biomass concentration, as well as to the presence of an intermediate metabolite. besides, it is assumed that the biomass and volatile fatty acids concentration, within the system, are a function of an intermediate metabolite. to describe the system performance three sub-models were developed: feed degradation, bacterial growth and bacterial fermentation. the parameters were estimated solving a regression problem which involves a set of differential equations. the basic concepts utilized during the development of the turix model are discussed. the model was able to adjust the km, sml, klm and ypagv, sf parameters related with kinetic process and fermentation products which are useful to understand a close system of ruminal bacterial growth.
Evaluación de un sistema ruminal basado en ca?a de azúcar mediante un modelo dinámico mecanístico
Vargas-Villamil,Luis; Ku-Vera,Juan; Vargas-Villamil,Felipe; Medina-Peralta,Salvador;
Interciencia , 2005,
Abstract: a mechanistic dynamic model (turix v 1.0) that involves differential equations and in situ and in vitro data, was used for estimating the ruminal parameters for three sugar cane (cz) treatments. the results for the treatment, integral cane (ci), neutral detergent fiber and acid detergent fiber biomass (m) concentration, were a) km, sml= 16.28, 49.20 and 20.86ml/h per mgm; b) klm= 9.99e+03, 9.92e+03 and 9.98e+03/h; c) ypagv, sf= 0.72, 0.28 and 0.14g/g; and d) the root mean square= 3.86e-03, 2.85e-03 y 1.87e-03, respectively. contrary to findings by some authors, the results indicated that a slow microbial substrate uptake and a low m yield for ic exists. the m performance in ci treatment at the first hours suggests a fast soluble carbohydrate uptake as a consequence of a high carbohydrate concentration. the results imply low m surpass that it could be one of the causes of low performance in ruminants eating sugar cane. additional work is required to evaluate the turix v 1.0 model utility in the feed analysis but the work raises a new approach in the ruminal systems evaluation.
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