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Search Results: 1 - 10 of 254402 matches for " José; Dávalos "
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Análisis de razones financieras en la empresa lechera intensiva: un estudio de caso en el altiplano mexicano
Enrique Villegas Valladares,José Luis Dávalos Flores
Veterinaria México , 2005,
Abstract: En un ambiente de competitividad intensifi cado por la globalización, los márgenes de utilidad tienden a decrecer. Esta circunstancia hace que el análisis de la información fi nanciera tenga especial importancia para la toma de decisiones estratégicas. El propósito de esta investigación es contribuir a la construcción de nuevas referencias para comparar y evaluar el desempe o de empresas lecheras. Con el fi n de alcanzar este propósito se utilizó el método de estudio de caso, a partir del análisis de ocho a os de información fi nanciera de una empresa lechera localizada en el centro de México, que está integrada vertical y horizontalmente, con un sistema de producción estabulado, mil vacas en línea y autosufi ciencia forrajera de 40%. Se emplearon los estados fi nancieros: Posición fi nanciera y de resultados, y se construyeron 22 razones, agrupadas en cuatro categorías: liquidez, apalancamiento, administración de los activos y rentabilidad. Entre los principales resultados destacan que la empresa cuenta con capacidad de pago a corto y largo plazos, fi nancia su operación principalmente con recursos propios, debido a que fue forzada a reducir su deuda como consecuencia de la crisis económica de México posterior a la devaluación del peso en 1994. Las razones que miden la administración de activos muestran que la empresa fi nancia a sus clientes, pero sus proveedores no lo hacen con ella. Los indicadores de rentabilidad presentan razones bajas con tendencia decreciente, lo cual coincide con la implantación del Tratado de Libre Comercio para América del Norte. Al realizar el trabajo se detectó la necesidad de generar información histórica fi nanciera, que permita hacer comparaciones por sector y tama o para llegar a conclusiones contundentes.
Envases de Cartón para Líquidos como Fuente de Fibra Secundaria
Turrado,José; Dávalos,Martha F; Fuentes,Francisco J; Saucedo,Alma R;
Información tecnológica , 2012, DOI: 10.4067/S0718-07642012000300008
Abstract: a new method is proposed for separating fiber material from the main components of cartonboard commonly used for storing liquids and for evaluating the advantages and disadvantages of this material as fiber sources for paper manufacture. the mechanical resistance of the cartonboard has been reduced by hydration using naoh to accelerate the process. this process destroys hydrogen bonding that joint fiber-fiber. the process allows recovering 92% of the existing fiber in the carton packaging , which makes this material a potential alternative as fibber source for the manufacture of paper. the recovered material contains a high quantity of stickies, although it is possible to reduce this amount to levels that allows using the recovered fiber in paper manufacture.
Desarrollo de un registro genético preventivo automatizado de una enfermedad autosómica dominante
Iris Rojas Betancourt,Graciela Pantoja Varona,José M Dávalos Iglesias,Isidro Cendán Mu?iz
Revista Cubana de Investigaciones Biom??dicas , 1999,
Abstract: Se presenta la metodología aplicada para el desarrollo de un registro genético preventivo para una enfermedad genética autosómica dominante, tomando como base la enfermedad poliquística renal autosómica dominante. Se describe el modelo de historia genética familiar dise ado, los métodos de acceso y seguimiento, así como el programa de computación creado para la automatización del registro, los cuales pudieran aplicarse en el estudio de otras enfermedades con características similares. Se exponen algunas aplicaciones y utilidades de este registro. The methodology used to develop a genetic preventive register for an autosomal dominant genetic disease, taking as a basis the autosomal dominant polycystic kidney disease, is presented. The model designed fot the genetic family history, the access and follow-up methods and the computer program created for the automation of the register, which may be applied to the study of other disseases with similar characteristics, are described. The usefulmess and some of the applications of this register are explained.
Envases de Cartón para Líquidos como Fuente de Fibra Secundaria Liquid Packaging Boards as Source of Secondary Fibers
José Turrado,Martha F Dávalos,Francisco J Fuentes,Alma R Saucedo
Información Tecnológica , 2012,
Abstract: Se propone un método para separar la fibra de los componentes principales del envase de cartón para líquidos y para evaluar las ventajas y desventajas del empleo de esta materia prima como fuente de fibras secundarias en la fabricación de papel. La resistencia mecánica del envase postconsumo se reduce por hidratación utilizando NaOH. Este proceso destruye los puentes de hidrógeno que unen fibra-fibra. El procedimiento permite rescatar 92% de fibra existente en el envase, por ello este material se ubica como potencial alternativa de fuente de fibra secundaria para la fabricación de papel. El material recuperado registra un alto contenido de material adhesivo (stickies), aunque es factible reducir esta cantidad a niveles que permiten su utilización en la fabricación de papel. A new method is proposed for separating fiber material from the main components of cartonboard commonly used for storing liquids and for evaluating the advantages and disadvantages of this material as fiber sources for paper manufacture. The mechanical resistance of the cartonboard has been reduced by hydration using NaOH to accelerate the process. This process destroys hydrogen bonding that joint fiber-fiber. The process allows recovering 92% of the existing fiber in the carton packaging , which makes this material a potential alternative as fibber source for the manufacture of paper. The recovered material contains a high quantity of stickies, although it is possible to reduce this amount to levels that allows using the recovered fiber in paper manufacture.
A comparison between two brine shrimp assays to detect in vitro cytotoxicity in marine natural products
José Carballo, Zaira L Hernández-Inda, Pilar Pérez, María D García-Grávalos
BMC Biotechnology , 2002, DOI: 10.1186/1472-6750-2-17
Abstract: The bioactivity of the isopropanolic (2-PrOH) extracts of 14 species of marine invertebrates and 6 species of macroalgae was evaluated with the shrimp lethality assay (lethality assay), as well as with another assay based on the inhibition of hatching of the cyst (hatchability assay). The extracts were also assayed for cytotoxicity against two human cell lines, lung carcinoma A-549 and colon carcinoma HT-29, in order to assess the sensitivity of the shrimp assays to detect cytotoxic activity.Two sponges (Hyatella sp, Dysidea sp.), two gorgonians (Pacifigorgia adamsii, Muricea sp.), one tunicate (Polyclinum laxum), and three echinoderms (Holothuria impatiens, Pseudoconus californica and Pharia pyramidata) showed a strong cytostatic (growth inhibition) and cytotoxic effect. The hatchability assay showed a strong activity in 4 of the species active against the two human cell lines tested (Hyatella sp, Dysidea sp., Pacifigorgia adamsii and Muricea sp.), and the lethality assay also showed a high lethality in 4 of them (Pacifigorgia adamsii, Muricea sp., Polyclinum laxum, and Pharia pyramidata). Each bioassay detected activity in 50% of the species that were considered active against the two human cell lines tested. However, the simultaneous use of both bioassays increased the percentage to 75%.Our results seem consistent with the correlation previously established between cytotoxicity and brine shrimp lethality in plant extracts. We suggest using both bioassays simultaneously to test natural marine products for pharmacological activity.The shrimp lethality assay was proposed by Michael et al. [1], and later developed by Vanhaecke et al. [2], and Sleet and Brendel [3]. It is based on the ability to kill laboratory-cultured Artemia nauplii brine shrimp. The assay is considered a useful tool for preliminary assessment of toxicity [4], and it has been used for the detection of fungal toxins [5], plant extract toxicity [6], heavy metals [7], cyanobacteria toxins [8], pestici
Reconstrucción de la precipitación estacional para el barlovento de la Sierra Madre Occidental con anillos de crecimiento de Pseudotsuga menziesii (Mirb.) Franco
Villanueva Díaz, José;Fulé, Peter Z.;Cerano Paredes, Julián;Estrada ávalos, Juan;Sánchez Cohen, Ignacio;
Ciencia forestal en México , 2009,
Abstract: northwest mexico is a leader region in terms of agriculture, but is highly dependant on aquifers and on surface water from watersheds of the sierra madre occidental draining toward the pacific. paleoclimate studies to determine historical hydroclimate variability are rare in this region. two earlywood chronologies of pseudotsuga menziesii were developed for mixed-conifer stands in the sierra madre occidental. one of them is 531 years in length (1472-2002) and is located in tutuaca, chihuahua; the second one located in el cócono, guanaceví, durango, is 554 years length (1449-2002). the earlywood chronologies are significantly related to the seasonal winter-spring precipitation (october-may) and respond similarly (r = 0.61, p<0.00001; period 1472-1999) to precipitation. they detect drought periods of greater intensity than those witnessed during the 20th century. the most intensive and prolonged drought episodes were reconstructed for the 1560s, 1700s, and 1770s. historical archives indicate that some of these droughts were related to famine and epidemic outbreaks. the warm phase of enso has a strong signal in this region and produces above normal precipitation, whereas the cold phase is related to drought. moreover, the enso signal is not stable and changes through time as indicated by the correlation between precipitation and the tropical rainfall index. the development of a greater number of tree-ring chronologies is basic to understand the hydroclimate variability of the warm season (summer), which is of greater hydrological importance.
Hongos macroscópicos de la Sierra de Quila, Jalisco, México: diversidad y similitud fungística
Fierros,María de la Luz; Navarrete-Heredia,José Luis; Guzmán-Dávalos,Laura;
Revista de Biología Tropical , 2000,
Abstract: diversity and similarity of macrofungi of sierra de quila, jalisco, méxico were analized in three different kinds of vegetation. fungal diversity in the area is high. the pine-oak and cloud forests, were more diverse in their community structure than the oak forest. similarity among the three kinds of vegetation was low, there are few species share among them; pine-oak and cloud forests show higher affinity than oak forests. this pattern of similarity is a general condition for others regions with environmental conditions similar to sierra de quila.
Registro genético preventivo automatizado de la enfermedad poliquística renal autosómica dominante
Iris Rojas Betancourt,José M. Dávalos Iglesias,Isidro Cendán Mu?iz,Víctor Tamayo Chang
Revista Cubana de Medicina , 1998,
Abstract: Se decidió crear un registro genético automatizado de la enfermedad poliquística renal autosómica dominante ya que es un fenómeno común y existe un programa nacional para su atención. Se empleó una metodología desarrollada por los autores para facilitar el estudio y seguimiento sistemático de muchas familias y su atención genética. Se logró en los primeros 3 a os de funcionamiento, la caracterización clínica, genética y epidemiológica de 111 familias y se comprobó la factibilidad de la metodología desarrollada. Se les ofreció asesoramiento genético y seguimiento a 2 870 personas afectadas o con riesgo y se dise aron varias investigaciones que contribuyeron a mejorar su atención y seguimiento. It was decided to created an automated genetic registry of the autosomal dominant polycystio kidney disease, taking into account that it is a common phenomenon and that there is a national program for its attention. A methodology developed by the authors was used to enable the study and systematic follow-up of many families and their genetic attention. The clinical, genetic and epidemiological characterization of 111 families was attained during the first three years and the feasibility of the methodology was proved. 2 870 affected patients or at risk received genetic counseling and follow-up. Several investigations were designed to improve their attention and follow-up.
Hongos macroscópicos de la Sierra de Quila, Jalisco, México: diversidad y similitud fungística
María de la Luz Fierros,José Luis Navarrete-Heredia,Laura Guzmán-Dávalos
Revista de Biología Tropical , 2000,
Abstract: Se analizó a diversidad y similitud de los hongos macroscópicos de la Sierra de Quila, Jalisco, México en tres tipos de vegetación. En general la diversidad fúngica en la zona fue elevada. Los bosques de pino-encino y mesófilo de monta a resultaron ser significativamente más diversos en cuanto a su estructura de comunidad en relación conl bosque de encino. La similitud fungística entre los tres tipos de vegetación fue baja y son pocas las especies compartidas entre sí, resultando más afines el bosque de pino-encino y el mesófilo de monta a. Este patrón de similitud es una condición general para otras regiones que presentan características similares a las de la zona estudiada. Diversity and similarity of macrofungi of Sierra de Quila, Jalisco, México were analized in three different kinds of vegetation. Fungal diversity in the area is high. The pine-oak and cloud forests, were more diverse in their community structure than the oak forest. Similarity among the three kinds of vegetation was low, there are few species share among them; pine-oak and cloud forests show higher affinity than oak forests. This pattern of similarity is a general condition for others regions with environmental conditions similar to Sierra de Quila.
La ca?a de azúcar: ?una amarga externalidad?
Dávalos álvarez,Eleonora;
Desarrollo y Sociedad , 2007,
Abstract: there have been many studies on the relationship between air pollution and respiratory health, but these have usually been conducted in large cities of developed countries, where pollution is associated to mobile and fi xed-source emissions. this study was conducted in a small colombian city of fewer than 300,000 residents, but with substantial air pollution from sugar cane burning. to establish how sugar cane burning relates to respiratory health, a lineal function was used to describe the relationship between controlled sugar cane burns and the concentration of particles less ten microns (pm10), and a concentration-response function to relate the concentration of pm10 and the occurrence of respiratory disease. the relationship between burning and pm10 concentration was estimated with a least-square model, while a poisson model described the relationship between pm10 concentration and disease occurrence. both estimates used daily time series data between february and june for each variable. a positive association between sugar cane burns and the concentration of pollutants was found, as well as a positive relationship between concentrations of pollutants and the number of daily hospital admissions for acute respiratory illnesses (ari). these analyses document for the fi rst time the effects of controlled sugar cane burns on public health in colombia.
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