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Search Results: 1 - 10 of 13948 matches for " Zu?iga Rengifo Nestor Javier "
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LAS CONCEPCIONES DE LA NATURALEZA DE DARWIN Y GOETHE, DISCUTIDAS POR TRES FILóSOFOS ALEMANES (NIETZSCHE, CASSIRER Y SIMMEL)
Zuiga Rengifo Nestor Javier
Acta Biológica Colombiana , 2009,
Abstract: RESUMEN En este artículo se presentan las semejanzas y diferencias entre las concepciones de la naturaleza de Darwin y Goethe, discutidas por tres filósofos Alemanes: Friedrich Nietzsche, Ernst Cassirer y Georg Simmel. La discusión se centra principalmente en reconocer el método histórico del cambio caprichoso funcional por parte de los tres filósofos como un principio estructuralista de la metodología histórica y las diferencias sobre los enfoques explicativos, El goethiano morfológico y el darwiniano funcionalista. Nietzsche y Cassirer integran en sus filosofías aspectos de la teoría morfológica goethiana, y aunque reconocen en la teoría de Darwin la importancia de la explicación histórica, rechazan lo que ellos consideran la permanencia de la explicación teleológica en la teoría de Darwin. Simmel establece una relación entre las concepciones de Goethe y Darwin por medio del concepto de acción. Palabras clave: Descendencia con modificación, Metamorfosis, Cambio caprichoso funcional, Filosofía alemana, Acción ABSTRACT The conceptions of the nature of Darwin and Goethe, discussed by three German philosophers (Nietzsche, Simmel and Cassirer)
PLANTAS DOBLE HAPLOIDES GENERADAS POR CRUZA INTERGENERICA DE TRIGO x MAIZ
Jobet,Claudio; Zuiga,Javier; Campos de Quiroz,Hugo;
Agricultura Técnica , 2003, DOI: 10.4067/S0365-28072003000300012
Abstract: the use of double haploid techniques in plant breeding has the potential of shortening genetic improvement cycles in comparison to conventional methods, by means of the fast production (one cycle) of homozygous lines derived from segregant populations, which facilitates rapid homogenization and genetic stabilization. the parental material used (f3) was previously selected under field conditions. a high level of efficiency was reached in obtaining embryos (31.1%), which were rescued and germinated in vitro cultivationto later, by means of duplication via colchicine, to obtain more than 1000 double haploid wheat plants.
PLANTAS DOBLE HAPLOIDES GENERADAS POR CRUZA INTERGENERICA DE TRIGO x MAIZ Double haploid plants generated by intergeneric wheat x maize crosses
Claudio Jobet,Javier Zuiga,Hugo Campos de Quiroz
Agricultura Técnica , 2003,
Abstract: El uso de la técnica de dobles haploides en mejoramiento de plantas tiene el potencial de acortar los ciclos de mejoramiento genético en comparación a los métodos convencionales, mediante la producción rápida (un ciclo) de líneas homocigóticas provenientes de poblaciones segregantes, lo que conlleva a la rápida homogeneización y estabilización genética. El material utilizado (F3) en este trabajo fue previamente seleccionado bajo condiciones de campo. Se alcanzó una alta eficiencia en la obtención de embriones (31%) los cuales fueron rescatados y germinados in vitro para posteriormente, por medio de duplicación vía colchicina, obtener mas de 1.000 plantas de trigo doble haploides. The use of double haploid techniques in plant breeding has the potential of shortening genetic improvement cycles in comparison to conventional methods, by means of the fast production (one cycle) of homozygous lines derived from segregant populations, which facilitates rapid homogenization and genetic stabilization. The parental material used (F3) was previously selected under field conditions. A high level of efficiency was reached in obtaining embryos (31.1%), which were rescued and germinated in vitro cultivationto later, by means of duplication via colchicine, to obtain more than 1000 double haploid wheat plants.
Estimates of Carbon Reservoirs in High-Altitude Wetlands in the Colombian Andes
Enrique Javier Pe?a,Harrison Sandoval,Orlando Zuiga,Alba Marina Torres
Journal of Agriculture and Rural Development in the Tropics and Subtropics , 2009,
Abstract: The observed increase in emission of greenhouse gases, with attendant effects on global warming, have raised interests in identifying sources and sinks of carbon in the environment. Terrestrial carbon (C) sequestration involves capture of atmospheric C through photosynthesis and storage in biota, soil and wetlands. Particularly, wetland systems function primarily as long-term reservoirs for atmospheric carbon dioxide (CO2) and as sources of atmospheric methane (CH4). The objective of this study was to evaluate the patterns of carbon reservoirs in two high-altitude wetlands in the central Andean mountain of Colombia. Carbon cycle in both systems is related mainly with the plant biomass dynamics from the littoral zone. Thus, total organic carbon concentrate an average up to 329 kg of N ha-1 and 125 kg of P ha-1 every year vs only 17 kg N ha-1 and 6 kg P ha-1 in the water column of the limnetic zone in the wetland, evidencing spatial differences in carbon concentrations for these types of ecosystems. Results revealed that these systems participate in the balance and sequestration of carbon in the Colombian Andes.
El cálculo en carreras de ingeniería: un estudio cognitivo
Zuiga, Leopoldo;
Revista latinoamericana de investigación en matemática educativa , 2007,
Abstract: this paper reports a cognitive study of a qualitative character in relation to the learning of the two variable functions and partial derivative concepts in the engineering context. it defends the fact that didactic settings in context can be conducive to a logical meaningful learning for the student with sense in the future professional area. this motivated us to research what happened at cognitive levels for students in this type of didactic environment. the theoretical framework is described by the study of cognitive functioning in a mental act of learning (the process of resolving problem). the analysis reports the experience which results in the implementation of didactic setting designs with one group of engineering students.
Estimando un Modelo de 2 Factores del Tipo
Sergio Zu?±iga
Revista de Análisis Económico (RAE) , 1999,
Abstract: In this article we estimate a two-factor model for the risk-free term structure yield in Chile. These factors are the short rate and the central tendency that are not directly estimable. Both factors follow an Ito stochastic process. In the solution of the model we follow the Balduzzi et al. (1996) specification, which provides an estimation procedure that do not depend on the parametric specification of the second factor and an "exponential affine" solution type that allows to estimate the model by mean of only one equation. The data used in this study is the average weekly yields of the bonds "Bonos de Reconocimiento" (BR) of the Chilean stock exchange during May 1993 and December 1997. The results show that when we use a stochastic level for the long term rates the yields adjust better than the case when this level is constant. Also, the speed of the reversion process increases due to the better performance of the short term rate. In addition, using an ARCH specification for the rate volatility we found additional evidence that the variance of the rates. In this article we estimate a two-factor model for the risk-free term structure yield in Chile. These factors are the short rate and the central tendency that are not directly estimable. Both factors follow an Ito stochastic process. In the solution of the model we follow the Balduzzi et al. (1996) specification, which provides an estimation procedure that do not depend on the parametric specification of the second factor and an "exponential affine" solution type that allows to estimate the model by mean of only one equation. The data used in this study is the average weekly yields of the bonds "Bonos de Reconocimiento" (BR) of the Chilean stock exchange during May 1993 and December 1997. The results show that when we use a stochastic level for the long term rates the yields adjust better than the case when this level is constant. Also, the speed of the reversion process increases due to the better performance of the short term rate. In addition, using an ARCH specification for the rate volatility we found additional evidence that the variance of the rates.
El síndrome judicial
Francisco Ciofalo Zuiga
Medicina Legal de Costa Rica , 2000,
Abstract:
JUVENTUD, CRIMEN Y MUERTE: EL NAUFRAGIO DE LOS JOVENES OLVIDADOS
Enrique Zuiga
Archivos de Criminología, Criminalística y Seguridad Privada , 2011,
Abstract:
Conductance in diffusive quasi-one-dimensional periodic waveguides: a semiclassical and random matrix study
Jaime Zuiga Vukusich
Physics , 2012,
Abstract: We study quantum transport properties of finite periodic quasi-one-dimensional waveguides whose classical dynamics is diffusive. The system we consider is a scattering configuration, composed of a finite periodic chain of $L$ identical (classically chaotic and finite-horizon) unit cells, which is connected to semi-infinite plane leads at its extremes. Particles inside the cavity are free and only interact with the boundaries through elastic collisions; this means waves are described by the Helmholtz equation with Dirichlet boundary conditions on the waveguide walls. The equivalent to the disorder ensemble is an energy ensemble, defined over a classically small range but many mean level spacings wide. The number of propagative channels in the leads is $N$. We have studied the (adimensional) Landauer conductance $g$ as a function of $L$ and $N$ in the cosine-shaped waveguide and by means of our RMT periodic chain model. We have found that $$ exhibit two regimes. First, for chains of length $L\lesssim\sqrt{N}$ the dynamics is diffusive just like in the disordered wire in the metallic regime, where the typic ohmic scaling is observed with $ = N/(L+1)$. In this regime, the conductance distribution is a Gaussian with small variance but which grows linearly with $L$. Then, in longer systems with $L\gg\sqrt{N}$, the periodic nature becomes relevant and the conductance reaches a constant asymptotic value $ \sim $. The variance approaches a constant value $\sim\sqrt{N}$ as $L\to\infty$. Comparing the conductance using the unitary and orthogonal circular ensembles we observed that a weak localization effect is present in the two regimes.
Genetic diversity of bovine viral diarrhoea virus (BVDV) from Peru and Chile
St?hl, Karl;Benito, Alfredo;Felmer, Ricardo;Zuiga, Javier;Reinhardt, German;Rivera, Hermelinda;Baule, Claudia;Moreno-López, Jorge;
Pesquisa Veterinária Brasileira , 2009, DOI: 10.1590/S0100-736X2009000100006
Abstract: twenty-five bvdv strains, detected in serum from persistently infected cattle from peru (n=15) and chile (n=10) were genetically characterized. the phylogenetic analysis based on the 5' utr showed that all 25 strains belonged to genotype 1. twenty-three of the strains could further be subdivided into subtype 1b, and two out of ten chilean strains into subtype 1a. in conclusion, in total 23 out of 25 strains analyzed were of genotype 1, subtype 1b. this is the predominant bvdv subtype in many countries all over the world, including usa. the close homology with previously described strains reflects the influence of livestock trade on the diversity of bvdv circulating within and between countries and continents. peru and chile have imported large numbers of cattle from usa and europe, mostly with insufficient or lacking health documentation.
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