Papers by Jose Alberto Vargas
Journal of Photochemistry and Photobiology B-biology, 2000
Sensitive, safe and easy-to-use probes for the detection of nucleic acids are urgently called for... more Sensitive, safe and easy-to-use probes for the detection of nucleic acids are urgently called for. To this end we are in the process of developing a fluorescence-based technique to work in homogeneous assay media. We have examined pyrene and fluorescein as fluorescent labels for natural DNA probes. A fraction of the cytosine residues of a single-stranded cDNA was randomly labelled with either pyrene or fluorescein using the bisulfite-catalyzed diamine reaction. Both fluorophores showed fluorescence quenching when the labelled probe was hybridized with its complementary strand and we describe the changes in steady-state fluorescence intensity that occurred upon hybridization. Our results demonstrate that pyrene quenching is more efficient than fluorescein quenching and thus pyrene-labelled probes are more sensitive for detecting and quantifying DNA from natural sources.
Journal of Cross-cultural Psychology, 2005
Implicit trait and contextual theories encompass lay people's beliefs about the longitudinal stab... more Implicit trait and contextual theories encompass lay people's beliefs about the longitudinal stability (vs. instability) of traits; the cross-situational consistency (vs. variability) of behavior; the ability to predict (vs. not predict) individuals' behavior from their traits; the ability to infer traits from few behavioral instances (vs. the difficulty of doing so); and the importance of traits in understanding people (vs. the greater importance of contextual factors such as roles and relationships). Implicit trait and contextual beliefs were investigated in two individualistic cultures, the United States and Australia, and two collectivistic cultures, Mexico and the Philippines. Hypotheses based on an integration of trait and cultural psychology perspectives were supported. The structure of implicit beliefs replicated well, and trait beliefs predicted judgments about crosssituational consistency of behavior in all four cultures. Implicit trait beliefs were stronger, and implicit contextual beliefs weaker, in the United States as compared to Mexico and the Philippines.
Biochemical and Biophysical Research Communications, 2004
Oral administration of sodium tungstate is an e¡ective treatment for diabetes in animal models. W... more Oral administration of sodium tungstate is an e¡ective treatment for diabetes in animal models. We examined the e¡ects of 6 weeks of oral administration of tungstate on glucose transporters (GLUT) in streptozotocin-induced diabetic rat diaphragm. Diabetes decreased GLUT4 expression while tungstate treatment normalized not only GLUT4 protein but also GLUT4 mRNA in the diabetic rats. Furthermore, treatment increased GLUT4 protein in plasma and internal membranes, suggesting a stimulation of its translocation to the plasma membrane. Tungstate had no e¡ect on healthy animals. There were no di¡erences in the total amount of GLUT1 transporter in any group. We conclude that the normoglycemic e¡ect of tungstate may be partly due to a normalization of the levels and subcellular localization of GLUT4, which should result in an increase in muscle glucose uptake. ß
Page 1. Revista Colombiana de Estadıstica Volumen 26 No 2. Págs. 159 a 179. Diciembre 2002 Carta ... more Page 1. Revista Colombiana de Estadıstica Volumen 26 No 2. Págs. 159 a 179. Diciembre 2002 Carta T2 con base en estimadores robustos de los parámetros Sergio Yánez C.* José A. Vargas** Nelfi González A.*** Resumen ...
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Papers by Jose Alberto Vargas