Search results for "H30"

OBSTÁCULOS AL APRENDIZAJE DEL CONCEPTO ESTRUCTURANTE EVOLUCIÓN BIOLÓGICA

2014

Se contrastaron los obstáculos en el aprendizaje del concepto evolución biológica reportados en publicaciones especializadas en la enseñanza de las ciencias,  con losen la implementación de un juego para enseñar evolución por selección natural. Lo anterior, se realizó mediante la revisión de antecedentes que permitieron identificar los obstáculos encontrados por otros investigadores y la puesta en marcha de la propuesta didáctica que posibilitó identificar y superar algunos de los mismos. Existen múltiples factores que dificultan la comprensión de la evolución biológica, componentes culturales, iconografía inapropiada, insuficiente preparación de los profesores, estrategias didácticas inade…

Valoración de los Proyectos de Grado sobre Educación Ambiental en la Universidad, Aplicando la Hipótesis de Progresión

2015

Este trabajo  aplica la hipótesis de progresión como metodología para  la valoración de los proyectos de grado de los estudiantes en Educación Ambiental en la Universidad.Se han analizado, los proyectos realizados por los  alumnos de  la licenciatura en Biología y Educación Ambiental, en la Universidad del Quindío, Colombia. Cuyo objetivo  tiene la  formación de profesores para los diferentes niveles educativos. La hipótesis de progresión permite valorar  el cambio conceptual  presentado en los proyectos de grado no como un proceso puntual sino como un proceso de evolución de los contenidos.La investigación  muestra que los Proyectos fin de grado de los estudiantes de Biología y educación A…

Evaluación de la actividad antiherpética in vitro de moléculas híbridas de la combretastatina A4 y diterpenos

2012

Sulfur transfer and activation by ubiquitin-like modifier system Uba4•Urm1 link protein urmylation and tRNA thiolation in yeast.

2017

Urm1 is a unique dual-function member of the ubiquitin protein family and conserved from yeast to man. It acts both as a protein modifier in ubiquitin-like urmylation and as a sulfur donor for tRNA thiolation, which in concert with the Elongator pathway forms 5-methoxy-carbonyl-methyl-2-thio (mcm5s2) modified wobble uridines (U34) in anticodons. Using Saccharomyces cerevisiae as a model to study a relationship between these two functions, we examined whether cultivation temperature and sulfur supply previously implicated in the tRNA thiolation branch of the URM1 pathway also contribute to proper urmylation. Monitoring Urm1 conjugation, we found urmylation of the peroxiredoxin Ahp1 is suppre…

The Putative Metal Coordination Motif in the Endonuclease Domain of Human Parvovirus B19 NS1 Is Critical for NS1 Induced S Phase Arrest and DNA Damage

2012

The non-structural proteins (NS) of the parvovirus family are highly conserved multi-functional molecules that have been extensively characterized and shown to be integral to viral replication. Along with NTP-dependent helicase activity, these proteins carry within their sequences domains that allow them to bind DNA and act as nucleases in order to resolve the concatameric intermediates developed during viral replication. The parvovirus B19 NS1 protein contains sequence domains highly similar to those previously implicated in the above-described functions of NS proteins from adeno-associated virus (AAV), minute virus of mice (MVM) and other non-human parvoviruses. Previous studies have show…

Oxidative Stress and DNA Damage in Human Gastric Carcinoma: 8-Oxo-7'8-dihydro-2'-deoxyguanosine (8-oxo-dG) as a Possible Tumor Marker

2013

We characterized the oxidative stress (OS) status by the levels of reduced/oxidized glutathione (GSH/GSSG), malondialdehyde (MDA) and the mutagenic base 8-oxo-7'8-dihydro-2'-deoxyguanosine (8-oxo-dG) in human gastric carcinoma (HGC) samples and compared the results with normal tissue from the same patients. We also analyzed 8-oxo-dG in peripheral mononuclear cells (PMNC) and urine from healthy control subjects and in affected patients in the basal state and one, three, six, nine and twelve months after tumor resection. The levels of DNA repair enzyme mRNA expression (hOGG1, RAD51, MUYTH and MTH1) were determined in tumor specimens and compared with normal mucosa. Tumor specimens e…

Neutrophils: Between host defence, immune modulation, and tissue injury.

2015

Neutrophils, the most abundant human immune cells, are rapidly recruited to sites of infection, where they fulfill their life-saving antimicrobial functions. While traditionally regarded as short-lived phagocytes, recent findings on long-term survival, neutrophil extracellular trap (NET) formation, heterogeneity and plasticity, suppressive functions, and tissue injury have expanded our understanding of their diverse role in infection and inflammation. This review summarises our current understanding of neutrophils in host-pathogen interactions and disease involvement, illustrating the versatility and plasticity of the neutrophil, moving between host defence, immune modulation, and tissue da…

Control of Murine Cytomegalovirus Infection by γδ T Cells

2015

Infections with cytomegalovirus (CMV) can cause severe disease in immunosuppressed patients and infected newborns. Innate as well as cellular and humoral adaptive immune effector functions contribute to the control of CMV in immunocompetent individuals. None of the innate or adaptive immune functions are essential for virus control, however. Expansion of γδ T cells has been observed during human CMV (HCMV) infection in the fetus and in transplant patients with HCMV reactivation but the protective function of γδ T cells under these conditions remains unclear. Here we show for murine CMV (MCMV) infections that mice that lack CD8 and CD4 αβ-T cells as well as B lymphocytes can control a MCMV i…

Chlamydia trachomatis Infection and Anti-Hsp60 Immunity: The Two Sides of the Coin

2009

Chlamydia trachomatis (CT) infection is one of the most common causes of reproductive tract diseases and infertility. CT-Hsp60 is synthesized during infection and is released in the bloodstream. As a consequence, immune cells will produce anti-CT-Hsp60 antibodies. Hsp60, a ubiquitous and evolutionarily conserved chaperonin, is normally sequestered inside the cell, particularly into mitochondria. However, upon cell stress, as well as during carcinogenesis, the chaperonin becomes exposed on the cell surface (sf-Hsp60) and/or is secreted from cells into the extracellular space and circulation. Reports in the literature on circulating Hsp and anti-Hsp antibodies are in many cases short on detai…

SNPs detection by eBWT positional clustering

2019

Sequencing technologies keep on turning cheaper and faster, thus putting a growing pressure for data structures designed to efficiently store raw data, and possibly perform analysis therein. In this view, there is a growing interest in alignment-free and reference-free variants calling methods that only make use of (suitably indexed) raw reads data. We develop the positional clustering theory that (i) describes how the extended Burrows–Wheeler Transform (eBWT) of a collection of reads tends to cluster together bases that cover the same genome position (ii) predicts the size of such clusters, and (iii) exhibits an elegant and precise LCP array based procedure to locate such clusters in the e…