42 research outputs found

    Toll-like receptor 4 signaling in liver injury and hepatic fibrogenesis

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    Toll-like receptors (TLRs) are a family of transmembrane pattern recognition receptors (PRR) that play a key role in innate and adaptive immunity by recognizing structural components unique to bacteria, fungi and viruses. TLR4 is the most studied of the TLRs, and its primary exogenous ligand is lipopolysaccharide, a component of Gram-negative bacterial walls. In the absence of exogenous microbes, endogenous ligands including damage-associated molecular pattern molecules from damaged matrix and injured cells can also activate TLR4 signaling. In humans, single nucleotide polymorphisms of the TLR4 gene have an effect on its signal transduction and on associated risks of specific diseases, including cirrhosis. In liver, TLR4 is expressed by all parenchymal and non-parenchymal cell types, and contributes to tissue damage caused by a variety of etiologies. Intact TLR4 signaling was identified in hepatic stellate cells (HSCs), the major fibrogenic cell type in injured liver, and mediates key responses including an inflammatory phenotype, fibrogenesis and anti-apoptotic properties. Further clarification of the function and endogenous ligands of TLR4 signaling in HSCs and other liver cells could uncover novel mechanisms of fibrogenesis and facilitate the development of therapeutic strategies

    J-PLUS: The Javalambre Photometric Local Universe Survey

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    The Javalambre Photometric Local Universe Survey (J-PLUS) is an ongoing 12-band photometric optical survey, observing thousands of square degrees of the Northern Hemisphere from the dedicated JAST/T80 telescope at the Observatorio Astrofisico de Javalambre (OAJ). The T80Cam is a camera with a field of view of 2 deg(2) mounted on a telescope with a diameter of 83 cm, and is equipped with a unique system of filters spanning the entire optical range (3500-10 000 angstrom). This filter system is a combination of broad-, medium-, and narrow-band filters, optimally designed to extract the rest-frame spectral features (the 3700-4000 angstrom Balmer break region, H delta, Ca H+K, the G band, and the Mg b and Ca triplets) that are key to characterizing stellar types and delivering a low-resolution photospectrum for each pixel of the observed sky. With a typical depth of AB similar to 21.25 mag per band, this filter set thus allows for an unbiased and accurate characterization of the stellar population in our Galaxy, it provides an unprecedented 2D photospectral information for all resolved galaxies in the local Universe, as well as accurate photo-z estimates (at the delta z/(1 + z) similar to 0.005-0.03 precision level) for moderately bright (up to r similar to 20 mag) extragalactic sources. While some narrow-band filters are designed for the study of particular emission features ([O II]/lambda 3727, H alpha/lambda 6563) up to z < 0.017, they also provide well-defined windows for the analysis of other emission lines at higher redshifts. As a result, J-PLUS has the potential to contribute to a wide range of fields in Astrophysics, both in the nearby Universe (Milky Way structure, globular clusters, 2D IFU-like studies, stellar populations of nearby and moderate-redshift galaxies, clusters of galaxies) and at high redshifts (emission-line galaxies at z approximate to 0.77, 2.2, and 4.4, quasi-stellar objects, etc.). With this paper, we release the first similar to 1000 deg(2) of J-PLUS data, containing about 4.3 million stars and 3.0 million galaxies at r < 21 mag. With a goal of 8500 deg(2) for the total J-PLUS footprint, these numbers are expected to rise to about 35 million stars and 24 million galaxies by the end of the survey

    DISTRIBUCIÓN Y GRADO DE ESTABLECIMIENTO DE COCHINILLA ROSADA DEL HIBISCO EN NAYARIT, MÉXICO

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    La cochinilla rosada del hibisco (Maconellicoccus hirsutus, Green)(CRH) es una plaga con rápida distribución en las áreas donde se presenta y con un amplio rango de hospederos. Se realizó el análisis de distribución de CRH en el estado de Nayarit, México a partir de los registros del Comité Estatal de Sanidad Vegetal de Nayarit en la campaña contra cochinilla rosada, la información se organizó en una base de datos por localidad, tipo de área, hospedantes y semanas de muestreo. Asimismo, se relacionaron los niveles de infestación presentados con los datos de temperatura y humedad de estaciones climáticas. CRH se hizo presente en Nayarit, México en 2004; para 2009 estaba presente en 16 de los 20 municipios del estado, con preferencia en obelisco (Hibiscus rosa-sinensis), majahua (Hibiscus pernambucensis), huinol (Acacia cymbispina) y guanábano (Annona muricata) como hospedantes y marginada a zonas urbanas. Las condiciones ambientales que prevalecieron cuando ocurrieron los niveles más altos de CRH fueron temperaturas entre 14.61 y 29.1°C, y humedad relativa de 72 %
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