Scaling limits of a tagged particle in the exclusion process with variable diffusion coefficient

We prove a law of large numbers and a central limit theorem for a tagged particle in a symmetric simple exclusion process in the one-dimensional lattice with variable diffusion coefficient. The scaling limits are obtained from a similar result for the current through -1/2 for a zero-range process with bond disorder. For the CLT, we prove convergence to a fractional Brownian motion of Hurst exponent 1/4.Comment: 9 page

Resistencia antimicrobiana de Staphylococcus aislados de la piel de gatos ¿un riesgo para la salud humana?

Actualmente, las patologías dermatológicas son una de las causas deconsulta más frecuentes en la práctica veterinaria de animales pequeños,posiblemente debido a los evidentes signos y lesiones que presentan losanimales: prurito, alopecia y olor desagradable, entre otros.  

Clustering in anomalous files of independent particles

The dynamics of classical hard particles in a quasi one-dimensional channel were studied since the 1960s and used for explaining processes in chemistry, physics and biology and in applications. Here we show that in a previously un-described file made of anomalous, independent, particles (with jumping times taken from, {\psi}_{\alpha} (t) t^(-1-{\alpha}), 0<{\alpha}<1), particles form clusters. At steady state, the percentage of particles in clusters is about, \surd(1-{\alpha}^3), only for anomalous {\alpha}, characterizing the criticality of a phase transition. The asymptotic mean square displacement per particle in the file is about, log^2(t). We show numerically that this exciting phenomenon of a phase transition is very stable, and relate it with the mysterious phenomenon of rafts in biological membranes, and with regulation of biological channels.Comment: main text (13 pages, 4 figures), plus supplementary material (15 pages, 6 figures

Utilización de inmunoreacciones para la detección de Scrapie en Óbex de ovinos provenientes de la XII Región de Chile

Scrapie is an neurodegenerative and infectious disease that affects sheep and goats. The purpose of this study is to compare both tecniques, ELISA and IHC, to determine the application factibility giving the conditions of the laboratory in the country. To develop this assay, fourty obex samples were taken from sheep of the XII Region of Chile and were processed for both techniques ELISA and IHC. The results showed 100% of the samples negative for Scrapie, using both diagnostic methods. Based in obtained and previously reported results, ELISA technique can be recommended to use in massive screening, since yields reliable and rapid test results and IHC is a confirmatory technique. Both techniques are necessary in the creation of current epidemiological surveillance programs in Chile. ELISA and IHC are easily performed given the current laboratories conditions of the Chilean country.    El Scrapie es una enfermedad infecciosa neurodegenerativa que afecta a ovinos y caprinos. Dada la importancia que tiene esta enfermedad es que se desarrolló este estudio enmarcado en la comparación de la técnica de ELISA y la de inmunohistoquímica en el diagnóstico de Scrapie, para determinar la factibilidad de aplicarlas en las condiciones de laboratorio país. Para ello se procesaron 40 muestras de óbex de ovinos en duplicado, provenientes de la XII Región de Chile, las cuales fueron sometidas paralelamente a la técnica de ELISA e IHQ. Como resultados se obtuvo un 100% de muestras negativas a Scrapie, sometidas a ambos métodos diagnósticos. Con los valores informados previamente y los obtenidos en esta investigación, es posible recomendar el ELISA como una técnica utilizable en muestreos masivos, ya que aporta resultados confiables de manera más rápida. La IHQ corresponde a una técnica confirmatoria y que ambas, son necesarias en la creación de programas de vigilancia epidemiológica activa en Chile, siendo factibles de realizar en las actuales condiciones de laboratorio país.  

Alternative reproductive adaptation predicts asymmetric responses to climate change in lizards

Anthropogenic climate change ranks among the major global-scale threats to modern biodiversity. Extinction risks are known to increase via the interactions between rapid climatic alterations and environmentally-sensitive species traits that fail to adapt to those changes. Accumulating evidence reveals the influence of ecophysiological, ecological and phenological factors as drivers underlying demographic collapses that lead to population extinctions. However, the extent to which life-history traits influence population responses to climate change remains largely unexplored. The emerging ‘cul-de-sac hypothesis’ predicts that reptilian viviparity (‘live-bearing’ reproduction), a ‘key innovation’ facilitating historical invasions of cold climates, increases extinction risks under progressively warming climates compared to oviparous reproduction – as warming advances polewards/mountainwards, historically cold-climates shrink, leading viviparous species to face demographic collapses. We present the first large-scale test of this prediction based on multiple lizard radiations and on future projections of climate-based ecological niche models. Viviparous species were found to experience stronger elevational range shifts (and potentially increased extinctions) in coming decades, compared to oviparous lizards. Therefore, our analyses support the hypothesis’s fundamental prediction that elevational shifts are more severe in viviparous species, and highlight the role that life-history adaptations play in the responses of biodiversity to ongoing climate change