Alterações na transmitância UV-Visível induzidas pelo uso de lentes de contacto de silicone-hidrogel

Fundação para a Ciência e a Tecnologia (FCT) through Centro de Física da U

Phylogenetic Networks and Parameters Inferred from HIV Nucleotide Sequences of High-Risk and General Population Groups in Uganda:Implications for Epidemic Control

Phylogenetic inference is useful in characterising HIV transmission networks and assessing where prevention is likely to have the greatest impact. However, estimating parameters that influence the network structure is still scarce, but important in evaluating determinants of HIV spread. We analyzed 2017 HIV pol sequences (728 Lake Victoria fisherfolk communities (FFCs), 592 female sex workers (FSWs) and 697 general population (GP)) to identify transmission networks on Maximum Likelihood (ML) phylogenetic trees and refined them using time-resolved phylogenies. Network generative models were fitted to the observed degree distributions and network parameters, and corrected Akaike Information Criteria and Bayesian Information Criteria values were estimated. 347 (17.2%) HIV sequences were linked on ML trees (maximum genetic distance ≤4.5%, ≥95% bootstrap support) and, of these, 303 (86.7%) that consisted of pure A1 (n = 168) and D (n = 135) subtypes were analyzed in BEAST v1.8.4. The majority of networks (at least 40%) were found at a time depth of ≤5 years. The waring and yule models fitted best networks of FFCs and FSWs respectively while the negative binomial model fitted best networks in the GP. The network structure in the HIV-hyperendemic FFCs is likely to be scale-free and shaped by preferential attachment, in contrast to the GP. The findings support the targeting of interventions for FFCs in a timely manner for effective epidemic control. Interventions ought to be tailored according to the dynamics of the HIV epidemic in the target population and understanding the network structure is critical in ensuring the success of HIV prevention programs

Origin of the inverse spin-switch behavior in manganite/cuprate/manganite trilayers

We studied ferromagnet/superconductor/ferromagnet trilayers based on La_(0.7)Ca_(0.3)MnO_(3) manganite and YBa_(2)Cu_(3)O_(7−δ) (YBCO) high-T_(c) cuprate with magnetoresistance and magnetization measurements. We find an inverse superconducting spin-switch behavior, where superconductivity is favored for parallel alignment of the magnetization in the ferromagnetic layers. We argue that this inverse superconducting spin switch originates from the transmission of spin-polarized carriers into the superconductor. In this picture, the thickness dependence of the magnetoresistance yields the spin-diffusion length in YBCO as 13 nm. A comparison of bilayers and trilayers allows ruling out the effect of the stray fields of the domain structure of the ferromagnet as the source of the inverse superconducting spin switch

Elaboración de aplicaciones interactivas para la docencia en el grado Grado de Telecomunicación

En este trabajo se muestran los avances realizados en el desarrollo de aplicaciones basadas en laboratorios virtuales para el estudio de la Acústica en el Grado de Telecomunicación. En particular se muestra la extensión de la aplicación VSLM accesible vía on-line y de carácter libre. Esta aplicación está implementada en lenguaje MATLAB y se basa en una interfaz gráfica sencilla que permite simular el funcionamiento de un sonómetro offline. El módulo incorporado a la aplicación permite calcular el tiempo de reverberación y una serie de parámetros relacionados con el mismo para poder caracterizar acústicamente salas y recintos. De forma paralela se muestran los avances realizados en la mejora de la aplicación implementada con anterioridad por los autores dedicada al estudio de las ondas mecánicas en barras con diferentes condiciones de contorno. La aplicación estaba implementada inicialmente en MATLAB para la parte gráfica y el interfaz, mientras que la parte de cálculo se realizó en C++. En este trabajo se muestran los resultados iniciales y la toma de contacto para la unificación de la interfaz y el código que implementa el método numérico en C++ mediante la librería Qt.En este trabajo se muestran los avances realizados en el desarrollo de aplicaciones basadas en laboratorios virtuales para el estudio de la Acústica en el Grado de Telecomunicación. En particular se muestra la extensión de la aplicación VSLM accesible vía on-line y de carácter libre. Esta aplicación está implementada en lenguaje MATLAB y se basa en una interfaz gráfica sencilla que permite simular el funcionamiento de un sonómetro offline. El módulo incorporado a la aplicación permite calcular el tiempo de reverberación y una serie de parámetros relacionados con el mismo para poder caracterizar acústicamente salas y recintos. De forma paralela se muestran los avances realizados en la mejora de la aplicación implementada con anterioridad por los autores dedicada al estudio de las ondas mecánicas en barras con diferentes condiciones de contorno. La aplicación estaba implementada inicialmente en MATLAB para la parte gráfica y el interfaz, mientras que la parte de cálculo se realizó en C++. En este trabajo se muestran los resultados iniciales y la toma de contacto para la unificación de la interfaz y el código que implementa el método numérico en C++ mediante la librería Qt.Peer ReviewedPostprint (published version

Endothelium-Derived Netrin-4 Supports Pancreatic Epithelial Cell Adhesion and Differentiation through Integrins α2β1 and α3β1

BACKGROUND: Netrins have been extensively studied in the developing central nervous system as pathfinding guidance cues, and more recently in non-neural tissues where they mediate cell adhesion, migration and differentiation. Netrin-4, a distant relative of Netrins 1-3, has been proposed to affect cell fate determination in developing epithelia, though receptors mediating these functions have yet to be identified. METHODOLOGY/PRINCIPAL FINDINGS: Using human embryonic pancreatic cells as a model of developing epithelium, here we report that Netrin-4 is abundantly expressed in vascular endothelial cells and pancreatic ductal cells, and supports epithelial cell adhesion through integrins α2β1 and α3β1. Interestingly, we find that Netrin-4 recognition by embryonic pancreatic cells through integrins α2β1 and α3β1 promotes insulin and glucagon gene expression. In addition, full genome microarray analysis revealed that fetal pancreatic cell adhesion to Netrin-4 causes a prominent down-regulation of cyclins and up-regulation of negative regulators of the cell cycle. Consistent with these results, a number of other genes whose activities have been linked to developmental decisions and/or cellular differentiation are up-regulated. CONCLUSIONS/SIGNIFICANCE: Given the recognized function of blood vessels in epithelial tissue morphogenesis, our results provide a mechanism by which endothelial-derived Netrin-4 may function as a pro-differentiation cue for adjacent developing pancreatic cell populations expressing adhesion receptors α2β1 and α3β1 integrins

Metal-macrofauna interactions determine microbial community structure and function in copper contaminated sediments

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