2,690 research outputs found
Modified Debye-Huckel Electron Shielding and Penetration Factor
Screened potential, modified by non standard electron cloud distributions
responsible for the shielding effect on fusion of reacting nuclei in
astrophysical plasmas, is derived. The case of clouds with depleted tails in
space coordinates is discussed. The modified screened potential is obtained
both from statistical mechanics arguments based on fluctuations of the inverse
of the Debye-Huckel radius and from the solution of a Bernoulli equation used
in generalized statistical mechanics. Plots and tables useful in evaluating
penetration probability at any energy are provided.Comment: 9 pages, 3 figures, 3 table
Probing the role of point mutations in the cyp51A gene from Aspergillus fumigatus in the model yeast Saccharomyces cerevisiae
Azole-resistant strains of Aspergillus fumigatus have been detected and the underlying molecular mechanisms of resistance characterized. Point mutations in the cyp51A gene have been proved to be related to azole resistance in A. fumigatus clinical strains and with different resistance profiles depending on the amino acid change (G54E, G54V, G54R, G54W, M220V, M220K, M220T, M220I). The aim of this work was to express A. fumigatus cyp51A genes in the yeast Saccharomyces cerevisiae in order to better assess the contribution of each independent amino acid substitution to resistance. A tetracycline regulatable system allowing repression of the endogenous essential ERG11 gene was used. The expression of Aspergillus cyp51A alleles could efficiently restore the absence of ERG11 in S. cerevisiae. In general, S. cerevisiae clones expressing. A. fumigatus cyp51A alleles from azole-resistant isolates showed higher MICs to all azoles tested than those expressing alleles from susceptible isolates. The azole susceptibility profiles obtained in S. cerevisiae upon expression of specific cyp51A alleles recapitulated susceptibility profiles observed from their A. fumigatus origins. In conclusion this work supports the concept that characteristics of specific A. fumigatus cyp51A alleles could be investigated in the heterologous host S. cerevisia
Exploring the role of electrode microstructure on the performance of non-aqueous redox flow batteries
Redox flow batteries are an emerging technology for long-duration grid energy storage, but further cost reductions are needed to accelerate adoption. Improving electrode performance within the electrochemical stack offers a pathway to reduced system cost through decreased resistance and increased power density. To date, most research efforts have focused on modifying the surface chemistry of carbon electrodes to enhance reaction kinetics, electrochemically active surface area, and wettability. Less attention has been given to electrode microstructure, which has a significant impact on reactant distribution and pressure drop within the flow cell. Here, drawing from commonly used carbon-based diffusion media (paper, felt, cloth), we systematically investigate the influence of electrode microstructure on electrochemical performance. We employ a range of techniques to characterize the microstructure, pressure drop, and electrochemically active surface area in combination with in-operando diagnostics performed in a single electrolyte flow cell using a kinetically facile redox couple dissolved in a non-aqueous electrolyte. Of the materials tested, the cloth electrode shows the best performance; the highest current density at a set overpotential accompanied by the lowest hydraulic resistance. We hypothesize that the bimodal pore size distribution and periodic, well-defined microstructure of the cloth are key to lowering mass transport resistance
Geographic mobility and social inequality among Peruvian university students
The purpose of this study was to explore geographic mobility among university students in Peru and to understand how mobility patterns differ by region and by demographic indicators of inequality. The ways that students may be able to move geographically in order to access quality higher education within the educational system can be a driver of equality or inequality, depending on who is able to take advantage. Using data from a university census, we examine how demographic indicators of inequality are related to geographic mobility for university attendance, how prior geographic mobility predicts later mobility for university attendance, and how these relationships differ based on the number and quality of universities in a region. Results show that sociodemographic variables related to social inequality explain a substantial amount of students\u27 postsecondary mobility. However, some of these relationships do not operate in the same way in all of the regions. Depending on the availability of universities and their quality, patterns of association between inequality and geographic mobility change. Implications for higher education policy as well as further research examining geographic mobility and inequality in education are discussed
Caracterização do consumo das carnes caprina e ovina em Alagoas.
bitstream/CPATC-2010/20744/1/doc82.pd
A Novel Mouse Model of Peritoneal Dialysis: Combination of Uraemia and Long-Term Exposure to PD Fluid
Different animal models for peritoneal dialysis (PD) have been used in the past decades to develop PD fluids compatible with patient life and to identify markers of peritoneal fibrosis and inflammation. Only few of those studies have taken into account the importance of uraemia-induced alterations at both systemic and peritoneal levels. Moreover, some animal studies which have reported about PD in a uremic setting did not always entirely succeed in terms of uraemia establishment and animal survival. In the present study we induced uraemia in the recently established mouse PD exposure model in order to obtain a more clinically relevant mouse model for kidney patients. This new designed model reflected both the slight thickening of peritoneal membrane induced by uraemia and the significant extracellular matrix deposition due to daily PD fluid instillation. In addition the model offers the opportunity to perform long-term exposure to PD fluids, as it is observed in the clinical setting, and gives the advantage to knock out candidate markers for driving peritoneal inflammatory mechanisms.Marie Curie actionsPeer Reviewe
Caracterização do consumo das carnes caprina e ovina em Sergipe.
bitstream/CPATC-2010/20745/1/doc84.pd
Caracterização do consumo das carnes caprina e ovina em Sergipe.
A Embrapa Caprinos e Ovinos e com Embrapa Tabuleiros Costeiros desenvolveram no período de 2003 a 2008 o Projeto: estudo da cadeia produtiva de carnes e peles de caprinos e ovinos na Região Nordeste do Brasil. Tal projeto, além de outras áreas, buscava identificar o mercado potencial de carnes e peles para os produtos de origem caprina e ovina. Esta publicação apresenta uma caracterização do mercado consumidor das carnes caprina e ovina na cidade de Aracaju, no Estado de Sergipe. Nela o leitor vai encontrar informações importantes sobre diversos indicadores de mercado, tais como: preço, renda dos consumidores, gosto ou preferência com relação à outras carnes e, mercado potencial dentre outras. Espera- se que estas informações sirvam de referência e apoio a todos os segmentos que compõem esta cadeia produtiva na implantação de projetos que permitam o desenvolvimento sustentável do agronegócio da caprinocultura e da ovinocultura brasileiras.bitstream/CNPC-2010/21838/1/doc84.pd
Caracterização do consumo das carnes caprina e ovina na cidade de Salvador, BA.
bitstream/CPATC-2010/20743/1/doc81.pd
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