Uso de viscosidade turbulenta constante na predição numérica do assoreamento numa armadilha

A capacidade de predizer taxas de sedimentação e sua distribuição não uniforme em ri os e reservatorios é tarefa não trivial, sendo importante tanto na fase de concepçã o de estudos e projetos como para a gestão ambiental sustentável destes sistemas. A associação de ferramenta computacional para o estudo do transporte sedimentar re presenta um ganho de tempo, e também monetário, permitindo diagnosticar e prognosticar cenários, antecipando medidas de intervenção programadas. Considerando a aplicação intensiva da dinâmica de fluidos computacional nos estudos morfodinâmicos em sistemas reais , com o uso do conceito de água s pouco profundas, este trabalho avalia numericamente o assoreamento inicial em uma armadilha de sedimentos construída em laboratorio, com a utilização de vi scosidade turbulenta constante. Emprega o código Delft3D, desenvolvido pela WL - Delft Hydraulics, i nstituto de pesquisa da Holanda . O modelo hidráulico tem como base as equações de Navier - Stockes, permitindo análises em duas ou três dimensões por incorporar modelos de turbulência . O módulo de transporte de sedimentos tem como base a equação de advecção - difusão, além de contar com as equações semi - empíricas consagradas na literatura. O escoamento hidrodinâmico simulado f oi calibrado para as velocidade s de água medida s em regiões específicas da armadilha, com o uso de velocimetria a laser. A simulação do assoreamento foi iniciada a partir da calibração hidrodinâmica, configurada para os dados conhecidos do sedimento utilizado . Os resultados obtidos apresentaram boa concordância entre o assoreamento medido e simulado de c urto período. A extensão do período simulado apontou para uma divergência entre os padrões de deposiçã

Accuracy of Genomic Selection Methods in a Standard Data Set of Loblolly Pine (Pinus taeda L.)

Genomic selection can increase genetic gain per generation through early selection. Genomic selection is expected to be particularly valuable for traits that are costly to phenotype and expressed late in the life cycle of long-lived species. Alternative approaches to genomic selection prediction models may perform differently for traits with distinct genetic properties. Here the performance of four different original methods of genomic selection that differ with respect to assumptions regarding distribution of marker effects, including (i) ridge regression–best linear unbiased prediction (RR–BLUP), (ii) Bayes A, (iii) Bayes Cπ, and (iv) Bayesian LASSO are presented. In addition, a modified RR–BLUP (RR–BLUP B) that utilizes a selected subset of markers was evaluated. The accuracy of these methods was compared across 17 traits with distinct heritabilities and genetic architectures, including growth, development, and disease-resistance properties, measured in a Pinus taeda (loblolly pine) training population of 951 individuals genotyped with 4853 SNPs. The predictive ability of the methods was evaluated using a 10-fold, cross-validation approach, and differed only marginally for most method/trait combinations. Interestingly, for fusiform rust disease-resistance traits, Bayes Cπ, Bayes A, and RR–BLUB B had higher predictive ability than RR–BLUP and Bayesian LASSO. Fusiform rust is controlled by few genes of large effect. A limitation of RR–BLUP is the assumption of equal contribution of all markers to the observed variation. However, RR-BLUP B performed equally well as the Bayesian approaches.The genotypic and phenotypic data used in this study are publically available for comparative analysis of genomic selection prediction models

Crescimento econômico e a moderna crise ambiental: uma análise crítica

We discuss in this essay the importance of overcoming the scientific and epistemological reductionism to achieve a critical understanding of the origins of the environmental crisis experienced by humanity in this new millennium. Through a historical review, we trace the transformation of economic models, their impact on the environment, as well the effectiveness and legitimacy of the main technical and political process historically proposed to overcome the environmental crisis. Given the insignificant results obtained by this technicist way of understanding the environmental issues, we believe that the hegemony of the paradigm of development as economic growth is an important reason for the current social and environmental problems. The neglect of socio-economic dimension in the environment discussions has led to a failure of conservation policies by those who actually seek alternative paths to socio-ecological sustainability of the planet.Key words: conservation of biodiversity, economy, economic growth.Discutimos neste ensaio a importância da superação dos reducionismos científicos e epistemológicos para se alcançar uma compreensão crítica das origens da crise ambiental experimentada pela humanidade neste início de milênio. Por meio de um resgate histórico, traçamos as transformações dos modelos econômicos, seus impactos ao meio ambiente, assim como a eficácia e a legitimidade das principais vias técnico-políticas propostas para superar a crise ambiental. Tendo em conta os irrisórios resultados alcançados pela via tecnicista de entendimento da questão ambiental, acreditamos ser a hegemonia do paradigma do desenvolvimento por meio do crescimento econômico uma importante razão dos atuais problemas socioambientais. O negligenciamento da dimensão socioeconômica nas discussões ambientais tem conduzido a um fracasso das políticas de conservação por parte daqueles que, de fato buscam caminhos alternativos para sustentabilidade socioecológica do planeta.Palavras-chave: conservação da biodiversidade, economia, crescimento econômico

Prognostic value of MGMT promoter methylation in glioblastoma patients treated with temozolomide-based chemoradiation : a Portuguese multicentre study

Glioblastoma (GBM) is the most common and aggressive primary brain tumor. The identification of novel molecular prognostic markers of GBM has recently been an area of great interest in neuro-oncology. The methylation status of the MGMT gene promoter is currently a promising molecular prognostic marker, but some controversial data have precluded its clinical use. We analyzed MGMT methylation by methylation-specific PCR in 90 GBM patients from four Portuguese hospitals, uniformly treated with radiotherapy combined with concomitant and adjuvant temozolomide (Stupp protocol). The Kaplan-Meier method was used to construct survival curves, and the log-rank test and a Cox-regression model were used to analyze patient survival. The methylation status of MGMT was successfully determined in 89% (80/90) of the tumors. The frequency of tumoral MGMT promoter methylation was 47.5%. The median overall survivals (OSs) were 16 months (95% CI 12.2-19.8) and 13 months (95% CI 13.3-18.7) for patients whose tumors had a methylated or unmethylated MGMT, respectively. Univariate and multivariate analyses did not show any statistically significant association between MGMT methylation status and patient OS (P=0.583 by the log-rank test; P=0.617 by the Cox-regression test) or progression-free survival (P=0.775 by the log-rank test; P=0.691 by the Cox-regression test). None of the patient clinical features were significantly correlated with survival. This is the first study to report the frequency of MGMT methylation among Portuguese GBM patients. Our data did not show statistically significant associations between MGMT promoter methylation and the outcome of GBM patients treated with temozolomide. Additional robust prospective studies are warranted to clarify whether the MGMT status should be used in clinical decisions.This project was sponsored, in part, by Schering-Ploug Farma (Portugal). B.M.C. and O.M. are recipients of fellowships from the Portuguese Science and Technology Foundation (SFRH/BPD/33612/2009 and SFRH/BD/36463/ 2007). The funding institutions had no role in the study design, data collection and analysis, interpretation of the results, the preparation of the manuscript, or the decision to submit the manuscript for publication

IL-10 Overexpression After BCG Vaccination Does Not Impair Control of Mycobacterium tuberculosis Infection

Control of tuberculosis depends on the rapid expression of protective CD4+ T-cell responses in the Mycobacterium tuberculosis (Mtb)-infected lungs. We have recently shown that the immunomodulatory cytokine IL-10 acts intrinsically in CD4+ T cells and impairs their parenchymal migratory capacity, thereby preventing control of Mtb infection. Herein, we show that IL-10 overexpression does not impact the protection conferred by the established memory CD4+ T-cell response, as BCG-vaccinated mice overexpressing IL-10 only during Mtb infection display an accelerated, BCG-induced, Ag85b-specific CD4+ T-cell response and control Mtb infection. However, IL-10 inhibits the migration of recently activated ESAT-6-specific CD4+ T cells into the lung parenchyma and impairs the development of ectopic lymphoid structures associated with reduced expression of the chemokine receptors CXCR5 and CCR7. Together, our data support a role for BCG vaccination in preventing the immunosuppressive effects of IL-10 in the fast progression of Mtb infection and may provide valuable insights on the mechanisms contributing to the variable efficacy of BCG vaccination

Succinate causes pathological cardiomyocyte hypertrophy through GPR91 activation

Background\ud Succinate is an intermediate of the citric acid cycle as well as an extracellular circulating molecule, whose receptor, G protein-coupled receptor-91 (GPR91), was recently identified and characterized in several tissues, including heart. Because some pathological conditions such as ischemia increase succinate blood levels, we investigated the role of this metabolite during a heart ischemic event, using human and rodent models.\ud \ud \ud Results\ud We found that succinate causes cardiac hypertrophy in a GPR91 dependent manner. GPR91 activation triggers the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), the expression of calcium/calmodulin dependent protein kinase IIδ (CaMKIIδ) and the translocation of histone deacetylase 5 (HDAC5) into the cytoplasm, which are hypertrophic-signaling events. Furthermore, we found that serum levels of succinate are increased in patients with cardiac hypertrophy associated with acute and chronic ischemic diseases.\ud \ud \ud Conclusions\ud These results show for the first time that succinate plays an important role in cardiomyocyte hypertrophy through GPR91 activation, and extend our understanding of how ischemia can induce hypertrophic cardiomyopathy.CAPESFAPEMIG (Pronex)INCT- Carbon NanotubesCNPqHHM