Influence of physical training on bone mineral density in healthy young adults: a systematic review

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Non-traditional students in higher education: barriers to learning and professional insertion

This article emerges from two research projects focused on non-traditional students in higher education. Our objectives aims to understand the barriers of learning and academic success, considering the perspectives of the several social actors in the academia; and to understand the barriers of the same students had in their transition to the work environment. The results show that a set of situational and institutional factors work as obstacles to these students. The results also show that age is a determinant factor regarding hiring and that the characteristics of the labour market today make hard the professional insertion of non-traditional undergraduates

Low-complexity DCD-based sparse recovery algorithms

Sparse recovery techniques find applications in many areas. Real-time implementation of such techniques has been recently an important area for research. In this paper, we propose computationally efficient techniques based on dichotomous coordinate descent (DCD) iterations for recovery of sparse complex-valued signals. We first consider $\ell_2 \ell_1$ optimization that can incorporate \emph{a priori} information on the solution in the form of a weight vector. We propose a DCD-based algorithm for $\ell_2 \ell_1$ optimization with a fixed $\ell_1$-regularization, and then efficiently incorporate it in reweighting iterations using a \emph{warm start} at each iteration. We then exploit homotopy by sampling the regularization parameter and arrive at an algorithm that, in each homotopy iteration, performs the $\ell_2 \ell_1$ optimization on the current support with a fixed regularization parameter and then updates the support by adding/removing elements. We propose efficient rules for adding and removing the elements. The performance of the homotopy algorithm is further improved with the reweighting. We then propose an algorithm for $\ell_2 \ell_0$ optimization that exploits homotopy for the $\ell_0$ regularization; it alternates between the least-squares (LS) optimization on the support and the support update, for which we also propose an efficient rule. The algorithm complexity is reduced when DCD iterations with a \emph{warm start} are used for the LS optimization, and, as most of the DCD operations are additions and bit-shifts, it is especially suited to real time implementation. The proposed algorithms are investigated in channel estimation scenarios and compared with known sparse recovery techniques such as the matching pursuit (MP) and YALL1 algorithms. The numerical examples show that the proposed techniques achieve a mean-squared error smaller than that of the YALL1 algorithm and complexity comparable to that of the MP algorithm

MAPEAMENTO TECNOLÓGICO DE REAÇÕES DO COMPOSTO TIOUREAS COM MOLÉCULAS DE AMIDA NA OBTENÇÃO DE PRODUTOS FARMACÊUTICOS DE USO COSMÉTICO E TERAPÊUTICO

As reações enzimáticas de proteínas inibidoras vêm se tornando importante fonte de estudos contribuindo para o avanço biotecnológico levando a descobertas de novas estruturas moleculares principalmente as derivadas da amida. A pesquisa biotecnológica aqui proposta utiliza o metabolismo de microrganismos como fungos e bactérias como principal mecanismo biotecnológico associado a sedimento manguezal exudado de petróleo e co-produtos glicerina e residual de mamona. Neste sentido, foi realizado um estudo de prospecção tecnológica no banco de dados Web of Science – Espacenet, por códigos indexados na Classificação Internacional De Patentes (CIP), que mostraram boas perspectivas em relação ao uso de microorganismos para a produção de moléculas de amida envolvendo reações enzimáticas inibidoras de uso na indústria farmacêutica para produção de produtos cosméticos e medicamentos

Factors controlling spatio-temporal variation in carbon dioxide efflux from surface litter, roots, and soil organic matter at four rain forest sites in the eastern Amazon

[1] This study explored biotic and abiotic causes for spatio-temporal variation in soil respiration from surface litter, roots, and soil organic matter over one year at four rain forest sites with different vegetation structures and soil types in the eastern Amazon, Brazil. Estimated mean annual soil respiration varied between 13-17 t C ha(-1) yr(-1), which was partitioned into 0-2 t C ha(-1) yr(-1) from litter, 6-9 t C ha(-1) yr(-1) from roots, and 5-6 t C ha(-1) yr(-1) from soil organic matter. Litter contribution showed no clear seasonal change, though experimental precipitation exclusion over a one-hectare area was associated with a ten-fold reduction in litter respiration relative to unmodified sites. The estimated mean contribution of soil organic matter respiration fell from 49% during the wet season to 32% in the dry season, while root respiration contribution increased from 42% in the wet season to 61% during the dry season. Spatial variation in respiration from soil, litter, roots, and soil organic matter was not explained by volumetric soil moisture or temperature. Instead, spatial heterogeneity in litter and root mass accounted for 44% of observed spatial variation in soil respiration (p < 0.001). In particular, variation in litter respiration per unit mass and root mass accounted for much of the observed variation in respiration from litter and roots, respectively, and hence total soil respiration. This information about patterns of, and underlying controls on, respiration from different soil components should assist attempts to accurately model soil carbon dioxide fluxes over space and time

ACTIVITY ANTI-C. TROPICALIS AND EFFECTS OF THE COMBINATION OF (S)-(-)-CITRONELLAL WITH FOUR ANTIFUNGAL APPLIED IN VULVOVAGINAL CANDIDIASIS

Objective: Assess the antifungal potential of the enantiomer (S)-(-)-citronellal [(S)-(-)-CT] isolated and associated to amphotericin B, fluconazole, itraconazole and miconazole against C. tropicalis from vulvovaginal secretions.Methods: The enantiomer was solubilized in Tween 80 and DMSO. Posteriorly diluted in sterile distilled water up to the concentration of 2048 µg/ml. The MIC of the product was determined by microdilution in RPMI-1640 obtaining dilutions of 1024-4 µg/ml. The MFC was determined by the SDA depletion technique from aliquots of 1 µl of the MIC, MIC × 2 and MIC × 4.Results: The antifungal susceptibility testing and the interfering effects of the association of the enantiomer with the standard drugs were determined by disk-diffusion in SDA. The MIC of (S)-(-)-CT was 64 µg/ml and the MFC 128 µg/ml. A high resistance of the strands C. tropicalis to amphotericin B, itraconazole and miconazole were observed. The combination test of the enantiomer with the amphotericin B, as well as with the itraconazole resulted in synergism 2 (66.6%) of the yeasts and in association with the fluconazole 1 (33.3%) and miconazole 3 (100%) of synergic effect.Conclusion: The (S)-(-)-CT alone is fungicide for the 3 fungal strains and in association with the four antifungals increased the inhibition zones, increasing the sensitivity

Simulação do processo de produção de etanol de arroz BRS AG usando Aspen Plus.

A simulação computacional é uma ferramenta bastante utilizada na resolução de equações que descrevem sistemas na Engenharia Química, bem como na otimização e acompanhamento de processos. O software Aspen Plus® é um simulador da AspenTech, líder de simulação de processos da indústria química, presente há mais de 35 anos no mercado. Pode ser empregado com o intuito de se obter melhora nos rendimentos e na produtividade, bem como redução de custos operacionais. Esse software é abrangente para a indústria química, podendo ser usado para modelagem em processos em batelada e contínuos, desde a inovação até as etapas de operação. Outra finalidade para esse simulador é a análise de segurança e de design de equipamentos. O presente trabalho tem como objetivo utilizar o simulador Aspen Plus® para modelagem e simulação do processo de produção de etanol, utilizando como matéria&#8209;prima a cultivar de arroz BRS AG. Com a simulação avaliou&#8209;se o fluxo mássico e as frações mássicas das correntes de entrada e saída de cada etapa. Para isso, os parâmetros adotados para a simulação foram as quantidades e os rendimentos obtidos em um estudo preliminar de fermentação dessa cultivar de arroz feito em escala de bancada. Com a modelagem e simulação proposta, é possível avaliar e propor uma otimização do processo, visando a produção em larga escala