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Da Silva M.G.,University Regional Of Gurupi | Camara J.T.,State University of Maranhao | Vinaud M.C.,Federal University of Goais | De Castro A.M.,Federal University of Goais
Revista da Sociedade Brasileira de Medicina Tropical | Year: 2014

Introduction: Knowledge of the prevalence and risk factors for Toxoplasma gondii dissemination among pregnant women is relevant because the parasite can be spread from mother to infant. The objective of this study was to assess the epidemiology and risk factors of toxoplasmosis in pregnant women from Gurupi, State of Tocantins, Brazil, from February 2012 to June 2013. Methods: The study population included 487 pregnant women. Sociodemographic, dietary and cultural data were collected using a standardized and validated form. Peripheral blood was collected for serologic testing using the ELISA test (IgM/IgG antibodies). The data were analyzed by comparing seropositivity with risk factors using crude and adjusted odds ratios. Results: The prevalence rate for IgG and IgM antibodies was 68.7% and 5.7%, respectively. Sociodemographic characteristics associated with toxoplasmosis risk included the following: education level ≤ 8 years (OR: 6.612; CI: 1.450-30.144), age ≥ 30 years (OR: 5.273; CI: 1.166-23.844), working outside the home (OR: 1.604; CI: 1.015-2.536), and family income of two minimum wages or lower (OR: 2.700; CI: 1.891-8.182). Regarding dietary habits, there was a signifi cant association of seropositivity with meat intake (OR: 1.78; CI: 1.149-4.080), cutting vegetables without washing the cutting board beforehand (OR: 2.051; CI: 1.165- 3.614), frequent intake of vegetables (OR: 2.051; CI: 1.368-3.006) and in natura milk intake (OR: 2.422; CI: 1.014-5.785). Conclusions: The high prevalence rates of toxoplasmosis in Gurupi are related to age, raw meat and in natura milk intake, as well as education level, working outside the home, and poor hygienic habits during meal preparation. © 2014 Sociedade Brasileira de Medicina Tropical. All rights reserved. Source

Neto J.V.F.,Federal University of Maranhao | Rego P.H.M.,State University of Maranhao
International Journal of Innovative Computing, Information and Control | Year: 2014

A novel approach for online design of optimal control systems based on QR- tuning, state and action-dependent heuristic dynamic programming, and approximate-LS solutions of the Hamilton-Jacobi-Bellman (HJB) equation is the main concern of this paper. The QR-tuning for optimal control systems takes into account heuristic variations in the weighting matrices Q and R of the discrete linear quadratic regulator (DLQR) performance index. These heuristics are guided by an approximate relation of the matrices Q and R. Specifically, the proposed approximate solutions are based on the least-squares approach, and applications are performed on the DLQR problem. The parameterizations of the Bellman equation, utility function and dynamic system assemble a framework for the solution of the DLQR problem. The approximate solutions of the HJB-Riccati equation are given by a vectorization of a quadratic form which is the value function of DLQR. Such formulation allows a least-squares (LS) solution of the discrete algebraic Riccati equation (DARE). The LS formulation of the problem is based on a transformation of the state space variables to assemble the regressor vectors, and observations are based on the utility function and DARE solutions. The computational experiments are provided to evaluate the efficiency of QR-tuning heuristics to map the stable Z-plane. © ICIC International 2014. Source

Rousseau G.X.,State University of Maranhao | Deheuvels O.,CIRAD - Agricultural Research for Development | Deheuvels O.,Tropical Agriculture Research and Higher Education Center | Rodriguez Arias I.,Asociacion de Desarrollo Integral de la Reserva Indigena Bribri de Talamanca | Somarriba E.,Tropical Agriculture Research and Higher Education Center
Ecological Indicators | Year: 2012

Soil quality or health is a fuzzy concept that has been vigorously criticized due to the extreme variability of soil and the difficulty of linking soil indicators to soil functions and sustainability. In most soil quality studies some obvious factors or typologies are used as a basis to select the "best indicators" of soil quality, i.e. those that best explain the differences among the plots under study. This is not the case for a variety of natural or agro-ecosystems including the Talamanca cacao-based agroforestry systems (AFS), which present neither a pre-established typology nor a clear framework to evaluate their soil quality. This situation required a selection of indicators based on the literature that was oriented by the non-equilibrium thermodynamic theory. A framework was elaborated through full and minimum indicator sets of baseline soil physical and chemical indicators, along with macrofauna groups. A minimum set of four well-accepted abiotic soil quality indicators (bulk density, sum of bases, pH and carbon) was able to separate cacao AFS plots and forests into five distinct clusters along a low-to-high "soil quality" gradient. The AFS rated as "good" soil quality did not differ from the forest. Abundances of selected macrofauna groups were well correlated with these indicators and helped elucidate the soil quality clusters identified. In particular, high predator abundance indicated proper energy flow and confirmed the high abiotic soil quality, thus confirming the potential of macrofauna groups as apt soil quality indicators. However, these indicators need to be tailored to local conditions. Consequentially, cacao-based AFS in Talamanca are able to conserve soil and provide a high level of soil-related ecological services. Considering the soil an open system where the non-equilibrium thermodynamic theory applies successfully guided indicator selection and could help to reformulate the soil quality definition. © 2012 Elsevier Ltd. All rights reserved. Source

Santana E.,Federal University of Maranhao | Principe J.C.,University of Florida | Santana E.E.,State University of Maranhao | Freire R.C.S.,Federal University of Campina Grande | Barros A.K.,National Agency of Petroleum
IEEE Transactions on Signal Processing | Year: 2010

This work derives and evaluates a method for Blind Source Extraction (BSE) in a reproducing kernel Hilbert space (RKHS) framework. The a priori information about the autocorrelation function of the signal under study is translated in a linear transformation of the Gram matrix of the transformed data in Hilbert space. Our method proved to be more robust than methods presented in the literature of BSE with respect to ambiguities in the available a priori information of the signal to be extracted. The approach here introduced can also be seen as a generalization of Kernel principal component analysis (KPCA) to analyze autocorrelation matrices at specific time lags. © 2010 IEEE. Source

Rios M.A.M.,Institute Ecologia | Grossi P.C.,State University of Maranhao
Entomotropica | Year: 2015

The genus Philoscaptus Brèthes, 1919, is revised and found to be monotypic, including P. bonariensis (Burmeister) a species found mainly in open areas along the Paraná River basin, in Brazil, Uruguay, Argentina and Paraguay (new country record). The new genus Saccharoscaptus is described for P. laminifer Dechambre, differentiated by mandibles with one weak rounded apical tooth, apex of clypeus with no denticles, frons excavate, male with blade like process on clypeus and small pronotal tubercles. A key for males of the Neotropical Pentodontini genera is given and the current status of Ligyrus Burmeister and Tomarus Erichson is discussed and a checklist with the known species included in each genus is also provided. © 2015, Sociedad Venezolana de Entomología. Source

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