Exploring the knowledge contained in neuroimages: Statistical discriminant analysis and automatic segmentation of the most significant changes

Objective: The aim of this article is to propose an integrated framework for extracting and describing patterns of disorders from medical images using a combination of linear discriminant analysis and active contour models. Methods: A multivariate statistical methodology was first used to identify the most discriminating hyperplane separating two groups of images (from healthy controls and patients with schizophrenia) contained in the input data. After this, the present work makes explicit the differences found by the multivariate statistical method by subtracting the discriminant models of controls and patients, weighted by the pooled variance between the two groups. A variational level-set technique was used to segment clusters of these differences. We obtain a label of each anatomical change using the Talairach atlas. Results: In this work all the data was analysed simultaneously rather than assuming a priori regions of interest. As a consequence of this, by using active contour models, we were able to obtain regions of interest that were emergent from the data. The results were evaluated using, as gold standard, well-known facts about the neuroanatomical changes related to schizophrenia. Most of the items in the gold standard was covered in our result set. Conclusions: We argue that such investigation provides a suitable framework for characterising the high complexity of magnetic resonance images in schizophrenia as the results obtained indicate a high sensitivity rate with respect to the gold standard. (C) 2010 Elsevier B.V. All rights reserved.

Inspeção sanitária em creches: uma proposta de roteiro de inspeção

O trabalho apresenta um projeto de intervenção na realidade concreta das ações de Vigilância Sanitária, através da proposição de um roteiro para inspeção destinado a creches. Os objetivos específicos foram identificar os fundamentos jurídicos, técnico-científicos e sanitários que possam nortear a prática de inspeções sanitárias em creches; elaborar uma proposta de roteiro que permita um processo de análise mais explícito, objetivo e homogêneo e discutir a contribuição do instrumento proposto para a atividade de Vigilância Sanitária, com base na literatura científica pesquisada. Para a realização do trabalho foi feita uma revisão fundamentada em textos didáticos e normativos das áreas de educação e saúde, legislação sobre Vigilância Sanitária e Educação Infantil, outros roteiros já existentes e artigos da literatura científica sobre agravos à saúde em crianças que frequentam creches. O trabalho focaliza o conteúdo da legislação específica vigente e sua aplicabilidade na prática da inspeção sanitária em creches e baseia-se na Portaria - MS n. 321 de 26.05.1988. Este estudo apresenta um instrumento para avaliar a qualidade do atendimento nas creches sob o aspecto da promoção da saúde e sugere estudos posteriores de validação para o contexto, com a possível inclusão de um sistema de classificação para os padrões de conformidade, por meio de uma metodologia estatística

Response surface methodology as an approach to determine optimal activities of lipase entrapped in sol-gel matrix using different vegetable oils

The conditions for maximization of the enzymatic activity of lipase entrapped in sol-gel matrix were determined for different vegetable oils using an experimental design. The effects of pH, temperature, and biocatalyst loading on lipase activity were verified using a central composite experimental design leading to a set of 13 assays and the surface response analysis. For canola oil and entrapped lipase, statistical analyses showed significant effects for pH and temperature and also the interactions between pH and temperature and temperature and biocatalyst loading. For the olive oil and entrapped lipase, it was verified that the pH was the only variable statistically significant. This study demonstrated that response surface analysis is a methodology appropriate for the maximization of the percentage of hydrolysis, as a function of pH, temperature, and lipase loading.

Thermodynamic and statistical analysis of soybean oil extraction process using renewable solvent

The main goal of this work was to evaluate thermodynamic parameters of the soybean oil extraction process using ethanol as solvent. The experimental treatments were as follows: aqueous solvents with water contents varying from 0 to 13% (mass basis) and extraction temperature varying from 50 to 100 degrees C. The distribution coefficients of oil at equilibrium have been used to calculate enthalpy, entropy and free energy changes. The results indicate that oil extraction process with ethanol is feasible and spontaneous, mainly under higher temperature. Also, the influence of water level in the solvent and temperature were analysed using the response surface methodology (RSM). It can be noted that the extraction yield was highly affected by both independent variables. A joint analysis of thermodynamic and RSM indicates the optimal level of solvent hydration and temperature to perform the extraction process.

A statistical evaluation of the field emission for copper oxide nanostructures

A statistical data analysis methodology was developed to evaluate the field emission properties of many samples of copper oxide nanostructured field emitters. This analysis was largely done in terms of Seppen-Katamuki (SK) charts, field strength and emission current. Some physical and mathematical models were derived to describe the effect of small electric field perturbations in the Fowler-Nordheim (F-N) equation, and then to explain the trend of the data represented in the SK charts. The field enhancement factor and the emission area parameters showed to be very sensitive to variations in the electric field for most of the samples. We have found that the anode-cathode distance is critical in the field emission characterization of samples having a non-rigid nanostructure. (C) 2007 Elsevier B.V. All rights reserved.

Optimization of the ultrasound-assisted synthesis of allyl 1-naphthyl ether using response surface methodology

Allyl 1-naphthyl ethers are useful compounds for different purposes, but reported methods to synthesize them require long reaction times. In this work, we have obtained allyl 1-naphthyl ether in good yield using ultrasonic-assisted methodology in a 1-h reaction. A central composite design was used to obtain a statistical model and a response surface (p < 0.05; R(2) = 0.970; R(adj)(2) = 0.949; R(pred)(2) = 0.818) that can predict the optimal conditions to maximize the yield, validated experimentally. (C) 2010 Elsevier B.V. All rights reserved.

Sequential injection analysis (SIA) and response surface methodology: A versatile small volume approach for optimization of photo-Fenton processes

Optimization of photo-Fenton degradation of copper phthalocyanine blue was achieved by response surface methodology (RSM) constructed with the aid of a sequential injection analysis (SIA) system coupled to a homemade photo-reactor. Highest degradation percentage was obtained at the following conditions [H(2)O(2)]/[phthalocyanine] = 7, [H(2)O(2)]/[FeSO(4)] = 10, pH = 2.5, and stopped flow time in the photo reactor = 30 s. The SIA system was designed to prepare a monosegment containing the reagents and sample, to pump it toward the photo-reactor for the specified time and send the products to a flow-through spectrophotometer for monitoring the color reduction of the dye. Changes in parameters such as reagent molar ratios. residence time and pH were made by modifications in the software commanding the SI system, without the need for physical reconfiguration of reagents around the selection valve. The proposed procedure and system fed the statistical program with degradation data for fast construction of response surface plots. After optimization, 97% of the dye was degraded. (C) 2009 Elsevier B.V. All rights reserved.

Applying sequential injection analysis (SIA) and response surface methodology for optimization of Fenton-based processes

This work presents the use of sequential injection analysis (SIA) and the response surface methodology as a tool for optimization of Fenton-based processes. Alizarin red S dye (C.I. 58005) was used as a model compound for the anthraquinones family. whose pigments have a large use in coatings industry. The following factors were considered: [H(2)O(2)]:[Alizarin] and [H(2)O(2)]:[FeSO(4)] ratios and pH. The SIA system was designed to add reagents to the reactor and to perform on-line sampling of the reaction medium, sending the samples to a flow-through spectrophotometer for monitoring the color reduction of the dye. The proposed system fed the statistical program with degradation data for fast construction of response surface plots. After optimization, 99.7% of the dye was degraded and the TOC content was reduced to 35% of the original value. Low reagents consumption and high sampling throughput were the remarkable features of the SIA system. (C) 2008 Published by Elsevier B.V.

Development of a spectrophotometric Sequential Injection Analysis (SIA) procedure for determination of ammonium: A Response Surface Methodology (RSM) approach

This paper describes the optimization and use of a Sequential Injection Analysis (SIA) procedure for ammonium determination in waters. Response Surface Methodology (RSM) was used as a tool for optimization of a procedure based on the modified Berthelot reaction. The SIA system was designed to (i) prepare the reaction media by injecting an air-segmented zone containing the reagents in a mixing chamber, (ii) to aspirate the mixture back to the holding coil after homogenization, (iii) drive it to a thermostated reaction coil, where the flow is stopped for a previously established time, and (iv) to pump the mixture toward the detector flow cell for the spectrophotometric measurements. Using a 100 mu mol L(-1) ammonium solution, the following factors were considered for optimization: reaction temperature (25 - 45 degrees C), reaction time (30 - 90 s), hypochlorite concentration (20 - 40 mmol L(-1)) nitroprusside concentration (10 - 40 mmol L(-1)) and salicylate concentration (0.1 - 0.3 mol L(-1)). The proposed system fed the statistical program with absorbance data for fast construction of response surface plots. After optimization of the method, figures of merit were evaluated, as well as the ammonium concentration in some water samples. No evidence of statistical difference was observed in the results obtained by the proposed method in comparison to those obtained by a reference method based on the phenol reaction. (C) 2010 Elsevier B.V. All rights reserved.

O conhecimento de professores de 1ª a 4ª série quanto aos distúrbios da leitura e escrita

OBJETIVO: investigar o conhecimento dos professores de 1ª a 4ª série quanto ao distúrbio da leitura e escrita, pesquisando quais dificuldades referentes a esse distúrbio, foram apresentadas por estes professores. MÉTODOS: esses dados foram obtidos, por meio de um questionário informativo de 10 questões, aplicados a 50 professores de 1ª a 4ª série, da cidade de Bauru. Os questionários foram analisados e tabulados, e receberam tratamento estatístico pertinente. RESULTADOS: os resultados obtidos revelaram que os professores possuem um conhecimento superficial a respeito do distúrbio da leitura e escrita, sendo que muitos adquiriram tal conhecimento fora do ambiente de graduação. Verificou-se também que os professores apesar de encaminharem seus alunos ao fonoaudiólogo, possuem visão limitada quanto à atuação deste profissional. O distúrbio da leitura e escrita foi considerado como um problema próprio da criança, sendo pouco reconhecido como uma falha que também pode ser da escola ou da metodologia de ensino. CONCLUSÃO: os professores logram um saber pouco fundamentado a respeito do distúrbio da leitura e escrita; sendo que, as dificuldades giraram em torno: da identificação real do problema; de quais manifestações caracterizam esse problema; e de como intervir e prevenir.

Neural networks and statistical analysis for classification of corneal videokeratography maps based on Zernike coefficients: a quantitative comparison

PURPOSE: The main goal of this study was to develop and compare two different techniques for classification of specific types of corneal shapes when Zernike coefficients are used as inputs. A feed-forward artificial Neural Network (NN) and discriminant analysis (DA) techniques were used. METHODS: The inputs both for the NN and DA were the first 15 standard Zernike coefficients for 80 previously classified corneal elevation data files from an Eyesys System 2000 Videokeratograph (VK), installed at the Departamento de Oftalmologia of the Escola Paulista de Medicina, São Paulo. The NN had 5 output neurons which were associated with 5 typical corneal shapes: keratoconus, with-the-rule astigmatism, against-the-rule astigmatism, "regular" or "normal" shape and post-PRK. RESULTS: The NN and DA responses were statistically analyzed in terms of precision ([true positive+true negative]/total number of cases). Mean overall results for all cases for the NN and DA techniques were, respectively, 94% and 84.8%. CONCLUSION: Although we used a relatively small database, results obtained in the present study indicate that Zernike polynomials as descriptors of corneal shape may be a reliable parameter as input data for diagnostic automation of VK maps, using either NN or DA.

Methodology of a nationwide cross-sectional survey of prevalence and epidemiological patterns of hepatitis A, B and C infection in Brazil

Um inquérito de base populacional foi conduzido na população urbana de todas as capitais e do Distrito Federal no Brasil para fornecer informações sobre a prevalência de hepatites virais e fatores de risco, entre 2005 e 2009. Este artigo descreve o delineamento e a metodologia do estudo que envolveu a população com idade entre 5 e 19 anos para hepatite A e 10 a 69 anos para hepatite B e C. As entrevistas e amostras de sangue foram obtidas através de visitas domiciliares e a amostra selecionada a partir de uma amostragem estratificada em múltiplos estágios (por conglomerado) com igual probabilidade para cada domínio de estudo (região e faixa etária). Nacionalmente, 19.280 residências e ~31.000 indivíduos foram selecionados. O tamanho da amostra foi suficiente para detectar uma prevalência em torno de 0,1% e para avaliar os fatores de risco por região. A metodologia apresentou-se viável para distinguir entre diferentes padrões epidemiológicos da hepatite A, B e C. Estes dados serão de valia para a avaliação das políticas de vacinação e para o desenho de estratégias de controle.

Evaluation of follicular lymphoid depletion in the Bursa of Fabricius: an alternative methodology using digital image analysis and artificial neural networks

Fifty Bursa of Fabricius (BF) were examined by conventional optical microscopy and digital images were acquired and processed using Matlab® 6.5 software. The Artificial Neuronal Network (ANN) was generated using Neuroshell® Classifier software and the optical and digital data were compared. The ANN was able to make a comparable classification of digital and optical scores. The use of ANN was able to classify correctly the majority of the follicles, reaching sensibility and specificity of 89% and 96%, respectively. When the follicles were scored and grouped in a binary fashion the sensibility increased to 90% and obtained the maximum value for the specificity of 92%. These results demonstrate that the use of digital image analysis and ANN is a useful tool for the pathological classification of the BF lymphoid depletion. In addition it provides objective results that allow measuring the dimension of the error in the diagnosis and classification therefore making comparison between databases feasible.

Mortes maternas e mortes por causas maternas

Ao mensurar-se mortalidade materna, é necessário distinguir ' mortes por causas maternas' e 'mortes maternas' Para a Organização Mundial da Saúde-OMS-,mortes maternas são as que ocorrem na gestação, no parto e até 42 dias após o parto; e mortes por causas maternas englobam as causas classificadas no Capítulo XV da Classificação Estatística Internacional de Doenças e Problemas Relacionados à Saúde, Décima Revisão (CID-10), incluindo as ocorridas quando passados 42 dias do parto. Apresentam-se resultados da investigação de mortes femininas em idade fértil-10 a 49 anos- nas capitais de Estados e no Distrito Federal do Brasil, em 2002. Adotou-se a metodologia RAMOS, comparando-se as causas básicas das declarações de óbito originais com as das declarações preenchidas após o resgate de informações, obtidas em entrevistas domiciliares e prontuários. Entre as mortes por causas maternas originais, 15,9 por cento não eram mortes maternas, de acordo com a definição da OMS. Houve, concomitantemente, subenumeração de mortes maternas. Sugestões são feitas para melhorar o preenchimento das declarações de óbito e inclusão de novas categorias na CID-10, visando melhorar a informação das causas maternas

Treinamento de escolares de 7 a 10 anos para o preenchimento de um Diário Alimentar

INTRODUÇÃO: É reconhecida a efetividade de um treinamento para melhorar a qualidade no relato do consumo alimentar em adultos, porém poucos estudos avaliam esta efetividade em crianças. OBJETIVO: Investigar o efeito da realização de um treinamento para o desenvolvimento de habilidades para um correto preenchimento de um Diário Alimentar, por escolares de 7 a 10 anos. METODOLOGIA: O estudo foi conduzido em uma escola pública da cidade de São Paulo e envolveu a realização de 3 sessões de treinamento de 30 minutos cada, direcionadas a 40 escolares de ambos os sexos. Para verificação do efeito do treinamento, 3 examinadores avaliaram o preenchimento dos dados antes e após o mesmo. Foram atribuídos escores de 0 a 5 para aspectos relativos à identificação, detalhamento e quantificação do alimento consumido, e calculado o escore médio a partir dos escores de cada examinador para cada aspecto. Utilizou-se o teste de Wilcoxon para comparação de amostras dependentes. RESULTADOS: Foi constatada evidência estatística de diferença entre os escores antes e após o treinamento para os três aspectos: identificação (p < 0,001), detalhamento (p = 0,003) e quantificação do alimento (p < 0,001), sendo grande parte dos valores após o treinamento maiores que os iniciais. CONCLUSÃO: É possível aumentar a habilidade de escolares de 7 a 10 anos no preenchimento de um Diário Alimentar a partir da realização de um treinamento nos moldes apresentados neste artigo