Robust fault diagnosis in power distribution systems based on fuzzy ARTMAP neural network-aided evidence theory

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Design of a Takagi-Sugeno Fuzzy Regulator for a Set of Operation Points

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Algoritmos de agrupamento aplicados a dados de expressão gênica de câncer: um estudo comparativo

The use of clustering methods for the discovery of cancer subtypes has drawn a great deal of attention in the scientific community. While bioinformaticians have proposed new clustering methods that take advantage of characteristics of the gene expression data, the medical community has a preference for using classic clustering methods. There have been no studies thus far performing a large-scale evaluation of different clustering methods in this context. This work presents the first large-scale analysis of seven different clustering methods and four proximity measures for the analysis of 35 cancer gene expression data sets. Results reveal that the finite mixture of Gaussians, followed closely by k-means, exhibited the best performance in terms of recovering the true structure of the data sets. These methods also exhibited, on average, the smallest difference between the actual number of classes in the data sets and the best number of clusters as indicated by our validation criteria. Furthermore, hierarchical methods, which have been widely used by the medical community, exhibited a poorer recovery performance than that of the other methods evaluated. Moreover, as a stable basis for the assessment and comparison of different clustering methods for cancer gene expression data, this study provides a common group of data sets (benchmark data sets) to be shared among researchers and used for comparisons with new methods

Segmentação fuzzy de imagens e vídeos

Image segmentation is the process of subdiving an image into constituent regions or objects that have similar features. In video segmentation, more than subdividing the frames in object that have similar features, there is a consistency requirement among segmentations of successive frames of the video. Fuzzy segmentation is a region growing technique that assigns to each element in an image (which may have been corrupted by noise and/or shading) a grade of membership between 0 and 1 to an object. In this work we present an application that uses a fuzzy segmentation algorithm to identify and select particles in micrographs and an extension of the algorithm to perform video segmentation. Here, we treat a video shot is treated as a three-dimensional volume with different z slices being occupied by different frames of the video shot. The volume is interactively segmented based on selected seed elements, that will determine the affinity functions based on their motion and color properties. The color information can be extracted from a specific color space or from three channels of a set of color models that are selected based on the correlation of the information from all channels. The motion information is provided into the form of dense optical flows maps. Finally, segmentation of real and synthetic videos and their application in a non-photorealistic rendering (NPR) toll are presented

Segmentação fuzzy de imagens coloridas com características texturais: uma aplicação a rochas sedimentares

Image segmentation is the process of labeling pixels on di erent objects, an important step in many image processing systems. This work proposes a clustering method for the segmentation of color digital images with textural features. This is done by reducing the dimensionality of histograms of color images and using the Skew Divergence to calculate the fuzzy a nity functions. This approach is appropriate for segmenting images that have colorful textural features such as geological, dermoscopic and other natural images, as images containing mountains, grass or forests. Furthermore, experimental results of colored texture clustering using images of aquifers' sedimentary porous rocks are presented and analyzed in terms of precision to verify its e ectiveness.

Cell-mediated immune response to Leishmania chagasi experimental infection of BALB/c immunosuppressed mice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise isotópica (δ¹³C) e legalidade em néctares de uva

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fuzzy subset approach in coupled population dynamics of blowflies

This paper is a study on the population dynamics of blowflies employing a density-dependent. non-linear mathematical model and a coupled population formalism. In this Study, we investigated the coupled population dynamics applying fuzzy subsets to model the Population trajectory. analyzing demographic parameters such as fecundity, Survival, and migration. The main results suggest different possibilities in terms of dynamic behavior produced by migration in coupled Populations between distinct environments and the rescue effect generated by the connection between populations. It was possible to conclude that environmental heterogeneity can play an important role in blowfly metapopulation systems. The implications of these results for population dynamics of blowflies are discussed.

Immunity in plants and animals: common ends through different means using similar tools

A comparative approach is potentially useful for understanding the role of mammal innate immunity role in stimulating adaptive immunity as well as the relationship between these two types of immune strategies. Considerable progress has been made in the elucidation of the co-ordinated events involved in plant perception of infection and their mobilisation of defence responses. Although lacking immunoglobulin molecules, circulating cells, and phagocytic processes, plants successfully use pre-formed physical and chemical innate defences, as well as inducible adaptive immune strategies. In the present paper, we review some shared and divergent immune aspects present in both animals and plants. (C) 2002 Elsevier B.V. All rights reserved.

Quasispecies of hepatitis C virus genotype 1 and treatment outcome with Peginterferon and Ribavirin

The majority of patients with chronic hepatitis C fail to respond to antiviral therapy. The genetic basis of this resistance is unknown. The quasispecies nature of HCV may have an important implication concerning viral persistence and response to therapy. The HCV nonstructural 5A (NS5A) protein has been controversially implicated in the inherent resistance of HCV to interferon (IFN) antiviral therapy. To evaluate whether the NS5A quasispecies pre-treatment composition of HCV 1a/1b is related to responsiveness to combined pegylated interferon (PEG-IFN) and Ribavirin therapy, detailed analyses of the complete NS5A were performed. Fifteen full-length NS5A clones were sequenced from 11 pretreatment samples of patients infected with genotype 1 HCV (3 virological sustained responders, 4 non-responders, and 4 end-of-treatment responders). Our study could not show a significant correlation between the mean number of mutations in HCV NS5A before treatment and treatment outcome, and the phylogenetic construction of complete NS5A sequences obtained from all patients failed to show any clustering associated with a specific response pattern. No single amino acid position was associated with different responses to therapy in any of the NS5A regions analyzed, and mutations were clustered downstream the ISDR, primarily in the V3 region. We observed that the CRS and NLS regions of the NS5A protein were conflicting for some variables analyzed, although no significant differences were found. If these two regions can have antagonistic functions, it seems viable that they present different mutation profiles when compared with treatment response. The patient sample that presented the lowest genetic distance values also presented the smallest number of variants, and the most heterogeneous pattern was seen in the end-of-treatment patients. These results suggest that a detailed molecular analysis of the NS5A region on a larger sample size may be necessary for understanding its role in the therapy outcome of HCV 1a/1b infection. (C) 2008 Elsevier B.V. All rights reserved.

New Insight into the Mechanism of Action of Wasp Mastoparan Peptides: Lytic Activity and Clustering Observed with Giant Vesicles

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Retention Characteristics of CBTi144 Thin Films Explained by Means of X-Ray Photoemission Spectroscopy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sensibilidade toxicológica e especificidade do teste de microfixação de complemento na detecção de toxinas botulínicas C e D em meio de cultura e fígado de camundongos

No presente estudo pretendeu-se verificar a sensibilidade toxicológica e especificidade do Teste de Microfixação de Complemento (MCF) na detecção de toxinas botulínicas C e D no sobrenadante de cultivos bacterianos e em fígados de camundongos inoculados com doses letais e subletais. As toxinas foram produzidas em meio de cultura Hemoline, tituladas através da determinação da DL50 pelo Bioensaio em Camundongo e diluídas nas concentrações de 10, 1, 0,1, 0,01 e 0,001 DL50. Desta forma, foram utilizadas em dois modelos experimentais, onde foi determinada a sensibilidade toxicológica do MCF no sobrenadante do meio de cultura com as diluições descritas acima e ainda em extratos hepáticos de camundongos com peso corporal de 20g, inoculados com as mesmas diluições. A tentativa de evidenciação das toxinas botulínicas nos extratos hepáticos de camundongos foi realizada através da sua extração após a morte pela administração das doses letais e ainda pelo sacrifício dos animais inoculados com doses subletais, em intervalos de 5 dias. Os resultados evidenciaram uma sensibilidade toxicológica para o MCF de 100% para os dois tipos de toxinas ao nível de 0,01 DL50, quando testados os sobrenadantes de meio de cultura, portanto 100 vezes superior ao Bioensaio em Camundongo. A sensibilidade toxicológica do MCF, quando examinados extratos hepáticos de camundongos inoculados com 1 e 10 DL50 de toxinas botulínicas C e D, foi inferior, com valores de 100, 80, 89 e 72%, respectivamente. Pelo teste foi possível detectar toxinas botulínicas tipos C e D nos extratos hepáticos de camundongos inoculados com doses subletais até 15 dias após a sua inoculação. A especificidade do MCF foi de 88 e 92%, quando testados extratos hepáticos de camundongos sadios, e confrontados com as antitoxinas C e D; e 100% no sobrenadante do meio de cultura. Os resultados apontam para uma possível utilização do teste como importante instrumento de pesquisa e ainda na eventual substituição dos testes in vivo pelas suas implicações éticas e limitações práticas.

Establishing the risk of neonatal mortality using a fuzzy predictive model

O objetivo do artigo foi avaliar o uso da lógica fuzzy para estimar possibilidade de óbito neonatal. Desenvolveu-se um modelo computacional com base na teoria dos conjuntos fuzzy, tendo como variáveis peso ao nascer, idade gestacional, escore de Apgar e relato de natimorto. Empregou-se o método de inferência de Mamdani, e a variável de saída foi o risco de morte neonatal. Criaram-se 24 regras de acordo com as variáveis de entrada, e a validação do modelo utilizou um banco de dados real de uma cidade brasileira. A acurácia foi estimada pela curva ROC; os riscos foram comparados pelo teste t de Student. O programa MATLAB 6.5 foi usado para construir o modelo. Os riscos médios foram menores para os que sobreviveram (p < 0,001). A acurácia do modelo foi 0,90. A maior acurácia foi com possibilidade de risco igual ou menor que 25% (sensibilidade = 0,70, especificidade = 0,98, valor preditivo negativo = 0,99 e valor preditivo positivo = 0,22). O modelo mostrou acurácia e valor preditivo negativo bons, podendo ser utilizado em hospitais gerais.

Utilização das recomendações de nutrientes para estimar prevalência de consumo insuficiente das vitaminas C e E em gestantes

Na gestação ocorrem adaptações que conduzem a um aumento da taxa metabólica basal, caracterizando um estado de alto nível de estresse oxidativo, tornando relevante a avaliação do consumo de nutrientes antioxidantes por mulheres grávidas. Este estudo teve como objetivo estimar a prevalência de consumo insuficiente das vitaminas C e E em gestantes assistidas em serviços públicos de saúde. Estudou-se amostra (n=107) representativa das mulheres no segundo trimestre gestacional atendidas durante o pré-natal nas unidades de atenção básica do município de Botucatu/SP. O consumo foi investigado mediante dois inquéritos recordatórios de 24 horas. Para estimar a prevalência de inadequação de consumo na população, foi utilizado o método EAR como ponto de corte. Diferenças de consumo (em tercis) em relação a fatores socioeconômicos, obstétricos e hábitos de vida foram pesquisadas mediante análise estratificada, adotando-se p<0.05 como nível de significância. As prevalências estimadas de consumo insuficiente das vitaminas C e E foram 60% e 91,5%, respectivamente. Houve associação inversa entre o consumo de vitamina E com paridade e o consumo de vitamina C foi menor nas adolescentes em relação às adultas. Estes resultados indicam a necessidade de intervenções individuais e coletivas de promoção e apoio ao consumo de alimentação saudável por mulheres em idade fértil. Conclui-se que a prevalência de inadequação do consumo das vitaminas C e E é elevada e sem contrastes socioeconômicos.