Aplicação de técnicas de aprendizado de máquina no reconhecimento de classes estruturais de proteínas

Nowadays, classifying proteins in structural classes, which concerns the inference of patterns in their 3D conformation, is one of the most important open problems in Molecular Biology. The main reason for this is that the function of a protein is intrinsically related to its spatial conformation. However, such conformations are very difficult to be obtained experimentally in laboratory. Thus, this problem has drawn the attention of many researchers in Bioinformatics. Considering the great difference between the number of protein sequences already known and the number of three-dimensional structures determined experimentally, the demand of automated techniques for structural classification of proteins is very high. In this context, computational tools, especially Machine Learning (ML) techniques, have become essential to deal with this problem. In this work, ML techniques are used in the recognition of protein structural classes: Decision Trees, k-Nearest Neighbor, Naive Bayes, Support Vector Machine and Neural Networks. These methods have been chosen because they represent different paradigms of learning and have been widely used in the Bioinfornmatics literature. Aiming to obtain an improvment in the performance of these techniques (individual classifiers), homogeneous (Bagging and Boosting) and heterogeneous (Voting, Stacking and StackingC) multiclassification systems are used. Moreover, since the protein database used in this work presents the problem of imbalanced classes, artificial techniques for class balance (Undersampling Random, Tomek Links, CNN, NCL and OSS) are used to minimize such a problem. In order to evaluate the ML methods, a cross-validation procedure is applied, where the accuracy of the classifiers is measured using the mean of classification error rate, on independent test sets. These means are compared, two by two, by the hypothesis test aiming to evaluate if there is, statistically, a significant difference between them. With respect to the results obtained with the individual classifiers, Support Vector Machine presented the best accuracy. In terms of the multi-classification systems (homogeneous and heterogeneous), they showed, in general, a superior or similar performance when compared to the one achieved by the individual classifiers used - especially Boosting with Decision Tree and the StackingC with Linear Regression as meta classifier. The Voting method, despite of its simplicity, has shown to be adequate for solving the problem presented in this work. The techniques for class balance, on the other hand, have not produced a significant improvement in the global classification error. Nevertheless, the use of such techniques did improve the classification error for the minority class. In this context, the NCL technique has shown to be more appropriated

Formação docente e gêneros discursivos:o dizer, o saber e o fazer

This master dissertation presented to the Language Studies Post-Graduation Program of the Federal University of Rio Grande do Norte aims present an analysis about the initial teacher training, the knowledge about discursive genres and its usage in basic education professional classrooms. Therefore, it was analyzed, from teachers of fourth and fifth grades of elementary schools, if the initial training provides enough useful tools to be applied in Portuguese classes, i.e., if during the teacher training process concepts of discursive genres emerge, which of these concepts can be noticed and how this knowledge helps teachers in their classrooms. In order to achieve this aim, it was taken into account studies about the initial teacher training, about the knowledge diversity that is part of the teaching knowledge and also about discursive genres based on Bakhtin‟s conception, which is used in the Parâmetros Curriculares Nacionais (PCN). This research is qualitative of interpretative basis and has taken an opened questions questionnaire and classroom observations with audio recording data as corpus of analysis. As results of this investigation, it is possible to emphasize that the initial teacher training has left some gaps in discursive genres concepts and usage in Portuguese classes, that it is not only one kind of knowledge that compound the teacher knowledge and, because of this, working with disciplinarians knowledge, specially about discursive genres, is to emphasize one among many others.

Sensor array made with nanostructured films to detect a phenothiazine compound

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

Antimycobacterial activity of lichen substances

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

Structure and antimycobacterial activity of the novel organometallic [Pd(C-bzan)(SCN)(dppp)] compound

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Chemical Profile and Biological Potential of Non-Polar Fractions from Centroceras clavulatum (C. Agardh) Montagne (Ceramiales, Rhodophyta)

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

Mutagenicity and antimutagenicity of (-)-hinokinin a trypanosomicidal compound measured by Salmonella microsome and comet assays

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

Synthesis, Characterization and Pharmacological Evaluation of 1-(2-Chloro-6-Fluorophenyl)-5-Methylindolin-2-One: A New Anti-Inflammatory Compound with Reduced Gastric Ulceration Properties

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Structure and viscoelastic behavior of pharmaceutical biocompatible anionic microemulsions containing the antitumoral drug compound doxorubicin

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

Electron spin resonance of Gd3+ in the antiferromagnetic heavy fermion CeIn3 and its reference compound LaIn3

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

General solutions for some classes of interacting two field kinks

In this work we present some classes of models whose the corresponding two coupled first-order nonlinear equations can be put into a linear form, and consequently be solved completely. In these cases the so-called trial orbit method is completely unnecessary. We recall that some physically important models as, for instance, the problem of tiling a plane with a network of defects and polymer properties are in this class of models. (c) 2005 Elsevier B.V. All rights reserved.

Família e subjetividade: tendências e particularidades das classes trabalhadoras no capitalismo contemporâneo

This work problematizes the inflections of the offensive of the capital on the work, having as a social-historical context the relation between the productive restructuring and the social reproduction of the working families classes. Part of the presupposition that the reproduction of the capital, to raise deep transformations in the productions, organization of the work and in the social relationships, it also produces determinations in the life and work conditions, in the affectionate relationships and in the family coexistence expressing, so, a subjective way. Thereby, the conditions of reproductions of the work in the scenery aimed by the contemporary capitalism have been demonstrating the crescent impoverishment of the workers, the alimentary insecurity, the shortage of the work, the weakness of the political organization and the regression of the State in the conduction of public policy that characterize the daily violation of human and social rights. In this approach, we seek to contemplate the several configurations of affectionate-sexual coexistence expressed by the family, articulating it to the contemporary work division, pondering about the forms of satisfaction of the needs engendered by the group for preservation of their bonds, in face to the daily adversity which translates to the growing responsibility to assist social d mands and in the impediments to the enrichment of the individuality and human diversity.