A hybrid approach to learn with imbalanced classes using evolutionary algorithms

There is an increasing interest in the application of Evolutionary Algorithms (EAs) to induce classification rules. This hybrid approach can benefit areas where classical methods for rule induction have not been very successful. One example is the induction of classification rules in imbalanced domains. Imbalanced data occur when one or more classes heavily outnumber other classes. Frequently, classical machine learning (ML) classifiers are not able to learn in the presence of imbalanced data sets, inducing classification models that always predict the most numerous classes. In this work, we propose a novel hybrid approach to deal with this problem. We create several balanced data sets with all minority class cases and a random sample of majority class cases. These balanced data sets are fed to classical ML systems that produce rule sets. The rule sets are combined creating a pool of rules and an EA is used to build a classifier from this pool of rules. This hybrid approach has some advantages over undersampling, since it reduces the amount of discarded information, and some advantages over oversampling, since it avoids overfitting. The proposed approach was experimentally analysed and the experimental results show an improvement in the classification performance measured as the area under the receiver operating characteristics (ROC) curve.

Programmable diagnostic devices made from paper and tape

This paper describes three-dimensional microfluidic paper-based analytical devices (3-D mu PADs) that can be programmed (postfabrication) by the user to generate multiple patterns of flow through them. These devices are programmed by pressing single-use 'on' buttons, using a stylus or a ballpoint pen. Pressing a button closes a small space (gap) between two vertically aligned microfluidic channels, and allows fluids to wick from one channel to the other. These devices are simple to fabricate, and are made entirely out of paper and double-sided adhesive tape. Programmable devices expand the capabilities of mu PADs and provide a simple method for controlling the movement of fluids in paper-based channels. They are the conceptual equivalent of field-programmable gate arrays (FPGAs) widely used in electronics.

The Neotropical genus Stibadocerina Alexander and its phylogenetic relationship to other Stibadocerinae genera: further evidence of an ancestral trans-Pacific biota (Diptera: Cylindrotomidae)

Stibadocerina Alexander, a monotypic genus, includes the only known Neotropical species of the family Cylindrotomidae, S. chilensis Alexander, 1929, from South Central Chile (ca. 36 degrees 50`S-42 degrees 17`S). In this paper, Stibadocerina chilensis is redescribed and illustrated in detail. A study of wing-vein homology in the subfamily Stibadocerinae is provided, to identify the components of the reduced radial sector in Stibadocerina and related taxa. The proposed hypotheses of wing-vein homology are tested, and the systematic position of Stibadocerina is assessed through a cladistic analysis of 13 characters of the male imago, scored for exemplar species of the four genera included in the Stibadocerinae. A single most parsimonious tree supports the monophyly of the Stibadocerinae and the following relationships among its included genera: Stibadocerodes [Stibadocera (Stibadocerella + Stibadocerina)]. The subfamily includes one example of a vicariant distribution with a sister-group relationship between South Central Chilean and East Asian taxa, and supports a biogeographical interpretation of an ancestral trans-Pacific biota.

Ticks (Acari : ixodidae) infesting wild birds in an Atlantic forest area in the state of Sao Paulo, Brazil, with isolation of Rickettsia from the tick Amblyomma longirostre

During field work in Nazare Paulista, state of Sao Paulo, Brazil, we found 13 (56.5%) of 23 birds (mostly Passeriformes) to be infested by 28 larvae and I nymph of Amblyomma spp. Two larvae were reared to the adult stage, being taxonomically identified as Amblyomma parkeri Fonseca and Aragao, whereas five larvae and one nymph were identified as Amblyomma longirostre Koch. All six A. longirostre specimens were shown to be infected by rickettsia, as demonstrated by polymerase chain reaction (PCR) targeting two rickettsial genes (gltA and ompA) or isolation of rickettsia in cell culture from one of the ticks. This isolate was designated as strain AL, which was established in Vero cell culture and was molecularly characterized by DNA sequencing fragments of the rickettsial genes gltA, htrA, ompA, and ompB. Phylogenetic analyses inferred from ompA and ompB partial sequences showed a high degree of similarity of strain AL with Rickettsia sp. strain ARANHA, previously detected by PCR in A. longirostre ticks from Rondonia, northern Brazil. We conclude that strain AL is a new rickettsia genotype belonging to the same species of strain ARANHA, which are closely related to Candidatus `R. amblyomniii`. Further studies should elucidate if strains AL and ARANHA are different strains of Candidatus `R. amblyommii` or are a new species.

Rickettsial infection in Amblyomma nodosum ticks (Acari: Ixodidae) from Brazil

The rickettsial infections in 174 Amblyomma nodosum found on passeriform birds in the Atlantic forest, eastern Brazil, have recently been evaluated. Rickettsiae were successfully isolated from two ticks, using cultures of Vero cells. Both isolates were molecularly characterised, using the rickettsial genes gltA and htrA and, when possible, also ompA and ompB. Portions of the gltA and htrA genes from one of the rickettsial isolates were found be closely match the corresponding GenBank sequences for Rickettsia bellii, with 99.9% and 100% homology, respectively. This isolate was named R. bellii strain Pontal. Portions of the gltA, htrA and ompB genes from the second isolate most closely matched the corresponding sequences of R. parkeri, whereas a portion of the ompA gene from this isolate was closest to the relevant sequence of Rickettsia sp. strain COOPERI (which has been considered to be a strain of R. parkeri in Brazil). The second isolate was named R. parkeri strain NOD. Further investigation of the 172 ticks from which isolates were not recovered revealed R. parkeri strain NOD in 40 and R. bellii strain Pontal in nine, giving overall infection prevalences of 23.6% (41/174) and 5.7% (10/174), respectively. This appears to be the first report of R. bellii and R. parkeri in A. nodosum.

Incidence of Listeria monocytogenes in Cheese Manufacturing Plants from the Northeast Region of Sao Paulo, Brazil

The incidence of Listeria monocytogenes in three cheese manufacturing plants from the northeastern region of Sao Paulo, Brazil, was evaluated from October 2008 to September 2009. L. monocytogenes was found in samples from two plants, at percentages of 13.3% (n = 128) and 9.6% (n = 114). Samples of raw and pasteurized milk, water, and Minas Frescal cheese were negative for L. monocyto genes, although the pathogen was isolated from the surface of Prato cheese and in brine from one of the plants evaluated. L. monocytogenes was also isolated from different sites of the facilities, mainly in non food contact surfaces such as drains, floors, and platforms. Serotype 4b was the most predominant in the plants studied. The results of this study indicate the need for control strategies to prevent the dispersion of L. monocytogenes in the environment of cheese manufacturing plants.

Evidence for the conspecificity of Palisada papillosa with P. perforata (Ceramiales, Rhodophyta) from the western and eastern Atlantic Ocean on the basis of morphological and molecular analyses

Morphological and molecular studies were carried out on Palisada papillosa and P. perforata from the Canary Islands (type locality of P. perforata), Mexico and Brazil. The two species have been distinguished by features of their external morphology such as size and degree of compactness of the thalli, presence or absence of arcuate branches, branching pattern and basal system. A detailed morphological comparison between these taxa showed that none of the vegetative anatomical or reproductive characters was sufficient to separate these species. The presence or absence of cortical cells in a palisade-like arrangement, also previously used to. distinguish these species, is not applicable. The species present all characters typical of the genus, and both share production of the first pericentral cell underneath the basal cell of the trichoblast, production of two fertile pericentral cells (the second and the third additional, the first remaining sterile), spermatangial branches produced from one of two laterals on the suprabasal cell of trichoblasts, and the procarpbearing segment with four pericentral cells. Details of the procarp are described for the species for the first time. The phylogenetic position of these species was inferred by analysis of the chloroplast-encoded rbcL gene sequences from 39 taxa, using one other Rhodomelacean taxon and two Ceramiaceae as outgroups. Relationships within the clade formed by P. papillosa and P. perforata have not been resolved due to the low level of genetic variation in their rbcL sequences (0-0.4%). Considering this and the morphological similarities, we conclude that P. papillosa is a taxonomic synonym of P. perforata. The phylogenetic analyses also supported the nomenclatural transfer of two species of Chondrophycus to Palisada, namely, P. patentiramea (Montagne) Cassano, Senties, Gil-Rodriguez & M.T. Fujii comb. nov. and P. thuyoides (Kutzing) Cassano, Senties, Gil-Rodriguez & M.T. Fujii comb. nov.

Learning of shared attention in sociable robotics

Sociable robots are embodied agents that are part of a heterogeneous society of robots and humans. They Should be able to recognize human beings and each other, and to engage in social, interactions. The use of a robotic architecture may strongly reduce the time and effort required to construct a sociable robot. Such architecture must have structures and mechanisms to allow social interaction. behavior control and learning from environment. Learning processes described oil Science of Behavior Analysis may lead to the development of promising methods and Structures for constructing robots able to behave socially and learn through interactions from the environment by a process of contingency learning. In this paper, we present a robotic architecture inspired from Behavior Analysis. Methods and structures of the proposed architecture, including a hybrid knowledge representation. are presented and discussed. The architecture has been evaluated in the context of a nontrivial real problem: the learning of the shared attention, employing an interactive robotic head. The learning capabilities of this architecture have been analyzed by observing the robot interacting with the human and the environment. The obtained results show that the robotic architecture is able to produce appropriate behavior and to learn from social interaction. (C) 2009 Elsevier Inc. All rights reserved.

The role of pH on the survival of rumen protozoa in steers

In order to study the effect of pH on defaunation in the rumen, four rumen fistulated steers were fed a basal roughage diet for a 4-week adaptation period followed by 17 weeks of feeding with three diets and two feeding levels of high concentrate diet. Rumen outflow fluid rate was evaluated in both ration levels. Rumen protozoa population was monitored weekly and when animals became defaunated, protozoa were reinoculated with rumen contents from one of the faunated steers. At every two weeks, during all the experimental period, rumen pH was measured in all animals at 0, 4, 8 and 12 h after feeding. It was observed an individual animal influence on the establishment and maintenance of the rumen ciliate protozoa population. In all sampling times, mean rumen pH values were higher in faunated steers than in the defaunated ones. No differences were observed in rumen outflow fluid rates between the two ration levels. Extended periods of low rumen pH are probably more detrimental to the survival of ciliate protozoa in the rumen than other factors.

As implicações sociais da deficiência auditiva adquirida em adultos

O objetivo deste estudo foi analisar as implicações da surdez adquirida em adultos, na vida familiar, social e no trabalho, com uma abordagem qualitativa. Foram selecionadas 27 pessoas residentes em Bauru-SP, com diagnóstico de perda auditiva de manifestação súbita na faixa etária de 18 a 60 anos, matriculados no Hospital de Reabilitação de Anomalias Craniofaciais (HRAC/USP) entre janeiro de 2000 e fevereiro de 2005, sendo entrevistados 16. Utilizaram-se a entrevista e a análise de conteúdo. Constatou-se: a perda auditiva ocorreu entre os 40 e 44 anos, 37,5%; 62,5% dos que perderam a audição eram do sexo masculino, 62,5% não tinham o ensino fundamental; 62,5% eram da classe Baixa Superior; 75% apresentaram perda auditiva bilateral, 18,75% de grau moderado/profundo. Dos 13 que estavam trabalhando quando perderam a audição, 30,77% pararam de trabalhar e 15,38% mudaram de profissão. Foram relatadas situações como: afastamento do trabalho, demissão a pedido e demissão pelo empregador, dificuldade de aceitação, cobranças, falta de esclarecimentos e desconhecimento dos próprios profissionais de saúde. Os dados sugerem a necessidade dos recursos de reabilitação, de apoio terapêutico, respeito e alternativas de conhecimentos.

Validação do Questionário de Freqüência Alimentar para Adolescentes (QFAA) por grupos de alimentos em uma população de escolares

OBJETIVO: Verificar a validade do Questionário de Freqüência Alimentar para Adolescentes para avaliar o consumo de grupos de alimentos entre escolares de Piracicaba, São Paulo. MÉTODOS: Participaram do estudo 94 adolescentes, com idade entre 11 e 15 anos, matriculados em uma escola da rede pública. O consumo alimentar foi avaliado pelo Questionário de Freqüência Alimentar para Adolescentes (QFAA) e a média de dois Recordatórios de 24 horas (R24h) foi utilizada como método de referência. Os itens alimentares foram classificados em 18 grupos. Foram realizadas análises descritivas, teste t-Student pareado e de Wilcoxon, coeficientes de correlação de Pearson e de Spearman. Foram também utilizadas análise de quartis e estatística Kappa ponderado. Os coeficientes de correlação foram corrigidos pela variância intrapessoal dos R24h, estimada a partir de ANOVA com um fator de classificação. RESULTADOS: Não foram verificadas diferenças significativas entre os instrumentos para o arroz, massas, carnes, refrigerantes e sucos artificiais. Os coeficientes de correlação corrigidos pela variabilidade intrapessoal variaram de -0,26 a 0,78. A concordância de classificação dos indivíduos no mesmo quartil de consumo para ambos os métodos variou de 22% (massas) a 50% (feijão). Para quartis opostos, os grupos que tiveram mais de 10% dos indivíduos classificados incorretamente foram massas (19%), carnes (13%) e gorduras (11%). Os valores de Kappa ponderado variaram de - 0,15 (massas) a 0,56 (feijão). O QFAA superestimou o consumo de quase a totalidade dos grupos alimentares e subestimou os grupos dos óleos, feijão, carnes e refrigerantes. CONCLUSÃO: O instrumento apresentou boa validade para feijão, verduras e legumes, leite e derivados, biscoitos recheados e para o arroz.

Características clínicas da fase aguda da infecção experimental de felinos pelo vírus da imunodeficiência felina

A infecção dos felinos pelo Vírus da Imunodeficiência Felina (FIV) resulta no desenvolvimento da síndrome de imunodeficiência dos felinos. Gengivite, perda de peso, linfadenomegalia generalizada, anemia, insuficiência renal crônica, complicações neurológicas, diarréia crônica e infecções bacterianas são encontradas frequentemente. A fase aguda da infecção pode ser assintomática, retardando o estabelecimento do diagnóstico e a implantação de medidas profiláticas para restringir o contágio e a transmissão do agente aos felinos suscetíveis. Com a finalidade de estudar as características clínicas da fase aguda da infecção, dez felinos jovens, sem definição racial, com oito meses de idade foram inoculados por via endovenosa com 1mL de sangue venoso de um gato portador do FIV subtipo B. A confirmação da infecção foi obtida através de teste sorológico em quatro e oito semanas pós-inoculação (p.i.) e por nested-PCR. Foram realizados hemogramas semanais, exame ultrassonográfico do abdômen quinzenais e exame oftalmológico mensal, durante doze semanas p.i. Discreta tendência a linfopenia na segunda semana p.i. e a neutropenia entre a quinta e sétima semana p.i., febre intermitente em alguns gatos, linfadenomegalia e hepato-esplenomegalia entre a quarta e a 12ª semana p.i. foram as alterações clínicas observadas. Apenas um gato apresentou uveíte unilateral direita. A fase aguda da infecção transcorreu com alterações clínicas inespecíficas. A linfadenomegalia e a hepato-esplenomegalia observadas no decorrer da infecção, refletindo hiperplasia linfóide, sugerem a necessidade de se realizar o teste sorológico para o FIV, em todos os gatos que se apresentarem com essas alterações, o que permitirá o diagnóstico precoce da infecção e a adoção de medidas profiláticas no sentido de minimizar a propagação da infecção.

Hipersensibilidade alimentar em cães

Realizou-se um estudo retro e prospectivo em 117 cães com prontuários suspeitos de apresentarem hipersensibilidade alimentar. Os animais foram distribuídos em dois grupos: os do grupo I (n=86) foram atendidos em 1993 e 1994 e os do grupo II (n=31) em 1995. Os cães de ambos os grupos foram caracterizados quanto aos aspectos epidemiológicos e clínicos. Os do grupo II foram submetidos a exames complementares para a diferenciação diagnóstica do prurido, incluindo: hemograma, micológico e parasitológico cutâneo, coproparasitológico, histológico de pele e sorológicos - RAST (radioimunoensaio) e ELISA (ensaio imunoenzimático) - ambos para determinação de IgE contra antígenos alimentares -, e ao exame da dieta de eliminação seguida pela exposição provocativa. Este último exame foi o mais confiável para o estabelecimento do diagnóstico, ao determinar que 20 cães, provenientes de ambos os grupos, eram alérgicos a alimentos. Pelos RAST e ELISA, não foi possível demonstrar resultados confiáveis quando comparados aos resultados com a dieta de eliminação. Os animais acometidos foram principalmente machos, com raça definida e na faixa etária de um a seis anos. Os principais alimentos incriminados foram a carne bovina, o arroz e a carne de frango.

Sensitivity evaluation of a single-step PCR assay using Ehrlichia canis p28 gene as a target and its application in diagnosis of canine ehrlichiosis

The aim of this study was to optimize a PCR assay that amplifies an 843 pb fragment from the p28 gene of Ehrlichia canis and compare it with two other PCR methods used to amplify portions of the 16S rRNA and dsb genes of Ehrlichia. Blood samples were collected from dogs suspected of having a positive diagnosis for canine ehrlichiosis. Amplification of the p28 gene by PCR produced an 843-bp fragment and this assay could detect DNA from one gene copy among 1 billion cells. All positive samples detected by the p28-based PCR were also positive by the 16S rRNA nested-PCR and also by the dsb-based PCR. Among the p28-based PCR negative samples, 55.3% were co-negatives, but 27.6% were positive in 16S rRNA and dsb based PCR assays. The p28-based PCR seems to be a useful test for the molecular detection of E. canis, however improvements in this PCR sensitivity are desired, so that it can become an important alternative in the diagnosis of canine ehrlichiosis.

Lisina digestível e zinco quelado para frangos de corte machos: desempenho e retenção de nitrogênio na fase pré-inicial

Em dois ensaios experimentais, avaliaram-se níveis de lisina digestível (0,90; 1,00; 1,10; 1,20 e 1,40%) combinados a zinco quelado (43 e 253 ppm) para frangos de corte machos. Os períodos considerados foram: 1 a 11 dias de idade (desempenho) e 1 a 7 dias de idade (balanço de nitrogênio). O delineamento experimental utilizado foi de blocos ao acaso, em esquema fatorial 5 × 2. No ensaio de desempenho, utilizaram-se 7 repetições e 15 aves por unidade experimental e, no ensaio de digestibilidade, 6 repetições e 6 aves por unidade experimental. As dietas continham 2.960 de EM/kg e 21% de proteína bruta. Na fase de 1 a 11 dias de idade, não houve efeito de interação lisina digestível × zinco quelado no desempenho, mas verificou-se efeito quadrático dos níveis de lisina digestível sobre o peso final, o ganho de peso e o ganho de peso relativo e efeito linear crescente no consumo de ração. A conversão alimentar não diferiu com as variações dos níveis de lisina digestível e zinco na dieta. Nas condições de avaliação do desempenho, o nível ótimo de lisina digestível para frangos de corte machos mantidos em piso de concreto é de 1,19%. Na fase de 1 a 7 dias de idade, não houve influência da relação entre níveis de lisina digestível e zinco quelado no balanço de nitrogênio. A retenção de nitrogênio aumentou de forma linear crescente com o aumento da concentração de lisina digestível na dieta, o que está de acordo com o aumento linear do ganho de peso e da eficiência alimentar. A exigência de lisina digestível para frangos de corte machos de 1 a 7 dias de idade é igual ou superior a 1,40%.