84 resultados para 348-C0002P


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This study examines the unpalatability of Hyla semilineata tadpoles, relating this possible defence mechanism to their black, presumably aposematic, colouration. Bullfrog tadpoles (Rana catesbeiana), similar in size to the H. semilineata larvae, were used as controls in the experiments. The palatability of H. semilineata tadpoles was tested by offering the tadpoles to Fish (Hoplias malabaricus), free-ranging passerine birds (Pitangus sulphuratus) and hawks (Buteo magnirostris), and domestic chickens (Gallus domesticus). All predators showed a significant preference towards the control R. catesbeiana tadpoles. However, in experiments with fish, this preference was not significant for tadpole capture, only for their ingestion, suggesting that the fish could not distinguish between the two species before tasting them. Although great kiskadees (P. sulphuratus) preferred the control R. catesbeiana tadpoles, they promptly ingested more than half of the test H. semilineata tadpoles when these were offered alone. The chickens, used as naive predators, clearly learned to avoid the black H. semilineata tadpoles after a few trials. The conspicuous colouration and unpalatability of H. semilineata tadpoles may benefit the individual as well as the group, depending on the predator involved.

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

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Phylogeographic trends in Batrachospermum macrosporum Mont. were investigated using the mitochondrial intergenic spacer between the cytochrome oxidase subunit 2 and 3 genes (cox2-3). A total of 11 stream segments were sampled with seven in the coastal plain of North America and four in tropical areas of South America. Fifteen thalli were sampled from seven streams, 14 thalli from two streams, and eight thalli from two streams. There were 16 haplotypes detected using 149 individuals. of the eight haplotypes from locations in North America, all were 334 base pairs (bp) in length, and of those from South America, five were 344 bp, and three were 348 bp. Two individual networks were produced: one for the haplotypes from North America and another for those from South America, and these could not be joined due to the large number of base pair differences. This split between haplotypes from North and South America was confirmed with sequence data of the rbcL gene. There was very little genetic variation among the haplotypes from the North American locations, leading us to hypothesize that these are fairly recent colonization events along the coastal plain. In contrast, there was high variation among haplotypes from South America, and it would appear that the Amazon serves as a center of diversity. We detected considerable variation in haplotypes among streams, but frequently, a single haplotype in an individual stream segment, which is consistent with data from previous studies of other batrachospermalean taxa, may suggest a single colonization event per stream.

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

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Claudins (CLDNs) are a family of membrane proteins important for permeability of tight junctions. They have also been implicated in carcinogenesis and tumor progression. We analyzed patterns of distribution and intensity of expression of CLDNs 1, 3, 4, and 7 in mucoepidermoid carcinoma (MEC) of salivary gland in 39 patients. Correlations between the expression of CLDNs, tumor grade, and survival were explored. In immunohistochemical analysis, high expression of CLDN 1 was seen in low-grade MEC, and it appeared to be a suitable auxiliary marker of good prognosis. It classified MEC similarly to histological grading in 89.7% of cases (p=0.001). High CLDN 3 expression was seen in intermediate-and high-grade MEC, while it was low in low-grade MEC. CLDN 3 intensity correctly categorized tumors into grades in 71.8% of cases (p=0.017). However, in multivariate analysis CLDN 1 and CLDN 3 did not achieve significance over tumor grade in predicting patient behavior. We conclude that analysis of staining intensities of CLDN 1 and 3 is useful as an auxiliary diagnostic and prognostic tool in patients with salivary gland MEC.

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Objective. To examine the histomorphologic and histomorphometric features of tissue from 3 unrelated families with hereditary gingival fibromatosis (HGF).Study design. Twelve affected individuals from 3 HGF families and 3 control subjects were evaluated. Gingival samples were fixed in formalin and embedded in paraffin for hematoxylin and eosin stain to count the number of fibroblast and inflammatory cells. Sirius red staining was performed to quantitate the amount of collagen present.Results. Histomorphologic analysis of HGF showed extension of epithelial rete ridges into the underlying lamina propria and the presence of collagen bundles in the connective tissue. Analysis of the mean area fraction of collagen showed that there were significant increases in the collagen fraction for all HGF types compared with control subjects (P < .05). There were significant increases in the number of fibroblasts for HGFa and HGFb compared with control subjects (P < .05). The number of fibroblasts for HGFc were similar to that for control subjects.Conclusions. The collagen fraction was significantly greater in all HGF types compared with controls. The number of fibroblasts was significantly increased in 2 of the 3 HGF types compared with controls. These data indicate that different mechanisms may be responsible for tissue enlargement in different forms of HGF.

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Cooper pairing is studied in three dimensions to determine its binding energy for all coupling using a general separable interfermion interaction. Also considered are Cooper pairs (CPs) with nonzero center-of-mass momentum (CMM). A coupling-independent linear term in the CMM dominates the pair excitation energy in weak coupling and/or high fermion density, while the more familiar quadratic term prevails only in the extreme low-density (i.e., vacuum) limit for any nonzero coupling. The linear-to-quadratic crossover of the CP dispersion relation is analyzed numerically, and is expected to play a central role in a model of superconductivity (and superfluidity) simultaneously accommodating a Bardeen-Cooper-Schrieffer condensate as well as a Bose-Einstein condensate of CP bosons. (C) 2001 Elsevier B.V. B,V. All rights reserved.

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We perform a complete simulation of the process e(+)e(-) --> tau(+)tau(-)nu(ν) over bar where nu can be an electron, muon or tau neutrino, in the context of a general Higgs coupling to tau-leptons. We analyse various kinematical distributions and obtain the sensitivity regions in the parameter space that can be explored at a future e(+)e(-) collider. In particular, inclusion of W boson fusion enhances the sensitivity significantly.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Disordered and crystalline Ba0.45Sr0.55TiO3 (BST) powder processed at low temperature was synthesized by the polymeric precursor method. The single-phase perovskite structure of the ceramics was identified by the Raman and X-ray diffraction techniques. Photoluminescence at room temperature was observed only in a disordered BST sample. Increasing the calcination time intensified the photoluminescence (PL), which reached its maximum value in the sample heat treated at 300 degrees C for 30 h. This emission may be correlated with the structural disorder. Periodic ab initio quantum-mechanical calculations using the CRYSTAL98 program can yield important information regarding the electronic and structural properties of crystalline and disordered solids. The experimental and theoretical results indicate the presence of intermediary energy levels in the band gap. This is ascribed to the break in symmetry, which is responsible for visible photoluminescence in the material's disordered state at room temperature. (c) 2005 Elsevier B.V. All rights reserved.

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

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O Vírus Respiratório Sincicial Humano (VRSH) é descrito como o mais importante patógeno viral causador de doenças respiratórias agudas das vias respiratórias inferiores em crianças. Neste estudo 84 amostras de crianças com idade abaixo dos dois anos apresentando sintomas de doença respiratória aguda, foram obtidas no período de setembro de 2000 a novembro de 2001. Analise por imunofluorescência indireta e transcrição reversa seguida de PCR, revelou que 18% (15/84) das amostras foram positivas, sendo que em 80% (12/15) dos casos a detecção de VRSH foi observada em crianças abaixo dos seis meses, e também que os subgrupos A e B co-circularam. Estes são os primeiros dados obtidos para a cidade de Botucatu, sendo que a sazonalidade mostrou-se evidente pela maior circulação desse vírus entre os meses de maio e julho

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CONTEXTO: A desnutrição protéico-energética constitui causa previsível para o desenvolvimento de complicações pós-operatórias e pior prognóstico de pacientes cirúrgicos. OBJETIVO: Estudar a associação de indicadores de estado nutricional com estádio da doença e as principais complicações e mortalidade pós-operatória de pacientes com câncer de esôfago. MÉTODO: Foram avaliados retrospectivamente 100 prontuários de pacientes com câncer de esôfago (38-81 anos) de ambos os sexos (85% masculino e 15% feminino) submetidos a esofagectomia (n = 25) e gastrojejunostomia (n = 75), no período de 1995 a 2004. Os dados coletados foram: história clínica, exame endoscópico, estádio (TNM-UICC), estado nutricional (índice de massa corporal, percentual de perda de peso - %PP, albuminemia e contagem de linfócitos total) e evolução clínica pós-operatória. Houve composição dos grupos de acordo com o porte da cirurgia (grande x pequeno). Foi realizada a associação entre as complicações pós-operatórias e a mortalidade (após pós-operatório de 30 dias). As comparações entre médias dos dois grupos foram feitas pelo teste t de Student e a existência de associações entre variáveis testadas pelos testes de χ2 ou exato de Fisher com P = 0,05. RESULTADOS: Houve predomínio dos tumores avançados (estádio III e IV), com a presença de disfagia em 95% dos pacientes e perda ponderal >10%, anterior ao diagnóstico, em 78%. A obstrução esofágica, presente em 77 pacientes, foi associada (P = 0,0021) com o baixo índice de massa corporal (desnutrição protéico-energética). A %PP e a hipoalbuminemia associaram-se estatisticamente (P<0,05) com o estádio avançado da doença. As complicações pós-operatórias precoces ocorreram em 69,2% e 30,7% dos pacientes submetidos a esofagectomia e ostomias, respectivamente, com predomínio das infecciosas nas ostomias (80%) e as pleuropulmonares nas esofagectomias (61%). A albuminemia foi menor nos pacientes submetidos as ostomias, tendo sido a hipoalbuminemia associada (P<0,05) com a ocorrência de complicações pós-operatórias e mortalidade. A %PP e a contagem de linfócitos total associaram-se com as complicações pós-operatórias precoces e infeccionas nas ostomias e a contagem de linfócitos total, com a mortalidade operatória nas esofagectomias. CONCLUSÕES: O estado de DPE esteve associado às complicações pós-operatórias apenas nos pacientes submetidos a ostomias, sem presença destas associações nas esofagectomias.