413 resultados para 1351
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Incluye Bibliografía
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Incluye Bibliografía
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Usando o formalismo relativístico no estudo da propagação de perturbações lineares em fluidos ideais, obtêm-se fortes analogias com os resultados encontrados na Teoria da Relatividade Geral. Neste contexto, de acordo com Unruh [W. Unruh, Phys. Rev. Letters 46, 1351 (1981)], é possível simular um espaço-tempo dotado de uma métrica efetiva em um fluído ideal barotrópico, irrotacional e perturbado por ondas acústicas. Esse espaço-tempo efetivo é chamado de espaço-tempo acústico e satisfaz as propriedades geométricas e cinemáticas de um espaço-tempo curvo. Neste trabalho estudamos os modos quasinormais (QNs) e os pólos de Regge (PRs) para um espaço-tempo acústico conhecido como buraco acústico canônico (BAC). No nosso estudo, usamos o método de expansão assintótica proposto por Dolan e Ottewill [S. R. Dolan e A. C. Ottewill, Class. Quantum Gravity 26, 225003 (2009)] para calcularmos, em termos arbitrários do número de overtone n, as frequências QNs e os momentos angulares para os PRs, bem como suas respectivas funções de onda. As frequências e as funções de onda dos modos QNs são expandidas em termos de potências inversas de L = l + 1/2 , onde l é o momento angular, enquanto que os momentos angulares e funções de onda dos PRs são expandidos em termos do inverso das frequências de oscilação do buraco acústico canônico. Comparamos os nossos resultados com os já existentes na literatura, que usam a aproximação de Wentzel-Kramers-Brillouin (WKB) como método de determinação dos modos QNs e dos PRs, e obtemos uma excelente concordância dentro do limite da aproximação eikonal (l ≥ 2 e l > n).
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The objective of this work was to evaluate the common bean response to N application timing, under no-tillage system, after single corn or intercropped with palisade grass. A randomized complete block experimental design was used in a split-plot arrangement, with four replicates. Plots consisted of: single corn crop or corn intercropped with palisade grass, in two summer cropping seasons precedent to common bean sowing. Subplots consisted of: 100 kg ha-1 N application in three times - before sowing, at sowing, and at side-dressing - and a control treatment without N application. Nitrogen fertilization on common bean increased leaf-N content, the number of pods per plant, and grain yield (33% in the average application timing), only in the cropping after single corn. By providing large mass production and by N cycling, the cultivation of palisade grass intercropped with corn reduced N requirement of common bean in succession, in comparison to previous sole corn cultivation. Early N application before or during common bean sowing time provides grain yield similar to the observed one in the side-dressing application.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Background. Despite being functional and having aesthetic benefits, the acceptance of patients regarding the use of removable partial dentures (RPDs) has been low. In part, this is due to the deleterious effects that causes discomfort to the patient. Success depends not only on the care expended by the patient, including daily care and oral hygiene, but also on common goals set by their professional and clinical staff, aiming beyond aesthetics, to incorporate issues of functionality and the well-being of patients. Methods and results. For rehabilitation treatment with RPDs to reach the desired level of success without damaging the support structure, all the steps (diagnose, cavity preparation, adaptation of the metal structures, functional of distal extension and posterior follow-up) in the rehabilitative treatment should be carefully developed. A literature review was carried out, searching through MEDLINE (PubMed) articles published between 1965 and December 2012 including clinical trials and reviews about the use of RPDs. Conclusions. This study describes factors that lead to failures and complications in oral rehabilitation through the use of RPDs and suggests possible solutions.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The main objective of the presented study is the development of a predictive interval type-2 fuzzy inference system in order to estimate the mortality risk for a newborn, to be used as an auxiliary tool for decision making in medical centers where there is a lack of professionals for this purpose and, afterwards, to compare its performance to a type-1 fuzzy system. The input variables were chosen due to their acquisition ‘simplicity, not involving any invasive tests, such as blood tests or other specific tests. The variables are easily obtained in the first few minutes of life: birth weight, gestational age at delivery, 5-minute Apgar score and previous report of stillbirth. Databases from the DATASUS were used to validate the model. 1351 records from the city of São José dos Campos, a mid-sized city in the São Paulo state’s countryside, were considered in this study. Finally, an analysis using the ROC curve was performed to estimate the model’s accuracy
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Este trabalho sustenta-se em uma compreensão de que a Educação Escolar e a Educação Sexual são processos que ocorrem na relação com o contexto social e histórico. No campo da sexualidade, o contexto social determina padrões de normalidade baseados na ideia de heteronormatividade compulsória, o que discrimina a diversidade sexual. Esta questão é ilustrada com dados de pesquisa que demonstram o relato de professores de escolas públicas sobre a homossexualidade evidenciando a falta de conhecimento sobre o assunto, o preconceito e as dificuldades em tratar o tema na escola. Ressalta-se, portanto, a importância da inserção do tema sexualidade na formação inicial e continuada dos professores.
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Accurate paleoenvironmental reconstruction relies on the correct interpretation of the postmortem history of skeletal remains in shelly assemblages. In contrast to marine settings, actualistic taphonomic studies are lacking for shell-rich concentrations in freshwater riverine systems. In particular, the taphonomic pathways and the origins of taphonomic signatures that are recorded in bioclasts from fluvial settings are poorly known. In this study, we addressed this issue by comparing the taphonomic signatures and shell-damage profiles among shells of freshwater mollusks recorded both in death and in fossil assemblages from the same fluvial environment. Our data indicated that dissolution was the most pervasive taphonomic process leading to the destruction of the shells. The loss of taphonomic information extended beyond shell dissolution in the riverbed, or the early diagenesis in the sedimentary record. The loss of biological information from the living community through the death assemblage, until the incorporation of shells as fossils, mainly occurred during the time the shells were in the sediment-water interface. Though this destruction affected primarily dead shells, reworked fossils also became vulnerable because they were carried out into the river load again by channel avulsion. A model that included the main taphonomic pathways followed by the molluscan shells in the fluvial Touro Passo Formation (Pleistocene-Holocene) is discussed. In this model, two main destructive domains were recognized, which were the biological, physical, and chemical processes operating at the taphonomically active zone (= TAZ domain) and the pedogenetic domain.
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This report covers the investigations, expenditures, and publications of the Nebraska Agricultural Experiment Station for the fiscal year June 30, 1931. During the year 68 projects have been under investigation at the main station. These have covered a wide range of subjects. At the various substations the work is planned to meet the needs of the different regions. The funds for carrying on the work of the stations are derived from federal and state sources. The work is carried on in definite projects according to the supporting fund. Satisfactory progress was made on the research program. During the year eight projects were completed and seven new ones added. The selection of new projects is on the basis of most urgent need, together with the ability of the Experiment Station to carry the project. The financial depression in which agriculture still finds itself has increased rather than decreased the demand upon the Experiment Station and the College for new and definite information. This demand has been taken care of insofar as possible. During the year covered by this report eleven bulletins, nine research bulletins, and one circular have been published by the Experiment Station. In addition 22 technical papers have been prepared by members of the staff and printed in various technical and professional journals.
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Antioxidant activity and hepatoprotective properties of the aqueous extract and tetrahydrofuran-extracted phenolic fractions of Halimeda opuntia (Linnaeus) Lamouroux were investigated in rats with chemically induced liver injury. Total polyphenols were determined by using the Folin-Ciocalteau reagent. Liver damage was induced by CCl4 and assessed by a histological technique. Reverse transcription/polymerase chain reaction (RT/PCR) analysis showed increased superoxide dismutase (SOD) and catalase (CAT) gene expression and activities in the group treated with free phenolic acid (FPA) fractions of H. opuntia, suggesting inducing effects on both enzymes. In addition, rats treated with FPA fractions displayed lower liver thiobarbituric acid reactive substance (TBARS) levels than those observed for rats in the CCl4-treated group. These data suggest that the phenolic fractions from H. opuntia may protect the liver against oxidative stress-inducing effects of chemicals by modulating its antioxidant enzymes and oxidative status.
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Electron densities of 33 samples of normal (adipose and fibroglangular) and neoplastic (benign and malignant) human breast tissues were determined through Compton scattering data using a mono-chromatic synchrotron radiation source and an energy dispersive detector. The area of Compton peaks was used to determine the electron densities of the samples. Adipose tissue exhibits the lowest values of electron density whereas malignant tissue the highest. The relationship with their histology was discussed. Comparison with previous results showed differences smaller than 4%. (C) 2012 Elsevier Ltd. All rights reserved.
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The water vapor conductance (G(H20)) of the neosauropod eggs from the Lower Cretaceous Sanagasta nesting site in La Rioja Province, Argentina, was examined and compared with other Cretaceous Argentinean oological material. The 2900 mgH(2)O/day.Torr G(H2O) of the Sanagasta eggshells confirms an extremely moist nesting environment and supports field observations of dug-out nests in a geothermal setting. The observed thinning of the outer eggshell surface during incubation increases gas conductance and concomitantly decreases eggshell mechanical resistance during the late ontogenetic stages, thus facilitating embryonic development and hatching. The Sanagasta and Entre Rios Province faveoloolithid eggs display the highest and comparable 61120 values and share several morphological and diagenetic characters, indicating comparable nesting strategy in geothermal settings. However, the faveoloolithid Yamintie and La Pampa Province specimens cluster together with lower G(H20) values closer to the megaloolithid eggs. The Gnu) of the megaloolithid egg Megaloolithus patagonicus was reconsidered and new results are now congruent with other reported megaloolithid GH2O values. Additionally, we hypothesize that V-shaped pore canals of M. patagonicus, which upper sections reach only the top third or half eggshell thickness and, a wider section in the middle would not compromise the overall egg mechanical resistance like vertical pores connecting directly the outer to the inner eggshell surfaces. Such pore spatial arrangement and geometry would enhance, as the eggshell thins during incubation, a greater G(H2O), G(O2) and G(CO2) and facilitate embryonic development in high moisture nesting contents. Overall, data suggests that neosauropod nesting and brooding behaviors were dependent on elevated moisture nesting environments.
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. Children with haemophilia often bleed inside joints and muscles, which may impair postural adjustments. These postural adjustments are necessary to control postural balance during daily activities. The inability to quickly recover postural balance could elevate the risk of bleeding. To determine whether children with haemophilia have impaired postural adjustment after an unexpected perturbation compared with healthy children. Twenty children with haemophilia comprised the haemophilic group (HG), and 20 healthy, age-paired children comprised the control group (CG). Subjects stood on a force plate, and 4% of the subjects body weight was applied via a pulley system to a belt around the subjects trunks. The centre of pressure (COP) displacement was measured after the weight was unexpectedly released to produce a controlled postural perturbation followed by postural adjustment to recover balance. The subjects postural adjustments in eight subsequent intervals of 1 s (t1t8), beginning with the moment of weight removal, were compared among intervals and between groups. The applied perturbation magnitudes were the same for both groups, and no difference was observed between the groups in t1. However, the COP displacement in t2 in the HG was significantly higher than in the CG. No differences were observed between the groups in the other intervals. Within-group analysis showed that the COP was higher in t2 than in t4 (P = 0.016), t5 (P = 0.001) and t8 (P = 0.050) in the HG. No differences were observed among intervals in the CG. Children with haemophilia demonstrated differences in postural adjustment while undergoing unexpected balance perturbations when compared with healthily children.