994 resultados para 1599-1660


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

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The purpose of the present paper is to study some properties of solutions of Volterra integral equations on time scales. We generalize to a time scale some known properties concerning continuity and convergence of solutions from the continuous case.

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Digital models are an alternative for carrying out analyses and devising treatment plans in orthodontics. The objective of this study was to evaluate the accuracy and the reproducibility of measurements of tooth sizes, interdental distances and analyses of occlusion using plaster models and their digital images. Thirty pairs of plaster models were chosen at random, and the digital images of each plaster model were obtained using a laser scanner (3Shape R-700, 3Shape A/S). With the plaster models, the measurements were taken using a caliper (Mitutoyo Digimatic(®), Mitutoyo (UK) Ltd) and the MicroScribe (MS) 3DX (Immersion, San Jose, Calif). For the digital images, the measurement tools used were those from the O3d software (Widialabs, Brazil). The data obtained were compared statistically using the Dahlberg formula, analysis of variance and the Tukey test (p < 0.05). The majority of the measurements, obtained using the caliper and O3d were identical, and both were significantly different from those obtained using the MS. Intra-examiner agreement was lowest when using the MS. The results demonstrated that the accuracy and reproducibility of the tooth measurements and analyses from the plaster models using the caliper and from the digital models using O3d software were identical.

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

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Reservoirs are artificial environments built by humans, and the impacts of these environments are not completely known. Retention time and high nutrient availability in the water increases the eutrophic level. Eutrophication is directly correlated to primary productivity by phytoplankton. These organisms have an important role in the environment. However, high concentrations of determined species can lead to public health problems. Species of cyanobacteria produce toxins that in determined concentrations can cause serious diseases in the liver and nervous system, which could lead to death. Phytoplankton has photoactive pigments that can be used to identify these toxins. Thus, remote sensing data is a viable alternative for mapping these pigments, and consequently, the trophic. Chlorophyll-a (Chl-a) is present in all phytoplankton species. Therefore, the aim of this work was to evaluate the performance of images of the sensor Operational Land Imager (OLI) onboard the Landsat-8 satellite in determining Chl-a concentrations and estimating the trophic level in a tropical reservoir. Empirical models were fitted using data from two field surveys conducted in May and October 2014 (Austral Autumn and Austral Spring, respectively). Models were applied in a temporal series of OLI images from May 2013 to October 2014. The estimated Chl-a concentration was used to classify the trophic level from a trophic state index that adopted the concentration of this pigment-like parameter. The models of Chl-a concentration showed reasonable results, but their performance was likely impaired by the atmospheric correction. Consequently, the trophic level classification also did not obtain better results.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Objective: To evaluate the perception and attitude of kindergarten teachers in relation to the storage of toothbrushes. Methodology: The analysis instrument used was a structured and previously validated questionnaire. The sample universe of this study was composed of all states and municipals kindergarten school teachers who taught in school year of 2010 at the town of Araçatuba / SP (n = 232). The criteria used to integrate the study were: to have a college degree and agree to participate. Results: 164 teachers participated of the study. The results were analyzed using Epi Info 6.04 and showed that 55% of the teachers had received some information about the proper storage of toothbrushes, and only 35% believed that the toothbrushes were storaged improperly. Most teachers, 97% reported being possible the transmission of microorganisms through the brush, however, there was observed difficulty in identifying which diseases could be transmitted. About the question related to the execute of supervised toothbrushing, 93% of the educators said that they realize supervised toothbrushing and the same percentage was observed for the identification of preschoolers at the toothbrushes. Conclusions: The perception and attitude of the teachers ahead the storage of toothbrushes are weak and limited, so there is a need for educational programs targeted to this group, so that they would have more information and knowledge related to the correct storage of toothbrushes and would continue to perform oral health preventive methods.

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As demonstrações experimentais são atividades de grande tradição na História da Ciência, sendo realizadas desde 1660 na Royal Society, por grandes expoentes da Física, com o objetivo de promover a divulgação dos conhecimentos científicos desenvolvidos.Com o objetivo de contribuir com a melhoria e o interesse dos alunos pelos estudos das Ciências Exatas, bem como a conscientização destes sobre conceitos relacionados à Energia e seu impacto sobre a sociedade e sobre o meio ambiente, temos realizado atividades de demonstrações experimentais, denominadas de “Show de Energia”, nas escolas públicas de Ensino Médio de cidades da Região de Guaratinguetá, interior do Estado de São Paulo. Em cada um dos shows realizados entrevistamos os alunos, através de um questionário estruturado, buscando avaliar o impacto dessa atividade na motivação dos estudantes para o aprendizado de conceitos científicos. Os resultados apontam para a grande influência que a realização dos shows tem exercido sobre a motivação dos estudantes.

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Pós-graduação em Letras - FCLAS

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Pós-graduação em Letras - FCLAS

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Laurencia dendroidea shows high inter- and intrapopulation variability in the amount of the sesquiterpene elatol, caused by genetic variation as well as environmental factors. To test the independent effect of physical and nutritional conditions, the growth and the levels of elatol in L. dendroidea clones were evaluated under different conditions of temperature, salinity, irradiance, and culture medium in the laboratory. Growth of L. dendroidea was clearly affected by all these factors, but elatol levels were influenced only by temperature and salinity. Better conditions for growth did not produce a similar effect on elatol production in L. dendroidea, contradicting the carbon/nutrient balance and growth/differentiation balance models. On the contrary, severe conditions of temperature and salinity promoted a decrease in elatol levels, as predicted by the environmental stress model. Our results using clones indicated that abiotic factors clearly take part in fostering chemical variations observed in natural populations, in addition to genetic factors, and can promote differential susceptibility of plant specimens to natural enemies.

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Aim. The purpose of this study was to provide normal values for maximum phonation time (MPT) and the s/z ratio by examining 1660 children aged 4-12 years and without vocal signs or symptoms. Methods. The technique was based on the sustained emission of the /a/ vowel and fricatives /s/ and /z/. Results. The average of the MPT in children of the different age groups was as follows: 6.09 seconds for the age group 4-6 years (males, 5.97; female, 6.21 seconds), 7.94 seconds for the age group 7-9 years (males, 8.07; females, 7.79 seconds), and 8.98 for the age group 10-12 years (males, 9.05; females, 8.92 seconds). The overall average for males was 7.78 and females 7.64 seconds. The s/z ratio was near 1.0 in most children but above 1.2 in 133 children and below 0.8 in 133 children. Conclusion. These values of MPT and s/z ratio can be used as normative in further pediatric studies.

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A hybrid material with excellent mechanical and biological properties is produced by electrospinning a co-solution of PET and collagen. The fibers are mapped using SEM, confocal Raman microscopy and collagenase digestion assays. Fibers of different compositions and morphologies are intermingled within the same membrane, resulting in a heterogeneous scaffold. The collagen distribution and exposure are found to depend on the PET/collagen ratio. The materials are chemically and mechanically characterized and biologically tested with fibroblasts (3T3-L1) and a HUVEC culture in vitro. All of the hybrid scaffolds show better cell attachment and proliferation than PET. These materials are potential candidates to be used as vascular grafts.

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The present study reports the identification of two new staurosporine derivatives, 2-hydroxy-7-oxostaurosporine (1) and 3-hydroxy-7-oxostaurosporine (2), obtained from mid-polar fractions of an aqueous methanol extract of the tunicate Eudistoma vannamei, endemic to the northeast coast of Brazil. The mixture of 1 and 2 displayed IC50 values in the nM range and was up to 14 times more cytotoxic than staurosporine across a panel of tumor cell lines, as evaluated using the MTT assay.