3,850 research outputs found

    Generating and Revealing a Quantum Superposition of Electromagnetic Field Binomial States in a Cavity

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    We introduce the NN-photon quantum superposition of two orthogonal generalized binomial states of electromagnetic field. We then propose, using resonant atom-cavity interactions, non-conditional schemes to generate and reveal such a quantum superposition for the two-photon case in a single-mode high-QQ cavity. We finally discuss the implementation of the proposed schemes.Comment: 4 pages, 3 figures. Title changed (published version

    Temporal dynamics of the shrub and herbaceous layer of an area of moist grassland in Alto Paraíso de Goiás, Brazil

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    Este trabalho avaliou a dinâmica estrutural e fl orística de uma comunidade de espécies herbáceo-arbustivas de uma área de campo limpo úmido em Alto Paraíso de Goiás, o primeiro inventário realizado em 2000 (T0) e o segundo em 2007 (T1). A diversidade de Shannon entre os períodos foi comparada pelo teste-t de Hutcheson e a similaridade fl orística, pelo índice de similaridade de Chao-Sørensen. As relações fl orísticas e a cobertura, entre os períodos e as linhas, foram avaliadas por meio de análises de correspondência retifi cada (DCA). Foram amostradas 98 espécies, 88 no T0 e 67 no T1, sendo 31 exclusivas do T0 e 10 do T1. A diversidade fl orística na comunidade foi elevada nos dois períodos, porém diferente entre esses (t = 7,12; p < 0,001), devido a variação no número e cobertura das espécies. A similaridade entre os dois inventários foi alta (Chao-Sørensen ± IC = 0,841 ± 0,074). A ordenação por DCA indicou relações entre a composição fl orística e a cobertura com o gradiente de umidade e de matéria orgânica no solo identifi cados em T0. Houve modifi cações nas linhas em zonas sazonais, as quais se tornaram mais semelhantes às linhas constantemente saturadas por água. Em um intervalo de sete anos o campo limpo úmido apresentou mudanças na composição fl orística e, principalmente na estrutura devido o aumento da cobertura de espécies perenes, cespitosas e entouceiradas, que foram favorecidas pela maior umidade no solo em resposta à elevação da pluviosidade da região. __________________________________________________________________________________________ ABSTRACTTh is study evaluated the fl oristic and structural dynamics of a community of herbaceous-shrub species in an area of moist grassland in Alto Paraíso de Goiás. Th e fi rst inventory was undertaken in 2000 (T0) and the second in 2007 (T1). Shannon’s diversity between the periods was compared by Hutchesons´s t-test, and the fl oristic similarity by the Chao-Sørensen similarity index. Floristic composition and cover, between periods and lines, were evaluated by detrended correspondence analysis (DCA). We sampled 98 species, 88 at T0 and 67 at T1; 31 were unique to T0 and 10 to T1. Floristic diversity in the community was high in both periods, but diff erent between them (t = 7.12, p <0.001), due to variation in species number and coverage. Similarity between the two surveys was high (Chao-Sørensen CI = ± 0.841 ± 0.074). Th e DCA ordination indicated relationships between the fl oristic composition and cover with a gradient of moisture and organic matter in the soil identifi ed in T0. Th ere were changes in the lines in the seasonal zones, which became more similar in those constantly saturated with water. During an interval of seven years the moist grassland showed changes in fl oristic composition and mainly in structure due to increased cover of the clumped tussock perennial species, which were favored by higher soil moisture due to high rainfall in the region

    Estimativa da evapotranspiração de referência no Brasil: uma análise crítica.

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    RESUMO: Devido a necessidade de quantificar a perda de água pelas grandes culturas, diversos trabalhos tem sido desenvolvidos com o objetivo de encontrar um modelo de estimativa da evapotranspiração de referência (ETo) para uma região específica. Assim, o presente trabalho tem como objetivo analisar a produção científica brasileira na área de estimativa da evapotranspiração e identificando os principais métodos de estimativa da ETo utilizados para as diferentes condições climáticas brasileiras. Para isso, realizou-se uma revisão de bibliográfica de trabalhos de estimativa de ETo realizados no Brasil. Entre os 38 trabalhos encontrados para a presente discussão, foi possível concluir que os métodos mais adequados foram os métodos de Blaney-Criddle FAO-24 e Radiação Solar FAO-24 para o norte e nordeste, e Thornthwaite e Camargo para o sul e sudeste, onde as regiões norte, centro-oeste e sul necessitam de maiores estudos nesta área

    Risk factors associated with Toxoplasma gondii infection in dairy cattle, State of Rio de Janeiro.

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    Toxoplasmosis is one of the most common parasitic zoonoses throughout the world. Infection in man and animals varies in different geographical areas influenced by many environmental conditions. Seroprevalence of Toxoplasma gondii infection in cattle in Brazil ranges from 1.03 to 71%. A cross-sectional survey was carried out in 58 out of 453 farms in the South Fluminense Paraiba Valley, State of Rio de Janeiro, Brazil. Over 3-year-old cattle (n=589) from dairy herds were selected for blood collection and detection of anti-T. gondii antibodies by indirect immunofluorescence reaction (IFA) with initial titration of 1:16; titers ? 64 were considered positive. Univariate analysis of risk factors showed that cats in contact with cattle, cats in contact with drinking water, and number of cats were associated with T. gondii seroprevalence. Logistic regression revealed a two-fold increased risk for infection of cattle (p=0.0138) through larger number of cats (>3) compared with low numbers of cats (1-2) on the farm. In contrast, the presence of chickens was considered a protective factor (p=0.025). Toxoplasmose é uma das mais comuns zoonoses parasitárias do mundo. Infecções em seres humanos e em animais variam nas diferentes áreas geográficas influenciadas pelas condições ambientais. A soroprevalência da infecção por Toxoplasma gondii em bovinos no Brasil varia de 1,03 a 71,0%. O estudo transversal foi realizado em 58 de um total de 453 propriedades na região Sul Fluminense do estado do Rio de Janeiro. Vacas leiteiras acima de 3 anos de idade (n=589) foram selecionadas para coleta de sangue e a detecção de anticorpos anti-T. gondii foi feita pelo teste de imunofluorescência indireta (IFI) com titulação inicial de 1:16 e títulos ? 64 foram considerados positivos. Após análise univariada dos fatores de risco, gatos em contato com bovinos, em contato com a água de beber dos animais e o número de gatos foram associados com a soroprevalência de T. gondii. A regressão logística demonstrou que o número maior de gatos (>3) teve um risco duas vezes maior (p=0,0138) que propriedades que tinham um número menor de gatos (1-2). Em contraste, a presença de galinhas foi considerada um fator de proteção (p=0,025)

    The impact of knowledge about diabetes, resilience and depression on glycemic control: a cross-sectional study among adolescents and young adults with type 1 diabetes

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    Background: the purpose of this study is to evaluate the relationship between glycemic control and the factors of knowledge about diabetes, resilience, depression and anxiety among Brazilian adolescents and young adults with type 1 diabetes.Methods: This cross-sectional study included 85 adolescents and young adults with type 1 diabetes, aged between 11-22 years, with an average age of 17.7 +/- 3.72 years. Glycemic control degree was evaluated through HbA1c. To assess psychosocial factors, the following questionnaires were used: resilience (Resilience Scale, RS) and anxiety and depression (Hospital Anxiety and Depression Scale, HADS). the Diabetes Knowledge Assessment Scale (DKNA) was used to assess knowledge about diabetes.Results: Significant correlations were found between HbA1c and resilience, anxiety and depression. Multiple linear regression analysis revealed that the only variable which presented significant association with the value of HbA1c was depression.Conclusions: Depression has a significant association with higher HbA1c levels, as demonstrated in a regression analysis. the results suggest that depression, anxiety and resilience should be considered in the design of a multidisciplinary approach to type 1 diabetes, as these factors were significantly correlated with glycemic control. Glycemic control was not correlated with knowledge of diabetes, suggesting that theoretical or practical understanding of this disease is not by itself significantly associated with appropriate glycemic control (HbA1c <= 7.5%).Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Diabetes Center, Universidade Federal de São PauloUniversidade Federal de São Paulo, Dept Hlth Informat, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Div Endocrinol, Dept Med, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Hlth Informat, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Div Endocrinol, Dept Med, BR-04023062 São Paulo, BrazilWeb of Scienc

    Study of 9Be+12C elastic scattering at energies near the Coulomb barrier

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    In this work, angular distribution measurements for the elastic channel were performed for the 9Be+12C reaction at the energies ELab=13.0, 14.5, 17.3, 19.0 and 21.0 MeV, near the Coulomb barrier. The data have been analyzed in the framework of the double folding S\~ao Paulo potential. The experimental elastic scattering angular distributions were well described by the optical potential at forward angles for all measured energies. However, for the three highest energies, an enhancement was observed for intermediate and backward angles. This can be explained by the elastic transfer mechanism. Keywords: 9Be+12C, Elastic Scattering, S\~aoo Paulo Potential

    6Li direct breakup lifetimes

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    alpha-d coincidence data were studied for the 6Li + 59Co reaction at E(lab) = 29.6 MeV. By using a kinematic analysis, it was possible to identify which process, leading to the same final state, has the major contribution for each of the selected angular regions. Contributions of the 6Li sequential and direct breakup to the incomplete fusion/transfer process were discussed by considering the lifetimes obtained by using a semiclassical approach, for both breakup components.Comment: 5 pages, 4 figures, Invited Talk (Parrallel Sessions) of A. Szanto de Toledo, prepared for the Proccedings of the 10th International Conference on Nucleus-Nucleus Collisions, August 16-21, 2009, Beijing, China; submitted to Nucl. Phys. A (Proceedings of NN2009
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