33 research outputs found

    Universality and scaling study of the critical behavior of the two-dimensional Blume-Capel model in short-time dynamics

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    In this paper we study the short-time behavior of the Blume-Capel model at the tricritical point as well as along the second order critical line. Dynamic and static exponents are estimated by exploring scaling relations for the magnetization and its moments at early stage of the dynamic evolution. Our estimates for the dynamic exponents, at the tricritical point, are z=2.215(2)z= 2.215(2) and θ=0.53(2)\theta= -0.53(2).Comment: 12 pages, 9 figure

    Biochemical and bioactive phytonutrients changes in tissues of two cultivars of fresh-cut cassava in stick form under refrigerated storage

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    The aim of this study was to evaluate the effects of fresh-cut in stick form of two cassava cultivars on their biochemical and antioxidant characteristics, at two harvest times. The fresh cut cassava sticks were packaged in polypropylene, maintained at 5±1ºC, with 90±5% relative humidity for 12 days. The concentration of carotenoids, total soluble phenolic compounds and the activity of phenylalanine ammonia lyase and antioxidant capacity were significantly higher for the sticks of cultivar 'Amarela' cassava than for the sticks of cultivar 'Cacau'. The concentrations of carotenoids, total soluble phenolic compounds, and the activity of phenylalanine ammonia lyase and antioxidant capacity were all significantly greater when harvested at 14-month of age. There was a significant increase in the activity of phenylalanine ammonia lyase during the 12 days of storage at 5ºC. However, there was a decrease in total carotenoids, soluble phenolic compounds, and in the antioxidant capacity of the two cultivars

    Habitat structure and small mammals abundances in one semiarid landscape in the Brazilian Caatinga

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    Studies conducted under a major project sponsored by the Brazilian Academy of Sciences in the 1970's concluded that the small mammal fauna of the semiarid Caatinga region of Brazil is impoverished and highly restricted to mesic granite outcroppings due to the lack of water conserving physiological capabilities in its species. This work focuses the abundance of small mammals in five typical Caatinga habitats. Indirect gradient analysis shows that three theoretical environmental variables explain most of the variance present in the community abundance matrix. Direct analysis of gradients show that none of these variables is highly correlated to availability of granite outcroppings. Our data also suggest that the abundances in Caatinga are not particularly low when compared to neighbor biomes and that underlying factors of habitat use by Caatinga small mammals are more complex than previously supposed.<br>Estudos realizados dentro de um grande projeto financiado pela Academia Brasileira de Ciências na década de 1970 concluíram que a fauna de pequenos mamíferos da região semiárida da Caatinga do Brasil é empobrecida e altamente restrita a afloramentos graníticos mésicos devido à falta de capacidades fisiológicas para a conservação de água das suas espécies. Este trabalho enfoca a abundância de pequenos mamíferos em cinco habitats típicos da Caatinga. A análise indireta de gradiente mostra que três variáveis ambientais teóricas explicam a maior parte da variância presente na matriz de abundâncias da comunidade. A análise direta de gradiente mostra que nenhuma dessas variáveis está altamente correlacionada à disponibilidade de afloramentos graníticos. Nossos dados também sugerem que a abundância na Caatinga não é particularmente baixa quando comparada a biomas vizinhos e que os fatores subjacentes ao uso do habitat pelos pequenos mamíferos da Caatinga é mais complexo do que previamente suposto

    Ice core chemistry database: an Antarctic compilation of sodium and sulfate records spanning the past 2000 years

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    Changes in sea ice conditions and atmospheric circulation over the Southern Ocean play an important role in modulating Antarctic climate. However, observations of both sea ice and wind conditions are limited in Antarctica and the Southern Ocean, both temporally and spatially, prior to the satellite era (1970 onwards). Ice core chemistry data can be used to reconstruct changes over annual, decadal, and millennial timescales. To facilitate sea ice and wind reconstructions, the CLIVASH2k (CLimate Variability in Antarctica and the Southern Hemisphere over the past 2000 years) working group has compiled a database of two species, sodium [Na+] and sulfate [SO2− 4 ], commonly measured ionic species. The database (https://doi.org/10.5285/9E0ED16E-F2AB4372-8DF3-FDE7E388C9A7; Thomas et al., 2022) comprises records from 105 Antarctic ice cores, containing records with a maximum age duration of 2000 years. An initial filter has been applied, based on evaluation against sea ice concentration, geopotential height (500 hPa), and surface wind fields to identify sites suitable for reconstructing past sea ice conditions, wind strength, or atmospheric circulation
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