5,157 research outputs found

    Entrance-channel Mass-asymmetry Dependence of Compound-nucleus Formation Time in Light Heavy-ion Reactions

    Get PDF
    The entrance-channel mass-asymmetry dependence of the compound nucleus formation time in light heavy-ion reactions has been investigated within the framework of semiclassical dissipative collision models. the model calculations have been succesfully applied to the formation of the 38^{38}Ar compound nucleus as populated via the 9^{9}Be+29^{29}Si, 11^{11}B+27^{27}Al, 12^{12}C+26^{26}Mg and 19^{19}F+19^{19}F entrance channels. The shape evolution of several other light composite systems appears to be consistent with the so-called "Fusion Inhibition Factor" which has been experimentally observed. As found previously in more massive systems for the fusion-evaporation process, the entrance-channel mass-asymmetry degree of freedom appears to determine the competition between the different mechanisms as well as the time scales involved.Comment: 12 pages, 3 Figures available upon request, Submitted at Phys. Rev.

    Espacialização da pecuária de corte sul-mato-grossense.

    Get PDF
    A economia do Estado de Mato Grosso do Sul baseia-se principalmente na agricultura e pecuária, e o estado é subdivido em quatro mesorregiões: Centro-Norte, Pantanal, Sudoeste e Leste. Para espacializar a produção da pecuária bovina sul-mato-grossense, foram usados dados censitários e geocódigos municipais do IBGE e procedimentos do sistema de informação geográfica (SIG). As mesorregiões Leste e Sudoeste comportam o maior número de cabeças, da ordem de seis milhões. A mesorregião do Pantanal possui imensas áreas alagadas e favorece a exploração extensiva, e a mesorregião Centro-Norte, localizada mais próxima aos grandes mercados consumidores, têm cerca de quatro milhões de cabeças. A taxa geométrica de crescimento (TGC) do rebanho bovino de 2006 a 2011 apresenta padrão irregular, com variação de -6,86 a +7,31, -5,60 a +13,33, -2,65 a +6,65 e -5,15 a +2,45 para as regiões Pantanal, Centro-Norte, Sudoeste e Leste, respectivamente. Em termos nacionais, as projeções da TGC (2007 a 2023) para consumo e exportação são da ordem de 30% e 22,4%, respectivamente, enquanto a TGC para produção nesse mesmo período é da ordem de 18,4%. Esses números representam menos oferta interna e potencial aquecimento dos preços domésticos, contribuindo, assim, para um possível aumento da taxa de inflação no período analisado

    Silicon leaf application and physiological quality of white oat and wheat seeds.

    Get PDF
    Plant nutrition can positively influence quality of seeds by improving plant tolerance to adverse climate. In this context, silicon is currently considered a icronutrient and it is beneficial to plant growth, especially Poaceaes such as white oat and wheat, thereby improving physiological quality of seeds. This study had the objective of evaluating the effects of silicon leaf application on plant tillering, silicon levels and physiological quality of white oat and wheat seeds besides establishing correlations between them. Two experiments were carried out in winter with white oat and wheat. The experimental design was the completely randomized block with eight replications. Treatments consisted of foliar application of silicon (0.8% of soluble silicon, as stabilized orthosilicic acid) and a control (with no application). Silicon levels in leaves were determined at flowering whereas the number of plants and panicles/spikes per area was counted right before harvest. Seed quality was evaluated right after harvest through mass, germination and vigor tests. Data was submitted to variance analysis and means were compared by the Tukey test at a probability level of 5%. Person?s linear correlation test was performed among silicon level in plants, tillering and seed quality data. Silicon leaf application increases root and total length of white oat seedlings as an effect of higher Si level in leaves. Silicon leaf application increases mass of wheat seeds without affecting germination or vigor

    Effects of Dry Matter Content and Microbial Additive on Tifton 85 \u3ci\u3e(Cynodon dactylon ssp.)\u3c/i\u3e Wilted Silage Fermentation Parameters

    Get PDF
    The objective of this study was to evaluate the wilting and the addition of a bacterial-enzymatic additive effects on the fermentation parameters of Tifton 85 (Cynodon dactylon spp.) silage. Forage was stored as 326 kg bales wrapped with a plastic film. Treatments consisted of 5 forage dry matter levels (20-30%, 30-40%, 40-50%, 50 -60% e 60 a 70%) without additive and 3 dry matter levels (20-30%, 40-50%, e 60-70%) with additive. Buffered propionic acid solution was sprayed onto 60-70% dry matter bales, prior to wrapping, determining an additional treatment. Core samples were taken at 0, 6, 12 hours and 1, 2, 4, 8, 16, and 32 days after wrapping to establish silage pH and temperature trends. Field dry matter losses during the baling process were also evaluated. Bale weight with no additive decreased (364 kg to 254 kg) with increased forage DM content, which in turn resulted in lower bale bulk density (310 to 216 kg/m3 ). Lower field DM losses (281 to 177 kg/ha) were associated with higher forage DM content. Final silage pH and temperature peaks were increased at higher DM content, whereas the presence of microbial additive prevented temperature surge

    Neuroprotective effects of EpoL against oxidative stress induced by soluble oligomers of Aβ peptide

    Full text link
    Erythropoietin is a glycoproteic hormone that regulates hematopoiesis by acting on its specific receptor (EpoR). The expression of EpoR in the central nervous system (CNS) suggests a role for this hormone in the brain. Recently, we developed a new Epo variant without hematopoietic activity called EpoL, which showed marked neuroprotective effects against oxidative stress in brain ischemia related models. In this study, we have evaluated the neuroprotective effects of EpoL against oxidative stress induced by chronic treatment with Aβ. Our results show that EpoL was neuroprotective against Aβ-induced toxicity by a mechanism that implicates EpoR, reduction in reactive oxygen species, and reduction in astrogliosis. Furthermore, EpoL treatment improved calcium handling and SV2 levels. Interestingly, the neuroprotective effect of EpoL against oxidative stress induced by chronic Aβ treatment was achieved at a concentration 10 times lower than that of Epo. In conclusion, EpoL, a new variant of Epo without hematopoietic activity, is of potential interest for the treatment of diseases related to oxidative stress in the CNS such as Alzheimer disease.Grant Innova-Corfo “13IDL2-18688”; Conicyt Grant “Beca Doctorado Nacional no. 21130386”; Fondecyt Grant “1161078
    corecore