88 research outputs found

    Ciclagem de nutrientes por plantas de cobertura no cerrado.

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    O objetivo deste trabalho foi avaliar o desempenho de plantas cultivadas quanto ao acúmulo e a liberação de nutrientes, durante o período de entressafra, em um Latossolo Vermelho distroférrico de Santo Antônio de Goiás, GO e Rio Verde, GO. O delineamento experimental foi o de blocos casualizados, em esquema de parcelas subdivididas no tempo, com as plantas de cobertura avaliadas nas parcelas, e nas subparcelas, as épocas de coleta de fitomassa, com quatro repetições

    Development and validation of a reversed phase HPLC method for determination of anacardic acids in cashew (Anacardium occidentale) nut shell liquid.

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    Made available in DSpace on 2018-06-07T01:06:04Z (GMT). No. of bitstreams: 1 ART18024.pdf: 390822 bytes, checksum: 8135c0ccd5a968594df8c945290d6aa6 (MD5) Previous issue date: 2018-06-04bitstream/item/178250/1/ART18024.pd

    Produção de fitomassa por plantas de cobertura no cerrado.

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    O objetivo do trabalho foi avaliar a produção de fitomassa por plantas de cobertura semeadas em safrinha no desempenho do arroz de terras altas e soja, semeada em rotação, em sistema de plantio direto e preparo convencional, em Latossolo Vermelho do município de Rio Verde, Goiás. O trabalho foi realizado no período de abril de 2008 a fevereiro de 2009. Utilizou-se o delineamento em faixas, em esquema de parcelas subdivididas no tempo, com quatro repetições. Nas faixas horizontais foram testadas as plantas de cobertura, nas faixas verticais dois sistemas de manejo (plantio direto e convencional, ambos com três anos de implantação), e nas subparcelas seis épocas de coletas de fitomassa após a dessecação das plantas de cobertura, que ocorreu aos 0 , 15, 30, 60, 90 e 120 dias à partir da dessecação de manejo das plantas de cobertura, com quatro repetições

    The Critical Behaviour of the Spin-3/2 Blume-Capel Model in Two Dimensions

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    The phase diagram of the spin-3/2 Blume-Capel model in two dimensions is explored by conventional finite-size scaling, conformal invariance and Monte Carlo simulations. The model in its τ\tau-continuum Hamiltonian version is also considered and compared with others spin-3/2 quantum chains. Our results indicate that differently from the standard spin-1 Blume-Capel model there is no multicritical point along the order-disorder transition line. This is in qualitative agreement with mean field prediction but in disagreement with previous approximate renormalization group calculations. We also presented new results for the spin-1 Blume-Capel model.Comment: latex 18 pages, 4 figure

    Acute TNFα levels predict cognitive impairment 6-9 months after COVID-19 infection.

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    A neurocognitive phenotype of post-COVID-19 infection has recently been described that is characterized by a lack of awareness of memory impairment (i.e., anosognosia), altered functional connectivity in the brain's default mode and limbic networks, and an elevated monocyte count. However, the relationship between these cognitive and brain functional connectivity alterations in the chronic phase with the level of cytokines during the acute phase has yet to be identified. Determine whether acute cytokine type and levels is associated with anosognosia and functional patterns of brain connectivity 6-9 months after infection. We analyzed the predictive value of the concentration of acute cytokines (IL-1RA, IL-1β, IL-6, IL-8, IFNγ, G-CSF, GM-CSF) (cytokine panel by multiplex immunoassay) in the plasma of 39 patients (mean age 59 yrs, 38-78) in relation to their anosognosia scores for memory deficits via stepwise linear regression. Then, associations between the different cytokines and brain functional connectivity patterns were analyzed by MRI and multivariate partial least squares correlations for the whole group. Stepwise regression modeling allowed us to show that acute TNFα levels predicted (R <sup>2</sup> = 0.145; β = -0.38; p = .017) and were associated (r = -0.587; p < .001) with scores of anosognosia for memory deficits observed 6-9 months post-infection. Finally, high TNFα levels were associated with hippocampal, temporal pole, accumbens nucleus, amygdala, and cerebellum connectivity. Increased plasma TNFα levels in the acute phase of COVID-19 predict the presence of long-term anosognosia scores and changes in limbic system functional connectivity

    Brain functional connectivity alterations associated with neuropsychological performance 6-9 months following SARS-CoV-2 infection.

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    Neuropsychological deficits and brain damage following SARS-CoV-2 infection are not well understood. Then, 116 patients, with either severe, moderate, or mild disease in the acute phase underwent neuropsychological and olfactory tests, as well as completed psychiatric and respiratory questionnaires at 223 ± 42 days postinfection. Additionally, a subgroup of 50 patients underwent functional magnetic resonance imaging. Patients in the severe group displayed poorer verbal episodic memory performances, and moderate patients had reduced mental flexibility. Neuroimaging revealed patterns of hypofunctional and hyperfunctional connectivities in severe patients, while only hyperconnectivity patterns were observed for moderate. The default mode, somatosensory, dorsal attention, subcortical, and cerebellar networks were implicated. Partial least squares correlations analysis confirmed specific association between memory, executive functions performances and brain functional connectivity. The severity of the infection in the acute phase is a predictor of neuropsychological performance 6-9 months following SARS-CoV-2 infection. SARS-CoV-2 infection causes long-term memory and executive dysfunctions, related to large-scale functional brain connectivity alterations

    Land-use change and carbon stocks: regional assessment of sugarcane areas in Brazil.

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    Abstract: In agricultural product Life Cycle Assessment (LCA), emissions or removals of carbon (C) from land-use change can highly affect the global warming. The aim of this study was to evaluate the impacts of biomass C values and stock change factors on land use change (LUC) emissions in areas of sugarcane expansion in Brazil. In this study, we used stratified random sample in order to estimate changes in land cover through geotechnologies and associated C stocks from literature data. For that, the total area was stratified by three criteria: soil type, % of native vegetation in 1998 and age of sugarcane plantation in 2018. The sample size represented 12.8% of the studied area (172,000 ha). To this end, a matrix of primary combinations was combined with spatial data such as land cover in 1998, soil types, biomes and Köppen climate classification. Estimates of C stock changes in soil and biomass were calculated the Stock-Difference Method, according to IPCC Guidelines and specialized literature. Respecting the uncertainties, this approach allowed to have an estimate of C balance in sugarcane fields at the regional level in Brazil. Three main recommendations: (i) values of FMG> 1.0 (FMG, stock change factor for management regime), should be used for sugarcane, but future research ratification is necessary; (ii) biomass C values of sugarcane biomass above 5 tonnes C ha-1 should be used, especially when sugarcane is harvested without burning; and (iii) as there is still no relationship between level of pasture degradation and C content in soil, biomass C values and pasture FMG should be carefully chosen in pasture conversion to sugarcane
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