515 research outputs found

    Exercise inhibits the effects of smoke-induced COPD involving modulation of STAT3

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    Purpose . Evaluate the participation of STAT3 in the e ff ects of aerobic exercise (AE) in a model of smoke-induced COPD. Methods . C57Bl/6 male mice were divided into control, Exe, COPD, and COPD+Exe groups. Smoke were administered during 90 days. Treadmill aerobic training begun on day 61 until day 90. Pulmonary in fl ammation, systemic in fl ammation, the level of lung emphysema, and the airway remodeling were evaluated. Analysis of integral and phosphorylated expression of STAT3 by airway epithelial cells, peribronchial leukocytes, and parenchymal leukocytes was performed. Results . AE inhibited smoke-induced accumulation of total cells ( p <0 001 ), lymphocytes ( p <0 001 ), and neutrophils ( p <0 001 ) in BAL, as well as BAL levels of IL- 1 β ( p <0 001 ), CXCL1 ( p <0 001 ), IL-17 ( p <0 001 ), and TNF- α ( p <0 05 ), while increased the levels of IL-10 ( p <0 001 ). AE also inhibited smoke-induced increases in total leukocytes ( p <0 001 ), neutrophils ( p <0 05 ), lymphocytes ( p <0 001 ), and monocytes ( p <0 01 ) in blood, as well as serum levels of IL-1 β ( p <0 01 ), CXCL1 ( p <0 01 ), IL-17 ( p <0 05 ), and TNF- α ( p <0 01 ), while increased the levels of IL-10 ( p <0 001 ). AE reduced smoke-induced emphysema ( p <0 001 ) and collagen fi ber accumulation in the airways ( p <0 001 ). AE reduced smoke-induced STAT3 and phospho-STAT3 expression in airway epithelial cells ( p <0 001 ), peribronchial leukocytes ( p <0 001 ), and parenchymal leukocytes ( p <0 001 ). Conclusions .AE reduces smoke-induced COPD phenotype involving STAT3

    Soil pyrogenic carbon in southern Amazonia: Interaction between soil, climate, and above-ground biomass

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    This is the final version. Available on open access from Frontiers Media via the DOI in this recordData availability statement: The original contributions presented in this study are included in the article/Supplementary material, further inquiries can be directed to the corresponding author/s.The Amazon forest represents one of the world’s largest terrestrial carbon reservoirs. Here, we evaluated the role of soil texture, climate, vegetation, and distance to savanna on the distribution and stocks of soil pyrogenic carbon (PyC) in intact forests with no history of recent fire spanning the southern Amazonia forest-Cerrado Zone of Transition (ZOT). In 19 one hectare forest plots, including three Amazonian Dark Earth (ADE, terra preta) sites with high soil PyC, we measured all trees and lianas with diameter ≥ 10 cm and analyzed soil physicochemical properties, including texture and PyC stocks. We quantified PyC stocks as a proportion of total organic carbon using hydrogen pyrolysis. We used multiple linear regression and variance partitioning to determine which variables best explain soil PyC variation. For all forests combined, soil PyC stocks ranged between 0.9 and 6.8 Mg/ha to 30 cm depth (mean 2.3 ± 1.5 Mg/ha) and PyC, on average, represented 4.3% of the total soil organic carbon (SOC). The most parsimonious model (based on AICc) included soil clay content and above-ground biomass (AGB) as the main predictors, explaining 71% of soil PyC variation. After removal of the ADE plots, PyC stocks ranged between 0.9 and 3.8 Mg/ha (mean 1.9 ± 0.8 Mg/ha–1) and PyC continued to represent ∼4% of the total SOC. The most parsimonious models without ADE included AGB and sand as the best predictors, with sand and PyC having an inverse relationship, and sand explaining 65% of the soil PyC variation. Partial regression analysis did not identify any of the components (climatic, environmental, and edaphic), pure or shared, as important in explaining soil PyC variation with or without ADE plots. We observed a substantial amount of soil PyC, even excluding ADE forests; however, contrary to expectations, soil PyC stocks were not higher nearer to the fire-dependent Cerrado than more humid regions of Amazonia. Our findings that soil texture and AGB explain the distribution and amount of soil PyC in ZOT forests will help to improve model estimates of SOC change with further climatic warming.Coordination for the Improvement of Higher Education Personnel (CAPES)Natural Environment Research Council (NERC

    Compressed representation of a partially defined integer function over multiple arguments

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    In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one
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