9 research outputs found
Association of CYP7A1 -278A>C polymorphism and the response of plasma triglyceride after dietary intervention in dyslipidemic patients
EtnobotĂąnica de Leguminosae entre agricultores agroecolĂłgicos na Floresta AtlĂąntica, Araponga, Minas Gerais, Brasil
Research Article Consequences of accelerated aging for DNA integrity and seed germination of cowpea
BRICS countriesâ strategies in the Arctic and the prospects for consolidated BRICS agenda in the Arctic
Relationship between soil oxidizable carbon and physical, chemical and mineralogical properties of umbric ferralsols
The occurrence of Umbric Ferralsols with thick umbric epipedons (> 100 cm thickness) in humid Tropical and Subtropical areas is a paradox since the processes of organic matter decomposition in these environments are very efficient. Nevertheless, this soil type has been reported in areas in the Southeast and South of Brazil, and at some places in the Northeast. Aspects of the genesis and paleoenvironmental significance of these Ferralsols still need a better understanding. The processes that made the umbric horizons so thick and dark and contributed to the preservation of organic carbon (OC) at considerable depths in these soils are of special interest. In this study, eight Ferralsols with a thick umbric horizon (UF) under different vegetation types were sampled (tropical rain forest, tropical seasonal forest and savanna woodland) and their macromorphological, physical, chemical and mineralogical properties studied to detect soil characteristics that could explain the preservation of high carbon amounts at considerable depths. The studied UF are clayey to very clayey, strongly acidic, dystrophic, and Al-saturated and charcoal fragments are often scattered in the soil matrix. Kaolinites are the main clay minerals in the A and B horizons, followed by abundant gibbsite and hydroxyl-interlayered vermiculite. The latter was only found in UFs derived from basalt rock in the South of the country. Total carbon (TC) ranged from 5 to 101 g kg-1 in the umbric epipedon. Dichromate-oxidizable organic carbon represented nearly 75 % of TC in the thick A horizons, while non-oxidizable C, which includes recalcitrant C (e.g., charcoal), contributed to the remaining 25 % of TC. Carbon contents were not related to most of the inorganic soil variables studied, except for oxalate-extractable Al, which individually explained 69 % (P < 0.001) of the variability of TC in the umbric epipedon. Clay content was not suited as predictor of TC or of the other studied C forms. Bulk density, exchangeable Al3+, Al saturation, ECEC and other parameters obtained by selective extraction were not suitable as predictors of TC and other C forms. Interactions between organic matter and poorly crystalline minerals, as indicated by oxalate-extractable Al, appear to be one of the possible organic matter protection mechanisms of these soils
Indicadores bioquĂmicos e hormonais de casos naturais de toxemia da prenhez em ovelhas
Toxemia da prenhez Ă© considerada um transtorno metabĂłlico de grande impacto econĂŽmico na produção de ovinos, porĂ©m as particularidades de repercussĂŁo sistĂȘmicas deste distĂșrbio ainda sĂŁo pouco esclarecedoras. O presente estudo teve por objetivo avaliar o perfil bioquĂmico e hormonal de 77 ovelhas com diagnĂłstico clĂnico de toxemia da penhez e comparar os achados laboratoriais de acordo com a resolução clĂnica dos animais, alta hospitalar (G1) e aqueles que morreram (G2). A manifestação clinica da doença foi observada no perĂodo do prĂ©-parto em 100% dos animais, destes 66,2 % (n=51) receberam alta clĂnica e 33,8% (n=26) morreram. Dos casos de toxemia da prenhez estudados havia gestação mĂșltipla em 55,8%. Dentre os parĂąmetros estudados, cortisol, urĂ©ia, AST e CK estavam mais elevados no G2 em relação ao G1 com diferenças significativas (P<0,05). Foi encontrado aumento nas concentraçÔes de glicose plasmĂĄtica, frutosamina, albumina, creatinina, Ă-hidroxubutirato, ĂĄcido graxo nĂŁo esterificado e L-lactato, porĂ©m nĂŁo houve diferenças entre os grupos (P>0,05). NĂŁo ocorreram alteraçÔes nas taxas de colesterol e triglicerĂdios. Houve redução nos Ăndices da insulina, nĂŁo havendo diferenças entre G1 e G2 (P>0,05). Todas as ovelhas apresentaram cetonĂșria e acidĂșria
Sombric-like horizon and xanthization in polychrome subtropical soils from Southern Brazil: implications for soil classification
The occurrence of dark subsurface horizons rich in organic matter (OM) associated with polychrome in the B horizon (yellowish over reddish hue) is common in soils from Southern Brazil. The formation of these horizons and the combination with such morphological attributes has not been properly documented, and neither has the cause effect relationship. Four soil profiles with such sombric-like horizons with a yellowish color at the upper part of the B horizon over red subsoil were studied in Southern Brazil. Results from micromorphology, extractable sesquioxide minerals, clay mineralogy and isomorphic substitution of Fe by Al in iron minerals showed that melanization, xanthization, bioturbation, moderate shrinking/swelling and moderate ferralitization were the most evident pedogenetic processes in role. Xanthization is closely related to the sombric-like horizon formation. In the studied area the findings demonstrated that no clay and OM illuviation had taken place. Therefore, the classification of these soils was revisited, so as to take into account the processes that underlie their genesis with emphasis on xanthization, clay illuviation and soil aggregation. The results suggest that the sombric horizon may need redefinition, unless profiles can be found in which illuviation of clay and/or OM can be proven