The constant increasing of eucalyptus forest areas in Brazil requires an accurate monitoring of water erosion. The present study aimed to evaluate soil, nutrients and organic carbon losses occasioned by water erosion in eucalyptus planted forests (EPF) at different development stages (2, 3 and 7 years old). Soil erosion sediments were measured and sampled from standard erosion plots installed on Red Argisol-RA (Ultisol) and Haplic Cambisol-HC (Inceptisol). Soil loss decreased as the age of plants increased; at the beginning of plant development, the canopy barely covered the soil surface, exposing the soil to higher erosion at young EPF plantations. Furrow planting system was used in the Red Argisol area and caused higher soil losses (1.1 to 6.2 Mg ha-1 year-1) as compared to pit planting system that was used in the Cambisol area (1.1 Mg ha-1 year-1). It is known that Cambisol is less resistant to erosion than Argisol. However, using pit system in this EPF, resulted in lower erosion and, therefore, nutrients and carbon losses than the traditional furrow system used in Argisol. Concerning the soil loss, this work points to the need of improving soil conservation practices to prevent soil erosion at the earlier stages of eucalyptus plantation. The amount of calcium and potassium were higher than magnesium in the soil sediment.The relatively high amount of carbon found in the erosion sediments raises additional concerns about the environmental sustainability and deserves future research.

R E S U M OO solo é um dos recursos naturais de maior importância cuja heterogeneidade reflete na variabilidade de seus atributos químicos e físicos. Esta heterogeneidade é decorrente do processo de formação natural e do uso e manejo realizados pelo homem. Assim, o objetivo deste estudo foi avaliar a variabilidade espacial dos atributos químicos e físicos do solo e elaborar seus mapas de distribuição espacial na Sub-Bacia das Posses, Extrema. Para isto foram coletadas amostras em 150 pontos nas profundidades de 0-0,20 e determinados os atributos físicos e químicos. As variáveis: Ca, Mg, K, P, pH, matéria orgânica (MO), diâmetro médio geométrico dos agregados (DMG cp ), diâmetro médio ponderado dos agregados (DMP cp ) e índice de floculação (IF). IF apresentaram estrutura de dependência espacial, o que permitiu seu mapeamento a partir de técnicas geoestatísticas. O P, DMG sp e DMP sp apresentaram estrutura com efeito pepita puro, possivelmente decorrente de uma distância insuficiente para captar dependência espacial na amostragem para esses atributos e interferências antrópicas. A variação verificada para o Ca pode ser explicada pela aplicação localizada de calcário, a qual foi realizada em algumas pequenas propriedades localizadas nas subbacias. O DMG p , DMP p , e IF avaliados foram ajustados em conformidade entre si indicando boa agregação do solo. Variability of soil attributes under pasturing and Atlantic Forest on the watershed basin scale A B S T R A C TSoil is one of the most important natural resource and its heterogeneity reflects the variability of its chemical and physical attributes. Soil heterogeneity occurs due to the natural process of formation and use by men and management. The objectives of this study were to evaluate the spatial variability of physical and chemical soil attributes and map the spatial distribution of these in Posses sub-basin, Extrema, representative of the Atlantic Forest biome present in southern Minas Gerais. For this, samples (0-0.20 m depth) were collected at 150 points, and their physical and chemical attributes were determined. Variables: Ca, Mg, K, P, pH, organic matter (MO), geometric mean diameter of aggregates (DMG cp) , weighted mean diameter of aggregates (DMP cp ) and flocculation index (IF) showed spatial dependence structure, which allowed mapping from geostatistical techniques. P, DMG sp and DMP sp presented structure with nugget effect, possibly due to an insufficient distance to capture spatial dependence in the sample for these attributes, and human interferences. The variation for Ca can be explained due to lime application, which occurred in some small properties located in the sub-basin. The DMG cp , DMP cp , and IF evaluated were adjusted in line with each other, indicating good soil aggregation. ISSN 1807 -1929 v.18, n.5, p.517-526, 2014 Introdução O Brasil é um país rico em recursos naturais distribuídos em seus diversos biomas. A Mata Atlântica é considerada, atualmente, seu bioma mais importante em razão do seu estado crítico -nela se concent...

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In this paper we report the design, synthesis and evaluation of a series of seleno-dihydropyrimidinones as potential multi-targeted therapeutics for Alzheimer's disease. The compounds show excellent results as acetylcholinesterase inhibitors, being as active as the standard drug. All these compounds also show very good antioxidant activity through different mechanisms of action.

Eucalyptus plantations are normally found in vulnerable ecosystems such as steep slope, soil with low natural fertility and lands that were degraded by agriculture. The objective of this study was to obtain Universal Soil Loss Equation (USLE) factors and use them to estimate water erosion risk in regions with eucalyptus planted. The USLE factors were obtained in field plots under natural rainfall in the Rio Doce Basin, MG, Brazil, and the model applied to assess erosion risk using USLE in a Geographic Information System. The study area showed rainfall-runoff erosivity values from 10,721 to 10,642 MJ mm ha-1 h-1 yr-1. Some soils (Latosols) had very low erodibility values (2.0 x 10-4 and 1.0 x 10-4t h MJ-1 mm-1), the topographic factor ranged from 0.03 to 10.57 and crop and management factor values obtained for native forest, eucalyptus and planted pasture were 0.09, 0.12 and 0.22, respectively. Water erosion risk estimates for current land use indicated that the areas where should receive more attention were mainly areas with greater topographic factors and those with Cambisols. Planning of forestry activities in this region should consider implementation of other conservation practices beyond those already used, reducing areas with a greater risk of soil erosion and increasing areas with very low risk.

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Carajurin is the main constituent of Arrabidaea chica species with reported anti-Leishmania activity. However, its mechanism of action has not been described. This study investigated the mechanisms of action of carajurin against promastigote forms of Leishmania amazonensis. Carajurin was effective against promastigotes with IC50 of 7.96 ± 1.23 μg.mL−1 (26.4 µM), and the cytotoxic concentration for peritoneal macrophages was 258.2 ± 1.20 μg.mL−1 (856.9 µM) after 24 h of treatment. Ultrastructural evaluation highlighted pronounced swelling of the kinetoplast with loss of electron-density in L. amazonensis promastigotes induced by carajurin treatment. It was observed that carajurin leads to a decrease in the mitochondrial membrane potential (p = 0.0286), an increase in reactive oxygen species production (p = 0.0286), and cell death by late apoptosis (p = 0.0095) in parasites. Pretreatment with the antioxidant NAC prevented ROS production and significantly reduced carajurin-induced cell death. The electrochemical and density functional theory (DFT) data contributed to support the molecular mechanism of action of carajurin associated with the ROS generation, for which it is possible to observe a correlation between the LUMO energy and the electroactivity of carajurin in the presence of molecular oxygen. All these results suggest that carajurin targets the mitochondria in L. amazonensis. In addition, when assessed for its drug-likeness, carajurin follows Lipinski’’s rule of five, and the Ghose, Veber, Egan, and Muegge criteria.

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