RESUMO
RESUMO Objetivou-se, no presente trabalho, monitorar e identificar precipitações erosivas e as perdas de solo (PSs) por meio de parcelas experimentais instaladas na Sub-Bacia do Córrego do Gigante, calibrar o modelo Water Erosion Prediction Project (WEPP) em sua versão encosta, tendo como base os resultados obtidos nas parcelas, e aplicá-lo na área da sub-bacia, para estimativa das PSs por erosão hídrica. O regime pluvial no período de estudo apresentou elevado grau de erosividade e de concentração, pois 57,3% dos eventos foram erosivos, dos quais, os quatro de maior magnitude, participaram com 47,2% da erosividade anual. As áreas contempladas pelas interações entre classe de solo, declividade (D) e uso de solo, nas parcelas experimentais, totalizaram 174,32 ha (50% da área da sub-bacia), cujos valores obtidos resultaram em PS média ponderada de 0,623 t ha-1 ano-1, e foram referência no ajuste do modelo WEPP na versão encosta, com estimativa de 0,651 t ha-1 ano-1. A aplicação do modelo sobre uma superfície com 93,0% de abrangência da sub-bacia resultou em uma estimativa de 0,802 t ha-1 ano-1 para a taxa de PS. As áreas de solo exposto, embora participando com apenas 7,9% da área da sub-bacia, produziram 85,1% das PSs estimadas, o que, por outro lado, reflete a influência positiva da cobertura vegetal na diminuição da erosão hídrica. Simulando a implantação de cobertura sob a forma de campo/pastagem e/ou reflorestamento, nas áreas de solo descoberto, as taxas de PS na sub-bacia reduziriam significativamente para 0,215 t ha-1 ano-1.
ABSTRACT The objective of the present work was to monitor and identify erosive precipitations and monitor soil losses through experimental plots installed in the Córrego do Gigante sub-basin, to calibrate the Water Erosion Prediction Project (WEPP) model, in its slope version, based on the results obtained in the plots, and apply it to the sub-basin area to estimate soil losses due to water erosion. The rainfall regime during the study period showed high degrees of erosivity and concentration, since 57% of the events were erosive, of which, the four most erosive events corresponded to 47.2% of the annual erosivity. The areas covered by the interactions between soil class, slope, and land use, in the experimental plots, totaled 174.32 ha (50% of the sub-basin area), whose values obtained resulted in a weighted average loss of 0.623 t ha-1 year-1, which were a reference in the adjustment of the WEPP model in the hillside version, with an estimate of 0.651 t ha-1 year-1. The application of the model on a surface with 93.0% coverage of the sub-basin resulted in an estimate of 0.802 t ha-1 year-1 for the soil loss rate. The exposed soil areas, although accounting for only 7.9% of the sub-basin area, produced 85.1% of the estimated soil losses, which, on the other hand, reflects the positive influence of vegetation cover in the decrease of water erosion. Simulating the implementation of cover in the form of field/pasture and/or reforestation in the areas of bare soil significantly reduced the rates of soil losses in the sub-basin to 0.215 t ha-1 year-1.
RESUMO
The continuous prospection for molecules that may be useful in the development of new therapeutic agents is a highly relevant issue, mainly because the launch of new drugs on the market does not accompany the emergence of new resistant microorganisms. In this context, this work describes the synthesis of new O-alkylamidoximes and the evaluation of its antifungal activity. The new O-alkylamidoximes were prepared using easy synthetic protocols and tested against three Candida species using the broth microdilution method. The synthesized compounds were obtained in moderate to good yields in high purity and without any observable decomposition. All tested compounds shown moderate antifungal activity against at least one strain of Candida. Despite the moderate activity of the new compounds, this was the first report involving the antifungal activity of O-alkylamidoximes. In view of the low chemotherapy arsenal and the development of fungal strains resistant to traditional antifungal agents, the present study opens new possibilities for the preparation of a new class of more active antifungal agents.