Rodrigo C. S. Costa

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This paper presents an algorithm for spots detection in Synthetic Aperture Radar (SAR) images that can be used to support environmental remote monitoring. Monitoring areas with high frequency of oil spillage by accidental or illegal oil discharges can prevent marine damage spreading. But the presence of speckle noise in SAR images limits the visual(More)
LASSBio-767 [(-)-3-O-acetyl-spectaline] and LASSBio-822 [(-)-3-O-tert-Boc-spectaline] were recently described as cholinesterase inhibitors derived from the natural piperidine alkaloid (-)-spectaline, obtained from the flowers of Senna spectabilis (Fabaceae). We investigated their mechanism of inhibition of acetylcholinesterase and their efficacy in(More)
This study evaluated the cholinesterase inhibitory activity of an alkaloid-rich fraction of stembark from Geissospermum vellosii (PP), and its effect on memory tests in mice. PP inhibited rat brain and electric eel acetylcholinesterase, as well as horse serum butyrylcholinesterase in a concentration-dependent manner with mean IC(50) values of 39.3(More)
Five new piperidine alkaloids were designed from natural (-)-3-O-acetyl-spectaline and (-)-spectaline that were obtained from the flowers of Senna spectabilis (sin. Cassia spectabilis, Leguminosae). Two semi-synthetic analogues (7 and 9) inhibited rat brain acetylcholinesterase, showing IC50 of 7.32 and 15.1 microM, and were 21 and 9.5 times less potent(More)
Identification of potential oil spills on Synthetic Aperture Radar (SAR) satellite images is a complex process. Oil companies, as well as the coast guard have tested a whole range of methods for monitoring and detection of possible oil spills. These methods are found to be expensive, complex and require high processing power and time. In this paper, an oil(More)
The aim of this study was to evaluate the effect of a supraseasonal drought on the ecological attributes of Plagioscion squamosissimus. The fish were caught quarterly from February 2010 to November 2014 using gill nets in the reservoir of Santa Cruz, Rio Grande do Norte, Brazil. The abundance of the species was evaluated with the catch per unit effort(More)