Biogenic sterols in sediment cores from the cabo frio upwelling-downwelling region, se atlantic, Brazil - Bícego, Márcia Caruso; Martins, César de Castro; Lourenço, Rafael André; Taniguchi, Satie; Montone, Rosalinda Carmela; Mahiques, Michel Michaelovitch de (Simpósio Nacional de Oceanografia, 3, 2006)