Bioavailability, ecotoxicity, and geological characteristics of trace lead in sediments from two sites on Negro River, Uruguay, South America.

Bioassays of two sites along the Rio Negro in Uruguay indicate ecotoxicity, which could be attributable to trace concentrations of lead in river sediments. Monthly samples at two sites at Baygorria and Bonete locations were analyzed for both particle size and lead. Lead was determined by atomic spectrometry in river water and sediment and particle size by sieving and sedimentation.

A dicistronic gene pair within a cluster of "EF-hand" protein genes in the genomes of Drosophila species.

Androcam is a Drosophila melanogaster calmodulin-related protein that functions specifically in the testis. We show that the Acam gene is part of a cluster of three intronless genes arranged in a head-to-tail manner. The additional genes also encode calmodulin-related proteins with testis-specific transcription.