Reduction capability of soil humic substances from the Rio Negro basin, Brazil, towards Hg(II) studied by a multimethod approach and principal component analysis (PCA)

This paper characterizes humic substances (HS) extracted from soil samples collected in the Rio Negro basin in the state of Amazonas, Brazil, particularly investigating their reduction capabilities towards Hg(II) in order to elucidate potential mercury cycling/volatilization in this environment. For this reason, a multimethod approach was used, consisting of both instrumental methods (elemental analysis, EPR, solid-state NMR, FIA combined with cold-vapor AAS of Hg(0)) and statistical methods such as principal component analysis (PCA) and a central composite factorial planning method. The HS under study were divided into groups, complexing and reducing ones, owing to different distribution of their functionalities. The main functionalities (cor)related with reduction of Hg(II) were phenolic, carboxylic and amide groups, while the groups related with complexation of Hg(II) were ethers, hydroxyls, aldehydes and ketones. The HS extracted from floodable regions of the Rio Negro basin presented a greater capacity to retain (to complex, to adsorb physically and/or chemically) Hg(II), while nonfloodable regions showed a greater capacity to reduce Hg(II), indicating that HS extracted from different types of regions contribute in different ways to the biogeochemical mercury cycle in the basin of the mid-Rio Negro, AM, Brazil. (c) 2007 Published by Elsevier B.V.

Thermal Decomposition Kinetics of Humic Substances Extracted from Mid-Rio Negro (Amazon Basin) Soil Samples

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Distribution of Ra-226, Th-232 and K-40 in soils and sugar cane crops at Corumbatai river basin, São Paulo State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

New species of Harttia (Loricariidae, Loricariinae) from the Rio Sao Francisco Basin

A new species of the mailed catfish genus Harttia is described from the Sao Francisco River drainage, States of Minas Gerais and Bahia, Brazil. The new species is distinguished from congeners by the combination of an abdominal region covered by small bony plates; plates 3-4 times in eye diameter; interorbital width 3.1-4.0 in head length and greater than eye diameter; body width at anal fin origin 6.3-8.3 in standard length; margins of the head and pectoral fin spine of mature males with elongate and conspicuous odontodes; anal fin of males longer than of females. A key to Harttia species and a comparison with other species are provided.

Changes in biomass, chemical composition and nutritive value of Spartina alterniflora due to organic pollution in the Itanhaém River Basin (SP, Brazil)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Phylogeography and Pleistocene demographic history of the endangered marsh deer (Blastocerus dichotomus) from the Rio de la Plata Basin

The marsh deer is the largest neotropical cervid with morphological and ecological adaptations to wetlands and riparian habitats. Historically, this now endangered species occupied habitats along the major river basins in South America, ranging from southern Amazonia into northern Argentina to the Parana river delta. This particularly close association with wetlands makes marsh deer an excellent species for studying the effects of Pleistocene climatic changes on their demographic and phylogeographic patterns. We examined mitochondrial DNA variation in 127 marsh deer from 4 areas distributed throughout the Rio de]a Plata basin. We found 17 haplotypes in marsh deer from Brazil, Bolivia and Argentina that differed by 1-8 substitutions in a 601 bp fragment of mitochondrial control region sequence, and 486 bp of cytochrome b revealed only 3 variable sites that defined 4 haplotypes. Phylogeny and distribution of control region haplotypes suggest that populations close to the Pantanal area in central Brazil underwent a rapid population expansion and that this occurred approximately 28,000-25,000 years BP. Paleoclimatic data from this period suggests that there was a dramatic increase for precipitation in the medium latitudes in South America and these conditions may have fostered marsh deer's population growth.

Seasonality of macroalgal communities in a subtropical drainage basin in Paraná state, southern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Zircon fission track and U-Th-Pb in situ dating of Rio Parana Formation, Parana Basin, Brazil

Ages of zircon from sedimentary samples of Rio Parana Formation, belonging of Bauru Group, north of Parana Basin, Brazil, has been determined by zircon Fission Track and U-Th-Pb in situ dating methods. The obtained ages are from same zircon grain that provided information on the source areas for the sediments and the morphotectonic events.

Permian stromatolites associated with bivalve coquina beds-Angatuba, SP, Brazil (Teresina Formation, Parana Basin)

Silicified stromatolites have been described in the Permian Teresina Formation, Passa Dois Group, of the Parana Basin. These stromatolites occur as blocks in the Fazenda Monte Alegre area at the headwaters of the creek known as Corrego Catanduva in the municipality of Angatuba. These blocks originate from the Serra de Angatuba region and were recognized in a road that was cut in the midst of sandstones and siltites. The stromatolites are isolated bioherms that are domed to subspherical with a flat base in profile and a rounded to lenticular shape in plan view. The stromatolites exhibit a reddish coloration and are composed of microcrystalline quartz. Lamination is continuous, non-columnar, and anastomosed, showing parallel to divergent growth; however, divergent columns also occur, especially at the tops of the bioherms. The lamination is fine and well preserved, with alternating light and dark laminas. Microfossils of filamentous cyanobacteria are preserved and were related to the genera Microcoleus and Rivularia. Silicified bivalves occur in association with the stromatolites and are preserved in the form of coquina beds and rare isolated specimens within the bioherms. The described specimens belong to the Pinzonella illusa biozone, with representatives of the species Pinzonella illusa, Angatubia cowperesioides, and Houldausiella elongata. The formation environment of these stromatolites is associated with tidal plains of shallow, brackish, relatively calm, warm waters of good luminosity with the presence of weak currents. There was likely a low level of predation, and the environment may have been hypersaline. The coquina beds associated with the stromatolites indicate a probable proximal tempestite, i.e., they were formed near the coastline. The stromatolites were originally composed of carbonates, although these were replaced by silica during early diagenesis.

The definition of potential infiltration areas in Guaratingueta watershed, Paraiba do Sul Basin, Southeastern Brazil: an integrated approach using physical and land-use elements

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Allozyme differentiation of two populations of the genus Neoplecostomus Eigenmann & Eigenmann, 1888 (Teleostei, Loricariidae) from the upper Paraná River basin, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Survey for Foot-and-mouth Disease in the Endangered Marsh Deer (Blastocerus dichotomus) from Marshlands of the Parana River Basin, Brazil

Habitat fragmentation and diseases have resulted in a decline of the marsh deer (Blastocerus (dichotomus) throughout its South American range. Our objectives were to determine whether marsh deer intended for translocation from a region of the Rio Parana Basin had been infected previously by foot-and-mouth disease virus (FMDV) and whether they were carrying virus We captured marsh deer from June to October 1998 and collected blood from 108 animals and esophageal-pharyngeal fluid from 53 Serum was tested for antibodies against three FMDV serotypes (O, A, and C) by liquid-phase-blocking sandwich enzyme-linked immunosorbent assay (ELISA) Esophageal-pharyngeal fluid was tested for FMDV RNA by reverse transcription polymerase chain reaction (RT-PCR) and inoculation into three successive baby hamster kidney (BHK-21) cell subcultures, followed by RT-PCR of cultures We detected low log(10) titers (range 1 0-1 5) to FM DV subtype A(24) Cruzeiro in 19 of 108 sampled marsh deer, but failed to isolate FMDV or detect FMDV RNA in any samples we conclude that marsh deer from our study site were unlikely to carry FMDV, however, as a preventive measure, the 19 animals with titers for FMDV were not sent to FMDV-free Brazilian states

Biochemical evidence of a possible new species of Neoplecostomus (Teleostei : Loricariidae) from the upper Rio Parana basin, Brazil

Neoplecostomus paranensis Langeam, 1990, from the upper Rio Parana, is the only Neoplecostomus species described in this basin and is distinguished from its congeners by the lack or reduction of the adipose fin. Neoplecostomus specimens with a normal and always present adipose fin were caught in the Rio Corumba, upper Rio Parana basin. In the present study two samples of populations, one from a tributary of Rio Paranapanema (identified as a typical N. paranensis) and the other from the Rio Corumba were compared through allozyme electrophoresis. Six diagnostic loci were found, Acp-A, Adh-A, Est-A, Gpi-A, Ldh-A and Ldh-B. In addition, the locus Gpi-B showed significant differences between allelic frequencies for the two samples. Nei's genetic identity between the populations was 0.731. The expressive genetic divergence together with the presence of an adipose fin show that the sample from the Rio Corumba is distinct from N. paranensis and probably represents a new species. (C) 2003 Published by Elsevier Ltd.

A new Moenkhausia Eigenmann, 1903 (Ostariophysi: Characiformes) from Chapada Diamantina, rio Paraguaçu Basin, Bahia, Northeastern Brazil

Moenkhausia diamantina, nova espécie, é descrita de tributário do rio Paraguaçu, BA, nordeste do Brasil. Esta espécie é distinguida das demais congêneres por caracteres relacionados ao padrão de coloração do corpo, pela presença de escamas na linha mediana pré-dorsal e número de raios da nadadeira anal.

Deep barcode divergence in Brazilian freshwater fishes: the case of the Sao Francisco River basin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)