Eutrophication is one of the most important problems in the ecology of fresh waters. The aim of the present work was to investigate the effect of eutrophic overload (nitrates and phosphates) to the structure of zoobenthos in two types of experimental waters. Experimental mesocosms containing ground and water were used to investigate nitrate-phosphorus effect to hydrobionts. The negative effects...

Microcystin is a toxin secreted by cyanobacteria, which are the dominant phytoplankton in eutrophic freshwater bodies. The present study reports histopathological, hematological and biochemical changes in the freshwater fish, Heteropneustes fossilis due to toxicity of microcystin. Toxic effects were observed in liver, kidney, corpuscles of Stannius, gills and gonads. Bilirubin concentration inc...

NO(3) concentration profiles were measured in the sediments of a meso-eutrophic lake with a newly developed microelectrode. The depth of penetration of NO(3) varied from only 1.3 mm in organic-rich profundal silty sediments to 5 mm in organic-poor littoral sandy sediments. The thickness of the zone of denitrification in the organic-rich sediments was <500 mum. Oxygen profiles measured simultane...

In essential hypertension, conduit arteries present hypertrophic remodeling (increased cross-sectional area), whereas small arteries undergo eutrophic remodeling. The involvement of matrix metalloproteinases (MMPs) and de-adhesion proteins, such as tenascin-C and thrombospondin, has been relatively well characterized in large artery remodeling, but their contribution is not known in small arter...

We determined phosphate uptake by calcareous sediments at two locations within a shallow lagoon in Bermuda that varied in trophic status, with one site being mesotrophic and the other being more eutrophic. Phosphate adsorption over a six hour period was significantly faster in sediments from the mesotrophic site. Uptake at both sites was significantly less than that reported for a similar exper...

(Effects of nutrient impoverishment on phytoplankton biomass: a mesocosms experimental approach in a shallow eutrophic reservoir (Garças Pond), São Paulo, southeast Brazil). Nutrient impoverishment in mesocosms was carried out in a shallow eutrophic reservoir aiming to evaluate the nutrient removal technique as a method for eutrophication reduction. Garças Pond is located in the Parque Estadual...

Free living viruses are ubiquitous in marine waters and concentrations are usually several times higher than the bacterial abundance. These viruses are capable of lysing host bacteria and therefore, play an important role in the microbial loop in oligotrophic waters. However, few studies have been conducted to compare the role of viruses in regulating bacterial abundance and heterotrophic activ...