Upside down sulphate dynamics in a saline inland lake.

The sulphur cycle has a key role on the fate of nutrients through its several interconnected reactions. Although sulphur cycling in aquatic ecosystems has been thoroughly studied since the early 70's, its characterisation in saline endorheic lakes still deserves further exploration. Gallocanta Lake (NE Spain) is an ephemeral saline inland lake whose main sulphate source is found on the lake bed minerals and leads to dissolved sulphate concentrations higher than those of seawater.

Drivers of variability in mercury and methylmercury bioaccumulation and biomagnification in temperate freshwater lakes.

The four largest freshwater lakes in southwestern France are of both ecological and economic importance. However, some of them are subjected to mercury (Hg) contamination, resulting in the ban of human consumption of piscivorous fish. Moreover, beyond predatory fish, little information exist regarding Hg levels in other species of these ecosystems.

Importance of the vegetation-groundwater-stream continuum to understand transformation of biogenic carbon in aquatic systems - A case study based on a pine-maize comparison in a lowland sandy watershed (Landes de Gascogne, SW France).

During land-aquatic transfer, carbon (C) and inorganic nutrients (IN) are transformed in soils, groundwater, and at the groundwater-surface water interface as well as in stream channels and stream sediments. However, processes and factors controlling these transfers and transformations are not well constrained, particularly with respect to land use effect. We compared C and IN concentrations in shallow groundwater and first-order streams of a sandy lowland catchment dominated by two types of land use: pine forest and maize cropland.

Spectrophotometric determination of manganese in acidified matrices from (pore)waters and from sequential leaching of sediments.

Manganese (Mn) is a major redox reactive element in marine sediments and it plays an important role in the biogeochemical cycles of carbon, nitrogen, phosphorus, or trace metals. Mn cycle in marine sediments is characterized by an alternation of oxidation and reduction processes depending on physicochemical and biological conditions: assessing the quantification and the speciation of Mn is thus an essential issue to understand redox reaction-transport processes in sedimentary deposits. Solid Mn phases can be determined through chemical extractions techniques that permits selective leaching of operationally defined Mn fractions.

High-Content Screening of Plankton Alkaline Phosphatase Activity in Microfluidics.

One way for phytoplankton to survive orthophosphate depletion is to utilize dissolved organic phosphorus by expressing alkaline phosphatase. The actual methods to assay alkaline phosphate activity-either in bulk or as a presence/absence of enzyme activity-fail to provide information on individual living cells. In this context, we develop a new microfluidic method to compartmentalize cells in 0.