Cary L.,Bureau de Recherches Geologiques et Minieres |
Petelet-Giraud E.,Bureau de Recherches Geologiques et Minieres |
Bertrand G.,University of Sao Paulo |
Kloppmann W.,Bureau de Recherches Geologiques et Minieres |
And 17 more authors.
Science of the Total Environment | Year: 2015
In the coastal multilayer aquifer system of a highly urbanized southern city (Recife, Brazil), where groundwaters are affected by salinization, a multi-isotope approach (Sr, B, O, H) was used to investigate the sources and processes of salinization. The high diversity of the geological bodies, built since the Atlantic opening during the Cretaceous, highly constrains the heterogeneity of the groundwater chemistry, e.g. Sr isotope ratios, and needs to be integrated to explain the salinization processes and groundwater pathways. A paleoseawater intrusion, most probably the 120kyB.P. Pleistocene marine transgression, and cationic exchange are clearly evidenced in the most salinized parts of the Cabo and Beberibe aquifers. All 87Sr/86Sr values are above the past and present-day seawater signatures, meaning that the Sr isotopic signature is altered due to additional Sr inputs from dilution with different freshwaters, and water-rock interactions. Only the Cabo aquifer presents a well-delimitated area of Na-HCO3 water typical of a freshening process. The two deep aquifers also display a broad range of B concentrations and B isotope ratios with values among the highest known to date (63-68.5‰). This suggests multiple sources and processes affecting B behavior, among which mixing with saline water, B sorption on clays and mixing with wastewater. The highly fractionated B isotopic values were explained by infiltration of relatively salty water with B interacting with clays, pointing out the major role played by (palaeo)-channels for the deep Beberibe aquifer recharge. Based on an increase of salinity at the end of the dry season, a present-day seawater intrusion is identified in the surficial Boa Viagem aquifer. Our conceptual model presents a comprehensive understanding of the major groundwater salinization pathways and processes, and should be of benefit for other southern Atlantic coastal aquifers to better address groundwater management issues. © 2015 Elsevier B.V.. Source
Mollet L.,CNRS Center for Molecular Biophysics |
Robinet P.,CNRS Center for Molecular Biophysics |
Dubois M.,CNRS Center for Molecular Biophysics |
Aurouet A.,Geo Hyd |
And 9 more authors.
Molecular Immunology | Year: 2013
GALIG gene expression induces apoptosis in cultured cells through a pathway still under investigation. It is highly expressed in leukocytes but weakly detectable in bone marrow, suggesting a role in the myeloid lineage homeostasis. We show here that GALIG-induced cell death is counteracted by the overexpression of MCL-1, a pro-survival member of the Bcl2 family. Moreover, during spontaneous neutrophil apoptosis, a substantial increase in GALIG gene expression is observed: GALIG still opposes MCL-1. Finally, in bone marrow and peripheral blood cells from patients with Acute Myeloid Leukemia type 2, the level of GALIG transcripts is massively down-regulated when compared to their normal counterparts, while MCL-1 is expressed to the same extent. These data suggest that GALIG could be a key player in the cell death pathway involved in leukocytes homeostasis and myeloid malignancies. © 2013 Elsevier Ltd. Source
Dedewanou M.,CNRS Earth Sciences Institute of Orleans |
Binet S.,CNRS Earth Sciences Institute of Orleans |
Binet S.,CNRS Functional Ecology & Environment Laboratory |
Rouet J.L.,CNRS Earth Sciences Institute of Orleans |
And 3 more authors.
Water Resources Management | Year: 2015
Specific vulnerability estimations for groundwater resources are usually geographic information system-based (GIS) methods that establish spatial qualitative indexes which determine the sensitivity to infiltration of surface contaminants, but with little validation of the working hypothesis. On the other hand, lumped parameter models, such as the Residence Time Distribution (RTD), are used to predict temporal water quality changes in drinking water supply, but the lumped parameters do not incorporate the spatial variability of the land cover and use. At the interface between these two approaches, a GIS tool was developed to estimate the lumped parameters from the vulnerability mapping dataset. In this method the temporal evolution of groundwater quality is linked to the vulnerability concept on the basis of equivalent lumped parameters that account for the spatially distributed hydrodynamic characteristics of the overall unsaturated and saturated flow nets feeding the drinking water supply. This vulnerability mapping method can be validated by field observations of water concentrations. A test for atrazine specific vulnerability of the Val d’Orléans karstic aquifer demonstrates the reliability of this approach for groundwater contamination assessment. © 2015 Springer Science+Business Media Dordrecht Source