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Heimbuerger, Lars-eric; Cossa, Daniel; Marty, Jean-claude; Migon, Christophe; Averty, Bernard; Dufour, Aurelie; Ras, Josephine. |
Recent findings on the distribution of methylated mercury (MeHgT) in waters have highlighted the importance of organic carbon remineralization on the production of these compounds in the open ocean. Here, we present the first time-series (20 monthly samplings between July 2007 and May 2009) of high-resolution vertical profiles (10-12 depths in a 2350 m water column) of MeHgT distributions in an open ocean environment, the Ligurian Sea (North-western Mediterranean Sea). Concentrations varied within the sub-picomolar range (general mean: 0.30 0.17 pmol L-1, n = 214) with the lowest values at the surface, increasing with depth up to the oxygen minimum zone, and decreasing slowly at greater depth. Concentrations in the surface waters never exceeded 0.15 pmol... |
Tipo: Text |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12415/9225.pdf |
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Dheilly, Alexandra; Soum-soutera, Emmanuelle; Klein, Geraldine; Bazire, Alexis; Compere, Chantal; Haras, Dominique; Dufour, Aurelie. |
Biofilm formation results in medical threats or economic losses and is therefore a major concern in a variety of domains. In two-species biofilms of marine bacteria grown under dynamic conditions, Pseudoalteromonas sp. strain 3J6 formed mixed biofilms with Bacillus sp. strain 4J6 but was largely predominant over Paracoccus sp. strain 4M6 and Vibrio sp. strain D01. The supernatant of Pseudoalteromonas sp. 3J6 liquid culture (SN3J6) was devoid of antibacterial activity against free-living Paracoccus sp. 4M6 and Vibrio sp. D01 cells, but it impaired their ability to grow as single-species biofilms and led to higher percentages of nonviable cells in 48-h biofilms. Antibiofilm molecules of SN3J6 were able to coat the glass surfaces used to grow biofilms and... |
Tipo: Text |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00004/11530/11317.pdf |
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Heimbuerger, Lars-eric; Migon, Christophe; Dufour, Aurelie; Chiffoleau, Jean-francois; Cossa, Daniel. |
Climatic and anthropogenic changes are able to engender modifications in the aerosol composition at different geographical and temporal scales The present study addresses this question for the trace metal concentrations (TM = Al, Fe, Mn, Co, Ni, Cu, Pb, Cd and Zn) of aerosol from the North-western Mediterranean coast of France (Cap Ferrat, nearby Nice) between 1986 and 2008. From seasonal variations (2006-08) and decadal trends (1986-2008) of TM concentrations. three groups of elements can be distinguished They consist of different aerosol sources: crustal-derived elements (Al, Fe. Mn and Co), trace metals of anthropogenic origin (Pb, Cd and Zn) and a third, intermediate, group of trace metals that presented both anthropogenic and natural/crustal... |
Tipo: Text |
Palavras-chave: Trace metals; Aerosols; Anthropic impact; Mediterranean; Anti-pollution policy. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00006/11688/8503.pdf |
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Heimbuerger, Lars-eric; Migon, Christophe; Losno, Rémi; Miquel, Juan-carlos; Thibodeau, Benoit; Stabholz, Marion; Dufour, Aurelie; Leblond, Nathalie. |
We examined metal (Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb) and particulate organic carbon (OC) concentrations of the marine vertical export flux at the DYFAMED time-series station in the Northwestern Mediterranean Sea. We present here the first data set of natural and anthropogenic metals from sediment trap moorings deployed at 1000 m-depth between 2003 and 2007 at the DYFAMED site. A highly significant correlation was observed between most metal concentrations, whatever the nature and emission source of the metal. Cu, Zn and Cd exhibit different behaviors, presumably due to their very high solubility and complexation with organic ligands. The observed difference of atmospheric and marine fluxes in terms of temporal variability and elemental... |
Tipo: Text |
Palavras-chave: Trace metals; Sediment trap; Mediterranean Sea; Vertical export flux; Ballasting. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00176/28774/27247.pdf |
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Bastian, Luc; Revel, Marie; Bayon, Germain; Dufour, Aurelie; Vigier, Nathalie. |
Chemical weathering of silicate rocks on continents acts as a major sink for atmospheric carbon dioxide and has played an important role in the evolution of the Earth’s climate. However, the magnitude and the nature of the links between weathering and climate are still under debate. In particular, the timescale over which chemical weathering may respond to climate change is yet to be constrained at the continental scale. Here we reconstruct the relationships between rainfall and chemical weathering in northeast Africa for the last 32,000 years. Using lithium isotopes and other geochemical proxies in the clay-size fraction of a marine sediment core from the Eastern Mediterranean Sea, we show that chemical weathering in the Nile Basin fluctuated in parallel... |
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Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00376/48697/49030.pdf |
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