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| Registros recuperados: 98 | |
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| Cossa, Daniel; Garnier, Cedric; Buscail, Roselyne; Elbaz-poulichet, Francoise; Mikac, Nevenka; Patel-sorrentino, Nathalie; Tessier, Erwan; Rigaud, Sylvain; Lenoble, Veronique; Gobeil, Charles. |
| Methylation of mercury (Hg) is the crucial process that controls Hg biomagnification along the aquatic food chains. Aquatic sediments are of particular interest because they constitute an essential reservoir where inorganic divalent Hg (HgII) is methylated. Methylmercury (MeHg) concentrations in sediments mainly result from the balance between methylation and demethylation reactions, two opposite natural processes primarily mediated by aquatic microorganisms. Thus, Hg availability and the activity of methylating microbial communities control the MeHg abundance in sediments. Consistently, some studies have reported a significant positive correlation between MeHg and HgII or total Hg (HgT), taken as a proxy for HgII, in aquatic sediments using... |
| Tipo: Text |
Palavras-chave: Mercury; Methylmercury; Aquatic sediment; Methylation; Demethylation. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00171/28220/26520.pdf |
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| Guedron, Stephane; Grimaldi, Michel; Grimaldi, Catherine; Cossa, Daniel; Tisserand, Delphine; Charlet, Laurent. |
| Total mercury (HgT) and monomethylmercury (MMHg) were investigated in a tropical head watershed (1 km(2)) of French Guiana. The watershed includes a pristine area on the hill slopes and a former gold mined flat in the bottomland. Concentrations of dissolved and particulate HgT and MMHg were measured in rain, throughfall, soil water and at three points along the stream. Samples were taken in-between and during 14 storm events at the beginning and middle of the 2005 and 2006 rainy seasons. Dissolved and particulate HgT concentrations in the stream slightly increased downstream, while dissolved and particulate MMHg concentrations were low at the pristine sub-watershed outlet (median = 0.006 ng L-1 and 1.84 ng g(-1), respectively) and sharply increased at the... |
| Tipo: Text |
Palavras-chave: Mercury; Methylmercury; Tropical watershed; Gold placers; Stream water; Oxisols; Hydromorphic soils. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00035/14628/12134.pdf |
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| Klautau-Guimarães,Maria de Nazare; DAscenção,Renata; Caldart,Fabiana A.; Grisolia,Cesar K.; Souza,Jurandir R. de; Barbosa,Antonio C.; Cordeiro,Célia M.T.; Ferrari,Iris. |
| We investigated Individual differences in susceptibility to methylmercury (MeHg) contamination and its relationship with polymorphisms of the detoxifying enzyme glutathione S-transferase (GST). In Brazil, some Amerindian tribes from the Amazon region have an increased level of mercury in their hair. Samples of hair and blood were taken from inhabitants of two villages in the Kayabi and Munduruku Amerindian communities to investigate mercury levels in association with genetic polymorphism of GSTs. Other molecular biological markers were also studied, such as hemoglobin, haptoglobin and glucose 6-phosphate dehydrogenase (G-6-PDH). Higher levels of mercury contamination were found in the Kayabi villagers, who had a null genotype (GSTM1 0/0, also denominated... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amerindian; Genetic polymorphism; Glutathione S-transferase; Mercury. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000500027 |
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| Bas,Hatice; Kalender,Suna. |
| ABSTRACT This study was done to evaluate the effects of lead nitrate and mercury chloride in testis tissues of Wistar rats. Lead nitrate and mercury chloride are widely used heavy metals in industry. Oral lead and mercury administrations to adult male rats at doses 45 mg/kg bw and 0.02 mg/kg bw, respectively for 4 weeks caused a significant increasing in MDA levels and antioxidant enzyme activities (SOD, CAT, GPx and GST). The MDA levels and acivities of antioxidant enzymes was lower in rats that were administrated by lead nitrate than mercury chloride treated group. Light microscopic analyses revealed that lead nitrate and mercury chloride induced numerous histopathological changes in testis tissues of rats. Histopathological observations of the testis... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antioxidant enzymes; Lead; Mercury; Oxidative stress; Testis. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132016000100341 |
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| Hallstein, Eric; Villas-Boas, Sofia Berto. |
| This paper empirically investigates consumer response to a traffic light advisory for environmentally sustainable seafood, which was implemented in the seafood department of a regional supermarket chain in the United States. Green meant 'best choice'; yellow meant 'proceed with caution'; red meant 'worst choice'. Using a unique product-level panel scanner data set capturing sales information for 2 treatment stores and 8 nearby control stores, we apply a difference-in-differences identification strategy to estimate the impact of color-coded labels on consumers' purchases. We find that the advisory leads to no significant difference in total seafood sales. Green sales significantly increase an average of 29% per week; yellow sales significantly decrease an... |
| Tipo: Working Paper |
Palavras-chave: Sustainable seafood; Fisheries crisis; FishWise; Traffic light advisory; Mercury; Consumer/Household Economics. |
| Ano: 2009 |
URL: http://purl.umn.edu/120535 |
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| Cresson, Pierre; Bouchoucha, Marc; Miralles, F.; Elleboode, Romain; Mahe, Kelig; Marusczak, Nicolas; Thebault, Herve; Cossa, Daniel. |
| Mercury (Hg) is one of the main chemicals currently altering Mediterranean ecosystems. Red mullet (Mullus barbatus and M. surmuletus) have been widely used as quantitative bio-indicators of chemical contamination. In this study, we reassess the ability of these species to be used as efficient bio-indicators of Hg contamination by monitoring during 18 months Hg concentrations in muscle tissue of mullet sampled from 5 French Mediterranean coastal areas. Mean concentrations ranged between 0.23 and 0.78 μg g−1 dry mass for both species. Values were consistent with expected contamination patterns of all sites except Corsica. Results confirmed that red mullets are efficient bio-indicators of Hg contamination. Nevertheless, the observed variability in Hg... |
| Tipo: Text |
Palavras-chave: Mercury; Bio-indicator; Fish; Mullus spp.; Mediterranean. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00244/35514/34083.pdf |
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| Cruz, Kimberly; Guezennec, Jean; Barkay, Tamar. |
| Bacteria employ adaptive mechanisms of mercury (Hg) tolerance to survive in environments containing elevated Hg concentrations. The potential of extracellular polysaccharides (EPS) production by bacteria as a mechanism of Hg tolerance has not been previously investigated. The objectives of this study were to determine if bacterial EPS sorb Hg, and if so does sorption provide protection against Hg toxicity. Purified EPS with different chemical compositions produced by bacterial isolates from microbial mats in French Polynesian atolls and deep-sea hydrothermal vents were assessed for Hg sorption. The data showed that EPS sorbed up to 82% of Hg from solution, that this sorption was dependent on EPS composition, and that sorption was a saturable mechanism. Hg... |
| Tipo: Text |
Palavras-chave: Mercury; Bacteria; Sorption; Tolerance; Exocellular polysaccharides. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00382/49348/49786.pdf |
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| Lahaye, V; Bustamante, Paco; Law, J.r; Learmonth, J.a; Santos, M.b.; Boon, J.p.; Rogan, E; Dabin, W; Addink, M.j.; Lopez, A; Zuur, A.f.; Pierce, G.j.; Caurant, Florence. |
| Selected trace elements (Cd, Cu, Hg, Se, Zn) were measured in the kidneys and the liver of 104 harbour porpoises (Phocoena phocoena) stranded along the coasts of France, Galicia (Spain), Ireland, Scotland (UK), and the Netherlands. Generally, relatively low concentrations of toxic elements were encountered in the tissues of European porpoises, except for two individuals, which displayed high hepatic Hg concentrations. Also, elevated Cd levels obtained in Scottish porpoises could be related to their feeding preferences and this result suggests an increase of the proportion of cephalopods in their diet with latitude. Moreover, significant geographical differences were seen in hepatic Zn concentrations; the elevated Zn concentrations displayed by porpoises... |
| Tipo: Text |
Palavras-chave: Tracers; Multivariate analysis; Diet; Age; Marine mammals; Zinc; Cadmium; Mercury; Heavy metals. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2920.pdf |
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| Nakhle, K; Cossa, Daniel; Claisse, Didier; Beliaeff, Benoit; Simon, S. |
| The flounder (Platichthys flesus) is a flatfish that inhabits marine coastal environments, especially estuaries. It is an alternative quantitative biological indicator to the common marine mussel (Mytilus spp.), which is currently used as a sentinel species to monitor chemical contamination in numerous monitoring programmes. Findings from two decades of monitoring cadmium (Cd) and mercury (Hg) using both sentinel species in the Seine Estuary (France) are reported. For comparison, time-series of water concentrations for the same two metals at the mouth of the River Seine are given. Cd concentrations in the liver of the fish and in the soft tissue of mussels show similar temporal trends, consistent with the major temporal variations of Cd concentrations... |
| Tipo: Text |
Palavras-chave: Platichthys flesus; Mussel watch; Monitoring; Mercury; Flounder; Estuary; Cadmium. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3028.pdf |
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| Handayani, Kiki Syaputri; Soegianto, Agoes; Lignot, Jehan-hervé. |
| The effects of Hg exposure on blood parameters and gill physiology of tilapia (Oreochromis niloticus) were analyzed. Fish maintained in freshwater were exposed for 7 days (d) to sublethal mercury concentrations (0.1 and 1 mg/L). Blood serum osmolality (SO), sodium (Na+), potassium (K+) and chloride (Cl−) ionic concentrations, and hematological parameters were assessed after 1 up to 7 d of exposure. Serum osmolality and ionic concentrations of exposed fish appeared differently affected throughout the experimental period compared to the controls. Osmolality was reduced at the 2 tested concentrations but Na+ and Cl− contents were only altered at 1 mg/L of Hg after 1 d of exposure and values rapidly returned to the control values thereafter. K+ content was... |
| Tipo: Text |
Palavras-chave: Mercury; Tilapia; Osmoregulation; Serum ions; Blood; Aquatic toxicology. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00648/76033/76943.pdf |
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| Registros recuperados: 98 | |
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