La démarche qualité dans la recherche publique et l'enseignement supérieur /

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Modifications of pyrethroid effects associated with kdr mutation in Anopheles gambiae

Effects of knockdown resistance (kdr) were investigated in three pyrethroid-resistant (PR) strains of the Afrotropical mosquito #Anopheles gambiae$Giles (Diptera : Culicidae) : Kou from Burkina Faso, Tola and Yao from Côte d'Ivoire ; compared with a standard susceptible (SS) strain from Kisumu, Kenya. The kdr factor was incompletly recessive, conferring 43-fold resistance ratio at LD50 level and 29-fold at LD95 level, as determinated by topical application tests with Kou strain. When adult mosquitoes were exposed to 0.25$ was assessed by comparing "time to first take-off" (TO) for females. The standard TO50 and TO95 values for Kisumu SS on untreated paper were 58 and 1044s, respectively, vs. 3.7 and 16.5s on 1% permethrin. For Kou RR females the comparable values were 27.3s for TO50 and 294s for TO95, with intermediate RS values of 10.1s for TO50 and 71.9s for TO95. Thus, TO values for RS were 2.7-4.4 times more than for SS, and those for RR were 7-18 times longer than for SS. Experiments with pyrethroid-impregnated nets were designed to induce hungry female mosquitoes to pass through holes cut in the netting. Laboratory "tunnels tests" used a bait guinea-pig to attract mosquitoes through circular holes (5 x 1 cm) in a net screen. With untreated netting, 75-83% of laboratory-reared females passed through the holes overnight, 63-69% blood-fed successfully and 9-17% died, with no significant differences between SS and RR genotypes... (D'après résumé d'auteur

Study of the overall toxicity, water quality and microplastics of the peninsula of Cape Verde, Senegal [résumé]

ICAWA : International Conference AWA, Dakar, SEN, 13-/12/2016 - 15/12/2016Currently only thirteen percent (13 %) of domestic wastewater produced daily in Dakar is being treated. Industrial and agricultural activities and domestic waste are the source of significant pollution of the marine and coastal environment in Senegal. Our work focuses on assessing the overall toxicity of sediments, the microbiological and chemical quality of water, and the quantification of microplastics around the Cape Verde Peninsula. Physicochemical measurements are carried out in situ and the sampling points correspond to effluent outlets, compared to two reference stations that are assumed to have little or no contamination. A total of 15 sites were collected: Cambéréne, Yoff Tonghor, Ngor, Almadie-Vivier, Ouakam, Magdalen Islands, Soumbédioune, Dakar Dantec, Hann1, Hann2, Port of Dakar, Lac rose, Guédiawaye, Mamelles and UCAD. High sediment toxicity [100% ADL (Larval Development Anomalies)] was demonstrated at sixty percent (60%) of the sites. Twenty percent (20%) of sites have intermediate toxicity ranging from 30% to 60% ADL). Sites with the lowest toxicity (up to 30% ADL) accounted for only 20% and no ADL values were reported as nil. Mercury levels in sediments are very low, with a notable variation between sites in the north and those in the south of the peninsula. Coliforms (Escherichia coli) and enterococci are present in large quantities at most sites (64%). The presence of Salmonella is noted only in Cambéréne. The results of mass spectrometry analyzes also show overall high concentrations of heavy metals (Al, Cd, Cr, Co, Cu, Hg, Ni and Zn) with the exception of Fe and Mn, which are below the criteria for "Protection of acute and chronic aquatic life". Microplastic analysis revealed high mean values: 25,864 mpts / km2 (42 g / km2) for microplastics (300 µm and 5 mm) and 37,441 MPTS / km2 (97.33 g / km2) for macroplastics > 5 mm and < 200 mm). All the results obtained show, according to the pollutants, the importance of the sediment granulometry, the nature of the pollution, the size of the effluents, the anthropic contributions, the atmospheric falls like that of the behaviors of the populations. Our results are discussed with a view to environmental monitoring at the local, regional or national level. They will also allow this approach to be extended to other contaminants (hydrocarbons, metals, pesticides, megaplastics) as well as bio-trials in the various compartments of the marine and coastal environment (sediments, waters, fauna and flora ). An in-depth statistical analysis will also allow optimization of ecotoxicological monitoring, sampling and analysis strategies

Study of the overall toxicity, water quality and microplastics of the peninsula of Cape Verde, Senegal [résumé]

ICAWA : International Conference AWA, Dakar, SEN, 13-/12/2016 - 15/12/2016Currently only thirteen percent (13 %) of domestic wastewater produced daily in Dakar is being treated. Industrial and agricultural activities and domestic waste are the source of significant pollution of the marine and coastal environment in Senegal. Our work focuses on assessing the overall toxicity of sediments, the microbiological and chemical quality of water, and the quantification of microplastics around the Cape Verde Peninsula. Physicochemical measurements are carried out in situ and the sampling points correspond to effluent outlets, compared to two reference stations that are assumed to have little or no contamination. A total of 15 sites were collected: Cambéréne, Yoff Tonghor, Ngor, Almadie-Vivier, Ouakam, Magdalen Islands, Soumbédioune, Dakar Dantec, Hann1, Hann2, Port of Dakar, Lac rose, Guédiawaye, Mamelles and UCAD. High sediment toxicity [100% ADL (Larval Development Anomalies)] was demonstrated at sixty percent (60%) of the sites. Twenty percent (20%) of sites have intermediate toxicity ranging from 30% to 60% ADL). Sites with the lowest toxicity (up to 30% ADL) accounted for only 20% and no ADL values were reported as nil. Mercury levels in sediments are very low, with a notable variation between sites in the north and those in the south of the peninsula. Coliforms (Escherichia coli) and enterococci are present in large quantities at most sites (64%). The presence of Salmonella is noted only in Cambéréne. The results of mass spectrometry analyzes also show overall high concentrations of heavy metals (Al, Cd, Cr, Co, Cu, Hg, Ni and Zn) with the exception of Fe and Mn, which are below the criteria for "Protection of acute and chronic aquatic life". Microplastic analysis revealed high mean values: 25,864 mpts / km2 (42 g / km2) for microplastics (300 µm and 5 mm) and 37,441 MPTS / km2 (97.33 g / km2) for macroplastics > 5 mm and < 200 mm). All the results obtained show, according to the pollutants, the importance of the sediment granulometry, the nature of the pollution, the size of the effluents, the anthropic contributions, the atmospheric falls like that of the behaviors of the populations. Our results are discussed with a view to environmental monitoring at the local, regional or national level. They will also allow this approach to be extended to other contaminants (hydrocarbons, metals, pesticides, megaplastics) as well as bio-trials in the various compartments of the marine and coastal environment (sediments, waters, fauna and flora ). An in-depth statistical analysis will also allow optimization of ecotoxicological monitoring, sampling and analysis strategies

International conference ICAWA 2016 : extended book of abstract : the AWA project : ecosystem approach to the management of fisheries and the marine environment in West African waters

Currently only thirteen percent (13 %) of domestic wastewater produced daily in Dakar is being treated. Industrial and agricultural activities and domestic waste are the source of significant pollution of the marine and coastal environment in Senegal. Our work focuses on assessing the overall toxicity of sediments, the microbiological and chemical quality of water, and the quantification of microplastics around the Cape Verde Peninsula. Physicochemical measurements are carried out in situ and the sampling points correspond to effluent outlets, compared to two reference stations that are assumed to have little or no contamination. A total of 15 sites were collected: Cambéréne, Yoff Tonghor, Ngor, Almadie-Vivier, Ouakam, Magdalen Islands, Soumbédioune, Dakar Dantec, Hann1, Hann2, Port of Dakar, Lac rose, Guédiawaye, Mamelles and UCAD. High sediment toxicity [100% ADL (Larval Development Anomalies)] was demonstrated at sixty percent (60%) of the sites. Twenty percent (20%) of sites have intermediate toxicity ranging from 30% to 60% ADL). Sites with the lowest toxicity (up to 30% ADL) accounted for only 20% and no ADL values were reported as nil. Mercury levels in sediments are very low, with a notable variation between sites in the north and those in the south of the peninsula. Coliforms (Escherichia coli) and enterococci are present in large quantities at most sites (64%). The presence of Salmonella is noted only in Cambéréne. The results of mass spectrometry analyzes also show overall high concentrations of heavy metals (Al, Cd, Cr, Co, Cu, Hg, Ni and Zn) with the exception of Fe and Mn, which are below the criteria for "Protection of acute and chronic aquatic life". Microplastic analysis revealed high mean values: 25,864 mpts / km2 (42 g / km2) for microplastics (300 µm and 5 mm) and 37,441 MPTS / km2 (97.33 g / km2) for macroplastics > 5 mm and < 200 mm). All the results obtained show, according to the pollutants, the importance of the sediment granulometry, the nature of the pollution, the size of the effluents, the anthropic contributions, the atmospheric falls like that of the behaviors of the populations. Our results are discussed with a view to environmental monitoring at the local, regional or national level. They will also allow this approach to be extended to other contaminants (hydrocarbons, metals, pesticides, megaplastics) as well as bio-trials in the various compartments of the marine and coastal environment (sediments, waters, fauna and flora ). An in-depth statistical analysis will also allow optimization of ecotoxicological monitoring, sampling and analysis strategies

Study of the spatial variability of marine pollution around the peninsula of Cape Verde [résumé]

ICAWA : International Conference AWA, Dakar, SEN, 13-/12/2016 - 15/12/2016Marine pollution, the scourge of modern times, is due to the runoff of domestic and industrial waters as well as to various anthropogenic activities, i.e. products and objects deliberately or accidentally discharged into the sea. The samples taken from 11 sites on the Cap-Vert peninsula in Senegal, indicate the presence of certain polluting substances in varying amounts. The objective of this work is to study the correlations between the physical, microbiological and chemical parameters in order to highlight the similarities between the sites and, if possible, to determine the most relevant parameter(s) to characterize the pollution. PCA results have shown that some sites appear to be less chemically polluted than others that are more polluted with eutrophication and chemicals (e.g., copper, mercury). From a physical point of view, for example, we observe that the characteristics of sediments (large silt, clays, fine silt) are related to certain chemical parameters.The AFC performed between the overall toxicity of the sediments and the microbiological quality of the water shows that the site of Ouakam has a medium toxicity and a good microbiological quality while that of Cambérène and the Vivier are characterized respectively by bad and good quality but also by low toxicity at both sites. The two sites of Hann (Hann1 and Hann2), Soumbédioune, Ngor, Yoff Tonghor and Dakar Le Dantec are characterized by high toxicity and poor microbiological quality. Those in the Madeleine Islands and the Port of Dakar are characterized by high toxicity and bad microbiological quality. Moreover, as expected Soumbédioune appears as the most polluted sites in terms of microbiological load. The interest of the multivariate approach (ACP and AFC) is then discussed in this type of analysis

Study of the spatial variability of marine pollution around the peninsula of Cape Verde

International audienceMarine pollution, the scourge of modern times, is due to the runoff of domestic and industrial waters as well as to various anthropogenic activities, i.e. products and objects deliberately or accidentally discharged into the sea. The samples taken from 11 sites on the Cap-Vert peninsula in Senegal, indicate the presence of certain polluting substances in varying amounts. The objective of this work is to study the correlations between the physical, microbiological and chemical parameters in order to highlight the similarities between the sites and, if possible, to determine the most relevant parameter(s) to characterize the pollution. PCA results have shown that some sites appear to be less chemically polluted than others that are more polluted with eutrophication and chemicals (e.g., copper, mercury). From a physical point of view, for example, we observe that the characteristics of sediments (large silt, clays, fine silt) are related to certain chemical parameters.The AFC performed between the overall toxicity of the sediments and the microbiological quality of the water shows that the site of Ouakam has a medium toxicity and a good microbiological quality while that of Cambérène and the Vivier are characterized respectively by bad and good quality but also by low toxicity at both sites. The two sites of Hann (Hann1 and Hann2), Soumbédioune, Ngor, Yoff Tonghor and Dakar Le Dantec are characterized by high toxicity and poor microbiological quality. Those in the Madeleine Islands and the Port of Dakar are characterized by high toxicity and bad microbiological quality. Moreover, as expected Soumbédioune appears as the most polluted sites in terms of microbiological load. The interest of the multivariate approach (ACP and AFC) is then discussed in this type of analysis

Study of the spatial variability of marine pollution around the peninsula of Cape Verde

International audienceMarine pollution, the scourge of modern times, is due to the runoff of domestic and industrial waters as well as to various anthropogenic activities, i.e. products and objects deliberately or accidentally discharged into the sea. The samples taken from 11 sites on the Cap-Vert peninsula in Senegal, indicate the presence of certain polluting substances in varying amounts. The objective of this work is to study the correlations between the physical, microbiological and chemical parameters in order to highlight the similarities between the sites and, if possible, to determine the most relevant parameter(s) to characterize the pollution. PCA results have shown that some sites appear to be less chemically polluted than others that are more polluted with eutrophication and chemicals (e.g., copper, mercury). From a physical point of view, for example, we observe that the characteristics of sediments (large silt, clays, fine silt) are related to certain chemical parameters.The AFC performed between the overall toxicity of the sediments and the microbiological quality of the water shows that the site of Ouakam has a medium toxicity and a good microbiological quality while that of Cambérène and the Vivier are characterized respectively by bad and good quality but also by low toxicity at both sites. The two sites of Hann (Hann1 and Hann2), Soumbédioune, Ngor, Yoff Tonghor and Dakar Le Dantec are characterized by high toxicity and poor microbiological quality. Those in the Madeleine Islands and the Port of Dakar are characterized by high toxicity and bad microbiological quality. Moreover, as expected Soumbédioune appears as the most polluted sites in terms of microbiological load. The interest of the multivariate approach (ACP and AFC) is then discussed in this type of analysis

Recent progress on the realization of chalcogenides Photonic Crystal Fibers

Topic " Optoelectronic Materials and Devices ", conference 7212 " Optical Components and Materials VI ", session 4 " Passive Fibers " [7212-14]International audienceIn this work, we review recent progress on the realization of chalcogenides Photonic Crystal Fibers (PCFs). We present the fabrication of chalcogenide PCFs with a solid core for three different glass compositions containing a variety of chalcogens. We show that the Stack and Draw technique currently used for silica PCFs can be problematic in the case of chalcogenides glasses. We present correct PCF design enables a significant improvement of final fiber losses. We obtained a lowest attenuation of 3 dB/m at 1.55 µm, of 4.5 dB/m at 3.39 µm and 6 dB/m at 9.3 µm. We also present experimental demonstration of self phase modulation spectral broadening around 1,55 µm. Moreover, we investigate the Brillouin and Raman scattering properties of a GeSbS PCF