139 research outputs found
Bioanalytical characterisation of multiple endocrine- and dioxin-like activities in sediments from reference and impacted small rivers.
International audienceA comprehensive evaluation of organic contamination was performed in sediments sampled in two reference and three impacted small streams where endocrine disruptive (ED) effects in fish have been evidenced. The approach combined quantitative chemical analyses of more than 50 ED chemicals (EDCs) and a battery of in vitro bioassays allowing the quantification of receptor-mediated activities, namely estrogen (ER), androgen (AR), dioxin (AhR) and pregnane X (PXR) receptors. At the most impacted sites, chemical analyses showed the presence of natural estrogens, organochlorine pesticides, parabens, polycyclic aromatic hydrocarbons (16 PAHs), bisphenol A and alkylphenols, while synthetic steroids, myco-estrogens and phyto-estrogens were not detected. Determination of toxic-equivalent amounts showed that 28-96% of estrogenic activities in bioassays (0.2-6.3 ng/g 17beta-estradiol equivalents) were explained by 17beta-estradiol and estrone. PAHs were major contributors (20-60%) to the total dioxin-like activities. Interestingly, high PXR and (anti)AR activities were detected; however, the targeted analysed compounds could not explain the measured biological activities. This study highlighted the presence of multiple organic EDCs in French river sediments subjected to mixed diffuse pollution, and argues for the need to further identify AR and PXR active compounds in the aquatic environment
Mixtures of Chemical Pollutants at European Legislation Safety Concentrations: How Safe Are They?
The risk posed by complex chemical mixtures in the environment to wildlife and humans is increasingly debated, but has been rarely tested under environmentally relevant scenarios. To address this issue, two mixtures of 14 or 19 substances of concern (pesticides, pharmaceuticals, heavy metals, polyaromatic hydrocarbons, a surfactant, and a plasticizer), each present at its safety limit concentration imposed by the European legislation, were prepared and tested for their toxic effects. The effects of the mixtures were assessed in 35 bioassays, based on 11 organisms representing different trophic levels. A consortium of 16 laboratories was involved in performing the bioassays. The mixtures elicited quantifiable toxic effects on some of the test systems employed, including i) changes in marine microbial composition, ii) microalgae toxicity, iii) immobilization in the crustacean Daphnia magna, iv) fish embryo toxicity, v) impaired frog embryo development, and vi) increased expression on oxidative stress-linked reporter genes. Estrogenic activity close to regulatory safety limit concentrations was uncovered by receptor-binding assays. The results highlight the need of precautionary actions on the assessment of chemical mixtures even in cases where individual toxicants are present at seemingly harmless concentration
Mixtures of chemical pollutants at European legislation safety concentrations: how safe are they?
The risk posed by complex chemical mixtures in the environment to wildlife and humans is increasingly debated, but has been rarely tested under environmentally relevant scenarios. To address this issue, two mixtures of 14 or 19 substances of concern (pesticides, pharmaceuticals, heavy metals, polyaromatic hydrocarbons, a surfactant, and a plasticizer), each present at its safety limit concentration imposed by the European legislation, were prepared and tested for their toxic effects. The effects of the mixtures were assessed in 35 bioassays, based on 11 organisms representing different trophic levels. A consortium of 16 laboratories was involved in performing the bioassays. The mixtures elicited quantifiable toxic effects on some of the test systems employed, including i) changes in marine microbial composition, ii) microalgae toxicity, iii) immobilization in the crustacean Daphnia magna, iv) fish embryo toxicity, v) impaired frog embryo development, and vi) increased expression on oxidative stress-linked reporter genes. Estrogenic activity close to regulatory safety limit concentrations was uncovered by receptor-binding assays. The results highlight the need of precautionary actions on the assessment of chemical mixtures even in cases where individual toxicants are present at seemingly harmless concentrations
Identification of synthetic steroid compounds downstream of a pharmaceutical industry using effect directed analysis
International audienc
Contribution de l'approche effect directed analysis Ă l'identification de perturbateurs endocriniens dans les milieux aquatiques
The aim of this thesis was to develop and to evaluate an effect directed analysis (EDA) approach, combining in vitro bioassays and chemical analysis for the characterization of aquatic systems contamination by endocrine disrupting chemicals (EDCs) and their identification. For integrative contamination assessment, new in vitro tools have been developed and evaluated for the detection of emerging pollutants, and then integrated in a multi-bioassays approach. In particular, the human pregnane X receptor (PXR) based bioassay provided further information on bioactive contaminants and thereby enhanced the environmental diagnostic as regard to classical biological target (e.g. estrogen (ER), androgen (AR) or aryl hydrocarbon receptors (AhR)). Such multi-receptors approach allowed determining novel integrative toxicity profiles in sediment and surface water. Overall, our results demonstrated the need to integrate other biological target than ER and AhR, and to assess contamination partitioning for a better hazard/risk assessment. For such purpose, combined use of polar organic compound integrative sampler and in vitro bioassays provided suitable tools to assess active hydrosoluble chemicals in surface water. Finally, in order to identify the compounds responsible for the detected activities, the multi-receptors approach has been integrated in EDA strategy applied to two river sites under different chemical pressures (urban/agricultural and pharmaceutical). To tackle this challenge, extraction and fractionation methods were developed and evaluated in order to encompass a diversity of active chemicals that are detected by in vitro bioassays. The EDA approach allowed determining partial contribution of priority pollutants in biological responses as well as the identification of new EDCs.Lâobjectif gĂ©nĂ©ral de cette thĂšse concerne la mise en place et lâĂ©valuation dâune approche de type effect directed analysis (EDA), couplant bioessais in vitro et analyses physico-chimiques, pour la caractĂ©risation de la contamination des milieux aquatiques par les perturbateurs endocriniens (PE) et leur identification. De nouveaux outils in vitro ont Ă©tĂ© dĂ©veloppĂ©s et intĂ©grĂ©s Ă une approche multi-bioessais pour la dĂ©tection de polluants Ă©mergents afin de permettre un large diagnostic de la contamination par les PE. Parmi eux, le bioessai basĂ© sur le pregnane X receptor humain sâest avĂ©rĂ© complĂ©mentaire des cibles classiquement Ă©tudiĂ©es (e.g. rĂ©cepteurs des ĆstrogĂšnes (ER), des androgĂšnes (AR) ou des hydrocarbures aromatiques (AhR)). CombinĂ©s, ces bioessais ont permis de dĂ©terminer des profils intĂ©grĂ©s de la contamination inĂ©dits dans le sĂ©diment et les eaux de surface, mettant en lumiĂšre la nĂ©cessitĂ© de considĂ©rer dâautres cibles biologiques que ER et AhR et de sâintĂ©resser Ă lâensemble des compartiments du milieu aquatique pour une meilleure Ă©valuation de la contamination. En particulier, lâutilisation combinĂ©e de ces nouveaux outils Ă des capteurs passifs de type POCIS (polar organic compound integrative sampler) sâest rĂ©vĂ©lĂ©e pertinente pour Ă©valuer la contamination de la colonne dâeau par des composĂ©s hydrosolubles. Enfin, une dĂ©marche EDA, intĂ©grant ces bioessais et des mĂ©thodes physico-chimiques dâextraction et de fractionnement adaptĂ©es, a Ă©tĂ© validĂ©e pour lâidentification des composĂ©s dĂ©tectĂ©s. Son application sur deux sites soumis Ă des contaminations chimiques diffĂ©rentes (mixte urbaine/agricole et pharmaceutique) a permis dâĂ©valuer la contribution des polluants cibles, dont les prioritaires, dans les rĂ©ponses des bioessais et dâidentifier de nouveaux PE
Contribution of effect directed analysis approach to the identification of endocrine disrupting chemicals in aquatic systems
Lâobjectif gĂ©nĂ©ral de cette thĂšse concerne la mise en place et lâĂ©valuation dâune approche de type effect directed analysis (EDA), couplant bioessais in vitro et analyses physico-chimiques, pour la caractĂ©risation de la contamination des milieux aquatiques par les perturbateurs endocriniens (PE) et leur identification. De nouveaux outils in vitro ont Ă©tĂ© dĂ©veloppĂ©s et intĂ©grĂ©s Ă une approche multi-bioessais pour la dĂ©tection de polluants Ă©mergents afin de permettre un large diagnostic de la contamination par les PE. Parmi eux, le bioessai basĂ© sur le pregnane X receptor humain sâest avĂ©rĂ© complĂ©mentaire des cibles classiquement Ă©tudiĂ©es (e.g. rĂ©cepteurs des ĆstrogĂšnes (ER), des androgĂšnes (AR) ou des hydrocarbures aromatiques (AhR)). CombinĂ©s, ces bioessais ont permis de dĂ©terminer des profils intĂ©grĂ©s de la contamination inĂ©dits dans le sĂ©diment et les eaux de surface, mettant en lumiĂšre la nĂ©cessitĂ© de considĂ©rer dâautres cibles biologiques que ER et AhR et de sâintĂ©resser Ă lâensemble des compartiments du milieu aquatique pour une meilleure Ă©valuation de la contamination. En particulier, lâutilisation combinĂ©e de ces nouveaux outils Ă des capteurs passifs de type POCIS (polar organic compound integrative sampler) sâest rĂ©vĂ©lĂ©e pertinente pour Ă©valuer la contamination de la colonne dâeau par des composĂ©s hydrosolubles. Enfin, une dĂ©marche EDA, intĂ©grant ces bioessais et des mĂ©thodes physico-chimiques dâextraction et de fractionnement adaptĂ©es, a Ă©tĂ© validĂ©e pour lâidentification des composĂ©s dĂ©tectĂ©s. Son application sur deux sites soumis Ă des contaminations chimiques diffĂ©rentes (mixte urbaine/agricole et pharmaceutique) a permis dâĂ©valuer la contribution des polluants cibles, dont les prioritaires, dans les rĂ©ponses des bioessais et dâidentifier de nouveaux PE.The aim of this thesis was to develop and to evaluate an effect directed analysis (EDA) approach, combining in vitro bioassays and chemical analysis for the characterization of aquatic systems contamination by endocrine disrupting chemicals (EDCs) and their identification. For integrative contamination assessment, new in vitro tools have been developed and evaluated for the detection of emerging pollutants, and then integrated in a multi-bioassays approach. In particular, the human pregnane X receptor (PXR) based bioassay provided further information on bioactive contaminants and thereby enhanced the environmental diagnostic as regard to classical biological target (e.g. estrogen (ER), androgen (AR) or aryl hydrocarbon receptors (AhR)). Such multi-receptors approach allowed determining novel integrative toxicity profiles in sediment and surface water. Overall, our results demonstrated the need to integrate other biological target than ER and AhR, and to assess contamination partitioning for a better hazard/risk assessment. For such purpose, combined use of polar organic compound integrative sampler and in vitro bioassays provided suitable tools to assess active hydrosoluble chemicals in surface water. Finally, in order to identify the compounds responsible for the detected activities, the multi-receptors approach has been integrated in EDA strategy applied to two river sites under different chemical pressures (urban/agricultural and pharmaceutical). To tackle this challenge, extraction and fractionation methods were developed and evaluated in order to encompass a diversity of active chemicals that are detected by in vitro bioassays. The EDA approach allowed determining partial contribution of priority pollutants in biological responses as well as the identification of new EDCs
Contribution of effect directed analysis approach to the identification of endocrine disrupting chemicals in aquatic systems
Lâobjectif gĂ©nĂ©ral de cette thĂšse concerne la mise en place et lâĂ©valuation dâune approche de type effect directed analysis (EDA), couplant bioessais in vitro et analyses physico-chimiques, pour la caractĂ©risation de la contamination des milieux aquatiques par les perturbateurs endocriniens (PE) et leur identification. De nouveaux outils in vitro ont Ă©tĂ© dĂ©veloppĂ©s et intĂ©grĂ©s Ă une approche multi-bioessais pour la dĂ©tection de polluants Ă©mergents afin de permettre un large diagnostic de la contamination par les PE. Parmi eux, le bioessai basĂ© sur le pregnane X receptor humain sâest avĂ©rĂ© complĂ©mentaire des cibles classiquement Ă©tudiĂ©es (e.g. rĂ©cepteurs des ĆstrogĂšnes (ER), des androgĂšnes (AR) ou des hydrocarbures aromatiques (AhR)). CombinĂ©s, ces bioessais ont permis de dĂ©terminer des profils intĂ©grĂ©s de la contamination inĂ©dits dans le sĂ©diment et les eaux de surface, mettant en lumiĂšre la nĂ©cessitĂ© de considĂ©rer dâautres cibles biologiques que ER et AhR et de sâintĂ©resser Ă lâensemble des compartiments du milieu aquatique pour une meilleure Ă©valuation de la contamination. En particulier, lâutilisation combinĂ©e de ces nouveaux outils Ă des capteurs passifs de type POCIS (polar organic compound integrative sampler) sâest rĂ©vĂ©lĂ©e pertinente pour Ă©valuer la contamination de la colonne dâeau par des composĂ©s hydrosolubles. Enfin, une dĂ©marche EDA, intĂ©grant ces bioessais et des mĂ©thodes physico-chimiques dâextraction et de fractionnement adaptĂ©es, a Ă©tĂ© validĂ©e pour lâidentification des composĂ©s dĂ©tectĂ©s. Son application sur deux sites soumis Ă des contaminations chimiques diffĂ©rentes (mixte urbaine/agricole et pharmaceutique) a permis dâĂ©valuer la contribution des polluants cibles, dont les prioritaires, dans les rĂ©ponses des bioessais et dâidentifier de nouveaux PE.The aim of this thesis was to develop and to evaluate an effect directed analysis (EDA) approach, combining in vitro bioassays and chemical analysis for the characterization of aquatic systems contamination by endocrine disrupting chemicals (EDCs) and their identification. For integrative contamination assessment, new in vitro tools have been developed and evaluated for the detection of emerging pollutants, and then integrated in a multi-bioassays approach. In particular, the human pregnane X receptor (PXR) based bioassay provided further information on bioactive contaminants and thereby enhanced the environmental diagnostic as regard to classical biological target (e.g. estrogen (ER), androgen (AR) or aryl hydrocarbon receptors (AhR)). Such multi-receptors approach allowed determining novel integrative toxicity profiles in sediment and surface water. Overall, our results demonstrated the need to integrate other biological target than ER and AhR, and to assess contamination partitioning for a better hazard/risk assessment. For such purpose, combined use of polar organic compound integrative sampler and in vitro bioassays provided suitable tools to assess active hydrosoluble chemicals in surface water. Finally, in order to identify the compounds responsible for the detected activities, the multi-receptors approach has been integrated in EDA strategy applied to two river sites under different chemical pressures (urban/agricultural and pharmaceutical). To tackle this challenge, extraction and fractionation methods were developed and evaluated in order to encompass a diversity of active chemicals that are detected by in vitro bioassays. The EDA approach allowed determining partial contribution of priority pollutants in biological responses as well as the identification of new EDCs
Ground Truth for Pedestrian Analysis and Application to Camera Calibration
International audienceThis paper investigates the use of synthetic 3D scenes to generate ground truth of pedestrian segmentation in 2D crowd video data. Manual segmentation of objects in videos is indeed one of the most time-consuming type of assisted labeling. A big gap in computer vision research can not be filled due to this lack of temporally dense and precise segmentation ground truth on large video samples. Such data is indeed essential to introduce machine learning tech- niques for automatic pedestrian segmentation, as well as many other applications involving occluded people. We present a new dataset of 1.8 million pedestrian silhouettes presenting human-to-human occlusion patterns likely to be seen in real crowd video data. To our knowledge, it is the first publicly available large dataset of pedestrian in crowd silhouettes. Solutions to generate and represent this data are detailed. We discuss ideas of how this ground truth can be used for a large number of computer vision applications and demonstrate it on a camera calibration toy problem
Approches bio-analytiques pour la caractĂ©risation, la surveillance et lâidentification de perturbateurs endocriniens dans le milieu aquatique
International audienc
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