A shared socio-economic pathway based framework for characterising future emissions of chemicals to the natural environment

Chemicals are used in all aspects of our lives and are either intentionally or unintentionally released into the natural environment, leading to chemical pollution which negatively effects biodiversity and ecosystem and human health. The world is going through socio-economic, climate and technological changes that will affect chemical emissions to the natural environment but the extent of these affects is unknown. Scenarios of future chemical emissions are therefore needed to inform research and policy decisions to protect the health of humans and ecosystems into the future. In this article, we present a framework, based on Shared Socio-economics Pathways (SSPs) in combination with Representative concentration pathways (RCPs), to develop future chemical environmental emissions scenarios for single molecules or groups of chemicals sharing similar features. The framework has 4 steps: 1) determination of the characteristics of the scenario; 2) review and prioritisation of socio-economics and climate drivers; 3) development of scenarios; and 4) consistency checks. The framework is demonstrated for antidepressant and insecticide emissions into European freshwater-systems in 2050. Output narratives provide multiple pathways of chemical emissions in the future and can be used by researchers, regulators, politicians, governments, and the private sector to develop mitigation and adaptation strategies to chemical pollution issue

Evolution des interfaces a-C/Au et Au/a-C durant la progression d'un empilement de condensats ultrafins

Stacking sequences of gold on amorphous carbon (a-C) are realized by thermal evaporation under UHV. Simultaneous recordings of the planar current intensity I and the mass thickness e(a-C) or e(Au) of the condensate, a-C or gold, clearly show three regimes of increasing of I. The first regime is observed during the formation of a-C films which make up either the initial substrate or the covering of metal granular deposits after burying of grains. In this first regime, I increases very slowly with e (a-C). During the metal condensations the fast increase of I with e(Au) shows a second regime for the variation of I under atomic flux. When the covering of gold granular deposits by carbon atoms begins, the increase of I reaches a third regime which ends with the burying of grains. The conservation of the carbon atom flux causes then the reappearance of the first regime. These regime changes enable us to estimate the thickness of the a-C films, which is concerned with the 2-D variable range hopping (regime 1). The increase of I in regime 2, is accentuated by going from one bilayer of stacking sequence to the following. The theory of the tunnel effect between metal grains via the a-C substrate shows that the accentuated increase of the number density of grains explains that of the current intensity during the formation of two successive metallic condensates separated by an a-C film. An interpretation in terms of increase of the density of nucleation active sites is suggested.Des empilements d'or sur carbone amorphe (a-C) sont réalisés par évaporation thermique sous ultravide. L'enregistrement simultané du courant I circulant dans leur plan et de l'épaisseur massique e (a-C ) ou e (Au ) des condensats de a-C ou d'or fait clairement apparaître trois régimes de croissance de I. Le premier régime est celui observé durant la formation des films de a-C constituant soit le substrat initial, soit les couvertures des dépôts métalliques granulaires après ensevelissement des grains. Dans ce régime 1, I croît très lentement avec e(a-C). Durant les condensations de métal, la croissance rapide de I avec e (Au ) montre un second régime de variation de I sous flux atomique. Lorsque débute la couverture des dépôts granulaires d'or par des atomes de carbone, la croissance de I avec e(a-C) adopte un troisième régime qui se termine avec l'ensevelissement des grains. Le maintien du flux d'atomes de carbone fait alors réapparaître le régime 1. Ces changements de régime permettent d'estimer les épaisseurs du film de a-C, caractérisées par une conduction s'effectuant par sauts 2-D à distance variable (régime 1). La croissance de I dans le régime 2 augmente quand on passe d'un étage de l'empilement au suivant. La théorie de l'effet tunnel entre grains d'or via le substrat de a-C montre que cette augmentation traduit celle de la croissance de la densité des grains. Une interprétation en terme d'accroissement de la densité de sites actifs de nucléation est suggérée

Evolution de la granulométrie des dépôts discontinus d'or sur substrats de MgO

Dans nos précédents travaux la géométrie instantanée que présente sous flux les condensats métalliques était déterminée par itération à partir des mesures conjointes de la conductance de couche Cc et de l'épaisseur massique eD. A présent, nous nous proposons d'obtenir une vue d'ensemble de l'évolution géométrique en superposant à des abaques les courbes Cc (eD) relatives à divers systèmes Au/MgO. Ce procédé permet de mettre rapidement en évidence les nucléations primaires et secondaires et à plus haute température de condensation la croissance homothétique des agrégats

Evolution de la granulométrie des dépôts discontinus d'or sur substrats de MgO

In our previous works the instantaneous geometry which the metal condensates show under atomic flux is computed by iteration from both the sheet conductance and the mass thickness eD. Now our purpose is to get a general view over geometrical evolution by surimposing over abacus of curves Cc (eD) relative to several Au/MgO systems. This procedure enables us to quickly emphasize the primary and secondary nucleations and the homothetic growth of aggregates at higher condensation temperatures.Dans nos précédents travaux la géométrie instantanée que présente sous flux les condensats métalliques était déterminée par itération à partir des mesures conjointes de la conductance de couche Cc et de l'épaisseur massique eD. A présent, nous nous proposons d'obtenir une vue d'ensemble de l'évolution géométrique en superposant à des abaques les courbes Cc (eD) relatives à divers systèmes Au/MgO. Ce procédé permet de mettre rapidement en évidence les nucléations primaires et secondaires et à plus haute température de condensation la croissance homothétique des agrégats

Collisional excitation of interstellar PN by H 2 : New interaction potential and scattering calculations

International audienc

Accuracy of leptin serum level in diagnosing ventilator-associated pneumonia: a case-control study

Background. Undernutrition causes a reduction of body-fat mass and a decrease in the circulating concentration of leptin which impairs the production of proinflammatory cytokines and increases the incidence of infectious diseases. The main objective of this study was to determine whether leptin deficiency is a risk factor for ventilator-associated pneumonia (VAP). Methods. This prospective observational case-control study was conducted in a university ICU during a 2-year period. Patients with VAP (cases) were matched (1:1) to patients without VAP (controls) according to all the following criteria: age, gender, SAPS II, and duration of ICU stay before VAP occurrence. In all patients leptin, C-reactive protein (CRP) and procalcitonin (PCT) were measured at ICU admission, and twice a week. In addition, in cases, leptin, CRP and PCT were also measured on the day of VAP diagnosis. Results. Eighty-six cases were matched with 86 controls. No significant difference was found in leptin and PCT levels between cases and controls. CRP level was significantly higher on the day of VAP in cases compared with controls (99 vs. 48 mg/L, P=0.001). Combination of CRP-leptin (CRP >= 78 mg/L and leptin >= 6.2 ng/mL on the day of VAP) was significantly (P=0.009) associated with VAP in univariate analysis. Multivariate analysis identified the combination of CRP-leptin (OR [95% CI] 3.08 [1.18-8.04], P=0.003), LOD score (1.27 [1.08-1.48], P=0.003), neuromuscular-blockers use (6.6 [2.03-21.7], P=0.002), and reintubation (3.3 [1.14-9.6], P=0.027) as independent risk factors for VAP. Conclusion. In our study, leptin level was not associated with VAP occurrence. Further studies are needed to confirm our results, and to define the exact inflammatory role of leptin, and its interest as a biomarker in ICU patients