RF Fingers for the New ESRF-EBS Storage Ring

International audienceIn the new ESRF-EBS (Extremely Brilliant Source) storage ring vacuum chambers assembly, with a reduced aperture and the new omega shape, RF fingers are a key component to ensure good vacuum conditions and reach the best possible machine performance. As a result, dedicated efforts were put into producing a more compact more robust more reliable and easier to assemble RF finger design for the new machine. The work was done in parallel on the beam coupling impedance reduction, which have a direct impact on the electron beam lifetime, and on the mechanical aspect with FEA validation and geometry optimization. Many test have been made, in a mechanical laboratory, including high resolution 3D computed tomography images in order to measure the electrical contact, and also in the existing ESRF storage ring with the electron beam, to validate the final design before launching the series productio

Hétérogénéité génotypique du déficit en G6PD à l’Ouest de l’Afrique Sub-saharienne

abstract: Hématologie 2000; 6(HS):45info:eu-repo/semantics/nonPublishe

Réserve Naturelle Nationale des prés salés d'Arès et de Lège-Cap Ferret (33) : connaissance et suivi des peuplements benthiques, supra-benthiques, ichtyologiques et des fonctions écologiques du compartiment tidal (programme de recherche Biamar 2012)

National audienceLes objectifs de cette étude étaient : • Le développement et l’expérimentation de méthodes réplicables pour l’étude du «couple» benthos/poissons, dans une optique à la fois de connaissance, de suivi et de gestion/conservation • La caractérisation des peuplements étudiés, en termes de richesses spécifiques, d’abondances relatives et de biomasses • L’étude de la dynamique spatio-temporelle (habitats/saisons) des peuplements étudiés • L’identification et la caractérisation des fonctions écologiques jouées par ces marais maritimes pour les poissons amphihalins

Assimilation of Allochthonous Matter by Estuarine Consumers During the 2015 El Niño Event

International audienceThe El Niño phenomenon refers to a warming of the tropical Pacific basin whose meteorological effects influence the dynamics of aquatic ecosystems around the world. Prior studies have shown that strong El Niño events are highly correlated with high rainfall episodes and high freshwater discharge into subtropical estuaries, with subsequent changes in species composition, abundance, and diversity of their biota. In this work, we evaluated the hypothesis that riverine allochthonous matter associated with the strong 2015 El Niño event is assimilated by decapod crustaceans and fishes of a southwestern Atlantic estuary. We analyzed carbon (δ13C) and nitrogen (δ15N) stable isotope ratios of primary food sources and consumers in the estuary and of riverine allochthonous matter. Our findings revealed that higher water surplus and lower salinity associated with the 2015 El Niño coincided with an increase in the number of freshwater fish species and a decrease in the number of marine- and estuarine-dependent fishes inside the estuary. In addition, most estuarine consumers had lower average δ13C values during the wet period associated with the 2015 El Niño. This seemed to reflect the assimilation of 13C-depleted riverine matter, which according to Bayesian isotope mixing models ranged from 11% (adult resident decapod crustaceans) to 60% (adult resident fishes) during the wet season. Further studies are needed to evaluate the role of El Niño events on structuring food web organization in estuaries under the influence of this climatic phenomenon, which may become more frequent and intense in a global warming scenario

Développement d'un indicateur poisson pour les eaux de transition : APR Liteau2 2005

[Departement_IRSTEA]Eaux [TR1_IRSTEA]QUASARENational audiencePrésentation des principaux résultats et préconisations pour l'action publique. Mise en application de l'indicateur et évolution de cet indicateur poisson depuis l'achèvement du projet Liteau II

Une méthode d'intercalibration des indicateurs poissons de la Directive Européenne sur l'Eau, basé sur l'utilisation d'un indice commun de pression anthropique

International audienceMost of the EU member states along the Northeast Atlantic coastline have developed different fish-based indices to assess the ecological status of transitional waters due to the Water Framework Directive. To be valid, each method should show a good correlation with a gradient of human pressures. In order to define a comparable view of what should be “good ecological status”, we performed an intercalibration of seven fish-based indices according to a common pressure index. Anthropogenic pressures were assessed by expert knowledge and best available pressure data. Nearly 170 estuaries from Portugal to Germany and Northern Ireland, where fish data existed, were qualified with 15 candidate pressure indicators. Only the indicators that showed a good regression to the biological assessment were selected. A set of 8 indicators assessing habitat degradation, contamination and dissolved oxygen composed the final common pressure index. The biological response is expressed as an Ecological Quality Ratio (EQR: score ranging between 0 and 1) divided into five quality classes. However, the seven methods differ regarding the boundary setting between these classes. Linear regressions were used to show the correlation between the common pressure index and the EQR obtained for each estuary. All the seven fish-based indices displayed a significant pressure-response relationship. A harmonisation band for the class boundaries was defined using the bias to the median value for all methods obtained on the common pressure index scale. A multi-rater Kappa analysis controlled the agreements between all methods in the attribution of a quality class. All methods showed significant trend in EQR values decrease with an increasing pressure value. All methods were able to discriminate between good or better and moderate or worst status. This intercalibration process enabled the comparison of EQR values despite very different ecological assessment strategies, monitoring regime and type of estuary

Robustness of the Estuarine Fish Assessment Index (EFAI) regarding water body definition criteria

According to the Water Framework Directive (WFD) transitional waters should be differentiated according to type and, in some cases, divided into different water bodies. This raises a dilemma in trying to define parts of a continuum. In the sequence of WFD several indices have been proposed including the Estuarine Fish Assessment Index, which can be applied taking an estuary as a whole (EFAI - without water bodies division) or divided in water bodies (EFAI(WB)). The purpose of this work is to analyze the robustness of the Estuarine Fish Assessment Index, based on three different ways of dividing Portuguese estuaries into water bodies according to different criteria (criterion 1 - distance to the estuary mouth, criterion 2 - salinity and criterion 3 - morphology, salinity and human dimension as pressure and state). In this study we evaluated at which degree these three criteria could influence the ecological quality ratio (EQR) results, when the index was applied to water body level (EFAI(WB)). Also, for each estuary, the EQR(WB) results for each criterion of EFAI(WB) were combined and weighted according to the water bodies areas (EFAI overall weighted - EFAI(Ow)). Finally, it was compared if the results obtained for each criterion with the EFAI(OW) were similar to the results of the index application taking the estuary as a whole (EFAI without water bodies division). No significant differences were found in both cases, which indicated that this index is a robust method regarding the division of the estuaries in different water bodies, which is an important element of a fish-based multimetric tool for assessing estuarine ecological quality. However, in some cases, different ecological quality statuses were achieved when applying the EFAI(Ow) or the EFAI. This work addressed several aspects regarding the possible division of water bodies at the WFD context. (C) 2012 Elsevier Ltd. All rights reserved