627 research outputs found

    Geosat sea-level assimilation in a tropical Atlantic model using Kalman filter

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    We present preliminary results on Geosat altimetric data assimilation in a linear vertical mode model of the tropical Atlantic Ocean. The Kalman filter technique is used to assimilate altimetric data along one track at a time as the satellite over-flies the basin. Sensitivity and validation tests have been performed with simulated data. The results obtained with Geosat data are presented and compared on a monthly basis with objective analysis of altimetric data and oceanic general circulation model results

    LCA of municipal solid waste incineration in France: from comprehensive site‐ specific data to Life Cycle Inventory modeling

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    In France, Municipal Solid Waste (MSW), including non-hazardous waste from economic activities collected together with post-consumer waste, are primarily incinerated (approximately 30% in 2010; ADEME, 2012). Yet, current Life Cycle Inventory databases do not precisely account for the characteristics of waste incineration in the specific French context, in particular with respect to air emissions, use of reactants, energy recovery rates and treatment of bottom ashes. This study accordingly aims at collecting environmental and energy data specific to French incinerators for their further integration into a dedicated Life Cycle Inventory model. The results of data collection and analysis are focused at in this presentation. Data were collected considering 90 French incinerators, respectively operated by SITA, TIRU and VEOLIA, and representing approximately 73% of the total mass of MSW incinerated in France as of 2012. Firstly, French incineration installations were classified according to their abatement technologies. Wet systems (with liquid emissions) combined with electrostatic precipitators and semi dry/semi wet systems combined with a fabric filter are predominant in France regarding dedusting and acid gas treatment (they respectively represent 34 and 25% of the total amount of waste incinerated). At the same time, Selective Catalytic Reduction (high temperature) combined with reactants for Dediox (36%) and Selective Non-Catalytic Reduction combined with reactants for Dediox (32%) are predominant with respect to NOx and dioxin abatement. Secondly, data of process-specific emissions (NOx, particles, dioxins, etc.) have been collected, considering 90 incinerators and 3 years in a raw (2012 to 2014), for their further statistical treatment by category of abatement technology. The correlation between emission factors and abatement technologies is discussed. Considering each kind of emission factor, a distribution of values is accordingly associated either with a given technology of abatement or with the whole French incineration installations. In addition, building on the mass balance at the scale of one French incineration plant, transfer coefficients are calculated in order to further infer waste-specific emissions (e.g. metals) in the model for Life Cycle Inventory of waste incineration in France. Finally, additional data relative respectively to energy (recovery and consumption), to the use of reactants and to downstream treatment of bottom ashes were collected and further statistically treated, considering the 90 incinerators under study. In particular, MSW appear to be incinerated primarily (55%) in plants cogenerating heat and electricity. As a conclusion, the potential use of these data in a Life Cycle Inventory model dedicated to French incineration is more specifically discussed. Acknowledgements This study was partly funded by the French Environment and Energy Management Agency (ADEME) in the framework of the PCI project. The authors wish to thank Patrick Boisseau (TIRU), Jacques Giacomoni (VEOLIA), Lionel Kosior (SITA) and CĂ©drik Priault (VEOLIA) for their contributions to this work. Reference: ADEME, 2012. L’incinĂ©ration des dĂ©chets mĂ©nagers et assimilĂ©s. Les avis de l’ADEME. DĂ©cembre 2012

    Recrutement des poissons dans le fjord du Saguenay

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    La faune ichtyologique du fjord du Saguenay est composĂ©e de plus de 60 espĂšces de poissons marins, diadromes et dulcicoles dont plusieurs font l’objet d’une pĂȘche rĂ©crĂ©ative comme l’éperlan arc-en-ciel anadrome (Osmerus mordax), le sĂ©baste (Sebastes spp.), la morue franche (Gadus morhua), la morue ogac (Gadus ogac) et le flĂ©tan du Groenland (Reinhardtius hippoglossoides). On ignore si le recrutement des poissons marins exploitĂ©s par la pĂȘche rĂ©crĂ©ative dans le Saguenay dĂ©pend de la production des stocks locaux ou des Ă©changes avec les populations de l’estuaire du Saint-Laurent. Nous avons donc Ă©tudiĂ© la distribution spatio-temporelle de l’ichtyoplancton dans le fjord du Saguenay afin d’identifier les zones de production, de rĂ©tention et d’advection larvaires dans le but d’y prĂ©ciser les mĂ©canismes de recrutement des stocks de poissons. L’ichtyoplancton a Ă©tĂ© Ă©chantillonnĂ© Ă  21 stations sur le fjord du Saguenay Ă  six occasions, de mai Ă  octobre 2004, et Ă  cinq occasions, de juin Ă  septembre 2005. Les rĂ©sultats montrent que le recrutement du capelan et de l’éperlan arc‑en‑ciel anadrome repose sur la production et la rĂ©tention des larves dans le fjord du Saguenay. Cependant, le recrutement des sĂ©bastes et des morues dĂ©pendrait de l’immigration de juvĂ©niles en provenance de l’estuaire du Saint-Laurent. Ces rĂ©sultats sont supportĂ©s par une revue des rĂ©sultats des Ă©tudes antĂ©rieures sur les poissons du fjord du Saguenay. L’étude des mĂ©canismes de recrutement des stocks de poissons du fjord du Saguenay favorise l’exploitation durable de ces ressources halieutiques conformĂ©ment Ă  la mission de PĂȘches et OcĂ©ans Canada et dans le respect du programme de conservation du parc marin du Saguenay‑Saint-Laurent.In the Saguenay Fjord, the fish community is composed of more than 60 marine, diadromous and freshwater species, including many species exploited by the winter sport fishery such as the rainbow smelt (Osmerus mordax), redfish (Sebastes spp.), Atlantic cod (Gadus morhua), Greenland cod (Gadus ogac), and Greenland halibut (Reinhardtius hippoglossoides). We do not know if the recruitment of the fish species exploited by the winter sport fishery depends on the local production of recruits in the Saguenay Fjord or on exchanges with the St. Lawrence Estuary populations. Hence, we measured the spatio-temporal distribution of ichthyoplankton in the Fjord to identify zones of larval production, retention or advection, in order to investigate the recruitment mechanisms of these stocks. We sampled ichthyoplankton at 21 stations on six occasions, from May to October 2004, and on five occasions, from June to September 2005. Results indicated that the recruitment of capelin (Mallotus villosus) and of the anadromous rainbow smelt (Osmerus mordax) relied on the local production and retention of larvae within the Fjord. However, the recruitment of redfish (Sebastes spp.) and cods (Gadus spp.) depended on the immigration of juveniles from the St. Lawrence Estuary. Our results are corroborated by a review of previous studies of these fish populations. Studying the recruitment mechanisms of fish populations in the Saguenay Fjord supports a sustainable exploitation of these locally important fisheries resources, in accordance with the mission of Fisheries and Oceans Canada and consistent with the conservation program of the Saguenay St. Lawrence Marine Park

    The project ENDORSE: exploiting EO data to develop pre-market services in renewable energy

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    International audienceThe ENDORSE project is co-funded by the FP7 programme of the European Commission, from 2011 to 2013. It exploits the atmosphere service MACC of the European GMES programme (Global Monitoring for Environment and Security) together with other Earth Observation (EO) data and modelling. It aims at providing public authorities and private investors with accurate evaluation and forecasts of renewable resources. The focus is on the devel-opment of downstream services that create added-value information. We present here the achievements of the first period. A very accurate though fast algorithm describing the position of the sun in the sky has been developed. A series of recommendations for quality control of meteorological data have been issued. All algorithms are available as code sources and are being implemented as Web processing services (WPS). Support vector machine techniques prove successful to map the air temperature at 2-m height from satellite images and a few measurements at ground level. The next development of ENDORSE is a portfolio of pre-market downstream services, serving as precursors and examples of best practices for similar services. The resulting services will be described using the INSPIRE metadata and declared in an existing Catalog Service for the Web (CSW) dedicated to energy. Finally, we discuss the mutual benefits between GEOSS (Global Earth Observation System of Systems) and ENDORSE

    African isolates show a high proportion of multiple copies of the Plasmodium falciparum plasmepsin-2 gene, a piperaquine resistance marker

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    Background: Today, the development of new and well-tolerated anti-malarial drugs is strongly justifed by the emer‑ gence of Plasmodium falciparum resistance. In 2014–2015, a phase 2b clinical study was conducted to evaluate the efcacy of a single oral dose of Artefenomel (OZ439)–piperaquine (PPQ) in Asian and African patients presenting with uncomplicated falciparum malaria. Methods: Blood samples collected before treatment ofered the opportunity to investigate the proportion of mul‑ tidrug resistant parasite genotypes, including P. falciparum kelch13 mutations and copy number variation of both P. falciparum plasmepsin 2 (Pfpm2) and P. falciparum multidrug resistance 1 (Pfmdr1) genes. Results: Validated kelch13 resistance mutations including C580Y, I543T, P553L and V568G were only detected in parasites from Vietnamese patients. In Africa, isolates with multiple copies of the Pfmdr1 gene were shown to be more frequent than previously reported (21.1%, range from 12.4% in Burkina Faso to 27.4% in Uganda). More strikingly, high proportions of isolates with multiple copies of the Pfpm2 gene, associated with piperaquine (PPQ) resistance, were frequently observed in the African sites, especially in Burkina Faso and Uganda (>30%). Conclusions: These fndings were considered to sharply contrast with the recent description of increased sensitivity to PPQ of Ugandan parasite isolates. This emphasizes the necessity to investigate in vitro susceptibility profles to PPQ of African isolates with multiple copies of the Pfpm2 gene and estimate the risk of development of PPQ resistance in Africa

    From In Situ to satellite observations of pelagic Sargassum distribution and aggregation in the Tropical North Atlantic Ocean

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    International audienceThe present study reports on observations carried out in the Tropical North Atlantic in summer and autumn 2017, documenting Sargassum aggregations using both ship-deck observations and satellite sensor observations at three resolutions (MSI-10 m, OLCI-300 m, VIIRS-750 m and MODIS-1 km). Both datasets reported that in summer, Sargassum aggre-gations were mainly observed off Brazil and near the Caribbean Islands, while they accumulated near the African coast in autumn. Based on in situ observations, we propose a five-class typology allowing standardisation of the description of in situ Sargassum raft shapes and sizes. The most commonly observed Sargassum raft type was windrows, but large rafts composed of a quasi-circular patch hundreds of meters wide were also observed. Satellite imagery showed that these rafts formed larger Sargassum aggregations over a wide range of scales, with smaller aggregations (of tens of m 2 area) nested within larger ones (of hundreds of km 2). Match-ups between different satellite sensors and in situ observations were limited for this dataset, mainly because of high cloud cover during the periods of observation. Nevertheless, comparisons between the two datasets showed that satellite sensors successfully detected Sargassum abundance and aggregation patterns consistent with in situ observations. MODIS and VIIRS sensors were better suited to describing the Sargas-sum aggregation distribution and dynamics at Atlantic scale, while the new sensors, OLCI and MSI, proved their ability to detect Sargassum aggregations and to describe their (sub-) mesoscale nested structure. The high variability in raft shape, size, thickness, depth and biomass density observed in situ means that caution is called for when using satellite maps of Sargassum distribution and biomass estimation. Improvements would require additional in situ and airborne observations or very high-resolution satellite imagery

    Polymorphisms in Plasmodium falciparum chloroquine resistance transporter and multidrug resistance 1 genes: parasite risk factors that affect treatment outcomes for P. falciparum malaria after artemether-lumefantrine and artesunate-amodiaquine.

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    Adequate clinical and parasitologic cure by artemisinin combination therapies relies on the artemisinin component and the partner drug. Polymorphisms in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug resistance 1 (pfmdr1) genes are associated with decreased sensitivity to amodiaquine and lumefantrine, but effects of these polymorphisms on therapeutic responses to artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) have not been clearly defined. Individual patient data from 31 clinical trials were harmonized and pooled by using standardized methods from the WorldWide Antimalarial Resistance Network. Data for more than 7,000 patients were analyzed to assess relationships between parasite polymorphisms in pfcrt and pfmdr1 and clinically relevant outcomes after treatment with AL or ASAQ. Presence of the pfmdr1 gene N86 (adjusted hazards ratio = 4.74, 95% confidence interval = 2.29 - 9.78, P < 0.001) and increased pfmdr1 copy number (adjusted hazards ratio = 6.52, 95% confidence interval = 2.36-17.97, P < 0.001 : were significant independent risk factors for recrudescence in patients treated with AL. AL and ASAQ exerted opposing selective effects on single-nucleotide polymorphisms in pfcrt and pfmdr1. Monitoring selection and responding to emerging signs of drug resistance are critical tools for preserving efficacy of artemisinin combination therapies; determination of the prevalence of at least pfcrt K76T and pfmdr1 N86Y should now be routine
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