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ArchiMer, Institutional Archive of Ifremer (French Research Institute for Exploitation of the Sea) (9.673 recursos)

Archimer, is the institutional repository of Ifremer (French Research Institute for Exploitation of the Sea). It provides freely available scientific or technical documents online (publications, theses, conference proceedings, etc) in all fields related to oceans (oceanography, aquaculture, fisheries, etc). The site is available in French and English.


Mostrando recursos 1 - 20 de 229

  1. X-Linked Retinitis Pigmentosa 2 Is a Novel Maternal-Effect Gene Required for Left-Right Asymmetry in Zebrafish

    Desvignes, Thomas; Nguyen, Thaovi; Chesnel, Franck; Bouleau, Aurelien; Fauvel, Christian; Bobe, Julien
    Retinitis pigmentosa 2 (RP2) gene is responsible for up to 20% of X-linked retinitis pigmentosa, a severe heterogeneous genetic disorder resulting in progressive retinal degeneration in humans. In vertebrates, several bodies of evidence have clearly established the role of Rp2 protein in cilia genesis and/or function. Unexpectedly, some observations in zebrafish have suggested the oocyte-predominant expression of the rp2 gene, a typical feature of maternal-effect genes. In the present study, we investigate the maternal inheritance of rp2 gene products in zebrafish eggs in order to address whether rp2 could be a novel maternal-effect gene required for normal development. Although both...

  2. The estuarine geochemical reactivity of Zn isotopes and its relevance for the biomonitoring of anthropogenic Zn and Cd contaminations from metallurgical activities: Example of the Gironde fluvial-estuarine system, France

    Petit, Jerome C. J.; Schafer, Jörg; Coynel, Alexandra; Blanc, Gerard; Chiffoleau, Jean-francois; Auger, Dominique; Bossy, Cecile; Derriennic, Herve; Mikolaczyk, Mathilde; Dutruch, Lionel; Mattielli, Nadine
    Zinc stable isotopes measurements by MC-ICP-MS, validated by laboratory intercalibrations, were performed on wild oysters, suspended particles and filtered river/estuarine water samples to provide new constraints for the use of Zn isotopes as environmental tracers. The samples selected were representative of the long range (400 km) transport of metal (Zn, Cd, etc.) contamination from former Zn-refining activities at Decazeville (i.e. δ66Zn > 1 ‰) and its phasing out, recorded during 30 years in wild oysters from the Gironde Estuary mouth (RNO/ROCCH sample bank). The study also addresses additional anthropogenic sources (urban and viticulture) and focuses on geochemical reactivity of Zn...

  3. Rare earth elements and neodymium isotopes in world river sediments revisited

    Bayon, Germain; Toucanne, Samuel; Skonieczny, Charlotte; Andre, L.; Bermell, Sylvain; Cheron, Sandrine; Dennielou, Bernard; Etoubleau, Joel; Freslon, Nicolas; Gauchery, T.; Germain, Yoan; Jorry, Stephan; Menot, G.; Monin, L.; Ponzevera, Emmanuel; Rouget, M. -l.; Tachikawa, K.; Barrat, Jean-alix
    Over the past decades, rare earth elements (REE) and their radioactive isotopes have received tremendous attention in sedimentary geochemistry, as tracers for the geological history of the continental crust and provenance studies. In this study, we report on elemental concentrations and neodymium (Nd) isotopic compositions for a large number of sediments collected near the mouth of rivers worldwide, including some of the world’s major rivers. Sediments were leached for removal of non-detrital components, and both clay and silt fractions were retained for separate geochemical analyses. Our aim was to re-examine, at the scale of a large systematic survey, whether or...

  4. Two “pillars” of cold-water coral reefs along Atlantic European margins: Prevalent association of Madrepora oculata with Lophelia pertusa, from reef to colony scale

    Arnaud-haond, Sophie; Van Den Beld, Inge; Becheler, Ronan; Orejas, C.; Menot, Lenaick; Frank, N.; Grehan, A.; Bourillet, Jean-francois
    The scleractinian coral Lophelia pertusa has been the focus of deep-sea research since the recognition of the vast extent of coral reefs in North Atlantic waters two decades ago, long after their existence was mentioned by fishermen. These reefs where shown to provide habitat, concentrate biomass and act as feeding or nursery grounds for many species, including those targeted by commercial fisheries. Thus, the attention given to this cold-water coral (CWC) species from researchers and the wider public has increased. Consequently, new research programs triggered research to determine the full extent of the corals geographic distribution and ecological dynamics of...

  5. Iron isotope systematics in Arctic rivers

    Escoube, Raphaelle; Rouxel, Olivier; Pokrovsky, Oleg S.; Schroth, Andrew; Holmes, Robert Max; Donard, Olivier F. X.
    The input of iron to the Arctic Ocean plays a critical role in the productivity of aquatic ecosystems and is potentially impacted by climate change. We examine Fe isotope systematics of dissolved and colloidal Fe from several Arctic and sub-Arctic rivers in northern Eurasia and Alaska. We demonstrate that the Fe isotopic (δ56Fe) composition of large rivers, such as the Ob’ and Lena, has a restricted range of δ56Fe values ca.–0.11 ± 0.13‰, with minimal seasonal variability, in stark contrast to smaller organic-rich rivers with an overall δ56Fe range from–1.7 to + 1.6‰. The preferential enrichment with heavy Fe isotopes...

  6. Tidal Energy ”Round Robin” Tests Comparisons between towing tank and circulating tank results

    Gaurier, Benoit; Germain, Gregory; Facq, Jean-valery; Johnstone, C.m.; Grant, A.d.; Day, A.h.; Nixon, E.; Di Felice, F.; Costanzo, M.
    One key step of the industrial development of a tidal energy device is the testing of scale prototype devices within a controlled laboratory environment. At present, there is no available experimental protocol which addresses in a quantitative manner the differences which can be expected between results obtained from the different types of facilities currently employed for this type of testing. As a consequence, where differences between results are found it has been difficult to confirm the extent to which these differences relate to the device performance or to the test facility type. In the present study, a comparative ”Round Robin” testing...

  7. Performance assessment of a vertical axis turbine in a marine current flume tank and CFD modelling

    Rolland, S.a.; Thatcher, M.; Ellis, R.; Gaurier, Benoit; Croft, T.n.; Cross, M.
    As advances in numerical modelling techniques support the increased confidence in predictions from computer simulations, the need remains to have experimental verification built into the design process. This paper outlines the experimental investigation carried out on a shielded vertical axis turbine in a marine environment. The experiments consist of performance measurements and the use of particle image velocimetry on a small scale device in a marine current flume. The results demonstrate that the performance of the device can be modelled numerically; in particular, the results show that the numerical model used can correctly predict the increase in performance with Reynolds...

  8. The impact of the MARINET initiative on the development of Marine Renewable Energy

    Maisondieu, Christophe; Healy, Mark
    Marine Renewable Energy Conversion systems comprise wave energy and tidal stream converters as well as offshore-wind turbines for electrical generation. These technologies are currently at different stages of development but are mostly at the pre-commercial stage and require research to be undertaken at a series of scales along the path to commercialization. However each of these technologies also needs specific research infrastructures in order to conduct this research. The aim of the MARINET initiative is to coordinate research and development at all scales (small models through to prototype scales, from laboratories through to open sea tests) and to allow access...

  9. Structure, transports and transformations of the water masses in the Atlantic Subpolar Gyre

    Garcia-ibanez, Maribel I.; Pardo, Paula C.; Carracedo, Lidia; Mercier, Herle; Lherminier, Pascale; Rios, Aida F.; Perez, Fiz F.
    We discuss the distributions and transports of the main water masses in the North Atlantic Subpolar Gyre (NASPG) for the mean of the period 2002–2010 (OVIDE sections 2002–2010 every other year), as well as the inter-annual variability of the water mass structure from 1997 (4x and METEOR sections) to 2010. The water mass structure of the NASPG, quantitatively assessed by means of an Optimum MultiParameter analysis (with 14 water masses), was combined with the velocity fields resulting from previous studies using inverse models to obtain the water mass volume transports. We also evaluate the relative contribution to the Atlantic Meridional...

  10. Coping styles in farmed fish: consequences for aquaculture

    Castanheira, Maria Filipa; Conceição, Luís E.c.; Millot, Sandie; Rey, Stephanie; Bégout, Marie-laure; Damsgård, Børge; Kristiansen, Tove; Höglund, Erik; Øverli, Øyvind; Martins, Catarina I.m.
    Individual differences in physiological and behavioural responses to stressors are increasingly recognised as adaptive variation and thus raw material for evolution and fish farming improvements including selective breeding. Such individual variation has been evolutionarily conserved and is present in all vertebrate taxa including fish. In farmed animals, the interest in consistent trait associations, that is coping styles, has increased dramatically over the last years because many studies have demonstrated links to performance traits, health and disease susceptibility and welfare. This study will review (i) the main behavioural, neuroendocrine, cognitive and emotional differences between reactive and proactive coping styles in farmed...

  11. Structure Elucidation, Relative LC–MS Response and In Vitro Toxicity of Azaspiracids 7–10 Isolated from Mussels (Mytilus edulis)

    Kilcoyne, Jane; Twiner, Michael J.; Mccarron, Pearse; Crain, Sheila; Giddings, Sabrina D.; Foley, Barry; Rise, Frode; Hess, Philipp; Willdns, Alistair L.; Miles, Christopher O.
    Azaspiracids (AZAs) are marine biotoxins produced by dinoflagellates that can accumulate in shellfish, which if consumed can lead to poisoning events. AZA7–10, 7–10, were isolated from shellfish and their structures, previously proposed on the basis of only LC–MS/MS data, were confirmed by NMR spectroscopy. Purified AZA4–6, 4–6, and 7–10 were accurately quantitated by qNMR and used to assay cytotoxicity with Jurkat T lymphocyte cells for the first time. LC–MS(MS) molar response studies performed using isocratic and gradient elution in both selected ion monitoring and selected reaction monitoring modes showed that responses for the analogues ranged from 0.3 to 1.2 relative...

  12. A Lagrangian Method to Isolate the Impacts of Mixed Layer Subduction on the Meridional Overturning Circulation in a Numerical Model

    Thomas, Matthew; Treguier, Anne-marie; Blanke, Bruno; Deshayes, Julie; Voldoire, Aurore
    Large differences in the Atlantic meridional overturning circulation (AMOC) exhibited between the available ocean models pose problems as to how they can be interpreted for climate policy. A novel Lagrangian methodology has been developed for use with ocean models that enables a decomposition of the AMOC according to its source waters of subduction from the mixed layer of different geographical regions. The method is described here and used to decompose the AMOC of the Centre National de Recherches Météorologiques (CNRM) ocean model, which is approximately 4.5 Sv (1 Sv = 106 m3 s−1) too weak at 26°N, compared to observations....

  13. Argos-3 Satellite Communication System: Implementation on the Arvor Oceanographic Profiling Floats

    Andre, Xavier; Moreau, Bertrand; Le Reste, Serge
    The scientific community observes the ocean for applications in the fields of oceanography and climate research. In order to recover in situ data, more than 3,000 profiling floats are operated in the framework of the Argo Program. Each float performs cycles between the sea surface and a depth of 2,000 meters. Scientific data are gathered while the float is travelling upward from the depths of the oceans, and are then transmitted via a satellite communication system at the end of each cycle. During its time at the surface, mainly dedicated to transmissions, the float is vulnerable and subject to drift,...

  14. Population structure enhances perspectives on regional management of the western Indian Ocean green turtle

    Bourjea, Jerome; Mortimer, Jeanne A.; Garnier, Julie; Okemwa, Gladys; Godley, Brendan J.; Hughes, George; Dalleau, Mayeul; Jean, Claire; Ciccione, Stephane; Muths, Delphine
    To refine our understanding of the spatial structure of the green turtle (Chelonia mydas) populations in the South West Indian Ocean (SWIO), we analysed patterns of mitochondrial DNA (396 base pairs control region fragment) variation among 171 samples collected at five distinct locations (Kenya, Northern Mozambique, and three locations in the Republic of Seychelles: the Granitic, Amirantes, and Farquhar groups) and compared them to genetic data (n = 288), previously collected from 10 southern locations in the SWIO. We also analysed post-nesting satellite tracks (n = 4) from green turtles nesting in the Amirantes group. Pairwise comparisons of haplotype frequencies...

  15. Holocene turbidites record earthquake supercycles at a slow-rate plate boundary

    Ratzov, Gueorgui; Cattaneo, Antonio; Babonneau, Nathalie; Deverchere, Jacques; Yelles, Karim; Bracene, Rabah; Courboulex, Francoise
    Ongoing evidence for earthquake clustering calls for records of numerous earthquake cycles to improve seismic hazard assessment, especially where recurrence times overstep historical records. We show that most turbidites emplaced at the Africa-Eurasia plate boundary off west Algeria over the past ∼8 k.y. correlate across sites fed by independent sedimentary sources, requiring a regional trigger. Correlation with paleoseismic data inland and ground motion predictions support that M ∼7 earthquakes have triggered the turbidites. The bimodal distribution of paleo-events supports the concepts of earthquake supercycles and rupture synchronization between nearby faults: 13 paleo-earthquakes underpin clusters of 3–6 events with recurrence intervals...

  16. A European epidemiological survey of Vibrio splendidus clade shows unexplored diversity and massive exchange of virulence factors

    Nasfi, H.; Travers, Marie-agnes; De Lorgeril, Julien; Habib, C.; Sannie, T.; Sorieul, L.; Gerard, J.; Avarre, J. C.; Haffner, Philippe; Tourbiez, Delphine; Renault, Tristan; Furones, D.; Roque, A.; Pruzzo, C.; Cheslett, D.; Gdoura, R.; Vallaeys, T.
    The Vibrio splendidus clade has previously been associated with epidemic outbreaks of various aquatic animals, as in the case of the cupped oyster, Crassostrea gigas. To investigate whether involved strains could present a clonal origin and to identify possible alternative background carriage animals or zooplankton, a large epidemiological survey was conducted on isolates of the splendidus clade. For this purpose, Vibrio strains were isolated from various samples including oysters, mussels, sediments, zooplankton, and sea water on the basis of a North/South gradient of the European sea water zone (Ireland, The Netherlands, France, Italy, and Spain). A total of 435 isolates...

  17. Application of a new algorithm using Doppler information to retrieve complex wind fields over the Black Sea from ENVISAT SAR images

    Alpers, Werner; Mouche, Alexis; Horstmann, Jochen; Ivanov, Andrei Yu.; Barabanov, Vladyslav S.
    Several algorithms have been proposed to retrieve near-surface wind fields from C-band synthetic aperture radar (SAR) images acquired over the ocean. They mainly differ in the way they retrieve the wind direction. Conventionally, the wind direction is taken from atmospheric models or is extracted from the linear features sometimes visible in SAR images. Recently, a new wind retrieval algorithm has been proposed, which also includes the Doppler shift induced by motions of the sea surface. In this article, we apply three wind retrieval algorithms, including the one using Doppler information, to three complex wind events encountered over the Black Sea...

  18. Influence of one selected Tisochrysis lutea strain rich in lipids on Crassostrea gigas larval development and biochemical composition

    Da Costa, F.; Petton, Bruno; Mingant, Christian; Bougaran, Gael; Rouxel, Catherine; Quere, Claudie; Wikfors, G. H.; Soudant, P.; Robert, Rene
    Effects of a remarkably high overall lipid Tisochrysis lutea strain (T+) upon gross biochemical composition, fatty acid (FA), sterol and lipid class composition of Crassostrea gigas larvae were evaluated and compared with a normal strain of Tisochrysis lutea (T) and the diatom Chaetoceros neogracile (Cg). In a first experiment, the influence of different single diets (T, T+ and Cg) and a bispecific diet (TCg) was studied, whereas, effects of monospecific diets (T and T+) and bispecific diets (TCg and T+Cg) were evaluated in a second experiment. The strain T+ was very rich in triglycerides (TAG: 93–95% of total neutral lipids),...

  19. An autoregressive model to describe fishing vessel movement and activity

    Gloaguen, Pierre; Mahevas, Stephanie; Rivot, Etienne; Woillez, Mathieu; Guitton, Jerome; Vermard, Youen; Etienne, Marie-pierre
    The understanding of the dynamics of fishing vessels is of great interest to characterize the spatial distribution of the fishing effort and to define sustainable fishing strategies. It is also a prerequisite for anticipating changes in fishermen's activity in reaction to management rules, economic context, or evolution of exploited resources. Analyzing the trajectories of individual vessels offers promising perspectives to describe the activity during fishing trips. A hidden Markov model with two behavioral states (steaming and fishing) is developed to infer the sequence of non-observed fishing vessel behavior along the vessel trajectory based on Global Positioning System (GPS) records. Conditionally...

  20. Meteorological data from the EMSO-Azores seafloor observatory, 2012-2013

    Legrand, Julien; Sarradin, Pierre-marie; Cannat, Mathilde
    This dataset contains the meteorological parameters (mean wind speed, temperature in °C and atmospheric pressure in mbar) acquired between Jannuary 2012 and December 2013 (n=332) using the Furuno Rowind+, mounted at the top of BOREL superstructure (data acquired every 6 hours).

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