Consulta: creatorFacets:"Marin, Frederic"
Registros recuperados: 12
Data/hora: 06/06/2024 12:05:37

Characterization of molecular processes involved in the pearl formation in Pinctada margaritifera for a sustainable development of pearl farming industry in French Polynesia
Provedor de dados: 5
Autores: Gueguen, Yannick; Montagnani, Caroline; Joubert, Caroline; Marie, Benjamin; Belliard, Corinne; Tayale, Alexandre; Fievet, Julie; Levy, Peva; Piquemal, David; Marin, Frederic; Le Moullac, Gilles; Ky, Chin-long; Garen, Pierre; Lo, Cedrick; Saulnier, Denis.
Tahiti’s pearl farming industry plays a major socio-economic role in French Polynesia. In an increasingly competitive market where the production of high quality pearls becomes essential, research can help secure and ensure sustainable production. In that context, Ifremer, in close collaboration with the “direction des resources marines” (French Polynesian government agency) has developed research projects on the “sustainable development of pearl farming”. This program is organized along 3 axes: (1) understanding the animal physiology and initiating a genetically selective breeding program of donor oysters; (2) understanding pearl oyster larvae dispersal and recruitment; (3) understanding the molecular mechanisms underlying biomineralization processes...
Tipo: Text
Palavras-chave: Pearl oyster; Biomineralization; Pinctada margaritifera.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00167/27840/26049.pdf

The equatorial thermostad and subsurface countercurrents in the light of the dynamics of atmospheric Hadley cells
Provedor de dados: 5
Autores: Marin, Frederic; Hua, Bach-lien; Wacongne, Sophie.
The simple Held and Hou (1980) nearly inviscid model of the axisymmetric atmospheric circulation, rationalizing the existence of Hadley cells, Jet Streams, and tropical homogenization of potential temperature and vorticity, is adapted to the oceanic subthermocline region. The meridional profile of radiative equilibrium temperature, which provides the driving in the atmospheric case, is replaced, in the oceanic case, by the large-scale equatorial doming of the thermocline. The meridional structure of the equatorial thermostad and the existence, at its poleward flanks, of eastward subsurface countercurrents coincident with sharp potential vorticity gradients are thus explained via angular momentum redistribution by secondary ageostrophic over-turning cells...
Tipo: Text
Palavras-chave: Subthermocline region; Thermostad; Oceanic circulation.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-804.pdf

Oceanic transports through the Solomon Sea: The bend of the New Guinea Coastal Undercurrent
Provedor de dados: 5
Autores: Gasparin, Florent; Ganachaud, Alexandre; Maes, Christophe; Marin, Frederic; Eldin, Gerard.
Thermocline waters of the tropical southwest Pacific can be traced back to the center of the South Pacific basin and have a potential influence on equatorial surface conditions and on the characteristics of the El Nino Southern Oscillation on decadal timescales. The Solomon Sea is traversed by this influential flow, and therefore is an optimal place for exploring this oceanic connection to the equator. From a high-resolution hydrographic survey at which we applied an inverse box model, we describe the main pathways at the entrance of the Solomon Sea, and more particularly the extremely sharp bend of the western boundary current around the south-east tip of Papua New Guinea. Of the 30 Sv subtropical waters transported into the Coral Sea from the east, above...
Tipo: Text
Palavras-chave: Coral Sea; Solomon Sea; Oceanic transport.
Ano: 2012
URL: https://archimer.ifremer.fr/doc/00214/32501/30985.pdf

Deep Eddy Kinetic Energy in the Tropical Pacific From Lagrangian Floats
Provedor de dados: 5
Autores: Delpech, Audrey; Cravatte, S.; Marin, Frederic; Ménesguen, Claire; Morel, Y.
At the ocean surface, satellite observations have shown evidence of a large spectrum of waves at low latitudes. However, very little is known about the existence and properties of the deep variability. Most of the subsurface observations rely on localized measurements, which do not allow for a global estimation of this variability. In this study, we use velocity estimates, provided by Argo float drifts at 1,000 m, to analyze the spatial and temporal distribution of the deep eddy kinetic energy (EKE) and its spectral signature with an unprecedented time and space coverage. In the tropical Pacific, high EKE is found along the equator, at the western boundary and poleward of 7°N. EKE meridional distribution is also found to vary at the scale of the...
Tipo: Text
Palavras-chave: Deep ocean; Equatorial and tropical ocean; Eddy kinetic energy; Equatorial waves; Argo floats.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00643/75483/76329.pdf

Characterization of MRNP34, a novel methionine-rich nacre protein from the pearl oysters
Provedor de dados: 5
Autores: Marie, Benjamin; Joubert, Caroline; Belliard, Corinne; Tayale, Alexandre; Zanella-cleon, Isabelle; Marin, Frederic; Gueguen, Yannick; Montagnani, Caroline.
Nacre of the Pinctada pearl oyster shells is composed of 98% CaCO3 and 2% organic matrix. The relationship between the organic matrix and the mechanism of nacre formation currently constitutes the main focus regarding the biomineralization process. In this study, we isolated a new nacre matrix protein in P. margaritifera and P. maxima, we called Pmarg- and Pmax-MRNP34 (methionine-rich nacre protein). MRNP34 is a secreted hydrophobic protein, which is remarkably rich in methionine, and which is specifically localised in mineralizing the epithelium cells of the mantle and in the nacre matrix. The structure of this protein is drastically different from those of the other nacre proteins already described. This unusual methionine-rich protein is a new member in...
Tipo: Text
Palavras-chave: Matrix protein; Methionine-rich; Biomineralization; Mollusc; Nacre; Calcifying mantle.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00077/18870/16645.pdf

XBT Temperature Errors during French Research Cruises (1999-2007)
Provedor de dados: 5
Autores: Reverdin, Gilles; Marin, Frederic; Bourles, Bernard; Lherminier, Pascale.
Data from French cruises in 1999-2007, a period during which Deep Blue (DB) or T7 expendable bathythermographs (XBTs) were deployed, and for which ancillary temperature data are available in the northeast Atlantic and equatorial Atlantic regions, are examined. There was a total of 16 cruises with XBTs launched between conductivity-temperature-depth (CTD) stations; during most of these, as well as during three additional cruises that were also considered, intake temperature was measured. XBT data from two voluntary observing ships in the North Atlantic subpolar gyre for which intake temperature was measured were also investigated. There is an XBT cold bias due to stirring of a stratified upper layer by the ship, resulting in differences between XBT...
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00133/24380/22391.pdf

Mineral phase in shell repair of Manila clam Venerupis philippinarum affected by brown ring disease
Provedor de dados: 5
Autores: Trinkler, Nolwenn; Bardeau, Jean-francois; Marin, Frederic; Labonne, Maylis; Jolivet, Aurelie; Crassous, Philippe; Paillard, Christine.
The mineral phase of shell repair in the Manila clam Venerupis philippinarum affected by brown ring disease (BRD) was characterised at various scales and at various stages of shell repair by confocal Raman microspectrometry and scanning electron microscopy. Spherulitic and quadrangular aragonite microstructures associated with polyene pigments were clearly observed. Von Kossa staining showed that at the beginning of shell repair, hemocytes are filled with insoluble calcium carbonate salts in all fluids and then are transported toward the extrapallial fluids and the repair sites. Our analyses suggest that after a Vibrio tapetis attack and BRD deposit some clams rapidly cover the deposit, resulting in a modification in the microstructure, which could be...
Tipo: Text
Palavras-chave: Aragonite; Hemocytes; Shell microstructure; Calcium carbonate; Biomineralization; Mollusc; Raman microspectrometry; Scanning electron microscopy.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00029/14065/11301.pdf

From Mixing to the Large Scale Circulation: How the Inverse Cascade Is Involved in the Formation of the Subsurface Currents in the Gulf of Guinea
Provedor de dados: 5
Autores: Assene, Fernand; Morel, Yves; Delpech, Audrey; Aguedjou, Micael; Jouanno, Julien; Cravatte, Sophie; Marin, Frederic; Ménesguen, Claire; Chaigneau, Alexis; Dadou, Isabelle; Alory, Gael; Holmes, Ryan; Bourlès, Bernard; Koch-larrouy, Ariane.
In this paper, we analyse the results from a numerical model at high resolution. We focus on the formation and maintenance of subsurface equatorial currents in the Gulf of Guinea and we base our analysis on the evolution of potential vorticity (PV). We highlight the link between submesoscale processes (involving mixing, friction and filamentation), mesoscale vortices and the mean currents in the area. In the simulation, eastward currents, the South and North Equatorial Undercurrents (SEUC and NEUC respectively) and the Guinea Undercurrent (GUC), are shown to be linked to the westward currents located equatorward. We show that east of 20∘ W, both westward and eastward currents are associated with the spreading of PV tongues by mesoscale vortices. The...
Tipo: Text
Palavras-chave: Equatorial atlantic; NEUC (North Equatorial Undercurrents); SEUC (South Equatorial Undercurrents); Vortices; Mixing; Friction.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00645/75697/76601.pdf

Observed tracer fields structuration by mid-depth zonal jets in the tropical Pacific
Provedor de dados: 5
Autores: Delpech, Audrey; Cravatte, Sophie; Marin, Frederic; Morel, Yves; Gronchi, Enzo; Kestenare, Elodie.
The mid-depth ocean circulation in the tropical Pacific is dominated by sets of alternating eastward and westward jets. The origin and transport properties of these flow features remain in many ways an open question, all the more crucial since their usual underestimation in ocean global circulation model has been identified as a potential bias for the misrepresentation of the oxygen minimum zones. In this study, we analyze the water mass properties associated with these systems of jets using velocity and hydrographic sections. Data acquired during a dedicated cruise carried out in the western part of the basin and supplemented by cross-equatorial sections from historical cruises in the central and eastern parts are analyzed. While it is confirmed that the...
Tipo: Text
Palavras-chave: Pacific Ocean; Tropics; Jets.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00593/70490/68635.pdf

Sensitivity of near-surface Tropical Instability Waves to submonthly wind forcing in the tropical Atlantic
Provedor de dados: 5
Autores: Athie, Gabriela; Marin, Frederic; Treguier, Anne-marie; Bourles, Bernard; Guiavarc'H, Catherine.
This study demonstrates the sensitivity of the near-surface properties in the tropical Atlantic Ocean to the high-frequency of the winds in numerical simulations. At intra-seasonal timescales (2-50 days), two distinct period ranges dominate the variability in the upper ocean: periods between 2 and 20 days, which are essentially wind-forced and periods between 20 and 50 days, due mostly to Tropical Instability Waves (TIWs). Using a numerical model forced by different wind fields, it is shown that the characteristics of the intra-seasonal variability in the ocean surface mixed-layer are strongly dependent on the wind forcing. Submonthly winds are shown to force large variability in the upper ocean that can strikingly decrease the amplitude of the TIWs in the...
Tipo: Text
Palavras-chave: Equatorial Atlantic; Intra seasonal variability; Tropical instabilities; Ocean mixed layer; Sensitivity numerical experiments.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00000/11117/7967.pdf

Observations and mechanisms for the formation of deep equatorial and tropical circulation
Provedor de dados: 5
Autores: Menesguen, Claire; Delpech, Audrey; Marin, Frederic; Cravatte, Sophie; Schopp, Richard; Morel, Yves.
The Intermediate and Deep Equatorial and Tropical Circulations (DEC and DTC) consist of a complex system of zonal jets. This paper attempts at unifying existing observations and theories to present our current understanding of this jets system. Recent in‐situ observations suggesting a continuity between DEC and DTC are confronted against the various generation mechanisms that have been proposed in the literature. The key notion to differentiate these previous studies lies in the so‐called "cascade of mechanisms", i.e. the energy pathway and equilibration processes chain that lead to the jets from their initial energy source. Many studies see the Deep Equatorial Intra‐seasonal Variability (DEIV) as the initial energy source, highlighting its key role in...
Tipo: Text
Palavras-chave: Deep equatorial circulation; Deep tropical circulation; Zonal jets.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00482/59393/62159.pdf

Different secretory repertoires control the biomineralization processes of prism and nacre deposition of the pearl oyster shell
Provedor de dados: 5
Autores: Marie, Benjamin; Joubert, Caroline; Tayale, Alexandre; Zanella-cleon, Isabelle; Belliard, Corinne; Piquemal, David; Cochennec-laureau, Nathalie; Marin, Frederic; Gueguen, Yannick; Montagnani, Caroline.
Mollusca evolutionary success can be attributed partly to their efficiency to sustain and protect their soft body with an external biomineralized structure, the shell. Current knowledge of the protein set responsible for the formation of the shell microstructural polymorphism and unique properties remains largely patchy. In Pinctada margaritifera and Pinctada maxima, we identified 80 shell matrix proteins, among which 66 are entirely unique. This is the only description of the whole "biomineralization toolkit" of the matrices that, at least in part, is thought to regulate the formation of the prismatic and nacreous shell layers in the pearl oysters. We unambiguously demonstrate that prisms and nacre are assembled from very different protein repertoires....
Tipo: Text
Palavras-chave: Mantle; Mollusk shell matrix proteins; Proteome; Transcriptome; Evolution.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00118/22959/20922.pdf