Éditeur(s) : Elsevier Science Bv
Résumé : Although Ni isotopes have been shown to be significantly fractionated in terrestrial samples, their use in continental environmental studies has not yet been evaluated. The present study focuses on an ultramafic (UM) massif (Barro Alto, Goias, Brazil) because such areas are naturally rich in Ni. We present developed lateritic weathering profiles. The goal of the study is to evaluate the potential of using Ni isotopes in environmental continental studies by combining its isotopic signature with mineralogy, in order to better understand the geochemical cycling of Ni in UM settings during weathering. As such, Ni isotope values were measured in samples from the Barro Alto UM complex in the main stages of the lateritic weathering profile of UM rocks, including bedrock, ores (saprolitic and lateritic samples) and soil. The mineralogical composition of the samples, with a focus on the different Ni-bearing minerals, was also determined to decipher the potential links between isotopic fractionation and weathering dynamics. Isotopic signatures (δ60Ni) from the natural Ni geochemical cycle include: bedrock samples (δ60Ni = 0.28 ± 0.08‰), ore samples (saprolitic and lateritic, δ60Ni from -0.60 to 0.30‰) and soil samples (δ60Ni from -0.19 to -0.02‰). An overall trend of heavier isotope depletion was observed in the solid phase during weathering (Δ60NiSoil-Bedrock = -0.47‰). The mineralogical results were consistent with the literature and showed that the mineralogy of the lateritic part and soil was dominated by Fe-oxides, whereas clay minerals were the primary Ni phase scavengers in the saprolitic part of the profile. Thus, the formation of Ni-bearing clay minerals and Fe-oxides appeared to lead to depletion in heavier isotopes, which indicates preferential export of heavy isotopes in the dissolved phase. This result is consistent with isotopic signatures measured in the exchangeable pool of the solid phase (Δ60Niexch-total up to 0.47‰), and Ni isotopes appear to be a promising tracer to better understand the biogeochemical Ni cycling on the Earth’s surface.
Chemical Geology (0009-2541) (Elsevier Science Bv), 2015-05 , Vol. 402 , P. 68-76

Droits : 2015 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/00254/36553/35098.pdf
DOI:10.1016/j.chemgeo.2015.02.039
http://archimer.ifremer.fr/doc/00254/36553/

Éditeur(s) : HAL CCSD Wiley
Résumé :  
Pollination ecology and reproductive success of Jack-in-the-pulpit (Arisaema triphyllum) were studied in two natural populations in Québec, Canada. Individual A. triphyllum plants can be of three types: male, female or bisexual. In both populations studied, the presence of bisexual inflorescences was not negligible (13%), where 'female' and 'male' bisexual plants were categorised according to the relative number of stamens and ovaries. 'Male bisexual' plants produce only pollen and 'female bisexual' plants produce only fruit. Hence, A. triphyllum is a true dioecious plant, as each plant only reproduces through either the male or the female function. 'Female bisexual' plants were equivalent to female plants in terms of visitation rate by insects, fructification rate and production of berries and seeds. Neither agamospermy in female plants nor self-pollination in 'female bisexual' plants was found, thus A. triphyllum relies on insects for cross-pollination. Despite the long flowering cycle, a low visitation rate was documented: only 20-40% of inflorescences were visited, according to gender, by a mean of 1.5 insects. In this study, Mycetophilidae represented the most generically diversified and abundant family, as well as the most efficient insect pollinator, especially the genera Docosia and Mycetophila.
ISSN: 1435-8603

hal-01032127
https://hal.archives-ouvertes.fr/hal-01032127
DOI : 10.1111/j.1438-8677.2009.00192.x

Éditeur(s) : Université de Nantes
Résumé : The reproductive cycle of Megathura crenulata was documented and quantification of oocyte lipid reserves with lipo-specific stains was explored in both this species and in Crassostrea gigas. The necessity of providing food to female broodstock C. gigas in spring was re-evaluated, because subsequent larval and post-larval rearing performance was not affected by broodstock starvation during conditioning. Developmental study of the organs responsible of particle processing in C. gigas allowed the identification of critical stages related to the ontogenesis of each organ, as well as a better understanding of the evolution of these organs, highly-modified in the Ostreidae. Ciliary type identification and mucocyte mapping from post-larval to adult stage showed that the heterorhabdic specialization precedes the anatomic formation of gill plicae specific to this condition.
Le cycle reproducteur de Megathura crenulata a été documenté et la quantification des réserves ovocytaires par des colorants lipospécifiques a été tentée, sans résultats concluants pour cette espèce, ni pour Crassostrea gigas. L'intérêt d'une alimentation des géniteurs femelles C. gigas au printemps est re-évalué, car la performance ultérieure des élevages larvaires et post-larvaires n'a pas été affectée par le jeûne imposé lors du conditionnement. L'étude du développement des organes impliqués dans le traitement des particules chez C. gigas a permis d'identifier des stades critiques associés à l'ontogenèse de chaque organe, ainsi qu'une meilleure compréhension de l'évolution de ces organes si particuliers chez les Ostreidae. L'examen des types ciliaires et la cartographie des mucocytes de la post-larve à l'adulte ont montré que la spécialisation hétérorhabdique précède même la formation anatomique des plis branchiaux caractéristiques de cette condition.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2005/these-1371.pdf
http://archimer.ifremer.fr/doc/00000/1371/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The study of decay resistance in wood is of interest for wood end-users but also for the global carbon balance since wood biodegradation is a key driver of forest ecosystem functioning through its impacts on carbon and nutrient cycling. We studied the density and wood extractive contents in order to understand decay resistance against soil microflora after 90 days exposure of sapwood and heartwood from three Neotropical wood species known for their decay resistance: Bocoa prouacensis, Vouacapoua americana, Inga alba. Decay resistance was correlated with density more than wood extractive content. The results highlighted different decay resistance strategies. In B. prouacensis, both sapwood and heartwood were highly resistant due to the high density and high content of antifungal wood extractives. In V. americana heartwood, decay resistance was due to the high synergistic-acting wood extractive content. Conversely, with the least dense wood species I. alba, we found that decay resistance was due to the antifungal wood extractives synthesized early in the sapwood. In conclusion, we showed that the three wood species with the same level of heartwood decay resistance performance had different decay resistance strategies according to the anatomic and defensive wood traits.
ISSN: 0964-8305

hal-01321162
https://hal.archives-ouvertes.fr/hal-01321162
https://hal.archives-ouvertes.fr/hal-01321162/document
https://hal.archives-ouvertes.fr/hal-01321162/file/Art_Amusant_al_Diversity_decay_resistance_strategies_Int.Biodet.Biodegr._2014.pdf
DOI : 10.1016/j.ibiod.2014.06.012

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Acquiring information is indisputably energy-consuming and conversely, the availability of information permits greater efficiency. Strangely, the scientific community long remained reluctant to establish a physical equivalence between the abstract notion of information and sensible thermodynamics. However, certain physicists such as Szilard and Brillouin proposed: (i) to give to information the status of a genuine thermodynamic entity (k B T ln2 joules/bit) and (ii) to link the capacity of storing information inferred from correlated systems, to that of indefinitely increasing organization. This positive feedback coupled to the self-templating molecular potential could provide a universal basis for the spontaneous rise of highly organized structures, typified by the emergence of life from a prebiotic chemical soup. Once established, this mechanism ensures the longevity and robustness of life envisioned as a general system, by allowing it to accumulate and optimize microstate-reducing recipes, thereby giving rise to strong nonlinearity, decisional capacity and multistability. Mechanisms possibly involved in priming this cycle are proposed.
ISSN: 0169-6149

inserm-00826658
http://www.hal.inserm.fr/inserm-00826658
http://www.hal.inserm.fr/inserm-00826658/document
http://www.hal.inserm.fr/inserm-00826658/file/OLEB-2013.pdf
DOI : 10.1007/s11084-013-9329-2

Éditeur(s) : HAL CCSD Blackwell Publishing
Résumé : International audience
Differentiating between forced regressive deposits from deglacial periods inhigh latitude domains and forced regressive deposits from the onset of glacialperiods in low latitude domains is fundamental for the accurate interpretationof glacial cycles within the geological record and then for thereconstruction of palaeogeography and palaeo-climate. A forced regressivedeglacial sequence is documented from the Lake Saint-Jean basin (Quebec,Canada). In this area, the Late Pleistocene to Holocene sediments haverecorded the Laurentide ice sheet retreat accompanied by the invasion ofmarine waters (Laflamme Gulf) from ca 129 cal kyr BP. Subsequently, fluviodeltaicand coastal prograding wedges were deposited; they followed thebase-level fall due to glacio-isostatic rebound. This succession, representinga transition from glacial to post-glacial periods within a previously glaciatedarea, was investigated through recent mapping, preserved landforms, faciesanalysis, and new optical stimulated luminescence and radiocarbon dates.Three basin-scale geological sections share a common lower part made ofisolated ice-contact fan deposits overlying bedrock. Throughout the entirebasin, ice-contact fans are capped by glacimarine muds. Above, fluvial andcoastal prograding systems were deposited and evolved through four steps:(i) deltaic systems progressively increased in width; (ii) coastal influence onsedimentation increased; (iii) hydrographic drainage systems became moreorganised; and (iv) deltas graded from steep (Gilbert delta) to low-angle foresets(mouth-bar delta). Deposited during the base-level fall from glacioisostaticrebound, the complete succession has been designated as a singlefalling stage system tract referred to as a deglacial falling stage system tract.It is representative of a deglaciation sequence in areas previously covered byice during glacial periods (i.e. medium to high latitude domains). Diagnosticcriteria are provided to identify such a deglacial falling stage system tract inthe geological record, which may aid identification of previously unknownglacial cycles.
ISSN: 1469-3496

insu-01184731
https://hal-insu.archives-ouvertes.fr/insu-01184731
DOI : 10.1111/sed.12196

Résumé : Depuis octobre 1992 une étude est conduite pour analyser les mécanismes de recrutement du stock de crevettes pénéïdes (Pelloeus subtilis) du plateau guyanais. En effet, le cycle de cette espèce étant très court, ces mécanismes conditionnent directement les rendements de la flottille industrielle crevettière guyanaise. Les variabilités intra et inter-annuelles du recrutement sont considérées comme très fortes, aussi une optimisation de la gestion de cette pêcherie passe par une meilleure compréhension de ces mécanismes et notamment de leurs facteurs de variation. Cette étude s'intègre dans un programme de coopération régionale entre l'IFREMER et le Ministère de l'Agriculture, de l'Elevage et des Pêches du Surinam financé par des fonds FEDER et du FIC, et elle est menée par l'IFREMER dans la Zone Economique française et le laboratoire du Département des pêches du Surinam sur le plateau de ce pays. Ce programme prévoit une série de huit campagnes en mer qui seront conduites en parallèle par chacun des deux laboratoires Français et Surinamien sur les plateaux de Guyane (campagnes RESUBGUY) et du Surinam (campagnes RESUBSUR) afin d'analyser le phénomène de recrutement sur la plus large échelle possible d'observation (plateau guyano-surinamien). Deux campagnes annuelles ont été programmées pour chaque pays, en mai et en octobre. La périodicité de ces campagnes est fonction des résultats des travaux conduits par l'IFREMER et l'ORSTOM sur la phase pré-recrutée de Penaeus subtilis qui ont mis en évidence deux principales périodes annuelles distinctes de recrutement (avril-mai; septembre-octobre). Cette campagne est la troisième de la série initiée en octobre 1992. L'étude n'est pas limitée à l'examen des seules captures de crevettes Penaeus subtilis, puisqu'elle inclue également l'analyse de la composition des prises accessoires des crevettiers. Les "by-catches" considérées dans ce travail sont surtout représentées par la crevette "sea-bob", Xiphopenaeus kroyeri, ainsi que par les principales espèces de poissons d'intérêt commercial (ou ayant une forte probabilité de le devenir dans un futur proche). Enfin, une attention particulière a aussi été portée sur les captures accidentelles de tortues marines afin d'en estimer l'importance réelle.

Droits : 1993 Ifremer
http://archimer.ifremer.fr/doc/00070/18148/15707.pdf
http://archimer.ifremer.fr/doc/00070/18148/

Éditeur(s) : Gauthier-Villars
Résumé : The seasonal variations of total dissolved copper were surveyed during one year (1983/1984) in the Aulne estuary (Western Brittany, France), an ecosystem with a high rate of water renewal. Copper in filtered water samples (after and without acidification) was determined after preconcentration on Chelex 100, and the eluates were analyzed by graphite furnace atomic absorption spectroscopy. The concentrations of free and complexed copper were then plotted versus chlorosity. Globally, the total dissolved copper concentrations tend to decrease with salinity. The role of physicochemical parameters such as pH and suspended matter (adsorption-desorption mechanisms) on dissolved copper content is shown to be significant. With a variable intensity, desorption (release) takes place in summer and in autumn, while adsorption is observed at very low chlorosity in winter. The dissolved copper concentrations in the Aulne estuary (0.26 to 2.52-mu-g.l-1, with the highest values in autumn) are similar to most estuarine copper values. The proportion of complexed species ranges from 4 to 69% (average of 27%).
Les variations saisonnières des concentrations en cuivre dissous dans l'estuaire de l'Aulne (Bretagne occidentale) ont été mesurées au cours d'un cycle annuel (1983/1984). Les concentrations en cuivre libre et celles en cuivre complexé ont été suivies séparément en fonction de la chlorosité, un paramètre conservatif. Les profils obtenus pour le cuivre total dissous montrent généralement une décroissance des teneurs en métal des eaux douces aux eaux marines, tout en restant supérieures à celles de la droite théorique de mélange. On montre le rôle fondamental de la variation du pH concomitante de celle de la matière en suspension (mécanisme d'adsorption-désorption) dans l'évolution des teneurs en cuivre dissous. Ce processus agit plus ou moins intensément dans le sens de la désorption (été, automne) ou de l'adsorption (hiver aux faibles chlorosités). Dans l'ensemble, les teneurs en cuivre total dissous (de 0,26 à 2,52 J.lg.l- 1 , les valeurs automnales étant les plus élevées) sont comparables à celles de nombreux autres écosystèmes estuariens, avec un taux de complexation compris entre 4 et 69% (moyenne de 27% ).
Oceanologica Acta (0399-1784) (Gauthier-Villars), 1991 , Vol. 14 , N. 5 , P. 445-457

Droits : Gauthier-Villars
http://archimer.ifremer.fr/doc/00103/21377/18977.pdf
http://archimer.ifremer.fr/doc/00103/21377/43066.pdf
http://archimer.ifremer.fr/doc/00103/21377/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : In recent years, the use of fads in Martinique has evolved from an experimental stage to a productive one. This transformation results in the pitching up of operational device park by the regional fishery committee. Nevertheless, this technical change in fishing practices is not implemented in a homogeneous way all around the island; some differences exist especially between the Atlantic and the Caribbean coasts. From surveys carried out during an annual cycle on two main landing sites, this study describes the pelagic fishing activity around fads and in the open sea. A comparison of fishing strategies adopted in different places as well as an analysis of the results obtained by the fishing units in terms of species (size of catches and daily yields) allow to describe the progress made in the implementation adoption of this new fishing practice. For several fishermen, fishing around fads has become an exclusive job, practised all year round. For others, fads is used in addition to traditional fishing activity on flotsam, "Miquelon" fishing and keeps a seasonal character.Original Abstract: Au cours des recentes annees, l'utilisation des DCP en Martinique est passee du stade experimental au stade operationnel. Cette mutation se traduit par la prise en charge du parc de dispositifs operationnels par le comite regional des peches. Toutefois, l'adoption de cette nouvelle technique d'exploitation ne s'effectue pas de facon homogene dans toutes les communes de l'ile, des differences existent notamment entre les cotes Atlantique et Caraibe. A partir d'enquetes effectuees pendant un cycle annuel, sur deux principaux points de debarquement, cette etude decrit l'activite de peche des poissons pelagiques avec ou sans DCP. Une comparaison des strategies de peche developpees dans les differents sites ainsi qu'une analyse des resultats obtenus par les unites de peche en termes d'especes, de taille des captures, de rendement journalier permettent de decrire la progression differenciee de l'adoption de cette nouvelle activite halieutique. Pour certains pecheurs, la peche sous DCP est devenue un metier exclusif, pratique tout au long de l'annee. Pour d'autres, le DCP est utilise en complement de l'activite traditionnelle de peche sous bois derivants, " peche a Miquelon ", et conserve un caractere saisonnier.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15298/12657.pdf
http://archimer.ifremer.fr/doc/00042/15298/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Abstract View references (38)Silicalite-1 (S-1) and ZSM-5 membranes prepared by secondary growth on tubular ceramic supports were tested using a pervaporation set up for the desalination of aqueous solutions containing NaCl in concentrations corresponding to brackish (0.3-1wt%), sea (3.5wt%) and brine (7.5-15wt%) water. ZSM-5 membranes delivered higher water fluxes when compared with S-1 membranes due to enhanced hydrophilicity of the Al-rich zeolite structure leading to fluxes as high as 11.5kgm -2h -1 for 0.3wt% NaCl feed solutions at 75°C. At higher salt concentration the water flux decreased alongside with the salt rejection rate, however the hydrophilic ZMS-5 membrane became more susceptible to performance loss, particularly at high temperatures. Detailed stability experiments carried out for up to 560h showed the dissolution of both S-1 and ZSM-5 top layers. This was attributed to the combined effects of ion exchange and water dissolution mechanisms. Interesting though, the MFI structure zeolite was still observed on the XRD patterns whilst EDX depth profile showed the presence of silica up to 30μm depth into the support. These results suggest the formation/infiltration of a compact amorphous phase in the substrate, derived from the aggregation of the dissolved silicate species and possibly together with the arrangement of MFI nano-slabs during the desalination tests. Despite generating lower water fluxes, the S-1 membrane exhibited relatively high robustness under the long term testing conditions which included temperature cycling, delivering salt rejections from initial >99% to <80% at the end of the testing period (560h). © 2012 Elsevier B.V.
ISSN: 0376-7388

hal-01683201
https://hal.univ-antilles.fr/hal-01683201
DOI : 10.1016/j.memsci.2012.05.074

Éditeur(s) : Elsevier
Résumé : The Danube Canyon is a large shelf-indenting canyon that has developed seaward of the late Pleistocene paleo-Danube valley. Mechanisms of canyon evolution and factors that controlled it are revealed by analyzing the morphology and the sedimentary structure of the canyon, as well as the main features of the continental margin around the canyon. This is based on investigation by swath bathymetry in the canyon area combined with different types of seismic data. The canyon is a major erosional trough with a flat bottom cut by an entrenched axial thalweg. The thalweg path varies from highly meandering to fairly straight in relation to the local gradient. Segments of the canyon are characterized by specific morphology, orientation and gradient along the axial thalweg. We interpret these segments in terms of canyon maturity. The sedimentary structure of the canyon documents an older phase of erosion followed by partial infilling, and thus attests for repeated cycles of canyon development. Canyon morphology is interpreted as a result of erosive sediment flows along the entrenched axial thalweg that caused downcutting into the canyon bottom and instability of the canyon walls, and hence enlargement of the canyon and expansion by headward erosion. During the last lowstand level of the Black Sea the canyon was located in an area of high sediment supply close to the paleo-Danube River mouths. This is indicated by buried fluvial channels on the shelf and by a wave-cut terrace associated with a water level situated about - 90 m below the present level. We infer that erosive flows in the canyon resulted from hyperpycnal currents at the river mouths, probably favored by the low salinity environment that characterized the Black Sea during lowstand times. Other mechanisms could have contributed to trigger sediment failure along the canyon, such as instability related to the presence of shallow gas, or the effect of a deep fault.
Marine Geology (0025-3227) (Elsevier), 2004-05 , Vol. 206 , N. 1-4 , P. 249-265

Droits : 2004 Elsevier B.V. All rights reserved
http://archimer.ifremer.fr/doc/2004/publication-476.pdf
DOI:10.1016/j.margeo.2004.03.003
http://archimer.ifremer.fr/doc/00000/476/

Éditeur(s) : HAL CCSD National Research Council Canada
Résumé : International audience
In French Guiana, inflorescences of Philodendron squamiferum Poepp. (Araceae) were regularly visited by the scarab beetle Cyclocephala simulatrix Hölne and (Scarabaeidae, Coleoptera) occasionally by Cyclocephala tylifera Hölne. The flowering cycle lasted 2 days, and the protogynous inflorescence exhibited features typical of beetle pollination (floral chamber, food rewards, flower heating). The spadix temperature was measured during the entire flowering cycle in French Guiana and at the Montreal Botanical Garden. Both sets of measurements gave a similar temperature pattern. The spadix warmed up twice at the beginning of each evening with no notable heat production between the two peaks. These two temperature peaks were well synchronized with the arrival and departure of beetles
ISSN: 0008-4026

hal-01202724
https://hal.archives-ouvertes.fr/hal-01202724

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
Symbioses with the dinoflagellate Symbiodinium are widespread among marine invertebrates and protists, especially in nutritionally demanding habitats, such as tropical coral reefs, where they play a major role in ecosystem survival. Moreover, apart from corals and sea anemones, many of the Symbiodinium species and clades involved in these partnerships remain to be characterized. This study provides new insights into nudibranch and sponge associations with Symbiodinium by sequencing regions of the Symbiodinium 28S rDNA and the host mitochondrial COI oxidase. Specimens were sampled between 2011 and 2013 from locations around the islands of Moorea and Tahiti, French Polynesia. Our results revealed that some of the sponges and nudibranchs harbored typical Symbiodinium from clade B or C while others harbored new, undescribed Symbiodinium-like dinoflagellates. A detailed analysis of the different life stages of the nudibranch Phestilla lugubris and of its specific coral prey, Porites rus, suggests a prey-predator horizontal transfer of the symbiont and its vertical inheritance from the parent to the eggs.
Les symbioses à zooxanthelles, dinoflagellés du genre Symbiodinium, sont largement répandues chez les invertébrés marins et les protozoaires, notamment dans les eaux oligotrophes, où ils jouent un rôle important dans la survie des récifs coralliens. De plus, excepté chez les coraux et les anémones, les différentes espèces et clades de Symbiodinium impliqués dans ces associations restent à être caractérisés. Notre étude, grâce à l’utilisation des marqueurs génétiques 28S ADNr des Symbiodinium et la sous-unité 1 de la cytochrome oxydase mitochondriale (COI) de l’hôte, procure de nouvelles données quant aux associations des éponges et des nudibranches avec les Symbiodinium. L’échantillonnage a eu lieu autour de Moorea et de Tahiti (Polynésie française), entre 2011 et 2013. Nos résultats révèlent que certaines espèces d’éponges et de nudibranches possèdent les clades B et C communément retrouvés, chez les coraux notamment, alors que d’autres présentent de nouveaux dinoflagellés « Symbiodinium-like ». Une analyses détaillée des Symbiodinium à différents stades du cycle de vie du nudibranche corallivore Phestilla lugubris et de son corail hôte Porites rus suggèrent l’existence d’un transfert horizontal de Symbiodinium proie–prédateur et un transfert vertical du parent P. lugubris à ses œufs.
ISSN: 1631-0691

hal-01145518
https://hal.archives-ouvertes.fr/hal-01145518
DOI : 10.1016/j.crvi.2015.01.005

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : National audience
Les leishmanioses sont des maladies parasitaires à transmission vectorielle observées sur tous les continents, à l’exception de l’Amérique du Nord et de l’Australie. Nous focaliserons ici sur la leishmaniose viscérale méditerranéenne due à Leishmania infantum et dont l’incidence annuelle est estimée entre 1200 et 2000 cas. Son cycle biologique est zoonotique avec un réservoir animal essentiellement canin. Les récentes observations épidémiologiques sont rapportées ici, notamment la mise en évidence du portage humain asymptomatique et l’extension de la zone endémique de la leishmaniose canine. La prise en charge thérapeutique de la leishmaniose viscérale méditerranéenne du patient immunocompétent fait essentiellement appel à l’amphotéricine B liposomale. Le débat existe toujours sur la pertinence d’une prophylaxie secondaire ou des traitements itératifs à chaque rechute chez le patient co-infecté par le VIH. Summary Leishmaniasis are protozoan infections transmitted by the bite of the sandflies, widely reported except in North-America and Australia. Here, we focus on mediterranean visceral leishmaniasis due to Leishmania infantum, with an estimated annual incidence of 1200–2000 cases. Its biological cycle is zoonotic and mainly involves the canine reservoir. The recent epidemiological observations are reported here, particularly the asymptomatic carriage but also the extension of the canine enzooty. Regarding treatment of immunocompetent patients, the drug of choice for mediterranean visceral leishmaniasis is liposomal amphotericin B. In case of HIV-Leishmania co-infection, the interest of secondary prophylaxis is still in debate
ISSN: 2210-6545

hal-01225489
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01225489
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01225489/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01225489/file/Mise%20au%20point%20et%20actualit%C3%A9s%20sur%20la%20leishmaniose%20visc%C3%A9rale%20m%C3%A9diterran%C3%A9enne.pdf
DOI : 10.1016/j.antinf.2014.12.005

Résumé : After 12 years of a difficult start, the sea bass (Dicentrarchus labrax) breeding projects are multiplying. Faced with the constraints presented by the sites used in the past, farming at sea seems to offer conditions more conducive to the growth and survival of the animals. The zootechnical data from the farm makes it possible to link the rate of growth and the thermal profile of the site. Risks and uncertainties still weigh heavily on aquafarming projects, but solutions such as insurance are helping to improve their economic feasibility. The economic and financial analysis comes up with good overall profitability of the project, even if the duration of the breeding cycle and the necessity to ensure a progressive increase in operating capacity make the start-up phase long and not very lucrative.
(OCR non controlé) Après 12 années d'un démarrage difficile, les projets d'élevage du loup (Dicentrarchus labrax) se multiplient. Face aux contraintes que présentent les sites utilisés par le passé, l'élevage en mer semble offrir des conditions plus favorables à la croissance et à la survie des animaux. Les données zootechniques de l'élevage permettent de mettre en relation la vitesse de croissance et le profil thermique du site. Risques et incertitudes pèsent encore lourdement sur les projets aquacoles, mais des solutions telles que l'assurance contribuent à améliorer leur faisabilité économique. L'analyse économique et financière conclut à une bonne rentabilité globale du projet même si la durée du cycle d'élevage et la nécessité d'assurer une montée en puissance progressive de l'exploitation rendent la phase de démarrage longue et peu rémunératrice.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1989/rapport-2417.pdf
http://archimer.ifremer.fr/doc/00000/2417/

Éditeur(s) : HAL CCSD Elsevier
Résumé : The seismic characteristics of focused fluid-related features such as pockmarks and carbonate build-ups on the Nigerian continental slope have been investigated using complementary seismic data sets (reprocessed 3D exploration data and 2D Very High Resolution hull-mounted and near-bottom seismic data) coupled with the results of previous studies (sedimentological, geotechnical and geochemical analyses).The results show different types of fluid-related features within the hemipelagic phase of long duration (∼1 Myr) Turbidite/Hemipelagic cycles. They are the product of the disturbance of the hosting sediments following two main distinct processes: (1) no or low sediment deposition caused by fluid escape associated with seafloor settlement (benthic fauna, carbonate precipitation, gas hydrate formation) and (2) post-depositional erosion, caused either by fluid release (dewatering from underlying features such as channels and upward migration from a deep source) or by collapse (destabilisation of gas hydrates). The temporal evolution reveals a decrease in fluid flow during the hemipelagic deposition as witnessed by the decrease in methanogenic activity and by gas hydrate destabilisation. The spatial distribution of fluid-related features seems to be controlled by the type of fault (small fault or structural lineament).
ISSN: 0264-8172

hal-01685513
https://hal.archives-ouvertes.fr/hal-01685513
DOI : 10.1016/j.marpetgeo.2017.10.004

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We sought transversotrematid trematodes from French Polynesian fishes by examining 304 individual scaled fishes of 53 species from seven families known to harbour the family elsewhere. A single species was found at two locations in the Tuamotus Archipelago on two species of Chaetodontidae (Chaetodon auriga and Chaetodon ephippium) and one species of Lutjanidae (Lutjanus gibbus). The species closely resembles Transversotrema borboleta Hunter & Cribb, 2012 from chaetodontids and lutjanids of the northern Great Barrier Reef (GBR) but differs from it consistently in 8 base positions of ITS2 rDNA. This level of variation exceeds that between some clearly morphologically distinct pairs of species of Transversotrema and the form from French Polynesia is thus interpreted as a distinct, though cryptic, species and named Transversotrema polynesiae n. sp. The new species forms part of a complex of species, here characterised as the T. borboleta complex, associated with chaetodontids and lutjanids in the tropical Indo-West Pacific. Most of the putative species within this complex are yet to be described. Comparison of identical numbers of matched samples of fishes from French Polynesia, Heron Island (southern GBR) and Lizard Island (northern GBR) revealed 1, 4 and 10 species of Transversotrema respectively suggesting that the French Polynesian fauna is depauperate for this family. In addition to those species apparently missing from suitable hosts in French Polynesia, several species from further west infect fishes (especially Nemipteridae) that are themselves absent from French Polynesia. This dramatic east–west decline in richness contrasts strongly with what is known for monogeneans, which appear to maintain their richness over the same scale, and is more precipitate than is known for other groups of trematodes. The decline might be explained in part by the absence of the as yet unknown first intermediate hosts in French Polynesia. However, we predict that it is explained by other life cycle traits. We hypothesise that the characters of large short-lived cercariae, short-lived miracidia, the absence in the life-cycle of second intermediate hosts that are capable of transporting the species, and definitive and first intermediate hosts that have limited vagility combine to give marine Transversotrematidae limited dispersal capacity and a propensity for localised speciation.
ISSN: 1383-5769

hal-01333467
https://hal-univ-perp.archives-ouvertes.fr/hal-01333467
DOI : 10.1016/j.parint.2013.11.009

Éditeur(s) : HAL CCSD Wiley
Résumé : Proper estimates of decomposition are essential for tropical forests, given their key role in the global carbon (C) cycle. However, the current paradigm for litter decomposition is insufficient to account for recent observations and may limit model predictions for highly diverse tropical ecosystems. In light of recent findings from a nutrient-poor Amazonian rainforest, we revisit the commonly held views that: litter traits are a mere legacy of live leaf traits; nitrogen (N) and lignin are the key litter traits controlling decomposition; and favourable climatic conditions result in rapid decomposition in tropical forests. Substantial interspecific variation in litter phosphorus (P) was found to be unrelated to variation in green leaves. Litter nutrients explained no variation in decomposition, which instead was controlled primarily by nonlignin litter C compounds at low concentrations with important soil fauna effects. Despite near-optimal climatic conditions, tropical litter decomposition proceeded more slowly than in a climatically less favourable temperate forest. We suggest that slow decomposition in the studied rainforest results from a syndrome of poor litter C quality beyond a simple lignin control, enforcing energy starvation of decomposers. We hypothesize that the litter trait syndrome in nutrient-poor tropical rainforests may have evolved to increase plant access to limiting nutrients via mycorrhizal associations.
ISSN: 0028-646X

hal-01032400
https://hal.archives-ouvertes.fr/hal-01032400
DOI : 10.1111/j.1469-8137.2010.03483.x

Éditeur(s) : Pergamon-elsevier Science Ltd
Résumé : Society's needs for a network of in situ ocean observing systems cross many areas of earth and marine science. Here we review the science themes that benefit from data supplied from ocean observatories. Understanding from existing studies is fragmented to the extent that it lacks the coherent long-term monitoring needed to address questions at the scales essential to understand climate change and improve geo-hazard early warning. Data sets from the deep sea are particularly rare with long-term data available from only a few locations worldwide. These science areas have impacts on societal health and well-being and our awareness of ocean function in a shifting climate. Substantial efforts are underway to realise a network of open-ocean observatories around European Seas that will operate over multiple decades. Some systems are already collecting high-resolution data from surface, water column, seafloor, and sub-seafloor sensors linked to shore by satellite or cable connection in real or near-real time, along with samples and other data collected in a delayed mode. We expect that such observatories will contribute to answering major ocean science questions including: How can monitoring of factors such as seismic activity, pore fluid chemistry and pressure, and gas hydrate stability improve seismic, slope failure, and tsunami warning? What aspects of physical oceanography, biogeochemical cycling, and ecosystems will be most sensitive to climatic and anthropogenic change? What are natural versus anthropogenic changes? Most fundamentally, how are marine processes that occur at differing scales related? The development of ocean observatories provides a substantial opportunity for ocean science to evolve in Europe. Here we also describe some basic attributes of network design. Observatory networks provide the means to coordinate and integrate the collection of standardised data capable of bridging measurement scales across a dispersed area in European Seas adding needed certainty to estimates of future oceanic conditions. Observatory data can be analysed along with other data such as those from satellites, drifting floats, autonomous underwater vehicles, model analysis, and the known distribution and abundances of marine fauna in order to address some of the questions posed above. Standardised methods for information management are also becoming established to ensure better accessibility and traceability of these data sets and ultimately to increase their use for societal benefit. The connection of ocean observatory effort into larger frameworks including the Global Earth Observation System of Systems (GEOSS) and the Global Monitoring of Environment and Security (GMES) is integral to its success. It is in a greater integrated framework that the full potential of the component systems will be realised. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.
Progress In Oceanography (0079-6611) (Pergamon-elsevier Science Ltd), 2011-10 , Vol. 91 , N. 1 , P. 1-33

Droits : 2011 Published by Elsevier Ltd. All rights reserved.
http://archimer.ifremer.fr/doc/00044/15557/15923.pdf
DOI:10.1016/j.pocean.2011.05.001
http://archimer.ifremer.fr/doc/00044/15557/

Éditeur(s) : HAL CCSD Météo et Climat
Résumé : International audience
The Convective and Orographically- induced Precipitation Study (COPS) is a coordinated international project, comprised of an observational field campaign and a research programme aiming to advance the quality of fore- casts of orographically-induced pre- cipitation by four-dimensional obser- vations and modelling of its life cycle. The COPS field campaign took place during June-July-August 2007 over eastern France and south-western Germany. Its main objective was to provide an unprecedented comprehen- sive set of in situ and remotely-sensed meteorological observations of the entire depth of the troposphere. After a short overview of the project, the paper focuses on the French contribution to the COPS field phase, describes the experimental setup and highlights some key observations.
L’étude des précipitations convectives induites par l’orographie (Cops selon l’acronyme anglais) est un projet inter- national coordonné qui comprend une campagne d’observations de terrain et un programme scientifique et qui vise à améliorer la qualité des prévisions des précipitations orographiques convectives à la fois par l’observation quadridimensionnelle et la modélisa- tion de leur cycle de vie. La campagne de terrain s’est déroulée en juin-juillet- août 2007 sur l’est de la France et le sud-ouest de l’Allemagne. Son objectif majeur était de fournir un jeu d’obser- vations météorologiques, in situ et à distance, aussi complet que possible et sur toute la profondeur de la colonne troposphérique.Après une brève revue d’ensemble du projet, l’article se concentre sur la contribution française à la campagne Cops, décrit le dispositif expérimental mis en œuvre et met en valeur quelques observations clés.
ISSN: 0026-1181

insu-01504075
https://hal-insu.archives-ouvertes.fr/insu-01504075
https://hal-insu.archives-ouvertes.fr/insu-01504075/document
https://hal-insu.archives-ouvertes.fr/insu-01504075/file/meteo_2009_64_32.pdf
DOI : 10.4267/2042/23632