Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Cratons represent the oldest preserved lithospheric domains. Their lithosphere (lithospheric mantle welded to overlying Precambrian crystalline basement) is considered to be particularly robust and long-lived due to the protecting presence of buoyant and rigid “keels” made up of residual harzburgites. Although the cratons are mostly assumed to form in the Archaean, the timing of their formation remains poorly constrained. In particular, there are very few datasets describing concurrently the age of both the crustal and mantle portions of the lithosphere. In this study, we report new U–Pb ages and Hf isotope compositions for zircons in crustal xenoliths from the Udachnaya kimberlite in the central Siberian craton; this dataset includes samples from both the upper and lower portions of the crust. The zircon ages agree well with model melt-extraction Re–Os ages on refractory peridotite xenoliths from the same pipe; taken together they allow an integrated view of lithosphere formation. Our data reveal that the present day upper crust is Archaean, whereas both the lower crust and the lithospheric mantle yield Paleoproterozoic ages. We infer that the deep lithosphere beneath the Siberian craton was not formed in a single Archaean event, but grew in at least two distinct events, one in the late Archaean and the other in the Paleoproterozoic. Importantly, a complete or large-scale delamination and rejuvenation of the Archaean lower lithosphere (lower crust and lithospheric mantle) took place in the Paleoproterozoic. This further demonstrates that craton formation can be a protracted, multi-stage process, and that the present day crust and mantle may not represent complementary reservoirs formed through the same tectono-magmatic event. Further, deep cratonic lithosphere may be less robust and long living than often assumed, with rejuvenation and replacement events throughout its history.
ISSN: 0012-821X

hal-01467648
https://hal.archives-ouvertes.fr/hal-01467648
DOI : 10.1016/j.epsl.2016.09.046

Éditeur(s) : HAL CCSD IEEE Computer Society
Résumé : 5 pages, 2 figures, composed with Microsoft Word. Proceedings of the Seventh International Conference on Document Analysis and Recognition (ICDAR 2003). Edinburgh, Écosse, 3-6 août 2003. Également disponible à l'URL : http://www.cse.salford.ac.uk/prima/ICDAR2003/Papers/0100_563_likforman_l.pdf
International audience
In the frame of a Unified Messaging System, a crucial task of the system is to provide the user with key information on every message received, like keywords reflecting the object of the message, or the name of the sender. However, in the case of facsimiles, this information is not as easy to detect as in the case of e-mails, since no standard headers are defined. The aim of the present work is to identify and extract a specific information (the name of the sender) from a fax cover page. For this purpose, methods based on image document analysis (OCR recognition, physical blocks selection), and text analysis methods (optimised dictionary lookup, local grammar rules), are implemented to work in parallel. The fusion of their results brings a more accurate guess than any of the methods would achieve separately.
Proceedings of the Seventh International Conference on Document Analysis and Recognition (ICDAR 2003)
Edinburgh, United Kingdom

hal-00328998
https://hal.archives-ouvertes.fr/hal-00328998
DOI : 10.1109/ICDAR.2003.1227724

Éditeur(s) : Elsevier Science Bv
Résumé : Small-scale fisheries have traditionally received less research effort than large-scale fisheries and are generally under-studied in Europe. In spite of their comparatively low volume of catches and economic importance, small-scale fisheries are socially important and an integral part of the European coastal zone. Considering the high heterogeneity of situations and the paucity of quantitative data, we used an analytical methodology based on the comparative method. We carried out an analysis of small-scale fisheries (SSFs) in Europe based on a selection of nine case studies. Our objective was to obtain a comprehensive description of small-scale fleets covering different areas/fisheries/species, encompassing the diversity and specific conditions under which SSFs operate, in order to demonstrate the ecological and social sustainability of this often overlooked fisheries segment. A common approach formulated so that the case studies could be compared with the case histories of other competing users, required that for each set of criteria – technical, biological, socio-economic, and institutional – a set of relevant items and indicators was established. An analysis of characteristics common to the selected case studies is conducted and an attempt made to extend our comparisons to the whole of the European Union. Our results show that (as compared with large-scale fleets, their main competitor) small-scale fleets: (i) are composed of smaller vessels and, consequently, travel lower distances to fishing grounds, and are more reliant on coastal areas; (ii) have smaller crews (although the global employment figure is similar to that of large-scale fleets in Europe); (iii) use mostly, but not exclusively, passive gears; (iv) use multi-purpose fishing approaches, and can change the fish species they target during the year; (v) have lower extraction rates; (vi) have lower total capital investments (including fishing rights), turnover and costs; and (vii) have lower fuel consumption, making them less sensitive to changing oil prices. Dependence on subsidies is lower (viii). Involvement in fisheries management is variable, conservation and access regulation measures are largely local in origin. For the selected case studies, the most significant competitors are large-scale fleets, and recreational fisheries, but other sources of interaction (water quality, invasive species, etc.) cannot be ignored.
Fisheries Research (0165-7836) (Elsevier Science Bv), 2013-02 , Vol. 140 , P. 1-13

Droits : 2012 Elsevier B.V. All rights reserved
http://archimer.ifremer.fr/doc/00118/22934/20757.pdf
DOI:10.1016/j.fishres.2012.11.008
http://archimer.ifremer.fr/doc/00118/22934/

Éditeur(s) : HAL CCSD Wiley Open Access
Résumé : International audience
Plant responses to natural enemies include formation of secondary metabolites acting as direct or indirect defenses. Volatile terpenes represent one of the most diverse groups of secondary metabolites. We aimed to explore evolutionary patterns of volatile terpene emission. We measured the composition of damage-induced volatile terpenes from 202 Amazonian tree species, spanning the angiosperm phylogeny. Volatile terpenes were extracted with solid-phase micro extraction and desorbed in a gas chromatography–mass spectrometry for compound identification. The chemical diversity of the terpene blend showed a strong phylogenetic signal as closely related species emitted a similar number of compounds. Closely related species also tended to have compositionally similar blends, although this relationship was weak. Meanwhile, the ability to emit a given compound showed no significant phylogenetic signal for 200 of 286 compounds, indicating a high rate of diversification in terpene synthesis and/or great variability in their expression. Three lineages (Magnoliales, Laurales, and Sapindales) showed exceptionally high rates of terpene diversification. Of the 70 compounds found in >10% of their species, 69 displayed significant correlated evolution with at least one other compound. These results provide insights into the complex evolutionary history of volatile terpenes in angiosperms, while highlighting the need for further research into this important class of compounds.
ISSN: 2045-7758

Droits : http://creativecommons.org/licenses/by/
hal-01296640
http://hal.upmc.fr/hal-01296640
http://hal.upmc.fr/hal-01296640/document
http://hal.upmc.fr/hal-01296640/file/ece31810.pdf
DOI : 10.1002/ece3.1810

Éditeur(s) : Pergamon-elsevier Science Ltd
Résumé : Pearl culture industry represents one of the dominant business sector of French Polynesia. However, it still entirely relies on unpredictable spat collection success. Our aim was to assess the influence of natural plankton concentration fluctuations on maturation and spawning of the black lip pearl oyster Pinctada margaritifera, during a 4 months survey conducted in Ahe atoll lagoon. Plankton concentration was assessed by chlorophyll a extraction and by microscope counts while gonadic index, gonado-visceral dry weights and histology were used to measure pearl oysters reproduction activity. We found that (i) plankton concentration fluctuations were mainly related to wind regime, (ii) gametogenesis rate was mainly related to plankton concentration, (iii) spawning occurred when maximal gonad storage was reached. (iv) plankton concentration was the main spawning synchronizing factor. These results contribute explaining P. margaritifera spat collection variability in French Polynesian atoll lagoon. (C) 2012 Elsevier Ltd. All rights reserved.
Marine Pollution Bulletin (0025-326X) (Pergamon-elsevier Science Ltd), 2012 , Vol. 65 , N. 10-12 , P. 463-470

Droits : 2012 Elsevier Ltd. All rights reserved
http://archimer.ifremer.fr/doc/00101/21201/19697.pdf
DOI:10.1016/j.marpolbul.2012.03.027
http://archimer.ifremer.fr/doc/00101/21201/

Éditeur(s) : HAL CCSD
Résumé : International audience
In this work, we propose a novel approach for the discovery of frequent patterns in a social network on the basis of both vertex attributes and link frequency. With an analogy to the traditional task of mining frequent item sets, we show that the issue addressed can be formulated in terms of a conceptual analysis that elicits conceptual links. A social-based conceptual link is a synthetic representation of a set of links between groups of vertexes that share similar internal properties. We propose a first algorithm that optimizes the search into the concept lattice of conceptual links and extracts maximal frequent conceptual links. We study the performances of our solution and give experimental results obtained on a sample example. Finally we show that the set of conceptual links extracted provides a conceptual view of the social network.
IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM)
Istanbul, Turkey

hal-00786161
https://hal.archives-ouvertes.fr/hal-00786161
DOI : 10.1109/ASONAM.2012.15

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : National audience
INTRODUCTION:The AIRBAg study screens for bronchial obstruction in dairy farmers. We present the preliminary results after one year.METHODS:A prospective screening study based on questionnaires and electronic mini-spirometry (Néo-6(®)) that includes a representative sample of dairy farmers from the departments of Morbihan and Île-et-Vilaine in Brittany. The dairy farmers had an occupational medicine appointment and, if they demonstrated at least one marker of possible bronchial obstruction (chronic cough, chronic bronchitis, dyspnoea, wheezing, FEV1/FEV6<0.8), they were referred to a pulmonologist. The data we present here were extracted from the occupational medicine appointments because the pulmonologists' appointments are still running.RESULTS:Among the 277 dairy farmers included, 125 (45%) demonstrated "possible bronchial obstruction". The total score of the CAT questionnaire was higher in these farmers (9.1±6.2 versus 5.8±4.0; P<0.0001). In multivariate analysis markers of "possible bronchial obstruction" were eczema, manual foddering and duration of mechanical straw litter spreading.CONCLUSION:Occupational medicine appointments identified markers of "possible bronchial obstruction". We will have the complete results from AIRBAg study in 2015.
ISSN: 0761-8425

hal-01117944
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01117944
DOI : 10.1016/j.rmr.2014.03.014
PUBMED : 25847201

Résumé : (i) La pertinence du thème est attestée par la richesse de la littérature internationale qui lui est consacrée. 11 convient au demeurant de noter la présence de publications de l'IFREMER dans ce même domaine. Les principaux acquis procèdent généralement d'approches descriptives, permettant de disposer à ce jour d'un inventaire quasi exhaustif des différents outils de gestion classiquement mis en oeuvre. D'ores et déjà il apparaît que la question de la transférabilité de mesures de gestion (e.g QIT, Licence, PME...) soulève plusieurs interrogations: cohérence juridique, acceptabilité, contrôle, coûts, efficience... Mais surtout, poser l'étude de la régulation en termes d'analyse du comportement d'un système élargit le champ des investigations au delà du domaine habituel de l'halieutique. C'est cette complexification de la problématique qui a principalement nourri la réflexion du groupe. (ii) En plus des travaux scientifiques produits sous ce thème, l'IFREMER, du fait de ses missions, se doit de répondre aux diverses sollicitations d'avis et d'expertise; pour ce qui concerne les ressources halieutiques cette charge incombe au Département RH. En outre, celui-ci a été amené à assurer un ensemble de tâches récursives (échantillonnage, statistiques de pêche et autres collectes de données) fortement consommatrices de temps, de moyens et contraignant à la dispersion géographique. Enfin, en tant qu'acteur du système de gestion, l'IFREMER s'est trouvé soumis à une certaine réserve quant à l'évaluation du système lui même, y compris son éventuelle remise en cause, ainsi qu'à des clauses limitatives pour l'exploitation et la valorisation des données. Aujourd'hui, près de 80 % de l'activité du Département sont dévolus à la réalisation d'études destinées à fournir des avis en réponse aux demandes émanant par exemple du CIEM, du CSTP, des COREMODE, des divers Comités Professionnels, des Etats Régionaux de la Ressource, et à s'impliquer dans des dossiers tels que les SMVM, le système de gestion en Méditerranée, les POP, les Plans Sectoriels, les conflits d'espace spécifiques (extraction de granulats, aquaculture) (1). La nature et la diversité de ces questions reflètent: -le statut d'interlocuteur privilégié de l'IFREMER; -la complexification des interactions pour l'accès ou l'usage des ressources marines; -la position centrale du thème de la régulation. [OCR NON CONTRÔLE]

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1992/rapport-4235.pdf
http://archimer.ifremer.fr/doc/00000/4235/

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
The development of inflammatory granulomas around infected Kupffer cells is necessary for hepatic parasite clearance during visceral leishmaniasis. Invariant NKT (iNKT) cells are predominant T cells in the mouse liver and can synthesize large quantities of IL-4 and IFN-γ, two cytokines involved in granuloma formation. This study analyzed the role of iNKT cells in the hepatic immune response during Leishmania donovani infection, using a murine model of wild-type (WT) and iNKT cell-deficient (Jα18⁻/⁻) C57BL/6 mice sacrificed 15, 30 or 60 days post-infection. We recorded hepatic parasite loads, cytokine expression, and analyzed granulomatous response by immunohistochemistry and hepatic immune cell infiltration by flow cytometry. Whereas WT animals rapidly controlled the infection and developed an inflammatory response associated with a massive influx of iNKT cells observed by flow cytometry, Jα18⁻/⁻ mice had significantly higher parasitic loads on all time points. This lack of control of parasite burden was associated with a delay in granuloma maturation (28.1% of large granulomas at day 60 versus 50.7% in WT). Cytokine transcriptome analysis showed that mRNA of 90/101 genes encoding chemokines, cytokines and their receptors, was underexpressed in Jα18⁻/⁻ mice. Detection of IL-4 and TNF-α by ELISA in liver extracts was also significantly lower in Jα18⁻/⁻ mice. Consistent with flow cytometry analysis, cytokinome profile in WT mice showed a bias of expression towards T cell-chemoattractant chemokines on D15, and displayed a switch towards expression of granulocytes and/or monocytes -chemoattractant chemokines on D60. In Jα18⁻/⁻ mice, the significantly lower expression of CXCL5, MIP-2 and CCL2 mRNA was correlated with a defect in myeloperoxidase positive-cell attraction observed by immunohistochemistry and with a lower granulocyte and monocyte infiltration in the liver, as shown by flow cytometry. These data indicate that iNKT cells play a role in early and sustained pro-inflammatory cytokine response warranting efficient organization of hepatic granulomas and parasite clearance.
ISSN: 1932-6203

hal-00696897
https://hal.archives-ouvertes.fr/hal-00696897
https://hal.archives-ouvertes.fr/hal-00696897/document
https://hal.archives-ouvertes.fr/hal-00696897/file/Invariant_NKT_Cells_Drive-accepted.pdf
DOI : 10.1371/journal.pone.0033413

Éditeur(s) : HAL CCSD American Chemical Society
Résumé : International audience
Cyanobacterial toxins and pesticides regularly impact freshwaters. Microcystin-LR is one of the most toxic and common cyanobacterial toxins whereas glyphosate is the active ingredient of a widely use herbicide. As filter feeders, freshwater mussels are particularly exposed. Like many native bivalve species, Unio pictorum suffers from a continuous decline in Europe. In order to get a deeper insight of its response to contaminants, U. pictorum was exposed to either 10 μg L(-1) of microcystin-LR or 10 μg L(-1) of glyphosate or a mixture of both. Proteins of the digestive glands were extracted and analyzed by DIGE. Gel analysis revealed 103 spots with statistical variations, and the response seems to be less toward glyphosate than to microcystin-LR. Specific spots have variations only when exposed to the mixture, showing that there is an interaction of both contaminants in the responses triggered. The proteins of 30 spots have been identified. They belong mostly to the cytoskeleton family, but proteins of the oxidative pathway, detoxification, and energetic metabolism were affected either by glyphosate or microcystin-LR or by the mixture. These results demonstrate the importance to study contaminants at low concentrations representative of those found in the field and that multicontaminations can lead to different response pathways.
ISSN: 1535-3893

hal-00877711
https://hal.archives-ouvertes.fr/hal-00877711
DOI : 10.1021/pr4006316
PUBMED : 23972258

Éditeur(s) : HAL CCSD Springer
Résumé : International audience
he search for frequent conceptual links (FCL) is a new network clustering approach that exploits both the network structure and the node properties. While recent works have been focused on the optimisation of the FCL extraction, no study has been conducted on the matching or the intersections between the conceptual links and the classical clustering approach which consists in extracting communities. In this paper, we focus on these two approaches. Our objective is to evaluate the possible relationships existing between FCL and communities to understand how the patterns obtained by each kind of methods may match as well as the useful knowledge resulting from the intersections of these two kinds of knowledge. For this purpose, we propose a set of original measures, based on the notion of homogeneity, assessing the level of shared information between these patterns when they are extracted from the same dataset. The measures are applied on three datasets and demonstrate the importance of considering simultaneously various kinds of knowledge and their intersections.
ISSN: 1869-5450

hal-01312313
https://hal.archives-ouvertes.fr/hal-01312313
DOI : 10.1007/s13278-014-0197-1

Résumé : Les granulats (sables et graviers) sont une matière première recherchée principalement pour la construction et pour des projets de poldérisation et de renforcement de plages. Du fait de la diminution des ressources terrestres, la pression augmente dans de nombreux pays membres du CIEM pour répondre à la demande avec des matériaux d'origine marine. Cette évolution conduit à augmenter les risques de conflit entre l'industrie d'extraction de granulats marins et les autres utilisateurs du milieu marin, en particulier l'industrie de la pêche.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00103/21459/19040.pdf
http://archimer.ifremer.fr/doc/00103/21459/

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Fish mucus has important biological and ecologicalroles such as defense against fish pathogens andchemical mediation among several species. A non-targetedliquid chromatography–mass spectrometry metabolomicapproach was developed to study gill mucus of eight butterflyfishspecies in Moorea (French Polynesia), and theinfluence of several fish traits (geographic site and reefhabitat, species taxonomy, phylogeny, diet and parasitismlevels) on the metabolic variability was investigated. Abiphasic extraction yielding two fractions (polar and apolar)was used. Fish diet (obligate corallivorous, facultativecorallivorous or omnivorous) arose as the main driver ofthe metabolic differences in the gill mucus in both fractions,accounting for 23% of the observed metabolic variabilityin the apolar fraction and 13% in the polar fraction.A partial least squares discriminant analysis allowed us toidentify the metabolites (variable important in projection,VIP) driving the differences between fish with differentdiets (obligate corallivores, facultative corallivores andomnivorous). Using accurate mass data and fragmentationdata, we identified some of these VIP as glycerophosphocholines,ceramides and fatty acids. Level of monogeneangill parasites was the second most important factor shapingthe gill mucus metabolome, and it explained 10% of themetabolic variability in the polar fraction and 5% in theapolar fraction. A multiple regression tree revealed that themetabolic variability due to parasitism in the polar fractionwas mainly due to differences between non-parasitized andparasitized fish. Phylogeny and butterflyfish species werefactors contributing significantly to the metabolic variabilityof the apolar fraction (10 and 3%, respectively) buthad a less pronounced effect in the polar fraction. Finally,geographic site and reef habitat of butterflyfish species didnot influence the gill mucus metabolome of butterflyfishes.
ISSN: 0722-4028

hal-01563312
https://hal-univ-perp.archives-ouvertes.fr/hal-01563312
DOI : 10.1007/s00338-017-1554-0

Éditeur(s) : HAL CCSD
Résumé : National audience
Designing systems able to interact with students in a natural manner is a complex and far from solved problem. A key aspect of natural interaction is the ability to understand and appropriately respond to human emotions. This paper details our response to the continuous Audio/Visual Emotion Challenge (AVEC'12) whose goal is to predict four affective signals describing human emotions. The proposed method uses Fourier spectra to extract multi-scale dynamic descriptions of signals characterizing face appearance, head movements and voice. We perform a kernel regression with very few representative samples selected via a supervised weighted-distance-based clustering, that leads to a high generalization power. We also propose a particularly fast regressor-level fusion framework to merge systems based on different modalities. Experiments have proven the efficiency of each key point of the proposed method and our results on challenge data were the highest among 10 international research teams.
IHM'14, 26e conférence francophone sur l'Interaction Homme-Machine
Lille, France

hal-01089628
https://hal.archives-ouvertes.fr/hal-01089628
https://hal.archives-ouvertes.fr/hal-01089628/document
https://hal.archives-ouvertes.fr/hal-01089628/file/p44-nicole.pdf

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Banana has been a main agricultural product in the French West Indies (Guadeloupe and Martinique) since the 1960s. This crop requires the intensive use of pesticides to prevent attacks by insect pests. Chlorinated pesticides, such as hexachlorocyclohexane (HCH), chlordecone and dieldrin, were used until the beginning of the 1990s, resulting in a generalized diffuse contamination of the soil and water in the areas of banana production, hence the need to develop solutions for cleanup of the polluted sites. The aims of this work were (i) to assess lindane degradation in soil slurry microcosms treated with lindane at 10 mg/L and (ii) to detect the catabolic genes involved in the HCH degradation pathway. The soil slurry microcosm system showed a 40 % lindane degradation efficiency at the end of a 30-day experiment. Lower lindane removal was also detected in the abiotic controls, probably caused by pesticide adsorption to soil particles. Indeed, the lindane concentration decreased from 6000 to 1330 ng/mL and from 800 to 340 ng/mL for the biotic and abiotic soils, respectively. Nevertheless, some of the genes involved in the HCH degradation pathway were amplified by polymerase chain reaction (PCR) from crude deoxyribonucleic acid (DNA) extracted from the Guadeloupe agricultural soil, suggesting that HCH degradation is probably mediated by bacteria closely related to the family Sphingomonadaceae.
ISSN: 0944-1344

hal-01545905
https://hal.archives-ouvertes.fr/hal-01545905
DOI : 10.1007/s11356-015-5875-7

Éditeur(s) : HAL CCSD Société géologique de France
Résumé : New radiolarian assemblages of Late Jurassic age were extracted from seven chert localities of the basement comp ex of La Desirade Island (Guadeloupe), the oldest geological unit of the Lesser Antilles arc and the eastern Caribbean region. These fauna range in age from Kimmeridgian or early Tithonian to early or early late Tithonian, showing that La Desirade cherts are not all coeval, contrary to what was established by previous studies. Furthermore, the close spatial association of cherts and volcanic elements composed of basaltic flows and volcaniclastics suggests a mixed setting of hydrothermal siliceous deposits and biogenous sedimentation consistent with an arc-related oceanic setting rather than an ophiolite-type oceanic crust. As the Youngest age is obtained to the northwest of the basement complex where as older data are found to the southeast, it also Suggests that La Desirade basement complex may have undergone some structural stacking consistent with an accretion-type geodynamic getting. Our biochronological data provide a preliminury try tectonic model of an eastward subduction zone for Lesser Antilles arc basement emplacement during the Mesozois.
EISSN: 1777-5817

hal-00445252
https://hal.archives-ouvertes.fr/hal-00445252
DOI : 10.2113/gssgfbull.180.5.399

Éditeur(s) : HAL CCSD
Résumé : International audience
We present a study on the optimasation of the number of messages for medical diagnosis over wireless sensors networks (WSNs). We suggest distributed algorithms to diagnosis some diseases while monitoring a patient. Then, we compare the number of messages needed to make a decision between the algorithms. In our approach, each sensor will make some computations in order to participate to the decision. Indeed, some computation and collaboration tasks are performed over the sensors and the final diagnosis is performed in a distributed way. During the experimentation of our algorithms, we used a real data flow extracted from hospital monitoring.
Proceedings of the 14th IEEE Symposium on Computers and Communications (ISCC 2009), July 5-8, Sousse, Tunisia
Sousse, Tunisia

hal-00519593
https://hal.archives-ouvertes.fr/hal-00519593

Éditeur(s) : ESA Publication
Résumé : Satellite remote sensing has emerged as an essential and necessary observing system to acquire global information about the state of the ocean. Complemented with in situ observing networks, the ultimate goals are to be able to make accurate estimates of selected key sets of geophysical variables, with the intention of either making operational predictions across time and spatial boundaries, or advancing fundamental knowledge through development of empirical relationships and theoretical models. For satellite oceanography, improvements are then constantly being sought in our understandings of the geophysical processes, the sensor physics, the electromagnetic and microwave properties and interactions at the complex air-sea interface. Challenges appear as unlimited as the variety of sea surface dynamics and boundary layer meteorological conditions with their broad range of spatial and temporal scales across the globe. To face these challenges, numerous efforts took places over the passed decade to build an ever-increasing quality, quantity, duration and integration of ocean observations. In parallel, simulation capabilities largely improved. All these efforts are then all critically calling for improved methodologies to better structure the wealth of information that is made readily accessible. This latter aspect is a very demanding new component for future multidisciplinary scientific research. Major innovations to consolidate sensor data repositories, to automate tailored queries, to extract, reveal and quantify relationships will then closely associate computer science developments and applied statistics with comprehensive theoretical and experimental thematic studies.
Proceedings of OceanObs'09: Sustained Ocean Observations and Information for Society (ESA Publication), 2010

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00029/14046/11241.pdf
DOI:10.5270/OceanObs09.pp.12
http://archimer.ifremer.fr/doc/00029/14046/

Résumé : Ce travail porte sur l'inhibition de l'acier C38 en milieu acide HC1 1M par les extraits alcaloïdes issus de 2 plantes : aspidosperma album et geissospermum laeve. Biodégradables et respectueux de l'environnement, les alcaloïdes pourraient être utilisés temporairement pour prévenir la corrosion de l'acier C39 avec des taux d'inhibition supérieurs à ceux décrits dans la littérature. Dans la première partie du travail, l'influence de la concentration, du temps d'immersion et de la température sur le processus de corrosion de l'acier C38 en milieu HC1 1M en absence de polarisation et spectroscopie d'impédance électrochimique. Les analyses de surface effectuées par microscopie électronique a balayage montrent la présence d'une couche constituée d'un mélange d'oxyde de fer incorporant les alcaloïdes et qui conduit à la diminution de la vitesse de corrosion. La deuxième partie de ce travail a été consacrée à l'isolement des alcaloïdes des deux extraits afin de déterminer le ou les alcaloïdes responsables de l'activité inhibitrice et ainsi remonter aux mécanismes d’adsorption. Il a été montré que l'alcaloïde majoritaire des extraits est responsable de l'inhibition
This work is devoted to the corrosion inhibition of C38 steel in 1M HCL acid medium by alkaloids extracts from two plants : aspidosperma album and geissospermum laeve. Biodegradable and environmentally friendly, alkaloids could be used temporarily to prevent the corrosion of C38 steel with inhibition rates higher than those described in the literature. The first part of this work studies the influence of concentration, immersion time and temperature on the corrosion inhibitor by electrochemical measurements : polarization curves and electrochemical impedance spectroscopy. The surface analyses conducted by scanning electron microscopy showed the presence of a layer composed of an iron oxide mixture incorporating alkaloids extracts and which leads to the decrease of the corrosion rate. The second part of this work was devoted to the isolation of alkaloids of two extracts in order to determine the alkaloids responsible of the inhibitory activity and thus to determine the adsorption mechanisms. It was showed that the major alkaloids of two extracts is responsible of the inhibition activity

http://www.theses.fr/2013AGUY0578/document

Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé :  
We report the isolation and identification of a new quassinoid named simalikalactone E (SkE), extracted from a widely used Amazonian antimalarial remedy made out of Quassia amara L. (Simaroubaceae) leaves. This new molecule inhibited the growth of Plasmodium falciparum cultured in vitro by 50%, in the concentration range from 24 to 68 nM, independently of the strain sensitivity to chloroquine. We also showed that this compound was able to decrease gametocytemia with a 50% inhibitory concentration sevenfold lower than that of primaquine. SkE was found to be less toxic than simalikalactone D (SkD), another antimalarial quassinoid from Q. amara, and its cytotoxicity on mammalian cells was dependent on the cell line, displaying a good selectivity index when tested on nontumorogenic cells. In vivo, SkE inhibited murine malaria growth of Plasmodium vinckei petteri by 50% at 1 and 0.5 mg/kg of body weight/day, by the oral or intraperitoneal routes, respectively. The contribution of quassinoids as a source of antimalarial molecules needs therefore to be reconsidered.
ISSN: 0066-4804

hal-01032126
https://hal.archives-ouvertes.fr/hal-01032126
DOI : 10.1128/AAC.00951-09