Éditeur(s) : INRA : Institut National de la Recherche Agronomique Université des Antilles. Service commun de la documentation University of Suriname
Extrait de : 52e congrès annuel de la Société caribéenne des plantes alimentaires / 52nd annual meeting of the Caribbean food crops society (CFCS), du 10 au 16 juillet 2016. INRA, CFCS
Description : The import data from the Ministry of Trade indicates that Suriname has increased pesticides imports over the last five years. According to research evidence, as much as 80% of potential production in various crops including rice would be lost as a result of agricultural pests without crop protection measures. Even though the benefits of chemical pesticides use are clear, negative health and environmental impacts of their use are also evident. In lieu of this information a study was conducted to determine small rice farmers? perceptions on their knowledge of pesticide use, and safety of pesticides in rice production For this investigation a questionnaire was adapted from a pesticide use survey to generate and collect meaningful data on perceptions of small rice farmer?s knowledge and practices related to pesticide use and safety aspects in rice production in Nickerie. The sample population consisted of 200 small rice farmers.?The collected data was analyzed using SPSS and Microsoft Excel. Descriptive statistics and correlation were used to describe the data. Findings reveal that the rice farmers are male, on the average older than 50 years and have more than 15 years of experience with rice production. Results also reveal that farmers perceive the recommended dosage as too little and therefore increase the dosage. They often mix different types of pesticides and do not use all of their protective equipment while spraying. Based on the results it is recommended to develop pesticide policies to stimulate farmers to practice safe pesticide use in Suriname. Les données d'importation du ministère du commerce indiquent que le Surinam a augmenté des importations de pesticides au cours des cinq dernières années. Selon des preuves de recherches, pas moins de 80% de production potentielle dans diverses cultures comprenant le riz serait perdu en raison des parasites agricoles sans mesures de protection des cultures. Quoique les avantages d'une utilité chimique de pesticides soient clairs, la santé et les impacts sur l'environnement négatifs de leur utilisation est également évident. Au lieu de cette information une étude a été entreprise pour déterminer les perceptions des petits agriculteurs de riz sur leur connaissance d'utilisation de pesticide, et la sécurité des pesticides dans la production de riz. Pour cette enquête un questionnaire a été adapté d'une enquête d'utilisation de pesticide pour se produire et rassembler des données significatives sur des perceptions de la connaissance du petit agriculteur de riz et des pratiques s'est rapporté aux conditions de sécurité d'utiliser-et de pesticide dans la production de riz dans Nickerie. La population témoin s'est composée de 200 petits agriculteurs de riz. Les données rassemblées ont été analysées utilisant SPSS et Microsoft Excel. Des statistiques descriptives et la corrélation ont été employées pour décrire les données. Les résultats indiquent que les agriculteurs de riz sont masculins, les plus vieux que 50 années moyennes et ont plus de 15 ans d'expérience avec la production de riz. Les résultats indiquent également que les agriculteurs perçoivent le dosage recommandé en tant que trop peu et augmentent donc le dosage. Ils souvent mélangent différents types de pesticides et n'utilisent pas tout leur équipement de protection tout en pulvérisant. Basé sur les résultats on lui recommande de développer des politiques de pesticide pour stimuler des agriculteurs pratiquer l'utilisation sûre de pesticide au Surinam.
Siècle(s) traité(s) : 21
Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V16248
V16248

Éditeur(s) : INRA : Institut National de la Recherche Agronomique CIRAD : Centre de Coopération Internationale en Recherche Agronomique pour le Développement Université des Antilles. Service commun de la documentation
Extrait de : 52e congrès annuel de la Société caribéenne des plantes alimentaires / 52nd annual meeting of the Caribbean food crops society (CFCS), du 10 au 16 juillet 2016. INRA, CFCS
Description : Acknowledging the contribution of agriculture to global changes and its negative impacts on the environment, it is now seen as unavoidable for it to participate to the ecological transition. This research aims to understand the performativity of legal texts. This performativity does not only reveal the institutions? approach of the model to implement. It also aims to change, in the meantime, the reality (Ambroise et al., 2015). The objective of this research is to stress the importance of concepts? definitions in policies implementation when agricultural system reframing is at stake, and to highlight an uncertain use of words may produce. However, little attention is given to the choice of terms concerning the definition of a greener agriculture in official texts: terms are often mixed up without any clarification. Applying content analysis to official documents, we provide an analytical grid to grasp in what extent the unclear use of words and what they namely designate, lead to ambiguous policies eluding aspects of the concept of agroecology underlined by researchers or associations. We also shed light on the local appropriation process of the concept and its specification in the French Indies. Reconnaissant la contribution de l'agriculture aux changements globaux et à ses impacts négatifs sur l'environnement, on le voit maintenant comme inévitable pour qu'il participe à la transition écologique. Objectifs de ces recherches pour comprendre le performativity des textes juridiques. Ce performativity indique non seulement l'approche des établissements du modèle à l'instrument. Il vise également à changer, dans le même temps, la réalité (Ambroise et autres, 2015). L'objectif de cette recherche est de souligner l'importance des définitions des concepts dans l'exécution de politiques quand le système agricole reframing est en jeu, et accentuer une utilisation incertaine des mots peut produire. Cependant, peu d'attention est accordée au choix des termes au sujet de la définition d'une agriculture plus verte en textes officiels : des termes sont souvent mélangés sans n'importe quelle clarification. S'appliquant à l'analyse du contenu aux documents officiels, nous fournissons une grille analytique à la prise dans quelle ampleur l'utilisation peu claire des mots et ce qu'ils à savoir indiquent, mènent aux politiques ambiguës éludant des aspects du concept de l'agroécologie souligné par des chercheurs ou des associations. Nous avons également jeté la lumière sur le processus local d'appropriation du concept et de ses spécifications dans les Antilles françaises.
Siècle(s) traité(s) : 21
Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V16255
V16255

Éditeur(s) : ECMEA : Etudes Croisées des Mondes Européens et Américains CRILLASH : Centre de Recherches Interdisciplinaires en Lettres, Langues, Arts et Sciences Humaines Université des Antilles. Service commun de la documentation
Extrait de : "Terres promises, représentations et imaginaires" : colloque, du 25 au 27 novembre 2015. Université des Antilles
Description : Une collection éparse de longs poèmes inspirés, une dizaine de romans compliqués à souhait mais sources de reconnaissances enviées, une production théâtrale plutôt modeste, la direction d'une revue à haute prétention dans la Martinique étriquée des années 70, une thèse de philosophie soutenue en Sorbonne livrée dans une forme déconcertante (pour ne pas dire désinvolte), cinq essais poétiques de plus en plus aventureux, quelques prises de positions vigoureuses sur la situation internationale, deux ou trois libelles coécrits avec des amis disparates, une anthologie poétique de bric et de broc, l'oeuvre d'Édouard Glissant qui s'étend sur 59 ans et des milliers de pages, présente une dimension qui impressionne. Ce caractère foisonnant suggère le changement et peut-être même la métamorphose car, tout au long de sa vie, d'un genre à l'autre, l'auteur fait l'expérience de lieux et de contextes fort divers, du Lamentin à Paris, de New York à Tokyo, de Bâton Rouge à Tunis. Cette communication prend pour prétexte le premier poème d'envergure paru en 1955, Les Indes, pour arpenter le parcours ultérieur du poète penseur autour de thèmes, de concepts et de slogans, jamais définis dans les règles de l'art, toujours revisités sous différentes formes et très diversement interprétés, l'homme ne suscitant jamais le consensus. Antillanité, Relation Démesure, Chaos, Tout-monde, Créolisation ? Les toutes dernières années de sa vie le verront couronné comme l'apôtre d'une audacieuse théorie de la mondialisation et de la diversité des langues, naviguant avec ces mots comme autant de balises et d'étapes curieuses dans son voyage aux Indes promises. Sans jamais prétendre en donner une synthèse exhaustive et cohérente, le projet est ici d'esquisser un cap, une orientation dominante à partir de l'examen de la langue d'écriture et des multiples déclarations du poète à ce sujet. L'occasion rêvée pour un linguiste natif du même pays de repartir en quête des promesses tenues ou non et des découvertes réelles ou imaginaires d'un texte abondant.
Siècle(s) traité(s) : 20
Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V16089
V16089

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We present new groundmass K–Ar ages obtained using the Cassignol–Gillot technique, together with whole-rock major and trace elements, from Les Saintes islands (Terre-de-Haut and Terre-de-Bas). They are located along the northern Lesser Antilles inner arc, between Basse-Terre Island (western Guadeloupe) to the North and Dominica Island to the South. Ages reveal that the main volcanic phase in Terre-de-Haut occurred between 2.98 ± 0.04 and 2.00 ± 0.03 Ma, and show that the onset of sub-aerial volcanism in Terre-de-Haut is slightly older (~ 0.2 Myr) than that of northern Basse-Terre. Volcanism in Les Saintes resumed to the west, with the rapid construction of Terre-de-Bas Island at 0.888 ± 0.009 Ma. Major elements analyses show that most lavas from Les Saintes belong to a sub-alkaline medium-K magmatic series and are mainly andesites, with relatively rare basaltic andesites and dacites. Rare earth elements spectra reveal a strong enrichment in light elements, as observed for Dominica lavas, and significantly higher than observed for Basse-Terre lavas. Noticeably, Terre-de-Bas spectra display more enriched patterns relative to those from Terre-de-Haut lavas, suggesting a lower degree of partial melting or a stronger sedimentary component incorporated to the subducting slab. Overall, geochemical signatures of Les Saintes and Dominica magmas display common characteristics, which we interpret as reflecting strong petrogenetic affinities, while both are significantly different from that of Basse-Terre lavas. Finally, this study provides a precise timing of subaerial volcanism of Les Saintes Islands, which can be used to better constrain through time the development of the tectonic half-graben where these islands lie, which is part of the arc-parallel en-echelon faults system accommodating the oblique convergence of the North American plate from Montserrat to Dominica. In addition, these results reveal that the initiation of Terre-de-Haut volcanism is presently the oldest dated volcanism from the northern part of the Lesser Antilles active arc.
ISSN: 0377-0273

hal-01067336
https://hal.archives-ouvertes.fr/hal-01067336

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
BACKGROUND: Estrogen receptors (ER) α and β are found in both women and men in many tissues, where they have different functions, including having roles in cell proliferation and differentiation of the reproductive tract. In addition to estradiol (E2), a natural hormone, numerous compounds are able to bind ERs and modulate their activities. Among these compounds, phytoestrogens such as isoflavones, which are found in plants, are promising therapeutics for several pathologies. Glyceollins are second metabolites of isoflavones that are mainly produced in soybean in response to an elicitor. They have potentially therapeutic actions in breast cancer by reducing the proliferation of cancer cells. However, the molecular mechanisms driving these effects remain elusive. METHODS: First, to determine the proliferative or anti-proliferative effects of glyceollins, in vivo and in vitro approaches were used. The length of epithelial duct in mammary gland as well as uterotrophy after treatment by E2 and glyceollins and their effect on proliferation of different breast cell line were assessed. Secondly, the ability of glyceollin to activate ER was assessed by luciferase assay. Finally, to unravel molecular mechanisms involved by glyceollins, transcriptomic analysis was performed on MCF-7 breast cancer cells. RESULTS: In this study, we show that synthetic versions of glyceollin I and II exert anti-proliferative effects in vivo in mouse mammary glands and in vitro in different ER-positive and ER-negative breast cell lines. Using transcriptomic analysis, we produce for the first time an integrated view of gene regulation in response to glyceollins and reveal that these phytochemicals act through at least two major pathways. One pathway involving FOXM1 and ERα is directly linked to proliferation. The other involves the HIF family and reveals that stress is a potential factor in the anti-proliferative effects of glyceollins due to its role in increasing the expression of REDD1, an mTORC1 inhibitor. CONCLUSION: Overall, our study clearly shows that glyceollins exert anti-proliferative effects by reducing the expression of genes encoding cell cycle and mitosis-associated factors and biomarkers overexpressed in cancers and by increasing the expression of growth arrest-related genes. These results reinforce the therapeutic potential of glyceollins for breast cancer.
ISSN: 1478-811X

hal-01560288
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01560288
DOI : 10.1186/s12964-017-0182-1
PUBMED : 28666461

Éditeur(s) : HAL CCSD Wiley
Résumé : SUBSURF
International audience
Similarity of form between subaerial and submarine landscapes affected by erosion could suggest similarities in the process of erosion, such as by runoff and sedimentary flows, respectively. On the other hand, if aspects of form vary, its characteristics may be used to identify the environmental origin of erosion. Towards these goals, this contribution addresses the morphology of submarine volcanoes (seamounts) with widely differing histories of erosion. One set from the Pacific Ocean never exposed above sea level includes Cretaceous-age seamounts near Hawai'i (including Apu'upu'u Seamount), two seamounts of < 3 Ma in age near a mid-ocean ridge and the 11-4 Ma Jasper Seamount. These seamounts are all isolated from continents and hence from any erosion associated with mass wasting of unstable terrigenous deposits. In such isolated submarine environments, surfaces erode slowly from in situ weathering, mass wasting and scouring by sedimentary flows initiated by slope failure in pelagic or bedrock materials. The Pacific seamounts are compared with Valencia Seamount in the western Mediterranean, exposed subaerially for 100-400 k.y. during the Messinian Salinity Crisis before 5 Ma. Multibeam and deeply towed sidescan sonar data of Valencia Seamount reveal features typical of subaerial erosion of volcanic islands, such as canyons and relatively uneroded sectors (planezes) between them. Using a simple topographical reconstruction, the apparent erosion depth typically reaches 100 m within canyons and up to 180 m in places. Whereas the younger Pacific seamounts do not show these erosional features, the much older Cretaceous seamounts do have channels, which in one example suggests up to 200 m of incision. Both Valencia and Apu'upu'u seamounts have channel longitudinal profiles that are steep and typically linear to concave upwards. The erosion depth of Apu'upu'u Seamount is significant, despite the seamount's persistent submarine environment, because of its greater age, steeper flanks and greater contributing areas to channels compared with Valencia Seamount. These results illustrate that the channel morphology resulting from submarine erosion can become similar to that produced by subaerial erosion given sufficient time.
ISSN: 0950-091X

hal-00411425
https://hal.archives-ouvertes.fr/hal-00411425
DOI : 10.1111/j.1365-2117.2008.00355.x

Éditeur(s) : HAL CCSD Elsevier
Résumé : We report a preliminary analysis on the relationships between drainage basin structure and genetic structure of populations of the European vector of fasciolosis, Galba truncatula. In the study area, 251 snails belonging to 12 populations were collected along different ditches of a same river network. Each snail was genotyped at six variable microsatellite loci. Our results show that all sample sites are characterized by a low level of polymorphism and a very high and significant heterozygote deficiency. Our data reveal a significant genetic differentiation, even at a small scale, and failed to delimit clear patterns of isolation by euclidian distance. Our study shows that genetic differentiation significantly increases with hydrographic distance along the streams (p < 0.002), in consistence with the hypothesis that dispersion along the stream is dependent on the direction of water flow. This study shows that relationships can exist between the organization of the hydrological network and population biology of a disease vector, which has strong potential applications to drainage network management issues.
ISSN: 1567-1348

hal-00496374
https://hal.archives-ouvertes.fr/hal-00496374
DOI : 10.1016/j.meegid.2010.01.005

Éditeur(s) : HAL CCSD AGU and the Geochemical Society
Résumé : International audience
Although magmatism may occur during the earliest stages of continental rifting, its role in strain accommodation remains weakly constrained by largely 2-D studies. We analyze seismicity data from a 13 month, 39-station broadband seismic array to determine the role of magma intrusion on state-of-stress and strain localization, and their along-strike variations. Precise earthquake locations using cluster analyses and a new 3-D velocity model reveal lower crustal earthquakes beneath the central basins and along projections of steep border faults that degas CO2. Seismicity forms several disks interpreted as sills at 6-10 km below a monogenetic cone field. The sills overlie a lower crustal magma chamber that may feed eruptions at Oldoinyo Lengai volcano. After determining a new ML scaling relation, we determine a b-value of 0.87±0.03. Focal mechanisms for 65 earthquakes, and 13 from a catalogue prior to our array reveal an along-axis stress rotation of ∼60° in the magmatically active zone. New and prior mechanisms show predominantly normal slip along steep nodal planes, with extension directions ∼N90°E north and south of an active volcanic chain consistent with geodetic data, and ∼N150°E in the volcanic chain. The stress rotation facilitates strain transfer from border fault systems, the locus of early-stage deformation, to the zone of magma intrusion in the central rift. Our seismic, structural, and geochemistry results indicate that frequent lower crustal earthquakes are promoted by elevated pore pressures from volatile degassing along border faults, and hydraulic fracture around the margins of magma bodies. Results indicate that earthquakes are largely driven by stress state around inflating magma bodies.
ISSN: 1525-2027

hal-01667198
https://hal.archives-ouvertes.fr/hal-01667198
DOI : 10.1002/2017GC007027

Éditeur(s) : HAL CCSD Mineralogical Society of America
Résumé : International audience
Accessory phases are important hosts of trace elements; allanite may contain >90% of the REE in a bulk rock. The mobility and redistribution of several trace elements, notably HREE, Th, U, and Y is thus controlled by reactions involving allanite and other REE phases, as well as several rock-forming minerals. As these elements are commonly concentrated in mature elastic sediments, a suite of impure quartzite was studied. Two eclogite facies samples from the Monometamorphic Cover Complex of the Sesia Zone (Western Italian Alps) are presented in some detail, as they reveal a remarkably rich spectrum of reaction relationships that involve REE phases.;Two allanite-forming reactions were inferred from textures and phase compositions;(1) monazite + Ca-silicate(?) + fluid -> allanite + apatite + thorite;;(2) monazite + thorite + Ca-silicate(?) + fluid -> Th-rich allanite + auerlite +/- apatite.;Petrographic observations and thermodynamic models suggest that allanite entered the HP assemblage at similar to 530 degrees C and 17-18 kbar during prograde metamorphism.;In one sample, allanite is rimmed by epidote rich in Y and HREE that grew at the expense of xenotime. Two net transfer reactions were derived;(3) xenotime + allanite + fluid -> Y-rich epidote + apatite + thorite;;(4) xenotime + allanite + fluid -> Y-rich epidote + aeschynite + thorite + (phosphate?).;Textural relationships and trace element analyses of coexisting allanite/monazite and xenotime/Y-rich epidote reveal systematic partitioning of the REE. Partition coefficients for the HREE are compatible with equilibrium fractionation, whereas those for the LREE show patterns that seem to be inherited from the precursor phases, in this case zircon with variable LREE composition.
ISSN: 0003-004X

hal-00745674
https://hal.archives-ouvertes.fr/hal-00745674
DOI : 10.2138/am.2012.3832

Éditeur(s) : Elsevier
Résumé : The New Caledonia blue shrimp Litopenaeus stylirostris is commercially produced under semi-intensive rearing conditions. The size of the farming earthen ponds (5–10 ha) and the subsequent production constraints make it difficult to use them as experimental units for random experiments. Moreover, since every pond has its own characteristics, ponds' effects cannot be ruled out, thus making it hard to define true replicates. In order to design future experiments under conditions resembling those used in production, we evaluated the possible use of floating cages as experimental units with the aim of assessing treatment effects with a reasonable statistical power. To this end, two sets of floating cages were placed respectively in two different ponds in a commercial farm. In both cases the zootechnical conditions in the cages were similar in post-larvae origin, management, and diet and feeding regime. The aim of the study was to evaluate on a technical basis the possibility of rearing shrimps in floating cages set up in earthen ponds and to assess this method from a statistical standpoint. Shrimps reared in and outside the cages showed comparable growth and survival rates. The variability in the zootechnical parameters between cages, expressed as the estimated coefficient of variation (CV) for survival rate, total final biomass (g), final body weight (g), daily increment in body weight (g day− 1) and FCR were 11.0, 13.7, 4.4, 5.4, and 7.0%, respectively. On the basis of these figures, we calculated for a given statistical power (80%) the number of replicates (cages) that would be required to reveal significant differences between two treatments, at a 5% level of significance. We found that for expected differences of 20% from the control mean, 3 and 6 floating cages per treatment would be reasonable to determine statistical differences for growth parameters and survival rate, respectively. Moreover, we showed a significant pond effect in regard to survival and growth between the two sets of cages. These results illustrated the within-farm variability among the ponds, and confirmed that the specific characteristics of each pond from the same farm make it difficult to use the ponds themselves as experimental units. The study demonstrates that rearing in floating cages is an economical, powerful and sensitive experimental tool for shrimp culture studies specifically carried out under conditions close to semi-intensive production.
Aquaculture (0044-8486) (Elsevier), 2008-07 , Vol. 279 , N. 1-4 , P. 63-69

Droits : 2008 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2008/publication-4363.pdf
DOI:10.1016/j.aquaculture.2008.03.053
http://archimer.ifremer.fr/doc/00000/4363/

Éditeur(s) : Elsevier
Résumé : A study of organic carbon mineralization from the Congo continental shelf to the abyssal plain through the Congo submarine channel and Angola Margin was undertaken using in situ measurements of sediment oxygen demand as a tracer of benthic carbon recycling. Two measurement techniques were coupled on a single autonomous platform: in situ benthic chambers and microelectrodes, which provided total and diffusive oxygen uptake as well as oxygen microdistributions in porewaters. In addition, sediment trap fluxes, sediment composition (Org-C, Tot-N, CaCO3, porosity) and radionuclide profiles provided measurements of, respectively input fluxes and burial rate of organic and inorganic compounds. The in situ results show that the oxygen consumption on this margin close to the Congo River is high with values of total oxygen uptake (TOU) of 4 +/- 0.6, 3.6 +/- 0.5 mmol m(-2) d(-1) at 1300 and 3100m depth, respectively, and between 1.9 +/- 0.3 and 2.4 +/- 0.2 mmol m(-2) d(-1) at 4000 m depth. Diffusive oxygen uptakes (DOU) were 2.8 +/- 1.1, 2.3 +/- 0.8, 0.8 +/- 0.3 and 1.2 +/- 0.1 mmol m(-2) d(-1), respectively at the same depths. The magnitude of the oxygen demands on the slope is correlated with water depth but is not correlated with the proximity of the submarine channel-levee system, which indicates that cross-slope transport processes are active over the entire margin. Comparison of the vertical flux of organic carbon with its mineralization and burial reveal that this lateral input is very important since the sum of recycling and burial in the sediments is 5-8 times larger than the vertical flux recorded in traps. Transfer of material from the Congo River occurs through turbidity currents channelled in the Congo valley, which are subsequently deposited in the Lobe zone in the Congo fan below 4800 m. Ship board measurements of oxygen profiles indicate large mineralization rates of organic carbon in this zone, which agrees with the high organic carbon content (3%) and the large sedimentation rate (19 mm y(-1)) found on this site. The Lobe region could receive as high as 19 mol C m(-2) y(-1), 1/3 being mineralized and 2/3 being buried and could constitute the largest depocenter of organic carbon in the South Atlantic.
Deep Sea Research Part II: Topical Studies in Oceanography (0967-0645) (Elsevier), 2009-11 , Vol. 56 , N. 23 , P. 2223-2238

Droits : 2009 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2009/publication-7316.pdf
DOI:10.1016/j.dsr2.2009.04.005
http://archimer.ifremer.fr/doc/00000/7316/

Éditeur(s) : Elsevier
Résumé : During the Fanindien 2006 cruise of R/V 'Beautemps-Beaupre', high resolution multibeam bathymetry, sub-bottom profiling and sediment coring was carried out along the East African margin, offshore Tanzania and Mozambique (Indian Ocean). The newly acquired data reveal the presence of a giant deep-sea valley (the Tanzania channel) that is more than 10 km wide at 4000 m water depth, along the continental rise. The valley remains similar to 70 m deep and 7 km wide at 800 km from the Tanzania coast. Morphological comparison with worldwide submarine channels show that the Tanzania channel is one of the largest known submarine valleys. This discovery brings new light on development of submarine valleys that drain sediments originated from the East African Rift System (EARS) highlands (i.e. the Tanzania channel and its neighbor Zambezi channel located similar to 1000 km southward). Both of the systems have a morphology markedly different to the classical sinuous, V-shaped channels located at similar latitudes (e.g. the Zaire or Amazon channels). Their submarine drainage system consists of a downslope converging tributary canyons joining a central trunk channel in the continental rise. The presence of such giant deep-sea drainage systems is probably linked to a strong structural control on the sediment pathway, associated to a massive sediment transfer towards the Indian Ocean in relation with the tectonic activity of the East African Rift System (i.e. the uplift periods trough mid-Miocene and Plio-Pleistocene times) and its interplay with the East African equatorial climate changes.
Marine Geology (0025-3227) (Elsevier), 2008-12 , Vol. 255 , N. 3-4 , P. 179-185

Droits : 2008 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/00324/43491/42958.pdf
DOI:10.1016/j.margeo.2008.09.002
http://archimer.ifremer.fr/doc/00324/43491/

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
Knowing the slip amplitudes that large earthquakes produced in prehistorical times is one key to anticipate the magnitude of large forthcoming events. It is long known that the morphology is preserving remnants of paleoearthquake slips in the form of fault-offset landforms. However, the measured offsets that can be attributed to the most recent paleoearthquakes are generally few along a fault, so that they rarely allow recovering the slip distributions and largest slips of these earthquakes. We acquired ~1 m resolution airborne lidar data on a 30 km stretch of a fast-slipping strike-slip fault (eastern Hope Fault, New Zealand) located in a region of high alluvial dynamics where landforms are rapidly evolving. Data analysis reveals >200 offset landforms; only 30% allow a good to moderate quality offset measurement. From these good to moderate quality measures, we recover the slip-length distributions and largest slips of the four most recent large paleoearthquakes and find evidence of 4–6 prior events. The record suggests that large earthquake slip recurred in multiples of about 4 m along the 30 km stretch. Although they have larger uncertainties, the more numerous lower-quality offsets that we also measured reveal a similar earthquake slip record. This shows that, although offset landforms are partly degraded in dynamically active landscapes, they store valuable information on paleoearthquake slips. This information might be recovered provided that the morphology is analyzed at high resolution and " continuously " over a significant fault length. Remote lidar data are powerful to perform such analyses.
ISSN: 2169-9313

insu-01469219
https://hal-insu.archives-ouvertes.fr/insu-01469219
https://hal-insu.archives-ouvertes.fr/insu-01469219/document
https://hal-insu.archives-ouvertes.fr/insu-01469219/file/Manighetti_et_al-2015-Journalsur Geophysical_Research__Solid_Earth.pdf
DOI : 10.1002/2014JB011787

Éditeur(s) : Wiley-blackwell
Résumé : The reef fauna connectivity of the West Indian Ocean (WIO) is one of the least studied globally. Here we use genetic analyses of the grouper Epinephelus merra (Bloch 1793) to determine patterns of connectivity and to identify barriers to dispersal in this WIO marine area. Phylogeographic and population-level analyses were conducted on cytochrome b sequences and microsatellites (13 loci) from 557 individuals sampled in 15 localities distributed across the West Indian Ocean. Additional samples from the Pacific Ocean were used to benchmark the WIO population structure. The high level of divergence revealed between Indian and Pacific localities (of about 4.5% in sequences) might be the signature of the major tectonic and climatic changes operating at the Plio-Pleistocene transition, congruently with numerous examples of Indo-Pacific speciation. In comparison, the E. merra sequences from the Indian Ocean constitute a monophyletic clade with a low average genetic distance (d < 0.5%). However both genetic markers indicated some structure within this ocean. The main structure revealed was the isolation of the Maldives from the WIO localities (a different group signature identified by clustering analysis, great values of differentiation). Both marker types reveal further significant structure within the WIO, mainly the isolation of the Mascarene Islands (significant AMOVA and isolation-by-distance patterns) and some patchy structure between the northernmost localities and within the Mozambique Channel. The WIO genetic structure of E. merra appeared congruent with main biogeographic boundaries and oceanographic currents.
Marine Ecology-an Evolutionary Perspective (0173-9565) (Wiley-blackwell), 2015-09 , Vol. 36 , N. 3 , P. 447-461

Droits : 2014 Blackwell Verlag GmbH
http://archimer.ifremer.fr/doc/00189/30046/28566.pdf
DOI:10.1111/maec.12153
http://archimer.ifremer.fr/doc/00189/30046/

Éditeur(s) : Aquaculture 67 : 260-261
Résumé : An infection caused by a Perkinsus -like parasite has been observed in Ruditapes decussatus from Portugal (Comps and Chagot, 1987). Following a pathological study carried out on clams affected by mortalities in the Algarve area, this parasite was found again, inducing a reaction process in the host. Histological examination reveals the parasite in the connective tissue of different organs. The adjoining tissues, particularly the epithelia, are not affected.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1987/acte-3109.pdf
http://archimer.ifremer.fr/doc/00000/3109/

Éditeur(s) : Elsevier
Résumé : During the Fanindien 2006 cruise of R/V 'Beautemps-Beaupre', high resolution multibeam bathymetry, sub-bottom profiling and sediment coring was carried out along the East African margin, offshore Tanzania and Mozambique (Indian Ocean). The newly acquired data reveal the presence of a giant deep-sea valley (the Tanzania channel) that is more than 10 km wide at 4000 m water depth, along the continental rise. The valley remains similar to 70 m deep and 7 km wide at 800 km from the Tanzania coast. Morphological comparison with worldwide submarine channels show that the Tanzania channel is one of the largest known submarine valleys. This discovery brings new light on development of submarine valleys that drain sediments originated from the East African Rift System (EARS) highlands (i.e. the Tanzania channel and its neighbor Zambezi channel located similar to 1000 km southward). Both of the systems have a morphology markedly different to the classical sinuous, V-shaped channels located at similar latitudes (e.g. the Zaire or Amazon channels). Their submarine drainage system consists of a downslope converging tributary canyons joining a central trunk channel in the continental rise. The presence of such giant deep-sea drainage systems is probably linked to a strong structural control on the sediment pathway, associated to a massive sediment transfer towards the Indian Ocean in relation with the tectonic activity of the East African Rift System (i.e. the uplift periods trough mid-Miocene and Plio-Pleistocene times) and its interplay with the East African equatorial climate changes. (C) 2008 Elsevier B.V. All rights reserved.
Marine Geology (0025-3227) (Elsevier), 2008-12 , Vol. 255 , N. 3-4 , P. 179-185

Droits : 2008 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2008/publication-6855.pdf
DOI:10.1016/j.margeo.2008.09.002

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The mangrove swamp environment constitutes a sulphide rich habitat harbouring some thioautotrophic organisms. The ciliate Zoothamnium niveum and the nematode Eubostrichus dianae, both known to live associated with bacterial sulphide-oxidizing ectosymbionts, were analysed as positive controls by Raman microspectrometry. The detection of the 3 Raman bands characteristic of elemental sulphur (S8) allows us to define a positive model of sulphide-oxidizing symbiotic invertebrates and by extrapolation, of thioautotrophic organisms. A fast screening using this tool was carried out on eukaryotic organisms such as hydrozoan, nematodes, annelids, copepods, and ciliate (Pseudovorticella sp.) and on free-living filamentous bacteria found on decomposing leaves in order to detect thioautotrophic organisms. The Raman microspectrometry permits us: (i) to reveal thioautotrophic metabolism of free-living bacteria (Beggiatoa sp.) and even for Archaea and (ii) to detect sulphide-oxidizing endosymbiotic and ectosymbiotic bacteria associated with the Bivalve Lucina pectinata and Pseudovorticella sp., respectively. Raman microspectrometry represents a fast, easy and non destructive technique which can be used on living organisms without constraints of sample size. The Raman analysis can also be completed by ultrastructural analysis (SEM, TEM) on the same sample.
ISSN: 0141-1136

hal-00715329
https://hal.univ-antilles.fr/hal-00715329
DOI : 10.1016/j.marenvres.2010.02.001

Éditeur(s) : HAL CCSD American Society of Hematology
Résumé : International audience
Polycythemia vera (PV) is characterized by an increased RBC mass, spontaneous erythroid colony formation, and the JAK2V617F mutation. PV is associated with a high risk of mesenteric and cerebral thrombosis. PV RBC adhesion to endothelial laminin is increased and mediated by phosphorylated erythroid Lu/BCAM. In the present work, we investigated the mechanism responsible for Lu/BCAM phosphorylation in the presence of JAK2V617F using HEL and BaF3 cell lines as well as RBCs from patients with PV. High levels of Rap1-GTP were found in HEL and BaF3 cells expressing JAK2V617F compared with BaF3 cells with wild-type JAK2. This finding was associated with increased Akt activity, Lu/BCAM phosphorylation, and cell adhesion to laminin that were inhibited by the dominant-negative Rap1S17N or by the specific Rap1 inhibitor GGTI-298. Surprisingly, knocking-down EpoR in HEL cells did not alter Akt activity or cell adhesion to laminin. Our findings reveal a novel EpoR-independent Rap1/Akt signaling pathway that is activated by JAK2V617F in circulating PV RBCs and responsible for Lu/BCAM activation. This new characteristic of JAK2V617F could play a critical role in initiating abnormal interactions among circulating and endothelial cells in patients with PV.
ISSN: 0006-4971

inserm-00821109
http://www.hal.inserm.fr/inserm-00821109
http://www.hal.inserm.fr/inserm-00821109/document
http://www.hal.inserm.fr/inserm-00821109/file/De_Grandis_Blood_2013.pdf
DOI : 10.1182/blood-2012-07-440487

Éditeur(s) : HAL CCSD Elsevier
Résumé : We use a triangular representation of the plunges of P, B, and Taxes to compare the different ways tectonic regime is inferred from earthquake focal mechanisms in recent works. We argue that P, B, and Taxes provide a reasonable estimate of principal stress directions when faulting is close to Andersonian conditions, and that this can be estimated from the location on a triangular diagram. We analyze the geometrical relationship between the plunges of P, B, and Taxes on one hand, and the rake of slip and dip of nodal planes on the other hand. We show that the rake and dip level curves correspond to trajectories of the vertical direction along great and small circles with respect to the frame of the P, B. and Taxes. This shows that dip-slip faulting is compatible with vertical P or Taxes, but does not require it, and instead requires horizontal B axes. It also shows that strike-slip faulting does not require vertical B axes, but P and Taxes with equal plunges. This also reveals that focal mechanisms where P, B, and Taxes all have moderate plunge correspond to two very different types of nodal planes: a steeply dipping one with oblique slip and a moderately dipping one with strike-slip. Seismically active and moderately dipping strike-slip faults are to be found among these events.
ISSN: 0040-1951

hal-00486367
https://hal.archives-ouvertes.fr/hal-00486367
DOI : 10.1016/j.tecto.2009.03.006

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
BACKGROUND: In Guadeloupe and Martinique, two French Overseas Departments, colorectal cancer (CRC) has become an essential public health issue. However, little is known about CRC characteristics and the p53 status in these populations, particularly in Guadeloupe, whereas certification of a cancer registry has been recently validated. METHODS: This was a descriptive retrospective study of 201 patients who, between 1995 and 2000, underwent surgery for CRC in the Guadeloupe Teaching Hospital (GlpeTH; 83 patients) and in the Martinique Teaching Hospital (MqueTH; 118 patients). The clinicopathological features and the p53 expression, evaluated with immunohistochemistry, were compared at the time of diagnosis. A relationship between these parameters and the p53 expression was also studied. Data were analysed, using the SPSS computer software version 17.0. RESULTS: No statistical difference was found between the two groups of patients regarding age (p = 0.60), percentage of young patients (<=50 years; p = 0.94)), sex (p = 0.47), histological type (p = 0.073) and tumour sites (p = 0.65), although the GlpeTH patients were diagnosed with more distal colon cancers (54.2%) than the Mque TH patients (47.4%). By contrast, a significant difference was found regarding the tumour grade (p < 0.0001), the pTNM stage (p = 0.045) and the pT stage (p < 0.0001). Regarding p53 expression, solely for the MqueTH patients, nuclear expression was associated with pTNM, the percentage of p53 negative tumours increasing with the progression of the pTNM stages (p = 0.029). CONCLUSIONS: For the first time, this study reveals discrepancies in clinicopathological features and in the p53 status between the two groups of patients. The GlpeTH patients were diagnosed with more moderated CRCs but with few CRCs at pTNM IV stage. By contrast, the MqueTH patients were diagnosed with more differentiated tumours, but with many more CRCs at pTNM IV stage. This paradox may be due to differences in tumour location (distal vs proximal), multiplicity of the genetic profiles of patients, or patients getting treatment elsewhere. Although our study is limited due to its small size, it emphasizes the originality of our results.
ISSN: 1472-6890

inserm-00971313
http://www.hal.inserm.fr/inserm-00971313
http://www.hal.inserm.fr/inserm-00971313/document
http://www.hal.inserm.fr/inserm-00971313/file/1472-6890-14-12.pdf
DOI : 10.1186/1472-6890-14-12