Résumé : In the French West Indies islands, the transfer of chlordecone (kepone) from treated grounds towards the marine environment has been proved since the beginning of 2000s. In 2008, a maximal residue limit (MRL) was set at 20 µg / kg wet weight in fish and seafood, and therefore intensified the concern about the risks of high human exposure to the pesticide due to the consumption of contaminated marine products. To answer this concern, several sampling cruises were carried by public authorities and by Ifremer in order to analyze the contamination of the fish fauna around the Guadeloupe island. The data collected within these surveys improved our knowledge on the characteristics of the contamination of fish fauna and allowed to assess the distribution of this contamination in relation with optional geographical plans of the marine area around the Guadeloupe island. Further, this study was completed by an assessment of the fishery activity in areas which are the more exposed to the chlordecone contamination, taking into account data from a fishery observatory which has been set up in the archipelago since 2007. The results allow to precise two main characteristics of distribution of the contamination: its spatial and specific dimensions. About the spatial aspect, contamination of the fish fauna is centred on marine areas which are closely downstream contaminated watersheds. Concerning the marine fauna, two species groups are particularly exposed: the very coastal ones, particularly those living at or close to the mouth of rivers, and crustaceans wherever they live. Among fishes, the most contaminated species belong to many various groups which are present in the very coastal belt, more or less regularly. Lastly, this study provided orders of magnitude on the relative part of the fishery activity around the archipelagos for which the contamination is of great concern.
Aux Antilles, l’existence d’un transfert de la molécule de chlordécone des sols traités vers le milieu marin est avérée depuis le début des années 2000. L’établissement d’une limite maximale de résidus à 20 µg/kg pf pour tous les produits marins en 2008 y a intensifié la préoccupation vis-à-vis des risques d’exposition des populations humaines par les produits de la pêche. Pour répondre à cette préoccupation, depuis 2008, plusieurs campagnes d’échantillonnage ont été réalisées par les services de l’Etat (DAAF) et par l’Ifremer pour analyser la contamination de la faune halieutique autour de la Guadeloupe. Les données collectées de 2008 à 2011 par ces plans d’observation ont été utilisées pour actualiser les connaissances sur les caractéristiques de la contamination de la faune halieutique autour de la Guadeloupe, et analyser cette distribution en référence à différents schémas de segmentation du domaine marin. L’étude a été complétée par une analyse de l’activité halieutique dans les secteurs les plus sensibles à la contamination, à partir des données du système d’informations halieutiques déployé dans l’archipel depuis 2007. L’analyse a permis de préciser deux traits majeurs de cette distribution : sa dimension spatiale et son caractère spécifique. Sur le plan spatial, la contamination de la faune halieutique est centrée sur les espaces maritimes situées immédiatement en aval des bassins versants contenant des sols contaminés. Sur le plan faunistique, deux groupes apparaissent particulièrement sensibles, les espèces très côtières, en particulier celles fréquentant les embouchures des cours d’eau, et les crustacés, quelque soit leur milieu de vie. Chez les poissons, parmi les espèces contaminées, on trouve un large cortège d’espèces fréquentant plus ou moins régulièrement la bande littorale. Enfin, l’étude a permis de fournir des ordres de grandeur sur la part de l’activité halieutique de l’archipel directement concernée par cette pollution.

Droits : 2013 Ifremer
http://archimer.ifremer.fr/doc/00136/24762/22840.pdf
http://archimer.ifremer.fr/doc/00136/24762/

Éditeur(s) : HAL CCSD Blackwell Publishing
Résumé : International audience
In the Causses platform (south-east France), Late Hettangian to Sinemurian deposits were interpreted previously as shallow-water carbonate ramp deposits. A new look at these deposits has shown a fault-controlled mosaic carbonate platform that is different from the carbonate ramp models. Within the platform mosaic, 15 lithofacies have been recognized, which are organized in four facies associations, including peritidal, restricted shallow sub-tidal, sand dunes and sub-tidal shelf facies associations. The rapid lateral and vertical facies changes, and the lack of consistent landward or seaward direction indicated by the pattern of facies changes, question the existence of a shoreline suggested by the traditional models for this region. Instead, the facies organization and cycle stacking pattern suggest deposition in a mosaic of intertidal islands between which sub-tidal restricted or open conditions could coexist in very close proximity. Such a platform mosaic would have been defined by tectonic activities along normal faults which segmented the shallow-water Causses platform. The facies and facies associations are arranged into metre-scale, peritidal and sub-tidal cycles that are also variable. Certain cycles show the same stacking pattern in all the sections and seem to be traceable over tens of kilometres. On the contrary, other cycles cannot be correlated; they are present only in specific sections and have a maximum lateral extension of 1 or 2 km. These metre-scale cycles stack to form four medium-scale cycles bounded by surfaces that display sub-aerial exposure features. Medium-scale cycles stack into two larger-scale cycles (tens of metres thick) and are bounded by well-defined karstic surfaces. Based on their lateral continuity and their stacking pattern, the metre-scale cycles are controlled probably by high frequency eustatic variations overprinting the topographic irregularities formed by differential subsidence of fault-bounded blocks. Episodic fault activities may reorganize the topography so that, even if eustatic changes may still be the major control of cycles, the expression and number of cycles could be different. Cycles of medium and large-scale are interpreted as being allogenic, controlled by changes in eustasy and/or subsidence rates as evidenced by their lateral continuity and the correlations of the large-scale cycles with third-order depositional sequences.
ISSN: 1469-3496

hal-00411940
https://hal.archives-ouvertes.fr/hal-00411940
DOI : 10.1111/j.1365-3091.2007.00896.x

Éditeur(s) : HAL CCSD American Society for Pharmacology and Experimental Therapeutics (ASPET)
Résumé : International audience
Most human hepatocyte cell lines lack a substantial set of liver-specific functions, especially major cytochrome P450 (P450)-related enzyme activities, making them unrepresentative of in vivo hepatocytes. We have used the HepaRG cells, derived from a human hepatocellular carcinoma, which exhibit a high differentiation pattern after 2 weeks at confluency to determine whether they could mimic human hepatocytes for drug metabolism and toxicity studies. We show that when passaged at low density, these cells reversed to an undifferentiated morphology, actively divided, and, after having reached confluency, formed typical hepatocyte-like colonies surrounded by biliary epithelial-like cells. By contrast, when seeded at high density, hepatocyte-like clusters retained their typical differentiated morphology. Transcripts of various nuclear receptors (aryl hydrocarbon receptor, pregnane X receptor, constitutive androstane receptor, peroxisome proliferator-activated receptor alpha), P450s (CYP1A2, 2C9, 2D6, 2E1, 3A4), phase 2 enzymes (UGT1A1, GSTA1, GSTA4, GSTM1), and other liver-specific functions were estimated by reverse transcriptase-quantitative polymerase chain reaction and were found to be expressed, for most of them, at comparable levels in both confluent differentiated and high-density differentiated HepaRG cells and in cultured primary human hepatocytes. For several transcripts, the levels were strongly increased in the presence of 2% dimethyl sulfoxide. Measurement of basal activities of several P450s and their response to prototypical inducers as well as analysis of metabolic profiles and cytotoxicity of several compounds confirmed the functional resemblance of HepaRG cells to primary cultured human hepatocytes. In conclusion, HepaRG cells constitute the first human hepatoma cell line expressing high levels of the major P450s involved in xenobiotic metabolism and represent a reliable surrogate to human hepatocytes for drug metabolism and toxicity studies.
ISSN: 0090-9556

hal-00702085
https://hal.archives-ouvertes.fr/hal-00702085
DOI : 10.1124/dmd.105.006759
PUBMED : 16204462

Éditeur(s) : Actes du colloque, April 28-30 1997
Résumé : Due to favourable environmental conditions and political will, marine fish farming has developed recently around the Mediterranean. The Mediterranean area is characterised by a large number of islands which are extremely diversified from geographical, political or socioeconomic point of views. As a matter of fact, it turns out that almost a third of the Mediterranean fish farming production comes from these islands which have proven to offer good conditions for the development of that new activity. The reasons why somany enterprises have been established on islands are very diverse. Taking advantage of good environmental conditions is the most common motivation, since islands are usually less submitted to constraints due to town extension, industry development or intensive agriculture. Moreover, as far as European Union countries are concerned, incentive policy towards ultraperipheral or late development regions has made it possible to attribute specific subsidies to islands for aquaculture in the aim of more employment and wealth. Like any other economic activity, aquaculture has to face some specific constraints due to the insular context. Transport to and from the islands is more expensive and less regular, which has a negative impact on the price competitiveness of the insular products. Local markets are often too small to make it possible for the enterprises to develop first at a domestic level and to take advantage of economies of scale. Thanks to their positive and attractive world-wide image, Mediterranean islands could promote the quality of their products on the basis of geographical origin, of quality of the environment or of specific production processes. Information networks implementation and marketing approach in terms of image are challenges Mediterranean islands have to take up in order to supply the large European seafood market with quality products. [NOT CONTROLLED OCR]
Grâce à de bonnes conditions de milieu et à une volonté politique affirmée, l'élevage des poissons marins s'est développé récemment dans la Méditerranée. Le bassin méditerranéen possède un très grand nombre d'îles qui sont très diverses de par leur caractéristiques géographiques, politiques ou socio-économiques. Près du tiers de la production de poissons marins d'élevage des pays méditerranéens est réalisée dans des îles. Les raisons qui ont incité tant d'entreprises à s'établir sur des îles sont diverses. La motivation principale avancée par les promoteurs de l'aquaculture insulaire méditerranéenne est la qualité de l'environnement des îles et la disponibilité en sites, justifiée par le fait que les îles sont moins soumises à certaines contraintes comme l'extension des villes, le développement de zones industrielles ou l'intensification de l'agriculture. La politique d'aide envers les régions ultra-périphériques ou en retard de développement a permis d'attribuer des subventions spécifiques aux îles pour développer l'aquaculture dans un objectif de création de richesse et d'emploi. Comme toute autre activité économique dans les îles, l'aquaculture doit faire face à des contraintes directement liées à l'insularité. Le transport est plus coûteux et moins régulier, ce qui a un effet négatif sur la compétitivité prix des produits. Les marchés locaux sont souvent trop petits pour permettre aux entreprises de se développer d'abord en interne et de profiter d'économies d'échelle. Une réponse possible à cette contrainte de concurrence internationale pourrait être la promotion des produits sur la base de l'origine géographique,de la qualité de l'environnement ou de procédés de production spécifiques afin de valoriser l'image très positive et la notoriété de ces îles dans le monde entier. Les réseaux dédiés à l'information, à la recherche et au transfert technologique sont des outils nécessaires pour compenser les contraintes dues à la petite taille et à l'isolement dans le but de fournir le vaste marché européen en produits de la mer de qualité. [OCR NON CONTRÔLE]

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1997/acte-4010.pdf
http://archimer.ifremer.fr/doc/00000/4010/

Résumé : Bycatch of marine turtles, vulnerable or endangered species, is a growing issue of all fisheries, including Oceanic purse-seine fishery. The present paper seeks to assess marine turtle bycatch at a spatial and temporal level in the European purse seine fishery operating in the Atlantic and Indian Oceans. The study was based on data collected through French and Spanish observer programs from 1995 to 2011, a period where more than 230 000 fishing sets were realized by the UE fleets in both Oceans. A total of 15 913 fishing sets were observed, including 6 515 on drifting Fish Aggregate Devices (FAD) and 9 398 on Free Swimming Schools (FSC). Over the study period, 597 turtles were caught, 86% being released alive at sea. At the same time, from 2003 to 2011, 14 124 specific observations were carried out on floating objects whether they ended in a set or not. 354 marine turtles were observed upon which 80% were already free or entangled alive and therefore released alive. At the temporal and spatial level, data were organized and analysed by Ocean, fishing mode (FAD vs. FSC) as well as by year, quarter and statistical square of 1°. In order to evaluate the impact if this fishery in both Oceans, bycatch distribution was compared to the total fishing effort of the UE fleet, as well as to the known marine turtle post nesting migration routes, nesting population abundances and known feeding areas. The species composition, the size and sex structure of bycatch are also discussed here. At last, an attempt to raise the data to the total fishing effort was carried out. Based on observation of marine turtle by-catches on sets, we estimated that, globally, 3500 marine turtles were accidentally captured by the EU-PS fleet in the Atlantic Ocean from 1995 to 2010, and around 2000 in the Indian Ocean from 2003 to 2010, with a corresponding annual bycatch rate of 218 (SD=150; survival rate =91%) and 250 (SD=157; survival rate =77%) respectively in the Atlantic and Indian Ocean. However, because of important uncertainties mainly due to the low observation coverage and the scarcity of marine turtle bycatch events, it was impossible to produce solid and reliable global estimates of marine turtle bycatch and mortality due to PS activity.

Droits : 2012 IOTC
http://archimer.ifremer.fr/doc/00149/25991/24087.pdf
http://archimer.ifremer.fr/doc/00149/25991/

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
Background: Myosin II (or Myosin Heavy Chain II, MHCII) is a family of molecular motors involved in the contractile activity of animal muscle cells but also in various other cellular processes in non-muscle cells. Previous phylogenetic analyses of bilaterian MHCII genes identified two main clades associated respectively with smooth/non-muscle cells (MHCIIa) and striated muscle cells (MHCIIb). Muscle cells are generally thought to have originated only once in ancient animal history, and decisive insights about their early evolution are expected to come from expression studies of Myosin II genes in the two non-bilaterian phyla that possess muscles, the Cnidaria and Ctenophora. Results: We have uncovered three MHCII paralogues in the ctenophore species Pleurobrachia pileus. Phylogenetic analyses indicate that the MHCIIa /MHCIIb duplication is more ancient than the divergence between extant metazoan lineages. The ctenophore MHCIIa gene (PpiMHCIIa) has an expression pattern akin to that of ``stem cell markers'' (Piwi, Vasa...) and is expressed in proliferating cells. We identified two MHCIIb genes that originated from a ctenophore-specific duplication. PpiMHCIIb1 represents the exclusively muscular form of myosin II in ctenophore, while PpiMHCIIb2 is expressed in non-muscle cells of various types. In parallel, our phalloidin staining and TEM observations highlight the structural complexity of ctenophore musculature and emphasize the experimental interest of the ctenophore tentacle root, in which myogenesis is spatially ordered and strikingly similar to striated muscle formation in vertebrates. Conclusion: MHCIIa expression in putative stem cells/proliferating cells probably represents an ancestral trait, while specific involvement of some MHCIIa genes in smooth muscle fibres is a uniquely derived feature of the vertebrates. That one ctenophore MHCIIb paralogue (PpiMHCIIb2) has retained MHCIIa-like expression features furthermore suggests that muscular expression of the other paralogue, PpiMHCIIb1, was the result of neofunctionalisation within the ctenophore lineage, making independent origin of ctenophore muscle cells a likely option.
ISSN: 1471-2148

hal-01544486
https://hal.archives-ouvertes.fr/hal-01544486
DOI : 10.1186/1471-2148-12-107

Éditeur(s) : HAL CCSD MDPI
Résumé : International audience
Drug transporters are now recognized as major actors in pharmacokinetics, involved notably in drug-drug interactions and drug adverse effects. Factors that govern their activity, localization and expression are therefore important to consider. In the present review, the implications of protein kinases C (PKCs) in transporter regulations are summarized and discussed. Both solute carrier (SLC) and ATP-binding cassette (ABC) drug transporters can be regulated by PKCs-related signaling pathways. PKCs thus target activity, membrane localization and/or expression level of major influx and efflux drug transporters, in various normal and pathological types of cells and tissues, often in a PKC isoform-specific manner. PKCs are notably implicated in membrane insertion of bile acid transporters in liver and, in this way, are thought to contribute to cholestatic or choleretic effects of endogenous compounds or drugs. The exact clinical relevance of PKCs-related regulation of drug transporters in terms of drug resistance, pharmacokinetics, drug-drug interactions and drug toxicity remains however to be precisely determined. This issue is likely important to consider in the context of the development of new drugs targeting PKCs-mediated signaling pathways, for treating notably cancers, diabetes or psychiatric disorders.
ISSN: 1422-0067

hal-01516024
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01516024
DOI : 10.3390/ijms18040764
PUBMED : 28375174

Résumé : The MEDECO Leg 2 cruise followed the MEDECO Leg 1 cruise that had crossed the Mediterranean Sea from the west to the east to study benthic communities of the Var canyon, deep corals found on the Calabrian Margin and cold seep ecosystems of the Mediterranean Ridge. The main objective of the MEDECO Leg 2 cruise was to study and compare, using a multidisciplinary approach, the structure and dynamics of deep-sea ecosystems at various active cold seep sites from the Nile deep sea fan and the Calabrian Arc, in the Eastern Mediterranean sea. During MEDECO Legs 1 & 2, a multiscale strategy was promoted to integrate (1) a high resolution cartography of geological structures (km2 scale), (2) a detailed mapping, including video imagery, of smaller-scale areas (scale 100 to 300 m2), (3) the physical, chemical and sedimentary characteristics of the habitat (multiscale), (4) the structure and functioning of faunal communities, including microbes, in terms of composition, diversity and biomass (multiscale), (5) small scale studies of interactions between organisms and their environment (scale < m2), (6) detailed ecophysiological studies at the organism scale on invertebrates. The use of the ROV “Victor 6000” and of various equipments for in situ and ex situ observations and measurements has helped reaching our objectives. The MEDECO cruise represented the key-Mediterranean cruise of the HERMES project “Hotspot Ecosystem Research on the Margins of European Seas” (P.I. P. Weaver, NOC-Southampton). The cruise was organized to follow the objectives of the HERMES program to better understand the functioning of deep ecosystems of the continental margins aiming at obtaining: (1) the description and quantification of the natural drivers (geological, hydrological, chemical factors) that control the distribution of ecosystems on margins; (2) the characterization and quantification of biodiversity, from bacteria to megafauna, as well as the knowledge of ecosystem functioning; (3) the study of ecosystems dynamics including the biology/physiology of key-species. Specific objectives. Colonization experiments conducted in the frame of two European programs, Diwoo and Chemeco, have given the opportunity to recover the fauna installed in the devices deployed during the Bionil cruise (2006) and to deploy new ones at the same site located in the pockmark area of the central province of Nile deep sea fan.

Droits : 2008 Insu, Cnrs, Locean
http://archimer.ifremer.fr/doc/00134/24550/22583.pdf
http://archimer.ifremer.fr/doc/00134/24550/

Éditeur(s) : HAL CCSD Impact journals
Résumé : International audience
TNF-Related Apoptosis-Inducing Ligand (TRAIL) is a well-known apoptosis inducer, which activates the extrinsic death pathway. TRAIL is pro-apoptotic on colon cancer cells, while not cytotoxic towards normal healthy cells. However, its clinical use is limited by cell resistance to cell death which occurs in approximately 50% of cancer cells. Short Chain Fatty Acids (SCFA) are also known to specifically induce apoptosis of cancer cells. In accordance, we have shown that food grade dairy propionibacteria induce intrinsic apoptosis of colon cancer cells, via the production and release of SCFA (propionate and acetate) acting on mitochondria. Here, we investigated possible synergistic effect between Propionibacterium freudenreichii and TRAIL. Indeed, we hypothesized that acting on both extrinsic and intrinsic death pathways may exert a synergistic pro-apoptotic effect. Whole transcriptomic analysis demonstrated that propionibacterial supernatant or propionibacterial metabolites (propionate and acetate), in combination with TRAIL, increased pro-apoptotic gene expression (TRAIL-R2/DR5) and decreased anti-apoptotic gene expression (FLIP, XIAP) in HT29 human colon cancer cells. The revealed synergistic pro-apoptotic effect, depending on both death receptors (TRAIL-R1/DR4, TRAIL-R2/DR5) and caspases (caspase-8, -9 and -3) activation, was lethal on cancer cells but not on normal human intestinal epithelial cells (HIEC), and was inhibited by Bcl-2 expression. Finally, milk fermented by P. freudenreichii induced HT29 cells apoptosis and enhanced TRAIL cytotoxic activity, as did P. freudenreichii DMEM culture supernatants or its SCFA metabolites. These results open new perspectives for food grade P. freudenreichii-containing products in order to potentiate TRAIL-based cancer therapy in colorectal cancer
ISSN: 1949-2553

hal-01259215
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01259215
DOI : 10.18632/oncotarget.6881
PUBMED : 26771233

Éditeur(s) : HAL CCSD
Résumé : 38 pages
Rapport
The Chicxulub impact crater, México, is unique. It is the only known terrestrial impact structure that has been directly linked to a mass extinction event and the only terrestrial impact with a global ejecta layer. Of the three largest impact structures on Earth, Chicxulub is the best preserved. Chicxulub is also the only known terrestrial impact structure with an intact, unequivocal topographic peak ring. Chicxulub’s role in the Cretaceous/Paleogene (K-Pg) mass extinction and its exceptional state of preservation make it an important natural laboratory for the study of both large impact crater formation on Earth and other planets and the effects of large impacts on the Earth’s environment and ecology. Our understanding of the impact process is far from complete, and despite more than 30 years of intense debate, we are still striving to answer the question as to why this impact was so catastrophic.During International Ocean Discovery Program (IODP) Expedition 364, Paleogene sediments and lithologies that make up the Chicxulub peak ring were cored to investigate (1) the nature and formational mechanism of peak rings, (2) how rocks are weakened during large impacts, (3) the nature and extent of post-impact hydrothermal circulation, (4) the deep biosphere and habitability of the peak ring, and (5) the recovery of life in a sterile zone. Other key targets included sampling the transition through a rare midlatitude section that might include Eocene and Paleocene hyperthermals and/or the Paleocene/Eocene Thermal Maximum (PETM); the composition and character of the impact breccias, melt rocks, and peak-ring rocks; the sedimentology and stratigraphy of the Paleocene–Eocene Chicxulub impact basin infill; the chronology of the peak-ring rocks; and any observations from the core that may help us constrain the volume of dust and climatically active gases released into the stratosphere by this impact. Petrophysical property measurements on the core and wireline logs acquired during Expedition 364 will be used to calibrate geophysical models, including seismic reflection and potential field data, and the integration of all the data will calibrate impact crater models for crater formation and environmental effects. The proposed drilling directly contributes to IODP Science Plan goals:Climate and Ocean Change: How resilient is the ocean to chemical perturbations? The Chicxulub impact represents an external forcing event that caused a 75% level mass extinction. The impact basin may also record key hyperthermals within the Paleogene.Biosphere Frontiers: What are the origin, composition, and global significance of subseafloor communities? What are the limits of life in the subseafloor? How sensitive are ecosystems and biodiversity to environmental change? Impact craters can create habitats for subsurface life, and Chicxulub may provide information on potential habitats for life, including extremophiles, on the early Earth and other planetary bodies. Paleontological and geochemical studies at ground zero will document how large impacts affect ecosystems and effects on biodiversity.Earth Connections/Earth in Motion: What are the composition, structure and dynamics of Earth’s upper mantle? What mechanisms control the occurrence of destructive earthquakes, landslides, and tsunami? Mantle uplift in response to impacts provides insight into dynamics that differ between Earth and other rocky planets. Impacts generate earthquakes, landslides, and tsunami, and scales that generally exceed plate tectonic processes yield insight into effects, the geologic record, and potential hazards.IODP Expedition 364 was a Mission Specific Platform expedition to obtain subseabed samples and downhole logging measurements from the sedimentary cover sequence and peak ring of the Chicxulub impact crater. A single borehole was drilled into the Chicxulub impact crater on the Yucatán continental shelf, recovering core from 505.7 to 1334.73 m below seafloor with ~99% core recovery and acquiring downhole logs for the entire depth.
International Ocean Discovery Program

hal-01639520
https://hal.archives-ouvertes.fr/hal-01639520
DOI : 10.14379/iodp.pr.364.2017

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Lung cancer is a serious public health problem. Although there has been significant progress in chemotherapy, non-small cell lung cancer is still resistant to current treatments, primarily because of the slow rate of cell development. It is thus important to find new molecules directed against targets other than proliferation agents. Considering the high proportion of mutant proteins in tumor cells, and the high rate of mutation of the TP53 gene in all cancers, and in NSCLC in particular, this gene is a perfect target. Certain new molecules have been shown to restore the activity of mutated p53 protein, for example PRIMA-1, which reactivates the His273 mutant p53. In a previous study, we presented triazine A190, a molecule with a cytostatic activity that blocks cells in the G1 phase and induces apoptosis. Here, we show that A190 not only restores mutant p53 activity, but also induces an overexpression of the NEDD9 gene, leading to apoptotic death. These findings might offer hope for the development of new targeted therapies, specific to tumor cells, which spare healthy cells
ISSN: 2045-2322

hal-01165439
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01165439
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01165439/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01165439/file/TP53%20transcription%20factor.pdf
DOI : 10.1038/srep10356

Éditeur(s) : HAL CCSD
Résumé : International audience
The development of diabetic vascular complications is initiated, at least in part, by mitochondrial reactive oxygen species (ROS) production in endothelial cells. Hyperglycemia induces superoxide production in the mitochondria and initiates changes in the mitochondrial membrane potential that leads to mitochondrial dysfunction. Hydrogen sulfide (H2S) supplementation has been shown to reduce the mitochondrial oxidant production and shows efficacy against diabetic vascular damage in vivo. However, the half-life of H2S is very short and it is not specific for the mitochondria. We have therefore evaluated two novel mitochondria-targeted anethole dithiolethione and hydroxythiobenzamide H2S donors (AP39 and AP123 respectively) at preventing hyperglycemia-induced oxidative stress and metabolic changes in microvascular endothelial cells in vitro. Hyperglycemia (HG) induced significant increase in the activity of the citric acid cycle and led to elevated mitochondrial membrane potential. Mitochondrial oxidant production was increased and the mitochondrial electron transport decreased in hyperglycemic cells. AP39 and AP123 (30–300 nM) decreased HG-induced hyperpolarisation of the mitochondrial membrane and inhibited the mitochondrial oxidant production. Both H2S donors (30–300 nM) increased the electron transport at respiratory complex III and improved the cellular metabolism. Targeting H2S to mitochondria retained the cytoprotective effect of H2S against glucose-induced damage in endothelial cells suggesting that the molecular target of H2S action is within the mitochondria. Mitochondrial targeting of H2S also induced >1000-fold increase in the potency of H2S against hyperglycemia-induced injury. The high potency and long-lasting effect elicited by these H2S donors strongly suggests that these compounds could be useful against diabetic vascular complications. © 2016
Pharmacological Research

hal-01373947
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01373947
DOI : 10.1016/j.phrs.2016.08.019
PUBMED : 27565382

Éditeur(s) : HAL CCSD
Résumé : International audience
The complexity of the Lesser Antilles vegetation must be linked to the variety of topographic features that influence the structure of some climatic parameters, particularly the rainfall. The above mentioned environmental factors influence a plurality of biotopes colonized by specific phytocenoses. Using survey transects of different minimal areas, we highlighted the specific, biocenotic, structural and architectural heterogeneity of the survey stations. This spatio-temporal differentiation of plant groupings is strongly guided by the activities of the successive human societies. These elements show that the anthropized vegetation of the Lesser Antilles represents a true laboratory for the study of plant succession using the synchronic approach.
ISSN: 2320-5407

hal-01376445
https://hal.univ-antilles.fr/hal-01376445
DOI : 10.21474/IJAR01/1322

Éditeur(s) : HAL CCSD
Résumé : International audience
Abstract : Since 2011, the organization of linguistic education for foreigners has changed in France. Now, the FLI concept controls the integration of foreigners in the french society by a transmission of french language and republican values. Our paper is about the questions coming from the West Indies context, specifically in Guadeloupe, and it is looking at the educational matters closed to Haitians natives' people. We are asking questions about the code switching phenomena and are trying to find, out of the blue, how some contextual specific experiments can help the students in being proud of their culture and in changing their vision of scholar and learning system. Feedback from those oral original sessions are aimed at offering solutions to establish a suitable teaching method named FLR.
Depuis 2011, la loi française a renforcé sa politique linguistique en faveur d'une intégration des migrants, mettant en place l'enseignement du français langue d'intégration (FLI). Notre contribution considère dans ce cadre épistémologique les particularités sociolinguistiques et migratoires du territoire de la Guadeloupe et s'intéresse à une didactique contextualisée, notamment en ce qui concerne le public des migrants venus d'Haïti. Les effets de contexte sont interrogés à travers une analyse du dispositif de formation, des postures des formateurs, des écarts observés entre objectifs attendus et réalisés et de l'influence des représentations des apprenants. Nous interrogeons le rôle du contact entre les langues créoles et le français dans les apprentissages. Cette note propose également un projet de remédiation pédagogique adapté aux difficultés relevées et pose les bases d'une approche didactique idoine caractérisée par un travail centré sur la réassurance affective et culturelle.Mots clés : Insécurité linguistique, diglossie, créole haïtien, confiance en soi, langue vernaculaire, langue véhiculaire, outils pédagogiques, didactique contextualisée, didactique sociolinguistique, andragogie, remédiation pédagogique, réassurance.
Troubles du langage, Langue d'enseignement et rendement scolaire. Essai de diagnostic du système éducatif haïtien dans le département de l'Artibonite, Ouvrage collectif (Coordination : Rochambeau LAINY), 2016, L'Harmattan, Paris , 320 pages.

hal-01673268
https://hal.univ-antilles.fr/hal-01673268
https://hal.univ-antilles.fr/hal-01673268/document
https://hal.univ-antilles.fr/hal-01673268/file/FINAL%20ARTICLE%20Fr%C3%A9d%C3%A9ric%20Beaubrun%20communication%20-%20Colloque%20%20Ha%C3%AFti%20pathologies%20du%20langage%20et%20rendement%20scolaire.pdf

Éditeur(s) : Public Library Science
Résumé : Changes in phenology, the timing of seasonal activities, are among the most frequently observed responses to environmental disturbances and in marine species are known to occur in response to climate changes that directly affects ocean temperature, biogeochemical composition and sea level. We examined nesting seasonality data from long-term studies at 8 green turtle (Chelonia mydas) rookeries that include 21 specific nesting sites in the South-West Indian Ocean (SWIO). We demonstrated that temperature drives patterns of nesting seasonality at the regional scale. We found a significant correlation between mean annual Sea Surface Temperature (SST) and dates of peak nesting with rookeries exposed to higher SST having a delayed nesting peak. This supports the hypothesis that temperature is the main factor determining peak nesting dates. We also demonstrated a spatial synchrony in nesting activity amongst multiple rookeries in the northern part of the SWIO (Aldabra, Glorieuses, Mohéli, Mayotte) but not with the eastern and southern rookeries (Europa, Tromelin), differences which could be attributed to females with sharply different adult foraging conditions. However, we did not detect a temporal trend in the nesting peak date over the study period or an inter-annual relation between nesting peak date and SST. The findings of our study provide a better understanding of the processes that drive marine species phenology. The findings will also help to predict their ability to cope with climate change and other environmental perturbations. Despite demonstrating this spatial shift in nesting phenology, no trend in the alteration of nesting dates over more than 20 years was found.
Plos One (1932-6203) (Public Library Science), 2012-10 , Vol. 7 , N. 10 , P. 1-13

Droits : 2012 Dalleau et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
http://archimer.ifremer.fr/doc/00098/20940/18558.pdf
DOI:10.1371/journal.pone.0046920
http://archimer.ifremer.fr/doc/00098/20940/

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
1. The Before-After Control-Impact Paired Series (BACIPS) design distinguishes natural spatial and temporalvariability from variation induced by an environmental impact (or intervention) of interest. BACIPS is a powerfultool to derive inferences about interventions when classic experimental approaches (e.g. which rely on spatialreplicates and random assignment of treatments) are not feasible or desirable. Previously applied BACIPSdesigns generally assume that effects are sudden, constant and long-lived: that is, that systems exhibit ‘stepchanges’in response to interventions. However, complex ecological interactions or gradual interventions maycreate delayed and/or progressive responses, potentially impeding the reliability of classic (step-change) analyses.2. We propose a novel approach, the Progressive-Change BACIPS, which generalizes and expands the scope ofBACIPS analyses.We evaluate the relative performance of this approach using both simulated and real data thatexhibit step-change, linear, asymptotic and sigmoid responses following an intervention.We quantify the statisticalpower and accuracy of the Progressive-Change BACIPS under varying initial population densities, intensityof spatial sampling, effect sizes and number of sampling dates After the intervention.3. We show that Progressive-Change BACIPS identified the correct model among the set of candidate modelsunder most conditions and led to accurate estimates of the parameters that were used to generate the simulateddata. When data were sparse, and the dynamics complex, simpler (more parsimonious) models were favouredover the more complex models that actually generated the simulated data. Application of the Progressive-Change BACIPS to existing data sets from the literature led to strong support for specific models (over alternatives)and led to more specific inferences than possible under the classic BACIPS approach.4. The Progressive-Change BACIPS proposed here is more flexible than the original BACIPS formulationbecause the data are used to inform the form of the final model, rather than having the form of the modelimposed on the data. This leads to better estimates of the effects of environmental impacts and the time-scalesover which they operate. As a result, the Progressive-Change BACIPS should be applicable to a wide range ofstudies and should help improve investigation of time-dependent effects. R code to perform Progressive-ChangeBACIPS analysis is provided.
ISSN: 2041-210X

hal-01416668
https://hal-univ-perp.archives-ouvertes.fr/hal-01416668
DOI : 10.1111/2041-210X.12655

Éditeur(s) : HAL CCSD BioMed Central
Résumé : [b]Background[/b]: [i]Amblyomma variegatum[/i] and [i]A. hebraeum[/i] are two ticks of veterinary and human health importance in south-east Africa. In Zimbabwe they occupy parapatric (marginally overlapping and juxtaposed) distributions. Understanding the mechanisms behind this parapatry is essential for predicting the spatio-temporal dynamics of Amblyomma spp. and the impacts of associated diseases. It has been hypothesized that exclusive competition between these species results from competition at the levels of male signal reception (attraction-aggregation-attachment pheromones) or sexual competition for mates. This hypothesis predicts that the parapatry described in Zimbabwe could also be present in other countries in the region. [br/][b]Methods[/b]: To explore this competitive exclusion hypothesis we conducted field surveys at the two species' range limits in Mozambique to identify areas of sympatry (overlapping areas) and to study potential interactions (communicative and reproductive interference effects) in those areas. At sympatric sites, hetero-specific mating pairs were collected and inter-specific attractiveness/repellent effects acting at long and short distances were assessed by analyzing species co-occurrences on co-infested herds and co-infested hosts.[br/] [b]Results[/b]: Co-occurrences of both species at sampling sites were infrequent and localized in areas where both tick and host densities were low. At sympatric sites, high percentages of individuals of both species shared attachment sites on hosts and inter-specific mating rates were high. Although cross-mating rates were not significantly different for[i] A. variegatum[/i] and [i]A. hebraeum[/i] females, attraction towards hetero-specific males was greater for [i]A. hebraeum[/i] females than for A. variegatum females and we observed small asymmetrical repellent effects between males at attachment sites.[br/][b]Conclusions[/b]: Our observations suggest near-symmetrical reproductive interference between [i]A. variegatum[/i] and [i]A. hebraeum[/i], despite between-species differences in the strength of reproductive isolation barriers acting at the aggregation, fixation and partner contact levels. Theoretical models predict that sexual competition coupled with hybrid inviability, greatly reduces the probability of one species becoming established in an otherwise suitable location when the other species is already established. This mechanism can explain why the parapatric boundary in Mozambique has formed within an area of low tick densities and relatively infrequent host-mediated dispersal events.
ISSN: 1756-3305

hal-01220744
https://hal.archives-ouvertes.fr/hal-01220744
https://hal.archives-ouvertes.fr/hal-01220744/document
https://hal.archives-ouvertes.fr/hal-01220744/file/2015%20Bournez%20Parasites%20%26%20Vectors_%7B365AAFF5-7041-480B-9B77-9CD0485A9B72%7D.pdf
DOI : 10.1186/s13071-015-1116-7

Éditeur(s) : HAL CCSD Impact journals
Résumé : International audience
TNF-Related Apoptosis-Inducing Ligand (TRAIL) is a well-known apoptosis inducer, which activates the extrinsic death pathway. TRAIL is pro-apoptotic on colon cancer cells, while not cytotoxic towards normal healthy cells. However, its clinical use is limited by cell resistance to cell death which occurs in approximately 50% of cancer cells. Short Chain Fatty Acids (SCFA) are also known to specifically induce apoptosis of cancer cells. In accordance, we have shown that food grade dairy propionibacteria induce intrinsic apoptosis of colon cancer cells, via the production and release of SCFA (propionate and acetate) acting on mitochondria. Here, we investigated possible synergistic effect between Propionibacterium freudenreichii and TRAIL. Indeed, we hypothesized that acting on both extrinsic and intrinsic death pathways may exert a synergistic pro-apoptotic effect. Whole transcriptomic analysis demonstrated that propionibacterial supernatant or propionibacterial metabolites (propionate and acetate), in combination with TRAIL, increased pro-apoptotic gene expression (TRAIL-R2/DR5) and decreased anti-apoptotic gene expression (FLIP, XIAP) in HT29 human colon cancer cells. The revealed synergistic pro-apoptotic effect, depending on both death receptors (TRAIL-R1/DR4, TRAIL-R2/DR5) and caspases (caspase-8,-9 and-3) activation, was lethal on cancer cells but not on normal human intestinal epithelial cells (HIEC), and was inhibited by Bcl-2 expression. Finally, milk fermented by P. freudenreichii induced HT29 cells apoptosis and enhanced TRAIL cytotoxic activity, as did P. freudenreichii DMEM culture supernatants or its SCFA metabolites. These results open new perspectives for food grade P. freudenreichii-containing products in order to potentiate TRAIL-based cancer therapy in colorectal cancer.
ISSN: 1949-2553

hal-01404971
https://hal.inria.fr/hal-01404971
https://hal.inria.fr/hal-01404971/document
https://hal.inria.fr/hal-01404971/file/2016%20Oncotarget_The%20probiotic%20Propionibacterium%20freudenreichii%20as%20a%20new%20adjuvant%20for%20TRAIL-based%20therapy%20in%20colorectal%20cancer..pdf
DOI : 10.18632/oncotarget.6881

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
The island of Taiwan is affected by intense seismic activity, which includes large events as the disastrous 1999 Chi-Chi earthquake. To improve seismic hazard assessment in this area, we estimate the effect of both interseismic loading and major events since 1736 on the state of stress of major active faults. We focus our approach on western Taiwan, which is the most densely populated part of Taiwan. We pay a specific attention to faults geometry and to both interseismic and coseismic slip distributions. Our results suggest that both earthquakes and interseismic loading before 1999 increase the Coulomb stress in the north-western part of the Chelungpu fault, a region which experienced the highest coseismic slip during the Chi-Chi earthquake. More importantly our results reveal a Coulomb stress increase in the southern part of the Changhua thrust fault, below a densely populated area.
ISSN: 0094-8276

hal-00475590
https://hal.archives-ouvertes.fr/hal-00475590
DOI : 10.1029/2009GL042292

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