"La Grande Vasière" mid-shelf mud belt : Holocene sedimentary structure, natural and anthropogenic impacts

The Quaternary sequence of the Armorican continental shelf in the Bay of Biscay is setting down above one regional erosion surface, which has been produced by successive transgressions that occurred during the last deglaciations. The few meters of the sequence covers the Holocene period and it is composed by two clean and sandy units at the base followed by thin (few decimetres) clayed sand unit and mud (few millimetres) unit in the top. The two upper units form the improperly called "La Grande Vasière" area over 8,000 km2. The settlement of these sedimentary units occurred since 8,000 C14 years BP, previously to other coastal mud fields setting of the shelf. Historical grain size data show that the mud field has lost part of the fine content during the last 30 years. "La Grande Vasière" evolves at the rhythm of the cycles of deposition and remobilization. Fluvial supplies and tide currents are the major control factors of the deposition. Bioturbation enhances the homogenization of the surficial sediments. Waves and anthropogenic actions are the main factors for the remobilization of the fine particles. The action of both the storms and the bottom trawls are tentatively quantified

Golfe Normano-Breton. Bilan des connaissances

Ce document a été élaboré dans le cadre de la préparation d'un programme d' "étude régionale intégrée" du golfe normano-breton. Réalisé dans des délais très courts, il ne constitue pas un inventaire exhaustif des travaux effectués dans le golfe mais une illustration par grands secteurs disciplinaires de l'état actuel des connaissances. Son objectif est de cerner les domaines à développer dans le cadre d'une programmation poly-disciplinaire orientée vers la gestion de l'espace littoral. La présentation par disciplines fondamentales de l'océanographie (physique, sédimentologie, biologie) est associée à un bilan de l'utilisation du milieu, faisant apparaître la diversité et la complexité des problèmes à résoudre. En effet, point privilégié entre la Manche Est, la Manche Ouest et le continent, le golfe est le siège d'une activité humaine intense et diversifiée : conchyliculture, pêche, extraction d'agrégats, rejets industriels (La Hague, et prochainement Flamanville), tourisme, activité portuaire ... Par ailleurs de nombreux projets d'aménagement sont à l'étude depuis ces dernières années : usine marémotrice, schéma d'aménagement conchylicole et aquacole, insularité du Mont St Michel, Parc National des Chausey .. . Ce dossier fait apparaître un certain nombre de voies scientifiques à developper dans des délais relativement brefs si l'on veut maitriser la connaissance des phénomènes naturels indispensables à une gestion globale de cette zone

The exon-junction-complex-component metastatic lymph node 51 functions in stress-granule assembly.

Metastatic lymph node 51 [MLN51 (also known as CASC3)] is a component of the exon junction complex (EJC), which is assembled on spliced mRNAs and plays important roles in post-splicing events. The four proteins of the EJC core, MLN51, MAGOH, Y14 and EIF4AIII shuttle between the cytoplasm and the nucleus. However, unlike the last three, MLN51 is mainly detected in the cytoplasm, suggesting that it plays an additional function in this compartment. In the present study, we show that MLN51 is recruited into cytoplasmic aggregates known as stress granules (SGs) together with the SG-resident proteins, fragile X mental retardation protein (FMRP), poly(A) binding protein (PABP) and poly(A)(+) RNA. MLN51 specifically associates with SGs via its C-terminal region, which is dispensable for its incorporation in the EJC. MLN51 does not promote SG formation but its silencing, or the overexpression of a mutant lacking its C-terminal region, alters SG assembly. Finally, in human breast carcinomas, MLN51 is sometimes present in cytoplasmic foci also positive for FMRP and PABP, suggesting that SGs formation occurs in malignant tumours