Trapps d'Ethiopie à 30 Ma : Identification de retombées à grandes distances et leur impact climatique

Le volcanisme est l'un des principaux facteurs forçants du climat. Parmi, l'ensemble des éruptions volcaniques, les ti-apps se distinguent par leur ampleur exceptionnelle. Or, on s'est aperçu que leur mise en place coïncidait avec des crises bioclimatiques majeures. Cependant, le synchronisme entre événements est basé sur des corrélations stratigraphiques. Il n'a jamais été vérifié dans un même enregistrement, et est donc plus ou moins approximatif. Nous avons recherché les traces matérielles des retombées atmosphériques liées aux trapps d'Ethiopie dans des séries sédimentaires marines. L'identification de quatre tephras, nous a permis de rattacher directement les trapps aux Chrons C11r-C11n.1n de l'échelle biomagnétostrati graphique mondiale, de définir une aire de distribution et de quantifier les flux de matière exportée, d'étudier les modalités et la dynamique de transport du matériel volcanique, et enfin, d'évaluer le potentiel climatique associé à ces transferts.AIX-MARSEILLE3-BU Sc.St Jérô (130552102) / SudocSudocFranceF

PHENOTYPIC STUDY OF KIDNEY TRANSPLANT PATIENTS PRESENTING DE NOVO DSA: A FRENCH MULTICENTER COHORT OF 96 CASES

International audienc

The global stratotype section and point (GSSP) for the base of the Chattian Stage (paleogene system, oligocene series) at Monte Cagnero, Italy

The GSSP for the base of the Chattian Stage (Paleogene System, Oligocene Series) is defined at meter level 197 in the Monte Cagnero section, which belongs to the pelagic succession of the Umbria-Marche basin (Urbania, central Italy: 43°38′47.81″N-12°28′03.83″E). This level with an astronomical age of 27.82 Ma coincides with the highest common occurrence of the planktonic foraminifer Chiloguembelina cubensis at the base of planktonic foraminiferal O5 Zone and falls in the upper part of calcareous nannofossil NP24 Zone, in the lower part of dinocyst Dbi Zone, and in the lower Chron C9n. The proposal was approved by the International Subcommission of Paleogene Stratigraphy in July 2015, approved by the International Commission of Stratigraphy in August 2016, and ratified by the International Union of Geological Sciences in September 2016

The global stratotype section and point (GSSP) for the base of the Chattian Stage (paleogene system, oligocene series) at Monte Cagnero, Italy

The GSSP for the base of the Chattian Stage (Paleogene System, Oligocene Series) is defined at meter level 197 in the Monte Cagnero section, which belongs to the pelagic succession of the Umbria-Marche basin (Urbania, central Italy: 43°38′47.81″N-12°28′03.83″E). This level with an astronomical age of 27.82 Ma coincides with the highest common occurrence of the planktonic foraminifer Chiloguembelina cubensis at the base of planktonic foraminiferal O5 Zone and falls in the upper part of calcareous nannofossil NP24 Zone, in the lower part of dinocyst Dbi Zone, and in the lower Chron C9n. The proposal was approved by the International Subcommission of Paleogene Stratigraphy in July 2015, approved by the International Commission of Stratigraphy in August 2016, and ratified by the International Union of Geological Sciences in September 2016

Synthetic Rhamnolipid Bolaforms (SRBs) as inducers of plant innate immunity

Natural and synthetic elicitors have demonstrated a high potential for a more sustainable agriculture and the control of plant diseases via the induction of plant defense responses. Microbial biosurfactants like surfactin (Bacillus spp.) and rhamnolipids (Pseudomonas spp.) have recently been shown to stimulate the plant innate immune system. Unlike canonical elicitors exemplified by bacterial flagellin, some data suggest that surfactin and rhamnolipid perception do not depend on the presence of specific receptors in the plant cell but rather on the direct interaction of the molecules with the lipid phase of the plant plasma membrane. Moreover, surfactin and rhamnolipid interactions with plant cells are thought to depend on their amphipathicity and the length of their acyl chain. In an attempt to mimic the efficacy of these natural biosurfactants, we have synthesized via green chemistry new bio-inspired amphiphilic elicitors. In this work, we present the characterization of Arabidopsis innate immunity in response to synthetic rhamnolipid bolaforms (SRBs) with variable acyl chain lengths. Using an original pluridisciplinary approach that covers biophysical and biological assays, we assessed the capacity of SRBs to interact with plasma membranes and to stimulate defense responses in Arabidopsis thaliana. Our results show that SRBs, depending on the acyl chain length, differentially activated early and late immunityrelated signaling events, defense gene expression and cell death. Moreover, we have demonstrated that an unsaturated SRB containing a C14 acyl chain is effective to induce local resistance against the hemibiotrophic bacteria Pseudomonas syringae pv. tomato. The biophysical studies suggest that a direct interaction of the SRB C14 with the plasma membrane lipids would be involved in the plant perception and induction of plant immunity

Biomagnetostratigraphy of ODP Leg 189 sites

Late Cretaceous (Maastrichtian)-Quaternary summary biostratigraphies are presented for Ocean Drilling Program (ODP) Leg 189 Sites 1168 (West Tasmanian Margin), 1170 and 1171 (South Tasman Rise), and 1172 (East Tasman Plateau). The age models are calibrated to magnetostratigraphy and integrate both calcareous (planktonic foraminifers and nannofossils) and siliceous (diatoms and radiolarians) microfossil groups with organic walled microfossils (organic walled dinoflagellate cysts, or dinocysts). We also incorporate benthic oxygen isotope stratigraphies into the upper Quaternary parts of the age models for further control. The purpose of this paper is to provide a summary age-depth model for all deep-penetrating sites of Leg 189 incorporating updated shipboard biostratigraphic data with new information obtained during the 3 yr since the cruise. In this respect we provide a report of work to November 2003, not a final synthesis of the biomagnetostratigraphy of Leg 189, yet we present the most complete integrated age model for these sites at this time. Detailed information of the stratigraphy of individual fossil groups, paleomagnetism, and isotope data are presented elsewhere. Ongoing efforts aim toward further integration of age information for Leg 189 sites and will include an attempt to correlate zonation schemes for all the major microfossil groups and detailed correlation between all sites