Quantification des flux sédimentaires et de la subsidence du bassin Provençal

The Gulf of Lions and the Provençal basin have been studied intensively at variable timescale. However, sedimentary budgets and vertical movements of the margin remained largely unknown. This work aims to quantify them using a large grid of seismic data and their interpretations with seismic and sequential stratigraphy concepts [Vail et al., 1977], correlations with existing drillings, refraction data and validation by numerical stratigraphic modeling with Dionisos [Granjeon and Joseph, 1999].A stratigraphic continuity of reflectors from the platform to the slope and to the deep basin has been established describing the architecture of the sedimentary filling of the entire margin. Plio-pleistocene stratigraphic markers (at 2.6 My, 1.6 My, 0.9 My and 0.45 My) have been correlated down to the foot of slope. The Messinian units underlined by previous studies [Bache, 2008] were also extended and/or detailed in specific areas. A new unit is described and interpreted as the residuals of the abrasion during the transgression which ended the famous messinian crisis. This allowed us to bring some new arguments for a new scenario of the event [Bache et al., 2012a](submitted). Drillings and refraction data led to 3D time-depths conversion laws for our chronostratigraphic units. We were therefore able to produce all the Plio-Pleistocene and Messinian maps in meters as well as the thickness maps of all units defined above the substratumuntil today (1 for the Miocene, 6 for the Messinian, 5 for the Plio-Pleistocene). The thicknesses and the sedimentary volumes were then quantified for every stratigraphic intervals. After decompaction, "true" volumes of deposits as well as sedimentary fluxes were therefore recalculated.Le Golfe du Lion et le Bassin Provençal sont l’objet de recherche intensive à toute échelle de temps et d’espace. Cependant, les budgets sédimentaires et les mouvements verticaux depuis la formation de la marge étaient restés inconnus ou sources de controverses. Ce travail se propose d’aborder leur quantification à partir de l’interprétation de nombreux profils sismiques, d’après les concepts de stratigraphie sismique et séquentielle [Vail et al., 1977], complétée par des données de forages et de sismique réfraction, et validée par des modélisations stratigraphiques avec Dionisos [Granjeon and Joseph, 1999]. L’établissement d’une continuité stratigraphique entre le domaine de plate-forme et le bassin profond offre une vision complète du remplissage sédimentaire de la marge. Les repères stratigraphiques du Plio-Pléistocène (2.6 Ma, 1.6 Ma, 0.9 Ma et 0.45 Ma) ont en effet été corrélés jusqu’au pied de pente. Les jalons messiniens, établis lors des travaux précédents [Bache, 2008] ont également été étendus et précisés localement. La mise en évidence d’une nouvelle unité, interprétée comme les résidus de l’abrasion lors de la transgression mettant fin à la célèbre crise, permet d’apporter des arguments pour l’établissement d’un nouveau scénario de l’évènement [Bache et al., 2012a](soumis). Des lois de conversion en profondeurs (métriques) des différentes unités chronostratigraphiques ont ensuite été établies en 3D à partir de l’ensemble des données de forage et de réfraction (ESP) et appliquées pour chacune de nos unités. Les profondeurs de l’ensemble des jalons plio-pléistocènes et messiniens ont ainsi pu être cartographiées, ainsi que les épaisseurs de chacune des unités définies depuis le substratum jusqu’à l’actuel (1 au Miocène, 6 au Messinien, 5 au Plio-Pléistocène). Les épaisseurs et volumes sédimentaires déposés ont alors pu être quantifiés sur chaque intervalle stratigraphique. Les séries sédimentaires ont été par la suite décompactées et les volumes "vrais" de dépôts et flux sédimentaires recalculés

Structure and evolution of the Gulf of Lions: The Sardinia seismic experiment and the GOLD (Gulf of Lions Drilling) project

International audienceThe study of the deep structure and evolution of passive continental margins is important for the understanding of rifting processes and the formation of associated sedimentary basins. Since the classical models of McKenzie (1978) and Wernicke (1985), understanding how passive continental margins form, that is to say mainly the way that continental lithosphere is thinned leading to subsidence, remains one of the main challenges in the Earth sciences. Many recent observations and discoveries have modified our basic views of margin formation. The conservational models paradigm (i.e., simple shear, pure shear, or polyphase models), which exclude exchanges between lower continental crust and upper mantle and which are usually proposed to explain lithospheric stretching and consequent crustal thinning of passive continental margins, fail to completely explain all these observations. Furthermore, these models imply a large amount of horizontal movement, movements not observed in the field. In consequence, new concepts need to be built and tested

The last glacial maximum Balearic Abyssal Plain megabed revisited

Megabeds are thick sedimentary layers extending over thousands square kilometres in deep sea basins and are thought to result from large slope failures triggered by major external events. Such deposits have been found in at least three areas of the Mediterranean Sea. Although their discovery dates back to the early 1980s, many questions remain, concerning their initiation, source area, extent, and the nature of their emplacement. One of the largest previously documented megabeds was emplaced during the Last Glacial Maximum across the Balearic Abyssal Plain with a thickness of 8-10 m in water depths of up to 2800 m. New 3.5 kHz sub-bottom profiles and sediment cores provide greater constraint on the lateral variability of the megabed and allow to map it beyond previous estimates, with a revised areal extent up to 90,000-100,000 km2. Megabed terminations show gradual pinch-out to the West and an abrupt eastward termination against the Sardinia steep margin. The megabed presents both in seismic profiles and in sediment cores a tripartite subdivision likely corresponding to changes in flow regimes across the basin with a central area of sandy facies and erosional base oriented NNE-SSW allowing renewed discussions about sources and trigger of the megabed

Detection of a Cis eQTL Controlling BMCO1 Gene Expression Leads to the Identification of a QTG for Chicken Breast Meat Color

Classical quantitative trait loci (QTL) analysis and gene expression QTL (eQTL) were combined to identify the causal gene (or QTG) underlying a highly significant QTL controlling the variation of breast meat color in a F2 cross between divergent high-growth (HG) and low-growth (LG) chicken lines. Within this meat quality QTL, BCMO1 (Accession number GenBank: AJ271386), encoding the β-carotene 15, 15′-monooxygenase, a key enzyme in the conversion of β-carotene into colorless retinal, was a good functional candidate. Analysis of the abundance of BCMO1 mRNA in breast muscle of the HG x LG F2 population allowed for the identification of a strong cis eQTL. Moreover, reevaluation of the color QTL taking BCMO1 mRNA levels as a covariate indicated that BCMO1 mRNA levels entirely explained the variations in meat color. Two fully-linked single nucleotide polymorphisms (SNP) located within the proximal promoter of BCMO1 gene were identified. Haplotype substitution resulted in a marked difference in BCMO1 promoter activity in vitro. The association study in the F2 population revealed a three-fold difference in BCMO1 expression leading to a difference of 1 standard deviation in yellow color between the homozygous birds at this haplotype. This difference in meat yellow color was fully consistent with the difference in carotenoid content (i.e. lutein and zeaxanthin) evidenced between the two alternative haplotypes. A significant association between the haplotype, the level of BCMO1 expression and the yellow color of the meat was also recovered in an unrelated commercial broiler population. The mutation could be of economic importance for poultry production by making possible a gene-assisted selection for color, a determining aspect of meat quality. Moreover, this natural genetic diversity constitutes a new model for the study of β-carotene metabolism which may act upon diverse biological processes as precursor of the vitamin A

Fifteen years of research on oral–facial–digital syndromes: from 1 to 16 causal genes

Oral–facial–digital syndromes (OFDS) gather rare genetic disorders characterised by facial, oral and digital abnormalities associated with a wide range of additional features (polycystic kidney disease, cerebral malformations and several others) to delineate a growing list of OFDS subtypes. The most frequent, OFD type I, is caused by a heterozygous mutation in the OFD1 gene encoding a centrosomal protein. The wide clinical heterogeneity of OFDS suggests the involvement of other ciliary genes. For 15 years, we have aimed to identify the molecular bases of OFDS. This effort has been greatly helped by the recent development of whole-exome sequencing (WES). Here, we present all our published and unpublished results for WES in 24 cases with OFDS. We identified causal variants in five new genes (C2CD3, TMEM107, INTU, KIAA0753 and IFT57) and related the clinical spectrum of four genes in other ciliopathies (C5orf42, TMEM138, TMEM231 and WDPCP) to OFDS. Mutations were also detected in two genes previously implicated in OFDS. Functional studies revealed the involvement of centriole elongation, transition zone and intraflagellar transport defects in OFDS, thus characterising three ciliary protein modules: the complex KIAA0753-FOPNL-OFD1, a regulator of centriole elongation; the Meckel-Gruber syndrome module, a major component of the transition zone; and the CPLANE complex necessary for IFT-A assembly. OFDS now appear to be a distinct subgroup of ciliopathies with wide heterogeneity, which makes the initial classification obsolete. A clinical classification restricted to the three frequent/well-delineated subtypes could be proposed, and for patients who do not fit one of these three main subtypes, a further classification could be based on the genotype

Étude comparative de deux dispositifs d’autotransfusion lors d’hémorragie massive d’origine cardiaque chez le miniporc Yucatan

L’autotransfusion représente une alternative à la transfusion homologue. Elle permet de réduire le recours au sang allogénique et ainsi la prévalence des réactions transfusionnelles qui lui sont associées. Les dispositifs d’autotransfusion actuellement utilisés en médecine humaine permettent la récupération et le traitement des globules rouges uniquement. Or, le dispositif développé par la société i-SEP, utilisant la filtration tangentielle, permet également de restituer au patient ses plaquettes, ce qui est intéressant lors de pertes d’importants volumes sanguins. Cette étude fait suite à plusieurs études précliniques réalisées aussi sur modèle porcin ainsi que sur sang humain. Elle a permis de démontrer que les objectifs de performance sont atteints pour le dispositif SAME™ en contexte d’hémorragie massive. Le rendement plaquettaire obtenu est également meilleur que celui obtenu par le dispositif XTRA® de SORIN, représentatif du marché. De plus, l’avantage de cette retransfusion de plaquettes est objectivable in vivo sur la numération plaquettaire des animaux. Il serait intéressant d’observer si cet avantage est cliniquement intéressant et durable lors du réveil des patients et si le suivi post-opératoire s’en trouve meilleur. De plus, il faudra se demander si ce type de dispositif et ainsi cette récupération plaquettaire doivent être utilisés dans toutes les situations cliniques ou uniquement lorsque cela est nécessaire, pour éviter notamment le recours à la transfusion prophylactique

Quantification of sediment fluxes and subsidence on the Gulf of lion margin

Le Golfe du Lion et le Bassin Provençal sont l’objet de recherche intensive à toute échelle de temps et d’espace. Cependant, les budgets sédimentaires et les mouvements verticaux depuis la formation de la marge étaient restés inconnus ou sources de controverses. Ce travail se propose d’aborder leur quantification à partir de l’interprétation de nombreux profils sismiques, d’après les concepts de stratigraphie sismique et séquentielle [Vail et al., 1977], complétée par des données de forages et de sismique réfraction, et validée par des modélisations stratigraphiques avec Dionisos [Granjeon and Joseph, 1999]. L’établissement d’une continuité stratigraphique entre le domaine de plate-forme et le bassin profond offre une vision complète du remplissage sédimentaire de la marge. Les repères stratigraphiques du Plio-Pléistocène (2.6 Ma, 1.6 Ma, 0.9 Ma et 0.45 Ma) ont en effet été corrélés jusqu’au pied de pente. Les jalons messiniens, établis lors des travaux précédents [Bache, 2008] ont également été étendus et précisés localement. La mise en évidence d’une nouvelle unité, interprétée comme les résidus de l’abrasion lors de la transgression mettant fin à la célèbre crise, permet d’apporter des arguments pour l’établissement d’un nouveau scénario de l’évènement [Bache et al., 2012a](soumis). Des lois de conversion en profondeurs (métriques) des différentes unités chronostratigraphiques ont ensuite été établies en 3D à partir de l’ensemble des données de forage et de réfraction (ESP) et appliquées pour chacune de nos unités. Les profondeurs de l’ensemble des jalons plio-pléistocènes et messiniens ont ainsi pu être cartographiées, ainsi que les épaisseurs de chacune des unités définies depuis le substratum jusqu’à l’actuel (1 au Miocène, 6 au Messinien, 5 au Plio-Pléistocène). Les épaisseurs et volumes sédimentaires déposés ont alors pu être quantifiés sur chaque intervalle stratigraphique. Les séries sédimentaires ont été par la suite décompactées et les volumes "vrais" de dépôts et flux sédimentaires recalculés.The Gulf of Lions and the Provençal basin have been studied intensively at variable timescale. However, sedimentary budgets and vertical movements of the margin remained largely unknown. This work aims to quantify them using a large grid of seismic data and their interpretations with seismic and sequential stratigraphy concepts [Vail et al., 1977], correlations with existing drillings, refraction data and validation by numerical stratigraphic modeling with Dionisos [Granjeon and Joseph, 1999].A stratigraphic continuity of reflectors from the platform to the slope and to the deep basin has been established describing the architecture of the sedimentary filling of the entire margin. Plio-pleistocene stratigraphic markers (at 2.6 My, 1.6 My, 0.9 My and 0.45 My) have been correlated down to the foot of slope. The Messinian units underlined by previous studies [Bache, 2008] were also extended and/or detailed in specific areas. A new unit is described and interpreted as the residuals of the abrasion during the transgression which ended the famous messinian crisis. This allowed us to bring some new arguments for a new scenario of the event [Bache et al., 2012a](submitted). Drillings and refraction data led to 3D time-depths conversion laws for our chronostratigraphic units. We were therefore able to produce all the Plio-Pleistocene and Messinian maps in meters as well as the thickness maps of all units defined above the substratumuntil today (1 for the Miocene, 6 for the Messinian, 5 for the Plio-Pleistocene). The thicknesses and the sedimentary volumes were then quantified for every stratigraphic intervals. After decompaction, "true" volumes of deposits as well as sedimentary fluxes were therefore recalculated

Archaeological tinned artefacts

International audienceUntil now, few research has been carried out on tinning of ferrous archaeological objects. Yet, number of archaeological evidences shows that this technic of iron treatment is performed since Iron Age. One of the main problem to study these artefacts is that the tin plating is very often hidden by products of corrosion, badly preserved and therefore, not always identified and taken in account during the process of restoration and thus, partly or totally destroye

Archaeological tinned artefacts

International audienceUntil now, few research has been carried out on tinning of ferrous archaeological objects. Yet, number of archaeological evidences shows that this technic of iron treatment is performed since Iron Age. One of the main problem to study these artefacts is that the tin plating is very often hidden by products of corrosion, badly preserved and therefore, not always identified and taken in account during the process of restoration and thus, partly or totally destroye

Action pattern of fusarium moniliforme endopolygalacturonase towards pectin fragments : comprehension and prediction

International audienceThe structures of complexes of Fusarium moniliforme endopolygalacturonase (endoPG) with non-methylated or partly methylated homogalacturonan fragments were modeled to identify the residues involved in substrate binding and to correlate the cleavage pattern with the experimental productive modes. The conformational space of the complex was extensively explored and malto- to hexo-oligogalacturonates were modeled in the active cleft. To select the most highly probable productive complex for each oligomer between DP2 and 6, four energetic criteria were defined. Noteworthingly, the results were in accordance with the experimental results showing the mode of action of this enzyme towards un-methyl-esterified oligogalacturonates. Furthermore, the amino-acid residues involved in the binding were confirmed by similar studies performed on other endoPGs. Then, the oligomers were gradually methyl-esterified at one or more positions and similar docking experiments were carried out. Markedly, the docking energies were not significantly modified by the methyl-esterification of the substrate and it is likely that the methyl-esterification of the substrate does not alter the mode of action of the enzyme. Finally, 1D sequence and 3D structure of the endopolygalacturonase of Aspergillus niger II, known to be strictly non-tolerant to methylesters, were compared with the sequence and structure of the tolerant F. moniliforme endopolygalacturonase to get to a structural comprehension of the tolerant-or not-behaviour of endoPGs with methyl-esterified pectins