Nouvelles données sur la séquence culturelle du site de Brassempouy (Landes) : Fouilles 1997-2002

National audienceThe field of Brassempouy is situated in the south of the Landes departement, two kilometres away from the village and forty kilometres south-east of Mont-de-Marsan in Chalosse. It holds several cavities (cave of the Pope, cave of the Hyenas, Dubalen gallery, Megaceros gallery) which belong to a complex karstic network, dug in a limestone formation of the Eocene, a few metres bellow the natural soil. The purpose of this article is to present the cultural sequence as it appears after the excavations 1997-2002.Le gisement de Brassempouy est localisé au sud du département des Landes (France), à deux kilomètres du village de Brassempouy et à quarante kilomètres au sud-ouest de Mont-de-Marsan, en Chalosse. Il comprend plusieurs cavités (grotte du Pape, grotte des Hyènes, galerie Dubalen, galerie du Mégacéros) qui appartiennent à un réseau karstique complexe creusé dans une formation calcaire de l'Eocène à quelques mètres sous le sol naturel. L'objectif de cet article est de présenter la séquence culturelle telle qu'elle apparaît à l'issue des fouilles 1997-2002

<i>Vibrio gallicus</i> sp. nov., isolated from the gut of the French abalone <i>Haliotis tuberculata</i>

Five alginolytic, facultatively anaerobic, non-motile bacteria were isolated from the gut of the abalone Haliotis tuberculata. Phylogenetic analyses based on 16S rDNA data indicated that these strains are related to Vibrio wodanis, Vibrio salmonicida, Vibrio logei and Vibrio fischeri (but with Vibrio gallicus sp. nov. (type strain, CIP 107863T=LMG 21878T=HT2-1T; DNA G+C content, 43·6–44·3 mol%) is proposed for this novel taxon. Several phenotypic features were disclosed that discriminated V. gallicus from other Vibrio species: V. gallicus can be differentiated from Vibrio halioticoli on the basis of four traits (β-galactosidase test and assimilation of three carbon compounds) and from Vibrio superstes by 16 traits

Les archives chorégraphiques entre mémoire et création

Les logiques d’usages des archives – entendons par là non seulement la finalité apparente de ces usages mais aussi le sens qu’y injecte l’usager – connaissent actuellement une diversification qui, par bien des aspects, paraît clore l’âge de l’usage exclusivement ou essentiellement historique qui s’était ouvert vers le milieu du XIXe siècle. De nouvelles formes de rapport aux documents d’archives s’instaurent, différentes de celles qui existent entre un historien et ses sources. Elles mettent en jeu d’autres registres, plus affectifs ou émotionnels, qui touchent à l’estime de soi, la construction des individus, les processus de subjectivation ou les mécanismes de production d’un roman familial. C’est dans ce contexte qu’il convient de situer l’archivage de la danse et les archives chorégraphiques, l’intensité des questionnements contemporains qu’ils suscitent, les spécificités, relatives sans doute, des réflexions qu’ils engendrent et l’existence de ce que l’on pourrait appeler une « archivistique artistique », c’est-à-dire un acte d’archivage intégré dans un processus de création artistique

Synovitis in osteoarthritis: current understanding with therapeutic implications

Modern concepts of osteoarthritis (OA) have been forever changed by modern imaging phenotypes demonstrating complex and multi-tissue pathologies involving cartilage, subchondral bone and (increasingly recognized) inflammation of the synovium. The synovium may show significant changes, even before visible cartilage degeneration has occurred, with infiltration of mononuclear cells, thickening of the synovial lining layer and production of inflammatory cytokines. The combination of sensitive imaging modalities and tissue examination has confirmed a high prevalence of synovial inflammation in all stages of OA, with a number of studies demonstrating that synovitis is related to pain, poor function and may even be an independent driver of radiographic OA onset and structural progression. Treating key aspects of synovial inflammation therefore holds great promise for analgesia and also for structure modification. This article will review current knowledge on the prevalence of synovitis in OA and its role in symptoms and structural progression, and explore lessons learnt from targeting synovitis therapeutically

Rhodolith Beds Are Major CaCO3 Bio-Factories in the Tropical South West Atlantic

Rhodoliths are nodules of non-geniculate coralline algae that occur in shallow waters (<150 m depth) subjected to episodic disturbance. Rhodolith beds stand with kelp beds, seagrass meadows, and coralline algal reefs as one of the world's four largest macrophyte-dominated benthic communities. Geographic distribution of rhodolith beds is discontinuous, with large concentrations off Japan, Australia and the Gulf of California, as well as in the Mediterranean, North Atlantic, eastern Caribbean and Brazil. Although there are major gaps in terms of seabed habitat mapping, the largest rhodolith beds are purported to occur off Brazil, where these communities are recorded across a wide latitudinal range (2°N - 27°S). To quantify their extent, we carried out an inter-reefal seabed habitat survey on the Abrolhos Shelf (16°50′ - 19°45′S) off eastern Brazil, and confirmed the most expansive and contiguous rhodolith bed in the world, covering about 20,900 km2. Distribution, extent, composition and structure of this bed were assessed with side scan sonar, remotely operated vehicles, and SCUBA. The mean rate of CaCO3 production was estimated from in situ growth assays at 1.07 kg m−2 yr−1, with a total production rate of 0.025 Gt yr−1, comparable to those of the world's largest biogenic CaCO3 deposits. These gigantic rhodolith beds, of areal extent equivalent to the Great Barrier Reef, Australia, are a critical, yet poorly understood component of the tropical South Atlantic Ocean. Based on the relatively high vulnerability of coralline algae to ocean acidification, these beds are likely to experience a profound restructuring in the coming decades

Simulation of the discharge propagation in a capillary tube in air at atmospheric pressure

International audienceThis paper presents simulations of an air plasma discharge at atmospheric pressure initiated by a needle anode set inside a dielectric capillary tube. We have studied the influence of the tube inner radius and its relative permittivity ε r on the discharge structure and dynamics. As a reference, we have used a relative permittivity ε r = 1 to study only the influence of the cylindrical constraint of the tube on the discharge. For a tube radius of 100 µm and ε r = 1, we have shown that the discharge fills the tube during its propagation and is rather homogeneous behind the discharge front. When the radius of the tube is in the range 300 to 600 µm, the discharge structure is tubular with peak values of electric field and electron density close to the dielectric surface. When the radius of the tube is larger than 700 µm, the tube has no influence on the discharge which propagates axially. For a tube radius of 100 µm, when ε r increases from 1 to 10, the discharge structure becomes tubular. We have noted that the velocity of propagation of the discharge in the tube increases when the front is more homogeneous and then, the discharge velocity increases with the decrease of the tube radius and ε r. Then, we have compared the relative influence of the value of tube radius and ε r on the discharge characteristics. Our simulations indicate that the geometrical constraint of the cylindrical tube has more influence than the value of ε r on the discharge structure and dynamics. Finally, we have studied the influence of photoemission processes on the discharge structure by varying the photoemission coefficient. As expected, we have shown that photoemission, as it increases the number of secondary electrons close to the dielectric surface, promotes the tubular structure of the discharge

The <i>Ectocarpus</i> genome and the independent evolution of multicellularity in brown algae

Brown algae (Phaeophyceae) are complex photosynthetic organisms with a very different evolutionary history to green plants, to which they are only distantly related1. These seaweeds are the dominant species in rocky coastal ecosystems and they exhibit many interesting adaptations to these, often harsh, environments. Brown algae are also one of only a small number of eukaryotic lineages that have evolved complex multicellularity (Fig. 1).We report the 214 million base pair (Mbp) genome sequence of the filamentous seaweed Ectocarpus siliculosus (Dillwyn) Lyngbye, a model organism for brown algae, closely related to the kelps (Fig. 1). Genome features such as the presence of an extended set of light-harvesting and pigment biosynthesis genes and new metabolic processes such as halide metabolism help explain the ability of this organism to cope with the highly variable tidal environment. The evolution of multicellularity in this lineage is correlated with the presence of a rich array of signal transduction genes. Of particular interest is the presence of a family of receptor kinases, as the independent evolution of related molecules has been linked with the emergence of multicellularity in both the animal and green plant lineages. The Ectocarpus genome sequence represents an important step towards developing this organism as a model species, providing the possibility to combine genomic and genetic2 approaches to explore these and other aspects of brown algal biology further

Integrins as therapeutic targets: lessons and opportunities.

The integrins are a large family of cell adhesion molecules that are essential for the regulation of cell growth and function. The identification of key roles for integrins in a diverse range of diseases, including cancer, infection, thrombosis and autoimmune disorders, has revealed their substantial potential as therapeutic targets. However, so far, pharmacological inhibitors for only three integrins have received marketing approval. This article discusses the structure and function of integrins, their roles in disease and the chequered history of the approved integrin antagonists. Recent advances in the understanding of integrin function, ligand interaction and signalling pathways suggest novel strategies for inhibiting integrin function that could help harness their full potential as therapeutic targets