Avant-propos au volume La notion de « chaîne opératoire » dans le monde : 50 ans d'études technologiques en Préhistoire

En 1964 s'est tenu aux Eyzies un symposium franco-américain auquel participèrent notamment Fr. Bordes, D. E. Crabtree et J. Tixier, décrit ensuite comme « une pierre de fondation de l’approche technologique » par C. Perlès en 1991. Un quart de siècle plus tard, faisant écho à cette rencontre, sont publiés les actes du colloque d'Antibes « 25 ans d’études technologiques en Préhistoire. Bilan et perspectives », confirmant la maturité de cette nouvelle démarche. Développée par l'école française (cf. les travaux de P. Bodu, M.-L. Inizan, J. Pelegrin, C. Perlès, N. Pigeot, J. Tixier et B. Valentin entre autres), il s'agit d'une approche qui met en œuvre diverses notions, dont celle de chaîne opératoire (initialement introduite par M. Mauss et A. Leroi-Gourhan), de remontage mental, d'économie des matières premières et d'économie du débitage. Cette démarche analytique et systémique vise à isoler les variations ayant peu ou pas de valeur techno-culturelle telles que les accidents de taille, les pièces déviantes, le rôle du support, l'état technique de la pièce ou l'influence de la matière première. Un demi-siècle plus tard, où en est cette approche ? Le présent volume, en illustrant la pérennité de cette école de pensée, se veut un début de réponse. Au sein de ce numéro sont ainsi rassemblés divers cas d’étude où cette méthodologie est appliquée à différentes productions (sur galet, sur éclat, bifaciales, laminaires et lamellaires) provenant d’Europe, du Proche-Orient, d’Asie, d’Océanie et d'Amérique. En présentant les recherches d’auteurs issus d’équipes et de pays variés, l'ensemble met en évidence comment cette démarche a su s’intégrer aux problématiques de diverses équipes en France et à l’international

Friction and Wear Studies Using Taguchi Method: Application to the Characterization of Carbon-Silicon Carbide Tribological Couples of Automotive Water Pump Seals

An experimental design based on the Taguchi method has been applied to optimize the use of a dynamic sealing element of water pump of automotives combustion engines. A carbon primary ring and a silicon carbide mating ring set up this dynamic sealing element. The aim of this work was to experimentally determine the crossed influence of the primary ring variant, the normal load, the surrounding, the mating ring finishing, and the rotational frequency on the dynamic friction coefficient and on the wear of carbon primary ring-silicon carbide mating ring tribological couples. The coefficient of dynamic friction and the wear depend on the design factors. They are also functions of the interactions between these experimental factors, from the implementation of an experimental design. The results obtained allow the optimal functioning condition to be determined and the best friction couple to be used for a given dynamic sealing application

HMDB: the Human Metabolome Database

The Human Metabolome Database (HMDB) is currently the most complete and comprehensive curated collection of human metabolite and human metabolism data in the world. It contains records for more than 2180 endogenous metabolites with information gathered from thousands of books, journal articles and electronic databases. In addition to its comprehensive literature-derived data, the HMDB also contains an extensive collection of experimental metabolite concentration data compiled from hundreds of mass spectra (MS) and Nuclear Magnetic resonance (NMR) metabolomic analyses performed on urine, blood and cerebrospinal fluid samples. This is further supplemented with thousands of NMR and MS spectra collected on purified, reference metabolites. Each metabolite entry in the HMDB contains an average of 90 separate data fields including a comprehensive compound description, names and synonyms, structural information, physico-chemical data, reference NMR and MS spectra, biofluid concentrations, disease associations, pathway information, enzyme data, gene sequence data, SNP and mutation data as well as extensive links to images, references and other public databases. Extensive searching, relational querying and data browsing tools are also provided. The HMDB is designed to address the broad needs of biochemists, clinical chemists, physicians, medical geneticists, nutritionists and members of the metabolomics community. The HMDB is available at

Synthesis and dynamics of double polymer networks based on microphase separation and metal-ligand interactions

Polymer gel and networks are fascinating, versatile soft materials ubiquitous in daily life and have high added-value applications. These networks are divided into two categories known as chemical networks and physical networks. Today the biggest challenge is to combine and control within the same material all distinct features that make them ideal for application. To address this challenge, a new type of polymer network has been developed to combine at least two dynamics in the same material, giving rise to a multiscale viscoelastic response under external stress or deformation field. Two interpenetrating polymer networks form double Networks (DN) with improved toughness and extensibility compared to the two individual networks. Our objective is to study the dynamics of model fully supramolecular double networks elastomers based on a combination of metal-ligand interactions and microphase separation. The first, long lifetime network is made from a microphase separated ABA triblock copolymer with a long central block and small outer blocks to ensure strong and stable association. The second, short lifetime, network is built from a short linear polymer bearing terpyridine ligands as side groups and is crosslinked by the addition of transition metal ions. The present thesis aims to develop thermoplastic elastomers with heat resistance. The designed supramolecular molecular polymers will be synthesized and investigated to understand the relationship between structure and linear viscoelastic response prior to being used in Double Dynamics Networks.(SC - Sciences) -- UCL, 202

Synthesis and dynamics of double polymer networks based on microphase separation and metal-ligand interactions

Polymer gel and networks are fascinating, versatile soft materials ubiquitous in daily life and have high added-value applications. These networks are divided into two categories known as chemical networks and physical networks. Today the biggest challenge is to combine and control within the same material all distinct features that make them ideal for application. To address this challenge, a new type of polymer network has been developed to combine at least two dynamics in the same material, giving rise to a multiscale viscoelastic response under external stress or deformation field. Two interpenetrating polymer networks form double Networks (DN) with improved toughness and extensibility compared to the two individual networks. Our objective is to study the dynamics of model fully supramolecular double networks elastomers based on a combination of metal-ligand interactions and microphase separation. The first, long lifetime network is made from a microphase separated ABA triblock copolymer with a long central block and small outer blocks to ensure strong and stable association. The second, short lifetime, network is built from a short linear polymer bearing terpyridine ligands as side groups and is crosslinked by the addition of transition metal ions. The present thesis aims to develop thermoplastic elastomers with heat resistance. The designed supramolecular molecular polymers will be synthesized and investigated to understand the relationship between structure and linear viscoelastic response prior to being used in Double Dynamics Networks.(SC - Sciences) -- UCL, 202

Le premier peuplement préhistorique des Amériques

International audienc

Yamada M. et Ono A., dir. (2014) — Lithic Raw Material Exploitation and Circulation in Prehistory: A Comparative Perspective in Diverse Palaeoenvironments

Gómez coutouly Yan axel. Yamada M. et Ono A., dir. (2014) — Lithic Raw Material Exploitation and Circulation in Prehistory: A Comparative Perspective in Diverse Palaeoenvironments. In: Bulletin de la Société préhistorique française, tome 111, n°4, 2014. pp. 755-757

Development of a fast method to interpret NMR spectra of proteins

L'identification des signaux RMN en terme d'acide aminé est connu sous le terme d'attribution. Cette étape est incontournable non seulement lorsque l'on veut déterminer la structure d'une protéine par RMN mais également lorsque l'on a une structure cristaEstablishing the correspondence between observed NMR signals and the nuclei in the covalent structure of a protein is termed assignment. This procedure is obligatory for the interpretation of NMR spectra in atom-specific terms, not only when one wishes t