Artistic creativity and use of symbols appear as a fundamental need for the social life. The oldest archaeologically demonstrated symbolic activity is linked to the first anatomically modern man (Homo sapiens sapiens). The scientific objective of our project entitled “The Arts of Prehistory and the Cultural Dynamics of Societies before Writing” is a better understanding of the relations between art and society in different contexts, based on actual cases issued from fieldworks of the participants. These works are dealing with all chronological periods (from Upper Palaeolithic to sub-actual times), all types of arts (from monumental rock art to portable art and ornaments), and various types of societies (nomadic or semi-nomadic hunters-gatherers, sedentary pastoralists and farmers). For the first time, a study will tackle prehistoric art on a very large diachronic and geographic scale, in a cooperative manner, in order to discover specificities in each rock art and to highlight simultaneously their structural similarities. The art of caves and rock shelters during the European Upper Palaeolithic, the Spanish Levantine art, Bronze age art from Mont Bego and Mongolia, rock arts from Sahara, Chad, Namibia, Australia, etc. will provide a large set of unpublished data, sufficiently varied to address essential questions such as the creative act in its context (identification of expertise peculiar to an artist or to a group, painting techniques, “operational sequence”), the place of art in society as “cultural marker” (dynamics of exchange between groups, phenomena of diffusion and borrowing, diachrony) or as “territorial marker” (cultural identity of local groups) and allow us to consider rock art as a structured system of communication, obeying to codes, and to apply automatic procedures of treatment of symbolic data. The relation between image and language and the question of the appearance of figurative art will be addressed with the collaboration of linguists and neuropsychologists.

The potential of RNA molecules to exert regulatory functions in conjunction with auxiliary proteins has only recently been recognized and has emerged as a major field in molecular biology and biomedical research. In enterobacteria, such molecules constitute an ever-growing class of regulators of stress responses, metabolism and virulence. The majority of the known bacterial trans-encoded small RNAs (sRNAs) negatively regulate their target mRNAs by base pairing. This interaction leads to inhibition of translation and/or degradation of mRNA reducing the protein levels of the target gene. Whilst the first mechanism has ample experimental support, the messenger destabilization process, which is often regarded as a downstream consequence of generating untranslatable messengers, remains controversial in the absence of supporting data. However, a recent study strongly questions this assumption by reporting Salmonella MicC-ompD as the first example of RNase E dependent destabilization of an mRNA without primary effects on translation. After a decade of intensive research, we are beginning to have a full appreciation of the importance and prevalence of sRNAs in numerous and diverse means of gene regulation. Nevertheless, the molecular mechanism underlying sRNA-induced mRNA decay is largely unknown and has yet to be characterized in significant detail. The proposed research will add to our knowledge to explore it by using in vivo and in vitro experimental approaches.

Le but de ce projet est de construire un nouveau modèle thermodynamique pour le calcul de la distribution de matière dans les aérosols atmosphériques. Nous proposons de mettre en ?uvre les méthodes et concepts développés dans la modélisation des interactions eaux-roches dans les Sciences de la Terre: thermodynamique de l'équilibre des systèmes ouverts (potentiels thermodynamiques généralisés), modèles performants des solutions aqueuses ioniques et prise en compte des composés organiques. L'approche suivie vise à simuler le comportement des aérosols dans l'atmosphère en fonction de paramètres tels que l'humidité relative et le rôle des composés organiques et inorganiques, et à évaluer leurs conséquences sur le comportement chimique et radiatif des aérosols. C'est un projet commun au Laboratoire des Mécanismes de Transfert en Géologie (Christophe Monnin, UMR 5563, Observatoire Midi-Pyrénées, Toulouse) et au Laboratoire d'Aérologie (Robert Rosset et Catherine Liousse, UMR 5560, Observatoire Midi-Pyrénées, Toulouse).

This fundamental research project aims at developing thermal nanocharacterization techniques with a high spatial and temporal resolution based on the use of bistable nanostructured molecular materials with predictable and controllable physical properties. This bistability is accompanied by a spectacular change of various physical properties (magnetic, mechanical and optical). Depending on the size and the composition of the molecular materials, the thermally activated spin state switching can occur with a rate from the nanosecond to the microsecond (around room temperature) enabling a very fast temperature characterization. In this project, metal nanowires, Joule-heated under various current injections in terms of amplitude and frequency modulation, will be used as thermal sources to explore a wide range of spatial and temporal windows and to validate the proposed techniques for solid and liquid phases. Three major challenges will be considered to attain on-chip single nanoparticle detection to reach the targeted spatial and temporal resolution (less than 100 nm and a few hundreds of nanoseconds): (i) Synthesis of molecular probes and fabrication of metallic nanosources along with their concomitant use to design functional thermal nanodevices : • Bistable molecular probes will be synthesized as (re)dispersable nanoparticles with controlled size, shape, composition, surface chemistry and physical properties. The nanoparticle synthesis will be carried out by different methods including the use of capping ligands, surfactants, polymers and host matrices. The nanoparticles will be characterized using static and time-resolved spectroscopic methods. • Metallic nanowires will be fabricated by e-beam lithography or metal electrodeposition into porous membranes. In the latter case, dedicated assembly techniques, based on dielectrophoresis or capillary-driven flows, will be used to obtain functional nanowires-based thermal nanodevices. • The molecular probes will be attached on the surface of metallic nanowires for thermal characterization in solid phase using directed assembly methods. Alternatively, colloidal suspension of molecular probes will be used for thermal characterization in liquid phases. (ii) Modeling and simulation : • Physical properties of nanostructured bistable molecular materials will be simulated using microscopic elastic models on account of the elastic origin of the inter-molecular interactions in these materials. • Heat transfer within metallic nanowires in steady-state and transient regimes for solid and liquid phases will be obtained both from analytical approaches or finite element methods. (iii) Thermal nanocharacterization : • In a first phase, fluorescence techniques will be developed by taking advantage of the fluorescence quenching effect which takes place within a given range of emission wavelengths for fluorophores in the presence of bistable molecular materials during spin transition. It is interesting to note that in many cases one can observe spectral changes in opposite directions within the same material (depending on the probe wavelength) providing thus a straightforward way for two-color measurements. In order to achieve single-particle detection we will design systems with efficient (resonant) energy transfer and implement state-of-the art detection techniques (colloidal lenses, FCS). • In a second, complementary approach, surface Plasmon resonance (SPR)-based detection techniques will be employed. To this aim, core-shell systems comprising a nobel metal (Au, Ag) core and a bistable shell will be designed, which are expected to display intense light scattering with strong temperature dependence. • In parallel, thermal characterization based on electrical measurements will be performed to get additional information on the transient regime.