Pourquoi des animations ?

L’offre de services accessibles à tous est une des missions fermement établies des bibliothèques, établissements publics. Mais quel est au juste le rôle des animations ? Lien entre collections, publics et territoires, elles seraient alors au coeur de ces missions. L\u27exemple nantais

L’architecte et l’usager

Nombre de communes et l’usager en Pays de la Loire ont construit récemment des équipements qui témoignent d’une belle dynamique architecturale. Nous avons demandé à cinq architectes de s’exprimer librement sur leur perception des attentes du public dans la conception d’un projet de bibliothèque

Le réseau nantais de lecture publique et l’accessibilité de tous les publics

Lors de la création d’une « médiathèque d’équilibre » visant à répondre à l’exigence de mixité sociale une réflexion a été menée très en amont du programme sur l’accessibilité à tous les publics. Floresca Guépin veut s’affirmer, sous ce rapport, comme établissement de référence

Testing the applicability of correlations between topographic slope and VS30 for Europe

In the past few years a series of articles have been published concerning the use of topographic slope from digital elevation models (DEMs) constructed through remote sensing (satellite imaging) to give first-order estimates of National Earthquake Hazards Reduction Program (NEHRP) site classes based on the average shear-wave velocity in the top 30 m, VS30 (Wald and Allen, 2007). We evaluate the potential applicability of these methods taking advantage of a large (706 sites) new database of measured and estimated VS30 values and their topographic slopes for locations in Europe and the Middle East. Novel statistical tests are performed to evaluate the predictive power of the procedure in this region. We evaluate the percentage of sites correctly classified/misclassified for each site class for active and stable regimes. We also analyze the marginal distributions of the input VS30 and slope values and their impact on the VS30-slope correlations and we evaluate whether the method performs better than does chance. We also consider the surface geology of sites and investigate whether differences in geology can help explain why certain sites are poorly classified by the method. Finally, we use the city of Thessaloniki, Greece, as a test case for comparison between the results of a recent microzonation and the site classes predicted by VS30-slope correlations. Our results show that the method does a better job than blind chance for all site classes in active regions, but only for class B (rock) and to a lesser extent class C (stiff soil) sites located in stable areas, although the conclusions for stable areas are based on limited data. We recommend that site classifications based on the VS30-slope correlations proposed by Wald and Allen (2007) be used only for regional or national (and not local or site-specific) first-order studies in active parts of Europe and only in the absence of other more detailed information, excluding sites inside small basins or those with special geological conditions that may affect results (e.g., flat-lying volcanic plateaus, carbonate rocks, continental glaciated terrain, or a coastal location if slope is not calculated using bathymetric data)

Amplicon rearrangements during the extrachromosomal and intrachromosomal amplification process in a glioma

International audienceThe mechanisms of gene amplification in tumour cells are poorly understood and the relationship between extrachromosomal DNA molecules, named double minutes (dmins), and intrachromosomal homogeneously staining regions (hsr) is not documented at nucleotide resolution. Using fluorescent in situ hybridization and whole genome sequencing, we studied a xenografted human oligodendroglioma where the co-amplification of the EGFR and MYC loci was present in the form of dmins at early passages and of an hsr at later passages. The amplified regions underwent multiple rearrangements and deletions during the formation of the dmins and their transformation into hsr. In both forms of amplification, non-homologous end-joining and microhomology-mediated end-joining rather than replication repair mechanisms prevailed in fusions. Small fragments, some of a few tens of base pairs, were associated in contigs. They came from clusters of breakpoints localized hundreds of kilobases apart in the amplified regions. The characteristics of some pairs of junctions suggest that at least some fragments were not fused randomly but could result from the concomi-tant repair of neighbouring breakpoints during the interaction of remote DNA sequences. This characterization at nucleotide resolution of the transition between extra-and intrachromosome amplifications highlights a hitherto uncharacterized organization of the amplified regions suggesting the involvement of new mechanisms in their formation

Fracture behaviour of a Fe–22Mn–0.6C–0.2V austenitic TWIP steel

International audienceThe mechanical behaviour of a 22Mn-0.6C-0.2V austenitic TWIP steel has been extensively characterised for a variety of strain ratios (from shear to biaxial stretching) using smooth and notched specimens. A constitutive model involving a non-isotropic yield function together with isotropic and/or kinematic hardening satisfactorily represented the experimental database. It was used to estimate local stress and strain fields and to derive a fracture criterion based on the equivalent stress and Lode angle that were expressed to be consistent with the constitutive equations describing the plastic flow behaviour. A weak dependence on hydrostatic stress further improves prediction of fracture initiation, with an average standard error of less than 5% over ten different mechanical tests