L'Université et la ville de l'inscription locale aux stratégies de réseaux, Présentation des recherches

Ce document est un résumé d'un ensemble de neuf rapports de recherche. Il est composé de 9 parties avec une présentation générale. L'ensemble fait 34 pagesCe document présente de façon résumée les principaux résultats obtenus après 3 années de recherche (1990-1993) financée par le Plan Urbain, dans le cadre de l'appel d'offre recherche liée à l'opération Université 2000. Cette recherche a porté sur les relations ville université établies dans le cadre de l'agglomération de Tours à cette époque. Ll'ensemble des résultats et informations forme un tout qui n'existait pas antérieurement et ce en particulier sur l'organisation universitaire et son fonctionnement en tant que système de Formation. A cette époque, l'activité du groupe fut également l'élément moteur du repositionnement du fait universitaire dans le discours urbain par l'apparition d'un concept nouveau articulatoire soit la notion de "ville universitaire" définie comme ressource majeure au développement local. Si cette figure symbolique s'est imposée à la fin de la recherche, elle a plus contribué à définir un ensemble de problèmes posé par l'actualisation de cette figure, que la résolution de questions immédiates. Sur le plan de l'organisation spatiale, l'identité universitaire reste une dimension à affirmer d'autant plus que les deux pôles majeurs qui structurent la position de l'université dans la ville sont et seront encore soumis à un ensemble d'événements aléatoires qui participeront de leur insertion dans le tissu urbain. L'université ne forme pas un tout homogène. L'étude des comportements estudiantins par rapport à la ville nous le démontre. L'intégration recherchée doit être basée sur une exploitation des singularités. Le multisite tourangeau est un facteur de déploiement des étudiants dans la Ville. Les recherches menées sur le logement et les déplacements nous fournissent un ensemble de données qui pourront être engagées à la fois dans une politique globale du logement et un meilleur couplage entre sites universitaires et pôles urbains des activités étudiantes de loisir, de culture et de sport. L'université est avant tout un système de formations. Ce n'est pas un système structurellement et fonctionnellement homogène. L'université doit être définie comme un champ de ressources diversifiées autorisant l'accession aux formations du supérieur à un ensemble d'étudiants qui ont des origines sociales multiples et qui ont eu antérieurement des cursus de formations variés. Le rôle social de l'université est à rechercher dans cette diversité. Enfin l'université de Tours est une université moyenne et jeune. Avec l'usage de l'outil réseau d'universités, qu'il reste à définir même s'il existe, elle peut participer à l'émergence d'une région du centre ouest avec un capital universitaire autonome et être un élément moteur pour l'aménagement de ce territoire

The rose of the Sainte-Chapelle in Paris: sophisticated stained glasses for late medieval painters

The restoration of the rose (15th century) of the Sainte-Chapelle in Paris, France, offered a unique opportunity to investigate the color and chemical composition of these emblematic medieval French stained glasses with non-destructive analyses. The obtained results are aimed at complementing the knowledge from art historians and thus together trying to compensate for the total absence of archives on the construction of the rose. Comparison with the glasses of the nave (13th century) reveals an important evolution of the aesthetics based on new types of glasses: new colors and extensive use of flashed glass. The systematic study of the chemical composition of both sides of each glass piece revealed that about half of the studied glasses were flashed. For non-flashed glasses, this comparison allowed evaluating the influence of glass surface weathering, although very moderate, on the composition variability. In light of the variability criteria, the multivariate analysis of the chemical composition allowed inferring that most glasses originate from the same production glasshouse. The new colors result from the original composition of flashed glass, allowing superimposing otherwise incompatible redox states of the coloring transition elements. The comparison with the glasses of the nave reveals the glass technology evolution that occurred over two centuries and allowed the production of new glasses for the medieval glaziers at the eve of the Parisian Renaissance

The rose of the Sainte-Chapelle in Paris: sophisticated stained glasses for late medieval painters

The restoration of the rose (15th century) of the Sainte-Chapelle in Paris, France, offered a unique opportunity to investigate the color and chemical composition of these emblematic medieval French stained glasses with non-destructive analyses. The obtained results are aimed at complementing the knowledge from art historians and thus together trying to compensate for the total absence of archives on the construction of the rose. Comparison with the glasses of the nave (13th century) reveals an important evolution of the aesthetics based on new types of glasses: new colors and extensive use of flashed glass. The systematic study of the chemical composition of both sides of each glass piece revealed that about half of the studied glasses were flashed. For non-flashed glasses, this comparison allowed evaluating the influence of glass surface weathering, although very moderate, on the composition variability. In light of the variability criteria, the multivariate analysis of the chemical composition allowed inferring that most glasses originate from the same production glasshouse. The new colors result from the original composition of flashed glass, allowing superimposing otherwise incompatible redox states of the coloring transition elements. The comparison with the glasses of the nave reveals the glass technology evolution that occurred over two centuries and allowed the production of new glasses for the medieval glaziers at the eve of the Parisian Renaissance

In Vitro Recombination Catalyzed by Bacterial Class 1 Integron Integrase IntI1 Involves Cooperative Binding and Specific Oligomeric Intermediates

Gene transfer via bacterial integrons is a major pathway for facilitating the spread of antibiotic resistance genes across bacteria. Recently the mechanism underlying the recombination catalyzed by class 1 integron recombinase (IntI1) between attC and attI1 was highlighted demonstrating the involvement of a single-stranded intermediary on the attC site. However, the process allowing the generation of this single-stranded substrate has not been determined, nor have the active IntI1•DNA complexes been identified. Using the in vitro strand transfer assay and a crosslink strategy we previously described we demonstrated that the single-stranded attC sequences could be generated in the absence of other bacterial proteins in addition to IntI. This suggests a possible role for this protein in stabilizing and/or generating this structure. The mechanism of folding of the active IntI•DNA complexes was further analyzed and we show here that it involves a cooperative binding of the protein to each recombination site and the emergence of different oligomeric species specific for each DNA substrate. These findings provide further insight into the recombination reaction catalyzed by IntI1

Preparation of Group I Introns for Biochemical Studies and Crystallization Assays by Native Affinity Purification

The study of functional RNAs of various sizes and structures requires efficient methods for their synthesis and purification. Here, 23 group I intron variants ranging in length from 246 to 341 nucleotides—some containing exons—were subjected to a native purification technique previously applied only to shorter RNAs (<160 nucleotides). For the RNAs containing both exons, we adjusted the original purification protocol to allow for purification of radiolabeled molecules. The resulting RNAs were used in folding assays on native gel electrophoresis and in self-splicing assays. The intron-only RNAs were subjected to the regular native purification scheme, assayed for folding and employed in crystallization screens. All RNAs that contained a 3′ overhang of one nucleotide were efficiently cleaved off from the support and were at least 90% pure after the non-denaturing purification. A representative subset of these RNAs was shown to be folded and self-splicing after purification. Additionally, crystals were grown for a 286 nucleotide long variant of the Clostridium botulinum intron. These results demonstrate the suitability of the native affinity purification method for the preparation of group I introns. We hope these findings will stimulate a broader application of this strategy to the preparation of other large RNA molecules

Cerebral small vessel disease genomics and its implications across the lifespan

White matter hyperintensities (WMH) are the most common brain-imaging feature of cerebral small vessel disease (SVD), hypertension being the main known risk factor. Here, we identify 27 genome-wide loci for WMH-volume in a cohort of 50,970 older individuals, accounting for modification/confounding by hypertension. Aggregated WMH risk variants were associated with altered white matter integrity (p = 2.5×10-7) in brain images from 1,738 young healthy adults, providing insight into the lifetime impact of SVD genetic risk. Mendelian randomization suggested causal association of increasing WMH-volume with stroke, Alzheimer-type dementia, and of increasing blood pressure (BP) with larger WMH-volume, notably also in persons without clinical hypertension. Transcriptome-wide colocalization analyses showed association of WMH-volume with expression of 39 genes, of which four encode known drug targets. Finally, we provide insight into BP-independent biological pathways underlying SVD and suggest potential for genetic stratification of high-risk individuals and for genetically-informed prioritization of drug targets for prevention trials.Peer reviewe

Stroke genetics informs drug discovery and risk prediction across ancestries

Previous genome-wide association studies (GWASs) of stroke — the second leading cause of death worldwide — were conducted predominantly in populations of European ancestry1,2. Here, in cross-ancestry GWAS meta-analyses of 110,182 patients who have had a stroke (five ancestries, 33% non-European) and 1,503,898 control individuals, we identify association signals for stroke and its subtypes at 89 (61 new) independent loci: 60 in primary inverse-variance-weighted analyses and 29 in secondary meta-regression and multitrait analyses. On the basis of internal cross-ancestry validation and an independent follow-up in 89,084 additional cases of stroke (30% non-European) and 1,013,843 control individuals, 87% of the primary stroke risk loci and 60% of the secondary stroke risk loci were replicated (P < 0.05). Effect sizes were highly correlated across ancestries. Cross-ancestry fine-mapping, in silico mutagenesis analysis3, and transcriptome-wide and proteome-wide association analyses revealed putative causal genes (such as SH3PXD2A and FURIN) and variants (such as at GRK5 and NOS3). Using a three-pronged approach4, we provide genetic evidence for putative drug effects, highlighting F11, KLKB1, PROC, GP1BA, LAMC2 and VCAM1 as possible targets, with drugs already under investigation for stroke for F11 and PROC. A polygenic score integrating cross-ancestry and ancestry-specific stroke GWASs with vascular-risk factor GWASs (integrative polygenic scores) strongly predicted ischaemic stroke in populations of European, East Asian and African ancestry5. Stroke genetic risk scores were predictive of ischaemic stroke independent of clinical risk factors in 52,600 clinical-trial participants with cardiometabolic disease. Our results provide insights to inform biology, reveal potential drug targets and derive genetic risk prediction tools across ancestries

Pharmacomodulation d'agents inhibiteurs de pompes d'efflux bactériennes (application à la mise au point de nouveaux anti-infectieux)

BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF

Underpotential deposition of silver on gold from deep eutectic electrolytes

The electrochemical behavior of Ag(I) in choline chloride-urea medium (ChCl-U) has been investigated at a gold electrode using cyclic voltammetry. Cyclic voltammograms revealed a diffusion limited reduction wave coupled on the reverse sweep with an oxidation wave that corresponds to the dissolution of a bulk deposit. Beside these main peaks, we have highlighted other peaks at potentials more positive than the thermodynamic potential of silver bulk deposition. Experiments at various potential scan rates have indicated that, contrary to the main reduction peak, these peaks are indicative of a surface process that corresponds to an underpotential deposition (upd) of silver. The absence of upd at glassy carbon or platinum electrodes in ChCl-U has ruled out the influence of silver speciation on the existence of the upd process. The occurrence of silver upd on gold is moreover not linked to the nature of the H-bond donor (urea, ethylene glycol or oxalic acid) of the choline choride DES.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Silver electrodeposition on gold from a choline chloride - urea electrolyte

info:eu-repo/semantics/nonPublishe