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Résumé : Cette étude est consacrée à l'examen du rôle des entités numériques dans l'empowerment numérique au sein des environnements académiques, contribuant ainsi à l'amélioration significative de la qualité et de l'efficacité interactionnelle de ces plateformes. Ces entités agissent en tant que catalyseurs essentiels pour renforcer l'empowerment numérique de la communauté universitaire, en facilitant un accès accru aux ressources d'information. Elles proposent une interface dynamique qui permet l'accès au contenu numérique et aux services indispensables liés aux activités de recherche et aux résultats scientifiques, améliorant par là même les canaux de communication avec les entités numériques. Cette optimisation contribue substantiellement à l'amélioration de la production scientifique disponible et à l'expansion des opportunités éducatives ainsi que des services offerts. Mots-clés : Empowerment numérique, entités numériques, ressources informationnelles, environnement académique.

While the existence and functional role of class C G-protein-coupled receptors (GPCR) dimers is well established, there is still a lack of consensus regarding class A and B GPCR multimerization. This lack of consensus is largely due to the inherent challenges of demonstrating the presence of multimeric receptor complexes in a physiologically relevant cellular context. The C-X-C motif chemokine receptor 4 (CXCR4) is a class A GPCR that is a promising target of anticancer therapy. Here, we investigated the potential of CXCR4 to form multimeric complexes with other GPCRs and characterized the relative size of the complexes in a live-cell environment. Using a bimolecular fluorescence complementation (BiFC) assay, we identified the β2 adrenergic receptor (β2AR) as an interaction partner. To investigate the molecular scale details of CXCR4-β2AR interactions, we used a time-resolved fluorescence spectroscopy method called pulsed-interleaved excitation fluorescence cross-correlation spectroscopy (PIE-FCCS). PIE-FCCS can resolve membrane protein density, diffusion, and multimerization state in live cells at physiological expression levels. We probed CXCR4 and β2AR homo- and heteromultimerization in model cell lines and found that CXCR4 assembles into multimeric complexes larger than dimers in MDA-MB-231 human breast cancer cells and in HCC4006 human lung cancer cells. We also found that β2AR associates with CXCR4 multimers in MDA-MB-231 and HCC4006 cells to a higher degree than in COS-7 and CHO cells and in a ligand-dependent manner. These results suggest that CXCR4-β2AR heteromers are present in human cancer cells and that GPCR multimerization is significantly affected by the plasma membrane environment., Competing Interests: Competing interests statement:Several authors are employees of GPCR Therapeutics Inc., the sponsor of this research.

The planting of several species adapted to forests areas in the Saharan Atlas would allow one to better fight against the desertification of the vegetation cover of these fragile areas. Thanks to its rapid growth on degraded soils, Robinia pseudoacacia L. has an advantage in the repopulation of these areas undergoing desertification. Operation of this large-scale tree requires good control of germination conditions and growth of plants. The scarification of the seeds of Robinia pseudoacacia L. is necessary to allow the absorption of water by the seeds. Our results show that mechanical scarification with sulphuric acid (75minutes), boiling water (90minutes) and scarification by microwaves (700W) (105seconds) give the best germination rates. The presence of PEG 6000  in the imbibition's solutions reduces considerably the germination rate of the seeds of R. pseudoacacia L. A 70 % decrease in the optimal rate of germination is observed when the osmotic pressure of the imbibition solution is at -4.65 bar., (Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.)