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International audience; Different additive manufacturing (AM) technologies such as L-PBF and DED do become really attractive for both repair and 3D part manufacturing. In particular, extensive work is in progress for the non-weldable nickel-based superalloys which tend to exhibit cracks due to residual stresses build-up during AM thermal cycles. Within the framework of the project FAPS conducted at Université Paris-Saclay, the present investigation will highlight the processing conditions and build-up strategy that produce crack-free specimens for alloy AD730®. The latter was developed by Aubert & Duval for cast&wrought gas turbine applications. In this work, a comparison between such conventional processing and AM will be provided in terms of mechanical performance. The results clearly show an anisotropic behaviour related to the sharp crystallographic texture induced by the epitaxial grain growth. The results will be discussed, with a perspective analysis of maturity for this AM processedmaterial, the process robustness, the potential technological developments and application prospects.; Différentes technologies FA telles que L-PBF et DED deviennent réellement attractives pour à la fois de la réparation et de la fabrication de pièces 3D. En particulier, un travail important est en cours pour les superalliages base Ni non soudables qui tendent à se fissurer en raison d’une augmentation des contraintes résiduelles lors des cycles thermiques FA. Dans le cadre du projet FAPS mené à Paris-Saclay, ces travaux vont mettre en exergue les conditions de process et de stratégie de construction qui produisent des échantillons sans fissures pour l’alliage AD730. Ce dernier a été développé par Aubert&Duval pour des applications coulé+forgé dans les turbines aéronautiques. Dans ce travail, on présentera une comparaison entre un tel procédé conventionnel et la FA en termes de performance mécanique. Les résultats montrent clairement un comportement anisotrope relié à la forte texture cristallographique induite par la croissance épitaxiale des grains. On discutera des résultats, avec en perspective l’analyse de la maturité de ce matériau issu de FA, la robustesse du procédé, les développements technologiques potentiels et les applications prospectives.

International audience

Background: Though women increasingly make up the majority of medical-school and other science graduates, they remain a minority in academic biomedical settings, where they are less likely to hold leadership positions or be awarded research funding. A major factor is the career breaks that women disproportionately take to see to familial duties. They experience a related, but overlooked, hurdle upon their return: they are often too old to be eligible for 'early-career researcher' grants and 'career-development' awards, which are stepping stones to leadership positions in many institutions and which determine the demographics of their hierarchies for decades to come. Though age limits are imposed to protect young applicants from more experienced seniors, they have an unintended side effect of excluding returning workers, still disproportionately women, from the running. Methods: In this joint effort by the European Society of Clinical Microbiology and Infectious Diseases, the Federation of European Microbiological Societies, the Infectious Disease Society of America, the International Society for Infectious Diseases and the Swiss Society for Infectious Diseases, we invited all European Congress of Clinical Microbiology and Infectious Diseases-affiliated medical societies and funding bodies to participate in a survey on current 'early-career' application restrictions and measures taken to provide protections for career breaks. Recommendations: The following simple consensus recommendations are geared to funding bodies, academic societies and other organizations for the fair handling of eligibility for early-career awards: 1. Apply a professional, not physiological, age limit to applicants. 2. State clearly in the award announcement that career breaks will be factored into applicants' evaluations such that: • Time absent is time extended: for every full-time equivalent of career break taken, the same full-time equivalent will be extended to the professional age limit. • Opportunity costs will also be taken into account: people who take career breaks risk additional opportunity costs, with work that they did before the career break often being forgotten or poorly documented, particularly in bibliometric accounting. Although there is no standardized metric to measure additional opportunity costs, organizations should (a) keep in mind their existence when judging applicants' submissions, and (b) note clearly in the award announcement that opportunity costs of career breaks are also taken into account. 3. State clearly that further considerations can be undertaken, using more individualized criteria that are specific to the applicant population and the award in question. The working group welcomes feedback so that these recommendations can be improved and updated as needed.

The thesis presented in this manuscript offers a methodological framework used to design, implement and validate a virtual learning environment for mechanical engineering. It takes advantage of the recent advances in the domain of virtual reality to build upon existing research in the field of virtual environments for learning. This work is focused on specific interaction modalities leveraged in a virtual training for teaching learners to operate actual machine tools. Application of this research leads to the development of a prototype in which the primary findings are illustrated and described through the following steps : preparation of a pedagogical scenario, technical and ergonomic choices guiding the implementation of the application, design of an immersive and interactive virtual environment for learning, and finally the validation of such an application. Experimentation with teachers and student in the field of mechanical engineering brought to light the genuine interest from the teachers or the tool they tested and allowed us to validate our approach upon the success factors for learning game : usability, acceptability and utility.; La thèse présentée dans ce manuscrit propose un cadre méthodologique pour l'élaboration et la validation d'un outil de formation au génie mécanique en réalité virtuelle. Elle s'inscrit dans les avancées récentes du domaine de la réalité virtuelle et s'intègre à la recherche sur les environnements virtuels pour l'apprentissage humain. Les travaux présentés se focalisent en particulier sur les modalités d'interaction spécifiques à mettre en oeuvre pour permettre à un opérateur de se former virtuellement à l'utilisation de machines-outils. L'application de ces recherches donne lieu à la réalisation d'un prototype dans lequel les principaux résultats y sont illustrés et décrits à travers les étapes suivantes : la préparation d'un scénario pédagogique, les choix techniques et ergonomiques guidant le développement de l'application, la mise en place d'un environnement virtuel immersif et interactif pour l'apprentissage, et enfin la validation d'une telle application. Les expérimentations menées avec des enseignants et des étudiants en génie mécanique ont mis en évidence un grand intérêt pour l'outil proposé de la part des enseignants et ont permis de valider l'approche utilisée suivant les facteurs de succès des jeux d'apprentissages : utilisabilité, acceptabilité et utilité.

The thesis presented in this manuscript offers a methodological framework used to design, implement and validate a virtual learning environment for mechanical engineering. It takes advantage of the recent advances in the domain of virtual reality to build upon existing research in the field of virtual environments for learning. This work is focused on specific interaction modalities leveraged in a virtual training for teaching learners to operate actual machine tools. Application of this research leads to the development of a prototype in which the primary findings are illustrated and described through the following steps : preparation of a pedagogical scenario, technical and ergonomic choices guiding the implementation of the application, design of an immersive and interactive virtual environment for learning, and finally the validation of such an application. Experimentation with teachers and student in the field of mechanical engineering brought to light the genuine interest from the teachers or the tool they tested and allowed us to validate our approach upon the success factors for learning game : usability, acceptability and utility., La thèse présentée dans ce manuscrit propose un cadre méthodologique pour l'élaboration et la validation d'un outil de formation au génie mécanique en réalité virtuelle. Elle s'inscrit dans les avancées récentes du domaine de la réalité virtuelle et s'intègre à la recherche sur les environnements virtuels pour l'apprentissage humain. Les travaux présentés se focalisent en particulier sur les modalités d'interaction spécifiques à mettre en oeuvre pour permettre à un opérateur de se former virtuellement à l'utilisation de machines-outils. L'application de ces recherches donne lieu à la réalisation d'un prototype dans lequel les principaux résultats y sont illustrés et décrits à travers les étapes suivantes : la préparation d'un scénario pédagogique, les choix techniques et ergonomiques guidant le développement de l'application, la mise en place d'un environnement virtuel immersif et interactif pour l'apprentissage, et enfin la validation d'une telle application. Les expérimentations menées avec des enseignants et des étudiants en génie mécanique ont mis en évidence un grand intérêt pour l'outil proposé de la part des enseignants et ont permis de valider l'approche utilisée suivant les facteurs de succès des jeux d'apprentissages : utilisabilité, acceptabilité et utilité.

We study two separate models for yeast cell-cell communication. Each model consists of a coupled system of two non-linear, non-local equations in one dimension of space. The first model describes the two cells in the transversal direction, orthogonal to the membrane, whereas the second model describes the two cells in the tangential direction, along the membrane. We study long time dynamics for each model, ranging from convergence to stable steady states (bistability in model 1), to possible finite time blow-up (formation of singularity in model 2). The biological interpretation of the mathematical results is discussed.

We present here a population structured model to describe the dynamics of macrophage cells. The model involves the interactions between modified LDL, monocytes/macrophages, cytokines and foam cells. The key assumption is that the individual macrophage dynamics depends on the amount of lipoproteins it has internalized. The obtained renewal equation is coupled with an ODE describing the lipoprotein dynamics. We first prove global existence and uniqueness for the nonlinear and nonlocal system. We then study long time asymp-totics in a particular case describing silent plaques which undergo periodic rupture and repair. Finally we study long time asymptotics for the nonlinear renewal equation obtained when considering the steady state of the ODE. and we prove that ....

We investigate two phenomena occuring in planetary cores, and that may be related to magnetic field generation.1) flows driven by precession in spherical shells2) stability of the double-diffusive system in a rotating spherical shell.We find that it is difficult to obtain precession dynamos in spheres at low viscosity.We also highligh the possibility for thermo-solutal convection in case of a sub-adiabatic heat flux at the core-mantle boundary.