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Repair of oxidized methionine residues in the chaperone Spy maintains periplasmic proteostasis under chlorite stress in Escherichia coli
No full textInternational audienceThe bacterial cell envelope is exposed to various stresses, including oxidative stress caused by different types of oxidants, such as reactive oxygen species (ROS) and reactive chlorine species (RCS). In Escherichia coli, the reduction of chlorate into chlorite, a toxic RCS compound, induces the expression of the MsrPQ system, which repairs periplasmic proteins oxidized at methionine residues (methionine sulfoxide, Met-O). In this study, using a proteomic-based approach, we show that chlorite stress also triggers the overproduction of the periplasmic molecular chaperone Spheroplast Protein Y (Spy). This response is mediated by the activation of the BaeSR two-component system. Furthermore, both in vivo and in vitro evidence reveal that Spy’s susceptibility to oxidation is critical for its chaperone activity. We demonstrate that the MsrPQ repair system ensures Spy’s functionality by reducing its Met-O, thereby safeguarding its role in periplasmic protein homeostasis. Overall, this work reveals Spy as a key target of chlorite-induced oxidative damage and underscores the essential role of MsrPQ in preserving periplasmic protein quality control
Study of charm mixing and CP violation with decays
No full textInternational audienceA study of charm mixing and CP violation in decays is performed using data collected by the LHCb experiment in proton-proton collisions from 2015 to 2018, corresponding to an integrated luminosity of 6. The ratio of promptly produced to decay rates is measured as a function of decay time, both inclusive over phase space and in bins of phase space. Taking external inputs for the mixing parameters and allows constraints to be obtained on the hadronic parameters of the charm decay. When combined with previous measurements from charm-threshold experiments and at LHCb, improved knowledge is obtained for these parameters, which is valuable for studies of the angle of the Unitarity Triangle. An alternative analysis is also performed, in which external inputs are taken for the hadronic parameters, and the mixing parameters are determined, including and , which are nonzero in the presence of CP violation. It is found that , , and . These results are consistent with previous measurements and the hypothesis of \CP conservation
Les spécificités des quatre temps de l'Appareil Psychique Groupal dans les groupes thérapeutiques de patients psychotiques
No full textCet article propose l'exploration théorico-clinique des spécificités des quatre temps constitutifs de l'Appareil psychique groupal dans les groupes thérapeutiques de patients psychotiques. Nous souhaitons étudier les processus psychiques à l'oeuvre au sein de ces quatre moments à la lumière du fonctionnement intrapsychique et intersubjectif des sujets psychotiques. Nous soutenons quatre hypothèses de travail, chacune étant spécifique à un des quatre temps de l'Appareil psychique groupal. Afin d'étayer notre propos, nous nous appuierons sur l'analyse de plusieurs séances d'un groupe de psychodrame psychanalytique, constitué de cinq patients diagnostiqués « schizophrènes paranoïdes » et hospitalisés au sein d'une clinique psychiatrique
L’enseignant de demain dans le supérieur : architecte des savoirs à l’ère de l’IA générative
No full textInternational audienceSince the public release of ChatGPT in 2022, generative artificial intelligence (GenAI) has been profoundly transforming higher education in management. Based on a qualitative study conducted with faculty members, this article analyzes emerging pedagogical uses of GenAI: course design, instructional delivery, and student assessment. GenAI supports the individualization of learning, the development of interactive materials, and the evolution of curriculum frameworks. However, these opportunities also come with significant challenges: superficial learning, dependence on the tool, content uniformity, and ethical and data security risks. The article advocates for a reflective and critical approach to GenAI usage. It emphasizes that while GenAI cannot replace the human dimension of teaching, it can serve as a powerful lever to reinvent pedagogical practices—provided its use is collectively framed. In this context, the teacher is called upon to become an “architect of knowledge” within a rapidly evolving technological environment.Depuis l’ouverture de ChatGPT au public en 2022, l’intelligence artificielle générative (IAg) transforme en profondeur l’enseignement supérieur en gestion. À partir d’une étude qualitative menée auprès d’enseignants, cet article analyse les usages pédagogiques émergents de l’IAg : création de cours, animation pédagogique et évaluation. L’IAg favorise l’individualisation des apprentissages, la conception de supports interactifs, et l’évolution des référentiels de formation. Mais ces opportunités s’accompagnent de défis majeurs : apprentissage superficiel, dépendance à l’outil, uniformisation des productions, et risques éthiques et de sécurité. L’article plaide pour une posture réflexive et critique dans l’usage de l’IAg. Il souligne que l’IAg ne saurait remplacer la dimension humaine de la pédagogie, mais qu’elle peut devenir un levier puissant pour réinventer les pratiques, à condition d’en baliser collectivement les usages. L’enseignant du supérieur est ainsi invité à devenir un « architecte des savoirs », dans un environnement technologiqueen mutation rapide
Vague réformatrice pour les redevances perçues au profit des agences de l'eau dès 2025
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Model-driven optimization of the scheduling of a novel anti-cancer prodrug administered subcutaneously
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One-dimensional optical compression and backpropagation of particle digital in-line holograms
No full textInternational audienceThis work explores the possibility of using cylindrical lenses in digital in-line holography to reduce particle hologram imprint and cross-interference on the camera sensor. Experimental results on sprayed and levitated droplets, together with simulations using Rayleigh-Sommerfeld integrals and ABCD analysis, confirm the feasibility of this compression method for spherical particles. However, it turns out that, when using a back-propagation method to reconstruct the particle field, reducing the fill rate of the camera sensor does not in itself improve the quality of the particle field reconstruction. It is the asymmetric magnification of the optical system that enables this improvement, transforming the twin particle probleminto a two half-twin particles problem. The latter have less impact on the reconstruction process, allowing the statistics to be improved. This advantage increases with the magnification factor of the optical system. The authors believe that this optical method could be even more interesting for parametric inversion methods used for full volumetric reconstruction of particle field
