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The Dunhuang Manuscripts as a Stepping Stone toward Mass Digitization of China’s Literary Heritage
No full textInternational audienceChina's literary heritage, comprising over 200,000 titles, millions of archival documents, and hundreds of thousands of epigraphic and manuscript materials, ranks among the largest in the world. Despite long-standing efforts, the digitization of these materials remains a labor-intensive and costly process. Recently, a team of sinologists and AI specialists, including myself, joined forces to leverage the latest advancements in AI technology to improve this process. After publishing a set of open-source transcription models, in collaboration with the Bibliothèque national de France and the British Library, we recently began working on the Chinese manuscripts of Dunhuang. Through this project, we aim not only to create a complete transcription of the manuscripts but also to produce richly annotated texts that will significantly improve access to the manuscripts. In this presentation, I will discuss the challenges of digitizing Chinese historical documents and demonstrate how these manuscripts, created more than a thousand years ago on the edge of the Gobi Desert, enable us to make significant breakthroughs in digitizing China's vast textual legacy and advance the state of the art in AI.</div
Impact on silica particle physical characteristics of co-condensed alkoxide precursors
No full textInternational audienceUnderstanding the condensation process of two precursors in the Stöber process is crucial to enhance the complexity and applicability of silica hybrids. We present a simple and effective method to prepare functional silica hybrid particles with tunable properties through the co-condensation of tetraethoxysilane and an organoalkoxide precursor using a modified Stöber process. Three organoalkoxide precursors have been studied: (3-mercaptopropyl)triethoxysilane, (3-cyanopropyl)triethoxysilane, and (3-aminopropyl)triethoxysilane. All three investigated systems produce functional silica hybrid particles, as confirmed by various characterization techniques. Scanning transmission electron microscopy and nitrogen sorption analysis demonstrated that features such as the microstructure could be tailored by the careful selection of the second precursor. A drastic increase in the specific surface area can be obtained with 3cyanopropyltriethoxysilane: 270 m2 g−1 compared to 17 m2 g−1 in the unfunctionalized silica particles. Other important characteristics such as the degree of condensation and surface charge can also be influenced by precursor choice. The enhanced reactivity of 3-aminopropyltriethoxysilane yields a higher degree of particle functionalization. Nanoscale chemical mapping has been performed using energy-dispersive Xray spectroscopy and Auger spectroscopy. Homogeneous distribution of the functionalities within the hybrid particles occurs. The present work gives tools to easily tailor functional silica particles, thus providing simple ways to tune their properties to meet a wide range of applications
Factors shaping vaginal microbiota long-term community dynamics in young adult women
No full textInternational audienceThe vaginal microbiota is known to affect women's health. Yet, there is a notable paucity of highresolution follow-up studies lasting several months, which would be required to interrogate the longterm dynamics and associations with demographic and behavioural covariates. Here, we present a high-resolution longitudinal cohort study of 125 women, followed for a median duration of 8.6 months, with a median of 11 samples collected per woman. Using a hierarchical Bayesian Markov model, we characterised the patterns of vaginal microbiota community persistence and transition, simultaneously estimated the impact of 16 covariates and quantified individual variability among women. We showed that "optimal" (Community State Type (CST) I, II, and V) and "sub-optimal" (CST III) communities are more stable over time than "non-optimal" (CST IV) ones. Furthermore, we found that some covariates -most notably alcohol consumption -impacted the probability of shifting from one CST to another. We performed counterfactual simulations to confirm that alterations of key covariates, such as alcohol consumption, could shape the prevalence of different microbiota communities in the population. Finally, our analyses indicated that there is a relatively canalised pathway leading to the deterioration of vaginal microbiota communities, whereas the paths to recovery can be highly individualised among women. In addition to providing one of the first insights into vaginal microbiota dynamics over a year, our study showcases a novel application of a hierarchical Bayesian Markov model to clinical cohort data with many covariates. Our findings pave the way for an improved mechanistic understanding of microbial dynamics in the vaginal environment and the development of novel preventative and therapeutic strategies to improve vaginal health
Architecture, modernité, modernisation: Leçon inaugurale prononcée au Collège de France le jeudi 21 mai 2014
No full textInternational audienceL’histoire de l’architecture ne cesse de conjuguer deux regards : celui, panoramique, portant sur les ensembles urbains, révélant les politiques sociales ou techniques, et celui sur les édifices et leurs intérieurs, vus en gros plan, qui reflète les idéaux et l’engagement de leurs auteurs et de leurs habitants.Faisant dialoguer théoriciens, philosophes et écrivains avec les architectes du xxe siècle (Mies van der Rohe, Wright ou Le Corbusier), Jean-Louis Cohen suggère une approche renouvelée, ancrée dans l’histoire culturelle et dans l’humain, de l’architecture comme questionnement et comme pratique
Topological chiral edge states in a synthetic dimension of atomic trap states
No full textInternational audienceA key hallmark of quantum Hall physics is the existence of topological chiral states at the system boundary. Signatures of these edge states have been experimentally observed in cold atoms by using different approaches, including notably that of “synthetic dimensions” in which internal states are coupled together and reinterpreted as sites along an artificial spatial dimension. However, previous atomic synthetic dimension implementations have been limited to relatively small system sizes with inflexible boundaries. In this paper, we propose instead how to use a synthetic dimension of atomic trap states to observe chiral edge states in a large quantum Hall system with a tunable edge. We present numerical simulations for relevant experimental parameters, showing how this scheme may be used to probe the properties and robustness of the edge states to defects. Our work opens the way for future experiments in topological physics with synthetic dimensions, while also providing new ways to manipulate and control highly excited trap states
Fate of chiral order and impurity self-pinning in flat bands with local symmetry
No full textInternational audienceInteracting bosons on a single plaquette threaded by a π flux can spontaneously break time-reversal symmetry, resulting in a chiral loop current. Connecting such bosonic π-flux plaquettes in a dispersive configuration was recently shown to lead to long-range chiral order. Here, instead, we design a chain of π-flux plaquettes that exhibits an all-flat-bands single-particle energy spectrum and an extensive set of local symmetries. Using Elitzur's theorem, we show that these local symmetries prevent the emergence of long-range chiral order. Moreover, projecting the dynamics to a Creutz ladder model with an effective intrarung interaction allows one to derive simple spin Hamiltonians capturing the ground-state degeneracy and the low-energy excitations, and to confirm the absence of chiral order. Nevertheless, we show how to obtain gauge-invariant information from a mean-field approach, which explicitly breaks gauge-invariance. Finally, we observe an impurity self-pinning phenomenon, when an extra boson is added on top of a ground state at integer filling, resulting in a nondispersive density peak. Exact diagonalization benchmarks are also provided, and experimental perspectives are discussed
La fine fleur des héritiers du Maître : les dialogues entre Confucius et ses disciples inscrits sur le miroir exhumé dans la tombe du marquis de Haihun (env. 59 av. n. è.)
No full textInternational audienceLiu He 劉賀 (92-59 av. n. è.), l’un des petits-fils de l’empereur Wu des Han (r. 141-87 av. n. è.), accéda au trône en l’an 74 avant notre ère, puis en fut destitué après 27 jours de règne seulement. Accusé d’impiété, de débauche et de multiples excès d’inconduite, il fut renvoyé dans sa contrée natale de Changyi 昌邑 (province du Shandong). Quelques années plus tard, il fut déchu au rang de marquis (hou 侯) et se vit accorder le lointain fief de Haihun 海昏, près de l’actuelle ville de Nanchang (province du Jiangxi). C’est là que fut découverte en 2011 sa tombe, d’une taille considérable et d’une richesse exceptionnelle. Parmi le matériel funéraire se trouve une pièce en bois laqué, qui servait probablement de miroir sur pied et au dos de laquelle sont peints les portraits de Confucius et de cinq de ses fameux disciples, chaque représentation iconographique étant accompagnée d’une biographie. Ces biographies, qui mêlent narration et dialogues, présentent des analogies avec le chapitre dédié aux disciples de Confucius dans les Mémoires historiques (Shiji 史記) de Sima Qian 司馬遷 (145-86 av. n. è.), mais en diffèrent néanmoins, notamment dans le choix des anecdotes exemplifiant le caractère de chaque personnage et sa relation avec le maître. Nous proposons dans cette communication de comparer les inscriptions figurant sur l’objet exhumé au chapitre de l’historien des Han. Ces écrits quasi contemporains se réfèrent-ils à des sources communes, malgré les contrastes dont ils témoignent ? Quels choix éditoriaux ont pu influencer leur composition ? Comment interpréter les textes inscrits sur le miroir au regard de leur contexte archéologique spécifique et du contexte historique plus général de l’empire chinois du Ier siècle avant notre ère
Le Dieu guerrier du Psautier biblique, Collège de France, 20 février 2025
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