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An Ancestral Skill. The Decorative Motifs of Sinjali Architecture, West Nepal
No full textInternational audienceThis paper presents a repertoire of fifty-two ornamental motifs used by woodcarvers of Hatsinja, a village located in the Sinja valley of Jumla District (West Nepal). Usually found on religious monuments and, occasionally, in domestic architecture, most of these motifs carry a symbolic meaning, and their origins are locally traced back to the region’s history. This paper intends to present these ornamental motifs according to the information provided by two woodcarvers. They are then be contextualised with contemporary examples of their uses and with the artistic heritage of western Nepal during the medieval period
Les anarcho-syndicalistes allemands et le droit du travail sous la République de Weimar
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Vins, huiles & parfums : voyage archéologique autour de la Méditerranée antique. [Catalogue de l'exposition, Collège de France, 28 octobre 2024 - 31 janvier 2025]
No full textInternational audienceCet ouvrage est le catalogue de l'exposition organisée à l'automne 2024 par le Collège de France, à l'Institut des civilisations, en lien avec la chaire Techniques et économies de la Méditerranée antique du professeur Jean-Pierre Brun, et en collaboration avec l'École française de Rome, le Centre Jean-Bérard de Naples, l'École française d'Athènes, l'Institut français d'archéologie orientale du Caire et le musée du Louvre.Une visite de l'ancienne Méditerranée est proposée, dont le vin, l'huile et le parfum, trois productions antiques sur lesquels Jean-Pierre Brun a travaillé, sont le fil rouge. C'est en effet pour en présenter la fabrication, le transport et le commerce que le lecteur sera conduit de Gaule romaine en Italie, puis en Grèce et en Égypte. L'histoire racontée est aussi celle de la puissance économique de l'Empire romain et l'ouvrage souligne comment ce dernier a pu réunir tant de cultures tout autour de la Méditerranée, dans l'échange pacifique de biens, de technologies et d'idées, qui ont notamment eu des conséquences sur la vie et l'organisation sociale de toutes les populations de l'Empire. Dans ces domaines, la recherche archéologique a largement contribué à renouveler les problématiques
“La pneumatologie lucanienne sur l’arrière-fond des prophéties vétérotestamentaires”,
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Christianizing animals: Physiologus and Hexaemeral Literature
No full textInternational audienceFor a very long time, history was written or narrated as an adventure in which human beings alone was the hero. This created an exclusive, anthropocentric story. According to some re-searchers, this primacy of humans was accentuated in the Christian era because of the place given to humans by Christianity. In this contribution, through a study of the Physiologus and the Hexaemera, I will examine this idea afresh and, ultimately, suggest a different approach to understanding the place given to animals in Byzantine society and their role for Christians in their quest for God
Nonstandard stochastic control with nonlinear Feynman–Kac costs
No full textInternational audienceWe consider the conditional control problem introduced by Lions in his lectures at the Collège de France in November 2016. In his lectures, Lions emphasized some of the major differences with the analysis of classical stochastic optimal control problems, and in so doing, raised the question of the possible differences between the value functions resulting from optimization over the class of Markovian controls as opposed to the general family of open-loop controls. The goal of the paper is to elucidate this quandary and settle Lions’ original conjecture in the case of a relaxed version of the problem. First, we justify the mathematical formulation of the conditional control problem by the description of a practical model from evolutionary biology. Next, we relax the original formulation by the introduction of soft as opposed to hard killing, and using a mimicking argument, we reduce the open-loop optimization problem to an optimization over a specific class of feedback controls. After proving existence of optimal feedback control functions, we prove a superposition principle allowing us to recast the original stochastic control problems as deterministic control problems for dynamical systems of probability Gibbs measures. Next, we characterize the solutions by forward–backward systems of coupled nonlinear and nonlocal partial differential equations (PDEs), very much in the spirit of some of the mean field game (MFG) systems. From there, we identify a common optimizer, proving the conjecture of equality of the value functions. Finally, we illustrate the results with convincing numerical experiments
Affectivity and repetition in Amazonian Ceremonial Welcoming Dialogues
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Induction of intercrypt goblet cells upon bacterial infection: a promising therapeutic target to restore the mucosal barrier
No full textInternational audienceIntestinal mucins play a crucial role in the mucosal barrier, serving as the body’s initial defense against microorganisms. However, how the host regulates the secretion and glycosylation of these mucins in response to bacterial invasion remains unclear. Our study demonstrates that when exposed to Streptococcus gallolyticus (SGG), a gut pathobiont, the host mucosa promptly adjusts the behavior of specialized goblet cells (GCs) located in the middle of the crypts. A subset of these cells undergoes a remodeling, becoming intercrypt goblet cells (icGCs), which do not detach from the surface but instead migrate along intercrypt spaces while secreting a mucus impermeable to bacterial pathogens. Significantly, a non-piliated SGG mutant unable to bind to mucus fails to induce icGCs, allowing its translocation through the mucosa and submucosa. Interestingly, a closely related nonpathogenic bacterium, SGM, able to bind to mucus, also triggers the differentiation of GCs into icGCs. This discovery opens new avenues for treating patients with a “leaky gut” as observed in intestinal diseases such as inflammatory bowel diseases and metabolic disorders, but also patients with a history of repeated antibiotic use. Utilizing mucus-adherent probiotics to induce icGCs represents a promising strategy for reinforcing the mucosal barrier
Communication entre l'hippocampe, l'aire tegmentale ventrale et le noyau accumbens pendant l'apprentissage et la consolidation de la mémoired Memory Consolidation
No full textThe hippocampus as been associated to episodic memory, and particularly in the spatial component of memories. Indeed, place cells, neurons that fire in specific locations of the animal in the environment, called their 'place field', have been discovered in the hippocampus. As an animal run through a trajectory, different place cells fire one after the other, representing the position of the animal as he mooves in his environment. During moment of immobility, and during sleep, specific oscillations, called 'ripples' can be detected in the hippocampus. When looking at the activity of place cells during these ripples, sequences of place cells can be detected in an order consistent with the trajectories of the animal. These 'replay' have been postulated to play a role in memory consolidation and decision making. However, the way these spatial representation take into account other components of memory remain unknown. In particular how reward information, related to positive stimuli, is integrated together with spatial information coding by the hippocampus is not clear. The ventral tegmental area (VTA) has been link to reward processing, in particular through its dopaminergic neurons, that encore for the expected value of reward. Together with the nucleus accumbens, that receive massive projection from the VTA, they have been thought to encode for reward information in order to guide behavior.We postulated that hippocampus, VTA and nucleus accumbens are coordinated during learning and memory consolidation, in particular during hippocampal replay. To test our hypothesis, we developed a new behavioral task, the Hippodamos task, in which animals learn complex spatial trajectory associated to reward components, and allowed us to probe for memory consolidation during sleep after initial learning. We recorded electrophysiological signal and isolated dozens of units in the hippocampus, VTA and nucleus accumbens simultaneously, while animal performed the Hippodamos task. Analysing the activity of these neurons, we find that VTA cells are coordinated during awake and sleep ripples, which could be a mechanism in which spatial and reward information are linked during learning and memory consolidation. Furthemore, we find that ripples are specific moment of reactivation of task patterns during sleep. We detect these reactivations during hippocampus, which has been shown previously, but also in VTA and nucleus accumbens. We also find that ripples are also unique windows of cross-structural reactivations, be it hippocampus-VTA, hippocampus-nucleus accumbens, or VTA-nucleus accumbens reactivations. These findings support our hypothese that ripples are windows that allow for cross-structural coordination and unravell a possible mechanism for spatial and reward association.L'hippocampe est associé à la mémoire épisodique, et en particulier à la composante spatiale des souvenirs. En effet, les "cellules de lieux", des neurones qui déchargent uniquement dans certains endroits de l'environnement, appelé leur "champ de lieux", ont été découverte dans l'hippocampe. Quand un animal se déplace dans un environnement, différentes cellules de lieux vont être activées successivement, permettant la représentation de la position de l'animal alors pendant son déplacement. Pendant des moments d'immobilité, et lorsque l'animal dort, des oscillations spécifiques appelé "ondulations" peuvent être détectée dans l'hippocampe. Pendant ces oscillations, les cellules de lieux s'activent dans un ordre similaire aux séquences détecté pendant l'exploration. Ces "rejeux" ont été proposé comme un mécanisme facilitant la consolidation de la mémoire, ainsi que la prise de décision. Cependant, la manière dont des informations autres que l'espace sont intégrées avec l'information spatiale reste inconnus. En particulier, l'intégration de la composante récompensante de certains stimuli n'est pas encore expliquée. L'air tegmental ventrale (ATV) est une structure qui a été lié à l'intégration de la récompense, en particulier les neurones dopaminergic. Le noyaux accumbens, l'une des structures recevant le plus de projections de l'ATV, et l'ATV sont conceptualisés comme des structures permettant l'intégration d'information récompensante. Pour ce projet, nous avons postulé que l'hippocampe, l'ATV et le noyaux accumbens sont coordonné pendant l'apprentissage et la consolidation de la mémoire, en particulier pendant les rejeux hippocampiques. Pour tester notre hypothèse, nous avons développé une nouvelle tache comportementale, la tache Hippodamos, dans laquelle des animaux apprennent des trajectoires spatiales complexes associées à des éléments de récompense, nous permettant d'étudier la consolidation de la mémoire pendant le sommeil après l'apprentissage initial. Nous avons enregistré des signaux électrophysiologiques et isolé des dizaines d'unités dans l'hippocampe, l'ATV et le noyau accumbens simultanément, pendant que l'animal effectuait la tâche Hippodamos. En analysant l'activité de ces neurones, nous constatons que les cellules de l'ATV sont coordonnées pendant les ondulations de l'éveil et du sommeil, ce qui pourrait être un mécanisme dans lequel les informations spatiales et de récompense sont liées pendant l'apprentissage et la consolidation de la mémoire. En outre, nous constatons que les ondulations sont des moments spécifiques de réactivation d'éléments de la tâches pendant le sommeil. Nous détectons ces réactivations dans l'hippocampe, ce qui a été démontré précédemment, mais aussi dans l'ATV et le noyau accumbens. Nous constatons également que les ondulations sont des fenêtres uniques de réactivations interstructurelles, qu'il s'agisse de réactivations hippocampe-ATV, hippocampe-noyau accumbens ou ATV-noyau accumbens. Ces résultats confirment notre hypothèse selon laquelle les ondulations sont des fenêtres qui permettent une coordination interstructurelle et dévoilent un mécanisme possible d'association spatiale et de récompense