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Archaeological and rock art evidence of the horse in the prehistoric western Himalayas and the Tibetan plateau
No full textInternational audienc
Fast recovery of parametric eigenvalues depending on several parameters and location of high order exceptional points
No full textInternational audienceA numerical algorithm is proposed to deal with parametric eigenvalue problems involving non-Hermitian matrices and is exploited to find location of defective eigenvalues in the parameter space of non-Hermitian parametric eigenvalue problems.These non-Hermitian degeneracies also called exceptional points (EP) have raised considerable attention in the scientific community as these can have a great impact in a variety of physical problems. The method first requires the computation of high order derivatives of a few selected eigenvalues with respect to each parameter involved. The second step is to recombine these quantities to form new coefficients associated with a partial characteristic polynomial (PCP). By construction, these coefficients are regular functions in a large domain of the parameter space which means that the PCP allows one to recover the selected eigenvalues as well as the localization of high order EPs by simply using standard root-finding algorithms.The versatility of the proposed approach is tested on several applications, from mass-spring systems to guided acoustic waves with absorbing walls and room acoustics. The scalability of the method to large sparse matrices arising from conventional discretization techniques such as the finite element method is demonstrated.The proposed approach can be extended to a large number of applications where EPs play an important role in quantum mechanics, optics and photonics or in mechanical engineering
Professionnels des transformations pédagogiques dans l'enseignement supérieur : contexte, enjeux, perspectives
No full textInternational audienc
Modeling and Parameter Estimation of Tumor Spheroids from Bottom-View Imaging: Beyond the Spherical Assumption
No full textTumor spheroids are widely used in vitro models for studying tumor growth and treatment response, yet their analysis is often limited by incomplete geometric measurements. In practice, only a two-dimensional bottom view is available, which can lead to strong biases when spheroids deviate from an ideal spherical shape, in particular for flattened aggregates. We propose a mechanistic modeling and data assimilation framework that accounts for both poor data quality and model uncertainty. A biologically motivated partial differential equations model with axial symmetry is introduced and reduced to a low-dimensional system compatible with sparse observations and ellipsoidal shapes. Uncertainties in initial conditions and parameters are handled using a Luenberger-type observer coupled with a reduced-order unscented Kalman filter. The approach is validated on synthetic data and applied to experimental in vitro spheroid data under propranolol treatment, illustrating how model-based integration of limited measurements improves the interpretation of spheroid growth dynamics and treatment-induced morphological changes
Incursions upon agricultural land within metropolitan peripheries: Deadlocks and geo-legal trajectories of regularization in Paris and Mexico-city
No full textInternational audienceWithin metropolitan peripheries, irrespective of the national or regional contexts, the clash between rural and urban areas is at the center of metropolitan production. This clash is a twofold movement with urban sprawl, on the one hand, and major environmental injunctions, on the other. By looking at the two contexts of Paris and Mexico City, our research objective is to comprehend peripheries as places magnifying competing land dynamics, leading to scenarios of crises as well as social, political and legal innovations. The methodology is based on the analysis of field observations and surveys, public databases and official documents, using a social geographical approach. The article analyzes how stakeholders within the land system control peripheral land, focusing on public authorities, property market actors, and developers. The goal is to show the limitations of this control and reveal how and why residents and citizen groups build arrangements and regularizations. At the end, this article aims to contribute to the debates on the land rules deadlocks in the urban-rural interface. From different deadlocks observed in each context, the comparison underlines converging geo-legal trajectories of land regulation
Mosaïques et peintures de Délos : évolution des approches, des outils et des méthodes d’étude
No full textInternational audienc
Communiquer avec l’invisible dans la tombe. Mises en scène pour l’au-delà
No full textInternational audienceLa subtilité des liens qu’entretient un groupe humain avec le sacré ou l’invisible (dieux, ancêtres et autres entités supranaturelles) est souvent difficile à saisir pour l’observateur de sociétés actuelles. Elle l’est plus encore pour l’archéologue, surtout s’il s’intéresse à des sociétés anciennes sans récit ni monument ou édifice en lien avec une forme de religion clairement identifiable. Comment tenter, dans un tel contexte, d’appréhender les croyances d’une population, de caractériser son rapport à ce qui dépasse l’humain ? Comment reconnaître un objet rituel ou un talisman, le distinguer d’un objet ou d’un dépôt ordinaire, en proposer une interprétation ? Les seules traces disponibles sont bien souvent des tombeaux, portes ouvertes sur l’au-delà. Des ensembles funéraires de l’âge du Bronze, vieux de plus de 3500 ans, au Xinjiang en Chine du Nord-Ouest constituent des témoignages de nature à éclairer la complexité de cette question et les mécanismes à mettre en œuvre pour tenter d’y répondre, au moins partiellement
How generics obscure the logic of conditionals
No full textInternational audienceThis paper discusses counter‐examples to modus ponens and modus tollens involving modals and quantificational adverbs, and presents new counter‐examples with generic conditionals. We argue that the counter‐examples are spurious, and are explained by the domain‐restricting effects of if ‐clauses. Generic conditionals are especially problematic because the generic operator is silent and detectable only through its interpretive effects. A second, experimental case study involving nested conditionals illustrates the ease with which generic conditionals can mislead theorists about the logic of conditionals. To avoid pitfalls, theorists choosing examples and designing experimental materials must pay close attention to the special linguistic properties of generics
Beyond Locality: Proparoxytone Metaphony and Morphophonological Domains in Romance
No full textInternational audienc
Is non-local communication really impossible?
No full textThis paper shows the possibility of non-local communication between two entangled, spacelike separated sub-systems. More specifically, it is shown that if there exist (at least) two non-commuting observables respectively defined on these two sub-systems then, for some entangled state of the global system, the probability distribution of the outcomes of measurements performed in one of its parts is changed by the actions that have been performed in the other one. This causal dependency, which includes that of the settings, makes possible a nonlocal exchange of information between the parties