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Ma "Voix-Monde": Multimodalité et plurilinguisme dans un projet d'écriture créative avec l'oeuvre dramatique Tous des Oiseaux de Wajdi Mouawad.
No full textInternational audienc
Mathematical modeling of the feather follicle morphogenetic wave in birds
No full textInternational audienceDuring the development of the avian skin, feather follicles are produced in a medio-lateral morphogenetic wave that results in their spatial arrangement in typical patterns. This wave involves the timely acquisition of pattern-forming competence followed by a row-by-row produc tion of feather follicles. While several mathematical models combining self-organizing systems accurately reproduced dynamics of feather follicle pattern formation, the events that control timely parameters of wave propagation remain poorly understood. Here, we built on previous modeling work to theoretically calculate the speed at which tissue competence progresses. Using a weakly non-linear analysis, we calculated the speed at which follicles emerge once competence is attained. We produced numerical simulations of our model to predict the respective influences of competence acquisition and follicle emergence on each other and on wave propagation. Our results show that the theoretical speed of follicle emergence is limited by competence acquisition, but that, in turn, competence acquisition is not constrained by follicle emergence. This modeling work provides an approximation of the timely parameters of the morphogenetic wave, and sheds light on the interplay between competence and patterning events in the developing skin
Women and the Roman army. Onomastics and romanization
No full textInternational audienceIn the vast subregion situated to the East of Roman Syria, from Palmyra to the banks of the Euphrates, several cities have left a rich documentation. In Zeugma, Hierapolis, or Dura Europos, Greek (mostly) inscriptions and archaeological remains give insights on the rise and fall of these cities. Building on previous studies of the onomastics of the region and on comparisons with neighbouring cities, this contribution will deal with the impact of the Roman military on the local population, and more specifically on the onomastics of women. Based on more particular and local features, in funerary sculptures, in dress, in language, it will aim to differentiate between the development patterns of the various cities concerned and their rural environment, and to lead to new conclusions on the regional culture. Investigation on the differences between the reliefs of Zeugma and of Hierapolis, although typologically similar, will be an opportunity to reflect on the history of each city
PERI‐URBAN EXTRACTIVISM: The Political Economy of ‘Cheap Sprawl’
No full textInternational audienceThis article explores peri-urbanisation through the lens of extractivism from a criticalpolitical-economic perspective. Our analytical framework sheds new light on peri-urbanisation. We examine the uneven nature of the process, unpack its growth engine andhighlight its shortcomings. By shifting the focus from the demand to the supply of peri-urbanhousing, our approach overcomes the limitations of a traditional analysis based on land rent.Peri-urbanisation is thus considered in the light of resource exploitation (namely land), by acoalition of public and private stakeholders, whose methods include accumulation bydispossession. Land and modest homebuyers are the resources exploited by the coalition toextract solid value. Simultaneously, sprawl is the engine that provides a continuous supply ofcheap land to sustain the process. However, when this coalition captures value from theurbanisation of agricultural land (and the creditworthiness of precarious homebuyers), theresulting irreparable soil artificialisation impedes future redevelopments. By drawing on twocase studies of this type of “cheap sprawl” and by bridging the traditional North-South divide,this article provides empirical evidence to show that peri-urban extractivism is just that: apredatory system. Not only does it keep peripheral areas in a state of “non-development”, italso has a serious toll on the environment
A comprehensive separation of dark matter and baryonic mass components in galaxy clusters II: an overview of the mass distribution in Abell S1063
No full textInternational audienceIn the first paper of this series, we derived mass constraints on the total mass and the baryonic components of the galaxy cluster Abell S1063. The main focus was to recover stellar masses and kinematics for cluster members, the brightest cluster galaxy (BCG) and the intra-cluster light (ICL). In this second paper, we introduce a multi-probe mass modelling approach that incorporates constraints on both the total mass and the individual baryonic components. We obtain comprehensive mass models of Abell S1063, in which the dark matter distribution is disentangled from the baryonic mass at both cluster and galaxy scales. The best-fitting mass model achieves an RMS of on the multiple image positions. The kinematic profiles of the BCG & ICL, as well as the X-ray surface brightness of the intra-cluster gas, are accurately reproduced within observational uncertainties. However, a scatter is required for the cluster member line-of-sight dispersions. This method yields the most complex parametric mass model with consistency among almost all available mass constraints. We find a agreement between the inferred stellar-to-subhalo mass relation and that predicted by large-scale cosmological simulations. The ICL stellar mass derived from our model is consistent with estimates from stellar population modelling. We present the first multi-probe mass modelling method capable of disentangling the dark matter from the baryonic mass distributions in massive galaxy clusters. Its results, such as the stellar-to-subhalo mass relation or the distribution of each mass component, can be directly compared to hydrodynamical cosmological simulations such as illustrisTNG
Computational aspects of the trace norm contraction coefficient
No full textWe show that approximating the trace norm contraction coefficient of a quantum channel within a constant factor is NP-hard. Equivalently, this shows that determining the optimal success probability for encoding a bit in a quantum system undergoing noise is NP-hard. This contrasts with the classical analogue of this problem that can clearly be solved efficiently. We also establish the NP-hardness of deciding if the contraction coefficient is equal to 1, i.e., the channel can perfectly preserve a bit. As a consequence, deciding if a non-commutative graph has an independence number of at least 2 is NPhard. In addition, we establish a converging hierarchy of semidefinite programming upper bounds on the contraction coefficient
Restitution du fractionnement des méso-habitats des rivières intermittentes par imagerie drone : le cas de l’Albarine.
No full textThe morpho-ecological structuring of rivers is one of the key factors governing the distribution of habitats and, implicitly, the quality of fluvial aquatic environments. The presence of endemic faunal and floral species embedded within a diversity of riverine features—such as riparian vegetation, the main channel, and floodplain water bodies—makes this complex system a highly sensitive environment.In the context of global climate change, certain reaches of perennial rivers will increasingly be affected by phenomena of partial or complete channel desiccation. Intermittent rivers are therefore expected to become more frequent, even in areas that have historically been characterized by permanent flows.Such drying events have significant consequences, both for aquatic communities and riparian vegetation, as well as for the overall equilibrium of hydrosystems. The need for operational tools is therefore paramount to study these habitats, their distribution, and their monitoring in order to assess their ecological quality. This evolution raises new scientific and management challenges, particularly with regard to ecological connectivity, water quality, and groundwater recharge (Fovet et al., 2021).Recent research on the spatio-temporal dynamics of rivers, and in particular on their impacts on fish habitats and macroinvertebrate communities, offers new perspectives for understanding the links between the physical characteristics of rivers and the stability of metacommunities (Datry et al., 2017a).It is within this framework that the RIVERSIDE project (Restitution of mesohabitat fragmentation in Intermittent RiVERS through Drone Imagery: the case of the Albarine) has been developed. This study builds on recent advances in drones and embedded sensors to survey the Albarine River channel. Very high-resolution imagery and drone-acquired LiDAR data, combined with spatial analysis and hydraulic modelling, now make it possible to explore with great precision the relationships between the hydromorphology of intermittent rivers and the distribution of fish refugia. The integration of drone-based data with fish inventory surveys enables the analysis of relationships among aquatic habitats, channel morphology, and riparian vegetation.La structuration morpho-écologique des cours d’eau est un des facteurs clefs de la répartition des habitats et implicitement de la qualité des milieux aquatiques fluviaux. La présence d’espèces faunistiques et floristiques endémiques à ces milieux imbriquées dans une variété de faciès rivulaires tels qu’une végétation riparienne, un chenal, des annexes fluviales font de ce système complexe un milieu sensible. Dans un contexte de réchauffement climatique global, certaines portions des cours d’eau pérennes vont être de plus en plus concernées par des phénomènes d’assèchement partiel ou intégral de leur lit. Les rivières intermittentes sont donc appelées à devenir plus fréquentes, y compris dans les zones jusqu’alors caractérisées par des écoulements pérennes.Ces assèchements provoquent des conséquences importantes à la fois sur les communautés aquatiques, sur la végétation rivulaire et sur l’équilibre globale des hydrosystèmes. Le besoin d’outils opérationnels est donc primordial pour étudier ces habitats, leurs répartitions et leurs suivis afin d’évaluer leur qualité. Cette évolution soulève de nouveaux défis scientifiques et de gestion, notamment en matière de continuité écologique, de qualité de l’eau, et de recharge des nappes (Fovet et al., 2021). Les travaux récents sur les dynamiques spatio-temporelles des cours d’eau, et enparticulier sur leurs impacts sur les habitats piscicoles et les communautés de macroinvertébrés, ouvrent aujourd’hui de nouvelles perspectives pour comprendre les liens entre les caractéristiques physiques des rivières et la stabilité des métacommunautés (Datry et al., 2017a).C’est dans ce contexte que s’inscrit le projet RIVERSIDE (Restitution du fractionnement des mésohabitats des rIVières intERmittenteS par Imagerie DronE : le cas de l’Albarine).Cette étude s’appuie sur les avancées récentes en matière de drones et de capteurs embarqués pour survoler le chenal de l’Albarine. L’imagerie à très haute résolution et les données LiDAR acquises par drones, associées à l’analyse spatiale et à des modèles hydrauliques, permettent désormais d’explorer avec une grande précision les liens entre l’hydromorphologie des cours d’eau intermittents et la distribution des refugespiscicoles. La combinaison des données issues des drones avec des relevés d’inventaire piscicole permet d’analyser les relations entre les habitats aquatiques, la morphologie du chenal et la végétation riparienne
Enquête philosophique sur le concept de délégation aux dispositifs numériques
No full textThe proliferation of digital technologies has been accompanied by a diversification of software, which is no longer regarded as mere technical objects (in Simondon’s sense) but as genuine digital dispositifs structuring interactions between humans and non-humans. In this context, the concept of delegation—the act of "having something done"—becomes central to understanding these dispositifs.Delegation through digital technologies transforms the relationship between producers (algorithm developers) and users by assigning the former a scribe-like role, redefining the frameworks of interaction. This delegation is not merely a matter of imaginary (Latour) or physical substitution of humans by machines; it should be analyzed as an "indeterminate situation" (Dewey), shedding light on the technical originality of these new operational forms.Traditionally conceived within a political or administrative framework, delegation relies on a clear distinction between the delegator and the delegate, with the latter possessing a certain degree of autonomy (Bourdieu). However, in the case of digital dispositifs, delegation also mobilizes epistemological fictions that shape our experience and modes of knowledge (Vaihinger). This generates new forms of organization and algorithmic governmentality (Rouvroy & Berns), challenging the concept of the technological system (Ellul).The study identifies four traditional forms of delegation: political, administrative, managerial, and industrial. These forms make it possible to assess the delegate’s autonomy based on the resources provided, the assigned objectives, and the granted margins of freedom. This approach thus highlights the limits and specificities of each type of delegation according to the context in which it operates.The second part investigates the various stages involved in the implementation of delegation to digital dispositifs. This section explores the role of the component industry in the emergence of digital delegation and the influence of algorithmic writing on technical dispositifs. Digital technologies introduce a dynamic interplay of feedback loops and behavioral measurements, altering users’ experiences. We emphasize the central role of the component industry, which defines the technical and material conditions that make delegation possible. We then analyze how algorithmic writing shapes the individuation of dispositifs and the schemas of intelligibility through these new technologies of the intellect (Goody). Through the examination of four emblematic examples—Uber, Parcoursup, legal decision-support software, and LATEX—we map out the multiple delegative transfers to digital dispositifs, illustrating the relationships they establish with both scribes and users, as well as the values they embed and embody.The final part revisits the concept of technical delegation, taking into account the materiality of digital dispositifs. By reframing delegation in terms of material, scribal, and relational structures, this analysis opens avenues for rethinking the critique of technology (Feenberg) and exploring how users can reinterpret and appropriate these technologies to shape both their trajectory and the values underlying them.Ultimately, this reflection highlights the transformative power of digital delegation, underscoring the importance of moving beyond a perspective centered solely on control to envision a more democratic appropriation of technology.La prolifération des technologies numériques s’accompagne d’une diversification des logiciels, qui ne sont plus considérés comme de simples objets techniques (au sens de Simondon) mais comme de véritables dispositifs numériques structurant les interactions entre humains et non-humains. Dans ce cadre, le concept de délégation – l’acte de « faire faire » – devient central pour comprendre ces dispositifs. La délégation par les technologies numériques transforme la relation entre producteurs (développeurs d’algorithmes) et utilisateurs, en conférant aux premiers un rôle de scribes qui redéfinissent les cadres d’interaction. Cette délégation ne se réduit pas à une simple substitution imaginaire (Latour) ou physique de l’humain par la machine, mais doit être analysée comme une situation indéterminée (Dewey), mettant en lumière l’originalité technique de ces nouvelles formes opératoires. Traditionnellement pensée dans un cadre politique ou administratif, la délégation repose sur une distinction nette entre le déléguant et le délégué, ce dernier disposant d’une autonomie d’action (Bourdieu). Or, dans le cas des dispositifs numériques, la délégation mobilise également des fictions épistémologiques qui influencent notre expérience et nos modes de connaissance (Vaihinger). Cela génère de nouvelles formes d’organisation et de gouvernementalité algorithmique (Rouvroy & Berns) qui réinterrogent le concept de système technicien (Ellul).L’étude identifie quatre formes traditionnelles de délégation : politique, administrative, managériale et industrielle. Ces formes permettent d’évaluer l’autonomie du délégué selon les ressources mises à sa disposition, les objectifs qui lui sont assignés et les marges de liberté qui lui sont accordées. Cette approche met ainsi en lumière les limites et les spécificités de chaque type de délégation en fonction du contexte dans lequel elle s’exerce. La seconde partie enquête sur les différentes étapes de la mise en place des délégations aux dispositifs numériques. Cette partie explore le rôle de l’industrie des composants dans l’émergence de la délégation numérique et l’influence de l’écriture algorithmique sur les dispositifs techniques. Les technologies numériques introduisent un jeu de rétroactions et de mesures comportementales modifiant l’expérience des utilisateurs. Nous rappelons le rôle central de l’industrie des composants, qui profile les conditions de possibilité techniques et matérielles de la délégation. Nous analysons ensuite la façon dont l’écriture algorithmique façonne l’individuation des dispositifs et les schèmes d’intelligibilité à travers ces nouvelles technologies de l’intellect (Goody). À travers l’analyse de quatre exemples emblématiques – Uber, Parcoursup, les logiciels d’aide à la décision juridique et LATEX – l'examen des multiples transferts délégatifs aux dispositifs cartographient des rapports aux mondes et des valeurs qui sont intégrées par les dispositifs à travers ses relations avec les scribes et les utilisateurs. La dernière partie revisite les concepts de délégation technique en prenant en compte la matérialité des dispositifs. En reformulant la délégation sous l’angle des structures matérielles, scribales et relationnelles, cette analyse ouvre des pistes pour repenser la critique des techniques (Feenberg) et explorer comment les utilisateurs peuvent réinterpréter et s’approprier ces technologies pour influencer leur trajectoire et les valeurs qui les structurent. En définitive, cette réflexion met en lumière le pouvoir transformateur de la délégation numérique, soulignant l’importance de dépasser une vision strictement centrée sur le contrôle, pour envisager une appropriation plus démocratique des technologies
«Des tresces» e «Berenger au lonc cul»: due fonti per la novella VII 8 del «Decameron»?
No full textInternational audienceThis study aims at finding the sources that inspired tale VII, 8 of the Decameron, that is to say two fabliaux by Garin: Des tresces and Berengier au lonc cul. The main focus of this paper is to understand how and why Boccaccio rewrote and adapted the two Old French short stories to his own poetics and audience. As a matter of fact, Des tresces was employed as the narrative core of Boccaccio’s tale, whereas Berengier au lonc cul provided the fundamental theme that was added to the main theme of Day VII.Questo studio propone di rintracciare le fonti alla base della novella VII 8 del Decameron, riscontrabili in due fabliaux di Garin, Des tresces e Berengier au lonc cul. L’interesse è di analizzare come e perché Boccaccio rielabora e rilegge i due racconti oitanici, adattandoli alla sua poetica e al pubblico del suo tempo: se da un lato, infatti, Des tresces fornisce alla novella il nucleo narrativo di base, dall’altro Berengier au lonc cul offre il tema fondante, che si interseca e in parte si sovrappone a quello della giornata
A causal random synthetic turbulent velocity field: I. The underlying Gaussian structure
No full textWe develop, simulate and extend an initial proposition by Chaves et al. concerning a random incompressible vector field able to reproduce key ingredients of three-dimensional turbulence in both space and time. In this first article, we focus on the important underlying Gaussian structure that will be generalized in a second article to account for higher-order statistics. Presently, the statistical spatial structure of this velocity field is consistent with a divergence-free fractional Gaussian vector field that encodes all known properties of homogeneous and isotropic fluid turbulence at a given finite Reynolds number, up to second-order statistics. The temporal structure of the velocity field is introduced through a stochastic evolution of the respective Fourier modes. In the simplest picture, Fourier modes evolve according to an Ornstein-Uhlenbeck process, where the characteristic time scale depends on the wave-vector amplitude. For consistency with direct numerical simulations (DNSs) of the Navier-Stokes equations, this time scale is inversely proportional to the wave vector amplitude. As a consequence, the characteristic velocity that governs the eddies is independent of their size and is related to the velocity standard deviation, which is consistent with some features of the so-called sweeping effect. To ensure differentiability in time while respecting the causal nature of the evolution, we use the methodology developed by Viggiano et al. to propose a fully consistent stochastic picture, predicting in particular proper temporal covariance of the Fourier modes. We finally derive analytically all statistical quantities in a continuous setup and develop precise and efficient numerical schemes of the corresponding periodic framework. Both exact predictions and numerical estimations of the model are compared to DNSs provided by the Johns Hopkins database