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Assessing spatiotemporal changes in the benthic habitats of the West Gironde Mud Patch through the analyses of surface sediments, benthic macrofauna and sediment profile images
No full textInternational audienceThis work aims to refine the current assessment of spatiotemporal changes in the benthic habitats of the West Gironde Mud Patch. It follows a survey based on the analysis of surface sediment characteristics and benthic macrofauna composition at 5 stations located along a depth gradient, which was achieved between 2010 and 2018. The present work extends this observation period to 2021 and includes the indirect assessment of bioturbation through the analysis of sediment profile image characteristics. Temporal changes in surface sediment characteristics were essentially seasonal with strong increases in chloropigment concentrations in spring. Temporal changes in benthic macrofauna composition were mostly interannual with a major difference between 2010 and 2016-2021 currently attributed to the impact of a major physical disturbance during 2013-2014. In this study, extending the observation period shows that full recovery of benthic macrofauna composition had not yet been achieved by 2021. Sediment profile image characteristics (tube and organisms numbers, area of subsurface structures, oxic void depth and aRPD thickness) showed: (i) clear seasonal changes at the two deepest stations, mostly associated with a spring increase in tube numbers; and (ii) no significant difference between 2010 and 2016-2021, except at the deepest station. The discrepancy between benthic macrofauna composition and sediment profile image characteristics may result from differences in the recovery dynamics of benthic macrofauna composition and functionalities. Overall, results clearly call for a further extension of the WGMP observation period, which could consist in a yearly sampling at only two stations
De la terre de l'origine à la terre promise aux doux en héritage. La mystérieuse destinée de la chair d'Adam dans la pensée de Syméon le Nouveau Théologien
No full textInternational audienceNotre propos voudrait se focaliser sur une question théologique qui n’a peut-être pas suffisamment attiré l’attention dans le domaine de la sotériologie . Il s’agit de la mystérieuse destinée de la terre dont fut tiré notre ancêtre commun, Adam, si l’on admet pour principe l’autorité du récit biblique. Ce dernier, en des lieux forts différents, fera souvent mention de la modeste origine de notre condition corporelle à laquelle viendra pourtant s’ajouter – par fait divin – l’insigne dignité qui échoit spécifiquement à l’homme d’être constitué non seulement d’une terre modelée par le Créateur mais d’un souffle divin. Le thème de la terre est sous-jacent à la question des origines lorsque le récit de la Genèse nous dit qu’au commencement Dieu fit le ciel et la terre , mais il relève également de l’eschatologie en ce que l’Écriture fait mention de la terre nouvelle et des cieux nouveaux dont il faudra ici tenter de comprendre le sens. La terre, silencieuse, la Septante la dit même invisible en son origine , se situe à la base et aux fondements de toute la création . S’il n’est pas trop difficile de convoquer le ciel pour la théologie qui réfléchit au statut des fins dernières, il est beaucoup moins aisé de convoquer la terre. C’est bien elle pourtant qui doit retenir ici notre attention en ce qu’elle est une des clés du salut du monde. En effet, le Verbe, fait d’une chair tirée d’une Vierge, faite comme nous de glaise et de souffle selon Syméon [ἐκ τοῦ αὐτοῦ πηλοῦ καὶ τῆς αὐτῆς πνοῆς] , éleva –par la résurrection– la terre qui le constitua corporellement au rang de ‘lieu’ de notre salut et de lien par lequel Dieu récapitule toute chose en son Fils ainsi que nous tenterons de le présenter ici.Nous avons fait le choix de limiter le périmètre de notre recherche à la pensée de Syméon le Nouveau Théologien, un moine de Constantinople qui vécut au tournant du premier et du second millénaire. L’édition contemporaine, notamment celle de ceux qui le firent connaître en Occident, lui reconnaît à l’évidence des fulgurances aux résonnances bibliques étonnantes, tout en lui déniant, de façon quelque peu anachronique, la rigueur scolastique qu’on eût voulu voir face à la question cruciale de la destinée humaine considérée de façon centrale – quoique de façon non exclusive – sous l’angle de la corporéité, de la chair et de la terre. En bien des points d’exégèse du récit des origines qui concerne la rupture de l’alliance adamique et ses conséquences anthropologiques autant que cosmiques, Syméon fait preuve d’une certaine originalité. Son originalité se veut fidèle pourtant aux Saintes Écritures et à la tradition patristique dont il opère une synthèse tout en la dépassant.Pour conduire notre enquête, nous suivrons, dans l’ordre, les trois volets suivants qui porteront respectivement sur la condition originelle, puis sur les conditions d’existence créées par la rupture de l’alliance adamique, enfin sur l’ère nouvelle inaugurée par l’avènement du nouvel Adam qui réalise en sa chair la vocation et la destinée originelles du corps tiré de la terre autant que celles de toute la création
On the epistemic gain of dispensable applications of mathematics
No full textInternational audienceIf (or when) mathematics is dispensable for solving empirical problems, why can the detour through mathematics be so useful? Typical discussions of applicability only approach this problem indirectly, saying just enough about it to argue that whatever gain mathematics offers (e.g., a gain in inferential power) can be enjoyed without ontological costs. In this paper, I first clarify this problem and distinguish it from other, related ones; in particular, I make it clear that the problem has nothing specifically to do with the application of mathematics to empirical sciences, and arises in the same way for many so-called applications of mathematics to mathematics (which I argue are best defined as deployments of new mathematical resources to make progress on a mathematical problem). I then survey possible solutions, including a particularly promising one, inspired by Ken Manders and in line with recent work on reformulations: mathematics offers tools for systematic expressive restriction, allowing for attentional management in problem-solving
Documents exogènes du monde de l'imprimerie: un contrat notarial (1540)
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JWST imaging of the Pleiades: anisotropy of turbulence in the cold neutral medium
No full textInternational audienceInterstellar medium studies rely on magnetohydrodynamic (MHD) turbulence as a framework for interpretation. In this context, the statistical characterization of interstellar observations is of prime importance. We open a new perspective on diffuse interstellar matter by analyzing James Webb Space Telescope (JWST) observations of the Pleiades nebula with NIRCam. These observations are remarkable in that they provide a microscope view at the cold neutral medium (CNM) with a spatial resolution of 0.2 mpc (40 au). A two-dimensional Fourier analysis is used to characterize the structure of PAH emission in regions near and far from the Pleiades star Merope. To produce maps of the interstellar emission, stars and galaxies are filtered out. The final step in the data cleaning involves subtracting a component, in Fourier space, which we infer to be a residual of the near-infrared cosmic background. The PAH emission power spectra are highly anisotropic. They are well fitted with a break-free power-law, suggesting that we do not observe a specific scale for energy dissipation. Power-law indices are -3.5 near Merope and -3 in the more distant field. The magnetic field orientation, as derived from the Planck dust polarization data, aligns with the PAH anisotropy. The power anisotropy is constant across scales. These findings are discussed in relation to interstellar turbulence that may be driven by the Pleiades stars. The JWST observations of the Pleiades offer a new viewpoint for comparing observations and theoretical models, as they examine physical scales at which turbulence in the CNM is subsonic and decoupled from the thermal instability. The observations may indicate that the turbulent energy cascade in the CNM is anisotropic
Isolation and characterization of 16 new microsatellite loci markers for the European red squirrel (Sciurus vulgaris)
No full textInternational audienceBackground Eurasian red squirrels (Sciurus vulgaris) are common in Europe and Asia, but are declining in many regions across their range. As continental European populations are now facing current and future threats from invasive species in addition to existing anthropogenic pressures it will be important to carefully monitor these populations. Non-invasive genetic sampling methods are a useful tool in conservation assessments, but often require techniques such as microsatellite markers that can be used with lower quality DNA. It remains helpful to increase the resolution of these assessments by identifying additional genetic markers.We describe new microsatellite markers developed from European red squirrels from France and use them to assess genetic diversity in populations in southern France. Methods and ResultsWe used Illumina sequencing to characterize microsatellites from tissue samples of S. vulgaris. Using 7 tissue samples we assessed amplification and polymorphism in 48 microsatellite inserts and further evaluated 16 of these microsatellite loci in hair samples from 120 individuals from four populations. In the 104 samples for which those loci amplified, there was an average of 6.1 alleles amplified per locus, with mean observed and expected heterozygosities of 0.44 and 0.59, respectively. Only one locus showed significant deviation from HWE across all populations.The same locus exhibited a likely presence of null alleles.Conclusions We describe 16 new microsatellite loci, with caution required for one locus in analyses sensitive to null alleles. These new loci can help provide increased resolution in population genetic assessments of red squirrels in continental Europe.</div
Conditional Generative Models for High-Resolution Range Profiles: Capturing Geometry-Driven Trends in a Large-Scale Maritime Dataset
No full textHigh-resolution range profiles (HRRPs) enable fast onboard processing for radar automatic target recognition, but their strong sensitivity to acquisition conditions limits robustness across operational scenarios. Conditional HRRP generation can mitigate this issue, yet prior studies are constrained by small, highly specific datasets. We study HRRP synthesis on a largescale maritime database representative of coastal surveillance variability. Our analysis indicates that the fundamental scenario drivers are geometric: ship dimensions and the desired aspect angle. Conditioning on these variables, we train generative models and show that the synthesized signatures reproduce the expected line-of-sight geometric trend observed in real data. These results highlight the central role of acquisition geometry for robust HRRP generation.</div
Abstract VCG: Tie-breaking rules in VCG mechanism design
No full textInternational audienceWe present computer-checked solutions to the tie-breaking problem in Vickrey-Clarke-Groves (VCG) auctions for Sponsored Search, addressing scenarios involving equal bids. We formally prove that our solution preserves the incentive compatibility property. Both the specification and verification of this theorem are carried out using mech.v, a formal framework for mechanism design built on top of the MathComp library within the Rocq proof assistant. As mech.v and its applications continue to evolve, we aim to contribute not only provably correct algorithms but also reusable tactics for the development of machine-checked proofs in mechanism design
Ambivalent Attitudes towards Amazon in french publishing industry, between Repulsion and Fascination
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Perceptual Advantages of People Living in Semeru Volcanic Areas, Indonesia: An MRCV (Multiple Response Categorical Variable) Analysis
No full textInternational audienceWhy populations persist in active volcanic zones poses a fundamental challenge to risk perception models. We propose that perceptual advantages wherein tangible and intangible benefits filtered through local worldviews underpin this resilience. Through a thematic analysis of an open-ended question/answer study of communities in Mount Semeru, Indonesia, we identify six core frameworks of perceptual advantages. Analysis of Multiple Response Categorical Variable (MRCV) reveals that residents of high-risk zones cognitively amplify bio-cultural and livelihood benefits, showing significantly higher odds of emphasizing BIRTH/FAMILY (lineage/kin ties, birthright, and deep social networks that create an intergenerational connection to the land) and ECONOMIC (livelihood opportunities, including agriculture and volcano-driven tourism) advantages, while safe-zone residents prioritize ambient CLIMATE-related benefits (a preferred quality of life attributed to the region’s cool, fresh air and superior air quality). Crucially, the influence of gender is context-dependent, as significant disparities in perception vanish within the high-risk zone. In this environment, the shared experience of chronic volcanic threat supersedes gender distinction to foster a "community of fate". Within this collective, a shared risk-benefit calculus and a unified identity override individual perspectives. These findings demonstrate that persistence in hazardous environments reflects an active cognitive recalibration of risk and benefit, necessitating disaster policies that integrate these perceptual realities