Scientific Publications of the University of Toulouse II Le Mirail
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What Statistics Don’t See: Human Rights as a Narrative for Global Climate Constitutionalism
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Living on the edge: Pleistocene ice‐free refugia and collared lemming ( Dicrostonyx sp.) in the North American High Arctic
No full textInternational audienceCollared lemmings (genus Dicrostonyx ) are an emblematic group of Arctic‐tundra mammalian communities, comprising six different species in North America. As other northern fauna, most of their diversity is impacted by Pleistocene glacial–interglacial cycles. While D. hudsonius and D. richardsoni have a restricted distribution area on both sides of the Hudson Bay, D. groenlandicus is widespread in all Nearctic northernmost regions, from Alaska and Canadian mainland to the High Arctic Archipelago and Greenland, occupying a highly fragmented area. Using extensive data, this paper investigates the morphological variability of the molar of Nearctic Dicrostonyx using geometric morphometrics. Our results show weak interspecific differences among Nearctic Dicrostonyx , while demonstrating the existence of a clear geographical structure: a north–south gradient that structures collared lemming's phenotype, surpassing interspecific differences. The possible causes of such patterns are explored, whether they are environmental (e.g. due to local to regional climatic conditions) or phylogeographic (e.g. isolation of the populations during the glacial periods) using ERA5‐Land reconstruction climatic data, and a reconstruction of the Laurentide Ice Sheet extent with isometric variations. The peculiar status of several populations, including Greenland and Victoria Island specimens, can be linked with their survival and isolation in Pleistocene ice‐free refugia in the High Arctic in agreement with both genetic and morphological signals. We argue that studying present‐day morphological variability can provide meaningful information on the Quaternary biogeography of modern species
POLYNOMIAL ARGMIN FOR RECOVERY AND APPROXIMATION OF MULTIVARIATE DISCONTINUOUS FUNCTIONS
No full textInternational audienceWe propose to approximate a (possibly discontinuous) multivariate function f (x) on a compact set by the partial minimizer arg miny p(x, y) of an appropriate polynomial p whose construction can be cast in a univariate sum of squares (SOS) framework, resulting in a highly structured convex semidefinite program. In a number of non-trivial cases (e.g. when f is a piecewise polynomial) we prove that the approximation is exact with a low-degree polynomial p. Our approach has three distinguishing features: (i) It is mesh-free and does not require the knowledge of the discontinuity locations. (ii) It is model-free in the sense that we only assume that the function to be approximated is available through samples (point evaluations). (iii) The size of the semidefinite program is independent of the ambient dimension and depends linearly on the number of samples. We also analyze the sample complexity of the approach, proving a generalization error bound in a probabilistic setting. This allows for a comparison with machine learning approaches
« Manager » ses émotions en classe préparatoire littéraire : processus d’individuation de l’enfance à l’âge adulte
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DoubleMe: Local Blending in Multi-Display Environments with Augmented Reality to Facilitate Co-Located Collaboration
No full textInternational audienceCo-located collaboration often raises challenges related to physical constraints because of, e.g., stationary display setups or limited possibilities of movement. We introduce DoubleMe, an Augmented Reality system that generates virtual duplicates of collaborators' workspaces, comprising both their displays and avatars. With DoubleMe, users maintain the layout of their own physical workspace and can position the duplicate of their collaborator's workspace nearby. This approach alleviates spatial constraints by enabling one user to join another's workspace without leaving their own. We report on two experiments examining the effectiveness of this approach. The first experiment investigates how avatar appearance and interaction influence user comfort and relationship dynamics. The second experiment assesses the performance benefits of duplicates over traditional co-located setups for collaborative tasks. Our findings suggest that the addition of duplicates to physical presence can enhance co-located collaboration while improving comfort
La relance d’une extraction minière stratégique dans la mobilisation de guerre : la SOPYFER en 1939-1940
No full textInternational audienceThis article presents a remarkable document—the minutes of the SOPYFER board of directors from 1940—which provides insight into how the company was founded, its objectives, the key figures involved, and some aspects of its operations. SOPYFER was established by the 1938 Wartime National Act to revive the iron mines in the Pyrenees as a strategic necessity in the event of war
Quand la technique sert l‘Empire : la fonderie d’art de Saint-Pétersbourg
No full textLes Minutes d‘histoire de l’architecture moderneEn 1810 paraît à Saint-Pétersbourg un Essai sur les opérations pratiquées lors de la fusion en bronze des statues colossales, d’un seul jet. Publié en édition bilingue, russe et française, l’ouvrage est signé par Piotr Petrovitch Tchekalevski, alors vice-président de l’Académie impériale des beaux-arts de Saint-Pétersbourg. Destiné aux « amateurs des beaux-arts […] qui témoignèrent le désir de connaître les différentes opérations de la fonte », ce traité technique est enrichi de seize planches, dont sept présentent en plan, en coupe et en élévation, la fonderie d’art de la capitale. Tchekalevski y aborde les différentes opérations pour couler les statues colossales et présente la fonderie de l’Académie comme une bâtisse destinée à « faciliter par tous les moyens possibles les progrès de cet art ». Par sa qualité éditoriale et par le choix même de la publication bilingue, ce volume dépasse le simple manuel pratique et se fait le reflet des ambitions d’un empire qui, à la charnière des XVIIIᵉ et XIXᵉ siècles, s’affirme progressivement comme un acteur majeur de la scène européenne, notamment dans le domaine artistique. Dans un contexte de tensions croissantes avec la France napoléonienne, le rôle joué par l’Essai de Tchekalevski et la fonderie d’art dans la valorisation à la fois technique, symbolique et politique des fontes russes, ainsi que dans la mise à distance des étrangers, en particulier des Français, apparaît dès lors déterminant
« Ce qu’il y a de bien avec le changement climatique… »
No full textInternational audienceUn documentaire récent entend brosser une image désirable de la France de 2100 à +4°C pour contrer le pessimisme ambiant. Résultat: une France rance, qui a renoncé à l'atténuation, à la justice sociale et même au bon sens. Une tribune collective rétablit les faits scientifiques sur la dévastation du système Terre et remet la question politique au premier plan
The techno-mediated museum experience for people with visual impairments
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