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6 hybridations qui redéfinissent l'entreprise
No full textNational audienceCertaines entreprises ne se contentent plus d’innover : elles combinent des logiques longtemps perçues comme incompatibles - expertise industrielle et performance sportive, gouvernance territoriale et compétitivité, culture d’entreprise et engagement social, écologie régénérative et modèle industriel, retail physique et économie circulaire, métiers historiques et services de proximité. Dans ces hybridations, des mondes qui s’ignoraient fusionnent pour créer de nouvelles formes de valeur, économiques, sociales ou écologiques.Pour Lionel Garreau, maître de conférences à Paris Dauphine – PSL, ces hybridations ne sont pas des parenthèses mais les signes tangibles d’un changement profond : une transformation qui réécrit les modèles d’entreprise de l’intérieur
Leçon des ténèbres. Des évolutions/révolutions du roman germanien
No full textAutre titre : Leçons des ténèbres. (R)évolutions du roman germanier.International audienc
Space oddity: How context matters in waste-sorting behavior
No full textInternational audienceThe circular economy gives a prominent role to recycling, entailing the general implementation of waste sorting in private, semi-public, and public locations. Previous literature has extensively explored the psychological and contextual antecedents of waste-sorting behavior, but mainly with a focus on one specific setting, without considering how the sorting location might moderate the influence of these antecedents. To investigate this research question, we develop a dual-route model of waste-sorting behavior based on an integrated TPB-NAM framework. To test this model, we used a survey based on self-reported data considering three successive locations (i.e., home, university and on the way to university) from the same 296 French college students and analyzed it using structural equation modeling with partial least squares (PLS-SEM). Although both psychological and contextual routes influence waste sorting, we show that their relative importance differs across locations. Furthermore, at university and on the way to university, the contextual route influences the psychological one. These results highlight why individuals' self-reported waste-sorting behavior may vary across locations and call on academics to replicate pro-environmental behavior models across all relevant contexts before recommending public policies to promote them
BrGDGT-based palaeothermometer in drylands: the necessity to constrain aridity and salinity as confounding factors to ensure the robustness of calibrations
No full textInternational audiencePast temperature reconstructions offer valuable insights into the impact of climate change on the global climate-human-vegetation system. Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are recognized as effective temperature proxies, particularly in lakes and peatlands, where they are well preserved. However, their reliability as palaeothermometers can be compromised by factors beyond air temperature, especially in drylands. This study investigates the recently compiled Arid Central Asian (ACA) brGDGT surface Data Base, a regional dataset consisting of 753 surface samples from the drylands of ACA. The distribution of brGDGTs in relation to climate and environmental variables was analysed to explore their potential as reliable temperature proxies, mainly focusing on brGDGTs methylation (MBT), cyclisation (CBT), and isomer (IR) indices. The brGDGT-based palaeothermometer is a promising tool for understanding past climates, but our comparison between an ACA-centred database and a worldwide continental surface sample database reveals several challenges. Drylands exhibit extreme climate and soil/lacustrine properties, amplifying the impact of confounding factors on brGDGT-based relationships with mean annual air temperature. Salinity emerges as the dominant factor influencing brGDGT variance, followed by sample type, pH, and aridity, all of which contribute significantly. These factors interact in complex ways, with the salinity effect varying between soil and lacustrine deposits. For sample physicochemical conditions, the IR6+7Me′ index is best for salinity, and IR6Me is most suitable for pH reconstruction. Thus, the MBT5Me′-temperature relationship is limited in ACA, particularly for lacustrine samples, and MBT6Me′ does not offer a better solution under hyper- to semi-arid conditions. Sub-calibrating models for specific environmental conditions such as salinity and aridity improves the accuracy of temperature reconstructions. Furthermore, the difference between MBT5Me′ and MBT6Me′ provides a promising proxy to assess aridity. Although the brGDGT signal in drylands is influenced by multiple controlling factors, it remains a valuable tool for understanding past climate and environmental conditions, especially when accounting for the complex interactions between these factors based on each study's unique physicochemical and bioclimatic context. Further research, incorporating a broader range of surface samples alongside comprehensive soil and climate data, holds the potential to enhance the accuracy of brGDGT-based climate reconstructions
Early Justifications of Indigenous and African Slavery in Colonial Latin America
No full textInternational audienceThis chapter inquires international law’s engagement with regard to Indigenous and African slavery in the Americas throughout the 16th century. First, it recalls that the initial set of laws governing slavery and forced labor in the Iberian American colonies drew from existing European medieval rules and institutions. Second, it explores the early debates that took place with regard to the morality and/or legality of exploitative practices targeting Indigenous Peoples and sub-Saharan Africans. The latter were considered human beings who, although barbarians, were endowed with reason and natural freedom, the loss of which could only be the consequence of human institutions and forms of interaction introduced by the law of nations (ius gentium), such as commerce and war. The chapter examines how these ideas and arguments were articulated together in order to subjugate native peoples in the Americas and in Angola, the region mostly affected by the transatlantic slave trade in the 17th century
Y a-t-il « guerre juste » ou « génocide » à Gaza ? Quelques réflexions sur les rapports entre morale et droit international
No full textInternational audienc
Riemannian adversarial attacks on Symmetric Positive Definite matrices
No full textInternational audienceIn this paper, we study adversarial vulnerabilities when inputs lie on the manifold of symmetric positive definite (SPD) matrices by proposing a Riemannian Projected Gradient Descent (R-PGD) attack. This attack performs updates along the affine-invariant geometry and projects using a geodesic budget. We also give a reconstruction procedure that maps adversarial SPD matrices back to the original signals while enforcing spectral constraints. On Brain Computer Interface datasets and SPDNet, R-PGD is more effective than Euclidean PGD and yields geometrically tailored perturbations that remain adversarial after pre-processing. Our results motivate robustness analyses and defenses for manifold deep models
Multi-epoch VLBI observations of the blazar 3C 66A: Spatial twisting and temporal oscillation of the parsec-scale jet
No full textInternational audiencePrevious VLBI kinematic studies of the blazar 3C 66A have unveiled complex jet kinematic behaviors. Using follow-up high-resolution VLBI observations and archival data, we investigate the morphology and the variations in orientation and core flux density of the 3C 66A jet to gain a deeper insights into its kinematic behavior and physical origins. We performed KVN and VERA array (KaVA) observations at 22/43 GHz over three epochs in 2014 and collected 109 sets of Very Long Baseline Array (VLBA) archival data at 43 GHz between 1996 - 2025. We imaged the parsec-scale jet and parameterized it using circular Gaussian fittings to the UV visibilities. Finally, we derived the inner jet PA and the core flux densities for the VLBA data. The jet presents a twisted morphology in the KaVA maps. The PA of the fitted Gaussian components is in the range between 170 deg and 195 deg. Our kinematic analysis using the VLBA data indicates that the PA oscillates with an amplitude of 7.77 pm 0.79 deg and a period of 10.94 pm 0.22 years, presented for the first time in this work. This oscillation is topped by a continuous clockwise shift of the PA by -0.83 pm 0.07 deg/year. We also identified a strong core flux variability with possible periodicity and a 2 sigma correlation between the core flux density and the inner jet PA change. We discuss possible physical models that could explain the observed features for this object; in particular, a supermassive black hole binary (SMBHB) system, Lense Thirring (LT) effect, and jet or disk instabilities. The oscillation and continuous shift of the PA and the possible radio flux periodicity, together with the optical flux periodicity of approximately 2 years that had previously been confirmed in several independent studies, favor a jet precession scenario driven by orbital motion and disk-orbit misalignment in a SMBHB system
