Dans la foulée des différentes vagues de mobilisation et de contestation des années 2010, les théories de la démocratie radicale ont permis de réfléchir à nouveaux frais au rapport des mouvements sociaux à la démocratie en les associant à un idéal d’insurrection populaire. Or, il découle de cette association une conception particulière de la conflictualité politique qui est susceptible de renoncer aux promesses pratiques et normatives de la démocratie. S’agissant de dépasser cette conception de la conflictualité politique et de réaffirmer la spécificité de l’apport démocratique des mouvements sociaux, cet article entend étayer l’hypothèse d’une institution insurgeante de la démocratie en soutenant que les mouvements sociaux contribuent par leurs pratiques contestataires à produire et à transformer l’ordre démocratique.

We study quasi-stationary distributions and quasi-limiting behaviour of Markov chains in general reducible state spaces with absorption. First, we consider state spaces that can be decomposed into two successive subsets (with communication possible in a single direction), differentiating between three situations, and characterize the exponential order of magnitude and the exact polynomial correction, called the polynomial convergence parameter, for the leading-order term of the semigroup for large time. Second, we consider general Markov chains with finitely or countably many communication classes by applying the first results iteratively over the communication classes of the chain. We conclude with an application of these results to the case of denumerable state spaces, where we prove existence for a quasi-stationary distribution without assuming irreducibility before absorption, but only aperiodicity, existence of a Lyapunov function, and existence of a point with almost surely finite return time.

This study documents and analyzes arthropod trackways from the Upper Cretaceous Wapiti Formation, located in west-central Alberta, Canada. In general, the ichnotaxonomy of arthropod trackways is problematic due to inconsistent use of diagnostic criteria in previous studies. Thus, the trackways from the Wapiti Formation are described following recently defined criteria to facilitate future ichnotaxonomic reevaluations. Judging primarily from the number and morphology of the imprints and the symmetry of the track series, the trackways are identified as Octopodichnus cf. O. raymondi Sadler, 1993. Other relevant track attributes include heteropody and great imprint depth. The mudstone slabs bearing the trackways also contain other well-preserved invertebrate trace fossils along with abundant silicified plant material. The silicified plant fragments, taken together with bentonite overlying the trace-bearing surface, suggest volcanic ash played a role in preserving the trackways. The associated traces include burrows, fecal mounds, and surficial marks and contribute to a diverse invertebrate trace-fossil assemblage. The Wapiti Formation trackways are attributed to crayfish or similar decapods and were emplaced in a succession interpreted to have been deposited in a swampy floodplain environment. By contrast, previously described examples of Octopodichnus have typically been attributed to arachnids in aeolian/desert environments. This paper expands the ichnological record of crayfish-like arthropods from the Late Cretaceous and contributes to the underexplored invertebrate fossil record of the Wapiti Formation and, more broadly, Cretaceous strata in the Western Canada Sedimentary Basin.

This article examines how antimicrobial resistance (AMR) policies designed for livestock farming in Europe—and particularly France—have been limited by narrowly defined reduction targets. Although these policies have significantly decreased antibiotic use, they have also upheld a productivist agricultural model that continues to threaten human and animal health and the environment. By aligning AMR mitigation efforts with a biosecurity paradigm that is highly compatible with industrial livestock systems, the reduction in antibiotic use has not yielded all the anticipated benefits. Based on this assessment, we propose three avenues for fostering a just transition relevant to all sectors involved in AMR governance: transcending the dominant “One Global Health” paradigm; shifting power from institutional stakeholders to the public affected by AMR; and reimagining post-antibiotic futures that extend beyond prevailing dystopian narratives.

The emergence of large-scale spatial modulations of turbulent channel flow, as the Reynolds number is decreased, is addressed numerically using the framework of linear stability analysis. Such modulations are known as the precursors of laminar–turbulent patterns found near the onset of relaminarisation. A synthetic two-dimensional base flow is constructed by adding finite-amplitude streaks to the turbulent mean flow. The streak mode is chosen as the leading resolvent mode from linear response theory. In addition, turbulent fluctuations can be taken into account or not by using a simple Cess eddy viscosity model. The linear stability of the base flow is considered by searching for unstable eigenmodes with wavelengths larger than the base flow streaks. As the streak amplitude is increased in the presence of the turbulent closure, the base flow loses its stability to a large-scale modulation below a critical Reynolds-number value. The structure of the corresponding eigenmode, its critical Reynolds number, its critical angle and its wavelengths are all fully consistent with the onset of turbulent modulations from the literature. The existence of a threshold value of the Reynolds number is directly related to the presence of an eddy viscosity, and is justified using an energy budget. The values of the critical streak amplitudes are discussed in relation with those relevant to turbulent flows.

Urban agriculture on extensive green roofs (EGRs), which are lightweight, shallow-profile systems with low maintenance, presents a viable opportunity to enhance food production and ecosystem services in cities. However, the harsh environmental conditions typical of EGRs pose challenges for crop cultivation, especially regarding water availability. This study investigates whether facilitative interactions with a common green roof cover species, Sedum, with bush beans (Phaseolus vulgaris) as our model crop, can improve crop performance under water stress. We tested 48 EGR modules with three planting designs (no Sedum, artificial Sedum, and live Sedum) under two watering regimes (high and low) at a green roof testing facility in Toronto, Canada, and measured above- and belowground functional traits of beans to assess productivity and trait plasticity. Results revealed that water availability had a greater influence on bean performance than planting design, where beans grown with artificial Sedum under high watering showed the highest shoot biomass and yield, while performance declined significantly under low water conditions, particularly with live Sedum. Leaf physiological traits were largely unaffected by treatment, likely due to the variable rooftop conditions, and root traits were significantly influenced by both water availability and planting design. Hypervolume analyses showed that beans exhibited greater root trait plasticity than Sedum, suggesting a stronger capacity to adapt to water stress. Contrary to the hypotheses, live Sedum did not consistently facilitate bean performance, and potential competitive interactions may have outweighed any stress-ameliorating effects. These findings show water management as the main management variable for crops on EGRs. To transition EGRs into viable agricultural spaces, future strategies should explore alternative facilitative species, nutrient amendments, and microbial inoculations to support crop resilience.

The interaction between a coherent vortex ring and an inertial particle is studied through a combination of experimental and numerical methods. The vortex ring is chosen as a model flow ubiquitous in various geophysical and industrial flows. A detailed description of the vortex properties together with the evolution of the particle kinematics during the interaction is addressed thanks to time-resolved particle image velocimetry and three-dimensional shadowgraphy visualisations. Complementary, direct numerical simulations are realised with a one-way coupling model for the particle, allowing for the identification of the elementary forces responsible for the interaction behaviours. The experimental and numerical results unequivocally demonstrate the existence of three distinct interaction regimes in the parameter range of the present study: simple deviation, strong deviation and capture. These regimes are delineated as functions of key controlled dimensionless parameters, namely, the Stokes number and the initial radial position of the particle relative to the vortex ring axis of propagation.

This article provides a capabilities analysis of the financial behaviour of United Kingdom-based Zimbabwean senders of international remittances to Zimbabwe. It elaborates an expanded analytical framework of financial capability to investigate the effects of remitting on the financial capabilities of the senders of remittances. The data presented draw on the findings of a survey (n = 347) and semi-structured interviews (n = 23) conducted with Zimbabweans in the United Kingdom. The data reveal adverse effects of remitting on the respondents’ personal financial practices in respect of budgeting, saving and preparing for their retirement. It also shows the limits of FinTech services in transferring remittances and provides insights into how personal finance and -related capabilities constitute a social remittance. Overall, discourses on migration and development need to incorporate an expanded financial capabilities perspective to understand better how remittance fields are structured and to contribute to public policy reforms aiming to enhance the efficacy of remittances.