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Migrations in an Irish Context: New Worlds, New Words
No full textInternational audienceThis book addresses the issue of migration from or to Ireland since the 17th-18Th century and examines the dynamics of emigration and immigration down to the present day. It is distinctive through its pluri-disciplinary approach of migrating issues in Ireland but also in the way it confronts individual and collective dynamics in the context of migration. Thus, this book aims at offering a comprehensive and englobing understanding of key issues of migration in Ireland today and their legal, social and linguistic impacts, while also focusing on the representations of the migrating experience in literature, be it in poetry or in fiction. In so doing it also aims at reassessing issues of home, place-making and belonging. The book does not restrict itself to a study of emigration or immigration, nor to a historical or economic approach because its goal is to show the complexity of migrating trajectories, whether individual or collective, and how those migrating stories are inscribed within national and supra national dynamics. The study of the words used to narrate those experiences offers a creative insight into the plurality of migrating experiences, hence the place devoted in this book to literary representations
Le bilinguisme, une fierté identitaire ? Parole aux élèves au Canada
No full textInternational audienc
Enhancing thermal stability and mechanical properties in fully-amorphous ZrCu nanolaminates
No full textInternational audienceThe synthesis of thermally stable metallic glasses (MGs) which are mechanically robust and tunable at elevated temperatures remains a key research challenge. While most strategies focus on complex MG compositions with enhanced resistance to devitrification, we demonstrate that a simple microstructural approach – based on the fabrication of fully amorphous nanolaminates (NLs) – can significantly extend thermal stability even for binary ZrCu system, while retaining strong resistance to deformation. Moreover, we investigated annealing-induced atomic structural modifications (relaxation or partial crystallization). Annealing treatments up to 330 °C (T < Tg, the glass transition temperature) maintain the amorphous structure, while inducing atomic structural relaxation and free volume annihilation, as revealed by HRTEM and the reduction in corrugations on fracture surfaces. Moreover, we report strong layer intermixing with chemical interdiffusion, delaying the onset of crystallization and resulting in superior thermal stability with a fully amorphous structure up to 420 °C, significantly above the crystallization temperature of the individual layers (respectively, 320 and 360 °C for Zr24Cu76/Zr61Cu39). Annealing at T > Tg (∼420 °C) results in a completely homogenous structure without NL features with partial crystallization, forming Cu-Zr-based intermetallic and Zr-oxide phases. We show an increase in elastic modulus and hardness for higher temperatures due to structural relaxation and nanocrystal formation, with a maximum hardness (7.6 ± 0.2 GPa) obtained at 420 °C for 60 mins annealing, ∼20% above the deposited condition. These results highlight the potential of microstructural tailoring of MGs to enhance thermal stability and tailor the mechanical properties, which can be beneficial for advanced material applications
Two-level overlapping additive Schwarz preconditioner for training scientific machine learning applications
No full textInternational audienceWe introduce a novel two-level overlapping additive Schwarz preconditioner for accelerating the training of scientific machine learning applications. The design of the proposed preconditioner is motivated by the nonlinear two-level overlapping additive Schwarz preconditioner. The neural network parameters are decomposed into groups (subdomains) with overlapping regions. In addition, the network’s feed-forward structure is indirectly imposed through a novel subdomain-wise synchronization strategy and a coarse-level training step. Through a series of numerical experiments, which consider physicsinformed neural networks and operator learning approaches, we demonstrate that the proposed two-level preconditioner significantly speeds up the convergence of the standard (LBFGS) optimizer while also yielding more accurate machine learning models. Moreover, the devised preconditioner is designed to take advantage of model-parallel computations, which can further reduce the training tim
From Theorising Othering to Othering Theorising: Reflections from the GWO 2025 Keynote Panel
No full textInternational audienc
Ecological and management drivers of pest regulation via multitrophic pathways in tropical insular agroecosystems
No full textInternational audienceHighlights: • In La Réunion agroecosystems, field vegetation diversity boosts arthropod diversity. • Crop pests and damage decrease with increasing natural enemy diversity. • Pest regulation service benefits from field non-crop vegetation diversity. • Management and landscape factors also affect trophic cascades. • Vegetation diversity effects can outweigh management and landscape factors.Abstract: Natural pest regulation services provided by arthropod natural enemies are a cornerstone of ecological intensification. While vegetation diversification is known to support natural enemy communities, its relative contribution and interactions with other drivers for pest regulation services remains unclear, especially in dynamic and diversified smallholder agroecosystems under the tropics. In this study, we investigate how crop and non-crop field vegetation diversity, farming practices, climatic and landscape parameters jointly shape arthropod community structure and their services in the aerial and ground strata in tropical market gardening systems on La Réunion Island. We surveyed 22 open-field market gardening systems during two seasons. Using a multitrophic, piecewise structural equation modeling approach, we assessed direct and indirect cascading effects of local and landscape factors on arthropod diversity and pest regulation services. Results show that in aerial communities, non-crop vegetation richness generated a positive bottom-up trophic cascade. It enhanced herbivore diversity which, in turn, increased natural enemy richness, ultimately reducing pest abundance and crop damage, particularly during the dry season. In contrast, insecticide use suppressed natural enemy richness and reduced the effectiveness of pest regulation. Ground-dwelling communities were more strongly influenced by landscape fragmentation, semi-natural habitat cover, and temperature, with less evidence for structured trophic cascades. Overall, beneficial cascading effects of vegetation on pest regulation services in above-ground communities may outweigh the impacts of other management and landscape drivers. These findings underscore the potential of promoting vegetation diversity and reducing pesticide use as key strategies for enhancing natural pest regulation in tropical smallholder agroecosystems
Boundary output feedback stabilization of heat-ODE cascades
No full textInternational audienceThis paper studies the boundary output feedback stabilization of heat-ODE cascades. We consider a either Dirichlet or Neumann boundary control input that applies at the left boundary of the heat equation. The PDE enters into the ODE through a either Dirichlet or Neumann trace at the right boundary of the PDE. The system output applies solely to the ODE. The reported approach relies on spectral reduction methods and is conducted through a detailed study of the eigenelements of the heat-ODE cascade. We show that the adopted approach can always be successfully implemented for achieving the output feedback exponential stabilization of heat-ODE cascades in the either L2 -or H1 -norm
Interfacial effects break the canonical permeability-selectivity trade-off in biological nanopores
No full textInternational audienceHypothesisTransport in membrane systems involves a classic trade-off between permeability (how many particles can pass through) and selectivity (the ability to sort specific particles) ruled by the pore size and the inner channel charges. By using interfacial effects from charges on the outer surface of the pore, it is possible to change the channel's conductive properties without altering its physical pore size. This suggests a new way to overcome the permeability-selectivity compromise in unexpected ways.Experiments and theoretical analysisWe perform an exhaustive electrophysiological analysis of the conductive properties of two wide biological ion channels, the bacterial porin OmpF from E. coli and the mitochondrial Voltage Dependent Anion Channel (VDAC), paying attention to the role of membrane lipid charges in the interplay between permeability and selectivity. We examine this interplay using an equivalent circuit model based on the principle of ionic current independence and with numerical simulations derived from Poisson-Nernst-Planck equations based on 3D protein structures at atomic resolution.FindingsWe demonstrate that membrane and pore charges do not compensate for each other. Rather, they function as complementary interaction sites giving rise to unique transport characteristics that can enhance simultaneously both permeability and selectivity beyond the predicted upper limit. Traditionally, efforts have concentrated on functionalizing inner channel surfaces; however, our findings highlight how separately modifying outer channel surfaces can enable nanofluidic devices to overcome the permeability-selectivity trade-off
