HAL - La Rochelle Université, Archives Ouvertes
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L2 Acquisition of prosodic cues for disambiguating wh-words in Korean: Evidence from French-speaking learners
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Using the nanoindentation to question the impact of hydrogen on the elasticity and plasticity behaviors of pure nickel
No full textInternational audienceThe influence of electrochemical hydrogen charging and subsequent room temperature hydrogen desorption on elastic modulus, incipient plasticity (or pop-in) and indentation hardness were investigated in nickel single crystals using a series of nanoindentation tests. The evolution of hydrogen and vacancies contents during the desorption was analysed using thermal desorption spectroscopy and differential scanning calorimetry. Antagonist softening and hardening effects of hydrogen are related and commented on the base of TEM, HR-EBSD observations and Molecular static simulations using embedded-atom method potential. The irreversible reduction of reduced modulus, i.e., softening in the elastic regime, is a result of hydrogen induced vacancy clusters in the surface and subsurface zones due to the hydrogen charging. The analysis of incipient plasticity disclosed the hydrogen-vacancy clusters enhanced lattice friction against the formation of dislocation, which resulted in an increase in the critical load and critical resolved shear stress for the first pop-in. Moreover, the activation volume for the pop-in and dislocation nucleation decreased by the hydrogen intake. From this, it is rational to conclude that the mechanism governing the pop-in in hydrogen charged conditions is the hydrogen-vacancy clusters induced heterogeneous dislocation nucleation on a subsurface
Integration of indicator outcomes for assessing good environmental status: A model-based approach
No full textInternational audienceIntegrated assessments are required to track ecosystem status, any change thereof and progress due to conservation measures. The European Union Marine Strategy Framework Directive (MSFD), which aims among others at maintaining biodiversity, requires regular quantitative assessments built from monitoring data and indicator developments to decide on the environmental status of each element in a marine ecosystem. Beyond the daunting tasks incurred with large-scale monitoring and timely analyses, collapsing the multivariate information from indicators on several species into a single number reflecting an overall environmental status is the challenge associated with integration. The 'One Out, All Out' (OOAO) integration rule is currently in use in part due its simplicity and ease of use. Its main drawback is its built-in sensitivity to error in binary assessment outcomes: statistical noise will dominate integration with an increasing number of species or indicators. We developed a model-based approach to integration for MSFD assessments within the statistical framework of Signal Detection Theory. We benchmarked the model performance against the OOAO integration rule in a simulation study. The model-based integration scheme redresses known deficiencies with the OOAO rule and clarifies statistical assumptions behind integration rules, unifying them across a continuum. We illustrated our approach with a case study on the ecosystem component 'marine mammals' in the Northeast Atlantic. We believe our model-based approach provides a more comprehensive integrated output of ecosystem assessments that aligns better with decision-making under uncertainty in evidence-based policy
Mécaniques de jeu pour représenter les socio-écosystèmes : des clés pour concevoir des jeux sérieux
No full textInternational audienceConçu comme un guide pour les concepteurs de jeux sérieux, débutants ou expérimentés, cet ouvrage proposed’explorer les mécaniques de jeu et les procédés ludiques issus des jeux de société modernes pour aborder lacomplexité des socio-écosystèmes. Il offre des pistes de réflexion pour représenter, à travers le jeu, les dynamiques,tensions et interdépendances qui caractérisent les relations et échanges entre acteurs, les processus écologiques etnaturels, les activités économiques, organisationnelles ou sociales. Le cœur du livre est structuré autour de six grandesthématiques: l’accès et le traitement de l’information, l’organisation et la coordination, la négociation et la recherche decompromis, la gestion des ressources naturelles, le fonctionnement des marchés et des filières, et la gestion desrisques et la résilience des socio-écosystèmes. Chaque thématique fait l’objet d’un chapitre qui s’appuie sur dessituations concrètes rencontrées sur le terrain, et met en regard les enjeux soulevés avec des mécaniques de jeu oud'autres éléments de conception permettant de les explorer dans un cadre ludique. L’ouvrage, pris dans son ensemble,invite à une réflexion sur la manière dont le jeu peut exprimer des tensions, faire vivre des expériences qui stimulent ladiscussion et la réflexion sur les enjeux du monde réel. Le lecteur pourra naviguer entre les chapitres selon ses centresd’intérêt et s’appuyer sur les annexes pour enrichir sa culture ludique et prolonger sa réflexion. Bien que l’accent soitmis sur les jeux à visée pédagogique, exploratoire ou transformative, ce guide reste une ressource ouverte pour toutepersonne cherchant à concevoir des jeux de société, quels qu’en soient les objectifs, dès lors qu’ils traitent d’enjeuxsystémiques et concrets
Plastic responses of Plasmodium relictum to competent and non-competent mosquito bites
No full textInternational audienceEnvironmental unpredictability challenges the transmission success of vector-borne parasites like Plasmodium , whose fitness depends on synchronizing the production of transmission forms, called gametocytes, with vector availability. Although mosquito bites are known to trigger Plasmodium responses, it remains unclear whether parasites respond specifically to competent vectors or adopt a generalist strategy. We experimentally infected birds with the avian malaria parasite Plasmodium relictum and exposed them to bites from either a competent ( Culex quinquefasciatus ) or a non-competent ( Anopheles gambiae ) vector species. Both exposures induced a rise in parasitaemia, but the response was significantly stronger to the non-competent species. Host inflammatory, humoral and stress markers remained similar across mosquito treatments, implying that unidentified physiological cues may underlie the parasite’s response. No species-specific modulation of gametocyte conversion rate or sex ratio was observed. These findings suggest that P. relictum does not discriminate between mosquito species, instead employing a generalist, possibly bet-hedging strategy in response to any mosquito bite. Our results highlight the importance of mosquito community composition in shaping parasite transmission dynamics. If non-vector mosquitoes enhance Plasmodium transmission investment, shifts in vector assemblages due to climate change or control measures may have unanticipated effects on disease ecology
: [Récits oraux et ethnohistoire des mobilités pédestres en Chine du Nord : le cas des chameliers et des escortes armées (XIXe-début XXe s.)]
No full textInternational audience本次分享尝试从人类学角度出发，探讨清末民初黄土高原与草原之间的步行流动实践。此项工作无意提供对商队系统的全面还原，亦不求严格意义上的历史重建，而是借助地方口述资料（部分见于文史资料）与田野访谈，思考流动如何被组织、感知、记忆与传承。通过与山西形意拳、心意拳传人交流——其中包括驼队的护镖者的血缘或类属亲属后代——分析镖师所体现的身体知识与技术性实践。商业行号、驼队与镖局虽在具体职能上分工明确，却在社会层面构成了一个相互关联的组织网络。口述叙事中呈现的“步行者” 个体经验，则引导我们思考，在这一具有集体性特征的协作体系中，个体知识与技艺所处的位置及其所承载的意义
Feather corticosterone and stable isotopes explain fledging and adult breeding success in a burrow-nesting seabird, the Yelkouan shearwater Puffinus Yelkouan
No full textInternational audienceAbstract Seabirds face a trade-off between offspring provisioning and foraging effort. The hormone corticosterone regulates energy balance, while stable isotopes are proxies for diet composition. Measurements of Mercury (Hg), corticosterone (CORT f ) and stable isotope values of C (δ 13 C) and N (δ 15 N), integrated during feather growth in Yelkouan shearwater ( Puffinus yelkouan ) nestlings, were used to understand whether chick provisioning explains fledging and adult breeding success. Chicks at colonies and fledglings that failed their first fledging attempt were sampled in three breeding seasons (2020–2022) on Malta (36.01° N, 14.35° E). Failed fledglings were found at sea unable to fly or on urban coasts, presumably attracted by light pollution. Adult shearwaters were GPS-tracked in multiple seasons (2012–2022). Differences in provisioning measures (δ 15 N, δ 13 C and CORT f ) between failed fledglings and chicks at colonies, associations between provisioning and adult breeding success, and adult foraging strategies were investigated. Shearwater nestlings showed a response to variations in diet, by which CORT f was inversely related to δ 15 N and δ 13 C. Hg load was larger at higher trophic position, while there was no evidence for CORT f suppression by Hg. Failed fledglings had disproportionally higher CORT f , indicating that rearing conditions affect fledging success. Adult breeding success was related to provisioning in nestlings, while adult shearwaters at the colony with higher breeding success made shorter foraging trips. Findings suggest that several chicks experience sub-optimal provisioning, with negative implications on fledging and grounding risk during light pollution attraction. Foraging conditions affect adult breeding success, specifying that seabird conservation at colonies needs complementary marine restoration
From Kerguelen to Brazil: Insights into the movement and health of a threatened seabird, the White-chinned Petrel Procellaria aequinoctialis
No full textInternational audienceThis study presents the case of a White-chinned Petrel Procellaria aequinoctialis that was tagged as a fledgling in April 2023 in the Kerguelen Islands, southern Indian Ocean, and subsequently rescued on the southeast coast of Brazil in July 2024. Upon recovery, the petrel displayed symptoms of exhaustion, malnutrition, and anemia, highlighting the substantial energy demands associated with its extensive journey of over 10,000 km. Rehabilitation efforts were successful, resulting in the bird's release after a month of intensive care, which involved nutritional support and monitoring of its health parameters. This case highlights the importance of long-term coastal and marine monitoring programs, which provide valuable data about the health challenges of seabirds, their long-distance movements, and the impacts of human activities on their populations.</div