HAL - La Rochelle Université, Archives Ouvertes
Not a member yet
19516 research outputs found
Sort by
Introduction générale : vers un management des résiliences
No full textInternational audienceLe terme de résilience a d’abord été employé en mécanique pour désigner la capacité d’un matériau à retrouver son état initial après avoir subi une déformation. Ce principe de retour à un état stable après une perturbation constitue le fondement même de la résilience. Le concept a ensuite été adopté par la psychologie pour décrire la capacité des individus à surmonter des traumatismes graves (ex. guerre, génocide, catastrophe naturelle, violence familiale), voire à devenir plus forts psychologiquement. En France, le neuropsychiatre Boris Cyrulnik a largement contribué à la diffusion de cette notion auprès du grand public et des médias.Aujourd’hui, la résilience s’étend à toutes les sciences humaines et sociales, où elle est utilisée pour analyser des processus dynamiques de transformation et d’adaptation face à l’adversité, souvent assortis d’un renforcement. Cette approche s’applique donc désormais à une très grande variété de contextes : résilience individuelle, organisationnelle, territoriale, climatique, communautaire, familiale, économique, institutionnelle, infrastructurelle… Cette diversité d’applications met certes en lumière la flexibilité et la polyvalence de cette notion, mais elle révèle aussi un risque sous-jacent : celui de sa dilution progressive, voire tout simplement de contre-sens. L’usage de la résilience dans des contextes extrêmement variés rend absolument nécessaire une réflexion rigoureuse sur ses contours conceptuels et sur les enjeux associés à tous les niveaux (individuel, organisationnel, environnemental, sociétal, etc
Base de données des morphèmes sino-japonais d'une unité morphophonologique, à caractère nominal kunc-bd-v1.0.2
No full textBase de donnéesDatabase of 276 nominal Sino-Japanese monomorphemes. Provides morphosyntactic, semantic, and some phonological information.Base de données de 276 monomorphèmes sinojaponais à caractère nominal. Fournit des informations morphosyntaxique, sémantiques et quels informations phonologiques
Multianalytical Study of Archaeological Iron Nails of the Roman Period (First to Third Century) in Northern Spain
No full textInternational audienceIn the archaeometallurgical study of iron nails to investigate Roman manufacturing processes, multi-analyte characterization provides information on alloy composition and microstructure. Nails from the Roman sites of Forua, Aloria, and Iuliobriga (northern Spain) were studied. To characterize the iron phases and microstructures of the nails, optical microscopy (OM), scanning electron microscopy coupled with electron-dispersive spectroscopy (SEM-EDX), micro-Raman spectroscopy, electron backscatter diffraction (EBSD) realized in environmental mode, and microhardness measurements were carried out. The chemical composition of the metal was determined by X-ray fluorescence (XRF). The corrosion mineralogical composition was determined by powder X-ray diffraction (XRD). Aggressive burial conditions had a significant effect on the forms of corrosion of the Forua nails to the point of complete iron loss. Examination of the metal of the nails from the Aloria site revealed that most of the ironwork was made in the villa's own forge. In the case of the Iuliobriga nails, different degrees of forging were identified associated with different workshops
Sediment implication in shift in nutrient limitation and impact on purification capacity: Application on a common Atlantic east coast pond
No full textInternational audienceSalt marshes are widely recognized as regulation areas of nutrient flows to the ocean. However, poor knowledge of nutrient dynamics in these environments counteracts the understanding of nutrient regulation within the land- sea continuum, previous works mainly focusing on the water compartment. To overcome this gap, an experimental pond was monthly (open system) and weekly (closed system) monitored between February and October 2021. Bio(geo)chemical parameters (in water and sediment) and nutrient fluxes at the sediment-water interface (SWI) were relevantly explored to highlight the coupling between the benthic and pelagic compartments. A significant shift from P limitation (February–June period) to N limitation (July–October period) was observed and attributed to the phosphate mobilization (named soluble reactive phosphorus, SRP) processes in the sediment and its effluxes toward the water column. This SRP mobilization was strongly linked to the respiration of iron oxides for mineralization of organic matter (OM) and anammox processes. Surprising high carbon production in September (>1200 mgC. m-3. d-1 ) in a low nutrient concentration range indicated significant regenerated N production and potentially new P production. Monitoring in enclosed system indicated a 3-week water retention time for a maximum nutrient removal and minimal impact for water export to the coastal waters. In non-bloom period, sediment SRP efflux from the sediment could contribute up to 40 % of SRP increase in the water column in September and to 60 % of the P-production demand in October. This work highlighted the importance of sediment for water nutrient re-supply and the temporality of water retention time in pond system to optimize purification effect and limit risks of eutrophication in coastal waters. While the eutrophication potential associated with nitrogen seemed to be reduced in such pond, that of phosphorus needs to be more considered
Current and future perspectives on Lobesia botrana pest oviposition behavior in the context of climate change and fungicide applications.
No full textInternational audienceClimate change-induced temperature increases are likely to promote the spread of insect pests into new regions, requiring adaptations in pest management strategies. Copper-based fungicides are widely used in viticulture to manage fungal diseases, but may also impact non-target insect pests. This study investigated the effects of Bordeaux mixture on the oviposition behavior and egg survival of the grapevine pest Lobesia botrana, under simulated current (2002–2021) and future (2081–2100) climatic scenarios. Laboratory choice and no-choice experiments were conducted to assess oviposition preferences, potential deterrent effects of Bordeaux mixture, and its toxicity to eggs. In the choice experiment, L. botrana females showed significant preference for untreated grapes under both climatic conditions. However, in the no-choice experiment, Bordeaux mixture neither significantly deterred oviposition nor affected egg hatching rate in either scenario. While Bordeaux mixture had minimal influence on oviposition behavior, future climatic conditions significantly reduced female longevity and fecundity. This reduction in reproductive output may suggest lower pest pressure, but accelerated generation turnover and increased voltinism under warmer conditions could amplify pest pressure in the long term. This study provides insights on the collateral effects of Bordeaux mixture on L. botrana under a future climatic scenario and emphasizes the need for further research on its potential impacts on other key life history traits (e.g., development, reproduction). These findings highlight the importance of integrating climate change projections into pest management strategies to ensure sustainable viticultural practices
: conférence croisée entre Annabel Audureau et Isabelle Autissier pour son roman "Soudain, Seuls"
No full textInternational audienceLes robinsonnades modernes réinterrogent le mythe de Robinson en explorant de nouvelles temporalités, notamment à travers desfigures féminines. Contrairement au héros de Defoe, obsédé par la mesure du temps, ces nouvelles robinsonnes s’affranchissent du Chronos pour embrasser le Kairos, un temps de créativité et de transformation. De Le Mur invisible de Marlen Haushofer à Dans la forêt de Jean Hegland, ces récits mettent en scène des héroïnes qui, confrontées à l’effondrement d’un monde, réinventent leur rapport au temps et à la nature. Lors de cet atelier, une discussion avecIsabelle Autissier autour de Soudain, seuls permettra d'explorer ces récits et leur potentiel pour repenser l'avenir
Pseudoalteromonas Strains as Biofilm Control Agents in Ostrea edulis Aquaculture: Reducing Biofilm Biovolume While Preserving Microbial Diversity
No full textInternational audienceBiofilms in aquaculture tanks pose significant challenges, hindering cleaning processes and contributing to antibiotic resistance. This study investigated the effects of four Pseudoalteromonas strains on flat oyster (Ostrea edulis) rearing, with a specific focus on biofilm control and microbial communities. After confirming the safety of these strains for O. edulis, we monitored biofilm development and bacterial communities during a 4-month sexual maturation period. Biofilm biovolume was quantified using confocal laser scanning microscopy (CLSM), and bacterial community composition was analyzed via 16S rRNA gene metabarcoding of both biofilm and seawater samples. Our results revealed differences in bacterial community structure between biofilms and seawater. Furthermore, the presence of specific Pseudoalteromonas strains significantly impacted the composition of bacterial communities within the tanks. β-diversity analyses demonstrated that each strain exerted a unique influence on the bacterial community structure. Some Pseudoalteromonas strains effectively reduced biofilm biovolume without negatively impacting bacterial richness or diversity. These observations suggest that certain Pseudoalteromonas strains can effectively control biofilm formation while maintaining a diverse and potentially beneficial microbial community in O. edulis rearing tanks. The use of these strains as additives in aquaculture systems could offer several advantages, including reduced cleaning time and costs and a potential decrease in biocide usage
A review on deterioration Mechanisms, durability prediction and enhancement techniques for recycled aggregate concrete
No full textInternational audienceThe expanding global construction industry is driven by the need to develop sustainable alternatives to replace natural resources in concrete manufacturing. Reusing construction materials and increasing reuse effectiveness have emerged as popular study areas. Recently, the durability of recycled aggregate concrete (RAC) has drawn attention of numerous researchers worldwide. This review paper discusses the different approaches used to predict the durability of RAC (deterministic, probabilistic, and artificial intelligence). In addition, a critical review of the parameters more influential on the RAC durability performance is presented, including replacement ratio, particle size, chemical admixtures and additives, mixing technique, and curing conditions. Several contradictory results concerning the chloride ingress, carbonation, air and water permeability in the RAC are reported and discussed. The methods used to enhance the characteristics coarse recycled aggregate (CRA) are also categorised and summarised. We have found that complex, non-linear, and multivariable mechanisms control chloride ingress, carbonation, and permeability, rendering conventional modelling techniques inadequate. It is therefore advised to use artificial intelligence methods supported by comprehensive databases to provide precise durability predictions. The performance of RAC is greatly impacted by the adhered mortar (AM) in CRA; its increased porosity and water absorption result in weaker interfacial transition zones (ITZs), decreasing impermeability, and weakening resistance to carbonation and chloride ingress. Therefore, we have also reported that strengthening the microstructure or altering AM characteristics are the main treatment strategies used to increase RAC durability performance. By enhancing RAC performance and lowering the ecological footprint of construction and demolition waste, CRA carbonation stands out among these techniques as a potential technology that offers both technical and environmental benefits.</div
Habituation or sensitization? Short-term adjustment of flight initiation distance in incubating common eiders
No full textInternational audienceOptimal escape theory predicts that prey balance the costs and benefits of fleeing. However, the use of prior experience in prey escape decisions has been overlooked. Indeed, when repeatedly exposed to a nonlethal yet threatening stimulus, prey may adjust their escape response by habituating, delaying escape when repeatedly exposed to that stimulus, or by becoming sensitized, escaping sooner. Here, we investigated intrinsic and extrinsic drivers of short-term variation in flight initiation distance (FID, distance at initiating escape) in response to repeated human approaches in incubating female common eiders, Somateria mollissima. We predicted habituation to repeated exposure to threatening but nonlethal stimuli, reflected in decreased FID. We also expected increased habituation in females with a high current reproductive value (older breeders, females in good condition or laying large clutches) or brood value (early breeders). Last, we investigated whether changes in FID varied with threat level (i.e. different adult or nest predation risk or breeding habitat). The magnitude of change in FID was small and varied among individuals, depending on individual traits (body condition, clutch size and phenology) and perceived threat (island-specific adult predation risk). Accordingly, females in poorer body condition, that laid larger clutches or laid earlier in the season were more prone to become sensitized over repeated approaches. Consistent with the risk allocation hypothesis predicting a dampening of antipredator responses under chronic risk exposure, females were less prone to become sensitized when nesting on islands with high adult predation risk. These results underline the ability of animals to make plastic state-and context-dependent adjustments of antipredator behaviour when repeatedly confronted with nonlethal stimuli. Nevertheless, given the limited magnitude of within-individual, short-term adjustment of FID compared to the among-individual variation in FID, questions remain concerning the efficacy of these antipredator responses in a context of rapidly changing predation regimes