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A closer look into copepod’s morphology: in situ imaging reveals links with environment and marine heat waves
No full textInternational audienceWithin marine mesozooplankton communities, copepods are a key group both in terms of abundance and biomass, hence contributing to central ecological functions of aquatic ecosystems. Analyzing their morphological traits can provide valuable insight into ecosystem processes and relation with the environment that might otherwise go unnoticed. Imaging techniques are an increasingly used tool to sample the traits of mesozooplankton, and especially of copepods. In this study, we use in situ imaging from the Underwater Vision Profiler (UVP) to explore the relationship between copepod’s morphology and environmental conditions in the upwelling of the California Current Ecosystem (CCE). Over 4 years, from 2008 to 2016, morphological traits such as size, complexity, and transparency were measured from copepod’s images captured by the UVP deployed as part of the CCE-Long-Term Ecosystem Research. Our findings reveal that copepod’s size is linked with environmental seasonal variations, with larger copepods in fall, smaller in summer/spring and even smaller during a summer marine heatwave. Change of transparency also occurs during seasons, especially between spring and fall showing a significant relationship between copepod transparency and seasonal productivity. Interestingly, our results indicate more transparent copepods in the CCE are associated with higher carbon flux. By uncovering these morphological-environmental patterns, our study contributes to a better understanding of copepods’ roles in aquatic ecosystem functioning and consequences of environmental change on this group
Modélisation et simulation d’applications collaboratives à l’échelle de la ville intelligente à l’ère de la 5G
No full textIn a world transitioning to smart cities and sustainable transport, mobility is a central issue for urban efficiency and quality of life. It is in this context that vehicular applications have emerged, thanks in particular to 5G technology integrating Internet of Things (IoT). The aim of these applications is to help drivers make optimal decisions during their travels, depending on traffic conditions. Ensuring their reliability before deployment is imperative. However, the cost of evaluating such applications on a large scale is significant. Simulation is therefore a particularly suitable means of carrying out these evaluations. The approach generally adopted is to couple a discrete-time mobility simulator (on the order of half a second) with a communications simulator. Since commu-nication transmission times can be of the order of half a millisecond or less, this coupling is not particularly accurate. This thesis proposes to integrate both vehicle micro-mobility and communications micro-simulation into a single simulation model. It is based on a discrete-event formalism, Parallel-DEVS, hybridized with UML state machines. The proposed framework is component-based, with each model corresponding to an element of the road or communications infrastructure. The vehicle dynamics model at the heart of the mobility simulation is a discrete-event adaptation of a discrete-time model : Gipps. This all-discrete-event approach ensures greater accuracy in the simulation of communications, as well as greater efficiency in terms of execution time. Thesimulation of 5G communications can be used to evaluate different infrastructures as well as cooperative vehicular applications. It relies on Coupechoux’s models based on real-life observations. Finally, the simulation can be carried out on a city scale, using real cartographic data. For mobility simulation, the results show the effectiveness of adapting vehicle dynamics to discrete events. The evaluation of 5G architectures reveals better performance for relay antenna architecture than for a single global antenna.Dans un monde en pleine transition vers des villes intelligentes et des transports durables, la mobilité est un enjeu central pour l’efficacité urbaine et la qualité de vie. C’est dans ce contexte que sont apparus les applications véhiculaires, notamment grâce à la technologie 5G intégrant l’Internet des Objets (IoT). Ces applications ont pour objectif d’aider les conducteurs à prendre des décisions optimales lors de leurs trajets, selon les conditions de circulation. S’assurer de leur fiabilité avant déploiement est impératif. Néanmoins, le coût associé à l’évaluation à grande échelle de ce genre d’applications est important. La simulation serévèle alors être un moyen tout particulièrement adapté d’effectuer ces évaluations. L’approche généralement opté est de coupler un simulateur de mobilité à temps discret (ordre de la demi-seconde) avec un simulateur de communications. Les temps de transmission dans les communications pouvant être de l’ordre de la demi-milliseconde ou moins, un manque de précision apparaît alors dans ce couplage. Le travail de cette thèse propose d’intégrer en un seul modèle de simulation à la fois la micro-mobilité desvéhicules et les communications. Le tout repose sur un formalisme à événements discrets, Parallel-DEVS hybridé avec les UML state machines. Le framework proposé est à base de composants, où chaque modèle correspond à un élément de l’infrastructure routière ou de communications. Le modèle de dynamique des véhicules au coeur de la simulation de la mobilité est une adap-tation en événements discrets d’un modèle à temps discret : Gipps. Ce choix du tout événements discrets permet une meilleure précision dans la simulation des communications, ainsi qu’une meilleure efficacité en termes de temps d’exécution. La simulation des communications 5G permet d’évaluer aussi bien différentes infrastructures que des applications véhiculaires coopératives. Elle se repose sur les modèles de Coupechoux basés sur des observations réelles. Enfin, la simulation peut s’effectuer à l’échelle d’une ville en utilisant des données cartographiques réelles. Les résultats montrent pour la simulation de mobilité l’efficacité d’adapter la dynamique des véhicules en événements discrets. L’évaluation des architectures 5G révèle quant à elle de meilleures performances pour l’architecture des antennes relais que pour une seule antenne globale
Adapted Physical Activity for Elderly People and National Policies. A Comparative Investigation
No full textInternational audienceThe global demographic transition presents challenges and opportunities for Western societies, affecting biological, psychological, and social aspects. Ageing is linked to a decline in physical abilities, worsened by sedentary lifestyles, which reduce autonomy and quality of life. Public policies must promote “active ageing,” with APA as a key tool to address ageing‐related issues. This study examines APA policies in Italy, France, and Belgium, three European countries significantly impacted by demographic changes. Italy's fragmented approach reflects regional autonomy; France has institutionalised APA in preventive health; Belgium's regional innovation is hindered by a lack of national coherence. The paper emphasises the need for a holistic integration of sociological, psychological, and institutional approaches to support active ageing effectively. It calls for a shift from traditional biomedical models to more inclusive frameworks that respect older adults' autonomy and dignity, offering valuable insights for shaping future strategies to address an ageing population's evolving needs
Slow learners: Body pedagogics and learning slow ways in sport and physical cultures
No full textInternational audienceThis article addresses recent calls for sociological investigation into the embodied incorporation of non-normative cultures, employing the emergent conceptualization of ‘slow’ in sports and physical cultures. In contrast to sports that valorize quantification and maximization of performance via speed, skill and/or endurance, the concept of slow helps analytically explore the pleasures and benefits of slower ways of engagement with sport and physical cultures. Drawing on original findings from three auto-/ethnographic research projects, here we investigate the sensory dimension of learning slow in two distinctive sports/physical activities that were found to share many sensory pleasures (and some corporeal challenges): countryside walking in England and coastal sea walking (longe-côte) in northern France. Employing conceptual insights drawn from Chris Shilling's work on body pedagogics, we highlight the importance of learning to ‘do slow’, which often requires considerable somatic and sensory (re)learning to reconceptualize and transform our experiences of ‘fast’ sporting embodiment
Seafoam avoidance is driven by both chemosensory and contact cues and points towards the presence of soft-surface thigmotaxis in the intertidal gastropod Littorina littorea
No full textInternational audienceSeafoam accumulation in coastal waters has long been acknowledged as ecologically, socially and economically relevant. However, its putative effects on the intertidal biota have been alarmingly under-researched despite the ubiquitous nature of onshore foam formation. This study examines the behavioural responses of the common periwinkle, Littorina littorea, exposed to two types of seafoam: a fresh seafoam (freshly formed) and an aged seafoam (collected after three hours of exposure in the field), using experimental assays carried out under controlled laboratory conditions. L. littorea consistently avoid seafoam, and exhibit a stronger aversion for fresh seafoam. They avoid crossing both seafoam, suggesting that contact cues play a crucial role in this avoidance behaviour. In this context, we introduce the concept of soft-surface thigmotaxis, by which L. littorea is able to follow soft physical discontinuities. Snails exhibited more tortuous movements and reduced speed before actually getting into physical contact with the fresh seafoam, suggesting that chemosensory influence foam avoidance, probably due to repellent volatile compounds requiring further identification. Observations suggest that snails show differential responses potentially influenced by variations in foam properties, such as phytoplankton content and the physical properties of the seafoam. Seafoam avoidance by L. littorea could have wider ecological implications by disrupting the snails' ability to find refuges, increasing their vulnerability to other environmental stresses. Investigating surfactants and pollutants in seafoam is crucial due to their toxicity to aquatic life. The study highlights the need for interdisciplinary research to fully understand and mitigate seafoam's effects on intertidal organism
Assessment of metals/metalloids and organic pollutants in road dust: a case study of diverse land uses
No full textInternational audienceGiven the limited studies of road dust pollution profiles, particularly in terms of inorganic and organic pollutants, in theeast areas of Algiers, this study provides a comprehensive assessment, focusing on both metals/metalloids and organiccompounds. It examines five locations, including urban/residential areas (S1-UR), busy highways (S2-TR and S3-TR),and industrial zones (S4-ID and S5-ID). Inductively Coupled Plasma–Atomic Emission Spectrometry (ICP–AES) and GasChromatography–Electronic Impact–Mass Spectrometry (GC–EI–MS) were used to analyze heavy metals and organiccompounds including n-alkanes, phenols, phthalates, polycyclic aromatic hydrocarbons, fatty acid methyl esters (FAMEs)and other organic contaminants, while Scanning Electron Microscopy (SEM) characterized the morphology and size ofthe road dust particles. The study reveals extremely high Enrichment Factor (EF) values for Cd and Sb (EF>40), andhigh enrichment for As (EF 20–40). The Geo-accumulation index (Igeo) indicated moderate contamination for Pb, Ca, As,and Mo (Class 2–3), with Cd and Sb as severe pollutants (Class 5). The Contamination Factor (Cf) showed very highcontamination for Cd, Mo, and Sb (Cf>6). The Pollution Load Index (PLI) identified elevated pollution levels (PLI>1)for As, Cd, Mo, Sb, Sr, and Pb, especially in industrial and traffic-heavy areas. Compared to similar sites worldwide, roaddust in East Algiers exhibited elevated toxic metal levels in traffic and industrial areas, exceeding global benchmarks. SEManalysis indicated a mix of anthropogenic and natural sources, with particle abrasion and corrosion processes. PrincipalComponent Analysis (PCA) and Positive Matrix Factorization (PMF) identified three groups of contaminants ‘sources,and targeted mitigation strategies were proposed for each group's specific sources
New modelling for reactive transport in shallow aquifers
No full textThis article presents an innovative approach to modelling the vulnerability of shallow aquifers to agricultural pollution. The goal is to develop an alternative to conventional 3D models-typically based on the combination of reactive transport, 3D Richards flow, and non-linear mass action laws-by explicitly accounting for the "shallow" nature of the aquifer.Our approach relies on a simplified flow model specifically designed for this type of aquifer. This model, developed in previous work, describes groundwater movement by coupling horizontal 2D flow within the water table (based on the Dupuit-Forchheimer assumption) with a network of vertical infiltration columns that link the surface to the water table (modeled using 1D Richards flow). Building on this framework, we introduce a reactive transport model that maintains the same simplified structure. The objectives of this work are threefold:First, we propose a coupled transport model that describes horizontal solute transport in the water table, fed by perfectly vertical solute transport from the surface.Second, we perform a formal asymptotic analysis to provide a rigorous mathematical justification for the model, demonstrating that it approximates the full 3D transport problem across a wide range of temporal scales. Finally, we present numerical simulations of nitrate dispersion in a realistic subsurface setting, where chemical equilibrium is computed using the Anderson acceleration algorithm.</p
Identifying linear Ultra-Short Peptides in Agrifood: Challenges and Critical Insights.
No full textInternational audienceThis is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain
Towards an ecosystem approach to a simulated floating wind farm combined with climate change in the Bay of Biscay (France)
No full textInternational audienceThe Bay of Biscay includes areas of environmental importance, with a wide variety of benthic habitats and rich biodiversity. However, it experiences strong anthropogenic pressures, and the effects of climate change are already evident. Renewable energy infrastructures are set to be installed with the aim of reducing the carbon footprint by 2050. However, their effects on the environment demonstrate the need for holistic studies prior to project design. The Ecopath with Ecosim model can be used to model the entire food web and explore different scenarios for changes in the Bay of Biscay. In this study, four scenarios are developed: (1) a reference scenario based on the 2007-2016 environmental conditions; (2) a climate change scenario (increased production and consumption rates of fish to reflect rising sea temperature, presence of non-indigenous species and local distribution maps derived from species distribution models); (3) an offshore wind farm scenario (a biofouling group, wind farm area closed to fishing activities and increased suitability of the area for species likely to aggregate under the turbines); (4) a cumulative effects scenario. The results are analyzed in terms of biomass and catches within the wind farm and the surrounding area. The main findings are that (1) the arrival of non-indigenous species could lead to a change in the structure of the local food web, resulting in a general increase in fish biomass; (2) the attractiveness of the wind farm generates cascading effects; (3) the combination of the wind farm and climate change could cause contrasting effects on biomass and catches depending on the trophic groups, as well as a potential reorganization of the current food web. These results reflect potential effects of floating wind farms on the structure of the food web that should be considered in fisheries management scenarios in the context of a changing environment
Agri-food supply chain network design : A comprehensive review and future research directions
No full textInternational audienceAgri-Food Supply Chain Network Design (AFSCND) is a growing field of research, as it has been and continues to be crucial in ensuring food security. In modern supply chain design, strategic decisions increasingly reflect the interaction between profit-driven enterprises and sustainability-focused regulatory bodies. Despite the existence of several review papers, a systematic review that synthesizes and analyzes recent contributions to the design of agri-food supply chain networks, as a strategic decision, within a framework emphasizing perishability modeling, sustainability, resiliency, and the role of Artificial Intelligence (AI) is still needed. This paper aims to fill this gap by focusing on how the literature addresses (i) strategic decisions and their coordination with either the tactical, the operational levels, or both, within forward or closed-loop supply chains (CLSCs); (ii) perishability modeling, a critical characteristic of many agri-food products; (iii) solution approaches, key decision variables, and uncertainty modeling; and (iv) the integration of AI techniques at the strategic level of network design. By evaluating the interplay among these elements, our objective is to provide a clear overview of current advancements, identify research gaps, and propose future directions for designing sustainable and resilient agri-food supply chains