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Modelling genetic and epigenetic selection signatures from pool sequencing.
No full textInternational audienc
Communal studies and intentional communities: key features and main contributions to the understanding of the social and solidarity economy
No full textInternational audienceThis chapter situates intentional communities, including ecovillages, kibbutzim, communes, and other utopian communities, within the realm of the social and solidarity economy (SSE), while also presenting the original contributions of communal studies to the theoretical understanding of this field. As a specific type of organization within the SSE, intentional communities, which bring together a group of individuals who share some or all of their goods and resources, shed light on two main questions: first, the commitment of members to the organization, and second, how to assess the success of organizations beyond the question of longevity
Spatial variability in nutrient and organic matter concentrations during hydrological fragmentation of an intermittent temperate catchment
No full textThis research was funded by the AQUA division of the Institut national de recherche pour l’agriculture, l’alimentation et l’environnement (INRAE), the Brittany region, and the Observatoire des sciences de l’environnement de Rennes (OSERen).International audienceIntermittent and ephemeral streams are watercourses that cease to flow and/or dry up during part of the year. Their seasonal drying is sometimes preceded by a stream fragmentation phase with formation of isolated pools where the biogeochemistry differs from that of perennial reaches. Our objective was to analyse how hydrological fragmentation alters the spatial variability in dissolved nutrient and organic matter concentrations in a temperate-oceanic and agriculture-impacted headwater stream, where nutrient loadings are high. We conducted repeated synoptic sampling campaigns at high spatial resolution (150–200 m) along the stream network of the Naizin catchment (7 km2) during the spring–summer-fall of 2023. We sampled 38 sites and analysed dissolved organic carbon (DOC) concentrations and fluorescence properties, dissolved inorganic nitrogen (DIN) and soluble reactive phosphorus (SRP) concentrations, during four sampling campaigns: stream recession, early and late fragmentation and reconnection. Our results showed an increase in the spatial variability of concentrations, with monotonic longitudinal gradients along the stream disappearing during hydrological fragmentation. Both DOC and SRP concentrations were higher in isolated pools than in flowing reaches, while DIN concentration was lower. The chemical composition of DIN and DOC also changed with stream fragmentation, with increasing proportions of nitrite and ammonium in DIN and humic-like organic matter in DOC. These results suggest that the main controlling processes in the isolated pools were streambed mobilisation of SRP and DOC, along with denitrification under anoxic conditions. We expect the observed spatio-temporal patterns in nutrient and DOC concentrations to become more widespread in the future as intermittent streams will become more frequent owing to climate change
A digital twin integrating multi-objective optimization to support fryer operators in managing potato crisps production
No full textInternational audienceThe production of potato crisps currently relies on the expertise of human operators, known as fryers, whose training is long and demanding. With the decline in fryer vocations and the increase in consumer quality expectations, it is now essential to develop decision-support tools to make fryer work easier and better control product quality. This study proposes a digital twin (DT) approach that incorporates multi-objective optimization to assist fryers in managing their crisp production line. Data from crisp production is collected and used to model key crisp physicochemical indicators (Fat content, Moisture content, and Lightness) using a Machine Learning approach, specifically the Random Forest method. Then, a multi-objective optimization is carried out using the Non-dominated Sorting Genetic Algorithm II (NSGA-II) algorithm, which identifies optimal adjustments to enhance the three crisp physicochemical indicators. The optimization is tested on 2 batches of potatoes as inputs. The algorithm generates a set of optimal solutions, from which a final solution is selected using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) multi-criteria decision-making method. This solution provides practical recommendations for adjusting production parameters according to a given potato batch quality. The results show that physicochemical parameters of the crisps are similar after optimization, regardless of the quality the potato batch. Variation in potato batch quality is compensated by appropriate adjustments of the crisp manufacturing process parameters ensuring consistent and optimal production. In conclusion, this digital twin, integrating multi-objective optimization, proves to be a valuable tool for improving fryer decision-making and optimizing production line management
Wheat growth model capturing growth-defense trade-off
No full textInternational audienceImproving crop productivity in agroecological systems subject to multiple abiotic and biotic stresses requires a comprehensive integration of physiological mechanisms into plant growth models. In this article, we analyze the structure, components and limitations of current process-based models (PBMs) and Functional-Structural Plant Models (FSPMs) used to simulate wheat (Triticum spp.) growth. Although these models are well adapted to represent light interception, carbon assimilation and biomass allocation, they remain mostly oriented toward yield or growth prediction and usually neglect biotic and abiotic stress factors, which are crucial under agricultural conditions. In this article, we review the main physiological concepts of growth, including photosynthesis, nitrogen uptake, source-sink relationships and respiration costs, with an emphasis on resource allocation trade-offs. These trade-offs, particularly between growth and defense, are rarely explicitly integrated into current modeling frameworks, despite their decisive role on yield and growth under stresses. To fill these gaps, we propose a conceptual model that explicitly integrates physiological trade-offs between growth and defense, as well as hormonal signaling networks. By adopting a more explanatory and integrative approach, this work aims to improve the ability of models to facilitate the transition towards a stronger integration of agroecological principles
Contributions to the development and simulations of generic, modular and multiphysics greenhouses dynamic models, evaluated with a whole year study case dataset
No full textAlso known as : A greenhouse dynamic model to assess sustainable solutions Contributions to the development and simulations of generic, modular and multiphysics greenhouses dynamic models, evaluated with a whole year study case datasetInternational audienceNorth-Western Europe heated greenhouses need to address their high fossil energy dependency while they start to face with climate change. In this context, physics-based greenhouses dynamic models can be used for prospective assessments of innovative shapes, equipment, control, etc. A prerequisite for such model-based evaluation is a review of existing implementations, the improvement and development of suitable sub-models in a generic and modular approach that do not require calibration, and the evaluation of a use case global model with a solid experimental dataset. First, this paper details contributions to existing models regarding several aspects: solar gain, boundaries effects, airflows and leakages, heat and mass transfer. The second part is dedicated to the evaluation of an experimental tomato greenhouse global model for an 11-month period. Its assessment is multiphysics: indoor climate, utilities consumptions, yield and Leaf Area Index. The resulting 5 min sampling indoor air climate Root Mean Square Error is 1.3 °C (temperature) and 8.1%RH (relative humidity). The tomato yield Mean Absolute Error is 1.1 kg m-2. Mass balances also quantify the losses and potentials for water and CO2. The global model outputs are compared with literature, and it is demonstrated that assessing the accuracy of models based only on statistical indicators is questionable. This approach is compatible with assessments of prospective solutions, it increases the confidence for scaling results from small to large commercial greenhouses, and it constitutes a base from which simpler and black box models can be derived for other applications such as predictive control
Multi-trophic arthropod communities modulated by local farming system and landscape heterogeneity
No full textInternational audienceContext Organic farming is increasingly used worldwide in recent decades, but the role of this farming system in shaping the trophic structure of arthropod communities remains poorly understood, especially at different spatial scales. Therefore, the contribution of landscape heterogeneity in shaping arthropod’s trophic guilds remain understudied. Objectives In this study, we assessed how the evenness, the abundance and the taxonomic richness of arthropod trophic groups were shaped by the local farming system, landscape heterogeneity (including the percentage of semi-natural habitats and organic fields), and their interaction. Methods Arthropod’s trophic guilds (ground and vegetation-dwelling) were sampled in 20 spatial independent pairs of conventional (CF) and organic (OF) fields located in Brittany (Western France) by using pitfall traps and sweep nets replicated in time and space. Results A total of 95,822 arthropods belonging to 197 taxonomic groups were sampled. Farming system has a strong overall positive effect on the community structure of both ground- and vegetation-dwelling arthropods. Landscape heterogeneity, alone and in interaction with farming systems, affected positively the diversity and abundance of most trophic groups for both ground- and vegetation-dwelling arthropods. Organic farming therefore affected the trophic composition of arthropod communities not only locally, but also at the landscape scale. Conclusions Our study highlights the strong positive effect of farming system and the landscape heterogeneity on arthropod communities and more importantly the interconnection between different spatial scales in this process. Taking these aspects into account is therefore crucial in understanding arthropod community dynamics in agroecosystems
Introduction to the social and solidarity economy (SSE) field of research
No full textInternational audienceThe social and solidarity economy (SSE) has long been present across the world. But it is only recently that it achieved formal recognition at the international level. In recent years, in the face of economic, social, and ecological crises, the SSE gained attention for its potential to align the economy with the needs of humans and nature. In this introduction, we give an overview of what the SSE refers to and explain how the present volume contributes to understanding it. We situate this work with regard to a scoping review of recent publications, showing the increasing interest of a dynamic community of scholars in the SSE. We then present the 12 chapters of the volume, grouped into three parts, respectively seeking to (1) define the field; (2) investigate developmental and organizational issues; and (3) examine different approaches to understanding the SSE. We conclude by addressing two issues for future research
Variation analysis of natural ventilation and air temperature within a greenhouse cluster using a large-scale 3D CFD modelling
No full textInternational audienceThere is an increasing number of centralized vegetable productions that appear as clusters of greenhouse rows and columns. Differences in temperature distributions and ventilation rate are not well-known and quantified between these greenhouses. Very few greenhouse microclimate models consider the influence of surrounding greenhouse shading on natural ventilation and the variation caused by it on mass and heat transfer. This paper presents a three-dimensional greenhouse cluster model that covers a total area of 3 ha for an interior and exterior flow field, including 22 greenhouses, which is solved using the finite volume method in conjunction with a supercomputer. One of the major contributions is a proposed optimal mesh design methodology for large-scale greenhouse cluster models. It allows for precise control over the quality and size of the mesh elements. Results show that the simulated MAE (Mean Absolute Error) at the lower/upper vents air speed measurement points and 15 distributed temperature measurement points in a greenhouse are respectively 0.19 m s−1, 0.24 m s−1 and 1.67 ℃. The model was also used to assess the variation of natural ventilation rate and temperature distribution that depends on greenhouse specific position inside a farm. This work contributes to refining greenhouse models and control methods, while also serving as a potential reference for both researchers and practitioners in crop yield and quality prediction