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An optimal time control problem for the one-dimensional, linear heat equation, in the presence of a scaling parameter
No full textInternational audienceIn this paper, we study the optimal time problem for the one-dimensional, linear heat equation, in the presence of a scaling parameter. To begin with, we build an exact solution. The dependence of this solution as regards the scaling parameter naturally opens the way to study the existence and uniqueness of an optimal time control. If, moreover, one assumes the L∞ − null controllability, it enables to establish a bang-bang type property
Freins et leviers à l’insertion des légumineuses : étude comparative de trois territoires contrastés (Bourgogne, Midi-Pyrénées, Pays de la Loire)
No full textNational audienceThis article aims to study the constraints and incentives to the introduction of forage and grain-legumes in farms in three contrasting regions (Bourgogne, Midi-Pyrénées, Pays de la Loire). Surveys to analyze the agronomic and economic determinants of the introduction of legumes on farms were carried out with about 40 farmers in each region. The farmers’ discourses were transcribed and analyzed according to a thematic entry allowing to identify, to prioritize and to quantify the different obstacles and incentives perceived, and to understand their determinants. The results of the surveys show that, in general, the main incentive for the introduction of legumes in the territories is the presence of markets which guarantee a fair and stable price for the sale of legumes. This study also shows that this incentive is not sufficient and that it is necessary to act simultaneously on other obstacles and incentives, which vary in content and importance according to: the type of farming system; the type of crops and their valorization; the territory and its dynamics. In conclusion, this work underlines the importance of adapting the policies to promote forage and grain-legumes to the local context.Dans cette étude, nous nous intéressons aux freins et leviers à l’insertion des légumineuses (fourragères et à graines) dans des exploitations agricoles de trois territoires contrastés (Bourgogne, Midi-Pyrénées, Pays de la Loire). Des enquêtes visant à analyser les déterminants agronomiques et économiques des pratiques d’insertion ont été réalisées auprès d’environ 40 agriculteurs sur chaque territoire. Les discours d’acteurs ont été retranscrits et analysés selon une entrée thématique permettant d’abord d’identifier, de prioriser, et de quantifier les différents freins et leviers perçus, puis d’en comprendre les déterminants. Les résultats mettent en évidence que le principal levier pour l’insertion de légumineuses est la présence de débouchés garantissant un prix de vente des légumineuses satisfaisant et stable. Cependant, cette étude montre que ce levier seul n’est pas suffisant et qu’il est nécessaire d’agir simultanément sur d’autres freins et leviers, qui ne s’expriment pas de la même manière et ne présentent pas la même importance selon : le type d’exploitation agricole ; les cultures et leur valorisation ; les territoires et leurs dynamiques. Ainsi ce travail permet de souligner l’importance de territorialiser les politiques d’aide et d’accompagnement à la relance des légumineuses qui doivent s’insérer dans des logiques d’usage de ces productions pour les territoires
Nouvelles formes de gouvernance dans les Systèmes Alimentaires du Milieu (SYAM), Les cas de l’Isère et du Roannais
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La différenciation par les proximités entre producteurs et consommateurs
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Sustainable management models: innovating through Permaculture
No full textInternational audienceStructured Abstract Purpose Exploring the ways in which innovation can serve to create better and more integrated social, environmental and economic enterprises is a key challenge. How firms innovate and change depends strongly on their management models. Permaculture concepts and principles could help the transition toward more sustainability. The purpose of this study is to understand how management models could rely on Permaculture principles to facilitate innovations and changes toward sustainability. Design/methodology/approach This article helps meet this challenge by exploring possible innovative management models that could help in pursuing sustainability by aligning enterprises with socio-ecological realities. The possible innovative management models built on the Permaculture concepts will be the object of analysis for this study. Findings The literature review shows that there could be innovative management models built on the Permaculture concepts, a potential alternative to Western 'traditional' management models. They would give preference to long-term objectives, intrinsic motivation, emergent coordination, and collective wisdom in decision making. Originality/value It is strategically important to find new concepts, models, methods and practices that will lead society to be ecologically sustainable and socially responsible, besides being economically efficient. These socio-cultural and economic challenges are central to the design and construction of a society in which all individuals feel integrated and responsible
La haie coupe, l'eau relie. Les continuités écologiques requalifiées par les agriculteurs
No full textThe concept of “ecological network” comes from landscape ecology. It refers to reservoirs of biodiversity connected through corridors. The “Trame verte et bleue” (greenway) is an application of this ecological continuity concept in the French public policies. The “Trame verte et bleue” conveys different representations than those of the farmers. For them, more than corridors, hedges are viewed as barriers to the wind, prevent people and animals from moving, and require trees to be pruned. But hedges, as natural resources, are also come under intimate experience, and involve past generations and actors of the territory. Even though management approaches of farmers, city-dwellers and nature managers converge in mapping and categorizing natural resources, we advocate for a relational approach. This approach allows to recognize the diversity of forms those resources are qualified and managed.Issu de l’écologie du paysage, le concept de réseau écologique reliant des réservoirs de biodiversité par des corridors s’est traduit par la politique publique de trame verte et bleue. La notion de continuité écologique se heurte aux pratiques et représentations des agriculteurs. Ainsi, les haies ne sont-elles pas des corridors, mais des barrières au vent, à la circulation des bêtes ou des machines, avec des arbres qu’il faut tailler et entretenir. Les ressources naturelles cristallisent aussi un rapport à l’intime, aux générations passées et aux autres acteurs du territoire. Bien qu’agriculteurs, citadins et gestionnaires de la nature se rejoignent dans une approche gestionnaire qui cartographie et catégorise les ressources naturelles, nous suggérons de les inscrire dans une approche relationnelle permettant de reconnaître la diversité des formes de qualification et de gestion de celles-ci
Porter un autre regard sur l'exploitation, le projet de l'éleveur et son environnement avec la notion de "durabilité sociale"
No full textInternational audienceCe livrable du projet Cas Dar SOCIEL illustre, par un exemple concret, comment l’analyse systémique d’un entretien avec l’éleveur permet d’évaluer la durabilité sociale en élevage. Cette approche vise à comprendre, à travers des témoignages spontanés, et les attitudes et expériences qu’ils révèlent, les cohérences mais aussi les tensions et les arrangements, ou les combinaisons, entre les objectifs de l’éleveur et ce qu’il a entrepris, ses projets
Date fruit ( Phoenix dactylifera L.): An underutilized food seeking industrial valorization
No full textInternational audienceBackgroundThe fruit of the date palm (Phoenix dactylifera L.) is one of the most abundant fruits in the world. Hundreds of varieties having different texture, color, and flavor are available for valorization and adoption in food processing operations. Such utilization should be based on the fruit valuable characteristics; mainly its richness in dietary fiber and phenolic antioxidants.Scope and approachThis review article complements these existing reviews by primarily addressing the chemistry and processing of date fruits pulp and seeds with particular emphasis on dietary fiber and antioxidants as linked to important fruit processing and utilization features.Key findings and conclusionsDate fruits contain 6.5–11.5% total dietary fibers (of which 84–94% insoluble and 6–16% soluble dietary fiber) and is very rich in phenolic antioxidants (1–2%) especially condensed tannin pigments based on (−)-epicatechin oligomers. Date seeds contain about 15% of fiber, characterized by a high level of water-insoluble mannan fibers. Date fruits are widely available in the global market, mainly at mature Tamr stage, but there is still room for improvement. It has been suggested that date fruits and seeds can be exploited in some food applications utilizing their high levels of fiber and antioxidants. The incorporation of date fruits and seeds as food ingredients is still growing with the aim to promote the presence of dates in the modern's consumer shopping basket
