Land use and agriculture sustainability: does landscape matter?

In this paper, we focus on showing how landscape can play a role in the sustainability of agricultural activities and what conditions have to be required to consider landscape as a sustainable output in this way. Nowadays, agricultural policies in Europe attach a growing importance to the direct management by agricultural producers of the countryside. This actual trend emphasizes the role of non-commodity outputs in the production process, with respect to the multifunctional nature of agriculture. If the traditional function of the agricultural production process is to provide food, new functions of agriculture are taken into account and reveal the different attributes of land (use and non use values): agriculture may also produce rural amenities (hunting?), landscape, ecological services and habitat for wildlife, biodiversity. Here, a special emphasis is put on landscape. If several definitions exist (a non-market output, a public good, a positive externality of production, a joint production), all are concerned with the fact that landscape and other agricultural outputs are complements: they are often jointly produced. Our analysis is supported by the Georgescu-Roegen?s approach on funds and flows. Here, the dynamic property of landscape implies to consider it as a flow. An analytical representation of the agricultural production process lies upon two types of production factors: the funds -human labour, land and manufactured capital- and the flows -energy, natural resources, materials, pollution, waste and products (goods, landscape, amenities?)-. Funds and flows have the property to be complement in the process. In order to lay emphasis on the physical links between the agricultural production process and the natural environment, we follow a bioeconomic approach where the value of landscape can be appreciated through its physical foundations. According to the second law of thermodynamics, the sustainability of a production process depends upon the quality of all its flow components (inflows and outflows) during a period of time. Thus, the sustainability of any agricultural activity can be measured through the qualitative variation of the production process, i.e. through two major outflows: the waste production and the landscape production. On one hand, every time waste is produced, the irreversibility of the activity is growing and the style of farming is less sustainable (e.g. case of intensive farming). On the other hand, a growing production of landscape traduces an ability to reduce the irreversibility of the production process insofar as it is leading to more biodiversity. A relation between the level of sustainability of any agricultural production process and the landscape change in time may be established and may provide some useful guidelines for policy makers.

Toward Partial Reorientation of Land Management for Sustainability in View of Material Circulation: Biophysical and Historical Analysis

This paper explores two major issues, from biophysical and historical viewpoints. We examine land management, which we define as the long-term fertility maintenance of land in relation to agriculture, fishery and forestry. We also explore humans’ positive role as agents aiming to reinforce harmonious materials circulation within the land. Liebig’s view on nature, agriculture and land, emphasizes the maintenance of long-term land fertility based on his agronomical thought that the circulation of matter in agricultural fields must be maintained with manure as much as possible. The thoughts of several classical economists, on nature, agriculture and land are reassessed from Liebig’s view point. Then, the land management problem is discussed at a much more fundamental level, to understand the necessary conditions for life in relation to land management. This point is analyzed in terms of two mechanisms: entropy disposal on the earth, and material circulation against gravitational field. Finally from the historical example of the metropolis of Edo, it is shown that there is yet another necessary condition for the sustainable management of land based on the creation of harmonious material cycles among cities, farm land, forests and surrounding sea areas in which humans play a vital role as agent.land management, material circulation, sustainability, Liebig, Edo

Toward partial reorientation of land management for sustainability in view of material circulation : biophysical and historical analysis

This paper explores two major issues, from biophysical and historical viewpoints. We examine land management, which we define as the long-term fertility maintenance of land in relation to agriculture, fishery and forestry. We also explore humans' positive role as agents aiming to reinforce harmonious materials circulation within the land. Liebig's view on nature, agriculture and land, emphasizes the maintenance of long-term land fertility based on his agronomical thought that the circulation of matter in agricultural fields must be maintained with manure as much as possible. The thoughts of several classical economists, on nature, agriculture and land are reassessed from Liebig's view point. Then, the land management problem is discussed at a much more fundamental level, to understand the necessary conditions for life in relation to land management. This point is analyzed in terms of two mechanisms: entropy disposal on the earth, and material circulation against gravitational field. Finally from the historical example of the metropolis of Edo, it is shown that there is yet another necessary condition for the sustainable management of land based on the creation of harmonious material cycles among cities, farm land, forests and surrounding sea areas in which humans play a vital role as agent

Intergenerational justice and environmental issues. What about discounting? (In French)

The aim of this paper is to explore the connections between the time dimension of economic phenomena and that of natural ones within the context of global (joint emissions of the energy sector) or local (joint product of waste) pollutions affecting present and future generations. Discounting constitutes a first way but leads to some difficulties when fairness must be taken into account. Furthermore, to take into account the interdependencies between economics and natural environment involves irreversibility of time. At last, ethics which is a key dimension of the sustainable development is introduced with Jonas’s responsibility principle. In this way, discounting can be used under some limits regarding economic decisions.intergenerational equity; discounting; responsibility principle; irreversibility; sustainable development

Étude économique des ressources énergétiques dans le cadre d'une approche globale intégrant l'environnement

Le système énergétique perturbe fortement les équilibres de la biosphère. A la lumière des enseignements des principes de la thermodynamique et écologiques, le système énergétique apparait comme un système ouvert. Il puise dans l'environnement des ressources organisées-de basse entropie- et libère des déchets -éléments inorganisés de haute entropie. Cela implique un accroissement irréversible de l'entropie de l'environnement naturel. Cependant, la maitrise de l'évolution entropique est possible s'il quitte le sentier d'évolution sur lequel il est localisé et s'achemine vers un sentier d'évolution flexible assurant la pérennité du patrimoine du patrimoine énergétique pour les générations futures ainsi qu'une véritable coévolution.The energetic system deeply disturbs biosphere equilibriums. Drawing a lesson from thermodynamic and ecological principles, the energetic system appears as an open system. It draws organized resources -of low entropy- from the environment and releases wastes -disorganized elements of high entropy. Consequently, it implies an irreversible increase of natural environment entropy. However, the control of the entropic evolution is possible if it gives up the evolution path on which it stands, and to be on its way towards a real coevolution and a flexible evolution path ensuring the perenniality of energetic patrimony for the future generations

IL-21 promotes survival and maintains a naive phenotype in human CD4+ T lymphocytes

IL-21 is a key T-cell growth factor (TCGF) involved in innate and adaptive immune response. It contributes to the proliferation of naive, but not memory T lymphocytes. However, the full spectrum of IL-21 activity on T cells remains unclear. Here, we demonstrate that IL-21 primarily maintains the expression of specific naive cell surface markers such as CD45RA, CD27, CD62L and CCR7 on human CD4+ T lymphocytes and that the expression of CCR7 induces cell migration by means of CCL21 chemoattraction. These effects contrast with those of IL-2 which induced the marked proliferation of CD4+ T lymphocytes, leading to an activated-memory phenotype. Nevertheless, IL-21 maintained cell cycle activation and expression of proliferation markers, including proliferating cell nuclear antigen and Ki-67, and triggered T-cell proliferation via TCR and co-stimulation pathways. Unlike IL-2, IL-21 decreased the expression of the anti-apoptotic Bcl-2 protein, which correlated with the absence of activation of the phosphatidylinositol 3′-kinase/Akt signaling pathway. Thus, IL-21 is a TCGF whose function is the preservation of a pool of CD4+ T lymphocytes in a naive phenotype, with a low proliferation rate but with the persistence of cell cycling proteins and cell surface expression of CCR7. These findings strongly suggest that IL-21 plays a part in innate and adaptive immune response owing to homeostasis of T cells and their homing to secondary lymphoid organ

Justice environnementale, justice alimentaire et OGM. Analyse à partir de l’agriculture indienne

Depuis une quinzaine d’années, le débat sur les Organismes génétiquement modifiés (OGM) a pris une ampleur considérable en s’appuyant sur des mouvements protestataires. L’originalité de ces protestations est d’associer la justice environnementale et la justice alimentaire. Cet article examine la façon dont ces deux notions s’articulent dans le contexte de l’agriculture indienne. Trois cas d’études, dont les problématiques ont émergé successivement, sont mobilisés pour montrer l’évolution des argumentaires développés par les mouvements protestataires. Ces exemples permettent de mettre en lumière la force des discours récents, qui amènent à revoir en profondeur le concept de justice environnementale pour intégrer celui de justice alimentaire. Par ailleurs, les auteurs montrent que le discours a connu un changement en passant d’arguments en faveur du maintien des traditions culturelles à des arguments soulignant les externalités négatives des OGM.For fifteen years, the debate on GMOs (Genetically Modified Organisms) has grown considerably in India. The originality of the movements of protestation is to combine environmental justice and food justice. This article examines how these two concepts are articulated in the context of Indian agriculture. Three case studies, which have emerged successively, are mobilised to show the evolution of the arguments developed. These examples highlight the strength of the recent speeches that lead to modify the concept of environmental justice to include the food justice. Furthermore, the authors show the speech known a change, starting with arguments related to the preservation of cultural traditions to arguments stressing the negative externalities of GMOs

Introducing Environmental Ethics into Economic Analysis: Some insights from Hans Jonas’ Imperative of Responsibility

This paper analyses how Hans Jonas’ Imperative of Responsibility may provide useful insights into the analysis of sustainability issues. The challenges of environmental and social sustainability in terms of inter-generational fairness are analysed and involve a moral duty that is applicable to economic governance. To what extent responsibility is an alternative to utilitarianism and as a principle facilitating the coordination of the agents involved? Exploring this question may be a first step towards the long-term and sustainable conservation of Nature

The proinflammatory cytokines IL-2, IL-15 and IL-21 modulate the repertoire of mature human natural killer cell receptors

Natural killer (NK) cells play a crucial role in the immune response to micro-organisms and tumours. Recent evidence suggests that NK cells also regulate the adaptive T-cell response and that it might be possible to exploit this ability to eliminate autoreactive T cells in autoimmune disease and alloreactive T cells in transplantation. Mature NK cells consist of a highly diverse population of cells that expresses different receptors to facilitate recognition of diseased cells and possibly pathogens themselves. Ex vivo culture of NK cells with cytokines such as IL-2 and IL-15 is an approach that permits significant expansion of the NK cell subpopulations, which are likely to have potent antitumour, antiviral, or immunomodulatory effects in autoimmunity. Our data indicate that the addition of IL-21 has a synergistic effect by increasing the numbers of NK cells on a large scale. IL-2 and IL-15 may induce the expression of killer cell immunoglobulin-like receptors (KIRs) in KIR-negative populations, the c-lectin receptor NKG2D and the natural cytotoxic receptor NKp44. The addition of IL-21 to IL-15 or IL-2 can modify the pattern of the KIR receptors and inhibit NKp44 expression by reducing the expression of the adaptor DAP-12. IL-21 also preserved the production of interferon-γ and enhanced the cytotoxic properties of NK cells. Our findings indicate that the proinflammatory cytokines IL-2, IL-15 and IL-21 can modify the peripheral repertoire of NK cells. These properties may be used to endow subpopulations of NK cells with specific phenotypes, which may be used in ex vivo cellular immunotherapy strategies

L’ANTHROPOCENE COMME RUPTURE DE L’HISTOIRE DE L’ECONOMIE

Si le passage à l’Anthropocène révèle la capacité de l’homme à transformer l’ensemble du système terrestre, les théories économiques ont de tout temps, minimisé ce changement d’époque géologique, préférant focaliser leur attention sur la dynamique du système capitaliste ou la sacro-sainte croissance économique. Si des limites à la croissance sont bien mentionnées, elles restent cantonnées à des contraintes socio-techniques (pénurie de main d'œuvre, coût élevé du capital, prix des matières premières, faiblesse des investissements, absence de prise de risques des entrepreneurs…). Tout laisse à penser que les sociétés, par essence économiques, se seraient libérées des limites biophysiques. L’Anthropocène montre au contraire que ces limites imposent un réencastrement de l’économie dans l’environnement et dans le social. La question du temps, souvent réduite au court terme et à des questions de statique ou de dynamique dans la théorie économique, impose de penser l’avenir, sans pour autant reposer sur une extrapolation du passé. Dès lors, les théories économiques doivent proposer un corpus d’hypothèses et de concepts susceptibles de forger de nouveaux paradigmes, plus à même de se représenter les futurs possible