143 research outputs found
LA QUALITE, LA QUALIFICATION ET L'ACTION COLLECTIVE DANS LES PROCESSUS D'INNOVATION ET D'ACTIVATION DES SYAL LE CAS DES FROMAGERIES RURALES EN AMERIQUE LATINE
N° ISBN - 978-2-7380-1284-5International audienceSince the late nineties in Latin America, a new way of Rural Agro-Industry (RAI) development has been opened with Localized Agri-food Systems (SYAL in French). It appeared from existing relationships between geographical concentrations of RAI and the territory and with the idea of coping with new challenges brought about by globalization. This perspective is particularly relevant in the dairy and cheese dairy sectors. The main objective of this paper is to present an analysis of cheese dairy Localized Agri-food Systems activation, based on various case studies in Latin America that were presented during a workshop held in Toluca, Mexico, in November 2009. We highlight the necessary conditions to land resources activation in the strategies of local development based on the relationship between the territory and food products. In particular, we try to show that the various forms of the articulation between territory and value chain on the one hand, and the constitution of external or internal social networks on the other hand, largely determine the modality of collective actions and their results. In the specific case of milk that we are dealing with, it appears that the basis of local development process rests on the co-construction of a territorialized resource connected with quality and know-haw, such as collective trademarks, registered designation of origin and geographical indication of origin
Céréaliculture commerciale et concentration foncière
Depuis le début des années 1990, l’agriculture mexicaine connaît de profondes restructurations qui s’inscrivent dans un ensemble de réformes visant à accélérer l’insertion compétitive des exploitations sur les marchés agricoles, notamment dans le cadre de l’Accord de libre-échange nord-américain liant le Mexique, les États-Unis et le Canada depuis le 1er janvier 1994. Dans le domaine foncier, la révision, en 1991, de l’article 27 de la Constitution mexicaine a signifié la fin des redistributions foncières – à l’origine de la formation des ejidos –, et la réintégration aux marchés fonciers des terres distribuées dans le cadre de la réforme agraire (autorisation de leur cession définitive et/ou temporaire et de leur mise en gage). En instaurant par ailleurs un cadre institutionnel propice à l’émergence de marchés fonciers dans les ejidos via un important programme de titrage individuel des droits fonciers, la réforme devait contribuer à la mise en place de nouvelles dynamiques productives, en forçant la réallocation des ressources productives, notamment la terre, vers les structures les plus compétitives. Les concentrations foncières aux mains des plus « productifs » sont donc désormais possibles et même souhaitées, et cela, en totale contradiction avec le Code agraire qui interdit toujours la grande propriété au Mexique. Les questions foncières liées aux transformations productives et au changement institutionnel sont traitées ici à partir d’une étude de cas conduite dans différents ejidos des terres basses du Sud-Veracruz (bassins du Tesechoacan et du Moyen-Coatzacoalcos), où l’on observe depuis le milieu des années 1990 un développement important de la production mécanisée de maïs et de sorgho destinée aux marchés. Il s’agit notamment, après la révision constitutionnelle de 1991, de dresser un état des lieux des dynamiques foncières liées à la diffusion de la céréaliculture commerciale, lesquelles se manifestent par un accroissement marqué de la demande sur les marchés fonciers internes et externes aux ejidos. Il s’agit aussi de montrer comment l’accès des petits producteurs aux différentes ressources productives (terre, intrants et capital technique) s’organise aujourd’hui à différentes échelles, au sein des ejidos d’une part, mais également autour de l’intervention de nouveaux acteurs issus du secteur privé (agro-industriels, entrepreneurs et opérateurs agricoles, fournisseurs d’intrants et de services, etc.). Que ces derniers prennent part ou non à un récent phénomène d’acquisitions foncières – qui n’a toutefois ni l’ampleur ni les caractéristiques des grandes appropriations foncières ayant actuellement lieu dans certains pays du Sud –, ils jouent un rôle de plus en plus central dans les stratégies d’expansion des petites exploitations familiales et dans les processus locaux d’intégration commerciale. Dans le cas du bassin du Tesechoacan, le modèle d’intégration impulsé par les acteurs privés s’apparente à une forme d’agriculture sous contrat (sur le modèle développé par l’agrobusiness), tandis que dans celui du Moyen-Coatzacoalcos, le schéma fonctionne avant tout sur la base de relations personnalisées de type clientéliste. Dans les deux cas toutefois, les logiques d’intervention de ces nouveaux acteurs privés s’appuient sur un contrôle accru des exploitations familiales, tant en amont (accès aux ressources productives) qu’en aval (mise en marché) de la production. Par ailleurs, la présence du secteur privé bénéficie en premier lieu à une catégorie émergente d’ejidataires « capitalisés », dont le rapprochement avec ces nouveaux acteurs se construit autour de la prise de terres en location. L’une des conséquences est une différenciation socio-économique accélérée au sein des ejidos. Au final, l’analyse des processus productifs en cours dans les terres basses du Sud-Veracruz permet de mettre en évidence une tendance à l’accumulation et à la concentration de terres, aux mains d’une catégorie minoritaire d’ejidataires bien dotés en capital technique d’une part, et d’entrepreneurs privés contrôlant les accès aux ressources productives et aux marchés d’autre part.Since the early 1990s, Mexican agriculture has undergone major restructuration as part of reforms aiming to help the country’s farms take their place on agricultural markets. This is especially true with respect to the North American Free Trade Agreement, signed on 1 January 1994 by the United States, Canada and Mexico. As far as land is concerned, Article 27 of the Mexican Constitution was revised in 1991 to put a stop to land redistributions, linked to the creation of ejidos, and reintegrate land distributed as a result of the agrarian reform into property markets (in particular, it authorised permanent and temporary land transfers and using land as collateral). In addition, the reform introduced a new system of land title to ejidos in order to encourage emerging property markets. This was to support new forms of productivity by forcing the reallocation of productive resources (land in particular) to more competitive structures. Allowing the most productive to amass land was now possible and even desirable, despite contradictory provisions prohibiting large estates in the Agrarian Code. This study focuses on land issues linked to productive transformations and institutional change by observing several ejidos in the south Veracruz lowlands (the Tesechoacan River basin and middle reaches of the Coatzacoalcos River). Since the mid 1990s, mechanised production of corn and sorghum crops for the market has increased considerably. The study will examine the changes affecting land following the 1991 constitutional revision and the spread of commercial grain farming. In particular, the study will look into the increase in demand for land inside and outside ejidos. It will also show how small producers’ access to productive resources (land, inputs and technical capital) is organised on several levels – within ejidos, but also with new private sector actors (industrial farmers, companies, agricultural operators, and input and service suppliers, etc.). Whether or not the latter take part in the recent trend of land acquisitions – on a much smaller scale than the large-scale land acquisitions taking place in other developing countries – they play an increasingly important role in the expansion strategies of small family farms and local commercial integration processes. In the Tesechoacan basin, the integration model pushed by private sector actors resembles a form of contract farming (based on the agribusiness model). In the middle Coatzacoalcos River, it operates via a clientelistic system of personal relationships. However, in both cases, these new private sector actors intervene to increase their control over family farms, both upstream (by controlling productive resources) and downstream (by getting produce to market). Moreover, the presence of the private sector benefits a new category of “capitalised” ejidatarios, who build relationships based on renting land. Consequently, there are growing socio-economic differences between ejidos. Finally, by analysing the productive processes at work in the south Veracruz lowlands, the study highlights the increasing accumulation and concentration of land by two groups: ejidatarios with significant technical capital on the one hand, and private entrepreneurs controlling access to productive resources and the market on the other
Secteur privé et céréaliculture familiale dans le Mexique du libre-échange
Au Mexique, l’ouverture commerciale et la libéralisation des marchés agricoles posent la question du devenir de l’agriculture paysanne et de son insertion compétitive sur les marchés. Cette question est traitée ici à partir d’une étude de cas dans des ejidos du sud-Veracruz, où l’intensification récente des systèmes de production céréaliers s’est accompagnée d’un processus d’intégration marchande des exploitations piloté par le secteur privé. Il s’agit de rendre compte des mécanismes ayant permis le passage de systèmes largement tournés vers l’autoconsommation à des systèmes intensifs à vocation commerciale, en insistant sur les rôles majeurs joués par l’État dans l’incitation au rapprochement des petits producteurs avec le secteur privé. L’analyse s’appuie sur des enquêtes réalisées dans les ejidos des terres basses du fleuve Tesechoacan, à proximité de la ville d’Isla. La dynamique d’évolution des systèmes de production est analysée de façon croisée avec les changements intervenus dans le domaine de l’intervention publique d’une part, et les transformations institutionnelles qui l’ont accompagnée d’autre part (organisation paysanne, intégration marchande).In Mexico, trade liberalization and privatization reforms in agricultural sector question the future of small-scale farmers and their competitive market integration. Dealing with this issue, this article presents the case study of ejido communities located in the south of Veracruz state, where the recent intensification of maize-based productive systems resulted in a market integration of small-scale farmers in which private sector played a major role. This work exposes the mechanisms and the way subsistence systems shifted towards intensive commercial systems, stressing the major role of the State to encourage the linking of small farmers with private sector. This analysis relies on field investigations performed in ejido communities located in Tesechoacan river’s lowlands near the city of Isla. The dynamics of the evolution of maize-based productive systems is analyzed in a crossed way with changes of public intervention conditions in agricultural sector, also with institutional transformations that have accompanied this process (peasant organization, market integration). (JEL: O13, O33
SYAL : UN NOUVEL OUTIL POUR LE DEVELOPPEMENT DE TERRITOIRES MARGINAUX. LES LEÇONS DE L'ALLIANCE DES AGRO-INDUSTRIES RURALES DE LA SELVA LACANDONA, CHIAPAS.
N° ISBN - 978-2-7380-1284-5International audienceSince its beginnings in the eighties, Rural Agro-Industry (RAI) has emerged as an effective way to fight against poverty in marginalized rural areas, because of its ability to contribute to the overall improvement of small producers' living conditions. This development tool has been completed in the nineties by the Localized Agri-food Systems concept (SYAL in French) and the process of their activation. From the experience of a RAI development project promoted in the Selva Lacandona (Chiapas, Mexico), we present some lessons learned from this development project. One of the principal results was to identify and define the conditions of RAI sustainability in the Selva Lacandona. If economics profitability of the micro-enterprises proved to be essential to ensure their viability, it does not seem central as it doesn't represent a real problem. On the other hand, two aspects appeared to be fundamental to guarantee the RAI sustainable development in such marginalized region: the necessity of a prior favorable environment, in particular trough the presence of functional local public goods, and the resolution of organization and leadership problems
Characterisation of RT1-E2, a multigenic family of highly conserved rat non-classical MHC class I molecules initially identified in cells from immunoprivileged sites
BACKGROUND: So-called "immunoprivileged sites" are tissues or organs where slow allograft rejection correlates with low levels of expression of MHC class I molecules. Whilst classical class I molecules are recognised by cytotoxic T lymphocytes (CTL), some MHC class I molecules are called "non-classical" because they exhibit low polymorphism and are not widely expressed. These last years, several studies have shown that these can play different, more specialised roles than their classical counterparts. In the course of efforts to characterise MHC class I expression in rat cells obtained from immunoprivileged sites such as the central nervous system or the placenta, a new family of non-classical MHC class I molecules, which we have named RT1-E2, has been uncovered. RESULTS: Members of the RT1-E2 family are all highly homologous to one another, and the number of RT1-E2 loci varies from one to four per MHC haplotype among the six rat strains studied so far, with some loci predicted to give rise to soluble molecules. The RT1(n )MHC haplotype (found in BN rats) carries a single RT1-E2 locus, which lies in the RT1-C/E region of the MHC and displays the typical exon-intron organisation and promoter features seen in other rat MHC class I genes. We present evidence that: i) RT1-E2 molecules can be detected at the surface of transfected mouse L cells and simian COS-7 cells, albeit at low levels; ii) their transport to the cell surface is dependent on a functional TAP transporter. In L cells, their transport is also hindered by protease inhibitors, brefeldin A and monensin. CONCLUSIONS: These findings suggest that RT1-E2 molecules probably associate with ligands of peptidic nature. The high homology between the RT1-E2 molecules isolated from divergent rat MHC haplotypes is particularly striking at the level of their extra-cellular portions. Compared to other class I molecules, this suggests that RT1-E2 molecules may associate with well defined sets of ligands. Several characteristics point to a certain similarity to the mouse H2-Qa2 and human HLA-G molecules
Hydraulic and thermal impact modelling at the scale of the geothermal heating doublet in the Paris Basin, France
13 pagesInternational audienceThe Paris Basin is extensively developed for the geothermal district heating (GDH) of approximately 150 000 dwellings. As of late 2010, thirty four GDH systems apply the doublet concept in the Paris suburban area and mine the heat of the Dogger reservoir, a limestone formation of Mid-Jurassic age at depths ranging from 1500 to 2000 m. As the brine is fully reinjected, cold water bodies progressively invade the reservoir around injector wells inducing both thermal and hydraulic interactions at the doublet scale. The premature production well cooling and the sustainable development of the resource highlight two critical parameters, the thermal breakthrough time (tB) and the extent of the cooled fluid bubble(S) respectively. First, a set of benchtest simulations was launched to compare the sensitivities of tB and S parameters to selected reservoir conceptual model typologies. These simulations were applied on a GDH doublet undergoing a suspected thermal breakthrough. Five reservoir modelling teams validated their “in house” simulations by (i) checking an analytical (Gringarten-Sauty, 1979) solution, and (ii) testing three candidate reservoir structures on the doublet considered remotely located (i.e. not interfering with nearby exploitations) for a first step. The outcome resulted in a rewarding insight into the variability of simulation outputs. An additional segment will enable the actors to compare their modelling expertise on the same doublet considered in interaction with the other GDH operations located in its environment. Second, BRGM carried out a survey towards various rehabilitation schemes (a new doublet or a triplet) and their contribution toward sustainability standards. From a hypothetical, twenty five year life, doublet simulation, an initial hydraulic/temperature field was derived. Then, several new well locations were simulated and isotherms, alongside production well cooling kinetics, compared accordingly. A two-stage rehabilitation scheme, i.e. triplet then a new doublet, seems to reconcile the resource longevity and the economic demand. Further work is required to compare the different designs with a method integrating both the impact of the geothermal exploitation on the resource and the lifetime of the exploitation in a single mathematical factor
Ab initio study of bilateral doping within the MoS2-NbS2 system
We present a systematic study on the stability and the structural and
electronic properties of mixed molybdenum-niobium disulphides. Using density
functional theory we investigate bilateral doping with up to 25 % of MoS2
(NbS2) by Nb (Mo) atoms, focusing on the precise arrangement of dopants within
the host lattices. We find that over the whole range of considered
concentrations, Nb doping of MoS2 occurs through a substitutional mechanism.
For Mo in NbS2 both interstitial and substitutional doping can co-exist,
depending upon the particular synthesis conditions. The analysis of the
structural and electronic modifications of the perfect bulk systems due to the
doping is presented. We show that substitutional Nb atoms introduce electron
holes to the MoS2, leading to a semiconductor-metal transition. On the other
hand, the Mo doping of Nb2, does not alter the metallic behavior of the initial
system. The results of the present study are compared with available
experimental data on mixed MoS2-NbS2 (bulk and nanoparticles).Comment: 7 pages, 6 figure
Correction: Characterisation of RT1-E2, a multigenic family of highly conserved rat non-classical MHC class I molecules initially identified in cells from immunoprivileged sites
HIV-1-infected patients from the French National Observatory experiencing virological failure while receiving enfuvirtide
Objectives We studied gp41 mutations associated with failing enfuvirtide salvage therapy. Methods This multicentre study involved patients with HIV-1 plasma viral load (pVL) > 5000 copies/mL after at least 3 months of uninterrupted enfuvirtide therapy and with plasma samples available at inclusion (T0), at initial enfuvirtide failure (T1) and at last follow-up visit during continued failing enfuvirtide therapy (T2). The HR-1 and HR-2 domains of the gp41 gene were sequenced at T0, T1 and T2. Results Ninety-nine patients were enrolled. At baseline, the median pVL and CD4 cell count were 5.1 log copies/mL and 72 cells/mm3, respectively. Based on the ANRS Resistance Group algorithm, the proportion of patients harbouring viruses with enfuvirtide resistance mutations increased significantly between T0 and T1. In the HR-1 domain, the V38A/M, Q40H, N42T, N43D and L45M mutations wereselected (P < 0.02). In the HR-2 domain, no mutations were significantly selected during the follow-up. None of the mutations was associated with a CD4 cell count increment. Conclusions Mutations selected during failing enfuvirtide salvage therapy are mainly located in the HR-1 domain of the gp41 gene, between codons 38 and 45. No mutations were associated with an increase in the CD4 cell coun
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