Les circuits marchands des riz en Guinée : les évolutions de 1989 à 1997

Cette étude, associée au Pnasa, avait pour objectif de suivre les différentes formes d'un commerce en pleine explosion, Réalisées annuellement, depuis 1989, 1200 enquêtes ont été réparties auprès des acteurs de la filière rizicole. L'ancien système de collecte était constitué de multiples espaces d'échanges, contrôlés par des commerçants assis au centre des régions de production. La réouverture des marchés périodiques et l'amélioration des transports a provoqué un essor des échanges sur des par marchés de riz local où se sont rencontré producteurs et petits collecteurs. Le commerce du riz importé a entraîné des échanges reliant la majorité des régions. Les riz importés ont conquis les marchés intérieurs, les importateurs de la confrérie de Madina ont bénéficié de leur réseau de distribution. Par la suite, le marché des importations a évolué rapidement et s'est concentré. L'essor des importations de riz a eu pour conséquence la déstabilisation de la production rizicole de l'Ouest de la Guinée. Les importateurs de la confrérie de Madina n'ont pu se maintenir comme importateurs, mais sont devenus des grossistes des denrées importées dans la région NordOuest, en Guinée maritime où se rencontrent les producteurs et les petits collecteurs. En 1997, le riz local a conquis de nouveaux marchés ; l'enjeu est maintenant de favoriser cette extension. Les efforts pour fluidifier les échanges ont facilité les contacts entre les producteurs et les commerçants, stimulant l'accroissement des surfaces mises en culture. (Résumé d'auteur

Savoirs techniques locaux, sources d'innovations ? Production de savoirs actionnables dans une démarche de recherche action en partenariat

International audienceFace aux défis auxquels l'Afrique de l'Ouest est confrontée pour son développement, les savoirs techniques locaux peuvent-ils être des sources de connaissance pour l'innovation ? Traditionnellement, les pratiques d'un groupe social sont réglées sur un long terme par les savoirs locaux jusqu'à l'avènement de problèmes inhabituels. Dans chaque nouvelle situation problématique, le retour à la maîtrise technique passe par l'acquisition de nouveaux savoirs et l'apprentissage de nouvelles pratiques, le tout s'inscrivant dans un processus d'innovation. Les démarches de recherche action en partenariat, visant à résoudre les problèmes vécus par les acteurs de terrain, requièrent la production de références actionnable. Dans ce cadre, les savoirs techniques locaux peuvent favoriser l'innovation s'ils sont réellement pris en compte. Nous proposons que dans les diagnostics, ils soient intégrés dans l'analyse des pratiques et de leurs fondements, et que dans la mise en œuvre des solutions et la conception des innovations, ils soient coalisés aux savoirs exogènes mobilisés. Cette thèse sera illustrée par des travaux de recherche en partenariat conduits, dans les villages de Koumbia et de Waly (ouest du Burkina Faso) visant la conception et la mise en œuvre d'innovations sur les pratiques de conduite des troupeaux au pâturage (élaboration de nouvelles règles) et de gestion de la fertilité des sols avec des fumures organiques (diversification et amélioration de la production)

Response of stratospheric water vapor and ozone to the unusual timing of El Niño and the QBO disruption in 2015–2016

The stratospheric circulation determines the transport and lifetime of key trace gases in a changing climate, including water vapor and ozone, which radiatively impact surface climate. The unusually warm El Niño–Southern Oscillation (ENSO) event aligned with a disrupted Quasi-Biennial Oscillation (QBO) caused an unprecedented perturbation to this circulation in 2015–2016. Here, we quantify the impact of the alignment of these two phenomena in 2015–2016 on lower stratospheric water vapor and ozone from satellite observations. We show that the warm ENSO event substantially increased water vapor and decreased ozone in the tropical lower stratosphere. The QBO disruption significantly decreased global lower stratospheric water vapor and tropical ozone from early spring to late autumn. Thus, this QBO disruption reversed the lower stratosphere moistening triggered by the alignment of the warm ENSO event with westerly QBO in early boreal winter. Our results suggest that the interplay of ENSO events and QBO phases will be crucial for the distributions of radiatively active trace gases in a changing future climate, when increasing El Niño-like conditions and a decreasing lower stratospheric QBO amplitude are expected

A “reverse pharmacology” approach for developing an anti-malarial phytomedicine

A "reverse pharmacology" approach to developing an anti-malarial phytomedicine was designed and implemented in Mali, resulting in a new standardized herbal anti-malarial after six years of research. The first step was to select a remedy for development, through a retrospective treatment-outcome study. The second step was a dose-escalating clinical trial that showed a dose-response phenomenon and helped select the safest and most efficacious dose. The third step was a randomized controlled trial to compare the phytomedicine to the standard first-line treatment. The last step was to identify active compounds which can be used as markers for standardization and quality control. This example of "reverse pharmacology" shows that a standardized phytomedicine can be developed faster and more cheaply than conventional drugs. Even if both approaches are not fully comparable, their efficiency in terms of public health and their complementarity should be thoroughly considered

Conceptual Requirements for Command and Control Languages

Simulation Interoperability Standards Organization (SISO) SIW Conference PaperThe current Coalition Battle Management Language initiative (C-BML) will define a language to unambiguously exchange command and control information between systems. This paper introduces a categorization that may be used to guide the process of developing C-BML effectively by enumerating the conceptual requirements the authors have identified in model-based data engineering and process engineering based studies in various domains

Correction of Craniofacial Deficits using Epigallocatechin-3’-gallate Treatment in a Down Syndrome Mouse Model

poster abstractDown syndrome (DS) is caused by trisomy of human chromosome (HSA21). Individuals with DS display distinct craniofacial abnormalities including an undersized, dismorphic mandible which leads to difficulty with eating, breathing, and swallowing. Using the Ts65Dn DS mouse model (three copies of ~50% HSA21 homologs), we have traced the mandibular deficit to a neural crest cell (NCC) deficiency and reduction in first pharyngeal arch (PA1 or mandibular precursor) at embryonic day 9.5. Previous studies have shown that this deficit is caused when NCC fail to migrate from the neural tube to populate the PA1 and fail to proliferate in the PA1. At E9.5, Dyrk1A, a triplicated DS candidate gene, is overexpressed in the PA1 and may cause the NCC and PA1 deficits. We hypothesize that treatment of pregnant Ts65Dn mothers with Epigallocatechin-3’-gallate (EGCG), a known Dyrk1A inhibitor, will correct NCC deficits and rescue the undersized PA1 in trisomic E9.5 embryos. To test our hypothesis, we treated pregnant Ts65Dn mothers with EGCG, where embryos received treatment from either E7-E8 or E0-E9.5. Our preliminary study found variable increases in PA1 volume and NCC number between treatment regimens, with several treatment groups indicating EGCG treatment has the potential to rescue the NCC deficit in the mandibular precursor. We found an increase in NCC number and PA1 volume with E7-E8 EGCG treatment in 21-24 somite embryos from trisomic mothers and in euploid embryos from euploid mothers treated from E0-E9.5. With EGCG treatment, we also observed a decrease in the average somite number of embryos from trisomic mothers, but an increase in those mothers’ average litter size. This study is important because it helps define the specific dosage and timing of ECGC and how it may affect specific DS phenotypes. These findings provide preclinical testing for a potential therapy for craniofacial disorders linked to DS

JuSER – Volltextrepositorium und mehr

1.5 minutes of madness: Kurzvorstellung des Posters zu JuSE

Argemone mexicana decoction versus artesunate-amodiaquine for the management of malaria in Mali: Policy and public-health implications

A classic way of delaying drug resistance is to use an alternative when possible. We tested the malaria treatment Argemone mexicana decoction (AM), a validated self-prepared traditional medicine made with one widely available plant and safe across wide dose variations. In an attempt to reflect the real situation in the home-based management of malaria in a remote Malian village, 301 patients with presumed uncomplicated malaria (median age 5 years) were randomly assigned to receive AM or artesunate-amodiaquine [artemisinin combination therapy (ACT)] as first-line treatment. Both treatments were well tolerated. Over 28 days, second-line treatment was not required for 89% (95% CI 84.1-93.2) of patients on AM, versus 95% (95% CI 88.8-98.3) on ACT. Deterioration to severe malaria was 1.9% in both groups in children aged ≤5 years (there were no cases in patients aged >5 years) and 0% had coma/convulsions. AM, now government-approved in Mali, could be tested as a first-line complement to standard modern drugs in high-transmission areas, in order to reduce the drug pressure for development of resistance to ACT, in the management of malaria. In view of the low rate of severe malaria and good tolerability, AM may also constitute a first-aid treatment when access to other antimalarials is delaye