Encourager la transformation de l'agriculture et des systèmes alimentaires en Afrique

International Development, Downloads July 2008 - June 2009: 7,

Forum International au Sahel sur l'Éducation Environnementale

Le Comité Permanent Inter-États de Lutte contre la Sécheresse au Sahel (CILSS) a organisé en partenariat avec la Commission Européenne et à tra­vers le PFIE (Programme de Formation et d'Information sur l'Environ­nement) le Forum International au Sahel sur l'Éducation Environnemen­tale (FISEE). Venant d'horizons divers, décideurs, spécialistes, formateurs, éducateurs et élèves, hommes et femmes de la communication ont convergé au rendez-vous de « la Planète en Partage ». Le Sahel s'est fait l'..

Dynamique Spatio-temporelle de la Mangrove du bas Delta du Fleuve Sénégal de 1980 à 2021: Approche par Télédétection et Système d’Information Géographique

Le bas delta du fleuve Sénégal est une zone d’intérêt écologique au regard de la pluralité d’aires protégées qui sont localisées. Ce milieu, qui se caractérise par la diversité de ses ressources naturelles, développe une très grande vulnérabilité imputable à des causes aussi bien naturelles qu’anthropiques. Depuis quelques décennies, cette fragilité du milieu se répercute sur la mangrove qui assume difficilement ses fonctions socioéconomiques et écologiques. Dès lors, il convient d’analyser la dynamique spatiotemporelle de cet écosystème afin de comprendre les facteurs qui interviennent dans sa dégradation. Dans cette étude, l’objectif a été atteint au moyen de la télédétection à travers le traitement d’images satellitaires Landsat 1980 et 2000, Sentinel 2021 combiné à des travaux de terrains. Cela a permis la réalisation de cartes d’occupation du sol et de cartes de changements. Les résultats démontrent une tendance globale à la hausse de la mangrove avec des espaces couverts qui sont passés de 1 105,82 ha en 1980 à 1 482,32 ha en 2021 malgré une perte de superficies de 166,92 ha sur cette période.             The lower delta of the Senegal River is a zone of ecological interest with regard to the plurality of protected areas that are located. This environment, which is characterized by the diversity of natural resources, develops a very great vulnerability due to natural and anthropic causes. For several decades, this fragility of the environment has had repercussions on the mangrove, which is having difficulty fulfilling its socio-economic and ecological functions. Therefore, it is necessary to analyze the spatiotemporal dynamics of this ecosystem in order to understand the factors involved in its degradation. In this study, this objective was achieved by means of remote sensing through the processing of Landsat 1980 and 2000, Sentinel 2021 satellite images combined with field work. This allowed the realization of land use maps and change maps. The results show an overall increasing trend of the mangrove with areas covered that have increased from 1 105.82ha in 1980 to 1 482.32ha in 2021 despite a loss of area of 166.92 ha over this period

Dynamique Spatio-temporelle de la Mangrove du bas Delta du Fleuve Sénégal de 1980 à 2021: Approche par Télédétection et Système d’Information Géographique

          Le bas delta du fleuve Sénégal est une zone d’intérêt écologique au regard de la pluralité d’aires protégées qui y sont localisées. Ce milieu, qui se caractérise par la diversité de ses ressources naturelles, développe une très grande vulnérabilité imputable à des causes aussi bien naturelles qu’anthropiques. Depuis quelques décennies, cette fragilité du milieu se répercute sur la mangrove qui assume difficilement ses fonctions écologiques et socioéconomiques. Dès lors, il convient d’analyser la dynamique spatiotemporelle de cet écosystème afin de comprendre les facteurs qui interviennent dans sa dégradation. Dans cette étude, l’objectif a été atteint au moyen de la télédétection à travers le traitement d’images satellitaires Landsat 1980 et 2000, Sentinel 2021 combiné à des travaux de terrains. Cela a permis la réalisation de cartes d’occupation du sol et de cartes de changements. Les résultats démontrent une tendance globale à la hausse de la mangrove avec des espaces couverts qui sont passés de 1 105,82 ha en 1980 à 1 482,32 ha en 2021 malgré une perte de superficies de 166,92 ha sur cette période.   The lower delta of the Senegal River is a zone of ecological interest with regard to the plurality of protected areas that are located. This environment, which is characterized by the diversity of natural resources, develops a very great vulnerability due to natural and anthropic causes. For several decades, this fragility of the environment has had repercussions on the mangrove, which is having difficulty fulfilling its socio-economic and ecological functions. Therefore, it is necessary to analyze the spatiotemporal dynamics of this ecosystem in order to understand the factors involved in its degradation. In this study, this objective was achieved by means of remote sensing through the processing of Landsat 1980 and 2000, Sentinel 2021 satellite images combined with field work. This allowed the realization of land use maps and change maps. The results show an overall increasing trend of the mangrove with areas covered that have increased from 1 105.82ha in 1980 to 1 482.32ha in 2021 despite a loss of area of 166.92 ha over this period

Les institutions et les pratiques locales

ASC – Publicaties niet-programma gebonde

Refractory Hard Alloys Elaborated by Casting of Ternary (Co, Ni Fe)-30Cr-2.5 to 5 wt% C Compositions

International audienceThree series of ternary alloys of the {M-30Cr-xC}-type with M = Co, Ni or Fe and x ranging from 2.5 to 5 wt% were elaborated by casting. Their microstructure characterizations by XRD and SEM show that very high volume fractions in chromium carbides (even more than 50%) may be obtained in a metallic matrix by this way. However graphite may also appear in very low quantities in the carbon-richest alloys. The hardness increases with the carbon content (up to 1000 Hv30kg) but it may be a little lowered when graphite is also present. The results show that very hard alloys may be simply obtained by casting of rather cheap elements

Mass testing and treatment for malaria followed by weekly fever screening, testing and treatment in Northern Senegal: feasibility, cost and impact.

BACKGROUND NlmCategory: BACKGROUND content: Population-wide interventions using malaria testing and treatment might decrease the reservoir of Plasmodium falciparum infection and accelerate towards elimination. Questions remain about their effectiveness and evidence from different transmission settings is needed. - Label: METHODS NlmCategory: METHODS content: "A pilot quasi-experimental study to evaluate a package of population-wide test and treat interventions was conducted in six health facility catchment areas (HFCA) in the districts of Kanel, Lingu\xC3\xA8re, and Ran\xC3\xA9rou (Senegal). Seven adjacent HFCAs were selected as comparison. Villages within the intervention HFCAs were stratified according to the 2013 incidences of passively detected malaria cases, and those with an incidence\xE2\x80\x89\xE2\x89\xA5\xE2\x80\x8915 cases/1000/year were targeted for a mass test and treat (MTAT) in September 2014. All households were visited, all consenting individuals were tested with a rapid diagnostic test (RDT), and, if positive, treated with dihydroartemisinin-piperaquine. This was followed by weekly screening, testing and treatment of fever cases (PECADOM++) until the end of the transmission season in January 2015. Villages with lower incidence received only PECADOM++ or case investigation. To evaluate the impact of the interventions over that transmission season, the incidence of passively detected, RDT-confirmed malaria cases was compared between the intervention and comparison groups with a difference-in-difference analysis using negative binomial regression with random effects on HFCA." - Label: RESULTS NlmCategory: RESULTS content: "During MTAT, 89% (2225/2503) of households were visited and 86% (18,992/22,170) of individuals were tested, for a combined 77% effective coverage. Among those tested, 291 (1.5%) were RDT positive (range 0-10.8 by village), of whom 82% were\xE2\x80\x89<\xE2\x80\x8920\xC2\xA0years old and 70% were afebrile. During the PECADOM++ 40,002 visits were conducted to find 2784 individuals reporting fever, with an RDT positivity of 6.5% (170/2612). The combination of interventions resulted in an estimated 38% larger decrease in malaria case incidence in the intervention compared to the comparison group (adjusted incidence risk ratio\xE2\x80\x89=\xE2\x80\x890.62, 95% CI 0.45-0.84, p\xE2\x80\x89=\xE2\x80\x890.002). The cost of the MTAT was $14.3 per person." - Label: CONCLUSIONS NlmCategory: CONCLUSIONS content: It was operationally feasible to conduct MTAT and PECADOM++ with high coverage, although PECADOM++ was not an efficient strategy to complement MTAT. The modest impact of the intervention package suggests a need for alternative or complementary strategies