915 research outputs found

    Institutional histories, seasonal floodplains (mares), and livelihood impacts of fish stocking in the Inner Niger River Delta of Mali

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    The Community-based Fish Culture in Seasonal Floodplains and Irrigation Systems (CBFC) project is a five year research project supported by the Challenge Program on Water and Food (CPWF), with the aim of increasing productivity of seasonally occurring water bodies through aquaculture. The project has been implemented in Bangladesh, Cambodia, China, Mali and Vietnam, where technical and institutional options for community based aquaculture have been tested. The project began in 2005 and was completed in March 2010. The seasonally flooded depressions in the Inner Niger Delta (known as mares) represent a critical fishery resource for the inhabitants of the village of Komio, and at present, access is open to all residents. A proposal to build stocked fish enclosures in the main village mare presents potential benefits and risks. On one hand, overall productivity in the mare could be significantly increased, providing important sources of protein and cash during the annual drought period, when few livelihood activities can be performed and when village livelihoods are at their most vulnerable. Enhanced productivity in mares may also decrease local household pressures for seasonal labor migration. On the other hand, a resulting increase in the value of these mares may encourage elite capture of project benefits or rentseeking by certain village leaders of the landowning Marka ethnic group. Using qualitative interviews and focus group discussions, the study provides evidence of how local institutional and leadership capacity for equitable common property resource management have evolved since the introduction of irrigated farming systems (known as PΘrimΦtres IrriguΘs Villageois or PIVs) in the 1990s.Fishing rights, River fisheries, Livelihoods

    Efficacité d’une prise unique de Praziquantel pour le traitement de la bilharziose urinaire en zones endémiques chez les enfants d'âge scolaire au Mali

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    Au Mali, la schistosomiase est un problème de santĂ© publique comme dans tous les 42 paysafricains sur 76 concernĂ©s dans le monde, avec 230 millions de personnes infectĂ©es sur 800 millions de personnes exposĂ©es et plus de 800 000 dĂ©cès annuels. L’objectif de cette Ă©tude Ă©tait de tester l’efficacitĂ© d’une dose unique de Plaziquantel pour traiter les enfants d’âge scolaire de 11 villages maliens situĂ©s en zones endĂ©miques de la schistosomiase urinaire. Après assentiment ou consentement, l’enregistrement des volontaires âgĂ©s de cinq ans ou plus a Ă©tĂ© fait. Après dĂ©pistage systĂ©matique de l’ensemble des volontaires pour savoir la prĂ©valence de l’infection avant traitement, une dose unique de Praziquantel a Ă©tĂ© donnĂ©e aux sujets infectĂ©s. Un mois après la prise du mĂ©dicament, un second dĂ©pistage a Ă©tĂ© fait chez les mĂŞmes volontaires afin de mesurer l’effet du traitement. La technique de filtration de l'urine pour la dĂ©tection de l'excrĂ©tion des Ĺ“ufs de schistosomiase a Ă©tĂ© utilisĂ©e comme mĂ©thode de diagnostic. Sur 549 volontaires testĂ©s Ă  l’enregistrement (397 fĂ©minins et 152 masculins), 9,1% (51/549) Ă©taient infectĂ©s par S. haematobium. Un mois après le traitement Ă  la dose unique de Praziquantel, un taux de rĂ©duction significatif de 3,5% (P= 0,03) a Ă©tĂ© constatĂ©. Cette Ă©tude a montrĂ© que le Praziquantel reste toujours efficace pour le traitement de la schistosomiase urinaire. Le maintien de ce produit comme molĂ©cule distribuĂ©e pour le traitement de masse du programme national de lutte contre la schistosomiase est justifiĂ©.   In Mali, schistosomiasis is a public health problem as in all 42 African countries out of 76 affected worldwide, with 230 million people infected in 800 million people exposed and more than 800 000 annual deaths. The objective of this study was to test the efficiency of a single dose of Plaziquantel to treat school-age children in 11 Malian villages located in endemic areas of urinary schistosomiasis. After consent, the enrolment of volunteers greater than 5 years old was done. After systematic screening of all volunteers for the prevalence of infection before treatment, a single dose of Praziquantel was given to infected individuals. One month after drug administration, a second screening was done among the same volunteers to measure the treatment effect. The technique of schistosomiasis eggs detection by urine filtration was used as a diagnostic method. From the screening including 549 volunteers (397 females and 152 males), 9.1% (51/549) were positives to S. haematobiuminfection. One month after treatment with a single dose of Praziquantel, a significant rate reduction (3.5%, P= 0.03) was observed. This study showed that Praziquantel is still effective for the treatment of urinary schistosomiasis. The choice of this drug by the national schistosomiasis control program for community mass treatment was justified

    Spatiotemporal chaos induces extreme events in an extended microcavity laser

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    Extreme events such as rogue wave in optics and fluids are often associated with the merging dynamics of coherent structures. We present experimental and numerical results on the physics of extreme events appearance in a spatially extended semiconductor microcavity laser with intracavity saturable absorber. This system can display deterministic irregular dynamics only thanks to spatial coupling through diffraction of light. We have identified parameter regions where extreme events are encountered and established the origin of this dynamics in the emergence of deterministic spatiotemporal chaos, through the correspondence between the proportion of extreme events and the dimension of the strange attractor

    Etude des paramètres sériques biochimiques : le cas des lapins (Néozelandais – cunistar) de Côte d\'ivoire.

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    une insuffisance des bases données. Les valeurs obtenues sur l\'ensemble des sérums des animaux ont permis d\'observer les moyennes au niveau de la glycémie (0,79 ± 0,18 g/l) et des métabolites tels que, l\'urée (0,42 ± 0,10 g/l), la créatinine (6,88 ± 1,66 mg/l), l\'acide urique (5,42 3,75 mg/l), le cholestérol total (0,55 ± 0,13 mg/l), les triglycérides (2,18 ± 1,23 g/l), les protéines totales (26,00 ± 15,16 g/l), les bilirubines totales (7,25 ± 1,07 mg/l) et les bilirubines directes 1,58 ± 0,38 mg/l. Concernant les enzymes, les déterminations des valeurs ont été faites pour la transaminase alanine - aminotransférase (45,52 ± 20,54 UI/l), la transaminase aspartate - aminotransférase (21,24 ± 9,89 UI/l), les phosphatases alcalines (432,66 ± 207,8 UI/l), la ã Glutamyl transférase (24,24 ± 15,21 UI/l), les créatine phosphokinases (954 ± 343,4 UI/l), les lactates déshydrogénases (1135 ± 335,93 UI/l) et enfin les amylases (114,72 ± 27,99 UI/l). Par ailleurs, les moyennes des ions ont été déterminées pour le calcium (94 ± 4,43 mg/l), le magnésium (15,72 ± 2,49 mg/ l), le phosphore (26,70 ± 10,51 mg/l), le fer sérique (1,33 ± 0,74 mg/l), le sodium (141,89 ± 3,96 mg/l), le potassium (3,89 ± 0,38 mg/l) et enfin le chlore (100,85 ± 3,04 mg/l). En conclusion, les valeurs obtenues en zone tropicale nécessitent une évaluation avec un échantillonnage plus grand pour des comparaisons avec des données européennesStudy of biochemical serum constituents among rabbits (Néozélandais-cunistar) in Côte d\'Ivoire is carried out as a result insufficiency of available data. Values acquired from all animals serum allowed to look at glycemia (0.79 ± 0.18 g/l) and metabolites related averages such as, urea (0.42 ± 0.10 g/l), creatinine (6.88 ± 1.66 mg/l), uric acid (5.42 ± 3.75 mg/l), total cholesterol (0.55 ± 0.13 mg/l), triglycol (2.18 ± 1.23 g/l), total proteins (26.00 ± 15.16 g/l), total bilirubins (7.25 ± 1.07 mg/l) and bilirubins direct (1.58 ± 0.38 mg/l). Concerning enzymes, averages were worked out for alanine - aminotransferase (45.52 ± 20.54 UI/l), aspartate - aminotransferase (21.24 ± 9.89 UI/l), phosphatases alkaline (432.66 ± 207.8 UI/l), ã Glutamyl transférase (24.24 ± 15.21 UI/l), créatine kinase (954 ± 343.4 UI/l), lactate deshydrogenase (1135 ± 335.93 UI/l) and the amylases (114.72 ± 27.99 UI/l). Besides as to ions, the averages were determined for calcium (94 ± 4.43 mg/l), magnesium (15.72 ± 2.49 mg/l), phosphor (26.70 ± 10.51 mg/l), iron serum (1.33 ± 0.74 mg/l), sodium (141.89 ± 3.96 mg/l), potassium (3.89 ± 0.38 mg/l) and chlorine (100.85 ± 3.04 mg/l). In short, the values obtained in tropical area require assessment with a larger sampling for comparisons with European data. Keywords: paramètr.es sériques, Néozélandais -Cunistar, lapin./serum parameters, Néozélandais - Cunistar, rabbit.Sciences & Nature Vol. 4 (1) 2007: pp. 37-4

    Localized Faraday patterns under heterogeneous parametric excitation

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    Faraday waves are a classic example of a system in which an extended pattern emerges under spatially uniform forcing. Motivated by systems in which uniform excitation is not plausible, we study both experimentally and theoretically the effect of heterogeneous forcing on Faraday waves. Our experiments show that vibrations restricted to finite regions lead to the formation of localized subharmonic wave patterns and change the onset of the instability. The prototype model used for the theoretical calculations is the parametrically driven and damped nonlinear Schr\"odinger equation, which is known to describe well Faraday-instability regimes. For an energy injection with a Gaussian spatial profile, we show that the evolution of the envelope of the wave pattern can be reduced to a Weber-equation eigenvalue problem. Our theoretical results provide very good predictions of our experimental observations provided that the decay length scale of the Gaussian profile is much larger than the pattern wavelength.Comment: 10 pages, 9 figures, Accepte

    Landscape analysis – Assessing countries' readiness to scale up nutrition actions in the WHO African region

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    The purpose of this paper is to describe the use of the Landscape Analysis to assess strengths and weaknesses in combating malnutrition in Sub-Saharan Africa. The Landscape Analysis is an inter-agency initiative to assess gaps and constraints and to identify opportunities for effective nutrition actions in order to accelerate intersectoral action for improving nutrition. In-depth Country Assessments to evaluate countries' "readiness" to scale up nutrition action have been conducted since 2008 in Sub-Saharan Africa. "Readiness" was assessed in terms of the  commitment and capacity of each country and the focus was high stunting burden countries. The main focus was countries with heavy burden of undernutrition. From 2008 to September 2011, a total of 14 countries had undertaken the Landscape Analysis Country Assessment. Nine of them were in Africa: Burkina Faso, Comoros, Cote d’Ivoire, Ethiopia, Ghana, Madagascar, Mali, Mozambique, and South Africa. Three additionalcountries (Guinea, Namibia and Tanzania) were also planning to complete the Landscape Analysis Country Assessment in early 2012.From the findings in the nine countries, the following recommendations have beenmade:• Existing nutrition architectures and coordination mechanisms should bestrengthened and better utilized;• Nutrition needs to be mainstreamed and integrated in relevant sector policies;• Advocacy at high levels is needed to highlight the importance of the lifecourseperspective, focusing particularly on nutrition interventions frompreconception until the first two years of life;• National nutrition policies need to be translated into programmatic actions;• Human resource capacity for public health nutrition needs to be built with highquality in-service trainings in the short-term and long-term strategies toprovide pre-service trainings;• Community-based outreach should be strengthened by using existingchannels;• National nutrition surveillance systems need to be strengthened to ensure adequate use of data for monitoring, evaluation, and planning purposes.As part of the implementation of the 2010 World Health Assembly resolution on Infant and Young Child Nutrition (WHA 63.23) WHO has proposed a process to help countries in developing scale-up plans, which incorporates the Landscape Analysis Country Assessment as a tool to help countries in undertaking the initial context mapping. The countries that have already undertaken an in-depth Country Assessment, such as the Landscape Analysis Country Assessment, are ready to move forward in implementing the next steps in developing scaling-up plans to accelerateaction in nutrition. At the same time, WHO will support additional countries that have expressed interest in conducting the Country Assessment

    Evaluation de l’efficacite de quatre formulations de chlorpyriphos ethyl contre la cochenille Farineuse du manguier Rastrococcus invadens Williams (Homoptera : Pseudococcidae) : bilan de dix annees d’experimentation en Côte D’Ivoire

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    La cochenille farineuse du manguier, Rastrococcus invadens (Homoptera : Pseudococcidae) est l’un des principaux ravageurs du manguier en Côte d’Ivoire, particulièrement dans la région nord qui fournit les mangues exportées. En attendant la mise en place de la lutte biologique envisagée, et devant l’ampleur des dégâts pouvant favoriser des traitements abusifs de la part des producteurs, des expérimentations ont été initiées pour sélectionner des insecticides efficaces en vue de leur homologation. Sur station de recherche, le premier screening a concerné 8 formulations d’insecticides appliquées à doses fortes (2 litres / ha) sur 100 m² de parcelle élémentaire de manguiers. Ensuite, pour chaque formulation retenue, trois doses ont été testées (2 litres / ha, 1 litre / ha et 0,5 litre / ha) sur 200 m². En milieu paysan, la dose optimale a été confirmée sur au moins 20 ha dans des essais couples. Le screening préliminaire a mis en évidence l’efficacité des formulations à base de chlorpyrifos éthyl avec une rémanence de 4 semaines. L’évaluation de 3 doses de ces formulations en station a permis de retenir la dose efficace de 1 litre / ha soit 480 g dechlorpyrifos-éthyl / ha. Les tests réalisés en milieu paysan ont confirmé l’efficacité des 4 formulations de chlorpyrifos-éthyl contre le ravageur : Dursban 4 E, Cyren 480 EC, Pyriforce 480 EC et Pyrical 480 EC. L’exécution raisonnée des traitements permet à la lutte chimique de s’intégrer harmonieusement dans un programme de gestion intégrée de la cochenille farineuse.Mots clés : Rastrococcus invadens, cochenille farineuse du manguier, lutte chimique, chlorpyrifos-éthyl.EVALUATION OF FOUR FORMULATIONS OF CHLORPYRIPHOS ETHYL AGAINST THE MANGO MEALY BUG Rastrococcus invadensWILLIAMS  (HOMOPTERA : PSEUDOCOCCIDAE) : ASSESSMENTOF TEN YEARS  EXPERIMENTATION IN CÔTE D’IVOIREThe mango mealy bug, Rastrococcus invadens (Homoptera,  Pseudococcidae) is one of the main pests of mango in Côte d’Ivoire,  particularly in the northern region that provides the exported mangoes. Before the using of biological control considered, and faced with the extent of damages that may promote abusive treatment by the producers,  experiments were initiated to select effective insecticides for their approval. On research station, the first screening has involved eight formulations of insecticides applied at high doses (2 L / ha) of 100 m² plot of mango trees. Then, for each formulation selected, three doses were tested (2 liters / ha, 1 liter / ha and 0.5 l / ha) on 200 m². On-farm, the optimal dose was confirmed at least 20 ha in trials couples. The preliminary  screening has shown the effectiveness of formulations containing  chlorpyrifos ethyl with a remanence of 4 weeks. The evaluation of three  doses of these formulations on station allowed to retain the effective dose of 1 l / ha or 480 g of chlorpyrifos-ethyl / ha. The on-farm tests have  confirmed the effectiveness of four formulations of chlorpyrifos-ethyl against the pest: Dursban 4 E, Cyren 480 EC, Pyriforce 480 EC and Pyrical 480 EC. The rational treatment allows to chemical control to integrate  seamlessly into an integrated management program against the mealy  bug.Key words : Rastrococcus invadens, mango mealy bug, chemical control, chlorpyrifos ethyl

    Developpement des systemes de production innovants d’association mais/legumineuses dans la zone subhumide du Mali

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    Parmi les 3 piliers de l’intégration agriculture-élevage (traction animale, fumure organique, cultures fourragères) diffusés en Afrique de l’Ouest, seules les cultures fourragères ont été peu adoptées. Pourtant, les associations maïs/légumineuses ont l’avantage d’améliorer la production et l’alimentation animale. Elles représentent une alternative dans la gestion des risques et des incertitudes pour les agro-éleveurs, confrontés aux changements globaux (climatiques, pression foncière, dégradation des ressources naturelles). L’objectif de cette étude est de déterminer la contribution des associations maïs/légumineuses dans l’amélioration de la production de maïs grain et le bilan fourrager des exploitations agricoles. Le dispositif en blocs dispersés chez 10 producteurs, a consisté en 3 traitements, T1 (maïs seul), T2 (maïs/ niébé) et T3 (maïs/mucuna) durant 2 campagnes agricoles. En 2013 - 2014, les rendements de maïs grain ont été de 2433 kg/ha et en biomasse 2597 kgMS/ha. Par contre, en 2014 - 2015 les rendements ont été de 1932 kg/ha de maïs grain et de 5134 kgMS/ha de biomasse. Les besoins en matière sèche pour 90 jours de supplémentation ont été de 4,62 UBT en 2013 - 2014 et de 9,13 UBT en 2014 - 2015. Ces résultats montrent la contribution des associations maïs/légumineuses dans l’amélioration du rendement de maïs grain et de fourrages dans la zone subhumide au Mali.Mots clés : légumineuses, maïs, fourrage, Mal

    Heterosis Increases Fertility, Fecundity and Survival of Laboratory-Produced F1 Hybrid Males of the Malaria Mosquito Anopheles coluzzii

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    The success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically-modified male mosquitoes critically depends on mating between laboratory-reared males and wild females. Unfortunately, mosquito colonization, laboratory rearing, and genetic manipulations can all negatively affect male competitiveness. Heterosis is commonly used to produce domestic animals with enhanced vigor and homogenous genetic background and could therefore potentially improve the mating performance of mass-reared male mosquitoes. Here, we produced enhanced hybrid males of the malaria mosquito Anopheles coluzzii by crossing two strains colonized 35+ and 8 years ago. We compared the amount of sperm and mating plug proteins they transferred to females, as well as their insemination rate, reproductive success and longevity under various experimental conditions. Across experiments widespread adaptations to laboratory mating were detected in the older strain. In large-group mating experiments, no overall hybrid advantage in insemination rates and the amount of sperm and accessory gland proteins transferred to females was detected. Despite higher sperm activity, hybrid males did not appear more fecund. However, individual-male mating and laboratory-swarm experiments revealed that hybrid males, while inseminating fewer females than older inbred males, were significantly more fertile, producing larger mating plugs and drastically increasing female fecundity. Heterotic males also showed increased longevity. These results validate the use of heterosis for creating hybrid males with improved fitness from long-established inbred laboratory strains. Therefore, this simple approach could facilitate disease control strategies based on male mosquito releases with important ultimate benefits to human health
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