Analyse diagnostique des systemes de culture en riziculture de bas-fonds a Gagnoa, au centre ouest de la Cote d’Ivoire

L’analyse diagnostique des systèmes de culture en riziculture de bas-fond vise une meilleure compréhension des pratiques culturales, l’estimation des résultats techniques et économiques, et l’identification des contraintes de production du riz en écologie de bas-fonds en Côte d’Ivoire. L’étude a été réalisée dans le pôle de développement rizicole de Gagnoa au Centre Ouest de la Côte d’Ivoire. La méthode de collecte des données était l’enquête de groupe au niveau village et l’enquête individuelle au niveau ménage basées sur une approche d’automatisation de collecte des données à l’aide des tablettes et Smartphones. La méthodologie d’échantillonnage stratifié et aléatoire a été utilisée. L’enquête a concerné 32 villages et 384 producteurs, à raison de 12 riziculteurs par village. Les résultats ont montré que 80% des riziculteurs chefs de ménage étaient de sexe masculin contre 20 % de riziculteurs chefs de ménage de sexe féminin. La superficie moyenne emblavée pour le riz était de 1 ha. Les rendements, encore faibles, variaient entre 1,53 et 1,70 t/ha, respectivement, en riziculture de bas-fond non aménagé (sans irrigation) et en riziculture de basfond aménagé (avec irrigation). Concernant les performances économiques, le revenu net d’exploitation en riziculture de bas-fond sans irrigation (33.903fcfa/ha) était inférieur à celui de bas-fond avec irrigation (78.083 fcfa/ha). Les riziculteurs à Gagnoa sont confrontés à plusieurs contraintes dont les plus citées sont les mauvaises herbes (29,2 %), les ravageurs, notamment les oiseaux, les mammifères rongeurs et les insectes (15,4 %) et l’insuffisance des moyens financiers (13,9 %). Ces résultats constituent une base utile pour les interventions futures dans le domaine de la riziculture pour assurer la sécurité alimentaire en Côte d’Ivoire.Mots clés: riz de bas-fonds, rentabilité, contraintes, Côte d’IvoireEnglish Title: Analysis of rice cropping systems in lowland ecology in Gagnoa, in the middle west of  Côte d’IvoireEnglish AbstractAnalysis of rice cropping systems in lowland ecology in Gagnoa, in the Middle West of Côte d’Ivoire aims a better understanding of agricultural practices, estimation of technical and economic performance and identification of constraints of rice production. This study was done in the rice hub of Gagnoa. Focus-group and household level interviews with tablets and Smartphones were used for data collection. Stratified and random sampling methods were adopted to select 32 villages and 384 rice producers (12 rice growers per village).Results showed that 80 % of household heads are male and 20 % are female. Rice area in the region was on average 1 ha per household. Yields, still low, varied from 1.53 to 1.70 tons/ha in rainfed lowland and irrigated lowland, respectively. Regarding the economic performances of cropping systems, net revenue in rainfed lowland (33.903 fcfa/ha) is lower than the one in the irrigated system (78.083 fcfa/ha)...infestation (29.2 %), rice pest such as birds, rodent and insects (15.4 %) and lake of credit (13.9 %). These results are useful for further investigations in the rice production for food security in Côte d’Ivoire.Keywords: lowland rice, profitability, constraints, Côte d’Ivoir

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

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

Cost-effectiveness of community-based screening and treatment of moderate acute malnutrition in Mali.

IntroductionModerate acute malnutrition (MAM) causes substantial child morbidity and mortality, accounting for 4.4% of deaths and 6.0% of disability-adjusted life years (DALY) lost among children under 5 each year. There is growing consensus on the need to provide appropriate treatment of MAM, both to reduce associated morbidity and mortality and to halt its progression to severe acute malnutrition. We estimated health outcomes, costs and cost-effectiveness of four dietary supplements for MAM treatment in children 6-35 months of age in Mali.MethodsWe conducted a cluster-randomised MAM treatment trial to describe nutritional outcomes of four dietary supplements for the management of MAM: ready-to-use supplementary foods (RUSF; PlumpySup); a specially formulated corn-soy blend (CSB) containing dehulled soybean flour, maize flour, dried skimmed milk, soy oil and a micronutrient pre-mix (CSB++; Super Cereal Plus); Misola, a locally produced, micronutrient-fortified, cereal-legume blend (MI); and locally milled flour (LMF), a mixture of millet, beans, oil and sugar, with a separate micronutrient powder. We used a decision tree model to estimate long-term outcomes and calculated incremental cost-effectiveness ratios (ICERs) comparing the health and economic outcomes of each strategy.ResultsCompared to no MAM treatment, MAM treatment with RUSF, CSB++, MI and LMF reduced the risk of death by 15.4%, 12.7%, 11.9% and 10.3%, respectively. The ICER was US$9821 per death averted (2015 USD) and US$347 per DALY averted for RUSF compared with no MAM treatment.ConclusionMAM treatment with RUSF is cost-effective across a wide range of willingness-to-pay thresholds.Trial registrationNCT01015950

Signal propagation in transmission lines with losses using fibonacci wave functions

In this paper, the general model for an infinite LC ladder network using Fibonacci wave functions that were applied to lossless transmission lines will be extended to transmission lines including losses. The general model that was derived from a first order system transfer function representing a simple RC or RL circuit will be used to model and analyze transmission lines presenting losses. The LC ladder network model can be applied to any order for each inductor current with its parasitic rc resistor and for each capacitor voltage with its parasitic rL  resistor. The extension of the proposed general model to transmission lines with losses is subject to Heaviside condition for both resistors rc  and r

Key traveller groups of relevance to spatial malaria transmission: a survey of movement patterns in four sub-Saharan African countries

Background: As malaria prevalence declines in many parts of the world due to widescale control efforts and as drug-resistant parasites begin to emerge, a quantitative understanding of human movement is becoming increasingly relevant to malaria control. However, despite its importance, significant knowledge gaps remain regarding human movement, particularly in sub-Saharan Africa. Methods: A quantitative survey of human movement patterns was conducted in four countries in sub-Saharan Africa: Mali, Burkina Faso, Zambia, and Tanzania, with three to five survey locations chosen in each country. Questions were included on demographic and trip details, malaria risk behaviour, children accompanying travellers, and mobile phone usage to enable phone signal data to be better correlated with movement. A total of 4352 individuals were interviewed and 6411 trips recorded. Results: A cluster analysis of trips highlighted two distinct traveller groups of relevance to malaria transmission: women travelling with children (in all four countries) and youth workers (in Mali). Women travelling with children were more likely to travel to areas of relatively high malaria prevalence in Mali (OR = 4.46, 95 % CI = 3.42–5.83), Burkina Faso (OR = 1.58, 95 % CI = 1.23–1.58), Zambia (OR = 1.50, 95 % CI = 1.20–1.89), and Tanzania (OR = 2.28, 95 % CI = 1.71–3.05) compared to other travellers. They were also more likely to own bed nets in Burkina Faso (OR = 1.77, 95 % CI = 1.25–2.53) and Zambia (OR = 1.74, 95 % CI = 1.34 2.27), and less likely to own a mobile phone in Mali (OR = 0.50, 95 % CI = 0.39–0.65), Burkina Faso (OR = 0.39, 95 % CI = 0.30–0.52), and Zambia (OR = 0.60, 95 % CI = 0.47–0.76). Malian youth workers were more likely to travel to areas of relatively high malaria prevalence (OR = 23, 95 % CI = 17–31) and for longer durations (mean of 70 days cf 21 days, p < 0.001) compared to other travellers. Conclusions: Women travelling with children were a remarkably consistent traveller group across all four countries surveyed. They are expected to contribute greatly towards spatial malaria transmission because the children they travel with tend to have high parasite prevalence. Youth workers were a significant traveller group in Mali and are expected to contribute greatly to spatial malaria transmission because their movements correlate with seasonal rains and hence peak mosquito densities. Interventions aimed at interrupting spatial transmission of parasites should consider these traveller groups

Evaluation de l’effet repulsif d’extraits de neem (Azadirachta indica A. Juss., 1830) sur le charançon de la patate douce (Cylas puncticollis Boheman, 1833) en condition de laboratoire a Korhogo, nord de la Cote d’Ivoire

Une stratégie de gestion intégrée des insectes nuisibles à la culture de la patate douce a été élaborée pour réduire les pertes dues à ceux-ci. Ainsi, les propriétés répulsives des extraits de feuilles et d’amandes de neem ont été évaluées sur Cylas puncticollis, un charançon de la patate douce. Pour ce faire, quatre concentrations d’extraits ont été préparées à raison de quatre répétitions par concentration. Le test a consisté à la détermination du pourcentage de charançons présents dans la zone traitée. Chacune des concentrations d’extraits a été appliquée sur la moitié d’un papier buvard placé dans une boite de Pétri de 9 cm de diamètre et sur lequel 10 charançons ont été posés. Les effets répulsifs des extraits ont été comparés à ceux d’un insecticide chimique et l’eau distillée. Le test avec 20 cL/L d’extraits de feuilles a causé 85 % de répulsion contre 45 % pour les amandes à 25 g/L. Les extraits ont significativement causé plus de répulsion que l’eau distillée et l’insecticide chimique. Les tests ont révélé un potentiel plus répulsif des extraits de feuilles comparé à celui des amandes. Les extraits de neem pourraient constituer une alternative crédible à la lutte chimique pour la protection de la patate douce contre ce charançon. English title: Evaluation of the repellent effect of neem extracts (Azadirachta indica A. Juss., 1830) on the sweet potato weevil (Cylas puncticollis Boheman, 1833) under laboratory conditions in Korhogo, northern Côte d’Ivoire Abstract An integrated pest management strategy for sweet potatoes has been developed to reduce pest losses. Thus, the repellent properties of neem leaf and kernel extracts were evaluated on Cylas puncticollis, a sweet potato weevil. For this purpose, four concentrations of extracts were prepared with four replicates per concentration. The test consisted of determining the percentage of weevils in the treated area. Each of the extract concentrations was applied to half of a blotting paper placed in 9 cm diameter Petri dishes on which 10 weevils were placed. The repellent effects of the extracts were compared to those of a chemical insecticide and distilled water. Test with 20 cL/L leaf extract caused 85% repellence compared to 45% for almonds at 25 g/L. Compared to the chemical insecticide and distilled water, the extracts caused significantly more repellence. The tests revealed a higher repellent potential of the leaf extracts compared to those of almonds. Neem extracts could be a credible alternative to chemical control for the protection of sweet potato against this weevil. Keywords: Neem extracts, Repellent effect, Sweet potato, Cylas puncticolli

Introduction

The shipping industry transported a total volume of 10.3 billion tons of cargo in 2017 (UNCTAD 2017) and is estimated to employ 1.5 million workers (http://www.ilo.org/global/standards/subjects-covered-by-international-labour-standards/seafarers/lang--en/index.htm accessed 1/2/18) who are classed as seafarers. Such workers are employed on different vessel types in the cruise and cargo sectors. Sailors working for the military are not classed as seafarers. However, seafarers may be employed on board in a variety of roles which are not directly associated with marine navigation (as croupiers or entertainers on a cruise ship for example) but their ship should be engaged in a voyage which would differentiate them from taking a ‘fishing trip’ for example. Doumbia-Henry describes some of the provisions of ILO Convention No. 185 stating that

Review on the cost optimization of microgrids via particle swarm optimization

Economic analysis is an important tool in evaluating the performances of microgrid (MG) operations and sizing. Optimization techniques are required for operating and sizing an MG as economically as possible. Various optimization approaches are applied to MGs, which include classic and artificial intelligence techniques. Particle swarm optimization (PSO) is one of the most frequently used methods for cost optimization due to its high performance and flexibility. PSO has various versions and can be combined with other intelligent methods to realize improved performance optimization. This paper reviews the cost minimization performances of various economic models that are based on PSO with regard to MG operations and sizing. First, PSO is described, and its performance is analyzed. Second, various objective functions, constraints and cost functions that are used in MG optimizations are presented. Then, various applications of PSO for MG sizing and operations are reviewed. Additionally, optimal operation costs that are related to the energy management strategy, unit commitment, economic dispatch and optimal power flow are investigated. © 2019, The Author(s)