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Abstract Background Plasmodium-refractory mosquitoes are being rapidly developed for malaria control but will only succeed if they can successfully compete for mates when released into the wild. Pre-copulatory behavioural traits maintain genetic population structure in wild mosquito populations and mating barriers have foiled previous attempts to control malaria vectors through sterile male release. Methods Varying numbers of virgin male and female Anopheles gambiae Giles, from two strains of different innate sizes, were allowed to mate under standardized conditions in laboratory cages, following which, the insemination status, oviposition success and egg batch size of each female was assessed. The influence of male and female numbers, strain combination and female size were determined using logistic regression, correlation analysis and a simple mechanistic model of male competition for females. Results Male An. gambiae select females on the basis of size because of much greater fecundity among large females. Even under conditions where large numbers of males must compete for a smaller number of females, the largest females are more likely to become inseminated, to successfully oviposit and to produce large egg batches. Conclusions Sexual selection, on the basis of size, could either promote or limit the spread of malaria-refractory genes into wild populations and needs to be considered in the continued development and eventual release of transgenic vectors. Fundamental studies of behavioural ecology in malaria vectors such as An. gambiae can have important implications for malaria control and should be prioritised for more extensive investigation in the future.

BackgroundPlasmodium-refractory mosquitoes are being rapidly developed for malaria control but will only succeed if they can successfully compete for mates when released into the wild. Pre-copulatory behavioural traits maintain genetic population structure in wild mosquito populations and mating barriers have foiled previous attempts to control malaria vectors through sterile male release.MethodsVarying numbers of virgin male and female Anopheles gambiae Giles, from two strains of different innate sizes, were allowed to mate under standardized conditions in laboratory cages, following which, the insemination status, oviposition success and egg batch size of each female was assessed. The influence of male and female numbers, strain combination and female size were determined using logistic regression, correlation analysis and a simple mechanistic model of male competition for females.ResultsMale An. gambiae select females on the basis of size because of much greater fecundity among large females. Even under conditions where large numbers of males must compete for a smaller number of females, the largest females are more likely to become inseminated, to successfully oviposit and to produce large egg batches.ConclusionsSexual selection, on the basis of size, could either promote or limit the spread of malaria-refractory genes into wild populations and needs to be considered in the continued development and eventual release of transgenic vectors. Fundamental studies of behavioural ecology in malaria vectors such as An. gambiae can have important implications for malaria control and should be prioritised for more extensive investigation in the future.

Résumé : En Côte d'Ivoire, de 1999 à 2011, l'instabilité politique a provoqué des crises ayant fragilisé le tissu social et modifié les modes de vie des populations. Face à ces perturbations, l'interdit a souvent perdu son sens et les valeurs semblent obsolètes, tandis que l'éducation a perdu de son importance. La montée de la violence chez les élèves, les enseignants et les parents suggère une utilisation fréquente de la violence pour résoudre rapidement les problèmes. Cette étude se demande si ces personnes comprennent réellement les graves conséquences des crises sociopolitiques dans les écoles et comment réduire les effets négatifs de ces bouleversements sociaux pour construire un système éducatif plus performant. L'étude s'appuie sur la théorie des représentations sociales de Moscovici (1961) et l'approche structurale d'Abric (1976) pour analyser les pensées des enseignants et celles des parents concernant l'impact des crises dans les écoles ivoiriennes. Deux cents individus, comprenant 100 enseignants et 100 parents d'élèves d'Abobo à Abidjan, de Boundiali, de Korhogo et de Bouaké en Côte d'Ivoire, ont été soumis à un questionnaire d'évocations hiérarchisées. Les résultats montrent que les représentations sociales se caractérisent principalement par les concepts de violence, de mort, de baisse du niveau et de fermeture des écoles. Une analyse plus approfondie de ces représentations pourrait contribuer à lutter plus efficacement contre les crises dans la société. Mots-clés : Approche psychosociale, évocations hiérarchisées, enseignants, représentations sociales, éléments centraux, éléments périphériques

The objective of this study was to investigate the agro-morphological and phenological characteristics of ten Bambara groundnut landraces that originated in the Ivory Coast. The study was conducted on an experimental plot at the University of Abobo-Adjame. The trial was set up according to a randomized complete block design with five replications. Twenty variables were used to identify the landraces. Landraces Ci1, Ci3, Ci10 and Ci12 exhibited high emergence percentages, early maturity within 90 DAS (days after sowing) and low vegetative/floral development. A high seed yield (388 to 495 kg/ha) was also obtained from these landraces. In contrast, a low seedling emergence rate, high vegetative development and yield (80 kg/ha) could be observed with landrace Ci9. This landrace reached maturity within 180 DAS. Landraces Ci2, Ci4, Ci5, and Ci8, on the other hand, reached maturity between 120-150 DAS. The principal component analysis conducted on the data obtained showed that the landraces with a high seed yield were early in terms of flowering and maturity, but presented low vegetative development, with limited foliage, secondary roots, leaf area and biomass. The physiological and agronomical traits presented by landraces that originated in the Ivory Coast could be exploited in Bambara groundnut varietal improvement programmes. [ABSTRACT FROM AUTHOR]

The research performed on yam processing mainly concerns the production of crisps and flour. However, its transformation into deep-frozen French fries does not necessitate any other equipment than those used for potatoes. The industrial process of production of frozen French fries traditionally includes a pre-frying step. These steps contribute to the development of color and crispness, and the oil partially absorbed inhibits dehydration during the freezing step. The aim of this study was to optimize frying conditions of deep-frozen fried yam (Dioscorea cayenensis var Kponan) slices. The effect of pre-frying time and temperature, final frying time and temperature on the oil uptake, texture, dry matter and colour of the fried yam slices has been studied. Frying conditions optimized with Box-Behnken experimental design were short pre-frying and frying conditions at high temperature characterized by pre-frying temperature at 157-170°C during 5-9s and frying temperature at 181-188°C for 2min 15s-2min 30s; or long pre-frying and frying conditions at low temperature characterized by pre-frying temperature at 150-158°C during 10-15s and frying temperature 170-177°C for 3-3min 15s. An adiabatic system was also developed by means of an insulator in which the core temperature of fried yam slices can be maintained constant at about 55°C after 15min of cooling, facilitating texture measurements at constant temperature. The present results may help in choosing the yam slices frying condition to be applied in order to achieve the desirable fried yam slices quality, required for protection against certain diseases like obesity. These models may also provide guidance as to how to control these quality parameters by altering four key environmental factors, pre-frying temperature and time and, final frying temperature and time. This process can also be commercialized and does not necessitate any other cost for equipment than those used for potatoes French fries and might be an interesting way of added value processing for this highly perishable yam tuber. [ABSTRACT FROM AUTHOR]

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This paper deals with the regulation problem of irrigation channels with a multi-objective control. The control problem is stated as a boundary control of hyperbolic Saint-Venant Partial Differential Equations (pde). Regulation is done around an equilibrium state and spatial dependency of the operator parameters is taken into account in the linearized model. In this paper previous stability results are generalized using perturbation theory in infinite dimensional Hilbert space, including more general hyperbolic systems. The Internal Model Boundary Control (IMBC) used in a direct approach allows to make a control parameters synthesis by semigroup conservation properties, like the exponential stability. Simulation and experimental results from Valence experimental micro-channel show that this approach should be suitable for more realistic situations. [ABSTRACT FROM AUTHOR]

In Mali the Anopheles gambiae complex consists of An. arabiensis and Mopti, Savanna and Bamako chromosomal forms of An. gambiae s.s. Previous chromosomal data suggests a complete reproductive isolation among these forms. Sequence analysis of rDNA regions led to the characterization of two molecular forms of An. gambiae, named M-form and S-form, which in Mali correspond to Mopti and to Savanna/ Bamako, respectively, while it has failed so far to show any molecular difference between Savanna and Bamako. The population structure of An. gambiae s.I. was analysed in three villages in the Bamako and Sikasso areas of Mali and the frequency of pyrethroid resistance of the knock-down resistance (kdr) type was calculated. The results show that the kdr allele is associated only with the Savanna form populations and absent in sympatric and synchronous populations of Bamako, Mopti and An. arabiensis. This is the first molecular indication of barriers to gene flow between the Bamako and Savanna chromosomal forms. Moreover, analyses of specimens collected in the Bamako area in 1987 show that the kdr allele was already present in the Savanna population at that time, and that the frequency of this allele has gradually increased since then. [ABSTRACT FROM AUTHOR]

Abstract Anopheles gambiae populations in west Africa are complex, being composed of multiple, sympatric subpopulations. Recent studies have failed to reveal significant genetic differences among subpopulations, stimulating a debate regarding the levels of gene flow among them. The observed homogeneity may be the consequence of substantial contemporary gene flow or it may be that reproductive isolation is complete, but too recent for the accumulation of significant levels of genic divergence. Here, we report the results of a study estimating contemporary levels of gene flow between An. gambiae subpopulations by analysing females and transferred sperm removed from their reproductive systems. A total of 251 female and associated sperm extracts was analysed from a single site in Mali. Two molecular forms of An. gambiae, the M- and S-forms, occurred in sympatry at this site. Overall, we found very strong positive assortative mating within forms, however, we did observe significant hybridization between forms. In the M subpopulation 2/195 females (1.03%) contained sperm from S-form males and in 55 S-form females we found one female containing M-form sperm (1.82%). We also identified a mated M ×S hybrid adult female. From mating frequencies, we estimate the Nem between the M- and S-form at 16.8, and from the adult hybrid frequency at 5.6. These values are consistent with our earlier estimate, based on FST for 21 microsatellite loci in which Nem = 5.8. We conclude that the general lack of genetic divergence between the M and S subpopulations of An. gambiae can be explained entirely by contemporary gene flow. [ABSTRACT FROM AUTHOR]

This study was focused on the performance of the pile force at the lateral load of an arched bridge. The effect of the compression of arch bridges creates a large horizontal load. Therefore, it is one of the most important factors in the dimensioning of piles. The study aims to make a comparative study between the results obtained in the field, and those obtained by a 3D model defined as a Finite Element (FE) of a drilled pile, subjected to different lateral loads applied at exact time intervals. Moreover, the study was intended to determine the influence of the lateral load applied to a different pile diameter using the FE model. Thus, the unified FEA software Abaqus™ by Dassault systèmes® carried out various processing procedures, namely soil FE modeling, pile FE modeling, soil-pile interface, Mesh, and boundary conditions, to carry out an effective and predictive piles behavior analysis. Based on the Mohr-Coulomb criterion, the soil is considered to be stratified with elastoplastic behavior, whereas the Reinforcement Concrete Pile (RCP) was assumed to be linear isotropic elastic, integrating the concrete damage plasticity. Since the bridge is an arched bridge, the lateral load induced was applied to the head of the piles through a concentrated force to check the pile strength, for which the displacement, stress and strain were taken into account throughout, along the pile depth. The lateral displacement of the pile shows a deformation of the soil as a function of its depth, with different layers crossed with different lateral loads applied. Thus, from the study comparing the results of the FE measurements with the data measured in the field, added to the statistical analyses are as follows: Decrease of the displacement and stress according to the diameter, taking into account the different diameter. The foundations receive loads of the superstructure to be transmitted to the ground. Thus, the piles are generally used as a carrier transmitting loads on the ground. One of the important factors in the durability of the bridge depends more on the strength of these piles. This makes it necessary to study the reinforced concrete foundations because of their ability to resist loads of the structure, and the vertical and lateral loads applied to the structure. This implies an evaluation of the responses of the RCP according to the different lateral loads.