International Journal of Agricultural Research, Innovation and Technology (IJARIT)
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Spodoptera littoralis genome mining brings insights on the dynamic of expansion of gustatory receptors in polyphagous noctuidae
No full textInternational audienceThe bitter taste, triggered via gustatory receptors, serves as an important natural defense against the ingestion of poisonous foods in animals, and the increased host breadth is usually linked to an increase in the number of gustatory receptor genes. This has been especially observed in polyphagous insect species, such as noctuid species from the Spodoptera genus. However, the dynamic and physical mechanisms leading to these gene expansions and the evolutionary pressures behind them remain elusive. Among major drivers of genome dynamics are the transposable elements but, surprisingly, their potential role in insect gustatory receptor expansion has not been considered yet. In this work, we hypothesized that transposable elements and possibly positive selection would be involved in the highly dynamic evolution of gustatory receptor in Spodoptera spp. We first sequenced de novo the full 465 Mb genome of S. littoralis, and manually annotated the main chemosensory genes, including a large repertoire of 373 gustatory receptor genes (including 19 pseudogenes). We also improved the completeness of S. frugiperda and S. litura gustatory receptor gene repertoires. Then, we annotated transposable elements and revealed that a particular category of class I retrotransposons, the SINE transposons, was significantly enriched in the vicinity of gustatory receptor gene clusters, suggesting a transposon-mediated mechanism for the formation of these clusters. Selection pressure analyses indicated that positive selection within the gustatory receptor gene family is cryptic, only 7 receptors being identified as positively selected. Altogether, our data provide a new good quality Spodoptera genome, pinpoint interesting gustatory receptor candidates for further functional studies and bring valuable genomic information on the mechanisms of gustatory receptor expansions in polyphagous insect species
Effect of Rhizobium Inoculation on Growth of Common Bean in Low-Fertility Tropical Soil Amended with Phosphorus and Lime
No full textInternational audienceThe cultivation of grain legumes (e.g., common bean) in sub-Saharan Africa contributes to the provision of food for a growing population and delivers environmental benefits such as inputs of nitrogen (N) to crops and soil via symbiotic nitrogen fixation (SNF). However, the success of SNF is constrained by several factors such as the poor efficiency of native rhizobial strains to fix N, the low availability of phosphorus (P) and the acidity of soils. Two trials have been conducted in low-fertility tropical soils at the smallholder farm scale in Madagascar to assess the effects of Rhizobium inoculation together with inputs of P and lime on the growth of the common bean. We showed that inoculation with native strains of Rhizobium had significant effects on bean root nodulation, which was increased by up to 15-fold on plant growth, which increased by 78% and on bean yield, which increased by 126%. Moreover, we observed positive and significant relationships between inoculation with Rhizobium and P fertilization on nodulation, plant growth and yield. However, the addition of dolomite lime did not show any effect in our study. The addition of P decreased the mycorrhization rate of roots. Additional research is still needed to improve our understanding of soil fertility conditions (mainly on nutrient availability, including micronutrients) allowing better efficiency of legume symbionts (rhizobium and mycorrhiza) in such low-fertility soils
CHEOPS geometric albedo of the hot Jupiter HD 209458 b
No full textInternational audienceWe report the detection of the secondary eclipse of the hot Jupiter HD 209458 b in optical/visible light using the CHEOPS space telescope. Our measurement of 20.4−3.3+3.2 parts per million translates into a geometric albedo of Ag = 0.096 ± 0.016. The previously estimated dayside temperature of about 1500 K implies that our geometric albedo measurement consists predominantly of reflected starlight and is largely uncontaminated by thermal emission. This makes the present result one of the most robust measurements of Ag for any exoplanet. Our calculations of the bandpass-integrated geometric albedo demonstrate that the measured value of Ag is consistent with a cloud-free atmosphere, where starlight is reflected via Rayleigh scattering by hydrogen molecules, and the water and sodium abundances are consistent with stellar metallicity. We predict that the bandpass-integrated TESS geometric albedo is too faint to detect and that a phase curve of HD 209458 b observed by CHEOPS would have a distinct shape associated with Rayleigh scattering if the atmosphere is indeed cloud free. The raw and detrended photometric time-series data are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/659/L4</A
Macrotermes termite mounds influence the spatial pattern of tree species in two African rainforest sites, in northern Congo. But were they really forests in the past?
No full textInternational audienceTermite mounds have been poorly studied in tropical rainforest in contrast to those of savannahs where they create fertility hotspots and influence the spatial pattern of vegetation. An inventory of termite mounds and of 15 tree species with a diameter at breast height ≥ 10 cm was carried out in two 800-ha blocks, in two rainforest sites located in northern Congo. We used inhomogeneous and intertype K functions to study the spatial pattern of termite mounds and of tree species around mounds, respectively. We found that mounds in Loundoungou were over-dispersed within a radius of less than 70 m, while those in Mokabi were randomly spaced. Tree species within a 20-m radius around a mound were aggregated towards the mound, e.g. Entandrophragma cylindricum , randomly distributed, or even repulsed by the mound. The specific responses also differed in the two sites. These results suggest that (i) the mounds in Loundoungou were created by savannah termite species 3,000-2,000 years BP during the Late Holocene Rainforest Crisis and (ii) the mounds in Mokabi are characteristic of forest mounds. The impact of termite mounds on the spatial pattern of tree species is thus site-dependent, and these differences might be due to species seed dispersal strategies and to soil calcium concentrations
Reconnaissance Faciale Dans des Bases de Données d'Images à l'Aide des Modèles de Markov Cachés
No full textsoumission à EpisciencesIn this paper, we present a new approach to Facial Recognition (FR) that uses Hidden Markov Models. The method we propose enhances the HMM by integrating a clustering step for the partitioning of each face image before building the associated model. We then propose an algorithm for converting the HMM model into a vector in order to apply the usual metrics such as the Euclidean distance and the Manhattan distance in the faces model comparison phase. We apply this algorithm to a publicly available image databases FERET, which allowed us to obtain 100.00% True Positive Rates (TPR) and 99.98% True Negative Rates (TNR) for our enhanced HMMs method, compared to 100.00% of TPR and 99.95% of TNR with Grid+HMMs, then 77.14% of TPR and 79.05% of TNR with Discrete Markov Models. These performances are obtained on the basis of their confusion matrix, then the sensitivity, specificity, the accuracy, th precision and the F1-Score of each of these methods.Dans cet article, nous présentons une nouvelle approche de la reconnaissance faciale (RF) qui utilise des modèles de Markov cachés. La méthode que nous proposons améliore le HMM en intégrant une étape de clustering pour le partitionnement de chaque image de visage avant de construire le modèle associé. Nous proposons ensuite un algorithme de conversion du modèle HMM en vecteur afin d'appliquer les métriques usuelles telles que la distance euclidienne et la distance de Manhattan dans la phase de comparaison des modèles de visages. Nous appliquons cet algorithme à une base de données d'images accessible au public FERET, ce qui nous a permis d'obtenir 100,00 % de taux de vrais positifs (TPR) et 99,98 % de taux de vrais négatifs (TNR) pour notre méthode HMM améliorée, contre 100,00 % de TPR et 99,95 % de TNR avec Grid+HMMs, puis 77,14 % de TPR et 79,05 % de TNR avec des modèles de Markov discrets. Ces performances sont obtenues sur la base de leur matrice de confusion, puis de la sensibilité, de la spécificité, de l'exactitude, de la précision et du F1-Score de chacune de ces méthodes
Inclusion financière via le mobile money, exposition aux chocs et processus d'adoption de stratégies de résilience financière par les ménages : cas du Cameroun
No full textRelying on the 2017 Cameroon Finscope Consumer survey dataset, the goal of this working paper is to conceptualize households’ adoption of financial resilience strategies to adverse shocks as a multi-step process and investigate the key factors that influence the transition from one step to another as well as the role of mobile money in each of these transitionsEn s'appuyant sur les données de l'enquête Finscope 2017 auprès des consommateurs camerounais, l'objectif de ce document de travail est de conceptualiser l'adoption par les ménages de stratégies de résilience financière face à des chocs défavorables comme un processus à plusieurs étapes et d'étudier les facteurs clés qui influencent la transition d'une étape à l'autre ainsi que le rôle du mobile money dans chacune de ces transitions
Control points deployment in an Intelligent Transportation System for monitoring inter-urban network roadway
No full textInternational audienceAbstractThe constant evolution of transportation systems and traffic in developing countries is nowadays confronted with a problem of road safety and therefore of a high accident rate, especially in the context of inter-urban road transport. In this work, we propose a communication architecture for an Intelligent Transport System (ITS) to provide surveillance in an inter-urban transport network in the context of developing countries. We introduce two types of control points: Relay Control Points (RCP) and Treatment Control Points (TrCP). We also designed two multi-objective models for the deployment of these points. In order to ensure good coverage, to minimize the cost of installation and to put more emphasis in the areas having a high number of accidents. To ensure optimal deployment of these points, we have used the Non-Dominated Sorted Genetic Algorithm II (NSGA-II) that will allow to realize the Pareto front of non-dominated solutions. The results of the simulations show the effectiveness of our proposal
La problématique de la constitution d'épargne par les enseignants mécanisés du SECOPE Antenne Kpandroma
No full textInternational audienceDans l’histoire économique de la RDC, après le Gouvernement de la 2e République jusqu’à nos jours, l’aperçue générale sur la gestion de ressources humaines œuvrant dans certains principaux facteurs tel que l’éducation, facteur clé pour le développement d’un pays, semble diminuée progressivement sa valeur.En période de Zaïre Monnaie, un ancien enseignant recevait 5 Z équivalant à 5000FB, localement convertis à 5 vaches et un nouveau enseignant gagnait 3,7 Z soit 3700FB(Francs Belge) ou l’équivalant de 3,7 vaches, alors qu’à la période de Nouveau Zaïre, un chef de Direction gagnait 340 NZ avec la parité monétaire de 1 NZ à 2 et l’enseignant exécutant gagnait 120 NZ soit 240 ou 95.12$ payable dans un délai aussi très irrégulier. Force est donc de constater, que les enseignants sont promptement et assurément accompagnés vers un régime de non épargne et de non investissement, et nullement leur condition de vie ne peut être améliorée moins encore ils ne peuvent contribuer à l’émergence de l'économie locale si rien n'est fait aussitôt pour leurs causes par le pouvoir central.Toutefois, certains conservent quand même une petite partie de leur revenu sous forme d'épargne pour payer les frais de scolarisation des enfants, frais de soins médicaux, imprévus…, et d’autre partie sert pour des petits investissements dans l'agriculture et élevage et aux petits projets selon le principe Keynésien. Sinon, faute de la présence des agences bancaires dans la région, 42,8% de ces enseignants préfèrent conserver leurs épargnes dans l'opération de ristourne (tontine), 38,7% en constituent la thésaurisation et 6,1% préfèrent les placées dans les mutuelles de solidarité (AVEC), 4% les gardent en monnaie électronique (M-PESA) puis 8,1% préfère quand même la coopérative d'épargne et de crédit nouvellement implantée dans la région (CEMADEF)
Dynamic Optimal Hedge Ratio Design when Price and Production are stochastic with Jump
No full textInternational audienceIn this paper, we focus on the farmer's risk income, by using commodity futures, when price and output processes are correlated random represented by jump-diffusion models. We evaluate the expected utility of the farmer's wealth and we determine, at each instant of time, the optimal consumption rate and hedge position at given the time to harvest and state variables. We find a closed form optimal position of consumption and position rate in case of CARA utility investor. This result (see table 1.5) is a generalization of Ho (1984) result who consider the particular case where price and output are diffusion models
GESTION DES FINANCES PUBLIQUES LOCALES POUR LE DÉVELOPPEMENT DES ETD : " CAS DU SECTEUR DES WALENDU PITSI "
No full textInternational audienceThis article, written under the theme: Managing local public finances for the development of ETDs with experience in the Walendu Pitsi sector," is rare in proposing to explain the purpose for which ETDs are developing a budget and understand how this local financial law is enforced. Following the results obtained and analyzed after the operation of the documents of the Budgets of this entity, which enjoys financial autonomy over the space of three years (2013-2015), revenue forecasts and expenditure execution reveal that expected revenues were weakly mobilized: in the order of 20.02% in 2013, 5.00% in 2014 and 34.84% in 2015 and executed similarly according to the proportion of 19.93% in 2013, 7.13% in 2014 and 32.92% in 2015. This modest revenue and expenditure performance has a direct negative impact on governance and peacekeeping (strengthening institutions), macroeconomic stability and growth and improvement access to social services, reducing vulnerability and supporting community dynamics in the Walendu-Pitsi sector.The public authority in high court must therefore go beyond believing strictly in the financial autonomy of the ETDs otherwise it must be relative, and must be appreciated in terms of the desire to control the decentralizing process in a certain way, because ETD are seen more as conveyor belts of its own policies than as centres of autonomous decisions.Le présent article rédigé sous le thème : Gestion des finances publiques locales pour le développement des ETD (Entité Territoriale Décentralisée) avec l’expérience dans le secteur des Walendu Pitsi " est rare qui se propose d'expliquer la finalité pour laquelle les ETD s'élaborent un budget et de comprendre le mode d'exécution de cette loi financière locale. Au terme des résultats obtenus et analysés après l’exploitation des documents des Budgets de cette entité jouissant de l’autonomie financière sur l’espace de trois années (2013 – 2015), des prévisions en recettes et l’exécution des dépenses nous révèlent que les recettes prévues ont été faiblement mobilisées soit de l’ordre de 20,02% en 2013, 5,00% en 2014 et 34,84% en 2015 et exécutées de même suivant la proportion de 19,93% en 2013, 7,13% en 2014 et 32,92% en 2015.Cette modicité de la réalisation des recettes et d’exécution des dépenses a des répercussions négatives directes sur la gouvernance et le maintien de la paix (renforcement des institutions), la stabilité macroéconomique et la croissance et l'amélioration d'accès aux services sociaux, la réduction de la vulnérabilité, appui à la dynamique communautaire en secteur des Walendu – Pitsi.Le pouvoir public en haute instance doit donc se dépasser de croire strictement à l'autonomie financière des ETD sinon, celle-ci doit être relative, et doit s'apprécier au regard de la volonté de contrôler le processus décentralisateur d'une certaine façon, car les ETD sont plus considérés comme des courroies de transmission de ses propres politiques que comme des centres des décisions autonomes