L’effet des droits de propriété sur l’adoption des techniques de conservation des eaux et des sols par les producteurs de céréales au Burkina Faso

This article is an attempt to give an answer to the main research question entitled: what is the effect of property rights on the adoption of water and soil conservation techniques by cereal producers in Burkina Faso. The objective of this article is to evaluate the effect of property rights on the adoption of water and soil conservation techniques by cereal producers in Burkina Faso. A multivariate probit model is used on a sample of 4,813 plots from the survey carried out by the second National Land Management Program (PNGT2) in 2011 on households in Burkina Faso. The results show that formal property rights positively influence the probability of adoption of stone bunds, half-moons and hedgerows. The main conclusion of this research is that formal property rights positively influence the probability of adoption of stone bunds, half-moons and hedgerows. The article therefore recommends the use of water and soil conservation techniques by cereal producers with formal property rights over their plots.Cet article est une tentative de donner une réponse à la question principale de recherche intitulée : quel est l’effet des droits de propriété sur l’adoption des techniques de conservation des eaux et des sols par les producteurs de céréales au Burkina Faso. L’objectif de cet article est d’évaluer l’effet des droits de propriété sur l’adoption des techniques de conservation des eaux et des sols par les producteurs de céréales au Burkina Faso. Un modèle probit multivarié est utilisé sur un échantillon de 4 813 parcelles de l’enquête réalisée par le deuxième Programme National de Gestion des Terroirs (PNGT2) en 2011 sur les ménages au Burkina Faso. Les résultats montrent que les droits de propriété formels influencent positivement la probabilité d’adoption des diguettes en cordons pierreux, des demi-lunes et des haies vives. La principale conclusion de cette recherche est que les droits de propriétés formels influencent positivement la probabilité d’adoption des diguettes en cordons pierreux, des demi-lunes et des haies vives. L’article recommande par conséquent l’utilisation des techniques de conservation des eaux et des sols par les producteurs de céréales disposant de droits de propriété formels sur leurs parcelles

Linear and nonlinear optical absorption characterization of natural laccaic acid dye

We report on the optical performances of laccaic acid dye in solution at different concentrations and dye–poly(methyl methacrylate) composite thin films. The linear spectral characteristics including optical constants, i.e. refractive index (n) and extinction coefficient (k), were carried out in a comprehensive way through absorbance, fluorescence and ellipsometric studies. The nonlinear optical parameters such as nonlinear absorption coefficient β eff (or β 2), the imaginary third-order susceptibility (Im[χ (3)]) and the imaginary part of second-order hyperpolarizability (γ) of the samples were evaluated using the open-aperture Z-scan technique with a laser pulse duration of 10 ns at 532 nm wavelength. The corresponding numerical values of these parameters were of 10−10, 10−11 and 10−32 order, respectively. Two-photon absorption was revealed to be the main driving physical mechanism in the nonlinear response. This suggests that laccaic acid dye can be a potential candidate for NLO materials application

Les peptides antimicrobiens d’origine microbienne: cas des bactériocines

Les bactéries à Gram positif et à Gram négatif et les archées produisent respectivement des bactériocines et des archéocines. Les bactériocines et les archéocines sont des peptides antimicrobiens. Au fil des ans leur rôle dans la sûreté des produits alimentaires n’a cessé d’être démontré, faisant de ces peptides naturels un centre d’intérêt pour la recherche scientifique. Cette revue tente de faire l’état des connaissances sur les bactériocines produites par les bactéries Gram positif, bactéries Gram négatif et les archées en faisant ressortir leurs organisations génétiques particulières, leurs modes d’action qui diffèrent de celui des antibiotiques et surtout leurs larges spectres d’action. La collecte des données a consisté à consulter les articles scientifiques publiés et les mémoires de thèses sur les différents travaux menés sur les bactériocines et disponible en ligne via les journaux de publication et les sites dédiés aux collectes de thèses en ligne. Ces peptides antimicrobiens pourraient constituer une alternative pour la conservation des denrées alimentaires surtout en milieu rural dans les pays en voie de développement.© 2016 International Formulae Group. All rights reserved.Mots clés: bactériocines, bactéries, archéocines, archées, antimicrobiens, agro alimentaireEnglish Title: Antimicrobial peptides from microbes: case of bacteriocinsEnglish AbstractGram-positive and Gram-negative bacteria and Archaea respectively produce bacteriocins and archeocins. Over the years, their role in the food safety has continued rising because of the report of many works. This review focuses on bacteriocins know up to date by highlighting on their particular genetic organization, their mode of action that differs from antibiotics and especially their broad spectrum of action. Data were collected by consulting online available published scientific articles and thesis on bacteriocins and archeocins. These antimicrobial peptides could provide an alternative for preserving foodstuffs especially in rural areas in developing countries.© 2016 International Formulae Group. All rights reserved.Keywords: Bacteriocins; bacteria; archeocins, archea, antimicrobial activity, agribusines

Economic Valuation of Ecosystem Services in Sahel's Wetlands: Case of Bourgou (Echinochloa stagnina) in the Inner Niger Delta

The Inner Niger Delta (IND) located in Mali provides several ecosystem services to Sahelian people. Among these services, the bourgou fields (Echinochloa stagnina) have a very high value for inhabitants' livelihood and biodiversity. The main objective of this study is to assess the economic value of bourgou ecosystem services in the IND. Specific objectives are to analyze ecosystem services from Echinochloa stagnina and the benefit-cost of its regeneration (plantation) in the IND. The adopted methodology is based on market price and benefit-cost approaches through analysis of collected data from conducted inhabitants' surveys in the circle of Youwarou located in Mali center. The findings show that each Bourgou producer farms on average 7 hectares that provide fish, pasture, livelihoods, and habitats for biodiversity as ecosystem services. The revenue received by bourgou producers with payment for access to pasture for 89,347 cattle is estimated at USD 150,674.78 (47,085,869 FCFA). The benefit of ecosystem services from bourgou is USD/ha 999.22 (312,257 FCFA/ha). To restore bourgou fields, 98.5% of producers are willing to pay USD 192.07 (60,023 FCFA) for it to improve seeds of 1 hectare cultivation. The bourgou culture is a green financing opportunity for income generation, ecosystem services restoration, and biodiversity conservation. Keywords: Bourgou, Biodiversity, Ecosystem services, Income, Inner Niger Delta DOI: 10.7176/JESD/14-17-03 Publication date: November 30th 202

Different methodological approaches to the assessment of in vivo efficacy of three artemisinin-based combination antimalarial treatments for the treatment of uncomplicated falciparum malaria in African children.

BACKGROUND: Use of different methods for assessing the efficacy of artemisinin-based combination antimalarial treatments (ACTs) will result in different estimates being reported, with implications for changes in treatment policy. METHODS: Data from different in vivo studies of ACT treatment of uncomplicated falciparum malaria were combined in a single database. Efficacy at day 28 corrected by PCR genotyping was estimated using four methods. In the first two methods, failure rates were calculated as proportions with either (1a) reinfections excluded from the analysis (standard WHO per-protocol analysis) or (1b) reinfections considered as treatment successes. In the second two methods, failure rates were estimated using the Kaplan-Meier product limit formula using either (2a) WHO (2001) definitions of failure, or (2b) failure defined using parasitological criteria only. RESULTS: Data analysed represented 2926 patients from 17 studies in nine African countries. Three ACTs were studied: artesunate-amodiaquine (AS+AQ, N = 1702), artesunate-sulphadoxine-pyrimethamine (AS+SP, N = 706) and artemether-lumefantrine (AL, N = 518).Using method (1a), the day 28 failure rates ranged from 0% to 39.3% for AS+AQ treatment, from 1.0% to 33.3% for AS+SP treatment and from 0% to 3.3% for AL treatment. The median [range] difference in point estimates between method 1a (reference) and the others were: (i) method 1b = 1.3% [0 to 24.8], (ii) method 2a = 1.1% [0 to 21.5], and (iii) method 2b = 0% [-38 to 19.3].The standard per-protocol method (1a) tended to overestimate the risk of failure when compared to alternative methods using the same endpoint definitions (methods 1b and 2a). It either overestimated or underestimated the risk when endpoints based on parasitological rather than clinical criteria were applied. The standard method was also associated with a 34% reduction in the number of patients evaluated compared to the number of patients enrolled. Only 2% of the sample size was lost when failures were classified on the first day of parasite recurrence and survival analytical methods were used. CONCLUSION: The primary purpose of an in vivo study should be to provide a precise estimate of the risk of antimalarial treatment failure due to drug resistance. Use of survival analysis is the most appropriate way to estimate failure rates with parasitological recurrence classified as treatment failure on the day it occurs

Prevalence of Escherichia coli virulence genes in patients with diarrhoea in Ouagadougou, Burkina Faso

Objective: Diarrhoeagenic E. coli (DEC) strains are important causes of diarrhoea in the developing world and, to a lesser extent, inthe developed world. In this study, we investigated the prevalence of the virulence genes specific for five major pathogroups of diarrheagenic Escherichia coli (DEC) in primary cultures from diarrhoeagenic patients in Burkina Faso.Methodology: From September 2016 to Mars 2017, a total of 211 faecal samples from diarrhoeagenic patients from urban hospitals of Ouagadou, Burkina Faso have been analysed. A 16-plex PCR was used to detect simultaneously, the five major DEC pathotypes (enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), Shiga toxin-producing E. coli (STEC), enteroaggregative E. coli (EAEC) and enteroinvasive E. coli (EIEC)).Results: At least one diarrhoeagenic E. Coli pathotype was detected in 31 samples (14.7%) in children and adults with diarrhoea. EAEC was the most common pathotype detected 9.5% (20/211), followed by EIEC2.4% (05/211) and STEC 0.5% (01/211). More than one DEC pathotype were detected in 2.4% (05/211) patients. EPEC and ETEC were not detected in single infection but in co-infection with others pathotypes.Conclusion: DEC, especially enteroaggregative, may be important responsible of diarrhoeas in Burkina Faso from all ages patient.Key Words: Diarrhoeagenic Escherichia coli, 16-plex PCR, Burkina Faso, human diarrhoeas stool

Anopheline species composition and the 1014F-genotype in different ecological settings of Burkina Faso in relation to malaria transmission

Background: A three-year longitudinal study was conducted in four sentinel sites from different ecological settings in Burkina Faso, between 2008 and 2010 to identify longitudinal changes in insecticide resistance within Anopheles gambiae complex species based on larval collection. During this study, adult mosquitoes were also collected indoor and outdoor using several methods of collection. The present study reports the diversity of malaria vectors and the 1014F-genotype from this adult collection and investigates the association between this 1014F-genotype and sporozoite rate. Methods: Adult mosquitoes were collected from July to August (corresponding to the start of rainy season) and October to November (corresponding to the end of rainy season) over 3 years (2008–2010) at four sites across the country, using pyrethrum spray catches (PSC), exit traps and pit shelters. Anopheles gambiae complex mosquitoes were identified to species and genotyped for the L1014F kdr mutation by PCR using genomic DNA. The circumsporozoite antigen of Plasmodium falciparum was detected in mosquitoes using sandwich ELISA. Results: Overall 9212 anopheline mosquitoes were collected during the study period. Of those, 6767 mosquitoes were identified as Anopheles gambiae sensu lato (s.l.). Anopheles arabiensis, Anopheles coluzzii, Anopheles gambiae and or Anopheles funestus were incriminated as vectors of P. falciparum in the study area with an average sporozoite rate of 5%, (95% CI 4.14–5.99%). The kdr1014F-genotype frequencies were 11.44% (95% CI 2.5–39.85%), 19.2% (95% CI 4.53–53.73%) and 89.9 (95% CI 63.14–97.45%), respectively for An. arabiensis, An. coluzzii and An. gambiae. The proportion of the 1014F-genotype varied between sporozoite-infected and uninfected An. gambiae s.l. group. There was no significant difference in the 1014F-genotype frequency between infected and uninfected mosquitoes. Conclusion: The current study shows the diversity of malaria vectors and significant interaction between species composition and kdr1014F-genotype in An. gambiae complex mosquitoes from Burkina Faso. In this study, no associations were found between the 1014F-genotype and P. falciparum infection in the major malaria vector An. gambiae s.l

Galls of Guiera senegalensis J.F. GMEL (Combretaceae) as potential source of insecticides against the main cowpea pest Callosobruchus maculatus (Fab.) (Coleoptera: Bruchidae) detoxification enzymes

The cowpea weevil, Callosobruchus maculatus (F.), is a major pest of cowpea ( Vigna unguiculata (L.) Walp.) in storage. A laboratory study was conducted to investigate the inhibition potential of Guiera senegalensis galls on C. maculatus detoxification enzymes. Methanol extract from galls of G. senegalensis exhibited strong inhibitory effects of the activity of C. maculatus acetylcholinesterase (AChE) and mixed-functional oxidase enzymes. The chemical composition of the extracted oils was examined by gas chromatograph (GC)-flame ionisation detectors (FID) and mass spectrometry. Twelve components were identified, namely 2-Hydroxy-4-methoxybenzophenone, n-Pentadecane, Octadecane, 1,2-Benzenedicarboxylic acid, dibutyl ester, Palmitic Acid, Hexadecane, Cis-vaccenic acid, Oleyl alcohol, stenol, n-Eicosane, n-Heneicosane and vincubine. This plant could be used for improving the efficacy to various insecticide classes against C. maculatus and as an alternative to synthetic insecticides.Callosobruchus maculatus (F.) est un ravageur majeur des graines du ni\ue9b\ue9 ( Vigna unguiculata (L.) Walp) en stock. Une \ue9tude de laboratoire a \ue9t\ue9 conduite pour investiguer le potentiel d\u2019inhibition des galles de Guiera senegalensis sur le syst\ue8me de d\ue9toxification enzymatique de C. maculatus. L\u2019extrait m\ue9thanolique de G. senegalensis a montr\ue9 de fort effet inhibiteur sur l\u2019activit\ue9 enzymatique de l\u2019ac\ue9tylcholinest\ue9rase (AChE) et des oxydases \ue0 fonction mixte. La composition chimique de l\u2019huile extraite a \ue9t\ue9 examin\ue9e par chromatographie en phase gazeuse coupl\ue9e \ue0 un d\ue9tecteur \ue0 ionisation de flamme (GC-FID) et par spectrom\ue9trie de masse. Douze (12) compos\ue9s ont \ue9t\ue9 identifi\ue9s, \ue0 savoir 2-Hydroxy-4-methoxybenzophenone, n-Pentad\ue9cane, Octad\ue9cane, benz\ue8ne-1,2-dicarboxylate de dibutyle, Acide Palmitique, Hexad\ue9cane, Acide Cis-vaccinique, Alcool ol\ue9ylique, st\ue9nol, n-Eicosane, n-H\ue9nicosane et la vincubine. Cette plante pourrait \ueatre utilis\ue9e pour am\ue9liorer l\u2019efficacit\ue9 de diverses classes d\u2019insecticides contre C. maculatus et comme alternative aux insecticides de synth\ue8s

Nonlinear optical properties of poly (methyl methacrylate) thin films doped with Bixa Orellana dye

Natural dyes with highly delocalized π-electron systems are considered as promising organic materials for nonlinear optical applications. Among these dyes, Bixa Orellana dye with extended π-electron delocalization is one of the most attractive dyes. Bixa Orellana dye-doped Poly(methyl methacrylate) (PMMA) thin films were prepared through spin coating process for linear and nonlinear optical properties investigation. Atomic force microscopy (AFM) was used to evaluate the roughness of the thin films. The optical constants n and k were evaluated by ellipsometric spectroscopy. The refractive index had a maximum of about 1.456 at 508.5, 523.79 and 511.9 nm, while the maximum of k varies from 0.070 to 0.080 with the thickness. The third order nonlinear optical properties of the hybrid Bixa Orellana dye-PMMA polymer were investigated under 30 ps laser irradiation at 1064 nm with a repetition rate of 10 Hz. In particular the third-order nonlinear susceptibility has been determined by means of the Maker Fringes technique. The nonlinear third order susceptibility was found to be 1.00 × 10−21 m2 V−2 or 0.72 × 10−13 esu. Our studies provide concrete evidence that the hybrid-PMMA composites of Bixa dye are prospective candidates for nonlinear material applications