Introduction et évaluation de la traction monobovine avec le jouguet IRAD-BF à l'Ouest du Burkina Faso

Document riche en enseignement technique pour l'accroissement de la productivité de l'agriculture familiale à travers la mécanisation à traction animale afin de lutter contre la pauvreté en Afrique de l'Ouest.La mécanisation agricole à traction bibovine est bien développée à l'ouest du Burkina Faso. Mais la traction monobovine y est quasi inexistante. Une étude sur l'introduction et l'évaluation de cette technique avec un joug simple (IRAD-BF) a été conduite dans quatre villages (Sara, Founzan, Koumbia et Gomgélédougou) de la province du Tuy. La méthode entreprise a été une enquête initiale sur l'état des lieux, la conduite d'une expérimentation, puis un bilan. En effet, 10% des paysans ont l'expérience du monobœuf et seulement 3% pratiquent cette technique dans leurs exploitations. L'engouement pour la paire est dû au fait que la technique est devenue locale et courante dans la zone, et la plupart des producteurs ne connaissent que cela. Le matériel vulgarisé dans la zone est conçu pour la traction bibovine et non adapté à l'usage d'un seul bœuf. L'analyse des essais révèle que la moyenne des ratios des puissances de traction entre le mono et la bibovine donne une constante moyenne de PBB/PMB = 1,64 ou PMB/PBB = 0,62, qui varie en fonction de la force de résistance appliquée sur la charrue. Pour optimiser le travail au champ, le producteur gagne ainsi en travaillant avec un seul bœuf pour les travaux demandant moins d'effort de traction (semis, sarclage, scarifiage, labour et buttage légers). Ainsi, 95% des producteurs ont jugé la traction monobovine commode et facile à exécuter. 66% des producteurs ont trouvé que l'effort fournit par le monobœuf est adapté lorsque l'animal a un grand gabarit (PV ≥ 300kg) et bien dressé. 100% des producteurs consentent la nécessité et la complémentarité de la traction monobovine avec le jouguet (IRAD-BF ou local). On retiendra que pour une adoption durable de la traction monobovine dans l'Ouest du Burkina Faso, il est important de tenir compte des capacités financières des bénéficiaires, d'assurer la disponibilité et l'accessibilité des jouguets, et de mener d'autres études complémentaires sur des sujets spécifiques tels que le transport et le semis monobovin avec le jouguet etc. Il est également nécessaire de mener des campagnes de promotion à travers des canaux appropriés et accessibles aux communautés rurales

The effect of temperature and concentration on the corrosion inhibition of recycled aluminum alloy of 3-aminopropyltrimethoxysilane (APTMS)

This work investigated the adsorption properties of 3-aminopropyltrimethoxysilane on recycled aluminum alloy. The influence of deposition conditions, such as pH and temperature of the sol-gel solution and the deposit's crosslinking temperature, on the coating's protective properties was studied by potentiodynamic polarization and electrochemical impedance spectroscopy. With Fourier Fourier-transformed infra-red spectroscopy and scanning electron microscopy, the quality of the coating was analyzed. The polarization curves performed on the coating deposited at different pH and temperature values showed that a more compact coating was obtained at pH 4 – 6  with a depositing temperature of ~ 25 °C. The best crosslinking temperatures are between 100 and 140°C. The analysis of the evolution of the protective barrier properties under long-time immersion conditions by electrochemical impedance spectroscopy showed that the coating exhibits good corrosion performance, compared to the bare alloy,  at less than one week

SWV determination of glyphosate in Burkina Faso soils using carbon fiber microelectrode

This paper presents an evaluation using carbon fiber microelectrode (CFME) for the determination of glyphosate in soils from Burkina Faso treated with Glyphonet SL 360 by square wave voltammetry (SWV).The maximum intensity of the electrochemical response signal of  glyphosate has been optimized and conditions using a 0.2 M of phosphate buffer solution at pH 5.2 as supporting electrolyte and the SWV parameters frequency of 60 Hz, a scan increment of 10 mV and a pulse height of 60 mV. The limit of detection for glyphosate in the Glyphonet SL 360 formulation was 25 ìg L-1 while the quantification limit was 83 ìgL-1with a linear dynamic range up to 50 ìg L-1. In these conditions, a sequence of experiments led to recoveries in the range 88.5 to 102.3% for soil samples spiked with 50, 100 and 200 ìgL-1 of glyphosate with a standard deviation of 11.5, 4.2 and 2.3% respectively indicating the precision of the method. The optimized method was successfully applied to determine the residues of glyphosate in soils collected in the fields in two different dates from the application period.Keywords: Glyphosate, Glyphonet SL 360, carbon fiber microelectrode, square wave voltammetry, sensitivit

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

Sensitive and selective electrochemical analysis of methyl-parathion (MPT) and 4-nitrophenol (PNP) by a new type p-NiTSPc/p-PPD coated carbon fiber microelectrode

Abstract A novel modified carbon fiber microelectrode (CFME) was obtained by combination of tetrasulfonated nickel phtalocyanine (p-NiTSPc) electroformed film associated to para-phenylenediamine (p-PPD) electropolymerized outer-coating. The modified CFMEs where denoted C/p-NiTSPc and C/p-NiTSPc/p-PPD, respectively. These electrodes are dedicated to the organophosphates compounds (OPs) methyl-parathion (MPT) and para-nitrophenol (PNP). Our contribution shows that both OPs can be determined simultaneously on the unmodified and modified C/ p-NiTSPc CFMEs. A clear electrocatalytic activity towards both MPT and PNP redox process was observed, for the first time, in presence of p-NiTSPc. The obtained sensitivity for the C/p-NiTSPc CFME was 80 nA L mg À1 in the concentration range 0.01 to 10 mg/L with a detection limit of 40 mg/L. Also the combination of p-NiTSPc and p-PPD electrodeposited films show, for the first time, the possibility to discriminate on the C/p-NiTSPc/p-PPD CFME between MPT and PNP. Stability experiments were also conducted for 3 weeks in acetate buffer showing a good reproductibility of the sensitivity to PNP vs. time in presence of MPT with a little loss of sensitivity (5%) after 3 weeks

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

Pathotypic diversity of Hyaloperonospora brassicae collected from Brassica oleracea

Downy mildew caused by Hyaloperonospora brassicae is an economically destructive disease of brassica crops in many growing regions throughout the world. Specialised pathogenicity of downy mildews from different Brassica species and closely related ornamental or wild relatives has been described from host range studies. Pathotypic variation amongst Hyaloperonospora brassicae isolates from Brassica oleracea has also been described; however, a standard set of B. oleracea lines that could enable reproducible classification of H. brassicae pathotypes was poorly developed. For this purpose, we examined the use of eight genetically refined host lines derived from our previous collaborative work on downy mildew resistance as a differential set to characterise pathotypes in the European population of H. brassicae. Interaction phenotypes for each combination of isolate and host line were assessed following drop inoculation of cotyledons and a spectrum of seven phenotypes was observed based on the level of sporulation on cotyledons and visible host responses. Two host lines were resistant or moderately resistant to the entire collection of isolates, and another was universally susceptible. Five lines showed differential responses to the H. brassicae isolates. A minimum of six pathotypes and five major effect resistance genes are proposed to explain all of the observed interaction phenotypes. The B. oleracea lines from this study can be useful for monitoring pathotype frequencies in H. brassicae populations in the same or other vegetable growing regions, and to assess the potential durability of disease control from different combinations of the predicted downy mildew resistance genes

Cracking in asphalt materials

This chapter provides a comprehensive review of both laboratory characterization and modelling of bulk material fracture in asphalt mixtures. For the purpose of organization, this chapter is divided into a section on laboratory tests and a section on models. The laboratory characterization section is further subdivided on the basis of predominant loading conditions (monotonic vs. cyclic). The section on constitutive models is subdivided into two sections, the first one containing fracture mechanics based models for crack initiation and propagation that do not include material degradation due to cyclic loading conditions. The second section discusses phenomenological models that have been developed for crack growth through the use of dissipated energy and damage accumulation concepts. These latter models have the capability to simulate degradation of material capacity upon exceeding a threshold number of loading cycles.Peer ReviewedPostprint (author's final draft