Composition chimique d’un extrait aqueux de bridelia ferruginea benth. (euphorbiaceae) et études de ses effets toxicologique et pharmacologique chez les mammifères.

La caractérisation des constituants chimiques de l’extrait aqueux de Bridelia ferruginea (SEA) a révélé la présence de quinones, de tanins catéchiques et galliques, d’alcaloïdes, de stérols, de polyterpènes, de polyphénols, de composés réducteurs, de flavonoïdes et de saponosides.L’étude de la toxicité aiguë de SEA, réalisée sur des souris, a montré que l’extrait aqueux de Bridelia ferruginea administré par voie orale est modérément toxique (DL50 égale à 3568,88 ± 308,45 mg/kg PC). En revanche, la même substance est très toxique (DL50 égale à 111,38 ± 29,3 mg/kg PC) lorsqu’elle est administrée par voie intrapéritonéale. Pour des doses comprises entre 5.10-3 g/kg de PC et 4.10-2 g/kg de PC, SEA provoque une hypotension dose-dépendante chez le lapin. Cette hypotension étant inhibée par l’atropine, l’extrait aqueux de Bridelia ferruginea contiendrait probablement des substances cholinomimétiques de type muscarinique.Mots-clés : Bridelia ferruginea, toxicologie, phytochimie, pharmacologie

Etudes phytochimique et pharmacologique de Bridelia ferruginea benth (euphorbiaceae) sur la motricite du Taenia coli de cobaye

L’étude phytochimique des extraits de Bridelia ferruginea a montré que cette plante contient des quinones, des tanins catéchiques et galliques, des alcaloïdes, des stérols, des polyterpènes, des polyphénols, des composés réducteurs, des flavonoïdes et des saponosides. L’extrait aqueux de Bridelia ferruginea provoque entre 10-5mg/mL et 10-1mg/mL une augmentation des contractions rythmiques de muscle lisse Taenia coli de cobaye. Ces effets inotropes positifs antagonisés par l’Atropine (10-6mg/mL) sont totalement abolis en milieu pauvre (0Ca2+) et dépourvus de calcium (0Ca2++ EDTA 10-5M).Ces résultats suggèrent la présence de substances cholinomimétiques dans l’extrait brut. Ces substances favoriseraient l’entrée de calcium dans la cellule musculaire lisse par stimulation des récepteurs muscariniques. Ces substances cholinomimétiques justifieraient l’usage traditionnel de cette plante comme laxatif ou purgatif.Mots-clés : Bridelia ferruginea, Taenia coli, récepteur muscarinique.

Forms and exchangeability of inorganic phosphate in composted solid organic wastes

Switzerland yearly produces more than 260,000 Mg of compost, two thirds of which is recycled in agriculture and horticulture. This research was undertaken to examine the forms and availability of inorganic P (Pi) in Swiss composts made from solid kitchen and garden wastes using the isotopic exchange kinetic technique, a sequential Pi extraction and magic angle spinning (MAS) solid-state 31P nuclear magnetic resonance (NMR) spectroscopy. The different approaches described in this paper demonstrate the presence of a complex mixture of Pi species in the studied composts. Isotopic exchange experiments and sequential extraction showed that these composts contained relatively large concentrations of rapidly available Pi. Significant correlations were observed between the concentration of water-soluble Pi (Cp), and the total N, C and P content of composts suggesting that organic substances partly controlled the amount of rapidly available Pi. Significant correlations were observed in alkaline composts between the amount of Pi which can not be exchanged within 3 months and the total P and Ca content. In alkaline composts solid-state MAS 31P NMR results suggested the presence of a range of slightly soluble and poorly crystallized Ca-P compounds such as apatites or octacalcium phosphates and of organic P compounds. The slowly or non-exchangeable Pi present in these composts could therefore be bound to Ca in the form of apatites or octacalcium phosphate

Acetylcholinesterase (ace‑1R) target site mutation G119S and resistance to carbamates in Anopheles gambiae (sensu lato) populations from Mali

Open Access Journal; Published online: 05 Jun 2020Background The long-lasting insecticidal nets (LLINs) and indoor residual spraying of insecticide (IRS) are major malaria vector control strategies in Mali. The success of control strategies depends on a better understanding of the status of malaria vectors with respect to the insecticides used. In this study we evaluate the level of resistance of Anopheles gambiae (sensu lato) to bendiocarb and the molecular mechanism that underlies it. Methods Larvae of An. gambiae (s.l.) were collected from breeding habitats encountered in the three study sites and bioassayed with bendiocarb. The ace-1 target site substitution G119S was genotyped using a TaqMan assay. Results The three species of the An. gambiae complex in Mali, i.e. An. arabiensis, An. coluzzii and An. gambiae (s.s.) were found in sympatry in the three surveyed localities with different frequencies. We observed a resistance and suspicious resistance of the three species to bendiocarb with a mortality rate ranging from 37% to 86%. The allelic frequency of the G119S mutation was higher in An. gambiae (s.s.) compared to the other two species; 42.86%, 25.61% and 16.67% respectively in Dangassa, Koula, and Karadié. The allelic frequency of G119S in An. coluzzii ranged from 4.5% to 8.33% and from 1.43% to 21.15% for An. arabiensis. After exposure to bendiocarb, the G119S mutation was found only in survivors. The survival of Anopheles gambiae (s.l) populations from the three surveyed localities was associated with the presence of the mutation. Conclusions The study highlights the implication of G119S mutation in bendiocarb resistance in An. gambiae (s.s.), An. arabiensis and An. coluzzii populations from the three surveyed localities

Evaluation of the diagnostic performance and operational characteristics of four rapid immunochromatographic syphilis tests in Burkina Faso

Background and objective: Little information is available on the rapid diagnostic testing for syphilis in Burkina Faso. The objectives of the study were (i) to assess the sensitivity and specificity of four on site rapid tests in comparison with Treponema pallidum haemagglutination assay (TPHA) as a gold standard and (ii) to evaluate the operational characteristics of those tests among health workers in a maternity unit.Methods: Four rapid syphilis tests commercially available in Burkina Faso were evaluated using archived serum samples and Treponema pallidum hemagglutination assay (TPHA) as the gold standard. Blood samples were collected between November 2011 and June 2012 from blood donors at the Regional Blood Transfusion Center of Ouagadougou. The sensitivity and specificity of the tests were calculated. Evaluation of operational characteristics such as clarity of pamphlet, complexity of technique, duration, was conducted in a first-level healthcare center with health workers in maternity unit.Results: Alere DetermineTM Syphilis was the most sensitive of the four rapid syphilis tests evaluated. It was followed by SD Bioline Syphilis 3.0, Cypress Diagnostics Syphilis Quick test and Accu-Tell ® Rapid Anti-TP, which was the least sensitive. The four tests demonstrated a good diagnostic specificity for syphilis (95–98%), and healthcare workers found them easy to use.Conclusions: The study allowed confirming the good performance of three of four rapid syphilis tests in Burkina Faso. More research will be conducted to assess the feasibility of introducing selected rapid tests for syphilis in antenatal care services.Keywords: syphilis, rapid test, performance, Burkina Fas

Comparative Evaluation of Action Recognition Methods via Riemannian Manifolds, Fisher Vectors and GMMs: Ideal and Challenging Conditions

We present a comparative evaluation of various techniques for action recognition while keeping as many variables as possible controlled. We employ two categories of Riemannian manifolds: symmetric positive definite matrices and linear subspaces. For both categories we use their corresponding nearest neighbour classifiers, kernels, and recent kernelised sparse representations. We compare against traditional action recognition techniques based on Gaussian mixture models and Fisher vectors (FVs). We evaluate these action recognition techniques under ideal conditions, as well as their sensitivity in more challenging conditions (variations in scale and translation). Despite recent advancements for handling manifolds, manifold based techniques obtain the lowest performance and their kernel representations are more unstable in the presence of challenging conditions. The FV approach obtains the highest accuracy under ideal conditions. Moreover, FV best deals with moderate scale and translation changes

Mineral fertilisation by microdose: Incentives for widespread adoption in Burkina Faso

Mineral fertilisation by microdosing has been tested in Burkina Faso since 2000 to increase the agricultural productivity of small farmers. In order to identify the determinants of its adoption, data were collected from a random sample of 180 women and 440 men in the provinces of Zondoma and Kourittenga in Burkina Faso; where the innovation was disseminated. The results of the Logit model showed that the determinants of adoption varied according to gender and production area. In Kourittenga, warrantage (inventory credit system) system determined the choice by women, whereas that by men depended on warrantage and dissemination tools. In Zondoma, in addition to access to information on mineral fertilisation by microdosing on which the choices of each type of farmer were dependent, education level and belonging to a farmer organisation determined the choice of men and women, respectively. These results challenged policy decision makers to strengthen socio-economic and institutional capacities for effective adoption of mineral fertilisation microdosing technique in order to sustainably improve the food situation of Sahelian small farmers.La fertilisation min\ue9rale par microdose a \ue9t\ue9 test\ue9e au Burkina Faso depuis 2000 en vue d\u2019accroitre la productivit\ue9 agricole des petits producteurs. Afin de promouvoir son adoption \ue0 grande \ue9chelle, des informations ont \ue9t\ue9 collect\ue9es aupr\ue8s d\u2019un \ue9chantillon de 180 femmes et 440 hommes choisis de fa\ue7on al\ue9atoire dans les provinces du Zondoma et du Kourittenga o\uf9 l\u2019innovation a \ue9t\ue9 diffus\ue9e afin d\u2019identifier les d\ue9terminants de son adoption. Les r\ue9sultats du mod\ue8le Logit indiquent que les d\ue9terminants d\u2019adoption varient partiellement selon le genre et les zones. Au Kourittenga, le warrantage d\ue9termine le choix des femmes or celui des hommes d\ue9pend \ue0 la fois du warrantage et des outils de diss\ue9mination. Au Zondoma, en plus de l\u2019acc\ue8s \ue0 l\u2019information, d\ue9terminant chez les deux types de producteur, le niveau d\u2019instruction et l\u2019appartenance \ue0 une organisation paysanne d\ue9terminent respectivement le choix des hommes et des femmes. Ces r\ue9sultats interpellent les d\ue9cideurs politiques \ue0 un renforcement des capacit\ue9s socio-\ue9conomiques et institutionnelles pour une adoption effective de la microdose afin d\u2019am\ue9liorer durablement la situation alimentaire des producteurs sah\ue9liens

Increasing the productivity of sorghum farmers in the Sudan Savannah of Nigeria: Effect of access to improved technology and market

Sorghum has assumed greater importance in the economies of several African countries especially with the renewed interest by processors who are interested in using the grain to compliment/substitute wheat and barley in the confectionery and malting industries. Low on-farm grain yields are attributed to low use of inputs including seeds and fertilizers as well as good agronomic practices. ICRISAT Nigeria, in collaboration with several partners under the Agricultural Transformation Support Project (ATASP-1) implemented several activities including thematic training, on-farm technology demonstrations, community seed production and formation of innovation platforms (IPs) for market linkages. Remarkable progress were made in enhancing access to quality seeds and other inputs to over 40,000 farmers while expanding knowledge of Improved technologies to over 100 communities. During the 2016 cropping season, farmers produced over 70,268 Mt of grains valued at N9.135billion (US$29M). The impacts of trainings resulted in about 60% improvement in the understanding of good agronomic practices and post-harvest handling by the farmers and extension agents. The use of improved technologies increased grain yields by 30 to 64% (improved varieties), 27 to 38% (seed dressing), and 20% to 55% (tillage practices). Through IPs and market linkages to large scale processors, 109.76 tons of seeds were procured, distributed and planted. Average yield obtained from improved technologies was 1.5 t/ha compared to 1.1 t/ha by other farmers giving a 40% increase. A total of 1,093 women farmers comprising of about 34.2% of the total number of participating farmers benefited directly from the project. Seed fairs, radios and audio-visual broadcasts on improved production technologies and market availability were used to reach non-participating farmers within the zones. The combination of methods stimulated adoption of improved sorghum production technologies and market linkages proofed effective in achieving both increased sorghum yields and household income