Koffi G.Y.,Toulouse 1 University Capitole |
Remaud-Simeon M.,Toulouse 1 University Capitole |
Due A.E.,Nangui Abrogoua University |
Combes D.,Toulouse 1 University Capitole
Food Chemistry | Year: 2017
The estimation of glycoalkaloids in the flesh of different types of decayed potatoes was evaluated. The results showed that turned green and also sprouting or rotting potato flesh contain high amounts of toxic solanine and chaconine, exceeding by 2–5-fold the recommended limit, and ranging from 2578 ± 86 mg/kg to 5063 ± 230 mg/kg of dry weight potato flesh. For safety consideration, these decayed potatoes should be systematically set aside. To avoid a net economic loss and encourage the removal of this hazardous food, a recycling process was investigated to generate added-value compounds from the toxic glycoalkaloids. A simple chemo-enzymatic protocol comprising a partial acidic hydrolysis followed by an enzymatic treatment with the β-glycosidase from Periplaneta americana allowed the efficient conversion of α-chaconine to solanidine. © 2016 Elsevier Ltd
Rtibi D.,Tunis el Manar University |
Boa D.,Nangui Abrogoua University |
Hellali D.,Tunis el Manar University |
Zamali H.,Tunis el Manar University
Journal of Alloys and Compounds | Year: 2017
The phase diagram of the binary system (KNO3+TlNO3) was studied using simultaneous simple and differential thermal analysis (STA/DTA), differential scanning calorimetry (DSC) and X-Ray Diffraction (XRD) techniques. This phase diagram is characterized by four invariants: a eutectic at 457 K, two eutectoids at 409 K and 382 K and a peritectoid at 352 K. An optimization of this binary system based on the available experimental data is also presented in this work. © 2017 Elsevier B.V.
Kouassi K.A.,Nangui Abrogoua University |
Dadie A.T.,Nangui Abrogoua University |
N'Guessan K.F.,Nangui Abrogoua University |
Dje K.M.,Nangui Abrogoua University |
Loukou Y.G.,Félix Houphouët-Boigny University
Anaerobe | Year: 2014
The aim of this study was to evaluate the prevalence of Clostridium difficile and Clostridium perfringens in cooked beef sold in the streets in CÔte d'Ivoire and their antimicrobial susceptibility. A total of 395 kidney and flesh samples of cooked beef were collected from vendors at Abidjan and subjected to C.difficile and C.perfringens isolation and identification by using biochemical tests, API 20A system and PCR detection. Subsequently, the antimicrobial susceptibility test was performed for confirmed isolates. Our results showed the prevalence of 12.4% for C.difficile (11.04% in kidney and 13.45% in flesh) and 5.06% for C.perfringens (2.32% in kidney and 7.17% in flesh). Metronidazole and vancomycin remained the most potent antimicrobial agents against C.difficile while metronidazole and penicillin G were the most potent agents against C.perfringens. The resistance rates to tetracycline, doxycycline, chloramphenicol and erythromycin against C.difficile and C.perfringens isolates ranged from 2.05% to 8.16% and from 20% to 50%, respectively. Among all antimicrobial agents tested against C.difficile, percentages of resistance to quinolones ciprofloxacin, norfloxacin and nalidixic acid as well as to gentamicin and cefotaxime were the highest. Eight resistant phenotypes were defined for C.difficile isolates and eleven resistant phenotypes for C.perfringens isolates. Clindamycin/gentamicin/cefotaxime/ciprofloxacin/norfloxacin/nalidixic acid resistance was the most common phenotype for C.difficile (55.10% of isolates) while norfloxacin/nalidixic acid resistance was the most common phenotype for C.perfringens (20% of isolates). © 2014 The Authors.
Edi C.V.,Center Suisse Of Recherches Scientifiques En Cote Divoire |
Djogbenou L.,University Abomey Calavi |
Jenkins A.M.,Boston College |
Regna K.,Boston College |
And 6 more authors.
PLoS Genetics | Year: 2014
Malaria control relies heavily on pyrethroid insecticides, to which susceptibility is declining in Anopheles mosquitoes. To combat pyrethroid resistance, application of alternative insecticides is advocated for indoor residual spraying (IRS), and carbamates are increasingly important. Emergence of a very strong carbamate resistance phenotype in Anopheles gambiae from Tiassalé, Côte d'Ivoire, West Africa, is therefore a potentially major operational challenge, particularly because these malaria vectors now exhibit resistance to multiple insecticide classes. We investigated the genetic basis of resistance to the most commonly-applied carbamate, bendiocarb, in An. gambiae from Tiassalé. Geographically-replicated whole genome microarray experiments identified elevated P450 enzyme expression as associated with bendiocarb resistance, most notably genes from the CYP6 subfamily. P450s were further implicated in resistance phenotypes by induction of significantly elevated mortality to bendiocarb by the synergist piperonyl butoxide (PBO), which also enhanced the action of pyrethroids and an organophosphate. CYP6P3 and especially CYP6M2 produced bendiocarb resistance via transgenic expression in Drosophila in addition to pyrethroid resistance for both genes, and DDT resistance for CYP6M2 expression. CYP6M2 can thus cause resistance to three distinct classes of insecticide although the biochemical mechanism for carbamates is unclear because, in contrast to CYP6P3, recombinant CYP6M2 did not metabolise bendiocarb in vitro. Strongly bendiocarb resistant mosquitoes also displayed elevated expression of the acetylcholinesterase ACE-1 gene, arising at least in part from gene duplication, which confers a survival advantage to carriers of additional copies of resistant ACE-1 G119S alleles. Our results are alarming for vector-based malaria control. Extreme carbamate resistance in Tiassalé An. gambiae results from coupling of over-expressed target site allelic variants with heightened CYP6 P450 expression, which also provides resistance across contrasting insecticides. Mosquito populations displaying such a diverse basis of extreme and cross-resistance are likely to be unresponsive to standard insecticide resistance management practices. © 2014 Edi et al.
Kassi S.-P.A.Y.,Nangui Abrogoua University |
Kone A.W.,Nangui Abrogoua University |
Tondoh J.E.,Nangui Abrogoua University |
Koffi B.Y.,Nangui Abrogoua University
Agriculture, Ecosystems and Environment | Year: 2017
Natural ecosystem conversion to agriculture is known to alter soil carbon dynamic. Following such conversion in many tropical areas, land undergoes fallow-cropping cycles where fallows are invaded by the pantropical weed Chromoleana odorata. This study was undertaken in the forest-savanna interface area of Côte d'Ivoire to evaluate the impact of these cycles on soil carbon stocks (SOCS) and yam yields, decades after natural ecosystem conversion. Trials involved four treatments including yam farms in forest (FOR, n = 10), in forest-derived C. odorata fallows (FoDCo, n = 7), in savanna (SAV, n = 3) and in savanna-derived C. odorata fallows (SaDCo, n = 3). Prior to turning plots to farms, soil was sampled in the 0–10, 10–20 and 20–40 cm layers for physical, chemical and microbial parameters. Since forest and savanna soils were different in granulometry, FoDCo was compared to FOR, and SaDCo to SAV. The soil organic matter and nutrient concentrations in the 0–10 cm soil layer in FoDCo and FOR were similar, except for available P which was higher in the former. SaDCo was higher than SAV in terms of SOC, available P, mineral N, and NO3-N:Mineral N ratio. With regard to SOCS, value in FoDCo equalled that in FOR regardless of soil layers (63.2 ± 4.4 and 63.7 ± 4.6 Mg ha−1 in 0–40 cm layer, respectively). However, SOCS significantly increased in SaDCo relative to SAV in the 0–20 cm (31.4 ± 2.7 vs. 24.2 ± 2.1 Mg ha−1). Consistently, yam yield in FoDCo was like that in FOR while it doubled in SaDCo compared to SAV, with SOC, CEC and mineral N as the controlling factors. The major finding of this study is that the predominance of C. odorata in fallow phases allows at least for maintenance of SOCS and yam yields decades after natural ecosystem conversion to farmland. Furthermore, evidence of the feasibility of the “4 per mille” was given. These results are highly useful in forest protection strategies since farmers usually cut forest for yam cropping. © 2017 Elsevier B.V.
Otani S.,Copenhagen University |
Mikaelyan A.,Max Planck Institute for Terrestrial Microbiology |
Nobre T.,University of Évora |
Hansen L.H.,University of Aarhus |
And 6 more authors.
Molecular Ecology | Year: 2014
Gut microbes play a crucial role in decomposing lignocellulose to fuel termite societies, with protists in the lower termites and prokaryotes in the higher termites providing these services. However, a single basal subfamily of the higher termites, the Macrotermitinae, also domesticated a plant biomass-degrading fungus (Termitomyces), and how this symbiont acquisition has affected the fungus-growing termite gut microbiota has remained unclear. The objective of our study was to compare the intestinal bacterial communities of five genera (nine species) of fungus-growing termites to establish whether or not an ancestral core microbiota has been maintained and characterizes extant lineages. Using 454-pyrosequencing of the 16S rRNA gene, we show that gut communities have representatives of 26 bacterial phyla and are dominated by Firmicutes, Bacteroidetes, Spirochaetes, Proteobacteria and Synergistetes. A set of 42 genus-level taxa was present in all termite species and accounted for 56-68% of the species-specific reads. Gut communities of termites from the same genus were more similar than distantly related species, suggesting that phylogenetic ancestry matters, possibly in connection with specific termite genus-level ecological niches. Finally, we show that gut communities of fungus-growing termites are similar to cockroaches, both at the bacterial phylum level and in a comparison of the core Macrotermitinae taxa abundances with representative cockroach, lower termite and higher nonfungus-growing termites. These results suggest that the obligate association with Termitomyces has forced the bacterial gut communities of the fungus-growing termites towards a relatively uniform composition with higher similarity to their omnivorous relatives than to more closely related termites. © 2014 John Wiley & Sons Ltd.
Boly V.,CNRS Research team on Innovative Processes |
Morel L.,CNRS Research team on Innovative Processes |
Assielou N.G.,Nangui Abrogoua University |
Camargo M.,CNRS Research team on Innovative Processes
Research Policy | Year: 2014
Measuring innovation processes is a major concern for academics and firm managers. This study proposes an innovation capacity (IC) measure framework based on a set of 15 innovation management practices. Every practice is subdivided into multiple criteria which are directly observable phenomena or facts. The statistical method of value test and a multi-criteria approach are adopted to propose a typology of four groups of innovative firms (proactive, preactive, reactive, passive). The features observed on these groups of firms allow the determination of the firms' innovation capacity and are useful for providing recommendations and practical actions for them, with a view to reinforcing it. Data from a sample group of 39 small and medium sized enterprises (SMEs) in the manufacturing industry in Lorraine, France were collected via a field survey and were fed into the model to determine the innovation capacity of the companies. © 2013 Elsevier B.V. All rights reserved.
Kouassi K.I.,Ecole Normale Superieure de Paris |
Barot S.,Ecole Normale Superieure de Paris |
Laossi K.-R.,Nestlé |
Gignoux J.,Ecole Normale Superieure de Paris |
Zoro Bi I.A.,Nangui Abrogoua University
Forest Ecology and Management | Year: 2014
Eremospatha macrocarpa and Laccosperma secundiflorum are two clonal rattan species: through vegetative reproduction each individual, i.e. each genet, may produce several stems that are linked to the same rhizome. To determine the impact of ramet harvest by local human populations in these species, we compared the demography of their ramets and studied the impact of the dynamics of their ramets on the demography of their genets. This also allowed a better analyze of their life-history and demography. Genets were classified in development stages. We counted for each genet the number of alive, new, dead and harvested ramets. We determined the impact of the number of ramets and changes in this number on the genet probability of survival, retrogression and recruitment. Ramet demography differed between the two rattan species. The average numbers of new, harvested and dead ramets are about two times higher in E. macrocarpa than in L. secundiflorum. Furthermore, ramet demography influenced genet demography in both species. The survival of adult genets in E. macrocarpa and juvenile genets in L. secundiflorum increased with the initial number of ramets (about 10% between the lower and higher ramet numbers). The genet probability of retrogression increased in L. secundiflorum and decreased in E. macrocarpa with the initial number of ramets. These results suggest the existence of some physiological integration between the ramets of the two rattan species which leads to some cooperation and competition between ramets, within a genet, and to the compensatory production of new ramets after harvest. Overall, for both species, the links between ramet and genet demography suggest that ramet harvest, at the present harvesting rate, is not detrimental to the studied rattan populations. © 2013 Elsevier B.V.
Azokou A.,Nangui Abrogoua University |
Kone M.W.,Nangui Abrogoua University |
Koudou B.G.,Nangui Abrogoua University |
Tra Bi H.F.,Nangui Abrogoua University
Journal of Vector Borne Diseases | Year: 2013
Background & objectives: Mosquitoes increased resistance to insecticides, and environmental concerns about the use of insecticides, pose a major challenge in the search for new molecules to deplete and incapacitate mosquito populations. Plants are the valuable source as practices consisting in exploiting plant materials as repellents, and are still in wide use throughout developing countries. The aim of the present study was to screen plants from Côte d'Ivoire for larvicidal activity against mosquitoes. Methods: Resistant and sensitive larvae (III and IV instar) of Anopheles gambiae and Culex quinquefasciatus were exposed to crude ethanol extracts (90%) of 45 plants and viability observed after 30 min, 6, 12 and 24 h postincubation. After partition of active extracts, each fraction (hexane and chloroform washed with NaCl 1%, tannins and aqueous) was tested using the same protocol at various concentrations (1000-31.2 ppm). Results: Of 49 extracts tested, 7 exhibited high potential (LC50 = 80 to 370 ppm) against resistant and sensitive III and IV instar larvae of An. gambiae and Cx. quinquefasciatus. These extracts were from Cissus populnea, Cochlospermum planchonii, Heliotropium indicum, Phyllanthus amarus, Vitex grandifolia and Alchornea cordifolia. However, three most active plant species (LC50 = 80-180 ppm) were Cs. populnea, Cm. planchonii and P. amarus. Their hexane and chloroform fractions showed high larvicidal activity. Conclusion: This study demonstrated that plants from Côte d'Ivoire have a real potential for malaria, yellow fever, filarial and dengue vector control. Those could be used as sources or provide lead compounds for the development of safe plant-based biocides.
Dagou S.,Nangui Abrogoua University |
Richard F.C.,North Dakota State University
Euphytica | Year: 2016
Kernel hardness is an important character directly associated with milling quality of hard wheat (Triticum aestivum L.). We studied the inheritance of kernel hardness with the near-infrared reflectance technique. Four segregating populations were developed from three crosses: Amidon/Grandin for population 1 at Prosper, ND; Grandin/Amidon for population 2 at Fargo, ND; Amidon/ND622 for populations 3 and 4 at Prosper, ND and Fargo, ND. Amidon has a relatively hard kernel, whereas Grandin and ND622 have satisfactory kernel hadrness for desirable milling characteristics. Populations were grown in augmented block field experiments in 1988 and 1989. Heritability estimates for kernel hardness obtained by regression of F4 on F3 lines in populations 1 and 2, were 0.28 and 0.21, respectively. The estimates for the same character obtained by regression of F5 on F4 lines in populations 3 and 4 were 0.45 and 0.52, respectively. The estimates of heritability were significant. Effects of locations on kernel hardness were not significantly different. Statistical analyses showed that heritability estimates for populations 4 and 2 were significantly different. Correlation coefficients on a plot basis indicated little or no association between grain protein concentration and kernel hardness. © 2016 Springer Science+Business Media Dordrecht