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21.
N'Guessan R Darriet F Guillet P Carnevale P Traore-Lamizana M Corbel V Koffi AA Chandre F 《Medical and veterinary entomology》2003,17(1):19-25
Resistance to carbosulfan, a carbamate insecticide, was detected in field populations of the malaria vector mosquito Anopheles gambiae Giles (Diptera: Culicidae) from two ecologically contrasted localities near Bouaké, Ivory Coast: rural M'bé with predominantly M form of An. gambiae susceptible to pyrethroids; suburban Yaokoffikro with predominantly S form of An. gambiae highly resistant to pyrethroids (96% kdr). The discriminating concentration of 0.4% carbosulfan (i.e. double the LC100) was determined from bioassays with the susceptible An. gambiae Kisumu strain. Following exposure to the diagnostic dosage (0.4% carbosulfan for 1 h), mortality rates of female An. gambiae adults (reared from larvae collected from ricefields) were 62% and 29% of those from M'bé and Yaokoffikro, respectively, 24 h post-exposure. Exposure for 3 min to netting impregnated with the operational dosage of carbosulfan 200 mg/m2 gave mortality rates of 88% of those from M'bé and only 12.2% for Yaokoffikro. In each case the control untreated mortality rate was insignificant. Biochemical assays to detect possible resistance mechanism(s) revealed the presence of insensitive AChE in populations of An. gambiae at both localities, more prevalent in the S form at Yaokoffikro than in M form at M'bé, as expected from bioassays results. Our study demonstrates the need to monitor carbamate resistance among populations of the An. gambiae complex in Africa, to determine its spread and anticipate vector control failure if these insecticides are employed. 相似文献
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Human African trypanosomiasis, or sleeping sickness, is still a worrying problem in Africa. Sleeping sickness is a disease for which a systematic monitoring is necessary, particularly for the trypanosomiasis caused by Trypanosoma brucei gambiense, which is characterized by a long asymptomatic stage. In the absence of specific clinical signs, mass screening of populations remains the only way to control the disease and to avoid its spreading. The lack of sensitivity and specificity of the diagnosis tests classically used led to the development of molecular tools. PCR amplification of parasite specific sequences has considerably improved the diagnostic of the parasitic infection, the stage diagnosis as well as the post-therapeutic follow-up. But there are limits with a use in routine and research is still necessary to make PCR a real tool for control of sleeping sickness. 相似文献
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Honoré G. Ouattara Ban L. Koffi Germain T. Karou Abdourahamane Sangaré Sebastien L. Niamke Jacques K. Diopoh 《World journal of microbiology & biotechnology》2008,24(9):1753-1760
The role of bacilli in cocoa fermentation is not well known. Their potential of production of pectinolytic enzymes during
this process was evaluated. Bacillus growth was monitored and pectinolytic strains were screened for their use of pectin as sole carbon source. Effects of cocoa
fermentation parameters susceptible to influence on enzyme production were analysed. Among 98 strains isolated, 90 were positive
for pectin degradation and 80% of them presented detectable pectinolytic activities in submerged fermentation. Forty-eight
strains produced polygalacturonase (PG), 47 yielded pectin lyase (PL) and 23 strains produced both enzymes. Bacilli growth
was not significantly affected during fermentation. PL production was favoured by galactose, lactose, glucose as sugars, and
arginine, glutamine, cysteine and ammonium sulphate as nitrogen compounds. Pectin at low concentration (0.05%) and iron stimulated
PL production. It was strongly repressed by galacturonic acid (1%), and negatively affected by nitrogen starvation, zinc and
temperatures above 45°C. PL yield was very weak below pH 4.0 and in anaerobic conditions. PG production was weakened by sucrose
and cation depletion. It was increased slightly by cysteine, ammonium nitrate and nitrogen starvation and significantly above
40°C. PG synthesis was not affected by acidic pH (3.0–6.0) or oxygen availability. As fermentation products, lactate and acetate
lowered the production of both enzymes while ethanol had no effect. The high proportion of pectinolytic producers among the
strains studied and analysis of factors influencing pectinolytic enzymes production, suggest that Bacillus sp. is liable to produce at least one enzyme during cocoa fermentation. 相似文献
24.
Zhen Zhang Junwen Li Jamshed Muhammad Juan Cai Fei Jia Yuzhen Shi Juwu Gong Haihong Shang Aiying Liu Tingting Chen Qun Ge Koffi Kibalou Palanga Quanwei Lu Xiaoying Deng Yunna Tan Wei Li Linyang Sun Wankui Gong Youlu Yuan 《PloS one》2015,10(8)
Cotton (Gossypium hirsutum L.) is an important agricultural crop that provides renewable natural fiber resources for the global textile industry. Technological developments in the textile industry and improvements in human living standards have increased the requirement for supplies and better quality cotton. Upland cotton 0–153 is an elite cultivar harboring strong fiber strength genes. To conduct quantitative trait locus (QTL) mapping for fiber quality in 0–153, we developed a population of 196 recombinant inbred lines (RILs) from a cross between 0–153 and sGK9708. The fiber quality traits in 11 environments were measured and a genetic linkage map of chromosome 25 comprising 210 loci was constructed using this RIL population, mainly using simple sequence repeat markers and single nucleotide polymorphism markers. QTLs were identified across diverse environments using the composite interval mapping method. A total of 37 QTLs for fiber quality traits were identified on chromosome 25, of which 17 were stably expressed in at least in two environments. A stable fiber strength QTL, qFS-chr25-4, which was detected in seven environments and was located in the marker interval between CRI-SNP120491 and BNL2572, could explain 6.53%–11.83% of the observed phenotypic variations. Meta-analysis also confirmed the above QTLs with previous reports. Application of these QTLs could contribute to improving fiber quality and provide information for marker-assisted selection. 相似文献
25.
Zana Adama Ouattara Jean Brice Boti Koffi Barthelemy Attioua Antoine Coffy Ahibo Joseph Casanova Félix Tomi Ange Bighelli 《化学与生物多样性》2013,10(11):2053-2060
The chemical composition of 48 leaf oil samples isolated from individual plants of Cleistopholis patens (Benth .) Engl. et Diels harvested in four Ivoirian forests was investigated by GC‐FID (determination of retention indices), GC/MS, and 13C‐NMR analyses. The main components identified were β‐pinene (traces–59.1%), sabinene (traces–54.2%), (E)‐β‐caryophyllene (0.3–39.3%), linalool (0.1–38.5%), (E)‐β‐ocimene (0.1–33.2%), germacrene D (0.0–33.1%), α‐pinene (0.1–32.3%), and germacrene B (0–21.2%). The 48 oil compositions were submitted to hierarchical clustering and principal components analyses, which allowed the distinction of three groups within the oil samples. The oil composition of the major group (Group I, 33 samples) was dominated by (E)‐β‐caryophyllene and linalool. The oils of Group II (eight samples) contained mainly β‐pinene and α‐pinene, while those of Group III (seven samples) were dominated by sabinene, limonene, and β‐phellandrene. Moreover, the compositions of the Ivoirian C. patens leaf oils differed from those of Nigerian and Cameroonian origins. 相似文献
26.
Yawovi Zikpi Amoudji Guillaume Guinot Lionel Hautier Koffi Evenyon Kassegne Nils Chabrol Anne-Lise Charruault Ampah Kodjo C. Johnson Raphaël Sarr Pauline Yawoa D. Da Costa Jeremy E. Martin 《Annales de Paléontologie》2021,107(2):102472
Following our fieldwork in Paleogene deposits of Togo, we herein report cranial as well as postcranial elements belonging to the family Dyrosauridae. This assemblage is dated to the Late Paleocene (Thanetian) from two quarries in southern Togo. The specimens include a partial skull presenting two large supratemporal fossae and a massive occipital condyle; long and slender isolated teeth; amphicoelous vertebrae including several articulated ones; and two osteoderms devoid of carina. The morphology of the partial skull reveals similarities with some African longirostrine forms such as Rhabdognathus spp., although this attribution cannot be confirmed. Longirostrine forms, known in the late Paleocene and early Eocene of the Iullemmeden basin (Nigeria, Niger, Mali, Algeria) and in the phosphates of Morocco and Tunisia, is only represented in Thanetian levels in Togo. Different palaeoenvironmental settings seem to have characterized the various African basins during the lower Eocene, with consequences for the geographic distribution of dyrosaurids. These dyrosaurid remains confirm the presence of the family in Togo during the Paleocene and underline the fossiliferous potential of the coastal sedimentary basin in Togo and in the bay of Benin. 相似文献
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This study investigated the diversity and dynamics of yeasts involved in alcoholic fermentation of a traditional sorghum beer from Côte d’Ivoire, tchapalo. A total of 240 yeast strains were isolated from fermenting sorghum wort inoculated with dry yeast from two geographic regions of Côte d’Ivoire (Abidjan and Bondoukou). Initial molecular identification to the species level was carried out using RFLP of PCR-amplified internal transcribed spacers of rDNA (ITS1-5.8S-ITS2). Ten different profiles were obtained from the restriction of PCR products with the three endonucleases HaeIII, CfoI and HinfI. Sequence analysis of the D1/D2 domain of the 26S rDNA and the ACT1 gene allowed us to assign these groups to six different species: Saccharomyces cerevisiae-like, Candida tropicalis, Pichia kudriavzevii, Pichia kluyveri, Kodamaea ohmeri and Meyerozyma caribbica. The most frequent species associated with tchapalo fermentation was S. cerevisiae-like (87.36%), followed by C. tropicalis (5.45%) and M. caribbica (2.71%). S. cerevisiae-like strains were diploid heterozygotes and exhibited three to four nucleotides divergence from the type strain in the D1/D2 domain and several indels in the more discriminant sequence of the intron of the ACT1 gene. During the process, the yeast species isolated and their frequencies varied according to the geographic origin of the dry yeast. The occurrence of some species was sporadic and only two non-Saccharomyces species were found in the final product. 相似文献
30.
Luc E. Coffeng Wilma A. Stolk Honorat G. M. Zouré J. Lennert Veerman Koffi B. Agblewonu Michele E. Murdoch Mounkaila Noma Grace Fobi Jan Hendrik Richardus Donald A. P. Bundy Dik Habbema Sake J. de Vlas Uche V. Amazigo 《PLoS neglected tropical diseases》2013,7(1)