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Adgaba N Al-Ghamdi AA Chernet MH Ali YA Ansari MJ Radloff SE Howard RH 《Journal of economic entomology》2012,105(3):777-782
The orientation of combs in traditional beehives is extremely important for obtaining a marketable honey product. However, the factors that could determine comb orientation in traditional hives and the possibilities of inducing honey bees, Apis mellifera (L.), to construct more desirable combs have not been investigated. The goal of this experiment was to determine whether guide marks in traditional hives can induce bees to build combs of a desired orientation. Thirty-two traditional hives of uniform dimensions were used in the experiment. In 24 hives, ridges were formed on the inner surfaces of the hives with fermented mud to obtain different orientations, circular, horizontal, and spiral, with eight replicates of each treatment. In the remaining eight control hives, the inner surface was left smooth. Thirty-two well-established honey bee colonies from other traditional hives were transferred to the prepared hives. The colonies were randomly assigned to the four treatment groups. The manner of comb construction in the donor and experimental hives was recorded. The results showed that 22 (91.66%) of the 24 colonies in the treated groups built combs along the ridges provided, whereas only 2 (8.33%) did not. Comb orientation was strongly associated with the type of guide marks provided. Moreover, of the 18 colonies that randomly fell to patterns different from those of their previous nests, 17 (94.4%) followed the guide marks provided, irrespective of the comb orientation type in their previous nest. Thus, comb orientation appears to be governed by the inner surface pattern of the nest cavity. The results suggest that even in fixed-comb hives, honey bees can be guided to build combs with orientations suitable to honey harvesting, without affecting the colonies. 相似文献
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Florian Gehre Mebrat Ejo Kristina Fissette Pim de Rijk Cécile Uwizeye Elie Nduwamahoro Odin Goovaerts Dissou Affolabi Martin Gninafon Fanny M. Lingoupou Mamadou Dian Barry Oumou Sow Corinne Merle Piero Olliaro Fatoumata Ba Marie Sarr Alberto Piubello Juergen Noeske Martin Antonio Leen Rigouts Bouke C de Jong 《PloS one》2014,9(12)
In this study, we retrospectively analysed a total of 605 clinical isolates from six West or Central African countries (Benin, Cameroon, Central African Republic, Guinea-Conakry, Niger and Senegal). Besides spoligotyping to assign isolates to ancient and modern mycobacterial lineages, we conducted phenotypic drug-susceptibility-testing for each isolate for the four first-line drugs. We showed that phylogenetically modern Mycobacterium tuberculosis strains are more likely associated with drug resistance than ancient strains and predict that the currently ongoing replacement of the endemic ancient by a modern mycobacterial population in West/Central Africa might result in increased drug resistance in the sub-region. 相似文献
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Forty-five samples from 1988–1995 of naturally contaminated grain, barley, wheat and oats, three samples of mixed feed, and
16 samples of grain artificially inoculated with Fusarium culmorum during the flowering stage were analysed for deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-acetyl-DON), culmorin and hydroxy-culmorins.
These compounds are secondary metabolites produced by the fungal species F. culmorum and F. graminearum. Acetonitrile-water extract of the samples was purified on a MycosepTM#225 column, derivetized using pentafluoropropionic anhydride (PFPA) and analysed by gas chromatography-mass spectrometry
(GC-MS). The amount of each of culmorin, 5-, 12-, 14 and 15-hydroxy-culmorin and one unknown hydroxy-culmorin were determined
relative to the amount of DON plus 3-acetyl DON for each sample. The ratio between the total amount of culmorin compounds
and the DON compounds ranged from 0.14 to 1.07 in the samples. This study shows that there is a strong correlation between
the amount of DON present in the grain and the amount of culmorin and hydroxy-culmorins present. The ratio of each of the
culmorin compounds relative to the amount of DON compounds were in the same range in the grain artificially inoculated by
F. culmorum as found in an earlier study for F. culmorum strains cultivated on rice, while the hydroxy-culmorin profile in the naturally contaminated grain was more similar to what
was found for the F. graminearum cultures in the same study [1]. These results indicate that F. graminearum may be a relatively important source for DON in grain also in relatively cold areas.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
4.
Florian Gehre Samrat Kumar Lindsay Kendall Mebrat Ejo Oumie Secka Boatema Ofori-Anyinam Emmanuel Abatih Martin Antonio Dirk Berkvens Bouke C. de Jong 《PLoS neglected tropical diseases》2016,10(3)
BackgroundPhylogenetically distinct Mycobacterium tuberculosis lineages differ in their phenotypes and pathogenicity. Consequently, understanding mycobacterial population structures phylogeographically is essential for design, interpretation and generalizability of clinical trials. Comprehensive efforts are lacking to date to establish the West African mycobacterial population structure on a sub-continental scale, which has diagnostic implications and can inform the design of clinical TB trials.Conclusions/SignificanceBecause of the geographical divide of the mycobacterial populations in West Africa, individual research findings from one country cannot be generalized across the whole region. The unequal geographical family distribution should be considered in placement and design of future clinical trials in West Africa. 相似文献
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Langseth Wenche Ghebremeskel Mebrat Kosiak Barbara Kolsaker Per Miller David 《Mycopathologia》2001,152(1):23-34
Twenty-three Fusarium culmorum and 21 F. graminearumisolates were studied for their ability to produce mycotoxins and other secondary metabolites. The strains were cultivated
on rice, and the extracts analysed by gas chromatography mass spectrometry (GC-MS) after derivatization with pentafluoropropionic
(PFP) reagent. Two F. culmorum strains formed nivalenol and its acetylated derivatives (chemotype II), while all F. graminearum and the otherF. culmorum isolates produced deoxynivalenol (DON) via 3-acetyldeoxynivalenol (3-acetyl-DON) (chemotype IA). 15-hydroxy-culmorin, followed
by 5-hydroxy-culmorin were the main other metabolites produced F. culmorum, while 5-, 12- and an unidentified hydroxy-culmorin, suggested to be 14-hydroxy-culmorin, were the main metabolites of F. graminearum. The hydroxy-culmorin profile was found to be significantly different for the two Fusarium species. Minor amounts of about ten other hydroxy-culmorins, four hydroxy-culmorones and 3,13-dihydroxy-epiapotrichothecene
were also detected in most cultures. Traces of sambucinol seemed to be present in some of the isolates, but were not detected
in any significant amounts. The precursors in the biosynthetic sequence to 3-acetyldeoxynivalenol,7,8-dihydroxycalonectrin
and 15-deacetyl-7,8-dihydroxycalonectrin,were detected in most cultures. We also report the assignment of both the 1H and13C NMR data of 15-deacetyl-7,8-dihydroxycalonectrin, which has only been reported incorrectly before.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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