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Skirvin DJ Kravar-Garde L Reynolds K Jones J Mead A Fenlon J 《Bulletin of entomological research》2007,97(3):309-315
Two experiments were done to examine the predation of thrips, and the movement of Orius laevigatus Fieber and Neoseiulus cucumeris (Oudemans) in the presence and absence of two supplemental food sources, pollen and the fungus Trichoderma viride. The presence of pollen led to a 55% reduction in predation of the thrips by N. cucumeris and a 40% reduction in thrips predation by O. laevigatus, in experiments using single predators. The presence of fungus had no significant effect on thrips predation by either of the natural enemy species. Movement of the natural enemies was examined in a multiple predator experiment, and this showed that O. laevigatus was more likely to remain on the plant in the presence of thrips and when supplemental food, either pollen or fungus, was present. For N. cucumeris, there was no association between the presence of thrips and the mite, with the majority of the mites being found on the leaves where pollen was present. Although the single and multiple predator experiments were done at different times, the indications are that the predation rates of the N. cucumeris do not differ greatly between the two experiments, suggesting that there may be a potential interference effect between the mites, which is not present for O. laevigatus. The significance of these results for the use of supplemental food sources in biological control is discussed. 相似文献
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Leaf retention is important in transferring energy from riparian trees to stream food webs. Retention increases with geomorphic
complexity such as substrate coarseness, sinuosity, and the presence of debris dams. High discharge can reduce retention,
particularly when streams lack physical trapping features. Travertine formations, caused by calcium carbonate deposition,
can alter stream morphology. To date, however, we know of no study testing the effect of travertine on leaf retention. This
study capitalized on a river restoration project in Fossil Creek, Arizona, where water was returned to the channel after a
century of diversion. We examined how the fixed factors Flow (before and after restoration) and Morphology (travertine and
riffle-pool sites) affected leaf retention. Leaf retention was higher in sites where travertine forms barriers across the
river, relative to sites with riffle-pool morphology. Most leaves retained in travertine reaches were concentrated at the
bottom of pools formed between dams. Although flow restoration did not alter retention rates across all sites, it diminished
them at travertine sites, indicating an interaction between stream flow and morphology. We conclude that stream complexity
and leaf retention are enhanced by travertine deposition but that high discharge can reduce the retentive capacity of in-stream
structures.
Handling editor: Darren Ryder 相似文献
58.
Michael J. Arrowood Jan R. Mead Long-ti Xie Xiangdong You 《FEMS microbiology letters》1996,136(3):245-249
Abstract Despite the evaluation of over 100 antimicrobial drugs, the diarrheal disease cryptosporidiosis has remained refractory to treatment. We report the evaluation of five dinitroaniline herbicides including trifluralin, profluralin, nitralin, pendimethalin, and fluchloralin for anticryptosporidial activity in an in vitro cultivation model of Cryptosporidium parvum . All five compounds exhibited significant anticryptosporidial activities with no corresponding evidence of toxicity. The most active compound was pendimethalin with an IC50 of 0.19 μM while nitralin was the least active with an IC50 of 4.5 μM. These compounds should be evaluated further in an animal model of cryptosporidiosis. 相似文献
59.
Vinay Dhodda Ronald Godiska Jeffrey D. VanWye David Mead Rebecca Hochstein Lynne Sheets Sarah Vande Zande Chris Niebauer Douglas L. Crawford Marjorie F. Oleksiak 《PloS one》2010,5(9)
Background
ExCyto PCR cells provide a novel and cost effective means to amplify DNA transformed into competent bacterial cells. ExCyto PCR uses host E. coli with a chromosomally integrated gene encoding a thermostable DNA polymerase to accomplish robust, hot-start PCR amplification of cloned sequences without addition of exogenous enzyme.Results
Because the thermostable DNA polymerase is stably integrated into the bacterial chromosome, ExCyto cells can be transformed with a single plasmid or complex library, and then the expressed thermostable DNA polymerase can be used for PCR amplification. We demonstrate that ExCyto cells can be used to amplify DNA from different templates, plasmids with different copy numbers, and master mixes left on ice for up to two hours. Further, PCR amplification with ExCyto cells is comparable to amplification using commercial DNA polymerases. The ability to transform a bacterial strain and use the endogenously expressed protein for PCR has not previously been demonstrated.Conclusions
ExCyto PCR reduces pipetting and greatly increases throughput for screening EST, genomic, BAC, cDNA, or SNP libraries. This technique is also more economical than traditional PCR and thus broadly useful to scientists who utilize analysis of cloned DNAs in their research. 相似文献60.
Jere Mead 《Journal of applied physiology》2007,102(4):1708-9; discussion 1710