排序方式: 共有9条查询结果,搜索用时 36 毫秒
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DNA sequence of both chromosomes of the cholera pathogen Vibrio cholerae 总被引:23,自引:0,他引:23
Heidelberg JF Eisen JA Nelson WC Clayton RA Gwinn ML Dodson RJ Haft DH Hickey EK Peterson JD Umayam L Gill SR Nelson KE Read TD Tettelin H Richardson D Ermolaeva MD Vamathevan J Bass S Qin H Dragoi I Sellers P McDonald L Utterback T Fleishmann RD Nierman WC White O Salzberg SL Smith HO Colwell RR Mekalanos JJ Venter JC Fraser CM 《Nature》2000,406(6795):477-483
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Nine species of mites of the genus Proctolaelaps were collected in flowers or phoretic in the nares of hummingbirds in Trinidad. Previously named species P. kirmsei , P. glaucis , and P. belemensis are redescribed, and six new species are described: P. jurgatus , P. mermillion , P. rabulatus , P. contumex , P. certator , and P. contentiosus . Proctolaelaps belemensis cyanocompsae is raised to specific status. Host plants are given for all species except P. mermillion , which was collected only from a hummingbird host. New World flower-inhabiting Proctolaelaps are grouped into two hypothetically monophyletic lineages, the kirmsei -group and the belemensis -group, on the basis of adult morphology. A key to the nine Trinidadian species is given. 相似文献
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Pryor WR Rymer AM Mitchell DG Hill TW Young DT Saur J Jones GH Jacobsen S Cowley SW Mauk BH Coates AJ Gustin J Grodent D Gérard JC Lamy L Nichols JD Krimigis SM Esposito LW Dougherty MK Jouchoux AJ Stewart AI McClintock WE Holsclaw GM Ajello JM Colwell JE Hendrix AR Crary FJ Clarke JT Zhou X 《Nature》2011,472(7343):331-333
Although there are substantial differences between the magnetospheres of Jupiter and Saturn, it has been suggested that cryovolcanic activity at Enceladus could lead to electrodynamic coupling between Enceladus and Saturn like that which links Jupiter with Io, Europa and Ganymede. Powerful field-aligned electron beams associated with the Io-Jupiter coupling, for example, create an auroral footprint in Jupiter's ionosphere. Auroral ultraviolet emission associated with Enceladus-Saturn coupling is anticipated to be just a few tenths of a kilorayleigh (ref. 12), about an order of magnitude dimmer than Io's footprint and below the observable threshold, consistent with its non-detection. Here we report the detection of magnetic-field-aligned ion and electron beams (offset several moon radii downstream from Enceladus) with sufficient power to stimulate detectable aurora, and the subsequent discovery of Enceladus-associated aurora in a few per cent of the scans of the moon's footprint. The footprint varies in emission magnitude more than can plausibly be explained by changes in magnetospheric parameters--and as such is probably indicative of variable plume activity. 相似文献
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Global spread of microorganisms by ships 总被引:47,自引:0,他引:47
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Wang J Soisson SM Young K Shoop W Kodali S Galgoci A Painter R Parthasarathy G Tang YS Cummings R Ha S Dorso K Motyl M Jayasuriya H Ondeyka J Herath K Zhang C Hernandez L Allocco J Basilio A Tormo JR Genilloud O Vicente F Pelaez F Colwell L Lee SH Michael B Felcetto T Gill C Silver LL Hermes JD Bartizal K Barrett J Schmatz D Becker JW Cully D Singh SB 《Nature》2006,441(7091):358-361
Bacterial infection remains a serious threat to human lives because of emerging resistance to existing antibiotics. Although the scientific community has avidly pursued the discovery of new antibiotics that interact with new targets, these efforts have met with limited success since the early 1960s. Here we report the discovery of platensimycin, a previously unknown class of antibiotics produced by Streptomyces platensis. Platensimycin demonstrates strong, broad-spectrum Gram-positive antibacterial activity by selectively inhibiting cellular lipid biosynthesis. We show that this anti-bacterial effect is exerted through the selective targeting of beta-ketoacyl-(acyl-carrier-protein (ACP)) synthase I/II (FabF/B) in the synthetic pathway of fatty acids. Direct binding assays show that platensimycin interacts specifically with the acyl-enzyme intermediate of the target protein, and X-ray crystallographic studies reveal that a specific conformational change that occurs on acylation must take place before the inhibitor can bind. Treatment with platensimycin eradicates Staphylococcus aureus infection in mice. Because of its unique mode of action, platensimycin shows no cross-resistance to other key antibiotic-resistant strains tested, including methicillin-resistant S. aureus, vancomycin-intermediate S. aureus and vancomycin-resistant enterococci. Platensimycin is the most potent inhibitor reported for the FabF/B condensing enzymes, and is the only inhibitor of these targets that shows broad-spectrum activity, in vivo efficacy and no observed toxicity. 相似文献
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