Radio Frequency Signals in Jupiter's Atmosphere     

LJ Lanzerotti  K Rinnert  G Dehmel  FO Gliem  EP Krider  MA Uman  J Bach 《Science (New York, N.Y.)》1996,272(5263):858-860

During the Galileo probe's descent through Jupiter's atmosphere, under the ionosphere, the lightning and radio emission detector measured radio frequency signals at levels significantly above the probe's electromagnetic noise. The signal strengths at 3 and 15 kilohertz were relatively large at the beginning of the descent, decreased with depth to a pressure level of about 5 bars, and then increased slowly until the end of the mission. The 15-kilohertz signals show arrival direction anisotropies. Measurements of radio frequency wave forms show that the probe passed through an atmospheric region that did not support lightning within at least 100 kilometers and more likely a few thousand kilometers of the descent trajectory. The apparent opacity of the jovian atmosphere increases sharply at pressures greater than about 4 bars.  相似文献   

Observation of Fermi pressure in a gas of trapped atoms     

Truscott AG  Strecker KE  McAlexander WI  Partridge GB  Hulet RG 《Science (New York, N.Y.)》2001,291(5513):2570-2572

We report the attainment of simultaneous quantum degeneracy in a mixed gas of bosons (lithium-7) and fermions (lithium-6). The Fermi gas has been cooled to a temperature of 0.25 times the Fermi temperature by thermal collisions with the evaporatively cooled bosons. At this temperature, the spatial size of the gas is strongly affected by the Fermi pressure resulting from the Pauli exclusion principle and gives clear experimental evidence for quantum degeneracy.  相似文献   

The seeds of cosmic structure     

Partridge RB 《Science (New York, N.Y.)》1992,257(5067):178-179

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A paradox for biology     

Partridge L 《Science (New York, N.Y.)》1991,252(5008):1000-1001

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Regulation of cytokine receptors by Golgi N-glycan processing and endocytosis     

Partridge EA  Le Roy C  Di Guglielmo GM  Pawling J  Cheung P  Granovsky M  Nabi IR  Wrana JL  Dennis JW 《Science (New York, N.Y.)》2004,306(5693):120-124

The Golgi enzyme beta1,6 N-acetylglucosaminyltransferase V (Mgat5) is up-regulated in carcinomas and promotes the substitution of N-glycan with poly N-acetyllactosamine, the preferred ligand for galectin-3 (Gal-3). Here, we report that expression of Mgat5 sensitized mouse cells to multiple cytokines. Gal-3 cross-linked Mgat5-modified N-glycans on epidermal growth factor and transforming growth factor-beta receptors at the cell surface and delayed their removal by constitutive endocytosis. Mgat5 expression in mammary carcinoma was rate limiting for cytokine signaling and consequently for epithelial-mesenchymal transition, cell motility, and tumor metastasis. Mgat5 also promoted cytokine-mediated leukocyte signaling, phagocytosis, and extravasation in vivo. Thus, conditional regulation of N-glycan processing drives synchronous modification of cytokine receptors, which balances their surface retention against loss via endocytosis.  相似文献   

A Burkholderia pseudomallei toxin inhibits helicase activity of translation factor eIF4A     

Cruz-Migoni A  Hautbergue GM  Artymiuk PJ  Baker PJ  Bokori-Brown M  Chang CT  Dickman MJ  Essex-Lopresti A  Harding SV  Mahadi NM  Marshall LE  Mobbs GW  Mohamed R  Nathan S  Ngugi SA  Ong C  Ooi WF  Partridge LJ  Phillips HL  Raih MF  Ruzheinikov S  Sarkar-Tyson M  Sedelnikova SE  Smither SJ  Tan P  Titball RW  Wilson SA  Rice DW 《Science (New York, N.Y.)》2011,334(6057):821-824

The structure of BPSL1549, a protein of unknown function from Burkholderia pseudomallei, reveals a similarity to Escherichia coli cytotoxic necrotizing factor 1. We found that BPSL1549 acted as a potent cytotoxin against eukaryotic cells and was lethal when administered to mice. Expression levels of bpsl1549 correlate with conditions expected to promote or suppress pathogenicity. BPSL1549 promotes deamidation of glutamine-339 of the translation initiation factor eIF4A, abolishing its helicase activity and inhibiting translation. We propose to name BPSL1549 Burkholderia lethal factor 1.  相似文献   

The laboratory culture of Dichelobacter nodosus in a footrot eradication program     

DR PITMAN  MA PALMER  LJ DEPIAZZI† 《Australian veterinary journal》1994,71(4):109-112

SUMMARY As part of a program to eradicate virulent footrot from Western Australia, 2745 isolates of Dichelobacter nodosus were isolated from 5263 specimens from 1883 submissions. The virulence of each isolate was assessed using protease thermostability and isoenzyme zymogram. We describe changes to the materials and methods required to handle these specimens and to reduce the interval between submission and report to 8 days.  相似文献   

Why Do Localities Provide Economic Development Incentives? Geographic Competition,Political Constituencies,and Government Capacity     

Michael R. Betz  Mark D. Partridge  David S. Kraybill  Linda Lobao 《Growth and change》2012,43(3):361-391

U.S. states and localities often engage in economic development policies using incentives and abatements for specific firms or industries. Yet, there is very little empirical evidence suggesting that such policies are successful. Why, then, do governments engage in these policies? In order to answer this question, we employ a model that considers not only geographic and economic factors, but also, in a novel application, local political conditions. A unique survey of U.S. county governments forms the basis for our empirical assessment of both traditional economic development policies and new‐wave policies. Using probit, Poisson, negative binomial, and spatial econometric models, we find evidence that the use of incentives is inversely related to local economic conditions. Furthermore, we find Republican counties are more apt to use incentives, though counties dominated by one political party are less likely to use them.  相似文献   

Detection of Aphanomyces invadans and epizootic ulcerative syndrome in the Murray‐Darling drainage     

J Go  I Marsh  M Gabor  V Saunders  RL Reece  J Frances  C Boys  LJ Gabor 《Australian veterinary journal》2012,90(12):513-514

Epizootic ulcerative syndrome was diagnosed, and the presence of Aphanomyces invadans confirmed, from an outbreak of clinical disease in wild‐caught bony bream (Nematalosa erebi) from the Darling River near Bourke, in New South Wales, Australia, during 2008. This confirms a significant extension of the agent beyond its historical range.  相似文献   

Extensive epidermal naevus in a foal     

MP Ruppin  MM Dennis  CL Smith  LJ Vogelnest 《Australian veterinary journal》2013,91(10):407-410

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