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41.
Microarray analysis shows that some microRNAs downregulate large numbers of target mRNAs 总被引:11,自引:0,他引:11
Lim LP Lau NC Garrett-Engele P Grimson A Schelter JM Castle J Bartel DP Linsley PS Johnson JM 《Nature》2005,433(7027):769-773
42.
Antigen-induced mitosis in liver macrophages of immunized mice 总被引:1,自引:0,他引:1
43.
M Liu HY Hwang H Tao AC Strikwerda K Fan GR Keiser AJ Sternbach KG West S Kittiwatanakul J Lu SA Wolf FG Omenetto X Zhang KA Nelson RD Averitt 《Nature》2012,487(7407):345-348
Electron-electron interactions can render an otherwise conducting material insulating, with the insulator-metal phase transition in correlated-electron materials being the canonical macroscopic manifestation of the competition between charge-carrier itinerancy and localization. The transition can arise from underlying microscopic interactions among the charge, lattice, orbital and spin degrees of freedom, the complexity of which leads to multiple phase-transition pathways. For example, in many transition metal oxides, the insulator-metal transition has been achieved with external stimuli, including temperature, light, electric field, mechanical strain or magnetic field. Vanadium dioxide is particularly intriguing because both the lattice and on-site Coulomb repulsion contribute to the insulator-to-metal transition at 340?K (ref. 8). Thus, although the precise microscopic origin of the phase transition remains elusive, vanadium dioxide serves as a testbed for correlated-electron phase-transition dynamics. Here we report the observation of an insulator-metal transition in vanadium dioxide induced by a terahertz electric field. This is achieved using metamaterial-enhanced picosecond, high-field terahertz pulses to reduce the Coulomb-induced potential barrier for carrier transport. A nonlinear metamaterial response is observed through the phase transition, demonstrating that high-field terahertz pulses provide alternative pathways to induce collective electronic and structural rearrangements. The metamaterial resonators play a dual role, providing sub-wavelength field enhancement that locally drives the nonlinear response, and global sensitivity to the local changes, thereby enabling macroscopic observation of the dynamics. This methodology provides a powerful platform to investigate low-energy dynamics in condensed matter and, further, demonstrates that integration of metamaterials with complex matter is a viable pathway to realize functional nonlinear electromagnetic composites. 相似文献
44.
ORGANIZATIONAL LEARNING AND VENDOR SUPPORT QUALITY BY THE USAGE OF APPLICATION SOFTWARE PACKAGES: A STUDY OF ASIAN ENTREPRENEURS 总被引:2,自引:0,他引:2
In this paper we study how organizational learning impacts organizational behavior, and howvendor support quality enhances product adoption and usage behavior.These constructs were verifiedusing Application Software Packages(ASP)-a prewritten, precoded, commercially available set ofprograms that eliminates the need for individuals or organizations to write their own softwareprograms for certain functions. The relationship between ASP usage, usage outcomes and useprocesses were also investigated. Two hundred and ninety-five Chinese, Indian, and Malayentrepreneurships were studied. It was found that usage outcome strongly determines usage, while useprocess has only an indirect relationship (via outcome) on usage. The impact of organizational learningand vendor service quality on usage, usage outcome, and use process were robust. Theoretical andpractical implications of the research are discussed. 相似文献
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Orton GS Yanamandra-Fisher PA Fisher BM Friedson AJ Parrish PD Nelson JF Bauermeister AS Fletcher L Gezari DY Varosi F Tokunaga AT Caldwell J Baines KH Hora JL Ressler ME Fujiyoshi T Fuse T Hagopian H Martin TZ Bergstralh JT Howett C Hoffmann WF Deutsch LK Van Cleve JE Noe E Adams JD Kassis M Tollestrup E 《Nature》2008,453(7192):196-199
Observations of oscillations of temperature and wind in planetary atmospheres provide a means of generalizing models for atmospheric dynamics in a diverse set of planets in the Solar System and elsewhere. An equatorial oscillation similar to one in the Earth's atmosphere has been discovered in Jupiter. Here we report the existence of similar oscillations in Saturn's atmosphere, from an analysis of over two decades of spatially resolved observations of its 7.8-microm methane and 12.2-microm ethane stratospheric emissions, where we compare zonal-mean stratospheric brightness temperatures at planetographic latitudes of 3.6 degrees and 15.5 degrees in both the northern and the southern hemispheres. These results support the interpretation of vertical and meridional variability of temperatures in Saturn's stratosphere as a manifestation of a wave phenomenon similar to that on the Earth and in Jupiter. The period of this oscillation is 14.8 +/- 1.2 terrestrial years, roughly half of Saturn's year, suggesting the influence of seasonal forcing, as is the case with the Earth's semi-annual oscillation. 相似文献
48.
Shotgun bisulphite sequencing of the Arabidopsis genome reveals DNA methylation patterning 总被引:10,自引:0,他引:10
Cokus SJ Feng S Zhang X Chen Z Merriman B Haudenschild CD Pradhan S Nelson SF Pellegrini M Jacobsen SE 《Nature》2008,452(7184):215-219
49.
On 17 Utah juniper ( Juniperus osteosperma [Torrey] L.) sites studied in Utah, Gymnosporangium inconspicuum was the most common rust fungus, followed in frequency and severity by G. nelsoni, G. kernianum, and G. speciosum . The incidence of G. kernianum was correlated with moderate temperatures and greater than average precipitation. True mistletoe, Phoradendron juniperinum Engelm., was present on seven sites. Incidence of foliage diseases of the mold-mildew type was low on sites with low spring and summer temperatures and high on sites with high summer and fall precipitation. Wood rot was common, and incidence seemed to be correlated with low winter temperatures and low soil nitrate but not with annual precipitation. Needle blight, shoot dieback, and needle cast symptoms were common and considered of abiotic origin. Their nonparasitic nature was indicated by lack of association with pathogenic organisms and the positive correlation of their incidence with winter injury and summer drought factors. Needle blight was also positively correlated with high soil salinity but negatively with high soil calcium regardless of salinity. A nonparametric model was developed that accurately predicted the frequency of the mold-mildew type diseases of J. osteosperma based on measured environmental site factors. 相似文献
50.
The fluctuating characteristics (numbers, biomass, condition, and young-adult ratios) of the Lahontan (Humboldt) cutthroat trout population in Chimney Creek, Nevada, are discussed in relationship to the unpredictable and unstable habitat in which the population occurs. One possible means of adapting to environmental capriciousness, staggered spawning, occurred during 1982, and clues as to the cause of this unusual event are sought by examining the runoff hydrographs of a nearby watershed for 1981 through 1984. The management values of the environmental tolerance of these native trout with respect to restoring viable trout fisheries in degraded Great Basin streams are also considered. 相似文献