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61.
Monochromatic images of Mercury at the sodium D(2) emission line showed excess sodium emission in localized regions at high northern and southern latitudes and day-to-day global variations in the distribution of sodium emission. These phenomena support the suggestion that magnetospheric effects could be the cause. Sputtering of surface minerals could produce sodium vapor in polar regions during magnetic substorms, when magnetospheric ions directly impact the surface. Another important process may be the transport of sodium ions along magnetic field lines toward polar regions, where they impact directly on the surface of Mercury and are neutralized to regenerate neutral sodium atoms. Day-to-day variations in planetary sodium distributions could result from changing solar activity, which can change the magnetosphere in time scales of a few hours. Observations of the sodium exosphere may provide a tool for remote monitoring of the magnetosphere of Mercury. 相似文献
62.
Cloned viral protein vaccine for foot-and-mouth disease: responses in cattle and swine 总被引:88,自引:0,他引:88
D G Kleid D Yansura B Small D Dowbenko D M Moore M J Grubman P D McKercher D O Morgan B H Robertson H L Bachrach 《Science (New York, N.Y.)》1981,214(4525):1125-1129
A DNA sequence coding for the immunogenic capsid protein VP3 of foot-and-mouth disease virus A12, prepared from the virion RNA, was ligated to a plasmid designed to express a chimeric protein from the Escherichia coli tryptophan promoter-operator system. When Escherichia coli transformed with this plasmid was grown in tryptophan-depleted media, approximately 17 percent of the total cellular protein was found to be an insoluble and stable chimeric protein. The purified chimeric protein competed equally on a molar basis with VP3 for specific antibodies to foot-and-mouth disease virus. When inoculated into six cattle and two swine, this protein elicited high levels of neutralizing antibody and protection against challenge with foot-and-mouth disease virus. 相似文献
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Abelson JF Kwan KY O'Roak BJ Baek DY Stillman AA Morgan TM Mathews CA Pauls DL Rasin MR Gunel M Davis NR Ercan-Sencicek AG Guez DH Spertus JA Leckman JF Dure LS Kurlan R Singer HS Gilbert DL Farhi A Louvi A Lifton RP Sestan N State MW 《Science (New York, N.Y.)》2005,310(5746):317-320
Tourette's syndrome (TS) is a genetically influenced developmental neuropsychiatric disorder characterized by chronic vocal and motor tics. We studied Slit and Trk-like 1 (SLITRK1) as a candidate gene on chromosome 13q31.1 because of its proximity to a de novo chromosomal inversion in a child with TS. Among 174 unrelated probands, we identified a frameshift mutation and two independent occurrences of the identical variant in the binding site for microRNA hsa-miR-189. These variants were absent from 3600 control chromosomes. SLITRK1 mRNA and hsa-miR-189 showed an overlapping expression pattern in brain regions previously implicated in TS. Wild-type SLITRK1, but not the frameshift mutant, enhanced dendritic growth in primary neuronal cultures. Collectively, these findings support the association of rare SLITRK1 sequence variants with TS. 相似文献
65.
Hafezparast M Klocke R Ruhrberg C Marquardt A Ahmad-Annuar A Bowen S Lalli G Witherden AS Hummerich H Nicholson S Morgan PJ Oozageer R Priestley JV Averill S King VR Ball S Peters J Toda T Yamamoto A Hiraoka Y Augustin M Korthaus D Wattler S Wabnitz P Dickneite C Lampel S Boehme F Peraus G Popp A Rudelius M Schlegel J Fuchs H Hrabe de Angelis M Schiavo G Shima DT Russ AP Stumm G Martin JE Fisher EM 《Science (New York, N.Y.)》2003,300(5620):808-812
Degenerative disorders of motor neurons include a range of progressive fatal diseases such as amyotrophic lateral sclerosis (ALS), spinal-bulbar muscular atrophy (SBMA), and spinal muscular atrophy (SMA). Although the causative genetic alterations are known for some cases, the molecular basis of many SMA and SBMA-like syndromes and most ALS cases is unknown. Here we show that missense point mutations in the cytoplasmic dynein heavy chain result in progressive motor neuron degeneration in heterozygous mice, and in homozygotes this is accompanied by the formation of Lewy-like inclusion bodies, thus resembling key features of human pathology. These mutations exclusively perturb neuron-specific functions of dynein. 相似文献
66.
Morgan TH 《Science (New York, N.Y.)》1908,28(713):287-288
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Morgan TH 《Science (New York, N.Y.)》1911,34(880):636-638
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Curran MA van Ommen TD Morgan VI Phillips KL Palmer AS 《Science (New York, N.Y.)》2003,302(5648):1203-1206
The instrumental record of Antarctic sea ice in recent decades does not reveal a clear signature of warming despite observational evidence from coastal Antarctica. Here we report a significant correlation (P < 0.002) between methanesulphonic acid (MSA) concentrations from a Law Dome ice core and 22 years of satellite-derived sea ice extent (SIE) for the 80 degrees E to 140 degrees E sector. Applying this instrumental calibration to longer term MSA data (1841 to 1995 A.D.) suggests that there has been a 20% decline in SIE since about 1950. The decline is not uniform, showing large cyclical variations, with periods of about 11 years, that confuse trend detection over the relatively short satellite era. 相似文献
70.