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71.
Effects of a low manganese diet on certain ovine characteristics 总被引:1,自引:0,他引:1
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73.
Kriss GA Shull JM Oegerle W Zheng W Davidsen AF Songaila A Tumlinson J Cowie LL Deharveng JM Friedman SD Giroux ML Green RF Hutchings JB Jenkins EB Kruk JW Moos HW Morton DC Sembach KR Tripp TM 《Science (New York, N.Y.)》2001,293(5532):1112-1116
The neutral hydrogen (H I) and ionized helium (He II) absorption in the spectra of quasars are unique probes of structure in the early universe. We present Far-Ultraviolet Spectroscopic Explorer observations of the line of sight to the quasar HE2347-4342 in the 1000 to 1187 angstrom band at a resolving power of 15,000. We resolve the He II Lyman alpha (Lyalpha) absorption as a discrete forest of absorption lines in the redshift range 2.3 to 2.7. About 50 percent of these features have H I counterparts with column densities N(H I) > 10(12.3) per square centimeter that account for most of the observed opacity in He II Lyalpha. The He II to H I column density ratio ranges from 1 to >1000, with an average of approximately 80. Ratios of <100 are consistent with photoionization of the absorbing gas by a hard ionizing spectrum resulting from the integrated light of quasars, but ratios of >100 in many locations indicate additional contributions from starburst galaxies or heavily filtered quasar radiation. The presence of He II Lyalpha absorbers with no H I counterparts indicates that structure is present even in low-density regions, consistent with theoretical predictions of structure formation through gravitational instability. 相似文献
74.
Morton O 《Science (New York, N.Y.)》2000,290(5495):1274a
Physicists at CERN, the European particle physics laboratory near Geneva, are making a last-ditch appeal to postpone demolition of the lab's Large Electron-Positron (LEP) collider. Scheduled to be scrapped in September to make room for a new device, the Large Hadron Collider, LEP was granted a 1-month stay of execution so physicists could continue experiments hinting at evidence for the Higgs boson--a theoretical particle that physicists have coveted for decades. On 8 November, CERN's director-general turned down a further extension, but the executive committee of the lab's staff association blasted the decision, saying that the case against LEP had not been made clearly enough. 相似文献
75.
Morton O 《Science (New York, N.Y.)》2000,289(5487):2014-2015
After 11 years of banging electrons and positrons together at higher energies than any other machine in the world, CERN, the European laboratory for particle physics, had decided to shut down the Large Electron-Positron collider (LEP) and install a new machine, the Large Hadron Collider (LHC), in its 27-kilometer tunnel. In 2005, the LHC will start bashing protons together at even higher energies. But tantalizing hints of a long-sought fundamental particle have forced CERN managers to grant LEP a month's reprieve. 相似文献
76.
Human liposarcomas: tissue cultures containing foci of transformed cells with viral particles 总被引:6,自引:0,他引:6
Viral particles occurring in foci of human liposarcoma cells in tissue culture are morphologically similar to the sarcoma viruses of the avian and murine species. Antibodies in the serum of the patient from whom the culture was originated reacted with cytoplasmic antigens in the original liposarcoma and in the cultured liposarcoma cells. 相似文献
77.
Cancer regression and autoimmunity in patients after clonal repopulation with antitumor lymphocytes 总被引:1,自引:0,他引:1
Dudley ME Wunderlich JR Robbins PF Yang JC Hwu P Schwartzentruber DJ Topalian SL Sherry R Restifo NP Hubicki AM Robinson MR Raffeld M Duray P Seipp CA Rogers-Freezer L Morton KE Mavroukakis SA White DE Rosenberg SA 《Science (New York, N.Y.)》2002,298(5594):850-854
We report here the adoptive transfer, to patients with metastatic melanoma, of highly selected tumor-reactive T cells directed against overexpressed self-derived differentiation antigens after a nonmyeloablative conditioning regimen. This approach resulted in the persistent clonal repopulation of T cells in those cancer patients, with the transferred cells proliferating in vivo, displaying functional activity, and trafficking to tumor sites. This led to regression of the patients' metastatic melanoma as well as to the onset of autoimmune melanocyte destruction. This approach presents new possibilities for the treatment of patients with cancer as well as patients with human immunodeficiency virus-related acquired immunodeficiency syndrome and other infectious diseases. 相似文献
78.
Forecasting fire season severity in South America using sea surface temperature anomalies 总被引:2,自引:0,他引:2
Chen Y Randerson JT Morton DC DeFries RS Collatz GJ Kasibhatla PS Giglio L Jin Y Marlier ME 《Science (New York, N.Y.)》2011,334(6057):787-791
Fires in South America cause forest degradation and contribute to carbon emissions associated with land use change. We investigated the relationship between year-to-year changes in fire activity in South America and sea surface temperatures. We found that the Oceanic Ni?o Index was correlated with interannual fire activity in the eastern Amazon, whereas the Atlantic Multidecadal Oscillation index was more closely linked with fires in the southern and southwestern Amazon. Combining these two climate indices, we developed an empirical model to forecast regional fire season severity with lead times of 3 to 5 months. Our approach may contribute to the development of an early warning system for anticipating the vulnerability of Amazon forests to fires, thus enabling more effective management with benefits for climate and air quality. 相似文献
79.
Mapping of the human Blym-1 transforming gene activated in Burkitt lymphomas to chromosome 1 总被引:7,自引:0,他引:7
C C Morton R Taub A Diamond M A Lane G M Cooper P Leder 《Science (New York, N.Y.)》1984,223(4632):173-175
Blym-1, a transforming gene detected by transfection of NIH 3T3 cells with DNA from Burkitt lymphomas, was mapped to the short arm of chromosome 1 (1p32) by chromosomal in situ hybridization. The Blym-1 gene was not physically linked to the cellular myc oncogene or to any of the immunoglobulin gene loci implicated in the characteristic chromosomal translocations in Burkitt lymphoma. 相似文献
80.