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181.
For allocation models consisting of n = 10, 6 and 4 equations, constrained generalized least squares coefficient estimates are compared with those obtained from the minimum information (MI) criterion in the sense of statistical information theory. The MI estimates are more efficient for n = 10. The bootstrap procedure is illustrated for the assessment of the variability of these estimates. 相似文献
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Danielle Promé Catherine Deon Jean-Claude Promé Henri Wajcman Frédéric Galacteros Yves Blouquit 《Journal of the American Society for Mass Spectrometry》1996,7(2):163-167
Hemoglobin Villeparisis was found during a systematic measurement of glycated hemoglobin. Electrospray mass spectra of the globin indicate an apparently unchanged molecular weight within the error range (0.01%). The tryptic digest of the β chain shows a chromatographically abnormal βT-9 peptide. The mass-to-charge ratio value of its [M+H]+ ion, as measured by liquid secondary ionization mass spectrometry, is one mass unit lower than that of the normal βT-9. However, the electrospray mass spectrum of this peptide exhibits mainly a doubly charged ion, whereas the normal βT-9 gives a triply charged ion. None of the allowed single amino acid substitutions for a 1-u shift down (Glu → Gln, Asp → Asn, or Asn → Ile) can explain the suppression of one protonation site. This can be due only to the replacement of the internal histidine by a nonbasic residue. Thus at least two amino acid exchanges occur within the same peptide: one involves the internal histidine, and the sum of the mass shifts is ?1 u. Consideration of the βT-9 sequence and taking account for the genetic code rules, the only possibility was 11His → Tyr (+26 mass shift) associated with 14Asn → Ser (?27 mass shift). This conclusion was consistent with the tandem mass spectrum of the [M+H]+ ion and was further confirmed by chemical microsequencing. 相似文献
184.
We give a polynomial time controlled version of a theorem of M. Hall: every real number can be written as the sum of two irrational numbers whose developments into a continued fraction contain only 1, 2, 3 or 4. Mathematics Subject Classification: 03D15, 03F60, 11A55, 68Q25. 相似文献
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An extraction method is described for the determination of traces of tin in which crystal violet is used as complexing agent. 相似文献
189.
P. Granet L. Mosca J. Saudraix J.C. Scheuer D. Vilanova H. Blumenfeld V.P. Henri J. Kesteman J. Laurent R. Windmolders E. de Wolf S. Tavernier F. Verbeure I.V. Ajinenko P.V. Chliapnikov L.N. Gerdyukov P.A. Gorbunov A.M. Rybin 《Nuclear Physics B》1978,140(3):389-408
The inclusive production of resonances is systematically studied in K+p interactions at 32 GeV/c. Total production cross sections are given for three baryon resonances, five vector and three 2+ tensor mesons. We also compare the central and fragmentation components of the total production cross sections with quark model predictions. 相似文献
190.