Dempster

M.A. Dempster, B.F. MacDonald, P.J. Gemperline and N.R. Boyer, A near-infrared reflectance analysis method for the non invasive identification of film-coated and non-film-coated, blister-packed tablets. Anal. Chim. Acta, 310 (1995) 43-51. 

Principles and Characteristics The original idea of spark-source mass spectrometry (SSMS) is due to Dempster [356], long before the first commercial instruments. In spark-source MS, atomisation and ionisation... 

Spargo, J.W. "The Canon s Yeomans prologue and tale." In Sources and analogues of Chaucer s Canterbury Tales, eds. W.F. Bryan and G. Dempster, 658-698. New York London Humanities P Routledge Kegan Paul, 1958. 

Deveaux P, Kibel MA, Dempster WS, et al. 1986. Blood lead levels in preschool children in Cape Town. S Afr Med J 29 421-424. 

Franck and Hertz (1913) first demonstrated that an electron has to acquire a minimum energy before it can ionize. Thus, they provided an operational definition of the ionization potential and showed that it is an atomic or molecular property quite free from experimental artifacts. However, this kind of experiment does not tell anything about the nature of the positive ion for this, one needs a mass spectrometric analysis. Although Thompson had demonstrated the existence of H+, H2+, and H3+ in hydrogen discharge, it seems that Dempster (1916) was the first to make a systematic study of the positive ions. 

MS is based on the production of gas phase ions and on their separation according to their mass-to-charge (m/z) ratios. It was introduced at the end of the nineteenth century and for a long time it was confined to the physical sciences, being used to study elementary particles of matter. Pioneering works by J. J. Thomson, F. W. Aston and A. J. Dempster provided the basis for the determination of the isotopes of elements. In the 1940s, MS... 

Migaud, M., Charlesworth, P., Dempster, M. et al. Enhanced long-term potentiation and impaired learning in mice with mutant postsynaptic density-95 protein. Nature 396 433-439, 1998. 

Electron ionization (El) was introduced in 1921 by Dempster, who used it to measure lithium and magnesium isotopes [31]. Modern El sources are, however, based on the design by Bleakney [32] and Nier [33, 34], who both worked in Prof. J. T. Tate s laboratory. In El ions are produced by directing an electron beam into a low pressure vapor of analyte molecules. 

Although methods are available for including historical control data in the formal statistical analysis (Tarone, 1982 Dempster et al., 1983 Haseman, 1990), this is usually not done and for good reason. The heterogeneity of historical data requires that they be used qualitatively and selectively to aid in the final interpretation of the data, after completion of the formal statistical analysis. Table 9.3 presents a summary of background tumor incidences for the most commonly employed rodent strains. 

Dempster, A.P., Selivyn, M.R. and Weeks, B.J. (1983). Combining historical and randomized controls for assessing trends in proportions. J. Amer. Stat. Assoc. 78 221-227. 

Slater GF, Dempster HS, Lollar BS, Ahad J (1999) Environ Sci Technol 33 190... 

Slater GF, Dempster HD, Lollar SB, Spivack J, Brennan M, Mackenzie P (1998) Proceedings of the 1st International Battelle Conference on Remediation of Chlorinated and Recalcitrant Compounds, Monterey, CA... 

Dempster HS, Sherwood Lollar B, Feenstra S (1997) Environ Sci Technol 31 3193... 

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