Robert A. Donahue

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This paper discusses the use of web metrics tools at four digital libraries, the Instructional Architect, the Library of Congress, the National Science Digital Library, and WGBH Teachers' Domain. We describe some of the issues involved in using web metrics to report on ongoing web site performance. We also describe how web metrics can be used for focused(More)
Radial velocity variations have revealed planets orbiting 51 Peg, 47 UMa, and 70 Vir, and a low-mass companion orbiting HD 114762. We analyze parallel records of photometric measurements in StroŽ mgren b and y and Johnson V , R, and I passbands and Ca II H and K Ñuxes in those stars. In the case of 51 Peg, the high precision of the di†erential photometric(More)
Radial velocity variations have revealed planets orbiting 51 Peg, 47 UMa, and 70 Vir, and a low-mass companion orbiting HD 114762. We analyze parallel records of photometric measurements and Ca II H and K uxes in those stars. In the case of 51 Peg, the high precision of the diierential photometric measurements made by the 0.75m Automatic Photoelectric(More)
Disk-integrated solar chromospheric Ca II K-line (3933.68 A) uxes have been measured almost daily at Sacramento Peak Observatory since 1977. Using observing windows selected to mimic seasonal windows for chromospheric measurements of lower main-sequence stars such as those observed by Mount Wilson Observatory's HK Project, we have measured the solar(More)
OBJECTIVE To assess sex and ethnic differences in hyperinsulinemia/insulin resistance and to examine the impact of percent body fat on such differences. RESEARCH DESIGN AND METHODS A cross-sectional epidemiological study was performed in a normoglycemic population of African-Americans (n = 159), Cuban Americans (n = 128), and non-Hispanic whites (n = 207)(More)
An association between blood pressure and insulin sensitivity among normotensive African-Americans has not been demonstrated consistently in epidemiologic studies. Part of the discrepancy may be due to studying persons with profound obesity-an insulin-resistant state itself. The association between insulin-mediated glucose uptake (i.e., insulin sensitivity)(More)
The extracellular hemoglobin of the earthworm has four major O2-binding chains, a, b, c and d, together with additional non-heme structural chains that are required for assembly. Although the abc trimer self-associates extensively at least to (abc)10, addition of chain d results in the formation of a discrete 280 kDa complex corresponding to (abcd)4. Thus a(More)
Chromospheric Ca II H and K uxes have been measured in a sample of 100 stars on or near the lower main sequence at Mount Wilson Observatory. Observations were made several times a week and span more than ten years. Within an observing season, many stars show periodic variations due to rotation. Thirty-six of the stars have highly-signiicant periods in at(More)