Public papers of David B. Hill : governor /

[v.1] 1885 -- [v.2] 1886 -- [v.3] 1887 -- [v.4] 1888 -- [v.5] 1889 -- [v.6] 1890 -- [v.7] 1891.

Public health and clinical dilemmas resulting from imprecise vitamin D tests

Objective: To determine whether there are clinical and public health dilemmas resulting from the reproducibility of routine vitamin D assays. Methods: Blinded agreement studies were conducted in eight clinical laboratories using two commonly used assays to measure serum 25-hydroxyvitamin D (25(OH)D) levels in Australasia and Canada (DiaSorin Radioimmunoassay (RIA) and DiaSorin LIAISON® one). Results: Only one laboratory measured 25(OH)D with excellent precision. Replicate 25(OH)D measurements varied by up to 97% and 15% of paired results differed by more than 50%. Thirteen percent of subjects received one result indicating insufficiency [25-50 nmol/l] and another suggesting adequacy [>50 nmol/l]). Agreement ranged from poor to excellent for laboratories using the manual RIA, while the precision of the semi-automated Liaison® system was consistently poor. Conclusions: Recent interest in the relevance of vitamin D to human health has increased demand for 25(OH)D testing and associated costs. Our results suggest clinicians and public health authorities are making decisions about treatment or changes to public health policy based on imprecise data. Clinicians, researchers and policy makers should be made aware of the imprecision of current 25(OH)D testing so that they exercise caution when using these assays for clinical practice, and when interpreting the findings of epidemiological studies based on vitamin D levels measured using these assays. Development of a rapid, reproducible, accurate and robust assay should be a priority due to interest in populationbased screening programs and research to inform public health policy about the amount of sun exposure required for human health. In the interim, 25(OH)D results should routinely include a statement of measurement uncertainty.

The interaction of flexural-gravity waves with periodic geometries

A periodic structure of finite extent is embedded within an otherwise uniform two-dimensional system consisting of finite-depth fluid covered by a thin elastic plate. An incident harmonic flexural-gravity wave is scattered by the structure. By using an approximation to the corresponding linearised boundary value problem that is based on a slowly varying structure in conjunction with a transfer matrix formulation, a method is developed that generates the whole solution from that for just one cycle of the structure, providing both computational savings and insight into the scattering process. Numerical results show that variations in the plate produce strong resonances about the ‘Bragg frequencies’ for relatively few periods. We find that certain geometrical variations in the plate generate these resonances above the Bragg value, whereas other geometries produce the resonance below the Bragg value. The familiar resonances due to periodic bed undulations tend to be damped by the plate.

Wave scattering by an axisymmetric ice floe of varying thickness

The problem of water wave scattering by a circular ice floe, floating in fluid of finite depth, is formulated and solved numerically. Unlike previous investigations of such situations, here we allow the thickness of the floe (and the fluid depth) to vary axisymmetrically and also incorporate a realistic non-zero draught. A numerical approximation to the solution of this problem is obtained to an arbitrary degree of accuracy by combining a Rayleigh–Ritz approximation of the vertical motion with an appropriate variational principle. This numerical solution procedure builds upon the work of Bennets et al. (2007, J. Fluid Mech., 579, 413–443). As part of the numerical formulation, we utilize a Fourier cosine expansion of the azimuthal motion, resulting in a system of ordinary differential equations to solve in the radial coordinate for each azimuthal mode. The displayed results concentrate on the response of the floe rather than the scattered wave field and show that the effects of introducing the new features of varying floe thickness and a realistic draught are significant.

Results of meridian observations of stars made at the Royal Observatory, Cape of Good Hope, from ...

Imprint varies.

Results of meridian observations made at the Royal Observatory, Cape of Good Hope, during the years ...

Mode of access: Internet.

Letters from the East and from the West.

"The 'Letters from the East, or the valley of the Connecticut river,' were first published in the National intelligencer."--Pref. note.

A sermon, delivered January 1, 1822, at the ordination of the Rev. Joseph Bennet [i.e. Bennett], to the pastoral care of the Congregational Church and Society in Woburn, Mass. ...

Pages [33]-39 contain: The charge to the people, by the Rev. Jacob Coggin, of Tewksbury. Coggin's charge to the people was also issued separately.

A trip from Boston to Littleton, through the notch of the White Mountains.

First pub. in the "Baltimore patriot."

Éloge de Abraham Furtado, l'un des adjoints de la mairie de Bordeaux, [etc.], décédé le 29 janvier 1817.

Mode of access: Internet.

An oration, on the importance of cultivating the sciences, delivered at Dartmouth college, before the New Hampshire alpha of the Phi Beta Kappa, August 21, 1828.

Mode of access: Internet.

Six months in Ascension; an unscientific account of a scientific expedition.

Introduction signed: David Gill.

Incidents and anecdotes of the Civil War.

Mode of access: Internet.