Biomedical subjects

R Pinkham

Publications and source records attributed to R Pinkham.

3 recordsLinked to original sources

PubMed1991

A space-variant differential operator for visual sensitivity.

All the elements of a Fourier analysis can be derived from the experiments of Graham and Robson on contrast sensitivity. Once their experiment is posed as an eigenvalue problem, a complete orthonormal set of eigenfunctions results from solving the associated differential equation. Neither sine and cosine nor Gabor functions result. Instead, the Hermite functions arise as the eigenfunctions of a space-variant differential operator used to model the contrast sensitivity of human observers. These functions, up to a constant, are their own Fourier transforms, and in principle can be used to exactly represent the Fourier transform of naturally occurring visual images.

Contrast Sensitivity↗

PubMed1978

Preliminary results of combined surgery and adjuvant Bacillus Calmette-Guérin plus levamisole treatment of resectable lung cancer.

The administration of intrapleural bacillus Calmette-Guérin (BCG) alone and intrapleural BCG plus levamisole was compared to placebo in patients with resectable, non-small cell cancer of the lung. This report is based on an interim analysis of 100 eligible patients with a median followup of 245 days. No significant treatment effects are apparent at the present time, although current trends are consistent with an approximate 30% reduction in recurrence rate in patients receiving intrapleural BCG. There is little evidence to suggest that the addition of levamisole will contribute to this effect. A relationship between purified protein derivative conversion and tumor recurrence is apparent. Failure to manifest purified protein derivative conversion following administration of intrapleural BCG is associated with a significantly greater risk of tumor recurrence.

Adenocarcinoma↗

PubMed1977

Testing the significance of risk estimates for the predisposition of heterozygotes to common diseases.

A maximum-likelihood method has been used previously to estimate, from family studies, the relative risk of common disorders for heterozygous carriers of genes for certain autosomal recessive syndromes. In this paper statistical significance of relative risk estimates was evaluated using critical values from computer-generated sampling distributions of the test statistic. In several practical cases a significance test based on the computer-generated distribution was more conservative than a test which assumed normality for the sampling distribution.

Genes, Recessive↗