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Biomedical subjects

F C Lees

Publications and source records attributed to F C Lees.

5 recordsLinked to original sources
PubMed1978

Skin colorimetry in Belize. I. Conversion formulae.

Comparisons between skin colorimetry reports have been hampered by the common use of two different types of portable reflectometers, which sample reflectances at different wavelengths. In an attempt to provide direct comparability between the two machines, multiple linear regression equations were derived from reflectance spectrophotometry readings on 308 Black Caribs and 175 Creoles in Belize, Central America, using both machines. Cross validation tests show the coefficients presented are applicable to independent data sets and generally applicable to other heavily pigmented populations. Comparisons with previously published conversion formulae, which were from very small samples using simple linear regression, show a definite improvement in predictive accuracy when using multiple regression equations based on a large sample.

Belize↗
PubMed1978

Interobserver error in human skin colorimetry.

Twenty light-skinned adults were measured at the upper inner arm site using two commonly used reflectance spectrophotometers. Each subject was measured by each of three investigators to assess the influence of interobserver error on the reflectance readings. A repeated measures design analysis of variance showed no significant variance component due to observers.

Humans↗
PubMed1978

Admixture estimation using skin reflectance data.

Several different methods are suggested for the estimation of admixture proportions in hybrid populations based on skin reflectance data. These methods are applied to hybrid populations of known ancestry and yield results generally quite similar to those expected based on a simple genetic model. Results indicate the usefulness of these methods in hybridization studies and in the development and refinement of models of the genetics of skin color.

Africa↗