NURSING ASSISTANTS AS CO-THERAPISTS

Summary The present study was conducted in a small 20-bed hospital for severely subnormal children. Ten children who had evidenced a history of problem behaviour were the subjects of behaviour modification programmes aimed at reducing the frequency of problem behaviour. The main aim of the study was to establish if nursing assistants can become effective co-therapists. Two questions were investigated: (1) Can nursing assistants after 12 months' training have a sound knowledge of the principles of behaviour modification and (2) Can these nursing assistants effectively employ behaviour modification techniques which result in reductions of problem behaviour episodes? It is argued that although nursing assistants may have had an inadequate and erroneous knowledge of the principles of behaviour modification, they were able to employ behavioural techniques which affected reductions in the problem behaviours recorded. Clinical difficulties related to applied research of this kind are raised in discussion.     

Task Complexity and Visual Acuity in Senile Macular Degeneration

ABSTRACT The effects of choice of test object and inter-symbol spacing (contour interaction) on the measurement of low visual acuities was investigated. Visual acuities of sixteen subjects with senile macular degeneration and five age-matched normal subjects were measured using different test targets of varying complexities. Visual acuity of both groups of subjects decreased with increasing task complexity but the trend was more marked for the low vision subjects. However, within the low vision group, the complexity effect was not dependent on the level of visual acuity. This study showed that visual acuity of persons with senile macular degeneration can be measured equally well with single letters, constant contour interaction Landolt rings, or the Bailey-Lovie letter chart but the test used should be specified. Grating targets and word charts measure different visual functions from standard visual acuity tests.     

On estimating the frequency of a recessive gene in a random mating population

The maximum likelihood estimator of the frequency of a recessive gene in a random mating population is simply the square root of the proportion of recessive individuals in a random sample. However, its asymptotic variance, i.e. the inverse of Fisher's information, has an unexpected functional form, and its use may lead to incorrect inferences. An explanation for this is sought by deriving an expansion for the exact variance of the estimator. Further, a number of calculations reveal conditions under which the asymptotic variance provides a reasonable approximation to the exact variance. Lastly, the problem of setting confidence limits to the gene frequency is discussed, with a number of approximations being considered.     

Iopamidol and meglumine diatrizoate: comparison of effects on patient discomfort during aortofemoral arteriography

Iopamidol was compared with Renografin-60 (meglumine diatrizoate, Squibb) in a controlled, randomized double-blind study of 40 patients undergoing peripheral arteriography for arteriosclerotic occlusive disease to determine which agent caused less discomfort. Each patient was evaluated for objective signs of discomfort and subjective feelings of pain and heat. Monitoring was achieved by multiple physical examinations, chemical tests, electrocardiograms, and intra-arterial pressure recordings. It is concluded that iopamidol is safe and causes significantly less patient discomfort than Renografin-60.