The Use of Granularity Measurements for Diagnosis of Fogging Effects

The granularity of black-and-white and of colour film exposed to X-rays and y-rays increases as the photon energy increases to ~0.1 MeV, remains fairly constant over the range ~0.1 to ~0.3 MeV and then decreases at higher energies. The granularity is significantly higher for exposure to X-rays in the range ~0.04 to ~ 1.2 MeV than for exposure to light. On the basis of these facts it is proposed that measurement of granularity may provide a reliable means of discriminating between these types of exposure. Confirmation is provided by examination of several samples of fogged film.     

The impact of cardiology on the collective effective dose in the North of England

Two cardiology X-ray rooms were monitored with dose-area product meters as part of a Regional Patient Dosimetry Programme. Dose-area product measurements on over 2000 patients undergoing examinations in the cardiology rooms are presented. The data have been corrected according to patient size where possible. In room A mean dose-area product values for coronary angiography, coronary angioplasty, radiofrequency ablation and mitral valvuloplasty were found to be 47.7, 72.2, 91.1 and 161.9 Gy cm2 respectively. In room B mean dose-area product values for coronary angiography and coronary angioplasty were found to be 23.4 and 51.6 Gy cm2 respectively. Observational studies were used to deduce the typical projections and technique factors. This typical examination was used to simulate an angiogram from which it was possible to derive factors to convert measured dose-area product values into estimates of effective dose. In room A, the effective doses were estimated to be 9.4, 14.2, 17.3 and 29.3 mSv for coronary angiography, coronary angioplasty, radiofrequency ablation and mitral valvuloplasty, respectively. The effective doses during coronary angiography and coronary angioplasty, performed in room B, were found to be 4.6 and 10.2 mSv, respectively. A regional survey of the frequency of these cardiac procedures was performed. It was deduced that the annual collective effective dose from these cardiac procedures in the North of England, the former Northern Region, was 45.7 manSv.     

Strategies for replacing animals in biomedical research

In 1959, Russell and Burch published their recommendations for applying the Three Rs (reduction, refinement and replacement alternatives) to the use of animals in scientific experimentation. At this time, they could not have predicted the effect of this fundamental concept on academic and industrial animal experimentation and in biomedical education. Although more than 30 years have passed, their ideas are gaining respectability and wide acceptance. This article reviews the recent advances in the use of non-animal methods in biomedical research, and discusses the outlook for the further implementation of 'alternatives'.     

Abstracts

Journal of the American Oil Chemists' Society -     

The area-calibration of mercury electrodes

Consideration is given to four alternativein situ methods of determining the area of a dropping mercury electrode. These methods are particularly relevant to those conditions where ordinary calibration procedures are not possible, for example, in closed systems at elevated pressures and temperatures.     

Assessment of Spirit Yield in Barley Breeding Lines

A number of random inbred lines of barley, grown at two sites, were assessed for high gravity spirit yield. A range of values was obtained and there was good agreement, for nearly all samples, between high gravity spirit yield and spirit yield predicted from extracts and fermentabilities measured by Institute of Brewing recommended methods. One sample, which gave a low predicted spirit yield but good high gravity spirit yield, was shown to have modified poorly and unevenly. Over both sites, high gravity spirit yield appeared to correlate negatively with grain nitrogen content, but this reflected large differences between sites in grain nitrogen. High gravity spirit yield did not correlate with soluble nitrogen, but did with fermentability, so samples with low levels of fermentability had either low or moderate levels of high gravity spirit yield. It was concluded that identification of genetic factors, influencing extract and fermentability, would enhance breeding of barley cultivars suitable for malt whisky distilling.