Measurement of x-ray exposures using mailed thermoluminescent dosimeters.

Thermoluminescent dosimeters (TLD) have been sent by mail to all hospitals in Nova Scotia to survey the radiographic and fluoroscopic x-ray exposures to patients, For each radiographic system a TLD was placed in the x-ray field during a routine abdominal radiographic procedure on an average size patient (20 cm AP). The TLD was not visible on the film and in no way effected the examination. Fluoroscopic exposure rates were measured using TLD and a 20 cm water phantom.

Effect of small inhomogeneities on dose in a cobalt-60 beam.

The effect of small ring-shaped cavities on the dose delivered by a cobalt-60 beam to a homogeneous medium was studied experimentally and theoretically. Changes as small as 1 x 10(-4) of the total dose were measured. Experimental results show that, depending on the position of the cavity, replacing water with a small cavity can either increase or decrease scatter dose to a point in the medium.

Autoantibodies to a regulatory T cell subset in human ageing.

Anti-T cell autoantibodies were detected in some aged humans. Non-immunoglobulin-bearing (Ig-) cells were isolated from the peripheral blood of normal human donors by negative selection through Ficoll, using sheep erythrocytes coated with rabbit anti-human Ig. The Ig- cells were then reacted with sera from 83 individuals ranging in age from 60 to 99 years; 36% of the serum samples were noticeably reactive with the Ig- cells (average reactivity 28%).

Effects of functionally-distinct T-cell subsets on the maturation of null cells in man.

We have found that the 'null' cell population (negative for surface immunoglobulin and for E-rosette formation) includes cells which can develop surface immunoglobulin and secrete immunoglobulin in culture. The apparent 'maturation' of these null cells to immunoglobulin-secreting B cells was enhanced by T cells and may require T cells. T-cell subsets shown previously to have a helper effect on immunoglobulin secretion by peripheral blood B cells accelerated this maturation process, whereas subsets without helper effects on peripheral blood B cells did not.

Imbalance on the Weights Test and violence among delinquents.

This study forms part of a continuing series investigating the correlates of violent crime. The Weight Test, a measure of proprioceptive cognition, was administered to 41 community-retained Caucasian juvenile and adult male legal offenders whose offenses were rated for violence by the Violence Scale. As hypothesized, the Weight Test results were related to Violence Scale scores.

"Optimal" lateralization on the Tapping Test.

The present study was designed to test the general "imbalance" hypothesis in regard to the Tapping Test, a motor measure of finger-oscillation speed from the Halstead-Reitan neuropsychological battery. The study was prompted by a recent spate of reports linking cerebral lateralization to a variety of conditions. It was hypothesized that it would be possible to determine an "optimal," midrange of lateralization, to be identified by faster tapping speeds.

Parietal laterality and violence.

To test whether laterality of parietal lobe cerebral functioning might relate to a history of violent behavior, a sample of 33 male and female, right-handed juvenile offenders, divided into less and more violent, each performed the Weighs Test. A lateralization index (left-hand score divided by right-hand score) formed the dependent variable. Differences for sexes and ages, but not ethnicities, required corrections.

Are left-handers less violent?

Previous work has shown that left-handers are overrepresented among juvenile offenders. The present study was designed to test whether left-handers are also overrepresented among violent juvenile offenders. However, opposite to expectation, the results showed that left-handed offenders scored lower than right-handed offenders on the Violence Scale, a measure of the violence potential of offenses read from the legal record.

K+ influx components in ascites cells: the effects of agents interacting with the (Na+ + K+)-pump.

Several agents known to interact with the (Na+ + K+)-pump were tested for their effects on the components of steady-state K+ flux in ascites cells. 86Rb+ was used as a tracer for K+, and influx was differentiated into a ouabain-inhibitable "pump" component, a Cl--dependent and furosemide-sensitive "exchange" component, and a residual "leak" flux. All agents tested (ouabain, quercetin, oligomycin, phosphate) affected both the "pump" flux and the Cl--linked flux.

Delinquents and the Tapping Test.

This study provided Tapping Test norms for young legal offenders by measuring 54 Anglo male probationers (35 juveniles, 19 adults) in Study I, and 127 probationers aged 12-17 within eight sex/age/ethnicity subgroups in Study II. The Tapping Test, a measure of fine-motor speed, forms part of the Halstead-Reitan battery for neuropsychodiagnosis. Study I results suggest that tapping speed related to age for juvenile male delinquents, p less than .

Signal to noise enhancement in dark field electron micrographs of vasopressin: filtering of arrays of images in reciprocal space.

A technique for filtering arrays of images of dispersed molecules is presented which takes advantage of the crystallographic properties of regular arrays and the rapidity of optical treatment. A filter in reciprocal space consisting of perforations in a square or rectangular lattice, as determined by the image arrrangement, reduces noise and averages the images simultaneously by transmitting only regularly recurring image structure. The filter is universal for all image contents and introduces no additional biases.

Terminal ileitis, mesenteric lymphadenitis and appendicitis due to Yersinia pseudotuberculosis type VA: case report.

A case of terminal ileitis, mesenteric lymphadenitis and appendicitis is reported. Serological studies indicated infection with Yersinia pseudotuberculosis type VA. The patient's illness ran a chronic course necessitating resection of the terminal ileum.

Pulmonary skin embolism: a case report.

The incidental autopsy finding of an embolic fragment of skin partially occluding a pulmonary artery is described. It is suggested that the "graft" resulted from one of many needle punctures.