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The research consisted of a comparative analysis of the written language of a working-class group of subjects and a middle-class group, the aim being to test Bernstein's socio-linguistic theory of a class-based limitation to a restricted ' code. Both groups of subjects were given essay titles demanding different forms of stylistic treatment. The written language they produced was then analysed to assess and compare the degree of stylistic variation it contained. On certain linguistic items stylistic 'shifts ' were predicted in the writing of both groups as they moved from title to title. In certain areas and contrary to the preconceptions of earlier workers in the field it was predicted that these stylistic shifts would be more pronounced in the writing of working-class subjects. In line with the prediction, the working-class group was shown to posses a greater stylistic variation in its writing on the titles and linguistic indicators selected. Their scores on the items were more likely to move in the predicted direction and, when they did so, were more likely than those of the middle-class group to move consistently and to a level of statistical significance.

Models of the spatial response of human vision are important for applied work, but the available contrast sensitivity function (CSF) data vary widely due to the diverse spatiotemporal stimuli used over the years. To assist selection, this paper: (1) reports measurements of the effects on the CSF of varying the spatial and temporal windows of grating patches; (2) demonstrates that the widely discrepant CSFs from previous studies can be accounted for by using these results; and (3) discusses simple criteria for choosing CSFs for practical applications. CSFs were measured for several combinations of spatial and temporal waveforms, using the same subjects under otherwise identical conditions. The CSF was measured over the range of 0.5-10 c/deg using Gabor-type patches of 1.0-, 0.5-, 0.25-, and 0.125-octave spatial bandwidths using both abrupt and gradual temporal presentations. The results were compared with the CSF obtained with a fixed aperture (4 deg x 4 deg) grating pattern. Increasing the number of cycles resulted in increased sensitivity at intermediate frequencies, changing the CSF to a narrower bandpass shape. For each patch bandwidth, the gradual presentation CSF had a narrower spatial pass band than with the abrupt presentation. The relevance of the large differences in the CSFs obtained with different stimuli to our understanding of visual performance is discussed.

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The usefulness of nontraumatic methods for measuring the left ventricular isometric contraction period (ICP) in myocardial infarction (MI) has been evaluated. The ICP was measured in 13 normal men and 38 patients admitted to a coronary care unit with chest pain, including 18 with acute MI, 12 with old MI, and nine with chest pain of miscellaneous origin; one of these nine was also included in the group with acute myocardial infarction. ICP was determined by three different methods: (1) time between the onset of systolic wave (A) of apexcardiogram (ACG) and the beginning of upstroke (C) of carotid pulse tracing (CPT); (2) time between A and ejection crest (E) of the ACG; and (3) time between the initial low frequency, low amplitude vibration of the first heart sound, and the C of CPT. Statistically significant differences of ICP between the normal group and the three groups of patients were demonstrated only by method 1. Likewise, acute coronary ligation in seven dogs produced characteristic changes in ICP by method 1, which were associated with a reduction in the left ventricular (LV) stroke volume, LV dp/dt, and the aortic flow velocity. The ICP obtained by method 1 appears to be of value in the bedside evaluation of acute myocardial infarction. Additional Indexing Words: Abnormal apexcardiogramEarly systolic bulge First heart sound ATTEMPTS to quantitate circulatory function in acute myocardial infarction have been limited because of the transient nature of the hemodynamic changes and the fear of undertaking elaborate diagnostic procedures in patients with major illnesses. However, recent advances in technics for the recording