Parallel Talk Research Articles

Nonradial and radial oscillations observed in non-emission line OB dwarfs and giants

Only a decade ago, this talk could have concerned only the β Cephei stars which however populate a much more precisely defined strip in the Hertzsprung-Russel diagram (MED). But recent reconnaissance surveys (Smith 1977; Smith and Penrod 1984; Waelkens and Rufener 1985; Baade, in preparation) show that perhaps only one, if any, sizeable region of the upper HRD is devoid of nonradially pulsating stars. The identification of the driving mechanism is still pending (cf. the parallel talk by Osaki), and apparently our knowledge about the internal structure of OB stars is incomplete. But, turning that argument around, it also is indicative of how much may be learned about OB stars from and through the solution of that fundamental problem. This seismologial potential, the ubiquity of the phenomenon, and the effect, as suggested by recent observations of some stars, of the pulsations on the mass loss of OB stars make the oscillations of OB stars one of the most important problems of current astrophysics. On the observational side, rotationally broadened spectral lines, large amplitudes, comparatively long periods, and high luminosities permit information to be gathered which otherwise is accessible only for the sun.

Effect of Negative Verbal Stimuli on the Occurrence of Negation in Language Samples

This study compared the number of negative responses obtained in two language sampling conditions. One language sample was elicited using parallel talk containing negative constructions. A second sample was elicited using parallel talk containing affirmative constructions. The order of experimental conditions was randomized for each of the eighteen kindergarten children studied. The same clinician and materials were used in each condition. The results showed no significant differences between the two language sampling conditions. The negative parallel-talk stimuli did not elicit more negative responses than did the affirmative parallel-talk stimuli. The results are interpreted in terms of eliciting language samples for normative comparisons and elicitng samples that attempt to insure the use of negatives.