Role of contact and soluble factors in the growth and differentiation of B cells by helper T cells.
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Biomedical subjects
Publications and source records attributed to L Marshall.
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Thirty-two cases of proved pineal tumor were analyzed. Calcification was seen in 75%. The size, character, and position of the calcification were useful indicators of abnormality on plain-film evaluation. Fray's cranioangle method was more sensitive than Oon's method in determining abnormal position of the calcified pineal tumor on the lateral skull film. Most calcifications were displaced postero-inferiorly or inferiorly, which can be explained by obstructive hydrocephalus or direct tumor expansion.
Middle-ear reflex activity was measured in 14 listeners in response to visual and acoustic exposure to each of seven noisy toys (such as a cap gun, party horn, cow bell, and so forth). Anticipatory middle-ear reflex (AMER) activity was a common occurrence. Normal middle-ear reflex generally occurred after the sound exposure. AMERs generally occurred in the two seconds prior to sound exposure but as early as 10 seconds before sound exposure. Loudness ratings and exposure SPLs were obtained. The presence of acoustically evoked middle-ear (ME) reflex activity and AMERs to the toys was generally unrelated to SPL or reflex threshold. Many reflex responses occurred in response to exposure SPLs below reflex threshold and with low anticipated loudness rating.
The intelligibility of recorded sentences, distorted by binaural switching, interruption, and low-pass filtering, was investigated in 53 children ranging in age from five to eleven and in adults. All had normal hearing. The sentence vocabulary was pretested for comprehension, articulation errors were evaluated in a way so as not to influence test results, and length and structure of the sentences were controlled. The results indicated that although the performance of children increased with age, the 11-year-old group had not attained adult performance. Error analyses showed that most errors for all age groups were acoustically unrelated to the distorted message, although adults made more acoustically related errors than did children. When children made errors in sentences, other errors (e.g., substitutions) were made to preserve the syntax or semantic integrity of the message.