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Biomedical subjects

D G Richards

Publications and source records attributed to D G Richards.

25 records · Page 2Linked to original sources

The radiological appearance of artificial urinary sphincters.

The increasing refinement of artificial anti-incontinence devices has provided new hope for incontinent patients. The aim of this paper is to show the design and function, and to indicate the use of radiology in evaluation of function, of the latest prostheses. The complications peculiar to these devices are illustrated and the use of radiology in identifying these complications is indicated.

Humans↗

Vocal mimicry of computer-generated sounds and vocal labeling of objects by a bottlenosed dolphin, Tursiops truncatus.

A bottlenosed dolphin (Tursiops truncatus) was trained to mimic computer-generated "model" sounds, using a whistle mode of vocalization. Prior to training, the whistle sounds of this dolphin were limited to a few stereotyped forms, none of which resembled the model sounds. After training, high-fidelity imitations were obtained of model sounds having (a) moderately or widely swept, slow-rate frequency modulation (1-2 Hz), (b) narrowly or moderately swept frequency modulation at moderate to rapid rates (3-11 Hz), (c) square-wave frequency transitions, and (d) unmodulated (pure-tone) waveforms. New models, not heard previously, could be mimicked immediately, often with good fidelity, including mimicry of amplitude variation that had not been explicitly reinforced during training. Subsets of familiar models were mimicked with high reliability in repeated tests. In additional training, control of the mimic response was transferred from the acoustic model to objects shown the dolphin (e.g., a ball or a hoop) so that, in effect, the dolphin gave unique vocal labels to those objects. In a test of accuracy and reliability of labeling, correct vocal labels were given on 91% of 167 trials comprised of five different objects presented in random order. The dolphin's ability for vocal mimicry compared favorably with that of the more versatile mimic birds, and it contrasted sharply with the apparent lack of vocal mimicry ability in terrestrial mammals other than humans. The ability to label objects vocally was similar to abilities shown for some birds and similar, in principle, to abilities of great apes trained in visual languages to label objects through gestures or other visual symbols.

Animals↗

Single-dose intraoperative antibiotic prophylaxis in emergency abdominal surgery.

In a randomized controlled trial of the use of a single intravenous dose of gentamicin sulfate and clindamycin phosphate used intraoperatively during emergency abdominal surgery, the overall incidence of postoperative wound infection was reduced from 32.3% to 10.4%. Significant reduction in wound infection occurred in the study group compared with control subjects irrespective of the underlying pathologic lesion. No side effects of the use of antibiotics were noted. The policy of antibiotic prophylaxis in emergency surgery seems to be of particular benefit in elderly patients.

Abdomen↗