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Biomedical subjects

D Ling

Publications and source records attributed to D Ling.

At least 55 records · Page 3Linked to original sources
PubMed1982

Cued Speech and the reception of spoken language.

This study was designed to investigate the effect of Cued Speech on the speech reception abilities of profoundly hearing-impaired children under seven conditions of presentation: audition; lipreading; audition and lipreading; cues; audition and cues; lipreading and cues; and audition, lipreading, and cues. The 18 subjects had been taught through the use of Cued Speech for at least 4 years. The subjects were presented with specially designed speech tests (syllables and key words in sentences) which had been recorded on color videotape, and they responded in writing. Speech reception scores of over 95% with the key word in sentence materials and over 80% with the syllables were obtained with lipreading plus cues, and with audition, lipreading plus cues. Equally high levels of accuracy in speech reception by such children have not previously been reported. The subjects also demonstrated the ability to use audition with the sentence materials, both in combination with lipreading and with cues, though there were large individual differences under these conditions. Speech reception abilities in the lipreading-plus-audition condition were highly correlated with scores for speech production, whereas language attainments were correlated with reception through Cued Speech. The implications of these findings to the field of aural rehabilitation are discussed.

Adolescent↗
PubMed1981

Effects of ischemia on left ventricular regional function in the conscious dog.

Three-dimensional regional geometry of the left ventricle was assessed in seven conscious trained dogs chronically implanted with pulse-transit ultrasonic-dimension transducers. Minor and major axis segment lengths and wall thickness were measured in the distribution of the left anterior descending coronary artery; transmural pressure (TMP) was measured with high-fidelity micromanometers. Data were recorded during the control state and following 30 s and 30 min of ischemia. Dimensions were normalized as a fractional extension from the length at zero TMP (Lo). Dynamic cube mass was calculated and remained constant throughout the cardiac cycle in both control and ischemic states, although the calculated mass decreased by an average of 5% during ischemia. The slope constants of the exponential diastolic pressure-dimension relationship increased following acute coronary occlusion indicating increases in regional myocardial stiffness with increasing periods of ischemia. Coronary occlusion also was associated with an increase in the Lo measurements in the major and minor axis dimensions and a decrease in the wall thickness Lo. These findings are consistent with an ischemia-induced plastic deformation of the regional myocardium defined as creep. Thus, acute ischemia results in a decline of regional systolic function, induces myocardial creep, and causes an immediate and sustained increase in regional myocardial stiffness.

Animals↗
PubMed1979

Regional diastolic mechanics of the left ventricle in the conscious dog.

In eight chronically instrumented conscious dogs, apical and middle left ventricular transverse diameters were measured with pulse-transit ultrasonic dimension transducers. Intracavitary apical and midventricular pressures and intrapleural pressure were measured with micromanometers. Both diameters were normalized as a percent extension from the dimension at zero transmural pressure, determined during a transient vena caval occlusion. During the rapid phase of diastolic filling, there was a 2--5 mmHg pressure gradient from the midventricle to the apex. During late rapid filling, the apical transmural pressure and diameter increased more rapidly and reached diastasis 17 +/- 4 ms earlier than the corresponding midventricular measurements (P less than 0.01). The static diastolic pressure-dimension characteristics at the apical and midventricular levels were not significantly different (P greater than 0.30). The dynamic diastolic pressure-dimension relationship was also similar at the two levels and could be represented by a model incorporating parallel viscous properties. Because of regional differences in pressures and dimensions, however, the dynamic relationship could not be modeled when pressure was compared to the dimension at a different level. Thus, diastolic pressures should be measured at the same level as dimensions when assessing left ventricular diastolic mechanics.

Animals↗
PubMed1979

The Nakasuk Project- the conservative treatment of chronic otitis media in Inuit elementary school children.

Modalities of local medical treatment of chronic otitis media in Inuit elementary school children were evaluated over a period of three and a half years in a project associated with the provision of amplification (hearing aids) for students who had significant conductive hearing deficits which interfered with their ability to communicate. The significant medical and educational benefits derived are reviewed.

Acetates↗
PubMed1978

Genetic aspects of the BOR syndrome--branchial fistulas, ear pits, hearing loss, and renal anomalies.

A pedigree of branchio-oto-renal dysplasia (the BOR syndrome) is reported, including the documentation by serial audiometric studies of the onset and rapid progression of hearing loss in the twin sister of an affected child. The literature on this syndrome is analyzed to derive some figures for use in genetic counseling of such families. Branchio-oto-renal dysplasia is an autosomal dominant disorder in which affected individuals may have preauricular pits, lachrymal duct stenosis, hearing loss, branchial fistulas or cysts, structural defects of the outer, middle, and inner ear, and renal anomalies, which may range from mild hypoplasia to complete absence. Not all features of the syndrome are expressed in all carriers of the gene, but few carriers lack all the features, and the pits, branchial clefts, and hearing loss, are frequently expressed. Those offspring of affected persons who have pits or fistulas are likely (about 80%) to have hearing loss of varying degrees of severity. A minority of heterozygotes (about 7%) may have hearing loss without pits or fistulas. The risk of severe renal malformation is probably fairly low. Whether families that show dominant inheritance of pits, clefts, and deafness without renal anomalies represent variants of the BOR syndrome or a separate entity (the BO syndrome), is still not clear. At present, any individual with preauricular pits and branchial clefts deserves both otologic and renal investigation.

Abnormalities, Multiple↗
PubMed1978

Speech development in hearing-impaired children.

Many hearing-impaired children are unable to speak intelligibly. Research indicates, however, that patterns of errors typically found in the speech of such children could be largely avoided by systematic teaching. The purpose of this paper is to present and discuss a model for the progressive development of speech skills to the levels of automaticity required for fluent spoken language.

Child↗
PubMed1977

Rehabilitative treatment of hearing-impaired children.

The prevalence of hearing impairment and the educational effects of untreated hearing problems are described and the conditions required for verbal learning among severely and profoundly hearing-impaired children are outlined. Results of a longitudinal study undertaken at McGill University are briefly presented and the spoken language skills acquired by profoundly hearing-impaired children enrolled in this study are discussed.

Child↗
PubMed1976

The three-dimensional dynamic geometry of the left ventricle in the conscious dog.

The dynamic geometry of the left ventricle was assessed with the use of chronically implanted pulse-transit ultrasonic dimension transducers. The orientation of the transducers allowed the measurement of left ventricular minor and major axis diameters and equatorial wall thickness in the conscious dog. The left ventricle was modeled as a three-dimensional, prolate ellipsoidal shell. Left ventricular and pleural pressures were measured with high fidelity micromanometers. Aortic blood flow was obtained with electromagnetic flow probes. To test the assumptions inherent in this technique, left ventricular mass, internal volume, stroke volume, and peak aortic flow were computed from the dimension data and compared to directly measured values. Correlation coefficients of 0.95 or greater were obtained for each of these comparisons. In addition, the calculated left ventricular mass was constant to within +/- 6% of the mean value throughout the cardiac cycle. We found that the dynamic contraction pattern of the left ventricle was dependent on the physiological state of the dog. Furthermore, in the conscious state, shortening of the minor axis diameter, lengthening of the major axis diameter, and slight thickening or thinning of the wall were noted during isovolumic contraction (isovolumic ellipticalization pattern). In the open-chested, anesthetized state, however, marked rearrangements in geometry were observed during isovolumic contraction manifested by lengthening of the minor axis diameter, and significant thickening of the wall (isovolumic sphericalization pattern). We also observed that left ventricular volume was significantly diminished in the open-chested state. The isovolumic contraction pattern in open-chested dogs could be changed from sphericalization to ellipticalization by increasing end-diastolic volume with the infusion of saline. During a vena caval occlusion in the conscious state, the contraction pattern changed from isovolumic ellipticalization to isovolumic sphericalization as the end-diastolic volume decreased. Thus, the exact pattern of left ventricular contraction was found to be a function of left ventricular volume.

Animals↗