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Biomedical subjects

L L Davis

Publications and source records attributed to L L Davis.

At least 73 records · Page 4Linked to original sources
PubMed1987

Use of active head movements for computerized vestibular testing.

The vestibulo-ocular reflex (VOR) is seldom tested above 2 Hz, in spite of the higher-frequency components that stimulate it during natural head movements. We tested the horizontal VOR in ten normal subjects during 18 s of active, side-to-side head motion over a frequency range from 2 to 6 Hz. Audible clicks were used as a linearly increasing frequency cue. Head velocity was monitored. The two experimental conditions were head movement while fixating a stationary wall-mounted target in dim light, and head movement in darkness with an imagined stationary target. Computed gain and phase results of the two test conditions were not significantly different, due to inactivation of the smooth pursuit system above 2 Hz. We conclude that higher-frequency VOR responses can be tested in the light by a brief, low-cost test, which does not require expensive rotating machinery.

Adult↗
PubMed1985

Perceived somatotype, body-cathexis, and attitudes toward clothing among college females.

The purpose of this study was to investigate the relationship between perceived somatotype and body-cathexis for female subjects and to determine the perceived ideal somatotype of college females. The relationship between perceived somatotype and attitudes toward fashion and clothing use was also examined. 91 female undergraduates were administered the Perceived Somatotype Scale, the Body-cathexis Scale, and several measures of fashion and clothing interest and use. Analysis of variance indicated that the ectomorphic build was perceived as the ideal somatotype for college females. As subjects' self-perceived somatotype deviated from the ideal and moved toward the mesomorphic and endomorphic, body-cathexis scores decreased. Contrary to stereotypic assumptions, perceived somatotype was unrelated to the fashion and clothing measures.

Adult↗
PubMed1984

The co-ordination of chitosan and chitin synthesis in Mucor rouxii.

Chitin synthetase preparations from cell walls and chitosomes of the fungus Mucor rouxii were tested for their ability to synthesize chitosan when incubated with uridine diphosphate N-acetyl-D-glucosamine in the presence of chitin deacetylase. The most effective chitin synthetase preparation was one dissociated from cell walls with digitonin. The rate of chitosan synthesis by the wall-dissociated chitin synthetase was about three times that of an equivalent amount of cell walls. The chitosan-synthesizing ability of chitosomes was relatively low, but was more than tripled by treatment with digitonin. Presumably, digitonin improves chitosan yields of dissociating chitin synthetase. The dissociated enzyme would produce dispersed chitin chains that could be attacked by chitin deacetylase before they have time to crystallize into microfibrils. The regulation of chitin and chitosan syntheses in vivo may be determined by the organization of chitin synthetase molecules at the cell surface. Those molecules that remain organized as a complex, similar if not identical to that found in chitosomes, would produce mainly chitin. Chitosan would be preferentially produced by chitin synthetase molecules which are dispersed upon reaching the cell surface.

Cell Wall↗
PubMed1983

Pulmonary "mainline" granulomatosis: talcosis secondary to intravenous heroin abuse with characteristic x-ray findings of asbestosis.

A 50-year-old man, a "mainline" heroin abuser for 25 years, with a five-year history of x-ray findings compatible with asbestosis is presented. Multiple open biopsies failed to prove a diagnosis of asbestosis. The microscopic analyses of tissues revealed the presence of granulomatosis, secondary to talc from chronic intravenous heroin abuse. The need for open lung biopsy in establishing a diagnosis is emphasized, as x-ray findings can be and often are misleading. A tissue diagnosis is necessary, particularly in cases in which drug abuse is suspected.

Asbestosis↗
PubMed1978

Presence of arylsulfatase A (ARS A) in multiple sulfatase deficiency disorder fibroblasts.

Multiple deficiency disorder fibroblasts cultured in MEM-CO2 showed deficiencies of arylsulfatase A(ARS A) comparable to the deficiency in metachromatic leukodystrophy fibroblasts. However, the MSDD fibroblasts cultured in MEM-HEPES contained near normal levels of ARS A. Moreover, the enzyme from the latter fibroblasts was indistinguishable from ARS A of control fibroblasts on DEAE-cellulose chromatography, ratio of activity with several substrates, thermal inactivation, sensitivity to inhibitors, and precipitation by antiserum to human ARS A. These data support the conclusion that the ARS A genome is intact in MSDD fibroblasts and, by extension, in MSDD patients. Other sulfatases were present at levels ranging from mildly deficient to near normal but never as low as seen in the corresponding specific sulfatase deficient disorders.

Cell Line↗
PubMed1977

Media for an integrated nursing curriculum.

In conclussion, the media decision-making process for an integrated nursing curriculum is based upon the following steps: - An analysis of the philosophy and unifying strands in the conceptual framework of the curriculum model, - An evaluation of currently owned media in terms of the theoretical framework and educational objectives of the model, - An assessment of commercial media with realistic planning for purchase and/or production, and - The development of a systematic ongoing evaluation process by students, faculty, and nursing service personnel. The focus of this discussion has been clarification of the assessment and planning steps necessary in the media decision-making process for an integrated nursing curriculum. While these steps are applicable to any educational model, they have particular relevance to a curriculum model in which concept learning and interrelationships are stressed.

Audiovisual Aids↗