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Biomedical subjects

D Marsland

Publications and source records attributed to D Marsland.

At least 19 recordsLinked to original sources
PubMed1994

Disability abated: audio-cassettes for the visually impaired.

The paper reports on aspects of a nation-wide interview study of a sample of 320 visually impaired people. Visually impaired people are evidently keen to keep abreast of news and current affairs. They answer their needs in this respect to a modest extent through braille material, and on a large scale by means of television and especially radio. Audio-cassettes play a surprisingly important role, particularly recordings of newspapers and other periodicals. They are used regularly by a large majority of blind people. Reactions to audio-cassettes are enormously positive. They appear to provide not only information, but also companionship, purpose and meaning. The survey suggests that need and demand for a nation-wide audio-cassette service is substantial.

Aged↗
PubMed1992

Nursing evaluation: purposes, achievements and opportunities.

Evaluation has become a powerful, specialized discipline in recent decades, with its own sophisticated conceptual and technical apparatus. Evaluation of nursing has benefited strongly from these developments, as examples of cogent, recent evaluations demonstrate. Evaluation is already proving an indispensable practical tool for raising the quality of health care, and for advancing professional nursing standards. Nonetheless, there is room for further improvement. Neglected areas of nursing should be brought under the spotlight of evaluation, conceptual and methodological rigour should be strengthened, and training in research skills should be extended.

Clinical Protocols↗
PubMed1986

Denominator definition by the utilization correction factor method.

Most clinical research in the United States has been carried out in atypical populations. This study, done in a network of primary care populations in Virginia, calculates the denominator by the utilization correction factor method and compares the demography with that of the population of the state. The demographic characteristics of the patients in the network are very similar to those of the underlying populations and on the same order of state-of-the-art sampling methods in current use.

Adolescent↗
PubMed1975

A systems approach to patient care, curriculum, and research in family practice.

The system of data recording and retrieval which defines a family practice population of patients is described. It is organized at two levels, as a series of manual instruments or as a single instrument used as data input to a computer. Depending on resources available, it is possible to record demographic and morbidity data from the patient populations of both teaching and nonteaching practices. Data have been collected from a patient population of 88,000 in 26 practicing sites in Virginia, totaling 380,000 diagnostic and follow-up visits. Presentations are made of some of this data. The costs of this recording process in nonteaching practices, the use of such data as an educational resource for the training of primary care physicians, and the evaluations of health care delivered are discussed.

Curriculum↗
PubMed1969

A fine structural analysis of cleavage induction and furrowing in the eggs of Arbacia punctulata.

A fine structural study has been carried out on the various formed elements present before, during, and after the first cleavage division, not only in normally developing Arbacia eggs, but also in eggs which have been induced to cleave prematurely by high-pressure centrifugation. The aim has been to ascertain whether or not any of the morphologically identifiable components may be involved in initiating the furrowing process. Also, attention has been given to the fine structure of the cytoplasmic cortex, particulary in the walls of the furrow, in the hope of reaching a better understanding of the mechanics of cleavage. The annulate lamellae and the membranous envelope of the nucleus are the only formed elements which disappear shortly before cleavage, not only in eggs undergoing normal division, but also in eggs which have been induced to cleave ahead of schedule by high-pressure, high-force centrifugation. Therefore, it is suggested as a tentative hypothesis that materials liberated upon disintegration of the nuclear membrane and the annulate lamellae play an essential role in initiating and effecting the furrowing reaction, especially since the stratification of these elements in experimentally induced eggs corresponds to the position of the developing furrow. Another of the membranous elements in the egg, the Golgi complex, shows considerable modification as a result of high-pressure centrifugation, but these structures do not undergo disintegration. Rather, they become curled into rounded bodies. The vacuole population is not greatly affected by inducing treatments. During cleavage, both naturally occurring and experimentally induced, a considerable number of 50 A filaments appear in the denser cytoplasmic cortex, but only in the walls of the furrow. These filaments are similar to those which have been demonstrated in a number of contractile cells. Accordingly, it is suggested that this fibrillar system may be actively involved in the development of the cleavage force.

Animals↗
PubMed1966

Studies on the microtubules in heliozoa. 3. A pressure analysis of the role of these structures in the formation and maintenance of the axopodia of Actinosphaerium nucleofilum (Barrett).

Electron microscope preparations were made of specimens of Actinosphaerium nucleofilum fixed in glutaraldehyde before, during, and after exposure to high pressures (4,000 to 8,000 psi). A study of this material showed that, although other organelles were relatively stable, the microtubular elements of the axopodia and cytosome became unstable under pressure. Their rapid disintegration under pressure was correlated with beading and retraction of the axopodia. Moreover, after the release of pressure, microtubules reappeared as soon as, or sooner than the reextension of the axopodia. The rate of disintegration increased as the pressure was raised. At 4,000 psi, few if any tubules remained after 10 min, whereas at 6,000 and 8,000 psi the disintegration was much more rapid. Some adaptational reorganization of the microtubules and axopodia occurred while relatively low pressures were maintained. This was accompanied by an actual elongation of the axopodia in specimens maintained for 20 min at 4,000 psi, but was confined to knoblike axopodial remnants in animals kept at 6,000 psi. No regeneration of tubules or axopodia occurred at 8,000 psi. The presence of fibers and a finely fibrillar material in pressurized animals suggests that these may be derivatives of microtubular disintegration. This evidence, though purely morphological, is consistent with the hypothesis that microtubules play an important role not only in maintaining the formstability of the axopodia, but also in the active process by which the axopodia reextend themselves after retraction.

Eukaryota↗