Biomedical subjects

M Dysart

Publications and source records attributed to M Dysart.

3 recordsLinked to original sources

PubMed1991

The incidence of meconium-stained amniotic fluid from 1980 through 1986, by year and gestational age.

The annual incidence of meconium-stained amniotic fluid was analyzed for changes in a total obstetric sample of 45,115 singleton, vertex, liveborn infants over a 7-year study period. The incidence of meconium-stained amniotic fluid for the total obstetric population was calculated for each year of the study period. The sample was then stratified by estimated gestational age, and the incidence of meconium-stained amniotic fluid was calculated for each gestational age group. The incidence of meconium-stained amniotic fluid increased 40.9% over the study period, from 18.8% in 1980 to 26.5% in 1986 (P less than .001). This increase was found to be in a consistent linear trend (P less than .05). The incidence of meconium-stained amniotic fluid was also found to increase significantly in a linear trend as gestational age of the fetus increased. These findings lend support to both the maturational theory and the stress theory of meconium passage in utero.

Amniotic Fluid↗

PubMed1984

Differences in visual sensitivity among mindfulness meditators and non-meditators.

Tachistoscopic presentation of light flashes was used to test for differences in visual sensitivity among 3 groups of practitioners of Buddhist mindfulness meditation and non-meditator-controls. Meditation practitioners were able to detect light flashes of shorter duration than the non-meditators. There were no differences among the meditator groups. There were no differences among the groups in ability to discriminate between closely spaced successive light flashes. The lower detection threshold for single light flashes for the meditators may reflect an enduring increase in sensitivity, perhaps the long-term effects of the practice of mindfulness meditation on certain perceptual habit patterns. The lack of significant differences in the discrimination of successive light flashes probably reflects the resistance of other perceptual habit patterns to modification. The results support the statements found in Buddhist texts on meditation concerning the changes in perception encountered during the practice of mindfulness.

Buddhism↗

PubMed1984

Visual sensitivity and mindfulness meditation.

Practitioners of the mindfulness form of Buddhist meditation were tested for visual sensitivity before and immediately after a 3-mo. retreat during which they practiced mindfulness meditation for 16 hr. each day. A control group composed of the staff at the retreat center was similarly tested. Visual sensitivity was defined in two ways: by a detection threshold based on the duration of simple light flashes and a discrimination threshold based on the interval between successive simple light flashes. All light flashes were presented tachistoscopically and were of fixed luminance. After the retreat, practitioners could detect shorter single-light flashes and required a shorter interval to differentiate between successive flashes correctly. The control group did not change on either measure. Phenomenological reports indicate that mindfulness practice enables practitioners to become aware of some of the usually preattentive processes involved in visual detection. The results support the statements found in Buddhist texts on meditation concerning the changes in perception encountered during the practice of mindfulness.

Buddhism↗