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Biomedical subjects

B L Anderson

Publications and source records attributed to B L Anderson.

6 recordsLinked to original sources
PubMed1992

Temporal factors in the discrimination of coherent motion.

When observers view the relative movements of a pair of bars defined by the difference of spatial Gaussian functions (DOGs), they can accurately discriminate coherent movements over a range of temporal frequencies and temporal asynchronies. Of particular interest is the fact that performance accuracy is maintained even when the two bars differ in spatial-frequency content and contrast. On each trial, observers viewed two brief presentation intervals in which a pair of vertically oriented DOGs moved randomly back and forth within a restricted range. During one observation interval, both elements moved in the same direction and by the same magnitude (correlated), and in the other interval, the movements were independent (uncorrelated). Temporal asynchronies were introduced by delaying the displacement of the right bar relative to that of the left bar in each interval. Observers were able to discriminate correlated versus uncorrelated movements up to a 45-60-msec temporal delay between the two elements' relative displacements. If motion processing is accomplished by mechanisms operating over multiple spatial and temporal scales, the visual system's tolerance of temporal delays among correlated signals may facilitate their space-time integration, thereby capitalizing on the perceptual utility of coherent-motion information for image segmentation and interpolating surface structure from the movements of spatially separated features.

Adult↗
PubMed1992

Hysteresis, cooperativity, and depth averaging in dynamic random-dot stereograms.

Experiments were performed to assess the response of the human visual system to dynamic random-dot patterns composed of disparity mixtures. In Experiment 1, the perceived depth and relative stability of two patterns were compared; one pattern depicted two transparent layers of dots, and the other depicted a volume of dots. Two effects were found: (1) the volume pattern exhibited a large degree of disparity averaging; and (2) asymmetries were observed in the relative stability of these two patterns. Experiment 2 was designed to determine whether these findings could be attributed to spatially localized processes occurring at the location of disparity discontinuities. This was accomplished by introducing unpaired noise points localized either along the disparity discontinuities or in the center of the layered and volume patterns. The amount of depth averaging and the direction of the asymmetry did not appear to depend on processes localized along the disparity discontinuities. Results of these experiments, taken in conjunction with those of previous studies, suggest that hysteresis is independent of cooperative persistence mechanisms.

Adult↗
PubMed1990

Energy expenditure and physical performance in overweight women: response to training with and without caloric restriction.

The metabolic effects of exercise training and the influence of a moderate calorie restriction on the training response were examined in overweight women. Ten healthy women, 119% to 141% of desirable weight, completed the 14-week study. After a 2-week stabilization period, in which diets were designed to maintain body weight (BW), five women were assigned to a 12-week experimental program of diet and exercise (D + EX) that included a 50% reduction in energy intake and a program of moderate intensity aerobic exercise 6 days per week. The other five women were assigned to the same daily exercise (EX) and continued to consume the stabilization diet. Periodic measurements of resting metabolic rate (RMR), thermic effect of food (TEF), energy cost of exercise, and predicted maximal aerobic capacity (VO2 max) were obtained, and the respiratory quotient (RQ) was determined during rest and exercise. Body composition was monitored weekly. Tests of strength and anaerobic capacity were conducted. D + EX lost an average of approximately 1.1 kg/wk, which was 67% fat, 33% lean. EX lost approximately 0.5 kg/wk, which was 86% fat, 14% lean. In both groups, the exercise program resulted in an 11% to 13% improvement in VO2 max and an 8% to 16% decrease in energy expenditure at submaximal workloads. The caloric restriction significantly increased fat utilization during exercise. The RMR declined 9% in D + EX, from 1,550 to 1,411 kcal/d, whereas it was maintained in EX, 1,608 to 1,626 kcal/d. The decrease in RMR observed in D + EX was consistent with the loss of fat-free mass (FFM).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1975

Evolutionary dental changes.

In the evolution of primates there has been a tendency towards reduction in jaw length and prognathism, mandibular canine size and first molar cusp number, and third molar presence. These oral structures were contrasted, and compared with cranial size, body height and weight, and finger length in 118 males and 102 females of the Burlington Growth Centre. Body weight was significantly related to canine width and to jaw length and prognathism. These relationships were stronger in the males than in the females. The evolutionary reduction in these dental dimensions may result from an evolutionary reduction in genetically determined body size. In the males the number of molar cusps was related to finger length and cranial height. Agenesis of third molars was related to the length of the maxilla in both sexes. In the females, canine width was related to the number of cusps of the first molars, agenesis of third molars, and length of a finger. Simultaneous reductions in dental structures were more frequent in the females.

Adolescent↗
PubMedDate not supplied

Nursing informatics: career opportunities inside and out.

As more and more health care organizations adopt computerized information systems, and as the first faint beginnings of a trend toward implementation of computerized nursing information systems make themselves felt, nurses from all areas are being drafted into computer-related occupations. That there is a need for more and better computer education in baccalaureate, graduate, and clinical areas is becoming self-evident as well. Meanwhile, job opportunities in the field now known as nursing informatics are becoming available, and computer-savvy nurses must be ready, able, and willing to take the best advantage of these opportunities.

Career Mobility↗