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Biomedical subjects

R J Biersner

Publications and source records attributed to R J Biersner.

At least 37 records · Page 2Linked to original sources
PubMed1980

Comparisons of performance effectiveness among divers.

Using a criterion of performance effectiveness derived from actual dives made under operational conditions, comparisons were made between U.S. Navy divers identified as high and low in performance effectiveness. Comparison measures included intelligence, anxiety, disciplinary problems, and incidence of decompression sickness (DCS). As expected, the most effective divers made more frequent and more hazardous dives than the least effective divers. In addition they had fewer diving accidents and a lower incidence of DCS. While the most effective divers had lower intelligence scores than the least effective group, both groups were substantially above the Navy average. These findings indicate that intelligence appears to be a critical variable in the career retention of divers, as well as the frequency and types of dives to which divers are exposed. The higher incidence of diving accidents and complications, especially DCS, found among the least effective divers may also have been involved in the lower frequency of diving observed among the members of this group.

Accident Proneness↗
PubMed1979

Human parotid alpha-amylase secretion as a function of chronic hyperbaric exposure.

Secretion of alpha-amylase by the human parotid gland increased significantly during eight days of hyperbaric exposure. This hyperactivity of the parotid gland presumably resulted from increased autonomic nervous system (ANS) activity attributable to (1)psychological stress in the form of anticipation; (2) dive-related factors, i.e., hyperoxia, PN2, physical stress; or (3) a combination of both. The etiology of the effect must await additional studies, but a consistent and significant elevation in alpha-amylas secretion was found. This previously undescribed effect of hyperbaric exposure indicates that parotid alpha-amylase sampling holds promise as a noninvasive means of monitoring physical and psychological stress, and as an indirect measure of ANS tone.

Adult↗
PubMed1978

Aseptic bone necrosis among U.S. Navy divers: survey of 934 nonrandomly selected personnel.

Nine hundred thirty-four U.S. Navy divers were selected and surveyed radiographically using standard techniques developed for detecting aseptic bone necrosis (ABN). X rays were read by qualified radiologists. A total of 16 positive cases was detected, and another 11 were interpreted as doubtful. ABN was found to be related to age and number of months in diving. After controlling for these factors, ABN could not be related to any of seven indices of diving activity. Divers with ABN did, however, have a history of more treatments for decompression sickness (DCS) than did divers without ABN. Implications of these findings are discussed, and the suggestion is made that ABN and DCS may not be related causally, but may be related to a third common factor. The need for controlled studies is discussed. The conclusion is made that the low prevalence rates of ABN among U.S. Navy divers cannot be related to any specific index of diving activity, and may not be causally related to DCS.

Adolescent↗
PubMed1978

Diving experience and emotional factors related to the psychomotor effects of nitrogen narcosis.

Simple and complex psychomotor performance were tested among 21 Navy divers under normal conditions and during nitrogen narcosis in simulated dives to 170 ft of sea water. Complex psychomotor performance was impaired significantly during narcosis, while simple psychomotor performance remained essentially normal. Differences between baseline scores for complex psychomotor performance (pre- and post-dive combined) and scores obtained from the two combined testing sessions administered during narcosis were correlated with official Navy records of diving experience and self-reported moods. None of the diving experience measures was associated significantly with these difference scores. The moods of Fatigue and Happiness were, however, correlated significantly with impairment. These results indicate that, although previous experience with nitrogen narcosis and diving tasks do not mediate the performance effects of nitrogen narcosis, the complex psychomotor effects nitrogen narcosis are related to emotional traits.

Adult↗
PubMed1978

Effect of long-term hyperbaric stress on ammonia metabolism in humans.

A significant increase in blood urea was found in 11 U.S. Navy divers during 8 d of air saturation hyperbaric exposure. Similar increases in blood urea have been found in animals that convulsed during hyperbaric oxygen exposure. Therefore, it is suggested that careful attention be given to blood ammonia and urea levels in humans during long-term hyperbaric exposure.

Adult↗
PubMed1977

Spatial and visuomotor performance with agenesis of the corpus callosum.

The extent to which the cerebral hemispheres and their ipsilateral projection systems compensate for congenital absence of the corpus callosum was studied in an intelligent young adult with radiologically verified total agenesis. She was found to have bilateral speech and the ability to readily integrate visual, tactile, and verbal information simultaneously presented to both hemispheres. However, spatial performance, as demonstrated in blind tactile form board learning, was subnormal compared to normal controls. The results further suggest this impairment, especially severe in the nondominant hand, reflects ipsilateral projection of kinesthetic input, thus maximizing hemispheric competition for motor control of the minor hand. In contrast, the agenic's performance on a simple visuomotor discrimination task (with reduced opportunity for hemispheric interaction) was almost normal. Moreover, she exhibited a doubling of attentional and processing capacity in comparison to the control group. Both hands simultaneously performed this task as rapidly and as accurately as either hand alone. The findings affirm the functionally important, yet limited compensatory role of a developmentally elaborated ipsilateral somatosensory projection system in agenesis of the corpus callosum.

Adult↗
PubMed1976

Occupational differences between conventional and saturation divers.

Diving experiences of 53 Divers First Class attending the U.S. Navy Saturation Diver Training Program were compared to 155 Divers First Class performing routine operational dives. The two groups were matched for years of diving experience, total number of dives, and total number of SCUBA dives. The Diving Experience Questionnaire (DEQ), which consisted of 43 items dealing with specific diving conditions and activites, was used to document the diving backgrounds of the two groups. Five of the 43 items were found to significantly and uniquely differentiate between the two groups. Those attending the Saturation Diving Program a) made more dives between 46-61 m (151-200 ft), b) had more experience with semiclosed-circuit SCUBA, c) attended more deep-diving training courses, d) made fewer dives in water warmer than 70 degrees F, and e) had fewer specialized qualifications outside deep diving. The multiple regression analysis which differentiated between the two groups resulted in an R of 0.48. These five items indicate that volunteering for saturation diving is consistent or congruent with past deep-diving experience, while remaining in conventional diving is congruent with previous shallow-water experience. These results indicate that the DEQ may be a highly useful method of differentiating between experienced divers.

Diving↗
PubMed1976

Associations between psychological factors and pulmonary toxicity during intermittent oxygen breathing at 2 ATA.

Associations between the psychological and pulmonary effects of breathing intermittent oxygen at 2 ATA were examined among four experienced divers. A fifth diver, who served as a control, breathed only normoxic nitrogen. Psychological tests included digit span, short-term memory for easy and difficult word associations, simple and complex psychomotor performance, and reported moods. The criterion of oxygen toxicity was the total hours of intermittent oxygen exposure tolerated before developing a 10% reduction in vital capacity. Short-term memory for difficult word associations and self-reported moods of Activity, Depression, Fatigue, and Happiness were found to be significantly correlated with this criterion of oxygen toxicity. Part of the impairment found on these measures, however, was probably related to the absence of adequate sleep and rest as evidenced by the worsened performance of the control diver over the 15-h testing period. The results replicated the findings of earlier research on the psychological effects of continuous oxygen breathing under hyperbaric conditions and at 1 ATA, and may indicate that oxygen intesifies the effects of other stressors such as fatigue. In addition, the results showed that reported moods may be important indicators of impending pulmonary toxicity during intermittent oxygen exposure.

Activities of Daily Living↗
PubMed1976

Serum uric acid, cholesterol, and psychological moods throughout stressful naval training.

Navy recruits, all 51 volunteers for a preliminary underwater demolition team (UDT) training program, were followed through 4 weeks of training; 27 men passed and 24 failed the training course. Serum uric acid and serum cholesterol levels, as well as psychological moods data were collected on all volunteers at the start of training and at the end of each of the four training weeks. Men who passed training were compared to those who failed. In addition, these same measures were carried out with a control group of 66 naval recruits. Pre-UDT trainees who passed the program demonstrated high levels of positive moods, early peaks in serum uric acid level, and stable serum cholesterol levels throughout training. These findings supported previous work with successful UDT trainees. Pre-UDT trainees who failed the program demonstrated intermediate levels of positive moods, a midtraining period peak in serum uric acid, and a significant rise in serum cholesterol during the final 2 weeks of the course. The serum cholesterol rise seen during a period shortly prior to failure substantiates previous findings. A comparison group showed low levels of positive moods, an initial peak in serum uric acid, and stable serum cholesterol levels. Two mood scales had siginificant correlations with serum uric acid for only men who passed training. A motivation scale, given at the start of training, correlated with serum uric acid levels for men who failed training.

Cholesterol↗
PubMed1975

Factors in 171 navy diving decompression accidents occurring between 1960-1969.

Comparisons were made between the incidence of specific factors in U.S. Navy decompression accidents and the incidence of these factors in routine (nonexperimental) U.S. Navy operational dives. It was found that decompression accidents are disproportionately high among a) air dives less than 140 ft which have bottom times of 30 min or less and air dives greater than 140 ft which have bottom times of more than 15 min, b) Divers First Class, c) older divers, and d) dives which do not involve work or divers which require heavy work. Repetitive dives have a lower decompression accident rate than expected. Decompression accidents were not disproportionately high for any category of body build. These results indicate that the present U.S. Navy decompression tables are extremely safe (5 decompression accidents/10,000 dives), and do not appear to require modification. Future decompression research may be directed toward analyzing the relationship of work and aging to physiological processes involved in decompression. In addition, the present findings should be cross-validated using more recent accident and operational diving data.

Accidents↗
PubMed1975

Psychological characteristics of deep submergence vehicle personnel.

The personality and developmental characteristics of U.S. Navy Deep Submergence Vehicle (DSV) personnel, including operators and crews, were documented and compared to the characteristics of U.S. Navy divers. The results show that DSV operators (DSV Oprs) had a significantly less asocial developmental pattern than divers, while developmental experiences of DSV crews (DSV Crs) were similar to those of divers. Personality measures (EPPS) indicate that both DSV Oprs and DSV Crs are presently more sociable as adults than divers and would probably be more effective in situations involving small group interaction. The modifications which have occurred in the behavior of DSV Crs may be related to experience in the highly interpersonal DSV situation. The findings also show that DSV Oprs prefer to take fewer risks than divers, while the DSV Crs are more like divers in risk-taking behavior. The implications of this research to DSV mission effectiveness are discussed.

Adult↗