No abstract

The effective medical management of a suspected acute radiation overexposure incident necessitates recording dynamic medical data, measuring appropriate radiation bioassays, and estimating dose from dosimeters and radioactivity assessments in order to provide diagnostic information to the treating physician and a dose assessment for personnel radiation protection records. The accepted generic multiparameter and early-response approach includes measuring radioactivity and monitoring the exposed individual; observing and recording prodromal signs/symptoms and erythema; obtaining complete blood counts with white blood cell differential; sampling blood for the chromosome-aberration cytogenetic bioassay using the "gold standard" dicentric assay (translocation assay for long times after exposure) for dose assessment; bioassay sampling, if appropriate, to determine radioactivity contamination; and using other available dosimetry approaches. In the event of a radiological mass-casualty incident, current national resources need to be enhanced to provide suitable dose assessment and medical triage and diagnoses. This capability should be broadly based and include stockpiling reagents and devices; establishing deployable (i.e., hematology and biodosimetry) laboratories and reference (i.e., cytogenetic biodosimetry, radiation bioassay) laboratories; networking qualified reference radioactivity-counting bioassay laboratories, cytogenetic biodosimetry, and deployable hematology laboratories with the medical responder community and national radiation protection program; and researching efforts to identify novel radiation biomarkers and develop applied biological dosimetry assays monitored with clinical, deployable, and hand-held analytical systems. These research and applied science efforts should ultimately contribute towards approved, regulated biodosimetry devices or diagnostic tests integrated into a national radioprotection program.

Six healthy young men and eight early middle-aged men were isolated from environmental time cues for 15 days. For the first 6-7 days (one or two nights adaptation, four nights baseline), their sleep and meals were scheduled to approximate their habitual patterns. Their daily routines were then shifted 6 hours earlier by terminating the sixth or seventh sleep episode 6 hours early. The new schedules were followed for the next 8 or 9 days. Important age-related differences in adjustment to this single 6-hour schedule shift were found. For the first 4-day interval after the shift, middle-aged subjects had larger increases of waking time during the sleep period and earlier termination of sleep than young subjects. They also reported larger decreases in alertness and well-being and larger increases in sleepiness, weariness and effort required to perform daily functions. The rate of adjustment of the circadian core temperature rhythm to the new schedule did not differ between groups. These results suggest that the symptoms reported by the middle-aged subjects may be due mainly to difficulty maintaining sleep at early times of the circadian day. The compensatory response to sleep deprivation may also be less robust in middle-aged individuals traveling eastbound.

No abstract

Previous studies of the effects of television viewing on mental abilities have shown mixed results, but most suffered from one or more of the following shortcomings: a small or otherwise unrepresentative sample, a cross-sectional rather than longitudinal approach, and a failure to consider intervening variables between television viewing and cognitive skills. This study was designed to overcome these deficiencies by using nationally representative data from the National Health Examination Cycle 2 and Cycle 3 Surveys. These surveys included 1,745 children who were studied both when 6 to 11 years old (between July, 1963, and December, 1965) and about four years later when 12 to 17 years old (between March, 1966, and March, 1970). Simple analysis at just one time-point reveals substantial relationships between the amount of television viewing and depressed IQ and Wide Range Achievement Test (Reading and Arithmetic) scores of adolescents. When longitudinal controls are added, however, these relationships become statistically insignificant and substantively unimportant. Although these data are 20 years old, they indicate no significant causal relationship between the amount of television viewed and the mental aptitude and achievement test scores of adolescents, thus supporting and extending Gaddy's (1986) recent longitudinal study of a national sample of youth.