Social Aspects of Communication

Communication services arise as a response to social needs, including personal interaction, collective behavior, learning and socialization, and organized communication. These are met by an increasingly varied range of biosocial and man-machine processes. By the year 2000, it is possible that 20 or more such processes will be in widespread use. The planning and provision of services in response to demand involves a complex set of relationships between industrial production, occupational groups, governmental and nongovernmental service industries and regulatory bodies, primary social groups, and formal institutions. Models of these relationships may be called sociotechnical systems. They are particularly necessary to avoid crude technological determinism, which is present in much writing on the future of telecommunications and overstates the ability of mechanical devices to deal with social issues. The capacity of telecommunications to replace face-to-face interaction, to substitute for transportation, or to revolutionize education is not borne out by the evidence. Research on the social role of the telephone is now producing firmer evidence on which to base policy decisions.     

Urinary 6-sulfatoxymelatonin cycle-to-cycle variability

For either clinical or research purposes, the timing of the nocturnal onset in production of the urinary melatonin metabolite 6-sulfatoxymelatonin (UaMT6s-onset), has been proposed as a reliable and robust marker of circadian phase. However, given that most circadian rhythms show cycle-to-cycle variability, the statistical reliability of phase estimates obtained from a single study using UaMT6s-onset remains to be determined. Following 2 weeks of sleep diary and wrist actigraphy, 15 young, healthy good sleepers participated in four UaMT6s sampling sessions spaced 1 day apart. During the sampling sessions subjects remained indoors under low light conditions and hourly urine samples were collected from 19:00 to 02:00 h. Samples were subsequently assayed for UaMT6s using standard radioimmunographic techniques. UaMT6s-onset was determined by the time at which melatonin production exceeded the average of three proceeding trials by 100%. Sleep onset times were derived from sleep diary and actigraphic measures taken before the melatonin collection nights. We found that there was no significant variation between nights in group mean UaMT6s-onset times, and intraindividual variability was small. In addition, UaMT6s-onset times were highly and significantly correlated between nights (grand mean r = 0.804). Our results suggest that within 95% confidence interval limits, individual UaMT6s-onset estimates obtained from a single night UaMT6s-onset study can be used to predict subsequent UaMT6s-onset times within +/- 97 min. A close temporal relationship was also found between the timing of UaMT6s-onset and sleep onset. Overall, our results suggest that under entrained conditions single-session UaMT6s-onset studies can provide reliable individual UaMT6s-onset phase estimates and that the protocol described in this study is a practical and noninvasive methodology.