Older individuals have increased oro-nasal breathing during sleep.

Breathing route during sleep has been studied very little, however, it has potential importance in the pathophysiology of sleep disordered breathing. Using overnight polysomnography, with separate nasal and oral thermocouple probes, data were obtained from 41 subjects (snorers and nonsnorers; 25 male and 16 female; aged 20-66 yrs). Awake, upright, inspiratory nasal resistance (Rn) was measured using posterior rhinomanometry. Each 30-s sleep epoch (not affected by apnoeas/hypopnoeas) was scored for presence of nasal and/or oral breathing. Overnight, seven subjects breathed nasally, one subject oro-nasally and the remainder switched between nasal and oro-nasal breathing. Oral-only breathing rarely occurred. Nasal breathing epochs were 55.79 (69.78) per cent of total sleep epochs (%TSE; median (interquartile range)), a value not significantly different to that for oro-nasal (TSE: 44.21 (68.66)%). Oro-nasal breathing was not related to snoring, sleep stage, posture, body mass index, height, weight, Rn (2.19 (1.77) cm H2O x L(-1) x sec(-1)) or sex, but was positively associated with age. Subjects > or = 40 yrs were approximately six times more likely than younger subjects to spend >50% of sleep epochs utilising oro-nasal breathing. Ageing is associated with an increasing occurrence of oro-nasal breathing during sleep.

Emergency arrangements for CEGB nuclear power station : Changes introduced following the accident at three Mile Island

Comprehensive emergency schemes have been in operation at Central Electricity Generating Board nuclear power stations since 1961. Over the years these schemes have been modified and improved in the light of experience gained during exercises and as a result of scientific research and technological development. Following the accident to Unit 2 reactor at Three Mile Island nuclear power plant in the USA on 28 March 1979 a majo review of CEGB emergency schemes was undertaken. The review indicated certain areas where revisions to existing CEGB emergency schemes should be considered. These areas were: managerial resonsabilities, public relations and the news media, liaison with external organization, telecommunications and population dose assessments. CEGB emergency schemes have now been revised to accommodale the revision proposals and the paper describes the principal changes that have been introduced. These are: (1) The establishment of an Operational Support Centre for each nuclear power station, where a senior management team can co-ordinate all the off-site aspect of an emergency including environmental surveys. An Operational Support Centre (OSC) provides a focal point liaison between the CEGB, the emergency services and government departments and agencies having responsabilities in an emergency. Accommodation is provided for representatives of all these outside organizations. Secure telephone, telex and facsimile transmission facilities are provided at each OSC. (2) The establishment of Press Briefing Centers, in conjuction with Operational Support Centers, where press conferences can be held and where telephone facilities will be provided for reporters. Authoritative press statements will be made at the Press Briefing Centres by senior CEGB managers and spokesmen for external organizations. (3) The installation of fixed gamma monitors around the perimeter of each power station site to provide a time profile of any release of airborne radioactivity, the location or thermoluminescence dosimeters and electronic dosimeters outside each station site and the establishment of Emergency Dose Assessment Servide al CEGB Berkeley Nuclear Laboratories. The paper concludes by reporting experience gained during exercises following the introduction of Operational Support and Press Briefing Centres. (AU)