Indicators specifically designed to detect changes in the seasonality, frequency and duration of medium and high river flows have been developed to monitor river flow regimes. Four primary methods to display and interpret the indicator results have been developed to meet the needs of different target audiences. The variability in annual indicator values is accommodated by comparing the probability distributions of the annual values rather than seeking to identify trends in annual values themselves. Changes in the distribution of indicator values are consistent with those anticipated to arise as a result of climate change. This finding is confirmed by calculating the indicators from example flow data for catchments across England and Wales, which has been perturbed to reflect climate change scenario model outputs.

Objectives: To assess prevalence of HIV and sexually transmitted infections (STIs), risk behaviours, and demographics in male commercial sex workers (CSWs)/prostitutes in Sydney.Methods: Retrospective, cross sectional study with two comparison groups. Demographic, behavioural, and morbidity data were analysed from standardised medical records of patients attending a public STI and HIV service in Sydney between January 1991 and March 1998. Two comparison groups were used: female CSWs and non-CSW working homosexual men who attended over the same time.Results: 94 male CSWs, 1671 female CSWs, and 3541 non-CSW working homosexual men were included. The prevalence of HIV in male CSWs tested (6.5%) was significantly greater than in female CSWs (0.4%, p=0.0001), but less than in non-CSW homosexual men (23.9%, p<0.0001). Genital warts occurred significantly more frequently in male CSWs than in comparison groups. Prevalence of other STIs was similar in all groups. Male CSWs saw significantly fewer clients per week than female CSWs and male and female CSWs used condoms with almost all clients. Male CSWs reported significantly more non-work sexual partners than female CSWs and non-CSW homosexual men and were significantly more likely to have unprotected penetrative sex with their non-work partners than non-CSW homosexual men. Injecting drug use was significantly more frequent in male CSWs than in both comparison groups.Conclusions: Although male CSWs use condoms with clients, they are more likely to practise unsafe sex with non-work partners (especially women) and inject drugs than female CSWs and non-CSW homosexual men. Some men with HIV are working within the commercial sex industry. Targeted health education to encourage safer drug use and safer sex outside work is needed.

A general thermal systems analysis has been conducted for several variations of a notional space based electric laser system with solid state diodes. This laser system can potentially be powered by several power generating concepts such as the solar array/ battery concept, the H2 - O2 turbo generator concept which may be closed cycle or open cycle, the magneto hydro dynamics [MHD] concept or the flywheel concept. Each one of these power generation mechanisms has its own advantages and disadvantages, but the thermal analysis aims to compare these various options on a common pedestal such as system mass, in order to arrive at the most suitable configuration. The notional electric laser system powered by a solar array with rechargeable battery banks was used as the baseline for the various power system options considered in this analysis. Several technological enhancements were incorporated in the analysis for the H2 - O2 system concepts with special emphasis and advocacy of the use of extremely efficient cryogenic super conducting generators and cryogenic power conditioning equipment as these components can be cooled with the cryogenic effluents before they are combusted. The notional systems we have compared for this paper use a 23.5% efficient electric laser (50% electric to optical power diode pump, and a 47% optical to optical high power laser) with 8 MWrf Of Output laser power in most cases. This is an extremely high power level, so we predict the systems to be somewhat massive and on the order of 40 metric tons (MT, 1000 kg) or more. We predict that the H-2-O-2 open cycle system, with propellant for 5 engagements, will be marginally better than the baseline solar concept. For a one-day recharge time, the H-2-O-2 concept recycling all effluents is twice as massive as the baseline solar system. As the recharge time is extended from one day to more than five, the concept that reclaims the effluents begins to appear more attractive.

A computerized analytical program is being developed to help investigate the impact of power system requirements on aircraft performance. The program has an user interface that operates in MS-EXCEL, linking several subsystems analysis programs for execution and data transfer in the power systems analysis. The program presently includes an encoded propulsion engine cycle code, which allows the inspection of power extraction effects on engine performance. To validate the results of the encoded engine program, a study was conducted to investigate the separate effects of shaft power extraction and pneumatic bleed. The selected engine cycle was that for a standard tactical fighter, with a flight condition of varied altitude (sea level to 40,000 ft) and constant Mach Number (0.9). As expected the resultant data showed that the engine performance was more sensitive to pneumatic bleed than to shaft power extraction. The paper’s efficiency comparisons between shaft power and bleed air power helps indicate the higher efficiency for the power system of a more-electric type aircraft. Present efforts on the analytical interface are to incorporate a fuel thermal management analysis capability.