Probabilistic modelling of CO2 corrosion laboratory data using neural networks

The present paper addresses two major concerns that were identified when developing neural network based prediction models and which can limit their wider applicability in the industry. The first problem is that it appears neural network models are not readily available to a corrosion engineer. Therefore the first part of this paper describes a neural network model of CO2 corrosion which was created using a standard commercial software package and simple modelling strategies. It was found that such a model was able to capture practically all of the trends noticed in the experimental data with acceptable accuracy. This exercise has proven that a corrosion engineer could readily develop a neural network model such as the one described below for any problem at hand, given that sufficient experimental data exist. This applies even in the cases when the understanding of the underlying processes is poor. The second problem arises from cases when all the required inputs for a model are not known or can be estimated with a limited degree of accuracy. It seems advantageous to have models that can take as input a range rather than a single value. One such model, based on the so-called Monte Carlo approach, is presented. A number of comparisons are shown which have illustrated how a corrosion engineer might use this approach to rapidly test the sensitivity of a model to the uncertainities associated with the input parameters. (C) 2001 Elsevier Science Ltd. All rights reserved.

A randomized controlled trial assessing the health economics of realtime teledermatology compared with conventional care: an urban versus rural perspective

A randomized controlled trial was carried out to measure the cost-effectiveness of realtime teledermatology compared with conventional outpatient dermatology care for patients from urban and rural areas. One urban and one rural health centre were linked to a regional hospital in Northern Ireland by ISDN at 128 kbit/s. Over two years, 274 patients required a hospital outpatient dermatology referral -126 patients (46%) were randomized to a telemedicine consultation and 148 (54%) to a conventional hospital outpatient consultation. Of those seen by telemedicine, 61% were registered with an urban practice, compared with 71% of those seen conventionally. The clinical outcomes of the two types of consultation were similar - almost half the patients were managed after a single consultation with the dermatologist. The observed marginal cost per patient of the initial realtime teledermatology consultation was f52.85 for those in urban areas and f59.93 per patient for those from rural areas. The observed marginal cost of the initial conventional consultation was f47.13 for urban patients and f48.77 for rural patients. The total observed costs of teledermatology were higher than the costs of conventional care in both urban and rural areas, mainly because of the fixed equipment costs. Sensitivity analysis using a real-world scenario showed that in urban areas the average costs of the telemedicine and conventional consultations were about equal, while in rural areas the average cost of the telemedicine consultation was less than that of the conventional consultation.

Mental health telemedicine programmes in Australia

A national survey of mental health telemedicine programmes was conducted and data collected on their catchment areas, organizational structure, equipment, clinical and non-clinical activity, and use by populations who traditionally have been poorly served by mental health services in Australia. Of 25 programmes surveyed, information was obtained for 23. Sixteen programmes had dealt with a total of 526 clients during the preceding three months. Of these, 397 (75%) were resident in rural or remote locations at the time of consultation. Thirty-seven (7%) were Aboriginals or Torres Strait Islanders. Only 19 (4%) were migrants from non-English-speaking backgrounds. The programmes provided both direct clinical and secondary support services. Overall, the number of videoconferencing sessions devoted to clinical activity was low, the average being 123 sessions of direct clinical care per programme per year. Videoconferencing was also used for professional education, peer support., professional supervision, administration and linking families. The results of the study suggest that telehealth can increase access to mental health services for people in rural and remote areas, particularly those who have hitherto been poorly served by mental health services in Australia.

Videoconferencing in the Queensland health service

Videoconferencing was introduced in the Queensland health service in 1995. By the end of 1999, there were more than 150 videoconferencing units in health facilities around the state. Six audits of videoconferencing usage were conducted using similar methodology at six-month intervals from November 1997 to May 2000. Between November 1997 and November 1999, the number of calls more than doubled, from 566 to 1378. Hours of usage almost trebled, from 671 to 1724. The average duration of calls remained similar, at about I h 12 min. The proportion of calls involving more than two sites (multipoint videoconferences) increased from 44% to 65%. The majority of the activity was for education (including training). Videoconferencing was also used for administration and clinical care. Mental health staff were the heaviest users, but use by health professionals from other specialty areas increased during the study period. The Queensland health service has realized a number of important benefits from telehealth.

Health and physical education in middle schooling

The middle years of schooling are receiving increased attention. This paper gives some background to 'middle schooling' and begin discussion if physical education is to be involved in the shift that an increasing number of schools are attempting to make in order to enhance student learning. It addresses findings, innovations and changes to the field of physical education. A set of questions are posed about the relationship between the middle years of schooling, health and physical education.

Why farmers continue to use pesticides despite environmental, health and sustainability costs

Use of chemical inputs such as pesticides has increased agricultural production and productivity. However, negative externalities from such use have increased too. These externalities include damage to agricultural land, fisheries, fauna and flora. Another major externality is the unintentional destruction of beneficial predators of pests thereby increasing the virulence of many species of agricultural pests. Furthermore, increased mortality and morbidity of humans due to exposure to pesticides are recorded especially in developing countries. The costs from these externalities are large and affect farmers' returns. However, despite these high costs, farmers continue to use pesticides and in most countries in increasing quantities. In this paper, we examine this paradox and show why farmers continue to use pesticides despite the increasing costs. We also emphasize 'lock-in' aspects of pesticide use. (C) 2001 Elsevier Science B.V. All rights reserved.