Cardiovascular surveys : manual of operations

Cardiovascular disease (CVD) is the leading cause of death and hospitalization in both men and women in nearly all countries of Europe. The most frequent forms of CVD are those of an atherosclerotic origin, mainly ischaemic heart disease, stroke and heart failure. The magnitude of the problem contrasts with the usual paucity and poor quality of data available on incidence and prevalence of CVD, except for few rigorous but limited studies.

The objectives of the health interview and health examination surveys (HIS/HES) are to evaluate the frequency and the distribution of the disease, to evaluate trends and treatment effectiveness, to estimate risk factors distribution and prevalence of high risk conditions and to monitor prevention programmes.

According to the EUROCISS project (EUROpean Cardiovascular Surveillance Set) recommendations, surveys are aimed at describing the prevalence of the following CVD conditions: myocardial infarction, heart failure, angina pectoris, peripheral arterial disease, stroke, and ischaemic heart disease.

HIS and HES were developed to supplement information collected from routine databases and population-based registers to implement consistent public health policies. HIS can be repeated periodically in a new sample of the population, or can follow up over time the population recruited at baseline. Procedures and methods to collect information from participants include self-administered questionnaires, direct interviewer-administered questions and telephone interviews. A minimum set of questions to be administered every year, along with a longer, more detailed module to be administered periodically are recommended to evaluate CVD prevalence. The addition of HES provides more detailed and objective information that can be used to improve estimates regarding prevalence of both risk factors and disease status.

The selection of more specialized CVD-specific tests will depend on the objective the survey is designed to achieve, the assumed response rate and the cost and time considerations. For HES on CVD the minimum required is to perform the following measurements: height, weight, blood pressure, waist circumference, total and high density lipoprotein-cholesterol and glucose assay in a nonfasting blood sample. The next appropriate step would be to perform an electrocardiogram. High costs usually make HES difficult to carry out.

Standardization of measurements, training of personnel and quality control are essential to assure reliable data. A high response rate is extremely important, as nonrespondents tend to have different health characteristics from the rest of the sample and their omission therefore results in bias.

This manual of operations is intended for health professionals and policy makers and provides a standardized and simple model for the implementation of a CVD survey.

Modelling of birds and locust-control operations in Eastern Australia

Locust outbreaks provide an abundant, but unpredictable food source for many native species in Australia. For economic reasons, locust control is unavoidable and can affect a considerable area in Eastern Australia. Depending on the pesticide applied, locust control operations may affect birds in treated areas, either directly through intoxication of the predator, or indirectly, through elimination of its prey. As a preliminary step in identifying the potential impact of these operations on native species, the co-occurrence of birds and locust control operations was assessed using GIS mapping techniques. Data from the Birds of Australia New Atlas provided information about species' distribution between latitudes 17 and 37 degree S, and longitudes 136 and 152 degree E. Of the 834 species present in this region, 292 were chosen on the basis of their geographical distribution and occurrence west of the Great Dividing Range. Sightings for each species were mapped using reporting rates and number of observations per half-degree grid cells. Birds were categorised by habitat, distribution, movement and feeding habits and those species reported to consume Orthopterans were noted. APLC locust survey (1987–2000) and spraying data (1977–2002) were analysed and overlapped with soil and vegetation maps obtained from Geoscience Australia and Environment Australia to find significant hotspots for locust occurrence. These maps were then overlayed with bird distributions to identify the species most likely to be in areas of locust presence and spraying operations.

"Minerals", "petroleum" and "operations" in the Mineral and Petroleum Resources Development Act 28 of 2002 : a geologist as devil's advocate for a change? "

This article examines the meaning of "minerals", petroleum, "operations" and activities in relation to such substances to determine the ambit of the application of the Minerals and Petroleum Resources Development Act 28 of 2002, the type of rights necessary for such operations and activities and the ambit of these rights. The examination of the meaning of these concepts takes place with reference to prior definitions in statutes and also from a natural science and geology perspective. An attempt is made to show that the legal definitions do no always correspond with the geological meanings and the meanings on the ground. It is questioned whether in recent legislation why more reliance is not placed on input from geologists in the field.

Exposure to fumes and gases during welding operations

The exposure to fumes and gases is one of the hazards associated with welding operations. Apart from research conducted on the mechanism of fume and gas formation and the relationship between fume formation rates and common welding parameters, little is known about the exposure process during welding. This research project aimed to identify the factors that influence exposure, develop an understanding of their role in the exposure process and through this understanding formulate strategies for the effective control of exposure during welding. To address these aims a literature review and an experimental program was conducted The literature review surveyed epidemiological, toxicological and exposure data. The experimental program involved three approaches, the first, an evaluation of the factors that influence exposure by assessing a metal inert gas/mild steel welding process in a workshop setting. The second approach involved the study of exposure in a controlled environment provided by a wind tunnel and simulated welding process. The final approach was to investigate workplace conditions through an assessment of exposure and control strategies in industry. The exposure to fumes and gases during welding is highly variable and frequently in excess of the health based exposure standards. Exposure is influenced by a number of a factors including the welding process, base material, arc time, electrode, arc current, arc voltage, arc length, electrode polarity, shield gas, wire-to-metal-work distance (metal inert gas), metal transfer mode, intensity of the UV radiation (ozone), the frequency of arc ignitions (ozone), thermal buoyancy generated by the arc process, ventilation (natural and mechanical), the welding environment, the position of the welder, the welders stance, helmet type, and helmet position. Exposure occurs as a result of three processes: the formation of contaminants at or around the arc region; their transport from the arc region, as influenced by the entry and thermal expansion of shield gases, the vigorous production of contaminants, thermal air currents produced by the heat of the arc process, and ventilation; and finally the entry of contaminants into the breathing zone of the welder, as influenced by the position of the welder, the welders stance, helmet type, and the helmet position. The control of exposure during welding can be achieved by several means: through the selection of welding parameters that generate low contaminant formation rates; through the limitation of arc time; and by isolating the breathing zone of the welder from the contaminant plume through the use of ventilation, welder position or the welding helmet as a physical barrier. Effective control is achieved by careful examination of the workplace, the selection of the most appropriate control option, and motivation of the workforce.

Modelling and optimising operations of a plant using JIT philosophy

An Australian automotive component company plans to assemble and deliver seats to a car manufacturer on a "just-in-time" basis at its new plant. The research objective was to model seat assembly operations and apply Toyota goal chasing algorithm and user defined algorithm to balance workload among all the assembly workstations and areas.

Mathematical modelling of the crankshaft pin grinding process

Novel mathematical models to predict crankshaft pin grinding forces, out-of-roundness and thermal damage were developed as part of this thesis. The models were validated at a local automotive manufacturer's plant. The outcomes of this research have resulted in reduced scrap and warranty costs, improved manufacturing process quality and reduced lead times.