Evaluating change in professional behaviour: issues in design and analysis

Implementing the findings of research to change the behaviour of health care professionals has become an increasingly prominent issue. However, designing valid studies to evaluate different methods of achieving changes requires considerable care and there are a number of pitfalls evident from published previous work. The various steps in the development of an implementation method and issues arising are explored in this text. Aspects include conceptualisation, essential background work, a structured development process, the relative merits of randomised and non-equivalent group designs, the unit of analysis, the role of multi-level models, block designs, economic analysis, and the content or message to be disseminated. An ongoing, large, randomised trial of educational outreach visits by trained pharmacists is used to illustrate some of the issues.behavioural change, implementation methods, economic evaluation, design of trials

Perceptions of seagrass ecosystem health and potential indicators for monitoring

A range of seagrass characteristics were assessed for potential use as indicators of ecosystem health. Shoot density, shoot width, maximum shoot length, above and below ground biomass, percentage canopy cover, leaf area index, leaf extension rate, meadow productivity, epiphyte biomass, epiphyte species richness, percentage of calcium carbonate in epiphytic material and percentage of nitrogen in leaf tissue were all measured in “healthy~ and unhealthy Posidonia augustifolia meadows in Cockburn and Warnbro Sounds, from June through to August 1998. A questionnaire was used to determine which meadows researchers and managers in the seagrass ecology field in Perth perceived to be healthy or unhealthy. Seagrass meadows were then compared according to several indicator criteria, primarily whether they showed any differences between perceived healthy and unhealthy meadows. A second questionnaire was undertaken to obtain and understanding of which variables researchers and managers felt were important in formulating a perception of seagrass ecosystems health. These perceptions were then compared with the measurable data for each variable. This was to provide an indication of whether the decisions made and influenced by these people on the management of seagrass ecosystems are based on comprehensive and accurate information. The sites perceived to be healthy, corresponded with previous data on the region which indicated they were Jess nutrient enriched, had higher light attenuation and less phytoplankton in the water column than those perceived to be unhealthy. There were only two variables to show significant differences between the perceived healthy and unhealthy sites, maximum shoot length and above ground biomass. These two variables and only two others, shoot density and percentage canopy cover adhered to at least four of the six indicator criteria, with maximum shoot length adhering to all six. These results differed to the perceptions of researchers and managers, with the exception of shoot density and percentage canopy cover. Epiphyte composition and epiphyte biomass were the other two variables considered to be important in formulating a perception of the health of a seagrass meadow. Information from this study suggests that management of Posidonia angustifolia meadows should centre around the measurement of maximum shoot length and above ground biomass. The vastly different results obtained from the questionnaire suggested that current seagrass monitoring in Western Australia may be in adequate. Further study on monitoring Posidonia angustifolia and Western Australia\u27s other dominant seagrass species is thus recommended to ensure management decisions are based on data that arc as close to reality as possible

Euler Found the First Binary Digit Extraction Formula for π in 1779

In 1779 Euler discovered two formulas for π which can be used to calculate any binary digit of π without calculating the previous digits. Up until now it was believed that the first formula with the correct properties (known as a BBP-type formula) for this calculation was published by Bailey, Borwein and Plouffe in 1997

The Case for Medium-Sized Regional Data Centres

Cloud computing is widely associated with majorcapital investment in mega data centres, housing expensive bladeservers and storage area networks. In this paper we argue that amodular approach to building local or regional data centres usingcommodity hardware and open source hardware can produce acost effective solution that better addresses the goals of cloudcomputing, and provides a scalable architecture that meets theservice requirements of a high quality data centre.In support of this goal, we provide data that supports threeresearch hypotheses:1. that central processor unit (CPU) resources are notnormally limiting;2. that disk I/O transactions (TPS) are more oftenlimiting, but this can be mitigated by maximizing theTPS-CPU ratio;3. that customer CPU loads are generally static andsmall.Our results indicate that the modular, commodity hardwarebased architecture is near optimal. This is a very significantresult, as it opens the door to alternative business models for theprovision of data centres that significantly reduce the need formajor up-front capital investment

Lifetime performance characteristics of screen-printed potentiometric Ag/AgCl chloride sensors

Ag/AgCl chloride sensors were fabricated using thick-film technology. A number of different formulations were prepared and chloride responses were investigated over time. Near Nernstian, identical responses were observed over the first 160 days with an average chloride sensitivity of -51.8 ± 0.4 mV per decade change in chloride concentration (pCl), irrespective of paste formulation. After 6- months continuous immersion in tap water, pastes formulated with a glass binder began to exhibit a loss in sensitivity whilst those formulated from a commercial thickfilm dielectric paste remained functional for the best part of a year. The difference is attributed to the inclusion of proprietary additives in the commercial paste aiding adhesion and minimising AgCl leaching

Screen-printed platinum electrodes for measuring crevice corrosion: Nickel aluminium bronze as an example

Screen-printed platinum electrodes were used to monitor crevice corrosion processes. The electrodes, printed on an inert alumina substrate, formed the bottom of an artificial crevice when mechanically clamped to a rectangular block of nickel-aluminium bronze (NAB). Cyclic differential pulse voltammetry was used to detect corrosion products over time whilst the assembly was immersed in a 3.5% by weight aqueous solution of sodium chloride. Cupric (Cu2+), ferric (Fe3+) and ferrous (Fe2+) ions were detected with evolution profiles indicative of selective phase corrosion

Screen-printed platinum electrodes for the detection of cupric and ferric ions in high chloride backgrounds

Screen-printed platinum electrodes developed for use in corrosion monitoring applications have been used to detect cupric and ferric ions both individually and as mixtures in a background of 3.5% by weight sodium chloride and in the presence of dissolved oxygen. In single species detection linear responses for the Fe3+/Fe2+ couple were observed over the concentration range 0.3 to 100mM. By contrast, the small size of the working electrode caused a current limiting response for cupric ions over the same concentration range. In mixtures of these ions, the sensors show good differentiation and are able to separate the individual metal ion responses