A comparison of methods for calculating general practice level socioeconomic deprivation

Background: A measure of the socioeconomic deprivation experienced by the registered patient population of a general practice is of interest because it can be used to explore the association between deprivation and a wide range of other variables measured at practice level. If patient level geographical data are available a population weighted mean area-based deprivation score can be calculated for each practice. In the absence of these data, an area-based deprivation score linked to the practice postcode can be used as an estimate of the socioeconomic deprivation of the practice population. This study explores the correlation between Index of Multiple Deprivation 2004 (IMD) scores linked to general practice postcodes (main surgery address alone and main surgery plus any branch surgeries), practice population weighted mean IMD scores, and practice level mortality (aged 1 to 75 years, all causes) for 38 practices in Rotherham UK. Results: Population weighted deprivation scores correlated with practice postcode based scores (main surgery only, Pearson r = 0.74, 95% CI 0.54 to 0.85; main plus branch surgeries, r = 0.79, 95% CI 0.63 to 0.89). All cause mortality aged 1 to 75 correlated with deprivation (main surgery postcode based measure, r = 0.50, 95% CI 0.22 to 0.71; main plus branch surgery based score, r = 0.55, 95% CI 0.28 to 0.74); population weighted measure, r = 0.66, 95% CI 0.43 to 0.81). Conclusion: Practice postcode linked IMD scores provide a valid proxy for a population weighted measure in the absence of patient level data. However, by using them, the strength of association between mortality and deprivation may be underestimated

A comprehensive WebCT integration system

Murdoch University, in collaboration with industry partners, has developed a sophisticated middleware application (WebCTMan) between WebCT and other corporate systems, such as the Callista student records system, the Concept 1 human resources system and Murdoch’s own authentication system. This presentation will describe the architecture and functionality of this system. The impetus for WebCTMan was to enable Murdoch to change its student records database with minimal impact on our WebCT installation. However, WebCTMan now gives us great flexibility in managing our WebCT installation, enabling us to manage courses across teaching periods, and upgrade easily. This paper describes the context in which this system was built and gives an overview of its architecture. Courses in WebCTMan can have a status of active (where student details are updated nightly), inactive (where all students are orphans), and static (where student accounts are valid but not updated). Tools are available to change this status, and easily activate and deactivate courses. Different versions of courses are maintained for each teaching period, resolving the problem of overlap between semesters, when some students still have deferred examinations after the start of a new semester. In addition to managing students, WebCTMan provides functionality to manage staff and courses. Staff can request courses to be created or cloned from other courses. They can also create their own guest accounts and allocate tutors and markers to courses, and download class lists. Operators can create or rename courses on demand, as well as changing the roles of staff, including primary and secondary designers. A subset of functions is available to helpdesk operators, who can lookup details of both students and staff within the system

Coupled Riccati equations for complex plane constraint

A new Linear Quadratic Gaussian design method is presented which provides prescribed imaginary axis pole placement for optimal control and estimation systems. This procedure contributes another degree of design freedom to flexible spacecraft control. Current design methods which interject modal damping into the system tend to have little affect on modal frequencies, i.e., they predictably shift open plant poles horizontally in the complex plane to form the closed loop controller or estimator pole constellation, but make little provision for vertical (imaginary axis) pole shifts. Imaginary axis shifts which reduce the closed loop model frequencies (the bandwidths) are desirable since they reduce the sensitivity of the system to noise disturbances. The new method drives the closed loop modal frequencies to predictable (specified) levels, frequencies as low as zero rad/sec (real axis pole placement) can be achieved. The design procedure works through rotational and translational destabilizations of the plant, and a coupling of two independently solved algebraic Riccati equations through a structured state weighting matrix. Two new concepts, gain transference and Q equivalency, are introduced and their use shown

Altitude characteristics of selected air quality analyzers

The effects of altitude (pressure) on the operation and sensitivity of various air quality analyzers frequently flown on aircraft were analyzed. Two ozone analyzers were studied at altitudes from 600 to 7500 m and a nitrogen oxides chemiluminescence detector and a sulfur dioxide flame photometric detector were studied at altitudes from 600 to 3000 m. Calibration curves for altitude corrections to the sensitivity of the instruments are presented along with discussion of observed instrument behavior