Prediction of driving safety in individuals with homonymous hemianopia and quadrantanopia from clinical neuro-imaging

BACKGROUND: The objective of this study was to determine whether it is possible to predict driving safety in individuals with homonymous hemianopia or quadrantanopia based upon a clinical review of neuro-images that are routinely available in clinical practice. METHODS: Two experienced neuro-ophthalmologists viewed a summary report of the CT/MRI scans of 16 participants with homonymous hemianopic or quadrantanopic field defects which provided information regarding the site and extent of the lesion and made predictions regarding whether they would be safe/unsafe to drive. Driving safety was defined using two independent measures: (1) The potential for safe driving was defined based upon whether the participant was rated as having the potential for safe driving, determined through a standardized on-road driving assessment by a certified driving rehabilitation specialist conducted just prior and (2) state recorded motor vehicle crashes (all crashes and at-fault). Driving safety was independently defined at the time of the study by state recorded motor vehicle crashes (all crashes and at-fault) recorded over the previous 5 years, as well as whether the participant was rated as having the potential for safe driving, determined through a standardized on-road driving assessment by a certified driving rehabilitation specialist. RESULTS: The ability to predict driving safety was highly variable regardless of the driving outcome measure, ranging from 31% to 63% (kappa levels ranged from -0.29 to 0.04). The level of agreement between the neuro-ophthalmologists was also only fair (kappa =0.28). CONCLUSIONS: The findings suggest that clinical evaluation of summary reports currently available neuro-images by neuro-ophthalmologists is not predictive of driving safety. Future research should be directed at identifying and/or developing alternative tests or strategies to better enable clinicians to make these predictions.

Useful field of view test

A test of the useful field of view was introduced more than two decades ago and was designed to reflect the visual difficulties that older adults experience with everyday tasks. Importantly, the useful field of view is one of the most extensively researched and promising predictor tests for a range of driving outcomes measures, including driving ability and crash risk, as well as other everyday tasks. Currently available commercial versions of the test can be administered using personal computers and measure speed of visual processing speed for rapid detection and localization of targets under conditions of divided visual attention and in the presence and absence of visual clutter. The test is believed to assess higher order cognitive abilities, but performance also relies on visual sensory function since targets must be visible in order to be attended to. The format of the useful field of view test has been modified over the years; the original version estimated the spatial extent of useful field of view, while the latest versions measures visual processing speed. While deficits in the useful field of view are associated with functional impairments in everyday activities in older adults, there is also emerging evidence from several research groups that improvements in visual processing speed can be achieved through training. These improvements have been shown to reduce crash risk, and have a positive impact on health and functional well being, with the potential to increase the mobility and hence independence of older adults.

Validation of an instrument to measure governance and performance on collaborative infrastructure projects

Collaborative infrastructure projects use hybrid formal and informal governance structures to manage transactions. Based on previous desk-top research, the authors identified the key mechanisms underlying project governance, and posited the performance implications of the governance (Chen et al. 2012). The current paper extends that qualitative research by testing the veracity of those findings using data from 320 Australian construction organisations. The results provide, for the first time, reliable and valid scales to measure governance and performance of collaborative projects, and the relationship between them. The results confirm seven of seven hypothesised governance mechanisms; 30 of 43 hypothesised underlying actions; eight of eight hypothesised key performance indicators; and the dual importance of formal and informal governance. A startling finding of the study was that the implementation intensity of informal mechanisms (non-contractual conditions) is a greater predictor of project performance variance than that of formal mechanisms (contractual conditions). Further, contractual conditions do not directly impact project performance; instead their impact is mediated by the non-contractual features of a project. Obligations established under the contract are not sufficient to optimise project performance.

Review of the fire performance of LSF walls

Load bearing LSF walls are commonly made of cold-formed steel frames, gypsum plasterboards and insulation, and their fire performance is an important aspect of design. Many experimental and numerical studies have been conducted on the fire performance of LSF walls at the Queensland University of Technology (QUT). These studies have shown that increasing the number or thickness or quality of gypsum plasterboards has improved the fire resistance ratings (FRR) of LSF walls while the use of cavity insulation has reduced their FRR. Therefore new LSF wall systems with external insulation sandwiched between two layers of plasterboards were proposed, which provided higher FRR than cavity insulated walls. There are also other parameters that can improve the fire performance of LSF walls such as the steel type, stud geometry and depth, type of screw fasteners used, joints in the plasterboard and the plasterboard fall off time. This paper presents a review of the fire performance of LSF walls as a function of these parameters based on our research at QUT. Their effects on both the thermal and structural performance of LSF walls are discussed in detail and suitable improvements are recommended, for example, improved plasterboard joint types.

Experimental study on the fire performance of superior LSF wall systems

Load bearing Light Gauge Steel Frame (LSF) walls are commonly made of conventional lipped channel sections and gypsum plasterboards. Recently, innovative steel sections such as hollow flange channel sections have been proposed as studs in LSF wall frames with a view to improve their fire resistance ratings. A series of full scale fire tests was then undertaken to investigate the fire performance of the new LSF wall systems under standard fire conditions. Test wall frames made of hollow flange section studs were lined with fire resistant gypsum plasterboards on both sides, and were subjected to increasing temperatures as given by the standard fire curve on one side. Both uninsulated and cavity insulated walls were tested with varying load ratios from 0.2 to 0.6. This paper presents the details of this experimental study on the fire performance of LSF walls and the results. Test results showed that the walls made of the new hollow flange channel section studs have a superior fire performance in comparison to that of lipped channel section stud walls. They also showed that the fire performance of cavity insulated walls was inferior to that of uninsulated walls. The reasons for this fire behaviour are described in this paper.