Safety aspects of riding with children: Descriptive analysis of adult riders' self-report

Active transport, including cycling, is promoted as an effective way of increasing children's physical activity and health. Parents can support children's riding by riding with them and it is important to address relevant safety issues. Little is known about parents' experience of safety-relevant aspects of riding with children. Participants in the Safer Cycling Study in New South Wales, Australia, who reported that they had ridden with children in the last 12 months were questioned about how they ride with children, and their experience of safety issues and crashes. Among the 187 respondents who had ridden with children on their bicycle, the most common form of carrier was a rear-mounted seat (48%) followed by a trailer (29%). Many respondents (79%) identified risks specific to riding carrying children, including those linked with specific carrier types and with use of footpaths. Most (92%) indicated that they change their behaviour when carrying a child on their bicycle; for example, riding more slowly, more carefully, and away from roads. Among crashes with a child on the bicycle, most were falls. Among the 345 participants who had ridden to accompany a child on a bicycle, approximately three quarters identified risks specific to accompanying children, such as managing the child's limited skill, awareness and predictability. Ninety-seven percent reported behavioural changes including positioning themselves as a barrier for their child and caution crossing roads. Findings suggest strategies to support parents in riding safely with children.

Near miss experiences of transport and recreational cyclists in New South Wales, Australia. Findings from a prospective cohort study

This paper investigates events in which cyclists perceive a cycling crash is narrowly avoided (henceforth, a near miss). A cohort of 2038 adult transport and recreational cyclists from New South Wales (Australia) provided self-reported prospectively collected data from cycling diaries to allow the calculation of an exposure-based rate of near misses and investigation of near miss circumstances. During 25,971days of cycling, 3437 near misses were reported. For a given time cycling, cyclists who rode mainly for transport (compared with those who rode mainly for recreation), and cyclists with less experience (compared to those with more experience) were more likely to report a near miss; older cyclists (60+ years) were less likely to report a near miss than younger cyclists (25-59 years). Where type of near miss was recorded, 72.0% involved motor vehicles, 10.9% involved pedestrians and 6.9% involved other cyclists. Results indicate some similarities between near misses and crashes reported by this cohort during the same reporting period. A bias toward reporting near misses with motor vehicles was suggested, which likely reflects cyclists' perceptions that crashes involving motor vehicles are particularly serious, and highlights their impact on perceived safety. Given the relative rarity of crashes, and the limited breadth and depth of administrative data, collection of near miss data may contribute to our understanding of cycling safety by increasing the volume and detail of information available for analysis. Addressing the causes of near misses may offer an opportunity to improve both perceived and actual safety for cyclists.

An exposure based study of crash and injury rates in a cohort of transport and recreational cyclists in New South Wales, Australia

This paper examines self-reported prospectively collected data from 2038 adult transport and recreational cyclists from New South Wales (Australia) to determine exposure-based incident crash and injury rates. During 25,971 days of cycling, 198 crashes were reported, comprising approximately equal numbers of falls and collisions. The overall crash rate was 0.290 (95% CI, 0.264-0.319) per 1000km or 6.06 (95% CI, 5.52-6.65) per 1000h of travel. The rate of crashes causing any injury (self-treated, or medically attended without overnight hospital stay) was 0.148 (95% CI, 0.133-0.164) per 1000km or 3.09 (95% CI, 2.79-3.43) per 1000h of travel. The rate of crashes causing a medically attended injury (without overnight hospital stay) was 0.023 (95% CI, 0.020-0.027) per 1000km or 0.49 (95% CI, 0.43-0.56) per 1000h of travel. No injuries requiring an overnight stay in hospital were reported on days meeting the inclusion criteria. After adjustment for exposure in hours, or for the risks associated with different infrastructure utilisation, the rates of crashes and medically attended injuries were found to be greater for females than males, less experienced than more experienced cyclists, and for those who rode mainly for transport rather than mainly for recreation. Comparison of estimated crash and injury rates on different infrastructure types were limited by the small number of events, however findings suggest that the separation of cyclists from motorised traffic is by itself not sufficient to ensure safe cycling.

Characteristics, cycling patterns, and crash and injury experiences at baseline of a cohort of transport and recreational cyclists in New South Wales, Australia

This paper examines self-reported retrospective data for a 12 month period from 2038 adult cyclists from New South Wales (Australia), and compares cyclists according to whether they self-identify as riding mainly for transport or mainly for recreation. Statistically significant differences were found in the demographic characteristics, cycling patterns, and crash experiences between these two groups of cyclists. Transport cyclists tended to be younger, travel more days per week, and within morning and evening peak hours than recreational cyclists; recreational cyclists were more likely to identify fitness as a purpose for cycling. The proportion of cyclists experiencing a crash or crash-related injury in the previous 12 months was similar for transport and recreational cyclists, but there were differences in crash types and location which likely reflect different cycling environments. Heterogeneity within transport and recreational cyclists was also found, based on self-reported riding intensity. An understanding of the different cycling patterns and experiences of various types of cyclists is useful to inform road safety, transport and health promotion policy.

Clustering of gene expression data via normal mixture models

There are two distinct but related clustering problems with microarray data. One problem concerns the clustering of the tissue samples (gene signatures) on the basis of the genes; the other concerns the clustering of the genes on the basis of the tissues (gene profiles). The clusters of tissues so obtained in the first problem can play a useful role in the discovery and understanding of new subclasses of diseases. The clusters of genes obtained in the second problem can be used to search for genetic pathways or groups of genes that might be regulated together. Also, in the first problem, we may wish first to summarize the information in the very large number of genes by clustering them into groups (of hyperspherical shape), which can be represented by some metagenes, such as the group sample means. We can then carry out the clustering of the tissues in terms of these metagenes. We focus here on mixtures of normals to provide a model-based clustering of tissue samples (gene signatures) and of gene profiles.

Fluidics cube for biosensor miniaturization

To create a small, portable, fully automated biosensor, a compact means of fluid handling is required. We designed, manufactured, and tested a "fluidics cube" for such a purpose. This cube, made of thermoplastic, contains reservoirs and channels for liquid samples and reagents and operates without the use of any internal valves or meters; it is a passive fluid circuit that relies on pressure relief vents to control fluid movement. We demonstrate the ability of pressure relief vents to control fluid movement and show how to simply manufacture or modify the cube. Combined with the planar array biosensor developed at the Naval Research Laboratory, it brings us one step closer to realizing our goal of a handheld biosensor capable of analyzing multiple samples for multiple analytes.