OBJECTIVE Recent reports on all-terrain vehicle (ATV) accidents cite high injury and death rates, disproportionately affecting younger riders. We sought to determine whether serious injuries at a level 1 trauma center have increased among older riders. MATERIALS AND METHODS Using the trauma registry, 300 ATV accidents from March 1, 1997 through March 30, 2007 were identified. A total of 250 p...

Self-interest frequently causes individuals engaged in joint enterprises to choose actions that are counterproductive. Free-riders can invade a society of cooperators, causing a tragedy of the commons. Such social dilemmas can be overcome by positive or negative incentives. Even though an incentive-providing institution may protect a cooperative society from invasion by free-riders, it cannot a...

19 Extensive interviews with riders of the Pittsburgh bus system revealed that, as the top 20 priority, riders want to know the current location of buses. Using a universal design 21 methodology, we designed a system, named Tiramisu, to foster a greater sense of community 22 between riders and transit bus service providers. Our design focuses on crowd-sourcing 23 acquisition of information abou...

In an environment in which free-riders are better off than cooperators, social control is required to foster and maintain cooperation. There are two main paths through which social control can be applied: punishment and reputation. Our experiments explore the efficacy of punishment and reputation on cooperation rates, both in isolation and in combination. Using a Public Goods Game, we are inter...

We compared anteroposterior and mediolateral range of motion and velocity of the center of pressure (COP) on the horse's back between riders without disabilities and riders with cerebral palsy. An electronic pressure mat was used to track COP movements beneath the saddle in 4 riders without disabilities and 4 riders with cerebral palsy. Comparisons between rider groups were made using the Mann-...

Social sensing via mobile apps complements physical sensing (e.g., IoT) by substantially extending the horizon we know about our daily life in real time. This paper discusses how we can integrate physical and social sensing to enable better and smarter services, focusing on enriching riders’ experience of using bike sharing services in New York City. We show how we real time collect, process, a...

We propose two schemes for efficient broadcast key establishment that enables a sender to communicate to any subset of the user-base by allowing a small ratio of free-riders. The schemes do not require stateful receivers and one scheme is unconditionally secure. The free-riders are unable to learn from the past whether they might become free-riders for a certain transmission again. We present a...

OBJECTIVE To investigate the use of helmets for cyclists choosing to use BIXI bikes in comparison to personal bike riders in the City of Toronto. DESIGN Cross-sectional study design. SETTING Cyclists were observed in Toronto, Canada. PARTICIPANTS Of the 6732 sample size, 306 cyclists on BIXI bikes and 6426 personal bike riders were observed. OUTCOME MEASURE The outcome of interest was h...

Problem definition: Difficulties in healthcare delivery in developing economies arise from poor road infrastructure of rural communities, where the bulk of the population reside. Although motorcycles are an effective means for delivering healthcare products, governments in developing economies lack expertise in proper maintenances, resulting in frequent vehicle breakdowns. Riders for Health, a ...