Unlicensed driving among California high school seniors

The driving behaviors and characteristics of unlicensed teenage drivers have been little explored. For this study of behaviors of unlicensed California teen drivers, 2,144 high school seniors at 13 school sites in California completed a written survey. Unlicensed driving was ascertained by combining survey questions about licensing and driving. Data were analyzed to examine characteristics of unlicensed drivers compared with licensed drivers, and to examine risk behaviors among the unlicensed drivers. A total of 12.4 percent (n = 265) of students reported driving a motor vehicle without a driver’s license or permit, while two-thirds of surveyed students had either a license or a permit, and the remainder did not drive. Unlicensed drivers were primarily male (56 percent) and Latino (67 percent); unlicensed drivers were more likely than others to attend a school with a lower-income population. Licensed and unlicensed drivers reported similar rates of driving after alcohol or other drug use. Licensed drivers were more likely than unlicensed drivers to report having been in a crash, but this difference was no longer significant after adjustment for risk behaviors. Unlicensed driving was fairly common in this sample, but did not appear to represent an excess risk relative to licensed drivers

Dietary Modulation of Drosophila Sleep-Wake Behaviour

Background A complex relationship exists between diet and sleep but despite its impact on human health, this relationship remains uncharacterized and poorly understood. Drosophila melanogaster is an important model for the study of metabolism and behaviour, however the effect of diet upon Drosophila sleep remains largely unaddressed. Methodology/Principal Findings Using automated behavioural monitoring, a capillary feeding assay and pharmacological treatments, we examined the effect of dietary yeast and sucrose upon Drosophila sleep-wake behaviour for three consecutive days. We found that dietary yeast deconsolidated the sleep-wake behaviour of flies by promoting arousal from sleep in males and shortening periods of locomotor activity in females. We also demonstrate that arousal from nocturnal sleep exhibits a significant ultradian rhythmicity with a periodicity of 85 minutes. Increasing the dietary sucrose concentration from 5% to 35% had no effect on total sucrose ingestion per day nor any affect on arousal, however it did lengthen the time that males and females remained active. Higher dietary sucrose led to reduced total sleep by male but not female flies. Locomotor activity was reduced by feeding flies Metformin, a drug that inhibits oxidative phosphorylation, however Metformin did not affect any aspects of sleep. Conclusions We conclude that arousal from sleep is under ultradian control and regulated in a sex-dependent manner by dietary yeast and that dietary sucrose regulates the length of time that flies sustain periods of wakefulness. These findings highlight Drosophila as an important model with which to understand how diet impacts upon sleep and wakefulness in mammals and humans