A new study reveals that the sleep patterns previously thought exclusive to mammals and birds - REM and slow-wave sleep patterns - are also found in reptiles. The results shake up our understanding of the evolution of sleep. Amniotes are a group of tetrapod vertebrates comprising reptiles, birds and mammals. Because slow-wave sleep (SWS) and rapid eye movement sleep (REMS) are thought to be exclusive to mammals and birds, it's believed that these sleep states evolved twice after mammals and birds diverged from reptiles. However, results by Mark Shein-Idelson et al. now reveal SWS and REM sleep patterns in the Australian bearded dragon, Pogona vitticeps, suggesting that the sleep states may have evolved in a common ancestor of all amniotes, more than 300 million years ago.

Metal on metal hip replacements implanted since 2006 are more prone to failure and the need for further surgery, finds research looking at revision rates at one hospital trust for the DePuy Pinnacle device, and published in the online journal BMJ Open.

A higher rate of manufacturing issues since 2006, with more than a third of hips manufactured outside the stated specifications, may be to blame, suggest the researchers.

They looked specifically at the long term performance of the 36 mm Pinnacle metal on metal hip--the most commonly implanted metal hip in the world--in a bid to uncover the risk factors associated with early failure and the need for further surgery.

Studying the way that solitary hunters such as tigers, bears or sea turtles chase down their prey turns out to be very useful in understanding the interaction between individual white blood cells and colonies of bacteria. Reporting their results in the Journal of Physics A: Mathematical and Theoretical, researchers in Europe have created a numerical model that explores this behaviour in more detail.

Using mathematical expressions, the group can examine the dynamics of a single predator hunting a herd of prey. The routine splits the hunter's motion into a diffusive part and a ballistic part, which represent the search for prey and then the direct chase that follows.

Researchers have found that long-term exposure to environmental pollutants was associated with increased risk of mortality for many types of cancer in an elderly Hong Kong population.

The study between the University of Birmingham and University of Hong Kong, published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, adds to growing concern around the health risks of prolonged exposure to ambient fine particulate matter.

How does the image-recognition technology in a self-driving car respond to a blurred shape suddenly appearing on the road? Researchers from KU Leuven, Belgium, have shown that machines can learn to respond to unfamiliar objects like human beings would.

Imagine heading home in your self-driving car. The rain is falling in torrents and visibility is poor. All of a sudden, a blurred shape appears on the road. What would you want the car to do? Should it hit the brakes, at the risk of causing the cars behind you to crash? Or should it just keep driving?

COLUMBUS, Ohio - Getting more nutritious meals on the tables of low-income Americans could depend on the hours the stores in their neighborhoods keep.

Stores likely to sell fresh produce aren't open as long in areas with more socioeconomic struggles, and that problem is more pronounced in neighborhoods where many African Americans live, new research from The Ohio State University has found.

In affluent neighborhoods, 24-7 access to a wide array of foods is far more common.

"Let's say you're stringing together a few jobs and you get off work at 10 and your market closes at 8. It's a big problem," said researcher Jill Clark, an assistant professor in Ohio State's John Glenn College of Public Affairs.