16 | NewScientist | 10 August 2013

IF THERE was ever a study not to lose sleep over, it’s this one. People deprived of a good night’s rest are more likely to see changes in brain activity that lead to an increased desire for high-calorie foods.

Matthew Walker at the University of California in Berkeley and colleagues have conducted the first study of brain activity in relation to food among sleep-deprived people. The team

used fMRI to study brain patterns in 23 people first after a night of peaceful sleep and then after a night without sleep.

Sleep deprivation diminished activity in three areas of the brain that help, among other things, to process odour and flavour signals. It also led to more activity in the amygdala, which helps govern the motivation to eat.

After no sleep, the volunteers

Come on crystals, let’s see you jump

THAT’S one giant leap for crystals: some can jump a thousand times their own length under light one-tenth as bright as the sun.

Pance Naumov of New York University in Abu Dhabi noticed the power that light can have on crystals in 2010, when he saw crystals of green fluorescent protein bend to more than 90 degrees under weak illumination. Now he has seen tiny crystals containing cobalt, chlorine and nitrate groups hop under ultraviolet light (Angewandte Chemie, doi.org/f2dkxd).

“It’s fascinating,” Naumov says. “What really impressed me is the magnitude of the response.”

The effect seems to be down to the way light energy causes atoms in the crystal to rearrange themselves, leading to a build-up of strain that is then explosively released. This property could eventually be put to work in microscopic mechanical systems.

Forget doggy paddle – apes prefer breaststroke

DIFFERENT strokes for different folks? Not when it comes to the aquatic ape: the first detailed observations of swimming chimpanzees and orang-utans suggest that they, like us, tend to opt for a form of breaststroke. The findings imply that we may owe our swimming style to our evolutionary past.

Apart from humans, great apes usually avoid deep water for fear of unseen predators that might be lurking there, but anecdotal evidence shows that they will go for a dip if they feel safe enough. Cooper the chimpanzee and Suryia the orang-utan are extreme examples of this.

Ren

ato

Ben

deR

In BRIeF

Want to lose weight? In your dreams... also rated pictures of high-calorie foods as more desirable than they did after a good rest (Nature Communications, DOI: 10.1038/ncomms3259).

It may make evolutionary sense, says Laurent Brondel at the University of Burgundy in Dijon, France. At higher latitudes, the long summer days naturally deprive animals of sleep, but they use their time awake to eat more food to get through the short days of winter when food is scarcer.

These two captive apes, raised respectively in Missouri and South Carolina, have thrown off any instinctive fear and learned to swim in a swimming pool.

Footage taken by Renato Bender at the University of the Witwatersrand in Johannesburg, South Africa, shows that both of the apes instinctively opted for a version of breaststroke to keep afloat – unusual because almost all other four-limbed mammals use doggy paddle.

Our tree-swinging past may explain the difference. Both humans and the other apes have shoulder joints that can move in all directions instead of in one plane, like the shoulders of most other mammals. That might make breaststroke the natural choice when apes take to the water, says Bender (American Journal of Physical Anthropology, doi.org/nb4).

A LEAD balloon may be a metaphor for something unpopular, but real life clouds of lead are quite the opposite.

Astronomers think that a bloated old red giant star can lose its outer atmosphere to become a hot subdwarf. Subsequently, ions of heavy metals such as lead may rise to the surface after interacting with the light leaving the star.

Now the first two hot subdwarfs with lead clouds have been seen. Naslim Neelamkodan of the Academia Sinica Institute of Astronomy and Astrophysics in Taiwan and colleagues spotted the pair using the Very Large Telescope in Chile. The subdwarfs are a missing link in star evolution (Monthly Notices of the Royal Astronomical Society, doi.org/ncb).

Lead-lined clouds surround stars

130810_N_InBrief.indd 16 6/8/13 10:17:17