Developing brains constantly sprout new synapses as they learn and remember. Important connections — the ones that are repeatedly introduced, such as how to avoid danger — are nurtured and reinforced, while connections deemed unnecessary are pruned away. Adult brains undergo similar pruning, but it was unclear how or why synapses in the adult brain get eliminated.

Now, a team of researchers based in Korea has found the mechanism underlying plasticity and, potentially, neurological disorders in adult brains. They published their findings on December 23 in Nature.

“Our findi...

A multitasking nanomachine that can act as a heat engine and a refrigerator at the same time has been created by RIKEN engineers. The device is one of the first to test how quantum effects, which govern the behavior of particles on the smallest scale, might one day be exploited to enhance the performance of nanotechnologies.

Conventional heat engines and refrigerators work by connecting two pools of fluid. Compressing one pool causes its fluid to heat up, while rapidly expanding the other pool cools its fluid...

There’s something a little off about our theory of the universe. Almost everything fits, but there’s a fly in the cosmic ointment, a particle of sand in the infinite sandwich. Some scientists think the culprit might be gravity—and that subtle ripples in the fabric of space-time could help us find the missing piece.

A new paper co-authored by a University of Chicago scientist lays out how this might work. Published Dec. 21 in Physical Review D, the method depends on finding such ripples that have been bent by traveling through supermassive black holes or large galaxies on their way to Earth.

The trouble is that something is making the universe not only expand, but expand...

Blocking gene expression in mitochondria in mice stops cancer cells from growing. A newly developed compound starves cancer cells by attacking their “power plants” — the mitochondria. The new compound prevents the genetic information within mitochondria from being read. Researchers from the Max Planck Institute for Biology of Ageing in Cologne, the Karolinska Institute in Stockholm and the University of Gothenburg report in their study that this compound could be used as a potential anti-tumour drug in the future; not only in mice but also in human patients.

Mitochondria provide our cells with energy and cellular building blocks necessary for normal tissue and organ function...