Scientists at the University of Pennsylvania have identified a receptor that plays a key role in restricting embryonic stem cells’ pluripotency, their ability to develop into virtually any of an adult animal’s cell types.
The work is the first demonstration of a mechanism by which pluripotency is lost in mammalian embryos, one that operates with nearly the precision of an on/off switch in mouse embryos.

With further study, the receptor, dubbed GCNF, could open the door to new ways of c

Keeping parks pretty means tailoring the trees to their source of water.

Irrigation water recycled from sewage can damage many plant species, new research has found 1 . The results show that landscape architects should tailor their choice of plants to the type of water they will receive.

Dale Devitt of the University of Nevada at Reno and colleagues began studying the effects of different water sources on plants after reports that ’reuse’ water had damaged tr

In 1998, Paul F. Hoffman and Daniel P. Schrag at Harvard University put forth a chilling description of earth’s climate some 650 million years ago. Their theory, dubbed snowball earth, held that between 750 million and 580 million years ago, ice repeatedly enveloped our planet, coating the seas from pole to pole and killing off early life almost completely. During the past few years, the idea has stirred up a great deal of debate. And new data published in the December issue of Geology only furt

World’s smallest reptile is discovered in the Caribbean forest.

At just 16 mm from nose to tail, the Jaragua lizard is the world’s smallest. In fact, it’s the smallest vertebrate that can reproduce on dry land 1 .

The newly discovered lizard lives on Isla Beata, a small, forest-covered island in the Caribbean off the Dominican Republic. Blair Hedges, an evolutionary biologist at Pennsylvania State University, together with Richard Thomas of the

A balanced portfolio of programs could mean a faster quantum computer.

Strategies from the world of finance could help get the best out of quantum computers, say US researchers 1 . The right portfolio of programs could solve a problem many times faster than a single strategem.

Quantum computers – purely hypothetical as yet – would be fast, but you could never be sure whether a program was going to work or not. You would have to keep running the program until

Radon may pose a greater cancer threat than has been thought.

Radon damage from irradiated cells spreads to their neighbours, a new study finds 1 . The result suggests that small amounts of this radioactive gas could cause widespread harm.

The study “is a reason for concern but not panic”, says Gerhard Randers-Pehrson of Columbia University, New York, a member of the team that performed the study. “We’re talking about the acceptable level of radon changing pe