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 earths 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
Worlds smallest reptile is discovered in the Caribbean forest.
At just 16 mm from nose to tail, the Jaragua lizard is the worlds smallest. In fact, its 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
The question of which forces control terrestrial ecosystems lies at the heart of a long-standing debate among ecologists. One theory, the so-called bottom-up theory, suggests that plant defense mechanisms exert control by limiting food availability for herbivores. Top-down theorists, however, suggest that predators limit the numbers of herbivores and hence their impact on the vegetation. Now new findings in the current issue of the journal Science that describe animal communities isolated for 15 year
For more than 150 years, people around the world have made ample use of the explosive trinitrotoluene, otherwise known as TNT. Its use has had unintended consequences, however: the manufacture, storage and disposal of TNT—which ranks among the most toxic explosives employed by the military—have left large areas of land contaminated and polluted. So far, effective and affordable cleanup technologies have remained out of reach. But new research suggests that help may come from what might seem an unlike
Surprising black hole weigh-in has astronomers scratching their heads.
Forty thousand light years away, on the other side of the Milky Way, lies object GRS1915+105. It is a giant star and a black hole orbiting one another, blasting out X-rays and ejecting gas and dust at close to the speed of light.
Now measurements of this “extreme and puzzling” object are casting doubt on current theories of how such binary systems form and behave. Astronomers have weighed its black hole,
Generally speaking, we go to great lengths to rid our bodies of foreign bacteria, whether it’s by brushing our teeth, washing our hands or taking antibiotics. But new research suggests that when it comes to treating tumors, we may one day invite the bugs in. According to a study published yesterday in the early online edition of the Proceedings of the National Academy of Sciences, a bacterium that normally resides in soil, dust and dead flesh quickly destroys large tumors in mice when injected along
In the coming years and decades, various nations want to explore the moon, and plan to send astronauts there again for this purpose. But on our inhospitable satellite, space radiation…
For over 15 years, ETH Professor Andreas Hierlemann and his group have been developing microelectrode-array chips that can be used to precisely excite nerve cells in cell cultures and to…
Current practices of the poultry industry have raised ethical and ecological concerns: ethical concerns include the culling of day-old male chicks of egg-laying breeds; ecological concerns include the import of…
Stripe rust is one of the most destructive wheat diseases in the world, especially in the United States. While the disease can be controlled by chemicals, those may be harmful…
Orchids are quite decorative. However, many orchid species are also threatened by land conversion and illegal harvesting. But only a fraction of those species is included in the IUCN Red…
These systems could potentially overcome computational hurdles faced by current digital technologies. In the September issue of the journal Nature, scientists from Texas A&M University, Hewlett Packard Labs and Stanford…
3D nonlinear ferro-fluid-based hyperbolic metamaterials may contribute to ultra-fast all-optical hyper-computing. Metamaterials–nanoengineered structures designed for precise control and manipulation of electromagnetic waves–have enabled such innovations as invisibility cloaks and super-resolution…
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