Taking Viagra could reduce men's fertility, suggest the results of a new study. The anti-impotence drug not only speeds sperm up, researchers found, but it also caused the vital reaction needed to penetrate an egg to occur prematurely.
"Viagra was introduced in 1998 and since then it has been prescribed to over 16 million men," says David Glenn, one of the team that conducted the test tube experiments at Queen's University in Belfast, Northern Ireland.
Researchers at the University of Calgary have found that nerve cells grown on a microchip can learn and memorize information which can be communicated to the brain.
"We discovered that when we used the chip to stimulate the neurons, their synaptic strength was enhanced," said Naweed Syed, a neurobiologist at the University of Calgary's faculty of medicine.
The nerve cells also exhibited memory traces that were successfully read by the chip, said Syed, co-author of the landmark study published in February's edition of Physical Review Letters, an international journal.
Methane has been detected on Mars by three independent groups of scientists. And this could be a sign of life - indicating methane-producing bacteria.
But scientists are advocating caution when interpreting the results, saying that the instruments looking for chemical signatures in the Martian atmosphere are not yet good enough to conclusively detect methane. Even if methane exists on Mars, the gas could be a product of non-biological processes such as active volcanoes.
There is life on Mars, a researcher has announced at a conference - unfortunately it is just spaceship-borne contamination.
"I believe there is life on Mars, and it's unequivocally there, because we sent it," Andrew Schuerger of the University of Florida told the Lunar and Planetary Science Conference in Houston, Texas, recently. He has been granted funding from NASA's planetary protection office to help develop better sterilisation techniques for future missions.
Scientists who trained a monkey to move a mechanical arm using thought alone said on Tuesday that experiments in Parkinson's disease patients show the technique may work in humans, too.
Electrodes implanted in the brains of Parkinson's disease patients transmitted signals that might someday be used to operate remote devices, the team at Duke University Medical Center reported.
In 2000, Dr. Miguel Nicolelis, the neurobiologist who led the studies, made headlines when he trained a monkey to move a robotic arm using thoughts and electrodes implanted in her brain.