Testicle cells to treat disease
Doctors in the United States may soon be using tissue from testicles to treat brain diseases such as Parkinson's and Alzheimer's.

Look down to look up
The American Space Agency, Nasa, has been explaining its research programme to look for extraterrestrial life.

America's alien invasion
The United States has been invaded by alien plants and animals that are costing the country $123bn each year.

Awesome power of IT
Vice President Al Gore used his speech to the American Association for the Advancement of Science (AAAS) annual expo to celebrate the revolution that has taken place in information technology.

Sound experiments
The AAAS expo has been presented with an extraordinary and unique array of musical instruments - but can you stand the noise they make?

Smoking cities
Children are having to breathe in so much air pollution in some major cities in the developing world that they are comparable with heavy smokers, scientists are told.

Goodbye mother tongue
As many as 40% of the world's languages could disappear in the next 100 years as the media and the world economy give us more common ways of speaking.

Genome defence strategy
A project to sequence the genes in potential biological weapons should be considered by governments, scientists said on Sunday.

Creating artificial bugs
Scientists may soon have the ability to create completely new living organisms from the raw chemical building blocks of life.

Heart in a box
A Canadian scientist has outlined his plans to create complete human hearts for transplant operations.

Sting in the tail for cancer
The venom used by scorpions to paralyse their prey could be the next big thing to fight brain tumours.

Trouble with time
Working out when the new millennium should really start is a baffling exercise in the pointless, argues one Harvard academic.

The word on gum disease
Researchers have shown that gum disease may lead to heart disease and premature babies.

Drug-resistant HIV fear
The drug warfare being waged on the HIV virus could end up making the epidemic worse, scientists have warned.

The more the fitter
Scientists say there may be evolutionary advantages if children have more than one "father".

Foreskin foresight
The discarded skin from circumcision operations is providing the cells scientists need to make spare tissue for transplants.

Children's guide to survival
Simple emotional support is what helps children survive, even in the riskiest of environments where poverty, abuse, or the danger of being killed are the hazards of everyday life.

Challenges for a new century
One of the world's biggest scientific meetings has opened in California with researchers being asked to look towards the next millennium.

A little goes a long way
Many people may be able to extend their lives by eating smaller amounts of food, according to preliminary findings presented to the AAAS meeting in California.

Meet moviestar Monty
Delegates to a big science conference in California have had a sneak preview of the future of moviemaking.

America's festival of science
The BBC reports from the American Association for the Advancement of Science meeting in Anaheim.

Quake warnings to be bleeped
Bleepers will be used to warn the emergency services and local residents when a big quake is about to strike California.