Game over. Computer scientists at the University of Alberta have solved checkers, the popular board game with a history that dates back to 3,000 B.C.

After 18-and-a-half years and sifting through 500 billion billion (a five followed by 20 zeroes) checkers positions, Dr. Jonathan Schaeffer and colleagues have built a checkers-playing computer program that cannot be beaten. Completed in late April this year, the program, Chinook, may be played to a draw but will never be defeated.

"This is a tremendous achievement—a truly significant advance in artificial intelligence," said Dr.

Astronomers have found a debris disk around HD 15115. As seen from Earth, the edge-on disk resembles a needle sticking out from the star.

Astronomers think the disk's odd imbalanced look is caused by dust following a highly elliptical orbit about the star. The lopsided disk may have been caused by the gravity of planets sweeping up debris in the disk or by the gravity of a nearby star.

The observations were made by Paul Kalas, James Graham, and Michael P. Fitzgerald, all from the University of California at Berkeley.

A singing computer scientist wants to use cutting-edge technology to create Europe's first successful Internet choir.

Dr Barry Cheetham, a senior lecturer in The School of Computer Science at The University of Manchester, is seeking to combine his academic expertise in communications, networks and digital signal processing with his love of choral singing.

He is looking for funding to drive forward a project that will bring together amateur and semi-professional singers across Europe for seamless and polished live performances.

A new National Science Foundation (NSF) report finds the number of U.S. science and engineering (S&E) articles in major peer-reviewed journals flattened in the 1990s, after more than two decades of growth, but U.S. influence in world science and technology remains strong.

The report, Changing U.S. Output of Scientific Articles: 1988 - 2003, finds changes occurred despite continued increases in funding and personnel for research and development. Flattening occurred in nearly all U.S. research disciplines and types of institutions.

In contrast, emerging Asian nations had large increases in publication numbers, reflecting their growing expertise in science and technology. European Union totals also went up.

Although the addition of nutrients to soil helps to maximize crop production, fertilizer can leech nutrients, polluting the water supply. A recent study by researchers at the University of Minnesota shows alternative cropping practices may help to protect the environment by reducing high nitrate levels in surface and ground water caused by conventional fertilizer use.

Nitrogen is one of the most important elements required in agricultural systems for plant and animal production. While treatment with the correct amount of nitrogen-based fertilizer optimizes crop yield and minimizes environmental damage, too much nitrogen can lead to nitrate loss.

Human cells function through the concerted action of thousands of proteins that control their growth and differentiation. Yet, the specific function of most human proteins remains either unknown or poorly characterized.

Diseases being often due to aberrations in the function of key cellular proteins, numerous large-scale research initiatives have been launched internationally to crack the function of all human proteins.

A research team led by Dr. Benoit Coulombe from the Institut de recherches cliniques de Montréal (IRCM) describes a powerful proteomics approach that promises to have a profound impact on our current understanding of the human proteome and the function of its individual proteins.