Washington, September 3: A new study, led by researchers at the University of Colorado at Boulder, US, has indicated that the growing number of dams and other impoundments is increasing the number of invasive species and the speed at which they spread, putting natural lakes at risk.

The research team combined data on water chemistry, the distribution of five “nuisance invaders” and boating activity from the Great Lakes region.

According to CU-Boulder Assistant Professor Pieter Johnson, co-lead author of the study, the results showed the increasing occurrence of such species in impoundments creates “stepping-stone habitats” for them into natural lakes, ponds and waterways in the region.

Washington, Sept 3: Kids who have television or computer in their rooms sleep less during the school year than their peers who don't have the facilities, a new study has found.

The joint study conducted by Prof. Yael Latzer and Dr. Tamar Shochat of the University of Haifa and Prof. Orna Chishinsky from Jezreel Valley College examined 444 middle school pupils with an average age of 14.

The children were asked about their sleep habits, their use of computer and television, and their eating habits while watching TV or using the computer.

Washington, September 3: Computer scientists from Stanford University in the US have developed an artificial intelligence system that enables robotic helicopters to teach themselves to fly difficult stunts by watching other helicopters perform the same maneuvers.

The result is an autonomous helicopter than can perform a complete airshow of complex tricks on its own.

According to Andrew Ng, the professor directing the research of graduate students Pieter Abbeel, Adam Coates, Timothy Hunter and Morgan Quigley at Stanford, the stunts are by far the most difficult aerobatic maneuvers flown by any computer controlled helicopter.

Washington, September 3: Scientist at the University of California, San Francisco (UNSF) say that irregularities in a constantly active Notch gene in endothelial brain cells may cause a vascular disorder that causes stroke.

The researchers say that their experiments on mice are the first to provide information on both the progression and regression of the brain disorder BAVM, in which arteries and veins get connected directly rather than through capillaries.

The direct connection produces enlarged, tangled masses of vessels that are prone to hemorrhagic rupture, bleeding, and stroke.

Washington, September 3: Scientists at Penn state University in the US have developed a new computational method that would help them investigate the origin of life on Earth.

The team’s method has the potential to trace the evolutionary histories of proteins all the way back to either cells or viruses, thus settling the debate once and for all over which of these life forms came first.

“We have just begun to tap the potential power of this method,” said Randen Patterson, a Penn State assistant professor of biology and one of the project’s leaders.

“We believe, if it is possible at all, that it is within our grasp to determine whether viruses evolved from cells or vice-versa,” he added.

Washington  - President George W Bush called Republican presidential hopeful John McCain the candidate who "understands the lessons" of the terrorist attacks of September 11, 2001, according to excerpts released ahead of his address to the party convention Tuesday.

Bush was set to speak later Tuesday by satellite to convention delegates gathered in St Paul, Minnesota. He was originally to appear in person on Monday but cancelled the visit due to Hurricane Gustav's arrival on the Gulf Coast.