New York, Apr 18 : Gloomy weather might leave you feeling blue but it''s great for the brain, claim scientists.

The negative effect that bad weather has on people's mood actually sharpens their mind, researchers from Australia's University of New South Wales School of Psychology claimed.

"People performed much better on our memory test when the weather was unpleasant and they were in a slightly negative mood," The New York Daily News quoted Professor Joe Forgas, who quizzed shoppers at a Sydney store over a period of two months, as saying.

London, Apr 18 : Staying slim is not only beneficial for you but it''s also good for the planet, say scientists.

Scientists at the London School of Hygiene and Tropical Medicine''s department of epidemiology and population health say food production is a major contributor to global warming.

The research team suggested that a lean population will consume almost 20 per cent less food than a population in which 40 per cent of people are obese.

Transport-related emissions will also be lower if people are slim because it takes less energy to move them around.

London, Apr 17 : US researchers are designing a laser-guided microwave blaster to destroy explosives.

The weapon, called the Multimode Directed Energy Armament System, could destroy the electronic fuse of an explosive device or missile, such as a roadside bomb, or immobilise a vehicle by disabling its ignition system, reports New Scientist.

It works by creating a plasma channel that acts as a waveguide for the stream of microwaves, and uses a high-power laser to ionise the air.

The project is the brainchild of the US army''s Armament Research, Development and Engineering Centre (ARDEC).

Washington, April 17: A team of geochemists has come across evidence that Earth''s atmosphere 2.4 billion years ago was oxygen-rich, as pointed out by the origin of sulfur in rocks.

Sedimentary rocks created more than 2.4 billion years ago sometimes have an unusual sulfur isotope composition thought to be caused by the action of ultra violet light on volcanically produced sulfur dioxide in an oxygen poor atmosphere.

Washington, April 17 : Scientists have studied alligators to analyze what life may have been like for dinosaurs at low oxygen levels of 12 percent during pre-historic times.

The scientists chose the alligator as a test subject for the study because they are believed to be the modern relatives of the dinosaurs.

"We knew testing the effects of different oxygen levels would work with alligators because crocodilians have survived in their basic shape and form for 220 million years. They must be doing something right to have survived the oxygen fluctuations," said scientist Tomasz Owerkowicz.

Washington, April 17 : The discovery of an ancient flute in Xinglongwa, China, has suggested that Chinese musical instruments could be 3000 years older than previously calculated.

Traditional Chinese musical instruments are believed to have originated from the reign of Huangdi, or the Yellow Emperor, some two thousand years ago.

But, a flute made of bones, unearthed at the Xinglongwa Site in Inner Mongolian in 1986, has changed the timeline for musical instruments in China.

The ancient flute was made from the bones of bustard, a kind of bird usually seen in Northeast China. The tube is 18 centimeters long, with finger holes still evident.