A fragment of music by the Austrian composer Wolfgang Amadeus Mozart had its first known public performance yesterday in Nantes, where it had lain for years in a municipal library.

The two pieces with a combined duration of under two minutes were played on the violin by Daniel Cuiller, artistic director of the baroque music ensemble Stradivaria before a small audience of journalists and friends.

The one-page score, which was a fragment from a mass, was donated to the Nantes library by a private collector at the end of the 19th century but had previously been thought to be a copy rather than an original. It was authenticated in 2007 by Ulrich Leisinger, a specialist from the Mozarteum University in Salzburg, who estimated that it could have a value of up to €200,000 at auction.

Mr Leisinger said the sheet had also been certified by an expert in 1839, "at a time when Mozart was certainly considered as a highly respectable composer but certainly not as an icon."

"At the time, no one would have had an interest in making a forgery," he said.

Third of Britons drink too much

More than a third of British adults regularly exceed the government's recommended alcohol limits, official figures showed yesterday.

The advice is for men to regularly drink no more than three or four units of alcohol a day, with a limit of two to three units for women.

But despite increased awareness amongst the public of the risks, 37 per cent of adults exceeded these benchmarks on at least one day in the week and 20 per cent drank more than double on their heaviest drinking day.

The Office for National Statistics figures, based on a 2007 survey, found that people living in "managerial or professional" households were likely to drink more than those in "routine and manual" households.

Drought, heat kills trees in N. America

Trees in the western United States and Canada are dying twice as quickly as they did just 30 years ago, with rising average temperatures almost certainly to blame, researchers reported yesterday.

These thinner and weaker forests will become more vulnerable to wildfires and may soak up less carbon dioxide, in turn speeding up global warming, they said.

The US and Canadian researchers from a variety of agencies and universities studied trees in old-growth forests for more than 50 years to document the die-off, which they say is beginning to outpace replacement by new trees.

Warmer temperatures may be encouraging pine beetles and other organisms that attack trees, the researchers said.

That, along with the stress of prolonged droughts, may be accelerating death rates.

Wood, dung fires feed brown cloud

Wood and dung burned for home heating and cooking make up most of a huge brown cloud of pollution that hangs over South Asia and the Indian Ocean during the winter months, researchers said yesterday.

The study solves the mystery of what makes up the soot in the brown haze linked to hundreds of thousands of deaths - mainly from lung and heart disease - each year in the region.

Orjan Gustafsson, a biogeochemist at Stockholm University led a Swedish and Indian team that used a newly developed radiocarbon technique to measure atmospheric soot particles collected from a mountaintop in India and on the Maldives. They found that two-thirds of the particles in the cloud were made up of so-called biomass, or organic matter like wood or dung, and the rest from fossil fuels.

The cloud which towers up to five kilometres above the ground blankets much of the region in the winter months when temperatures drop and the air is dry. The phenomena is most persistent in Southeast Asia, but has also been identified in large metropolitan areas in Egypt, China, South Korea and other tropical locations.

Fake Dalis seized

Officials confiscated 81 works of art attributed to the Spanish surrealist artist Salvador Dali in the resort town of Estepona in Spain and arrested a French man on charges of fraud, police said yesterday.

The works, including lithographs, textiles, cutlery and a three-metre sculpture of an elephant priced at €1.2 million, had travelled from France and were to be put up for sale at an exhibition in a hotel.

At least 12 of the objects could be genuine Dalis and matched descriptions of works of art stolen in Spain, Belgium, France and the United States, police said.