Despite the large number of casualties at the time, doctors had no way to preserve tissue samples taken from infected patients, so researchers used an ingenious method to overcome this. The preserved body of a flu victim buried in Alaskan permafrost was exhumed, and they painstakingly extracted the genetic material needed to work out the structure of the H1N1 virus. Then, in a maximum "biosafety" facility at Canada's National Microbiology Laboratory they reconstructed a fully functioning virus, and infected macaque monkeys to see what would happen.

Writing in the journal Nature, they reported that the results were startling. Symptoms appeared within 24 hours of exposure to the virus, and the subsequent destruction of lung tissue was so widespread that, had the monkeys not been put to sleep a few days later, they would literally have drowned in their own blood. The results match those seen when mice were infected in an earlier study and are very similar to those described in human patients at the time the virus was at its height.

Darwyn Kobasa, a research scientist with the Public Health Agency of Canada, and lead author of the research, defended the decision to recreate one of the most dangerous viruses in history. He said: "This research provides an important piece in the puzzle of the 1918 virus, helping us to better understand influenza viruses and their potential to cause pandemics." However, it is not the virus that is directly causing the damage to the lungs - it is the body's own response to infection.

Immune system proteins that can damage infected tissue were found at much higher levels following H1N1 infection compared with other viral infections. Analysis at the University of Wisconsin at Madison (UW) revealed that a key component of the immune system, a gene called RIG-1 appeared to be involved. Levels of the protein produced by the gene were lower in tissue infected with the 1918 virus, suggesting it had a method of switching it off, causing immune defences to run wild.

This ability to alter the body's immune response is shared with the most recent candidate for mutation into a pandemic strain, the H5N1 avian flu. Experts are worried that if the virus changes so that it can infect humans easily, it could again be far more lethal than normal seasonal flu. "What we see with the 1918 virus in infected monkeys is also what we see with H5N1 viruses," said Yoshihiro Kawaoka, who led the analysis at UW. "Things may be happening at an early time point (in infection), but we may be able to step in and stop that reaction."

Dr Ronald Cutler, an infectious diseases researcher at the University of East London, said: "Knowing how that over stimulation takes place could lead to the development of new methods to treat these diseases so we are better prepared for any future pandemic." Dr Jim Robertson from the UK's National Institute for Biological Standards and Control, said the decision to recreate the virus was justified. "Many influenza virologists remain nervous about creating and experimenting with a reconstructed 1918 Spanish flu virus, an extremely dangerous virus which disappeared from the world long ago.

The emir was the 13th ruler of a 245-year-old dynasty that has ruled Kuwait since the Anaiza tribe, to which the al-Sabahs belonged, migrated from the Arabian hinterland. Since the fall of Saddam in 2003 and US calls for change in the Middle East, the ruling family had come under intense pressure from both Islamists and pro-Western liberals to loosen its grip on the government and share power.

The ruling family had also been under pressure from parliament and elders within its ranks to break with tradition and replace the ailing crown prince. The succession process alternates between the two branches of the ruling family - al-Jabers and al-Salems.

Kuwait, a founder OPEC member, enjoys one of the world's highest standards of living, despite its reliance on oil exports, unpredictable oil income and huge losses from the 1990-1991 Iraq occupation. It hosts up to 30,000 US troops and some 13,000 US citizens live in the country. Kuwait has cracked down on Islamists opposing the US military presence in the country. Diplomats say radical Islam is taking hold among Kuwaiti youth.

In December, a Kuwaiti court sentenced to death six suspected militants linked to Osama bin Laden's al Qaeda for bloody attacks in the country. The six were among 37 Islamists on trial as members of the "Peninsula Lions" group believed to be linked to al Qaeda in Iraq and Saudi Arabia.

Kuwaitis are mainly Sunni Muslims and about a third of them are Shi'ites, many of them of Iranian descent

China has resolved to shift some of its foreign exchange reserves - now in excess of $800 billion - away from the US dollar and into other world currencies in a move likely to push down the value of the greenback, a high-level state economist who advises the nation's economic policymakers said in an interview Monday.

As China's manufacturing industries flood the world with cheap goods, the Chinese central bank has invested roughly three-fourths of its growing foreign currency reserves in US Treasury bills and other dollar-denominated assets. The new policy reflects China's fears that too much of its savings is tied up in the dollar, a currency widely expected to drop in value as the US trade and fiscal deficits climb.

China now boasts the world's second-largest cache of foreign exchange - behind only Japan - and is on pace to see its reserves climb past $1 trillion later this year. Even a slight diminishing of the dollar as a percentage of those holdings could exert significant pressure on the US currency, many economists assert.

"The general trend for the US dollar is continuously weakening," Yu said, speaking to reporters at a conference in Beijing last month. "Countries with huge foreign-exchange reserves will have their assets shrunken."

Even if a Chinese shift away from the dollar weakened the currency, that would probably not soothe tensions with those in Washington calling for an increase in the value of the yuan to help US manufacturers. Unless China severs the link between the value of its currency and the dollar - a move Beijing says could destabilize its economy - then a weaker dollar would simply mean a weaker yuan as well, leaving in place the current debate over whether China's export earnings are being netted unfairly.

Dr Hwang's landmark claim to have cloned human embryonic stem cells was false, a university panel concluded. But the panel, which last month rejected other research by Dr Hwang, has accepted that he did create the world's first cloned dog.

Dr Hwang has admitted errors, but claims his work was sabotaged. State prosecutors are now expected to look into the case. The BBC correspondent in Seoul, Charles Scanlon, says the conclusion of the university's investigation completes the disgrace of Dr Hwang, who was South Korea's most celebrated scientist.

Dr Hwang claimed in a 2004 paper published in the US journal Science that his team had produced a line of stem cells from a cloned human embryo. The achievement was judged to be a major scientific breakthrough in the search for cures for a range of degenerative diseases including diabetes and Parkinson's.

But the nine-member Seoul University panel, which spent a month examining Dr Hwang's work, said in a statement on Tuesday: "The 2004 paper was written on fabricated data to show that the stem cells match the DNA of the provider although they didn't."

The South Korean team "did not have any proof to show that cloned embryonic stem cells were ever created," the panel concluded. The same panel revealed last month that a later paper which seemed to take Mr Hwang's cloning work even further was also faked.

The shaming of Dr Hwang has come as a profound shock to South Koreans, many of whom saw the cloning pioneer as a national hero. Some analysts are describing his fall from grace as one of the biggest cases of scientific fraud in recent history.

Dr Hwang has not made any public appearances since saying he would resign his faculty position last month, and his current whereabouts are unknown. But there was some positive news for the beleaguered scientist on Tuesday.

The university panel ruled that an experiment last year in which Dr Hwang's team claimed to have cloned a dog was genuine. A three-year-old Afghan hound called Snuppy - short for Seoul National University puppy - was genetically identical to his father according to DNA tests, the panel found.

Somalia has not had a proper government for 16 years. Instead, warlords have been fighting for control of territory. Local Islamic courts were set up by businessmen who wanted someone to catch and punish thieves and people who do not respect their contracts.

Some of these courts joined to form the Union of Islamic Courts (UIC) and their small groups of gunmen became Somalia's strongest fighting force.
The UIC is divided between moderates and hardliners.

They all say they want to restore stability and law and order to Somalia.
Hardliners also want to curb foreign influences, which they say are immoral. They have closed down cinemas showing foreign films and football matches.

Some radio stations have also been told not to play foreign music or local love songs but other radio stations and cinemas have been left alone. The UIC have also staged public executions and floggings of people they have found guilty of crimes such as murder and selling drugs.
After years of lawlessness, many Somalis are happy to have some kind of law and order.

The prices of many basic foods have fallen because gunmen no longer extort money from lorries taking goods to markets. Almost all Somalis are Muslim but some are wary of the hardline elements. They do not like the harsh punishments and do not want to be cut off from the rest of the world.

The Athens Geodynamic Institute said the quake, with a preliminary magnitude of 6.9, occurred off the coast of the small island of Kithira, about 125 miles south of Athens at 11:34pm (11:34 GMT) on Sunday. Its epicentre was at a depth of about 43 miles beneath the sea - which likely contributed to the lack of major damage or serious injuries, seismologists said. It shook the entire region, from Italy in the west to Egypt and Jordan in the east, and was felt throughout Greece.

Clarice Nassif Ransom, a Washington spokeswoman for the US Geological Survey, said scientists project that as many as six million people may have felt the earthquake.

"It was a very powerful quake which shook all of Greece," said Giorgos Stavrakakis, head of the Athens' Geodynamic Institute. "There have been dozens of aftershocks, 4 with a magnitude of 5... The quake occurred deep undersea and that's what saved us."

Since Mao's death in 1976, China has changed enormously, racing to catch up with the rest of Asia.

Mobile phones and cameras have become must-haves - everywhere you go, people are talking, texting, and surfing. An explosion of capitalism has given cities like Shanghai and Beijing futuristic skylines. Big business and consumer technology alike have found a new home here.

The country is already the world's largest producer of mobile phones, PCs and cameras, which it can churn out in their millions - and all because of China's biggest resource: people.

It is worth taking a minute to look at the statistics, because they are truly amazing. China is the world's most populous country, with 1.3 billion people.

On size alone, it is fast becoming a technology superpower and it almost has no choice in the matter. For example, even though only 8% of its people have access to the internet, this equates to 100 million people online, second only to the US.

The Chinese Government is very keen to make sure its internet infrastructure is up to the job. It is quite literally bringing its people up to speed.

Dorothy Yang, research director at IDC Analysts, told Click: "About 70 to 80% of internet users use broadband. One reason is that broadband access is quite cheap in China - it only costs about $10-15 a month for unlimited internet access."

No longer just a tech producer, China is becoming a gargantuan tech consumer.

China is dotted with rabbit warrens of small electronics boutiques, selling everything from known brands to home-made kit, multi-coloured CDs to 2GB memory cards. No-one can accuse the Chinese of being behind the times.

It will come as little surprise that China is now the world's largest cell phone market, with more than 380 million mobiles. And, just like internet penetration, the number is rising at an impressive rate. Just like the rest of the world, they are in love with their phones.

But perhaps here, more than in most countries, phones have an added value. In a place where public displays of affection and freedom to say what you want are still not to be taken for granted, mobile phones offer new privacy for conversation and romance.

Walk into a mobile phone store and you are offered only two choices of network, but a multitude of home-made brands of handset, some designed to satisfy even the most demanding user: I found one box that was a MP3 player, an MPEG4 video player, a PDA, a two megapixel camera with flash and a video camera.

Nonetheless, despite all the bells and whistles, the home-made jobs often lack the style and glamour of the established brands, which most Chinese still opt for.

China's reputation as a source of cheap labour and cheap goods is being challenged - there is also innovation here. In 2000, Click spoke to Jack Ma, a budding Chinese entrepreneur who had dreams of setting up a web service aimed at connecting traders across China, to help them find the best price for goods and services.

Five years on, he is one of the richest men in the country. He runs a range of online marketplaces, under the brand name Alibaba, including TaoBao, a rival to eBay, and an online payment system. In China, business is a very personal thing, but Jack seems to have persuaded people that they can do business on the web. He says: "The internet is a community; don't think it's just computers. Only if you build your website like a community can your company grow fast." As to whether China can become a technology superpower, Jack believes this will take time and luck.

"Today I don't think people should have expectations of that. It is true that China is growing very fast on the internet, but the other challenge is encouraging innovation and creativity, which takes a very long time. People are surprised by China because it's been like a sleeping lion for years. Now it's starting to jump and people say: 'oh my God, it's growing so fast' but it's not that scary."

Jack also relishes challenging the dominance of the US in the technology world. "Otherwise I would not compete with eBay or Google", he says. "They could be very successful in the US, in the West, but in China? No, because we're more entrepreneurial than them, in China today. They were very entrepreneurial 25 years ago, but today they're not entrepreneurial at all. They're very corporate."

China is so ready to compete with US technology that, in one particular case, it bought the company. In December 2004, Chinese PC manufacturer Lenovo did the unthinkable - it bought part of IBM. The part, that is, that makes PCs. Lenovo was already China's largest PC maker but, after the IBM deal, it has shot up from 9th largest to 3rd largest PC manufacturer in the world. Lenovo's Alice Li told Click: "It's a very important transaction for us. For Lenovo that acquisition makes us a truly international company. We've accumulated an international management team and reputable international brands - for example, Thinkpad - and all the patented technology related to that brand. And we also now have an immediate worldwide distribution network."

Lenovo seems determined to continue pushing the country's technology scene by thinking big and aiming high. It could very well become China's first truly international company. China has the size, and it is showing signs of determination to spread its influence beyond its borders.

At the dawn of a new century, there is a new kid on the block.

In case the US or Israel use conventional bombs against Iran's nuclear facilities, the Iranians are expected to retaliate with missiles against the occupying forces in Iraq and against Israel, as well as the occupation military bases in southern Iraq, that the 150,000 US troops in Iraq would not be able to withstand, the article further suggests, adding that the Iranian missiles could potentially contain chemical warheads, and it certainly would be impossible to rule out such possibility.

The US's use of low-yield nuclear bombs with better bunker-busting ability than conventional bombs targeting Iran's nuclear, chemical and missile installations, which would be consistent with the new US nuclear weapons doctrine, will be then justified using the claims of needing to protect the lives of 150,000 US soldiers in Iraq and of Israeli citizens.

New US policies that involve the use of nuclear weapons were formulated in the administration document "Nuclear Posture Review" of 2001 and became more defined in a Pentagon draft document "Doctrine for Joint Nuclear Operations," Jorge Hirsch, a professor of physics at the University of California San Diego, wrote in an article published on a San Diego Union-Tribune website.

These policies, the drafters of which occupy the upper echelons of the Bush administration, allow the use of nuclear weapons against adversary underground installations, against adversaries using or intending to use weapons of mass destruction against US forces and for rapid and favourable war termination on US terms.

Hirsch suggests that those policies could be implemented in the near future against the Persian Gulf.

Americans are quite well advanced in their planning for the use of those weapons, which raises the fears that other countries will, out of fear, try to build their own. A new concept of warfare is being developed.

GAS CUT IMPACT:

Ukraine - loses 100% of Russian imports.

Hungary - Russian imports down 40%.

Poland - supply down 14% on Sunday. Seeking to increase supplies from alternative pipe.

Austria, Slovakia, Romania - supplies down by a third.

Germany - no problems yet, but later cuts to big firms "not ruled out".

France - heavy user of Russian gas, but no problems likely yet.

Countries as far west as France say supplies from a pipeline running via Ukraine have fallen by up to 40%.

Ukraine denied taking the gas, but said it would siphon off a share if temperatures fell much below freezing.

The row erupted after Russia raised the price of 1,000 cubic metres of gas from $50 to $230 and Ukraine refused to pay.

Russia's gas monopoly Gazprom is still charging the lower price to some former Soviet countries, though the average price in the EU is $240 (140 pounds).

Moldovan President Vladimir Voronin said his country had also been cut off, after refusing to pay $160 per 1,000 cubic metres, according to the Itar-Tass news agency.

Kiev says it is being punished for its attempts to become more independent from Moscow and develop stronger ties with the West.

In a statement on Sunday night, it accused Russia of resorting to "blackmail" in order to undermine the country's economy.

At the early stages of Bush's second term, Vice President Dick Cheney dropped a bombshell, hinting that Iran was "right at the top of the list" of the rogue enemies of the United States, and that Israel would, so to speak, "be doing the bombing for us", without US military having to ask them "to do it".

"One of the concerns people have is that Israel might do it without being asked. Given the fact that Iran has a stated policy that their objective is the destruction of Israel, the Israelis might well decide to act first, and let the rest of the world worry about cleaning up the diplomatic mess afterwards" (quoted from an MSNBC Interview Jan 2005).

Amid numerous media reports' predictions that the United States, backed by Israel, will launch a military strike, targeting Iran's nuclear sites in 2006, Germany's Der Spiegel suggests that speculation about a US attack against the Islamic republic is particularly rife in NATO-member Turkey.

The threats followed a steep rise in the price of petrol earlier this month, ordered by the government. The oil ministry said the shutdown at Baiji was costing $20 million (12 million pounds) a day. The ministry said it hoped the refinery, which has been out of action since the weekend, would be back up and running within days.

"Efforts are being made to convince the drivers to return to work," a spokesman said. The Baiji refinery normally produces 8.5 million litres (2.2 million gallons) of petrol per day, along with 7.5 million litres of diesel.

Oil distribution has been further disrupted by storms that have prevented exports being shipped from the Basra terminal in the south, Reuters said. Although billions of dollars have been spent on infrastructure since Saddam Hussein's regime was toppled, fuel and electricity production have not reached the levels maintained before the US-led invasion of Iraq.

The major injury was inflicted by the "No" votes in France and the Netherlands, sapping morale and purpose from the EU's leaders. But this was preceded by the European Parliament flexing its muscles. All they did was reject a commissioner because of his Roman Catholic views on homosexuality, but some think this unsteadied the Commission and robbed it of courage.

And in June, when UK Prime Minister Tony Blair vetoed a budget and declared war on the Common Agricultural Policy, the EU was stunned. I mean, almost literally. Not surprised, but temporarily deprived of the ability to think or move by the force of these blows. The agonies that the EU suffered this year were growing pains.

According to your political taste, you can argue that they were the normal twinges and emotional problems of healthy adolescence or a Frankenstein monster rejecting bits unnaturally bolted on to a grotesque body. But growing pains, nonetheless.

Discerning the reasons behind the "No" votes on the constitution has been a bit of a political parlour game. Perhaps it was not a very good document. It certainly was not a very inspiring one. There were doubtless French men, as hostile to the EU as British Conservative Bill Cash - who voted "No" to reject the whole project.

There were probably Dutch women who voted "No" because they were disappointed at the lack of fast political integration. And some who were doing the political equivalent of kicking the cat. But surely overall it was a rejection of the implications of enlargement, the growth of the EU to 25 states, and a feeling the EU was too distant and didn't do anything useful?

Tony Blair picked up the last point and used his presidency as a bully pulpit for a more economically relevant Union. That argument will continue in fits and starts, fought over the services directive and other pieces of legislation.

But while there have been wrinkled noses at the idea of Turkey joining there has been no grown-up debate about enlargement.

In 2006 that will happen. The Austrians, who are next in the hot seat, want the EU to look towards the Balkans. There will be questions over whether Romania and Bulgaria are ready to join, and how much it will cost. And then the bigger question - is that it?

Ukraine, perhaps. Switzerland and Norway, if they ever wanted to join. But after that? There surely has to be a debate on whether the EU is a geographical entity or a state of mind. And in 2006 European leaders will get over their trauma and discover their tongues over the constitution. The Austrians and Germans clearly want to bring bits of it back, which will cause fury in some quarters.

French President Jacques Chirac says he has a cunning plan for greater democracy. The old idea of an "inner core" of nations ready for greater political union will be back. This is fraught. On the one hand, it is easy to see that a 25-strong EU cannot manage very well with the current rules. On the other, it is clearly - although not clear to some - awkward to ignore the democratic will of millions of people.

Some people worry that politics no longer deals in the big questions. The European Union does. In 2006, like a tortured teenager, it will continue to ask "Why are we here?"

The People's Bank of China, the central bank, raised the upper limit for rates on one-year US dollar deposits to 3 per cent from 2.5 per cent. The ceiling on one-year Hong Kong dollar deposits was increase by 25 basis points to 2.625 per cent. The adjustments become effective Wednesday.

This is the fifth time the Chinese central bank has raised interest rates on key foreign currency deposits this year, following a similar but smoother upward curve of rates in the United States. The dollar rate ceiling was a much lower 0.875 per cent at the beginning of the year.

"Looking at the whole year, the policy intention is quite clear," said Zhang Xuechun, a Beijing-based economist with the Asian Development Bank.

Although China's monetary authorities do not give details about every policy move, Zhang said yesterday's hike was an effort to keep pace with the rate-hiking wave by the Federal Reserve in the United States. It would keep interest differentials from widening too much.

The Federal Reserve raised its target for its federal funds rate by 25 basis points earlier this month to 4.25 per cent, the 13th rate hike since June last year.

Zhang said another reason for the Chinese move was to encourage local residents to deposit more in foreign currencies instead of in the Chinese currency, the renminbi, to help reduce the upward pressure on the local currency.

"After the exchange rate reform, interest rate policy must be more responsive to smoothen exchange rate fluctuations," Zhang said.

China announced a long-awaited exchange rate reform in July 21, allowing the renminbi to appreciate by 2 per cent and linking the currency to a basket of foreign currencies instead of the US dollar alone.

Expectations for further renminbi appreciation remain strong, as major trading partners keep pressing China for a stronger renminbi, which they believe is undervalued.

The renminbi has been on an upward trend against the dollar since the reform, although movements in both directions are frequently recorded.

Scientists have been unable to link the spread of the virus to migratory patterns, suggesting that the thousands of wild birds that have died, primarily waterfowl and shore birds, are not primary transmitters of bird flu. If that holds true, it would suggest that shipments of domestic chickens, ducks and other poultry represent a far greater threat than does the movement of wild birds on the wing.

It also would underscore the need to pursue the virus in poultry farms and markets rather than in wild populations of birds if a possible pandemic is to be checked, US and European experts said.

The H5N1 strain has infected millions of poultry throughout Asia and parts of Europe since 2003. The virus also has killed at least 71 people, many of whom had close contact with poultry. To date, the virus hasn't been shown to spread from person to person, but many fear that it could mutate into a strain that could, potentially killing millions in a global pandemic.

While the prospect that migrating birds could carry the virus worldwide still worries health authorities, that sort of scenario doesn't appear to be playing out.

There is more and more evidence building up that wild migratory birds do play some role in spreading the virus, but personally I believe - and others agree - that it's not a major role, said Ward Hagemeijer, a wild bird ecologist with Wetlands International, a conservation group in Wageningen, Netherlands. If we would assume based on this evidence that wild birds would be a major carrier of the disease we would expect a more dramatic outbreak of the disease all over the world.

Reports this summer and fall of the spread of the H5N1 strain strongly suggested wild birds were carrying the disease outward from Asia as they followed migration patterns that crisscross the Earth. The timing and location of outbreaks in western China, Russia, Romania, Turkey and Croatia seemed to point to wild birds en route to winter grounds.

That put places like Alaska, where birds from the Old and New Worlds gather each summer to create what some call an international viral transfer center, on alert that the virus could arrive this coming spring. And from there, species like the buff-breasted sandpiper and others that split their time between North and South America could in theory transport the virus farther afield.

Since the early fall, however, there have been only scattered reports of more outbreaks. The disease has been glaringly absent, for example, from western Europe and the Nile delta, where many presumed it would crop up as migrating birds returned to winter roosts.

That suggests the strain has evolved to specifically exploit domestic poultry, whose short lives spent in tight flocks mean a virus has to skip quickly from bird to bird if it is to survive, said Hon Ip, a virologist with the US Geological Survey's National Wildlife Health Center in Madison, Wisconsin.

That also means that while the virus can pass from domestic to wild birds, the latter may not be suited as transmitters of the strain - at least so far. By the timing of the spread and the pattern of outbreaks within a country and between countries, it does not make sense relative to a role for migratory birds as a means of spreading the virus.

For example, the virus killed thousands of bar-headed geese in May and June at Lake Qinghai in western China. The deaths raised immediate fears that the virus was on the move, jumping among hosts in the wild. In the August 19 issue of the journal Science, scientists wrote that the virus has the potential to be a global threat.

But Ip and others suggest the lake is not as remote and pristine as initially portrayed, and that poultry raised in the area could have been the source of the flu strain that killed the geese.

It is still patchy - the pattern of outbreaks - to really make a very definitive link between migratory birds and the disease, said Marco Barbieri, the scientific and technical officer for the United Nations Environmental Program's convention on migratory species in Bonn, Germany.

Experts caution that wild birds cannot be ruled out as future transmitters of the H5N1 strain, which has yet to be detected in North America. Migratory birds, for example, have been clearly implicated in the spread of West Nile virus, which has killed at least 762 people in the US since 2002.

The H5N1 flu strain already is known to be lethal to nearly 60 species of birds; further mutations of the strain could allow it to infect many more. One of the latest victims is the Asian tree sparrow, according to a study published in the December issue of the Journal of Virology.

The dogma right now is it is the waterfowl - ducks, sandpipers, gulls, plovers - essentially any bird that is water-associated, said A Townsend Peterson, a University of Kansas professor and curator of the school's Natural History Museum and Biodiversity Research Center. I will predict that that dogma will eventually fall by the wayside. I will guess that what we will eventually see is that avian influenza is much more widely distributed among birds and that land birds also play a significant role in the picture.

That has made increasing the understanding of the migratory routes followed by birds more important than ever. It also draws attention to how little is still known about the routes.

The conventional maps that show flyways as fat arrows that can span continents and oceans lack the nuance and detail of how birds really move, including when and in what numbers, experts said. The maps also can gloss over how migratory patterns can vary among subspecies.

Traditional methods like bird watching and banding are helping flesh out the maps. And now tracking by satellite or radio, as well as genetic and isotopic sampling, are playing an increased role in sussing out the finer details of where birds travel and when.

In places like Alaska, where millions of individual birds representing more than 200 species arrive each spring, scientists readily confess the situation isn't all clear.

Fuzzy would be an operative word. We are in the process of defining the Alaskan migration system, and it is remarkably complex, said Kevin Winker, curator of birds and an associate professor at the University of Alaska, Fairbanks.

In the United States, the US Geological Survey, Fish and Wildlife Service and the Agriculture Department plan next year to step up their surveillance of wild flocks of birds.

In the past several weeks, scientists have winnowed down their list of birds they want to keep tabs on, said Dirk Derksen, a biologist with the USGS Alaska Science Center in Anchorage. All spend at least part of the year in Asia.

Early detection would buy time in forestalling the further spread of the virus - a situation no one wants.

Initially, wild birds are primarily victims. Someday they may become vectors. We don't know how that will play out, Ip said. What I would like to see is the virus stopped before it gets to America so we don't see the last reel of this film played out in North America.

According to figures gathered by security firm Symantec, there were 33 serious outbreaks in 2004. These are incidents measured by the number of people a virus infects or the severity of the damage they inflict. In 2005, there were only six such incidents.

"We're talking about a substantial decrease in worldwide pandemics," said Kevin Hogan, senior manager in Symantec's security response team. This decline is taking place because virus makers have largely stopped spreading their malicious wares with mass-mailers that try to infect as many people as possible via their inbox.

Instead, virus creators are cranking out more versions of malicious programs than ever before. Year-end statistics from Finnish anti-virus firm F-Secure show that there were 50% fewer virus outbreaks in 2005 but the number of malicious programs has grown by, on average, 40% for the last two years. Similarly Sophos reported that it found 1,940 new malicious programs in November 2005, the largest increase since records began.

Evidence for this rash of variants can be found in the list of the top 20 viruses for 2005 compiled by Kaspersky labs in which the MyTob virus fills nine places. Security experts say this explosion in variants is partly driven by a desire to overwhelm anti-virus firms. With defences spread thinly, hackers believe they will have more time for their particular creation to infect machines.

The malicious hackers are also keen to replenish the ranks of the viruses circulating online as fixes are found for previous versions.

It also marks a tactical change toward more customised attacks. Instead of trying to infect everyone, many virus creators are creating variants that attack small groups of users.

Sometimes these are customers of particular companies, often banks, and occasionally they are the workers in a single organisation. Smaller groups are being targeted because many of the groups sending out viruses are criminals keen to profit from the machines they compromise.

Mr Hogan from Symantec said there was only circumstantial evidence in 2004 that criminals were getting involved in viruses, spam and phishing. But in terms of this year, he said: "With customers and others we have seen clear evidence that this is being done for money."

Virus writers can make money by renting out control of the machines they have compromised as spam relays, pop-up ad networks, for mounting net attacks or as hosts for illegal material. It is not just virus writers that are customising their attacks. This year has also seen phishing gangs refine their methods to try to improve their success.

For instance, in August 2005, customers of Swedish bank Nordea received an e-mail in their local language that tried to make them visit spoof websites and type in security codes. Notified about the attack, Nordea shut down its online arm while it made sure no money had been illicitly transferred. Other custom attacks have been launched against players of online games, such as Lineage, in an attempt to steal player accounts.

Not all malicious hackers make money by stealing it. 2005 saw large numbers of tech savvy criminals generating significant incomes by compromising computers so people are bombarded with pop-up ads or have their web browser hijacked so it takes them to sites they would not otherwise visit.

Behind these pop-up bombardments and browser hijackings are so-called adware and spyware programs. These can be contracted by visiting the wrong website which forces the installation of adware; by downloading applications such as file-sharing programs in which the adware lurks or by following a link in an e-mail.

Online security firm ScanSafe, which cleans up web traffic for customers, said the amount of spyware it had blocked was doubling every month since it started its monitoring program earlier in 2005.

It also said that the number of web-based attacks that try to install spyware and adware had grown by 165% in the last 12 months. Spyware makers were working hard to stop their creations being found said Eldar Turvey, chief executive of ScanSafe.

"Spyware is becoming more stealthy," said Mr Turvey. Many viruses are designed to be disposable but spyware makers want their creations to persist. Many spyware makers were disguising the data their programs send back by making it look like ordinary web browser traffic that easily slips through firewalls.

One final worrying trend seen in 2005 was the emergence of attacks aimed at security software. Many makes of anti-virus, firewall and PC protection programs are seen as a weak link by hacker groups. Many are trying to subvert the programs that are supposed to protect users and exploit weaknesses to give them access to users' machines.

PC SAFETY TIPS:

Install anti-virus software. Update it daily

Regularly scan your PC to ensure it is clean of viruses

Install a firewall. Keep it updated

Use one or more spyware scanners. Keep them updated and scan your PC regularly.

Do not respond to unsolicited e-mails bearing attachments.

Keep Internet Explorer updated or use another web browser

Be careful to check what also comes with anything you download from the web

Keep Windows updated and apply patches for security loopholes

Be careful where you visit online. Some sites may harbour spyware.