The group hopes eventually to use engineered genomes to make organisms that can produce clean fuels and take carbon dioxide out of the atmosphere. Publication of the research gives others the chance to scrutinise it. Some have ethical concerns. These critics have been calling for several years now for a debate on the risks of creating "artificial life" in a test tube.

But Dr Hamilton Smith, who was part of the Science study, said the team regarded its lab-made genome - a laboratory copy of the DNA used by the bacterium Mycoplasma genitalium - as a step towards synthetic, rather than artificial, life. He told BBC News: "We like to distinguish synthetic life from artificial life. "With synthetic life, we're re-designing the cell chromosomes; we're not creating a whole new artificial life system."

Dr Simon Woods, a bio-ethicist at the Policy, Ethics and Life Sciences Research Centre at the University of Newcastle, UK, said scientists were acting in a regulatory vacuum. "On the one hand it's an amazing piece of science but the real concern is that it's another example of science delving into matters that have potentially dangerous consequences," he said. "It's not necessarily going to stay in the hands of well-intentioned scientists."

The talks in Nairobi were mediated by former UN chief Kofi Annan, who said some first steps had been taken towards a peaceful solution to the crisis. Weeks of violence followed the election results, which Mr Odinga has rejected. After the talks, his party condemned a statement by Mr Kibaki in which he said he was the "duly elected president".

Meanwhile, Human Rights Watch issued a report accusing opposition officials of helping to organise ethnic violence in the Rift Valley region, in which hundreds of Mr Kibaki's Kikuyu community were deliberately targeted and killed. The unrest triggered by the election on 27 December has left more than 650 people dead and driven 250,000 from their homes.

Both men shook hands with broad smiles and expressed their commitment to peace and asked their supporters to maintain calm as they continued the newly established dialogue. "We have taken the first vital steps in resolving electoral disputes," Mr Odinga said. "I pledge to all Kenyans that my team and I will spare no effort to resolve this crisis," he added. "We are ready to walk the extra mile if that will enable Kenyans to get peace." Mr Kibaki also welcomed the talks and insisted he was committed to dialogue.

Scientists say they have been amazed by the ferocity of the gigantic flares exploding on the solar surface. The past 24 hours have seen three major events erupt over our star, hurling billions of tonnes of superhot gas into space - some of it directed at Earth. Researchers are once more predicting colourful displays of aurorae - polar lights - when the charged particles from the Sun crash into our atmosphere.

The Earth's changing magnetic field in such a storm can cause power grid and satellite problems. Japanese engineers believe that one of their satellites failed last week because of one such storm. Some experts are saying that the Sun is more active than it has been in living memory.

Dr Paal Brekke, deputy project scientist for the Solar Heliospheric Observatory (Soho) Sun-monitoring satellite, told BBC News Online: "It is quite amazing that the flaring regions continue releasing such strong flares. I think the last week will go into the history books as one of the most dramatic solar activity periods we have seen in modern times. As far as I know there has been nothing like this before." Skywatchers will be looking out for spectacular lights in the night sky.

In his message for the Catholic Church's World Communications Day, Benedict said that while the media did much good, it was also often used for ideological reasons and tried to create reality rather than report it. "When communication loses its ethical underpinning and eludes society's control, it ends up no longer taking into account the centrality and inviolable dignity of the human person," he said in the three-page message.

"For this reason it is essential that social communications should assiduously defend the person and fully respect human dignity. Many people now think there is a need, in this sphere, for 'info-ethics', just as we have bioethics in the field of medicine and in scientific research linked to life," he said. The media, he said, often risked being transformed into what he called "systems aimed at subjecting humanity to agendas dictated by the dominant interests of the day".

Under Benedict and his predecessor John Paul, the Vatican has often accused the media of promoting consumerism and elements of lifestyles that it considers unethical, such as pre-marital sex and homosexuality.
"While claiming to represent reality, it can tend to legitimise or impose distorted models of personal, family or social life," Benedict said. "Moreover, in order to attract listeners and increase the size of audiences, it does not hesitate at times to have recourse to vulgarity and violence, and to overstep the mark," he said. Proper use of the media, including the Internet, was emerging as a key challenge of the third millennium, he said.

Mr Prodi, who had led his centre-left coalition for 20 months, was defeated by five votes, despite the support of several unelected lifetime senators. President Giorgio Napolitano must now choose whether to call a snap election or appoint an interim government. Mr Prodi has been asked to continue in a caretaker capacity until then. Correspondents say the centre-right opposition alliance led by the former Prime Minister, Silvio Berlusconi, is regarded as well placed to win an early election.

La Stampa, a newspaper, said that the Holy See was trying to meddle in Italian politics. "Prodi's government dared to challenge the ecclesiastical hierarchy for the second time and this time it has had its hands burned," it said. Franco Giordano, a Communist MP, said that Mr Mastella was merely a "loudspeaker" for the Vatican, and that he had switched sides because he was told to. As Mr Mastella announced his defection on Monday, Cardinal Angelo Bagnasco, the head of the Italian Bishops Conference, attacked Mr Prodi. "The country is in pieces," he said. "There is lazy administration and a shirking of responsibility."

The bank said the fraud was based on simple transactions, but concealed by "sophisticated and varied techniques". It also announced fresh losses of 2.05bn euros related to the sub-prime mortgage crisis in the US. The losses are four times greater than those made by Nick Leeson, the rogue trader who brought down Barings Bank. Leeson was sentenced to six-and-a-half years in jail.

The bank, one of France's largest, will need to seek 5.5bn euros in new capital to offset the losses. But it said it would still make a profit of 600m to 800m euros for 2007, despite the blow to its balance sheet.

House of Representatives Speaker Nancy Pelosi said Congress would act on the deal "at the earliest date, so those rebate cheques will be in the mail". Some 117 million US homes will receive a rebate of up to $600 for individuals and up to $1,200 for married couples. Washington is moving fast to try to avoid the US falling into a recession. Couples with children will also get an extra $300 per child. The tax rebates for households should total $100bn, while businesses will benefit from up to $50bn of tax cuts.

The agreement comes two days after the Federal Reserve slashed US interest rates to 3.5% from 4.25%, its biggest cut in 25 years. Economists say the package needs to be put into action as soon as possible, before it is too late to help the economy. "I can't say that I'm totally pleased with the package, but I do know that it will help stimulate the economy," said the Democratic Party's Ms Pelosi. "But if it does not, then there will be more to come."

Some politicians are worried about the damage the plan will do to government finances. It could potentially double last year's budget deficit of $163bn. "I am concerned that in our rush to help, we talk ourselves into a quick, feel-good hit today that will leave us with a bigger budgetary hangover tomorrow," said Rep Paul Ryan of Wisconsin, the senior Republican on the House Budget Committee.

Branson, who has ambitious plans to begin carrying tourists on short flights into space by 2010, revealed models and photographs of the newest version of SpaceShipTwo and also the twin-fuselage WhiteKnightTwo which will ferry SpaceShipTwo into the atmosphere for a midair launch. Construction of the two should be completed by this year.

"2008 is really going to be the year of the spaceship," Branson, president of the Virgin Atlantic airline and a key backer of the private space flight effort, told a press conference. "The designs of both the mothership and the new spaceship are absolutely beautiful and surpass any expectations for the future of commercial spaceflight that we had when first registering the name Virgin Galactic in 1999," he said.

Branson said more than 200 passengers have confirmed their plans for the flight, which will cost 200,000 dollars each, and that some 85,000 have expressed interest. With its numerous round windows providing views on all sides, SpaceShipTwo will carry two crew and six passengers, who will experience five minutes of zero gravity once in space. The first flight is expected in 2009.

A gut-wrenching slide on global financial markets this week once again exposed centuries-old divisions between European and U.S. philosophies when it comes to coping with economic crises. European officials have taken a more patient approach so far, resisting mounting pressure to follow the U.S. Federal Reserve's aggressive lead in trying to revive the sagging economy.

In part, it reflects different economic realities of the two regions. But it also points to strong cultural differences: In the United States, there is a sense of limitless economic possibilities. In Europe, there is a stronger belief in the recurring cycle of bigger events outside anyone's control. "Americans tend to be more optimistic - everybody's got the American dream," said Jeffrey Frankel, a professor at Harvard University's Kennedy School of Government. "Europeans are more fatalistic."

While the U.S. Fed made the biggest rate cut on record, the European Central Bank stood pat. As the tighter credit conditions curbed spending in both regions, the Fed responded with an emergency interest rate cut on Tuesday, its deepest in more than two decades. The ECB still insists that euro zone growth will remain near potential, and inflation poses the greatest risk to the economy. Fed critics contend that the U.S. central bank is blissfully ignoring THE RISK THAT ITS RATE CUTS WILL REWARD WALL STREET FOR LAX LENDING, AND INEVITABLY INFLATE ANOTHER ASSET BUBBLE THAT WILL SOME DAY BURST.

Hundreds of Egyptian security personnel have moved into the area but are so far making no attempt to stem the traffic. Thousands of people streamed across the border on Wednesday to buy food and supplies after militants destroyed long stretches of the border fence. In recent days Israel had tightened its blockade on Gaza, which is run by the Islamist Hamas movement.

On Wednesday, Israeli Prime Minister Ehud Olmert said he would not let the blockade turn into a humanitarian crisis. But he said he could not allow Gazans to live normal lives while people in southern Israel were under rocket fire. Israel closed most crossing points into Gaza in June after Hamas seized control. Israel tightened the measures last week, complaining about rockets being fired from Gaza into Israeli territory.

On Wednesday, at least 50,000 Gazans packed into cars and donkey carts or crossed the Egyptian border to buy supplies, seek medical attention, or to meet family members. The BBC's Tim Franks, reporting from the region, says that within hours of the border being blasted open, the price of cigarettes had halved. Correspondents say the big question now is what happens next.

All three stock market indexes erased deep losses to end strongly ahead. The Dow Jones rose 2.5% at 12,270.17, while the Nasdaq turned around a 4% decline. The rally followed news of a plan to bail out bond insurers, which lie at the heart of the financial system. They guarantee about $2 trillion of assets. Earlier, European stocks fell. The UK's FTSE 100 was down by 3.9% at one point. Panic has swept through stock markets worldwide on fears that key global economies will enter recession.

Despite slowing economic growth on both sides of the Atlantic, the Bank of England and the European Central Bank have insisted on the need to fight inflation, making extensive rate cuts unlikely. Bank of England governor Mervyn King said that the UK faced its toughest economic challenges since 1997, when the Bank gained independence from the government. European Central Bank (ECB) President Jean-Claude Trichet told the European Parliament in a speech on Wednesday that price growth was still the ECB's main concern.

"In all circumstances, but even more particularly in demanding times of significant market correction and turbulences, it is the responsibility of the central bank to solidly anchor inflation expectations to avoid additional volatility in already highly volatile markets," he explained.

"Bank of China failed to make a statement on an important event," the Shanghai stock exchange said. According to media reports, the Bank of China may post a loss for 2007 because of its exposure to the US sub-prime mortgage sector. Meanwhile, the Shanghai Composite index followed the global trend on Tuesday and fell 7.2%, after dropping 5% on Monday, while Hong Kong shares experienced a record one-day fall of 8.7%.

Zhang Gang, an analyst at Southwest Securities, said that investors were "worried that the US credit crisis may spread into other countries. Financial stocks were hit the most, with the sentiment dampened on the expectation of a loss in the Bank of China annual report," said Shen Jun at Bank of China International.

Japan's benchmark Nikkei index closed 2.1% higher, while key share indexes climbed by more than 2% in Mumbai, Hong Kong and Sydney. The rebound came on hopes of a rescue plan for US bond insurers that could prevent a new wave of asset writedowns. The hopes had led US share prices to close higher on Wednesday, reversing falls seen earlier in the day

So far this year, the FTSE 100 has lost more than 13% of its value, wiping about £225bn off the total value of the companies listed on the index. Germany Dax's index has been one of the worst hit in Europe, down almost 20% this year.

The Amazon has long been known as the "lungs of the world". In the last five months of 2007, 3,000 sq km (1,250 sq miles) were lost. Gilberto Camara, whose National Institute of Space Research provides satellite imaging of the Amazon, said the figure was unprecedented. "We've never before detected such a high deforestation rate at this time of year," he said. His concern, outlined during a press conference in Brasilia on Wednesday, was echoed by Environment Minister Marina Silva.

The rise in deforestation will be an embarrassment for the Brazilian president, who last year said his government's efforts to control illegal logging and introduce better certification of land ownership had helped reduce forest clearance significantly. Even as he celebrated the success, though, environmentalists were warning that the rate was rising again. The situation may also be worse than reported, with the environment ministry saying the preliminary assessment of the amount of forest cleared could double as more detailed satellite images are analysed.

The nonpartisan CBO says that once the cost of wars is added to its "baseline" deficit estimate of $219 billion, the deficit would be about $250 billion. "After three years of declining budget deficits, a slowing economy this year will contribute to an increase in the deficit," the CBO report said.

Such a figure greatly exceeds the $163 billion in red ink registered last year. Including likely but still unapproved outlays for the wars in Iraq and Afghanistan, the deficit for 2008 would total about $250 billion, CBO said. Senate Budget Committee Chairman Kent Conrad, D-N.D., said the 2008 deficit would reach more than $350 billion once the costs of an upcoming economic stimulus measure under negotiation between the Bush administration and Congress are factored in.