The Republican said the city - once the birthplace of the US car industry, now groaning under $18bn (£12bn) of debt - deserves a fresh start.

Detroit has faced decades of problems linked to industrial decline.

Public services are nearing collapse and about 70,000 properties lie abandoned.

Gov Snyder said the city had filed for bankruptcy on Thursday because it was "basically broke".

"We're the comeback state in Michigan, but to be a great state we need Detroit on the path to being a great city again," he told Friday's news conference.

"Now is the opportunity to stop 60 years of decline," he added.

"We will come out with a stronger, better Detroit and a format to grow this city. The citizens of not just this city but the state deserve it."

Gov Snyder was flanked by state-appointed emergency manager Kevyn Orr, who suggested last month that the city's long-term debt could be as high as $20bn.

Mr Orr addressed concerns that art works at the Detroit Art Institute or other assets would be auctioned to pay creditors.

"Right now there's nothing for sale," he said.

Mr Orr will be allowed to liquidate city assets to satisfy creditors and pensions, if the federal court bankruptcy filing is approved.

Detroit - known as Motor City for its once-thriving automobile industry - stopped unsecured-debt payments last month to keep the city running.

Mr Orr proposed a deal in June in which creditors would accept 10 cents for every dollar they were owed. The city is currently paying 38 cents on the dollar.

But two pension funds representing retired city workers resisted the plan.

About $9bn of Detroit's debt is owed to the pension funds and retiree healthcare benefits of the city's 10,000 workers and 20,000 retirees.

Ed McNeil, the lead negotiator for a coalition of 33 unions, told Reuters news agency the move was about "busting the unions".

With tens of thousands of creditors, Detroit already faced a number of lawsuits even before it filed for bankruptcy.

These are the ghostly particles that flood the cosmos but which are extremely hard to detect and study.

Experiments have now established that one particular type, known as the muon "flavour", can flip to the electron type during flight.

The observation is noteworthy because it allows for the possibility that neutrinos and their anti-particle versions might behave differently.

If that is the case, it could be an explanation for why there is so much more matter than antimatter in the Universe.

Theorists say the counterparts would have been created in equal amounts at the Big Bang, and should have annihilated each other unless there was some significant element of asymmetry in play.

"The fact that we have matter in the Universe means there have to be laws of physics that aren't in our Standard Model, and neutrinos are one place they might be," Prof Dave Wark, of the UK's Science and Technology Facilities Council (STFC) and Oxford University, told BBC News.

The confirmation that muon flavour neutrinos can flip, or oscillate, to the electron variety comes from T2K, an international collaboration involving some 500 scientists.

The team works on a huge experimental set-up that is split across two sites separated by almost 300km.

At one end is the Japan Proton Accelerator Research Centre (J-Parc) located on the country's east coast.

It generates a beam of muon neutrinos that it fires under the ground towards the Super-Kamiokande facility on the west coast.

The Super-K, as it is sometimes called, is a tank of 50,000 tonnes of ultra-pure water surrounded by sensitive optical detectors.

These photomultiplier tubes pick up the very rare, very faint flashes of light emitted when passing neutrinos interact with the water.

In experiments in early 2011, the team saw an excess of electron neutrinos turning up at Super-K, suggesting the muon types had indeed changed flavour en route.

But just as the collaboration was about to verify its findings, the Great Tohoku Earthquake damaged key pieces of equipment and took T2K offline.

Months of repairs followed before the project was able then to gather more statistics and show the muon-electron oscillation to be a formal discovery.

Details are being reported on Friday at theEuropean Physical Society Conference on High Energy Physics in Stockholm, Sweden.

"Up until now the oscillations have always been measured by watching the types disappear and then deducing that they had turned into another type. But in this instance, we observe muon neutrinos disappearing and we observe electron neutrinos arriving - and that's a first," said Prof Alfons Weber, another British collaborator on T2K from the STFC and Oxford.

Neutrino oscillations are governed by a matrix of three angles that can be thought of as the three axes of rotation in an aeroplane - roll, pitch and yaw.

Other research has already shown two of the matrix angles to have non-zero values. T2K's work confirms that the third angle - referred to as theta-one-three - also has to have a non-zero value.

This is critical because it allows for the oscillations of normal neutrinos and their anti-particles, anti-neutrinos, to be different - that they can have enough degrees of freedom to display an asymmetrical behaviour called charge parity (CP) violation.

CP-violation has already been observed in quarks, the elementary building blocks of the protons and neutrons that make up atoms, but it is a very small effect - too small to have driven the preference for matter over anti-matter after the Big Bang.

However, if neutrinos can also display the asymmetry - and especially if it was evident in the very massive neutrinos thought to have existed in the early Universe - this might help explain the matter-antimatter conundrum. The scientists must now go and look for it.

It is likely, though, that much more powerful neutrino laboratories than even T2K will be needed to investigate the issue.

"We have the idea for a Hyper-Kamiokande which will require an upgrade of the accelerator complex," Prof Weber told BBC News.

"And in America there's something called the LBNE, which again would have bigger detectors, more sensitive detectors and more intense beams, as well as a longer baseline to allow the neutrinos to travel further."

Erratic and extreme rainfall is causing catastrophic flooding, most recently in northwest India and Nepal following heavy rainfall in June.

But the sharing of hydrological data can be a sensitive issue because of disputes over water use.

Officials say a network is required to share data across borders.

Experts and officials told the BBC that countries in the region are doing very little to help each other forecast floods.

Referring to the event last month, Chiranjibi Adhikary, chief district officer of Darchula district in western Nepal, which shares a border with India's flood-hit Uttarakhand state, said: "We received no warning from the Indian side about that devastating flood."

The flooding in the Mahakali river that criss-crosses India and Nepal claimed more than 30 lives on the Nepalese side and swept away many buildings at the district headquarters Khalanga.

Nearly 1,000 people have been confirmed dead because of the floods in the Indian side while thousands are still missing.

"We are still trying to contact them [the Indian authorities] to know what was the reason behind the floods, but there has been no telephone contact yet," Mr Adhikary told the BBC.

In western South Asia, the Kabul river that straddles Afghanistan and Pakistan was a major contributor to the massive floods in the Pakistani territory in 2010.

But, officials say, there was no communication on flood-forecasting between the two countries then, nor is there any now.

"The Kabul river is of course a flood threat to us even today but still we have no hydrological and rainfall data exchange with Afghanistan," said Mohammad Riyaj, Pakistan's chief meteorologist.

"It is something we need to do with urgency but this can be done only at the policy-making level."

One of the worst flood-hit countries in the region, Bangladesh, receives relatively little hydrological data from upstream Nepal.

Officials at Nepal's Department of Hydrology and Meteorology said they used to send the information to Dhaka by fax before but now staffing constraints have become a problem.

Pakistan does have a mechanism to receive limited hydrological data from India but officials say it is quite inadequate for meaningful flood forecasting.

"For instance, the Indian side informs the Indus Water Commission (a body under an agreement between New Delhi and Islamabad on the sharing of Indus river water) only when the water level in the Chenab river crosses 75,000 cusecs," says Mr Riyaj.

"That gives us much less time for evacuation and preparation for floods."

The Chenab is a major tributary of the Indus river that originates in Tibet and flows through India into Pakistan.

India and Pakistan have deep running disagreements on the sharing of Indus waters and have been involved in litigation.

Mr Riyaj said hydrological information on tributaries of the Chenab, including the Jhelum, Ravi and Sutlej rivers, that flow in from India would also be of great help for timely flood forecasting.

Officials in Bangladesh, however, said there had been some progress on hydrological data sharing with India as they were now getting information from three reading stations for the Ganges and four for the Bramhaputra in the Indian side.

The chief of Bangladesh's flood warning office, Amirul Hossain, said his country was also getting Bramhaputra's hydrological data from Chinese authorities in Tibet, where the river originates.

"But since our people are demanding that they should get flood warnings at least a week in advance, we would like to get the hydrological data from a bit further off areas in India so that we get more lead time for a forecast," Mr Hossain said.

Officials say the data Bangladesh gets from India at present are from nearby border areas.

Hydrological data is quite a sensitive issue in India, especially between states that have been at loggerheads over the sharing of water resources for quite some time.

The recent order by India's water resources ministry to its authorities regarding the constitution of the "classified data release committee" read: "The committee shall consider requests for release of classified data after due verification by the concerned chief engineer of the Central Water Commission and [the] receipt of [a] secrecy undertaking."

Rajendra Sharma, who heads Nepal's flood forecasting division at the country's meteorological office, said: "For genuine regional flood forecasting, all countries including India and China will have to actively participate in the exchange of hydrological and meteorological data."

Indian officials said they recognised the importance of cross border cooperation for effective flood forecasting.

Though he was optimistic that things could improve in future, M Shashidhar Reddy, vice chairman of India's National Disaster Management Authority, said: "Things which are on paper sometimes do not get translated into action."

The Cassini probe, in orbit around the gas giant, is going to take a picture of Earth, and the imaging team wants everyone to wave and smile.

Because of the great distance to Saturn, our home will appear as a mere pixel in the final photo.

But Cassini scientist Carolyn Porco says it is a moment to "celebrate life on the Pale Blue Dot".

"Waving time" - the period when the spacecraft's cameras will be operating - starts at 21:27 GMT and ends at 21:42 GMT (22:27-22:42 BST).

These timings include the 80 minutes it will take reflected light from the surface of the Earth to travel the nearly 1.5 billion km (900 million miles) to reach the outer Solar System.

Dr Porco's Ciclops imaging team will be producing a large mosaic of Saturn and its ring system on Friday.

Earth will appear as small speck in the lower-right of the final picture.

It is likely to be several days before the first images are processed and released.

The probe snapped a similar mosaic in 2006. On that occasion, Earth was positioned in the upper-left of the frame.

But Dr Porco says the set-up six years ago was not ideal. For the re-shoot, she plans to use Cassini's highest resolution camera, and the most appropriate filters to capture Earth in natural colour.

More than that, however, she says, people on Earth will know this time they are on camera, and that offers everyone the opportunity to participate.

Dr Porco hopes the picture will be reminiscent of the famous "Pale Blue Dot" image captured by the Voyager-1 probe in 1990.

That was a picture she helped organise with the astronomer and popular science writer Carl Sagan.

He memorably described the Earth as looking like a "mote of dust suspended in a sunbeam", such was its apparent insignificance in the vastness of space.

Inspired in part by the Cassini team's plans, scientists working on the Messenger probe at Mercury will also be picturing Earth on Friday and Saturday.

Messenger will see Earth as it scans the skies for any previously unrecognised objects that might be circling the innermost world.

Timings for these pictures are 11:49, 12:38, and 13:41 (all GMT) on both Friday and Saturday.

Parts of the Earth not illuminated in the Cassini images, including all of Europe, the Middle East and Central Asia, will appear illuminated in the Messenger pictures.

More details on the Saturn project can be found at The Day The Earth Smiled website.

The companies want to be able to report regular statistics about the nature and scope of what data is being asked for.

Whistle-blower Edward Snowden's revelations about US spying capabilities has left the tech firms keen to assert their independence.

Authorities are said to be considering the companies' request.

"We just want to make sure we do it right," said Gen Keith Alexander, director of the National Security Agency.

"We don't impact anything ongoing with the FBI. I think that's the reasonable approach."

The companies sent a letter outlining their request on Thursday to Gen Alexander, as well as President Obama and Congress.

It was co-signed by some of the most influential companies in the tech world, including Facebook, Twitter and LinkedIn.

Campaign groups such as the Electronic Frontier Foundation and Human Rights Watch are also backing the action.

Companies are currently allowed to release limited data regarding security requests and their nature.

But as it stands those disclosures must be limited in scope, and in many cases require that the firms ask the courts for permission to make the information public.

Many users of popular services, particularly social networks, reacted angrily to the news that companies regularly make available information about users when requested to do so.

"They don't have a choice. Court order, they have to do this," Mr Alexander from the NSA said, suggesting that security authorities could be open to the idea.

"What they want is the rest of the world to know that we're not reading all of that email, so they want to give out the numbers.

"I think there's some logic in doing that."

It has launched a plan to update and co-ordinate national tax laws.

There was criticism in the UK earlier this year when it emerged that Google, Starbucks and Amazon paid little tax despite having big UK operations.

Following that criticism Starbucks agreed to pay more tax.

The OECD came up with the plan at the request of the G20 group of leading nations. Finance ministers from the G20 are meeting in Moscow.

OECD secretary-general Angel Gurria said: "International tax rules, many of them dating from the 1920s, ensure that businesses don't pay taxes in two countries - double taxation.

"This is laudable, but unfortunately these rules are now being abused to permit double non-taxation."

It is calling for greater international co-operation to close gaps that allows income to "disappear" for tax purposes.

The OECD also said that tax income should reflect the economic activity it generates.

That would address some of the criticism aimed at big companies.

Earlier this year, Google was fiercely criticised by UK MPs for routing £3.2bn of UK sales through Dublin and paying little tax as a result.

Starbucks has been questioned for transferring money to a Dutch sister company in royalty payments.

And Apple's chief executive Tim Cook was questioned by US lawmakers about the billions of dollars his company keeps in its Irish divisions.

The companies point out that these schemes are legal and they have a duty to their shareholders to minimise their tax bills.

Corporate responsibility

British Prime Minister David Cameron said he was "delighted" the OECD had produced the report.

"Taxpayers, governments and businesses all suffer when some companies manipulate the tax system to avoid paying their fair share of taxes," he said.

The OECD hopes its recommendations will be put into action over the next two years and is working on an international legal structure that would help countries introduce the new rules quickly.

"Multinationals still have not grasped that tax honesty is an integral part of corporate responsibility," said Florian Wettstein, professor of business ethics at the University of St. Gallen, based in Switzerland.

"As a result, the public increasingly perceives them as hypocritical and untrustworthy."

Campaigners say that aggressive tax policies are particularly hard on poorer nations, who need all the tax revenue they can generate.

ActionAid tax campaigns manager Chris Jordan said: "For the developing countries that lose billions of dollars each year to aggressive tax avoidance, the stakes couldn't be higher.

"It's vital that they have a seat at the table, so global tax rules aren't stitched up by the major powers."

More than 1,000 people protested outside the governing Popular Party (PP) headquarters in the capital.

There is widespread anger over allegations of illegal cash payments to members of the conservative PP.

Prime Minister Mariano Rajoy is under pressure to give an explanation to parliament. He denies wrongdoing.

The demonstrations on Thursday night caused disruption to traffic in central Madrid.

Protesters held placards calling on the government to resign. There was also a protest outside the PP offices in Valencia.

The corruption allegations coincide with Spain's worst economic crisis for decades, with record unemployment and many Spaniards struggling to make ends meet.

The PP's former treasurer, Luis Barcenas, is in custody facing trial for corruption and tax fraud. He denies the allegations.

He says he made numerous bonus payments - in cash - to Mr Rajoy and other senior party members, out of the party slush fund of illegal donations by businesses.

Ledgers detailing such payments, and apparently written by Mr Barcenas, have been published in two Spanish newspapers - El Pais and El Mundo.

Mr Rajoy and other PP members have repeatedly denied that they received illegal payments.

The prime minister has accused Mr Barcenas of blackmail.

For now at least there is no sign that Mr Rajoy might resign over the scandal, the BBC's Tom Burridge reports from Madrid. The PP has a comfortable majority in parliament.