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Tuesday, September 2, 2008

Strange Clouds Spotted at the Edge of Space


A weirdly wonderful sight appeared to astronauts aboard the International Space Station this summer — thin blue clouds hovering at the boundary between Earth's atmosphere and the void.

The noctilucent or "night-shining" clouds are at an altitude of 47 to 53 miles (76 to 85 km), where meteors and bright aurora lights are not uncommon and the atmosphere gives way to the blackness of space. The clouds remain a scientifically baffling phenomenon more than 120 years after their discovery.

"It's lovely," said Gary Thomas, an atmospheric scientist at the University of Colorado after looking at a photo taken from the space station. "And it shows just how high these clouds really are – at the very edge of space."

The clouds form at dizzying heights where the air is one hundred million times drier than the Sahara. By contrast, the common high-altitude cirrus clouds only reach heights of 11 miles (18 km) up.

"We have a fairly good idea that the water vapor from below gets transported upwards," Thomas told SPACE.com. "That is in essence the fuel."

Part of that water vapor comes from rising air in the tropics, where a few parts per million of water escape into farthest reaches of the upper atmosphere. Another likely source of water vapor is methane oxidation. Methane concentrations have more than doubled over the past 100 years, which could explain part of the changes in the high-flying clouds over the past decades.

People first spotted the noctilucent clouds a few years after the 1883 eruption of the Krakatoa super-volcano in Indonesia created spectacular sunsets from ash in the atmosphere. Robert Leslie of Southampton, England saw the clouds one evening in July 1885 and published the first observations in the journal Nature.

The clouds have since spread from the northern latitude regions such as Scandinavia, Scotland and Siberia to areas farther south. Sightings have cropped up in Washington and Oregon in the United States, as well as in Turkey and Iran.

Scientists can observe widespread instances of the clouds throughout the polar summer. Some clouds even formed after the fateful launch of the doomed space shuttle Columbia, when 400 tons of water from the shuttle exhaust drifted toward the South Pole.

The mystery only thickened after the launch of a satellite dubbed Aeronomy of Ice in the Mesosphere (AIM) in 2007, when AIM spotted a type of "stealth" noctilucent cloud made of smaller ice crystals less than 30 nanometers (a red blood cell is about 10,000 nanometers). Such clouds appear to stay in the upper atmosphere all the time.

"They're just so tiny that they don't scatter light efficiently," Thomas said.

AIM has also found a strong resemblance between the noctilucent clouds and tropospheric clouds that hover near Earth's surface, which suggests that the dynamics of near-space weather may not be incredibly strange after all.

Researchers speculate that the origin and spread of the clouds is linked to patterns of climate change associated with the modern era. But they are not ruling out a host of other possible factors, including methane, carbon dioxide, the number of meteors seeding the upper atmosphere, and even the 11-year sunspot cycle.

"I think the jury's still out on that," Thomas said. "We're just trying to understand now how clouds form and how they vary."

Human geography is mapped in the genes

The genes of a European person can be enough to pinpoint their ancestry down to their home country, claim two new studies.

By reading single-letter DNA differences in the genomes of thousands of Europeans, researchers can tell a Finn from a Dane and a German from a Brit. In fact a visual genetic map mirrors the geopolitical map of the continent, right down to Italy's boot.

"It tells us that geography matters," says John Novembre, a population geneticist at the University of California, Los Angeles, who led one of the studies. Despite language, immigration and intermarriage, genetic differences between Europeans are almost entirely related to where they were born.

This, however, does not mean that the citizens of each European nation represent miniature races. "The genetic diversity in Europe is very low. There isn't really much," says Manfred Kayser, a geneticist at Erasmus University Rotterdam in the Netherlands, who led the other study.

One-letter differences

Kayser's and Novembre's teams uncovered the gene-geography pattern only by analysing hundreds of thousands of common gene variants called single nucleotide polymorphisms (SNPs) across the genomes of people from about two dozen countries. SNPs are places in the genome where one person's DNA might read A, while another's T.

Though the teams worked independently, they used some of the same DNA samples, which were gathered by the pharmaceutical company GlaxoSmithKline to help hunt for genes linked to drug side effects. The researchers recorded the results alongside the country of origin for each subject as well as that of their parents and grandparents when possible.

For each subject, the researchers decoded half a million SNPs. However, to get an overall assessment of the difference between any two genomes, the researchers used a mathematical trick that scrunched the hundreds of thousands of SNPs into two coordinates, with each person's genome represented by a point. The greater the distance between two points, the greater the difference in their genomes.

When both teams plotted thousands of genomes on a single graph along with their country of origin, a striking map of Europe emerged. Spanish and Portuguese genomes clustered "south-west" of French genomes, while Italian genomes jutted "south-east" of Swiss.

These cardinal directions are artificial, but the spatial relationships between genomes are not. In general, the closer together two people live, the more similar their DNA. The same is known to be true of animals .

Predicting origins

The map was so accurate that when Novembre's team placed a geopolitical map over their genetic "map", half of the genomes landed within 310 kilometres of their country of origin, while 90% fell within 700 km.

Both teams found that southern Europeans boast more overall genetic diversity than Scandinavians, British and Irish.

"That makes perfect sense with the major migration waves that went into Europe," says Kayser, noting Homo sapien's European debut 35,000 years ago, post-ice age expansions 20,000 years ago, and movements propelled by the advent of farming 10,000 years ago. In each case, members of established southern populations struck north.

"A pattern in which genes mirror geography is essentially what you would expect from a history in which people moved slowly and mated mainly with their close neighbours," says Noah Rosenberg, a geneticist at the University of Michigan in Ann Arbor.

Bodies found in the tomb of 'boy king' Tutankhamun's tomb are twin daughters

Two foetuses found buried with Tutankhamun may have been his twin daughters, an expert has claimed.

Professor Robert Connolly, an anatomist who is working with Egyptian authorities to analyse the tomb of the Egyptian Pharaoh, says that preliminary tests on the mummified remains of the two still-born babies indicate that Tutankhamun may have fathered them both. He will present the new findings at the Pharmacy and Medicine in Ancient Egypt Conference at the University of Manchester today.

Professor Connolly, who first studied the remains of Tutankhamun in the Sixties, said: “The two foetuses in the tomb of Tutankhamun could be twins, despite their very different size and thus fit better as a single pregnancy for his young wife [Ankhesenamun]. This increases the likelihood of them being Tutankhamun's children.”

“I studied one of the mummies, the larger one, back in 1979, determined the blood group data from this baby mummy and compared it with my 1969 blood grouping of Tutankhamun. The results confirmed that this larger foetus could indeed be the daughter of Tutankhamun.

“Now we believe that they are twins and they were both his children.”

Professor Connolly, a physical anthropologist at the University of Liverpool, said: “It is a very exciting finding which will not only paint a more detailed picture of this famous young king's life and death, it will also tell us more about his lineage.”

The foetuses have been stored at the Faculty of Medicine in Cairo University since the archaeologist Howard Carter discovered them in the teenage king's tomb on the west bank of Luxor in 1922. Egyptologists have long debated whether they were his children or if they were placed in the tomb with the symbolic purpose of allowing the famous pharaoh to live on as newborns in the afterlife.

The answer to this hereditary puzzle is closer because the two foetuses are to undergo CT scans and DNA testing to determine possible diseases and their relation to Tutankhamun. The smaller foetus is about five months in gestational age and the larger foetus is estimated to be between seven and nine months. The results of the remaining tests are due in December.

“We are very proud to have Professor Connolly speaking at the conference and are extremely excited about his new findings,” said the conference director Rosalie David, of the University of Manchester's Faculty of Life Sciences.

“Tutankhamun is such an important figure in Egyptology. He was a fascinating character whose tomb and indeed body has given us so much information about life in Ancient Egypt, and it seems that he will continue to do so for some time yet.”

More than 100 delegates from ten countries will be attending the conference. It intends to bring together the two elements of Ancient Egyptian healthcare practices — pharmacy and medicine

The Future of Beijing's Cleaner Air

Most of the history that happened in Beijing over the past few weeks took place in gyms, in the pool and on the track. But there was also history in the air, specifically the best summer air quality this city has seen in 10 years. So as the Olympic experience fades into memory, the question remains whether the Chinese capital can keep that clean air from fading as well.

Several measures and some $17 billion were used to get pollution under control in time for the Olympics. But the step that most directly affected Beijing residents was the program for talking half of the city’s 3.3 million cars off the road each day. Cars with odd-numbered plates were limited to driving on odd numbered dates, and even plates to even dates. After seeing how beautiful this city can be with clean skies, some are asking why can’t such the plan, which ends Sept. 20, be made permanent. The state-run Xinhua News Service reported that more than 400,000 people have “joined an online discussion” about the future of the car ban. In a survey on Xinhua’s website, more than half the respondents indicated they’d support permanent restrictions. Web surveys are notoriously unreliable, but the results at least indicate some support for further steps to improve Beijing’s air.

Which is good news, but the support is misdirected. The car restrictions were helpful for Beijing’s Olympic cleanup, but at best they were a temporary measure. While car owners were willing to endure great inconvenience to put on a good show for the Olympics, their tolerance is unlikely to last beyond September. And an odd-even plan would probably lose effectiveness in the long run. In Mexico City, which started once-a-week restrictions in 1989, studies have shown that the program had no affect on air pollution in the long run because residents bought new cars and held onto old ones to ensure they always had a vehicle to drive. TIME’s Beijing bureau offers a similar example. Our junky old Jeep, which rarely saw the road since we bought a new vehicle a couple years ago, got regular mileage during the Olympic period because it has odd-numbered plates and our regular ride has even.

But in all the discussion of the car ban there are some positive signs. People care about Beijing’s air quality and are looking for ways to improve it. While continuing the car ban isn’t a long-term fix, it might not be so hard to get people behind further improving mass transit, which unlike a car ban could actually make getting around easier.

In New Orleans, blogs become crucial decision-making tool

The fearful weather reports about Hurricane Gustav did not persuade Sheila Moragas to leave Old Jefferson, a suburb just west of New Orleans. It was the 38-year-old mother's dwindling ranks of online friends on the micro-blogging network Twitter.

One by one, Twitterers with nicknames like "HumidCity," "DomesticKitty" and "NOLADawn" pulled up stakes Sunday and left south Louisiana, live-blogging the building drama through text messages on their laptops, home computers and cell phones.

"It's been helpful," Moragas said. "It's less hyperbole, more reliable. There's also a lot of people panicking, but it's neighborly. It feels like you're talking to your next-door neighbors and trying to say, 'What's the best thing to do?' "

At noon Sunday, Moragas, known as "NOLAnotes" to her followers on Twitter, decided the wisest option was to leave, abandoning the New Orleans area in advance of a massive hurricane for the second time in three years.
"Baton Rouge. Final answer. Locked in," she declared online. "Finalizing our packing and then hitting the road." She vowed to deliver a blow-by-blow account on her blog.

Across a largely empty New Orleans, bloggers and online social networkers struggled with the question of whether they should leave or stay and ride out the storm while communicating—in real time—to friends and the world at large. Hundreds of new viewers signed on to Twitter to join the conversation.

"Look at this little thing," said Karen Gadbois, 53, a New Orleans blogger, referring to Twitter. "You can jump on it and jump off it. It's not a lifetime commitment. It's very useful."

Bloggers said their fascination with the possibilities of using online networks to track the storm and help others was fueled by new technology available to them as well as lingering frustration over the response to Hurricane Katrina three years ago.

Kali Akuno, an education and training coordinator with the U.S. Human Rights Network, was part of a group along the Gulf Coast reaching out to African-American bloggers to help resettle hundreds of people displaced as they evacuated ahead of Hurricane Gustav.

Online followers as far away as Oregon, Washington and Rhode Island extended offers of hospitality, Akuno said. The group had already placed 150 people, and was looking to find shelter for 200 more who contacted it in New Orleans.

"People are definitely responding," Akuno said. "The main thing we learned from three years ago was the importance of staying in contact with each other."

If nothing else, the contact has provided an emotional touchstone for a population in exodus.

"Safely in Bossier," twittered Matt Langford of Lafayette, La., known as Matt425. "Now we wait."

"In my pocket: $67.42 and my lucky scarab + king cake baby," John D'Addario (jonnodotcom) of New Orleans noted on Twitter as he fled to Alabama. His St. Joseph medal got lost in transit, he added.

Not everyone fled.

Mark Mayhew, 45, decided to ride out Hurricane Gustav in his third-floor cubbyhole on Bourbon Street.

He has armed himself with canned tuna fish, corn flakes, a case of beer and an IBM Think Pad covered in cigarette ashes. The looming hurricane has crystallized the importance of community, he said. Even if it's online.

Among Bourbon Street's transient population, Mayhew says he has met few people on his street since moving to town six weeks after Katrina left.

"Since the evacuation, I've met all of them," he said. "Are you going to stay or are you going to go? Because if you're staying, we need to talk."

Massive floating generators, or 'eco-rigs', to provide power and food to Japan

Battered by soaring energy costs and aghast at dwindling fish stocks, Japanese scientists think they have found the answer: filling the seas with giant “eco-rigs” as powerful as nuclear power stations.

The project, which could result in village-sized platforms peppering the Japanese coastline within a decade, reflects a growing panic in the country over how it will meet its future resource needs.

The floating eco-rig generators which measure 1.2 miles by 0.5 miles (2km by 800m) are intended to harness the energy of the Sun and wind. They are each expected to produce about 300 megawatt hours of power.

Some energy would be lost moving the electricity back onshore, but when three units are strapped together, scientists at Kyushu University say, the effect will be the same as a standard nuclear power station.

The eco-rigs' gift to the environment does not stop there: some of the power that the solar cells and wind turbines produce will be hived off to fuel colossal underwater banks of light-emitting diodes (LEDs).

The lamps are intended to convert the platforms into nurseries for specially selected seaweed that absorbs carbon dioxide and feeds fish and plankton. Deep-sea water that is rich in minerals will enhance the seaweed growth. The wind turbines will power pumps that will then draw the water to the surface.The rigs will be unmanned and comprise several hexagonal platforms.

Strapped between them will be large nets designed to support the weight of wind turbines and about 200,000 hexagonal photovoltaic generators — super-efficient solar panels that are about the size of a double bed. The LEDs will shine down from the panels.

As a country with virtually no fossil fuels, price rises in oil and gas have chilled the corporate sector and the Japanese Government.

Japan's faith in nuclear power has also taken a beating. An earthquake caused its largest nuclear plant to shut down in 2007 and engineers and seismic experts cautioned that the country's high susceptibility to quakes placed the industry at risk.

The Kyushu team says the plans are about three years away from becoming reality. It began tests on a scale version of the eco-rig last month, and full-scale official evaluation is expected to begin soon.