Friday, 14 September 2007
The US chief scientist has told the BBC that climate change is now a fact.
Professor John Marburger, who advises President Bush, said it was more than 90% certain that greenhouse gas emissions from mankind are to blame.
The Earth may become "unliveable" without cuts in CO2 output, he said, but he labelled targets for curbing temperature rise as "arbitrary".
His comments come shortly before major meetings on climate change at the UN and the Washington White House.
There may still be some members of the White House team who are not completely convinced about climate change - but it is clear that the science advisor to the President and director of the Office of Science and Technology Policy is not one of them.
In the starkest warning from the White House so far about the dangers ahead, Professor Marburger told the BBC that climate change was unequivocal, with mankind more than 90% likely to blame.
Despite disagreement on the details of climate science, he said: "I think there is widespread agreement on certain basics, and one of the most important is that we are producing far more CO2 from fossil fuels than we ought to be.
"And it's going to lead to trouble unless we can begin to reduce the amount of fossil fuels we are burning and using in our economies."
Trouble ahead
This is an explicit endorsement of the latest major review of climate science from the Intergovernmental Panel on Climate Change (IPCC).
Professor Marburger said humanity would be in trouble if we did not stop increasing carbon emissions. 
"The CO2 accumulates in the atmosphere and there's no end point, it just gets hotter and hotter, and so at some point it becomes unliveable," he said.
Professor Marburger said he wished he could stop US emissions right away, but that was obviously not possible.
US backing for the scientific consensus was confirmed by President Bush's top climate advisor, James Connaughton.
The chair of the White House Council on Environmental Quality told BBC News that advancing technology was the best way to curb the warming trend.
"You only have two choices; you either have advanced technologies and get them into the marketplace, or you shut down your economies and put people out of work," he said.
"I don't know of any politician that favours shutting down economies."
'Arbitrary' targets
Mr Bush has invited leaders of major developed and developing nations to the White House later this month for discussions on a future global direction on climate change.
It will follow a UN General Assembly session on the same issue.
Last week the Asia-Pacific Economic Co-operation forum in Sydney backed the UN climate convention as the right body for developing future global policy.
The European Union wants such a policy to adopt its own target of stabilising temperature rise at or below 2C.
But Mr Marburger said the state of the science made it difficult to justify any particular target.
"It's not clear that we'll be in a position to predict the future accurately enough to make policy confidently for a long time," he said.
"I think 2C is rather arbitrary, and it's not clear to me that the answer shouldn't be 3C or more or less. It's a hunch, a guess."
The truth, he said, was that we just do not know what the 'safe' limit is.
By Roger Harrabin
Bush aide says warming man-made
Neanderthal climate link debated
Thursday, 13 September 2007
The theory that an abrupt, catastrophic change in the climate extinguished the last Neanderthals is challenged in the journal Nature.
Our evolutionary cousins went extinct in most of Europe about 35,000 years ago, but small pockets survived much later than this in southern Iberia.
The cause of these ancient humans' demise is hotly debated and a variety of theories have been put forward.
However, other researchers question the study's conclusions.
Neanderthals (Homo neanderthalensis) first appear in the fossil record about 230,000 years ago and, at their peak, ranged across Europe and parts of western Asia.
Competition with modern humans (Homo sapiens) - who arrived on the European continent about 40,000 years ago - as well as climate change, have long been discussed as culprits for the Neanderthals' extinction across much of their former range 35,000 years ago.
But pockets of these ancient humans appear to have survived in southern Iberia until much more recently than they did elsewhere - perhaps until 24,000 years ago.
Climate change is proposed to have played an important role in this local extinction. A study published earlier this year suggested a sudden cold snap about 24,000 years ago was implicated in the Neanderthals' disappearance from their Iberian refuge.
In the new research, an international team turned to a site at Gibraltar called Gorham's Cave.
Radiocarbon dating of material form that cave has suggested the Neanderthals may have died out between 32,000 to 24,000 years ago.
Costa del Neanderthal
The researchers mapped three radiocarbon dates spanning this period - 32,000, 28,000 and 24,000 years ago - on to a well-dated palaeoclimate archive based on deep-sea cores drilled in Venezuela. The archive relates records of past climate to radiocarbon dates.
They discovered that 32,000 and 28,000 radiocarbon years ago, Europe was experiencing conditions similar to the general climatic instability of the previous glacial period - conditions the Neanderthals had already proven able to survive.
Professor Katerina Harvati, an author of the paper and a palaeoanthroplogist from the Max Planck Institute for Evolutionary Biology, Germany, said: "The more controversial date of circa 24,000 years ago, places the last Neanderthals just before a major climate shift that would have been characterised by a large expansion of ice sheets and the onset of cold conditions in northern Europe.
"But Gibraltar's climate would have remained relatively unaffected, perhaps as a result of warm water from the sub-tropical Atlantic entering the western Mediterranean."
Speaking at the BA festival in York, she concluded: "Our findings suggest that there was not a single abrupt climatic event that caused the extinction of the Neanderthals."
Professor Harvati added: "This eliminates catastrophic climate change as a cause for extinction, but this leaves a whole range of other possibilities."
Late survivors
Professor Clive Finlayson is director of the Gibraltar Museum and co-authored the paper proposing a link between the sudden cold snap and the extinction of Neanderthals in southern Iberia.
Although he said he welcomed the interest in Gorham's Cave, he also saw several problems with the conclusions of the latest study. Firstly, he said, it was "strange" to try to link climatic events in the Caribbean with ones in Europe.
"I think they've missed the point," he told the BBC News website, "those dates, 32,000, 28,000 and 24,000 years ago, are occupation dates. They're dates when there are enough Neanderthals around for them to be picked up in the archaeological record.
"Whichever of those three dates you choose, populations would have gone extinct after that. They are trying to match this event with a time when Neanderthals were still around and are doing alright - within the limits of being a late population.
"This climatic event, which they say is 3,000 years later than our occupation date at 24,000 years ago, coincides perfectly with a period of no Neanderthals and no modern people in Gorham's Cave. That was music to my ears."
In their Nature paper, Professor Harvati and her colleagues contend that if the Neanderthals did die out at the later date of 24,000 years ago, climate changes in the north might have pushed modern humans further south into the Neanderthals' territory - forcing them into competition for scarce resources.
But Professor Finlayson explained there was no evidence for a southward human migration at this time. He said there was only one site in southern Spain with evidence for modern human occupation at the same time as Neanderthals were in the region - and even that one was disputed.
The next evidence for modern humans in southern Iberia comes several thousand years after the last evidence for Neanderthals at Gorham's Cave. 
UK science head backs ethics code
Wednesday, 12 September 2007
The British government's chief scientific advisor has set out a universal ethical code for scientists.
Professor Sir David King has outlined seven principles aimed at building trust between scientists and society.
Described as the scientific equivalent of doctors' Hippocratic Oath, the code includes clauses on corruption, public consultation and the environment.
He launched the code at the British Association for the Advancement of Science's annual festival in York.
The aim, he said, was to outline responsibilities and values in order to encourage researchers to reflect on the impact their work would have on wider society.
"We believe if every scientist followed the code, we would improve the quality of science and remove many of the concerns society has about research," Professor King told BBC News.
Code endorsed
The scientific profession generally has high standards of integrity, and many scientists have a social conscience, according to Professor King. But there is no formal code of ethics.
"It's important to look at the relationship between science and the public," he said.
"If we have a breakthrough, and society is not accepting of that, then we have a problem; so what we need is for scientists to accept the code and follow it".
The code has been adopted by scientists working in the UK government - and Professor King has invited researchers in UK universities and industry to join them. Next year it will be launched internationally.
The idea was swiftly backed by Lib Dem science spokesman Dr Evan Harris.
"The seven points in this code are part of what separates researchers from charlatans, medicine from quackery and science from supposition," he said.
"It deserves the full support of the science world and policy-makers from the UN down to university governing bodies and company boards."
The Royal Society of Chemistry also approved, issuing a statement saying: "We are proud that all of our 44,000 members across the world, including Sir David King himself, have already signed up to such a code and subject themselves to independent regulation and scrutiny of their professional duties."
Professor King conceded that the code could create conflicts between employers and indviduals, but suggested it could also help resolve them.
"Place yourself in the position of a scientist who works for a tobacco company, and the company asks you to counter evidence about the health impacts of tobacco.
"That scientist would be able to look at the code and say 'I can't do that'."
Mars rover dips over crater edge
Wednesday, 12 September 2007
Nasa's Mars rover Opportunity has begun its assault on Victoria Crater.
The vehicle drove just far enough to get all six wheels past the bowl's rim, and then backed up three metres (10ft).
Data returned to Earth will help engineers assess how much grip the robot will have when it makes its full descent into the impact crater.
The 60m-deep (200ft) depression has exposed faces of layered rock that could shed significant new light on the Red Planet's geological past.
Victoria Crater is about five times wider than Endurance Crater, which Opportunity spent six months exploring in 2004, and about 40 times wider than Eagle Crater, where the rover first landed.
Opportunity's first venture in Victoria Crater was described as a "toe dip".
Data suggested the rover experienced a fair degree of slippage on the retreat manoeuvre, and came to rest with its front wheels lodged over a sand ripple near the top of the crater lip. 
"We will do a full assessment of what we learned from the drive today and use that information to plan Opportunity's descent into the crater," said John Callas, rover project manager at Nasa's Jet Propulsion Laboratory, Pasadena in California.
The rover team is concerned not to rush the descent, aware that the vehicle could get stuck or even topple over.
The US space agency's (Nasa) second rover, Spirit, is on the other side of the Red Planet in a near-equatorial position. It is studying a plateau called Home Plate in the Gusev Crater region.
Huge dust storms on Mars have hampered the work of both vehicles recently. Engineers put the robots on a minimal workload for over a month as their solar panels struggled to generate power under opaque skies. 
Gorillas head race to extinction
Wednesday, 12 September 2007
Gorillas, orangutans, and corals are among the plants and animals which are sliding closer to extinction.
The Red List of Threatened Species for 2007 names habitat loss, hunting and climate change among the causes.
The World Conservation Union (IUCN) has identified more than 16,000 species threatened with extinction, while prospects have brightened for only one.
The IUCN says there is a lack of political will to tackle the global erosion of nature.
Governments have pledged to stem the loss of species by 2010; but it does not appear to be happening.
"This year's Red List shows that the invaluable efforts made so far to protect species are not enough," said the organisation's director-general, Julia Marton-Lefevre.
"The rate of biodiversity loss is increasing, and we need to act now to significantly reduce it and stave off this global extinction crisis."
One in three amphibians, one in four mammals, one in eight birds and 70% of plants so far assessed are believed to be at risk of extinction, with human alteration of their habitat the single biggest cause.
Critical list
The tone of this year's Red List is depressingly familiar. Of 41,415 species assessed, 16,306 are threatened with extinction to a greater or lesser degree.
The main changes from previous assessments include some of the natural world's iconic animals, such as the western lowland gorilla, which moves from the Endangered to the Critically Endangered category.
Numbers have declined by more than 60% over the last 20-25 years.
Forest clearance has allowed hunters access to previously inaccessible areas; and the Ebola virus has followed, wiping out one-third of the total gorilla population in protected areas, and up to 95% in some regions.
Ebola has moved through the western lowland gorilla's rangelands in western central Africa from the southwest to the northeast. If it continues its march, it will reach all the remaining populations within a decade.
The Sumatran orangutan was already Critically Endangered before this assessment, with numbers having fallen by 80% in the last 75 years.
But IUCN has identified new threats to the 7,300 individuals that remain. Forests are being cleared for palm oil plantations, and habitat is being split up by the building of new roads.
In Borneo, home to the second orangutan species, palm oil plantations have expanded 10-fold in a decade, and now take up 27,000 sq km of the island. Illegal logging reduces habitat still further, while another threat comes from hunting for food and the illegal international pet trade.
So fragmented have some parts of the Bornean forest become that some isolated orangutan populations now number less than 50 individuals, which IUCN notes are "apparently not viable in the long term".
Straight to zero
The great apes are perhaps the most charismatic creatures on this year's Red List, but the fact they are in trouble has been known for some years. Perhaps more surprising are some of the new additions.
"This is the first time we've assessed corals, and it's a bit worrying because some of them moved straight from being not assessed to being possibly extinct," said Jean-Christophe Vie, deputy head of IUCN's species programme. 
"We know that some species were there in years gone by, but now when we do the assessment they are not there. And corals are like the trees in the forest; they build the ecosystem for fish and other animals."
IUCN is now embarking on a complete assessment of coral species, and expects to find that about 30% to 40% are threatened.
The most glaring example of a waterborne creature failed by conservation efforts is probably the baiji, the Yangtze river dolphin, which is categorised as Critically Endangered, Possibly Extinct.
This freshwater species appears to have failed in its bid for survival against the destructive tides of fishing, shipping, pollution, and habitat change in its one native river. Chinese media reported a possible sighting earlier this year, but the IUCN is not convinced; with no confirmed evidence of a living baiji since 2002, they believe its time on Earth may well be over.
If so, it will have become a largely accidental victim of the various forces of human development. Not so the spectacular Banggai cardinalfish; a single decade of hunting for the aquarium trade has brought numbers down by an astonishing 90%. 
Many African vultures are new entrants on this year's list. But birds provide the only notable success, with the colourful Mauritius echo parakeet making it back from Critically Endangered to Endangered.
Intensive conservation work has brought numbers up from about 50 to above 300.
But the gharial, a crocodilian found in the major rivers of India and Nepal, provides a cautionary tale of what can happen when conservation money and effort dry up.
A decade ago, a programme of re-introduction to the wild brought the adult population up from about 180 to nearer 430. Deemed a success, the programme was stopped; numbers are again hovering around 180, and the gharial finds itself once more on the Critically Endangered list.
Climate of distraction
IUCN says that it is not too late for many of these species; that they can be brought back from the brink.
It is something that the world's governments have committed to, vowing in the 1992 Convention on Biological Diversity "to achieve by 2010 a significant reduction of the current rate of biodiversity loss at the global, regional and national level". 
"Governments know they are going to fail to reach that target," said Jean-Christophe Vie, "and not just in terms of a few species - the failure is really massive.
"We know that it is possible to reverse the trend, but the causes are so huge and massive and global, and there is still a lack of attention to the crisis that biodiversity faces."
Many in the environmental movement argue that too much money and attention has gone on climate change, with other issues such as biodiversity, clean water and desertification ignored at the political level.
IUCN's assessment is that climate change is important for many Red List species; but it is not the only threat, and not the most important threat.
There are conflicts between addressing the various issues, with biofuels perhaps being the obvious example. Useful they may turn out to be in reducing greenhouse gas emissions; but many conservationists are seriously concerned that the vast swathes of monoculture they will bring spell dire consequences for creatures such as the orangutan.
Godwit makes huge Pacific flight
Tuesday, 11 September 2007
It's official - the godwit makes the longest non-stop migratory flight in the world.
A bird has been tracked from its Southern Hemisphere summertime home in New Zealand to its breeding ground in Alaska - and back again.
The bar-tailed godwit, a female known as E7, landed in New Zealand this past weekend after taking a week to fly 11,500km from Alaska to New Zealand.
Unlike seabirds, which feed and rest on long journeys, godwits just keep going.
The migrant champion was one of 13 satellite-tagged bar-tails (Limosa lapponica baueri) that left New Zealand at the beginning of the year.
Tag bonus
E7 set her first record on the way north, when she flew non-stop for 10,200km (6,340 miles) to Yalu Jiang in China. She then flew a further 5,000km (3,000 miles) to the godwit breeding grounds in Alaska. And on the way back to New Zealand, her tag still working, E7 set another record (7,150 miles).
"We were pretty impressed when she did 10,200km on the way north," says Massey University ecologist Phil Battley. "And the fact that she can now do 11,500km... it's just so far up from what we used to believe 10 years ago when we were thinking a five or 6,000km flight was extremely long. Here we've doubled it," adds the New Zealand coordinator of what is an international study.
For researchers, tracking the second leg of E7's journey was a bonus - her implanted satellite tag kept working well past its expected cut-off date.
"If you're trying to confirm how far birds fly and whether they are making stop-offs, it's only now with the technology being small enough, you can do this remotely. Otherwise we'd still be using educated guess work," Dr Battley says.
And that means the researchers now know that the godwits really are the champions of avian migration. Unlike seabirds, which feed and rest on their long journeys or swifts which feed in flight, the godwits make their long journeys without feeding or drinking.
Plump up
Next year, Dr Battley hopes to implant satellite tags into larger male godwits (this year the males had external satellite tags attached) to check that the male birds follow the same path as the females. 
Meantime any chicks E7 would have produced during her two months in Alaska will be getting ready to leave the Yukon Delta in a few weeks as the first young godwits usually arrive in New Zealand early next month.
"Some might fly down in flocks with adults but other ones will fly down without any adults involved at all which is pretty amazing," says Dr Battley. "They're only two months old and here they are about to fly from Alaska to New Zealand."
And their mum? "She'll be eating lots at the moment and probably resting up; and she'll go back to her main routines. Then, come about February next year or January, she'll start moulting into her breeding plumage and getting fat again.
"Then it will all start again."
The New Zealand godwit tracking effort is part of the broader Pacific Shorebird Migration Program, a joint initiative between the US Geological Survey and PRBO Conservation Science.
Hormone linked to autistic traits
Tuesday, 11 September 2007
High levels of a male sex hormone in foetuses are linked to a higher chance of developing autistic traits in childhood, scientists say.
The findings come from an eight-year study relating the development of 253 children to levels of testosterone they were exposed to in the womb.
The scientists said it was unclear whether the hormone was causing the traits or was a by-product of them.
The research was presented at the BA Festival of Science in York.
The research team, from the University of Cambridge, looked at levels of foetal testosterone in the womb by examining samples taken from women undergoing amniocentesis for clinical reasons.
The children were then followed during their development.
At 12 months, 18 months and 46 months, the scientists used tests to spot autism-like traits, such as counting how often a child looked at its mother's face or how large its vocabulary was.
At these early stages, the team found a link between the traits and higher foetal testosterone levels.
But the scientists' latest research results came from a study undertaken when the children were eight years old.
The children's mothers filled in a questionnaire called the autism spectrum quotient. This is designed to test the number of autistic traits a child has by examining factors such as social interest and pattern recognition.
Typical questions included whether the child preferred social activities like parties or spending time alone, or whether he or she was quick at picking up numerical patterns, like remembering number plates or phone numbers.
The results were then compared with the pre-natal testosterone levels, which had a 20-fold variation, between 0.1 to 2.05 nanomoles per litre.
Bonnie Auyeng, who carried out the study, said: "The correlation is not perfect, but foetal testosterone will account for about 20% of the variability in [questionnaire] scores. Although this doesn't sound like a very high number, it is statistically significant."
Extreme male brain
Professor Simon Baren-Cohen, who was also involved in the study, said: "This is the first time autistic traits have been linked to levels of foetal testosterone, measured in the womb using amniocenteses."
Animal research has previously linked brain development to foetal testosterone levels, and some believe the hormone may play a causal role in autism.
However, the scientists stressed that the study only showed a link between autistic traits and the hormone, rather than a direct link to autism itself.
Dr Auyeng said: "We're still in the early stages of figuring out what actual role foetal testosterone plays. We don't know if it is causing autistic traits, if it is a by-product of them, or an indication of various interactions.
"We are just not sure yet."
Scientists currently do not know what causes elevated levels of foetal testosterone. Professor Baron-Cohen said previous research suggested that it could be a mixture of genetic and environmental factors.
He said that the hormone could be affecting the brain through altering neural cell connectivity and chemicals that carry messages, known as neurotransmitters.
The team is now planning to follow up their study to test direct links between autism and testosterone levels in foetuses. They will use Denmark's archive of 90,000 amniocentesis samples and its register of psychiatric diagnoses.
The work is connected to Professor Baron-Cohen's hypothesis suggesting that autism is a version of the extreme male brain.
He said that although researchers had tested this theory at the psychological level, the new studies meant it could now be tested at the biological level.
Whale 'success story' questioned
Monday, 10 September 2007
A whale conservation success story, the recovery of the eastern Pacific gray whale, may not be quite what it seems.
Since the end of commercial whaling, numbers rose to about 20,000, thought to be the level they had been at before hunting began.
But a new study using genetic methods, reported in the journal PNAS, suggests pre-hunting numbers were much higher.
The scientists say climate change may be altering the whales' supply of food significantly.
Earlier this year, researchers noted signs that grays were showing distinct signs of malnutrition when they arrived at their winter breeding grounds along Mexico's Baja peninsula.
They raised the idea that this might be connected with climate change. But the prevalent theory was that numbers had risen beyond the maximum level which the ecosystem could support.
The new research challenges that idea.
"I think that when we see large-scale issues in the population, such as starving or malnourished whales, we should be looking to long-term climatic changes in their feeding grounds," said Liz Alter from Stanford University, US.
Stock take
A few hundred years ago, three separate populations of gray (or grey) whales lived in the oceans.
The Atlantic stock is thought to have perished in the first frenzies of commercial hunting. Later, the eastern and western Pacific populations almost followed suit.
The western stock, which lives along the eastern coast of Russia, is close to extinction once more, with development for oil and gas fields the prime cause. Numbers may be as low as 120.
But the eastern Pacific gray has supposedly seen rude health. It was taken off the US endangered species list in 1994, with numbers each year hovering about 20-25,000, which historical records from the whaling industry and computer models of population indicated was around the historical level. 
The new genetic analysis, which Liz Alter's group has published in Proceedings of the National Academy of Sciences (PNAS), challenges this view.
By looking at variation in the animals' DNA, the team concludes there were once 76,000-118,000 grays in the Pacific.
Even if those numbers were split between the eastern and western stocks, this indicates that the population of the eastern gray today is well below the historical level.
The researchers themselves acknowledge that further analysis should be done to confirm their findings. In particular, they would like to have samples from the critically endangered western stock, but given its parlous health, this would clearly be a sensitive issue.
Confirmation could have implications for traditional, or subsistence, whaling.
Aboriginal groups in Chukotka in the Russian northeast are permitted to hunt 124 eastern grays each year to provide meat for their communities.
The Makah tribe of Washington State near Seattle is allowed a further five. Its hunting is currently suspended pending a domestic US legal settlement, though one gray was killed just this weekend, apparently without permission of tribal elders.
If historical numbers were much higher, that would imply the grays are not as robust as believed, which could lower these hunting quotas still further.
9/11 demolition theory challenged
Tuesday, 11 September 2007
An analysis of the World Trade Center collapse has challenged a conspiracy theory surrounding the 9/11 attacks.
The study by a Cambridge University, UK, engineer demonstrates that once the collapse of the twin towers began, it was destined to be rapid and total.
One of many conspiracy theories proposes that the buildings came down in a manner consistent with a "controlled demolition".
The new data shows this is not needed to explain the way the towers fell.
Over 2,800 people were killed in the devastating attacks on New York.
After reviewing television footage of the Trade Center's destruction, engineers had proposed the idea of "progressive collapse" to explain the way the twin towers disintegrated on 11 September 2001.
This mode of structural failure describes the way the building fell straight down rather than toppling, with each successive floor crushing the one beneath (an effect called "pancaking").
Resistance to collapse
Dr Keith Seffen set out to test mathematically whether this chain reaction really could explain what happened in Lower Manhattan six years ago. The findings are published in the Journal of Engineering Mechanics.
Previous studies have tended to focus on the initial stages of collapse, showing that there was an initial, localised failure around the aircraft impact zones, and that this probably led to the progressive collapse of both structures. 
In other words, the damaged parts of the tower were bound to fall down, but it was not clear why the undamaged building should have offered little resistance to these falling parts.
"The initiation part has been quantified by many people; but no one had put numbers on the progressive collapse," Dr Seffen told the BBC News website.
Dr Seffen was able to calculate the "residual capacity" of the undamaged building: that is, simply speaking, the ability of the undamaged structure to resist or comply with collapse.
His calculations suggest the residual capacity of the north and south towers was limited, and that once the collapse was set in motion, it would take only nine seconds for the building to go down.
This is just a little longer than a free-falling coin, dropped from the top of either tower, would take to reach the ground.
'Fair assumption'
The University of Cambridge engineer said his results therefore suggested progressive collapse was "a fair assumption in terms of how the building fell".
"One thing that confounded engineers was how falling parts of the structure ploughed through undamaged building beneath and brought the towers down so quickly," said Dr Seffen. 
He added that his calculations showed this was a "very ordinary thing to happen" and that no other intervention, such as explosive charges laid inside the building, was needed to explain the behaviour of the buildings.
The controlled detonation idea, espoused on several internet websites, asserts that the manner of collapse is consistent with synchronised rows of explosives going off inside the World Trade Center.
This would have generated a demolition wave that explained the speed, uniformity and similarity between the collapses of both towers.
Conspiracy theorists assert that these explosive "squibs" can actually be seen going off in photos and video footage of the collapse. These appear as ejections of gas and debris from the sides of the building, well below the descending rubble.
Other observers say this could be explained by debris falling down lift shafts and impacting on lower floors during the collapse.
Dr Seffen's research could help inform future building design.
Solar plane flies into the night
Sunday, 9 September 2007
A lightweight solar-powered plane has smashed the official world record for the longest-duration unmanned flight.
UK defence firm Qinetiq, which built the Zephyr unmanned aerial vehicle, said it flew for 54 hours during tests.
The researchers believe it is the first time a solar-powered craft has flown under its own power through two nights.
The previous unmanned endurance record was set in 2001 by a jet-powered US Air Force Global Hawk surveillance aircraft which flew for more than 30 hours.
The Zephyr's 54-hour endurance flight will not enter the record books because representatives from the world air sports federation - the FAI - were not notified about the secretive test.
However, they were informed about a second, 33-hour flight which could still become an official record.
Zephyr's development team say that whatever the result, it believes it has built a record breaker.
"This aeroplane is going to go a lot higher and a lot further," Chris Kelleher, Zephyr's technical director and "pilot", told the BBC News website. "You ain't seen nothing yet."
Night flight
Zephyr was originally developed to take pictures of a giant helium balloon that attempted to break the world altitude record for a manned envelope in 2003.
The attempt was shelved after the Qinetiq 1 balloon sprang a leak.
However, the defence firm has continued to develop the "strato-plane" for military applications, as well as for Earth-observation and communications.
The latest tests took place at the US military White Sands Missile Range in New Mexico.
On the first flight, the aircraft, which has a wingspan of 18m (59ft), flew for more than two days before it developed a fault. The second, shorter flight was curtailed when thunderstorms threatened the propeller-driven plane.
"What was proved - and what was a world first - was that the aircraft was flown using its solar electrical power system through two complete diurnal cycles," said Paul Davey, Zephyr's business development director.
"The aircraft was flown on solar power and charged its batteries during the day, discharged its batteries during the night, and remained aloft the following dawn when the cycle was repeated."
During the flights, Zephyr reached a maximum altitude of more than 58,000ft (18,000m).
Record bid
The plane is launched by hand and is flown manually to 10,000ft (3,000m).
"On the ground we have all of the instrumentation a pilot would see on a manned plane," explained Mr Kelleher. 
"We have a basic instrument panel, we have a forward-looking view [from a camera], and we have all of the telemetry coming down to us."
An autopilot took over the controls for the remainder of the tests.
Although, the first flight was more than 20 hours longer than the current record, it will not enter the record books. The Qinetiq team did not pre-notify the FAI (Federation Aeronautique Internationale) of its first flight, a requirement of an official world record.
And, although they did notify the body of the second flight, no FAI official was present to oversee it. "The record attempt was announced very late," said an FAI spokesperson.
However, the Qinetiq team believes that air traffic controllers at the White Sands base will verify the 33-hour, 43-minute flight, which took place on the 31 August.
The FAI spokesperson said the organisation was waiting for details of the tests to be submitted.
Planetary explorer
Zephyr is not the first solar-powered plane to fly through the night. 
A craft called SoLong, developed by US firm AC propulsion, flew for 48 hours in 2005.
However, unlike Zephyr, the craft was not under constant power for the duration of the flight. Instead, it occasionally had to glide or soar.
Other companies and organisations have also developed similar craft.
The US space agency Nasa developed both the Pathfinder and Helios vehicles.
The agency believed the vehicles could one day be used as a replacement for satellites or as unmanned drones to explore other planets such as Mars.
Helios, the successor of Pathfinder, set an altitude record in 2001 for a non-rocket-powered winged aircraft when it climbed to 96,863 feet (29.5km).
But in 2003, the vehicle broke up on a flight from the US Navy's Pacific Missile Range Facility on the Hawaiian island of Kauai.
Fragile cargo
Other companies currently building solar-powered planes include Swiss firm ETH.
Its experimental Sky-Sailor craft is much smaller than Zephyr, with a wingspan of just 3.2m (10ft), and is designed for use on Mars.
All of these prototype vehicles have flown autonomously or controlled by a pilot on the ground.
But in 2010, Swiss balloonist Bertrand Piccard plans to launch Solar Impulse, a manned plane in which he will attempt to circumnavigate the globe.
To carry the precious payload, the craft will have a huge wingspan of 80m (262ft), wider than the wings of the Airbus A380.
As the plane is piloted by only one person at a time, it will have to make frequent stopovers. The current plan is for the journey to be broken into five legs each lasting between four or five days.
Rise in divers mystifies experts
Friday, 7 September 2007
The success of a wild bird in Scotland despite declining numbers in the rest of Europe has mystified experts.
RSPB Scotland said it was delighted but puzzled by breeding figures for the red-throated diver.
The rarer black-throated diver is also on the increase, possibly thanks to the anchoring of man-made rafts in lochs.
A survey of divers by the RSPB and Scottish Natural Heritage (SNH) found the two species had increased in the UK by 16 and 34% in the last 12 years.
Both have declined in Europe and the black-throated diver was last week made a conservation priority by the UK Government because of the declines elsewhere.
In Scotland, its numbers rose from 187 pairs in 1994 to 217 pairs in 2006.
In the Highlands - their stronghold - they were declining because some nests were being drowned in floods while eggs at other sites were lost to collectors and predators.
The new study shows the greatest increase in the Western Isles, but also improved figures in the Highlands.
A total of 58 rafts have been installed on remote lochs in the region. They protect the birds from flooding and animals that prey on them and their eggs.
Stuart Benn, senior conservation officer for the RSPB, said: "We can't say hand on heart that the overall increase is due to the rafts because we haven't ringed the chicks, but there is no doubt that the rafts have turned out to be very, very good at what they do."
The RSPB said it was a mystery as to why red-throated divers have done so well.
Its numbers have risen from 935 to 1,255 breeding pairs in 12 years.
'Rain goose'
However, in Shetland the population has dropped from 700 pairs to 407.
The red-throated diver is steeped in mythology and is known as the rain goose in Orkney and Shetland.
In the 19th Century, it was regarded as a foreteller of storms in many parts of the world.
Dr Mark Eaton, an RSPB scientist, said: "We feared the numbers of red-throated divers might drop because the warming of the North Sea seems to be reducing stocks of the fish they feed on.
"The black-throated diver could also be at risk in the future, despite the recent increases. If climate change causes loch temperatures to rise, the small fish the birds feed on could grow too large to eat."
Virus implicated in bee decline
Thursday, 6 September 2007
A virus has emerged as a strong suspect in the hunt for the mystery disease killing off North American honeybees.
Genetic research showed that Israeli Acute Paralysis Virus (IAPV) turned up regularly in hives affected by Colony Collapse Disorder (CCD).
Over the last three years, between 50% and 90% of commercial bee colonies in the US have been affected by CCD.
The hives are transported around the country to pollinate important crops, notably to California for almonds.
The state produces about 80% of the world's almonds in an industry worth $2.5bn per year.
"This really highlights the value of pollinators," said Jeff Pettis, research leader of the US government's Bee Research Laboratory.
"We're operating under a limited number of colonies - we had five million in the 1950s, now we have half of that number."
Dr Pettis is one of the CCD research team that reports its initial findings in the journal Science.
Genetic trawl
The honeybee decline can be traced back at least 20 years, and the introducton of the parasitic varroa mite is one of the principal causes.
But in 2004, beekeepers began seeing and reporting a new and serious phenomenon, in which entire colonies would desert their hives, leaving behind their brood and stocks of food - a syndrome that was later labelled Colony Collapse Disorder.
Theories on what is causing it have ranged from mobile phone radiation to pesticides, from genetically-modified crops to climate change.
Disease remained a strong contender though, particularly in the light of the known impact of mites such as the varroa. And genetics offered the opportunity to analyse what organisms were living with and on the bees.
"The genome of the honeybee had just been completed," noted Diana Cox-Foster, an entomologist from Penn State Universiity. "So it was possible to do the (genetic) sequencing and then eliminate the genetic material of the bees."
The scientists' trawl revealed a diverse cargo even in healthy colonies. Eight types of bacteria appeared to be present in all bees, suggesting they perform some function useful to their hosts.
The researchers also found genes from parasites, fungi, and viruses, in both healthy hives and in those which had undergone collapse. But IAPV only appeared in samples from CCD populations.
Prime suspect
"This virus appears to be strongly associated with CCD," commented Dr Cox-Foster, "but whether it's the causative agent or just a very good marker (of the syndrome) is the next question we need to address."
And if it is a cause, it might not be the only one.
"I still believe that multiple factors are involved in CCD," said Jeff Pettis, "and what we need to do is look at combinations such as parasites, stress and nutrition (together with the virus)." 
Meanwhile, theories connected with mobile phones, climate change and GM crops can probably be discounted, the researcher suggested.
As its name would suggest, IAPV was first identified in Israel, but the symptoms it produces in bees there are quite different.
Whether this is down to a small genetic difference in the virus between continents, or whether IAPV is acting in concert with different environmental factors, is an open question.
Also open is the question of how the virus arrived in the US. One finger of suspicion points to Australia, from where the US began importing honeybees in 2004 - the very year that CCD appeared in US hives.
The researchers found IAPV in Australian bees, and they are now planning to go back through historical US samples to see if the Antipodean imports really were the first carriers.
If they were, the US might consider closing its borders to Australian bees.
If IAPV does turn out to be a major factor causing CCD, there may be little that scientists or beekeepers can do about it.
"We're unlikely to come up with a treatment for viruses in bees," said Dr Pettis, "and so beekeepers are likely just to have to keep the other things that might affect CCD, such as mites, under control."
With commercial honeybees worth an estimated $14bn to US agriculture, the political pressure on scientists to come up with some answers is considerable.
Tsunami concern for Bay of Bengal
Thursday, 6 September 2007
The northern end of the Bay of Bengal could be at risk of giant earthquakes and tsunamis in the coming decades, an Australian study concludes.
Such events have been thought unlikely there, in contrast to the area further south where the 2004 tsunami began.
But the new work, published in the journal Nature, has found "compelling evidence" for tsunami-triggering earthquake activity to the north.
Geologists have said this warning should be taken "very seriously".
The area is densely populated, and more than a million of people could potentially be at risk.
Releasing pressure
The magnitude 9.2 earthquake that struck off the Sumatran coast on 26 December 2004 and the tsunami it generated killed thousands of people and left millions homeless.
It stemmed from a geological area known as a "subduction zone". 
Here, part of the Indian/Australian tectonic plate was slowly burrowing beneath a component of the Eurasian plate.
This created stresses in the upper plate, which were violently released in the form of a "locked-thrust fault" earthquake as it sprung back up, which in turn triggered the tsunami.
Since then, another stress point has been identified to the east of the 2004 epicentre, but the subduction zone further north along the Myanmar coast was thought to be of little concern.
But Phil Cummins, lead author on the Nature paper and a geologist at Geoscience Australia, believes this is not the case.
He said: "I reviewed the geological literature and found the evidence for a lack of tectonic activity along the Myanmar coast was not compelling."
Historical evidence
Recent GPS data, he said, suggested that the plate boundary was at sea in this area, hidden below thick layers of sediment.
Dr Cummins said: "Although these GPS measurements are sparse, these show that there is active deformation near the Myanmar coast that is consistent with a locked thrust-fault offshore, which is the type needed to generate tsunami." 
The geologist also looked at accounts of an earthquake that occurred in the area in 1762, which wrenched up parts of the coast by between 3-7m.
His computer simulation of the quake, which he believes would have measured magnitude 8.8, showed that a similar event today would have significant impacts.
"Such an earthquake would generate a large tsunami that could have a pronounced impact on the Chittagong coast and the Ganges delta," he said.
"The latter region is home to 60 million people living within just 10m of sea level."
Meanwhile the quake itself could cause major damage to the region's largest cities, Calcutta and Dhaka. Overall, the simulation suggested that more than a million lives could be at risk.
'Alarming message'
Professor Richard Arculus, from Australian National University (ANU) in Canberra, said: "Phil Cummins' warnings should be taken very seriously.
"A few months before the devastating earthquake and accompanying tsunami triggered off northern Sumatra in late 2004, Phil Cummins published a perceptive analysis of historic events of this nature in the region.
"He warned that countries bordering the Indian Ocean, including the northern coast of Australia, were at significant risk, and the lack of a tsunami warning system analogous to that deployed in the Pacific was a serious issue.
"So his credibility with respect to tsunamigenic earthquakes is established. "
Kevin McCue, a professor at Central Queensland University (CQU), added: "The message is alarming, perhaps justifiably, given the unexpected disaster that followed the great Sumatran earthquake and tsunami of 2004, a disaster of local, regional and global reach."
But he added: "Disaster planners might need more information than is given in the paper, particularly some quantitative measure of uncertainties in the science."
Phil Cummins agrees that more work is needed to confirm his analysis, and suggests this should take place before any drastic mitigation measures are considered.
Space pile-up 'condemned dinos'
Wednesday, 5 September 2007
A colossal collision in space 160 million years ago set the dinosaurs on the path to extinction, a study claims.
An asteroid pile-up sent debris swirling around the Solar System, including a chunk that later smashed into Earth wiping out the great beasts.
Other fragments crashed into the Moon, Venus and Mars, gouging out some of their most dominant impact craters, a US-Czech research team believes.
Its study, based on computer modelling, is reported in the journal Nature.
"We believe there is a direct connection between this break-up event, the asteroid shower it produced and the very large impact that occurred 65 million years ago that is thought to have wiped out the dinosaurs," Dr Bill Bottke from the Southwest Research Institute, Boulder, Colorado, US, told BBC News.
Rock swarm
A number of studies have considered what appears to have been an increase in asteroid strikes on Earth in the last 100-200 million years - something like a doubling over the long-term norm.
Dr Bottke and his colleagues have attempted to show that this surge was probably triggered by the catastrophic disruption of a 170km-wide rock in the asteroid belt between Mars and Jupiter about 160 million years ago.
The mountainous object's break-up - induced by a collision with a space rock under half its size - resulted in the cluster of fragments visible today and known as the Baptistina family, they say.
The researchers have modelled the evolution of this cluster and concluded that it would have lost many of its original members to the inner Solar System.
The analysis shows, the team says, that one large shard from the break-up probably created the 85km-wide Tycho impact crater on the Moon 108 million years ago.
But even more likely, they contend, is that a still larger fragment dug out the 180km-wide Chicxulub crater off what is today the Yucatan Peninsula of Mexico.
This is the impact scar many scientists link to the Cretaceous/Tertiary Mass Extinction, which saw the dinosaurs disappear into the fossil record.
'Inevitable' outcome
"The [Baptistina] break-up event took place very close to what one might describe as a 'dynamical superhighway', a way for objects to escape the asteroid belt - and many of them did so," explained Dr Bottke.
"These fragments began to wander the region where the Earth and Moon are located; and in fact, so many escaped that it became almost inevitable that some of the larger pieces were going to hit the planets of the inner Solar System." 
Chemical analysis of projectile material connected to the Chicxulub event is also said to tie its impactor to the type of rocks that make up the Baptistina family.
Philippe Claeys and Steve Goderis from the Free University of Brussels, Belgium, write a commentary on the research in Nature.
They say that unless a rogue comet came from the outer edge of the Solar System ("a rather unlikely event"), the Baptistina asteroid family remains a likely source for the Chicxulub impactor.
"It is a poignant thought that the Baptistina collision some 160 million years ago sealed the fate of the late-Cretaceous dinosaurs well before most of them had evolved," they write.
Dr Bottke's colleagues on the study were David Vokrouhlicky and David Nesvorny.
'Human-animal' embryo ruling due
Regulators are due to make a decision whether to allow human-animal embryos to be created and used for research.
The Human Fertilisation and Embryology Authority is expected to give the plan the go-ahead in principle - but each case will still be judged individually.
An HFEA consultation showed the public were "at ease" with the idea when told it could pave the way for therapies for conditions such as Alzheimer's disease.
But a leading opponent said many people would be "horrified" by such a move.
Scientists want to create hybrid embryos by merging human cells with animal eggs in a bid to extract stem cells.
The cells form the basic building blocks of the body and have the potential to become any tissue, making them essential for research.
At the moment, scientists have to rely on human eggs left over from fertility treatment, but they are in short supply and are not always good quality.
Two teams from Kings College London and Newcastle University have already applied to the HFEA to use hybrid embryos.
If the HFEA does agree human-animal embryo research can go ahead, there would be individual hearings for these two applications, probably in November.
Other scientists are also expected to follow suit.
Reversed decision
Dr Lyle Armstrong, of Newcastle University, said: "It does seem a little abhorrent at first analysis, but you have to understand we are using very, very little information from the cow in order to do this reprogramming idea. "It's not our intention to create any bizarre cow-human hybrid, we want to use those cells to understand how to make human stem cells better."
And Lib Dem MP Dr Evan Harris, a member of the House of Commons science and technology committee which has already called for such research to be allowed, said: "No good reasons for banning this research have been identified.
"The HFEA must now clear the way for their research licence committee to grant permission for some of our top scientists to continue their world-leading medical research using hybrid embryos."
The HFEA decision comes amid government moves to lay down regulations covering such research - the law governing embryo research is out of date and does not cover the issue.
The government originally proposed banning the technique in a White Paper, but reversed its decision this year in a bill which proposed allowing hybrid embryos which were 99.9% human and 0.1% animal, following a backlash by scientists and patient groups.
But the HFEA has carried out its own review ahead of parliament passing the legislation so as not to hold back research.
The regulator can grant licences to scientists to pursue such research, but would then have to change its criteria if future rules contradicted its own practices.
'Dehumanised'
Dr Helen Watt, from the Linacre Centre for Healthcare Ethics, said the technique was "a further violation of the rights of the embryo".
"The embryo is deprived not only of its life in the course of the experiment, but of any human parents," she said.
"It is further dehumanised by the very method of its creation."
And Josephine Quintavalle, of the campaign group Comment on Reproductive Ethics, said the HFEA was wrong to be pushing ahead with a decision which should be left to parliament.
"Using hybrid embryos has never been acceptable - it offends the dignity of humans and animals.
"Many people will be horrified if this is allowed."
But Parkinson's sufferer Frank Brooks backed the use of hybrid embryos in the search to find a cure for the disease.
"It would be an enormous benefit if that cure was developed to the people who are young enough to benefit from it, because it's going to be a few years before it's here," Mr Brooks said.
"But if we don't start now we're never going to get there."
Congo rebels seize gorilla park
Rebels in the Democratic Republic of Congo have taken control of large parts of the Virunga National Park, home to rare mountain gorillas.
The move has raised fears for the fate of the gorillas. Only 700 remain - half of which are in Virunga.
Meanwhile, the army says it has killed at least 28 troops loyal to rebel General Laurent Nkunda in the latest fighting in eastern DR Congo.
Some 170,000 people have fled the area this year, says the UN refugee agency.
"If anything happens to the mountain gorillas now, there is nothing we can do," said Norbert Mushenzi of the Congolese Institute for the Conservation of Nature (ICCN).
"As of today, the sector is no longer under my control and we have been rendered powerless by these actions."
Nine gorillas have been killed this year, allegedly by Gen Nkunda's men, sparking outrage among conservationists.
'State of war'
Gen Nkunda's forces are believed to have moved into the park in pursuit of Rwandan Hutu rebels, who have bases there.
Officials from local conservation group, Wildlife Direct, say the forces looted weapons and communication equipment from Jomba and Bikenge ranger patrol posts within the park. 
A third post, Bukima, was being evacuated for fear of imminent attack, the group said.
Gen Nkunda, a Tutsi, has accused the government of forming an alliance against him with the Hutu FDLR, accused of involvement in the 1994 Rwandan genocide of Tutsis.
After Tutsis took control in Rwanda, they crossed the border into eastern DR Congo.
Over the weekend, Gen Nkunda told the BBC there was a "state of war" in North Kivu.
The United Nations says up to 10,000 people have fled fighting into Uganda.
The UN refugee agency says it is organising shelter for those who fled the violence Monday night and wish to stay on the Ugandan side of the frontier.
Following a visit by Rwandan Foreign Minister Charles Murigande to Kinshasa, DR Congo has promised to increase its operations against the FDLR.
Rwanda has twice invaded its large neighbour, saying it is trying to stop the FDLR from attacking its territory.
Peacekeepers
BBC Kinshasa correspondent Arnaud Zajtman says that the two countries are still divided by the same issues - DR Congo wants Rwanda to reign in Tutsi fighters, such as Gen Nkunda, while Rwanda wants DR Congo to stop the activities of the Hutu rebels, known as the FDLR. 
Last month, Rwanda protested against DR Congo's move to call off an offensive against the FDLR.
Mr Murigande and his Congolese counterpart Mbusa Nyamwisi also asked the UN to intensify patrols in the east of the country where fighting is raging.
The UN has some 17,000 peacekeepers in DR Congo - the largest such force in the world and has sent an extra 200 troops to the region after the latest fighting.
Our reporter says the ministers have also agreed to form a commission to ensure that Congolese ethnic Tutsis who are refugees in Rwanda are repatriated.
US adventurer Fossett is missing
An extensive search has been launched for record-breaking US adventurer Steve Fossett, who went missing in his airplane in the Nevada desert.
Mr Fossett was reportedly last seen taking off from the private airfield at the Flying M Ranch near Yerington, Nevada, on Monday evening.
He was flying a blue and white single-engine Citabria plane.
A Civil Air Patrol spokeswoman, Major Cynthia Ryan, said 13 planes were searching for the 63-year-old.
The authorities were alerted when Mr Fossett's family reported him missing after he failed to return from a trip which should have lasted just a few hours.
Maj Ryan said conditions for Mr Fossett's flight had been "optimal", with calm to light winds.
"The Civil Air Patrol is looking for him. One problem is he doesn't appear to have filed a flight plan," Federal Aviation Administration spokesman Ian Gregor told the Associated Press news agency.
Mr Gregor said the Air Force's Rescue Co-ordination Center in Langley, Virginia was overseeing the search.
Officials say Mr Fossett's plane was fitted with an electronic beacon which can be picked up by satellites, but have refused to comment on whether any signal has been located.
Exclusive airstrip
Speaking to the BBC about the disappearance of his former crewmate and one-time ballooning rival, Virgin Atlantic President Sir Richard Branson said he was confident his friend would be found safe and well.
"Steve is a tough old boot. I suspect he is waiting by his plane right now for someone to pick him up," Mr Branson said. 
"The ranch he took off from covers a huge area and Steve has had far tougher challenges to overcome in the past. Based on his track record, I feel confident we'll get some good news soon."
Mr Branson's spokesman said Mr Fossett was carrying four full tanks of fuel, and was searching for empty lake beds suitable for an upcoming attempt at the land speed record.
Trooper Chuck Allen from the Nevada Highway Patrol told the BBC that teams from neighbouring California were aiding the search.
"Several aircraft (are) flying many hundreds of square miles doing a very extensive grid search to try to locate this particular aircraft," he said.
The search was later suspended for the night.
Mr Fossett reportedly took off from an airstrip near Yerington, Nevada, owned by William Barron Hilton, heir and co-chairman of the Hilton Hotel chain.
Record breaker
Since the 1960s the airstrip has been regarded as a Mecca for pilots and a popular haunt for world class aviators and astronauts alike.
In 1981 Mr Barron Hilton founded the Barron Hilton Cup, a prestigious international competition for gliders.
Mr Fossett made his fortune in the American financial services industry, but he is best known for the impressive number of world records he has broken as a pilot, balloonist and sailor.
He has set 116 records in five different sports, more than 60 of which remain unbroken.
Last year Mr Fossett broke the world record for flying further than anyone else in history.
In March 2005, he became the first person to fly a plane solo around the world without refuelling.
And in 2002 he was the first person to fly a balloon around the world solo.
