Friday, January 22, 2010
Synthetic biology cells produce light show
Synthetic biology cells produce light show
| By Victoria Gill Science reporter, BBC News |
The cells produce waves of light as they express a fluorescent protein
Scientists have produced a very unusual light show, engineering bacterial cells to fluoresce in synchrony.
The researchers turned the cells into synchronised "genetic clocks" - programming them to switch a fluorescent protein on and off.
These waves of activity could eventually be used to make biological sensors, or to programme cells to release timed doses of medicine.
The researchers report the advance in the journal Nature.
Synchronised waves, or oscillations, are important to scientists because they control crucial functions in the human body, such as the sleep-wake cycle, learning processes and the regular release of substances including insulin.
This same team of researchers, which was led by Dr Jeff Hasty from the University of California San Diego, US, first produced "flashing" cells a year ago. These bacterial clocks could be tuned to alter the rate at which they blinked on and off.
But this latest advance allows the cells "talk to each other" and synchronise their activity as they grow into a colony.
"If you want a sensor - if you want to use the rate at which the cells switch on and off to signal something about the environment, you need a synchronised signal," explained Dr Hasty.
To achieve this, he and his team incorporated two genes into the bacterial cells.
 |   The real breakthrough will be when we can do this in mammalian cells  Professor Martin Fussenegger ETH Zurich |
One of the genes produced what he described as "a negative feedback system". This was the key component that stimulated oscillations in the cells - effectively switching the fluorescent protein on and off.
The other gene produced a chemical that travelled between the cells, allowing them to talk to each other and communicate the rate of his oscillation.
Professor Martin Fussenegger, a scientist from the Swiss science and technology university ETH Zurich, who was not involved in the study, said that this was "the first time that time-keeping devices in different individual cells had been synchronised".
"It's a dramatic achievement. The real breakthrough [will be] when we can do this in mammalian cells, and this has laid the foundation for that," he told BBC News.
"Oscillators could eventually be designed to produce insulin every six hours [in diabetic patients].
"When doctors tell you to take this pill three times a day, that's this is nothing more than an oscillation - a dose at a frequency. An engineered oscillator could do this automatically."
In this same issue of Nature, the editors have marked what many scientists consider to be the 10th anniversary of the birth of synthetic biology - the discipline that sets out to engineer or manipulate life.
"Part of the whole excitement of synthetic biology was to make a branch of molecular biology into an engineering discipline," said Dr Hasty. "The aim is to use computational tools to design biological circuits from scratch.
"We're not quite there yet, but we can already design some of these [simple] systems."
Thursday, January 21, 2010
Historic Bentley snowflake photos for sale in US
Historic Bentley snowflake photos for sale in US
Ten of the pioneering photos of snowflake crystals US farmer Wilson A Bentley began taking more than a century ago are to be sold in New York.
Bentley (1865-1931) is credited with capturing the first images of single snowflakes on camera. He made thousands of the jewel-like prints, no two alike.
His photomicrography technique involved a microscope and a bellows camera.
He caught pneumonia in a blizzard and died just weeks after the publication of his book Snow Crystals.
| When a snowflake melted, that design was forever lost Wilson A Bentley |
The sale of his crystal images is a rare event, the Associated Press news agency reports.
Chicago art gallery owner Carl Hammer is selling them along with 16 of Bentley's winter scenes at an antiques show at New York's American Folk Art Museum.
"They're remarkably beautiful," said Mr Hammer.
"There are imperfections on the outer edges of the image itself and on the paper, but the images themselves are quite spectacular."
'Good for 100 years'
Snowflake expert Kenneth G Libbrecht said the photos did not meet modern standards because of the "crude equipment" Bentley used.
"But he did it so well that hardly anybody bothered to photograph snowflakes for almost 100 years," Mr Libbrecht added.
Bentley, who was known as The Snowflake Man, wrote in 1925: "Under the microscope, I found that snowflakes were miracles of beauty and it seemed a shame that this beauty should not be seen and appreciated by others.
"Every crystal was a masterpiece of design, and no one design was ever repeated. When a snowflake melted, that design was forever lost."
Mr Libbrecht said the method of singling out a crystal to photograph had not changed.
"You basically let the crystal fall on something, black or dark-coloured, and then you have to pick it up with a toothpick or brush and put it on a glass slide," he said.
Tuesday, January 19, 2010
A rare glimpse of the cave of crystals
A rare glimpse of the cave of crystals
Mexico's Cave of Crystals stunned geologists when it was first discovered in 2000. The underground chamber contains some of the largest natural crystals ever found - some of the selenite structures have grown to more than 10m long. Professor Iain Stewart got a rare glimpse of the subterranean spectacle while filming for the new BBC series How the Earth Made Us.
Professor Stewart describes the cave as a geological wonder of the world
We kept on being told how difficult it was going to be to film in the Naica Cave, but nothing really prepares you for the extremes of that cavern.
It's about 50C in there, but it's the virtually 100% humidity added on top that makes it a potential killer.
That combination means that when you breathe air into your body, the surface of your lungs is actually the coolest surface the air encounters. That means the fluid starts to condense inside your lungs - and that's really not good news.
When the cave was first discovered it was just an accident.
Miners working in the Naica silver mine broke through the walls of the cavern and were astounded to discover these enormous crystals - the biggest anywhere on Earth.
 To enter the cave, special gear needs to be worn |
But when the first people went in to explore, they were almost overcome by the conditions - and there's some pretty hairy video footage of them coming out of the cave on the verge of losing consciousness. So we knew the dangers were real.
When you first look at the kit your first thought is: "Is that it?"
There's a special cooling suit - which is basically like a suit of chain mail but filled with ice cubes.
Then there's a breathing system which feeds cool, dry air into your mask.
It's OK to take the mask off for a short while, but do without it for more than about 10 minutes, and it's likely that you're going to start keeling over.
I was lucky of course. All I had to do was stand there and talk, but the cameraman and all the others helping set out the lights were having to work in these conditions, wearing these cumbersome suits, and they really struggled.
We had a doctor outside the cave to monitor our vital signs, and we were coming out of the cavern with our heart rates up at 180.
The biggest danger was falling over; rescuing someone inside would have been very tricky.
Despite all the dangers, my overwhelming memory is the sheer beauty of the place.
Whenever people around me were faffing around with equipment, I'd just stop and look around at the crystals.
It's such a glorious place, it's like being in a modern art exhibit.
I kept reminding myself: "You're in the Naica Cave", because there's only a handful of geologists that have ever been in there, and so I was aware of how incredibly privileged I was.
Yet remarkably, for the people who own and run the Naica mine, the crystal cave is a side-show, a distraction.
They don't make any money out of it and sooner or later, when the economics of the mine change, it will close.
|  We can be sure that there will be discoveries even more spectacular than Naica Professor Iain Stewart |
The pumps will be taken out, the mine and the cave will flood, and the crystals will once more be out of our reach.
But perhaps we should console ourselves with the thought that there are certainly lots more crystal caves waiting to be discovered.
For starters, the geology of the area around the cave suggests that there could be more crystal caves in the area around Naica.
But more broadly, the Earth's crust must be riddled with wonders like this.
We know more about the outer edges of the Solar System than we do about the first kilometre of the Earth's crust.
As we learn more about the crust, we can be sure that there will be discoveries even more spectacular than Naica. I just hope I'm around to see them.
How the Earth Made Us: The epic story of how geology, geography and climate have influenced mankind is on Tuesday 19th January on BBC Two at 2100 GMT
UN climate body admits 'mistake' on Himalayan glaciers
UN climate body admits 'mistake' on Himalayan glaciers
| By Richard Black Environment correspondent, BBC News website |
The vice-chairman of the UN's climate science panel has admitted it made a mistake in asserting that Himalayan glaciers could disappear by 2035.
The Intergovernmental Panel on Climate Change (IPCC) included the date in its 2007 assessment of climate impacts.
A number of scientists have recently disputed the 2035 figure, and Jean-Pascal van Ypersele told BBC News that it was an error and would be reviewed.
But he said it did not change the broad picture of man-made climate change.
The issue, which BBC News first reported on 05 December, has reverberated around climate websites in recent days.
| It is so wrong that it is not even worth discussing Georg Kaser, University of Innsbruck  |
Some commentators maintain that taken together with the contents of e-mails stolen last year from the University of East Anglia's Climatic Research Unit, it undermines the credibility of climate science.
Dr van Ypersele said this was not the case.
"I don't see how one mistake in a 3,000-page report can damage the credibility of the overall report," he said.
"Some people will attempt to use it to damage the credibility of the IPCC; but if we can uncover it, and explain it and change it, it should strengthen the IPCC's credibility, showing that we are ready to learn from our mistakes."
Grey area
The claim that Himalayan glaciers could disappear by 2035 appears to have originated in a 1999 interview with Indian glaciologist Syed Hasnain, published in New Scientist magazine.
The figure then surfaced in a 2005 report by environmental group WWF - a report that is cited in the IPCC's 2007 assessment, known as AR4.
An alternative genesis lies in the misreading of a 1996 study that gave the date as 2350.
AR 4 asserted: "Glaciers in the Himalayas are receding faster than in any other part of the world... the likelihood of them disappearing by the year 2035 and perhaps sooner is very high."
Dr van Ypersele said the episode meant that the panel's reviewing procedures would have to be tightened.
Slow reaction?
The row erupted in India late last year in the run-up to the Copenhagen climate summit, with opposing factions in the government giving radically different narratives of what was happening to Himalayan ice.
 IPCC chief Rajendra Pachauri has been criticised by Jairam Ramesh |
In December, it emerged that four leading glaciologists had prepared a letter for publication in the journal Science arguing that a complete melt by 2035 was physically impossible.
"You just can't accomplish it," Jeffrey Kargel from the University of Arizona told BBC News at the time.
"If you think about the thicknesses of the ice - 200-300m thicknesses, in some cases up to 400m thick - and if you're losing ice at the rate of a metre a year, or let's say double it to two metres a year, you're not going to get rid of 200m of ice in a quarter of a century."
The row continues in India, with Environment Minister Jairam Ramesh calling this week for the IPCC to explain "how it reached the 2035 figure, which created such a scare".
Meanwhile, in an interview with the news agency AFP, Georg Kaser from the University of Innsbruck in Austria - who led a different portion of the AR4 process - said he had warned that the 2035 figure was wrong in 2006, before AR4's publication.
"It is so wrong that it is not even worth discussing," he told AFP in an interview.
He said that people working on the Asia chapter "did not react".
He suggested that some of the IPCC's working practices should be revised by the time work begins on its next landmark report, due in 2013.
But its overall conclusion that global warming is "unequivocal" remains beyond reproach, he said.
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Commentary
Speaking from a statistics background, to say that one variable is the cause to a global phenomenon such as global warming is like saying I can tell you if it'll rain in 4 months.
We just don't have that much data to much assumptions that big. Even if we could show a correlation between Co2 and Temp, we still have to prove CAUSATION. Correlations are not causations because of lurking variables, also known as, Confounders.
To try and rule out all confounders, or lurking variables, in a global theorem, is a joke at best.
We should stop trying to make global predictions about weather when in reality we don't know what'll happen 5 years from now. To even ascribe causation is Scientific suicide, as far as credibility goes.
Venezuela's economy in further slide
Venezuela's economy in further slide
| By Robert Plummer Business reporter, BBC News |
Back in 2002, just weeks before Venezuela's President Hugo Chavez was briefly forced from office by a coup attempt, I found myself planning an impromptu trip to his country.
 Price checking is done by the military in Venezuelan supermarkets nowadays |
Having just got married in Trinidad, my wife and I were heading to Brazil for a honeymoon, via a short stopover in Caracas.
I had visited Venezuela a few times before and had reported for the BBC on the early days of Mr Chavez's Bolivarian Revolutionary Movement, as it was originally known.
However, I had not had the opportunity to set foot in the country since his rise to the presidency in 1998.
A former colleague who had moved to Caracas some years earlier was helpful in indicating what to expect.
"You'll notice some deterioration," he laconically observed.
He was right. The Venezuelan capital was never the prettiest in Latin America, but it had definitely taken a turn for the worse.
Bags of rubbish were piled up on patches of waste ground, while many walls were adorned with pro- and anti-Chavez graffiti.
The city centre shops were less well-stocked than before, and the standard of service in them seemed to have declined.
Military checks
Nearly eight years on, that deterioration in Venezuela's infrastructure and economy has continued.
Those same city centre shops are now subject to raids by soldiers, checking to make sure prices have not been artificially raised in the wake of this month's currency devaluation.
The bolivar's official exchange rate, which is set by government decree, had been held at 2.45 to the US dollar since the last devaluation in March 2005.
 Shops in Caracas have been dimming their lights to conserve power |
But it now has two rates - 2.60 to dollar for "priority" imports, and 4.30 to the dollar for other items considered non-essential - a 50% devaluation.
At the same time, chronic energy shortages have led to a programme of regular power cuts throughout the country, although the resulting outcry has led Mr Chavez to exempt Caracas from the blackouts while maintaining them elsewhere.
Opposition politicians have been quick to accuse the Chavez government of underinvestment, just as they did in 2006 when a viaduct collapsed on the main road from Caracas to the airport, rendering the highway impassable for more than a year.
But in both cases, previous administrations are equally to blame for the lack of infrastructure spending, including Mr Chavez's immediate predecessor as president, Rafael Caldera, who died on Christmas Eve aged 93.
Price spiral
More worrying is Venezuela's apparent inability to get to grips with persistent inflation, which is now the highest in Latin America, reaching an annual rate of at least 27% in 2009.
Last week, yet again, Mr Chavez merely fuelled the inflationary spiral by raising the minimum wage to compensate workers for their loss of purchasing power.
At the same time, he has attempted to impose price controls which have largely failed to work.
 Exito means "success" - but its French owners failed to please Mr Chavez |
As a result, he has increasingly resorted to the ultimate economic sanction - confiscating the businesses of those who refuse to curb their prices.
The latest victim of this policy is the Exito supermarket chain - run by a Colombian retailer but ultimately controlled by France's Casino group, which also owns stores in Brazil, Argentina, Mexico and Uruguay.
That makes it the ideal target for Mr Chavez, who has ordered its expropriation as an example of "transnational companies" coming to Venezuela to "speculate with our prices".
Yet there is little evidence that Exito was doing anything other than reflecting the higher costs of imported goods that now have to be paid for with Mr Chavez's devalued bolivars.
Recession prolonged
These heavy-handed measures have steadily brought more of the Venezuelan economy under state control, but they have not done anything to promote economic growth.
While most of the country's Latin American neighbours are leaving the global recession behind, Venezuela is still bogged down in the financial mire.
 Mr Chavez's predecessor Rafael Caldera died on Christmas Eve |
The country's central bank has estimated that the economy shrank 2.9% in 2009.
And according to the International Monetary Fund, Venezuela is set to be the region's worst performer in 2010, with a projected contraction of 0.4% in a year when Latin America as a whole is expected to grow by 4%.
Oil, as ever, is still the mainstay of the Venezuelan economy.
In fact, it is responsible for more than 90% of the country's foreign currency inflows and 50% of government revenues.
The devaluation is therefore good news for the state oil company, PDVSA, which will now see the value of its petrodollars soar in bolivar terms.
That will translate into higher oil receipts for the government, helping to plug a hole in its finances.
Inflation ignored?
But the whole exercise leaves Venezuela's fundamental economic problems untouched.
As the respected survey organisation Consensus Economics puts it: "Price controls have done little to cap price increases and the authorities have refused to tackle underlying reasons for high inflation, most likely because this would conflict with the state's socialist agenda."
That may be unduly harsh. Brazil, for one, has shown that it is possible to combine left-leaning politics and social welfare programmes with a tough anti-inflationary stance.
But unlike Venezuela, Brazil realised as far back as the early 1990s that inflation hurts the poor most of all, because richer citizens can always find investment opportunities that mitigate its effects.
Unless Mr Chavez takes a similar view, he may find that his main support base will become rapidly disillusioned with his administration.
Monday, January 18, 2010
Cord blood stem cell transplant hopes lifted
Cord blood stem cell transplant hopes lifted
 Matching donors cannot always be found, despite extensive registries |
A technique which may eventually remove the need for matched bone marrow transplants has been used in humans for the first time.
It is hoped that "master cells" taken from umbilical cords could be used on any patient without rejection.
The latest advance, published in the journal Nature Medicine, greatly multiplies the tiny number of cells from the cord ready for a transplant.
UK charity Leukaemia Research said this could be the "holy grail" for doctors.
Aggressive treatment
The current system of bone marrow transplantation helps patients who have diseases, such as leukaemia, which affect the stem cells in their bone marrow where new blood cells are grown.
| The holy grail is to have an "off the peg" source of unlimited numbers of "neutral" stem cells Dr David Grant Leukaemia Research |
Their own bone marrow cells are killed off by aggressive treatment and cells from a matched donor are introduced in their place.
However, a matching donor cannot always be found, despite extensive donor registries held by organisations such as the Anthony Nolan Bone Marrow Trust and, even with a carefully matched donor, there is still a risk that the patient's body will reject the new cells.
Cells extracted from umbilical cords could overcome these problems - they do not have the characteristics which would normally trigger immune rejection, so it is likely that cells from a single baby's cord could be used in any patient, without the need for matching.
However, there is one big disadvantage - there are not enough cells in a single cord to meet the needs of an adult patient.
Scientists have been looking for ways to either combine the cells from more than one baby, or to "expand" the cell numbers in the laboratory.
The second of these options is far from straightforward - simply allowing the stem cells to divide and increase in the laboratory means that many of the resulting extra cells will be simple blood cells, which do not have the ability to produce new cells themselves.
Quick to work
Researchers at the Fred Hutchinson Cancer Research Center in Seattle believe they may have found a way.
They manipulated a "signalling pathway" in the stem cells to trigger an increase in numbers without losing their stem cell status.
After success in laboratory animals, these cells were used in human patients, and the researchers found that they were accepted by the body more quickly and contributed more to the rebuilding of functioning bone marrow than "non-expanded" cord blood transplants.
Dr David Grant, Scientific Director of charity Leukaemia Research said: "The holy grail is to have an 'off the peg' source of unlimited numbers of 'neutral' stem cells which can be given to any patient safe in the knowledge that they will not cause the very difficult 'graft versus host' problems that lead to rejection and often the death of the patient.
"This is a promising development towards this because the concern has been that once stem cells start 'growing' they lose their stem cell properties and progress to ordinary blood cells with a very limited lifespan."
Henny Braund, chief executive of The Anthony Nolan Trust, said the potential for umbilical cord blood was "huge", and that the charity had already imported well over 250 units of umbilical cord blood.
"Sadly in the UK, despite our scientific expertise, umbilical cord blood is still very much an untapped resource and we are only able to collect and store a tiny amount of the cords we need.
"We really need a properly resourced UK cord blood collection programme.
"Further investment is crucial if we are to capitalise on this amazing resource and save more lives."