Archives for March 2009

Not only do crabs and lobsters feel pain, they can remember it, and amend their behaviour as a result.

That's according to the latest research by scientists at Queen's University Belfast, who have been studying the reactions of hermit crabs to a series of electric shocks.

The finding overturns conventional wisdom: which holds that crustaceans like crabs, shrimps and lobsters can't feel pain because they don't have the highly developed central nervous system necessary to process the information.

It was known that crabs could detect harmful environmental stimuli and move away from the source, but that was not thought to involve the inner "feeling" of unpleasantness we associate with pain.

Hermit crabs have no shell of their own, but make their homes in abandoned mollusc shells. Professor Robert Elwood attached wires to a series of shells, delivering small electric shocks to the hermit crabs inside.

The only crabs to get out of their shells were those that had received shocks, indicating that the experience was unpleasant. But crabs were also more likely to abandon inferior shells, leading Prof Elwood to conclude that neuronal processing was occurring rather than a simple reflex response.

When offered a new shell some time later, shocked crabs were also much more likely to change - indicating that they retained some memory of the experience.

It's bad news for seafood lovers, who may have to think again about boiling crabs and lobsters alive.

Take a good look at these pictures.

It could be you're looking at the first evidence that liquid water is present on the surface of Mars. If that's right then life - at least in bacterial form - could well be there too.

The images come from the Phoenix Lander, and appear to show liquid droplets scattered along one of its supporting struts. But what's got Dr Nilton Renno, who's a co-investigator on the Phoenix Mission and professor of Astronomy at the University of Michigan, so excited is the way the droplets seem to run in rivulets through the sequence of pictures.

He's convinced the liquid is forming a droplet, and that the reason it suddenly vanishes is because it has dropped back to the surface. It adds up to overwhelming evidence, Dr Renno believes, that water exists in liquid form in the surface layers of the Martian soil.

Others are not so sure. Dr Michael Hecht from NASA's Jet Propulsion Laboratory says there are other simpler explanations for the bumps and blobs on the Phoenix's struts. And he says Dr Renno's explanation for why the water hasn't frozen - that it's contaminated with perchlorates, or salts that are acting like antifreeze - is flat out wrong.

What raises this above the level of an arcane dispute between academics are the stakes. We've known for some time that ice may be present beneath the surface of Mars, meaning that life might have been possible in the dim and distant past. Liquid water raises the possibility that bacterial life could survive on the surface of the red planet today.

We still don't know if there is life on Mars, but liquid water means it is at least possible.

Just how special is planet earth?

It's a question that's been asked since people first raised their eyes to contemplate the stars, one which touches on the most profound issue of existence: are we alone in the universe?

It's a question NASA's Kepler Space Telescope - which blasts off from Cape Canaveral tomorrow - hopes to answer.

It's the space agency's first mission capable of finding earth-like rocky planets around distant stars. For the next three-and-a-half years Kepler will stare, unblinking, at a small patch of the Galaxy (actually incorporating some 100,000 stars between Cygnus and Lyra) waiting for the tell-tale dip in brightness as orbiting planets pass in front of them.

Bill Borucki, the principal Investigator on Kepler at NASA's Ames Research Centre, hopes to find hundreds of earth-like planets, and dozens in the habitable or "Goldilocks" zone, that's neither too hot nor too cold to support life.

"Although Kepler will not find ET we are hoping to find ET's home," he says.

If that sounds too good to be true, others are even more optimistic. According to the author of Crowded Universe:The Search for Living Planets, Alan Boss argues that earth-like planets may be the norm rather than the exception.

Extrapolating from the data we already have from ground-based telescopes, and combining that with what we know about the processes of planetary formation, Boss comes up with a figure of 10,000 billion billion earth-like rocky planets in the observable universe.

It has to be said that few at NASA are quite as optimistic as Alan Boss. But even if the Kepler Space Telescope only spots one tiny pale blue dot spinning round a distant star, that will still be pretty exciting.

Revolutionary breakthroughs - particularly when it comes to medical science - do seem to pop up with increasingly monotonous regularity.

So much so that you could be forgiven for assuming that there was nothing particularly revolutionary about the latest stem cell breakthrough reported today in the journal Nature Online.

But for once the hyperbole may be warranted. At a stroke this research sidesteps one of the most profound obstacles to the use of stem cells in human patients, AND signals an end to the use of cells derived from human embryos. Something of a double whammy as revolutionary breakthroughs go.

The research, by scientists at the MRC's Centre for Regenerative Medicine at the University of Edinburgh, builds on the work of American and Japanese researchers who announced a new way to reprogramme adult cells, returning them to something like their embryonic state, last year.

The technique involved the use of viruses to transform the cells, but that modified their DNA, leading to an increased risk of cancer. As a result these IP, or Induced Pluripotent stem cells, could never have been transplanted into a human patient.

Now the Edinburgh team, led by Dr Keisuke Kaji, has found a way to reverse the DNA modification associated with the use of viruses in cell reprogramming. It means that IP stem cells - ones derived from an adult cell rather than an embryo - can now be used in the development of future treatments.

Those treatments may still be a long way off - perhaps as much as ten years according to the head of the Edinburgh Centre, Professor Ian Wilmut. But the development of a technique to generate stem cells that does not rely on the destruction of a human embryo is one he warmly welcomes.

"This is the opening of a new era in biomedical research which over a period of time will provide treatments for some at least of the diseases which we cannot treat at the present time," he says.