Thursday, 4 February 2010

NASA explores inner space

Learning how to walk again after long-duration space flights is a problem astronauts face as they readjust to Earth’s gravity. To learn how microgravity affects human space travelers, NASA scientists studied the nanomechanics of hair cells in the inner ear.

Their research may also help solve more down to Earth medical problems for ordinary people, such as motion sickness.

Using the toadfish (Opsanus tau) as their model, scientists tested whether hair cells amplify stimuli from very small head movements, and if so, can the brain regulate this enhanced sensitivity and shift this function on or off?

Test results showed that an organism’s ability to maintain equilibrium is regulated by hair cell sensory organs, including hearing organs.

“These hair cells are specialized mechanical sensors that are used to understand sound in the environment, and countermove the head for balance and coordination,” said Richard Boyle, a space bioscientist at NASA’s Ames Research Center, Moffett Field, Calif. “Understanding the fundamental physiology of the hair cell in the inner ear is critical to identifying the impact of spaceflight on an organism.”

Boyle is an author of “Mechanical amplification by hair cells in the semicircular canals,” scheduled for publication in the Proceedings of the National Academy of Science, this week.
The inner ear organs are designed and precisely attuned to changes in the environment: for the hearing organ, a change in the sound pressure, such as caused by a car horn, can deform the ear drum and rapidly lead to the recognition and location of the sound. For the balance organ, movement of the head, such as unexpectedly stepping off the curb, is sensed and rapidly leads to motor reflexes to maintain equilibrium. The more sensitive our ability is to detect these changes, the more acute our sensation. This remarkable tuning and amplification to detect the slightest stimuli, allows us to adjust our posture.

For large movements this amplification is not evident. It is over the very small head movements that the amplification process benefits our ability to sense movement. But this places the hair cell systems at the blink of instability.

Fortunately, the amplification process is not all-or-nothing, but actually controlled by the organism. According to the organism’s intended behaviour, this instability can be turned off through a pathway from the brain back to the inner ear organs. For example, during a large, self-generated movement of the head, as one rapidly turns to view the location of the car horn, the amplification process can be turned off.

Fossil evidence, dating from at least the Devonian Period 400 million years ago, shows that the elaborate sensory structures used to sense the organism’s movement are remarkably conserved among vertebrata. The results demonstrate an active process in the hair cells of an ancient bony fish, thus suggesting that the mechanism is ancestral, and may underlie the broad appearance of active hair cell processes in amphibians, reptiles, birds, and mammals, including humans.

During orbital missions, organisms on board the spacecraft are exposed to microgravity. Microgravity exposure causes severe disorientation or “space adaptation syndrome” for many human travelers, a condition similar to what we on Earth experience as motion sickness. The possible cause is a miscommunication of information provided by various sensory systems.

“A change in gravity has a profound effect on how organisms maintain coordination and balance,” said Boyle. “This information is essential to understanding the human condition on Earth, and may contribute to the science that will eventually lead to improved diagnostics and treatment of disorders, such as dizziness and motion sickness,” he added.

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Ex Astris Returns to Spaceship Away

The latest issue of Spaceship Away, the science fiction comics magazine inspired by and featuring the original Dan Dare, includes the first part of the Ex Astris strip “Homecoming”, set in the story’s 2511 time period, on an Earth devastated by both environmental and man made disaster.

The magazine has just gone to the printers and will be on sale in all its usual outlets, and online, soon.

Spaceship Away readers will soon realize that our latest episode of Ex Astris for the magazine is a very different beast to “Secrets of Ceres”, which ran in previous issues. This story, reflecting the huge scope of artist Mike Nicoll’s vision for the strip, is set in the 26th Century, at a point where Earth has long been a wasteland caused by a combination of environmental and other disasters, but humans are now fighting to reclaim their planet of birth from mysterious aliens and antagonistic descendants of the survivors of the world’s destruction some centuries previously.

While “Secrets of Ceres” is set before Earth is finally beset by disaster, Sarah Blake lives on in Katherine Blake in ‘Homecoming’, the all-action leader of an elite military squad aboard the Armstrong spaceship. Is she a direct descendant of Sarah, or are there other secrets yet to be revealed? More to the point, is Captain Charles Bryant the same Bryant followers of Ex Astris have seen in “Ceres” and “Return to the Moon” and, if so, how has he survived for almost five centuries?

Although the strip has been previously published – and was previously available online via myebook, where it achieved some 15,000 downloads – I’m looking forward to seeing it in Spaceship Away, simply because of the quality of the magazine. For us, the strip is a good fit with the science fiction vision of the Spaceship Away team.

The issue features a superb cover from veteran Dan Dare artist Don Harley, also continues two ongoing Dan Dare stories, “Green Nemesis” by Rod Barzilay and Tim Booth, and “The Gates of Eden” by Tim alone, a brand new Dare adventure strip, set a year and a half before “The Red Moon Mystery”.

“Garth: The Bubble Man” by Frank Bellamy, beautifully coloured by John Ridgway continues this issue, as does “Journey in Space: Planet of Fear” written by by Charles Chilton, and drawn by Ferdinando Tacconi.

Feature wise, there’s a report on the recent Spaceship Away day event and full information on Alistair Crompton’s new book on Dan Dare creator Frank Hampson, Tomorrow Revisited, out later this year. Graham Bleathman providea a cutaway of Dan Dare’s spaceship, the Anastasia, and there are some images of the original models used in the creation of the Dan Dare strip back in his original Eagle days, and an update on Day2Day Trading’s new Dan Dare action figure which we’ve reported on here.

To order the issue online visit: