----- Original Message ----- From: [EMAIL PROTECTED] Sent: Monday, September 16, 2002 12:17 PM To: [EMAIL PROTECTED] Subject: Unidentified subject! John Bluck
Sept. 16, 2002
NASA Ames Research Center, Moffett Field, Calif.
Phone: 650/604-5026 or 604-9000
E-mail: [EMAIL PROTECTED]
RELEASE: 02-101AR
TINY CAMERA OBSERVES WORMS SPINNING AT 100 TIMES EARTH'S GRAVITY
Enduring spinning forces that would kill a human being, tiny worms
are being observed by a student-designed video system in NASA studies
seeking to explore how life adapts to gravity beyond Earth.
Miniature worms, only 1 millimeter long and so small they are hard to
see with the naked eye, are being spun in a centrifuge for as long as
four days -- at forces of 20- to100-times that of Earth's gravity (1
G). In contrast, human pilots not wearing anti-G suits can black out
at as low as 3 Gs, and prolonged exposure at higher Gs can be life
threatening. To examine the worms as they spin, scientists are using
a video system designed and constructed by students at Harvey Mudd
College, Claremont, Calif. The studies are taking place at NASA Ames
Research Center in the heart of California's Silicon Valley.
"By looking at what changes occur in the worms when they transition
from high-G forces to normal gravity, we think we can predict what
will happen to them when they experience near weightlessness during
space flight," said principal investigator Catharine Conley, a
biologist at NASA Ames. "In the future, we want to fly the worms in
space, subjecting them to microgravity to see if our predictions are
correct." Microgravity is close to 'zero gravity.'
"Radiation levels in space are much higher than they are on the
Earth's surface," Conley said. "We know that elevated radiation
increases the mutation rate of living things. Because these worms
reproduce every four days, we can look quickly at many worm
generations in space to see how radiation and microgravity may cause
changes later," she explained.
"Worms have already flown aboard the space shuttle, and it was found
that they went through several generations without gross structural
changes to their bodies," Conley said. "We want to test the gene
expression in worms that have flown in space versus those that have
not, to see if changes in worms are similar to changes seen in
vertebrates that have experienced space flight." Expression is how a
gene affects a characteristic such as eye color, or susceptibility to
a disease or condition.
During preliminary tests, scientists spun the 1 mm worms (technically
known as Caenorhabditis elegans, a soil-dwelling nematode worm) in a
large 20-G centrifuge at NASA Ames for four days, but they could see
what happened to the worms only after the centrifuge, designed to
carry human passengers, stopped. At 20 Gs, the worms are subjected to
forces that are 20 times their normal weight.
"Should our hypothesis prove correct, it will validate
Caenorhabditis elegans [nemotode] as an extremely useful and
cost-effective model organism for studying responses to space flight
at the molecular, genetic and whole-organism levels," Conley said.
When Conley was planning her current experiments that utilize a
smaller, desktop centrifuge, she realized she would need a camera no
bigger than an ice cube that could broadcast signals from the
spinning apparatus to a TV monitor and recorder in real time. So she
turned to the Student Engineering Clinic at Harvey Mudd College to
produce the camera system. Five Harvey Mudd students spent an
academic year on the project. They bought off-the-shelf components,
but they had to overcome several engineering challenges to enable the
system to work well.
"The camera had to be supported to withstand the 100-Gs force," said
Professor Joseph King, director of the clinic. "All this stuff is
designed so it is compatible with the geometry of the centrifuge."
The equipment also has two broadcast systems, an infrared system to
control the camera, and a wireless, video transmission system to
broadcast movies of the worms.
"During spinning there are changes in the worms' gene expression that
seem to help them compensate for the increased apparent gravity,
allowing them to survive," Conley said. The worm has about 19,000
genes, and it has nerves, muscles and some of the same types of
organs in people that are affected by weightlessness.
Astronauts can suffer from motion sickness, bone loss, muscle
degeneration (atrophy) and blood vessel problems during
weightlessness. "By studying how the worms produce different levels
of proteins that help the tiny organisms cope with high-G situations,
we think we eventually can develop treatments, perhaps even oral
drugs, for astronauts to serve as countermeasures to problems due to
weightlessness."
After the worms endure high G forces riding in a centrifuge, the
animals' behavior alters. That is part of what the scientists look
for to find out how the creatures handle changes in gravity's force.
Normally, under 1-G conditions, the miniscule creatures look like
small, clear wiggly rods that swim snake-style through a thin layer
of water and nutrients in which they live in a laboratory
environment. The worms commonly are found in soil and rotting
vegetation, and have about a thousand cells.
In addition to Conley's work, the Harvey Mudd Student Engineering
Clinic program was involved in about 40 projects from various
companies, institutions and sponsors this year. During past years,
the clinic has participated in about 10 NASA projects, according to
King.
King may be reached at this e-mail address: [EMAIL PROTECTED] More
information about the clinic is available on the World Wide Web at:
http://emat.eng.hmc.edu
Conley's research is detailed on her Web site at:
http://lifesci.arc.nasa.gov/conley/home
The NASA Fundamental Biology program and the NASA Astrobiology
Institute fund the worms-in- space project. Life sciences research at
Ames is supported by NASA's Office of Biological and Physical
Research, which promotes basic and applied research to support human
exploration of space and to take advantage of the space environment
as a laboratory. More information is available at:
http://spaceresearch.nasa.gov/
Publication-quality images related to this release can be found at:
http://amesnews.arc.nasa.gov/releases/2002/02images/worms/worms.html
-end-
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