|
A.
A New Mars Explorer to Launch in 2003
Narrator:
This is Science Today. NASA's plan to launch a robotic
Mars rover in 2003, will mark the longest scientific
exploration ever undertaken across the Martian surface.
Biochemist Mark Thiemens, of the University of California,
San Diego, developed a new way to interpret the
make-up of martian meteorites and is looking forward
to studying new samples.
Thiemens: We can certainly continue in analysis
of other of these Martian meteorites that come from
different times, but we really need return samples
- carefully controlled and from areas where you
might really get at the information you need. That
you can go down to the precision and determine where
your samples come from, rather than random events.
Narrator: Thiemens and his group developed
a way to use isotopes to fingerprint chemical processes
in Martian meteorites, which can help scientists
unravel the history of the red planet - including
signs of past life.
Thiemens: The meteorites we get and analyze
have come from different times in Martian history,
so by looking at those, one has sort of a snapshot
of what happened over time in the Martian atmosphere.
Narrator: For Science Today, I'm Larissa
Branin.
The
Role of Brain Imaging in Detecting Alzheimer's Disease
Narrator:
This is Science Today. Methods currently used to diagnose
Alzheimer's Disease have limitations and that's why
a new imaging technique developed by researchers at
the University of California, San Francisco, may fulfill
a great need. Dr. Michael Weiner, used a method called
magnetic resonance spectroscopy to detect Alzheimer's
by measuring certain brain chemicals associated with
the disease. Weiner says brain imaging may have an
important role in early detection.
Weiner:Because aside from imaging, the way
that a physician assesses a patient is largely through
interviews, psychological testing and neurological
examination.
Narrator: But Weiner says a patient's cognition
and memory can be affected by a number of factors,
including being distracted or depressed by life events
- which often occur in the elderly.
Weiner:
So it's important to have a test that really tells
you what's going on in the brain. And that's the beauty
of imaging, because it doesn't depend on the patient's
attitude or mood or cooperation. You can measure the
structure of the brain, you can measure the amount
of brain tissue and you can measure various chemicals
in the brain.
Narrator: For Science Today, I'm Larissa Branin.
C.
Exploring Gender Differences Found in Touch
Narrator: This is Science Today. There are
major differences in how men and women respond to
touch, starting from infancy to old age. Dr. Sandra
Weiss, of the University of California, San Francisco
has studied how touch influences the early neurocognitive
development of infants, as well as how therapeutic
touch can help patients with heart disease. In all
cases, she notes differences in males and females.
Weiss:Females are much more sensitive to touch.
It seems as if boys need a lot more strong intensity
touch in order to have the kind of impact that we
might see girls have from touch.
Narrator: Weiss is currently studying how touch
can enhance the development of low birth weight babies.
.
Weiss: Low birth weight babies are very vulnerable
because often their brains are not fully developed
at birth. And also, their central nervous systems
are highly responsive to stimulation in the environment.
And so they have a tendency to react strongly to touch,
as well as certain other kinds of things like sounds
in their environment.
Narrator: For Science Today, I'm Larissa Branin.
D.
Changing the Rules of Physics
Narrator:
This is Science Today. There are two important
components to light - an electric field and a magnetic
field. When light is propagating, these fields are
ninety degrees away from the direction the light is
moving. Dave Smith, a physicist at the University
of California, San Diego has recently helped come
up with a material that reverses the normal direction
of this flow.
Smith: There's a rule that says if you take
your hand and move your fingers from one of the fields
to the other field, you point in the direction that
the wave is moving.
Narrator:This physics rule is known as "right-handed"
- but Smith and his colleagues recently developed
a novel material that displayed "left-handed" properties.
Smith: As an example, if you drop a stone in
water, you'll see ripples moving away from where you
dropped it in the water. That's what would happen
in normal, right-handed medium. If it's left-handed
medium, you drop the stone in the water and you see
ripples appearing to come backward, even though energy
really is propagating outward. It's just something
of an illusion.
Narrator: And it could someday open up a new
wave, so to speak, in wireless communications. For
Science Today, I'm Larissa Branin.
E.
A New Sealing System for Homeowners
Narrator:
This is Science Today. An efficient and innovative
way to seal leaky air ducts may save homeowners hundreds
of dollars a year in energy costs. Mark Modera, a
staff scientist at the Lawrence Berkeley National
Laboratory, devised a novel way to seal leaks in heating
and cooling ducts by injecting vinyl acetate, an airborne
sealant, directly into a pressurized system.
Modera:
Think of it as really tiny pieces of caulking. We've
basically made like caulking mist - a powder of caulking.
When it dries it stays flexible, sort of dries like
caulking and so you can build a bridge from the far
side of the leak across to the other side of the leak.
Narrator: Unlike the more laborious task of
repairing leaks from the outside, this internal, airborne
sealing system is done in about an hour and is even
tracked by computer while at work.
Modera: So you can essentially watch your duct
system be sealed and then when it's done it'll print
out a little certificate that'll show the homeowner
exactly what was done to their duct system.
Narrator: Modera says the system is just starting
to catch on commercially. For Science Today, I'm Larissa
Branin.
|
