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A.
A Center Devoted to Nature's Grandest Explosions
Narrator:
This is Science Today. A team of astrophysicists
and computer scientists are working to better understand
the mechanics of massive exploding stars known as
supernovae. The group is part of a newly established
Center for Supernova Research at the University
of California, Santa Cruz. Stan Woosley, a professor
of astronomy and astrophysics, directs the center
and describes a supernova as nature's grandest explosion.
Woosley:
It's the death of a star - a star only becomes a supernova
once. The sun will never become a supernova, it's
too small, too light. But stars over about eight times
the mass of the sun are able to live a very fast life
as very bright stars and then die in this dramatic
explosion called the supernova.
Narrator:
Despite their prominent role in astronomy, there's
still a lot about supernovae that researchers don't
know.
Woosley:
We like to understand supernovae not only because
they're marvelous explosions with a lot of interesting
physics, but because they make the elements of which
we are all comprised and also because if we understand
them, we can use them better to study other aspects
of the universe.
Narrator:
For Science Today, I'm Larissa Branin.
B.
Law Enforcement Seeks Training in Lie Detection Techniques
Narrator:
This is Science Today. Law enforcement officers depend
on their ability to know when people are telling the
truth. So in order to improve their skills, some agencies
have solicited help from Doctor Paul Ekman, a psychology
professor at the University of California, San Francisco.
Ekman: We try to teach people
what are the various clues in the voice and in the
speech itself that can give them a better sense of
how the person they're dealing with is feeling at
the moment and where they need to ask more questions,
where there are signs that they're not getting the
full story.
Narrator: Ekman says officers often
have poor judgment.
Ekman:
Our studies of police interrogators show that most
of them can't tell from demeanor - from how someone
behaves - whether they're telling the truth or not.
Narrator:
:
But Ekman says after just 12 hours of training, officers
can dramatically improve their abilities. But repetition,
he says, is key.
Ekman:
You can benefit from reading about it, just like you
can learn a lot about the game of tennis by reading
about it. But you're not going to get the ball over
the net without practice.
Narrator:
For Science Today, I'm Larissa Branin.
C.
New Chemicals Prevent Brain Cell Death
Narrator:
This is Science Today. Researchers at the University
of California San Francisco have discovered that chemicals
found in a Japanese flower and green tea leaves can
prevent brain cells from dying in stroke-like conditions.
Doctor Raymond Swanson, a neurology professor at the
school, says that when brain cells are damaged, they
often over-exert themselves by trying to repair their
structure.
Swanson:
And of course under a stroke situation, that
is the problem. There's not enough energy for the
cells to live. And when that's compounded by a massive
effect of repairing DNA, it kills cells that might
otherwise live.
Narrator:
The new chemicals, Swanson says, prevent cells from
wasting much needed energy in the repair process --
and that may prove vital in a life or death situation.
Swanson:
If you have a dead cell in the brain, you can't do
any worse than that. So if you buy time, you may find
yet other interventions, which can make these cells
live. If you buy time you may be able to improve blood
flow to the brain.
Narrator:
For Science Today, I'm Larissa Branin.
D.
Old Mines Are A Major Source of Mercury Contamination
Narrator:
This is Science Today. Mercury has recently been recognized
as a major environmental concern because concentrations
of mercury once considered safe are now known to cause
neurological damage. Russ Flegal, an environmental
toxicologist at the University of California, Santa
Cruz, says one of the reasons controlling levels of
mercury is so difficult is because mercury is so volatile
as a gas.
Flegal:
Large amounts of mercury are found in fossil fuel
products so when they burn coal, that puts a lot of
mercury into the atmosphere. So recently in the United
States, they've gone at great lengths to control mercury
emissions from coal production.
Narrator:
Flegal says it used to be thought that simply plugging
up openings to abandoned mercury mines could do this.
Flegal:
But
when they process mercury, they take the ores out
and they heat them - they volatize whatever mercury
they can and they push the slag rock over the hill,
and that slag is essentially pure mercury sulfite
anyway and so when it's exposed to the environment,
it continues to release mercury.
Narrator:
For Science Today, I'm Larissa Branin.
E.
Acute Seizures Demand Medical Attention
Narrator:
This is Science Today. Seizures occur when the brain's
neurons misfire, frequently causing abnormal movement
and behavior in the human body. When a seizure happens,
the brain can often return to its normal functions
rather quickly - usually in less than a minute. But
as Doctor Brian Alldredge, a neurology professor at
the University of California at San Francisco points
out, sometimes the brain is unable to respond.
Alldredge:
In some cases, either when people have epilepsy or
people have an insult to the brain that causes their
first seizure in their lifetime, the normal brain
functions that stop seizures cannot be present, or
the extent of the injury is so big that the brain
can't stop the injury by itself.
Narrator:
If a seizure lasts for much longer than a minute,
Alldredge says the situation can be life threatening.
Alldredge:
And when it starts to last three, four, five minutes
and longer than that, it becomes what we call an acute
seizure or an emergent seizure - something that requires
emergency medical attention.
Narrator:
For
Science Today, I'm Larissa Branin.
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