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A.
The Danger of Sports Related Concussions
Narrator: This is Science Today. Each year
there are about 300 thousand sports-related concussions
in this country - about a third of them occurring
on the football field. But it hasn't been until
fairly recently that doctors realized even getting
knocked around without losing consciousness can
injure the brain. Martin Holland, a clinical professor
of neurosurgery at the University of California,
San Francisco says researchers now also realize
that one concussion increases the chances of getting
a second one, which can lead to second impact syndrome.
Holland: The post-concussive syndrome after
second impact injury can be more severe. The recovery
after the second injury is longer. That's one of
the reasons why we don't want to let athletes go
back too soon, because this is well established,
especially in the younger populations.
Narrator: Studies in the past found more
than half of high school football players returned
to the game the same day as a loss of consciousness.
Holland: We have to educate - educate trainers,
educate coaches, educate parents and educate the
players themselves in terms of somebody should realize
'look, I've just got my bell rung, I'm gonna stay
out of the next couple of games.'
Narrator: For Science Today, I'm Larissa
Branin.
B.
The Risk of a Global Society
Narrator:
This is Science Today. Since tuberculosis is rampant
in much of the developing world and immigration from
these countries to the U.S. is at an all-time high,
public health officials have called for large-scale
TB screening programs in cities with large immigrant
communities and at national borders. Joel Ernst, an
infectious disease specialist at the University of
California, San Francisco says tourism has also caused
a resurgence of TB in this country.
Ernst: And so as we become a globalized human
population, the exposure and the likely risk of tuberculosis
is substantially greater than when we were largely
staying at home on the north American continent.
Narrator: Although the development of anti-tuberculosis
antibiotics in the Fifties caused TB to fall from
the American consciousness, it never really went away
in the rest of the world.
Ernst: In the developing world, tuberculosis
is still incredibly prevalent and at least an estimated
three million people a year die of tuberculosis. So
this is really a disease that never really went away.
Narrator: For Science Today, I'm Larissa Branin.
C.
A Stimulating Treatment for Depression
Narrator: This is Science Today. A device used
to treat epilepsy has been found to benefit some patients
with severe depression. In a recent study, doctors
used a pacemaker-like device called the vagus nerve
stimulator to send pulses of electricity to the brain.
It lifted the mood of about 40 percent of severely
depressed patients. Dr. Evelyn Tecoma, of the University
of California, San Diego was not part of this study,
but she's been working with this device to treat epilepsy
since 1993.
Tecoma: There are two components to the vagus
nerve stimulator. There's a pulse generator, which
is implanted in the chest wall. It's about the size
of a small pocket watch and it is implanted in the
chest wall much like a cardiac pacemaker.
Narrator: From there, several wires under the
skin travel up to the neck and are attached to the
vagus nerve, which is near the carotid artery.
Tecoma: It's a device that can be programmed
to deliver the stimulus at intervals. So, it's not
on all the time - it comes on periodically.
Narrator: As a possible treatment for depression,
the results were very encouraging but more study is
needed. For Science Today, I'm Larissa Branin.
D.
A Call for Low Dose Medical X-rays
Narrator: This is Science Today. A radiation
expert is calling for the reduction of radiation doses
in standard, medical x-rays. Dr. John Gofman of the
University of California, Berkeley, recently released
a study suggesting that the overuse of medical x-rays
are responsible for a large proportion of cancer and
heart disease deaths. One solution, he says, is to
consistently lower dosage.
Gofman: The dose of medical x-rays for a given
procedure - let's say a GI series - in one place gives
you ten units of dose, in another place, it gives
you one unit of dose. That's an outrage! There should
never be a place giving you any more dose than the
dose needed to give a good diagnosis.
Narrator: Gofman hopes public outcry will bring
about the major changes made in mammography during
the late Seventies. Doses were up to thirty times
higher then - until there was mass criticism.
Gofman: That killed mammography temporarily,
but the people interested in mammography went to work
on it and today, the dose is down about twenty times
on the average.
Narrator: For Science Today, I'm Larissa Branin.
E.
Designing Transistors of the Future
Narrator: This is Science Today. Researchers at
the University of California, Berkeley have developed
the tiniest semiconductor transistor yet, paving the
way towards faster and cheaper electronic devices.
But Chemning Hu, one of its creators, says the current
state of the semi-conductor industry is still alive
and well.
Hu:
We actually think it will be at least ten years for
this transistor to find its way into consumer or any
real applications. The fact is that the present technology
will continue to have several generations of life
left in it.
Narrator: Hu says another reason their new
transistor will not be implemented right away is that
the semiconductor industry believes in incrementalism.
Hu: If you want to make a billion transistors
on the chip to work, everyone to work, you'd better
choose a technology that you know very well - not
something that you just discovered last year. Because
of this incrementalism, the semi-conductor industry
is going to take a very, very cautious approach to
adopt any new transistor designs.
Narrator: For Science Today, I'm Larissa Branin.
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