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A.
Genetic Evidence of Immune System Counter Attack
in Viral Warfare
Narrator:
This is Science Today. Viruses are very tricky and
exist for one purpose only - to reproduce. To do
that without being foiled by the immune system,
they have rapidly evolving evasive strategies. But
it seems the immune system can be just as tricky
in their counter-attacks. Dr. Lewis Lanier of the
University of California, San Francisco, discovered
the first genetic evidence of the embattled immune
system's attack against viral invaders.
Lanier:
These viruses we've come to find out will make essentially
decoys or proteins that will turn the immune system
off. What does the immune system do to counteract
that?
Narrator:
Lanier found in the lab that the immune proteins that
were manipulated by masquerading invaders were able
to evolve by mutating to the point where the immune
cells could recognize the virus and create a new receptor
to prevent attacking itself.
Lanier:
So it has no chance of being deleterious and causing
active attack against self. We think this is just
the first example of a common event in the immune
system where you have this back-and-forth between
pathogens and a host. It's an ongoing, constant battle.
Narrator:
For Science Today, I'm Larissa Branin.
B.
'Smart Bomb' Therapy Gets a Boost
Narrator:
This is Science Today. 'Smart Bomb' therapy for cancer,
in which antibodies are used to carry doses of radiation
directly to tumor cells, is getting a boost from researchers
at the University of California, Davis. Dr. Claude
Meares and his team have developed a new method to
permanently bind the smart bomb treatment to antibodies.
Meares:
The small molecule that targets cancer has to stay
stuck on the cancer cell permanently or preferably
permanently. And we have found a way to do that -
engineering the receptor that would catch this small
radioactive molecule and also, synthesizing an appropriate
set of molecules that would go together permanently
once they ran into ran into each other, but would
not stick to anything else.
Narrator:
And by having such a direct target, normal
tissue can be spared.
Meares:
This
new approach delivers radiation to the cancer and
not to other normal cells in the body much more efficiently,
so we're very excited about its future.
Narrator:
For Science Today, I'm Larissa Branin.
C.
Tool Use Among Asian Elephants
Narrator:
This is Science Today. Although Charles Darwin alluded
to tool use by elephants and the author Rudyard Kipling
observed it, no one had followed up on these observations
until recently when a team of University of California,
Davis researchers studied this phenomenon. Animal
behaviorist Lynette Hart says they discovered an Asian
elephant would take a branch and effectively use it
as a fly switch.
Hart:
And she will do this intelligently - that is, when
there are more flies around, she will do more fly-switching
with it. And it does actually reduce the fly abundance
around her and these are bloodsucking flies in Asia,
so they're quite serious.
Narrator:
Hart says this reflects the tremendous brain capacity
of the Asian elephant.
Hart:
We don't really know exactly what uses elephants are
making of this extraordinarily large brain, but this
could be one of the uses - that they are intelligently
making tools.
Narrator:
Asian elephants have the greatest volume of cerebral
cortex available for cognitive processing. For Science
Today, I'm Larissa Branin.
D.
Searching for Links between Gulf War Service and Disease
Narrator:
This is Science Today. The United States has spent
over 200 million dollars to find the cause of Gulf
War Illness, which is marked by common symptoms including
fatigue, muscle aches and some memory lapse. Dr. Michael
Weiner of the University of California, San Francisco,
who is studying Gulf War Illness, says one of the
problems with the syndrome is there's no test for
it.
Weiner:
There's no specific way to diagnose it. And there
have been a number of different biological findings,
but none of them has really been consistent, so there's
no diagnostic marker. The only way to identify somebody
as having Gulf War Illness is by asking them questions
and their giving symptoms of fatigue, tiredness, muscle
aches and pains …so forth.
Narrator:
Recently,
there have been studies indicating Gulf War veterans
are twice as likely to develop Lou Gehrig's disease,
or ALS, which is a neurological condition that destroys
brain cells and muscle movement. But the actual data
proving this is very limited.
Weiner:
We will look in the regions that are affected by ALS
and see whether those regions are associated with
the Gulf War symptoms.
Narrator:
For Science Today, I'm Larissa Branin.
E.
Facial Expressions Reveal the Root of Emotion
Narrator:
This is Science Today. During the course of a half-hour
conversation, it's not uncommon for a person to make
up to 300 different facial expressions. But Paul Ekman,
a psychology professor at the University of California,
San Francisco, says the three most common facial expressions
are non-enjoyment and enjoyment smiles and the raising
of eyebrows. Ekman is a leading researcher of facial
expressions.
Ekman:
We developed a technique almost twenty-five years
ago for measuring precisely movement off of videotape
or film. It allows us to specify which muscles have
moved and therefore, whether we're seeing an enjoyment
smile or a non-enjoyment smile. Some of the research
that we've done is to look at the difference in brain
activity.
Narrator:
Ekman's interest is to be able to index and understand
momentary changes in emotion.
Ekman:
And the face is still the best technique we have for
doing that. The voice isn't bad, but people aren't
always speaking, so you can't do the equivalent of
not speaking with your face. It's always talking,
if you like, and so it's a very good source of information.
Narrator:
For
Science Today, I'm Larissa Branin.
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