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A.
The Facts about Mercury Poisoning
Narrator:
This is Science Today. Mercury is similar to lead
in that high exposure causes neurological problems.
Mercury poisoning can also impair brain development
in fetuses and young children, leading to learning
deficits and other problems. Russ Flegal, a professor
of environmental toxicology at the University of
California, Santa Cruz, says the toxic effects of
mercury have been known for quite a while.
Flegal:
The Mat Hatter in Alice in Wonderland was mad because
they used mercury in making felt hats and so the history
of mercury as a toxin has been known for hundreds
of years. But the magnitude of mercury s a neurotoxin
has only been recognized at the low levels within
the past decade.
Narrator:
Because of this, there's been a lot of concern about
eating fish with higher levels of mercury - such
as swordfish, shark and tuna. Federal agencies suggest
eating these fish no more than once a week. Yet
Flegal says people shouldn't feel they need to stop
eating fish altogether.
Flegal:
Fish is a terrific source of protein and so
to say that people shouldn't eat fish, the disadvantages
of that may outweigh the advantages of getting that
protein source.
Narrator:
For Science Today, I'm Larissa Branin.
B.
Emergency Seizure Treatment Found to be Safe and Effective
Narrator:
This is Science Today. Paramedics often treat adult
patients suffering from seizures en route to the hospital
with drugs that can cause harmful side effects. But
Dr. Brian Alldredge, a neurology professor at the
University of California, San Francisco, conducted
a recent study that found early intervention is worth
the risk.
Alldredge: That's the crux of
the whole emergency nature of seizures. And what we
know, is that prolonged seizures can cause brain damage.
So the general rule is if a seizure lasts more than
five minutes, you want to act as quickly as possible
rather than wait thirty minutes before you're in a
clearly life-threatening situation.
Narrator: Alldredge says the study will
have an immediate impact on EMS services around the
country.
Alldredge:
I think a couple things will happen. One is that the
EMS systems around the country that currently use
this treatment I think will feel very good that we've
validated the treatment administered by paramedics
as both safe and effective.
Narrator:
For
Science Today, I'm Larissa Branin.
C.
Researchers Work to Improve Bioterrorism Detection
Systems
Narrator:
This is Science Today. As the recent spate of anthrax
attacks have proven, early detection is vital to subsequent
treatment. Researchers at the Lawrence Livermore National
Laboratory are working to further develop and improve
the very rapid diagnostic technology known as the
polymerase chain reaction, or PCR, test. Bert Weinstein
a biotechnology specialist at the Lab, explains.
Weinstein:
They've developed several generations with ever-increasing
speed and ever-shrinking size to the point that there's
now out for evaluation a hand-held PCR device that
will allow you to do four simultaneous samples and
that's out in the hands of users in a number of different
organizations - to get some feedback on its utility
and ways to improve it.
Narrator:
Weinstein says the ultimate goal is ongoing monitoring
for counter bioterrorism applications.
Weinstein:
You can think of that sort of ongoing monitoring going
on in hospitals and clinics, to see if there are any
bacteria floating around in the atmosphere that might
cause a disease outbreak.
Narrator:
For Science Today, I'm Larissa Branin.
D.
The Role of Female Choice in Animal Mate Selection
Narrator:
This is Science Today. It was Charles Darwin who first
wrote about female choice in animal mate selection,
but biologist Marlene Zuk of the University of California,
Riverside, says Darwin's idea of female choice did
not sit well with his contemporaries and the idea
of female choice dropped away for a long time.
Zuk:
It wasn't until I think pretty much the 1960s
that people started going back to this. The whole
point is, how many genes are you going to leave? You're
going to leave genes in the form of offspring - what's
going to make that happen?
Narrator:
For females of an animal species, that all depends
on how many offspring can be physically produced and
in many cases, reared.
Zuk:
But for the males, what they're limited by is the
number of females they can attract to mate with them.
And so because of that, you would expect males to
in general, compete for access to females because
the more they can get females, the more genes of theirs
are going to be left in the next generation.
Narrator:
Zuk is currently studying the importance of disease
resistance in animal evolution. For Science Today,
I'm Larissa Branin.
E.
Fine Needle Biopsies Regain Popularity
Narrator:
This is Science Today. Biopsies are routinely used
to identify breast and other cancers. Core and fine
needle are the two most widely practiced biopsy techniques
in the country. Both procedures use needles to extract
samples from the body, but Dr. Britt-Marie Ljung,
a pathology professor at the University of California,
San Francisco, says the core method is more invasive.
Ljung:
Core needle biopsy is a much larger needle that takes
a piece of tissue rather than a psydologic sample,
which is more like a couple of drops of liquid with
cells in it.
Narrator:
Ljung says the procedure is painful and can create
more stress for patients who are already worried.
Fine needle biopsies, she says, are much less traumatic.
Ljung:
It's a much smaller needle that can be placed inside
of a lump without local anesthesia. It's very much
like having a blood test taken. It takes only ten
to twenty seconds to collect the sample and so the
discomfort is very minimal from having this procedure
done.
Narrator:
For
Science Today, I'm Larissa Branin.
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