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A.
September is National 5 A Day Month
Narrator:
This is Science Today. September is designated as
National 5 A Day Month in an effort to encourage
Americans to eat five to nine servings of fruits
and vegetables a day. If five to nine servings seem
too difficult to achieve in a day, consider what
actually makes up one serving. Cheryl Rock, a family
and preventive medicine professor at the University
of California, San Diego, explains.
Rock:
For chopped vegetables or chopped fruit or
cooked vegetables, it's a half-cup. Leafy green
vegetables, a serving would be one cup and for juices,
general a half-cup is considered a serving from
juice.
Narrator:
Rock says in her studies, she's found people also
assume that servings of fruits and vegetables have
to be fresh or organically grown.
Rock:
Even canned fruit has some benefit in the fruits
in the can and if you rinse off the syrup or buy
the fruit without the syrup, it can end up being
very nutritious.
Narrator:
As the current 5 a Day campaign stresses, making
sure your selections are colorful is a fun and easy
way to increase variety. For Science Today, I'm
Larissa Branin.
B.
The Benefits of Computerized Climate Models
Narrator:
This is Science Today. Using computerized climate
models, scientists at the Lawrence Livermore National
Laboratory are able to conduct experiments on the
atmosphere, the oceans and their interactions using
very complex computer codes.
Santer: And with the benefit
of such models, one can perform experiments where
you change some of the things that you know affect
climate - the sun's energy output, volcanoes, greenhouse
gases, sulfate aerosols, ozone and you see how the
model climate system responds.
Narrator:
Ben
Santer, a scientist at the Lab's Climate Model Diagnosis
and Intercomparison Program, says these simulations
would be impossible without modern technology.
Santer:
We relied on something like twenty-eight climate model
experiments, each one of those experiments was 110
years in duration - this is simulated climate, so
these 28 runs start roughly in 1890 - so that's 110
years of simulation times 28 experiments!
Narrator: For Science Today, I'm Larissa Branin.
C.
Can Breastfeeding Lessen the Onset of Childhood Obesity?
Narrator:
This is Science Today. Human health care scientists
are looking into whether or not breastfeeding is an
effective method for later managing childhood obesity.
Nutrition specialist Lucia Kaiser of the University
of California, Davis, explains.
Kaiser:
Eight of eleven different studies show that there
is a significant relationship between breastfeeding
and a lower risk of being overweight in childhood.
Those children that were breastfed were thirty-four
percent less likely to be overweight when they were
followed up later than children that had been given
formula when they were babies.
Narrator:
Kaiser says one of the theories for this may be that
it's nature's system of self-regulation.
Kaiser:
In some cases, breastfeeding over a longer period
of time seems to be more protective of overweight
- it may be that babies who are breastfed learn how
to self-regulate intake a little bit better than the
formula-fed infant. It could have something to do
with hormonal effects as well.
Narrator:
For Science Today, I'm Larissa Branin.
D.
A Program that Extends Aircraft Control to Increase
Safety
Narrator:This
is Science Today. Computer scientists at the University
of California, Berkeley, are deep in the predicament
of what's really safer, a fallible human or a fallible
machine? After September 11th, Professor Edward Lee
began working on a technology called "soft walls"
that extends aircraft control in order to reduce human
fallibility and increase safety.
Lee:
Most of the aircraft that are designed today use a
technique called fly-by-wire, which means that the
pilot does not directly mechanically or hydraulically
have any control over the surfaces of the aircraft
that control where the aircraft goes. So for example,
there's no mechanical linkage between the cockpit
and the flaps on the wings.
Narrator:
With "soft walls," the computer extends
its authority to override a pilot's decision by prohibiting
planes to enter virtual no-fly zones around potential
targets. The concept has caused some controversy.
Lee:
I believe, however, that this solution is probably
the best one.
Narrator:
For Science Today, I'm Larissa Branin.
E.
A Surprising Discovery Made on a Nanometer Scale
Narrator:This
is Science Today. As scientists shrink materials down
to the nanometer scale, they've found puzzling and
intriguing behaviors that promise many unforeseen
applications, especially in the semiconductor field.
Benjamin Gilbert, a University of California, Berkeley
physicist, describes his team's observation that nanoparticle
structures respond to environmental changes.
Gilbert:
We're looking at how these very small particles
differ from things we see all around us, and if you
drop a grain of sand in the sea, nothing really changes
about the grain of sand. It's just in a new environment.
The difference between these relatively large objects
and these nanoparticles is that in some situations,
you can drop them in different solution or a different
environment and they can change structure inside and
out. And that's really the unexpected and very interesting
observation we've made with these small nanoparticles.
Narrator:
Gilbert's
team is currently looking at ways to control semiconductor
structures. For Science Today, I'm Larissa Branin.
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