A. The Link between Stress & Abdominal Fat in
Lean Women
Narrator:
This is Science Today. A new study
has found that lean women with chronic stress are
more likely to have an excess of abdominal fat.
Elissa Epel, a University of California, San Francisco
researcher who led the study, says stress produces
the hormone cortisol, which is linked to abdominal
fat accumulation.
Epel:
This
stress response is not harmful in itself and cortisol
in fact protects us from part of the stress response.
It's very healthy and important. The problem is
when stress becomes chronic, the cortisol itself
becomes harmful to our health and has negative direct
effects and one of these direct effects it can have
is increasing the abdominal fat and abdominal fat
itself plays a role in many types of disease.
Narrator:
Aside from serving as a warning
sign, Epel says this knowledge is a topic the diet
industry should pay more attention to.
Epel:
Because hormones have a lot to do with whether fat's
going to stay inside the cells or be mobilized and
be able to be burned off so that you can lose weight.
Narrator:
For Science Today, I'm Larissa Branin.
B.
The Most Distant Gamma-Ray Burst Ever Detectedn
Narrator:
This is Science Today. NASA's Ulysses
spacecraft recently detected the afterglow of the
most distant gamma ray burst ever observed. Research
physicist Kevin Hurley of the University of California,
Berkeley's Space Sciences Laboratory, was the principal
investigator of this experiment. Hurley says this
gamma ray burst originated from a gigantic dying
star more than 30 times larger than the sun, which
exploded 11 billion years ago.
Hurley:The
farther back you can look, the more interesting
it gets because the closer we're getting to the
Big Bang. So not only are we learning about what
went on in terms of the star formation in these
early galaxies, but we're also learning what the
early universe was like outside of those galaxies
between us and the galaxies.
Narrator:
If
these powerful explosions went off in our own galaxy
fairly close, it would be the end of civilization
on Earth.
Hurley:
So it's one more thing that you have
to think about when you think about life evolving
and in distant galaxies. Were solar systems subjected
to a gamma ray burst? Used to be all you had to
worry about was comet impacts and asteroid impacts,
but now there's something else. So these are the
sorts of things you learn when you study these distant
objects.
Narrator:
For Science Today, I'm Larissa Branin.
C.
Understanding Cellular 'Cross-Talk'
Narrator:
This is Science Today. When you think about how
a cell is constantly bombarded by chemical messages,
the big question is how are these messages ultimately
'heard' as a single command. Keith Yamamoto, chairman
of molecular and cellular pharmacology at the University
of California, San Francisco, says this puzzle raises
a real challenge.
Yamamoto:
How do two signals work together? How do four? How
do eighteen work together? And so the question of
physiology - and in the end, disease - is going
to come down to understanding how it is that multiple
signals work together, to give rise to what comes
out in the end in a particular cell that we're examining
or the particular cell that is in a disease state.
Narrator:
Yamamoto's lab recently deciphered
a chemical pathway that determines the survival
of immune cells.
Yamamoto:
There are specific things about the immune system
that we can take away from this bit of knowledge,
but as basic scientists, one of the more exciting
parts about it is not so much necessarily the application,
but that it gives us a way of thinking about how
the complexity can be built up.
Narrator:
For Science Today, I'm Larissa Branin.
D.
Lab Proposes More Durable Materials for Nuclear
Waste Storage
Narrator:
This is Science Today. Radioactive
waste decays over time and this poses long-term
storage problems because materials currently used
to encase radioactive waste are ultimately damaged
and are then susceptible to rupturing or leaching.
Scientist Kurt Sickafus of the Los Alamos National
Laboratory says one of the major limitations of
long-term storage has been the absence of a material
that is both chemically durable, as well as radiation-resistant.
Sickafus:
They need to be tolerant of the damage
that's introduced by the radioactive decay and this
is something that is a very difficult problem to
solve to have a material that's robust over very
long periods of time.
Narrator:
But researchers at the Los Alamos Lab have proposed
materials - a set of crystalline-ceramic oxides
- which appear to have a very high radiation tolerance.
Sickafus:
They
do appear very attractive. So you're essentially
relying on the high stability of these rock-like
oxides to hold your radioactive constituents and
keep them out of any environmental situations where
they would come back to interact with the living
environment.
Narrator:
For Science Today, I'm Larissa Branin.
E.
There is a Positive Side to the 'Terrible Twos'
Narrator:
This is Science Today. Most parents
have no doubt heard about, and perhaps feared, that
time in a child's life coined "the terrible twos".
Alison Gopnik, a psychology professor at the University
of California, Berkeley says as exasperating as
toddlers can be during this rebellious period, it's
a time that's crucial to their cognitive development.
Gopnik:
What we've done is a bunch of very careful experiments
to show that between the time babies are born and
the time they're about four, they're changing their
ideas about how other people work in very regular
and systematic ways.
Narrator:
This is done during everyday interactions with people.
Gopnik:
So, you can think of the terrible twos as being
a kind of experiment that comes when you're eighteen
months old and you suddenly get this new, startling
hypothesis about other people which is, "my God,
maybe sometimes they don't want the same thing that
I do! Let me check this out and test out ideas -
especially about how other people work.
Narrator:
For Science Today, I'm Larissa Branin.
