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A.
Solving the Solar Neutrino Problem
Narrator:
This is Science Today. The Solar Neutrino Problem,
a physics puzzle that has stymied scientists for
decades, has been solved. Physicist Kevin Lesko
of the Lawrence Berkeley National Laboratory helped
figure it out. He says the problem had to do with
measuring these subatomic particles called neutrinos.
Lesko:
When we've measured neutrinos on Earth for the previous
forty years we've always detected fewer neutrinos
coming from the sun than should be there based on
our knowledge of how the sun works and this has been
called the Solar Neutrino Problem.
Narrator:
The difficulty was that neutrinos come in three
types, and previous tests could only detect the
electron-type neutrinos. The latest experiment found
all the neutrinos and solved the problem.
Lesko:
About one-third of the neutrinos coming from the
sun are electron type, and two-thirds are muon and
tau. And muon and tau type neutrinos would not have
been made in the sun by the nuclear physics that
goes on in the center so two-thirds of the neutrinos
have transformed or have oscillated from electron
type into muon or tau type in the process of coming
to the earth.
Narrator:
For Science Today, I'm Larissa Branin.
B.
A New Drug Halts the Progress of Early Stage Juvenile
Diabetes
Narrator:
This is Science Today. In Type 1 or juvenile diabetes,
the immune system turns on the body it is supposed
to protect and destroys the cells that produce insulin.
Juvenile diabetes affects one million people nationwide,
and once it's taken hold there's not much doctors
can do besides regulate insulin levels. But Jeffrey
Bluestone of the University of California, San Francisco,
has developed a new drug that in clinical trials made
a dramatic impact on patients who are still in the
early stages of the disease.
Bluestone:
One can take individuals who are already experiencing
a lot of destruction of their insulin producing cells
and block that or prevent further destruction by just
halting the immune system from doing it.
Narrator:
Bluestone says this potential ability
to prevent the disease from progressing is significant.
Bluestone:
The
longer you can continue to produce any of your own
insulin, even it's only a small percent, the less
likely you are to get the complications of the disease
later on in life.
Narrator:
For Science Today, I'm Larissa Branin.
C.
Molecular Data Reveals Possible New Insight into Bats
Narrator:
This is Science Today. With the help of molecular
and fossil data, researchers have been piecing together
interesting and different stories about the history
of mammal evolution. For example, Mark Springer, a
professor of biology at the University of California,
Riverside, says they've made a surprising discovery
about bats.
Springer:
With bats, you've got two major groups. Traditionally,
the mega bats do not have these complex echolocation
systems. The other group that does have the complex
echolocation systems is the microbats. The traditional
view is that the mega bats are each other's closest
relatives and all of the micro bats are each other's
closest relatives.
Narrator:
But Springer says, the molecular data suggests some
of the microbats - including horseshoe and false vampire
bats - are actually more closely related to the megabats
than to the microbats.
Springer:
If that is correct, then one of the implications is
that the evolutionary history of these complex echolocation
systems, based on pulses that are emitted by the larynx,
is more detailed than we previously believed.
Narrator:
For Science Today, I'm Larissa Branin.
D.
Thinking About Human Lifespan Differently
Narrator:
This is Science Today. There have been ongoing debates
about human lifespan - one camp believing there's
a fixed lifespan, another considering it as basically
open-ended. At the University of California, Davis,
James Carey, a biologist and demographer, says the
way the argument is currently framed, if you don't
believe there's a fixed life span, then it's as if
you're advocating immortality.
Carey:
So a more appropriate way to frame this argument,
in my view, is "Is lifespan determinate?"
Or is it indeterminate in the same way that there
are some birds that lay one egg, whereas chickens
can lay any number of eggs - indeterminate. And likewise,
lifespan is not determinate, it's open-ended, it's
indeterminate.
Narrator:
Carey developed
a new longevity theory in which longer life spans
allow people to create stronger social bonds and to
make the medical discoveries that eventually prolong
life.
Carey:
I
have to believe that understanding basic aspects of
human aging and how to control this will be discovered
down the road.
Narrator:
For Science Today, I'm Larissa Branin.
E.
Increased Awareness of Bacteria that Cause Food Poisoning
Narrator:This
is Science Today. Bacteria that cause food poisoning,
including salmonella and E.coli, have been around
a very long time. But over the years, the public has
become more knowledgeable and concerned about these
organisms. Leland Rickman, who is medical director
of the Epidemiology Unit at the University of California,
San Diego Medical Center, says that's partly due to
an increase in press coverage.
Rickman:
It's not that they're new bacteria with new properties,
but the public has become more interested.
Narrator:
In fairly recent years, researchers have also
benefited from technological advances in the field.
Rickman:
In
food poisoning cases, we're able to do what we call
molecular fingerprinting, where we can actually trace
or relate different bacteria in different parts of
the country or world to one common source. So of course
it makes for very interesting press, very interesting
reading and an exciting life for all of us people
involved in infectious diseases to be able to do this.
Narrator:
For
Science Today, I'm Larissa Branin.
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