|
A.
A Revolutionary Artificial Back Disc Under Study
Narrator:
This is Science Today. Orthopedic surgeons at the
University of California, San Francisco are joining
13 other centers in a four-year study to determine
the safety and effectiveness of a European-designed
implant called the Prosdisc that may replace damaged
lower back discs. Dr. David Bradford of UCSF says
the Prosdisc shows lot of promise.
Bradford:
Over 300 to 400 cases now have been done worldwide
and over 100 cases have been done in North America
and the data looks very good - the early results.
Nonetheless, the FDA wants to see controlled studies
comparing this with standard fusion to see if truly
this result is better than what you might see with
a fusion.
Narrator:
The ball-and-socket design of Prosdisc allows normal
functioning and structure of the spine.
Bradford:
We've done this procedure already here at UCSF.
We feel that the results are most likely to show
that this would be approved as a stand-alone device.
Narrator:
For Science Today, I'm Larissa Branin.
B.
An Innovative Drilling Technique Has Potential Use
on Mars
Narrator:
This is Science Today. Innovative drilling instruments
and techniques developed to probe subglacial lakes
in Antarctica, may someday lead to similar work on
Mars. In fact, cosmic ray physicist Buford Price,
of the University of California, Berkeley says their
sterile, ultraviolet light-emitting detectors could
possibly be used to search for signs of life on Martian
polar caps.
Price: We know that there exists
water widely distributed over both the north and South
Pole on Mars. Whether it's in the form of liquid or
solid, almost certainly most of it, at least down
to many meters depth, is frozen. But that temperature
is definitely such that certain kinds of organisms
can survive.
Narrator:
These microorganisms are aptly called extremophiles.
Price:
Some
of them don't need oxygen, some don't need sunlight,
some eat hydrogen and breathe methane - they really
are weird! They are so unusual that it has encouraged
those biologists who are interested in life on other
planets.
Narrator:
For Science Today, I'm Larissa Branin.
C.
Why Farm Children Have Less Asthma
Narrator:
This is Science Today. Images of growing up on
a farm are often associated with robust health - and
now there's scientific evidence supporting this old
association. Preventive medicine specialist, Mark
Schenker, of the University of California, Davis,
says studies have shown that children who grew up
on a farm are less likely to suffer from allergies
and asthma, thanks to exposure to allergens, or antigens,
found on the farm.
Schenker:
Exposure to a number of antigens that exist on
the farm protects against subsequent development of
allergies and probably asthma.
Narrator:
Schenker says this so-called 'hygienic hypothesis'
may also explain why children in urban environments
have higher rates of allergies and asthma.
Schenker:
As we move to more hygienic environments without exposure
to a number of antigens in early life, we make ourselves
at increased risk for allergic, asthmatic reactions
as adults.
Narrator:
For Science Today, I'm Larissa Branin.
D.
Researchers Creating an Efficient, MEMS-based Fuel
Cell
Narrator:
This is Science Today. Micro-electrical-mechanical
systems, or MEMS, use chemical or other types of processes
to literally micro machine silicon into mechanical
structures. An actual systems-on-a-chip concept. Jeff
Morse, a researcher at the Lawrence Livermore National
Laboratory, is working on a MEMS-based fuel cell power
source, which he says may one day replace rechargeable
batteries.
Morse:
This is in fact a miniature fuel cell and what fuel
cells offer is they nominally will operate off of
either hydrogen fuel, or I think more recently for
small and portable applications, hydrocarbon-based
fuels - for example, methanol or butane.
Narrator:
The benefit of this technology is that it's a direct-conversion
device.
Morse:
The key thing is it's storing the energy as fuel and
so it converts that directly to electricity with a
little bit of losses due to heat and inefficiencies,
but by comparison to batteries, you might see maybe
a factor of two or three - and possibly even factors
of ten improvements in operating time.
Narrator:
For Science Today, I'm Larissa Branin.
E.
Exposure to Pesticide Interferes with Frog Sexual
Development
Narrator:
This is Science Today. A recent study has found that
frogs exposed to a common pesticide called atrazine
have problems with the development of their sexual
characteristics. Biologist Tyrone Hayes of the University
of California, Berkeley says some of the testosterone
was converted to estrogen.
Hayes:
The conversion of testosterone to estrogen results
in a drop in the masculinizing hormone, so that animals
don't develop some of their masculine features if
they're male. But in addition, they're also feminized.
The production of estrogen by the male frogs causes
development of female characters that don't normally
appear in males.
Narrator:
Although the effects of these changes on frog fertility
are not yet known, Hayes says his results could have
implications for human health.
Hayes:
The
genes that control sex and gonadal differentiation
in humans, those same genes are present in amphibians.
Some of the sequences are exactly the same. Male frogs
croak and females don't. In humans, males have deeper
voices than females for the same reasons.
Narrator:
For
Science Today, I'm Larissa Branin.
|
