A.
Laser Technology Produces Major Savings for Aircraft
Parts
Narrator:
This is Science Today. Advances in laser
peening technology will enable engineers to design
commercial and military aircraft parts that are
safer, lighter, built to last and will save hundreds
of millions of dollars. Lloyd Hackel of the Lawrence
Livermore National Laboratory, says a commercial
firm is now using the laser peening technology they
developed at the Lab.
Hackel:
We developed a laser that runs about twenty-five
times faster than anything else like it in the world.
This laser puts out a Gigawatt of peak power – that’s
the output power of a huge electric power plant
equivalent, but it only does it for about twenty
nanoseconds.
Narrator:
That’s enough time to significantly increase the
lifetime of metal fan blades used on large jet engines.
Hackel:
The blades were quite expensive, so the small cost
of laser peening them was an enormous payback in
the extended lifetime and the reduced maintenance
on the blades. So, instead of having to tear down
the engine and inspect it for safety every several
months, you now go several years because you know
the cracks won’t grow.
Narrator:
For Science Today, I’m Larissa Branin.
B.
A Genetic Mutation Found to Cause Trouble for Some
Congenital Heart Disease Patients
Narrator:
This is Science Today. Each year, thousands
of children undergo corrective surgery for congenital
heart malformations, such as holes in the heart,
to improve the immediate function of the heart.
But Dr. Kenneth Chien of the University of California,
San Diego School of Medicine, has discovered there’s
an underlying, genetic mutation that continues to
degrade the heart and in some cases, leads to sudden
death later in life.
Chien:
This gene plays an important role in the earliest
stages of heart formation, but what we were able
to uncover is a role for this gene in the later
stages of heart formation during the formation of
the electrical wiring of the heart of the conduction
system in the pacemaking cells. So while in this
case, the defect would be invisible to the naked
eye, at a molecular level it’s a severe defect.
Narrator:
Chien says this is a recent discovery because the
genetic tools and markers for identifying these
specialized, cardiac pacemaker-like cells have only
recently been developed.
Chien:
So this actually represents, I think, one of the
frontier areas in cardiac arrhythmias now.
Narrator:
For Science Today, I’m Larissa Branin.
C.
New Insight into What May Cause Drug Addiction
Narrator:
This is Science Today. What makes an addict an addict?
Howard Fields of the University of California, San
Francisco is working to find out by studying molecules
in the brain called opioids, which are responsible
for feelings of pleasure. According to Fields, the
answer lies in the interaction between two opposing
parts of the brain’s pleasure system: the kappa
and the mu opioid systems.
Fields:
Endogenous opioids act at several different receptors.
Morphine and heroine, they act at the mu receptor.
But there’s another receptor called the kappa opioid
receptor, and it has effects that are opposite to
the mu receptor.
Narrator: Dynorphin, one of the
brains natural opioids, acts at the kappa receptors
where it is responsible for counteracting the pleasurable
effects caused by addictive drugs at the mu receptors.
One theory is addicts don’t have the same dynorphin
response as non-addicts.
Fields: In most people, maybe there’s
more dynorphin than endorphin, so there’s more of
an action at the kappa receptor than there is at
the mu receptor.
Narrator:
For Science Today, I’m Larissa Branin.
D.
Stem Cells Discovered in the Human Brain
Narrator:
This is Science Today. Until recently the
number of cells in the human brain was thought to
be finite, but researchers at the University of
California, San Francisco have uncovered convincing
evidence that the adult human brain can make new
cells. According to Nader Sanai, a resident in neurological
surgery, these neural stem cells were initially
missed because they looked a lot like a common cell
type called an astrocyte.
Sanai:
In the past when people saw these cells dividing,
they assumed that these cells were just the run
of the mill astrocytes, which were dividing in response
to a cell injury for example. What they didn’t really
consider seriously was the possibility they were
dividing because they were producing various progeny.
Narrator:
But it turns out these cells do have the potential
to become neurons and that opens up a lot of therapeutic
doors – but the key lies in understanding the cues
that control their growth and division.
Sanai:
Right now the most important concept in
the field is probably to understand the basic biology
underlying these cells so that we can have a proper
approach and method to actually controlling them.
Narrator:
For Science Today I’m Larissa Branin
E.
Using Smart Dust Motes for Archeological Preservation
Narrator:
This is Science Today. Smart dust motes
are tiny sensors with wireless radio transceivers
that allow one to sense structures intelligently.
Steve Glaser, a professor of civil engineering at
the University of California, Berkeley says these
devices are being used to monitor buildings, bridges
and other structures for structural soundness. But
Glaser says, they can also use smart mote technology
for archeological preservation.
Glaser:
For instance, we’ll probably go and instrument
the Meseba site in Israel – it’s a World Heritage
Site. So the people running the facility don’t want
wires. So we’ll be monitoring some large pieces
of the mountain that could fall off on people and
also, the seismic behavior because the Dead Sea
is below sea level because it’s a seismically active
area.
Narrator:
Smart dust motes are also less expensive.
Glaser:
The traditional devices cost tens to hundreds
of thousands of dollars a piece. We’ll make them
for about five thousand dollars a piece.
Narrator:
For Science Today, I’m Larissa Branin.
