A. Light Adjustable Lens Shows Promise for Cataract Patients
Narrator: This is Science Today. Many cataract patients have to wear prescription glasses after surgery because there's no way to predict how the eye will heal. But an implantable lens that can be perfectly adjusted after surgery using ultraviolet light, may someday offer an alternative.
Schwartz: The light adjustable lens is similar to a conventional implant that are placed in the eye – the surgery's the same, the recovery's the same, but the difference is that instead of getting a prescription for glasses, we can shine a special light onto this lens and change its power after the lens is in place and after the eye is healed.
Narrator: Dr. Daniel Schwartz of the University of California , San Francisco , teamed up with researchers from the California Institute of Technology to invent this new way to fine-tune a patient's vision.
Schwartz: With conventional cataract surgery, the patient has a cloudy lens, or cataract, and the cataract is removed by the surgeon and then replaced with a clear lens. Those lenses are nonadjustable, which means that the lens you have put in your eyes is a lens you're going to keep for the rest of your life.
Narrator: Schwartz hopes this procedure will be available in the U.S. by late 2009. For Science Today, I'm Larissa Branin.
B.
Structural Engineers Test Revolutionary New Theory
Narrator: This is Science Today. Structural engineers at the University of California, San Diego's Jacobs School of Engineering have used their 25 foot by 40 foot shake table – the largest in the country and the only outdoor one in the world – to test a revolutionary new theory that mid-rise structures can be built to survive powerful earthquakes with less steel reinforcements than currently required by California building codes. Jose Restrepo, a professor of structural engineering and co-leader of the project, explains.
Restrepo: We ended up placing about one half of the reinforcements required by the code and that allows us to minimize the stresses on the building, on the foundations, we can tell the building to sway, flex, bend back and forth, opening up cracks like breathing and dissipating energy and allowing it to bend and not to break.
Narrator: The engineers simulated the ground motions from the 1994 Northridge , California earthquake and discovered that their theory held up as well as the seven-story structure did. For Science Today, I'm Larissa Branin.
C.
Astronomers Discover a Distant, Icy Earth-like Planet
Narrator: This is Science Today. Earlier this year, an international team of astrophysicists discovered a distant, icy planet five times the size of Earth. The smallest extrasolar planet revealed outside of our solar system was found using a technique called microlensing that is based on an idea Albert Einstein came up with 70 years ago. Astronomer Ken Cook of the Lawrence Livermore National Laboratory, who was part of the group that made the discovery, says this happens when a foreground star passes very close to the line of sight of a more distant star. This creates a ring-like image.
Cook: Now, this ring is so small on the sky that we can not tell it's a ring – all that we can tell is that suddenly the star is brighter. And when planets get near the ring, it perturbs the light coming, so it causes a little bump in the light curve that we see. As soon as this star moves off the line of sight, this star goes back to being dimmer and its normal self.
Narrator: The new Earth-like planet, made of rock and ice, orbits a parent star every ten years at three times the distance from Earth to the sun. For Science Today, I'm Larissa Branin.
D.
A Novel Approach Used to Study Memory Formation
Narrator: This is Science Today. There are many different tools researchers can use to study a brain neuron to get an idea of what's going on within the system. At the University of California , San Francisco , Pamela England, an assistant professor of pharmaceutical chemistry, used a novel combination of pharmacology and the use of light.
England : These receptors are operating on the millisecond timescale. Synaptic transmission or the communication between neurons in your brain is incredibly fast and so what you want is a technique that operates on that same timescale.
Narrator: England used brief pulses of ultraviolet light to inactivate receptors on certain parts of the cell to see how the brain refreshes the supply of molecules it needs to make new memories.
England : Our study involved looking at AMPA receptors on hippocampal neurons because the hippocampus is a memory center in the brain. And the next step is going to involve using molecules that are selective for one type or the other to figure out which type of AMPA receptor should we care about in terms of memory.
Narrator: For Science Today, I'm Larissa Branin.
E.
Understanding How Climate Change Will Affect Plants and Animals
Narrator: This is Science Today. Scientists have been pointing to climate change as a future cause for droughts, floods, and other natural disasters. Now, biologist Kaustuv Roy of the University of California , San Diego says that climate change can also affect the ecology of certain areas.
Roy : Plants and animals shift around on the landscape so you may have built a nature reserve today and you know exactly what you're trying to preserve because they live there, but if the climate changes substantially, some of those plants and animals may move somewhere else.
Narrator: While the study of climate change is relatively new, Roy says that it could be one of the most important problems facing the planet.
Roy : It really doesn't matter which side of the conservation debate you're in. We all need to figure out what the consequences of the climate warming are. If you can't figure out the consequences, you can't even have a good conservation plan or you can't have a good management plan. And, given the trajectory of climate over the next few centuries, the magnitude of that problem is so big that we better pay attention to it.
Narrator: For Science Today, I'm Larissa Branin.
