A. A Successful Procedure for Patients with Irregular Heartbeats
Narrator: This is Science Today. Arrhythmias – or irregular heartbeats – are the most common cause of sudden cardiac death in this country in both men and women. Just a decade ago, the only treatments were drugs, pacemakers or open-heart surgery, but cardiologist Jeffrey Olgin of the University of California, San Francisco Medical Center, says that's changed.
Olgin: Today, a new procedure pioneered at the UCSF Medical Center, zaps away abnormal heart tissue to cure patients with arrhythmias. The advantage of this procedure, called catheter ablation, is that it does not require incisions like open heart surgery.
Narrator: Olgin says this means patients can usually leave the hospital the same day, avoiding a long recovery or a lifetime of drug treatment. A recent UC San Francisco study of nearly 400 catheter ablation patients wfound that one month after the procedure, 98 percent required no medication and 95 percent reported considerable improvement in their overall health.
Olgin: At UCSF Heart and Vascular Center, patients have access to the latest innovations and treatments.
Narrator: For Science Today, I'm Larissa Branin.
B.
How Early Humans Adapted to Colder Climates
Narrator: This is Science Today. A new study finds mutations in the mitochondrial DNA of human cells may have helped migrating, early humans from Africa adapt to colder, northerly climates. Douglas Wallace, co-leader of the University of California, Irvine study, says mitochondria are the power plants of cells, generating heat to maintain body temperature and synthesizing ATP, a chemical form of energy.
Wallace: These mitochondria are actually ancient symbiotic bacteria that entered our cells about 3 billion years ago and as a result, they have their own genome, their own DNA. Therefore, we've been able to reconstruct the origin and migration by actually examining the sequence variation of the mitochondrial DNA.
Narrator: Researchers discovered that a key change in the mitochondrial DNA of early humans may have resulted in successful adaptation to the cold.
Wallace: By changing this energy balance of their mitochondrial power plants from primarily work ATP production, to a high percentage of heat production to survive the cold winters.
Narrator: For Science Today, I'm Larissa Branin.
C.
Fish Collections Around the World Benefit from Technology
Narrator: This is Science Today. Scientists studying the fish collection at the University of California, San Diego's Scripps Institution of Oceanography have a saying: so many fish, so little time. H.J. Walker, a senior museum scientist, says technology has helped scientists connect with other fish collections around the world.
Walker: It's like book libraries that connect. We actually can search each other's collections now over the Internet, which is fantastic to find out which specimens we have as far as various species. Technology has really helped us as far as getting information out.
Narrator: Recently, Walker and his colleagues have been studying the megamouth shark – a rare, gentle giant that feeds on plankton and, as the name implies, has a huge mouth. The first megamouth shark ever discovered was found near Hawaii in the mid-1970s.
Walker: It's so incredible so many things in the ocean that we still haven't figured out. We're very much into finding out when we have a new species, how these relate to species that have already been described. And how these related species work up the hierarchy, say for example, what families constitute an order and ultimately, the class of vertebrates.
Narrator: For Science Today, I'm Larissa Branin.
D.
A Small Ocean Glider vs. the Gulf Stream
Narrator: This is Science Today. When researchers at the Scripps Institution of Oceanography at the University of California, San Diego, first launched an autonomous underwater vehicle called Spray, the plan initially failed. Equipment malfunction stopped the mission temporarily and then nature took its course. Traveling the Gulf Stream, the 112-pound glider was up against one of the world's strongest currents. Scripps Oceanographer Russ Davis explains.
Davis: The Gulf Stream carried it back exactly in the opposite direction and eventually we wiggled around and got there after almost two months of work.
Narrator: Traveling half-a mile-an hour Spray did make it from Massachusetts to Bermuda. Now Davis wants the six-foot-long glider to make a roundtrip voyage.
Davis : It remains to be seen whether we'll be able to do two of those roundtrips from the same vehicle, it depends on how good we get it, doing it quickly, ‘cause it only has so much gas, so to speak.
Narrator: For Science Today, I'm Larissa Branin.
E.
Testing the Accuracy of a Mathematical Model that Simulates Epilepsy
Narrator: This is Science Today. A University of California, Berkeley researcher has applied a mathematical model to simulate what happens in the brain during an epileptic seizure. Mechanical engineer, Andrew Szeri and his colleagues at the University of California, San Francisco tested the model against an actual patient.
Szeri: We looked at 6 seizures from this single patient, and we focused on two electrodes where it was obvious there was a kind of wavy disturbance that was passing.
Narrator: Sixty-four electrodes were surgically implanted in the patient's brain. This allowed researchers to plot brain activity during a seizure. By testing out their mathematical model using a computer, scientists know more about how and why seizures occur. And this could lead to better treatment methods.
Szeri: For example people are working on interventions like focal cooling a part of the brain. It's been observed that if you cool rapidly a part of the brain that is undergoing a seizure it can dampen down the seizure essentially.
Narrator: For Science Today, I'm Larissa Branin.
