UNC-TV Science Week In Review: November 14, 2013
Taking the Scenic Route
Scientists often find themselves stuck on a particular problem. One of the founding fathers of astrophysics, Johannes Kepler, was convinced beyond convinced that planetary orbits, or the paths the planets travel on, were based on the relationship of shapes called the five perfect solids. He spent years trying to make the solids fit into one another to show why the planets were where they were.
It took Isaac Newton to think about orbits another way, with gravity, to explain why the planets were where they are. Not to cheapen Newton’s ideas, but with a little more insight and information, Kepler probably could have figured this out, but he kept thinking about the problem the same way, convinced the perfect solids were they key.
Scientists often have to re-evaluate the ideas of their field to make a new breakthrough. By choosing a new path, North Carolina scientists were able to advance the way we think about their fields.
New Guidelines for Cholesterol
For years, doctors have been told to prescribe cholesterol-lowering drugs, called statins, to patients with a high level of LDL or “bad cholesterol.” Once patients reached a specific LDL level, doctors would prescribe statins like Lipitor and Zocor.
But now, the American Heart Association and the American College of Cardiology have published a new set of guidelines that will increase the number of people on statins. UNC cardiologist Dr. Sydney Smith helped write those recommendations.
Instead of prescribing statins based solely on LDL levels, doctors are now urged to give statins to patients with past history of heart disease and stroke, high risk for heart disease, and people between the ages of 45 and 70 with diabetes as well. The new recommendations are expected to double the number of Americans taking statins (currently about 15 million people).
Harvesting Microwaves for Energy
When you hear the word 'microwave,' you probably think of the kitchen appliance that makes your Hot Pockets (okay maybe that’s just me). But microwaves are a kind of electromagnetic wave, just like light, X-rays, radio waves and ultraviolet rays. Microwaves fall in the frequency range of satellite signals and wireless internet.
So some scientists from Duke, led by Steven Cummer, got the idea that if a solar panel can harvest visible light and UV rays, why can’t they make a device to harvest microwaves?
Their device is made of metamaterials (a series of electrical conductors made of copper and fiberglass) and can put out 7.3 volts with 37% efficiency. A cell phone charger requires about 5 volts, so the group hopes to use their device for a portable charger. Their design appeared in the journal Applied Physics Letters.
An Arms Race Between Bats and Moths
In Arizona, bats like to feed on the local moths. The moths, as you may imagine, are not particularly pleased with this arrangement. One particular moth, the Arizona Tiger Moth, has adapted traits to fight back against the bats.
First, you may know that bats see by echo location, similar to SONAR, so the Tiger Moths can make a clicking sound by vibrating their wings. This serves the double purpose of alerting the other moths and throwing off the bats.
The moths also produce a toxin that they store in their bodies. What’s interesting about this strategy is that it doesn’t save the moth that uses it. When a bat bites down on a moth, the moth still gets eaten. The toxin, however, makes the experience so unpleasant for the bat, that it won’t try eating other moths anytime soon.
Professor Bill Conner from Wake Forest University studied the Arizona Tiger Moths and the bats in his lab for several years before travelling to Arizona to study the behavior of these animals in their natural habitat.
- Daniel Lane
Daniel Lane covers science, medicine and the environment as a reporter/writer. He is currently pursuing a master's degree in medical and science journalism at UNC - Chapel Hill.