A growing number of teen girls say they use the rhythm method for birth control, and more teens also think it’s OK for an unmarried female to have a baby, according to a government survey released Wednesday.
The report may help explain why the teen pregnancy rate is no longer dropping like it was.
Overall, teenage use of birth control and teen attitudes toward pregnancy have remained about the same since a similar survey was done in 2002.
But there were some notable exceptions in the new survey by the Centers for Disease Control and Prevention. About 17 percent of sexually experienced teen girls say they had used the rhythm method — timing their sex to avoid fertile days to prevent getting pregnant. That’s up from 11 percent in 2002.
Cancer is a disease whose treatments are notoriously indiscriminate and nonspecific. Researchers have been searching for a highly targeted medical treatment that attacks cancer cells but leaves healthy tissue alone. A team of scientists at Washington University in St. Louis (WUSTL) is working on gold nanocages that, when injected, selectively accumulate in tumors. When the tumors are later bathed in laser light, the surrounding tissue is barely warmed, but the nanocages convert light to heat, killing the malignant cells…
At the annual TED conference in Long Beach, Calif., a Microsoft alumnus demonstrated how inexpensive lasers could be used to fight malaria by zapping mosquitoes mid-flight.
Former Microsoft CTO Nathan Myhrvold says his company, Intellectual Ventures, can assemble electronic parts from readily available devices — printers, digital cameras, projectors — to make ground-to-air lasers that can take out mosquitoes.
That’s a much cooler solution than just using netting.
Myhrvold demonstrated the laser at the conference by releasing hundreds of mosquitoes into a glass tank in front of an audience. The laser tracked their movements and, one by one, shot them down, their bodies piled on the bottom of the tank.
Myhrvold said the lasers can shoot between 50 and 100 mosquitoes per second, and using video playback, slowed down the demonstration for the audience to view. In the video, the mosquitoes are hit by a beam of light and disintegrate in a plume of smoke.
Myhrvold said the software detects the speed and size of the target before firing — so, for example, it would leave a butterfly unharmed but target a locust.
(How precise is it? So much so that it can determine gender, since female mosquitoes are bigger and beat their wings at lower frequencies. Only females bite humans, so the system actually leaves male mosquitoes alone.)
Curious? Here’s the 0.01-second shootdown sequence, in slow motion:
The laser is effectively a chemical-free pesticide, and could be used to protect medical clinics, homes and farms from the bugs.
At last year’s TED conference, Myhrvold’s former boss, Bill Gates, released mosquitoes into the audience to emphasize his point about the threat malaria poses to developing countries.
The tech, by the way, is simple enough: it combines the precision of laser printing with image-detecting digital camera CCDs plus software to make it happen. Myhrvold has expressed interest in Blu-ray technology as well, because blue lasers are more powerful than red ones.
Altogether, the device could cost as little as $50, depending on volume. For now, it’s merely a proof-of-concept device.
