Health & Science
Here comes the sun; Why teens get pregnant; New hope from stem cells; Psilocybin for depression
Here comes the sunEarth got off relatively easy last week after being hit by the biggest blast of solar radiation since 2005—but we may not be so lucky next time. Last week’s coronal mass ejection, in which a solar flare whipped an arc of magnetic particles toward Earth at 4 million mph, led some airlines to reroute flights away from the poles, where their effect was most intense, lighting up atmospheric gases into unusually extensive auroral light displays. But because the Earth wasn’t directly in the path of the X-rays and charged particles, damage was minimal. “We pretty much dodged a bullet,” NASA’s Antti Pulkkinen tells NationalGeographic.com. Trouble, however, may lie ahead. Scientists say last week’s storm was just an opening volley in a period of unusually intense solar activity that could cause trouble for communication satellites, data transmission, and long-distance power lines. The storm signaled the end of “the quietest solar period in more than 100 years,” says Boston University space-weather expert Jeffrey Hughes. The sun’s shifting magnetic fields are known to amp up their activity on an 11-year cycle, and this one is expected to peak next year. Pulkkinen says that means that more-frequent and more-intense solar storms “will no doubt be directed toward Earth.”
Why teens get pregnantA startling number of American teenage girls hold erroneous ideas about sex and pregnancy, which may explain why the U.S. has the highest teen-pregnancy rate in the developed world. Researchers from the Centers for Disease Control and Prevention surveyed nearly 5,000 teenage mothers and found that only half of them used birth control. Of those who did not, a third said they didn’t think they could become pregnant. Some thought they or their partners were sterile, while others likely believed common myths—such as that a woman can’t conceive during her first sexual experience or while menstruating, or that showering or drinking bleach after sex prevents conception. “When you ask teens, ‘Do you know what you need to know about preventing unplanned pregnancy?’ they say ‘yes,’” Bill Albert, spokesman for the National Campaign to Prevent Teen and Unplanned Pregnancy, tells the Los Angeles Times. “But there is a disconnect between what teens think they know and what they actually know.”
New hope from stem cellsEmbryonic stem cells injected into the eyes of two legally blind patients appear to have restored some of their sight—the first direct evidence yet of such therapy helping patients. That largely unexpected success is “a major milestone that will offer tremendous encouragement” to scientists working in the stem-cell field, Harvard Medical School researcher George Daley tells ScienceNow.org. Embryonic stem cells can morph into any type of cell in the body, so in theory they could be used to treat a host of serious ailments, from Alzheimer’s to paralysis, by replacing cells damaged by injury and disease. But scientists hadn’t yet determined whether injecting stem cells into people would stimulate tumors or cause other health problems. This study was an attempt to answer that question. Stem cells were transformed into retinal cells and implanted into the eyes of two women suffering from macular degeneration—a common, untreatable cause of blindness. The new retinal cells caused no harmful effects, and they improved the women’s vision. “One day, I looked down and I could see my watch,” says Sue Freeman, one of the stem-cell recipients. “That was exciting.”
Psilocybin for depression“Magic’’ mushrooms could have the capacity not only to blow users’ minds but also to heal them. British neuroscientists injected volunteers with the chemical psilocybin, the psychedelic ingredient in hallucinogenic mushrooms, while scanning their brains. Since psilocybin mushrooms “are thought of as ‘mind-expanding’ drugs,” the scientists expected to see marked increases in brain activity, Imperial College London professor David Nutt tells Nature News. But to their surprise, activity decreased—especially in the parts of the brain that ground us in reality and govern our sense of self. Those regions—the medial prefrontal cortex and the posterior cingulate cortex—tend to be hyperactive in people with depression. The finding suggests that psilocybin’s ability to give recreational users dream-like, out-of-body experiences could also help depressed patients break free of the “particularly restrictive state of mind” that forces them into loops of negative thinking, says study co-author Robin Carhart-Harris. The effects could also be long-lasting; previous research has shown that a single high dose of psilocybin can improve the mood of recipients for more than a year.