Health & Science

Hungry pythons devouring the Everglades

Tens of thousands of invasive Burmese pythons are turning the Florida Everglades into a giant buffet, decimating entire populations of native mammals, a new survey finds. “The numbers, even to us, were astonishing,” Michael Dorcas, a biologist at Davidson College, tells the Naples, Fla., Daily News. Researchers found that since the Asian snakes were introduced to the Everglades a decade ago, rabbits and foxes have completely disappeared in some areas. Raccoons and possums have declined by 99 percent, and reductions in the number of bobcats and deer have been almost as severe. Experts fear that the pythons, which can be up to 22 feet long, are also attacking highly endangered animals—like Florida panthers, wood storks, and Key Largo wood rats—whose numbers are more difficult to monitor. The python invasion probably began with a few pet owners releasing their snakes into southern Florida’s wetlands, where they met no natural predators. The giant snakes now number in the tens of thousands, and are “notoriously hard to find and very secretive,” Dorcas says. In January, the U.S. banned their import. But the damage to the Everglades’ delicate ecosystem could already be impossible to reverse, Dorcas says. “It’s an ecological mess.”

Tracking Alzheimer’s course

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In a discovery that opens new prospects for treating Alzheimer’s, scientists have learned that the disease spreads through the brain like an infection. But instead of a virus or bacteria, what advances through the brain’s neural pathways is an abnormal form of protein called tau, which forms tangled clumps that strangle brain cells. Two separate teams of researchers charted that process by genetically engineering mice to produce human tau protein—a known marker of the disease—in a part of the brain called the entorhinal cortex. Because the human tau didn’t naturally appear elsewhere in the mouse brains, the researchers were able to trace its diffusion through the neural network over the course of 22 months. Abnormal tau and beta-amyloid, another protein linked to Alzheimer’s, generally appear first in the entorhinal cortex, but it’s only when they turn up elsewhere that symptoms of dementia occur. So if scientists can find a way to stop the tau from spreading, Columbia University pathologist Karen Duff told Bloomberg.com, “there may be an intervention point that might prevent dementia.”

A taste of alien space

A NASA satellite has encountered matter from outside our solar system—and found that it has a strikingly different makeup than matter within it. The Interstellar Boundary Explorer, which orbits 200,000 miles above Earth, captured a sample of oxygen, helium, hydrogen, and neon—elements often found floating in space. In the “alien’’ sample, however, there were far fewer oxygen atoms in the mix, suggesting that oxygen is less common in interstellar space than in our solar system. But exactly what that smaller presence of oxygen means is a “big puzzle,” Southwest Research Institute space scientist David McComas tells the Associated Press. Atoms floating in the interstellar void “are the building blocks of stars, planets, and people,’’ he says. So was our sun born in a more oxygen-rich part of the universe, making life more likely to arise here? Or is some oxygen from other regions trapped in dust and ice, and thus less likely to show up as floating particles in space? Only further research can answer these questions.

A mind-reading machine

Scientists can now tell what words you’re hearing by monitoring your brain—an advance that could lead to mind-reading technology. Researchers at the University of California, Berkeley, played recordings of actual and made-up words—like “jazz,” “peace,” “fook,” and “nim”—to epileptic patients who had electrodes implanted on the surfaces of their brains. The unique frequencies and syllables of each word fired up different patterns of neurons in the subjects’ superior temporal gyrus, a key auditory region. On the basis of those patterns alone, researchers could literally read patients’ minds, deciphering what words they were hearing with 90 percent accuracy. The finding is an “exciting” step toward understanding “the basic science of how the brain decodes what we hear” and translates it into meaning, study author Robert Knight tells the London Guardian. And since the brain appears to process internal and external dialogue in much the same way, the finding raises the possibility that similar devices could reveal our thoughts. “That might sound spooky,” Knight says, but it “could really help patients” paralyzed by injury or illness to communicate, by simply thinking about what they want to say.