Health & Science
Dolphins have conversations
Dolphins have an elaborate spoken language and engage in conversations, Russian researchers have concluded. Marine biologists have recorded an exchange between Yasha and Yana, two Black Sea bottlenose dolphins that took turns producing a series of pulses, which the researchers identified as individual “words” strung together to form sentences. It’s well known that dolphins use pulses, clicks, and whistles to communicate, but the recordings reveal that they also alter the volume and pitch of the sounds they make, enabling them to convey messages and seemingly form sentences. The dolphins appeared to listen to each other without interrupting before responding— behavior reminiscent of a chat between well- mannered friends. While the researchers were unable to decipher what the dolphins were saying, their recordings suggest the marine mammals, which have larger brains than we do, communicate in a highly developed language. Researcher Vyacheslav Ryabov tells CNN.com that humans should create a device that could decode dolphin language and enable us to communicate. “We must take the first step to establish relationships with the first intelligent inhabitants of the planet,” Ryabov said.
Trees defend against hungry deer
Immobile and unintelligent, trees may seem utterly defenseless against deer and other animals that snap their branches and devour their leaves. But don’t be fooled— they know how to fight back. Researchers in Germany found that wild maple and beech trees have evolved complex survival strategies to protect themselves, reports The Washington Post. For example, when their boughs break—say, because of disease or gnawing insects—the trees release chemicals, called jasmonates, that help them recover and also serve as a kind of alarm: If one tree sets off these “wound hormones,” their neighbors do the same. The German team notes that maples and beeches can also recognize specific threats and mount tailored defenses against them. After simulating grazing roe deer by snipping branches and drizzling deer saliva on some leaves, the researchers discovered the trees produce bitter-tasting tannins to make their leaves less appetizing to foragers, and release the hormone salicylic acid, which promotes new growth. “On the other hand, if a leaf or a bud snaps off without a roe deer being involved,” says study author Bettina Ohse, “the tree stimulates neither its production of the salicylic acid signal hormone nor the tannic substances.”
Big Sugar conspired to conceal health risks
For decades the sugar industry paid off researchers to downplay the health effects of sweets and pin the blame for increased heart disease risk on saturated fat and cholesterol, a new study reveals. Combing over documents that date back half a century, a University of California, San Francisco researcher discovered that a trade group called the Sugar Research Foundation commissioned a 1967 Harvard review to discredit emerging claims about the harmful effects of sugar. Industry executives dictated what research would be included in the review and then controlled its findings, which were published in The New England Journal of Medicine, reports The New York Times. Ultimately, the review criticized studies linking sugar and heart disease and emphasized the harmful effects of unhealthy fats. In return, the Harvard researchers were paid the modern equivalent of about $50,000—a conflict of interest that was never disclosed publicly. For the next 50 years, millions of Americans opted for low-fat, sugary foods now associated with obesity and heart disease. “They were able to derail the discussion about sugar for decades,” says study author Stanton Glantz. “By today’s standards, they behaved very badly.”
Health scare of the week ‘Five-second rule’ debunked
Kids—and more than a few adults— sometimes invoke the five-second rule: After dropping food on the floor, they’ll pick up and eat the errant morsel as long as it has been retrieved within five seconds, assuming that’s hardly enough time for bacteria to contaminate it. But a Rutgers University study found this arbitrary edict is more like a myth. Researchers dropped foods of different textures, such as watermelon, bread, and gummy candy, on a variety of surfaces— including tile, wood, and carpet—that had been contaminated with salmonella-like bacteria, leaving them for various lengths of time. Longer exposure to the dirty surfaces and moisture exacerbated the spread of germs, but generally results showed that contamination could occur in less than one second. “The five-second rule is a significant oversimplification of what actually happens when bacteria transfer from a surface to food,” researcher Donald Schaffner tells ScienceDaily.com. “Bacteria can contaminate instantaneously.