Moon Medicine, Super Shrews, Grizzly’s Best Friend, More

Each week we’ll round up links to science stories or studies that blow our mind, tickle our funny bone, or generally strike our fancy.

Lunar Medicine
If you’re scheduling heart surgery, consider checking the lunar cycle. A study drawing on data from two Rhode Island Hospitals found that, during a waning full moon, patients were less likely to die undergoing repair of ascending aortic dissection, and they also spent less time in the hospital overall. This isn’t the first time that heart conditions have been tied to the tides, but the phenomenon isn’t clearly understood. Other factors play a role in medical calamities, such as the time of day when procedures are conducted—the risk of complications from anesthesia increase later in the day, for instance, perhaps coinciding with the drug administrator’s plummeting energy levels.*
—Popular Science

Shrew Got Back
The hammer-wielding Norse god of strength has a namesake in…a shrew.** Thor’s hero shrew—so-named for its powerful back—was recently discovered in the Democratic Republic of the Congo, according to a paper in Biology Letters. The rare mole-like mammal—only the second type of hero shrew scientifically identified—sports eight vertebrae at the base of its backbone, whereas most mammals only have about five. Meanwhile, the first hero shrew ever discovered has even more vertebrae, suggesting that Thor’s buddy “may be a transitional form in the evolutionary history of hero shrews,” writes Christine Dell’Amore. The study theorizes that hero shrews use their super backs to access food that other animals can’t get. (If only it were for throwing lightning bolts.)
—National Geographic

Understanding the Anorexic Brain
Starving ourselves is anathema to human nature. So why do people with anorexia do it? Recent research into their brain chemistry suggests that sufferers have a different neurological reaction to food. Certain brain areas seem unresponsive to taste, for instance, and “a sharp pang of hunger might register instead as a dull thud,” writes Meghan Rosen. While a healthy person’s pleasure centers light up when he has a sweet treat, people with anorexia experience no such joy—for them, a dopamine surge triggers anxiety instead, research has shown. Another study showed that people with anorexia have an active dorsolateral prefrontal cortex, which reins in impulses and could play a role in how sufferers suppress their appetite.
—Science News

Grizzly’s Best Friend
The Yellowstone grizzly bear has a friend in another apex predator—the gray wolf. A study published in the Journal of Animal Ecology suggests that grizzlies are thriving on certain berries because of the wolf, which was reintroduced to the park in 1995 after a 70-year absence. Previously, elk gobbled up the berries that the grizzlies ate for extra winter weight. Now that the wolves have controlled the elk population, berries are increasing, which is good news, considering how a prior grizzly staple—whitebark pine nuts—are declining. And wolves aren’t just lending bears a helping paw. Earlier research has shown that the wolf’s ability to control the elk population brought a resurgence of aspens, cottonwoods, and willows, which, in turn, helped park beavers.
—L.A. Times

*This post was updated on August 2, 2013 to reflect the fact that patients “underwent repair of ascending aortic dissection,” rather than “underwent aortic dissection.” Also, the original post stated that the study was done at Rhode Island Hospital. The study actually drew on data from two Maryland hospitals: Miriam Hospital and Rhode Island Hospital. Read more here.

**This post was updated on July 31, 2013 to reflect the fact that shrews are not rodents. They are mole-like mammals.