Scintilla

Proceedings of the National Academy of Sciences, November 3
Two studies in PNAS focused on the wildlife and landscape of East Africa. In the first, researchers looked back in history to Kenya’s infamous man-eating lions, which reportedly devoured 135 railroad laborers in 1898. The two lions were eventually shot, killed, stuffed, and shipped to Chicago’s Field Museum for display–which allowed researchers to analyze samples of the lions’ bones and fur. By comparing the isotopes present in the man-eating lions to those found in other lions, humans, wildebeest, and buffalo, the researchers could precisely determine the lions’ diet. The results brought the body count down considerably: The scientists estimate that one of the lions ate 24 people, while the other gobbled up 11. The second study looked ahead, and predicted that Mount Kilimanjaro, the highest peak in Africa, could lose its distinctive ice cap by 2022 due to global warming.

Journal of the American Medical Association, November 4
A new study of hospitalizations in California due to swine flu has highlighted a neglected risk factor: obesity. In the study group of patients whose weight was known, researchers found that 25 percent of the people were morbidly obese, although less than 5 percent of the U.S. population falls into that category. Researchers also found that 58 percent of these hospitalized patients were obese–in the population as a whole, about 34 percent of people are obese. The increased risks come partially from health problems associated with obesity, like heart disease, lung ailments, and diabetes. But physiological factors may also be to blame: The lungs of obese patients are squeezed by the abdomen pressing upward on the diaphragm.

Nature, November 5
A new astronomy study has solved a mystery that began brewing in 1680, when Britain’s first Astronomer Royal spotted a supernova in the constellation Cassiopeia. Supernova typically collapse into a super-dense object like a black hole or a neutron star, but for decades astronomers have looked for such an object at the center of the supernova remnant, to no avail. Now, a new examination suggests that there is indeed a baby neutron star there, but it escaped detection because it’s swaddled in an unusual atmosphere of carbon gas. Further studies of the 330-year-old star will give researchers insight into how such stars mature. Another study brings us from the macro to the micro, with an investigation into the evolution of bacteria. Researchers forced bacteria to evolve in constantly changing conditions, so that natural selection couldn’t produce microbes that were ideally suited to a single environment. Instead, researchers proved that the bacteria hedged their bets by evolving into a strain that could form several different shapes from the same genetic material. The will to survive: It’s an amazing thing.

Science, November 6
The biggest study from Science reveals a very promising treatment for the fatal, inherited brain disease that was made famous by the movie Lorenzo’s Oil. Adrenoleukodystrophy (ALD) is caused by a faulty gene that leads to the destruction of nerve fibers’ insulating sheaths; without that insulation, electrical signals can’t be transmitted. The progressive disease is usually diagnosed in young boys, who typically die before adulthood. In the new experimental treatment, researchers used a deactivated HIV virus to ferry a working gene into the stem cells found in the patients’ bone marrows. Since the virus integrates itself permanently into the DNA of the cells it enters, researchers hope the patients will keep the working genes for the rest of their lives. More than two years after the treatment, the patients show no sign of further deterioration, and are able to live relatively normal lives. While the boys will continue to be monitored for side effects, the study brings fresh hope not just to ALD sufferers, but also to those who believe that gene therapy holds tremendous medical promise, despite earlier setbacks.

Current Biology, November 3
When Charles Darwin and the crew of the HMS Beagle arrived at the remote Falkland Islands, 300 miles from the tip of Argentina, they wondered how the islands came to be populated with the strange Falkland wolves. The small wolves were the only mammals present on the islands, and one theory of their origin posited that they were descended from dogs brought over by Native Americans. Now a new genetic study of four museum specimens (sadly, the wolves have since gone extinct) has proven that theory wrong. The study showed that the wolves shared a common ancestor at least 70,000 years ago, which suggests that the wolves arrived on the islands long before the first humans made it to the new world.

The glaciers that shine at the top of Mount Kilimanjaro, the highest peak in Africa, could vanish entirely within 15 years, according to a somber new report. Says glaciologist Lonnie Thompson: “Of the ice cover present in 1912 … 85% has disappeared and 26% of that present in 2000 is now gone” [USA Today]. The mountaintop glaciers are both shrinking around the edges and growing thinner, Thompson’s team found. If the current rate of ice loss continues, the mountain could be ice free as early as 2022.

Thompson says his team has fresh evidence that global warming is to blame. As similar changes are occurring on other mountains in Africa, South America, and in the Himalayas, Thompson says that global climate change, not local weather effects, must be responsible for the receding ice. “The fact that so many glaciers throughout the tropics and subtropics are showing similar responses suggests an underlying common cause,” Thompson said [AP].

For the study, published in the Proceedings of the National Academy of Sciences, the researchers used maps, aerial photographs, and satellite images to track the ice’s retreat over the last century, and also looked at data from instruments implanted in the glaciers in 2000. Some previous researchers have argued that Kilimanjaro’s glaciers are disappearing because of what they viewed as local factors, namely less snowfall and more sublimation, which turns ice directly into water vapor. But Thompson found that higher temperatures are melting the ice, and he also argues that the drier and less cloudy conditions leading to sublimation on Tanzania’s Kilimanjaro are part of a suite of changes driven by global warming. “You change the temperature profile of this planet, you are going to change precipitation and cloudiness and humidity and temperature,” he said. “Those are all part of climate change. And so to say that that Kilimanjaro is not responding to global climate change is untrue” [National Geographic News].

If the glaciers disappear entirely, it will make an anachronism of a great piece of literature. The “snows of Kilimanjaro” were made famous in the Ernest Hemingway short story of that name in 1938, in which the main character notices “as wide as all the world, great, high and unbelievably white in the sun, was the square top of Kilimanjaro” [USA Today].

Related Content:
80beats: 2 Trillion Tons of Polar Ice Lost in 5 Years, and Melting Is Accelerating
80beats: From Yellowstone’s Hills to Walden Pond’s Woods, Evidence of Global Warming
80beats: Global Warming Threatens Tropical Species, Too
80beats: Plants “Climb” Mountains to Escape Global Warming

Image: Lonnie G. Thompson / Ohio State University