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Some corals adapt to warmer waters

Warming ocean waters have already devastated many coral reefs. But new research involving a species of coral that is resistant to higher temperatures suggests that others may be able to adapt, too.

When water gets too warm, most species of coral turn white, a process known as bleaching, It often leads to death. But one species of coral, Acropora hyacinthus, is thriving off the Samoan Islands in lagoons that reach temperatures up to 95 degrees Fahrenheit. To determine what made the species so heat-resistant, and to see if others could learn to adapt, a team led by Dr. Stephen R. Palumbi, a marine biologist at Stanford, devised what he called a “coral stress test.”

The researchers placed several species of coral, including the heat-resistant one, into coolers that periodically hit high temperatures then cooled down again.

“We found that all the colonies we tested could acquire the ability to withstand higher temperatures,” though the species already accustomed to warm water performed best, Palumbi said. The scientists reported their findings in the journal Science.

Though A. hyacinthus owes some of its hardiness to genetics, Palumbi said, the test shows that it also gained resistance through conditioning as temperatures rose and fell, like an athlete running one mile farther every day. If other species can do so as well, then perhaps the short-term prognosis for coral is not so dire.

Lab rats stressed by male scientists

Male researchers might want to bring a female chaperone when working with rodents. A new study suggests rats and mice experience more stress in the presence of men than of women.

Rodents left alone in a room with a man, or presented with a T-shirt worn by a man, had a sharp spike in the stress hormone corticosterone. And because the hormone acts as an analgesic, they also showed less response to pain. The rodents showed no such reaction to women; they were also less stressed when given a woman’s shirt together with a man’s.

The amount of stress felt by the rodents was “massive,” said Dr. Jeffrey Mogil, a psychologist at McGill University and an author of the study, comparable with being “in a very small tube so the mouse can’t move for 15 minutes.”

The findings, published in Nature Methods, could have far-reaching repercussions for research. Rodents account for more than 95 percent of all lab animals, according to the National Association of Biomedical Research. If a researcher’s sex might affect results, it should be considered a confounding factor, Mogil said.

– New York Times