Science Briefs: Why females rule in lemur land

Why female lemurs rule their roost: more male hormones

Males rule in most of the animal world. But when it comes to conventional gender roles, lemurs buck the trend. It’s not uncommon for lady lemurs to bite their mates, snatch a piece of fruit from their hands, whack them in the head or shove them out of prime sleeping spots. Females mark their territories with distinctive scents just as often as the males do. Males often don’t take their share of a meal until the females have had their fill.

But female dominance in lemurs remains a puzzle. Female lemurs are no bigger than males, and have no physical edge over their mates.

Researchers at the Duke University Lemur Center say females have significantly lower testosterone levels than the males across the board. But when they compared six lemur species, they found that females of some species have higher testosterone levels than others.

It could be that females are more sensitive to the effects of testosterone than males, stimulating aggressive behavior even though males still have more of the hormone, according to Joseph Petty, a recent doctoral student involved in the research. The results appear online in the journal Scientific Reports.

Lemurs and lorises split off from the rest of the primate family tree more than 60 million years ago. duke.edu

Taste of tomato juice soars at 30,000 feet

If you’re planning to fly, plan to drink some tomato juice. While examining how airplane noise affects the palate, food scientists at Cornell University in New York found sweetness suppressed and a tasty, tender tomato surprise: umami.

umami – a Japanese scientific term – describes the sweet, savory taste of amino acids such as glutamate in foods like tomato juice, and according to the new study, in noisy situations – like the 85 decibels aboard a jetliner – umami-rich foods become your taste bud’s best buds.

“Our study confirmed that in an environment of loud noise, our sense of taste is compromised. Interestingly, this was specific to sweet and umami tastes, with sweet taste inhibited and umami taste significantly enhanced,” said Robin Dando, assistant professor of food science.

The study Dando co-authored was published in the online edition of the Journal of Experimental Psychology: Human Perception and Performance. cornell.edu

You could be wired for success if you stopped smoking

Smokers who are able to quit might actually be hard-wired for success, according to a study from Duke University Medical Center.

The study, published in Neuropsychopharmacology, showed greater connectivity among certain brain regions in people who successfully quit smoking compared to those who tried and failed.

The researchers analyzed MRI scans of 85 people taken one month before they attempted to quit. All participants stopped smoking and the researchers tracked their progress for 10 weeks. Looking back at the brain scans of the 44 smokers who quit successfully, the researchers found they had something in common before they stopped smoking – better synchrony (coordinated activity) between the insula, home to urges and cravings, and the somatosensory cortex, a part of the brain central to our sense of touch and motor control.

The study’s lead author was Duke assistant professor Merideth Addicott. dukemedicine.org

This story was originally published May 17, 2015 at 3:13 AM with the headline "Science Briefs: Why females rule in lemur land."