Warmth and flowing water on early Mars were episodic

How to reconcile indisputable evidence of flowing water on Mars with severely low temperatures? New research shows volcanism and greenhouse gas could have warmed the planet sufficiently, but only for tens or hundreds of years at a time.
Adventures in research

Rich studies microbes 2,500 meters down on the sea floor

On Nov. 8, 2014, biologist Jeremy Rich cruised in the submersible Alvin through a “dream-like aquarium” of exotic life and lava formations on the Pacific sea floor. Rich and 54 colleagues are aboard a research vessel west of Costa Rica, studying the ecosystems of hydrothermal vents.

HIV risks high in Mexico City’s male sex trade

The prevalence of sexually transmitted infections, including HIV, and risky behavior are high among Mexico City’s male sex workers, a new study reports. Among the findings is that sex workers can make 34.5 percent more money for forgoing condoms. The researchers hope to counteract that incentive with one of their own.

Many older brains have plasticity, but in a different place

Brain scientists have long believed that older people have less of the neural flexibility (plasticity) required to learn new things. A new study shows that older people learned a visual task just as well as younger ones, but the seniors who showed a strong degree of learning exhibited plasticity in a different part of the brain than younger learners did.

Elderly brains learn, but maybe too much

Learning requires both mental flexibility, or “plasticity,” and stability. A new study finds that in learning a visual task, older people exhibited a surprising degree of plasticity, but had trouble filtering out irrelevant information, suggesting that their learning was not as stable.

Paramecia need Newton for navigation

While single-celled paramecia have the ability to respond to certain external stimuli, they appear not to use that sensory system for simple navigation, new research finds. The work suggests that the ability of paramecia to navigate around flat surfaces is entirely governed by Newton’s Third Law of Motion and not by active behavior. The finding, reported in Physical Review Letters, raises interesting evolutionary questions.

‘Come Sit a Spell’ at the Providence Public Library

Public Humanities students have created “Come Sit a Spell,” an interactive installation on display at the Providence Public Library that tells the story of the former West Elmwood neighborhood of Providence. The installation will be on display through Jan. 18, 2015.

Sleep starts later as teens age, but school still starts early

By following dozens of younger and older adolescents for more than two years, researchers in a new study were able to determine that the children fell asleep later and their circadian rhythms shifted later as they grew older. But early school start times interfere with their tendency to sleep later, reducing their total sleep. The study bolsters new recommendations for later school start times.