New evidence gathered by NASA's MESSENGER spacecraft at Mercury solves an apparent enigma about Mercury's evolution. 

The data indicate the tiny planet closest to the sun, only slightly larger than earth's moon, has shrunk up to 7 kilometers in radius over the past 4 billion years, much more than earlier estimates. Older images of surface features indicated that, despite cooling over its lifetime, the rocky planet had barely shrunk at all. But modeling of the planet's formation and aging could not explain that finding.

Colon cancer incidence rates have dropped sharply - 30 percent in the U.S. in the last 10 years, among adults 50 and older.

The drop has been attributed to the widespread uptake of colonoscopy, with the largest decrease in people over age 65. Colonoscopy use has almost tripled among adults ages 50 to 75, from 19 percent in 2000 to 55 percent in 2010.

The findings come from Colorectal Cancer Statistics, 2014, and are published in CA: A Cancer Journal for Clinicians. The article and its companion report, Colorectal Cancer Facts&Figures, were released today by American Cancer Society researchers as part of a new initiative by the National Colorectal Cancer Roundtable to increase screening rates to 80 percent by 2018.

Leftover cigarette smoke clings to walls and furniture and could pose a far more serious threat, according to a presentation at the National Meeting&Exposition of the American Chemical Society (ACS) which says that one compound from this "third-hand smoke" can damage DNA and and even potentially cause cancer. 

Bo Hang, Ph.D., of Lawrence Berkeley National Laboratory noted that the idea of third-hand smoke only come into existence in 2009, But that evidence already suggests it could threaten human health. In test tubes, anyway.

"The best argument for instituting a ban on smoking indoors is actually third-hand smoke," said Hang.

Babies are born with the ability to digest lactose, the sugar found in milk, but most humans lose this ability after infancy because of declining levels of the lactose-digesting enzyme lactase. Most mammals also do not drink milk after weaning.

So did maintaining a high level of lactase confer an evolutionary advantage - reaping the nutritive benefits of milk - or is lactase persistence (lactose tolerance) simply due to dairy culture shaping?

(Santa Barbara, Calif.) — Shame on you. These three simple words can temporarily — or, when used too often, permanently — destroy an individual's sense of value and self-worth.

"In modernity, shame is the most obstructed and hidden emotion, and therefore the most destructive," said Thomas Scheff, professor emeritus of sociology at UC Santa Barbara. "Emotions are like breathing — they cause trouble only when obstructed."

When hidden, he continued, shame causes serious struggles not only for individuals but also for groups. In an article published in the current issue of the journal Cultural Sociology, Scheff examines the ubiquity of hidden shame and suggests it may be one of the keys to understanding contemporary society.

Whether you're a Major League outfielder chasing down a hard-hit ball or a lesser mortal navigating a busy city sidewalk, it pays to keep a close watch on your surroundings when walking or running. Now, new research by UC San Francisco neuroscientists suggests that the body may get help in these fast-changing situations from a specialized brain circuit that causes visual system neurons to fire more strongly during locomotion.

There has been a great deal of research on changes among different brain states during sleep, but the new findings, reported in the March 13 issue of Cell, provide a compelling example of a change in state in the awake brain.