The Discovery Files

What makes someone better at switching between different tasks? Looking for the mechanisms behind cognitive flexibility, researchers at the University of Pennsylvania and Germany's Central Institute of Mental Health in Mannheim and Charit? University Medicine Berlin have used brain scans to shed new light on this question. By studying networks of activity in the brain's frontal cortex, a region associated with control over thoughts and actions, the researchers have shown that the degree to which these networks reconfigure themselves while switching from task to task predicts people's cognitive flexibility.

For over 30 years, Terrie Williams has been studying exercise physiology in wild animals: African lions and wild dogs, dolphins and whales, coyotes and mountain lions, as well as a few human athletes. She has put mountain lions on treadmills and strapped heart-rate monitors onto big-wave surfers at Mavericks. These studies have given Williams, a professor of ecology and evolutionary biology at UC Santa Cruz, a unique perspective on exercise and health.

Nanoengineers at the University of California, San Diego used an innovative 3D printing technology they developed to manufacture multipurpose fish-shaped microrobots--called microfish--that swim around efficiently in liquids, are chemically powered by hydrogen peroxide and magnetically controlled. These proof-of-concept synthetic microfish will inspire a new generation of "smart" microrobots that have diverse capabilities such as detoxification, sensing and directed drug delivery.

A new study of 270 high school students shows that three times as many girls were interested in enrolling in a computer science class if the classroom was redesigned to be less "geeky" and more inviting. The results, by University of Washington researchers, reveal a practical way for teachers to help narrow the gender gap in computer science by helping girls feel that they belong.

For decades, a particular class of toxic chemicals was added to everything from clothing to carpeting to fire-fighting foams to make them stain- or water-resistant or nonstick--until scientists discovered the compounds were toxic. Since learning of their hazardous nature, U.S. companies have largely stopped using the compounds. But how can we be sure that the raw materials those companies obtain, like the fabric for a shirt, aren't already tainted with them? Graham Peasely, a chemistry professor at Hope College, found an answer in nuclear physics.

A study at Oregon State University indicates that both a high-fat and a high-sugar diet, compared to a normal diet, cause changes in gut bacteria that appear related to a significant loss of "cognitive flexibility," or the power to adapt and adjust to changing situations. This effect was most serious on the high-sugar diet, which also showed an impairment of early learning for both long-term and short-term memory.

People aren't the only ones who perform better on tests or athletic events when they are just a little bit nervous--dogs do too. But in dogs as in people, the right amount of stress depends on disposition. A new study by researchers at Duke University finds that a little extra stress and stimulation makes hyper dogs crack under pressure but gives mellow dogs an edge.

Cavitation bubbles: They can damage boat propellers. They can help break up kidney stones. Now, with the help of a high-speed camera, engineers at Virginia Tech have made a discovery about the bubbles' destructive power that could lead to several unexpected uses.

Rice University engineers have demonstrated the first system that allows wireless data transmissions over UHF channels during active TV broadcasts. If the technology were incorporated into next-generation TVs or smart remotes, it could significantly expand the reach of so-called "super Wi-Fi" networks in urban areas.

Blame smartphone alerts, constant connectivity and a deluge of media for our society's sleep deprivation. But the root cause of why we get less sleep now than our ancestors did could come down to a much simpler reason: Artificial light. New research from the University of Washington comparing traditional hunter-gatherer living conditions to a more modern setting shows that access to artificial light and electricity has shortened the amount of sleep humans get each night.

The mantis shrimp is able to repeatedly pummel the shells of prey using a hammer-like appendage that can withstand rapid-fire blows by neutralizing certain frequencies of "shear waves," according to a new research paper by the University of California, Riverside, and Purdue University engineers. The club is made of a composite material containing fibers of chitin, the same substance found in many marine crustacean shells and insect exoskeletons but arranged in a helicoidal structure that resembles a spiral staircase.

University of Delaware (UD) researchers have discovered a soil microbe that mobilizes an "iron shield" to block the uptake of toxic arsenic in rice. Arsenic occurs naturally in rocks and soils, air and water, plants and animals. It's used in a variety of industrial products and practices, from wood preservatives, pesticides and fertilizers, to copper smelting. Chronic exposure to arsenic has been linked to cancer, heart disease and diabetes. The UD finding gives hope that a natural, low-cost solution--a probiotic for rice plants--may be in sight to protect this global food source from accumulating harmful levels of one of the deadliest poisons on the planet. Rice currently is a staple in the diet of more than half the world's population.

Though people can distinguish between millions of colors, we have trouble remembering specific shades because our brains tend to store what we've seen as one of just a few basic hues, a Johns Hopkins University-led team discovered. Researchers led by cognitive psychologist Jonathan Flombaum dispute standard assumptions about memory, demonstrating for the first time that people's memories for colors are biased in favor of "best" versions of basic colors over colors they actually saw.

Researchers at Columbia University have designed a new technique to create a single-molecule diode, and, in doing so they have developed molecular diodes that perform 50 times better than all prior designs.

If you thought that a beetle with a machine gun built into its rear end was something that only exists in sci-fi movies, you should talk to Wendy Moore at the University of Arizona. Many beetles secrete foul-smelling or bad-tasting chemicals from their abdomens to ward off predators, but bombardier beetles take it a step further. When threatened, they combine chemicals in an explosive chemical reaction chamber in their abdomen to simultaneously synthesize, heat and propel their defensive load as a boiling hot spray, complete with "gun smoke."