Science

Populations of frogs, salamanders and other amphibians are declining at an average rate of 3.7 percent each year, according to a U.S. Geological Survey study released this week. Researchers say the study is the first to calculate how quickly amphibians are disappearing in the United States.

"If the rate observed is representative and remains unchanged, these species would disappear from half of the habitats they currently occupy in about 20 years," according to the USGS.

North Carolina State University biologist Rob Dunn and colleagues surveyed people's pillow cases, refrigerators, toilet seats, TV screens and other household spots, to learn about the microbes that dwell in our homes. Among the findings, reported in the journal PLoS One, homes with dogs had more diverse bacterial communities, and higher numbers of "dog-associated" bacteria.

Smartphones, tablets and computers could help seniors stay connected to their communities and families. But a hefty price tag, steep learning curves, and designs meant for younger eyes and hands could keep some older adults from logging on. Guests discuss the best ways for seniors to tackle new technology, and how devices can be adapted to accommodate older users.

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FLORA LICHTMAN, HOST:

Last year scientists reported that a skin cancer drug appeared to reverse the effects of an Alzheimer's-like disease in mice. But four studies out this week in Science question the original results. Ronald Petersen, director of the Mayo Clinic's Alzheimer's Disease Research Center, talks about the new findings, and the hunt for Alzheimer's drugs.

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FLORA LICHTMAN, HOST:

This is SCIENCE FRIDAY. I'm Flora Lichtman. You've likely heard of the legendary explorers Lewis and Clark, but maybe not of the U.S. Army explorer Stephen Harriman Long, an engineer who led a scientific expedition through the Great Plaines 15 years after Lewis and Clark.

His expedition traveled through Oklahoma, Kansas and Nebraska. And what did his crew make of America's Breadbasket? A place wholly unfit for cultivation or agriculture, they said. On a map, the explorers labeled the Great Plains as the Great American Desert.

In parts of the southeastern US, aggressive fire ants have been driven out by an even more recent arrival, the tawny crazy ant. Edward LeBrun, a researcher at the University of Texas at Austin, describes the newcomers and how one invasive species can out-invade another.

Part 1 of the TED Radio Hour episode Memory Games.

About Scott Fraser's TEDTalk

Forensic psychologist Scott Fraser studies how we remember crimes. He describes a deadly shooting and explains how eyewitnesses can create memories that they haven't seen. Why? Because the brain is always trying to fill in the blanks.

About Scott Fraser

Part 2 of the TED Radio Hour episode Memory Games.

About Daniel Kahneman's TEDTalk

Nobel laureate and founder of behavioral economics Daniel Kahneman goes through a series of examples of things we might remember, from vacations to colonoscopies. He explains how our "experiencing selves" and our "remembering selves" perceive happiness differently.