Memristor Made

After nearly 40 years, scientists have constructed a new addition to the stable of circuit elements (inductors, capacitors and resistors). Called the memristor, or memory resistor, it is a nanometer-scale electric switch that “remembers” whether it is on or off after its power is turned off. It might become a useful tool for constructing nonvolatile computer memory or for packing transistors together more densely to make smaller chips. A Hewlett-Packard team crafted the device by inserting a layer of titanium dioxide as thin as three nanometers between a pair of platinum layers. —JR Minkel

Concrete Math Learning

Abstract examples are more effective than practical problems for teaching math concepts. Researchers at the Ohio State University taught one group of students a new mathematical system using symbols, such as circles and diamonds, and another group using scenarios, such as combining liquids in measuring cups. Students who learned using symbols scored 80 percent on a test requiring them to apply their knowledge in a novel situation; the others scored between 40 and 50 percent. —Nikhil Swaminathan

Toasted Bugs

Although climate change will likely raise temperatures more in temperate and polar regions than in equatorial zones, tropical insects may suffer more than their counterparts in cooler climes. Used to thriving in a narrow temperature range, tropical insects may be more sensitive to shifts—they already live in conditions that verge on being too hot for them, a recent study finds. Insects in temperate areas, however, will probably thrive with an extra bit of warming. —David Biello