Several months back, a Berkeley undergraduate began witnessing distinctly odd behavior in frogs she was caring for in the lab. At about 18-months old, some frisky guys began regularly mounting tank mates, as if to copulate. Except that their chosen partner was invariably male. He had to be. Because genetically, every animal in the tank was male.

Over the past two decades, science literacy in the United States – an estimate of the share of adults who can follow complex science issues and maybe even render an informed opinion on them – has nearly tripled. But – and it’s a big but -- the proportion of people who fall into this category remains small. Just 28 percent.

Most people, on average, drive their cars only an hour or two a day. The rest of the time, those pricey vehicles sit parked on the street or in some garage. But if those cars had a big bank of batteries – typical of today’s gasoline hybrids or soon-to-hit-the-road plug-in hybrids – they could be earning their owners money while sitting parked. Maybe $5 to $10 a day, just by serving as a back-up energy-storage system for the electric-utility grid.

A computer simulation finds that leaves' circular networks are efficient at getting around damaged spots and varying distribution load.