Auroras are the most visible manifestation of the sun's effect on Earth, but many aspects of these spectacular displays are still poorly understood.

One particular type of very high-latitude aurora is known as a theta aurora -- seen from above it looks like the Greek letter theta, an oval with a line crossing through the center -- which sometimes occurs closer to the poles than normal aurora. While the genesis of the auroral oval emissions is reasonably well understood, the origin of the theta aurora has been undetermined.

Predictions about specific effects of climate change were once common - but they turned out to be spectacularly wrong so there are fewer these days. In 2006, former Vice-President Al Gore said by 2016 it would be too late to do anything, while the Intergovernmental Panel on Climate Change (IPCC) said African farmers would be suffering 50% yield drops by 2020 and the Himalayan glaciers would be gone by 2035. 

Today, the IPCC is more scientific and cautions against attributing specific weather events to global warming. They recognize that the public loses confidence in science itself when scientists engage in advocacy. But without reliable metrics, it is hard to know how pressing the issue is so someone has to put in some numbers. 

City folk may not think much of rural living - but they are healthier.

A new study finds that diabetes, once rather uncommon, is now affecting 387 million people worldwide - and 77 percent of it is in developed nations.

The reason is stress, write the authors of a paper in the Journal of Clinical Endocrinology&Metabolism. City life - noise, crime and traffic all lead to higher stress and the body producing more of the stress hormone cortisol. Cortisol can counteract insulin, the hormone that regulates blood sugar, and slow the body's production of it and that makes people more susceptible to diabetes. 

Computers don't really boot up any faster than they have in decades and that is due to limitations in electric currents (and ignoring the bloated software rolled out after every new chip), which are also a significant power drain.

The solution may be on the horizon. A team has created a room-temperature magnetoelectric memory device, equivalent to one computer bit, that could lead to next-generation nonvolatile memory: magnetic switchability, in two steps, with nothing but an electric field. When data can be encoded without current - for example, by an electric field applied across an insulator - it requires much less energy and that means low-power, instant-on computing is a reality.

There is a running joke in America that there are three times as many people in the U.S. claiming to be Irish as there are actual people in Ireland. 

Though it's nice to claim to be Irish because of a last name, America is a melting pot. And it is so melted that the genetic ancestry of racial and ethnic groups varies significantly even across different geographic regions in the United States. A paper in the American Journal of Human Genetics, researchers analyzed the genomes of more than 160,000 African-Americans, Latin-Americans and European-Americans, providing insights into the subtle differences in genetic ancestry across the United States. 

Climate change impacts could mean uncertain transformations of global agriculture systems by 2050, according to a new paper from the International Institute for Applied Systems Analysis.