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.

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. 

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. 

It’s that time of the year again. You probably think I mean Christmas, but as a virologist the sight of glitter, fairy lights and moulting pine trees immediately makes me think of the flu season. And if there’s one thing that can ruin your family’s Christmas, it’s the arrival of that particular unwanted guest.

But there are lots of myths around about flu. Here’s a quick guide to some common knowledge that actually turns out to be wrong.

A new paper has found that inhibiting or blocking stem cells ability to make a specific decision, leads to better cell growth and could lead to defined ways to differentiate stem cells.

Th authors say their research is the first comprehensive analysis of a pathway important for stem and cancer cell decisions known as Erk. As a result, they hope the work could contain clues to cancer treatment as well as helping to establish a platform to make stem cell treatments for gut related disorders like the pancreas or the liver. 

Despite a malfunction that ended its primary mission in May 2013, the Kepler spacecraft is still alive and working and its data has found a new "super-Earth".

NASA's Kepler spacecraft detected planets by looking for transits, when a star dims slightly as a planet crosses in front of it. The smaller the planet, the weaker the dimming, so brightness measurements must be precise and that requires maintaining a steady pointing. Kepler can't really do that any more, its primary functionality came to an end when the second of four reaction wheels used to stabilize the spacecraft failed. Without at least three functioning reaction wheels, Kepler couldn't be pointed accurately.

Hydrogen peroxide (H2O2) is a strong oxidizer. You may know it as a wound disinfectant or as a bleaching agent for hair and teeth but it is also created naturally in our bodies, as part of our cellular oxidation.

H2O2 belongs to a group of natural chemicals called reactive oxygen species (ROS) and when the process gets out of hand, too much oxidation can have a damaging effect on cells and their components. Unchecked free radicals, the most well-known ROS, are believed to play a role in carcinogenesis, degenerative diseases, and even aging. To prevent that, our cells also contain antioxidant enzymes known as peroxiredoxins that degrade H2O2 molecules. We don't want to have no H202, despite the chemophobia of environmental and food activists, we want just enough.

By Tim Trudgian, Australian National University

Imagine you are captain of the national cricket team. With 20 minutes left in day one of a test match, your top-order batsman is dismissed. Do you employ a nightwatchman? That is, do you send in a tail-end batsman to see out the bowling until the end of the day’s play and protect your top-order?

Well, a little bit of math can show you that you shouldn't.