If you have traveled, you know that in some other countries the voltage used in homes and businesses are different than where you live. But not the type of electricity; all countries use alternating current. Yet a lot of appliances and devices then convert it to DC.

In the early days of electricity, the war was on between alternating current and direct, with Westinghouse (and Tesla) advocating the former and Thomas Edison standardizing on the latter. The reason alternating current won is because people didn't want power plants in their neighborhoods and banks of batteries in their homes. And centralized power without extreme line loss meant high frequency, requiring transformers to step the current up and then back down at homes.

Researchers have linked Prevotella copri, a species of intestinal bacteria, to the onset of rheumatoid arthritis, the first demonstration in humans that the chronic inflammatory joint disease may be mediated in part by specific intestinal bacteria.

Everyone has a hypothesis about the 'birthplace of life' and a new paper adds clay to that list.

In simulated ancient seawater, clay forms a hydrogel, a mass of microscopic spaces capable of soaking up liquids like a sponge. Over billions of years, chemicals confined in those spaces could have carried out the complex reactions that formed proteins, DNA and eventually all the machinery that makes a living cell work.

Clay hydrogels could have confined and protected those chemical processes until the membrane that surrounds living cells developed, according to the computer model.

A new study correlates a series of small earthquakes near Snyder, Texas between 2006 and 2011 with the underground injection of large volumes of carbon dioxide (CO2), long before the adoption of current hydraulic fracking and a finding that is relevant to the process of capturing and storing CO2 underground.  

There's good news and there's bad news to deliver. Which do you want to give first? What if you are getting it? The best strategy depends on whether you are the giver or receiver of the bad news, and if the news-giver wants the receiver to act on the information, according to a new paper.

The process of giving or getting bad news is difficult for most people, particularly when news-givers feel unsure about how to proceed with the conversation, psychologists Dr. Angela M. Legg and Professor Kate Sweeny note. "The difficulty of delivering bad news has inspired extensive popular media articles that prescribe 'best' practices for giving bad news, but these prescriptions remain largely anecdotal rather than empirically based."

Researchers in a new paper say that one way to gauge the extent of prescription opioid pain reliever abuse is to count the number of health care providers.