When the plague swept through Europe in 1665, no one could figure out how the devastating disease spread. But after a tailor in the small village of Eyam in central England died that September, people eventually put two and two together. He had received a parcel of cloth infested with fleas just 4 days before dying of bubonic plague. Within a month, five other villagers had succumbed, and the local vicar convinced the town to voluntarily put itself under quarantine. It eventually became clear that it was fleas, probably on rats, that spread the plague so far and so quickly.

But now it appears that the plague did not always infect fleas—and the disease may not have always spread so rapidly or been as devastating. A new study of ancient DNA from the teeth of 101 Bronze Age skeletons has found that seven people living 2800 to 5000 years ago in Europe and Asia were infected with Yersinia pestis, the bacteria that causes the plague. 

As debate roils over EPA regulations proposed this month limiting the release of the potent greenhouse gas methane during fracking operations, a new University of Vermont study funded by the National Science Foundation shows that abandoned oil and gas wells near fracking sites can be conduits for methane escape not currently being measured.

The study, to be published in Water Resources Research on October 20, demonstrates that fractures in surrounding rock produced by the hydraulic fracturing process are able to connect to preexisting, abandoned oil and gas wells, common in fracking areas, which can provide a pathway to the surface for methane.

A recent paper published in the Proceedings of the National Academies of Science showed that methane release measured at abandoned wells near fracking sites can be significant but did not investigate how the process occurs.

About 70 million people worldwide stutter when they speak, and it turns out humans aren’t the only ones susceptible to verbal hiccups. Scientists at this year’s Society for Neuroscience Conference in Chicago, Illinois, show that mice, too, can stumble in their vocalizations. In humans, stuttering has long been linked to a mutation in the “housekeeping” gene Gnptab, which maintains basic levels of cellular function. To cement this curious genetic link, researchers decided to induce the Gnptab “stutter mutation” in mice. They suspected the change would trigger a mouse version of stammering. But deciphering stuttered squeaks is no easy task, so researchers set up a computerized model to register stutters through a statistical analysis of vocalizations.

Researchers in the United States have found that hormonal changes in women during the menopause can cause so-called ‘good cholesterol’ to become dangerous to their health. EurActiv France reports. 

'Good cholesterol' usually protects the arteries by helping to transport 'bad cholesterol' to the liver to be processed. But recent research in the United States suggests that the risk of heart disease in women increases dramatically after the menopause, because even good cholesterol becomes harmful.

According to the ten-year study carried out on 1,054 American women by Karen Matthews, of the University of Pittsburgh, women's cholesterol levels tend spike after the menopause, placing them at greater risk of cardiovascular events.

New research by Dana-Farber Cancer Institute scientists raises the prospect of cancer therapy that works by converting a tumor's best friends in the immune system into its gravest enemies.

In a study published in the journal Science, an international collaboration of investigators from Dana-Farber, Harvard Medical School, Boston Children's Hospital, and the University of Strasbourg uncovered a mechanism that allows key immune system cells to keep a steady rein on their more belligerent brother cells, thereby protecting normal, healthy tissue from assault. The discovery has powerful implications for cancer immunotherapy researchers say: by blocking the mechanism with a drug, it may be possible to turn the attack-suppressing cells into tumor-attacking cells.

Tattoos really are more than skin deep—and that raises questions about their safety.

Many people enjoy the aesthetic beauty of tattoos. But the brightly colored inks that make tattoos so vibrant and striking also carry health concerns, report authors of a new paper related to tattoo safety.

According to the Pew Research Center, 45 million Americans have at least one tattoo; roughly $1.65 billion is spent on tattoos each year in the U.S.

This week, EPA Administrator Gina McCarthy joined private and public sector leaders for a second annual White House roundtable discussion about the progress made and new steps taken to curb emissions of hydrofluorocarbons (HFCs), potent greenhouse gases used in refrigeration and air conditioning. Administrator McCarthy announced several new actions the agency will take to help support a smooth transition to climate-friendly alternatives to HFCs.

"EPA is working closely with industry leaders to reduce greenhouse gas emissions, transition to climate-friendly refrigerants, and deploy advanced refrigeration technologies,” said EPA Administrator Gina McCarthy. “The powerful combination of EPA’s regulatory actions and innovations emerging from the private sector have put our country on track to significantly cut HFC use and deliver on the goals of the President’s Climate Action Plan.”

Although researchers have known since 1999 that traces of the Ebola virus could remain in semen for months, two papers published in The New England Journal of Medicine today offer more detail about the frightening possibility that survivors of an infection could rekindle outbreaks. One study focuses on nearly 100 men in Sierra Leone who survived the dreaded viral illness, whereas the second one documents a clear case of sexual transmission of Ebola virus.

In the Sierra Leone study, researchers found Ebola viral RNA in semen samples from almost half the 93 men they tested.  The likelihood of finding viral RNA declined as time from disease onset increased: All nine men who were tested 2 to 3 months after they fell ill had evidence of Ebola RNA in their semen, but the researchers  found it in only 26 of 40 men whose infections had started 4 to 6 months earlier and in 11 of 43 men whose infections had started 7 to 9 months earlier. The result from one Ebola patient tested 10 months after disease onset was indeterminate.

Ever since human beings first began climbing the world's tallest mountains, they have struggled with a basic problem: altitude sickness, caused by lower air pressures which affect the ability of our bodies to take up oxygen. 

Or, as actor Jason Clarke says in his role as the climbing guide Rob Hall in the recently released movie, Everest, "Human beings simply aren't built to function at the cruising altitude of a 747." 

Why elephants rarely get cancer is a mystery that has stumped scientists for decades. A study led by researchers at Huntsman Cancer Institute (HCI) at the University of Utah and Arizona State University, and including researchers from the Ringling Bros. Center for Elephant Conservation,may have found the answer.