Heavy rain doesn't mean more trees in African savanna

In 2011, satellite images of the African savannas revealed a mystery: these rolling grasslands, with their heavy rainfalls and spells of drought, were home to significantly fewer trees than researchers had expected. Scientists supposed that the ecosystem's high annual precipitation would result in greater tree growth. Yet a 2011 study found that the more instances of heavy rainfall a savanna received, the fewer trees it had.

To this ecological riddle, Princeton University researchers might have finally provided a solution.

Mice stutter too

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.

Bees don't like diesels!

Diesel fumes may be reducing the availability of almost half the most common flower odours that bees use to find their food, new research has found.

The new findings suggest that toxic nitrous oxide (NOx) in diesel exhausts could be having an even greater effect on bees’ ability to smell out flowers than was previously thought.

NOx is a poisonous pollutant produced by diesel engines which is harmful to humans, and has also previously been shown to confuse bees’ sense of smell, which they rely on to sniff out their food.
 

"Good" cholesterol may not be so good after all for older women

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.

Volkswagen begins recalling diesels in Europe

The good news for Volkswagen is that it delivered almost 7.5 million vehicles to customers during the first three quarters of 2015. The bad news is that 8.5 million of VW’s cars will most likely be subject to a mandatory recall — and that’s just in Europe.

The fallout from the Volkswagen emissions scandal continues to reverberate, four weeks after revelations about the installation of “defeat device” software in diesel-powered cars slammed the newswires. Now, the world’s largest automaker is facing a global public relations crisis. This includes its home base: 2.8 million of the recalled vehicles were sold in Germany.

Global Ocean found in Saturn's Moon Enceladus

A global ocean lies beneath the icy crust of Saturn's geologically active moon Enceladus, according to new research using data from NASA's Cassini mission. 

Researchers found the magnitude of the moon's very slight wobble, as it orbits Saturn, can only be accounted for if its outer ice shell is not frozen solid to its interior, meaning a global ocean must be present. 

The finding implies the fine spray of water vapor, icy particles and simple organic molecules Cassini has observed coming from fractures near the moon's south pole is being fed by this vast liquid water reservoir. The research is presented in a paper published online this week in the journal Icarus.

Study points to new opportunities to fight cancer

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.

Dates of lunar impacts refined

Phenomenally durable crystals called zircons are used to date some of the earliest and most dramatic cataclysms of the solar system. One is the super-duty collision that ejected material from Earth to form the moon roughly 50 million years after Earth formed. Another is the late heavy bombardment, a wave of impacts that may have created hellish surface conditions on the young Earth, about 4 billion years ago.

Both events are widely accepted but unproven, so geoscientists are eager for more details and better dates. Many of those dates come from zircons retrieved from the moon during NASA's Apollo voyages in the 1970s.

Is tattoo ink safe?

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.

EPA and the regulation of greenhouse gasses

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.”