There are lots of distance runners in the United States, there is no real gender gap about participation. But there is when it comes to competition, the difference is there.

A new paper in Evolutionary Psychology says that, on average, American men participate at track meets about three times as often as American women, and this difference has been consistent since the late 1990s. By contrast, at road races, the sex difference in participation has disappeared.

In the past, researchers have primarily used the genetic history of mothers to understand evolution in animals, but a new study has investigated ancestry across the red fox genome, including the Y chromosome (paternal line) and  found some surprises about the origins, journey and evolution of the red fox, the world's most widely distributed land carnivore.

Conventional thinking based on maternal genetics suggested that red foxes of Eurasia and North America composed a single interconnected population across the Bering land bridge between Asia and Alaska.

Isamu Akasaki, Hiroshi Amano and Shuji Nakamura have been award the 2014 Nobel Prize in Physics "for the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources". Using blue LEDs, white light can be created in a new way and that means LED lamps, which are longer-lasting and more efficient than incandescent sources.

Sodium is back in the health concern cycle and an analysis of data in the federal nationwide dietary intake survey known as "What We Eat in America NHANES 2009-2010," has led a team of Department of Agriculture (USDA) to conclude that, on any given day 49 percent of U.S. adults eat at least one sandwich, and sandwiches account for 20 percent of total daily sodium intake. 

No one is seriously expecting to overturn Einstein's idea of time dilation, and instead the goal is often to find the possible limits. That means looking for deviations in experiments with increasing precision or under extreme conditions. 

Seven Swedish women have had embryos reintroduced after receiving wombs from living donors and now one has delivered a healthy and normally developed boy, reveals the case study in The Lancet.

The uterus transplantation research project at the University of Gothenburg started in 1999 and the goal has been to enable women who were born without a womb or who have lost their wombs in cancer surgery to give birth to their own children.

Nine women in the project have received a womb from live donors – in most cases the recipient's mother but also other family members and close friends. The transplanted uterus was removed in two cases, in one case due to a serious infection and in the other due to blood clots in the transplanted blood vessels.