Radioactive contamination following a nuclear power-plant disaster in Japan never reached unsafe levels in the north Pacific Ocean for either marine life or human health, says a British Columbia scientist.

Chemical oceanographer Jay Cullen of the University of Victoria has monitored levels of contamination from radioactive isotopes, used in cancer therapies and medical imaging, since the meltdown of three reactors at the Fukushima Daiichi plant in 2011 following a tsunami triggered by an earthquake. Read more.

We humans are unusual amongst primates: We're bipedal, we have a virtuosic proficiency for language, we're able to understand the mental states of others. Recent studies have also found that the social behavior of the sexes in ancient humans were probably unlike those of what we most often see today in the great apes — in at least some early humans, the males stayed put in one geographic area while females traveled around looking for new mates. Read more.

Scientists at the National Institute of Standards and Technology (NIST) have developed a laboratory instrument that can measure how much of the carbon in many carbon-containing materials was derived from fossil fuels. This will open the way for new methods in the biofuels and bioplastics industries, in scientific research, and environmental monitoring. Among other things, it will allow scientists to measure how much of the carbon dioxide (CO2) in the atmosphere came from burning fossil fuels, and to estimate fossil fuel emissions in an area as small as a city or as large as a continent. Read more.