Metastasis of breast cancer occurs when cells move from the primary tumor to other parts of the body.

Children with autism spectrum disorder, a range of conditions characterized by social deficits and communication difficulties, were more likely to have been exposed to higher levels of certain air toxics during their mothers' pregnancies and the first two years of life compared to children without the condition, according to preliminary findings presented today at the American Association for Aerosol Research annual meeting in Orlando.

Other epidemiologists have linked everything from living near farms to organic food to autism, and such studies don't actually measure anything, they just find a map of autism and then correlate it to an environmental factor, in this instance pollution and autism instances in southwestern Pennsylvania.

By Alessandro R Demaio, Harvard University

There’s been a lot of discussion about obesity this week. Whether or not it’s a disease (as it is in the USA now) and how this label would positively or negatively influence action taken by society and governments in addressing this large and growing burden.

This conversation is important, but I have noticed very often it ends with confusion. Questions around why we begin talking about obesity - and end discussing mental health, cancer, heart disease or diabetes. To make things even more confusing, the term ‘Non-Communicable Diseases’ might even be mentioned.

By: Karin Heineman, Inside Science

(Inside Science TV) – Who can forget the winter of 2013-2014? Record-breaking cold temperatures and heavy snowfall hit from the Rocky Mountains all the way to the East Coast.

Although the majority of Americans still believe that global warming is happening, the especially blustery winter caused some people to question whether global warming is really happening.

“Almost invariably we find that after any winter a drop off in belief in the existence of global warming," said Barry Rabe, a political scientist at the University of Michigan in Ann Arbor.

America has a health care problem. It is excellent, the best in the world, but it is expensive. Rather than solving the problems of defensive medicine costs, designed to prevent lawsuits by conducting unnecessary tests, or tort reform to prevent lawyers from convincing people they are 'suing an insurance company' so the cost won't matter, America has instead created mandates so everyone is forced to buy insurance, and then subsidized people who can't afford it.

I am spending a few days in Aix Les Bains, a pleasant lakeside resort in the French southwest, to follow the works of the second ECFA workshop, titled "High-Luminosity LHC". ECFA stands for "European Committee for Future Accelerators" but this particular workshop is indeed centred on the future of the LHC, despite the fact that there are at present at least half a dozen international efforts toward the design of more powerful hadron colliders, more precise linear electron-positron colliders, or still other solutions.

The Ord River dam, completed in 1971, formed Australia's largest artificial lake in the far north west. Graeme Churchard/Flickr, CC BY-NC-SA

By Willem Vervoort, University of Sydney

Some 27 irrigation and dam projects are highlighted in the green paper for agricultural competitiveness released this week by agriculture minister Barnaby Joyce.

Science can't tell us exactly when the rising oceans will swallow up the Maldives, but it can give us a good idea. Credit: Hiroyuki-H, CC BY-SA

By Richard Pancost, University of Bristol and Stephan Lewandowsky, University of Bristol

Playing violent video games in 3-D makes everything seem more real –  and in a new study researchers found that people who played violent video games in 3-D showed more evidence of anger afterward than people who played games on 2-D systems. 

That may have troubling consequences for young players, according to an upcoming paper in Psychology of Popular Media Culture.

The Slave Trade painted by a French abolitionist artist.

By Daina Ramey Berry, University of Texas

People think they know everything about slavery in the United States, but they don’t.

They think the majority of African slaves came to the American colonies, but they didn’t. They talk about 400 hundred years of slavery, but it wasn’t. They claim all Southerners owned slaves, but they didn’t. Some argue it was a long time ago, but it wasn’t.