They hitchhike with us under the soles of our shoes and muddy car tires. Harsh and cold climates do not seem to stop alien plants from establishing themselves in high altitudes, where they now successfully penetrate the alpine vegetation, according to a study at Umeå University in Sweden and the University of Antwerp, Netherlands.

"Alien plants often gain advantages in their new environment because they lack natural enemies, and in this case the lack of strong competitors amongst alpine plants may be the key to success for generalist native species," says ecologist Ann Milbau, assistant professor at the research station Climate Impacts Research Centre in Abisko, Sweden.

It may seem like social media is a great way to engage people, but outside creating a flash mob of dancers or overthrowing an African dictatorship and replacing it with another one, armchair activists aren't accomplishing much.

'Talk is cheap', the saying goes, and retweets and likes are even cheaper. 

A number of people are concerned about BPA in plastics but that is far less warranted than concern about plastics themselves. 

In 1967's "The Graduate", the following conversation took place between an older man and the young protagonist:

McGuire: I just want to say one word to you. Just one word. 
Benjamin: Yes, sir. 
McGuire: Are you listening? 
Benjamin: Yes, I am. 
McGuire: Plastics.

Lower incomes are associated with higher obesity, though lower income in America is very much a relative term. Poor and minority kids lead the country in bedroom television ownership, so being poor in the US is not the same as in other countries.

With over one-third of American children overweight, the search is on to figure out why. Happy Meals get blamed, as do sodas, trans fats and just about everything else.

A new study even blames television - not necessarily how much time is spent watching it, but having it in the bedroom. The paper in JAMA associated a bedroom television with weight gain in children and adolescents, and say it is unrelated to the time they spend watching.

Maybe photosynthesis can be improved.

That may sound like blasphemy but the easy solution to growing more food is teaching crop plants to concentrate carbon dioxide in their leaves. That could increase photosynthetic efficiency by 60 percent and yields by as much as 40 percent, according to a new study.