A study of nearly 1,000 teens found that sexually active obese adolescents were significantly less likely to use contraception than normal weight peers, putting them at higher risk of unintended pregnancy. Obese adolescents who did use contraception were also less likely to use it consistently, according to the paper. 

Researchers analyzed 26,545 weekly journal surveys measuring sexual practices and contraceptive use from a longitudinal study of 900 women ages 18-19 in Michigan. They examined the association between weight and sexual behaviors.

There is a paradox when it comes to guns in America. In states like California, gun ownership has doubled in the last 15 years while murder rates dropped substantially in that time. Today,
almost one in three US adults owns at least one gun, and owners are more likely to be white married men over the age of 55, hardly a high crime demographic.

Instead of being for crime, most guns are used for suicide - and even then fewer people commit suicide with guns in the US than do by hanging in Japan. Though Switzerland had always scoffed at the notion that guns cause crime - gun ownership is even higher there - similar results in more than one country dispel the myth that more legal guns lead to more crime or more murders.

A federal preschool program did more than improve educational opportunities for poor children in Mississippi during the 1960s - it created activists. 

A team of bioengineers at Brigham and Women's Hospital (BWH), led by Ali Khademhosseini, PhD, and Nasim Annabi, PhD, of the Biomedical Engineering Division, has developed a new protein-based gel that, when exposed to light, mimics many of the properties of elastic tissue, such as skin and blood vessels. In a paper published in Advanced Functional Materials, the research team reports on the new material's key properties, many of which can be finely tuned, and on the results of using the material in preclinical models of wound healing.

Pink salmon that begin life in freshwater with high concentrations of carbon dioxide, which causes acidification, are smaller and may be less likely to survive, according to a new study.

The risks of ocean acidification on marine species have been studied extensively but the impact of freshwater acidification is not well understood. The study is one of the first to examine how rising carbon dioxide levels caused by climate change can impact freshwater fish.

Cancer cells play it dirty to get what they want. They are survival artists with a strong criminal streak. They surround themselves with a protective shield of extra-cellular material and then secure supply lines by attracting new blood vessels.

To achieve both of these aims, they set immune cells a honey trap by releasing attractants in the form of messenger molecules which lure immune cells to growing tumours. At the cancer site, the abducted immune cells release growth hormones to guide new blood vessels to the tumour and help build a protective shield.