Why do babies smile when they interact with their parents? Could their smiles have a purpose? A team of computer scientists, roboticists and psychologists say they can confirm what most parents already suspect: when babies smile, they do so with a purpose--to make the person they interact with smile in return. 

In addition, babies reach that goal by using sophisticated timing, much like comedians who time their jokes to maximize audience response. But there is a twist: babies seem to be doing this while smiling as little as possible.

Scientists successfully defeated a dangerous intestinal pathogen, Clostridium difficile, with a drug targeting its toxins rather than its life.

C. difficile is responsible for more than 250,000 hospitalizations and 15,000 deaths per year in the United States, costing the country more than $4 billion in health-care expenses, said the study's senior author, Matthew Bogyo, PhD, professor of pathology and of microbiology and immunology at Stanford University School of Medicine. Lead authorship of the study is shared by Kristina Bender, PhD, a former postdoctoral scholar in Bogyo's lab, and Megan Garland, a student in the Medical Scientist Training Program.

Targeting sitting time, rather than physical activity, is the most effective way to reduce prolonged sitting, according to the first comprehensive review of strategies designed to reduce sitting time.  

Prolonged sitting has become a serious public health concern, with modern lifestyles becoming increasingly sedentary and many professions requiring workers to sit for most of the day. Previous studies and reviews have shown that higher levels of sitting are linked with cancer, diabetes, heart disease and even an early death, independently of whether a person takes regular exercise. Public health interventions have the potential to reduce prolonged sitting, but until now, little has been known about what makes certain sitting reduction strategies effective.

Like a spicy food? A recent study suggests you may live longer.

Tulane University epidemiologist Dr. Lu Qi co-led the study of more than 500,000 Chinese adults over seven years. The results indicated that participants who ate foods flavored with chili peppers every day reduced their risk of premature dying by 14 percent, as compared to people who ate chili peppers less than once a week.

High circulating levels of cardiovascular hormones/peptides in cancer patients have been linked to shorter survival, regardless of disease type and stage of progression in a new paper.

These chemicals, known as biomarkers, are apparent in the absence of any clinical signs of heart disease or infection, and before the start of anti-cancer treatment, some of which is known to damage heart tissue, say the researchers.

Levels of cardiovascular hormones/peptides have been used to monitor the severity and progression of heart tissue damage as a result of either chemotherapy or radiotherapy. But what has not been clear is whether the cancer itself may affect the levels of these chemicals.

About 20 million years ago a single flea became entombed in amber with tiny bacteria attached to it, providing what researchers believe may be the oldest evidence on Earth of a dreaded and historic killer - an ancient strain of the bubonic plague.

If indeed the fossil bacteria are related to plague bacteria, Yersinia pestis, the discovery would show that this scourge, which killed more than half the population of Europe in the 14th century, actually had been around for millions of years before that, traveled around much of the world, and predates the human race.