Less experienced prostitutes are more likely to have sexually transmitted infections (STIs). A study of more than a thousand female sex workers in Cambodia, reported in the open access journal BMC Infectious Diseases, has shown that girls who were new to the sex industry were twice as likely to have gonorrhoea or chlamydia.

Not 10 years ago, most doctors agreed that estrogen supplements for post-menopausal women reduced the risk of heart attacks. Millions were paying extravagantly for “hormone replacement therapy”, and drug companies were making a killing. However, a comprehensive study conducted by the Women’s Health Initiative was stopped early, in 2002, because the dangers to healthy women taking estrogen were deemed excessive. Estrogen therapy, it turned out, actually increased the risk of heart attack, strokes, and breast cancer. The medical community was shocked. The Annals of Internal Medicine ran an editorial “How Could We Have Been So Wrong?” The National Institutes of Health hosted a special seminar on “methodology” and “medical evidence”.

Throughout history, human beings have used the whistle for everything from hailing a cab to carrying a tune. Now, an orangutan's spontaneous whistling is providing scientists at Great Ape Trust of Iowa new insights into the evolution of speech and learning. 

Insufficient vitamin D can stunt growth and foster weight gain during puberty, according to a new study published in the Journal of Clinical Endocrinology&Metabolism. Even in sun-drenched California, where scientists from the McGill University Health Centre (MUHC) and the University of Southern California conducted their study, vitamin D deficiency was found to cause higher body mass and shorter stature in girls at the peak of their growing spurt.

Moons outside our Solar System with the potential to support life have just become much easier to detect, thanks to research by an astronomer at University College London (UCL).

David Kipping has found that such moons can be revealed by looking at wobbles in the velocity of the planets they orbit. His calculations, which appear in the Monthly Notices of the Royal Astronomical Society today, not only allow us to confirm if a planet has a satellite but to calculate its mass and distance from its host planet ­ factors that determine the likely habitabiliity of a moon.

A new study from the psychology department at Tufts University shows that when dieters eliminate carbohydrates from their meals, they performed more poorly on memory-based tasks than when they reduce calories, but maintain carbohydrates. When carbohydrates were reintroduced, cognition skills returned to normal.

While the brain uses glucose as its primary fuel, it has no way of storing it. Rather, the body breaks down carbohydrates into glucose, which is carried to the brain through the blood stream and used immediately by nerve cells for energy. Reduced carbohydrate intake should thus reduce the brain's source of energy. Therefore, researchers hypothesized that diets low in carbohydrates would affect cognitive skills.

Airline pilots who have flown for many years may be at risk of DNA damage from prolonged exposure to cosmic ionizing radiation, suggests a study in Occupational and Environmental Medicine.

The research team compared the rate of chromosomal (DNA) abnormalities in blood samples taken from 83 airline pilots and 50 university faculty members from the same US city.

The two groups were matched for age (35 to 56), sex (male), and smoking habit (light or non-smokers). Age and smoking are known risk factors for cumulative DNA damage.

Fifty eight of the pilots (70%) had served in the military, and they had undertaken significantly more personal air travel than the university staff. Both these factors would have exposed them to more ionising radiation.