Invasive bacterial pathogens, the Chlamydiae know us very, very well. The Chlamydiae learned to parasitize eukaryotic cells half a billion years ago by reprogramming cellular functions from within. In humans today, chlamydial infections are responsible for a range of ailments from sexually transmitted infections to atypical pneumonias to chronic severe disorders such as pelvic inflammatory disease and atherosclerosis. The Centers for Disease Control says that Chlamydia trachomatis is the most common sexually-transmitted infection in the US, with three million new cases a year.

Looking through his handmade microscope in 1702, it was Anton van Leeuwenhoek who first described the workings of a nano machine. He observed the rapid contraction of a stalk tethering the cell body of a tiny protozoan, Vorticella convallaria, to the surface of a leaf. Little did van Leeuwenhoek imagine that more than 300 years later, the biological spring that drives Vorticella would set records for speed and power in the nano world of cellular engines.

US data on influenza death may be more PR than science, argues a Harvard University graduate student in this week's British Medical Journal.

The six-legged fruitfly appears to have little in common with humans, but a new finding shows that they are really just tiny, distant cousins. Scientists at the Carnegie Institution’s Department of Embryology have found that adult fruitflies have the same stem cells controlling cell regulation in their gut as humans do.