Researchers have discovered that the genetic malfunction that causes a form of mental retardation called Noonan Syndrome (NS) produces an imbalance in the genesis of two types of cells in the developing embryonic brain. This imbalance, they theorize, could explain how the genetic abnormality gives rise to the neural pathology of the disorder. More broadly, they said, the new insight into the mechanism underlying NS could apply to other inherited forms of retardation.

Marvin Chun of Yale University and colleagues have pinpointed brain regions critical to one of the brain’s more remarkable feats — piecing together a continuous view of the world by integrating snippets of visual input from constantly moving eyes.

Since the eyeball has only a narrow field of clear view, it must continually make tiny shifts to sample the visual world. And during these shifts, which last thousandths of a second, people are essentially blind.

Despite the fact that they both infect the liver, the hepatitis A and hepatitis C viruses actually have very little in common. The two are far apart genetically, are transmitted differently, and produce very different diseases. Hepatitis A spreads through the consumption of fecal particles from an infected person (in pollution-contaminated food or water, for example), but hepatitis C is generally transmitted only by direct contact with infected blood. Hepatitis A produces fever, nausea and abdominal pain that can last for weeks, but rarely lead to death; hepatitis C, by contrast, often spends decades quietly damaging the liver, until a victim’s only hope for survival is an organ transplant.

This device, called HeartLander, can be inserted using minimally invasive keyhole surgery. Once in place, it will attach itself to the heart and begin inching its way across the outside of the organ, injecting drugs or attaching medical devices. In tests on live pigs, the HeartLander has fitted pacemaker leads and injected dye into the heart.

An international research team has found evidence of the Earth's earliest forest trees, dating back 385 million years.

Upright stumps of fossilised trees were uncovered after a flash flood in Gilboa, upstate New York, more than a century ago. However, until now, no-one has known what the entire trees looked like.

New evidence of the brutish and short lives of Stone Age Britons has been revealed by researchers from Cardiff University and the University of Central Lancashire.

Carbon dating of 14 human remains discovered at a prehistoric burial site suggests that most could have died together in a massacre, possibly in a scramble for land or a cattle raid.