The picornavirus, the most common virus in humans, infects over a billion people every year. They cause respiratory and gastrointestinal problems, such as the common cold (mostly associated with a rhinovirus, a particular kind of picornavirus) and diarrhea.

A recent Mayo Clinic study showed that a picornavirus infection can enters the central nervous system (CNS) of some individuals, causing encephalitis and targeting the hippocampus, the portion of the brain responsible for formation of declarative memories, which are facts and experiences that can be consciously called up. Repeated infections may actually be the cause of unattributable memory loss and cognitive impairment in old age.

Since the early 1990s, the planetary status of Pluto has been heavily debated by astronomers seeking to identify the factor(s) that makes a body a planet. In 1992, a Kuiper Belt object designated “(15760) 1992 QB1″ was discovered by astronomers–they realized that it was one of many thousands of trans-Neptunian objects, so-called because they orbit a sun at a greater distance than Neptune. It was at that time that a fierce debate on whether or not Pluto should be classified as a proper planet arose. The coup de grâce came in the middle of 2006 when Eris, a “dwarf planet” discovered in 2005, was measured by the Hubble to be slightly larger than Pluto.

In 2006, the International Astronomical Union, the internationally recognized authority for designation of celestial bodies, dropped Pluto from its list of planets and reduced the total number of planets to 8.