That increased risk for post-flight disease doubled to 7.7% for passengers seated in a two-seat hot zone.

WSJ: Where Germs Lurk on Planes

South Korea is concentrating on issues which it hopes may be relatively easier for North Korea to accept, such as setting up a hot-line between commanders on both sides of the demilitarised zone, the mutual notification of military exercises, and exchange visits between officers from both sides.

ECONOMIST: The Koreas

The fragments served as signposts for Richard Preston, the best-selling author of the nonfiction book "The Hot Zone, " who was brought in by the Michael Crichton Trust to finish the partially written manuscript.

WSJ: Deciphering Michael Crichton's Clues for 'Micro'

The habitable zone is the region of a planetary system which is neither too hot nor too cold - such that water on the surface of a planet will neither evaporate nor freeze, but instead can stay liquid.

BBC: NEWS | Science/Nature | Earth-like planets may be common

Astronomers call the most promising of these places "Goldilocks planets, " because they orbit in a temperate zone not too hot and not too cold to support liquid water essential for carbon-based life as we know it.

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