Donald Trump demands a do-over in Iowa
  1. Sore loser
    Donald Trump accuses rival Ted Cruz of stealing his victory in the Republican Iowa caucuses.
  2. Kamikaze mosquitoes
    Researchers hope a genetically engineered mosquito can turn the Zika-spreading bugs into weapons against the virus.
  3. Assault on Aleppo
    Syrian forces loyal to President Bashar al-Assad, backed by Russian airstrikes, are close to cutting off a key rebel stronghold.
  4. From clicks to bricks
    After helping eliminate brick-and-mortar retailers, Amazon now could be planning to open up to 400 real-life bookstores.
  5. Ground control to Kim Jong Un
    North Korea alarmed its neighbors with the news that it plans to launch a satellite into orbit, which may be cover for a long-range rocket test.