In an exhaustive review of all studies published through June 2012, "it has become clear there is no easy way to grade a concussion and no set timeline for a return to play" says Christopher C.

WSJ: Tougher Rules Advised for Athletes After Concussion

This is also where many institutional investors have focused their attention, because the emerging market sovereign bonds are closer substitutes for investment grade bonds here in the US. As the Fed has crowded people out of the US investment grade space, they have moved to emerging market sovereign bonds as an easy substitute.

FORBES: 5 Ways to Increase Profits From an Emerging Markets Bond Pro