Here is a list of this morning’s top companies upgrades, downgrades, and initiations by brokerage firms. Upgrades: China Security & Surveillance Tech. (CSR) upgraded to Outperform at Oppenheimer Joy Global (JOYG) upgraded to Buy at Longbow Merck (MRK) upgraded to Buy at Argus Oracle (ORCL) upgraded to Buy at Caris Downgrades: Hornbeck Offshore Services (HOS) downgraded to Neutral at JP Morgan Noble [...]