Today's noteworthy upgrades include: Artisan Partners (APAM) upgraded to Neutral from Underperform at BofA/Merrill... Assured Guaranty (AGO) upgraded to Buy from Neutral at BTIG... Brunswick (BC) upgraded to Outperform from Sector Perform at RBC Capital... CarMax (KMX) upgraded to Buy from Neutral at Goldman... Centene (CNC) upgraded on Health Net accretion at Wells Fargo... Dick's Sporting (DKS) upgraded to Outperform from In-Line at Imperial Capital... EXCO Resources (XCO) upgraded to Sector Perform from Underperform at RBC Capital... Exelon (EXC) upgraded to Neutral from Underperform at BofA/Merrill... Fuel Systems (FSYS) upgraded to Buy from Hold at Craig-Hallum... Infineon (IFNNY) upgraded to Outperform from Market Perform at Bernstein... Inventure Foods (SNAK) upgraded to Outperform from Neutral at Wedbush... LVMH (LVMUY) upgraded to Buy from Hold at Deutsche Bank... Melco Crown (MPEL) upgraded to Neutral from Underperform at BofA/Merrill... Publicis (PUBGY) upgraded to Buy from Neutral at Goldman... St. Jude Medical (STJ) upgraded to Outperform from Market Perform at Wells Fargo... Tetra Tech (TTEK) upgraded to Outperform from Neutral at Wedbush... Validus (VR) upgraded to Neutral from Sell at Goldman... W. R. Berkley (WRB) upgraded to Buy from Neutral at Goldman.