Analyst Upgrades

• Amgen (AMGN) to overweight from neutral at Piper Jaffray.
• Goodrich Petroleum (GDP) to outperform from market perform at Wells Fargo.
• Tutor Perini (TPC) to buy from neutral at UBS.
• Covidien (COV) to buy from neutral at Goldman.
• Sara Lee (SLE) and Comcast (CMCSA) to outperform from market perform at Bernstein.
• Research In Motion (RIMM) to outperform from sector perform at FBN Securities.

Analyst Upgrades

• JPMorgan upgraded Dollar Tree (DLTR) to neutral from underweight and $48 price target.
• Credit Suisse upgraded Time Warner Cable (TWC) to outperform from neutral and raised its price target to $70 from $59, citing growth in wireline HST demand.
• Needham upgraded NetScout (NTCT) to buy from hold with a $29 price target, citing channel checks that indicate industry spending on network monitoring software may be improving.
• Nstar (NST) was upgraded to buy from neutral at BofA/Merrill.
• Novo Nordisk (NVO) was upgraded to hold from sell at Societe Generale.
• Air France-KLM (AFLYY) was upgraded to neutral from underperform at Credit Suisse.

Here are some highlights from this past week's earnings coverage on BloggingStocks:

• Coinstar Inc. (CSTR) shares surged following stronger-than-expected Q1 earnings driven by DVD rentals.
• Humana Inc. (HUM) shares traded lower despite the report of better-than-expected earnings for Q1.
• IMAX Corp. (IMAX) reported strong Q1 results that easily topped consensus estimates, but shares declined.
• Kellogg Co. (K) topped Q1 earnings expectations and announced a share buyback program.
• Office Depot Inc. (ODP) Q1 earnings fell short of consensus estimates and same-store sales declined.