Analyst upgrades, downgrades and initiations: SNDK, POT, BK, ASIA ...

Analyst upgrades:

Thomas Weisel upgraded SanDisk (NASDAQ: SNDK) to Overweight from Market Weight due to accelerating manufacturing cost declines, potential NAND flash sourcing upside at Toshiba (OTC: TOSBF) and Samsung and an increase in 2H09 demand.
Oppenheimer upgraded Quality Systems (NASDAQ: QSII) to Perform from Underperform to reflect potential benefits from the stimulus package and channel checks that indicated IT budgets are stabilizing. The firm raised its target price on shares to $54 from $40.
RBC Capital upgraded OSI Pharmaceuticals (NASDAQ: OSIP) to Outperform from Sector Perform following positive Tarceva survey results and cites valuation.
Marriott (NYSE: MAR) was upgraded to Outperform from Market Perform at JMP Securities.
Grainger (NYSE: GWW) was upgraded to Buy from Neutral at BofA/Merrill.
Duncan Energy Partners (NASDAQ: DEP) was upgraded to Buy from Neutral at UBS.

Analyst downgrades:

UBS downgraded Human Genome (NASDAQ: HGSI) to Neutral from Buy and lowered its target to $2.75 from $3. The firm based the downgrade on valuation and downside risk to BLISS-52 data expected later this month.
Oppenheimer downgraded Intrepid Potash (NYSE: IPI) to Underperform from Outperform and Compass Minerals (NYSE: CMP) to Perform from Outperform since the firm thinks that potash prices will drop rapidly after a Russian company sold the fertilizer to India at "disappointing" prices.
Credit Suisse downgraded Capella Education (NYSE: CPLA) to Neutral from Outperform. The firm, which has a $61 target on the stock, cites valuation for the downgrade.
Bank of New York Mellon (NYSE: BK) was downgraded to Buy from Conviction Buy at Goldman.
Kayne Anderson (NYSE: KED) was downgraded to Neutral from Buy at UBS.

Analyst initiations:

Citigroup initiated Navios Maritime (NYSE: NMM) with a Hold rating and $8.50 target. The firm believes weak volumes and rate re-negotiations could limit upside in shares, but believes Navios Maritime is well positioned in dry bulk.
Leerink started Thoratec (NASDAQ: THOR) with an Outperform rating and believes the second generation launch of HeartMate II will drive growth in 2010 and beyond. The firm has a target range on shares of $33-$37.
Susquehanna views AsiaInfo (NYSE: ASIA) as an attractive opportunity to invest in Chinese telecom infrastructure and mobile applications. Shares were assumed with a Positive rating and $20 target.
CenturyTel (NYSE: CTL) was initiated with a Buy rating and $35 target at BofA/Merrill.
Natus Medical (NASDAQ: BABY) was initiated with a Neutral rating at Cowen.
Everest RE Group (NYSE: RE) was initiated with a Buy rating at UBS.