• Citigroup upgraded shares of Corning (NYSE: GLW) to Buy from Hold as it believes LCD glass production and sales have bottomed and will pick-up in Q2. The firm raised its target price to $16 from $11.25.
  
• Thomas Weisel upgraded Celera (NASDAQ: CRA) to Overweight from Market Weight based on valuation and its strong business model.
  
• ThinkEquity upgraded Varian Semi (NASDAQ: VARI) to Buy from Accumulate and raised its target to $32 from $20 based on valuation and weakness at its sole competitor.
• Sanofi-Aventis (NYSE: SNY) was upgraded to Hold from Underperform at Jefferies.
  
• Agilent (NYSE: A) was raised to Outperform from Neutral at Credit Suisse.
  
• Liberty Interactive (NASDAQ: LINTA) was upgraded at JP Morgan to Neutral from Underweight.

Even though tomorrow is a holiday in the U.S., there are a handful of companies planning to report quarterly earnings nonetheless. Perhaps some may be trying to keep a low profile; others may simply not be concerned with the American holiday schedule. Regardless, here's a quick peek at some of those companies, with the consensus earnings per share estimate of analysts surveyed by Thomson Financial compared to the previous quarter and year-ago quarter, the share price at the close on Friday (with charts behind the links), and consensus recommedations.

• Constellation Energy Partners (NYSE: CEP). Est. EPS: .48; Prev. Q.: .31; Yr-ago: .51; Shares: $19.63; Rec.: Strong buy.
• Flagstone Reinsurance Holdings (NYSE: FSR). Est. EPS: .66; Prev. Q.: .68; Shares: $13.19; Rec.: Hold.
• Natco Group Inc. (NYSE: NTG). Est. EPS: .69; Prev. Q.: .63; Yr-ago: .57; Shares: $44.46; Rec.: Buy.
• PharMerica Corp. (NYSE: PMC). Est. EPS: .08; Prev. Q.: .06; Shares: $13.86; Rec.: Hold.
• Stewart Information Services Corp. (NYSE: STC). Est. EPS: -.04; Prev. Q.: -.79; Yr-ago: .59; Shares: $32.49; Rec.: Hold.
• Trico Marine Services Inc. (NASDAQ: TRMA). Est. EPS: .77; Prev. Q.: .87; Yr-ago: 1.07; Shares: $31.92; Rec.: Buy.

UPDATED: Constellation reported .13 EPS; Flagstone reported .60 EPS; Natco reported .66 EPS; PharMerica reported .09 EPS; Stewart reported -1.74 EPS; and Trico Marine reported 2.08 EPS.