Boston Federal Reserve Bank President Cathy Minehan saidThursday the Fed needs to stay "vigilant" against "downside risks"but said she is "cautiously optimistic" about the economic outlook.In particular, Minehan was upbeat about consumer spending inremarks prepared for delivery to the New England Pension Consultants' annual meeting. And she expressed optimism aboutbusiness inventory adjustment and investment. The economy islikely to rebound in the second half, yielding 2% average growth forthe whole year, Minehan said.