Bonds opened slightly better but are improving in mid morning trading.  Stocks are down.  Investors are responding to a reports that European Central Bank  lending to euro-area banks jumped 214 billion euros ($280 billion) to 879 billion euros in the week ended Dec. 23. The ECB's balance sheet increased 239 billion euros to 2.73 trillion euros, which is 553 billion euros more than three months ago.   The increased borrowing appears to reresent a pro-active defense, rather than a liquidity crisis.  European banks are turning around and "parking" the money back at the ECB. Overnight deposits at the central bank increased to an all-time high of 452 billion euros yesterday.