Stocks were lower in early-afternoon action Tuesday. Even blue chips weakened after trying to hang tough. The Nasdaq dropped 0.6%, hurt by Internet issues Baidu (BIDU) and Google (GOOG). Heavyweight Apple (AAPL) was also lower. Meanwhile, the S&P 500 lost 0.4%. The Dow Jones industrial average, which had held above the flat line earlier, fell 0.2%. Turnover continued to track lower across the board. Mellanox Technologies (MLNX) came under pressure