The Sensex at the Bombay Stock Exchange gained 81 points, or 0.5 per cent, to 17,772 in opening trade, this morning, on sustained buying by funds and retail investors, driven by the government's bid to revive investment. Later, the Sensex gained some more ground, and stood 115 points, or 0.7 per cent in the positive zone, at 17,806 in afternoon deals, a short while ago.Other Asian markets in Japan, Hong Kong, South Korea, Singapore and Taiwan were trading mixed, today. The US Dow Jones Industrial Average had ended flat in yesterday's trade.The rupee lost its initial gains but was still up by 16 paise to 55 rupees 57 paise against the dollar in late morning deals on selling of the American currency by banks and capital inflows from foreign funds into the equity market. The domestic currency rose by 24 paise to trade at 55 rupees 49 paise against the dollar in early trade today. The rupee had edged up by two paise to close at 55.73 against the dollar in the previous lacklustre session on Friday.