A revival of nuclear fall-out fears in Tokyo has put a cap on optimism at the start of the trading week in London and shares are expected to open mixed, with the FTSE 100 tipped to open aroun 5 points up from its previous close of 5,901.Tullow Oil has found oil at the Teak-2 exploration well in the West Cape Three Points licence offshore Ghana. The Irish oil company, which has a 23% stake in the licence, discovered 27 metres of net hydrocarbon bearing Campanian and Turonian reservoirs at the well, drilled between the Jubilee field and Teak-1 discovery.A 13-year tax wrangle between the US and the UK involving drugs giant AstraZeneca has been resolved, resulting in a substantially lower tax rate for Astra in the current financial year. As a consequence, Astra has lifted its core earnings per share guidance for fiscal 2011 to $6.90 - $7.20 from $6.45 - $6.75 previously.Irn-Bru and Tizer maker AG Barr saw profit on ordinary activities before tax and exceptional items increase by 13.3% to £31.6m in the 12 months to 29 January from £27.9m the year before. The company saw strong growth from all core brands in all channels.Growth in its business to business titles helped lift Daily Mail Group's underlying revenues by 5% over the past five months, though it was another tough period for regional paper arm Northcliffe.- - - jh