Shares in Barclays fell following Tuesday's news of a fall in first quarter profits, but brokers are advising investors to buy the shares on hopes that its turnaround plan will bear fruit.The bank's stock fell 10.5p or 4% to 248p at 10:35 in London after it said a weak investment banking performance caused a 5% fall in quarterly adjusted pre-tax profit to 1.7bn pounds, although retail and credit card operations did well.Barclays is cutting costs and slashing jobs in a shake-up to streamline the bank and has pledged to give more details of its plans on Thursday.Analyst Richard Hunter at broker Hargreaves Lansdown said the shares were likely to be volatile before Thursday's announcement, but added: "If some of the rumoured changes are implemented, resulting in a more streamlined and obviously profitable bank, the recent upgrade of the market consensus to a 'buy' will have been vindicated."Investec also advised investors to buy Barclays, saying it had the cheapest shares of any of its main UK rivals while still offering a best-in-sector prospective 2016 dividend yield of 6.6%.Shore Capital also said the shares were a buy at 259p due to hopes that cost-cutting would boost profits."A convincing strategy update could act as a positive catalyst for share price performance if management can convince the market it can improve returns," the broker said.PW