The Questor column in The Telegraph has rated cruise operator Carnival as a 'sell' on the back of concerns about the spread of Ebola which have sparked a recent sell-off across the travel sector.The Ebola fears "could not come at a worse time" for Carnival, the paper's John Ficenec writes. Up until the Ebola fears had escalated, things were improving for the cruise operator - full-year guidance was recently upgraded while falling fuel costs had given an additional boost.To round things off, he said that the stock is not cheap, with shares trading at 21 times forecast earnings.Petroceltic shareholders are advised to "sit tight and keep a close eye on developments", says Joanne Hart from Midas in the Mail on Sunday, after the oil and gas group last week received a near-£500m takeover bid from Dragon Oil, equal to 230p a share.Midas tipped the shares in March 2009 at the equivalent of 100p, but recent moves have taken them to 215.25p. The paper says that Petroceltic's board is minded to recommend the offer, but some brokers are hoping for a more generous offer of 250p a share.Either way, shareholders "are in a pretty good place", Midas says.The recent plunge across global equity markets threatens to "derail" the turnaround at Brewin Dolphin, according to The Telegraph's Questor column, which recommended investors to 'sell' shares of the wealth manager.The paper said that the sharp sell-off across stock markets over the last two weeks will be "painful" for the company as the value of its assets naturally shrinks in line with prices. Meanwhile, clients could become "spooked" by market falls and withdraw funds, it said.Questor, which has seen the stock drop 13% since it recommended the shares in December 2013, said: "The turnaround has hit a tricky period and we are cutting our losses."WYG is a strong 'hold' for existing shareholders and a potential 'buy' for new investors, Midas in the Mail on Sunday says, with the business consultancy group "firing on all cylinders".The stock has risen from 62.5p in December 2012 - when Midas recommended the shares - and now stand at 111p but with the potential for further gains, with profitability at the company set to soar. Boss Paul Hamer said last week that WYG is targeting pre-tax profits of £15m by the year to March 2018, up from just £4.2m last year, as the company wins larger and longer contracts."The company is making strides here and abroad and the outlook is promising," Hart said.