UK markets are expected to open with small gains on Tuesday following a decent performance by US and Asian stocks overnight as investors ready themselves for comments from new Federal Reserve Chair Janet Yellen. City sources predict the FTSE 100 will open 27 points higher than yesterday's close of 6,591.55.After a subdued session on Monday in the absence of any major corporate earnings or economic data, things are set to pick up today with a raft of heavyweights having already reported results, including Barclays, Glencore Xstrata and Babcock.Meanwhile, figures showed this morning that like-for-like UK retail sales rose by 3.9% in January compared with the year before, according to the British Retail Consortium/KPMG sales monitor. This was much higher than the 0.4% growth registered in December and the 0.8% increase expected by analysts.Markets across the globe are likely to focus on Yellen's testimony to the House Financial Services Committee later this afternoon, with investors eager to gauge her thoughts on the Fed's staged withdrawal of stimulus after she took over from former central bank head Ben Bernanke this month.Given that there is still six weeks to go before the Fed's next meeting - during which there will be a lot of upcoming economic data - Yellen is likely to "reinforce comments made by other Fed officials recently that there is a high bar to pulling back from tapering," said Chief Market Analyst Michael Hewson from CMC Markets."We could also find out whether the recent turmoil in emerging markets came up for discussion in the deliberations surrounding the recent decision to taper further," he said.Stocks to watchBarclays reported a 32% fall in 2013 adjusted pre-tax profit of £5.16bn reflecting a fall in income and costs of restructuring. The company incurred £49m of costs to achieve its so-called Transform strategy in revamping the lender. Adjusted income fell 4% to £28.15bn due to a reduction of £1.04bn in the Investment Bank and £480m in the Head Office.Commodities trader and mining giant Glencore Xstrata increased production of most of its major commodity classes in 2013.The firm, which was formed through the merger of Glencore and Xstrata in May 2013, said that total own sourced copper output rose 26% to 1.5m tonnes last year, driven by strong growth in Africa and its Collahuasi joint venture with Anglo American in Chile.Babcock International said it continues to experience positive market conditions across its business units in the UK and overseas and is confident of further strong progress this year, in line with its expectations. The engineering support services company saw high activity levels in all divisions during the third quarter, helped by the improving economic climate.Vodafone has partnered up with money transfer and payment services company MoneyGram to launch a service that will enable consumers to transfer funds directly from around 200 countries to users of its M-Pesa service. The service will be launched in key markets during the second quarter of 2014, with additional roll-out planned throughout the remainder of the year.Tour operator Thomas Cook unveiled lower quarterly losses but also posted a fall in revenue as holidaymakers avoided political turmoil in Egypt.Analysts at Morgan Stanley have downgraded their recommendation on the shares of BG Group to 'equalweight' from overweight'. Goldman Sachs has upgraded its view on ICAP to 'neutral' from 'sell'. BC