Developments in the Eurozone were supporting stocks on Thursday morning as markets rebounded to snap a four-day losing streak.However, the focus is likely to turn to the US later on as first-quarter earnings season continues to dictate sentiment. Wall Street benchmarks slumped last night after some disappointing results from a number of heavyweights, including Bank of America, Intel and Yahoo. US jobless claims are also on tap later on.This side of the Pond, Spain managed to sell more long-term debt than its target and saw lower yields at a medium- to long-term bond auction this morning. The Treasury offloaded €4.714bn in debt, ahead of its €3.5-4-5bn forecast.Meanwhile, Portugal has approved new measures to cut spending in order to comply with its bailout agreement following the Constitutional Court rejection last week. The government managed to put through new initiatives designed to reduce spending by 0.5% of gross domestic product (GDP) or approximately €800m. The STOXX Europe 600 Index was making decent gains this morning, following its largest four-day slump since July 2012.Concerns over the global economy have hit markets over the past week following disappointing growth figures from China and downwards revisions to worldwide GDP forecasts from the International Monetary Fund.Theres fears were compounded yesterday after Jens Weidmann, the head of Germany's Bundesbank, told The Wall Street Journal that the recovery in Europe could take as long as a decade to overcome.However, he did leave the door open to the possibility that the European Central Bank would cut rates if required, but warned that such a move would be unlikely to turn the Eurozone's dire economy around and urged government authorities to take action. FTSE 100: Glaxo gains on FDA approvalShares in pharmaceuticals giant GlaxoSmithKline gained this morning after the the US FDA approved Breo Ellipta, a treatment for chronic obstructive pulmonary disease (COPD). "This positive recommendation is a crucial first step towards making Breo Ellipta available for appropriate COPD patients across the US."Engineering firm GKN was in demand after saying that it acquisition of Volvo Aero last year helped boost sales by 9.0% in the first quarter of 2013.Tullow Oil was also high riser after Societe Generale upgraded the stock from 'hold' to 'buy', saying that recent investor uncertainty over its exploration-led strategy has created a buying opportunity.Consumer packaging firm Rexam was higher after reporting that overall results were in line with forecasts in the first quarter despite slower-than-expected volume growth.Precious metals group Fresnillo advanced after saying that it will review all expenditure and exploration projects after the recent sharp falls in gold and silver prices. The company said that silver production had increased in the first quarter, but gold production fell. Heading the other way was mining giant ENRC which slumped on the back of reports that the Serious Fraud Office is looking into corporate governance issues at the firm.Drinks giant SABMiller edged higher reporting a 3.0% increase in organic lager volumes in the year to March 31st. Sector peer Diageo failed to impress after saying it remained on track to hit full-year targets following a robust third quarter.DIY retailer Kingfisher was subdued after saying that it has acquired 15 'Brincostore' retail outlets in Romania from a French retail company for an undisclosed sum.Engineering giant Weir Group fell after revealing that it is expanding its presence in the mining and minerals markets through a number of agreements for crushing, grinding and screening equipment and services.FTSE 100 - RisersGlaxoSmithKline (GSK) 1,674.50p +4.20%GKN (GKN) 253.70p +3.26%Carnival (CCL) 2,334.00p +2.82%Tullow Oil (TLW) 1,010.00p +2.80%Shire Plc (SHP) 1,963.00p +2.08%Melrose Industries (MRO) 245.50p +1.82%G4S (GFS) 301.20p +1.79%Rexam (REX) 515.00p +1.78%Petrofac Ltd. (PFC) 1,300.00p +1.72%Prudential (PRU) 1,036.00p +1.67%FTSE 100 - FallersEurasian Natural Resources Corp. (ENRC) 219.60p -8.58%Antofagasta (ANTO) 861.00p -4.97%Randgold Resources Ltd. (RRS) 4,499.00p -1.47%Compass Group (CPG) 815.50p -1.45%Polymetal International (POLY) 696.50p -1.35%Resolution Ltd. (RSL) 251.30p -1.10%Royal Bank of Scotland Group (RBS) 280.30p -1.02%BHP Billiton (BLT) 1,762.50p -0.93%Centrica (CNA) 379.60p -0.89%ITV (ITV) 123.40p -0.88%FTSE 250 - RisersDebenhams (DEB) 87.25p +8.39%National Express Group (NEX) 197.20p +3.25%Synergy Health (SYR) 1,044.00p +3.16%Filtrona PLC (FLTR) 721.00p +3.15%SVG Capital (SVI) 379.70p +2.96%COLT Group SA (COLT) 125.80p +2.69%Daejan Holdings (DJAN) 3,700.00p +2.49%Anite (AIE) 115.70p +2.39%Domino Printing Sciences (DNO) 656.50p +2.34%Heritage Oil (HOIL) 175.80p +2.27%FTSE 250 - FallersNew World Resources A Shares (NWR) 170.00p -9.09%Kazakhmys (KAZ) 305.00p -4.72%Devro (DVO) 322.70p -3.84%CSR (CSR) 473.40p -3.13%African Barrick Gold (ABG) 165.00p -3.11%Ladbrokes (LAD) 184.20p -2.54%EnQuest (ENQ) 121.70p -2.25%Kenmare Resources (KMR) 26.34p -1.53%Direct Line Insurance Group (DLG) 201.70p -1.51%Ophir Energy (OPHR) 381.80p -1.45%BC