Cookson, the FTSE 250 materials science firm, was a top riser after it reported a rise in revenue, margins and pre-tax profit in the year ended December 31st, despite increasing raw materials prices.Revenue rose 11% at reported rates (9% at constant currency rates) from £2,546m to £2,826m, which the group says is partly down to the passing through of significantly higher metals prices for tin, silver and gold. Meanwhile, house-builder Bovis fell despite posting a 74% increase in annual pre-tax profit after it sold more homes at a wider margin. Profit before tax rose to £32.1m for the financial year ended 31 December 2011 from £18.5m the year before. Revenue for the year increased to £364.8m from £298.6m previously. It was a similar story for engineering firm Senior, which reported a rise in both revenues and pre-tax profit for the year ended December 31st. The firm saw a 40% leap in profit before tax from £52.1m to £72.7m, on revenues which rose 13% from £566.9m to $640.7m. Shares were down 3%.FTSE 250 - RisersRank Group (RNK) 144.80p +4.47%Carpetright (CPR) 699.50p +3.94%Perform Group (PER) 279.80p +3.63%Cookson Group (CKSN) 691.50p +3.13%Spirit Pub Company (SPRT) 56.75p +2.25%Berendsen (BRSN) 508.50p +1.70%Home Retail Group (HOME) 104.70p +1.36%Moneysupermarket.com Group (MONY) 121.10p +1.34%Halfords Group (HFD) 320.60p +1.17%F&C Asset Management (FCAM) 71.30p +1.13%FTSE 250 - FallersLaird (LRD) 166.60p -4.75%Bovis Homes Group (BVS) 486.60p -3.74%Big Yellow Group (BYG) 289.70p -3.53%JPMorgan Indian Inv Trust (JII) 379.00p -3.41%Logica (LOG) 85.70p -3.38%Afren (AFR) 141.20p -3.29%Oxford Instruments (OXIG) 1,132.00p -3.25%Senior (SNR) 194.50p -3.23%Domino Printing Sciences (DNO) 648.50p -3.21%Kenmare Resources (KMR) 58.35p -2.99%