Russian gold miner Petropavlovsk surged after maintaining its production targets for the full year and reported progress in its exploration work. Attributable production across its five mines for the second quarter was 158,300 ounces, a 10 per cent rise on the same period of 2011. Precision tool maker Renishaw jumped after posting a 7% increase in annual pre-tax profit, boosted by strong demand across all its markets for its precision measuring products. Shares in Drax, which converts coal and biomass to energy, plunged after the government announced that it has decided to create support levels for electricity generated from sustainable biomass at existing fossil fuelled power stations on an individual generating unit by unit basis, and not, as previously proposed, on a power station wide basis. FTSE 250 - RisersRenishaw (RSW) 1,459.00p +14.88%Man Group (EMG) 77.85p +8.12%Ocado Group (OCDO) 76.70p +6.97%Petropavlovsk (POG) 404.40p +6.17%Senior (SNR) 189.50p +4.12%CSR (CSR) 307.90p +3.95%Bodycote (BOY) 334.70p +3.75%Rank Group (RNK) 120.00p +3.45%FirstGroup (FGP) 212.00p +3.21%Spirent Communications (SPT) 157.50p +3.14%FTSE 250 - FallersDrax Group (DRX) 439.80p -15.18%Cookson Group (CKSN) 523.50p -12.16%Euromoney Institutional Investor (ERM) 746.00p -5.51%Informa (INF) 349.60p -5.49%COLT Group SA (COLT) 105.20p -4.80%Atkins (WS) (ATK) 722.00p -3.86%Bwin.party Digital Entertainment (BPTY) 108.10p -3.83%Genus (GNS) 1,294.00p -3.22%Savills (SVS) 362.70p -2.84%Galliford Try (GFRD) 605.50p -2.73%NR