Tate & Lyle is up more than 10% after the sugar firm appointed Javid Ahmed, currently executive vice president at detergent group Reckitt Benckiser, as chief executive.Oil and gas firm Melrose Resources rises after raising its production forecast for 2009 by around 5%But Dana Petroleum falls back after the oil explorer announced a placing representing 5% of its existing share capital to fund increased exploration activities.Xchanging, the business processing outsourcing company, is out of favour after it said 2009 revenues are running slightly below expectations.Talk of green shoots is largely passing Spectris by, as the instrumentation and controls group said full-year profits would be at the bottom end of analysts' expectations.Investors seem to be focusing on the negatives from Regus's trading update. The office provider reported a 16% rise in revenues during the four months to April 30 as it increased its international presence, but said that yields remain under pressure amid tough conditions.FTSE 250 - RisersCookson Group (CKSN) 245.00p +10.61%Tate & Lyle (TATE) 301.50p +10.24%GKN (GKN) 137.75p +9.98%Rightmove (RMV) 347.00p +8.61%Melrose (MRO) 107.50p +8.59%Computacenter (CCC) 199.00p +8.45%Travis Perkins (TPK) 766.50p +7.58%Enterprise Inns (ETI) 153.75p +7.33%Talvivaara Mining Company (TALV) 296.25p +6.85%Salamander Energy (SMDR) 181.50p +6.30%FTSE 250 - FallersXchanging (XCH) 182.50p -11.41%Spectris (SXS) 535.50p -8.46%Regus (RGU) 77.25p -8.04%Kesa Electricals (KESA) 120.00p -3.23%JPMorgan Indian Inv Trust (JII) 320.00p -2.81%HMV Group (HMV) 133.25p -2.38%Euromoney Institutional Investor (ERM) 239.50p -2.24%Dunedin Income Growth Inv Trust (DIG) 155.25p -1.90%Eaga (EAGA) 118.25p -1.66%Dana Petroleum (DNX) 1,297.00p -1.59%