Polymer products maker Fenner slumped after warning that underlying group profit before tax for the current fiscal year could be reduced by as much as 10-15% below the current consensus market expectation of £77.6m. This was partly due to what are expected to be "significantly weaker" than previously anticipated results from its ECS business in the US for the remainder of the financial year ending August 31st. The group previously predicted an improvement towards the year-end. It explained both trading conditions and sentiment in the US coal industry had deteriorated and are showing no prospects for imminent improvement.The news prompted Numis Securities to downgrade its rating on the stock from 'add' to 'hold'.Tate & Lyle was also in the red after Credit Suisse cut its target price on the sugars and sweeteners group from 700p to 650p and downgraded it from 'neutral' to 'underperform'. It yesterday moved higher after it produced annual revenues, profits and earnings broadly in line with expectations, despite facing tough competition in artificial sweeteners and adverse weather effects.Miners were providing a drag, as iron ore prices were headed for their sixth consecutive monthly decline, the longest losing streak on record. They were also hit by concerns about a slowdown in China which was also having an impact on stocks. Evraz and Vedanta were both in the bottom 10 this afternoon. Meanwhile, Unite, which builds and manages student accommodation in the UK, rose on the news it is to buy and redevelop a site in Portsmouth to create 830 new beds for those studying in the city.The company said that the 0.77-acre site, subject to planning permissions, "will help address the shortage of purpose built student accommodation in the city".FTSE 250 - RisersOphir Energy (OPHR) 267.80p +4.53%CSR (CSR) 599.50p +3.90%Rank Group (RNK) 162.00p +3.85%Euromoney Institutional Investor (ERM) 1,181.00p +3.78%Ocado Group (OCDO) 386.30p +3.70%Afren (AFR) 154.90p +3.68%Micro Focus International (MCRO) 841.50p +3.38%Supergroup (SGP) 1,145.00p +3.25%Spirent Communications (SPT) 105.50p +3.23%Dairy Crest Group (DCG) 463.90p +3.09%FTSE 250 - FallersFenner (FENR) 348.40p -10.60%Paragon Group Of Companies (PAG) 374.10p -3.78%Evraz (EVR) 106.00p -2.93%Serco Group (SRP) 359.00p -1.91%Drax Group (DRX) 625.00p -1.81%Vedanta Resources (VED) 1,108.00p -1.69%Tate & Lyle (TATE) 691.00p -1.50%Booker Group (BOK) 140.90p -1.40%Ferrexpo (FXPO) 137.10p -1.37%Homeserve (HSV) 337.50p -1.32%NR