NEW YORK ( TheStreet) -TheStreet Ratings' stock model upgraded Cephalon ( CEPH) to 'Buy' from 'Hold'. Net income at this $4.8 billion market cap, biopharmaceutical company grew 5.1% to $89 million in second quarter over the prior second quarter. TheStreet Ratings released rating changes on eight additional U.S. common stocks for September 24, 2010. In total, just one stock was downgraded and eight stocks have been upgraded by our stock model. Second quarter revenue at Cephalon grew by 32.7% to $727 million over the same quarter last year. Learn more about Cephalon: Company Profile, Income Statement, Balance Sheet, Stock Ratios, Analyst Ratings. In another upgrade, shares of RBC Bearings Inc ( ROLL) have moved to 'Buy' from 'Hold'. Fiscal first quarter net income increased by 79% to $9.1 million while revenue advanced by 29% to $82 million from the year earlier quarter. Learn more about RBC Bearings: Company Profile, Income Statement, Balance Sheet, Stock Ratios, Analyst Ratings. -- Reported by Kevin Baker in Jupiter, Fla. For additional Investment Research check out our Ratings Research Center.