The following ratings changes were generated on Thursday, Jan. 8. We've upgraded China Fire & Security Group ( CFSG), which engages in the design, development, manufacture, and sale of fire protection products and services for industrial customers in China, from sell to hold. Strengths include its robust revenue growth, largely solid financial position with reasonable debt levels by most measures and notable return on equity. However, we find that the stock has had a generally disappointing performance in the past year. Revenue is up 44.4% since the same quarter a year ago. The company has no debt to speak of and has a quick ratio of 2.3, demonstrating its ability cover short-term liquidity needs. Net income increased by 47% to $6.4 million, significantly outperforming the S&P 500 and the machinery industry. Shares are down 37.9% year over year, apparently dragged down, in part, by the decline in the S&P 500. But don't assume that it can now be tagged as cheap and attractive. Based on its current price in relation to its earnings, CFSG is still more expensive than most of the other companies in its industry. We've downgraded Celera ( CRA), which delivers personalized disease management through a combination of products and services, from hold to sell, driven its deteriorating net income, disappointing return on equity, decline in the stock price during the past year and feeble growth in its earnings per share. Net income decreased from about $670,000 in the same quarter last year to -$7 million, underperforming the S&P 500 and the biotechnology industry. Return on equity has also greatly , a signal of major weakness within the corporation. Celera's gross profit margin of 71.5% is very high, though it has decreased significantly since the same period last year. Its net profit margin of -15.3% significantly underperformed the industry average.