TSC Ratings provides exclusive stock, ETF and mutual fund recommendations using proprietary tools. Our "safety-first" approach aims to reduce risk while achieving performance on a total return basis.The following five mid-cap companies have market values of $500 million to $10 billion, and receive "buy" recommendations from TheStreet.com Ratings' proprietary quantitative model, which considers more than 60 factors. The stocks are ordered by their potential to appreciate. Landauer ( LDR) offers personnel radiation monitoring to measure the dosage of X-rays, gamma radiation and other penetrating ionizing radiation to which a person has been exposed. The numbers: Fiscal second-quarter revenue increased 5% to $25 million as net income and earnings per share fell 16% to $5.4 million and 58 cents, respectively. Operating margin declined 14 basis points to 42% and net margin fell 532 basis points to 22%. The company has no debt or interest expenses, and a quick ratio of 1.9 indicates ample liquidity. The stock: Landauer has fallen 18% in 2009, underperforming the Dow Jones Industrial Average and the S&P 500. The stock offers a 3.5% dividend yield and trades at a price-to-earnings ratio of about 25. Strayer Education ( STRA) is a for-profit post-secondary education company that offers a variety of academic programs through Strayer University. The numbers: Fiscal first-quarter revenue increased 28% to $125 million as net income jumped 24% to $29 million and earnings per share improved 26% to $2.07. Operating margin improved 162 basis points to 38% as net margin fell 89 basis points to 23%. Strayer has no debt and a quick ratio of 1.5, indicating an ideal financial position. The stock: Strayer has fallen 6% in 2009, outperforming the Dow and underperforming the S&P 500. The stock is trading at a price-to-earnings ratio of 33. A 1% dividend yield sweetens the stock, but is below the S&P 500 average.