A.H. Belo Corp., the newspaper pure play spun off from Dallas-based Belo Corp., reported its first quarterly result was a loss of $8.7 million, or 43 cents a share, on revenues that tumbled 8.8% to $160.2 million. Advertising revenue, including print and Internet revenue, fell 12% in the quarter compared to a year ago. The chain was particularly hard hit at its major California property, where ad revenue for The Press-Enterprise in Riverside plummeted 26%. A.H. Belo said its newspaper margin -- measured by EBITDA (earnings before interest, taxes, depreciation, and amortization) -- fell by 5 percentage points to 9%....