Brent futures slipped below $112/B on Friday, but they are on course to end a choppy week nearly flat as tensions in the Middle East compete with perennial worries about the global economy and oil demand. Strains in the Middle East escalated this week after Turkey stepped up its strikes against Syria and won parliamentary approval for further military action, pushing Brent prices up 4% on Thursday. That ended a three-day slide for the crude benchmark, when a spate of weak data earlier in the week reinforced concerns that the fragile economic recovery is still under threat with a turnaround in China expected to be delayed and the euro zone almost certainly heading into recession(Reuters). Front-month Brent futures had dropped 62 cents to $111.96/B, while US  crude futures eased 32 cents to $91.39/B, after climbing nearly 4 % in the prior session.