Oil Prices Top \$53 a Barrel, Set Record Oil futures prices advanced to a new high Monday as a strike began in Africa's largest exporter of crude, exacerbating global supply concerns at a time of strong demand and reduced output in the hurricane-ravaged Gulf of Mexico.    Worries about Russian oil supplies also persist as oil giant Yukos, already struggling to repay a multibillion-dollar back-tax bill, got hit Monday with \$1.34 billion in fines...