The U.S. and Chinese manufacturing sectors showed signs of stabilizing in March from earlier slowdowns, while Europe stumbled last month, evidence of an uneven and uncertain global economic outlook. The U.S. Institute for Supply Management said its monthly index of manufacturing activity rose to 55.3 in March from 54.2 the previous month, with new orders particularly buoyant, boding well for U.S. factory output in the coming months. The index is based on whether manufacturing supply managers see activity at their companies…