Among the stock activity stories for Tuesday, July 24, from AP Business News:
— Shares of Cisco Systems Inc. fell amid concerns about a possible sales slowdown at the computer networking equipment company and a threat from rapidly growing business software maker VMware Inc.
— Shares of Volterra Semiconductor Corp. fell after the company, which makes low-voltage power-management chipsets for computers and networks, reported disappointing earnings amid sluggish sales growth and rising costs.
— Sanmina-SCI Crop.'s stock climbed after the electronics company topped Wall Street revenue expectations for the third-quarter and released healthy fourth-quarter revenue projections as well.

