Tyson Foods Inc TSN.N fell 3.4% on missing quarterly profit expectations. By Bansari Mayur Kamdar and Aniruddha Ghosh Aug 8 (Reuters) - U.S. stock indexes were set to open higher on Monday after last week's blockbuster jobs data soothed some fears about an economic slowdown, but investors remained cautious as it also added to expectations of a hawkish Federal Reserve. The S&P 500 has bounced back 13% from its mid-June lows, but investors fear that signs of persistent inflation this week could further bolster the Fed's case for aggressive monetary policy tightening.