By DAMIAN J. TROISE and ALEX VEIGA (AP) — U.S. stock indexes are mixed in afternoon trading Tuesday as losses in health care and technology companies keep gains in energy and other sectors of the market in check. The S&P 500 index was up less than 0.1% as of 2:05 p.m. Eastern. Energy companies that stand to benefit from record electricity prices due to the frigid cold impacting much of the country