Corteva Inc CTVA.N rose 8.0% after raising its net sales forecast for the year. By Echo Wang Aug 6 (Reuters) - The Dow and the S&P 500 indexes closed at record highs on Friday following a stronger-than-expected jobs report, while investors shrugged off concerns over the Delta variant impacting a nascent economic recovery. Although the three main indexes gained for the week following a stellar corporate earnings season, sentiment has been hurt by fears of higher inflation resulting in a sudden tapering in monetary policy.