Corteva Inc CTVA.N rose 6.4% after raising its net sales forecast for the year. By Shreyashi Sanyal Aug 6 (Reuters) - The Dow and the S&P 500 scaled record highs on Friday as shares in economy-linked sectors jumped following a solid rise in jobs in July, helping allay fears of the Delta variant impacting a nascent economic recovery. Although the three main indexes are set to end the week with nominal gains following a stellar corporate earnings season, fears of higher inflation resulting in a sudden tapering in monetary policy have hurt sentiment.