turing machines – A question for mapping reductions

Given a language $ A $ How can you construct a language? $ B $ so that $ A leq_m B $ but $ B not leq_m A $?

I know that when we leave $ B = { langle M, w rangle : | : M text {is an Oracle Turing machine for} A text {and} M text {accepted} w } $, then $ A leq_T B $ but $ B not leq_T A $But is there a simple construction for mapping reductions that does not involve oracles?