Put Denise Davis and Lisa Kaufman on the short-timers list. The two top-level aides to House Speaker Joe Straus both plan to leave by the end of the year. Both have been with Straus since shortly after he was elected speaker in January 2009. Davis, a former parliamentarian who also worked in private practice as a lawyer, is his chief of staff; Kaufman, who worked for Sen. Robert Duncan, R-Lubbock, and for the Texas Civil Justice League before joining the speaker, is special counsel.