Baryon Stopping in pp and AA at high energies *

Baryon stopping and transport have been investigated both experimentally and theoretically in elementary p+p and heavy ion collisions from AGS to LHC energies. In this talk an overview in particular for data relevant for RHIC and SPS energies will be given. Both published and preliminary data from BRAHMS for p+p and Au+Au collisions will be presented, and comparisons to comparisons to models and centrality dependence will be discussed. Even with these data at fairly high energy and rapidity the lack of data near beam rapidities at higher energies leaves open questions  for complete understanding of baryon transport need to understand initial state conditions in relativistic heavy ion collisions.