  The mean square particle acceleration in high Reynolds number turbulence is
dominated by the mean square pressure gradient. Recent experiments by Voth et
al [Phys. Fluids {\bf 10}, 2268 (1998)] indicate that this quantity, when
normalized by the 1941 Kolmogorov value, ${\epsilon}^{3/2}{\nu}^{-1/2}$, is
independent of Reynolds number at high Reynolds number. This is to be
contrasted with direct numerical simulations of Vedula and Yeung [Phys. Fluids
{\bf 11}, 1208, (1999)] which show a strong increase of the same quantity with
increasing Reynolds number. In this paper we suggest that there is no inherent
conflict between these two results. A large part of the increase seen in DNS is
shown to be associated with finite Reynolds number corrections within the
quasi-Gaussian approximation. The remaining intermittency corrections are
relatively slowly increasing with Reynolds number, and are very sensitive to
subtle cancellations among the longitudinal and transverse contributions to the
mean square pressure gradient. Other possible theoretical subtleties are also
briefly discussed.
