2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/12962I review particle heating by MHD turbulence in collisionless plasmas appropriate to advection-dominated accretion flows. These considerations suggest that the preferential turbulent heating of protons assumed by theoretical models is only achieved for relatively subthermal magnetic fields.6 pages, uses paspconf.sty, to appear in Proc. of ``The Workshop on High Energy Processes in Accreting Black Holes,'' eds. J. Poutanen & R. SvenssonAstrophysicstext