$F$-stable submodules of top local cohomology modules of Gorenstein   rings
  This paper applies G. Lyubeznik's notion of $F$-finite modules to describe in a very down-to-earth manner certain annihilator submodules of some top local cohomology modules over Gorenstein rings.   As a consequence we obtain an explicit description of the test ideal of Gorenstein rings in terms of ideals in a regular ring. 
Mordechai Katzman