Dear PhD Students,

Those who are going to be past their third year next year but would like 
to be considered for an assistantship should please send me their name 
ASAP.  If you have not yet advanced to candidacy, please send me an 
expected timeline to do so.

(Even if you have already expressed interest in a continuing 
assistantship, please reply to this e-mail to reaffirm that interest.)

Thanks,

Steve