yes
Mark J. Ablowitz was born in 1945.
James J. Andrews - mathematician - died in 1998.
James J. Andrews - mathematician - was born in 1930.
Homi J Bhabha was a nuclear physicist, who studied mathematics during his education. This could mean that he was a mathematician, yes.
Mark J. Alexander died in 2004.
Mark J. Alexander was born in 1911.
Mark J. Kilroy died in 1989.
Mark J. Hudson was born in 1963.
Mark J. Blechner was born in 1950.
J. Mark Wilcox was born in 1890.
J. Mark Wilcox died in 1956.
Mark J. Lewis was born in 1962.