Ajay Kurian’s “Proleptic” (as in prolepsis, or anticipation) takes as its subject the “long durée of nuclear waste,” examining the bizarre symbols and signage designed to warn future people to stay away from toxic sites. On view are a number of sculptures of assembled objects in colored vitrines that lend them a radioactive glow, an inexplicably threatening tumbleweed of metal wire, and a diorama-style cutout of a castle that is periodically closed as its motorized base claps shut.