SEMINARS ANNOUCEMENT Gerardo Arizmendi (CIMAT, Mexico) Title: "Centralizers of spin subalgebras" Venue: SISSA, Friday 24 July at 11:00 in lecture room 136 Ivan Tellez (CIMAT, Mexico) Title: "Twisted partially pure spinors" Venue: SISSA, Monday 27 July at 11:00 in lecture room 136