2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/194871In this contribution to the Festschrift celebrating Gabriele Veneziano on his 65th birthday, I discuss the threshold effects of extra dimensions and their applications to physics beyond the standard model, focusing on superstring theory.To appear in the book "String theory and fundamental interactions" (published in celebration of the 65th birthday of Gabriele Veneziano), eds. M. Gasperini and J. Maharana (Lecture Notes in Physics, Springer Berlin/Heidelberg, 2007High Energy Physics - Theorytext