2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/200490The possibility of constructing a model in which right-handed neutrinos have electroweak-scale masses as well as being {\em non-sterile} was espoused in Ref. 1. In this talk, I will review the ideas and results of Ref. 1 and discuss its implications for colliders such as the Tevatron, LHC and ILC.11 pages, no figures. Prepared for Les Rencontres de Physique de La Vallee d'Aoste, March 4-10, 2007, La Thuile, Vallee d'Aoste, ItalyHigh Energy Physics - Phenomenologytext