2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/75823We study the Noether-Lefschetz locus of a very ample line bundle L on an arbitrary smooth threefold Y. Building on results of Green, Voisin and Otwinowska, we give explicit bounds, depending only on the Castelnuovo-Mumford regularity properties of L, on the codimension of the components of the Noether-Lefschetz locus of |L|.30 pages, LatexAlgebraic Geometry14J10; 14J30text