\BOOKMARK [1][-]{section.1}{1. Introduction}{}
\BOOKMARK [1][-]{section.2}{2. The specialization method}{}
\BOOKMARK [1][-]{section.3}{3. Quadric surface bundles}{}
\BOOKMARK [1][-]{section.4}{4. The Brauer group of the special fiber}{}
\BOOKMARK [1][-]{section.5}{5. Singularities of the special fiber}{}
\BOOKMARK [1][-]{section.6}{6. Analysis of Hodge classes}{}
\BOOKMARK [1][-]{section.7}{7. Proof of Theorem 1}{}
\BOOKMARK [1][-]{section*.8}{References}{}