Tau neutrinos from active galactic nuclei
  We study the appearance of $\nu_{\tau}$ from active galactic nuclei (AGN) through neutrino spin-flip. We consider two situations: i) Spin (flavour)-precession in a reasonable strength of magnetic field in AGN, $B_{AGN}$ ii) Adiabatically resonant conversions caused by an interplay of $B_{AGN}$ and the violation of equivalence principle. Observational consequences for both situations are discussed. 
Athar Husain (Universidade de Santiago de Compostela, Spain)