  I review gamma-ray burst models (GRBs) and observations, and discuss the
possible production of ultra-high energy cosmic rays and neutrinos in both the
standard internal shock models and the newer generation of photospheric and
hadronic GRB models, in the light of current constraints imposed by IceCube,
Auger and TA observations. I then discuss models that have been proposed to
explain the recent astrophysical PeV neutrino observations, including
star-forming and star-burst galaxies, hypernovae and galaxy accretion and
merger shocks.
