  Effects on atmospheric prompt neutrino fluxes of present uncertainties
affecting the nucleon composition are studied by using the PROSA fit to parton
distribution functions (PDFs). The PROSA fit extends the precision of the PDFs
to low x, which is the kinematic region of relevance for high-energy neutrino
production, by taking into account LHCb data on charm and bottom
hadroproduction. In the range of neutrino energies explored by present Very
Large Volume Neutrino Telescopes, it is found that PDF uncertainties are far
smaller with respect to those due to renormalization and factorization scale
variation and to assumptions on the cosmic ray composition, which at present
dominate and limit our knowledge of prompt neutrino fluxes. A discussion is
presented on how these uncertainties affect the expected number of atmospheric
prompt neutrino events in the analysis of high-energy events characterized by
interaction vertices fully contained within the instrumented volume of the
detector, performed by the IceCube collaboration.
