  Cosmological constraints on the sum of neutrino masses and on the effective
number of neutrino species in standard and non-standard scenarios are computed
using the most recent available cosmological data. Our cosmological data sets
include the measurement of the Baryonic Acoustic Oscillation (BAO) feature in
the Data Release 9 CMASS sample of the Baryon Oscillation Spectroscopic Survey
(BOSS). We study in detail the different degeneracies among the parameters, as
well as the impact of the different data sets used in the analyses. When
considering bounds on the sum of the three active neutrino masses, the
information in the BAO signal from galaxy clustering measurements is
approximately equally powerful as the shape information from the matter power
spectrum. The most stringent bound we find is sum m_nu<0.32 eV at 95 % CL. When
non-standard neutrino scenarios with neff massless or massive neutrino species
are examined, power spectrum shape measurements provide slightly better bounds
than the BAO signal only, due to the breaking of parameter degeneracies. Recent
BOSS data combined with CMB and Hubble Space Telescope measurements give
neff=3.66^{+0.20 +0.73}_{-0.21 -0.69} in the massless neutrino scenario, and
similar results are obtained in the massive case. The evidence for extra
radiation neff>3 often claimed in the literature therefore remains at the 2
sigma level when considering up-to-date cosmological data sets. Measurements
from the Wilkinson Microwave Anisotropy Probe combined with a prior on the
Hubble parameter from the Hubble Space Telescope are very powerful in
constraining either the sum of the three active neutrino masses or the number
of massless neutrino species. If the former two parameters are allowed to
freely vary, however, the bounds from the combination of these two cosmological
probes get worse by an order of magnitude.
