1,930 research outputs found
Structure functions for light nuclei
We discuss the nuclear EMC effect with particular emphasis on recent data for
light nuclei including 2H, 3He, 4He, 9Be, 12C and 14N. In order to verify the
consistency of available data, we calculate the \chi^2 deviation between
different data sets. We find a good agreement between the results from the NMC,
SLAC E139, and HERMES experiments. However, our analysis indicates an overall
normalization offset of about 2% in the data from the recent JLab E03-103
experiment with respect to previous data for nuclei heavier than 3He. We also
discuss the extraction of the neutron/proton structure function ratio F2n/F2p
from the nuclear ratios 3He/2H and 2H/1H. Our analysis shows that the E03-103
data on 3He/2H require a renormalization of about 3% in order to be consistent
with the F2n/F2p ratio obtained from the NMC experiment. After such a
renormalization, the 3He data from the E03-103 data and HERMES experiments are
in a good agreement. Finally, we present a detailed comparison between data and
model calculations, which include a description of the nuclear binding, Fermi
motion and off-shell corrections to the structure functions of bound proton and
neutron, as well as the nuclear pion and shadowing corrections. Overall, a good
agreement with the available data for all nuclei is obtained.Comment: 18 pages, 7 figures, 5 tables, final version published in Phys. Rev.
The fifth most prevalent disease is being neglected by public health organisations
The progress towards reduction of global mortality has produced an epidemiological transition towards non-fatal diseases, which challenge the ability of the world’s population to live in full health. Although traumatic dental injuries are not lethal, their treatment is more expensive (US$2 000 000–5 000 000 per million inhabitants) and time-consuming than that of all the other bodily injuries, making dental rehabilitation less likely among disadvantaged individuals. Since untreated traumatic dental injuries have a negative social, functional, and emotional effect in children and adolescents, differences in treatment of these injuries between children from different countries and social classes produce disparities in their quality of life
Ecologic association between influenza and COVID-19 mortality rates in European countries
Ecologic studies investigating COVID-19 mortality determinants, used to make predictions and design public health control measures, generally focused on population-based variable counterparts of individual-based risk factors. Influenza is not causally associated with COVID-19, but shares population-based determinants, such as similar incidence/mortality trends, transmission patterns, efficacy of non-pharmaceutical interventions, comorbidities and underdiagnosis. We investigated the ecologic association between influenza mortality rates and COVID-19 mortality rates in the European context. We considered the 3-year average influenza (2014-2016) and COVID-19 (31 May 2020) crude mortality rates in 34 countries using EUROSTAT and ECDC databases and performed correlation and regression analyses. The two variables - log transformed, showed significant Spearman's correlation ρ = 0.439 (P = 0.01), and regression coefficients, b = 0.743 (95% confidence interval, 0.272-1.214; R2 = 0.244; P = 0.003), b = 0.472 (95% confidence interval, 0.067-0.878; R2 = 0.549; P = 0.02), unadjusted and adjusted for confounders (population size and cardiovascular disease mortality), respectively. Common significant determinants of both COVID-19 and influenza mortality rates were life expectancy, influenza vaccination in the elderly (direct associations), number of hospital beds per population unit and crude cardiovascular disease mortality rate (inverse associations). This analysis suggests that influenza mortality rates were independently associated with COVID-19 mortality rates in Europe, with implications for public health preparedness, and implies preliminary undetected SARS-CoV-2 spread in Europe
Modeling Lepton-Nucleon Inelastic Scattering from High to Low Momentum Transfer
We present a model for inclusive charged lepton-nucleon and
(anti)neutrino-nucleon cross sections at momentum transfer squared, ,
. We quantify the impact of existing low-Q charged-lepton
deep-inelastic scattering (DIS) data on effects due to high-twist operators and
on the extraction of parton distribution functions (PDFs). No evidence is found
for twist-6 contributions to structure functions (SF), and for a twist-4 term
in the logitudinal SF at . We find that DIS data are consistent
with the NNLO QCD approximation with the target mass and phenomenological high
twist corrections. For , we extend extrapolation of the
operator product expansion, preserving the low- current-conservation
theorems. The procedure yields a good description of data down to . An updated set of PDFs with reduced uncertainty and applicable
down to small momentum transfers in the lepton-nucleon scattering is obtained.Comment: 10 pages, 6 figures, proceedings of the 5th International Workshop on
Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07), Batavia,
Illinois, 30 May - 3 Jun 200
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