46 research outputs found
QCD evolution of superfast quarks
Recent high-precision measurements of nuclear deep inelastic scattering at high x and moderate 6superfast region, in which the momentum fraction of the nucleon carried by its constituent quark is larger than the total fraction of the nucleon at rest, x\u3e1. We derive the leading-order QCD evolution equation for such quarks with the goal of relating the moderate-Q2 data to the two earlier measurements of superfast quark distributions at large 601.1 region is somewhat in the middle of the neutrino-nuclear and muon-nuclear scattering data
Another exact inflationary solution
A new closed-form inflationary solution is given for a hyperbolic interaction
potential. The method used to arrive at this solution is outlined as it appears
possible to generate additional sets of equations which satisfy the model. In
addition a new form of decaying cosmological constant is presented.Comment: 10 pages, 0 figure
Probing superfast quarks in nuclei through dijet production at the LHC
We investigate dijet production from proton-nucleus collisions at the Large
Hadron Collider (LHC) as a means for observing superfast quarks in nuclei with
Bjorken . Kinematically, superfast quarks can be identified through
directly measurable jet kinematics. Dynamically, their description requires
understanding several elusive properties of nuclear QCD, such as nuclear forces
at very short distances, as well as medium modification of parton distributions
in nuclei. In the present work, we develop a model for nuclear parton
distributions at large in which the nuclear dynamics at short distance
scales are described by two- and three-nucleon short range correlations (SRCs).
Nuclear modifications are accounted for using the color screening model, and an
improved description of the EMC effect is reached by using a structure function
parametrization that includes higher-twist contributions. We apply QCD
evolution at the leading order to obtain nuclear parton distributions in the
kinematic regime of the LHC, and based on the obtained distributions calculate
the cross section for dijet production. We find not only that superfast quarks
can be observed at the LHC, but also that they provide sensitivity to the
practically unexplored three-nucleon SRCs in nuclei. Additionally, the LHC can
extend our knowledge of the EMC effect to large where higher-twist
effects are negligible.Comment: 44 pages, 17 figures, final version to be published in EJP
Polygenic prediction of educational attainment within and between families from genome-wide association analyses in 3 million individuals
Publisher Copyright: © 2022, The Author(s).We conduct a genome-wide association study (GWAS) of educational attainment (EA) in a sample of ~3 million individuals and identify 3,952 approximately uncorrelated genome-wide-significant single-nucleotide polymorphisms (SNPs). A genome-wide polygenic predictor, or polygenic index (PGI), explains 12–16% of EA variance and contributes to risk prediction for ten diseases. Direct effects (i.e., controlling for parental PGIs) explain roughly half the PGI’s magnitude of association with EA and other phenotypes. The correlation between mate-pair PGIs is far too large to be consistent with phenotypic assortment alone, implying additional assortment on PGI-associated factors. In an additional GWAS of dominance deviations from the additive model, we identify no genome-wide-significant SNPs, and a separate X-chromosome additive GWAS identifies 57.Peer reviewe
Physiological Correlates of Volunteering
We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation
AIC, BIC, Bayesian evidence against the interacting dark energy model
Recent astronomical observations have indicated that the Universe is in the
phase of accelerated expansion. While there are many cosmological models which
try to explain this phenomenon, we focus on the interacting CDM model
where the interaction between the dark energy and dark matter sectors takes
place. This model is compared to its simpler alternative---the CDM
model. To choose between these models the likelihood ratio test was applied as
well as the model comparison methods (employing Occam's principle): the Akaike
information criterion (AIC), the Bayesian information criterion (BIC) and the
Bayesian evidence. Using the current astronomical data: SNIa (Union2.1),
, BAO, Alcock--Paczynski test and CMB we evaluated both models. The
analyses based on the AIC indicated that there is less support for the
interacting CDM model when compared to the CDM model, while
those based on the BIC indicated that there is the strong evidence against it
in favor the CDM model. Given the weak or almost none support for the
interacting CDM model and bearing in mind Occam's razor we are
inclined to reject this model.Comment: LaTeX svjour3, 12 pages, 3 figure
Polygenic prediction of educational attainment within and between families from genome-wide association analyses in 3 million individuals
We conduct a genome-wide association study (GWAS) of educational attainment (EA) in a sample of ~3 million individuals and identify 3,952 approximately uncorrelated genome-wide-significant single-nucleotide polymorphisms (SNPs). A genome-wide polygenic predictor, or polygenic index (PGI), explains 12-16% of EA variance and contributes to risk prediction for ten diseases. Direct effects (i.e., controlling for parental PGIs) explain roughly half the PGI's magnitude of association with EA and other phenotypes. The correlation between mate-pair PGIs is far too large to be consistent with phenotypic assortment alone, implying additional assortment on PGI-associated factors. In an additional GWAS of dominance deviations from the additive model, we identify no genome-wide-significant SNPs, and a separate X-chromosome additive GWAS identifies 57