2,944 research outputs found
State Level Earned Income Tax Credit’s Effects on Race and Age: An Effective Poverty Reduction Policy
In this paper, I analyze the effectiveness of state level Earned Income Tax Credit programs on improving of poverty levels. I conducted this analysis for the years 1991 through 2011 using a panel data model with fixed effects. The main independent variables of interest were the state and federal EITC rates, minimum wage, gross state product, population, and unemployment all by state. I determined increases to the state EITC rates provided only a slight decrease to both the overall white below-poverty population and the corresponding white childhood population under 18, while both the overall and the under-18 black population for this category realized moderate decreases in their poverty rates for the same time period. I also provide a comparison of the effectiveness of the state level EITCs and minimum wage at the state level over the same time period on these select demographic groups
Asymmetric Quark/Antiquark Hadronization in e+e- Annihilation
We point out that the fragmentation of a strange quark into nucleons versus
antinucleons is not necessarily identical , even though the perturbative contributions from gluon splitting
and evolution are symmetric. The observation of such
asymmetries in the hadronization of strange and other heavy quarks can provide
insight into the nonperturbative mechanisms underlying jet fragmentation in
QCD.Comment: Latex, 12 page
Chiral-odd transversity spin structure function of the nucleon in a constituent quark model
We study the chiral-odd transversity spin-dependent quark distribution
function of the nucleon in a constituent quark model. The twist-2
structure functions, , and are calculated within the
diquark spectator approximation. Whereas an inequality holds with the interaction between quark and diquark being scalar, the
axial-vector effective quark-diquark interaction, which contributes to the
-quark distribution, does not lead to such a simple relation. We find that
for the -quark becomes somewhat smaller than , when we
fix the model parameter to reproduce known other structure functions. We also
include corrections due to the non-trivial structure of the constituent quark,
which is modeled by the Goldstone boson dressing. This improves agreements of
and with experiments, and brings further reduction of
distribution. Consequences for semi-inclusive experiments are also
discussed.Comment: 33 pages, latex with 13 figures, to appear in Nuclear Physics A,
PostScript file is also available at
http://WWW.physik.tu-muenchen.de/~ksuzuki/publication.htm
Workshop to identify critical windows of exposure for children\u27s health: Neurobehavioral work group summary
Summarizes the deliberations of a work group charged with addressing specific questions relevant to risk estimation in developmental neurotoxicology. Importance of multiple factors addressing critical windows of exposure on neurological function; Role that compensatory mechanisms play in the manifestation of the effects of developmental exposures
Nucleon quark distributions in a covariant quark-diquark model
Spin-dependent and spin-independent quark light-cone momentum distributions
and structure functions are calculated for the nucleon. We utilize a modified
Nambu-Jona-Lasinio model in which confinement is simulated by eliminating
unphysical thresholds for nucleon decay into quarks. The nucleon bound state is
obtained by solving the Faddeev equation in the quark-diquark approximation,
where both scalar and axial-vector diquark channels are included. We find
excellent agreement between our model results and empirical data.Comment: 6 pages, 7 figure
Polarized Parton Distributiions and Light-Front Dynamics
We present a consistent calculation of the structure functions within a
light-front constituent quark model of the nucleon. Relativistic effects and
the relevance of the covariance constraints are analyzed for both polarized and
unpolarized parton distributions. Various models, which differ in their gluonic
structure at the hadronic scale, are investigated. The results of the full
covariant calculation are compared with those of a non-relativistic
approximation to show the structure and magnitude of the differences.Comment: 31 pages, 9 figures, major revisio
Mechanistic modeling to predict titers and infected cells in the two-stage continuous production of a viral vaccine
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Interlayer c-axis transport in the normal state of cuprates
A theoretical model of c-axis transport properties in cuprates is proposed.
Inter-plane and in-plane charge fluctuations make hopping between planes
incoherent and diffusive (the in-plane momentum is not conserved after
tunneling). The non-Drude optical conductivity and the
power-law temperature dependence of the {\it dc} conductivity are generically
explained by the strong fluctuations excited in the process of tunneling.
Several microscopic models of the charge fluctuation spectrum are considered.Comment: 8 page
Lorentz invariance relations between parton distributions and the Wandzura-Wilczek approximation
The violation of the so-called Lorentz invariance relations between parton
distribution functions is considered in a model independent way. It is shown
that these relations are not violated in a generalized Wandzura-Wilczek
approximation, indicating that numerically their violation may be small.Comment: 13 pages, added references, minor changes, to appear in Phys. Lett.
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