2,585 research outputs found
Ozone Measurements in the Mesosphere During a Solar Proton Event
Charged particle precipitation in the Earth's atmosphere produces odd nitrogen and odd hydrogen. These species take part in catalytic reactions which destroy atmospheric ozone in the stratosphere and mesosphere. Modeling efforts regarding the impact of these ionization events on the neutral atmosphere describe ozone depletions in good agreement with observations in the stratosphere and mesosphere. The photochemical effects of the solar proton event (SPE) of August 1972 are discussed, and calculations for higher altitudes (70 to 90 km) are presented that indicate after a brief reduction during and immediately following intense particle precipitation, ozone will later reach higher concentrations than those present before the event
Study of Viable Seeds In Surface Soil From Various Habitats In Ellis County, Kansas.
It is the purpose of this study to determine what species of plants emerge from samples of surface soil taken from various habitats after several years of favorable growing conditions
Teaching Twelfth Night and Queering the Canon in Michigan English Language Arts Classrooms
Recent legislation across the country has advocated for the complete disregard of queer topics and identities within public school classrooms. Within this essay, I lay out the issues that stem from ignoring marginalized identities in the ELA classroom, specifically queer identities, and offer an example of a text (Shakespeare\u27s Twelfth Night) that can be used to incorporate discussion of queer identity into the curriculum
Helicity Dependent and Independent Generalized Parton Distributions of the Nucleon in Lattice QCD
A complete description of the nucleon structure in terms of generalized
parton distributions (GPDs) at twist 2 level requires the
measurement/computation of the eight functions H, E, \tilde H, \tilde E, H_T,
E_T, \tilde H_T and \tilde E_T, all depending on the three variables x, \xi and
t. In this talk, we present and discuss our first steps in the framework of
lattice QCD towards this enormous task. Dynamical lattice QCD results for the
lowest three Mellin moments of the helicity dependent and independent GPDs are
shown in terms of their corresponding generalized form factors. Implications
for the transverse coordinate space structure of the nucleon as well as the
orbital angular momentum (OAM) contribution of quarks to the nucleon spin are
discussed in some detail.Comment: 5 pages, 5 figures, Talk presented by Ph.H. at Electron-Nucleus
Scattering VIII, Elba, Italy, June 21-25, 2004; typos corrected, minor change
in wording on p.4&
Quantifying the uncertainty in heritability
The use of mixed models to determine narrow-sense heritability and related quantities such as SNP heritability has received much recent attention. Less attention has been paid to the inherent variability in these estimates. One approach for quantifying variability in estimates of heritability is a frequentist approach, in which heritability is estimated using maximum likelihood and its variance is quantified through an asymptotic normal approximation. An alternative approach is to quantify the uncertainty in heritability through its Bayesian posterior distribution. In this paper, we develop the latter approach, make it computationally efficient and compare it to the frequentist approach. We show theoretically that, for a sufficiently large sample size and intermediate values of heritability, the two approaches provide similar results. Using the Atherosclerosis Risk in Communities cohort, we show empirically that the two approaches can give different results and that the variance/uncertainty can remain large
QCD thermodynamics with dynamical overlap fermions
We study QCD thermodynamics using two flavors of dynamical overlap fermions
with quark masses corresponding to a pion mass of 350 MeV. We determine several
observables on N_t=6 and 8 lattices. All our runs are performed with fixed
global topology. Our results are compared with staggered ones and a nice
agreement is found.Comment: 14 pages, 6 figures, 1 tabl
Calculation of Nucleon Electromagnetic Form Factors
The fomalism is developed to express nucleon matrix elements of the
electromagnetic current in terms of form factors consistent with the
translational, rotational, and parity symmetries of a cubic lattice. We
calculate the number of these form factors and show how appropriate linear
combinations approach the continuum limit.Comment: Lattice 2002 (hadronic matrix elements) 3 page
Transverse Structure of Nucleon Parton Distributions from Lattice QCD
This work presents the first calculation in lattice QCD of three moments of
spin-averaged and spin-polarized generalized parton distributions in the
proton. It is shown that the slope of the associated generalized form factors
decreases significantly as the moment increases, indicating that the transverse
size of the light-cone quark distribution decreases as the momentum fraction of
the struck parton increases.Comment: 4 pages, 1 figur
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