6,071 research outputs found
B -> D* l nu and B -> D l nu form factors in staggered chiral perturbation theory
We calculate the B -> D and B -> D* form factors at zero recoil in Staggered
Chiral Perturbation Theory. We consider heavy-light mesons in which only the
light (u, d, or s) quark is staggered; current lattice simulations generally
use a highly improved action such as the Fermilab or NRQCD action for the heavy
(b or c) quark. We work to lowest nontrivial order in the heavy quark expansion
and to one-loop in the chiral expansion. We present results for a partially
quenched theory with three sea quarks in which there are no mass degeneracies
(the "1+1+1" theory) and for a partially quenched theory in which the u and d
sea quark masses are equal (the "2+1" theory). We also present results for full
(2+1) QCD, along with a numerical estimate of the size of staggered
discretization errors. Finally, we calculate the finite volume corrections to
the form factors and estimate their numerical size in current lattice
simulations.Comment: 19 pages, 6 figures, references added, expanded discussion in Section
I
Association of a MET genetic variant with autism-associated maternal autoantibodies to fetal brain proteins and cytokine expression.
The contribution of peripheral immunity to autism spectrum disorders (ASDs) risk is debated and poorly understood. Some mothers of children with ASD have autoantibodies that react to fetal brain proteins, raising the possibility that a subset of ASD cases may be associated with a maternal antibody response during gestation. The mechanism by which the maternal immune system breaks tolerance has not been addressed. We hypothesized that the mechanism may involve decreased expression of the MET receptor tyrosine kinase, an ASD risk gene that also serves as a key negative regulator of immune responsiveness. In a sample of 365 mothers, including 202 mothers of children with ASD, the functional MET promoter variant rs1858830 C allele was strongly associated with the presence of an ASD-specific 37+73-kDa band pattern of maternal autoantibodies to fetal brain proteins (P=0.003). To determine the mechanism of this genetic association, we measured MET protein and cytokine production in freshly prepared peripheral blood mononuclear cells from 76 mothers of ASD and typically developing children. The MET rs1858830 C allele was significantly associated with MET protein expression (P=0.025). Moreover, decreased expression of the regulatory cytokine IL-10 was associated with both the MET gene C allele (P=0.001) and reduced MET protein levels (P=0.002). These results indicate genetic distinction among mothers who produce ASD-associated antibodies to fetal brain proteins, and suggest a potential mechanism for how a genetically determined decrease in MET protein production may lead to a reduction in immune regulation
Impact of community water systems in small towns
The primary purpose of this study was to describe the impact the addition of a community water system to a small town would have upon that town and the surrounding communities. The benefits of the system were recognized by the residents and some of the first round impacts were measured. Benefits observed were increases in the number of water using appliances, increases in property values, improved fire protection and sanitary conditions. Several factors need to be considered when planning future water systems as to the calculation of future needs of the system. Changes which can be expected in population and business activity, changes in the number of water using appliances, and other factors all need to be considered when planning for the successful installation and operation of a community water system. Ample quantities of water are available in Illinois, but intelligent planning for increasing needs, careful management of water supply, and improved waste disposal are essential. Rural people are showing increased concern and are taking action to maintain an abundant supply of clear, safe water for the future.U.S. Department of the InteriorU.S. Geological SurveyOpe
Maternal antibodies from mothers of children with autism alter brain growth and social behavior development in the rhesus monkey.
Antibodies directed against fetal brain proteins of 37 and 73 kDa molecular weight are found in approximately 12% of mothers who have children with autism spectrum disorder (ASD), but not in mothers of typically developing children. This finding has raised the possibility that these immunoglobulin G (IgG) class antibodies cross the placenta during pregnancy and impact brain development, leading to one form of ASD. We evaluated the pathogenic potential of these antibodies by using a nonhuman primate model. IgG was isolated from mothers of children with ASD (IgG-ASD) and of typically developing children (IgG-CON). The purified IgG was administered to two groups of female rhesus monkeys (IgG-ASD; n=8 and IgG-CON; n=8) during the first and second trimesters of pregnancy. Another control group of pregnant monkeys (n=8) was untreated. Brain and behavioral development of the offspring were assessed for 2 years. Behavioral differences were first detected when the macaque mothers responded to their IgG-ASD offspring with heightened protectiveness during early development. As they matured, IgG-ASD offspring consistently deviated from species-typical social norms by more frequently approaching familiar peers. The increased approach was not reciprocated and did not lead to sustained social interactions. Even more striking, IgG-ASD offspring displayed inappropriate approach behavior to unfamiliar peers, clearly deviating from normal macaque social behavior. Longitudinal magnetic resonance imaging analyses revealed that male IgG-ASD offspring had enlarged brain volume compared with controls. White matter volume increases appeared to be driving the brain differences in the IgG-ASD offspring and these differences were most pronounced in the frontal lobes
The Kaon B-parameter in Mixed Action Chiral Perturbation Theory
We calculate the kaon B-parameter, B_K, in chiral perturbation theory for a
partially quenched, mixed action theory with Ginsparg-Wilson valence quarks and
staggered sea quarks. We find that the resulting expression is similar to that
in the continuum, and in fact has only two additional unknown parameters. At
one-loop order, taste-symmetry violations in the staggered sea sector only
contribute to flavor-disconnected diagrams by generating an O(a^2) shift to the
masses of taste-singlet sea-sea mesons. Lattice discretization errors also give
rise to an analytic term which shifts the tree-level value of B_K by an amount
of O(a^2). This term, however, is not strictly due to taste-breaking, and is
therefore also present in the expression for B_K for pure G-W lattice fermions.
We also present a numerical study of the mixed B_K expression in order to
demonstrate that both discretization errors and finite volume effects are small
and under control on the MILC improved staggered lattices.Comment: 29 pages, 4 figures; Expanded spurion discussion, other discussions
clarified, version to appear in PR
Navigating a Pathway Toward Colorado\u27s Water Future: A Review and Recommendations on Colorado\u27s Draft Water Plan
40 pages (includes color illustrations).https://scholar.law.colorado.edu/books_reports_studies/1155/thumbnail.jp
Navigating a Pathway Toward Colorado\u27s Water Future: A Review and Recommendations on Colorado\u27s Draft Water Plan
40 pages (includes color illustrations).https://scholar.law.colorado.edu/books_reports_studies/1155/thumbnail.jp
The hadronic vacuum polarization contribution to from full lattice QCD
We determine the contribution to the anomalous magnetic moment of the muon
from the hadronic vacuum polarization diagram using
full lattice QCD and including quarks with physical masses for the first
time. We use gluon field configurations that include , , and
quarks in the sea at multiple values of the lattice spacing, multiple
masses and multiple volumes that allow us to include an analysis of
finite-volume effects. We obtain a result for of
, where the first error is from the lattice calculation and the
second includes systematic errors from missing QED and isospin-breaking effects
and from quark-line disconnected diagrams. Our result implies a discrepancy
between the experimental determination of and the Standard Model of
3.Comment: 14 pages, 10 figures. Discussion of method extended with additional
tests and figures added. Typographical errors correcte
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