627 research outputs found
Scales for co-compact embeddings of virtually free groups
Let be a group which is virtually free of rank at least 2 and let
be the family of totally disconnected, locally
compact groups containing as a co-compact lattice.
We prove that the values of the scale function with respect to groups in
evaluated on the subset have only finitely
many prime divisors. This can be thought of as a uniform property of the family
.Comment: 12 pages; key words: uniform lattice, virtually free group, totally
disconnected group, scale function (Error in references corrected in version
2
Powerless people don't yell but tell: The effects of social power on direct and indirect expression of anger
Clinical Evidence Supports a Protective Role for CXCL5 in Coronary Artery Disease
Our goal was to measure the association of CXCL5 and molecular phenotypes associated with coronary atherosclerosis severity in patients at least 65 years old. CXCL5 is classically defined as a proinflammatory chemokine, but its role in chronic inflammatory diseases, such as coronary atherosclerosis, is not well defined. We enrolled individuals who were at least 65 years old and undergoing diagnostic cardiac catheterization. Coronary artery disease (CAD) severity was quantified in each subject via coronary angiography by calculating a CAD score. Circulating CXCL5 levels were measured from plasma, and both DNA genotyping and mRNA expression levels in peripheral blood mononuclear cells were quantified via microarray gene chips. We observed a negative association of CXCL5 levels with CAD at an odds ratio (OR) of 0.46 (95% CI, 0.27â0.75). Controlling for covariates, including sex, statin use, hypertension, hyperlipidemia, obesity, self-reported race, smoking, and diabetes, the OR was not significantly affected [OR, 0.54 (95% CI, 0.31â0.96)], consistent with a protective role for CXCL5 in coronary atherosclerosis. We also identified 18 genomic regions with expression quantitative trait loci of genes correlated with both CAD severity and circulating CXCL5 levels. Our clinical findings are consistent with the emerging link between chemokines and atherosclerosis and suggest new therapeutic targets for CAD
Algebraic entropy in locally linearly compact vector spaces
We introduce algebraic entropy for continuous endomorphisms of locally linearly compact vector spaces over a discrete field, as a natural extension of the algebraic entropy for endomorphisms of discrete vector spaces studied in Giordano Bruno and Salce (Arab J Math 1:69\u201387, 2012). We show that the main properties continue to hold in the general context of locally linearly compact vector spaces, in particular we extend the Addition Theorem
A new calibrated sunspot group series since 1749: statistics of active day fractions
Although the sunspot-number series have existed since the mid-19th century, they are still the subject of intense debate, with the largest uncertainty being related to the "calibration" of the visual acuity of individual observers in the past. Daisy-chain regression methods are applied to inter-calibrate the observers which may lead to significant bias and error accumulation. Here we present a novel method to calibrate the visual acuity of the key observers to the reference data set of Royal Greenwich Observatory sunspot groups for the period 1900-1976, using the statistics of the active-day fraction. For each observer we independently evaluate their observational thresholds [S_S] defined such that the observer is assumed to miss all of the groups with an area smaller than S_S and report all the groups larger than S_S. Next, using a Monte-Carlo method we construct, from the reference data set, a correction matrix for each observer. The correction matrices are significantly non-linear and cannot be approximated by a linear regression or proportionality. We emphasize that corrections based on a linear proportionality between annually averaged data lead to serious biases and distortions of the data. The correction matrices are applied to the original sunspot group records for each day, and finally the composite corrected series is produced for the period since 1748. The corrected series displays secular minima around 1800 (Dalton minimum) and 1900 (Gleissberg minimum), as well as the Modern grand maximum of activity in the second half of the 20th century. The uniqueness of the grand maximum is confirmed for the last 250 years. It is shown that the adoption of a linear relationship between the data of Wolf and Wolfer results in grossly inflated group numbers in the 18th and 19th centuries in some reconstructions
Photoproduction of mesons off nuclei
Recent results for the photoproduction of mesons off nuclei are reviewed.
These experiments have been performed for two major lines of research related
to the properties of the strong interaction. The investigation of nucleon
resonances requires light nuclei as targets for the extraction of the isospin
composition of the electromagnetic excitations. This is done with quasi-free
meson photoproduction off the bound neutron and supplemented with the
measurement of coherent photoproduction reactions, serving as spin and/or
isospin filters. Furthermore, photoproduction from light and heavy nuclei is a
very efficient tool for the study of the interactions of mesons with nuclear
matter and the in-medium properties of hadrons. Experiments are currently
rapidly developing due to the combination of high quality tagged (and
polarized) photon beams with state-of-the-art 4pi detectors and polarized
targets
Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV
We report the results of a study of color coherence effects in ppbar
collisions based on data collected by the D0 detector during the 1994-1995 run
of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8
TeV. Initial-to-final state color interference effects are studied by examining
particle distribution patterns in events with a W boson and at least one jet.
The data are compared to Monte Carlo simulations with different color coherence
implementations and to an analytic modified-leading-logarithm perturbative
calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters
Improved W boson mass measurement with the D0 detector
We have measured the W boson mass using the D0 detector and a data sample of
82 pb^-1 from the Tevatron collider. This measurement used W -> e nu decays,
where the electron is close to a boundary of a central electromagnetic
calorimeter module. Such 'edge' electrons have not been used in any previous D0
analysis, and represent a 14% increase in the W boson sample size. For these
electrons, new response and resolution parameters are determined, and revised
backgrounds and underlying event energy flow measurements are made. When the
current measurement is combined with previous D0 W boson mass measurements, we
obtain M_W = 80.483 +/- 0.084 GeV. The 8% improvement from the previous D0
measurement is primarily due to the improved determination of the response
parameters for non-edge electrons using the sample of Z bosons with non-edge
and edge electrons.Comment: submitted to Phys. Rev. D; 20 pages, 18 figures, 9 table
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in âs = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fbâ1 of protonâproton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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