New two-sided bound on the isotropic Lorentz-violating parameter of modified Maxwell theory

There is a unique Lorentz-violating modification of the Maxwell theory of photons, which maintains gauge invariance, CPT, and renormalizability. Restricting the modified-Maxwell theory to the isotropic sector and adding a standard spin-one-half Dirac particle p^\pm with minimal coupling to the nonstandard photon \widetilde{\gamma}, the resulting modified-quantum-electrodynamics model involves a single dimensionless "deformation parameter," \widetilde{\kappa}_{tr}. The exact tree-level decay rates for two processes have been calculated: vacuum Cherenkov radiation p^\pm \to p^\pm \widetilde{\gamma} for the case of positive \widetilde{\kappa}_{tr} and photon decay \widetilde{\gamma} \to p^+ p^- for the case of negative \widetilde{\kappa}_{tr}. From the inferred absence of these decays for a particular high-quality ultrahigh-energy-cosmic-ray event detected at the Pierre Auger Observatory and an excess of TeV gamma-ray events observed by the High Energy Stereoscopic System telescopes, a two-sided bound on \widetilde{\kappa}_{tr} is obtained, which improves by eight orders of magnitude upon the best direct laboratory bound. The implications of this result are briefly discussed.Comment: 18 pages, v5: published version in preprint styl

Unstable Giants

We find giant graviton solutions in Frolov's three parameter generalization of the Lunin-Maldacena background. The background we study has $\tilde{\gamma}_1=0$ and $\tilde{\gamma}_2=\tilde{\gamma}_3=\tilde{\gamma}$. This class of backgrounds provide a non-superymmetric example of the gauge theory/gravity correspondence that can be tested quantitatively, as recently shown by Frolov, Roiban and Tseytlin. The giant graviton solutions we find have a greater energy than the point gravitons, making them unstable states. Despite this, we find striking quantitative agreement between the gauge theory and gravity descriptions of open strings attached to the giant.Comment: 1+24 pages, 2 figures; v2: coupling to NSNS B field included, refs added and typos corrected; v3 new results on stability of giants included, presentation improved, refs added; v4 final version to appear in Phys. Rev.

Ecosystem Studies at Cedar Creek Natural History Area, III: Water Use Studies

Previous articles in this series (Lawrence et al. 1957-58, 1960) have dealt with the nature of ecosystems, history of the ecosystem analysis approach, and some of the objectives and the methods that have been used at the Cedar Creek Natural History Area of the University of Minnesota and the Minnesota Academy of Science. The area, which was acquired in large part through a generous grant from the Fleischmann Foundation, is located in Anoka and Isanti Counties in east central Minnesota. The work has been generously supported by the Hill Family Foundation since the early summer of 1957. One main objective has been to learn what becomes of the solar energy striking the landscape. It has been estimated from studies elsewhere that a rather large portion, probably over half of the energy which strikes a given level area, is expended in evaporation from non-living surfaces of open water and moist soil, and in transpiration from living plant surfaces. The combined vaporization is called evapotranspiration. The Cedar Creek area is especially well suited for studying these water losses, or uses as we shall consider them here, because such a large variety of surfaces occur in close proximity to one another, and because water surface is exposer in ponds and the water table is usually at the surface or within a few inches of the surface in willow, alder, and tamarack swamps

Effects of Short-term 3-Day Caloric Restriction on Cardiometabolic Health in Overweight and Obese Individuals

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Maintaining Professional Face: Deceptive Impression Management in Community Sport Coaching

This article breaks new ground in the sociology of sports work through its novel exploration of workplace deception and the associated development of an original typology of deceptive impression management. Analysis of data collected from a two-phased research design, comprising online interviews and survey responses from 102 participants, revealed that community sport coaches employed deceptive impression management to display emotional control, an ideal practice of their work, and to feign expert knowledge. These types of deceptive impression management consisted of disguising disdain, flattering insincerely, camouflaging alternative approaches, covering-up mistakes, hiding a lack of expected knowledge, and reporting favourable metrics. Drawing on theories of dramaturgical analysis (Goffman, 1959, 1967, 1974) and emotional labour (Hochschild, 1979, 1983) as used in constructing a professional image, we examine how the coaches used deception to cope with challenging work circumstances that endanger projecting a professional appearance. The present article not only advances our sociological understanding of sports work but raises important questions for the preparation, development, and support of sports workers

Febuxostat, an Inhibitor of Xanthine Oxidase, Suppresses Lipopolysaccharide-Induced MCP-1 Production via MAPK Phosphatase-1-Mediated Inactivation of JNK.

Excess reactive oxygen species (ROS) formation can trigger various pathological conditions such as inflammation, in which xanthine oxidase (XO) is one major enzymatic source of ROS. Although XO has been reported to play essential roles in inflammatory conditions, the molecular mechanisms underlying the involvement of XO in inflammatory pathways remain unclear. Febuxostat, a selective and potent inhibitor of XO, effectively inhibits not only the generation of uric acid but also the formation of ROS. In this study, therefore, we examined the effects of febuxostat on lipopolysaccharide (LPS)-mediated inflammatory responses. Here we show that febuxostat suppresses LPS-induced MCP-1 production and mRNA expression via activating MAPK phosphatase-1 (MKP-1) which, in turn, leads to dephosphorylation and inactivation of JNK in macrophages. Moreover, these effects of febuxostat are mediated by inhibiting XO-mediated intracellular ROS production. Taken together, our data suggest that XO mediates LPS-induced phosphorylation of JNK through ROS production and MKP-1 inactivation, leading to MCP-1 production in macrophages. These studies may bring new insights into the novel role of XO in regulating inflammatory process through MAPK phosphatase, and demonstrate the potential use of XO inhibitor in modulating the inflammatory processes

A Catalog of Background Stars Reddened by Dust in the Taurus Dark Clouds

Normal field stars located behind dense clouds are a valuable resource in interstellar astrophysics, as they provide continua in which to study phenomena such as gas-phase and solid-state absorption features, interstellar extinction and polarization. This paper reports the results of a search for highly reddened stars behind the Taurus Dark Cloud complex. We use the Two Micron All Sky Survey (2MASS) Point Source Catalog to survey a 50 sq deg area of the cloud to a limiting magnitude of K = 10.0. Photometry in the 1.2-2.2 micron passbands from 2MASS is combined with photometry at longer infrared wavelengths (3.6-12 micron) from the Spitzer Space Telescope and the Infrared Astronomical Satellite to provide effective discrimination between reddened field stars and young stellar objects (YSOs) embedded in the cloud. Our final catalog contains 248 confirmed or probable background field stars, together with estimates of their total visual extinctions, which span the range 2-29 mag. We also identify the 2MASS source J04292083+2742074 (IRAS 04262+2735) as a previously unrecognized candidate YSO, based on the presence of infrared emission greatly in excess of that predicted for a normal reddened photosphere at wavelengths >5 microns

Oscillons: an encounter with dynamical chaos in 1953?

We present evidences that Ben F. Laposky (1914-2000) might have been the first person who created a family of nonlinear analog circuits that allowed him to observe chaotic attractors and other trademarks of nonlinear science as early as 1953.Comment: accepted to Chao