5,260 research outputs found

    The Kahler Structure of Supersymmetric Holographic RG Flows

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    We study the metrics on the families of moduli spaces arising from probing with a brane the ten and eleven dimensional supergravity solutions corresponding to renormalisation group flows of supersymmetric large n gauge theory. In comparing the geometry to the physics of the dual gauge theory, it is important to identify appropriate coordinates, and starting with the case of SU(n) gauge theories flowing from N=4 to N=1 via a mass term, we demonstrate that the metric is Kahler, and solve for the Kahler potential everywhere along the flow. We show that the asymptotic form of the Kahler potential, and hence the peculiar conical form of the metric, follows from special properties of the gauge theory. Furthermore, we find the analogous Kahler structure for the N=4 preserving Coulomb branch flows, and for an N=2 flow. In addition, we establish similar properties for two eleven dimensional flow geometries recently presented in the literature, one of which has a deformation of the conifold as its moduli space. In all of these cases, we notice that the Kahler potential appears to satisfy a simple universal differential equation. We prove that this equation arises for all purely Coulomb branch flows dual to both ten and eleven dimensional geometries, and conjecture that the equation holds much more generally.Comment: 26 pages. Late

    A method for calculating 16o/18o peptide ion ratios for the relative quantification of proteomes

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    AbstractA method is described for the identification and relative quantification of proteomes using accurate mass tags (AMT) generated by nLC-dual ESI-FT-ICR-MS on a 7T instrument in conjunction with stable isotope labeling using 16O/18O ratios. AMTs were used for putative peptide identification, followed by confirmation of peptide identity by tandem mass spectrometry. For a combined set of 58 tryptic peptides from bovine serum albumin (BSA) and human transferrin, a mean mass measurement accuracy of 1.9 ppm ±0.94 ppm (CIM99%) was obtained. This subset of tryptic peptides was used to measure 16O/18O ratios of 0.36 ± 0.09 (CIM99%) for BSA (μ = 0.33) and 1.48 ± 0.47 (CIM99%) for transferrin (μ = 1.0) using a method for calculating 16O/18O ratios from overlapping isotopic multiplets arising from mixtures of 16O, 18O1, and 18O2 labeled C-termini. The model amino acid averagine was used to calculate a representative molecular formula for estimating and subtracting the contributions of naturally occurring isotopes solely as a function of peptide molecular weight. The method was tested against simulated composite 16O/18O spectra where peptide molecular weight, 16O/18O ratio, 18O1/18O2 ratios, and number of sulfur atoms were varied. Relative errors of 20% or less were incurred when the 16O/18O ratios were less than three, even for peptides where the number of sulfur atoms was over- or under-estimated. These data demonstrate that for biomarker discovery, it is advantageous to label the proteome representing the disease state with 18O; and the method is not sensitive to variations in 18O1/18O2 ratio. This approach allows a comprehensive differentiation of expression levels and tentative identification via AMTs, followed by targeted analysis of over- and under-expressed peptides using tandem mass spectrometry, for applications such as the discovery of disease biomarkers

    Issues and indicators of acceptable change : a study of visitors’ and stakeholders’ concerns about three natural attractions in the Paparoa area, West Coast, South Island, New Zealand

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    This report presents results from visitor surveys and stakeholder interviews at three natural attractions in the Paparoa National Park. The sites were the Pancake Rocks (Dolomite Point), the Fox River caves, and the Westland Black Petrel colony. Questions in the surveys and interviews were based on the Limits of Acceptable Change (LAC) framework to identify potential indicators of change at the site, and were developed from previous studies using this system. The surveys gathered information on visitors' experience of the Pancake Rocks and Fox River caves, and people's sensitivity to impacts encountered at the sites. This was done using self-administered questionnaires on-site immediately after the visit. Stakeholders were interviewed about their issues and concerns for all three sites, and were asked to provide a list of potential indicators of acceptable change

    Did You Not Understand The Question Or Not? An Investigation Of Negatively Worded Questions In Survey Research

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    This study compared participant responses to negatively versus positively worded questionnaire statements.  The literature suggested that one could expect the wording of questionnaire items (i.e., negatively worded vs. positively worded) to influence participant responses to those scale items.  The study consisted of one control group and two experimental groups.   The Fashion Consciousness scale (Wilkes 1992;  Lumpkin and Darden 1982), a uni-dimensional, all-positive seven-item instrument was adapted for use in the study.  Three hypotheses regarding the factor structure and internal reliability of the scale were empirically investigated.  Results showed statistically significant differences in the psychometrics of the scale when negative or double negative wording was added to scale items.  Managerial implications are discussed

    Short-line railroad managers discuss class I railroads

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    Managers/owners of short-line railroads were queried about three issues: (1) How would you describe your company’s business relationship with the Class I railroad(s) with which you interchange traffic; (2) Do you believe that mergers between Class I railroads have been good or bad for short-line railroads; and (3) Besides merger activity, what do you believe will be the most important trend for Class I railroads in the next 10 years

    The Argo Program : present and future

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    Author Posting. © The Oceanography Society, 2017. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 30, no. 2 (2017): 18–28, doi:10.5670/oceanog.2017.213.The Argo Program has revolutionized large-scale physical oceanography through its contributions to basic research, national and international climate assessment, education, and ocean state estimation and forecasting. This article discusses the present status of Argo and enhancements that are underway. Extensions of the array into seasonally ice-covered regions and marginal seas as well as increased numbers of floats along the equator and around western boundary current extensions have been proposed. In addition, conventional Argo floats, with their 2,000 m sampling limit, currently observe only the upper half of the open ocean volume. Recent advances in profiling float technology and in the accuracy and stability of float-mounted conductivity-temperature-depth sensors make it practical to obtain measurements to 6,000 m. The Deep Argo array will help observe and constrain the global budgets of heat content, freshwater, and steric sea level, as well as the full-depth ocean circulation. Finally, another extension to the Argo Program is the addition of a diverse set of chemical sensors to profiling floats in order to build a Biogeochemical-Argo array to understand the carbon cycle, the biological pump, and ocean acidification.S.R.J. was supported by US Argo Program through NOAA Grant NA14OAR4320158 (CINAR). D.R. and N.Z. were supported by the US Argo Program through NOAA Grant NA10OAR4310139 (CIMEC). S.C.R. was supported by the US Argo Program through NOAA Grants NAOAR4320063 and NA16OAR4310161 (JISAO). K.S.J. was supported by the David and Lucile Packard Foundation and by the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) Project funded by National Science Foundation, Division of Polar Programs (NSF PLR-1425989). G.C.J. is supported by the Ocean Observations and Monitoring Division, Climate Program Office, National Oceanic and Atmospheric Administration (NOAA), US Department of Commerce and NOAA Research
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