1,051 research outputs found

    Real Space Approach to CMB deboosting

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    The effect of our Galaxy's motion through the Cosmic Microwave Background rest frame, which aberrates and Doppler shifts incoming photons measured by current CMB experiments, has been shown to produce mode-mixing in the multipole space temperature coefficients. However, multipole space determinations are subject to many difficulties, and a real-space analysis can provide a straightforward alternative. In this work we describe a numerical method for removing Lorentz- boost effects from real-space temperature maps. We show that to deboost a map so that one can accurately extract the temperature power spectrum requires calculating the boost kernel at a finer pixelization than one might naively expect. In idealized cases that allow for easy comparison to analytic results, we have confirmed that there is indeed mode mixing among the spherical harmonic coefficients of the temperature. We find that using a boost kernel calculated at Nside=8192 leads to a 1% bias in the binned boosted power spectrum at l~2000, while individual Cls exhibit ~5% fluctuations around the binned average. However, this bias is dominated by pixelization effects and not the aberration and Doppler shift of CMB photons that causes the fluctuations. Performing analysis on maps with galactic cuts does not induce any additional error in the boosted, binned power spectra over the full sky analysis. For multipoles that are free of resolution effects, there is no detectable deviation between the binned boosted and unboosted spectra. This result arises because the power spectrum is a slowly varying function of and does not show that, in general, Lorentz boosts can be neglected for other cosmological quantities such as polarization maps or higher-point functions.Comment: 8 pages, submitted to MNRA

    Roots-eye view: using microdialysis and microCT to non-destructively map root nutrient depletion and accumulation zones

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    Improvement in fertiliser use efficiency is a key aspect for achieving sustainable agriculture in order to minimise costs, greenhouse gas emissions and pollution from nutrient runoff. To optimise root architecture for nutrient uptake and efficiency we need to understand what the roots encounter in their environment. Traditional methods of nutrient sampling such as salt extractions can only be done at the end of an experiment, are impractical for sampling locations precisely and give total nutrient values which can overestimate the nutrients available to the roots. In contrast, microdialysis provides a non-invasive, continuous method for sampling available nutrients in the soil. Here for the first time we have used microCT imaging to position microdialysis probes at known distances from the roots and then measured the available nitrate and ammonium. We found that nitrate accumulated close to roots while ammonium was depleted demonstrating that this combination of complementary techniques provides a unique ability to measure root-available nutrients non-destructively and in almost real-time

    Web log analysis panel

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    No Abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/61334/1/1450440124_ftp.pd

    Evaluation of excess 234Th activity in sediments as an indicator of food quality for deep-sea deposit feeders

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    Deep-sea deposit feeders selectively ingest large volumes of sediment. Knowledge of the nature of this selectivity will help to elucidate the limiting nutritional requirements and geochemical impacts of these abundant animals. Shallow-water and theoretical studies suggest that deep-sea deposit feeders should select particles rich in protein, bacterial biomass, and/or chloropigment concentrations. Recent studies indicate that deep-sea megafaunal deposit feeders exhibit strong gut enrichment of excess (xs) 234Th activity, even though 234Thxs lacks nutritional value. To explore the significance of selective ingestion of 234Thxs activity, we evaluated the correlations between 234Thxs activity and three potential tracers of deposit feeder food quality: chlorophyll a (chl a), enzymatically hydrolyzable amino acids (EHAA), and adenosine triphosphate (ATP). Surface sediments from three quiescent bathyal basins off Southern California (San Nicolas, Santa Catalina, and San Clemente) were collected by a multiple corer and analyzed for 234Thxs activity, chl a, EHAA, ATP, and total organic carbon and nitrogen. 234Thxs activity was positively correlated with chl a and phaeopigment concentrations and negatively correlated with EHAA concentrations. Excess 234Th was not linearly correlated with concentrations of ATP, organic carbon, or total nitrogen. The results suggest that deep-sea deposit feeders select sediments with high 234Thxs activity because it is associated with recently settled phytodetrital material. There is no evidence that this 234Thxs-rich material has particularly high concentrations of labile amino acids or microbial biomass. Phytodetrital material may be an important source of some other limiting nutrient to deep-sea deposit feeders, e.g., polyunsaturated fatty acids, labile organic carbon and/or vitamins

    The Effects of a Plyometric Training Program on Jump Performance in Collegiate Figure Skaters: A Pilot Study

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    International Journal of Exercise Science 9(2): 175-186, 2016. Plyometric training has been implemented to increase jump height in a variety of sports, but its effects have not been researched in figure skating. The purpose of this study was to determine the effects of a plyometric training program on on-ice and off-ice jump performance. Six collegiate figure skaters (19.8±1.2 years; 164.7±4.9 cm; 60.3±11.6 kg) completed a six-week sport-specific plyometric training program, consisting of low to moderate intensity plyometric exercises, while eight collegiate figure skaters (21.1±3.9 years; 162.6±6.0 cm; 60.4±6.1 kg) served as the control group. Significant increases were found for vertical jump height, standing long jump distance, (F = 31.0, p \u3c 0.001), and flight time (F = 11.6, p = 0.007). No significant differences were found for self-reported jump evaluation (p = 0.101). Six weeks of plyometric training improved both on-ice and off-ice jump performance in collegiate figure skaters, while short-term skating training alone resulted in decreases. These results indicate that figure skaters could participate in off-ice plyometric training

    From Russia with Love: Understanding the Russian Cyber Threat to U.S. Critical Infrastructure and What to Do about It

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    I. Introduction II. A Short History of Russian Hacking of U.S. Government Networks and Critical Infrastructure III. Unpacking the Ukraine Grid Hacks and Their Aftermath IV. Analyzing Policy Options to Help Promote the Resilience of U.S. Government Systems and Critical Infrastructure ... A. Contextualizing and Introducing Draft Version 1.1 of the NIST Cybersecurity Framework ... B. Operationalizing International Cybersecurity Norms on Critical Infrastructure ... C. Deterrence and a Path Forward ... 1. Publicize Benefits as Applied … 2. Publicize Exercise Results ... 3. Publicize Updates V. Conclusio

    Macromolecules in the Bayer Process

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    This is the publisher's version, also available electronically from http://www.degruyter.com/view/j/revce.2003.19.5/revce.2003.19.5.431/revce.2003.19.5.431.xml.See article for abstract
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