18,415 research outputs found

    Reliability of the Omron HBF-500 Body Composition Monitor

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    The Omron HBF-500 incorporates both hand-to-hand and foot-to-foot electrical impedance technology. At this time, the authors are not aware of any studies examining the consistency of this monitor. PURPOSE: To assess the reliability of the Omron HBF-500 body composition monitor. METHODS: Twelve men and six women signed an informed consent and participated in the study (32.4±8.7 years, 169.9±7.5 cm, 81.4±15.9 kg, 28.2±5.5 kg.m-2). Participants reported to the laboratory on three separate occasions separated by at least one day and within one week. Participants were asked to refrain from exercise and caffeine on the days of testing and, were asked to not eat a heavy meal three hours prior and to remain normally hydrated. For each trial, height was measured on a Seca 214 portable height rod (Hamburg, Germany) and weight on a Detecto DR 400 digital platform scale (Webb City, MO) without shoes or socks and with one layer of light clothing. Participants then had their body weight and body fat percent (BF%) assessed on the Omron HBF-500 body composition monitor. On the second day of testing, body BF% was also assessed using a Biodynamics 450 bioimpedance analyzer (Seattle, WA). RESULTS: There were no significant differences between the trials for weight assessed on the digital platform scale, F(2,17) = 1.2, p = 0.308, and on the Omron HBF-500, F(2,17) = 2.6, p = 0.086 (Table 1). There were also no significant differences between the trials for body fat assessed on the Omron F(2,17) = 1.0, p = 0.351. Reliability assessed with Cronbach’s alpha was high between the trials of each of the measures (Digital scale (kg), α = 0.999, Omron (kg), α = 0.999, Omron (BF%), α = 0.998). A dependent t-test indicated a significant difference in BF% between the Omron and Biodynamics analyzer (34.2±9.6 and 38.8±12.8, respectively), t(15) = -2.9, p = 0.011. Finally, dependent t-tests revealed body weight measured by the Omron was significantly greater than the Detecto scale in trial 2, t(17) = -6.9, p = 0.001, and in trial 3, t(17) = -7.9, p = 0.001. CONCLUSIONS: The Omron HBF-500 seems to consistently measure body weight and body composition. Although the HBF-500 can be questioned as an accurate measure of body composition, it seems to be a useful tool if one is interested in tracking changes in body weight and BF%

    Keck spectroscopy of z=1-3 ULIRGs from the Spitzer SWIRE survey

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    (Abridged) High-redshift ultra luminous infrared galaxies contribute the bulk of the cosmic IR background and are the best candidates for very massive galaxies in formation at z>1.5. We present Keck/LRIS optical spectroscopy of 35 z>1.4 luminous IR galaxies in the Spitzer Wide-area Infra-Red Extragalactic survey (SWIRE) northern fields (Lockman Hole, ELAIS-N1, ELAIS-N2). The primary targets belong to the ``IR-peak'' class of galaxies, having the 1.6 micron (restframe) stellar feature detected in the IRAC Spitzer channels.The spectral energy distributions of the main targets are thoroughly analyzed, by means of spectro-photometric synthesis and multi-component fits (stars + starburst dust + AGN torus). The IR-peak selection technique is confirmed to successfully select objects above z=1.4, though some of the observed sources lie at lower redshift than expected. Among the 16 galaxies with spectroscopic redshift, 62% host an AGN component, two thirds being type-1 and one third type-2 objects. The selection, limited to r'<24.5, is likely biased to optically-bright AGNs. The SEDs of non-AGN IR-peakers resemble those of starbursts (SFR=20-500 Msun/yr) hosted in massive (M>1e11 Msun) galaxies. The presence of an AGN component provides a plausible explanation for the spectroscopic/photometric redshift discrepancies, as the torus produces an apparent shift of the peak to longer wavelengths. These sources are analyzed in IRAC and optical-IR color spaces. In addition to the IR-peak galaxies, we present redshifts and spectral properties for 150 objects, out of a total of 301 sources on slits.Comment: Accepted for publications on Astronomy and Astrophysics (acceprance date March 8th, 2007). 33 pages. The quality of some figures have been degrade

    Chemical Abundances in Field Red Giants from High-Resolution H-Band Spectra using the APOGEE Spectral Linelist

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    High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory (KPNO) Fourier Transform Spectrometer (FTS), are analyzed to determine chemical abundances of 16 elements. The abundances were derived via spectrum synthesis using the detailed linelist prepared for the SDSS III Apache Point Galactic Evolution Experiment (APOGEE), which is a high-resolution near-infrared spectroscopic survey to derive detailed chemical abundance distributions and precise radial velocities for 100,000 red giants sampling all Galactic stellar populations. Measured chemical abundances include the cosmochemically important isotopes 12C, 13C, 14N, and 16O, along with Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu. A comparison of the abundances derived here with published values for these stars reveals consistent results to ~0.1 dex. The APOGEE spectral region and linelist is, thus, well-suited for probing both Galactic chemical evolution, as well as internal nucleosynthesis and mixing in populations of red giants using high-resolution spectroscopy.Comment: Accepted for publication in The Astrophysical Journal. 42 pages, 12 figure

    Accuracy of the Omron HBF-500 Body Composition Monitor

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    The Omron HBF-500 is a relatively new and inexpensive body composition monitor that incorporates both hand-to-hand and foot-to-foot electrical impedance technology. At this time, the authors are not aware of any studies examining the accuracy of this monitor. PURPOSE: To assess the accuracy of the Omron HBF-500 body composition monitor using the BOD POD as a criterion. METHODS: Sixteen men and 23 women signed an informed consent and participated in the study (22.7±3.7 years, 168.8±9.1 cm, 73.8±17.8 kg, 25.7±5.6 kg.m-2). Participants were asked to refrain from exercise and caffeine on the day of testing, and were asked not eat a heavy meal three hours prior and to remain normally hydrated. Participants removed all jewelry and garments down to tight fitting clothing (swim suits or running tights) and were assessed on the BOD POD and Omron according to manufacturer’s guidelines. RESULTS: The Omron HBF-500 significantly overestimated percent body fat (%BF) by 3.5% compared to the BOD POD (31.7±9.6% and 28.6±9.6%, respectively), t(38) = -6.05, p = 0.001. The Omron HBF-500 also measured weight significantly higher than the BODPOD (74.4±17.7kg and 73.8±17.8kg, respectively), t(38) = -11.2, p = 0.001. Finally, the Omron HBF-500 was significantly correlated with the BOD POD when assessing body fat, r = .93. CONCLUSIONS: Caution should be taken when using the Omron HBF-500 as a measure of body fat. Those who choose to use this instrument should be aware the 3.5% higher reading compared to the BOD POD

    the SDSS-III APOGEE Spectral Line List for H-Band Spectroscopy

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    We present the H-band spectral line lists adopted by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). The APOGEE line lists comprise astrophysical, theoretical, and laboratory sources from the literature, as well as newly evaluated astrophysical oscillator strengths and damping parameters. We discuss the construction of the APOGEE line list, which is one of the critical inputs for the APOGEE Stellar Parameters and Chemical Abundances Pipeline, and present three different versions that have been used at various stages of the project. The methodology for the newly calculated astrophysical line lists is reviewed. The largest of these three line lists contains 134,457 molecular and atomic transitions. In addition to the format adopted to store the data, the line lists are available in MOOG, Synspec, and Turbospectrum formats. The limitations of the line lists along with guidance for its use on different spectral types are discussed. We also present a list of H-band spectral features that are either poorly represented or completely missing in our line list. This list is based on the average of a large number of spectral fit residuals for APOGEE observations spanning a wide range of stellar parameters.Alfred P. Sloan FoundationNational Science FoundationU.S. Department of Energy Office of ScienceJanos Bolyai Research Scholarship of the Hungarian Academy of SciencesSpanish Ministry of Economy and Competitiveness AYA-2011-27754, AYA-2014-58082-PRSF 14-50-00043McDonald Observator

    Efficiency of scanning and attention to faces in infancy independently predict language development in a multiethnic and bilingual sample of 2-year-olds

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    Efficient visual exploration in infancy is essential for cognitive and language development. It allows infants to participate in social interactions by attending to faces and learning about objects of interest. Visual scanning of scenes depends on a number of factors and early differences in efficiency are likely contributing to differences in learning and language development during subsequent years. Predicting language development in diverse samples is particularly challenging, as additional multiple sources of variability affect infant performance. In this study we tested how the complexity of visual scanning in the presence or absence of a face at 6-7 months of age is related to language development at 2 years of age in a multi-ethnic and predominantly bilingual sample from diverse socio-economic backgrounds. We used Recurrence Quantification Analysis to measure the temporal and spatial distribution of fixations recurring in the same area of a visual scene. We found that in the absence of a face the temporal distribution of re-fixations on selected objects of interest (but not all) significantly predicted both receptive and expressive language scores, explaining 16 - 20% of the variance. Also, lower rate of re-fixations recurring in the presence of a face predicted higher receptive language scores, suggesting larger vocabulary in infants that effectively disengage from faces. Altogether, our results suggest that dynamic measures, which quantify the complexity of visual scanning can reliably and robustly predict language development in highly diverse samples. They suggest that selective attending to objects predicts language independently of attention to faces. As eye-tracking and language assessments were carried out in early intervention centres, our study demonstrates the utility of mobile eye-tracking setups for early detection of risk in attention and language development

    Map-making in small field modulated CMB polarisation experiments: approximating the maximum-likelihood method

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    Map-making presents a significant computational challenge to the next generation of kilopixel CMB polarisation experiments. Years worth of time ordered data (TOD) from thousands of detectors will need to be compressed into maps of the T, Q and U Stokes parameters. Fundamental to the science goal of these experiments, the observation of B-modes, is the ability to control noise and systematics. In this paper, we consider an alternative to the maximum-likelihood method, called destriping, where the noise is modelled as a set of discrete offset functions and then subtracted from the time-stream. We compare our destriping code (Descart: the DEStriping CARTographer) to a full maximum-likelihood map-maker, applying them to 200 Monte-Carlo simulations of time-ordered data from a ground based, partial-sky polarisation modulation experiment. In these simulations, the noise is dominated by either detector or atmospheric 1/f noise. Using prior information of the power spectrum of this noise, we produce destriped maps of T, Q and U which are negligibly different from optimal. The method does not filter the signal or bias the E or B-mode power spectra. Depending on the length of the destriping baseline, the method delivers between 5 and 22 times improvement in computation time over the maximum-likelihood algorithm. We find that, for the specific case of single detector maps, it is essential to destripe the atmospheric 1/f in order to detect B-modes, even though the Q and U signals are modulated by a half-wave plate spinning at 5-Hz.Comment: 18 pages, 17 figures, MNRAS accepted v2: content added (inc: table 2), typos correcte

    Baryon Number in Warped GUTs : Model Building and (Dark Matter Related) Phenomenology

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    In the past year, a new non-supersymmetric framework for electroweak symmetry breaking (with or without Higgs) involving SU(2)_L * SU(2)_R * U(1)_{B-L} in higher dimensional warped geometry has been suggested. In this work, we embed this gauge structure into a GUT such as SO(10) or Pati-Salam. We showed recently (in hep-ph/0403143) that in a warped GUT, a stable Kaluza-Klein fermion can arise as a consequence of imposing proton stability. Here, we specify a complete realistic model where this particle is a weakly interacting right-handed neutrino, and present a detailed study of this new dark matter candidate, providing relic density and detection predictions. We discuss phenomenological aspects associated with the existence of other light (<~ TeV) KK fermions (related to the neutrino), whose lightness is a direct consequence of the top quark's heaviness. The AdS/CFT interpretation of this construction is also presented. Most of our qualitative results do not depend on the nature of the breaking of the electroweak symmetry provided that it happens near the TeV brane.Comment: 61 pages, 12 figures; v2: minor changes; v3: Two additional diagrams in Fig. 10; a numerical factor corrected in section 16.1 (baryogenesis section), corresponding discussion slightly modified but qualitative results unchange
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