WorldWideScience

Sample records for compositions mass accuracy

  1. Relationship between Leg Mass, Leg Composition and Foot Velocity on Kicking Accuracy in Australian Football.

    Science.gov (United States)

    Hart, Nicolas H; Nimphius, Sophia; Spiteri, Tania; Cochrane, Jodie L; Newton, Robert U

    2016-06-01

    Kicking a ball accurately over a desired distance to an intended target is arguably the most important skill to acquire in Australian Football. Therefore, understanding the potential mechanisms which underpin kicking accuracy is warranted. The aim of this study was to examine the relationship between leg mass, leg composition and foot velocity on kicking accuracy in Australian Football. Thirty-one Australian Footballers (n = 31; age: 22.1 ± 2.8 years; height: 1.81 ± 0.07 m; weight: 85.1 ± 13.0 kg; BMI: 25.9 ± 3.2) each performed ten drop punt kicks over twenty metres to a player target. Athletes were separated into accurate (n = 15) and inaccurate (n = 16) kicking groups. Leg mass characteristics were assessed using whole body DXA scans. Foot velocity was determined using a ten-camera optoelectronic, three-dimensional motion capture system. Interactions between leg mass and foot velocity evident within accurate kickers only (r = -0.670 to -0.701). Relative lean mass was positively correlated with kicking accuracy (r = 0.631), while no relationship between foot velocity and kicking accuracy was evident in isolation (r = -0.047 to -0.083). Given the evident importance of lean mass, and its interaction with foot velocity for accurate kickers; future research should explore speed-accuracy, impulse-variability, limb co-ordination and foot-ball interaction constructs in kicking using controlled with-in subject studies to examine the effects of resistance training and skill acquisition programs on the development of kicking accuracy. Key pointsAccurate kickers expressed a very strong inverse relationship between leg mass and foot velocity. Inaccurate kickers were unable to replicate this, with greater volatility in their performance, indicating an ability of accurate kickers to mediate foot velocity to compensate for leg mass in order to deliver the ball over the required distance.Accurate kickers exhibited larger quantities of relative lean mass and lower quantities

  2. Relationship between Leg Mass, Leg Composition and Foot Velocity on Kicking Accuracy in Australian Football

    Directory of Open Access Journals (Sweden)

    Nicolas H. Hart, Jodie L. Cochrane, Tania Spiteri, Sophia Nimphius, Robert U. Newton

    2016-06-01

    Full Text Available Kicking a ball accurately over a desired distance to an intended target is arguably the most important skill to acquire in Australian Football. Therefore, understanding the potential mechanisms which underpin kicking accuracy is warranted. The aim of this study was to examine the relationship between leg mass, leg composition and foot velocity on kicking accuracy in Australian Football. Thirty-one Australian Footballers (n = 31; age: 22.1 ± 2.8 years; height: 1.81 ± 0.07 m; weight: 85.1 ± 13.0 kg; BMI: 25.9 ± 3.2 each performed ten drop punt kicks over twenty metres to a player target. Athletes were separated into accurate (n = 15 and inaccurate (n = 16 kicking groups. Leg mass characteristics were assessed using whole body DXA scans. Foot velocity was determined using a ten-camera optoelectronic, three-dimensional motion capture system. Interactions between leg mass and foot velocity evident within accurate kickers only (r = -0.670 to -0.701. Relative lean mass was positively correlated with kicking accuracy (r = 0.631, while no relationship between foot velocity and kicking accuracy was evident in isolation (r = -0.047 to -0.083. Given the evident importance of lean mass, and its interaction with foot velocity for accurate kickers; future research should explore speed-accuracy, impulse-variability, limb co-ordination and foot-ball interaction constructs in kicking using controlled with-in subject studies to examine the effects of resistance training and skill acquisition programs on the development of kicking accuracy.

  3. Metabolomic database annotations via query of elemental compositions: Mass accuracy is insufficient even at less than 1 ppm

    Directory of Open Access Journals (Sweden)

    Fiehn Oliver

    2006-04-01

    Full Text Available Abstract Background Metabolomic studies are targeted at identifying and quantifying all metabolites in a given biological context. Among the tools used for metabolomic research, mass spectrometry is one of the most powerful tools. However, metabolomics by mass spectrometry always reveals a high number of unknown compounds which complicate in depth mechanistic or biochemical understanding. In principle, mass spectrometry can be utilized within strategies of de novo structure elucidation of small molecules, starting with the computation of the elemental composition of an unknown metabolite using accurate masses with errors Results High mass accuracy (95% of false candidates. This orthogonal filter can condense several thousand candidates down to only a small number of molecular formulas. Example calculations for 10, 5, 3, 1 and 0.1 ppm mass accuracy are given. Corresponding software scripts can be downloaded from http://fiehnlab.ucdavis.edu. A comparison of eight chemical databases revealed that PubChem and the Dictionary of Natural Products can be recommended for automatic queries using molecular formulae. Conclusion More than 1.6 million molecular formulae in the range 0–500 Da were generated in an exhaustive manner under strict observation of mathematical and chemical rules. Assuming that ion species are fully resolved (either by chromatography or by high resolution mass spectrometry, we conclude that a mass spectrometer capable of 3 ppm mass accuracy and 2% error for isotopic abundance patterns outperforms mass spectrometers with less than 1 ppm mass accuracy or even hypothetical mass spectrometers with 0.1 ppm mass accuracy that do not include isotope information in the calculation of molecular formulae.

  4. Improving the accuracy of dynamic mass calculation

    Directory of Open Access Journals (Sweden)

    Oleksandr F. Dashchenko

    2015-06-01

    Full Text Available With the acceleration of goods transporting, cargo accounting plays an important role in today's global and complex environment. Weight is the most reliable indicator of the materials control. Unlike many other variables that can be measured indirectly, the weight can be measured directly and accurately. Using strain-gauge transducers, weight value can be obtained within a few milliseconds; such values correspond to the momentary load, which acts on the sensor. Determination of the weight of moving transport is only possible by appropriate processing of the sensor signal. The aim of the research is to develop a methodology for weighing freight rolling stock, which increases the accuracy of the measurement of dynamic mass, in particular wagon that moves. Apart from time-series methods, preliminary filtration for improving the accuracy of calculation is used. The results of the simulation are presented.

  5. Mass generation in composite models

    International Nuclear Information System (INIS)

    Peccei, R.D.

    1985-10-01

    I discuss aspects of composite models of quarks and leptons connected with the dynamics of how these fermions acquire mass. Several issues related to the protection mechanisms necessary to keep quarks and leptons light are illustrated by means of concrete examples and a critical overview of suggestions for family replications is given. Some old and new ideas of how one may actually be able to generate small quark and lepton masses are examined, along with some of the difficulties they encounter in practice. (orig.)

  6. High-accuracy mass spectrometry for fundamental studies.

    Science.gov (United States)

    Kluge, H-Jürgen

    2010-01-01

    Mass spectrometry for fundamental studies in metrology and atomic, nuclear and particle physics requires extreme sensitivity and efficiency as well as ultimate resolving power and accuracy. An overview will be given on the global status of high-accuracy mass spectrometry for fundamental physics and metrology. Three quite different examples of modern mass spectrometric experiments in physics are presented: (i) the retardation spectrometer KATRIN at the Forschungszentrum Karlsruhe, employing electrostatic filtering in combination with magnetic-adiabatic collimation-the biggest mass spectrometer for determining the smallest mass, i.e. the mass of the electron anti-neutrino, (ii) the Experimental Cooler-Storage Ring at GSI-a mass spectrometer of medium size, relative to other accelerators, for determining medium-heavy masses and (iii) the Penning trap facility, SHIPTRAP, at GSI-the smallest mass spectrometer for determining the heaviest masses, those of super-heavy elements. Finally, a short view into the future will address the GSI project HITRAP at GSI for fundamental studies with highly-charged ions.

  7. Mass composition analysis using elongation rate

    Energy Technology Data Exchange (ETDEWEB)

    Ochilo, Livingstone; Risse, Markus; Yushkov, Alexey [University of Siegen, Siegen (Germany)

    2015-07-01

    The all-particle cosmic ray energy spectrum has been observed to flatten at around 5.2 x 10{sup 18} eV where the spectral index changes from γ = 3.2 to γ = 2.6, a feature called the ''ankle'' of the spectrum. Cosmic rays with energy around the ankle and beyond, known as ultra-high energy cosmic rays (UHECR), have a very low flux and reconstruction of their properties from extensive air shower measurements is subject to uncertainties for instance from hadronic interaction models. Since the year 2004, the Pierre Auger Observatory has recorded a considerable number of UHECR events beyond the ankle. With the greatly improved statistics, the mass composition of the extreme end of the cosmic ray energy spectrum is now being investigated with improved accuracy. The measured composition of UHECR is an important parameter in validating the models used to explain their sources and acceleration mechanisms. In this study, we perform a mass composition analysis using elongation rate (the rate of change of the depth of shower maximum with energy), measured by the fluorescence detector of the Pierre Auger Observatory. The advantage of this approach is a weak dependence of the results on the choice of the hadronic interaction models.

  8. COMPOSITION OF CORONAL MASS EJECTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Zurbuchen, T. H.; Weberg, M.; Lepri, S. T. [Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI (United States); Von Steiger, R. [International Space Science Institute, Bern (Switzerland); Mewaldt, R. A. [California Institute of Technology, Pasadena, CA (United States); Antiochos, S. K. [Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD (United States)

    2016-07-20

    We analyze the physical origin of plasmas that are ejected from the solar corona. To address this issue, we perform a comprehensive analysis of the elemental composition of interplanetary coronal mass ejections (ICMEs) using recently released elemental composition data for Fe, Mg, Si, S, C, N, Ne, and He as compared to O and H. We find that ICMEs exhibit a systematic abundance increase of elements with first ionization potential (FIP) < 10 eV, as well as a significant increase of Ne as compared to quasi-stationary solar wind. ICME plasmas have a stronger FIP effect than slow wind, which indicates either that an FIP process is active during the ICME ejection or that a different type of solar plasma is injected into ICMEs. The observed FIP fractionation is largest during times when the Fe ionic charge states are elevated above Q {sub Fe} > 12.0. For ICMEs with elevated charge states, the FIP effect is enhanced by 70% over that of the slow wind. We argue that the compositionally hot parts of ICMEs are active region loops that do not normally have access to the heliosphere through the processes that give rise to solar wind. We also discuss the implications of this result for solar energetic particles accelerated during solar eruptions and for the origin of the slow wind itself.

  9. Anisotropic dynamic mass density for fluidsolid composites

    KAUST Repository

    Wu, Ying; Mei, Jun; Sheng, Ping

    2012-01-01

    By taking the low frequency limit of multiple-scattering theory, we obtain the dynamic effective mass density of fluidsolid composites with a two-dimensional rectangular lattice structure. The anisotropic mass density can be described by an angle

  10. Precision and accuracy of β gauge for aerosol mass determinations

    International Nuclear Information System (INIS)

    Courtney, W.J.; Shaw, R.W.; Dzabay, T.G.

    1982-01-01

    Results of an experimental determination of the precision and the accuracy of a β-ray attenuation method for measurement of aerosol mass are presented. The instrumental precision for a short-term experiment was 25 μg for a 6.5-cm 2 deposit collected on approximately 1 mg/cm 2 Teflon filters; for a longer-term experiment the precision was 27 μg. The precision of the gravimetric determinations of aerosol deposits was 22 μg for Teflon filters weighed to 1 μg. Filter reorientation and air density changes that were able adversely to affect the β-ray attenuation results are discussed. β-ray attenuation results are in good agreement with gravimetric measurements on the same filter-collected aerosols. Using dichotomous samplers in Durham, NC, we collected 136 aerosol samples on Teflon filters in two size ranges. A regression line was calculated implicitly assuming errors in both measurements of mass. The 90% confidence intervals lay within 21 μg of the regression line for mean fine fraction aerosol mass loadings of 536 μg and within 19 μg of the regression line for mean coarse fraction aerosol mass loadings of 349 μg. Any bias between gravimetric and β-gauge mass measurements was found to be less than 5%

  11. Accuracy of Body Mass Index Versus Lean Mass Index for Prediction of Sarcopenia in Older Women.

    Science.gov (United States)

    Benton, M J; Silva-Smith, A L

    2018-01-01

    We compared accuracy of body mass index (BMI) versus lean mass index (LMI) to predict sarcopenia in 58 community-dwelling women (74.1±0.9 years). Lean mass was measured with multi-frequency bioelectrical impedance analysis, and strength was measured with Arm Curl test, Chair Stand test, and handgrip dynamometry. Sarcopenia was defined as low LMI. When categorized by BMI, normal women had less absolute lean mass (37.6±1.0 vs. 42.6±0.9 kg; Plean mass (14.1±0.2 vs. 16.1±0.2 kg/m2; Plean mass (44.0±0.7 vs. 35.7±0.7 kg; Plean mass (16.2±0.2 vs. 13.8±0.2 kg/m2; Plean mass and strength. For clinical assessment, calculation of LMI rather than BMI is appropriate.

  12. High-accuracy mass determination of unstable nuclei with a Penning trap mass spectrometer

    CERN Multimedia

    2002-01-01

    The mass of a nucleus is its most fundamental property. A systematic study of nuclear masses as a function of neutron and proton number allows the observation of collective and single-particle effects in nuclear structure. Accurate mass data are the most basic test of nuclear models and are essential for their improvement. This is especially important for the astrophysical study of nuclear synthesis. In order to achieve the required high accuracy, the mass of ions captured in a Penning trap is determined via their cyclotron frequency $ \

  13. Analysis of Ion Composition Estimation Accuracy for Incoherent Scatter Radars

    Science.gov (United States)

    Martínez Ledesma, M.; Diaz, M. A.

    2017-12-01

    The Incoherent Scatter Radar (ISR) is one of the most powerful sounding methods developed to estimate the Ionosphere. This radar system determines the plasma parameters by sending powerful electromagnetic pulses to the Ionosphere and analyzing the received backscatter. This analysis provides information about parameters such as electron and ion temperatures, electron densities, ion composition, and ion drift velocities. Nevertheless in some cases the ISR analysis has ambiguities in the determination of the plasma characteristics. It is of particular relevance the ion composition and temperature ambiguity obtained between the F1 and the lower F2 layers. In this case very similar signals are obtained with different mixtures of molecular ions (NO2+ and O2+) and atomic oxygen ions (O+), and consequently it is not possible to completely discriminate between them. The most common solution to solve this problem is the use of empirical or theoretical models of the ionosphere in the fitting of ambiguous data. More recent works take use of parameters estimated from the Plasma Line band of the radar to reduce the number of parameters to determine. In this work we propose to determine the error estimation of the ion composition ambiguity when using Plasma Line electron density measurements. The sensibility of the ion composition estimation has been also calculated depending on the accuracy of the ionospheric model, showing that the correct estimation is highly dependent on the capacity of the model to approximate the real values. Monte Carlo simulations of data fitting at different signal to noise (SNR) ratios have been done to obtain valid and invalid estimation probability curves. This analysis provides a method to determine the probability of erroneous estimation for different signal fluctuations. Also it can be used as an empirical method to compare the efficiency of the different algorithms and methods on when solving the ion composition ambiguity.

  14. Accuracy of dual photon absorptiometry for assessment of bone mineral and body composition

    International Nuclear Information System (INIS)

    Aoki, Manabu; Iwamura, Akira; Goto, Eisuke; Mori, Yutaka; Kawakami, Kenji; Soshi, Shigeru

    1991-01-01

    Accuracy of bone mineral measurement by the dual photon absorptiometry (DPA) was studied in comparison to ashed bone mineral (ash) on the lumbar spine of 23 cada vars. There was a high correlation (r=0.896) between the value of DPA and ash weight. Bone mineral content in the radius by the single photon absorptiometry (SPA) did not correlate to bone mineral density (BMD) by DPA in the patients with hemodialysis. SPA may be less useful to assess BMD of the whole body. Fat mass and lean mass measured by DPA were well correlated to the value obtained by the electrical impedance method. Precision in measurement of fat mass and lean mass was also confirmed by the electrical impedance method. These results suggest that DPA has a high precision for measurements of the bone mineral and the body composition. (author)

  15. Improving mass measurement accuracy in mass spectrometry based proteomics by combining open source tools for chromatographic alignment and internal calibration.

    Science.gov (United States)

    Palmblad, Magnus; van der Burgt, Yuri E M; Dalebout, Hans; Derks, Rico J E; Schoenmaker, Bart; Deelder, André M

    2009-05-02

    Accurate mass determination enhances peptide identification in mass spectrometry based proteomics. We here describe the combination of two previously published open source software tools to improve mass measurement accuracy in Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). The first program, msalign, aligns one MS/MS dataset with one FTICRMS dataset. The second software, recal2, uses peptides identified from the MS/MS data for automated internal calibration of the FTICR spectra, resulting in sub-ppm mass measurement errors.

  16. ON THE ACCURACY OF WEAK-LENSING CLUSTER MASS RECONSTRUCTIONS

    International Nuclear Information System (INIS)

    Becker, Matthew R.; Kravtsov, Andrey V.

    2011-01-01

    We study the bias and scatter in mass measurements of galaxy clusters resulting from fitting a spherically symmetric Navarro, Frenk, and White model to the reduced tangential shear profile measured in weak-lensing (WL) observations. The reduced shear profiles are generated for ∼10 4 cluster-sized halos formed in a ΛCDM cosmological N-body simulation of a 1 h -1 Gpc box. In agreement with previous studies, we find that the scatter in the WL masses derived using this fitting method has irreducible contributions from the triaxial shapes of cluster-sized halos and uncorrelated large-scale matter projections along the line of sight. Additionally, we find that correlated large-scale structure within several virial radii of clusters contributes a smaller, but nevertheless significant, amount to the scatter. The intrinsic scatter due to these physical sources is ∼20% for massive clusters and can be as high as ∼30% for group-sized systems. For current, ground-based observations, however, the total scatter should be dominated by shape noise from the background galaxies used to measure the shear. Importantly, we find that WL mass measurements can have a small, ∼5%-10%, but non-negligible amount of bias. Given that WL measurements of cluster masses are a powerful way to calibrate cluster mass-observable relations for precision cosmological constraints, we strongly emphasize that a robust calibration of the bias requires detailed simulations that include more observational effects than we consider here. Such a calibration exercise needs to be carried out for each specific WL mass estimation method, as the details of the method determine in part the expected scatter and bias. We present an iterative method for estimating mass M 500c that can eliminate the bias for analyses of ground-based data.

  17. Improved mass resolution and mass accuracy in TOF-SIMS spectra and images using argon gas cluster ion beams.

    Science.gov (United States)

    Shon, Hyun Kyong; Yoon, Sohee; Moon, Jeong Hee; Lee, Tae Geol

    2016-06-09

    The popularity of argon gas cluster ion beams (Ar-GCIB) as primary ion beams in time-of-flight secondary ion mass spectrometry (TOF-SIMS) has increased because the molecular ions of large organic- and biomolecules can be detected with less damage to the sample surfaces. However, Ar-GCIB is limited by poor mass resolution as well as poor mass accuracy. The inferior quality of the mass resolution in a TOF-SIMS spectrum obtained by using Ar-GCIB compared to the one obtained by a bismuth liquid metal cluster ion beam and others makes it difficult to identify unknown peaks because of the mass interference from the neighboring peaks. However, in this study, the authors demonstrate improved mass resolution in TOF-SIMS using Ar-GCIB through the delayed extraction of secondary ions, a method typically used in TOF mass spectrometry to increase mass resolution. As for poor mass accuracy, although mass calibration using internal peaks with low mass such as hydrogen and carbon is a common approach in TOF-SIMS, it is unsuited to the present study because of the disappearance of the low-mass peaks in the delayed extraction mode. To resolve this issue, external mass calibration, another regularly used method in TOF-MS, was adapted to enhance mass accuracy in the spectrum and image generated by TOF-SIMS using Ar-GCIB in the delayed extraction mode. By producing spectra analyses of a peptide mixture and bovine serum albumin protein digested with trypsin, along with image analyses of rat brain samples, the authors demonstrate for the first time the enhancement of mass resolution and mass accuracy for the purpose of analyzing large biomolecules in TOF-SIMS using Ar-GCIB through the use of delayed extraction and external mass calibration.

  18. Molecular Isotopic Distribution Analysis (MIDAs) with adjustable mass accuracy.

    Science.gov (United States)

    Alves, Gelio; Ogurtsov, Aleksey Y; Yu, Yi-Kuo

    2014-01-01

    In this paper, we present Molecular Isotopic Distribution Analysis (MIDAs), a new software tool designed to compute molecular isotopic distributions with adjustable accuracies. MIDAs offers two algorithms, one polynomial-based and one Fourier-transform-based, both of which compute molecular isotopic distributions accurately and efficiently. The polynomial-based algorithm contains few novel aspects, whereas the Fourier-transform-based algorithm consists mainly of improvements to other existing Fourier-transform-based algorithms. We have benchmarked the performance of the two algorithms implemented in MIDAs with that of eight software packages (BRAIN, Emass, Mercury, Mercury5, NeutronCluster, Qmass, JFC, IC) using a consensus set of benchmark molecules. Under the proposed evaluation criteria, MIDAs's algorithms, JFC, and Emass compute with comparable accuracy the coarse-grained (low-resolution) isotopic distributions and are more accurate than the other software packages. For fine-grained isotopic distributions, we compared IC, MIDAs's polynomial algorithm, and MIDAs's Fourier transform algorithm. Among the three, IC and MIDAs's polynomial algorithm compute isotopic distributions that better resemble their corresponding exact fine-grained (high-resolution) isotopic distributions. MIDAs can be accessed freely through a user-friendly web-interface at http://www.ncbi.nlm.nih.gov/CBBresearch/Yu/midas/index.html.

  19. Anisotropic dynamic mass density for fluidsolid composites

    KAUST Repository

    Wu, Ying

    2012-10-01

    By taking the low frequency limit of multiple-scattering theory, we obtain the dynamic effective mass density of fluidsolid composites with a two-dimensional rectangular lattice structure. The anisotropic mass density can be described by an angle-dependent dipole solution, to the leading-order of solid concentration. The angular dependence vanishes for the square lattice, but at high solid concentrations there is a structure-dependent factor that contributes to the leading-order solution. In all cases, Woods formula is found to be accurately valid for the effective bulk modulus, independent of the structures. Numerical evaluations from the solutions are shown to be in excellent agreement with finite-element simulations. © 2012 Elsevier B.V.

  20. Changes in Kicking Pattern: Effect of Experience, Speed, Accuracy, and Effective Striking Mass

    Science.gov (United States)

    Southard, Dan L.

    2014-01-01

    Purpose: The purposes of this study were to: (a) examine the effect of experience and goal constraints (speed, accuracy) on kicking patterns; (b) determine if effective striking mass was independent of ankle velocity at impact; and (c) determine the accuracy of kicks relative to independent factors. Method: Twenty participants were recruited to…

  1. A simple algorithm improves mass accuracy to 50-100 ppm for delayed extraction linear MALDI-TOF mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hack, Christopher A.; Benner, W. Henry

    2001-10-31

    A simple mathematical technique for improving mass calibration accuracy of linear delayed extraction matrix assisted laser desorption ionization time-of-flight mass spectrometry (DE MALDI-TOF MS) spectra is presented. The method involves fitting a parabola to a plot of Dm vs. mass data where Dm is the difference between the theoretical mass of calibrants and the mass obtained from a linear relationship between the square root of m/z and ion time of flight. The quadratic equation that describes the parabola is then used to correct the mass of unknowns by subtracting the deviation predicted by the quadratic equation from measured data. By subtracting the value of the parabola at each mass from the calibrated data, the accuracy of mass data points can be improved by factors of 10 or more. This method produces highly similar results whether or not initial ion velocity is accounted for in the calibration equation; consequently, there is no need to depend on that uncertain parameter when using the quadratic correction. This method can be used to correct the internally calibrated masses of protein digest peaks. The effect of nitrocellulose as a matrix additive is also briefly discussed, and it is shown that using nitrocellulose as an additive to a CHCA matrix does not significantly change initial ion velocity but does change the average position of ions relative to the sample electrode at the instant the extraction voltage is applied.

  2. Effect of Lamina Thickness of Prepreg on the Surface Accuracy of Carbon Fiber Composite Space Mirrors

    Science.gov (United States)

    Yang, Zhiyong; Tang, Zhanwen; Xie, Yongjie; Shi, Hanqiao; Zhang, Boming; Guo, Hongjun

    2018-02-01

    Composite space mirror can completely replicate the high-precision surface of mould by replication process, but the actual surface accuracy of the replication composite mirror always decreases. Lamina thickness of prepreg affects the layers and layup sequence of composite space mirror, and which would affect surface accuracy of space mirror. In our research, two groups of contrasting cases through finite element analyses (FEA) and comparative experiments were studied; the effect of different lamina thicknesses of prepreg and corresponding lay-up sequences was focused as well. We describe a special analysis model, validated process and result analysis. The simulated and measured surface figures both get the same conclusion. Reducing lamina thickness of prepreg used in replicating composite space mirror is propitious to optimal design of layup sequence for fabricating composite mirror, and could improve its surface accuracy.

  3. Comparison of Diagnostic Accuracy of Breast Masses Using Digitized Images Versus Screen-Film Mammography

    International Nuclear Information System (INIS)

    Zhigang Liang; Xiangying Du; Jiabin Liu; Xinyu Yao; Yanhui Yang; Kuncheng Li

    2008-01-01

    Background: Medical film digitizers play an important transitory role as digital-analogue bridges in radiology. Digitized mammograms require evaluation of performance to assure medical image quality. Purpose: To compare the diagnostic accuracy in the interpretation of breast masses using original screen-film mammograms versus digitized images. Material and Methods: A total of 72 female patients between 55 and 81 years of age suspected of having breast cancer were selected by two non-observing radiologists. Of these, 31 cases were benign lesions and 41 cases were cancer. The mammography films were digitized using a laser film digitizer. Three radiologists, each with more than 10 years of experience in mammography, interpreted the screen-film mammograms and digitized images respectively. The time interval was 4 weeks. A four-point malignancy scale was used, with 1 defined as definitely not malignant, 2 as probably not malignant, 3 as probably malignant, and 4 as definitely malignant. Receiver operating characteristic (Roc) curves, sensitivity, and specificity were compared. Results: The average area-under-the-curve (Az) value of the original screen-film mammograms was 0.921, and the average Az value of the digitized images was 0.859. This difference was not statistically significant (P=0.131). The detection specificity of extremely dense breasts was lower than that for other breast compositions for both digitized images and screen-film mammograms. No statistical significance in sensitivity and specificity was observed between digitized images and mammograms for each breast composition. Original screen-film mammograms were observed to perform better than digitized images. Conclusion: Digitized images with a spatial resolution of 175 μm can be used instead of screen-film mammograms in the diagnosis of breast cancer

  4. Dynamic Modeling Accuracy Dependence on Errors in Sensor Measurements, Mass Properties, and Aircraft Geometry

    Science.gov (United States)

    Grauer, Jared A.; Morelli, Eugene A.

    2013-01-01

    A nonlinear simulation of the NASA Generic Transport Model was used to investigate the effects of errors in sensor measurements, mass properties, and aircraft geometry on the accuracy of dynamic models identified from flight data. Measurements from a typical system identification maneuver were systematically and progressively deteriorated and then used to estimate stability and control derivatives within a Monte Carlo analysis. Based on the results, recommendations were provided for maximum allowable errors in sensor measurements, mass properties, and aircraft geometry to achieve desired levels of dynamic modeling accuracy. Results using other flight conditions, parameter estimation methods, and a full-scale F-16 nonlinear aircraft simulation were compared with these recommendations.

  5. Influence of Layup Sequence on the Surface Accuracy of Carbon Fiber Composite Space Mirrors

    Science.gov (United States)

    Yang, Zhiyong; Liu, Qingnian; Zhang, Boming; Xu, Liang; Tang, Zhanwen; Xie, Yongjie

    2018-04-01

    Layup sequence is directly related to stiffness and deformation resistance of the composite space mirror, and error caused by layup sequence can affect the surface precision of composite mirrors evidently. Variation of layup sequence with the same total thickness of composite space mirror changes surface form of the composite mirror, which is the focus of our study. In our research, the influence of varied quasi-isotropic stacking sequences and random angular deviation on the surface accuracy of composite space mirrors was investigated through finite element analyses (FEA). We established a simulation model for the studied concave mirror with 500 mm diameter, essential factors of layup sequences and random angular deviations on different plies were discussed. Five guiding findings were described in this study. Increasing total plies, optimizing stacking sequence and keeping consistency of ply alignment in ply placement are effective to improve surface accuracy of composite mirror.

  6. Analysis of the plasmodium falciparum proteome by high-accuracy mass spectrometry

    DEFF Research Database (Denmark)

    Lasonder, Edwin; Ishihama, Yasushi; Andersen, Jens S

    2002-01-01

    -accuracy (average deviation less than 0.02 Da at 1,000 Da) mass spectrometric proteome analysis of selected stages of the human malaria parasite Plasmodium falciparum. The analysis revealed 1,289 proteins of which 714 proteins were identified in asexual blood stages, 931 in gametocytes and 645 in gametes. The last...

  7. An algorithm to correct saturated mass spectrometry ion abundances for enhanced quantitation and mass accuracy in omic studies

    Energy Technology Data Exchange (ETDEWEB)

    Bilbao, Aivett; Gibbons, Bryson C.; Slysz, Gordon W.; Crowell, Kevin L.; Monroe, Matthew E.; Ibrahim, Yehia M.; Smith, Richard D.; Payne, Samuel H.; Baker, Erin S.

    2018-04-01

    The mass accuracy and peak intensity of ions detected by mass spectrometry (MS) measurements are essential to facilitate compound identification and quantitation. However, high concentration species can easily cause problems if their ion intensities reach beyond the limits of the detection system, leading to distorted and non-ideal detector response (e.g. saturation), and largely precluding the calculation of accurate m/z and intensity values. Here we present an open source computational method to correct peaks above a defined intensity (saturated) threshold determined by the MS instrumentation such as the analog-to-digital converters or time-to-digital converters used in conjunction with time-of-flight MS. In this method, the isotopic envelope for each observed ion above the saturation threshold is compared to its expected theoretical isotopic distribution. The most intense isotopic peak for which saturation does not occur is then utilized to re-calculate the precursor m/z and correct the intensity, resulting in both higher mass accuracy and greater dynamic range. The benefits of this approach were evaluated with proteomic and lipidomic datasets of varying complexities. After correcting the high concentration species, reduced mass errors and enhanced dynamic range were observed for both simple and complex omic samples. Specifically, the mass error dropped by more than 50% in most cases with highly saturated species and dynamic range increased by 1-2 orders of magnitude for peptides in a blood serum sample.

  8. Soft Tissue Masses in the Extremities: The Accuracy of an Ultrasonographic Diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    An, Ji Young; Park, So Young; Park, Ji Seon; Jin, Wook; Ryu, Kyung Nam [Kyung Hee University Medical Center, Seoul (Korea, Republic of)

    2011-09-15

    We wanted to retrospectively determine the accuracy of an ultrasonographic diagnosis of superficial soft tissue masses in the extremities by using the histologic results as the reference standard. From January 2005 to June 2010, 154 patients with soft tissue masses in the extremities and who underwent ultrasonographic evaluation followed by biopsy or resection were retrospectively evaluated. The ultrasonographic and histologic diagnoses of the soft tissue masses were lipoma, ganglion cyst, hemangioma, neurogenic tumor, giant cell tumor of the tendon sheath, epidermoid cyst, fibroma, glomus tumor, Baker's cyst and neurofibromatosis. Out of 154 patients, 114 (74%) patients showed concordance between the histologic diagnosis and the ultrasonographic diagnosis, and the remaining 40 (26%) patients did not. The diagnostic accuracy of each soft tissue mass was 95% for lipoma, 83% for ganglion cyst, 75% for hemangioma, 72% for neurogenic tumor, 50% for giant cell tumor of the tendon sheath, 43% for epidermoid cyst, 33% for fibroma and 100% each for glomus tumor, fibromatosis and Baker's cyst. Aside from these tumors, there were also sarcoma, malignant melanoma, elastofibroma, Kimura disease and pilomatricoma. Among the cases that showed discordance between the histologic diagnosis and the ultrasonographic diagnosis, three of them were notable; pilomatricoma being misdiagnosed as dermatofibroma protuberans, angiolipoma being misdiagnosed as vascular leiomyoma and malignant fibrous histiocytoma being misdiagnosed as a malignant soft tissue mass. The accuracy of an ultrasonographic diagnosis for soft tissue masses in the extremities varies greatly according to each type of mass. Lipoma, ganglion cyst, hemangioma, glomus tumor, neurogenic tumor and Baker's cyst showed a relatively high rate of concordance between the ultrasonographic diagnosis and the histologic diagnosis, but epidermoid cyst and fibroma showed a relatively lower rate of concordance

  9. Thermal ionization mass spectrometry (TIMS) of actinides: Pushing the limits of accuracy and detection

    Energy Technology Data Exchange (ETDEWEB)

    Buerger, Stefan; Boulyga, Sergei; Cunningham, Alan; Klose, Dilani; Koepf, Andreas; Poths, Jane [Safeguards Analytical Laboratory, International Atomic Energy Agency, Vienna (Austria); Richter, Stephan [Institute for Reference Materials and Measurements, JRC-EU, Geel (Belgium)

    2010-07-01

    New method developments in multi-collector thermal ionization mass spectrometry (MC-TIMS) for actinide isotope ratio analysis to improve accuracy and limits of detection will be presented. With respect to limits of detection, results on improving work function using various carbon additives will be reviewed and presented as well as developments in cavity ion source (as compared to standard flat ribbon filament ion source) for femto- and attogram levels of uranium, plutonium, and americium. With respect to accuracy, results on isotope ratio measurements of isotopes of uranium (relative accuracy of 0.3% to 0.01%) are presented with an example being U-234-Th-230 age-dating (NBL CRM 112-A). In this context, the importance of traceability (to the S.I. units) and the use of (certified) reference materials are emphasized. The focus of this presentation is on applications to nuclear safeguards / forensics.

  10. Dependence of Dynamic Modeling Accuracy on Sensor Measurements, Mass Properties, and Aircraft Geometry

    Science.gov (United States)

    Grauer, Jared A.; Morelli, Eugene A.

    2013-01-01

    The NASA Generic Transport Model (GTM) nonlinear simulation was used to investigate the effects of errors in sensor measurements, mass properties, and aircraft geometry on the accuracy of identified parameters in mathematical models describing the flight dynamics and determined from flight data. Measurements from a typical flight condition and system identification maneuver were systematically and progressively deteriorated by introducing noise, resolution errors, and bias errors. The data were then used to estimate nondimensional stability and control derivatives within a Monte Carlo simulation. Based on these results, recommendations are provided for maximum allowable errors in sensor measurements, mass properties, and aircraft geometry to achieve desired levels of dynamic modeling accuracy. Results using additional flight conditions and parameter estimation methods, as well as a nonlinear flight simulation of the General Dynamics F-16 aircraft, were compared with these recommendations

  11. Body Mass Index is a Poor Predictor of Bedside Appendix Ultrasound Success or Accuracy

    OpenAIRE

    Lam, Samuel H.F.; Kerwin, Christopher; Konicki, P. John; Goodwine, Diana; Lambert, Michael J.

    2016-01-01

    Introduction: The objective of this study was to determine whether there is a relationship between body mass index (BMI) and success or accuracy rate of beside ultrasound (BUS) for the diagnosis of appendicitis. Methods: Patients four years of age and older presenting to the emergency department with suspected appendicitis were eligible. Enrollment was by convenience sampling. After informed consent, BUS was performed by trained emergency physicians who had undergone a minimum of one-hour...

  12. Assessing the accuracy of body mass estimation equations from pelvic and femoral variables among modern British women of known mass.

    Science.gov (United States)

    Young, Mariel; Johannesdottir, Fjola; Poole, Ken; Shaw, Colin; Stock, J T

    2018-02-01

    Femoral head diameter is commonly used to estimate body mass from the skeleton. The three most frequently employed methods, designed by Ruff, Grine, and McHenry, were developed using different populations to address different research questions. They were not specifically designed for application to female remains, and their accuracy for this purpose has rarely been assessed or compared in living populations. This study analyzes the accuracy of these methods using a sample of modern British women through the use of pelvic CT scans (n = 97) and corresponding information about the individuals' known height and weight. Results showed that all methods provided reasonably accurate body mass estimates (average percent prediction errors under 20%) for the normal weight and overweight subsamples, but were inaccurate for the obese and underweight subsamples (average percent prediction errors over 20%). When women of all body mass categories were combined, the methods provided reasonable estimates (average percent prediction errors between 16 and 18%). The results demonstrate that different methods provide more accurate results within specific body mass index (BMI) ranges. The McHenry Equation provided the most accurate estimation for women of small body size, while the original Ruff Equation is most likely to be accurate if the individual was obese or severely obese. The refined Ruff Equation was the most accurate predictor of body mass on average for the entire sample, indicating that it should be utilized when there is no knowledge of the individual's body size or if the individual is assumed to be of a normal body size. The study also revealed a correlation between pubis length and body mass, and an equation for body mass estimation using pubis length was accurate in a dummy sample, suggesting that pubis length can also be used to acquire reliable body mass estimates. This has implications for how we interpret body mass in fossil hominins and has particular relevance

  13. Diagnostic Accuracy of Dynamic Contrast Enhanced Magnetic Resonance Imaging in Characterizing Lung Masses

    Science.gov (United States)

    Inan, Nagihan; Arslan, Arzu; Donmez, Muhammed; Sarisoy, Hasan Tahsin

    2016-01-01

    Background Imaging plays a critical role not only in the detection, but also in the characterization of lung masses as benign or malignant. Objectives To determine the diagnostic accuracy of dynamic magnetic resonance imaging (MRI) in the differential diagnosis of benign and malignant lung masses. Patients and Methods Ninety-four masses were included in this prospective study. Five dynamic series of T1-weighted spoiled gradient echo (FFE) images were obtained, followed by a T1-weighted FFE sequence in the late phase (5th minutes). Contrast enhancement patterns in the early (25th second) and late (5th minute) phase images were evaluated. For the quantitative evaluation, signal intensity (SI)-time curves were obtained and the maximum relative enhancement, wash-in rate, and time-to-peak enhancement of masses in both groups were calculated. Results The early phase contrast enhancement patterns were homogeneous in 78.2% of the benign masses, while heterogeneous in 74.4% of the malignant tumors. On the late phase images, 70.8% of the benign masses showed homogeneous enhancement, while most of the malignant masses showed heterogeneous enhancement (82.4%). During the first pass, the maximum relative enhancement and wash-in rate values of malignant masses were significantly higher than those of the benign masses (P = 0.03 and 0.04, respectively). The cutoff value at 15% yielded a sensitivity of 85.4%, specificity of 61.2%, and positive predictive value of 68.7% for the maximum relative enhancement. Conclusion Contrast enhancement patterns and SI-time curve analysis of MRI are helpful in the differential diagnosis of benign and malignant lung masses. PMID:27703654

  14. The Influence of Methods Massed Practice and Distributed Practice Model on The Speed and Accuracy of Service Tennis Courts

    OpenAIRE

    Desak Wiwin,; Edy Mintarto; Nurkholis Nurkholis

    2017-01-01

    The purpose of this study was to analyze about (1) the effect of the method massed practice against the speed and accuracy of service, (2) the effect of the method of distributed practice against the speed and accuracy of service and (3) the influence of methods of massed practice and distributed practice against the speed and accuracy of service. This type of research used in this research is quantitative with quasiexperimental methods. The research design uses a non-randomized control group...

  15. Diagnostic accuracy of percutaneous cytodiagnosis of hepatic masses, by ultrasound guided fine needle aspiration cytology

    International Nuclear Information System (INIS)

    Asghar, F.; Riaz, S.

    2010-01-01

    Objective: To evaluate the diagnostic accuracy, usefulness and limitations of ultrasound guided FNAC of hepatic masses. Design: Cross - sectional analytical (comparative study). Place and Duration: Department of histopathology, Sheikh Zayed Hospital, Lahore. Study period 1 year. Material and Methods: A total of 32 patients with solitary or multiple hepatic masses underwent FNAC from March 1999 to March 2000. Adequate aspirates were obtained in all these cases. Smears were stained with May-Grunwald Giemsa, Haematoxylin and Eosin and Papanicolaou stain. Needle biopsies from the same cases were also obtained and processed. These were stained with routine Haematoxylin and Eosin staining. The blood clots obtained during FNAC were fixed in 10% neu-tral buffered formalin. The histopathology of these blood clots was used for cases whose needle core biopsy was not available. The screened FNAC smears were divided into 3 categories i.e., benign (group - I), malignant (group - II), non-neoplastic / inflammatory lesions (including cysts and abscesses) (group - III). Results: Out of 32 cases, 6 were categorized as benign, 18 as malignant, and 8 as non-neoplastic inflammatory lesions. Three false negative diagnoses, including 1 for malignant tumour and 2 for benign tumours was obtained. There was 1 false positive diagnosis for malignancy. FNAC - histological correlation showed a 94.2% sensitivity and 92.3% diagnostic accuracy for malignant tumours, while benign tumours posed maximum diagnostic problems, giving a 66.67% sensitivity and 85.7% diagnostic accuracy. FNAC picked up correctly all the non-neoplastic lesions giving a 100% sensitivity and diagnostic accuracy. Conclusion: Majority of the malignant tumours can be categorized on FNAC, with a high degree of accuracy, while benign tumours should be subjected to biopsy, as there is a relatively greater possibility of false negative diagnosis. (author)

  16. Improved mass-measurement accuracy using a PNB Load Cell Scale

    International Nuclear Information System (INIS)

    Suda, S.; Pontius, P.; Schoonover, R.

    1981-08-01

    The PNB Load Cell Scale is a Preloaded, Narrow-Band calibration mass comparator. It consists of (1) a frame and servo-mechanism that maintains a preload tension on the load cell until the load, an unknown mass, is sensed, and (2) a null-balance digital instrument that suppresses the cell response associated with the preload, thereby improving the precision and accuracy of the measurements. Ideally, the objects used to set the preload should be replica mass standards that closely approximate the density and mass of the unknowns. The advantages of the PNB scale are an expanded output signal over the range of interest which increases both the sensitivity and resolution, and minimizes the transient effects associated with loading of load cells. An area of immediate and practical application of this technique to nuclear material safeguards is the weighing of UF 6 cyliners where in-house mass standards are currently available and where the mass values are typically assigned on the basis of comparison weighings. Several prototypical versions of the PNB scale have been assembled at the US National Bureau of Standards. A description of the instrumentation, principles of measurements, and applications are presented in this paper

  17. High mass accuracy and high mass resolving power FT-ICR secondary ion mass spectrometry for biological tissue imaging

    NARCIS (Netherlands)

    Smith, D.F.; Kiss, A.; Leach, F.E.; Robinson, E.W.; Paša-Tolić, L.; Heeren, R.M.A.

    2013-01-01

    Biological tissue imaging by secondary ion mass spectrometry has seen rapid development with the commercial availability of polyatomic primary ion sources. Endogenous lipids and other small bio-molecules can now be routinely mapped on the sub-micrometer scale. Such experiments are typically

  18. Body Mass Index is a Poor Predictor of Bedside Appendix Ultrasound Success or Accuracy

    Science.gov (United States)

    Lam, Samuel H.F.; Kerwin, Christopher; Konicki, P. John; Goodwine, Diana; Lambert, Michael J.

    2016-01-01

    Introduction The objective of this study was to determine whether there is a relationship between body mass index (BMI) and success or accuracy rate of beside ultrasound (BUS) for the diagnosis of appendicitis. Methods Patients four years of age and older presenting to the emergency department with suspected appendicitis were eligible. Enrollment was by convenience sampling. After informed consent, BUS was performed by trained emergency physicians who had undergone a minimum of one-hour didactic training on the use of BUS to diagnose appendicitis. We ascertained subject outcomes by a combination of medical record review and telephone follow up. Calculated BMI for adults and children were divided into four categories (underweight, normal, overweight, obese) according to Centers for Disease Control and Prevention classifications. Results A total of 125 subjects consented for the study, and 116 of them had adequate image data for final analysis. Seventy (60%) of the subjects were children. Prevalence of appendicitis was 39%. Fifty-two (45%) of the BUS studies were diagnostic (successful). Overall accuracy rate was 75%. Analysis by chi-square test or Mann-Whitney U test did not find any significant correlation between BMI category and BUS success. Similarly, there was no significant correlation between BMI category and BUS accuracy. The same conclusion was reached when children and adults were analyzed separately, or when subjects were dichotomized into underweight/normal and overweight/obese categories. Conclusion BMI category alone is a poor predictor of appendix BUS success or accuracy. PMID:27429696

  19. MALDI FTICR IMS of Intact Proteins: Using Mass Accuracy to Link Protein Images with Proteomics Data

    Science.gov (United States)

    Spraggins, Jeffrey M.; Rizzo, David G.; Moore, Jessica L.; Rose, Kristie L.; Hammer, Neal D.; Skaar, Eric P.; Caprioli, Richard M.

    2015-06-01

    MALDI imaging mass spectrometry is a highly sensitive and selective tool used to visualize biomolecules in tissue. However, identification of detected proteins remains a difficult task. Indirect identification strategies have been limited by insufficient mass accuracy to confidently link ion images to proteomics data. Here, we demonstrate the capabilities of MALDI FTICR MS for imaging intact proteins. MALDI FTICR IMS provides an unprecedented combination of mass resolving power (~75,000 at m/z 5000) and accuracy (differentiate a series of oxidation products of S100A8 ( m/z 10,164.03, -2.1ppm), a subunit of the heterodimer calprotectin, in kidney tissue from mice infected with Staphylococcus aureus. S100A8 - M37O/C42O3 ( m/z 10228.00, -2.6ppm) was found to co-localize with bacterial microcolonies at the center of infectious foci. The ability of MALDI FTICR IMS to distinguish S100A8 modifications is critical to understanding calprotectin's roll in nutritional immunity.

  20. Extermination Of Uranium Isotopes Composition Using A Micro Computer With An IEEE-488 Interface For Mass Spectrometer Analysis

    International Nuclear Information System (INIS)

    Prajitno; Taftazani, Agus; Yusuf

    1996-01-01

    A mass spectrometry method can be used to make qualitative or quantitative analysis. For qualitative analysis, identification of unknown materials by a Mass Spectrometer requires definite assignment of mass number to peak on chart. In quantitative analysis, a mass spectrometer is used to determine isotope composition material in the sample. Analysis system of a Mass Spectrometer possession of PPNY-BATAN based on comparison ion current intensity which enter the collector, and have been used to analyse isotope composition. Calculation of isotope composition have been manually done. To increase the performance and to avoid manual data processing, a micro computer and IEEE-488 interface have been installed, also software packaged has been made. So that the determination of the isotope composition of material in the sample will be faster and more efficient. Tile accuracy of analysis using this program on sample standard U 3 O 8 NBS 010 is between 93,87% - 99,98%

  1. Accuracy of Body Mass Index-defined Obesity Status in US Firefighters

    OpenAIRE

    Jitnarin, Nattinee; Poston, Walker S.C.; Haddock, Christopher K.; Jahnke, Sara A.; Day, Rena S.

    2014-01-01

    Obesity is a significant problem affecting United States (US) firefighters. While body mass index (BMI) is widely used to diagnose obesity, its use for this occupational group has raised concerns about validity. We examined rates and types of misclassification of BMI-based obesity status compared to body fat percentage (BF%) and waist circumference (WC). Male career firefighters (N = 994) from 20 US departments completed all three body composition assessments. Mean BMI, BF%, and WC were 29 kg...

  2. Development of certified reference material of mineral composition of natural water designed to control of turbidity measurement accuracy

    Directory of Open Access Journals (Sweden)

    Liudmila I. Gorjaeva

    2017-01-01

    Full Text Available Introduction. The results of development of a certified reference material (CRM of mineral composition of natural water are presented. A solution prepared from the material of the CRM specimen imitates mineral composition of natural surface water. The certified values are mass fractions of nitrate ions, chloride ions, fluoride ions, and total iron and turbidity according to formazine scale. Materials and methods. The certified values of mass concentrations of the components were determined using calculated experimental evaluation procedure;the certified turbidity value was determinedusing the certified turbidimetric method. Results. The relative expanded uncertainty (k = 2 of the certified turbidity values does not exceed 5 %, the same value for mass concentrationsis not more than 3.5 %. Relative standard uncertainty from heterogeneity does not exceed 1.0 %. The shelf life of the developed CRM is set to 3 years. Discussion and conclusion. Developed CRM was registered in the State Register of CRM's as GSO 10815-2016. The CRM is designed to control the accuracy of results of the certified characteristics measurements, including proficiency testing of laboratories using interlaboratory comparative tests. The CRM can be used for validation of measurement procedures.

  3. Effects of Different Compression Techniques on Diagnostic Accuracies of Breast Masses on Digitized Mammograms

    International Nuclear Information System (INIS)

    Zhigang Liang; Xiangying Du; Jiabin Liu; Yanhui Yang; Dongdong Rong; Xinyu Y ao; Kuncheng Li

    2008-01-01

    Background: The JPEG 2000 compression technique has recently been introduced into the medical imaging field. It is critical to understand the effects of this technique on the detection of breast masses on digitized images by human observers. Purpose: To evaluate whether lossless and lossy techniques affect the diagnostic results of malignant and benign breast masses on digitized mammograms. Material and Methods: A total of 90 screen-film mammograms including craniocaudal and lateral views obtained from 45 patients were selected by two non-observing radiologists. Of these, 22 cases were benign lesions and 23 cases were malignant. The mammographic films were digitized by a laser film digitizer, and compressed to three levels (lossless and lossy 20:1 and 40:1) using the JPEG 2000 wavelet-based image compression algorithm. Four radiologists with 10-12 years' experience in mammography interpreted the original and compressed images. The time interval was 3 weeks for each reading session. A five-point malignancy scale was used, with a score of 1 corresponding to definitely not a malignant mass, a score of 2 referring to not a malignant mass, a score of 3 meaning possibly a malignant mass, a score of 4 being probably a malignant mass, and a score of 5 interpreted as definitely a malignant mass. The radiologists' performance was evaluated using receiver operating characteristic analysis. Results: The average Az values for all radiologists decreased from 0.8933 for the original uncompressed images to 0.8299 for the images compressed at 40:1. This difference was not statistically significant. The detection accuracy of the original images was better than that of the compressed images, and the Az values decreased with increasing compression ratio. Conclusion: Digitized mammograms compressed at 40:1 could be used to substitute original images in the diagnosis of breast cancer

  4. The Influence of Methods Massed Practice and Distributed Practice Model on The Speed and Accuracy of Service Tennis Courts

    Directory of Open Access Journals (Sweden)

    Desak Wiwin,

    2017-06-01

    Full Text Available The purpose of this study was to analyze about (1 the effect of the method massed practice against the speed and accuracy of service, (2 the effect of the method of distributed practice against the speed and accuracy of service and (3 the influence of methods of massed practice and distributed practice against the speed and accuracy of service. This type of research used in this research is quantitative with quasiexperimental methods. The research design uses a non-randomized control group pretest posttest design, and data analysis using Manova. The process of data collection is done by testing the speed of service (dartfish and test accuracy (Hewitt during the pretest and posttest. The results of the study as follows: (1 there is a significant influence on the methods of massed practice to increase the speed and accuracy of service (2 there is a significant influence on the method of distributed practice to increase the speed and accuracy of service (3 There is no significant difference influence among methods massed ptactice practice and distributed to the speed and accuracy of service. Conclusions of this research is a method massed practice and distributed practice equally provide significant results but that gives the influence of better is method distributed practice to speed and accuracy of service.

  5. High Accuracy Mass Measurement of the Dripline Nuclides $^{12,14}$Be

    CERN Multimedia

    2002-01-01

    State-of-the art, three-body nuclear models that describe halo nuclides require the binding energy of the halo neutron(s) as a critical input parameter. In the case of $^{14}$Be, the uncertainty of this quantity is currently far too large (130 keV), inhibiting efforts at detailed theoretical description. A high accuracy, direct mass deterlnination of $^{14}$Be (as well as $^{12}$Be to obtain the two-neutron separation energy) is therefore required. The measurement can be performed with the MISTRAL spectrometer, which is presently the only possible solution due to required accuracy (10 keV) and short half-life (4.5 ms). Having achieved a 5 keV uncertainty for the mass of $^{11}$Li (8.6 ms), MISTRAL has proved the feasibility of such measurements. Since the current ISOLDE production rate of $^{14}$Be is only about 10/s, the installation of a beam cooler is underway in order to improve MISTRAL transmission. The projected improvement of an order of magnitude (in each transverse direction) will make this measureme...

  6. Effect of the trapped mass and its composition on the heat transfer in the compression cycle of a reciprocating engine

    International Nuclear Information System (INIS)

    Armas, Octavio; Rodriguez, Jose; Payri, Francisco; Martin, Jaime; Agudelo, John R.

    2005-01-01

    The use of the polytropic coefficient calculation during the compression process in the thermodynamic cycle of a reciprocating internal combustion engine is an interesting tool to minimize errors in the synchronization of pressure and volume signals, and to determine heat flux transferred to the cylinder walls. The accuracy of this calculation depends on the instantaneous values for pressure, volume, trapped mass and its composition, as well as on their variations. In this work the effect of the errors in blow-by, trapped mass and its composition have been studied in detail, specially the effect of errors in the composition estimation, owing to the use of exhaust gas recirculation in typical diesel engines

  7. Original Research Body Mass Index is a Poor Predictor of Bedside Appendix Ultrasound Success or Accuracy

    Directory of Open Access Journals (Sweden)

    Samuel H.F. Lam

    2016-06-01

    Full Text Available Introduction: The objective of this study was to determine whether there is a relationship between body mass index (BMI and success or accuracy rate of beside ultrasound (BUS for the diagnosis of appendicitis. Methods: Patients four years of age and older presenting to the emergency department with suspected appendicitis were eligible. Enrollment was by convenience sampling. After informed consent, BUS was performed by trained emergency physicians who had undergone a minimum of one-hour didactic training on the use of BUS to diagnose appendicitis. We ascertained subject outcomes by a combination of medical record review and telephone follow up. Calculated BMI for adults and children were divided into four categories (underweight, normal, overweight, obese according to Centers for Disease Control and Prevention classifications. Results: A total of 125 subjects consented for the study, and 116 of them had adequate image data for final analysis. Seventy (60% of the subjects were children. Prevalence of appendicitis was 39%. Fifty-two (45% of the BUS studies were diagnostic (successful. Overall accuracy rate was 75%. Analysis by chi-square test or Mann-Whitney U test did not find any significant correlation between BMI category and BUS success. Similarly, there was no significant correlation between BMI category and BUS accuracy. The same conclusion was reached when children and adults were analyzed separately, or when subjects were dichotomized into underweight/ normal and overweight/ obese categories. Conclusion: BMI category alone is a poor predictor of appendix BUS success or accuracy. [West J Emerg Med. 2016;17(4454-459.

  8. Novel fabrication techniques for low-mass composite structures in silicon particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, Neal, E-mail: neal.hartman@cern.ch; Silber, Joseph; Anderssen, Eric; Garcia-Sciveres, Maurice; Gilchriese, Murdock; Johnson, Thomas; Cepeda, Mario

    2013-12-21

    The structural design of silicon-based particle detectors is governed by competing demands of reducing mass while maximizing stability and accuracy. These demands can only be met by fiber reinforced composite laminates (CFRP). As detecting sensors and electronics become lower mass, the motivation to reduce structure as a proportion of overall mass pushes modern detector structures to the lower limits of composite ply thickness, while demanding maximum stiffness. However, classical approaches to composite laminate design require symmetric laminates and flat structures, in order to minimize warping during fabrication. This constraint of symmetry in laminate design, and a “flat plate” approach to fabrication, results in more massive structures. This study presents an approach to fabricating stable and accurate, geometrically complex composite structures by bonding warped, asymmetric, but ultra-thin component laminates together in an accurate tool, achieving final overall precision normally associated with planar structures. This technique has been used to fabricate a prototype “I-beam” that supports two layers of detecting elements, while being up to 20 times stiffer and up to 30% lower mass than comparable, independent planar structures (typically known as “staves”)

  9. Mining the Popular Culture: The Mass Media and Freshman Composition.

    Science.gov (United States)

    McRae, M. W.

    The study of mass media and popular culture in a composition class allows students and teachers together to develop a critical awareness of television and advertising. Jerzy Kosinski's book, "Being There," a novel about the impact of television, is a beginning point for the study of television. Using that book as if it were a collection of events,…

  10. Feed intake, live mass-gain, body composition and protein ...

    African Journals Online (AJOL)

    Feed intake, live mass-gain, body composition and protein deposition in pigs fed three protein levels. E.H. Kemm,* F.K. Siebrits, M.N. Ras and H.A. Badenhorst. Animal and Dairy Science Research Institute, Private Bag X2, Irene 1675, Republic of South Africa. A group of 82 genetically lean and 90 obese Landrace pigs was ...

  11. On the Tuning and the Mass of the Composite Higgs

    CERN Document Server

    Panico, Giuliano; Tesi, Andrea; Wulzer, Andrea

    2013-01-01

    We analyze quantitatively the tuning of composite Higgs models with partial compositeness and its interplay with the predicted Higgs mass. In this respect we identify three classes of models, characterized by different quantum numbers of the fermionic colored resonances associated with the top quark, the so-called top partners. The main result of this classification is that in all models with moderate tuning a light Higgs, of 125 GeV mass, requires the presence of light top partners, around 1 TeV. The minimal tuning is comparable to the one of the most attractive supersymmetric models in particular the ones realizing Natural SUSY. This gives further support to an extensive program of top partners searches at the LHC that can already probe the natural region of composite Higgs models.

  12. High Accuracy mass Measurement of the very Short-Lived Halo Nuclide $^{11}$Li

    CERN Multimedia

    Le scornet, G

    2002-01-01

    The archetypal halo nuclide $^{11}$Li has now attracted a wealth of experimental and theoretical attention. The most outstanding property of this nuclide, its extended radius that makes it as big as $^{48}$Ca, is highly dependent on the binding energy of the two neutrons forming the halo. New generation experiments using radioactive beams with elastic proton scattering, knock-out and transfer reactions, together with $\\textit{ab initio}$ calculations require the tightening of the constraint on the binding energy. Good metrology also requires confirmation of the sole existing precision result to guard against a possible systematic deviation (or mistake). We propose a high accuracy mass determintation of $^{11}$Li, a particularly challenging task due to its very short half-life of 8.6 ms, but one perfectly suiting the MISTRAL spectrometer, now commissioned at ISOLDE. We request 15 shifts of beam time.

  13. The accuracy of body mass prediction for elderly specimens: Implications for paleoanthropology and legal medicine.

    Science.gov (United States)

    Chevalier, Tony; Lefèvre, Philippe; Clarys, Jan Pieter; Beauthier, Jean-Pol

    2016-10-01

    Different practices in paleoanthropology and legal medicine raise questions concerning the robustness of body mass (BM) prediction. Integrating personal identification from body mass estimation with skeleton is not a classic approach in legal medicine. The originality of our study is the use of an elderly sample in order to push prediction methods to their limits and to discuss about implications in paleoanthropology and legal medicine. The aim is to observe the accuracy of BM prediction in relation to the body mass index (BMI, index of classification) using five femoral head (FH) methods and one shaft (FSH) method. The sample is composed of 41 dry femurs obtained from dissection where age (c. 82 years) and gender are known, and weight (c. 59.5 kg) and height are measured upon admission to the body leg service. We show that the estimation of the mean BM of the elderly sample is not significantly different to the real mean BM when the appropriate formula is used for the femoral head diameter. In fact, the best prediction is obtained with the McHenry formula (1992), which was based on a sample with an equivalent average mass to that of our sample. In comparison, external shaft diameters, which are known to be more influenced by mechanical stimuli than femoral head diameters, yield less satisfactory results with the McHenry formula (1992) for shaft diameters. Based on all the methods used and the distinctive selected sample, overestimation (always observed with the different femoral head methods) can be restricted to 1.1%. The observed overestimation with the shaft method can be restricted to 7%. However, the estimation of individual BM is much less reliable. The BMI has a strong impact on the accuracy of individual BM prediction, and is unquestionably more reliable for individuals with normal BMI (9.6% vs 16.7% for the best prediction error). In this case, the FH method is also the better predictive method but not if we integrate the total sample (i.e., the FSH

  14. Accuracy of Body Mass Index Cutoffs for Classifying Obesity in Chilean Children and Adolescents

    Directory of Open Access Journals (Sweden)

    Rossana Gómez-Campos

    2016-05-01

    Full Text Available Objective: To determine the accuracy of two international Body Mass Index (BMI cut-offs for classifying obesity compared to the percentage of fat mass (%FM assessed by Dual-Energy X-ray Absorptiometry (DXA in a Chilean sample of children and adolescents; Material and Methods: The subjects studied included 280 children and adolescents (125 girls and 155 boys aged 8 to 17 years. Weight and height were measured. The BMI was calculated. Two international references (IOFT and WHO were used as cut-off points. The %FM was assessed by DXA. The receiver operating characteristic (ROC curve was used to assess the performance of BMI in detecting obesity on the basis of %FM; Results: A high correlation was observed between the %FM measured by the DXA and the Z-scores of IOTF and WHO scores in the Chilean adolescents separated by sex (r = 0.78–0.80. Differences occurred in both references (IOFT and WHO in relation to the criteria (p < 0.001. Both references demonstrated a good ability to predict sensitivity (between 84% and 93% and specificity (between 83% and 88% in both sexes of children and adolescents; Conclusions: A high correlation was observed between the Z-score of the BMI with the percentage of fat determined by the DXA. Despite this, the classifications using the different BMI cut-off points showed discrepancies. This suggests that the cut-off points selected to predict obesity in this sample should be viewed with caution.

  15. On the accuracy of mass measurement for microlensing black holes as seen by Gaia and OGLE

    Science.gov (United States)

    Rybicki, Krzysztof A.; Wyrzykowski, Łukasz; Klencki, Jakub; de Bruijne, Jos; Belczyński, Krzysztof; Chruślińska, Martyna

    2018-05-01

    We investigate the impact of combining Gaia astrometry from space with precise, high cadence OGLE photometry from the ground. For the archival event OGLE3-ULENS-PAR-02, which is likely a black hole, we simulate a realistic astrometric time series of Gaia measurements and combine it with the real photometric data collected by the OGLE project. We predict that at the end of the nominal 5 yr of the Gaia mission, for the events brighter than G ≈ 15.5 mag at the baseline, caused by objects heavier than 10 M⊙, it will be possible to unambiguously derive masses of the lenses, with accuracy between a few and 15 per cent. We find that fainter events (G < 17.5) can still have their lens masses determined, provided that they are heavier than 30 M⊙. We estimate that the rate of astrometric microlensing events caused by the stellar-origin black holes is ≈ 4 × 10- 7 yr- 1, which implies, that after 5 yr of Gaia operation and ≈5 × 106 bright sources in Gaia, it will be possible to identify few such events in the Gaia final catalogues.

  16. Double Beta Decay and Neutrino Masses Accuracy of the Nuclear Matrix Elements

    International Nuclear Information System (INIS)

    Faessler, Amand

    2005-01-01

    The neutrinoless double beta decay is forbidden in the standard model of the electroweak and strong interaction but allowed in most Grand Unified Theories (GUT's). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass, the neutrinoless double beta decay is allowed. Apart of one claim that the neutrinoless double beta decay in 76 Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUT's and the minimal R-parity violating supersymmetric model. One further can give lower limits for the vector boson mediating mainly the right-handed weak interaction and the heavy mainly right-handed Majorana neutrino in left-right symmetric GUT's. For that one has to assume that the specific mechanism is the leading one for the neutrinoless double beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present contribution, one discusses the accuracy of the present status of calculating the nuclear matrix elements and the corresponding limits of GUT's and supersymmetric parameters

  17. Fast mass interdiffusion in ceria/alumina composite

    DEFF Research Database (Denmark)

    Teocoli, Francesca; Ni, De Wei; Sanna, Simone

    2015-01-01

    by such mass diffusion are low viscosity flows and high reactivity between phases, indicated by the formation of CeAlO3. This reaction is promoted by the high content of oxygen defects and the chemical reduction of Ce4+ cations to Ce3+ in CGO/Al2O3 composites under low temperature and low pO2. In this work...

  18. Probing the Composition, Assembly and Activity of Protein Molecular Machines using Native Mass Spectrometry

    NARCIS (Netherlands)

    van de Waterbeemd, M.J.

    2017-01-01

    Native mass spectrometry and mass spectrometry in general, are powerful analytical tools for studying proteins and protein complexes. Native mass spectrometry may provide accurate mass measurements of large macromolecular assemblies enabling the investigation of their composition and stoichiometry.

  19. Sample size planning for composite reliability coefficients: accuracy in parameter estimation via narrow confidence intervals.

    Science.gov (United States)

    Terry, Leann; Kelley, Ken

    2012-11-01

    Composite measures play an important role in psychology and related disciplines. Composite measures almost always have error. Correspondingly, it is important to understand the reliability of the scores from any particular composite measure. However, the point estimates of the reliability of composite measures are fallible and thus all such point estimates should be accompanied by a confidence interval. When confidence intervals are wide, there is much uncertainty in the population value of the reliability coefficient. Given the importance of reporting confidence intervals for estimates of reliability, coupled with the undesirability of wide confidence intervals, we develop methods that allow researchers to plan sample size in order to obtain narrow confidence intervals for population reliability coefficients. We first discuss composite reliability coefficients and then provide a discussion on confidence interval formation for the corresponding population value. Using the accuracy in parameter estimation approach, we develop two methods to obtain accurate estimates of reliability by planning sample size. The first method provides a way to plan sample size so that the expected confidence interval width for the population reliability coefficient is sufficiently narrow. The second method ensures that the confidence interval width will be sufficiently narrow with some desired degree of assurance (e.g., 99% assurance that the 95% confidence interval for the population reliability coefficient will be less than W units wide). The effectiveness of our methods was verified with Monte Carlo simulation studies. We demonstrate how to easily implement the methods with easy-to-use and freely available software. ©2011 The British Psychological Society.

  20. Neutrino mass from cosmology: impact of high-accuracy measurement of the Hubble constant

    Energy Technology Data Exchange (ETDEWEB)

    Sekiguchi, Toyokazu [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582 (Japan); Ichikawa, Kazuhide [Department of Micro Engineering, Kyoto University, Kyoto 606-8501 (Japan); Takahashi, Tomo [Department of Physics, Saga University, Saga 840-8502 (Japan); Greenhill, Lincoln, E-mail: sekiguti@icrr.u-tokyo.ac.jp, E-mail: kazuhide@me.kyoto-u.ac.jp, E-mail: tomot@cc.saga-u.ac.jp, E-mail: greenhill@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2010-03-01

    Non-zero neutrino mass would affect the evolution of the Universe in observable ways, and a strong constraint on the mass can be achieved using combinations of cosmological data sets. We focus on the power spectrum of cosmic microwave background (CMB) anisotropies, the Hubble constant H{sub 0}, and the length scale for baryon acoustic oscillations (BAO) to investigate the constraint on the neutrino mass, m{sub ν}. We analyze data from multiple existing CMB studies (WMAP5, ACBAR, CBI, BOOMERANG, and QUAD), recent measurement of H{sub 0} (SHOES), with about two times lower uncertainty (5 %) than previous estimates, and recent treatments of BAO from the Sloan Digital Sky Survey (SDSS). We obtained an upper limit of m{sub ν} < 0.2eV (95 % C.L.), for a flat ΛCDM model. This is a 40 % reduction in the limit derived from previous H{sub 0} estimates and one-third lower than can be achieved with extant CMB and BAO data. We also analyze the impact of smaller uncertainty on measurements of H{sub 0} as may be anticipated in the near term, in combination with CMB data from the Planck mission, and BAO data from the SDSS/BOSS program. We demonstrate the possibility of a 5σ detection for a fiducial neutrino mass of 0.1 eV or a 95 % upper limit of 0.04 eV for a fiducial of m{sub ν} = 0 eV. These constraints are about 50 % better than those achieved without external constraint. We further investigate the impact on modeling where the dark-energy equation of state is constant but not necessarily -1, or where a non-flat universe is allowed. In these cases, the next-generation accuracies of Planck, BOSS, and 1 % measurement of H{sub 0} would all be required to obtain the limit m{sub ν} < 0.05−0.06 eV (95 % C.L.) for the fiducial of m{sub ν} = 0 eV. The independence of systematics argues for pursuit of both BAO and H{sub 0} measurements.

  1. Accuracy of Plantar Electrodes Compared with Hand and Foot Electrodes in Fat-free-mass Measurement

    Directory of Open Access Journals (Sweden)

    Michel Y. Jaffrin

    2014-01-01

    Full Text Available This paper investigates the measurement of fat-free mass (FFM by bioimpedance using foot-to-foot impedancemeters (FFI with plantar electrodes measuring the foot-to-foot resistance R34 and hand-to-foot medical impedancemeters. FFM measurements were compared with corresponding data using Dual X-ray absorptiometry (DXA. Equations giving FFM were established using linear multiple regression on DXA data in a first group of 170 subjects. For validation, these equations were used on a second group of 86 subjects, and FFM were compared with DXA data; no significant difference was observed. The same protocol was repeated, but using electrodes on the right hand and foot in standing position to measure the hand to-foot resistance R13. Mean differences with DXA were higher for R13 than for R34. Effect of electrode size and feet position on resistance was also investigated. R34 decreased when electrode area increased or if feet were moved forward. It decreased if feet were moved backward. A proper configuration of contact electrodes can improve measurement accuracy and reproducibility of FFI.

  2. A high-resolution mass spectrometer to measure atmospheric ion composition

    Directory of Open Access Journals (Sweden)

    H. Junninen

    2010-08-01

    Full Text Available In this paper we present recent achievements on developing and testing a tool to detect the composition of ambient ions in the mass/charge range up to 2000 Th. The instrument is an Atmospheric Pressure Interface Time-of-Flight Mass Spectrometer (APi-TOF, Tofwerk AG. Its mass accuracy is better than 0.002%, and the mass resolving power is 3000 Th/Th. In the data analysis, a new efficient Matlab based set of programs (tofTools were developed, tested and used. The APi-TOF was tested both in laboratory conditions and applied to outdoor air sampling in Helsinki at the SMEAR III station. Transmission efficiency calibrations showed a throughput of 0.1–0.5% in the range 100–1300 Th for positive ions, and linearity over 3 orders of magnitude in concentration was determined. In the laboratory tests the APi-TOF detected sulphuric acid-ammonia clusters in high concentration from a nebulised sample illustrating the potential of the instrument in revealing the role of sulphuric acid clusters in atmospheric new particle formation. The APi-TOF features a high enough accuracy, resolution and sensitivity for the determination of the composition of atmospheric small ions although the total concentration of those ions is typically only 400–2000 cm−3. The atmospheric ions were identified based on their exact masses, utilizing Kendrick analysis and correlograms as well as narrowing down the potential candidates based on their proton affinities as well isotopic patterns. In Helsinki during day-time the main negative ambient small ions were inorganic acids and their clusters. The positive ions were more complex, the main compounds were (polyalkyl pyridines and – amines. The APi-TOF provides a near universal interface for atmospheric pressure sampling, and this key feature will be utilized in future laboratory and field studies.

  3. Accurate mass measurements of very short-lived nuclei. Prerequisites for high-accuracy investigations of superallowed β-decays

    International Nuclear Information System (INIS)

    Herfurth, F.; Kellerbauer, A.; Sauvan, E.; Ames, F.; Engels, O.; Audi, G.; Lunney, D.; Beck, D.; Blaum, K.; Kluge, H.J.; Scheidenberger, C.; Sikler, G.; Weber, C.; Bollen, G.; Schwarz, S.; Moore, R.B.; Oinonen, M.

    2002-01-01

    Mass measurements of 34 Ar, 73-78 Kr, and 74,76 Rb were performed with the Penning-trap mass spectrometer ISOLTRAP. Very accurate Q EC -values are needed for the investigations of the Ft-value of 0 + → 0 + nuclear β-decays used to test the standard model predictions for weak interactions. The necessary accuracy on the Q EC -value requires the mass of mother and daughter nuclei to be measured with δm/m ≤ 3 . 10 -8 . For most of the measured nuclides presented here this has been reached. The 34 Ar mass has been measured with a relative accuracy of 1.1 .10 -8 . The Q EC -value of the 34 Ar 0 + → 0 + decay can now be determined with an uncertainty of about 0.01%. Furthermore, 74 Rb is the shortest-lived nuclide ever investigated in a Penning trap. (orig.)

  4. Use of prediction equations to determine the accuracy of whole-body fat and fat-free mass and appendicular skeletal muscle mass measurements from a single abdominal image using computed tomography in advanced cancer patients.

    Science.gov (United States)

    Kilgour, Robert D; Cardiff, Katrina; Rosenthall, Leonard; Lucar, Enriqueta; Trutschnigg, Barbara; Vigano, Antonio

    2016-01-01

    Measurements of body composition using dual-energy X-ray absorptiometry (DXA) and single abdominal images from computed tomography (CT) in advanced cancer patients (ACP) have important diagnostic and prognostic value. The question arises as to whether CT scans can serve as surrogates for DXA in terms of whole-body fat-free mass (FFM), whole-body fat mass (FM), and appendicular skeletal muscle (ASM) mass. Predictive equations to estimate body composition for ACP from CT images have been proposed (Mourtzakis et al. 2008; Appl. Physiol. Nutr. Metabol. 33(5): 997-1006); however, these equations have yet to be validated in an independent cohort of ACP. Thus, this study evaluated the accuracy of these equations in estimating FFM, FM, and ASM mass using CT images at the level of the third lumbar vertebrae and compared these values with DXA measurements. FFM, FM, and ASM mass were estimated from the prediction equations proposed by Mourtzakis and colleagues (2008) using single abdominal CT images from 43 ACP and were compared with whole-body DXA scans using Spearman correlations and Bland-Altman analyses. Despite a moderate to high correlation between the actual (DXA) and predicted (CT) values for FM (rho = 0.93; p ≤ 0.001), FFM (rho = 0.78; p ≤ 0.001), and ASM mass (rho = 0.70; p ≤ 0.001), Bland-Altman analyses revealed large range-of-agreement differences between the 2 methods (29.39 kg for FFM, 15.47 kg for FM, and 3.99 kg for ASM mass). Based on the magnitude of these differences, we concluded that prediction equations using single abdominal CT images have poor accuracy, cannot be considered as surrogates for DXA, and may have limited clinical utility.

  5. Top and Higgs masses in a composite boson model

    International Nuclear Information System (INIS)

    Kahana, D.E.

    1993-01-01

    Recently Nambu as well as Bardeen, Hill and Linden have suggested replacing the Higgs mechanism with a dynamical symmetry breaking generated by four fermion interactions of the top quark. In fact the model for replacing the scalar sector is that of Nambu and Jona-Lasinio (NJL) and one recovers the Higgs as a tt composite. Earlier authors have also treated vector mesons as composites within the NJL framework, with perhaps the earliest suggestion being that of Bjorken for a composite photon. Here we attempt to generate the entire electroweak interaction from a specific current-current, baryon number conserving form of the four fermion interaction. The W, Z and Higgs boson appear as coherent composites of all fermions, quarks and lepton, and not just of the top quark. The four fermion interaction is assumed to be valid at some high mass scale μ, perhaps the low energy limit resulting by the elimination of non-fermionic degrees of freedom from a more basic theory. The cutoff Λ, necessary in the non-renormalizable NJL may be viewed then as the proper scale for this more basic theory

  6. Accuracy of Body Mass Index-defined Obesity Status in US Firefighters

    Directory of Open Access Journals (Sweden)

    Nattinee Jitnarin

    2014-09-01

    Full Text Available Obesity is a significant problem affecting United States (US firefighters. While body mass index (BMI is widely used to diagnose obesity, its use for this occupational group has raised concerns about validity. We examined rates and types of misclassification of BMI-based obesity status compared to body fat percentage (BF% and waist circumference (WC. Male career firefighters (N = 994 from 20 US departments completed all three body composition assessments. Mean BMI, BF%, and WC were 29 kg/m2, 23%, and 97 cm, respectively. Approximately 33% and 15% of BF%- and WC-defined obese participants were misclassified as non-obese (false negatives using BMI, while 8% and 9% of non-obese participants defined by BF% and WC standards were identified as obese (false positives using BMI. When stratified by race/ethnicity, Pacific Islanders showed high rates of false positive misclassification. Precision in obesity classification would be improved by using WC along with BMI to determine firefighters' weight status.

  7. The accuracy of fine-needle aspiration cytology for diagnosis of parotid gland masses: a clinicopathological study of 114 patients

    Directory of Open Access Journals (Sweden)

    Jens Kristjan GUDMUNDSSON

    Full Text Available ABSTRACT Objective Fine-needle aspiration cytology is a valuable method for preoperative assessment of head and neck tumors. However, its accuracy in detection of salivary gland masses is controversial compared with other methods. The aim of this work was to evaluate the effectiveness and accuracy of fine-needle aspiration cytology (FNAC in the diagnosis of parotid gland masses. Material and Methods Over a 10-year period, 126 parotid gland masses were resected. Retrospective chart reviews of 114 patients were performed. The results of FNAC and final histological diagnosis were compared and the accuracy of FNAC was determined. Results Final histological evaluation revealed 11 malignant tumors and 103 benign lesions. Pleomorphic adenoma was the most common neoplasm (63%, followed by Warthin’s tumor (17.5%. The sensitivity of FNAC in detecting malignant tumors was 73% and the specificity was 97%. Positive predictive value (PPV was 73% and negative predictive value (NPV was 97%. The overall accuracy of FNAC in detecting parotid masses was 95%. False-negative diagnosis was found in mucoepidermoid carcinoma, acinic cell carcinoma, and epithelial-myoepithelial carcinoma whereas there was false-positive diagnosis in cases of pleomorphic adenoma and normal parotid gland tissue. Conclusion FNAC is a reliable minimally invasive diagnostic method with a high sensitivity in diagnosis of lesions in parotid glands. The sensitivity of detection of malignant tumors in parotid glands was low due to the biopsy technique used, and depended on tumor location. Postoperative complications decreased after superficial parotidectomy.

  8. High-accuracy mass measurements of neutron-rich Kr isotopes

    CERN Document Server

    Delahaye, P; Blaum, K; Carrel, F; George, S; Herfurth, F; Herlert, A; Kellerbauer, A G; Kluge, H J; Lunney, D; Schweikhard, L; Yazidjian, C

    2006-01-01

    The atomic masses of the neutron-rich krypton isotopes 84,86-95Kr have been determined with the tandem Penning trap mass spectrometer ISOLTRAP with uncertainties ranging from 20 to 220 ppb. The masses of the short-lived isotopes 94Kr and 95Kr were measured for the first time. The masses of the radioactive nuclides 89Kr and 91Kr disagree by 4 and 6 standard deviations, respectively, from the present Atomic-Mass Evaluation database. The resulting modification of the mass surface with respect to the two-neutron separation energies as well as implications for mass models and stellar nucleosynthesis are discussed.

  9. Accuracy of specific BIVA for the assessment of body composition in the United States population.

    Science.gov (United States)

    Buffa, Roberto; Saragat, Bruno; Cabras, Stefano; Rinaldi, Andrea C; Marini, Elisabetta

    2013-01-01

    Bioelectrical impedance vector analysis (BIVA) is a technique for the assessment of hydration and nutritional status, used in the clinical practice. Specific BIVA is an analytical variant, recently proposed for the Italian elderly population, that adjusts bioelectrical values for body geometry. Evaluating the accuracy of specific BIVA in the adult U.S. population, compared to the 'classic' BIVA procedure, using DXA as the reference technique, in order to obtain an interpretative model of body composition. A cross-sectional sample of 1590 adult individuals (836 men and 754 women, 21-49 years old) derived from the NHANES 2003-2004 was considered. Classic and specific BIVA were applied. The sensitivity and specificity in recognizing individuals below the 5(th) and above the 95(th) percentiles of percent fat (FMDXA%) and extracellular/intracellular water (ECW/ICW) ratio were evaluated by receiver operating characteristic (ROC) curves. Classic and specific BIVA results were compared by a probit multiple-regression. Specific BIVA was significantly more accurate than classic BIVA in evaluating FMDXA% (ROC areas: 0.84-0.92 and 0.49-0.61 respectively; p = 0.002). The evaluation of ECW/ICW was accurate (ROC areas between 0.83 and 0.96) and similarly performed by the two procedures (p = 0.829). The accuracy of specific BIVA was similar in the two sexes (p = 0.144) and in FMDXA% and ECW/ICW (p = 0.869). Specific BIVA showed to be an accurate technique. The tolerance ellipses of specific BIVA can be used for evaluating FM% and ECW/ICW in the U.S. adult population.

  10. Accuracy of specific BIVA for the assessment of body composition in the United States population.

    Directory of Open Access Journals (Sweden)

    Roberto Buffa

    Full Text Available BACKGROUND: Bioelectrical impedance vector analysis (BIVA is a technique for the assessment of hydration and nutritional status, used in the clinical practice. Specific BIVA is an analytical variant, recently proposed for the Italian elderly population, that adjusts bioelectrical values for body geometry. OBJECTIVE: Evaluating the accuracy of specific BIVA in the adult U.S. population, compared to the 'classic' BIVA procedure, using DXA as the reference technique, in order to obtain an interpretative model of body composition. DESIGN: A cross-sectional sample of 1590 adult individuals (836 men and 754 women, 21-49 years old derived from the NHANES 2003-2004 was considered. Classic and specific BIVA were applied. The sensitivity and specificity in recognizing individuals below the 5(th and above the 95(th percentiles of percent fat (FMDXA% and extracellular/intracellular water (ECW/ICW ratio were evaluated by receiver operating characteristic (ROC curves. Classic and specific BIVA results were compared by a probit multiple-regression. RESULTS: Specific BIVA was significantly more accurate than classic BIVA in evaluating FMDXA% (ROC areas: 0.84-0.92 and 0.49-0.61 respectively; p = 0.002. The evaluation of ECW/ICW was accurate (ROC areas between 0.83 and 0.96 and similarly performed by the two procedures (p = 0.829. The accuracy of specific BIVA was similar in the two sexes (p = 0.144 and in FMDXA% and ECW/ICW (p = 0.869. CONCLUSIONS: Specific BIVA showed to be an accurate technique. The tolerance ellipses of specific BIVA can be used for evaluating FM% and ECW/ICW in the U.S. adult population.

  11. Application of round grating angle measurement composite error amendment in the online measurement accuracy improvement of large diameter

    Science.gov (United States)

    Wang, Biao; Yu, Xiaofen; Li, Qinzhao; Zheng, Yu

    2008-10-01

    The paper aiming at the influence factor of round grating dividing error, rolling-wheel produce eccentricity and surface shape errors provides an amendment method based on rolling-wheel to get the composite error model which includes all influence factors above, and then corrects the non-circle measurement angle error of the rolling-wheel. We make soft simulation verification and have experiment; the result indicates that the composite error amendment method can improve the diameter measurement accuracy with rolling-wheel theory. It has wide application prospect for the measurement accuracy higher than 5 μm/m.

  12. Accuracy of Bioelectrical Impedance Analysis in Estimated Longitudinal Fat-Free Mass Changes in Male Army Cadets.

    Science.gov (United States)

    Langer, Raquel D; Matias, Catarina N; Borges, Juliano H; Cirolini, Vagner X; Páscoa, Mauro A; Guerra-Júnior, Gil; Gonçalves, Ezequiel M

    2018-03-26

    Bioelectrical impedance analysis (BIA) is a practical and rapid method for making a longitudinal analysis of changes in body composition. However, most BIA validation studies have been performed in a clinical population and only at one moment, or point in time (cross-sectional study). The aim of this study is to investigate the accuracy of predictive equations based on BIA with regard to the changes in fat-free mass (FFM) in Brazilian male army cadets after 7 mo of military training. The values used were determined using dual-energy X-ray absorptiometry (DXA) as a reference method. The study included 310 male Brazilian Army cadets (aged 17-24 yr). FFM was measured using eight general predictive BIA equations, with one equation specifically applied to this population sample, and the values were compared with results obtained using DXA. The student's t-test, adjusted coefficient of determination (R2), standard error of estimation (SEE), Lin's approach, and the Bland-Altman test were used to determine the accuracy of the predictive BIA equations used to estimate FFM in this population and between the two moments (pre- and post-moment). The FFM measured using the nine predictive BIA equations, and determined using DXA at the post-moment, showed a significant increase when compared with the pre-moment (p FFM changes in the army cadets between the two moments in a very similar way to the reference method (DXA). However, only the one BIA equation specific to this population showed no significant differences in the FFM estimation between DXA at pre- and post-moment of military routine. All predictive BIA equations showed large limits of agreement using the Bland-Altman approach. The eight general predictive BIA equations used in this study were not found to be valid for analyzing the FFM changes in the Brazilian male army cadets, after a period of approximately 7 mo of military training. Although the BIA equation specific to this population is dependent on the amount of

  13. Influence of the velocity vector base relocation to the center of mass of the interrogation area on PIV accuracy

    Directory of Open Access Journals (Sweden)

    Kouba Jan

    2014-03-01

    Full Text Available This paper is aimed at modification of calculation algorithm used in data processing from PIV (Particle Image Velocimetry method. The modification of standard Multi-step correlation algorithm is based on imaging the centre of mass of the interrogation area to define the initial point of the respective vector, instead of the geometrical centre. This paper describes the principle of initial point-vector assignment, the corresponding data processing methodology including the test track analysis. Both approaches are compared within the framework of accuracy in the conclusion. The accuracy test is performed using synthetic and real data.

  14. Accuracy increasing in the nuclear-physical analysis of mineral raw materials of heterogeneous composition

    International Nuclear Information System (INIS)

    Pak, Yu.; Vdovkin, A.; Pak, D.

    2002-01-01

    the analysis of heterogeneous raw material by the gamma-albedo method it's necessary to optimize the primary gamma-radiation energy choose depending on the material composition of the raw material, its granulometric composition and to reach the maximal presentability of the analysis. For this a method has been suggested which allows to increase substantially the effective study surface without increasing the analyzed object size. The essence of the method consists in the rotation of the object around its axis relatively to the detector reciprocating parallel to the sample in the process of measuring. The optimal laws of the detector motion and the sample rotation provide for the equal presentability of each unit study surface. The experimental approving of the suggested method showed that the optimization of the methodical and geometrical control parameters in the dynamic measuring conditions allow to increase the accuracy of the analysis of disperse raw materials more that twice as large

  15. A convenient method for X-ray analysis in TEM that measures mass thickness and composition

    Science.gov (United States)

    Statham, P.; Sagar, J.; Holland, J.; Pinard, P.; Lozano-Perez, S.

    2018-01-01

    We consider a new approach for quantitative analysis in transmission electron microscopy (TEM) that offers the same convenience as single-standard quantitative analysis in scanning electron microscopy (SEM). Instead of a bulk standard, a thin film with known mass thickness is used as a reference. The procedure involves recording an X-ray spectrum from the reference film for each session of acquisitions on real specimens. There is no need to measure the beam current; the current only needs to be stable for the duration of the session. A new reference standard with a large (1 mm x 1 mm) area of uniform thickness of 100 nm silicon nitride is used to reveal regions of X-ray detector occlusion that would give misleading results for any X-ray method that measures thickness. Unlike previous methods, the new X-ray method does not require an accurate beam current monitor but delivers equivalent accuracy in mass thickness measurement. Quantitative compositional results are also automatically corrected for specimen self-absorption. The new method is tested using a wedge specimen of Inconel 600 that is used to calibrate the high angle angular dark field (HAADF) signal to provide a thickness reference and results are compared with electron energy-loss spectrometry (EELS) measurements. For the new X-ray method, element composition results are consistent with the expected composition for the alloy and the mass thickness measurement is shown to provide an accurate alternative to EELS for thickness determination in TEM without the uncertainty associated with mean free path estimates.

  16. Method for the elucidation of the elemental composition of low molecular mass chemicals using exact masses of product ions and neutral losses: application to environmental chemicals measured by liquid chromatography with hybrid quadrupole/time-of-flight mass spectrometry.

    Science.gov (United States)

    Suzuki, Shigeru; Ishii, Tetsuko; Yasuhara, Akio; Sakai, Shinichi

    2005-01-01

    A method for elucidating the elemental compositions of low molecular weight chemicals, based primarily on mass measurements made using liquid chromatography (LC) with time-of-flight mass spectrometry (TOFMS) and quadrupole/time-of-flight mass spectrometry (LC/QTOFMS), was developed and tested for 113 chemicals of environmental interest with molecular masses up to approximately 400 Da. As the algorithm incorporating the method is not affected by differences in the instrument used, or by the ionization method and other ionization conditions, the method is useful not only for LC/TOFMS, but also for all kinds of mass spectra measured with higher accuracy and precision (uncertainties of a few mDa) employing all ionization methods and on-line separation techniques. The method involves calculating candidate compositions for intact ionized molecules (ionized forms of the sample molecule that have lost or gained no more than a proton, i.e., [M+H](+) or [M-H](-)) as well as for fragment ions and corresponding neutral losses, and eliminating those atomic compositions for the molecules that are inconsistent with the corresponding candidate compositions of fragment ions and neutral losses. Candidate compositions were calculated for the measured masses of the intact ionized molecules and of the fragment ions and corresponding neutral losses, using mass uncertainties of 2 and 5 mDa, respectively. Compositions proposed for the ionized molecule that did not correspond to the sum of the compositions of a candidate fragment ion and its corresponding neutral loss were discarded. One, 2-5, 6-10, 11-20, and >20 candidate compositions were found for 65%, 39%, 1%, 1%, and 0%, respectively, for the 124 ionized molecules formed from the 113 chemicals tested (both positive and negative ions were obtained from 11 of the chemicals). However, no candidate composition was found for 2% of the test cases (i.e., 3 chemicals), for each of which the measured mass of one of the product ions was in

  17. Dissecting plasmodesmata molecular composition by mass spectrometry-based proteomics.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Maria Françoise Bayer

    2013-01-01

    Full Text Available In plants, the intercellular communication through the membranous channels called plasmodesmata (PD; singular plasmodesma plays pivotal roles in the orchestration of development, defence responses and viral propagation. PD are dynamic structures embedded in the plant cell wall that are defined by specialised domains of the endoplasmic reticulum and the plasma membrane. PD structure and unique functions are guaranteed by their particular molecular composition. Yet, up to recent years and despite numerous approaches such as mutant screens, immunolocalisation or screening of random cDNAs, only few PD proteins had been conclusively identified and characterised. A clear breakthrough in the search of PD constituents came from mass-spectrometry-based proteomic approaches coupled with subcellular fractionation strategies. Due to their position, firmly anchored in the extracellular matrix, PD are notoriously difficult to isolate for biochemical analysis. Proteomic-based approaches have therefore first relied on the use of cell wall fractions containing embedded PD then on free PD fractions whereby PD membranes were released from the walls by enzymatic degradation. To discriminate between likely contaminants and PD protein candidates, bioinformatics tools have often been used in combination with proteomic approaches. GFP fusion proteins of selected candidates have confirmed the PD association of several protein families. Here we review the accomplishments and limitations of the proteomic based strategies to unravel the functional and structural complexity of PD. We also discuss the role of the identified PD associated proteins.

  18. Dissecting plasmodesmata molecular composition by mass spectrometry-based proteomics.

    Science.gov (United States)

    Salmon, Magali S; Bayer, Emmanuelle M F

    2012-01-01

    In plants, the intercellular communication through the membranous channels called plasmodesmata (PD; singular plasmodesma) plays pivotal roles in the orchestration of development, defence responses, and viral propagation. PD are dynamic structures embedded in the plant cell wall that are defined by specialized domains of the endoplasmic reticulum (ER) and the plasma membrane (PM). PD structure and unique functions are guaranteed by their particular molecular composition. Yet, up to recent years and despite numerous approaches such as mutant screens, immunolocalization, or screening of random cDNAs, only few PD proteins had been conclusively identified and characterized. A clear breakthrough in the search of PD constituents came from mass-spectrometry-based proteomic approaches coupled with subcellular fractionation strategies. Due to their position, firmly anchored in the extracellular matrix, PD are notoriously difficult to isolate for biochemical analysis. Proteomic-based approaches have therefore first relied on the use of cell wall fractions containing embedded PD then on "free" PD fractions whereby PD membranes were released from the walls by enzymatic degradation. To discriminate between likely contaminants and PD protein candidates, bioinformatics tools have often been used in combination with proteomic approaches. GFP fusion proteins of selected candidates have confirmed the PD association of several protein families. Here we review the accomplishments and limitations of the proteomic-based strategies to unravel the functional and structural complexity of PD. We also discuss the role of the identified PD-associated proteins.

  19. Accuracy of some routine method used in clinical chemistry as judged by isotope dilution-mass spectrometry

    International Nuclear Information System (INIS)

    Bjoerkhem, I.; Bergman, A.; Falk, O.; Kallner, A.; Lantto, O.; Svensson, L.; Akerloef, E.; Blomstrand, R.

    1981-01-01

    Serum from patients was pooled, filtered, dispensed, and frozen. This pooled specimen was used for accuracy control in 64 participating laboratories in Sweden. Mean values (state-of-the-art values) were obtained for creatinine, cholesterol, glucose, urea, uric acid, and cortisol. These values were compared with values obtained with highly accurate reference methods based on isotope dilution-mass spectrometry. Differences were marked in the case of determination of creatinine and cortisol. Concerning the other components, the differences between the state-of-the-art value and the values obtained with the reference methods were negligible. Moreover, the glucose oxidase and the oxime methods for determination of glucose and urea were found to give significantly lower values than the hexokinase and urease methods, respectively. Researchers conclude that methods with a higher degree of accuracy are required for routine determination of creatinine and cortisol

  20. Mass Evolution of Mediterranean, Black, Red, and Caspian Seas from GRACE and Altimetry: Accuracy Assessment and Solution Calibration

    Science.gov (United States)

    Loomis, B. D.; Luthcke, S. B.

    2016-01-01

    We present new measurements of mass evolution for the Mediterranean, Black, Red, and Caspian Seas as determined by the NASA Goddard Space Flight Center (GSFC) GRACE time-variable global gravity mascon solutions. These new solutions are compared to sea surface altimetry measurements of sea level anomalies with steric corrections applied. To assess their accuracy, the GRACE and altimetry-derived solutions are applied to the set of forward models used by GSFC for processing the GRACE Level-1B datasets, with the resulting inter-satellite range acceleration residuals providing a useful metric for analyzing solution quality.

  1. Accuracy of immunoassay and mass spectrometry urinary free cortisol in the diagnosis of Cushing's syndrome.

    Science.gov (United States)

    Aranda, G; Careaga, M; Hanzu, F A; Patrascioiu, I; Ríos, P; Mora, M; Morales-Romero, B; Jiménez, W; Halperin, I; Casals, G

    2016-10-01

    Urinary free cortisol (UFC) determination by highly specific methods as mass spectrometry instead of commercially available antibody-based immunoassays is increasingly recommended. However, clinical comparisons of both analytical approaches in the screening of Cushing's syndrome (CS) are not available. The aim of this study was to evaluate the diagnostic value of mass spectrometry versus immunoassay measurements of 24 h-UFC in the screening of CS. Cross-sectional study of 33 histologically confirmed CS patients: 25 Cushing's disease, 5 adrenal CS and 3 ectopic CS; 92 non-CS patients; and 35 healthy controls. UFC by immunoassay (UFCxIA) and mass spectrometry (UFCxMS), urinary free cortisone (UFCo) and UFC:UFCo ratio were measured, together with creatinine-corrected values. Sensitivity, specificity, AUC and Landis and Koch concordance index were determined. AUC for UFCxIA and UFCxMS were 0.77 (CI 0.68-0.87) and 0.77 (CI 0.67-0.87) respectively, with a kappa coefficient 0.60 and strong Landis and Koch concordance index. The best calculated cutoff values were 359 nmol/24 h for UFCxIA (78 % sensitivity, 62 % specificity) and 258.1 nmol/24 h for UCFxMS (53 % sensitivity, 86 % specificity). The upper limit of UFCxIA and UCFxMS reference ranges were 344.7 and 169.5 nmol/24 h respectively. Sensitivity and specificity for CS diagnosis at these cutpoints were 84 and 56 % for UFCxIA and 81 and 54 % for UFCxMS. According to our data, both methods present a very similar diagnostic value. However, results suggest that lower cutoff points for mass spectrometry may be necessary in order to improve clinical sensitivity.

  2. Evaluate the accuracy of the numerical solution of hydrogeological problems of mass transfer

    Directory of Open Access Journals (Sweden)

    Yevhrashkina G.P.

    2014-12-01

    Full Text Available In the hydrogeological task on quantifying pollution of aquifers the error are starting add up with moment organization of regime observation network as a source of information on the pollution of groundwater in order to evaluate migration options for future prognosis calculations. Optimum element regime observation network should consist of three drill holes on the groundwater flow at equal distances from one another and transversely to the flow of the three drill holes, and at equal distances. If the target of observation drill holes coincides with the stream line on which will then be decided by direct migration task, the error will be minimal. The theoretical basis and results of numerical experiments to assess the accuracy of direct predictive tasks planned migration of groundwater in the area of full water saturation. For the vadose zone, we consider problems of vertical salt transport moisture. All studies were performed by comparing the results of fundamental and approximate solutions in a wide range of characteristics of the processes, which are discussed in relation to ecological and hydrogeological conditions of mining regions on the example of the Western Donbass.

  3. C-arm cone-beam CT virtual navigation-guided percutaneous mediastinal mass biopsy: Diagnostic accuracy and complications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyungjin [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Aerospace Medical Group, Air Force Education and Training Command, Jinju (Korea, Republic of); Park, Chang Min; Goo, Jin Mo [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of); Lee, Sang Min [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of)

    2015-12-15

    To assess the usefulness of C-arm cone-beam computed tomography (CBCT) virtual navigation-guided percutaneous mediastinal mass biopsy in terms of diagnostic accuracy and complication rates. Seventy-eight CBCT virtual navigation-guided percutaneous mediastinal mass biopsies were performed in 75 patients (M:F, 38:37; mean age, 48.55 ± 18.76 years). The procedural details, diagnostic sensitivity, specificity, accuracy and complication rate were investigated. Mean lesion size was 6.80 ± 3.08 cm, skin-to-target distance was 3.67 ± 1.80 cm, core needle biopsy rate was 96.2 % (75/78), needle indwelling time was 9.29 ± 4.34 min, total procedure time was 13.26 ± 5.29 min, number of biopsy specimens obtained was 3.13 ± 1.02, number of CBCTs performed was 3.03 ± 0.68, rate of lesion border discrimination from abutting mediastinal structures on CBCT was 26.9 % (21/78), technical success rate was 100 % (78/78), estimated effective dose was 5.33 ± 4.99 mSv, and the dose area product was 12,723.68 ± 10,665.74 mGy.cm{sup 2}. Among the 78 biopsies, 69 were malignant, 7 were benign and 2 were indeterminate. Diagnostic sensitivity, specificity and accuracy for the diagnosis of malignancies were 97.1 % (67/69), 100 % (7/7) and 97.4 % (74/76), respectively, with a complication rate of 3.85 % (3/78), all of which were small pneumothoraces. CBCT virtual navigation-guided biopsy is a highly accurate and safe procedure for the evaluation of mediastinal lesions. (orig.)

  4. Holistic Facial Composite Construction and Subsequent Lineup Identification Accuracy: Comparing Adults and Children.

    Science.gov (United States)

    Davis, Josh P; Thorniley, Sarah; Gibson, Stuart; Solomon, Chris

    2016-01-01

    When the police have no suspect, they may ask an eyewitness to construct a facial composite of that suspect from memory. Faces are primarily processed holistically, and recently developed computerized holistic facial composite systems (e.g., EFIT-V) have been designed to match these processes. The reported research compared children aged 6-11 years with adults on their ability to construct a recognizable EFIT-V composite. Adult constructor's EFIT-Vs received significantly higher composite-suspect likeness ratings from assessors than children's, although there were some notable exceptions. In comparison to adults, the child constructors also overestimated the composite-suspect likeness of their own EFIT-Vs. In a second phase, there were no differences between adult controls and constructors in correct identification rates from video lineups. However, correct suspect identification rates by child constructors were lower than those of child controls, suggesting that a child's memory for the suspect can be adversely influenced by composite construction. Nevertheless, all child constructors coped with the demands of the EFIT-V system, and the implications for research, theory, and the criminal justice system practice are discussed.

  5. Three-dimensional echocardiography: assessment of inter- and intra-operator variability and accuracy in the measurement of left ventricular cavity volume and myocardial mass

    International Nuclear Information System (INIS)

    Nadkarni, S.K.; Drangova, M.; Boughner, D.R.; Fenster, A.; Department of Medical Biophysics, Medical Sciences Building, University of Western Ontario, London, Ontario N6A 5C1

    2000-01-01

    Accurate left ventricular (LV) volume and mass estimation is a strong predictor of cardiovascular morbidity and mortality. We propose that our technique of 3D echocardiography provides an accurate quantification of LV volume and mass by the reconstruction of 2D images into 3D volumes, thus avoiding the need for geometric assumptions. We compared the accuracy and variability in LV volume and mass measurement using 3D echocardiography with 2D echocardiography, using in vitro studies. Six operators measured the LV volume and mass of seven porcine hearts, using both 3D and 2D techniques. Regression analysis was used to test the accuracy of results and an ANOVA test was used to compute variability in measurement. LV volume measurement accuracy was 9.8% (3D) and 18.4% (2D); LV mass measurement accuracy was 5% (3D) and 9.2% (2D). Variability in LV volume quantification with 3D echocardiography was %SEM inter = 13.5%, %SEM intra = 11.4%, and for 2D echocardiography was %SEM inter = 21.5%, %SEM intra = 19.1%. We derived an equation to predict uncertainty in measurement of LV volume and mass using 3D echocardiography, the results of which agreed with our experimental results to within 13%. 3D echocardiography provided twice the accuracy for LV volume and mass measurement and half the variability for LV volume measurement as compared with 2D echocardiography. (author)

  6. An application of a relational database system for high-throughput prediction of elemental compositions from accurate mass values.

    Science.gov (United States)

    Sakurai, Nozomu; Ara, Takeshi; Kanaya, Shigehiko; Nakamura, Yukiko; Iijima, Yoko; Enomoto, Mitsuo; Motegi, Takeshi; Aoki, Koh; Suzuki, Hideyuki; Shibata, Daisuke

    2013-01-15

    High-accuracy mass values detected by high-resolution mass spectrometry analysis enable prediction of elemental compositions, and thus are used for metabolite annotations in metabolomic studies. Here, we report an application of a relational database to significantly improve the rate of elemental composition predictions. By searching a database of pre-calculated elemental compositions with fixed kinds and numbers of atoms, the approach eliminates redundant evaluations of the same formula that occur in repeated calculations with other tools. When our approach is compared with HR2, which is one of the fastest tools available, our database search times were at least 109 times shorter than those of HR2. When a solid-state drive (SSD) was applied, the search time was 488 times shorter at 5 ppm mass tolerance and 1833 times at 0.1 ppm. Even if the search by HR2 was performed with 8 threads in a high-spec Windows 7 PC, the database search times were at least 26 and 115 times shorter without and with the SSD. These improvements were enhanced in a low spec Windows XP PC. We constructed a web service 'MFSearcher' to query the database in a RESTful manner. Available for free at http://webs2.kazusa.or.jp/mfsearcher. The web service is implemented in Java, MySQL, Apache and Tomcat, with all major browsers supported. sakurai@kazusa.or.jp Supplementary data are available at Bioinformatics online.

  7. Estimating Accuracy of Land-Cover Composition From Two-Stage Clustering Sampling

    Science.gov (United States)

    Land-cover maps are often used to compute land-cover composition (i.e., the proportion or percent of area covered by each class), for each unit in a spatial partition of the region mapped. We derive design-based estimators of mean deviation (MD), mean absolute deviation (MAD), ...

  8. Diagnostic accuracy of dynamic contrast-enhanced MR imaging of renal masses with rapid-acquisition spin-echo technique

    International Nuclear Information System (INIS)

    Eilenberg, S.S.; Lee, J.K.T.; Brown, J.J.; Heiken, J.P.; Mirowitz, S.A.

    1990-01-01

    This paper compares the diagnostic accuracy of Gd-DTPA-enhanced rapid-acquisition spin-echo (RASE) imaging with standard spin-echo techniques for detecting renal cysts and solid renal neoplasms. RASE imaging combines a short TR (275 msec)/short TE (10 msec), single excitation pulse sequence with half-Fourier data sampling. Eighteen patients with CT evidence of renal masses were first evaluated with standard T1-and T2-weighted SE sequences. Pre- and serial postcontrast (Cd-DTPA, 0.1 mmol./kg) RASE sequences were then performed during suspended respiration. A final set of postcontrast images was obtained with the standard T1-weighted SE sequence. Each set of MR images was first reviewed separately (ie, T1, T2, pre- and post-contrast RASE, etc)

  9. Spectroscopic characterization of galaxy clusters in RCS-1: spectroscopic confirmation, redshift accuracy, and dynamical mass-richness relation

    Science.gov (United States)

    Gilbank, David G.; Barrientos, L. Felipe; Ellingson, Erica; Blindert, Kris; Yee, H. K. C.; Anguita, T.; Gladders, M. D.; Hall, P. B.; Hertling, G.; Infante, L.; Yan, R.; Carrasco, M.; Garcia-Vergara, Cristina; Dawson, K. S.; Lidman, C.; Morokuma, T.

    2018-05-01

    We present follow-up spectroscopic observations of galaxy clusters from the first Red-sequence Cluster Survey (RCS-1). This work focuses on two samples, a lower redshift sample of ˜30 clusters ranging in redshift from z ˜ 0.2-0.6 observed with multiobject spectroscopy (MOS) on 4-6.5-m class telescopes and a z ˜ 1 sample of ˜10 clusters 8-m class telescope observations. We examine the detection efficiency and redshift accuracy of the now widely used red-sequence technique for selecting clusters via overdensities of red-sequence galaxies. Using both these data and extended samples including previously published RCS-1 spectroscopy and spectroscopic redshifts from SDSS, we find that the red-sequence redshift using simple two-filter cluster photometric redshifts is accurate to σz ≈ 0.035(1 + z) in RCS-1. This accuracy can potentially be improved with better survey photometric calibration. For the lower redshift sample, ˜5 per cent of clusters show some (minor) contamination from secondary systems with the same red-sequence intruding into the measurement aperture of the original cluster. At z ˜ 1, the rate rises to ˜20 per cent. Approximately ten per cent of projections are expected to be serious, where the two components contribute significant numbers of their red-sequence galaxies to another cluster. Finally, we present a preliminary study of the mass-richness calibration using velocity dispersions to probe the dynamical masses of the clusters. We find a relation broadly consistent with that seen in the local universe from the WINGS sample at z ˜ 0.05.

  10. Effective Mass and g Factor of Four-Flux-Quanta Composite Fermions

    International Nuclear Information System (INIS)

    Yeh, A.S.; Tsui, D.C.; Stormer, H.L.; Pfeiffer, L.N.; Baldwin, K.W.; West, K.W.; Stormer, H.L.; Tsui, D.C.

    1999-01-01

    We investigate the properties of composite fermions with four attached flux quanta through tilted-field experiments near Landau level filling factor ν=3/4 . The observed collapse of fractional quantum Hall gaps in the vicinity of this quarter-filling state can be comprehensively understood in terms of composite fermions with mass and spin. Remarkably, the effective mass and g factor of these four-flux-quanta composite fermions around ν=3/4 are very similar to those of two-flux-quanta composite fermions around ν=3/2 . copyright 1999 The American Physical Society

  11. Development of a portable mass spectrometric system for determination of isotopic composition of solid uranium samples using fluorine volatilization

    Science.gov (United States)

    Loge, G.

    1994-09-01

    Using hardware and materials supplied by LANL, a prototype quadrupole mass spectrometer system designed for portable field analysis of isotopic composition of solid uranium samples was assembled and tested. The system contained the capability for fluorine volatilization of solid uranium samples with gas introduction, which was successfully tested and demonstrated using 100 mg samples of U3O8. Determination of precision and accuracy for measuring isotopic composition was performed using isotopic standards. Use with soil samples containing uranium were also attempted. Silicates in the soil forming SiF4 were found to be a kinetic bottleneck to the formation of UF6. This could be avoided by performing some sort of chemical separation as a pre-treatment step, which was demonstrated using nitric acid.

  12. Radiative and semi-leptonic B-meson decay spectra: Sudakov resummation beyond logarithmic accuracy and the pole mass

    Science.gov (United States)

    Gardi, Einan

    2004-04-01

    The inclusive spectra of radiative and semi-leptonic B-meson decays near the endpoint is computed taking into account renormalons in the Sudakov exponent (Dressed Gluon Exponentiation). In this framework we demonstrate the factorization of decay spectra into hard, jet and soft functions and discuss the universality of the latter two. Going beyond perturbation theory the soft function, which we identify as the longitudinal momentum distribution in an on-shell b quark, is replaced by the b-quark distribution in the B meson. The two differ by power corrections. We show how the resummation of running-coupling effects can be used to perform consistent separation to power accuracy between perturbative and non-perturbative contributions. In particular, we prove that the leading infrared renormalon ambiguity in the Sudakov exponent cancels against the one associated with the definition of the pole mass. This cancellation allows us to identify the non-perturbative parameter that controls the shift of the perturbative spectrum in the heavy-quark limit as the mass difference between the meson and the quark.

  13. Feed intake, live mass-gain, body composition and protein ...

    African Journals Online (AJOL)

    Appropriate regression relationships were used to measure the effect of dietary protein level on the patterns of DE intake, daily gain and the deposition rates of protein (PDR) and fat (FDR) over the growth period 30-90 kg live mass. Dietary CP content had no significant effect on mean voluntary DE intakes and daily gains.

  14. Mass splittings within composite Goldstone supermultiplets from broken supersymmetry

    International Nuclear Information System (INIS)

    Clark, T.E.; Love, S.T.

    1985-01-01

    The supersymmetric (SUSY) Dashen formulas are modified to include effects of softly broken supersymmetry and are used to compute the mass splittings and differences in decay constants among the various components of a Goldstone supermultiplet. The general results are applied to chiral-symmetry breaking in two-flavor SUSY QCD

  15. Evaluation of bilirubin interference and accuracy of six creatinine assays compared with isotope dilution-liquid chromatography mass spectrometry.

    Science.gov (United States)

    Nah, Hyunjin; Lee, Sang-Guk; Lee, Kyeong-Seob; Won, Jae-Hee; Kim, Hyun Ok; Kim, Jeong-Ho

    2016-02-01

    The aim of this study was to estimate bilirubin interference and accuracy of six routine methods for measuring creatinine compared with isotope dilution-liquid chromatography mass spectrometry (ID-LC/MS). A total of 40 clinical serum samples from 31 patients with serum total bilirubin concentration >68.4μmol/L were collected. Serum creatinine was measured using two enzymatic reagents and four Jaffe reagents as well as ID-LC/MS. Correlations between bilirubin concentration and percent difference in creatinine compared with ID-LC/MS were analyzed to investigate bilirubin interference. Bias estimations between the six reagents and ID-LC/MS were performed. Recovery tests using National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 967a were also performed. Both the enzymatic methods showed no bilirubin interference. However, three of the four Jaffe methods demonstrated significant bilirubin concentration-dependent interference in samples with creatinine levels creatinine levels ranging from 53.0 to 97.2μmol/L. Comparison of these methods with ID-LC/MS using patients' samples with elevated bilirubin revealed that the tested methods failed to achieve the bias goal at especially low levels of creatinine. In addition, recovery test using NIST SRM 967a showed that bias in one Jaffe method and two enzymatic methods did not achieve the bias goal at either low or high level of creatinine, indicating they had calibration bias. One enzymatic method failed to achieve all the bias goals in both comparison experiment and recovery test. It is important to understand that both bilirubin interference and calibration traceability to ID-LC/MS should be considered to improve the accuracy of creatinine measurement. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  16. Accuracy of Coverage Survey Recall following an Integrated Mass Drug Administration for Lymphatic Filariasis, Schistosomiasis, and Soil-Transmitted Helminthiasis

    Science.gov (United States)

    Budge, Philip J.; Sognikin, Edmond; Akosa, Amanda; Mathieu, Els M.; Deming, Michael

    2016-01-01

    Background Achieving target coverage levels for mass drug administration (MDA) is essential to elimination and control efforts for several neglected tropical diseases (NTD). To ensure program goals are met, coverage reported by drug distributors may be validated through household coverage surveys that rely on respondent recall. This is the first study to assess accuracy in such surveys. Methodology/Principal Findings Recall accuracy was tested in a series of coverage surveys conducted at 1, 6, and 12 months after an integrated MDA in Togo during which three drugs (albendazole, ivermectin, and praziquantel) were distributed. Drug distribution was observed during the MDA to ensure accurate recording of persons treated during the MDA. Information was obtained for 506, 1131, and 947 persons surveyed at 1, 6, and 12 months, respectively. Coverage (defined as the percentage of persons taking at least one of the MDA medications) within these groups was respectively 88.3%, 87.4%, and 80.0%, according to the treatment registers; it was 87.9%, 91.4% and 89.4%, according to survey responses. Concordance between respondents and registers on swallowing at least one pill was >95% at 1 month and >86% at 12 months; the lower concordance at 12 months was more likely due to difficulty matching survey respondents with the year-old treatment register rather than inaccurate responses. Respondents generally distinguished between pills similar in appearance; concordance for recall of which pills were taken was over 80% in each survey. Significance In this population, coverage surveys provided remarkably consistent coverage estimates for up to one year following an integrated MDA. It is not clear if similar consistency will be seen in other settings, however, these data suggest that in some settings coverage surveys might be conducted as much as one year following an MDA without compromising results. This might enable integration of post-MDA coverage measurement into large, multipurpose

  17. Accuracy of Coverage Survey Recall following an Integrated Mass Drug Administration for Lymphatic Filariasis, Schistosomiasis, and Soil-Transmitted Helminthiasis.

    Science.gov (United States)

    Budge, Philip J; Sognikin, Edmond; Akosa, Amanda; Mathieu, Els M; Deming, Michael

    2016-01-01

    Achieving target coverage levels for mass drug administration (MDA) is essential to elimination and control efforts for several neglected tropical diseases (NTD). To ensure program goals are met, coverage reported by drug distributors may be validated through household coverage surveys that rely on respondent recall. This is the first study to assess accuracy in such surveys. Recall accuracy was tested in a series of coverage surveys conducted at 1, 6, and 12 months after an integrated MDA in Togo during which three drugs (albendazole, ivermectin, and praziquantel) were distributed. Drug distribution was observed during the MDA to ensure accurate recording of persons treated during the MDA. Information was obtained for 506, 1131, and 947 persons surveyed at 1, 6, and 12 months, respectively. Coverage (defined as the percentage of persons taking at least one of the MDA medications) within these groups was respectively 88.3%, 87.4%, and 80.0%, according to the treatment registers; it was 87.9%, 91.4% and 89.4%, according to survey responses. Concordance between respondents and registers on swallowing at least one pill was >95% at 1 month and >86% at 12 months; the lower concordance at 12 months was more likely due to difficulty matching survey respondents with the year-old treatment register rather than inaccurate responses. Respondents generally distinguished between pills similar in appearance; concordance for recall of which pills were taken was over 80% in each survey. In this population, coverage surveys provided remarkably consistent coverage estimates for up to one year following an integrated MDA. It is not clear if similar consistency will be seen in other settings, however, these data suggest that in some settings coverage surveys might be conducted as much as one year following an MDA without compromising results. This might enable integration of post-MDA coverage measurement into large, multipurpose, periodic surveys, thereby conserving resources.

  18. Accuracy of Coverage Survey Recall following an Integrated Mass Drug Administration for Lymphatic Filariasis, Schistosomiasis, and Soil-Transmitted Helminthiasis.

    Directory of Open Access Journals (Sweden)

    Philip J Budge

    2016-01-01

    Full Text Available Achieving target coverage levels for mass drug administration (MDA is essential to elimination and control efforts for several neglected tropical diseases (NTD. To ensure program goals are met, coverage reported by drug distributors may be validated through household coverage surveys that rely on respondent recall. This is the first study to assess accuracy in such surveys.Recall accuracy was tested in a series of coverage surveys conducted at 1, 6, and 12 months after an integrated MDA in Togo during which three drugs (albendazole, ivermectin, and praziquantel were distributed. Drug distribution was observed during the MDA to ensure accurate recording of persons treated during the MDA. Information was obtained for 506, 1131, and 947 persons surveyed at 1, 6, and 12 months, respectively. Coverage (defined as the percentage of persons taking at least one of the MDA medications within these groups was respectively 88.3%, 87.4%, and 80.0%, according to the treatment registers; it was 87.9%, 91.4% and 89.4%, according to survey responses. Concordance between respondents and registers on swallowing at least one pill was >95% at 1 month and >86% at 12 months; the lower concordance at 12 months was more likely due to difficulty matching survey respondents with the year-old treatment register rather than inaccurate responses. Respondents generally distinguished between pills similar in appearance; concordance for recall of which pills were taken was over 80% in each survey.In this population, coverage surveys provided remarkably consistent coverage estimates for up to one year following an integrated MDA. It is not clear if similar consistency will be seen in other settings, however, these data suggest that in some settings coverage surveys might be conducted as much as one year following an MDA without compromising results. This might enable integration of post-MDA coverage measurement into large, multipurpose, periodic surveys, thereby conserving

  19. Uncertainty analysis in Titan ionospheric simulated ion mass spectra: unveiling a set of issues for models accuracy improvement

    Science.gov (United States)

    Hébrard, Eric; Carrasco, Nathalie; Dobrijevic, Michel; Pernot, Pascal

    Ion Neutral Mass Spectrometer (INMS) aboard Cassini revealed a rich coupled ion-neutral chemistry in the ionosphere, producing heavy hydrocarbons and nitriles ions. The modeling of such a complex environment is challenging, as it requires a detailed and accurate description of the different relevant processes such as photodissociation cross sections and neutral-neutral reaction rates on one hand, and ionisation cross sections, ion-molecule and recombination reaction rates on the other hand. Underpinning models calculations, each of these processes is parameterized by kinetic constants which, when known, have been studied experimentally and/or theoretically over a range of temperatures and pressures that are most often not representative of Titan's atmosphere. The sizeable experimental and theoretical uncertainties reported in the literature merge therefore with the uncertainties resulting subsequently from the unavoidable estimations or extrapolations to Titan's atmosphere conditions. Such large overall uncertainties have to be accounted for in all resulting inferences most of all to evaluate the quality of the model definition. We have undertaken a systematic study of the uncertainty sources in the simulation of ion mass spectra as recorded by Cassini/INMS in Titan ionosphere during the T5 flyby at 1200 km. Our simulated spectra seem much less affected by the uncertainties on ion-molecule reactions than on neutral-neutral reactions. Photochemical models of Titan's atmosphere are indeed so poorly predictive at high altitudes, in the sense that their computed predictions display such large uncertainties, that we found them to give rise to bimodal and hypersensitive abundance distributions for some major compounds like acetylene C2 H2 and ethylene C2 H4 . We will show to what extent global uncertainty and sensitivity analysis enabled us to identify the causes of this bimodality and to pinpoint the key processes that mostly contribute to limit the accuracy of the

  20. Composition gradients across spiral galaxies II. The stellar mass limit

    International Nuclear Information System (INIS)

    Shields, G.A.; Tinsley, B.M.

    1976-01-01

    The equivalent width of the Hβ emission from H ii regions in spiral galaxies increases with distance from the nucleus. This W (Hβ) gradient is interpreted in terms of a radial gradient in the temperature of the hottest exciting stars. (T/subu/). From Searle's observations of M101, an increase Δ log T/subu/=0.02--0.13 from the intermediate to outermost spiral arms of M101 is inferred. There is also a radial decrease in the metal abundance (Z) across M101, and the T/subu/ gradient is consistent with the prediction of Kahn's recent theory that the upper mass limit for star formation should be smaller in regions of high Z. It is noted also that, even in the absence of changes in the upper mass limit, a T/subu/ gradient is expected because metal-rich stars of given mass have smaller effective temperatures. Several observational and theoretical improvements are needed before firm conclusions can be drawn, but it is clear that the presence of a T/subu/ gradient may lead to several important systematic changes in the interpretation of gradients in the properties of H ii regions across galaxies. A T/subu/ gradient reduces the Z gradient that is inferred from emission-line ratios, and it may help to explain why O ii is strong in the innermost regions where O iii is weak. A T/subu/ gradient may also partly camouflage a helium abundance gradient

  1. Combine body mass index and body fat percentage measures to improve the accuracy of obesity screening in young adults.

    Science.gov (United States)

    Hung, Shang-Ping; Chen, Ching-Yu; Guo, Fei-Ran; Chang, Ching-I; Jan, Chyi-Feng

    Obesity screening among young adult groups is meaningful. Body mass index (BMI) is limited to discriminate between fat and lean mass. Asian young adult group tends to have lower BMI and higher body fat percentage (BFP) than other ethnic groups. Accuracy of obesity screening by commonly used BMI criteria is unclear in young Taiwanese population. A total of 894 young adults (447 males and 447 females) aged 20-26 were recruited. BMI, regional fat percentage and BFP determined by bioelectrical impedance analysis (BIA) were measured. BMI cutoff points were based on the criteria adopted by the Ministry of Health and Welfare in Taiwan. Cutoff points of low or high BFP were defined as 24% in men and 31.4% in women. Prevalence of BFP defining obesity was 14.8% in young men and 27.3% in young women. 23.2% of young men and only 8.3% of young women were classified to overweight or obesity categories according to the BMI criteria. Disagreement was noticed mainly among overweight males and normal weight females. 68.7% of BMI defining overweight young men had low BFP; however, 29.7% of young women of BMI defining normal group had high BFP. Up to 69.7% of young women with high BFP would be missed by BMI category only. Disagreement between BMI and BFP was significant among young adults, especially young women. We suggest combining BMI and BIA for obesity and overweight screening in Asian young adults. Copyright © 2016 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

  2. Human brain mass: similar body composition associations as observed across mammals.

    Science.gov (United States)

    Heymsfield, Steven B; Müller, Manfred J; Bosy-Westphal, Anja; Thomas, Diana; Shen, Wei

    2012-01-01

    A classic association is the link between brain mass and body mass across mammals that has now been shown to derive from fat-free mass (FFM) and not fat mass (FM). This study aimed to establish for the first time the associations between human brain mass and body composition and to compare these relations with those established for liver as a reference organ. Subjects were 112 men and 148 women who had brain and liver mass measured by magnetic resonance imaging with FM and FFM measured by dual-energy X-ray absorptiometry. Brain mass scaled to height (H) with powers of ≤0.6 in men and women; liver mass and FFM both scaled similarly as H(~2) . The fraction of FFM as brain thus scaled inversely to height (P FFM was independent of height. After controlling for age, brain, and liver mass were associated with FFM while liver was additionally associated with FM (all models P ≤ 0.01). After controlling for age and sex, FFM accounted for ~5% of the variance in brain mass while levels were substantially higher for liver mass (~60%). Brain mass was significantly larger (P FFM. As across mammals, human brain mass associates significantly, although weakly, with FFM and not FM; the fraction of FFM as brain relates inversely to height; brain differs in these relations from liver, another small high metabolic rate organ; and the sexual dimorphism in brain mass persists even after adjusting for age and FFM. Copyright © 2012 Wiley Periodicals, Inc.

  3. A Meta-Analysis of Typhoid Diagnostic Accuracy Studies: A Recommendation to Adopt a Standardized Composite Reference.

    Directory of Open Access Journals (Sweden)

    Helen L Storey

    Full Text Available Novel typhoid diagnostics currently under development have the potential to improve clinical care, surveillance, and the disease burden estimates that support vaccine introduction. Blood culture is most often used as the reference method to evaluate the accuracy of new typhoid tests; however, it is recognized to be an imperfect gold standard. If no single gold standard test exists, use of a composite reference standard (CRS can improve estimation of diagnostic accuracy. Numerous studies have used a CRS to evaluate new typhoid diagnostics; however, there is no consensus on an appropriate CRS. In order to evaluate existing tests for use as a reference test or inclusion in a CRS, we performed a systematic review of the typhoid literature to include all index/reference test combinations observed. We described the landscape of comparisons performed, showed results of a meta-analysis on the accuracy of the more common combinations, and evaluated sources of variability based on study quality. This wide-ranging meta-analysis suggests that no single test has sufficiently good performance but some existing diagnostics may be useful as part of a CRS. Additionally, based on findings from the meta-analysis and a constructed numerical example demonstrating the use of CRS, we proposed necessary criteria and potential components of a typhoid CRS to guide future recommendations. Agreement and adoption by all investigators of a standardized CRS is requisite, and would improve comparison of new diagnostics across independent studies, leading to the identification of a better reference test and improved confidence in prevalence estimates.

  4. Intracellular water exchange for measuring the dry mass, water mass and changes in chemical composition of living cells.

    Directory of Open Access Journals (Sweden)

    Francisco Feijó Delgado

    Full Text Available We present a method for direct non-optical quantification of dry mass, dry density and water mass of single living cells in suspension. Dry mass and dry density are obtained simultaneously by measuring a cell's buoyant mass sequentially in an H2O-based fluid and a D2O-based fluid. Rapid exchange of intracellular H2O for D2O renders the cell's water content neutrally buoyant in both measurements, and thus the paired measurements yield the mass and density of the cell's dry material alone. Utilizing this same property of rapid water exchange, we also demonstrate the quantification of intracellular water mass. In a population of E. coli, we paired these measurements to estimate the percent dry weight by mass and volume. We then focused on cellular dry density - the average density of all cellular biomolecules, weighted by their relative abundances. Given that densities vary across biomolecule types (RNA, DNA, protein, we investigated whether we could detect changes in biomolecular composition in bacteria, fungi, and mammalian cells. In E. coli, and S. cerevisiae, dry density increases from stationary to exponential phase, consistent with previously known increases in the RNA/protein ratio from up-regulated ribosome production. For mammalian cells, changes in growth conditions cause substantial shifts in dry density, suggesting concurrent changes in the protein, nucleic acid and lipid content of the cell.

  5. Intracellular Water Exchange for Measuring the Dry Mass, Water Mass and Changes in Chemical Composition of Living Cells

    Science.gov (United States)

    Hecht, Vivian C.; Son, Sungmin; Li, Yingzhong; Knudsen, Scott M.; Olcum, Selim; Higgins, John M.; Chen, Jianzhu; Grover, William H.; Manalis, Scott R.

    2013-01-01

    We present a method for direct non-optical quantification of dry mass, dry density and water mass of single living cells in suspension. Dry mass and dry density are obtained simultaneously by measuring a cell’s buoyant mass sequentially in an H2O-based fluid and a D2O-based fluid. Rapid exchange of intracellular H2O for D2O renders the cell’s water content neutrally buoyant in both measurements, and thus the paired measurements yield the mass and density of the cell’s dry material alone. Utilizing this same property of rapid water exchange, we also demonstrate the quantification of intracellular water mass. In a population of E. coli, we paired these measurements to estimate the percent dry weight by mass and volume. We then focused on cellular dry density – the average density of all cellular biomolecules, weighted by their relative abundances. Given that densities vary across biomolecule types (RNA, DNA, protein), we investigated whether we could detect changes in biomolecular composition in bacteria, fungi, and mammalian cells. In E. coli, and S. cerevisiae, dry density increases from stationary to exponential phase, consistent with previously known increases in the RNA/protein ratio from up-regulated ribosome production. For mammalian cells, changes in growth conditions cause substantial shifts in dry density, suggesting concurrent changes in the protein, nucleic acid and lipid content of the cell. PMID:23844039

  6. Influence of size and surface structure of microparticles on accuracy of measurements of its uranium isotopic composition

    International Nuclear Information System (INIS)

    Stebelkov, V.; Kolesnikov, O.; Moulenko, D.; Sokolov, A.; Pavlov, A.; Simakin, S.

    2002-01-01

    Full text: One of the elements of the scheme for complex analysis of environmental samples, collected in the regions of location of nuclear facilities, is mass-spectrometry of microparticles of nuclear materials implemented for determination of isotopic composition of these materials. Widely used technique of mass-spectrometry of particles is secondary ion mass-spectrometry. This technique is characterized by successive acquisition of ions from different isotopes under gradual sputtering of microparticle during analysis. The purpose of this work was investigation of kinetic of size changing and changing of measured values of uranium-235 concentration as well as investigation of influence of size and surface structure of microparticle on measurement results. Method of investigation had been comprised to several sequential measurements of uranium isotopes content in the same particle and photography of this particle before every sequential measurement by using electron microscope. Analysis of each particle was finished when this particle was fully sputtered. There were investigated 33 particles of irregular shape and initial sizes from 0.5 μm to 3.5 μm. These particles had different types of surface structure and different isotopic composition. Besides there were investigated 22 spherical particles of UO 2 with 3.7% uranium-235 abundance with sizes from 0.7 μm to 2.4 μm. Thirteen particles of irregular shape were sputtered fully during first measurement of isotopic composition. Two sequential measurements were implemented for 12 particles, three sequential measurements were implemented for 7 particles. For 2 particles of sizes 3.5 μm x 2 μm and 1.2 μm there were implemented four sequential measurements of isotopic composition. During these investigations it was determined that the number of sequential measurements depends not only on size but also on surface structure of particle. With rare exception the sequential values of concentrations of uranium-235

  7. Scaling of human body composition to stature: new insights into body mass index.

    Science.gov (United States)

    Heymsfield, Steven B; Gallagher, Dympna; Mayer, Laurel; Beetsch, Joel; Pietrobelli, Angelo

    2007-07-01

    Although Quetelet first reported in 1835 that adult weight scales to the square of stature, limited or no information is available on how anatomical body compartments, including adipose tissue (AT), scale to height. We examined the critical underlying assumptions of adiposity-body mass index (BMI) relations and extended these analyses to major anatomical compartments: skeletal muscle (SM), bone, residual mass, weight (AT+SM+bone), AT-free mass, and organs (liver, brain). This was a cross-sectional analysis of 2 body-composition databases: one including magnetic resonance imaging and dual-energy X-ray absorptiometry (DXA) estimates of evaluated components in adults (total n=411; organs=76) and the other a larger DXA database (n=1346) that included related estimates of fat, fat-free mass, and bone mineral mass. Weight, primary lean components (SM, residual mass, AT-free mass, and fat-free mass), and liver scaled to height with powers of approximately 2 (all P2 (2.31-2.48), and the fraction of weight as bone mineral mass was significantly (Pshort and tall subjects with equivalent BMIs have similar but not identical body composition, provide new insights into earlier BMI-related observations and thus establish a foundation for height-normalized indexes, and create an analytic framework for future studies.

  8. Scaling of human body composition to stature: new insights into body mass index 123

    Science.gov (United States)

    Heymsfield, Steven B; Gallagher, Dympna; Mayer, Laurel; Beetsch, Joel; Pietrobelli, Angelo

    2009-01-01

    Background Although Quetelet first reported in 1835 that adult weight scales to the square of stature, limited or no information is available on how anatomical body compartments, including adipose tissue (AT), scale to height. Objective We examined the critical underlying assumptions of adiposity–body mass index (BMI) relations and extended these analyses to major anatomical compartments: skeletal muscle (SM), bone, residual mass, weight (AT+SM+bone), AT-free mass, and organs (liver, brain). Design This was a cross-sectional analysis of 2 body-composition databases: one including magnetic resonance imaging and dual-energy X-ray absorptiometry (DXA) estimates of evaluated components in adults (total n = 411; organs = 76) and the other a larger DXA database (n = 1346) that included related estimates of fat, fat-free mass, and bone mineral mass. Results Weight, primary lean components (SM, residual mass, AT-free mass, and fat-free mass), and liver scaled to height with powers of ≈2 (all P 2 (2.31–2.48), and the fraction of weight as bone mineral mass was significantly (P short and tall subjects with equivalent BMIs have similar but not identical body composition, provide new insights into earlier BMI-related observations and thus establish a foundation for height-normalized indexes, and create an analytic framework for future studies. PMID:17616766

  9. Radiometric determinations of linear mass, resin levels and density of composite materials

    International Nuclear Information System (INIS)

    Boutaine, J.L.; Pintena, J.; Tanguy, J.C.

    1978-01-01

    A description is given of the principle, characteristics and performances of a gamma back-scattering gauge developed in cooperation between the CEA and SNPE. This instrument allows for on-line inspection of the linear mass and resin level of strips of composite materials whilst being produced. The industrial application involved boron, carbon and 'Kevlar' fibres. The performance of beta and gamma transmission gauges are also given for inspecting the density of panels and dense composite materials [fr

  10. Improved accuracy and precision in δ15 NAIR measurements of explosives, urea, and inorganic nitrates by elemental analyzer/isotope ratio mass spectrometry using thermal decomposition.

    Science.gov (United States)

    Lott, Michael J; Howa, John D; Chesson, Lesley A; Ehleringer, James R

    2015-08-15

    Elemental analyzer systems generate N(2) and CO(2) for elemental composition and isotope ratio measurements. As quantitative conversion of nitrogen in some materials (i.e., nitrate salts and nitro-organic compounds) is difficult, this study tests a recently published method - thermal decomposition without the addition of O(2) - for the analysis of these materials. Elemental analyzer/isotope ratio mass spectrometry (EA/IRMS) was used to compare the traditional combustion method (CM) and the thermal decomposition method (TDM), where additional O(2) is eliminated from the reaction. The comparisons used organic and inorganic materials with oxidized and/or reduced nitrogen and included ureas, nitrate salts, ammonium sulfate, nitro esters, and nitramines. Previous TDM applications were limited to nitrate salts and ammonium sulfate. The measurement precision and accuracy were compared to determine the effectiveness of converting materials containing different fractions of oxidized nitrogen into N(2). The δ(13) C(VPDB) values were not meaningfully different when measured via CM or TDM, allowing for the analysis of multiple elements in one sample. For materials containing oxidized nitrogen, (15) N measurements made using thermal decomposition were more precise than those made using combustion. The precision was similar between the methods for materials containing reduced nitrogen. The %N values were closer to theoretical when measured by TDM than by CM. The δ(15) N(AIR) values of purchased nitrate salts and ureas were nearer to the known values when analyzed using thermal decomposition than using combustion. The thermal decomposition method addresses insufficient recovery of nitrogen during elemental analysis in a variety of organic and inorganic materials. Its implementation requires relatively few changes to the elemental analyzer. Using TDM, it is possible to directly calibrate certain organic materials to international nitrate isotope reference materials without off

  11. Development of novel nano-composite membranes as introduction systems for mass spectrometers: Contrasting nano-composite membranes and conventional inlet systems

    Science.gov (United States)

    Miranda, Luis Diego

    This dissertation presents the development of novel nano-composite membranes as introduction systems for mass spectrometers. These nano-composite membranes incorporate anodic aluminum oxide (AAO) membranes as templates that can be used by themselves or modified by a variety of chemical deposition processes. Two types of nano-composite membranes are presented. The first nano-composite membrane has carbon deposited within the pores of an AAO membrane. The second nano-composite membrane is made by coating an AAO membrane with a thin polymer film. The following chapters describe the transmission properties these nano-composite membranes and compare them to conventional mass spectrometry introduction systems. The nano- composite membranes were finally coupled to the inlet system of an underwater mass spectrometer revealing their utility in field deployments.

  12. Study of the interaction of liquid with the surface of mass standards of high accuracy stainless steel

    International Nuclear Information System (INIS)

    Ramirez Varas, Lautaro; Castro, Claudio S.C.; Cacais, Fabio L.; Pires, Manoel J. M.; Loayza Mendoza, Victor M.

    2011-01-01

    The long term stability of mass standards depends on the interaction between the surface and environment molecules. From this point of view, a study was investigated of the effect on stainless steel surfaces by liquids frequently used in hydrostatic weighing (FC40) and in cleaning procedures of mass standards (isopropyl alcohol). Firstly, mass weighing difference was measured as function of time with a gravimetric method. Additionally, stainless steel samples were analyzed by X-ray Photoelectron Spectroscopy (XPS). The standard used for the gravimetric mass difference determination was immersed in FC40. The samples analyzed by XPS were previously immersed in both FC40 and isopropyl alcohol. Mass differences were obtained with an uncertainty of 1 μg when FC40 was used. Preliminary results have suggested that FC40 is not chemically bound to stainless steel surfaces and the mass gain was due to physisorbed molecules on the surface. (author) [es

  13. Improved accuracy of cortical bone mineralization measured by polychromatic microcomputed tomography using a novel high mineral density composite calibration phantom

    International Nuclear Information System (INIS)

    Deuerling, Justin M.; Rudy, David J.; Niebur, Glen L.; Roeder, Ryan K.

    2010-01-01

    Purpose: Microcomputed tomography (micro-CT) is increasingly used as a nondestructive alternative to ashing for measuring bone mineral content. Phantoms are utilized to calibrate the measured x-ray attenuation to discrete levels of mineral density, typically including levels up to 1000 mg HA/cm 3 , which encompasses levels of bone mineral density (BMD) observed in trabecular bone. However, levels of BMD observed in cortical bone and levels of tissue mineral density (TMD) in both cortical and trabecular bone typically exceed 1000 mg HA/cm 3 , requiring extrapolation of the calibration regression, which may result in error. Therefore, the objectives of this study were to investigate (1) the relationship between x-ray attenuation and an expanded range of hydroxyapatite (HA) density in a less attenuating polymer matrix and (2) the effects of the calibration on the accuracy of subsequent measurements of mineralization in human cortical bone specimens. Methods: A novel HA-polymer composite phantom was prepared comprising a less attenuating polymer phase (polyethylene) and an expanded range of HA density (0-1860 mg HA/cm 3 ) inclusive of characteristic levels of BMD in cortical bone or TMD in cortical and trabecular bone. The BMD and TMD of cortical bone specimens measured using the new HA-polymer calibration phantom were compared to measurements using a conventional HA-polymer phantom comprising 0-800 mg HA/cm 3 and the corresponding ash density measurements on the same specimens. Results: The HA-polymer composite phantom exhibited a nonlinear relationship between x-ray attenuation and HA density, rather than the linear relationship typically employed a priori, and obviated the need for extrapolation, when calibrating the measured x-ray attenuation to high levels of mineral density. The BMD and TMD of cortical bone specimens measured using the conventional phantom was significantly lower than the measured ash density by 19% (p<0.001, ANCOVA) and 33% (p<0.05, Tukey's HSD

  14. Prediction of renal function (GFR) from cystatin C and creatinine in children: Body cell mass increases accuracy of the estimate

    DEFF Research Database (Denmark)

    Andersen, Trine Borup; Jødal, Lars; Bøgsted, Martin

    using robust regression in a forward, stepwise procedure. GFR (mL/min) was the dependent variable. The accuracy and precision of the prediction model were compared to other prediction models from the literature, using k-fold cross-validation. Local constants and coefficients were calculated for all...

  15. Understanding the mass-radius relation for sub-Neptunes: radius as a proxy for composition

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Eric D.; Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2014-09-01

    Transiting planet surveys like Kepler have provided a wealth of information on the distribution of planetary radii, particularly for the new populations of super-Earth- and sub-Neptune-sized planets. In order to aid in the physical interpretation of these radii, we compute model radii for low-mass rocky planets with hydrogen-helium envelopes. We provide model radii for planets 1-20 M {sub ⊕}, with envelope fractions 0.01%-20%, levels of irradiation 0.1-1000 times Earth's, and ages from 100 Myr to 10 Gyr. In addition we provide simple analytic fits that summarize how radius depends on each of these parameters. Most importantly, we show that at fixed H/He envelope fraction, radii show little dependence on mass for planets with more than ∼1% of their mass in their envelope. Consequently, planetary radius is to a first order a proxy for planetary composition, i.e., H/He envelope fraction, for Neptune- and sub-Neptune-sized planets. We recast the observed mass-radius relationship as a mass-composition relationship and discuss it in light of traditional core accretion theory. We discuss the transition from rocky super-Earths to sub-Neptune planets with large volatile envelopes. We suggest ∼1.75 R {sub ⊕} as a physically motivated dividing line between these two populations of planets. Finally, we discuss these results in light of the observed radius occurrence distribution found by Kepler.

  16. Vibration Analysis of Inclined Laminated Composite Beams under Moving Distributed Masses

    Directory of Open Access Journals (Sweden)

    E. Bahmyari

    2014-01-01

    Full Text Available The dynamic response of laminated composite beams subjected to distributed moving masses is investigated using the finite element method (FEM based on the both first-order shear deformation theory (FSDT and the classical beam theory (CLT. Six and ten degrees of freedom beam elements are used to discretize the CLT and FSDT equations of motion, respectively. The resulting spatially discretized beam governing equations including the effect of inertial, Coriolis, and centrifugal forces due to moving distributed mass are evaluated in time domain by applying Newmark’s scheme. The presented approach is first validated by studying its convergence behavior and comparing the results with those of existing solutions in the literature. Then, the effect of incline angle, mass, and velocity of moving body, layer orientation, load length, and inertial, Coriolis, and centrifugal forces due to the moving distributed mass and friction force between the beam and the moving distributed mass on the dynamic behavior of inclined laminated composite beams are investigated.

  17. Mass composition studies using the surface detector of the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    Wahlberg, Hernan

    2009-01-01

    The mass composition of ultra-high energy cosmic rays is a critical issue to understand their origin and nature. The Pierre Auger Observatory is a hybrid instrument which provides a powerful environment for the determination of the primary mass. The Surface Detector of the Pierre Auger Observatory alone allows the study of several shower parameters with high discriminating power between primary elements. Novel analysis techniques using different features of signals in the Cherenkov stations are discussed. These are the signal risetime, the azimuthal time asymmetry and the muon density of the showers.

  18. A miniaturized laser-ablation mass spectrometer for in-situ measurements of isotope composition on solar body surfaces

    Science.gov (United States)

    Riedo, A.; Meyer, S.; Tulej, M.; Neuland, M.; Bieler, A.; Iakovleva, M.; Wurz, P.

    2012-04-01

    space instrument would have a cylindrical shape with a length of 120 mm, and a diameter of 60 mm, and a weight of about 1.5 kg (all electronics included). The mass analyzer supports high dynamic range of about 107 and a typical mass resolution of m/Δm~700. A computer-controlled optimizer controls the reproducibility of the performance of the mass analyzer, the laser fluence and the positioning of the sample. The system supports highly sensitive studies of elemental composition with sub-ppm detection limits. Our studies show that high accuracy and precision measurements can also be achieved in the investigations of isotopic patterns. Our initial studies of lead isotopic pattern indicated an accuracy and precision in the per mile range, which are comparable to that achieved by other - well known in isotopic analysis - mass spectrometric techniques, i.e., TIMS, SIMS, LA-ICP-MS used in the laboratory. The initial studies were conducted with Galena minerals and NIST standards. Hence, the miniaturized laser ablation time-of-flight mass spectrometer is a powerful instrument for in-situ measurements for the further investigation in surface characterization.

  19. Inkjet metrology: high-accuracy mass measurements of microdroplets produced by a drop-on-demand dispenser.

    Science.gov (United States)

    Verkouteren, R Michael; Verkouteren, Jennifer R

    2009-10-15

    We describe gravimetric methods for measuring the mass of droplets generated by a drop-on-demand (DOD) microdispenser. Droplets are deposited, either continuously at a known frequency or as a burst of known number, into a cylinder positioned on a submicrogram balance. Mass measurements are acquired precisely by computer, and results are corrected for evaporation. Capabilities are demonstrated using isobutyl alcohol droplets. For ejection rates greater than 100 Hz, the repeatability of droplet mass measurements was 0.2%, while the combined relative standard uncertainty (u(c)) was 0.9%. When bursts of droplets were dispensed, the limit of quantitation was 72 microg (1490 droplets) with u(c) = 1.0%. Individual droplet size in a burst was evaluated by high-speed videography. Diameters were consistent from the tenth droplet onward, and the mass of an individual droplet was best estimated by the average droplet mass with a combined uncertainty of about 1%. Diameters of the first several droplets were anomalous, but their contribution was accounted for when dispensing bursts. Above the limits of quantitation, the gravimetric methods provided statistically equivalent results and permit detailed study of operational factors that influence droplet mass during dispensing, including the development of reliable microassays and standard materials using DOD technologies.

  20. Prediction of renal function (GFR) from cystatin C and creatinine in children: Body cell mass increases accuracy of the estimate

    DEFF Research Database (Denmark)

    Andersen, Trine Borup; Jødal, Lars; Bøgsted, Martin

    ) aged 2-14 years (mean 8.8 years). GFR was 14-147 mL/min/1.73m2 (mean 97 mL/min/1.73m2). BCM was estimated using bioimpedance spectroscopy (Xitron Hydra 4200). Log-transformed data on BCM/CysC, serum creatinine (SCr), body-surface-area (BSA), height x BSA/SCr, serum CysC, weight, sex, age, height, serum....... The present equation also had the highest R2 and the narrowest 95% limits of agreement. CONCLUSION: The new equation predicts GFR with higher accuracy than other equations. Endogenous methods are, however, still not accurate enough to replace exogenous markers when GFR must be determined with high accuracy...

  1. GFR prediction from cystatin C and creatinine in children: body cell mass increases accuracy of the estimate

    DEFF Research Database (Denmark)

    Andersen, Trine Borup; Jødal, Lars; Bøgsted, Martin

    ) aged 2-14 years (mean 8.8 years). GFR was 14-147 mL/min/1.73m2 (mean 97 mL/min/1.73m2). BCM was estimated using bioimpedance spectroscopy (Xitron Hydra 4200). Log-transformed data on BCM/CysC, serum creatinine (SCr), body-surface-area (BSA), height x BSA/SCr, serum CysC, weight, sex, age, height, serum....... The present equation also had the highest R2 and the narrowest 95% limits of agreement. CONCLUSION: The new equation predicts GFR with higher accuracy than other equations. Endogenous methods are, however, still not accurate enough to replace exogenous markers when GFR must be determined with high accuracy...

  2. Evaluating the accuracy of uranium isotope amount ratio measurements performed by a quadrupole and a multi-collector magnetic sector inductively coupled plasma mass spectrometers for nuclear safeguards

    International Nuclear Information System (INIS)

    Pereira de Oliveira, O. Jr.; Sarkis, J.E.S.; Ponzevera, E.; Alonso, A.; De Bolle, W.; Quetel, C.

    2008-01-01

    The n(U 235 )/n(U 238 ) isotope amount ratio in a set of samples was measured using two modern analytical techniques: quadrupole inductively coupled plasma mass spectrometry (ICP-QMS) and multi-collector magnetic sector inductively coupled plasma mass spectrometry (MC-ICPMS). The measured ratios were compared to the certified ratios provided by the high accuracy gas source mass spectrometry (GSMS). The components of the uncertainty were identified and their contribution to the combined standard uncertainty was estimated using the recommendations of the ISO-GUM guide. The values of the measurement uncertainty and bias were determined and then compared to the International Target Values for Measurement Uncertainties in Safeguarding Nuclear Materials. It appears that only the measurements performed by MC-ICPMS can meet the stringent requirements of international nuclear safeguards. (authors)

  3. Composite Fermi surface in the half-filled Landau level with anisotropic electron mass

    Science.gov (United States)

    Ippoliti, Matteo; Geraedts, Scott; Bhatt, Ravindra

    We study the problem of interacting electrons in the lowest Landau level at half filling in the quantum Hall regime, when the electron dispersion is given by an anisotropic mass tensor. Based on experimental observations and theoretical arguments, the ground state of the system is expected to consist of composite Fermions filling an elliptical Fermi sea, with the anisotropy of the ellipse determined by the competing effects of the isotropic Coulomb interaction and anisotropic electron mass tensor. We test this idea quantitatively by using a numerical density matrix renormalization group method for quantum Hall systems on an infinitely long cylinder. Singularities in the structure factor allow us to map the Fermi surface of the composite Fermions. We compute the composite Fermi surface anisotropy for several values of the electron mass anisotropy which allow us to deduce the functional dependence of the former on the latter. This research was supported by Department of Energy Office of Basic Energy Sciences through Grant No. DE-SC0002140.

  4. Accuracy of Combined Computed Tomography Colonography and Dual Energy Iiodine Map Imaging for Detecting Colorectal masses using High-pitch Dual-source CT.

    Science.gov (United States)

    Sun, Kai; Han, Ruijuan; Han, Yang; Shi, Xuesen; Hu, Jiang; Lu, Bin

    2018-02-28

    To evaluate the diagnostic accuracy of combined computed tomography colonography (CTC) and dual-energy iodine map imaging for detecting colorectal masses using high-pitch dual-source CT, compared with optical colonography (OC) and histopathologic findings. Twenty-eight consecutive patients were prospectively enrolled in this study. All patients were underwent contrast-enhanced CTC acquisition using dual-energy mode and OC and pathologic examination. The size of the space-occupied mass, the CT value after contrast enhancement, and the iodine value were measured and statistically compared. The sensitivity, specificity, accuracy rate, and positive predictive and negative predictive values of dual-energy contrast-enhanced CTC were calculated and compared between conventional CTC and dual-energy iodine images. The iodine value of stool was significantly lower than the colonic neoplasia (P dual-energy iodine maps imaging was 95.6% (95% CI = 77.9%-99.2%). The specificity of the two methods was 42.8% (95% CI = 15.4%-93.5%) and 100% (95% CI = 47.9%-100%; P = 0.02), respectively. Compared with optical colonography and histopathology, combined CTC and dual-energy iodine maps imaging can distinguish stool and colonic neoplasia, distinguish between benign and malignant tumors initially and improve the diagnostic accuracy of CTC for colorectal cancer screening.

  5. Does the Equivalence between Gravitational Mass and Energy Survive for a Composite Quantum Body?

    Directory of Open Access Journals (Sweden)

    A. G. Lebed

    2014-01-01

    Full Text Available We define passive and active gravitational mass operators of the simplest composite quantum body—a hydrogen atom. Although they do not commute with its energy operator, the equivalence between the expectation values of passive and active gravitational masses and energy is shown to survive for stationary quantum states. In our calculations of passive gravitational mass operator, we take into account not only kinetic and Coulomb potential energies but also the so-called relativistic corrections to electron motion in a hydrogen atom. Inequivalence between passive and active gravitational masses and energy at a macroscopic level is demonstrated to reveal itself as time-dependent oscillations of the expectation values of the gravitational masses for superpositions of stationary quantum states. Breakdown of the equivalence between passive gravitational mass and energy at a microscopic level reveals itself as unusual electromagnetic radiation, emitted by macroscopic ensemble of hydrogen atoms, moved by small spacecraft with constant velocity in the Earth’s gravitational field. We suggest the corresponding experiment on the Earth’s orbit to detect this radiation, which would be the first direct experiment where quantum effects in general relativity are observed.

  6. Body Mass Index and Body Composition with Deuterium in Costa Rican Children

    International Nuclear Information System (INIS)

    Quintana-Guzmán, E.; Salas-Chaves, M. D. P.

    2015-01-01

    Body Mass Index (BMI) has been adopted as international measure for measuring adiposity in children with the disadvantage that it varies with age, sex and sexual maturation with no differentiation between fat mass and mass free of grease. The analysis of body composition allow to know if the overweight is due to fatty tissue being the deuterium isotope dilution a validated reference method using Infrared Spectrometry Transformed of Fourier (FTIR). We studied a total 118 boys and girls from 6 to 9 years old getting the values of z score of BMI for age and percentage of fat mass by FTIR. The results obtained in this study demonstrated that Costa Rica does not escape to the global problem of childhood obesity founding by BMI 18.6% of overweight and 10% of obesity and by body composition 9% of overweight and 57% of obesity. Isotopic deuterium dilution method demonstrated in this study to be more suitable for the analysis of obesity and overweight in children since BMI presented false positive and false negative results giving less accurate information of adiposity of the subject. (author)

  7. Breakdown of the equivalence between gravitational mass and energy for a composite quantum body

    International Nuclear Information System (INIS)

    Lebed, Andrei G

    2014-01-01

    The simplest quantum composite body, a hydrogen atom, is considered in the presence of a weak external gravitational field. We define an operator for the passive gravitational mass of the atom in the post-Newtonian approximation of the general relativity and show that it does not commute with its energy operator. Nevertheless, the equivalence between the expectation values of the mass and energy is shown to survive at a macroscopic level for stationary quantum states. Breakdown of the equivalence between passive gravitational mass and energy at a microscopic level for stationary quantum states can be experimentally detected by studying unusual electromagnetic radiation, emitted by the atoms, supported by and moving in the Earth's gravitational field with constant velocity, using spacecraft or satellite

  8. Center-of-mass correction and confinement radii of the composite vector bosons

    International Nuclear Information System (INIS)

    Tadic, D.; Tadic, G.

    1985-01-01

    Describing a composite W boson by a center-of-mass--corrected bag model one finds a relation R/sub W/ 3 M/sub W/ 3 / f/sub W/ 2 approx. =R/sub rho/ 3 m/sub rho/ 3 / f/sub rho/ 2 for the confinement radii (R), masses, and coupling constants (f) of W and rho bosons. Using experimental values for f/sub rho/, m/sub rho/, and M/sub W/ and with f/sub W/ = 0.66, one obtains R/sub W//R/sub rho/approx. =2 x 10 -3 . f/sub rho/, f/sub W/, and masses can be calculated separately

  9. THE MASS OF Kepler-93b AND THE COMPOSITION OF TERRESTRIAL PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Dressing, Courtney D.; Charbonneau, David; Dumusque, Xavier; Gettel, Sara; Latham, David W.; Buchhave, Lars A.; Johnson, John Asher; Lopez-Morales, Mercedes [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Pepe, Francesco; Udry, Stéphane; Lovis, Christophe [Observatoire Astronomique de l' Université de Genève, 51 ch. des Maillettes, 1290 Versoix (Switzerland); Collier Cameron, Andrew; Haywood, Raphaëlle D. [SUPA, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews Fife KY16 9SS (United Kingdom); Molinari, Emilio; Cosentino, Rosario; Fiorenzano, Aldo F. M.; Harutyunyan, Avet [INAF - Fundación Galileo Galilei, Rambla José Ana Fernandez Pérez 7, E-38712 Breña Baja (Spain); Affer, Laura [INAF - Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, I-90124 Palermo (Italy); Bonomo, Aldo S. [INAF - Osservatorio Astrofisico di Torino, via Osservatorio 20, I-10025 Pino Torinese (Italy); Figueira, Pedro, E-mail: cdressing@cfa.harvard.edu [Centro de Astrofìsica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); and others

    2015-02-20

    Kepler-93b is a 1.478 ± 0.019 R {sub ⊕} planet with a 4.7 day period around a bright (V = 10.2), astroseismically characterized host star with a mass of 0.911 ± 0.033 M {sub ☉} and a radius of 0.919 ± 0.011 R {sub ☉}. Based on 86 radial velocity observations obtained with the HARPS-N spectrograph on the Telescopio Nazionale Galileo and 32 archival Keck/HIRES observations, we present a precise mass estimate of 4.02 ± 0.68 M {sub ⊕}. The corresponding high density of 6.88 ± 1.18 g cm{sup –3} is consistent with a rocky composition of primarily iron and magnesium silicate. We compare Kepler-93b to other dense planets with well-constrained parameters and find that between 1 and 6 M {sub ⊕}, all dense planets including the Earth and Venus are well-described by the same fixed ratio of iron to magnesium silicate. There are as of yet no examples of such planets with masses >6 M {sub ⊕}. All known planets in this mass regime have lower densities requiring significant fractions of volatiles or H/He gas. We also constrain the mass and period of the outer companion in the Kepler-93 system from the long-term radial velocity trend and archival adaptive optics images. As the sample of dense planets with well-constrained masses and radii continues to grow, we will be able to test whether the fixed compositional model found for the seven dense planets considered in this paper extends to the full population of 1-6 M {sub ⊕} planets.

  10. Heat-Treatment-Responsive Proteins in Different Developmental Stages of Tomato Pollen Detected by Targeted Mass Accuracy Precursor Alignment (tMAPA).

    Science.gov (United States)

    Chaturvedi, Palak; Doerfler, Hannes; Jegadeesan, Sridharan; Ghatak, Arindam; Pressman, Etan; Castillejo, Maria Angeles; Wienkoop, Stefanie; Egelhofer, Volker; Firon, Nurit; Weckwerth, Wolfram

    2015-11-06

    Recently, we have developed a quantitative shotgun proteomics strategy called mass accuracy precursor alignment (MAPA). The MAPA algorithm uses high mass accuracy to bin mass-to-charge (m/z) ratios of precursor ions from LC-MS analyses, determines their intensities, and extracts a quantitative sample versus m/z ratio data alignment matrix from a multitude of samples. Here, we introduce a novel feature of this algorithm that allows the extraction and alignment of proteotypic peptide precursor ions or any other target peptide from complex shotgun proteomics data for accurate quantification of unique proteins. This strategy circumvents the problem of confusing the quantification of proteins due to indistinguishable protein isoforms by a typical shotgun proteomics approach. We applied this strategy to a comparison of control and heat-treated tomato pollen grains at two developmental stages, post-meiotic and mature. Pollen is a temperature-sensitive tissue involved in the reproductive cycle of plants and plays a major role in fruit setting and yield. By LC-MS-based shotgun proteomics, we identified more than 2000 proteins in total for all different tissues. By applying the targeted MAPA data-processing strategy, 51 unique proteins were identified as heat-treatment-responsive protein candidates. The potential function of the identified candidates in a specific developmental stage is discussed.

  11. New approach to 3-D, high sensitivity, high mass resolution space plasma composition measurements

    International Nuclear Information System (INIS)

    McComas, D.J.; Nordholt, J.E.

    1990-01-01

    This paper describes a new type of 3-D space plasma composition analyzer. The design combines high sensitivity, high mass resolution measurements with somewhat lower mass resolution but even higher sensitivity measurements in a single compact and robust design. While the lower resolution plasma measurements are achieved using conventional straight-through time-of-flight mass spectrometry, the high mass resolution measurements are made by timing ions reflected in a linear electric field (LEF), where the restoring force that an ion experiences is proportional to the depth it travels into the LEF region. Consequently, the ion's equation of motion in that dimension is that of a simple harmonic oscillator and its travel time is simply proportional to the square root of the ion's mass/charge (m/q). While in an ideal LEF, the m/q resolution can be arbitrarily high, in a real device the resolution is limited by the field linearity which can be achieved. In this paper we describe how a nearly linear field can be produced and discuss how the design can be optimized for various different plasma regimes and spacecraft configurations

  12. Determination of isotopic composition of uranium in microparticles by secondary ion mass spectrometry

    International Nuclear Information System (INIS)

    Veniaminov, N.N.; Kolesnikov, O.N.; Stebel'kov, V.A.

    1992-01-01

    Aerosol particles including uranium in their composition are specific atmospheric polutants. Uranium is used as nuclear fuel in atomic power stations and in spacecraft power units, and also as a component of nuclear warheads. In order to monitor the discharge of uranium-containing aerosol particles to the atmosphere, they must first be identified. As an example, one may cite an investigation of the elemental composition and radioactivity of particles formed in the accident at the Chernobyl atomic power station. One of the most informative indicators of the origin of uranium-containing aerosol particles is the isotopic composition of the uranium. Secondary ion mass spectrometry (SIMS) offers unique possibilities for the measurement of isotope ratios in individual microscopic objects. At the same time, a measurement of isotope ratios of sulfur in microsection of galenite PbS 2 has shown that the application of SIMS for these purposes is seriously limited by the difference in yield of secondary ions for isotopes with different masses. These discrimination effects, in the case of light elements such as boron, may result in distortion of the isotope ratios by several percent. In the case of heavy elements, however, the effect is less significant, amounting to about 0.5% for lead isotopes. 13 refs., 3 figs., 1 tab

  13. Development of a portable mass spectrometric system for determination of isotopic composition of solid uranium samples using fluorine volatilization. Final report

    International Nuclear Information System (INIS)

    Loge, G.

    1994-01-01

    Using hardware and materials supplied by LANL, a prototype quadrupole mass spectrometer system designed for portable field analysis of isotopic composition of solid uranium samples was assembled and tested. The system contained the capability for fluorine volatilization of solid uranium samples with gas introduction, which was successfully tested and demonstrated using 100 mg samples of U 3 O 8 . Determination of precision and accuracy for measuring isotopic composition was performed using isotopic standards. Use with soil samples containing uranium were also attempted. Silicates in the soil forming SiF 4 were found to be a kinetic bottleneck to the formation of UF 6 . This could be avoided by performing some sort of chemical separation as a pre-treatment step, which was demonstrated using nitric acid

  14. DETERMINATION OF THE MASS TRANSFER CHARACTERIZATION OF A CERAMIC-POLYMER COMPOSITE MEMBRANE IN THE PERVAPORATION MODE

    Science.gov (United States)

    The effect of the coating layer thickness on VOC extraction performance of a ceramic polymer composite membrane has been investigated. It was found, under experimental condiitons representing typical field operation, the overall mass transfer rates of feed components were control...

  15. Determination of Selected Polycyclic Aromatic Compounds in Particulate Matter Samples with Low Mass Loading: An Approach to Test Method Accuracy

    Directory of Open Access Journals (Sweden)

    Susana García-Alonso

    2017-01-01

    Full Text Available A miniaturized analytical procedure to determine selected polycyclic aromatic compounds (PACs in low mass loadings (<10 mg of particulate matter (PM is evaluated. The proposed method is based on a simple sonication/agitation method using small amounts of solvent for extraction. The use of a reduced sample size of particulate matter is often limiting for allowing the quantification of analytes. This also leads to the need for changing analytical procedures and evaluating its performance. The trueness and precision of the proposed method were tested using ambient air samples. Analytical results from the proposed method were compared with those of pressurized liquid and microwave extractions. Selected PACs (polycyclic aromatic hydrocarbons (PAHs and nitro polycyclic aromatic hydrocarbons (NPAHs were determined by liquid chromatography with fluorescence detection (HPLC/FD. Taking results from pressurized liquid extractions as reference values, recovery rates of sonication/agitation method were over 80% for the most abundant PAHs. Recovery rates of selected NPAHs were lower. Enhanced rates were obtained when methanol was used as a modifier. Intermediate precision was estimated by data comparison from two mathematical approaches: normalized difference data and pooled relative deviations. Intermediate precision was in the range of 10–20%. The effectiveness of the proposed method was evaluated in PM aerosol samples collected with very low mass loadings (<0.2 mg during characterization studies from turbofan engine exhausts.

  16. High accuracy experimental determination of copper and zinc mass attenuation coefficients in the 100 eV to 30 keV photon energy range

    Science.gov (United States)

    Ménesguen, Y.; Gerlach, M.; Pollakowski, B.; Unterumsberger, R.; Haschke, M.; Beckhoff, B.; Lépy, M.-C.

    2016-02-01

    The knowledge of atomic fundamental parameters such as mass attenuation coefficients with low uncertainties, is of decisive importance in elemental quantification using x-ray fluorescence analysis techniques. Several databases are accessible and frequently used within a large community of users. These compilations are most often in good agreement for photon energies in the hard x-ray ranges. However, they significantly differ for low photon energies and around the absorption edges of any element. In a joint cooperation of the metrology institutes of France and Germany, mass attenuation coefficients of copper and zinc were determined experimentally in the photon energy range from 100 eV to 30 keV by independent approaches using monochromatized synchrotron radiation at SOLEIL (France) and BESSY II (Germany), respectively. The application of high-accuracy experimental techniques resulted in mass attenuation coefficient datasets determined with low uncertainties that are directly compared to existing databases. The novel datasets are expected to enhance the reliability of mass attenuation coefficients.

  17. Lanthanum benzoyl acetonates: an IR and mass spectrometric study of the composition and structure

    International Nuclear Information System (INIS)

    Kostyuk, N.N.; Dik, T.A.; Tereshko, N.V.

    2005-01-01

    IR spectroscopy and mass spectrometry were used to study the structure of lanthanum chelates of benzoyl acetone (1-phenyl-1,3-butadione, HBA) of the following compositions: La(BA) 3 · EtOH, La(BA) 2 , La(BA) 2 · CH 3 CN, and La(BA) 2 · HDA, where EtOH = ethanol, HDA = nonadecanoic acid. It is demonstrated that a quasi-aromatic metalloring is formed in lanthanum chelates studied. Stable metal-containing fragments of the molecular ions of lanthanum bis- and tris-benzoylacetonate were identified [ru

  18. Mass transfer model liquid phase catalytic exchange column simulation applicable to any column composition profile

    Energy Technology Data Exchange (ETDEWEB)

    Busigin, A. [NITEK USA Inc., Ocala, FL (United States)

    2015-03-15

    Liquid Phase Catalytic Exchange (LPCE) is a key technology used in water detritiation systems. Rigorous simulation of LPCE is complicated when a column may have both hydrogen and deuterium present in significant concentrations in different sections of the column. This paper presents a general mass transfer model for a homogenous packed bed LPCE column as a set of differential equations describing composition change, and equilibrium equations to define the mass transfer driving force within the column. The model is used to show the effect of deuterium buildup in the bottom of an LPCE column from non-negligible D atom fraction in the bottom feed gas to the column. These types of calculations are important in the design of CECE (Combined Electrolysis and Catalytic Exchange) water detritiation systems.

  19. Mechanism of [m+h]+ formation in atmospheric pressure photoionization mass spectrometry: identification of propionitrile in acetonitrile with high mass accuracy measurement and tandem mass spectrometry and evidence for its involvement in the protonation phenomenon.

    Science.gov (United States)

    Kamel, Amin; Jeanville, Patrick; Colizza, Kevin; J-Rivera, Lauren Elizabeth

    2008-11-01

    The role of propionitrile in the production of [M+H]+ under atmospheric pressure photoionization (APPI) was investigated. In dopant-assisted APPI using acetone and anisole, protonated acetone and anisole radical cations were the most prominent ions observed. In dopant-free or direct APPI in acetonitrile, however, a major ion in acetonitrile was detected and identified as propionitrile, using high accuracy mass measurement and collision induced dissociation studies. Vaporizing ca. 10(-5) M althiazide and bendroflumethazide under direct APPI in acetonitrile produced their corresponding protonated species [M+H]+. In addition to protonated acetonitrile, its dimers, and acetonitrile/water clusters, protonated propionitrile, propionitrile dimer, and propionitrile/water clusters were also observed. The role of propionitrile, an impurity in acetonitrile and/or a possible product of ion-molecule reaction, in the production of [M+H]+ of althiazide and bendroflumethazide was further investigated in the absence of dopant using propionitrile-d5. The formation of [M+D]+ species was observed, suggesting a possible role of propionitrile in the protonation process. Additionally, an increase in the [M+H]+ signal of althiazide and bendroflumethazide was observed as a function of propionitrile concentration in acetonitrile. Theoretical data from the literature supported the assumption that one possible mechanism, among others, for the formation of [M+H]+ could be attributed to photo-initiated isomerization of propionitrile. The most stable isomers of propionitrile, based on their calculated ionization energy (IE) and relative energy (DeltaE), were assumed to undergo proton transfer to the analytes, and mechanisms were proposed.

  20. Response-only method for damage detection of beam-like structures using high accuracy frequencies with auxiliary mass spatial probing

    Science.gov (United States)

    Zhong, Shuncong; Oyadiji, S. Olutunde; Ding, Kang

    2008-04-01

    This paper proposes a new approach based on auxiliary mass spatial probing using spectral centre correction method (SCCM), to provide a simple solution for damage detection by just using the response time history of beam-like structures. The natural frequencies of a damaged beam with a traversing auxiliary mass change due to change in the inertia of the beam as the auxiliary mass is traversed along the beam, as well as the point-to-point variations in the flexibility of the beam. Therefore the auxiliary mass can enhance the effects of the crack on the dynamics of the beam and, therefore, facilitate the identification and location of damage in the beam. That is, the auxiliary mass can be used to probe the dynamic characteristic of the beam by traversing the mass from one end of the beam to the other. However, it is impossible to obtain accurate modal frequencies by the direct operation of the fast Fourier transform (FFT) of the response data of the structure because the frequency spectrum can be only calculated from limited sampled time data which results in the well-known leakage effect. SCCM is identical to the energy centrobaric correction method (ECCM) which is a practical and effective method used in rotating mechanical fault diagnosis and which resolves the shortcoming of FFT and can provide high accuracy estimate of frequency, amplitude and phase. In the present work, the modal responses of damaged simply supported beams with auxiliary mass are computed using the finite element method (FEM). The graphical plots of the natural frequencies calculated by SCCM versus axial location of auxiliary mass are obtained. However, it is difficult to locate the crack directly from the curve of natural frequencies. A simple and fast method, the derivatives of natural frequency curve, is proposed in the paper which can provide crack information for damage detection of beam-like structures. The efficiency and practicability of the proposed method is illustrated via numerical

  1. Gas chromatographic/mass spectrometric determination of carbon isotope composition in unpurified samples: methamphetamine example.

    Science.gov (United States)

    Low, I A; Liu, R H; Legendre, M G; Piotrowski, E G; Furner, R L

    1986-10-01

    A gas chromatograph/quadrupole mass spectrometer system, operated in electron impact/selected ion monitoring mode, is used to determine the intensity ratio of the m/z 59 and the m/z 58 ions of the [C3H8N]+ fragment derived from methamphetamine samples synthesized with varying amounts of 13C-labeled methylamine. Crude products are introduced into the gas chromatograph without prior cleanup. The ratios measured were in excellent agreement with those calculated. A change in 0.25% use of 13C-methylamine is sufficient for product differentiation. The feasibility of using isotope labeling and subsequent mass spectrometric isotope ratio measurement as the basis of a compound tracing mechanism is discussed. Specifically, if methamphetamine samples manufactured from legal sources are asked to incorporate distinct 13C compositions, their sources can be traced when samples are diverted into illegal channels. Samples derived from illicit preparations can also be traced if the manufacturers of a precursor (methylamine in this case) incorporate distinct 13C compositions in their products.

  2. Alterations of body mass index and body composition in atomic bomb survivors.

    Science.gov (United States)

    Tatsukawa, Y; Misumi, M; Yamada, M; Masunari, N; Oyama, H; Nakanishi, S; Fukunaga, M; Fujiwara, S

    2013-08-01

    Obesity, underweight, sarcopenia and excess accumulation of abdominal fat are associated with a risk of death and adverse health outcomes. Our aim was to determine whether body mass index (BMI) and body composition, assessed with dual-energy X-ray absorptiometry (DXA), are associated with radiation exposure among atomic bomb (A-bomb) survivors. This was a cross-sectional study conducted in the Adult Health Study of the Radiation Effects Research Foundation. We examined 2686 subjects (834 men and 1852 women), aged 48-89 years (0-40 years at A-bomb exposure), for BMI analysis. Among them, 550 men and 1179 women underwent DXA in 1994-1996 and were eligible for a body composition study. After being adjusted for age and other potential confounding factors, A-bomb radiation dose was associated significantly and negatively with BMI in both sexes (P=0.01 in men, P=0.03 in women) and appendicular lean mass (Pbomb radiation exposure. We will need to conduct further studies to evaluate whether these alterations affect health status.

  3. Experimental Assessment of the Mass of Ash Residue During the Burning of Droplets of a Composite Liquid Fuel

    Science.gov (United States)

    Glushkov, D. O.; Zakharevich, A. V.; Strizhak, P. A.; Syrodoi, S. V.

    2018-05-01

    An experimental study has been made of the regularities of burning of single droplets of typical compositions of a composite liquid fuel during the heating by an air flow with a varied temperature (600-900 K). As the basic components of the compositions of the composite liquid fuel, use was made of the: waste of processing (filter cakes) of bituminous coals of ranks K, C, and T, waste motor, turbine, and transformer oils, process mixture of mazut and oil, heavy crude, and plasticizer. The weight fraction of a liquid combustible component (petroleum) product) ranged within 0-15%. Consideration has been given to droplets of a composite liquid fuel with dimensions (radius) of 0.5 to 2 mm. Conditions of low-temperature initiation of combustion to ensure a minimum possible mass of solid incombustible residue have been determined. Petroleum products have been singled out whose addition to the composition of the composite liquid fuel tends to increase the ash mass (compared to the corresponding composition without a liquid combustible component). Approximation dependences have been obtained which permit predicting the influence of the concentration of the liquid petroleum product as part of the composite liquid fuel on the ash-residue mass.

  4. The chemical composition and mineralogy of meteorites measured with very high spatial resolution by a laser mass spectrometer for in situ planetary research

    Science.gov (United States)

    Brigitte Neuland, Maike; Mezger, Klaus; Tulej, Marek; Frey, Samira; Riedo, Andreas; Wurz, Peter; Wiesendanger, Reto

    2017-04-01

    The knowledge of the chemical composition of moons, comets, asteroids or other planetary bodies is of particular importance for the investigation of the origin and evolution of the Solar System. High resolution in situ studies on planetary surfaces can yield important information on surface heterogeneity, basic grain mineralogy and chemical composition of surface and subsurface. In turn, these data are the basis for our understanding of the physical and chemical processes which led to the formation and alteration of planetary material [1]. We investigated samples of Allende and Sayh al Uhaymir with a highly miniaturised laser mass spectrometer (LMS), which has been designed and built for in situ space research [2,3]. Both meteorite samples were investigated with a spatial resolution of about 10μm in lateral direction. The high sensitivity and high dynamic range of the LMS allow for quantitative measurements of the abundances of the rock-forming and minor and trace elements with high accuracy [4]. From the data, the modal mineralogy of micrometre-sized chondrules can be inferred [5], conclusions about the condensation sequence of the material are possible and the sensitivity for radiogenic elements allows for dating analyses of the investigated material. We measured the composition of various chondrules in Allende, offering valuable clues about the condensation sequence of the different components of the meteorite. We explicitly investigated the chemical composition and heterogeneity of the Allende matrix with an accuracy that cannot be reached by the mechanical analysis methods that were and are widely used in meteoritic research. We demonstrate the capabilities for dating analyses with the LMS. By applying the U-Th-dating method, the age of the SaU169 sample could be determined. Our analyses show that the LMS would be a suitable instrument for high-quality quantitative chemical composition measurements on the surface of a celestial body like a planet, moon or

  5. Mass

    International Nuclear Information System (INIS)

    Quigg, Chris

    2007-01-01

    In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.

  6. Bayesian Integration and Classification of Composition C-4 Plastic Explosives Based on Time-of-Flight-Secondary Ion Mass Spectrometry and Laser Ablation-Inductively Coupled Plasma Mass Spectrometry.

    Science.gov (United States)

    Mahoney, Christine M; Kelly, Ryan T; Alexander, Liz; Newburn, Matt; Bader, Sydney; Ewing, Robert G; Fahey, Albert J; Atkinson, David A; Beagley, Nathaniel

    2016-04-05

    Time-of-flight-secondary ion mass spectrometry (TOF-SIMS) and laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) were used for characterization and identification of unique signatures from a series of 18 Composition C-4 plastic explosives. The samples were obtained from various commercial and military sources around the country. Positive and negative ion TOF-SIMS data were acquired directly from the C-4 residue on Si surfaces, where the positive ion mass spectra obtained were consistent with the major composition of organic additives, and the negative ion mass spectra were more consistent with explosive content in the C-4 samples. Each series of mass spectra was subjected to partial least squares-discriminant analysis (PLS-DA), a multivariate statistical analysis approach which serves to first find the areas of maximum variance within different classes of C-4 and subsequently to classify unknown samples based on correlations between the unknown data set and the original data set (often referred to as a training data set). This method was able to successfully classify test samples of C-4, though with a limited degree of certainty. The classification accuracy of the method was further improved by integrating the positive and negative ion data using a Bayesian approach. The TOF-SIMS data was combined with a second analytical method, LA-ICPMS, which was used to analyze elemental signatures in the C-4. The integrated data were able to classify test samples with a high degree of certainty. Results indicate that this Bayesian integrated approach constitutes a robust classification method that should be employable even in dirty samples collected in the field.

  7. Mass variation effect of teki grass (cyperus rotundus) composite against tensile strength and density

    Science.gov (United States)

    Rafiq Yanhar, Muhammad; Haris Nasution, A.

    2018-05-01

    The primary purpose of this study is to determine the tensile strength using ASTM D638 - 02a type IVB and density of teki grass (Cyperus rotundus) composite. The production process is carried out by mass variation of 2 gr, 3 gr, and 4 gr. Hand lay-up method with three repetitions is applied. Teki grass is chosen because it is easy to find and has some advantages biodegradable, harmless to health, available in large quantities, and cost-efficient. The test result showed the largest tensile strength is 21,61 MPa at 2-gram mass fiber. Fiber addition to 3 gram and 4-gram cause tensile strength decreases to 18,51 MPa and 11,65 MPa. It happens because the fibers are random and spread in all directions, so many fibers are undirectional with the tensile force. Beside that fibers addition made matrix volume reduced and a bond between fiber and matrix decreases, finally make fiber unable to hold the tensile force properly. It is recommended to use another type of ASTM D638 - 02a which has a larger narrow section like type I (13 mm) and type III (19mm) so specimens are not broken when removed from the mold, and there isn’t any decrease in tensile strength.Density test showed that fiber mass does not significantly affect the density.

  8. Insights into relationships between body mass, composition and bone: findings in elite rugby players.

    Science.gov (United States)

    Hind, Karen; Gannon, Lisa; Brightmore, Amy; Beck, Belinda

    2015-01-01

    Recent reports indicate that bone strength is not proportional to body weight in obese populations. Elite rugby players have a similar body mass index (BMI) to obese individuals but differ markedly with low body fat, high lean mass, and frequent skeletal exposure to loading through weight-bearing exercise. The purpose of this study was to determine relationships between body weight, composition, and bone strength in male rugby players characterized by high BMI and high lean mass. Fifty-two elite male rugby players and 32 nonathletic, age-matched controls differing in BMI (30.2 ± 3.2 vs 24.1 ± 2.1 kg/m²; p = 0.02) received 1 total body and one total hip dual-energy X-ray absorptiometry scan. Hip structural analysis of the proximal femur was used to determine bone mineral density (BMD) and cross-sectional bone geometry. Multiple linear regression was computed to identify independent variables associated with total hip and femoral neck BMD and hip structural analysis-derived bone geometry parameters. Analysis of covariance was used to explore differences between groups. Further comparisons between groups were performed after normalizing parameters to body weight and to lean mass. There was a trend for a positive fat-bone relationship in rugby players, and a negative relationship in controls, although neither reached statistical significance. Correlations with lean mass were stronger for bone geometry (r(2): 0.408-0.520) than for BMD (r(2): 0.267-0.293). Relative to body weight, BMD was 6.7% lower in rugby players than controls (p Rugby players were heavier than controls, with greater lean mass and BMD (p rugby players (p rugby players was reduced in proportion to body weight and lean mass. However, their superior bone geometry suggests that overall bone strength may be adequate for loading demands. Fat-bone interactions in athletes engaged in high-impact sports require further exploration. Copyright © 2015. Published by Elsevier Inc.

  9. Sources and composition of submicron organic mass in marine aerosol particles

    Science.gov (United States)

    Frossard, Amanda A.; Russell, Lynn M.; Burrows, Susannah M.; Elliott, Scott M.; Bates, Timothy S.; Quinn, Patricia K.

    2014-11-01

    The sources and composition of atmospheric marine aerosol particles (aMA) have been investigated with a range of physical and chemical measurements from open-ocean research cruises. This study uses the characteristic functional group composition (from Fourier transform infrared spectroscopy) of aMA from five ocean regions to show the following: (i) The organic functional group composition of aMA that can be identified as mainly atmospheric primary marine (ocean derived) aerosol particles (aPMA) is 65 ± 12% hydroxyl, 21 ± 9% alkane, 6 ± 6% amine, and 7 ± 8% carboxylic acid functional groups. Contributions from photochemical reactions add carboxylic acid groups (15%-25%), shipping effluent in seawater and ship emissions add additional alkane groups (up to 70%), and coastal or continental emissions mix in alkane and carboxylic acid groups. (ii) The organic composition of aPMA is nearly identical to model-generated primary marine aerosol particles from bubbled seawater (gPMA, which has 55 ± 14% hydroxyl, 32 ± 14% alkane, and 13 ± 3% amine functional groups), indicating that its overall functional group composition is the direct consequence of the organic constituents of the seawater source. (iii) While the seawater organic functional group composition was nearly invariant across all three ocean regions studied and the ratio of organic carbon to sodium (OC/Na+) in the gPMA remained nearly constant over a broad range of chlorophyll a concentrations, the gPMA alkane group fraction appeared to increase with chlorophyll a concentrations (r = 0.66). gPMA from productive seawater had a larger fraction of alkane functional groups (42 ± 9%) compared to gPMA from nonproductive seawater (22 ± 10%), perhaps due to the presence of surfactants in productive seawater that stabilize the bubble film and lead to preferential drainage of the more soluble (lower alkane group fraction) organic components. gPMA has a hydroxyl group absorption peak location characteristic of

  10. Association between body composition and body mass index in young Japanese women.

    Science.gov (United States)

    Yamagishi, Hiroyuki; Kitano, Takao; Kuchiki, Tsutomu; Okazaki, Hideki; Shibata, Shigeo

    2002-06-01

    The National Nutrition Survey of Japan indicated a trend toward a decreasing body mass index (BMI; kg/m2) among young Japanese women. Current studies suggest that not-high BMI often does not correlate with not-high body fat percentage. Recently, the classification of BMI in adult Asians was proposed by the International Obesity Task Force. The addition of an "at risk of overweight" category, BMI as 23.0-24.9, was intended to prevent chronic diseases. We investigated the association between body fat percentage (BF%) and BMI to evaluate the screening performance of BMI focused on individual preventive medicine. The subjects consisted of 605 female college students. The subjects' ages (y), heights (cm), body weights (kg), BMIs, and BF percents with underwater weighing expressed as the means +/- SD were 19.6 +/- 0.5, 158.7 +/- 5.6, 53.8 +/- 7.2, 21.3 +/- 2.4, and 24.9 +/- 4.9, respectively. We defined high BF% as +/- 85th percentile of BF% (29.8%). High-BF% individuals are often not classified into BMI > or = 23.0 because their BMI readings are very broad (18.4-31.7). In comparison to the screening performances (specificity and sensitivity), BMI > or = 23.0 (85.3% and 52.1%, respectively), rather than BMI > or = 25.0 (96.7% and 29.8%, respectively), is recommended for the mass evaluation of fatness. For this reason, the BMI "at risk of overweight" category is characterized as the threshold of increasing the appearance ratio of high-BF% individuals. In conclusion, the BMI > or = 25.0 kg/m2 category is determined as high BF%, regardless of body composition measurement for mass evaluation as a result of quite high specificity. Even so, body composition measurement is necessitated by the individual evaluation of fatness focused on preventive medicine because BMI performed a poor representation of body composition, especially BMI < 25.0 kg/m2 individuals.

  11. Compositional characterisation of rare earth magnet materials by glow discharge quadrupole mass spectrometry

    International Nuclear Information System (INIS)

    Reddy, M.A.; Shekhar, R.; Kumar, Sunil Jai

    2014-01-01

    In this paper, glow discharge quadrupole mass spectrometric (GD-QMS) studies on Sm-Pr-Co compound magnetic materials are reported. The composition of these magnetic materials produced from different manufacturing routes (imported, indigenous) was determined. The results are compared with the results obtained by an alternative analytic technique, inductively coupled plasma atomic emission spectrometry (ICP-AES), after complete dissolution of the material in the appropriate acids. For perfectly homogeneous material both the wet chemical method and direct solid analysis method should give the same result. A close examination of both the results indicates that for imported materials the values obtained by wet chemical method and direct solid method are in close agreement. This indicates that the imported (solid) material is highly homogeneous. For indigenous materials, it shows a large difference in the values of Co and Sm. This reveals that the solid material prepared is not as homogenous as the imported materials

  12. Field desorption mass spectroscopy monitoring of changes in hydrocarbon type composition during petroleum biodegradation

    International Nuclear Information System (INIS)

    Huesemann, M.H.

    1995-01-01

    A comprehensive petroleum hydrocarbon characterization procedure involving group type separation, boiling point distribution, and hydrocarbon typing by field desorption mass spectroscopy (FDMS) has been developed to quantify changes in hydrocarbon type composition during bioremediation of petroleum-contaminated soils. FDMS is able to quantify the concentration of hundreds of specific hydrocarbon types based on their respective hydrogen deficiency (z-number) and molecular weight (carbon number). Analytical results from two bioremediation experiments involving soil contaminated with crude oil and motor oil indicate that alkanes and two-ring saturates (naphthenes) were readily biodegradable. In addition, low-molecular-weight hydrocarbons generally were biodegraded to a larger extent than those of high molecular weight. More importantly, it was found that the extent of biodegradation of specific hydrocarbon types was comparable between treatments and appeared to be unaffected by the petroleum contaminant source, soil type, or experimental conditions. It was therefore concluded that in these studies the extent of total petroleum hydrocarbon (TPH) biodegradation is primarily affected by the molecular composition of the petroleum hydrocarbons present in the contaminated soil

  13. Derivation of mass relations for composite W* and Z* from effective Lagrangian approach

    International Nuclear Information System (INIS)

    Yasue, Masaki; Oneda, Sadao.

    1985-04-01

    In an effective-Lagrangian model with gauge bosons (W,Z,γ) and their neighboring spin J=1 composites (W*,Z*), we find relations among their masses, m sub(W), m sub(Z), m sub(W*) and m sub(Z*): m sub(W) m sub(W*) = cos theta m sub(Z) m sub(Z*) (as a generalization of m sub(W) = cos theta m sub(Z)) and m sub(W) 2 + m sub(W*) 2 + tan 2 theta m sub(W0) 2 = m sub(Z) 2 + m sub(Z*) 2 with m sub(W0) being the mass of W in the standard model provided that the system respects the SU(2) sub(L) x U(1) sub(Y) symmetry. W* and Z* are taken as the lowest-lying excited states belonging to an SU(2) sub(L)-triplet in the symmetric limit. The existence of W* coupling to the V-A current modifies the relation between G sub(F) and M sub(W) and that of Z* generates a new interaction of the (Jsup(em)) 2 -type as well as the deviation of sin theta sub(W) observed at low energies from the mixing angle sin theta in neutral-current interactions. (author)

  14. Chemical composition measurements of the atmosphere of Jupiter with the Galileo Probe mass spectrometer

    Science.gov (United States)

    Niemann, H. B.; Atreya, S. K.; Carignan, G. R.; Donahue, T. M.; Haberman, J. A.; Harpold, D. N.; Hartle, R. E.; Hunten, D. M.; Kasprzak, W. T.; Mahaffy, P. R.; hide

    1998-01-01

    The Galileo Probe entered the atmosphere of Jupiter on December 7, 1995. Measurements of the chemical and isotopic composition of the Jovian atmosphere were obtained by the mass spectrometer during the descent over the 0.5 to 21 bar pressure region over a time period of approximately 1 hour. The sampling was either of atmospheric gases directly introduced into the ion source of the mass spectrometer through capillary leaks or of gas, which had been chemically processed to enhance the sensitivity of the measurement to trace species or noble gases. The analysis of this data set continues to be refined based on supporting laboratory studies on an engineering unit. The mixing ratios of the major constituents of the atmosphere hydrogen and helium have been determined as well as mixing ratios or upper limits for several less abundant species including: methane, water, ammonia, ethane, ethylene, propane, hydrogen sulfide, neon, argon, krypton, and xenon. Analysis also suggests the presence of trace levels of other 3 and 4 carbon hydrocarbons, or carbon and nitrogen containing species, phosphine, hydrogen chloride, and of benzene. The data set also allows upper limits to be set for many species of interest which were not detected. Isotope ratios were measured for 3He/4He, D/H, 13C/12C, 20Ne/22Ne, 38Ar/36Ar and for isotopes of both Kr and Xe.

  15. Fragments emission from light mass composite nuclei within collective clusterization mechanism

    International Nuclear Information System (INIS)

    Singh, BirBikram

    2016-01-01

    Based on the quantum mechanical fragmentation theory (QMFT) the dynamical cluster decay model (DCM) has been developed by Gupta and Collaborators to study the decay of hot and rotating compound systems. Number of compound nuclei (CN) in different mass regions have been studied quite extensively while taking into consideration nuclear structure effects in the same. It is quite relevant to mention here that in the binary decay of CN nuclear structure effects comes into picture, within DCM, via preformation probability P_0 of the complimentary fragments before penetrating the potential barrier between them with certain probability P . It is interesting to note here that the statistical models treat various decay modes of the CN on different footing contrary to the DCM. In very light mass region the decay of number of composite systems "2"0","2"1","2"2Ne*, "2"6"-"2"9Al, "2"8Si, "3"1P, "3"2S, "3"9K and "4"0Ca*, formed in low energy heavy ion reactions, have been investigated for different reaction mechanisms particularly fusion-fission (FF) and deep inelastic orbiting (DIO) from equilibrated and non-equilibrated compound nucleus processes, respectively

  16. Determination of elemental composition of metals using ambient organic mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Shiea, Christopher [Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, 100 Shih-Chuan 1st Rd, Kaohsiung 807, Taiwan (China); Huang, Yeou-Lih [Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, 100 Shih-Chuan 1st Rd, Kaohsiung 807, Taiwan (China); Department of Chemistry, National Sun Yat-Sen University, 70 Lien-Hai Rd, Kaohsiung 804, Taiwan (China); Cheng, Sy-Chyi; Chen, Yi-Lun [Department of Chemistry, National Sun Yat-Sen University, 70 Lien-Hai Rd, Kaohsiung 804, Taiwan (China); Shiea, Jentaie, E-mail: jetea@mail.nsysu.edu.tw [Department of Chemistry, National Sun Yat-Sen University, 70 Lien-Hai Rd, Kaohsiung 804, Taiwan (China); Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, 100 Shih-Chuan 1st Rd, Kaohsiung 807, Taiwan (China)

    2017-05-22

    Conventional inorganic mass spectrometric (MS) analysis of metals can require time-consuming and tedious sample preparation. We thus report the novel and direct characterization of metals in solid samples using an organic MS technique known as electrospray laser desorption ionization mass spectrometry (ELDI/MS). No sample pretreatment was needed, and results were rapidly obtained due to the ambient and laser-based nature of ELDI/MS. Metals from samples were desorbed and ionized by laser irradiation, after which they reacted with EDTA and then post-ionized and detected as metal-EDTA complexes. Aluminum, copper, iron, lead, nickel, and zinc from plates, foils, and coins were characterized in seconds. This study demonstrates that an ESI/MS system can be easily modified to analyze metal elements in solids by involving a chelating agent, indicating a potentially promising development in MS towards the analysis of metals using organic MS. - Highlights: • “Organic MS” was utilized as “inorganic MS” to detect metal ions in solid samples. • Element ions desorbed by laser irradiation rapidly reacted with a chelating reagent before they were detected by MS. • Elemental composition of metals was determined by this “Organic MS” method.

  17. Determination of elemental composition of metals using ambient organic mass spectrometry

    International Nuclear Information System (INIS)

    Shiea, Christopher; Huang, Yeou-Lih; Cheng, Sy-Chyi; Chen, Yi-Lun; Shiea, Jentaie

    2017-01-01

    Conventional inorganic mass spectrometric (MS) analysis of metals can require time-consuming and tedious sample preparation. We thus report the novel and direct characterization of metals in solid samples using an organic MS technique known as electrospray laser desorption ionization mass spectrometry (ELDI/MS). No sample pretreatment was needed, and results were rapidly obtained due to the ambient and laser-based nature of ELDI/MS. Metals from samples were desorbed and ionized by laser irradiation, after which they reacted with EDTA and then post-ionized and detected as metal-EDTA complexes. Aluminum, copper, iron, lead, nickel, and zinc from plates, foils, and coins were characterized in seconds. This study demonstrates that an ESI/MS system can be easily modified to analyze metal elements in solids by involving a chelating agent, indicating a potentially promising development in MS towards the analysis of metals using organic MS. - Highlights: • “Organic MS” was utilized as “inorganic MS” to detect metal ions in solid samples. • Element ions desorbed by laser irradiation rapidly reacted with a chelating reagent before they were detected by MS. • Elemental composition of metals was determined by this “Organic MS” method.

  18. Mass of organs and composition of the body of Japanese Reference Man

    International Nuclear Information System (INIS)

    Tanaka, Gi-ichiro

    1990-01-01

    Reference Man as defined and described in ICRP Publication 23 is in the process of major revision, with an emphasis on the age and sex, and characteristics of non-European populations. Japanese Reference Man (or Woman) is to be defined as the subject, normal and healthy, 20 to 30 years of age, who inhabits in Japan and live on the 'standard diet'. He (or she) is a Mongoloid in race, and 170 (or 160) cm in height, and 60 (or 51) kg in weight. Physical properties such as masses of 114 organs, tissues and components, and their specific gravities of Japanese Reference Male are given. Body composition or body fat, LBM, skeleton, soft lean body mass (SLBM), body water, blood, muscle, ash, protein and specific gravity were also given as well as body surface. These data are primarily based on the data obtained for normal Japanese, and, where data unavailable, they were derived from ICRP Reference Man data by using a new concept of SLBM. Red bone marrow was estimated to be 1,000g as compared to 1,500g in Reference Man. Body fat was obtained by using Nagamine's equations, which showed a recent slight tendency of obesity. In conclusion, the present data for Japanese Reference Man could be used in designing appropriate phantoms, mathematical and real, for Japanese. Japanese Reference Man will also provide a basis for Asian Reference Man, which, in principle, should be consistent with ICRP concepts of Reference Man. (author)

  19. Stable carbon isotopic composition of gasolines determined by isotope ratio monitoring gas chromatography mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Smallwood, B.J.; Philp, R.P.; Allen, J.D. [University of Oklahoma, Norman, OK (United States). School of Geology and Geophysics

    2002-07-01

    A large number of underground gasoline storage facilities in the United States continuously leak gasoline into the subsurface, which makes gasoline a major groundwater contaminant. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) are used currently to characterize contaminated groundwater and soils. Correlations of contaminants with suspected source(s) are extremely difficult by these techniques because many gasolines have similar hydrocarbon distributions. The present study applied the technique of isotope ratio monitoring gas chromatography-mass spectrometry (irmGC-MS) to 19 gasoline samples from different areas of the USA. This allows a much better correlation of gasoline contaminants to source. Data obtained indicate a wide range of {sup {delta}}{sup 13}C values for 16 ubiquitous compounds in the gasolines. The majority of samples could be distinguished from each other on the basis of {sup {delta}}{sup 13}C hydrocarbon composition. The oxygenated additive methyl tertiary butyl ether (MTBE) was present in ten of the gasolines analyzed, and had a relatively narrow range of {sup {delta}}{sup 13}C values (-30.4 to -28.3 per mille). Preliminary investigations were also made to determine the extent of carbon isotopic fractionation after simple water washing and evaporation experiments. Results indicate that the majority of compounds did not undergo significant carbon isotopic fractionation as a result of these processes. (author)

  20. Effective mass of the four-flux composite fermion at ν=1/4

    International Nuclear Information System (INIS)

    Pan, W.; Stormer, H. L.; Tsui, D. C.; Pfeiffer, L. N.; Baldwin, K. W.; West, K. W.

    2000-01-01

    We have measured the effective mass (m * ) of the four flux composite fermion at Landau-level filling factor ν=1/4 ( 4 CF), using the activation energy gaps at the fractional quantum Hall effect states ν=2/7, 3/11, and 4/15 and the temperature dependence of the Shubnikov-de Haas (SdH) oscillations around ν=1/4. We find that the energy gaps show a linear dependence on the effective magnetic field B eff (≡B-B ν=1/4 ), and from this linear dependence we obtain m * =1.0m e and a disorder broadening Γ∼1 K for a sample of density n=0.87x10 11 cm -2 . The m * deduced from the temperature dependence of the SdH effect shows large differences for ν>1/4 and ν 1/4, m * ∼1.0m e . It scales as √(B ν ) with the mass derived from the data around ν=1/2 and shows an increase in m * as ν→1/4, resembling the findings around ν=1/2. For ν * increases rapidly with increasing B eff and can be described by m * /m e =-3.3+5.7B eff . This anomalous dependence on B eff is precursory to the formation of the insulating phase at still lower filling. (c) 2000 The American Physical Society

  1. High-precision measurements of seawater Pb isotope compositions by double spike thermal ionization mass spectrometry.

    Science.gov (United States)

    Paul, Maxence; Bridgestock, Luke; Rehkämper, Mark; van DeFlierdt, Tina; Weiss, Dominik

    2015-03-10

    A new method for the determination of seawater Pb isotope compositions and concentrations was developed, which combines and optimizes previously published protocols for the separation and isotopic analysis of this element. For isotopic analysis, the procedure involves initial separation of Pb from 1 to 2L of seawater by co-precipitation with Mg hydroxide and further purification by a two stage anion exchange procedure. The Pb isotope measurements are subsequently carried out by thermal ionization mass spectrometry using a (207)Pb-(204)Pb double spike for correction of instrumental mass fractionation. These methods are associated with a total procedural Pb blank of 28±21 pg (1sd) and typical Pb recoveries of 40-60%. The Pb concentrations are determined by isotope dilution (ID) on 50 mL of seawater, using a simplified version of above methods. Analyses of multiple aliquots of six seawater samples yield a reproducibility of about ±1 to ±10% (1sd) for Pb concentrations of between 7 and 50 pmol/kg, where precision was primarily limited by the uncertainty of the blank correction (12±4 pg; 1sd). For the Pb isotope analyses, typical reproducibilities (±2sd) of 700-1500 ppm and 1000-2000 ppm were achieved for (207)Pb/(206)Pb, (208)Pb/(206)Pb and (206)Pb/(204)Pb, (207)Pb/(204)Pb, (208)Pb/(204)Pb, respectively. These results are superior to literature data that were obtained using plasma source mass spectrometry and they are at least a factor of five more precise for ratios involving the minor (204)Pb isotope. Both Pb concentration and isotope data, furthermore, show good agreement with published results for two seawater intercomparison samples of the GEOTRACES program. Finally, the new methods were applied to a seawater depth profile from the eastern South Atlantic. Both Pb contents and isotope compositions display a smooth evolution with depth, and no obvious outliers. Compared to previous Pb isotope data for seawater, the (206)Pb/(204)Pb ratios are well correlated

  2. SLUDGE MASS REDUCTION: PRIMARY COMPOSITIONAL FACTORS THAT INFLUENCE MELT RATE FOR FUTURE SLUDGE BATCH PROJECTIONS

    International Nuclear Information System (INIS)

    Newell, J; Miller, D; Stone, M; Pickenheim, B

    2008-01-01

    The Savannah River National Laboratory (SRNL) was tasked to provide an assessment of the downstream impacts to the Defense Waste Processing Facility (DWPF) of decisions regarding the implementation of Al-dissolution to support sludge mass reduction and processing. Based on future sludge batch compositional projections from the Liquid Waste Organization's (LWO) sludge batch plan, assessments have been made with respect to the ability to maintain comparable projected operating windows for sludges with and without Al-dissolution. As part of that previous assessment, candidate frits were identified to provide insight into melt rate for average sludge batches representing with and without Al-dissolution flowsheets. Initial melt rate studies using the melt rate furnace (MRF) were performed using five frits each for Cluster 2 and Cluster 4 compositions representing average without and with Al-dissolution. It was determined, however, that the REDOX endpoint (Fe 2+ /ΣFe for the glass) for Clusters 2 and 4 resulted in an overly oxidized feed which negatively affected the initial melt rate tests. After the sludge was adjusted to a more reduced state, additional testing was performed with frits that contained both high and low concentrations of sodium and boron oxides. These frits were selected strictly based on the ability to ascertain compositional trends in melt rate and did not necessarily apply to any acceptability criteria for DWPF processing. The melt rate data are in general agreement with historical trends observed at SRNL and during processing of SB3 (Sludge Batch 3)and SB4 in DWPF. When MAR acceptability criteria were applied, Frit 510 was seen to have the highest melt rate at 0.67 in/hr for Cluster 2 (without Al-dissolution), which is compositionally similar to SB4. For Cluster 4 (with Al-dissolution), which is compositionally similar to SB3, Frit 418 had the highest melt rate at 0.63 in/hr. Based on this data, there appears to be a slight advantage of the Frit

  3. Perfusion pattern and time of vascularisation with CEUS increase accuracy in differentiating between benign and malignant tumours in 216 musculoskeletal soft tissue masses

    Energy Technology Data Exchange (ETDEWEB)

    De Marchi, Armanda, E-mail: armanda.demarchi@tiscali.it [Department of Imaging, Azienda Ospedaliera Città della Salute e della Scienza, CTO Hospital, Via Zuretti 29, 10126 Torino (Italy); Prever, Elena Brach del, E-mail: elena.brach@unito.it [Department of OrthopaedicOncology and ReconstructiveSurgery, Azienda Ospedaliero Universitaria Città della Salute e della Scienza, CTO Hospital, Via Zuretti 29, 10126 Torino (Italy); Cavallo, Franco, E-mail: franco.cavallo@unito.it [Department of Public health and Paediatrics, University of Turin, Via Santena 5-bis, 10126 Torino (Italy); Pozza, Simona, E-mail: simona.pozza@tin.it [Department of Imaging, Azienda Ospedaliera Città della Salute e della Scienza, CTO Hospital, Via Zuretti 29, 10126 Torino (Italy); Linari, Alessandra, E-mail: linaralessandra@libero.it [Department of Pathology, Azienda Ospedaliero Universitaria Città della Salute e della Scienza, Regina Margherita Hospital, Piazza Polonia, 10126 Torino (Italy); Lombardo, Paolo, E-mail: pao.lombardo82@gmail.com [Department of DiagnosticImaging and Radiotherapy of the University of Turin, Azienda Ospedaliero-Universitaria Città della Salute e della Scienza di Torino, Via Genova 3, 10126 Torino (Italy); Comandone, Alessandro, E-mail: alessandro.comandone@gradenigo.it [Department of Oncology, Gradenigo Hospital, Corso Regina Margherita, 8/10.10153 Torino (Italy); Piana, Raimondo, E-mail: raimondo.piana@libero.it [Department of OrthopaedicOncology and ReconstructiveSurgery, Azienda Ospedaliero Universitaria Città della Salute e della Scienza, CTO Hospital, Via Zuretti 29, 10126 Torino (Italy); Faletti, Carlo [Department of Imaging, Azienda Ospedaliera Città della Salute e della Scienza, CTO Hospital, Via Zuretti 29, 10126 Torino (Italy)

    2015-01-15

    Introduction: Musculoskeletal Soft Tissue Tumours (STT) are frequent heterogeneous lesions. Guidelines consider a mass larger than 5 cm and deep with respect to the deep fascia potentially malignant. Contrast Enhanced Ultrasound (CEUS) can detect both vascularity and tumour neoangiogenesis. We hypothesised that perfusion patterns and vascularisation time could improve the accuracy of CEUS in discriminating malignant tumours from benign lesions. Materials and methods: 216 STT were studied: 40% benign lesions, 60% malignant tumours, 56% in the lower limbs. Seven CEUS perfusion patterns and three types of vascularisation (arterial-venous uptake, absence of uptake) were applied. Accuracy was evaluated by comparing imaging with the histological diagnosis. Univariate and multivariate analysis, Chi-square test and t-test for independent variables were applied; significance was set at p < 0.05 level, 95% computed CI. Results: CEUS pattern 6 (inhomogeneous perfusion), arterial uptake and location in the lower limb were associated with high risk of malignancy. CEUS pattern has PPV 77%, rapidity of vascularisation PPV 69%; location in the limbs is the most sensitive indicator, but NPV 52%, PPV 65%. The combination of CEUS-pattern and vascularisation has 74% PPV, 60% NPV, 70% sensitivity. No correlation with size and location in relation to the deep fascia was found. Conclusion: US with CEUS qualitative analysis could be an accurate technique to identify potentially malignant STT, for which second line imaging and biopsy are indicated in Referral Centers. Intense inhomogeneous enhancement with avascular areas and rapid vascularisation time could be useful in discriminating benign from malignant SST, overall when the lower limbs are involved.

  4. Functional group composition of ambient and source organic aerosols determined by tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dron, J.; El Haddad, I.; Temime-Roussel, B.; Wortham, H.; Marchand, N. [Univ Aix Marseille, CNRS, Lab Chim Provence, Equipe Instrumentat and React Atmospher, UMR 6264, F-13331 Marseille 3 (France); Jaffrezo, J.L. [Univ Grenoble 1, CNRS, UMR 5183, Lab Glaciol and Geophys Environm, F-38402 St Martin Dheres (France)

    2010-07-01

    The functional group composition of various organic aerosols (OA) is investigated using a recently developed analytical approach based on atmospheric pressure chemical ionisation-tandem mass spectrometry (APCIMS/MS). The determinations of three functional groups contents are performed quantitatively by neutral loss (carboxylic and carbonyl groups, R-COOH and R-CO-R' respectively) and precursor ion (nitro groups, R-NO{sub 2}) scanning modes of a tandem mass spectrometer. Major organic aerosol sources are studied: vehicular emission and wood combustion for primary aerosol sources; and a secondary organic aerosol (SOA) produced through photooxidation of o-xylene. The results reveal significant differences in the functional group contents of these source aerosols. The laboratory generated SOA is dominated by carbonyls while carboxylics are preponderate in the wood combustion particles. On the other hand, vehicular emissions are characterised by a strong nitro content. The total amount of the three functional groups accounts for 1.7% (vehicular) to 13.5% (o-xylene photooxidation) of the organic carbon. Diagnostic functional group ratios are then used to tentatively discriminate sources of particles collected in an urban background environment located in an Alpine valley (Chamonix, France) during a strong winter pollution event. The three functional groups under study account for a total functionalization rate of 2.2 to 3.8% of the organic carbon in this ambient aerosol, which is also dominated by carboxylic moieties. In this particular case study of a deep alpine valley during winter, we show that the nitro- and carbonyl-to-carboxylic diagnostic ratios can be a useful tool to discriminate sources. In these conditions, the total OA concentrations are highly dominated by wood combustion OA. This result is confirmed by an organic markers source apportionment approach which assess a wood burning organic carbon contribution of about 60%. Finally, examples of functional

  5. Functional group composition of ambient and source organic aerosols determined by tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    J. Dron

    2010-08-01

    Full Text Available The functional group composition of various organic aerosols (OA is investigated using a recently developed analytical approach based on atmospheric pressure chemical ionisation-tandem mass spectrometry (APCI-MS/MS. The determinations of three functional groups contents are performed quantitatively by neutral loss (carboxylic and carbonyl groups, R-COOH and R-CO-R´ respectively and precursor ion (nitro groups, R-NO2 scanning modes of a tandem mass spectrometer. Major organic aerosol sources are studied: vehicular emission and wood combustion for primary aerosol sources; and a secondary organic aerosol (SOA produced through photooxidation of o-xylene. The results reveal significant differences in the functional group contents of these source aerosols. The laboratory generated SOA is dominated by carbonyls while carboxylics are preponderate in the wood combustion particles. On the other hand, vehicular emissions are characterised by a strong nitro content. The total amount of the three functional groups accounts for 1.7% (vehicular to 13.5% (o-xylene photooxidation of the organic carbon. Diagnostic functional group ratios are then used to tentatively discriminate sources of particles collected in an urban background environment located in an Alpine valley (Chamonix, France during a strong winter pollution event. The three functional groups under study account for a total functionalisation rate of 2.2 to 3.8% of the organic carbon in this ambient aerosol, which is also dominated by carboxylic moieties. In this particular case study of a deep alpine valley during winter, we show that the nitro- and carbonyl-to-carboxylic diagnostic ratios can be a useful tool to discriminate sources. In these conditions, the total OA concentrations are highly dominated by wood combustion OA. This result is confirmed by an organic markers source apportionment approach which assess a wood burning organic carbon contribution of about 60

  6. The influence of different referencing methods on the accuracy of δ(13) C value measurement of ethanol fuel by gas chromatography/combustion/isotope ratio mass spectrometry.

    Science.gov (United States)

    Neves, Laura A; Rodrigues, Janaína M; Daroda, Romeu J; Silva, Paulo R M; Ferreira, Alexandre A; Aranda, Donato A G; Eberlin, Marcos N; Fasciotti, Maíra

    2015-11-15

    Brazil is the largest producer of sugar cane bioethanol in the world. Isotope ratio mass spectrometry (IRMS) is the technique of choice to certify the origin/raw materials for ethanol production, but the lack of certified reference materials (CRMs) for accurate measurements of δ(13) C values traceable to Vienna Pee Dee Belemnite (VPDB), the international zero point for (13) C/(12) C measurements, certified and compatible with gas chromatography (GC)/IRMS instruments may compromise the accuracy of δ(13) C determinations. We evaluated the influence of methods for the calibration and normalization of raw δ(13) C values of ethanol samples. Samples were analyzed by GC/C/IRMS using two different GC columns. Different substances were used as isotopic standards for the working gas calibration. The δ(13) C values obtained with the three methods of normalization were statistically compared with those obtained with elemental analyzer (EA)/IRMS, since the δ(13) C results obtained using EA are traceable to VPDB via the NBS 22 reference material. It was observed that both the isotopic reference material for CO2 calibration and the GC column have a major effect on the δ(13) C measurements, leading to a bias of almost 2-3 ‰ in the δ(13) C values. All three methods of normalization were equivalent in performance, enabling an improvement in the GC/C/IRMS accuracy, compared with the EA/IRMS reference values for the samples. All the methods of CO2 calibration, chromatography and normalization presented in this work demonstrated several sources of traceability and accuracy loss for the determination of δ(13) C values in ethanol fuel samples by GC/C/IRMS. This work has also shown the importance of using proper CRMs traceable to VPBD that should be compatible and certified using GC/C/IRMS, ideally in a wide range of δ(13) C values. This is important not only for bioethanol fuel samples, but also for many analytes commonly analyzed by IRMS. Copyright © 2015 John Wiley & Sons

  7. Partial verification bias and incorporation bias affected accuracy estimates of diagnostic studies for biomarkers that were part of an existing composite gold standard.

    Science.gov (United States)

    Karch, Annika; Koch, Armin; Zapf, Antonia; Zerr, Inga; Karch, André

    2016-10-01

    To investigate how choice of gold standard biases estimates of sensitivity and specificity in studies reassessing the diagnostic accuracy of biomarkers that are already part of a lifetime composite gold standard (CGS). We performed a simulation study based on the real-life example of the biomarker "protein 14-3-3" used for diagnosing Creutzfeldt-Jakob disease. Three different types of gold standard were compared: perfect gold standard "autopsy" (available in a small fraction only; prone to partial verification bias), lifetime CGS (including the biomarker under investigation; prone to incorporation bias), and "best available" gold standard (autopsy if available, otherwise CGS). Sensitivity was unbiased when comparing 14-3-3 with autopsy but overestimated when using CGS or "best available" gold standard. Specificity of 14-3-3 was underestimated in scenarios comparing 14-3-3 with autopsy (up to 24%). In contrast, overestimation (up to 20%) was observed for specificity compared with CGS; this could be reduced to 0-10% when using the "best available" gold standard. Choice of gold standard affects considerably estimates of diagnostic accuracy. Using the "best available" gold standard (autopsy where available, otherwise CGS) leads to valid estimates of specificity, whereas sensitivity is estimated best when tested against autopsy alone. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Accuracy of Percutaneous Core Biopsy in the Diagnosis of Small Renal Masses (≤4.0 cm: A Meta-analysis

    Directory of Open Access Journals (Sweden)

    Qiqi He

    2015-02-01

    Full Text Available Objective To use meta-analysis to determine the accuracy of percutaneous core needle biopsy in the diagnosis of small renal masses (SMRs≤4.0 cm. Materials and Methods Studies were identified by searching PubMed, Embase, and the Cochrane Library database up to March 2013. Two of the authors independently assessed the study quality using QUADAS-2 tool and extracted data that met the inclusion criteria. The sensitivity, specificity, likelihood ratios, diagnostic odds ratio (DOR and also summary receiver operating characteristic (SROC curve were investigated and draw. Deek’s funnel plot was used to evaluate the publication bias. Result A total of 9 studies with 788 patients (803 biopsies were included. Failed biopsies without repeated or aborted from follow-up/surgery result were excluded (232 patients and 353 biopsies. For all cases, the pooled sensitivity was 94.0% (95% CI: 91.0%, 95.0%, the pooled positive likelihood was 22.57 (95% CI: 9.20-55.34, the pooled negative likelihood was 0.09 (95% CI: 0.06-0.13, the pooled DOR was 296.52(95% CI: 99. 42-884.38. The area under the curve of SROC analysis was 0.959±0.0254. Conclusion Imaging-guided percutaneous core needle biopsy of small renal masses (SMRs≤4.0 cm is highly accurate to malignant tumor diagnosis with unknown metastatic status and could be offered to some patients after clinic judgment prior to surgical intervention consideration.

  9. Compositional Imprints in Density–Distance–Time: A Rocky Composition for Close-in Low-mass Exoplanets from the Location of the Valley of Evaporation

    Science.gov (United States)

    Jin, Sheng; Mordasini, Christoph

    2018-02-01

    We use an end-to-end model of planet formation, thermodynamic evolution, and atmospheric escape to investigate how the statistical imprints of evaporation depend on the bulk composition of planetary cores (rocky versus icy). We find that the population-wide imprints like the location of the “evaporation valley” in the distance–radius plane and the corresponding bimodal radius distribution clearly differ depending on the bulk composition of the cores. Comparison with the observed position of the valley suggests that close-in low-mass Kepler planets have a predominantly Earth-like rocky composition. Combined with the excess of period ratios outside of MMR, this suggests that low-mass Kepler planets formed inside of the water iceline but were still undergoing orbital migration. The core radius becomes visible for planets losing all primordial H/He. For planets in this “triangle of evaporation” in the distance–radius plane, the degeneracy in composition is reduced. In the observed planetary mass–mean density diagram, we identify a trend to more volatile-rich compositions with an increasing radius (R/R ⊕ ≲ 1.6 rocky; 1.6–3.0 ices, and/or H/He ≳3: H/He). The mass–density diagram contains important information about formation and evolution. Its characteristic broken V-shape reveals the transitions from solid planets to low-mass core-dominated planets with H/He and finally to gas-dominated giants. Evaporation causes the density and orbital distance to be anticorrelated for low-mass planets in contrast to giants, where closer-in planets are less dense, likely due to inflation. The temporal evolution of the statistical properties reported here will be of interest for the PLATO 2.0 mission, which will observe the temporal dimension.

  10. Effective mass of the four-flux composite fermion at {nu}=1/4

    Energy Technology Data Exchange (ETDEWEB)

    Pan, W. [Princeton University, Princeton, New Jersey 08544 (United States); National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Stormer, H. L. [Lucent Technologies, Bell Laboratories, Murray Hill, New Jersey 07974 (United States); Department of Physics and Department of Applied Physics, Columbia University, New York, New York 10027 (United States); Tsui, D. C. [Princeton University, Princeton, New Jersey 08544 (United States); Pfeiffer, L. N. [Lucent Technologies, Bell Laboratories, Murray Hill, New Jersey 07974 (United States); Baldwin, K. W. [Lucent Technologies, Bell Laboratories, Murray Hill, New Jersey 07974 (United States); West, K. W. [Lucent Technologies, Bell Laboratories, Murray Hill, New Jersey 07974 (United States)

    2000-02-15

    We have measured the effective mass (m{sup *}) of the four flux composite fermion at Landau-level filling factor {nu}=1/4 ({sup 4}CF), using the activation energy gaps at the fractional quantum Hall effect states {nu}=2/7, 3/11, and 4/15 and the temperature dependence of the Shubnikov-de Haas (SdH) oscillations around {nu}=1/4. We find that the energy gaps show a linear dependence on the effective magnetic field B{sub eff} ({identical_to}B-B{sub {nu}}{sub =1/4}), and from this linear dependence we obtain m{sup *}=1.0m{sub e} and a disorder broadening {gamma}{approx}1 K for a sample of density n=0.87x10{sup 11} cm{sup -2}. The m{sup *} deduced from the temperature dependence of the SdH effect shows large differences for {nu}>1/4 and {nu}<1/4. For {nu}>1/4, m{sup *}{approx}1.0m{sub e}. It scales as {radical}(B{sub {nu}}) with the mass derived from the data around {nu}=1/2 and shows an increase in m{sup *} as {nu}{yields}1/4, resembling the findings around {nu}=1/2. For {nu}<1/4, m{sup *} increases rapidly with increasing B{sub eff} and can be described by m{sup *}/m{sub e}=-3.3+5.7B{sub eff}. This anomalous dependence on B{sub eff} is precursory to the formation of the insulating phase at still lower filling. (c) 2000 The American Physical Society.

  11. Mean composite fire severity metrics computed with Google Earth Engine offer improved accuracy and expanded mapping potential

    Science.gov (United States)

    Parks, Sean; Holsinger, Lisa M.; Voss, Morgan; Loehman, Rachel A.; Robinson, Nathaniel P.

    2018-01-01

    Landsat-based fire severity datasets are an invaluable resource for monitoring and research purposes. These gridded fire severity datasets are generally produced with pre-and post-fire imagery to estimate the degree of fire-induced ecological change. Here, we introduce methods to produce three Landsat-based fire severity metrics using the Google Earth Engine (GEE) platform: the delta normalized burn ratio (dNBR), the relativized delta normalized burn ratio (RdNBR), and the relativized burn ratio (RBR). Our methods do not rely on time-consuming a priori scene selection and instead use a mean compositing approach in which all valid pixels (e.g. cloud-free) over a pre-specified date range (pre- and post-fire) are stacked and the mean value for each pixel over each stack is used to produce the resulting fire severity datasets. This approach demonstrates that fire severity datasets can be produced with relative ease and speed compared the standard approach in which one pre-fire and post-fire scene are judiciously identified and used to produce fire severity datasets. We also validate the GEE-derived fire severity metrics using field-based fire severity plots for 18 fires in the western US. These validations are compared to Landsat-based fire severity datasets produced using only one pre- and post-fire scene, which has been the standard approach in producing such datasets since their inception. Results indicate that the GEE-derived fire severity datasets show improved validation statistics compared to parallel versions in which only one pre-fire and post-fire scene are used. We provide code and a sample geospatial fire history layer to produce dNBR, RdNBR, and RBR for the 18 fires we evaluated. Although our approach requires that a geospatial fire history layer (i.e. fire perimeters) be produced independently and prior to applying our methods, we suggest our GEE methodology can reasonably be implemented on hundreds to thousands of fires, thereby increasing opportunities

  12. Body mass index and body composition among rescue firefighters personnel in Selangor, Malaysia

    Science.gov (United States)

    Rahimi, Nor Atiqah; Sedek, Razalee; Teh, Arnida Hani

    2016-11-01

    Obesity is a major public health problem in general population and there is no exception for firefighters. This disorder is definitely a burden for firefighters as they needed to be physically fit in order to work in dangerous situation and extinguishing fires. The purposes of this study were to determine physical characteristics and body composition among Malaysian Firefighters (MF) and to explore their association. This cross-sectional study involved 330 rescue firefighters aged between 20-50 years old from nine different districts in Selangor conducted between August and November 2015. Anthropometric measurements included height, weight and waist circumference (WC). Body composition was measured using bioelectrical impedance. The mean height, weight, body mass index (BMI), WC and body fat percentage were 169.4±5.3 cm, 74.5±12.2 kg, 25.9±3.82 kg/m2, 90.7±48.3 cm and 25.8±6.2 % respectively. The results also showed that 0.6% of them were underweight, 41.5% were normal, 44.8% were overweight and 13% were obese. The percentage of 34.8% firefighters with WC values of more than 90 cm means that they were at greater risk to have cardiovascular and diabetes disease. Body composition analysis showed that 75.5% of the subjects have high body fat level, 19.7% subjects were in healthy range but only 4.8% were considered as lean subjects. BMI was highly correlated with weight (r=0.917, p<0.01), WC (r=0.858, p<0.01) and body fat percentage (r=0.757, <0.01). Body fat percentage also showed to have a high correlation with BMI (r=0.757, p<0.01) and WC (r=0.693, p<0.01). Furthermore, overweight and obesity were found to be more prevalent among firefighters personnel of older age, married, less educated and have longer duration of services. It can be concluded that more than half of the firefighter personnel were either overweight or obese and 35% of them were at greater risk of having non-communicable diseases. This study provides useful information and serves as a source of

  13. Spatial patterns of bacterial abundance, activity and community composition in relation to water masses in the eastern Mediterranean Sea

    NARCIS (Netherlands)

    Yokokawa, Taichi; De Corte, Daniele; Sintes, Eva; Herndl, Gerhard J.

    2010-01-01

    To determine the variation of bacterial activity and community composition between and within specific water masses, samples were collected throughout the water column at 5 stations in the eastern Mediterranean Sea corresponding to the regions of the northern Aegean, mid-Aegean, western Cretan,

  14. PET/CT-guided percutaneous liver mass biopsies and ablations: Targeting accuracy of a single 20 s breath-hold PET acquisition

    International Nuclear Information System (INIS)

    Shyn, P.B.; Tatli, S.; Sahni, V.A.; Sadow, C.A.; Forgione, K.; Mauri, G.; Morrison, P.R.; Catalano, P.J.; Silverman, S.G.

    2014-01-01

    Aim: To determine whether a single 20 s breath-hold positron-emission tomography (PET) acquisition obtained during combined PET/computed tomography (CT)-guided percutaneous liver biopsy or ablation procedures has the potential to target 2-[ 18 F]-fluoro-2-deoxy-D-glucose (FDG)-avid liver masses as accurately as up to 180 s breath-hold PET acquisitions. Materials and methods: This retrospective study included 10 adult patients with 13 liver masses who underwent FDG PET/CT-guided percutaneous biopsies (n = 5) or ablations (n = 5). PET was acquired as nine sequential 20 s, monitored, same-level breath-hold frames and CT was acquired in one monitored breath-hold. Twenty, 40, 60, and 180 s PET datasets were reconstructed. Two blinded readers marked tumour centres on randomized PET and CT datasets. Three-dimensional spatial localization differences between PET datasets and either 180 s PET or CT were analysed using multiple regression analyses. Statistical tests were two-sided and p < 0.05 was considered significant. Results: Targeting differences between 20 s PET and 180 s PET ranged from 0.7–20.3 mm (mean 5.3 ± 4.4 mm; median 4.3) and were not statistically different from 40 or 60 s PET (p = 0.74 and 0.91, respectively). Targeting differences between 20 s PET and CT ranged from 1.4–36 mm (mean 9.6 ± 7.1 mm; median 8.2 mm) and were not statistically different from 40, 60, or 180 s PET (p = 0.84, 0.77, and 0.35, respectively). Conclusion: Single 20 s breath-hold PET acquisitions from PET/CT-guided percutaneous liver procedures have the potential to target FDG-avid liver masses with equivalent accuracy to 180 s summed, breath-hold PET acquisitions and may facilitate strategies that improve image registration and shorten procedure times

  15. Protein and Peptide Composition of Male Accessory Glands of Apis mellifera Drones Investigated by Mass Spectrometry

    Science.gov (United States)

    Gorshkov, Vladimir; Blenau, Wolfgang; Koeniger, Gudrun; Römpp, Andreas; Vilcinskas, Andreas; Spengler, Bernhard

    2015-01-01

    In honeybees, reproductive females usually mate early in their life with more than 10 males in free flight, often within 10 minutes, and then store male gametes for up to five years. Because of the extreme polyandry and mating in free flight special adaptations in males are most likely. We present here the results of an investigation of the protein content of four types of male reproductive glands from the Western honeybee (Apis mellifera) drone, namely seminal vesicles (secretion in ejaculate), as well as bulbus, cornua and mucus glands (secretions for the mating plug). Using high resolution and accuracy mass spectrometry and a combination of database searching and de novo sequencing techniques it was possible to identify 50 different proteins in total, inside all mentioned glands, except in the mucus gland. Most of the proteins are unique for a specific gland type, only one of them (H9KEY1/ATP synthase subunit O) was found in three glands, and 7 proteins were found in two types of glands. The identified proteins represent a wide variety of biological functions and can be assigned to several physiological classes, such as protection, energy generation, maintaining optimal conditions, associated mainly with vesicula seminalis; signaling, cuticle proteins, icarpin and apolipoproteins located mainly in the bulbus and cornua glands; and some other classes. Most of the discovered proteins were not found earlier during investigation of semen, seminal fluid and tissue of reproductive glands of the bee drone. Moreover, we provide here the origin of each protein. Thus, the presented data might shed light on the role of each reproductive gland. PMID:25955586

  16. Protein and Peptide Composition of Male Accessory Glands of Apis mellifera Drones Investigated by Mass Spectrometry.

    Science.gov (United States)

    Gorshkov, Vladimir; Blenau, Wolfgang; Koeniger, Gudrun; Römpp, Andreas; Vilcinskas, Andreas; Spengler, Bernhard

    2015-01-01

    In honeybees, reproductive females usually mate early in their life with more than 10 males in free flight, often within 10 minutes, and then store male gametes for up to five years. Because of the extreme polyandry and mating in free flight special adaptations in males are most likely. We present here the results of an investigation of the protein content of four types of male reproductive glands from the Western honeybee (Apis mellifera) drone, namely seminal vesicles (secretion in ejaculate), as well as bulbus, cornua and mucus glands (secretions for the mating plug). Using high resolution and accuracy mass spectrometry and a combination of database searching and de novo sequencing techniques it was possible to identify 50 different proteins in total, inside all mentioned glands, except in the mucus gland. Most of the proteins are unique for a specific gland type, only one of them (H9KEY1/ATP synthase subunit O) was found in three glands, and 7 proteins were found in two types of glands. The identified proteins represent a wide variety of biological functions and can be assigned to several physiological classes, such as protection, energy generation, maintaining optimal conditions, associated mainly with vesicula seminalis; signaling, cuticle proteins, icarpin and apolipoproteins located mainly in the bulbus and cornua glands; and some other classes. Most of the discovered proteins were not found earlier during investigation of semen, seminal fluid and tissue of reproductive glands of the bee drone. Moreover, we provide here the origin of each protein. Thus, the presented data might shed light on the role of each reproductive gland.

  17. Composite marginal quantile regression analysis for longitudinal adolescent body mass index data.

    Science.gov (United States)

    Yang, Chi-Chuan; Chen, Yi-Hau; Chang, Hsing-Yi

    2017-09-20

    Childhood and adolescenthood overweight or obesity, which may be quantified through the body mass index (BMI), is strongly associated with adult obesity and other health problems. Motivated by the child and adolescent behaviors in long-term evolution (CABLE) study, we are interested in individual, family, and school factors associated with marginal quantiles of longitudinal adolescent BMI values. We propose a new method for composite marginal quantile regression analysis for longitudinal outcome data, which performs marginal quantile regressions at multiple quantile levels simultaneously. The proposed method extends the quantile regression coefficient modeling method introduced by Frumento and Bottai (Biometrics 2016; 72:74-84) to longitudinal data accounting suitably for the correlation structure in longitudinal observations. A goodness-of-fit test for the proposed modeling is also developed. Simulation results show that the proposed method can be much more efficient than the analysis without taking correlation into account and the analysis performing separate quantile regressions at different quantile levels. The application to the longitudinal adolescent BMI data from the CABLE study demonstrates the practical utility of our proposal. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  18. Myoglobin plasma level related to muscle mass and fiber composition: a clinical marker of muscle wasting?

    Science.gov (United States)

    Weber, Marc-André; Kinscherf, Ralf; Krakowski-Roosen, Holger; Aulmann, Michael; Renk, Hanna; Künkele, Annette; Edler, Lutz; Kauczor, Hans-Ulrich; Hildebrandt, Wulf

    2007-08-01

    Progressive muscle wasting is a central feature of cancer-related cachexia and has been recognized as a determinant of poor prognosis and quality of life. However, until now, no easily assessable clinical marker exists that allows to predict or to track muscle wasting. The present study evaluated the potential of myoglobin (MG) plasma levels to indicate wasting of large locomotor muscles and, moreover, to reflect the loss of MG-rich fiber types, which are most relevant for daily performance. In 17 cancer-cachectic patients (weight loss 22%) and 27 age- and gender-matched healthy controls, we determined plasma levels of MG and creatine kinase (CK), maximal quadriceps muscle cross-sectional area (CSA) by magnetic resonance imaging, muscle morphology and fiber composition in biopsies from the vastus lateralis muscle, body cell mass (BCM) by impedance technique as well as maximal oxygen uptake (VO(2)max). In cachectic patients, plasma MG, muscle CSA, BCM, and VO(2)max were 30-35% below control levels. MG showed a significant positive correlation to total muscle CSA (r = 0.65, p max as an important functional readout. CK plasma levels appear to be less reliable because prolonged increases are observed in even subclinical myopathies or after exercise. Notably, cancer-related muscle wasting was not associated with increases in plasma MG or CK in this study.

  19. Comparison of Pu isotopic composition between gamma and mass spectrometry: Experience from IAEA-SAL

    International Nuclear Information System (INIS)

    Parus, J.L.; Raab, W.

    1998-01-01

    About 2000 Pu containing samples have been analysed during the last 8 years at SAL using gamma spectrometry (GS) in parallel with mass spectrometry (MS). Four different detectors have been used for the measurement of gamma-ray spectra and several versions of the MGA program have been used for spectra evaluation. The results of Pu isotopic composition obtained by both methods have neem systematically compared. Attempts to improve the agreement between GS and MS are described. This was done by adjustment of the emission probabilities for some gamma energies and the development of a new correlation equation for 242 Pu. These improvements have been applied for evaluation of two sets containing 320 and 404 samples, respectively analysed in 1991 and in 1992-93. The mean differences and their standard deviations between MS and GS were calculated, showing mean relative differences for 238-241 Pu isotopes in the range from 0.1 to 0.5% with standard deviations within ± 0.4 to ±1%. For 242 Pu these values are about 0.5% and ± 5%, respectively. (author)

  20. The size, mass, and composition of plastic debris in the western North Atlantic Ocean.

    Science.gov (United States)

    Morét-Ferguson, Skye; Law, Kara Lavender; Proskurowski, Giora; Murphy, Ellen K; Peacock, Emily E; Reddy, Christopher M

    2010-10-01

    This study reports the first inventory of physical properties of individual plastic debris in the North Atlantic. We analyzed 748 samples for size, mass, and material composition collected from surface net tows on 11 expeditions from Cape Cod, Massachusetts to the Caribbean Sea between 1991 and 2007. Particles were mostly fragments less than 10mm in size with nearly all lighter than 0.05 g. Material densities ranged from 0.808 to 1.24 g ml(-1), with about half between 0.97 and 1.04 g ml(-1), a range not typically found in virgin plastics. Elemental analysis suggests that samples in this density range are consistent with polypropylene and polyethylene whose densities have increased, likely due to biofouling. Pelagic densities varied considerably from that of beach plastic debris, suggesting that plastic particles are modified during their residence at sea. These analyses provide clues in understanding particle fate and potential debris sources, and address ecological implications of pelagic plastic debris. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Hierarchical Bayesian inference of the initial mass function in composite stellar populations

    Science.gov (United States)

    Dries, M.; Trager, S. C.; Koopmans, L. V. E.; Popping, G.; Somerville, R. S.

    2018-03-01

    The initial mass function (IMF) is a key ingredient in many studies of galaxy formation and evolution. Although the IMF is often assumed to be universal, there is continuing evidence that it is not universal. Spectroscopic studies that derive the IMF of the unresolved stellar populations of a galaxy often assume that this spectrum can be described by a single stellar population (SSP). To alleviate these limitations, in this paper we have developed a unique hierarchical Bayesian framework for modelling composite stellar populations (CSPs). Within this framework, we use a parametrized IMF prior to regulate a direct inference of the IMF. We use this new framework to determine the number of SSPs that is required to fit a set of realistic CSP mock spectra. The CSP mock spectra that we use are based on semi-analytic models and have an IMF that varies as a function of stellar velocity dispersion of the galaxy. Our results suggest that using a single SSP biases the determination of the IMF slope to a higher value than the true slope, although the trend with stellar velocity dispersion is overall recovered. If we include more SSPs in the fit, the Bayesian evidence increases significantly and the inferred IMF slopes of our mock spectra converge, within the errors, to their true values. Most of the bias is already removed by using two SSPs instead of one. We show that we can reconstruct the variable IMF of our mock spectra for signal-to-noise ratios exceeding ˜75.

  2. Aerosol composition in a stagnant air mass impacted by dense fogs: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, D.J.; Munger, J.W.; Waldman, J.M.; Hoffman, M.R.

    1984-01-01

    Over the last two winters, our research group has been investigating the chemical composition of fogwater and haze aerosol during wintertime stagnation episodes in the San Joaquin Valley of California. The valley is encompassed by mountain ranges. During the winter a strong subsidence inversion based below the natural boundaries of the valley restricts the ventilation of the air masses below the inversion. The residence time of an air parcel in the valley under these stagnation conditions is on the order of 8 days. Because the trapped air is very humid, stagnation episodes are associated with a persistent thick haze and frequent widespread nighttime fogs. During the winter 1982-1983 the authors sampled fog and haze at one site (Bakersfield); results from this preliminary study have been discussed in detail in a previous report. In the winter 1983-1984 the scale of the program was expanded in order to test hypotheses formulated as a result of first year data. The present paper first reports briefly on the 1982-1983 results and outlines the essential conclusions. They then describe the large-scale experiment conducted during the winter of 1983-1984, and discuss some preliminary fogwater data.

  3. Data on coffee composition and mass spectrometry analysis of mixtures of coffee related carbohydrates, phenolic compounds and peptides

    Directory of Open Access Journals (Sweden)

    Ana S.P. Moreira

    2017-08-01

    Full Text Available The data presented here are related to the research paper entitled “Transglycosylation reactions, a main mechanism of phenolics incorporation in coffee melanoidins: inhibition by Maillard reaction” (Moreira et al., 2017 [1]. Methanolysis was applied in coffee fractions to quantify glycosidically-linked phenolics in melanoidins. Moreover, model mixtures mimicking coffee beans composition were roasted and analyzed using mass spectrometry-based approaches to disclose the regulatory role of proteins in transglycosylation reactions extension. This article reports the detailed chemical composition of coffee beans and derived fractions. In addition, it provides gas chromatography–mass spectrometry (GC–MS chromatograms and respective GC–MS spectra of silylated methanolysis products obtained from phenolic compounds standards, as well as the detailed identification of all compounds observed by electrospray mass spectrometry (ESI-MS analysis of roasted model mixtures, paving the way for the identification of the same type of compounds in other samples.

  4. Mildronate (Meldonium) in professional sports - monitoring doping control urine samples using hydrophilic interaction liquid chromatography - high resolution/high accuracy mass spectrometry.

    Science.gov (United States)

    Görgens, Christian; Guddat, Sven; Dib, Josef; Geyer, Hans; Schänzer, Wilhelm; Thevis, Mario

    2015-01-01

    To date, substances such as Mildronate (Meldonium) are not on the radar of anti-doping laboratories as the compound is not explicitly classified as prohibited. However, the anti-ischemic drug Mildronate demonstrates an increase in endurance performance of athletes, improved rehabilitation after exercise, protection against stress, and enhanced activations of central nervous system (CNS) functions. In the present study, the existing evidence of Mildronate's usage in sport, which is arguably not (exclusively) based on medicinal reasons, is corroborated by unequivocal analytical data allowing the estimation of the prevalence and extent of misuse in professional sports. Such data are vital to support decision-making processes, particularly regarding the ban on drugs in sport. Due to the growing body of evidence (black market products and athlete statements) concerning its misuse in sport, adequate test methods for the reliable identification of Mildronate are required, especially since the substance has been added to the 2015 World Anti-Doping Agency (WADA) monitoring program. In the present study, two approaches were established using an in-house synthesized labelled internal standard (Mildronate-D3 ). One aimed at the implementation of the analyte into routine doping control screening methods to enable its monitoring at the lowest possible additional workload for the laboratory, and another that is appropriate for the peculiar specifics of the analyte, allowing the unequivocal confirmation of findings using hydrophilic interaction liquid chromatography-high resolution/high accuracy mass spectrometry (HILIC-HRMS). Here, according to applicable regulations in sports drug testing, a full qualitative validation was conducted. The assay demonstrated good specificity, robustness (rRT=0.3%), precision (intra-day: 7.0-8.4%; inter-day: 9.9-12.9%), excellent linearity (R>0.99) and an adequate lower limit of detection (<10 ng/mL). Copyright © 2015 John Wiley & Sons, Ltd.

  5. Mildronate (Meldonium) in professional sports – monitoring doping control urine samples using hydrophilic interaction liquid chromatography – high resolution/high accuracy mass spectrometry

    Science.gov (United States)

    Görgens, Christian; Dib, Josef; Geyer, Hans; Schänzer, Wilhelm; Thevis, Mario

    2015-01-01

    To date, substances such as Mildronate (Meldonium) are not on the radar of anti‐doping laboratories as the compound is not explicitly classified as prohibited. However, the anti‐ischemic drug Mildronate demonstrates an increase in endurance performance of athletes, improved rehabilitation after exercise, protection against stress, and enhanced activations of central nervous system (CNS) functions. In the present study, the existing evidence of Mildronate's usage in sport, which is arguably not (exclusively) based on medicinal reasons, is corroborated by unequivocal analytical data allowing the estimation of the prevalence and extent of misuse in professional sports. Such data are vital to support decision‐making processes, particularly regarding the ban on drugs in sport. Due to the growing body of evidence (black market products and athlete statements) concerning its misuse in sport, adequate test methods for the reliable identification of Mildronate are required, especially since the substance has been added to the 2015 World Anti‐Doping Agency (WADA) monitoring program. In the present study, two approaches were established using an in‐house synthesized labelled internal standard (Mildronate‐D3). One aimed at the implementation of the analyte into routine doping control screening methods to enable its monitoring at the lowest possible additional workload for the laboratory, and another that is appropriate for the peculiar specifics of the analyte, allowing the unequivocal confirmation of findings using hydrophilic interaction liquid chromatography‐high resolution/high accuracy mass spectrometry (HILIC‐HRMS). Here, according to applicable regulations in sports drug testing, a full qualitative validation was conducted. The assay demonstrated good specificity, robustness (rRT=0.3%), precision (intra‐day: 7.0–8.4%; inter‐day: 9.9–12.9%), excellent linearity (R>0.99) and an adequate lower limit of detection (<10 ng/mL). © 2015 The Authors

  6. Simplifying and expanding analytical capabilities for various classes of doping agents by means of direct urine injection high performance liquid chromatography high resolution/high accuracy mass spectrometry.

    Science.gov (United States)

    Görgens, Christian; Guddat, Sven; Thomas, Andreas; Wachsmuth, Philipp; Orlovius, Anne-Katrin; Sigmund, Gerd; Thevis, Mario; Schänzer, Wilhelm

    2016-11-30

    So far, in sports drug testing compounds of different classes are processed and measured using different screening procedures. The constantly increasing number of samples in doping analysis, as well as the large number of substances with doping related, pharmacological effects require the development of even more powerful assays than those already employed in sports drug testing, indispensably with reduced sample preparation procedures. The analysis of native urine samples after direct injection provides a promising analytical approach, which thereby possesses a broad applicability to many different compounds and their metabolites, without a time-consuming sample preparation. In this study, a novel multi-target approach based on liquid chromatography and high resolution/high accuracy mass spectrometry is presented to screen for more than 200 analytes of various classes of doping agents far below the required detection limits in sports drug testing. Here, classic groups of drugs as diuretics, stimulants, β 2 -agonists, narcotics and anabolic androgenic steroids as well as various newer target compounds like hypoxia-inducible factor (HIF) stabilizers, selective androgen receptor modulators (SARMs), selective estrogen receptor modulators (SERMs), plasma volume expanders and other doping related compounds, listed in the 2016 WADA prohibited list were implemented. As a main achievement, growth hormone releasing peptides could be implemented, which chemically belong to the group of small peptides (0.99), limit of detection (0.1-25ng/mL; 3'OH-stanozolol glucuronide: 50pg/mL; dextran/HES: 10μg/mL) and matrix effects. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Validation of an ultra-high-performance liquid chromatography-tandem mass spectrometry method to quantify illicit drug and pharmaceutical residues in wastewater using accuracy profile approach.

    Science.gov (United States)

    Hubert, Cécile; Roosen, Martin; Levi, Yves; Karolak, Sara

    2017-06-02

    The analysis of biomarkers in wastewater has become a common approach to assess community behavior. This method is an interesting way to estimate illicit drug consumption in a given population: by using a back calculation method, it is therefore possible to quantify the amount of a specific drug used in a community and to assess the consumption variation at different times and locations. Such a method needs reliable analytical data since the determination of a concentration in the ngL -1 range in a complex matrix is difficult and not easily reproducible. The best analytical method is liquid chromatography - mass spectrometry coupling after solid-phase extraction or on-line pre-concentration. Quality criteria are not specially defined for this kind of determination. In this context, it was decided to develop an UHPLC-MS/MS method to analyze 10 illicit drugs and pharmaceuticals in wastewater treatment plant influent or effluent using a pre-concentration on-line system. A validation process was then carried out using the accuracy profile concept as an innovative tool to estimate the probability of getting prospective results within specified acceptance limits. Influent and effluent samples were spiked with known amounts of the 10 compounds and analyzed three times a day for three days in order to estimate intra-day and inter-day variations. The matrix effect was estimated for each compound. The developed method can provide at least 80% of results within ±25% limits except for compounds that are degraded in influent. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Accuracy and Utility of Estimating Lean Body Mass and Nutritional Status in Patients with Chronic Kidney Disease on Long-Term Hemodialysis Using Anthropometric Skinfold Thickness Measurements.

    Science.gov (United States)

    Leong, Khai Gene; Chee, Jia Lian; Karahalios, Amalia; Skelley, Annabelle; Wong, Kim

    2018-01-01

    Malnutrition is common in patients on hemodialysis (prevalence of 30% to 50%) and is associated with higher mortality. Lean body mass (LBM) assessment is an accurate way of assessing nutritional status. The dual-energy X-ray absorptiometry (DEXA) scan is a reliable method in assessing body compositions and LBM; however, it is expensive and largely inaccessible. Anthropometric skinfold thickness measurement (ASFM) is useful in assessing LBM. It is cheaper and accessible, but underutilized clinically. The subjective global score (SGA) is a well-established method of assessing nutritional status. All three methods of assessing nutritional status were compared. In this pilot observational study, there was a significant correlation between LBM% estimated by DEXA and ASFM (mean difference -1.46% [95% CI -4.09 to 1.18]; LOA -14.0 to 11.1). Nutritional status by SGA could only detect those severely malnourished when using LBM% by ASFM as comparison. Our study demonstrated that ASFM is a useful method of assessing LBM and nutritional status, which can be easily utilized clinically. Copyright© by the American Nephrology Nurses Association.

  9. Characterization of aerosol chemical composition with aerosol mass spectrometry in Central Europe: an overview

    Directory of Open Access Journals (Sweden)

    V. A. Lanz

    2010-11-01

    Full Text Available Real-time measurements of non-refractory submicron aerosols (NR-PM1 were conducted within the greater Alpine region (Switzerland, Germany, Austria, France and Liechtenstein during several week-long field campaigns in 2002–2009. This region represents one of the most important economic and recreational spaces in Europe. A large variety of sites was covered including urban backgrounds, motorways, rural, remote, and high-alpine stations, and also mobile on-road measurements were performed. Inorganic and organic aerosol (OA fractions were determined by means of aerosol mass spectrometry (AMS. The data originating from 13 different field campaigns and the combined data have been utilized for providing an improved temporal and spatial data coverage.

    The average mass concentration of NR-PM1 for the different campaigns typically ranged between 10 and 30 μg m−3. Overall, the organic portion was most abundant, ranging from 36% to 81% of NR-PM1. Other main constituents comprised ammonium (5–15%, nitrate (8–36%, sulfate (3–26%, and chloride (0–5%. These latter anions were, on average, fully neutralized by ammonium. As a major result, time of the year (winter vs. summer and location of the site (Alpine valleys vs. Plateau could largely explain the variability in aerosol chemical composition for the different campaigns and were found to be better descriptors for aerosol composition than the type of site (urban, rural etc.. Thus, a reassessment of classifications of measurements sites might be considered in the future, possibly also for other regions of the world.

    The OA data was further analyzed using positive matrix factorization (PMF and the multi-linear engine ME (factor analysis separating the total OA into its underlying components, such as oxygenated (mostly secondary organic aerosol (OOA, hydrocarbon-like and freshly emitted organic aerosol (HOA, as well as OA from biomass

  10. Evaluation of lead isotope compositions of NIST NBS 981 measured by thermal ionization mass spectrometer and multiple-collector inductively coupled plasma mass spectrometer

    Directory of Open Access Journals (Sweden)

    Honglin Yuan

    2016-09-01

    Full Text Available Because Pb isotopes can be used for tracing, they are widely used in many disciplines. The detection and analysis of Pb isotopes of bulk samples are usually conducted using thermal ionization mass spectrometer (TIMS and multiple-collector inductively coupled plasma mass spectrometer (MC-ICP-MS, both of which need external reference materials with known isotopic compositions to correct for the mass discrimination effect produced during analysis. NIST NBS 981 is the most widely used reference material for Pb isotope analysis; however, the isotopic compositions reported by various analytical laboratories, especially those using TIMS, vary from each other. In this study, we statistically evaluated 229 reported TIMS analysis values collected by GeoReM in the last 30 years, 176 reported MC-ICP-MS analysis values, and 938 MC-ICP-MS analysis results from our laboratory in the last five years. After careful investigation, only 40 TIMS results were found to have double or triple spikes. The ratios of the overall weighted averages, 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb, obtained from 40 spiked TIMS reports and 1114 MC-ICP-MS results of NIST NBS 981 isotopes were 16.9406 ± 0.0003 (2s, 15.4957 ± 0.0002 (2s, and 36.7184 ± 0.0007 (2s, respectively.

  11. Evidence for a mixed mass composition at the ‘ankle’ in the cosmic-ray spectrum

    Directory of Open Access Journals (Sweden)

    A. Aab

    2016-11-01

    Full Text Available We report a first measurement for ultrahigh energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of air-showers registered simultaneously by the fluorescence and the surface detectors of the Pierre Auger Observatory. Such a correlation measurement is a unique feature of a hybrid air-shower observatory with sensitivity to both the electromagnetic and muonic components. It allows an accurate determination of the spread of primary masses in the cosmic-ray flux. Up till now, constraints on the spread of primary masses have been dominated by systematic uncertainties. The present correlation measurement is not affected by systematics in the measurement of the depth of shower maximum or the signal in the water Cherenkov stations. The analysis relies on general characteristics of air showers and is thus robust also with respect to uncertainties in hadronic event generators. The observed correlation in the energy range around the ‘ankle’ at lg⁡(E/eV=18.5–19.0 differs significantly from expectations for pure primary cosmic-ray compositions. A light composition made up of proton and helium only is equally inconsistent with observations. The data are explained well by a mixed composition including nuclei with mass A>4. Scenarios such as the proton dip model, with almost pure compositions, are thus disfavored as the sole explanation of the ultrahigh-energy cosmic-ray flux at Earth. Keywords: Pierre Auger Observatory, Cosmic rays, Mass composition, Ankle

  12. Elemental composition of air masses under different altitudes in Azores, central north Atlantic

    International Nuclear Information System (INIS)

    Vieira, B.J.; Wolterbeek, H.Th.

    2012-01-01

    Between 8th July 2002 and 18th June 2004, aerosol samples were collected in Azores. Their inorganic composition was obtained by neutron activation analysis in order to study the differences of aerosols in two atmospheric altitudes of the central north Atlantic: (1) PICO-NARE observatory (Lower Free Troposphere-LFT) at Pico mountain summit (38,470 deg N, 28,404 deg W, 2,225 m a.s.l.) in Pico Island, Azores, where air masses from the surrounding continents (Africa, Europe, Central and North America) pass through, carrying aerosols with anthropogenic (Sb, Br, Mo, U, Se and Tb) and/or natural emissions (Fe, Co, La, Na, Sm, Cr, Zn, Hf, K and Th); (2) TERCEIRA-NARE station (Marine Boundary Layer) at Serreta (38,69 deg N, 27,36 deg W, 50 m a.s.l.), in Terceira Island, Azores, where natural aerosols (I, Cl, Na, Br and other soil related elements) are predominant. However, a combined interpretation of the data points out to a co-existence of the anthropogenic elements Sb and Mo, eventually with similar origins as the ones passing Pico Mountain summit. Very high concentrations and enrichment factors for Sb, Mo and Br in LFT, higher than the ones found in other areas, confirm atmospheric long-range transport mainly from the west boundary of north Atlantic; this may indicate eventual accumulation and persistence of those elements in the area due to the presence of Azores high pressures or the Hadley cells effect. A significant correlation between Fe and Yb and the enrichment of rare earth elements (La, Sm, Tb and Yb) and Th in LFT aerosols, both reflect a mineral dust intrusions from north Africa (Sahara and Sahel region). (author)

  13. Molecular composition of organic aerosols in central Amazonia: an ultra-high-resolution mass spectrometry study

    OpenAIRE

    Kourtchev, I; Godoi, RHM; Connors, S; Levine, JG; Archibald, AT; Godoi, AFL; Paralovo, SL; Barbosa, CGG; Souza, RAF; Manzi, AO; Seco, R; Sjostedt, S; Park, J-H; Guenther, A; Kim, S

    2016-01-01

    The Amazon Basin plays key role in atmospheric chemistry, biodiversity and climate change. In this study we applied nanoelectrospray (nanoESI) ultra-high-resolution mass spectrometry (UHRMS) for the analysis of the organic fraction of PM$_{2.5}$ aerosol samples collected during dry and wet seasons at a site in central Amazonia receiving background air masses, biomass burning and urban pollution. Comprehensive mass spectral data evaluation methods (e.g. Kendrick mass defect, Van Krevelen diagr...

  14. Measurement of the High-Mass Drell-Yan Cross Section and Limits on Quark-Electron Compositeness Scales

    International Nuclear Information System (INIS)

    Grinstein, S.; Mostafa, M.; Piegaia, R.; Alves, G.A.; Carvalho, W.; Maciel, A.K.; Motta, H. da; Oliveira, E.; Santoro, A.; Lima, J.G.; Oguri, V.; Gomez, B.; Hoeneisen, B.; Mooney, P.; Negret, J.P.; Ducros, Y.; Beri, S.B.; Bhatnagar, V.; Kohli, J.M.; Singh, J.B.; Shivpuri, R.K.; Acharya, B.S.; Banerjee, S.; Dugad, S.R.; Gupta, A.; Krishnaswamy, M.R.; Mondal, N.K.; Narasimham, V.S.; Parua, N.; Shankar, H.C.; Park, Y.M.; Choi, S.; Kim, S.K.; Castilla-Valdez, H.; Gonzalez Solis, J.L.; Hernandez-Montoya, R.; Magana-Mendoza, L.; Sanchez-Hernandez, A.; Pawlik, B.; Gavrilov, V.; Gershtein, Y.; Kuleshov, S.; Belyaev, A.; Dudko, L.V.; Ermolov, P.; Karmanov, D.; Leflat, A.; Manankov, V.; Merkin, M.; Shabalina, E.; Abramov, V.; Babintsev, V.V.; Bezzubov, V.A.; Bojko, N.I.; Burtovoi, V.S.; Chekulaev, S.V.; Denisov, S.P.; Dyshkant, A.; Eroshin, O.V.; Evdokimov, V.N.; Galyaev, A.N.; Goncharov, P.I.; Gurzhiev, S.N.; Kostritskiy, A.V.; Kozelov, A.V.; Kozlovsky, E.A.; Mayorov, A.A.; Babukhadia, L.; Davis, K.; Fein, D.; Forden, G.E.; Guida, J.A.; Johns, K.; Nang, F.; Narayanan, A.; Rutherfoord, J.; Shupe, M.; Aihara, H.; Barberis, E.; Clark, A.R.

    1999-01-01

    We present a measurement of the Drell-Yan cross section at high dielectron invariant mass using 120 pb -1 of data collected in p bar p collisions at √ (s) =1.8 TeV by the D0 Collaboration during 1992 - 1996. No deviation from standard model expectations is observed. We use the data to set limits on the quark-electron compositeness scale. The 95% confidence level lower limits on the compositeness scale vary between 3.3 and 6.1thinspthinspTeV depending on the assumed form of the effective contact interaction. copyright 1999 The American Physical Society

  15. Search for quark compositeness, axigluons, and heavy particles using the dijet invariant mass spectrum observed in p bar p collisions

    International Nuclear Information System (INIS)

    Abe, F.; Albrow, M.; Akimoto, H.; Amidei, D.; Anway-Wiese, C.; Apollinari, G.; Areti, H.; Auchincloss, P.; Azfar, F.; Azzi, P.; Bacchetta, N.; Badgett, W.; Bailey, M.W.; Bao, J.; de Barbaro, P.; Barbaro-Galtieri, A.; Barnes, V.E.; Barnett, B.A.; Bauer, G.; Baumann, T.; Bedeschi, F.; Behrends, S.; Belforte, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Benlloch, J.; Benton, D.; Beretvas, A.; Berge, J.P.; Bertolucci, S.; Bhatti, A.; Biery, K.; Binkley, M.; Bird, F.; Bisello, D.; Blair, R.E.; Blocker, C.; Bodek, A.; Bolognesi, V.; Bortoletto, D.; Boswell, C.; Boulos, T.; Brandenburg, G.; Bromberg, C.; Buckley-Geer, E.; Budd, H.S.; Burkett, K.; Busetto, G.; Byon-Wagner, A.; Byrum, K.L.; Campagnari, C.; Campbell, M.; Caner, A.; Carithers, W.; Carlsmith, D.; Castro, A.; Cen, Y.; Cervelli, F.; Chapman, J.; Chiarelli, G.; Chikamatsu, T.; Cihangir, S.; Clark, A.G.; Cobal, M.; Contreras, M.; Conway, J.; Cooper, J.; Cordelli, M.; Coupal, D.P.; Crane, D.; Cunningham, J.D.; Daniels, T.; Deninno, M.; DeJongh, F.; Dell'Agnello, S.; Dell'Orso, M.; Demortier, L.; Denby, B.; Derwent, P.F.; Devlin, T.; Dickson, M.; Done, J.P.; Drucker, R.B.; Dunn, A.; Einsweiler, K.; Elias, J.E.; Engels, E. Jr.; Ely, R.; Eno, S.; Errede, D.; Errede, S.; Etchegoyen, A.; Fan, Q.; Farhat, B.; Fiori, I.; Flaugher, B.; Foster, G.W.; Franklin, M.; Frautschi, M.; Freeman, J.; Freidman, J.; Frisch, H.; Fry, A.; Fuess, T.A.; Fukui, Y.; Funaki, S.; Garfinkel, A.F.; Geer, S.; Gerdes, D.W.; Giannetti, P.; Giokaris, N.; Giormini, P.; Gladney, L.; Glenzinski, D.; Gold, M.; Gonzalez, J.; Goshaw, A.T.; Goulianos, K.; Grassmann, H.; Grewal, A.; Grieco, G.; Groer, L.; Grosso-Pilcher, C.; Haber, C.; Hahn, S.R.; Hamilton, R.; Handler, R.; Hans, R.M.; Hara, K.; Harral, B.; Harris, R.M.; Hauger, S.A.; Hauser, J.; Hawk, C.; Heinrich, J.; Hennessy, D.; Hipple, R.; Hollebeek, R.; Hoelscher, A.; Hong, S.; Houk, G.; Hu, P.; Huston, J.; Huffman, B.T.; Hughes, R.; Hurst, P.; Huth, J.; Hylen, J.; Incagli, M.

    1993-01-01

    The dijet invariant mass distribution has been measured in the region between 140 and 1000 GeV/c 2 , in 1.8 TeV p bar p collisions. Data collected with the Collider Detector at Fermilab show agreement with QCD calculations. A limit on quark compositeness of Λ c >1.3 TeV is obtained. Axigluons with masses between 240 and 640 GeV/c 2 are excluded at 95% C.L. if we assume ten open decay channels. Model-independent limits on the production of heavy particles decaying into two jets are also presented

  16. The Influence Of Mass Fraction Of Dressed Coal On Ignition Conditions Of Composite Liquid Fuel Droplet

    Directory of Open Access Journals (Sweden)

    Shlegel Nikita E.

    2015-01-01

    Full Text Available The laws of condition modification of inert heat and ignition in an oxidant flow of composite liquid fuel droplet were studied by the developed experimental setup. Investigations were for composite liquid fuel composition based on the waste of bituminous and nonbaking coal processing, appropriate carbon dust, water, used motor oil. The characteristics of boundary layer inertia heat of composite liquid fuel droplet, thermal decomposition of coal organic part, the yield of volatiles and evaporation of liquid combustion component, ignition of the gas mixture and coke residue were defined.

  17. Changes in fat-free mass in obese subjects after weight loss : a comparison of body composition measures

    NARCIS (Netherlands)

    van der Kooy, K; Leenen, R; Deurenberg, P.; Seidell, J C; Westerterp, K R; Hautvast, J.G.A.J.

    Estimates of body composition by densitometry were made in 84 apparently healthy subjects (42 men, 42 women) with a mean age of 40 +/- 6 years (mean +/- s.d.), before and after weight loss. The initial body mass index (BMI) was 30.7 +/- 2.3 kg/m2 and the achieved weight loss on a 4.2 MJ/day energy

  18. Evidence for a mixed mass composition at the ´ankle´ in the cosmic-ray spectrum

    Czech Academy of Sciences Publication Activity Database

    Aab, A.; Abreu, P.; Aglietta, M.; Blažek, Jiří; Boháčová, Martina; Chudoba, Jiří; Ebr, Jan; Mandát, Dušan; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Trávníček, Petr; Vícha, Jakub

    2016-01-01

    Roč. 762, Nov (2016), s. 288-295 ISSN 0370-2693 R&D Projects: GA MŠk LM2015038; GA MŠk LG15014; GA ČR(CZ) GA14-17501S Institutional support: RVO:68378271 Keywords : ankle * cosmic rays * mass composition * Pierre Auger Observatory Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.807, year: 2016

  19. Detection of Amyloid Beta (Aβ) Oligomeric Composition Using Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (MALDI MS)

    Science.gov (United States)

    Wang, Jasmine S.-H.; Whitehead, Shawn N.; Yeung, Ken K.-C.

    2018-02-01

    The use of MALDI MS as a fast and direct method to detect the Aβ oligomers of different masses is examined in this paper. Experimental results suggest that Aβ oligomers are ionized and detected as singly charged ions, and thus, the resulting mass spectrum directly reports the oligomer size distribution. Validation experiments were performed to verify the MS data against artifacts. Mass spectra collected from modified Aβ peptides with different propensities for aggregation were compared. Generally, the relative intensities of multimers were higher from samples where oligomerization was expected to be more favorable, and vice versa. MALDI MS was also able to detect the differences in oligomeric composition before and after the incubation/oligomerization step. Such differences in sample composition were also independently confirmed with an in vitro Aβ toxicity study on primary rat cortical neurons. An additional validation was accomplished through removal of oligomers from the sample using molecular weight cutoff filters; the resulting MS data correctly reflected the removal at the expected cutoff points. The results collectively validated the ability of MALDI MS to assess the monomeric/multimeric composition of Aβ samples. [Figure not available: see fulltext.

  20. Elemental Composition Analysis to Investigate NOx Effects on Secondary Organic Aerosol from α-Pinene Using Ultrahigh Resolution Mass Spectrometry

    Science.gov (United States)

    Lim, H. J.; Park, J. H.; Babar, Z.

    2015-12-01

    Secondary organic aerosol (SOA) accounts for 20-70% of atmospheric fine aerosol. NOx plays crucial roles in SOA formation and consequently affects the composition and yield of SOA. SOA component speciation is incomplete due to its complex composition of polar oxygenated and multifunctional species. In this study, ultrahigh resolution mass spectrometry (UHR MS) was applied to improve the understanding of NOx effects on biogenic SOA formation by identifying the elemental composition of SOA. Additional research aim was to investigate oligomer components that are considered as a driving force for SOA formation and growth. In this study α-pinene SOA from photochemical reaction was examined. SOA formation was performed in the absence and presence of NOx at dry condition (grant funded by the Korea government (MEST) (No. 2011-01350000).

  1. Introduction to Body Composition Assessment Using the Deuterium Dilution Technique with Analysis of Urine Samples by Isotope Ratio Mass Spectrometry

    International Nuclear Information System (INIS)

    2010-01-01

    The IAEA has fostered the more widespread use of a stable isotope technique to assess body composition in different population groups to address priority areas in public health nutrition in Member States. It has done this by supporting national and regional nutrition projects through its technical cooperation programme and coordinated research projects over many years. This publication was developed by an international group of experts to provide practical hands-on guidance in the use of this technique in settings where analysis of stable isotope ratios in biological samples is to be made by isotope ratio mass spectrometry. The publication is targeted at new users of this technique, for example nutritionists, analytical chemists and other professionals. More detailed information on the theoretical background and the practical applications of state of the art methodologies to monitor changes in body composition can be found in IAEA Human Health Series No. 3, Assessment of Body Composition and Total Energy Expenditure in Humans by Stable Isotope Techniques

  2. A continuous flow isotope ratio mass spectrometry method for high precision determination of dissolved gas ratios and isotopic composition

    DEFF Research Database (Denmark)

    Charoenpong, C. N.; Bristow, L. A.; Altabet, M. A.

    2014-01-01

    ratio mass spectrometer (IRMS). A continuous flow of He carrier gas completely degasses the sample, and passes through the preparation and purification system before entering the IRMS for analysis. The use of this continuous He carrier permits short analysis times (less than 8 min per sample......) as compared with current high-precision methods. In addition to reference gases, calibration is achieved using air-equilibrated water standards of known temperature and salinity. Assessment of reference gas injections, air equilibrated standards, as well as samples collected in the field shows the accuracy...

  3. Theoretical light curve for the recurrent nova RS Ophiuchi - Determination of the white dwarf mass, composition, and distance

    International Nuclear Information System (INIS)

    Kato, M.

    1991-01-01

    Sequences of steady mass-loss solutions are constructed for the envelopes on a white dwarf with mass 1.33, 1.35, 1.36, 1.37, and 1.377 solar mass as models of the decay phase of novae. The envelopes are assumed to have a uniform chemical composition with X = 0.73, 0.6, 0.52, 0.44, 0.33, and 0.11 for hydrogen and Z = 0.02 for heavy elements by weight. An excellent agreement with the observed light curves of UV and optical is obtained in the models with a white dwarf mass of 1.36 solar mass with hydrogen content X = 0.52, and 1.37 solar mass with X = 0.6. The distance of RS Oph is obtained to be 1.6 kpc from the comparison between the theoretical and observed light curves. The success of this wind model is a strong indication from the theoretical point of view that RS Oph is a thermonuclear runaway event. 31 refs

  4. Quantifying the effect of medium composition on the diffusive mass transfer of hydrophobic organic chemicals through unstirred boundary layers

    DEFF Research Database (Denmark)

    Mayer, Philipp; Karlson, U.; Christensen, P.S.

    2005-01-01

    Unstirred boundary layers (UBLs) often act as a bottleneck for the diffusive transport of hydrophobic organic compounds (HOCs) in the environment. Therefore, a microscale technique was developed for quantifying mass transfer through a 100-μm thin UBL, with the medium composition of the UBL...... as the controllable factor. The model compound fluoranthene had to (1) partition from a contaminated silicone disk (source) into the medium, (2) then diffuse through 100 μm of medium (UBL), and finally (3) partition into a clean silicone layer (sink). The diffusive mass transfer from source to sink was monitored over...... of magnitude. These results demonstrate that medium constituents, which normally are believed to bind hydrophobic organic chemicals, actually can enhance the diffusive mass transfer of HOCs in the vicinity of a diffusion source (e.g., contaminated soil particles). The technique can be used to evaluate...

  5. Composites

    International Nuclear Information System (INIS)

    Kasen, M.B.

    1983-01-01

    This chapter discusses the roles of composite laminates and aggregates in cryogenic technology. Filamentary-reinforced composites are emphasized because they are the most widely used composite materials. Topics considered include composite systems and terminology, design and fabrication, composite failure, high-pressure reinforced plastic laminates, low-pressure reinforced plastics, reinforced metals, selectively reinforced structures, the effect of cryogenic temperatures, woven-fabric and random-mat composites, uniaxial fiber-reinforced composites, composite joints in cryogenic structures, joining techniques at room temperature, radiation effects, testing laminates at cryogenic temperatures, static and cyclic tensile testing, static and cyclic compression testing, interlaminar shear testing, secondary property tests, and concrete aggregates. It is suggested that cryogenic composite technology would benefit from the development of a fracture mechanics model for predicting the fitness-for-purpose of polymer-matrix composite structures

  6. Improved Diagnostic Accuracy in Characterization of Adnexal Masses by Detection of Choline Peak Using 1H MR Spectroscopy in Comparison to Internal Reference at 3 Tesla.

    Science.gov (United States)

    Malek, Mahrooz; Pourashraf, Maryam; Gilani, Mitra Modares; Gity, Masoumeh

    2015-01-01

    The aim of this study was to assess the role of the presence of a choline peak in 3 Tesla 1H magnetic resonance spectroscopy (MRS) for differentiating benign from malignant adnexal masses. A total of 46 adnexal masses (23 malignant and 23 benign) underwent 1H MRS study prior to surgery to assess the presence of choline peak. A choline peak was detected in 16 malignant masses (69.5%) and was absent in the other 7 (30.5%). A choline peak was only detected in 6 (26%) of the benign adnexal masses. The presence of an MRS choline peak had a sensitivity of 69.5%, a specificity of 74%, a positive predictive value (PPV) of 72.7%, and a negative predictive value (NPV) of 71% for diagnosing malignant adnexal masses. A significant difference between the frequency of mean choline peaks in benign and malignant adnexal masses was observed (P valuepeak is seen in malignant adnexal masses more frequently than the benign masses, and may be helpful for diagnosing malignant adnexal masses.

  7. Mass spectrometric measurements of the freestream composition in the T4 free-piston shock-tunnel

    Science.gov (United States)

    Boyce, R. R.; Takahashi, M.; Stalker, R. J.

    2005-12-01

    The freestream composition is an important parameter in ground-based aerodynamic testing, and direct measurement of it is very important. This paper reports extensive composition measurements in the freestream of the T4 free-piston shock-tunnel, employing a recently improved time-of-flight mass spectrometer. A wide range of nozzle reservoir conditions were used. The results show good agreement between measured and theoretical values for nitric oxide over the entire enthalpy range reported (2.5 13 MJ/kg). This provides confidence that the chemistry model is correctly predicting sudden freezing of NO in the nozzle expansion. On the other hand, no monatomic species have been measured other than those produced by dissociative ionisation within the mass spectrometer, even at flow conditions where significant freestream dissociation is expected. Furthermore, excess diatomic oxygen is detected at high enthalpies. These observations are consistent with the possibility that oxygen recombination is not correctly predicted in the nozzle expansion, with sudden freezing occurring significantly later than predicted. However, the observations are also consistent with possible catalytic recombination in the skimmer system. The possibility for producing an empirical correlation between the freestream composition and the reservoir entropy has also been observed.

  8. Ion Composition of Comet 19P/Borrelly as Measured by the PEPE Ion Mass Spectrometer on DS1

    Science.gov (United States)

    Nordholt, J. E.; Reisenfeld, D. B.; Wiens, R. C.; Gary, P.

    2002-12-01

    Cometary compositions are of great interest because they hold important clues to the formation of the outer solar system, and to the sources of volatiles in the solar system, including the terrestrial planets. In order to understand the primordial compositions of cometary nuclei, it is important to also understand their evolution, as many of the comets most accessible to spacecraft are highly evolved. It is also important to understand the ion and neutral chemistry that occurs in the coma surrounding the nucleus if the coma ion composition is to be used to determine the original composition of the nucleus. Deep Space One (DS1) was only the second spacecraft, after Giotto, to use an ion mass-resolving instrument to explore cometary coma compositions in-situ, which it did during the flyby of Comet Borrelly on September 22, 2001. Borrelly is significantly more evolved than Halley. In addition, the encounter occurred at a significantly greater distance from the sun (1.36 AU vs 0.9 AU for Giotto at Halley). The Plasma Experiment for Planetary Exploration (PEPE) on board DS1 was capable of resolving electron and ion energy, angle of incidence, and ion mass composition. The PEPE ion data from the seven minutes surrounding closest approach (2171 km) have been extensively analyzed. The instrument response was modeled using SIMION and TRIM codes for all of the major species through 20 AMU plus CO (at its operating voltage PEPE was very insensitive to heavier molecules). Chi-squared minimization analysis is being carried out to determine the best fit and the uncertainties. Preliminary results for the predominant heavy ions are OH+ at (72 +/- 9)% of the total water-group ion density, H2O+ at (25 +/- 7)%, CH3+ at (5 +/- 3)%, and O+ at (4 +/- 5)%. Uncertainties are quoted at the 90% confidence level. Comparison with reported Halley compositions from Giotto shows that Borrelly clearly has a lower H3O+ abundance (< 9%), consistent with a more evolved comet. The presence of

  9. Size resolved mass concentration and elemental composition of atmospheric aerosols over the Eastern Mediterranean area

    Directory of Open Access Journals (Sweden)

    J. Smolík

    2003-01-01

    Full Text Available A Berner low pressure impactor was used to collect size-segregated aerosol samples at Finokalia, located on the north-eastern coast of Crete, Greece during July 2000 and January 2001. Several samples were also collected during the summer campaign aboard the research vessel "AEGAIEO" in the Aegean Sea. Gravimetric analysis and inversion techniques yielded daily PM1 and PM10 mass concentrations. The samples were also analysed by PIXE giving the elemental size distributions of Al, Si, K, Ca, Ti, Mn, Fe, Sr, S, Cl, Ni, V, Cu, Cr, Zn, and Pb. The crustal elements and sea-salt had a unimodal supermicron size distribution. Sulphur was found predominantly in submicron fractions. K, V, and Ni exhibited a bimodal distribution with a submicron mode produced by forest fires and oil combustion. The anthropogenic elements had broad and not well-defined distributions. The time series for PM1 and PM10 mass and elemental concentrations showed both daily and seasonal variation. Higher mass concentrations were observed during two incursions of Saharan dust, whilst higher concentrations of S, Cu, Zn, and Pb were encountered in samples collected in air masses arriving from northern Greece or the western coast of Turkey. Elevated concentrations of chlorine were found in samples with air masses either originating above the Atlantic Ocean and arriving at Finokalia via western Europe or recirculating over the western coast of the Black Sea.

  10. [Correlation of molecular weight and nanofiltration mass transfer coefficient of phenolic acid composition from Salvia miltiorrhiza].

    Science.gov (United States)

    Li, Cun-Yu; Wu, Xin; Gu, Jia-Mei; Li, Hong-Yang; Peng, Guo-Ping

    2018-04-01

    Based on the molecular sieving and solution-diffusion effect in nanofiltration separation, the correlation between initial concentration and mass transfer coefficient of three typical phenolic acids from Salvia miltiorrhiza was fitted to analyze the relationship among mass transfer coefficient, molecular weight and concentration. The experiment showed a linear relationship between operation pressure and membrane flux. Meanwhile, the membrane flux was gradually decayed with the increase of solute concentration. On the basis of the molecular sieving and solution-diffusion effect, the mass transfer coefficient and initial concentration of three phenolic acids showed a power function relationship, and the regression coefficients were all greater than 0.9. The mass transfer coefficient and molecular weight of three phenolic acids were negatively correlated with each other, and the order from high to low is protocatechualdehyde >rosmarinic acid> salvianolic acid B. The separation mechanism of nanofiltration for phenolic acids was further clarified through the analysis of the correlation of molecular weight and nanofiltration mass transfer coefficient. The findings provide references for nanofiltration separation, especially for traditional Chinese medicine with phenolic acids. Copyright© by the Chinese Pharmaceutical Association.

  11. High Mass-Loading of Sulfur-Based Cathode Composites and Polysulfides Stabilization for Rechargeable Lithium/Sulfur Batteries

    International Nuclear Information System (INIS)

    Hara, Toru; Konarov, Aishuak; Mentbayeva, Almagul; Kurmanbayeva, Indira; Bakenov, Zhumabay

    2015-01-01

    Although sulfur has a high theoretical gravimetric capacity, 1672 mAh/g, its insulating nature requires a large amount of conducting additives: this tends to result in a low mass-loading of active material (sulfur), and thereby, a lower capacity than expected. Therefore, an optimal choice of conducting agents and of the method for sulfur/conducting-agent integration is critically important. In this paper, we report that the areal capacity of 4.9 mAh/cm 2 was achieved at sulfur mass loading of 4.1 mg/cm 2 by casting sulfur/polyacrylonitrile/ketjenblack (S/PAN/KB) cathode composite into carbon fiber paper. This is the highest value among published/reported ones even though it does not contain expensive nanosized carbon materials such as carbon nanotubes, graphene, or graphene derivatives, and competitive enough with the conventional LiCoO 2 -based cathodes (e.g., LiCoO 2 , <20 mg/cm 2 corresponding to <2.8 mAh/cm 2 ). Furthermore, the combination of sulfur/PAN-based composite and PAN-based carbon fiber paper enabled the sulfur-based composite to be used even in carbonate-based electrolyte solution that many lithium/sulfur battery researchers avoid the use of it because of severer irreversible active material loss than in electrolyte solutions without carbonate-based solutions, and even at the highest mass-loading ever reported (the more sulfur is loaded, the more decomposed sulfides deposit at an anode surface).

  12. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2011-01-01

    Strategies are open compositions to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them in full...

  13. Composition

    DEFF Research Database (Denmark)

    2014-01-01

    Memory Pieces are open compositions to be realised solo by an improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them...

  14. Air mass origins influencing TTL chemical composition over West Africa during 2006 summer monsoon

    Directory of Open Access Journals (Sweden)

    K. S. Law

    2010-11-01

    Full Text Available Trace gas and aerosol data collected in the tropical tropopause layer (TTL between 12–18.5 km by the M55 Geophysica aircraft as part of the SCOUT-AMMA campaign over West Africa during the summer monsoon in August 2006 have been analysed in terms of their air mass origins. Analysis of domain filling back trajectories arriving over West Africa, and in the specific region of the flights, showed that the M55 flights were generally representative of air masses arriving over West Africa during the first 2 weeks of August, 2006. Air originating from the mid-latitude lower stratosphere was under-sampled (in the mid-upper TTL whilst air masses uplifted from central Africa (into the lower TTL were over-sampled in the latter part of the campaign. Signatures of recent (previous 10 days origins were superimposed on the large-scale westward flow over West Africa. In the lower TTL, air masses were impacted by recent local deep convection over Africa at the level of main convective outflow (350 K, 200 hPa and on certain days up to 370 K (100 hPa. Estimates of the fraction of air masses influenced by local convection vary from 10 to 50% depending on the method applied and from day to day during the campaign. The analysis shows that flights on 7, 8 and 11 August were more influenced by local convection than on 4 and 13 August allowing separation of trace gas and aerosol measurements into "convective" and "non-convective" flights. Strong signatures, particularly in species with short lifetimes (relative to CO2 like CO, NO and fine-mode aerosols were seen during flights most influenced by convection up to 350–365 K. Observed profiles were also constantly perturbed by uplift (as high as 39% of air masses from the mid to lower troposphere over Asia, India, and oceanic regions resulting in import of clean oceanic (e.g. O3-poor or polluted air masses from Asia (high O3, CO, CO2 into West Africa. Thus, recent uplift of CO

  15. Size Resolved Mass Concentration and Elemental Composition of Atmospheric Aerosols over the Eastern Mediterranean Area

    Czech Academy of Sciences Publication Activity Database

    Smolík, Jiří; Ždímal, Vladimír; Schwarz, Jaroslav; Lazaridis, M.; Havránek, Vladimír; Eleftheriadis, K.; Mihalopoulos, N.; Bryant, C.; Colbeck, I.

    2003-01-01

    Roč. 3, - (2003), s. 2207-2216 ISSN 1680-7324 Grant - others:ENVK2(XE) 1999/00052 Institutional research plan: CEZ:AV0Z1048901; CEZ:AV0Z4072921 Keywords : atmospheric particles * elemental composition * PM1 Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.317, year: 2003

  16. Size Resolved Mass Concentration and Elemental Composition of Atmospheric Aerosols over the Eastern Mediterranean Area

    Czech Academy of Sciences Publication Activity Database

    Smolík, Jiří; Ždímal, Vladimír; Schwarz, Jaroslav; Lazaridis, M.; Havránek, Vladimír; Eleftheriadis, K.; Mihalopoulos, N.; Bryant, C.; Colbeck, I.

    2003-01-01

    Roč. 3, - (2003), s. 2547-2573 ISSN 1680-7367 Grant - others:ENVK2(XE) 1999/00052 Institutional research plan: CEZ:AV0Z1048901; CEZ:AV0Z4072921 Keywords : atmospheric particles * PM1 * elemental composition Subject RIV: CF - Physical ; Theoretical Chemistry

  17. Statistical Optimization of Medium Compositions for High Cell Mass and Exopolysaccharide Production by Lactobacillus plantarum ATCC 8014

    Directory of Open Access Journals (Sweden)

    Nor Zalina Othman

    2018-03-01

    Full Text Available Background and Objective: Lactobacillus plantarum ATCC 8014 is known as a good producer of water soluble exopolysaccharide. Therefore, the aim of this study is to optimize the medium composition concurrently for high cell mass and exopolysaccharide production by Lactobacillus plantarum ATCC 8014. Since both are useful for food and pharmaceutical application and where most studies typically focus on one outcome only, the optimization process was carried out by using molasses as cheaper carbon source.Material and Methods: The main medium component which is known significantly give high effect on the cell mass and EPS production was selected as variables and statistically optimized based on Box-Behnken design in shake flask levels. The optimal medium for cell mass and exopolysaccharide production was composed of (in g l -1: molasses, 40; yeast extract, 16.8; phosphate, 2.72; sodium acetate, 3.98. The model was found to be significant and subsequently validated through the growth kinetics studies in un-optimized and optimized medium in the shake flask cultivation.Results and Conclusion: The maximum cell mass and exopolysaccharide in the new optimized medium was 4.40 g l-1 and 4.37 g l-1 respectively after 44 h of the cultivation. As a result, cell mass and exopolysaccharide production increased up to 4.5 and 16.5 times respectively, and the maximal exopolysaccharide yield of 1.19 per gram of cells was obtained when molasses was used as the carbon source. In conclusion, molasses has the potential to be a cheap carbon source for the cultivation of Lactobacillus plantarum ATCC 8014 concurrently for high cell mass and exopolysaccharide production.Conflict of interest: The authors declare no conflict of interest.

  18. Relationship between Body Mass Composition, Bone Mineral Density, Skin Fibrosis and 25(OH Vitamin D Serum Levels in Systemic Sclerosis.

    Directory of Open Access Journals (Sweden)

    Addolorata Corrado

    Full Text Available A reduced bone mineral density (BMD is observed in several rheumatic autoimmune diseases, including Systemic Sclerosis (SSc; nevertheless, data concerning the possible determinants of bone loss in this disease are not fully investigated. The aim of this study is to evaluate the relationship between BMD, body mass composition, skin sclerosis and serum Vitamin D levels in two subsets of SSc patients. 64 post-menopausal SSc patients, classified as limited cutaneous (lcSSc or diffuse cutaneous (dcSSc SSc, were studied. As control, 35 healthy post-menopausal women were recruited. Clinical parameters were evaluated, including the extent of skin involvement. BMD at lumbar spine, hip, femoral neck and body mass composition were determined by dual-energy X-ray absorptiometry. Serum calcium, phosphorus, alkaline phosphatase, urine pyridinium cross-links, intact parathyroid hormone and 25-hydroxyvitamin D (25OHD were measured. BMD at spine, femoral neck and total hip was significantly lower in SSc patients compared to controls. In dcSSc subset, BMD at spine, femoral neck and total hip was significantly lower compared to lcSSc. No differences in both fat and lean mass were found in the three study groups even if patients with dcSSc showed a slightly lower total body mass compared to healthy controls. Total mineral content was significantly reduced in dSSc compared to both healthy subjects and lcSSc group. Hypovitaminosis D was observed both in healthy post-menopausal women and in SSc patients, but 25OHD levels were significantly lower in dcSSc compared to lcSSc and inversely correlated with the extent of skin thickness. These results support the hypothesis that the extent of skin involvement in SSc patients could be an important factor in determining low circulating levels of 25OHD, which in turn could play a significant role in the reduction of BMD and total mineral content.

  19. Non-constant relative atomic masses due to varying isotopic abundance of polynuclidic elements and their effect on the accuracy of analytical results

    International Nuclear Information System (INIS)

    Gerstenberger, H.

    1981-01-01

    Alterations of actual relative atomic masses occur in natural samples by natural isotope ratio shifts of polynuclidic elements. Therefore, using nuclear properties for gaining a measuring signal, isotopic shifts of certain elements may lead to significant measuring errors

  20. Validation of the determination of the B isotopic composition in Roman glasses with laser ablation multi-collector inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    Devulder, Veerle; Gerdes, Axel; Vanhaecke, Frank; Degryse, Patrick

    2015-01-01

    The applicability of laser ablation multi-collector inductively coupled plasma-mass spectrometry (LA-MC-ICP-MS) for the determination of the B isotopic composition in Roman glasses was investigated. The δ 11 B values thus obtained provide information on the natron flux used during the glass-making process. The glass samples used for this purpose were previously characterized using pneumatic nebulization (PN) MC-ICP-MS. Unfortunately, this method is time-consuming and labor-intensive and consumes some 100 mg of sample, which is a rather high amount for ancient materials. Therefore, the use of the less invasive and faster LA-MC-ICP-MS approach was explored. In this work, the results for 29 Roman glasses and 4 home-made glasses obtained using both techniques were compared to assess the suitability of LA-MC-ICP-MS in this context. The results are in excellent agreement within experimental uncertainty. No difference in overall mass discrimination was observed between the Roman glasses, NIST SRM 610 reference glass and B6 obsidian. The expanded uncertainty of the LA-MC-ICP-MS approach was estimated to be < 2‰, which is similar to that obtained upon sample digestion and PN-MC-ICP-MS measurement. - Highlights: • First use of LA-MC-ICP-MS for B isotopic analysis of ancient glass • Careful validation of LA-MC-ICP-MS approach • Similar precision & accuracy via solution MC-ICP-MS after isolation of B • Enhancement of sample throughput & reduction of sample consumption • Improved conditions for archeometric research on (pre-)Roman glass

  1. Validation of the determination of the B isotopic composition in Roman glasses with laser ablation multi-collector inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Devulder, Veerle [Department of Analytical Chemistry, Ghent University, Krijgslaan 281-S12, 9000 Ghent (Belgium); Department of Earth and Environmental Sciences, Katholieke Universiteit Leuven, Celestijnenlaan 200 E-box 2408, 3001 Leuven (Belgium); Gerdes, Axel [Institute of Geoscience, Goethe Universität, Altenhoeferallee 1, 60438 Frankfurt am Main (Germany); Vanhaecke, Frank, E-mail: Frank.Vanhaecke@UGent.be [Department of Analytical Chemistry, Ghent University, Krijgslaan 281-S12, 9000 Ghent (Belgium); Degryse, Patrick [Department of Earth and Environmental Sciences, Katholieke Universiteit Leuven, Celestijnenlaan 200 E-box 2408, 3001 Leuven (Belgium)

    2015-03-01

    The applicability of laser ablation multi-collector inductively coupled plasma-mass spectrometry (LA-MC-ICP-MS) for the determination of the B isotopic composition in Roman glasses was investigated. The δ{sup 11}B values thus obtained provide information on the natron flux used during the glass-making process. The glass samples used for this purpose were previously characterized using pneumatic nebulization (PN) MC-ICP-MS. Unfortunately, this method is time-consuming and labor-intensive and consumes some 100 mg of sample, which is a rather high amount for ancient materials. Therefore, the use of the less invasive and faster LA-MC-ICP-MS approach was explored. In this work, the results for 29 Roman glasses and 4 home-made glasses obtained using both techniques were compared to assess the suitability of LA-MC-ICP-MS in this context. The results are in excellent agreement within experimental uncertainty. No difference in overall mass discrimination was observed between the Roman glasses, NIST SRM 610 reference glass and B6 obsidian. The expanded uncertainty of the LA-MC-ICP-MS approach was estimated to be < 2‰, which is similar to that obtained upon sample digestion and PN-MC-ICP-MS measurement. - Highlights: • First use of LA-MC-ICP-MS for B isotopic analysis of ancient glass • Careful validation of LA-MC-ICP-MS approach • Similar precision & accuracy via solution MC-ICP-MS after isolation of B • Enhancement of sample throughput & reduction of sample consumption • Improved conditions for archeometric research on (pre-)Roman glass.

  2. Compositional changes of human hair melanin resulting from bleach treatment investigated by nanoscale secondary ion mass spectrometry.

    Science.gov (United States)

    Kojima, Toru; Yamada, Hiromi; Isobe, Mitsuru; Yamamoto, Toshihiko; Takeuchi, Miyuki; Aoki, Dan; Matsushita, Yasuyuki; Fukushima, Kazuhiko

    2014-11-01

    It is important to understand the influence of bleach treatment on human hair because it is one of the most important chemical treatments in hair cosmetic processes. A comparison of the elemental composition of melanin between virgin hair and bleached hair would provide important information about the structural changes of melanin. To investigate the elemental composition of melanin granules in virgin black hair and bleached hair, these hair cross-sections are analyzed by using a nanoscale secondary ion mass spectrometry (NanoSIMS). The virgin black hair and bleached hair samples were embedded in resin and smooth hair cross-sections were obtained using an ultramicrotome. NanoSIMS measurements were performed using a Cs(+) primary ion beam to detect negative secondary ions. More intensive (16) O(-) ions were detected from the melanin granules of bleached hair than from those of virgin black hair in NanoSIMS (16) O(-) ion image. In addition, it was indicated that (16) O(-) ion intensity and (16) O(-) /(12) C(14) N(-) ion intensity ratio of melanin granules in bleached hair were higher than those in virgin black hair. Nanoscale secondary ion mass spectrometry analysis of the cross-sections of virgin black hair and bleached hair indicated that the oxygen content in melanin granules was increased by bleach treatment. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Direct Analysis of Samples of Various Origin and Composition Using Specific Types of Mass Spectrometry.

    Science.gov (United States)

    Byliński, Hubert; Gębicki, Jacek; Dymerski, Tomasz; Namieśnik, Jacek

    2017-07-04

    One of the major sources of error that occur during chemical analysis utilizing the more conventional and established analytical techniques is the possibility of losing part of the analytes during the sample preparation stage. Unfortunately, this sample preparation stage is required to improve analytical sensitivity and precision. Direct techniques have helped to shorten or even bypass the sample preparation stage; and in this review, we comment of some of the new direct techniques that are mass-spectrometry based. The study presents information about the measurement techniques using mass spectrometry, which allow direct sample analysis, without sample preparation or limiting some pre-concentration steps. MALDI - MS, PTR - MS, SIFT - MS, DESI - MS techniques are discussed. These solutions have numerous applications in different fields of human activity due to their interesting properties. The advantages and disadvantages of these techniques are presented. The trends in development of direct analysis using the aforementioned techniques are also presented.

  4. Dynamic displacements of the RHIC dipole cold mass with injection molded composite posts during quench conditions

    International Nuclear Information System (INIS)

    Sondericker, J.; Wolf, L.J.

    1991-02-01

    The new design of the RHIC dipole magnets incorporate helium containment bellows having a convolution diameter of only 7.63 inches. The present bellows are 12.80 inches in diameter. The smaller bellows present a substantially reduced pressure area which can be expected to reduce proportionately the end force on the cold mass during a quench. But, the objection was raised that the smaller bellows would present greater obstruction to the helium flow during a quench thereby producing higher pressure differentials. This analysis was undertaken to address these assertions by predicting the dynamic displacements of the cold mass using the latest test data on the stiffness of the IMC posts, pressure-time histories acquired from the recent full cell tests of RHIC magnets, and the dimensions of the new expansion joints. The analysis treated the cold mass as an elastic body having a saggittal curvature. The technique of normal mode expansion of a lumped-parameter system was used to obtain the results and conclusions reported herein

  5. Titan's organic aerosols: Molecular composition and structure of laboratory analogues inferred from pyrolysis gas chromatography mass spectrometry analysis

    Science.gov (United States)

    Morisson, Marietta; Szopa, Cyril; Carrasco, Nathalie; Buch, Arnaud; Gautier, Thomas

    2016-10-01

    Analogues of Titan's aerosols are of primary interest in the understanding of Titan's atmospheric chemistry and climate, and in the development of in situ instrumentation for future space missions. Numerous studies have been carried out to characterize laboratory analogues of Titan aerosols (tholins), but their molecular composition and structure are still poorly known. If pyrolysis gas chromatography mass spectrometry (pyr-GCMS) has been used for years to give clues about their chemical composition, highly disparate results were obtained with this technique. They can be attributed to the variety of analytical conditions used for pyr-GCMS analyses, and/or to differences in the nature of the analogues analyzed, that were produced with different laboratory set-ups under various operating conditions. In order to have a better description of Titan's tholin's molecular composition by pyr-GCMS, we carried out a systematic study with two major objectives: (i) exploring the pyr-GCMS analytical parameters to find the optimal ones for the detection of a wide range of chemical products allowing a characterization of the tholins composition as comprehensive as possible, and (ii) highlighting the role of the CH4 ratio in the gaseous reactive medium on the tholin's molecular structure. We used a radio-frequency plasma discharge to synthetize tholins with different concentrations of CH4 diluted in N2. The samples were pyrolyzed at temperatures covering the 200-700°C range. The extracted gases were then analyzed by GCMS for their molecular identification. The optimal pyrolysis temperature for characterizing the molecular composition of our tholins by GCMS analysis is found to be 600°C. This temperature choice results from the best compromise between the number of compounds released, the quality of the signal and the appearance of pyrolysis artifacts. About a hundred molecules are identified as pyrolysates. A common major chromatographic pattern appears clearly for all the

  6. Aerosol composition and properties variation at the ground and over the column under different air masses advection in South Italy.

    Science.gov (United States)

    Pavese, G; Lettino, A; Calvello, M; Esposito, F; Fiore, S

    2016-04-01

    Aerosol composition and properties variation under the advection of different air masses were investigated, as case studies, by contemporary measurements over the atmospheric column and at the ground in a semi-rural site in South Italy. The absence of local strong sources in this area allowed to characterize background aerosol and to compare particle mixing effects under various atmospheric circulation conditions. Aerosol optical depth (AOD) and Ǻngström parameters from radiometric measurements allowed the detection and identification of polluted, dust, and volcanic atmospheric conditions. AODs were the input for a suitable model to evaluate the columnar aerosol composition, according to six main atmospheric components (water-soluble, soot, sea salt accumulation, sea salt coarse, mineral dus,t and biological). Scanning electron microscope (SEM) analysis of particulate sampled with a 13-stage impactor at the ground showed not only fingerprints typical of the different air masses but also the effects of transport and aging on atmospheric particles, suggesting processes that changed their chemical and optical properties. Background columnar aerosol was characterized by 72% of water-soluble and soot, in agreement with ground-based findings that highlighted 60% of contribution from anthropogenic carbonate particles and soot. In general, a good agreement between ground-based and columnar results was observed. Under the advection of trans-boundary air masses, water-soluble and soot were always present in columnar aerosol, whereas, in variable percentages, sea salt and mineral particles characterized both dust and volcanic conditions. At the ground, sulfates characterized the amorphous matrix produced in finer stages by the evaporation of solutions of organic and inorganic aerosols. Sulfates were also one of the key players involved in heterogeneous chemical reactions, producing complex secondary aerosol, as such clay-sulfate internally mixed particle externally mixed

  7. Dietary protein content alters energy expenditure and composition of the mass gain in grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    Felicetti, Laura A; Robbins, Charles T; Shipley, Lisa A

    2003-01-01

    Many fruits contain high levels of available energy but very low levels of protein and other nutrients. The discrepancy between available energy and protein creates a physiological paradox for many animals consuming high-fruit diets, as they will be protein deficient if they eat to meet their minimum energy requirement. We fed young grizzly bears both high-energy pelleted and fruit diets containing from 1.6% to 15.4% protein to examine the role of diet-induced thermogenesis and fat synthesis in dealing with high-energy-low-protein diets. Digestible energy intake at mass maintenance increased 2.1 times, and composition of the gain changed from primarily lean mass to entirely fat when the protein content of the diet decreased from 15.4% to 1.6%. Daily fat gain was up to three times higher in bears fed low-protein diets ad lib., compared with bears consuming the higher-protein diet and gaining mass at the same rate. Thus, bears eating fruit can either consume other foods to increase dietary protein content and reduce energy expenditure, intake, and potentially foraging time or overeat high-fruit diets and use diet-induced thermogenesis and fat synthesis to deal with their skewed energy-to-protein ratio. These are not discrete options but a continuum that creates numerous solutions for balancing energy expenditure, intake, foraging time, fat accumulation, and ultimately fitness, depending on food availability, foraging efficiency, bear size, and body condition.

  8. Molecular species composition of plant cardiolipin determined by liquid chromatography mass spectrometry

    Science.gov (United States)

    Zhou, Yonghong; Peisker, Helga

    2016-01-01

    Cardiolipin (CL), an anionic phospholipid of the inner mitochondrial membrane, provides essential functions for stabilizing respiratory complexes and is involved in mitochondrial morphogenesis and programmed cell death in animals. The role of CL and its metabolism in plants are less well understood. The measurement of CL in plants, including its molecular species composition, is hampered by the fact that CL is of extremely low abundance, and that plants contain large amounts of interfering compounds including galactolipids, neutral lipids, and pigments. We used solid phase extraction by anion exchange chromatography to purify CL from crude plant lipid extracts. LC/MS was used to determine the content and molecular species composition of CL. Thus, up to 23 different molecular species of CL were detected in different plant species, including Arabidopsis, mung bean, spinach, barley, and tobacco. Similar to animals, plant CL is dominated by highly unsaturated species, mostly containing linoleic and linolenic acid. During phosphate deprivation or exposure to an extended dark period, the amount of CL decreased in Arabidopsis, accompanied with an increased degree in unsaturation. The mechanism of CL remodeling during stress, and the function of highly unsaturated CL molecular species, remains to be defined. PMID:27179363

  9. Development of the composition of chocolate mass that resistant to bloom

    Directory of Open Access Journals (Sweden)

    M. E. Tkeshelashvili

    2017-01-01

    Full Text Available Chocolate or used as a coating on the surface of the sweets chocolate mass when exposed to a temperature drop and/or a drop in the humidity of the environment, change color, lose gloss and acquire an unwanted grayish-white surface. The loss of the appearance of chocolate – the effect of bloom is the reason for the return of products from the trading network causing highly tangible the economic damage to the producers. In this connection, experimental researches devoted to the problem of preventing bloom and developing consist of chocolate masses preclusion to bloom appear to be an urgent task. The purpose of the research is develop consist of chocolate and covering chocolate resistant to bloom. The work is performed at the Scientific research institute of «Applied research of innovative technologies and food quality» of Plekhanov Russian University of Economics. For an investigation, samples of chocolate and covering chocolate based on cocoa butter were made in the formulation of which an additive including milk fat/isomalt/polydextrose. The control samples were dark chocolate and covering chocolate prepared according to a unified formula. For the formation of blooming, the samples were exposed to temperature fluctuations and relative humidity. The measurement of the color of chocolate is implementation by an instrumental method based on the analysis of the optical characteristics of the product. The coefficients of reflection spectra of samples of chocolate were converted into color coordinates of space CIEL ? a ? b* 1976. The emergence of a bloom of chocolate by changing the parameter lightness L ? (CIEL ? a ? b* was diagnosed. The effect of introducing an additive, including milk fat/isomalt/polydextrose on fat and sugar bloom, was determined in the formulation of chocolate masses. Based on research the consist of the chocolate mass has been developed which practically does not change the taste of the finished chocolate products

  10. Establishing the accuracy of asteroseismic mass and radius estimates of giant stars - I. Three eclipsing systems at [Fe/H] ˜ -0.3 and the need for a large high-precision sample

    Science.gov (United States)

    Brogaard, K.; Hansen, C. J.; Miglio, A.; Slumstrup, D.; Frandsen, S.; Jessen-Hansen, J.; Lund, M. N.; Bossini, D.; Thygesen, A.; Davies, G. R.; Chaplin, W. J.; Arentoft, T.; Bruntt, H.; Grundahl, F.; Handberg, R.

    2018-05-01

    We aim to establish and improve the accuracy level of asteroseismic estimates of mass, radius, and age of giant stars. This can be achieved by measuring independent, accurate, and precise masses, radii, effective temperatures and metallicities of long period eclipsing binary stars with a red giant component that displays solar-like oscillations. We measured precise properties of the three eclipsing binary systems KIC 7037405, KIC 9540226, and KIC 9970396 and estimated their ages be 5.3 ± 0.5, 3.1 ± 0.6, and 4.8 ± 0.5 Gyr. The measurements of the giant stars were compared to corresponding measurements of mass, radius, and age using asteroseismic scaling relations and grid modelling. We found that asteroseismic scaling relations without corrections to Δν systematically overestimate the masses of the three red giants by 11.7 per cent, 13.7 per cent, and 18.9 per cent, respectively. However, by applying theoretical correction factors fΔν according to Rodrigues et al. (2017), we reached general agreement between dynamical and asteroseismic mass estimates, and no indications of systematic differences at the precision level of the asteroseismic measurements. The larger sample investigated by Gaulme et al. (2016) showed a much more complicated situation, where some stars show agreement between the dynamical and corrected asteroseismic measures while others suggest significant overestimates of the asteroseismic measures. We found no simple explanation for this, but indications of several potential problems, some theoretical, others observational. Therefore, an extension of the present precision study to a larger sample of eclipsing systems is crucial for establishing and improving the accuracy of asteroseismology of giant stars.

  11. Laboratory Studies of Planetary Hazes: composition of cool exoplanet atmospheric aerosols with very high resolution mass spectrometry

    Science.gov (United States)

    Moran, Sarah E.; Horst, Sarah; He, Chao; Flandinet, Laurene; Moses, Julianne I.; Orthous-Daunay, Francois-Regis; Vuitton, Veronique; Wolters, Cedric; Lewis, Nikole

    2017-10-01

    We present first results of the composition of laboratory-produced exoplanet haze analogues. With the Planetary HAZE Research (PHAZER) Laboratory, we simulated nine exoplanet atmospheres of varying initial gas phase compositions representing increasing metallicities (100x, 1000x, and 10000x solar) and exposed them to three different temperature regimes (600, 400, and 300 K) with two different “instellation” sources (a plasma source and a UV lamp). The PHAZER exoplanet experiments simulate a temperature and atmospheric composition phase space relevant to the expected planetary yield of the Transiting Exoplanet Survey Satellite (TESS) mission as well as recently discovered potentially habitable zone exoplanets in the TRAPPIST-1, LHS-1140, and Proxima Centauri systems. Upon exposure to the energy sources, all of these experiments produced aerosol particles, which were collected in a dry nitrogen glove box and then analyzed with an LTQ Orbitrap XL™ Hybrid Ion Trap-Orbitrap Mass Spectrometer utilizing m/z ranging from 50 to 1000. The collected aerosol samples were found to contain complex organics. Constraining the composition of these aerosols allows us to better understand the photochemical and dynamical processes ongoing in exoplanet atmospheres. Moreover, these data can inform our telescope observations of exoplanets, which is of critical importance as we enter a new era of exoplanet atmosphere observation science with the upcoming launch of the James Webb Space Telescope. The molecular makeup of these haze particles provides key information for understanding exoplanet atmospheric spectra, and constraining the structure and behavior of clouds, hazes, and other aerosols is at the forefront of exoplanet atmosphere science.

  12. Aged-Related Changes in Body Composition and Association between Body Composition with Bone Mass Density by Body Mass Index in Chinese Han Men over 50-year-old.

    Directory of Open Access Journals (Sweden)

    Ying Jiang

    Full Text Available Aging, body composition, and body mass index (BMI are important factors in bone mineral density (BMD. Although several studies have investigated the various parameters and factors that differentially influence BMD, the results have been inconsistent. Thus, the primary goal of the present study was to further characterize the relationships of aging, body composition parameters, and BMI with BMD in Chinese Han males older than 50 years.The present study was a retrospective analysis of the body composition, BMI, and BMD of 358 Chinese male outpatients between 50 and 89 years of age that were recruited from our hospital between 2009 and 2011. Qualified subjects were stratified according to age and BMI as follows: 50-59 (n = 35, 60-69 (n = 123, 70-79 (n = 93, and 80-89 (n = 107 years of age and low weight (BMI: < 20 kg/m2; n = 21, medium weight (20 ≤ BMI < 24 kg/m2; n = 118, overweight (24 ≤ BMI < 28 kg/m2; n = 178, and obese (BMI ≥ 28 kg/m2; n = 41. Dual-energy X-ray absorptiometry (DEXA was used to assess bone mineral content (BMC, lean mass (LM, fat mass (FM, fat-free mass (FFM, lumbar spine (L1-L4 BMD, femoral neck BMD, and total hip BMD. Additionally, the FM index (FMI; FM/height2, LM index (LMI; LM/height2, FFM index (FFMI; [BMC+LM]/height2, percentage of BMC (%BMC; BMC/[BMC+FM+LM] × 100%, percentage of FM (%FM; FM/[BMC+FM+LM] × 100%, and percentage of LM (%LM; LM/(BMC+FM+LM × 100% were calculated. Osteopenia or osteoporosis was identified using the criteria and T-score of the World Health Organization.Although there were no significant differences in BMI among the age groups, there was a significant decline in height and weight according to age (p < 0.0001 and p = 0.0002, respectively. The LMI and FFMI also declined with age (both p < 0.0001 whereas the FMI exhibited a significant increase that peaked in the 80-89-years group (p = 0.0145. Although the absolute values of BMC and LM declined with age (p = 0.0031 and p < 0

  13. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2014-01-01

    Cue Rondo is an open composition to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound/video files will in some cases only provide a few minutes' sample, or the visuals will not appear at all....... Please DOWNLOAD them to see/hear them in full length! This work is licensed under a Creative Commons "by-nc" License. You may for non-commercial purposes use and distribute it, performance instructions as well as specially designated recordings, as long as the author is mentioned. Please see http...

  14. Inferring the Composition of Super-Jupiter Mass Companions of Pulsars with Radio Line Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Alak; Loeb, Abraham, E-mail: akr@tifr.res.in, E-mail: aloeb@cfa.harvard.edu [Institute of Theory and Computation, Center for Astrophysics, Harvard University 60 Garden Street, Cambridge, MA 02138 (United States)

    2017-02-10

    We propose using radio line spectroscopy to detect molecular absorption lines (such as OH at 1.6–1.7 GHz) before and after the total eclipse of black widow and other short orbital period binary pulsars with low-mass companions. The companion in such a binary may be ablated away by energetic particles and high-energy radiation produced by the pulsar wind. The observations will probe the eclipsing wind being ablated by the pulsar and constrain the nature of the companion and its surroundings. Maser emission from the interstellar medium stimulated by a pulsar beam might also be detected from the intrabinary medium. The short temporal resolution allowed by the millisecond pulsars can probe this medium with the high angular resolution of the pulsar beam.

  15. Heat and mass transfer in a liquid pool with wall ablation and composition effects

    International Nuclear Information System (INIS)

    Pham, Q.T.

    2013-01-01

    This work deals with the thermal-hydraulics of a melt pool coupled with the physical chemistry for the purpose of describing the behaviour of mixtures of materials (non-eutectic). Evolution of transient temperature in a liquid melt pool heated by volumetric power dissipation has been described with solidification on the cooled wall. The model has been developed and is validated for the experimental results given by LIVE experiment, performed at Karlsruhe Institute of Technology (KIT) in Germany. Under the conditions of these tests, it is shown that the interface temperature follows the liquidus temperature (corresponding to the composition of the liquid bath) during the whole transient. Assumption of interface temperature as liquidus temperature allows recalculating the evolution of the maximum melt temperature as well as the local crust thickness. Furthermore, we propose a model for describing the interaction between a non-eutectic liquid melt pool (subjected to volumetric power dissipation) and an ablated wall whose melting point is below the liquidus temperature of the melt. The model predictions are compared with results of ARTEMIS 2D tests. A new formulation of the interface temperature between the liquid melt and the solid wall (below liquidus temperature) has been proposed. (author) [fr

  16. EDXRS study of aerosol composition variations in air masses crossing the North Sea

    International Nuclear Information System (INIS)

    Injuk, J.; Malderen, H. van; Grieken, R. van; Swietlicki, E.; Knox, J.M.; Schofield, R.

    1993-01-01

    X-ray emission techniques for bulk and individual particle analysis (EDXRF, EPXMA, micro-PIXE) were combined and applied in atmospheric research on the North Sea area as part of a field-study on air-sea exchange processes of particulate matter. The atmospheric loading for a number of elements was determined by EDXRF, yielding bulk concentrations for Mg, Al, Si, S, Cl, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Br and Sr. From these EDXRF data, deposition rates were derived and, based on a classical multivariate statistical approach, different aerosol sources were identified. Complementary to this work, EPXMA combined with automated image analysis was applied to individual size-segregated aerosol particles to determine their inorganic composition, physical size and shape. Also, the first results of micro-PIXE analyses on individual North Sea aerosol particles, particularly their large-size fraction, are discussed and compared with the corresponding EPXMA results. In summary, such a joint approach with the use of different x-ray emission techniques contributed to the resolution of the mixed structure of the lower North Sea troposphere and to the determination of the atmospheric supply of material to the North Sea environment. (author)

  17. The Accuracy of Praziquantel Dose Poles for Mass Treatment of Schistosomiasis in School Girls in KwaZulu-Natal, South Africa

    DEFF Research Database (Denmark)

    Baan, Marije; Galappaththi-Arachchige, Hashini Nilushika; Gagai, Silindile

    2016-01-01

    and the recently developed Modified Dose Pole for adults with two additional intervals and correction for body mass index (BMI). Methodology In randomly selected primary and secondary schools of schistosomiasis-endemic areas, height and weight of female pupils were measured. The WHO Tablet Pole and Modified Dose....... Conclusions This study shows that the WHO Tablet Pole will be inaccurate in estimating the dose of praziquantel in South African girls due to high prevalence of overweight/obesity. Under-dosing of individuals who appear overweight/obese could be largely prevented by adding an extra praziquantel tablet...

  18. Thermal ionisation mass spectrometry (TIMS): what, how and why?

    International Nuclear Information System (INIS)

    Aggarwal, S.K.

    2002-01-01

    Thermal ionisation mass spectrometry (TIMS) is one of the oldest mass spectrometric techniques, which has been used for determining the isotopic composition and concentration of different elements using isotope dilution. In spite of the introduction of many other inorganic mass spectrometric techniques like spark source mass spectrometry (SSMS), glow discharge mass spectrometry (GDMS), inductively coupled plasma-mass spectrometry (ICP-MS), secondary ion mass spectrometry (SIMS), the TIMS technique plays the role of a definitive analytical methodology and still occupies a unique position in terms of its capabilities with respect to precision and accuracy as well as sensitivity

  19. Mass spectrometry imaging: Towards mapping the elemental and molecular composition of the rhizosphere

    Energy Technology Data Exchange (ETDEWEB)

    Veličković, Dušan; Anderton, Christopher R.

    2017-06-01

    This short review will discuss and provide perspective into the utilization of mass spectrometry imaging (MSI) in studying the rhizosphere. It also serves to compliment the multi-omic focused review by White et al. in this journal issue, as MSI is capable of elucidating chemical distributions within samples of interest in an in situ fashions, and thus can provide spatial context to MS omics data in complementary experimental endeavors. The majority of reported MSI-based studies of plant-microbe interactions have focused on the phyllosphere and ‘associated rhizosphere’ (e.g., material that is not removed during harvesting), as sample preparation for these in situ analyses tends to be a limiting factor. These studies have provided valuable insight into the spatial arrangement of proteins, peptides, lipids, and other metabolites within these systems. We intend for this short review to be a primer about the history of MSI and its role in plant-microbe analysis. Along the way we reference many comprehensive reviews for the interested reader. Lastly, we offer a perspective on the future of MSI and its use in understanding the molecular transformations beyond what we coined as the ‘associated rhizosphere’ to the rest of rhizosphere zone and into the bulk soil.

  20. Site-Specific Hydrogen Isotope Composition of Propane: Mass spectrometric methods, equilibrium temperature dependence, and kinetics of exchange

    Science.gov (United States)

    Xie, H.; Ponton, C.; Kitchen, N.; Lloyd, M. K.; Lawson, M.; Formolo, M. J.; Eiler, J. M.

    2016-12-01

    Intramolecular isotope ordering can constrain temperatures of synthesis, mechanisms of formation, and/or source substrates of organic compounds. Here we explore site-specific hydrogen isotope variations of propane. Statistical thermodynamic models predict that at equilibrium methylene hydrogen (-CH2-) in propane will be 10's of per mil higher in D/H ratio than methyl hydrogen (-CH3) at geologically relevant temperatures, and that this difference is highly temperature dependent ( 0.5-1 ‰/°C). Chemical-kinetic controls on site-specific D/H in propane could constrain the mechanisms, conditions and extents of propane synthesis or destruction. We have developed a method for measuring the difference in D/H ratio between methylene and methyl hydrogen in propane by gas source mass spectrometry. The data were measured using the Thermo Fisher Double Focusing Sector high resolution mass spectrometer (DFS), and involve comparison of the D/H ratios of molecular ion (C3H8+) and the ethyl fragmental ion (C2H5+). We demonstrate the accuracy and precision of this method through analysis of D-labeled and independently analyzed propanes. In the exchange experiments, propane was heated (100-200 oC) either alone or in the presence of D-enriched water (δD=1,1419 ‰ SMOW), with or without one of several potentially catalytic substrates for hours to weeks. Propane was found to exchange hydrogen with water vigorously at 200 °C in the presence of metal catalysts. In the presence of Ni catalyst, methylene hydrogen exchanges 2.5 times faster than methyl hydrogen. Hydrogen exchange in the presence of Pd catalyst is more effective and can equilibrate hydrogen isotope distribution on propane on the order of 7 days. Isotopic exchange in the presence of natural materials have also been tested, but is only measurable in the methylene group at 200 °C. High catalytic activity of Pd permits attainment of a bracketed, time-invariant equilibrium state that we use to calibrate the site

  1. Effects of surface roughening on the mass transport and mechanical properties of ionic polymer-metal composite

    Science.gov (United States)

    Chang, Longfei; Asaka, Kinji; Zhu, Zicai; Wang, Yanjie; Chen, Hualing; Li, Dichen

    2014-06-01

    Ionic Polymer-Metal Composite (IPMC) has been well-documented of being a promising functional material in extensive applications. In its most popular and traditional manufacturing technique, roughening is a key process to ensure a satisfying performance. In this paper, based on a lately established multi-physical model, the effect of roughening process on the inner mass transportation and the electro-active output of IPMC were investigated. In the model, the electro-chemical field was monitored by Poisson equation and a properly simplified Nernst-Planck equation set, while the mechanical field was evaluated on the basis of volume strain effect. Furthermore, with Ramo-Shockley theorem, the out-circuit current and accumulated charge on the electrode were bridged with the inner cation distribution. Besides, nominal current and charge density as well as the curvature of the deformation were evaluated to characterize the performance of IPMC. The simulation was implemented by Finite Element Method with Comsol Multi-physics, based on two groups of geometrical models, those with various rough interface and those with different thickness. The results of how the roughening impact influences on the performance of IPMC were discussed progressively in three aspects, steady-state distribution of local potential and mass concentration, current response and charge accumulation, as well as the curvature of deformation. Detailed explanations for the performance improvement resulted from surface roughening were provided from the micro-distribution point of view, which can be further explored for the process optimization of IPMC.

  2. Analysis of the fatty acid composition of taraxicuum officinale flowers oil by gas chromatography mass spectrometer

    International Nuclear Information System (INIS)

    Hussain, I.; Ullah, R.

    2013-01-01

    Taraxicum officinale, is a highly valuable medicinal plant. The roots is an important herbal drug, having long been used on the continent as a remedy for liver complaints. Keeping in view the importance and wide applications in the pharmaceutical industries, the present study was therefore aimed to analyze the chemical constituents of the flowers of T. officinale. The T. officinale flowers oil constituents of methyl ester derivatives of fatty acids were analyzed applying gas chromatography coupled to mass spectrometer. The results obtained showed the presence of both containing the saturated as well as unsaturated fatty acids in T. officinale flower oils. A total of 19 different components were identified and quantified. The concentration level of Methyl ester of Lenolenic acid was found very effective in concentration 3.33%, among the identified analytes of interest. In addition, the level of other chemical constituents of methyl ester of palmitic acid 3.11%, myristic acid 1.87, linolenic acids 1.67%, stearic acid 0.97 were found. The concentration level of the rest of identified fatty acids analytes were below 1%. Thus the results obtained from the current initiative is very promising due to the presence of high percentage of valuable analytes concentrations recorded in the fatty acid of T. officinale flower oil. Thus due to the presence of highly important analytes which have increased their importance for consumption in the pharmaceuticals as well as its applications in the new formulations for different skin, cosmetics and health purposes and for use by local practioners. The study will also provide a scientific database line. (author)

  3. CHEMICAL COMPOSITION OF INTERMEDIATE-MASS STAR MEMBERS OF THE M6 (NGC 6405) OPEN CLUSTER

    Energy Technology Data Exchange (ETDEWEB)

    Kılıçoğlu, T.; Albayrak, B. [Ankara University, Faculty of Science, Department of Astronomy and Space Sciences, 06100, Tandoğan, Ankara (Turkey); Monier, R. [LESIA, UMR 8109, Observatoire de Paris Meudon, Place J. Janssen, Meudon (France); Richer, J. [Département de physique, Université de Montréal, 2900, Boulevard Edouard-Montpetit, Montréal QC, H3C 3J7 (Canada); Fossati, L., E-mail: tkilicoglu@ankara.edu.tr, E-mail: balbayrak@ankara.edu.tr, E-mail: Richard.Monier@obspm.fr, E-mail: Jacques.Richer@umontreal.ca, E-mail: lfossati@astro.uni-bonn.de [Argelander-Institut für Astronomie der Universität Bonn, Auf dem Hügel 71, D-53121, Bonn (Germany)

    2016-03-15

    We present here the first abundance analysis of 44 late B-, A-, and F-type members of the young open cluster M6 (NGC 6405, age about 75 Myr). Low- and medium-resolution spectra, covering the 4500–5840 Å wavelength range, were obtained using the FLAMES/GIRAFFE spectrograph attached to the ESO Very Large Telescopes. We determined the atmospheric parameters using calibrations of the Geneva photometry and by adjusting the H{sub β} profiles to synthetic ones. The abundances of up to 20 chemical elements, from helium to mercury, were derived for 19 late B, 16 A, and 9 F stars by iteratively adjusting synthetic spectra to the observations. We also derived a mean cluster metallicity of [Fe/H] = 0.07 ± 0.03 dex from the iron abundances of the F-type stars. We find that for most chemical elements, the normal late B- and A-type stars exhibit larger star-to-star abundance variations than the F-type stars probably because of the faster rotation of the B and A stars. The abundances of C, O, Mg, Si, and Sc appear to be anticorrelated with that of Fe, while the opposite holds for the abundances of Ca, Ti, Cr, Mn, Ni, Y, and Ba as expected if radiative diffusion is efficient in the envelopes of these stars. In the course of this analysis, we discovered five new peculiar stars: one mild Am, one Am, and one Fm star (HD 318091, CD-32 13109, GSC 07380-01211, CP1), one HgMn star (HD 318126, CP3), and one He-weak P-rich (HD 318101, CP4) star. We also discovered a new spectroscopic binary, most likely a SB2. We performed a detailed modeling of HD 318101, the new He-weak P-rich CP star, using the Montréal stellar evolution code XEVOL which self-consistently treats all particle transport processes. Although the overall abundance pattern of this star is properly reproduced, we find that detailed abundances (in particular the high P excess) resisted modeling attempts even when a range of turbulence profiles and mass-loss rates were considered. Solutions are proposed which are

  4. Validation of spectroscopic gas analyzer accuracy using gravimetric standard gas mixtures: impact of background gas composition on CO2 quantitation by cavity ring-down spectroscopy

    Science.gov (United States)

    Lim, Jeong Sik; Park, Miyeon; Lee, Jinbok; Lee, Jeongsoon

    2017-12-01

    The effect of background gas composition on the measurement of CO2 levels was investigated by wavelength-scanned cavity ring-down spectrometry (WS-CRDS) employing a spectral line centered at the R(1) of the (3 00 1)III ← (0 0 0) band. For this purpose, eight cylinders with various gas compositions were gravimetrically and volumetrically prepared within 2σ = 0.1 %, and these gas mixtures were introduced into the WS-CRDS analyzer calibrated against standards of ambient air composition. Depending on the gas composition, deviations between CRDS-determined and gravimetrically (or volumetrically) assigned CO2 concentrations ranged from -9.77 to 5.36 µmol mol-1, e.g., excess N2 exhibited a negative deviation, whereas excess Ar showed a positive one. The total pressure broadening coefficients (TPBCs) obtained from the composition of N2, O2, and Ar thoroughly corrected the deviations up to -0.5 to 0.6 µmol mol-1, while these values were -0.43 to 1.43 µmol mol-1 considering PBCs induced by only N2. The use of TPBC enhanced deviations to be corrected to ˜ 0.15 %. Furthermore, the above correction linearly shifted CRDS responses for a large extent of TPBCs ranging from 0.065 to 0.081 cm-1 atm-1. Thus, accurate measurements using optical intensity-based techniques such as WS-CRDS require TPBC-based instrument calibration or use standards prepared in the same background composition of ambient air.

  5. Improving shuffler assay accuracy

    International Nuclear Information System (INIS)

    Rinard, P.M.

    1995-01-01

    Drums of uranium waste should be disposed of in an economical and environmentally sound manner. The most accurate possible assays of the uranium masses in the drums are required for proper disposal. The accuracies of assays from a shuffler are affected by the type of matrix material in the drums. Non-hydrogenous matrices have little effect on neutron transport and accuracies are very good. If self-shielding is known to be a minor problem, good accuracies are also obtained with hydrogenous matrices when a polyethylene sleeve is placed around the drums. But for those cases where self-shielding may be a problem, matrices are hydrogenous, and uranium distributions are non-uniform throughout the drums, the accuracies are degraded. They can be greatly improved by determining the distributions of the uranium and then applying correction factors based on the distributions. This paper describes a technique for determining uranium distributions by using the neutron count rates in detector banks around the waste drum and solving a set of overdetermined linear equations. Other approaches were studied to determine the distributions and are described briefly. Implementation of this correction is anticipated on an existing shuffler next year

  6. A composition dependent energy scale and the determination of the cosmic ray primary mass in the ankle region

    Science.gov (United States)

    Supanitsky, A. D.; Etchegoyen, A.; Melo, D.; Sanchez, F.

    2015-08-01

    At present there are still several open questions about the origin of the ultra high energy cosmic rays. However, great progress in this area has been made in recent years due to the data collected by the present generation of ground based detectors like the Pierre Auger Observatory and Telescope Array. In particular, it is believed that the study of the composition of the cosmic rays as a function of energy can play a fundamental role for the understanding of the origin of the cosmic rays. The observatories belonging to this generation are composed of arrays of surface detectors and fluorescence telescopes. The duty cycle of the fluorescence telescopes is ∼10% in contrast with the ∼100% of the surface detectors. Therefore, the energy calibration of the events observed by the surface detectors is performed by using a calibration curve obtained from a set of high quality events observed in coincidence by both types of detectors. The advantage of this method is that the reconstructed energy of the events observed by the surface detectors becomes almost independent of simulations of the showers because just a small part of the reconstructed energy (the missing energy), obtained from the fluorescence telescopes, comes from simulations. However, the calibration curve obtained in this way depends on the composition of the cosmic rays, which can introduce biases in composition analyses when parameters with a strong dependence on primary energy are considered. In this work we develop an analytical method to study these effects. We consider AMIGA (Auger Muons and Infill for the Ground Array), the low energy extension of the Pierre Auger Observatory corresponding to the surface detectors, to illustrate the use of the method. In particular, we study the biases introduced by an energy calibration dependent on composition on the determination of the mean value of the number of muons, at a given distance to the showers axis, which is one of the parameters most sensitive to

  7. Testing the accuracy of correlations for multicomponent mass transport of adsorbed gases in metal-organic frameworks: diffusion of H2/CH4 mixtures in CuBTC.

    Science.gov (United States)

    Keskin, Seda; Liu, Jinchen; Johnson, J Karl; Sholl, David S

    2008-08-05

    Mass transport of chemical mixtures in nanoporous materials is important in applications such as membrane separations, but measuring diffusion of mixtures experimentally is challenging. Methods that can predict multicomponent diffusion coefficients from single-component data can be extremely useful if these methods are known to be accurate. We present the first test of a method of this kind for molecules adsorbed in a metal-organic framework (MOF). Specifically, we examine the method proposed by Skoulidas, Sholl, and Krishna (SSK) ( Langmuir, 2003, 19, 7977) by comparing predictions made with this method to molecular simulations of mixture transport of H 2/CH 4 mixtures in CuBTC. These calculations provide the first direct information on mixture transport of any species in a MOF. The predictions of the SSK approach are in good agreement with our direct simulations of binary diffusion, suggesting that this approach may be a powerful one for examining multicomponent diffusion in MOFs. We also use our molecular simulation data to test the ideal adsorbed solution theory method for predicting binary adsorption isotherms and a method for predicting mixture self-diffusion coefficients.

  8. Comparison of Pyrolysis Mass Spectrometry and Near Infrared Spectroscopy for Genetic Analysis of Lignocellulose Chemical Composition in Populus

    Directory of Open Access Journals (Sweden)

    Jianxing Zhang

    2014-03-01

    Full Text Available Genetic analysis of wood chemical composition is often limited by the cost and throughput of direct analytical methods. The speed and low cost of Fourier transform near infrared (FT-NIR overcomes many of these limitations, but it is an indirect method relying on calibration models that are typically developed and validated with small sample sets. In this study, we used >1500 young greenhouse grown trees from a clonally propagated single Populus family, grown at low and high nitrogen, and compared FT-NIR calibration sample sizes of 150, 250, 500 and 750 on calibration and prediction model statistics, and heritability estimates developed with pyrolysis molecular beam mass spectrometry (pyMBMS wood chemical composition. As calibration sample size increased from 150 to 750, predictive model statistics improved slightly. Overall, stronger calibration and prediction statistics were obtained with lignin, S-lignin, S/G ratio, and m/z 144 (an ion from cellulose, than with C5 and C6 carbohydrates, and m/z 114 (an ion from xylan. Although small differences in model statistics were observed between the 250 and 500 sample calibration sets, when predicted values were used for calculating genetic control, the 500 sample set gave substantially more similar results to those obtained with the pyMBMS data. With the 500 sample calibration models, genetic correlations obtained with FT-NIR and pyMBMS methods were similar. Quantitative trait loci (QTL analysis with pyMBMS and FT-NIR predictions identified only three common loci for lignin traits. FT-NIR identified four QTLs that were not found with pyMBMS data, and these QTLs were for the less well predicted carbohydrate traits.

  9. Development of a data independent acquisition mass spectrometry workflow to enable glycopeptide analysis without predefined glycan compositional knowledge.

    Science.gov (United States)

    Lin, Chi-Hung; Krisp, Christoph; Packer, Nicolle H; Molloy, Mark P

    2018-02-10

    Glycoproteomics investigates glycan moieties in a site specific manner to reveal the functional roles of protein glycosylation. Identification of glycopeptides from data-dependent acquisition (DDA) relies on high quality MS/MS spectra of glycopeptide precursors and often requires manual validation to ensure confident assignments. In this study, we investigated pseudo-MRM (MRM-HR) and data-independent acquisition (DIA) as alternative acquisition strategies for glycopeptide analysis. These approaches allow data acquisition over the full MS/MS scan range allowing data re-analysis post-acquisition, without data re-acquisition. The advantage of MRM-HR over DDA for N-glycopeptide detection was demonstrated from targeted analysis of bovine fetuin where all three N-glycosylation sites were detected, which was not the case with DDA. To overcome the duty cycle limitation of MRM-HR acquisition needed for analysis of complex samples such as plasma we trialed DIA. This allowed development of a targeted DIA method to identify N-glycopeptides without pre-defined knowledge of the glycan composition, thus providing the potential to identify N-glycopeptides with unexpected structures. This workflow was demonstrated by detection of 59 N-glycosylation sites from 41 glycoproteins from a HILIC enriched human plasma tryptic digest. 21 glycoforms of IgG1 glycopeptides were identified including two truncated structures that are rarely reported. We developed a data-independent mass spectrometry workflow to identify specific glycopeptides from complex biological mixtures. The novelty is that this approach does not require glycan composition to be pre-defined, thereby allowing glycopeptides carrying unexpected glycans to be identified. This is demonstrated through the analysis of immunoglobulins in human plasma where we detected two IgG1 glycoforms that are rarely observed. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Chemical composition and characteristics of ambient aerosols and rainwater residues during Indian summer monsoon: Insight from aerosol mass spectrometry

    Science.gov (United States)

    Chakraborty, Abhishek; Gupta, Tarun; Tripathi, Sachchida N.

    2016-07-01

    Real time composition of non-refractory submicron aerosol (NR-PM1) is measured via Aerosol mass spectrometer (AMS) for the first time during Indian summer monsoon at Kanpur, a polluted urban location located at the heart of Indo Gangetic Plain (IGP). Submicron aerosols are found to be dominated by organics followed by nitrate. Source apportionment of organic aerosols (OA) via positive matrix factorization (PMF) revealed several types of secondary/oxidized and primary organic aerosols. On average, OA are completely dominated by oxidized OA with a very little contribution from biomass burning OA. During rain events, PM1 concentration is decreased almost by 60%, but its composition remains nearly the same. Oxidized OA showed slightly more decrease than primary OAs, probably due to their higher hygroscopicity. The presence of organo nitrates (ON) is also detected in ambient aerosols. Apart from real-time sampling, collected fog and rainwater samples were also analyzed via AMS in offline mode and in the ICP-OES (Inductively coupled plasma - Optical emission spectrometry) for elements. The presence of sea salt, organo nitrates and sulfates has been observed. Rainwater residues are also dominated by organics but their O/C ratios are 15-20% lower than the observed values for ambient OA. Alkali metals such as Ca, Na, K are found to be most abundant in the rainwater followed by Zn. Rainwater residues are also found to be much less oxidized than the aerosols present inside the fog water, indicating presence of less oxidized organics. These findings indicate that rain can act as an effective scavenger of different types of pollutants even for submicron particle range. Rainwater residues also contain organo sulfates which indicate that some portion of the dissolved aerosols has undergone aqueous processing, possibly inside the cloud. Highly oxidized and possibly hygroscopic OA during monsoon period compared to other seasons (winter, post monsoon), indicates that they can act

  11. Analysis of cloud condensation nuclei composition and growth kinetics using a pumped counterflow virtual impactor and aerosol mass spectrometer

    Directory of Open Access Journals (Sweden)

    J. G. Slowik

    2011-08-01

    Full Text Available We present a new method of determining the size and composition of CCN-active aerosol particles. Method utility is illustrated through a series of ambient measurements. A continuous-flow thermal-gradient diffusion chamber (TGDC, pumped counterflow virtual impactor (PCVI, and Aerodyne time-of-flight mass spectrometer (AMS are operated in series. Ambient particles are sampled into the TGDC, where a constant supersaturation is maintained, and CCN-active particles grow to ~2.5 ± 0.5 μm. The output flow from the TGDC is directed into the PCVI, where a counterflow of dry N2 gas opposes the particle-laden flow, creating a region of zero axial velocity. This stagnation plane can only be traversed by particles with sufficient momentum, which depends on their size. Particles that have activated in the TGDC cross the stagnation plane and are entrained in the PCVI output flow, while the unactivated particles are diverted to a pump. Because the input gas is replaced by the counterflow gas with better than 99 % efficiency at the stagnation plane, the output flow consists almost entirely of dry N2 and water evaporates from the activated particles. In this way, the system yields an ensemble of CCN-active particles whose chemical composition and size are analyzed using the AMS. Measurements of urban aerosol in downtown Toronto identified an external mixture of CCN-active particles consisting almost entirely of ammonium nitrate and ammonium sulfate, with CCN-inactive particles of the same size consisting of a mixture of ammonium nitrate, ammonium sulfate, and organics. We also discuss results from the first field deployment of the TGDC-PCVI-AMS system, conducted from mid-May to mid-June 2007 in Egbert, Ontario, a semirural site ~80 km north of Toronto influenced both by clean air masses from the north and emissions from the city. Organic-dominated particles sampled during a major biogenic event exhibited higher CCN activity and/or faster

  12. Gaseous and particulate composition of fresh and aged emissions of diesel, RME and CNG buses using Chemical Ionization Mass Spectrometry

    Science.gov (United States)

    Psichoudaki, Magda; Le Breton, Michael; Hallquist, Mattias; Watne, Ågot; Hallquist, Asa

    2016-04-01

    Urban air pollution is becoming a significant global problem, especially for large cities around the world. Traffic emissions contribute significantly to both elevated particle concentrations and to gaseous pollutants in cities. The latter also have the potential of forming more particulate mass via their photochemical oxidation in the atmosphere. The International Agency for Research on Cancer and the US EPA have characterised diesel exhausts as a likely human carcinogen that can also contribute to other health problems. In order to meet the challenges with increased transportation and enhanced greenhouse gas emissions, the European Union have decided on a 10% substitution of traditional fuels in the road transport sector by alternative fuels (e.g. biodiesel, CNG) before the year 2020. However, it is also important to study the influence of fuel switches on other primary pollutants as well as the potential to form secondary aerosol mass. This work focuses on the characterisation of the chemical composition of the gas and the condensed phase of fresh bus emissions during acceleration, in order to mimic the exhaust plume that humans would inhale under realistic conditions. In addition, photochemical aging of the exhaust emissions was achieved by employing a Potential Aerosol Mass (PAM) flow reactor, allowing the characterization of the composition of the corresponding aged emissions. The PAM reactor uses UV lamps and high concentrations of oxidants (OH radicals and O3) to oxidize the organic species present in the chamber. The oxidation that takes place within the reactor can be equivalent to up to one week of atmospheric oxidation. Preliminary tests showed that the oxidation employed in these measurements corresponded to a range from 4 to 8 days in the atmosphere. During June and July 2015, a total of 29 buses, 5 diesel, 13 CNG and 11 RME (rapeseed methyl ester), were tested in two different locations with limited influence from other types of emissions and traffic

  13. Properties of the surface snow in Princess Elizabeth Land, East Antarctica - climate and non-climate dependent variability of the surface mass balance and stable water isotopic composition

    Science.gov (United States)

    Vladimirova, D.; Ekaykin, A.; Lipenkov, V.; Popov, S. V.; Petit, J. R.; Masson-Delmotte, V.

    2017-12-01

    Glaciological and meteorological observations conducted during the past four decades in Princess Elizabeth Land, East Antarctica, are compiled. The database is used to investigate spatial patterns of surface snow isotopic composition and surface mass balance, including detailed information near subglacial lake Vostok. We show diverse relationships between snow isotopic composition and surface temperature. In the most inland part (elevation 3200-3400 m a.s.l.), surface snow isotopic composition varies independently from surface temperature, and is closely related to the distance to the open water source (with a slope of 0.98±0.17 ‰ per 100 km). Surface mass balance values are higher along the ice sheet slope, and relatively evenly distributed inland. The minimum values of snow isotopic composition and surface mass balance are identified in an area XX km southwestward from Vostok station. The spatial distribution of deuterium excess delineates regions influenced by the Indian Ocean and Pacific Ocean air masses, with Vostok area being situated close to their boundary. Anomalously high deuterium excess values are observed near Dome A, suggesting high kinetic fractionation for its moisture source, or specifically high post-deposition artifacts. The dataset is available for further studies such as the assessment of skills of general circulation or regional atmospheric models, and the search for the oldest ice.

  14. "Dilute-and-inject" multi-target screening assay for highly polar doping agents using hydrophilic interaction liquid chromatography high resolution/high accuracy mass spectrometry for sports drug testing.

    Science.gov (United States)

    Görgens, Christian; Guddat, Sven; Orlovius, Anne-Katrin; Sigmund, Gerd; Thomas, Andreas; Thevis, Mario; Schänzer, Wilhelm

    2015-07-01

    In the field of LC-MS, reversed phase liquid chromatography is the predominant method of choice for the separation of prohibited substances from various classes in sports drug testing. However, highly polar and charged compounds still represent a challenging task in liquid chromatography due to their difficult chromatographic behavior using reversed phase materials. A very promising approach for the separation of hydrophilic compounds is hydrophilic interaction liquid chromatography (HILIC). Despite its great potential and versatile advantages for the separation of highly polar compounds, HILIC is up to now not very common in doping analysis, although most manufacturers offer a variety of HILIC columns in their portfolio. In this study, a novel multi-target approach based on HILIC high resolution/high accuracy mass spectrometry is presented to screen for various polar stimulants, stimulant sulfo-conjugates, glycerol, AICAR, ethyl glucuronide, morphine-3-glucuronide, and myo-inositol trispyrophosphate after direct injection of diluted urine specimens. The usage of an effective online sample cleanup and a zwitterionic HILIC analytical column in combination with a new generation Hybrid Quadrupol-Orbitrap® mass spectrometer enabled the detection of highly polar analytes without any time-consuming hydrolysis or further purification steps, far below the required detection limits. The methodology was fully validated for qualitative and quantitative (AICAR, glycerol) purposes considering the parameters specificity; robustness (rRT  0.99); intra- and inter-day precision at low, medium, and high concentration levels (CV < 20%); limit of detection (stimulants and stimulant sulfo-conjugates < 10 ng/mL; norfenefrine; octopamine < 30 ng/mL; AICAR < 10 ng/mL; glycerol 100 μg/mL; ETG < 100 ng/mL); accuracy (AICAR 103.8-105.5%, glycerol 85.1-98.3% at three concentration levels) and ion suppression/enhancement effects.

  15. Beyond Body Mass Index: Using Anthropometric Measures and Body Composition Indicators to Assess Odds of an Endometriosis Diagnosis.

    Science.gov (United States)

    Backonja, Uba; Hediger, Mary L; Chen, Zhen; Lauver, Diane R; Sun, Liping; Peterson, C Matthew; Buck Louis, Germaine M

    2017-09-01

    Body mass index (BMI) and endometriosis have been inversely associated. To address gaps in this research, we examined associations among body composition, endometriosis, and physical activity. Women from 14 clinical sites in the Salt Lake City, Utah and San Francisco, California areas and scheduled for laparoscopy/laparotomy were recruited during 2007-2009. Participants (N = 473) underwent standardized anthropometric assessments to estimate body composition before surgery. Using a cross-sectional design, odds of an endometriosis diagnosis (adjusted odds ratio [aOR]; 95% confidence interval [CI]) were calculated for anthropometric and body composition measures (weight in kg; height in cm; mid upper arm, waist, hip, and chest circumferences in cm; subscapular, suprailiac, and triceps skinfold thicknesses in mm; arm muscle and fat areas in cm 2 ; centripetal fat, chest-to-waist, chest-to-hip, waist-to-hip, and waist-to-height ratios; arm fat index; and BMI in kg/m 2 ). Physical activity (metabolic equivalent of task-minutes/week) and sedentariness (average minutes sitting on a weekday) were assessed using the International Physical Activity Questionnaire-Short Form. Measures were modeled continuously and in quartiles based on sample estimates. Adjusted models were controlled for age (years, continuous), site (Utah/California), smoking history (never, former, or current smoker), and income (below, within 180%, and above of the poverty line). Findings were standardized by dividing variables by their respective standard deviations. We used adjusted models to examine whether odds of an endometriosis diagnosis were moderated by physical activity or sedentariness. Inverse relationships were observed between endometriosis and standardized: weight (aOR = 0.71, 95% CI 0.57-0.88); subscapular skinfold thickness (aOR = 0.79, 95% CI 0.65-0.98); waist and hip circumferences (aOR = 0.79, 95% CI 0.64-0.98 and aOR = 0.76, 95% CI 0.61-0.94, respectively); total

  16. Molecular composition of rainwater and aerosol during rain events in León, Spain, using high resolution mass spectrometry.

    Science.gov (United States)

    Fee, Anna

    2017-04-01

    Anna Fee (1), Markus Kalberer (1), Roberto Fraile (2), Amaya Castro (2), Ana. I. Calvo (2), Carlos Blanco-Alegre (2), Fernanda Oduber (2) and Mário Cerqueira (3). 1 Department of Chemistry, University of Cambridge, UK. 2 Department of Applied Chemistry and Physics, IMARENAB, University of León, Spain. 3 Department of Environmental Planning, University of Aveiro, Portugal. A wide range of atmospheric compounds which are present in rainwater are often also present in aerosol. They can be taken up during cloud droplet formation (in-cloud scavenging) or washed out during precipitation (below-cloud scavenging). Such compounds including aromatic hydrocarbons and organic nitrogen containing compounds are hazardous to health. In this study, the organic chemical composition of rainwater and aerosol from rain events in León, Spain, is being analysed using high resolution mass spectrometry. Collected rainwater along with high volume and low volume filters from rain events which occurred during spring, summer and winter of 2016 have been selected for analysis. Rainwater samples were prepared using Polymeric Reversed Phase Solid Phase Extraction (SPE) and filters have been extracted in water with and without SPE. Three different SPE polymer based sorbents were tested; one for extracting neutral compounds and two which are more suitable for extracting organic compounds containing sulphate and other polar functional groups. The sorbent for extracting neutral compounds was found to yield a higher number of compounds from the sample extraction than the other two varieties. Kendrick masses, Van Krevelen plots and carbon oxidation states have been investigated to identify compounds and patterns. Preliminary results show a predominance in peaks with O/C ratios between 0.2 and 0.7 and H/C ratios between 1 and 2 in both rain and aerosol samples which indicates substituted aromatic compounds. Cellulose material and fatty acids may also be present. The rain samples also have a

  17. The composition of bile acids in patients with cholelithiasis according to the data of liquid chromatography with mass spectrometric detection

    Directory of Open Access Journals (Sweden)

    V. M. Klymenko

    2017-12-01

    Full Text Available Bile acids play a leading role in the physical and colloidal properties of bile stabilization. Lack of bile acids consequences result in the formation of cholesterol stones in the gall bladder, diarrhea and steatorrhea, fat-soluble vitamins impaired absorption, and kidney stones formation (oxalates. Investigation of altered bile composition, especially the content of bile acids, in patients with gallstone disease by means of modern analytical analysis methods (liquid chromatography with mass spectrometric detection would complement the modern ideas about mechanisms of lithogenesis and aim efforts at prevention of stone formation in the gall bladder, that was the purpose of our work. Materials and methods. Bile samples were tested for bile acid content using liquid chromatography with mass spectrometry. 14 samples of bile from patients with cholelithiasis were included in the main group, and control group consisted of 7 bile samples from practically healthy persons. Results. In patients with cholelithiasis there is an increase in the content of conjugated forms of bile acids – glycolic acid in 2 times (p = 0.002, taurocholic acid in 1.57 times (p = 0.062 compared with practically healthy persons. In patients with cholelithiasis, the ratio of taurocholic to glycolic acidі content (0.95 vs. 1.27, p = 0.0179, as well as glycogenodeoxycholic to glycodeoxycholic acid (1.11 vs. 1.58, p = 0.027 is significantly less than that in practically healthy persons. In addition, one in two patients with cholelithiasis does not reveal the presence of ursodeoxycholic acid in the bile. Conclusions. The lithogenic properties of bile are primarily caused by conjugated forms of cholic acid with glycine and taurine content violation. The ratio of taurocholic to glycolic acid content in patients with cholelithiasis is significantly lower than the similar index in practically healthy persons (0.95 vs. 1.27, p = 0.0179. The ratio of glycine conjugated bile acids

  18. New air Cherenkov light detectors to study mass composition of cosmic rays with energies above knee region

    Energy Technology Data Exchange (ETDEWEB)

    Tsunesada, Yoshiki, E-mail: tsunesada@cr.phys.titech.ac.jp [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8550 Japan (Japan); Katsuya, Ryoichi, E-mail: katsuya@cr.phys.titech.ac.jp [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8550 Japan (Japan); Mitsumori, Yu; Nakayama, Keisuke; Kakimoto, Fumio; Tokuno, Hisao [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8550 Japan (Japan); Tajima, Norio [RIKEN, Wako, Saitama 351-0198 (Japan); Miranda, Pedro; Salinas, Juan; Tavera, Wilfredo [Instituto de Investigaciones Físicas, Universidad Mayor de San Andrés, La Paz (Bolivia, Plurinational State of)

    2014-11-01

    We have installed a hybrid detection system for air showers generated by cosmic rays with energies greater than 3×10{sup 15}eV at Mount Chacaltaya (5200 m above the sea level), in order to study the mass composition of cosmic rays above the knee region. This detection system comprises an air shower array with 49 scintillation counters in an area of 500 m×650 m, and seven new Cherenkov light detectors installed in a radial direction from the center of the air shower array with a separation of 50 m. It is known that the longitudinal development of a particle cascade in the atmosphere strongly depends on the type of the primary nucleus, and an air shower initiated by a heavier nucleus develops faster than that by a lighter primary of the same energy, because of the differences in the interaction cross-section and the energy per nucleon. This can be measured by detecting the Cherenkov radiation emitted from charged particles in air showers at higher altitudes. In this paper we describe the design and performance of our new non-imaging Cherenkov light detectors at Mount Chacaltaya that are operated in conjunction with the air shower array. The arrival directions and energies of air showers are determined by the shower array, and information about the primary masses is obtained from the Cherenkov light data including the time profiles and lateral distributions. The detector consists of photomultiplier tube (PMT), high-speed ADCs, other control modules, and data storage device. The Cherenkov light signals from an air shower are typically 10–100 ns long, and the waveforms are digitized with a sampling frequency of 1 GHz and recorded in situ without long-distance analog signal transfers. All the Cherenkov light detectors record their time-series data by receiving a triggering signal transmitted from the trigger module of the air shower array, which is fired by a coincidence of shower signals in four neighboring scintillation counters. The optical characteristics of the

  19. Accuracy of two optical chlorophyll meters in predicting chemical composition and in vitro ruminal organic matter degradability of Brachiaria hybrid, Megathyrsus maximus, and Paspalum atratum

    Directory of Open Access Journals (Sweden)

    Martin P. Hughes

    2017-03-01

    Full Text Available The objective of this study was to determine the accuracy and reliability of 2 optical chlorophyll meters: FieldScout CM 1,000 NDVI and Yara N-Tester, in predicting neutral detergent fibre (NDF, acid detergent fibre (ADF, acid detergent lignin (ADL, acid detergent insoluble nitrogen (ADIN and in vitro ruminal organic matter degradability (IVOMD of 3 tropical grasses. Optical chlorophyll measurements were taken at 3 stages (4, 8 and 12 weeks of regrowth in Brachiaria hybrid, and Megathyrsus maximus and at 6 and 12 weeks of regrowth in Paspalum atratum (cv. Ubon. Optical chlorophyll measurements showed the highest correlation (r = 0.57 to 0.85 with NDF concentration. The FieldScout CM 1,000 NDVI was better than the Yara N-Tester in predicting NDF (R2 = 0.70 and ADF (R2 = 0.79 concentrations in Brachiaria hybrid and NDF (R2 = 0.79 in M. maximus. Similarly, FieldScout CM 1,000 NDVI produced better estimates of 24 h IVOMD (IVOMD24h in Brachiaria hybrid (R2 = 0.81 and IVOMD48h in Brachiaria hybrid (R2 = 0.65 and M. maximus (R2 = 0.75. However, these prediction models had relatively low concordance correlation coefficients, i.e., CCC >0.90, but random errors were the main source of bias. It was, therefore, concluded that both optical chlorophyll meters were poor and unreliable predictors of ADIN and ADL concentrations. Overall, the FieldScout CM 1,000 NDVI shows potential to produce useful estimates of IVOMD24h and ADF in Brachiaria hybrid and IVOMD48h and NDF concentrations in M. maximus.

  20. Direct surface analysis coupled to high-resolution mass spectrometry reveals heterogeneous composition of the cuticle of Hibiscus trionum petals.

    Science.gov (United States)

    Giorio, Chiara; Moyroud, Edwige; Glover, Beverley J; Skelton, Paul C; Kalberer, Markus

    2015-10-06

    Plant cuticle, which is the outermost layer covering the aerial parts of all plants including petals and leaves, can present a wide range of patterns that, combined with cell shape, can generate unique physical, mechanical, or optical properties. For example, arrays of regularly spaced nanoridges have been found on the dark (anthocyanin-rich) portion at the base of the petals of Hibiscus trionum. Those ridges act as a diffraction grating, producing an iridescent effect. Because the surface of the distal white region of the petals is smooth and noniridescent, a selective chemical characterization of the surface of the petals on different portions (i.e., ridged vs smooth) is needed to understand whether distinct cuticular patterns correlate with distinct chemical compositions of the cuticle. In the present study, a rapid screening method has been developed for the direct surface analysis of Hibiscus trionum petals using liquid extraction surface analysis (LESA) coupled with high-resolution mass spectrometry. The optimized method was used to characterize a wide range of plant metabolites and cuticle monomers on the upper (adaxial) surface of the petals on both the white/smooth and anthocyanic/ridged regions, and on the lower (abaxial) surface, which is entirely smooth. The main components detected on the surface of the petals are low-molecular-weight organic acids, sugars, and flavonoids. The ridged portion on the upper surface of the petal is enriched in long-chain fatty acids, which are constituents of the wax fraction of the cuticle. These compounds were not detected on the white/smooth region of the upper petal surface or on the smooth lower surface.

  1. Mass, black carbon and elemental composition of PM{sub 2.5} at an industrial site in Kingston, Jamaica

    Energy Technology Data Exchange (ETDEWEB)

    Boman, Johan, E-mail: johan.boman@chem.gu.se; Gaita, Samuel M.

    2015-11-15

    An estimated three million premature deaths yearly can be attributed to ambient particulate pollution, a majority of them in low and middle income countries. The rapid increase in the vehicle fleet in urban areas of the Caribbean countries have experienced contributes to the bad urban air quality. In this study aerosol particles with an aerodynamic diameter smaller than, or equal to, 2.5 μm (PM{sub 2.5}) were collected over 24 h at a site along Spanish Town Road, one of the main commuter roads in Kingston, Jamaica. The study was aimed at determining the mass, black carbon and elemental composition of PM{sub 2.5} in Kingston. Although lead in the gasoline was phased out in the year 2000, up to 5000 ppm of sulfur is still allowed in the diesel, leading to an extensive secondary particle formation. PM{sub 2.5} samples were collected using a Mini-vol sampler between 12 December 2013 and 21 March 2014 and analyzed for trace elements using the Particle-Induced X-ray Emission (PIXE) facility at Lund University, Sweden. Concentrations of Si, S, Cl, K, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Br and Pb were determined. Elemental concentrations showed a high temporal variation and the average PM{sub 2.5} concentration (44 μg m{sup −3}) is higher than the air quality standards that apply in the European Union (25 μg m{sup −3}) and in the USA (12 μg m{sup −3}). From this we can conclude that the air quality in the area is severely influenced by PM{sub 2.5} pollution and that there is a need to develop plans for improving the air quality in Kingston city.

  2. Leg muscle mass and composition in relation to lower extremity performance in men and women aged 70 to 79 : the health, aging and body composition study

    NARCIS (Netherlands)

    Visser, Marjolein; Kritchevsky, Stephen B; Goodpaster, Bret H; Newman, Anne B; Nevitt, Michael; Stamm, Elizabeth; Harris, Tamara B

    OBJECTIVES: The loss of muscle mass with aging, or sarcopenia, is hypothesized to be associated with the deterioration of physical function. Our aim was to determine whether low leg muscle mass and greater fat infiltration in the muscle were associated with poor lower extremity performance (LEP).

  3. Dietary composition modulates brain mass and solubilizable Aβ levels in a mouse model of aggressive Alzheimer's amyloid pathology

    Directory of Open Access Journals (Sweden)

    Buxbaum Joseph D

    2009-10-01

    Full Text Available Abstract Objective Alzheimer's disease (AD is a progressive neurodegenerative disease of the central nervous system (CNS. Recently, an increased interest in the role diet plays in the pathology of AD has resulted in a focus on the detrimental effects of diets high in cholesterol and fat and the beneficial effects of caloric restriction. The current study examines how dietary composition modulates cerebral amyloidosis and neuronal integrity in the TgCRND8 mouse model of AD. Methods From 4 wks until 18 wks of age, male and female TgCRND8 mice were maintained on one of four diets: (1 reference (regular commercial chow; (2 high fat/low carbohydrate custom chow (60 kcal% fat/30 kcal% protein/10 kcal% carbohydrate; (3 high protein/low carbohydrate custom chow (60 kcal% protein/30 kcal% fat/10 kcal% carbohydrate; or (4 high carbohydrate/low fat custom chow (60 kcal% carbohydrate/30 kcal% protein/10 kcal% fat. At age 18 wks, mice were sacrificed, and brains studied for (a wet weight; (b solubilizable Aβ content by ELISA; (c amyloid plaque burden; (d stereologic analysis of selected hippocampal subregions. Results Animals receiving a high fat diet showed increased brain levels of solubilizable Aβ, although we detected no effect on plaque burden. Unexpectedly, brains of mice fed a high protein/low carbohydrate diet were 5% lower in weight than brains from all other mice. In an effort to identify regions that might link loss of brain mass to cognitive function, we studied neuronal density and volume in hippocampal subregions. Neuronal density and volume in the hippocampal CA3 region of TgCRND8 mice tended to be lower in TgCRND8 mice receiving the high protein/low carbohydrate diet than in those receiving the regular chow. Neuronal density and volume were preserved in CA1 and in the dentate gyrus. Interpretation Dissociation of Aβ changes from brain mass changes raises the possibility that diet plays a role not only in modulating amyloidosis but also in

  4. Determination of peak bone mass density and composition in low income urban residents of metro Manila using isotope techniques

    International Nuclear Information System (INIS)

    Lim-Abrahan, M.A.

    2000-01-01

    The work described in this paper is a continuation of the first phase of the study, which is the determination of the peak bone mass density among residents of Metro Manila using dual energy x-ray absorptiometry. However, it also aims to correlate sex, body mass index, nutritional factors, physical activity and lifestyle to peak bone mass and thus attempts to explain any discrepancies in peak bone mass density to that seen in other countries

  5. The loss of skeletal muscle strength, mass, and quality in older adults : the health, aging and body composition study

    NARCIS (Netherlands)

    Goodpaster, Bret H; Park, Seok Won; Harris, Tamara B; Kritchevsky, Steven B; Nevitt, Michael; Schwartz, Ann V; Simonsick, Eleanor M; Tylavsky, Frances A; Visser, Marjolein; Newman, Anne B

    2006-01-01

    BACKGROUND: The loss of muscle mass is considered to be a major determinant of strength loss in aging. However, large-scale longitudinal studies examining the association between the loss of mass and strength in older adults are lacking. METHODS: Three-year changes in muscle mass and strength were

  6. Accuracy of a composite score using daily SAPS II and LOD scores for predicting hospital mortality in ICU patients hospitalized for more than 72 h.

    Science.gov (United States)

    Timsit, J F; Fosse, J P; Troché, G; De Lassence, A; Alberti, C; Garrouste-Orgeas, M; Azoulay, E; Chevret, S; Moine, P; Cohen, Y

    2001-06-01

    training data set [area under the ROC curve: 0.794 (95 % CI: 0.766-0.820), Hosmer-Lemeshow C statistic: 5.56, P = 0.7]. In the validation data set, the model maintained good accuracy [area under the ROC curve: 0.826 (95 % CI: 0.780-0.867), Hosmer-Lemeshow C statistic: 7.14, P = 0.5]. The new model using SAPS II and LOD and their evolution during the first calendar days has good discrimination and calibration properties. We propose its use for benchmarking and evaluating the over-risk of death associated with ICU-acquired nosocomial infections.

  7. Liquid chromatographic/electrospray ionization tandem mass spectrometric study of polyphenolic composition of four cultivars of Fragaria vesca L. berries and their comparative evaluation.

    Science.gov (United States)

    Del Bubba, Massimo; Checchini, Leonardo; Chiuminatto, Ugo; Doumett, Saer; Fibbi, Donatella; Giordani, Edgardo

    2012-09-01

    High-performance liquid chromatography coupled with ion spray mass spectrometry in the tandem mode with both negative and positive ionization was used for investigating a variety of polyphenolic compounds in four genotypes of Fragaria vesca berries. About 60 phenolic compounds belonging to the compound classes of phenolic acids, ellagitannins, ellagic acid derivatives, flavonols, monomeric and oligomeric flavanols, dihydrochalcones and anthocyanins were reported, providing for the first time a quite complete picture of polyphenolic composition of F. vesca berries. Some of the polyphenols herein investigated, such as a tris-galloyl-hexahydroxydiphenoyl-hexose, two castalagin/vescalagin-like isomers and peonidin-malonylglucoside, were described for the first time. Principal component analysis applied on original HPLC-MS/MS data, acquired in multiple reaction monitoring mode, successfully discriminated the four investigated cultivars on the basis of their polyphenolic composition, highlighting the fundamental role of mass spectrometry for food characterization. Copyright © 2012 John Wiley & Sons, Ltd.

  8. Imaging spectroscopy to assess the composition of ice surface materials and their impact on glacier mass balance

    Science.gov (United States)

    Naegeli, Kathrin; Huss, Matthias; Damm, Alexander; de Jong, Rogier; Schaepman, Michael; Hoelzle, Martin

    2014-05-01

    The ice-albedo feedback plays a crucial role in various glaciological processes, but especially influences ice melt. Glacier surface albedo is one of the most important variables in the energy balance of snow and ice, but depends in a complicated way on many factors, such as cryoconite concentration, impurities due to mineral dust, soot or organic matter, grain size or ice surface morphology. Our understanding on how these various factors influence glacier albedo is still limited hindering a spatially and temporally explicit parameterization of energy balance models and requiring strongly simplified assumptions on actual albedo values. Over the last two decades, several studies have focused on glacier surface albedo using automatic in-situ weather stations in combination with radiation measurement setups or satellite images. Due to limitations of both approaches in matching either the spatial or the temporal length scale of glacier albedo, still fairly little is known about the state, changes and impact of glacier surface albedo in the Swiss Alps, although there are obvious changes in surface characteristics on most alpine glaciers over the last years. With use of the APEX (Airborne Prism EXperiment) image spectrometer, measurements of reflected radiation were acquired in high spatial and spectral resolution on Glacier de la Plaine Morte, Switzerland, to explicitly analyse the ice surface. In-situ radiometric measurements were acquired with an ASD field spectrometer in parallel to APEX overflights. These data are intended to be used for validation purposes as well as input data for the linear spectral unmixing analysis of the APEX data. Seasonal glacier mass balance is monitored since five years using the direct glaciological method. This contribution presents a first evaluation of the data collected in summer 2013. The obtained in-situ and airborne reflectance measurements were used in combination with a spectral mixture analysis (SMA) approach to assess the

  9. Forming the Composition of Underground Coal Gasification Products in the Simulation of Various Heat and Mass Transfer Conditions in the Coal Seam

    Directory of Open Access Journals (Sweden)

    Masanik A.S.

    2016-01-01

    Full Text Available The mathematical model describing the heat and mass transfer processes in underground coal gasification is proposed. Numerical studies have allowed to determine the composition of gases depending on the temperature, pressure products of gasification, and the composition of the heated oxidant injected. Relations the composition of the concentration of combustible gas component of the oxidant injected: dry air, a mixture of oxygen, nitrogen and water vapor in different proportions were prepared. It is found that, depending on the oxygen content in the oxidizer low-temperature gasification mode is implemented (up to 15%. At higher values of the oxygen concentration in the oxidizer the high-temperature mode is realized, in which the fuel gas output increases significantly.

  10. Introduction to Body Composition Assessment Using the Deuterium Dilution Technique with Analysis of Urine Samples by Isotope Ratio Mass Spectrometry (French Edition)

    International Nuclear Information System (INIS)

    2013-01-01

    The IAEA has fostered the more widespread use of a stable isotope technique to assess body composition in different population groups to address priority areas in public health nutrition in Member States. It has done this by supporting national and regional nutrition projects through its technical cooperation programme and coordinated research projects over many years. This publication was developed by an international group of experts to provide practical hands-on guidance in the use of this technique in settings where analysis of stable isotope ratios in biological samples is to be made by isotope ratio mass spectrometry. The publication is targeted at new users of this technique, for example nutritionists, analytical chemists and other professionals. More detailed information on the theoretical background and the practical applications of state of the art methodologies to monitor changes in body composition can be found in IAEA Human Health Series No. 3, Assessment of Body Composition and Total Energy Expenditure in Humans by Stable Isotope Techniques

  11. Introduction to Body Composition Assessment Using the Deuterium Dilution Technique with Analysis of Urine Samples by Isotope Ratio Mass Spectrometry (Spanish Edition)

    International Nuclear Information System (INIS)

    2013-01-01

    The IAEA has fostered the more widespread use of a stable isotope technique to assess body composition in different population groups to address priority areas in public health nutrition in Member States. It has done this by supporting national and regional nutrition projects through its technical cooperation programme and coordinated research projects over many years. This publication was developed by an international group of experts to provide practical hands-on guidance in the use of this technique in settings where analysis of stable isotope ratios in biological samples is to be made by isotope ratio mass spectrometry. The publication is targeted at new users of this technique, for example nutritionists, analytical chemists and other professionals. More detailed information on the theoretical background and the practical applications of state of the art methodologies to monitor changes in body composition can be found in IAEA Human Health Series No. 3, Assessment of Body Composition and Total Energy Expenditure in Humans by Stable Isotope Techniques

  12. On the problem of whether mass or chemical bonding is more important to bombardment-induced compositional changes in alloys and oxides

    International Nuclear Information System (INIS)

    Kelly, R.

    1980-01-01

    The bombardment of alloys, oxides, and halides often leads to marked compositional changes at the surface, and these changes have been attributed to an interplay of mass-dependent effects, chemical bonding, electronic processes, and diffusion. We attempt here to answer the limited question of whether, considering only alloys and oxides, mass or bonding is normally more important. The relevant theory is reviewed and extended, with mass effects being shown to be associated most explicitly with recoil sputtering and bonding effects being shown to be associated with all three of cascade sputtering, thermal sputtering, and surface segregation. As far as experimental examples are concerned, mass correlations are found to be quite unsuccessful, whereas most observations can be understood rather well in terms of bonding. Nevertheless, there is a basic problem in that the cascade component of sputtering, normally judged to be predominant, should give significantly less compositional change than is observed. Thermal sputtering would lead to more significant changes, but there is a new problem that, at least with alloys, the absolute yields are probably rather small. A combination of surface segregation with sputtering would also lead to more significant changes, but it is unclear whether segregation is rapid enough to be important in room-temperature bombardments. (orig.)

  13. Syngas fermentation to biofuel: evaluation of carbon monoxide mass transfer and analytical modeling using a composite hollow fiber (CHF) membrane bioreactor.

    Science.gov (United States)

    Munasinghe, Pradeep Chaminda; Khanal, Samir Kumar

    2012-10-01

    In this study, the volumetric mass transfer coefficients (Ka) for CO were examined in a composite hollow fiber (CHF) membrane bioreactor. The mass transfer experiments were conducted at various inlet gas pressures (from 5 to 30 psig (34.5-206.8 kPa(g))) and recirculation flow rates (300, 600, 900, 1200 and 1500 mL/min) through CHF module. The highest Ka value of 946.6 1/h was observed at a recirculation rate of 1500 mL/min and at an inlet gas pressure of 30 psig(206.8 kPa(g)). The findings of this study confirm that the use of CHF membranes is effective and improves the efficiency CO mass transfer into the aqueous phase. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Composite glycerol/graphite/aromatic acid matrices for thin-layer chromatography/matrix-assisted laser desorption/ionization mass spectrometry of heterocyclic compounds.

    Science.gov (United States)

    Esparza, Cesar; Borisov, R S; Varlamov, A V; Zaikin, V G

    2016-10-28

    New composite matrices have been suggested for the analysis of mixtures of different synthetic organic compounds (N-containing heterocycles and erectile dysfunction drugs) by thin layer chromatography/matrix-assisted laser desorption ionization time-of-flight mass spectrometry (TLC/MALDI-TOF). Different mixtures of classical MALDI matrices and graphite particles dispersed in glycerol were used for the registration of MALDI mass spectra directly from TLC plates after analytes separation. In most of cases, the mass spectra possessed [M+H] + ions; however, for some analytes only [M+Na] + and [M+K] + ions were observed. These ions have been used to generate visualized TLC chromatograms. The described approach increases the desorption/ionization efficiencies of analytes separated by TLC, prevent spot blurring, simplifies and decrease time for sample preparation. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Mass-producible method for preparation of a carbon-coated graphite@plasma nano-silicon@carbon composite with enhanced performance as lithium ion battery anode

    International Nuclear Information System (INIS)

    Chen, Hedong; Wang, Zhoulu; Hou, Xianhua; Fu, Lijun; Wang, Shaofeng; Hu, Xiaoqiao; Qin, Haiqing; Wu, Yuping

    2017-01-01

    Carbon-coated core-shell structure artificial graphite@plasma nano-silicon@carbon (AG@PNSi@C) composite, applying as lithium ion battery anode material, has been prepared via spray drying method. The plasma nano-silicon (<100 nm), which contained amorphous silicon, was synthesized by radio frequency induction plasma system with the high temperatures processing capability and high quench rates. The artificial graphite in the composite acts as the core which supports the particle and provides electroconductivity, while PNSi attached on the surface of the core, enhances the specific capacity of the composite. The as prepared composite shows superior performance as anode in lithium-ion batteries, regarding to the initial Coulombic efficiency and cycle life. The initial Coulombic efficiency of AG@PNSi@C electrode is 81.0% with a discharge capacity of 553 mAh g −1 and a recharge capacity of 448 mAh g −1 . During cycling, AG@PNSi@C exhibits excellent performance with a very low capacity fading that the discharge capacity maintains 498.2 mAh g −1 and 449.4 mAh g −1 after 250 cycles and 500 cycles. AG@PNSi@C also shows enhanced resistance against high current density. Besides the remarkable electrochemical performances, the facile and mass-producible synthesis process makes the AG@PNSi@C composite very promising for its application in lithium-ion batteries.

  16. Mass composition studies of Ultra High Energy cosmic rays through the measurement of the Muon Production Depths at the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Collica, Laura [Univ. of Milan (Italy); Paris Diderot Univ. (France)

    2014-01-01

    The Pierre Auger Observatory (Auger) in Argentina studies Ultra High Energy Cosmic Rays (UHECRs) physics. The flux of cosmic rays at these energies (above 1018 eV) is very low (less than 100 particle/km2-year) and UHECR properties must be inferred from the measurements of the secondary particles that the cosmic ray primary produces in the atmosphere. These particles cascades are called Extensive Air Showers (EAS) and can be studied at ground by deploying detectors covering large areas. The EAS physics is complex, and the properties of secondary particles depend strongly on the first interaction, which takes place at an energy beyond the ones reached at accelerators. As a consequence, the analysis of UHECRs is subject to large uncertainties and hence many of their properties, in particular their composition, are still unclear. Two complementary techniques are used at Auger to detect EAS initiated by UHE- CRs: a 3000 km2 surface detector (SD) array of water Cherenkov tanks which samples particles at ground level and fluorescence detectors (FD) which collect the ultraviolet light emitted by the de-excitation of nitrogen nuclei in the atmosphere, and can operate only in clear, moonless nights. Auger is the largest cosmic rays detector ever built and it provides high-quality data together with unprecedented statistics. The main goal of this thesis is the measurement of UHECR mass composition using data from the SD of the Pierre Auger Observatory. Measuring the cosmic ray composition at the highest energies is of fundamental importance from the astrophysical point of view, since it could discriminate between different scenarios of origin and propagation of cosmic rays. Moreover, mass composition studies are of utmost importance for particle physics. As a matter of fact, knowing the composition helps in exploring the hadronic interactions at ultra-high energies, inaccessible to present accelerator experiments.

  17. Assessment of the influence of body composition on bone mass in children and adolescents based on a functional analysis of the muscle-bone relationship.

    Science.gov (United States)

    Golec, Joanna; Chlebna-Sokół, Danuta

    2014-01-01

    The functional model of skeletal development considers the mechanical factor to be the most important skeletal modulant. The aim of the study was a functional analysis of the bone-muscle relationship in children with low and normal bone mass. The study involved 149 children with low and 99 children with normal bone mass (control group). All patients underwent a densitometry examination (DXA). Low bone mass was diagnosed if the Z-score was below values of Z-scores for all parameters in children with low bone mass as compared to the control group. Children with low bone mass had lower content of adipose and muscle tissue and a marked deficit of muscle tissue with regard to height (which according to mechanostat theory leads to lower muscle-generated strain on bones). This group of children had also lower TBBMC/LBM Z-scores, which indicates greater fracture susceptibility. 1. Functional analysis, which showed associations between bone and muscle tissues, can be useful for diagnosing and monitoring skeletal system disorders as well as making therapeutic decisions.2. The study emphasizes the role of proper nutrition and physical activities, which contribute to proper body composition, in the prevention of bone mineralization disorders in childhood and adolescence. 3. The study showed the inadequacy of the classic reference ranges used in interpreting DXA data in children and demonstrated the usefulness of continuous variables for that purpose.

  18. Association of parental body mass index before pregnancy on infant growth and body composition: Evidence from a pregnancy cohort study in Malaysia.

    Science.gov (United States)

    Zalbahar, Nurzalinda; Jan Mohamed, Hamid Jan B; Loy, See Ling; Najman, Jake; McIntyre, Harold David; Mamun, Abdullah

    2016-09-01

    Parental body mass index (BMI) is strongly linked with the development of offspring overweight and obesity. However, there are a limited number of studies focusing on the association of parental body mass index before pregnancy on offspring growth and body composition in early life, particularly in developing countries. Data from the University Sains Malaysia (USM) Pregnancy Cohort which consists of 153 mother-offspring pairs were used. Data were collected using interview-administered questionnaires and anthropometric measurements were also obtained. Multiple linear regression and generalised equation estimation (GEE) were used to examine the direction and impact of the association between parental BMI and child growth and body composition (weight for age, height for age, body mass index for age, weight for height and fat mass at age 2m, 6m, and 12m). Potential confounders, including validated measures of maternal diets and physical activity during pregnancy, were considered. Of 153 parents, one-quarter of the mothers and 42.2% of the fathers, respectively, were overweight or obese before pregnancy. A significant association was found between maternal BMI and child's weight for height z-score (WHZ) and body mass index for age z-score (BAZ). Having high pre-pregnancy BMI may increase BMI and WAZ of offspring in early life. Findings from this study emphasise the importance of monitoring maternal weight status, particularly before and during pregnancy and early life of offspring among Malaysians. Copyright © 2015 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

  19. Segmentation and Estimation of the Histological Composition of the Tumor Mass in Computed Tomographic Images of Neuroblastoma

    National Research Council Canada - National Science Library

    Ayres, Fabio

    2001-01-01

    The problem that we investigate in the present paper Is the improvement of the analysis of the primary tumor mass, in patients with advanced neuroblastoma, using X-ray computed tomography (CT) exams...

  20. Spark ignition engine control: estimation and prediction of the in-cylinder mass and chemical species; Controle moteur a allumage commande: estimation / prediction de la masse et de la composition du melange enferme dans le cylindre

    Energy Technology Data Exchange (ETDEWEB)

    Giansetti, P.

    2005-09-15

    Spark ignition engine control has become a major issue regarding compliance with emissions legislation while ensuring driving comfort. The objective of this thesis was to estimate the mass and composition of gases inside the cylinder of an engine based on physics in order to insure better control of transient phases taking into account residual gases as well as exhaust gas recirculation. Residual gas fraction has been characterized using two experiments and one CFD code. A model has been validated experimentally and integrated into an observer which predicts pressure and temperature inside the manifold. The predictions of the different gas flows and the chemical species inside the cylinder are deduced. A closed loop observer has been validated experimentally and in simulation. Moreover, an algorithm estimating the fresh and burned gas mass from the cylinder pressure has been proposed in order to obtain the information cycle by cycle and cylinder by cylinder. (author)

  1. Determination of boron content and isotopic composition in gypsum by inductively coupled plasma optical emission spectroscopy and positive thermal ionization mass spectrometry using phase transformation.

    Science.gov (United States)

    Ma, Yun-Qi; Peng, Zhang-Kuang; Yang, Jian; Xiao, Ying-Kai; Zhang, Yan-Ling

    2017-12-01

    As a stable isotope, boron plays an important role in hydrogeology, environmental geochemistry, ore deposit geochemistry and marine paleoclimatology. However, there is no report of boron isotopic composition in gypsum. This is mainly confined to complete dissolution of Gypsum by water or acid. In this study, gypsum was converted to calcium carbonate (CaCO 3 ) with ammonium bicarbonate(NH 4 HCO 3 ) by two steps at 50°C. In every step, the mass ratio of NH 4 HCO 3 /CaSO 4 ·2H 2 O was twice, and conversion rate reached more than 98%. Converted CaCO 3 was totally dissolved with hydrochloric acid (the dissolution rate was over 99%). In order to overcome the difficulties of the matrix interference and the detection limit of Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), we use Amberlite IRA 743 resin to purify and enrichment the boron at first, then eluting boron from the resin with 10mL 0.1mol/L hydrochloric acid at 75°C. The boron isotopic composition of natural gypsum samples was determined using positive thermal ionization mass spectrometry (P-TIMS). The boron isotopic composition of gypsum may be an excellent indicator for the formation environment. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Standard test methods for chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade aluminum oxide and aluminum oxide-boron carbide composite pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1994-01-01

    1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade aluminum oxide and aluminum oxide-boron carbide composite pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Boron by Titrimetry 7 to 13 Separation of Boron for Mass Spectrometry 14 to 19 Isotopic Composition by Mass Spectrometry 20 to 23 Separation of Halides by Pyrohydrolysis 24 to 27 Fluoride by Ion-Selective Electrode 28 to 30 Chloride, Bromide, and Iodide by Amperometric Microtitrimetry 31 to 33 Trace Elements by Emission Spectroscopy 34 to 46 1.3 The values stated in SI units are to be regarded as the standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (F...

  3. [Accuracy, precision and speed of parenteral nutrition admixture bags manufacturing: comparison between automated and manual methods].

    Science.gov (United States)

    Zegbeh, H; Pirot, F; Quessada, T; Durand, T; Vételé, F; Rose, A; Bréant, V; Aulagner, G

    2011-01-01

    The parenteral nutrition admixture (PNA) manufacturing in hospital pharmacy is realized by aseptic transfer (AT) or sterilizing filtration (SF). The development of filling systems for PNA manufacturing requires, without standard, an evaluation comparing to traditional methods of SF. The filling accuracy of automated AT and SF was evaluated by mass and physical-chemistry tests in repeatability conditions (identical composition of PNA; n=five bags) and reproducibility conditions (different composition of PNA; n=57 bags). For each manufacturing method, the filling precision and the average time for PNA bags manufacturing were evaluated starting from an identical composition and volume PNA (n=five trials). Both manufacturing methods did not show significant difference of accuracy. Precision of both methods was lower than limits generally admitted for acceptability of mass and physical-chemistry tests. However, the manufacturing time for SF was superior (five different binary admixtures in five bags) or inferior (one identical binary admixture in five bags) to time recorded for automated AT. We show that serial manufacturing of PNA bags by SF with identical composition is faster than automated AT. Nevertheless, automated AT is faster than SF in variable composition of PNA. The manufacturing method choice will be motivate by the nature (i. e., variable composition or not) of the manufactured bags. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  4. Body composition and bone mineral mass in normal and obese female population using dual X-ray absorptiometry

    International Nuclear Information System (INIS)

    Massardo, T.; Gonzalez, P.; Coll, C.; Rodriguez, J.L.; Solis, I.; Oviedo, S.

    2002-01-01

    It has been observed that a greater percentage of body fat is associated with augmented bone mineral mass. Objective: The goal of this work was to assess the relationship between bone mineral density (BMD in g/cm 2 ) and content (BMC in g) and soft tissue components, fat and lean mass (in g) in whole body of adult female population in Chile. Method: We studied 185 volunteers, asymptomatic, excluding those using estrogens, regular medication, tobacco (>10 cigarettes/day), excessive alcohol intake or with prior oophorectomy. They were separated in 111 pre and 74 post menopausal and according to body mass index (BMI) they were 37 women > 30 kg/m 2 and 148 2 . A Lunar Dual X-Ray absorptiometer was used to determine whole BMD and BMC. Results: Post menopausal women were older and smaller [p:0.0001], with higher body mass index [p:0.0007] and with lower BMD and BMC and higher fat mass than the pre menopausal group; In the whole group, women with BMI ≥ 30 (obese) were compared with normal weight observing no difference in BMD. The fat mass incremented significantly with age. Obese women > 50 years presented greater BMC than the non-obese. The percentage of fat corresponded to 48% in the obese group and to 39% in the non-obese [p<0.0001]. Conclusion: Fat mass somehow protect bone mineral loss in older normal population, probably associated to multifactorial causes including extra ovaric estrogen production. Postmenopausal women presented lower mineral content than premenopausal, as it was expected

  5. Quantitative measurement of the chemical composition of geological standards with a miniature laser ablation/ionization mass spectrometer designed for in situ application in space research

    International Nuclear Information System (INIS)

    Neuland, M B; Riedo, A; Tulej, M; Wurz, P; Grimaudo, V; Moreno-García, P; Mezger, K

    2016-01-01

    A key interest of planetary space missions is the quantitative determination of the chemical composition of the planetary surface material. The chemical composition of surface material (minerals, rocks, soils) yields fundamental information that can be used to answer key scientific questions about the formation and evolution of the planetary body in particular and the Solar System in general. We present a miniature time-of-flight type laser ablation/ionization mass spectrometer (LMS) and demonstrate its capability in measuring the elemental and mineralogical composition of planetary surface samples quantitatively by using a femtosecond laser for ablation/ionization. The small size and weight of the LMS make it a remarkable tool for in situ chemical composition measurements in space research, convenient for operation on a lander or rover exploring a planetary surface. In the laboratory, we measured the chemical composition of four geological standard reference samples USGS AGV-2 Andesite, USGS SCo-l Cody Shale, NIST 97b Flint Clay and USGS QLO-1 Quartz Latite with LMS. These standard samples are used to determine the sensitivity factors of the instrument. One important result is that all sensitivity factors are close to 1. Additionally, it is observed that the sensitivity factor of an element depends on its electron configuration, hence on the electron work function and the elemental group in agreement with existing theory. Furthermore, the conformity of the sensitivity factors is supported by mineralogical analyses of the USGS SCo-l and the NIST 97b samples. With the four different reference samples, the consistency of the calibration factors can be demonstrated, which constitutes the fundamental basis for a standard-less measurement-technique for in situ quantitative chemical composition measurements on planetary surface. (paper)

  6. Measurement of isotopic composition of lanthanides in reprocessing process solutions by high-performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC/ICP-MS)

    International Nuclear Information System (INIS)

    Okano, Masanori; Jitsukata, Shu; Kuno, Takehiko; Yamada, Keiji

    2011-01-01

    Isotopic compositions of fission products in process solutions and wastes in a reprocessing plant are valuable to proceed safety study of the solutions and research/development concerning treatment/disposal of the wastes. The amount of neodymium-148 is a reliable indication to evaluate irradiation history. The isotopic compositions of samarium and gadolinium in high radioactive wastes are referred to as essential data to evaluate environmental impact in geological repositories. However, pretreatment of analysis must be done with complicated chemical separation such as solvent extraction and ion exchange. The actual measurement data of isotopic compositions of lanthanides comparable to the one of actinides in spent fuel reprocessing process has not been obtained enough. Rapid and high sensitive analytical technique based on high-performance liquid chromatography (HPLC) with an inductively coupled plasma mass spectrometry (ICP-MS) has been developed for the measurement of isotopic compositions of lanthanides in spent fuel reprocessing solutions. HPLC/ICP-MS measurement system was customized for a glove-box to be applied to the radioactive solutions. The cation exchange chromatographic columns (Shim-pack IC-C1) and injection valve (20μL) were located inside of the glove-box except the chromatographic pump. The elements of lanthanide group were separated by a gradient program of HPLC with α-hydroxyisobutyric acid. Isotopic compositions of lanthanides in eluate was sequentially analyzed by a quadruple ICP-MS. Optimization of parameter of HPLC and ICP-MS measurement system was examined with standard solutions containing 14 lanthanide elements. The elements of lanthanides were separated by HPLC and detected by ICP-MS within 25 minutes. The detection limits of Nd-146, Sm-147 and Gd-157 were 0.37 μg L -1 , 0.69 μg L -1 and 0.47 μg L -1 , respectively. The analytical precision of the above three isotopes was better than 10% for standard solutions of 100 μg L -1 with

  7. Properties of evolved mass-losing stars in the Milky Way and variations in the interstellar dust composition

    International Nuclear Information System (INIS)

    Thronson, H.A. Jr.; Latter, W.B.; Black, J.H.; Bally, J.; Hacking, P.; Steward Observatory, Tucson, AZ; AT and T Bell Laboratories, Holmdel, NJ; Cornell Univ., Ithaca, NY; California Institute of Technology, Pasadena)

    1987-01-01

    A large sample of evolved carbon-rich and oxygen-rich objects has been studied using data from the IRAS Point Source Catalog. The number density of infrared-emitting carbon stars shows no variation with Galactocentric radius, while the evolved oxygen star volume density can be well fitted by a given law. A law is given for the number of carbon stars; a total is found in the Galaxy of 48,000 highly evolved oxygen stars. The mass-return rate for all evolved stars is found to be 0.35 solar mass/yr, with a small percentage contribution from carbon stars. The mass-loss rates for both types of stars are dominated by the small number of objects with the smallest rates. A mean lifetime of about 200,000 yr is obtained for both carbon and oxygen stars. Main-sequence stars in the mass range of three to five solar masses are the probable precursors of the carbon stars. 53 references

  8. Determination of the compositions of the DIGM zone in nanocrystalline Ag/Au and Ag/Pd thin films by secondary neutral mass spectrometry

    Directory of Open Access Journals (Sweden)

    Gábor Y. Molnár

    2016-03-01

    Full Text Available Alloying by grain boundary diffusion-induced grain boundary migration is investigated by secondary neutral mass spectrometry depth profiling in Ag/Au and Ag/Pd nanocrystalline thin film systems. It is shown that the compositions in zones left behind the moving boundaries can be determined by this technique if the process takes place at low temperatures where solely the grain boundary transport is the contributing mechanism and the gain size is less than the half of the grain boundary migration distance. The results in Ag/Au system are in good accordance with the predictions given by the step mechanism of grain boundary migration, i.e., the saturation compositions are higher in the slower component (i.e., in Au or Pd. It is shown that the homogenization process stops after reaching the saturation values and further intermixing can take place only if fresh samples with initial compositions, according to the saturation values, are produced and heat treated at the same temperature. The reversal of the film sequence resulted in the reversal of the inequality of the compositions in the alloyed zones, which is in contrast to the above theoretical model, and explained by possible effects of the stress gradients developed by the diffusion processes itself.

  9. Simultaneous determination of components released from dental composite resins in human saliva by liquid chromatography/multiple-stage ion trap mass spectrometry.

    Science.gov (United States)

    Hsu, Wei-Yi; Wang, Ven-Shing; Lai, Chien-Chen; Tsai, Fuu-Jen

    2012-02-01

    Dental composite resins are widely used for fixing teeth; however, the monomers used in dental composite resins have been found to be cytotoxic and genotoxic, namely triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), and bisphenol A glycol dimethacrylate (Bis-GMA). In this study, we incubated dental composite resins with human saliva for demonstrating the released monomers and biodegradation products. A simple saliva sample dilution method without purification or derivatization was used for quantification. We found that liquid chromatography coupled with multiple-stage ion trap mass spectrometry (LC-MS(n) ) operated in selected reaction monitoring (SRM) mode was able to separate the three monomers within 10 min. The calibration curves were linear (R² >0.996) over a wide range for each monomer in saliva: TEGDMA, 5-500 ppb; UDMA, 5-100 ppb, and Bis-GMA, 5-700 ppb. Furthermore, several biodegradation products were discovered with data-dependent MS/MS scan techniques. Although TEGMA degradation products have previously been reported, we identified two previously unknown UDMA degradation products. The LC-MS/MS method developed in this study was able to successfully quantify monomers and their principal biodegradation products from dental composite resins in human saliva. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Grouping of Petroleum Substances as Example UVCBs by Ion Mobility-Mass Spectrometry to Enable Chemical Composition-Based Read-Across.

    Science.gov (United States)

    Grimm, Fabian A; Russell, William K; Luo, Yu-Syuan; Iwata, Yasuhiro; Chiu, Weihsueh A; Roy, Tim; Boogaard, Peter J; Ketelslegers, Hans B; Rusyn, Ivan

    2017-06-20

    Substances of Unknown or Variable composition, Complex reaction products, and Biological materials (UVCBs), including many refined petroleum products, present a major challenge in regulatory submissions under the EU Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) and US High Production Volume regulatory regimes. The inherent complexity of these substances, as well as variability in composition obfuscates detailed chemical characterization of each individual substance and their grouping for human and environmental health evaluation through read-across. In this study, we applied ion mobility mass spectrometry in conjunction with cheminformatics-based data integration and visualization to derive substance-specific signatures based on the distribution and abundance of various heteroatom classes. We used petroleum substances from four petroleum substance manufacturing streams and evaluated their chemical composition similarity based on high-dimensional substance-specific quantitative parameters including m/z distribution, drift time, carbon number range, and associated double bond equivalents and hydrogen-to-carbon ratios. Data integration and visualization revealed group-specific similarities for petroleum substances. Observed differences within a product group were indicative of batch- or manufacturer-dependent variation. We demonstrate how high-resolution analytical chemistry approaches can be used effectively to support categorization of UVCBs based on their heteroatom composition and how such data can be used in regulatory decision-making.

  11. Particle spectra and mass composition in the ultra-high energy region in the framework of the Galactic origin of cosmic rays

    Directory of Open Access Journals (Sweden)

    Lagutin A.A.

    2017-01-01

    Full Text Available The possibility for a self-consistent description of all the basic features of the observed cosmic ray spectra and primary composition variations in the energy range of 1015 ÷ 1020 eV within the Galactic origin scenario is examined. We assume the existence of Galactic sources that accelerate particles up to ∼ 3 · 1018Z eV and take into account a highly inhomogeneous (fractal-like distribution of matter and magnetic fields in the Galaxy that leads to extremely large free paths of particles (“Lévy flights”, along with an overwhelming contribution to the cosmic ray fluxes observed above ∼1018 eV from particles reaching the Solar System without scattering. Our scenario was refined on the basis of recent experimental results on primary mass composition. Model predictions, which could be verified with the improved high-precision measurements in the nearest future are discussed.

  12. Outdoor and Indoor Aerosol Size, Number, Mass and Compositional Dynamics at an Urban Background Site during Warm Season.

    Czech Academy of Sciences Publication Activity Database

    Talbot, Nicholas; Kubelová, Lucie; Makeš, Otakar; Cusack, Michael; Ondráček, Jakub; Vodička, Petr; Schwarz, Jaroslav; Ždímal, Vladimír

    2016-01-01

    Roč. 131, APR 2016 (2016), s. 171-184 ISSN 1352-2310 EU Projects: European Commission(XE) 315760 - HEXACOMM Institutional support: RVO:67985858 Keywords : aerosol * composition * dissociation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.629, year: 2016

  13. The influence of litter composition across the litter–soil interface on mass loss, nitrogen dynamics and the decomposer community

    Science.gov (United States)

    Many studies have investigated the influence of plant litter species composition on decomposition, but results have been context-dependent. Litter and soil are considered to constitute a decomposition continuum, but whether litter and soil ecosystems respond to litter identity an...

  14. A comparison between composition and density of the fat-free mass of young adult Singaporean Chinese and Dutch Caucasians

    NARCIS (Netherlands)

    Werkman, A.; Deurenberg-Yap, M.; Schmidt, G.; Deurenberg, P.

    2000-01-01

    The body composition was measured in 30 female Singapore Chinese and 34 female Dutch Caucasians aged (mean ± SD) 22.7 ± 3.6 years and in 39 male Singapore Chinese and 39 male Dutch Caucasians aged 23.3 ± 3.2 years. Methods: The body fat percentage (BF€was measured using densitometry and deuterium

  15. Dijet Mass Spectrum and a Search for Quark Compositeness in pp Collisions at √ (s) =1.8 TeV

    International Nuclear Information System (INIS)

    Grinstein, S.; Mostafa, M.; Piegaia, R.; Alves, G.A.; Carvalho, W.; Maciel, A.K.; Motta, H. da; Oliveira, E.; Santoro, A.; Oguri, V.; Gomez, B.; Hoeneisen, B.; Mooney, P.; Negret, J.P.; Ducros, Y.; Beri, S.B.; Bhatnagar, V.; Kohli, J.M.; Singh, J.B.; Shivpuri, R.K.; Acharya, B.S.; Banerjee, S.; Dugad, S.R.; Gupta, A.; Krishnaswamy, M.R.; Mondal, N.K.; Narasimham, V.S.; Parua, N.; Shankar, H.C.; Park, Y.M.; Choi, S.; Kim, S.K.; Castilla-Valdez, H.; Gonzalez Solis, J.L.; Hernandez-Montoya, R.; Magana-Mendoza, L.; Sanchez-Hernandez, A.; Pawlik, B.; Gavrilov, V.; Gershtein, Y.; Kuleshov, S.; Belyaev, A.; Dudko, L.V.; Ermolov, P.; Karmanov, D.; Leflat, A.; Manankov, V.; Merkin, M.; Shabalina, E.; Abramov, V.; Babintsev, V.V.; Bezzubov, V.A.; Bojko, N.I.; Burtovoi, V.S.; Chekulaev, S.V.; Denisov, S.P.; Dyshkant, A.; Eroshin, O.V.; Evdokimov, V.N.; Galyaev, A.N.; Goncharov, P.I.; Gurzhiev, S.N.; Kostritskiy, A.V.; Kozelov, A.V.; Kozlovsky, E.A.; Mayorov, A.A.; Babukhadia, L.; Davis, K.; Fein, D.; Forden, G.E.; Guida, J.A.; James, E.; Johns, K.; Nang, F.; Narayanan, A.; Rutherfoord, J.; Shupe, M.; Aihara, H.; Barberis, E.; Chen, L.

    1999-01-01

    Using the D0 detector at the 1.8 TeVp p Fermilab Tevatron collider, we have measured the inclusive dijet mass spectrum in the central pseudorapidity region | η jet | 2 . We have also measured the ratio of spectra σ (| η jet | jet | 3 s quantum chromodynamics predictions are in good agreement with the data and we rule out models of quark compositeness with a contact interaction scale < 2.4 TeV at the 95% confidence level. copyright 1999 The American Physical Society

  16. The influence of zirconia precursor/binding polymer mass ratio in the intermediate electrospun composite fibers on the phase transformation of final zirconia nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Rodaev, Vyacheslav V.; Zhigachev, Andrey O.; Korenkov, Viktor V.; Golovin, Yuri I. [Institute for Nanotechnology and Nanomaterials, Tambov State University, Internatsionalnaya Str. 33, 392000, Tambov (Russian Federation)

    2016-09-15

    Nanofibrous zirconia was fabricated by calcination of electrospun zirconium oxychloride/polyethylene oxide (PEO) composite fibers with different mass fraction of the components. ZrO{sub 2} nanofibers were characterized by scanning electron microscopy (SEM), nitrogen adsorption at 77 K, and X-ray diffractometry (XRD). It was revealed that increase in ZrOCl{sub 2}/PEO mass ratio above the threshold value significantly decreases tetragonal phase (t-ZrO{sub 2}) content and increases monoclinic phase (m-ZrO{sub 2}) content in final ceramic nanofibers. Distinct t-ZrO{sub 2} → m-ZrO{sub 2} transformation takes place when average ZrO{sub 2} grain size approaches to 30 nm. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. The dimensional accuracy of the sintered billets

    Directory of Open Access Journals (Sweden)

    Чингиз Ариф оглы Алиев

    2016-01-01

    Full Text Available The article presents the results of assessing the impact of the behaviour stability of the components included in the compositions and process parameters of their production, on the dimensional accuracy of workpieces. It was found that by increasing the amount of oxide in the composition is greater compaction of the sintered billet in the process of heat treatment. This also increases the density of all components of the composition

  18. Chemical composition of air masses transported from Asia to the U.S. West Coast during ITCT 2K2: Fossil fuel combustion versus biomass-burning signatures

    Science.gov (United States)

    de Gouw, J. A.; Cooper, O. R.; Warneke, C.; Hudson, P. K.; Fehsenfeld, F. C.; Holloway, J. S.; Hübler, G.; Nicks, D. K., Jr.; Nowak, J. B.; Parrish, D. D.; Ryerson, T. B.; Atlas, E. L.; Donnelly, S. G.; Schauffler, S. M.; Stroud, V.; Johnson, K.; Carmichael, G. R.; Streets, D. G.

    2004-12-01

    As part of the Intercontinental Transport and Chemical Transformation experiment in 2002 (ITCT 2K2), a National Oceanic and Atmospheric Administration (NOAA) WP-3D research aircraft was used to study the long-range transport of Asian air masses toward the west coast of North America. During research flights on 5 and 17 May, strong enhancements of carbon monoxide (CO) and other species were observed in air masses that had been transported from Asia. The hydrocarbon composition of the air masses indicated that the highest CO levels were related to fossil fuel use. During the flights on 5 and 17 May and other days, the levels of several biomass-burning indicators increased with altitude. This was true for acetonitrile (CH3CN), methyl chloride (CH3Cl), the ratio of acetylene (C2H2) to propane (C3H8), and, on May 5, the percentage of particles measured by the particle analysis by laser mass spectrometry (PALMS) instrument that were attributed to biomass burning based on their carbon and potassium content. An ensemble of back-trajectories, calculated from the U.S. west coast over a range of latitudes and altitudes for the entire ITCT 2K2 period, showed that air masses from Southeast Asia and China were generally observed at higher altitudes than air from Japan and Korea. Emission inventories estimate the contribution of biomass burning to the total emissions to be low for Japan and Korea, higher for China, and the highest for Southeast Asia. Combined with the origin of the air masses versus altitude, this qualitatively explains the increase with altitude, averaged over the whole ITCT 2K2 period, of the different biomass-burning indicators.

  19. The Effect of a 12-Week Omega-3 Supplementation on Body Composition, Muscle Strength and Physical Performance in Elderly Individuals with Decreased Muscle Mass

    Directory of Open Access Journals (Sweden)

    Roma Krzymińska-Siemaszko

    2015-08-01

    Full Text Available The aim of the study was to assess the effect of a polyunsaturated omega-3 fatty acids (PUFA supplementation on the parameters of body composition, muscle strength and physical performance in elderly people with decreased muscle mass (DMM. Fifty three elderly people with an ALM index (the ratio of appendicular lean mass to squared height either below (−2SD: low muscle mass-LMM or between (−1SD and −2SD: the risk of LMM-rLMM the ALM index for the young Polish reference population were randomly assigned to PUFA-treated groups (LMM-PUFA, rLMM-PUFA or control groups (LMM-control, rLMM-control. PUFA-treated groups received capsules containing 1.3 g of PUFA and 10 mg of vitamin E, while the control groups received 11 mg of vitamin E daily for 12 weeks. Body composition (BIA analysis, muscle strength (hand grip measured with dynamometer and physical performance (Timed Up and Go test-TUG were assessed before and after supplementation. No statistically significant differences were observed either in muscle mass or in the hand grip and TUG in any group. The post-pre difference (mean ± SD in ALM index was as follows (kg/m2: LMM-PUFA: 0.00 ± 0.30, rLMM-PUFA: 0.00 ± 0.22, LMM-control: 0.03 ± 0.36, rLMM-control: –0.03 ± 0.20. In our study, a 12 week supplementation of PUFA did not affect the evaluated parameters in elderly individuals with DMM.

  20. Discordance Between Body Mass Index (BMI) and a Novel Body Composition Change Index (BCCI) as Outcome Measures in Weight Change Interventions.

    Science.gov (United States)

    Nugent, Stephen D; Kaats, Gilbert R; Preuss, Harry G

    2018-01-01

    A general assumption is that the body mass index (BMI) reflects changes in fat mass (FM). However, it fails to distinguish the type of weight that is lost or gained-fat mass (FM) or fat-free mass (FFM). The BMI treats both changes the same although they have opposite health consequences. The objective of this study was to propose a more precise measure, a body composition change index (BCCI), which distinguishes between changes in FM and FFM, and this study compares it with using the BMI as an outcome measure. Data were obtained from 3,870 subjects who had completed dual-energy x-ray absorptiometry (DEXA) total body scans at baseline and end-of-study when participating in a variety of weight-loss interventions. Since height remained constant in this adult cohort, changes in the BMI corresponded with scale weight changes (r = 0.994), allowing BMI changes to be converted to "lbs." to match the statistic used for calculation of the BCCI. The BCCI is calculated by scoring increases in FFM (lbs.) and decreases in FM (lbs.) as positive outcomes and scoring decreases in FFM and increases in FM as negative outcomes. The BCCI is the net sum of these calculations. Differences between scale weight changes and BCCI values were subsequently compared to obtain "discordance scores." Discordance scores ranged from 0.0 lbs. to >30.0 lbs. with a mean absolute value of between the two measures of 7.79 lbs. (99% confidence interval: 7.49-8.10, p BCCI and the BMI to evaluate the efficacy of weight loss interventions. If assessing changes in body composition is a treatment goal, use of the BMI could result in significantly erroneous conclusions.

  1. Composition and mechanisms analysis of aromatic telechelic oligomers by mass spectroscopy; Analyse de la composition et de mecanismes de polymerisation d`oligomeres telecheliques aromatiques par spectrometrie de masse

    Energy Technology Data Exchange (ETDEWEB)

    Damerval, V.

    1997-10-22

    The aim of this work was to apply mass spectrometry, on the one hand to the characterization of telechelic oligo-imides with oxazoline and lactane end-caps and, on the other hand to the determination of the thermal reticulation mechanism of nadimides. First bis-oxazoline and buslactane end-capped, oligomers used to form blocks copolymers were studied by liquid secondary ion mass spectroscopy (LSIMS) and Matrix-assisted laser desorption ionization time of flight spectroscopy (MALDI-TOF). An acetamide end-cap by-product was detected. Then the analysis was modified to avoid the formation of this by-product which was unable to copolymerize. Secondly, to circumvent the experimental difficulties related to crosslinked networks, the study of the thermal polymerization of nadimides was performed ones (LSIMS, electroscopy, MALDI-TOF) led to the determination of the polynadimide structure. Thanks to MS/MS studies the nature of the linkages and the structure of the end-caps were established. Finally, this work evidenced the opportunity to use mass spectrometry to analyze synthetic polymers. (author) 222 refs.

  2. An Advanced Analytical Chemistry Experiment Using Gas Chromatography-Mass Spectrometry, MATLAB, and Chemometrics to Predict Biodiesel Blend Percent Composition

    Science.gov (United States)

    Pierce, Karisa M.; Schale, Stephen P.; Le, Trang M.; Larson, Joel C.

    2011-01-01

    We present a laboratory experiment for an advanced analytical chemistry course where we first focus on the chemometric technique partial least-squares (PLS) analysis applied to one-dimensional (1D) total-ion-current gas chromatography-mass spectrometry (GC-TIC) separations of biodiesel blends. Then, we focus on n-way PLS (n-PLS) applied to…

  3. Composition of hot ions /0.1-16 keV/e/ as observed by the GEOS and ISEE mass spectrometers and inferences for the origin and circulation of magnetospheric plasmas

    Science.gov (United States)

    Balsiger, H.

    1981-01-01

    The composition of hot magnetospheric plasma through different regions of the magnetosphere is described on the basis of mass spectrometer measurements by the GEOS 1, GEOS 2, and ISEE-1 spacecraft. Coordinated composition measurements on the different spacecraft also provide information on the spatial and temporal characteristics of the plasma during storms. Data on ion origins are also provided.

  4. Determination of hydrogen isotope composition in organic compounds

    International Nuclear Information System (INIS)

    Ordzhonikidze, K.G.; Parulava, L.P.; Vakhaniya, G.V.; Tarielashvili, V.O.

    1989-01-01

    method for determination of hydrogen isotope composition just in organic compounds using mass-spectrometer of the second class is suggested. The method enables to determine atomic fraction of hydrogen without multiplet separation. The accuracy of determination of deuterium atomic fraction in acetone in 1-99% range was equal to 3-0.2% respectively

  5. Exercise is More Effective at Altering Gut Microbial Composition and Producing Stable Changes in Lean Mass in Juvenile versus Adult Male F344 Rats.

    Directory of Open Access Journals (Sweden)

    Agnieszka Mika

    Full Text Available The mammalian intestine harbors a complex microbial ecosystem that influences many aspects of host physiology. Exposure to specific microbes early in development affects host metabolism, immune function, and behavior across the lifespan. Just as the physiology of the developing organism undergoes a period of plasticity, the developing microbial ecosystem is characterized by instability and may also be more sensitive to change. Early life thus presents a window of opportunity for manipulations that produce adaptive changes in microbial composition. Recent insights have revealed that increasing physical activity can increase the abundance of beneficial microbial species. We therefore investigated whether six weeks of wheel running initiated in the juvenile period (postnatal day 24 would produce more robust and stable changes in microbial communities versus exercise initiated in adulthood (postnatal day 70 in male F344 rats. 16S rRNA gene sequencing was used to characterize the microbial composition of juvenile versus adult runners and their sedentary counterparts across multiple time points during exercise and following exercise cessation. Alpha diversity measures revealed that the microbial communities of young runners were less even and diverse, a community structure that reflects volatility and malleability. Juvenile onset exercise altered several phyla and, notably, increased Bacteroidetes and decreased Firmicutes, a configuration associated with leanness. At the genus level of taxonomy, exercise altered more genera in juveniles than in the adults and produced patterns associated with adaptive metabolic consequences. Given the potential of these changes to contribute to a lean phenotype, we examined body composition in juvenile versus adult runners. Interestingly, exercise produced persistent increases in lean body mass in juvenile but not adult runners. Taken together, these results indicate that the impact of exercise on gut microbiota

  6. Seasonality of New Particle Formation in Vienna, Austria - Influence of Air Mass Origin and Aerosol Chemical Composition

    Czech Academy of Sciences Publication Activity Database

    Wonaschütz, A.; Demattio, A.; Wagner, R.; Burkart, J.; Zíková, Naděžda; Vodička, Petr; Ludwig, W.; Steiner, G.; Schwarz, Jaroslav; Hitzenberger, R.

    2015-01-01

    Roč. 118, OCT 2015 (2015), s. 118-126 ISSN 1352-2310 R&D Projects: GA MŠk 7AMB12AT021; GA ČR(CZ) GBP503/12/G147 Grant - others:FWF(AT) P19515-N20 Institutional support: RVO:67985858 Keywords : urban aerosol * aerosol chemical composition * new particle formation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.459, year: 2015

  7. Effect of seasonal differences in dietary meat intake on changes in body mass and composition in wild and captive brown bears

    Science.gov (United States)

    Hilderbrand, G.V.; Jenkins, S.G.; Schwartz, C.C.; Hanley, Thomas A.; Robbins, C.T.

    1999-01-01

    The influence of seasonal dietary meat intake on changes in body mass and composition in wild and captive brown bears (Ursus arctos) was investigated because the importance and availability of meat to brown bear populations is currently an important management consideration in several North American ecosystems. Adult female brown bears on the Kenai Peninsula, Alaska, utilized meat heavily in both spring and fall. Meat accounted for 76.2 ± 26.0% (mean ± 1 SD; primarily moose carrion and calves) of assimilated carbon and nitrogen in the spring and 80.4 ± 22.2% (primarily salmon) in the fall. Mass increases in the spring (71.8 ± 28.2%) were mostly lean body mass, but increases in the fall (81.0 ± 19.5%) were primarily fat. Daily intake by captive brown bears fed meat ad libitum during 12-day trials was positively related to body mass. Mass change was positively related to intake in both seasons, but the composition of the gain varied by season, with spring gains primarily lean body mass (64.2 ± 9.4%), while fall gains were 78.8 ± 19.6% lipid. Absolute rates of gain by wild bears occasionally equaled, but were usually much less than, those of captive bears. This was likely due to a combination of factors, which included the time required to locate and handle meat resources, the limited availability of or access to meat resources, and (or) the duration of meat resource availability. Estimated intake by bears not feeding selectively on high-energy components of moose and salmon were 8.5 ± 1.5 kg/day and 541 ± 156 kg/year and 10.8 ± 4.6 kg/day and 1003 ± 489 kg/year, respectively. Intake would drop by as much as 58% for bears feeding exclusively on salmon roe. Management strategies for areas with brown bears that consume significant amounts of meat should address the perpetuation and availability of these meat resources.

  8. Relationship between body composition, body mass index and bone mineral density in a large population of normal, osteopenic and osteoporotic women.

    Science.gov (United States)

    Andreoli, A; Bazzocchi, A; Celi, M; Lauro, D; Sorge, R; Tarantino, U; Guglielmi, G

    2011-10-01

    The knowledge of factors modulating the behaviour of bone mass is crucial for preventing and treating osteoporotic disease; among these factors, body weight (BW) has been shown to be of primary importance in postmenopausal women. Nevertheless, the relative effects of body composition indices are still being debated. Our aim was to analyze the relationship between body mass index (BMI), fat and lean mass and bone mineral density (BMD) in a large population of women. Moreover, this study represents a first important report on reference standard values for body composition in Italian women. Between 2005 and 2008, weight and height of 6,249 Italian women (aged 30-80 years) were measured and BMI was calculated; furthermore BMD, bone mineral content, fat and lean mass were measured by dual-energy X-ray absorptiometry. Individuals were divided into five groups by decades (group 1, 30.0-39.9; group 2, 40.0-49.9; group 3, 50.0-59.9; group 4, 60.0-69.9; group 5, 70.0-79.9). Differences among decades for all variables were calculated using a one-way analysis of variance (ANOVA) and Bonferroni test by the SPSS programme. Mean BW was 66.8±12.1 kg, mean height 159.1±6.3 cm and mean BMI 26.4±4.7 kg/m(2). According to BW and BMI, there was an increase of obesity with age, especially in women older than 50 years (posteoporosis in the examined population was 43.0% and 16.7%, respectively. Our data show that obesity significantly decreased the risk for osteoporosis but did not decrease the risk for osteopenia. It is strongly recommended that a strong policy regarding prevention of osteopenia and osteoporosis be commenced. An overall examination of our results suggests that both fat and lean body mass can influence bone mass and that their relative effect on bone could be modulated by their absolute amount and ratio to total BW.

  9. The Investigation of Isotopic Composition of Precipitation and water vapour by Using Air Mass Trajectories and Meteorological Parameters

    International Nuclear Information System (INIS)

    Dirican, A.; Acar, Y.; Demircan, M.

    2002-01-01

    In last century there are so many studies were carried out about stable isotopes of precipitation. The Researchers, study in this field directed to examine origin and transport of water vapour. To investigate the conditions of precipitation formation parallel with climatic changes, stable isotopes using as a powerful tool. So that a project coordinated by IAEA. In this presentation we will give some parts of this project which was carried out in Turkey. First results were obtained for 2001 year. The one of the first result which was obtained in this project is the relation between air temperature and isotopic composition of precipitation collected in Ankara Antalya and Adana station. Second was the observation of temporal variation of stable isotope composition in precipitation and water vapour in relation with water vapour transport. δD and δ 18 O content of atmospheric water vapour examined for January - December 2001 time interval. 27 precipitation event had been examined, starting from endengered place and following to trajectories until to reach Turkey, by using ground level and 500mbar synoptic charts. The observed δD and δ 18 O variations of water vapour is related with the endengered place (Atlantic Ocean, Mediterranean Sea, etc.) of water vapour. The isotopic composition of local precipitation forms by regional meteorological factors. In this study δD and δ 18 O relation of event, daily precipitation and water vapour were defined

  10. The Role of Muscle Mass, Muscle Quality, and Body Composition in Risk for the Metabolic Syndrome and Functional Decline in Older Adults: Topical Collection on Nutrition, Obesity, and Diabetes

    NARCIS (Netherlands)

    R.T. Mankowski (Robert T.); S.D. Anton (Stephen D.); M. Aubertin-Leheudre (Mylene)

    2015-01-01

    textabstractAbstract Age-related body composition changes include both loss of muscle mass (sarcopenia) and increase in fat mass, which jointly contribute to a decline in metabolic functions. Muscle quality is positively related to functional capacity and a lower risk for the development of the

  11. The Body Mass Index and Waist Circumference as Predictors of Body Composition in Post CSCI Wheelchair Rugby Players (Preliminary Investigations

    Directory of Open Access Journals (Sweden)

    Zwierzchowska Anna

    2014-12-01

    Full Text Available The enforced sedentary lifestyle and muscle paresis below the level of injury are associated with adipose tissue accumulation in the trunk. The value of anthropometric indicators of obesity in patients with spinal cord injuries has also been called into question. We hypothesized that the Body Mass Index recommended by the WHO to diagnose obesity in general population has too low sensitivity in case of wheelchair rugby players.

  12. Determination of peak bone mass density and composition in low-income urban residents of metro Manila using isotope techniques

    International Nuclear Information System (INIS)

    Lim-Abrahan, M.A.V.; Guanzon, L.V.V.; De Guzman, A.M.; Villaruel, C.M.; Santos, F.

    1996-01-01

    Filipinos are predisposed to osteoporosis because of inadequate calcium in their diet early on in life, confounded by malnutrition, susceptibility to infectious diseases and their generally small body frame. And yet the problem of osteoporosis has not been properly addressed. The incidence of osteoporosis is not known since oftentimes it is established only once complications have set in. It is believed that osteoporosis poses a public health concern but its extent is not realized at present because of lack of local epidemiological data. This study aims to determine the bone mass density as a function of age among 210 screened and healthy volunteers coming from urban poor communities of Metro Manila over a 3-year period. A LUNAR DPX-L bone densitometry for dual X-ray photon absorptiometry will be used, with measurements taken on the spine and femur. It also aims to correlate factors such as nutritional intake, physical activity, lifestyle, sex and body mass index with that of bone mass density. Blood and urine samples will be obtained for biochemistry and hormonal radioimmunoassay examination. Statistical analysis will be done to com are differences within the group and to determine rate of bone loss as a function of age and sex. Plans for future research include the determination of trace element content in cortical bone and tooth samples from healthy living subjects. (author)

  13. On the isolation of elemental carbon (EC) for micro-molar 14C accelerator mass spectrometry: development of a hybrid reference material for 14C-EC accuracy assurance, and a critical evaluation of the thermal optical kinetic (TOK) EC isolation procedure

    Science.gov (United States)

    Currie, L. A.; Kessler, J. D.

    2005-10-01

    The primary objective of the research reported here has been the development of a hybrid reference material (RM) to serve as a test of accuracy for elemental carbon (EC) isotopic (14C) speciation measurements. Such measurements are vital for the quantitative apportionment of fossil and biomass sources of "soot" (EC), the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement quality, carried out with NIST SRM 1649a (Urban Dust), showed a range of results, but since the "truth" was not known for this natural matrix RM, one had to rely on isotopic-chemical consistency evidence (14C in PAH, EC) of measurement validity (Currie et al., 2002). Components of the new Hybrid RM (DiesApple), however, have known 14C and EC composition, and they are nearly orthogonal (isotopically and chemically). NIST SRM 2975 (Forklift Diesel Soot) has little or no 14C, and its major compositional component is EC; SRM 1515 (Apple Leaves) has the 14C content of biomass-C, and it has little or no EC. Thus, the Hybrid RM can serve as an absolute isotopic test for the absence of EC-mimicking pyrolysis-C (char) from SRM 1515 in the EC isolate of the Hybrid RM, as well as a test for conservation of its dominant soot fraction throughout the isolation procedure. The secondary objective was to employ the Hybrid RM for the comparative evaluation of the thermal optical kinetic (TOK) and thermal optical transmission (TOT) methods for the isolation of EC for micro-molar carbon accelerator mass spectrometry (AMS). As part of this process, the relatively new TOK method was subjected to a critical evaluation and significant development. Key findings of our study are: (1) both methods exhibited biomass-C "leakage"; for TOT, the EC fraction isolated for AMS contained about 8% of the original biomass-C; for TOK, the refractory carbon (RC) isolated contained about 3% of the original biomass-C.; (2) the initial isothermal oxidation stage of

  14. On the isolation of elemental carbon (EC for micro-molar 14C accelerator mass spectrometry: development of a hybrid reference material for 14C-EC accuracy assurance, and a critical evaluation of the thermal optical kinetic (TOK EC isolation procedure

    Directory of Open Access Journals (Sweden)

    L. A. Currie

    2005-01-01

    Full Text Available The primary objective of the research reported here has been the development of a hybrid reference material (RM to serve as a test of accuracy for elemental carbon (EC isotopic (14C speciation measurements. Such measurements are vital for the quantitative apportionment of fossil and biomass sources of 'soot' (EC, the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement quality, carried out with NIST SRM 1649a (Urban Dust, showed a range of results, but since the 'truth' was not known for this natural matrix RM, one had to rely on isotopic-chemical consistency evidence (14C in PAH, EC of measurement validity (Currie et al., 2002. Components of the new Hybrid RM (DiesApple, however, have known 14C and EC composition, and they are nearly orthogonal (isotopically and chemically. NIST SRM 2975 (Forklift Diesel Soot has little or no 14C, and its major compositional component is EC; SRM 1515 (Apple Leaves has the 14C content of biomass-C, and it has little or no EC. Thus, the Hybrid RM can serve as an absolute isotopic test for the absence of EC-mimicking pyrolysis-C (char from SRM 1515 in the EC isolate of the Hybrid RM, as well as a test for conservation of its dominant soot fraction throughout the isolation procedure. The secondary objective was to employ the Hybrid RM for the comparative evaluation of the thermal optical kinetic (TOK and thermal optical transmission (TOT methods for the isolation of EC for micro-molar carbon accelerator mass spectrometry (AMS. As part of this process, the relatively new TOK method was subjected to a critical evaluation and significant development. Key findings of our study are: (1 both methods exhibited biomass-C 'leakage'; for TOT, the EC fraction isolated for AMS contained about 8% of the original biomass-C; for TOK, the refractory carbon (RC isolated contained about 3% of the original biomass-C.; (2 the initial isothermal oxidation stage

  15. Visualization of dynamic change in contraction-induced lipid composition in mouse skeletal muscle by matrix-assisted laser desorption/ionization imaging mass spectrometry.

    Science.gov (United States)

    Goto-Inoue, Naoko; Manabe, Yasuko; Miyatake, Shouta; Ogino, Shinya; Morishita, Ai; Hayasaka, Takahiro; Masaki, Noritaka; Setou, Mitsutoshi; Fujii, Nobuharu L

    2012-06-01

    Lipids in skeletal muscle play a fundamental role both in normal muscle metabolism and in disease states. Skeletal muscle lipid accumulation is associated with several chronic metabolic disorders, including obesity, insulin resistance, and type 2 diabetes. However, it is poorly understood whether the lipid composition of skeletal muscle changes by contraction, due to the complexity of lipid molecular species. In this study, we used matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) to investigate changes in skeletal muscle lipid composition induced by contraction. We successfully observed the reduction of diacylglycerol and triacylglycerol, which are generally associated with muscle contraction. Interestingly, we found the accumulation of some saturated and mono-unsaturated fatty acids and poly-unsaturated fatty acids containing phosphatidylcholine in contracted muscles. Moreover, the distributions of several types of lipid were changed by contraction. Our results show that changes in the lipid amount, lipid composition, and energy metabolic activity can be evaluated in each local spot of cells and tissues at the same time using MALDI-IMS. In conclusion, MALDI-IMS is a powerful tool for studying lipid changes associated with contractions.

  16. Methods of gas purification and effect on the ion composition in an RF atmospheric pressure plasma jet investigated by mass spectrometry

    International Nuclear Information System (INIS)

    Grosse-Kreul, Simon; Huebner, Simon; Schneider, Simon; Keudell, Achim von; Benedikt, Jan

    2016-01-01

    The analysis of the ion chemistry of atmospheric pressure plasmas is essential to evaluate ionic reaction pathways during plasma-surface or plasma-analyte interactions. In this contribution, the ion chemistry of a radio-frequency atmospheric pressure plasma jet (μ-APPJ) operated in helium is investigated by mass spectrometry (MS). It is found, that the ion composition is extremely sensitive to impurities such as N 2 , O 2 and H 2 O. Without gas purification, protonated water cluster ions of the form H + (H 2 O) n are dominating downstream the positive ion mass spectrum. However, even after careful feed gas purification to the sub-ppm level using a molecular sieve trap and a liquid nitrogen trap as well as operation of the plasma in a controlled atmosphere, the positive ion mass spectrum is strongly influenced by residual trace gases. The observations support the idea that species with a low ionization energy serve as a major source of electrons in atmospheric pressure helium plasmas. Similarly, the neutral density of atomic nitrogen measured by MS in a He/N 2 mixture is varying up to a factor 3, demonstrating the significant influence of impurities on the neutral species chemistry as well. (orig.)

  17. Standard test method for determination of uranium or plutonium isotopic composition or concentration by the total evaporation method using a thermal ionization mass spectrometer

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This method describes the determination of the isotopic composition and/or the concentration of uranium and plutonium as nitrate solutions by the thermal ionization mass spectrometric (TIMS) total evaporation method. Purified uranium or plutonium nitrate solutions are loaded onto a degassed metal filament and placed in the mass spectrometer. Under computer control, ion currents are generated by heating of the filament(s). The ion beams are continually measured until the sample is exhausted. The measured ion currents are integrated over the course of the run, and normalized to a reference isotope ion current to yield isotopic ratios. 1.2 In principle, the total evaporation method should yield isotopic ratios that do not require mass bias correction. In practice, some samples may require this bias correction. When compared to the conventional TIMS method, the total evaporation method is approximately two times faster, improves precision from two to four fold, and utilizes smaller sample sizes. 1.3 The tot...

  18. Body mass composition of ballet dancers and elite female aesthetic sport athletes from Cuba. DOI: 10.5007/1980-0037.2011v13n5p335

    Directory of Open Access Journals (Sweden)

    Julieta Aréchiga Viramontes

    2011-08-01

    Full Text Available The level of scenic beauty of ballet dancer’s figure is signified for the reason of possessing morpho-functional characteristics valid only within the artistic cannon. The female ballet dancers and the sportswomen who practice esthetic sports do have in common the need of being slim and executing efficiently the complex movements of their technical activities. The objective of this paper is to compare the body composition of ballet female dancers with that of the artistic gymnastics (GAR, the rhythmic gymnastics (GRI and the synchronized swimming (NAS elite sportswomen. Thirty two female ballet dancers of the National Cuban Ballet School and sixty three elite sportswomen who practice aesthetic sports in Cuba have been studied for the purpose. An anthropometric protocol of sixteen measures has been applied to calculate the kinanthropometric indexes of the corporal mass composition’s component. The general percentage of the fat mass (PMG in the ballet dancers was found statistically different to the GAR and GRI groups, but this one was similar in comparison with NAS group. Mayor muscle mass general percentage (PMM was obtained in the GAR and GRI groups, in comparison with the dancers. The ballet group showed the minor differential PMM-PMG, and muscular percentage of the transverse areas of the segments of extremities than the elite athlete groups. The data classified the ballet group as the one of less potential efficiency of technical and transitive movement than the other ones.

  19. Methods of gas purification and effect on the ion composition in an RF atmospheric pressure plasma jet investigated by mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Grosse-Kreul, Simon; Huebner, Simon; Schneider, Simon; Keudell, Achim von; Benedikt, Jan [Ruhr-Universitaet Bochum, Institute for Experimental Physics II, Bochum (Germany)

    2016-12-15

    The analysis of the ion chemistry of atmospheric pressure plasmas is essential to evaluate ionic reaction pathways during plasma-surface or plasma-analyte interactions. In this contribution, the ion chemistry of a radio-frequency atmospheric pressure plasma jet (μ-APPJ) operated in helium is investigated by mass spectrometry (MS). It is found, that the ion composition is extremely sensitive to impurities such as N{sub 2}, O{sub 2} and H{sub 2}O. Without gas purification, protonated water cluster ions of the form H{sup +}(H{sub 2}O){sub n} are dominating downstream the positive ion mass spectrum. However, even after careful feed gas purification to the sub-ppm level using a molecular sieve trap and a liquid nitrogen trap as well as operation of the plasma in a controlled atmosphere, the positive ion mass spectrum is strongly influenced by residual trace gases. The observations support the idea that species with a low ionization energy serve as a major source of electrons in atmospheric pressure helium plasmas. Similarly, the neutral density of atomic nitrogen measured by MS in a He/N{sub 2} mixture is varying up to a factor 3, demonstrating the significant influence of impurities on the neutral species chemistry as well. (orig.)

  20. Passive and active roles of fat-free mass in the control of energy intake and body composition regulation

    OpenAIRE

    Dulloo, Abdul G.; Jacquet, Jean; Miles-Chan, Jennifer L; Schutz, Yves

    2017-01-01

    While putative feedback signals arising from adipose tissue are commonly assumed to provide the molecular links between the body’s long-term energy requirements and energy intake, the available evidence suggests that the lean body or fat-free mass (FFM) also plays a role in the drive to eat. A distinction must, however, be made between a ‘passive’ role of FFM in driving energy intake, which is likely to be mediated by ‘energy-sensing’ mechanisms that translate FFM-induced energy requirem...

  1. Target Price Accuracy

    Directory of Open Access Journals (Sweden)

    Alexander G. Kerl

    2011-04-01

    Full Text Available This study analyzes the accuracy of forecasted target prices within analysts’ reports. We compute a measure for target price forecast accuracy that evaluates the ability of analysts to exactly forecast the ex-ante (unknown 12-month stock price. Furthermore, we determine factors that explain this accuracy. Target price accuracy is negatively related to analyst-specific optimism and stock-specific risk (measured by volatility and price-to-book ratio. However, target price accuracy is positively related to the level of detail of each report, company size and the reputation of the investment bank. The potential conflicts of interests between an analyst and a covered company do not bias forecast accuracy.

  2. The effects of a high dosage of creatine and caffeine supplementation on the lean body mass composition of rats submitted to vertical jumping training

    Directory of Open Access Journals (Sweden)

    Carneiro-Junior Miguel A

    2011-03-01

    Full Text Available Abstract Background The influences of creatine and caffeine supplementation associated with power exercise on lean body mass (LBM composition are not clear. The purpose of this research was to determine whether supplementation with high doses of creatine and caffeine, either solely or combined, affects the LBM composition of rats submitted to vertical jumping training. Methods Male Wistar rats were randomly divided into 8 groups: Sedentary (S or Exercised (E [placebo (Pl, creatine (Cr, caffeine (Caf or creatine plus caffeine (CrCaf]. The supplemented groups received creatine [load: 0.430 g/kg of body weight (BW for 7 days; and maintenance: 0.143 g/kg of BW for 35 days], caffeine (15 mg/kg of BW for 42 days or creatine plus caffeine. The exercised groups underwent a vertical jump training regime (load: 20 - 50% of BW, 4 sets of 10 jumps interspersed with 1 min resting intervals, 5 days/wk, for 6 weeks. LBM composition was evaluated by portions of water, protein and fat in the rat carcass. Data were submitted to ANOVA followed by the Tukey post hoc test and Student's t test. Results Exercised animals presented a lower carcass weight (10.9%; P = 0.01, as compared to sedentary animals. However, no effect of supplementation was observed on carcass weight (P > 0.05. There were no significant differences among the groups (P > 0.05 for percentage of water in the carcass. The percentage of fat in the group SCr was higher than in the groups SCaf and ECr (P Conclusions High combined doses of creatine and caffeine does not affect the LBM composition of either sedentary or exercised rats, however, caffeine supplementation alone reduces the percentage of fat. Vertical jumping training increases the percentages of water and protein and reduces the fat percentage in rats.

  3. Mass spectrometrical study of rare gas compositions and neutron capture effects in Yamato-74191 (L 3) Chondrite

    International Nuclear Information System (INIS)

    Takaoka, N.; Nagao, K.

    1980-01-01

    The unequilibrated hypersthene chondrite Yamato-74191 was studied mass spectrometrically for rare gases released at various temperatures. Cosmogenic gases dominate in He and Ne. The meteorite contains large amounts of trapped Ar, Kr and Xe, and radiogenic 40 Ar and 129 Xe. Cosmic-ray irradiation and K-Ar ages were determined. In addition to spallogenic components of Kr and Xe, isotopic excesses of 8 sup(O)Kr, 82 Kr, 128 Xe and 126 Xe relative to AVCC-Kr and -Xe were found. The ratio of 80 Kr-excess to 82 Kr-excess is 2.66 after correction for spallogenic Kr. A correlation between 128 Xe/ 132 Xe and 129 Xe/ 132 Xe was found. The 129 Xe/ 132 Xe ratio for trapped Xe in Yamato-74191 was determined as 1.12 +- 0.29 with the correlation plot. The excesses found in Yamato-74191 are best explained by epithermal neutron capture on Br and I, and by the 127 I(n,2nβ) 126 Xe reaction. Using neutron-produced 80 Kr, the neutron slowing-down density was estimated to be 0.14 +- 0.03 cm -3 sec -1 . A minimum mass and a preatmospheric radius was estimated to be 470 kg and 32 cm, respectively. (orig.)

  4. Technical Report on the Development of Mutant Paracoccus strain and Optimization of Medium Composition for the Mass Production of Astaxanthin

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jong Il; Lee, Ju Woon; Kim, Jae Hun; Song, Beom Seok

    2010-08-15

    Astaxanthin is used to role of provitamin A, and it is stronger antioxidant activity than vitamin E (100-500 times higher activity) and other carotenoids (10-fold). Furthermore, astaxanthin is also used as a nutraceutical and a medicinal ingredient against degenerative diseases such as cancer, heart disease, and skin related illness. The objective of this study was develop a carotenoid-hyperproducing mutant of Paracoccus N81106 using gamma irradiation and optimized medium composition. A mutant of Paracoccus having higher carotenoid content was isolated, and the production medium was optimized using response surface methodology. These results support that astaxanthin with strong antioxidant activity could be economically produced using the mutant and will be helpful for the related industry

  5. Technical Report on the Development of Mutant Paracoccus strain and Optimization of Medium Composition for the Mass Production of Astaxanthin

    International Nuclear Information System (INIS)

    Choi, Jong Il; Lee, Ju Woon; Kim, Jae Hun; Song, Beom Seok

    2010-08-01

    Astaxanthin is used to role of provitamin A, and it is stronger antioxidant activity than vitamin E (100-500 times higher activity) and other carotenoids (10-fold). Furthermore, astaxanthin is also used as a nutraceutical and a medicinal ingredient against degenerative diseases such as cancer, heart disease, and skin related illness. The objective of this study was develop a carotenoid-hyperproducing mutant of Paracoccus N81106 using gamma irradiation and optimized medium composition. A mutant of Paracoccus having higher carotenoid content was isolated, and the production medium was optimized using response surface methodology. These results support that astaxanthin with strong antioxidant activity could be economically produced using the mutant and will be helpful for the related industry

  6. Solvent Composition-Dependent Signal-Reduction of Molecular Ions Generated from Aromatic Compounds in (+) Atmospheric Pressure Photo Ionization Mass Spectrometry.

    Science.gov (United States)

    Lee, Seulgidaun; Ahmed, Arif; Kim, Sunghwan

    2018-03-30

    The ionization process is essential for successful mass spectrometry (MS) analysis because of its influence on selectivity and sensitivity. In particular, certain solvents reduce the ionization of the analyte, thereby reducing the overall sensitivity in APPI. Since the sensitivity varies greatly depending on the solvents, a fundamental understanding of the mechanism is required. Standard solutions were analyzed by (+) Atmospheric pressure photo ionization (APPI) QExactive ion trap mass spectrometer (Thermo Scientific). Each solution was infused directly to the APPI source at a flow rate 100 μl/min and the APPI source temperature was 300 °C. Other operating mass spectrometric parameters were maintained under the same conditions. Quantum mechanical calculations were carried out using the Gaussian 09 suite program. Density functional theory was used to calculate the reaction enthalpies (∆H) of reaction between toluene and other solvents. The experimental and theoretical results showed good agreement. The abundances of analyte ions were well correlated with the calculated ∆H values. Therefore, the results strongly support the suggested signal reduction mechanism. In addition, linear correlations between the abundance of toluene and analyte molecular ions were observed, which also supports the suggested mechanism. A solvent composition-dependent signal reduction mechanism was suggested and evaluated for the (+) atmospheric pressure photo ionization (APPI) mass spectrometry analysis of poly-aromatic hydrocarbons (PAHs) generating mainly molecular ions. Overall, the evidence provided in this work suggests that reactions between solvent cluster(s) and toluene molecular ions are responsible for the observed signal reductions. This article is protected by copyright. All rights reserved.

  7. Hyphenating size‐exclusion chromatography with electrospray mass spectrometry; using on‐line liquid‐liquid extraction to study the lipid composition of lipoprotein particles

    Science.gov (United States)

    Osei, Michael; Griffin, Julian L.

    2015-01-01

    Rationale Lipoproteins belong to the most commonly measured clinical biochemical parameters. Lipidomics is an orthogonal approach and aims to profile the individual lipid molecules that jointly form the lipoprotein particles. However, in the first step of the extraction of lipid molecules from serum, an organic solvent is used leading to dissociation of the lipoproteins. Thus far it has been impossible to combine lipidomics and lipoprotein analysis in one analytical system. Methods Human plasma was diluted in phosphate‐buffered saline (PBS) and injected onto a Superose 6 PC 3.2 column with PBS as a mobile phase to separate lipoproteins. The eluent was led to a Syrris FLLEX module, which also received CHCl3/MeOH (3:1). The two phases were mixed and subsequently separated using a Teflon membrane in an especially designed pressurized flow chamber. The organic phase was led to a standard electrospray source of an Orbitrap mass spectrometer. Results Size‐exclusion chromatography (SEC) has been commonly applied to separate lipoproteins and is considered a practical alternative to ultracentrifugation. Through the on‐line liquid‐liquid extraction method it becomes possible to obtained detailed mass spectra of lipids across different lipoprotein fractions. The extracted ion chromatograms of specific lipid signals showed their distribution against the size of lipoprotein particles. Conclusions The application of on‐line liquid‐liquid extraction allows for the continuous electrospray‐based mass spectral analysis of SEC eluent, providing the detailed lipid composition of lipoprotein particles separated by size. This approach provides new possibilities for the study of the biochemistry of lipoproteins. © 2015 The Authors. Rapid Communications in Mass Spectrometry Published by John Wiley & Sons Ltd. PMID:26443395

  8. Development of routines for simultaneous in situ chemical composition and stable Si isotope ratio analysis by femtosecond laser ablation inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Frick, Daniel A., E-mail: dfrick@gfz-potsdam.de [GFZ German Research Centre for Geosciences, 14473 Potsdam (Germany); Schuessler, Jan A. [GFZ German Research Centre for Geosciences, 14473 Potsdam (Germany); Blanckenburg, Friedhelm von [GFZ German Research Centre for Geosciences, 14473 Potsdam (Germany); Institute of Geological Science, Freie Universität Berlin, 12249 Berlin (Germany)

    2016-09-28

    Stable metal (e.g. Li, Mg, Ca, Fe, Cu, Zn, and Mo) and metalloid (B, Si, Ge) isotope ratio systems have emerged as geochemical tracers to fingerprint distinct physicochemical reactions. These systems are relevant to many Earth Science questions. The benefit of in situ microscale analysis using laser ablation (LA) over bulk sample analysis is to use the spatial context of different phases in the solid sample to disclose the processes that govern their chemical and isotopic compositions. However, there is a lack of in situ analytical routines to obtain a samples' stable isotope ratio together with its chemical composition. Here, we evaluate two novel analytical routines for the simultaneous determination of the chemical and Si stable isotope composition (δ{sup 30}Si) on the micrometre scale in geological samples. In both routines, multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) is combined with femtosecond-LA, where stable isotope ratios are corrected for mass bias using standard-sample-bracketing with matrix-independent calibration. The first method is based on laser ablation split stream (LASS), where the laser aerosol is split and introduced simultaneously into both the MC-ICP-MS and a quadrupole ICP-MS. The second method is based on optical emission spectroscopy using direct observation of the MC-ICP-MS plasma (LA-MC-ICP-MS|OES). Both methods are evaluated using international geological reference materials. Accurate and precise Si isotope ratios were obtained with an uncertainty typically better than 0.23‰, 2SD, δ{sup 30}Si. With both methods major element concentrations (e.g., Na, Al, Si, Mg, Ca) can be simultaneously determined. However, LASS-ICP-MS is superior over LA-MC-ICP-MS|OES, which is limited by its lower sensitivity. Moreover, LASS-ICP-MS offers trace element analysis down to the μg g{sup −1}-range for more than 28 elements due to lower limits of detection, and with typical uncertainties better than 15%. For in situ

  9. Development of routines for simultaneous in situ chemical composition and stable Si isotope ratio analysis by femtosecond laser ablation inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Frick, Daniel A.; Schuessler, Jan A.; Blanckenburg, Friedhelm von

    2016-01-01

    Stable metal (e.g. Li, Mg, Ca, Fe, Cu, Zn, and Mo) and metalloid (B, Si, Ge) isotope ratio systems have emerged as geochemical tracers to fingerprint distinct physicochemical reactions. These systems are relevant to many Earth Science questions. The benefit of in situ microscale analysis using laser ablation (LA) over bulk sample analysis is to use the spatial context of different phases in the solid sample to disclose the processes that govern their chemical and isotopic compositions. However, there is a lack of in situ analytical routines to obtain a samples' stable isotope ratio together with its chemical composition. Here, we evaluate two novel analytical routines for the simultaneous determination of the chemical and Si stable isotope composition (δ 30 Si) on the micrometre scale in geological samples. In both routines, multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) is combined with femtosecond-LA, where stable isotope ratios are corrected for mass bias using standard-sample-bracketing with matrix-independent calibration. The first method is based on laser ablation split stream (LASS), where the laser aerosol is split and introduced simultaneously into both the MC-ICP-MS and a quadrupole ICP-MS. The second method is based on optical emission spectroscopy using direct observation of the MC-ICP-MS plasma (LA-MC-ICP-MS|OES). Both methods are evaluated using international geological reference materials. Accurate and precise Si isotope ratios were obtained with an uncertainty typically better than 0.23‰, 2SD, δ 30 Si. With both methods major element concentrations (e.g., Na, Al, Si, Mg, Ca) can be simultaneously determined. However, LASS-ICP-MS is superior over LA-MC-ICP-MS|OES, which is limited by its lower sensitivity. Moreover, LASS-ICP-MS offers trace element analysis down to the μg g −1 -range for more than 28 elements due to lower limits of detection, and with typical uncertainties better than 15%. For in situ

  10. Environmental complexity of a port: Evidence from circulation of the water masses, and composition and contamination of bottom sediments.

    Science.gov (United States)

    Cutroneo, L; Carbone, C; Consani, S; Vagge, G; Canepa, G; Capello, M

    2017-06-15

    Ports are complex environments due to their complicated geometry (quays, channels, and piers), the presence of human activities (vessel traffic, shipyards, industries, and discharges), and natural factors (stream and torrent inputs, sea action, and currents). Taking these factors into consideration, we have examined the marine environment of a port from the point of view of the circulation of the water masses, hydrological characteristics, distribution of the sediment grain-size, mineralogical characteristics, and metal concentrations of the bottom sediments. Our results show that, in the case of the Port of Genoa (north-western Italy), the impact of human activities (such as a coal power-plant, oil depots, shipyards, dredging of the bottom sediments, etc.), natural processes (such as currents, fresh water and sediment inputs from the torrents), and the morphology of the basin, are important factors in the sediment, water, and metal distributions that have given rise to a complex environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Ecological Variation in Response to Mass-Flowering Oilseed Rape and Surrounding Landscape Composition by Members of a Cryptic Bumblebee Complex.

    Directory of Open Access Journals (Sweden)

    Dara A Stanley

    Full Text Available The Bombus sensu stricto species complex is a widespread group of cryptic bumblebee species which are important pollinators of many crops and wild plants. These cryptic species have, until now, largely been grouped together in ecological studies, and so little is known about their individual colony densities, foraging ranges or habitat requirements, which can be influenced by land use at a landscape scale. We used mass-flowering oilseed rape fields as locations to sample bees of this complex, as well as the second most common visitor to oilseed rape B. lapidarius, and molecular RFLP methods to distinguish between the cryptic species. We then used microsatellite genotyping to identify sisters and estimate colony densities, and related both proportions of cryptic species and their colony densities to the composition of the landscape surrounding the fields. We found B. lucorum was the most common member of the complex present in oilseed rape followed by B. terrestris. B. cryptarum was also present in all but one site, with higher proportions found in the east of the study area. High numbers of bumblebee colonies were estimated to be using oilseed rape fields as a forage resource, with B. terrestris colony numbers higher than previous estimates from non-mass-flowering fields. We also found that the cryptic species responded differently to surrounding landscape composition: both relative proportions of B. cryptarum in samples and colony densities of B. lucorum were negatively associated with the amount of arable land in the landscape, while proportions and colony densities of other species did not respond to landscape variables at the scale measured. This suggests that the cryptic species have different ecological requirements (which may be scale-dependent and that oilseed rape can be an important forage resource for many colonies of bumblebees. Given this, we recommend sustainable management of this crop to benefit bumblebees.

  12. Analysis of the monosaccharide composition of water-soluble polysaccharides from Sargassum fusiforme by high performance liquid chromatography/electrospray ionisation mass spectrometry.

    Science.gov (United States)

    Wu, Xiaodan; Jiang, Wei; Lu, Jiajia; Yu, Ying; Wu, Bin

    2014-02-15

    Sargassum fusiforme (hijiki) is the well-known edible algae, whose polysaccharides have been proved to possess interesting bioactivities like antitumor, antioxidant, antimicrobial and immunomodulatory activities. A facile and sensitive method based on high-performance liquid chromatography method of pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone (PMP) coupled with electrospray ionisation mass spectrometry (HPLC/ESI-MS) has been established for the analysis of the monosaccharide composition of polysaccharides in S. fusiforme. Monosaccharides have been converted into PMP-labelled derivatives with aqueous ammonia as a catalyst at 70 °C for 30 min. The optimisation of the pre-column derivatization process was studied. The LODs of the monosaccharides were in the range from 0.01 to 0.02 nmol. PMP-labelled mixture of monosaccharides has been well separated by a reverse-phase HPLC and detected by on-line ESI-MS method under optimised conditions. The mobile phase of elution system was chosen as acetonitrile (solvent A) and 20mM aqueous ammonium acetate (solvent B) (pH 3.0) with Zorbax XDB-C18 column at 30 °C for the separation of the monosaccharide derivatives. Identification of the monosaccharides composition was carried out by analysis with mass spectral behaviour and chromatography characteristics of 1-phenyl-3-methyl-5-pyrazolone (PMP) labelled monosaccharides. All PMP-labelled derivatives display high chemical stabilities, whose regular MS fragmentation is specific for reducing labelled sugars. The result showed that the S. fusiforme polysaccharide consisted of mannose, glucose, galactose, xylose, fucose and glucuronic acid or galacturonic acid, or both uronic acids. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Composition of Mediterranean fruit fly third instar larvae (Diptera: Tephritidae) and diet: Nutrient balance studies on amino acids, minerals and nutrient composition in fresh and spent mass rearing diets

    International Nuclear Information System (INIS)

    Chan, Harvey T. Jr.; Jang, Eric B.; Ako, Harry; Niino-Duponte, Ruth Y.; Carpenter, James R.

    2000-01-01

    Mass production of the Mediterranean fruit fly (Medfly) larvae, Ceratitis capitata Wiedemann, requires a rearing diet (Tanaka et al. 1969 1970) of which the nutrient requirements and digestibility have not been established. Setbacks in rearing productivity from the expected 100% yield to as low as 3% yield may occasionally be directly attributed to insecticide contamination or a variety of possible cause(s) (Kobayashi, 1993). These causes include inadequate nutrition, poor diet formulation, overcrowding of either microorganisms or Drosophila, or to the inherent processes of oxidative or microbial deterioration of nutrients. The purpose of this study was to establish the nutritional status of the Mediterranean fruit fly diet through a material balance study for changes in proximate composition (i.e., moisture, protein, fat, ash, carbohydrates), amino acids, minerals between fresh and spent diets, and in the fruit fly larvae themselves

  14. Food frequency questionnaire as an indicator of the serum composition of essential n-3 and n-6 polyunsaturated fatty acids in early pregnancy, according to body mass index.

    Science.gov (United States)

    Lepsch, J; Vaz, J S; Moreira, J D; Pinto, T J P; Soares-Mota, M; Kac, G

    2015-02-01

    We investigated whether food frequency questionnaire (FFQ) may be indicative of the serum composition of essential n-3 and n-6 polyunsaturated fatty acids (PUFAs) in early pregnancy and if correlations are affected by body mass index (BMI). The present study comprised a prospective cohort conducted in Rio de Janeiro, Brazil. The sample was composed of 248 women, aged 20-40 years, between 6 and the 13 weeks of gestation. Dietary intake was assessed using a validated FFQ. Fatty acid serum compositions were determined in fasting serum samples, employing a high-throughput robotic direct methylation coupled with fast gas-liquid chromatography. Spearman's correlation (r(s)) was used to assess the relationship between fatty acid intake and corresponding serum composition. Women were classified according to BMI (kg m(-2) ) as underweight/normal weight (BMI < 25 kg m(-2) ; n = 139) or excessive weight (BMI ≥ 25 kg m(-2) ; n = 109). In the total sample, dietary report was significantly correlated with the serum composition of total polyunsaturated fatty acid (PUFA; r(s) = 0.232, P < 0.001), linoleic acid (LA; 18:2n-6; r(s) = 0.271, P < 0.001), eicosapentaenoic acid (EPA; 20:5n-3; r(s) = 0.263, P < 0.001) and docosahexaenoic acid (DHA; 22:6n-3; r(s) = 0.209, P = 0.001). When analyses were stratified by BMI, significant correlations between FFQ and serum composition among underweight/normal weight women were observed for total PUFA (r(s) = 0.323, P < 0.001), LA (r(s) = 0.322, P < 0.001), EPA (r(s) = 0.352, P < 0.001) and DHA (r(s) = 0.176, P = 0.039). Among women of excessive weight, significant correlations were observed only for alpha linolenic acid (ALA; 18:3n-3; r(s) = 0.199, P = 0.040) and DHA (r(s) = 0.236, P = 0.014). FFQ in early pregnancy may be used as a possible indicator of serum concentrations of fatty acids. Higher correlations were observed among underweight/normal weight women. © 2014 The British Dietetic Association Ltd.

  15. Geotail observations of plasma sheet ion composition over 16 years: On variations of average plasma ion mass and O+ triggering substorm model

    Science.gov (United States)

    Nosé, M.; Ieda, A.; Christon, S. P.

    2009-07-01

    We examined long-term variations of ion composition in the plasma sheet, using energetic (9.4-212.1 keV/e) ion flux data obtained by the suprathermal ion composition spectrometer (STICS) sensor of the energetic particle and ion composition (EPIC) instrument on board the Geotail spacecraft. EPIC/STICS observations are available from 17 October 1992 for more than 16 years, covering the declining phase of solar cycle 22, all of solar cycle 23, and the early phase of solar cycle 24. This unprecedented long-term data set revealed that (1) the He+/H+ and O+/H+ flux ratios in the plasma sheet were dependent on the F10.7 index; (2) the F10.7 index dependence is stronger for O+/H+ than He+/H+; (3) the O+/H+ flux ratio is also weakly correlated with the ΣKp index; and (4) the He2+/H+ flux ratio in the plasma sheet appeared to show no long-term trend. From these results, we derived empirical equations related to plasma sheet ion composition and the F10.7 index and estimated that the average plasma ion mass changes from ˜1.1 amu during solar minimum to ˜2.8 amu during solar maximum. In such a case, the Alfvén velocity during solar maximum decreases to ˜60% of the solar minimum value. Thus, physical processes in the plasma sheet are considered to be much different between solar minimum and solar maximum. We also compared long-term variation of the plasma sheet ion composition with that of the substorm occurrence rate, which is evaluated by the number of Pi2 pulsations. No correlation or negative correlation was found between them. This result contradicts the O+ triggering substorm model, in which heavy ions in the plasma sheet increase the growth rate of the linear ion tearing mode and play an important role in localization and initiation of substorms. In contrast, O+ ions in the plasma sheet may prevent occurrence of substorms.

  16. Detailed Source-Specific Molecular Composition of Ambient Aerosol Organic Matter Using Ultrahigh Resolution Mass Spectrometry and 1H NMR

    Directory of Open Access Journals (Sweden)

    Amanda S. Willoughby

    2016-06-01

    Full Text Available Organic aerosols (OA are universally regarded as an important component of the atmosphere that have far-ranging impacts on climate forcing and human health. Many of these impacts are related to OA molecular characteristics. Despite the acknowledged importance, current uncertainties related to the source apportionment of molecular properties and environmental impacts make it difficult to confidently predict the net impacts of OA. Here we evaluate the specific molecular compounds as well as bulk structural properties of total suspended particulates in ambient OA collected from key emission sources (marine, biomass burning, and urban using ultrahigh resolution mass spectrometry (UHR-MS and proton nuclear magnetic resonance spectroscopy (1H NMR. UHR-MS and 1H NMR show that OA within each source is structurally diverse, and the molecular characteristics are described in detail. Principal component analysis (PCA revealed that (1 aromatic nitrogen species are distinguishing components for these biomass burning aerosols; (2 these urban aerosols are distinguished by having formulas with high O/C ratios and lesser aromatic and condensed aromatic formulas; and (3 these marine aerosols are distinguished by lipid-like compounds of likely marine biological origin. This study provides a unique qualitative approach for enhancing the chemical characterization of OA necessary for molecular source apportionment.

  17. Ganglioside Composition in Beef, Chicken, Pork, and Fish Determined Using Liquid Chromatography-High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Fong, Bertram Y; Ma, Lin; Khor, Geok Lin; van der Does, Yvonne; Rowan, Angela; McJarrow, Paul; MacGibbon, Alastair K H

    2016-08-17

    Gangliosides (GA) are found in animal tissues and fluids, such as blood and milk. These sialo-glycosphingolipids have bioactivities in neural development, the gastrointestinal tract, and the immune system. In this study, a high-performance liquid chromatography-mass spectrometry (HPLC-MS) method was validated to characterize and quantitate the GA in beef, chicken, pork, and fish species (turbot, snapper, king salmon, and island mackerel). For the first time, we report the concentration of GM3, the dominant GA in these foods, as ranging from 0.35 to 1.1 mg/100 g and 0.70 to 5.86 mg/100 g of meat and fish, respectively. The minor GAs measured were GD3, GD1a, GD1b, and GT1b. Molecular species distribution revealed that the GA contained long- to very-long-chain acyl fatty acids attached to the ceramide moiety. Fish GA contained only N-acetylneuraminic acid (NeuAc) sialic acid, while beef, chicken, and pork contained GD1a/b species that incorporated both NeuAc and N-glycolylneuraminic acid (NeuGc) and hydroxylated fatty acids.

  18. Determination of the elemental composition of ferromanganese formations certified reference materials by mass-spectrometry with inductively coupled plasma

    Directory of Open Access Journals (Sweden)

    N. V. Zarubina

    2014-01-01

    Full Text Available Contents of 41 elements in the Russian standard samples of ferromanganese nodules OOPE 601, OOPE 602, OOPE 603 and ore crust OOPE 604 were identified by mass-spectrometry with inductively-coupled plasma. Content of W was firstly presented in the sample OOPE-603. Relative standard deviation for most elements was in the range of 3-10%. A description of ICP-MS technique including sample preparation procedure and other instrumental parameters were given as well as analysis of ferromanganese nodules standard samples NOD-A-1 and NOD-P-1 of U.S. Geological Survey was demonstrated for validation. Normalized to chondrite distribution curves of REE in the studied samples were shown as an indicator of the internal consistency offound concentrations. The available literature data on the content of a wide range of elements and its comparison with the matter obtained by us was produced. Measured contents of elements in the established CRM may be useful in the analytical practice to evaluate precision of results. There is a lack of relevant information on a variety of geochemically important elements in the Russian standard samples of OOPE series and the new data can be taken into account in their certification.

  19. Characterization of Chemical Composition of Pericarpium Citri Reticulatae Volatile Oil by Comprehensive Two-Dimensional Gas Chromatography with High-Resolution Time-of-Flight Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Kunming Qin

    2013-01-01

    Full Text Available Pericarpium Citri Reticulatae (Chenpi in Chinese has been widely used as an herbal medicine in Korea, China, and Japan. Chenpi extracts are used to treat indigestion and inflammatory syndromes of the respiratory tract such as bronchitis and asthma. This thesis will analyze chemical compositions of Chenpi volatile oil, which was performed by comprehensive two-dimensional gas chromatography with high-resolution time-of-flight mass spectrometry (GC × GC-HR-TOFMS. One hundred and sixty-seven components were tentatively identified, and terpene compounds are the main components of Chenpi volatile oil, a significant larger number than in previous studies. The majority of the eluted compounds, which were identified, were well separated as a result of high-resolution capability of the GC × GC method, which significantly reduces, the coelution. β-Elemene is tentatively qualified by means of GC × GC in tandem with high-resolution TOFMS detection, which plays an important role in enhancing the effects of many anticancer drugs and in reducing the side effects of chemotherapy. This study suggests that GC × GC-HR-TOFMS is suitable for routine characterization of chemical composition of volatile oil in herbal medicines.

  20. The Potential Impact of Satellite-Retrieved Cloud Parameters on Ground-Level PM2.5 Mass and Composition

    Science.gov (United States)

    Belle, Jessica H.; Chang, Howard H.; Wang, Yujie; Hu, Xuefei; Lyapustin, Alexei; Liu, Yang

    2017-01-01

    Satellite-retrieved aerosol optical properties have been extensively used to estimate ground-level fine particulate matter (PM2.5) concentrations in support of air pollution health effects research and air quality assessment at the urban to global scales. However, a large proportion, approximately 70%, of satellite observations of aerosols are missing as a result of cloud-cover, surface brightness, and snow-cover. The resulting PM2.5 estimates could therefore be biased due to this non-random data missingness. Cloud-cover in particular has the potential to impact ground-level PM2.5 concentrations through complex chemical and physical processes. We developed a series of statistical models using the Multi-Angle Implementation of Atmospheric Correction (MAIAC) aerosol product at 1 km resolution with information from the MODIS cloud product and meteorological information to investigate the extent to which cloud parameters and associated meteorological conditions impact ground-level aerosols at two urban sites in the US: Atlanta and San Francisco. We find that changes in temperature, wind speed, relative humidity, planetary boundary layer height, convective available potential energy, precipitation, cloud effective radius, cloud optical depth, and cloud emissivity are associated with changes in PM2.5 concentration and composition, and the changes differ by overpass time and cloud phase as well as between the San Francisco and Atlanta sites. A case-study at the San Francisco site confirmed that accounting for cloud-cover and associated meteorological conditions could substantially alter the spatial distribution of monthly ground-level PM2.5 concentrations.

  1. The Potential Impact of Satellite-Retrieved Cloud Parameters on Ground-Level PM2.5 Mass and Composition

    Directory of Open Access Journals (Sweden)

    Jessica H. Belle

    2017-10-01

    Full Text Available Satellite-retrieved aerosol optical properties have been extensively used to estimate ground-level fine particulate matter (PM2.5 concentrations in support of air pollution health effects research and air quality assessment at the urban to global scales. However, a large proportion, ~70%, of satellite observations of aerosols are missing as a result of cloud-cover, surface brightness, and snow-cover. The resulting PM2.5 estimates could therefore be biased due to this non-random data missingness. Cloud-cover in particular has the potential to impact ground-level PM2.5 concentrations through complex chemical and physical processes. We developed a series of statistical models using the Multi-Angle Implementation of Atmospheric Correction (MAIAC aerosol product at 1 km resolution with information from the MODIS cloud product and meteorological information to investigate the extent to which cloud parameters and associated meteorological conditions impact ground-level aerosols at two urban sites in the US: Atlanta and San Francisco. We find that changes in temperature, wind speed, relative humidity, planetary boundary layer height, convective available potential energy, precipitation, cloud effective radius, cloud optical depth, and cloud emissivity are associated with changes in PM2.5 concentration and composition, and the changes differ by overpass time and cloud phase as well as between the San Francisco and Atlanta sites. A case-study at the San Francisco site confirmed that accounting for cloud-cover and associated meteorological conditions could substantially alter the spatial distribution of monthly ground-level PM2.5 concentrations.

  2. Effect of mass concentration of composite phase change material CA-DE on HCFC-141b hydrate induction time and system stability

    Science.gov (United States)

    Li, Juan; Sun, Zhigao; Liu, Chenggang; Zhu, Minggui

    2018-03-01

    HCFC-141b hydrate is a new type of environment-friendly cold storage medium which may be adopted to balance energy supply and demand, achieve peak load shifting and energy saving, wherein the hydrate induction time and system stability are key factors to promote and realize its application in industrial practice. Based on step cooling curve measurement, two kinds of aliphatic hydrocarbon organics, n-capric acid (CA) and lauryl alcohol (DE), were selected to form composite phase change material and to promote the generation of HCFC-141b hydrate. Five kinds of CA-DE mass concentration were chosen to compare the induction time and hydration system stability. In order to accelerate temperature reduction rate, the metal Cu with high heat conductivity performance was adopted to conduct out the heat generated during phase change. Instability index was introduced to appraise system stability. Experimental results show that phase change temperature and sub-cooling degree of CA-DE is 11.1°C and 3.0°C respectively, which means it is a preferable medium for HCFC-141b hydrate formation. For the experimental hydration systems, segmented emulsification is achieved by special titration manner to avoid rapid layering under static condition. Induction time can achieve up to 23.3min with the densest HCFC-141b hydrate and the lowest instability index, wherein CA-DE mass concentration is 3%.

  3. Liquid chromatographic/electrospray ionization quadrupole/time of flight tandem mass spectrometric study of polyphenolic composition of different Vaccinium berry species and their comparative evaluation.

    Science.gov (United States)

    Ancillotti, Claudia; Ciofi, Lorenzo; Rossini, Daniele; Chiuminatto, Ugo; Stahl-Zeng, Jianru; Orlandini, Serena; Furlanetto, Sandra; Del Bubba, Massimo

    2017-02-01

    Ultra-high-performance liquid chromatography coupled with high-resolution quadrupole-time of flight mass spectrometry with both negative and positive ionization was used for comprehensively investigating the phenolic and polyphenolic compounds in berries from three spontaneous or cultivated Vaccinium species (i.e., Vaccinium myrtillus, Vaccinium uliginosum subsp. gaultherioides, and Vaccinium corymbosum). More than 200 analytes, among phenolic and polyphenolic compounds belonging to the classes of anthocyanins, monomeric and oligomeric flavonols, flavanols, dihydrochalcones, phenolic acids, together with other polyphenolic compounds of mixed structural characteristics, were identified. Some of the polyphenols herein investigated, such as anthocyanidin glucuronides and malvidin-feruloyl-hexosides in V. myrtillus, or anthocyanindin aldopentosides and coumaroyl-hexosides in V. uliginosum subsp. gaultherioides and a large number of proanthocyanidins with high molecular weight in all species, were described for the first time in these berries. Principal component analysis applied on original LC-TOF data, acquired in survey scan mode, successfully discriminated the three Vaccinium berry species investigated, on the basis of their polyphenolic composition, underlying one more time the fundamental role of mass spectrometry for food characterization.

  4. The effect of dairy intake on bone mass and body composition in early pubertal girls and boys: a randomized controlled trial.

    Science.gov (United States)

    Vogel, Kara A; Martin, Berdine R; McCabe, Linda D; Peacock, Munro; Warden, Stuart J; McCabe, George P; Weaver, Connie M

    2017-05-01

    Background: Calcium retention increases with increasing body mass index (BMI) on recommended calcium intakes. Dairy foods are an excellent source of essential nutrients that are needed to increase bone mineral content (BMC) and potentially decrease fracture. Objective: We compared children who were overweight with children who were healthy weight for the accrual of bone mass in response to an extra 3 servings dairy/d compared with usual intake. Design: Participants were 240 healthy boys and girls (64%), aged 8-15.9 y (mean ± SD age: 11.8 ± 1.5 y), who consumed low amounts of dairy (hip were observed between subjects who received the dairy intervention (achieved consumption of 1500 mg Ca/d) and subjects who did not (achieved 1000 mg Ca/d, which represented ∼2 cups milk or other dairy as part of the diet) with the exception of a tibial BMC gain, which was greater in the group who were given dairy ( P = 0.02). Body fat was not influenced by the diet assignment. Conclusions: Dairy food interventions generally had no effect on bone mineral acquisition or body composition either within or between weight groups. This study suggests that 2 cups milk or the dairy equivalent is adequate for normal bone gain between ages 8 and 16 y. This trial was registered at clinicaltrials.gov as NCT00635583. © 2017 American Society for Nutrition.

  5. Standard test method for analysis of isotopic composition of uranium in nuclear-grade fuel material by quadrupole inductively coupled plasma-mass spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This test method is applicable to the determination of the isotopic composition of uranium (U) in nuclear-grade fuel material. The following isotopic weight percentages are determined using a quadrupole inductively coupled plasma-mass spectrometer (Q-ICP-MS): 233U, 234U, 235U, 236U, and 238U. The analysis can be performed on various material matrices after acid dissolution and sample dilution into water or dilute nitric (HNO3) acid. These materials include: fuel product, uranium oxide, uranium oxide alloys, uranyl nitrate (UNH) crystals, and solutions. The sample preparation discussed in this test method focuses on fuel product material but may be used for uranium oxide or a uranium oxide alloy. Other preparation techniques may be used and some references are given. Purification of the uranium by anion-exchange extraction is not required for this test method, as it is required by other test methods such as radiochemistry and thermal ionization mass spectroscopy (TIMS). This test method is also described i...

  6. Aroma composition of red wines by different extraction methods and Gas Chromatography-SIM/MASS spectrometry analysis.

    Science.gov (United States)

    Genovese, Alessandro; Dimaggio, Rosa; Lisanti, Maria Tiziana; Piombino, Paola; Moio, Luigi

    2005-06-01

    One hundred and one volatile compounds, reported in literature as powerful odorants of wine, were quantified by Gas Chromatography-Selective Ion Monitoring/Mass Spectrometry (GC-SIM/MS) in Primitivo, Aglianico, Merlot and Cabernet Sauvignon red wines. Wine samples were extracted by 3 different extraction methods: 1) separation of the alcoholic fraction from the aqueous phase by salting-out and subsequent extraction by liquid-liquid micro-extraction with 1,1,2-trichlorotrifluoroethane (Freon 113); 2) extraction by liquid-liquid micro-extraction with dichloromethane; 3) solid phase extraction (SPE cartridge: 800 mg of LiChrolut EN resin) with pentane-dichloromethane (20:1) and dichloromethane. The selection of the ion fragments used for quantification was directly performed on a red wine sample. For each compound the area of the corresponding peak was normalized respect to the peak of the internal standard and then interpolated in a calibration curve obtained analysing a model wine solution (water, ethanol, tartaric acid and known amounts of analytes and of internal standard). The methods showed a good linearity: r2>0.990, except for farnesol (isomer a and c), octanal, decanal, furaneol and phenylacetic acid with 0.966 furaneol and sotolon. The Aglianico wines were characterised by the major fermentation compounds (esters, fatty acids and 2-phenylethanol), beta-damascenone, beta-ionone and linalool. The Primitivo wines were characterized by furaneol, methoxypyrazine, gamma-nonalactone and acetaldehyde, while Cabernet Sauvignon and Merlot wines principally by cask derivates (vanillin, (Z) 3-methyl-gamma-octalactone [(Z) wiskylactone], maltol and eugenol), some aldehydes and 3-isopropyl-2-methoxypyrazine.

  7. Correlation of precursor and product ions in single-stage high resolution mass spectrometry. A tool for detecting diagnostic ions and improving the precursor elemental composition elucidation

    Energy Technology Data Exchange (ETDEWEB)

    Borràs, S. [Departament de Química Analítica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Kaufmann, A., E-mail: anton.kaufmann@klzh.ch [Official Food Control Authority, Fehrenstrasse 15, 8032 Zürich (Switzerland); Companyó, R. [Departament de Química Analítica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain)

    2013-04-15

    Highlights: ► We are describing a technique to spot ions which are derived from each other. ► Single stage high resolution data is used. ► This “in silicon” technique is compared to conventional precursor scan. ► Some applications for this technique are presented. -- Abstract: Monitoring of common diagnostic fragments is essential for recognizing molecules which are members of a particular compound class. Up to now, unit resolving tandem quadrupole mass spectrometers, operating in the precursor ion scan mode, have been typically used to perform such analysis. By means of high-resolution mass spectrometry (HRMS) a much more sensitive and selective detection can be achieved. However, using a single-stage HRMS instrument, there is no unequivocal link to the corresponding precursor ion, since such instrumentation does not permit a previous precursor selection. Thus, to address this limitation, an in silico approach to locate precursor ions, based on diagnostic fragments, was developed. Implemented as an Excel macro, the algorithm rapidly assembles and surveys exact mass data to provide a list of feasible precursor candidates according to the correlation of the chromatographic peak shape profile and other additional filtering criteria (e.g. neutral losses and isotopes). The macro was tested with two families of veterinary drugs, sulfonamides and penicillins, which are known to yield diagnostic product ions when fragmented. Data sets obtained from different food matrices (fish and liver), both at high and low concentration of the target compounds, were investigated in order to evaluate the capabilities and limitations of the reported approach. Finally, other possible applications of this technique, such as the elucidation of elemental compositions based on product ions and corresponding neutral losses, were also presented and discussed.

  8. Correlation of precursor and product ions in single-stage high resolution mass spectrometry. A tool for detecting diagnostic ions and improving the precursor elemental composition elucidation

    International Nuclear Information System (INIS)

    Borràs, S.; Kaufmann, A.; Companyó, R.

    2013-01-01

    Highlights: ► We are describing a technique to spot ions which are derived from each other. ► Single stage high resolution data is used. ► This “in silicon” technique is compared to conventional precursor scan. ► Some applications for this technique are presented. -- Abstract: Monitoring of common diagnostic fragments is essential for recognizing molecules which are members of a particular compound class. Up to now, unit resolving tandem quadrupole mass spectrometers, operating in the precursor ion scan mode, have been typically used to perform such analysis. By means of high-resolution mass spectrometry (HRMS) a much more sensitive and selective detection can be achieved. However, using a single-stage HRMS instrument, there is no unequivocal link to the corresponding precursor ion, since such instrumentation does not permit a previous precursor selection. Thus, to address this limitation, an in silico approach to locate precursor ions, based on diagnostic fragments, was developed. Implemented as an Excel macro, the algorithm rapidly assembles and surveys exact mass data to provide a list of feasible precursor candidates according to the correlation of the chromatographic peak shape profile and other additional filtering criteria (e.g. neutral losses and isotopes). The macro was tested with two families of veterinary drugs, sulfonamides and penicillins, which are known to yield diagnostic product ions when fragmented. Data sets obtained from different food matrices (fish and liver), both at high and low concentration of the target compounds, were investigated in order to evaluate the capabilities and limitations of the reported approach. Finally, other possible applications of this technique, such as the elucidation of elemental compositions based on product ions and corresponding neutral losses, were also presented and discussed

  9. Determination of the alkylpyrazine composition of coffee using stable isotope dilution-gas chromatography-mass spectrometry (SIDA-GC-MS).

    Science.gov (United States)

    Pickard, Stephanie; Becker, Irina; Merz, Karl-Heinz; Richling, Elke

    2013-07-03

    A stable isotope dilution analysis based on gas chromatography-mass spectrometry analysis (SIDA-GC-MS) was developed for the quantitative analysis of 12 alkylpyrazines found in commercially available coffee samples. These compounds contribute to coffee flavor. The accuracy of this method was tested by analyzing model mixtures of alkylpyrazines. Comparisons of alkylpyrazine-concentrations suggested that water as extraction solvent was superior to dichloromethane. The distribution patterns of alkylpyrazines in different roasted coffees were quite similar. The most abundant alkylpyrazine in each coffee sample was 2-methylpyrazine, followed by 2,6-dimethylpyrazine, 2,5-dimethylpyrazine, 2-ethylpyrazine, 2-ethyl-6-methylpyrazine, 2-ethyl-5-methylpyrazine, and 2,3,5-trimethylpyrazine, respectively. Among the alkylpyrazines tested, 2,3-dimethylpyrazine, 2-ethyl-3-methylpyrazine, 2-ethyl-3,6-dimethylpyrazine, and 2-ethyl-3,5-dimethylpyrazine revealed the lowest concentrations in roasted coffee. By the use of isotope dilution analysis, the total concentrations of alkylpyrazines in commercially available ground coffee ranged between 82.1 and 211.6 mg/kg, respectively. Decaffeinated coffee samples were found to contain lower amounts of alkylpyrazines than regular coffee samples by a factor of 0.3-0.7, which might be a result of the decaffeination procedure.

  10. The effects of a high dosage of creatine and caffeine supplementation on the lean body mass composition of rats submitted to vertical jumping training.

    Science.gov (United States)

    Franco, Frederico Sc; Costa, Neuza Mb; Ferreira, Susana A; Carneiro-Junior, Miguel A; Natali, Antônio J

    2011-03-01

    The influences of creatine and caffeine supplementation associated with power exercise on lean body mass (LBM) composition are not clear. The purpose of this research was to determine whether supplementation with high doses of creatine and caffeine, either solely or combined, affects the LBM composition of rats submitted to vertical jumping training. Male Wistar rats were randomly divided into 8 groups: Sedentary (S) or Exercised (E) [placebo (Pl), creatine (Cr), caffeine (Caf) or creatine plus caffeine (CrCaf)]. The supplemented groups received creatine [load: 0.430 g/kg of body weight (BW) for 7 days; and maintenance: 0.143 g/kg of BW for 35 days], caffeine (15 mg/kg of BW for 42 days) or creatine plus caffeine. The exercised groups underwent a vertical jump training regime (load: 20 - 50% of BW, 4 sets of 10 jumps interspersed with 1 min resting intervals), 5 days/wk, for 6 weeks. LBM composition was evaluated by portions of water, protein and fat in the rat carcass. Data were submitted to ANOVA followed by the Tukey post hoc test and Student's t test. Exercised animals presented a lower carcass weight (10.9%; P = 0.01), as compared to sedentary animals. However, no effect of supplementation was observed on carcass weight (P > 0.05). There were no significant differences among the groups (P > 0.05) for percentage of water in the carcass. The percentage of fat in the group SCr was higher than in the groups SCaf and ECr (P < 0.05). A higher percentage of protein was observed in the groups EPl and ECaf when compared to the groups SPl and SCaf (P < 0.001). The percentage of fat in the carcass decreased (P < 0.001), while those of water and protein increased (P < 0.05) in exercised animals, compared to sedentary animals. Caffeine groups presented reduced percentage of fat when compared to creatine supplemented groups (P < 0.05). High combined doses of creatine and caffeine does not affect the LBM composition of either sedentary or exercised rats, however, caffeine

  11. Diagnosing Eyewitness Accuracy

    OpenAIRE

    Russ, Andrew

    2015-01-01

    Eyewitnesses frequently mistake innocent people for the perpetrator of an observed crime. Such misidentifications have led to the wrongful convictions of many people. Despite this, no reliable method yet exists to determine eyewitness accuracy. This thesis explored two new experimental methods for this purpose. Chapter 2 investigated whether repetition priming can measure prior exposure to a target and compared this with observers’ explicit eyewitness accuracy. Across three experiments slower...

  12. Application of AFINCH as a tool for evaluating the effects of streamflow-gaging-network size and composition on the accuracy and precision of streamflow estimates at ungaged locations in the southeast Lake Michigan hydrologic subregion

    Science.gov (United States)

    Koltun, G.F.; Holtschlag, David J.

    2010-01-01

    Bootstrapping techniques employing random subsampling were used with the AFINCH (Analysis of Flows In Networks of CHannels) model to gain insights into the effects of variation in streamflow-gaging-network size and composition on the accuracy and precision of streamflow estimates at ungaged locations in the 0405 (Southeast Lake Michigan) hydrologic subregion. AFINCH uses stepwise-regression techniques to estimate monthly water yields from catchments based on geospatial-climate and land-cover data in combination with available streamflow and water-use data. Calculations are performed on a hydrologic-subregion scale for each catchment and stream reach contained in a National Hydrography Dataset Plus (NHDPlus) subregion. Water yields from contributing catchments are multiplied by catchment areas and resulting flow values are accumulated to compute streamflows in stream reaches which are referred to as flow lines. AFINCH imposes constraints on water yields to ensure that observed streamflows are conserved at gaged locations.  Data from the 0405 hydrologic subregion (referred to as Southeast Lake Michigan) were used for the analyses. Daily streamflow data were measured in the subregion for 1 or more years at a total of 75 streamflow-gaging stations during the analysis period which spanned water years 1971–2003. The number of streamflow gages in operation each year during the analysis period ranged from 42 to 56 and averaged 47. Six sets (one set for each censoring level), each composed of 30 random subsets of the 75 streamflow gages, were created by censoring (removing) approximately 10, 20, 30, 40, 50, and 75 percent of the streamflow gages (the actual percentage of operating streamflow gages censored for each set varied from year to year, and within the year from subset to subset, but averaged approximately the indicated percentages).Streamflow estimates for six flow lines each were aggregated by censoring level, and results were analyzed to assess (a) how the

  13. Methods for recalibration of mass spectrometry data

    Science.gov (United States)

    Tolmachev, Aleksey V [Richland, WA; Smith, Richard D [Richland, WA

    2009-03-03

    Disclosed are methods for recalibrating mass spectrometry data that provide improvement in both mass accuracy and precision by adjusting for experimental variance in parameters that have a substantial impact on mass measurement accuracy. Optimal coefficients are determined using correlated pairs of mass values compiled by matching sets of measured and putative mass values that minimize overall effective mass error and mass error spread. Coefficients are subsequently used to correct mass values for peaks detected in the measured dataset, providing recalibration thereof. Sub-ppm mass measurement accuracy has been demonstrated on a complex fungal proteome after recalibration, providing improved confidence for peptide identifications.

  14. Depth-resolved sample composition analysis using laser-induced ablation-quadrupole mass spectrometry and laser-induced breakdown spectroscopy

    Science.gov (United States)

    Oelmann, J.; Gierse, N.; Li, C.; Brezinsek, S.; Zlobinski, M.; Turan, B.; Haas, S.; Linsmeier, Ch.

    2018-06-01

    Monitoring a sample's material composition became more and more important over the last years for both - industrial process control as well as for post mortem analysis in research and industrial development. Although material composition identification as well as a comparison with standard samples works fine, there is a lack of diagnostics which can provide quantitative information with depth resolution without any standard samples. We present a novel method utilizing a residual gas analysis with quadrupole mass spectrometry after picosecond laser-induced ablation and release of volatile species. In the present experiment, well characterized multilayer thin film solar cells (μc-Si:H and a-Si:D as p-i-n-junctions on ZnO:Al electrodes) are used as a set of well characterized material samples to demonstrate the capabilities of the new method. The linearity of the spectrometer signal to gas pressure simplifies its calibration and reduces its uncertainties in comparison with other analysis techniques, although high vacuum conditions (10-6 hPa to 10-7 hPa) are required to reach high sensitivity better than the percent-range. Moreover, the laser-ablation based sample analysis requires no preparation of the sample and is flexible regarding ablation rates. The application of a picosecond laser pulse ensures that the thermal penetration depth of the laser is in the same order of magnitude as the ablation rate, which enables to achieve depth resolutions in the order of 100 nm and avoids matrix mixing effects at the edge of the laser-induced crater in the sample.

  15. Overlay accuracy fundamentals

    Science.gov (United States)

    Kandel, Daniel; Levinski, Vladimir; Sapiens, Noam; Cohen, Guy; Amit, Eran; Klein, Dana; Vakshtein, Irina

    2012-03-01

    Currently, the performance of overlay metrology is evaluated mainly based on random error contributions such as precision and TIS variability. With the expected shrinkage of the overlay metrology budget to DBO (1st order diffraction based overlay). It is demonstrated that the sensitivity of DBO to overlay mark asymmetry is larger than the sensitivity of imaging overlay. Finally, we show that a recently developed measurement quality metric serves as a valuable tool for improving overlay metrology accuracy. Simulation results demonstrate that the accuracy of imaging overlay can be improved significantly by recipe setup optimized using the quality metric. We conclude that imaging overlay metrology, complemented by appropriate use of measurement quality metric, results in optimal overlay accuracy.

  16. Inferences on mass composition and tests of hadronic interactions from 0.3 to 100 EeV using the water-Cherenkov detectors of the Pierre Auger Observatory

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Al Samarai, I.; Albuquerque, I.F.M.; Allekotte, I.; Almela, M.; Zuccarello, F.; van den Berg, Adriaan; Scholten, Olaf

    2017-01-01

    We present a new method for probing the hadronic interaction models atultrahigh energy and extracting details about mass composition. This isdone using the time profiles of the signals recorded with thewater-Cherenkov detectors of the Pierre Auger Observatory. The profilesarise from a mix of the

  17. Constitutive mass balance relations between chemical composition, volume, density, porosity, and strain in metasomatic hydrochemical systems: Results on weathering and pedogenesis

    Science.gov (United States)

    Brimhall, George H.; Dietrich, William E.

    1987-03-01

    Relations characterizing the chemical, physical, and mechanical changes resulting from metasomatic hydrochemical processes are developed using mass balance models which formally link chemical composition to bulk density, mineral density, volumetric properties, porosity, and amount of deformation (strain). Rigorous analysis of aqueous solute transport effects is then made possible in a variety of porous media flow environments including chemical weathering, pedogenesis (soil formation), diagenesis, ore deposition and enrichment, and metamorphism. Application of these linear constitutive relations to chemical weathering profiles shows that immobile and locally mobile chemical elements, with masses conserved on the scale of soil profiles, can be accurately identified from analysis of appropriate data arrays and then used as natural geochemical tracers to infer the nature and extent of hydrochemical weathering processes and volume changes during pedogenesis. Assumptions commonly made in the past about the supposed immobility of certain elements, e.g., Ti and Zr, become unnecessary. Quantitative differentiation between the effects of residual and supergene fractionation is then easily made. These methods are applied to Ni-rich laterites developed by weathering of ultramafic rocks, showing that during ordinary residual enrichment, Ni is concentrated by as much as 4× protolith peridotite concentrations. This occurs simply by silicate mineral dissolution and removal of chemical elements other than Ni ( e.g., Mg) with a corresponding reduction in saprolite density and increase in bulk porosity without significant deformation. In contrast, laterites with mineable concentrations of Ni which are similarly undeformed (such as the Nickel Mountain Mine in Riddle, Oregon) have experienced, in addition to residual enrichment, strong supergene enrichment by fractionation of ore elements between a leached zone from which Ni is extracted and a complementary enriched zone positioned

  18. [Analysis of X-Ray Fluorescence Spectroscopy and Plasma Mass Spectrometry of Pangxidong Composite Granitoid Pluton and Its Implications for Magmatic Differentiation].

    Science.gov (United States)

    Zeng, Chang-yu; Ding, Ru-xin; Li, Hong-zhong; Zhou, Yong-zhang; Niu, Jia; Zhang, Jie-tang

    2015-11-01

    Pangxidong composite granitoid pluton located in the southwestern margin of Yunkai massif. The metamorphic grade of this pluton increases from outside to inside, that is, banded-augen granitic gneisses, gneissoid granites and granites distribute in order from edge to core. X-Ray Fluorescence Spectroscopy and Plasma Mass Spectrometry are conducted to study the geochemical characteristics of the three types of rocks. The result shows that all the three types of rocks are peraluminous rocks and their contents of main elements and rare earth elements change gradually. From granitic gneisses to granites, the contents of Al₂O₃, CaO, MgO, TiO₂, total rare earth elements and light rare earth elements increase, but the contents of SiO₂ and heavy rare earth elements decrease. It is suggested that the phylogenetic relationship exists between granitic gneisses, gneissoid granites and granites during the multi-stage tectonic evolution process. Furthermore, the remelting of metamorphosed supracrustal rocks in Yunkai massif is probably an important cause of granitoid rocks forming. The evolutionary mechanism is probably that SiO₂ and heavy rare earth elements were melt out from the protolith and gradually enriched upward, but Al₂O₃, CaO, MgO, TiO₂ and light rare earth elements enriched downward.

  19. Boundary layer aerosol size distribution, mass concentration and mineralogical composition in Morocco and at Cape Verde Islands during SAMUM I-II

    Science.gov (United States)

    Kandler, K.; Lieke, K.

    2009-04-01

    The Saharan Mineral Dust Experiment (SAMUM) is dedicated to the understanding of the radiative effects of mineral dust. Two major field experiments were performed: A first joint field campaign took place at Ouarzazate and near Zagora, southern Morocco, from May 13 to June 7, 2006. Aircraft and ground based measurements of aerosol physical and chemical properties were carried out to collect a data set of surface and atmospheric columnar information within a major dust source. This data set combined with satellite data provides the base of the first thorough columnar radiative closure tests in Saharan dust. A second field experiment was conducted during January-February 2008, in the Cape Verde Islands region, where about 300 Tg of mineral dust are transported annually from Western Africa across the Atlantic towards the Caribbean Sea and the Amazon basin. Along its transport path, the mineral dust is expected to influence significantly the radiation budget - by direct and indirect effects - of the subtropical North Atlantic. We are lacking a radiative closure in the Saharan air plume. One focus of the investigation within the trade wind region is the spatial distribution of mixed dust/biomass/sea salt aerosol and their physical and chemical properties, especially with regard to radiative effects. We report on measurements of size distributions, mass concentrations and mineralogical composition conducted at the Zagora (Morocco) and Praia (Cape Verde islands) ground stations. The aerosol size distribution was measured from 20 nm to 500

  20. Classification of obesity by means of the body mass index and verification by measurement of the body composition using the tritium dilution technique

    International Nuclear Information System (INIS)

    Leonhardt, W.; Fischer, S.; Weck, M.; Hanefeld, M.

    1988-01-01

    65 female and 142 male patients have been classified according to their body mass index (BMI) into the categories underweight (BMI 20 or less), normal weight (BMI over 20 - 25), overweight (BMI over 25 - 30), obesity (BMI over 30 - 40), and morbid obesity (BMI over 40). Body composition was measured in all patients using the tritium dilution method. Total body fat was calculated from the total body water values. Relative fat values increased from 17.1% (women) and 14.5% (men) resp. in underweight to 46.2% (women) and 43.3% (men) in morbid obesity. In all classes of BMI men exhibited higher values of body weight, body height and body water and lower values of absolute and relative fat as compared to women. However, the relative fat and water values, relative to 1 in the normal weight class, were equal for both sexes. The results demonstrate that the BMI is very well suited for the classification of obesity. (author)

  1. Characterization of ANFO explosive by high accuracy ESI(±)-FTMS with forensic identification on real samples by EASI(-)-MS.

    Science.gov (United States)

    Hernandes, Vinicius Veri; Franco, Marcos Fernado; Santos, Jandyson Machado; Melendez-Perez, Jose J; de Morais, Damila Rodrigues; Rocha, Werickson Fortunato de Carvalho; Borges, Rodrigo; de Souza, Wanderley; Zacca, Jorge Jardim; Logrado, Lucio Paulo Lima; Eberlin, Marcos Nogueira; Correa, Deleon Nascimento

    2015-04-01

    Ammonium nitrate fuel oil (ANFO) is an explosive used in many civil applications. In Brazil, ANFO has unfortunately also been used in criminal attacks, mainly in automated teller machine (ATM) explosions. In this paper, we describe a detailed characterization of the ANFO composition and its two main constituents (diesel and a nitrate explosive) using high resolution and accuracy mass spectrometry performed on an FT-ICR-mass spectrometer with electrospray ionization (ESI(±)-FTMS) in both the positive and negative ion modes. Via ESI(-)-MS, an ion marker for ANFO was characterized. Using a direct and simple ambient desorption/ionization technique, i.e., easy ambient sonic-spray ionization mass spectrometry (EASI-MS), in a simpler, lower accuracy but robust single quadrupole mass spectrometer, the ANFO ion marker was directly detected from the surface of banknotes collected from ATM explosion theft. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Comprehensive profiling of ribonucleosides modification by affinity zirconium oxide-silica composite monolithic column online solid-phase microextraction - Mass spectrometry analysis.

    Science.gov (United States)

    Jiang, Han-Peng; Chu, Jie-Mei; Lan, Meng-Dan; Liu, Ping; Yang, Na; Zheng, Fang; Yuan, Bi-Feng; Feng, Yu-Qi

    2016-09-02

    More than 140 modified ribonucleosides have been identified in RNA. Determination of endogenous modified ribonucleosides in biological fluids may serve as non-invasive disease diagnostic strategy. However, detection of the modified ribonucleosides in biological fluids is challenging, especially for the low abundant modified ribonucleosides due to the serious matrix interferences of biological fluids. Here, we developed a facile preparation strategy and successfully synthesized zirconium oxide-silica (ZrO2/SiO2) composite capillary monolithic column that exhibited excellent performance for the selective enrichment of cis-diol-containing compounds. Compared with the boronate-based affinity monolith, the ZrO2/SiO2 monolith showed ∼2 orders of magnitude higher extraction capacity and can be used under physiological pH (pH 6.5-7.5). Using the prepared ZrO2/SiO2 composite monolith as the trapping column and reversed-phase C18 column as the analytical column, we further established an online solid-phase microextraction (SPME) in combination with liquid chromatography-mass spectrometry (online SPME-LC-MS/MS) analysis for the comprehensive profiling of ribonucleosides modification in human urine. Our results showed that 68 cis-diol-containing ribosylated compounds were identified in human urine, which is, to the best of our knowledge, the highest numbers of cis-diol-containing compounds were determined in a single analysis. It is worth noting that four modified ribonucleosides were discovered in the human urine for the first time. In addition, the quantification results from the pooled urine samples showed that compared to healthy controls, the contents of sixteen ribose conjugates in the urine of gastric cancer, eleven in esophagus cancer and seven in lymphoma increased more than two folds. Among these ribose conjugates, four ribose conjugates increased more than two folds in both gastric cancer and esophagus cancer; three ribose conjugates increased more than two

  3. Geoid undulation accuracy

    Science.gov (United States)

    Rapp, Richard H.

    1993-01-01

    The determination of the geoid and equipotential surface of the Earth's gravity field, has long been of interest to geodesists and oceanographers. The geoid provides a surface to which the actual ocean surface can be compared with the differences implying information on the circulation patterns of the oceans. For use in oceanographic applications the geoid is ideally needed to a high accuracy and to a high resolution. There are applications that require geoid undulation information to an accuracy of +/- 10 cm with a resolution of 50 km. We are far from this goal today but substantial improvement in geoid determination has been made. In 1979 the cumulative geoid undulation error to spherical harmonic degree 20 was +/- 1.4 m for the GEM10 potential coefficient model. Today the corresponding value has been reduced to +/- 25 cm for GEM-T3 or +/- 11 cm for the OSU91A model. Similar improvements are noted by harmonic degree (wave-length) and in resolution. Potential coefficient models now exist to degree 360 based on a combination of data types. This paper discusses the accuracy changes that have taken place in the past 12 years in the determination of geoid undulations.

  4. Mass concentration and elemental composition of indoor PM 2.5 and PM 10 in University rooms in Thessaloniki, northern Greece

    Science.gov (United States)

    Gemenetzis, Panagiotis; Moussas, Panagiotis; Arditsoglou, Anastasia; Samara, Constantini

    The mass concentration and the elemental composition of PM 2.5 and PM 10 were measured in 40 rooms (mainly offices or mixed office-lab rooms, and photocopying places) of the Aristotle University of Thessaloniki, northern Greece. A total of 27 major, minor and trace elements were determined by ED-XRF analysis. The PM 2.5/PM 10 concentration ratios averaged 0.8±0.2, while the corresponding elemental ratios ranged between 0.4±0.2 and 0.9±0.2. The concentrations of PM 2.5 and PM 10 were significantly higher (by 70% and 50%, respectively) in the smokers' rooms compared to the non-smokers' places. The total elemental concentrations were also higher in the smokers' rooms (11.5 vs 8.2 μg m -3 for PM 2.5, and 10.3 vs 7.6 μg m -3 for PM 2.5-10). Fine particle concentrations (PM 2.5) were found to be quite proportional to smoking strength. On the contrary, the two environments exhibited similar coarse (PM 2.5-10) particle fractions not related to the number of cigarettes smoked. A slight decrease of particle concentrations with increasing the floor level was also observed, particularly for PM 2.5, suggesting that high-level floors are less impacted by near ground-level sources like traffic emissions. Finally, the removal efficiency of air purification systems was evaluated.

  5. Determination of uranium isotopic composition and 236U content of soil samples and hot particles using inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Boulyga, S F; Becker, J S

    2001-07-01

    As a result of the accident at the Chernobyl nuclear power plant (NPP) the environment was contaminated with spent nuclear fuel. The 236U isotope was used in this study to monitor the spent uranium from nuclear fallout in soil samples collected in the vicinity of the Chernobyl NPP. Nuclear track radiography was applied for the identification and extraction of hot radioactive particles from soil samples. A rapid and sensitive analytical procedure was developed for uranium isotopic ratio measurement in environmental samples based on double-focusing inductively coupled plasma mass spectrometry (DF-ICP-MS) with a MicroMist nebulizer and a direct injection high-efficiency nebulizer (DIHEN). The performance of the DF-ICP-MS with a quartz DIHEN and plasma shielded torch was studied. Overall detection efficiencies of 4 x 10(-4) and 10(-3) counts per atom were achieved for 238U in DF-ICP-QMS with the MicroMist nebulizer and DIHEN, respectively. The rate of formation of uranium hydride ions UH+/U+ was 1.2 x 10(-4) and 1.4 x 10(-4), respectively. The precision of short-term measurements of uranium isotopic ratios (n = 5) in 1 microg L(-1) NBS U-020 standard solution was 0.11% (238U/235U) and 1.4% (236U/238U) using a MicroMist nebulizer and 0.25% (235U/238U) and 1.9% (236U/P38U) using a DIHEN. The isotopic composition of all investigated Chernobyl soil samples differed from those of natural uranium; i.e. in these samples the 236U/238U ratio ranged from 10(-5) to 10(-3). Results obtained with ICP-MS, alpha- and gamma-spectrometry showed differences in the migration properties of spent uranium, plutonium, and americium. The isotopic ratio of uranium was also measured in hot particles extracted from soil samples.

  6. Determination of uranium isotopic composition and 236U content of soil samples and hot particles using inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Boulyga, S.F.; Becker, J.S.

    2001-01-01

    As a result of the accident at the Chernobyl nuclear power plant (NPP) the environment was contaminated with spent nuclear fuel. The 236 U isotope was used in this study to monitor the spent uranium from nuclear fallout in soil samples collected in the vicinity of the Chernobyl NPP. Nuclear track radiography was applied for the identification and extraction of hot radioactive particles from soil samples. A rapid and sensitive analytical procedure was developed for uranium isotopic ratio measurement in environmental samples based on double-focusing inductively coupled plasma mass spectrometry (DF-ICP-MS) with a MicroMist nebulizer and a direct injection high-efficiency nebulizer (DIHEN). The performance of the DF-ICP-MS with a quartz DIHEN and plasma shielded torch was studied. Overall detection efficiencies of 4 x 10 -4 and 10 -3 counts per atom were achieved for 238 U in DF-ICP-QMS with the MicroMist nebulizer and DIHEN, respectively. The rate of formation of uranium hydride ions UH + /U + was 1.2 x 10 -4 and 1.4 x 10 -4 , respectively. The precision of short-term measurements of uranium isotopic ratios (n = 5) in 1 μg L -1 NBS U-020 standard solution was 0.11% ( 238 U/ 235 U) and 1.4% ( 236 U/ 238 U) using a MicroMist nebulizer and 0.25% ( 235 U/ 238 U) and 1.9% ( 236 U/ 238 U) using a DIHEN. The isotopic composition of all investigated Chernobyl soil samples differed from those of natural uranium; i.e. in these samples the 236 U/ 238 U ratio ranged from 10 -5 to 10 -3 . Results obtained with ICP-MS, α- and γ-spectrometry showed differences in the migration properties of spent uranium, plutonium, and americium. The isotopic ratio of uranium was also measured in hot particles extracted from soil samples. (orig.)

  7. Diagnostic accuracy of sonoelastography in different diseases

    Directory of Open Access Journals (Sweden)

    Iqra Manzoor

    2018-03-01

    Full Text Available The objective of this study was to evaluate the diagnostic accuracy of sonoelastography in patients of primary and secondary health care settings. Google scholar, PubMed, Medline, Medscape, Wikipedia and NCBI were searched in October 2017 for all original studies and review articles to identify the relevant material. Two reviewers independently selected articles for evaluation of the diagnostic accuracy of sonoelastography in different diseases based on titles and abstracts retrieved by the literature search. The accuracy of sonoelastography in different diseases was used as the index text, while B-mode sonography, micro pure imaging, surgery and histological findings were used as reference texts. Superficial lymph nodes, neck nodules, malignancy in thyroid nodules, benign and malignant cervical lymph nodes, thyroid nodules, prostate carcinoma, benign and malignant breast abnormalities, liver diseases, parotid and salivary gland masses, pancreatic masses, musculoskeletal diseases and renal disorders were target conditions. The data extracted by the two reviewers concerning selected study characteristics and results were presented in tables and figures. In total, 46 studies were found for breast masses, lymph nodes, prostate carcinoma, liver diseases, salivary and parotid gland diseases, pancreatic masses, musculoskeletal diseases and renal diseases, and the overall sensitivity of sonoelastography in diagnosing all these diseases was 83.14% while specificity was 81.41%. This literature review demonstrates that sonoelastography is characterized by high sensitivity and specificity in diagnosing different disorders of the body.

  8. A bedside measure of body composition in Duchenne muscular dystrophy.

    Science.gov (United States)

    Elliott, Sarah A; Davidson, Zoe E; Davies, Peter S W; Truby, Helen

    2015-01-01

    In clinical practice, monitoring body composition is a critical component of nutritional assessment and weight management in boys with Duchenne muscular dystrophy. We aimed to evaluate the accuracy of a simple bedside measurement tool for body composition, namely bioelectrical impedance analysis, in boys with Duchenne muscular dystrophy. Measures of fat-free mass were determined using a bioelectrical impedance analysis machine and compared against estimations obtained from a reference body composition model. Additionally, the use of raw impedance values was analyzed using three existing predictive equations for the estimation of fat-free mass. Accuracy of bioelectrical impedance analysis was assessed by comparison against the reference model by calculation of biases and limits of agreement. Body composition was measured in 10 boys with Duchenne muscular dystrophy, mean age 9.01 ± 2.34 years. The bioelectrical impedance analysis machine values of fat-free mass were on average 2.3 ± 14.1 kg higher than reference values. Limits of agreement (based on 95% confidence interval of the mean) were -7.4 to 2.9 kg. There was a significant correlation between the mean fat-free mass and difference in fat-free mass between the bioelectrical impedance analysis machine and the reference model (r = -0.86; P = 0.02) suggesting that the bias was not consistent across the range of measurements. The most accurate predictive equation for the estimation of fat-free mass using raw impedance values was the equation by Pietrobelli et al. (mean difference, -0.7 kg; 95% limits of agreement, -3.5 to 2.0 kg). In a clinical setting, where a rapid assessment of body composition is advantageous, the use of raw impedance values, combined with the equation by Pietrobelli et al., is recommended for the accurate estimation of fat-free mass, in boys with Duchenne muscular dystrophy. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Aerosol characterization over the southeastern United States using high resolution aerosol mass spectrometry: spatial and seasonal variation of aerosol composition, sources, and organic nitrates

    Science.gov (United States)

    Xu, L.; Suresh, S.; Guo, H.; Weber, R. J.; Ng, N. L.

    2015-04-01

    We deployed a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and an Aerosol Chemical Speciation Monitor (ACSM) to characterize the chemical composition of submicron non-refractory particles (NR-PM1) in the southeastern US. Measurements were performed in both rural and urban sites in the greater Atlanta area, GA and Centreville, AL for approximately one year, as part of Southeastern Center of Air Pollution and Epidemiology study (SCAPE) and Southern Oxidant and Aerosol Study (SOAS). Organic aerosol (OA) accounts for more than half of NR1 mass concentration regardless of sampling sites and seasons. Positive matrix factorization (PMF) analysis of HR-ToF-AMS measurements identified various OA sources, depending on location and season. Hydrocarbon-like OA (HOA) and cooking OA (COA) have important but not dominant contributions to total OA in urban sites. Biomass burning OA (BBOA) concentration shows a distinct seasonal variation with a larger enhancement in winter than summer. We find a good correlation between BBOA and brown carbon, indicating biomass burning is an important source for brown carbon, although an additional, unidentified brown carbon source is likely present at the rural Yorkville site. Isoprene-derived OA (Isoprene-OA) is only deconvolved in warmer months and contributes 18-36% of total OA. The presence of Isoprene-OA factor in urban sites is more likely from local production in the presence of NOx than transport from rural sites. More-oxidized and less-oxidized oxygenated organic aerosol (MO-OOA and LO-OOA, respectively) are dominant fractions (47-79%) of OA in all sites. MO-OOA correlates well with ozone in summer, but not in winter, indicating MO-OOA sources may vary with seasons. LO-OOA, which reaches a daily maximum at night, correlates better with estimated nitrate functionality from organic nitrates than total nitrates. Based on the HR-ToF-AMS measurements, we estimate that the nitrate functionality from organic nitrates

  10. Massa óssea e composição corporal em estudantes universitários Bone mass and body composition in college students

    Directory of Open Access Journals (Sweden)

    Cristina Reuter

    2012-06-01

    Full Text Available OBJETIVO: Comparar a densidade mineral óssea (DMO e a composição corporal (CC de universitários com diferentes estilos de vida. MÉTODOS: Estudo transversal realizado em 85 estudantes dos cursos de Medicina (MED e Educação Física (EF da Universidade Regional de Blumenau. As variáveis antropométricas, sociodemográficas, clínicas e de estilo de vida foram obtidas por meio de anamnese densitométrica e as variáveis densitométricas por raio-x de dupla energia (DXA. Os testes estatísticos foram: t de Student, qui-quadrado e regressão logística. RESULTADOS: Os acadêmicos de EF apresentaram massa magra maior (79,5 ± 5,9 versus 75,1 ± 5,3; p = 0,03 e gordura corporal menor (16,7 ± 6,1 versus 21,6 ± 5,6; p = 0,02, e as acadêmicas de EF apresentaram massa magra maior (68,2 ± 5,5 versus 65,3 ± 5,5; p = 0,05. A DMO do colo do fêmur (CF, fêmur total (FT e corpo total (CT foi maior nos acadêmicos de EF em ambos os sexos. Os estudantes de EF praticavam mais exercícios físicos do que os de MED. A baixa massa óssea (BMO foi mais frequente nos estudantes de MED (34,9% versus 4,7%; p = 0,001, sendo que o risco de um estudante de MED ter BMO foi 9 vezes maior para a CL, 5 vezes para o CF, 8 vezes para o FT e 7 vezes para o CT. CONCLUSÃO: A CC e a DMO foram diferentes entre os estudantes; os acadêmicos de MED apresentaram um risco maior de ter BMO e os acadêmicos de EF praticavam mais exercícios físicos.OBJECTIVE: To compare bone mineral density (BMD and body composition (BC of college students with different lifestyles. METHODS: Transversal study with 85 students of Medicine (MED and Physical Education (PE at the Universidade Regional de Blumenau, SC, Brazil. The anthropometric, socio-demographic, clinical, and lifestyle variables were obtained through densitometric anamnesis and densitometric variables by dual-energy X-ray (DXA. The statistical tests used were: Student's t-test, Chi-square test, and logistic regression. RESULTS

  11. Accuracy of the WHO’s body mass index cut-off points to measure gender- and age-specific obesity in middle-aged adults living in the city of Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Wollner Materko

    2017-09-01

    Full Text Available Introduction. Obesity is defined by the World Health Organization (WHO as a disease characterized by the excessive accumulation of body fat. Obesity is considered a public health problem, leading to serious social, psychological and physical problems. However, the appropriate cut-off point of body mass index (BMI based on body fat percentage (BF% for classifying an individual as obese in middle-aged adults living in Rio de Janeiro remains unclear. Materials and methods. This was a prospective cross-sectional study comprising of 856 adults (413 men and 443 women living in Rio de Janeiro, Brazil ranging from 30-59 years of age. The data were collected over a two year period (2010-2011, and all participants were underwent anthropometric evaluation. The gold standard was the percentage of body fat estimated by bioelectrical impedance analysis. The optimal sensitivity and specificity were attained by adjusting BMI cut-off values to predict obesity based on the WHO criteria: BF% >25% in men and >35% in women, according to the receiver operating characteristic curve (ROC analysis adjusted for age and for the whole group.Results. The BMI cut-offs for predicting BF% were 29.9 kg/m2 in men and 24.9 kg/m2 in women. Conclusions. The BMI that corresponded to a BF% previously defining obesity was similar to that of other Western populations for men but not for women. Furthermore, gender and age specific cut-off values are recommended in this population.

  12. Accuracy of the Precision® point-of-care ketone test examined by liquid chromatography tandem-mass spectrometry (LC-MS/MS) in the same fingerstick sample.

    Science.gov (United States)

    Janssen, Marcel J W; Hendrickx, Ben H E; Habets-van der Poel, Carin D; van den Bergh, Joop P W; Haagen, Anton A M; Bakker, Jaap A

    2010-12-01

    The Precision(®) (Abbott Diabetes Care) point-of-care biosensor test strips are widely used by patients with diabetes and clinical laboratories for measurement of plasma β-hydroxybutyrate (β-HB) concentrations in capillary blood samples obtained by fingerstick. In the literature, this procedure has been validated only against the enzymatic determination of β-HB in venous plasma, i.e., the method to which the Precision(®) has been calibrated. In this study, the Precision(®) Xceed was compared to a methodologically different and superior procedure: determination of β-HB by liquid chromatography tandem-mass spectrometry (LC-MS/MS) in capillary blood spots. Blood spots were obtained from the same fingerstick sample from out of which Precision(®) measurements were performed. Linearity was tested by adding varying amounts of standard to an EDTA venous whole blood matrix. The Precision(®) was in good agreement with LC-MS/MS within the measuring range of 0.0-6.0 mmol/L (Passing and Bablok regression: slope=1.20 and no significant intercept, R=0.97, n=59). Surprisingly, the Precision(®) showed non-linearity and full saturation at concentrations above 6.0 mmol/L, which were confirmed by a standard addition experiment. Results obtained at the saturation level varied between 3.0 and 6.5 mmol/L. The Precision(®) β-HB test strips demonstrate good comparison with LC-MS/MS. Inter-individual variation around the saturation level, however, is large. Therefore, we advise reporting readings above 3.0 as >3.0 mmol/L. The test is valid for use in the clinically relevant range of 0.0-3.0 mmol/L.

  13. Accuracy of radiocarbon analyses at ANTARES

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, E M; Fink, D; Hotchkis, M; Hua, Q; Jacobsen, G; Smith, A M; Tuniz, C [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1997-12-31

    Accuracy in Accelerator Mass Spectroscopy (AMS) measurements, as distinct from precision, requires the application of a number of corrections. Most of these are well known except in extreme circumstances and AMS can deliver radiocarbon results which are both precise and accurate in the 0.5 to 1.0% range. The corrections involved in obtaining final radiocarbon ages are discussed. 3 refs., 1 tab.

  14. Accuracy of radiocarbon analyses at ANTARES

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, E.M.; Fink, D.; Hotchkis, M.; Hua, Q.; Jacobsen, G.; Smith, A.M.; Tuniz, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    Accuracy in Accelerator Mass Spectroscopy (AMS) measurements, as distinct from precision, requires the application of a number of corrections. Most of these are well known except in extreme circumstances and AMS can deliver radiocarbon results which are both precise and accurate in the 0.5 to 1.0% range. The corrections involved in obtaining final radiocarbon ages are discussed. 3 refs., 1 tab.

  15. Transesterification of canola, palm, peanut, soybean and sunflower oil with methanol, ethanol, isopropanol, butanol and tert-butanol to biodiesel: Modelling of chemical equilibrium, reaction kinetics and mass transfer based on fatty acid composition

    International Nuclear Information System (INIS)

    Likozar, Blaž; Levec, Janez

    2014-01-01

    Graphical abstract: Modelling of chemical equilibrium, reaction kinetics and mass transfer for triglyceride transesterification with different alcohols based on fatty acid composition. - Highlights: • Catalysed transesterification to biodiesel with various oils, alcohols and catalysts. • Analysis of components and reactivity based on fatty acid composition of all species. • Simultaneous modelling of mass transfer, reaction kinetics and chemical equilibrium. • Diffusivities, distribution and mass transfer coefficients for individual components. • Correlation of kinetic parameters with molecular structure of reactants and products. - Abstract: Mechanism of alcoholysis (e.g. methanolysis) using different oils, alcohols and homogeneous base catalysts was utilized to devise chemical kinetics and thermodynamics based on fatty acid composition, differentiating among triglycerides, diglycerides, monoglycerides and fatty acid alkyl esters (e.g. fatty acid alkyl esters, FAME) with bonded gadoleic, linoleic, linolenic, oleic, palmitic and stearic acid-originating substituents. Their concentrations were measured using an optimized high-performance liquid chromatography (HPLC) method. Hydrodynamics and diffusion limitations in emulsion were considered in overall model by determining diffusivities, distribution coefficients, molar volumes, boiling points and viscosities of individual components. Pre-exponential factors and activation energies were related with structure of reactants, intermediates and products acknowledging number of carbons, double bonds and alkyl branches by linear and mixed response surface methodology. Developed model may be used with batch and continuous flow reactors, e.g. for novel micro-structured or industrial-scale process intensification, different vegetable or non-edible oils (waste cooking Jatropha or microalgae lipids)

  16. Determination of uranium isotopic composition and {sup 236}U content of soil samples and hot particles using inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Boulyga, S.F. [Radiation Physics and Chemistry Problems Inst., Minsk (Belarus); Becker, J.S. [Central Department for Analytical Chemistry, Research Centre Juelich (Germany)

    2001-07-01

    As a result of the accident at the Chernobyl nuclear power plant (NPP) the environment was contaminated with spent nuclear fuel. The {sup 236}U isotope was used in this study to monitor the spent uranium from nuclear fallout in soil samples collected in the vicinity of the Chernobyl NPP. Nuclear track radiography was applied for the identification and extraction of hot radioactive particles from soil samples. A rapid and sensitive analytical procedure was developed for uranium isotopic ratio measurement in environmental samples based on double-focusing inductively coupled plasma mass spectrometry (DF-ICP-MS) with a MicroMist nebulizer and a direct injection high-efficiency nebulizer (DIHEN). The performance of the DF-ICP-MS with a quartz DIHEN and plasma shielded torch was studied. Overall detection efficiencies of 4 x 10{sup -4} and 10{sup -3} counts per atom were achieved for {sup 238}U in DF-ICP-QMS with the MicroMist nebulizer and DIHEN, respectively. The rate of formation of uranium hydride ions UH{sup +}/U{sup +} was 1.2 x 10{sup -4} and 1.4 x 10{sup -4}, respectively. The precision of short-term measurements of uranium isotopic ratios (n = 5) in 1 {mu}g L{sup -1} NBS U-020 standard solution was 0.11% ({sup 238}U/{sup 235}U) and 1.4% ({sup 236}U/{sup 238}U) using a MicroMist nebulizer and 0.25% ({sup 235}U/{sup 238}U) and 1.9% ({sup 236}U/{sup 238}U) using a DIHEN. The isotopic composition of all investigated Chernobyl soil samples differed from those of natural uranium; i.e. in these samples the {sup 236}U/{sup 238}U ratio ranged from 10{sup -5} to 10{sup -3}. Results obtained with ICP-MS, {alpha}- and {gamma}-spectrometry showed differences in the migration properties of spent uranium, plutonium, and americium. The isotopic ratio of uranium was also measured in hot particles extracted from soil samples. (orig.)

  17. Tracking changes in composition and amount of dissolved organic matter throughout drinking water treatment plants by comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry.

    Science.gov (United States)

    Li, Chunmei; Wang, Donghong; Xu, Xiong; Xu, Meijia; Wang, Zijian; Xiao, Ruiyang

    2017-12-31

    Dissolved organic matter (DOM) can affect the performance of water treatment processes and produce undesirable disinfection by-products during disinfection. Several studies have been undertaken on the structural characterization of DOM, but its fate during drinking water treatment processes is still not fully understood. In this work, the nontargeted screening method of comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC×GC-qMS) was used to reveal the detailed changes of different chemical classes of compounds in DOM during conventional and advanced drinking water treatment processes at three drinking water treatment plants in China. The results showed that when the dissolved organic carbon removal was low, shifts in the DOM composition could not be detected with the specific ultraviolet absorbance at 254nm, but the changes were clear in the three-dimensional fluorescence excitation-emission matrix or GC×GC-qMS analyses. Coagulation-sedimentation processes selectively removed 37-59% of the nitrogenous compounds, alcohols and aromatic hydrocarbons but increased the concentrations of halogen-containing compounds by 17-26% because of the contact time with chlorine in this step. Filtration was less efficient at removing DOM but preferentially removed 21-60% of the acids. However, other organic matter would be released from the filter (e.g., nitrogenous compounds, acids, and aromatic hydrocarbons). Biological activated carbon (BAC) treatment removed most of the compounds produced from ozonation, particularly ketones, alcohols, halogen-containing compounds and acids. However, it should be noted that certain highly polar or high molecular weight compounds not identified in this study might be released from the BAC bed. After the whole treatment processes, the concentrations of nitrogenous compounds, alcohols, alkenes, aromatic hydrocarbons and ketones were decreased more by the advanced treatment processes than by the conventional treatment

  18. Water mass circulation and weathering inputs in the Labrador Sea based on coupled Hf-Nd isotope compositions and rare earth element distributions

    Science.gov (United States)

    Filippova, Alexandra; Frank, Martin; Kienast, Markus; Rickli, Jörg; Hathorne, Ed; Yashayaev, Igor M.; Pahnke, Katharina

    2017-02-01

    The Labrador Sea is one of the key areas for deep water formation driving the Atlantic thermohaline circulation and thus plays an important role in Northern Hemisphere climatic fluctuations. In order to better constrain the overturning processes and the origins of the distinct water masses, combined dissolved Hf-Nd isotopic compositions and rare earth element (REE) distribution patterns were obtained from four water depth profiles along a section across the Labrador Sea. These were complemented by one surface sample off the southern tip of Greenland, three shallow water samples off the coast of Newfoundland, and two deep water samples off Nova Scotia. Although light REEs are markedly enriched in the surface waters off the coast of Newfoundland compared to north Atlantic waters, the REE concentration profiles are essentially invariant throughout the water column across the Labrador Sea. The hafnium concentrations of surface waters exhibit a narrow range between 0.6 and 1 pmol/kg but are not significantly higher than at depth. Neodymium isotope signatures (ɛNd) vary from unradiogenic values between -16.8 and -14.9 at the surface to more radiogenic values near -11.0 at the bottom of the Labrador Sea mainly reflecting the advection of the Denmark Strait Overflow Water and North East Atlantic Deep Water, the signatures of which are influenced by weathering contributions from Icelandic basalts. Unlike Nd, water column radiogenic Hf isotope signatures (ɛHf) are more variable representing diverse weathering inputs from the surrounding landmasses. The least radiogenic seawater ɛHf signatures (up to -11.7) are found in surface waters close to Greenland and near the Canadian margin. This reflects the influence of recirculating Irminger Current Waters, which are affected by highly unradiogenic inputs from Greenland. A three to four ɛHf unit difference is observed between Denmark Strait Overflow Water (ɛHf ∼ -4) and North East Atlantic Deep Water (ɛHf ∼ -0

  19. Genomic selection and association mapping in rice (Oryza sativa): effect of trait genetic architecture, training population composition, marker number and statistical model on accuracy of rice genomic selection in elite, tropical rice breeding lines.

    Science.gov (United States)

    Spindel, Jennifer; Begum, Hasina; Akdemir, Deniz; Virk, Parminder; Collard, Bertrand; Redoña, Edilberto; Atlin, Gary; Jannink, Jean-Luc; McCouch, Susan R

    2015-02-01

    Genomic Selection (GS) is a new breeding method in which genome-wide markers are used to predict the breeding value of individuals in a breeding population. GS has been shown to improve breeding efficiency in dairy cattle and several crop plant species, and here we evaluate for the first time its efficacy for breeding inbred lines of rice. We performed a genome-wide association study (GWAS) in conjunction with five-fold GS cross-validation on a population of 363 elite breeding lines from the International Rice Research Institute's (IRRI) irrigated rice breeding program and herein report the GS results. The population was genotyped with 73,147 markers using genotyping-by-sequencing. The training population, statistical method used to build the GS model, number of markers, and trait were varied to determine their effect on prediction accuracy. For all three traits, genomic prediction models outperformed prediction based on pedigree records alone. Prediction accuracies ranged from 0.31 and 0.34 for grain yield and plant height to 0.63 for flowering time. Analyses using subsets of the full marker set suggest that using one marker every 0.2 cM is sufficient for genomic selection in this collection of rice breeding materials. RR-BLUP was the best performing statistical method for grain yield where no large effect QTL were detected by GWAS, while for flowering time, where a single very large effect QTL was detected, the non-GS multiple linear regression method outperformed GS models. For plant height, in which four mid-sized QTL were identified by GWAS, random forest produced the most consistently accurate GS models. Our results suggest that GS, informed by GWAS interpretations of genetic architecture and population structure, could become an effective tool for increasing the efficiency of rice breeding as the costs of genotyping continue to decline.

  20. Genomic selection and association mapping in rice (Oryza sativa: effect of trait genetic architecture, training population composition, marker number and statistical model on accuracy of rice genomic selection in elite, tropical rice breeding lines.

    Directory of Open Access Journals (Sweden)

    Jennifer Spindel

    2015-02-01

    Full Text Available Genomic Selection (GS is a new breeding method in which genome-wide markers are used to predict the breeding value of individuals in a breeding population. GS has been shown to improve breeding efficiency in dairy cattle and several crop plant species, and here we evaluate for the first time its efficacy for breeding inbred lines of rice. We performed a genome-wide association study (GWAS in conjunction with five-fold GS cross-validation on a population of 363 elite breeding lines from the International Rice Research Institute's (IRRI irrigated rice breeding program and herein report the GS results. The population was genotyped with 73,147 markers using genotyping-by-sequencing. The training population, statistical method used to build the GS model, number of markers, and trait were varied to determine their effect on prediction accuracy. For all three traits, genomic prediction models outperformed prediction based on pedigree records alone. Prediction accuracies ranged from 0.31 and 0.34 for grain yield and plant height to 0.63 for flowering time. Analyses using subsets of the full marker set suggest that using one marker every 0.2 cM is sufficient for genomic selection in this collection of rice breeding materials. RR-BLUP was the best performing statistical method for grain yield where no large effect QTL were detected by GWAS, while for flowering time, where a single very large effect QTL was detected, the non-GS multiple linear regression method outperformed GS models. For plant height, in which four mid-sized QTL were identified by GWAS, random forest produced the most consistently accurate GS models. Our results suggest that GS, informed by GWAS interpretations of genetic architecture and population structure, could become an effective tool for increasing the efficiency of rice breeding as the costs of genotyping continue to decline.

  1. Genomic Selection and Association Mapping in Rice (Oryza sativa): Effect of Trait Genetic Architecture, Training Population Composition, Marker Number and Statistical Model on Accuracy of Rice Genomic Selection in Elite, Tropical Rice Breeding Lines

    Science.gov (United States)

    Spindel, Jennifer; Begum, Hasina; Akdemir, Deniz; Virk, Parminder; Collard, Bertrand; Redoña, Edilberto; Atlin, Gary; Jannink, Jean-Luc; McCouch, Susan R.

    2015-01-01

    Genomic Selection (GS) is a new breeding method in which genome-wide markers are used to predict the breeding value of individuals in a breeding population. GS has been shown to improve breeding efficiency in dairy cattle and several crop plant species, and here we evaluate for the first time its efficacy for breeding inbred lines of rice. We performed a genome-wide association study (GWAS) in conjunction with five-fold GS cross-validation on a population of 363 elite breeding lines from the International Rice Research Institute's (IRRI) irrigated rice breeding program and herein report the GS results. The population was genotyped with 73,147 markers using genotyping-by-sequencing. The training population, statistical method used to build the GS model, number of markers, and trait were varied to determine their effect on prediction accuracy. For all three traits, genomic prediction models outperformed prediction based on pedigree records alone. Prediction accuracies ranged from 0.31 and 0.34 for grain yield and plant height to 0.63 for flowering time. Analyses using subsets of the full marker set suggest that using one marker every 0.2 cM is sufficient for genomic selection in this collection of rice breeding materials. RR-BLUP was the best performing statistical method for grain yield where no large effect QTL were detected by GWAS, while for flowering time, where a single very large effect QTL was detected, the non-GS multiple linear regression method outperformed GS models. For plant height, in which four mid-sized QTL were identified by GWAS, random forest produced the most consistently accurate GS models. Our results suggest that GS, informed by GWAS interpretations of genetic architecture and population structure, could become an effective tool for increasing the efficiency of rice breeding as the costs of genotyping continue to decline. PMID:25689273

  2. Correlation of rocket propulsion fuel properties with chemical composition using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry followed by partial least squares regression analysis.

    Science.gov (United States)

    Kehimkar, Benjamin; Hoggard, Jamin C; Marney, Luke C; Billingsley, Matthew C; Fraga, Carlos G; Bruno, Thomas J; Synovec, Robert E

    2014-01-31

    There is an increased need to more fully assess and control the composition of kerosene-based rocket propulsion fuels such as RP-1. In particular, it is critical to make better quantitative connections among the following three attributes: fuel performance (thermal stability, sooting propensity, engine specific impulse, etc.), fuel properties (such as flash point, density, kinematic viscosity, net heat of combustion, and hydrogen content), and the chemical composition of a given fuel, i.e., amounts of specific chemical compounds and compound classes present in a fuel as a result of feedstock blending and/or processing. Recent efforts in predicting fuel chemical and physical behavior through modeling put greater emphasis on attaining detailed and accurate fuel properties and fuel composition information. Often, one-dimensional gas chromatography (GC) combined with mass spectrometry (MS) is employed to provide chemical composition information. Building on approaches that used GC-MS, but to glean substantially more chemical information from these complex fuels, we recently studied the use of comprehensive two dimensional (2D) gas chromatography combined with time-of-flight mass spectrometry (GC×GC-TOFMS) using a "reversed column" format: RTX-wax column for the first dimension, and a RTX-1 column for the second dimension. In this report, by applying chemometric data analysis, specifically partial least-squares (PLS) regression analysis, we are able to readily model (and correlate) the chemical compositional information provided by use of GC×GC-TOFMS to RP-1 fuel property information such as density, kinematic viscosity, net heat of combustion, and so on. Furthermore, we readily identified compounds that contribute significantly to measured differences in fuel properties based on results from the PLS models. We anticipate this new chemical analysis strategy will have broad implications for the development of high fidelity composition-property models, leading to an

  3. On the accuracy of protein determination in large biological samples by prompt gamma neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kasviki, K. [Institute of Nuclear Technology and Radiation Protection, NCSR ' Demokritos' , Aghia Paraskevi, Attikis 15310 (Greece); Medical Physics Laboratory, Medical School, University of Ioannina, Ioannina 45110 (Greece); Stamatelatos, I.E. [Institute of Nuclear Technology and Radiation Protection, NCSR ' Demokritos' , Aghia Paraskevi, Attikis 15310 (Greece)], E-mail: ion@ipta.demokritos.gr; Yannakopoulou, E. [Institute of Physical Chemistry, NCSR ' Demokritos' , Aghia Paraskevi, Attikis 15310 (Greece); Papadopoulou, P. [Institute of Technology of Agricultural Products, NAGREF, Lycovrissi, Attikis 14123 (Greece); Kalef-Ezra, J. [Medical Physics Laboratory, Medical School, University of Ioannina, Ioannina 45110 (Greece)

    2007-10-15

    A prompt gamma neutron activation analysis (PGNAA) facility has been developed for the determination of nitrogen and thus total protein in large volume biological samples or the whole body of small animals. In the present work, the accuracy of nitrogen determination by PGNAA in phantoms of known composition as well as in four raw ground meat samples of about 1 kg mass was examined. Dumas combustion and Kjeldahl techniques were also used for the assessment of nitrogen concentration in the meat samples. No statistically significant differences were found between the concentrations assessed by the three techniques. The results of this work demonstrate the applicability of PGNAA for the assessment of total protein in biological samples of 0.25-1.5 kg mass, such as a meat sample or the body of small animal even in vivo with an equivalent radiation dose of about 40 mSv.

  4. On the accuracy of protein determination in large biological samples by prompt gamma neutron activation analysis

    International Nuclear Information System (INIS)

    Kasviki, K.; Stamatelatos, I.E.; Yannakopoulou, E.; Papadopoulou, P.; Kalef-Ezra, J.

    2007-01-01

    A prompt gamma neutron activation analysis (PGNAA) facility has been developed for the determination of nitrogen and thus total protein in large volume biological samples or the whole body of small animals. In the present work, the accuracy of nitrogen determination by PGNAA in phantoms of known composition as well as in four raw ground meat samples of about 1 kg mass was examined. Dumas combustion and Kjeldahl techniques were also used for the assessment of nitrogen concentration in the meat samples. No statistically significant differences were found between the concentrations assessed by the three techniques. The results of this work demonstrate the applicability of PGNAA for the assessment of total protein in biological samples of 0.25-1.5 kg mass, such as a meat sample or the body of small animal even in vivo with an equivalent radiation dose of about 40 mSv

  5. Iodine intake by adult residents of a farming area in Iwate Prefecture, Japan, and the accuracy of estimated iodine intake calculated using the Standard Tables of Food Composition in Japan.

    Science.gov (United States)

    Nakatsuka, Haruo; Chiba, Keiko; Watanabe, Takao; Sawatari, Hideyuki; Seki, Takako

    2016-11-01

    Iodine intake by adults in farming districts in Northeastern Japan was evaluated by two methods: (1) government-approved food composition tables based calculation and (2) instrumental measurement. The correlation between these two values and a regression model for the calibration of calculated values was presented. Iodine intake was calculated, using the values in the Japan Standard Tables of Food Composition (FCT), through the analysis of duplicate samples of complete 24-h food consumption for 90 adult subjects. In cases where the value for iodine content was not available in the FCT, it was assumed to be zero for that food item (calculated values). Iodine content was also measured by ICP-MS (measured values). Calculated and measured values rendered geometric means (GM) of 336 and 279 μg/day, respectively. There was no statistically significant (p > 0.05) difference between calculated and measured values. The correlation coefficient was 0.646 (p GM, calculated) and 279 μg/day (GM, measured). Both values correlated so well, with a correlation coefficient of 0.646, that a regression model (Y = 130.8 + 1.9479X, where X and Y are measured and calculated values, respectively) could be used to calibrate calculated values.

  6. SEASONAL, SIZE-RELATED AND AGE-RELATED PATTERNS IN BODY-MASS AND COMPOSITION OF PURPLE SANDPIPERS CALIDRIS-MARITIMA IN BRITAIN

    NARCIS (Netherlands)

    SUMMERS, RW; UNDERHILL, LG; NICOLL, M; RAE, R; PIERSMA, T

    1992-01-01

    The masses Of 3229 Purple Sandpipers Calidris maritima from Britain were analysed for differences related to age, season and size. First-year birds were lighter by 2 g. There was only a slight increase in mass in mid-winter, in contrast to other waders wintering in Britain, suggesting that Purple

  7. Fourier Transform Mass Spectrometry

    Science.gov (United States)

    Scigelova, Michaela; Hornshaw, Martin; Giannakopulos, Anastassios; Makarov, Alexander

    2011-01-01

    This article provides an introduction to Fourier transform-based mass spectrometry. The key performance characteristics of Fourier transform-based mass spectrometry, mass accuracy and resolution, are presented in the view of how they impact the interpretation of measurements in proteomic applications. The theory and principles of operation of two types of mass analyzer, Fourier transform ion cyclotron resonance and Orbitrap, are described. Major benefits as well as limitations of Fourier transform-based mass spectrometry technology are discussed in the context of practical sample analysis, and illustrated with examples included as figures in this text and in the accompanying slide set. Comparisons highlighting the performance differences between the two mass analyzers are made where deemed useful in assisting the user with choosing the most appropriate technology for an application. Recent developments of these high-performing mass spectrometers are mentioned to provide a future outlook. PMID:21742802

  8. Meditation experience predicts introspective accuracy.

    Directory of Open Access Journals (Sweden)

    Kieran C R Fox

    Full Text Available The accuracy of subjective reports, especially those involving introspection of one's own internal processes, remains unclear, and research has demonstrated large individual differences in introspective accuracy. It has been hypothesized that introspective accuracy may be heightened in persons who engage in meditation practices, due to the highly introspective nature of such practices. We undertook a preliminary exploration of this hypothesis, examining introspective accuracy in a cross-section of meditation practitioners (1-15,000 hrs experience. Introspective accuracy was assessed by comparing subjective reports of tactile sensitivity for each of 20 body regions during a 'body-scanning' meditation with averaged, objective measures of tactile sensitivity (mean size of body representation area in primary somatosensory cortex; two-point discrimination threshold as reported in prior research. Expert meditators showed significantly better introspective accuracy than novices; overall meditation experience also significantly predicted individual introspective accuracy. These results suggest that long-term meditators provide more accurate introspective reports than novices.

  9. ICP magnetic sector multiple collector mass spectrometry and the precise measurement of isotopic compositions using nebulization of solutions and laser ablation of solids

    International Nuclear Information System (INIS)

    Halliday, A.N.; Lee, D-C.; Christensen, J.N.; Yi, W.; Hall, C.M.; Jones, C.E.; Teagle, D.A.H.; Freedman, P.A.

    1996-01-01

    Inductively-coupled plasma (ICP) sources offer considerable advantages over thermal sources because the high ionization efficiency facilitates measurements of relatively high sensitivity for elements such as Hf or Sn, which can be difficult to measure precisely with thermal ionization mass spectrometry (TIMS). The mass discrimination (bias) is larger than for TIMS, favours the heavier ions, and decreases in magnitude with increasing mass. However, in contrast to TIMS, this discrimination is largely independent of the chemical or physical properties of the element or the duration of the analysis. This has been demonstrated to high precision with a double focussing multiple collector magnetic sector mass spectrometer with an ICP source. The principle of this instrument is briefly described. The potential of the instrument for high precision isotopic measurements of a very broad range of elements, using solution aspiration or laser ablation, is indicated. 15 refs

  10. Mass spectrometry in oceanography

    International Nuclear Information System (INIS)

    Aggarwal, Suresh K.

    2000-01-01

    Mass spectrometry plays an important role in oceanography for various applications. Different types of inorganic as well as organic mass spectrometric techniques are being exploited world-wide to understand the different aspects of marine science, for palaeogeography, palaeoclimatology and palaeoecology, for isotopic composition and concentrations of different elements as well as for speciation studies. The present paper reviews some of the applications of atomic mass spectrometric techniques in the area of oceanography

  11. Mixing of water masses caused by a drifting iceberg affects bacterial activity, community composition and substrate utilization capability in the Southern Ocean.

    Science.gov (United States)

    Dinasquet, Julie; Richert, Inga; Logares, Ramiro; Yager, Patricia; Bertilsson, Stefan; Riemann, Lasse

    2017-06-01

    The number of icebergs produced from ice-shelf disintegration has increased over the past decade in Antarctica. These drifting icebergs mix the water column, influence stratification and nutrient condition, and can affect local productivity and food web composition. Data on whether icebergs affect bacterioplankton function and composition are scarce, however. We assessed the influence of iceberg drift on bacterial community composition and on their ability to exploit carbon substrates during summer in the coastal Southern Ocean. An elevated bacterial production and a different community composition were observed in iceberg-influenced waters relative to the undisturbed water column nearby. These major differences were confirmed in short-term incubations with bromodeoxyuridine followed by CARD-FISH. Furthermore, one-week bottle incubations amended with inorganic nutrients and carbon substrates (a mix of substrates, glutamine, N-acetylglucosamine, or pyruvate) revealed contrasting capacity of bacterioplankton to utilize specific carbon substrates in the iceberg-influenced waters compared with the undisturbed site. Our study demonstrates that the hydrographical perturbations introduced by a drifting iceberg can affect activity, composition, and substrate utilization capability of marine bacterioplankton. Consequently, in a context of global warming, increased frequency of drifting icebergs in polar regions holds the potential to affect carbon and nutrient biogeochemistry at local and possibly regional scales. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  12. Mass of the photon

    International Nuclear Information System (INIS)

    Goldhaber, A.S.; Nieto, M.M.

    1976-01-01

    Several experiments are discussed for which results are equivalent to the catching and weighing of a photon. It is noted that none of the experiments has proved the rest mass to be zero and that such a proof may be impossible. It is shown by such experiments that the rest mass is less than the limit of accuracy of the experiment. These limits have approached ever closer to zero, and the most recent values are exceedingly small

  13. Bayesian Integration and Characterization of Composition C-4 Plastic Explosives Based on Time-of-Flight Secondary Ion Mass Spectrometry and Laser Ablation-Inductively Coupled Plasma Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, Christine M.; Kelly, Ryan T.; Alexander, M. L.; Newburn, Matthew K.; Bader, Sydney P.; Ewing, Robert G.; Fahey, Albert J.; Atkinson, David A.; Beagley, Nathaniel

    2016-02-25

    Key elements regarding the use of non-radioactive ionization sources will be presented as related to explosives detection by mass spectrometry and ion mobility spectrometry. Various non-radioactive ionization sources will be discussed along with associated ionization mechanisms pertaining to specific sample types.

  14. Mass Spectrometry Instrumentation in Proteomics

    DEFF Research Database (Denmark)

    Sprenger, Richard Remko; Roepstorff, Peter

    2012-01-01

    Mass spectrometry has evolved into a crucial technology for the field of proteomics, enabling the comprehensive study of proteins in biological systems. Innovative developments have yielded flexible and versatile mass spectrometric tools, including quadrupole time-of-flight, linear ion trap......, Orbitrap and ion mobility instruments. Together they offer various and complementary capabilities in terms of ionization, sensitivity, speed, resolution, mass accuracy, dynamic range and methods of fragmentation. Mass spectrometers can acquire qualitative and quantitative information on a large scale...

  15. Evaluation of clayey masses compositions starting from the residue incorporation of the red ceramic industry to obtain tubular ceramic membranes; Avaliacao das composicoes de massas argilosas a partir da incorporacao de residuo da industria de ceramica vermelha na obtencao de membranas ceramicas tubulares

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Adriano Lima da; Chaves, Alexsandra Cristina; Luna, Carlos Bruno Barreto; Neves, Gelmires de Araujo; Lira, Helio de Lucena, E-mail: adrianolimadasilva@hotmail.com, E-mail: alexsandra.chaves@ifap.edu.br, E-mail: brunobarretodemaufcg@hotmail.com, E-mail: gelmires@ufcg.edu.br, E-mail: helio@ufcg.edu.br [Universidade Federal de Campina Grande (UAEMa/CCT/UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

    2017-01-15

    The inappropriate residue disposal of red ceramic industry is very high. Nowadays, one of the major challenges is the investigation of processes to obtain alternative materials, enabling the use of these residues to manufacture new materials. This work's objective is to study clayey masses' compositions starting from the residue incorporation of the red ceramic industry to be used in tubular ceramic membranes. Two compositions of ceramic masses were established, composition A (50% of residue) and composition B (70% of residue). Granulometric analysis of the ceramic masses presented an average size of particles, what indicates membranes in the microfiltration scale. Another observed factor is related to the increase of residue amount, what favored a decrease in the ceramic mass' plasticity. A rise in the apparent porosity was also observed, probably because of a possible growing in the bigger pores numbers, due to the sintering high temperature and the elevation of residue quantity itself. (author)

  16. Static secondary ion mass spectrometry for organic and inorganic molecular analysis in solids

    International Nuclear Information System (INIS)

    Ham, Rita van; Vaeck, Luc van; Adriaens, Annemie; Adams, Freddy

    2003-01-01

    The use of mass spectra in secondary ion mass spectrometry (S-SIMS) to characterise the molecular composition of inorganic and organic analytes at the surface of solid samples is investigated. Methodological aspects such as mass resolution, mass accuracy, precision and accuracy of isotope abundance measurements, influence of electron flooding and sample morphology are addressed to assess the possibilities and limitations that the methodology can offer to support the structural assignment of the detected ions. The in-sample and between-sample reproducibility of relative peak intensities under optimised conditions is within 10%, but experimental conditions and local hydration, oxidation or contamination can drastically affect the mass spectra. As a result, the use of fingerprinting for identification becomes compromised. Therefore, the preferred way of interpretation becomes the deductive structural approach, based on the use of the empirical desorption-ionisation model. This approach is shown to allow the molecular composition of inorganic and organic components at the surface of solids to be characterised. Examples of inorganic speciation and identification of organic additives with unknown composition in inorganic salt mixtures are given. The methodology is discussed in terms of foreseen developments with respect to the use of polyatomic primary ions

  17. Evaluation of Columbia, USMARC Composite, Suffolk, and Texel rams as terminal sires in an extensive rangeland production system: VII. Accuracy of ultrasound predictors and their association with carcass weight, yield, and value.

    Science.gov (United States)

    Notter, D R; Mousel, M R; Leeds, T D; Zerby, H N; Moeller, S J; Lewis, G S; Taylor, J B

    2014-06-01

    Use of lamb BW or chilled carcass weights (CCW), live-animal ultrasound or direct carcass measurements of backfat thickness (BF; mm) and LM area (LMA; cm(2)), and carcass body wall thickness (BWall; mm) to predict carcass yield and value was evaluated using 512 crossbred lambs produced over 3 yr by mating Columbia, U.S. Meat Animal Research Center Composite, Suffolk, and Texel rams to adult Rambouillet ewes. Lambs were harvested at 3 BW endpoints within each year. The predictive value of 3 to 5 additional linear measurements of live-animal or carcass size and shape was also evaluated. Residual correlations (adjusted for effects of year, breed, and harvest group) between ultrasound and direct measurements were 0.69 for BF and 0.65 for LMA. Increasing ultrasound or carcass LMA had positive effects (P carcass (i.e., on dressing percentage) and, at comparable CCW, on weight of high-value cuts (rack, loin, leg, and sirloin) before trimming (HVW), weight of trimmed high-value cuts (trimmed rack and loin and trimmed boneless leg and sirloin; TrHVW), and carcass value before (CVal) and after (TrCVal) trimming of high-value cuts. By contrast, ultrasound and direct measures of BF had positive effects on yields of CCW and on HVW and CVal but large negative effects on TrHVW and TrCVal. After adjusting for BW at scanning, increases of 1 mm in ultrasound BF or 1 cm(2) in ultrasound LMA were associated with changes of US$-0.32 (P Carcass BWall was generally superior to carcass BF as a predictor of TrHVW and TrCVal. Carcass LMA was superior to ultrasound LMA but carcass BF was inferior to ultrasound BF for prediction of carcass yield and value. Increasing LMA thus would be expected to improve carcass yield and value. Addition of linear measurements of live-animal or carcass size and shape to the prediction model reduced residual SD (RSD) for TrHVW and TrCVal by 0.4 to 2.2%, but subsequent removal of ultrasound or direct measures of BF and LMA from the prediction model increased

  18. Aerosol particle measurements at three stationary sites in the megacity of Paris during summer 2009: meteorology and air mass origin dominate aerosol particle composition and size distribution

    Directory of Open Access Journals (Sweden)

    F. Freutel

    2013-01-01

    Full Text Available During July 2009, a one-month measurement campaign was performed in the megacity of Paris. Amongst other measurement platforms, three stationary sites distributed over an area of 40 km in diameter in the greater Paris region enabled a detailed characterization of the aerosol particle and gas phase. Simulation results from the FLEXPART dispersion model were used to distinguish between different types of air masses sampled. It was found that the origin of air masses had a large influence on measured mass concentrations of the secondary species particulate sulphate, nitrate, ammonium, and oxygenated organic aerosol measured with the Aerodyne aerosol mass spectrometer in the submicron particle size range: particularly high concentrations of these species (about 4 μg m−3, 2 μg m−3, 2 μg m−3, and 7 μg m−3, respectively were measured when aged material was advected from continental Europe, while for air masses originating from the Atlantic, much lower mass concentrations of these species were observed (about 1 μg m−3, 0.2 μg m−3, 0.4 μg m−3, and 1–3 μg m−3, respectively. For the primary emission tracers hydrocarbon-like organic aerosol, black carbon, and NOx it was found that apart from diurnal source strength variations and proximity to emission sources, local meteorology had the largest influence on measured concentrations, with higher wind speeds leading to larger dilution and therefore smaller measured concentrations. Also the shape of particle size distributions was affected by wind speed and air mass origin. Quasi-Lagrangian measurements performed under connected flow conditions between the three stationary sites were used to estimate the influence of the Paris emission plume onto its surroundings, which was found to be rather small. Rough estimates for the impact of the Paris emission plume on the suburban areas can be

  19. Weight Loss Composition is One-Fourth Fat-Free Mass: A Critical Review and Critique of This Widely Cited Rule

    Science.gov (United States)

    Heymsfield, Steven B.; Cristina Gonzalez, M. C.; Shen, Wei; Redman, Leanne; Thomas, Diana

    2014-01-01

    Maximizing fat loss while preserving lean tissue mass and function is a central goal of modern obesity treatments. A widely cited rule guiding expected loss of lean tissue as fat-free mass (FFM) states that approximately one-fourth of weight loss will be FFM (i.e., ΔFFM/ΔWeight = ~0.25) with the remaining three-fourths fat mass. This review examines the dynamic relations between FFM, fat mass, and weight changes that follow induction of negative energy balance with hypocaloric dieting and/or exercise. Historical developments in the field are traced with the “Quarter FFM Rule” used as a framework to examine evolving concepts on obesity tissue, excess weight, and what is often cited as “Forbes’ Rule”. Temporal effects in the fractional contribution of FFM to changes in body weight are examined as are lean tissue moderating effects such as aging, inactivity, and exercise that frequently accompany structured low-calorie diet weight loss protocols. Losses of lean tissue with dieting typically tend to be small, raising questions about study design, power, and applied measurement method reliability. Our review elicits important questions related to the fractional loss of lean tissues with dieting and provides a foundation for future research on this topic. PMID:24447775

  20. Effect of temperature and solvent composition on acid dissociation equilibria, I: Sequenced sspKa determination of compounds commonly used as buffers in high performance liquid chromatography coupled to mass spectroscopy detection

    International Nuclear Information System (INIS)

    Padró, Juan M.; Acquaviva, Agustín; Tascon, Marcos; Gagliardi, Leonardo G.; Castells, Cecilia B.

    2012-01-01

    Highlights: ► We developed a rapid potentiometric method for sequential pK a determinations. ► We measured pK a of buffers from 0 to 90% (v/v) acetonitrile/water and from 20 to 60 °C. ► Sequences of 42 pK a -data spanned over a wide solvent composition range needed 2 h. ► We measured pK a of formic acid and triethylamine/HCl in up to 90% (v/v) acetonitrile. ► The high-throughput method was applied to obtain pK a of two common buffers in LC/MS. - Abstract: A new automated and rapid potentiometric method for determining the effect of organic-solvent composition on pK a has been developed. It is based on the measurements of pH values of buffer solutions of variable solvent compositions using a combined glass electrode. Additions of small volumes of one precisely thermostated solution into another, both containing exactly the same analytical concentrations of the buffer components, can produce continuous changes in the solvent composition. Two sequences of potential measurements, one of increasing and the other of decreasing solvent content, are sufficient to obtain the pK a values of the acidic compound within the complete solvent-composition range in about 2 h. The experimental design, procedures, and calculations needed to convert the measured pH into the thermodynamic pK a values are thoroughly discussed. This rapid and automated method allows the systematic study of the effect of solvent compositions and temperatures on the pK a . It has been applied to study the dissociation constants of two monoprotic acids: formic acid and triethylamine:HCl in acetonitrile/water mixtures within the range from 0 to 90% (v/v) at temperatures between 20 °C and 60 °C. These volatile compounds are frequently used to control the pH of the mobile phase in HPLC, especially in methods coupled to mass-spectrometry detection. The obtained pK a values are in excellent agreement with those previously reported. The results were fitted to empirical functions between pK a and

  1. Effect of temperature and solvent composition on acid dissociation equilibria, I: Sequenced {sup s}{sub s}pK{sub a} determination of compounds commonly used as buffers in high performance liquid chromatography coupled to mass spectroscopy detection

    Energy Technology Data Exchange (ETDEWEB)

    Padro, Juan M.; Acquaviva, Agustin; Tascon, Marcos [Laboratorio de Separaciones Analiticas, Division Quimica Analitica, Universidad Nacional de La Plata y CIDEPINT, 47 y 115, (1900) La Plata (Argentina); Gagliardi, Leonardo G., E-mail: leogagliardi@quimica.unlp.edu.ar [Laboratorio de Separaciones Analiticas, Division Quimica Analitica, Universidad Nacional de La Plata y CIDEPINT, 47 y 115, (1900) La Plata (Argentina); Castells, Cecilia B., E-mail: castells@isis.unlp.edu.ar [Laboratorio de Separaciones Analiticas, Division Quimica Analitica, Universidad Nacional de La Plata y CIDEPINT, 47 y 115, (1900) La Plata (Argentina)

    2012-05-06

    methods coupled to mass-spectrometry detection. The obtained pK{sub a} values are in excellent agreement with those previously reported. The results were fitted to empirical functions between pK{sub a} and temperature and composition. These equations, which can be used to estimate the pK{sub a} of these substances at any composition and temperature, would be highly useful in practical work during chromatographic method development.

  2. Transport Regimes of Air Masses Affecting the Tropospheric Composition of the Canadian and European Arctic During RACEPAC 2014 and NETCARE 2014/2015

    Science.gov (United States)

    Bozem, H.; Hoor, P. M.; Koellner, F.; Kunkel, D.; Schneider, J.; Schulz, C.; Herber, A. B.; Borrmann, S.; Wendisch, M.; Ehrlich, A.; Leaitch, W. R.; Willis, M. D.; Burkart, J.; Thomas, J. L.; Abbatt, J.

    2015-12-01

    The Arctic is warming much faster than any other place in the world and undergoes a rapid change dominated by a changing climate in this region. The impact of polluted air masses traveling to the Arctic from various remote sources significantly contributes to the observed climate change, in contrast there are additional local emission sources contributing to the level of pollutants (trace gases and aerosol). Processes affecting the emission and transport of these pollutants are not well understood and need to be further investigated. We present aircraft based trace gas measurements in the Arctic during RACEPAC (2014) and NETCARE (2014 and 2015) with the Polar 6 aircraft of Alfred Wegener Institute (AWI) covering an area from 134°W to 17°W and 68°N to 83°N. We focus on cloud, aerosol and general transport processes of polluted air masses into the high Arctic. Based on CO and CO2 measurements and kinematic 10-day back trajectories we analyze the transport regimes prevalent during spring (RACEPAC 2014 and NETCARE 2015) and summer (NETCARE 2014) in the observed region. Whereas the eastern part of the Canadian Arctic is affected by air masses with their origin in Asia, in the central and western parts of the Canadian and European Arctic air masses from North America are predominant at the time of the measurement. In general the more northern parts of the Arctic were relatively unaffected by pollution from mid-latitudes since air masses mostly travel within the polar dome, being quite isolated. Associated mixing ratios of CO and CO2 fit into the seasonal cycle observed at NOAA ground stations throughout the Arctic, but show a more mid-latitudinal characteristic at higher altitudes. The transition is remarkably sharp and allows for a chemical definition of the polar dome. At low altitudes, synoptic disturbances transport polluted air masses from mid-latitudes into regions of the polar dome. These air masses contribute to the Arctic pollution background, but also

  3. Test Expectancy Affects Metacomprehension Accuracy

    Science.gov (United States)

    Thiede, Keith W.; Wiley, Jennifer; Griffin, Thomas D.

    2011-01-01

    Background: Theory suggests that the accuracy of metacognitive monitoring is affected by the cues used to judge learning. Researchers have improved monitoring accuracy by directing attention to more appropriate cues; however, this is the first study to more directly point students to more appropriate cues using instructions regarding tests and…

  4. PM2.5 Chemical Composition at a Rural Background Site in Central Europe, Including Correlation and Air Mass Back Trajectory Analysis.

    Czech Academy of Sciences Publication Activity Database

    Schwarz, Jaroslav; Cusack, Michael; Karban, Jindřich; Chalupníčková, E.; Havránek, Vladimír; Smolík, Jiří; Ždímal, Vladimír

    176-177, JUL 1 (2016), s. 108-120 ISSN 0169-8095 R&D Projects: GA ČR(CZ) GAP209/11/1342; GA MŠk(CZ) LM2011019 EU Projects: European Commission(XE) 262254 - ACTRIS Institutional support: RVO:67985858 ; RVO:61389005 Keywords : rural aerosol * PM2.5 * chemical composition Subject RIV: CF - Physical ; Theoretical Chemistry; BG - Nuclear, Atomic and Molecular Physics, Colliders (UJF-V) Impact factor: 3.778, year: 2016

  5. Body mass composition of ballet dancers and elite female aesthetic sport athletes from Cuba. DOI: 10.5007/1980-0037.2011v13n5p335

    OpenAIRE

    Hamlet Betancout León; Oscar Salinas Flores; Julieta Aréchiga Viramontes

    2011-01-01

    The level of scenic beauty of ballet dancer’s figure is signified for the reason of possessing morpho-functional characteristics valid only within the artistic cannon. The female ballet dancers and the sportswomen who practice esthetic sports do have in common the need of being slim and executing efficiently the complex movements of their technical activities. The objective of this paper is to compare the body composition of ballet female dancers with that of the artistic gymnastics (GAR), th...

  6. Accuracy of physical self-description among chronic exercisers and non-exercisers

    Directory of Open Access Journals (Sweden)

    Joseph M. Berning

    2014-10-01

    Full Text Available This study addressed the role of chronic exercise to enhance physical self-description as measured by self-estimated percent body fat. Accuracy of physical self-description was determined in normal-weight, regularly exercising and non-exercising males with similar body mass index (BMI’s and females with similar BMI’s (n=42 males and 45 females of which 23 males and 23 females met criteria to be considered chronic exercisers. Statistical analyses were conducted to determine the degree of agreement between self-estimated percent body fat and actual laboratory measurements (hydrostatic weighing. Three statistical techniques were employed: Pearson correlation coefficients, Bland and Altman plots, and regression analysis. Agreement between measured and self-estimated percent body fat was superior for males and females who exercised chronically, compared to non-exercisers. The clinical implications are as follows. Satisfaction with one’s body can be influenced by several factors, including self-perceived body composition. Dissatisfaction can contribute to maladaptive and destructive weight management behaviors. The present study suggests that regular exercise provides a basis for more positive weight management behaviors by enhancing the accuracy of self-assessed body composition.

  7. Required experimental accuracy to select between supersymmetrical models

    Science.gov (United States)

    Grellscheid, David

    2004-03-01

    We will present a method to decide a priori whether various supersymmetrical scenarios can be distinguished based on sparticle mass data alone. For each model, a scan over all free SUSY breaking parameters reveals the extent of that model's physically allowed region of sparticle-mass-space. Based on the geometrical configuration of these regions in mass-space, it is possible to obtain an estimate of the required accuracy of future sparticle mass measurements to distinguish between the models. We will illustrate this algorithm with an example. This talk is based on work done in collaboration with B C Allanach (LAPTH, Annecy) and F Quevedo (DAMTP, Cambridge).

  8. VizieR Online Data Catalog: Atomic mass excesses (Schatz+, 2017)

    Science.gov (United States)

    Schatz, H.; Ong, W.-J.

    2018-03-01

    X-ray burst model predictions of light curves and the final composition of the nuclear ashes are affected by uncertain nuclear masses. However, not all of these masses are determined experimentally with sufficient accuracy. Here we identify the remaining nuclear mass uncertainties in X-ray burst models using a one-zone model that takes into account the changes in temperature and density evolution caused by changes in the nuclear physics. Two types of bursts are investigated-a typical mixed H/He burst with a limited rapid proton capture process (rp-process) and an extreme mixed H/He burst with an extended rp-process. When allowing for a 3σ variation, only three remaining nuclear mass uncertainties affect the light-curve predictions of a typical H/He burst (27P, 61Ga, and 65As), and only three additional masses affect the composition strongly (80Zr, 81Zr, and 82Nb). A larger number of mass uncertainties remain to be addressed for the extreme H/He burst, with the most important being 58Zn, 61Ga, 62Ge, 65As, 66Se, 78Y, 79Y, 79Zr, 80Zr, 81Zr, 82Zr, 82Nb, 83Nb, 86Tc, 91Rh, 95Ag, 98Cd, 99In, 100In, and 101In. The smallest mass uncertainty that still impacts composition significantly when varied by 3σ is 85Mo with 16keV uncertainty. For one of the identified masses, 27P, we use the isobaric mass multiplet equation to improve the mass uncertainty, obtaining an atomic mass excess of -716(7)keV. The results provide a roadmap for future experiments at advanced rare isotope beam facilities, where all the identified nuclides are expected to be within reach for precision mass measurements. (1 data file).

  9. Miniature mass analyzer

    CERN Document Server

    Cuna, C; Lupsa, N; Cuna, S; Tuzson, B

    2003-01-01

    The paper presents the concept of different mass analyzers that were specifically designed as small dimension instruments able to detect with great sensitivity and accuracy the main environmental pollutants. The mass spectrometers are very suited instrument for chemical and isotopic analysis, needed in environmental surveillance. Usually, this is done by sampling the soil, air or water followed by laboratory analysis. To avoid drawbacks caused by sample alteration during the sampling process and transport, the 'in situ' analysis is preferred. Theoretically, any type of mass analyzer can be miniaturized, but some are more appropriate than others. Quadrupole mass filter and trap, magnetic sector, time-of-flight and ion cyclotron mass analyzers can be successfully shrunk, for each of them some performances being sacrificed but we must know which parameters are necessary to be kept unchanged. To satisfy the miniaturization criteria of the analyzer, it is necessary to use asymmetrical geometries, with ion beam obl...

  10. Top Quark Mass

    CERN Document Server

    Mulders, Martijn

    2016-01-01

    Ever since the discovery of the top quark at the Tevatron collider in 1995 the measurement of its mass has been a high priority. As one of the fundamental parameters of the Standard Theory of particle physics, the precise value of the top quark mass together with other inputs provides a test for the self-consistency of the theory, and has consequences for the stability of the Higgs field that permeates the Universe. In this review I will briefly summarize the experimental techniques used at the Tevatron and the LHC experiments throughout the years to measure the top quark mass with ever improving accuracy, and highlight the recent progress in combining all measurements in a single world average combination. As experimental measurements became more precise, the question of their theoretical interpretation has become important. The difficulty of relating the measured quantity to the fundamental top mass parameter has inspired alternative measurement methods that extract the top mass in complementary ways. I wil...

  11. Protein Analysis by Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Cindic, M.

    2008-04-01

    Full Text Available Soft ionization techniques, electrospray (ESI and matrix-assisted laser desorption/ionization (MALDI make the analysis of biomolecules by mass spectrometry (MS possible. MS is used for determination of the molecular weight of peptides and protein, sequence analysis, characterization of protein-ligand interactions etc. The detection limit, resolution and mass accuracy depend on instrument used (Table 1. Impurities (buffers, salts, detergents can reduce the ion intensities or even totally suppress them, so a separation method (chromatography, 2D-gel electrophoresis must be used for purification of the sample.Molecular mass of intact protein can be determined by ESI or MALDI MS. Multiply charged ions are produced by ESI MS, while singly charged ions are predominant in MALDI spectra (Fig. 2.Sequence analysis of proteins by MS can be performed using peptide mass fingerprint. In this method, proteins are separated by 2-D gel electrophoresis and digested with specific protease (Table 2 or digested and then separated by two-dimensional chromatography (Fig. 1. The obtained peptide mixtures are analyzed by MS or MALDI-TOF technique. The masses determined by MS are compared with calculated masses from database entries. Different algorithms have been developed for protein identification. Example of posttranslational modifications (N- and O-glycosylation and protein sequence complex analysis after dual digestion (endoproteinase digestion followed by endoglycosidase digestion is shown in Fig. 3.It is known that detection of peptides by MS is influenced by intrinsic properties like amino acid composition, the basicity of the C-terminal amino acid, hydrophobicity, etc. Arginine-containing peptides dominate in MS spectra of tryptic digest, so the chemical derivatization of lysine terminal residue by O-methilisourea or 2-methoxy-4,5-1H-imidazole was suggested (Fig. 4.The peptide mass fingerprint method can be improved further by peptide fragmentation using tandem

  12. Test expectancy affects metacomprehension accuracy.

    Science.gov (United States)

    Thiede, Keith W; Wiley, Jennifer; Griffin, Thomas D

    2011-06-01

    Theory suggests that the accuracy of metacognitive monitoring is affected by the cues used to judge learning. Researchers have improved monitoring accuracy by directing attention to more appropriate cues; however, this is the first study to more directly point students to more appropriate cues using instructions regarding tests and practice tests. The purpose of the present study was to examine whether the accuracy metacognitive monitoring was affected by the nature of the test expected. Students (N= 59) were randomly assigned to one of two test expectancy groups (memory vs. inference). Then after reading texts, judging learning, completed both memory and inference tests. Test performance and monitoring accuracy were superior when students received the kind of test they had been led to expect rather than the unexpected test. Tests influence students' perceptions of what constitutes learning. Our findings suggest that this could affect how students prepare for tests and how they monitoring their own learning. ©2010 The British Psychological Society.

  13. Forecast Accuracy Uncertainty and Momentum

    OpenAIRE

    Bing Han; Dong Hong; Mitch Warachka

    2009-01-01

    We demonstrate that stock price momentum and earnings momentum can result from uncertainty surrounding the accuracy of cash flow forecasts. Our model has multiple information sources issuing cash flow forecasts for a stock. The investor combines these forecasts into an aggregate cash flow estimate that has minimal mean-squared forecast error. This aggregate estimate weights each cash flow forecast by the estimated accuracy of its issuer, which is obtained from their past forecast errors. Mome...

  14. Social Power Increases Interoceptive Accuracy

    Directory of Open Access Journals (Sweden)

    Mehrad Moeini-Jazani

    2017-08-01

    Full Text Available Building on recent psychological research showing that power increases self-focused attention, we propose that having power increases accuracy in perception of bodily signals, a phenomenon known as interoceptive accuracy. Consistent with our proposition, participants in a high-power experimental condition outperformed those in the control and low-power conditions in the Schandry heartbeat-detection task. We demonstrate that the effect of power on interoceptive accuracy is not explained by participants’ physiological arousal, affective state, or general intention for accuracy. Rather, consistent with our reasoning that experiencing power shifts attentional resources inward, we show that the effect of power on interoceptive accuracy is dependent on individuals’ chronic tendency to focus on their internal sensations. Moreover, we demonstrate that individuals’ chronic sense of power also predicts interoceptive accuracy similar to, and independent of, how their situationally induced feeling of power does. We therefore provide further support on the relation between power and enhanced perception of bodily signals. Our findings offer a novel perspective–a psychophysiological account–on how power might affect judgments and behavior. We highlight and discuss some of these intriguing possibilities for future research.

  15. Short Communication: Evaluation of the chemical composition of essential oil of Thuja occidentalis leaves grown in Peshawar, Pakistan by gas chromatography mass spectrometry.

    Science.gov (United States)

    Qureshi, Muhammad Nasimullah; Siddique, Muhammad; Rahman, Inayat-Ur; Kanwal, Farina

    2016-11-01

    Essential oil extracted from the fresh leaves of Thuja occidentalis were evaluated for its chemical composition employing GC-MS. Total of twenty nine components were identified and determined quantitatively using the area normalization procedure. Alpha-pinene and (+)-4-carene were found in high amount with a percentage concentration of 54.78 and 11.28 respectively. Other compounds which yielded appreciable amounts are: alpha-cedrol (6.87%), terpinolene (5.88%), p-menth-1-en-8-ol acetate (5.21%), beta-myrcene (4.04%), beta-pinene (2.26%), germacrene D (1.72%), sabinene (1.65%) and D-Limonene (1.62%).

  16. Dependence of X-Ray Burst Models on Nuclear Masses

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, H.; Ong, W.-J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States)

    2017-08-01

    X-ray burst model predictions of light curves and the final composition of the nuclear ashes are affected by uncertain nuclear masses. However, not all of these masses are determined experimentally with sufficient accuracy. Here we identify the remaining nuclear mass uncertainties in X-ray burst models using a one-zone model that takes into account the changes in temperature and density evolution caused by changes in the nuclear physics. Two types of bursts are investigated—a typical mixed H/He burst with a limited rapid proton capture process (rp-process) and an extreme mixed H/He burst with an extended rp-process. When allowing for a 3 σ variation, only three remaining nuclear mass uncertainties affect the light-curve predictions of a typical H/He burst ({sup 27}P, {sup 61}Ga, and {sup 65}As), and only three additional masses affect the composition strongly ({sup 80}Zr, {sup 81}Zr, and {sup 82}Nb). A larger number of mass uncertainties remain to be addressed for the extreme H/He burst, with the most important being {sup 58}Zn, {sup 61}Ga, {sup 62}Ge, {sup 65}As, {sup 66}Se, {sup 78}Y, {sup 79}Y, {sup 79}Zr, {sup 80}Zr, {sup 81}Zr, {sup 82}Zr, {sup 82}Nb, {sup 83}Nb, {sup 86}Tc, {sup 91}Rh, {sup 95}Ag, {sup 98}Cd, {sup 99}In, {sup 100}In, and {sup 101}In. The smallest mass uncertainty that still impacts composition significantly when varied by 3 σ is {sup 85}Mo with 16 keV uncertainty. For one of the identified masses, {sup 27}P, we use the isobaric mass multiplet equation to improve the mass uncertainty, obtaining an atomic mass excess of −716(7) keV. The results provide a roadmap for future experiments at advanced rare isotope beam facilities, where all the identified nuclides are expected to be within reach for precision mass measurements.

  17. Mass concentration, optical depth and carbon composition of particulate matter in the major southern West African cities of Cotonou (Benin) and Abidjan (Côte d'Ivoire)

    Science.gov (United States)

    Djossou, Julien; Léon, Jean-François; Barthélemy Akpo, Aristide; Liousse, Cathy; Yoboué, Véronique; Bedou, Mouhamadou; Bodjrenou, Marleine; Chiron, Christelle; Galy-Lacaux, Corinne; Gardrat, Eric; Abbey, Marcellin; Keita, Sékou; Bahino, Julien; Touré N'Datchoh, Evelyne; Ossohou, Money; Awanou, Cossi Norbert

    2018-05-01

    Air quality degradation is a major issue in the large conurbations on the shore of the Gulf of Guinea. We present for the first time PM2.5 time series collected in Cotonou, Benin, and Abidjan, Côte d'Ivoire, from February 2015 to March 2017. Measurements were performed in the vicinity of major combustion aerosol sources: Cotonou/traffic (CT), Abidjan/traffic (AT), Abidjan/landfill (AL) and Abidjan/domestic fires (ADF). We report the weekly PM2.5 mass and carbonaceous content as elemental (EC) and organic (OC) carbon concentrations. We also measure the aerosol optical depth (AOD) and the Ångström exponent in both cities. The average PM2.5 mass concentrations were 32 ± 32, 32 ± 24 and 28 ± 19 µg m-3 at traffic sites CT and AT and landfill site AL, respectively. The domestic fire site shows a concentration of 145 ± 69 µg m-3 due to the contribution of smoking and roasting activities. The highest OC and EC concentrations were also measured at ADF at 71 ± 29 and 15 ± 9 µg m-3, respectively, while the other sites present OC concentration between 8 and 12 µg m-3 and EC concentrations between 2 and 7 µg m-3. The OC / EC ratio is 4.3 at CT and 2.0 at AT. This difference highlights the influence of two-wheel vehicles using gasoline in Cotonou compared to that of four-wheel vehicles using diesel fuel in Abidjan. AOD was rather similar in both cities, with a mean value of 0.58 in Cotonou and of 0.68 in Abidjan. The seasonal cycle is dominated by the large increase in surface mass concentration and AOD during the long dry season (December-February) as expected due to mineral dust advection and biomass burning activities. The lowest concentrations are observed during the short dry season (August-September) due to an increase in surface wind speed leading to a better ventilation. On the other hand, the high PM2.5 / AOD ratio in the short wet season (October-November) indicates the stagnation of local pollution.

  18. Mass concentration, optical depth and carbon composition of particulate matter in the major southern West African cities of Cotonou (Benin and Abidjan (Côte d'Ivoire

    Directory of Open Access Journals (Sweden)

    J. Djossou

    2018-05-01

    Full Text Available Air quality degradation is a major issue in the large conurbations on the shore of the Gulf of Guinea. We present for the first time PM2.5 time series collected in Cotonou, Benin, and Abidjan, Côte d'Ivoire, from February 2015 to March 2017. Measurements were performed in the vicinity of major combustion aerosol sources: Cotonou/traffic (CT, Abidjan/traffic (AT, Abidjan/landfill (AL and Abidjan/domestic fires (ADF. We report the weekly PM2.5 mass and carbonaceous content as elemental (EC and organic (OC carbon concentrations. We also measure the aerosol optical depth (AOD and the Ångström exponent in both cities. The average PM2.5 mass concentrations were 32 ± 32, 32 ± 24 and 28 ± 19 µg m−3 at traffic sites CT and AT and landfill site AL, respectively. The domestic fire site shows a concentration of 145 ± 69 µg m−3 due to the contribution of smoking and roasting activities. The highest OC and EC concentrations were also measured at ADF at 71 ± 29 and 15 ± 9 µg m−3, respectively, while the other sites present OC concentration between 8 and 12 µg m−3 and EC concentrations between 2 and 7 µg m−3. The OC ∕ EC ratio is 4.3 at CT and 2.0 at AT. This difference highlights the influence of two-wheel vehicles using gasoline in Cotonou compared to that of four-wheel vehicles using diesel fuel in Abidjan. AOD was rather similar in both cities, with a mean value of 0.58 in Cotonou and of 0.68 in Abidjan. The seasonal cycle is dominated by the large increase in surface mass concentration and AOD during the long dry season (December–February as expected due to mineral dust advection and biomass burning activities. The lowest concentrations are observed during the short dry season (August–September due to an increase in surface wind speed leading to a better ventilation. On the other hand, the high PM2.5 ∕ AOD ratio in the short wet season (October–November indicates the

  19. Trait Perception Accuracy and Acquaintance Within Groups: Tracking Accuracy Development.

    Science.gov (United States)

    Brown, Jill A; Bernieri, Frank

    2017-05-01

    Previous work on trait perception has evaluated accuracy at discrete stages of relationships (e.g., strangers, best friends). A relatively limited body of literature has investigated changes in accuracy as acquaintance within a dyad or group increases. Small groups of initially unacquainted individuals spent more than 30 hr participating in a wide range of activities designed to represent common interpersonal contexts (e.g., eating, traveling). We calculated how accurately each participant judged others in their group on the big five traits across three distinct points within the acquaintance process: zero acquaintance, after a getting-to-know-you conversation, and after 10 weeks of interaction and activity. Judgments of all five traits exhibited accuracy above chance levels after 10 weeks. An examination of the trait rating stability revealed that much of the revision in judgments occurred not over the course of the 10-week relationship as suspected, but between zero acquaintance and the getting-to-know-you conversation.

  20. Analysis of hard protein corona composition on selective iron oxide nanoparticles by MALDI-TOF mass spectrometry: identification and amplification of a hidden mastitis biomarker in milk proteome.

    Science.gov (United States)

    Magro, Massimiliano; Zaccarin, Mattia; Miotto, Giovanni; Da Dalt, Laura; Baratella, Davide; Fariselli, Piero; Gabai, Gianfranco; Vianello, Fabio

    2018-05-01

    Surface active maghemite nanoparticles (SAMNs) are able to recognize and bind selected proteins in complex biological systems, forming a hard protein corona. Upon a 5-min incubation in bovine whey from mastitis-affected cows, a significant enrichment of a single peptide characterized by a molecular weight at 4338 Da originated from the proteolysis of a S1 -casein was observed. Notably, among the large number of macromolecules in bovine milk, the detection of this specific peptide can hardly be accomplished by conventional analytical techniques. The selective formation of a stable binding between the peptide and SAMNs is due to the stability gained by adsorption-induced surface restructuration of the nanomaterial. We attributed the surface recognition properties of SAMNs to the chelation of iron(III) sites on their surface by sterically compatible carboxylic groups of the peptide. The specific peptide recognition by SAMNs allows its easy determination by MALDI-TOF mass spectrometry, and a threshold value of its normalized peak intensity was identified by a logistic regression approach and suggested for the rapid diagnosis of the pathology. Thus, the present report proposes the analysis of hard protein corona on nanomaterials as a perspective for developing fast analytical procedures for the diagnosis of mastitis in cows. Moreover, the huge simplification of proteome complexity by exploiting the selectivity derived by the peculiar SAMN surface topography, due to the iron(III) distribution pattern, could be of general interest, leading to competitive applications in food science and in biomedicine, allowing the rapid determination of hidden biomarkers by a cutting edge diagnostic strategy. Graphical abstract The topography of iron(III) sites on surface active maghemite nanoparticles (SAMNs) allows the recognition of sterically compatible carboxylic groups on proteins and peptides in complex biological matrixes. The analysis of hard protein corona on SAMNs led to the

  1. A structural framework for a near-minimal form of life: mass and compositional analysis of the helical mollicute Spiroplasma melliferum BC3.

    Directory of Open Access Journals (Sweden)

    Shlomo Trachtenberg

    Full Text Available Spiroplasma melliferum is a wall-less bacterium with dynamic helical geometry. This organism is geometrically well defined and internally well ordered, and has an exceedingly small genome. Individual cells are chemotactic, polar, and swim actively. Their dynamic helicity can be traced at the molecular level to a highly ordered linear motor (composed essentially of the proteins fib and MreB that is positioned on a defined helical line along the internal face of the cell's membrane. Using an array of complementary, informationally overlapping approaches, we have taken advantage of this uniquely simple, near-minimal life-form and its helical geometry to analyze the copy numbers of Spiroplasma's essential parts, as well as to elucidate how these components are spatially organized to subserve the whole living cell. Scanning transmission electron microscopy (STEM was used to measure the mass-per-length and mass-per-area of whole cells, membrane fractions, intact cytoskeletons and cytoskeletal components. These local data were fit into whole-cell geometric parameters determined by a variety of light microscopy modalities. Hydrodynamic data obtained by analytical ultracentrifugation allowed computation of the hydration state of whole living cells, for which the relative amounts of protein, lipid, carbohydrate, DNA, and RNA were also estimated analytically. Finally, ribosome and RNA content, genome size and gene expression were also estimated (using stereology, spectroscopy and 2D-gel analysis, respectively. Taken together, the results provide a general framework for a minimal inventory and arrangement of the major cellular components needed to support life.

  2. Independent and combined influence of the FTO rs9939609 and MC4Rrs17782313 polymorphisms on hypocaloric diet induced changes in body mass and composition and energy metabolism in non-morbid obese premenopausal women.

    Science.gov (United States)

    Labayen, Idoia; Margareto, Javier; Maldonado-Martin, Sara; Gorostegi, Ilargi; Illera, Maitane; Medrano, María; Barrenechea, Lurdes; Larrarte, Eider

    2015-05-01

    To examine the independent and combined influence of the FTOrs9939609 and the MC4Rrs17782313 polymorphisms on changes in fat mass (FM), resting energy expenditure (REE), leptin, and thyrotropin (TSH) levels, after a 12-week energy-restricted diet intervention in non-morbid premenopausal obese women. Fat mass (dual X-ray absorptiometry), REE (indirect calorimetry) and plasma leptin and thyrotropin levels were measured (before and after the intervention) in 77 obese (BMI: 33.9 ± 2.8 kg/m(2)) women (age: 36.8 ± 7.0y). There were no significant differences across FTOrs9939609 genotype groups (TT vs. A allele carriers, Ps>0.1) on changes in body mass (-8.6 ± 3.2% vs. -8.7 ± 3.3 %), FM (12.8 ± 4.7% vs. -12.9 ± 6.3%), REE (-11.3 ± 4.7 vs. -9.4 ± 8.1%), leptin (-34.1 ± 25.1% vs. -43.5 ± 24.1%) or TSH (5.2 ± 34.5% vs. -1.7 ± 27.1%) levels. Moreover, it was not observed any significant difference on changes in body mass (-8.6 ± 3.6% vs. -8.9 ± 2.6%), FM (-12.7 ± 6.1% vs. -13.4 ± 5.3%), REE (-9.8 ± 7.4% -9.4 ± 9.4%), leptin (-39.0 ± 26.9% vs. -44.8 ± 18.4%) or TSH (-1.0 ± 30.0% vs. 1.5 ± 26.5%) levels between non-C allele carriers and C allele carriers of the MC4Rrs17782313 (Ps>0.3). Finally, there were no significant difference on changes in body mass and composition, REE, leptin or TSH levels among non-risk allele carriers, carriers of the C allele risk of the MC4Rrs17782313, carriers of the A allele of the FTOrs9939609 and carriers of both risk alleles after the 12-week energy-restricted diet intervention (Ps>0.1). Carrying the A risk allele of the FTOrs9939609 and/or the C risk allele of the MC4Rrs17782313 did not influence body mass and FM loss, or REE decrease in obese women after a 12-week energy-restricted diet intervention. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  3. Direct mass measurements of neutron-deficient xenon isotopes with the ISOLTRAP mass spectrometer

    International Nuclear Information System (INIS)

    Dilling, J.; Audi, G.; Beck, D.; Bollen, G.; Henry, S.; Herfurth, F.; Kellerbauer, A.; Kluge, H.-J.; Lunney, D.; Moore, R.B.; Scheidenberger, C.; Schwarz, S.; Sikler, G.; Szerypo, J.

    2002-01-01

    The masses of Xe isotopes with 124≥A≥114 have been measured using the ISOLTRAP spectrometer at the on-line mass separator ISOLDE/CERN. A mass resolving power of 500 000 was chosen resulting in an accuracy of δm∼12 keV for all isotopes investigated. Conflicts with existing mass data of several standard deviations were found

  4. A strategy based on gas chromatography-mass spectrometry and virtual molecular docking for analysis and prediction of bioactive composition in natural product essential oil.

    Science.gov (United States)

    Wang, Haiyang; Gu, Dongyu; Wang, Miao; Guo, Hong; Wu, Huijuan; Tian, Guangliang; Li, Qian; Yang, Yi; Tian, Jing

    2017-06-09

    The discovery of leads from medicinal plants is crucial to drug development. The present study presents a strategy based on GC-MS coupled with molecular docking for analysis, identification and prediction of protein tyrosine phosphatase 1B inhibitors in the essential oil from Himalayan Cedar (HC). The essential oil with IC 50 value of 120.71±0.26μg/mL exhibited potential activity against protein tyrosine phosphatase 1B (PTP1B) in vitro. After GC-MS analysis, 35 compounds were identified from this oil. The identified compounds were individually docked with PTP1B. Caryophyllene oxide with the lowest binding energy of -6.28kcal/mol was completely wrapped by the active site of PTP1B. The docking results indicated that caryophyllene oxide has potential PTP1B inhibitory activity and may be responsible for the PTP1B inhibitory activity of the essential oil. Caryophyllene oxide in the essential oil of Himalayan Cedar was isolated by HSCCC and the PTP1B inhibitory activity of this compound was then evaluated; the IC 50 value was 31.32±0.38μM. The result revealed that the present strategy can effectively discover the active composition from the complex mixture of medicinal plants. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Diagnostic accuracy in virtual dermatopathology

    DEFF Research Database (Denmark)

    Mooney, E.; Kempf, W.; Jemec, G.B.E.

    2012-01-01

    Background Virtual microscopy is used for teaching medical students and residents and for in-training and certification examinations in the United States. However, no existing studies compare diagnostic accuracy using virtual slides and photomicrographs. The objective of this study was to compare...... diagnostic accuracy of dermatopathologists and pathologists using photomicrographs vs. digitized images, through a self-assessment examination, and to elucidate assessment of virtual dermatopathology. Methods Forty-five dermatopathologists and pathologists received a randomized combination of 15 virtual...... slides and photomicrographs with corresponding clinical photographs and information in a self-assessment examination format. Descriptive data analysis and comparison of groups were performed using a chi-square test. Results Diagnostic accuracy in dermatopathology using virtual dermatopathology...

  6. Interannual variability of dust-mass loading and composition of dust deposited on snow cover in the San Juan Mountains, CO, USA: Insights into effects on snow melt

    Science.gov (United States)

    Goldstein, H. L.; Reynolds, R. L.; Derry, J.; Kokaly, R. F.; Moskowitz, B. M.

    2017-12-01

    Dust deposited on snow cover (DOS) in the American West can enhance snow-melt rates and advance the timing of melting, which together can result in earlier-than-normal runoff and overall smaller late-season water supplies. Understanding DOS properties and how they affect the absorption of solar radiation can lead to improved snow-melt models by accounting for important dust components. Here, we report on the interannual variability of DOS-mass loading, particle size, organic matter, and iron mineralogy, and their correspondences to laboratory-measured reflectance of samples from the Swamp Angel Study Plot in the San Juan Mountains, Colorado, USA. Samples were collected near the end of spring in water year 2009 (WY09) and from WY11-WY16, when dust layers deposited throughout the year had merged into one layer at the snow surface. Dust-mass loading on snow ranged 2-64 g/m2, mostly as particles with median sizes of 13-33 micrometers. Average reflectance values of DOS varied little across total (0.4 to 2.50 µm) and visible (0.4 to 0.7 µm) wavelengths at 0.30-0.45 and 0.19-0.27, respectively. Reflectance values lacked correspondence to particle-size. Total reflectance values inversely corresponded to concentrations of (1) organic matter content (4-20 weight %; r2 = 0.71) that included forms of black carbon and locally derived material such as pollen, and (2) magnetite (0.05 to 0.13 weight %; r2 = 0.44). Magnetite may be a surrogate for related dark, light-absorbing minerals. Concentrations of crystalline ferric oxide minerals (hematite+goethite) based on magnetic properties at room-temperature did not show inverse association to visible reflectance values. These ferric oxide measures, however, did not account for the amounts of nano-sized ferric oxides known to exist in these samples. Quantification of such nano-sized particles is required to evaluate their possible effects on visible reflectance. Nonetheless, our results emphasize that reflectance values of year

  7. Applicability of a two-step laser desorption-ionization aerosol time-of-flight mass spectrometer for determination of chemical composition of ultrafine aerosol particles

    Energy Technology Data Exchange (ETDEWEB)

    Laitinen, T.

    2013-11-01

    This thesis is based on the construction of a two-step laser desorption-ionization aerosol time-of-flight mass spectrometer (laser AMS), which is capable of measuring 10 to 50 nm aerosol particles collected from urban and rural air at-site and in near real time. The operation and applicability of the instrument was tested with various laboratory measurements, including parallel measurements with filter collection/chromatographic analysis, and then in field experiments in urban environment and boreal forest. Ambient ultrafine aerosol particles are collected on a metal surface by electrostatic precipitation and introduced to the time-of-flight mass spectrometer (TOF-MS) with a sampling valve. Before MS analysis particles are desorbed from the sampling surface with an infrared laser and ionized with a UV laser. The formed ions are guided to the TOF-MS by ion transfer optics, separated according to their m/z ratios, and detected with a micro channel plate detector. The laser AMS was used in urban air studies to quantify the carbon cluster content in 50 nm aerosol particles. Standards for the study were produced from 50 nm graphite particles, suspended in toluene, with 72 hours of high power sonication. The results showed the average amount of carbon clusters (winter 2012, Helsinki, Finland) in 50 nm particles to be 7.2% per sample. Several fullerenes/fullerene fragments were detected during the measurements. In boreal forest measurements, the laser AMS was capable of detecting several different organic species in 10 to 50 nm particles. These included nitrogen-containing compounds, carbon clusters, aromatics, aliphatic hydrocarbons, and oxygenated hydrocarbons. A most interesting event occurred during the boreal forest measurements in spring 2011 when the chemistry of the atmosphere clearly changed during snow melt. On that time concentrations of laser AMS ions m/z 143 and 185 (10 nm particles) increased dramatically. Exactly at the same time, quinoline concentrations

  8. Indicator for success of obesity reduction programs in adolescents: Body composition or body mass index? evaluating a school-based health promotion project after 12 weeks of intervention

    Directory of Open Access Journals (Sweden)

    Naser Kalantari

    2017-01-01

    Full Text Available Background: Obesity in adolescence is the strongest risk factor for obesity in adulthood. This study aimed to evaluate the effects of a comprehensive lifestyle intervention on different anthropometric indices in 12–16-year-old boy adolescents after 12 Weeks of Intervention. Methods: A total of 96 male adolescents from two schools participated in this study. The schools were randomly assigned to intervention (53 students and control school (43 students. Height and weight of students were measured and their body mass index (BMI was calculated. Body fat percent (BF and body muscle percent (BM was assessed using a bioimpedance analyzer considering the age, gender, and height of students at baseline and after intervention. The obesity reduction intervention was implemented in the intervention school based on the Ottawa charter for health promotion. Results: Twelve weeks of intervention decreased BF percent in the intervention group in comparison with the control group (decreased by 1.81% in the intervention group and increased by 0.39% in the control group, P < 0.01. However, weight, BMI, and BM did not change significantly. Conclusions: The result of this study showed that a comprehensive lifestyle intervention decreased the body fat percent in obese adolescents, although these changes was not reflected in the BMI. It is possible that BMI is not a good indicator in assessment of the success of obesity management intervention.

  9. Composition profiles of several contaminated and cleaned surfaces of gold thick films on copper plates by Auger electron and secondary ion mass spectroscopies

    International Nuclear Information System (INIS)

    Komiya, S.; Mizuno, M.; Narusawa, T.; Maeda, H.; Yoshikawa, M.

    1974-01-01

    Preparation and evaluation of a clean Au film are investigated. Development of a preparation method for obtaining clean surface on a copper shell in the JFT-2a (DIVA) TOKAMAK toroidal vacuum chamber is the aim of the present work. Au films prepared by ion plating and vacuum evaporation have been analysed by a cylindrical mirror Auger electron analyser in combination with a quadrupole mass spectrometer during 2 keV Xe ion bombardment from a sputter ion gun over the whole range of thickness of several microns. Contaminants are found to segregate on the top surface and at the interface. To expose a clean Au surface by the ion bombardment, surface layers within 1000 A had to be removed from the surfaces contaminated by touching with either a naked hand or a nylon glove or covered by a small amount of Ti. Mutual diffusions across the interfaces are also analyzed as a function of the substrate temperature. A Nb sandwich layer inhibites effectively the mutual diffusion. (auth.)

  10. Analysis of the chemical composition of the essential oils extracted from Lippia lacunosa Mart. and Schauer and Lippia rotundifolia Cham. (Verbenaceae) by gas chromatography and gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Leitao, Suzana G.; Barbosa, Ymira Galico; Viccini, Lyderson F.; Salimena, Fatima R.G.; Peixoto, Paulo H.P.

    2008-01-01

    Lippia lacunosa and L. rotundifolia (Verbenaceae) are two Brazilian species of complex taxonomic delimitation. The composition of the essential oils from leaves and flowers of these plants was investigated by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS) analysis. The major components of the essential oils of flowers and leaves of L. lacunosa were: myrcene (14.7% and 11.9%), myrcenone (45.2% and 64.2%), Z-ocimenone (5.7% and 5.2%), and E-ocimenone (14.7% and 4.1%), respectively; whereas in L. rotundifolia (flowers and leaves) were ..-pinene (8.7% and 1.8%), myrcene (5.1% and 3.6%), limonene (26.0% and 7.9 %), cis-pinocamphone (4.5% and 3.1%) and myrtenal (22.3% and 16.7%), respectively. The essential oils from L. lacunosa exhibited a strong and pleasant mango aroma, which was related to the presence of myrcene and myrcenone. The marked differences in the chemical composition of their essential oils may represent a powerful tool for the botanical classification. (author)

  11. Analysis of the chemical composition of the essential oils extracted from Lippia lacunosa Mart. and Schauer and Lippia rotundifolia Cham. (Verbenaceae) by gas chromatography and gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, Suzana G.; Barbosa, Ymira Galico [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Fac. de Farmacia; Oliveira, Danilo R. de; Leitao, Gilda G. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Nucleo de Pesquisas de Produtos Naturais]. E-mail: sgleitao@pharma.ufrj.br; Suelsen, Valeria; Martino, Virginia [Universidad de Buenos Aires (Argentina). Facultad de Farmacia y Bioquimica; Bizzo, Humberto R.; Lopes, Daise [EMBRAPA Agroindustria de Alimentos, Rio de Janeiro, RJ (Brazil); Viccini, Lyderson F.; Salimena, Fatima R.G.; Peixoto, Paulo H.P. [Universidade Federal de Juiz de Fora (UFJF), Juiz de Fora, MG (Brazil). Inst. de Ciencias Biolgicas

    2008-07-01

    Lippia lacunosa and L. rotundifolia (Verbenaceae) are two Brazilian species of complex taxonomic delimitation. The composition of the essential oils from leaves and flowers of these plants was investigated by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS) analysis. The major components of the essential oils of flowers and leaves of L. lacunosa were: myrcene (14.7% and 11.9%), myrcenone (45.2% and 64.2%), Z-ocimenone (5.7% and 5.2%), and E-ocimenone (14.7% and 4.1%), respectively; whereas in L. rotundifolia (flowers and leaves) were ..-pinene (8.7% and 1.8%), myrcene (5.1% and 3.6%), limonene (26.0% and 7.9 %), cis-pinocamphone (4.5% and 3.1%) and myrtenal (22.3% and 16.7%), respectively. The essential oils from L. lacunosa exhibited a strong and pleasant mango aroma, which was related to the presence of myrcene and myrcenone. The marked differences in the chemical composition of their essential oils may represent a powerful tool for the botanical classification. (author)

  12. Determination of The Anti-Fungal Effort of Morganella Morganii and Determination of Its Chemical Composition by Means of Gas Chromatography Method - Mass Spectrometry Gas Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Sabreen Abdul Amir Kamal Al – Khafaji

    2018-03-01

    Full Text Available The analysis of bioactive was done by used gas chromatography-mass spectroscopy(GC-MS method then antifungal and antimicrobial activity for methanolic extract was measured in the lab. The analysis of  Morganella morganii  by GC-MS revealed the existence of the Tricyclo, 3-Methoxybenzaldehyde semicarbazone , undecan-1-amine, carboxaldehyde , 1-methyl-,oxime ,(Z-(+, 4-(2,5-Dihydro-3-methoxyphenyl butylamine , Paromomycin , 1,5,5-Trimethyl-6-methylene-cyclohexene, 9-Borabicyclo[3.31], Benzenemethanol , nonane , 9-mercapto-2-(2-aminopropoxy-3-methyl, Acetamide , N-(6-acetylaminobenzothiazol-2-yl-2-(adamantan, rin-6-carboxylic acid , N-(2,5-Dicyano-3,4-dihydro-2H-pyrrol-2-yl- acetamide, 3,10-Dioxatricyclo4-(2,5-Dihydro-3-methoxyphenylbutylamine, [4.3.1.0(2,4] phenylmethyl ester, 3,7-Diazabicyclo dec-7-ene, 3-Cyclohex-3-enyl-propionic acid, Eicosanoic acid  [3.3.1] 9,9-dimethyl-, nonane ,Dithiocarbamate , dl-Homocysteine, 2-(2-Furylpyridine, S-methyl-,N-(2-methyl-3-oxobutyl-, 1,7-Dioxa-10-thia-4,13-diazacyclopentadeca-5,9,12-trione, 5,7-Dodecadiyn-1,12-diol, 1-(β-d-Arabinofuranosyl-4-O-difluoromethyluracil, Uric acid, Pyrrolo[1.2-a]pyrazine-1,4-dione , hexahydro-,12-Methyl-oxa-cyclododecan-2-one, Phthalic acid , butyl undecyl ester, 9,12,15-Octadecatrienoic acid , 2,3-bis(acetyloxypropyl ester, , methyl ester, 12-Dimethylamino-10-oxododecanoic acid , 1,2,4-Trioxolane-2-octanoic acid 5-octyl-, Octahydrochromen-2-one, L-Aspartic acid, N-glycyl-,2H-Oxecin-2-one , 3,4,7,8,91,10-hexahydro-4-hydroxy-10-meth, Thiazolo[4,5-d]pyrimidine-5,7(4H,6H-dione , 3,6,12-Trimethyl-1,4,7,10,13,16-hexaaza-cyclooctadecane, 2-lodohiistidine, 2-amino-4-(2-ph,Dec-9-en-6-oxo-1-ylamide,2,5-Piperazinedione,3,6-bis(2-ethylpropyl-, 9-Octadecenamide , (Z-, 3',8,8'-Trimethoxy-3-piperidyl-2,2'-binaphthalene-1,1',4,4'-tetra . Citrullus colocynthis (Crude was very highly active (6.39±0.27 mm anti-fungal activity of Morganella morganii showed that unstable compounds ( volatile were

  13. Contrast in air pollution components between major streets and background locations: Particulate matter mass, black carbon, elemental composition, nitrogen oxide and ultrafine particle number

    Science.gov (United States)

    Boogaard, Hanna; Kos, Gerard P. A.; Weijers, Ernie P.; Janssen, Nicole A. H.; Fischer, Paul H.; van der Zee, Saskia C.; de Hartog, Jeroen J.; Hoek, Gerard

    2011-01-01

    Policies to reduce outdoor air pollution concentrations are often assessed on the basis of the regulated pollutants. Whether these are the most appropriate components to assess the potential health benefits is questionable, as other health-relevant pollutants may be more strongly related to traffic. The aim of this study is to compare the contrast in concentration between major roads and (sub)urban background for a large range of pollutants and to analyze the magnitude of the measured difference in the street - background for major streets with different street configurations. Measurements of PM 10, PM 2.5, particle number concentrations (PNC), black carbon (BC), elemental composition of PM 10 and PM 2.5 and NO x were conducted simultaneously in eight major streets and nine (sub)urban background locations in the Netherlands. Measurements were done six times for a week during a six month period in 2008. High contrasts between busy streets and background locations in the same city were found for chromium, copper and iron (factor 2-3). These elements were especially present in the coarse fraction of PM. In addition, high contrasts were found for BC and NO x (factor 1.8), typically indicators of direct combustion emissions. The contrast for PNC was similar to BC. NO 2 contrast was lower (factor 1.5). The largest contrast was found for two street canyons and two streets with buildings at one side of the street only. The contrast between busy streets and urban background in NO 2 was less than the contrast found for BC, PNC and elements indicative of non-exhaust emissions, adding evidence that NO 2 is not representing (current) traffic well. The study supports a substantial role for non-exhaust emissions including brake- and tyre wear and road dust in addition to direct combustion emissions. Significant underestimation of disease burden may occur when relying too much on the regulated components.

  14. A Metabolomic Approach Applied to a Liquid Chromatography Coupled to High-Resolution Tandem Mass Spectrometry Method (HPLC-ESI-HRMS/MS): Towards the Comprehensive Evaluation of the Chemical Composition of Cannabis Medicinal Extracts.

    Science.gov (United States)

    Citti, Cinzia; Battisti, Umberto Maria; Braghiroli, Daniela; Ciccarella, Giuseppe; Schmid, Martin; Vandelli, Maria Angela; Cannazza, Giuseppe

    2018-03-01

    Cannabis sativa L. is a powerful medicinal plant and its use has recently increased for the treatment of several pathologies. Nonetheless, side effects, like dizziness and hallucinations, and long-term effects concerning memory and cognition, can occur. Most alarming is the lack of a standardised procedure to extract medicinal cannabis. Indeed, each galenical preparation has an unknown chemical composition in terms of cannabinoids and other active principles that depends on the extraction procedure. This study aims to highlight the main differences in the chemical composition of Bediol® extracts when the extraction is carried out with either ethyl alcohol or olive oil for various times (0, 60, 120 and 180 min for ethyl alcohol, and 0, 60, 90 and 120 min for olive oil). Cannabis medicinal extracts (CMEs) were analysed by liquid chromatography coupled to high-resolution tandem mass spectrometry (LC-MS/MS) using an untargeted metabolomics approach. The data sets were processed by unsupervised multivariate analysis. Our results suggested that the main difference lies in the ratio of acid to decarboxylated cannabinoids, which dramatically influences the pharmacological activity of CMEs. Minor cannabinoids, alkaloids, and amino acids contributing to this difference are also discussed. The main cannabinoids were quantified in each extract applying a recently validated LC-MS and LC-UV method. Notwithstanding the use of a standardised starting plant material, great changes are caused by different extraction procedures. The metabolomics approach is a useful tool for the evaluation of the chemical composition of cannabis extracts. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  15. Calcium Isotope Analysis by Mass Spectrometry

    Science.gov (United States)

    Boulyga, S.; Richter, S.

    2010-12-01

    The variations in the isotopic composition of calcium caused by fractionation in heterogeneous systems and by nuclear reactions can provide insight into numerous biological, geological, and cosmic processes, and therefore isotopic analysis finds a wide spectrum of applications in cosmo- and geochemistry, paleoclimatic, nutritional, and biomedical studies. The measurement of calcium isotopic abundances in natural samples has challenged the analysts for more than three decades. Practically all Ca isotopes suffer from significant isobaric interferences, whereas low-abundant isotopes can be particularly affected by neighboring major isotopes. The extent of natural variations of stable isotopes appears to be relatively limited, and highly precise techniques are required to resolve isotopic effects. Isotope fractionation during sample preparation and measurements and instrumental mass bias can significantly exceed small isotope abundance variations in samples, which have to be investigated. Not surprisingly, a TIMS procedure developed by Russell et al. (Russell et al., 1978. Geochim Cosmochim Acta 42: 1075-1090) for Ca isotope measurements was considered as revolutionary for isotopic measurements in general, and that approach is used nowadays (with small modifications) for practically all isotopic systems and with different mass spectrometric techniques. Nevertheless, despite several decades of calcium research and corresponding development of mass spectrometers, the available precision and accuracy is still not always sufficient to achieve the challenging goals. This presentation discusses figures of merits of presently used analytical methods and instrumentation, and attempts to critically assess their limitations. Additionally, the availability of Ca isotope reference materials will be discussed.

  16. Effects of 28 days of resistance exercise and consuming a commercially available pre-workout supplement, NO-Shotgun®, on body composition, muscle strength and mass, markers of satellite cell activation, and clinical safety markers in males

    Directory of Open Access Journals (Sweden)

    Leutholtz Brian

    2009-08-01

    Full Text Available Abstract Purpose This study determined the effects of 28 days of heavy resistance exercise combined with the nutritional supplement, NO-Shotgun®, on body composition, muscle strength and mass, markers of satellite cell activation, and clinical safety markers. Methods Eighteen non-resistance-trained males participated in a resistance training program (3 × 10-RM 4 times/wk for 28 days while also ingesting 27 g/day of placebo (PL or NO-Shotgun® (NO 30 min prior to exercise. Data were analyzed with separate 2 × 2 ANOVA and t-tests (p Results Total body mass was increased in both groups (p = 0.001, but without any significant increases in total body water (p = 0.77. No significant changes occurred with fat mass (p = 0.62; however fat-free mass did increase with training (p = 0.001, and NO was significantly greater than PL (p = 0.001. Bench press strength for NO was significantly greater than PL (p = 0.003. Myofibrillar protein increased with training (p = 0.001, with NO being significantly greater than PL (p = 0.019. Serum IGF-1 (p = 0.046 and HGF (p = 0.06 were significantly increased with training and for NO HGF was greater than PL (p = 0.002. Muscle phosphorylated c-met was increased with training for both groups (p = 0.019. Total DNA was increased in both groups (p = 0.006, while NO was significantly greater than PL (p = 0.038. For DNA/protein, PL was decreased and NO was not changed (p = 0.014. All of the myogenic regulatory factors were increased with training; however, NO was shown to be significantly greater than PL for Myo-D (p = 0.008 and MRF-4 (p = 0.022. No significant differences were located for any of the whole blood and serum clinical chemistry markers (p > 0.05. Conclusion When combined with heavy resistance training for 28 days, NO-Shotgun® is not associated with any negative side effects, nor does it abnormally impact any of the clinical chemistry markers. Rather, NO-Shotgun® effectively increases muscle strength and mass

  17. Hyphenation of a carbon analyzer to photo-ionization mass spectrometry to unravel the organic composition of particulate matter on a molecular level.

    Science.gov (United States)

    Grabowsky, Jana; Streibel, Thorsten; Sklorz, Martin; Chow, Judith C; Watson, John G; Mamakos, Athanasios; Zimmermann, Ralf

    2011-12-01

    The carbonaceous fraction of airborne particulate matter (PM) is of increasing interest due to the adverse health effects they are linked to. Its analytical ascertainment on a molecular level is still challenging. Hence, analysis of carbonaceous fractions is often carried out by determining bulk parameters such as the overall content of organic compounds (OC) and elemental carbon (EC) as well as the total carbon content, TC (sum of OC and EC), however, no information about the individual substances or substance classes, of which the single fractions consist can be obtained. In this work, a carbon analyzer and a photo-ionization time-of-flight mass spectrometer (PI-TOF-MS) were hyphenated to investigate individual compounds especially from the OC fractions. The carbon analyzer enables the stepwise heating of particle samples and provides the bulk parameters. With the PI-TOF-MS, it is possible to detect the organic compounds released during the single-temperature steps due to soft ionization and fast detection of the molecular ions. The hyphenation was designed, built up, characterized by standard substances, and applied to several kinds of samples, such as ambient aerosol, gasoline, and diesel emission as well as wood combustion emission samples. The ambient filter sample showed a strong impact of wood combustion markers. This was revealed by comparison to the product pattern of the similar analysis of pure cellulose and lignin and the wood combustion PM. At higher temperatures (450 °C), a shift to smaller molecules occurred due to the thermal decomposition of larger structures of oligomeric or polymeric nature comparable to lignocelluloses and similar oxygenated humic-like substances. Finally, particulate matter from gasoline and diesel containing 10% biodiesel vehicle exhaust has been analyzed. Gasoline-derived PM exhibited large polycyclic aromatic hydrocarbons, whereas diesel PM showed a much higher total organic content. The detected pattern revealed a strong

  18. Fully automatic and precise data analysis developed for time-of-flight mass spectrometry.

    Science.gov (United States)

    Meyer, Stefan; Riedo, Andreas; Neuland, Maike B; Tulej, Marek; Wurz, Peter

    2017-09-01

    Scientific objectives of current and future space missions are focused on the investigation of the origin and evolution of the solar system with the particular emphasis on habitability and signatures of past and present life. For in situ measurements of the chemical composition of solid samples on planetary surfaces, the neutral atmospheric gas and the thermal plasma of planetary atmospheres, the application of mass spectrometers making use of time-of-flight mass analysers is a technique widely used. However, such investigations imply measurements with good statistics and, thus, a large amount of data to be analysed. Therefore, faster and especially robust automated data analysis with enhanced accuracy is required. In this contribution, an automatic data analysis software, which allows fast and precise quantitative data analysis of time-of-flight mass spectrometric data, is presented and discussed in detail. A crucial part of this software is a robust and fast peak finding algorithm with a consecutive numerical integration method allowing precise data analysis. We tested our analysis software with data from different time-of-flight mass spectrometers and different measurement campaigns thereof. The quantitative analysis of isotopes, using automatic data analysis, yields results with an accuracy of isotope ratios up to 100 ppm for a signal-to-noise ratio (SNR) of 10 4 . We show that the accuracy of isotope ratios is in fact proportional to SNR -1 . Furthermore, we observe that the accuracy of isotope ratios is inversely proportional to the mass resolution. Additionally, we show that the accuracy of isotope ratios is depending on the sample width T s by T s 0.5 . Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  19. Cadastral Database Positional Accuracy Improvement

    Science.gov (United States)

    Hashim, N. M.; Omar, A. H.; Ramli, S. N. M.; Omar, K. M.; Din, N.

    2017-10-01

    Positional Accuracy Improvement (PAI) is the refining process of the geometry feature in a geospatial dataset to improve its actual position. This actual position relates to the absolute position in specific coordinate system and the relation to the neighborhood features. With the growth of spatial based technology especially Geographical Information System (GIS) and Global Navigation Satellite System (GNSS), the PAI campaign is inevitable especially to the legacy cadastral database. Integration of legacy dataset and higher accuracy dataset like GNSS observation is a potential solution for improving the legacy dataset. However, by merely integrating both datasets will lead to a distortion of the relative geometry. The improved dataset should be further treated to minimize inherent errors and fitting to the new accurate dataset. The main focus of this study is to describe a method of angular based Least Square Adjustment (LSA) for PAI process of legacy dataset. The existing high accuracy dataset known as National Digital Cadastral Database (NDCDB) is then used as bench mark to validate the results. It was found that the propose technique is highly possible for positional accuracy improvement of legacy spatial datasets.

  20. Classification Accuracy Is Not Enough

    DEFF Research Database (Denmark)

    Sturm, Bob L.

    2013-01-01

    A recent review of the research literature evaluating music genre recognition (MGR) systems over the past two decades shows that most works (81\\%) measure the capacity of a system to recognize genre by its classification accuracy. We show here, by implementing and testing three categorically...

  1. The hidden KPI registration accuracy.

    Science.gov (United States)

    Shorrosh, Paul

    2011-09-01

    Determining the registration accuracy rate is fundamental to improving revenue cycle key performance indicators. A registration quality assurance (QA) process allows errors to be corrected before bills are sent and helps registrars learn from their mistakes. Tools are available to help patient access staff who perform registration QA manually.

  2. Performance results of a mobile high-resolution MR-TOF mass spectrometer for in-situ analytical mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lippert, Wayne; Lang, Johannes [Justus-Liebig-Universitaet Giessen (Germany); Ayet San Andres, Samuel [GSI, Darmstadt (Germany); Dickel, Timo; Geissel, Hans; Plass, Wolfgang; Scheidenberger, Christoph [Justus-Liebig-Universitaet Giessen (Germany); GSI, Darmstadt (Germany); Yavor, Mikhail [RAS St. Petersburg (Russian Federation)

    2014-07-01

    A mobile multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) has been developed which provides a mass resolving power exceeding 250,000 and sub-ppm mass accuracy in a transportable format. Thus it allows resolving isobars and enables accurate determination of the composition and structure of biomolecules. Furthermore the device offers high mass resolving MS/MS capability via selective ion re-trapping and collisional-induced dissociation (CID). An atmospheric pressure interface (API) provides for routine measurements with various atmospheric ion sources. All supply electronics, DAQ and control system are mounted with the spectrometer into a single frame with a total volume of only 0.8 m{sup 3}. With the current system many applications like waste water monitoring at hot spots, mass-based classification of biomolecules and breath analysis are possible. In addition the mass spectrometer is readily scalable and can be adopted and simplified for even more specific use like in space science for instance. A characterization and first performance results are shown, and the implementation of MS/MS in combination with CID is discussed.

  3. Accuracy in Optical Information Processing

    Science.gov (United States)

    Timucin, Dogan Aslan

    Low computational accuracy is an important obstacle for optical processors which blocks their way to becoming a practical reality and a serious challenger for classical computing paradigms. This research presents a comprehensive solution approach to the problem of accuracy enhancement in discrete analog optical information processing systems. Statistical analysis of a generic three-plane optical processor is carried out first, taking into account the effects of diffraction, interchannel crosstalk, and background radiation. Noise sources included in the analysis are photon, excitation, and emission fluctuations in the source array, transmission and polarization fluctuations in the modulator, and photoelectron, gain, dark, shot, and thermal noise in the detector array. Means and mutual coherence and probability density functions are derived for both optical and electrical output signals. Next, statistical models for a number of popular optoelectronic devices are studied. Specific devices considered here are light-emitting and laser diode sources, an ideal noiseless modulator and a Gaussian random-amplitude-transmittance modulator, p-i-n and avalanche photodiode detectors followed by electronic postprocessing, and ideal free-space geometrical -optics propagation and single-lens imaging systems. Output signal statistics are determined for various interesting device combinations by inserting these models into the general formalism. Finally, based on these special-case output statistics, results on accuracy limitations and enhancement in optical processors are presented. Here, starting with the formulation of the accuracy enhancement problem as (1) an optimal detection problem and (2) as a parameter estimation problem, the potential accuracy improvements achievable via the classical multiple-hypothesis -testing and maximum likelihood and Bayesian parameter estimation methods are demonstrated. Merits of using proper normalizing transforms which can potentially stabilize

  4. Estimation of transport parameters of phenolic compounds and inorganic contaminants through composite landfill liners using one-dimensional mass transport model

    International Nuclear Information System (INIS)

    Varank, Gamze; Demir, Ahmet; Yetilmezsoy, Kaan; Bilgili, M. Sinan; Top, Selin; Sekman, Elif

    2011-01-01

    Highlights: → We conduct 1D advection-dispersion modeling to estimate transport parameters. → We examine fourteen phenolic compounds and three inorganic contaminants. → 2-MP, 2,4-DCP, 2,6-DCP, 2,4,5-TCP, 2,3,4,6-TeCP have the highest coefficients. → Dispersion coefficients of Cu are determined to be higher than Zn and Fe. → Transport of phenolics can be prevented by zeolite and bentonite in landfill liners. - Abstract: One-dimensional (1D) advection-dispersion transport modeling was conducted as a conceptual approach for the estimation of the transport parameters of fourteen different phenolic compounds (phenol, 2-CP, 2-MP, 3-MP, 4-MP, 2-NP, 4-NP, 2,4-DNP, 2,4-DCP, 2,6-DCP, 2,4,5-TCP, 2,4,6-TCP, 2,3,4,6-TeCP, PCP) and three different inorganic contaminants (Cu, Zn, Fe) migrating downward through the several liner systems. Four identical pilot-scale landfill reactors (0.25 m 3 ) with different composite liners (R1: 0.10 + 0.10 m of compacted clay liner (CCL), L e = 0.20 m, k e = 1 x 10 -8 m/s, R2: 0.002-m-thick damaged high-density polyethylene (HDPE) geomembrane overlying 0.10 + 0.10 m of CCL, L e = 0.20 m, k e = 1 x 10 -8 m/s, R3: 0.002-m-thick damaged HDPE geomembrane overlying a 0.02-m-thick bentonite layer encapsulated between 0.10 + 0.10 m CCL, L e = 0.22 m, k e = 1 x 10 -8 m/s, R4: 0.002-m-thick damaged HDPE geomembrane overlying a 0.02-m-thick zeolite layer encapsulated between 0.10 + 0.10 m CCL, L e = 0.22 m, k e = 4.24 x 10 -7 m/s) were simultaneously run for a period of about 540 days to investigate the nature of diffusive and advective transport of the selected organic and inorganic contaminants. The results of 1D transport model showed that the highest molecular diffusion coefficients, ranging from 4.77 x 10 -10 to 10.67 x 10 -10 m 2 /s, were estimated for phenol (R4), 2-MP (R1), 2,4-DNP (R2), 2,4-DCP (R1), 2,6-DCP (R2), 2,4,5-TCP (R2) and 2,3,4,6-TeCP (R1). For all reactors, dispersion coefficients of Cu, ranging from 3.47 x 10 -6 m 2 /s to 5

  5. Improve accuracy and sensibility in glycan structure prediction by matching glycan isotope abundance

    International Nuclear Information System (INIS)

    Xu Guang; Liu Xin; Liu Qingyan; Zhou Yanhong; Li Jianjun

    2012-01-01

    Highlights: ► A glycan isotope pattern recognition strategy for glycomics. ► A new data preprocessing procedure to detect ion peaks in a giving MS spectrum. ► A linear soft margin SVM classification for isotope pattern recognition. - Abstract: Mass Spectrometry (MS) is a powerful technique for the determination of glycan structures and is capable of providing qualitative and quantitative information. Recent development in computational method offers an opportunity to use glycan structure databases and de novo algorithms for extracting valuable information from MS or MS/MS data. However, detecting low-intensity peaks that are buried in noisy data sets is still a challenge and an algorithm for accurate prediction and annotation of glycan structures from MS data is highly desirable. The present study describes a novel algorithm for glycan structure prediction by matching glycan isotope abundance (mGIA), which takes isotope masses, abundances, and spacing into account. We constructed a comprehensive database containing 808 glycan compositions and their corresponding isotope abundance. Unlike most previously reported methods, not only did we take into count the m/z values of the peaks but also their corresponding logarithmic Euclidean distance of the calculated and detected isotope vectors. Evaluation against a linear classifier, obtained by training mGIA algorithm with datasets of three different human tissue samples from Consortium for Functional Glycomics (CFG) in association with Support Vector Machine (SVM), was proposed to improve the accuracy of automatic glycan structure annotation. In addition, an effective data preprocessing procedure, including baseline subtraction, smoothing, peak centroiding and composition matching for extracting correct isotope profiles from MS data was incorporated. The algorithm was validated by analyzing the mouse kidney MS data from CFG, resulting in the identification of 6 more glycan compositions than the previous annotation

  6. Desempenho de pontos de corte do índice de massa corporal de diferentes referências na predição de gordura corporal em adolescentes Accuracy of different body mass index reference values to predict body fat in adolescents

    Directory of Open Access Journals (Sweden)

    Ana Carolina Reiff e Vieira

    2006-08-01

    Full Text Available Avaliamos a acurácia de pontos de corte do Índice de Massa Corporal (IMC para identificar adolescentes com sobrepeso, comparando com percentual de gordura corporal, estimado pela bioimpedância elétrica, em uma amostra probabilística de 610 adolescentes de 12 a 19 anos (222 meninos e 388 meninas, estudantes de escolas públicas de Niterói, Rio de Janeiro, Brasil. A curva ROC foi utilizada para avaliar a sensibilidade e especificidade de pontos de corte de IMC de uma referência nacional, duas norte-americanas e uma internacional. Os pontos de corte da amostra estudada foram inferiores aos das demais referências, com sensibilidade de 76% a 95% e especificidade de 75% a 95%. Os pontos de corte nacionais foram também mais sensíveis (53% a 100%, se comparados às outras referências (40% a 86%. O critério internacional apresentou melhor sensibilidade para adolescentes mais velhos e as referências americanas, para os mais jovens. O IMC foi um bom proxy de adiposidade, mas o uso de pontos de corte de referências de outras populações merece cautela, pois pode gerar erro na classificação de adolescente com sobrepeso em até 60%.This study evaluates the accuracy of cutoff points in the body mass index (BMI for identifying adolescents with overweight, compared to the percentage of body fat, estimated by electric bioimpediance, in a probabilistic sample of 610 adolescents from 12 to 19 years of age (222 boys and 388 girls enrolled in public schools in Niterói, Rio de Janeiro, Brazil. ROC was used to evaluate the sensitivity and specificity of BMI cutoffs from one Brazilian, two North American, and one international reference. The cutoff points in the study sample were lower than the other references, with 76% to 95% sensitivity and 75% to 95% specificity. The Brazilian cutoff points were also more sensitive (53% to 100% as compared to the other references (40% to 86%. The international parameter showed better sensitivity for older

  7. Prediction of fat-free body mass from bioelectrical impedance among 9- to 11-year-old Swedish children

    DEFF Research Database (Denmark)

    Nielsen, Birgit Marie; Dencker, M; Ward, L

    2007-01-01

    AIM: Predictive equations for estimating body composition from bioelectrical impedance analysis (BIA) among Scandinavian children are lacking. In the present study, equations for estimation of fat-free body mass (FFM) and lean tissue mass (LTM) were developed and cross-validated from BIA using dual...... linear regression and cross-validated against DXA measurements of body composition. RESULTS: FFM was predicted from BIA and anthropometric variables with an adjusted R(2)= 0.95 and root mean square error (RMSE) = 0.84 kg, and LTM was predicted with an adjusted R(2)= 0.95 and RMSE = 0.87 kg. Cross......-validation revealed a mean RMSE = 0.95 kg FFM and a mean RMSE = 0.96 kg LTM. Prediction of body composition from equations developed in previous literature was mixed when applied to the present cohort of children. CONCLUSIONS: FFM and LTM are predicted with sufficient accuracy at the population level. We recommend...

  8. Development and validation of an analytical method for the determination of lead isotopic composition using ICP-QMS

    OpenAIRE

    Rodríguez-Salazar, M. T.; Morton Bermea, O.; Hernández-Álvarez, E.; García-Arreola, M. E.; Ortuño-Arzate, M. T.

    2010-01-01

    This work reports a method for the precise and accurate determination of Pb isotope composition in soils and geological matrices by ICP-QMS. Three reference materials (AGV-2, SRM 2709 and JSO-1) were repeatedly measured, using ICP-QMS instruments in order to assess the quality of this analytical procedure. Mass discrimination was evaluated for Pb/Pb with Pb isotope reference material NIST SRM 981, and the correction applied to the above mentioned reference materials to achieve good accuracy o...

  9. Mass discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Broeckman, A. [Rijksuniversiteit Utrecht (Netherlands)

    1978-12-15

    In thermal ionization mass spectrometry the phenomenon of mass discrimination has led to the use of a correction factor for isotope ratio-measurements. The correction factor is defined as the measured ratio divided by the true or accepted value of this ratio. In fact this factor corrects for systematic errors of the whole procedure; however mass discrimination is often associated just with the mass spectrometer.

  10. Negative mass

    International Nuclear Information System (INIS)

    Hammond, Richard T

    2015-01-01

    Some physical aspects of negative mass are examined. Several unusual properties, such as the ability of negative mass to penetrate any armor, are analysed. Other surprising effects include the bizarre system of negative mass chasing positive mass, naked singularities and the violation of cosmic censorship, wormholes, and quantum mechanical results as well. In addition, a brief look into the implications for strings is given. (paper)

  11. Nominal Mass?

    Science.gov (United States)

    Attygalle, Athula B; Pavlov, Julius

    2017-08-01

    The current IUPAC-recommended definition of the term "nominal mass," based on the most abundant naturally occurring stable isotope of an element, is flawed. We propose that Nominal mass should be defined as the sum of integer masses of protons and neutrons in any chemical species. In this way, all isotopes and isotopologues can be assigned a definitive identifier. Graphical Abstract ᅟ.

  12. Sources, compositions, and optical properties of humic-like substances in Beijing during the 2014 APEC summit: Results from dual carbon isotope and Fourier-transform ion cyclotron resonance mass spectrometry analyses.

    Science.gov (United States)

    Mo, Yangzhi; Li, Jun; Jiang, Bin; Su, Tao; Geng, Xiaofei; Liu, Junwen; Jiang, Haoyu; Shen, Chengde; Ding, Ping; Zhong, Guangcai; Cheng, Zhineng; Liao, Yuhong; Tian, Chongguo; Chen, Yingjun; Zhang, Gan

    2018-08-01

    Humic-like substances (HULIS) are a class of high molecular weight, light-absorbing compounds that are highly related to brown carbon (BrC). In this study, the sources and compositions of HULIS isolated from fine particles collected in Beijing, China during the 2014 Asia-Pacific Economic Cooperation (APEC) summit were characterized based on carbon isotope ( 13 C and 14 C) and Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analyses, respectively. HULIS were the main light-absorbing components of water-soluble organic carbon (WSOC), accounting for 80.2 ± 6.1% of the WSOC absorption capacity at 365 nm. The carbon isotope data showed that HULIS had a lower non-fossil contribution (53 ± 4%) and were less enriched with 13 C (-24.2 ± 0.6‰) relative to non-HULIS (62 ± 8% and -20.8 ± 0.3‰, respectively). The higher relative intensity fraction of sulfur-containing compounds in HULIS before and after APEC was attributed to higher sulfur dioxide levels emitted from fossil fuel combustion, whereas the higher fraction of nitrogen-containing compounds during APEC may have been due to the relatively greater contribution of non-fossil compounds or the influence of nitrate radical chemistry. The results of investigating the relationships among the sources, elemental compositions, and optical properties of HULIS demonstrated that the light absorption of HULIS appeared to increase with increasing unsaturation degree, but decrease with increasing oxidation level. The unsaturation of HULIS was affected by both sources and aging level. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Current use of high-resolution mass spectrometry in drug screening relevant to clinical and forensic toxicology and doping control.

    Science.gov (United States)

    Ojanperä, Ilkka; Kolmonen, Marjo; Pelander, Anna

    2012-05-01

    Clinical and forensic toxicology and doping control deal with hundreds or thousands of drugs that may cause poisoning or are abused, are illicit, or are prohibited in sports. Rapid and reliable screening for all these compounds of different chemical and pharmaceutical nature, preferably in a single analytical method, is a substantial effort for analytical toxicologists. Combined chromatography-mass spectrometry techniques with standardised reference libraries have been most commonly used for the purpose. In the last ten years, the focus has shifted from gas chromatography-mass spectrometry to liquid chromatography-mass spectrometry, because of progress in instrument technology and partly because of the polarity and low volatility of many new relevant substances. High-resolution mass spectrometry (HRMS), which enables accurate mass measurement at high resolving power, has recently evolved to the stage that is rapidly causing a shift from unit-resolution, quadrupole-dominated instrumentation. The main HRMS techniques today are time-of-flight mass spectrometry and Orbitrap Fourier-transform mass spectrometry. Both techniques enable a range of different drug-screening strategies that essentially rely on measuring a compound's or a fragment's mass with sufficiently high accuracy that its elemental composition can be determined directly. Accurate mass and isotopic pattern acts as a filter for confirming the identity of a compound or even identification of an unknown. High mass resolution is essential for improving confidence in accurate mass results in the analysis of complex biological samples. This review discusses recent applications of HRMS in analytical toxicology.

  14. Validation of bioelectrical-impedance analysis as a measurement of change in body composition in obesity

    International Nuclear Information System (INIS)

    Kushner, R.F.; Kunigk, A.; Alspaugh, M.; Andronis, P.T.; Leitch, C.A.; Schoeller, D.A.

    1990-01-01

    The bioelectrical-impedance-analysis (BIA) method accurately measures body composition in weight-stable subjects. This study validates the use of BIA to measure change in body composition. Twelve obese females underwent weight loss at a mean rate of 1.16 kg/wk. Body composition was measured by deuterium oxide dilution (D2O), BIA, and skinfold anthropometry (SFA) at baseline and at 5% decrements in weight. Highly significant correlations were obtained between D2O and BIA (r = 0.971) and between D2O and SFA (r = 0.932). Overall, BIA predicted change in fat-free mass with greater accuracy (to 0.4 kg) and precision (+/- 1.28 kg) than did anthropometry (to 0.8 kg and +/- 2.58 kg, respectively). We conclude that BIA is a useful clinical method for measuring change in body composition

  15. Sm isotope composition and Sm/Eu ratio determination in an irradiated 153Eu sample by ion exchange chromatography-quadrupole inductively coupled plasma mass spectrometry combined with double spike isotope dilution technique

    International Nuclear Information System (INIS)

    Bourgeois, M.; Isnard, H.; Gourgiotis, A.; Stadelmann, G.; Gautier, C.; Mialle, S.; Nonell, A.; Chartier, F.

    2011-01-01

    Within the framework of the research undertaken by the French Atomic Energy Commission on transmutation of long-lived radionuclides, targets of highly enriched actinides and fission products were irradiated in the fast neutron reactor Phenix. Precise and accurate measurements of the isotopic and elemental composition of the enriched elements are therefore required. In order to obtain the uncertainties of several per mil and to reduce handling time and exposure to analyst on radioactive material, the on-line coupling of ion exchange chromatography with quadrupole inductively coupled plasma mass spectrometry has been associated with the technique of the double spike isotope dilution. We present in this paper the results obtained on an irradiated sample of Europium oxide powder (enriched at 99.13% in 153 Eu). After irradiation of around 5 mg of Eu 2 O 3 powder the theoretical calculations predict the formation of several micrograms of gadolinium and samarium isotopes. In relation to the very high activity of the sample after irradiation and the very low quantity of Sm formed, the on-line ion exchange chromatography separation of Gd, Sm and Eu before Sm isotope ratio measurements has been developed for the quantification of the 152 Sm/ 153 Eu ratio. These on-line measurements were associated with the double spike isotope dilution technique after calibration of a 147 Sm/ 151 Eu spike solution. The external reproducibility of Sm isotopic ratios was determined to be around 0.5% (2 σ) resulting in a final uncertainty on the 152 Sm/ 153 Eu ratio of around 1% (2 σ). These on-line measurements present therefore a robust and high-throughput alternative to the thermal-ionisation mass spectrometry technique used so far in combination with off-line chromatographic separation, particularly in nuclear applications where characterisation of high activity sample solutions is required. (authors)

  16. Instrumentation for mass spectrometry: 1997

    Energy Technology Data Exchange (ETDEWEB)

    McLuckey, S.A.

    1997-08-01

    All mass spectrometry experiments involve the manipulation of material, an interface with the mass spectrometer, ionization, ion manipulation/analysis, detection and data collection/reduction. Each of these elements involve instrumentation. The wide range of species now amenable to mass spectrometry and the diverse areas of physical science in which it plays a role have led to a seemingly unlimited array of instrumental combinations. However, only a limited number of mass analyzers, and their combinations, dominate. The dominant analyzers include time-of-flight, Fourier transform ion cyclotron resonance, the Paul trap, the mass filter, and the sector mass spectrometer. Why there are so few (or so many, depending upon one`s point of view) can be understood upon consideration of a set of mass analyzer figures of merit. These include mass resolution, mass accuracy, mass range, dynamic range, abundance sensitivity, precision, efficiency, speed, MS{sup n} capability, compatibility with the ionizer, cost, and size. The most appropriate form of mass spectrometry is determined by the priorities of the particular measurement placed on the various mass analyzer characteristics and the relative strengths of the analyzers in meeting the requirements. Each of the analyzer types has a unique set of figures of merit that makes it optimally suited for particular applications. This paper discusses these figures of merit, provides data illustrating recent developments for each analyzer type, and gives the figures of merit of each type of analyzer as they stand in 1997. 101 refs., 24 figs.

  17. Novel two-step laser ablation and ionization mass spectrometry (2S-LAIMS) of actor-spectator ice layers: Probing chemical composition of D2O ice beneath a H2O ice layer

    International Nuclear Information System (INIS)

    Yang, Rui; Gudipati, Murthy S.

    2014-01-01

    In this work, we report for the first time successful analysis of organic aromatic analytes imbedded in D 2 O ices by novel infrared (IR) laser ablation of a layered non-absorbing D 2 O ice (spectator) containing the analytes and an ablation-active IR-absorbing H 2 O ice layer (actor) without the analyte. With these studies we have opened up a new method for the in situ analysis of solids containing analytes when covered with an IR laser-absorbing layer that can be resonantly ablated. This soft ejection method takes advantage of the tenability of two-step infrared laser ablation and ultraviolet laser ionization mass spectrometry, previously demonstrated in this lab to study chemical reactions of polycyclic aromatic hydrocarbons (PAHs) in cryogenic ices. The IR laser pulse tuned to resonantly excite only the upper H 2 O ice layer (actor) generates a shockwave upon impact. This shockwave penetrates the lower analyte-containing D 2 O ice layer (spectator, a non-absorbing ice that cannot be ablated directly with the wavelength of the IR laser employed) and is reflected back, ejecting the contents of the D 2 O layer into the vacuum where they are intersected by a UV laser for ionization and detection by a time-of-flight mass spectrometer. Thus, energy is transmitted from the laser-absorbing actor layer into the non-absorbing spectator layer resulting its ablation. We found that isotope cross-contamination between layers was negligible. We also did not see any evidence for thermal or collisional chemistry of PAH molecules with H 2 O molecules in the shockwave. We call this “shockwave mediated surface resonance enhanced subsurface ablation” technique as “two-step laser ablation and ionization mass spectrometry of actor-spectator ice layers.” This method has its roots in the well-established MALDI (matrix assisted laser desorption and ionization) method. Our method offers more flexibility to optimize both the processes—ablation and ionization. This new technique

  18. Novel two-step laser ablation and ionization mass spectrometry (2S-LAIMS) of actor-spectator ice layers: Probing chemical composition of D{sub 2}O ice beneath a H{sub 2}O ice layer

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rui, E-mail: ryang73@ustc.edu; Gudipati, Murthy S., E-mail: gudipati@jpl.nasa.gov [Science Division, Jet Propulsion Laboratory, California Institute of Technology, Mail Stop 183-301, 4800 Oak Grove Drive, Pasadena, California 91109 (United States)

    2014-03-14

    In this work, we report for the first time successful analysis of organic aromatic analytes imbedded in D{sub 2}O ices by novel infrared (IR) laser ablation of a layered non-absorbing D{sub 2}O ice (spectator) containing the analytes and an ablation-active IR-absorbing H{sub 2}O ice layer (actor) without the analyte. With these studies we have opened up a new method for the in situ analysis of solids containing analytes when covered with an IR laser-absorbing layer that can be resonantly ablated. This soft ejection method takes advantage of the tenability of two-step infrared laser ablation and ultraviolet laser ionization mass spectrometry, previously demonstrated in this lab to study chemical reactions of polycyclic aromatic hydrocarbons (PAHs) in cryogenic ices. The IR laser pulse tuned to resonantly excite only the upper H{sub 2}O ice layer (actor) generates a shockwave upon impact. This shockwave penetrates the lower analyte-containing D{sub 2}O ice layer (spectator, a non-absorbing ice that cannot be ablated directly with the wavelength of the IR la