WorldWideScience

Sample records for volume limited sample

  1. Local Environmental Dependence of Galaxy Properties in a Volume-Limited Sample of Main Galaxies

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Using a volume-limited sample of Main Galaxies from SDSS Data Release 5, we investigate the dependence of galaxy properties on local environment. For each galaxy, a local three-dimensional density is calculated. We find that the galaxy morphological type depends strongly on the local environment: galaxies in dense environments have predominantly early type morphologies. Galaxy colors have only a weak dependence on the environment. This puts an important constraint on the process of galaxy formation.

  2. Clustering properties of a type-selected volume-limited sample of galaxies in the CFHTLS

    CERN Document Server

    McCracken, H J; Mellier, Y; Bertin, E; Guzzo, L; Arnouts, S; Le Fèvre, O; Zamorani, G

    2007-01-01

    (abridged) We present an investigation of the clustering of i'AB<24.5 galaxies in the redshift interval 0.2volume-limited galaxy catalogues. We study the dependence of the amplitude and slope of the galaxy correlation function on absolute B-band rest-frame luminosity, redshift and best-fitting spectral type. We find: 1. The comoving correlation length for all galaxies decreases steadily from z~0.3 to z~1. 2. At all redshifts and luminosities, galaxies with redder rest-frame colours have clustering amplitudes between two and three times higher than bluer ones. 3. For bright red and blue galaxies, the clustering amplitude is invariant with redshift. 4. At z~0.5, less luminous galaxies have higher clustering amplitudes of around 6 h-1 Mpc. 5. The relative bias between galaxies with red and blue rest-frame colours increases gradually towards fainter absolute magnitud...

  3. The properties of a large volume-limited sample of face-on low surface brightness disk galaxies

    Institute of Scientific and Technical Information of China (English)

    Guo-Hu Zhong; Yan-Chun Liang; Feng-Shan Liu; Francois Hammer; Karen Disseau; Li-Cai Deng

    2012-01-01

    We select a large volume-limited sample of low surface brightness galaxies (LSBGs,2021) to investigate in detail their statistical properties and their differences from high surface brightness galaxies (HSBGs,3639).The distributions of stellar masses of LSBGs and HSBGs are nearly the same and they have the same median values.Thus this volume-limited sample has good completeness and is further removed from the effect of stellar masses on their other properties when we compare LSBGs to HSBGs.We found that LSBGs tend to have lower stellar metallicities and lower effective dust attenuations,indicating that they have lower dust than HSBGs.The LSBGs have relatively higher stellar mass-to-light ratios,higher gas fractions,lower star forming rates (SFRs),and lower specific SFRs than HSBGs.Moreover,with the decreasing surface brightness,gas fraction increases,but the SFRs and specific SFRs decrease rapidly for the sample galaxies.This could mean that the star formation histories between LSBGs and HSBGs are different,and HSBGs may have stronger star forming activities than LSBGs.

  4. Revisiting the Lick Observatory Supernova Search Volume-Limited Sample: Updated Classifications and Revised Stripped-envelope Supernova Fractions

    CERN Document Server

    Shivvers, Isaac; Zheng, Weikang; Filippenko, Alexei V; Silverman, Jeffrey M; Liu, Yuqian; Matheson, Thomas; Pastorello, Andrea; Graur, Or; Foley, Ryan J; Chornock, Ryan; Smith, Nathan; Leaman, Jesse; Benetti, Stefano

    2016-01-01

    We re-examine the classifications of supernovae (SNe) presented in the Lick Observatory Supernova Search (LOSS) volume-limited sample with a focus on the stripped-envelope SNe. The LOSS volumetric sample, presented by Leaman et al. (2011) and Li et al. (2011b), was calibrated to provide meaningful measurements of SN rates in the local universe; the results presented therein continue to be used for comparisons to theoretical and modeling efforts. Many of the objects from the LOSS sample were originally classified based upon only a small subset of the data now available, and recent studies have both updated some subtype distinctions and improved our ability to perform robust classifications, especially for stripped-envelope SNe. We re-examine the spectroscopic classifications of all events in the LOSS volumetric sample (180 SNe and SN impostors) and update them if necessary. We discuss the populations of rare objects in our sample including broad-lined Type Ic SNe, Ca-rich SNe, SN 1987A-like events (we identify...

  5. Mg II Absorption Characteristics of a Volume-Limited Sample of Galaxies at z ~ 0.1

    Science.gov (United States)

    Barton, Elizabeth J.; Cooke, Jeff

    2009-12-01

    We present an initial survey of Mg II absorption characteristics in the halos of a carefully constructed, volume-limited subsample of galaxies embedded in the spectroscopic part of the Sloan Digital Sky Survey (SDSS). We observed quasars near sightlines to 20 low-redshift (z ~ 0.1), luminous (M r + 5log h background quasar within a projected 75 h -1 kpc of its center, although we preferentially sample galaxies with lower impact parameters and slightly more star formation within this range. Of the observed systems, six exhibit strong (W eq(2796) >= 0.3 Å) Mg II absorption at the galaxy's redshift, six systems have upper limits which preclude strong Mg II absorption, while the remaining observations rule out very strong (W eq(2796) >= 1-2 Å) absorption. The absorbers fall at higher impact parameters than many non-absorber sightlines, indicating a covering fraction fc lsim 0.4 for >=0.3 Å absorbers at z ~ 0.1, even at impact parameters Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  6. A volume-limited sample of X-ray galaxy groups and clusters - I. Radial entropy and cooling time profiles

    CERN Document Server

    Panagoulia, Electra; Sanders, Jeremy

    2013-01-01

    We present the first results of our study of a sample of 101 X-ray galaxy groups and clusters, which is volume-limited in each of three X-ray luminosity bins. The aim of this work is to study the properties of the innermost ICM in the cores of our groups and clusters, and to determine the effect of non-gravitational processes, such as active galactic nucleus (AGN) feedback, on the ICM. The entropy of the ICM is of special interest, as it bears the imprint of the thermal history of a cluster, and it also determines a cluster's global properties. Entropy profiles can therefore be used to examine any deviations from cluster self-similarity, as well as the effects of feedback on the ICM. We find that the entropy profiles are well-fitted by a simple powerlaw model, of the form $K(r) = \\alpha\\times(r/100 \\rm{kpc})^{\\beta}$, where $\\alpha$ and $\\beta$ are constants. We do not find evidence for the existence of an "entropy floor", i.e. our entropy profiles do not flatten out at small radii, as suggested by some previ...

  7. Capillary ion chromatography with on-column focusing for ultra-trace analysis of methanesulfonate and inorganic anions in limited volume Antarctic ice core samples.

    Science.gov (United States)

    Rodriguez, Estrella Sanz; Poynter, Sam; Curran, Mark; Haddad, Paul R; Shellie, Robert A; Nesterenko, Pavel N; Paull, Brett

    2015-08-28

    Preservation of ionic species within Antarctic ice yields a unique proxy record of the Earth's climate history. Studies have been focused until now on two proxies: the ionic components of sea salt aerosol and methanesulfonic acid. Measurement of the all of the major ionic species in ice core samples is typically carried out by ion chromatography. Former methods, whilst providing suitable detection limits, have been based upon off-column preconcentration techniques, requiring larger sample volumes, with potential for sample contamination and/or carryover. Here, a new capillary ion chromatography based analytical method has been developed for quantitative analysis of limited volume Antarctic ice core samples. The developed analytical protocol applies capillary ion chromatography (with suppressed conductivity detection) and direct on-column sample injection and focusing, thus eliminating the requirement for off-column sample preconcentration. This limits the total sample volume needed to 300μL per analysis, allowing for triplicate sample analysis with anions, including fluoride, methanesulfonate, chloride, sulfate and nitrate anions. Application to composite ice-core samples is demonstrated, with coupling of the capillary ion chromatograph to high resolution mass spectrometry used to confirm the presence and purity of the observed methanesulfonate peak.

  8. The Atlas3D project -- I. A volume-limited sample of 260 nearby early-type galaxies: science goals and selection criteria

    CERN Document Server

    Cappellari, Michele; Krajnovic, Davor; McDermid, Richard M; Scott, Nicholas; Kleijn, G A Verdoes; Young, Lisa M; Alatalo, Katherine; Bacon, R; Blitz, Leo; Bois, Maxime; Bournaud, Frederic; Bureau, M; Davies, Roger L; Davis, Timothy A; de Zeeuw, P T; Duc, Pierre-Alain; Khochfar, Sadegh; Kuntschner, Harald; Lablanche, Pierre-Yves; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Serra, Paolo; Weijmans, Anne-Marie

    2010-01-01

    The Atlas3D project is a multi-wavelength survey combined with a theoretical modeling effort. The observations span from the radio to the millimeter and optical, and provide multi-colour imaging, two-dimensional kinematics of the atomic (HI), molecular (CO) and ionized gas (Hbeta, [OIII] and [NI]), together with the kinematics and population of the stars (Hbeta, Fe5015 and Mgb), for a carefully selected, volume-limited (1.16*10^5 Mpc^3) sample of 260 early-type (elliptical E and lenticular S0) galaxies (ETGs). The models include semi-analytic, N-body binary mergers and cosmological simulations of galaxy formation. Here we present the science goals for the project and introduce the galaxy sample and the selection criteria. The sample consists of nearby (D6*10^9 M_Sun). We analyze possible selection biases and we conclude that the parent sample is essentially complete and statistically representative of the nearby galaxy population. We present the size-luminosity relation for the spirals and ETGs and show that ...

  9. The Cool ISM in Elliptical Galaxies. II. Gas Content in the Volume - Limited Sample and Results from the Combined Elliptical and Lenticular Surveys

    CERN Document Server

    Welch, Gary A; Young, Lisa M

    2010-01-01

    We report new observations of atomic and molecular gas in a volume limited sample of elliptical galaxies. Combining the elliptical sample with an earlier and similar lenticular one, we show that cool gas detection rates are very similar among low luminosity E and SO galaxies but are much higher among luminous S0s. Using the combined sample we revisit the correlation between cool gas mass and blue luminosity which emerged from our lenticular survey, finding strong support for previous claims that the molecular gas in ellipticals and lenticulars has different origins. Unexpectedly, however, and contrary to earlier claims, the same is not true for atomic gas. We speculate that both the AGN feedback and merger paradigms might offer explanations for differences in detection rates, and might also point towards an understanding of why the two gas phases could follow different evolutionary paths in Es and S0s. Finally we present a new and puzzling discovery concerning the global mix of atomic and molecular gas in ear...

  10. Integrated Spectroscopy of the Herschel Reference Survey. The spectral line properties of a volume-limited, K-band selected sample of nearby galaxies

    CERN Document Server

    Boselli, A; Cortese, L; Gavazzi, G; Buat, V

    2012-01-01

    We present long-slit integrated spectroscopy of 238 late-type galaxies belonging to the Herschel Reference Survey, a volume limited sample representative of the nearby universe. This sample has a unique legacy value since ideally defined for any statistical study of the multifrequency properties of galaxies spanning a large range in morphological type and luminosity. The spectroscopic observations cover the spectral range 3600-6900 A at a resolution R ~ 1000 and are thus suitable for separating the underlying absorption from the emission of the Hbeta line as well as the two [NII] lines from the Halpha emission. We measure the fluxes and the equivalent widths of the strongest emission lines ([OII], Hbeta, [OIII], [NII], Halpha, and [SII]). The data are used to study the distribution of the equivalent width of all the emission lines, of the Balmer decrement C(Hbeta) and of the observed underlying Balmer absorption under Hbeta in this sample. Combining these new spectroscopic data with those available at other f...

  11. Halo Gas and Galaxy Disk Kinematics of a Volume-Limited Sample of MgII Absorption-Selected Galaxies at z~0.1

    CERN Document Server

    Kacprzak, G G; Barton, E J; Cooke, J

    2011-01-01

    We have directly compared MgII halo gas kinematics to the rotation velocities derived from emission/absorption lines of the associated host galaxies. Our 0.096volume-limited sample comprises 13 ~L* galaxies, with impact parameters of 12-90 kpc from background quasars sight-lines, associated with 11 MgII absorption systems with MgII equivalent widths 0.3< W_r(2796)<2.3A. For only 5/13 galaxies, the absorption resides to one side of the galaxy systemic velocity and trends to align with one side of the galaxy rotation curve. The remainder have absorption that spans both sides of the galaxy systemic velocity. These results differ from those at z~0.5, where 74% of the galaxies have absorption residing to one side of the galaxy systemic velocity. For all the z~0.1 systems, simple extended disk-like rotation models fail to reproduce the full MgII velocity spread, implying other dynamical processes contribute to the MgII kinematics. In fact 55% of the galaxies are "counter-rotating" with respect ...

  12. Limiting Spectral Distribution of Sample Autocovariance Matrices

    CERN Document Server

    Basak, Anirban; Sen, Sanchayan

    2011-01-01

    The empirical spectral distribution (ESD) of the sample variance covariance matrix of i.i.d. observations under suitable moment conditions converges almost surely as the dimension tends to infinity. The limiting spectral distribution (LSD) is universal and is known in closed form with support [0, 4]. In this article we show that the ESD of the sample autocovariance matrix converges as the dimension increases, when the time series is a linear process with reasonable restriction on the coefficients. This limit does not depend on the distribution of the underlying driving i.i.d. sequence but in contrast to the sample variance covariance matrix, its support is unbounded. The limit moments are certain functions of the autocovariances. This limit is inconsistent in the sense that it does not coincide with the spectral distribution of the theoretical autocovariance matrix. However, if we consider a suitably tapered version of the autocovariance matrix, then its LSD also exists and is consistent. We also discuss the ...

  13. Metabolic profiling of ultrasmall sample volumes with GC/MS: From microliter to nanoliter samples

    NARCIS (Netherlands)

    Koek, M.M.; Bakels, F.; Engel, W.; Maagdenberg, A. van den; Ferrari, M.D.; Coulier, L.; Hankemeier, T.

    2010-01-01

    Profiling of metabolites is increasingly used to study the functioning of biological systems. For some studies the volume of available samples is limited to only a few microliters or even less, for fluids such as cerebrospinal fluid (CSF) of small animals like mice or the analysis of individual oocy

  14. Volume Ray Casting with Peak Finding and Differential Sampling

    KAUST Repository

    Knoll, A.

    2009-11-01

    Direct volume rendering and isosurfacing are ubiquitous rendering techniques in scientific visualization, commonly employed in imaging 3D data from simulation and scan sources. Conventionally, these methods have been treated as separate modalities, necessitating different sampling strategies and rendering algorithms. In reality, an isosurface is a special case of a transfer function, namely a Dirac impulse at a given isovalue. However, artifact-free rendering of discrete isosurfaces in a volume rendering framework is an elusive goal, requiring either infinite sampling or smoothing of the transfer function. While preintegration approaches solve the most obvious deficiencies in handling sharp transfer functions, artifacts can still result, limiting classification. In this paper, we introduce a method for rendering such features by explicitly solving for isovalues within the volume rendering integral. In addition, we present a sampling strategy inspired by ray differentials that automatically matches the frequency of the image plane, resulting in fewer artifacts near the eye and better overall performance. These techniques exhibit clear advantages over standard uniform ray casting with and without preintegration, and allow for high-quality interactive volume rendering with sharp C0 transfer functions. © 2009 IEEE.

  15. Rock Sample Destruction Limits for the Mars Sample Return Mission

    Science.gov (United States)

    Weiss, D. K.; Budney, C. J.; Shiraishi, L.; Klein, K.; Gilbert, J.

    2012-12-01

    Sample return missions, including the proposed Mars Sample Return (MSR) mission, propose to collect core samples from scientifically valuable sites on Mars. These core samples would undergo extreme forces during the drilling process, and during the reentry process if the Earth Entry Vehicle (EEV) performs a hard landing on Earth. Because of the foreseen damage to the cores, it is important to evaluate each core for rock quality. However, because no planetary core sample return mission has yet been conducted, it remains unclear as to how to assess the cores for rock quality. In this report, we describe the development of a metric designed to quantitatively assess the quality of the rock cores returned from MSR. We report on the process by which we tested the metric on core samples of Mars analogue materials, and the effectiveness of the core assessment metric (CAM) in assessing rock core quality before and after the cores were subjected to shocking (g forces representative of an EEV landing). Mars-analogue Basalt rock core. Cores like this one are being used to develop a metric with which to assess rock quality before and after shock-testing. The sample canister that houses the cores during shock-testing. SolidWorks design by James Gilbert.

  16. The infinite volume limit of Ford's alpha model

    CERN Document Server

    Stefansson, Sigurdur Orn

    2009-01-01

    We prove the existence of a limit of the finite volume probability measures generated by tree growth rules in Ford's alpha model of phylogenetic trees. The limiting measure is shown to be concentrated on the set of trees consisting of exactly one infinite spine with finite, identically and independently distributed outgrowths.

  17. Irregular sampling for multivariate band-limited functions

    Institute of Scientific and Technical Information of China (English)

    SUN; Wenchang(孙文昌); ZHOU; Xingwei(周性伟)

    2002-01-01

    In this paper, we present some new algorithms to reconstruct multivariate band-limited functionsfrom irregular sampled values, which allow more arbitrary sampling points and lower sampling densities thanknown results.

  18. On Third-Order Limiter Functions for Finite Volume Methods

    CERN Document Server

    Schmidtmann, Birte; Torrilhon, Manuel

    2014-01-01

    In this article, we propose a finite volume limiter function for a reconstruction on the three-point stencil. Compared to classical limiter functions in the MUSCL framework, which yield $2^{\\text{nd}}$-order accuracy, the new limiter is $3^\\text{rd}$-order accurate for smooth solutions. In an earlier work, such a $3^\\text{rd}$-order limiter function was proposed and showed successful results [2]. However, it came with unspecified parameters. We close this gap by giving information on these parameters.

  19. Limited streamer chambers for the Large Volume Detector

    NARCIS (Netherlands)

    Anzivino, G.; Bianco, S.; Casaccia, R.; Cindolo, F.; Daniello, L.; Felici, M. De; Enorini, M.; Fabbri, D.; Fabbri, F.L.; Giardoni, M.; Laakso, I.; Lindozzi, M.; Pallante, E.; Passamonti, L.; Russo, V.; Ventura, M.; Votano, L.; Zallo, A.; Bari, G.; Bruni, G.; Cara Romeo, G.; Contin, A.; Papa, C. Del; Iacobucci, G.; Maccarrone, G.; Mencarini, D.; Kania, R.; Sartorelli, G.; Qazi, N.I.; Sarwar, S.; Mao, C.S.; Wu, Y.R.

    1991-01-01

    The tracking system of the Large Volume Detector, an underground experiment to study muons and nutrino astronomy, will use ~15000 limited streamer chambers. We describe a comparison between the standard binary mixture (30% argon + 70% isobutane) and a low-hydrocarbon ternary mixture (2% argon + 10%

  20. Limited streamer chambers for the Large Volume Detector

    NARCIS (Netherlands)

    Anzivino, G.; Bianco, S.; Casaccia, R.; Cindolo, F.; Daniello, L.; Felici, M. De; Enorini, M.; Fabbri, D.; Fabbri, F.L.; Giardoni, M.; Laakso, I.; Lindozzi, M.; Pallante, E.; Passamonti, L.; Russo, V.; Ventura, M.; Votano, L.; Zallo, A.; Bari, G.; Bruni, G.; Cara Romeo, G.; Contin, A.; Papa, C. Del; Iacobucci, G.; Maccarrone, G.; Mencarini, D.; Kania, R.; Sartorelli, G.; Qazi, N.I.; Sarwar, S.; Mao, C.S.; Wu, Y.R.

    1991-01-01

    The tracking system of the Large Volume Detector, an underground experiment to study muons and nutrino astronomy, will use ~15000 limited streamer chambers. We describe a comparison between the standard binary mixture (30% argon + 70% isobutane) and a low-hydrocarbon ternary mixture (2% argon + 10%

  1. TRU Waste Sampling Program: Volume I. Waste characterization

    Energy Technology Data Exchange (ETDEWEB)

    Clements, T.L. Jr.; Kudera, D.E.

    1985-09-01

    Volume I of the TRU Waste Sampling Program report presents the waste characterization information obtained from sampling and characterizing various aged transuranic waste retrieved from storage at the Idaho National Engineering Laboratory and the Los Alamos National Laboratory. The data contained in this report include the results of gas sampling and gas generation, radiographic examinations, waste visual examination results, and waste compliance with the Waste Isolation Pilot Plant-Waste Acceptance Criteria (WIPP-WAC). A separate report, Volume II, contains data from the gas generation studies.

  2. Variance in brain volume with advancing age: implications for defining the limits of normality.

    Directory of Open Access Journals (Sweden)

    David Alexander Dickie

    Full Text Available Statistical models of normal ageing brain tissue volumes may support earlier diagnosis of increasingly common, yet still fatal, neurodegenerative diseases. For example, the statistically defined distribution of normal ageing brain tissue volumes may be used as a reference to assess patient volumes. To date, such models were often derived from mean values which were assumed to represent the distributions and boundaries, i.e. percentile ranks, of brain tissue volume. Since it was previously unknown, the objective of the present study was to determine if this assumption was robust, i.e. whether regression models derived from mean values accurately represented the distributions and boundaries of brain tissue volume at older ages.We acquired T1-w magnetic resonance (MR brain images of 227 normal and 219 Alzheimer's disease (AD subjects (aged 55-89 years from publicly available databanks. Using nonlinear regression within both samples, we compared mean and percentile rank estimates of whole brain tissue volume by age.In both the normal and AD sample, mean regression estimates of brain tissue volume often did not accurately represent percentile rank estimates (errors=-74% to 75%. In the normal sample, mean estimates generally underestimated differences in brain volume at percentile ranks below the mean. Conversely, in the AD sample, mean estimates generally underestimated differences in brain volume at percentile ranks above the mean. Differences between ages at the 5(th percentile rank of normal subjects were ~39% greater than mean differences in the AD subjects.While more data are required to make true population inferences, our results indicate that mean regression estimates may not accurately represent the distributions of ageing brain tissue volumes. This suggests that percentile rank estimates will be required to robustly define the limits of brain tissue volume in normal ageing and neurodegenerative disease.

  3. Repetitive Cyclic Potentiodynamic Polarization Scan Results for Reduced Sample Volume Testing

    Energy Technology Data Exchange (ETDEWEB)

    LaMothe, Margaret E. [Washington River Protection Solutions, Richland, WA (United States)

    2016-03-15

    This report is the compilation of data gathered after repetitively testing simulated tank waste and a radioactive tank waste sample using a cyclic potentiodynamic polarization (CPP) test method to determine corrosion resistance of metal samples. Electrochemistry testing of radioactive tank samples is often used to assess the corrosion susceptibility and material integrity of waste tank steel. Repetitive testing of radiological tank waste is occasionally requested at 222-S Laboratory due to the limited volume of radiological tank sample received for testing.

  4. Precise small volume sample handling for capillary electrophoresis.

    Science.gov (United States)

    Mozafari, Mona; Nachbar, Markus; Deeb, Sami El

    2015-09-03

    Capillary electrophoresis is one of the most important analytical techniques. Although the injected sample volume in capillary electrophoresis is only in the nanoliter range, most commercial CE-instruments need approximately 50 μL of the sample in the injection vial to perform the analysis. Hence, in order to fully profit from the low injection volumes, smaller vial volumes are required. Thus experiments were performed using silicone oil which has higher density than water (1.09 g/mL) to replace sample dead volume in the vial. The results were compared to those performed without using the silicone oil in the sample vial. As an example five standard proteins namely beta-lactoglobulin, BSA, HSA, Myoglobin and Ovalbumin, and one of the coagulation cascade involved proteins called vitonectin were investigated using capillary electrophoresis. Mobility ratios and peak areas were compared. However no significant changes were observed (RSDs% for mobility ratios and peak areas were better than 0.9% and 5.8% respectively). Afterwards an affinity capillary electrophoresis method was used to investigate the interactions of two proteins, namely HSA and vitronectin, with three ligands namely enoxaparin sodium, unfractionated heparin and pentosan polysulfate sodium (PPS). Mobility shift precision results showed that the employment of the filling has no noticeable effect on any of the protein-ligand interactions. Using a commercial PrinCE instrument and an autosampler the required sample volume is reduced down to 10 μL, and almost this complete volume can be subsequently injected during repeated experiments. This article is protected by copyright. All rights reserved.

  5. A distance limited method for sampling downed coarse woody debris

    Science.gov (United States)

    Jeffrey H. Gove; Mark J. Ducey; Harry T. Valentine; Michael S. Williams

    2012-01-01

    A new sampling method for down coarse woody debris is proposed based on limiting the perpendicular distance from individual pieces to a randomly chosen sample point. Two approaches are presented that allow different protocols to be used to determine field measurements; estimators for each protocol are also developed. Both protocols are compared via simulation against...

  6. Determination of cell electroporation in small-volume samples.

    Science.gov (United States)

    Saulis, Gintautas; Praneviciŭte, Rita

    2007-01-01

    Expose of cells to electric field pulses increases the cell membrane permeability. Intracellular potassium ions leak out of the cells through aqueous pores created in the membrane. This release is used here for the determination of the fraction of electroporated cells. To determine cell membrane electroporation in small-volume samples (40-50 miacrol), mini both potassium ion-selective and reference electrodes, with tip diameters of 1-1.5 mm and minimum immersion depths of 1 mm, were utilized. The obtained calibration graph was linear within the concentration range 0.2-100 mM. The slope was 50-51 and 53-56 mV per concentration order at 10-11 and 19-21 degrees C, respectively. Detection limit of the electrode was determined to be 0.05-0.08 mM, however, it was possible to work down to concentrations in the range of 0.01 mM. Experiments have been carried out on human erythrocytes exposed to a square-wave electric pulse with the duration of 0.1-2 ms. The extracellular potassium concentrations were in the range between 0.04-0.08 mM (intact cells) and 3-5 mM (100% electroporation). The obtained dependences of the fraction of electroporated cells on the pulse intensity were of a sigmoid shape. The dependence of the pulse amplitude required to electroporate 50% of cells on the pulse duration, obtained from the release of intracellular potassium ions, coincided with the one determined from the extent of hemolysis after 24 h-incubation at low temperature.

  7. Influence of volume of sample processed on detection of Chlamydia trachomatis in urogenital samples by PCR.

    OpenAIRE

    Goessens, Wil; Kluytmans, Jan; Toom, N.; van Rijsoort-Vos, T H; Stolz, Ernst; Verbrugh, Henri; Quint, Wim; Niesters, Bert

    1995-01-01

    textabstractIn the present study, it was demonstrated that the sensitivity of the PCR for the detection of Chlamydia trachomatis is influenced by the volume of the clinical sample which is processed in the PCR. An adequate sensitivity for PCR was established by processing at least 4%, i.e., 80 microliters, of the clinical sample volume per PCR. By using this preparation procedure, 1,110 clinical samples were evaluated by PCR and by cell culture, and results were compared. After discordant ana...

  8. Pulsed Direct Current Electrospray: Enabling Systematic Analysis of Small Volume Sample by Boosting Sample Economy.

    Science.gov (United States)

    Wei, Zhenwei; Xiong, Xingchuang; Guo, Chengan; Si, Xingyu; Zhao, Yaoyao; He, Muyi; Yang, Chengdui; Xu, Wei; Tang, Fei; Fang, Xiang; Zhang, Sichun; Zhang, Xinrong

    2015-11-17

    We had developed pulsed direct current electrospray ionization mass spectrometry (pulsed-dc-ESI-MS) for systematically profiling and determining components in small volume sample. Pulsed-dc-ESI utilized constant high voltage to induce the generation of single polarity pulsed electrospray remotely. This method had significantly boosted the sample economy, so as to obtain several minutes MS signal duration from merely picoliter volume sample. The elongated MS signal duration enable us to collect abundant MS(2) information on interested components in a small volume sample for systematical analysis. This method had been successfully applied for single cell metabolomics analysis. We had obtained 2-D profile of metabolites (including exact mass and MS(2) data) from single plant and mammalian cell, concerning 1034 components and 656 components for Allium cepa and HeLa cells, respectively. Further identification had found 162 compounds and 28 different modification groups of 141 saccharides in a single Allium cepa cell, indicating pulsed-dc-ESI a powerful tool for small volume sample systematical analysis.

  9. The effects of different syringe volume, needle size and sample volume on blood gas analysis in syringes washed with heparin

    Science.gov (United States)

    Küme, Tuncay; Şişman, Ali Rıza; Solak, Ahmet; Tuğlu, Birsen; Çinkooğlu, Burcu; Çoker, Canan

    2012-01-01

    Introductıon: We evaluated the effect of different syringe volume, needle size and sample volume on blood gas analysis in syringes washed with heparin. Materials and methods: In this multi-step experimental study, percent dilution ratios (PDRs) and final heparin concentrations (FHCs) were calculated by gravimetric method for determining the effect of syringe volume (1, 2, 5 and 10 mL), needle size (20, 21, 22, 25 and 26 G) and sample volume (0.5, 1, 2, 5 and 10 mL). The effect of different PDRs and FHCs on blood gas and electrolyte parameters were determined. The erroneous results from nonstandardized sampling were evaluated according to RiliBAK’s TEa. Results: The increase of PDRs and FHCs was associated with the decrease of syringe volume, the increase of needle size and the decrease of sample volume: from 2.0% and 100 IU/mL in 10 mL-syringe to 7.0% and 351 IU/mL in 1 mL-syringe; from 4.9% and 245 IU/mL in 26G to 7.6% and 380 IU/mL in 20 G with combined 1 mL syringe; from 2.0% and 100 IU/mL in full-filled sample to 34% and 1675 IU/mL in 0.5 mL suctioned sample into 10 mL-syringe. There was no statistical difference in pH; but the percent decreasing in pCO2, K+, iCa2+, iMg2+; the percent increasing in pO2 and Na+ were statistical significance compared to samples full-filled in syringes. The all changes in pH and pO2 were acceptable; but the changes in pCO2, Na+, K+ and iCa2+ were unacceptable according to TEa limits except fullfilled-syringes. Conclusions: The changes in PDRs and FHCs due nonstandardized sampling in syringe washed with liquid heparin give rise to erroneous test results for pCO2 and electrolytes. PMID:22838185

  10. Comprehensive workflow for wireline fluid sampling in an unconsolidated formations utilizing new large volume sampling equipment

    Energy Technology Data Exchange (ETDEWEB)

    Kvinnsland, S.; Brun, M. [TOTAL EandP Norge (Norway); Achourov, V.; Gisolf, A. [Schlumberger (Canada)

    2011-07-01

    Precise and accurate knowledge of fluid properties is essential in unconsolidated formations to the design of production facilities. Wireline formation testers (WFT) have a wide range of applications and the latest WFT can be used to define fluid properties in the wells drilled with oil based mud (OBM) by acquiring PVT and large volume samples. To use these technologies, a comprehensive workflow has to be implemented and the aim of this paper is to present such a workflow. A sampling was conducted in highly unconsolidated sand saturated with biodegradable fluid in the Hild filed in the North Sea. Results showed the use of comprehensive workflow to be successful in obtaining large volume samples with the contamination level below 1%. Oil was precisely characterized thanks to these samples and design updates to the project were made possible. This paper highlighted that the use of the latest WFT technologies can help better characterize fluids in unconsolidated formations and thus optimize production facilities design.

  11. Influence of volume of sample processed on detection of Chlamydia trachomatis in urogenital samples by PCR

    NARCIS (Netherlands)

    Goessens, W H; Kluytmans, J A; den Toom, N; van Rijsoort-Vos, T H; Niesters, B G; Stolz, E; Verbrugh, H A; Quint, W G

    In the present study, it was demonstrated that the sensitivity of the PCR for the detection of Chlamydia trachomatis is influenced by the volume of the clinical sample which is processed in the PCR. An adequate sensitivity for PCR was established by processing at least 4%, i.e., 80 microliters, of

  12. Influence of volume of sample processed on detection of Chlamydia trachomatis in urogenital samples by PCR

    NARCIS (Netherlands)

    Goessens, W H; Kluytmans, J A; den Toom, N; van Rijsoort-Vos, T H; Niesters, B G; Stolz, E; Verbrugh, H A; Quint, W G

    1995-01-01

    In the present study, it was demonstrated that the sensitivity of the PCR for the detection of Chlamydia trachomatis is influenced by the volume of the clinical sample which is processed in the PCR. An adequate sensitivity for PCR was established by processing at least 4%, i.e., 80 microliters, of t

  13. Influence of volume of sample processed on detection of Chlamydia trachomatis in urogenital samples by PCR

    NARCIS (Netherlands)

    W.H.F. Goessens (Wil); J.A.J.W. Kluytmans (Jan); N. den Toom; T.H. van Rijsoort-Vos; E. Stolz (Ernst); H.A. Verbrugh (Henri); W.G.V. Quint (Wim); H.G.M. Niesters (Bert)

    1995-01-01

    textabstractIn the present study, it was demonstrated that the sensitivity of the PCR for the detection of Chlamydia trachomatis is influenced by the volume of the clinical sample which is processed in the PCR. An adequate sensitivity for PCR was established by processing at least

  14. UNLABELED SELECTED SAMPLES IN FEATURE EXTRACTION FOR CLASSIFICATION OF HYPERSPECTRAL IMAGES WITH LIMITED TRAINING SAMPLES

    Directory of Open Access Journals (Sweden)

    A. Kianisarkaleh

    2015-12-01

    Full Text Available Feature extraction plays a key role in hyperspectral images classification. Using unlabeled samples, often unlimitedly available, unsupervised and semisupervised feature extraction methods show better performance when limited number of training samples exists. This paper illustrates the importance of selecting appropriate unlabeled samples that used in feature extraction methods. Also proposes a new method for unlabeled samples selection using spectral and spatial information. The proposed method has four parts including: PCA, prior classification, posterior classification and sample selection. As hyperspectral image passes these parts, selected unlabeled samples can be used in arbitrary feature extraction methods. The effectiveness of the proposed unlabeled selected samples in unsupervised and semisupervised feature extraction is demonstrated using two real hyperspectral datasets. Results show that through selecting appropriate unlabeled samples, the proposed method can improve the performance of feature extraction methods and increase classification accuracy.

  15. Effect of sample aliquot size on the limit of detection and reproducibility of clinical assays.

    Science.gov (United States)

    Chen, Guorong; Kobayashi, Lori; Nazarenko, Irina

    2007-11-01

    Nucleic acid amplification technologies significantly improved the limit of detection (LOD) for diagnostic assays. The ability of these assays to amplify fewer than 10 target copies of DNA or RNA imposes new requirements on the preparation of clinical samples. We report a statistical method to determine how large of an aliquot is necessary to reproducibly provide a detectable number of cells. We determined the success probability (p) based on aliquot size and sample volume. The binomial distribution, based on p and the concentration of cells in sample, was used to calculate the probability of getting no target objects in an aliquot and to determine the minimum number of objects per aliquot necessary to generate a reproducible clinical assay. The described method was applied to find a minimum aliquot volume required for a set LOD, false-negative rate (FNR), and %CV. For example, to keep FNR FNRs are 47.2% and 44.9%. This probability model is a useful tool to predict the impact of aliquot volume on the LOD and reproducibility of clinical assays. Even for samples for which pathogens are homogeneously distributed, it is theoretically impossible to collect a single pathogen consistently if the concentration of pathogen is below a certain limit.

  16. Automated force volume image processing for biological samples.

    Directory of Open Access Journals (Sweden)

    Pavel Polyakov

    Full Text Available Atomic force microscopy (AFM has now become a powerful technique for investigating on a molecular level, surface forces, nanomechanical properties of deformable particles, biomolecular interactions, kinetics, and dynamic processes. This paper specifically focuses on the analysis of AFM force curves collected on biological systems, in particular, bacteria. The goal is to provide fully automated tools to achieve theoretical interpretation of force curves on the basis of adequate, available physical models. In this respect, we propose two algorithms, one for the processing of approach force curves and another for the quantitative analysis of retraction force curves. In the former, electrostatic interactions prior to contact between AFM probe and bacterium are accounted for and mechanical interactions operating after contact are described in terms of Hertz-Hooke formalism. Retraction force curves are analyzed on the basis of the Freely Jointed Chain model. For both algorithms, the quantitative reconstruction of force curves is based on the robust detection of critical points (jumps, changes of slope or changes of curvature which mark the transitions between the various relevant interactions taking place between the AFM tip and the studied sample during approach and retraction. Once the key regions of separation distance and indentation are detected, the physical parameters describing the relevant interactions operating in these regions are extracted making use of regression procedure for fitting experiments to theory. The flexibility, accuracy and strength of the algorithms are illustrated with the processing of two force-volume images, which collect a large set of approach and retraction curves measured on a single biological surface. For each force-volume image, several maps are generated, representing the spatial distribution of the searched physical parameters as estimated for each pixel of the force-volume image.

  17. Automated Force Volume Image Processing for Biological Samples

    Science.gov (United States)

    Duan, Junbo; Duval, Jérôme F. L.; Brie, David; Francius, Grégory

    2011-01-01

    Atomic force microscopy (AFM) has now become a powerful technique for investigating on a molecular level, surface forces, nanomechanical properties of deformable particles, biomolecular interactions, kinetics, and dynamic processes. This paper specifically focuses on the analysis of AFM force curves collected on biological systems, in particular, bacteria. The goal is to provide fully automated tools to achieve theoretical interpretation of force curves on the basis of adequate, available physical models. In this respect, we propose two algorithms, one for the processing of approach force curves and another for the quantitative analysis of retraction force curves. In the former, electrostatic interactions prior to contact between AFM probe and bacterium are accounted for and mechanical interactions operating after contact are described in terms of Hertz-Hooke formalism. Retraction force curves are analyzed on the basis of the Freely Jointed Chain model. For both algorithms, the quantitative reconstruction of force curves is based on the robust detection of critical points (jumps, changes of slope or changes of curvature) which mark the transitions between the various relevant interactions taking place between the AFM tip and the studied sample during approach and retraction. Once the key regions of separation distance and indentation are detected, the physical parameters describing the relevant interactions operating in these regions are extracted making use of regression procedure for fitting experiments to theory. The flexibility, accuracy and strength of the algorithms are illustrated with the processing of two force-volume images, which collect a large set of approach and retraction curves measured on a single biological surface. For each force-volume image, several maps are generated, representing the spatial distribution of the searched physical parameters as estimated for each pixel of the force-volume image. PMID:21559483

  18. Sampling-based motion planning with reachable volumes: Theoretical foundations

    KAUST Repository

    McMahon, Troy

    2014-05-01

    © 2014 IEEE. We introduce a new concept, reachable volumes, that denotes the set of points that the end effector of a chain or linkage can reach. We show that the reachable volume of a chain is equivalent to the Minkowski sum of the reachable volumes of its links, and give an efficient method for computing reachable volumes. We present a method for generating configurations using reachable volumes that is applicable to various types of robots including open and closed chain robots, tree-like robots, and complex robots including both loops and branches. We also describe how to apply constraints (both on end effectors and internal joints) using reachable volumes. Unlike previous methods, reachable volumes work for spherical and prismatic joints as well as planar joints. Visualizations of reachable volumes can allow an operator to see what positions the robot can reach and can guide robot design. We present visualizations of reachable volumes for representative robots including closed chains and graspers as well as for examples with joint and end effector constraints.

  19. Flux calculations in an inhomogeneous Universe: weighting a flux-limited galaxy sample

    CERN Document Server

    Koers, Hylke B J

    2009-01-01

    Many astrophysical problems arising within the context of ultra-high energy cosmic rays, very-high energy gamma rays or neutrinos, require calculation of the flux produced by sources tracing the distribution of galaxies in the Universe. We discuss a simple weighting scheme, an application of the method introduced by Lynden-Bell in 1971, that allows the calculation of the flux sky map directly from a flux-limited galaxy catalog without cutting a volume-limited subsample. Using this scheme, the galaxy distribution can be modeled up to large scales while representing the distribution in the nearby Universe with maximum accuracy. We consider fluctuations in the flux map arising from the finiteness of the galaxy sample. We show how these fluctuations are reduced by the weighting scheme and discuss how the remaining fluctuations limit the applicability of the method.

  20. Shannon Meets Nyquist: Capacity Limits of Sampled Analog Channels

    CERN Document Server

    Chen, Yuxin; Goldsmith, Andrea J

    2011-01-01

    We explore two fundamental questions at the intersection of sampling theory and information theory: how is channel capacity affected by sampling below the channel's Nyquist rate, and what sub-Nyquist sampling strategy should be employed to maximize capacity. In particular, we first derive the capacity of sampled analog channels for two prevalent sampling mechanisms: filtering followed by sampling and sampling following filter banks. Connections between sampling and MIMO Gaussian channels are illuminated based on this analysis. Optimal prefilters that maximize capacity are identified for both cases, as well as several kinds of channels for which these sampling mechanisms are optimal to maximize capacity at sub-Nyquist rates. We also highlight connections between sampled analog channel capacity and minimum mean squared error estimation from sampled data. In particular, it is shown that for both filtering and filter-bank sampling strategies, the filters maximizing capacity and minimizing mean squared error are e...

  1. EVALUATION OF VAPOR EQUILIBRATION AND IMPACT OF PURGE VOLUME ON SOIL-GAS SAMPLING RESULTS

    Science.gov (United States)

    Sequential sampling was utilized at the Raymark Superfund site to evaluate attainment of vapor equilibration and the impact of purge volume on soil-gas sample results. A simple mass-balance equation indicates that removal of three to five internal volumes of a sample system shou...

  2. Saliva sampling in global clinical studies: the impact of low sampling volume on performance of DNA in downstream genotyping experiments

    Science.gov (United States)

    2013-01-01

    Background The collection of viable DNA samples is an essential element of any genetics research programme. Biological samples for DNA purification are now routinely collected in many studies with a variety of sampling methods available. Initial observation in this study suggested a reduced genotyping success rate of some saliva derived DNA samples when compared to blood derived DNA samples prompting further investigation. Methods Genotyping success rate was investigated to assess the suitability of using saliva samples in future safety and efficacy pharmacogenetics experiments. The Oragene® OG-300 DNA Self-Collection kit was used to collect and extract DNA from saliva from 1468 subjects enrolled in global clinical studies. Statistical analysis evaluated the impact of saliva sample volume of collection on the quality, yield, concentration and performance of saliva DNA in genotyping assays. Results Across 13 global clinical studies that utilized the Oragene® OG-300 DNA Self-Collection kit there was variability in the volume of saliva sample collection with ~31% of participants providing 0.5 mL of saliva, rather than the recommended 2 mL. While the majority of saliva DNA samples provided high quality genotype data, collection of 0.5 mL volumes of saliva contributed to DNA samples being significantly less likely to pass genotyping quality control standards. Assessment of DNA sample characteristics that may influence genotyping outcomes indicated that saliva sample volume, DNA purity and turbidity were independently associated with sample genotype pass rate, but that saliva collection volume had the greatest effect. Conclusion When employing saliva sampling to obtain DNA, it is important to encourage all study participants to provide sufficient sample to minimize potential loss of data in downstream genotyping experiments. PMID:23759220

  3. A Generalized Sampling Theory without Band-Limiting Constraints

    OpenAIRE

    Unser, M.; Zerubia, J.

    1998-01-01

    We consider the problem of the reconstruction of a continuous-time function f(x) ∈ H from the samples of the responses of m linear shift-invariant systems sampled at 1 ⁄ m the reconstruction rate. We extend Papoulis' generalized sampling theory in two important respects. First, our class of admissible input signals (typ. H = $ L _{ 2 } $ ) is considerably larger than the subspace of bandlimited functions. Second, we use a more general specification of the reconstruction subspace V(φ), so that...

  4. Federal Radiological Monitoring and Assessment Center Monitoring Manual Volume 2, Radiation Monitoring and Sampling

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Aerial Measurement Systems

    2012-07-31

    The FRMAC Monitoring and Sampling Manual, Volume 2 provides standard operating procedures (SOPs) for field radiation monitoring and sample collection activities that are performed by the Monitoring group during a FRMAC response to a radiological emergency.

  5. Critical length sampling: a method to estimate the volume of downed coarse woody debris

    Science.gov (United States)

    G& #246; ran St& #229; hl; Jeffrey H. Gove; Michael S. Williams; Mark J. Ducey

    2010-01-01

    In this paper, critical length sampling for estimating the volume of downed coarse woody debris is presented. Using this method, the volume of downed wood in a stand can be estimated by summing the critical lengths of down logs included in a sample obtained using a relascope or wedge prism; typically, the instrument should be tilted 90° from its usual...

  6. CLUSTER SAMPLING FOR DETERMINATION OF IMMUNIZATION COVERAGE: A LIMITATION

    Directory of Open Access Journals (Sweden)

    K. Nasseri

    1989-08-01

    Full Text Available Evidence provided from studies in Iran points to a possible bias in application of the standard EPI cluster sampling procedure, When carried out in populations with highly variant birth rates, tends to over-represent the low birth rate, i.e. higher socio-economic, strata, and if the entity under study shows significant socio-economic gradient, then the estimates arrived at by this method might be highly biased. Some alternatives have been mentioned.

  7. The relationship between limit of Dysphagia and average volume per swallow in patients with Parkinson's disease.

    Science.gov (United States)

    Belo, Luciana Rodrigues; Gomes, Nathália Angelina Costa; Coriolano, Maria das Graças Wanderley de Sales; de Souza, Elizabete Santos; Moura, Danielle Albuquerque Alves; Asano, Amdore Guescel; Lins, Otávio Gomes

    2014-08-01

    The goal of this study was to obtain the limit of dysphagia and the average volume per swallow in patients with mild to moderate Parkinson's disease (PD) but without swallowing complaints and in normal subjects, and to investigate the relationship between them. We hypothesize there is a direct relationship between these two measurements. The study included 10 patients with idiopathic PD and 10 age-matched normal controls. Surface electromyography was recorded over the suprahyoid muscle group. The limit of dysphagia was obtained by offering increasing volumes of water until piecemeal deglutition occurred. The average volume per swallow was calculated by dividing the time taken by the number of swallows used to drink 100 ml of water. The PD group showed a significantly lower dysphagia limit and lower average volume per swallow. There was a significantly moderate direct correlation and association between the two measurements. About half of the PD patients had an abnormally low dysphagia limit and average volume per swallow, although none had spontaneously related swallowing problems. Both measurements may be used as a quick objective screening test for the early identification of swallowing alterations that may lead to dysphagia in PD patients, but the determination of the average volume per swallow is much quicker and simpler.

  8. Sampling hazelnuts for aflatoxin: Effects of sample size and accetp/reject limit on reducing risk of misclassifying lots

    Science.gov (United States)

    About 100 countries have established regulatory limits for aflatoxin in food and feeds. Because these limits vary widely among regulating countries, the Codex Committee on Food Additives and Contaminants (CCFAC) began work in 2004 to harmonize aflatoxin limits and sampling plans for aflatoxin in alm...

  9. Sampling based motion planning with reachable volumes: Application to manipulators and closed chain systems

    KAUST Repository

    McMahon, Troy

    2014-09-01

    © 2014 IEEE. Reachable volumes are a geometric representation of the regions the joints of a robot can reach. They can be used to generate constraint satisfying samples for problems including complicated linkage robots (e.g. closed chains and graspers). They can also be used to assist robot operators and to help in robot design.We show that reachable volumes have an O(1) complexity in unconstrained problems as well as in many constrained problems. We also show that reachable volumes can be computed in linear time and that reachable volume samples can be generated in linear time in problems without constraints. We experimentally validate reachable volume sampling, both with and without constraints on end effectors and/or internal joints. We show that reachable volume samples are less likely to be invalid due to self-collisions, making reachable volume sampling significantly more efficient for higher dimensional problems. We also show that these samples are easier to connect than others, resulting in better connected roadmaps. We demonstrate that our method can be applied to 262-dof, multi-loop, and tree-like linkages including combinations of planar, prismatic and spherical joints. In contrast, existing methods either cannot be used for these problems or do not produce good quality solutions.

  10. Comparison of uncertainties related to standardization of urine samples with volume and creatinine concentration

    DEFF Research Database (Denmark)

    Garde, Anne Helene; Hansen, Ase Marie; Kristiansen, Jesper;

    2004-01-01

    When measuring biomarkers in urine, volume (and time) or concentration of creatinine are both accepted methods of standardization for diuresis. Both types of standardization contribute uncertainty to the final result. The aim of the present paper was to compare the uncertainty introduced when using...... that the uncertainty associated with creatinine standardization (19-35%) was higher than the uncertainty related to volume standardization (up to 10%, when not correcting for deviations from 24 h) for 24 h urine samples. However, volume standardization introduced an average bias of 4% due to missed volumes...... in population studies. When studying a single 24 h sample from one individual, there was a 15-20% risk that the sample was incomplete. In this case a bias of approximately 25% was introduced when using volume standardization, whereas the uncertainty related to creatinine standardization was independent...

  11. A technique for sampling low shrub vegetation, by crown volume classes

    Science.gov (United States)

    Jay R. Bentley; Donald W. Seegrist; David A. Blakeman

    1970-01-01

    The effects of herbicides or other cultural treatments of low shrubs can be sampled by a new technique using crown volume as the key variable. Low shrubs were grouped in 12 crown volume classes with index values based on height times surface area of crown. The number of plants, by species, in each class is counted on quadrats. Many quadrats are needed for highly...

  12. Liquid chromatography-mass spectrometric determination of rufinamide in low volume plasma samples.

    Science.gov (United States)

    Gáll, Zsolt; Vancea, Szende; Dogaru, Maria T; Szilágyi, Tibor

    2013-12-01

    Quantification of rufinamide in plasma was achieved using a selective and sensitive liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method. The chromatographic separation was achieved on a reversed phase column (Zorbax SB-C18 100mm×3mm, 3.5μm) under isocratic conditions. The mobile phase consisted of a mixture of water containing 0.1% formic acid and methanol (50:50, v/v). The mass spectrometric detection of the analyte was in multiple reaction monitoring mode (MRM) using an electrospray positive ionization (ESI positive). The monitored ions were 127m/z derived from 239m/z rufinamide and 108m/z derived from 251m/z the internal standard (lacosamide). Protein precipitation with methanol was applied for sample preparation using only 50μl aliquots. The concentration range was 40-2000ng/ml for rufinamide in plasma. The limit of detection was 1.25ng/ml and the lower limit of quantification was established at 5ng/ml rufinamide concentration. Selectivity and matrix effect was verified using individual human, rat and rabbit plasma samples. Short-term, post-preparative and freeze-thaw stability was also investigated. The proposed method provides accuracy, precision and high-throughput (short runtime 4.5min) for quantitative determination of rufinamide in plasma. This is the first reported liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for analysis of rufinamide from low volume plasma samples. The LC-MS/MS method was validated according to the current official guidelines and can be applied to accurately measure rufinamide level of large number of plasma samples from clinical studies or therapeutic drug monitoring.

  13. Steady-state probability density function in wave turbulence under large volume limit

    Institute of Scientific and Technical Information of China (English)

    Yeontaek Choia; Sang Gyu Job

    2011-01-01

    We investigate the possibility for two-mode probability density function (PDF) to have a non-zero flux steady state solution. We take the large volume limit so that the space of modes becomes continuous. It is shown that in this limit all the steady-state two- or higher-mode PDFs are the product of one-mode PDFs. The flux of this steady-state solution turns out to be zero for any finite mode PDF.

  14. Effect of sample volume size and sampling method on feline longitudinal myocardial velocity profiles from color tissue Doppler imaging.

    Science.gov (United States)

    Granström, Sara; Pipper, Christian Bressen; Møgelvang, Rasmus; Sogaard, Peter; Willesen, Jakob Lundgren; Koch, Jørgen

    2012-12-01

    The aims of this study were to compare the effect of sample volume (SV) size settings and sampling method on measurement variability and peak systolic (s'), and early (e') and late (a') diastolic longitudinal myocardial velocities using color tissue Doppler imaging (cTDI) in cats. Twenty cats with normal echocardiograms and 20 cats with hypertrophic cardiomyopathy. We quantified and compared empirical variance and average absolute values of s', e' and a' for three cardiac cycles using eight different SV settings (length 1,2,3 and 5 mm; width 1 and 2 mm) and three methods of sampling (end-diastolic sampling with manual tracking of the SV, end-systolic sampling without tracking, and random-frame sampling without tracking). No significant difference in empirical variance could be demonstrated between most of the tested SVs. However, the two settings with a length of 1 mm resulted in a significantly higher variance compared with all settings where the SV length exceeded 2 mm (p sampling method on the variability of measurements (p = 0.003) and manual tracking obtained the lowest variance. No difference in average values of s', e' or a' could be found between any of the SV settings or sampling methods. Within the tested range of SV settings, an SV length of 1 mm resulted in higher measurement variability compared with an SV length of 3 and 5 mm, and should therefore be avoided. Manual tracking of the sample volume is recommended. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Mathematical model of diffusion-limited gas bubble dynamics in unstirred tissue with finite volume.

    Science.gov (United States)

    Srinivasan, R Srini; Gerth, Wayne A; Powell, Michael R

    2002-02-01

    Models of gas bubble dynamics for studying decompression sickness have been developed by considering the bubble to be immersed in an extravascular tissue with diffusion-limited gas exchange between the bubble and the surrounding unstirred tissue. In previous versions of this two-region model, the tissue volume must be theoretically infinite, which renders the model inapplicable to analysis of bubble growth in a finite-sized tissue. We herein present a new two-region model that is applicable to problems involving finite tissue volumes. By introducing radial deviations to gas tension in the diffusion region surrounding the bubble, the concentration gradient can be zero at a finite distance from the bubble, thus limiting the tissue volume that participates in bubble-tissue gas exchange. It is shown that these deviations account for the effects of heterogeneous perfusion on gas bubble dynamics, and are required for the tissue volume to be finite. The bubble growth results from a difference between the bubble gas pressure and an average gas tension in the surrounding diffusion region that explicitly depends on gas uptake and release by the bubble. For any given decompression, the diffusion region volume must stay above a certain minimum in order to sustain bubble growth.

  16. Central limit theorem of nonparametric estimate of spectral density functions of sample covariance matrices

    CERN Document Server

    Pan, Guangming; Zhou, Wang

    2010-01-01

    A consistent kernel estimator of the limiting spectral distribution of general sample covariance matrices was introduced in Jing, Pan, Shao and Zhou (2010). The central limit theorem of the kernel estimator is proved in this paper.

  17. Development of a novel high volume band compression injector for the analysis of complex samples like toxaphene pesticide.

    Science.gov (United States)

    Gagné, Jean-Pierre; Gouteux, Bruno; Bertrand, Michel J

    2009-01-16

    A new type of injector has been developed for gas chromatographic analysis. The injector has high volume and band compression (HVBC) capabilities useful for the analysis of complex samples. The injector consists essentially of a packed liner operated at room temperature while a narrow heated zone is used to axially scan the liner selectively desorbing the compounds of interest. The scanning speed, distance and temperature of the zone are precisely controlled. The liner is connected to an interface which can vent the solvent or any undesirable compounds, and transfer the analytes to an analytical column for separation and quantification. The injector is designed to be compatible with injection volumes from 1 to more than 250microL. At a low sample volume of 1microL, the injector has competitive performances compared to those of the "on-column" and "split/splitless" injectors for the fatty acid methyl esters and toxaphene compounds tested. For higher volumes, the system produces a linear response according to the injected volume. In this explorative study, the maximum volume injected seems to be limited by the saturation of the chromatographic system instead of being defined by the design of the injector. The HVBC injector can also be used to conduct "in situ" pretreatment of the sample before its transfer to the analytical column. For instance, a toxaphene sample was successively fractionated, using the HVBC injector, in six sub-fractions characterized by simpler chromatograms than the chromatogram of the original mixture. Finally, the ability of the HVBC injector to "freeze" the separation in time allowing the analyst to complete the analysis at a later time is also discussed.

  18. New Approach to Purging Monitoring Wells: Lower Flow Rates Reduce Required Purging Volumes and Sample Turbidity

    Science.gov (United States)

    It is generally accepted that monitoring wells must be purged to access formation water to obtain “representative” ground water quality samples. Historically anywhere from 3 to 5 well casing volumes have been removed prior to sample collection to evacuate the standing well water...

  19. Stability and Limit Oscillations of a Control Event-Based Sampling Criterion

    Directory of Open Access Journals (Sweden)

    M. De la Sen

    2012-01-01

    Full Text Available This paper investigates the presence of limit oscillations in an adaptive sampling system. The basic sampling criterion operates in the sense that each next sampling occurs when the absolute difference of the signal amplitude with respect to its currently sampled signal equalizes a prescribed threshold amplitude. The sampling criterion is extended involving a prescribed set of amplitudes. The limit oscillations might be interpreted through the equivalence of the adaptive sampling and hold device with a nonlinear one consisting of a relay with multiple hysteresis whose parameterization is, in general, dependent on the initial conditions of the dynamic system. The performed study is performed on the time domain.

  20. An immunomagnetic separator for concentration of pathogenic micro-organisms from large volume samples

    Energy Technology Data Exchange (ETDEWEB)

    Rotariu, Ovidiu [School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen (United Kingdom) and National Institute of R-D for Technical Physics I.F.T. Iasi, Mangeron 47 Blvd., Iasi (Romania)]. E-mail: o.rotariu@abdn.ac.uk; Ogden, Iain D. [Department of Medical Microbiology, University of Aberdeen, Aberdeen (United Kingdom); MacRae, Marion [Department of Medical Microbiology, University of Aberdeen, Aberdeen (United Kingdom); Badescu, Vasile [National Institute of R-D for Technical Physics I.F.T. Iasi, Mangeron 47 Blvd., Iasi (Romania); Strachan, Norval J.C. [School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen (United Kingdom)

    2005-05-15

    The standard method of immunomagnetic separation of pathogenic bacteria from food and environmental matrices processes 1 ml volumes. Pathogens present at low levels (<1 pathogenic bacteria per ml) will not be consistently detected by this method. Here a flow through immunomagnetic separator (FTIMS) has been designed and tested to process large volume samples (>50 ml). Preliminary results show that between 70 and 113 times more Escherchia coli O157 are recovered compared with the standard 1 ml method.

  1. Socioeconomic status and the cerebellar grey matter volume. Data from a well-characterised population sample.

    Science.gov (United States)

    Cavanagh, Jonathan; Krishnadas, Rajeev; Batty, G David; Burns, Harry; Deans, Kevin A; Ford, Ian; McConnachie, Alex; McGinty, Agnes; McLean, Jennifer S; Millar, Keith; Sattar, Naveed; Shiels, Paul G; Tannahill, Carol; Velupillai, Yoga N; Packard, Chris J; McLean, John

    2013-12-01

    The cerebellum is highly sensitive to adverse environmental factors throughout the life span. Socioeconomic deprivation has been associated with greater inflammatory and cardiometabolic risk, and poor neurocognitive function. Given the increasing awareness of the association between early-life adversities on cerebellar structure, we aimed to explore the relationship between early life (ESES) and current socioeconomic status (CSES) and cerebellar volume. T1-weighted MRI was used to create models of cerebellar grey matter volumes in 42 adult neurologically healthy males selected from the Psychological, Social and Biological Determinants of Ill Health study. The relationship between potential risk factors, including ESES, CSES and cerebellar grey matter volumes were examined using multiple regression techniques. We also examined if greater multisystem physiological risk index-derived from inflammatory and cardiometabolic risk markers-mediated the relationship between socioeconomic status (SES) and cerebellar grey matter volume. Both ESES and CSES explained the greatest variance in cerebellar grey matter volume, with age and alcohol use as a covariate in the model. Low CSES explained additional significant variance to low ESES on grey matter decrease. The multisystem physiological risk index mediated the relationship between both early life and current SES and grey matter volume in cerebellum. In a randomly selected sample of neurologically healthy males, poorer socioeconomic status was associated with a smaller cerebellar volume. Early and current socioeconomic status and the multisystem physiological risk index also apparently influence cerebellar volume. These findings provide data on the relationship between socioeconomic deprivation and a brain region highly sensitive to environmental factors.

  2. SAMPLING INTENSITY WITH FIXED PRECISION WHEN ESTIMATING VOLUME OF HUMAN BRAIN COMPARTMENTS

    Directory of Open Access Journals (Sweden)

    Rhiannon Maudsley

    2011-05-01

    Full Text Available Cavalieri sampling and point counting are frequently applied in combination with magnetic resonance (MR imaging to estimate the volume of human brain compartments. Current practice involves arbitrarily choosing the number of sections and sampling intensity within each section, and subsequently applying error prediction formulae to estimate the precision. The aim of this study is to derive a reference table for researchers who are interested in estimating the volume of brain regions, namely grey matter, white matter, and their union, to a given precision. In particular, this table, which is based on subsampling of a large brain data set obtained from coronal MR images, offers a recommendation for the minimum number of sections and mean number of points per section that are required to achieve a pre-defined coefficient of error of the volume estimator. Further analysis onMR brain data from a second human brain shows that the sampling intensity recommended is appropriate.

  3. The extended ROSAT-ESO Flux Limited X-ray Galaxy Cluster Survey (REFLEX II) III. Construction of the first flux-limited supercluster sample

    CERN Document Server

    Chon, Gayoung; Nowak, Nina

    2012-01-01

    We present the first supercluster catalogue constructed with the extended ROSAT-ESO Flux Limited X-ray Galaxy Cluster survey (REFLEX II) data, which comprises 919 X-ray selected galaxy clusters. Based on this cluster catalogue we construct a supercluster catalogue using a friends-of-friends algorithm with a linking length depending on the local cluster density. The resulting catalogue comprises 164 superclusters at redshift z<=0.4. We study the properties of different catalogues such as the distributions of the redshift, extent and multiplicity by varying the choice of parameters. In addition to the main catalogue we compile a large volume-limited cluster sample to investigate the statistics of the superclusters. We also compare the X-ray luminosity function for the clusters in superclusters with that for the field clusters with the flux- and volume-limited catalogues. The results mildly support the theoretical suggestion of a top-heavy X-ray luminosity function of galaxy clusters in regions of high cluste...

  4. Comparison of uncertainties related to standardization of urine samples with volume and creatinine concentration

    DEFF Research Database (Denmark)

    Garde, Anne Helene; Hansen, Ase Marie; Kristiansen, Jesper

    2004-01-01

    When measuring biomarkers in urine, volume (and time) or concentration of creatinine are both accepted methods of standardization for diuresis. Both types of standardization contribute uncertainty to the final result. The aim of the present paper was to compare the uncertainty introduced when using...... the two types of standardization on 24 h samples from healthy individuals. Estimates of uncertainties were based on results from the literature supplemented with data from our own studies. Only the difference in uncertainty related to the two standardization methods was evaluated. It was found...... increase in convenience for the participants, when collecting small volumes rather than complete 24 h samples....

  5. Overcoming ICP-QMS instrumental limitations for (99)Tc determination in environmental solid samples using radiochemistry.

    Science.gov (United States)

    Mas, José Luis; García-León, M; Bolívar, J P

    2006-04-01

    Besides its capabilities, quadrupole-based ICP-MS counting establishes several limitations on (99)Tc analysis in environmental samples. Overcoming these limitations requires the use of radiochemical methods. We have developed a new method for the detection of (99)Tc by ICP-QMS in solid environmental samples. In order to improve the limit of detection of the technique, high amounts of solid samples (> or = 100g) are used. Hence, great amounts of the interfering elements are involved in the process, and therefore special emphasis is put on achieving a good commitment between adequate matrix elements removal and a minimization of the limit of detection. The performances of the method are analyzed in terms of conveniently defined figures of merit. The developed method is applied to several fallout level samples. In this way, the real performances and especially the real limitations of this method are shown.

  6. Usefulness and limitation of punched-out orchidometer in testicular volume measurement

    Institute of Scientific and Technical Information of China (English)

    Koji Shiraishi; Hiroshi Takihara; Yoriaki Kamiryo; Katsusuke Naito

    2005-01-01

    Aim: To determine the limitations of a punched-out orchidometer in practical use, we compared with a scrotal ultrasound (USG). Methods: A total of 281 testes from 142 males were examined using both a punched-out orchidometer and a USG. The volume differential between both methods was calculated and expressed as orchidometer/USG volume (O/U ratio). Distribution of the O/U ratio was determined and subdivided by clinical or pathological diagnosis. The correlations between the O/U ratio and patient age or orchidometer results were assessed. Results:There was a significant linear relationship between the results of orchidometer and USG (r = 0.94, P < 0.0001). The relationship between the O/U ratio and age or testicular volumes showed significant inverse correlations (r = 0.22,P = 0.0002, r = 0.45, P<0.0001, respectively). Klinefelter's syndrome, ipsilateral detorted testes and hypogonadotropic hypogonadism comparatively showed a high O/U ratio. No incidental lesion was detected by USG necessitating treatment. Conclusion: The punched-out orchidometer gives estimates that correlated well with the USG measurements and provides enough information for routine andrological evaluation. We should be aware that the orchidometer often overestimates the testicular volume, especially for the patients with small testis or adolescents.

  7. Expiratory flow limitation and operating lung volumes during exercise in older and younger adults.

    Science.gov (United States)

    Smith, Joshua R; Kurti, Stephanie P; Meskimen, Kayla; Harms, Craig A

    2017-02-20

    We determined the effect of aging on expiratory flow limitation (EFL) and operating lung volumes when matched for lung size. We hypothesized that older adults will exhibit greater EFL and increases in EELV during exercise compared to younger controls. Ten older (5M/5W; >60years old) and nineteen height-matched young adults (10M/9W) were recruited. Young adults were matched for%predicted forced vital capacity (FVC) (Y-matched%Pred FVC; n=10) and absolute FVC (Y-matched FVC; n=10). Tidal flow-volume loops were recorded during the incremental exercise test with maximal flow-volume loops measured pre- and post-exercise. Compared to younger controls, older adults exhibited more EFL at ventilations of 26, 35, 51, and 80L/min. The older group had higher end-inspiratory lung volume compared to Y-matched%Pred FVC group during submaximal ventilations. The older group increased EELV during exercise, while EELV stayed below resting in the Y-matched%Pred FVC group. These data suggest older adults exhibit more EFL and increase EELV earlier during exercise compared to younger adults.

  8. Bloch Waves in Minimal Landau Gauge and the Infinite-Volume Limit of Lattice Gauge Theory

    Science.gov (United States)

    Cucchieri, Attilio; Mendes, Tereza

    2017-05-01

    By exploiting the similarity between Bloch's theorem for electrons in crystalline solids and the problem of Landau gauge fixing in Yang-Mills theory on a "replicated" lattice, we show that large-volume results can be reproduced by simulations performed on much smaller lattices. This approach, proposed by Zwanziger [Nucl. Phys. B412, 657 (1994), 10.1016/0550-3213(94)90396-4], corresponds to taking the infinite-volume limit for Landau-gauge field configurations in two steps: first for the gauge transformation alone, while keeping the lattice volume finite, and second for the gauge-field configuration itself. The solutions to the gauge-fixing condition are then given in terms of Bloch waves. Applying the method to data from Monte Carlo simulations of pure SU(2) gauge theory in two and three space-time dimensions, we are able to evaluate the Landau-gauge gluon propagator for lattices of linear extent up to 16 times larger than that of the simulated lattice. This approach is reminiscent of the Fisher-Ruelle construction of the thermodynamic limit in classical statistical mechanics.

  9. Multi-channel sampling theorems for band-limited signals with fractional Fourier transform

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Multi-channel sampling for band-limited signals is fundamental in the theory of multi-channel parallel A/D environment and multiplexing wireless communication environment. As the fractional Fourier transform has been found wide applications in signal processing fields, it is necessary to consider the multi-channel sampling theorem based on the fractional Fourier transform. In this paper, the multi-channel sampling theorem for the fractional band-limited signal is firstly proposed, which is the generalization of the well-known sampling theorem for the fractional Fourier transform. Since the periodic nonuniformly sampled signal in the fractional Fourier domain has valuable applications, the reconstruction expression for the periodic nonuniformly sampled signal has been then obtained by using the derived multi-channel sampling theorem and the specific space-shifting and phase-shifting properties of the fractional Fourier transform. Moreover, by designing different fractional Fourier filters, we can obtain reconstruction methods for other sampling strategies.

  10. The electrical breakdown strength of pre-stretched elastomers, with and without sample volume conservation

    DEFF Research Database (Denmark)

    Zakaria, Shamsul Bin; Morshuis, Peter H. F.; Yahia, Benslimane Mohamed;

    2015-01-01

    strength of polydimethylsiloxane (PDMS) elastomers. Breakdown strength was determined for samples with and without volume conservation and was found to depend strongly on the stretch ratio and the thickness of thesamples. PDMS elastomers are shown to increase breakdown strength by a factor of ∼3 when...

  11. Quantitative study on exact reconstruction sampling condition by verifying solution uniqueness in limited-view CT.

    Science.gov (United States)

    Yan, Bin; Zhang, Wenkun; Li, Lei; Zhang, Hanming; Wang, Linyuan

    2016-10-01

    In limited-view computed tomography reconstruction, iterative image reconstruction with sparsity-exploiting methods, such as total variation (TV) minimization, inspired by compressive sensing, potentially claims large reductions in sampling requirements. However, a quantitative notion of this claim is non-trivial because of the ill-defined reduction in sampling achieved by the sparsity-exploiting method. In this paper, exact reconstruction sampling condition for limited-view problem is studied by verifying the uniqueness of solution in TV minimization model. Uniqueness is tested by solving a convex optimization problem derived from the sufficient and necessary condition of solution uniqueness. Through this method, the sufficient sampling number of exact reconstruction is quantified for any fixed phantom and settled geometrical parameter in the limited-view problem. This paper provides a reference to quantify the sampling condition. Three phantoms are tested to study the sampling condition of limited view exact reconstruction in this paper. The experiment results show the quantified sampling number and indicate that an object would be accurately reconstructed as the scanning range becomes narrower by increasing sampling number. The increased samplings compensate for the deficiency of the projection angle. However, the lower bound of the scanning range corresponding to three different phantoms are presented, in which an exact reconstruction cannot be obtained once the projection angular is narrowed to this extent no matter how to increase sampling.

  12. Ultimate detectability of volatile organic compounds: how much further can we reduce their ambient air sample volumes for analysis?

    Science.gov (United States)

    Kim, Yong-Hyun; Kim, Ki-Hyun

    2012-10-02

    To understand the ultimately lowest detection range of volatile organic compounds (VOCs) in air, application of a high sensitivity analytical system was investigated by coupling thermal desorption (TD) technique with gas chromatography (GC) and time-of-flight (TOF) mass spectrometry (MS). The performance of the TD-GC/TOF MS system was evaluated using liquid standards of 19 target VOCs prepared in the range of 35 pg to 2.79 ng per μL. Studies were carried out using both total ion chromatogram (TIC) and extracted ion chromatogram (EIC) mode. EIC mode was used for calibration to reduce background and to improve signal-to-noise. The detectability of 19 target VOCs, if assessed in terms of method detection limit (MDL, per US EPA definition) and limit of detection (LOD), averaged 5.90 pg and 0.122 pg, respectively, with the mean coefficient of correlation (R(2)) of 0.9975. The minimum quantifiable mass of target analytes, when determined using real air samples by the TD-GC/TOF MS, is highly comparable to the detection limits determined experimentally by standard. In fact, volumes for the actual detection of the major aromatic VOCs like benzene, toluene, and xylene (BTX) in ambient air samples were as low as 1.0 mL in the 0.11-2.25 ppb range. It was thus possible to demonstrate that most target compounds including those in low abundance could be reliably quantified at concentrations down to 0.1 ppb at sample volumes of less than 10 mL. The unique sensitivity of this advanced analytical system can ultimately lead to a shift in field sampling strategy with smaller air sample volumes facilitating faster, simpler air sampling (e.g., use of gas syringes rather than the relative complexity of pumps or bags/canisters), with greatly reduced risk of analyte breakthrough and minimal interference, e.g., from atmospheric humidity. The improved detection limits offered by this system can also enhance accuracy and measurement precision.

  13. Determination of air-loop volume and radon partition coefficient for measuring radon in water sample.

    Science.gov (United States)

    Lee, Kil Yong; Burnett, William C

    A simple method for the direct determination of the air-loop volume in a RAD7 system as well as the radon partition coefficient was developed allowing for an accurate measurement of the radon activity in any type of water. The air-loop volume may be measured directly using an external radon source and an empty bottle with a precisely measured volume. The partition coefficient and activity of radon in the water sample may then be determined via the RAD7 using the determined air-loop volume. Activity ratios instead of absolute activities were used to measure the air-loop volume and the radon partition coefficient. In order to verify this approach, we measured the radon partition coefficient in deionized water in the temperature range of 10-30 °C and compared the values to those calculated from the well-known Weigel equation. The results were within 5 % variance throughout the temperature range. We also applied the approach for measurement of the radon partition coefficient in synthetic saline water (0-75 ppt salinity) as well as tap water. The radon activity of the tap water sample was determined by this method as well as the standard RAD-H2O and BigBottle RAD-H2O. The results have shown good agreement between this method and the standard methods.

  14. Algorithm-Eigenvalue Estimation of Hyperspectral Wishart Covariance Matrices from a Limited Number of Samples

    Science.gov (United States)

    2015-03-01

    ALGORITHM—EIGENVALUE ESTIMATION OF HYPERSPECTRAL WISHART COVARIANCE MATRICES FROM A LIMITED NUMBER OF SAMPLES ECBC-TN-067 Avishai Ben-David...Estimation of Hyperspectral Wishart Covariance Matrices from a Limited Number of Samples 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...covariance matrices and to recompute a revised covariance matrix from the eigenvalues. The MATLAB function is an implementation of the procedure developed

  15. Quantitative Study on Exact Reconstruction Sampling Condition in Limited-view CT

    CERN Document Server

    Yan, Bin; Li, Lei; Zhang, Hanming; Wang, Linyuan

    2016-01-01

    In limited-view computed tomography reconstruction, iterative image reconstruction with sparsity-exploiting methods, such as total variation (TV) minimization, inspired by compressive sensing, potentially claims large reductions in sampling requirements. However, a quantitative notion of this claim is non-trivial because of the ill-defined reduction in sampling achieved by the sparsity-exploiting method. In this paper, exact reconstruction sampling condition for limited-view problem is studied by verifying the uniqueness of solution in TV minimization model. Uniqueness is tested by solving a convex optimization problem derived from the sufficient and necessary condition of solution uniqueness. Through this method, the sufficient sampling number of exact reconstruction is quantified for any fixed phantom and settled geometrical parameter in the limited-view problem. This paper provides a reference to quantify the sampling condition. Using Shepp-Logan phantom as an example, the experiment results show the quant...

  16. Accurately measuring volume of soil samples using low cost Kinect 3D scanner

    Science.gov (United States)

    van der Sterre, Boy-Santhos; Hut, Rolf; van de Giesen, Nick

    2013-04-01

    The 3D scanner of the Kinect game controller can be used to increase the accuracy and efficiency of determining in situ soil moisture content. Soil moisture is one of the principal hydrological variables in both the water and energy interactions between soil and atmosphere. Current in situ measurements of soil moisture either rely on indirect measurements (of electromagnetic constants or heat capacity) or on physically taking a sample and weighing it in a lab. The bottleneck in accurately retrieving soil moisture using samples is the determining of the volume of the sample. Currently this is mostly done by the very time consuming "sand cone method" in which the volume were the sample used to sit is filled with sand. We show that 3D scanner that is part of the 150 game controller extension "Kinect" can be used to make 3D scans before and after taking the sample. The accuracy of this method is tested by scanning forms of known volume. This method is less time consuming and less error-prone than using a sand cone.

  17. Confidence limits for the mean of exponential distribution in any time-sequential samples

    Institute of Scientific and Technical Information of China (English)

    CHEN Jiading; FANG Xiangzhong

    2005-01-01

    We present the general results determining confidence limits for the mean of exponential distribution in any time-sequential samples, which are obtained in any sequential life tests with replacement or without replacement. Especially, we give the best lower confidence limits in the case of no failure data.

  18. Gamut Volume Index: a color preference metric based on meta-analysis and optimized colour samples.

    Science.gov (United States)

    Liu, Qiang; Huang, Zheng; Xiao, Kaida; Pointer, Michael R; Westland, Stephen; Luo, M Ronnier

    2017-07-10

    A novel metric named Gamut Volume Index (GVI) is proposed for evaluating the colour preference of lighting. This metric is based on the absolute gamut volume of optimized colour samples. The optimal colour set of the proposed metric was obtained by optimizing the weighted average correlation between the metric predictions and the subjective ratings for 8 psychophysical studies. The performance of 20 typical colour metrics was also investigated, which included colour difference based metrics, gamut based metrics, memory based metrics as well as combined metrics. It was found that the proposed GVI outperformed the existing counterparts, especially for the conditions where correlated colour temperatures differed.

  19. Upper limits for chlorophylla changes with brine volume in sea ice during the austral spring in the Weddell Sea, Antarctica

    Institute of Scientific and Technical Information of China (English)

    LI Zhijun; LI Runling; WANG Zipan; HAAS Christian; DIECKMANN Gerhard

    2016-01-01

    During the winter and spring of 2006, we investigated the sea ice physics and marine biology in the northwest Weddell Sea, Antarctica aboard R/VPolarstern. We determined the texture of each ice core and 71 ice crystal thin sections from 27 ice cores. We analyzed 393 ice cores, their temperatures, 348 block density and salinity samples, and 311 chlorophylla (Chla) and phaeophytin samples along the cruise route during the investigation. Based on the vertical distributions of 302 groups of data for the ice porosity and Chla content in the ice at the same position, we obtained new evidence that ice physical parameters influence the Chla content in ice. We collected snow and ice thickness data, and established the effects of the snow and ice thickness on the Chla blooms under the ice, as well as the relationships between the activity of ice algae cells and the brine volume in ice according to the principle of environmental control of the ecological balance. We determined the upper limits for Chla in the brine volume of granular and columnar ice in the Antarctica, thereby demonstrating the effects of ice crystals on brine drainage, and the contributions of the physical properties of sea ice to Chla blooms near the ice bottom and on the ice-water interface in the austral spring. Moreover, we found that the physical properties of sea ice affect ice algae and they are key control elements that modulate marine phytoplankton blooms in the ice-covered waters around Antarctica.

  20. The beryllium quandary: will the lower exposure limits spur new developments in sampling and analysis?

    Energy Technology Data Exchange (ETDEWEB)

    Brisson, Michael

    2013-06-03

    At the time this article was written, new rulemakings were under consideration at OSHA and the U.S. Department of Energy (DOE) that would propose changes to occupational exposure limits for beryllium. Given these developments, it’s a good time to review the tools and methods available to IHs for assessing beryllium air and surface contamination in the workplace—what’s new and different, and what’s tried and true. The article discusses limit values and action levels for beryllium, problematic aspects of beryllium air sampling, sample preparation, sample analysis, and data evaluation.

  1. RESOLVE Survey Photometry and Volume-limited Calibration of the Photometric Gas Fractions Technique

    CERN Document Server

    Eckert, Kathleen D; Stark, David V; Moffett, Amanda J; Norris, Mark A; Snyder, Elaine M; Hoversten, Erik A

    2015-01-01

    We present custom-processed UV, optical, and near-IR photometry for the RESOLVE survey, a volume-limited census of stellar, gas, and dynamical mass within two subvolumes of the nearby universe (RESOLVE-A and -B), complete down to baryonic mass ~10^9.1-9.3 Msun. In contrast to standard pipeline photometry (e.g., SDSS), our photometry uses optimal background subtraction, avoids suppressing color gradients, and includes systematic errors. With these improvements, we measure brighter magnitudes, larger radii, bluer colors, and a real increase in scatter around the red sequence. Combining stellar masses from our photometry with the RESOLVE-A HI mass census, we create volume-limited calibrations of the photometric gas fractions (PGF) technique, which predicts gas-to-stellar mass ratios (G/S) from galaxy colors and optional additional parameters. We analyze G/S-color residuals vs. potential third parameters, finding that axial ratio is the best independent and physically meaningful third parameter. We define a "modi...

  2. Limitations of stroke volume estimation by non-invasive blood pressure monitoring in hypergravity.

    Directory of Open Access Journals (Sweden)

    Olivier Manen

    Full Text Available Altitude and gravity changes during aeromedical evacuations induce exacerbated cardiovascular responses in unstable patients. Non-invasive cardiac output monitoring is difficult to perform in this environment with limited access to the patient. We evaluated the feasibility and accuracy of stroke volume estimation by finger photoplethysmography (SVp in hypergravity.Finger arterial blood pressure (ABP waveforms were recorded continuously in ten healthy subjects before, during and after exposure to +Gz accelerations in a human centrifuge. The protocol consisted of a 2-min and 8-min exposure up to +4 Gz. SVp was computed from ABP using Liljestrand, systolic area, and Windkessel algorithms, and compared with reference values measured by echocardiography (SVe before and after the centrifuge runs.The ABP signal could be used in 83.3% of cases. After calibration with echocardiography, SVp changes did not differ from SVe and values were linearly correlated (p<0.001. The three algorithms gave comparable SVp. Reproducibility between SVp and SVe was the best with the systolic area algorithm (limits of agreement -20.5 and +38.3 ml.Non-invasive ABP photoplethysmographic monitoring is an interesting technique to estimate relative stroke volume changes in moderate and sustained hypergravity. This method may aid physicians for aeronautic patient monitoring.

  3. Optical limiting using spatial self-phase modulation in hot atomic sample

    Science.gov (United States)

    Zhang, Qian; Cheng, Xuemei; Zhang, Ying; Yin, Xunli; Jiang, Man; Chen, Haowei; Bai, Jintao

    2017-02-01

    In this work, we characterized the performance of optical limiting by self-phase modulation (SPM) in hot atomic vapor cell. The results indicated that the performance of the optical limiter is closely related to the position of the sample cell, which is determined by the Rayleigh lenght of beam. The lowest limiting threshold and clamp output were obtained at the sample position at -10 mm from the coordinate origin (the beam waist). The phenomenon was explained well by the theory of SPM and z-scan, which are caused by both Kerr effect and the thermal optical nonlinear effect. This useful information obtained in the meaning of this work is determining the optimal position of the sample cell in the optical limiter and other applications of SPM.

  4. ON LIMITATIONS OF THE SAMPLED-DATA FEEDBACK FOR NONPARAMETRIC DYNAMICAL SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    XUE Feng; GUO Lei

    2002-01-01

    In this paper, we study a basic class of first order sampled-data control systems with unknown nonlinear structure and with sampling rate not necessarily fast enough,aiming at understanding the capability and limitations of the sampled-data feedback. We show that if the unknown nonlinear function has a linear growth rate with its "slope"(denoted by L) being a measure of the "size" of uncertainty, then the sampling rate should not exceed 1/L multiplied by a constant (≈ 7.53) for the system to be globally stabilizable by the sampled-data feedback. If, however, the unknown nonlinear function has a growth rate faster than linear, and if the system is disturbed by noises modeled as the standard Brownian motion, then an example is given, showing that the corresponding sampled-data system is not stabilizable by the sampled-data feedback in general, no matter how fast the sampling rate is.

  5. Reliable measurements for an image-derived sample volume in an open-configuration MR system

    Science.gov (United States)

    Han, Bong Soo; Lee, Man Woo; Hong, Cheolpyo

    2016-11-01

    Open-configuration magnetic resonance (MR) systems are becoming desirable for volume measurements of off-center samples due to their non-claustrophobic system configuration, excellent soft-tissue contrast, high efficiency, and low-cost. However, geometric distortion is produced by the unwanted background magnetic field and hinders volume measurements. The present study describes the characteristics of geometric distortion in off-center samples such as the thigh muscle and adipose tissue measurements using an open-type MR system. The American Association of Physicists in Medicine uniformity and linearity phantom was used for the detection and the evaluation of the geometric distortion. The geometric distortion decreased near the isocenter and increased toward the off-center. A cylindrical phantom image was acquired at the isocenter and was used as the distortion-free, reference image. Two cylindrical phantoms were scanned off-center at a position analogous to that of the human thigh. The differences between the two cylindrical phantom volumes and the reference volume were 1.62 % ± 0.16 and 5.18 % ± 0.14. Off-center-related MR imaging requires careful consideration for image interpretation and volumetric assessment of tissue.

  6. Impact of sampling time deviations on the prediction of the area under the curve using regression limited sampling strategies.

    Science.gov (United States)

    Sarem, Sarem; Nekka, Fahima; Ahmed, Iman Saad; Litalien, Catherine; Li, Jun

    2015-10-01

    The regression limited sampling strategy approach (R-LSS), which is based on a small number of blood samples drawn at selected time points, has been used as an alternative method for the estimation of the area under the concentration-time curve (AUC). However, deviations from planned sampling times may affect the performance of R-LSS, influencing related therapeutic decisions and outcomes. The aim of this study was to investigate the impact of different sampling time deviation (STD) scenarios on the estimation of AUC by the R-LSS using a simulation approach. Three types of scenarios were considered going from the simplest case of fixed deviations, to random deviations and then to a more realistic case where deviations of mixed nature can occur. In addition, the sensitivity of the R-LSS to STD in each involved sampling point was evaluated. A significant impact of STD on the performance of R-LSS was demonstrated. The tolerance of R-LSS to STD was found to depend not only on the number of sampling points but more importantly on the duration of the sampling process. Sensitivity analysis showed that sampling points at which rapid concentration changes occur were relatively more critical for AUC prediction by R-LSS. As a practical approach, nomograms were proposed, where the expected predictive performance of R-LSS was provided as a function of STD information. The investigation of STD impact on the predictive performance of R-LSS is a critical element and should be routinely performed to guide R-LSS selection and use.

  7. Rotation-translation device for condensed-phase spectroscopy with small sample volumes

    Science.gov (United States)

    Nuernberger, Patrick; Krampert, Gerhard; Brixner, Tobias; Vogt, Gerhard

    2006-08-01

    We present and characterize an experimental device for optical spectroscopy with small sample volumes contained in a thin film. Employing rotational and translational motion, the sample transport speeds are high enough to offer a new sample volume for each interaction in time-resolved spectroscopy experiments working with a 1kHz repetition rate. This is especially suited for ultrafast femtosecond spectroscopy such as transient absorption spectroscopy or fluorescence upconversion. To reduce photodegradation and effects from local thermal heating, a large sample area is scanned in contrast to conventional devices with either only rotation or translation movements. For characterization of the setup, transient absorption experiments are carried out using the rotation-translation device and a conventional flow-cell setup, which exhibit similar signal-to-noise ratio in the two cases. The effects of photodegradation and diffusion are also investigated, demonstrating the suitability of the device for time-resolved spectroscopic experiments. The transient absorption data show that the setup is well suited for biomolecular samples, which are often only available in small amounts and are very sensitive to thermal heating.

  8. Influence of Sample Volume and Solvent Evaporation on Absorbance Spectroscopy in a Microfluidic "Pillar-Cuvette".

    Science.gov (United States)

    Kriel, Frederik H; Priest, Craig

    2016-01-01

    Spectroscopic analysis of solutions containing samples at high concentrations or molar absorptivity can present practical challenges. In absorbance spectroscopy, short optical path lengths or multiple dilution is required to bring the measured absorbance into the range of the Beer's Law calibration. We have previously reported an open "pillar-cuvette" with a micropillar array that is spontaneously filled with a precise (nL or μL) volume to create the well-defined optical path of, for example, 10 to 20 μm. Evaporation should not be ignored for open cuvettes and, herein, the volume of loaded sample and the rate of evaporation from the cuvette are studied. It was found that the volume of loaded sample (between 1 and 10 μL) had no effect on the Beer's Law calibration for methyl orange solutions (molar absorptivity of (2.42 ± 0.02)× 10(4) L mol(-1) cm(-1)) for cuvettes with a 14.2 ± 0.2 μm path length. Evaporation rates of water from methyl orange solutions were between 2 and 5 nL s(-1) (30 - 40% relative humidity; 23°C), depending on the sample concentration and ambient conditions. Evaporation could be reduced by placing a cover slip several millimeters above the cuvette. Importantly, the results show that a "drop-and-measure" method (measurement within ∼3 s of cuvette loading) eliminates the need for extrapolation of the absorbance-time data for accurate analysis of samples.

  9. Comparison of estimates of hardwood bole volume using importance sampling, the centroid method, and some taper equations

    Science.gov (United States)

    Harry V., Jr. Wiant; Michael L. Spangler; John E. Baumgras

    2002-01-01

    Various taper systems and the centroid method were compared to unbiased volume estimates made by importance sampling for 720 hardwood trees selected throughout the state of West Virginia. Only the centroid method consistently gave volumes estimates that did not differ significantly from those made by importance sampling, although some taper equations did well for most...

  10. Analytical Chemistry Laboratory (ACL) procedure compendium. Volume 2, Sample preparation methods

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    This volume contains the interim change notice for sample preparation methods. Covered are: acid digestion for metals analysis, fusion of Hanford tank waste solids, water leach of sludges/soils/other solids, extraction procedure toxicity (simulate leach in landfill), sample preparation for gamma spectroscopy, acid digestion for radiochemical analysis, leach preparation of solids for free cyanide analysis, aqueous leach of solids for anion analysis, microwave digestion of glasses and slurries for ICP/MS, toxicity characteristic leaching extraction for inorganics, leach/dissolution of activated metal for radiochemical analysis, extraction of single-shell tank (SST) samples for semi-VOC analysis, preparation and cleanup of hydrocarbon- containing samples for VOC and semi-VOC analysis, receiving of waste tank samples in onsite transfer cask, receipt and inspection of SST samples, receipt and extrusion of core samples at 325A shielded facility, cleaning and shipping of waste tank samplers, homogenization of solutions/slurries/sludges, and test sample preparation for bioassay quality control program.

  11. The LLNL High Accuracy Volume Renderer for Unstructured Data: Capabilities, Current Limits, and Potential for ASCI/VIEWS Deployment

    Energy Technology Data Exchange (ETDEWEB)

    Williams, P L; Max, N L

    2001-06-04

    This report describes a volume rendering system for unstructured data, especially finite element data, that creates images with very high accuracy. The system will currently handle meshes whose cells are either linear or quadratic tetrahedra, or meshes with mixed cell types: tetrahedra, bricks, prisms, and pyramids. The cells may have nonplanar facets. Whenever possible, exact mathematical solutions for the radiance integrals and for interpolation are used. Accurate semitransparent shaded isosurfaces may be embedded in the volume rendering. For very small cells, subpixel accumulation by splatting is used to avoid sampling error. A new exact and efficient visibility ordering algorithm is described. The most accurate images are generated in software, however, more efficient algorithms utilizing graphics hardware may also be selected. The report describes the parallelization of the system for a distributed-shared memory multiprocessor machine, and concludes by discussing the system's limits, desirable future work, and ways to extend the system so as to be compatible with projected ASCI/VIEWS architectures.

  12. A limited sampling strategy for the estimation of Neoral AUCs in pediatric patients.

    Science.gov (United States)

    Meier-Kriesche, H U; Bonilla-Felix, M A; Ferris, M E; Swinford, R; Kahan, B D; Brannan, P; Portman, R J

    1999-11-01

    The improved pharmacokinetics of Neoral allows the development of an accurate estimate of the full area under the concentration time curve (AUC) from a limited sampling strategy. As no such strategy has been derived from pharmacokinetic data obtained from children on 12-hourly dosing, and as patient convenience demands shorter sampling times, we derived a limited sampling strategy from 45 AUCs obtained from 19 pediatric renal transplant patients by stepwise forward multiple regression, and prospectively tested them on a separate group of 49 AUCs obtained from 18 pediatric renal transplant patients. Full cyclosporine (CsA) AUCs were obtained from samples drawn pre dose (C0) and at 2, 4, 6, 8 and 12 h post dose (C2, C4, C6, C8, and C12). High-precision predictions of full AUC were obtained based on the formula: AUC = 444 + 3.69 x C0 + 1.77 x C2 + 4. 1 x C4 (mean prediction error +/- SD = 0.3 +/- 6.4%, 95% confidence interval=-1.7% to 1.9%.) In conclusion, CsA exposure in pediatric renal transplant patients on 12-hourly Neoral dosing can be reliably predicted by an early time point-based limited sampling strategy in children. This formula has the advantage of obtaining trough as well as AUC from one brief, convenient sampling period.

  13. Reference Equations for Static Lung Volumes and TLCO from a Population Sample in Northern Greece.

    Science.gov (United States)

    Michailopoulos, Pavlos; Kontakiotis, Theodoros; Spyratos, Dionisios; Argyropoulou-Pataka, Paraskevi; Sichletidis, Lazaros

    2015-02-14

    Background: The most commonly used reference equations for the measurement of static lung volumes/capacities and transfer factor of the lung for CO (TLCO) are based on studies around 30-40 years old with significant limitations. Objectives: Our aim was to (1) develop reference equations for static lung volumes and TLCO using the current American Thoracic Society/European Respiratory Society guidelines, and (2) compare the equations derived with those most commonly used. Methods: Healthy Caucasian subjects (234 males and 233 females) aged 18-91 years were recruited. All of them were healthy never smokers with a normal chest X-ray. Static lung volumes and TLCO were measured with a single-breath technique according to the latest guidelines. Results: Curvilinear regression prediction equations derived from the present study were compared with those that are most commonly used. Our reference equations in accordance with the latest studies show lower values for all static lung volume parameters and TLCO as well as a different way of deviation of those parameters (i.e. declining with age total lung capacity, TLCO age decline in both sex and functional residual capacity age rise in males). Conclusions: We suggest that old reference values of static lung volumes and TLCO should be updated, and our perception of deviation of some spirometric parameters should be revised. Our new reference curvilinear equations derived according to the latest guidelines could contribute to the updating by respiratory societies of old existing reference values and result in a better estimation of the lung function of contemporary populations with similar Caucasian characteristics. © 2015 S. Karger AG, Basel.

  14. Utilities and offsites design baseline. Outside Battery Limits Facility 6000 tpd SRC-I Demonstration Plant. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    None

    1984-05-25

    As part of the overall Solvent Refined Coal (SRC-1) project baseline being prepared by International Coal Refining Company (ICRC), the RUST Engineering Company is providing necessary input for the Outside Battery Limits (OSBL) Facilities. The project baseline is comprised of: design baseline - technical definition of work; schedule baseline - detailed and management level 1 schedules; and cost baseline - estimates and cost/manpower plan. The design baseline (technical definition) for the OSBL Facilities has been completed and is presented in Volumes I, II, III, IV, V and VI. The OSBL technical definition is based on, and compatible with, the ICRC defined statement of work, design basis memorandum, master project procedures, process and mechanical design criteria, and baseline guidance documents. The design basis memorandum is included in Paragraph 1.3 of Volume I. The baseline design data is presented in 6 volumes. Volume I contains the introduction section and utility systems data through steam and feedwater. Volume II continues with utility systems data through fuel system, and contains the interconnecting systems and utility system integration information. Volume III contains the offsites data through water and waste treatment. Volume IV continues with offsites data, including site development and buildings, and contains raw materials and product handling and storage information. Volume V contains wastewater treatment and solid wastes landfill systems developed by Catalytic, Inc. to supplement the information contained in Volume III. Volume VI contains proprietary information of Resources Conservation Company related to the evaporator/crystallizer system of the wastewater treatment area.

  15. Transfer function design based on user selected samples for intuitive multivariate volume exploration

    KAUST Repository

    Zhou, Liang

    2013-02-01

    Multivariate volumetric datasets are important to both science and medicine. We propose a transfer function (TF) design approach based on user selected samples in the spatial domain to make multivariate volumetric data visualization more accessible for domain users. Specifically, the user starts the visualization by probing features of interest on slices and the data values are instantly queried by user selection. The queried sample values are then used to automatically and robustly generate high dimensional transfer functions (HDTFs) via kernel density estimation (KDE). Alternatively, 2D Gaussian TFs can be automatically generated in the dimensionality reduced space using these samples. With the extracted features rendered in the volume rendering view, the user can further refine these features using segmentation brushes. Interactivity is achieved in our system and different views are tightly linked. Use cases show that our system has been successfully applied for simulation and complicated seismic data sets. © 2013 IEEE.

  16. Enrichment of diluted cell populations from large sample volumes using 3D carbon-electrode dielectrophoresis.

    Science.gov (United States)

    Islam, Monsur; Natu, Rucha; Larraga-Martinez, Maria Fernanda; Martinez-Duarte, Rodrigo

    2016-05-01

    Here, we report on an enrichment protocol using carbon electrode dielectrophoresis to isolate and purify a targeted cell population from sample volumes up to 4 ml. We aim at trapping, washing, and recovering an enriched cell fraction that will facilitate downstream analysis. We used an increasingly diluted sample of yeast, 10(6)-10(2) cells/ml, to demonstrate the isolation and enrichment of few cells at increasing flow rates. A maximum average enrichment of 154.2 ± 23.7 times was achieved when the sample flow rate was 10 μl/min and yeast cells were suspended in low electrically conductive media that maximizes dielectrophoresis trapping. A COMSOL Multiphysics model allowed for the comparison between experimental and simulation results. Discussion is conducted on the discrepancies between such results and how the model can be further improved.

  17. Uncertainties Quantification and Propagation of Multiple Correlated Variables with Limited Samples

    Science.gov (United States)

    Zhanpeng, Shen; Xueqian, Chen; Xinen, Liu; Chaoping, Zang

    2016-09-01

    In order to estimate the reliability of an engineering structure based on limited test data, it is distinctly important to address both the epistemic uncertainty from lacking in samples and correlations between input uncertain variables. Both the probability boxes theory and copula function theory are utilized in proposed method to represent uncertainty and correlation of input variables respectively. Moreover, the uncertainty of response of interest is obtained by uncertainty propagation of correlated input variables. Nested sampling technique is adopted here to insure the propagation is always feasible and the response's uncertainty is characterized by a probability box. Finally, a numerical example illustrates the validity and effectiveness of our method. The results indicate that the epistemic uncertainty cannot be conveniently ignored when available samples are very limited and correlations among input variables may significantly affect the uncertainty of responses.

  18. Automated high-volume aerosol sampling station for environmental radiation monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Toivonen, H.; Honkamaa, T.; Ilander, T.; Leppaenen, A.; Nikkinen, M.; Poellaenen, R.; Ylaetalo, S

    1998-07-01

    An automated high-volume aerosol sampling station, known as CINDERELLA.STUK, for environmental radiation monitoring has been developed by the Radiation and Nuclear Safety Authority (STUK), Finland. The sample is collected on a glass fibre filter (attached into a cassette), the airflow through the filter is 800 m{sup 3}/h at maximum. During the sampling, the filter is continuously monitored with Na(I) scintillation detectors. After the sampling, the large filter is automatically cut into 15 pieces that form a small sample and after ageing, the pile of filter pieces is moved onto an HPGe detector. These actions are performed automatically by a robot. The system is operated at a duty cycle of 1 d sampling, 1 d decay and 1 d counting. Minimum detectable concentrations of radionuclides in air are typically 1Ae10 x 10{sup -6} Bq/m{sup 3}. The station is equipped with various sensors to reveal unauthorized admittance. These sensors can be monitored remotely in real time via Internet or telephone lines. The processes and operation of the station are monitored and partly controlled by computer. The present approach fulfils the requirements of CTBTO for aerosol monitoring. The concept suits well for nuclear material safeguards, too 10 refs.

  19. Technical Note: New methodology for measuring viscosities in small volumes characteristic of environmental chamber particle samples

    Directory of Open Access Journals (Sweden)

    L. Renbaum-Wolff

    2012-10-01

    Full Text Available Herein, a method for the determination of viscosities of small sample volumes is introduced, with important implications for the viscosity determination of particle samples from environmental chambers (used to simulate atmospheric conditions. The amount of sample needed is < 1 μl, and the technique is capable of determining viscosities (η ranging between 10−3 and 103 Pascal seconds (Pa s in samples that cover a range of chemical properties and with real-time relative humidity and temperature control; hence, the technique should be well-suited for determining the viscosities, under atmospherically relevant conditions, of particles collected from environmental chambers. In this technique, supermicron particles are first deposited on an inert hydrophobic substrate. Then, insoluble beads (~1 μm in diameter are embedded in the particles. Next, a flow of gas is introduced over the particles, which generates a shear stress on the particle surfaces. The sample responds to this shear stress by generating internal circulations, which are quantified with an optical microscope by monitoring the movement of the beads. The rate of internal circulation is shown to be a function of particle viscosity but independent of the particle material for a wide range of organic and organic-water samples. A calibration curve is constructed from the experimental data that relates the rate of internal circulation to particle viscosity, and this calibration curve is successfully used to predict viscosities in multicomponent organic mixtures.

  20. Calcium isolation from large-volume human urine samples for 41Ca analysis by accelerator mass spectrometry.

    Science.gov (United States)

    Miller, James J; Hui, Susanta K; Jackson, George S; Clark, Sara P; Einstein, Jane; Weaver, Connie M; Bhattacharyya, Maryka H

    2013-08-01

    Calcium oxalate precipitation is the first step in preparation of biological samples for (41)Ca analysis by accelerator mass spectrometry. A simplified protocol for large-volume human urine samples was characterized, with statistically significant increases in ion current and decreases in interference. This large-volume assay minimizes cost and effort and maximizes time after (41)Ca administration during which human samples, collected over a lifetime, provide (41)Ca:Ca ratios that are significantly above background.

  1. Calcium Isolation from Large-Volume Human Urine Samples for 41Ca Analysis by Accelerator Mass Spectrometry

    Science.gov (United States)

    Miller, James J; Hui, Susanta K; Jackson, George S; Clark, Sara P; Einstein, Jane; Weaver, Connie M; Bhattacharyya, Maryka H

    2013-01-01

    Calcium oxalate precipitation is the first step in preparation of biological samples for 41Ca analysis by accelerator mass spectrometry. A simplified protocol for large-volume human urine samples was characterized, with statistically significant increases in ion current and decreases in interference. This large-volume assay minimizes cost and effort and maximizes time after 41Ca administration during which human samples, collected over a lifetime, provide 41Ca:Ca ratios that are significantly above background. PMID:23672965

  2. Relationship between LIBS Ablation and Pit Volume for Geologic Samples: Applications for in situ Absolute Geochronology

    Science.gov (United States)

    Devismes, D.; Cohen, Barbara A.

    2014-01-01

    In planetary sciences, in situ absolute geochronology is a scientific and engineering challenge. Currently, the age of the Martian surface can only be determined by crater density counting. However this method has significant uncertainties and needs to be calibrated with absolute ages. We are developing an instrument to acquire in situ absolute geochronology based on the K-Ar method. The protocol is based on the laser ablation of a rock by hundreds of laser pulses. Laser Induced Breakdown Spectroscopy (LIBS) gives the potassium content of the ablated material and a mass spectrometer (quadrupole or ion trap) measures the quantity of 40Ar released. In order to accurately measure the quantity of released 40Ar in cases where Ar is an atmospheric constituent (e.g., Mars), the sample is first put into a chamber under high vacuum. The 40Arquantity, the concentration of K and the estimation of the ablated mass are the parameters needed to give the age of the rocks. The main uncertainties with this method are directly linked to the measures of the mass (typically some µg) and of the concentration of K by LIBS (up to 10%). Because the ablated mass is small compared to the mass of the sample, and because material is redeposited onto the sample after ablation, it is not possible to directly measure the ablated mass. Our current protocol measures the ablated volume and estimates the sample density to calculate ablated mass. The precision and accuracy of this method may be improved by using knowledge of the sample's geologic properties to predict its response to laser ablation, i.e., understanding whether natural samples have a predictable relationship between laser energy deposited and resultant ablation volume. In contrast to most previous studies of laser ablation, theoretical equations are not highly applicable. The reasons are numerous, but the most important are: a) geologic rocks are complex, polymineralic materials; b) the conditions of ablation are unusual (for example

  3. Tracer techniques for urine volume determination and urine collection and sampling back-up system

    Science.gov (United States)

    Ramirez, R. V.

    1971-01-01

    The feasibility, functionality, and overall accuracy of the use of lithium were investigated as a chemical tracer in urine for providing a means of indirect determination of total urine volume by the atomic absorption spectrophotometry method. Experiments were conducted to investigate the parameters of instrumentation, tracer concentration, mixing times, and methods for incorporating the tracer material in the urine collection bag, and to refine and optimize the urine tracer technique to comply with the Skylab scheme and operational parameters of + or - 2% of volume error and + or - 1% accuracy of amount of tracer added to each container. In addition, a back-up method for urine collection and sampling system was developed and evaluated. This back-up method incorporates the tracer technique for volume determination in event of failure of the primary urine collection and preservation system. One chemical preservative was selected and evaluated as a contingency chemical preservative for the storage of urine in event of failure of the urine cooling system.

  4. Extended two-photon microscopy in live samples with Bessel beams: steadier focus, faster volume scans, and simpler stereoscopic imaging

    Science.gov (United States)

    Thériault, Gabrielle; Cottet, Martin; Castonguay, Annie; McCarthy, Nathalie; De Koninck, Yves

    2014-01-01

    Two-photon microscopy has revolutionized functional cellular imaging in tissue, but although the highly confined depth of field (DOF) of standard set-ups yields great optical sectioning, it also limits imaging speed in volume samples and ease of use. For this reason, we recently presented a simple and retrofittable modification to the two-photon laser-scanning microscope which extends the DOF through the use of an axicon (conical lens). Here we demonstrate three significant benefits of this technique using biological samples commonly employed in the field of neuroscience. First, we use a sample of neurons grown in culture and move it along the z-axis, showing that a more stable focus is achieved without compromise on transverse resolution. Second, we monitor 3D population dynamics in an acute slice of live mouse cortex, demonstrating that faster volumetric scans can be conducted. Third, we acquire a stereoscopic image of neurons and their dendrites in a fixed sample of mouse cortex, using only two scans instead of the complete stack and calculations required by standard systems. Taken together, these advantages, combined with the ease of integration into pre-existing systems, make the extended depth-of-field imaging based on Bessel beams a strong asset for the field of microscopy and life sciences in general. PMID:24904284

  5. Limitations of mRNA amplification from small-size cell samples

    Directory of Open Access Journals (Sweden)

    Myklebost Ola

    2005-10-01

    Full Text Available Abstract Background Global mRNA amplification has become a widely used approach to obtain gene expression profiles from limited material. An important concern is the reliable reflection of the starting material in the results obtained. This is especially important with extremely low quantities of input RNA where stochastic effects due to template dilution may be present. This aspect remains under-documented in the literature, as quantitative measures of data reliability are most often lacking. To address this issue, we examined the sensitivity levels of each transcript in 3 different cell sample sizes. ANOVA analysis was used to estimate the overall effects of reduced input RNA in our experimental design. In order to estimate the validity of decreasing sample sizes, we examined the sensitivity levels of each transcript by applying a novel model-based method, TransCount. Results From expression data, TransCount provided estimates of absolute transcript concentrations in each examined sample. The results from TransCount were used to calculate the Pearson correlation coefficient between transcript concentrations for different sample sizes. The correlations were clearly transcript copy number dependent. A critical level was observed where stochastic fluctuations became significant. The analysis allowed us to pinpoint the gene specific number of transcript templates that defined the limit of reliability with respect to number of cells from that particular source. In the sample amplifying from 1000 cells, transcripts expressed with at least 121 transcripts/cell were statistically reliable and for 250 cells, the limit was 1806 transcripts/cell. Above these thresholds, correlation between our data sets was at acceptable values for reliable interpretation. Conclusion These results imply that the reliability of any amplification experiment must be validated empirically to justify that any gene exists in sufficient quantity in the input material. This

  6. Limited sampling strategy models for estimating the AUC of gliclazide in Chinese healthy volunteers.

    Science.gov (United States)

    Huang, Ji-Han; Wang, Kun; Huang, Xiao-Hui; He, Ying-Chun; Li, Lu-Jin; Sheng, Yu-Cheng; Yang, Juan; Zheng, Qing-Shan

    2013-06-01

    The aim of this work is to reduce the cost of required sampling for the estimation of the area under the gliclazide plasma concentration versus time curve within 60 h (AUC0-60t ). The limited sampling strategy (LSS) models were established and validated by the multiple regression model within 4 or fewer gliclazide concentration values. Absolute prediction error (APE), root of mean square error (RMSE) and visual prediction check were used as criterion. The results of Jack-Knife validation showed that 10 (25.0 %) of the 40 LSS based on the regression analysis were not within an APE of 15 % using one concentration-time point. 90.2, 91.5 and 92.4 % of the 40 LSS models were capable of prediction using 2, 3 and 4 points, respectively. Limited sampling strategies were developed and validated for estimating AUC0-60t of gliclazide. This study indicates that the implementation of an 80 mg dosage regimen enabled accurate predictions of AUC0-60t by the LSS model. This study shows that 12, 6, 4, 2 h after administration are the key sampling times. The combination of (12, 2 h), (12, 8, 2 h) or (12, 8, 4, 2 h) can be chosen as sampling hours for predicting AUC0-60t in practical application according to requirement.

  7. Bringing biofuels on the market. Options to increase EU biofuels volumes beyond the current blending limits

    Energy Technology Data Exchange (ETDEWEB)

    Kampman, B.; Van Grinsven, A.; Croezen, H. [CE Delft, Delft (Netherlands); Verbeek, R.; Van Mensch, P.; Patuleia, A. [TNO, Delft, (Netherlands)

    2013-07-15

    This handbook on biofuels provides a comprehensive overview of different types of biofuels, and the technical options that exist to market the biofuels volumes expected to be consumed in the EU Member States in 2020. The study concludes that by fully utilizing the current blending limits of biodiesel (FAME) in diesel (B7) and bioethanol in petrol (E10) up to 7.9% share of biofuels in the EU transport sector can be technically reached by 2020. Increasing use of advanced biofuels, particularly blending of fungible fuels into diesel (eg. HVO and BTL) and the use of higher ethanol blends in compatible vehicles (e.g. E20), can play an important role. Also, the increased use of biomethane (in particular bio-CNG) and higher blends of biodiesel (FAME) can contribute. However, it is essential for both governments and industry to decide within 1 or 2 years on the way ahead and take necessary actions covering both, the fuels and the vehicles, to ensure their effective and timely implementation. Even though a range of technical options exist, many of these require considerable time and effort to implement and reach their potential. Large scale implementation of the options beyond current blending limits requires new, targeted policy measures, in many cases complemented by new fuel and vehicle standards, adaptation of engines and fuel distribution, etc. Marketing policies for these vehicles, fuels and blends are also likely to become much more important than in the current situation. Each Member State may develop its own strategy tailored to its market and policy objectives, but the EU should play a crucial facilitating role in these developments.

  8. Statistical power calculation and sample size determination for environmental studies with data below detection limits

    Science.gov (United States)

    Shao, Quanxi; Wang, You-Gan

    2009-09-01

    Power calculation and sample size determination are critical in designing environmental monitoring programs. The traditional approach based on comparing the mean values may become statistically inappropriate and even invalid when substantial proportions of the response values are below the detection limits or censored because strong distributional assumptions have to be made on the censored observations when implementing the traditional procedures. In this paper, we propose a quantile methodology that is robust to outliers and can also handle data with a substantial proportion of below-detection-limit observations without the need of imputing the censored values. As a demonstration, we applied the methods to a nutrient monitoring project, which is a part of the Perth Long-Term Ocean Outlet Monitoring Program. In this example, the sample size required by our quantile methodology is, in fact, smaller than that by the traditional t-test, illustrating the merit of our method.

  9. On state-dependant sampling for nonlinear controlled systems sharing limited computational resources

    OpenAIRE

    Alamir, Mazen

    2007-01-01

    21 pages. soumis à la revue "IEEE Transactions on Automatic Control"; International audience; In this paper, a framework for dynamic monitoring of sampling periods for nonlinear controlled systems is proposed. This framework is particularly adapted to the context of controlled systems sharing limited computational resources. The proposed scheme can be used in a cascaded structure with any feedback scheduling design. Illustrative examples are given to assess the efficiency of the proposed fram...

  10. Determination of reference limits: statistical concepts and tools for sample size calculation.

    Science.gov (United States)

    Wellek, Stefan; Lackner, Karl J; Jennen-Steinmetz, Christine; Reinhard, Iris; Hoffmann, Isabell; Blettner, Maria

    2014-12-01

    Reference limits are estimators for 'extreme' percentiles of the distribution of a quantitative diagnostic marker in the healthy population. In most cases, interest will be in the 90% or 95% reference intervals. The standard parametric method of determining reference limits consists of computing quantities of the form X̅±c·S. The proportion of covered values in the underlying population coincides with the specificity obtained when a measurement value falling outside the corresponding reference region is classified as diagnostically suspect. Nonparametrically, reference limits are estimated by means of so-called order statistics. In both approaches, the precision of the estimate depends on the sample size. We present computational procedures for calculating minimally required numbers of subjects to be enrolled in a reference study. The much more sophisticated concept of reference bands replacing statistical reference intervals in case of age-dependent diagnostic markers is also discussed.

  11. Determination of the efficiency of a detector in gamma spectrometry of large-volume samples

    CERN Document Server

    Tertyshnik, E G

    2012-01-01

    The experimental - calculated method is proposed to determine the full energy peak efficiency (FEPE) of detectors {\\epsilon}(E) in case a measurement of the large-volume samples. Water is used as standard absorber in which the linear attenuation coefficients for photons {\\mu}0 (E) is well known. The value {\\mu} (E) in sample material (matrix of the sample) is determined experimentally by means of spectrometer. The formulas are given for calculation of the ratio {\\epsilon}(E)/ {\\epsilon}0(E), where {\\epsilon}0(E) is FEPE of the detector for photons those are arising in the container filled with water (it is found by adding in the container of the Reference radioactive solutions). To prove the validity of the method ethanol (density 0,8 g/cm3) and water solutions of salts (density 1,2 and 1,5 g/cm3) were used for simulation of the samples with different attenuation coefficients. Standard deviation between experimental and calculated efficiencies has been about 5 %.

  12. Bioequivalence evaluation of two formulations of pidotimod using a limited sampling strategy.

    Science.gov (United States)

    Huang, Ji-Han; Huang, Xiao-Hui; Wang, Kun; Li, Jian-Chun; Xie, Xue-Feng; Shen, Chen-Lin; Li, Lu-Jin; Zheng, Qing-Shan

    2013-07-01

    The aim of this study was to develop a limited sampling strategy (LSS) to assess the bioequivalence of two formulations of pidotimod. A randomized, two-way, cross-over study was conducted in healthy Chinese volunteers to compare two formulations of pidotimod. A limited sampling model was established using regression models to estimate the pharmacokinetic parameters and assess the bioequivalence of pidotimod. The model was internally validated by the Jack-knife method and graphical methods. The traditional non-compartmental method was also used to analyze the data and compared with LSS method. The results indicate that following oral administration of a single 800 mg dose, the plasma AUC(0-12 h) and C(max) of pidotimod can be predicted accurately using only two to four plasma samples. The bioequivalence assessment based on the LSS models provided results very similar to that obtained using all the observed concentration-time data points and indicate that the two pidotimod formulations were bioequivalent. A LSS method for assessing the bioequivalence of pidotimod formulations was established and proved to be applicable and accurate. This LSS method could be considered appropriate for a pidotimod bioequivalence study, providing an inexpensive cost of sampling acquisition and analysis. And the methodology presented here may also be applicable to bioequivalence evaluation of other medications. Crown Copyright © 2013. Published by Elsevier Masson SAS. All rights reserved.

  13. Sweat: a sample with limited present applications and promising future in metabolomics.

    Science.gov (United States)

    Mena-Bravo, A; Luque de Castro, M D

    2014-03-01

    Sweat is a biofluid with present scant use as clinical sample. This review tries to demonstrate the advantages of sweat over other biofluids such as blood or urine for routine clinical analyses and the potential when related to metabolomics. With this aim, critical discussion of sweat samplers and equipment for analysis of target compounds in this sample is made. Well established routine analyses in sweat as is that to diagnose cystic fibrosis, and the advantages and disadvantages of sweat versus urine or blood for doping control have also been discussed. Methods for analytes such as essential metals and xenometals, ethanol and electrolytes in sweat in fact constitute target metabolomics approaches or belong to any metabolomics subdiscipline such as metallomics, ionomics or xenometabolomics. The higher development of biomarkers based on genomics or proteomics as omics older than metabolomics is discussed and also the potential role of metabolomics in systems biology taking into account its emergent implementation. Normalization of the volume of sampled sweat constitutes a present unsolved shortcoming that deserves investigation. Foreseeable trends in this area are outlined. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Precise quantification of dialysis using continuous sampling of spent dialysate and total dialysate volume measurement.

    Science.gov (United States)

    Argilés, A; Ficheux, A; Thomas, M; Bosc, J Y; Kerr, P G; Lorho, R; Flavier, J L; Stec, F; Adelé, C; Leblanc, M; Garred, L J; Canaud, B; Mion, H; Mion, C M

    1997-08-01

    The "gold standard" method to evaluate the mass balances achieved during dialysis for a given solute remains total dialysate collection (TDC). However, since handling over 100 liter volumes is unfeasible in our current dialysis units, alternative methods have been proposed, including urea kinetic modeling, partial dialysate collection (PDC) and more recently, monitoring of dialysate urea by on-line devices. Concerned by the complexity and costs generated by these devices, we aimed to adapt the simple "gold standard" TDC method to clinical practice by diminishing the total volumes to be handled. We describe a new system based on partial dialysate collection, the continuous spent sampling of dialysate (CSSD), and present its technical validation. Further, and for the first time, we report a long-term assessment of dialysis dosage in a dialysis clinic using both the classical PDC and the new CSSD system in a group of six stable dialysis patients who were followed for a period of three years. For the CSSD technique, spent dialysate was continuously sampled by a reversed automatic infusion pump at a rate of 10 ml/hr. The piston was automatically driven by the dialysis machine: switched on when dialysis started, off when dialysis terminated and held during the by pass periods. At the same time the number of production cycles of dialysate was monitored and the total volume of dialysate was calculated by multiplying the volume of the production chamber by the number of cycles. Urea and creatinine concentrations were measured in the syringe and the masses were obtained by multiplying this concentration by the total volume. CSSD and TDC were simultaneously performed in 20 dialysis sessions. The total mass of urea removed was calculated as 58038 and 60442 mmol/session (CSSD and TDC respectively; 3.1 +/- 1.2% variation; r = 0.99; y = 0.92x -28.9; P urea removal: 510 +/- 59 during the first year with PDC and 516 +/- 46 mmol/dialysis session during the third year, using CSSD

  15. Airborne virus sampling: Efficiencies of samplers and their detection limits for infectious bursal disease virus (IBDV

    Directory of Open Access Journals (Sweden)

    Yang Zhao

    2014-09-01

    Full Text Available [b]Introduction[/b]. The airborne transmission of infectious diseases in livestock production is increasingly receiving research attention. Reliable techniques of air sampling are crucial to underpin the findings of such studies. This study evaluated the physical and biological efficiencies and detection limits of four samplers (Andersen 6-stage impactor, all-glass impinger “AGI-30”, OMNI-3000 and MD8 with gelatin filter for collecting aerosols of infectious bursal disease virus (IBDV. [b]Materials and Method[/b]. IBDV aerosols mixed with a physical tracer (uranine were generated in an isolator, and then collected by the bioaerosol samplers. Samplers’ physical and biological efficiencies were derived based on the tracer concentration and the virus/tracer ratio, respectively. Detection limits for the samplers were estimated with the obtained efficiency data. [b]Results.[/b] Physical efficiencies of the AGI-30 (96% and the MD8 (100% were significantly higher than that of the OMNI-3000 (60%. Biological efficiency of the OMNI-3000 (23% was significantly lower than 100% (P < 0.01, indicating inactivation of airborne virus during sampling. The AGI-30, the Andersen impactor and the MD8 did not significantly inactivate virus during sampling. The 2-min detection limits of the samplers on airborne IBDV were 4.1 log[sub]10[/sub] 50% egg infective dose (EID[sub]50[/sub] m [sup]-3[/sup] for the Andersen impactor, 3.3 log[sub]10[/sub] EID50 m [sup]-3[/sup] for the AGI-30, 2.5 log[sub]10[/sub] EID50 m [sup]-3[/sup] for the OMNI-3000, and 2.9 log[sub]10[/sub] EID[sub]50[/sub] m [sup]-3[/sup] for the MD8. The mean half-life of IBDV aerosolized at 20 °C and 70% was 11.9 min. Conclusion. Efficiencies of different samplers vary. Despite its relatively low sampling efficiency, the OMNI-3000 is suitable for use in environments with low viral concentrations because its high flow rate gives a low detection limit. With the 4 samplers investigated, negative air

  16. Performance limitations of label-free sensors in molecular diagnosis using complex samples

    Science.gov (United States)

    Varma, Manoj

    2016-03-01

    Label-free biosensors promised a paradigm involving direct detection of biomarkers from complex samples such as serum without requiring multistep sample processing typical of labelled methods such as ELISA or immunofluorescence assays. Label-free sensors have witnessed decades of development with a veritable zoo of techniques available today exploiting a multitude of physical effects. It is appropriate now to critically assess whether label-free technologies have succeeded in delivering their promise with respect to diagnostic applications, particularly, ambitious goals such as early cancer detection using serum biomarkers, which require low limits of detection (LoD). Comparison of nearly 120 limits of detection (LoD) values reported by labelled and label-free sensing approaches over a wide range of detection techniques and target molecules in serum revealed that labeled techniques achieve 2-3 orders of magnitude better LoDs. Data from experiments where labelled and label-free assays were performed simultaneously using the same assay parameters also confirm that the LoD achieved by labelled techniques is 2 to 3 orders of magnitude better than that by label-free techniques. Furthermore, label-free techniques required significant signal amplification, for e.g. using nanoparticle conjugated secondary antibodies, to achieve LoDs comparable to labelled methods substantially deviating from the original "direct detection" paradigm. This finding has important implications on the practical limits of applying label-free detection methods for molecular diagnosis.

  17. INFLUENCE OF SAMPLE THICKNESS ON ISOTHERMAL CRYSTALLIZATION KINETICS OF POLYMERS IN A CONFINED VOLUME

    Institute of Scientific and Technical Information of China (English)

    Hui Sun; Zhi-ying Zhang; Shi-zhen Wu; Bin Yu; Chang-fa Xiao

    2005-01-01

    Isothermal crystallization process of polymers in a confined volume was simulated in the case of instantaneous nucleation by use of the Monte Carlo method. The influence of sample thickness on some kinetic parameters of crystallization was quantitatively evaluated. It was found that there was a critical thickness value. Influence of thickness on the crystallization behavior was only found for samples of thickness near and less than the critical value. For thick samples the Avrami plot showed straight lines with a turning point at the late stage of crystallization due to the secondary crystallization. When the thickness was near or less than the critical value a primary turning point appeared in the Avrami plot at the very beginning of the crystallization process. A model was proposed to explain the mechanism of this phenomenon. According to this model the critical thickness value is related to the nucleation density or the average distance between adjacent nuclei, and the primary turning point is an indication of a transformation of crystal growth geometry from a three-dimensional mode to a two-dimensional one. Analysis of experimental results of PEO isothermally crystallized at 53.5℃ was consistent with the proposed model.

  18. Limited sampling strategy in rats to predict the inhibited activities of hepatic CYP3A.

    Science.gov (United States)

    Zhu, Xue-Hui; Jiao, Jian-Jie; Zhang, Cai-Li; Lou, Jian-Shi; Liu, Chang-Xiao

    2009-07-01

    The present study was undertaken in order to evaluate feasibility of a limited sampling strategy (LSS) to predict the systemic clearance of midazolam (MDZ), which is a hepatic CYP3A activity phenotyping probe. Groups of rats pretreated with or without serial doses of ketoconazole, which is a selective inhibitor on CYP3A, were used as training set. Linear regression analysis and a Jack-knife validation procedure were performed based on plasma MDZ concentrations at specific time points after sublingual vein injection of MDZ to establish the most informative LSS equations for accurately estimating the clearance of MDZ. Another group of rats in the same setting was used as the validation set to confirm the individual values of estimated clearance (Clest) that were derived from the predictive equations developed in the training set. LSS that were derived from one, two or three sampling times, namely 90 min, 60-90 min, 30-60-90 min and 30-60-120 min, gave the best correlation and acceptable errors between the values of observed clearance (Clobs) and Clest and were chosen to evaluate hepatic CYP3A activity. Our results supported the hypothesis that using limited plasma sampling is simpler than the usual method of estimating CYP3A phenotyping by predicting the systemic clearance of MDZ when the hepatic activity of CYP3A is reduced in the rat. This experimental design offers opportunities to reduce animal use in the study of drug metabolism.

  19. A distance limited sample of massive star forming cores from the RMS survey

    CERN Document Server

    Maud, L T; Moore, T J T; Mottram, J C; Urquhart, J S; Cicchini, A

    2015-01-01

    We analyse C$^{18}$O ($J=3-$2) data from a sample of 99 infrared-bright massive young stellar objects (MYSOs) and compact HII regions that were identified as potential molecular-outflow sources in the Red MSX source (RMS) survey. We extract a distance limited (D $<$ 6 kpc) sample shown to be representative of star formation covering the transition between the source types. At the spatial resolution probed, Larson-like relationships are found for these cores, though the alternative explanation, that Larson's relations arise where surface-density-limited samples are considered, is also consistent with our data. There are no significant differences found between source properties for the MYSOs and HII regions, suggesting that the core properties are established prior to the formation of massive stars, which subsequently have little impact at the later evolutionary stages investigated. There is a strong correlation between dust-continuum and C$^{18}$O-gas masses, supporting the interpretation that both trace t...

  20. SAMPLING ARTIFACTS IN MEASUREMENT OF ELEMENTAL AND ORGANIC CARBON: LOW VOLUME SAMPLING IN INDOOR AND OUTDOOR ENVIRONMENTS

    Science.gov (United States)

    Experiments were completed to determine the extent of artifacts from sampling elemental carbon (EC) and organic carbon (OC) under sample conditions consistent with personal sampling. Two different types of experiments were completed; the first examined possible artifacts from oil...

  1. Limitations and pitfalls in measurements of right ventricular stroke volume in an animal model of right heart failure.

    Science.gov (United States)

    Vildbrad, Mads Dam; Andersen, Asger; Andersen, Thomas Krarup; Axelgaard, Sofie; Holmboe, Sarah; Andersen, Stine; Ringgaard, Steffen; Nielsen-Kudsk, Jens Erik

    2015-05-01

    Right heart failure occurs in various heart and pulmonary vascular diseases and may be fatal. We aimed to identify limitations in non-invasive measurements of right ventricular stroke volume in an animal model of right ventricular failure. Data from previous studies randomising rats to pulmonary trunk banding (PTB, n = 33) causing pressure-overload right ventricular failure or sham operation (n = 16) was evaluated retrospectively. We measured right ventricular stroke volume by high frequency echocardiography and magnetic resonance imaging (MRI). We found correlation between right ventricular stroke volume measured by echocardiography and MRI in the sham animals (r = 0.677, p = 0.004) but not in the PTB group. Echocardiography overestimated the stroke volume compared to MRI in both groups. Intra- and inter-observer variation did not explain the difference. Technical, physiological and anatomical issues in the pulmonary artery might explain why echocardiography over-estimates stroke volume. Flow acceleration close to the pulmonary artery banding can cause uncertainties in the PTB model and might explain the lack of correlation. In conclusion, we found a correlation in right ventricular stroke volume measured by echocardiography versus MRI in the sham group but not the PTB group. Echocardiography overestimated right ventricular stroke volume compared to MRI.

  2. Limiter

    Science.gov (United States)

    Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

    1984-10-19

    A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

  3. A limited sampling schedule to estimate mycophenolic Acid area under the concentration-time curve in hematopoietic cell transplantation recipients.

    Science.gov (United States)

    Li, Hong; Mager, Donald E; Bemer, Meagan J; Salinger, David H; Vicini, Paolo; Sandmaier, Brenda M; Nash, Richard; McCune, Jeannine S

    2012-11-01

    Mycophenolate mofetil (MMF) is a key component of postgrafting immunosuppression in hematopoietic cell transplant (HCT) recipients. The plasma area under the curve (AUC) of its active metabolite, mycophenolic acid (MPA), is associated with MMF efficacy and toxicity. This study developed a population pharmacokinetic model of MPA in HCT recipients and created limited sampling schedules (LSSs) to enable individualized pharmacotherapy. A retrospective evaluation of MPA concentration-time data following a 2-hour MMF intravenous (IV) infusion was conducted in 77 HCT recipients. The final model consisted of 1 and 2 compartments for MMF and MPA pharmacokinetics, respectively. The mean estimated values (coefficient of variation, %) for total systemic clearance, distributional clearance, and central and peripheral compartment volumes of MPA were 36.9 L/h (34.5%), 15.3 L/h (80.4%), 11.9 L (71.7%), and 182 L (127%), respectively. No covariates significantly explained variability among individuals. Optimal LSSs were derived using a simulation approach based on the scaled mean squared error. A 5-sample schedule of 2, 2.5, 3, 5, and 6 hours from the start of the infusion precisely estimated MPA AUC(0-12 h) for Q12-hour IV MMF. A comparable schedule (2, 2.5, 3, 4, and 6 hours) similarly estimated MPA AUC(0-8) (h) for Q8-hour dosing.

  4. Mass Limit for the standard model Higgs boson with the full LEP I ALEPH data sample

    CERN Document Server

    Buskulic, Damir; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Nief, J Y; Odier, P; Pietrzyk, B; Casado, M P; Chmeissani, M; Crespo, J M; Delfino, M C; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Garrido, L; Juste, A; Martínez, M; Orteu, S; Padilla, C; Park, I C; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Alemany, R; Bazarko, A O; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Lutters, G; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Mir, L M; Moneta, L; Oest, T; Pacheco, A; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schmitt, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wagner, A; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Rossignol, J M; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Casper, David William; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Knowles, I G; Lynch, J G; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Teixeira-Dias, P; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Abbaneo, D; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Moutoussi, A; Nash, J; Sedgbeer, J K; Stacey, A M; Williams, M D; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Betteridge, A P; Bowdery, C K; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Williams, M I; Galla, A; Giehl, I; Greene, A M; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Konstantinidis, N P; Payre, P; Rousseau, D; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Aleppo, M; Ragusa, F; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Choi, Y; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Park, H J; Schune, M H; Simion, S; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Verdini, P G; Walsh, J; Blair, G A; Bryant, L M; Cerutti, F; Chambers, J T; Gao, Y; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Maley, P; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Boswell, R; Brew, C A J; Cartwright, S L; Combley, F; Köksal, A; Lehto, M H; Newton, W M; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Büscher, V; Cowan, G D; Grupen, Claus; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Greening, T C; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G

    1996-01-01

    background from the electroweak process e+e- --> l+ l- q qbar. This search results in a 95% C.L. lower limit on the Higgs boson mass of $63.9$~\\Gcs. The reaction e+e- --> HZ* is used to search for the standard model Higgs boson in the H nu nubar and the H l+ l- channels. The data sample corresponds to about 4.5 million hadronic Z decays collected by the ALEPH experiment at LEP from 1989 to 1995 at centre-of-mass energies at and around the Z peak. Three candidate events are found in the H mu+ mu- channel, in agreement with the expected

  5. The role of the upper sample size limit in two-stage bioequivalence designs.

    Science.gov (United States)

    Karalis, Vangelis

    2013-11-01

    Two-stage designs (TSDs) are currently recommended by the regulatory authorities for bioequivalence (BE) assessment. The TSDs presented until now rely on an assumed geometric mean ratio (GMR) value of the BE metric in stage I in order to avoid inflation of type I error. In contrast, this work proposes a more realistic TSD design where sample re-estimation relies not only on the variability of stage I, but also on the observed GMR. In these cases, an upper sample size limit (UL) is introduced in order to prevent inflation of type I error. The aim of this study is to unveil the impact of UL on two TSD bioequivalence approaches which are based entirely on the interim results. Monte Carlo simulations were used to investigate several different scenarios of UL levels, within-subject variability, different starting number of subjects, and GMR. The use of UL leads to no inflation of type I error. As UL values increase, the % probability of declaring BE becomes higher. The starting sample size and the variability of the study affect type I error. Increased UL levels result in higher total sample sizes of the TSD which are more pronounced for highly variable drugs.

  6. Liquid Metering Centrifuge Sticks (LMCS): A Centrifugal Approach to Metering Known Sample Volumes for Colorimetric Solid Phase Extraction (C-SPE)

    Science.gov (United States)

    Gazda, Daniel B.; Schultz, John R.; Clarke, Mark S.

    2007-01-01

    Phase separation is one of the most significant obstacles encountered during the development of analytical methods for water quality monitoring in spacecraft environments. Removing air bubbles from water samples prior to analysis is a routine task on earth; however, in the absence of gravity, this routine task becomes extremely difficult. This paper details the development and initial ground testing of liquid metering centrifuge sticks (LMCS), devices designed to collect and meter a known volume of bubble-free water in microgravity. The LMCS uses centrifugal force to eliminate entrapped air and reproducibly meter liquid sample volumes for analysis with Colorimetric Solid Phase Extraction (C-SPE). C-SPE is a sorption-spectrophotometric platform that is being developed as a potential spacecraft water quality monitoring system. C-SPE utilizes solid phase extraction membranes impregnated with analyte-specific colorimetric reagents to concentrate and complex target analytes in spacecraft water samples. The mass of analyte extracted from the water sample is determined using diffuse reflectance (DR) data collected from the membrane surface and an analyte-specific calibration curve. The analyte concentration can then be calculated from the mass of extracted analyte and the volume of the sample analyzed. Previous flight experiments conducted in microgravity conditions aboard the NASA KC-135 aircraft demonstrated that the inability to collect and meter a known volume of water using a syringe was a limiting factor in the accuracy of C-SPE measurements. Herein, results obtained from ground based C-SPE experiments using ionic silver as a test analyte and either the LMCS or syringes for sample metering are compared to evaluate the performance of the LMCS. These results indicate very good agreement between the two sample metering methods and clearly illustrate the potential of utilizing centrifugal forces to achieve phase separation and metering of water samples in microgravity.

  7. Petrophysical studies of north American carbonate rock samples and evaluation of pore-volume compressibility models

    Science.gov (United States)

    da Silva, Gilberto Peixoto; Franco, Daniel R.; Stael, Giovanni C.; da Costa de Oliveira Lima, Maira; Sant'Anna Martins, Ricardo; de Moraes França, Olívia; Azeredo, Rodrigo B. V.

    2015-12-01

    In this work, we evaluate two pore volume compressibility models that are currently discussed in the literature (Horne, 1990; Jalalh, 2006b). Five groups of carbonate rock samples from the three following sedimentary basins in North America that are known for their association with hydrocarbon deposits were selected for this study: (i) the Guelph Formation of the Michigan Basin (Middle Silurian); (ii) the Edwards Formation of the Central Texas Platform (Middle Cretaceous); and (iii) the Burlington-Keokuk Formation of the Mississippian System (Lower Mississippian). In addition to the evaluation of the compressibility model, a petrophysical evaluation of these rock samples was conducted. Additional characterizations, such as grain density, the effective porosity, absolute grain permeability, thin section petrography, MICP and NMR, were performed to complement constant pore-pressure compressibility tests. Although both models presented an overall good representation of the compressibility behavior of the studied carbonate rocks, even when considering their broad porosity range (~ 2-38%), the model proposed by Jalalh (2006b) performed better with a confidence level of 95% and a prediction interval of 68%.

  8. Using machine learning tools to model complex toxic interactions with limited sampling regimes.

    Science.gov (United States)

    Bertin, Matthew J; Moeller, Peter; Guillette, Louis J; Chapman, Robert W

    2013-03-19

    A major impediment to understanding the impact of environmental stress, including toxins and other pollutants, on organisms, is that organisms are rarely challenged by one or a few stressors in natural systems. Thus, linking laboratory experiments that are limited by practical considerations to a few stressors and a few levels of these stressors to real world conditions is constrained. In addition, while the existence of complex interactions among stressors can be identified by current statistical methods, these methods do not provide a means to construct mathematical models of these interactions. In this paper, we offer a two-step process by which complex interactions of stressors on biological systems can be modeled in an experimental design that is within the limits of practicality. We begin with the notion that environment conditions circumscribe an n-dimensional hyperspace within which biological processes or end points are embedded. We then randomly sample this hyperspace to establish experimental conditions that span the range of the relevant parameters and conduct the experiment(s) based upon these selected conditions. Models of the complex interactions of the parameters are then extracted using machine learning tools, specifically artificial neural networks. This approach can rapidly generate highly accurate models of biological responses to complex interactions among environmentally relevant toxins, identify critical subspaces where nonlinear responses exist, and provide an expedient means of designing traditional experiments to test the impact of complex mixtures on biological responses. Further, this can be accomplished with an astonishingly small sample size.

  9. Simultaneous SEEG-MEG-EEG recordings Overcome the SEEG limited spatial sampling.

    Science.gov (United States)

    Gavaret, Martine; Dubarry, Anne-Sophie; Carron, Romain; Bartolomei, Fabrice; Trébuchon, Agnès; Bénar, Christian-George

    2016-12-01

    During presurgical evaluation of pharmacoresistant partial epilepsies, stereoelectroencephalography (SEEG) records interictal and ictal activities directly but is inherently limited in spatial sampling. In contrast, scalp-EEG and MEG are less sensitive but provide a global view on brain activity. Therefore, recording simultaneously these three modalities should provide a better understanding of the underlying brain sources by taking advantage of the different sensitivities of the three recording techniques. We performed trimodal EEG-MEG-SEEG recordings in a 19-year-old woman with pharmacoresistant cryptogenic posterior cortex epilepsy. Sub-continuous and highly focal spikes that were not visible at the surface were marked on SEEG by an epileptologist. Surface signals, MEG and scalp-EEG, were then averaged locked on SEEG spikes. MEG sources were reconstructed based on a moving dipole approach (Brainstorm software). This analysis revealed source within the left occipital pole, located posteriorly to the SEEG leads presenting the maximal number of spikes, in a region not explored by SEEG. In summary, simultaneous recordings provide a new framework for obtaining a view on brain signals that is both local and global, thereby overcoming the inherent SEEG limited spatial sampling. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Detection limit of Clostridium botulinum spores in dried mushroom samples sourced from China.

    Science.gov (United States)

    Malakar, Pradeep K; Plowman, June; Aldus, Clare F; Xing, Zengtao; Zhao, Yong; Peck, Michael W

    2013-08-16

    A survey of dried mushrooms (Lentinula edodes (Shiitake) and Auricularia auricula (Wood Ear)) sourced from China was carried out to determine the natural contamination of these mushrooms with spores of proteolytic Clostridium botulinum and non-proteolytic C. botulinum. The mushrooms were collected from supermarkets and retailers in 21 cities in China during October 2008. Spore loads of C. botulinum in mushrooms have a degree of uncertainty and variability and this study contributes valuable data for determining prevalence of spores of C. botulinum in mushrooms. An optimized detection protocol that combined selective enrichment culture with multiplex PCR was used to test for spores of proteolytic and non-proteolytic C. botulinum. Detection limits were calculated, using a maximum likelihood protocol, from mushroom samples inoculated with defined numbers of spores of proteolytic C. botulinum or non-proteolytic C. botulinum. Based on the maximum likelihood detection limit, it is estimated that dried mushroom A. auricula contained <550spores/kg of proteolytic C. botulinum, and <350spores/kg of non-proteolytic C. botulinum. Dried L. edodes contained <1500spores/kg of proteolytic C. botulinum and it was not possible to determine reliable detection limits for spores of non-proteolytic C. botulinum using the current detection protocol.

  11. Complex-shaped hardened parts fatigue limit prediction according to the witness sample study results

    Science.gov (United States)

    Surgutanova, Yu N.; Mikushev, N. N.; Surgutanov, N. A.; Kiselev, P. E.; Shlyapnikov, P. A.; Meshcheryakova, A. A.

    2016-11-01

    The aim of this study is to investigate the possibility of assessment of the effect of preparatory surface plastic deformation by hydraulic shot blasting on the fatigue strength of cylindrical parts of different diameters (10-40 mm) of D16T alloy with circular notches of semicircular section, based on measurements of residual stress (initial deformations) of a witness sample. The residual stresses of smooth parts were used to calculate the residual stresses of parts with stress raisers. These were used to predict the increment of these parts fatigue limit caused by hardening hydraulic shot blasting. It was found that the highest compressive residual stresses in the smooth parts obtained through calculations differ from the observed values not more than by 7%, and in notched parts by 8%. Using the criterion of mean integral residual stresses, we calculate the increments of the fatigue limit of parts due to superficial hardening. The discrepancy between the experimental and calculated increment values of the fatigue limit of hardened parts with raisers does not exceed 17%.

  12. Desorption of Herbicides from Atmospheric Particulates During High-Volume Air Sampling

    Directory of Open Access Journals (Sweden)

    Dwight V. Quiring

    2011-11-01

    Full Text Available Pesticides can be present in the atmosphere either as vapours and/or in association with suspended particles. High-volume air sampling, in which air is aspirated first through a glass fibre filter to capture pesticides associated with atmospheric particulates and then polyurethane foam (PUF, often in combination with an adsorbent resin such as XAD-2, to capture pesticides present as vapours, is generally employed during atmospheric monitoring for pesticides. However, the particulate fraction may be underestimated because some pesticides may be stripped or desorbed from captured particulates due to the pressure drop created by the high flow of air through the filter. This possibility was investigated with ten herbicide active ingredients commonly used on the Canadian prairies (dimethylamine salts of 2,4-D, MCPA and dicamba, 2,4-D 2-ethylhexyl ester, bromoxynil octanoate, diclofop methyl ester, fenoxaprop ethyl ester, trifluralin, triallate and ethalfluralin and seven hydrolysis products (2,4-D, MCPA, dicamba, bromoxynil, diclofop, clopyralid and mecoprop. Finely ground heavy clay soil fortified with active ingredients/hydrolysis products was evenly distributed on the glass fibre filters of high-volume air samplers and air aspirated through the samplers at a flow rate of 12.5 m3/h for a 7-day period. The proportion desorbed as vapour from the fortified soil was determined by analysis of the PUF/XAD-2 resin composite cartridges. The extent of desorption from the fortified soil applied to the filters varied from 0% for each of the dimethylamine salts of 2,4-D, MCPA and dicamba to approximately 50% for trifluralin, triallate and ethalfluralin.

  13. Digital Droplet Multiple Displacement Amplification (ddMDA for Whole Genome Sequencing of Limited DNA Samples.

    Directory of Open Access Journals (Sweden)

    Minsoung Rhee

    Full Text Available Multiple displacement amplification (MDA is a widely used technique for amplification of DNA from samples containing limited amounts of DNA (e.g., uncultivable microbes or clinical samples before whole genome sequencing. Despite its advantages of high yield and fidelity, it suffers from high amplification bias and non-specific amplification when amplifying sub-nanogram of template DNA. Here, we present a microfluidic digital droplet MDA (ddMDA technique where partitioning of the template DNA into thousands of sub-nanoliter droplets, each containing a small number of DNA fragments, greatly reduces the competition among DNA fragments for primers and polymerase thereby greatly reducing amplification bias. Consequently, the ddMDA approach enabled a more uniform coverage of amplification over the entire length of the genome, with significantly lower bias and non-specific amplification than conventional MDA. For a sample containing 0.1 pg/μL of E. coli DNA (equivalent of ~3/1000 of an E. coli genome per droplet, ddMDA achieves a 65-fold increase in coverage in de novo assembly, and more than 20-fold increase in specificity (percentage of reads mapping to E. coli compared to the conventional tube MDA. ddMDA offers a powerful method useful for many applications including medical diagnostics, forensics, and environmental microbiology.

  14. High resolution triple resonance micro magic angle spinning NMR spectroscopy of nanoliter sample volumes.

    Science.gov (United States)

    Brauckmann, J Ole; Janssen, J W G Hans; Kentgens, Arno P M

    2016-02-14

    To be able to study mass-limited samples and small single crystals, a triple resonance micro-magic angle spinning (μMAS) probehead for the application of high-resolution solid-state NMR of nanoliter samples was developed. Due to its excellent rf performance this allows us to explore the limits of proton NMR resolution in strongly coupled solids. Using homonuclear decoupling we obtain unprecedented (1)H linewidths for a single crystal of glycine (Δν(CH2) = 0.14 ppm) at high field (20 T) in a directly detected spectrum. The triple channel design allowed the recording of high-resolution μMAS (13)C-(15)N correlations of [U-(13)C-(15)N] arginine HCl and shows that the superior (1)H resolution opens the way for high-sensitivity inverse detection of heteronuclei even at moderate spinning speeds and rf-fields. Efficient decoupling leads to long coherence times which can be exploited in many correlation experiments.

  15. Technique for bone volume measurement from human femur head samples by classification of micro-CT image histograms

    Directory of Open Access Journals (Sweden)

    Franco Marinozzi

    2013-09-01

    Full Text Available INTRODUCTION: Micro-CT analysis is a powerful technique for a non-invasive evaluation of the morphometric parameters of trabecular bone samples. This elaboration requires a previous binarization of the images. A problem which arises from the binarization process is the partial volume artifact. Voxels at the external surface of the sample can contain both bone and air so thresholding operates an incorrect estimation of volume occupied by the two materials. AIM: The aim of this study is the extraction of bone volumetric information directly from the image histograms, by fitting them with a suitable set of functions. METHODS: Nineteen trabecular bone samples were extracted from femoral heads of eight patients subject to a hip arthroplasty surgery. Trabecular bone samples were acquired using micro-CT Scanner. Hystograms of the acquired images were computed and fitted by Gaussian-like functions accounting for: a gray levels produced by the bone x-ray absorption, b the portions of the image occupied by air and c voxels that contain a mixture of bone and air. This latter contribution can be considered such as an estimation of the partial volume effect. RESULTS: The comparison of the proposed technique to the bone volumes measured by a reference instrument such as by a helium pycnometer show the method as a good way for an accurate bone volume calculation of trabecular bone samples.

  16. Integration of monolithic porous polymer with droplet-based microfluidics on a chip for nano/picoliter volume sample analysis

    OpenAIRE

    Kim, Jin-Young; Chang, Soo-Ik; Andrew J deMello; O’Hare, Danny

    2014-01-01

    In this paper, a porous polymer nanostructure has been integrated with droplet-based microfluidics in a single planar format. Monolithic porous polymer (MPP) was formed selectively within a microfluidic channel. The resulting analyte bands were sequentially comartmentalised into droplets. This device reduces band broadening and the effects of post-column dead volume by the combination of the two techniques. Moreover it offers the precise control of nano/picoliter volume samples.

  17. Relationship Between LIBS Ablation and Pit Volume for Geologic Samples: Applications for the In Situ Absolute Geochronology

    Science.gov (United States)

    Devismes, Damien; Cohen, Barbara; Miller, J.-S.; Gillot, P.-Y.; Lefevre, J.-C.; Boukari, C.

    2014-01-01

    These first results demonstrate that LIBS spectra can be an interesting tool to estimate the ablated volume. When the ablated volume is bigger than 9.10(exp 6) cubic micrometers, this method has less than 10% of uncertainties. Far enough to be directly implemented in the KArLE experiment protocol. Nevertheless, depending on the samples and their mean grain size, the difficulty to have homogeneous spectra will increase with the ablated volume. Several K-Ar dating studies based on this approach will be implemented. After that, the results will be shown and discussed.

  18. A Prospective Randomized Study of the Radiotherapy Volume for Limited-stage Small Cell Lung Cancer: A Preliminary Report

    Directory of Open Access Journals (Sweden)

    Xiao HU

    2010-07-01

    Full Text Available Background and objective Controversies exists with regard to target volumes as far as thoracic radiotherapy (TRT is concerned in the multimodality treatment for limited-stage small cell lung cancer (LSCLC. The aim of this study is to prospectively compare the local control rate, toxicity profiles, and overall survival (OS between patients received different target volumes irradiation after induction chemotherapy. Methods LSCLC patients received 2 cycles of etoposide and cisplatin (EP induction chemotherapy and were randomly assigned to receive TRT to either the post- or pre-chemotherapy tumor extent (GTV-T as study arm and control arm, CTV-N included the positive nodal drainage area for both arms. One to 2 weeks after induction chemotherapy, 45 Gy/30 Fx/19 d TRT was administered concurrently with the third cycle of EP regimen. After that, additional 3 cycles of EP consolidation were administered. Prophylactic cranial irradiation (PCI was administered to patients with a complete response. Results Thirty-seven and 40 patients were randomly assigned to study arm and control arm. The local recurrence rates were 32.4% and 28.2% respectively (P=0.80; the isolated nodal failure (INF rate were 3.0% and 2.6% respectively (P=0.91; all INF sites were in the ipsilateral supraclavicular fossa. Medastinal N3 disease was the risk factor for INF (P=0.02, OR=14.13, 95%CI: 1.47-136.13. During radiotherapy, grade I, II weight loss was observed in 29.4%, 5.9% and 56.4%, 7.7% patients respectively (P=0.04. Grade 0-I and II-III late pulmonary injury was developed in 97.1%, 2.9% and 86.4%, 15.4% patients respectively (P=0.07. Median survival time was 22.1 months and 26.9 months respectively. The 1 to 3-year OS were 77.9%, 44.4%, 37.3% and 75.8%, 56.3%, 41.7% respectively (P=0.79. Conclusion The preliminary results of this study indicate that irradiant the post-chemotherapy tumor extent (GTV-T and positive nodal drainage area did not decrease local control and overall

  19. Development and validation of limited-sampling strategies for predicting amoxicillin pharmacokinetic and pharmacodynamic parameters.

    Science.gov (United States)

    Suarez-Kurtz, G; Ribeiro, F M; Vicente, F L; Struchiner, C J

    2001-11-01

    Amoxicillin plasma concentrations (n = 1,152) obtained from 48 healthy subjects in two bioequivalence studies were used to develop limited-sampling strategy (LSS) models for estimating the area under the concentration-time curve (AUC), the maximum concentration of drug in plasma (C(max)), and the time interval of concentration above MIC susceptibility breakpoints in plasma (T>MIC). Each subject received 500-mg amoxicillin, as reference and test capsules or suspensions, and plasma concentrations were measured by a validated microbiological assay. Linear regression analysis and a "jack-knife" procedure revealed that three-point LSS models accurately estimated (R(2), 0.92; precision, MICs of 0.25 or 2.0 microg/ml, which are representative of microorganisms susceptible and resistant to amoxicillin.

  20. Coupling sample paths to the partial thermodynamic limit in stochastic chemical reaction networks

    CERN Document Server

    Levien, Ethan

    2016-01-01

    We present a new technique for reducing the variance in Monte Carlo estimators of stochastic chemical reaction networks. Our method makes use of the fact that many stochastic reaction networks converge to piecewise deterministic Markov processes in the large system-size limit. The statistics of the piecewise deterministic process can be obtained much more efficiently than those of the exact process. By coupling sample paths of the exact model to the piecewise deterministic process we are able to reduce the variance, and hence the computational complexity of the Monte Carlo estimator. In addition to rigorous results concerning the asymptotic behavior of our method, numerical simulations are performed on some simple biological models suggesting that significant computational gains are made for even moderate system-sizes.

  1. Efficient Sampling of Band-limited Signals from Sine Wave Crossings

    CERN Document Server

    Selva, J

    2010-01-01

    This paper presents an efficient method for reconstructing a band-limited signal in the discrete domain from its crossings with a sine wave. The method makes it possible to design A/D converters that only deliver the crossing timings, which are then used to interpolate the input signal at arbitrary instants. Potentially, it may allow for reductions in power consumption and complexity, as well as for an increase in the achievable sampling bandwidth. The reconstruction in the discrete domain is based on a recently-proposed modification of the Lagrange interpolator, which is readily implementable with linear complexity and efficiently, given that it re-uses known schemes for variable fractional-delay (VFD) filters. As a spin-off, the method allows one to perform spectral analysis from sine wave crossings with the complexity of the FFT. Finally, the results in the paper are validated in a numerical example.

  2. A Central Limit Theorem for the Volumes of High Excursions of Stationary Associated Random Fields

    Directory of Open Access Journals (Sweden)

    Vadim Demichev

    2015-05-01

    Full Text Available We prove that under certain conditions the excursion sets volumes of stationary positively associated random fields converge after rescaling to the normal distribution as the excursion level and the size of the observation window grow. In addition, we provide a number of examples.

  3. Relationship between sample volumes and modulus of human vertebral trabecular bone in micro-finite element analysis.

    Science.gov (United States)

    Wen, Xin-Xin; Xu, Chao; Zong, Chun-Lin; Feng, Ya-Fei; Ma, Xiang-Yu; Wang, Fa-Qi; Yan, Ya-Bo; Lei, Wei

    2016-07-01

    Micro-finite element (μFE) models have been widely used to assess the biomechanical properties of trabecular bone. How to choose a proper sample volume of trabecular bone, which could predict the real bone biomechanical properties and reduce the calculation time, was an interesting problem. Therefore, the purpose of this study was to investigate the relationship between different sample volumes and apparent elastic modulus (E) calculated from μFE model. 5 Human lumbar vertebral bodies (L1-L5) were scanned by micro-CT. Cubic concentric samples of different lengths were constructed as the experimental groups and the largest possible volumes of interest (VOI) were constructed as the control group. A direct voxel-to-element approach was used to generate μFE models and steel layers were added to the superior and inferior surface to mimic axial compression tests. A 1% axial strain was prescribed to the top surface of the model to obtain the E values. ANOVA tests were performed to compare the E values from the different VOIs against that of the control group. Nonlinear function curve fitting was performed to study the relationship between volumes and E values. The larger cubic VOI included more nodes and elements, and more CPU times were needed for calculations. E values showed a descending tendency as the length of cubic VOI decreased. When the volume of VOI was smaller than (7.34mm(3)), E values were significantly different from the control group. The fit function showed that E values approached an asymptotic values with increasing length of VOI. Our study demonstrated that apparent elastic modulus calculated from μFE models were affected by the sample volumes. There was a descending tendency of E values as the length of cubic VOI decreased. Sample volume which was not smaller than (7.34mm(3)) was efficient enough and timesaving for the calculation of E.

  4. Sampling small volumes of ambient ammonia using a miniaturized gas sampler.

    Science.gov (United States)

    Timmer, Björn; Olthuis, Wouter; van den Berg, Albert

    2004-06-01

    The development of a gas sampler for a miniaturized ambient ammonia detector is described. A micromachined channel system is realized in glass and silicon using powder blasting and anodic bonding. The analyte gas is directly mixed with purified water, dissolving the ammonia that will dissociate into ammonium ions. Carrier gas bubbles are subsequently removed from the liquid stream through a venting hole sealed with a microporous water repellent PTFE membrane. A flow restrictor is placed at the outlet of the sampler to create a small overpressure underneath the membrane, enabling the gas to leave through the membrane. Experiments with a gas flow of 1 ml min(-1), containing ammonia concentrations ranging from 9.4 ppm to 0.6 ppm in a nitrogen carrier flow have been carried out, at a water flow of 20 microl min(-1). The ammonium concentration in the sample solution is measured with an electrolyte conductivity detector. The measured values correspond with the concentration calculated from the initial ammonia concentration in the analyte gas, the fifty times concentration enhancement due to the gas-liquid volume difference and the theoretical dissociation equilibrium as a function of the resulting pH.

  5. High-resolution liquid- and solid-state nuclear magnetic resonance of nanoliter sample volumes using microcoil detectors

    Science.gov (United States)

    Kentgens, A. P. M.; Bart, J.; van Bentum, P. J. M.; Brinkmann, A.; van Eck, E. R. H.; Gardeniers, J. G. E.; Janssen, J. W. G.; Knijn, P.; Vasa, S.; Verkuijlen, M. H. W.

    2008-02-01

    The predominant means to detect nuclear magnetic resonance (NMR) is to monitor the voltage induced in a radiofrequency coil by the precessing magnetization. To address the sensitivity of NMR for mass-limited samples it is worthwhile to miniaturize this detector coil. Although making smaller coils seems a trivial step, the challenges in the design of microcoil probeheads are to get the highest possible sensitivity while maintaining high resolution and keeping the versatility to apply all known NMR experiments. This means that the coils have to be optimized for a given sample geometry, circuit losses should be avoided, susceptibility broadening due to probe materials has to be minimized, and finally the B1-fields generated by the rf coils should be homogeneous over the sample volume. This contribution compares three designs that have been miniaturized for NMR detection: solenoid coils, flat helical coils, and the novel stripline and microslot designs. So far most emphasis in microcoil research was in liquid-state NMR. This contribution gives an overview of the state of the art of microcoil solid-state NMR by reviewing literature data and showing the latest results in the development of static and micro magic angle spinning (microMAS) solenoid-based probeheads. Besides their mass sensitivity, microcoils can also generate tremendously high rf fields which are very useful in various solid-state NMR experiments. The benefits of the stripline geometry for studying thin films are shown. This geometry also proves to be a superior solution for microfluidic NMR implementations in terms of sensitivity and resolution.

  6. Role of Ito's lemma in sampling pinned diffusion paths in the continuous-time limit

    Science.gov (United States)

    Malsom, P. J.; Pinski, F. J.

    2016-10-01

    We consider pinned diffusion paths that are explored by a particle moving via a conservative force while being in thermal equilibrium with its surroundings. To probe rare transitions, we use the Onsager-Machlup (OM) functional as a path probability distribution function for transition paths that are constrained to start and stop at predesignated points in different energy basins after a fixed time. The OM theory is based on a discrete-time version of Brownian dynamics, and thus it possesses a finite number of time steps. Here we explore the continuous-time limit where the number of time steps, and hence the dimensionality, becomes infinite. In this regime, the OM functional has been commonly regularized by using the Ito-Girsanov change of measure. This regularized form can then be used as a basis of a numerical algorithm to probe transition paths. In doing so, time again is discretized, progressing in fixed increments. When sampling paths, we find that numerical schemes based on this regularized continuous-time limit can fail catastrophically in describing the path of a particle moving in a potential with multiple wells. The origin of this behavior is traced to numerical instabilities in the discrete version of the continuous-time path measure that are not present in the infinite-dimensional limit. These instabilities arise because of the difficulty of satisfying, in finite dimensions, the conditions imposed by Ito's lemma that was an essential ingredient in the derivation of the regularized continuous-time measure. As an important consequence of this analysis, we conclude that the most probable diffusion path is not a physical entity because the thermodynamic action is effectively flat and cannot be minimized.

  7. [Determination of trace and ultra-trace level bromate in water by large volume sample injection with enrichment column for on-line preconcentration coupled with ion chromatography].

    Science.gov (United States)

    Liu, Jing; He, Qingqing; Yang, Lili; Hu, Enyu; Wang, Meifei

    2015-10-01

    A method for the determination of trace and ultra-trace level bromate in water by ion chromatography with large volume sample injection for on-line preconcentration was established. A high capacity Dionex IonPac AG23 guard column was simply used as the enrichment column instead of the loop for the preconcentration of bromate. High purity KOH solution used as eluent for gradient elution was on-line produced by an eluent generator automatically. The results showed that a good linear relationship of bromate was exhibited in the range of 0.05-51.2 μg/L (r ≥ 0.999 5), and the method detection limit was 0.01 μg/L. Compared with conventional sample injection, the injection volume was up to 5 mL, and the enrichment factor of this method was about 240 times. This method was successfully applied for several real samples of pure water which were purchased in the supermarket, and the recoveries of bromate were between 90%-100% with the RSDs (n = 6) of 2.1%-6.4% at two spiked levels. This method without pretreatment is simple, and of high accuracy and precision. The preconcentration can be achieved by large volume sample injection. It is suitable for the analysis of trace and ultra-trace level bromate.

  8. Pelvic Radiotherapy versus Radical Prostatectomy with Limited Lymph Node Sampling for High-Grade Prostate Adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Christopher B. Baker

    2016-01-01

    Full Text Available Purpose. To compare oncologic outcomes for patients with Gleason score (GS ≥ 8 prostate adenocarcinoma treated with radical prostatectomy (RP versus external beam radiotherapy combined with androgen deprivation (RT + ADT. Methods. Between 2001 and 2014, 121 patients with GS ≥ 8 were treated at our institution via RT + ADT (n=71 or RP (n=50 with ≥ 1 year of biochemical follow-up. Endpoints included biochemical failure (BF, distant metastasis, and initiation of salvage ADT. Results. The RT + ADT group was older, had higher biopsy GS, and had greater risk of lymph node involvement. All other pretreatment characteristics were similar between groups. Mean number of lymph nodes (LNs sampled for patients undergoing RP was 8.2 (±6.18. Mean biochemical follow-up for all patients was 61 months. Five-year estimates of BF for the RT + ADT and RP groups were 7.2% versus 42.3%, (p<0.001. The RT + ADT group also had lower rates of distant metastasis (2% versus 7.8% and salvage ADT (8% versus 33.8%. Conclusion. In this analysis, RT + ADT was associated with improved biochemical and metastatic control when compared to RP with limited LN sampling. How RT + ADT compares with more aggressive lymphadenectomy, as is currently our institutional standard, remains an important unanswered question.

  9. The Large-Volume Limit of a Quantum Tetrahedron is a Quantum Harmonic Oscillator

    CERN Document Server

    Schliemann, John

    2013-01-01

    It is shown that the volume operator of a quantum tetrahedron is, in the sector of large eigenvalues, accurately described by a quantum harmonic oscillator. This result relies on the fact that (i) the volume operator couples only neighboring states of its standard basis, and (ii) its matrix elements show a unique maximum as a function of internal angular momentum quantum numbers. These quantum numbers, considered as a continuous variable, are the coordinate of the oscillator describing its quadratic potential, while the corresponding derivative defines a momentum operator. We also analyze the scaling properties of the oscillator parameters as a function of the size of the tetrahedron, and the role of different angular momentum coupling schemes.

  10. RESULTS FROM EPA FUNDED RESEARCH PROGRAMS ON THE IMPORTANCE OF PURGE VOLUME, SAMPLE VOLUME, SAMPLE FLOW RATE AND TEMPORAL VARIATIONS ON SOIL GAS CONCENTRATIONS

    Science.gov (United States)

    Two research studies funded and overseen by EPA have been conducted since October 2006 on soil gas sampling methods and variations in shallow soil gas concentrations with the purpose of improving our understanding of soil gas methods and data for vapor intrusion applications. Al...

  11. Gulf of Mexico continental slope study annual report, year 2. Volume 2. Primary volume. Interim report 1985-1986. [Sampling for hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1986-09-01

    This report, which was prepared in three volumes (Executive Summary, Primary Volume, and Appendix), details the findings of two years of sampling on the continental slope of the northern Gulf of Mexico at depths of 300-3000 m. Preliminary results from a third year of sampling are also presented. Physical and chemical measurements included: CTD casts at 35 stations; sediment characteristics, including hydrocarbons and bulk sediment parameters from 60 stations; tissue hydrocarbon levels of representative benthic organisms; and delta carbon-13 values from sediments and organisms, including comparison of areas of natural petroleum seepage to prevailing slope conditions. The biological oceanography section provides detailed enumeration of megafaunal specimens collected by trawling and of macro- and meiofaunal specimens collected with a 600 sq cm box core. Major megafaunal groups treated are Arthropoda, Echinodermata, and demersal fishes.

  12. Three-dimensional sensitivity distribution and sample volume of low-induction-number electromagnetic-induction instruments

    Science.gov (United States)

    Callegary, J.B.; Ferre, T. P. A.; Groom, R.W.

    2012-01-01

    There is an ongoing effort to improve the understanding of the correlation of soil properties with apparent soil electrical conductivity as measured by low-induction-number electromagnetic-induction (LIN FEM) instruments. At a minimum, the dimensions of LIN FEM instruments' sample volume, the spatial distribution of sensitivity within that volume, and implications for surveying and analyses must be clearly defined and discussed. Therefore, a series of numerical simulations was done in which a conductive perturbation was moved systematically through homogeneous soil to elucidate the three-dimensional sample volume of LIN FEM instruments. For a small perturbation with electrical conductivity similar to that of the soil, instrument response is a measure of local sensitivity (LS). Our results indicate that LS depends strongly on the orientation of the instrument's transmitter and receiver coils and includes regions of both positive and negative LS. Integration of the absolute value of LS from highest to lowest was used to contour cumulative sensitivity (CS). The 90% CS contour was used to define the sample volume. For both horizontal and vertical coplanar coil orientations, the longest dimension of the sample volume was at the surface along the main instrument axis with a length of about four times the intercoil spacing (s) with maximum thicknesses of about 1 and 0.3 s, respectively. The imaged distribution of spatial sensitivity within the sample volume is highly complex and should be considered in conjunction with the expected scale of heterogeneity before the use and interpretation of LIN FEM for mapping and profiling. ?? Soil Science Society of America.

  13. Main Trend Extraction Based on Irregular Sampling Estimation and Its Application in Storage Volume of Internet Data Center

    Science.gov (United States)

    Dou, Chao

    2016-01-01

    The storage volume of internet data center is one of the classical time series. It is very valuable to predict the storage volume of a data center for the business value. However, the storage volume series from a data center is always “dirty,” which contains the noise, missing data, and outliers, so it is necessary to extract the main trend of storage volume series for the future prediction processing. In this paper, we propose an irregular sampling estimation method to extract the main trend of the time series, in which the Kalman filter is used to remove the “dirty” data; then the cubic spline interpolation and average method are used to reconstruct the main trend. The developed method is applied in the storage volume series of internet data center. The experiment results show that the developed method can estimate the main trend of storage volume series accurately and make great contribution to predict the future volume value. 
 PMID:28090205

  14. Main Trend Extraction Based on Irregular Sampling Estimation and Its Application in Storage Volume of Internet Data Center

    Directory of Open Access Journals (Sweden)

    Beibei Miao

    2016-01-01

    Full Text Available The storage volume of internet data center is one of the classical time series. It is very valuable to predict the storage volume of a data center for the business value. However, the storage volume series from a data center is always “dirty,” which contains the noise, missing data, and outliers, so it is necessary to extract the main trend of storage volume series for the future prediction processing. In this paper, we propose an irregular sampling estimation method to extract the main trend of the time series, in which the Kalman filter is used to remove the “dirty” data; then the cubic spline interpolation and average method are used to reconstruct the main trend. The developed method is applied in the storage volume series of internet data center. The experiment results show that the developed method can estimate the main trend of storage volume series accurately and make great contribution to predict the future volume value.

  15. Detection of triazole deicing additives in soil samples from airports with low, mid, and large volume aircraft deicing activities.

    Science.gov (United States)

    McNeill, K S; Cancilla, D A

    2009-03-01

    Soil samples from three USA airports representing low, mid, and large volume users of aircraft deicing fluids (ADAFs) were analyzed by LC/MS/MS for the presence of triazoles, a class of corrosion inhibitors historically used in ADAFs. Triazoles, specifically the 4-methyl-1H-benzotriazole and the 5-methyl-1H-benzotriazole, were detected in a majority of samples and ranged from 2.35 to 424.19 microg/kg. Previous studies have focused primarily on ground and surface water impacts of larger volume ADAF users. The detection of triazoles in soils at low volume ADAF use airports suggests that deicing activities may have a broader environmental impact than previously considered.

  16. Limits of dose escalation in lung cancer: a dose-volume histogram analysis comparing coplanar and non-coplanar techniques

    Energy Technology Data Exchange (ETDEWEB)

    Derycke, S.; Van Duyse, B.; Schelfhout, J.; De Neve, W.

    1995-12-01

    To evaluate the feasibility of dose escalation in radiotherapy of inoperable lung cancer, a dose-volume histogram analysis was performed comparing standard coplanar (2D) with non-coplanar (3D) beam arrangements on a non-selected group of 20 patients planned by Sherouse`s GRATISTM 3D-planning system. Serial CT-scanning was performed and 2 Target Volumes (Tvs) were defined. Gross Tumor Volume (GTV) defined a high-dose Target Volume (TV-1). GTV plus location of node stations with > 10% probability of invasion (Minet et al.) defined an intermediate-dose Target Volume (TV-2). However, nodal regions which are incompatible with cure were excluded from TV-2. These are ATS-regions 1, 8, 9 and 14 all left and right as well as heterolateral regions. For 3D-planning, Beam`s Eye View selected (by an experienced planner) beam arrangements were optimised using Superdot, a method of target dose-gradient annihilation developed by Sherouse. A second 3D-planning was performed using 4 beam incidences with maximal angular separation. The linac`s isocenter for the optimal arrangement was located at the geometrical center of gravity of a tetraheder, the tetraheder`s comers being the consecutive positions of the virtual source. This ideal beam arrangement was approximated as close as possible, taking into account technical limitations (patient-couch-gantry collisions). Criteria for tolerance were met if no points inside the spinal cord exceeded 50 Gy and if at least 50% of the lung volume received less than 20Gy. If dose regions below 50 Gy were judged acceptable at TV-2, 2D- as well as 3D-plans allow safe escalation to 80 Gy at TV-1. When TV-2 needed to be encompassed by isodose surfaces exceeding 50Gy, 3D-plans were necessary to limit dose at the spinal cord below tolerance. For large TVs dose is limited by lung tolerance for 3D-plans. An analysis (including NTCP-TCP as cost functions) of rival 3D-plans is being performed.

  17. An integrated nano-scale approach to profile miRNAs in limited clinical samples

    Science.gov (United States)

    Seumois, Grégory; Vijayanand, Pandurangan; Eisley, Christopher J; Omran, Nada; Kalinke, Lukas; North, Mal; Ganesan, Asha P; Simpson, Laura J; Hunkapiller, Nathan; Moltzahn, Felix; Woodruff, Prescott G; Fahy, John V; Erle, David J; Djukanovic, Ratko; Blelloch, Robert; Ansel, K Mark

    2012-01-01

    Profiling miRNA expression in cells that directly contribute to human disease pathogenesis is likely to aid the discovery of novel drug targets and biomarkers. However, tissue heterogeneity and the limited amount of human diseased tissue available for research purposes present fundamental difficulties that often constrain the scope and potential of such studies. We established a flow cytometry-based method for isolating pure populations of pathogenic T cells from bronchial biopsy samples of asthma patients, and optimized a high-throughput nano-scale qRT-PCR method capable of accurately measuring 96 miRNAs in as little as 100 cells. Comparison of circulating and airway T cells from healthy and asthmatic subjects revealed asthma-associated and tissue-specific miRNA expression patterns. These results establish the feasibility and utility of investigating miRNA expression in small populations of cells involved in asthma pathogenesis, and set a precedent for application of our nano-scale approach in other human diseases. The microarray data from this study (Figure 7) has been submitted to the NCBI Gene Expression Omnibus (GEO; http://ncbi.nlm.nih.gov/geo) under accession no. GSE31030. PMID:23304658

  18. Improved method for collection of sputum for tuberculosis testing to ensure adequate sample volumes for molecular diagnostic testing.

    Science.gov (United States)

    Fisher, Mark; Dolby, Tania; Surtie, Shireen; Omar, Gaironesa; Hapeela, Nchimunya; Basu, Debby; DeWalt, Abby; Kelso, David; Nicol, Mark; McFall, Sally

    2017-04-01

    The quality and quantity of sputum collected has an important impact on the laboratory diagnosis of pulmonary TB. We conducted a pilot study to assess a new collection cups for the collection of sputum for the diagnosis of pulmonary tuberculosis. The pilot study utilized the standard collection cup in South Africa demonstrating a mean collection volume of 2.86±2.36SDml for 198 samples; 19% of the specimens contained 5ml. We designed and tested two novel sputum cups with a narrow bottom section and clear minimum and maximum markings to allow patients and clinicians to know whether sufficient sputum volume has been produced. The cups differed in their shape and manufacturing approach. The two options also support different mixing approaches being considered for a highly sensitive companion TB-screening assay being developed at Northwestern University (XtracTB assay). Sputum was collected from 102 patients at Nolungile Youth Centre, Khayelitsha, Cape Town, South Africa for a total of 204 samples. The mean volumes collected from the two cups were 2.70±0.88SDml and 2.88±0.89SDml. While the mean volumes of current and novel cups are similar, the volume ranges collected with the novel cups were narrower, and 98% of the specimen volumes were within the target range. Only 4 samples contained >5ml, but none were >6ml, and none of the specimens contained <1ml. The number of coughs that produced the samples, patient HIV and TB status plus qualitative descriptions of the sputum specimens were also evaluated.

  19. Finite volume treatment of pi pi scattering and limits to phase shifts extraction from lattice QCD

    CERN Document Server

    Albaladejo, M; Oset, E; Rios, G; Roca, L

    2012-01-01

    We study theoretically the effects of finite volume for pipi scattering in order to extract physical observables for infinite volume from lattice QCD. We compare three different approaches for pipi scattering (lowest order Bethe-Salpeter approach, N/D and inverse amplitude methods) with the aim to study the effects of the finite size of the box in the potential of the different theories, specially the left-hand cut contribution through loops in the crossed t,u-channels. We quantify the error made by neglecting these effects in usual extractions of physical observables from lattice QCD spectra. We conclude that for pipi phase-shifts in the scalar-isoscalar channel up to 800 MeV this effect is negligible for box sizes bigger than 2.5m_pi^-1 and of the order of 5% at around 1.5-2m_pi^-1. For isospin 2 the finite size effects can reach up to 10% for that energy. We also quantify the error made when using the standard Luscher method to extract physical observables from lattice QCD, which is widely used in the lite...

  20. SAMPL5: 3D-RISM partition coefficient calculations with partial molar volume corrections and solute conformational sampling

    Science.gov (United States)

    Luchko, Tyler; Blinov, Nikolay; Limon, Garrett C.; Joyce, Kevin P.; Kovalenko, Andriy

    2016-11-01

    Implicit solvent methods for classical molecular modeling are frequently used to provide fast, physics-based hydration free energies of macromolecules. Less commonly considered is the transferability of these methods to other solvents. The Statistical Assessment of Modeling of Proteins and Ligands 5 (SAMPL5) distribution coefficient dataset and the accompanying explicit solvent partition coefficient reference calculations provide a direct test of solvent model transferability. Here we use the 3D reference interaction site model (3D-RISM) statistical-mechanical solvation theory, with a well tested water model and a new united atom cyclohexane model, to calculate partition coefficients for the SAMPL5 dataset. The cyclohexane model performed well in training and testing (R=0.98 for amino acid neutral side chain analogues) but only if a parameterized solvation free energy correction was used. In contrast, the same protocol, using single solute conformations, performed poorly on the SAMPL5 dataset, obtaining R=0.73 compared to the reference partition coefficients, likely due to the much larger solute sizes. Including solute conformational sampling through molecular dynamics coupled with 3D-RISM (MD/3D-RISM) improved agreement with the reference calculation to R=0.93. Since our initial calculations only considered partition coefficients and not distribution coefficients, solute sampling provided little benefit comparing against experiment, where ionized and tautomer states are more important. Applying a simple pK_{ {a}} correction improved agreement with experiment from R=0.54 to R=0.66, despite a small number of outliers. Better agreement is possible by accounting for tautomers and improving the ionization correction.

  1. Large volume of water samples introduced in dispersive liquid-liquid microextraction for the determination of 15 triazole fungicides by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Nie, Jing; Chen, Fujiang; Song, Zhiyu; Sun, Caixia; Li, Zuguang; Liu, Wenhan; Lee, Mawrong

    2016-10-01

    A novel method of large volume of water samples directly introduced in dispersive liquid-liquid microextraction was developed, which is based on ultrasound/manual shaking-synergy-assisted emulsification and self-generating carbon dioxide gas (CO2) breaking down the emulsion for the determination of 15 triazole fungicides by gas chromatography-tandem mass spectrometry. This technique makes low-density extraction solvent toluene (180 μL) dissolve in 200 mL of samples containing 0.05 mol L(-1) of HCl and 5 % of NaCl (w/v) to form a well emulsion by synergy of ultrasound and manual shaking, and injects NaHCO3 solution (1.0 mol L(-1)) to generate CO2 achieving phase separation with the assistance of ultrasound. The entire process is accomplished within 8 min. The injection of NaHCO3 to generate CO2 achieves phase separation that breaks through the centrifugation limited large volume aqueous samples. In addition, the device could be easily cleaned, and this kind of vessel could be reconfigured for any volume of samples. Under optimal conditions, the low limits of detection ranging from 0.7 to 51.7 ng L(-1), wide linearity, and enrichment factors obtained were in the range 924-3669 for different triazole fungicides. Southern end of the Beijing-Hangzhou Grand Canal water (Hangzhou, China) was used to verify the applicability of the developed method. Graphical Abstract Flow chart of ultrasound/manual shaking-synergy-assisted emulsification and self-generating carbon dioxide gas breaking down the emulsion.

  2. Near-infrared diffuse reflectance spectroscopy with sample spots and chemometrics for fast determination of bovine serum albumin in micro-volume samples

    Institute of Scientific and Technical Information of China (English)

    Cai-Jing Cui; Wen-Sheng Cai; Xue-Guang Shao

    2013-01-01

    Near-infrared diffuse reflectance spectroscopy (NIRDRS) has attracted more and more attention in analyzing the components in samples with complex matrices.However,to apply this technique to micro-analysis,there are still some obstacles to overcome such as the low sensitivity and spectral overlapping associated with this approach.A method for fast determination of bovine serum albumin (BSA) in micro-volume samples was studied using NIRDRS with sample spots and chemometric techniques.10 μL of sample spotted on a filter paper substrate was used for the spectral measurements.Quantitative analysis was obtained by partial least squares (PLS) regression with signal processing and variable selection.The results show that the correlation coefficient (R) between the predicted and the reference concentration is 0.9897 and the recoveries are in the range of 87.4%-114.4% for the validation samples in the concentration range of 0.61-8.10 mg/mL.These results suggest that the method has the potential to quickly measure proteins in micro-volume solutions.

  3. Remedial investigation sampling and analysis plan for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Field Sampling Plan

    Energy Technology Data Exchange (ETDEWEB)

    Benioff, P.; Biang, R.; Dolak, D.; Dunn, C.; Martino, L.; Patton, T.; Wang, Y.; Yuen, C.

    1995-03-01

    The Environmental Management Division (EMD) of Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation and feasibility study (RI/FS) of the J-Field area at APG pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. J-Field is within the Edgewood Area of APG in Harford County, Maryland (Figure 1. 1). Since World War II activities in the Edgewood Area have included the development, manufacture, testing, and destruction of chemical agents and munitions. These materials were destroyed at J-Field by open burning and open detonation (OB/OD). Considerable archival information about J-Field exists as a result of efforts by APG staff to characterize the hazards associated with the site. Contamination of J-Field was first detected during an environmental survey of the Edgewood Area conducted in 1977 and 1978 by the US Army Toxic and Hazardous Materials Agency (USATHAMA) (predecessor to the US Army Environmental Center [AEC]). As part of a subsequent USATHAMA -environmental survey, 11 wells were installed and sampled at J-Field. Contamination at J-Field was also detected during a munitions disposal survey conducted by Princeton Aqua Science in 1983. The Princeton Aqua Science investigation involved the installation and sampling of nine wells and the collection and analysis of surficial and deep composite soil samples. In 1986, a Resource Conservation and Recovery Act (RCRA) permit (MD3-21-002-1355) requiring a basewide RCRA Facility Assessment (RFA) and a hydrogeologic assessment of J-Field was issued by the US Environmental Protection Agency (EPA). In 1987, the US Geological Survey (USGS) began a two-phased hydrogeologic assessment in data were collected to model, groundwater flow at J-Field. Soil gas investigations were conducted, several well clusters were installed, a groundwater flow model was developed, and groundwater and surface water monitoring programs were established that continue today.

  4. Rapid determination of benzene derivatives in water samples by trace volume solvent DLLME prior to GC-FID

    Energy Technology Data Exchange (ETDEWEB)

    Diao, Chun Peng; Wei, Chao Hai; Feng, Chun Hua [South China Univ. of Technology, Guangzhou Higher Education Mega Center (China). College of Environmental Science and Engineering; Guangdong Regular Higher Education Institutions, Guangzhou (China). Key Lab. of Environmental Protection and Eco-Remediation

    2012-05-15

    An inexpensive, simple and environmentally friendly method based on dispersive liquid liquid microextraction (DLLME) for rapid determination of benzene derivatives in water samples was proposed. A significant improvement of DLLME procedure was achieved. Trace volume ethyl acetate (60 {mu}L) was exploited as dispersion solvent instead of common ones such as methanol and acetone, the volume of which was more than 0.5 mL, and the organic solvent required in DLLME was reduced to a great extent. Only 83-{mu}L organic solvent was consumed in the whole analytic process and the preconcentration procedure was less than 10 min. The advantageous approach coupled with gas chromatograph-flame ionization detector was proposed for the rapid determination of benzene, toluene, ethylbenzene and xylene isomers in water samples. Results showed that the proposed approach was an efficient method for rapid determination of benzene derivatives in aqueous samples. (orig.)

  5. Optimizing human semen cryopreservation by reducing test vial volume and repetitive test vial sampling

    DEFF Research Database (Denmark)

    Jensen, Christian F S; Ohl, Dana A; Parker, Walter R

    2015-01-01

    OBJECTIVE: To investigate optimal test vial (TV) volume, utility and reliability of TVs, intermediate temperature exposure (-88°C to -93°C) before cryostorage, cryostorage in nitrogen vapor (VN2) and liquid nitrogen (LN2), and long-term stability of VN2 cryostorage of human semen. DESIGN: Prospec......OBJECTIVE: To investigate optimal test vial (TV) volume, utility and reliability of TVs, intermediate temperature exposure (-88°C to -93°C) before cryostorage, cryostorage in nitrogen vapor (VN2) and liquid nitrogen (LN2), and long-term stability of VN2 cryostorage of human semen. DESIGN...

  6. Scheduling sampling to maximize information about time dependence in experiments with limited resources

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Christiansen, Lasse Engbo

    2013-01-01

    Looking for periodicity in sampled data requires that periods (lags) of different length are represented in the sampling plan. We here present a method to assist in planning of temporal studies with sparse resources, which optimizes the number of observed time lags for a fixed amount of samples...... within a fixed time window given a maximum time lag of interest. The method can also optimize the temporal sampling specifically for situations where samples are at risk of being rescheduled due to otherwise unpredictable events such as weather, faulty equipment, etc. The method is based on the framework...

  7. The interplay of the sign problem and the infinite volume limit: gauge theories with a theta term

    CERN Document Server

    Cai, Yiming; Goldbloom-Helzner, Ari; McPeak, Brian

    2016-01-01

    QCD and related gauge theories have a sign problem when a $\\theta$-term is included; this complicates the extraction of physical information from Euclidean space calculations as one would do in lattice studies. The sign problem arises in this system because the partition function for configurations with fixed topological charge $Q$, $\\mathcal{Z}_Q$, are summed weighted by $\\exp(i Q \\theta)$ to obtain the partition function for fixed $\\theta$, $ \\mathcal{Z}(\\theta)$. The sign problem gets exponentially worse numerically as the space-time volume is increased. Here it is shown that apart from the practical numerical issues associated with large volumes, there are some interesting issues of principle. A key quantity is the energy density as a function of $\\theta$, $\\varepsilon(\\theta) = -\\log \\left( \\mathcal{Z}(\\theta) \\right )/V$. This is expected to be well defined in the large 4-volume limit. Similarly, one expects the energy density for a fixed topological density $\\tilde{\\varepsilon}(Q/V) = -\\log \\left(\\math...

  8. Development of a Solid Phase Extraction Method for Agricultural Pesticides in Large-Volume Water Samples

    Science.gov (United States)

    An analytical method using solid phase extraction (SPE) and analysis by gas chromatography/mass spectrometry (GC/MS) was developed for the trace determination of a variety of agricultural pesticides and selected transformation products in large-volume high-elevation lake water sa...

  9. Integrating Girl Child Issues into Population Education: Strategies and Sample Curriculum and Instructional Materials. Volume 2.

    Science.gov (United States)

    United Nations Educational, Scientific, and Cultural Organization, Bangkok (Thailand).

    One of the most important vehicles for promoting the concerns of the "girl child" and the elimination of gender bias is through education, and since programs in population education are being funded all over the world, population education is a suitable and effective medium for integrating messages on the girl child. This two-volume publication…

  10. Characterization of the intragranular water regime within subsurface sediments: Pore volume, surface area, and mass transfer limitations

    Science.gov (United States)

    Hay, Michael B.; Stoliker, Deborah L.; Davis, James A.; Zachara, John M.

    2011-10-01

    Although "intragranular" pore space within grain aggregates, grain fractures, and mineral surface coatings may contain a relatively small fraction of the total porosity within a porous medium, it often contains a significant fraction of the reactive surface area, and can thus strongly affect the transport of sorbing solutes. In this work, we demonstrate a batch experiment procedure using tritiated water as a high-resolution diffusive tracer to characterize the intragranular pore space. The method was tested using uranium-contaminated sediments from the vadose and capillary fringe zones beneath the former 300A process ponds at the Hanford site (Washington). Sediments were contacted with tracers in artificial groundwater, followed by a replacement of bulk solution with tracer-free groundwater and the monitoring of tracer release. From these data, intragranular pore volumes were calculated and mass transfer rates were quantified using a multirate first-order mass transfer model. Tritium-hydrogen exchange on surface hydroxyls was accounted for by conducting additional tracer experiments on sediment that was vacuum dried after reaction. The complementary ("wet" and "dry") techniques allowed for the simultaneous determination of intragranular porosity and surface area using tritium. The Hanford 300A samples exhibited intragranular pore volumes of ˜1% of the solid volume and intragranular surface areas of ˜20%-35% of the total surface area. Analogous experiments using bromide ion as a tracer yielded very different results, suggesting very little penetration of bromide into the intragranular porosity.

  11. Characterization of the intragranular water regime within subsurface sediments: pore volume, surface area, and mass transfer limitations

    Science.gov (United States)

    Hay, Michael B.; Stoliker, Deborah L.; Davis, James A.; Zachara, John M.

    2011-01-01

    Although "intragranular" pore space within grain aggregates, grain fractures, and mineral surface coatings may contain a relatively small fraction of the total porosity within a porous medium, it often contains a significant fraction of the reactive surface area, and can thus strongly affect the transport of sorbing solutes. In this work, we demonstrate a batch experiment procedure using tritiated water as a high-resolution diffusive tracer to characterize the intragranular pore space. The method was tested using uranium-contaminated sediments from the vadose and capillary fringe zones beneath the former 300A process ponds at the Hanford site (Washington). Sediments were contacted with tracers in artificial groundwater, followed by a replacement of bulk solution with tracer-free groundwater and the monitoring of tracer release. From these data, intragranular pore volumes were calculated and mass transfer rates were quantified using a multirate first-order mass transfer model. Tritium-hydrogen exchange on surface hydroxyls was accounted for by conducting additional tracer experiments on sediment that was vacuum dried after reaction. The complementary ("wet" and "dry") techniques allowed for the simultaneous determination of intragranular porosity and surface area using tritium. The Hanford 300A samples exhibited intragranular pore volumes of ~1% of the solid volume and intragranular surface areas of ~20%–35% of the total surface area. Analogous experiments using bromide ion as a tracer yielded very different results, suggesting very little penetration of bromide into the intragranular porosity.

  12. Space-time adaptive ADER discontinuous Galerkin finite element schemes with a posteriori sub-cell finite volume limiting

    CERN Document Server

    Zanotti, Olindo; Dumbser, Michael; Hidalgo, Arturo

    2015-01-01

    In this paper we present a novel arbitrary high order accurate discontinuous Galerkin (DG) finite element method on space-time adaptive Cartesian meshes (AMR) for hyperbolic conservation laws in multiple space dimensions, using a high order \\aposteriori sub-cell ADER-WENO finite volume \\emph{limiter}. Notoriously, the original DG method produces strong oscillations in the presence of discontinuous solutions and several types of limiters have been introduced over the years to cope with this problem. Following the innovative idea recently proposed in \\cite{Dumbser2014}, the discrete solution within the troubled cells is \\textit{recomputed} by scattering the DG polynomial at the previous time step onto a suitable number of sub-cells along each direction. Relying on the robustness of classical finite volume WENO schemes, the sub-cell averages are recomputed and then gathered back into the DG polynomials over the main grid. In this paper this approach is implemented for the first time within a space-time adaptive ...

  13. Limits on the storage of quantum information in a volume of space

    CERN Document Server

    Flammia, Steven T; Kastoryano, Michael J; Kim, Isaac H

    2016-01-01

    We study the fundamental limits on the reliable storage of quantum information in lattices of qubits by deriving tradeoff bounds for approximate quantum error correcting codes. We introduce a notion of local approximate correctability and code distance, and give a number of equivalent formulations thereof, generalizing various exact error-correction criteria. Our tradeoff bounds relate the number of physical qubits $n$, the number of encoded qubits $k$, the code distance $d$, the accuracy parameter $\\delta$ that quantifies how well the erasure channel can be reversed, and the locality parameter $\\ell$ that specifies the length scale at which the recovery operation can be done. In a regime where the recovery is successful to accuracy $\\epsilon$ that is exponentially small in $\\ell$, which is the case for perturbations of local commuting projector codes, our bound reads $kd^{\\frac{2}{D-1}} \\le O\\bigl(n (\\log n)^{\\frac{2D}{D-1}} \\bigr)$ for codes on $D$-dimensional lattices of Euclidean metric. We also find that...

  14. Limited interlaboratory comparison of Schmallenberg virus antibody detection in serum samples

    DEFF Research Database (Denmark)

    van der Poel, W. H. M.; Cay, B.; Zientara, S.;

    2014-01-01

    Eight veterinary institutes in seven different countries in Europe participated in a limited interlaboratory comparison trial to evaluate laboratory performances of Schmallenberg virus (SBV) antibody detection in serum. Seven different sheep sera and three different cattle sera were circulated, a...

  15. Limited interlaboratory comparison of Schmallenberg virus antibody detection in serum samples.

    NARCIS (Netherlands)

    Poel, van der W.H.M.; Cay, B.; Zientara, S.; Steinbach, F.; Valarcher, J.F.; Botner, A.; Mars, M.H.; Hakze-van der Honing, van der R.W.; Schirrmeier, H.; Beer, M.

    2014-01-01

    Eight veterinary institutes in seven different countries in Europe participated in a limited interlaboratory comparison trial to evaluate laboratory performances of Schmallenberg virus (SBV) antibody detection in serum. Seven different sheep sera and three different cattle sera were circulated, and

  16. Arbitrary-Lagrangian-Eulerian Discontinuous Galerkin schemes with a posteriori subcell finite volume limiting on moving unstructured meshes

    Science.gov (United States)

    Boscheri, Walter; Dumbser, Michael

    2017-10-01

    Lagrangian formulations that are based on a fixed computational grid and which instead evolve the mapping of the reference configuration to the current one. Our new Lagrangian-type DG scheme adopts the novel a posteriori sub-cell finite volume limiter method recently developed in [62] for fixed unstructured grids. In this approach, the validity of the candidate solution produced in each cell by an unlimited ADER-DG scheme is verified against a set of physical and numerical detection criteria, such as the positivity of pressure and density, the absence of floating point errors (NaN) and the satisfaction of a relaxed discrete maximum principle (DMP) in the sense of polynomials. Those cells which do not satisfy all of the above criteria are flagged as troubled cells and are recomputed at the aid of a more robust second order TVD finite volume scheme. To preserve the subcell resolution capability of the original DG scheme, the FV limiter is run on a sub-grid that is 2 N + 1 times finer compared to the mesh of the original unlimited DG scheme. The new subcell averages are then gathered back into a high order DG polynomial by a usual conservative finite volume reconstruction operator. The numerical convergence rates of the new ALE ADER-DG schemes are studied up to fourth order in space and time and several test problems are simulated in order to check the accuracy and the robustness of the proposed numerical method in the context of the Euler and Navier-Stokes equations for compressible gas dynamics, considering both inviscid and viscous fluids. Finally, an application inspired by Inertial Confinement Fusion (ICF) type flows is considered by solving the Euler equations and the PDE of viscous and resistive magnetohydrodynamics (VRMHD).

  17. Probabilistic Requirements (Partial) Verification Methods Best Practices Improvement. Variables Acceptance Sampling Calculators: Empirical Testing. Volume 2

    Science.gov (United States)

    Johnson, Kenneth L.; White, K. Preston, Jr.

    2012-01-01

    The NASA Engineering and Safety Center was requested to improve on the Best Practices document produced for the NESC assessment, Verification of Probabilistic Requirements for the Constellation Program, by giving a recommended procedure for using acceptance sampling by variables techniques as an alternative to the potentially resource-intensive acceptance sampling by attributes method given in the document. In this paper, the results of empirical tests intended to assess the accuracy of acceptance sampling plan calculators implemented for six variable distributions are presented.

  18. Airborne virus sampling - Efficiencies of samplers and their detection limits for infectious bursal disease virus (IBDV)

    NARCIS (Netherlands)

    Yang Zhao, Yang; Aarnink, A.J.A.; Wang, Wei; Fabri, T.; Groot Koerkamp, P.W.G.; Jong, de M.C.M.

    2014-01-01

    Introduction. The airborne transmission of infectious diseases in livestock production is increasingly receiving research attention. Reliable techniques of air sampling are crucial to underpin the findings of such studies. This study evaluated the physical and biological efficiencies and detection l

  19. Quantitative pH assessment of small-volume samples using a universal pH indicator.

    Science.gov (United States)

    Brown, Jeffrey D; Bell, Nathaniel; Li, Victoria; Cantrell, Kevin

    2014-10-01

    We developed a hue-based pH determination method to analyze digital images of samples in a 384-well plate after the addition of a universal pH indicator. The standard error of calibration for 69 pH standards was 0.078 pH units, and no sample gave an error greater than 0.23 units. We then used in-solution isoelectric focusing to determine the isoelectric point of Wnt3A protein in conditioned medium and after purification and applied the described method to assess the pH of these small-volume samples. End users may access our standard to assay the pH of their own samples with no additional calibration. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Recovery of Cryptosporidium oocysts from small and large volume water samples using a compressed foam filter system.

    Science.gov (United States)

    Sartory, D P; Parton, A; Parton, A C; Roberts, J; Bergmann, K

    1998-12-01

    A novel filter system comprising open cell reticulated foam rings compressed between retaining plates and fitted into a filtration housing was evaluated for the recovery of oocysts of Cryptosporidium from water. Mean recoveries of 90.2% from seeded small and large volume (100-2000 l) tap water samples, and 88.8% from 10-20 l river water samples, were achieved. Following a simple potassium citrate flotation concentrate clean-up procedure, mean recoveries were 56.7% for the tap water samples and 60.9% for river water samples. This represents a marked improvement in capture and recovery of Cryptosporidium oocysts from water compared with conventional polypropylene wound cartridge filters and membrane filters.

  1. Recovery efficiency and limit of detection of aerosolized Bacillus anthracis Sterne from environmental surface samples.

    Science.gov (United States)

    Estill, Cheryl Fairfield; Baron, Paul A; Beard, Jeremy K; Hein, Misty J; Larsen, Lloyd D; Rose, Laura; Schaefer, Frank W; Noble-Wang, Judith; Hodges, Lisa; Lindquist, H D Alan; Deye, Gregory J; Arduino, Matthew J

    2009-07-01

    After the 2001 anthrax incidents, surface sampling techniques for biological agents were found to be inadequately validated, especially at low surface loadings. We aerosolized Bacillus anthracis Sterne spores within a chamber to achieve very low surface loading (ca. 3, 30, and 200 CFU per 100 cm(2)). Steel and carpet coupons seeded in the chamber were sampled with swab (103 cm(2)) or wipe or vacuum (929 cm(2)) surface sampling methods and analyzed at three laboratories. Agar settle plates (60 cm(2)) were the reference for determining recovery efficiency (RE). The minimum estimated surface concentrations to achieve a 95% response rate based on probit regression were 190, 15, and 44 CFU/100 cm(2) for sampling steel surfaces and 40, 9.2, and 28 CFU/100 cm(2) for sampling carpet surfaces with swab, wipe, and vacuum methods, respectively; however, these results should be cautiously interpreted because of high observed variability. Mean REs at the highest surface loading were 5.0%, 18%, and 3.7% on steel and 12%, 23%, and 4.7% on carpet for the swab, wipe, and vacuum methods, respectively. Precision (coefficient of variation) was poor at the lower surface concentrations but improved with increasing surface concentration. The best precision was obtained with wipe samples on carpet, achieving 38% at the highest surface concentration. The wipe sampling method detected B. anthracis at lower estimated surface concentrations and had higher RE and better precision than the other methods. These results may guide investigators to more meaningfully conduct environmental sampling, quantify contamination levels, and conduct risk assessment for humans.

  2. Testing of high-volume sampler inlets for the sampling of atmospheric radionuclides.

    Science.gov (United States)

    Irshad, Hammad; Su, Wei-Chung; Cheng, Yung S; Medici, Fausto

    2006-09-01

    Sampling of air for radioactive particles is one of the most important techniques used to determine the nuclear debris from a nuclear weapon test in the Earth's atmosphere or those particles vented from underground or underwater tests. Massive-flow air samplers are used to sample air for any indication of radionuclides that are a signature of nuclear tests. The International Monitoring System of the Comprehensive Nuclear Test Ban Treaty Organization includes seismic, hydroacoustic, infrasound, and gaseous xenon isotopes sampling technologies, in addition to radionuclide sampling, to monitor for any violation of the treaty. Lovelace Respiratory Research Institute has developed a large wind tunnel to test the outdoor radionuclide samplers for the International Monitoring System. The inlets for these samplers are tested for their collection efficiencies for different particle sizes at various wind speeds. This paper describes the results from the testing of two radionuclide sampling units used in the International Monitoring System. The possible areas of depositional wall losses are identified and the losses in these areas are determined. Sampling inlet type 1 was tested at 2.2 m s wind speed for 5, 10, and 20-microm aerodynamic diameter particles. The global collection efficiency was about 87.6% for 10-microm particles for sampling inlet type 1. Sampling inlet type 2 was tested for three wind speeds at 0.56, 2.2, and 6.6 m s for 5, 10, and 20-microm aerodynamic diameter particles in two different configurations (sampling head lowered and raised). The global collection efficiencies for these configurations for 10-microm particles at 2.2 m s wind speed were 77.4% and 82.5%, respectively. The sampling flow rate was 600 m h for both sampling inlets.

  3. SyPRID sampler: A large-volume, high-resolution, autonomous, deep-ocean precision plankton sampling system

    Science.gov (United States)

    Billings, Andrew; Kaiser, Carl; Young, Craig M.; Hiebert, Laurel S.; Cole, Eli; Wagner, Jamie K. S.; Van Dover, Cindy Lee

    2017-03-01

    The current standard for large-volume (thousands of cubic meters) zooplankton sampling in the deep sea is the MOCNESS, a system of multiple opening-closing nets, typically lowered to within 50 m of the seabed and towed obliquely to the surface to obtain low-spatial-resolution samples that integrate across 10 s of meters of water depth. The SyPRID (Sentry Precision Robotic Impeller Driven) sampler is an innovative, deep-rated (6000 m) plankton sampler that partners with the Sentry Autonomous Underwater Vehicle (AUV) to obtain paired, large-volume plankton samples at specified depths and survey lines to within 1.5 m of the seabed and with simultaneous collection of sensor data. SyPRID uses a perforated Ultra-High-Molecular-Weight (UHMW) plastic tube to support a fine mesh net within an outer carbon composite tube (tube-within-a-tube design), with an axial flow pump located aft of the capture filter. The pump facilitates flow through the system and reduces or possibly eliminates the bow wave at the mouth opening. The cod end, a hollow truncated cone, is also made of UHMW plastic and includes a collection volume designed to provide an area where zooplankton can collect, out of the high flow region. SyPRID attaches as a saddle-pack to the Sentry vehicle. Sentry itself is configured with a flight control system that enables autonomous survey paths to low altitudes. In its verification deployment at the Blake Ridge Seep (2160 m) on the US Atlantic Margin, SyPRID was operated for 6 h at an altitude of 5 m. It recovered plankton samples, including delicate living larvae, from the near-bottom stratum that is seldom sampled by a typical MOCNESS tow. The prototype SyPRID and its next generations will enable studies of plankton or other particulate distributions associated with localized physico-chemical strata in the water column or above patchy habitats on the seafloor.

  4. Selectivity and limitations of carbon sorption tubes for capturing siloxanes in biogas during field sampling.

    Science.gov (United States)

    Tansel, Berrin; Surita, Sharon C

    2016-06-01

    Siloxane levels in biogas can jeopardize the warranties of the engines used at the biogas to energy facilities. The chemical structure of siloxanes consists of silicon and oxygen atoms, alternating in position, with hydrocarbon groups attached to the silicon side chain. Siloxanes can be either in cyclic (D) or linear (L) configuration and referred with a letter corresponding to their structure followed by a number corresponding to the number of silicon atoms present. When siloxanes are burned, the hydrocarbon fraction is lost and silicon is converted to silicates. The purpose of this study was to evaluate the adequacy of activated carbon gas samplers for quantitative analysis of siloxanes in biogas samples. Biogas samples were collected from a landfill and an anaerobic digester using multiple carbon sorbent tubes assembled in series. One set of samples was collected for 30min (sampling 6-L gas), and the second set was collected for 60min (sampling 12-L gas). Carbon particles were thermally desorbed and analyzed by Gas Chromatography Mass Spectrometry (GC/MS). The results showed that biogas sampling using a single tube would not adequately capture octamethyltrisiloxane (L3), hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6). Even with 4 tubes were used in series, D5 was not captured effectively. The single sorbent tube sampling method was adequate only for capturing trimethylsilanol (TMS) and hexamethyldisiloxane (L2). Affinity of siloxanes for activated carbon decreased with increasing molecular weight. Using multiple carbon sorbent tubes in series can be an appropriate method for developing a standard procedure for determining siloxane levels for low molecular weight siloxanes (up to D3). Appropriate quality assurance and quality control procedures should be developed for adequately quantifying the levels of the higher molecular weight siloxanes in biogas with sorbent tubes

  5. Effect of the 16-hour work limit on general surgery intern operative case volume: a multi-institutional study.

    Science.gov (United States)

    Schwartz, Samuel I; Galante, Joseph; Kaji, Amy; Dolich, Matthew; Easter, David; Melcher, Marc L; Patel, Kevin; Reeves, Mark E; Salim, Ali; Senagore, Anthony J; Takanishi, Danny M; de Virgilio, Christian

    2013-09-01

    The 80-hour work-week limit for all residents was instituted in 2003 and studies looking at its effect have been mixed. Since the advent of the 16-hour mandate for postgraduate year 1 residents in July 2011, no data have been published regarding the effect of this additional work-hour restriction. To determine whether the 16-hour intern work limit, implemented in July 2011, has adversely affected operative experience. A retrospective review of categorical postgraduate year 1 Accreditation Council for Graduate Medical Education case logs from the intern class (N = 52) (with 16-hour work limit) compared with the 4 preceding years (2007-2010; N = 197) (without 16-hour work limit). A total of 249 categorical general surgery interns from 10 general surgery residency programs in the western United States were included. Total, major, first-assistant, and defined-category case totals. As compared with the preceding 4 years, the 2011-2012 interns recorded a 25.8% decrease in total operative cases (65.9 vs 88.8, P = .005), a 31.8% decrease in major cases (54.9 vs 80.5, P intern era, whereas there was no decrease in trauma, vascular, alimentary, endoscopy, liver, and pancreas cases. The 16-hour work limit for interns, implemented in July 2011, is associated with a significant decrease in categorical intern operative experience. If the 16-hour shift were to be extended to all postgraduate year levels, one can anticipate that additional years of training will be needed to maintain the same operative volume.

  6. SHANNON SAMPLING AND ESTIMATION OF BAND-LIMITED FUNCTIONS IN THE SEVERAL COMPLEX VARIABLES SETTING

    Institute of Scientific and Technical Information of China (English)

    Kou Kit-Ian; Qian Tao

    2005-01-01

    In this work the authors develop the n-dimensional sinc function theory in the several complex variables setting. In terms of the corresponding Paley-Wiener theorem the exact sinc interpolation and quadrature are established. Exponential convergence rate of the error estimates for band-limited functions in n-dimensional strips are obtained.

  7. Limitations and potential of spectral subtractions in fourier-transform infrared (FTIR) spectroscopy of soil samples

    Science.gov (United States)

    Soil science research is increasingly applying Fourier transform infrared (FTIR) spectroscopy for analysis of soil organic matter (SOM). However, the compositional complexity of soils and the dominance of the mineral component can limit spectroscopic resolution of SOM and other minor components. The...

  8. [Metastatic characteristics of lymph node in supraclavicular zone and radiotherapy target volume for limited-stage small cell lung cancer].

    Science.gov (United States)

    Feng, Zhen-xing; Zhao, Lu-jun; Guan, Yong; Sun, Yao; Ji, Kai; Wang, Ping

    2013-05-21

    To explore the reasonable radiotherapy range by analyzing the characteristics of supraclavicular lymph node metastasis in limited-stage small cell lung cancer (LS-SCLC). From January 2005 to December 2011, patients of LS-SCLC were reviewed. Supraclavicular zone was further divided into five subgroups including para-recurrent laryngeal nerve (region I and region II ), para-internal jugular vein (region III ), supraclavicular region (region IV), as well as the other regions except for the mentioned above (region V). The characteristics of the lymph nodes in each region were analyzed. The supraclavicular lymph node metastasis was found in 60 patients, with a positive rate of 34.5%. In multivariate Logistic regression analysis,intra-thoracic lymph node metastasis in the lymph node stations of level 2 and 3 were found to be the risk factors of supraclavicular lymph node metastasis (P = 0.006,P = 0.000). Our data suggests that the frequencies of metastasis in region I and III were much higher than those in the other areas.Among the sixty patients with supraclavicular lymph node metastasis, 95.0% were found at region I or III while the incidence of skip metastasis was only 5.0%. It is advisable to contain the bilateral supraclavicular nodes in patients with mediastinal lymph nodes metastasis to the level 2 or 3 for elective radiation target volume.The clinical target volume (CTV) exterior margin containing the outer margin of internal jugular vein may be suitable.

  9. Nuclear waste calorimeter for very large drums with 385 litres sample volume

    Energy Technology Data Exchange (ETDEWEB)

    Jossens, G.; Mathonat, C. [SETARAM Instrumentation, Caluire (France); Bachelet, F. [CEA Valduc, Is sur Tille (France)

    2015-03-15

    Calorimetry is a very precise and well adapted tool for the classification of drums containing nuclear waste material depending on their level of activities (low, medium, high). A new calorimeter has been developed by SETARAM Instrumentation and the CEA Valduc in France. This new calorimeter is designed for drums having a volume bigger than 100 liters. It guarantees high operator safety by optimizing drum handling and air circulation for cooling, and optimized software for direct measurement of the quantity of nuclear material. The LVC1380 calorimeter makes it possible to work over the range 10 to 3000 mW, which corresponds to approximately 0.03 to 10 g of tritium or 3 to 955 g of {sup 241}Pu in a volume up to 385 liters. This calorimeter is based on the heat flow measurement using Peltier elements which surround the drum in the 3 dimensions and therefore measure all the heat coming from the radioactive stuff whatever its position inside the drum. Calorimeter's insulating layers constitute a thermal barrier designed to filter disturbances until they represent less than 0.001 Celsius degrees and to eliminate long term disturbances associated, for example, with laboratory temperature variations between day and night. A calibration device based on Joule effect has also been designed. Measurement time has been optimized but remains long compared with other methods of measurement such as gamma spectrometry but its main asset is to have a good accuracy for low level activities.

  10. On-chip polarimetry for high-throughput screening of nanoliter and smaller sample volumes

    Science.gov (United States)

    Bornhop, Darryl J. (Inventor); Dotson, Stephen (Inventor); Bachmann, Brian O. (Inventor)

    2012-01-01

    A polarimetry technique for measuring optical activity that is particularly suited for high throughput screening employs a chip or substrate (22) having one or more microfluidic channels (26) formed therein. A polarized laser beam (14) is directed onto optically active samples that are disposed in the channels. The incident laser beam interacts with the optically active molecules in the sample, which slightly alter the polarization of the laser beam as it passes multiple times through the sample. Interference fringe patterns (28) are generated by the interaction of the laser beam with the sample and the channel walls. A photodetector (34) is positioned to receive the interference fringe patterns and generate an output signal that is input to a computer or other analyzer (38) for analyzing the signal and determining the rotation of plane polarized light by optically active material in the channel from polarization rotation calculations.

  11. Limited sampling hampers “big data” estimation of species richness in a tropical biodiversity hotspot

    DEFF Research Database (Denmark)

    Engemann, Kristine; Enquist, Brian J.; Sandel, Brody Steven

    2015-01-01

    Macro-scale species richness studies often use museum specimens as their main source of information. However, such datasets are often strongly biased due to variation in sampling effort in space and time. These biases may strongly affect diversity estimates and may, thereby, obstruct solid infere...

  12. Limit theory for the sample autocorrelations and extremes of a GARCH (1,1) process

    NARCIS (Netherlands)

    Mikosch, T; Starica, C

    2000-01-01

    The asymptotic theory for the sample autocorrelations and extremes of a GARCH(I, 1) process is provided. Special attention is given to the case when the sum of the ARCH and GARCH parameters is close to 1, that is, when one is close to an infinite Variance marginal distribution. This situation has be

  13. Immune privilege of the CNS is not the consequence of limited antigen sampling

    Science.gov (United States)

    Harris, Melissa G.; Hulseberg, Paul; Ling, Changying; Karman, Jozsef; Clarkson, Benjamin D.; Harding, Jeffrey S.; Zhang, Mengxue; Sandor, Adam; Christensen, Kelsey; Nagy, Andras; Sandor, Matyas; Fabry, Zsuzsanna

    2014-03-01

    Central nervous system (CNS) immune privilege is complex, and it is still not understood how CNS antigens are sampled by the peripheral immune system under steady state conditions. To compare antigen sampling from immune-privileged or nonprivileged tissues, we created transgenic mice with oligodendrocyte or gut epithelial cell expression of an EGFP-tagged fusion protein containing ovalbumin (OVA) antigenic peptides and tested peripheral anti-OVA peptide-specific sentinel OT-I and OT-II T cell activation. We report that oligodendrocyte or gut antigens are sampled similarly, as determined by comparable levels of OT-I T cell activation. However, activated T cells do not access the CNS under steady state conditions. These data show that afferent immunity is normally intact as there is no barrier at the antigen sampling level, but that efferent immunity is restricted. To understand how this one-sided surveillance contributes to CNS immune privilege will help us define mechanisms of CNS autoimmune disease initiation.

  14. Adapting chain referral methods to sample new migrants: Possibilities and limitations

    Directory of Open Access Journals (Sweden)

    Lucinda Platt

    2015-09-01

    Full Text Available Background: Demographic research on migration requires representative samples of migrant populations. Yet recent immigrants, who are particularly informative about current migrant flows, are difficult to capture even in specialist surveys. Respondent-driven sampling (RDS, a chain referral sampling and analysis technique, potentially offers the opportunity to achieve population-level inference of recently arrived migrant populations. Objective: We evaluate the attempt to use RDS to sample two groups of migrants, from Pakistan and Poland, who had arrived in the UK within the previous 18 months, and we present an alternative approach adapted to recent migrants. Methods: We discuss how connectedness, privacy, clustering, and motivation are expected to differ among recently arrived migrants, compared to typical applications of RDS. We develop a researcher-led chain referral approach, and compare success in recruitment and indicators of representativeness to standard RDS recruitment. Results: Our researcher-led approach led to higher rates of chain-referral, and enabled us to reach population members with smaller network sizes. The researcher-led approach resulted in similar recruiter-recruit transition probabilities to traditional RDS across many demographic and social characteristics. However, we did not succeed in building up long referral chains, largely due to the lack of connectedness of our target populations and some reluctance to refer. There were some differences between the two migrant groups, with less mobile and less hidden Pakistani men producing longer referral chains. Conclusions: Chain referral is difficult to implement for sampling newly arrived migrants. However, our researcher-led adaptation shows promise for less hidden and more stable recent immigrant populations. Contribution: The paper offers an evaluation of RDS for surveying recent immigrants and an adaptation that may be effective under certain conditions.

  15. MCNP ESTIMATE OF THE SAMPLED VOLUME IN A NON-DESTRUCTIVE IN SITU SOIL CARBON ANALYSIS.

    Energy Technology Data Exchange (ETDEWEB)

    WIELOPOLSKI, L.; DIOSZEGI, I.; MITRA, S.

    2004-05-03

    Global warming, promoted by anthropogenic CO{sub 2} emission into the atmosphere, is partially mitigated by the photosynthesis processes of the terrestrial echo systems that act as atmospheric CO{sub 2} scrubbers and sequester carbon in soil. Switching from till to no till soils management practices in agriculture further augments this process. Carbon sequestration is also advanced by putting forward a carbon ''credit'' system whereby these can be traded between CO{sub 2} producers and sequesters. Implementation of carbon ''credit'' trade will be further promulgated by recent development of a non-destructive in situ carbon monitoring system based on inelastic neutron scattering (INS). Volumes and depth distributions defined by the 0.1, 1.0, 10, 50, and 90 percent neutron isofluxes, from a point source located at either 5 or 30 cm above the surface, were estimated using Monte Carlo calculations.

  16. Density-viscosity product of small-volume ionic liquid samples using quartz crystal impedance analysis.

    Science.gov (United States)

    McHale, Glen; Hardacre, Chris; Ge, Rile; Doy, Nicola; Allen, Ray W K; MacInnes, Jordan M; Bown, Mark R; Newton, Michael I

    2008-08-01

    Quartz crystal impedance analysis has been developed as a technique to assess whether room-temperature ionic liquids are Newtonian fluids and as a small-volume method for determining the values of their viscosity-density product, rho eta. Changes in the impedance spectrum of a 5-MHz fundamental frequency quartz crystal induced by a water-miscible room-temperature ionic liquid, 1-butyl-3-methylimiclazolium trifluoromethylsulfonate ([C4mim][OTf]), were measured. From coupled frequency shift and bandwidth changes as the concentration was varied from 0 to 100% ionic liquid, it was determined that this liquid provided a Newtonian response. A second water-immiscible ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C4mim][NTf2], with concentration varied using methanol, was tested and also found to provide a Newtonian response. In both cases, the values of the square root of the viscosity-density product deduced from the small-volume quartz crystal technique were consistent with those measured using a viscometer and density meter. The third harmonic of the crystal was found to provide the closest agreement between the two measurement methods; the pure ionic liquids had the largest difference of approximately 10%. In addition, 18 pure ionic liquids were tested, and for 11 of these, good-quality frequency shift and bandwidth data were obtained; these 12 all had a Newtonian response. The frequency shift of the third harmonic was found to vary linearly with square root of viscosity-density product of the pure ionic liquids up to a value of square root(rho eta) approximately 18 kg m(-2) s(-1/2), but with a slope 10% smaller than that predicted by the Kanazawa and Gordon equation. It is envisaged that the quartz crystal technique could be used in a high-throughput microfluidic system for characterizing ionic liquids.

  17. Evaluation of 5-FU pharmacokinetics in cancer patients with DPD deficiency using a Bayesian limited sampling strategy

    NARCIS (Netherlands)

    Van Kuilenburg, A.; Hausler, P.; Schalhorn, A.; Tanck, M.; Proost, J.H.; Terborg, C.; Behnke, D.; Schwabe, W.; Jabschinsky, K.; Maring, J.G.

    2011-01-01

    Aims: Dihydropyrimidine dehydrogenase (DPD) is the initial enzyme in the catabolism of 5-fluorouracil (5FU) and DPD deficiency is an important pharmacogenetic syndrome. The main purpose of this study was to develop a limited sampling strategy to evaluate the pharmacokinetics of 5FU and to detect dec

  18. Validation of limited sampling models (LSM) for estimating AUC in therapeutic drug monitoring - is a separate validation group required?

    NARCIS (Netherlands)

    Proost, J. H.

    2007-01-01

    Objective: Limited sampling models (LSM) for estimating AUC in therapeutic drug monitoring are usually validated in a separate group of patients, according to published guidelines. The aim of this study is to evaluate the validation of LSM by comparing independent validation with cross-validation us

  19. Measurement facilities and accuracy limits of sampling digital interferometers. Meresi lehetoesegek es hibaanalizis digitalis mintavetelezoe interferometeren

    Energy Technology Data Exchange (ETDEWEB)

    Czitrovszky, A.; Jani, P.; Szoter, L.

    1990-12-15

    We discuss the measurement facilities of a recently development sampling digital interferometer for machine tool testing. As opposed to conventional interferometers the present device provides possibilities for the digital storage up to 4 kHz of the complete information of the motion so that displacement, velocity, acceleration and power density spectrum measurement can be performed. An estimation is given for the truncation, round-off, jitter and frequency-aliasing sources of error of the reconstructed motion parameters. On the basis of the Shannon sampling theory optimal conditions of measurement parameters are defined for the case when the accuracy of the reconstructed part of motion and vibration is equal to the resolution of the conventional interferometer. 7 refs., 3 figs., 1 tab.

  20. Nonparametric feature extraction for classification of hyperspectral images with limited training samples

    Science.gov (United States)

    Kianisarkaleh, Azadeh; Ghassemian, Hassan

    2016-09-01

    Feature extraction plays a crucial role in improvement of hyperspectral images classification. Nonparametric feature extraction methods show better performance compared to parametric ones when distribution of classes is non normal-like. Moreover, they can extract more features than parametric methods do. In this paper, a new nonparametric linear feature extraction method is introduced for classification of hyperspectral images. The proposed method has no free parameter and its novelty can be discussed in two parts. First, neighbor samples are specified by using Parzen window idea for determining local mean. Second, two new weighting functions are used. Samples close to class boundaries will have more weight in the between-class scatter matrix formation and samples close to class mean will have more weight in the within-class scatter matrix formation. The experimental results on three real hyperspectral data sets, Indian Pines, Salinas and Pavia University, demonstrate that the proposed method has better performance in comparison with some other nonparametric and parametric feature extraction methods.

  1. On Almost Sure Max-limit Theorems of Complete and Incomplete Samples from Stationary Sequences

    Institute of Scientific and Technical Information of China (English)

    Bin TONG; Zuo Xiang PENG

    2011-01-01

    Let Mn denote the partial maximum of a strictly stationary sequence (Xn). Suppose that some of the random variables of (Xn) can be observed and let (M~)n stand for the maximum of observed random variables from the set {Xi,..., Xn}. In this paper, the almost sure limit theorems related to random vector ((M~),Mn) are considered in terms of i.i.d. case. The related results are also extended to weakly dependent stationary Gaussian sequence as its covariance function satisfies some regular conditions.

  2. In situ sampling of small volumes of soil solution using modified micro-suction cups

    NARCIS (Netherlands)

    Shen, Jianbo; Hoffland, E.

    2007-01-01

    Two modified designs of micro-pore-water samplers were tested for their capacity to collect unbiased soil solution samples containing zinc and citrate. The samplers had either ceramic or polyethersulfone (PES) suction cups. Laboratory tests of the micro-samplers were conducted using (a) standard sol

  3. Scheduling Algorithm for Mission Planning and Logistics Evaluation (SAMPLE). Volume 2: Mission payloads subsystem description

    Science.gov (United States)

    Dupnick, E.; Wiggins, D.

    1980-01-01

    The scheduling algorithm for mission planning and logistics evaluation (SAMPLE) is presented. Two major subsystems are included: The mission payloads program; and the set covering program. Formats and parameter definitions for the payload data set (payload model), feasible combination file, and traffic model are documented.

  4. Sampling of high amounts of bioaerosols using a high-volume electrostatic field sampler

    DEFF Research Database (Denmark)

    Madsen, A. M.; Sharma, Anoop Kumar

    2008-01-01

    by the electrostatic field sampler and 11.8 mg m(-3) when measured by the GSP inhalable dust sampler. The quantity (amount per mg dust) of total fungi, Aspergillus fumigatus, total bacteria, endotoxin and mesophilic actinomycetes sampled by the electrostatic field samplers and the Gravikon samplers varied within...

  5. The Keck+Magellan Survey for Lyman Limit Absorption III: Sample Definition and Column Density Measurements

    CERN Document Server

    Prochaska, J Xavier; Fumagalli, Michele; Bernstein, Rebecca A; Burles, Scott M

    2015-01-01

    We present an absorption-line survey of optically thick gas clouds -- Lyman Limit Systems (LLSs) -- observed at high dispersion with spectrometers on the Keck and Magellan telescopes. We measure column densities of neutral hydrogen NHI and associated metal-line transitions for 157 LLSs at z=1.76-4.39 restricted to 10^17.3 < NHI < 10^20.3. An empirical analysis of ionic ratios indicates an increasing ionization state of the gas with decreasing NHI and that the majority of LLSs are highly ionized, confirming previous expectations. The Si^+/H^0 ratio spans nearly four orders-of-magnitude, implying a large dispersion in the gas metallicity. Fewer than 5% of these LLSs have no positive detection of a metal transition; by z~3, nearly all gas that is dense enough to exhibit a very high Lyman limit opacity has previously been polluted by heavy elements. We add new measurements to the small subset of LLS (~5-10) that may have super-solar abundances. High Si^+/Fe^+ ratios suggest an alpha-enhanced medium whereas ...

  6. Sampling international migrants with origin-based snowballing method:: New evidence on biases and limitations.

    Directory of Open Access Journals (Sweden)

    Cris Beauchemin

    2011-07-01

    Full Text Available This paper provides a methodological assessment of the advantages and drawbacks of the origin-based snowballing technique as a reliable method to construct representative samples of international migrants in destination areas. Using data from the MAFE-Senegal Project, our results indicate that this is a very risky method in terms of quantitative success. Besides, it implies some clear selection biases: it over-represents migrants more strongly connected to their home country, and it tends to overestimate both poverty in households at origin and the influence of previous migration experiences of social networks on individuals' out-migration.

  7. Replica-exchange Wang Landau sampling: pushing the limits of Monte Carlo simulations in materials sciences

    Energy Technology Data Exchange (ETDEWEB)

    Perera, Meewanage Dilina N [ORNL; Li, Ying Wai [ORNL; Eisenbach, Markus [ORNL; Vogel, Thomas [Los Alamos National Laboratory (LANL); Landau, David P [University of Georgia, Athens

    2015-01-01

    We describe the study of thermodynamics of materials using replica-exchange Wang Landau (REWL) sampling, a generic framework for massively parallel implementations of the Wang Landau Monte Carlo method. To evaluate the performance and scalability of the method, we investigate the magnetic phase transition in body-centered cubic (bcc) iron using the classical Heisenberg model parameterized with first principles calculations. We demonstrate that our framework leads to a significant speedup without compromising the accuracy and precision and facilitates the study of much larger systems than is possible with its serial counterpart.

  8. RNA Profiling for Biomarker Discovery: Practical Considerations for Limiting Sample Sizes

    Directory of Open Access Journals (Sweden)

    Danny J. Kelly

    2005-01-01

    Full Text Available We have compared microarray data generated on Affymetrix™ chips from standard (8 micrograms or low (100 nanograms amounts of total RNA. We evaluated the gene signals and gene fold-change estimates obtained from the two methods and validated a subset of the results by real time, polymerase chain reaction assays. The correlation of low RNA derived gene signals to gene signals obtained from standard RNA was poor for less to moderately abundant genes. Genes with high abundance showed better correlation in signals between the two methods. The signal correlation between the low RNA and standard RNA methods was improved by including a reference sample in the microarray analysis. In contrast, the fold-change estimates for genes were better correlated between the two methods regardless of the magnitude of gene signals. A reference sample based method is suggested for studies that would end up comparing gene signal data from a combination of low and standard RNA templates; no such referencing appears to be necessary when comparing fold-changes of gene expression between standard and low template reactions.

  9. High-resolution liquid- and solid-state nuclear magnetic resonance of nanoliter sample volumes using microcoil detectors

    NARCIS (Netherlands)

    Kentgens, A.P.M.; Bart, J.; Bentum, van P.J.M.; Brinkmann, A.; Eck, van E.R.H.; Gardeniers, J.G.E.; Janssen, J.W.G.; Knijn, P.J.; Vasa, S.; Verkuijlen, M.H.W.

    2008-01-01

    The predominant means to detect nuclear magnetic resonance(NMR) is to monitor the voltage induced in a radiofrequency coil by the precessing magnetization. To address the sensitivity of NMR for mass-limited samples it is worthwhile to miniaturize this detector coil. Although making smaller coils see

  10. A propidium monoazide-quantitative PCR method for the detection and quantification of viable Enterococcus faecalis in large-volume samples of marine waters.

    Science.gov (United States)

    Salam, Khaled W; El-Fadel, Mutasem; Barbour, Elie K; Saikaly, Pascal E

    2014-10-01

    The development of rapid detection assays of cell viability is essential for monitoring the microbiological quality of water systems. Coupling propidium monoazide with quantitative PCR (PMA-qPCR) has been successfully applied in different studies for the detection and quantification of viable cells in small-volume samples (0.25-1.00 mL), but it has not been evaluated sufficiently in marine environments or in large-volume samples. In this study, we successfully integrated blue light-emitting diodes for photoactivating PMA and membrane filtration into the PMA-qPCR assay for the rapid detection and quantification of viable Enterococcus faecalis cells in 10-mL samples of marine waters. The assay was optimized in phosphate-buffered saline and seawater, reducing the qPCR signal of heat-killed E. faecalis cells by 4 log10 and 3 log10 units, respectively. Results suggest that high total dissolved solid concentration (32 g/L) in seawater can reduce PMA activity. Optimal PMA-qPCR standard curves with a 6-log dynamic range and detection limit of 10(2) cells/mL were generated for quantifying viable E. faecalis cells in marine waters. The developed assay was compared with the standard membrane filter (MF) method by quantifying viable E. faecalis cells in seawater samples exposed to solar radiation. The results of the developed PMA-qPCR assay did not match that of the standard MF method. This difference in the results reflects the different physiological states of E. faecalis cells in seawater. In conclusion, the developed assay is a rapid (∼5 h) method for the quantification of viable E. faecalis cells in marine recreational waters, which should be further improved and tested in different seawater settings.

  11. A propidium monoazide–quantitative PCR method for the detection and quantification of viable Enterococcus faecalis in large-volume samples of marine waters

    KAUST Repository

    Salam, Khaled W.

    2014-08-23

    The development of rapid detection assays of cell viability is essential for monitoring the microbiological quality of water systems. Coupling propidium monoazide with quantitative PCR (PMA-qPCR) has been successfully applied in different studies for the detection and quantification of viable cells in small-volume samples (0.25-1.00 mL), but it has not been evaluated sufficiently in marine environments or in large-volume samples. In this study, we successfully integrated blue light-emitting diodes for photoactivating PMA and membrane filtration into the PMA-qPCR assay for the rapid detection and quantification of viable Enterococcus faecalis cells in 10-mL samples of marine waters. The assay was optimized in phosphate-buffered saline and seawater, reducing the qPCR signal of heat-killed E. faecalis cells by 4 log10 and 3 log10 units, respectively. Results suggest that high total dissolved solid concentration (32 g/L) in seawater can reduce PMA activity. Optimal PMA-qPCR standard curves with a 6-log dynamic range and detection limit of 102 cells/mL were generated for quantifying viable E. faecalis cells in marine waters. The developed assay was compared with the standard membrane filter (MF) method by quantifying viable E. faecalis cells in seawater samples exposed to solar radiation. The results of the developed PMA-qPCR assay did not match that of the standard MF method. This difference in the results reflects the different physiological states of E. faecalis cells in seawater. In conclusion, the developed assay is a rapid (∼5 h) method for the quantification of viable E. faecalis cells in marine recreational waters, which should be further improved and tested in different seawater settings. © 2014 Springer-Verlag Berlin Heidelberg.

  12. Limitations and recommendations for successful DNA extraction from forensic soil samples: a review.

    Science.gov (United States)

    Young, Jennifer M; Rawlence, Nicolas J; Weyrich, Laura S; Cooper, Alan

    2014-05-01

    Soil is commonly used in forensic casework to provide discriminatory power to link a suspect to a crime scene. Standard analyses examine the intrinsic properties of soils, including mineralogy, geophysics, texture and colour; however, soils can also support a vast amount of organisms, which can be examined using DNA fingerprinting techniques. Many previous genetic analyses have relied on patterns of fragment length variation produced by amplification of unidentified taxa in the soil extract. In contrast, the development of advanced DNA sequencing technologies now provides the ability to generate a detailed picture of soil microbial communities and the taxa present, allowing for improved discrimination between samples. However, DNA must be efficiently extracted from the complex soil matrix to achieve accurate and reproducible DNA sequencing results, and extraction efficacy is highly dependent on the soil type and method used. As a result, a consideration of soil properties is important when estimating the likelihood of successful DNA extraction. This would include a basic understanding of soil components, their interactions with DNA molecules and the factors that affect such interactions. This review highlights some important considerations required prior to DNA extraction and discusses the use of common chemical reagents in soil DNA extraction protocols to achieve maximum efficacy. Together, the information presented here is designed to facilitate informed decisions about the most appropriate sampling and extraction methodology, relevant both to the soil type and the details of a specific forensic case, to ensure sufficient DNA yield and enable successful analysis. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

  13. Recovery of entire shocked samples in a range of pressure from ~100 GPa to Hugoniot Elastic Limit

    CERN Document Server

    Nagaki, Keita; Sakaiya, Tatsuhiro; Kondo, Tadashi; Kurosawa, Kosuke; Hironaka, Yoichiro; Shigemori, Keisuke; Arakawa, Masahiko

    2016-01-01

    We carried out laser shock experiments and wholly recovered shocked olivine and quartz samples. We investigated the petrographic features based on optical micrographs of sliced samples and found that each recovered sample comprises three regions, I (optically dark), II (opaque) and III (transparent). Scanning electron microscopy combined with electron back-scattered diffraction shows that there are no crystal features in the region I; the materials in the region I have once melted. Moreover, numerical calculations performed with the iSALE shock physics code suggest that the boundary between regions II and III corresponds to Hugoniot Elastic Limit (HEL). Thus, we succeeded in the recovery of the entire shocked samples experienced over a wide range of pressures from HEL (~ 10 GPa) to melting pressure (~ 100 GPa) in a hierarchical order.

  14. Pushing the detection limit of infrared spectroscopy for structural analysis of dilute protein samples.

    Science.gov (United States)

    Baldassarre, Maurizio; Barth, Andreas

    2014-11-07

    Fourier-transform infrared spectroscopy is a powerful and versatile tool to investigate the structure and dynamics of proteins in solution. The intrinsically low extinction coefficient of the amide I mode, the main structure-related oscillator, together with the high infrared absorptivity of aqueous media, requires that proteins are studied at high concentrations (>10 mg L(-1)). This may represent a challenge in the study of aggregation-prone proteins and peptides, and questions the significance of structural data obtained for proteins physiologically existing at much lower concentrations. Here we describe the development of a simple experimental approach that increases the detection limit of protein structure analysis by infrared spectroscopy. Our approach relies on custom-made filters to isolate the amide I region (1700-1600 cm(-1)) from irrelevant spectral regions. The sensitivity of the instrument is then increased by background attenuation, an approach consisting in the use of a neutral density filter, such as a non-scattering metal grid, to attentuate the intensity of the background spectrum. When the filters and grid are combined, a 2.4-fold improvement in the noise level can be obtained. We have successfully tested this approach using a highly diluted solution of pyruvate kinase in deuterated medium (0.2% w/v), and found that it provides spectra of a quality comparable to those recorded with a 10-fold higher protein concentration.

  15. Determination of sample size for a multi-class classifier based on single-nucleotide polymorphisms: a volume under the surface approach.

    Science.gov (United States)

    Liu, Xinyu; Wang, Yupeng; Sriram, T N

    2014-06-14

    Data on single-nucleotide polymorphisms (SNPs) have been found to be useful in predicting phenotypes ranging from an individual's class membership to his/her risk of developing a disease. In multi-class classification scenarios, clinical samples are often limited due to cost constraints, making it necessary to determine the sample size needed to build an accurate classifier based on SNPs. The performance of such classifiers can be assessed using the Area Under the Receiver Operating Characteristic (ROC) Curve (AUC) for two classes and the Volume Under the ROC hyper-Surface (VUS) for three or more classes. Sample size determination based on AUC or VUS would not only guarantee an overall correct classification rate, but also make studies more cost-effective. For coded SNP data from D(≥2) classes, we derive an optimal Bayes classifier and a linear classifier, and obtain a normal approximation to the probability of correct classification for each classifier. These approximations are then used to evaluate the associated AUCs or VUSs, whose accuracies are validated using Monte Carlo simulations. We give a sample size determination method, which ensures that the difference between the two approximate AUCs (or VUSs) is below a pre-specified threshold. The performance of our sample size determination method is then illustrated via simulations. For the HapMap data with three and four populations, a linear classifier is built using 92 independent SNPs and the required total sample sizes are determined for a continuum of threshold values. In all, four different sample size determination studies are conducted with the HapMap data, covering cases involving well-separated populations to poorly-separated ones. For multi-classes, we have developed a sample size determination methodology and illustrated its usefulness in obtaining a required sample size from the estimated learning curve. For classification scenarios, this methodology will help scientists determine whether a sample

  16. Scheduling Algorithm for Mission Planning and Logistics Evaluation (SAMPLE). Volume 3: The GREEDY algorithm

    Science.gov (United States)

    Dupnick, E.; Wiggins, D.

    1980-01-01

    The functional specifications, functional design and flow, and the program logic of the GREEDY computer program are described. The GREEDY program is a submodule of the Scheduling Algorithm for Mission Planning and Logistics Evaluation (SAMPLE) program and has been designed as a continuation of the shuttle Mission Payloads (MPLS) program. The MPLS uses input payload data to form a set of feasible payload combinations; from these, GREEDY selects a subset of combinations (a traffic model) so all payloads can be included without redundancy. The program also provides the user a tutorial option so that he can choose an alternate traffic model in case a particular traffic model is unacceptable.

  17. Brief communication: Endocranial volumes in an ontogenetic sample of chimpanzees from the Taï Forest National Park, Ivory Coast.

    Science.gov (United States)

    Neubauer, Simon; Gunz, Philipp; Schwarz, Uta; Hublin, Jean-Jacques; Boesch, Christophe

    2012-02-01

    Ontogenetic samples of endocranial volumes (EVs) from great apes and humans are critical for understanding the evolution of the brain growth pattern in the hominin lineage. However, high quality ontogenetic data are scarce, especially for nonhuman primates. Here, we provide original data derived from an osteological collection of a wild population of Pan troglodytes verus from the Taï Forest National Park, Ivory Coast. This sample is unique, because age, sex, and pedigree information are available for many specimens from behavioral observations in the wild. We scanned crania of all 30 immature specimens and 13 adult individuals using high-resolution computed tomography. We then created virtual casts of the bony braincase (endocasts) to measure EVs. We also measured cranial length, width, and height and attempted to relate cranial distances to EV via regression analysis. Our data are consistent with previous studies. The only neonate in the sample has an EV of 127 cm(3) or 34% of the adult mean. EV increases rapidly during early ontogeny. The average adult EV in this sample is 378.7 ± 30.1 cm(3) . We found sexual dimorphism in adults; males seem to be already larger than females before adult EV is attained. Regressions on cranial width and multiple regression provide better estimates for EV than regressions on cranial length or height. Increasing the sample size and compiling more high quality ontogenetic data of EV will help to reconcile ongoing discussions about the evolution of hominin brain growth. Copyright © 2011 Wiley Periodicals, Inc.

  18. ARPA-E Impacts: A Sampling of Project Outcomes, Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Rohlfing, Eric [Dept. of Energy (DOE), Washington DC (United States). Advanced Research Projects Agency-Energy (ARPA-E)

    2017-02-27

    The Advanced Research Projects Agency-Energy (ARPA-E) is demonstrating that a collaborative model has the power to deliver real value. The Agency’s first compilation booklet of impact sheets, published in 2016, began to tell the story of how ARPA-E has already made an impact in just seven years—funding a diverse and sophisticated research portfolio on advanced energy technologies that enable the United States to tackle our most pressing energy challenges. One year later our research investments continue to pay off, with a number of current and alumni project teams successfully commercializing their technologies and advancing the state of the art in transformative areas of energy science and engineering. There is no single measure that can fully illustrate ARPA-E’s success to date, but several statistics viewed collectively begin to reveal the Agency’s impact. Since 2009, ARPA-E has provided more than $1.5 billion in funding for 36 focused programs and three open funding solicitations, totaling over 580 projects. Of those, 263 are now alumni projects. Many teams have successfully leveraged ARPA-E’s investment: 56 have formed new companies, 68 have partnered with other government agencies to continue their technology development, and 74 teams have together raised more than $1.8 billion in reported funding from the private sector to bring their technologies to market. However, even when viewed together, those measures do not capture ARPA-E’s full impact. To best understand the Agency’s success, the specific scientific and engineering challenges that ARPA-E project teams have overcome must be understood. This booklet provides concrete examples of those successes, ranging from innovations that will bear fruit in the future to ones that are beginning to penetrate the market as products today. Importantly, half of the projects highlighted in this volume stem from OPEN solicitations, which the agency has run in 2009, 2012, and 2015. ARPA-E’s OPEN programs

  19. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

    Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

  20. Natural air ventilation in underground galleries as a tool to increase radon sampling volumes for geologic monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Eff-Darwich, Antonio [Departamento de Edafologia y Geologia, Universidad de La Laguna, Av. Astrofisico Francisco, Sanchez s/n, 38206 La Laguna, Tenerife (Spain); Instituto de Astrofisica de Canarias, c/Via Lactea s/n, 38205 La Laguna, Tenerife (Spain)], E-mail: adarwich@ull.es; Vinas, Ronaldo [Departamento de Edafologia y Geologia, Universidad de La Laguna, Av. Astrofisico Francisco, Sanchez s/n, 38206 La Laguna, Tenerife (Spain); Soler, Vicente [Estacion Volcanologica de Canarias, IPNA-CSIC, Av. Astrofisico Francisco Sanchez s/n, 38206 La Laguna, Tenerife (Spain); Nuez, Julio de la; Quesada, Maria L. [Departamento de Edafologia y Geologia, Universidad de La Laguna, Av. Astrofisico Francisco, Sanchez s/n, 38206 La Laguna, Tenerife (Spain)

    2008-09-15

    A simple numerical model was implemented to infer airflow (natural ventilation) in underground tunnels from the differences in the temporal patterns of radon, {sup 222}Rn, concentration time-series that were measured at two distant points in the interior of the tunnels. The main purpose of this work was to demonstrate that the installation of radon monitoring stations closer to the entrance of the tunnels was sufficient to remotely analyse the distribution of radon concentration in their interiors. This could ease the monitoring of radon, since the effective sampling volume of a single monitoring station located closer to the entrance of a tunnel is approximately 30,000 times larger than the sampling volume of a sub-soil radon sensor. This methodology was applied to an underground gallery located in the volcanic island of Tenerife, Canary Islands. This island constitutes an ideal laboratory to study the geo-dynamical behaviour of radon because of the existence of a vast network of galleries that conforms the main water supply of the island.

  1. Highly sensitive SERS detection of cancer proteins in low sample volume using hollow core photonic crystal fiber.

    Science.gov (United States)

    U S, Dinish; Fu, Chit Yaw; Soh, Kiat Seng; Ramaswamy, Bhuvaneswari; Kumar, Anil; Olivo, Malini

    2012-03-15

    Enzyme-linked immunosorbent assays (ELISA) are commonly used for detecting cancer proteins at concentration in the range of about ng-μg/mL. Hence it often fails to detect tumor markers at the early stages of cancer and other diseases where the amount of protein is extremely low. Herein, we report a novel photonic crystal fiber (PCF) based surface enhanced Raman scattering (SERS) sensing platform for the ultrasensitive detection of cancer proteins in an extremely low sample volume. As a proof of concept, epidermal growth factor receptors (EGFRs) in a lysate solution from human epithelial carcinoma cells were immobilized into the hollow core PCF. Highly sensitive detection of protein was achieved using anti-EGFR antibody conjugated SERS nanotag. This SERS nanotag probe was realized by anchoring highly active Raman molecules onto the gold nanoparticles followed by bioconjugation. The proposed sensing method can detect low amount of proteins at ∼100 pg in a sample volume of ∼10 nL. Our approach may lead to the highly sensitive protein sensing methodology for the early detection of diseases.

  2. Pushing the limits: detecting H2 emission from faint bipolar planetary nebulae in the IPHAS sample

    Science.gov (United States)

    Ramos-Larios, G.; Guerrero, M. A.; Sabin, L.; Santamaría, E.

    2017-09-01

    We have obtained deep narrowband images in the near-infrared H2 λ2.122 μm emission line for a sample of 15 faint Isaac Newton Telescope Photometric H α Survey (IPHAS) bipolar planetary nebulae (PNe) to search for molecular material. H2 emission is found in most of them (14 out of 15), mostly associated with rings at their equatorial regions and with their bipolar lobes. These detections add to the high occurrence of H2 emission among bipolar PNe reported in previous works, resulting from the large reservoir of molecular material in these sources and the suitable excitation conditions for H2 emission. The correlation between detailed bipolar morphology and H2 luminosity is also confirmed: bipolar PNe with broad equatorial rings (R-BPNe) have almost no continuum emission, are H2 brighter and have larger H2/Br γ line ratio than bipolar PNe with pinched equatorial waists (W-BPNe). The origin of this dichotomy is unclear. The larger size and age of R-BPNe are consistent with shock excitation of H2, whereas ultraviolet pumping is most likely the excitation mechanism in the smaller and younger W-BPNe, which would explain their lower H2 luminosity. Although both types of bipolar PNe seem to proceed from the same progenitor population, this does not imply that R-BPNe descend from W-BPNe. Otherwise, we note that some of the H2-weak bipolar PNe harbor post-common envelope binary systems and symbiotic stars. Finally, we suggest that the long-living H2 emission from R-BPNe arises from a discrete distribution of compact knots embedded within the ionized gas at the equatorial region.

  3. Reconstruction of band-limited signals from multichannel and periodic nonuniform samples in the linear canonical transform domain

    Science.gov (United States)

    Wei, Deyun; Ran, Qiwen; Li, Yuanmin

    2011-09-01

    Linear canonical transforms (LCTs) are a family of integral transforms with wide application in optical, acoustical, electromagnetic, and other wave propagation problems. This paper addresses the problem of signal reconstruction from multichannel and periodic nonuniform samples in the LCT domain. Firstly, the multichannel sampling theorem (MST) for band-limited signals with the LCT is proposed based on multichannel system equations, which is the generalization of the well-known sampling theorem for the LCT. We consider the problem of reconstructing the signal from its samples which are acquired using a multichannel sampling scheme. For this purpose, we propose two alternatives. The first scheme is based on the conventional Fourier series and inverse LCT operation. The second is based on the conventional Fourier series and inverse Fourier transform (FT) operation. Moreover, the classical Papoulis MST in FT domain is shown to be special case of the achieved results. Since the periodic nonuniformly sampled signal in the LCT has valuable applications, the reconstruction expression for the periodic nonuniformly sampled signal has been then obtained by using the derived MST and the specific space-shifting property of the LCT. Last, the potential applications of the MST are presented to show the advantage of the theory.

  4. COMBINED REDUCED FORCED EXPIRATORY VOLUME IN 1-SECOND (FEV1) AND PERIPHERAL ARTERY DISEASE IN SEDENTARY ELDERS WITH FUNCTIONAL LIMITATIONS

    Science.gov (United States)

    Vaz Fragoso, Carlos A.; Hsu, Fang-Chi; Brinkley, Tina; Church, Timothy; Liu, Christine K.; Manini, Todd; Newman, Anne B.; Stafford, Randall S.; McDermott, Mary M.; Gill, Thomas M.

    2014-01-01

    Objectives Because they are potentially modifiable and may coexist, we evaluated the combined occurrence of a reduced forced expiratory volume in 1-second (FEV1) and peripheral artery disease (PAD), including its association with exertional symptoms, physical inactivity, and impaired mobility, in sedentary elders with functional limitations. Design Cross-sectional. Setting Lifestyle Interventions and Independence in Elder (LIFE) Study. Participants 1307 sedentary community-dwelling persons, mean age 78.9, with functional limitations (Short Physical Performance Battery [SPPB] <10). Measurements A reduced FEV1 was defined by a Z-score <-1.64 (< lower limit of normal), while PAD was defined by an ankle-brachial index <1.00. Exertional dyspnea was defined as moderate-to-severe (modified Borg index), immediately after a 400-meter walk test (400MWT). Exertional leg symptoms were established by the San Diego Claudication Questionnaire. Physical inactivity was evaluated by percent of accelerometry wear-time with activity <100 counts/min (top quartile established high sedentary-time). Mobility was evaluated by the 400MWT (gait-speed <0.8 m/s defined as slow) and SPPB (≤7 defined moderate-to-severe mobility impairment). Results A combined reduced FEV1 and PAD was established in 6.0% (78/1307) of participants. However, among those who had a reduced FEV1, 34.2% (78/228) also had PAD, while 20.8% (78/375) of those who had PAD also had a reduced FEV1. The two combined conditions were associated with exertional dyspnea (adjusted odds ratio [adjOR] 2.59 [1.20, 5.60]) and slow gait-speed (adjOR 3.15 [1.72, 5.75]) but not with exertional leg symptoms, high sedentary-time, and moderate-to-severe mobility impairment. Conclusions In sedentary community-dwelling elders with functional limitations, a reduced FEV1 and PAD frequently coexisted and, in combination, were strongly associated with exertional dyspnea and slow gait-speed (a frailty indicator that increases the risk of

  5. Numerical study on modeling of liquid film flow under countercurrent flow limitation in volume of fluid method

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Taro, E-mail: watanabe_t@qe.see.eng.osaka-u.ac.jp [Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita-shi, Osaka 565-7895 (Japan); Takata, Takashi, E-mail: takata.takashi@jaea.go.jp [Japan Atomic Energy Agency, 4002 Narita-chou, Oarai-machi, Higashi-Ibaraki-gun, Ibaraki 331-1393 (Japan); Yamaguchi, Akira, E-mail: yamaguchi@n.t.u-tokyo.ac.jp [Graduate School of Engineering, The University of Tokyo, 2-22 Shirakata-Shirane, Tokai-mura, Naka-gun, Ibaraki 319-1188 (Japan)

    2017-03-15

    Highlights: • Thin liquid film flow under CCFL was modeled and coupled with the VOF method. • The difference of the liquid flow rate in experiments of CCFL was evaluated. • The proposed VOF method can quantitatively predict CCFL with low computational cost. - Abstract: Countercurrent flow limitation (CCFL) in a heat transfer tube at a steam generator (SG) of pressurized water reactor (PWR) is one of the important issues on the core cooling under a loss of coolant accident (LOCA). In order to improve the prediction accuracy of the CCFL characteristics in numerical simulations using the volume of fluid (VOF) method with less computational cost, a thin liquid film flow in a countercurrent flow is modeled independently and is coupled with the VOF method. The CCFL characteristics is evaluated analytically in condition of a maximizing down-flow rate as a function of a void fraction or a liquid film thickness considering a critical thickness. Then, we have carried out numerical simulations of a countercurrent flow in a vertical tube so as to investigate the CCFL characteristics and compare them with the previous experimental results. As a result, it has been concluded that the effect of liquid film entrainment by upward gas flux will cause the difference in the experiments.

  6. Analysis of Three Compounds in Flos Farfarae by Capillary Electrophoresis with Large-Volume Sample Stacking

    Directory of Open Access Journals (Sweden)

    Hai-xia Yu

    2017-01-01

    Full Text Available The aim of this study was to develop a method combining an online concentration and high-efficiency capillary electrophoresis separation to analyze and detect three compounds (rutin, hyperoside, and chlorogenic acid in Flos Farfarae. In order to get good resolution and enrichment, several parameters such as the choice of running buffer, pH and concentration of the running buffer, organic modifier, temperature, and separation voltage were all investigated. The optimized conditions were obtained as follows: the buffer of 40 mM NaH2P04-40 mM Borax-30% v/v methanol (pH 9.0; the sample hydrodynamic injection of up to 4 s at 0.5 psi; 20 kV applied voltage. The diode-array detector was used, and the detection wavelength was 364 nm. Based on peak area, higher levels of selective and sensitive improvements in analysis were observed and about 14-, 26-, and 5-fold enrichment of rutin, hyperoside, and chlorogenic acid were achieved, respectively. This method was successfully applied to determine the three compounds in Flos Farfarae. The linear curve of peak response versus concentration was from 20 to 400 µg/ml, 16.5 to 330 µg/mL, and 25 to 500 µg/mL, respectively. The regression coefficients were 0.9998, 0.9999, and 0.9991, respectively.

  7. Ultra-trace plutonium determination in small volume seawater by sector field inductively coupled plasma mass spectrometry with application to Fukushima seawater samples.

    Science.gov (United States)

    Bu, Wenting; Zheng, Jian; Guo, Qiuju; Aono, Tatsuo; Tagami, Keiko; Uchida, Shigeo; Tazoe, Hirofumi; Yamada, Masatoshi

    2014-04-11

    Long-term monitoring of Pu isotopes in seawater is required for assessing Pu contamination in the marine environment from the Fukushima Dai-ichi Nuclear Power Plant accident. In this study, we established an accurate and precise analytical method based on anion-exchange chromatography and SF-ICP-MS. This method was able to determine Pu isotopes in seawater samples with small volumes (20-60L). The U decontamination factor was 3×10(7)-1×10(8), which provided sufficient removal of interfering U from the seawater samples. The estimated limits of detection for (239)Pu and (240)Pu were 0.11fgmL(-1) and 0.08fgmL(-1), respectively, which corresponded to 0.01mBqm(-3) for (239)Pu and 0.03mBqm(-3) for (240)Pu when a 20L volume of seawater was measured. We achieved good precision (2.9%) and accuracy (0.8%) for measurement of the (240)Pu/(239)Pu atom ratio in the standard Pu solution with a (239)Pu concentration of 11fgmL(-1) and (240)Pu concentration of 2.7fgmL(-1). Seawater reference materials were used for the method validation and both the (239+240)Pu activities and (240)Pu/(239)Pu atom ratios agreed well with the expected values. Surface and bottom seawater samples collected off Fukushima in the western North Pacific since March 2011 were analyzed. Our results suggested that there was no significant variation of the Pu distribution in seawater in the investigated areas compared to the distribution before the accident.

  8. Validation of whole genome amplification for analysis of the p53 tumor suppressor gene in limited amounts of tumor samples.

    Science.gov (United States)

    Hasmats, Johanna; Green, Henrik; Solnestam, Beata Werne; Zajac, Pawel; Huss, Mikael; Orear, Cedric; Validire, Pierre; Bjursell, Magnus; Lundeberg, Joakim

    2012-08-24

    Personalized cancer treatment requires molecular characterization of individual tumor biopsies. These samples are frequently only available in limited quantities hampering genomic analysis. Several whole genome amplification (WGA) protocols have been developed with reported varying representation of genomic regions post amplification. In this study we investigate region dropout using a φ29 polymerase based WGA approach. DNA from 123 lung cancers specimens and corresponding normal tissue were used and evaluated by Sanger sequencing of the p53 exons 5-8. To enable comparative analysis of this scarce material, WGA samples were compared with unamplified material using a pooling strategy of the 123 samples. In addition, a more detailed analysis of exon 7 amplicons were performed followed by extensive cloning and Sanger sequencing. Interestingly, by comparing data from the pooled samples to the individually sequenced exon 7, we demonstrate that mutations are more easily recovered from WGA pools and this was also supported by simulations of different sequencing coverage. Overall this data indicate a limited random loss of genomic regions supporting the use of whole genome amplification for genomic analysis.

  9. Method to study sample object size limit of small-angle x-ray scattering computed tomography

    Science.gov (United States)

    Choi, Mina; Ghammraoui, Bahaa; Badal, Andreu; Badano, Aldo

    2016-03-01

    Small-angle x-ray scattering (SAXS) imaging is an emerging medical tool that can be used for in vivo detailed tissue characterization and has the potential to provide added contrast to conventional x-ray projection and CT imaging. We used a publicly available MC-GPU code to simulate x-ray trajectories in a SAXS-CT geometry for a target material embedded in a water background material with varying sample sizes (1, 3, 5, and 10 mm). Our target materials were water solution of gold nanoparticle (GNP) spheres with a radius of 6 nm and a water solution with dissolved serum albumin (BSA) proteins due to their well-characterized scatter profiles at small angles and highly scattering properties. The background material was water. Our objective is to study how the reconstructed scatter profile degrades at larger target imaging depths and increasing sample sizes. We have found that scatter profiles of the GNP in water can still be reconstructed at depths up to 5 mm embedded at the center of a 10 mm sample. Scatter profiles of BSA in water were also reconstructed at depths up to 5 mm in a 10 mm sample but with noticeable signal degradation as compared to the GNP sample. This work presents a method to study the sample size limits for future SAXS-CT imaging systems.

  10. Possibilities for decreasing detection limits of analytical methods for determination of transformation products of unsymmetrical dimethylhydrazine in environmental samples

    Directory of Open Access Journals (Sweden)

    Bulat Kenessov

    2015-12-01

    Full Text Available Most rockets of middle and heavy class launched from Kazakhstan, Russia, China and other countries still use highly toxic unsymmetrical dimethylhydrazine (UDMH as a liquid propellant. Study of migration, distribution and accumulation of UDMH transformation products in environment and human health impact assessment of space rocket activity are currently complicated due to the absence of analytical methods allowing detection of trace concentrations of these compounds in analyzed samples. This paper reviews methods and approaches, which can be applied for development of such methods. Detection limits at a part-per-trillion (ppt level may be achieved using most selective and sensitive methods based on gas or liquid chromatography in combination of tandem or high-resolution mass spectrometry. In addition, 1000-fold concentration of samples or integrated sample preparation methods, e.g., dynamic headspace extraction, are required. Special attention during development and application of such methods must be paid to purity of laboratory air, reagents, glassware and analytical instruments.

  11. Association between waist circumference and gray matter volume in 2344 individuals from two adult community-based samples.

    Science.gov (United States)

    Janowitz, Deborah; Wittfeld, Katharina; Terock, Jan; Freyberger, Harald Jürgen; Hegenscheid, Katrin; Völzke, Henry; Habes, Mohamad; Hosten, Norbert; Friedrich, Nele; Nauck, Matthias; Domanska, Grazyna; Grabe, Hans Jörgen

    2015-11-15

    We analyzed the putative association between abdominal obesity (measured in waist circumference) and gray matter volume (Study of Health in Pomerania: SHIP-2, N=758) adjusted for age and gender by applying volumetric analysis and voxel-based morphometry (VBM) with VBM8 to brain magnetic resonance (MR) imaging. We sought replication in a second, independent population sample (SHIP-TREND, N=1586). In a combined analysis (SHIP-2 and SHIP-TREND) we investigated the impact of hypertension, type II diabetes and blood lipids on the association between waist circumference and gray matter. Volumetric analysis revealed a significant inverse association between waist circumference and gray matter volume. VBM in SHIP-2 indicated distinct inverse associations in the following structures for both hemispheres: frontal lobe, temporal lobes, pre- and postcentral gyrus, supplementary motor area, supramarginal gyrus, insula, cingulate gyrus, caudate nucleus, olfactory sulcus, para-/hippocampus, gyrus rectus, amygdala, globus pallidus, putamen, cerebellum, fusiform and lingual gyrus, (pre-) cuneus and thalamus. These areas were replicated in SHIP-TREND. More than 76% of the voxels with significant gray matter volume reduction in SHIP-2 were also distinct in TREND. These brain areas are involved in cognition, attention to interoceptive signals as satiety or reward and control food intake. Due to our cross-sectional design we cannot clarify the causal direction of the association. However, previous studies described an association between subjects with higher waist circumference and future cognitive decline suggesting a progressive brain alteration in obese subjects. Pathomechanisms may involve chronic inflammation, increased oxidative stress or cellular autophagy associated with obesity.

  12. Predominantly Low Metallicities Measured in a Stratified Sample of Lyman Limit Systems at z=3.7

    CERN Document Server

    Glidden, Ana; Cooksey, Kathy L; Simcoe, Robert A; O'Meara, John M

    2016-01-01

    We analyzed metallicities for 33 z=3.4-4.2 absorption line systems with large neutral hydrogen column densities, drawn from a sample of H I-selected of Lyman limit systems (LLSs) identified in Sloan Digital Sky Survey (SDSS) quasar spectra, and stratified based on metal line features. We obtained higher-resolution spectra with the Keck Echellette Spectrograph and Imager (ESI), selecting targets according to our stratification scheme in an effort to fully sample the LLS population metallicity distribution. We established a plausible range of H I column densities and measured the metal column densities (or limits) for ions of carbon, silicon, and aluminum. With simulations, we found ionization-corrected metallicities or upper limits, when appropriate. Interestingly, our ionization models were better constrained with enhanced {\\alpha}-to-aluminum abundances, with a median abundance ratio of [{\\alpha}/Al]=0.3. Measured metallicities were generally low, ranging from [M/H]=-3 to -1.68, with even lower metallicities...

  13. Extension of a dynamic headspace multi-volatile method to milliliter injection volumes with full sample evaporation: Application to green tea.

    Science.gov (United States)

    Ochiai, Nobuo; Sasamoto, Kikuo; Tsunokawa, Jun; Hoffmann, Andreas; Okanoya, Kazunori; MacNamara, Kevin

    2015-11-20

    An extension of multi-volatile method (MVM) technology using the combination of a standard dynamic headspace (DHS) configuration, and a modified DHS configuration incorporating an additional vacuum module, was developed for milliliter injection volume of aqueous sample with full sample evaporation. A prior step involved investigation of water management by weighing of the water residue in the adsorbent trap. The extended MVM for 1 mL aqueous sample consists of five different DHS method parameter sets including choice of the replaceable adsorbent trap. An initial two DHS sampling sets at 25°C with the standard DHS configuration using a carbon-based adsorbent trap target very volatile solutes with high vapor pressure (>10 kPa) and volatile solutes with moderate vapor pressure (1-10 kPa). Subsequent three DHS sampling sets at 80°C with the modified DHS configuration using a Tenax TA trap target solutes with low vapor pressure (88%) for 17 test aroma compounds and moderate recoveries (44-71%) for 4 test compounds. The method showed good linearity (r(2)>0.9913) and high sensitivity (limit of detection: 0.1-0.5 ng mL(-1)) even with MS scan mode. The improved sensitivity of the method was demonstrated with analysis of a wide variety of aroma compounds in brewed green tea. Compared to the original 100 μL MVM procedure, this extension to 1 mL MVM allowed detection of nearly twice the number of aroma compounds, including 18 potent aroma compounds from top-note to base-note (e.g. 2,3-butanedione, coumarin, furaneol, guaiacol, cis-3-hexenol, linalool, maltol, methional, 3-methyl butanal, 2,3,5-trimethyl pyrazine, and vanillin). Sensitivity for 23 compounds improved by a factor of 3.4-15 under 1 mL MVM conditions.

  14. Application of passive sampling devices based on multi-walled carbon nanotubes for the isolation of selected pharmaceuticals and phenolic compounds in water samples - possibilities and limitations.

    Science.gov (United States)

    Jakubus, Aleksandra; Tyma, Magdalena; Stepnowski, Piotr; Paszkiewicz, Monika

    2017-03-01

    Nowadays, carbon nanotubes, as commercially available materials, have attracted great attention because of their unique physicochemical properties, especially their strong adsorption abilities. This paper deals with the possibilities and limitations of the application of multi-walled carbon nanotubes as an alternative sorbent in passive sampling devices for the isolation of selected pharmaceuticals and phenolic compounds directly in water samples. Compounds with different properties, including sulfapyridine, sulfamethoxazole, carbamazepine, p-nitrophenol, 17-β-estradiol, 3,5-dichlorophenol and diclofenac were selected as model compounds. Firstly, the influence of several parameters on the extraction efficiency was defined, then the matrix effect and standard validation parameters were established. Under optimized conditions, the proposed analytical methods exhibited good validation parameters, including excellent linearity with R(2) >0.999, the LODs were found to be between 0.01-0.5μgL(-1) and the LOQ ranged from 0.05 to 1.5μgL(-1). Recovery values obtained for model compounds were 79,8±0.2% for sulfapyridine, 41,5±0.1% for sulfamethoxazole, 96,6±1,5% for carbamazepine, 70,5±0.1% for p-nitrophenol, 77,1±0.5% for 17-β-estradiol, 103,1±1.8% for 3,5-dichlorophenol and 76,3±1.4% for diclofenac. This study provides useful data regarding the sorption process on MWCNTs and definitely evaluates the application potential of these types of sorbents in passive sampling devices.

  15. Limited sampling strategy for prolonged-release tacrolimus in renal transplant patients by use of the dried blood spot technique.

    Science.gov (United States)

    van Boekel, G A J; Donders, A R T; Hoogtanders, K E J; Havenith, T R A; Hilbrands, L B; Aarnoutse, R E

    2015-07-01

    The aim of this study was to develop a clinically applicable limited sampling strategy for ambulatory Caucasian kidney transplant patients to estimate area under the curve in a 24-h period (AUC0-24) of prolonged-release tacrolimus. Twenty six kidney recipients, at least 6 months after transplantation, receiving prolonged-release tacrolimus, were enrolled. In each patient, seven blood samples were collected during a period of 24 h by use of the validated dried blood spot method. Best subset selection multiple linear regression was performed to derive limited sampling strategy (LSS). The equations were constrained to include a maximum of three samples collected within 4 h after the intake to maintain clinical applicability. To assess the predictive performance of LSS, residuals for each patient were calculated based on models fitted to a dataset where that patient was omitted. The prediction formula for the AUC(0-24) using the time points 0, 2, and 4 h after ingestion (C(0h)-C(2h)-C(4h)) provided the highest correlation with the AUC(0-24) (r(2) = 0.95): AUC0-24 = 44.9 + 8.9 × C(0h) + 2.1 × C(2h) + 7.6 × C(4h). Measures for bias and precision, i.e., median percentage prediction error (MPPE) and median absolute prediction error (MAPE), were 0.4 and 4.8%, respectively. For the same patients, the correlation between C(24h) and AUC0-24 was worse (r(2) = 0.77) while MPPE and MAPE were 6.2 and 7.2%, respectively. In the outpatient department, a LSS using C(0h)-C(2h)-C(4h) can be used for reliable estimation of the AUC(0-24) of prolonged-release tacrolimus.

  16. [A limited sampling strategy of phenotyping probe midazolam to predict inhibited activities of hepatic CYP3A in rats].

    Science.gov (United States)

    Zhu, Xue-hui; Jiao, Jian-jie; Zhang, Cai-li; Lou, Jian-shi; Liu, Chang-xiao

    2008-09-01

    The present study was to evaluate feasibility of a limited sampling strategy (LSS) in the prediction of inhibited hepatic CYP3A activity with systemic clearance of midazolam (MDZ), a hepatic CYP3A activity phenotyping probe. Rats were pretreated with a serial doses of ketoconazole, a selective inhibitor on CYP3A. Blood samples were collected and detected for MDZ at specified time points after intravenous injection of MDZ. Stepwise regression analysis and a Jack-knife validation procedures were performed in one group of rats as training set to establish the most informative LSS model for accurately estimating the clearance of MDZ. Another group of rats with same treatment was used as validation set to estimate the individual clearance based on predictive equations derived from the training set. Bland-Altman plots showed a good agreement between the systemic clearance calculated from DAS (CLobs) and corresponding parameter that was derived from three LSS models (CLest). LSS models derived from two or three sampling time points, including 60, 90 min, 30, 60, 90 min and 30, 60, 120 min, exhibited a good accuracy and acceptable error for estimating the CLobs of MDZ to evaluate hepatic CYP3A activity, especially the 60, 90 min LSS model is most accurate and convenient. The results supported that limited plasma sampling to predict the systemic clearance of MDZ is easier than the usual method for estimating CYP3A phenotyping when the hepatic activity of CYP3A is reduced in the rat. The present study provided theoretical basis and laboratory evidence for LSS to clinically evaluate metabolizing function of liver and

  17. Wang--Landau algorithm for entropic sampling of arch-based microstates in the volume ensemble of static granular packings

    Directory of Open Access Journals (Sweden)

    D. Slobinsky

    2015-03-01

    Full Text Available We implement the Wang-Landau algorithm to sample with equal probabilities the static configurations of a model granular system. The "non-interacting rigid arch model" used is based on the description of static configurations by means of splitting the assembly of grains into sets of stable arches. This technique allows us to build the entropy as a function of the volume of the packing for large systems. We make a special note of the details that have to be considered when defining the microstates and proposing the moves for the correct sampling in these unusual models. We compare our results with previous exact calculations of the model made at moderate system sizes. The technique opens a new opportunity to calculate the entropy of more complex granular models. Received: 19 January 2015, Accepted: 25 February 2015; Reviewed by: M. Pica Ciamarra, Nanyang Technological University, Singapore; Edited by: C. S. O'Hern; DOI: http://dx.doi.org/10.4279/PIP.070001 Cite as: D Slobinsky, L A Pugnaloni, Papers in Physics 7, 070001 (2015

  18. Analysis of Six β-Lactam Residues in Milk and Egg by Micellar Electrokinetic Chromatography with Large-Volume Sample Stacking and Polarity Switching.

    Science.gov (United States)

    Shao, Yu-Xiu; Chen, Guan-Hua; Fang, Rou; Zhang, Li; Yi, Ling-Xiao; Meng, Hong-Lian

    2016-05-04

    A new micellar electrokinetic chromatography method with large-volume sample stacking and polarity switching was developed to analyze amoxicllin, cephalexin, oxacillin, penicillin G, cefazolin, and cefoperazone in milk and egg. The important parameters influencing separation and enrichment factors were optimized. The optimized running buffer consisted of 10 mM phosphate and 22 mM SDS at pH 6.7. The sample size was 1.47 kPa × 690 s, the reverse voltage was 20 kV, and the electric current recovery was 95%. Under these optimum conditions, the enrichment factors of six β-lactams were 193-601. Their LODs were <0.26 ng/g, and LOQs were all 2 ng/g, which was only 1/50-1/2 of the maximum residual limits demanded by U.S. and Japanese regulations. The intraday and interday RSDs of method were lower than 3.70 and 3.91%, respectively. The method can be applied to determine these six antibiotic residues in egg and milk.

  19. Large volume sample stacking with EOF and sweeping in CE for determination of common preservatives in cosmetic products by chemometric experimental design.

    Science.gov (United States)

    Cheng, Yi-Cian; Wang, Chun-Chi; Chen, Yen-Ling; Wu, Shou-Mei

    2012-05-01

    This study proposes a capillary electrophoresis method incorporating large volume sample stacking, EOF and sweeping for detection of common preservatives used in cosmetic products. The method was developed using chemometric experimental design (fractional factorial design and central composite design) to determine multiple separation variables by efficient steps. The samples were loaded by hydrodynamic injection (10 psi, 90 s), and separated by phosphate buffer (50 mM, pH 3) containing 30% methanol and 80 mM SDS at -20 kV. During method validation, calibration curves were found to be linear over a range of 5-100 μg/mL for butyl paraben and isobutyl paraben; 0.05-10 μg/mL for ethyl paraben; 0.2-50 μg/mL for dehydroacetic acid; 0.5-70 μg/mL for methyl paraben; 5-350 μg/mL for sorbic acid; 0.02-450 μg/mL for p-hydroxybenzoic acid and 0.05-10 μg/mL for salicylic acid and benzoic acid. The analytes were analysed simultaneously and their detection limits (S/N = 3) were down to 0.005-2 μg/mL. The analysis method was successfully used for detection of preservatives used in commercial cosmetics.

  20. Evaluation of a Bayesian Approach to Estimate Vancomycin Exposure in Obese Patients with Limited Pharmacokinetic Sampling: A Pilot Study.

    Science.gov (United States)

    Carreno, Joseph J; Lomaestro, Ben; Tietjan, John; Lodise, Thomas P

    2017-03-13

    This study evaluated the predictive performance of a Bayesian PK estimation method (ADAPT V) to estimate the 24-hour vancomycin area under the curve estimation (AUC) with limited PK sampling in adult obese patients receiving vancomycin for suspected or confirmed Gram-positive infections. This was an IRB-approved prospective evaluation of 12 patients. Patients had a median (95% CI) age of 61 years (39 - 71), creatinine clearance of 86 mL/min (75 - 120), and body mass index of 45 kg/m(2) (40 - 52). For each patient, five PK concentrations were measured and 4 different vancomycin population PK models were used as Bayesian priors to estimate the estimate vancomycin AUC (AUCFULL). Using each PK model as a prior, data-depleted PK subsets were used to estimate the 24-hour AUC (i.e. peak and trough data [AUCPT], midpoint and trough data [AUCMT], and trough only data [AUCT]). The 24-hour AUC derived from the full data set (AUCFULL) was compared to AUC derived from data depleted subsets (AUCPT, AUCMT, AUCT) for each model. For the 4 sets of analyses, AUCFULL estimates ranged from 437 to 489 mg-h/L. The AUCPT provided the best approximation of the AUCFULL; AUCMT and AUCT tended to overestimate AUCFULL Further prospective studies are needed to evaluate the impact of AUC monitoring in clinical practice but the findings from this study suggest the vancomycin AUC can be estimated good precision and accuracy with limited PK sampling using Bayesian PK estimation software.

  1. Respiratory Allergy and Inflammation Due to Ambient Particles (RAIAP) Collection of Particulate Matter samples from 5 European sites with High Volume Cascade Impactors

    NARCIS (Netherlands)

    Cassee FR; Fokkens PHB; Leseman DLAC; Bloemen HJTh; Boere AJF; MGO

    2003-01-01

    The aim of this deliverable was to perform an European-wide collection of particulate samples. With the aid of two high-volume Cascade impactor (HVCI), coarse (2.5-10 mu m ) and fine (0.1-2.5 mu m) particulate samples were collected in Amsterdam, Lodz, Oslo, Rome and the Dutch sea-side (De Zilk) dur

  2. Respiratory Allergy and Inflammation Due to Ambient Particles (RAIAP) Collection of Particulate Matter samples from 5 European sites with High Volume Cascade Impactors

    NARCIS (Netherlands)

    Cassee FR; Fokkens PHB; Leseman DLAC; Bloemen HJTh; Boere AJF; MGO

    2003-01-01

    The aim of this deliverable was to perform an European-wide collection of particulate samples. With the aid of two high-volume Cascade impactor (HVCI), coarse (2.5-10 mu m ) and fine (0.1-2.5 mu m) particulate samples were collected in Amsterdam, Lodz, Oslo, Rome and the Dutch sea-side (De Zilk)

  3. The Evolution of P-wave Velocity in Fault Gouge: Initial Results for Samples from the SAFOD Volume.

    Science.gov (United States)

    Knuth, M. W.; Tobin, H. J.; Marone, C.

    2008-12-01

    We present initial results from a new technique for observing the evolution of elastic properties in sheared fault zone materials via acoustic wave velocity. The relationship between the mechanical strength of fault gouge and acoustic velocity during active deformation has important implications not only for a physical understanding of elasticity in deforming granular media, but also for the interpretation of the seismic velocity at the field scale. Experiments are conducted at atmospheric temperature and saturation state in a double-direct-shear testing apparatus, with normal stress stepped from 1 to 19 MPa to interrogate behavior during compaction, and sheared at a rate of 10 microns/second to observe changes in velocity with increasing strain. Tests are divided between those involving continuous shear to a displacement of 22.5 mm, and those with intervals of 3.75 mm shear separated by unloading and reloading sequences in normal stress. Velocity is measured by time-of-flight between two piezoelectric P-wave transducers set into the sample configuration on either side of the shearing layers. Samples tested include common laboratory standards for simulated fault gouge and field samples taken from representative localities in the 3D rock volume containing the San Andreas Fault Observatory at Depth experiment in Parkfield, California. The velocities of sand and clay end-member gouges are observed to behave differently under shear, and mixtures of quartz sand and montmorillonite behave differently from both end-member materials. Initial results suggest that particle sorting exerts a strong influence on both the absolute velocity and the evolution of velocity in response to increasing shear strain where the elastic properties of the grains are similar. We also observe a first-order relationship between the coefficient of friction and P-wave velocity that appears to be related to grain reorganization at the onset of shear following initial compaction.

  4. A qualitative analysis of peer recruitment pressures in respondent driven sampling: Are risks above the ethical limit?

    Science.gov (United States)

    Mosher, Heather I; Moorthi, Gayatri; Li, JiangHong; Weeks, Margaret R

    2015-09-01

    This paper examines peer recruitment dynamics through respondent driven sampling (RDS) with a sample of injection drug users in Hartford, CT to understand the strategies participants use to recruit peers into a study and the extent to which these strategies may introduce risks above the ethical limit despite safeguards in RDS. Out of 526 injection drug users who participated in a mixed-method RDS methodology evaluation study, a nested sample of 61 participants completed an in-depth semi-structured interview at a 2-month follow-up to explore their experiences with the recruitment process. Findings revealed that participants used a variety of strategies to recruit peers, ranging from one-time interactions to more persistent strategies to encourage participation (e.g., selecting peers that can easily be found and contacted later, following up with peers to remind them of their appointment, accompanying peers to the study site, etc.). Some participants described the more persistent strategies as helpful, while some others experienced these strategies as minor peer pressure, creating a feeling of obligation to participate. Narratives revealed that overall, the probability of experiencing study-related risks remains relatively low for most participants; however, a disconcerting finding was that higher study-related risks (e.g., relationship conflict, loss of relationship, physical fights, violence) were seen for recruits who participated but switched coupons or for recruits who decided not to participate in the study and did not return the coupon to the recruiter. Findings indicate that peer recruitment practices in RDS generally pose minimal risk, but that peer recruitment may occasionally exceed the ethical limit, and that enhanced safeguards for studies using peer recruitment methods are recommended. Suggestions for possible enhancements are described. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Multi-parametric cytometry from a complex cellular sample: Improvements and limits of manual versus computational-based interactive analyses.

    Science.gov (United States)

    Gondois-Rey, F; Granjeaud, S; Rouillier, P; Rioualen, C; Bidaut, G; Olive, D

    2016-05-01

    The wide possibilities opened by the developments of multi-parametric cytometry are limited by the inadequacy of the classical methods of analysis to the multi-dimensional characteristics of the data. While new computational tools seemed ideally adapted and were applied successfully, their adoption is still low among the flow cytometrists. In the purpose to integrate unsupervised computational tools for the management of multi-stained samples, we investigated their advantages and limits by comparison to manual gating on a typical sample analyzed in immunomonitoring routine. A single tube of PBMC, containing 11 populations characterized by different sizes and stained with 9 fluorescent markers, was used. We investigated the impact of the strategy choice on manual gating variability, an undocumented pitfall of the analysis process, and we identified rules to optimize it. While assessing automatic gating as an alternate, we introduced the Multi-Experiment Viewer software (MeV) and validated it for merging clusters and annotating interactively populations. This procedure allowed the finding of both targeted and unexpected populations. However, the careful examination of computed clusters in standard dot plots revealed some heterogeneity, often below 10%, that was overcome by increasing the number of clusters to be computed. MeV facilitated the identification of populations by displaying both the MFI and the marker signature of the dataset simultaneously. The procedure described here appears fully adapted to manage homogeneously high number of multi-stained samples and allows improving multi-parametric analyses in a way close to the classic approach. © 2016 International Society for Advancement of Cytometry.

  6. A compact time-of-flight SANS instrument optimised for measurements of small sample volumes at the European Spallation Source

    Science.gov (United States)

    Kynde, Søren; Hewitt Klenø, Kaspar; Nagy, Gergely; Mortensen, Kell; Lefmann, Kim; Kohlbrecher, Joachim; Arleth, Lise

    2014-11-01

    The high flux at European Spallation Source (ESS) will allow for performing experiments with relatively small beam-sizes while maintaining a high intensity of the incoming beam. The pulsed nature of the source makes the facility optimal for time-of-flight small-angle neutron scattering (ToF-SANS). We find that a relatively compact SANS instrument becomes the optimal choice in order to obtain the widest possible q-range in a single setting and the best possible exploitation of the neutrons in each pulse and hence obtaining the highest possible flux at the sample position. The instrument proposed in the present article is optimised for performing fast measurements of small scattering volumes, typically down to 2×2×2 mm3, while covering a broad q-range from about 0.005 1/Å to 0.5 1/Å in a single instrument setting. This q-range corresponds to that available at a typical good BioSAXS instrument and is relevant for a wide set of biomacromolecular samples. A central advantage of covering the whole q-range in a single setting is that each sample has to be loaded only once. This makes it convenient to use the fully automated high-throughput flow-through sample changers commonly applied at modern synchrotron BioSAXS-facilities. The central drawback of choosing a very compact instrument is that the resolution in terms of δλ / λ obtained with the short wavelength neutrons becomes worse than what is usually the standard at state-of-the-art SANS instruments. Our McStas based simulations of the instrument performance for a set of characteristic biomacromolecular samples show that the resulting smearing effects still have relatively minor effects on the obtained data and can be compensated for in the data analysis. However, in cases where a better resolution is required in combination with the large simultaneous q-range characteristic of the instrument, we show that this can be obtained by inserting a set of choppers.

  7. A compact time-of-flight SANS instrument optimised for measurements of small sample volumes at the European Spallation Source

    Energy Technology Data Exchange (ETDEWEB)

    Kynde, Søren, E-mail: kynde@nbi.ku.dk [Niels Bohr Institute, University of Copenhagen (Denmark); Hewitt Klenø, Kaspar [Niels Bohr Institute, University of Copenhagen (Denmark); Nagy, Gergely [SINQ, Paul Scherrer Institute (Switzerland); Mortensen, Kell; Lefmann, Kim [Niels Bohr Institute, University of Copenhagen (Denmark); Kohlbrecher, Joachim, E-mail: Joachim.kohlbrecher@psi.ch [SINQ, Paul Scherrer Institute (Switzerland); Arleth, Lise, E-mail: arleth@nbi.ku.dk [Niels Bohr Institute, University of Copenhagen (Denmark)

    2014-11-11

    The high flux at European Spallation Source (ESS) will allow for performing experiments with relatively small beam-sizes while maintaining a high intensity of the incoming beam. The pulsed nature of the source makes the facility optimal for time-of-flight small-angle neutron scattering (ToF-SANS). We find that a relatively compact SANS instrument becomes the optimal choice in order to obtain the widest possible q-range in a single setting and the best possible exploitation of the neutrons in each pulse and hence obtaining the highest possible flux at the sample position. The instrument proposed in the present article is optimised for performing fast measurements of small scattering volumes, typically down to 2×2×2 mm{sup 3}, while covering a broad q-range from about 0.005 1/Å to 0.5 1/Å in a single instrument setting. This q-range corresponds to that available at a typical good BioSAXS instrument and is relevant for a wide set of biomacromolecular samples. A central advantage of covering the whole q-range in a single setting is that each sample has to be loaded only once. This makes it convenient to use the fully automated high-throughput flow-through sample changers commonly applied at modern synchrotron BioSAXS-facilities. The central drawback of choosing a very compact instrument is that the resolution in terms of δλ/λ obtained with the short wavelength neutrons becomes worse than what is usually the standard at state-of-the-art SANS instruments. Our McStas based simulations of the instrument performance for a set of characteristic biomacromolecular samples show that the resulting smearing effects still have relatively minor effects on the obtained data and can be compensated for in the data analysis. However, in cases where a better resolution is required in combination with the large simultaneous q-range characteristic of the instrument, we show that this can be obtained by inserting a set of choppers.

  8. Measurement of the Depth of Penetration of UV Photons into Mars Relevant Rock Samples to Constrain Habitability and Limits of Detection for the SHERLOC Mars 2020 Instrument

    Science.gov (United States)

    Carrier, B. L.; Beegle, L. W.; Bhartia, R.; Abbey, W. J.

    2015-12-01

    We report on the depth of penetration of UV photons into a suite of Mars relevant materials in order to better characterize what constitutes a habitable environment on Mars, as well as to characterize the sensitivities of the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument on the Mars 2020 payload. To date, UV transparency of these rock types have not been fully characterized, and we have performed a systematic study to better constrain the UV attenuation over a wide range of materials relevant to Mars. At one point during the history of Mars, the surface may have been habitable, with flowing liquid water and access to food and energy sources. As surface conditions changed, it is not unreasonable to assume that life would have migrated into the protected interior of porous rocks, veins, fissures, and the subsurface as a means to protect itself from harsh surface conditions, such as the UV flux that we observe today. Given geological time, the depth that UV light penetrates into the subsurface will play a role in altering and/or effecting the preservation of organic molecule containing biosignatures. However, the extent to which various rock types can shield organic material currently is not well understood. In addition to constraining the UV-driven habitable "zone", the data also helps constrain the SHERLOC instrument limits of detection. SHERLOC is a deep UV fluorescence and Raman imaging instrument. This is achieved by spatially scanning a deep UV laser at 248.6 nm to stimulate fluorescence emissions and Raman scattering from the sample. Specifically, fluorescence is generated from electronic transition from aromatic organics and Raman scatter is generated from vibrational bonds from both organics and minerals. Given the excitation wavelength, and the emission/scattering wavelengths (250-350), the mineral transparency will affect the interrogation volume of analysis and thus constrain the limits of

  9. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output

    DEFF Research Database (Denmark)

    Smerup, Morten Holdgaard; Damkjær, Mads; Brøndum, Emil

    2016-01-01

    to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End......-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke...

  10. Whole genome amplification for CGH analysis: Linker-adapter PCR as the method of choice for difficult and limited samples.

    Science.gov (United States)

    Pirker, Christine; Raidl, Maria; Steiner, Elisabeth; Elbling, Leonilla; Holzmann, Klaus; Spiegl-Kreinecker, Sabine; Aubele, Michaela; Grasl-Kraupp, Bettina; Marosi, Christine; Micksche, Michael; Berger, Walter

    2004-09-01

    Comparative genomic hybridization (CGH) is a powerful method to investigate chromosomal imbalances in tumor cells. However, DNA quantity and quality can be limiting factors for successful CGH analysis. The aim of this study was to investigate the applicability of degenerate oligonucleotide-primed PCR (DOP-PCR) and a recently developed linker-adapter-mediated PCR (LA-PCR) for whole genome amplification for use in CGH, especially for difficult source material. We comparatively analyzed DNA of variable quality derived from different cell/tissue types. Additionally, dilution experiments down to the DNA content of a single cell were performed. FISH and/or classical cytogenetic analyses were used as controls. In the case of high quality DNA samples, both methods were equally suitable for CGH. When analyzing very small amounts of these DNA samples (equivalent to one or a few human diploid cells), DOP-PCR-CGH, but not LA-PCR-CGH, frequently produced false-positive signals (e.g., gains in 1p and 16p, and losses in chromosome 4q). In case of formalin-fixed paraffin-embedded tissues, success rates by LA-PCR-CGH were significantly higher as compared to DOP-PCR-CGH. DNA of minor quality frequently could be analyzed correctly by LA-PCR-CGH, but was prone to give false-positive and/or false-negative results by DOP-PCR-CGH. LA-PCR is superior to DOP-PCR for amplification of DNA for CGH analysis, especially in the case of very limited or partly degraded source material. Copyright 2004 Wiley-Liss, Inc

  11. Utilities and offsites design baseline. Outside Battery Limits Facility 6000 tpd SRC-I Demonstration Plant. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    None

    1984-05-25

    Volume 2 contains flowsheets and equipment specifications for the following parts of the plant: cooling water systems, process water supply, potable water supply, nitrogen system, compressed air system, flares, incinerators, fuels and interconnecting systems (pipes). The instrumentation requirements are included. (LTN)

  12. Limited-sampling strategy models for estimating the pharmacokinetic parameters of 4-methylaminoantipyrine, an active metabolite of dipyrone

    Directory of Open Access Journals (Sweden)

    Suarez-Kurtz G.

    2001-01-01

    Full Text Available Bioanalytical data from a bioequivalence study were used to develop limited-sampling strategy (LSS models for estimating the area under the plasma concentration versus time curve (AUC and the peak plasma concentration (Cmax of 4-methylaminoantipyrine (MAA, an active metabolite of dipyrone. Twelve healthy adult male volunteers received single 600 mg oral doses of dipyrone in two formulations at a 7-day interval in a randomized, crossover protocol. Plasma concentrations of MAA (N = 336, measured by HPLC, were used to develop LSS models. Linear regression analysis and a "jack-knife" validation procedure revealed that the AUC0-¥ and the Cmax of MAA can be accurately predicted (R²>0.95, bias 0.85 of the AUC0-¥ or Cmax for the other formulation. LSS models based on three sampling points (1.5, 4 and 24 h, but using different coefficients for AUC0-¥ and Cmax, predicted the individual values of both parameters for the enrolled volunteers (R²>0.88, bias = -0.65 and -0.37%, precision = 4.3 and 7.4% as well as for plasma concentration data sets generated by simulation (R²>0.88, bias = -1.9 and 8.5%, precision = 5.2 and 8.7%. Bioequivalence assessment of the dipyrone formulations based on the 90% confidence interval of log-transformed AUC0-¥ and Cmax provided similar results when either the best-estimated or the LSS-derived metrics were used.

  13. Limited-sampling strategy models for estimating the pharmacokinetic parameters of 4-methylaminoantipyrine, an active metabolite of dipyrone.

    Science.gov (United States)

    Suarez-Kurtz, G; Ribeiro, F M; Estrela, R C; Vicente, F L; Struchiner, C J

    2001-11-01

    Bioanalytical data from a bioequivalence study were used to develop limited-sampling strategy (LSS) models for estimating the area under the plasma concentration versus time curve (AUC) and the peak plasma concentration (Cmax) of 4-methylaminoantipyrine (MAA), an active metabolite of dipyrone. Twelve healthy adult male volunteers received single 600 mg oral doses of dipyrone in two formulations at a 7-day interval in a randomized, crossover protocol. Plasma concentrations of MAA (N = 336), measured by HPLC, were used to develop LSS models. Linear regression analysis and a "jack-knife" validation procedure revealed that the AUC(0-infinity) and the Cmax of MAA can be accurately predicted (R2>0.95, bias 0.85) of the AUC(0-infinity) or Cmax for the other formulation. LSS models based on three sampling points (1.5, 4 and 24 h), but using different coefficients for AUC(0-infinity) and Cmax, predicted the individual values of both parameters for the enrolled volunteers (R2>0.88, bias = -0.65 and -0.37%, precision = 4.3 and 7.4%) as well as for plasma concentration data sets generated by simulation (R2>0.88, bias = -1.9 and 8.5%, precision = 5.2 and 8.7%). Bioequivalence assessment of the dipyrone formulations based on the 90% confidence interval of log-transformed AUC(0-infinity) and Cmax provided similar results when either the best-estimated or the LSS-derived metrics were used.

  14. Efficacy and limits of genotyping low copy number (LCN) DNA samples by multiplex PCR of STR loci.

    Science.gov (United States)

    Kloosterman, Ate D; Kersbergen, Paula

    2003-01-01

    In this study, we have evaluated the efficacy and the validity of the AmpFISTR SGM plus multiplex PCR typing system when Low Copy Number (LCN) amounts of DNA are processed. The characteristics of SGM plus profiles produced under LCN conditions were studied on the basis of heterozygote balance, between loci balance and stutter proportion based on profiles that were obtained from a variety of mock casework samples. These experiments clearly showed that LCN DNA profiles carry their own characteristic features, which must be taken into account during interpretation. Herewith, we confirmed the data of recent other studies that a comprehensive interpretation strategy is dependent upon multiple replication of the PCR using the same extract together with the proper use of extraction and amplification controls. The limitations of LCN DNA analysis were further studied in a series of single cell PCR experiments using an amplification regime of 34 PCR cycles. The allele dropout phenomenon was demonstrated to its full extent when single cells were analysed. However, the "consensus profile" which was obtained from separate single cell PCR experiments matched the actual profile of the cell donor. Single cell PCR experiments also showed that a further increase of the number of PCR cycles did not result in enhanced sensitivity and had a highly negative effect on the balance of this multiplex PCR system which hampered correct interpretation of the profile. Also, the potential of LCN typing in analysing mixtures of DNA was investigated. It was clearly shown that LCN typing had no advantages over 28 cycles amplification in the detection of the minor component of DNA-mixtures. In addition to the 34 cycles PCR amplification regime, the utility of a new approach that involved reamplification of the 28 cycle SGM plus PCR products with an extra 6 PCR cycles after the addition of fresh AmpliTaq Gold DNA Polymerase was investigated. This approach provides the scientist with an extra typing

  15. Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid on-site gas analysis

    Science.gov (United States)

    Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke

    2017-08-01

    In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH4+ strategy for ethylene and SO2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO2 from fruits. It was satisfied that trace ethylene and SO2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO2 during the entire LVCC sampling process were proved to be samples were achieved in range of 95.0-101% and 97.0-104% respectively. It is expected that portable LVCC sampling technique would pave the way for rapid on-site analysis of accurate concentrations of trace gas targets from real samples by SERS.

  16. Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid on-site gas analysis.

    Science.gov (United States)

    Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke

    2017-08-05

    In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH4(+) strategy for ethylene and SO2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO2 from fruits. It was satisfied that trace ethylene and SO2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO2 during the entire LVCC sampling process were proved to be samples were achieved in range of 95.0-101% and 97.0-104% respectively. It is expected that portable LVCC sampling technique would pave the way for rapid on-site analysis of accurate concentrations of trace gas targets from real samples by SERS. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Evaluation of the programmed temperature vaporiser for large-volume injection of biological samples in gas chromatography

    NARCIS (Netherlands)

    van Hout, M.W J; de Zeeuw, R.A; Franke, J.P.; de Jong, G.J.

    1999-01-01

    The use of a programmed temperature vaporiser (PTV) with a packed liner was evaluated for the injection of large volumes (up to 100 mu l) of plasma extracts in a gas chromatograph. Solvent purity, which is essential when large volumes are injected into the GC system, was determined. Special attentio

  18. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output.

    Science.gov (United States)

    Smerup, Morten; Damkjær, Mads; Brøndum, Emil; Baandrup, Ulrik T; Kristiansen, Steen Buus; Nygaard, Hans; Funder, Jonas; Aalkjær, Christian; Sauer, Cathrine; Buchanan, Rasmus; Bertelsen, Mads Frost; Østergaard, Kristine; Grøndahl, Carsten; Candy, Geoffrey; Hasenkam, J Michael; Secher, Niels H; Bie, Peter; Wang, Tobias

    2016-02-01

    Giraffes--the tallest extant animals on Earth--are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but produce a lowered cardiac output.

  19. A coupled phase-field and volume-of-fluid method for accurate representation of limiting water wave deformation

    Science.gov (United States)

    Liu, Yu; Yu, Xiping

    2016-09-01

    A coupled phase-field and volume-of-fluid method is developed to study the sensitive behavior of water waves during breaking. The THINC model is employed to solve the volume-of-fluid function over the entire domain covered by a relatively coarse grid while the phase-field model based on Allen-Cahn equation is applied over the fine grid. A special algorithm that takes into account the sharpness of the diffuse-interface is introduced to correlate the order parameter obtained on the fine grid and the volume-of-fluid function obtained on the coarse grid. The coupled model is then applied to the study of water waves generated by moving pressures on the free surface. The deformation process of the wave crest during the initial stage of breaking is discussed in details. It is shown that there is a significant variation of the free nappe developed at the front side of the wave crest as the wave steepness differs. It is of a plunging type at large wave steepness while of a spilling type at small wave steepness. The numerical results also indicate that breaking occurs later and the duration of breaking is shorter for waves of smaller steepness and vice versa. Neglecting the capillary effect leads to wave breaking with a sharper nappe and a more dynamic plunging process. The surface tension also has an effect to prevent the formation of a free nappe at the front side of the wave crest in some cases.

  20. Prostate specific antigen in a community-based sample of men without prostate cancer: Correlations with prostate volume, age, body mass index, and symptoms of prostatism

    NARCIS (Netherlands)

    J.L.H.R. Bosch (Ruud); W.C.J. Hop (Wim); C.H. Bangma (Chris); W.J. Kirkels (Wim); F.H. Schröder (Fritz)

    1995-01-01

    textabstractThe correlation between both prostate specific antigen levels (PSA) and prostate specific antigen density (PSAD) and age, prostate volume parameters, body mass index, and the International Prostate Symptom Score (IPSS) were studied in a community‐based population. A sample of 502 men age

  1. A study of toxic emissions from a coal-fired power plant: Niles Station Boiler No. 2. Volume 1, Sampling/results/special topics: Final report

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    This study was one of a group of assessments of toxic emissions from coal-fired power plants, conducted for US Department of Energy, Pittsburgh Energy Technology Center (DOE-PETC) during 1993. The motivation for those assessments was the mandate in the 1990 Clean Air Act Amendments that a study be made of emissions of hazardous air pollutants (HAPs) from electrical utilities. The results of this study will be used by the US Environmental Protection Agency to evaluate whether regulation of HAPs emissions from utilities is warranted. This report is organized in two volumes. Volume 1: Sampling/Results/Special Topics describes the sampling effort conducted as the basis for this study, presents the concentration data on toxic chemicals in the several power plant streams, and reports the results of evaluations and calculations conducted with those data. The Special Topics section of Volume 1 reports on issues such as comparison of sampling methods and vapor/particle distributions of toxic chemicals. Volume 2: Appendices include field sampling data sheets, quality assurance results, and uncertainty calculations. The chemicals measured at Niles Boiler No. 2 were the following: five major and 16 trace elements, including mercury, chromium, cadmium, lead, selenium, arsenic, beryllium, and nickel; acids and corresponding anions (HCl, HF, chloride, fluoride, phosphate, sulfate); ammonia and cyanide; elemental carbon; radionuclides; volatile organic compounds (VOC); semivolatile compounds (SVOC) including polynuclear aromatic hydrocarbons (PAH), and polychlorinated dioxins and furans; and aldehydes.

  2. Effects of pore-scale dispersion, degree of heterogeneity, sampling size, and source volume on the concentration moments of conservative solutes in heterogeneous formations

    Science.gov (United States)

    Daniele Tonina; Alberto Bellin

    2008-01-01

    Pore-scale dispersion (PSD), aquifer heterogeneity, sampling volume, and source size influence solute concentrations of conservative tracers transported in heterogeneous porous formations. In this work, we developed a new set of analytical solutions for the concentration ensemble mean, variance, and coefficient of variation (CV), which consider the effects of all these...

  3. Sample Preparation and Extraction in Small Sample Volumes Suitable for Pediatric Clinical Studies: Challenges, Advances, and Experiences of a Bioanalytical HPLC-MS/MS Method Validation Using Enalapril and Enalaprilat

    Directory of Open Access Journals (Sweden)

    Bjoern B. Burckhardt

    2015-01-01

    Full Text Available In USA and Europe, medicines agencies force the development of child-appropriate medications and intend to increase the availability of information on the pediatric use. This asks for bioanalytical methods which are able to deal with small sample volumes as the trial-related blood lost is very restricted in children. Broadly used HPLC-MS/MS, being able to cope with small volumes, is susceptible to matrix effects. The latter restrains the precise drug quantification through, for example, causing signal suppression. Sophisticated sample preparation and purification utilizing solid-phase extraction was applied to reduce and control matrix effects. A scale-up from vacuum manifold to positive pressure manifold was conducted to meet the demands of high-throughput within a clinical setting. Faced challenges, advances, and experiences in solid-phase extraction are exemplarily presented on the basis of the bioanalytical method development and validation of low-volume samples (50 μL serum. Enalapril, enalaprilat, and benazepril served as sample drugs. The applied sample preparation and extraction successfully reduced the absolute and relative matrix effect to comply with international guidelines. Recoveries ranged from 77 to 104% for enalapril and from 93 to 118% for enalaprilat. The bioanalytical method comprising sample extraction by solid-phase extraction was fully validated according to FDA and EMA bioanalytical guidelines and was used in a Phase I study in 24 volunteers.

  4. A Fundamental Limitation of Small Diameter Single-Walled Carbon Nanotube Synthesis—A Scaling Rule of the Carbon Nanotube Yield with Catalyst Volume

    Directory of Open Access Journals (Sweden)

    Kenji Hata

    2013-07-01

    Full Text Available Understanding the fundamental mechanisms and limiting processes of the growth of single-walled carbon nanotube (SWCNT would serve as a guide to achieve further control on structural parameters of SWCNT. In this paper, we have studied the growth kinetics of a series of SWCNT forests continuously spanning a wide range of diameters (1.9–3.2 nm, and have revealed an additional fundamental growth limiting process where the mass of the individual SWCNT is determined by the individual catalyst volume. Calculation of the conversion rate of carbon atoms into CNTs per Fe atom is 2 × 102 atoms per second. This rate limiting process provides an important understanding where the larger diameter SWCNT would grow faster, and thus be more suited for mass production.

  5. A longitudinal study of alterations of hippocampal volumes and serum BDNF levels in association to atypical antipsychotics in a sample of first-episode patients with schizophrenia.

    Directory of Open Access Journals (Sweden)

    Emmanouil Rizos

    Full Text Available BACKGROUND: Schizophrenia is associated with structural and functional abnormalities of the hippocampus, which have been suggested to play an important role in the formation and emergence of schizophrenia syndrome. Patients with schizophrenia exhibit significant bilateral hippocampal volume reduction and progressive hippocampal volume decrease in first-episode patients with schizophrenia has been shown in many neuroimaging studies. Dysfunction of the neurotrophic system has been implicated in the pathophysiology of schizophrenia. The initiation of antipsychotic medication alters the levels of serum Brain Derived Neurotrophic Factor (BDNF levels. However it is unclear whether treatment with antipsychotics is associated with alterations of hippocampal volume and BDNF levels. METHODS: In the present longitudinal study we investigated the association between serum BDNF levels and hippocampal volumes in a sample of fourteen first-episode drug-naïve patients with schizophrenia (FEP. MRI scans, BDNF and clinical measurements were performed twice: at baseline before the initiation of antipsychotic treatment and 8 months later, while the patients were receiving monotherapy with second generation antipsychotics (SGAs. RESULTS: We found that left hippocampal volume was decreased (corrected left HV [t = 2.977, df = 13, p = .011] at follow-up; We also found that the higher the BDNF levels change the higher were the differences of corrected left hippocampus after 8 months of treatment with atypical antipsychotics (Pearson r = 0.597, p = 0.024. CONCLUSIONS: The association of BDNF with hippocampal volume alterations in schizophrenia merits further investigation and replication in larger longitudinal studies.

  6. Geological determination of the limits, area and volume of the geothermal reservoir of the Los Humeros geothermal field, Puebla, Mexico; Determinacion geologica de los limites, area y volumen del yacimiento geotermico de Los Humeros, Puebla, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Castillo Hernandez, Daniel [Gerencia de Proyectos Geotermoelectricos, Comision Federal de Electricidad, Morelia, Michoacan (Mexico)

    1999-08-01

    A geologic analysis to determine the limits, area and volume of the exploitable reservoir of the Los Humeros Geothermal Field, in Puebla, Mexico was carried out. We defined the structural boundaries, both at surface and at deep that seem to control the distribution of the fluids of high enthalpy and favor or limit the production of steam. With 40 wells drilled to date, an average thickness of the lithological producer Unit of 1 163 m has been estimated. A surface of 12.54 km{sup 2} was calculated, that with the estimated thickness, gives a volume of the reservoir of 14.6 km{sup 3}. We consider that there are two main production sectors in the Geothermal Field: The Central Collapse and The Mastaloya Corridor. [Spanish] Se realizo un analisis geologico para determinar los limites, area y volumen del yacimiento explotable del campo geotermico de Los Humeros en Puebla, Mexico. Se definen las barreras estructurales, tanto superficiales como del subsuelo, que controlan la distribucon de los fluidos de alta entalpia que favorecen o limitan la produccion de vapor. Con los 40 pozos perforados hasta la fecha, se estima un espesor promedio de la unidad productora de 1 163 m. Se calculo una superficie de 12.54 km{sup 2}, la que con el espesor mencionado, da un volumen del yacimiento de 14.6 km{sup 3}. Se plantea que dentro del campo existen dos sectores principales de produccion. El Colapso Central y el Corredor de Mastaloya.

  7. Computational Modeling to Limit the Impact Displays and Indicator Lights Have on Habitable Volume Operational Lighting Constraints

    Science.gov (United States)

    Clark, T. A.; Salazar, G. A.; Brainard, G. C.; Kolomenski, A.; Hanifin, J.; Schwin, B. M.

    2017-01-01

    NASA has demonstrated an interest in improving astronaut health and performance through the installment of a new lighting countermeasure on the International Space Station. The Solid State Lighting Assembly (SSLA) system is designed to positively influence astronaut health by providing a daily change to light spectrum to improve circadian entrainment. Unfortunately, existing NASA standards and requirements define ambient light level requirements for crew sleep and other tasks, yet the number of light-emitting diode (LED) indicators and displays within a habitable volume is currently uncontrolled. Because each of these light sources has its own unique spectral properties, the additive lighting environment ends up becoming something different from what was planned or researched. Restricting the use of displays and indicators is not a solution because these systems provide beneficial crew feedback.

  8. Aeroallergen analyses and their clinical relevance. II. Sampling by high-volume airsampler with immunochemical quantification versus Burkard pollen trap sampling with morphologic quantification

    DEFF Research Database (Denmark)

    Johnsen, C R; Weeke, E R; Nielsen, J

    1992-01-01

    , was analysed, and close correlations between the 2 sampling techniques were found (rs 0.5-0.8, p .... Pollen counts and immunochemical estimation were compared with the symptom score recordings of allergic persons for birch season 1989 and for grass seasons 1986, 1988, and 1989. A close correlation was found for both sampling techniques for the grass seasons in 1986 and 1989 (rs 0.51-0.61, p

  9. Quantification of myo-inositol, 1,5-anhydro- D-sorbitol, and D-chiro-inositol using high-performance liquid chromatography with electrochemical detection in very small volume clinical samples.

    Science.gov (United States)

    Schimpf, Karen J; Meek, Claudia C; Leff, Richard D; Phelps, Dale L; Schmitz, Daniel J; Cordle, Christopher T

    2015-11-01

    Inositol is a six-carbon sugar alcohol and is one of nine biologically significant isomers of hexahydroxycyclohexane. Myo-inositol is the primary biologically active form and is present in higher concentrations in the fetus and newborn than in adults. It is currently being examined for the prevention of retinopathy of prematurity in newborn preterm infants. A robust method for quantifying myo-inositol (MI), D-chiro-inositol (DCI) and 1,5-anhydro- D-sorbitol (ADS) in very small-volume (25 μL) urine, blood serum and/or plasma samples was developed. Using a multiple-column, multiple mobile phase liquid chromatographic system with electrochemical detection, the method was validated with respect to (a) selectivity, (b) accuracy/recovery, (c) precision/reproducibility, (d) sensitivity, (e) stability and (f) ruggedness. The standard curve was linear and ranged from 0.5 to 30 mg/L for each of the three analytes. Above-mentioned performance measures were within acceptable limits described in the Food and Drug Administration's Guidance for Industry: Bioanalytical Method Validation. The method was validated using blood serum and plasma collected using four common anticoagulants, and also by quantifying the accuracy and sensitivity of MI measured in simulated urine samples recovered from preterm infant diaper systems. The method performs satisfactorily measuring the three most common inositol isomers on 25 μL clinical samples of serum, plasma, milk, and/or urine. Similar performance is seen testing larger volume samples of infant formulas and infant formula ingredients. MI, ADS and DCI may be accurately tested in urine samples collected from five different preterm infant diapers if the urine volume is greater than 2-5 mL.

  10. A Full Automatic Device for Sampling Small Solution Volumes in Photometric Titration Procedure Based on Multicommuted Flow System

    Science.gov (United States)

    Borges, Sivanildo S.; Vieira, Gláucia P.; Reis, Boaventura F.

    2007-01-01

    In this work, an automatic device to deliver titrant solution into a titration chamber with the ability to determine the dispensed volume of solution, with good precision independent of both elapsed time and flow rate, is proposed. A glass tube maintained at the vertical position was employed as a container for the titrant solution. Electronic devices were coupled to the glass tube in order to control its filling with titrant solution, as well as the stepwise solution delivering into the titration chamber. The detection of the titration end point was performed employing a photometer designed using a green LED (λ=545 nm) and a phototransistor. The titration flow system comprised three-way solenoid valves, which were assembled to allow that the steps comprising the solution container loading and the titration run were carried out automatically. The device for the solution volume determination was designed employing an infrared LED (λ=930 nm) and a photodiode. When solution volume delivered from proposed device was within the range of 5 to 105 μl, a linear relationship (R = 0.999) between the delivered volumes and the generated potential difference was achieved. The usefulness of the proposed device was proved performing photometric titration of hydrochloric acid solution with a standardized sodium hydroxide solution and using phenolphthalein as an external indicator. The achieved results presented relative standard deviation of 1.5%. PMID:18317510

  11. Evaluation of sampling plans for in-service inspection of steam generator tubes. Volume 2, Comprehensive analytical and Monte Carlo simulation results for several sampling plans

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, R.J.; Heasler, P.G.; Baird, D.B. [Pacific Northwest Lab., Richland, WA (United States)

    1994-02-01

    This report summarizes the results of three previous studies to evaluate and compare the effectiveness of sampling plans for steam generator tube inspections. An analytical evaluation and Monte Carlo simulation techniques were the methods used to evaluate sampling plan performance. To test the performance of candidate sampling plans under a variety of conditions, ranges of inspection system reliability were considered along with different distributions of tube degradation. Results from the eddy current reliability studies performed with the retired-from-service Surry 2A steam generator were utilized to guide the selection of appropriate probability of detection and flaw sizing models for use in the analysis. Different distributions of tube degradation were selected to span the range of conditions that might exist in operating steam generators. The principal means of evaluating sampling performance was to determine the effectiveness of the sampling plan for detecting and plugging defective tubes. A summary of key results from the eddy current reliability studies is presented. The analytical and Monte Carlo simulation analyses are discussed along with a synopsis of key results and conclusions.

  12. Determination of Atto- to Femtogram Levels of Americium and Curium Isotopes in Large-Volume Urine Samples by Compact Accelerator Mass Spectrometry.

    Science.gov (United States)

    Dai, Xiongxin; Christl, Marcus; Kramer-Tremblay, Sheila; Synal, Hans-Arno

    2016-03-01

    Ultralow level analysis of actinides in urine samples may be required for dose assessment in the event of internal exposures to these radionuclides at nuclear facilities and nuclear power plants. A new bioassay method for analysis of sub-femtogram levels of Am and Cm in large-volume urine samples was developed. Americium and curium were co-precipitated with hydrous titanium oxide from the urine matrix and purified by column chromatography separation. After target preparation using mixed titanium/iron oxides, the final sample was measured by compact accelerator mass spectrometry. Urine samples spiked with known quantities of Am and Cm isotopes in the range of attogram to femtogram levels were measured for method evaluation. The results are in good agreement with the expected values, demonstrating the feasibility of compact accelerator mass spectrometry (AMS) for the determination of minor actinides at the levels of attogram/liter in urine samples to meet stringent sensitivity requirements for internal dosimetry assessment.

  13. Changes in brain volume and cognition in a randomized trial of exercise and social interaction in a community-based sample of non-demented Chinese elders.

    Science.gov (United States)

    Mortimer, James A; Ding, Ding; Borenstein, Amy R; DeCarli, Charles; Guo, Qihao; Wu, Yougui; Zhao, Qianhua; Chu, Shugang

    2012-01-01

    Physical exercise has been shown to increase brain volume and improve cognition in randomized trials of non-demented elderly. Although greater social engagement was found to reduce dementia risk in observational studies, randomized trials of social interventions have not been reported. A representative sample of 120 elderly from Shanghai, China was randomized to four groups (Tai Chi, Walking, Social Interaction, No Intervention) for 40 weeks. Two MRIs were obtained, one before the intervention period, the other after. A neuropsychological battery was administered at baseline, 20 weeks, and 40 weeks. Comparison of changes in brain volumes in intervention groups with the No Intervention group were assessed by t-tests. Time-intervention group interactions for neuropsychological measures were evaluated with repeated-measures mixed models. Compared to the No Intervention group, significant increases in brain volume were seen in the Tai Chi and Social Intervention groups (p brain volume and improvements in cognition with a largely non-aerobic exercise (Tai Chi). In addition, intellectual stimulation through social interaction was associated with increases in brain volume as well as with some cognitive improvements.

  14. Total and regional brain volumes in a population-based normative sample from 4 to 18 years: the NIH MRI Study of Normal Brain Development.

    Science.gov (United States)

    2012-01-01

    Using a population-based sampling strategy, the National Institutes of Health (NIH) Magnetic Resonance Imaging Study of Normal Brain Development compiled a longitudinal normative reference database of neuroimaging and correlated clinical/behavioral data from a demographically representative sample of healthy children and adolescents aged newborn through early adulthood. The present paper reports brain volume data for 325 children, ages 4.5-18 years, from the first cross-sectional time point. Measures included volumes of whole-brain gray matter (GM) and white matter (WM), left and right lateral ventricles, frontal, temporal, parietal and occipital lobe GM and WM, subcortical GM (thalamus, caudate, putamen, and globus pallidus), cerebellum, and brainstem. Associations with cross-sectional age, sex, family income, parental education, and body mass index (BMI) were evaluated. Key observations are: 1) age-related decreases in lobar GM most prominent in parietal and occipital cortex; 2) age-related increases in lobar WM, greatest in occipital, followed by the temporal lobe; 3) age-related trajectories predominantly curvilinear in females, but linear in males; and 4) small systematic associations of brain tissue volumes with BMI but not with IQ, family income, or parental education. These findings constitute a normative reference on regional brain volumes in children and adolescents.

  15. Computational Modeling to Limit the Impact Displays and Indicator Lights Have on Habitable Volume Operational Lighting Constraints

    Science.gov (United States)

    Clark, T. A.; Brainard, G.; Salazar, G.; Johnston, S.; Schwing, B.; Litaker, H.; Kolomenski, A.; Venus, D.; Tran, K.; Hanifin, J.; Adolf, J.

    2017-01-01

    NASA has demonstrated an interest in improving astronaut health and performance through the installment of a new lighting countermeasure on the International Space Station. The Solid State Lighting Assembly (SSLA) system is designed to positively influence astronaut health by providing a daily change to light spectrum to improve circadian entrainment. Unfortunately, existing NASA standards and requirements define ambient light level requirements for crew sleep and other tasks, yet the number of light-emitting diode (LED) indicators and displays within a habitable volume is currently uncontrolled. Because each of these light sources has its own unique spectral properties, the additive lighting environment ends up becoming something different from what was planned or researched. Restricting the use of displays and indicators is not a solution because these systems provide beneficial feedback to the crew. The research team for this grant used computer-based computational modeling and real-world lighting mockups to document the impact that light sources other than the ambient lighting system contribute to the ambient spectral lighting environment. In particular, the team was focused on understanding the impacts of long-term tasks located in front of avionics or computer displays. The team also wanted to understand options for mitigating the changes to the ambient light spectrum in the interest of maintaining the performance of a lighting countermeasure. The project utilized a variety of physical and computer-based simulations to determine direct relationships between system implementation and light spectrum. Using real-world data, computer models were built in the commercially available optics analysis software Zemax Optics Studio(c). The team also built a mockup test facility that had the same volume and configuration as one of the Zemax models. The team collected over 1200 spectral irradiance measurements, each representing a different configuration of the mockup

  16. [Macrokinetic basis for the model of microbial growth in a limited volume under constant conditions with a single leading substrate].

    Science.gov (United States)

    Gendugov, V M; Glazunov, G P

    2013-01-01

    Within the framework of the macrokinetic approach and continuum and chemical/biochemical gross reaction conceptions, an equation describing the complete dynamics of microbial growth and decline as function of a variable concentration of the leading substrate was deduced. This equation allows us to distinguish quantitatively and qualitatively the stages of microbial growth and the intervals of microbial tolerance to the initial concentration of the leading substrate. Adequacy of the model was confirmed by comparison with experimental dynamics of aerobic microorganisms in the samples of groundwater collected from a region polluted with uranium.

  17. Increased levels of HIV RNA detected in samples with viral loads close to the detection limit collected in Plasma Preparation Tubes (PPT).

    Science.gov (United States)

    Griffith, Brigitte P; Mayo, Donald R

    2006-02-01

    The accurate and reliable quantification of HIV RNA is an essential part of the management of HIV infected individuals, and elucidation of factors that may affect HIV RNA measurements, such as the use of Vacutainer Plasma Preparation Tubes (PPT), is crucial. The objective of this study was to determine if plasma samples with viral loads close to the lower limit of the dynamic range of the assay collected in PPT tubes had increased levels of HIV RNA as compared to samples collected in standard EDTA tubes. HIV RNA levels were compared in 112 paired plasma samples collected in PPT and standard EDTA tubes. All samples had been frozen prior to testing. Discrepancies between PPT and EDTA tubes did not occur for samples with high viral loads. However, in samples with viral loads close to the lower limit of the dynamic range, levels of HIV RNA detected were higher in a large proportion of PPT as compared to the corresponding EDTA plasma samples. Forty percent of plasma pairs had no detectable HIV RNA in the EDTA aliquot, but had low levels of HIV RNA in the corresponding PPT aliquot. This prospective study underlines the need for cautious interpretation of small transient viral load changes in samples with values close to the detection limit.

  18. A follow-up urine sample has limited value after treatment for urinary tract infection in children

    DEFF Research Database (Denmark)

    Lytzen, Rebekka; Kaalund-Jørgensen, Kristine; Ahmed, Akhlaq

    2015-01-01

    INTRODUCTION: A routine follow-up urine sample (FUS) in the form of a midstream urine sample (MSU) is recommended after treatment for urinary tract infection (UTI) according to the Danish Paediatric Society (DPS) and "Lægehåndbogen" published by Danish Regions. We studied the effect of FUS...

  19. A follow-up urine sample has limited value after treatment for urinary tract infection in children

    DEFF Research Database (Denmark)

    Lytzen, Rebekka; Kaalund-Jørgensen, Kristine; Ahmed, Akhlaq

    2015-01-01

    INTRODUCTION: A routine follow-up urine sample (FUS) in the form of a midstream urine sample (MSU) is recommended after treatment for urinary tract infection (UTI) according to the Danish Paediatric Society (DPS) and "Lægehåndbogen" published by Danish Regions. We studied the effect of FUS...

  20. [Determination of short-chain chlorinated paraffins in ambient air using high-volume sampling combined with high resolutimi gas chromatography-electron capture negative ion-low resolution mass spectrometry].

    Science.gov (United States)

    Shi, Loimeng; Gao, Yuan; Hou, Xiaohong; Zhang, Haijun; Zhang, Yichi; Chen, Jiping

    2016-02-01

    An analytical method for quantifying short-chain chlorinated paraffins (SCCPs) in ambient air using high-volume sampling combined with high resolution gas chromatography-electron capture negative ion-low resolution mass spectrometry ( HRGC-ECNI-LRMS) was developed. An acidified silica gel column and a basic alumina column were used to optimize the cleanup procedures. The results showed a good linearity (R2>0. 99) between the total response factors and the degree of chlorination of SCCPs in the content range of 58. 1%-63. 3%. The limits of detection (S/N ≥3) and the limits of quantification (S/N ≥ 10) were 4. 2 and 12 µg, respectively. The method detection limit (MDL) for SCCPs was 0. 34 ng/m3 (n = 7). The recoveries of SCCPs in air samples were in the range of 81. 9% to 94. 2%. It is demonstrated that the method is suitable for the quantitative analysis of SCCPs in air samples.

  1. [An evaluation of sampling design for estimating an epidemiologic volume of diabetes and for assessing present status of its control in Korea].

    Science.gov (United States)

    Lee, Ji-Sung; Kim, Jaiyong; Baik, Sei-Hyun; Park, Ie-Byung; Lee, Juneyoung

    2009-03-01

    An appropriate sampling strategy for estimating an epidemiologic volume of diabetes has been evaluated through a simulation. We analyzed about 250 million medical insurance claims data submitted to the Health Insurance Review & Assessment Service with diabetes as principal or subsequent diagnoses, more than or equal to once per year, in 2003. The database was re-constructed to a 'patient-hospital profile' that had 3,676,164 cases, and then to a 'patient profile' that consisted of 2,412,082 observations. The patient profile data was then used to test the validity of a proposed sampling frame and methods of sampling to develop diabetic-related epidemiologic indices. Simulation study showed that a use of a stratified two-stage cluster sampling design with a total sample size of 4,000 will provide an estimate of 57.04% (95% prediction range, 49.83 - 64.24%) for a treatment prescription rate of diabetes. The proposed sampling design consists, at first, stratifying the area of the nation into "metropolitan/city/county" and the types of hospital into "tertiary/secondary/primary/clinic" with a proportion of 5:10:10:75. Hospitals were then randomly selected within the strata as a primary sampling unit, followed by a random selection of patients within the hospitals as a secondly sampling unit. The difference between the estimate and the parameter value was projected to be less than 0.3%. The sampling scheme proposed will be applied to a subsequent nationwide field survey not only for estimating the epidemiologic volume of diabetes but also for assessing the present status of nationwide diabetes control.

  2. A study of toxic emissions from a coal-fired power plant utilizing an ESP/Wet FGD system. Volume 1, Sampling, results, and special topics: Final report

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    This was one of a group of assessments of toxic emissions from coal-fired power plants, conducted for DOE-PETC in 1993 as mandated by the 1990 Clean Air Act. It is organized into 2 volumes; Volume 1 describes the sampling effort, presents the concentration data on toxic chemicals in several power plant streams, and reports the results of evaluations and calculations. The study involved solid, liquid, and gaseous samples from input, output, and process streams at Coal Creek Station Unit No. 1, Underwood, North Dakota (1100 MW mine-mouth plant burning lignite from the Falkirk mine located adjacent to the plant). This plant had an electrostatic precipitator and a wet scrubber flue gas desulfurization unit. Measurements were conducted on June 21--24, 26, and 27, 1993; chemicals measured were 6 major and 16 trace elements (including Hg, Cr, Cd, Pb, Se, As, Be, Ni), acids and corresponding anions (HCl, HF, chloride, fluoride, phosphate, sulfate), ammonia and cyanide, elemental C, radionuclides, VOCs, semivolatiles (incl. PAH, polychlorinated dioxins, furans), and aldehydes. Volume 2: Appendices includes process data log sheets, field sampling data sheets, uncertainty calculations, and quality assurance results.

  3. Determination of ethyl glucuronide in hair samples of Chinese people by protein precipitation (PPT) and large volume injection-gas chromatography-tandem mass spectrometry (LVI-GC/MS/MS).

    Science.gov (United States)

    Shi, Yan; Shen, Baohua; Xiang, Ping; Yan, Hui; Shen, Min

    2010-11-15

    Ethyl glucuronide (EtG) has been shown to be a suitable marker of excessive alcohol consumption. Determination of EtG in hair samples may help to differentiate social drinkers from alcoholics, and this testing can be widely used in forensic science, treatment programs, workplaces, military bases as well as driving ability test to provide legal proof of drinking. A method for determination of EtG in hair samples using large volume injection-gas chromatography-tandem mass spectrometry (LVI-GC/MS/MS) was developed and validated. Hair samples (in 1 mL deionized water) were ultrasonicated for 1h and incubated overnight; these samples were then deproteinated to remove impurities and derivatisated with 15 μL of pyridine and 30 μL of BSTFA. EtG was detected using GC/MS/MS in multiple-reaction monitoring mode. This method exhibited good linearity: y=0.0036 x+0.0437, R²=0.9993, the limit of detection and the limit of quantification were 5 pg/mg and 10 pg/mg, respectively. The extraction recoveries were more than 60%, and the inter-day and intra-day relative standard deviations (RSD) were less than 15%. This method has been applied to the analysis of EtG in hair samples from 21 Chinese subjects. The results for samples obtained from all of those who were teetotallers were negative, and the results for the other 15 samples ranged from 10 to 78 pg/mg, except for one negative sample. These data are the basis for interpretation of alcohol abuse. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Mechanical properties of the samples produced by volume powder cladding of stainless steel using a continuous fiber laser

    Science.gov (United States)

    Bykovskiy, D. P.; Petrovskiy, V. N.; Mironov, V. D.; Osintsev, A. V.; Ochkov, K. Yu

    2016-09-01

    Samples for tensile tests were manufactured by using one of the additive technologies - direct laser material deposition. Investigations were carried out at the facility Huffman HC-205 equipped with a fiber laser with a power up to 3.5 kW. Various strategies of layering metallic powder of stainless steel 316L were considered to optimize the modes of constructing the samples. We measured the stress-strain state of the produced samples by the method of digital image correlation. It is found that the nominal tensile strength of the samples produced by the direct growing using laser powder of 316L steel is of high level - 767 MPa.

  5. On-line SPE sample treatment as a tool for method automatization and detection limits reduction: Quantification of 25-hydroxyvitamin D3/D2.

    Science.gov (United States)

    Palaiogiannis, Dimitrios; Bekou, Evangelia; Pazaitou-Panayiotou, Kalliopi; Samanidou, Victoria; Tsakalof, Andreas

    2017-02-01

    The development and approbation of new, automated UHPLC-DAD method for the quantification of 25-hydroxyvitamin D3/D2 (25OH-D3/D2) metabolites in plasma/serum for the evaluation of patient's vitamin D status are presented. The method was developed on the Ultimate 3000 UHPLC dual gradient system supplied with the on-line SPE-concentration column coupled through six port switching valve to analytical column. This configuration and materials selected enable large volume sample injection (500μL) and on-line sample preconcentration, clean up and subsequent selective metabolites transfer onto the analytical column. The new method abrogates main conventional time consuming and error source off-line steps of analysis and thus simplifies analysis. The large volume injection increases the sensitivity of instrumental analysis by about ten-fold on-line pre-concentration of metabolites. The instrument response is linear (R>0.99) in the investigated concentration range 10-100ngmL(-1) which covers all the possible vitamin D status from serious deficiency (D3)=0.94ngmL(-1) and LOD (25OH-D2)=2.4ngmL(-1). The method performance was assessed with the use of certified reference samples and perfect agreement between certified and measured values is demonstrated. The method was applied to human samples previously analyzed for total vitamin D by Competitive Protein-binding assay and findings of the two methods are compared.

  6. Distribution of dead wood volume and mass in mediterranean Fagus sylvatica L. forests in Northern Iberian Peninsula. Implications for field sampling inventory

    Directory of Open Access Journals (Sweden)

    Celia Herrero

    2016-12-01

    Full Text Available Aim of study: The aim of this study was to 1 estimate the amount of dead wood in managed beech (Fagus sylvatica L. stands in northern Iberian Peninsula and 2 evaluate the most appropriate volume equation and the optimal transect length for sampling downed wood. Area of study: The study area is the Aralar Forest in Navarra (Northern Iberian Peninsula. Material and methods: The amount of dead wood by component (downed logs, snags, stumps and fine woody debris was inventoried in 51 plots across a chronosequence of stand ages (0-120 years old. Main results: The average volume and biomass of dead wood was 24.43 m3 ha-1 and 7.65 Mg ha-1, respectively. This amount changed with stand development stage [17.14 m3 ha-1 in seedling stage; 34.09 m3 ha-1 inpole stage; 22.54 m3 ha-1 in mature stage and 24.27 m3 ha-1 in regular stand in regeneration stage], although the differences were not statistically significant for coarse woody debris. However, forest management influenced the amount of dead wood, because the proportion of mass in the different components and the decay stage depended on time since last thinning. The formula based on intersection diameter resulted on the smallest coefficient of variation out of seven log-volume formulae. Thus, the intersection diameter is the preferred method because it gives unbiased estimates, has the greatest precision and is the easiest to implement in the field. Research highlights: The amount of dead wood, and in particular snags, was significantly lower than that in reserved forests. Results of this study showed that sampling effort should be directed towards increasing the number of transects, instead of increasing transect length or collecting additional piece diameters that do not increase the accuracy or precision of DWM volume estimation. Keywords: snags; downed logs; stumps; fine woody debris; beech; line intersect sampling.

  7. DNA isolation protocols affect the detection limit of PCR approaches of bacteria in samples from the human gastrointestinal tract

    NARCIS (Netherlands)

    Zoetendal, E.G.; Ben-Amor, K.; Akkermans, A.D.L.; Abee, T.; Vos, de W.M.

    2001-01-01

    A major concern in molecular ecological studies is the lysis efficiency of different bacteria in a complex ecosystem. We used a PCR-based 16S rDNA approach to determine the effect of two DNA isolation protocols (i.e. the bead beating and Triton-X100 method) on the detection limit of seven feces-asso

  8. 网络内容分析法抽样的局限性及对策%Sampling Limitations and Its Countermeasures in Web Content Analysis Method

    Institute of Scientific and Technical Information of China (English)

    曾照云; 程安广

    2012-01-01

    This paper holds that the limitations in sampling frame establishment mainly lay in network database, website / webpage directory listings, search engine, etc. This results in sampling frame generating deviation easily or its sample being not representative. The main limitations in sampling method lay in two aspects: more non-probability sampling was used but had significant deficiencies in the sampling error estimating; the application of probability sampling takes on a downward trend. This paper proposed combination of a variety of methods in establishing sampling frame, and using meta-search engines to collect information, and also proposed to use probability sampling as much as possible in sampling method establishment, among them stratified sampling and multistage sampling is feasible.%认为抽样框确立方式的局限性主要来自网络数据库、网站/网页目录列表、搜索引擎等方面,导致抽样框容易产生偏差或样本不具有代表性;抽样方法的局限性主要是非概率抽样应用较多却在估计抽样误差方面有明显不足,概率抽样的应用有下降趋势。建议结合使用多种方式确立抽样框,利用元搜索引擎搜集信息;而抽样方法的确立应尽量使用概率抽样,其中分层抽样和多阶段抽样是比较可行的。

  9. Evaluation of selected-ion flow-tube mass spectrometry for the measurement of ethanol, methanol and isopropanol in physiological fluids: effect of osmolality and sample volume.

    Science.gov (United States)

    Rowbottom, Lynn; Workman, Clive; Roberts, Norman B

    2009-09-01

    Selected-ion flow-tube mass spectrometry (SIFT-MS) is particularly suited for the analysis of volatile low molecular weight compounds. We have evaluated this technique for the assay of different alcohols in aqueous solutions, including blood plasma, and in particular whether the osmolality or sample volume affected vapourisation. Solutions of three different alcohols (methanol, ethanol and isopropanol) ranging from 0.005 to 50 mmol/L were prepared in deionised water (0 milliosmol), phosphate-buffered saline (690 mOsm), isotonic saline (294 mOsm) and plasma (296 mOsm). The vapour above the sample (50 to 1000 microL) contained in air-tight tubes at 37 degrees C was aspirated into the instrument. The outputs for ethanol, methanol and isopropanol were linear over the concentration range and independent of the sample volume and relatively independent of the osmolar concentration. SIFT-MS can reliably and accurately measure common alcohols in the headspace above aqueous solutions, including serum/plasma. This novel application of SIFT-MS is easy to follow, requires no sample preparation and the wide dynamic range will facilitate measurement of alcohols present from normal metabolism as well as when taken in excess or in accidental poisoning.

  10. Probabilistic Requirements (Partial) Verification Methods Best Practices Improvement. Variables Acceptance Sampling Calculators: Derivations and Verification of Plans. Volume 1

    Science.gov (United States)

    Johnson, Kenneth L.; White, K, Preston, Jr.

    2012-01-01

    The NASA Engineering and Safety Center was requested to improve on the Best Practices document produced for the NESC assessment, Verification of Probabilistic Requirements for the Constellation Program, by giving a recommended procedure for using acceptance sampling by variables techniques. This recommended procedure would be used as an alternative to the potentially resource-intensive acceptance sampling by attributes method given in the document. This document contains the outcome of the assessment.

  11. A Fast Algorithm to Compute Band-Limited Interpolation from Unevenly Spaced Sampled Data Using K-Nearest Neighbor Search

    NARCIS (Netherlands)

    Lidicky, L.; Hoogeboom, P.

    2006-01-01

    This paper presents an algorithm that performs one or two-dimensional interpolation under certain conditions. It is optimized for speed by means of taking advantage of some special cases which occur in SAR signal processing. In SAR processing, one needs to interpolate data from non-uniformly sampled

  12. An alternative method of OBT measurement for the limited quantity of environmental samples using a combustion bomb.

    Science.gov (United States)

    Kim, Sang Bog; Stuart, Marilyne

    2013-12-01

    The measurement of organically bound tritium (OBT) in environmental samples is much more difficult than the measurement of tritiated water (HTO). This study describes an alternative method for OBT determination in plant materials in which tritium-free polyethylene beads are added to the plant sample prior to combustion in a combustion bomb. It is not always possible to collect large enough amounts of some plants (e.g. algae, plankton, grass) within a specific area or specific period. Excellent water recovery is achieved when dry plant materials are combusted with polyethylene beads. When Ultima Gold AB is used as the scintillation cocktail, it is possible to measure the combustion water directly without distillation. Correction factors were derived for the plants used in the study to account for the dilution of the combustion water due to addition of the polyethylene beads. The alternative method has a number of advantages, including an increased yield of combustion water for liquid scintillation counting, less color quenching, reduced sample size and decreased analysis time. Finally, accuracy tests comparing results of the conventional method with those of the alternative method were carried out using environmental samples.

  13. Early treatment volume reduction rate as a prognostic factor in patients treated with chemoradiotherapy for limited stage small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joo Hwan; Lee, Jeong Shin; Lee, Chang Geol; Cho, Jae Ho [Dept. of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul (Korea, Republic of); Choi, Jin Hyun; Kim, Jun Won [Dept. of Radiation Oncology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2015-06-15

    To investigate the relationship between early treatment response to definitive chemoradiotherapy (CRT) and survival outcome in patients with limited stage small cell lung cancer (LS-SCLC). We retrospectively reviewed 47 patients with LS-SCLC who received definitive CRT between January 2009 and December 2012. Patients were treated with systemic chemotherapy regimen of etoposide/carboplatin (n = 15) or etoposide/cisplatin (n = 32) and concurrent thoracic radiotherapy at a median dose of 54 Gy (range, 46 to 64 Gy). Early treatment volume reduction rate (ETVRR) was defined as the percentage change in gross tumor volume between diagnostic computed tomography (CT) and simulation CT for adaptive RT planning and was used as a parameter for early treatment response. The median dose at adaptive RT planning was 36 Gy (range, 30 to 43 Gy), and adaptive CT was performed in 30 patients (63.8%). With a median follow-up of 27.7 months (range, 5.9 to 75.8 months), the 2-year locoregional progression-free survival (LRPFS) and overall survival (OS) rates were 74.2% and 56.5%, respectively. The mean diagnostic and adaptive gross tumor volumes were 117.9 mL (range, 5.9 to 447 mL) and 36.8 mL (range, 0.3 to 230.6 mL), respectively. The median ETVRR was 71.4% (range, 30 to 97.6%) and the ETVRR >45% group showed significantly better OS (p < 0.0001) and LRPFS (p = 0.009) than the other group. ETVRR as a parameter for early treatment response may be a useful prognostic factor to predict treatment outcome in LS-SCLC patients treated with CRT.

  14. A finite-volume fast diffusion-limited aggregation model for predicting the coagulation rate of mixed low-ionized system

    Science.gov (United States)

    Feng, Yu; Wang, Guang; Ruan, Leidan; Du, Ai

    2017-03-01

    Accompanied with the changing of coagulation time, the micro-structure of aerogel can be controlled by adding Polyacrylic acid (PAA) into sol system. We simulate the process of particles aggregation contains attracting molecular chains based on diffusion-limited cluster aggregation (DLCA). Compared with the normal coagulation system, the coagulation rate of the system that contains attracting chains are sped up first and then slowed down. The results of the stimulation point out that the interaction between particles and chains not only accelerates the motion of particles, but also separates the region and constrains the clusters' motion. These two effects are coexisting but the attracting interaction play a dominant role in the early state while the volume of chains has a dramatic influence on cluster's motion in late states.

  15. Possibilities and limitations of the ART-Sample algorithm for reconstruction of 3D temperature fields and the influence of opaque obstacles.

    Science.gov (United States)

    Li, Yuanyang; Herman, Cila

    2013-07-01

    The need for the measurement of complex, unsteady, three-dimensional (3D) temperature distributions arises in a variety of engineering applications, and tomographic techniques are applied to accomplish this goal. Holographic interferometry (HI), one of the optical methods used for visualizing temperature fields, combined with tomographic reconstruction techniques requires multi-directional interferometric data to recover the 3D information. However, the presence of opaque obstacles (such as solid objects in the flow field and heaters) in the measurement volume, prevents the probing light beams from traversing the entire measurement volume. As a consequence, information on the average value of the field variable will be lost in regions located in the shade of the obstacle. The capability of the ART-Sample tomographic reconstruction method to recover 3D temperature distributions both in unobstructed temperature fields and in the presence of opaque obstacles is discussed in this paper. A computer code for tomographic reconstruction of 3D temperature fields from 2D projections was developed. In the paper, the reconstruction accuracy is discussed quantitatively both without and with obstacles in the measurement volume for a set of phantom functions mimicking realistic temperature distributions. The reconstruction performance is optimized while minimizing the number of irradiation directions (experimental hardware requirements) and computational effort. For the smooth temperature field both with and without obstacles, the reconstructions produced by this algorithm are good, both visually and using quantitative criteria. The results suggest that the location and the size of the obstacle and the number of viewing directions will affect the reconstruction of the temperature field. When the best performance parameters of the ART-Sample algorithm identified in this paper are used to reconstruct the 3D temperature field, the 3D reconstructions with and without obstacle are

  16. The distribution of dust in Sb's and Sc's : K-band infrared imaging of a diameter limited sample of 37 galaxies

    NARCIS (Netherlands)

    Peletier, R. F.; Valentijn, E. A.; Moorwood, A. F. M.; Freudling, W.

    1994-01-01

    We present deep infrared K-band surface photometry for a diameter-limited sample of normal Sb and Sc galaxies. In addition, surface brightness, optical and optical-infrared colors and isophote-shapes have been obtained from the ESO-LV B and R photographic images of these galaxies. For each galaxy we

  17. The acetylene inhibition technique to determine total denitrification (N2 + N2O losses from soil samples: potentials and limitations

    Directory of Open Access Journals (Sweden)

    A. Neftel

    2012-03-01

    Full Text Available The loss of N2 from intensively managed agro-ecosystems is an important part of the N budget. The monitoring of N2 emissions at the field scale is impossible due to the high atmospheric background of 78%, which precludes the measurement of fluxes. The acetylene (C2H2 inhibition technique is a rather simple, albeit imperfect, method to determine N2 losses from entire soil cores. Despites serious limitations it is one among very few methodological options to estimate total denitrification at high temporal resolution and on small spatial scale, with limited workload and costs involved. A laboratory system with two different detection systems (photoacoustic IR spectroscopy and gas chromatography is presented, which allowed parallel measurements of up to 7 intact soil cores in air-tight glass tubes in a temperature controlled cabinet (adjusted to field conditions with an automated C2H2 injection. A survey of total denitrification losses (N2 + N2O over 1.5 yr in soil from an intensively managed, cut grassland system in central Switzerland showed a lower bound loss in the range of 6 to 25 kg N ha−1 yr−1 (3–13% of added N, roughly 3.4 times higher than the N2O loss. However, several drawbacks of the C2H2 inhibition technique preclude a more precise determination of the total denitrification loss.

  18. A follow-up urine sample has limited value after treatment for urinary tract infection in children

    DEFF Research Database (Denmark)

    Lytzen, Rebekka; Kaalund-Jørgensen, Kristine; Ahmed, Akhlaq;

    2015-01-01

    INTRODUCTION: A routine follow-up urine sample (FUS) in the form of a midstream urine sample (MSU) is recommended after treatment for urinary tract infection (UTI) according to the Danish Paediatric Society (DPS) and "Lægehåndbogen" published by Danish Regions. We studied the effect of FUS...... with a focus on patients without symptoms at the time of FUS. METHODS: Consecutive patients below 16.0 years treated for upper or lower UTI from 1 January 2009 to 31 December 2009 at Hvidovre Hospital in accordance with the guidelines of the department and the DPS. All patients were asked to provide a FUS...... within 21 days. RESULTS: A total of 87 patients were treated for upper UTI: 59 girls and 28 boys, the median age was 1.1 year (range: 0.1-15.6 years); and 42 girls were treated for lower UTI, their median age was 8.2 years (range: 2.5-15.3 years). After treatment, the risk of a UTI was 0% (0/87) after...

  19. A limited survey of aflatoxin B1 contamination in Indonesian palm kernel cake and copra meal sampled from batches.

    Science.gov (United States)

    Pranowo, Deni; Nuryono; Agus, Ali; Wedhastri, Sri; Reiter, Elisabeth Viktoria; Razzazi-Fazeli, Ebrahim; Zentek, Jürgen

    2013-08-01

    Samples from large (100-200 tons) batches of palm kernel cake (PKC, n = 20) and copra meal (CM, n = 13) were collected at production facilities of four Indonesian feed mill manufacturers and analysed for aflatoxin B1 (AFB1) by ELISA. Recoveries using spiked samples ranged from 86 to 113%, with relative standard deviations of <9% (PKC) and <6% (CM). All batches were positive for AFB1: in PKC, at levels of 5.8-93.1 μg/kg (mean 49 μg/kg), and in CM, at levels of 1.1-147 μg/kg (mean 38.1 μg/kg). AFB1 levels were, in most batches, below the maximum level (100 μg/kg) recommended by the National Standardisation Agency, Republic of Indonesia. However, about half of the batches exceeded both the European Union and USA regulations for AFB1 in animal feed. In conclusion, serious efforts are necessary to control production, storage and shipment of palm kernel cake and copra meal for feed purposes, and clearly not only for products intended for export but also to reduce AFB1 levels in domestic Indonesian feed.

  20. Green Ocean Amazon 2014/15 High-Volume Filter Sampling: Atmospheric Particulate Matter of an Amazon Tropical City and its Relationship to Population Health Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Machado, C. M. [Federal Univ. of Amazonas (Brazil); Santos, Erickson O. [Federal Univ. of Amazonas (Brazil); Fernandes, Karenn S. [Federal Univ. of Amazonas (Brazil); Neto, J. L. [Federal Univ. of Amazonas (Brazil); Souza, Rodrigo A. [Univ. of the State of Amazonas (Brazil)

    2016-08-01

    Manaus, the capital of the Brazilian state of Amazonas, is developing very rapidly. Its pollution plume contains aerosols from fossil fuel combustion mainly due to vehicular emission, industrial activity, and a thermal power plant. Soil resuspension is probably a secondary source of atmospheric particles. The plume transports from Manaus to the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility ARM site at Manacapuru urban pollutants as well as pollutants from pottery factories along the route of the plume. Considering the effects of particulate matter on health, atmospheric particulate matter was evaluated at this site as part of the ARM Facility’s Green Ocean Amazon 2014/15 (GoAmazon 2014/15) field campaign. Aerosol or particulate matter (PM) is typically defined by size, with the smaller particles having more health impact. Total suspended particulate (TSP) are particles smaller than 100 μm; particles smaller than 2.5 μm are called PM2.5. In this work, the PM2.5 levels were obtained from March to December of 2015, totaling 34 samples and TSP levels from October to December of 2015, totaling 17 samples. Sampling was conducted with PM2.5 and TSP high-volume samplers using quartz filters (Figure 1). Filters were stored during 24 hours in a room with temperature (21,1ºC) and humidity (44,3 %) control, in order to do gravimetric analyses by weighing before and after sampling. This procedure followed the recommendations of the Brazilian Association for Technical Standards local norm (NBR 9547:1997). Mass concentrations of particulate matter were obtained from the ratio between the weighted sample and the volume of air collected. Defining a relationship between particulate matter (PM2.5 and TSP) and respiratory diseases of the local population is an important goal of this project, since no information exists on that topic.

  1. Application of highly sensitive saturation labeling to the analysis of differential protein expression in infected ticks from limited samples

    Directory of Open Access Journals (Sweden)

    Villar Margarita

    2010-08-01

    Full Text Available Abstract Background Ticks are vectors of pathogens that affect human and animal health worldwide. Proteomics and genomics studies of infected ticks are required to understand tick-pathogen interactions and identify potential vaccine antigens to control pathogen transmission. One of the limitations for proteomics research in ticks is the amount of protein that can be obtained from these organisms. In the work reported here, individual naturally-infected and uninfected Rhipicephalus spp. ticks were processed using a method that permits simultaneous extraction of DNA, RNA and proteins. This approach allowed using DNA to determine pathogen infection, protein for proteomics studies and RNA to characterize mRNA levels for some of the differentially expressed proteins. Differential protein expression in response to natural infection with different pathogens was characterized by two-dimensional (2-D differential in gel electrophoresis (DIGE saturation labeling in combination with mass spectrometry analysis. To our knowledge, this is the first report of the application of DIGE saturation labeling to study tick proteins. Results Questing and feeding Rhipicephalus spp. adult ticks were collected in 27 farms located in different Sicilian regions. From 300 collected ticks, only 16 were found to be infected: R. sanguineus with Rickettsia conorii and Ehrlichia canis; R. bursa with Theileria annulata; and R. turanicus with Anaplasma ovis. The proteomic analysis conducted from a limited amount of proteins allowed the identification of host, pathogen and tick proteins differentially expressed as a consequence of infection. Conclusion These results showed that DIGE saturation labeling is a powerful technology for proteomics studies in small number of ticks and provided new information about the effect of pathogen infection in ticks.

  2. Separation optimization of long porous-layer open-tubular columns for nano-LC-MS of limited proteomic samples.

    Science.gov (United States)

    Rogeberg, Magnus; Vehus, Tore; Grutle, Lene; Greibrokk, Tyge; Wilson, Steven Ray; Lundanes, Elsa

    2013-09-01

    The single-run resolving power of current 10 μm id porous-layer open-tubular (PLOT) columns has been optimized. The columns studied had a poly(styrene-co-divinylbenzene) porous layer (~0.75 μm thickness). In contrast to many previous studies that have employed complex plumbing or compromising set-ups, SPE-PLOT-LC-MS was assembled without the use of additional hardware/noncommercial parts, additional valves or sample splitting. A comprehensive study of various flow rates, gradient times, and column length combinations was undertaken. Maximum resolution for LC conditions or long silica monolith nanocolumns. Nearly 500 proteins (1958 peptides) could be identified in just one single injection of an extract corresponding to 1000 BxPC3 beta catenin (-/-) cells, and ~1200 and 2500 proteins in extracts of 10,000 and 100,000 cells, respectively, allowing detection of central members and regulators of the Wnt signaling pathway.

  3. Nanoprobe NAPPA Arrays for the Nanoconductimetric Analysis of Ultra-Low-Volume Protein Samples Using Piezoelectric Liquid Dispensing Technology

    Directory of Open Access Journals (Sweden)

    Eugenia Pechkova

    2015-03-01

    Full Text Available In the last years, the evolution and the advances of the nanobiotechnologies applied to the systematic study of proteins, namely proteomics, both structural and functional, and specifically the development of more sophisticated and largescale protein arrays, have enabled scientists to investigate protein interactions and functions with an unforeseeable precision and wealth of details. Here, we present a further advancement of our previously introduced and described Nucleic Acid Programmable Protein Arrays (NAPPA-based nanoconductometric sensor. We coupled Quartz Crystal Microbalance with Dissipation factor Monitoring (QCM_D with piezoelectric inkjet printing technology (namely, the newly developed ActivePipette, which enables to significantly reduce the volume of probe required for genes/proteins arrays. We performed a negative control (with master mix, or MM and a positive control (MM_p53 plus MDM2. We performed this experiment both in static and in flow, computing the apparent dissociation constant of p53-MDM2 complex (130 nM, in excellent agreement with the published literature. We compared the results obtained with the ActivePipette printing and dispensing technology vs. pin spotting. Without the ActivePipette, after MDM2 addition the shift in frequency (Δf was 7575 Hz and the corresponding adsorbed mass was 32.9 μg. With the ActivePipette technology, after MDM2 addition Δf was 7740 Hz and the corresponding adsorbed mass was 33.6 μg. With this experiment, we confirmed the sensing potential of our device, being able to discriminate each gene and protein as well as their interactions, showing for each one of them a unique conductance curve. Moreover, we obtained a better yield with the ActivePipette technology.

  4. Determination of selected polycyclic aromatic compounds in particulate matter: a validation study of an agitation extraction method for samples with low mass loadings using reduced volumes

    Science.gov (United States)

    García-Alonso, S.; Pérez-Pastor, R. M.; Archilla-Prat, V.; Rodríguez-Maroto, J.; Izquierdo-Díaz, M.; Rojas, E.; Sanz, D.

    2015-12-01

    A simple analytical method using low volumes of solvent for determining selected PAHs and NPAHs in PM samples is presented. The proposed extraction method was compared with pressurized fluid (PFE) and microwave (MC) extraction techniques and intermediate precision associated to analytical measurements were estimated. Extraction by agitation with 8 mL of dichloromethane yielded recoveries above 80% compared to those obtained from PFE extraction. Regarding intermediate precision results, values between 10-20% were reached showing increases of dispersion for compounds with high volatility and low levels of concentration. Within the framework of the INTA/CIEMAT research agreement for the PM characterization in gas turbine exhaust, the method was applied for analysis of aluminum foil substrates and quartz filters with mass loading ranged from 0.02 to 2 mg per sample.

  5. A Simplified Method for Sampling and Analysis of High Volume Surface Water for Organic Contaminants Using XAD-2

    Science.gov (United States)

    Datta, S.; Do, L.V.; Young, T.M.

    2004-01-01

    A simple compressed-gas driven system for field processing and extracting water for subsequent analyses of hydrophobic organic compounds is presented. The pumping device is a pneumatically driven pump and filtration system that can easily clarify at 4L/min. The extraction device uses compressed gas to drive filtered water through two parallel XAD-2 resin columns, at about 200 mL/min. No batteries or inverters are required for water collection or processing. Solvent extractions were performed directly in the XAD-2 glass columns. Final extracts are cleaned-up on Florisil cartridges without fractionation and contaminants analyzed by GC-MS. Method detection limits (MDLs) and recoveries for dissolved organic contaminants, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and pesticides are reported along with results of surface water analysis for the San Francisco Bay, CA.

  6. Concentrations of Contaminants with Regulatory Limits in Samples of Clam (Chamelea gallina) Collected along the Abruzzi Region Coast in Central Italy.

    Science.gov (United States)

    Visciano, Pierina; Scortichini, Giampiero; Suzzi, Giovanna; Diletti, Gianfranco; Schirone, Maria; Martino, Giuseppe

    2015-09-01

    Concentrations of pollutants with regulatory limits were determined in specimens of Chamelea gallina, a species of clam collected along the Abruzzi coastal region of the central Adriatic Sea. Nine sampling sites were selected to evaluate the distribution of contaminants in the environment and the health risk for consumers. The concentrations of all the examined compounds were lower than the maximums set by European legislation. Polycyclic aromatic hydrocarbons and total mercury were below the detection limit (0.18 μg/kg for benzo[a]anthracene, 0.30 μg/kg for chrysene, 0.12 μg/kg for benzo[b]fluoranthene, 0.08 μg/kg for benzo[a]pyrene, and 0.0050 mg/kg for total mercury) in all the analyzed samples. Mean concentrations of lead and cadmium were 0.104 and 0.110 mg/kg, respectively. Of the non-dioxin-like polychlorinated biphenyls, PCB-153, PCB-180, and PCB-138 were the most abundant at all sampling sites (1a to 9a) at 0.25 mi (ca. 0.4 km) and at some sampling sites (1b, 2b, 3b, 5b and 7b) at 0.35 mi (ca. 0.56 km). Principal component analysis revealed that the concentrations of dioxin-like polychlorinated biphenyls were similar at the majority of sampling sites, and O8CDD and 2,3,7,8-T4CDF were the predominant dioxin congeners.

  7. SeaWiFS technical report series. Volume 4: An analysis of GAC sampling algorithms. A case study

    Science.gov (United States)

    Yeh, Eueng-Nan (Editor); Hooker, Stanford B. (Editor); Hooker, Stanford B. (Editor); Mccain, Charles R. (Editor); Fu, Gary (Editor)

    1992-01-01

    The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) instrument will sample at approximately a 1 km resolution at nadir which will be broadcast for reception by realtime ground stations. However, the global data set will be comprised of coarser four kilometer data which will be recorded and broadcast to the SeaWiFS Project for processing. Several algorithms for degrading the one kilometer data to four kilometer data are examined using imagery from the Coastal Zone Color Scanner (CZCS) in an effort to determine which algorithm would best preserve the statistical characteristics of the derived products generated from the one kilometer data. Of the algorithms tested, subsampling based on a fixed pixel within a 4 x 4 pixel array is judged to yield the most consistent results when compared to the one kilometer data products.

  8. The potential of distance sampling methods to estimate abundance of mountain ungulates: review of usefulness and limitations

    Directory of Open Access Journals (Sweden)

    Pérez, J. M.

    2002-12-01

    Full Text Available Accurate assessment of the populations of mountain ungulates is difficult. Topography and behaviour of animals are important factors influencing detectability, on which direct methods are based. Sympathry with other wild and domestic ungulates increases error of dung identification. Other factors, such as the size of the area to be surveyed, or unmarked populations of the target species, suggests the choice of curvilinear transects. If the basic assumptions of Distance Sampling methodology are met, then estimates of population density and accuracy can be obtained. Current technology (GPS, laser rangefinders, and G.I.S. can be used to achieve accurate measurements of distances and angles. A crucial problem is to estimate the effective area sampled around each travelling path. Therefore, researchers and managers of mountain ungulates need an adaptation of Distance Sampling methodology to account for a tridimensional scenario imposed by the slope of mountains. There is also a requirement to standardize protocols for collecting data. Alternatives for design surveys and collection data when working with populations of mountain ungulates are discussed.

    [fr]
    L'estimation précise de l'abondance des ongulés de montagne devient difficile. La détectabilité est conditionnée par la topographie et le comportement des animaux; c'est sur ce dernier cas que les méthodes directes s'appuient. La sympatrie entre les ongulés sauvages et domestiques augmente l'erreur d'identification des excréments. D'autres facteurs, comme par exemple les grandes surfaces à surveiller ou les populations non marquées des espèces-cibles, peuvent nous conduire à des comptages sur transect curvilignes ou sur des points. Si l'on tient compte des idées basiques concernant la méthodologie appelée «Échantillonage à distance», alors les estimations correspondantes de densité avec leurs mesures de précision peuvent être obtenues. La technologie à notre port

  9. Conversion of a Continuous Flow Cavity Ring-Down Spectrometer to Measure 13C in CO2 Using Static Analyses of Small Volume Grab Samples (Invited)

    Science.gov (United States)

    Rahn, T.; Jordanova, K.; Berryman, E.; van Pelt, A. D.; Marshall, J. D.

    2010-12-01

    Laser-based analyses of concentration and isotopic content allow unprecedented temporal resolution for a number of important atmospheric constituents. Perhaps overlooked is the potential for these tools to also provide analyses in a more traditional "mass spectrometric" mode that is readily deployable in a field setting. Certain sampling regimes (e.g. soil profiles) are not appropriate for continuous sampling due to their slow change and disturbance of gradients caused by frequent/continuous sampling. We have modified the inlet and plumbing system of a commercial continuous flow cavity ring-down spectrometer in a manner that allows for 13C analyses of CO2 from syringe samples at volumes as small as 25 ml of air with ambient concentrations of CO2. The method employs an external high vacuum pump and a series of programmable micro-valves that allow for evacuation of the long-pass ring-down cell followed by controlled filling, via syringe, of the cavity to optimal sampling pressure and subsequent static analysis of CO2 concentration and 13C /13C ratios. The set-up is field deployable with modest power requirements and allows for near real time analysis in a variety of sampling environments and on-the-fly determination of sampling protocol. In its current configuration, the system provides precision of 1% for CO2 concentration and 0.3 permil for δ13C in replicate analyses of reference air. We have deployed the system to a field laboratory in central New Mexico near a controlled tree mortality research site where post-mortality ecosystem CO2 evolution is being studied. Results from the first field season will be presented and discussed.

  10. Late Toxicity After Intensity-Modulated Radiation Therapy for Localized Prostate Cancer: An Exploration of Dose-Volume Histogram Parameters to Limit Genitourinary and Gastrointestinal Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Pederson, Aaron W.; Fricano, Janine; Correa, David; Pelizzari, Charles A. [Department of Radiation and Cellular Oncology, Pritzker School of Medicine, University of Chicago, Chicago, IL (United States); Liauw, Stanley L., E-mail: sliauw@radonc.uchicago.edu [Department of Radiation and Cellular Oncology, Pritzker School of Medicine, University of Chicago, Chicago, IL (United States)

    2012-01-01

    Purpose: To characterize the late genitourinary (GU) and gastrointestinal (GI) toxicity for prostate cancer patients treated with intensity-modulated radiation therapy (IMRT) and propose dose-volume histogram (DVH) guidelines to limit late treatment-related toxicity. Methods and Materials: In this study 296 consecutive men were treated with IMRT for adenocarcinoma of the prostate. Most patients received treatment to the prostate with or without proximal seminal vesicles (90%), to a median dose of 76 Gy. Concurrent androgen deprivation therapy was given to 150 men (51%) for a median of 4 months. Late toxicity was defined by Common Toxicity Criteria version 3.0 as greater than 3 months after radiation therapy completion. Four groupings of DVH parameters were defined, based on the percentage of rectal or bladder tissue receiving 70 Gy (V{sub 70}), 65 Gy (V{sub 65}), and 40 Gy (V{sub 40}). These DVH groupings, as well as clinical and treatment characteristics, were correlated to maximal Grade 2+ GU and GI toxicity. Results: With a median follow-up of 41 months, the 4-year freedom from maximal Grade 2+ late toxicity was 81% and 91% for GU and GI systems, respectively, and by last follow-up, the rates of Grade 2+ GU and GI toxicity were 9% and 5%, respectively. On multivariate analysis, whole-pelvic IMRT was associated with Grade 2+ GU toxicity and age was associated with Grade 2+ GI toxicity. Freedom from Grade 2+ GI toxicity at 4 years was 100% for men with rectal V{sub 70} {<=}10%, V{sub 65} {<=}20%, and V{sub 40} {<=}40%; 92% for men with rectal V{sub 70} {<=}20%, V{sub 65} {<=}40%, and V{sub 40} {<=}80%; and 85% for men exceeding these criteria (p = 0.13). These criteria were more highly associated with GI toxicity in men aged {>=}70 years (p = 0.07). No bladder dose-volume relationships were associated with the risk of GU toxicity. Conclusions: IMRT is associated with low rates of severe GU or GI toxicity after treatment for prostate cancer. Rectal dose constraints

  11. Heteronuclear Micro-Helmholtz Coil Facilitates µm-Range Spatial and Sub-Hz Spectral Resolution NMR of nL-Volume Samples on Customisable Microfluidic Chips.

    Science.gov (United States)

    Spengler, Nils; Höfflin, Jens; Moazenzadeh, Ali; Mager, Dario; MacKinnon, Neil; Badilita, Vlad; Wallrabe, Ulrike; Korvink, Jan G

    2016-01-01

    We present a completely revised generation of a modular micro-NMR detector, featuring an active sample volume of ∼ 100 nL, and an improvement of 87% in probe efficiency. The detector is capable of rapidly screening different samples using exchangeable, application-specific, MEMS-fabricated, microfluidic sample containers. In contrast to our previous design, the sample holder chips can be simply sealed with adhesive tape, with excellent adhesion due to the smooth surfaces surrounding the fluidic ports, and so withstand pressures of ∼2.5 bar, while simultaneously enabling high spectral resolution up to 0.62 Hz for H2O, due to its optimised geometry. We have additionally reworked the coil design and fabrication processes, replacing liquid photoresists by dry film stock, whose final thickness does not depend on accurate volume dispensing or precise levelling during curing. We further introduced mechanical alignment structures to avoid time-intensive optical alignment of the chip stacks during assembly, while we exchanged the laser-cut, PMMA spacers by diced glass spacers, which are not susceptible to melting during cutting. Doing so led to an overall simplification of the entire fabrication chain, while simultaneously increasing the yield, due to an improved uniformity of thickness of the individual layers, and in addition, due to more accurate vertical positioning of the wirebonded coils, now delimited by a post base plateau. We demonstrate the capability of the design by acquiring a 1H spectrum of ∼ 11 nmol sucrose dissolved in D2O, where we achieved a linewidth of 1.25 Hz for the TSP reference peak. Chemical shift imaging experiments were further recorded from voxel volumes of only ∼ 1.5 nL, which corresponded to amounts of just 1.5 nmol per voxel for a 1 M concentration. To extend the micro-detector to other nuclei of interest, we have implemented a trap circuit, enabling heteronuclear spectroscopy, demonstrated by two 1H/13C 2D HSQC experiments.

  12. Heteronuclear Micro-Helmholtz Coil Facilitates µm-Range Spatial and Sub-Hz Spectral Resolution NMR of nL-Volume Samples on Customisable Microfluidic Chips.

    Directory of Open Access Journals (Sweden)

    Nils Spengler

    Full Text Available We present a completely revised generation of a modular micro-NMR detector, featuring an active sample volume of ∼ 100 nL, and an improvement of 87% in probe efficiency. The detector is capable of rapidly screening different samples using exchangeable, application-specific, MEMS-fabricated, microfluidic sample containers. In contrast to our previous design, the sample holder chips can be simply sealed with adhesive tape, with excellent adhesion due to the smooth surfaces surrounding the fluidic ports, and so withstand pressures of ∼2.5 bar, while simultaneously enabling high spectral resolution up to 0.62 Hz for H2O, due to its optimised geometry. We have additionally reworked the coil design and fabrication processes, replacing liquid photoresists by dry film stock, whose final thickness does not depend on accurate volume dispensing or precise levelling during curing. We further introduced mechanical alignment structures to avoid time-intensive optical alignment of the chip stacks during assembly, while we exchanged the laser-cut, PMMA spacers by diced glass spacers, which are not susceptible to melting during cutting. Doing so led to an overall simplification of the entire fabrication chain, while simultaneously increasing the yield, due to an improved uniformity of thickness of the individual layers, and in addition, due to more accurate vertical positioning of the wirebonded coils, now delimited by a post base plateau. We demonstrate the capability of the design by acquiring a 1H spectrum of ∼ 11 nmol sucrose dissolved in D2O, where we achieved a linewidth of 1.25 Hz for the TSP reference peak. Chemical shift imaging experiments were further recorded from voxel volumes of only ∼ 1.5 nL, which corresponded to amounts of just 1.5 nmol per voxel for a 1 M concentration. To extend the micro-detector to other nuclei of interest, we have implemented a trap circuit, enabling heteronuclear spectroscopy, demonstrated by two 1H/13C 2D HSQC

  13. Remedial investigation sampling and analysis plan for J-Field, Aberdeen Proving Ground, Maryland: Volume 2, Quality Assurance Project Plan

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, S.; Martino, L.; Patton, T.

    1995-03-01

    J-Field encompasses about 460 acres at the southern end of the Gunpowder Neck Peninsula in the Edgewood Area of APG (Figure 2.1). Since World War II, the Edgewood Area of APG has been used to develop, manufacture, test, and destroy chemical agents and munitions. These materials were destroyed at J-Field by open burning and open detonation (OB/OD). For the purposes of this project, J-Field has been divided into eight geographic areas or facilities that are designated as areas of concern (AOCs): the Toxic Burning Pits (TBP), the White Phosphorus Burning Pits (WPP), the Riot Control Burning Pit (RCP), the Robins Point Demolition Ground (RPDG), the Robins Point Tower Site (RPTS), the South Beach Demolition Ground (SBDG), the South Beach Trench (SBT), and the Prototype Building (PB). The scope of this project is to conduct a remedial investigation/feasibility study (RI/FS) and ecological risk assessment to evaluate the impacts of past disposal activities at the J-Field site. Sampling for the RI will be carried out in three stages (I, II, and III) as detailed in the FSP. A phased approach will be used for the J-Field ecological risk assessment (ERA).

  14. A simple robust and accurate a posteriori sub-cell finite volume limiter for the discontinuous Galerkin method on unstructured meshes

    Science.gov (United States)

    Dumbser, Michael; Loubère, Raphaël

    2016-08-01

    In this paper we propose a simple, robust and accurate nonlinear a posteriori stabilization of the Discontinuous Galerkin (DG) finite element method for the solution of nonlinear hyperbolic PDE systems on unstructured triangular and tetrahedral meshes in two and three space dimensions. This novel a posteriori limiter, which has been recently proposed for the simple Cartesian grid case in [62], is able to resolve discontinuities at a sub-grid scale and is substantially extended here to general unstructured simplex meshes in 2D and 3D. It can be summarized as follows: At the beginning of each time step, an approximation of the local minimum and maximum of the discrete solution is computed for each cell, taking into account also the vertex neighbors of an element. Then, an unlimited discontinuous Galerkin scheme of approximation degree N is run for one time step to produce a so-called candidate solution. Subsequently, an a posteriori detection step checks the unlimited candidate solution at time t n + 1 for positivity, absence of floating point errors and whether the discrete solution has remained within or at least very close to the bounds given by the local minimum and maximum computed in the first step. Elements that do not satisfy all the previously mentioned detection criteria are flagged as troubled cells. For these troubled cells, the candidate solution is discarded as inappropriate and consequently needs to be recomputed. Within these troubled cells the old discrete solution at the previous time tn is scattered onto small sub-cells (Ns = 2 N + 1 sub-cells per element edge), in order to obtain a set of sub-cell averages at time tn. Then, a more robust second order TVD finite volume scheme is applied to update the sub-cell averages within the troubled DG cells from time tn to time t n + 1. The new sub-grid data at time t n + 1 are finally gathered back into a valid cell-centered DG polynomial of degree N by using a classical conservative and higher order

  15. Simultaneous determination of the Cd and Zn total body burden of individual, nearly microscopic, nanoliter-volume aquatic organisms (Hyalella azteca) by rhenium-cup in-torch vaporization (ITV) sample introduction and axially viewed ICP-AES

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Andrea T.; Badiei, Hamid R.; Karanassios, Vassili [University of Waterloo, Department of Chemistry, Waterloo, ON (Canada); Evans, J. Catherine [University of Waterloo, Department of Biology, Waterloo, ON (Canada)

    2004-09-01

    The Cd and Zn total body burden of individual, up to 7-day-old aquatic organisms (Hyalella aztecabenthic amphipod) with an average volume of approximately 100 nL was determined simultaneously by using rhenium-cup (Re-cup) in-torch vaporization (ITV) sample introduction and an axially viewed inductively coupled plasma atomic emission spectrometry (ICP-AES) system. The direct elemental analysis capabilities of this system (i.e., no sample digestion) reduced sample preparation time, eliminated contamination concerns from the digestion reagent and, owing to its detection limits (e.g., in the low pg range for Cd and Zn), vit enabled simultaneous determinations of Cd and Zn in individual, neonate and young juvenile specimens barely visible to the unaided eye (e.g., nearly microscopic). As for calibration, liquid standards and the standard additions method were tested. Both methods gave comparable results, thus indicating that in this case liquid standards can be employed for calibration, and in the process making use of the standard additions method unnecessary. Overall, the ITV-ICP-AES approach by-passed the time-consuming acid digestions, eliminated the potential for contamination from the digestion reagents, improved considerably the speed of acquisition of analytical information and enabled simultaneous determinations of two elements using individual biological specimens. (orig.)

  16. Diagnosis of Ovarian Carcinoma Histotype Based on Limited Sampling: A Prospective Study Comparing Cytology, Frozen Section, and Core Biopsies to Full Pathologic Examination.

    Science.gov (United States)

    Hoang, Lien N; Zachara, Susanna; Soma, Anita; Köbel, Martin; Lee, Cheng-Han; McAlpine, Jessica N; Huntsman, David; Thomson, Thomas; van Niekerk, Dirk; Singh, Naveena; Gilks, C Blake

    2015-11-01

    Growing insights into the biological features and molecular underpinnings of ovarian cancer has prompted a shift toward histotype-specific treatments and clinical trials. As a result, the preoperative diagnosis of ovarian carcinomas based on small tissue sampling is rapidly gaining importance. The data on the accuracy of ovarian carcinoma histotype-specific diagnosis based on small tissue samples, however, remains very limited in the literature. Herein, we describe a prospective series of 30 ovarian tumors diagnosed using cytology, frozen section, core needle biopsy, and immunohistochemistry (p53, p16, WT1, HNF-1β, ARID1A, TFF3, vimentin, and PR). The accuracy of histotype diagnosis using each of these modalities was 52%, 81%, 85%, and 84% respectively, using the final pathology report as the reference standard. The accuracy of histotype diagnosis using the Calculator for Ovarian Subtype Prediction (COSP), which evaluates immunohistochemical stains independent of histopathologic features, was 85%. Diagnostic accuracy varied across histotype and was lowest for endometrioid carcinoma across all diagnostic modalities (54%). High-grade serous carcinomas were the most overdiagnosed on core needle biopsy (accounting for 45% of misdiagnoses) and clear cell carcinomas the most overdiagnosed on frozen section (accounting for 36% of misdiagnoses). On core needle biopsy, 2/30 (7%) cases had a higher grade lesion missed due to sampling limitations. In this study, we identify several challenges in the diagnosis of ovarian tumors based on limited tissue sampling. Recognition of these scenarios can help improve diagnostic accuracy as we move forward with histotype-specific therapeutic strategies.

  17. Novel system using microliter order sample volume for measuring arterial radioactivity concentrations in whole blood and plasma for mouse PET dynamic study.

    Science.gov (United States)

    Kimura, Yuichi; Seki, Chie; Hashizume, Nobuya; Yamada, Takashi; Wakizaka, Hidekatsu; Nishimoto, Takahiro; Hatano, Kentaro; Kitamura, Keishi; Toyama, Hiroshi; Kanno, Iwao

    2013-11-21

    This study aimed to develop a new system, named CD-Well, for mouse PET dynamic study. CD-Well allows the determination of time-activity curves (TACs) for arterial whole blood and plasma using 2-3 µL of blood per sample; the minute sample size is ideal for studies in small animals. The system has the following merits: (1) measures volume and radioactivity of whole blood and plasma separately; (2) allows measurements at 10 s intervals to capture initial rapid changes in the TAC; and (3) is compact and easy to handle, minimizes blood loss from sampling, and delay and dispersion of the TAC. CD-Well has 36 U-shaped channels. A drop of blood is sampled into the opening of the channel and stored there. After serial sampling is completed, CD-Well is centrifuged and scanned using a flatbed scanner to define the regions of plasma and blood cells. The length measured is converted to volume because the channels have a precise and uniform cross section. Then, CD-Well is exposed to an imaging plate to measure radioactivity. Finally, radioactivity concentrations are computed. We evaluated the performance of CD-Well in in vitro measurement and in vivo (18)F-fluorodeoxyglucose and [(11)C]2-carbomethoxy-3β-(4-fluorophenyl) tropane studies. In in vitro evaluation, per cent differences (mean±SE) from manual measurement were 4.4±3.6% for whole blood and 4.0±3.5% for plasma across the typical range of radioactivity measured in mouse dynamic study. In in vivo studies, reasonable TACs were obtained. The peaks were captured well, and the time courses coincided well with the TAC derived from PET imaging of the heart chamber. The total blood loss was less than 200 µL, which had no physiological effect on the mice. CD-Well demonstrates satisfactory performance, and is useful for mouse PET dynamic study.

  18. Detection of aqueous VEGF concentrations before and after intravitreal injection of anti-VEGF antibody using low-volume sampling paper-based ELISA.

    Science.gov (United States)

    Hsu, Min-Yen; Hung, Yu-Chien; Hwang, De-Kuang; Lin, Shang-Chi; Lin, Keng-Hung; Wang, Chun-Yuan; Choi, Hin-Yeung; Wang, Yu-Ping; Cheng, Chao-Min

    2016-10-11

    Intraocular vascular endothelial growth factor (VEGF) levels play an important role in the pathogenesis of blindness-related diseases, such as age-related macular degeneration (AMD). Here, we aimed to develop a paper-based enzyme-linked immunosorbent assay (P-ELISA) to analyze the suppression of aqueous VEGF concentrations following intravitreal injection (IVI) of anti-VEGF antibody (bevacizumab or ranibizumab). A total of 25 eyes with wet AMD, one with myopic neovascularization, and one with polypoidal choroidal vasculopathy were enrolled in this study. The limit of detection using P-ELISA was 0.03 pg/mL. Forty-six consecutive samples of aqueous humor were acquired. From all samples, 66.67% (10/15) achieved complete VEGF suppression (below the detection limit) within 5 weeks of receiving IVI of anti-VEGF antibody. Only 13.33% of samples (2/15) achieved complete VEGF suppression 5 weeks after receiving treatment. In some patients, elevated VEGF was still detected 5 weeks after receipt of anti-VEGF antibody, and all samples (10/10) were found to have elevated VEGF levels 49 days after treatment. Thus, we suggest that monthly IVI of anti-VEGF antibody may be required to ensure durable VEGF inhibition. Ultrasensitive P-ELISA can detect elevated VEGF at an earlier time point and may facilitate decision-making regarding appropriate treatment strategies.

  19. Versatile, ultra-low sample volume gas analyzer using a rapid, broad-tuning ECQCL and a hollow fiber gas cell

    Energy Technology Data Exchange (ETDEWEB)

    Kriesel, Jason M.; Makarem, Camille N.; Phillips, Mark C.; Moran, James J.; Coleman, Max; Christensen, Lance; Kelly, James F.

    2017-05-05

    We describe a versatile mid-infrared (Mid-IR) spectroscopy system developed to measure the concentration of a wide range of gases with an ultra-low sample size. The system combines a rapidly-swept external cavity quantum cascade laser (ECQCL) with a hollow fiber gas cell. The ECQCL has sufficient spectral resolution and reproducibility to measure gases with narrow features (e.g., water, methane, ammonia, etc.), and also the spectral tuning range needed to measure volatile organic compounds (VOCs), (e.g., aldehydes, ketones, hydrocarbons), sulfur compounds, chlorine compounds, etc. The hollow fiber is a capillary tube having an internal reflective coating optimized for transmitting the Mid-IR laser beam to a detector. Sample gas introduced into the fiber (e.g., internal volume = 0.6 ml) interacts strongly with the laser beam, and despite relatively modest path lengths (e.g., L ~ 3 m), the requisite quantity of sample needed for sensitive measurements can be significantly less than what is required using conventional IR laser spectroscopy systems. Example measurements are presented including quantification of VOCs relevant for human breath analysis with a sensitivity of ~2 picomoles at a 1 Hz data rate.

  20. Monte Carlo simulations incorporating Mie calculations of light transport in tissue phantoms: Examination of photon sampling volumes for endoscopically compatible fiber optic probes

    Energy Technology Data Exchange (ETDEWEB)

    Mourant, J.R.; Hielscher, A.H.; Bigio, I.J.

    1996-04-01

    Details of the interaction of photons with tissue phantoms are elucidated using Monte Carlo simulations. In particular, photon sampling volumes and photon pathlengths are determined for a variety of scattering and absorption parameters. The Monte Carlo simulations are specifically designed to model light delivery and collection geometries relevant to clinical applications of optical biopsy techniques. The Monte Carlo simulations assume that light is delivered and collected by two, nearly-adjacent optical fibers and take into account the numerical aperture of the fibers as well as reflectance and refraction at interfaces between different media. To determine the validity of the Monte Carlo simulations for modeling the interactions between the photons and the tissue phantom in these geometries, the simulations were compared to measurements of aqueous suspensions of polystyrene microspheres in the wavelength range 450-750 nm.

  1. Spectroelectrochemical sensing based on multimode selectivity simultaneously achievable in a single device. 17. Improvement in detection limits using ultrathin perfluorosulfonated ionomer films in conjunction with continuous sample flow.

    Science.gov (United States)

    Andria, Sara E; Richardson, John N; Kaval, Necati; Zudans, Imants; Seliskar, Carl J; Heineman, William R

    2004-06-01

    We report herein an attenuated total reflectance (ATR) absorbance-based spectroelectrochemical sensor for tris(2,2'-bipyridyl)ruthenium(II) ion [Ru(bpy)(3)(2+)] that employs ultrathin (24-50 nm) Nafion films as the charge-selective layer. This film serves to sequester and preconcentrate the analyte at the optically transparent electrode surface such that it can be efficiently detected optically via electrochemical modulation. Our studies indicate that use of ultrathin films in tandem with continuous flow of sample solution through the cell compartment leads to a 100-500-fold enhancement in detection limit (10 nM) compared to earlier absorbance-based spectroelectrochemical sensors ( approximately 1-5 microM); markedly shorter analysis times also result. We report the dependence of the measured absorbance on sample flow rate and Nafion film thickness, and also provide calibration curves that illustrate the linear range and detection limits of the sensor using a 24 nm film at a constant sample flow rate of 0.07 mL/min.

  2. Square wave adsorptive cathodic stripping voltammetry automated by sequential injection analysis Potentialities and limitations exemplified by the determination of methyl parathion in water samples.

    Science.gov (United States)

    dos Santos, Luciana B O; Masini, Jorge C

    2008-01-14

    This paper describes the development and evaluation of a sequential injection method to automate the determination of methyl parathion by square wave adsorptive cathodic stripping voltammetry exploiting the concept of monosegmented flow analysis to perform in-line sample conditioning and standard addition. Accumulation and stripping steps are made in the sample medium conditioned with 40 mmolL(-1) Britton-Robinson buffer (pH 10) in 0.25 molL(-1) NaNO3. The homogenized mixture is injected at a flow rate of 10 microLs(-1) toward the flow cell, which is adapted to the capillary of a hanging drop mercury electrode. After a suitable deposition time, the flow is stopped and the potential is scanned from -0.3 to -1.0V versus Ag/AgCl at frequency of 250 Hz and pulse height of 25 mV. The linear dynamic range is observed for methyl parathion concentrations between 0.010 and 0.50 mgL(-1), with detection and quantification limits of 2 and 7 microgL(-1), respectively. The sampling throughput is 25 h(-1) if the in line standard addition and sample conditioning protocols are followed, but this frequency can be increased up to 61 h(-1) if the sample is conditioned off-line and quantified using an external calibration curve. The method was applied for determination of methyl parathion in spiked water samples and the accuracy was evaluated either by comparison to high performance liquid chromatography with UV detection, or by the recovery percentages. Although no evidences of statistically significant differences were observed between the expected and obtained concentrations, because of the susceptibility of the method to interference by other pesticides (e.g., parathion, dichlorvos) and natural organic matter (e.g., fulvic and humic acids), isolation of the analyte may be required when more complex sample matrices are encountered.

  3. Determination of selected perfluorinated alkyl acids and persistent organic pollutants from a small volume human serum sample relevant for epidemiological studies.

    Science.gov (United States)

    Koponen, Jani; Rantakokko, Panu; Airaksinen, Riikka; Kiviranta, Hannu

    2013-09-27

    A simple and fast method is presented for the determination of selected persistent organic pollutants (POPs) and perfluorinated alkyl acids (PFAAs), a subgroup of per- and polyfluorinated alkyl substances (PFAS) from a single 200μl aliquot of serum. Sample pretreatment starts with dispersive solid phase extraction of POPs to dichloromethane-hexane, which is immediately poured to cleanup column. POPs are eluted from column and concentrated for GC-MS/MS analysis. PFAAs are trapped to dispersant and are then extracted with ammonium acetate in methanol, concentrated and analysed with LC-MS/MS. For POPs, the limit of detection (LOD) ranged from 1.6 to 17pg/ml. Oxychlordane and dichlorodiphenyltrichloroethane had LODs in the upper end of this range as they were more labile and prone for interferences in the GC-MS/MS. For PFAAs, the LOD range from 0.027 to 0.068ng/ml. For POPs, the accuracy from Standard Reference Materials SRM 1589a and Arctic Monitoring and Assessment Programme (AMAP) intercalibration samples range from 74 to 127% and the repeatability (relative standard deviation, RSD%) from 2.0 to 15%. For PFAAs, the accuracy from AMAP samples ranged from 90 to 110% and from LOQ level spiked serum samples from 72 to 133%. Repeatability from AMAP and LOQ samples ranged from 1.6 to 7.3% and 5.5 to 15%, respectively. The presented method is useful in epidemiological studies where only limited amount of serum is available. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Determination of Fe-55 and Ni-63 in Environmental Samples. Analytical Problems. Characteristic Limits. Automatized Calculation; Determinacion de 55{sup F}e y 63{sup N}i en Muestras Ambientales. Problemas Analiticos. Limites Caracteristicos. Calculo Automatizado

    Energy Technology Data Exchange (ETDEWEB)

    Gasco, C.; Navarro, N.; Gonzalez, P.; Heras, M. C.; Gapan, M. P.; Alonso, C.; Calderon, A.; Sanchez, D.; Morante, R.; Fernandez, M.; Gajate, A.; Alvarez, A.

    2008-08-06

    The Department of Vigilance Radiologica y Radiactividad Ambiental from CIEMAT has developed an appropriate analytical methodology for Fe-55 and Ni-63 sequential determination in environmental samples based on the procedure used by RIS0 Laboratories. The experimental results obtained in the mayor and minor elements behaviour (soil and air constituents) in the different types of resins used for separating Fe-55 and Ni-63 are showed in this report. The measuring method of both isotopes by scintillation counting has been optimized with Ultima Gold liquid with different concentrations of stable element Fe and Ni. The decontamination factors of different gamma-emitters are experimentally determined in this method with the presence of soil matrix. The Fe-55 and Ni-63 activity concentrations and their associated uncertainties have been calculated from the counting data and sample preparation. A computer application has been implemented in Visual Basic in excel sheets for: (I) obtaining the counting data from spectrometer and counts in each window, (II) representing graphically the background and sample spectrums, (III) determining the activity concentration and its associated uncertainty and (IV) calculating the characteristic limits using ISO 11929 (2007) with various confidence levels. (Author) 30 refs.

  5. Optimisation of a selective method for the determination of organophosphorous triesters in outdoor particulate samples by pressurised liquid extraction and large-volume injection gas chromatography-positive chemical ionisation-tandem mass spectrometry.

    Science.gov (United States)

    Quintana, José Benito; Rodil, Rosario; López-Mahía, Purificación; Muniategui-Lorenzo, Soledad; Prada-Rodríguez, Darío

    2007-07-01

    A selective analytical method for the determination of nine organophosphate triesters and triphenylphosphine oxide (TPPO) in outdoor particulate matter is presented. It involves a fully automated pressurised liquid extraction (PLE) step, integrating an alumina clean-up process, and subsequent determination by large-volume injection gas chromatography-positive chemical ionisation-tandem mass spectrometry (LVI-GC-PCI-MS/MS). The extraction variables (solvent, amount of adsorbent, temperature, time and number of cycles) were optimised using a multicriteria strategy which implements a desirability function that maximises both extraction and clean-up efficiencies while searching for the best-compromise PLE conditions. The final method affords quantification limits of between 0.01 and 0.3 microg g(-1) and recoveries of >80%, with the exceptions of the most polar analytes, TCEP and TPPO (~65%) for both urban dust and PM10 samples. Moreover, the method permitted the levels of these compounds in dust deposited outdoors (between LOD and 0.5 microg g(-1) for TEHP) and PM10 samples (between LOD and 2.4 microg m(-3) for TiBP) to be measured and reported for the first time.

  6. Problems, possibilities and limitations of inductively coupled plasma atomic emission spectrometry in the determination of platinum, palladium and rhodium in samples with different matrix composition

    Science.gov (United States)

    Petrova, P.; Velichkov, S.; Velitchkova, N.; Havezov, I.; Daskalova, N.

    2010-02-01

    The economic and geological importance of platinum group of elements has led to the development of analytical methods to quantify them in different types of samples. In the present paper the quantitative information for spectral interference in radial viewing 40.68 MHz inductively coupled plasma atomic emission spectrometry in the determination of Pt, Pd and Rh in the presence of complex matrix, containing Al, Ca, Fe, Mg, Mn, P and Ti as matrix constituents was obtained. The database was used for optimum line selections. By using the selected analysis lines the following detection limits in ng g - 1 were obtained: Pt 1700, Pd-1440, Rh-900. The reached detection limits determine the possibilities and limitation of the direct ICP-AES method in the determination of Pt, Pd and Rh in geological and environmental materials. The database for spectral interferences in the presence of aluminum can be used for the determination of platinum group of elements in car catalysts. The accuracy of the analytical results was experimentally demonstrated by two certified reference materials that were analyzed: SARM 7, Pt ore and recycled auto-catalyst certified reference material SRM 2556.

  7. Problems, possibilities and limitations of inductively coupled plasma atomic emission spectrometry in the determination of platinum, palladium and rhodium in samples with different matrix composition

    Energy Technology Data Exchange (ETDEWEB)

    Petrova, P.; Velichkov, S. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. bl. 11, 1113 Sofia (Bulgaria); Velitchkova, N. [Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bontchev Str., bl.24, 1113 Sofia (Bulgaria); Havezov, I. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. bl. 11, 1113 Sofia (Bulgaria); Daskalova, N., E-mail: das15482@svr.igic.bas.b [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. bl. 11, 1113 Sofia (Bulgaria)

    2010-02-15

    The economic and geological importance of platinum group of elements has led to the development of analytical methods to quantify them in different types of samples. In the present paper the quantitative information for spectral interference in radial viewing 40.68 MHz inductively coupled plasma atomic emission spectrometry in the determination of Pt, Pd and Rh in the presence of complex matrix, containing Al, Ca, Fe, Mg, Mn, P and Ti as matrix constituents was obtained. The database was used for optimum line selections. By using the selected analysis lines the following detection limits in ng g{sup -1} were obtained: Pt 1700, Pd-1440, Rh-900. The reached detection limits determine the possibilities and limitation of the direct ICP-AES method in the determination of Pt, Pd and Rh in geological and environmental materials. The database for spectral interferences in the presence of aluminum can be used for the determination of platinum group of elements in car catalysts. The accuracy of the analytical results was experimentally demonstrated by two certified reference materials that were analyzed: SARM 7, Pt ore and recycled auto-catalyst certified reference material SRM 2556.

  8. Clinical Application of Picodroplet Digital PCR Technology for Rapid Detection of EGFR T790M in Next-Generation Sequencing Libraries and DNA from Limited Tumor Samples.

    Science.gov (United States)

    Borsu, Laetitia; Intrieri, Julie; Thampi, Linta; Yu, Helena; Riely, Gregory; Nafa, Khedoudja; Chandramohan, Raghu; Ladanyi, Marc; Arcila, Maria E

    2016-11-01

    Although next-generation sequencing (NGS) is a robust technology for comprehensive assessment of EGFR-mutant lung adenocarcinomas with acquired resistance to tyrosine kinase inhibitors, it may not provide sufficiently rapid and sensitive detection of the EGFR T790M mutation, the most clinically relevant resistance biomarker. Here, we describe a digital PCR (dPCR) assay for rapid T790M detection on aliquots of NGS libraries prepared for comprehensive profiling, fully maximizing broad genomic analysis on limited samples. Tumor DNAs from patients with EGFR-mutant lung adenocarcinomas and acquired resistance to epidermal growth factor receptor inhibitors were prepared for Memorial Sloan-Kettering-Integrated Mutation Profiling of Actionable Cancer Targets sequencing, a hybrid capture-based assay interrogating 410 cancer-related genes. Precapture library aliquots were used for rapid EGFR T790M testing by dPCR, and results were compared with NGS and locked nucleic acid-PCR Sanger sequencing (reference high sensitivity method). Seventy resistance samples showed 99% concordance with the reference high sensitivity method in accuracy studies. Input as low as 2.5 ng provided a sensitivity of 1% and improved further with increasing DNA input. dPCR on libraries required less DNA and showed better performance than direct genomic DNA. dPCR on NGS libraries is a robust and rapid approach to EGFR T790M testing, allowing most economical utilization of limited material for comprehensive assessment. The same assay can also be performed directly on any limited DNA source and cell-free DNA.

  9. Architectural and Behavioral Systems Design Methodology and Analysis for Optimal Habitation in a Volume-Limited Spacecraft for Long Duration Flights

    Science.gov (United States)

    Kennedy, Kriss J.; Lewis, Ruthan; Toups, Larry; Howard, Robert; Whitmire, Alexandra; Smitherman, David; Howe, Scott

    2016-01-01

    As our human spaceflight missions change as we reach towards Mars, the risk of an adverse behavioral outcome increases, and requirements for crew health, safety, and performance, and the internal architecture, will need to change to accommodate unprecedented mission demands. Evidence shows that architectural arrangement and habitability elements impact behavior. Net habitable volume is the volume available to the crew after accounting for elements that decrease the functional volume of the spacecraft. Determination of minimum acceptable net habitable volume and associated architectural design elements, as mission duration and environment varies, is key to enabling, maintaining, andor enhancing human performance and psychological and behavioral health. Current NASA efforts to derive minimum acceptable net habitable volumes and study the interaction of covariates and stressors, such as sensory stimulation, communication, autonomy, and privacy, and application to internal architecture design layouts, attributes, and use of advanced accommodations will be presented. Furthermore, implications of crew adaptation to available volume as they transfer from Earth accommodations, to deep space travel, to planetary surface habitats, and return, will be discussed.

  10. Trace analysis of organic ions in ice samples by capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Huber, T. [Bern Univ. (Switzerland); Schwikowski, M.; Gaeggeler, H.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Capillary electrophoresis was tested as a new analytical method for ice samples. Comparisons to ion chromatography were made concerning accuracy, detection limits, reproducibility, necessary sample volume and time consumption. (author) 1 fig., 3 refs.

  11. Chronology and the upper dating limit for loess samples from Luochuan section in the Chinese Loess Plateau using quartz OSL SAR protocol

    Science.gov (United States)

    Lai, ZhongPing

    2010-01-01

    Luminescence dating of loess older than 100 ka has long been a challenge. It has been recently reported that, using optically stimulated luminescence (OSL) of fine-grained quartz (4-11 μm) extracted from loess, the range of luminescence dating could be pushed to ˜0.6 Ma with OSL ages being in agreement with independent ages [Watanuki, T., Murray, A.S., Tsukamoto, S., 2005. Quartz and polymineral luminescence dating of Japanese loess over the last 0.6 Ma: comparison with an independent chronology. Earth and Planetary Science Letters 240, 774-789]. The aim of this study is to provide a luminescence chronology (20 samples) for the standard Luochuan loess section, and to further examine the upper limit of quartz OSL dating for Chinese loess. The growth curve does not saturate at 700 Gy, and should allow reliable equivalent dose ( De) determination up to at least 400 Gy. However, when compared with independent chronological control, the De that could be treated as reliable is less than ˜230 Gy (corresponding to ˜70 ka in age for Chinese loess), and the De larger than ˜230 Gy should be underestimated. Ages for samples from the lower part of palaeosol S1 are severely underestimated, with the maximum age of 95 ka for a sample from the bottom of this palaeosol, much younger than the expected age of ˜128 ka. The maximum De obtained for sample L9/M, collected from loess layer L9 which is below the Matuyama-Brunhes (B/M) boundary whose age is ˜780 ka, is only 403 Gy which corresponds to an age of 107 ka. The cause of underestimation is not yet clear. The previous results by Watunuki et al. (2005) on the extension of OSL dating of loess to 0.6 Ma is not confirmed. When evaluating the validity of OSL ages in S1, another possibility is to question the already established chronological frame for Luochuan section, which is based on the hypothesis of continuous dust deposition. The assumption of an erosion hiatus between L2 and S1 could make the OSL ages look reasonable

  12. The ATLAS(3D) project : I. A volume-limited sample of 260 nearby early-type galaxies: science goals and selection criteria

    NARCIS (Netherlands)

    Cappellari, Michele; Emsellem, Eric; Krajnovic, Davor; McDermid, Richard M.; Scott, Nicholas; Kleijn, G. A. Verdoes; Young, Lisa M.; Alatalo, Katherine; Bacon, R.; Blitz, Leo; Bois, Maxime; Bournaud, Frederic; Bureau, M.; Davies, Roger L.; Davis, Timothy A.; de Zeeuw, P. T.; Duc, Pierre-Alain; Khochfar, Sadegh; Kuntschner, Harald; Lablanche, Pierre-Yves; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Serra, Paolo; Weijmans, Anne-Marie

    2011-01-01

    The ATLAS3D project is a multiwavelength survey combined with a theoretical modelling effort. The observations span from the radio to the millimetre and optical, and provide multicolour imaging, two-dimensional kinematics of the atomic (H i), molecular (CO) and ionized gas (H beta, [O iii] and [N i

  13. Improved LIBS limit of detection of Be, Mg, Si, Mn, Fe and Cu in aluminum alloy samples using a portable Echelle spectrometer with ICCD camera

    Science.gov (United States)

    Mohamed, Walid Tawfik Y.

    2008-02-01

    Laser-induced breakdown spectroscopy (LIBS) is a laser-based technique that can provide non-intrusive, qualitative and quantitative measurement of metals in various environments. LIBS uses the plasma generated by a high-energy laser beam to prepare and excite the sample in one step. In the present work, LIBS has been applied to perform elemental analysis of six trace elements simultaneously in aluminum alloy targets. The plasma is generated by focusing a pulsed Nd:YAG laser on the target in air at atmospheric pressure. LIBS limit of detection (LOD) is affected by many experimental parameters such as interferences, self-absorption, spectral overlap and matrix effect. We aimed to improve the LIBS LOD by optimizing these experimental parameters as possible. In doing so, a portable Echelle spectrometer with intensified CCD camera was used to detect the LIBS plasma emission. This advanced Echelle spectrometer provides a constant spectral resolution (CSR) of 7500 corresponding to 4 pixels FWHM over a wavelength range 200-1000 nm displayable in a single spectrum. Then, the calibration curves for iron, beryllium, magnesium, silicon, manganese and copper as minor elements were achieved with linear regression coefficients between 98-99% on average in aluminum standard sample alloys. New LOD values were achieved in the ppm range with high precision (RSD 3-8%). From the application view point, improving LIBS LOD is very important in the on-line industrial process control to follow-up multi-elements for the correct alloying in metals.

  14. Household vacuum cleaners vs. the high-volume surface sampler for collection of carpet dust samples in epidemiologic studies of children

    Directory of Open Access Journals (Sweden)

    Buffler Patricia A

    2008-02-01

    Full Text Available Abstract Background Levels of pesticides and other compounds in carpet dust can be useful indicators of exposure in epidemiologic studies, particularly for young children who are in frequent contact with carpets. The high-volume surface sampler (HVS3 is often used to collect dust samples in the room in which the child had spent the most time. This method can be expensive and cumbersome, and it has been suggested that an easier method would be to remove dust that had already been collected with the household vacuum cleaner. However, the household vacuum integrates exposures over multiple rooms, some of which are not relevant to the child's exposure, and differences in vacuuming equipment and practices could affect the chemical concentration data. Here, we compare levels of pesticides and other compounds in dust from household vacuums to that collected using the HVS3. Methods Both methods were used in 45 homes in California. HVS3 samples were collected in one room, while the household vacuum had typically been used throughout the home. The samples were analyzed for 64 organic compounds, including pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls (PCBs, using GC/MS in multiple ion monitoring mode; and for nine metals using conventional microwave-assisted acid digestion combined with ICP/MS. Results The methods agreed in detecting the presence of the compounds 77% to 100% of the time (median 95%. For compounds with less than 100% agreement, neither method was consistently more sensitive than the other. Median concentrations were similar for most analytes, and Spearman correlation coefficients were 0.60 or higher except for allethrin (0.15 and malathion (0.24, which were detected infrequently, and benzo(kfluoranthene (0.55, benzo(apyrene (0.55, PCB 105 (0.54, PCB 118 (0.54, and PCB 138 (0.58. Assuming that the HVS3 method is the "gold standard," the extent to which the household vacuum cleaner method yields relative risk

  15. Estimation of multivariate detection limits of four quality parameters in licorice using MEMS–NIR spectrometry coupled with two sampling accessories

    Directory of Open Access Journals (Sweden)

    Zhisheng Wu

    2015-09-01

    Full Text Available In this work, multivariate detection limits (MDL estimator was obtained based on the micro-electro-mechanical systems–near infrared (MEMS–NIR technology coupled with two sampling accessories to assess the detection capability of four quality parameters (glycyrrhizic acid, liquiritin, liquiritigenin and isoliquiritin in licorice from different geographical regions. 112 licorice samples were divided into two parts (calibration set and prediction set using Kennard–Stone (KS method. Four quality parameters were measured using high-performance liquid chromatography (HPLC method according to Chinese pharmacopoeia and previous studies. The MEMS–NIR spectra were acquired from fiber optic probe (FOP and integrating sphere, then the partial least squares (PLS model was obtained using the optimum processing method. Chemometrics indicators have been utilized to assess the PLS model performance. Model assessment using chemometrics indicators is based on relative mean prediction error of all concentration levels, which indicated relatively low sensitivity for low-content analytes (below 1000 parts per million (ppm. Therefore, MDL estimator was introduced with alpha error and beta error based on good prediction characteristic of low concentration levels. The result suggested that MEMS–NIR technology coupled with fiber optic probe (FOP and integrating sphere was able to detect minor analytes. The result further demonstrated that integrating sphere mode (i.e., MDL0.05,0.05, 0.22% was more robust than FOP mode (i.e., MDL0.05,0.05, 0.48%. In conclusion, this research proposed that MDL method was helpful to determine the detection capabilities of low-content analytes using MEMS–NIR technology and successful to compare two sampling accessories.

  16. Capabilities and limitations of dispersive liquid-liquid microextraction with solidification of floating organic drop for the extraction of organic pollutants from water samples.

    Science.gov (United States)

    Vera-Avila, Luz E; Rojo-Portillo, Tania; Covarrubias-Herrera, Rosario; Peña-Alvarez, Araceli

    2013-12-17

    Dispersive liquid-liquid microextraction with solidification of floating organic drop (DLLME-SFO) is one of the most interesting sample preparation techniques developed in recent years. Although several applications have been reported, the potentiality and limitations of this simple and rapid extraction technique have not been made sufficiently explicit. In this work, the extraction efficiency of DLLME-SFO for pollutants from different chemical families was determined. Studied compounds include: 10 polycyclic aromatic hydrocarbons, 5 pesticides (chlorophenoxy herbicides and DDT), 8 phenols and 6 sulfonamides, thus, covering a large range of polarity and hydrophobicity (LogKow 0-7, overall). After optimization of extraction conditions using 1-dodecanol as extractant, the procedure was applied for extraction of each family from 10-mL spiked water samples, only adjusting sample pH as required. Absolute recoveries for pollutants with LogKow 3-7 were >70% and recovery values within this group (18 compounds) were independent of structure or hydrophobicity; the precision of recovery was very acceptable (RSD0.995). Extraction recoveries for pollutants with LogKow 1.46-2.8 were in the range 13-62%, directly depending on individual LogKow values; however, good linearity (r(2)>0.993) and precision (RSD<6.5%) were also demonstrated for these polar solutes, despite recovery level. DLLME-SFO with 1-dodecanol completely failed for extraction of compounds with LogKow≤1 (sulfa drugs), other more polar extraction solvents (ionic liquids) should be explored for highly hydrophilic pollutants. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. New method for rapid solid-phase extraction of large-volume water samples and its application to non-target screening of North Sea water for organic contaminants by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Weigel, S; Bester, K; Hühnerfuss, H

    2001-03-30

    A method has been developed that allows the solid-phase extraction of microorganic compounds from large volumes of water (10 l) for non-target analysis of filtered seawater. The filtration-extraction system is operated with glass fibre filter candles and the polymeric styrene-divinylbenzene sorbent SDB-1 at flow-rates as high as 500 ml/min. Recovery studies carried out for a couple of model substances covering a wide range of polarity and chemical classes revealed a good performance of the method. Especially for polar compounds (log Kow 3.3-0.7) quantitative recovery was achieved. Limits of detection were between 0.1 and 0.7 ng/l in the full scan mode of the MS. The suitability of the method for the analysis of marine water samples is demonstrated by the non-target screening of water from the German Bight for the presence of organic contaminants. In the course of this screening a large variety of substances was identified including pesticides, industrial chemicals and pharmaceuticals. For some of the identified compounds their occurrence in marine ecosystems has not been reported before, such as dichloropyridines, carbamazepine, propyphenazone and caffeine.

  18. Use of Lagrangian transport models and Sterilized High Volume Sampling to pinpoint the source region of Kawasaki disease and determine the etiologic agent

    Science.gov (United States)

    Curcoll Masanes, Roger; Rodó, Xavier; Anton, Jordi; Ballester, Joan; Jornet, Albert; Nofuentes, Manel; Sanchez-Manubens, Judith; Morguí, Josep-Anton

    2015-04-01

    Kawasaki disease (KD) is an acute, coronary artery vasculitis of young children, and still a medical mystery after more than 40 years. A former study [Rodó et al. 2011] demonstrated that certain patterns of winds in the troposphere above the earth's surface flowing from Asia were associated with the times of the annual peak in KD cases and with days having anomalously high numbers of KD patients. In a later study [Rodó et al. 2014], we used residence times from an Air Transport Model to pinpoint the source region for KD. Simulations were generated from locations spanning Japan from days with either high or low KD incidence. In order to cope with stationarity of synoptic situations, only trajectories for the winter months, when there is the maximum in KD cases, were considered. Trajectories traced back in time 10 days for each dataset and location were generated using the flexible particle Lagrangian dispersion model (FLEXPART Version 8.23 [Stohl et al. 2005]) run in backward mode. The particles modeled were air tracers, with 10,000 particles used on each model run. The model output used was residence time, with an output grid of 0.5° latitude × longitude and a time resolution of 3 h. The data input used for the FLEXPART model was gridded atmospheric wind velocity from the European Center for Medium-Range Weather Forecasts Re-Analysis (ERA-Interim at 1°). Aggregates of winter period back-trajectories were calculated for three different regions of Japan. A common source of wind air masses was located for periods with High Kawasaki disease. Knowing the trajectories of winds from the air transport models, a sampling methodology was developed in order to capture the possible etiological agent or other tracers that could have been released together. This methodology is based on the sterilized filtering of high volumes of the transported air at medium tropospheric levels by aircraft sampling and a later analyze these filters with adequate techniques. High purity

  19. A novel ionic liquid/micro-volume back extraction procedure combined with flame atomic absorption spectrometry for determination of trace nickel in samples of nutritional interest

    Energy Technology Data Exchange (ETDEWEB)

    Dadfarnia, Shayesteh, E-mail: sdadfarnia@yazduni.ac.ir [Department of Chemistry, Faculty of Science, Yazd University, 89195/74, Yazd (Iran, Islamic Republic of); Haji Shabani, Ali Mohammad; Shirani Bidabadi, Mahboubeh; Jafari, Abbas Ali [Department of Chemistry, Faculty of Science, Yazd University, 89195/74, Yazd (Iran, Islamic Republic of)

    2010-01-15

    A simple, highly sensitive and environment-friendly method for the determination of trace amount of nickel ion in different matrices is proposed. In the preconcentration step, the nickel from 10 mL of an aqueous solution was extracted into 500 {mu}L of ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C{sub 4}MIM][PF{sub 6}], containing PAN as complexing agent. Subsequently, the PAN complex was back-extracted into 250 {mu}L of nitric acid solution, and 100 {mu}L of it was analyzed by flow injection flame atomic absorption spectrometry (FI-FAAS). The main parameter influencing the extraction and determination of nickel, such as pH, concentration of PAN, extraction time and temperature, ionic strength, and concentration of stripping acid solution, were optimized. An enhancement factor of 40.2 was achieved with 25 mL sample. The limit of detection (LOD) and quantification obtained under the optimum conditions were 12.5 and 41.0 {mu}g L{sup -1}, respectively. To validate the proposed methods two certified reference materials 681-I and BCR No. 288 were analyzed and the results were in good agreement with the certified values. The proposed method was successfully applied to determination of nickel in water samples, rice flour and black tea.

  20. A novel ionic liquid/micro-volume back extraction procedure combined with flame atomic absorption spectrometry for determination of trace nickel in samples of nutritional interest.

    Science.gov (United States)

    Dadfarnia, Shayesteh; Shabani, Ali Mohammad Haji; Bidabadi, Mahboubeh Shirani; Jafari, Abbas Ali

    2010-01-15

    A simple, highly sensitive and environment-friendly method for the determination of trace amount of nickel ion in different matrices is proposed. In the preconcentration step, the nickel from 10 mL of an aqueous solution was extracted into 500 microL of ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C(4)MIM][PF(6)], containing PAN as complexing agent. Subsequently, the PAN complex was back-extracted into 250 microL of nitric acid solution, and 100 microL of it was analyzed by flow injection flame atomic absorption spectrometry (FI-FAAS). The main parameter influencing the extraction and determination of nickel, such as pH, concentration of PAN, extraction time and temperature, ionic strength, and concentration of stripping acid solution, were optimized. An enhancement factor of 40.2 was achieved with 25 mL sample. The limit of detection (LOD) and quantification obtained under the optimum conditions were 12.5 and 41.0 microg L(-1), respectively. To validate the proposed methods two certified reference materials 681-I and BCR No. 288 were analyzed and the results were in good agreement with the certified values. The proposed method was successfully applied to determination of nickel in water samples, rice flour and black tea.

  1. Capillary sample

    Science.gov (United States)

    ... several times a day using capillary blood sampling. Disadvantages to capillary blood sampling include: Only a limited ... do not constitute endorsements of those other sites. Copyright 1997-2017, A.D.A.M., Inc. Duplication ...

  2. Droplet sampling of an oil-based and two water-based antievaporant ultra-low volume insecticide formulations using Teflon- and magnesium oxide-coated slides.

    Science.gov (United States)

    Chaskopoulou, Alexandra; Latham, Mark D; Pereira, Roberto M; Koehler, Philip G

    2013-06-01

    We estimated the diameters below which 50% and 90% of the volume of droplets exist (Dv50 and Dv90, respectively) of 1 oil-based (Permanone 30-30) and 2 water-based (AquaReslin, Aqua-K-Othrine) antievaporant aerosols (with the Film Forming Aqueous Spray Technology [FFAST]) using Teflon- and magnesium oxide (MgO)-coated slides and determined whether the aging of the droplets on the slides (up to 60 min) exhibited any significant effect on Dv50 and Dv90 calculations. There were no significant differences in either Dv50 or Dv90 estimates on MgO-coated slides at 0 min and 60 min for all 3 products tested. On Teflon-coated slides, the only product that showed significant difference between 0 min and 60 min in both Dv50 and Dv90 estimates was Aqua-K-Othrine, perhaps due to a difference in formulation components. Specifically, both values corresponding to Dv50 and Dv90 at 60 min decreased by approximately 50% when compared to the values at 0 min. For the other 2 products, AquaReslin and Permanone, aging of droplets on Teflon up to 60 min did not have any significant effect on Dv50 and Dv90 values. To further investigate the behavior of Aqua-K-Othrine droplets on Teflon-coated slides we observed the droplets immediately after spraying and at 10-min intervals under different conditions of temperature and humidity. The majority of the shrinkage occurred within the 1st 10 min after impaction on the slides under all conditions tested. So in most field situations where slides are read several hours or days after collection, this shrinkage would not be observed. The MgO-coated slides should be the preferred field method for sampling droplets of Aqua-K-Othirne with the FFAST antievaporant technology.

  3. Strengths and limitations of actuarial prediction of criminal reoffence in a German prison sample: a comparative study of LSI-R, HCR-20 and PCL-R.

    Science.gov (United States)

    Dahle, Klaus-Peter

    2006-01-01

    Unlike many other countries, for many years, Germany disregarded structured instruments for assessing the risk of criminal reoffence. However, this negative attitude now seems to be gradually changing. An increasing number of contributions regarding structured instruments have been published in the German literature in the last years, and some instruments have already found their way into practice. However, studies that systematically examine the applicability of the mostly Anglo-American instruments to German criminals are still lacking. Therefore, the major objective of the current study was to test some internationally established procedures in a larger unselected sample from the German penal system. The following were included in the study: the Level of Service Inventory - Revised (LSI-R), the HCR-20 Scheme, and the Psychopathy Checklist - Revised (PCL-R). On the whole, the instruments proved to be applicable to German criminals with only a few adaptations to the German situation, and they achieved a predictive accuracy comparable to the values reported internationally. However, there were only minor differences in the predictive performance between the measures. Moreover, some basic limitations became apparent. Firstly, we found quite high percentages of criminals with medium scores and a correspondingly ambiguous prognosis. Furthermore, the predictive accuracy seemed to be dependent on demographic, criminological and psychopathological characteristics of the offenders. Finally, the instruments appeared to only partially utilize the empirical store of knowledge available regarding factors influencing the recidivism of criminals, since even a simple predictive model that only added a few further aspects besides the tested instruments (e. g. treatment yes or no) achieved systematically better predictions than the instruments alone. Altogether, the tested measures turned out to be useful instruments for risk assessments and may be conducive for a more systemized

  4. High Voltage Test Apparatus for a Neutron EDM Experiment and Lower Limit on the Dielectric Strength of Liquid Helium at Large Volumes

    CERN Document Server

    Long, J C; Boissevain, J G; Clark, D J; Cooper, M D; Gómez, J J; Lamoreaux, S K; Mischke, R E; Penttila, S I

    2006-01-01

    A new search for a permanent electric dipole moment (EDM) of the neutron is underway using ultracold neutrons produced and held in a bath of superfluid helium. Attaining the target sensitivity requires maintaining an electric field of several tens of kilovolts per centimeter across the experimental cell, which is nominally 7.5 cm wide and will contain about 4 liters of superfluid. The electrical properties of liquid helium are expected to be sufficient to meet the design goals, but little is known about these properties for volumes and electrode spacings appropriate to the EDM experiment. Furthermore, direct application of the necessary voltages from an external source to the experimental test cell is impractical. An apparatus to amplify voltages in the liquid helium environment and to test the electrical properties of the liquid for large volumes and electrode spacings has been constructed. The device consists of a large-area parallel plate capacitor immersed in a 200 liter liquid helium dewar. Preliminary r...

  5. Recovery Efficiency, False Negative Rate, and Limit of Detection Performance of a Validated Macrofoam-Swab Sampling Method with Low Surface Concentrations of Two Bacillus anthracis Surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hutchison, Janine R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Deatherage Kaiser, Brooke L [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sydor, Michael A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Barrett, Christopher A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-31

    The performance of a macrofoam-swab sampling method was evaluated using Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus Nakamura (BG) spores applied at nine low target amounts (2-500 spores) to positive-control plates and test coupons (2 in. × 2 in.) of four surface materials (glass, stainless steel, vinyl tile, and plastic). Test results from cultured samples were used to evaluate the effects of surrogate, surface concentration, and surface material on recovery efficiency (RE), false negative rate (FNR), and limit of detection. For RE, surrogate and surface material had statistically significant effects, but concentration did not. Mean REs were the lowest for vinyl tile (50.8% with BAS, 40.2% with BG) and the highest for glass (92.8% with BAS, 71.4% with BG). FNR values ranged from 0 to 0.833 for BAS and 0 to 0.806 for BG, with values increasing as concentration decreased in the range tested (0.078 to 19.375 CFU/cm2, where CFU denotes ‘colony forming units’). Surface material also had a statistically significant effect. A FNR-concentration curve was fit for each combination of surrogate and surface material. For both surrogates, the FNR curves tended to be the lowest for glass and highest for vinyl title. The FNR curves for BG tended to be higher than for BAS at lower concentrations, especially for glass. Results using a modified Rapid Viability-Polymerase Chain Reaction (mRV-PCR) analysis method were also obtained. The mRV-PCR results and comparisons to the culture results will be discussed in a subsequent report.

  6. Limited sampling strategy of partial area-under-the-concentration-time-curves to estimate midazolam systemic clearance for cytochrome P450 3A phenotyping

    Science.gov (United States)

    Masters, Joanna C.; Harano, Denise M.; Greenberg, Howard E.; Tsunoda, Shirley M.; Jang, In-Jin; Ma, Joseph D.

    2014-01-01

    Objective Intravenous (IV) midazolam is the preferred cytochrome P450 (CYP) 3A probe for phenotyping, with systemic clearance (CL) estimating hepatic CYP3A activity. A limited sampling strategy was conducted to determine if partial area-under-the-concentration-time-curves (AUCs) could reliably estimate midazolam systemic CL during conditions of CYP3A baseline activity, inhibition and induction/activation. Methods Midazolam plasma concentrations during CYP3A baseline (n=93), inhibition (n=40), and induction/activation (n=33) were obtained from seven studies in healthy adults. Non-compartmental analysis determined observed CL (CLobs) and partial AUCs. Linear regression equations were derived from partial AUCs to estimate CL (CLpred) during CYP3A baseline, inhibition and induction/activation. Pre-established criterion for linear regression analysis was r2 ≥0.9. CLpred was compared to CLobs, and relative bias and precision were assessed using percent mean prediction error (%MPE) and percent mean absolute error (%MAE). Results During CYP3A baseline and inhibition, all evaluated partial AUCs failed to meet criterion of r2 ≥0.9 and/or %MAE midazolam partial AUC0–1, AUC0–2, and AUC0–4 reliably estimated systemic CL, and consequently hepatic CYP3A activity in healthy adults. PMID:25004135

  7. Hippocampal volume is positively associated with behavioural inhibition (BIS) in a large community-based sample of mid-life adults: the PATH through life study.

    Science.gov (United States)

    Cherbuin, Nicolas; Windsor, Tim D; Anstey, Kaarin J; Maller, Jerome J; Meslin, Chantal; Sachdev, Perminder S

    2008-09-01

    The fields of personality research and neuropsychology have developed with very little overlap. Gray and McNaughton were among the first to recognize that personality traits must have neurobiological correlates and developed models relating personality factors to brain structures. Of particular note was their description of associations between conditioning, inhibition and activation of behaviours, and specific neural structures such as the hippocampus, amygdala and the prefrontal cortex. The aim of this study was to determine whether personality constructs representing the behavioural inhibition and activation systems (BIS/BAS) were associated with volumetric measures of the hippocampus and amygdala in humans. Amygdalar and hippocampal volumes were measured in 430 brain scans of cognitively intact community-based volunteers. Linear associations between brain volumes and the BIS/BAS measures were assessed using multiple regression, controlling for age, sex, education, intra-cranial and total brain volume. Results showed that hippocampal volumes were positively associated with BIS sensitivity and to a lesser extent with BAS sensitivity. No association was found between amygdalar volume and either the BIS or BAS. These findings add support to the model of Gray and McNaughton, which proposes a role of the hippocampus in the regulation of defensive/approach behaviours and trait anxiety but suggest an absence of associations between amygdala volume and BIS/BAS measures.

  8. Pressure-volume loop-derived cardiac indices during dobutamine stress: a step towards understanding limitations in cardiac output in children with hypoplastic left heart syndrome.

    Science.gov (United States)

    Wong, James; Pushparajah, Kuberan; de Vecchi, Adelaide; Ruijsink, Bram; Greil, Gerald F; Hussain, Tarique; Razavi, Reza

    2017-03-01

    Children with a single systemic right ventricle, such as in hypoplastic left heart syndrome (HLHS), frequently experience reduced exercise capacity. Elucidating the causes could help with optimising treatment strategies. Prospective data from 10 consecutive symptomatic patients with HLHS undergoing clinical cardiac magnetic resonance with catheterisation (XMR) were analysed. Mean age 8.6years (range 3.5-11.6years), mean time since Fontan completion 5.5years. MR-compatible catheters were placed in the systemic right ventricle and branch pulmonary arteries to record pressures at rest, with dobutamine infusion at 10mcg/kg/min and at 20mcg/kg/min. Cine short-axis stacks of the ventricle were performed at each condition and used to construct pressure-volume loops. Compared to rest, cardiac index increased with low-dose dobutamine (pstress despite a further, albeit, blunted rise in heart rate (p=0.002). A fall in stroke volume occurred (p=0.014) despite good contractility (74% increase, p=0.045) and a well-coupled ventriculo-arterial ratio. End-diastolic pressure and early active relaxation, markers of diastolic function, were normal at rest. However, preload fell at peak stress (pstress, coinciding with a fall in preload. Markers of systolic and diastolic function remained normal. Failure to adequately fill the ventricle implies a ceiling of maximal flow through the Fontan circuit despite low PVR. Copyright © 2016. Published by Elsevier B.V.

  9. On the fairness of the main galaxy sample of SDSS

    Institute of Scientific and Technical Information of China (English)

    Ke-Lai Meng; Bin Ma; Jun Pan; Long-Long Feng

    2011-01-01

    Flux-limited and volume-limited galaxy samples are constructed from the Sloan Digital Sky Survey (SDSS) data releases DR4, DR6 and DR7 for statistical analysis. The two-point correlation functions ξ(s), monopole of three-point correlation functions ζ0, projected two-point correlation function Wp and pairwise velocity dispersion σ12 are measured to test if galaxy samples are fair for these statistics. We find that with the increment of sky coverage of subsequent data releases in SDSS,ξ(s) of the flux-limited sample is extremely robust and insensitive to local structures at low redshift. However, for volume-limited samples fainter than L* at large scales s >~ 10 h-1 Mpc, the deviation of ξ(s) from different SDSS data releases (DR7, DR6 and DR4) increases with the increment of absolute magnitude. The case of ζ0(s) is similar to that of ξ(s). In the weakly nonlinear regime, there is no agreement between ζ0 of different data releases in all luminosity bins. Furthermore, Wp of volume-limited samples of DR7 in luminosity bins fainter than -Mr,0.1 = [18.5, 19.5] are significantly larger and σ12 of the two faintest volume-limited samples of DR7 display a very different scale dependence than results from DR4 and DR6. Our findings call for caution in understanding clustering analysis results of SDSS faint galaxy samples and higher order statistics of SDSS volume-limited samples in the weakly nonlinear regime. The first zero-crossing points of ξ(s) from volume-limited samples are also investigated and discussed.

  10. 7 CFR 42.111 - Sampling plans for reduced condition of container inspection, Tables III and III-A; and limit...

    Science.gov (United States)

    2010-01-01

    ... Inspection Code Lot size ranges—Number of containers in lot Type of plan Sample size Acceptable quality... 7 Agriculture 2 2010-01-01 2010-01-01 false Sampling plans for reduced condition of container... Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE...

  11. The influence of sample volume applied to the Makler sperm counting chamber upon the measured concentration of latex beads:A multi-centre study

    Institute of Scientific and Technical Information of China (English)

    Melanie Walls; Cherise Mooy; Patrick Mohan; Sally Catt; Matthew Wiltshire; Hassan W Bakos; Mary Whyte; Phillip Matson; Emily Zuvela; Cheryl Ayres; Deborah Sherrin; Asma Chhotani; Liz Butler; Kelli Peirce; Jenny Krapez; Renae Parker

    2012-01-01

    Objective:To undertake a multi-centre study to maximize the number ofMakler chambers used.Methods:A total of15 laboratories participated with31Makler chambers.A suspension of latex beads was prepared to a concentration of20 millions per milliliter, and0.5 mL aliquots distributed to each participating laboratory.They measured the concentration on theirMakler chamber(s) used for routine semen analysis by adding3,4,5,7 and10µL volumes of bead suspension to the chamber.Results:There was no difference in within-chamber analysis of the bead concentration according to the volume of bead suspension applied within the range of 3-10µL(F4,14=2.634,P=0.056).However, the between-chamber effects were significantly different (F30,124=4.937,P=0.000), and24/31(77.5%) chambers tested had an average bias>10% compared to the target bead concentration.Conclusions:A volume of3-10µL added toMakler counting chambers does not influence the concentration measured of latex beads, but the between-chamber variability and positive bias seen would suggest that other sources of error are present which are yet to be identified.

  12. Lowering detection limits for 1,2,3-trichloropropane in water using solid phase extraction coupled to purge and trap sample introduction in an isotope dilution GC-MS method.

    Science.gov (United States)

    Liao, Wenta; Ghabour, Miriam; Draper, William M; Chandrasena, Esala

    2016-09-01

    Purge and trap sample introduction (PTI) has been the premier sampling and preconcentration technique for gas chromatographic determination of volatile organic compounds (VOCs) in drinking water for almost 50 years. PTI affords sub parts-per-billion (ppb) detection limits for purgeable VOCs including fixed gases and higher boiling hydrocarbons and halocarbons. In this study the coupling of solid phase extraction (SPE) to PTI was investigated as a means to substantially increase enrichment and lower detection limits for the emerging contaminant, 1,2,3-trichloropropane (TCP). Water samples (500 mL) were dechlorinated, preserved with a biocide, and spiked with the isotope labeled internal standard, d5-TCP. The entire 500 mL sample was extracted with activated carbon or carbon molecular sieve SPE cartridges, and then eluted with dichloromethane -- excess solvent was removed in a nitrogen evaporator and diethylene glycol "keeper" remaining was dispersed in 5 mL of water for PTI GC-MS analysis. The experimental Method Detection Limit (MDL) for TCP was 0.11 ng/L (ppt) and accuracy was 95-103% in sub-ppt determinations. Groundwater samples including impaired California sources and treated water (n = 21) were analyzed with results ranging from below the method reporting limit (0.30 ng/L) to > 250 ng/L. Coupling of SPE with PTI may provide similar reductions in detection limits for other VOCs with appropriate physical-chemical properties.

  13. Method to Solve the Problem of the Radioactivity Detection in Environmental Samples. Characteristic Limits; Metodos para la Resolucion del Problema de la Detecfcion de Radiactividad en Muestras Ambientales. Limites Caracteristicos

    Energy Technology Data Exchange (ETDEWEB)

    Gasco, C.; Martinez, M.; Heras, M.

    2009-07-21

    The problem of the detection or when the radioactivity can be considered as higher than the background using different measurement techniques has been the objective of several statistical studies and controversies. The detection limit and the critical limit were studied by Currie in year 1968 and used by radiochemistry laboratories considering different ways of calculation that introduced confusion and not correct implementations. In the last few years, and due to the increasing number of standardization processes on the field of radioactivity and accreditation, several international institutions have chosen to unify the criteria for using common determination of detection limits. The most used methods are those developed by MARLAP and International Standard Organization ISO (Standard-11929). In this report are summarised both standards doing a comparative study and giving some examples of how to apply these limits. In same cases, little differences in the uncertainty calculation have been observed but the final results have been concordant. A deeply study of these standards can be done consulting the web page of the American Labs that developed MARLAP or buying the original ISO standard ISO-11929 recently approved (2009). (Author) 17 refs.

  14. Improving the Phosphoproteome Coverage for Limited Sample Amounts Using TiO2-SIMAC-HILIC (TiSH) Phosphopeptide Enrichment and Fractionation

    DEFF Research Database (Denmark)

    Engholm-Keller, Kasper; Larsen, Martin R

    2016-01-01

    Obtaining high phosphoproteome coverage requires specific enrichment of phosphorylated peptides from the often extremely complex peptide mixtures generated by proteolytic digestion of biological samples, as well as extensive chromatographic fractionation prior to liquid chromatography-tandem mass...

  15. The Role of Neighborhood Safety in Recovery from Mobility Limitations: Findings from a National Sample of Older Americans (1996-2008).

    Science.gov (United States)

    Latham, Kenzie; Clarke, Philippa J

    2013-07-01

    Prior research has documented a link between perceived neighborhood safety and functional limitations including incident mobility limitation, yet no research has explored the association between perceived neighborhood safety and recovery from functional limitations. This study investigates whether perceived neighborhood safety independently predicts recovery. Using longitudinal data from the Health and Retirement Study (HRS) (1996-2008), discrete-time event history models with multiple competing events were estimated using multinomial logistic regression. Robust standard errors were used to adjust for clustering. In the unadjusted model, the odds ratio for recovery from mobility limitations was 1.22 (CI: 1.17, 1.27) for respondents reporting greater neighborhood safety, while, in the fully adjusted model, the odds ratio was 1.11 (CI: 1.05, 1.17). Even after controlling for sociodemographic characteristics and numerous health risk factors, perceived neighborhood safety was a robust predictor of mobility limitation recovery. This research provides further evidence that environmental factors shape functional health outcomes including recovery.

  16. Evaluation of 5-Fluorouracil Pharmacokinetics in Cancer Patients with a c.1905+1G > A Mutation in DPYD by Means of a Bayesian Limited Sampling Strategy

    NARCIS (Netherlands)

    van Kuilenburg, Andre B. P.; Haeusler, Peter; Schalhorn, Andreas; Tanck, Michael W. T.; Proost, Johannes H.; Terborg, Christoph; Behnke, Detlev; Schwabe, Wolfgang; Jabschinsky, Kati; Maring, Jan Gerard

    2012-01-01

    Background and Objective: Dihydropyrimidine dehydrogenase (DPD) is the initial enzyme in the catabolism of 5-fluorouracil (5FU) and DPD deficiency is an important pharmacogenetic syndrome. So far, only very limited information is available regarding the pharmacokinetics of 5FU in patients with a (pa

  17. Improving the Phosphoproteome Coverage for Limited Sample Amounts Using TiO2-SIMAC-HILIC (TiSH) Phosphopeptide Enrichment and Fractionation.

    Science.gov (United States)

    Engholm-Keller, Kasper; Larsen, Martin R

    2016-01-01

    Obtaining high phosphoproteome coverage requires specific enrichment of phosphorylated peptides from the often extremely complex peptide mixtures generated by proteolytic digestion of biological samples, as well as extensive chromatographic fractionation prior to liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Due to the sample loss resulting from fractionation, this procedure is mainly performed when large quantities of sample are available. To make large-scale phosphoproteomics applicable to smaller amounts of protein we have recently combined highly specific TiO2-based phosphopeptide enrichment with sequential elution from immobilized metal affinity chromatography (SIMAC) for fractionation of mono- and multi-phosphorylated peptides prior to capillary scale hydrophilic interaction liquid chromatography (HILIC) based fractionation of monophosphorylated peptides. In the following protocol we describe the procedure step by step to allow for comprehensive coverage of the phosphoproteome utilizing only a few hundred micrograms of protein.

  18. A study of toxic emissions from a coal-fired power plant utilizing the SNOX innovative clean coal technology demonstration. Volume 1, Sampling/results/special topics: Final report

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    This study was one of a group of assessments of toxic emissions from coal-fired power plants, conducted for DOE during 1993. The motivation for those assessments was the mandate in the 1990 Clean Air Act Amendments that a study be made of emissions of hazardous air pollutants (HAPs) from electric utilities. The report is organized in two volumes. Volume 1: Sampling describes the sampling effort conducted as the basis for this study; Results presents the concentration data on HAPs in the several power plant streams, and reports the results of evaluations and calculations conducted with those data; and Special Topics report on issues such as comparison of sampling methods and vapor/solid distributions of HAPs. Volume 2: Appendices include quality assurance/quality control results, uncertainty analysis for emission factors, and data sheets. This study involved measurements of a variety of substances in solid, liquid, and gaseous samples from input, output, and process streams at the Innovative Clean Coal Technology Demonstration (ICCT) of the Wet Sulfuric Acid-Selective Catalytic Reduction (SNOX) process. The SNOX demonstration is being conducted at Ohio Edison`s Niles Boiler No. 2 which uses cyclone burners to burn bituminous coal. A 35 megawatt slipstream of flue gas from the boiler is used to demonstrate SNOX. The substances measured at the SNOX process were the following: 1. Five major and 16 trace elements, including mercury, chromium, cadmium, lead, selenium, arsenic, beryllium, and nickel; 2. Acids and corresponding anions (HCl, HF, chloride, fluoride, phosphate, sulfate); 3. Ammonia and cyanide; 4. Elemental carbon; 5. Radionuclides; 6. Volatile organic compounds (VOC); 7. Semi-volatile compounds (SVOC) including polynuclear aromatic hydrocarbons (PAH); and 8. Aldehydes.

  19. Temperature dependent low-field measurements of the magnetocaloric ΔT with sub-mK resolution in small volume and thin film samples

    Energy Technology Data Exchange (ETDEWEB)

    Döntgen, J.; Rudolph, J. [Arbeitsgruppe Spektroskopie der kondensierten Materie, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany); Gottschall, T.; Gutfleisch, O. [Institut für Materialwissenschaft, TU Darmstadt, 64287 Darmstadt (Germany); Salomon, S. [Institut für Werkstoffe, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany); Ludwig, A. [Institut für Werkstoffe, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany); Materials Research Department, Ruhr-Universität Bochum, 44780 Bochum (Germany); Hägele, D., E-mail: daniel.haegele@rub.de [Arbeitsgruppe Spektroskopie der kondensierten Materie, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany); Materials Research Department, Ruhr-Universität Bochum, 44780 Bochum (Germany)

    2015-01-19

    We present temperature dependent ΔT measurements of the magnetocaloric effect in a thin film sample of Gd, employing magnetomodulation and detection of thermal radiation. A bulk sample of the metamagnetic material LaFe{sub 11.05}Co{sub 0.91}Si{sub 1.04} shows a strong broadening of the ΔT peak for increasing field amplitudes between 4 and 45 mT. Bulk Gd in comparison shows only a weak broadening. All investigated samples exhibit a clear quadratic dependence of ΔT on the external field H{sub ext} at the ΔT peak maximum, contrary to earlier predictions. An analytic expression is derived that interpolates between the H{sub ext}{sup 2}-behavior at low and the well-known H{sub ext}{sup 2/3}-behavior at high fields.

  20. The Effect of Limited Sample Sizes on the Accuracy of the Estimated Scaling Parameter for Power-Law-Distributed Solar Data

    CERN Document Server

    D'Huys, Elke; Seaton, Daniel B; Poedts, Stefaan

    2016-01-01

    Many natural processes exhibit power-law behavior. The power-law exponent is linked to the underlying physical process and therefore its precise value is of interest. With respect to the energy content of nanoflares, for example, a power-law exponent steeper than 2 is believed to be a necessary condition to solve the enigmatic coronal heating problem. Studying power-law distributions over several orders of magnitudes requires sufficient data and appropriate methodology. In this paper we demonstrate the shortcomings of some popular methods in solar physics that are applied to data of typical sample sizes. We use synthetic data to study the effect of the sample size on the performance of different estimation methods and show that vast amounts of data are needed to obtain a reliable result with graphical methods (where the power-law exponent is estimated by a linear fit on a log-transformed histogram of the data). We revisit published results on power laws for the angular width of solar coronal mass ejections an...

  1. A limited sampling method to estimate methotrexate pharmacokinetics in patients with rheumatoid arthritis using a Bayesian approach and the population data modeling program P-PHARM.

    Science.gov (United States)

    Bressolle, F; Bologna, C; Edno, L; Bernard, J C; Gomeni, R; Sany, J; Combe, B

    1996-01-01

    This paper describes a methodology to calculate methotrexate (MTX) pharmacokinetic parameters after intramuscular administration using two samples and the population parameters. Total and free MTX were measured over a 36-h period in 56 rheumatoid arthritis patients; 14 patients were studied after a two-dose scheme at 15-day intervals. The Hill equation was used to relate the free MTX to the total MTX changes in plasma concentrations, and a two-compartment open model was used to fit the total MTX plasma concentrations. A non-linear mixed effect procedure was used to estimate the population parameters and to explore the interindividual variability in relation to the following covariables: age, weight, height, haemoglobin, erythrocyte sedimentation rate, platelet count, creatinine clearance, rheumatoid factor, C-reactive protein, swelling joint count, and Ritchie's articular index. Population parameters were evaluated for 40 patients using a three-step approach. The population average parameters and the interindividual variabilities expressed as coefficients of variation (CV%) were: CL, 6.94 l center dot h-1 (20.5%); V, 34.8 l (32.2%); k12, 0.0838 h-1 (47.7%); k21, 0.0769 h-1 (61.6%); ka, 4.31 h-1 (58%); Emax, 1.12 mu mol center dot l-1 (19.7%); gamma, 0.932 (12.3%); and EC50, 2.14 mu mol center dot l-1 (27.3%). Thirty additional data sets (16 new patients and 14 patients of the previous population but treated on a separate occasion) were used to evaluate the predictive performance of the population parameters. Twelve blood samples were collected from each individual in order to calculate individual parameters using standard fitting procedures. These values were compared to the ones estimated using a Bayesian approach with population parameters as a priori information together with two samples, selected from the individual observations. The results show that the bias was not statistically different from zero and the precision of these parameters was excellent.

  2. Small Sample Whole-Genome Amplification

    Energy Technology Data Exchange (ETDEWEB)

    Hara, C A; Nguyen, C P; Wheeler, E K; Sorensen, K J; Arroyo, E S; Vrankovich, G P; Christian, A T

    2005-09-20

    Many challenges arise when trying to amplify and analyze human samples collected in the field due to limitations in sample quantity, and contamination of the starting material. Tests such as DNA fingerprinting and mitochondrial typing require a certain sample size and are carried out in large volume reactions; in cases where insufficient sample is present whole genome amplification (WGA) can be used. WGA allows very small quantities of DNA to be amplified in a way that enables subsequent DNA-based tests to be performed. A limiting step to WGA is sample preparation. To minimize the necessary sample size, we have developed two modifications of WGA: the first allows for an increase in amplified product from small, nanoscale, purified samples with the use of carrier DNA while the second is a single-step method for cleaning and amplifying samples all in one column. Conventional DNA cleanup involves binding the DNA to silica, washing away impurities, and then releasing the DNA for subsequent testing. We have eliminated losses associated with incomplete sample release, thereby decreasing the required amount of starting template for DNA testing. Both techniques address the limitations of sample size by providing ample copies of genomic samples. Carrier DNA, included in our WGA reactions, can be used when amplifying samples with the standard purification method, or can be used in conjunction with our single-step DNA purification technique to potentially further decrease the amount of starting sample necessary for future forensic DNA-based assays.

  3. Stellar mass functions of galaxies at 4sample in COSMOS/UltraVISTA: limits on the abundance of very massive galaxies

    CERN Document Server

    Stefanon, Mauro; Muzzin, Adam; Brammer, Gabriel G; Dunlop, James S; Franx, Marijin; Fynbo, Johan P U; Labbe, Ivo; Milvang-Jensen, Bo; van Dokkum, Pieter G

    2014-01-01

    We study the population of massive (i.e., $\\log(M_*/M_\\odot)>11$) galaxies at $44$ galaxies with best fit masses $\\log(M_*/M_\\odot)>11$ by 83% implying a rapid growth of very massive galaxies in the first 1.5 Gyr of cosmic history. From the stellar-mass complete sample, we identify one candidate of a very massive ($\\log(M_*/M_\\odot)\\sim11.5$), quiescent galaxy at $z\\sim5.4$, with MIPS $24\\mu$m detection suggesting the presence of a powerful obscured AGN. Finally, we show that the number of massive galaxies at $4

  4. Carbon Slurry Fuels for Volume Limited Missiles

    Science.gov (United States)

    1979-11-01

    nge being 20 mole percent. The oxygen analyzer is a Beckman Model 776 and .... a maximum range of 25 mole percent. The gas chromatograph is a Carle ...salt can also have an important effec.t on the case of Kcarbon oxidation. For example, Nebel and t.ramer 54 ive a relative lictivity series for lead...1978. 54. Nebel , G. .J, and Cramer, P. L., Ind. Eng. Chem 47m 2393, 1955. - 231 - I APPENDIX C - PREPARATION OF HANSEN PLOTS (1) The first step is

  5. A Serial Sample Loading System: Interfacing Multi-well plates with Microfluidic Devices

    OpenAIRE

    Rane, Tushar D.; Zec, Helena; Wang, Jeff Tza-Huei

    2012-01-01

    There is an increasing demand for novel high-throughput screening (HTS) technologies in the pharmaceutical and biotechnological industries. The robotic sample handling techniques currently used in these industries, although fast, are still limited to operating in multi-well plates with the sample volumes per reaction in the microliter regime. Digital microfluidics offers an alternative for reduction in sample volume consumption for HTS but lacks a reliable technique for transporting large num...

  6. Utilization of long duration high-volume sampling coupled to SPME-GC-MS/MS for the assessment of airborne pesticides variability in an urban area (Strasbourg, France) during agricultural application.

    Science.gov (United States)

    Liaud, Céline; Brucher, Michel; Schummer, Claude; Coscollà, Clara; Wolff, Hélène; Schwartz, Jean-Jacques; Yusà, Vicent; Millet, Maurice

    2016-10-02

    Atmospheric samples have been collected between 14 March and 12 September 2012 on a 2-week basis (15 days of sampling and exchange of traps each 7 days) in Strasbourg (east of France) for the analysis of 43 pesticides. Samples (particle and gas phases) were separately extracted using Accelerated Solvent Extraction (ASE) and pre-concentrated by Solid Phase Micro-Extraction (SPME) before analysis by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Four SPME consecutive injections at distinct temperatures were made in order to increase the sensitivity of detection for the all monitored pesticides. Currently used detected pesticides can be grouped in four classes; those used in maize crops (acetochlor, benoxacor, dicamba, s-metolachlor, pendimethalin, and bromoxynil), in cereal crops (benoxacor, chlorothalonil, fenpropimorph, and propiconazole), in vineyards (tebuconazole), and as herbicides for orchards, meadows of green spaces (2,4-MCPA, trichlopyr). This is in accordance with the diversity of crops found in the Alsace region and trends observed are in accordance with the period of application of these pesticides. Variations observed permit also to demonstrate that the long time sampling duration used in this study is efficient to visualize temporal variations of airborne pesticides concentrations. Then, long time high-volume sampling could be a simple method permitting atmospheric survey of atmospheric contamination without any long analysis time and consequently low cost.

  7. Volume Entropy

    CERN Document Server

    Astuti, Valerio; Rovelli, Carlo

    2016-01-01

    Building on a technical result by Brunnemann and Rideout on the spectrum of the Volume operator in Loop Quantum Gravity, we show that the dimension of the space of the quadrivalent states --with finite-volume individual nodes-- describing a region with total volume smaller than $V$, has \\emph{finite} dimension, bounded by $V \\log V$. This allows us to introduce the notion of "volume entropy": the von Neumann entropy associated to the measurement of volume.

  8. [Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio]. Volume 3, Sampling and analysis plan (SAP): Phase 1, Task 4, Field Investigation: Draft

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    In April 1990, Wright-Patterson Air Force Base (WPAFB), initiated an investigation to evaluate a potential Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action to prevent, to the extent practicable, the offsite migration of contaminated ground water from WPAFB. WPAFB retained the services of the Environmental Management Operations (EMO) and its principle subcontractor, International Technology Corporation (IT) to complete Phase 1 of the environmental investigation of ground-water contamination at WPAFB. Phase 1 of the investigation involves the short-term evaluation and potential design for a program to remove ground-water contamination that appears to be migrating across the western boundary of Area C, and across the northern boundary of Area B along Springfield Pike. Primarily, Task 4 of Phase 1 focuses on collection of information at the Area C and Springfield Pike boundaries of WPAFB. This Sampling and Analysis Plan (SAP) has been prepared to assist in completion of the Task 4 field investigation and is comprised of the Quality Assurance Project Plan (QAPP) and the Field Sampling Plan (FSP).

  9. EVN observations of 6.7 GHz methanol maser polarization in massive star-forming regions III. The flux-limited sample

    CERN Document Server

    Surcis, G; van Langevelde, H J; Kramer, B Hutawarakorn; Bartkiewicz, A; Blasi, M G

    2015-01-01

    Theoretical simulations and observations at different angular resolutions have shown that magnetic fields have a central role in massive star formation. Like in low-mass star formation, the magnetic field in massive young stellar objects can either be oriented along the outflow axis or randomly. Measuring the magnetic field at milliarcsecond resolution (10-100 au) around a substantial number of massive young stellar objects permits determining with a high statistical significance whether the direction of the magnetic field is correlated with the orientation of the outflow axis or not. In late 2012, we started a large VLBI campaign with the European VLBI Network to measure the linearly and circularly polarized emission of 6.7 GHz methanol masers around a sample of massive star-forming regions. This paper focuses on the first seven observed sources, G24.78+0.08, G25.65+1.05, G29.86-0.04, G35.03+0.35, G37.43+1.51, G174.20-0.08, and G213.70-12.6. For all these sources, molecular outflows have been detected in the...

  10. Non-invasive genetic sampling of Southern Mule Deer (Odocoileus hemionus fuliginatus) reveals limited movement across California State Route 67 in San Diego County

    Science.gov (United States)

    Mitelberg, Anna; Vandergast, Amy

    2016-01-01

    —The Southern Mule Deer is a mobile but non-migratory large mammal found throughout southern California and is a covered species in the San Diego Multi-Species Conservation Plan. We assessed deer movement and population connectivity across California State Route 67 and two smaller roads in eastern San Diego County using non-invasive genetic sampling. We collected deer scat pellets between April and November 2015, and genotyped pellets at 15 microsatellites and a sex determination marker. We successfully genotyped 71 unique individuals from throughout the study area and detected nine recapture events. Recaptures were generally found close to original capture locations (within 1.5 km). We did not detect recaptures across roads; however, pedigree analysis detected 21 first order relative pairs, of which approximately 20% were found across State Route 67. Exact tests comparing allele frequencies between groups of individuals in pre-defined geographic clusters detected significant genetic differentiation across State Route 67. In contrast, the assignment-based algorithm of STRUCTURE supported a single genetic cluster across the study area. Our data suggest that State Route 67 may reduce, but does not preclude, movement and gene flow of Southern Mule Deer.

  11. Practical limitations of superresolution imaging due to conventional sample preparation revealed by a direct comparison of CLSM, SIM and dSTORM.

    Science.gov (United States)

    Bachmann, Michael; Fiederling, Felix; Bastmeyer, Martin

    2016-06-01

    We evaluate the suitability of conventional sample preparation and labelling methods for two superresolution techniques, structured illumination microscopy and direct stochastic optical reconstruction microscopy, by a comparison to established confocal laser scanning microscopy. We show that SIM is compatible with standard fixation procedures and immunofluorescence labelling protocols and improves resolution by a factor of two compared to confocal laser scanning microscopy. With direct stochastic optical reconstruction microscopy, fluorophores can theoretically be localized with much higher precision. However, in practice, with indirect immunofluorescence labelling density can be insufficient due to the bulky probes to reveal biological structures with high resolution. Fine structures like single actin fibres are in fact resolved with direct stochastic optical reconstruction microscopy when using small affinity probes, but require proper adjustment of the fixation protocol. Finally, by a direct comparison of immunofluorescent and genetic labelling with fluorescent proteins, we show that target morphology in direct stochastic optical reconstruction microscopy data sets can differ significantly depending on the labelling method and the molecular environment of the target.

  12. 保险中小样本信息处理的非均匀信息扩散法%General limited information diffusion method of small-sample information analysis in insurance

    Institute of Scientific and Technical Information of China (English)

    忻莉莉; 耿辉; 王永民; 张晶晶

    2007-01-01

    When analyzing and evaluating risks in insurance,people are often confronted with the situation of incomplete information and insufficient data,which is known as a small-sample problem.In this paper,a one-dimensional small-sample problem in insurance was investigated using the kernel density estimation method(KerM)and general limited information diffusion method(GIDM).In particular,MacCormack technique was applied to get the solutions of GIDM equations and then the optimal diffusion solution was acquired based on the two optimization principles.Finally,the analysis introduced in this paper was verified by treating some examples and satisfying results were obtained.

  13. Assessment of sex from endocranial cavity using volume-rendered CT scans in a sample from Medellín, Colombia.

    Science.gov (United States)

    Isaza, Juliana; Díaz, Carlos Alberto; Bedoya, John Fernando; Monsalve, Timisay; Botella, Miguel C

    2014-01-01

    Sex estimation is a primary component of the identification of skeletonized individuals in forensic anthropology. The goal of this research was to develop a new method for estimating sex based on measurements of the endocranial cavity by means of volumetric 3D reconstruction of computed tomography (CT) without contrast. The sample consisted of 249 healthy individuals of both sexes whose tomographies were taken by the imaging unit at the San Vicente de Paul University Hospital in Medellin, Colombia. Sixteen measurements (twelve were designed for this study) of each individual's endocranial base were taken and then used to create formulae via logistic regression, thereby yielding a 89.7% overall sex classification accuracy for the general equation. The measurements showing the greatest degree of sexual dimorphism were the maximum width of the basal occipital portion, the maximum width of the foramen magnum, and the maximum distance between foramina ovalia. This study represents the first physical anthropology study of this population.

  14. Scattering intensity limit value at very small angles

    CERN Document Server

    Ciccariello, Salvino

    2016-01-01

    The existence of the limit of a sample scattering intensity, as the scattering vector approaches zero, requires and is ensured by the property that the mean value of the scattering density fluctuation over volume $V$ asymptotically behaves, at large $V$s, as $\

  15. Direct and indirect methods for the quantification of leg volume: Comparison between water displacement volumetry, the disk model method and the frustum sign model method, using the correlation coefficient and the limits of agreement

    NARCIS (Netherlands)

    D.M.K.S. Kaulesar Sukul (D. M K S); P.Th. den Hoed (Pieter); T. Johannes (Tanja); R. van Dolder (R.); E. Benda (Eric)

    1993-01-01

    textabstractVolume changes can be measured either directly by water-displacement volumetry or by various indirect methods in which calculation of the volume is based on circumference measurements. The aim of the present study was to determine the most appropriate indirect method for lower leg volume

  16. Direct and indirect methods for the quantification of leg volume: Comparison between water displacement volumetry, the disk model method and the frustum sign model method, using the correlation coefficient and the limits of agreement

    NARCIS (Netherlands)

    D.M.K.S. Kaulesar Sukul (D. M K S); P.Th. den Hoed (Pieter); T. Johannes (Tanja); R. van Dolder (R.); E. Benda (Eric)

    1993-01-01

    textabstractVolume changes can be measured either directly by water-displacement volumetry or by various indirect methods in which calculation of the volume is based on circumference measurements. The aim of the present study was to determine the most appropriate indirect method for lower leg volume

  17. 大体积水中痕量POPs的联动采集装置及其性能评价%A Linkage Sampling Equipment for Collecting Trace POPs in High - Volume Water and Its Performance Evaluation

    Institute of Scientific and Technical Information of China (English)

    苏凡; 张海军; 袁和平; 刘崇杰; 齐沛沛; 陈吉平

    2011-01-01

    天然水体中的痕量持久性有机污染物(POPs)的定量分析通常需要采集大体积水样.针对大体积水样在过滤和吸附富集过程中滤膜易堵塞且耗时费力的缺点,研制了一种固液分离过滤-吸附富集联动装置.该装置主要由粗过滤器、离心分离屏、倒置微孔过滤器、固相吸附柱、流速控制阀和真空泵组成.与传统的滤膜过滤方式相比,其过滤效率提高了约1.5倍.利用此采样装置对大连西山水库水样和大辽河干流水样进行了富集,并采用高分辨气相色谱-高分辨质谱定量分析了其中的二(口恶)(口英)(PCDD/Fs)和多氯联苯(PCBs)的含量.结果表明,填加的13C12 - PCDD/Fs回收率能够满足HJ 77.1 -2008分析标准要求,填加的13C12 - PCBs回收率为40% ~ 100%,17种2,3,7,8位氯取代PCDD/Fs的相对标准偏差变化范围为16.3% ~ 24.7%.该采样装置使用简单,适合于大体积水样中痕量POPs的富集.%A high-volume water sampling is a necessary means to quantify trace persistent organic pollutants ( POPs) in natural water. However, the filter is so easily blocked that the filtration work can take a long time during the filtration of high-volume water. As for the disadvantage, a filtration-adsorption linkage water sampling equipment was developed. It was mainly composed of preliminary filter, centrifugal separation shield, upside-down membrane filter, solid-phase adsorption column, flow rate control valve, and vacuum pump. Compared with conventional membrane filtration method, the filtration efficiency was enhanced by about 1.5 times when using the linkage sampling equipment. Moreover, polychiorinated dibenzo-p-dioxins and furans ( PCOD/Fs) and polychiorinated biphenyls ( PCBs) in water samples from Xishan Reservoir of Dalian and from the mainstream of Dalian River, collected by the linkage sampling equipment, were analyzed using high-resolution gas chromatography combined with high-resolution mass

  18. Development of a solid-phase extraction system modified for preconcentration of emerging contaminants in large sample volumes from rivers of the lagoon system in the city of Rio de Janeiro, Brazil.

    Science.gov (United States)

    Lopes, Vitor Sergio Almeida; Riente, Roselene Ribeiro; da Silva, Alexsandro Araújo; Torquilho, Delma Falcão; Carreira, Renato da Silva; Marques, Mônica Regina da Costa

    2016-09-15

    A single method modified for monitoring of emerging contaminants in river water was developed for large sample volumes. Water samples from rivers of the lagoon system in the city of Rio de Janeiro (Brazil) were analyzed by the SPE-HPLC-MS-TOF analytical method. Acetaminophen was detected in four rivers in the concentration range of 0.09μgL(-1) to 0.14μgL(-1). Salicylic acid was also found in the four rivers in the concentration range of 1.65μgL(-1) to 4.81μgL(-1). Bisphenol-A was detected in all rivers in the concentration range of 1.37μgL(-1) to 39.86μgL(-1). Diclofenac was found in only one river, with concentration of 0.22μgL(-1). The levels of emerging organic pollutants in the water samples of the Jacarepaguá hydrographical basin are significant. The compounds are not routinely monitored and present potential risks to environmental health.

  19. 高维样本协方差矩阵极限谱密度的显式表达式%Explicit Expression of Limiting Spectral Density of High Dimensional Sample Covariance Matrices

    Institute of Scientific and Technical Information of China (English)

    高瑞梅; 吕堂红; 胡江

    2016-01-01

    Using the method of Stieltjes transform,we gave the explicit expressions of the limiting spectral density functions of the general high dimensional sample covariance matrices,which included:the sample covariance matrix whose elements were independent with zero mean and constant variance;the sum of a sample covariance matrix and a unit matrix;the sample covariance matrix which satisfied that the variance of the elements were different but only had two values;the sum of two different sample covariance matrices.%用 Stieltjes 变换给出一般高维样本协方差矩阵的极限密度函数的显示表达式,包括:样本元素独立且均值为0,方差为常数的样本协方差矩阵;一个样本协方差矩阵与单位阵的和;样本元素方差不等但只取两值的样本协方差矩阵;两个不同的样本协方差矩阵之和。

  20. Instructions for Sampling Particulates.

    Science.gov (United States)

    Ekman, Frank

    This technical report presents detailed instructions for sampling particulates. The table of contents includes sections on Introduction, Volume Determinations, Apparatus - Assembly and Operation, Sampling Techniques, and Acknowledgment. Six charts, 24 graphs, and one diagram are appended to facilitate sampling, as well as sections on Isokinetic…

  1. Recommendations for representative ballast water sampling

    Science.gov (United States)

    Gollasch, Stephan; David, Matej

    2017-05-01

    Until now, the purpose of ballast water sampling studies was predominantly limited to general scientific interest to determine the variety of species arriving in ballast water in a recipient port. Knowing the variety of species arriving in ballast water also contributes to the assessment of relative species introduction vector importance. Further, some sampling campaigns addressed awareness raising or the determination of organism numbers per water volume to evaluate the species introduction risk by analysing the propagule pressure of species. A new aspect of ballast water sampling, which this contribution addresses, is compliance monitoring and enforcement of ballast water management standards as set by, e.g., the IMO Ballast Water Management Convention. To achieve this, sampling methods which result in representative ballast water samples are essential. We recommend such methods based on practical tests conducted on two commercial vessels also considering results from our previous studies. The results show that different sampling approaches influence the results regarding viable organism concentrations in ballast water samples. It was observed that the sampling duration (i.e., length of the sampling process), timing (i.e., in which point in time of the discharge the sample is taken), the number of samples and the sampled water quantity are the main factors influencing the concentrations of viable organisms in a ballast water sample. Based on our findings we provide recommendations for representative ballast water sampling.

  2. Reachable volume RRT

    KAUST Repository

    McMahon, Troy

    2015-05-01

    © 2015 IEEE. Reachable volumes are a new technique that allows one to efficiently restrict sampling to feasible/reachable regions of the planning space even for high degree of freedom and highly constrained problems. However, they have so far only been applied to graph-based sampling-based planners. In this paper we develop the methodology to apply reachable volumes to tree-based planners such as Rapidly-Exploring Random Trees (RRTs). In particular, we propose a reachable volume RRT called RVRRT that can solve high degree of freedom problems and problems with constraints. To do so, we develop a reachable volume stepping function, a reachable volume expand function, and a distance metric based on these operations. We also present a reachable volume local planner to ensure that local paths satisfy constraints for methods such as PRMs. We show experimentally that RVRRTs can solve constrained problems with as many as 64 degrees of freedom and unconstrained problems with as many as 134 degrees of freedom. RVRRTs can solve problems more efficiently than existing methods, requiring fewer nodes and collision detection calls. We also show that it is capable of solving difficult problems that existing methods cannot.

  3. Design for volume reduction

    NARCIS (Netherlands)

    Wever, R.; Boks, C.; Stevels, A.

    2007-01-01

    Traditionally packaging design-for-sustainability (DfS) strongly focuses on resource conservation and material recycling. The type and amount of materials used has been the driver in design. For consumer electronics (CE) products this weight-based approach is too limited; a volume-based approach is

  4. Fault current limiter using bulk oxides superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Belmont, O.; Ferracci, P.; Porcar, L.; Barbut, J.M. [Schneider Electric, Grenoble (France). Usine A3; Tixador, P.; Noudem, J.G.; Bourgault, D.; Tournier, R

    1998-08-01

    We study the limitation possibilities of bulk Bi high T{sub c} materials. For this we test these materials with AC or DC currents above their critical currents. We study particularly the evolution of the voltage with time or with current. The material, the value of the current and the time duration play important parts. For sintered Bi samples the voltage depends only on the current even for values much larger than the critical current. With textured samples the V(I) curves shows an hysteretic behaviour due to a warming up. The textured materials are more interesting than sintered ones in terms of required volume for the current limitation. In both cases the superconductors are in a dissipative state but not in the normal state. This state is nevertheless reached if the dissipated energy inside the sample is sufficient. We have tried to apply a magnetic field on the samples in order to trigger a more effective limitation. The voltage increases but with a limited effect for currents much higher (3-4 times) than the critical zero field current. We think that the dissipative state is due mainly to the grain boundaries which become resistive above the critical current. (orig.) 11 refs.

  5. Age Limits.

    Science.gov (United States)

    Antfolk, Jan

    2017-03-01

    Whereas women of all ages prefer slightly older sexual partners, men-regardless of their age-have a preference for women in their 20s. Earlier research has suggested that this difference between the sexes' age preferences is resolved according to women's preferences. This research has not, however, sufficiently considered that the age range of considered partners might change over the life span. Here we investigated the age limits (youngest and oldest) of considered and actual sex partners in a population-based sample of 2,655 adults (aged 18-50 years). Over the investigated age span, women reported a narrower age range than men and women tended to prefer slightly older men. We also show that men's age range widens as they get older: While they continue to consider sex with young women, men also consider sex with women their own age or older. Contrary to earlier suggestions, men's sexual activity thus reflects also their own age range, although their potential interest in younger women is not likely converted into sexual activity. Compared to homosexual men, bisexual and heterosexual men were more unlikely to convert young preferences into actual behavior, supporting female-choice theory.

  6. Analytical Results for 35 Mine-Waste Tailings Cores and Six Bed-Sediment Samples, and An Estimate of the Volume of Contaminated Material at Buckeye Meadow on Upper Basin Creek, Northern Jefferson County, Montana

    Science.gov (United States)

    Fey, David L.; Church, Stan E.; Finney, Christopher J.

    1999-01-01

    Metal-mining related wastes in the Boulder River basin study area in northern Jefferson County, Montana have been implicated in their detrimental effects on water quality with regard to acid-generation and toxic-metal solubilization. Flotation-mill tailings in the meadow below the Buckeye mine, hereafter referred to as the Buckeye mill-tailings site, have been identified as significant contributors to water quality degradation of Basin Creek, Montana. Basin Creek is one of three tributaries to the Boulder River in the study area; bed sediments and waters draining from the Buckeye mine have also been implicated. Geochemical analysis of 35 tailings cores and six bed-sediment samples was undertaken to determine the concentrations of Ag, As, Cd, Cu, Pb,and Zn present in these materials. These elements are environmentally significant, in that they can be toxic to fish and/or the invertebrate organisms that constitute their food. A suite of one-inch cores of dispersed flotation-mill tailings and underlying premining material was taken from a large, flat area north of Basin Creek near the site of the Buckeye mine. Thirty-five core samples were taken and divided into 204 subsamples. The samples were analyzed by ICP-AES (inductively coupled plasma-atomic emission spectroscopy) using a mixed-acid digestion. Results of the core analyses show that the elements listed above are present at moderate to very high concentrations (arsenic to 63,000 ppm, silver to 290 ppm, cadmium to 370 ppm, copper to 4,800 ppm, lead to 93,000 ppm, and zinc to 23,000 ppm). Volume calculations indicate that an estimated 8,400 metric tons of contaminated material are present at the site. Six bed-sediment samples were also subjected to the mixed-acid total digestion, and a warm (50°C) 2M HCl-1% H2O2 leach and analyzed by ICP-AES. Results indicate that bed sediments of Basin Creek are only slightly impacted by past mining above the Buckeye-Enterprise complex, moderately impacted at the upper (eastern

  7. 快餐业限时物流配送服务对在线点餐销售的影响%Influence of Time-limited Logistics Distribution Services on Online Ordering Volume of Fast Food Businesses

    Institute of Scientific and Technical Information of China (English)

    董媛

    2014-01-01

    In this paper, on the basis of the consumption selection theory, we built an analytic model of the promotional effect of the time-limited logistics distribution services on the online ordering volume of the fast food industry, then with the database of the Fantong Net, an online meal ordering platform active in the Xi’an region, as the source, used the structural equation model to study the influence of these services on the ordering behaviors of the consumers through the platform, and at the end, in view of the conclusions, proposed the corresponding countermeasures.%针对应用电子商务模式在线点餐出现的送货耗时过长及点餐流程繁琐等经常被消费者投诉的问题,基于消费选择理论构建一个快餐业限时物流配送服务对在线点餐销售促进作用分析模型,以西安地区饭统网订餐平台数据库作为数据来源,运用结构方程模型研究限时物流配送服务对消费者通过电子商务平台订购餐饮行为的影响。研究结果显示,消费者对快餐口感的满意度受快餐配送时间影响显著,快餐配送时间是决定消费者重复购买和满意度的最主要因素,其次是快餐质量。指出与日常消费品、服饰等产品不同,采用电子平台销售模式的快餐业应当更加关注如何保证物流服务质量。

  8. Identification of a Complete 160 micron Flux-Limited Sample of Infrared Galaxies in the ISO Lockman Hole 1-Deg^2 Deep Fields: Source Properties and Evidence for Strong Evolution in the FIR Luminosity Function for ULIRGs

    CERN Document Server

    Jacobs, Bradley A; Rupke, David S N; Aussel, Herve; Frayer, David T; Ilbert, Olivier; Kartaltepe, Jeyhan S; Kawara, Kimiaki; Kim, Dong-Chan; Floc'h, Emiric Le; Murayama, Takashi; Smolcic, Vernesa; Surace, Jason A; Taniguchi, Yoshi; Veilleux, Sylvain; Yun, Min S

    2011-01-01

    We have identified a complete, flux-limited, (S_160>120 mJy), sample of 160 micron-selected sources from Spitzer observations of the 1-deg^2 ISO Deep Field region in the Lockman Hole. Ground-based UV, optical and near-infrared (NIR) photometry and optical spectroscopy have been used to determine colors, redshifts and masses for the complete sample of 40 galaxies. Spitzer-IRAC+MIPS photometry, supplemented by ISOPHOT data at 90 micron and 170 micron, has been used to calculate accurate total infrared luminosities, LIR(8-1000 micron), and to determine the IR luminosity function (LF) of luminous infrared galaxies (LIRGs). The maximum observed redshift is z~0.80 and the maximum total infrared luminosity is log(L_IR/L_Sun)=12.74. Over the luminosity range log(L_IR/L_Sun)=10-12, the LF for LIRGs in the Lockman Hole Deep Field is similar to that found previously for local sources at similar infrared luminosities. The mean host galaxy mass, log(M/M_Sun)=10.7, and dominance of HII-region spectral types, is also simila...

  9. Spectrophotometric determination of Sudan Blue II in environmental samples after dispersive liquid-liquid microextraction

    Directory of Open Access Journals (Sweden)

    Yunus Emre Unsal

    2014-01-01

    Full Text Available A dispersive liquid-liquid microextraction procedure coupled to spectrophotometry is described for the determination of the trace levels of Sudan Blue II. Analytical parameters, such as pH, volume of extraction solvent (carbon tetrachloride, volume of dispersant (ethanol, volume of sample, and extraction time, were optimized. Matrix effects were also investigated. Preconcentration factor was found to be 200. Detection limit and relative standard deviation (RSD were 0.55 µg L-1 and 3.9%, respectively. The procedure was successfully used for the determination of trace levels of Sudan Blue II in food, ink, antifreeze, and industrial waste-water samples.

  10. Mold Testing or Sampling

    Science.gov (United States)

    In most cases, if visible mold growth is present, sampling is unnecessary. Since no EPA or other federal limits have been set for mold or mold spores, sampling cannot be used to check a building's compliance with federal mold standards.

  11. Current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Loescher, D.H. [Sandia National Labs., Albuquerque, NM (United States). Systems Surety Assessment Dept.; Noren, K. [Univ. of Idaho, Moscow, ID (United States). Dept. of Electrical Engineering

    1996-09-01

    The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

  12. An Improved Multivariate T2 Control Chart for Individual Observations in Low Volume Manufacturing

    Institute of Scientific and Technical Information of China (English)

    Miao Rui(苗瑞); Wang Dongpeng; Yao Yingxue

    2004-01-01

    For multivariate statistical process quality control with individual observations, the usually recommended procedure is Hotelling's T2 control chart. Using the T2 statistic based on β distribution is an exact method for constructing multivariate control limits in low volume manufacturing, but it is not convenient in that the variation of sample size leads to a change in control limit. This paper presents an improved multivariate T2 control chart whose control limit does not change with sample size, which is especially useful when the sample size is small.

  13. Developmentally Stable Whole-Brain Volume Reductions and Developmentally Sensitive Caudate and Putamen Volume Alterations in Those With Attention-Deficit/Hyperactivity Disorder and Their Unaffected Siblings

    NARCIS (Netherlands)

    Greven, Corina U.; Bralten, Janita; Mennes, Maarten; O'Dwyer, Laurence; van Hulzen, Kimm J. E.; Rommelse, Nanda; Schweren, Lizanne J. S.; Hoekstra, Pieter J.; Hartman, Catharina A.; Heslenfeld, Dirk; Oosterlaan, Jaap; Faraone, Stephen V.; Franke, Barbara; Zwiers, Marcel P.; Arias-Vasquez, Alejandro; Buitelaar, Jan K.

    2015-01-01

    IMPORTANCE Attention-deficit/hyperactivity disorder (ADHD) is a heritable neurodevelopmental disorder. It has been linked to reductions in total brain volume and subcortical abnormalities. However, owing to heterogeneity within and between studies and limited sample sizes, findings on the neuroanato

  14. The quantum geometric limit

    CERN Document Server

    Lloyd, Seth

    2012-01-01

    This letter analyzes the limits that quantum mechanics imposes on the accuracy to which spacetime geometry can be measured. By applying the fundamental physical bounds to measurement accuracy to ensembles of clocks and signals moving in curved spacetime -- e.g., the global positioning system -- I derive a covariant version of the quantum geometric limit: the total number of ticks of clocks and clicks of detectors that can be contained in a four volume of spacetime of radius r and temporal extent t is less than or equal to rt/\\pi x_P t_P, where x_P, t_P are the Planck length and time. The quantum geometric limit bounds the number of events or `ops' that can take place in a four-volume of spacetime: each event is associated with a Planck-scale area. Conversely, I show that if each quantum event is associated with such an area, then Einstein's equations must hold. The quantum geometric limit is consistent with and complementary to the holographic bound which limits the number of bits that can exist within a spat...

  15. Limited Neutrality

    DEFF Research Database (Denmark)

    Nielsen, Morten Ebbe Juul

    2006-01-01

    Article Concerning the prospect of a kind of limited neutrality in place of the standard liberal egalitarian "neutrality of justification."......Article Concerning the prospect of a kind of limited neutrality in place of the standard liberal egalitarian "neutrality of justification."...

  16. Limiting Skepticism

    DEFF Research Database (Denmark)

    Hendricks, Vincent Fella; Symons, John

    2011-01-01

    Skeptics argue that the acquisition of knowledge is impossible given the standing possibility of error. We present the limiting convergence strategy for responding to skepticism and discuss the relationship between conceivable error and an agent’s knowledge in the limit. We argue that the skeptic...

  17. Limited Neutrality

    DEFF Research Database (Denmark)

    Nielsen, Morten Ebbe Juul

    2006-01-01

    Article Concerning the prospect of a kind of limited neutrality in place of the standard liberal egalitarian "neutrality of justification."......Article Concerning the prospect of a kind of limited neutrality in place of the standard liberal egalitarian "neutrality of justification."...

  18. False-negative rate, limit of detection and recovery efficiency performance of a validated macrofoam-swab sampling method for low surface concentrations of Bacillus anthracis Sterne and Bacillus atrophaeus spores

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, G. F. [Applied Statistics and Computational Sciences, Pacific Northwest National Laboratory, Richland WA USA; Deatherage Kaiser, B. L. [Chemical and Biological Signature Science Group, Pacific Northwest National Laboratory, Richland WA USA; Amidan, B. G. [Applied Statistics and Computational Sciences, Pacific Northwest National Laboratory, Richland WA USA; Sydor, M. A. [Chemical and Biological Signature Science Group, Pacific Northwest National Laboratory, Richland WA USA; Barrett, C. A. [Analytical Chemistry of Nuclear Materials, Pacific Northwest National Laboratory, Richland WA USA; Hutchison, J. R. [Chemical and Biological Signature Science Group, Pacific Northwest National Laboratory, Richland WA USA

    2016-05-06

    The performance of a macrofoam-swab sampling method was evaluated using Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus Nakamura (BG) spores applied at nine low target amounts (2-500 spores) to positive-control plates and test coupons (2 in × 2 in) of four surface materials (glass, stainless steel, vinyl tile, and plastic). Test results from cultured samples were used to evaluate the effects of surrogate, surface concentration, and surface material on recovery efficiency (RE), false negative rate (FNR), and limit of detection. For RE, surrogate and surface material had statistically significant effects, but concentration did not. Mean REs were the lowest for vinyl tile (50.8% with BAS and 40.2% with BG) and the highest for glass (92.8% with BAS and 71.4% with BG). FNR values ranged from 0 to 0.833 for BAS and 0 to 0.806 for BG; values increased as concentration decreased in the range tested (0.078 to 19.375 CFU/cm2). Surface material also had a statistically significant effect. A FNR-concentration curve was fit for each combination of surrogate and surface material. For both surrogates, the FNR curves tended to be the lowest for glass and highest for vinyl title. The FNR curves for BG tended to be higher than for BAS at lower concentrations, especially for glass. Results using a modified Rapid Viability-Polymerase Chain Reaction (mRV-PCR) analysis method were also obtained. The mRV-PCR results and comparisons to the culture results will be discussed in a subsequent article.

  19. Renormalized Volume

    Science.gov (United States)

    Gover, A. Rod; Waldron, Andrew

    2017-09-01

    We develop a universal distributional calculus for regulated volumes of metrics that are suitably singular along hypersurfaces. When the hypersurface is a conformal infinity we give simple integrated distribution expressions for the divergences and anomaly of the regulated volume functional valid for any choice of regulator. For closed hypersurfaces or conformally compact geometries, methods from a previously developed boundary calculus for conformally compact manifolds can be applied to give explicit holographic formulæ for the divergences and anomaly expressed as hypersurface integrals over local quantities (the method also extends to non-closed hypersurfaces). The resulting anomaly does not depend on any particular choice of regulator, while the regulator dependence of the divergences is precisely captured by these formulæ. Conformal hypersurface invariants can be studied by demanding that the singular metric obey, smoothly and formally to a suitable order, a Yamabe type problem with boundary data along the conformal infinity. We prove that the volume anomaly for these singular Yamabe solutions is a conformally invariant integral of a local Q-curvature that generalizes the Branson Q-curvature by including data of the embedding. In each dimension this canonically defines a higher dimensional generalization of the Willmore energy/rigid string action. Recently, Graham proved that the first variation of the volume anomaly recovers the density obstructing smooth solutions to this singular Yamabe problem; we give a new proof of this result employing our boundary calculus. Physical applications of our results include studies of quantum corrections to entanglement entropies.

  20. On thermodynamic limits of entropy densities

    NARCIS (Netherlands)

    Moriya, H; Van Enter, A

    1998-01-01

    We give some sufficient conditions which guarantee that the entropy density in the thermodynamic limit is equal to the thermodynamic limit of the entropy densities of finite-volume (local) Gibbs states.

  1. Site Environmental Report for 2009, Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Suying

    2010-08-19

    Volume II of the Site Environmental Report for 2009 is provided by Ernest Orlando Lawrence Berkeley National Laboratory as a supplemental appendix to Volume I, which contains the body of the report. Volume II contains the environmental monitoring and sampling data used to generate summary results of routine and nonroutine sampling at the Laboratory, except for groundwater sampling data, which may be found in the reports referred to in Chapter 4 of Volume I. The results from sample collections are more comprehensive in Volume II than in Volume I: for completeness, all results from sample collections that began or ended in calendar year (CY) 2009 are included in this volume. However, the samples representing CY 2008 data have not been used in the summary results that are reported in Volume I. (For example, although ambient air samples collected on January 6, 2009, are presented in Volume II, they represent December 2008 data and are not included in Table 4-2 in Volume I.) When appropriate, sampling results are reported in both conventional and International System (SI) units. For some results, the rounding procedure used in data reporting may result in apparent differences between the numbers reported in SI and conventional units. (For example, stack air tritium results reported as < 1.5 Bq/m3 are shown variously as < 39 and < 41 pCi/m3. Both of these results are rounded correctly to two significant digits.)

  2. Porosity, single-phase permeability, and capillary pressure data from preliminary laboratory experiments on selected samples from Marker Bed 139 at the Waste Isolation Pilot Plant. Volume 3 of 3: Appendices C, D, E, and F

    Energy Technology Data Exchange (ETDEWEB)

    Howarth, S.M.; Christian-Frear, T.

    1997-08-01

    This volume contains the mineralogy, porosity, and permeability results from the Marker Bed 139 anhydrite specimens evaluated by TerraTek, Inc. for the Waste Isolation Pilot Plant. This volume also documents the brine recipe used by RE/SPEC, Inc., the parameter package submitted to Performance Assessment based on all the data, and a memo on the mixed Brooks and Corey two-phase characteristic curves.

  3. Inverse Limits

    CERN Document Server

    Ingram, WT

    2012-01-01

    Inverse limits provide a powerful tool for constructing complicated spaces from simple ones. They also turn the study of a dynamical system consisting of a space and a self-map into a study of a (likely more complicated) space and a self-homeomorphism. In four chapters along with an appendix containing background material the authors develop the theory of inverse limits. The book begins with an introduction through inverse limits on [0,1] before moving to a general treatment of the subject. Special topics in continuum theory complete the book. Although it is not a book on dynamics, the influen

  4. Comparing Volumes of Prisms and Pyramids

    Science.gov (United States)

    Vinogradova, Natalya

    2012-01-01

    Students' experience in using formulas for volumes is often limited to substituting numbers into given formulas. An activity presented in this article may help students make connections between the formulas for volumes of prisms and volumes of pyramids. In addition, some interesting facts from number theory arise, demonstrating strong connections…

  5. A serial sample loading system: interfacing multiwell plates with microfluidic devices.

    Science.gov (United States)

    Rane, Tushar D; Zec, Helena C; Wang, Tza-Huei

    2012-10-01

    There is an increasing demand for novel high-throughput screening (HTS) technologies in the pharmaceutical and biotechnological industries. The robotic sample-handling techniques currently used in these industries, although fast, are still limited to operating in multiwell plates with the sample volumes per reaction in the microliter regime. Digital microfluidics offers an alternative for reduction in sample volume consumption for HTS but lacks a reliable technique for transporting a large number of samples to the microfluidic device. In this report, we develop a technique for serial delivery of sample arrays to a microfluidic device from multiwell plates, through a single sample inlet. Under this approach, a serial array of sample plugs, separated by an immiscible carrier fluid, is loaded into a capillary and delivered to a microfluidic device. Similar approaches have been attempted in the past, however, either with a slower sample loading device such as a syringe pump or vacuum-based sample loading with limited driving pressure. We demonstrated the application of our positive-pressure-based serial sample loading (SSL) system to load a series of sample plugs into a capillary. The adaptability of the SSL system to generate sample plugs with a variety of volumes in a predictable manner was also demonstrated.

  6. Sampling and II-Sampling Expansions

    Indian Academy of Sciences (India)

    J Sousa Pinto; R F Hoskins

    2000-11-01

    Using the hyperfinite representation of functions and generalized functions this paper develops a rigorous version of the so-called `delta method' approach to sampling theory. This yields a slightly more general version of the classical WKS sampling theorem for band-limited functions.

  7. Quantification of Protozoa and Viruses from Small Water Volumes

    Directory of Open Access Journals (Sweden)

    J. Alfredo Bonilla

    2015-06-01

    Full Text Available Large sample volumes are traditionally required for the analysis of waterborne pathogens. The need for large volumes greatly limits the number of samples that can be processed. The aims of this study were to compare extraction and detection procedures for quantifying protozoan parasites and viruses from small volumes of marine water. The intent was to evaluate a logistically simpler method of sample collection and processing that would facilitate direct pathogen measures as part of routine monitoring programs. Samples were collected simultaneously using a bilayer device with protozoa capture by size (top filter and viruses capture by charge (bottom filter. Protozoan detection technologies utilized for recovery of Cryptosporidium spp. and Giardia spp. were qPCR and the more traditional immunomagnetic separation—IFA-microscopy, while virus (poliovirus detection was based upon qPCR versus plaque assay. Filters were eluted using reagents consistent with the downstream detection technologies. Results showed higher mean recoveries using traditional detection methods over qPCR for Cryptosporidium (91% vs. 45% and poliovirus (67% vs. 55% whereas for Giardia the qPCR-based methods were characterized by higher mean recoveries (41% vs. 28%. Overall mean recoveries are considered high for all detection technologies. Results suggest that simultaneous filtration may be suitable for isolating different classes of pathogens from small marine water volumes. More research is needed to evaluate the suitability of this method for detecting pathogens at low ambient concentration levels.

  8. Uranium in US surface, ground, and domestic waters. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Drury, J.S.; Reynolds, S.; Owen, P.T.; Ross, R.H.; Ensminger, J.T.

    1981-04-01

    The report Uranium in US Surface, Ground, and Domestic Waters comprises four volumes. Volumes 2, 3, and 4 contain data characterizing the location, sampling date, type, use, and uranium conentrations of 89,994 individual samples presented in tabular form. The tabular data in volumes 2, 3, and 4 are summarized in volume 1 in narrative form and with maps and histograms.

  9. Two phase sampling

    CERN Document Server

    Ahmad, Zahoor; Hanif, Muhammad

    2013-01-01

    The development of estimators of population parameters based on two-phase sampling schemes has seen a dramatic increase in the past decade. Various authors have developed estimators of population using either one or two auxiliary variables. The present volume is a comprehensive collection of estimators available in single and two phase sampling. The book covers estimators which utilize information on single, two and multiple auxiliary variables of both quantitative and qualitative nature. Th...

  10. Limited sampling strategies for tacrolimus exposure (AUC0-24) prediction after Prograf(®) and Advagraf(®) administration in children and adolescents with liver or kidney transplants.

    Science.gov (United States)

    Almeida-Paulo, Gonzalo N; Lubomirov, Rubin; Alonso-Sanchez, Nazareth Laura; Espinosa-Román, Laura; Fernández Camblor, Carlota; Díaz, Carmen; Muñoz Bartola, Gema; Carcas-Sansuán, Antonio J

    2014-09-01

    To develop limited sampling strategies (LSSs) to predict total tacrolimus exposure (AUC0-24 ) after the administration of Advagraf(®) and Prograf(®) (Astellas Pharma S.A, Madrid, Spain) to pediatric patients with stable liver or kidney transplants. Forty-one pharmacokinetic profiles were obtained after Prograf(®) and Advagraf(®) administration. LSSs predicting AUC0-24 were developed by linear regression using three extraction time points. Selection of the most accurate LSS was made based on the r(2) , mean error, and mean absolute error. All selected LSSs had higher correlation with AUC0-24 than the correlation found between C0 and AUC0-24 . Best LSS for Prograf(®) in liver transplants was C0_1.5_4 (r(2)  = 0.939) and for kidney transplants C0_1_3 (r(2)  = 0.925). For Advagraf(®) , the best LSS in liver transplants was C0_1_2.5 (r(2)  = 0.938) and for kidney transplants was C0_0.5_4 (r(2)  = 0.931). Excluding transplant type variable, the best LSS for Prograf(®) is C0-1-3 (r(2)  = 0.920) and the best LSS for Advagraf(®) was C0_0.5_4 (r(2)  = 0.926). Considering transplant type irrespective of the formulation used, the best LSS for liver transplants was C0_2_3 (r(2)  = 0.913) and for kidney transplants was C0_0.5_4 (r(2)  = 0.898). Best LSS, considering all data together, was C0_1_4 (r(2)  = 0.898). We developed several LSSs to predict AUC0-24 for tacrolimus in children and adolescents with kidney or liver transplants after Prograf(®) and/or Advagraf(®) treatment.

  11. Renormalized Volume

    CERN Document Server

    Gover, A Rod

    2016-01-01

    For any conformally compact manifold with hypersurface boundary we define a canonical renormalized volume functional and compute an explicit, holographic formula for the corresponding anomaly. For the special case of asymptotically Einstein manifolds, our method recovers the known results. The anomaly does not depend on any particular choice of regulator, but the coefficients of divergences do. We give explicit formulae for these divergences valid for any choice of regulating hypersurface; these should be relevant to recent studies of quantum corrections to entanglement entropies. The anomaly is expressed as a conformally invariant integral of a local Q-curvature that generalizes the Branson Q-curvature by including data of the embedding. In each dimension this canonically defines a higher dimensional generalization of the Willmore energy/rigid string action. We show that the variation of these energy functionals is exactly the obstruction to solving a singular Yamabe type problem with boundary data along the...

  12. Quantification of the radar reflectivity sampling error in non-stationary rain using paired disdrometers

    NARCIS (Netherlands)

    Berne, A.D.; Uijlenhoet, R.

    2005-01-01

    Knowledge of the raindrop size distribution (DSD) is essential for understanding the physics of precipitation and for interpreting remotely sensed observations of rain. Disdrometer measurements of DSDs are affected by uncertainties due to the limited sampling volumes or areas of the sensors. Determi

  13. Limits on $\

    CERN Document Server

    Perego, D L

    2002-01-01

    A limit on the tau neutrino mass is obtained using all the $Z^{0} \\to \\tau^{+} \\tau^{-}$ data collected at LEP by the DELPHI detector between 1992 and 1995. In this analysis events in which one of the taus decays into one charged particle, while the second $\\tau$ decays into f{}ive charged pions (1-5 topology) have been used. The neutrino mass is determined from a bidimensional \\fit ~on the invariant mass $m^{*}_{5 \\pi}$ and on the energy $E_{5 \\pi}$ of the f{}ive $\\pi^{\\pm}$ system. The result found is $m_{\

  14. Alternative sample preparation methods for MALDI-MS

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, G.B.; Buchanan, M.V. [Oak Ridge National Lab., TN (United States); Czartoski, T.J. [Kenyon College, Gambier, OH (United States)

    1994-12-31

    Since the introduction of matrix-assisted laser desorption and ionization (MALDI), sample preparation has been a limiting step in the applicability of this important technique for mass spectrometric analysis of biomolecules. A number of variations on the original sample preparation method for have been described. The {open_quotes}standard{close_quotes} method of MALDI sample preparation requires mixing a solution containing the analyte and a large excess of matrix, and allowing a small volume of this solution to dry on a probe tip before insertion into the mass spectrometer. The resulting sample can fairly inhomogeneous. As a result, the process of aiming the desorption laser at a favorable spot on the dried sample can be tedious and time-consuming. The authors are evaluating several approaches to MALDI sample preparation, with the goal of developing a faster and more reproducible method.

  15. Bioequivalence assessment of amoxicillin by limited sampling strategy in Chinese healthy volunteers%LSS法估算中国健康志愿者口服阿莫西林的生物等效性

    Institute of Scientific and Technical Information of China (English)

    陈丽芳; 焦建杰; 张才丽; 娄建石

    2012-01-01

    Objective To develop limited sampling strategy ( LSS) for estimating bioequivalence of amoxicillin. Methods Twenty male healthy subjects were enrolled in this bioequivalence study. All subjects were divided into two groups randomly and administered orally reference and test formulation of 500 mg amoxicillin. The blood concentrations of amoxicillin were determined by the validated HPLC method. A multiple linear regression analysis was developed for estimating Cmax and AUC0_t using the amoxicillin concentration of the reference formulation to develop LSS models. The LSS models were internally validated by the Jackknife meth od. The models were also externally validated by bioequivalence assessment of the test amoxicillin formulation based on LSS derived Cmax and AUC0-t values, The results were compared with those obtained using traditional method. Results The results indicate: several models for these parameters estimation met the predefined criteria. Validation tests indicated that most informative sampling points C1, C3 and C1 ,C2,C4 provided accurate estimations of the parameters AUC0-1, ( prediction error < 1% , absolute percentage < 10% ) ,And C1 ,C1.5 and C1.5 ,C2,C6 provided accurate estimations of the parameters Cmax ( prediction error < 2% , absolute percentage < 9%) . The combination of C1.5, C2, C6 might be chosen as sampling hours for predicting AUC0-t, and Cmax according to requirement. It is according with classical assessment. Conclusion The bioequivalence assessment results showed that LSS models provided correct assessment of bio equivalence between two amoxicillin preparations. The method is accurant and can be considered desirable for amoxicil lin bioequivalence study.%目的 用有限采样法(LSS)估算口服阿莫西林的生物等效性.方法 20名健康志愿者口服阿莫西林参比药物和受试药物500 mg后采集若干时间点血浆样品,用高效液相色谱法测定阿莫西林血药浓度,用经典方法计算药代动力学参

  16. [How to push the limits in the transverse dimension? Facial asymmetry, palatal volume and tongue posture in children with unilateral posterior cross bite: a three-dimensional evaluation of early treatment].

    Science.gov (United States)

    Ovsenik, Maja; Primožič, Jasmina

    2014-06-01

    Unilateral posterior crossbites have been reported to be one of the most prevalent malocclusions of the primary dentition in Caucasian children. Facial asymmetry due to lateral mandibular displacement in unilateral posterior crossbite, if not treated in the primary dentition period, may lead to an undesirable growth modification which results in facial asymmetry of skeletal origin. Irregular tongue function and posture have also been diagnosed as important etiological factors. Early orthodontic treatment seems to be profitable and desirable to create conditions for normal dental, functional and skeletal development of the orofacial region. Treatment success after correction of unilateral posterior crossbite in the primary dentition is highly questionable, as it is very difficult to objectively assess correction of facial asymmetry and irregular tongue function and posture in small, growing children. Although facial photography is an important diagnostic tool in orthodontics, its main disadvantage is that it represents a three dimensional subject in two dimensions. Tongue posture and function during clinical examination are difficult to assess and is therefore unreliable. Contemporary 3D diagnostics in unilateral posterior crossbite enables uninvasive, valid and objective assessment of facial morphology, palatal volume, tongue function and posture. It can, therefore, become in the future an important part of morphological and functional diagnostics in orthodontics and dentofacial orthopedics before, during and after orthodontic treatment.

  17. Brownian limits, local limits, extreme value and variance asymptotics for convex hulls in the ball

    CERN Document Server

    Calka, Pierre; Yukich, J E

    2009-01-01

    The paper of Schreiber and Yukich [40] establishes an asymptotic representation for random convex polytope geometry in the unit ball $\\B_d, d \\geq 2,$ in terms of the general theory of stabilizing functionals of Poisson point processes as well as in terms of the so-called generalized paraboloid growth process. This paper further exploits this connection, introducing also a dual object termed the paraboloid hull process. Via these growth processes we establish local functional and measure-level limit theorems for the properly scaled radius-vector and support functions as well as for curvature measures and $k$-face empirical measures of convex polytopes generated by high density Poisson samples. We use general techniques of stabilization theory to establish Brownian sheet limits for the defect volume and mean width functionals, and we provide explicit variance asymptotics and central limit theorems for the $k$-face and intrinsic volume functionals. We establish extreme value theorems for radius-vector and suppo...

  18. Sampling algorithms

    CERN Document Server

    Tillé, Yves

    2006-01-01

    Important progresses in the methods of sampling have been achieved. This book draws up an inventory of methods that can be useful for selecting samples. Forty-six sampling methods are described in the framework of general theory. This book is suitable for experienced statisticians who are familiar with the theory of survey sampling.

  19. Balanced sampling

    NARCIS (Netherlands)

    Brus, D.J.

    2015-01-01

    In balanced sampling a linear relation between the soil property of interest and one or more covariates with known means is exploited in selecting the sampling locations. Recent developments make this sampling design attractive for statistical soil surveys. This paper introduces balanced sampling

  20. Sample Design.

    Science.gov (United States)

    Ross, Kenneth N.

    1987-01-01

    This article considers various kinds of probability and non-probability samples in both experimental and survey studies. Throughout, how a sample is chosen is stressed. Size alone is not the determining consideration in sample selection. Good samples do not occur by accident; they are the result of a careful design. (Author/JAZ)

  1. Balanced sampling

    NARCIS (Netherlands)

    Brus, D.J.

    2015-01-01

    In balanced sampling a linear relation between the soil property of interest and one or more covariates with known means is exploited in selecting the sampling locations. Recent developments make this sampling design attractive for statistical soil surveys. This paper introduces balanced sampling

  2. Slice Sampling

    CERN Document Server

    Neal, R M

    2000-01-01

    Markov chain sampling methods that automatically adapt to characteristics of the distribution being sampled can be constructed by exploiting the principle that one can sample from a distribution by sampling uniformly from the region under the plot of its density function. A Markov chain that converges to this uniform distribution can be constructed by alternating uniform sampling in the vertical direction with uniform sampling from the horizontal `slice' defined by the current vertical position, or more generally, with some update that leaves the uniform distribution over this slice invariant. Variations on such `slice sampling' methods are easily implemented for univariate distributions, and can be used to sample from a multivariate distribution by updating each variable in turn. This approach is often easier to implement than Gibbs sampling, and more efficient than simple Metropolis updates, due to the ability of slice sampling to adaptively choose the magnitude of changes made. It is therefore attractive f...

  3. A Mars Sample Return Sample Handling System

    Science.gov (United States)

    Wilson, David; Stroker, Carol

    2013-01-01

    We present a sample handling system, a subsystem of the proposed Dragon landed Mars Sample Return (MSR) mission [1], that can return to Earth orbit a significant mass of frozen Mars samples potentially consisting of: rock cores, subsurface drilled rock and ice cuttings, pebble sized rocks, and soil scoops. The sample collection, storage, retrieval and packaging assumptions and concepts in this study are applicable for the NASA's MPPG MSR mission architecture options [2]. Our study assumes a predecessor rover mission collects samples for return to Earth to address questions on: past life, climate change, water history, age dating, understanding Mars interior evolution [3], and, human safety and in-situ resource utilization. Hence the rover will have "integrated priorities for rock sampling" [3] that cover collection of subaqueous or hydrothermal sediments, low-temperature fluidaltered rocks, unaltered igneous rocks, regolith and atmosphere samples. Samples could include: drilled rock cores, alluvial and fluvial deposits, subsurface ice and soils, clays, sulfates, salts including perchlorates, aeolian deposits, and concretions. Thus samples will have a broad range of bulk densities, and require for Earth based analysis where practical: in-situ characterization, management of degradation such as perchlorate deliquescence and volatile release, and contamination management. We propose to adopt a sample container with a set of cups each with a sample from a specific location. We considered two sample cups sizes: (1) a small cup sized for samples matching those submitted to in-situ characterization instruments, and, (2) a larger cup for 100 mm rock cores [4] and pebble sized rocks, thus providing diverse samples and optimizing the MSR sample mass payload fraction for a given payload volume. We minimize sample degradation by keeping them frozen in the MSR payload sample canister using Peltier chip cooling. The cups are sealed by interference fitted heat activated memory

  4. The VIMOS VLT Deep Survey: the redshift distribution N(z) of magnitude-limited samples down to iAB=24.75 and KsAB=22

    CERN Document Server

    Fevre, O Le; Cucciati, O; de la Torre, S; Garilli, B; Ilbert, O; Brun, V Le; Maccagni, D; Tresse, L; Zamorani, G; Bardelli, S; Bolzonella, M; Contini, T; Iovino, A; Lopez-Sanjuan, C; McCracken, H J; Pollo, A; Pozzetti, L; Scodeggio, M; Tasca, L; Vergani, D; Zanichelli, A; Zucca, E

    2013-01-01

    We measure and analyse the redshift distribution N(z) of magnitude-selected samples using spectroscopic redshift measurement from the magnitude-selected VIMOS VLT Deep Survey (VVDS) with 172. Down to iAB2 than in colour-colour selected samples, and we use the magnitude-selected VVDS to emphasize the large uncertainties associated to other surveys using colour or colour-colour selected samples. Our results further demonstrate that semi-analytical models on dark matter simulations have yet to find the right balance of physical processes and time-scales to properly reproduce a fundamental galaxy population property like the observed N(z).

  5. 限制性输液复苏法对失血性休克孕兔血流动力学变化的影响%Effect of limited volume resuscitation on hemodynamic changes in pregnant rabbit with hemorrhagic shock

    Institute of Scientific and Technical Information of China (English)

    余艳红; 赵克森; 龚时鹏

    2008-01-01

    Objective To determine the effects of two fluid resuscitation strategies on the changes of hemodynamic variables,serum concentration of tumor necrosis factor-alpha(TNF-α)and interleukin-6 (IL-6)in a clinically relevant model of uncontrolled hemorrhagic shock in pregnant rabbits.Methods Hemorrhagic shock was induced by bleeding via carotied artery,followed by transection of a medium vessel in gestational sac.Experimental design consisted of three phases,shock phase(0-30 min),prehospital phase(30-90 min)and hospital phase(90-180 min).Twenty pregnant rabbits were randomly divided into two groups(n=10/group),aggressive fluid resuscitation group(PNL group)and limited volume resuscitation group(PLH group).In the shock phase,animals were hemorrhaged by blood withdrawal to mean arterial pressure(MAP)of 40-45 mm Hg(1 mm Hg=0.133 kPa)via carotid artery.In the prehospital phase,a medium vessel in the gestational sac was transected,then the animals in the PNL group and PLH group were resuscitated with 0.9% normal saline(NS)and shed blood to MAP of 80,60 mm Hg respectively.In the hospital phase,bleeding was controlled by surgical intervention and all the animals were reinfused with shed blood and NS to MAP 80 mm Hg.Hemodvnamic variables and respiration rate were monitored and blood samples were collected for TNF-α and IL-6 measurement.and finally subsequent volume resuscitation and survival rate were recorded.Results (1)At 120 min,the respiration rate and heart rate in the animals assigned to PLH group was(66±16)bpm,(235±41)bpm respectively,which were significantly lower than those in PNL group(P<0.01),while MAP and central venous pressure in the PLH group was(80.4±7.2)mm Hg,(8.0±4.4)cm H2O,respectively,which were significantly higher than those in PNL group(P<0.01);(2)The serum concentration of TNF-α,IL-6 of all the animals were markedly increased after hemorrhagic shock.and peak at 24 min.The serum concentration of TNF-α,IL-6 in animals assigned to PLH group were

  6. Microbiological surface sampling cart

    Science.gov (United States)

    Wilkins, J. R.; Mills, S. M.

    1972-01-01

    Mobile sampling cart automatically swabs surfaces for the recovery of microorganisms. Unit operates without human involvement and provides for control of swabbing speed, rotation of cotton swab, and the pressure and angle applied to swab. Capability of reverse direction is also available. Sampling cart use is limited to flat surfaces.

  7. Impact of Non-Gaussian Error Volumes on Conjunction Assessment Risk Analysis

    Science.gov (United States)

    Ghrist, Richard W.; Plakalovic, Dragan

    2012-01-01

    An understanding of how an initially Gaussian error volume becomes non-Gaussian over time is an important consideration for space-vehicle conjunction assessment. Traditional assumptions applied to the error volume artificially suppress the true non-Gaussian nature of the space-vehicle position uncertainties. For typical conjunction assessment objects, representation of the error volume by a state error covariance matrix in a Cartesian reference frame is a more significant limitation than is the assumption of linearized dynamics for propagating the error volume. In this study, the impact of each assumption is examined and isolated for each point in the volume. Limitations arising from representing the error volume in a Cartesian reference frame is corrected by employing a Monte Carlo approach to probability of collision (Pc), using equinoctial samples from the Cartesian position covariance at the time of closest approach (TCA) between the pair of space objects. A set of actual, higher risk (Pc >= 10 (exp -4)+) conjunction events in various low-Earth orbits using Monte Carlo methods are analyzed. The impact of non-Gaussian error volumes on Pc for these cases is minimal, even when the deviation from a Gaussian distribution is significant.

  8. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering

    KAUST Repository

    Sicat, Ronell Barrera

    2014-12-31

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.

  9. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering.

    Science.gov (United States)

    Sicat, Ronell; Krüger, Jens; Möller, Torsten; Hadwiger, Markus

    2014-12-01

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.

  10. [Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio]. Volume 3, Appendix A, Draft standard operating procedures and elements: Sampling and Analysis Plan (SAP): Phase 1, Task 4, Field Investigation, Draft

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    This report presents information concerning field procedures employed during the monitoring, well construction, well purging, sampling, and well logging at the Wright-Patterson Air Force Base. Activities were conducted in an effort to evaluate ground water contamination.

  11. Proposal for the assessment of quantitative dermal exposure limits in occupational environments: Part 2. Feasibility study for application in an exposure scenario for MDA by two different dermal exposure sampling methods

    NARCIS (Netherlands)

    Bos, P.M.J.; Brouwer, D.H.; Stevenson, H.; Hoogendoorn, L.; Boogaard, P.J.; Kort, W.L.A.M. de; Hemmen, J.J. van

    1998-01-01

    Objective. To evaluate two different techniques for assessing dermal exposure to 4,4'-methylene dianiline (MDA) in a field study. The results were used to test the applicability of a recently proposed quantitative dermal occupational exposure limit (DOEL) for MDA in a workplace scenario. Methods. Fo

  12. Verification of aerial photo stand volume tables for southeast Alaska.

    Science.gov (United States)

    Theodore S. Setzer; Bert R. Mead

    1988-01-01

    Aerial photo volume tables are used in the multilevel sampling system of Alaska Forest Inventory and Analysis. These volume tables are presented with a description of the data base and methods used to construct the tables. Volume estimates compiled from the aerial photo stand volume tables and associated ground-measured values are compared and evaluated.

  13. Special Issues Analysis Center (SIAC). Annual Report: Year Three. Volume V: Task Order D100 Report--An Analysis of Language Minority and Limited English Proficient Students from NELS:88. Task Order D150 Report--An Analysis of Educational Services for Language Minority and Limited English Proficient Early Elementary School Students Based on Prospects: The Congressionally Mandated Study of Compensatory Education.

    Science.gov (United States)

    Bennici, Frank J.; And Others

    Two reports concerning the education of limited-English-proficient (LEP) students are presented. The Task D100 report summarizes demographic characteristics and key research issues associated with high-school-age youth, including students and dropouts, who are identifiable as language minority and LEP in the National Educational Longitudinal Study…

  14. 大体积采样结合高分辨气相色谱-电子捕获负化学源-低分辨质谱法测定空气中的短链氯化石蜡%Determination of short-chain chlorinated paraffins in ambient air using high-volume sampling combined with high resolution gas chromatography-electron capture negative ion-low resolution mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    史蕾蒙; 高媛; 侯晓虹; 张海军; 张亦弛; 陈吉平

    2016-01-01

    建立了大体积采样结合高分辨气相色谱-电子捕获负化学源-低分辨质谱( HRGC-ECNI-LRMS)测定空气中短链氯化石蜡( SCCPs)的定量分析方法.联合使用酸化硅胶复合层析柱和碱性氧化铝层析柱净化处理空气样品中的 SCCPs,并对净化条件进行优化.使用该方法计算得到氯含量为58. 1%~63. 3%的 SCCPs系列标准储备溶液的总响应因子与氯含量线性相关,相关系数(R2)大于 0. 99.该方法的仪器检出限(S/N≥3)为 4. 2 pg,定量限(S/N≥10)为12 pg.SCCPs的方法检出限(MDL)为0. 34 ng/m3(n=7),实际样品加标回收率均达 80%以上.该方法灵敏度高、选择性好,能满足空气样品中 SCCPs的监测和分析需求.%An analytical method for quantifying short-chain chlorinated paraffins( SCCPs)in ambient air using high-volume sampling combined with high resolution gas chromatography-electron capture negative ion-low resolution mass spectrometry ( HRGC-ECNI-LRMS ) was developed. An acidified silica gel column and a basic alumina column were used to optimize the cleanup procedures. The results showed a good linearity(R2>0. 99)between the total response factors and the degree of chlorination of SCCPs in the content range of 58. 1%-63. 3%. The lim-its of detection( S/N≥3 ) and the limits of quantification( S/N≥10 ) were 4. 2 and 12 pg, respectively. The method detection limit( MDL)for SCCPs was 0. 34 ng/m 3( n=7). The recov-eries of SCCPs in air samples were in the range of 81. 9% to 94. 2%. It is demonstrated that the method is suitable for the quantitative analysis of SCCPs in air samples.

  15. A COMPATIBLE ESTIMATION MODEL OF STEM VOLUME AND TAPER FOR Acacia mangium Willd. PLANTATIONS

    Directory of Open Access Journals (Sweden)

    Haruni Krisnawati

    2016-04-01

    Full Text Available This study describes the establishment of a compatible volume estimation model for Acacia mangium Willd on the basis of 279 felled sample trees collected from the A. mangium plantation stands in South Sumatra, Indonesia. The model comprises of a total volume model and a stem taper model, which is compatible in the sense of the total volume obtained by integration of the taper model being equal to that computed by the total volume model. Several well-known total volume functions were evaluated including constant form factor, combined variable, generalized combine variable, logarithmic, generalized logarithmic and Honer transformed variables. A logarithmic model was determined to be the best and was then used as the basis for deriving the taper model. Appropriate statistical procedures were used in model fitting to account for the problems of heteroscedasticity and autocorrelation that are associated with the construction of volume and taper functions. The simultaneous fitting method of the Seemingly Unrelated Regression (SUR improved the parameter estimates and goodness-of-fit statistics while ensuring numeric consistency among the component models and reducing the total squared error obtained by an independent fitting method. The developed model can be used to estimate total stem volume, merchantable volume to any merchantability diameter limit at any height, and (possibly height of any diameter based on only easily measurable parameters such as diameter at breast height and total tree height for the species analysed.

  16. Language sampling

    DEFF Research Database (Denmark)

    Rijkhoff, Jan; Bakker, Dik

    1998-01-01

    This article has two aims: [1] to present a revised version of the sampling method that was originally proposed in 1993 by Rijkhoff, Bakker, Hengeveld and Kahrel, and [2] to discuss a number of other approaches to language sampling in the light of our own method. We will also demonstrate how our ...... sampling method is used with different genetic classifications (Voegelin & Voegelin 1977, Ruhlen 1987, Grimes ed. 1997) and argue that —on the whole— our sampling technique compares favourably with other methods, especially in the case of exploratory research.......This article has two aims: [1] to present a revised version of the sampling method that was originally proposed in 1993 by Rijkhoff, Bakker, Hengeveld and Kahrel, and [2] to discuss a number of other approaches to language sampling in the light of our own method. We will also demonstrate how our...

  17. Language sampling

    DEFF Research Database (Denmark)

    Rijkhoff, Jan; Bakker, Dik

    1998-01-01

    This article has two aims: [1] to present a revised version of the sampling method that was originally proposed in 1993 by Rijkhoff, Bakker, Hengeveld and Kahrel, and [2] to discuss a number of other approaches to language sampling in the light of our own method. We will also demonstrate how our...... sampling method is used with different genetic classifications (Voegelin & Voegelin 1977, Ruhlen 1987, Grimes ed. 1997) and argue that —on the whole— our sampling technique compares favourably with other methods, especially in the case of exploratory research....

  18. H∞ Design for Sampled-Data Systems via Lifting Technique:Conditions and Limitation%采样系统的提升法H∞设计:条件和局限性

    Institute of Scientific and Technical Information of China (English)

    王广雄; 刘彦文; 何联

    2006-01-01

    The initial motivation of the lifting technique is to solve the H∞ control problems.However, the conventional weighted H∞ design does not meet the conditions required by lifting, so the result often leads to a misjudgement of the design. Two conditions required by using the lifting technique are presented based on the basic formulae of the lifting. It is pointed out that only the H∞ disturbance attenuation problem with no weighting functions can meet these conditions, hence,the application of the lifting technique is quite limited.

  19. An H-alpha Imaging Survey of Galaxies in the Local 11 Mpc Volume

    CERN Document Server

    Kennicutt, Robert C; Jose Funes, S; Sakai, Shoko; Akiyama, Sanae

    2008-01-01

    As part of a broader effort to characterize the population of star-forming galaxies in the local universe, we have carried out an H-alpha+[NII] imaging survey for an essentially volume-limited sample of galaxies within 11 Mpc of the Milky Way. This paper describes the design of the survey, the observation, data processing, and calibration procedures, and the characteristics of the galaxy sample. The main product of the paper is a catalog of integrated H-alpha fluxes, luminosities, and equivalent widths for the galaxies in the sample. We briefly discuss the completeness properties of the survey and compare the distribution of the sample and its star formation properties to other large H-alpha imaging surveys. These data form the foundation for a series of follow-up studies of the star formation properties of the local volume, and the properties and duty cycles of star formation bursts in dwarf galaxies.

  20. Foaming volume and foam stability

    Science.gov (United States)

    Ross, Sydney

    1947-01-01

    A method of measuring foaming volume is described and investigated to establish the critical factors in its operation. Data on foaming volumes and foam stabilities are given for a series of hydrocarbons and for a range of concentrations of aqueous ethylene-glycol solutions. It is shown that the amount of foam formed depends on the machinery of its production as well as on properties of the liquid, whereas the stability of the foam produced, within specified mechanical limitations, is primarily a function of the liquid.

  1. Sampling Development

    Science.gov (United States)

    Adolph, Karen E.; Robinson, Scott R.

    2011-01-01

    Research in developmental psychology requires sampling at different time points. Accurate depictions of developmental change provide a foundation for further empirical studies and theories about developmental mechanisms. However, overreliance on widely spaced sampling intervals in cross-sectional and longitudinal designs threatens the validity of…

  2. Larger Thyroid Volume and Adequate Iodine Nutrition in Chinese Schoolchildren: Local Normative Reference Values Compared with WHO/IGN

    Directory of Open Access Journals (Sweden)

    Zhe Mo

    2016-01-01

    Full Text Available Objective. Thyroid volume measured by ultrasound to define goiter needs reliable local thyroid volume reference from iodine-sufficient populations. The aim of this study is to explore the reference interval for normal thyroid volume in schoolchildren aged 8–10 years from Zhejiang Province, China. Methods. A probability-proportionate-to-size sampling method was applied to select a representative sample of 1213 children aged 8–10 years in Zhejiang Province to detect the thyroid volume, salt iodine, and urine iodine. Results. Median urinary iodine concentration in involved schoolchildren was 178.30 (125.00 μg l−1, with the percentage of samples less than 100 μg l−1 as 12.69% and more than 300 μg l−1 as 15.25%. Thyroid volume was significantly correlated with age and anthropometric measurements independently of each other. The 97th percentile of thyroid volume in our study was larger generally than the new international reference. Conclusions. The iodine nutritional status in Zhejiang Province was at an adequate level. Despite some limitations in this study, we initially established the reference values for thyroid volume in 8–10-year-old schoolchildren in Zhejiang Province, China, as a local reference to be used for monitoring iodine deficiency disorders.

  3. Cryogenic Liquid Sample Acquisition System for Remote Space Applications

    Science.gov (United States)

    Mahaffy, Paul; Trainer, Melissa; Wegel, Don; Hawk, Douglas; Melek, Tony; Johnson, Christopher; Amato, Michael; Galloway, John

    2013-01-01

    There is a need to acquire autonomously cryogenic hydrocarbon liquid sample from remote planetary locations such as the lakes of Titan for instruments such as mass spectrometers. There are several problems that had to be solved relative to collecting the right amount of cryogenic liquid sample into a warmer spacecraft, such as not allowing the sample to boil off or fractionate too early; controlling the intermediate and final pressures within carefully designed volumes; designing for various particulates and viscosities; designing to thermal, mass, and power-limited spacecraft interfaces; and reducing risk. Prior art inlets for similar instruments in spaceflight were designed primarily for atmospheric gas sampling and are not useful for this front-end application. These cryogenic liquid sample acquisition system designs for remote space applications allow for remote, autonomous, controlled sample collections of a range of challenging cryogenic sample types. The design can control the size of the sample, prevent fractionation, control pressures at various stages, and allow for various liquid sample levels. It is capable of collecting repeated samples autonomously in difficult lowtemperature conditions often found in planetary missions. It is capable of collecting samples for use by instruments from difficult sample types such as cryogenic hydrocarbon (methane, ethane, and propane) mixtures with solid particulates such as found on Titan. The design with a warm actuated valve is compatible with various spacecraft thermal and structural interfaces. The design uses controlled volumes, heaters, inlet and vent tubes, a cryogenic valve seat, inlet screens, temperature and cryogenic liquid sensors, seals, and vents to accomplish its task.

  4. Depressive symptoms and brain volumes in older adults: a longitudinal magnetic resonance imaging study

    Science.gov (United States)

    Dotson, Vonetta M.; Davatzikos, Christos; Kraut, Michael A.; Resnick, Susan M.

    2009-01-01

    Background Late-life depression is associated with decreased brain volumes, particularly in frontal and temporal areas. Evidence suggests that depressive symptoms at a subclinical level are also associated with brain atrophy in these regions, but most of these associations are based on cross-sectional data. Our objective was to investigate both cross-sectional and longitudinal relations between sub-threshold depressive symptoms and brain volumes in older adults and to examine whether these associations are modified by age. Methods In total, 110 dementia-free adults from the neuroimaging substudy of the Baltimore Longitudinal Study of Aging aged 56 years and older at baseline participated in this study. Participants received annual evaluations for up to 9 years, during which structural magnetic resonance imaging (MRI) scans were acquired and depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale. Results Mean depressive symptom scores over time were associated with grey matter volume reductions in the left temporal lobe. Depressive symptoms were associated with brain volume reductions with advancing age in the cingulate gyrus and orbitofrontal cortex. Moreover, individuals with higher mean depressive symptom scores showed a faster rate of volume decline in left frontal white matter. Depressive symptoms were not associated with hippocampus volumes. Limitations Limitations include the relative homogeneity of our primarily white and highly educated sample, the lack of information about age at onset of depressive symptoms and potential limitations of the automated brain volume registration. Conclusion Our results suggest that depressive symptoms, even at a subthreshold level, are associated with volume reductions in specific frontal and temporal brain regions, particularly with advancing age. PMID:19721847

  5. 3-D EM exploration of the hepatic microarchitecture – lessons learned from large-volume in situ serial sectioning

    OpenAIRE

    Gerald John Shami; Delfine Cheng; Minh Huynh; Celien Vreuls; Eddie Wisse; Filip Braet

    2016-01-01

    To-date serial block-face scanning electron microscopy (SBF-SEM) dominates as the premier technique for generating three-dimensional (3-D) data of resin-embedded biological samples at an unprecedented depth volume. Given the infancy of the technique, limited literature is currently available regarding the applicability of SBF-SEM for the ultrastructural investigation of tissues. Herein, we provide a comprehensive and rigorous appraisal of five different SBF-SEM sample preparation protocols fo...

  6. The Spitzer Local Volume Legacy (LVL) Global Optical Photometry

    CERN Document Server

    Cook, David O; Johnson, Benjamin D; Van Zee, Liese; Lee, Janice C; Kennicutt, Robert C; Calzetti, Daniela; Staudaher, Shawn M; Engelbracht, Charles W

    2014-01-01

    We present the global optical photometry of 246 galaxies in the Local Volume Legacy (LVL) survey. The full volume-limited sample consists of 258 nearby (D < 11 Mpc) galaxies whose absolute B-band magnitude span a range of -9.6 < M_B < -20.7 mag. A composite optical (UBVR) data set is constructed from observed UBVR and SDSS ugriz imaging, where the ugriz magnitudes are transformed into UBVR. We present photometry within three galaxy apertures defined at UV, optical, and IR wavelengths. Flux comparisons between these apertures reveal that the traditional optical R25 galaxy apertures do not fully encompass extended sources. Using the larger IR apertures we find color-color relationships where later-type spiral and irregular galaxies tend to be bluer than earlier-type galaxies. These data provide the missing optical emission from which future LVL studies can construct the full panchromatic (UV-optical-IR) spectral energy distributions.

  7. Soil sampling kit and a method of sampling therewith

    Science.gov (United States)

    Thompson, Cyril V.

    1991-01-01

    A soil sampling device and a sample containment device for containing a soil sample is disclosed. In addition, a method for taking a soil sample using the soil sampling device and soil sample containment device to minimize the loss of any volatile organic compounds contained in the soil sample prior to analysis is disclosed. The soil sampling device comprises two close fitting, longitudinal tubular members of suitable length, the inner tube having the outward end closed. With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination. The inner closed end tube controls the volume of the sample taken and also serves to eject the sample. The soil sample containment device has a sealing member which is adapted to attach to an analytical apparatus which analyzes the volatile organic compounds contained in the sample. The soil sampling device in combination with the soil sample containment device allow an operator to obtain a soil sample containing volatile organic compounds and minimizing the loss of the volatile organic compounds prior to analysis of the soil sample for the volatile organic compounds.

  8. Small size sampling

    Directory of Open Access Journals (Sweden)

    Rakesh R. Pathak

    2012-02-01

    Full Text Available Based on the law of large numbers which is derived from probability theory, we tend to increase the sample size to the maximum. Central limit theorem is another inference from the same probability theory which approves largest possible number as sample size for better validity of measuring central tendencies like mean and median. Sometimes increase in sample-size turns only into negligible betterment or there is no increase at all in statistical relevance due to strong dependence or systematic error. If we can afford a little larger sample, statistically power of 0.90 being taken as acceptable with medium Cohen's d (<0.5 and for that we can take a sample size of 175 very safely and considering problem of attrition 200 samples would suffice. [Int J Basic Clin Pharmacol 2012; 1(1.000: 43-44

  9. Pressurized fluidized-bed hydroretorting of eastern oil shales. Volume 4, Task 5, Operation of PFH on beneficiated shale, Task 6, Environmental data and mitigation analyses and Task 7, Sample procurement, preparation, and characterization: Final report, September 1987--May 1991

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    The objective of Task 5 (Operation of Pressurized Fluidized-Bed Hydro-Retorting (PFH) on Beneficiated Shale) was to modify the PFH process to facilitate its use for fine-sized, beneficiated Eastern shales. This task was divided into 3 subtasks: Non-Reactive Testing, Reactive Testing, and Data Analysis and Correlations. The potential environment impacts of PFH processing of oil shale must be assessed throughout the development program to ensure that the appropriate technologies are in place to mitigate any adverse effects. The overall objectives of Task 6 (Environmental Data and Mitigation Analyses) were to obtain environmental data relating to PFH and shale beneficiation and to analyze the potential environmental impacts of the integrated PFH process. The task was divided into the following four subtasks. Characterization of Processed Shales (IGT), 6.2. Water Availability and Treatment Studies, 6.3. Heavy Metals Removal and 6.4. PFH Systems Analysis. The objective of Task 7 (Sample Procurement, Preparation, and Characterization) was to procure, prepare, and characterize raw and beneficiated bulk samples of Eastern oil shale for all of the experimental tasks in the program. Accomplishments for these tasks are presented.

  10. Optimizing Crystal Volume for Neutron Diffraction Studies

    Science.gov (United States)

    Snell, E. H.

    2003-01-01

    For structural studies with neutron diffraction more intense neutron sources, improved sensitivity detector and larger volume crystals are all means by which the science is being advanced to enable studies on a wider range of samples. We have chosen a simplistic approach using a well understood crystallization method, with minimal amounts of sample and using design of experiment techniques to maximize the crystal volume all for minimum effort. Examples of the application are given.

  11. Price-volume multifractal analysis and its application in Chinese stock markets

    Science.gov (United States)

    Yuan, Ying; Zhuang, Xin-tian; Liu, Zhi-ying

    2012-06-01

    An empirical research on Chinese stock markets is conducted using statistical tools. First, the multifractality of stock price return series, ri(ri=ln(Pt+1)-ln(Pt)) and trading volume variation series, vi(vi=ln(Vt+1)-ln(Vt)) is confirmed using multifractal detrended fluctuation analysis. Furthermore, a multifractal detrended cross-correlation analysis between stock price return and trading volume variation in Chinese stock markets is also conducted. It is shown that the cross relationship between them is also found to be multifractal. Second, the cross-correlation between stock price Pi and trading volume Vi is empirically studied using cross-correlation function and detrended cross-correlation analysis. It is found that both Shanghai stock market and Shenzhen stock market show pronounced long-range cross-correlations between stock price and trading volume. Third, a composite index R based on price and trading volume is introduced. Compared with stock price return series ri and trading volume variation series vi, R variation series not only remain the characteristics of original series but also demonstrate the relative correlation between stock price and trading volume. Finally, we analyze the multifractal characteristics of R variation series before and after three financial events in China (namely, Price Limits, Reform of Non-tradable Shares and financial crisis in 2008) in the whole period of sample to study the changes of stock market fluctuation and financial risk. It is found that the empirical results verified the validity of R.

  12. Abdominal fat volume estimation by stereology on CT: a comparison with manual planimetry

    Energy Technology Data Exchange (ETDEWEB)

    Manios, G.E.; Mazonakis, M.; Damilakis, J. [University of Crete, Department of Medical Physics, Faculty of Medicine, Heraklion, Crete (Greece); Voulgaris, C.; Karantanas, A. [University of Crete, Department of Radiology, Faculty of Medicine, Heraklion, Crete (Greece)

    2016-03-15

    To deploy and evaluate a stereological point-counting technique on abdominal CT for the estimation of visceral (VAF) and subcutaneous abdominal fat (SAF) volumes. Stereological volume estimations based on point counting and systematic sampling were performed on images from 14 consecutive patients who had undergone abdominal CT. For the optimization of the method, five sampling intensities in combination with 100 and 200 points were tested. The optimum stereological measurements were compared with VAF and SAF volumes derived by the standard technique of manual planimetry on the same scans. Optimization analysis showed that the selection of 200 points along with the sampling intensity 1/8 provided efficient volume estimations in less than 4 min for VAF and SAF together. The optimized stereology showed strong correlation with planimetry (VAF: r = 0.98; SAF: r = 0.98). No statistical differences were found between the two methods (VAF: P = 0.81; SAF: P = 0.83). The 95 % limits of agreement were also acceptable (VAF: -16.5 %, 16.1 %; SAF: -10.8 %, 10.7 %) and the repeatability of stereology was good (VAF: CV = 4.5 %, SAF: CV = 3.2 %). Stereology may be successfully applied to CT images for the efficient estimation of abdominal fat volume and may constitute a good alternative to the conventional planimetric technique. (orig.)

  13. Exposure render: an interactive photo-realistic volume rendering framework.

    Directory of Open Access Journals (Sweden)

    Thomas Kroes

    Full Text Available The field of volume visualization has undergone rapid development during the past years, both due to advances in suitable computing hardware and due to the increasing availability of large volume datasets. Recent work has focused on increasing the visual realism in Direct Volume Rendering (DVR by integrating a number of visually plausible but often effect-specific rendering techniques, for instance modeling of light occlusion and depth of field. Besides yielding more attractive renderings, especially the more realistic lighting has a positive effect on perceptual tasks. Although these new rendering techniques yield impressive results, they exhibit limitations in terms of their exibility and their performance. Monte Carlo ray tracing (MCRT, coupled with physically based light transport, is the de-facto standard for synthesizing highly realistic images in the graphics domain, although usually not from volumetric data. Due to the stochastic sampling of MCRT algorithms, numerous effects can be achieved in a relatively straight-forward fashion. For this reason, we have developed a practical framework that applies MCRT techniques also to direct volume rendering (DVR. With this work, we demonstrate that a host of realistic effects, including physically based lighting, can be simulated in a generic and flexible fashion, leading to interactive DVR with improved realism. In the hope that this improved approach to DVR will see more use in practice, we have made available our framework under a permissive open source license.

  14. Composite Sampling Approaches for Bacillus anthracis Surrogate Extracted from Soil.

    Directory of Open Access Journals (Sweden)

    Brian France

    Full Text Available Any release of anthrax spores in the U.S. would require action to decontaminate the site and restore its use and operations as rapidly as possible. The remediation activity would require environmental sampling, both initially to determine the extent of contamination (hazard mapping and post-decon to determine that the site is free of contamination (clearance sampling. Whether the spore contamination is within a building or outdoors, collecting and analyzing what could be thousands of samples can become the factor that limits the pace of restoring operations. To address this sampling and analysis bottleneck and decrease the time needed to recover from an anthrax contamination event, this study investigates the use of composite sampling. Pooling or compositing of samples is an established technique to reduce the number of analyses required, and its use for anthrax spore sampling has recently been investigated. However, use of composite sampling in an anthrax spore remediation event will require well-documented and accepted methods. In particular, previous composite sampling studies have focused on sampling from hard surfaces; data on soil sampling are required to extend the procedure to outdoor use. Further, we must consider whether combining liquid samples, thus increasing the volume, lowers the sensitivity of detection and produces false negatives. In this study, methods to composite bacterial spore samples from soil are demonstrated. B. subtilis spore suspensions were used as a surrogate for anthrax spores. Two soils (Arizona Test Dust and sterilized potting soil were contaminated and spore recovery with composites was shown to match individual sample performance. Results show that dilution can be overcome by concentrating bacterial spores using standard filtration methods. This study shows that composite sampling can be a viable method of pooling samples to reduce the number of analysis that must be performed during anthrax spore remediation.

  15. Composite Sampling Approaches for Bacillus anthracis Surrogate Extracted from Soil

    Science.gov (United States)

    France, Brian; Bell, William; Chang, Emily; Scholten, Trudy

    2015-01-01

    Any release of anthrax spores in the U.S. would require action to decontaminate the site and restore its use and operations as rapidly as possible. The remediation activity would require environmental sampling, both initially to determine the extent of contamination (hazard mapping) and post-decon to determine that the site is free of contamination (clearance sampling). Whether the spore contamination is within a building or outdoors, collecting and analyzing what could be thousands of samples can become the factor that limits the pace of restoring operations. To address this sampling and analysis bottleneck and decrease the time needed to recover from an anthrax contamination event, this study investigates the use of composite sampling. Pooling or compositing of samples is an established technique to reduce the number of analyses required, and its use for anthrax spore sampling has recently been investigated. However, use of composite sampling in an anthrax spore remediation event will require well-documented and accepted methods. In particular, previous composite sampling studies have focused on sampling from hard surfaces; data on soil sampling are required to extend the procedure to outdoor use. Further, we must consider whether combining liquid samples, thus increasing the volume, lowers the sensitivity of detection and produces false negatives. In this study, methods to composite bacterial spore samples from soil are demonstrated. B. subtilis spore suspensions were used as a surrogate for anthrax spores. Two soils (Arizona Test Dust and sterilized potting soil) were contaminated and spore recovery with composites was shown to match individual sample performance. Results show that dilution can be overcome by concentrating bacterial spores using standard filtration methods. This study shows that composite sampling can be a viable method of pooling samples to reduce the number of analysis that must be performed during anthrax spore remediation. PMID:26714315

  16. Composite Sampling Approaches for Bacillus anthracis Surrogate Extracted from Soil.

    Science.gov (United States)

    France, Brian; Bell, William; Chang, Emily; Scholten, Trudy

    2015-01-01

    Any release of anthrax spores in the U.S. would require action to decontaminate the site and restore its use and operations as rapidly as possible. The remediation activity would require environmental sampling, both initially to determine the extent of contamination (hazard mapping) and post-decon to determine that the site is free of contamination (clearance sampling). Whether the spore contamination is within a building or outdoors, collecting and analyzing what could be thousands of samples can become the factor that limits the pace of restoring operations. To address this sampling and analysis bottleneck and decrease the time needed to recover from an anthrax contamination event, this study investigates the use of composite sampling. Pooling or compositing of samples is an established technique to reduce the number of analyses required, and its use for anthrax spore sampling has recently been investigated. However, use of composite sampling in an anthrax spore remediation event will require well-documented and accepted methods. In particular, previous composite sampling studies have focused on sampling from hard surfaces; data on soil sampling are required to extend the procedure to outdoor use. Further, we must consider whether combining liquid samples, thus increasing the volume, lowers the sensitivity of detection and produces false negatives. In this study, methods to composite bacterial spore samples from soil are demonstrated. B. subtilis spore suspensions were used as a surrogate for anthrax spores. Two soils (Arizona Test Dust and sterilized potting soil) were contaminated and spore recovery with composites was shown to match individual sample performance. Results show that dilution can be overcome by concentrating bacterial spores using standard filtration methods. This study shows that composite sampling can be a viable method of pooling samples to reduce the number of analysis that must be performed during anthrax spore remediation.

  17. Influence of bress laminate volume fraction on electromechanical properties of externally laminated coated conductor tapes

    Energy Technology Data Exchange (ETDEWEB)

    Bautista, Zhierwinjay M.; Shin, Hyung Seop [Dept. of Mechanical Design Engineering, Andong National University, Andong (Korea, Republic of); Lee, Jae Hun; Lee, Hun Ju; Moon, Seung Hyun [SuNAM Co Ltd., Anseong (Korea, Republic of)

    2016-09-15

    The enhancement of mechanical properties of coated conductor (CC) tapes in practical application are usually achieved by reinforcing through lamination or electroplating metal layers on either sides of the CC tape. Mechanical or electromechanical properties of the CC tapes have been largely affected by the lamination structure under various loading modes such as tension, bending or even cyclic. In this study, the influence of brass laminate volume fraction on electromechanical properties of RCE-DR processed Gadolinium-barium-copper-oxide (GdBCO) CC tapes was investigated. The samples used were composed of single-side and both-side laminate of brass layer to the Cu-stabilized CC tape and their Ic behaviors were compared to those of the Cu-stabilized CC tape without external lamination. The stress/strain dependences of Ic in laminated CC tapes under uniaxial tension were analyzed and the irreversible stress/strain limits were determined. As a result, the increase of brass laminate volume fraction initially increased the irreversible strain limit and became gradual. The corresponding irreversible stress limit, however, showed no difference even though the brass laminate volume fraction increased to 3.4. But the irreversible load limit linearly increased with the brass laminate volume fraction.

  18. Enhanced performance large volume dissolution-DNP

    DEFF Research Database (Denmark)

    Bowen, Sean; Ardenkjær-Larsen, Jan Henrik

    2014-01-01

    A systematic study of the performance of the dissolution process in dissolution-DNP is presented. A relatively simple set of modifications is made to the standard Hypersense dissolution system to enable polarization of large volume samples. These consist of a large volume sample cup along...... with supporting modifications to the dissolution head and related components. Additional modifications were made to support the mapping of the temperature/pressure space of the dissolution process as well as enabling the use of large volumes of solvent and improving the robustness of the system. No loss...

  19. Determination of Cu, Zn, and Se in microvolumes of liquid biological samples

    Science.gov (United States)

    Shaban, H. A.; Shaltout, A. A.; Abdou, M.; Al Ashker, E. A.; Elgohary, M.

    2011-01-01

    Cu, Zn, and Se were successfully determined in a few microliters (<100 μl) of biological samples using discrete injection atomic absorption spectrometry. Different factors were investigated in order to obtain a biological sample volume which is valid for analysis. Among them are the effect of microsampling volume variations (starting from 40 to 200 μl), nebulization efficiency, detection limits, precision, and finally the calibration and sensitivity of the proposed method. It was found that 60 μl of the biological sample was adequate for the quantitative analysis with reasonable precision. The advantages of the proposed method are not only rapidity, simplicity, sensitivity, and good precision, but also, contrary to conventional flame atomic absorption spectrometry, the capability of analyzing microvolumes of samples.

  20. Thermal Desorption Capability Development for Enhanced On-site Health Risk Assessment: HAPSITE (registered trademark) ER Passive Sampling in the Field

    Science.gov (United States)

    2015-06-07

    C). The sampling rate limits the practical volatility range of compounds of interest to those with volatilities less than or equal to benzene due...injects known volumes of internal standards bromopentafluorobenzene and 1,3,5- tris(trifluoromethyl) benzene (5.44 ppm and 10.83 ppm, respectively) for...to simulate the addition of the diffusion cap to sampling tubes, then recapped during the sampling period. This simulates any compound that adsorbs

  1. Work sampling

    OpenAIRE

    Salas Bacalla, julio; FII-UNMSM

    2014-01-01

    Work sampling is a method of indirect measurement, which means instantaneous observations, to determine the amount of uptime or downtime in a production process El muestreo de trabajo es un método de medición indirecto, que mediante observaciones instantaneas, permite determinar la cantidad de tiempo en actividad o inactividad en un proceso productivo

  2. Insular volume reduction in schizophrenia.

    Science.gov (United States)

    Saze, Teruyasu; Hirao, Kazuyuki; Namiki, Chihiro; Fukuyama, Hidenao; Hayashi, Takuji; Murai, Toshiya

    2007-12-01

    Structural and functional abnormalities of the insular cortex have been reported in patients with schizophrenia. Most studies have shown that the insular volumes in schizophrenia patients are smaller than those of healthy people. As the insular cortex is functio-anatomically divided into anterior and posterior subdivisons, recent research is focused on uncovering a specific subdivisional abnormality of the insula in patients with schizophrenia. A recent ROI-based volumetric MRI study demonstrated specific left anterior insular volume reduction in chronic schizophrenia patients (Makris N, Goldstein J, Kennedy D, Hodge S, Caviness V, Faraone S, Tsuang M, Seidman L (2006) Decreased volume of left and total anterior insular lobule in schizophrenia. Schizophr Res 83:155-171). On the other hand, our VBM-based volumetric study revealed a reduction in right posterior insular volume (Yamada M, Hirao K, Namiki C, Hanakawa T, Fukuyama H, Hayashi T, Murai T (2007) Social cognition and frontal lobe pathology in schizophrenia: a voxel-based morphometric study. NeuroImage 35:292-298). In order to address these controversial results, ROI-based subdivisional volumetry was performed using the MRI images from the same population we analyzed in our previous VBM-study. The sample group comprised 20 schizophrenia patients and 20 matched healthy controls. Patients with schizophrenia showed a global reduction in insular gray matter volumes relative to healthy comparison subjects. In a simple comparison of the volumes of each subdivision between the groups, a statistically significant volume reduction in patients with schizophrenia was demonstrated only in the right posterior insula. This study suggests that insular abnormalities in schizophrenia would include anterior as well as posterior parts. Each subdivisional abnormality may impact on different aspects of the pathophysiology and psychopathology of schizophrenia; these relationships should be the focus of future research.

  3. Ovarian volume throughout life

    DEFF Research Database (Denmark)

    Kelsey, Thomas W; Dodwell, Sarah K; Wilkinson, A Graham

    2013-01-01

    cancer. To date there is no normative model of ovarian volume throughout life. By searching the published literature for ovarian volume in healthy females, and using our own data from multiple sources (combined n=59,994) we have generated and robustly validated the first model of ovarian volume from...... to about 2.8 mL (95% CI 2.7-2.9 mL) at the menopause and smaller volumes thereafter. Our model allows us to generate normal values and ranges for ovarian volume throughout life. This is the first validated normative model of ovarian volume from conception to old age; it will be of use in the diagnosis...

  4. Study of limiting dosimetric parameters on lung pathology. Differences in the use of the lung-gtv and lung-ptv volumes; Estudio de los parametros dosimetricos limitantes en la patologia de pulmon diferencias en ul uso de los volumenes pulmon-gtv y pulmo-ptv

    Energy Technology Data Exchange (ETDEWEB)

    Granero Cabanero, D.; Almendros Blanco, P.; Garcia Hernanez, T.; Vicedo gonzalez, A.; Brualla, L.; Hernandez, A.; Solera, C.; Serrano, A.; Rosello, J.

    2013-07-01

    The objective of this work is to study the differences between the use of the volume of lung-GTV and lung-PTV to assess pulmonary toxicity and also to study the relationships between parameters V13, V20, V30, and mean dose of volumes lung, lung-PTV and lung-GTV. It was studied also the possible relationship between volumes of GTV, PTV and volume of lung with the dosimetric parameters described above. (Author)

  5. Sampling Strategy

    Science.gov (United States)

    2008-01-01

    Three locations to the right of the test dig area are identified for the first samples to be delivered to the Thermal and Evolved Gas Analyzer (TEGA), the Wet Chemistry Lab (WCL), and the Optical Microscope (OM) on NASA's Phoenix Mars Lander. These sampling areas are informally labeled 'Baby Bear', 'Mama Bear', and 'Papa Bear' respectively. This image was taken on the seventh day of the Mars mission, or Sol 7 (June 1, 2008) by the Surface Stereo Imager aboard NASA's Phoenix Mars Lander. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  6. Mean nuclear volume

    DEFF Research Database (Denmark)

    Mogensen, O.; Sørensen, Flemming Brandt; Bichel, P.

    1999-01-01

    We evaluated the following nine parameters with respect to their prognostic value in females with endometrial cancer: four stereologic parameters [mean nuclear volume (MNV), nuclear volume fraction, nuclear index and mitotic index], the immunohistochemical expression of cancer antigen (CA125...

  7. Ultimate physical limits to computation

    CERN Document Server

    Lloyd, S

    1999-01-01

    Computers are physical systems: what they can and cannot do is dictated by the laws of physics. In particular, the speed with which a physical device can process information is limited by its energy, and the amount of information that it can process is limited by the number of degrees of freedom it possesses. The way in which it processes information is determined by the forces of nature that the computer has at its disposal. This paper explores the fundamental physical limits of computation as determined by the speed of light c, the quantum scale as given by Planck's constant h, and the gravitational constant G. As an example, quantitative bounds are put to the computational power of an `ultimate laptop' with a mass of one kilogram confined to a volume of one liter.

  8. Magnetic Lenz lenses increase the limit-of-detection in nuclear magnetic resonance

    CERN Document Server

    Spengler, Nils; Meissner, Markus V; Wallrabe, Ulrike; Korvink, Jan G

    2016-01-01

    A high NMR detection sensitivity is indispensable when dealing with mass and volume-limited samples, or whenever a high spatial resolution is required. The use of miniaturised RF coils is a proven way to increase sensitivity, but may be impractical and is not applicable to every experimental situation. We present the use of magnetic lenses, denoted as Lenz lenses due to their working principle, to focus the magnetic flux of a macroscopic RF coil into a smaller volume and thereby locally enhance the sensitivity of the NMR experiment - at the expense of the total sensitive volume. Besides focusing, such lenses facilitate re-guiding or re-shaping of magnetic fields much like optical lenses do with light beams. For the first time we experimentally demonstrate the use of Lenz lenses in magnetic resonance and provide a compact mathematical description of the working principle. Through simulations we show that optimal arrangements can be found.

  9. Sample Return Systems for Extreme Environments Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Since the Apollo era, sample return missions have been primarily limited to asteroid sampling. More comprehensive sampling could yield critical information on the...

  10. Sampling considerations when analyzing micrometric-sized particles in a liquid jet using laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Faye, C.B.; Amodeo, T.; Fréjafon, E. [Institut National de l' Environnement Industriel et des Risques (INERIS/DRC/CARA/NOVA), Parc Technologique Alata, BP 2, 60550 Verneuil-En-Halatte (France); Delepine-Gilon, N. [Institut des Sciences Analytiques, 5 rue de la Doua, 69100 Villeurbanne (France); Dutouquet, C., E-mail: christophe.dutouquet@ineris.fr [Institut National de l' Environnement Industriel et des Risques (INERIS/DRC/CARA/NOVA), Parc Technologique Alata, BP 2, 60550 Verneuil-En-Halatte (France)

    2014-01-01

    Pollution of water is a matter of concern all over the earth. Particles are known to play an important role in the transportation of pollutants in this medium. In addition, the emergence of new materials such as NOAA (Nano-Objects, their Aggregates and their Agglomerates) emphasizes the need to develop adapted instruments for their detection. Surveillance of pollutants in particulate form in waste waters in industries involved in nanoparticle manufacturing and processing is a telling example of possible applications of such instrumental development. The LIBS (laser-induced breakdown spectroscopy) technique coupled with the liquid jet as sampling mode for suspensions was deemed as a potential candidate for on-line and real time monitoring. With the final aim in view to obtain the best detection limits, the interaction of nanosecond laser pulses with the liquid jet was examined. The evolution of the volume sampled by laser pulses was estimated as a function of the laser energy applying conditional analysis when analyzing a suspension of micrometric-sized particles of borosilicate glass. An estimation of the sampled depth was made. Along with the estimation of the sampled volume, the evolution of the SNR (signal to noise ratio) as a function of the laser energy was investigated as well. Eventually, the laser energy and the corresponding fluence optimizing both the sampling volume and the SNR were determined. The obtained results highlight intrinsic limitations of the liquid jet sampling mode when using 532 nm nanosecond laser pulses with suspensions. - Highlights: • Micrometric-sized particles in suspensions are analyzed using LIBS and a liquid jet. • The evolution of the sampling volume is estimated as a function of laser energy. • The sampling volume happens to saturate beyond a certain laser fluence. • Its value was found much lower than the beam diameter times the jet thickness. • Particles proved not to be entirely vaporized.

  11. A dispersal-limited sampling theory for species and alleles

    NARCIS (Netherlands)

    Etienne, R.S.; Alonso, D.

    2005-01-01

    The importance of dispersal for biodiversity has long been recognized. However, it was never advertised as vigorously as Stephen Hubbell did in the context of his neutral community theory. After his book appeared in 2001, several scientists have sought and found analytical expressions for the effect

  12. Limited-sampling strategies for anidulafungin in critically ill patients

    NARCIS (Netherlands)

    van Wanrooy, Marjolijn J.P.; Proost, Johannes H.; Rodgers, Michael G. G.; Zijlstra, Jan G.; Uges, Donald R.A.; Kosterink, Jos G.W.; van der Werf, Tjip S.; Alffenaar, Jan-Willem C.

    2015-01-01

    Efficacy of anidulafungin is driven by the area under the concentration-time curve (AUC)/MIC ratio. Determination of the anidulafungin AUC along with MIC values can therefore be useful. Since obtaining a full concentration-time curve to determine an AUC is not always feasible or appropriate,

  13. Multibeam volume acoustic backscatter imagery and reverberation measurements in the northeastern Gulf of Mexico

    Science.gov (United States)

    Gallaudet, Timothy C.; deMoustier, Christian P.

    2002-08-01

    Multibeam volume acoustic backscatter imagery and reverberation measurements are derived from data collected in 200-m-deep waters in the northeastern Gulf of Mexico, with the Toroidal Volume Search Sonar (TVSS), a 68-kHz cylindrical sonar operated by the U.S. Navy's Coastal System Station. The TVSS's 360-degree vertical imaging plane allows simultaneous identification of multiple volume scattering sources and their discrimination from backscatter at the sea surface or the seafloor. This imaging capability is used to construct a three-dimensional representation of a pelagic fish school near the bottom. Scattering layers imaged in the mixed layer and upper thermocline are attributed to assemblages of epipelagic zooplankton. The fine scale patchiness of these scatterers is assessed with the two-dimensional variance spectra of vertical volume scattering strength images in the upper and middle water column. Mean volume reverberation levels exhibit a vertical directionality which is attributed to the volume scattering layers. Boundary echo sidelobe interference and reverberation is shown to be the major limitation in obtaining bioacoustic data with the TVSS. Because net tow and trawl samples were not collected with the acoustic data, the analysis presented is based upon comparison to previous biologic surveys in the northeastern Gulf of Mexico and reference to the bioacoustic literature. copyright 2002 Acoustical Society of America.

  14. Extravehicular activities limitations study. Volume 1: Physiological limitations to extravehicular activity in space

    Science.gov (United States)

    Furr, Paul A.; Monson, Conrad B.; Santoro, Robert L.; Sears, William J.; Peterson, Donald H.; Smith, Malcolm

    1988-01-01

    This report contains the results of a comprehensive literature search on physiological aspects of EVA. Specifically, the topics covered are: (1) Oxygen levels; (2) Optimum EVA work; (3) Food and Water; (4) Carbon dioxide levels; (5) Repetitive decompressions; (6) Thermal, and (7) Urine collection. The literature was assessed on each of these topics, followed by statements on conclusions and recommended future research needs.

  15. Zooplankton Displacement Volume in Glacier Bay, Alaska, 2004

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset includes zooplankton displacement volume sampled in Glacier Bay National Park during summer of 2004. Zooplankton were sampled with a multinet with a 0.5...

  16. Finite-volume scheme for anisotropic diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Es, Bram van, E-mail: bramiozo@gmail.com [Centrum Wiskunde & Informatica, P.O. Box 94079, 1090GB Amsterdam (Netherlands); FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, The Netherlands" 1 (Netherlands); Koren, Barry [Eindhoven University of Technology (Netherlands); Blank, Hugo J. de [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, The Netherlands" 1 (Netherlands)

    2016-02-01

    In this paper, we apply a special finite-volume scheme, limited to smooth temperature distributions and Cartesian grids, to test the importance of connectivity of the finite volumes. The area of application is nuclear fusion plasma with field line aligned temperature gradients and extreme anisotropy. We apply the scheme to the anisotropic heat-conduction equation, and compare its results with those of existing finite-volume schemes for anisotropic diffusion. Also, we introduce a general model adaptation of the steady diffusion equation for extremely anisotropic diffusion problems with closed field lines.

  17. Airflow limitation is accompanied by diaphragm dysfunction.

    Science.gov (United States)

    Hellebrandová, L; Chlumský, J; Vostatek, P; Novák, D; Rýznarová, Z; Bunc, V

    2016-07-18

    Chronic airflow limitation, caused by chronic obstructive pulmonary disease (COPD) or by asthma, is believed to change the shape and the position of the diaphragm due to an increase in lung volume. We have made a comparison of magnetic resonance imaging (MRI) of diaphragm in supine position with pulmonary functions, respiratory muscle function and exercise tolerance. We have studied the differences between patients with COPD, patients with asthma, and healthy subjects. Most interestingly we found the lung hyperinflation leads to the changes in diaphragmatic excursions during the breathing cycle, seen in the differences between the maximal expiratory diaphragm position (DPex) in patients with COPD and control group (p=0.0016). The magnitude of the diaphragmatic dysfunction was significantly related to the airflow limitation expressed by the ratio of forced expiratory volume in 1 s to slow vital capacity (FEV(1)/SVC), (%, p=0.0007); to the lung hyperinflation expressed as the ratio of the residual volume to total lung capacity (RV/TLC), (%, p=0.0018) and the extent of tidal volume constrain expressed as maximal tidal volume (V(Tmax)), ([l], p=0.0002); and the ratio of tidal volume to slow vital capacity (V(T)/SVC), (p=0.0038) during submaximal exercise. These results suggest that diaphragmatic movement fails to contribute sufficiently to the change in lung volume in emphysema. Tests of respiratory muscle function were related to the position of the diaphragm in deep expiration, e.g. neuromuscular coupling (P(0.1)/V(T)) (p=0.0232). The results have shown that the lung volumes determine the position of the diaphragm and function of the respiratory muscles. Chronic airflow limitation seems to change the position of the diaphragm, which thereafter influences inspiratory muscle function and exercise tolerance. There is an apparent relationship between the position of the diaphragm and the pulmonary functions and exercise tolerance.

  18. Pre-concentration of uranium from water samples by dispersive liquid-liquid micro-extraction

    Energy Technology Data Exchange (ETDEWEB)

    Khajeh, Mostafa; Nemch, Tabandeh Karimi [Zabol Univ. (Iran, Islamic Republic of). Dept. of Chemistry

    2014-07-01

    In this study, a simple and rapid dispersive liquid-liquid microextraction (DLLME) was developed for the determination of uranium in water samples prior to high performance liquid chromatography with diode array detection. 1-(2-pyridylazo)-2-naphthol (PAN) was used as complexing agent. The effect of various parameters on the extraction step including type and volume of extraction and dispersive solvents, pH of solution, concentration of PAN, extraction time, sample volume and ionic strength were studied and optimized. Under the optimum conditions, the limit of detection (LOD) and preconcentration factor were 0.3 μg L{sup -1} and 194, respectively. Furthermore, the relative standard deviation of the ten replicate was <2.6%. The developed procedure was then applied to the extraction and determination of uranium in the water samples.

  19. High Volume Air Sampling for Viral Aerosols: A Comparative Approach

    Science.gov (United States)

    2010-03-01

    are shown to be very effective. Meltzer et al. modeled potential response strategies to a release of smallpox as a biowarfare agent. Quarantine and...isolated starting 30 days after agent release and projected that by 240 days post release no new cases would occur ( Meltzer , Damon, LeDuc, & Millar...lpm). The study found that found that for flow rates less than 2.5 lpm, very little media depression occurs in the AGI-30 and the fluid remains

  20. Waste minimization handbook, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Boing, L.E.; Coffey, M.J.

    1995-12-01

    This technical guide presents various methods used by industry to minimize low-level radioactive waste (LLW) generated during decommissioning and decontamination (D and D) activities. Such activities generate significant amounts of LLW during their operations. Waste minimization refers to any measure, procedure, or technique that reduces the amount of waste generated during a specific operation or project. Preventive waste minimization techniques implemented when a project is initiated can significantly reduce waste. Techniques implemented during decontamination activities reduce the cost of decommissioning. The application of waste minimization techniques is not limited to D and D activities; it is also useful during any phase of a facility`s life cycle. This compendium will be supplemented with a second volume of abstracts of hundreds of papers related to minimizing low-level nuclear waste. This second volume is expected to be released in late 1996.

  1. Determination of the Limiting Magnitude

    Science.gov (United States)

    Kingery, Aaron; Blaauw, Rhiannon

    2017-01-01

    The limiting magnitude of an optical camera system is an important property to understand since it is used to find the completeness limit of observations. Limiting magnitude depends on the hardware and software of the system, current weather conditions, and the angular speed of the objects observed. If an object exhibits a substantial angular rate during the exposure, its light spreads out over more pixels than the stationary stars. This spreading causes the limiting magnitude to be brighter when compared to the stellar limiting magnitude. The effect, which begins to become important when the object moves a full width at half max during a single exposure or video frame. For targets with high angular speeds or camera systems with narrow field of view or long exposures, this correction can be significant, up to several magnitudes. The stars in an image are often used to measure the limiting magnitude since they are stationary, have known brightness, and are present in large numbers, making the determination of the limiting magnitude fairly simple. In order to transform stellar limiting magnitude to object limiting magnitude, a correction must be applied accounting for the angular velocity. This technique is adopted in meteor and other fast-moving object observations, as the lack of a statistically significant sample of targets makes it virtually impossible to determine the limiting magnitude before the weather conditions change. While the weather is the dominant factor in observing satellites, the limiting magnitude for meteors also changes throughout the night due to the motion of a meteor shower or sporadic source radiant across the sky. This paper presents methods for determining the limiting stellar magnitude and the conversion to the target limiting magnitude.

  2. A law of large numbers for limit order books

    OpenAIRE

    2015-01-01

    We define a stochastic model of a two-sided limit order book in terms of its key quantities \\textit{best bid [ask] price} and the \\textit{standing buy [sell] volume density}. For a simple scaling of the discreteness parameters, that keeps the expected volume rate over the considered price interval invariant, we prove a limit theorem. The limit theorem states that, given regularity conditions on the random order flow, the key quantities converge in probability to a tractable continuous limitin...

  3. An Electrochemical Detection of Metallothioneins at the Zeptomole Level in Nanolitre Volumes

    Directory of Open Access Journals (Sweden)

    Rene Kizek

    2008-04-01

    Full Text Available An Electrochemical Detection of Metallothioneins at the Zeptomole Level in Nanolitre VolumesWe report on improvement of the adsorptive transfer stripping technique (AdTS coupled with the differential pulse voltammetry Brdicka reaction to determine a thiol-protein. The current technique has been unable to generate reproducible results when analyzing very low sample volumes (nanolitres. This obstacle can be overcome technically by modifying the current transfer technique including cooling step of the adsorbed analyte. We tested the technique on determination of a promising tumour disease marker protein called metallothionein (MT. The detection limit (3 S/N of MT was evaluated as 500 zeptomoles per 500 nL (1 pM and the quantification limit (10 S/N as 1,500 zeptomoles per 500 nL (3 pM. Further, the improved AdTS technique was utilized to analyze blood serum samples from patients with breast cancer. Based on the results obtained it can be concluded that the improved technique can be used to detect a thiolprotein in very low sample volumes and can also prevent interferences during the washing and transferring step.

  4. Perennial snow and ice volumes on Iliamna Volcano, Alaska, estimated with ice radar and volume modeling

    Science.gov (United States)

    Trabant, Dennis C.

    1999-01-01

    The volume of four of the largest glaciers on Iliamna Volcano was estimated using the volume model developed for evaluating glacier volumes on Redoubt Volcano. The volume model is controlled by simulated valley cross sections that are constructed by fitting third-order polynomials to the shape of the valley walls exposed above the glacier surface. Critical cross sections were field checked by sounding with ice-penetrating radar during July 1998. The estimated volumes of perennial snow and glacier ice for Tuxedni, Lateral, Red, and Umbrella Glaciers are 8.6, 0.85, 4.7, and 0.60 cubic kilometers respectively. The estimated volume of snow and ice on the upper 1,000 meters of the volcano is about 1 cubic kilometer. The volume estimates are thought to have errors of no more than ?25 percent. The volumes estimated for the four largest glaciers are more than three times the total volume of snow and ice on Mount Rainier and about 82 times the total volume of snow and ice that was on Mount St. Helens before its May 18, 1980 eruption. Volcanoes mantled by substantial snow and ice covers have produced the largest and most catastrophic lahars and floods. Therefore, it is prudent to expect that, during an eruptive episode, flooding and lahars threaten all of the drainages heading on Iliamna Volcano. On the other hand, debris avalanches can happen any time. Fortunately, their influence is generally limited to the area within a few kilometers of the summit.

  5. Fundamental gravitational limitations to quantum computing

    CERN Document Server

    Gambini, R; Pullin, J; Gambini, Rodolfo; Porto, Rafael A.; Pullin, Jorge

    2005-01-01

    Lloyd has considered the ultimate limitations physics places on quantum computers. He concludes in particular that for an ``ultimate laptop'' (a computer of one liter of volume and one kilogram of mass) the maximum number of operations per second is bounded by $10^{51}$. The limit is derived considering ordinary quantum mechanics. Here we consider additional limits that are placed by quantum gravity ideas, namely the use of a relational notion of time and fundamental gravitational limits that exist on time measurements. We then particularize for the case of an ultimate laptop and show that the maximum number of operations is further constrained to $10^{47}$ per second.

  6. A highly addressable static droplet array enabling digital control of a single droplet at pico-volume resolution.

    Science.gov (United States)

    Jeong, Heon-Ho; Lee, Byungjin; Jin, Si Hyung; Jeong, Seong-Geun; Lee, Chang-Soo

    2016-04-26

    Droplet-based microfluidics enabling exquisite liquid-handling has been developed for diagnosis, drug discovery and quantitative biology. Compartmentalization of samples into a large number of tiny droplets is a great approach to perform multiplex assays and to improve reliability and accuracy using a limited volume of samples. Despite significant advances in microfluidic technology, individual droplet handling in pico-volume resolution is still a challenge in obtaining more efficient and varying multiplex assays. We present a highly addressable static droplet array (SDA) enabling individual digital manipulation of a single droplet using a microvalve system. In a conventional single-layer microvalve system, the number of microvalves required is dictated by the number of operation objects; thus, individual trap-and-release on a large-scale 2D array format is highly challenging. By integrating double-layer microvalves, we achieve a "balloon" valve that preserves the pressure-on state under released pressure; this valve can allow the selective releasing and trapping of 7200 multiplexed pico-droplets using only 1 μL of sample without volume loss. This selectivity and addressability completely arranged only single-cell encapsulated droplets from a mixture of droplet compositions via repetitive selective trapping and releasing. Thus, it will be useful for efficient handling of miniscule volumes of rare or clinical samples in multiplex or combinatory assays, and the selective collection of samples.

  7. Environmental Limits of Tall Shrubs in Alaska's Arctic National Parks.

    Science.gov (United States)

    Swanson, David K

    2015-01-01

    We sampled shrub canopy volume (height times area) and environmental factors (soil wetness, soil depth of thaw, soil pH, mean July air temperature, and typical date of spring snow loss) on 471 plots across five National Park Service units in northern Alaska. Our goal was to determine the environments where tall shrubs thrive and use this information to predict the location of future shrub expansion. The study area covers over 80,000 km2 and has mostly tundra vegetation. Large canopy volumes were uncommon, with volumes over 0.5 m3/m2 present on just 8% of plots. Shrub canopy volumes were highest where mean July temperatures were above 10.5°C and on weakly acid to neutral soils (pH of 6 to 7) with deep summer thaw (>80 cm) and good drainage. On many sites, flooding helped maintain favorable soil conditions for shrub growth. Canopy volumes were highest where the typical snow loss date was near 20 May; these represent sites that are neither strongly wind-scoured in the winter nor late to melt from deep snowdrifts. Individual species varied widely in the canopy volumes they attained and their response to the environmental factors. Betula sp. shrubs were the most common and quite tolerant of soil acidity, cold July temperatures, and shallow thaw depths, but they did not form high-volume canopies under these conditions. Alnus viridis formed the largest canopies and was tolerant of soil acidity down to about pH 5, but required more summer warmth (over 12°C) than the other species. The Salix species varied widely from S. pulchra, tolerant of wet and moderately acid soils, to S. alaxensis, requiring well-drained soils with near neutral pH. Nearly half of the land area in ARCN has mean July temperatures of 10.5 to 12.5°C, where 2°C of warming would bring temperatures into the range needed for all of the potential tall shrub species to form large canopies. However, limitations in the other environmental factors would probably prevent the formation of large shrub canopies

  8. Environmental Limits of Tall Shrubs in Alaska's Arctic National Parks.

    Directory of Open Access Journals (Sweden)

    David K Swanson

    Full Text Available We sampled shrub canopy volume (height times area and environmental factors (soil wetness, soil depth of thaw, soil pH, mean July air temperature, and typical date of spring snow loss on 471 plots across five National Park Service units in northern Alaska. Our goal was to determine the environments where tall shrubs thrive and use this information to predict the location of future shrub expansion. The study area covers over 80,000 km2 and has mostly tundra vegetation. Large canopy volumes were uncommon, with volumes over 0.5 m3/m2 present on just 8% of plots. Shrub canopy volumes were highest where mean July temperatures were above 10.5°C and on weakly acid to neutral soils (pH of 6 to 7 with deep summer thaw (>80 cm and good drainage. On many sites, flooding helped maintain favorable soil conditions for shrub growth. Canopy volumes were highest where the typical snow loss date was near 20 May; these represent sites that are neither strongly wind-scoured in the winter nor late to melt from deep snowdrifts. Individual species varied widely in the canopy volumes they attained and their response to the environmental factors. Betula sp. shrubs were the most common and quite tolerant of soil acidity, cold July temperatures, and shallow thaw depths, but they did not form high-volume canopies under these conditions. Alnus viridis formed the largest canopies and was tolerant of soil acidity down to about pH 5, but required more summer warmth (over 12°C than the other species. The Salix species varied widely from S. pulchra, tolerant of wet and moderately acid soils, to S. alaxensis, requiring well-drained soils with near neutral pH. Nearly half of the land area in ARCN has mean July temperatures of 10.5 to 12.5°C, where 2°C of warming would bring temperatures into the range needed for all of the potential tall shrub species to form large canopies. However, limitations in the other environmental factors would probably prevent the formation of large

  9. Statistical representative elementary volumes of porous media determined using greyscale analysis of 3D tomograms

    Science.gov (United States)

    Bruns, S.; Stipp, S. L. S.; Sørensen, H. O.

    2017-09-01

    Digital rock physics carries the dogmatic concept of having to segment volume images for quantitative analysis but segmentation rejects huge amounts of signal information. Information that is essential for the analysis of difficult and marginally resolved samples, such as materials with very small features, is lost during segmentation. In X-ray nanotomography reconstructions of Hod chalk we observed partial volume voxels with an abundance that limits segmentation based analysis. Therefore, we investigated the suitability of greyscale analysis for establishing statistical representative elementary volumes (sREV) for the important petrophysical parameters of this type of chalk, namely porosity, specific surface area and diffusive tortuosity, by using volume images without segmenting the datasets. Instead, grey level intensities were transformed to a voxel level porosity estimate using a Gaussian mixture model. A simple model assumption was made that allowed formulating a two point correlation function for surface area estimates using Bayes' theory. The same assumption enables random walk simulations in the presence of severe partial volume effects. The established sREVs illustrate that in compacted chalk, these simulations cannot be performed in binary representations without increasing the resolution of the imaging system to a point where the spatial restrictions of the represented sample volume render the precision of the measurement unacceptable. We illustrate this by analyzing the origins of variance in the quantitative analysis of volume images, i.e. resolution dependence and intersample and intrasample variance. Although we cannot make any claims on the accuracy of the approach, eliminating the segmentation step from the analysis enables comparative studies with higher precision and repeatability.

  10. Volume Regulated Channels

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjær

    - serves a multitude of functions in the mammalian cell, regulating the membrane potential (Em), cell volume, protein activity and the driving force for facilitated transporters giving Cl- and Cl- channels a major potential of regulating cellular function. These functions include control of the cell cycle...... of volume perturbations evolution have developed system of channels and transporters to tightly control volume homeostasis. In the past decades evidence has been mounting, that the importance of these volume regulated channels and transporters are not restricted to the defense of cellular volume......, controlled cell death and cellular migration. Volume regulatory mechanisms has long been in focus for regulating cellular proliferation and my thesis work have been focusing on the role of Cl- channels in proliferation with specific emphasis on ICl, swell. Pharmacological blockage of the ubiquitously...

  11. Variance optimal sampling based estimation of subset sums

    CERN Document Server

    Cohen, Edith; Kaplan, Haim; Lund, Carsten; Thorup, Mikkel

    2008-01-01

    From a high volume stream of weighted items, we want to maintain a generic sample of a certain limited size $k$ that we can later use to estimate the total weight of arbitrary subsets. This is the classic context of on-line reservoir sampling, thinking of the generic sample as a reservoir. We present a reservoir sampling scheme providing variance optimal estimation of subset sums. More precisely, if we have seen $n$ items of the stream, then for any subset size $m$, our scheme based on $k$ samples minimizes the average variance over all subsets of size $m$. In fact, the optimality is against any off-line sampling scheme tailored for the concrete set of items seen: no off-line scheme based on $k$ samples can perform better than our on-line scheme when it comes to average variance over any subset size. Our scheme has no positive covariances between any pair of item estimates. Also, our scheme can handle each new item of the stream in $O(\\log k)$ time, which is optimal even on the word RAM.

  12. Precision volume measurement system.

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Erin E.; Shugard, Andrew D.

    2004-11-01

    A new precision volume measurement system based on a Kansas City Plant (KCP) design was built to support the volume measurement needs of the Gas Transfer Systems (GTS) department at Sandia National Labs (SNL) in California. An engineering study was undertaken to verify or refute KCP's claims of 0.5% accuracy. The study assesses the accuracy and precision of the system. The system uses the ideal gas law and precise pressure measurements (of low-pressure helium) in a temperature and computer controlled environment to ratio a known volume to an unknown volume.

  13. Surfactants at the Design Limit.

    Science.gov (United States)

    Czajka, Adam; Hazell, Gavin; Eastoe, Julian

    2015-08-04

    This article analyzes how the individual structural elements of surfactant molecules affect surface properties, in particular, the point of reference defined by the limiting surface tension at the aqueous cmc, γcmc. Particular emphasis is given to how the chemical nature and structure of the hydrophobic tails influence γcmc. By comparing the three different classes of surfactants, fluorocarbon, silicone, and hydrocarbon, a generalized surface packing index is introduced which is independent of the chemical nature of the surfactants. This parameter ϕcmc represents the volume fraction of surfactant chain fragments in a surface film at the aqueous cmc. It is shown that ϕcmc is a useful index for understanding the limiting surface tension of surfactants and can be useful for designing new superefficient surfactants.

  14. HOME Income Limits

    Data.gov (United States)

    Department of Housing and Urban Development — HOME Income Limits are calculated using the same methodology that HUD uses for calculating the income limits for the Section 8 program. These limits are based on HUD...

  15. Apparatus for Sampling Surface Contamination

    Science.gov (United States)

    Wells, Mark

    2008-01-01

    An apparatus denoted a swab device has been developed as a convenient means of acquiring samples of contaminants from surfaces and suspending the samples in liquids. (Thereafter, the liquids can be dispensed, in controlled volumes, into scientific instruments for analysis of the contaminants.) The swab device is designed so as not to introduce additional contamination and to facilitate, simplify, and systematize the dispensing of controlled volumes of liquid into analytical instruments. The swab device is a single apparatus into which are combined all the equipment and materials needed for sampling surface contamination. The swab device contains disposable components stacked together on a nondisposable dispensing head. One of the disposable components is a supply cartridge holding a sufficient volume of liquid for one complete set of samples. (The liquid could be clean water or another suitable solvent, depending on the application.) This supply of liquid is sealed by Luer valves. At the beginning of a sampling process, the user tears open a sealed bag containing the supply cartridge. A tip on the nondisposable dispensing head is engaged with a Luer valve on one end of the supply cartridge and rotated, locking the supply cartridge on the dispensing head and opening the valve. The swab tip includes a fabric swab that is wiped across the surface of interest to acquire a sample. A sealed bag containing a disposable dispensing tip is then opened, and the swab tip is pushed into the dispensing tip until seated. The dispensing head contains a piston that passes through a spring-loaded lip seal. The air volume displaced by this piston forces the liquid out of the supply cartridge, over the swab, and into the dispensing tip. The piston is manually cycled to enforce oscillation of the air volume and thereby to cause water to flow to wash contaminants from the swab and cause the resulting liquid suspension of contaminants to flow into the dispensing tip. After several cycles

  16. 基于准同雨团样本概念雷达和雨量计的实时同步结合方法%Real time synchronously integrated technique for radar and raingauge based on concept of quasi-same rain volume sample.

    Institute of Scientific and Technical Information of China (English)

    万玉发; 吴翠红; 金鸿祥

    2008-01-01

    The real time synchronously integrated technique for radar and raingauge (R&G) based on the concept of quasi-same rain volume sample was presented. Because of the presence of temporal and spatial discrepancies as well as resolution differences, the same sample correspondence of R&G has long been a difficult, lasting problem. However, the observations indicate that there exists the correlation conforming to the power-law between hourly accumulation of raingauge measurement QG and radar detected echo aloft over the rain gauge vertically (ZOH). On the basis of this fact, aiming to eliminate the temporal and spatial discrepancies, the concept of quasi-same rain volume sample and the five direct correspondence relationships of R&G are built up. The quite convenient and practical TIVS, i.e. time integral vertical synchronous sampling, and its ZOH-QG relationship with power law are emphatically studied. What has significance is that under the fixed exponent, the coefficient AB or AM can flexibly vary in accordance with the temporal and spatial variability of the natural precipitation, and has a function to synchronously integrate the Z-R conversion and the gauge adjustment into a single equation, thus the precipitation estimation error caused by detecting resolution differences between radar and gauge can be obviously mitigated. It is apparently different from the traditional methods wherein precipitation is estimated by radar and gauge, respectively. The real time synchronously integrated technique using the ZOH-QG relationship to estimate hourly ground rainfall accumulation, is called radar-gauge synchronously integrated method (RASIM). The experiments of two cases show that the correctness rate for area estimation within 230 km is about 90% and the average relative error rate for point estimation over the whole process is about 20%.Through the analysis of effects for various wind drifts in three kinds of environment fields, the physical substance of TIVS has been

  17. Variable volume combustor

    Energy Technology Data Exchange (ETDEWEB)

    Ostebee, Heath Michael; Ziminsky, Willy Steve; Johnson, Thomas Edward; Keener, Christopher Paul

    2017-01-17

    The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a linear actuator so as to maneuver the micro-mixer fuel nozzles axially along the liner.

  18. Volume Regulated Channels

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjær

    of volume perturbations evolution have developed system of channels and transporters to tightly control volume homeostasis. In the past decades evidence has been mounting, that the importance of these volume regulated channels and transporters are not restricted to the defense of cellular volume...... but are also essential for a number of physiological processes such as proliferation, controlled cell death, migration and endocrinology. The thesis have been focusing on two Channels, namely the swelling activated Cl- channel (ICl, swell) and the transient receptor potential Vanilloid (TRPV4) channel. I: Cl......- serves a multitude of functions in the mammalian cell, regulating the membrane potential (Em), cell volume, protein activity and the driving force for facilitated transporters giving Cl- and Cl- channels a major potential of regulating cellular function. These functions include control of the cell cycle...

  19. Spitzer Local Volume Legacy (LVL) SEDs and Physical Properties

    CERN Document Server

    Cook, David O; Johnson, Benjamin D; Van Zee, Liese; Lee, Janice C; Kennicutt, Robert C; Calzetti, Daniela; Staudaher, Shawn M; Engelbracht, Charles W

    2014-01-01

    We present the panchromatic spectral energy distributions (SEDs) of the Local Volume Legacy (LVL) survey which consists of 258 nearby galaxies ($D<$11 Mpc). The wavelength coverage spans the ultraviolet to the infrared (1500 $\\textrm{\\AA}$ to 24 $\\mu$m) which is utilized to derive global physical properties (i.e., star formation rate, stellar mass, internal extinction due to dust.). With these data, we find color-color relationships and correlated trends between observed and physical properties (i.e., optical magnitudes and dust properties, optical color and specific star formation rate, and ultraviolet-infrared color and metallicity). The SEDs are binned by different galaxy properties to reveal how each property affects the observed shape of these SEDs. In addition, due to the volume-limited nature of LVL, we utilize the dwarf-dominated galaxy sample to test star formation relationships established with higher-mass galaxy samples. We find good agreement with the star-forming "main-sequence" relationship, ...

  20. Perpendicular distance sampling: an alternative method for sampling downed coarse woody debris

    Science.gov (United States)

    Michael S. Williams; Jeffrey H. Gove

    2003-01-01

    Coarse woody debris (CWD) plays an important role in many forest ecosystem processes. In recent years, a number of new methods have been proposed to sample CWD. These methods select individual logs into the sample using some form of unequal probability sampling. One concern with most of these methods is the difficulty in estimating the volume of each log. A new method...