WorldWideScience

Sample records for accurately measuring recombination

  1. Assignment of resonances in dissociative recombination of HD{sup +} ions: High-resolution measurements compared with accurate computations

    Energy Technology Data Exchange (ETDEWEB)

    Waffeu Tamo, F. O. [Laboratoire Ondes et Milieux Complexes FRE-3102 CNRS and Universite du Havre, 25, rue Philippe Lebon, BP 540, F-76058 Le Havre (France); Centre for Atomic, Molecular Physics and Quantum Optics (CEPAMOQ), University of Douala, P.O. Box 8580, Douala (Cameroon); Laboratoire d' Etude du Rayonnement et de la Matiere en Astrophysique, Observatoire de Paris, F-91295 Meudon Cedex (France); Buhr, H.; Schwalm, D. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Department of Particle Physics, Weizmann Institute of Science, P.O. Box 26, 76100 Rehovot (Israel); Motapon, O. [LPF, UFD Physique et Sciences de l' Ingenieur, University of Douala, P.O. Box 24157, Douala (Cameroon); Altevogt, S.; Andrianarijaona, V. M.; Grieser, M.; Lammich, L.; Lestinsky, M.; Motsch, M.; Novotny, S.; Orlov, D. A.; Pedersen, H. B.; Sprenger, F.; Weigel, U.; Wolf, A. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Nevo, I. [Department of Particle Physics, Weizmann Institute of Science, P.O. Box 26, 76100 Rehovot (Israel); Urbain, X. [Institute of Condensed Matter and Nanosciences, Universite catholique de Louvain, chemin du cyclotron 2, B-1348 Louvain-la Neuve (Belgium); Schneider, I. F. [Laboratoire Ondes et Milieux Complexes FRE-3102 CNRS and Universite du Havre, 25, rue Philippe Lebon, BP 540, F-76058 Le Havre (France)

    2011-08-15

    The collision-energy resolved rate coefficient for dissociative recombination of HD{sup +} ions in the vibrational ground state is measured using the photocathode electron target at the heavy-ion storage ring TSR. Rydberg resonances associated with rovibrational excitation of the HD{sup +} core are scanned as a function of the electron collision energy with an instrumental broadening below 1 meV in the low-energy limit. The measurement is compared to calculations using multichannel quantum defect theory, accounting for rotational structure and interactions and considering the six lowest rotational energy levels as initial ionic states. Using thermal-equilibrium-level populations at 300 K to approximate the experimental conditions, close correspondence between calculated and measured structures is found up to the first vibrational excitation threshold of the cations near 0.24 eV. Detailed assignments, including naturally broadened and overlapping Rydberg resonances, are performed for all structures up to 0.024 eV. Resonances from purely rotational excitation of the ion core are found to have similar strengths as those involving vibrational excitation. A dominant low-energy resonance is assigned to contributions from excited rotational states only. The results indicate strong modifications in the energy dependence of the dissociative recombination rate coefficient through the rotational excitation of the parent ions, and underline the need for studies with rotationally cold species to obtain results reflecting low-temperature ionized media.

  2. Assignment of resonances in dissociative recombination of HD+ ions: high-resolution measurements compared with accurate computations

    CERN Document Server

    Tamo, F O Waffeu; Motapon, O; Altevogt, S; Andrianarijaona, V M; Grieser, M; Lammich, L; Lestinsky, M; Motsch, M; Nevo, I; Novotny, S; Orlov, D A; Pedersen, H B; Schwalm, D; Sprenger, F; Urbain, X; Weigel, U; Wolf, A; Schneider, I F

    2011-01-01

    The collision-energy resolved rate coefficient for dissociative recombination of HD+ ions in the vibrational ground state is measured using the photocathode electron target at the heavy-ion storage ring TSR. Rydberg resonances associated with ro-vibrational excitation of the HD+ core are scanned as a function of the electron collision energy with an instrumental broadening below 1 meV in the low-energy limit. The measurement is compared to calculations using multichannel quantum defect theory, accounting for rotational structure and interactions and considering the six lowest rotational energy levels as initial ionic states. Using thermal equilibrium level populations at 300 K to approximate the experimental conditions, close correspondence between calculated and measured structures is found up to the first vibrational excitation threshold of the cations near 0.24 eV. Detailed assignments, including naturally broadened and overlapping Rydberg resonances, are performed for all structures up to 0.024 eV. Resona...

  3. Accurate Measurement of the

    NARCIS (Netherlands)

    Cueto Rojas, H.F.; Maleki Seifar, R.; ten Pierick, A.; Heijnen, J.J.; Wahl, S.A.

    2016-01-01

    Ammonium (NH4+) is the most common N-source for yeast fermentations, and N-limitation is frequently applied to reduce growth and increase product yields. While there is significant molecular knowledge on NH4 + transport and assimilation, there have been few attempts to measure the in vivo

  4. Accurate measurements in volume data

    NARCIS (Netherlands)

    Oliván Bescós, J.; Bosma, Marco; Smit, Jaap; Mun, S.K.

    2001-01-01

    An algorithm for very accurate visualization of an iso- surface in a 3D medical dataset has been developed in the past few years. This technique is extended in this paper to several kinds of measurements in which exact geometric information of a selected iso-surface is used to derive volume, length,

  5. 38 CFR 4.46 - Accurate measurement.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect to...

  6. Invariant Measures of Genetic Recombination Processes

    Science.gov (United States)

    Akopyan, Arseniy V.; Pirogov, Sergey A.; Rybko, Aleksandr N.

    2015-07-01

    We construct a non-linear Markov process connected with a biological model of a bacterial genome recombination. The description of invariant measures of this process gives us the solution of one problem in elementary probability theory.

  7. Accurate measurement of unsteady state fluid temperature

    Science.gov (United States)

    Jaremkiewicz, Magdalena

    2017-03-01

    In this paper, two accurate methods for determining the transient fluid temperature were presented. Measurements were conducted for boiling water since its temperature is known. At the beginning the thermometers are at the ambient temperature and next they are immediately immersed into saturated water. The measurements were carried out with two thermometers of different construction but with the same housing outer diameter equal to 15 mm. One of them is a K-type industrial thermometer widely available commercially. The temperature indicated by the thermometer was corrected considering the thermometers as the first or second order inertia devices. The new design of a thermometer was proposed and also used to measure the temperature of boiling water. Its characteristic feature is a cylinder-shaped housing with the sheath thermocouple located in its center. The temperature of the fluid was determined based on measurements taken in the axis of the solid cylindrical element (housing) using the inverse space marching method. Measurements of the transient temperature of the air flowing through the wind tunnel using the same thermometers were also carried out. The proposed measurement technique provides more accurate results compared with measurements using industrial thermometers in conjunction with simple temperature correction using the inertial thermometer model of the first or second order. By comparing the results, it was demonstrated that the new thermometer allows obtaining the fluid temperature much faster and with higher accuracy in comparison to the industrial thermometer. Accurate measurements of the fast changing fluid temperature are possible due to the low inertia thermometer and fast space marching method applied for solving the inverse heat conduction problem.

  8. More accurate recombination prediction in HIV-1 using a robust decoding algorithm for HMMs

    Directory of Open Access Journals (Sweden)

    Brown Daniel G

    2011-05-01

    Full Text Available Abstract Background Identifying recombinations in HIV is important for studying the epidemiology of the virus and aids in the design of potential vaccines and treatments. The previous widely-used tool for this task uses the Viterbi algorithm in a hidden Markov model to model recombinant sequences. Results We apply a new decoding algorithm for this HMM that improves prediction accuracy. Exactly locating breakpoints is usually impossible, since different subtypes are highly conserved in some sequence regions. Our algorithm identifies these sites up to a certain error tolerance. Our new algorithm is more accurate in predicting the location of recombination breakpoints. Our implementation of the algorithm is available at http://www.cs.uwaterloo.ca/~jmtruszk/jphmm_balls.tar.gz. Conclusions By explicitly accounting for uncertainty in breakpoint positions, our algorithm offers more reliable predictions of recombination breakpoints in HIV-1. We also document a new domain of use for our new decoding approach in HMMs.

  9. Apparatus for accurately measuring high temperatures

    Science.gov (United States)

    Smith, D.D.

    The present invention is a thermometer used for measuring furnace temperatures in the range of about 1800/sup 0/ to 2700/sup 0/C. The thermometer comprises a broadband multicolor thermal radiation sensor positioned to be in optical alignment with the end of a blackbody sight tube extending into the furnace. A valve-shutter arrangement is positioned between the radiation sensor and the sight tube and a chamber for containing a charge of high pressure gas is positioned between the valve-shutter arrangement and the radiation sensor. A momentary opening of the valve shutter arrangement allows a pulse of the high gas to purge the sight tube of air-borne thermal radiation contaminants which permits the radiation sensor to accurately measure the thermal radiation emanating from the end of the sight tube.

  10. Fast and accurate exhaled breath ammonia measurement.

    Science.gov (United States)

    Solga, Steven F; Mudalel, Matthew L; Spacek, Lisa A; Risby, Terence H

    2014-06-11

    This exhaled breath ammonia method uses a fast and highly sensitive spectroscopic method known as quartz enhanced photoacoustic spectroscopy (QEPAS) that uses a quantum cascade based laser. The monitor is coupled to a sampler that measures mouth pressure and carbon dioxide. The system is temperature controlled and specifically designed to address the reactivity of this compound. The sampler provides immediate feedback to the subject and the technician on the quality of the breath effort. Together with the quick response time of the monitor, this system is capable of accurately measuring exhaled breath ammonia representative of deep lung systemic levels. Because the system is easy to use and produces real time results, it has enabled experiments to identify factors that influence measurements. For example, mouth rinse and oral pH reproducibly and significantly affect results and therefore must be controlled. Temperature and mode of breathing are other examples. As our understanding of these factors evolves, error is reduced, and clinical studies become more meaningful. This system is very reliable and individual measurements are inexpensive. The sampler is relatively inexpensive and quite portable, but the monitor is neither. This limits options for some clinical studies and provides rational for future innovations.

  11. A standardized framework for accurate, high-throughput genotyping of recombinant and non-recombinant viral sequences.

    Science.gov (United States)

    Alcantara, Luiz Carlos Junior; Cassol, Sharon; Libin, Pieter; Deforche, Koen; Pybus, Oliver G; Van Ranst, Marc; Galvão-Castro, Bernardo; Vandamme, Anne-Mieke; de Oliveira, Tulio

    2009-07-01

    Human immunodeficiency virus type-1 (HIV-1), hepatitis B and C and other rapidly evolving viruses are characterized by extremely high levels of genetic diversity. To facilitate diagnosis and the development of prevention and treatment strategies that efficiently target the diversity of these viruses, and other pathogens such as human T-lymphotropic virus type-1 (HTLV-1), human herpes virus type-8 (HHV8) and human papillomavirus (HPV), we developed a rapid high-throughput-genotyping system. The method involves the alignment of a query sequence with a carefully selected set of pre-defined reference strains, followed by phylogenetic analysis of multiple overlapping segments of the alignment using a sliding window. Each segment of the query sequence is assigned the genotype and sub-genotype of the reference strain with the highest bootstrap (>70%) and bootscanning (>90%) scores. Results from all windows are combined and displayed graphically using color-coded genotypes. The new Virus-Genotyping Tools provide accurate classification of recombinant and non-recombinant viruses and are currently being assessed for their diagnostic utility. They have incorporated into several HIV drug resistance algorithms including the Stanford (http://hivdb.stanford.edu) and two European databases (http://www.umcutrecht.nl/subsite/spread-programme/ and http://www.hivrdb.org.uk/) and have been successfully used to genotype a large number of sequences in these and other databases. The tools are a PHP/JAVA web application and are freely accessible on a number of servers including: http://bioafrica.mrc.ac.za/rega-genotype/html/, http://lasp.cpqgm.fiocruz.br/virus-genotype/html/, http://jose.med.kuleuven.be/genotypetool/html/.

  12. Designing an accurate system for temperature measurements

    Directory of Open Access Journals (Sweden)

    Kochan Orest

    2017-01-01

    Full Text Available The method of compensation of changes in temperature field along the legs of inhomogeneous thermocouple, which measures a temperature of an object, is considered in this paper. This compensation is achieved by stabilization of the temperature field along the thermocouple. Such stabilization does not allow the error due to acquired thermoelectric inhomogeneity to manifest itself. There is also proposed the design of the furnace to stabilize temperature field along the legs of the thermocouple which measures the temperature of an object. This furnace is not integrated with the thermocouple mentioned above, therefore it is possible to replace this thermocouple with a new one when it get its legs considerably inhomogeneous.. There is designed the two loop measuring system with the ability of error correction which can use simultaneously a usual thermocouple as well as a thermocouple with controlled profile of temperature field. The latter can be used as a reference sensor for the former.

  13. Accurate test limits under nonnormal measurement error

    NARCIS (Netherlands)

    Albers, Willem/Wim; Kallenberg, W.C.M.; Otten, G.D.

    1998-01-01

    When screening a production process for nonconforming items the objective is to improve the average outgoing quality level. Due to measurement errors specification limits cannot be checked directly and hence test limits are required, which meet some given requirement, here given by a prescribed

  14. Accurate Black Hole Spin Measurements using ABC

    Science.gov (United States)

    Connolly, Andrew

    Measuring the spin of black holes provides important insights into the supernova formation mechanism of stellar-mass black holes, galaxy merger scenarios for supermassive black holes, and the launching mechanisms of ballistic jets. It is therefore of crucial importance to measure black hole spins to a high degree of accuracy. Stellar-mass black holes in binary systems (BHBs) have two major advantages over Active Galactic Nuclei (AGN): (1) owing to their proximity and brightness, observations of BHBs are not as limited by counting statistics as their supermassive counter-parts; (2) unlike in AGN, one can use two largely independent methods to measure the spin in BHBs, providing a check on spin measurements. However, the high flux that makes BHBs such excellent targets for spin measurements also proves to be their Achilles heel: modern CCD cameras are optimized for observing faint sources. Consequently, observations of bright BHBs with CCD cameras are subject to non-linear instrumental effects among them pile-up and grade migration that strongly distort the spectrum. Since spin measurements rely on a very precise model of both the continuum X-ray flux and disc reflection signatures superimposed on top of the former, these instrumental effects may cause inferred spin measurements to differ by a factor of two or more. Current mitigation strategies are aimed at removing instrumental effects either during the observations themselves, by requiring simultaneous observations with multiple telescopes, or in post-processing. Even when these techniques are employed, pile-up may remain unrecognized and still distort results, whereas mitigation strategies may introduce additional systematic biases, e.g. due to increased (cross-)calibration uncertainties. Advances in modern statistical methodology allow for efficient modeling of instrumental effects during the analysis stage, largely eliminating the requirements for observations with multiple instruments or increased observation

  15. Accurate phase measurement with classical light

    OpenAIRE

    Wölk, Sabine; Ge, Wenchao; Zubairy, M. Suhail

    2012-01-01

    In this paper we investigate whether it is in general possible to substitute maximally path-entangled states, namely NOON-states by classical light in a Doppleron-type resonant multiphoton detection processes by studying adaptive phase measurement with classical light. We show that multiphoton detection probability using classical light coincides with that of NOON-states and the multiphoton absorbtion rate is not hindered by the spatially unconstrained photons of the classical light in our sc...

  16. A Simple and Accurate Method for Measuring Enzyme Activity.

    Science.gov (United States)

    Yip, Din-Yan

    1997-01-01

    Presents methods commonly used for investigating enzyme activity using catalase and presents a new method for measuring catalase activity that is more reliable and accurate. Provides results that are readily reproduced and quantified. Can also be used for investigations of enzyme properties such as the effects of temperature, pH, inhibitors,…

  17. Toward more accurate loss tangent measurements in reentrant cavities

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, R. D.

    1980-05-01

    Karpova has described an absolute method for measurement of dielectric properties of a solid in a coaxial reentrant cavity. His cavity resonance equation yields very accurate results for dielectric constants. However, he presented only approximate expressions for the loss tangent. This report presents more exact expressions for that quantity and summarizes some experimental results.

  18. Accurate measurement of streamwise vortices using dual-plane PIV

    Science.gov (United States)

    Waldman, Rye M.; Breuer, Kenneth S.

    2012-11-01

    Low Reynolds number aerodynamic experiments with flapping animals (such as bats and small birds) are of particular interest due to their application to micro air vehicles which operate in a similar parameter space. Previous PIV wake measurements described the structures left by bats and birds and provided insight into the time history of their aerodynamic force generation; however, these studies have faced difficulty drawing quantitative conclusions based on said measurements. The highly three-dimensional and unsteady nature of the flows associated with flapping flight are major challenges for accurate measurements. The challenge of animal flight measurements is finding small flow features in a large field of view at high speed with limited laser energy and camera resolution. Cross-stream measurement is further complicated by the predominately out-of-plane flow that requires thick laser sheets and short inter-frame times, which increase noise and measurement uncertainty. Choosing appropriate experimental parameters requires compromise between the spatial and temporal resolution and the dynamic range of the measurement. To explore these challenges, we do a case study on the wake of a fixed wing. The fixed model simplifies the experiment and allows direct measurements of the aerodynamic forces via load cell. We present a detailed analysis of the wake measurements, discuss the criteria for making accurate measurements, and present a solution for making quantitative aerodynamic load measurements behind free-flyers.

  19. Measurement of recombination in MicroBooNE

    Science.gov (United States)

    Luo, Xiao; Balasubramanian, Supraja; Yang, Tingjun; MicroBooNE Collaboration

    2017-01-01

    MicroBooNE uses the Liquid Argon Time Projection Chamber (LAr TPC) technology to detect neutrino interactions from the Fermilab Booster Neutrino Beam. Traveling through the detector volume, charged particles deposit energy by ionizing the argon and create positive argon ions and electron pairs along their trajectory. The electrons can recombine with an argon ion and reform a neutral atom and, as a result, the measured energy is only a fraction of the total energy lost by the particle. This process is called electron-ion recombination. Understanding this recombination effect is particularly important for performing calorimetry, identifying particle types, and achieving good energy resolution in LAr TPCs. This talk will present the status of MicroBooNE's first recombination measurement obtained with cosmic ray data.

  20. Calibration Techniques for Accurate Measurements by Underwater Camera Systems

    Science.gov (United States)

    Shortis, Mark

    2015-01-01

    Calibration of a camera system is essential to ensure that image measurements result in accurate estimates of locations and dimensions within the object space. In the underwater environment, the calibration must implicitly or explicitly model and compensate for the refractive effects of waterproof housings and the water medium. This paper reviews the different approaches to the calibration of underwater camera systems in theoretical and practical terms. The accuracy, reliability, validation and stability of underwater camera system calibration are also discussed. Samples of results from published reports are provided to demonstrate the range of possible accuracies for the measurements produced by underwater camera systems. PMID:26690172

  1. A method for accurate temperature measurement using infrared thermal camera.

    Science.gov (United States)

    Tokunaga, Tomoharu; Narushima, Takashi; Yonezawa, Tetsu; Sudo, Takayuki; Okubo, Shuichi; Komatsubara, Shigeyuki; Sasaki, Katsuhiro; Yamamoto, Takahisa

    2012-08-01

    The temperature distribution on a centre-holed thin foil of molybdenum, used as a sample and heated using a sample-heating holder for electron microscopy, was measured using an infrared thermal camera. The temperature on the heated foil area located near the heating stage of the heating holder is almost equal to the temperature on the heating stage. However, during the measurement of the temperature at the edge of the hole of the foil located farthest from the heating stage, a drop in temperature should be taken into consideration; however, so far, no method has been developed to locally measure the temperature distribution on the heated sample. In this study, a method for the accurate measurement of temperature distribution on heated samples for electron microscopy is discussed.

  2. Precise and accurate isotopic measurements using multiple-collector ICPMS

    Science.gov (United States)

    Albarède, F.; Telouk, Philippe; Blichert-Toft, Janne; Boyet, Maud; Agranier, Arnaud; Nelson, Bruce

    2004-06-01

    New techniques of isotopic measurements by a new generation of mass spectrometers equipped with an inductively-coupled-plasma source, a magnetic mass filter, and multiple collection (MC-ICPMS) are quickly developing. These techniques are valuable because of (1) the ability of ICP sources to ionize virtually every element in the periodic table, and (2) the large sample throughout. However, because of the complex trajectories of multiple ion beams produced in the plasma source whether from the same or different elements, the acquisition of precise and accurate isotopic data with this type of instrument still requires a good understanding of instrumental fractionation processes, both mass-dependent and mass-independent. Although physical processes responsible for the instrumental mass bias are still to be understood more fully, we here present a theoretical framework that allows for most of the analytical limitations to high precision and accuracy to be overcome. After a presentation of unifying phenomenological theory for mass-dependent fractionation in mass spectrometers, we show how this theory accounts for the techniques of standard bracketing and of isotopic normalization by a ratio of either the same or a different element, such as the use of Tl to correct mass bias on Pb. Accuracy is discussed with reference to the concept of cup efficiencies. Although these can be simply calibrated by analyzing standards, we derive a straightforward, very general method to calculate accurate isotopic ratios from dynamic measurements. In this study, we successfully applied the dynamic method to Nd and Pb as examples. We confirm that the assumption of identical mass bias for neighboring elements (notably Pb and Tl, and Yb and Lu) is both unnecessary and incorrect. We further discuss the dangers of straightforward standard-sample bracketing when chemical purification of the element to be analyzed is imperfect. Pooling runs to improve precision is acceptable provided the pooled

  3. Accurate measurement method for tube's endpoints based on machine vision

    Science.gov (United States)

    Liu, Shaoli; Jin, Peng; Liu, Jianhua; Wang, Xiao; Sun, Peng

    2017-01-01

    Tubes are used widely in aerospace vehicles, and their accurate assembly can directly affect the assembling reliability and the quality of products. It is important to measure the processed tube's endpoints and then fix any geometric errors correspondingly. However, the traditional tube inspection method is time-consuming and complex operations. Therefore, a new measurement method for a tube's endpoints based on machine vision is proposed. First, reflected light on tube's surface can be removed by using photometric linearization. Then, based on the optimization model for the tube's endpoint measurements and the principle of stereo matching, the global coordinates and the relative distance of the tube's endpoint are obtained. To confirm the feasibility, 11 tubes are processed to remove the reflected light and then the endpoint's positions of tubes are measured. The experiment results show that the measurement repeatability accuracy is 0.167 mm, and the absolute accuracy is 0.328 mm. The measurement takes less than 1 min. The proposed method based on machine vision can measure the tube's endpoints without any surface treatment or any tools and can realize on line measurement.

  4. Accurate assessment of exposure using tracer gas measurements

    DEFF Research Database (Denmark)

    Kierat, Wojciech; Bivolarova, Mariya; Zavrl, Eva

    2018-01-01

    Room airflow interaction, particularly in the breathing zone, is important to assess exposure to indoor air pollution. A breathing thermal manikin was used to simulate a room occupant with the convective boundary layer (CBL) generated around the body and the respiratory flow. Local airflow against...... the face of the manikin was applied to increase the complexity of the airflow interaction. CO2 was released at the armpits and N2O at the groin to simulate the respective bio-effluents generated at these two body sites. The tracer gas concentration at the mouth/nose of the manikin was measured with gas...... with a decrease in the response time of the gas analyzer. When only CBL was present, shorter measurement time was needed for the accurate concentration measurement of the tracer gas released close to the breathing zone. For more complex flow, as a result of CBL interaction with the exhalation flow, the needed...

  5. Accurate mass measurements on neutron-deficient krypton isotopes

    CERN Document Server

    Rodríguez, D.; Äystö, J.; Beck, D.; Blaum, K.; Bollen, G.; Herfurth, F.; Jokinen, A.; Kellerbauer, A.; Kluge, H.-J.; Kolhinen, V.S.; Oinonen, M.; Sauvan, E.; Schwarz, S.

    2006-01-01

    The masses of $^{72–78,80,82,86}$Kr were measured directly with the ISOLTRAP Penning trap mass spectrometer at ISOLDE/CERN. For all these nuclides, the measurements yielded mass uncertainties below 10 keV. The ISOLTRAP mass values for $^{72–75}$Kr being more precise than the previous results obtained by means of other techniques, and thus completely determine the new values in the Atomic-Mass Evaluation. Besides the interest of these masses for nuclear astrophysics, nuclear structure studies, and Standard Model tests, these results constitute a valuable and accurate input to improve mass models. In this paper, we present the mass measurements and discuss the mass evaluation for these Kr isotopes.

  6. Technological Basis and Scientific Returns for Absolutely Accurate Measurements

    Science.gov (United States)

    Dykema, J. A.; Anderson, J.

    2011-12-01

    The 2006 NRC Decadal Survey fostered a new appreciation for societal objectives as a driving motivation for Earth science. Many high-priority societal objectives are dependent on predictions of weather and climate. These predictions are based on numerical models, which derive from approximate representations of well-founded physics and chemistry on space and timescales appropriate to global and regional prediction. These laws of chemistry and physics in turn have a well-defined quantitative relationship with physical measurement units, provided these measurement units are linked to international measurement standards that are the foundation of contemporary measurement science and standards for engineering and commerce. Without this linkage, measurements have an ambiguous relationship to scientific principles that introduces avoidable uncertainty in analyses, predictions, and improved understanding of the Earth system. Since the improvement of climate and weather prediction is fundamentally dependent on the improvement of the representation of physical processes, measurement systems that reduce the ambiguity between physical truth and observations represent an essential component of a national strategy for understanding and living with the Earth system. This paper examines the technological basis and potential science returns of sensors that make measurements that are quantitatively tied on-orbit to international measurement standards, and thus testable to systematic errors. This measurement strategy provides several distinct benefits. First, because of the quantitative relationship between these international measurement standards and fundamental physical constants, measurements of this type accurately capture the true physical and chemical behavior of the climate system and are not subject to adjustment due to excluded measurement physics or instrumental artifacts. In addition, such measurements can be reproduced by scientists anywhere in the world, at any time

  7. Dielectronic recombination measurements at EBIT (Electron Beam Ion Trap)

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, D.A.

    1990-10-04

    The Electron Beam Ion Trap at the Lawrence Livermore National Laboratory has proved an ideal device for the study of interactions between electrons and highly-charged ions. I describe measurements of one such interaction, dielectronic recombination, in several ion species. The results are in marginal agreement with theoretical predictions. 8 refs., 6 figs.

  8. Atomic recombination rate determination through heat-transfer measurement.

    Science.gov (United States)

    Park, C.; Anderson, L. A.; Sheldahl, R. E.

    1973-01-01

    A theoretical and experimental demonstration is presented which shows that under suitable conditions the volume recombination coefficient can be determined by measuring the heat transfer rate into the wall of a cylinder through which a dissociated stream is passing. The experimental results obtained are in agreement with those of other investigators.

  9. Measurement and Accurate Interpretation of the Solubility of Pharmaceutical Salts.

    Science.gov (United States)

    He, Yan; Ho, Chris; Yang, Donglai; Chen, Jeane; Orton, Edward

    2017-05-01

    Salt formation is one of the primary approaches to improve the developability of ionizable poorly water-soluble compounds. Solubility determination of the salt candidates in aqueous media or biorelevant fluids is a critical step in salt screening. Salt solubility measurements can be complicated due to dynamic changes in both solution and solid phases. Because of the early implementation of salt screening in research, solubility measurements often are performed using minimal amount of material. Some salts have transient high solubility on dissolution. Recognition of these transients can be critical in developing these salts into drug products. This minireview focuses on challenges in salt solubility measurements due to the changes in solution caused by self-buffering effects of dissolved species and the changes in solid phase due to solid-state phase transformations. Solubility measurements and their accurate interpretation are assessed in the context of dissolution monitoring and solid-phase analysis technologies. A harmonized method for reporting salt solubility measurements is recommended to reduce errors and to align with the U.S. Pharmacopeial policy and Food and Drug Administration recommendations for drug products containing pharmaceutical salts. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  10. Accurate fluid force measurement based on control surface integration

    Science.gov (United States)

    Lentink, David

    2018-01-01

    Nonintrusive 3D fluid force measurements are still challenging to conduct accurately for freely moving animals, vehicles, and deforming objects. Two techniques, 3D particle image velocimetry (PIV) and a new technique, the aerodynamic force platform (AFP), address this. Both rely on the control volume integral for momentum; whereas PIV requires numerical integration of flow fields, the AFP performs the integration mechanically based on rigid walls that form the control surface. The accuracy of both PIV and AFP measurements based on the control surface integration is thought to hinge on determining the unsteady body force associated with the acceleration of the volume of displaced fluid. Here, I introduce a set of non-dimensional error ratios to show which fluid and body parameters make the error negligible. The unsteady body force is insignificant in all conditions where the average density of the body is much greater than the density of the fluid, e.g., in gas. Whenever a strongly deforming body experiences significant buoyancy and acceleration, the error is significant. Remarkably, this error can be entirely corrected for with an exact factor provided that the body has a sufficiently homogenous density or acceleration distribution, which is common in liquids. The correction factor for omitting the unsteady body force, {{{ {ρ f}} {1 - {ρ f} ( {{ρ b}+{ρ f}} )}.{( {{{{ρ }}b}+{ρ f}} )}}} , depends only on the fluid, {ρ f}, and body, {{ρ }}b, density. Whereas these straightforward solutions work even at the liquid-gas interface in a significant number of cases, they do not work for generalized bodies undergoing buoyancy in combination with appreciable body density inhomogeneity, volume change (PIV), or volume rate-of-change (PIV and AFP). In these less common cases, the 3D body shape needs to be measured and resolved in time and space to estimate the unsteady body force. The analysis shows that accounting for the unsteady body force is straightforward to non

  11. Accurate mass measurements of very short-lived nuclei

    CERN Document Server

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

    2002-01-01

    Mass measurements of /sup 34/Ar, /sup 73-78/Kr, and /sup 74,76/Rb were performed with the Penning-trap mass spectrometer ISOLTRAP. Very accurate Q/sub EC/-values are needed for the investigations of the F /sub t/-value of 0/sup +/ to 0/sup +/ nuclear beta -decays used to test the standard model predictions for weak interactions. The necessary accuracy on the Q/sub EC/-value requires the mass of mother and daughter nuclei to be measured with delta m/mmeasured nuclides presented here this has been reached. The /sup 34/Ar mass has been measured with a relative accuracy of 1.1.10/sup -8/. The Q/sub EC/-value of the /sup 34/Ar 0 /sup +/ to 0/sup +/ decay can now he determined with an uncertainty of about 0.01%. Furthermore, /sup 74/Rb is the shortest-lived nuclide ever investigated in a Penning trap. (18 refs).

  12. Accurate measurement of streamwise vortices in low speed aerodynamic flows

    Science.gov (United States)

    Waldman, Rye M.; Kudo, Jun; Breuer, Kenneth S.

    2010-11-01

    Low Reynolds number experiments with flapping animals (such as bats and small birds) are of current interest in understanding biological flight mechanics, and due to their application to Micro Air Vehicles (MAVs) which operate in a similar parameter space. Previous PIV wake measurements have described the structures left by bats and birds, and provided insight to the time history of their aerodynamic force generation; however, these studies have faced difficulty drawing quantitative conclusions due to significant experimental challenges associated with the highly three-dimensional and unsteady nature of the flows, and the low wake velocities associated with lifting bodies that only weigh a few grams. This requires the high-speed resolution of small flow features in a large field of view using limited laser energy and finite camera resolution. Cross-stream measurements are further complicated by the high out-of-plane flow which requires thick laser sheets and short interframe times. To quantify and address these challenges we present data from a model study on the wake behind a fixed wing at conditions comparable to those found in biological flight. We present a detailed analysis of the PIV wake measurements, discuss the criteria necessary for accurate measurements, and present a new dual-plane PIV configuration to resolve these issues.

  13. Study of accurate volume measurement system for plutonium nitrate solution

    Energy Technology Data Exchange (ETDEWEB)

    Hosoma, T. [Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Tokai Works

    1998-12-01

    It is important for effective safeguarding of nuclear materials to establish a technique for accurate volume measurement of plutonium nitrate solution in accountancy tank. The volume of the solution can be estimated by two differential pressures between three dip-tubes, in which the air is purged by an compressor. One of the differential pressure corresponds to the density of the solution, and another corresponds to the surface level of the solution in the tank. The measurement of the differential pressure contains many uncertain errors, such as precision of pressure transducer, fluctuation of back-pressure, generation of bubbles at the front of the dip-tubes, non-uniformity of temperature and density of the solution, pressure drop in the dip-tube, and so on. The various excess pressures at the volume measurement are discussed and corrected by a reasonable method. High precision-differential pressure measurement system is developed with a quartz oscillation type transducer which converts a differential pressure to a digital signal. The developed system is used for inspection by the government and IAEA. (M. Suetake)

  14. Accurate measure by weight of liquids in industry. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Muller, M.R.

    1992-12-12

    This research`s focus was to build a prototype of a computerized liquid dispensing system. This liquid metering system is based on the concept of altering the representative volume to account for temperature changes in the liquid to be dispensed. This is actualized by using a measuring tank and a temperature compensating displacement plunger. By constantly monitoring the temperature of the liquid, the plunger can be used to increase or decrease the specified volume to more accurately dispense liquid with a specified mass. In order to put the device being developed into proper engineering perspective, an extensive literature review was undertaken on all areas of industrial metering of liquids with an emphasis on gravimetric methods.

  15. Accurate measure by weight of liquids in industry

    Energy Technology Data Exchange (ETDEWEB)

    Muller, M.R.

    1992-12-12

    This research's focus was to build a prototype of a computerized liquid dispensing system. This liquid metering system is based on the concept of altering the representative volume to account for temperature changes in the liquid to be dispensed. This is actualized by using a measuring tank and a temperature compensating displacement plunger. By constantly monitoring the temperature of the liquid, the plunger can be used to increase or decrease the specified volume to more accurately dispense liquid with a specified mass. In order to put the device being developed into proper engineering perspective, an extensive literature review was undertaken on all areas of industrial metering of liquids with an emphasis on gravimetric methods.

  16. Electron Microprobe Analysis Techniques for Accurate Measurements of Apatite

    Science.gov (United States)

    Goldoff, B. A.; Webster, J. D.; Harlov, D. E.

    2010-12-01

    Apatite [Ca5(PO4)3(F, Cl, OH)] is a ubiquitous accessory mineral in igneous, metamorphic, and sedimentary rocks. The mineral contains halogens and hydroxyl ions, which can provide important constraints on fugacities of volatile components in fluids and other phases in igneous and metamorphic environments in which apatite has equilibrated. Accurate measurements of these components in apatite are therefore necessary. Analyzing apatite by electron microprobe (EMPA), which is a commonly used geochemical analytical technique, has often been found to be problematic and previous studies have identified sources of error. For example, Stormer et al. (1993) demonstrated that the orientation of an apatite grain relative to the incident electron beam could significantly affect the concentration results. In this study, a variety of alternative EMPA operating conditions for apatite analysis were investigated: a range of electron beam settings, count times, crystal grain orientations, and calibration standards were tested. Twenty synthetic anhydrous apatite samples that span the fluorapatite-chlorapatite solid solution series, and whose halogen concentrations were determined by wet chemistry, were analyzed. Accurate measurements of these samples were obtained with many EMPA techniques. One effective method includes setting a static electron beam to 10-15nA, 15kV, and 10 microns in diameter. Additionally, the apatite sample is oriented with the crystal’s c-axis parallel to the slide surface and the count times are moderate. Importantly, the F and Cl EMPA concentrations are in extremely good agreement with the wet-chemical data. We also present EMPA operating conditions and techniques that are problematic and should be avoided. J.C. Stormer, Jr. et al., Am. Mineral. 78 (1993) 641-648.

  17. UAV multirotor platform for accurate turbulence measurements in the atmosphere

    Science.gov (United States)

    Carbajo Fuertes, Fernando; Wilhelm, Lionel; Sin, Kevin Edgar; Hofer, Matthias; Porté-Agel, Fernando

    2017-04-01

    One of the most challenging tasks in atmospheric field studies for wind energy is to obtain accurate turbulence measurements at any location inside the region of interest for a wind farm study. This volume would ideally include from several hundred meters to several kilometers around it and from ground height to the top of the boundary layer. An array of meteorological masts equipped with several sonic anemometers to cover all points of interest would be the best in terms of accuracy and data availability, but it is an obviously unfeasible solution. On the other hand, the evolution of wind LiDAR technology allows to measure at any point in space but unfortunately it involves two important limitations: the first one is the relatively low spatial and temporal resolution when compared to a sonic anemometer and the second one is the fact that the measurements are limited to the velocity component parallel to the laser beam (radial velocity). To overcome the aforementioned drawbacks, a UAV multirotor platform has been developed. It is based on a state-of-the-art octocopter with enough payload to carry laboratory-grade instruments for the measurement of time-resolved atmospheric pressure, three-component velocity vector and temperature; and enough autonomy to fly from 10 to 20 minutes, which is a standard averaging time in most atmospheric measurement applications. The UAV uses a gyroscope, an accelerometer, a GPS and an algorithm has been developed and integrated for the correction of any orientation and movement. This UAV platform opens many possibilities for the study of features that have been almost exclusively studied until now in wind tunnel such as wind turbine blade tip vortex characteristics, near-wake to far-wake transition, momentum entrainment from the higher part of the boundary layer in wind farms, etc. The validation of this new measurement technique has been performed against sonic anemometry in terms of wind speed and temperature time series as well as

  18. A novel technique for highly accurate gas exchange measurements

    Science.gov (United States)

    Kalkenings, R. K.; Jähne, B. J.

    2003-04-01

    The Heidelberg Aeolotron is a circular wind-wave facility for investigating air-sea gas exchange. In this contribution a novel technique for measuring highly accurate transfer velocities k of mass transfer will be presented. Traditionally, in mass balance techniques the constant of decay for gas concentrations over time is measured. The major drawback of this concept is the long time constant. At low wind speeds and a water height greater than 1 m the period of observation has to be several days. In a gas-tight facility such as the Aeolotron, the transfer velocity k can be computed from the concentration in the water body and the change of concentration in the gas space. Owing to this fact, transfer velocities are gained while greatly reducing the measuring times to less than one hour. The transfer velocity k of a tracer can be parameterized as k=1/β \\cdot u_* \\cdot Sc^n, with the Schmidt Number Sc, shear velocity u_* and the dimensionless transfer resistance β. The Schmidt Number exponent n can be derived from simultaneous measurements of different tracers. Since these tracers are of different Schmidt number, the shear velocity is not needed. To allow for Schmidt numbers spanning a hole decade, in our experiments He, H_2, N_2O and F12 are used. The relative accuracy of measuring the transfer velocity was improved to less than 2%. In 9 consecutive experiments conducted at a wind speed of 6.2 m/s, the deviation of the Schmidt number exponent was found to be just under 0.02. This high accuracy will allow precisely determining the transition of the Schmidt number exponent from n=2/3 to n=0.5 from a flat to wavy water surface. In order to quantify gas exchange not only the wind speed is important. Surfactants have a pronounced effect on the wave field and lead to a drastic reduction in the transfer velocity. In the Aeolotron measurements were conducted with a variety of measuring devices, ranging from an imaging slope gauge (ISG) to thermal techniques with IR

  19. How accurately can videokeratographic systems measure surface elevation?

    Science.gov (United States)

    Applegate, R A; Nuñez, R; Buettner, J; Howland, H C

    1995-11-01

    Surface topography, as opposed to dioptric topography, defines the corneal surface in simple terms without assumptions. Accordingly, it is important to know how well surface topography can be measured with current videokeratometric machines. The purpose of this paper is to quantify the accuracy with which the TMS-1 Corneal Modeling System can measure the surface topography of calibrated spherical, elliptical, and bicurve surfaces. The Computed Anatomy TMS-1 videokeratometer was used to measure three spherical, three elliptical, and two bicurve surfaces with known characteristics. Surface characteristics were either back-calculated from the dioptric files or directly obtained from the TMS-1 elevation file for each of 6400 points (256 points in each of 25 rings). The accuracy with which each method determined the true surface was quantified by calculating the root mean squared error (RMSE) of the 6400 measured surface elevations from the known surface elevation at each sampling point. (1) For spherical and elliptical surfaces, back-calculation of surface elevation from the dioptric file can be made with RMSE of 5 mu or less. (2) For spheres but not elliptical surfaces the TMS-1 elevation file defines the surface with RMSE 5 mu or less. (3) The surface area measured by placido-based videokeratometers varies with surface curvature. (4) RMSE in measured surface elevation increase as the distance from the videokeratometric axis increases. (5) For bicurves, the dioptric maps are smoothed by the TMS-1 over abrupt transitions and for large transitions never recover. Additionally, our back-calculation methods further smooth abrupt transitions, making the RMSE of the bicurve surface that is back-calculated from the dioptric file larger than the RMSE of the surface generated from the TMS-1 elevation file. Surface elevations can be back-calculated from dioptric files with RMSE of 5 microns or less for spheres and elliptical surfaces as long as there are no areas of abrupt

  20. Accurate position estimation methods based on electrical impedance tomography measurements

    Science.gov (United States)

    Vergara, Samuel; Sbarbaro, Daniel; Johansen, T. A.

    2017-08-01

    than 0.05% of the tomograph radius value. These results demonstrate that the proposed approaches can estimate an object’s position accurately based on EIT measurements if enough process information is available for training or modelling. Since they do not require complex calculations it is possible to use them in real-time applications without requiring high-performance computers.

  1. Accurate measurement and influence on device reliability of defect density of a light-emitting diode

    Science.gov (United States)

    Guo, Zu-Qiang; Qian, Ke-Yuan

    2013-10-01

    A method of accurately measuring the defect density of a high-power light-emitting diode (LED) is proposed. The method is based on measuring the number of emitting photons in the magnitude of 105 under the injection current as weak as nA and calculating the non-radiative recombination coefficient which is related to defect density. Defect density is obtained with the self-developed measurement system, and it is demonstrated that defect density has an important influence on LED optical properties like luminous flux and internal quantum efficiency (IQE). At the same time, a batch of GaN-based LEDs with the chip size of 1 mm × 1 mm are selected to conduct the accelerated aging tests lasting for 1000 hours. The results show that defect density exhibits a greater variation and is more sensitive to LED reliability than luminous flux during aging tests. Based on these results, it is concluded that for the GaN-based LED with a chip size of 1mm × 1mm, if its defect density is over 1017/cm3, the LED device performance suffers a serious deterioration, and finally fails.

  2. Accurate micro Hall effect measurements on scribe line pads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Petersen, Dirch Hjorth; Wang, Fei

    2009-01-01

    Hall mobility and sheet carrier density are important parameters to monitor in advanced semiconductor production. If micro Hall effect measurements are done on small pads in scribe lines, these parameters may be measured without using valuable test wafers. We report how Hall mobility can...... be extracted from micro four-point measurements performed on a rectangular pad. The dimension of the investigated pad is 400 × 430 ¿m2, and the probe pitches range from 20 ¿m to 50 ¿m. The Monte Carlo method is used to find the optimal way to perform the Hall measurement and extract Hall mobility most...

  3. Spherical near-field antenna measurements — The most accurate antenna measurement technique

    DEFF Research Database (Denmark)

    Breinbjerg, Olav

    2016-01-01

    The spherical near-field antenna measurement technique combines several advantages and generally constitutes the most accurate technique for experimental characterization of radiation from antennas. This paper/presentation discusses these advantages, briefly reviews the early history and present...... status, and addresses future challenges for spherical near-field antenna measurements; in particular, from the viewpoint of the DTU-ESA Spherical Near-Field Antenna Test Facility....

  4. Problems with Accurate Atomic Lfetime Measurements of Multiply Charged Ions

    Energy Technology Data Exchange (ETDEWEB)

    Trabert, E

    2009-02-19

    A number of recent atomic lifetime measurements on multiply charged ions have reported uncertainties lower than 1%. Such a level of accuracy challenges theory, which is a good thing. However, a few lessons learned from earlier precision lifetime measurements on atoms and singly charged ions suggest to remain cautious about the systematic errors of experimental techniques.

  5. Accurate Measurements of Spectral Reflectance in Picasso's Guernica Painting.

    Science.gov (United States)

    de Luna, Javier Muñoz; Fernandez-Balbuena, Antonio Alvarez; Vázquez, Daniel; Melgosa, Manuel; Durán, Humberto; García, Jorge; Muro, Carmen

    2016-01-01

    The use of non-invasive spectral measurements to control the conservation status is a part of the preventive conservation of artworks which nowadays is becoming increasingly interesting. This paper describes how to use a spectral measuring device and an illumination system specifically designed for such a task in a very large dimension artwork painting (7.8 m wide × 3.5 m high). The system, controlled by a Cartesian robot, allows spectral measurements in a spectral range of 400-780 nm. The measured data array has a total of 2201 circular regions with 5.5 mm spot diameter placed on a square grid. Colorimetric calculations performed from these spectral measurements may be used to characterize color shifts related to reflectance changes in specific areas of the paint. A color shifting from the expected gray has been shown. © The Author(s) 2015.

  6. Toroidal charge exchange recombination spectroscopy measurements on MST

    Energy Technology Data Exchange (ETDEWEB)

    Magee, R. M.; Den Hartog, D. J.; Fiksel, G.; Kumar, S. T. A. [University of Wisconsin, 1150 University Avenue, Madison, Wisconsin 53706 (United States); Craig, D. [Wheaton College, 501 College Avenue, Wheaton, Illinois 60187 (United States)

    2010-10-15

    Charge exchange recombination spectroscopy measurements of the poloidal component of the C{sup +6} temperature and flow in the Madison Symmetric Torus have been vital in advancing the understanding of the ion dynamics in the reversed field pinch. Recent work has expanded the diagnostic capability to include toroidal measurements. A new toroidal view overcomes a small signal-to-background ratio (5%-15%) to make the first localized measurements of the parallel component of the impurity ion temperature in the core of the reversed field pinch. The measurement is made possible through maximal light collection in the optical design and extensive atomic modeling in the fitting routine. An absolute calibration of the system allowed the effect of Poisson noise in the signal on line fitting to be quantified. The measurement is made by stimulating emission with a recently upgraded 50 keV hydrogen diagnostic neutral beam. Radial localization is {approx}4 cm{sup 2}, and good temporal resolution (100 {mu}s) is achieved by making simultaneous emission and background measurements with a high-throughput double-grating spectrometer.

  7. An accurate method for measuring triploidy of larval fish spawns

    Science.gov (United States)

    Jenkins, Jill A.; Draugelis-Dale, Rassa O.; Glennon, Robert; Kelly, Anita; Brown, Bonnie L.; Morrison, John

    2017-01-01

    A standard flow cytometric protocol was developed for estimating triploid induction in batches of larval fish. Polyploid induction treatments are not guaranteed to be 100% efficient, thus the ability to quantify the proportion of triploid larvae generated by a particular treatment helps managers to stock high-percentage spawns and researchers to select treatments for efficient triploid induction. At 3 d posthatch, individual Grass Carp Ctenopharyngodon idella were mechanically dissociated into single-cell suspensions; nuclear DNA was stained with propidium iodide then analyzed by flow cytometry. Following ploidy identification of individuals, aliquots of diploid and triploid cell suspensions were mixed to generate 15 levels (0–100%) of known triploidy (n = 10). Using either 20 or 50 larvae per level, the observed triploid percentages were lower than the known, actual values. Using nonlinear regression analyses, quadratic equations solved for triploid proportions in mixed samples and corresponding estimation reference plots allowed for predicting triploidy. Thus, an accurate prediction of the proportion of triploids in a spawn can be made by following a standard larval processing and analysis protocol with either 20 or 50 larvae from a single spawn, coupled with applying the quadratic equations or reference plots to observed flow cytometry results. Due to the universality of triploid DNA content being 1.5 times the diploid level and because triploid fish consist of fewer cells than diploids, this method should be applicable to other produced triploid fish species, and it may be adapted for use with bivalves or other species where batch analysis is appropriate.

  8. Accurate Blood Flow Measurements : Are Artificial Tracers Necessary?

    NARCIS (Netherlands)

    Poelma, C.; Kloosterman, A.; Hierck, B.P.; Westerweel, J.

    2012-01-01

    Imaging-based blood flow measurement techniques, such as particle image velocimetry, have become an important tool in cardiovascular research. They provide quantitative information about blood flow, which benefits applications ranging from developmental biology to tumor perfusion studies. Studies

  9. Accurate antenna reflector loss measurements for radiometer calibration budget

    DEFF Research Database (Denmark)

    Skou, Niels

    1996-01-01

    Antenna reflector losses may play an important role in the calibration budget for a microwave radiometer. If the losses are small they are difficult to measure by traditional means. However, they can be assessed directly by radiometric means using the sky brightness temperature as incident radiat...... radiation. The paper describes how such measurements are carried out as well as a suitable experimental set-up. The main reflector of the European Space Agency's MIMR system is used to demonstrate the principle...

  10. Visual texture accurate material appearance measurement, representation and modeling

    CERN Document Server

    Haindl, Michal

    2013-01-01

    This book surveys the state of the art in multidimensional, physically-correct visual texture modeling. Features: reviews the entire process of texture synthesis, including material appearance representation, measurement, analysis, compression, modeling, editing, visualization, and perceptual evaluation; explains the derivation of the most common representations of visual texture, discussing their properties, advantages, and limitations; describes a range of techniques for the measurement of visual texture, including BRDF, SVBRDF, BTF and BSSRDF; investigates the visualization of textural info

  11. Third trimester ultrasound soft-tissue measurements accurately predicts macrosomia.

    Science.gov (United States)

    Maruotti, Giuseppe Maria; Saccone, Gabriele; Martinelli, Pasquale

    2017-04-01

    To evaluate the accuracy of sonographic measurements of fetal soft tissue in the prediction of macrosomia. Electronic databases were searched from their inception until September 2015 with no limit for language. We included only studies assessing the accuracy of sonographic measurements of fetal soft tissue in the abdomen or thigh in the prediction of macrosomia  ≥34 weeks of gestation. The primary outcome was the accuracy of sonographic measurements of fetal soft tissue in the prediction of macrosomia. We generated the forest plot for the pooled sensitivity and specificity with 95% confidence interval (CI). Additionally, summary receiver-operating characteristics (ROC) curves were plotted and the area under the curve (AUC) was also computed to evaluate the overall performance of the diagnostic test accuracy. Three studies, including 287 singleton gestations, were analyzed. The pooled sensitivity of sonographic measurements of abdominal or thigh fetal soft tissue in the prediction of macrosomia was 80% (95% CI: 66-89%) and the pooled specificity was 95% (95% CI: 91-97%). The AUC for diagnostic accuracy of sonographic measurements of fetal soft tissue in the prediction of macrosomia was 0.92 and suggested high diagnostic accuracy. Third-trimester sonographic measurements of fetal soft tissue after 34 weeks may help to detect macrosomia with a high degree of accuracy. The pooled detection rate was 80%. A standardization of measurements criteria, reproducibility, building reference charts of fetal subcutaneous tissue and large studies to assess the optimal cutoff of fetal adipose thickness are necessary before the introduction of fetal soft-tissue markers in the clinical practice.

  12. Gain Instabilities in Photomultipliers: How Accurate are Photon Counting Measurements?

    Science.gov (United States)

    Rosen, W. A.; Chromey, F. R.

    1984-01-01

    Experiments performed on five commercially available photomultiplier tubes indicate that gain instabilities can be an important source of error in photon counting measurements at the 1% level. It is shown that the error cannot be significantly reduced by standard differential measurement techniques. Analysis of time variations in the pulse height distribution is shown to be a sensitive diagnostic tool for the measurement of gain variations. Using this technique it is found that gain variations occur at counting rates as low as 100 Hz. It is argued that such errors will be present at some level in all tubes. Several calibrating schemes capable of reducing the error to below the 0.1% level are discussed.

  13. A simple and accurate relative alternative magnetic susceptibility measurement technique

    Energy Technology Data Exchange (ETDEWEB)

    Zawilski, B.M., E-mail: zawilski@grenoble.cnrs.f [Institut Neel-MCMF--CNRS-UJF 25, Rue des Martyrs, F 38042 Grenoble Cedex (France); Marcus, J.; Plaindoux, P. [Institut Neel-MCMF-CNRS-UJF 25, Rue des Martyrs, F 38042 Grenoble Cedex (France)

    2010-09-15

    Investigation of relative AC magnetic susceptibility interests for many magnetic transition studies such as superconductor transition. A technique based on mutual or self inductive measure provides a fast and relatively easy (no contact) way to determinate the temperature of any transition affecting the magnetic susceptibility. The half Wheatstone inductive/resistive bridge is used instead of the usual RLC quarter bridge in order to balance the bore inductance of the coil. A comparison between quarter and half bridge measurements illustrates the accuracy of our device.

  14. Highly accurate photogrammetric measurements of the Planck reflectors

    Science.gov (United States)

    Amiri Parian, Jafar; Gruen, Armin; Cozzani, Alessandro

    2017-11-01

    The Planck mission of the European Space Agency (ESA) is designed to image the anisotropies of the Cosmic Background Radiation Field over the whole sky. To achieve this aim, sophisticated reflectors are used as part of the Planck telescope receiving system. The system consists of secondary and primary reflectors which are sections of two different ellipsoids of revolution with mean diameters of 1 and 1.6 meters. Deformations of the reflectors which influence the optical parameters and the gain of receiving signals are investigated in vacuum and at very low temperatures. For this investigation, among the various high accuracy measurement techniques, photogrammetry was selected. With respect to the photogrammetric measurements, special considerations had to be taken into account in design steps, measurement arrangement and data processing to achieve very high accuracies. The determinability of additional parameters of the camera under the given network configuration, datum definition, reliability and precision issues as well as workspace limits and propagating errors from different sources are considered. We have designed an optimal photogrammetric network by heuristic simulation for the flight model of the primary and the secondary reflectors with relative precisions better than 1:1000'000 and 1:400'000 to achieve the requested accuracies. A least squares best fit ellipsoid method was developed to determine the optical parameters of the reflectors. In this paper we will report about the procedures, the network design and the results of real measurements.

  15. Accurate image search using the contextual dissimilarity measure.

    Science.gov (United States)

    Jegou, Hervé; Schmid, Cordelia; Harzallah, Hedi; Verbeek, Jakob

    2010-01-01

    This paper introduces the contextual dissimilarity measure, which significantly improves the accuracy of bag-of-features-based image search. Our measure takes into account the local distribution of the vectors and iteratively estimates distance update terms in the spirit of Sinkhorn's scaling algorithm, thereby modifying the neighborhood structure. Experimental results show that our approach gives significantly better results than a standard distance and outperforms the state of the art in terms of accuracy on the Nistér-Stewénius and Lola data sets. This paper also evaluates the impact of a large number of parameters, including the number of descriptors, the clustering method, the visual vocabulary size, and the distance measure. The optimal parameter choice is shown to be quite context-dependent. In particular, using a large number of descriptors is interesting only when using our dissimilarity measure. We have also evaluated two novel variants: multiple assignment and rank aggregation. They are shown to further improve accuracy at the cost of higher memory usage and lower efficiency.

  16. ACCUWIND - Accurate wind speed measurements in wind energy - Summary report

    DEFF Research Database (Denmark)

    Friis Pedersen, Troels; Dahlberg, J.-Å.; Cuerva, A.

    2006-01-01

    The cup anemometer is at present the standard instrument used for mean wind speed measurement in wind energy. It is being applied in high numbers around the world for wind energy assessments. It is also applied exclusively for accredited power performancemeasurements for certification...

  17. ACCURATE TEMPERATURE MEASUREMENTS IN A NATURALLY-ASPIRATED RADIATION SHIELD

    Energy Technology Data Exchange (ETDEWEB)

    Kurzeja, R.

    2009-09-09

    Experiments and calculations were conducted with a 0.13 mm fine wire thermocouple within a naturally-aspirated Gill radiation shield to assess and improve the accuracy of air temperature measurements without the use of mechanical aspiration, wind speed or radiation measurements. It was found that this thermocouple measured the air temperature with root-mean-square errors of 0.35 K within the Gill shield without correction. A linear temperature correction was evaluated based on the difference between the interior plate and thermocouple temperatures. This correction was found to be relatively insensitive to shield design and yielded an error of 0.16 K for combined day and night observations. The correction was reliable in the daytime when the wind speed usually exceeds 1 m s{sup -1} but occasionally performed poorly at night during very light winds. Inspection of the standard deviation in the thermocouple wire temperature identified these periods but did not unambiguously locate the most serious events. However, estimates of sensor accuracy during these periods is complicated by the much larger sampling volume of the mechanically-aspirated sensor compared with the naturally-aspirated sensor and the presence of significant near surface temperature gradients. The root-mean-square errors therefore are upper limits to the aspiration error since they include intrinsic sensor differences and intermittent volume sampling differences.

  18. An approach for the accurate measurement of social morality levels.

    Science.gov (United States)

    Liu, Haiyan; Chen, Xia; Zhang, Bo

    2013-01-01

    In the social sciences, computer-based modeling has become an increasingly important tool receiving widespread attention. However, the derivation of the quantitative relationships linking individual moral behavior and social morality levels, so as to provide a useful basis for social policy-making, remains a challenge in the scholarly literature today. A quantitative measurement of morality from the perspective of complexity science constitutes an innovative attempt. Based on the NetLogo platform, this article examines the effect of various factors on social morality levels, using agents modeling moral behavior, immoral behavior, and a range of environmental social resources. Threshold values for the various parameters are obtained through sensitivity analysis; and practical solutions are proposed for reversing declines in social morality levels. The results show that: (1) Population size may accelerate or impede the speed with which immoral behavior comes to determine the overall level of social morality, but it has no effect on the level of social morality itself; (2) The impact of rewards and punishment on social morality levels follows the "5∶1 rewards-to-punishment rule," which is to say that 5 units of rewards have the same effect as 1 unit of punishment; (3) The abundance of public resources is inversely related to the level of social morality; (4) When the cost of population mobility reaches 10% of the total energy level, immoral behavior begins to be suppressed (i.e. the 1/10 moral cost rule). The research approach and methods presented in this paper successfully address the difficulties involved in measuring social morality levels, and promise extensive application potentials.

  19. An approach for the accurate measurement of social morality levels.

    Directory of Open Access Journals (Sweden)

    Haiyan Liu

    Full Text Available In the social sciences, computer-based modeling has become an increasingly important tool receiving widespread attention. However, the derivation of the quantitative relationships linking individual moral behavior and social morality levels, so as to provide a useful basis for social policy-making, remains a challenge in the scholarly literature today. A quantitative measurement of morality from the perspective of complexity science constitutes an innovative attempt. Based on the NetLogo platform, this article examines the effect of various factors on social morality levels, using agents modeling moral behavior, immoral behavior, and a range of environmental social resources. Threshold values for the various parameters are obtained through sensitivity analysis; and practical solutions are proposed for reversing declines in social morality levels. The results show that: (1 Population size may accelerate or impede the speed with which immoral behavior comes to determine the overall level of social morality, but it has no effect on the level of social morality itself; (2 The impact of rewards and punishment on social morality levels follows the "5∶1 rewards-to-punishment rule," which is to say that 5 units of rewards have the same effect as 1 unit of punishment; (3 The abundance of public resources is inversely related to the level of social morality; (4 When the cost of population mobility reaches 10% of the total energy level, immoral behavior begins to be suppressed (i.e. the 1/10 moral cost rule. The research approach and methods presented in this paper successfully address the difficulties involved in measuring social morality levels, and promise extensive application potentials.

  20. An Approach for the Accurate Measurement of Social Morality Levels

    Science.gov (United States)

    Liu, Haiyan; Chen, Xia; Zhang, Bo

    2013-01-01

    In the social sciences, computer-based modeling has become an increasingly important tool receiving widespread attention. However, the derivation of the quantitative relationships linking individual moral behavior and social morality levels, so as to provide a useful basis for social policy-making, remains a challenge in the scholarly literature today. A quantitative measurement of morality from the perspective of complexity science constitutes an innovative attempt. Based on the NetLogo platform, this article examines the effect of various factors on social morality levels, using agents modeling moral behavior, immoral behavior, and a range of environmental social resources. Threshold values for the various parameters are obtained through sensitivity analysis; and practical solutions are proposed for reversing declines in social morality levels. The results show that: (1) Population size may accelerate or impede the speed with which immoral behavior comes to determine the overall level of social morality, but it has no effect on the level of social morality itself; (2) The impact of rewards and punishment on social morality levels follows the “5∶1 rewards-to-punishment rule,” which is to say that 5 units of rewards have the same effect as 1 unit of punishment; (3) The abundance of public resources is inversely related to the level of social morality; (4) When the cost of population mobility reaches 10% of the total energy level, immoral behavior begins to be suppressed (i.e. the 1/10 moral cost rule). The research approach and methods presented in this paper successfully address the difficulties involved in measuring social morality levels, and promise extensive application potentials. PMID:24312189

  1. Accurate Measurement of Magnetic Resonance Imaging Gradient Characteristics

    Directory of Open Access Journals (Sweden)

    Hui Liu

    2013-12-01

    Full Text Available Recently, gradient performance and fidelity has become of increasing interest, as the fidelity of the magnetic resonance (MR image is somewhat dependent on the fidelity of the gradient system. In particular, for high fidelity non-Cartesian imaging, due to non-fidelity of the gradient system, it becomes necessary to know the actual k-space trajectory as opposed to the requested trajectory. In this work we show that, by considering the gradient system as a linear time-invariant system, the gradient impulse response function (GIRF can be reliably measured to a relatively high degree of accuracy with a simple setup, using a small phantom and a series of simple experiments. It is shown experimentally that the resulting GIRF is able to predict actual gradient performance with a high degree of accuracy. The method captures not only the frequency response but also gradient timing errors and artifacts due to mechanical vibrations of the gradient system. Some discussion is provided comparing the method presented here with other analogous methods, along with limitations of these methods.

  2. Propargyl Recombination: Estimation of the High Temperature, Low Pressure Rate Constant from Flame Measurements

    DEFF Research Database (Denmark)

    Rasmussen, Christian Lund; Skjøth-Rasmussen, Martin Skov; Jensen, Anker

    2005-01-01

    The most important cyclization reaction in hydrocarbon flames is probably recombination of propargyl radicals. This reaction may, depending on reaction conditions, form benzene, phenyl or fulvene, as well as a range of linear products. A number of rate measurements have been reported for C3H3 + C3H......3 at temperatures below 1000 K, while data at high temperature and low pressure only can be obtained from flames. In the present work, an estimate of the rate constant for the reaction at 1400 +/- 50 K and 20 Torr is obtained from analysis of the fuel-rich acetylene flame of Westmoreland, Howard......, and Longwell. Based on an accurate modeling of the flame structure, in particular the concentration profile of propargyl, we estimate the rate constant by fitting the kinetic modeling predictions to the measured benzene and phenyl profiles. The best agreement is obtained with k = 1.3 x 10(12) cm(3)/mol...

  3. He/H ratio for Cosmology: Accurate He recombination coefficients including fine structure and singlet-triplet mixing

    Science.gov (United States)

    Bauman, R. P.; Ferland, G. J.; MacAdam, K. B.

    2002-12-01

    The primordial abundance of helium and its subsequent production in stars are primarily determined from recombination lines in HII Regions. Accuracies better than a percent must be obtained to make definitive tests in cosmology. We report the results of a recalculation of the helium recombination process. Our work builds on previous calculations by improving the physical treatment of radiative recombination and subsequent cascades by explicitly including fine structure in the helium transition rates and energies. Transitions which are the result of singlet-triplet mixing are included in this work for the first time. We base our transition rates and energies on the results of Drake which include magnetic and relativistic interactions. Previous methodologies were largely based on variational, hydrogenic or Coulomb approximation calculations that did not include these interactions, thus entailing an unknown degree of inaccuracy. Comparisons with previous calculations are presented along with an assessment of the remaining major uncertainties. This project is supported by the NSF and NASA through grants AST 0071180 and NAG5-8212. G.W.F Drake, Atomic, Molecular, & Optical Physics Handbook, AIP Press, Woodbury New York, 1996.

  4. PERSEE: description of a new concept for nulling interferometry recombination and OPD measurement

    Science.gov (United States)

    Jacquinod, Sophie; Cassaing, Frédéric; Le Duigou, Jean-Michel; Barillot, Marc; Ollivier, Marc; Houairi, Kamel; Lemarquis, Frederic; Amans, Jean-Philippe

    2008-07-01

    Nulling interferometry requires, among other things, a symmetric recombination module and an optical path difference control system. The symmetric recombination stage has been particularly studied over the last ten years and several concepts are now well known. One of them is the "Modified Mach Zehnder" (MMZ) interferometer, proposed by Serabyn and Colavita (2001) [1]. In this paper, we describe a new version of the MMZ beam combiner which provides a deep null signal in the science channel and, at the same time, phase-sensitive signals in the so-called co-phasing channel. From the latter, accurate optical path difference measurements can be derived. This beam combiner works in the 0.8 to 3.3 μm spectral range (0.8 to 1.5 μm for the co-phasing channel and 1.65 to 3.3 μm for the science channel). Both optical functions can be implemented in the same device thanks to an original optical design involving dedicated phase shifts. In this paper, we describe its principle and detail the optical and mechanical design.

  5. Surface recombination measurements on III-V candidate materials for nanostructure light-emitting diodes

    Science.gov (United States)

    Boroditsky, M.; Gontijo, I.; Jackson, M.; Vrijen, R.; Yablonovitch, E.; Krauss, T.; Cheng, Chuan-Cheng; Scherer, A.; Bhat, R.; Krames, M.

    2000-04-01

    Surface recombination is an important characteristic of an optoelectronic material. Although surface recombination is a limiting factor for very small devices it has not been studied intensively. We have investigated surface recombination velocity on the exposed surfaces of the AlGaN, InGaAs, and InGaAlP material systems by using absolute photoluminescence quantum efficiency measurements. Two of these three material systems have low enough surface recombination velocity to be usable in nanoscale photonic crystal light-emitting diodes.

  6. Experimental apparatus for photon/ion coincidence measurements of dielectronic recombination

    Science.gov (United States)

    Gardner, L. D.; Kohl, J. L.; Lafyatis, G. P.; Young, A. R.; Chutjian, A.

    1986-01-01

    An inclined beams apparatus for the measurement of absolute cross sections for dielectronic recombination between free electrons and singly or multiply charged ions is described. The collision products, a photon and a lower-charge-state ion, are detected in delayed coincidence. Measurements of dielectronic recombination in C(3+) are described to illustrate the use of the apparatus and techniques. Verification of the calibrations and operation of the apparatus is demonstrated through measurements of charge transfer and electron impact excitation.

  7. Measuring Accurate Body Parameters of Dressed Humans with Large-Scale Motion Using a Kinect Sensor

    Directory of Open Access Journals (Sweden)

    Sidan Du

    2013-08-01

    Full Text Available Non-contact human body measurement plays an important role in surveillance, physical healthcare, on-line business and virtual fitting. Current methods for measuring the human body without physical contact usually cannot handle humans wearing clothes, which limits their applicability in public environments. In this paper, we propose an effective solution that can measure accurate parameters of the human body with large-scale motion from a Kinect sensor, assuming that the people are wearing clothes. Because motion can drive clothes attached to the human body loosely or tightly, we adopt a space-time analysis to mine the information across the posture variations. Using this information, we recover the human body, regardless of the effect of clothes, and measure the human body parameters accurately. Experimental results show that our system can perform more accurate parameter estimation on the human body than state-of-the-art methods.

  8. Ocean Lidar Measurements of Beam Attenuation and a Roadmap to Accurate Phytoplankton Biomass Estimates

    Directory of Open Access Journals (Sweden)

    Hu Yongxiang

    2016-01-01

    On July 17, 2014, the CALIPSO satellite was tilted 30° off-nadir for one nighttime orbit in order to minimize ocean surface backscatter and demonstrate the lidar ocean subsurface measurement concept from space. Depolarization ratios of ocean subsurface backscatter are measured accurately. Beam attenuation coefficients computed from the depolarization ratio measurements compare well with empirical estimates from ocean color measurements. We further verify the beam attenuation coefficient retrievals using aircraft-based high spectral resolution lidar (HSRL data that are collocated with in-water optical measurements.

  9. Importance of accurate measurements in nutrition research: dietary flavonoids as a case study

    Science.gov (United States)

    Accurate measurements of the secondary metabolites in natural products and plant foods are critical to establishing diet/health relationships. There are as many as 50,000 secondary metabolites which may influence human health. Their structural and chemical diversity present a challenge to analytic...

  10. An investigation of highly accurate and precise robotic hole measurements using non-contact devices

    Directory of Open Access Journals (Sweden)

    Usman Zahid

    2016-01-01

    Full Text Available Industrial robots arms are widely used in manufacturing industry because of their support for automation. However, in metrology, robots have had limited application due to their insufficient accuracy. Even using error compensation and calibration methods, robots are not effective for micrometre (μm level metrology. Non-contact measurement devices can potentially enable the use of robots for highly accurate metrology. However, the use of such devices on robots has not been investigated. The research work reported in this paper explores the use of different non-contact measurement devices on an industrial robot. The aim is to experimentally investigate the effects of robot movements on the accuracy and precision of measurements. The focus has been on assessing the ability to accurately measure various geometric and surface parameters of holes despite the inherent inaccuracies of industrial robot. This involves the measurement of diameter, roundness and surface roughness. The study also includes scanning of holes for measuring internal features such as start and end point of a taper. Two different non-contact measurement devices based on different technologies are investigated. Furthermore, effects of eccentricity, vibrations and thermal variations are also assessed. The research contributes towards the use of robots for highly accurate and precise robotic metrology.

  11. Low-cost small action cameras in stereo generates accurate underwater measurements of fish

    OpenAIRE

    Letessier, T. B.; Juhel, Jean-Baptiste; Vigliola, Laurent; Meeuwig, J. J.

    2015-01-01

    Small action cameras have received interest for use in underwater videography because of their low-cost, standardised housing, widespread availability and small size. Here, we assess the capacity of GoPro action cameras to provide accurate stereo-measurements of fish in comparison to the Sony handheld cameras that have traditionally been used for this purpose. Standardised stereo-GoPro and Sony systems were employed to capture measurements of known-length targets in a pool to explore the infl...

  12. The mean machine; accurate non-invasive blood pressure measurement in the critically ill patient.

    Science.gov (United States)

    Muecke, Sandy; Bersten, Andrew; Plummer, John

    2009-10-01

    Accurate indirect prehospital blood pressure measurement in the critically ill patient remains an important challenge to both patient management and prehospital research. Ambulatory blood pressure measuring devices have not been trialled for prehospital use in critically ill patients. Prior to prehospital validation where conditions are suboptimal, we aimed to test under favourable conditions in the Intensive Care Unit, a selection of ambulatory devices that may be suitable for use in the field. Systolic, diastolic and mean pressures of three ambulatory devices were compared to the average of 1 min of independently recorded, high fidelity intra-arterial reference pressures. Eighteen critically ill patients were recruited. Device performance was required to fulfil the Association for the Advancement of Medical Instrumentation (AAMI) protocol. Additionally, agreement between measurement methods was examined using Bland-Altman plots. Two-level linear mixed model analyses were under- taken. For each device, 150 paired measurements (arterial reference and device) were analysed. According to the AAMI protocol, no device measured systolic pressures accurately. One device measured diastolic pressures accurately. Integrated mean pressures were accurately measured by all devices. Overall, SunTech Medical's Oscar 2 performed best with mean pressure error not exceeding 17 mmHg. For this device, Bland-Altman plots showed uniform agreement across a wide range of mean pressures. Two-level linear mixed effects analyses showed that Oscar 2 mean error reduced during vasopressor use by (-) 3.9 mmHg (95% CI -5.9, -1.9; P tension. In the Intensive Care Unit, the performance of one device, the Oscar 2, surpassed the others and fulfilled the AAMI protocol criteria for mean pressure measurement. This device is suitable for prehospital validation.

  13. Highly resolved HSQC experiments for the fast and accurate measurement of homonuclear and heteronuclear coupling constants

    Science.gov (United States)

    Souza, Alexandre A.; Gil, Roberto R.; Parella, Teodor

    2017-09-01

    A number of J-upscaled NMR experiments are currently available to measure coupling constants along the indirect F1 dimension of a 2D spectrum. A major drawback is the limited F1 digital resolution that requires long acquisition times in order to achieve reasonably accurate measures. Here is shown how high levels of F1 digital resolution in a multiple-purpose HSQC experiment can be easily achieved by implementing a general J/δ-scaling strategy. In particular, a set of new J-resolved HSQC experiments is presented for a faster and much more accurate J determination in small molecules. Several options and practical aspects are discussed and exemplified by measuring the magnitude and/or the sign of several homo- and heteronuclear coupling constants in one shot.

  14. More accurate systolic blood pressure measurement is required for improved hypertension management: a perspective.

    Science.gov (United States)

    Nitzan, Meir; Slotki, Itzchak; Shavit, Linda

    2017-01-01

    The commonly used techniques for systolic blood pressure (SBP) and diastolic blood pressure (DBP) measurement are the auscultatory Korotkoff-based sphygmomanometry and oscillometry. The former technique is relatively accurate but is limited to a physician's office because its automatic variant is subject to noise artifacts. Consequently, the Korotkoff-based measurement overestimates the blood pressure in some patients due to white coat effect, and because it is a single measurement, it cannot properly represent the variable blood pressure. Automatic oscillometry can be used at home by the patient and is preferred even in clinics. However, the technique's accuracy is low and errors of 10-15 mmHg are common. Recently, we have developed an automatic technique for SBP measurement, based on an arm pressure cuff and a finger photoplethysmographic probe. The technique was found to be significantly more accurate than oscillometry, and comparable to the Korotkoff-based technique, the reference-standard for non-invasive blood pressure measurements. The measurement of SBP is a mainstay for the diagnosis and follow-up of hypertension, which is a major risk factor for several adverse events, mainly cardiovascular. Lowering blood pressure evidently reduces the risk, but excessive lowering can result in hypotension and consequently hypoperfusion to vital organs, since blood pressure is the driving force for blood flow. Erroneous measurement by 10 mmHg can lead to a similar unintended reduction of SBP and may adversely affect patients treated to an SBP of 120-130 mmHg. In particular, in elderly patients, unintended excessive reduction of blood pressure due to inaccurate SBP measurement can result in cerebral hypoperfusion and consequent cognitive decline. By using a more accurate technique for automatic SBP measurement (such as the photoplethysmographic-based technique), the optimal blood pressure target can be achieved with lower risk for hypotension and its adverse events.

  15. Anthropometric measures are not accurate predictors of fat mass in ALS.

    Science.gov (United States)

    Ioannides, Zara A; Steyn, Frederik J; Henderson, Robert D; Mccombe, Pamela A; Ngo, Shyuan T

    2017-11-01

    Anthropometric measurements including body mass index (BMI) and body adiposity index (BAI) are widely employed as indicators of fat mass (FM). Metabolic abnormalities in amyotrophic lateral sclerosis (ALS) impact disease progression, therefore assessment of FM informs care. The aim of this study was to determine whether BMI and BAI are accurate predictors of FM in ALS. Methodology and main findings: BMI, BAI and percentage FM (determined by air displacement plethysmography; FM-ADP) were measured in control (n = 35) and ALS (n = 44) participants. While BMI and BAI correlated significantly with FM-ADP, neither index provided an accurate estimate of FM. In longitudinally assessed ALS participants (n = 29; ∼six-month repeat assessment interval), although a change in BMI (r 2  = 0.62 r = 0.79 p FM-ADP, the anthropometric measures did not consistently reflect increases or decreases observed in FM-ADP. Using FM-ADP as the standard, this study suggests that BMI and BAI are not accurate measures of FM in ALS. Furthermore, longitudinal assessments indicate that changes in BMI and BAI do not consistently reflect true changes of FM in ALS.

  16. New accurate measurements of neutron emission probabilities for relevant fission products

    Directory of Open Access Journals (Sweden)

    Agramunt J.

    2017-01-01

    Full Text Available We have performed new accurate measurements of the beta-delayed neutron emission probability for ten isotopes of the elements Y, Sb, Te and I. These are fission products that either have a significant contribution to the fraction of delayed neutrons in reactors or are relatively close to the path of the astrophysical r process. The measurements were performed with isotopically pure radioactive beams using a constant and high efficiency neutron counter and a low noise beta detector. Preliminary results are presented for six of the isotopes and compared with previous measurements and theoretical calculations.

  17. Comparisons of Vibrio fischeri, Photobacterium phosphoreum, and recombinant luminescent using Escherichia coli as BOD measurement.

    Science.gov (United States)

    Cheng, Chiu-Yu; Kuo, Jong-Tar; Lin, Yu-Cheng; Liao, Yi-Ru; Chung, Ying-Chien

    2010-01-01

    To shorten the time needed to measure biochemical oxygen demand (BOD) in water samples and to provide a rapid feedback of the real condition of water quality, we tested and evaluated the validity and reliability of luminescent bacteria Vibrio fischeri, Photobacterium phosphoreum, and recombinant Escherichia coli as potential indicators of BOD in the domestic wastewaters. The results indicate that the luminescence intensities of these strains are dependent on temperature, pH, and BOD concentration. In comparison to the standard BOD(5) method, the time needed for BOD measurement can be shortened by 90, 120, and 150 min when V. fischeri, P. phosphoreum, and recombinant E. coli, respectively, are used. Recombinant E. coli can be adapted to measure BOD in domestic wastewater containing a wide range of BOD concentrations, V. fischeri is not suitable for measuring diluted wastewater, and P. phosphoreum has only a limited application in measuring concentrated wastewater. To the best of our knowledge, this is the first report in which V. fischeri, P. phosphoreum, and recombinant luminescent E. coli are compared in terms of their potential in BOD measurement systems.

  18. Accurate microfour-point probe sheet resistance measurements on small samples

    DEFF Research Database (Denmark)

    Thorsteinsson, Sune; Wang, Fei; Petersen, Dirch Hjorth

    2009-01-01

    of a mirror plane on small samples with dimensions of a few times the probe pitch. We calculate theoretically the size of the “sweet spot,” where sufficiently accurate sheet resistances result and show that even for very small samples it is feasible to do correction free extraction of the sheet resistance......We show that accurate sheet resistance measurements on small samples may be performed using microfour-point probes without applying correction factors. Using dual configuration measurements, the sheet resistance may be extracted with high accuracy when the microfour-point probes are in proximity...... with sufficient accuracy. As an example, the sheet resistance of a 40 µm (50 µm) square sample may be characterized with an accuracy of 0.3% (0.1%) using a 10 µm pitch microfour-point probe and assuming a probe alignment accuracy of ±2.5 µm. ©2009 American Institute of Physics...

  19. Accurate acoustic power measurement for low-intensity focused ultrasound using focal axial vibration velocity

    Science.gov (United States)

    Tao, Chenyang; Guo, Gepu; Ma, Qingyu; Tu, Juan; Zhang, Dong; Hu, Jimin

    2017-07-01

    Low-intensity focused ultrasound is a form of therapy that can have reversible acoustothermal effects on biological tissue, depending on the exposure parameters. The acoustic power (AP) should be chosen with caution for the sake of safety. To recover the energy of counteracted radial vibrations at the focal point, an accurate AP measurement method using the focal axial vibration velocity (FAVV) is proposed in explicit formulae and is demonstrated experimentally using a laser vibrometer. The experimental APs for two transducers agree well with theoretical calculations and numerical simulations, showing that AP is proportional to the square of the FAVV, with a fixed power gain determined by the physical parameters of the transducers. The favorable results suggest that the FAVV can be used as a valuable parameter for non-contact AP measurement, providing a new strategy for accurate power control for low-intensity focused ultrasound in biomedical engineering.

  20. An accurate automated technique for quasi-optics measurement of the microwave diagnostics for fusion plasma

    Science.gov (United States)

    Hu, Jianqiang; Liu, Ahdi; Zhou, Chu; Zhang, Xiaohui; Wang, Mingyuan; Zhang, Jin; Feng, Xi; Li, Hong; Xie, Jinlin; Liu, Wandong; Yu, Changxuan

    2017-08-01

    A new integrated technique for fast and accurate measurement of the quasi-optics, especially for the microwave/millimeter wave diagnostic systems of fusion plasma, has been developed. Using the LabVIEW-based comprehensive scanning system, we can realize not only automatic but also fast and accurate measurement, which will help to eliminate the effects of temperature drift and standing wave/multi-reflection. With the Matlab-based asymmetric two-dimensional Gaussian fitting method, all the desired parameters of the microwave beam can be obtained. This technique can be used in the design and testing of microwave diagnostic systems such as reflectometers and the electron cyclotron emission imaging diagnostic systems of the Experimental Advanced Superconducting Tokamak.

  1. Precise and accurate measurements of strong-field photoionisation and a transferrable laser intensity calibration standard

    CERN Document Server

    Wallace, W C; Khurmi, C; U., Satya Sainadh; Calvert, J E; Laban, D E; Pullen, M G; Bartschat, K; Grum-Grzhimailo, A N; Wells, D; Quiney, H M; Tong, X M; Litvinyuk, I V; Sang, R T; Kielpinski, D

    2016-01-01

    Ionization of atoms and molecules in strong laser fields is a fundamental process in many fields of research, especially in the emerging field of attosecond science. So far, demonstrably accurate data have only been acquired for atomic hydrogen (H), a species that is accessible to few investigators. Here we present measurements of the ionization yield for argon, krypton, and xenon with percentlevel accuracy, calibrated using H, in a laser regime widely used in attosecond science. We derive a transferrable calibration standard for laser peak intensity, accurate to 1.3%, that is based on a simple reference curve. In addition, our measurements provide a much-needed benchmark for testing models of ionisation in noble-gas atoms, such as the widely employed single-active electron approximation.

  2. Are external knee load and EMG measures accurate indicators of internal knee contact forces during gait?

    Science.gov (United States)

    Meyer, Andrew J; D'Lima, Darryl D; Besier, Thor F; Lloyd, David G; Colwell, Clifford W; Fregly, Benjamin J

    2013-06-01

    Mechanical loading is believed to be a critical factor in the development and treatment of knee osteoarthritis. However, the contact forces to which the knee articular surfaces are subjected during daily activities cannot be measured clinically. Thus, the ability to predict internal knee contact forces accurately using external measures (i.e., external knee loads and muscle electromyographic [EMG] signals) would be clinically valuable. We quantified how well external knee load and EMG measures predict internal knee contact forces during gait. A single subject with a force-measuring tibial prosthesis and post-operative valgus alignment performed four gait patterns (normal, medial thrust, walking pole, and trunk sway) to induce a wide range of external and internal knee joint loads. Linear regression analyses were performed to assess how much of the variability in internal contact forces was accounted for by variability in the external measures. Though the different gait patterns successfully induced significant changes in the external and internal quantities, changes in external measures were generally weak indicators of changes in total, medial, and lateral contact force. Our results suggest that when total contact force may be changing, caution should be exercised when inferring changes in knee contact forces based on observed changes in external knee load and EMG measures. Advances in musculoskeletal modeling methods may be needed for accurate estimation of in vivo knee contact forces. Copyright © 2012 Orthopaedic Research Society.

  3. A Novel Multimode Waveguide Coupler for Accurate Power Measurement of Traveling Wave Tube Harmonic Frequencies

    Science.gov (United States)

    Wintucky, Edwin G.; Simons, Rainee N.

    2014-01-01

    This paper presents the design, fabrication and test results for a novel waveguide multimode directional coupler (MDC). The coupler fabricated from two dissimilar waveguides is capable of isolating the power at the second harmonic frequency from the fundamental power at the output port of a traveling-wave tube (TWT). In addition to accurate power measurements at harmonic frequencies, a potential application of the MDC is in the design of a beacon source for atmospheric propagation studies at millimeter-wave frequencies.

  4. Accurate Measurements of Aerosol Hygroscopic Growth over a Wide Range in Relative Humidity.

    Science.gov (United States)

    Rovelli, Grazia; Miles, Rachael E H; Reid, Jonathan P; Clegg, Simon L

    2016-06-30

    Using a comparative evaporation kinetics approach, we describe a new and accurate method for determining the equilibrium hygroscopic growth of aerosol droplets. The time-evolving size of an aqueous droplet, as it evaporates to a steady size and composition that is in equilibrium with the gas phase relative humidity, is used to determine the time-dependent mass flux of water, yielding information on the vapor pressure of water above the droplet surface at every instant in time. Accurate characterization of the gas phase relative humidity is provided from a control measurement of the evaporation profile of a droplet of know equilibrium properties, either a pure water droplet or a sodium chloride droplet. In combination, and by comparison with simulations that account for both the heat and mass transport governing the droplet evaporation kinetics, these measurements allow accurate retrieval of the equilibrium properties of the solution droplet (i.e., the variations with water activity in the mass fraction of solute, diameter growth factor, osmotic coefficient or number of water molecules per solute molecule). Hygroscopicity measurements can be made over a wide range in water activity (from >0.99 to, in principle, 0.9 and ∼±1% below 80% RH, and maximum uncertainties in diameter growth factor of ±0.7%. For all of the inorganic systems examined, the time-dependent data are consistent with large values of the mass accommodation (or evaporation) coefficient (>0.1).

  5. The preliminary exploration of 64-slice volume computed tomography in the accurate measurement of pleural effusion

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Zhi-Jun [Dept. of Radiology, North China Petroleum Bureau General Hospital, Renqiu, Hebei (China)], e-mail: Gzj3@163.com; Lin, Qiang [Dept. of Oncology, North China Petroleum Bureau General Hospital, Renqiu, Hebei (China); Liu, Hai-Tao [Dept. of General Surgery, North China Petroleum Bureau General Hospital, Renqiu, Hebei (China)] [and others])

    2013-09-15

    Background: Using computed tomography (CT) to rapidly and accurately quantify pleural effusion volume benefits medical and scientific research. However, the precise volume of pleural effusions still involves many challenges and currently does not have a recognized accurate measuring. Purpose: To explore the feasibility of using 64-slice CT volume-rendering technology to accurately measure pleural fluid volume and to then analyze the correlation between the volume of the free pleural effusion and the different diameters of the pleural effusion. Material and Methods: The 64-slice CT volume-rendering technique was used to measure and analyze three parts. First, the fluid volume of a self-made thoracic model was measured and compared with the actual injected volume. Second, the pleural effusion volume was measured before and after pleural fluid drainage in 25 patients, and the volume reduction was compared with the actual volume of the liquid extract. Finally, the free pleural effusion volume was measured in 26 patients to analyze the correlation between it and the diameter of the effusion, which was then used to calculate the regression equation. Results: After using the 64-slice CT volume-rendering technique to measure the fluid volume of the self-made thoracic model, the results were compared with the actual injection volume. No significant differences were found, P = 0.836. For the 25 patients with drained pleural effusions, the comparison of the reduction volume with the actual volume of the liquid extract revealed no significant differences, P = 0.989. The following linear regression equation was used to compare the pleural effusion volume (V) (measured by the CT volume-rendering technique) with the pleural effusion greatest depth (d): V = 158.16 X d - 116.01 (r = 0.91, P = 0.000). The following linear regression was used to compare the volume with the product of the pleural effusion diameters (l X h X d): V = 0.56 X (l X h X d) + 39.44 (r = 0.92, P = 0

  6. Accurate measurement of cortical bone elasticity tensor with resonant ultrasound spectroscopy.

    Science.gov (United States)

    Bernard, Simon; Grimal, Quentin; Laugier, Pascal

    2013-02-01

    Resonant ultrasound spectroscopy (RUS) allows to accurately characterize the complete set of elastic constants of an anisotropic material from a set of measured mechanical resonant frequencies of a specimen. This method does not suffer from the drawbacks and limitations of the conventional sound velocity approach, but has been reported to fail to measure bone because of its strong viscoelastic damping. In this study, we take advantage of recent developments of RUS to overcome this limitation. The frequency response of a human cortical bone specimen (about 5 × 7 × 7 mm(3)) was measured between 100 and 280 kHz. Despite an important overlapping of the resonant peaks 20 resonant frequencies could be retrieved by using a dedicated signal processing method. The experimental frequencies were progressively matched to the frequencies predicted by a model of the sample whose elastic constants were adjusted. The determined diagonal elastic constants were in good agreement with concurrent sound velocity measurements performed in the principal directions of the specimen. This study demonstrates that RUS is suitable for an accurate measurement of cortical bone anisotropic elasticity. In particular, precision of measured Young and shear moduli is about 0.5%. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Automatic emissive probe apparatus for accurate plasma and vacuum space potential measurements

    Science.gov (United States)

    Jianquan, LI; Wenqi, LU; Jun, XU; Fei, GAO; Younian, WANG

    2018-02-01

    We have developed an automatic emissive probe apparatus based on the improved inflection point method of the emissive probe for accurate measurements of both plasma potential and vacuum space potential. The apparatus consists of a computer controlled data acquisition card, a working circuit composed by a biasing unit and a heating unit, as well as an emissive probe. With the set parameters of the probe scanning bias, the probe heating current and the fitting range, the apparatus can automatically execute the improved inflection point method and give the measured result. The validity of the automatic emissive probe apparatus is demonstrated in a test measurement of vacuum potential distribution between two parallel plates, showing an excellent accuracy of 0.1 V. Plasma potential was also measured, exhibiting high efficiency and convenient use of the apparatus for space potential measurements.

  8. Assessment of air space size characteristics by intercept (chord) measurement: an accurate and efficient stereological approach.

    Science.gov (United States)

    Knudsen, Lars; Weibel, Ewald R; Gundersen, Hans Jørgen G; Weinstein, Felix V; Ochs, Matthias

    2010-02-01

    The mean linear intercept (chord) length (L(m)) is a useful parameter of peripheral lung structure as it describes the mean free distance in the air spaces. It is often misinterpreted as a measure of "alveolar size," and its estimation is fraught with a number of pitfalls. We present two methods for the accurate estimation of L(m): 1) the indirect method, which derives L(m) from the volume-to-surface ratio of air spaces estimated by point counting methods, and 2) the direct method, which uses a set of random intercepts and calculates L(m) from their frequency distribution, for which we introduce a new and accurate method. Both methods are efficient and, with proper precautions, unbiased. The meaning of L(m) is assessed in two different examples. In a physiological study, the effect of different inflation levels is studied, showing that L(m) critically depends on lung inflation. In an experimental study on emphysema-like changes in a genetic mouse model, the effect of heterogeneity of air space size is assessed; these results are obtained partly because of differences in lung volume due to altered recoil in the emphysematous lungs. In conclusion, although L(m) is not a robust parameter of internal lung structure because it crucially depends on lung volume, it is still a valid measure for which accurate and efficient methods are available that yield additional parameters such as size distribution or alveolar surface area.

  9. Polarization measurement of dielectronic recombination transitions in highly charged krypton ions

    CERN Document Server

    Shah, Chintan; Bernitt, Sven; Dobrodey, Stepan; Steinbrügge, René; Beilmann, Christian; Amaro, Pedro; Hu, Zhimin; Weber, Sebastian; Fritzsche, Stephan; Surzhykov, Andrey; López-Urrutia, José R Crespo; Tashenov, Stanislav

    2016-01-01

    We report linear polarization measurements of x rays emitted due to dielectronic recombination into highly charged krypton ions. The ions in the He-like through O-like charge states were populated in an electron beam ion trap with the electron beam energy adjusted to recombination resonances in order to produce $K\\alpha$ x rays. The x rays were detected with a newly developed Compton polarimeter using a beryllium scattering target and 12 silicon x-ray detector diodes sampling the azimuthal distribution of the scattered x rays. The extracted degrees of linear polarization of several dielectronic recombination transitions agree with results of relativistic distorted--wave calculations. We also demonstrate a high sensitivity of the polarization to the Breit interaction, which is remarkable for a medium-$Z$ element like krypton. The experimental results can be used for polarization diagnostics of hot astrophysical and laboratory fusion plasmas.

  10. No galaxy left behind: accurate measurements with the faintest objects in the Dark Energy Survey

    Science.gov (United States)

    Suchyta, E.; Huff, E. M.; Aleksić, J.; Melchior, P.; Jouvel, S.; MacCrann, N.; Ross, A. J.; Crocce, M.; Gaztanaga, E.; Honscheid, K.; Leistedt, B.; Peiris, H. V.; Rykoff, E. S.; Sheldon, E.; Abbott, T.; Abdalla, F. B.; Allam, S.; Banerji, M.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Eifler, T. F.; Estrada, J.; Evrard, A. E.; Flaugher, B.; Fosalba, P.; Frieman, J.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; James, D. J.; Jarvis, M.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Lima, M.; Maia, M. A. G.; March, M.; Marshall, J. L.; Miller, C. J.; Miquel, R.; Neilsen, E.; Nichol, R. C.; Nord, B.; Ogando, R.; Percival, W. J.; Reil, K.; Roodman, A.; Sako, M.; Sanchez, E.; Scarpine, V.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Swanson, M. E. C.; Tarle, G.; Thaler, J.; Thomas, D.; Vikram, V.; Walker, A. R.; Wechsler, R. H.; Zhang, Y.; DES Collaboration

    2016-03-01

    Accurate statistical measurement with large imaging surveys has traditionally required throwing away a sizable fraction of the data. This is because most measurements have relied on selecting nearly complete samples, where variations in the composition of the galaxy population with seeing, depth, or other survey characteristics are small. We introduce a new measurement method that aims to minimize this wastage, allowing precision measurement for any class of detectable stars or galaxies. We have implemented our proposal in BALROG, software which embeds fake objects in real imaging to accurately characterize measurement biases. We demonstrate this technique with an angular clustering measurement using Dark Energy Survey (DES) data. We first show that recovery of our injected galaxies depends on a variety of survey characteristics in the same way as the real data. We then construct a flux-limited sample of the faintest galaxies in DES, chosen specifically for their sensitivity to depth and seeing variations. Using the synthetic galaxies as randoms in the Landy-Szalay estimator suppresses the effects of variable survey selection by at least two orders of magnitude. With this correction, our measured angular clustering is found to be in excellent agreement with that of a matched sample from much deeper, higher resolution space-based Cosmological Evolution Survey (COSMOS) imaging; over angular scales of 0.004° < θ < 0.2°, we find a best-fitting scaling amplitude between the DES and COSMOS measurements of 1.00 ± 0.09. We expect this methodology to be broadly useful for extending measurements' statistical reach in a variety of upcoming imaging surveys.

  11. Rapid yet accurate measurement of mass diffusion coefficients by phase shifting interferometer

    CERN Document Server

    Guo Zhi Xiong; Komiya, A

    1999-01-01

    The technique of using a phase-shifting interferometer is applied to the study of diffusion in transparent liquid mixtures. A quick method is proposed for determining the diffusion coefficient from the measurements of the location of fringes on a grey level picture. The measurement time is very short (within 100 s) and a very small transient diffusion field can be observed and recorded accurately with a rate of 30 frames per second. The measurement can be completed using less than 0.12 cc of solutions. The influence of gravity on the measurement of the diffusion coefficient is eliminated in the present method. Results on NaCl-water diffusion systems are presented and compared with the reference data. (author)

  12. Barriers to accurately measuring patients' dietary intake in hospitals using the visual estimation method.

    Science.gov (United States)

    Kawasaki, Yui; Kojima, Yui; Akamatsu, Rie

    2016-10-10

    Purpose Visual estimation, an easy-to-perform technique, is commonly used in hospitals to assess dietary intake in patients. The authors performed a qualitative study where the authors interviewed nurses and dietitians about their perceptions of barriers to accurately measuring patients' dietary intake in hospitals using the visual estimation method. The paper aims to discuss these issues. Design/methodology/approach Ten dietitians and ten clinical nurses responded to 30-minute individual interviews in Tokyo, Japan, in September 2014. Each interview was conducted using a common protocol of open-ended questions focusing on the challenges of the visual estimation method and barriers to accurately measuring patients' dietary intake as part of their routine work. The tape-recorded interviews were transcribed and analyzed based on grounded theory. Findings Five main categories emerged: hospitals, meals, colleagues, raters, and patients. Various individual barriers such as skill, attitude, knowledge, and others that had not been considered in previous studies also emerged. External barriers that were out of the raters' control, such as shortage of time, human resources, financial ability, and others, emerged from the "hospitals" category. Research limitations/implications Research participants were all females and many of them had less than ten years of experience. Practical implications In addition to standardizing the visual estimation process, medical staff need to overcome various other internal and external barriers to accurate measurements. Originality/value This is the first study to articulate some important barriers that influence reliability and validity when measuring patients' dietary intake by visual estimation methods in typical clinical settings.

  13. Measuring physical inactivity: do current measures provide an accurate view of "sedentary" video game time?

    Science.gov (United States)

    Fullerton, Simon; Taylor, Anne W; Dal Grande, Eleonora; Berry, Narelle

    2014-01-01

    Measures of screen time are often used to assess sedentary behaviour. Participation in activity-based video games (exergames) can contribute to estimates of screen time, as current practices of measuring it do not consider the growing evidence that playing exergames can provide light to moderate levels of physical activity. This study aimed to determine what proportion of time spent playing video games was actually spent playing exergames. Data were collected via a cross-sectional telephone survey in South Australia. Participants aged 18 years and above (n = 2026) were asked about their video game habits, as well as demographic and socioeconomic factors. In cases where children were in the household, the video game habits of a randomly selected child were also questioned. Overall, 31.3% of adults and 79.9% of children spend at least some time playing video games. Of these, 24.1% of adults and 42.1% of children play exergames, with these types of games accounting for a third of all time that adults spend playing video games and nearly 20% of children's video game time. A substantial proportion of time that would usually be classified as "sedentary" may actually be spent participating in light to moderate physical activity.

  14. More accurate systolic blood pressure measurement is required for improved hypertension management: a perspective

    Directory of Open Access Journals (Sweden)

    Nitzan M

    2017-07-01

    Full Text Available Meir Nitzan,1 Itzchak Slotki,2 Linda Shavit2 1Department of Applied Physics/Electro-Optics, Jerusalem College of Technology, 2Department of Nephrology, Shaare Zedek Medical Center, Jerusalem, Israel Abstract: The commonly used techniques for systolic blood pressure (SBP and diastolic blood pressure (DBP measurement are the auscultatory Korotkoff-based sphygmomanometry and oscillometry. The former technique is relatively accurate but is limited to a physician’s office because its automatic variant is subject to noise artifacts. Consequently, the Korotkoff-based measurement overestimates the blood pressure in some patients due to white coat effect, and because it is a single measurement, it cannot properly represent the variable blood pressure. Automatic oscillometry can be used at home by the patient and is preferred even in clinics. However, the technique’s accuracy is low and errors of 10–15 mmHg are common. Recently, we have developed an automatic technique for SBP measurement, based on an arm pressure cuff and a finger photoplethysmographic probe. The technique was found to be significantly more accurate than oscillometry, and comparable to the Korotkoff-based technique, the reference-standard for non-invasive blood pressure measurements. The measurement of SBP is a mainstay for the diagnosis and follow-up of hypertension, which is a major risk factor for several adverse events, mainly cardiovascular. Lowering blood pressure evidently reduces the risk, but excessive lowering can result in hypotension and consequently hypoperfusion to vital organs, since blood pressure is the driving force for blood flow. Erroneous measurement by 10 mmHg can lead to a similar unintended reduction of SBP and may adversely affect patients treated to an SBP of 120–130 mmHg. In particular, in elderly patients, unintended excessive reduction of blood pressure due to inaccurate SBP measurement can result in cerebral hypoperfusion and consequent cognitive

  15. Accurate lung volume measurements in vitro using a novel inert gas washout method suitable for infants.

    Science.gov (United States)

    Shawcross, Anna; Murray, Clare S; Goddard, Nicholas; Gupta, Ruchi; Watson, Stuart; Horsley, Alexander

    2016-05-01

    Multiple breath washout (MBW) in infants presents a number of technical challenges. Conventional MBW is based on simultaneous measurement of flow and gas concentrations. These two signals are aligned and combined to derive expired gas volumes from which lung volumes and measures of ventilation inhomogeneity are calculated. Accuracy of measurement becomes increasingly vulnerable to errors in gas signal alignment at fast respiratory rates. In this paper we describe an alternative method of performing MBW in infants. Expired gas is collected and analyzed to derive functional residual capacity (FRC) and lung clearance index (LCI). This eliminates the need for simultaneous measurement of flow, and integration of flow and gas signals, and significantly reduces deadspace. A highly accurate lung model incorporating BTPS conditions was used to generate realistic infant breathing parameters: FRC of 100-250 mls with respiratory rate of 20-60 min(-1) . In vitro accuracy of FRC measurement using the novel MBW method was assessed using the model. Overall mean error (standard deviation) of FRC measurement was -1.0 (3.3)% with 90% of tests falling within ±5%. FRC measurement using the novel method has superior accuracy in vitro than previously described systems. By uncoupling the measurement of gas volumes from real-time flow and gas measurement, this system offers an alternative method of MBW which is well suited to infants. © 2015 Wiley Periodicals, Inc.

  16. Combining MFD and PIE for accurate single-pair Förster resonance energy transfer measurements.

    Science.gov (United States)

    Kudryavtsev, Volodymyr; Sikor, Martin; Kalinin, Stanislav; Mokranjac, Dejana; Seidel, Claus A M; Lamb, Don C

    2012-03-01

    Single-pair Förster resonance energy transfer (spFRET) experiments using single-molecule burst analysis on a confocal microscope are an ideal tool to measure inter- and intramolecular distances and dynamics on the nanoscale. Different techniques have been developed to maximize the amount of information available in spFRET burst analysis experiments. Multiparameter fluorescence detection (MFD) is used to monitor a variety of fluorescence parameters simultaneously and pulsed interleaved excitation (PIE) employs direct excitation of the acceptor to probe its presence and photoactivity. To calculate accurate FRET efficiencies from spFRET experiments with MFD or PIE, several calibration measurements are usually required. Herein, we demonstrate that by combining MFD with PIE information regarding all calibration factors as well as an accurate determination of spFRET histograms can be performed in a single measurement. In addition, the quality of overlap of the different detection volumes as well as the detection of acceptor photophysics can be investigated with MFD-PIE. Bursts containing acceptor photobleaching can be identified and excluded from further investigation while bursts that contain FRET dynamics are unaffected by this analysis. We have employed MFD-PIE to accurately analyze the effects of nucleotides and substrate on the interdomain separation in DnaK, the major bacterial heat shock protein 70 (Hsp70). The interdomain distance increases from 47 Å in the ATP-bound state to 84 Å in the ADP-bound state and slightly contracts to 77 Å when a substrate is bound. This is in contrast to what was observed for the mitochondrial member of the Hsp70s, Ssc1, supporting the notion of evolutionary specialization of Hsp70s for different cellular functions in different organisms and cell organelles. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Cost-effective and accurate method of measuring fetal fraction using SNP imputation.

    Science.gov (United States)

    Kim, Minjeong; Kim, Jai-Hoon; Kim, Kangseok; Kim, Sunshin

    2017-11-08

    With the discovery of cell-free fetal DNA in maternal blood, the demand for non-invasive prenatal testing (NIPT) has been increasing. To obtain reliable NIPT results, it is important to accurately estimate the fetal fraction. In this study, we propose an accurate and cost-effective method for measuring fetal fractions using single-nucleotide polymorphisms (SNPs). A total of 84 samples were sequenced via semiconductor sequencing using a 0.3x sequencing coverage. SNPs were genotyped to estimate the fetal fraction. Approximately 900,000 SNPs were genotyped, and 250,000 of these SNPs matched the semiconductor sequencing results. We performed SNP imputation (1000Genome phase3 and HRC v1.1 reference panel) to increase the number of SNPs. The correlation coefficients (R2) of the fetal fraction estimated using the ratio of non-maternal alleles when coverage was reduced to 0.01 following SNP imputation were 0.93 (HRC v1.1 reference panel) and 0.90 (1000GP3 reference panel). An R2 of 0.72 was found at 0.01x sequencing coverage with no imputation performed. We developed an accurate method to measure fetal fraction using SNP imputation, showing cost-effectiveness by using different commercially available SNP chips and lowering the coverage. We also showed that semiconductor sequencing, which is an inexpensive option, was useful for measuring fetal fraction. python source code and guidelines can be found at https://github.com/KMJ403/fetalfraction-SNPimpute. kangskim@ajou.ac.kr, sunshinkim3@gmail.com. Supplementary data are available at Bioinformatics online.

  18. A temperature compensated dielectric test cell for accurately measuring the complex permittivity of liquids

    Science.gov (United States)

    Risos, Alex; Long, Nicholas; Gouws, Gideon

    2017-10-01

    A measurement of the complex permittivity, ɛr, of a liquid can give valuable information about the molecular polarizability and dielectric losses. This can be obtained by means of an impedance measurement using a parallel plate test cell. However, highly accurate and precise measurements are challenging, in particular when measuring as a function of temperature. Thermal expansion affects the geometry of a test cell and thus the measured capacitance from which ɛr is calculated. In this paper, a broadband four-terminal dielectric test cell is presented that is insensitive to temperature fluctuations. This was achieved by means of a cell geometry exploiting the thermal expansion coefficient of different materials. Experimental measurements on the manufactured cell yielded a stable capacitance of 35.322 ± 0.001 pF across 20 °C-90 °C. The capacitance stayed within ±0.01 pF over multiple experimental cycles of cleaning and assembly. A finite element modeling showed a theoretical accuracy in measuring ɛr better than 99.995%. The measured ɛr values for a number of standard liquids showed an agreement of 99.7% compared to literature values.

  19. Easy Leaf Area: Automated Digital Image Analysis for Rapid and Accurate Measurement of Leaf Area

    Directory of Open Access Journals (Sweden)

    Hsien Ming Easlon

    2014-07-01

    Full Text Available Premise of the study: Measurement of leaf areas from digital photographs has traditionally required significant user input unless backgrounds are carefully masked. Easy Leaf Area was developed to batch process hundreds of Arabidopsis rosette images in minutes, removing background artifacts and saving results to a spreadsheet-ready CSV file. Methods and Results: Easy Leaf Area uses the color ratios of each pixel to distinguish leaves and calibration areas from their background and compares leaf pixel counts to a red calibration area to eliminate the need for camera distance calculations or manual ruler scale measurement that other software methods typically require. Leaf areas estimated by this software from images taken with a camera phone were more accurate than ImageJ estimates from flatbed scanner images. Conclusions: Easy Leaf Area provides an easy-to-use method for rapid measurement of leaf area and nondestructive estimation of canopy area from digital images.

  20. Geometric optimisation of an accurate cosine correcting optic fibre coupler for solar spectral measurement

    Science.gov (United States)

    Cahuantzi, Roberto; Buckley, Alastair

    2017-09-01

    Making accurate and reliable measurements of solar irradiance is important for understanding performance in the photovoltaic energy sector. In this paper, we present design details and performance of a number of fibre optic couplers for use in irradiance measurement systems employing remote light sensors applicable for either spectrally resolved or broadband measurement. The angular and spectral characteristics of different coupler designs are characterised and compared with existing state-of-the-art commercial technology. The new coupler designs are fabricated from polytetrafluorethylene (PTFE) rods and operate through forward scattering of incident sunlight on the front surfaces of the structure into an optic fibre located in a cavity to the rear of the structure. The PTFE couplers exhibit up to 4.8% variation in scattered transmission intensity between 425 nm and 700 nm and show minimal specular reflection, making the designs accurate and reliable over the visible region. Through careful geometric optimization near perfect cosine dependence on the angular response of the coupler can be achieved. The PTFE designs represent a significant improvement over the state of the art with less than 0.01% error compared with ideal cosine response for angles of incidence up to 50°.

  1. Comparison of thermistor linearization techniques for accurate temperature measurement in phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Stankovic, S B; Kyriacou, P A, E-mail: p.kyriacou@city.ac.uk [School of Engineering and Mathematical Sciences, City University London, Northampton Square, London EC1V 0HB (United Kingdom)

    2011-08-17

    Alternate energy technologies are developing rapidly in the recent years. A significant part of this trend is the development of different phase change materials (PCMs). Proper utilization of PCMs requires accurate thermal characterization. There are several methodologies used in this field. This paper stresses the importance of accurate temperature measurements during the implementation of T-history method. Since the temperature sensor size is also important thermistors have been selected as the sensing modality. Two thermistor linearization techniques, one based on Wheatstone bridge and the other based on simple serial-parallel resistor connection, are compared in terms of achievable temperature accuracy through consideration of both, nonlinearity and self-heating errors. Proper calibration was performed before T-history measurement of RT21 (RUBITHERM (registered) GmbH) PCM. Measurement results suggest that the utilization of serial-parallel resistor connection gives better accuracy (less than {+-}0.1 deg. C) in comparison with the Wheatstone bridge based configuration (up to {+-}1.5 deg. C).

  2. Accurate Measurements of the Dielectric Constant of Seawater at L Band

    Science.gov (United States)

    Lang, Roger; Zhou, Yiwen; Utku, Cuneyt; Le Vine, David

    2016-01-01

    This paper describes measurements of the dielectric constant of seawater at a frequency of 1.413 GHz, the center of the protected band (i.e., passive use only) used in the measurement of sea surface salinity from space. The objective of the measurements is to accurately determine the complex dielectric constant of seawater as a function of salinity and temperature. A resonant cylindrical microwave cavity in transmission mode has been employed to make the measurements. The measurements are made using standard seawater at salinities of 30, 33, 35, and 38 practical salinity units over a range of temperatures from 0 degree C to 35 degree C in 5 degree C intervals. Repeated measurements have been made at each temperature and salinity. Mean values and standard deviations are then computed. The total error budget indicates that the real and imaginary parts of the dielectric constant have a combined standard uncertainty of about 0.3 over the range of salinities and temperatures considered. The measurements are compared with the dielectric constants obtained from the model functions of Klein and Swift and those of Meissner and Wentz. The biggest differences occur at low and high temperatures.

  3. Accurate Measurements of Aircraft Engine Soot Emissions Using a CAPS PMssa Monitor

    Science.gov (United States)

    Onasch, Timothy; Thompson, Kevin; Renbaum-Wolff, Lindsay; Smallwood, Greg; Make-Lye, Richard; Freedman, Andrew

    2016-04-01

    We present results of aircraft engine soot emissions measurements during the VARIAnT2 campaign using CAPS PMssa monitors. VARIAnT2, an aircraft engine non-volatile particulate matter (nvPM) emissions field campaign, was focused on understanding the variability in nvPM mass measurements using different measurement techniques and accounting for possible nvPM sampling system losses. The CAPS PMssa monitor accurately measures both the optical extinction and scattering (and thus single scattering albedo and absorption) of an extracted sample using the same sample volume for both measurements with a time resolution of 1 second and sensitivity of better than 1 Mm-1. Absorption is obtained by subtracting the scattering signal from the total extinction. Given that the single scattering albedo of the particulates emitted from the aircraft engine measured at both 630 and 660 nm was on the order of 0.1, any inaccuracy in the scattering measurement has little impact on the accuracy of the ddetermined absorption coefficient. The absorption is converted into nvPM mass using a documented Mass Absorption Coefficient (MAC). Results of soot emission indices (mass soot emitted per mass of fuel consumed) for a turbojet engine as a function of engine power will be presented and compared to results obtained using an EC/OC monitor.

  4. Measuring and managing ratio compression for accurate iTRAQ/TMT quantification.

    Science.gov (United States)

    Savitski, Mikhail M; Mathieson, Toby; Zinn, Nico; Sweetman, Gavain; Doce, Carola; Becher, Isabelle; Pachl, Fiona; Kuster, Bernhard; Bantscheff, Marcus

    2013-08-02

    Isobaric mass tagging (e.g., TMT and iTRAQ) is a precise and sensitive multiplexed peptide/protein quantification technique in mass spectrometry. However, accurate quantification of complex proteomic samples is impaired by cofragmentation of peptides, leading to systematic underestimation of quantitative ratios. Label-free quantification strategies do not suffer from such an accuracy bias but cannot be multiplexed and are less precise. Here, we compared protein quantification results obtained with these methods for a chemoproteomic competition binding experiment and evaluated the utility of measures of spectrum purity in survey spectra for estimating the impact of cofragmentation on measured TMT-ratios. While applying stringent interference filters enables substantially more accurate TMT quantification, this came at the expense of 30%-60% fewer proteins quantified. We devised an algorithm that corrects experimental TMT ratios on the basis of determined peptide interference levels. The quantification accuracy achieved with this correction was comparable to that obtained with stringent spectrum filters but limited the loss in coverage to <10%. The generic applicability of the fold change correction algorithm was further demonstrated by spiking of chemoproteomics samples into excess amounts of E. coli tryptic digests.

  5. Accurate Estimation of Low Fundamental Frequencies from Real-Valued Measurements

    DEFF Research Database (Denmark)

    Christensen, Mads Græsbøll

    2013-01-01

    In this paper, the difficult problem of estimating low fundamental frequencies from real-valued measurements is addressed. The methods commonly employed do not take the phenomena encountered in this scenario into account and thus fail to deliver accurate estimates. The reason for this is that the......In this paper, the difficult problem of estimating low fundamental frequencies from real-valued measurements is addressed. The methods commonly employed do not take the phenomena encountered in this scenario into account and thus fail to deliver accurate estimates. The reason...... for this is that they employ asymptotic approximations that are violated when the harmonics are not well-separated in frequency, something that happens when the observed signal is real-valued and the fundamental frequency is low. To mitigate this, we analyze the problem and present some exact fundamental frequency estimators...... that are aimed at solving this problem. These esti- mators are based on the principles of nonlinear least-squares, harmonic fitting, optimal filtering, subspace orthogonality, and shift-invariance, and they all reduce to already published methods for a high number of observations. In experiments, the methods...

  6. [Preliminary reports of noninvasive accurate method to measure pulmonary vascular capacity in normal volunteers].

    Science.gov (United States)

    Sun, Xing-guo; Mao, Song-shou; Budoff, M J; Stringer, W W; Cheng, Xian-sheng

    2015-07-01

    Because the traditional loop of breathing control and regulation effect on blood circulation, there was rare study of pulmonary vein capacity. We need a noninvasive and accurate pulmonary vascular capacity measurement and analysis method. Twelve normal volunteers were performed a total lung CT scan, image data analysis processing by computer software, the whole lungs from the apex to the base of lung with 40-50 layers by hand-cut, the connection between adjacent layers automatically by a computer simulation, the full pulmonary vascular (≥ 0.6 mm) were treated by high-accuracy three-dimensional imaging technology after removing the interference, and then calculate the whole lung and pulmonary vascular. The whole lung of the 12 normal volunteers from the apex to the base of lung CT scan image layers was 530 ± 98 (range, 431-841). The total capacity of lung and pulmonary vascular blood was 3705 ± 857 (range, 2398-5383) ml, and the total volume of the pulmonary vascular blood was 125 ± 32 (range, 94-201) ml. The pulmonary vein vascular blood volume was 63 ± 16 (range, 47-100) ml. The method of measuring the three-dimensional imaging of pulmonary vascular capacity by analyzing lung CT scan data is available and accurate.

  7. Accurate Measurement of the in vivo Ammonium Concentration in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Hugo F. Cueto-Rojas

    2016-04-01

    Full Text Available Ammonium (NH4+ is the most common N-source for yeast fermentations, and N-limitation is frequently applied to reduce growth and increase product yields. While there is significant molecular knowledge on NH4+ transport and assimilation, there have been few attempts to measure the in vivo concentration of this metabolite. In this article, we present a sensitive and accurate analytical method to quantify the in vivo intracellular ammonium concentration in Saccharomyces cerevisiae based on standard rapid sampling and metabolomics techniques. The method validation experiments required the development of a proper sample processing protocol to minimize ammonium production/consumption during biomass extraction by assessing the impact of amino acid degradation—an element that is often overlooked. The resulting cold chloroform metabolite extraction method, together with quantification using ultra high performance liquid chromatography-isotope dilution mass spectrometry (UHPLC-IDMS, was not only more sensitive than most of the existing methods but also more accurate than methods that use electrodes, enzymatic reactions, or boiling water or boiling ethanol biomass extraction because it minimized ammonium consumption/production during sampling processing and interference from other metabolites in the quantification of intracellular ammonium. Finally, our validation experiments showed that other metabolites such as pyruvate or 2-oxoglutarate (αKG need to be extracted with cold chloroform to avoid measurements being biased by the degradation of other metabolites (e.g., amino acids.

  8. Rapid and accurate biofuel moisture content gauging using magnetic resonance measurement technology

    Energy Technology Data Exchange (ETDEWEB)

    Jaervinen, T.

    2013-04-15

    Biomass is extensively utilised in energy production and as a raw material, such as for the production of liquid biofuels. All those processes will benefit if the moisture content of bio material is known in advance as accurately as possible under transient circumstances. Biofuel trade is increasingly based on the calorific value of fuels. In the first step, this also increases the need for rapid and accurate moisture content determination. During the last few years, large biofuel standardisation has been implemented, emphasising biofuel quality control at all stages of the utilisation chain. In principle, the moisture instrumental measurement can be utilised by many technologies and procedures. Typical techniques are infrared, radiofrequency, microwave, radiometric, electrical conductivity, capacitance, and impedance. Nuclear magnetic resonance (MR) and thermal neutron absorption are also applied. The MR measurement principle has been known and utilised already since the early 1950s. It has become the basic instrumental analysis tool in chemistry. It is also well-known as a very accurate method for analysing most compounds, especially substances containing hydrogen. The utilisation of MR metering is expanded extensively to medical diagnostics as a form of magnetic resonance imaging (MRI). Because of the precision of the MR principle, there have for a long time been efforts to apply it in new and different areas, and to make more user-friendly, smaller, and even portable devices. Such a device was designed by Vaisala a few years ago. VTT has utilised Vaisala's MR prototype for approximately one year for moisture content measurement of different biofuels. The first step in the use of an MR device for moisture determination was the definition of its measurement accuracy compared to the standard method (EN 14774). Those tests proved that the absolute precision seems to be comparable to the standard moisture content measurement method. It was also found out that

  9. ACCURATE: Greenhouse Gas Profiles Retrieval from Combined IR-Laser and Microwave Occultation Measurements

    Science.gov (United States)

    Proschek, Veronika; Kirchengast, Gottfried; Schweitzer, Susanne; Fritzer, Johannes

    2010-05-01

    The new climate satellite concept ACCURATE (Atmospheric Climate and Chemistry in the UTLS Region And climate Trends Explorer) enables simultaneous measurement of profiles of greenhouse gases, isotopes, wind and thermodynamic variables from Low Earth Orbit (LEO) satellites. The measurement principle applied is a combination of the novel LEO-LEO infrared laser occultation (LIO) technique and the already better studied LEO-LEO microwave occultation (LMO) technique. Resulting occultation events are evenly distributed around the world, have high vertical resolution and accuracy and are stable over long time periods. The LIO uses near-monochromatic signals in the short-wave infrared range (~2-2.5 μm for ACCURATE). These signals are absorbed by various trace species in the Earth's atmosphere. Profiles of the concentration of the absorbing species can be derived from signal transmission measurements. Accurately known temperature, pressure and humidity profiles derived from simultaneously measured LMO signals are essential pre-information for the retrieval of the trace species profiles. These LMO signals lie in the microwave band region from 17-23 GHz and, optionally, 178-195 GHz. The current ACCURATE mission design is arranged for the measurement of six greenhouse gases (GHG) (H2O, CO2, CH4, N2O, O3, CO) and four isotopes (13CO2, C18OO, HDO, H218O), with focus on the upper troposphere/lower stratosphere region (UTLS, 5-35 km). Wind speed in line-of-sight can be derived from a line-symmetric transmission difference which is caused by wind-induced Doppler shift. By-products are information on cloud layering, aerosol extinction, and scintillation strength. We introduce the methodology to retrieve GHG profiles from quasi-realistic forward-simulated intensities of LIO signals and thermodynamic profiles retrieved in a preceding step from LMO signals. Key of the retrieval methodology is the differencing of two LIO transmission signals, one being GHG sensitive on a target

  10. Highly accurate thickness measurement of multi-layered automotive paints using terahertz technology

    Science.gov (United States)

    Krimi, Soufiene; Klier, Jens; Jonuscheit, Joachim; von Freymann, Georg; Urbansky, Ralph; Beigang, René

    2016-07-01

    In this contribution, we present a highly accurate approach for thickness measurements of multi-layered automotive paints using terahertz time domain spectroscopy in reflection geometry. The proposed method combines the benefits of a model-based material parameters extraction method to calibrate the paint coatings, a generalized Rouard's method to simulate the terahertz radiation behavior within arbitrary thin films, and the robustness of a powerful evolutionary optimization algorithm to increase the sensitivity of the minimum thickness measurement limit. Within the framework of this work, a self-calibration model is introduced, which takes into consideration the real industrial challenges such as the effect of wet-on-wet spray in the painting process.

  11. A solution for measuring accurate reaction time to visual stimuli realized with a programmable microcontroller.

    Science.gov (United States)

    Ohyanagi, Toshio; Sengoku, Yasuhito

    2010-02-01

    This article presents a new solution for measuring accurate reaction time (SMART) to visual stimuli. The SMART is a USB device realized with a Cypress Programmable System-on-Chip (PSoC) mixed-signal array programmable microcontroller. A brief overview of the hardware and firmware of the PSoC is provided, together with the results of three experiments. In Experiment 1, we investigated the timing accuracy of the SMART in measuring reaction time (RT) under different conditions of operating systems (OSs; Windows XP or Vista) and monitor displays (a CRT or an LCD). The results indicated that the timing error in measuring RT by the SMART was less than 2 msec, on average, under all combinations of OS and display and that the SMART was tolerant to jitter and noise. In Experiment 2, we tested the SMART with 8 participants. The results indicated that there was no significant difference among RTs obtained with the SMART under the different conditions of OS and display. In Experiment 3, we used Microsoft (MS) PowerPoint to present visual stimuli on the display. We found no significant difference in RTs obtained using MS DirectX technology versus using the PowerPoint file with the SMART. We are certain that the SMART is a simple and practical solution for measuring RTs accurately. Although there are some restrictions in using the SMART with RT paradigms, the SMART is capable of providing both researchers and health professionals working in clinical settings with new ways of using RT paradigms in their work.

  12. Recombination in the 5' leader of murine leukemia virus is accurate and influenced by sequence identity with a strong bias toward the kissing-loop dimerization region

    DEFF Research Database (Denmark)

    Mikkelsen, J G; Lund, Anders Henrik; Duch, M

    1998-01-01

    Retroviral recombination occurs frequently during reverse transcription of the dimeric RNA genome. By a forced recombination approach based on the transduction of Akv murine leukemia virus vectors harboring a primer binding site knockout mutation and the entire 5' untranslated region, we studied...... facilitate template switching. We discuss the putative role of the dimerization domain in the overall structure of the reverse-transcribed RNA dimer and note that related mechanisms of template switching may be found in remote RNA viruses....

  13. Modified AC Wheatstone Bridge Network for Accurate Measurement of Pressure Using Strain Gauge Type Pressure Sensor

    Directory of Open Access Journals (Sweden)

    Subrata CHATTOPADHYAY

    2012-01-01

    Full Text Available In order to achieve high quality of products at lesser cost, accurate measurement of different process variables is of vital importance in any industry. There are different well-established techniques of measurement and control instrumentations of these variables. In the resistive transducer like strain gauge, the small resistance generally changes linearly with a process variable like pressure but their measurement by usual AC Wheatstone bridge circuit may suffer from errors due to the effect of stray capacitance between bridge nodal points and ground and stray inductance on the strain gauge grid respectively. Though the conventional Wagner-Earth technique may be used to reduced the error but not suitable for continuous measurement. In the present paper, a modified operational amplifier based AC Wheatstone bridge measurement technique has been proposed in which the effect of stray capacitance and inductance is minimized. This bridge performance has been studied experimentally with the strain gauge type pressure transducer. The linear characteristics over a wide range of pressure with good repeatability, linearity and variable sensitivity have been described.

  14. Accurate and fast 3D surface measurement with temporal-spatial binary encoding structured illumination.

    Science.gov (United States)

    Zhu, Jiangping; Zhou, Pei; Su, Xianyu; You, Zhisheng

    2016-12-12

    Balancing the accuracy and speed for 3D surface measurement of object is crucial in many important applications. Binary encoding pattern utilizing the high-speed image switching rate of digital mirror device (DMD)-based projector could be used as the candidate for fast even high-speed 3D measurement, but current most schemes only enable the measurement speed, which limit their application scopes. In this paper, we present a binary encoding method and develop an experimental system aiming to solve such a situation. Our approach encodes one computer-generated standard 8 bit sinusoidal fringe pattern into multiple binary patterns (sequence) with designed temporal-spatial binary encoding tactics. The binary pattern sequence is then high-speed and in-focus projected onto the surface of tested object, and then captured by means of temporal-integration imaging to form one sinusoidal fringe image. Further the combination of phase-shifting technique and temporal phase unwrapping algorithm leads to fast and accurate 3D measurement. The systematic accuracy better than 0.08mm is achievable. The measurement results with mask and palm are given to confirm the feasibility.

  15. Explicit Knowledge of the Spanish Subjunctive and Accurate Use in Discrete-Point, Oral Production, and Written Production Measures

    National Research Council Canada - National Science Library

    Xavier Gutiérrez

    2017-01-01

    ...). The goal of this study was to examine whether explicit knowledge about the Spanish subjunctive is related to using this structure accurately in discrete-point measures, as well as in measures of oral...

  16. Smart density: a more accurate method of measuring rural residential density for health-related research

    Directory of Open Access Journals (Sweden)

    Gibson Lucinda

    2010-02-01

    Full Text Available Abstract Background Studies involving the built environment have typically relied on US Census data to measure residential density. However, census geographic units are often unsuited to health-related research, especially in rural areas where development is clustered and discontinuous. Objective We evaluated the accuracy of both standard census methods and alternative GIS-based methods to measure rural density. Methods We compared residential density (units/acre in 335 Vermont school neighborhoods using conventional census geographic units (tract, block group and block with two GIS buffer measures: a 1-kilometer (km circle around the school and a 1-km circle intersected with a 100-meter (m road-network buffer. The accuracy of each method was validated against the actual residential density for each neighborhood based on the Vermont e911 database, which provides an exact geo-location for all residential structures in the state. Results Standard census measures underestimate residential density in rural areas. In addition, the degree of error is inconsistent so even the relative rank of neighborhood densities varies across census measures. Census measures explain only 61% to 66% of the variation in actual residential density. In contrast, GIS buffer measures explain approximately 90% of the variation. Combining a 1-km circle with a road-network buffer provides the closest approximation of actual residential density. Conclusion Residential density based on census units can mask clusters of development in rural areas and distort associations between residential density and health-related behaviors and outcomes. GIS-defined buffers, including a 1-km circle and a road-network buffer, can be used in conjunction with census data to obtain a more accurate measure of residential density.

  17. Accurate three-dimensional shape and deformation measurement at microscale using digital image correlation

    Science.gov (United States)

    Ren, Maodong; Liang, Jin; Li, Leigang; Wei, Bin; Wang, Lizhong; Tang, Zhengzong

    2015-07-01

    Based on stereomicroscope and three-dimensional (3D) digital image correlation (DIC) method, a non-contact measurement technique is presented to measure the 3D shape and deformation data on miniature specimens and the corresponding microscopic measurement system is developed. A pair of cameras is mounted on a binocular stereo light microscope to acquire pairing micrographs from two different optical paths of a specimen surface spraying with speckle pattern. Considering complex optical paths and high magnification, an accurate equivalent relative calibration method, combining a priori warping functions, is proposed to correct image distortions and optimize the intrinsic and extrinsic parameters of stereomicroscope. Then, a fast one-dimensional synchronous stereo matching method, based on the DIC method and image rectification technique, is proposed to search for discontinuous corresponding points in the pairing micrographs. Finally, the 3D shape is reconstructed from the corresponding points, while the temporal micrographs acquired before and after deformation are employed to determine the full-field deformation. The effectiveness and accuracy of the presented microscale measurement technique are verified by a series of experiments.

  18. Validation study of a fast, accurate, and precise brain tumor volume measurement.

    Science.gov (United States)

    Dang, Mong; Modi, Jayesh; Roberts, Mike; Chan, Christopher; Mitchell, J Ross

    2013-08-01

    Precision and accuracy are sometimes sacrificed to ensure that medical image processing is rapid. To address this, our lab had developed a novel level set segmentation algorithm that is 16× faster and >96% accurate on realistic brain phantoms. This study reports speed, precision and estimated accuracy of our algorithm when measuring MRIs of meningioma brain tumors and compares it to manual tracing and modified MacDonald (MM) ellipsoid criteria. A repeated-measures study allowed us to determine measurement precisions (MPs) - clinically relevant thresholds for statistically significant change. Speed: the level set, MM, and trace methods required 1:20, 1:35, and 9:35 (mm:ss) respectively on average to complete a volume measurement (plesion volumes (p>0.05). Precision: the MM's within-operator and between-operator MPs were significantly higher (worse) than the other methods (p0.05). Our level set is faster on average than MM, yet has accuracy and precision comparable to manual tracing. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  19. Measurement of shot noise in magnetic tunnel junction and its utilization for accurate system calibration

    Science.gov (United States)

    Tamaru, S.; Kubota, H.; Yakushiji, K.; Fukushima, A.; Yuasa, S.

    2017-11-01

    This work presents a technique to calibrate the spin torque oscillator (STO) measurement system by utilizing the whiteness of shot noise. The raw shot noise spectrum in a magnetic tunnel junction based STO in the microwave frequency range is obtained by first subtracting the baseline noise, and then excluding the field dependent mag-noise components reflecting the thermally excited spin wave resonances. As the shot noise is guaranteed to be completely white, the total gain of the signal path should be proportional to the shot noise spectrum obtained by the above procedure, which allows for an accurate gain calibration of the system and a quantitative determination of each noise power. The power spectral density of the shot noise as a function of bias voltage obtained by this technique was compared with a theoretical calculation, which showed excellent agreement when the Fano factor was assumed to be 0.99.

  20. A simple and accurate onset detection method for a measured bell-shaped speed profile

    Directory of Open Access Journals (Sweden)

    Lior Botzer

    2009-06-01

    Full Text Available Motor control neuroscientists measure limb trajectories and extract the onset of the movement for a variety of purposes. Such trajectories are often aligned relative to the onset of individual movement before the features of that movement are extracted and their properties are inspected. Onset detection is performed either manually or automatically, typically by selecting a velocity threshold. Here, we present a simple onset detection algorithm that is more accurate than the conventional velocity threshold technique. The proposed method is based on a simple regression and follows the minimum acceleration with constraints model, in which the initial phase of the bell-shaped movement is modeled by a cubic power of the time. We demonstrate the performance of the suggested method and compare it to the velocity threshold technique and to manual onset detection by a group of motor control experts. The database for this comparison consists of simulated minimum jerk trajectories and recorded reaching movements.

  1. Measuring solar reflectance Part I: Defining a metric that accurately predicts solar heat gain

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, Ronnen; Akbari, Hashem; Berdahl, Paul

    2010-05-14

    Solar reflectance can vary with the spectral and angular distributions of incident sunlight, which in turn depend on surface orientation, solar position and atmospheric conditions. A widely used solar reflectance metric based on the ASTM Standard E891 beam-normal solar spectral irradiance underestimates the solar heat gain of a spectrally selective 'cool colored' surface because this irradiance contains a greater fraction of near-infrared light than typically found in ordinary (unconcentrated) global sunlight. At mainland U.S. latitudes, this metric RE891BN can underestimate the annual peak solar heat gain of a typical roof or pavement (slope {le} 5:12 [23{sup o}]) by as much as 89 W m{sup -2}, and underestimate its peak surface temperature by up to 5 K. Using R{sub E891BN} to characterize roofs in a building energy simulation can exaggerate the economic value N of annual cool-roof net energy savings by as much as 23%. We define clear-sky air mass one global horizontal ('AM1GH') solar reflectance R{sub g,0}, a simple and easily measured property that more accurately predicts solar heat gain. R{sub g,0} predicts the annual peak solar heat gain of a roof or pavement to within 2 W m{sup -2}, and overestimates N by no more than 3%. R{sub g,0} is well suited to rating the solar reflectances of roofs, pavements and walls. We show in Part II that R{sub g,0} can be easily and accurately measured with a pyranometer, a solar spectrophotometer or version 6 of the Solar Spectrum Reflectometer.

  2. Accurate measurements of frontal analysis for the determination of adsorption isotherms in supercritical fluid chromatography.

    Science.gov (United States)

    Kamarei, Fahimeh; Gritti, Fabrice; Guiochon, Georges; Burchell, John

    2014-02-14

    The implementation of the traditional FA method is difficult with classical supercritical fluid chromatography (SFC) instruments. The instrument mixer and other sources of extra-column volumes are large and significantly broaden the fronts of injected plugs, which diminishes the precision and accuracy of the FA method. An SFC instrument was modified to permit more accurate determinations of adsorption isotherm data. The sample, the modifier, and CO2 are separately pumped via small volume connection tubes into a small volume mixer (250μL), where they are mixed into a homogeneous fluid fed to the column. The extra-column volumes and the column hold-up volume were accurately measured at each back pressure from the retention times of tracers. This modified instrument was used to measure the adsorption isotherm of S-naproxen by frontal analysis (FA) on a (R, R)-Whelk-O1 column, using a mixture of methanol (20%, v/v) and CO2 as the mobile phase. Its performance is studied at several different back pressures from 100 to 210bar. In all the experiments, the total flow rate was kept to a low value (1mL/min) in order to minimize the variation of the equilibrium constant along the column. Although a suitable breakthrough curve could not be obtained at low back pressures (150bar), conditions remote from the critical point and breakthrough curves with very sharp front shocks are obtained. The RSDs of the profiles recorded at each back pressures are excellent, better than 1%. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Skinfold anthropometry--the accurate method for fat free mass measurement in COPD.

    Science.gov (United States)

    Hronek, Miloslav; Kovarik, Miroslav; Aimova, Petra; Koblizek, Vladimir; Pavlikova, Ladislava; Salajka, Frantisek; Zadak, Zdenek

    2013-10-01

    Fat free mass index (FFMI) is an independent predictor of metabolic and functional consequences in COPD. For its measurement dual energy X-ray absorptiometry (DEXA), skin-fold anthropometry (SFA), bioelectrical impedance analysis (BIA) and bioimpedance spectroscopy (BIS) are used in clinical practice. The aim of our pilot study was to analyse precisely and critically which method is most accurate and available for common use in clinical practice for measurement of FFM by assessment against relevant DEXA in patients with COPD. This was an observational cross-sectional study of consecutive COPD subjects. FFM by methods of SFA, two versions of BIA, and BIS was compared with that from clinically relevant DEXA in 41 outpatients (mean age 66.5 ± 7.7 yrs) with stable COPD, 34 men and 7 women, with mean BMI 28.2 ± 6.1 kg.m(-2). All methods underestimate FFM in comparison with DEXA. In the general evaluation non-significant differences with the smallest mean bias were demonstrated for SFA (1.2 kg) and BIA (3.8 kg), but there was a difference of more than 9 kg using BIS and BIA COPD methods (p DEXA and SFA was demonstrated via Lin's concordance coefficient and Bland-Altman test. SFA has been demonstrated as an accurate, available and cheap method for determination of FFM and FM with application of the Durnin Womersley equation for body density and with the Siri equation for FM in patients with COPD. SFA can be easily applied in routine clinical practice.

  4. Root resistance to cavitation is accurately measured using a centrifuge technique.

    Science.gov (United States)

    Pratt, R B; MacKinnon, E D; Venturas, M D; Crous, C J; Jacobsen, A L

    2015-02-01

    Plants transport water under negative pressure and this makes their xylem vulnerable to cavitation. Among plant organs, root xylem is often highly vulnerable to cavitation due to water stress. The use of centrifuge methods to study organs, such as roots, that have long vessels are hypothesized to produce erroneous estimates of cavitation resistance due to the presence of open vessels through measured samples. The assumption that roots have long vessels may be premature since data for root vessel length are sparse; moreover, recent studies have not supported the existence of a long-vessel artifact for stems when a standard centrifuge technique was used. We examined resistance to cavitation estimated using a standard centrifuge technique and compared these values with native embolism measurements for roots of seven woody species grown in a common garden. For one species we also measured vulnerability using single-vessel air injection. We found excellent agreement between root native embolism and the levels of embolism measured using a centrifuge technique, and with air-seeding estimates from single-vessel injection. Estimates of cavitation resistance measured from centrifuge curves were biologically meaningful and were correlated with field minimum water potentials, vessel diameter (VD), maximum xylem-specific conductivity (Ksmax) and vessel length. Roots did not have unusually long vessels compared with stems; moreover, root vessel length was not correlated to VD or to the vessel length of stems. These results suggest that root cavitation resistance can be accurately and efficiently measured using a standard centrifuge method and that roots are highly vulnerable to cavitation. The role of root cavitation resistance in determining drought tolerance of woody species deserves further study, particularly in the context of climate change. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Accurate Fluid Level Measurement in Dynamic Environment Using Ultrasonic Sensor and ν-SVM

    Directory of Open Access Journals (Sweden)

    Jenny TERZIC

    2009-10-01

    Full Text Available A fluid level measurement system based on a single Ultrasonic Sensor and Support Vector Machines (SVM based signal processing and classification system has been developed to determine the fluid level in automotive fuel tanks. The novel approach based on the ν-SVM classification method uses the Radial Basis Function (RBF to compensate for the measurement error induced by the sloshing effects in the tank caused by vehicle motion. A broad investigation on selected pre-processing filters, namely, Moving Mean, Moving Median, and Wavelet filter, has also been presented. Field drive trials were performed under normal driving conditions at various fuel volumes ranging from 5 L to 50 L to acquire sample data from the ultrasonic sensor for the training of SVM model. Further drive trials were conducted to obtain data to verify the SVM results. A comparison of the accuracy of the predicted fluid level obtained using SVM and the pre-processing filters is provided. It is demonstrated that the ν-SVM model using the RBF kernel function and the Moving Median filter has produced the most accurate outcome compared with the other signal filtration methods in terms of fluid level measurement.

  6. Accurate measurement of the optical activity of alanine crystals and the determination of their absolute chirality

    Science.gov (United States)

    Ishikawa, Kazuhiko; Terasawa, Yukana; Tanaka, Masahito; Asahi, Toru

    2017-05-01

    Wavelength dependence measurements of the chiroptical properties in alanine crystals have so far been unsuccessful using conventional spectroscopic techniques. We describe our attempts to measure the wavelength dependence of the optical activity in L- and D-alanine crystals along each crystallographic axis, and to determine the absolute chirality of alanine crystals by correlating the absolute structure to the optical activity using an x-ray diffractometer and a generalized high accuracy universal polarimeter. We have succeeded in accurately measuring the optical rotatory dispersion in the direction, which shows that the optical rotation of the D-alanine crystal is dextrorotatory and that of the L-alanine crystal is laevorotatory, thereby determining the absolute chirality. Furthermore, comparison with the optical activity in solution shows that the optical activity in alanine crystals is different not only in value, but also in the sign. These results have led us to conclude that the optical rotatory power in the crystalline state should not be simply the summation of molecular optical rotatory power values. We propose the necessity of a theory, which contains the contribution of molecular interactions within the crystal, in order to calculate the optical rotatory power of the crystalline state.

  7. On the use of a recombination chamber for radiation measurements in CERN-EU high energy reference radiation fields

    CERN Document Server

    Golnik, N; Otto, T

    1999-01-01

    Ambient dose equivalent was determined in high energy reference radiation fields at CERN (CERF facility) using a recombination chamber and recombination methods developed in IAE. The chamber was also used for measuring the low LET background radiation which locally accompanies the fields at CERF. The measurements included determination of the absorbed dose and recombination index of radiation quality at different beam intensities. It was shown that the background might considerably influence the measurements of the absorbed dose, however, its influence on the ambient dose equivalent remains important only at low beam intensities. (16 refs).

  8. Matrix Effects in Proficiency Testing Materials Influence the Accurate Measurement of Gamma-Glutamyltransferase Activity.

    Science.gov (United States)

    Li, Yun; Wang, Jianbing; Huang, Xianzhang; Zeng, Ruili; Zhang, Qiaoxuan; Lin, Haibiao; Han, Liqiao; Ke, Peifeng; Zhuang, Junhua

    2016-10-01

    A consensus on an accurate method to measure γ-glutamyltransferase (GGT) activity for clinical purposes has not been achieved among practicing clinical laboratories. To improve analytical trueness, we evaluated the influences of matrix effects in proficiency testing (PT) materials on the measurement of GGT activity in human serum samples. Five fresh frozen human samples (FFS1-5) and five lyophilized proficiency testing materials (Lyo1-5) were distributed to 23 participating clinical laboratories for the measurement of GGT activity. Target GGT activity values for the samples were obtained by using previously approved reference methods. The results obtained by the Beckman Coulter Unicel DxC 800 Synchron analyzer were compared to the target values assigned by two reference laboratories, and the commutability of the lyophilized materials was evaluated according to Clinical and Laboratory Standards Institute (CLSI) guideline EP14-A2. The relative bias between the results obtained by the Beckman Coulter analyzer and the reference target values ranged from -27.2% to -18.0% for FFS1-5 and from 9.1% to 2.5% for Lyo1-5. Non-commutability of all lyophilized samples falling outside of the 95% prediction interval was observed. The results obtained for the lyophilized PT materials were deemed acceptable within the total allowable errors, suggesting that matrix effects may impart a false sense of confidence that clinical analytical systems are performing very well. A primary reference measurement procedure on fresh frozen serum provides a valuable method for evaluating the trueness of results measured by PT.

  9. A fast method based on NESTA to accurately reconstruct CT image from highly undersampled projection measurements.

    Science.gov (United States)

    He, Zhijie; Qiao, Quanbang; Li, Jun; Huang, Meiping; Zhu, Shouping; Huang, Liyu

    2016-11-22

    The CT image reconstruction algorithm based compressed sensing (CS) can be formulated as an optimization problem that minimizes the total-variation (TV) term constrained by the data fidelity and image nonnegativity. There are a lot of solutions to this problem, but the computational efficiency and reconstructed image quality of these methods still need to be improved. To investigate a faster and more accurate mathematical algorithm to settle TV term minimization problem of CT image reconstruction. A Nesterov's algorithm (NESTA) is a fast and accurate algorithm for solving TV minimization problem, which can be ascribed to the use of most notably Nesterov's smoothing technique and a subtle averaging of sequences of iterates, which has been shown to improve the convergence properties of standard gradient-descent algorithms. In order to demonstrate the superior performance of NESTA on computational efficiency and image quality, a comparison with Simultaneous Algebraic Reconstruction Technique-TV (SART-TV) and Split-Bregman (SpBr) algorithm is made using a digital phantom study and two physical phantom studies from highly undersampled projection measurements. With only 25% of conventional full-scan dose and, NESTA method reduces the average CT number error from 51.76HU to 9.98HU on Shepp-Logan phantom and reduces the average CT number error from 50.13HU to 0.32HU on Catphan 600 phantom. On an anthropomorphic head phantom, the average CT number error is reduced from 84.21HU to 1.01HU in the central uniform area. To the best of our knowledge this is the first work that apply the NESTA method into CT reconstruction based CS. Research shows that this method is of great potential, further studies and optimization are necessary.

  10. Galinstan thermometer is more accurate than digital for the measurement of body temperature in children.

    Science.gov (United States)

    Schreiber, Silvana; Minute, Marta; Tornese, Gianluca; Giorgi, Rita; Duranti, Marina; Ronfani, Luca; Barbi, Egidio

    2013-02-01

    The mercury thermometer (MT) was considered the reference standard for the evaluation of body temperature; however, since April 2009, it has no longer been available in Italy. This study aimed to evaluate the accuracy of digital thermometer (DT) and galinstan thermometer (GT) in comparison with the MT. We prospectively recruited 284 children (age, 1 month to 17 years; mean, 8.5 years) seen in the emergency department of a tertiary pediatric hospital between November and December 2010. For each patient, body temperature was measured sequentially in the right axilla in a randomized fashion using DT, GT, and MT. Fever was defined as an axillary temperature of 37.5°C or greater. The temperature readings with DT and GT were compared statistically with those of MT (reference standard). No statistically significant difference in mean temperature was found between MT and GT in pairwise comparison (P = 0.06), whereas significant differences were found between MT and DT (P temperature of 39°C or higher, the false-negative rate was 65.4% with DT and 30.8% with GT. Although both DT and GT had good specificity and positive predictive value compared with MT, GT had higher sensitivity and a lower rate of false-negative rates. Galinstan thermometer is more accurate in the measurement of body temperature compared with DT or MT.

  11. An Accurate Non-Cooperative Method for Measuring Textureless Spherical Target Based on Calibrated Lasers

    Directory of Open Access Journals (Sweden)

    Fei Wang

    2016-12-01

    Full Text Available Strong demands for accurate non-cooperative target measurement have been arising recently for the tasks of assembling and capturing. Spherical objects are one of the most common targets in these applications. However, the performance of the traditional vision-based reconstruction method was limited for practical use when handling poorly-textured targets. In this paper, we propose a novel multi-sensor fusion system for measuring and reconstructing textureless non-cooperative spherical targets. Our system consists of four simple lasers and a visual camera. This paper presents a complete framework of estimating the geometric parameters of textureless spherical targets: (1 an approach to calibrate the extrinsic parameters between a camera and simple lasers; and (2 a method to reconstruct the 3D position of the laser spots on the target surface and achieve the refined results via an optimized scheme. The experiment results show that our proposed calibration method can obtain a fine calibration result, which is comparable to the state-of-the-art LRF-based methods, and our calibrated system can estimate the geometric parameters with high accuracy in real time.

  12. Schiotz tonometry accurately measures intraocular pressure in Boston type 1 keratoprosthesis eyes.

    Science.gov (United States)

    Estrovich, Igor E; Shen, Chris; Chu, Yvonne; Downs, J Crawford; Gardiner, Stuart; Straiko, Michael; Mansberger, Steven L

    2015-06-01

    To evaluate the location of the eye and tonometry device that provides the most accurate intraocular pressure (IOP) measurements in eyes with Boston type 1 keratoprosthesis. A single surgeon sutured a Boston keratoprosthesis into the central cornea in the usual manner in 5 eyes of deceased donors. Another investigator used a 27-gauge needle, digital manometry, and gravity infusion to set the IOP at levels of 10, 20, 30, and 40 mm Hg in random order. A second investigator masked to the level of IOP used a Schiotz tonometer (Sklar) with a 7.5-g plunger load and a Tono-pen XL tonometer (Medtronic) to determine IOP at the temporal corneoscleral limbus and temporal sclera (3 mm temporal to the corneoscleral limbus). We used generalized estimation equation models to determine an average absolute difference between the tonometer measurements compared with the "gold standard" digital manometric IOP. The Schiotz tonometer had a lower median absolute error compared with the Tono-pen at both temporal sclera (5.4 mm Hg vs. 39.0 mm Hg, P keratoprosthesis.

  13. An easy way to measure accurately the direct magnetoelectric voltage coefficient of thin film devices

    Energy Technology Data Exchange (ETDEWEB)

    Poullain, Gilles, E-mail: gilles.poullain@ensicaen.fr; More-Chevalier, Joris; Cibert, Christophe; Bouregba, Rachid

    2017-01-15

    Tb{sub x}Dy{sub 1−x}Fe{sub 2}/Pt/Pb(Zr{sub x}, Ti{sub 1−x})O{sub 3} thin films were grown on Pt/TiO{sub 2}/SiO{sub 2}/Si substrate by multi-target sputtering. The magnetoelectric voltage coefficient α{sup Η}{sub ΜΕ} was determined at room temperature using a lock-in amplifier. By adding, in series in the circuit, a capacitor of the same value as that of the device under test, we were able to demonstrate that the magnetoelectric device behaves as a voltage source. Furthermore, a simple way to subtract the stray voltage arising from the flow of eddy currents in the measurement set-up, is proposed. This allows the easy and accurate determination of the true magnetoelectric voltage coefficient. A large α{sup Η}{sub ΜΕ} of 8.3 V/cm. Oe was thus obtained for a Terfenol-D/Pt/PZT thin film device, without DC magnetic field nor mechanical resonance. - Highlights: • Magnetoelectric device behaves as a voltage source. • A simple way to subtract eddy currents during the measurement, is proposed.

  14. 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.

  15. Accurate quantification of glass-forming ability by measuring effective volume relaxation of supercooled melt

    Science.gov (United States)

    Ryu, C. W.; Kang, D. H.; Jeon, S.; Lee, G. W.; Park, E. S.

    2017-10-01

    Herein, we elucidate how to accurately quantify glass-forming ability (GFA) by measuring effective volume relaxation of supercooled melt. We propose a new parameter, denoted as κ, for representing the relaxation, which is calculated by combining temperature-dependent changes of normalized specific volume reflecting relative volume relaxation with the normalized temperature range reflecting the relative position of the C curve in a Time-Temperature-Transformation (TTT) diagram. The interrelationship between the κ parameter and critical cooling rate is elaborated by measuring V-T diagrams and TTT diagrams of Zr55Co26Al19 and Zr46Cu30.14Al8Ag8.36Be7.5 glass-forming alloys and discussed in comparison with representative GFA parameters reported up to date. These results would give us a guideline on how to precisely evaluate GFA by linking volumetric aspect to thermodynamic and kinetic aspects for glass formation and help develop customized glass-forming alloys as well as a highly precise control of glass formation process.

  16. A Novel IgM-capture enzyme-linked immunosorbent assay using recombinant Vag8 fusion protein for the accurate and early diagnosis of Bordetella pertussis infection.

    Science.gov (United States)

    Otsuka, Nao; Gotoh, Kensei; Nishimura, Naoko; Ozaki, Takao; Nakamura, Yukitsugu; Haga, Kiyohito; Yamazaki, Makoto; Gondaira, Fumio; Okada, Kenji; Miyaji, Yusuke; Toyoizumi-Ajisaka, Hiromi; Shibayama, Keigo; Arakawa, Yoshichika; Kamachi, Kazunari

    2016-05-01

    An ELISA that measures anti-PT IgG antibody has been used widely for the serodiagnosis of pertussis; however, the IgG-based ELISA is inadequate for patients during the acute phase of the disease because of the slow response of anti-PT IgG antibodies. To solve this problem, we developed a novel IgM-capture ELISA that measures serum anti-Bordetella pertussis Vag8 IgM levels for the accurate and early diagnosis of pertussis. First, we confirmed that Vag8 was highly expressed in all B. pertussis isolates tested (n = 30), but little or none in other Bordetella species, and that DTaP vaccines did not induce anti-Vag8 IgG antibodies in mice (i.e. the antibody level could be unaffected by the vaccination). To determine the immune response to Vag8 in B. pertussis infection, anti-Vag8 IgM levels were compared between 38 patients (acute phase of pertussis) and 29 healthy individuals using the anti-Vag8 IgM-capture ELISA. The results revealed that the anti-Vag8 IgM levels were significantly higher in the patients compared with the healthy individuals (P pertussis infection. © 2016 The Societies and John Wiley & Sons Australia, Ltd.

  17. Accurate measurement of absolute experimental inelastic mean free paths and EELS differential cross-sections

    Energy Technology Data Exchange (ETDEWEB)

    Craven, Alan J.; Bobynko, Joanna; Sala, Bianca; MacLaren, Ian, E-mail: ian.maclaren@glasgow.ac.uk

    2016-11-15

    Methods are described for measuring accurate absolute experimental inelastic mean free paths and differential cross-sections using DualEELS. The methods remove the effects of surface layers and give the results for the bulk materials. The materials used are VC{sub 0.83}, TiC{sub 0.98}, VN{sub 0.97} and TiN{sub 0.88} but the method should be applicable to a wide range of materials. The data was taken at 200 keV using a probe half angle of 29 mrad and a collection angle of 36 mrad. The background can be subtracted from under the ionisation edges, which can then be separated from each other. This is achieved by scaling Hartree-Slater calculated cross-sections to the edges in the atomic regions well above the threshold. The average scaling factors required are 1.00 for the non-metal K-edges and 1.01 for the metal L-edges (with uncertainties of a few percent). If preliminary measurements of the chromatic effects in the post-specimen lenses are correct, both drop to 0.99. The inelastic mean free path for TiC{sub 0.98} was measured as 103.6±0.5 nm compared to the prediction of 126.9 nm based on the widely used Iakoubovskii parameterisation. - Highlights: • We show how to extract absolute cross sections for EELS edges using DualEELS. • The method removes the effects of any surface layers on standards. • We use a needle specimen to determining the mean free path for inelastic scattering. • Constrained background fitting is essential to correct background subtraction. • Absolute cross sections are determined for TiC, TiN, VC and VN.

  18. Sitting and standing blood pressure measurements are not accurate for the diagnosis of orthostatic hypotension.

    LENUS (Irish Health Repository)

    Cooke, J

    2012-01-31

    INTRODUCTION: Orthostatic hypotension (OH) is associated with troublesome symptoms and increased mortality. It is treatable and deserving of accurate diagnosis. This can be time consuming. The current reference standard for its diagnosis is head-up tilt (HUT) testing with continuous beat-to-beat plethysmography. Our objective was to assess the accuracy of sit-stand testing with semi-automatic sphygmomanometry for the diagnosis of OH. DESIGN: Retrospective test of diagnostic accuracy. METHODS: This was a retrospective study performed using a database maintained by a busy syncope unit. HUT testing was performed using an automated tilt table with Finometer monitoring. A 3 min 70 degrees HUT was performed following 5 min supine. Sitting blood pressure (BP) was measured following 3 min rest. Standing BP was measured within 30 s of assuming the upright posture. The results of sit-stand testing were compared with HUT testing as a reference standard. Both tests happened within 5 min of each other and patients underwent no intervention between tests. RESULTS: From a total of 1452 consecutive HUTs, we identified 730 with pre-test measures of sitting and standing BP. The mean age of this group was 70.57 years (SD = 15.1), 62% were female. The sensitivity of sit-stand testing was calculated as 15.5%, specificity as 89.9%, positive predictive value as 61.7%, negative predictive value as 50.2% and the likelihood ratio as 1.6. The area under the Receiver Operator Curve was 0.564. CONCLUSION: We have demonstrated that sit-stand testing for OH has very low diagnostic accuracy. We recommend that the more time-consuming reference standard method of diagnosis be used if the condition is suspected.

  19. Accurate 3D kinematic measurement of temporomandibular joint using X-ray fluoroscopic images

    Science.gov (United States)

    Yamazaki, Takaharu; Matsumoto, Akiko; Sugamoto, Kazuomi; Matsumoto, Ken; Kakimoto, Naoya; Yura, Yoshiaki

    2014-04-01

    Accurate measurement and analysis of 3D kinematics of temporomandibular joint (TMJ) is very important for assisting clinical diagnosis and treatment of prosthodontics and orthodontics, and oral surgery. This study presents a new 3D kinematic measurement technique of the TMJ using X-ray fluoroscopic images, which can easily obtain the TMJ kinematic data in natural motion. In vivo kinematics of the TMJ (maxilla and mandibular bone) is determined using a feature-based 2D/3D registration, which uses beads silhouette on fluoroscopic images and 3D surface bone models with beads. The 3D surface models of maxilla and mandibular bone with beads were created from CT scans data of the subject using the mouthpiece with the seven strategically placed beads. In order to validate the accuracy of pose estimation for the maxilla and mandibular bone, computer simulation test was performed using five patterns of synthetic tantalum beads silhouette images. In the clinical applications, dynamic movement during jaw opening and closing was conducted, and the relative pose of the mandibular bone with respect to the maxilla bone was determined. The results of computer simulation test showed that the root mean square errors were sufficiently smaller than 1.0 mm and 1.0 degree. In the results of clinical application, during jaw opening from 0.0 to 36.8 degree of rotation, mandibular condyle exhibited 19.8 mm of anterior sliding relative to maxillary articular fossa, and these measurement values were clinically similar to the previous reports. Consequently, present technique was thought to be suitable for the 3D TMJ kinematic analysis.

  20. Measuring sparse temporal-variation for accurate registration of dynamic contrast-enhanced breast MR images.

    Science.gov (United States)

    Zheng, Yuanjie; Wei, Benzheng; Liu, Hui; Xiao, Rui; Gee, James C

    2015-12-01

    Accurate registration of dynamic contrast-enhanced (DCE) MR breast images is challenging due to the temporal variations of image intensity and the non-rigidity of breast motion. The former can cause the well-known tumor shrinking/expanding problem in registration process while the latter complicates the task by requiring an estimation of non-rigid deformation. In this paper, we treat the intensity's temporal variations as "corruptions" which spatially distribute in a sparse pattern and model them with a L1 norm and a Lorentzian norm. We show that these new image similarity measurements can characterize the non-Gaussian property of the difference between the pre-contrast and post-contrast images and help to resolve the shrinking/expanding problem by forgiving significant image variations. Furthermore, we propose an iteratively re-weighted least squares based method and a linear programming based technique for optimizing the objective functions obtained using these two novel norms. We show that these optimization techniques outperform the traditional gradient-descent approach. Experimental results with sequential DCE-MR images from 28 patients show the superior performances of our algorithms. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Accurate measurement of the localization properties of electric transmission lines using the overlap amplitude

    Science.gov (United States)

    Lazo, Edmundo

    2017-06-01

    We determine the localization properties of classic direct electric transmission lines by means of the overlap amplitude. The amplitude is defined as C i,j ω = 2| I i ω I j ω |, where I i ω is the electric current in the ith cell of the transmission line for the state with frequency ω. This definition is motivated by the concurrence C i,j α = 2| φ i α φ j α |, which is a quantum correlation measure (pairwise entanglement). We distribute the inductances L j according to three non-linear models: (a) the slowly varying potential model; (b) the Aubry-André model and (c) the Soukoulis-Economou model. The results show that the average of the powers of the overlap amplitude ⟨( C i,j ω )2 q ⟩ and its scaling properties may accurately characterize the localization behavior of these non-linear models. Moreover, the overlap amplitude can be used to determine the mobility edge of some non-periodic models.

  2. ESR isochron exercises: how accurately do modern dose rate measurements reflect paleodose rates?

    Science.gov (United States)

    Blackwell, B. A. B.; Skinner, A. R.; Blickstein, J. I. B.

    2001-12-01

    In electron spin resonance (ESR) dating tooth enamel, after selecting the appropriate U uptake model, the most significant uncertainty lies in the external dose rate, Dext( t), which can vary with time. Unlike standard ESR which measures the external dose rate in the modern context, Dext( t0), assuming that it reflects the actual external dose rate over the millennia, the isochron method calculates the time-averaged dose rate, D¯ext(t) , experienced by the tooth without such assumptions. In 45 teeth ranging from 30 ka to 4.5 Ma from 17 sites, D¯ext(t) determined by EU or LU isochrons only equalled Dext( t0) about 50% of the time. In several sites, geologic evidence indicates that secondary sedimentary processes have significantly altered sedimentary compositions and/or water concentrations, and hence, Dext( t), over time, accounting for 60-80% of D¯ext(t)-D ext(t 0) disagreements. Simulated isochrons suggest that at least seven teeth, whose isochrons had negative ages or D¯ext(t) , probably had lost U, while five, with accurate ages but very large D¯ext(t) , have likely experienced a second U uptake event.

  3. Accurate measurement of transgene copy number in crop plants using droplet digital PCR.

    Science.gov (United States)

    Collier, Ray; Dasgupta, Kasturi; Xing, Yan-Ping; Hernandez, Bryan Tarape; Shao, Min; Rohozinski, Dominica; Kovak, Emma; Lin, Jeanie; de Oliveira, Maria Luiza P; Stover, Ed; McCue, Kent F; Harmon, Frank G; Blechl, Ann; Thomson, James G; Thilmony, Roger

    2017-06-01

    Genetic transformation is a powerful means for the improvement of crop plants, but requires labor- and resource-intensive methods. An efficient method for identifying single-copy transgene insertion events from a population of independent transgenic lines is desirable. Currently, transgene copy number is estimated by either Southern blot hybridization analyses or quantitative polymerase chain reaction (qPCR) experiments. Southern hybridization is a convincing and reliable method, but it also is expensive, time-consuming and often requires a large amount of genomic DNA and radioactively labeled probes. Alternatively, qPCR requires less DNA and is potentially simpler to perform, but its results can lack the accuracy and precision needed to confidently distinguish between one- and two-copy events in transgenic plants with large genomes. To address this need, we developed a droplet digital PCR-based method for transgene copy number measurement in an array of crops: rice, citrus, potato, maize, tomato and wheat. The method utilizes specific primers to amplify target transgenes, and endogenous reference genes in a single duplexed reaction containing thousands of droplets. Endpoint amplicon production in the droplets is detected and quantified using sequence-specific fluorescently labeled probes. The results demonstrate that this approach can generate confident copy number measurements in independent transgenic lines in these crop species. This method and the compendium of probes and primers will be a useful resource for the plant research community, enabling the simple and accurate determination of transgene copy number in these six important crop species. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  4. Accurate concentration measurements using surface-enhanced Raman and deuterium exchanged dye pairs.

    Science.gov (United States)

    Deb, Shirshendu K; Davis, Brandon; Ben-Amotz, Dor; Davisson, V Jo

    2008-09-01

    Quantitative applications of surface-enhanced resonance Raman scattering (SERRS) are often limited by the reproducibility of SERRS intensities, given the difficulty of controlling analyte-substrate interactions and the associated local field enhancement. As demonstrated here, SERRS from dye molecules even within the same structural class that compete with similar substrates display distinct spectral intensities that are not proportional to analyte concentrations, which limits their use as internal standardization probes and/or for multiplex analysis. Recently, we demonstrated that isotopic variants of rhodamine 6G (R6G), namely R6G-d0 and R6G-d4, can be used for internal standards in SERRS experiments with a linear optical response from picomolar to micromolar concentrations (of total analytes). Here we extend these results by describing a straightforward method for obtaining isotopomeric pairs of other Raman active dyes by hydrogen-deuterium exchange conditions for substitution at electron rich aromatic heterocycles. Most of the known SERRS active probes can be converted into the corresponding isotopomeric molecule by this exchange method, which significantly expands the scope of the isotopic edited internal standard (IEIS) approach. The relative quantification using IEIS enables accurate, reproducible (residual standard deviation+/-2.2%) concentration measurements over a range of 200 pM to 2 microM. These studies enable easy access to a variety of isotopically substituted Raman active dyes and establish the generality of the methodology for quantitative SERRS measurements. For the first time, three rhodamine 6G isotopomers have been created and show distinct Raman spectra, demonstrating the principle of the approach for application as a multiplex technique in biomolecular detection/quantification.

  5. Accurate measurements of {sup 210}Pb in industrial wastes for environmental radiation risk assessment purpose

    Energy Technology Data Exchange (ETDEWEB)

    Bonczyk, Michal; Michalik, Boguslaw [Central Mining Institute, Silesian Centre for Environmental Radioactivity, Plac Gwarkow 1, 40-166 Katowice (Poland)

    2014-07-01

    Lead {sup 210}Pb is a naturally occurring radioactive nuclide element of the uranium ({sup 238}U) radioactive series. It is produced as a result of the decay of so-called short-lived progenies of {sup 222}Rn, i.e. {sup 214}Po (99.98%) and {sup 214}Bi by {sup 219}Tl (0.02%). Activity concentration of lead {sup 210}Pb could vary independently from parent radionuclides due to its physical and chemical properties, especially, due to its half-life (T{sub 1/2} = 22,3 years). Hence, its behaviour in natural environment is very complex and difficult in forecasting. Lead {sup 210}Pb in substantial amount occurs in mining, gas and oil extraction industry wastes, which are deposited in natural environment very often. Due to lack of secular equilibrium proper radiation risk assessment requires accurate concentration of {sup 210}Pb in such materials. The laboratory measurements seem to be the only reliable method in environmental radioactivity monitoring. One of the methods is gamma-ray spectrometry, which is very fast and cost-effective method to determine {sup 210}Pb concentration. On the other hand, the self-attenuation of gamma ray from {sup 210}Pb (46,5 keV) is significant and not depends only on sample density as well the chemical composition (sample matrix) is crucial. Current work describes how the self-attenuation correction factors in the case of {sup 210}Pb concentration analysis in mining wastes are important when environmental radiation risk assessment is carried out. The measurements were done for such industrial wastes as mine sediments which contain significant amount of elements with high Z-number (Barium, Lead, etc.) Experimentally obtained correction factors range between 0.51-6.96 cm{sup 2}/g. Neglecting this factor can cause a significant error or underestimations in radiological risk assessment. (authors)

  6. Progress Report on Accurate Measurement of Dynamic Topography in the Oceanic and Continental Realms

    Science.gov (United States)

    White, N. J.

    2012-12-01

    Convective circulation of the Earth's mantle maintains plate motion but we know little about the spatial and temporal details of this circulation. Accurate maps of the spatial and temporal pattern of dynamic topography should profoundly affect our understanding the the relationship between surface geology and deep Earth processes. The major difficulty is the `tyranny of isostasy'. In other words, dynamic topography is difficult to measure because crustal and lithospheric thickness and density changes are the dominant control of surface elevation. Some progress can be made along continental margins by measuring residual depth anomalies of the oldest oceanic floor on newly available seismic reflection and wide-angle profiles. These estimates of dynamic topography have amplitudes of ± 1 km and wavelengths of 102--104 km. They mostly, but not always, correlate with long wavelength free-air gravity anomalies, although correlation with seismic tomographic images is poorer. The distribution of dynamic topography throughout the rest of the oceanic realm can be supplemented by using ship-track data in regions with sparse sedimentary cover and by exploiting the mid-oceanic ridge system. On the continents, it is more difficult to measure dynamic topography with the same accuracy since the density structure of continental lithosphere is so variable but progress can be made on three fronts. First, long-wavelength gravity anomalies which straddle continental margins are an obvious and important guide. Secondly, stratal geometries across continental shelves contain information about positive and negative surface elevation changes, provided sea-level variation is known. In several cases, well-calibrated seismic surveys can be used to constrain spatial and temporal patterns of dynamic topography. Our results suggest that dynamic topography can rapidly change on short wavelengths. Finally, drainage networks appear to contain information about the spatial and temporal patterns of

  7. Is oral temperature an accurate measurement of deep body temperature? A systematic review.

    Science.gov (United States)

    Mazerolle, Stephanie M; Ganio, Matthew S; Casa, Douglas J; Vingren, Jakob; Klau, Jennifer

    2011-01-01

    Oral temperature might not be a valid method to assess core body temperature. However, many clinicians, including athletic trainers, use it rather than criterion standard methods, such as rectal thermometry. To critically evaluate original research addressing the validity of using oral temperature as a measurement of core body temperature during periods of rest and changing core temperature. In July 2010, we searched the electronic databases PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), SPORTDiscus, Academic Search Premier, and the Cochrane Library for the following concepts: core body temperature, oral, and thermometers. Controlled vocabulary was used, when available, as well as key words and variations of those key words. The search was limited to articles focusing on temperature readings and studies involving human participants. Original research was reviewed using the Physiotherapy Evidence Database (PEDro). Sixteen studies met the inclusion criteria and subsequently were evaluated by 2 independent reviewers. All 16 were included in the review because they met the minimal PEDro score of 4 points (of 10 possible points), with all but 2 scoring 5 points. A critical review of these studies indicated a disparity between oral and criterion standard temperature methods (eg, rectal and esophageal) specifically as the temperature increased. The difference was -0.50°C ± 0.31°C at rest and -0.58°C ± 0.75°C during a nonsteady state. Evidence suggests that, regardless of whether the assessment is recorded at rest or during periods of changing core temperature, oral temperature is an unsuitable diagnostic tool for determining body temperature because many measures demonstrated differences greater than the predetermined validity threshold of 0.27°C (0.5°F). In addition, the differences were greatest at the highest rectal temperatures. Oral temperature cannot accurately reflect core body temperature, probably because it is

  8. Infrared Thermometer: an accurate tool for temperature measurement during renal surgery

    Directory of Open Access Journals (Sweden)

    Giovanni Scala Marchini

    2013-07-01

    Full Text Available Purpose To evaluate infrared thermometer (IRT accuracy compared to standard digital thermometer in measuring kidney temperature during arterial clamping with and without renal cooling. Materials and Methods 20 pigs weighting 20Kg underwent selective right renal arterial clamping, 10 with (Group 1 - Cold Ischemia with ice slush and 10 without renal cooling (Group 2 - Warm Ischemia. Arterial clamping was performed without venous clamping. Renal temperature was serially measured following clamping of the main renal artery with the IRT and a digital contact thermometer (DT: immediate after clamping (T0, after 2 (T2, 5 (T5 and 10 minutes (T10. Temperature values were expressed in mean, standard deviation and range for each thermometer. We used the T student test to compare means and considered p < 0.05 to be statistically significant. Results In Group 1, mean DT surface temperature decrease was 12.6 ± 4.1°C (5-19°C while deep DT temperature decrease was 15.8 ± 1.5°C (15-18°C. For the IRT, mean temperature decrease was 9.1 ± 3.8°C (3-14°C. There was no statistically significant difference between thermometers. In Group 2, surface temperature decrease for DT was 2.7 ± 1.8°C (0-4°C and mean deep temperature decrease was 0.5 ± 1.0°C (0-3°C. For IRT, mean temperature decrease was 3.1 ± 1.9°C (0-6°C. No statistically significant difference between thermometers was found at any time point. conclusions IRT proved to be an accurate non-invasive precise device for renal temperature monitoring during kidney surgery. External ice slush cooling confirmed to be fast and effective at cooling the pig model. IRT = Infrared thermometer DT = Digital contact thermometer D:S = Distance-to-spot ratio

  9. In-situ measurements of material thermal parameters for accurate LED lamp thermal modelling

    NARCIS (Netherlands)

    Vellvehi, M.; Perpina, X.; Jorda, X.; Werkhoven, R.J.; Kunen, J.M.G.; Jakovenko, J.; Bancken, P.; Bolt, P.J.

    2013-01-01

    This work deals with the extraction of key thermal parameters for accurate thermal modelling of LED lamps: air exchange coefficient around the lamp, emissivity and thermal conductivity of all lamp parts. As a case study, an 8W retrofit lamp is presented. To assess simulation results, temperature is

  10. Accurate wavelength prediction of photonic crystal resonant reflection and applications in refractive index measurement

    DEFF Research Database (Denmark)

    Hermannsson, Pétur Gordon; Vannahme, Christoph; Smith, Cameron L. C.

    2014-01-01

    In the past decade, photonic crystal resonant reflectors have been increasingly used as the basis for label-free biochemical assays in lab-on-a-chip applications. In both designing and interpreting experimental results, an accurate model describing the optical behavior of such structures is essen...

  11. Accurate particle speed prediction by improved particle speed measurement and 3-dimensional particle size and shape characterization technique

    DEFF Research Database (Denmark)

    Cernuschi, Federico; Rothleitner, Christian; Clausen, Sønnik

    2017-01-01

    methods, e.g. laser light scattering, and velocity by the double disk (DD) method. In this article we present two novel techniques, which allow a more accurate measurement of mass, velocity and shape, and we later compare the experimentally obtained flow velocities of particles with a simulation that also...... includes the particle's shape parameter, known as sphericity. Mass and sphericity are obtained from 3-dimensional data with an industrial X-ray computed tomography (CT) scanner. CT data can be used to accurately determine the volume-basis median of the particles (using the volume-equivalent particle......Accurate particle mass and velocity measurement is needed for interpreting test results in erosion tests of materials and coatings. The impact and damage of a surface is influenced by the kinetic energy of a particle, i.e. particle mass and velocity. Particle mass is usually determined with optical...

  12. EVALUATION OF OPPORTUNITIES OF SOLAR ENERGETICS ON THE BASIS OF ACCURATE GROUND-BASED MEASUREMENTS OF SOLAR RADIATION

    Directory of Open Access Journals (Sweden)

    Aculinin A.

    2008-04-01

    Full Text Available Expected quantity of a solar energy received by solar panel is estimated on the basis of accurate measurements of solar radiation in Kishinev. Optimal orientation of solar panels and apparent volume of the electric power generated by solar panels are determined.

  13. EVALUATION OF OPPORTUNITIES OF SOLAR ENERGETICS ON THE BASIS OF ACCURATE GROUND-BASED MEASUREMENTS OF SOLAR RADIATION

    OpenAIRE

    Aculinin A.; Smikov V.

    2008-01-01

    Expected quantity of a solar energy received by solar panel is estimated on the basis of accurate measurements of solar radiation in Kishinev. Optimal orientation of solar panels and apparent volume of the electric power generated by solar panels are determined.

  14. Accurate radiocarbon age estimation using "early" measurements: a new approach to reconstructing the Paleolithic absolute chronology

    Science.gov (United States)

    Omori, Takayuki; Sano, Katsuhiro; Yoneda, Minoru

    2014-05-01

    This paper presents new correction approaches for "early" radiocarbon ages to reconstruct the Paleolithic absolute chronology. In order to discuss time-space distribution about the replacement of archaic humans, including Neanderthals in Europe, by the modern humans, a massive data, which covers a wide-area, would be needed. Today, some radiocarbon databases focused on the Paleolithic have been published and used for chronological studies. From a viewpoint of current analytical technology, however, the any database have unreliable results that make interpretation of radiocarbon dates difficult. Most of these unreliable ages had been published in the early days of radiocarbon analysis. In recent years, new analytical methods to determine highly-accurate dates have been developed. Ultrafiltration and ABOx-SC methods, as new sample pretreatments for bone and charcoal respectively, have attracted attention because they could remove imperceptible contaminates and derive reliable accurately ages. In order to evaluate the reliability of "early" data, we investigated the differences and variabilities of radiocarbon ages on different pretreatments, and attempted to develop correction functions for the assessment of the reliability. It can be expected that reliability of the corrected age is increased and the age applied to chronological research together with recent ages. Here, we introduce the methodological frameworks and archaeological applications.

  15. Lightdrum—Portable Light Stage for Accurate BTF Measurement on Site

    Directory of Open Access Journals (Sweden)

    Vlastimil Havran

    2017-02-01

    Full Text Available We propose a miniaturised light stage for measuring the bidirectional reflectance distribution function (BRDF and the bidirectional texture function (BTF of surfaces on site in real world application scenarios. The main principle of our lightweight BTF acquisition gantry is a compact hemispherical skeleton with cameras along the meridian and with light emitting diode (LED modules shining light onto a sample surface. The proposed device is portable and achieves a high speed of measurement while maintaining high degree of accuracy. While the positions of the LEDs are fixed on the hemisphere, the cameras allow us to cover the range of the zenith angle from 0 ∘ to 75 ∘ and by rotating the cameras along the axis of the hemisphere we can cover all possible camera directions. This allows us to take measurements with almost the same quality as existing stationary BTF gantries. Two degrees of freedom can be set arbitrarily for measurements and the other two degrees of freedom are fixed, which provides a tradeoff between accuracy of measurements and practical applicability. Assuming that a measured sample is locally flat and spatially accessible, we can set the correct perpendicular direction against the measured sample by means of an auto-collimator prior to measuring. Further, we have designed and used a marker sticker method to allow for the easy rectification and alignment of acquired images during data processing. We show the results of our approach by images rendered for 36 measured material samples.

  16. Lightdrum—Portable Light Stage for Accurate BTF Measurement on Site

    Science.gov (United States)

    Havran, Vlastimil; Hošek, Jan; Němcová, Šárka; Čáp, Jiří; Bittner, Jiří

    2017-01-01

    We propose a miniaturised light stage for measuring the bidirectional reflectance distribution function (BRDF) and the bidirectional texture function (BTF) of surfaces on site in real world application scenarios. The main principle of our lightweight BTF acquisition gantry is a compact hemispherical skeleton with cameras along the meridian and with light emitting diode (LED) modules shining light onto a sample surface. The proposed device is portable and achieves a high speed of measurement while maintaining high degree of accuracy. While the positions of the LEDs are fixed on the hemisphere, the cameras allow us to cover the range of the zenith angle from 0∘ to 75∘ and by rotating the cameras along the axis of the hemisphere we can cover all possible camera directions. This allows us to take measurements with almost the same quality as existing stationary BTF gantries. Two degrees of freedom can be set arbitrarily for measurements and the other two degrees of freedom are fixed, which provides a tradeoff between accuracy of measurements and practical applicability. Assuming that a measured sample is locally flat and spatially accessible, we can set the correct perpendicular direction against the measured sample by means of an auto-collimator prior to measuring. Further, we have designed and used a marker sticker method to allow for the easy rectification and alignment of acquired images during data processing. We show the results of our approach by images rendered for 36 measured material samples. PMID:28241466

  17. Calibration method for accurate optical measurement of thickness profile for the paper industry

    Science.gov (United States)

    Graeffe, Jussi

    2009-06-01

    Online measurement of paper thickness profile is essential in paper production. For decades paper thickness has been measured online with sensors that are contacting the web on both sides. In 2005 a new optical online paper thickness gauge was introduced which only contacts the web on the other side. The sensor is based on a laser triangulation sensor and a magnetic sensor, and it determines the paper thickness from the difference of the two measurements. For calibration of the two sensors, a robust concept has been developed which utilizes the measured object and takes place in the measuring environment so that the calibration is automatically adjusted to the current measuring circumstances. More importantly, with the presented method the non-linearity of the laser sensor is cancelled enabling the measurement of the thickness profile shape with an accuracy much better than that of the laser sensor. Profile accuracy of 0.5 μm (2σ) has become normal while the measuring range is often several hundreds of microns and the measuring distance to the paper web 1.0-1.5 mm with a laser sensor having linearity of +/-2 μm.

  18. Surface EMG measurements during fMRI at 3T : Accurate EMG recordings after artifact correction

    NARCIS (Netherlands)

    van Duinen, Hiske; Zijdewind, Inge; Hoogduin, H; Maurits, N

    2005-01-01

    In this experiment, we have measured surface EMG of the first dorsal interosseus during predefined submaximal isometric contractions (5, 15, 30, 50, and 70% of maximal force) of the index finger simultaneously with fMRI measurements. Since we have used sparse sampling fMRI (3-s scanning; 2-s

  19. Archimedes Revisited: A Faster, Better, Cheaper Method of Accurately Measuring the Volume of Small Objects

    Science.gov (United States)

    Hughes, Stephen W.

    2005-01-01

    A little-known method of measuring the volume of small objects based on Archimedes' principle is described, which involves suspending an object in a water-filled container placed on electronic scales. The suspension technique is a variation on the hydrostatic weighing technique used for measuring volume. The suspension method was compared with two…

  20. Method of accurate thickness measurement of boron carbide coating on copper foil

    Energy Technology Data Exchange (ETDEWEB)

    Lacy, Jeffrey L.; Regmi, Murari

    2017-11-07

    A method is disclosed of measuring the thickness of a thin coating on a substrate comprising dissolving the coating and substrate in a reagent and using the post-dissolution concentration of the coating in the reagent to calculate an effective thickness of the coating. The preferred method includes measuring non-conducting films on flexible and rough substrates, but other kinds of thin films can be measure by matching a reliable film-substrate dissolution technique. One preferred method includes determining the thickness of Boron Carbide films deposited on copper foil. The preferred method uses a standard technique known as inductively coupled plasma optical emission spectroscopy (ICPOES) to measure boron concentration in a liquid sample prepared by dissolving boron carbide films and the Copper substrates, preferably using a chemical etch known as ceric ammonium nitrate (CAN). Measured boron concentration values can then be calculated.

  1. Accurate on-chip measurement of the Seebeck coefficient of high mobility small molecule organic semiconductors

    Directory of Open Access Journals (Sweden)

    C. N. Warwick

    2015-09-01

    Full Text Available We present measurements of the Seebeck coefficient in two high mobility organic small molecules, 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT and 2,9-didecyl-dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (C10-DNTT. The measurements are performed in a field effect transistor structure with high field effect mobilities of approximately 3 cm2/V s. This allows us to observe both the charge concentration and temperature dependence of the Seebeck coefficient. We find a strong logarithmic dependence upon charge concentration and a temperature dependence within the measurement uncertainty. Despite performing the measurements on highly polycrystalline evaporated films, we see an agreement in the Seebeck coefficient with modelled values from Shi et al. [Chem. Mater. 26, 2669 (2014] at high charge concentrations. We attribute deviations from the model at lower charge concentrations to charge trapping.

  2. Novel methodology for accurate resolution of fluid signatures from multi-dimensional NMR well-logging measurements

    Science.gov (United States)

    Anand, Vivek

    2017-03-01

    A novel methodology for accurate fluid characterization from multi-dimensional nuclear magnetic resonance (NMR) well-logging measurements is introduced. This methodology overcomes a fundamental challenge of poor resolution of features in multi-dimensional NMR distributions due to low signal-to-noise ratio (SNR) of well-logging measurements. Based on an unsupervised machine-learning concept of blind source separation, the methodology resolves fluid responses from simultaneous analysis of large quantities of well-logging data. The multi-dimensional NMR distributions from a well log are arranged in a database matrix that is expressed as the product of two non-negative matrices. The first matrix contains the unique fluid signatures, and the second matrix contains the relative contributions of the signatures for each measurement sample. No a priori information or subjective assumptions about the underlying features in the data are required. Furthermore, the dimensionality of the data is reduced by several orders of magnitude, which greatly simplifies the visualization and interpretation of the fluid signatures. Compared to traditional methods of NMR fluid characterization which only use the information content of a single measurement, the new methodology uses the orders-of-magnitude higher information content of the entire well log. Simulations show that the methodology can resolve accurate fluid responses in challenging SNR conditions. The application of the methodology to well-logging data from a heavy oil reservoir shows that individual fluid signatures of heavy oil, water associated with clays and water in interstitial pores can be accurately obtained.

  3. Defining Allowable Physical Property Variations for High Accurate Measurements on Polymer Parts

    DEFF Research Database (Denmark)

    Mohammadi, Ali; Sonne, Mads Rostgaard; Madruga, Daniel González

    2015-01-01

    Measurement conditions and material properties have a significant impact on the dimensions of a part, especially for polymers parts. Temperature variation causes part deformations that increase the uncertainty of the measurement process. Current industrial tolerances of a few micrometres demand h....... In this paper, we investigated how big the variation in material and physical properties are allowed in order to reach the 5 μm target on the uncertainty....

  4. External urethral sphincter pressure measurement: an accurate method for the diagnosis of detrusor external sphincter dyssynergia?

    Directory of Open Access Journals (Sweden)

    Carlos H Suzuki Bellucci

    Full Text Available Combined pelvic floor electromyography (EMG and videocystourethrography (VCUG during urodynamic investigation are the most acceptable and widely agreed methods for diagnosing detrusor external sphincter dyssynergia (DESD. Theoretically, external urethral sphincter pressure (EUSP measurement would provide enough information for the diagnosis of DESD and could simplify the urodynamic investigation replacing combined pelvic floor EMG and VCUG. Thus, we evaluated the diagnostic accuracy of EUSP measurement for DESD. PATIENTS #ENTITYSTARTX00026;A consecutive series of 72 patients (36 women, 36 men with neurogenic lower urinary tract dysfunction able to void spontaneously was prospectively evaluated at a single university spinal cord injury center. Diagnosis of DESD using EUSP measurement (index test versus combined pelvic floor EMG and VCUG (reference standard was assessed according to the recommendations of the Standards for Reporting of Diagnostic Accuracy Initiative.Using EUSP measurement (index test and combined pelvic floor EMG and VCUR (reference standard, DESD was diagnosed in 10 (14% and in 41 (57% patients, respectively. More than half of the patients presented discordant diagnosis between the index test and the reference standard. Among 41 patients with DESD diagnosed by combined pelvic floor EMG and VCUR, EUSP measurement identified only 6 patients. EUSP measurement had a sensitivity of 15% (95% CI 5%-25%, specificity of 87% (95% CI 76%-98%, positive predictive value of 60% (95% CI 30%-90%, and negative predictive value of 56% (95% CI 44%-68% for the diagnosis of DESD.For diagnosis of DESD, EUSP measurement is inaccurate and cannot replace combined pelvic floor EMG and VCUR.

  5. Extrapolation of urn models via poissonization: accurate measurements of the microbial unknown.

    Directory of Open Access Journals (Sweden)

    Manuel E Lladser

    Full Text Available The availability of high-throughput parallel methods for sequencing microbial communities is increasing our knowledge of the microbial world at an unprecedented rate. Though most attention has focused on determining lower-bounds on the α-diversity i.e. the total number of different species present in the environment, tight bounds on this quantity may be highly uncertain because a small fraction of the environment could be composed of a vast number of different species. To better assess what remains unknown, we propose instead to predict the fraction of the environment that belongs to unsampled classes. Modeling samples as draws with replacement of colored balls from an urn with an unknown composition, and under the sole assumption that there are still undiscovered species, we show that conditionally unbiased predictors and exact prediction intervals (of constant length in logarithmic scale are possible for the fraction of the environment that belongs to unsampled classes. Our predictions are based on a poissonization argument, which we have implemented in what we call the Embedding algorithm. In fixed i.e. non-randomized sample sizes, the algorithm leads to very accurate predictions on a sub-sample of the original sample. We quantify the effect of fixed sample sizes on our prediction intervals and test our methods and others found in the literature against simulated environments, which we devise taking into account datasets from a human-gut and -hand microbiota. Our methodology applies to any dataset that can be conceptualized as a sample with replacement from an urn. In particular, it could be applied, for example, to quantify the proportion of all the unseen solutions to a binding site problem in a random RNA pool, or to reassess the surveillance of a certain terrorist group, predicting the conditional probability that it deploys a new tactic in a next attack.

  6. Three dimensional accurate morphology measurements of polystyrene standard particles on silicon substrate by electron tomography.

    Science.gov (United States)

    Hayashida, Misa; Kumagai, Kazuhiro; Malac, Marek

    2015-12-01

    Polystyrene latex (PSL) nanoparticle (NP) sample is one of the most widely used standard materials. It is used for calibration of particle counters and particle size measurement tools. It has been reported that the measured NP sizes by various methods, such as Differential Mobility Analysis, dynamic light scattering (DLS), optical microscopy (OM), scanning electron microscopy (SEM) and atomic force microscopy (AFM), differ from each other. Deformation of PSL NPs on mica substrate has been reported in AFM measurements: the lateral width of PSL NPs is smaller than their vertical height. To provide a reliable calibration standard, the deformation must be measured by a method that can reliably visualize the entire three dimensional (3D) shape of the PSL NPs. Here we present a method for detailed measurement of PSL NP 3D shape by means of electron tomography in a transmission electron microscope. The observed shape of the PSL NPs with 100 nm and 50 nm diameter were not spherical, but squished in direction perpendicular to the support substrate by about 7.4% and 12.1%, respectively. The high difference in surface energy of the PSL NPs and that of substrate together with their low Young modulus appear to explain the squishing of the NPs without presence of water film. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  7. Accurate Measurement of First Metatarsophalangeal Range of Motion in Patients With Hallux Rigidus.

    Science.gov (United States)

    Vulcano, Ettore; Tracey, Joseph A; Myerson, Mark S

    2016-05-01

    The reliability of range of motion (ROM) measurements has not been established for the hallux metatarsophalangeal (MTP) joint in patients with hallux rigidus. The aim of the present study was to prospectively assess the clinical versus radiographic difference in ROM of the arthritic hallux MTP joint. One hundred consecutive patients who presented with any grade of hallux rigidus were included in this prospective study to determine the hallux MTP range of motion. Clinical range of motion using a goniometer and radiographic range of motion on dynamic x-rays was recorded. The mean difference between clinical and radiographic dorsiflexion was 13 degrees (P dorsiflexion was equal to or less than radiographically measured dorsiflexion. The difference was significantly greater in patients with a clinical dorsiflexion of less than 30 degrees than in patients with 30 degrees or more. Radiographic measurement of hallux dorsiflexion had an excellent intra- and interobserver reliability. We describe a reliable, reproducible, and straightforward method of measuring hallux MTP ROM that improved upon measuring clinical ROM. Level II, prospective comparative study. © The Author(s) 2015.

  8. Accurate measurement of nanoparticle charge, number and size with the ELPI+{sup TM} instrument

    Energy Technology Data Exchange (ETDEWEB)

    Lamminen, Erkki, E-mail: erkki.lamminen@dekati.fi [Osuusmyllynkatu 13, 33700 Tampere (Finland)

    2011-07-06

    Nanoparticle characterization is mainly carried out by microscopy techniques and measurements of size and concentration. However to be able to comprehensively understand the behavior of the aerosol, information on particle charge level is critical. Particle charge has a major effect on the coagulation, deposition and transport as well as on the health effects of the particles. While aged aerosols generally are mainly neutral in terms of charge, freshly generated or resuspended particles can have high charge levels that vary depending on the size, material and generation method of the particles. Charging processes for particles are problematic as they are usually both time dependent and material dependent with sudden changes in magnitude. This makes the charge of a particle nearly impossible to predict without detailed studies and direct measurements. ELPI+{sup TM} instrument is a completely new aerosol measurement instrument based on the widely used Electrical Low Pressure Impactor (ELPI) technique. ELPI+{sup TM} measures particle concentration and size in a wide size range from 6nm to 10{mu}m in real-time. The operation is based on first charging the particles in a corona charger and then size segregating them in a cascade impactor where all impactor stages are electrically insulated. With the ELPI+{sup TM} instrument it is possible to measure not only the particle size and concentration in real-time, but also the charge distribution of the particles. As the particle size classification is made with an impactor, the measured particles can be subsequently analyzed if needed with a suitable technique.

  9. Accurate measurement of nanoparticle charge, number and size with the ELPI+™ instrument

    Science.gov (United States)

    Lamminen, Erkki

    2011-07-01

    Nanoparticle characterization is mainly carried out by microscopy techniques and measurements of size and concentration. However to be able to comprehensively understand the behavior of the aerosol, information on particle charge level is critical. Particle charge has a major effect on the coagulation, deposition and transport as well as on the health effects of the particles. While aged aerosols generally are mainly neutral in terms of charge, freshly generated or resuspended particles can have high charge levels that vary depending on the size, material and generation method of the particles. Charging processes for particles are problematic as they are usually both time dependent and material dependent with sudden changes in magnitude. This makes the charge of a particle nearly impossible to predict without detailed studies and direct measurements. ELPI+™ instrument is a completely new aerosol measurement instrument based on the widely used Electrical Low Pressure Impactor (ELPI) technique. ELPI+™ measures particle concentration and size in a wide size range from 6nm to 10μm in real-time. The operation is based on first charging the particles in a corona charger and then size segregating them in a cascade impactor where all impactor stages are electrically insulated. With the ELPI+™ instrument it is possible to measure not only the particle size and concentration in real-time, but also the charge distribution of the particles. As the particle size classification is made with an impactor, the measured particles can be subsequently analyzed if needed with a suitable technique.

  10. Accurate determination of gain and radiation patterns by radar cross-section measurements

    DEFF Research Database (Denmark)

    Appel-Hansen, Jørgen

    1979-01-01

    Using a two-port network and geometrical interpretation of equations involved in antenna scattering, it can be derived that antenna characteristics may be determined in properly designed scattering measurements. As an alternative to this approach it is shown that measurement procedures for gain...... and radiation pattern can be developed from simple considerations of the receiving, transmitting, and scattering properties of antennas. The main advantages of the technique are that no gain standard is required and a disturbing feedline to the antenna can be avoided. In addition to this the technique seems...

  11. A flux monitoring method for easy and accurate flow rate measurement in pressure-driven flows.

    Science.gov (United States)

    Siria, Alessandro; Biance, Anne-Laure; Ybert, Christophe; Bocquet, Lydéric

    2012-03-07

    We propose a low-cost and versatile method to measure flow rate in microfluidic channels under pressure-driven flows, thereby providing a simple characterization of the hydrodynamic permeability of the system. The technique is inspired by the current monitoring method usually employed to characterize electro-osmotic flows, and makes use of the measurement of the time-dependent electric resistance inside the channel associated with a moving salt front. We have successfully tested the method in a micrometer-size channel, as well as in a complex microfluidic channel with a varying cross-section, demonstrating its ability in detecting internal shape variations.

  12. Integrating sphere-based setup as an accurate system for optical properties measurements

    CSIR Research Space (South Africa)

    Abdalmonem, S

    2010-09-01

    Full Text Available Determination of the optical properties of solid and liquid samples has great importance. Since the integrating sphere-based setup is used to measure the amount of reflected and transmitted light by the examined samples, optical properties could...

  13. An accurate method for power loss measurements in energy optimized apparatus and systems

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, P.; Blaabjerg, F.; Madsen, K.D.; Pedersen, J.K.; Ritchie, E.

    2001-07-01

    A calorimetric wattmeter has been built at Aalborg University, Institute of Energy Technology. The wattmeter is designed to measure power losses in power electronic components and applications at fixed temperatures. High accuracy has been achieved by using active constraints and optimizing flow and temperature conditions in the cooling circuit. (au)

  14. New insights for accurate chemically specific measurements of slow diffusing molecules

    Science.gov (United States)

    Hou, Jianbo; Madsen, Louis A.

    2013-02-01

    Investigating the myriad features of molecular transport in materials yields fundamental information for understanding processes such as ion conduction, chemical reactions, and phase transitions. Molecular transport especially impacts the performance of ion-containing liquids and polymeric materials when used as electrolytes and separation media, with applications encompassing battery electrolytes, reverse-osmosis membranes, mechanical transducers, and fuel cells. Nuclear magnetic resonance (NMR) provides a unique probe of molecular translations by allowing measurement of all mobile species via spectral selectivity, access to a broad range of transport coefficients, probing of any material direction, and investigation of variable lengthscales in a material, thus, tying morphology to transport. Here, we present new concepts to test for and guarantee robust diffusion measurements. We first employ a standard pulsed-field-gradient (PFG) calibration protocol using 2H2O and obtain expected results, but we observe crippling artifacts when measuring 1H-glycerol diffusion with the same experimental parameters. A mathematical analysis of 2H2O and glycerol signals in the presence of PFG transients show tight agreement with experimental observations. These analyses lead to our principal findings that (1) negligible artifacts observed with low gyromagnetic ratio (γ) nuclei may become dominant when observing high γ nuclei, and (2) reducing the sample dimension along the gradient direction predictably reduces non-ideal behaviors of NMR signals. We further provide a useful quantitative strategy for error minimization when measuring diffusing species slower than the one used for gradient calibration.

  15. Do plant traits retrieved from a database accurately predict on-site measurements?

    NARCIS (Netherlands)

    Cordlandwehr, V.; Meredith, R.L.; Ozinga, W.A.; Bekker, R.M.; Groenendael, van J.M.; Bakker, J.P.

    2013-01-01

    1. Trait-based approaches are increasingly used to obtain an insight into the functional aspects of plant communities. Since measuring traits can be time-consuming, large international databases of plant traits are being compiled to share the effort. From these databases, average trait values are

  16. Do plant traits retrieved from a database accurately predict on-site measurements?

    NARCIS (Netherlands)

    Cordlandwehr, Verena; Meredith, Rebecca L.; Ozinga, Wim A.; Bekker, Renée M.; van Groenendael, Jan M.; Bakker, Jan P.

    Trait-based approaches are increasingly used to obtain an insight into the functional aspects of plant communities. Since measuring traits can be time-consuming, large international databases of plant traits are being compiled to share the effort. From these databases, average trait values are often

  17. Optical coherence tomography enables accurate measurement of equine cartilage thickness for determination of speed of sound

    NARCIS (Netherlands)

    Puhakka, Pia H.; te Moller, Nikae; Tanska, Petri; Saarakkala, Simo; Tiitu, Virpi; Korhonen, Rami K.; Brommer, Harold; Virén, Tuomas; Jurvelin, Jukka S.; Töyräs, Juha

    2016-01-01

    Background and purpose — Arthroscopic estimation of articular cartilage thickness is important for scoring of lesion severity, and measurement of cartilage speed of sound (SOS)—a sensitive index of changes in cartilage composition. We investigated the accuracy of optical coherence tomography (OCT)

  18. Fast and Accurate Collocation of the Visible Infrared Imaging Radiometer Suite Measurements with Cross-Track Infrared Sounder

    Directory of Open Access Journals (Sweden)

    Likun Wang

    2016-01-01

    Full Text Available Given the fact that Cross-track Infrared Sounder (CrIS and the Visible Infrared Imaging Radiometer Suite (VIIRS are currently onboard the Suomi National Polar-orbiting Partnership (Suomi NPP satellite and will continue to be carried on the same platform as future Joint Polar Satellite System (JPSS satellites for the next decade, it is desirable to develop a fast and accurate collocation scheme to collocate VIIRS products and measurements with CrIS for applications that rely on combining measurements from two sensors such as inter-calibration, geolocation assessment, and cloud detection. In this study, an accurate and fast collocation method to collocate VIIRS measurements within CrIS instantaneous field of view (IFOV directly based on line-of-sight (LOS pointing vectors is developed and discussed in detail. We demonstrate that this method is not only accurate and precise from a mathematical perspective, but also easy to implement computationally. More importantly, with optimization, this method is very fast and efficient and thus can meet operational requirements. Finally, this collocation method can be extended to a wide variety of sensors on different satellite platforms.

  19. Recombinant albumin adsorption on mica studied by AFM and streaming potential measurements.

    Science.gov (United States)

    Kujda, Marta; Adamczyk, Zbigniew; Morga, Maria; Sofińska, Kamila

    2015-03-01

    Recombinant human serum albumin (rHSA) in monomeric state is widely used in pharmaceutical industry as a drug excipient and for preparing coatings for medical devices. In this work the adsorption process of rHSA on model mica surface at pH 3.5 was studied using the atomic force microscopy (AFM) and in situ streaming potential measurements. The kinetics of albumin adsorption was determined by a direct enumeration of single molecules over various substrate areas. These results were consistent with streaming potential measurements carried out for the parallel-plate channel flow and with theoretical predictions derived from the random sequential adsorption (RSA) model. Desorption kinetics of albumin under flow conditions was also evaluated via the streaming potential measurements. In this way, the amount of irreversibly bound albumin was quantitatively evaluated to be 0.64 and 1.2 mg m(-2) for ionic strength of 0.01 and 0.15 M, respectively. This agrees with previous results obtained for HSA and theoretical calculations derived from the RSA model. Additionally, it was demonstrated that there existed a fraction of reversibly bound albumin that can be fully eluted within a few hours. The binding energy of these fraction of molecules was -18 kT that is consistent with the electrostatic controlled adsorption mechanism of albumin at this pH. It was concluded that the rHSA monolayers of well-defined coverage can find applications for quantitatively analyzing ligand binding and for performing efficient biomaterials and immunological tests. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. First measurement of the edge charge exchange recombination spectroscopy on EAST tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y. Y., E-mail: liyy@ipp.ac.cn; Fu, J.; Jiang, D.; Lyu, B.; Hu, C. D.; Wan, B. N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Yin, X. H.; Feng, S. Y. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); School of Nuclear Science and Technology, University of Science and Technology of China, Hefei (China); Shi, Y. J. [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei (China); Department of Nuclear Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Yi, Y.; Ye, M. Y. [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei (China); Zhou, X. J. [Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-11-15

    An edge toroidal charge exchange recombination spectroscopy (eCXRS) diagnostic, based on a heating neutral beam injection (NBI), has been deployed recently on the Experimental Advanced Superconducting Tokamak (EAST). The eCXRS, which aims to measure the plasma ion temperature and toroidal rotation velocity in the edge region simultaneously, is a complement to the exiting core CXRS (cCXRS). Two rows with 32 fiber channels each cover a radial range from ∼2.15 m to ∼2.32 m with a high spatial resolution of ∼5-7 mm. Charge exchange emission of Carbon VI CVI at 529.059 nm induced by the NBI is routinely observed, but can be tuned to any interested wavelength in the spectral range from 400 to 700 nm. Double-slit fiber bundles increase the number of channels, the fibers viewing the same radial position are binned on the CCD detector to improve the signal-to-noise ratio, enabling shorter exposure time down to 5 ms. One channel is connected to a neon lamp, which provides the real-time wavelength calibration on a shot-to-shot basis. In this paper, an overview of the eCXRS diagnostic on EAST is presented and the first results from the 2015 experimental campaign will be shown. Good agreements in ion temperature and toroidal rotation are obtained between the eCXRS and cCXRS systems.

  1. A Procedure for Accurately Measuring the Shaker Overturning Moment During Random Vibration Tests

    Science.gov (United States)

    Nayeri, Reza D.

    2011-01-01

    Motivation: For large system level random vibration tests, there may be some concerns about the shaker's capability for the overturning moment. It is the test conductor's responsibility to predict and monitor the overturning moment during random vibration tests. If the predicted moment is close to the shaker's capability, test conductor must measure the instantaneous moment at low levels and extrapolate to higher levels. That data will be used to decide whether it is safe to proceed to the next test level. Challenge: Kistler analog formulation for computing the real-time moment is only applicable to very limited cases in which we have 3 or 4 load cells installed at shaker interface with hardware. Approach: To overcome that limitation, a simple procedure was developed for computing the overturning moment time histories using the measured time histories of the individual load cells.

  2. Development of a scattering probability method for accurate vapor fraction measurements by neutron radiography

    CERN Document Server

    Joo, H

    1999-01-01

    Recent test results indicated drawbacks associated with the simple exponential attenuation method (SEAM) as currently applied to neutron radiography measurements to determine vapor fractions in a hydrogenous two-phase flow in a metallic conduit. The scattering component of the neutron beam intensity exiting the flow system is not adequately accounted for by SEAM, and this leads to inaccurate results. To properly account for the scattering effect, a neutron scattering probability method (SPM) is developed. The method applies a neutron-hydrogen scattering kernel to scattered thermal neutrons that leave the incident beam in narrow conduits but eventually show up elsewhere in the measurements. The SPM has been tested with known vapor (void) distributions within an acrylic disk and a water/vapor channel. The vapor (void) fractions deduced by SPM are in good agreement with the known exact values. Details of the scattering correction method and the test results are discussed.

  3. Measuring Accurately Single-Phase Sinusoidal and Non-Sinusoidal Power.

    Science.gov (United States)

    1983-01-01

    made by the voltage and current circuits. The two methods for connecting the Model 255 wattmeter for measuring power arc shown in figure 6.1(a) and 6.1(b...insertion losses due to the physical connections made by the voltage and current- coil circuits. The two method :, for connecting the P-3 wattmeter for...P-3 Electrodynamometer wattmeters , two Clarke-Hess Model 255 Digital Wattmeters and one General Electric Type VM- 63-S Induction Watthour Meter. The

  4. Digital Integrator for Fast Accurate Measurement of Magnetic Flux by Rotating Coils

    CERN Document Server

    Arpaia, P.; Spiezia, G.

    2007-01-01

    A fast digital integrator (FDI) with dynamic accuracy and a trigger frequency higher than those of a portable digital integrator (PDI), which is a state-of-the-art instrument for magnetic measurements based on rotating coils, was developed for analyzing superconducting magnets in particle accelerators. Results of static and dynamic metrological characterization show how the FDI prototype is already capable of overcoming the dynamic performance of PDI as well as covering operating regions that used to be inaccessible

  5. An X-band waveguide measurement technique for the accurate characterization of materials with low dielectric loss permittivity.

    Science.gov (United States)

    Allen, Kenneth W; Scott, Mark M; Reid, David R; Bean, Jeffrey A; Ellis, Jeremy D; Morris, Andrew P; Marsh, Jeramy M

    2016-05-01

    In this work, we present a new X-band waveguide (WR90) measurement method that permits the broadband characterization of the complex permittivity for low dielectric loss tangent material specimens with improved accuracy. An electrically long polypropylene specimen that partially fills the cross-section is inserted into the waveguide and the transmitted scattering parameter (S21) is measured. The extraction method relies on computational electromagnetic simulations, coupled with a genetic algorithm, to match the experimental S21 measurement. The sensitivity of the technique to sample length was explored by simulating specimen lengths from 2.54 to 15.24 cm, in 2.54 cm increments. Analysis of our simulated data predicts the technique will have the sensitivity to measure loss tangent values on the order of 10(-3) for materials such as polymers with relatively low real permittivity values. The ability to accurately characterize low-loss dielectric material specimens of polypropylene is demonstrated experimentally. The method was validated by excellent agreement with a free-space focused-beam system measurement of a polypropylene sheet. This technique provides the material measurement community with the ability to accurately extract material properties of low-loss material specimen over the entire X-band range. This technique could easily be extended to other frequency bands.

  6. A technique for fast and accurate measurement of hand volumes using Archimedes' principle.

    Science.gov (United States)

    Hughes, S; Lau, J

    2008-03-01

    A new technique for measuring hand volumes using Archimedes principle is described. The technique involves the immersion of a hand in a water container placed on an electronic balance. The volume is given by the change in weight divided by the density of water. This technique was compared with the more conventional technique of immersing an object in a container with an overflow spout and collecting and weighing the volume of overflow water. The hand volume of two subjects was measured. Hand volumes were 494 +/- 6 ml and 312 +/- 7 ml for the immersion method and 476 +/- 14 ml and 302 +/- 8 ml for the overflow method for the two subjects respectively. Using plastic test objects, the mean difference between the actual and measured volume was -0.3% and 2.0% for the immersion and overflow techniques respectively. This study shows that hand volumes can be obtained more quickly than the overflow method. The technique could find an application in clinics where frequent hand volumes are required.

  7. A Robust Method of Vehicle Stability Accurate Measurement Using GPS and INS

    Directory of Open Access Journals (Sweden)

    Miao Zhibin

    2015-12-01

    Full Text Available With the development of the vehicle industry, controlling stability has become more and more important. Techniques of evaluating vehicle stability are in high demand. Integration of Global Positioning System (GPS and Inertial Navigation System (INS is a very practical method to get high-precision measurement data. Usually, the Kalman filter is used to fuse the data from GPS and INS. In this paper, a robust method is used to measure vehicle sideslip angle and yaw rate, which are two important parameters for vehicle stability. First, a four-wheel vehicle dynamic model is introduced, based on sideslip angle and yaw rate. Second, a double level Kalman filter is established to fuse the data from Global Positioning System and Inertial Navigation System. Then, this method is simulated on a sample vehicle, using Carsim software to test the sideslip angle and yaw rate. Finally, a real experiment is made to verify the advantage of this approach. The experimental results showed the merits of this method of measurement and estimation, and the approach can meet the design requirements of the vehicle stability controller.

  8. Regular, Fast and Accurate Airborne In-Situ Methane Measurements Around the Tropopause

    Science.gov (United States)

    Dyroff, Christoph; Rauthe-Schöch, Armin; Schuck, Tanja J.; Zahn, Andreas

    2013-04-01

    We present a laser spectrometer for automated monthly measurements of methane (CH4) mixing ratios aboard the CARIBIC passenger aircraft. The instrument is based on a commercial fast methane analyzer (FMA, Los Gatos Res.), which was modified for fully unattended employment. A laboratory characterization was performed and the results with emphasis on the precision, cross sensitivity to H2O, and accuracy are presented. An in-flight calibration strategy is described, that utilizes CH4 measurements obtained from flask samples taken during the same flights. By statistical comparison of the in-situ measurements with the flask samples we derive a total uncetrainty estimate of ~ 3.85 ppbv (1?) around the tropopause, and ~ 12.4 ppbv (1?) during aircraft ascent and descent. Data from the first two years of airborne operation are presented that span a large part of the northern hemispheric upper troposphere and lowermost stratosphere, with occasional crossings of the tropics on flights to southern Africa. With its high spatial resolution and high accuracy this data set is unprecedented in the highly important atmospheric layer of the tropopause.

  9. Comprehensive and Highly Accurate Measurements of Crane Runways, Profiles and Fastenings.

    Science.gov (United States)

    Dennig, Dirk; Bureick, Johannes; Link, Johannes; Diener, Dmitri; Hesse, Christian; Neumann, Ingo

    2017-05-13

    The process of surveying crane runways has been continually refined due to the competitive situation, modern surveying instruments, additional sensors, accessories and evaluation procedures. Guidelines, such as the International Organization for Standardization (ISO) 12488-1, define target values that must be determined by survey. For a crane runway these are for example the span, the position and height of the rails. The process has to be objective and reproducible. However, common processes of surveying crane runways do not meet these requirements sufficiently. The evaluation of the protocols, ideally by an expert, requires many years of experience. Additionally, the recording of crucial parameters, e.g., the wear of the rail, or the condition of the rail fastening and rail joints, is not regulated and for that reason are often not considered during the measurement. To solve this deficit the Advanced Rail Track Inspection System (ARTIS) was developed. ARTIS is used to measure the 3D position of crane rails, the cross-section of the crane rails, joints and, for the first time, the (crane-rail) fastenings. The system consists of a monitoring vehicle and an external tracking sensor. It makes kinematic observations with the tracking sensor from outside the rail run, e.g., the floor of an overhead crane runway, possible. In this paper we present stages of the development process of ARTIS, new target values, calibration of sensors and results of a test measurement.

  10. Examining factors that may influence accurate measurement of testosterone in sea turtles.

    Science.gov (United States)

    Graham, Katherine M; Mylniczenko, Natalie D; Burns, Charlene M; Bettinger, Tammie L; Wheaton, Catharine J

    2016-01-01

    Differences in reported testosterone concentrations in male sea turtle blood samples are common in the veterinary literature, but may be accounted for by differences in sample handling and processing prior to assay. Therefore, our study was performed to determine best practices for testosterone analysis in male sea turtles (Caretta caretta and Chelonia mydas). Blood samples were collected into 5 collection tube types, and assay validation and measured testosterone concentrations were compared across different sample storage (fresh, refrigerated 1 week, or frozen), extraction (unextracted or ether-extracted), and processing treatment (untreated, homogenized, or dissociation reagent) conditions. Ether-extracted and dissociation reagent-treated samples validated in all conditions tested and are recommended for use, as unextracted samples validated only if assayed fresh. Dissociation reagent treatment was simpler to perform than ether extraction and resulted in total testosterone concentrations ~2.7-3.5 times greater than free testosterone measured in ether-extracted samples. Sample homogenization did not affect measured testosterone concentrations, and could be used to increase volume in gelled samples. An annual seasonal testosterone increase was observed in both species when ether extraction or dissociation reagent treatment was used. Annual deslorelin implant treatments in a Chelonia mydas male resulted in suppression of seasonal testosterone following the fourth treatment. Seasonal testosterone patterns resumed following discontinuation of deslorelin. Comparison of in-house and commercially available enzyme immunoassay kits revealed similar patterns of seasonal testosterone increases and deslorelin-induced suppression. Our study highlights the importance of methodological validation and provides laboratorians with best practices for testosterone enzyme immunoassay in sea turtles. © 2015 The Author(s).

  11. Fast and Accurate Face Orientation Measurement in Low-resolution Images on Embedded Hardware

    OpenAIRE

    Hulens, Dries; Van Beeck, Kristof; Goedemé, Toon

    2016-01-01

    In numerous applications it is important to collect information about the gaze orientation or head-angle of a person. Examples are measuring the alertness of a car driver to see if he is still awake, or the attentiveness of people crossing a street to see if they noticed the cars driving by. In our own application we want to apply cinematographic rules (e.g. the rule of thirds where a face should be positioned left or right in the frame depending on the gaze direction) on images taken from an...

  12. Possibility of detecting anisotropic expansion of the universe by very accurate astrometry measurements.

    Science.gov (United States)

    Quercellini, Claudia; Quartin, Miguel; Amendola, Luca

    2009-04-17

    Refined astrometry measurements allow us to detect large-scale deviations from isotropy through real-time observations of changes in the angular separation between sources at cosmic distances. This "cosmic parallax" effect is a powerful consistency test of the Friedmann-Robertson-Walker metric and may set independent constraints on cosmic anisotropy. We apply this novel general test to Lemaitre-Tolman-Bondi cosmologies with off-center observers and show that future satellite missions such as Gaia might achieve accuracies that would put limits on the off-center distance which are competitive with cosmic microwave background dipole constraints.

  13. Progress on accurate measurement of the Planck constant: watt balance and counting atoms

    OpenAIRE

    Li, Shisong; Zhang, Zhonghua; Zhao, Wei; Li, Zhengkun; Huang, Songling

    2014-01-01

    The Planck constant $h$ is one of the most significant constants in quantum physics. Recently, the precision measurement of the numeral value of $h$ has been a hot issue due to its important role in establishment for both a new SI and a revised fundamental physical constant system. Up to date, two approaches, the watt balance and counting atoms, have been employed to determine the Planck constant at a level of several parts in $10^8$. In this paper, the principle and progress on precision mea...

  14. Accurate low-rank matrix recovery from a small number of linear measurements

    CERN Document Server

    Candes, Emmanuel J

    2009-01-01

    We consider the problem of recovering a lowrank matrix M from a small number of random linear measurements. A popular and useful example of this problem is matrix completion, in which the measurements reveal the values of a subset of the entries, and we wish to fill in the missing entries (this is the famous Netflix problem). When M is believed to have low rank, one would ideally try to recover M by finding the minimum-rank matrix that is consistent with the data; this is, however, problematic since this is a nonconvex problem that is, generally, intractable. Nuclear-norm minimization has been proposed as a tractable approach, and past papers have delved into the theoretical properties of nuclear-norm minimization algorithms, establishing conditions under which minimizing the nuclear norm yields the minimum rank solution. We review this spring of emerging literature and extend and refine previous theoretical results. Our focus is on providing error bounds when M is well approximated by a low-rank matrix, and ...

  15. Accurate Profile Measurement of the low Intensity Secondary Beams in the CERN Experimental Areas

    CERN Document Server

    AUTHOR|(CDS)2084531; Tranquille, Gerard

    2018-02-23

    The CERN accelerators deliver a wide spectrum of secondary beams to the Experimental Areas. These beams are composed of hadrons, leptons, and heavy ions that can vary greatly in momentum (1 GeV/c to 400 GeV/c) and intensity (10^2 to 10^8 particles per second). The profile, position, and intensity of these beams are measured utilising particle detectors. However, the current systems show several problems that limit the quality of this kind of monitoring. The aim of this doctoral thesis is to investigate the best detector technology that could replace the existing monitors and build a first prototype of it. A review of the existing detection techniques has led to the choice of Scintillating Fibres (SciFi) read-out with Silicon Photomultipliers (SiPM). This detection technology has the potential to perform better in terms of material budget, range of intensities measured, and active area size. In addition, it has particle counting capabilities, which could extend its application to momentum spectrometry or Time...

  16. Individual-Based Allometric Equations Accurately Measure Carbon Storage and Sequestration in Shrublands

    Directory of Open Access Journals (Sweden)

    Norman W.H. Mason

    2014-02-01

    Full Text Available Many studies have quantified uncertainty in forest carbon (C storage estimation, but there is little work examining the degree of uncertainty in shrubland C storage estimates. We used field data to simulate uncertainty in carbon storage estimates from three error sources: (1 allometric biomass equations; (2 measurement errors of shrubs harvested for the allometry; and (3 measurement errors of shrubs in survey plots. We also assessed uncertainty for all possible combinations of these error sources. Allometric uncertainty had the greatest independent effect on C storage estimates for individual plots. The largest error arose when all three error sources were included in simulations (where the 95% confidence interval spanned a range equivalent to 40% of mean C storage. Mean C sequestration (1.73 Mg C ha–1 year–1 exceeded the margin of error produced by the simulated sources of uncertainty. This demonstrates that, even when the major sources of uncertainty were accounted for, we were able to detect relatively modest gains in shrubland C storage.

  17. Compensation of the exhaust gas transport dynamics for accurate instantaneous emission measurements.

    Science.gov (United States)

    Ajtay, Delia; Weilenmann, Martin

    2004-10-01

    Instantaneous emission models of vehicles describe the amount of emitted pollutants as a function of the driving state of the car. Emission measurements of chassis dynamometer tests with high time resolution are necessary for the development of such models. However, the dynamics of gas transport in both the exhaust system of the car and the measurement line last significantly longer than 1 s. In a simplified approach, the transport dynamics can be divided into two parts: a perfect time delay, corresponding to a piston-like transport of the exhaust gas, and a dynamic part, corresponding to the mixing of gases by turbulence along the way. This determines the occurrence of emission peaks that are longer in time and lower in height at the analyzer than they actually are in the vehicle at their location of formation. It is shown here how the sharp emission signals at their location of formation can be reconstructed from the flattened emission signals recorded at the analyzer by using signal theory approaches. A comparison between the reconstructions quality when using the raw or the dilution analyzer system is also given.

  18. Is there an accurate method to measure metabolic requirement of institutionalized children with spastic cerebral palsy?

    Science.gov (United States)

    Lee, Siu Pik Peggy; Cheung, Ka Ming; Ko, Chun Hung; Chiu, Heung Chin

    2011-07-01

    This study hypothesized that there is no difference between energy expenditure measured by indirect calorimetry (IC) and that estimated by predicted formulas compared with the actual intake of children with spastic cerebral palsy (CP). Fifteen children aged 3 to 18 years with spastic CP and associated complications were recruited. IC was used to measure mean energy expenditure (MEE) compared with 3 predicted equations for energy expenditure (PEE), including body surface area (BSA), the recommended daily allowance (RDA), and an equation designed specifically for patients with CP. Friedman and paired t tests were used to examine the variance between PEE and MEE. Intraclass correlation coefficient (ICC) was used to explore the correlation between MEE and PEE. The pretest and posttest core temperatures were compared using the Wilcoxon signed rank test. Mean ± standard deviation MEE was 800.5 ± 295.7 kcal/d; BSA was 1,213.4 ± 171.2 kcal/d; RDA was 1,928.1 ± 341.0 kcal/d; and CP was 1,603.1 ± 215.8 kcal/d. The actual diet intake provided 935.3 ± 222.9 kcal/d. Post hoc analysis revealed a significant difference between mean MEE and PEE (P children with spastic CP.

  19. Quantitatively accurate activity measurements with a dedicated cardiac SPECT camera: Physical phantom experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pourmoghaddas, Amir, E-mail: apour@ottawaheart.ca; Wells, R. Glenn [Physics Department, Carleton University, Ottawa, Ontario K1S 5B6, Canada and Cardiology, The University of Ottawa Heart Institute, Ottawa, Ontario K1Y4W7 (Canada)

    2016-01-15

    Purpose: Recently, there has been increased interest in dedicated cardiac single photon emission computed tomography (SPECT) scanners with pinhole collimation and improved detector technology due to their improved count sensitivity and resolution over traditional parallel-hole cameras. With traditional cameras, energy-based approaches are often used in the clinic for scatter compensation because they are fast and easily implemented. Some of the cardiac cameras use cadmium-zinc-telluride (CZT) detectors which can complicate the use of energy-based scatter correction (SC) due to the low-energy tail—an increased number of unscattered photons detected with reduced energy. Modified energy-based scatter correction methods can be implemented, but their level of accuracy is unclear. In this study, the authors validated by physical phantom experiments the quantitative accuracy and reproducibility of easily implemented correction techniques applied to {sup 99m}Tc myocardial imaging with a CZT-detector-based gamma camera with multiple heads, each with a single-pinhole collimator. Methods: Activity in the cardiac compartment of an Anthropomorphic Torso phantom (Data Spectrum Corporation) was measured through 15 {sup 99m}Tc-SPECT acquisitions. The ratio of activity concentrations in organ compartments resembled a clinical {sup 99m}Tc-sestamibi scan and was kept consistent across all experiments (1.2:1 heart to liver and 1.5:1 heart to lung). Two background activity levels were considered: no activity (cold) and an activity concentration 1/10th of the heart (hot). A plastic “lesion” was placed inside of the septal wall of the myocardial insert to simulate the presence of a region without tracer uptake and contrast in this lesion was calculated for all images. The true net activity in each compartment was measured with a dose calibrator (CRC-25R, Capintec, Inc.). A 10 min SPECT image was acquired using a dedicated cardiac camera with CZT detectors (Discovery NM530c, GE

  20. Accurate optical measurement of nuclear polarization in optically pumped ^3He gas

    Science.gov (United States)

    Bigelow, N. P.; Nacher, P. J.; Leduc, M.

    1992-12-01

    Large nuclear polarizations M (over 80 %) can now be achieved in gaseous ^3He by optical pumping. The gas is excited by an RF discharge and is oriented using a high power LNA laser which is lamp pumped and tuned to the 2 ^3S-2 ^3P transition at 1.08 μm. In this paper we describe an experiment in which we measure M with high absolute precision. Our method is based on a change as a function of M in the ratio of σ or π polarized light absorbed from a weak probe beam by the 2 ^3S metastable atoms. The probe was delivered by a diode pumped LNA laser and propagated perpendicular to the direction of the magnetization. Simultaneous measurement of M was made by monitoring the degree of circular polarization \\cal{P} of the optical line at 668 nm emitted by the discharge. Our measurements show a linear relationship between M and \\cal{P} for all accessible M values and for a wide range of experimental conditions (sample pressure, magnetic field, RF discharge level, etc.). This provides a second method of measurement of the ^3He nuclear polarization which is simple to operate and is calibrated and is calibrated over a pressure range of 0.15 to 6.5 torr. On peut maintenant produire par pompage optique de fortes polarisations nucléaires M (M supérieure à 80 % dans l' ^3He gazeux. Le gaz est excité par une décharge radiofréquence et orienté à l'aide d'un laser LNA de forte intensité qui est pompé par des lampes et accordé sur la transition 2 ^3S-2 ^3P à 1,08 μm. Dans cet article, nous décrivons une expérience où nous mesurons M avec une grande précision absolue. Notre méthode est fondée sur la variation en fonction de M de l'absorption par les atomes métastables d'un faisceau sonde de faible intensité polarisé linéairement. Nous mesurons le rapport des absorptions pour des polarisations π et σ. Le faisceau sonde est un laser LNA pompé par diode qui se propage perpendiculairement à la direction de l'aimantation. Simultanément, nous mesurons M par le

  1. Material interactions with the Low Earth Orbital (LEO) environment: Accurate reaction rate measurements

    Science.gov (United States)

    Visentine, James T.; Leger, Lubert J.

    1987-01-01

    To resolve uncertainties in estimated LEO atomic oxygen fluence and provide reaction product composition data for comparison to data obtained in ground-based simulation laboratories, a flight experiment has been proposed for the space shuttle which utilizes an ion-neutral mass spectrometer to obtain in-situ ambient density measurements and identify reaction products from modeled polymers exposed to the atomic oxygen environment. An overview of this experiment is presented and the methodology of calibrating the flight mass spectrometer in a neutral beam facility prior to its use on the space shuttle is established. The experiment, designated EOIM-3 (Evaluation of Oxygen Interactions with Materials, third series), will provide a reliable materials interaction data base for future spacecraft design and will furnish insight into the basic chemical mechanisms leading to atomic oxygen interactions with surfaces.

  2. Accurate measurement of JHHin overlapped signals by a TOCSY-edited SERF Experiment.

    Science.gov (United States)

    Fredi, André; Nolis, Pau; Parella, Teodor

    2017-06-01

    Selective refocusing (GSERF or the recent PSYCHEDELIC) experiments were originally designed to determine all proton-proton coupling constants (J HH ) for a selected proton resonance. They work for isolated signals on which selective excitation can be successfully applied but, as it happens in other selective experiments, fail for overlapped signals. To circumvent this limitation, a doubly-selective TOCSY-GSERF scheme is presented for the measurement of J HH in protons resonating in crowded regions. This new experiment takes advantage of the editing features of an initial TOCSY transfer to uncover hidden resonances that become accessible to perform the subsequent frequency-selective refocusing. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Radiochromic Plastic Films for Accurate Measurement of Radiation Absorbed Dose and Dose Distributions

    DEFF Research Database (Denmark)

    McLaughlin, W. L.; Miller, Arne; Fidan, S.

    1977-01-01

    Thin radiochromic dye films are useful for measuring large radiation absorbed doses (105–108 rads) and for high-resolution imaging of dose patterns produced by penetrating radiation beams passing through non-homogeneous media. Certain types of amino-substituted triarylmethane cyanides dissolved...... in polymeric solutions can be cast into flexible free-standing thin films of uniform thickness and reproducible response to ultraviolet and ionizing radiation. The increase in optical density versus energy deposited by radiation is linear over a wide range of doses and is for practical purposes independent...... of dose rate (1–1014 rad s−1). Upon irradiation of the film, the profile of the radiation field is registered as a permanent colored image of the dose distribution. Unlike most other types of dyed plastic dose meters, the optical density produced by irradiation is in most cases stable for periods...

  4. How Accurately Can We Measure Galaxy Environment at High Redshift Using Only Photometric Redshifts?

    Science.gov (United States)

    Florez, Jonathan; Jogee, Shardha; Sherman, Sydney; Papovich, Casey J.; Finkelstein, Steven L.; Stevans, Matthew L.; Kawinwanichakij, Lalitwadee; Ciardullo, Robin; Gronwall, Caryl; SHELA/HETDEX

    2017-06-01

    We use a powerful synergy of six deep photometric surveys (Herschel SPIRE, Spitzer IRAC, NEWFIRM K-band, DECam ugriz, and XMM X-ray) and a future optical spectroscopic survey (HETDEX) in the Stripe 82 field to study galaxy evolution during the 1.9 environment using only our photometric redshifts. We compare both local and large-scale measures of environment (e.g., projected two-point correlation function, projected nearest neighbor densities, and galaxy counts within some projected aperture) at different photometric redshifts to cosmological simulations in order to quantify the uncertainty in our estimates of environment. We also explore how robustly one can recover the variation of galaxy properties with environment, when using only photometric redshifts. In the era of large photometric surveys, this work has broad implications for studies addressing the impact of environment on galaxy evolution at early cosmic epochs. We acknowledge support from NSF grants AST-1614798, AST-1413652 and NSF GRFP grant DGE-1610403.

  5. Accurate fault location algorithm on power transmission lines with use of two-end unsynchronized measurements

    Directory of Open Access Journals (Sweden)

    Mohamed Dine

    2012-01-01

    Full Text Available This paper presents a new approach to fault location on power transmission lines. This approach uses two-end unsynchronised measurements of the line and benefits from the advantages of digital technology and numerical relaying, which are available today and can easily be applied for off-line analysis. The approach is to modify the apparent impedance method using a very simple first-order formula. The new method is independent of fault resistance, source impedances and pre-fault currents. In addition, the data volume communicated between relays is sufficiently small enough to be transmitted easily using a digital protection channel. The proposed approach is tested via digital simulation using MATLand the applied test results corroborate the superior performance of the proposed approach.

  6. Defense Automated Neurobehavioral Assessment Accurately Measures Cognition in Patients Undergoing Electroconvulsive Therapy for Major Depressive Disorder.

    Science.gov (United States)

    Hollinger, Kristen R; Woods, Steven R; Adams-Clark, Alexis; Choi, So Yung; Franke, Caroline L; Susukida, Ryoko; Thompson, Carol; Reti, Irving M; Kaplin, Adam I

    2017-10-03

    The Defense Automated Neurobehavioral Assessment (DANA) is an electronic cognitive test battery. The present study compares DANA to the standard Mini-Mental State Examination (MMSE) in subjects undergoing electroconvulsive therapy for the treatment of major depressive disorder. Seventeen inpatient subjects in the Johns Hopkins Hospital Department of Psychiatry were administered longitudinal paired DANA and MMSE tests (7.6 ± 4.1 per patient) from January 10, 2014 to September 26, 2014. Regression analyses were conducted (with or without MMSE scores of 30) to study the impact of the MMSE upper limit, and within-subject regression analyses were conducted to compare MMSE and DANA scores over time. Statistically significant relationships were measured between DANA and MMSE scores. Relationships strengthened when MMSE scores of 30 were omitted from analyses, demonstrating a ceiling effect of the MMSE. Within-subject analyses revealed relationships between MMSE and DANA scores over the duration of the inpatient stay. Defense Automated Neurobehavioral Assessment is an electronic, mobile, repeatable, sensitive, and valid method of measuring cognition over time in depressed patients undergoing electroconvulsive therapy treatment. Automation of the DANA allows for more frequent cognitive testing in a busy clinical setting and enhances cognitive assessment sensitivity with a timed component to each test.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

  7. Accurately measuring the quality and effectiveness of lumbar surgery in registry efforts: determining the most valid and responsive instruments.

    Science.gov (United States)

    Godil, Saniya S; Parker, Scott L; Zuckerman, Scott L; Mendenhall, Stephen K; Glassman, Steven D; McGirt, Matthew J

    2014-12-01

    Prospective registries have emerged as a feasible way to capture real-world care across large patient populations. However, the proven validity of more robust and cumbersome patient-reported outcomes instruments (PROis) must be balanced with what is feasible to apply in large-scale registry efforts. To determine the relative validity and responsiveness of common PROis in accurately determining effectiveness of lumbar fusion for degenerative lumbar spondylolisthesis in registry efforts. Prospective cohort study. Fifty-eight patients undergoing transforaminal lumbar interbody fusion (TLIF) for degenerative lumbar spondylolisthesis Patient-reported outcome measures for pain (numeric rating scale for back and leg pain [NRS-BP, NRS-LP]), disability (Oswestry Disability Index [ODI]), general health (Short Form [SF]-12), quality of life (QOL) (EuroQol five dimensions [EQ-5D]), and depression (Zung depression scale [ZDS]) were assessed. Fifty-eight patients undergoing primary TLIF for lumbar spondylolisthesis were entered into an institutional registry and prospectively followed for 2 years. Baseline and 2-year patient-reported outcomes were assessed. To assess the validity of PROis to discriminate between effective and noneffective improvements, receiver operating characteristic curves were generated for each outcomes instrument. An area under the curve (AUC) of ≥0.80 was considered an accurate discriminator. The difference between standardized response means (SRMs) in patients reporting meaningful improvement versus not was calculated to determine the relative responsiveness of each instrument. For pain and disability, ODI had AUC=0.94, suggesting it as an accurate discriminator of meaningful improvement. Oswestry Disability Index was most responsive to postoperative improvement (SRM difference: 2.18), followed by NRS-BP and NRS-LP. For general health and QOL, SF-12 physical component score (AUC: 0.90), ZDS (AUC: 0.89), and SF-12 mental component score (AUC: 0.85) were

  8. Standardization of vitrinite reflectance measurements in shale petroleum systems: How accurate are my Ro data?

    Science.gov (United States)

    Hackley, Paul C.

    2014-01-01

    Vitrinite reflectance generally is considered the most robust thermal maturity parameter available for application to hydrocarbon exploration and petroleum system evaluation. However, until 2011 there was no standardized methodology available to provide guidelines for vitrinite reflectance measurements in shale. Efforts to correct this deficiency resulted in publication of ASTM D7708-11: Standard test method for microscopical determination of the reflectance of vitrinite dispersed in sedimentary rocks. In 2012-2013, an interlaboratory exercise was conducted to establish precision limits for the measurement technique. Six samples, representing a wide variety of shale, were tested in duplicate by 28 analysts in 22 laboratories from 14 countries. Samples ranged from immature to overmature (Ro 0.31-1.53%), from organic-rich to organic-lean (1-22 wt.% total organic carbon), and contained Type I (lacustrine), Type II (marine), and Type III (terrestrial) kerogens. Repeatability values (difference between repetitive results from same operator, same conditions) ranged from 0.03-0.11% absolute reflectance, whereas reproducibility values (difference between results obtained on same test material by different operators, different laboratories) ranged from 0.12-0.54% absolute reflectance. Repeatability and reproducibility degraded consistently with increasing maturity and decreasing organic content. However, samples with terrestrial kerogens (Type III) fell off this trend, showing improved levels of reproducibility due to higher vitrinite content and improved ease of identification. Operators did not consistently meet the reporting requirements of the test method, indicating that a common reporting template is required to improve data quality. The most difficult problem encountered was the petrographic distinction of solid bitumens and low-reflecting inert macerals from vitrinite when vitrinite occurred with reflectance ranges overlapping the other components. Discussion among

  9. Accurate measurement of a fission chamber efficiency using the prompt fission neutron method

    Directory of Open Access Journals (Sweden)

    Mathieu Ludovic

    2017-01-01

    Full Text Available Fission Chambers (FC are often used to determine fission cross sections and to measure the neutron beam flux via standard neutron-induced fission reactions. Thus, the fission detection efficiency is a key parameter. Several methods exist to determine this efficiency, with a final accuracy not better than 1%. The detection of prompt fission neutrons allows events related to the fission process to be tagged, and enables the efficiency to be inferred with accuracy of the order of few 0.1%. This method is very robust since it is independent in first order to several factors like geometry, used materials or neutron contour selection. To obtain high accuracy, few corrections have still to be taken into account. In particular, the neutron detectors have to cover several detection angles. In addition, the background contribution of neutrons from cosmic rays or from an accelerator has to be removed. Several experiments based on the use of a 252Cf source are presented to describe all these points.

  10. Identifying clinical measures that most accurately reflect the progression of disability in Parkinson disease.

    Science.gov (United States)

    Ellis, Terry D; Cavanaugh, James T; Earhart, Gammon M; Ford, Matthew P; Foreman, K Bo; Thackeray, Anne; Thiese, Matthew S; Dibble, Leland E

    2016-04-01

    The temporal relationship between disease and disability progression in Parkinson disease (PD) is not well understood. Our objective was to describe the natural, multidimensional trajectory of disability in persons with PD over a two-year period. We conducted a multi-center, prospective cohort study involving four institutions. Data were collected at baseline and at 6-month intervals over 2 years using standardized clinical tests representing three World Health Organization defined disability domains: impairment, activity limitation, and participation restriction. Unadjusted mixed effects growth models characterized trajectories of disability in the three disability domains. The data set was analyzed using restricted maximum likelihood (REML) estimation. Standardized estimates of change were also computed using Cohen's d for each measure. Of the 266 enrolled participants, we analysed data from individuals who participated in at least 3 assessments (n = 207, 79%). Rates of disability progression over the 2-year period differed across domains. Moderate effects were detected for motor impairment (d = .28) and walking-related activity limitation (gait-related balance (d = .31); gait speed (d = .30)). Marginal effects were noted for upper extremity-related activity limitation (d = .11) and health-related quality of life participation restriction (d = .08). The natural trajectory of walking-related activity limitation was the most potent indicator of evolving disability, suggesting that routine assessment of walking and periodic rehabilitation is likely to be warranted for many persons with PD. Natural trajectories of disability provide important comparison data for future intervention studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Accurate Measurements of Free Flight Drag Coefficients with Amateur Doppler Radar

    CERN Document Server

    Courtney, Elya; Courtney, Michael

    2016-01-01

    In earlier papers, techniques have been described using optical chronographs to determine free flight drag coefficients with an accuracy of 1-2%, accomplished by measuring near and far velocities of projectiles in flight over a known distance. Until recently, Doppler radar has been prohibitively expensive for many users. This paper reports results of exploring potential applications and accuracy using a recently available, inexpensive (< $600 US) amateur Doppler radar system to determine drag coefficients for projectiles of various sizes (4.4 mm to 9 mm diameter) and speeds (M0.3 to M3.0). In many cases, drag coefficients can be determined with an accuracy of 1% or better if signal-to-noise ratio is sufficient and projectiles vary little between trials. It is also straightforward to design experiments for determining drag over a wide range of velocities. Experimental approaches and limitations are described. Overall, the amateur radar system shows greater accuracy, ease of use, and simplicity compared with...

  12. S3 HMBC hetero: Spin-State-Selective HMBC for accurate measurement of long-range heteronuclear coupling constants

    Science.gov (United States)

    Hoeck, Casper; Gotfredsen, Charlotte H.; Sørensen, Ole W.

    2017-02-01

    A novel method, Spin-State-Selective (S3) HMBC hetero, for accurate measurement of heteronuclear coupling constants is introduced. The method extends the S3 HMBC technique for measurement of homonuclear coupling constants by appending a pulse sequence element that interchanges the polarization in 13C-1H methine pairs. This amounts to converting the spin-state selectivity from 1H spin states to 13C spin states in the spectra of long-range coupled 1H spins, allowing convenient measurement of heteronuclear coupling constants similar to other S3 or E.COSY-type methods. As usual in this type of techniques, the accuracy of coupling constant measurement is independent of the size of the coupling constant of interest. The merits of the new method are demonstrated by application to vinyl acetate, the alkaloid strychnine, and the carbohydrate methyl β-maltoside.

  13. The need for preoperative baseline arm measurement to accurately quantify breast cancer-related lymphedema.

    Science.gov (United States)

    Sun, Fangdi; Skolny, Melissa N; Swaroop, Meyha N; Rawal, Bhupendra; Catalano, Paul J; Brunelle, Cheryl L; Miller, Cynthia L; Taghian, Alphonse G

    2016-06-01

    Breast cancer-related lymphedema (BCRL) is a feared outcome of breast cancer treatment, yet the push for early screening is hampered by a lack of standardized quantification. We sought to determine the necessity of preoperative baseline in accounting for temporal changes of upper extremity volume. 1028 women with unilateral breast cancer were prospectively screened for lymphedema by perometry. Thresholds were defined: relative volume change (RVC) ≥10 % for clinically significant lymphedema and ≥5 % including subclinical lymphedema. The first postoperative measurement (pseudo-baseline) simulated the case of no baseline. McNemar's test and binomial logistic regression models were used to analyze BCRL misdiagnoses. Preoperatively, 28.3 and 2.9 % of patients had arm asymmetry of ≥5 and 10 %, respectively. Without baseline, 41.6 % of patients were underdiagnosed and 40.1 % overdiagnosed at RVC ≥ 5 %, increasing to 50.0 and 54.8 % at RVC ≥ 10 %. Increased pseudo-baseline asymmetry, increased weight change between baselines, hormonal therapy, dominant use of contralateral arm, and not receiving axillary lymph node dissection (ALND) were associated with increased risk of underdiagnosis at RVC ≥ 5 %; not receiving regional lymph node radiation was significant at RVC ≥ 10 %. Increased pseudo-baseline asymmetry, not receiving ALND, and dominant use of ipsilateral arm were associated with overdiagnosis at RVC ≥ 5 %; increased pseudo-baseline asymmetry and not receiving ALND were significant at RVC ≥ 10 %. The use of a postoperative proxy even early after treatment results in poor sensitivity for identifying BCRL. Providers with access to patients before surgery should consider the consequent need for proper baseline, with specific strategy tailored by institution.

  14. Novel methodology for accurate resolution of fluid signatures from multi-dimensional NMR well-logging measurements.

    Science.gov (United States)

    Anand, Vivek

    2017-03-01

    A novel methodology for accurate fluid characterization from multi-dimensional nuclear magnetic resonance (NMR) well-logging measurements is introduced. This methodology overcomes a fundamental challenge of poor resolution of features in multi-dimensional NMR distributions due to low signal-to-noise ratio (SNR) of well-logging measurements. Based on an unsupervised machine-learning concept of blind source separation, the methodology resolves fluid responses from simultaneous analysis of large quantities of well-logging data. The multi-dimensional NMR distributions from a well log are arranged in a database matrix that is expressed as the product of two non-negative matrices. The first matrix contains the unique fluid signatures, and the second matrix contains the relative contributions of the signatures for each measurement sample. No a priori information or subjective assumptions about the underlying features in the data are required. Furthermore, the dimensionality of the data is reduced by several orders of magnitude, which greatly simplifies the visualization and interpretation of the fluid signatures. Compared to traditional methods of NMR fluid characterization which only use the information content of a single measurement, the new methodology uses the orders-of-magnitude higher information content of the entire well log. Simulations show that the methodology can resolve accurate fluid responses in challenging SNR conditions. The application of the methodology to well-logging data from a heavy oil reservoir shows that individual fluid signatures of heavy oil, water associated with clays and water in interstitial pores can be accurately obtained. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Ion recombination correction factor in scanned light-ion beams for absolute dose measurement using plane-parallel ionisation chambers.

    Science.gov (United States)

    Rossomme, S; Horn, J; Brons, S; Jäkel, O; Mairani, A; Ciocca, M; Floquet, V; Romano, F; Rodriguez Garcia, D; Vynckier, S; Palmans, H

    2017-07-07

    Based on international reference dosimetry protocols for light-ion beams, a correction factor (k s) has to be applied to the response of a plane-parallel ionisation chamber, to account for recombination of negative and positive charges in its air cavity before these charges can be collected on the electrodes. In this work, k s for IBA PPC40 Roos-type chambers is investigated in four scanned light-ion beams (proton, helium, carbon and oxygen). To take into account the high dose-rates used with scanned beams and LET-values, experimental results are compared to a model combining two theories. One theory, developed by Jaffé, describes the variation of k s with the ionization density within the ion track (initial recombination) and the other theory, developed by Boag, describes the variation of k s with the dose rate (volume recombination). Excellent agreement is found between experimental and theoretical k s-values. All results confirm that k s cannot be neglected. The solution to minimise k s is to use the ionisation chamber at high voltage. However, one must be aware that charge multiplication may complicate the interpretation of the measurement. For the chamber tested, it was found that a voltage of 300 V can be used without further complication. As the initial recombination has a logarithmic variation as a function of 1/V, the two-voltage method is not applicable to these scanned beams.

  16. On the c-Si/SiO2 interface recombination parameters from photo-conductance decay measurements

    Science.gov (United States)

    Bonilla, Ruy S.; Wilshaw, Peter R.

    2017-04-01

    The recombination of electric charge carriers at semiconductor surfaces continues to be a limiting factor in achieving high performance optoelectronic devices, including solar cells, laser diodes, and photodetectors. The theoretical model and a solution algorithm for surface recombination have been previously reported. However, their successful application to experimental data for a wide range of both minority excess carrier concentrations and dielectric fixed charge densities has not previously been shown. Here, a parametrisation for the semiconductor-dielectric interface charge Q i t is used in a Shockley-Read-Hall extended formalism to describe recombination at the c-Si/SiO2 interface, and estimate the physical parameters relating to the interface trap density D i t , and the electron and hole capture cross-sections σ n and σ p . This approach gives an excellent description of the experimental data without the need to invoke a surface damage region in the c-Si/SiO2 system. Band-gap tail states have been observed to limit strongly the effectiveness of field effect passivation. This approach provides a methodology to determine interface recombination parameters in any semiconductor-insulator system using macro scale measuring techniques.

  17. Accurate isotopic fission yields of electromagnetically induced fission of 238U measured in inverse kinematics at relativistic energies

    Science.gov (United States)

    Pellereau, E.; Taïeb, J.; Chatillon, A.; Alvarez-Pol, H.; Audouin, L.; Ayyad, Y.; Bélier, G.; Benlliure, J.; Boutoux, G.; Caamaño, M.; Casarejos, E.; Cortina-Gil, D.; Ebran, A.; Farget, F.; Fernández-Domínguez, B.; Gorbinet, T.; Grente, L.; Heinz, A.; Johansson, H.; Jurado, B.; Kelić-Heil, A.; Kurz, N.; Laurent, B.; Martin, J.-F.; Nociforo, C.; Paradela, C.; Pietri, S.; Rodríguez-Sánchez, J. L.; Schmidt, K.-H.; Simon, H.; Tassan-Got, L.; Vargas, J.; Voss, B.; Weick, H.

    2017-05-01

    SOFIA (Studies On Fission with Aladin) is a novel experimental program, dedicated to accurate measurements of fission-fragment isotopic yields. The setup allows us to fully identify, in nuclear charge and mass, both fission fragments in coincidence for the whole fission-fragment range. It was installed at the GSI facility (Darmstadt), to benefit from the relativistic heavy-ion beams available there, and thus to use inverse kinematics. This paper reports on fission yields obtained in electromagnetically induced fission of 238U.

  18. Non-destructive testing principles and accurate evaluation of the hydraulic measure impact range using the DC method

    Science.gov (United States)

    Qiu, Liming; Shen, Rongxi; Song, Dazhao; Wang, Enyuan; Liu, Zhentang; Niu, Yue; Jia, Haishan; Xia, Shankui; Zheng, Xiangxin

    2017-12-01

    An accurate and non-destructive evaluation method for the hydraulic measure impact range in coal seams is urgently needed. Aiming at the application demands, a theoretical study and field test are presented using the direct current (DC) method to evaluate the impact range of coal seam hydraulic measures. We firstly analyzed the law of the apparent resistivity response of an abnormal conductive zone in a coal seam, and then investigated the principle of non-destructive testing of the coal seam hydraulic measure impact range using the DC method, and used an accurate evaluation method based on the apparent resistivity cloud chart. Finally, taking hydraulic fracturing and hydraulic flushing as examples, field experiments were carried out in coal mines to evaluate the impact ranges. The results showed that: (1) in the process of hydraulic fracturing, coal conductivity was enhanced by high-pressure water in the coal seam, and after hydraulic fracturing, the boundary of the apparent resistivity decrease area was the boundary impact range. (2) In the process of hydraulic flushing, coal conductivity was reduced by holes and cracks in the coal seam, and after hydraulic flushing, the boundary of the apparent resistivity increase area was the boundary impact range. (3) After the implementation of the hydraulic measures, there may be some blind zones in the coal seam; in hydraulic fracturing blind zones, the apparent resistivity increased or stayed constant, while in hydraulic flushing blind zones, the apparent resistivity decreased or stayed constant. The DC method realized a comprehensive and non-destructive evaluation of the impact range of the hydraulic measures, and greatly reduced the time and cost of evaluation.

  19. An accurate Rb density measurement method for a plasma wakefield accelerator experiment using a novel Rb reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Öz, E.; Batsch, F.; Muggli, P.

    2016-09-01

    A method to accurately measure the density of Rb vapor is described. We plan on using this method for the Advanced Wakefield (AWAKE) (Assmann et al., 2014 [1]) project at CERN , which will be the world's first proton driven plasma wakefield experiment. The method is similar to the hook (Marlow, 1967 [2]) method and has been described in great detail in the work by Hill et al. (1986) [3]. In this method a cosine fit is applied to the interferogram to obtain a relative accuracy on the order of 1% for the vapor density–length product. A single-mode, fiber-based, Mach–Zenhder interferometer will be built and used near the ends of the 10 meter-long AWAKE plasma source to be able to make accurate relative density measurement between these two locations. This can then be used to infer the vapor density gradient along the AWAKE plasma source and also change it to the value desired for the plasma wakefield experiment. Here we describe the plan in detail and show preliminary results obtained using a prototype 8 cm long novel Rb vapor cell.

  20. Measuring Physical Inactivity: Do Current Measures Provide an Accurate View of “Sedentary” Video Game Time?

    Directory of Open Access Journals (Sweden)

    Simon Fullerton

    2014-01-01

    Full Text Available Background. Measures of screen time are often used to assess sedentary behaviour. Participation in activity-based video games (exergames can contribute to estimates of screen time, as current practices of measuring it do not consider the growing evidence that playing exergames can provide light to moderate levels of physical activity. This study aimed to determine what proportion of time spent playing video games was actually spent playing exergames. Methods. Data were collected via a cross-sectional telephone survey in South Australia. Participants aged 18 years and above (n=2026 were asked about their video game habits, as well as demographic and socioeconomic factors. In cases where children were in the household, the video game habits of a randomly selected child were also questioned. Results. Overall, 31.3% of adults and 79.9% of children spend at least some time playing video games. Of these, 24.1% of adults and 42.1% of children play exergames, with these types of games accounting for a third of all time that adults spend playing video games and nearly 20% of children’s video game time. Conclusions. A substantial proportion of time that would usually be classified as “sedentary” may actually be spent participating in light to moderate physical activity.

  1. Can endocranial volume be estimated accurately from external skull measurements in great-tailed grackles (Quiscalus mexicanus)?

    Science.gov (United States)

    Logan, Corina J; Palmstrom, Christin R

    2015-01-01

    There is an increasing need to validate and collect data approximating brain size on individuals in the field to understand what evolutionary factors drive brain size variation within and across species. We investigated whether we could accurately estimate endocranial volume (a proxy for brain size), as measured by computerized tomography (CT) scans, using external skull measurements and/or by filling skulls with beads and pouring them out into a graduated cylinder for male and female great-tailed grackles. We found that while females had higher correlations than males, estimations of endocranial volume from external skull measurements or beads did not tightly correlate with CT volumes. We found no accuracy in the ability of external skull measures to predict CT volumes because the prediction intervals for most data points overlapped extensively. We conclude that we are unable to detect individual differences in endocranial volume using external skull measurements. These results emphasize the importance of validating and explicitly quantifying the predictive accuracy of brain size proxies for each species and each sex.

  2. Can endocranial volume be estimated accurately from external skull measurements in great-tailed grackles (Quiscalus mexicanus?

    Directory of Open Access Journals (Sweden)

    Corina J. Logan

    2015-06-01

    Full Text Available There is an increasing need to validate and collect data approximating brain size on individuals in the field to understand what evolutionary factors drive brain size variation within and across species. We investigated whether we could accurately estimate endocranial volume (a proxy for brain size, as measured by computerized tomography (CT scans, using external skull measurements and/or by filling skulls with beads and pouring them out into a graduated cylinder for male and female great-tailed grackles. We found that while females had higher correlations than males, estimations of endocranial volume from external skull measurements or beads did not tightly correlate with CT volumes. We found no accuracy in the ability of external skull measures to predict CT volumes because the prediction intervals for most data points overlapped extensively. We conclude that we are unable to detect individual differences in endocranial volume using external skull measurements. These results emphasize the importance of validating and explicitly quantifying the predictive accuracy of brain size proxies for each species and each sex.

  3. Ultrasonic Measurement of Change in Elasticity due to Endothelium Dependent Relaxation Response by Accurate Detection of Artery-Wall Boundary

    Science.gov (United States)

    Kaneko, Takuya; Hasegawa, Hideyuki; Kanai, Hiroshi

    2007-07-01

    Ross hypothesized that an endothelial dysfunction is considered to be an initial step in atherosclerosis. Endothelial cells, which release nitric oxide (NO) in response to shear stress from blood flow, have a function of relaxing smooth muscle in the media of the arterial wall. For the assessment of the endothelial function, there is a conventional method in which the change in the diameter of the brachial artery caused by flow-mediated dilation (FMD) is measured with ultrasound. However, despite the fact that the collagen-rich hard adventitia does not respond to NO, the conventional method measures the change in diameter depending on the mechanical property of the entire wall including the adventitia. Therefore, we developed a method of measuring the change in the thickness and the elasticity of the brachial artery during a cardiac cycle using the phased tracking method for the evaluation of the mechanical property of only the intima-media region. In this study, the initial positions of echoes from the lumen-intima and media-adventitia boundaries are determined using complex template matching to accurately estimate the minute change in the thickness and the elasticity of the brachial and radial arteries. The ambiguity in the determination of such boundaries was eliminated using complex template matching, and the change in elasticity measured by the proposed method was larger than the change in inner diameter obtained by the conventional method.

  4. The importance of accurate measurement of aortic stiffness in patients with chronic kidney disease and end-stage renal disease.

    Science.gov (United States)

    Adenwalla, Sherna F; Graham-Brown, Matthew P M; Leone, Francesca M T; Burton, James O; McCann, Gerry P

    2017-08-01

    Cardiovascular (CV) disease is the leading cause of death in chronic kidney disease (CKD) and end-stage renal disease (ESRD). A key driver in this pathology is increased aortic stiffness, which is a strong, independent predictor of CV mortality in this population. Aortic stiffening is a potentially modifiable biomarker of CV dysfunction and in risk stratification for patients with CKD and ESRD. Previous work has suggested that therapeutic modification of aortic stiffness may ameliorate CV mortality. Nevertheless, future clinical implementation relies on the ability to accurately and reliably quantify stiffness in renal disease. Pulse wave velocity (PWV) is an indirect measure of stiffness and is the accepted standard for non-invasive assessment of aortic stiffness. It has typically been measured using techniques such as applanation tonometry, which is easy to use but hindered by issues such as the inability to visualize the aorta. Advances in cardiac magnetic resonance imaging now allow direct measurement of stiffness, using aortic distensibility, in addition to PWV. These techniques allow measurement of aortic stiffness locally and are obtainable as part of a comprehensive, multiparametric CV assessment. The evidence cannot yet provide a definitive answer regarding which technique or parameter can be considered superior. This review discusses the advantages and limitations of non-invasive methods that have been used to assess aortic stiffness, the key studies that have assessed aortic stiffness in patients with renal disease and why these tools should be standardized for use in clinical trial work.

  5. Accurate measurements of carbon monoxide in humid air using the cavity ring-down spectroscopy (CRDS technique

    Directory of Open Access Journals (Sweden)

    H. Chen

    2013-04-01

    Full Text Available Accurate measurements of carbon monoxide (CO in humid air have been made using the cavity ring-down spectroscopy (CRDS technique. The measurements of CO mole fractions are determined from the strength of its spectral absorption in the near-infrared region (~1.57 μm after removing interferences from adjacent carbon dioxide (CO2 and water vapor (H2O absorption lines. Water correction functions that account for the dilution and pressure-broadening effects as well as absorption line interferences from adjacent CO2 and H2O lines have been derived for CO2 mole fractions between 360–390 ppm and for reported H2O mole fractions between 0–4%. The line interference corrections are independent of CO mole fractions. The dependence of the line interference correction on CO2 abundance is estimated to be approximately −0.3 ppb/100 ppm CO2 for dry mole fractions of CO. Comparisons of water correction functions from different analyzers of the same type show significant differences, making it necessary to perform instrument-specific water tests for each individual analyzer. The CRDS analyzer was flown on an aircraft in Alaska from April to November in 2011, and the accuracy of the CO measurements by the CRDS analyzer has been validated against discrete NOAA/ESRL flask sample measurements made on board the same aircraft, with a mean difference between integrated in situ and flask measurements of −0.6 ppb and a standard deviation of 2.8 ppb. Preliminary testing of CRDS instrumentation that employs improved spectroscopic model functions for CO2, H2O, and CO to fit the raw spectral data (available since the beginning of 2012 indicates a smaller water vapor dependence than the models discussed here, but more work is necessary to fully validate the performance. The CRDS technique provides an accurate and low-maintenance method of monitoring the atmospheric dry mole fractions of CO in humid air streams.

  6. Laser diode absorption spectroscopy for accurate CO(2) line parameters at 2 microm: consequences for space-based DIAL measurements and potential biases.

    Science.gov (United States)

    Joly, Lilian; Marnas, Fabien; Gibert, Fabien; Bruneau, Didier; Grouiez, Bruno; Flamant, Pierre H; Durry, Georges; Dumelie, Nicolas; Parvitte, Bertrand; Zéninari, Virginie

    2009-10-10

    Space-based active sensing of CO(2) concentration is a very promising technique for the derivation of CO(2) surface fluxes. There is a need for accurate spectroscopic parameters to enable accurate space-based measurements to address global climatic issues. New spectroscopic measurements using laser diode absorption spectroscopy are presented for the preselected R30 CO(2) absorption line ((20(0)1)(III)space-based DIAL CO(2) mixing ratio measurements associated to spectroscopic parameter uncertainties are presented.

  7. The gated integration technique for the accurate measurement of the autocorrelation function of speckle intensities scattered from random phase screens

    Science.gov (United States)

    Zhang, Ningyu; Cheng, Chuanfu; Teng, Shuyun; Chen, Xiaoyi; Xu, Zhizhan

    2007-09-01

    A new approach based on the gated integration technique is proposed for the accurate measurement of the autocorrelation function of speckle intensities scattered from a random phase screen. The Boxcar used for this technique in the acquisition of the speckle intensity data integrates the photoelectric signal during its sampling gate open, and it repeats the sampling by a preset number, m. The average analog of the m samplings output by the Boxcar enhances the signal-to-noise ratio by √{m}, because the repeated sampling and the average make the useful speckle signals stable, while the randomly varied photoelectric noise is suppressed by 1/√{m}. In the experiment, we use an analog-to-digital converter module to synchronize all the actions such as the stepped movement of the phase screen, the repeated sampling, the readout of the averaged output of the Boxcar, etc. The experimental results show that speckle signals are better recovered from contaminated signals, and the autocorrelation function with the secondary maximum is obtained, indicating that the accuracy of the measurement of the autocorrelation function is greatly improved by the gated integration technique.

  8. ON-LINE SELF-CALIBRATING SINGLE CRYSTAL SAPPHIRE OPTICAL SENSOR INSTRUMENTATION FOR ACCURATE AND RELIABLE COAL GASIFIER TEMPERATURE MEASUREMENT

    Energy Technology Data Exchange (ETDEWEB)

    Kristie Cooper; Gary Pickrell; Anbo Wang; Zhengyu Huang; Yizheng Zhu

    2005-04-01

    This report summarizes technical progress October 2004-March 2005 on the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the BPDI sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Due to the difficulties described on the last report, field testing of the BPDI system has not continued to date. However, we have developed an alternative high temperature sensing solution, which is described in this report.

  9. Accurate delineation of the grounding line from kinematic GPS measurements. Application to an outlet glacier in East Antarctica

    Science.gov (United States)

    Le Meur, E.; Sacchettini, M.; Durand, G.; Drouet, A.; Rignot, E. J.; Mouginot, J.; Young, D. A.; Blankenship, D.; Greenbaum, J.

    2011-12-01

    Polar ice sheets have a huge potential in terms of sea level rise. Recent measurements show clear evidence of a generalized speeding up of outlet glaciers in Greenland and West Antarctica and the question whether similar behaviors are to be expected in East Antarctica is all the more crucial as this latter represents the largest ice reservoir. Moreover, many glaciers in the Wilkes-Terre Adélie sector are in a supposedly unstable configuration due to a landward downsloping bedrock. As a consequence, the Astrolabe Glacier (Terre Adélie land) was selected as a test zone for extensive field surveys like surface and bedrock heights, surface velocities, mass balance measurements. Among those, the exact position of the grounding line is fundamental as it represents a strong transition in the flow regime when the basal drag of the grounded ice reduces to virtually zero when this latter starts to float over the ocean. We here propose a method based on GPS measurements along various profiles in order to identify the presence or not of tidal movements of the ice surface indicating floating ice. The amplitude of the tides of the order of a meter requires accurate data only possible with the differential GPS method. Processing of these GPS data along selected profiles allows us to propose a position for the grounding line (hydrostatic one) which we then compare to that obtained from remote techniques (Landsat-7, ICESat, differential satellite synthetic-aperture radar interferometry). The exact position of the grounding line as well as the exact surface height along a radar transect across the glacier (giving the underlying bedrock topography) is also used to infer a mean density for the whole ice column by applying the hydrostatic criterion and a firn depth correction.

  10. Combining Graphical and Analytical Methods with Molecular Simulations To Analyze Time-Resolved FRET Measurements of Labeled Macromolecules Accurately.

    Science.gov (United States)

    Peulen, Thomas-Otavio; Opanasyuk, Oleg; Seidel, Claus A M

    2017-09-07

    Förster resonance energy transfer (FRET) measurements from a donor, D, to an acceptor, A, fluorophore are frequently used in vitro and in live cells to reveal information on the structure and dynamics of DA labeled macromolecules. Accurate descriptions of FRET measurements by molecular models are complicated because the fluorophores are usually coupled to the macromolecule via flexible long linkers allowing for diffusional exchange between multiple states with different fluorescence properties caused by distinct environmental quenching, dye mobilities, and variable DA distances. It is often assumed for the analysis of fluorescence intensity decays that DA distances and D quenching are uncorrelated (homogeneous quenching by FRET) and that the exchange between distinct fluorophore states is slow (quasistatic). This allows us to introduce the FRET-induced donor decay, εD(t), a function solely depending on the species fraction distribution of the rate constants of energy transfer by FRET, for a convenient joint analysis of fluorescence decays of FRET and reference samples by integrated graphical and analytical procedures. Additionally, we developed a simulation toolkit to model dye diffusion, fluorescence quenching by the protein surface, and FRET. A benchmark study with simulated fluorescence decays of 500 protein structures demonstrates that the quasistatic homogeneous model works very well and recovers for single conformations the average DA distances with an accuracy of FRET-based dynamic structural biology. Finally, we present theories and simulations to assess the accuracy and precision of steady-state and time-resolved FRET measurements in resolving DA distances on the single-molecule and ensemble level and provide a rigorous framework for estimating approximation, systematic, and statistical errors.

  11. An accurate measurement of the baryonic Tully-Fisher relation with heavily gas-dominated ALFALFA galaxies

    Science.gov (United States)

    Papastergis, E.; Adams, E. A. K.; van der Hulst, J. M.

    2016-09-01

    We use a sample of 97 galaxies selected from the Arecibo legacy fast ALFA (ALFALFA) 21 cm survey to make an accurate measurement of the baryonic Tully-Fisher relation (BTFR). These galaxies are specifically selected to be heavily gas-dominated (Mgas/M∗ ≳ 2.7) and to be oriented edge-on. The former property ensures that the error on the galactic baryonic mass is small, despite the large systematic uncertainty involved in galactic stellar mass estimates. The latter property means that rotational velocities can be derived directly from the width of the 21 cm emission line, without any need for inclination corrections. We measure a slope for the linewidth-based BTFR of α = 3.75 ± 0.11, a value that is somewhat steeper than (but in broad agreement with) previous literature results. The relation is remarkably tight, with almost all galaxies being located within a perpendicular distance of ± 0.1 dex from the best fit line. The low observational error budget for our sample enables us to establish that, despite its tightness, the measured linewidth-based BTFR has some small (I.e., non-zero) intrinsic scatter. We furthermore find a systematic difference in the BTFR of galaxies with "double-horned" 21 cm line profiles - suggestive of flat outer galactic rotation curves - and those with "peaked" profiles - suggestive of rising rotation curves. When we restrict our sample of galaxies to objects in the former category, we measure a slightly steeper slope of α = 4.13 ± 0.15. Overall, the high-accuracy measurement of the BTFR presented in this article is intended as a reliable observational benchmark against which to test theoretical expectations. Here we consider a representative set of semi-analytic models and hydrodynamic simulations in the lambda cold dark matter (ΛCDM) context, as well as modified Newtonian dynamics (MOND). In the near future, interferometric follow-up observations of several sample members will enable us to further refine the BTFR measurement, and

  12. Estrogenic and mutagenic activities of Crotalaria pallida measured by recombinant yeast assay and Ames test.

    Science.gov (United States)

    Boldrin, Paula; Resende, Flávia; Höhne, Ana; de Camargo, Mariana; Espanha, Lívia; Nogueira, Catarine; Melo, Maria; Vilegas, Wagner; Varanda, Eliana

    2013-09-04

    Crotalaria pallida Ailton is a plant belonging to the Fabaceae family, popularly known as "rattle or rattlesnake" and used in traditional medicine to treat swelling of the joints and as a vermifuge. Previous pharmacological studies have also reported anti-inflammatory, antimicrobial and antifungal activities. Nevertheless, scientific information regarding this species is scarce, and there are no reports related to its possible estrogenic and mutagenic effects. Thus, the purpose of the present study was to investigate the estrogenic potential of C. pallida leaves by means of the Recombinant Yeast Assay (RYA), seeking an alternative for estrogen replacement therapy during menopause; and to reflect on the safe use of natural products to assess the mutagenic activity of the crude extract from C. pallida leaves, the dichloromethane fraction and stigmasterol by means of the Ames test. The recombinant yeast assay with the strain BY4741 of Saccharomyces cerevisiae, was performed with the ethanolic extract, dichloromethane fraction and stigmasterol isolated from the leaves of C. pallida. Mutagenic activity was evaluated by the Salmonella/microsome assay (Ames test), using the Salmonella typhimurium tester strains TA100, TA98, TA97 and TA102, with (+S9) and without (-S9) metabolization, by the preincubation method. All samples showed estrogenic activity, mainly stigmasterol. The ethanolic extract from C. pallida leaves showed mutagenic activity in the TA98 strain (-S9), whereas dichloromethane fraction and stigmasterol were found devoid of activity. Considering the excellent estrogenic activity performed by stigmasterol in the RYA associated with the absence of mutagenic activity when evaluated by the Ames test, stigmasterol becomes a strong candidate to be used in hormone replacement therapy during menopause.

  13. SU-F-BRF-13: Investigating the Feasibility of Accurate Dose Measurement in a Deforming Radiochromic Dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Juang, T [Medical Physics Graduate Program, Duke University Medical Center, Durham, NC (United States); Adamovics, J [Rider University, Skillman, NJ (United States); Oldham, M [Duke University Medical Center, Durham, NC (United States)

    2014-06-15

    Purpose: Presage-Def, a deformable radiochromic 3D dosimeter, has been previously shown to have potential for validating deformable image registration algorithms. This work extends this effort to investigate the feasibility of using Presage-Def to validate dose-accumulation algorithms in deforming structures. Methods: Two cylindrical Presage-Def dosimeters (8cm diameter, 4.5cm length) were irradiated in a water-bath with a simple 4-field box treatment. Isocentric dose was 20Gy. One dosimeter served as control (no deformation) while the other was laterally compressed during irradiation by 21%. Both dosimeters were imaged before and after irradiation with a fast (∼10 minutes for 1mm isotropic resolution), broad beam, high resolution optical-CT scanner. Measured dose distributions were compared to corresponding distributions calculated by a commissioned Eclipse planning system. Accuracy in the control was evaluated with 3D gamma (3%/3mm). The dose distribution calculated for the compressed dosimeter in the irradiation geometry cannot be directly compared via profiles or 3D gamma to the measured distribution, which deforms with release from compression. Thus, accuracy under deformation was determined by comparing integral dose within the high dose region of the deformed dosimeter distribution versus calculated dose. Dose profiles were used to study temporal stability of measured dose distributions. Results: Good dose agreement was demonstrated in the control with a 3D gamma passing rate of 96.6%. For the dosimeter irradiated under compression, the measured integral dose in the high dose region (518.0Gy*cm3) was within 6% of the Eclipse-calculated integral dose (549.4Gy*cm3). Elevated signal was noted on the dosimeter edge in the direction of compression. Change in dosimeter signal over 1.5 hours was ≤2.7%, and the relative dose distribution remained stable over this period of time. Conclusion: Presage-Def is promising as a 3D dosimeter capable of accurately

  14. Accurate Laboratory Measurements of Vibration-Rotation Transitions of 36ArH^+ and 38ArH+

    Science.gov (United States)

    Cueto, Maite; Cernicharo, Jose; Herrero, Victor Jose; Tanarro, Isabel; Domenech, Jose Luis

    2014-06-01

    The protonated Ar ion 36ArH^+ has recently been identified in space, in the Crab Nebula, from Herschel spectra. Its R(0) and R(1) transitions lie at 617.5 and 1234.6 GHz, respectively, where atmospheric transmission is rather poor, even for a site as good as that of ALMA. As an alternative, especially after the end of the Herschel mission, rovibrational transitions of ArH^+ could be observed in absorption against bright background sources such as the galactic center, or other objects. We report on accurate laboratory wavenumber measurements of 19 lines of the v=1-0 band of 36ArH^+ and 38ArH^+, using a hollow cathode discharge cell, a difference frequency laser spectrometer and Ar with natural isotopic composition. Of those lines, only eight had been reported before and with much less accuracy. The data have also been used in a Dunham-type global fit of all published laboratory data (IR and sub-mm) of all isotopologues. Barlow et al., Science, 342, 1343 (2013) R.R. Filgueira and C.E. Blom, J. Mol. Spectrosc., 127, 279 (1988) M. Cueto et al, Astrophys. J. Lett, 783, L5 (2014)

  15. Cannulation time is a more accurate measure of cannulation difficulty in endoscopic retrograde cholangiopancreatography than the number of attempts.

    Science.gov (United States)

    Tian, Chenlu; Gamboa, Anthony; Chaudhury, Biswashree; Willingham, Field F; Keilin, Steve; Cai, Qiang

    2013-11-01

    Cannulation of the common bile duct (CBD) is the initial and sometime challenging step in endoscopic retrograde cholangiopancreatography (ERCP) procedure. Endoscopists often use cannulation attempts and cannulation time to grade cannulation difficulty, but a standard system has yet to be established. The objective of this study was to compare cannulation times with numbers of cannulation attempts, as measures of cannulation difficulty. We conducted a prospective study in a tertiary referral center, enrolling 58 patients who were undergoing ERCP for a variety of indications. Cannulation time and the number of cannulation attempts were recorded for each patient. A subset of 14 ERCPs had two observers assessing attempts at cannulation. Cannulation time, number of attempts and inter-observer variability in assessment of attempts were compared and studied. The degree of agreement between two the methods (cannulation times and number of cannulation attempts) was unacceptable. There were considerable discrepancies between attempt tallies from two observers but the mean difference was statistically insignificant. The grade of cannulation difficulty for a given ERCP procedure may differ when different methods are used (total cannulation time vs number of attempts); thus, grading by different methods should not be used interchangeably. Cannulation time is a more objective and more accurate assessment tool for grading cannulation difficulty than the number of attempts to cannulate the papilla.

  16. Urine color, osmolality and specific electrical conductance are not accurate measures of hydration status during postexercise rehydration.

    Science.gov (United States)

    Kovacs, E M; Senden, J M; Brouns, F

    1999-03-01

    The aim of the study was to determine whether urine color, osmolality and specific electrical conductance (SEC) provide an accurate index of hydration status and of fluid requirements during the recovery phase after an acute exercise-induced dehydration. eight well-trained healthy males were dehydrated about 3% of body mass, 3 times, by cycling in the heat. To rehydrate after exercise, three types of drinks frequently consumed by athletes postexercise, i.e. a caffeinated soft drink (CC), a mineral water (MW), or a carbohydrate-electrolyte solution (CES) were ingested ad libitum and in randomized cross-over design during the first 2 hrs of an observation period lasting 6 hrs. urine was sampled each hour for determination of color, osmolality and SEC. Net rehydration was calculated from fluid intake and fluid loss by sweat and urine. Fluid intake amounted 2.6 +/- 0.2 kg for CC, 2.2 +/- 0.2 kg for MW and 2.8 +/- 0.3 kg for CES representing 116%, 96% and 127% of fluid lost by sweat. Urine output showed a negative correlation with color, osmolality and SEC (p 0.05). Urine color, SEC and osmolality are poor indicators of hydration status measured from the balance between fluid intake and urine output up to 6 hrs postexercise.

  17. Determination of well flat band condition in thin film FDSOI transistors using C-V measurement for accurate parameter extraction

    Science.gov (United States)

    Mohamad, B.; Leroux, C.; Reimbold, G.; Ghibaudo, G.

    2018-01-01

    For advanced gate stacks, effective work function (WFeff) and equivalent oxide thickness (EOT) are fundamental parameters for technology optimization. On FDSOI transistors, and contrary to the bulk technologies, while EOT can still be extracted at strong inversion from the typical gate-to-channel capacitance (Cgc), it is no longer the case for WFeff due to the disappearance of an observable flat band condition on capacitance characteristics. In this work, a new experimental method, the Cbg(VBG) characteristic, is proposed in order to extract the well flat band condition (VFB, W). This characteristic enables an accurate and direct evaluation of WFeff. Moreover, using the previous extraction of the gate oxide (tfox), and buried oxide (tbox) from typical capacitance characteristics (Cgc and Cbc), it allows the extraction of the channel thickness (tch). Furthermore, the measurement of the well flat band condition on Cbg(VBG) characteristics for two different Si and SiGe channel also proves the existence of a dipole at the SiGe/SiO2 interface. article>

  18. On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Kristie Cooper; Gary Pickrell; Anbo Wang

    2005-11-01

    This report summarizes technical progress April-September 2005 on the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Due to the difficulties described on the last report, field testing of the BPDI system has not continued to date. However, we have developed an alternative high temperature sensing solution, which is described in this report. The sensing system will be installed and tested at TECO's Polk Power Station. Following a site visit in June 2005, our efforts have been focused on preparing for that field test, including he design of the sensor mechanical packaging, sensor electronics, the data transfer module, and the necessary software codes to accommodate this application.. We are currently ready to start sensor fabrication.

  19. Challenges associated with drunk driving measurement: combining police and self-reported data to estimate an accurate prevalence in Brazil.

    Science.gov (United States)

    Sousa, Tanara; Lunnen, Jeffrey C; Gonçalves, Veralice; Schmitz, Aurinez; Pasa, Graciela; Bastos, Tamires; Sripad, Pooja; Chandran, Aruna; Pechansky, Flavio

    2013-12-01

    Drunk driving is an important risk factor for road traffic crashes, injuries and deaths. After June 2008, all drivers in Brazil were subject to a "Zero Tolerance Law" with a set breath alcohol concentration of 0.1 mg/L of air. However, a loophole in this law enabled drivers to refuse breath or blood alcohol testing as it may self-incriminate. The reported prevalence of drunk driving is therefore likely a gross underestimate in many cities. To compare the prevalence of drunk driving gathered from police reports to the prevalence gathered from self-reported questionnaires administered at police sobriety roadblocks in two Brazilian capital cities, and to estimate a more accurate prevalence of drunk driving utilizing three correction techniques based upon information from those questionnaires. In August 2011 and January-February 2012, researchers from the Centre for Drug and Alcohol Research at the Universidade Federal do Rio Grande do Sul administered a roadside interview on drunk driving practices to 805 voluntary participants in the Brazilian capital cities of Palmas and Teresina. Three techniques which include measures such as the number of persons reporting alcohol consumption in the last six hours but who had refused breath testing were used to estimate the prevalence of drunk driving. The prevalence of persons testing positive for alcohol on their breath was 8.8% and 5.0% in Palmas and Teresina respectively. Utilizing a correction technique we calculated that a more accurate prevalence in these sites may be as high as 28.2% and 28.7%. In both cities, about 60% of drivers who self-reported having drank within six hours of being stopped by the police either refused to perform breathalyser testing; fled the sobriety roadblock; or were not offered the test, compared to about 30% of drivers that said they had not been drinking. Despite the reduction of the legal limit for drunk driving stipulated by the "Zero Tolerance Law," loopholes in the legislation permit many

  20. Do measures of surgical effectiveness at 1 year after lumbar spine surgery accurately predict 2-year outcomes?

    Science.gov (United States)

    Adogwa, Owoicho; Elsamadicy, Aladine A; Han, Jing L; Cheng, Joseph; Karikari, Isaac; Bagley, Carlos A

    2016-12-01

    OBJECTIVE With the recent passage of the Patient Protection and Affordable Care Act, there has been a dramatic shift toward critical analyses of quality and longitudinal assessment of subjective and objective outcomes after lumbar spine surgery. Accordingly, the emergence and routine use of real-world institutional registries have been vital to the longitudinal assessment of quality. However, prospectively obtaining longitudinal outcomes for patients at 24 months after spine surgery remains a challenge. The aim of this study was to assess if 12-month measures of treatment effectiveness accurately predict long-term outcomes (24 months). METHODS A nationwide, multiinstitutional, prospective spine outcomes registry was used for this study. Enrollment criteria included available demographic, surgical, and clinical outcomes data. All patients had prospectively collected outcomes measures and a minimum 2-year follow-up. Patient-reported outcomes instruments (Oswestry Disability Index [ODI], SF-36, and visual analog scale [VAS]-back pain/leg pain) were completed before surgery and then at 3, 6, 12, and 24 months after surgery. The Health Transition Index of the SF-36 was used to determine the 1- and 2-year minimum clinically important difference (MCID), and logistic regression modeling was performed to determine if achieving MCID at 1 year adequately predicted improvement and achievement of MCID at 24 months. RESULTS The study group included 969 patients: 300 patients underwent anterior lumbar interbody fusion (ALIF), 606 patients underwent transforaminal lumbar interbody fusion (TLIF), and 63 patients underwent lateral interbody fusion (LLIF). There was a significant correlation between the 12- and 24-month ODI (r = 0.82; p MCID thresholds for ODI at 12 months were 13-fold (p MCID at 24 months. Similarly, for the TLIF and LLIF cohorts, patients achieving MCID thresholds for ODI at 12 months were 13-fold and 14-fold (p MCID at 24 months. Outcome measures obtained at 12

  1. Precise and accurate measurement of U and Th isotopes via ICP-MS using a single solution

    Science.gov (United States)

    Mertz-Kraus, R.; Sharp, W. D.; Ludwig, K. R.

    2012-04-01

    , allowing the sample's 238U/235U ratio to be measured. In step 3, we monitor peak-tails at half-mass positions (229.5, 231.5, 234.5) and on mass 237 while aspirating sample solution. Tail measurement requires a distinct cup configuration to maintain 238U in the cups; however, no sample is consumed during automated cup reconfiguration. We monitor the accuracy of 234U/238U ratios using CRM 145, which gives a weighted mean atom ratio of (5.2846 ± 0.0029) - 10-5 (all errors 2σ), consistent with published and reference values. The reproducibility of 230Th/238U ratios is monitored using the Schwartzwalder Mine secular-equilibrium standard (SM). We detect no bias in 230Th/238U or 234U/238U ratios measured for SM at beam intensities ranging over a factor of four, consistent with accurate correction for IC yields. Aladdin's cave coral (AC-1) was analyzed to check our ICP-MS method (and the preceding purification by ion exchange) on a carbonate and yields a mean age of 125.43 ± 0.38 ka, in agreement with published values. We are currently applying the method to corals, speleothems, pedogenic coatings, and tufas.

  2. A technique for accurately determining the cusp-region polar cap boundary using SuperDARN HF radar measurements

    Directory of Open Access Journals (Sweden)

    G. Chisham

    Full Text Available Accurately measuring the location and motion of the polar cap boundary (PCB in the high-latitude ionosphere can be crucial for studies concerned with the dynamics of the polar cap, e.g. the measurement of reconnection rates. The Doppler spectral width characteristics of backscatter received by the SuperDARN HF radars have been previously used for locating and tracking the PCB in the cusp region. The boundary is generally observed in meridional beams of the SuperDARN radars and appears as a distinct change between low spectral width values observed equatorward of the cusp region, and high, but variable spectral width values observed within the cusp region. To identify the spectral width boundary (SWB between these two regions, a simple algorithm employing a spectral width threshold has often been applied to the data. However, there is not, as yet, a standard algorithm, or spectral width threshold, which is universally applied. Nor has there been any rigorous assessment of the accuracy of this method of boundary determination. This study applies a series of threshold algorithms to a simulated cusp-region spectral width data set, to assess the accuracy of different algorithms. This shows that simple threshold algorithms correctly identify the boundary location in, at the most, 50% of the cases and that the average boundary error is at least ~ 1–2 range gates (~ 1° latitude. It transpires that spatial and temporal smoothing of the spectral width data (e.g. by median filtering, before application of a threshold algorithm can increase the boundary determination accuracy to over 95% and the average boundary error to much less than a range gate. However, this is sometimes at the cost of temporal resolution in the motion of the boundary location. The algorithms are also applied to a year’s worth of spectral width data from the cusp ionosphere, measured by the Halley SuperDARN radar in Antarctica. This analysis highlights the increased accuracy of

  3. A technique for accurately determining the cusp-region polar cap boundary using SuperDARN HF radar measurements

    Directory of Open Access Journals (Sweden)

    G. Chisham

    2003-04-01

    Full Text Available Accurately measuring the location and motion of the polar cap boundary (PCB in the high-latitude ionosphere can be crucial for studies concerned with the dynamics of the polar cap, e.g. the measurement of reconnection rates. The Doppler spectral width characteristics of backscatter received by the SuperDARN HF radars have been previously used for locating and tracking the PCB in the cusp region. The boundary is generally observed in meridional beams of the SuperDARN radars and appears as a distinct change between low spectral width values observed equatorward of the cusp region, and high, but variable spectral width values observed within the cusp region. To identify the spectral width boundary (SWB between these two regions, a simple algorithm employing a spectral width threshold has often been applied to the data. However, there is not, as yet, a standard algorithm, or spectral width threshold, which is universally applied. Nor has there been any rigorous assessment of the accuracy of this method of boundary determination. This study applies a series of threshold algorithms to a simulated cusp-region spectral width data set, to assess the accuracy of different algorithms. This shows that simple threshold algorithms correctly identify the boundary location in, at the most, 50% of the cases and that the average boundary error is at least ~ 1–2 range gates (~ 1° latitude. It transpires that spatial and temporal smoothing of the spectral width data (e.g. by median filtering, before application of a threshold algorithm can increase the boundary determination accuracy to over 95% and the average boundary error to much less than a range gate. However, this is sometimes at the cost of temporal resolution in the motion of the boundary location. The algorithms are also applied to a year’s worth of spectral width data from the cusp ionosphere, measured by the Halley SuperDARN radar in Antarctica. This analysis highlights the increased accuracy of

  4. Skin mechanics measured in vivo using torsion: a new and accurate model more sensitive to age, sex and moisturizing treatment.

    Science.gov (United States)

    Salter, D C; McArthur, H C; Crosse, J E; Dickens, A D

    1993-10-01

    Summary Measurements of skin mechanics are required to understand better cracking and flaking of the epidermis and loss of 'elasticity'with age in the dermis. Improvements in torsional testing are described here. The resulting data was fitted to algebraic models, the parameters of which can serve both as a concise description of the responses and as a means of relating them to skin structure and physiology. This investigation looks into the suitability of seven such algebraic models. Five of the models examined here appear to be new. Using the commercially available Dia-Stron DTM Torque Meter with our own software, model parameters were studied as indicators of the effects of age and sex in 41 people, and of skin moisturizing treatments in a further 10 people. The two models in the literature were both found to be substantially less accurate and sensitive representations of experimental data than one of the new models proposed here based on the Weibull distribution. This 'WB model'was consistently the one best able to distinguish differences and detect changes which were statistically significant. The WB model appears to be the most powerful and efficient available. Use of this model makes it possible to demonstrate in vivo a statistically significant mechanical difference between male and pre-menopausal female skin using only one parameter (p= 0.0163, with 18 males and 19 females) and to demonstrate a statistically significant mechanical difference between successive decades of age in female skin using only one parameter (p= 0.0124, n= 24). The two parameters of the model most sensitive to skin structure, function and treatment have been combined to form the axes of a 'Skin condition chart'. Any person can be located on this chart at a point indicating their overall skin condition in mechanical terms and any changes in that condition can be clearly demonstrated by movement across the plot.

  5. Echocardiographic measurements alone do not provide accurate non-invasive selection of annuloplasty band size for robotic mitral valve repair.

    Science.gov (United States)

    Cook, Richard C; Nifong, L Wiley; Lashley, Graham G; Duncan, Robert A; Campbell, Julie A; Law, Y Brandon; Chitwood, W Randolph

    2006-07-01

    Successful mitral valve repair (MVP) is dependent on accurate annuloplasty band sizing. This is difficult and time-consuming when performed via port-access, or through a 4-cm minithoracotomy used in robotically assisted MVP. With the goal of moving toward a less-invasive approach and minimizing cross-clamp time, an attempt was made to determine annuloplasty band size using transesophageal echocardiography (TEE) alone. The intertrigonal distance (ITD) was determined by dividing the left ventricular outflow tract diameter (LVOT: measured on standard midesophageal aortic valve long-axis view) by 0.8. The ITD was compared to a nomogram developed to select the best Cosgrove-Edwards annuloplasty band size. Between July and October, 2004, 11 patients (mean age 52.6 +/- 17.9 years; four Barlow's valves with bileaflet prolapse, four posterior leaflet prolapses, one anterior leaflet prolapse, one rheumatic, one dilated annulus) undergoing robotically assisted MVP had the annuloplasty band chosen using TEE alone. Seven patients (63.6%) had no or mild mitral regurgitation (MR) on postoperative TEE. Three patients (27.2%) had some systolic anterior motion (SAM), with one (Barlow's valve) requiring a second repair (same operation). One patient (9.1%, rheumatic) had grade 2+ MR on postoperative TEE. In this small case series, a substantial proportion of patients had suboptimal immediate postoperative results. This suggests that selection of the annuloplasty band should not be based on a single echocardiographic variable as it depends on the etiology of the MR, and other dimensions of the mitral valve. Further studies are ongoing to develop a non-invasive method for the selection of annuloplasty band size.

  6. A Feasibility Study for Measuring Accurate Chest Compression Depth and Rate on Soft Surfaces Using Two Accelerometers and Spectral Analysis

    Directory of Open Access Journals (Sweden)

    Sofía Ruiz de Gauna

    2016-01-01

    Full Text Available Background. Cardiopulmonary resuscitation (CPR feedback devices are being increasingly used. However, current accelerometer-based devices overestimate chest displacement when CPR is performed on soft surfaces, which may lead to insufficient compression depth. Aim. To assess the performance of a new algorithm for measuring compression depth and rate based on two accelerometers in a simulated resuscitation scenario. Materials and Methods. Compressions were provided to a manikin on two mattresses, foam and sprung, with and without a backboard. One accelerometer was placed on the chest and the second at the manikin’s back. Chest displacement and mattress displacement were calculated from the spectral analysis of the corresponding acceleration every 2 seconds and subtracted to compute the actual sternal-spinal displacement. Compression rate was obtained from the chest acceleration. Results. Median unsigned error in depth was 2.1 mm (4.4%. Error was 2.4 mm in the foam and 1.7 mm in the sprung mattress (p<0.001. Error was 3.1/2.0 mm and 1.8/1.6 mm with/without backboard for foam and sprung, respectively (p<0.001. Median error in rate was 0.9 cpm (1.0%, with no significant differences between test conditions. Conclusion. The system provided accurate feedback on chest compression depth and rate on soft surfaces. Our solution compensated mattress displacement, avoiding overestimation of compression depth when CPR is performed on soft surfaces.

  7. Norovirus recombination

    National Research Council Canada - National Science Library

    Bull, Rowena A; Tanaka, Mark M; White, Peter A

    2007-01-01

    ...{at}unsw.edu.au RNA recombination is a significant driving force in viral evolution. Increased awareness of recombination within the genus Norovirus of the family Calicivirus has led to a rise in the identification of norovirus (NoV...

  8. S3 HMBC hetero: Spin-State-Selective HMBC for accurate measurement of long-range heteronuclear coupling constants

    DEFF Research Database (Denmark)

    Hoeck, Casper; Gotfredsen, Charlotte Held; Sørensen, Ole W.

    2017-01-01

    A novel method, Spin-State-Selective (S3) HMBC hetero, for accurate measurement of heteronuclear coupling constants is introduced. The method extends the S3 HMBC technique for measurement of homonuclear coupling constants by appending a pulse sequence element that interchanges the polarization...

  9. Preparation and validation of radio iodinated recombinant human IL-10 for the measurement of natural human antibodies against IL-10

    DEFF Research Database (Denmark)

    de Lemos Rieper, Carina; Galle, Pia; Svenson, Morten

    2009-01-01

    Radio iodinated recombinant human IL-10 was prepared and validated for the measurement of natural human anti-IL-10 antibodies. Iodination of IL-10 was accomplished by means of the chloramine-T method. The crude tracer was purified by size chromatography as homo-dimeric IL-10 with a specific...... activity of 75 cpm/pg. Validation of the tracer confirmed preserved antibody epitopes and receptor binding ability. A robust Radio Immuno Assay (RIA) was developed and validated to detect natural human anti-IL-10 antibodies based on the formation of (125)I-labeled IL-10-IgG complexes in solution...... and separation of the complexes by chromatography on mini-columns. The RIA was applied to 3360 plasma samples derived from normal Danish blood donors. Generally, IL-10 did not bind to plasma factors other than natural anti-IL-10 IgG antibodies. The prevalence of donors high positive for antibodies against IL-10...

  10. Dose {sup 131}I radioactivity interfere with thyroglobulin measurement in patients undergoing radioactive iodine therapy with recombinant human TSH?

    Energy Technology Data Exchange (ETDEWEB)

    Park, So Hyun; Bang, Ji In; Lee, Ho Young; Kim, Sang Eun [Dept. of Nuclear Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2015-06-15

    Recombinant human thyroid-stimulating hormone (rhTSH) is widely used in radioactive iodine therapy (RIT) to avoid side effects caused by hypothyroidism during the therapy. Owing to RIT with rhTSH, serum thyroglobulin (Tg) is measured with high 131I concentrations. It is of concern that the relatively high energy of 131I could interfere with Tg measurement using the immunoradiometric assay (IRMA). We investigated the effect of 131I administration on Tg measurement with IRMA after RIT. A total of 67 patients with thyroid cancer were analysed retrospectively. All patients had undergone rhTSH stimulation for RIT. The patients’ sera were sampled 2 days after 131I administration and divided into two portions: for Tg measurements on days 2 and 32 after 131I administration. The count per minute (CPM) of whole serum (200 μl) was also measured at each time point. Student’s paired t-test and Pearson’s correlation analyses were performed for statistical analysis. Serum Tg levels were significantly concordant between days 2 and 32, irrespective of the serum CPM. Subgroup analysis was performed by classification based on the 131I dose. No difference was noted between the results of the two groups. IRMA using 125I did not show interference from 131I in the serum of patients stimulated by rhTSH.

  11. Cross calibration of the Siemens mMR: easily acquired accurate PET phantom measurements, long term stability and reproducibility

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Sune H [Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Jakoby, Bjorn [University of Surrey, Guildford (United Kingdom); Hansen, Adam Espe; Svalling, Susanne; Klausen, Thomas L [Rigshospitalet, University of Copenhagen, Copenhagen (Denmark)

    2015-05-18

    We present a quick and easy method to perform quantitatively accurate PET scans of typical water-filled PET plastic shell phantoms on the Siemens mMR PET/MR scanner. We perform regular cross calibrations (Xcals) of our PET scanners, including the Siemens mMR PET/MR, with a Siemens mCT water phantom. We evaluate the mMR cross calibration stability over a 3-year period. Recently, the mMR software (VB20P) offered the option of using predefined μ-maps. We evaluated this option by using either the predefined μ-map of the long mMR water phantom or a system-integrated user defined CT-based μ-map of the mCT water phantom used for Xcal. On 54 cross calibrations that were acquired over 3 years, the mMR on average underestimated the concentration by 16% due to the use of MR-based μ-maps. The mMR produced the narrowest range and lowest standard deviation of the Xcal ratios, implying it and is the most stable of the 6 scanners included in this study over a 3 year period. With correctly segmented μ-maps, the mMR produced Xcal ratios of 1.00-1.02, well within the acceptance range [0.95-1.05]. Measuring the concentration in a centrally placed cylindrical VOI allows for some robustness against misregistration of the μ-maps but it should be no more than a few millimeters in the x-y plane, while the tolerance is larger on the z-axis (when, as always with PET, keeping clear of the axial edges of the FOV). The mMR is the most stable scanner in this study and the mean underestimation is no longer an issue with the easily accessible μ-map, which in all 7 tests resulted in correct Xcal ratios. We will share the user defined μ-map of the mCT phantom and the protocol with interested mMR users.

  12. The antibacterial activity of Virkon measured by colony growth and bioluminescence of lux recombinant Listeria monocytogenes.

    Science.gov (United States)

    Walker, A J; Holah, J T; Denyer, S P; Stewart, G S

    1992-08-01

    Concentration exponents for the broad spectrum antimicrobial Virkon were determined for Listeria monocytogenes using both plate counts and bioluminescence measurements; the values of 3.15 and 2.6 indicate a close equivalence between these two measurement procedures. Virkon is an effective biocide for L. monocytogenes at the manufacturer's in-use concentration of 1%.

  13. Colorimetric activity measurement of a recombinant putrescine N-methyltransferase from Datura stramonium.

    Science.gov (United States)

    Biastoff, Stefan; Teuber, Michael; Zhou, Zhaohui Sunny; Dräger, Birgit

    2006-10-01

    Putrescine N-methyltransferase (PMT, EC 2.1.1.53) catalyses the S-adenosyl- L-methionine (SAM or AdoMet)-dependent methylation of putrescine to N-methylputrescine within the biosynthetic pathways of calystegines, nicotine, and tropane alkaloids in medicinal plants and produces S-adenosyl- L-homocysteine (SAH or AdoHcy). Determination of PMT activity was time-consuming and hardly reproducible in the past because it required tedious separation steps after chemical derivatisation or radioactive labelling of N-methylputrescine. A convenient and accurate enzyme-coupled colorimetric assay is based on the conversion of SAH to homocysteine by 5'-methylthioadenosine/ S-adenosylhomocysteine nucleosidase (MTAN/SAHN, EC 3.2.2.9) and S-ribosylhomocysteine lyase (LuxS, EC 4.4.1.21). Homocysteine is quantified by 5,5'-dithiobis-2-nitrobenzoic acid. Putrescine was shown not to interfere with MTAN or LuxS. The colorimetric assay was validated by HPLC analysis. K(m) values determined by the assay, 108 microM for putrescine and 42 microM for SAM, are lower than the previously reported values, due to alleviation of PMT inhibition by SAH. DTNB:5,5'-dithiobis-2-nitrobenzoic acid LuxS: S-ribosylhomocysteine lyase MTAN:5'-methylthioadenosine nucleosidase PMT:putrescine N-methyltransferase SAH: S-adenosyl- L-homocysteine SAM: S-adenosyl- L-methionine TNB:2-nitro-5-thiobenzoic acid.

  14. Accurately measuring sea level change from space: an ESA Climate Change Initiative for MSL closure budget studies

    DEFF Research Database (Denmark)

    Legeais, Jean-Francois; Cazenave, Anny; Larnicol, Gille

    Sea level is a very sensitive index of climate change and variability. Sea level integrates the ocean warming, mountain glaciers and ice sheet melting. Understanding the sea level variability and changes implies an accurate monitoring of the sea level variable at climate scales, in addition...... to understanding the ocean variability and the exchanges between ocean, land, cryosphere, and atmosphere. That is why Sea Level is one of the Essential Climate Variables (ECV) selected in the frame of the ESA Climate Change Initiative (CCI) program. It aims at providing long-term monitoring of the sea level ECV...

  15. Accounting for Interference, Scattering, and Electrode Absorption to Make Accurate Internal Quantum Efficiency Measurements in Organic and Other Thin Solar Cells

    KAUST Repository

    Burkhard, George F.

    2010-05-31

    Accurately measuring internal quantum efficiency requires knowledge of absorption in the active layer of a solar cell. The experimentally accessible total absorption includes significant contributions from the electrodes and other nonactive layers. We suggest a straightforward method for calculating the active layer contribution that minimizes error by subtracting optically-modeled electrode absorption from experimentally measured total absorption. (Figure Presented) © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. A New CCI ECV Release (v2.0) to Accurately Measure the Sea Level Change (1993-2015)

    Science.gov (United States)

    Legeais, J.; Cazenave, A. A.; Ablain, M.; Gilles, G.; Johannessen, J. A.; Scharffenberg, M. G.; Timms, G.; Andersen, O. B.; Cipollini, P.; Roca, M.; Rudenko, S.; Fernandes, J.; Balmaseda, M.; Quartly, G.; Fenoglio Marc, L.; Meyssignac, B.; Benveniste, J.; Ambrozio, A.; Restano, M.

    2016-12-01

    Accurate monitoring of the sea level is required to better understand its variability and changes. Sea level is one of the Essential Climate Variables (ECV) selected in the frame of the ESA Climate Change Initiative (CCI) program. It aims at providing a long-term homogeneous and accurate sea level record. The needs and feedback of the climate research community have been collected and a first version of the sea level ECV product has been generated with the best algorithms and altimeter standards. This record (1993-2014) has been validated by the climate research community. Within phase II (2014-2016), the 15 partner consortium has prepared the production of a new reprocessed homogeneous and accurate altimeter sea level record which will be distributed in Autumn 2016. New level 2 altimeter standards developed and tested within the project as well as external contributions have been identified, processed and evaluated by comparison with a reference for different altimeter missions (TOPEX/Poseidon, Jason-1 & 2, ERS-1 & 2, Envisat and GFO). The main evolutions are associated with the wet troposphere correction (based on the GPD+ algorithm including inter calibration with respect to external sensors) but also to the orbit solutions (POE-E and GFZ15), the ERA-Interim based atmospheric corrections and the FES2014 ocean tide model. A new pole tide solution is used and anomalies are referenced to the MSS DTU15. The presentation will focus on the main achievements of the ESA CCI Sea Level project and on the description of the new SL_cci ECV release covering 1993-2015. The major steps required to produce the reprocessed 23 year climate time series will be described. The impacts of the selected level 2 altimeter standards on the SL_cci ECV have been assessed on different spatial scales (global, regional, mesoscale) and temporal scales (long-term, inter-annual, periodic). A significant improvement is expected compared to the current v1.1, with the main impacts observed on the

  17. Tomosynthesis can facilitate accurate measurement of joint space width under the condition of the oblique incidence of X-rays in patients with rheumatoid arthritis.

    Science.gov (United States)

    Ono, Yohei; Kashihara, Rina; Yasojima, Nobutoshi; Kasahara, Hideki; Shimizu, Yuka; Tamura, Kenichi; Tsutsumi, Kaori; Sutherland, Kenneth; Koike, Takao; Kamishima, Tamotsu

    2016-06-01

    Accurate evaluation of joint space width (JSW) is important in the assessment of rheumatoid arthritis (RA). In clinical radiography of bilateral hands, the oblique incidence of X-rays is unavoidable, which may cause perceptional or measurement error of JSW. The objective of this study was to examine whether tomosynthesis, a recently developed modality, can facilitate a more accurate evaluation of JSW than radiography under the condition of oblique incidence of X-rays. We investigated quantitative errors derived from the oblique incidence of X-rays by imaging phantoms simulating various finger joint spaces using radiographs and tomosynthesis images. We then compared the qualitative results of the modified total Sharp score of a total of 320 joints from 20 patients with RA between these modalities. A quantitative error was prominent when the location of the phantom was shifted along the JSW direction. Modified total Sharp scores of tomosynthesis images were significantly higher than those of radiography, that is to say JSW was regarded as narrower in tomosynthesis than in radiography when finger joints were located where the oblique incidence of X-rays is expected in the JSW direction. Tomosynthesis can facilitate accurate evaluation of JSW in finger joints of patients with RA, even with oblique incidence of X-rays. Accurate evaluation of JSW is necessary for the management of patients with RA. Through phantom and clinical studies, we demonstrate that tomosynthesis may achieve more accurate evaluation of JSW.

  18. Fast and accurate measurement of on-axis gain and on-axis polarization at a finite distance

    DEFF Research Database (Denmark)

    Pivnenko, S.; Breinbjerg, O.

    2013-01-01

    -field substitution technique in which the measurement distance is defined between the phase centres of the antennas. The location of the phase centre of the antenna under test (AUT) is found from a quick pattern measurement consisting of only four cuts including the main and diagonal planes. Additionally, in order...... to reduce the amount of measurement data and thus measurement time, the phase centre location is found on a sparse frequency grid and the values in the intermediate points are found by interpolation. The antenna polarization is determined from the amplitude/phase frequency sweeps with two orthogonal AUT...... orientations versus a polarization calibrated probe. A complete set of measurements for one AUT takes less than two hours. The measurement uncertainty for the gain is comparable to the one obtained with the near-field substitution technique and typically does not exceed 0.1 dB (1 sigma)....

  19. Recombinant factor C assay for measuring endotoxin in house dust: comparison with LAL, and (1 --> 3)-beta-D-glucans.

    Science.gov (United States)

    Alwis, K Udeni; Milton, Donald K

    2006-04-01

    Measurement of exposure to environmental endotoxin is frequently performed using a Limulus amebocyte lysate (LAL) based assay. Recently, a new method has become available with similar sensitivity and potentially greater specificity using recombinant Factor C (rFC) from the horseshoe crab Carcinoscorpius rotundicauda. A preliminary study was carried out to determine the comparability of LAL and rFC in measuring endotoxins in house dust for large scale epidemiologic studies. House dust samples were collected from family rooms by vacuuming 1 m2 of the center of the room. Sixty sieved house dust samples were assayed for endotoxin by LAL (Cambrex, KQCL lysate) and rFC (Pyrogene, Cambrex) and for (1 --> 3)-beta-D-glucans by ELISA. The resistant parallel line estimation was used for data analysis of LAL and rFC. A four-parameter logistic fit with inverse prediction was used to calculate (1 --> 3)-beta-D-glucan levels of the samples. The spike recovery was 113.63% (95% CI = 101.69, 125.57%) for LAL and 99.69% (95% CI = 90.14, 109.24%) for rFC assays. The LAL assay gave higher endotoxin estimates compared with rFC. The LAL and rFC estimates were highly correlated (r = 0.86, P LAL and rFC endotoxin estimates correlated with the LAL estimates (r = 0.51, P 3)-beta-D-glucans. LAL and rFC gave comparable results, hence either assay can be used for studies of endotoxin exposure. The current study shows that (1 --> 3)-beta-D-glucan is not a major factor interfering with endotoxin measurements in house dust using a Cambrex KQCL LAL preparation. Copyright 2006 Wiley-Liss, Inc.

  20. Unified Study of Recombination in Polymer:Fullerene Solar Cells Using Transient Absorption and Charge-Extraction Measurements.

    Science.gov (United States)

    Andersson, L Mattias; Melianas, Armantas; Infahasaeng, Yingyot; Tang, Zheng; Yartsev, Arkady; Inganäs, Olle; Sundström, Villy

    2013-06-20

    Recombination in the well-performing bulk heterojunction solar cell blend between the conjugated polymer TQ-1 and the substituted fullerene PCBM has been investigated with pump-probe transient absorption and charge extraction of photogenerated carriers (photo-CELIV). Both methods are shown to generate identical and overlapping data under appropriate experimental conditions. The dominant type of recombination is bimolecular with a rate constant of 7 × 10(-12) cm(-3) s(-1). This recombination rate is shown to be fully consistent with solar cell performance. Deviations from an ideal bimolecular recombination process, in this material system only observable at high pump fluences, are explained with a time-dependent charge-carrier mobility, and the implications of such a behavior for device development are discussed.

  1. Are real-ear measurements (REM) accurate when using the modified pressure with stored equalization (MPSE) method?

    Science.gov (United States)

    Shaw, Paul

    2010-06-01

    Audiologists typically verify hearing instrument fitting using real-ear measurements (REM). Recently the modified pressure with stored equalization method (MPSE) has been recommended for use when verifying open non-occluding hearing instruments. The MPSE method does not use a reference microphone to maintain loudspeaker output during real-ear measurements and is therefore susceptible to changes in the signal level at the client's ear which result from movement of the client's head and torso during the verification process. To determine the size of these errors, the real-ear unaided response (REUR) was measured prior to and following the fitting of a non-functioning hearing aid in the contralateral ear. Twenty young adults participated. Identical head positions for the two measurements should yield zero difference measures across all frequencies measured. Loudspeaker-to-client azimuths of 0 degrees and 45 degrees were investigated. Mean difference measures across the frequencies investigated were less than 1 dB for both azimuths with one standard deviation from these mean differences typically less than 1.5 dB. Results suggest that the MPSE method does not introduce clinically significant errors in real-ear measurements when verifying hearing instrument fitting in the population examined.

  2. An Investigation into the Required Equipment and Procedures for the Accurate Measurement of Pressure in Hydraulic Fluid Power Systems

    Science.gov (United States)

    1976-05-27

    acceptably .;ccurate measurements. -2 i i Additionially: it was insisted that measurement and accuract requirements be remoed foom testing standards...under the - full implications o1 those decisions. The first section of this - sport details the investigations that were conducted in ti-e quest for the

  3. Estrogenic effects of leachates from industrial waste landfills measured by a recombinant yeast assay and transcriptional analysis in Japanese medaka.

    Science.gov (United States)

    Kamata, Ryo; Shiraishi, Fujio; Nakajima, Daisuke; Kageyama, Shiho

    2011-01-25

    In Japan, the leachates from 'stable type' landfills for industrial wastes are not controlled, and this has given rise to concerns about the possible pollution of surrounding environmental waters, especially by endocrine disrupting chemicals leaching from plastic and rubber wastes. To accurately assess the estrogenic potential of the landfill leachates by both in vitro and in vivo approaches, we confirmed gene-transcriptional responses in recombinant yeast cells and in Japanese medaka fish to estrogenic compounds, and applied these transcription assays to leachate samples. The yeast carrying the estrogen receptor (ER) of medaka and an ER-mediated response pathway responded to both the natural estrogen, 17β-estradiol (E2), and an industrial compound, bisphenol A (BPA), and the effective concentration of BPA was about 2.0×10(3) times that of E2. Transcripts of all genes coding for precursors of yolk protein, vitellogenin (vtg1 and vtg2), and precursors of egg envelope subunit proteins, choriogenins (chgh and chgl), increased in a concentration dependent manner in the livers of male medaka exposed to BPA or E2, and, except for chgh, reached peaks at exposure times of 48h. Although many fish in control groups did not have vtg transcripts, the incidence of vtg transcriptions also increased in a concentration dependent manner with exposure. The minimum effective concentrations of BPA at 48h were 0.5mg/L for chgh and vtg2, 2mg/L for vtg1 and 4mg/L for chgl, while those of E2 were 10ng/L for chgh and chgl and 30ng/L for vtg1 and vtg2. All leachates sampled at 3 landfill sites exerted in vitro estrogenic action. The E2 equivalent of the most potent leachate was 375ng/L for the yeast ER assay. This leachate sample significantly increased the transcripts of chgh, vtg1 and vtg2, but not chgl, in the medaka. In addition, chemical analysis showed that bisphenol A, 4-tert-octylphenol and 4-nonylphenol were the main contributors to the estrogenicity of the leachates. This study

  4. The calorimetric wattmeter. An accurate method for power loss measurements in energy optimized apparatus and systems. Main report

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, P.; Madsen, K.D.

    2000-08-01

    A measurement system has been built, for Calorimetric Measurement of power in the range 1-50 watt, at test temperatures between 20 and 70 deg. C. This Measurement System is intended to provide a service to research and development engineers working with Power Electronics. Applications for the Measurement System are precision measurements of the power loss in circuits and components, e.g. coils, transformers and power electronics systems. Power losses in these types of apparatus are characteristically difficult to measure, because of the waveforms of current and voltage which occur, non-linear material properties, very small values of loss, and high efficiency. The main purpose of performing precision measurements is to enable verification of the loss values, and the basic loss mechanisms. Knowledge and improved models obtained in this way will enable improved simulations, which are important in connection with optimisation of the loss characteristics and energy performance of apparatus and systems. The principle of the wattmeter is to make a calorimetric measurement of the form of heat emitted inside a reference surface. An advanced control system is provided, to regulate the temperature inside the reference surface. The temperature gradient across the walls of the reference surface is also controlled, to ensure that all heat is removed from the space via the heat exchanger of the precision measurement system. The design of the wattmeter is flexible, so that several experimental methods may be employed. To further ensure precision measurements the operation conditions of the measurement heat transfer system are optimised to suit the value of power to be measured. Experiments have verified that the mesurement uncertainty is 59 mW in the power range 1 to 10 W, for a test temperature of 30% C. An offset of 60 mW has been observed in this range, giving a final uncertainty on the measured value of {+-} 30 mW. The uncertainty increases to 180 mW in the range 10 to 50 W

  5. Does body mass index accurately reflect body fat? A comparison of anthropometric measures in the longitudinal assessment of fat mass.

    Science.gov (United States)

    Phan, Thao-Ly T; Maresca, Michelle M; Hossain, Jobayer; Datto, George A

    2012-07-01

    To determine which anthropometric measure best correlates with change in fat mass (FM) over time. The authors performed a retrospective cohort study of 76 obese patients (mean body mass index [BMI] 38 kg/m(2) and mean age 13 years) presenting to an obesity clinic between 2005 and 2010. For each patient, during 2 visits, FM was measured by bioelectrical impedance analysis and the following measures obtained: BMI, waist circumference, hip circumference, and neck circumference. Correlation coefficients and linear regression analyses were calculated to examine the relationship between each measure and FM. Change in BMI correlated better with change in FM than any other measure and had the strongest effect on change in FM (P FM.

  6. Technical Note: How accurate can stalagmite formation temperatures be determined using vapour bubble radius measurements in fluid inclusions?

    DEFF Research Database (Denmark)

    Spadin, F.; Marti, Dominik; Hidalgo-Staub, R.

    2015-01-01

    -induced vapour bubbles inside the inclusions. A reliable method for precisely measuring the radius of vapour bubbles is presented. The method is applied to stalagmite samples for which the formation temperature is known. An assessment of the bubble radius measurement accuracy and how this error influences......Stalagmites are natural archives containing detailed information on continental climate variability of the past. Microthermometric measurements of fluid inclusion homogenisation temperatures allow determination of stalagmite formation temperatures by measuring the radius of stable laser...... the uncertainty in determining the formation temperature is provided. We demonstrate that the nominal homogenisation temperature of a single inclusion can be determined with an accuracy of ±0.25 ◦C, if the volume of the inclusion is larger than 105 µm3 . With this method, we could measure in a proof...

  7. Genetic Recombination

    Science.gov (United States)

    Whitehouse, H. L. K.

    1973-01-01

    Discusses the mechanisms of genetic recombination with particular emphasis on the study of the fungus Sordaria brevicollis. The study of recombination is facilitated by the use of mutants of this fungus in which the color of the ascospores is affected. (JR)

  8. Computerized tomography magnified bone windows are superior to standard soft tissue windows for accurate measurement of stone size: an in vitro and clinical study.

    Science.gov (United States)

    Eisner, Brian H; Kambadakone, Avinash; Monga, Manoj; Anderson, James K; Thoreson, Andrew A; Lee, Hang; Dretler, Stephen P; Sahani, Dushyant V

    2009-04-01

    We determined the most accurate method of measuring urinary stones on computerized tomography. For the in vitro portion of the study 24 calculi, including 12 calcium oxalate monohydrate and 12 uric acid stones, that had been previously collected at our clinic were measured manually with hand calipers as the gold standard measurement. The calculi were then embedded into human kidney-sized potatoes and scanned using 64-slice multidetector computerized tomography. Computerized tomography measurements were performed at 4 window settings, including standard soft tissue windows (window width-320 and window length-50), standard bone windows (window width-1120 and window length-300), 5.13x magnified soft tissue windows and 5.13x magnified bone windows. Maximum stone dimensions were recorded. For the in vivo portion of the study 41 patients with distal ureteral stones who underwent noncontrast computerized tomography and subsequently spontaneously passed the stones were analyzed. All analyzed stones were 100% calcium oxalate monohydrate or mixed, calcium based stones. Stones were prospectively collected at the clinic and the largest diameter was measured with digital calipers as the gold standard. This was compared to computerized tomography measurements using 4.0x magnified soft tissue windows and 4.0x magnified bone windows. Statistical comparisons were performed using Pearson's correlation and paired t test. In the in vitro portion of the study the most accurate measurements were obtained using 5.13x magnified bone windows with a mean 0.13 mm difference from caliper measurement (p = 0.6). Measurements performed in the soft tissue window with and without magnification, and in the bone window without magnification were significantly different from hand caliper measurements (mean difference 1.2, 1.9 and 1.4 mm, p = 0.003, window settings with magnification. For uric acid calculi the measurement error was observed only in standard soft tissue window settings. In vivo 4.0x

  9. Finite Element Modelling of a Field-Sensed Magnetic Suspended System for Accurate Proximity Measurement Based on a Sensor Fusion Algorithm with Unscented Kalman Filter.

    Science.gov (United States)

    Chowdhury, Amor; Sarjaš, Andrej

    2016-09-15

    The presented paper describes accurate distance measurement for a field-sensed magnetic suspension system. The proximity measurement is based on a Hall effect sensor. The proximity sensor is installed directly on the lower surface of the electro-magnet, which means that it is very sensitive to external magnetic influences and disturbances. External disturbances interfere with the information signal and reduce the usability and reliability of the proximity measurements and, consequently, the whole application operation. A sensor fusion algorithm is deployed for the aforementioned reasons. The sensor fusion algorithm is based on the Unscented Kalman Filter, where a nonlinear dynamic model was derived with the Finite Element Modelling approach. The advantage of such modelling is a more accurate dynamic model parameter estimation, especially in the case when the real structure, materials and dimensions of the real-time application are known. The novelty of the paper is the design of a compact electro-magnetic actuator with a built-in low cost proximity sensor for accurate proximity measurement of the magnetic object. The paper successively presents a modelling procedure with the finite element method, design and parameter settings of a sensor fusion algorithm with Unscented Kalman Filter and, finally, the implementation procedure and results of real-time operation.

  10. Finite Element Modelling of a Field-Sensed Magnetic Suspended System for Accurate Proximity Measurement Based on a Sensor Fusion Algorithm with Unscented Kalman Filter

    Science.gov (United States)

    Chowdhury, Amor; Sarjaš, Andrej

    2016-01-01

    The presented paper describes accurate distance measurement for a field-sensed magnetic suspension system. The proximity measurement is based on a Hall effect sensor. The proximity sensor is installed directly on the lower surface of the electro-magnet, which means that it is very sensitive to external magnetic influences and disturbances. External disturbances interfere with the information signal and reduce the usability and reliability of the proximity measurements and, consequently, the whole application operation. A sensor fusion algorithm is deployed for the aforementioned reasons. The sensor fusion algorithm is based on the Unscented Kalman Filter, where a nonlinear dynamic model was derived with the Finite Element Modelling approach. The advantage of such modelling is a more accurate dynamic model parameter estimation, especially in the case when the real structure, materials and dimensions of the real-time application are known. The novelty of the paper is the design of a compact electro-magnetic actuator with a built-in low cost proximity sensor for accurate proximity measurement of the magnetic object. The paper successively presents a modelling procedure with the finite element method, design and parameter settings of a sensor fusion algorithm with Unscented Kalman Filter and, finally, the implementation procedure and results of real-time operation. PMID:27649197

  11. Optimization and application of cooled avalanche photodiodes for spectroscopic fluctuation measurements with ultra-fast charge exchange recombination spectroscopy

    Science.gov (United States)

    Truong, D. D.; Fonck, R. J.; McKee, G. R.

    2016-11-01

    The Ultra-Fast Charge Exchange Recombination Spectroscopy (UF-CHERS) diagnostic is a highly specialized spectroscopic instrument with 2 spatial channels consisting of 8 spectral channels each and a resolution of ˜0.25 nm deployed at DIII-D to measure turbulent ion temperature fluctuations. Charge exchange emissions are obtained between 528 and 530 nm with 1 μs time resolution to study plasma instabilities. A primary challenge of extracting fluctuation measurements from raw UF-CHERS signals is photon and electronic noise. In order to reduce dark current, the Avalanche Photodiode (APD) detectors are thermo-electrically cooled. State-of-the-art components are used for the signal amplifiers and conditioners to minimize electronic noise. Due to the low incident photon power (≤1 nW), APDs with a gain of up to 300 are used to optimize the signal to noise ratio. Maximizing the APDs' gain while minimizing the excess noise factor (ENF) is essential since the total noise of the diagnostic sets a floor for the minimum level of detectable broadband fluctuations. The APDs' gain should be high enough that photon noise dominates electronic noise, but not excessive so that the ENF overwhelms plasma fluctuations. A new generation of cooled APDs and optimized preamplifiers exhibits significantly enhanced signal-to-noise compared to a previous generation. Experiments at DIII-D have allowed for characterization and optimization of the ENF vs. gain. A gain of ˜100 at 1700 V is found to be near optimal for most plasma conditions. Ion temperature and toroidal velocity fluctuations due to the edge harmonic oscillation in quiescent H-mode plasmas are presented to demonstrate UF-CHERS' capabilities.

  12. Can the SENSIMED Triggerfish(®) lens data be used as an accurate measure of intraocular pressure?

    Science.gov (United States)

    Vitish-Sharma, Parveen; Acheson, Austin G; Stead, Richard; Sharp, John; Abbas, Ali; Hovan, Marta; Maxwell-Armstrong, Charles; Guo, Boliang; King, Anthony J

    2017-04-09

    The SENSIMED Triggerfish(®) contact lens sensor (CLS) has an embedded micro-sensor that captures spontaneous circumferential changes at the corneoscleral junction and transmits them via an antenna to a device where these measurements are stored. During laparoscopic colorectal surgery, patients are placed in Trendelenburg position which has been shown to increase intraocular pressure (IOP). Laparoscopic colorectal surgery requires both pneumoperitoneum and Trendelenburg positioning; therefore, IOP can vary significantly. We aimed to assess whether circumferential changes in the corneoscleral area can be correlated to IOP changes measured using Tono-pen(®) XL applanation tonometer during laparoscopic colorectal surgery. Patients undergoing laparoscopic colorectal resections were included. On the day of surgery, baseline IOP was taken and the SENSIMED Triggerfish(®) CLS was then set up in one eye of the patient. During surgery (whilst under general anaesthetic), IOP measurements were taken in the contralateral eye using a Tono-pen(®) XL applanation tonometer every hour and any time the table was moved to record the fluctuations of IOP during surgery and any association with position change. The timings of these readings were documented. Twenty patients were included in this study (six males, 14 females). Average age was 64.6 years (SD = 16.3). The fluctuation in IOP measured in the reference eye ranged between 6.3 and 46.7 mmHg. The mean correlation coefficient between CLS output measurements and these IOP measurements was r = 0.291 (95% CI). Our results showed a weak correlation between the SENSIMED Triggerfish(®) CLS data output and IOP measurements taken using the Tono-pen(®) XL applanation tonometer. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  13. Advancing Solar Irradiance Measurement for Climate-Related Studies: Accurate Constraint on Direct Aerosol Radiative Effect (DARE)

    Science.gov (United States)

    Tsay, Si-Chee; Ji, Q. Jack

    2011-01-01

    Earth's climate is driven primarily by solar radiation. As summarized in various IPCC reports, the global average of radiative forcing for different agents and mechanisms, such as aerosols or CO2 doubling, is in the range of a few W/sq m. However, when solar irradiance is measured by broadband radiometers, such as the fleet of Eppley Precision Solar Pyranometers (PSP) and equivalent instrumentation employed worldwide, the measurement uncertainty is larger than 2% (e.g., WMO specification of pyranometer, 2008). Thus, out of the approx. 184 W/sq m (approx.263 W/sq m if cloud-free) surface solar insolation (Trenberth et al. 2009), the measurement uncertainty is greater than +/-3.6 W/sq m, overwhelming the climate change signals. To discern these signals, less than a 1 % measurement uncertainty is required and is currently achievable only by means of a newly developed methodology employing a modified PSP-like pyranometer and an updated calibration equation to account for its thermal effects (li and Tsay, 2010). In this talk, we will show that some auxiliary measurements, such as those from a collocated pyrgeometer or air temperature sensors, can help correct historical datasets. Additionally, we will also demonstrate that a pyrheliometer is not free of the thermal effect; therefore, comparing to a high cost yet still not thermal-effect-free "direct + diffuse" approach in measuring surface solar irradiance, our new method is more economical, and more likely to be suitable for correcting a wide variety of historical datasets. Modeling simulations will be presented that a corrected solar irradiance measurement has a significant impact on aerosol forcing, and thus plays an important role in climate studies.

  14. Is a standalone inertial measurement unit accurate and precise enough for quantification of movement symmetry in the horse?

    DEFF Research Database (Denmark)

    Brighton, Charlotte; Olsen, Emil; Pfau, Thilo

    2015-01-01

    Standalone ‘low-cost’ inertial measurement units (IMUs) could facilitate large-scale studies into establishing minimal important differences (MID) for orthopaedic deficits (lameness) in horses. We investigated accuracy and limits of agreement (LoA) after correction of magnitude-dependent differen......Standalone ‘low-cost’ inertial measurement units (IMUs) could facilitate large-scale studies into establishing minimal important differences (MID) for orthopaedic deficits (lameness) in horses. We investigated accuracy and limits of agreement (LoA) after correction of magnitude......-dependent differences of a standalone 6 degree-of-freedom IMU compared with an established IMU-based gait analysis system (MTx) in six horses for two anatomical landmarks (sacrum and sternum). Established symmetry measures were calculated from vertical displacement: symmetry index (SI), difference between minima (Min......, whereas MinDiff and MaxDiff values are less favourable. Future studies should investigate specific calibration and processing algorithms further improving standalone IMU performance....

  15. The readout of the LHC beam luminosity monitor Accurate shower energy measurements at a 40 MHz repetition rate

    CERN Document Server

    Manfredi, P F; Speziali, V; Traversi, G; Manghisoni, M; Re, V; Denes, P; Placidi, Massimo; Ratti, A; Turner, W C; Datte, P S; Millaud, J E

    2004-01-01

    The LHC beam luminosity monitor is based on the following principle. The neutrals that originate in LHC at every PP interaction develop showers of minimum ionizing particles in the absorbers placed in front of the separation dipoles. The shower energy, measured by suitable detectors in the absorbers is proportional to the number of neutral particles and, therefore, to the luminosity. The principle lends itself to a luminosity measurement on a bunch-by-bunch basis. However, to make such a measurement feasible, the system must comply with extremely stringent requirements. Its speed of operation must match the 40 MHz bunch repetition rate of LHC. Besides, the detector must stand extremely high radiation doses. This paper discusses the solutions adopted to comply with these requirements.

  16. Accurate perioperative flow measurement of the portal vein and hepatic and renal artery: A role for preoperative MRI?

    Energy Technology Data Exchange (ETDEWEB)

    Vermeulen, Mechteld A.R., E-mail: mar.vermeulen@vumc.nl [Department of Surgery, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Ligthart-Melis, Gerdien C., E-mail: g.ligthart-melis@vumc.nl [Department of Internal Medicine, Dietetics and Nutritional Sciences, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Buijsman, René, E-mail: renebuysman@gmail.com [Department of Surgery, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Siroen, Michiel P.C., E-mail: m.siroen6@upcmail.nl [Department of Surgery, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Poll, Marcel C.G. van de, E-mail: mcg.vandepoll@ah.unimaas.nl [Department of Surgery, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht (Netherlands); Boelens, Petra G., E-mail: p.boelens@mumc.nl [Department of Surgery, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht (Netherlands); Dejong, Cornelis H.C., E-mail: chc.dejong@mumc.nl [Department of Surgery, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht (Netherlands); Schaik, Cors van, E-mail: c.vanschaik@vumc.nl [Department of Radiology, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Hofman, Mark B.M., E-mail: mbm.hofman@vumc.nl [Department of Physics and Medical Technology, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands); Leeuwen, Paul A.M. van, E-mail: pam.vleeuwen@vumc.nl [Department of Surgery, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands)

    2012-09-15

    Background: Quantification of abdominal blood flow is essential for a variety of gastrointestinal and hepatic topics such as liver transplantation or metabolic flux measurement, but those need to be performed during surgery. It is not clear whether Duplex Doppler Ultrasound during surgery or MRI before surgery is the tool to choose. Objective: To examine whether preoperative evaluation of abdominal blood flow using MRI could prove to be a useful and reliable alternative for the perioperative sonographic approach. Methods: In this study portal and renal venous flow and hepatic arterial flow were sequentially quantified by preoperative MRI, preoperative and perioperative Duplex Doppler Ultrasound (DDUS). 55 Patients scheduled for major abdominal surgery were studied and methods and settings were compared. Additionally, average patient population values were compared. Results: Mean (±SD) plasmaflow measured by perioperative DDUS, preoperative DDUS and MRI, respectively was 433 ± 200/423 ± 162/507 ± 96 ml/min (portal vein); 96 ± 70/74 ± 41/108 ± 91 ml/min (hepatic artery); 248 ± 139/201 ± 118/219 ± 69 ml/min (renal vein). No differences between the different settings of DDUS measurement were detected. Equality of mean was observed for all measurements. Bland Altman Plots showed widespread margins. Hepatic arterial flow measurements correlated with each other, but portal and renal venous flow correlations were absent. Conclusions: Surgery and method (DDUS vs. MRI) do not affect mean flow values. Individual comparison is restricted due to wide range in measurements. Since MRI proves to be more reliable with respect to inter-observer variability, we recommend using mean MRI results in experimental setups.

  17. Technical Note: How accurate can stalagmite formation temperatures be determined using vapour bubble radius measurements in fluid inclusions?

    Directory of Open Access Journals (Sweden)

    F. Spadin

    2015-06-01

    Full Text Available Stalagmites are natural archives containing detailed information on continental climate variability of the past. Microthermometric measurements of fluid inclusion homogenisation temperatures allow determination of stalagmite formation temperatures by measuring the radius of stable laser-induced vapour bubbles inside the inclusions. A reliable method for precisely measuring the radius of vapour bubbles is presented. The method is applied to stalagmite samples for which the formation temperature is known. An assessment of the bubble radius measurement accuracy and how this error influences the uncertainty in determining the formation temperature is provided. We demonstrate that the nominal homogenisation temperature of a single inclusion can be determined with an accuracy of ±0.25 °C, if the volume of the inclusion is larger than 105 μm3. With this method, we could measure in a proof-of-principle investigation that the formation temperature of 10–20 yr old inclusions in a stalagmite taken from the Milandre cave is 9.87 ± 0.80 °C, while the mean annual surface temperature, that in the case of the Milandre cave correlates well with the cave temperature, was 9.6 ± 0.15 °C, calculated from actual measurements at that time, showing a very good agreement. Formation temperatures of inclusions formed during the last 450 yr are found in a temperature range between 8.4 and 9.6 °C, which corresponds to the calculated average surface temperature. Paleotemperatures can thus be determined within ±1.0 °C.

  18. Activity assays and immunoassays for plasma Renin and prorenin: information provided and precautions necessary for accurate measurement

    DEFF Research Database (Denmark)

    Campbell, Duncan J; Nussberger, Juerg; Stowasser, Michael

    2009-01-01

    BACKGROUND: Measurement of plasma renin is important for the clinical assessment of hypertensive patients. The most common methods for measuring plasma renin are the plasma renin activity (PRA) assay and the renin immunoassay. The clinical application of renin inhibitor therapy has thrown...... to renin inhibitor therapy, owing to the inhibitor promoting conversion of prorenin to an open conformation that is recognized by renin immunoassays. CONCLUSIONS: The successful application of renin assays to patient care requires that the clinician and the clinical chemist understand the information...

  19. NEW METHOD FOR ARRANGEMENT OF HIGH-ACCURATE DEVICES FOR MEASURING AND METERING LIQUID AND GAS FLOW RATE

    Directory of Open Access Journals (Sweden)

    I. E. Zuykov

    2009-01-01

    Full Text Available The paper presents results of a development and an industrial implementation of a new method for measuring liquid (water amount passing through measuring devices as a continuous flow by means of rotating blades. An algorithm of the device operation which serves as a basis for the method can be also used for designing devices for metering and control of gas consumption.The given method has its practical application in the electronic water meter developed at the «Elektronika» Plant of the RPC Integral.

  20. Accurate viscosity measurements of flowing aqueous glucose solutions with suspended scatterers using a dynamic light scattering approach with optical coherence tomography

    Science.gov (United States)

    Weatherbee, Andrew; Popov, Ivan; Vitkin, Alex

    2017-08-01

    The viscosity of turbid colloidal glucose solutions has been accurately determined from spectral domain optical coherence tomography (OCT) M-mode measurements and our recently developed OCT dynamic light scattering model. Results for various glucose concentrations, flow speeds, and flow angles are reported. The relative "combined standard uncertainty" uc(η) on the viscosity measurements was ±1% for the no-flow case and ±5% for the flow cases, a significant improvement in measurement robustness over previously published reports. The available literature data for the viscosity of pure water and our measurements differ by 1% (stagnant case) and 1.5% (flow cases), demonstrating good accuracy; similar agreement is seen across the measured glucose concentration range when compared to interpolated literature values. The developed technique may contribute toward eventual noninvasive glucose measurements in medicine.

  1. The use of electrolysis for accurate delta O-17 and delta O-18 isotope measurements in water

    NARCIS (Netherlands)

    Meijer, HAJ; Li, WJ

    1998-01-01

    We present a new system to measure the relative isotopic abundances of both rare isotopes of oxygen in water. Using electrolysis with CuSO4 as electrolyte, water is transformed into oxygen gas. This gas is subsequently analyzed with a standard Isotope Ratio Mass Spectrometer. We investigated the

  2. Accurate and Integrated Localization System for Indoor Environments Based on IEEE 802.11 Round-Trip Time Measurements

    Directory of Open Access Journals (Sweden)

    Lorenzo RubénMateo

    2010-01-01

    Full Text Available The presence of (Non line of Sight NLOS propagation paths has been considered the main drawback for localization schemes to estimate the position of a (Mobile User MU in an indoor environment. This paper presents a comprehensive wireless localization system based on (Round-Trip Time RTT measurements in an unmodified IEEE 802.11 wireless network. It overcomes the NLOS impairment by implementing the (Prior NLOS Measurements Correction PNMC technique. At first, the RTT measurements are performed with a novel electronic circuit avoiding the need for time synchronization between wireless nodes. At second, the distance between the MU and each reference device is estimated by using a simple linear regression function that best relates the RTT to the distance in (Line of Sight LOS. Assuming that LOS in an indoor environment is a simplification of reality hence, the PNMC technique is applied to correct the NLOS effect. At third, assuming known the position of the reference devices, a multilateration technique is implemented to obtain the MU position. Finally, the localization system coupled with measurements demonstrates that the system outperforms the conventional time-based indoor localization schemes without using any tracking technique such as Kalman filters or Bayesian methods.

  3. Atom interferometry experiments with lithium. Accurate measurement of the electric polarizability; Experiences d'interferometrie atomique avec le lithium. Mesure de precision de la polarisabilite electrique

    Energy Technology Data Exchange (ETDEWEB)

    Miffre, A

    2005-06-15

    Atom interferometers are very sensitive tools to make precise measurements of physical quantities. This study presents a measurement of the static electric polarizability of lithium by atom interferometry. Our result, {alpha} = (24.33 {+-} 0.16)*10{sup -30} m{sup 3}, improves by a factor 3 the most accurate measurements of this quantity. This work describes the tuning and the operation of a Mach-Zehnder atom interferometer in detail. The two interfering arms are separated by the elastic diffraction of the atomic wave by a laser standing wave, almost resonant with the first resonance transition of lithium atom. A set of experimental techniques, often complicated to implement, is necessary to build the experimental set-up. After a detailed study of the atom source (a supersonic beam of lithium seeded in argon), we present our experimental atom signals which exhibit a very high fringe visibility, up to 84.5 % for first order diffraction. A wide variety of signals has been observed by diffraction of the bosonic isotope at higher diffraction orders and by diffraction of the fermionic less abundant isotope. The quality of these signals is then used to do very accurate phase measurements. A first experiment investigates how the atom interferometer signals are modified by a magnetic field gradient. An absolute measurement of lithium atom electric polarizability is then achieved by applying a static electric field on one of the two interfering arms, separated by only 90 micrometers. The construction of such a capacitor, its alignment in the experimental set-up and its operation are fully detailed.We obtain a very accurate phase measurement of the induced Lo Surdo - Stark phase shift (0.07 % precision). For this first measurement, the final uncertainty on the electric polarizability of lithium is only 0.66 %, and is dominated by the uncertainty on the atom beam mean velocity, so that a further reduction of the uncertainty can be expected. (author)

  4. Accurate tissue area measurements with considerably reduced radiation dose achieved by patient-specific CT scan parameters

    DEFF Research Database (Denmark)

    Brandberg, J.; Bergelin, E.; Sjostrom, L.

    2008-01-01

    as compared with the integral dose by the standard diagnostic technique. The CT numbers of muscle tissue remained unchanged with reduced radiation dose. Image noise was on average 20.9 HU (Hounsfield units) for subjects with diameters of 31-35 cm and 11.2 HU for subjects with diameters in the range of 36......A low-dose technique was compared with a standard diagnostic technique for measuring areas of adipose and muscle tissue and CT numbers for muscles in a body composition application. The low-dose technique was intended to keep the expected deviation in the measured area of adipose and muscle tissue...... to dose technique. 17 patients - chosen to cover a wide range of diameters (31-47 cm) for both abdomen and thighs - were examined using both techniques. Tissue areas were compared, as were CT numbers...

  5. Does Pelletizing Catalysts Influence the Efficiency Number of Activity Measurements? Spectrochemical Engineering Considerations for an Accurate Operando Study

    DEFF Research Database (Denmark)

    Rasmussen, Søren Birk; Perez-Ferreras, Susana; Banares, Miguel A.

    2013-01-01

    Porosity is a factor affecting catalyst efficiency in pelletized form. This implies that care should be taken with uncritically relating activity measurements from transmission operando FTIR to final catalyst performance. lithe pelletizing pressure is excessive, a destruction of the pore structur...... and internal pore diffusion properties are considered in this paper for the evaluation of catalyst performance in, for example, operando reactors. Thus, it is demonstrated that with a pelletizing pressure of...

  6. Retrieving accurate temporal and spatial information about Taylor slug flows from non-invasive NIR photometry measurements

    Science.gov (United States)

    Helmers, Thorben; Thöming, Jorg; Mießner, Ulrich

    2017-11-01

    In this article, we introduce a novel approach to retrieve spatial- and time-resolved Taylor slug flow information from a single non-invasive photometric flow sensor. The presented approach uses disperse phase surface properties to retrieve the instantaneous velocity information from a single sensor's time-scaled signal. For this purpose, a photometric sensor system is simulated using a ray-tracing algorithm to calculate spatially resolved near-infrared transmission signals. At the signal position corresponding to the rear droplet cap, a correlation factor of the droplet's geometric properties is retrieved and used to extract the instantaneous droplet velocity from the real sensor's temporal transmission signal. Furthermore, a correlation for the rear cap geometry based on the a priori known total superficial flow velocity is developed, because the cap curvature is velocity sensitive itself. Our model for velocity derivation is validated, and measurements of a first prototype showcase the capability of the device. Long-term measurements visualize systematic fluctuations in droplet lengths, velocities, and frequencies that could otherwise, without the observation on a larger timescale, have been identified as measurement errors and not systematic phenomenas.

  7. Accurate mass measurements of {sup 26}Ne, {sup 26-3}Na, {sup 29-33}Mg performed with the MISTRAL spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Gaulard, C. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, CSNSM, IN2P3-CNRS and UPS, Batiment 108, F-91405 Orsay Campus (France)]. E-mail: gaulard@csnsm.in2p3.fr; Audi, G. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, CSNSM, IN2P3-CNRS and UPS, Batiment 108, F-91405 Orsay Campus (France); Bachelet, C. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, CSNSM, IN2P3-CNRS and UPS, Batiment 108, F-91405 Orsay Campus (France); Lunney, D. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, CSNSM, IN2P3-CNRS and UPS, Batiment 108, F-91405 Orsay Campus (France); Saint Simon, M. de [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, CSNSM, IN2P3-CNRS and UPS, Batiment 108, F-91405 Orsay Campus (France); Thibault, C. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, CSNSM, IN2P3-CNRS and UPS, Batiment 108, F-91405 Orsay Campus (France); Vieira, N. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, CSNSM, IN2P3-CNRS and UPS, Batiment 108, F-91405 Orsay Campus (France)

    2006-02-20

    The minuteness of the nuclear binding energy requires that mass measurements be highly precise and accurate. Here we report on new measurements of {sup 29-33}Mg and {sup 26}Na performed with the MISTRAL mass spectrometer at CERN's ISOLDE facility. Since mass measurements are prone to systematic errors, considerable effort has been devoted to their evaluation and elimination in order to achieve accuracy and not only precision. We have therefore conducted a campaign of measurements for calibration and error evaluation. As a result, we now have a satisfactory description of the MISTRAL calibration laws and error budget. We have applied our new understanding to previous measurements of {sup 26}Ne, {sup 26-3}Na and {sup 29,32}Mg for which re-evaluated values are reported.

  8. Accurate and stable equal-pressure measurements of water vapor transmission rate reaching the 10-6 g m-2 day-1 range

    Science.gov (United States)

    Nakano, Yoichiro; Yanase, Takashi; Nagahama, Taro; Yoshida, Hajime; Shimada, Toshihiro

    2016-10-01

    The water vapor transmission rate (WVTR) of a gas barrier coating is a critically important parameter for flexible organic device packaging, but its accurate measurement without mechanical stress to ultrathin films has been a significant challenge in instrumental analysis. At the current stage, no reliable results have been reported in the range of 10-6 g m-2 day-1 that is required for organic light emitting diodes (OLEDs). In this article, we describe a solution for this difficult, but important measurement, involving enhanced sensitivity by a cold trap, stabilized temperature system, pumped sealing and calibration by a standard conductance element.

  9. The Cambridge Face Tracker: Accurate, Low Cost Measurement of Head Posture Using Computer Vision and Face Recognition Software.

    Science.gov (United States)

    Thomas, Peter B M; Baltrušaitis, Tadas; Robinson, Peter; Vivian, Anthony J

    2016-09-01

    We validate a video-based method of head posture measurement. The Cambridge Face Tracker uses neural networks (constrained local neural fields) to recognize facial features in video. The relative position of these facial features is used to calculate head posture. First, we assess the accuracy of this approach against videos in three research databases where each frame is tagged with a precisely measured head posture. Second, we compare our method to a commercially available mechanical device, the Cervical Range of Motion device: four subjects each adopted 43 distinct head postures that were measured using both methods. The Cambridge Face Tracker achieved confident facial recognition in 92% of the approximately 38,000 frames of video from the three databases. The respective mean error in absolute head posture was 3.34°, 3.86°, and 2.81°, with a median error of 1.97°, 2.16°, and 1.96°. The accuracy decreased with more extreme head posture. Comparing The Cambridge Face Tracker to the Cervical Range of Motion Device gave correlation coefficients of 0.99 ( P Cambridge Face Tracker performs well under real-world conditions and within the range of normally-encountered head posture. It allows useful quantification of head posture in real time or from precaptured video. Its performance is similar to that of a clinically validated mechanical device. It has significant advantages over other approaches in that subjects do not need to wear any apparatus, and it requires only low cost, easy-to-setup consumer electronics. Noncontact assessment of head posture allows more complete clinical assessment of patients, and could benefit surgical planning in future.

  10. Impact of sample extraction on the accurate measurement of progesterone in human serum by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Ke, Yuyong; Gonthier, Renaud; Labrie, Fernand

    2017-05-01

    In the present study, the impact of the extraction solvent on the accuracy of endogenous progesterone assay in human serum has been investigated using two selective reaction monitoring (SRM) transitions (315>97 & 315>109). Higher levels of noise and more interference were observed when more polar solvents were used for extraction, thus resulting in serious bias of the measured values of progesterone in serum. This is confirmed by monitoring the ion ratio of 315>97-315>109. This issue could not be easily resolved by changes in MS/MS transitions or chromatography conditions. More bias was observed with the SRM transition 315>109 for the polar solvent extraction. Hexane and 1-chlorobutane (polarity index of 0 and 1, respectively) did provide the cleanest samples with a lower noise level in the chromatograms. Moreover, the measured values of progesterone were not changed with different SRM transitions or longer retention time in search of an improved separation. Recovery tests of progesterone have been performed with 1-chlorobutane in matrices with phosphate buffered saline (PBS) 1x, PBS 1×3% bovine serum albumin (BSA), stripped serum/H2O (1:1) and unstripped serum. The recovery (70%∼80%) consistency is observed not only at different levels but also in different matrices. The equivalent recovery between PBS 1x, PBS 1×3% BSA and unstripped serum shows that the impact of progesterone binding to serum proteins on the measurement accuracy can be avoided with this sample preparation procedure. No significant matrix effect on the determination of progesterone was observed with 1-chlorobutane. Within the range of 12.5-2000pg/mL, a good linearity is observed with R>0.99 and weighting factor 1/X. Bias and covariance efficiency of QCs are within 10%. With 1-chlorobutane as the extraction solvent, the concentration of progesterone was measured where the range for postmenopausal serum is 5.74∼91.7pg/mL, which is well below the reported concentrations of 314 pg/mL∼942pg

  11. Recombination monitor

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S. Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-02-03

    This is a brief report on LEReC recombination monitor design considerations. The recombination produced Au78+ ion rate is reviewed. Based on this two designs are discussed. One is to use the large dispersion lattice. It is shown that even with the large separation of the Au78+ beam from the Au79+ beam, the continued monitoring of the recombination is not possible. Accumulation of Au78+ ions is needed, plus collimation of the Au79+ beam. In another design, it is shown that the recombination monitor can be built based on the proposed scheme with the nominal lattice. From machine operation point of view, this design is preferable. Finally, possible studies and the alternative strategies with the basic goal of the monitor are discussed.

  12. Should clinicians use average or peak scores on a dynamic risk-assessment measure to most accurately predict inpatient aggression?

    Science.gov (United States)

    Chu, Chi Meng; Thomas, Stuart D M; Daffern, Michael; Ogloff, James R P

    2013-12-01

    Recent advancements in risk assessment have led to the development of dynamic risk-assessment measures that are predictive of inpatient aggression in the short term. However, there are several areas within this field that warrant further empirical investigation, including whether the average, maximum, or most recent risk state assessment is the most valid for predicting subsequent aggression in the medium term. This prospective study compared the predictive validity of three indices (i.e. mean score, peak score, and most recent single time-point rating) of the Dynamic Appraisal of Situational Aggression (DASA) for inpatient aggression. Daily risk ratings were completed for 60 psychiatric inpatients (from the acute wards of a forensic psychiatric hospital) for up to 6 months; a total of 1054 DASA ratings were obtained. Results showed that mean and peak scores on the DASA were better predictors of interpersonal violence, verbal threat, and any inpatient aggression than the DASA single time-point most recent ratings. Overall, the results support the use of the prior week's mean and peak scores to aid the prediction of inpatient aggression within inpatient forensic psychiatric settings in the short to medium term. These results also have practical implications for clinicians considering risk-management strategies and the scoring of clinically-relevant items on risk-assessment measures. © 2012 The Authors; International Journal of Mental Health Nursing © 2012 Australian College of Mental Health Nurses Inc.

  13. Is a standalone inertial measurement unit accurate and precise enough for quantification of movement symmetry in the horse?

    Science.gov (United States)

    Brighton, Charlotte; Olsen, Emil; Pfau, Thilo

    2015-01-01

    Standalone 'low-cost' inertial measurement units (IMUs) could facilitate large-scale studies into establishing minimal important differences (MID) for orthopaedic deficits (lameness) in horses. We investigated accuracy and limits of agreement (LoA) after correction of magnitude-dependent differences of a standalone 6 degree-of-freedom IMU compared with an established IMU-based gait analysis system (MTx) in six horses for two anatomical landmarks (sacrum and sternum). Established symmetry measures were calculated from vertical displacement: symmetry index (SI), difference between minima (MinDiff) and difference between maxima (MaxDiff). For the sacrum, LoA were ± 0.095 for SI, ± 6.6 mm for MinDiff and ± 4.3 mm for MaxDiff. For the sternum, LoA values were ± 0.088 for SI, ± 5.0 mm for MinDiff and ± 4.2 mm for MaxDiff. Compared with reference data from mildly lame horses, SI values indicate sufficient precision, whereas MinDiff and MaxDiff values are less favourable. Future studies should investigate specific calibration and processing algorithms further improving standalone IMU performance.

  14. ‘Dose-to-Mother’ Deuterium Oxide Dilution Technique: An Accurate Strategy to Measure Vitamin A Intake in Breastfed Infants

    Directory of Open Access Journals (Sweden)

    Veronica Lopez-Teros

    2017-02-01

    Full Text Available In Mexico, infants (0–2 years old show the highest prevalence of vitamin A deficiency (VAD, measured by serum retinol concentrations. Thus, we consider that low vitamin A (VA intake through breast milk (BM combined with poor weaning practices are the main factors that contribute to VAD in this group. We combined the assessment of VA status in lactating women using BM retinol and a stable isotope ‘dose-to-mother’ technique to measure BM production in women from urban and agricultural areas. Infants’ mean BM intake was 758 ± 185 mL, and no difference was observed between both areas (p = 0.067. Mean BM retinol concentration was 1.09 μmol/L, which was significantly lower for the agricultural area (p = 0.028. Based on BM retinol concentration, 57% of women were VAD; although this prevalence fell to 16% when based on fat content. Regardless of the VA biomarker used here, infants from the urban and agricultural areas cover only 66% and 49% of their dietary adequate intake from BM, respectively (p = 0.054. Our data indicate that VAD is still a public health concern in Mexico. Adopting both methods to assess VA transfer from the mother to the breastfed child offers an innovative approach towards the nutritional assessment of vulnerable groups.

  15. Accurate kinematic measurement at interfaces between dissimilar materials using conforming finite-element-based digital image correlation

    KAUST Repository

    Tao, Ran

    2016-02-11

    Digital image correlation (DIC) is now an extensively applied full-field measurement technique with subpixel accuracy. A systematic drawback of this technique, however, is the smoothening of the kinematic field (e.g., displacement and strains) across interfaces between dissimilar materials, where the deformation gradient is known to be large. This can become an issue when a high level of accuracy is needed, for example, in the interfacial region of composites or joints. In this work, we described the application of global conforming finite-element-based DIC technique to obtain precise kinematic fields at interfaces between dissimilar materials. Speckle images from both numerical and actual experiments processed by the described global DIC technique better captured sharp strain gradient at the interface than local subset-based DIC. © 2016 Elsevier Ltd. All rights reserved.

  16. Development of an accurate pH measurement methodology for the pore fluids of low pH cementitious materials

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, M. C.; Garcia Calvo, J. L. [The Spanish National Research Council (CSIC), Madrid (Spain); Walker, C. [Japan Atomic Energy Agency (JAEA), Ibaraki (Japan)] [and others

    2012-08-15

    The main objective of this project has been the development of an agreed set of protocols for the pH measurement of the pore fluid of a low pH cementitious material. Three protocols have been developed (Chapter 2), a reference method, based on pore fluid expression (PFE), and two routine methods with and without filtering, based on Ex Situ Leaching (ESL) procedures. Templates have been designed on which to record details of the pH measurement for the reference (PFE) method (Appendix C) and the routine (ESL) methods without and with filtering (Appendix D). Preliminary protocols were based on a broad review of the literature (Appendix A) and refined through a series of test experiments of the more critical parameters (Appendix B). After definition of the preliminary protocols, two phases of interlaboratory tests were performed. The first phase (Chapter 3) used the same low pH cement paste and enabled the nine participating laboratories to use, become familiar with and to identify any problems/uncertainties in the preliminary protocols. The reported pH values were subjected to a statistical analysis of the (within laboratory) repeatability and (between-laboratory) reproducibility and so provided a reliability test of the preliminary protocols. The second phase (Chapter 4) of interlaboratory tests used four different candidate low pH cementitious materials in the same nine laboratories, which allowed testing, validation and comparison of the reported pH values, which were obtained using the final protocols for the reference (PFE) and routine (ESL) methods by statistical analysis. The proposed final protocols (Chapter 2) have resulted in the reported pH values having low deviation and high reproducibility and repeatability. This will allow confidence in the pH value when selecting a candidate low pH cementitious material to be used in the engineered component of a high-level nuclear waste repository.

  17. Charge exchange recombination in X-ray spectra of He-like argon measured at the tokamak TEXTOR

    Energy Technology Data Exchange (ETDEWEB)

    Schlummer, Tobias

    2014-06-16

    Charge exchange recombination between ions and atomic hydrogen is an important atomic process in magnetically confined fusion plasmas. Besides radiative cooling of the plasma edge, charge exchange causes modifications of the ionization balance and the population densities of excited ion states. The central goal of this work is to investigate the influence of charge exchange on X-ray spectra measured at the tokamak TEXTOR. A new 2D X-ray spectrometer developed for future use at the stellarator W7-X was recently installed at TEXTOR. The spectrometer is optimized for measuring the K{sub α}-spectrum of He-like argon (1s2l - 1s{sup 2}) at wavelengths close to 4 Aa. K{sub α}-spectroscopy on He-like impurity ions is an established diagnostic for electron and ion temperature measurements in fusion plasmas. Still, up to now the observed intensity ratios of the K{sub α}-lines and their associated satellites are not fully understood. They show significant deviations from the predictions made by basic corona models. In the past charge exchange with the neutral particle background and radial impurity transport have been discussed as likely explanations. Yet a detailed description of the experimental spectra still has not been achieved. To reconstruct the 2D K{sub α}-spectra measured at TEXTOR the radial argon ion distribution is modeled using an impurity transport code. The model accounts for charge exchange and transport on basis of given radial profiles of the neutral particle density n{sub 0}(r) and the diffusion coefficient D {sub perpendicular} {sub to} (r). The theoretical spectrum is then constructed based on the processes relevant for line emission. Within an iterative procedure n{sub 0}(r) and D {sub perpendicular} {sub to} (r) are varied until consistency between the theoretical and the experimental spectra is achieved. It is shown that the 2D K{sub α}-spectra allow a clear distinction of charge exchange and transport effects, ensuring unique solutions for n

  18. Tumor volume in subcutaneous mouse xenografts measured by microCT is more accurate and reproducible than determined by 18F-FDG-microPET or external caliper

    DEFF Research Database (Denmark)

    Jensen, Mette Munk; Jørgensen, Jesper Tranekjaer; Binderup, Tina

    2008-01-01

    and reproducible measures of tumor size in mice compared with caliper measurements. Furthermore, we evaluated the accuracy of tumor volume determined from 18F-fluorodeoxyglucose (18F-FDG) PET. METHODS: Subcutaneously implanted human breast adenocarcinoma cells in NMRI nude mice served as tumor model. Tumor volume......BACKGROUND: In animal studies tumor size is used to assess responses to anticancer therapy. Current standard for volumetric measurement of xenografted tumors is by external caliper, a method often affected by error. The aim of the present study was to evaluate if microCT gives more accurate...... (n = 20) was determined in vivo by external caliper, microCT and 18F-FDG-PET and subsequently reference volume was determined ex vivo. Intra-observer reproducibility of the microCT and caliper methods were determined by acquiring 10 repeated volume measurements. Volumes of a group of tumors (n = 10...

  19. How many measurements are needed to estimate accurate daily and annual soil respiration fluxes? Analysis using data from a temperate rainforest

    Science.gov (United States)

    Perez-Quezada, Jorge F.; Brito, Carla E.; Cabezas, Julián; Galleguillos, Mauricio; Fuentes, Juan P.; Bown, Horacio E.; Franck, Nicolás

    2016-12-01

    Making accurate estimations of daily and annual Rs fluxes is key for understanding the carbon cycle process and projecting effects of climate change. In this study we used high-frequency sampling (24 measurements per day) of Rs in a temperate rainforest during 1 year, with the objective of answering the questions of when and how often measurements should be made to obtain accurate estimations of daily and annual Rs. We randomly selected data to simulate samplings of 1, 2, 4 or 6 measurements per day (distributed either during the whole day or only during daytime), combined with 4, 6, 12, 26 or 52 measurements per year. Based on the comparison of partial-data series with the full-data series, we estimated the performance of different partial sampling strategies based on bias, precision and accuracy. In the case of annual Rs estimation, we compared the performance of interpolation vs. using non-linear modelling based on soil temperature. The results show that, under our study conditions, sampling twice a day was enough to accurately estimate daily Rs (RMSE < 10 % of average daily flux), even if both measurements were done during daytime. The highest reduction in RMSE for the estimation of annual Rs was achieved when increasing from four to six measurements per year, but reductions were still relevant when further increasing the frequency of sampling. We found that increasing the number of field campaigns was more effective than increasing the number of measurements per day, provided a minimum of two measurements per day was used. Including night-time measurements significantly reduced the bias and was relevant in reducing the number of field campaigns when a lower level of acceptable error (RMSE < 5 %) was established. Using non-linear modelling instead of linear interpolation did improve the estimation of annual Rs, but not as expected. In conclusion, given that most of the studies of Rs use manual sampling techniques and apply only one measurement per day, we

  20. Characterising molecules for fundamental physics: an accurate spectroscopic model of methyltrioxorhenium derived from new infrared and millimetre-wave measurements.

    Science.gov (United States)

    Asselin, Pierre; Berger, Yann; Huet, Thérèse R; Margulès, Laurent; Motiyenko, Roman; Hendricks, Richard J; Tarbutt, Michael R; Tokunaga, Sean K; Darquié, Benoît

    2017-02-08

    Precise spectroscopic analysis of polyatomic molecules enables many striking advances in physical chemistry and fundamental physics. We use several new high-resolution spectroscopic devices to improve our understanding of the rotational and rovibrational structure of methyltrioxorhenium (MTO), the achiral parent of a family of large oxorhenium compounds that are ideal candidate species for a planned measurement of parity violation in chiral molecules. Using millimetre-wave and infrared spectroscopy in a pulsed supersonic jet, a cryogenic buffer gas cell, and room temperature absorption cells, we probe the ground state and the Re[double bond, length as m-dash]O antisymmetric and symmetric stretching excited states of both CH3187ReO3 and CH3185ReO3 isotopologues in the gas phase with unprecedented precision. By extending the rotational spectra to the 150-300 GHz range, we characterize the ground state rotational and hyperfine structure up to J = 43 and K = 41, resulting in refinements to the rotational, quartic and hyperfine parameters, and the determination of sextic parameters and a centrifugal distortion correction to the quadrupolar hyperfine constant. We obtain rovibrational data for temperatures between 6 and 300 K in the 970-1015 cm-1 range, at resolutions down to 8 MHz and accuracies of 30 MHz. We use these data to determine more precise excited-state rotational, Coriolis and quartic parameters, as well as the ground-state centrifugal distortion parameter DK of the 187Re isotopologue. We also account for hyperfine structure in the rovibrational transitions and hence determine the upper state rhenium atom quadrupole coupling constant eQq'.

  1. Simple and accurate measurement of carbamazepine in surface water by use of porous membrane-protected micro-solid-phase extraction coupled with isotope dilution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Teo, Hui Ling [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Wong, Lingkai [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Liu, Qinde, E-mail: liu_qinde@hsa.gov.sg [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Teo, Tang Lin; Lee, Tong Kooi [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Lee, Hian Kee, E-mail: chmleehk@nus.edu.sg [Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore)

    2016-03-17

    To achieve fast and accurate analysis of carbamazepine in surface water, we developed a novel porous membrane-protected micro-solid-phase extraction (μ-SPE) method, followed by liquid chromatography-isotope dilution tandem mass spectrometry (LC-IDMS/MS) analysis. The μ-SPE device (∼0.8 × 1 cm) was fabricated by heat-sealing edges of a polypropylene membrane sheet to devise a bag enclosing the sorbent. The analytes (both carbamazepine and isotope-labelled carbamazepine) were first extracted by μ-SPE device in the sample (10 mL) via agitation, then desorbed in an organic solvent (1 mL) via ultrasonication. Several parameters such as organic solvent for pre-conditioning of μ-SPE device, amount of sorbent, adsorption time, and desorption solvent and time were investigated to optimize the μ-SPE efficiency. The optimized method has limits of detection and quantitation estimated to be 0.5 ng L{sup −1} and 1.6 ng L{sup −1}, respectively. Surface water samples spiked with different amounts of carbamazepine (close to 20, 500, and 1600 ng L{sup −1}, respectively) were analysed for the validation of method precision and accuracy. Good precision was obtained as demonstrated by relative standard deviations of 0.7% for the samples with concentrations of 500 and 1600 ng kg{sup −1}, and 5.8% for the sample with concentration of 20 ng kg{sup −1}. Good accuracy was also demonstrated by the relative recoveries in the range of 96.7%–103.5% for all samples with uncertainties of 1.1%–5.4%. Owing to the same chemical properties of carbamazepine and isotope-labelled carbamazepine, the isotope ratio in the μ-SPE procedure was accurately controlled. The use of μ-SPE coupled with IDMS analysis significantly facilitated the fast and accurate measurement of carbamazepine in surface water. - Highlights: • μ-SPE coupled with IDMS for the measurement of carbamazepine. • The method is the first report of coupling μ-SPE with IDMS. • μ-SPE is fast, time

  2. Ion recombination correction in carbon ion beams.

    Science.gov (United States)

    Rossomme, S; Hopfgartner, J; Lee, N D; Delor, A; Thomas, R A S; Romano, F; Fukumura, A; Vynckier, S; Palmans, H

    2016-07-01

    In this work, ion recombination is studied as a function of energy and depth in carbon ion beams. Measurements were performed in three different passively scattered carbon ion beams with energies of 62 MeV/n, 135 MeV/n, and 290 MeV/n using various types of plane-parallel ionization chambers. Experimental results were compared with two analytical models for initial recombination. One model is generally used for photon beams and the other model, developed by Jaffé, takes into account the ionization density along the ion track. An investigation was carried out to ascertain the effect on the ion recombination correction with varying ionization chamber orientation with respect to the direction of the ion tracks. The variation of the ion recombination correction factors as a function of depth was studied for a Markus ionization chamber in the 62 MeV/n nonmodulated carbon ion beam. This variation can be related to the depth distribution of linear energy transfer. Results show that the theory for photon beams is not applicable to carbon ion beams. On the other hand, by optimizing the value of the ionization density and the initial mean-square radius, good agreement is found between Jaffé's theory and the experimental results. As predicted by Jaffé's theory, the results confirm that ion recombination corrections strongly decrease with an increasing angle between the ion tracks and the electric field lines. For the Markus ionization chamber, the variation of the ion recombination correction factor with depth was modeled adequately by a sigmoid function, which is approximately constant in the plateau and strongly increasing in the Bragg peak region to values of up to 1.06. Except in the distal edge region, all experimental results are accurately described by Jaffé's theory. Experimental results confirm that ion recombination in the investigated carbon ion beams is dominated by initial recombination. Ion recombination corrections are found to be significant and cannot be

  3. A high etendue spectrometer suitable for core charge eXchange recombination spectroscopy on ITER

    NARCIS (Netherlands)

    Jaspers, R.J.E.; Scheffer, M.; Kappatou, A.; Valk, N.C.J. van der; Durkut, M.; Snijders, B.; Marchuk, O.; Biel, W.; Pokol, G.I.; Erdei, G.; Zoletnik, S.; Dunai, D.

    2012-01-01

    A feasibility study for the use of core charge exchange recombination spectroscopy on ITER has shown that accurate measurements on the helium ash require a spectrometer with a high etendue of 1mm 2sr to comply with the measurement requirements [S. Tugarinov, Rev. Sci. Instrum. 74, 2075

  4. Intraoperative bone and bone marrow sampling: a simple method for accurate measurement of uptake of radiopharmaceuticals in bone and bone marrow

    Energy Technology Data Exchange (ETDEWEB)

    Oyen, W.J.G.; Buijs, W.C.A.M.; Kampen, A. van; Koenders, E.B.; Claessens, R.A.M.J.; Corstens, F.H.M. (University Hospital, Nijmegen (Netherlands))

    1993-02-01

    Accurate estimation of bone marrow uptake of radiopharmaceuticals is of crucial importance for accurate whole body dosimetry. In this study, a method for obtaining normal bone marrow and bone during routine surgery without inconvenience to volunteers is suggested and compared to an indirect method. In five volunteers (group 1), 4 MBq [sup 111]In-labelled human polyclonal IgG ([sup 111]In-IgG) was administered 48h before placement of a total hip prosthesis. After resection of the femoral head and neck, bone marrow was aspirated from the medullary space with a biopsy needle. In five patients, suspected of having infectious disease (group 2), bone marrow uptake was calculated according to a well-accepted method using regions of interest over the lumbar spine, 48h after injection of 75 MBq [sup 111]In-IgG. Bone marrow uptake in group 1 (4.5 [+-]1.3%D kg[sup -1]) was significantly lower than that in group 2 (8.5 [+-] 2.1%D kg[sup -1]) (P<0.01). Blood and plasma activity did not differ significantly for both groups. This method provides a system for directly and accurately measuring uptake and retention in normal bone marrow and bone of all radiopharmaceuticals at various time points. It is a safe and simple procedure without any discomfort to the patient. Since small amounts of activity are sufficient, the radiation dose to the patient is low. (author).

  5. The body adiposity index (hip circumference ÷ height(1.5)) is not a more accurate measure of adiposity than is BMI, waist circumference, or hip circumference.

    Science.gov (United States)

    Freedman, David S; Thornton, John C; Pi-Sunyer, F Xavier; Heymsfield, Steven B; Wang, Jack; Pierson, Richard N; Blanck, Heidi M; Gallagher, Dympna

    2012-12-01

    Based on cross-sectional analyses, it was suggested that hip circumference divided by height(1.5) -18 (the body adiposity index (BAI)), could directly estimate percent body fat without the need for further correction for sex or age. We compared the prediction of percent body fat, as assessed by dual-energy X-ray absorptiometry (PBF(DXA)), by BAI, BMI, and circumference (waist and hip) measurements among 1,151 adults who had a total body scan by DXA and circumference measurements from 1993 through 2005. After accounting for sex, we found that PBF(DXA) was related similarly to BAI, BMI, waist circumference, and hip circumference. In general, BAI underestimated PBF(DXA) among men (2.5%) and overestimated PBF(DXA) among women (4%), but the magnitudes of these biases varied with the level of body fatness. The addition of covariates and quadratic terms for the body size measures in regression models substantially improved the prediction of PBF(DXA), but none of the models based on BAI could more accurately predict PBF(DXA) than could those based on BMI or circumferences. We conclude that the use of BAI as an indicator of adiposity is likely to produce biased estimates of percent body fat, with the errors varying by sex and level of body fatness. Although regression models that account for the nonlinear association, as well as the influence of sex, age, and race, can yield more accurate estimates of PBF(DXA), estimates based on BAI are not more accurate than those based on BMI, waist circumference, or hip circumference.

  6. Accurate measurement of heteronuclear dipolar couplings by phase-alternating R-symmetry (PARS) sequences in magic angle spinning NMR spectroscopy

    Science.gov (United States)

    Hou, Guangjin; Lu, Xingyu; Vega, Alexander J.; Polenova, Tatyana

    2014-09-01

    We report a Phase-Alternating R-Symmetry (PARS) dipolar recoupling scheme for accurate measurement of heteronuclear 1H-X (X = 13C, 15N, 31P, etc.) dipolar couplings in MAS NMR experiments. It is an improvement of conventional C- and R-symmetry type DIPSHIFT experiments where, in addition to the dipolar interaction, the 1H CSA interaction persists and thereby introduces considerable errors in the dipolar measurements. In PARS, phase-shifted RN symmetry pulse blocks applied on the 1H spins combined with π pulses applied on the X spins at the end of each RN block efficiently suppress the effect from 1H chemical shift anisotropy, while keeping the 1H-X dipolar couplings intact. Another advantage over conventional DIPSHIFT experiments, which require the signal to be detected in the form of a reduced-intensity Hahn echo, is that the series of π pulses refocuses the X chemical shift and avoids the necessity of echo formation. PARS permits determination of accurate dipolar couplings in a single experiment; it is suitable for a wide range of MAS conditions including both slow and fast MAS frequencies; and it assures dipolar truncation from the remote protons. The performance of PARS is tested on two model systems, [15N]-N-acetyl-valine and [U-13C,15N]-N-formyl-Met-Leu-Phe tripeptide. The application of PARS for site-resolved measurement of accurate 1H-15N dipolar couplings in the context of 3D experiments is presented on U-13C,15N-enriched dynein light chain protein LC8.

  7. Accurate measurement of heteronuclear dipolar couplings by phase-alternating R-symmetry (PARS) sequences in magic angle spinning NMR spectroscopy.

    Science.gov (United States)

    Hou, Guangjin; Lu, Xingyu; Vega, Alexander J; Polenova, Tatyana

    2014-09-14

    We report a Phase-Alternating R-Symmetry (PARS) dipolar recoupling scheme for accurate measurement of heteronuclear (1)H-X (X = (13)C, (15)N, (31)P, etc.) dipolar couplings in MAS NMR experiments. It is an improvement of conventional C- and R-symmetry type DIPSHIFT experiments where, in addition to the dipolar interaction, the (1)H CSA interaction persists and thereby introduces considerable errors in the dipolar measurements. In PARS, phase-shifted RN symmetry pulse blocks applied on the (1)H spins combined with π pulses applied on the X spins at the end of each RN block efficiently suppress the effect from (1)H chemical shift anisotropy, while keeping the (1)H-X dipolar couplings intact. Another advantage over conventional DIPSHIFT experiments, which require the signal to be detected in the form of a reduced-intensity Hahn echo, is that the series of π pulses refocuses the X chemical shift and avoids the necessity of echo formation. PARS permits determination of accurate dipolar couplings in a single experiment; it is suitable for a wide range of MAS conditions including both slow and fast MAS frequencies; and it assures dipolar truncation from the remote protons. The performance of PARS is tested on two model systems, [(15)N]-N-acetyl-valine and [U-(13)C,(15)N]-N-formyl-Met-Leu-Phe tripeptide. The application of PARS for site-resolved measurement of accurate (1)H-(15)N dipolar couplings in the context of 3D experiments is presented on U-(13)C,(15)N-enriched dynein light chain protein LC8.

  8. Accurate measurement of heteronuclear dipolar couplings by phase-alternating R-symmetry (PARS) sequences in magic angle spinning NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Guangjin, E-mail: hou@udel.edu, E-mail: tpolenov@udel.edu; Lu, Xingyu, E-mail: luxingyu@udel.edu, E-mail: lexvega@comcast.net; Vega, Alexander J., E-mail: luxingyu@udel.edu, E-mail: lexvega@comcast.net; Polenova, Tatyana, E-mail: hou@udel.edu, E-mail: tpolenov@udel.edu [Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA and Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, Pennsylvania 15261 (United States)

    2014-09-14

    We report a Phase-Alternating R-Symmetry (PARS) dipolar recoupling scheme for accurate measurement of heteronuclear {sup 1}H-X (X = {sup 13}C, {sup 15}N, {sup 31}P, etc.) dipolar couplings in MAS NMR experiments. It is an improvement of conventional C- and R-symmetry type DIPSHIFT experiments where, in addition to the dipolar interaction, the {sup 1}H CSA interaction persists and thereby introduces considerable errors in the dipolar measurements. In PARS, phase-shifted RN symmetry pulse blocks applied on the {sup 1}H spins combined with π pulses applied on the X spins at the end of each RN block efficiently suppress the effect from {sup 1}H chemical shift anisotropy, while keeping the {sup 1}H-X dipolar couplings intact. Another advantage over conventional DIPSHIFT experiments, which require the signal to be detected in the form of a reduced-intensity Hahn echo, is that the series of π pulses refocuses the X chemical shift and avoids the necessity of echo formation. PARS permits determination of accurate dipolar couplings in a single experiment; it is suitable for a wide range of MAS conditions including both slow and fast MAS frequencies; and it assures dipolar truncation from the remote protons. The performance of PARS is tested on two model systems, [{sup 15}N]-N-acetyl-valine and [U-{sup 13}C,{sup 15}N]-N-formyl-Met-Leu-Phe tripeptide. The application of PARS for site-resolved measurement of accurate {sup 1}H-{sup 15}N dipolar couplings in the context of 3D experiments is presented on U-{sup 13}C,{sup 15}N-enriched dynein light chain protein LC8.

  9. Electromagnetic calorimeter and accurate measurement with the ATLAS detector of the LHC collider; Calorimetrie electromagnetique et mesures de precision avec le detecteur ATLAS aupres du collisionneur LHC

    Energy Technology Data Exchange (ETDEWEB)

    Pralavorio, P

    2007-06-15

    The main purpose of the ATLAS experiment is the understanding of the underlying mechanisms that drive the breaking of the electro-weak symmetry through the discovery of Higgs bosons. An important element to achieve this aim was the design of an electromagnetic calorimeter able to investigate the decay channels: H {yields} {gamma}{gamma} and H {yields} 4e. The high performance of the calorimeter will allow us to get a better accuracy on the measuring values of W and top masses which is essential to indirectly constrain the mass of the Higgs. In the same way, accurate measurements of top and W properties during the decays of top and tWb vertex will be necessary to question the standard model and to see beyond. The author has been working for 9 years in the ATLAS project, he has been involved in the design, construction, qualification and testing phases of the electromagnetic calorimeter of ATLAS. This document is a detailed presentation of the calorimeter, of its qualification and of its expectations when LHC is operating. This document is organized into 4 chapters: 1) assets and weaknesses of the standard model, 2) the ATLAS experiment, 3) the electromagnetic calorimeter, and 4) accurate measurements with ATLAS. This document presented before an academic board will allow its author to manage research works and particularly to tutor thesis students. (A.C.)

  10. Atomic spectroscopy and highly accurate measurement: determination of fundamental constants; Spectroscopie atomique et mesures de grande precision: determination de constantes fonfamentales

    Energy Technology Data Exchange (ETDEWEB)

    Schwob, C

    2006-12-15

    This document reviews the theoretical and experimental achievements of the author concerning highly accurate atomic spectroscopy applied for the determination of fundamental constants. A pure optical frequency measurement of the 2S-12D 2-photon transitions in atomic hydrogen and deuterium has been performed. The experimental setting-up is described as well as the data analysis. Optimized values for the Rydberg constant and Lamb shifts have been deduced (R = 109737.31568516 (84) cm{sup -1}). An experiment devoted to the determination of the fine structure constant with an aimed relative uncertainty of 10{sup -9} began in 1999. This experiment is based on the fact that Bloch oscillations in a frequency chirped optical lattice are a powerful tool to transfer coherently many photon momenta to the atoms. We have used this method to measure accurately the ratio h/m(Rb). The measured value of the fine structure constant is {alpha}{sub -1} = 137.03599884 (91) with a relative uncertainty of 6.7*10{sup -9}. The future and perspectives of this experiment are presented. This document presented before an academic board will allow his author to manage research work and particularly to tutor thesis students. (A.C.)

  11. Accurate measurements of fission-fragment yields in 234,235,236,238U(γ,f with the SOFIA set-up

    Directory of Open Access Journals (Sweden)

    Chatillon A.

    2016-01-01

    Full Text Available SOFIA (Studies On Fission with Aladin is a new experimental set-up dedicated to accurate measurement of fission-fragments isotopic yields. It is located at GSI, the only place to use inverse kinematics at relativistic energies in order to study the (γ,f electromagnetic-induced fission. The SOFIA set-up is a large-acceptance magnetic spectrometer, which allows to fully identify both fission fragments in coincidence on the whole fission-fragment range. This paper will report on fission yields obtained in 234,235,236,238U(γ,f reactions.

  12. Accurate measurements of fission-fragment yields in 234,235,236,238U(γ,f) with the SOFIA set-up

    Science.gov (United States)

    Chatillon, A.; Taïeb, J.; Martin, J.-F.; Pellereau, E.; Boutoux, G.; Gorbinet, T.; Grente, L.; Bélier, G.; Laurent, B.; Alvarez-Pol, H.; Ayyad, Y.; Benlliure, J.; Caamaño, M.; Audouin, L.; Casarejos, E.; Cortina-Gil, D.; Farget, F.; Fernández-Domínguez, B.; Heinz, A.; Jurado, B.; Kelić-Heil, A.; Kurz, N.; Lindberg, S.; Löher, B.; Nociforo, C.; Paradela, C.; Pietri, S.; Ramos, D.; Rodriguez-Sanchez, J.-L.; Rodrìguez-Tajes, C.; Rossi, D.; Schmidt, K.-H.; Simon, H.; Tassan-Got, L.; Törnqvist, H.; Vargas, J.; Voss, B.; Weick, H.; Yan, Y.

    2016-03-01

    SOFIA (Studies On Fission with Aladin) is a new experimental set-up dedicated to accurate measurement of fission-fragments isotopic yields. It is located at GSI, the only place to use inverse kinematics at relativistic energies in order to study the (γ,f) electromagnetic-induced fission. The SOFIA set-up is a large-acceptance magnetic spectrometer, which allows to fully identify both fission fragments in coincidence on the whole fission-fragment range. This paper will report on fission yields obtained in 234,235,236,238U(γ,f) reactions.

  13. Do pregnant women accurately report sleep time? A comparison between self-reported and objective measures of sleep duration in pregnancy among a sample of urban mothers.

    Science.gov (United States)

    Herring, Sharon J; Foster, Gary D; Pien, Grace W; Massa, Katherine; Nelson, Deborah B; Gehrman, Philip R; Davey, Adam

    2013-12-01

    Survey questions are commonly used to assess sleep duration because of their low cost and convenience. Responses to these questions correlate moderately with objectively measured sleep duration in nonpregnant individuals, but little is known about the validity of self-reported sleep measures in pregnancy. The aim of the present study was to determine the extent to which self-reported gestational sleep duration assessed by questionnaire predicted objectively measured gestational sleep duration via actigraphy. We analyzed data from 80 mothers enrolled in an ancillary study of Project BABIES, a prospective cohort study of urban, pregnant women. Sleep measurements were collected in midpregnancy and included 7 days of wrist actigraphy, a sleep log, and survey questions about sleep time adapted from the Pittsburgh Sleep Quality Index. Mean measured gestational sleep duration derived from actigraphy was 6.87 h [standard deviation (SD) 0.87], and questionnaire-assessed nocturnal sleep time averaged 7.29 h (SD 1.84). While the difference between measures did not reach statistical significance (p = 0.07 for paired samples t test), over half (62 %) of participants reported a habitual average nightly sleep time that differed more than 1 h from their average actigraphically measured sleep duration (39 % overestimated by more than an hour; 23 % underestimated by more than an hour). There was no correlation between measures (r = 0.007; 95 % confidence interval -0.21, 0.23). Questionnaire-derived reports of usual sleep hours do not reflect objectively measured sleep time in urban, pregnant women. Actigraphy is preferable to accurately assess gestational sleep duration.

  14. Time-accurate CFD conjugate analysis of transient measurements of the heat-transfer coefficient in a channel with pin fins

    Directory of Open Access Journals (Sweden)

    Tom I-P. Shih

    2013-03-01

    Full Text Available Heat-transfer coefficients (HTC on surfaces exposed to convection environments are often measured by transient techniques such as thermochromic liquid crystal (TLC or infrared thermography. In these techniques, the surface temperature is measured as a function of time, and that measurement is used with the exact solution for unsteady, zero-dimensional (0-D or one-dimensional (1-D heat conduction into a solid to calculate the local HTC. When using the 0-D or 1-D exact solutions, the transient techniques assume the HTC and the free-stream or bulk temperature characterizing the convection environment to be constants in addition to assuming the conduction into the solid to be 0-D or 1-D. In this study, computational fluid dynamics (CFD conjugate analyses were performed to examine the errors that might be invoked by these assumptions for a problem, where the free-stream/bulk temperature and the heat-transfer coefficient vary appreciably along the surface and where conduction into the solid may not be 0-D or 1-D. The problem selected to assess these errors is flow and heat transfer in a channel lined with a staggered array of pin fins. This conjugate study uses three-dimensional (3-D unsteady Reynolds-averaged Navier–Stokes (RANS closed by the shear-stress transport (SST turbulence model for the gas phase (wall functions not used and the Fourier law for the solid phase. The errors in the transient techniques are assessed by comparing the HTC predicted by the time-accurate conjugate CFD with those predicted by the 0-D and 1-D exact solutions, where the surface temperatures needed by the exact solutions are taken from the time-accurate conjugate CFD solution. Results obtained show that the use of the 1-D exact solution for the semi-infinite wall to give reasonably accurate “transient” HTC (less than 5% relative error. Transient techniques that use the 0-D exact solution for the pin fins were found to produce large errors (up to 160% relative error

  15. Dual-energy X-ray absorptiometry (DXA) can accurately and nondestructively measure the body composition of small, free-living rodents.

    Science.gov (United States)

    Stevenson, Kalb T; van Tets, Ian G

    2008-01-01

    Dual-energy x-ray absorptiometry (DXA) is a nondestructive technique that can potentially measure specific components of whole-body composition in free-living and lab-raised animals. Our aim was to test the ability of DXA to measure the composition of a common arvicoline rodent, the northern red-backed vole (Clethrionomys rutilus). We used a DXA apparatus to obtain measurements of fat mass (FM), lean mass (LM),bone mineral content, bone mineral density, and fat-free mass(FFM) in carcasses of free-living and lab-raised voles. We then used chemical carcass analysis to derive predictive algorithms for actual values of FM, total body water, total protein, total mineral, LM, and FFM. Unexplained error in the equations for all voles grouped collectively ranged from R(2) = 0.82 to R(2) = 0.98. The DXA FM measurement had the highest coefficient of variation, and it was higher for free-living voles than for lab-raised voles. However, FM can be determined by difference with excellent precision by using the FFM equation (R(2) = 0.98). We also derived corrective terms for passive integrated transponder-tagged animals. Thus, DXA is a nonlethal, nondestructive tool capable of precisely and accurately measuring many specific parameters of whole-body composition in small free-living and lab-raised rodents.

  16. Knowing what the brain is seeing in three dimensions: A novel, noninvasive, sensitive, accurate, and low-noise technique for measuring ocular torsion.

    Science.gov (United States)

    Otero-Millan, Jorge; Roberts, Dale C; Lasker, Adrian; Zee, David S; Kheradmand, Amir

    2015-01-01

    Torsional eye movements are rotations of the eye around the line of sight. Measuring torsion is essential to understanding how the brain controls eye position and how it creates a veridical perception of object orientation in three dimensions. Torsion is also important for diagnosis of many vestibular, neurological, and ophthalmological disorders. Currently, there are multiple devices and methods that produce reliable measurements of horizontal and vertical eye movements. Measuring torsion, however, noninvasively and reliably has been a longstanding challenge, with previous methods lacking real-time capabilities or suffering from intrusive artifacts. We propose a novel method for measuring eye movements in three dimensions using modern computer vision software (OpenCV) and concepts of iris recognition. To measure torsion, we use template matching of the entire iris and automatically account for occlusion of the iris and pupil by the eyelids. The current setup operates binocularly at 100 Hz with noise <0.1° and is accurate within 20° of gaze to the left, to the right, and up and 10° of gaze down. This new method can be widely applicable and fill a gap in many scientific and clinical disciplines.

  17. Heparin removal by ecteola-cellulose pre-treatment enables the use of plasma samples for accurate measurement of anti-Yellow fever virus neutralizing antibodies.

    Science.gov (United States)

    Campi-Azevedo, Ana Carolina; Peruhype-Magalhães, Vanessa; Coelho-Dos-Reis, Jordana Grazziela; Costa-Pereira, Christiane; Yamamura, Anna Yoshida; Lima, Sheila Maria Barbosa de; Simões, Marisol; Campos, Fernanda Magalhães Freire; de Castro Zacche Tonini, Aline; Lemos, Elenice Moreira; Brum, Ricardo Cristiano; de Noronha, Tatiana Guimarães; Freire, Marcos Silva; Maia, Maria de Lourdes Sousa; Camacho, Luiz Antônio Bastos; Rios, Maria; Chancey, Caren; Romano, Alessandro; Domingues, Carla Magda; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis

    2017-09-01

    Technological innovations in vaccinology have recently contributed to bring about novel insights for the vaccine-induced immune response. While the current protocols that use peripheral blood samples may provide abundant data, a range of distinct components of whole blood samples are required and the different anticoagulant systems employed may impair some properties of the biological sample and interfere with functional assays. Although the interference of heparin in functional assays for viral neutralizing antibodies such as the functional plaque-reduction neutralization test (PRNT), considered the gold-standard method to assess and monitor the protective immunity induced by the Yellow fever virus (YFV) vaccine, has been well characterized, the development of pre-analytical treatments is still required for the establishment of optimized protocols. The present study intended to optimize and evaluate the performance of pre-analytical treatment of heparin-collected blood samples with ecteola-cellulose (ECT) to provide accurate measurement of anti-YFV neutralizing antibodies, by PRNT. The study was designed in three steps, including: I. Problem statement; II. Pre-analytical steps; III. Analytical steps. Data confirmed the interference of heparin on PRNT reactivity in a dose-responsive fashion. Distinct sets of conditions for ECT pre-treatment were tested to optimize the heparin removal. The optimized protocol was pre-validated to determine the effectiveness of heparin plasma:ECT treatment to restore the PRNT titers as compared to serum samples. The validation and comparative performance was carried out by using a large range of serum vs heparin plasma:ECT 1:2 paired samples obtained from unvaccinated and 17DD-YFV primary vaccinated subjects. Altogether, the findings support the use of heparin plasma:ECT samples for accurate measurement of anti-YFV neutralizing antibodies. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Accurate Laser Measurements of the Water Vapor Self-Continuum Absorption in Four Near Infrared Atmospheric Windows. a Test of the MT_CKD Model.

    Science.gov (United States)

    Campargue, Alain; Kassi, Samir; Mondelain, Didier; Romanini, Daniele; Lechevallier, Loïc; Vasilchenko, Semyon

    2017-06-01

    The semi empirical MT_CKD model of the absorption continuum of water vapor is widely used in atmospheric radiative transfer codes of the atmosphere of Earth and exoplanets but lacks of experimental validation in the atmospheric windows. Recent laboratory measurements by Fourier transform Spectroscopy have led to self-continuum cross-sections much larger than the MT_CKD values in the near infrared transparency windows. In the present work, we report on accurate water vapor absorption continuum measurements by Cavity Ring Down Spectroscopy (CRDS) and Optical-Feedback-Cavity Enhanced Laser Spectroscopy (OF-CEAS) at selected spectral points of the transparency windows centered around 4.0, 2.1 and 1.25 μm. The temperature dependence of the absorption continuum at 4.38 μm and 3.32 μm is measured in the 23-39 °C range. The self-continuum water vapor absorption is derived either from the baseline variation of spectra recorded for a series of pressure values over a small spectral interval or from baseline monitoring at fixed laser frequency, during pressure ramps. In order to avoid possible bias approaching the water saturation pressure, the maximum pressure value was limited to about 16 Torr, corresponding to a 75% humidity rate. After subtraction of the local water monomer lines contribution, self-continuum cross-sections, C_{S}, were determined with a few % accuracy from the pressure squared dependence of the spectra base line level. Together with our previous CRDS and OF-CEAS measurements in the 2.1 and 1.6 μm windows, the derived water vapor self-continuum provides a unique set of water vapor self-continuum cross-sections for a test of the MT_CKD model in four transparency windows. Although showing some important deviations of the absolute values (up to a factor of 4 at the center of the 2.1 μm window), our accurate measurements validate the overall frequency dependence of the MT_CKD2.8 model.

  19. S(3) HMBC: Spin-State-Selective HMBC for accurate measurement of homonuclear coupling constants. Application to strychnine yielding thirteen hitherto unreported J(HH).

    Science.gov (United States)

    Kjaerulff, Louise; Benie, Andrew J; Hoeck, Casper; Gotfredsen, Charlotte H; Sørensen, Ole W

    2016-02-01

    A novel method, Spin-State-Selective (S(3)) HMBC, for accurate measurement of homonuclear coupling constants is introduced. As characteristic for S(3) techniques, S(3) HMBC yields independent subspectra corresponding to particular passive spin states and thus allows determination of coupling constants between detected spins and homonuclear coupling partners along with relative signs. In the presented S(3) HMBC experiment, spin-state selection occurs via large one-bond coupling constants ensuring high editing accuracy and unequivocal sign determination of the homonuclear long-range relative to the associated one-bond coupling constant. The sensitivity of the new experiment is comparable to that of regular edited HMBC and the accuracy of the J/RDC measurement is as usual for E.COSY and S(3)-type experiments independent of the size of the homonuclear coupling constant of interest. The merits of the method are demonstrated by an application to strychnine where thirteen J(HH) coupling constants not previously reported could be measured. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Accurate Region-of-Interest Recovery Improves the Measurement of the Cell Migration Rate in the In Vitro Wound Healing Assay.

    Science.gov (United States)

    Bedoya, Cesar; Cardona, Andrés; Galeano, July; Cortés-Mancera, Fabián; Sandoz, Patrick; Zarzycki, Artur

    2017-12-01

    The wound healing assay is widely used for the quantitative analysis of highly regulated cellular events. In this essay, a wound is voluntarily produced on a confluent cell monolayer, and then the rate of wound reduction (WR) is characterized by processing images of the same regions of interest (ROIs) recorded at different time intervals. In this method, sharp-image ROI recovery is indispensable to compensate for displacements of the cell cultures due either to the exploration of multiple sites of the same culture or to transfers from the microscope stage to a cell incubator. ROI recovery is usually done manually and, despite a low-magnification microscope objective is generally used (10x), repositioning imperfections constitute a major source of errors detrimental to the WR measurement accuracy. We address this ROI recovery issue by using pseudoperiodic patterns fixed onto the cell culture dishes, allowing the easy localization of ROIs and the accurate quantification of positioning errors. The method is applied to a tumor-derived cell line, and the WR rates are measured by means of two different image processing software. Sharp ROI recovery based on the proposed method is found to improve significantly the accuracy of the WR measurement and the positioning under the microscope.

  1. Experimental evaluation of water vapour cross-sensitivity for accurate eddy covariance measurement of CO2 flux using open-path CO2/H2O gas analysers

    Directory of Open Access Journals (Sweden)

    Fumiyoshi Kondo

    2014-10-01

    Full Text Available Non-dispersive infrared CO2/H2O gas analysers produce erroneous CO2 outputs when CO2 is measured in humid air, unless a correction for water vapour cross-sensitivity is applied. Spectroscopic cross-sensitivities arising from direct absorption interference and from the pressure broadening effect are significant in CO2 flux measurements by the eddy covariance technique using open-path gas analysers over the ocean, as opposed to land-surface measurements, where CO2 fluxes are orders of magnitude larger. In this study, a widely used analyser with manufacturer-determined correction coefficients for both cross-sensitivities was tested by laboratory experiments. Our results showed that the correction coefficient for direct absorption interference was not optimised to calculate CO2 flux accurately, and that the correction coefficient for the pressure broadening caused overestimation of the CO2 mixing ratio flux in the same direction as the water vapour flux. Overestimations of open-path eddy covariance measurements of upward CO2 fluxes in previous ocean observations probably resulted from inaccuracies in both of these correction coefficients. We also found that slight changes in spectroscopic cross-sensitivities due to contamination of the analyser's optical windows by sea salt caused a low bias in CO2 outputs with increasing H2O; however, this contamination effect was not always observed in repeated tests under different contamination conditions. We suggest that previously proposed methods for correcting the effect of optical window contamination is of limited value and that measurement of small CO2 fluxes by the open-path eddy covariance technique over the ocean should be performed after confirming the spectroscopic cross-sensitivity and ensuring that the optical windows are as clean as possible.

  2. Regulation of Meiotic Recombination

    Energy Technology Data Exchange (ETDEWEB)

    Gregory p. Copenhaver

    2011-11-09

    for assaying recombination using tetrad analysis in a higher eukaryotic system (6). This system enabled the measurement of the frequency and distribution of recombination events at a genome wide level in wild type Arabidopsis (7), construction of genetic linkage maps which include positions for each centromere (8), and modeling of the strength and pattern of interference (9). This proposal extends the use of tetrad analysis in Arabidopsis by using it as the basis for assessing the phenotypes of mutants in genes important for recombination and the regulation of crossover interference and performing a novel genetic screen. In addition to broadening our knowledge of a classic genetic problem - the regulation of recombination by crossover interference - this proposal also provides broader impact by: generating pedagogical tools for use in hands-on classroom experience with genetics, building interdisciplinary collegial partnerships, and creating a platform for participation by junior scientists from underrepresented groups. There are three specific aims: (1) Isolate mutants in Arabidopsis MUS81 homologs using T-DNA and TILLING (2) Characterize recombination levels and interference in mus81 mutants (3) Execute a novel genetic screen, based on tetrad analysis, for genes that regulate meiotic recombination

  3. A simple and inclusive method to determine the habit plane in transmission electron microscope based on accurate measurement of foil thickness

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Dong, E-mail: d.qiu@uq.edu.au; Zhang, Mingxing

    2014-08-15

    A simple and inclusive method is proposed for accurate determination of the habit plane between bicrystals in transmission electron microscope. Whilst this method can be regarded as a variant of surface trace analysis, the major innovation lies in the improved accuracy and efficiency of foil thickness measurement, which involves a simple tilt of the thin foil about a permanent tilting axis of the specimen holder, rather than cumbersome tilt about the surface trace of the habit plane. Experimental study has been done to validate this proposed method in determining the habit plane between lamellar α{sub 2} plates and γ matrix in a Ti–Al–Nb alloy. Both high accuracy (± 1°) and high precision (± 1°) have been achieved by using the new method. The source of the experimental errors as well as the applicability of this method is discussed. Some tips to minimise the experimental errors are also suggested. - Highlights: • An improved algorithm is formulated to measure the foil thickness. • Habit plane can be determined with a single tilt holder based on the new algorithm. • Better accuracy and precision within ± 1° are achievable using the proposed method. • The data for multi-facet determination can be collected simultaneously.

  4. Web-based accurate measurements of carotid lumen diameter and stenosis severity: An ultrasound-based clinical tool for stroke risk assessment during multicenter clinical trials.

    Science.gov (United States)

    Saba, Luca; Banchhor, Sumit K; Londhe, Narendra D; Araki, Tadashi; Laird, John R; Gupta, Ajay; Nicolaides, Andrew; Suri, Jasjit S

    2017-12-01

    This pilot study presents a completely automated, novel, smart, cloud-based, point-of-care system for (a) carotid lumen diameter (LD); (b) stenosis severity index (SSI) and (c) total lumen area (TLA) measurement using B-mode ultrasound. The proposed system was (i) validated against manual reading taken by the Neurologist and (ii) benchmarked against the commercially available system. One hundred patients (73 M/27 F, mean age: 68 ± 11 years), institutional review board approved, written informed consent, consisted of left/right common carotid artery (200 ultrasound scans) were acquired using a 7.5-MHz linear transducer. The measured mean LD for left and right carotids were (in mm): (i) for proposed system (6.49 ± 1.77, 6.66 ± 1.70); and (ii) for manual (6.29 ± 1.79, 6.45 ± 1.63), respectively and coefficient of correlation between cloud-based automated against manual were 0.98 (P 1.0. Four statistical tests such as: Two-tailed z-test, Mann-Whitney test, Kolmogorov-Smirnov (KS) and one-way ANOVA were performed to demonstrate consistency and reliability. The proposed system is reliable, accurate, fast, completely automated, anytime-anywhere solution for multi-center clinical trials and routine vascular screening. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Snow thickness profiling on Antarctic sea ice with GPR—Rapid and accurate measurements with the potential to upscale needles to a haystack

    Science.gov (United States)

    Pfaffhuber, Andreas A.; Lieser, Jan L.; Haas, Christian

    2017-08-01

    Snow thickness on sea ice is a largely undersampled parameter yet of importance for the sea ice mass balance and for satellite-based sea ice thickness estimates and thus our general understanding of global ice volume change. Traditional direct thickness measurements with meter sticks can provide accurate but only spot information, referred to as "needles" due to their pinpoint focus and information, while airborne and satellite remote sensing snow products, referred to as "the haystack," have large uncertainties due to their scale. We demonstrate the remarkable accuracy and applicability of ground-penetrating radar (GPR) snow thickness measurements by comparing them with in situ meter stick data from two field campaigns to Antarctica in late winter/early spring. The efficiency and millimeter-to-centimeter accuracy of GPR enables practitioners to acquire extensive, semiregional data with the potential to upscale needles to the haystack and to potentially calibrate satellite remote sensing products that we confirm to derive roughly 30% of the in situ thickness. We find the radar wave propagation velocity in snow to be rather constant (± 6%), encouraging regional snow thickness surveys. Snow thinner than 10 cm is under the detection limit with the off-the-shelf GPR setup utilized in our study.

  6. Identification based on quantitative measurements and aroma recombination of the character impact odorants in a Bavarian Pilsner-type beer.

    Science.gov (United States)

    Fritsch, Helge T; Schieberle, Peter

    2005-09-21

    Application of aroma extract dilution analysis on the volatiles isolated from a Bavarian Pilsner-type beer revealed 40 odor-active constituents in the flavor dilution (FD) factor range of 16-2048, among which ethyl octanoate, (E)-beta-damascenone, 2- and 3-methylbutanoic acid, and 4-hydroxy-2,5-dimethyl-3(2H)-furanone showed the highest FD factor of 2048. After quantitation of the 26 odorants showing FD factors > or =128 by stable isotope dilution analysis and determination of their odor thresholds in water, odor acitivity values (OAVs) were calculated. The results indicated ethanol, (E)-beta-damascenone, (R)-linalool, acetaldehyde, and ethyl butanoate with the highest OAVs, followed by ethyl 2-methylpropanoate and ethyl 4-methylpentanoate, which was previously unknown in beer. Finally, the overall aroma of the beer could be mimicked for the first time by recombining 22 reference odorants in the same concentrations as they occurred in the beer using ethanol/water as the matrix.

  7. A comparison of assays for accurate copy number measurement of the low-affinity Fc gamma receptor genes FCGR3A and FCGR3B.

    Directory of Open Access Journals (Sweden)

    Umi Shakina Haridan

    Full Text Available The FCGR3 locus encoding the low affinity activating receptor FcγRIII, plays a vital role in immunity triggered by cellular effector and regulatory functions. Copy number of the genes FCGR3A and FCGR3B has previously been reported to affect susceptibility to several autoimmune diseases and chronic inflammatory conditions. However, such genetic association studies often yield inconsistent results; hence require assays that are robust with low error rate. We investigated the accuracy and efficiency in estimating FCGR3 CNV by comparing Sequenom MassARRAY and paralogue ratio test-restriction enzyme digest variant ratio (PRT-REDVR. In addition, since many genetic association studies of FCGR3B CNV were carried out using real-time quantitative PCR, we have also included the evaluation of that method's performance in estimating the multi-allelic CNV of FCGR3B. The qPCR assay exhibited a considerably broader distribution of signal intensity, potentially introducing error in estimation of copy number and higher false positive rates. Both Sequenom and PRT-REDVR showed lesser systematic bias, but Sequenom skewed towards copy number normal (CN = 2. The discrepancy between Sequenom and PRT-REDVR might be attributed either to batch effects noise in individual measurements. Our study suggests that PRT-REDVR is more robust and accurate in genotyping the CNV of FCGR3, but highlights the needs of multiple independent assays for extensive validation when performing a genetic association study with multi-allelic CNVs.

  8. Signal processing of diurnal and semidiurnal variations in radon and atmospheric pressure: A new tool for accurate in situ measurement of soil gas velocity, pressure gradient, and tortuosity

    Science.gov (United States)

    Pinault, Jean-Louis; Baubron, Jean-Claude

    1997-08-01

    Signal processing of diurnal and semidiurnal variations of both atmospheric pressure and radon concentration in soil gases is shown to be useful for estimating soil gas transport parameters. The two daily-cycle peaks at 12- and 24-hour periods in the Power Spectral Density (PSD) of atmospheric pressure seem to be present everywhere on Earth's surface, and it is the effect of these regular pressure variations on the radon concentration in soil gases that makes it possible to determine three soil gas transport parameters which can be used to estimate real gas velocity; i.e. tortuosity τ, the ratio k/n between intrinsic permeability and effective porosity (that part of porosity involved in gas transport), and the pressure gradient α. The parameters k and n can be determined independently if the gas flux at the surface is measured at the same time. The method is robust, representative, and accurate: since it allows reliable estimation of transport parameters, it can provide relevant information about the depth of the radon source and the time it takes for information to reach the surface when radon bursts occur at depth. Radon is an appropriate soil gas tracer because it exists in all soils. Moreover, the measurement of radon concentration requires only passive sensors that do not hamper the rising gas column. Gas flux data obtained in Andalusia, Spain, in connection with mineral exploration are processed as examples. Determining the complete set of transport parameters helps in the interpretation of recorded radon outbursts, which are found to be correlated with regional seismic activity.

  9. Any condomless anal intercourse is no longer an accurate measure of HIV sexual risk behaviour in gay and other men who have sex with men

    Directory of Open Access Journals (Sweden)

    Fengyi eJin

    2015-02-01

    Full Text Available Background: Condomless anal intercourse (CLAI has long been recognised as the primary mode of sexual transmission of HIV in gay and other men who have sex with men (MSM. A variety of measures of CLAI have been commonly used in behavioural surveillance for HIV risk and to forecast trends in HIV infection. However, gay and other MSM’s sexual practices changed as the understanding of disease and treatment options advance. In the present paper, we argue that summary measures such as any CLAI do not accurately measure HIV sexual risk behaviour. Methods: Participants were 1,427 HIV-negative men from the Health in Men cohort study run from 2001 to 2007 in Sydney, Australia, with six-monthly interviews. At each interview, detailed quantitative data on the number of episodes of insertive and receptive CLAI in the last six months were collected, separated by partner type (regular vs. casual and partners’ HIV status (negative, positive, and HIV status unknown.Results: A total of 228,064 episodes of CLAI were reported during the study period with a mean of 44 episodes per year per participant (median: 14. The great majority of CLAI episodes were with a regular partner (92.6%, most of them with HIV-negative regular partners (84.8%. Participants were more likely to engage in insertive CLAI with casual than with regular partners (66.7% vs. 55.3% of all acts of CLAI with each partner type, p<0.001. Men were more likely to report CLAI in the receptive position with HIV-negative and HIV status unknown partners than with HIV-positive partners (p<0.001 for both regular and casual partners. Conclusion: Gay and other MSM engaging in CLAI demonstrate clear patterns of HIV risk reduction behaviour. As HIV prevention enters the era of antiretroviral-based biomedical approach, using all forms of CLAI indiscriminately as a measure of HIV behavioural risk is not helpful in understanding the current drivers of HIV transmission in the community.

  10. Cosmological constraints from the CFHTLenS shear measurements using a new, accurate, and flexible way of predicting non-linear mass clustering

    Science.gov (United States)

    Angulo, Raul E.; Hilbert, Stefan

    2015-03-01

    We explore the cosmological constraints from cosmic shear using a new way of modelling the non-linear matter correlation functions. The new formalism extends the method of Angulo & White, which manipulates outputs of N-body simulations to represent the 3D non-linear mass distribution in different cosmological scenarios. We show that predictions from our approach for shear two-point correlations at 1-300 arcmin separations are accurate at the ˜10 per cent level, even for extreme changes in cosmology. For moderate changes, with target cosmologies similar to that preferred by analyses of recent Planck data, the accuracy is close to ˜5 per cent. We combine this approach with a Monte Carlo Markov chain sampler to explore constraints on a Λ cold dark matter model from the shear correlation functions measured in the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). We obtain constraints on the parameter combination σ8(Ωm/0.27)0.6 = 0.801 ± 0.028. Combined with results from cosmic microwave background data, we obtain marginalized constraints on σ8 = 0.81 ± 0.01 and Ωm = 0.29 ± 0.01. These results are statistically compatible with previous analyses, which supports the validity of our approach. We discuss the advantages of our method and the potential it offers, including a path to model in detail (i) the effects of baryons, (ii) high-order shear correlation functions, and (iii) galaxy-galaxy lensing, among others, in future high-precision cosmological analyses.

  11. NEW ACCURATE MEASUREMENT OF {sup 36}ArH{sup +} AND {sup 38}ArH{sup +} RO-VIBRATIONAL TRANSITIONS BY HIGH RESOLUTION IR ABSORPTION SPECTROSCOPY

    Energy Technology Data Exchange (ETDEWEB)

    Cueto, M.; Herrero, V. J.; Tanarro, I.; Doménech, J. L. [Molecular Physics Department, Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, E-28006 Madrid (Spain); Cernicharo, J. [Department of Astrophysics, CAB. INTA-CSIC. Crta Torrejón-Ajalvir Km 4, E-28850 Torrejón de Ardoz, Madrid (Spain); Barlow, M. J.; Swinyard, B. M., E-mail: jl.domenech@csic.es [Department of Physics and Astronomy, University College London. Gower Street, London WC1E 6BT (United Kingdom)

    2014-03-01

    The protonated argon ion, {sup 36}ArH{sup +}, was recently identified in the Crab Nebula from Herschel spectra. Given the atmospheric opacity at the frequency of its J = 1-0 and J = 2-1 rotational transitions (617.5 and 1234.6 GHz, respectively), and the current lack of appropriate space observatories after the recent end of the Herschel mission, future studies on this molecule will rely on mid-infrared observations. We report on accurate wavenumber measurements of {sup 36}ArH{sup +} and {sup 38}ArH{sup +} rotation-vibration transitions in the v = 1-0 band in the range 4.1-3.7 μm (2450-2715 cm{sup –1}). The wavenumbers of the R(0) transitions of the v = 1-0 band are 2612.50135 ± 0.00033 and 2610.70177 ± 0.00042 cm{sup –1} (±3σ) for {sup 36}ArH{sup +} and {sup 38}ArH{sup +}, respectively. The calculated opacity for a gas thermalized at a temperature of 100 K and with a linewidth of 1 km s{sup –1} of the R(0) line is 1.6 × 10{sup –15} × N({sup 36}ArH{sup +}). For column densities of {sup 36}ArH{sup +} larger than 1 × 10{sup 13} cm{sup –2}, significant absorption by the R(0) line can be expected against bright mid-IR sources.

  12. Accurate measurements of vadose zone fluxes using automated equilibrium tension plate lysimeters: A synopsis of results from the Spydia research facility, New Zealand.

    Science.gov (United States)

    Wöhling, Thomas; Barkle, Greg; Stenger, Roland; Moorhead, Brian; Wall, Aaron; Clague, Juliet

    2014-05-01

    Automated equilibrium tension plate lysimeters (AETLs) are arguably the most accurate method to measure unsaturated water and contaminant fluxes below the root zone at the scale of up to 1 m². The AETL technique utilizes a porous sintered stainless-steel plate to provide a comparatively large sampling area with a continuously controlled vacuum that is in "equilibrium" with the surrounding vadose zone matric pressure to ensure measured fluxes represent those under undisturbed conditions. This novel lysimeter technique was used at an intensive research site for investigations of contaminant pathways from the land surface to the groundwater on a sheep and beef farm under pastoral land use in the Tutaeuaua subcatchment, New Zealand. The Spydia research facility was constructed in 2005 and was fully operational between 2006 and 2011. Extending from a central access caisson, 15 separately controlled AETLs with 0.2 m² surface area were installed at five depths between 0.4 m and 5.1 m into the undisturbed volcanic vadose zone materials. The unique setup of the facility ensured minimum interference of the experimental equipment and external factors with the measurements. Over the period of more than five years, a comprehensive data set was collected at each of the 15 AETL locations which comprises of time series of soil water flux, pressure head, volumetric water contents, and soil temperature. The soil water was regularly analysed for EC, pH, dissolved carbon, various nitrogen compounds (including nitrate, ammonia, and organic N), phosphorus, bromide, chloride, sulphate, silica, and a range of other major ions, as well as for various metals. Climate data was measured directly at the site (rainfall) and a climate station at 500m distance. The shallow groundwater was sampled at three different depths directly from the Spydia caisson and at various observation wells surrounding the facility. Two tracer experiments were conducted at the site in 2009 and 2010. In the 2009

  13. BIOACCESSIBILITY TESTS ACCURATELY ESTIMATE ...

    Science.gov (United States)

    Hazards of soil-borne Pb to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, we measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison with blood Pb concentrations in quail fed a Pb acetate reference diet. Diets containing soil from five Pb-contaminated Superfund sites had relative bioavailabilities from 33%-63%, with a mean of about 50%. Treatment of two of the soils with P significantly reduced the bioavailability of Pb. The bioaccessibility of the Pb in the test soils was then measured in six in vitro tests and regressed on bioavailability. They were: the “Relative Bioavailability Leaching Procedure” (RBALP) at pH 1.5, the same test conducted at pH 2.5, the “Ohio State University In vitro Gastrointestinal” method (OSU IVG), the “Urban Soil Bioaccessible Lead Test”, the modified “Physiologically Based Extraction Test” and the “Waterfowl Physiologically Based Extraction Test.” All regressions had positive slopes. Based on criteria of slope and coefficient of determination, the RBALP pH 2.5 and OSU IVG tests performed very well. Speciation by X-ray absorption spectroscopy demonstrated that, on average, most of the Pb in the sampled soils was sorbed to minerals (30%), bound to organic matter 24%, or present as Pb sulfate 18%. Ad

  14. Specific In Vivo Labeling of Tyrosinated α-Tubulin and Measurement of Microtubule Dynamics Using a GFP Tagged, Cytoplasmically Expressed Recombinant Antibody

    Science.gov (United States)

    Cassimeris, Lynne; Guglielmi, Laurence; Denis, Vincent; Larroque, Christian; Martineau, Pierre

    2013-01-01

    GFP-tagged proteins are used extensively as biosensors for protein localization and function, but the GFP moiety can interfere with protein properties. An alternative is to indirectly label proteins using intracellular recombinant antibodies (scFvs), but most antibody fragments are insoluble in the reducing environment of the cytosol. From a synthetic hyperstable human scFv library we isolated an anti-tubulin scFv, 2G4, which is soluble in mammalian cells when expressed as a GFP-fusion protein. Here we report the use of this GFP-tagged scFv to label microtubules in fixed and living cells. We found that 2G4-GFP localized uniformly along microtubules and did not disrupt binding of EB1, a protein that binds microtubule ends and serves as a platform for binding by a complex of proteins regulating MT polymerization. TOGp and CLIP-170 also bound microtubule ends in cells expressing 2G4-GFP. Microtubule dynamic instability, measured by tracking 2G4-GFP labeled microtubules, was nearly identical to that measured in cells expressing GFP-α-tubulin. Fluorescence recovery after photobleaching demonstrated that 2G4-GFP turns over rapidly on microtubules, similar to the turnover rates of fluorescently tagged microtubule-associated proteins. These data indicate that 2G4-GFP binds relatively weakly to microtubules, and this conclusion was confirmed in vitro. Purified 2G4 partially co-pelleted with microtubules, but a significant fraction remained in the soluble fraction, while a second anti-tubulin scFv, 2F12, was almost completely co-pelleted with microtubules. In cells, 2G4-GFP localized to most microtubules, but did not co-localize with those composed of detyrosinated α-tubulin, a post-translational modification associated with non-dynamic, more stable microtubules. Immunoblots probing bacterially expressed tubulins confirmed that 2G4 recognized α-tubulin and required tubulin’s C-terminal tyrosine residue for binding. Thus, a recombinant antibody with weak affinity for its

  15. Evaluation of a multiple-cycle, recombinant virus, growth competition assay that uses flow cytometry to measure replication efficiency of human immunodeficiency virus type 1 in cell culture.

    Science.gov (United States)

    Dykes, Carrie; Wang, Jiong; Jin, Xia; Planelles, Vicente; An, Dong Sung; Tallo, Amanda; Huang, Yangxin; Wu, Hulin; Demeter, Lisa M

    2006-06-01

    Human immunodeficiency virus type 1 (HIV-1) replication efficiency or fitness, as measured in cell culture, has been postulated to correlate with clinical outcome of HIV infection, although this is still controversial. One limitation is the lack of high-throughput assays that can measure replication efficiency over multiple rounds of replication. We have developed a multiple-cycle growth competition assay to measure HIV-1 replication efficiency that uses flow cytometry to determine the relative proportions of test and reference viruses, each of which expresses a different reporter gene in place of nef. The reporter genes are expressed on the surface of infected cells and are detected by commercially available fluorescence-labeled antibodies. This method is less labor-intensive than those that require isolation and amplification of nucleic acids. The two reporter gene products are detected with similar specificity and sensitivity, and the proportion of infected cells in culture correlates with the amount of viral p24 antigen produced in the culture supernatant. HIV replication efficiencies of six different drug-resistant site-directed mutants were reproducibly quantified and were similar to those obtained with a growth competition assay in which the relative proportion of each variant was measured by sequence analysis, indicating that recombination between the pol and reporter genes was negligible. This assay also reproducibly quantified the relative fitness conferred by protease and reverse transcriptase sequences containing multiple drug resistance mutations, amplified from patient plasma. This flow cytometry-based growth competition assay offers advantages over current assays for HIV replication efficiency and should prove useful for the evaluation of patient samples in clinical trials.

  16. REPLACR-mutagenesis, a one-step method for site-directed mutagenesis by recombineering

    National Research Council Canada - National Science Library

    Trehan, Ashutosh; Kiełbus, Michał; Czapinski, Jakub; Stepulak, Andrzej; Huhtaniemi, Ilpo; Rivero-Müller, Adolfo

    2016-01-01

    .... Most of the current methods for mutagenesis involve multiple step procedures. One of the most accurate methods for genetically altering DNA is recombineering, which uses bacteria expressing viral recombination proteins...

  17. A New CCI ECV Release (v2.0) to Accurately Measure the Sea Level Change from space (1993-2015)

    Science.gov (United States)

    Legeais, Jean-Francois; Benveniste, Jérôme

    2017-04-01

    Accurate monitoring of the sea level is required to better understand its variability and changes. Sea level is one of the Essential Climate Variables (ECV) selected in the frame of the ESA Climate Change Initiative (CCI) program. It aims at providing a long-term homogeneous and accurate sea level record. The needs and feedback of the climate research community have been collected so that the development of the products is adapted to the users. A first version of the sea level ECV product has been generated during phase I of the project (2011-2013). Within phase II (2014-2016), the 15 partner consortium has prepared the production of a new reprocessed homogeneous and accurate altimeter sea level record which is now available (see http://www.esa-sealevel-cci.org/products ). New level 2 altimeter standards developed and tested within the project as well as external contributions have been identified, processed and evaluated by comparison with a reference for different altimeter missions (TOPEX/Poseidon, Jason-1 & 2, ERS-1 & 2, Envisat, GFO, SARAL/AltiKa and CryoSat-2). The main evolutions are associated with the wet troposphere correction (based on the GPD+ algorithm including inter calibration with respect to external sensors) but also to the orbit solutions (POE-E and GFZ15), the ERA-Interim based atmospheric corrections and the FES2014 ocean tide model. A new pole tide solution is used and anomalies are referenced to the MSS DTU15. The presentation will focus on the main achievements of the ESA CCI Sea Level project and on the description of the new SL_cci ECV release covering 1993-2015. The major steps required to produce the reprocessed 23 year climate time series will be described. The impacts of the selected level 2 altimeter standards on the SL_cci ECV have been assessed on different spatial scales (global, regional, mesoscale) and temporal scales (long-term, inter-annual, periodic signals). A significant improvement is observed compared to the current v1

  18. Electricity meters - accurate and free of wear. A low power microcontroller for high power measurement; Elektrizitaetszaehler - verschleissfrei und genau. Ein Low-Power-Mikrocontroller misst High Power

    Energy Technology Data Exchange (ETDEWEB)

    Schauer, S. [Texas Instruments (Germany). Bereich System Design

    2002-04-30

    Electronic energy meters started to replace electromechanical Ferraris meters a few years ago. They are free of mechanical wear and are more compact and more accurate. Today, electronic meters are gaining ground in private households, whether as single local meters, pre-payment meters or integrated remote control and metering systems. The MSP430 microcontroller family is particularly well suited owing to its low power consumption. [German] Seit einigen Jahren ersetzen in der Industrie elektronische Energiezaehler zunehmend die elektromechanischen Ferraris-Zaehler. Die Gruende dafuer liegen in der mechanischen Verschleissfreiheit und der geringeren Baugroesse bei gleichzeitig hoeherer Genauigkeit. Mittlerweile halten die elektronischen Zaehler sogar immer mehr in privaten Haushalten Einzug, ob als lokales Einzelgeraet oder als Pre-Payment-Zaehler bis hin zu vernetzten Fernsteuer- und Fernabfragesystemen. Ihre niedrige Leistungsaufnahme praedestiniert die Mikrocontrollerfamilie MSP430 geradezu fuer diese Anwendungen. (orig.)

  19. A single gas chromatograph for accurate atmospheric mixing ratio measurements of CO2, CH4, N2O, SF6 and CO

    NARCIS (Netherlands)

    van der Laan, S.; Neubert, R. E. M.; Meijer, H. A. J.; Simpson, W.R.

    2009-01-01

    We present an adapted gas chromatograph capable of measuring simultaneously and semi-continuously the atmospheric mixing ratios of the greenhouse gases CO2, CH4, N2O and SF6 and the trace gas CO with high precision and long-term stability. The novelty of our design is that all species are measured

  20. Therapeutic Recombinant Monoclonal Antibodies

    Science.gov (United States)

    Bakhtiar, Ray

    2012-01-01

    During the last two decades, the rapid growth of biotechnology-derived techniques has led to a myriad of therapeutic recombinant monoclonal antibodies with significant clinical benefits. Recombinant monoclonal antibodies can be obtained from a number of natural sources such as animal cell cultures using recombinant DNA engineering. In contrast to…

  1. The Hall effect in the organic conductor TTF–TCNQ: choice of geometry for accurate measurements of a highly anisotropic system

    DEFF Research Database (Denmark)

    Tafra, E; Čulo, M; Basletić, M

    2012-01-01

    We have measured the Hall effect on recently synthesized single crystals of the quasi-one-dimensional organic conductor TTF–TCNQ (tetrathiafulvalene–tetracyanoquinodimethane), a well known charge transfer complex that has two kinds of conductive stacks: the donor (TTF) and the acceptor (TCNQ...... Hall effect measurements. Our results show, contrary to past belief, that the Hall coefficient does not depend on the geometry of measurements and that the Hall coefficient value is approximately zero in the high temperature region (T > 150 K), implying that there is no dominance of either the TTF...... or the TCNQ chain. At lower temperatures our measurements clearly prove that all three phase transitions of TTF–TCNQ could be identified from Hall effect measurements....

  2. Recombination pattern reanalysis of some HIV-1 circulating recombination forms suggest the necessity and difficulty of revision.

    Directory of Open Access Journals (Sweden)

    Lei Jia

    Full Text Available Recombination is one of the major mechanisms underlying the generation of HIV-1 variability. Currently 61 circulating recombinant forms of HIV-1 have been identified. With the development of recombination detection techniques and accumulation of HIV-1 reference stains, more accurate mosaic structures of circulating recombinant forms (CRFs, like CRF04 and CRF06, have undergone repeated analysis and upgrades. Such revisions may also be necessary for other CRFs. Unlike previous studies, whose results are based primarily on a single recombination detection program, the current study was based on multiple recombination analysis, which may have produced more impartial results.Representative references of 3 categories of intersubtype recombinants were selected, including BC recombinants (CRF07 and CRF08, BG recombinants (CRF23 and CRF24, and BF recombinants (CRF38 and CRF44. They were reanalyzed in detail using both the jumping profile hidden Markov model and RDP3.The results indicate that revisions and upgrades are very necessary and the entire re-analysis suggested 2 types of revision: (i length of inserted fragments; and (ii number of inserted fragments. The reanalysis also indicated that determination of small regions of about 200 bases or fewer should be performed with more caution.Results indicated that the involvement of multiple recombination detection programs is very necessary. Additionally, results suggested two major challenges, one involving the difficulty of accurately determining the locations of breakpoints and the second involving identification of small regions of about 200 bases or fewer with greater caution. Both indicate the complexity of HIV-1 recombination. The resolution would depend critically on development of a recombination analysis algorithm, accumulation of HIV-1 stains, and a higher sequencing quality. With the changes in recombination pattern, phylogenetic relationships of some CRFs may also change. All these results may

  3. A single gas chromatograph for accurate atmospheric mixing ratio measurements of CO2, CH4, N2O, SF6 and CO

    Directory of Open Access Journals (Sweden)

    H. A. J. Meijer

    2009-09-01

    Full Text Available We present an adapted gas chromatograph capable of measuring simultaneously and semi-continuously the atmospheric mixing ratios of the greenhouse gases CO2, CH4, N2O and SF6 and the trace gas CO with high precision and long-term stability. The novelty of our design is that all species are measured with only one device, making it a very cost-efficient system. No time lags are introduced between the measured mixing ratios. The system is designed to operate fully autonomously which makes it ideal for measurements at remote and unmanned stations. Only a small amount of sample air is needed, which makes this system also highly suitable for flask air measurements. In principle, only two reference cylinders are needed for daily operation and only one calibration per year against international WMO standards is sufficient to obtain high measurement precision and accuracy. The system described in this paper is in use since May 2006 at our atmospheric measurement site Lutjewad near Groningen, The Netherlands at 6°21´ E, 53°24´N, 1 m a.s.l. Results show the long-term stability of the system. Observed measurement precisions at our remote research station Lutjewad were: ±0.04 ppm for CO2, ±0.8 ppb for CH4, ±0.8 ppb for CO, ±0.3 ppb for N2O, and ±0.1 ppt for SF6. The ambient mixing ratios of all measured species as observed at station Lutjewad for the period of May 2007 to August 2008 are presented as well.

  4. Dissociative Recombination of Complex Ions

    Science.gov (United States)

    Mitchell, J. Brian A.

    1999-10-01

    The FALP-MS apparatus at the University of Rennes allows the measurement of rate coefficients for the recombination of molecular ions to be made (at 300K) even though several ions may be present in the afterglow. The recombination of a number of hydrocarbon ions derived from alkane ( Lehfaoui et al. J. Chem. Phys. 106, 5406, 1997.), alkene ( Rebrion-Rowe et al. J. Chem. Phys. 108, 7185, 1998.) and aromatic (Rebrion-Rowe et al. (Submitted to J. Chem. Phys.)) parent molecules has been studied. Despite the wide range of complexity of these compounds, the measured recombination rates are remarkably similar having values in the range of 4-10-7 cm^3.s-1. Plans are being laid for a new version of this apparatus that will allow pre-prepared ions to be injected into the inert buffer gas flow. This will allow reactive ions to be studied as well as halogen containing ions whose recombination rates would normally be masked by electron attachment to their parent gases in a conventional flowing afterglow apparatus. A high temperature modification to the CRESU supersonic flow apparatus (J.L. Le Garrec et al. J. Chem. Phys. 107, 54, 1997.) in our laboratory will allow electron attachment to radicals to be studied by means of the mass spectrometric detection of products, Langmuir probe measurement of the electron density in the flow and Laser Induced Fluorescent identification of the radical species. Such measurements are needed for the modeling of semiconductor processing plasmas.

  5. Accurate Fourier transform infrared (FT-IR) spectroscopy measurements of nitrogen dioxide (NO2) and nitric acid (HNO3) calibrated with synthetic spectra.

    Science.gov (United States)

    Flores, Edgar; Viallon, Joële; Moussay, Philippe; Wielgosz, Robert Ian

    2013-10-01

    A novel method for determining the accuracy of laboratory-based measurements of nitrogen dioxide (NO2) and nitric acid (HNO3) mole fractions using Fourier transform infrared (FT-IR) spectroscopy 1 cm(-1) resolution instruments calibrated with synthetic spectra has been developed. The traceability of these measurement results is to the reference line strength data contained within the high-resolution transmission molecular absorption (HITRAN) database. Incorporating a proper estimate of the uncertainty of this data into the measurement results will ensure that the SI traceable values are encompassed within the uncertainty of the measurement results. The major contributors to the uncertainties of the results are, in descending order of importance, the uncertainty in the line strength values (HITRAN 2004), the uncertainty attributed to the generation of reference spectra (including knowledge of the optical path length of the FT-IR gas cell), and temperature measurements of the gas. The stability of the FT-IR instrument itself is only a minor contributor to the overall uncertainty of the measurements. FT-IR measurements of NO2 mole fractions at nominal values of 10 μmol mol(-1) calibrated with synthetic spectra lead to standard uncertainties of 0.34 μmol mol(-1) (3.4% relative). In contrast, calibration of the FT-IR instrument with SI traceable gas standards generated by a dynamic weighing system resulted in measurements results with standard uncertainties of 0.04 μmol mol(-1) (0.4% relative). When comparing the consistency of measurement results based on the synthetic calibration method against those obtained by calibrations with SI traceable gas standards, the existence of a potential bias of ~5% was observed, although this was within the stated uncertainties of the results. The FT-IR measurements of HNO3 mole fractions at nominal values of 200 nmol mol(-1) calibrated with synthetic spectra resulted in values with standard uncertainties of 23 nmol mol(-1) (11

  6. Do case-generic measures of queue performance for bypass surgery accurately reflect the waiting-list experiences of those most urgent?

    Science.gov (United States)

    Burstein, Jason; Lee, Douglas S; Alter, David A

    2006-02-01

    Queue performance is typically assessed using generic measures, which capture the queue in aggregate. The objective of this study was to examine whether case-generic measures of queue performance appropriately reflected the waiting-list experiences of those patients with greatest disease severity. We examined the queue for isolated coronary artery bypass grafting (CABG) in Ontario between April 1993 and March 2000 using data obtained from the Cardiac Care Network. Our primary measure of queue performance was the proportion of patients who received their bypass surgery within their recommended maximum waiting times (%RMWTs) in any given month. We compared case-generic measures of queue performance to case-specific measures of queue performance stratified by urgency level. The queue was largely comprised of elective cases ranging from 73% (1993) to 57%(1999). Urgent patients comprised the minority of the queue ranging from 14% (1993) to 20% (1999). Case-generic month-to-month variations in the percentage of cases completed within RMWTs (an aggregated waiting list measure encompassing the characteristics of all patients in the queue) closely resembled the experiences of elective patients (R2 = 0.81), but conversely, bore little relationship to the waiting-list experiences of those most urgent (R2 = 0.15). Case-generic measures of queue performance for bypass surgery in Ontario were not reflective of the waiting-list experiences of those most urgent. Our results reinforce the concept that urgency-specific waiting list monitoring systems are required to best evaluate and appropriately respond to fluctuations in queue performance.

  7. Dissociative recombination of HCl+

    Science.gov (United States)

    Larson, Åsa; Fonseca dos Santos, Samantha; E. Orel, Ann

    2017-08-01

    The dissociative recombination of HCl+, including both the direct and indirect mechanisms, is studied. For the direct process, the relevant electronic states are calculated ab initio by combining electron scattering calculations to obtain resonance positions and autoionization widths with multi-reference configuration interaction calculations of the ion and Rydberg states. The cross section for the direct dissociation along electronic resonant states is computed by solution of the time-dependent Schrödinger equation. For the indirect process, an upper bound value for the cross section is obtained using a vibrational frame transformation of the elements of the scattering matrix at energies just above the ionization threshold. Vibrational excitations of the ionic core from the ground vibrational state, v = 0 , to the first three excited vibrational states, v = 1 , v = 2 , and v = 3 , are considered. Autoionization is neglected and the effect of the spin-orbit splitting of the ionic potential energy upon the indirect dissociative recombination cross section is considered. The calculated cross sections are compared to measurements.

  8. Cross-calibration of the Siemens mMR: easily acquired accurate PET phantom measurements, long-term stability and reproducibility.

    Science.gov (United States)

    Keller, Sune H; Jakoby, Björn; Svalling, Susanne; Kjaer, Andreas; Højgaard, Liselotte; Klausen, Thomas L

    2016-12-01

    We present a quick and easy method to perform quantitatively accurate PET scans of typical water-filled PET plastic shell phantoms on the Siemens Biograph mMR PET/MR system. We perform regular cross-calibrations (Xcal) of our PET systems, including the PET/MR, using a Siemens mCT water phantom. The mMR calibration stability was evaluated over a 3-year period where 54 cross-calibrations were acquired, showing that the mMR on average underestimated the concentration by 16 %, consistently due to the use of MR-based μ-maps. The mMR produced the narrowest calibration ratio range with the lowest standard deviation, implying it is the most stable of the six systems in the study over a 3-year period. MMR ACCURACY WITH PREDEFINED μ-MAPS: With the latest mMR software version, VB20P, it is possible to utilize predefined phantom μ-maps. We evaluated both the system-integrated, predefined μ-map of the long mMR water phantom and our own user-defined CT-based μ-map of the mCT water phantom, which is used for cross-calibration. For seven scans, which were reconstructed with correctly segmented μ-maps, the mMR produced cross-calibration ratios of 1.00-1.02, well within the acceptance range [0.95-1.05], showing high accuracy. The mMR is the most stable PET system in this study, and the mean underestimation is no longer an issue with the easily accessible μ-map, which resulted in correct cross-calibration ratios in all seven tests. We will share the user-defined μ-map of the mCT phantom and the protocol with interested mMR users.

  9. Which cardiovascular magnetic resonance planes and sequences provide accurate measurements of branch pulmonary artery size in children with right ventricular outflow tract obstruction?

    Science.gov (United States)

    Vijarnsorn, Chodchanok; Rutledge, Jennifer M; Tham, Edythe B; Coe, James Y; Quinonez, Luis; Patton, David J; Noga, Michelle

    2014-02-01

    Children with right ventricular outflow tract obstructive (RVOTO) lesions require precise quantification of pulmonary artery (PA) size for proper management of branch PA stenosis. We aimed to determine which cardiovascular magnetic resonance (CMR) sequences and planes correlated best with cardiac catheterization and surgical measurements of branch PA size. Fifty-five children with RVOTO lesions and biventricular circulation underwent CMR prior to; either cardiac catheterization (n = 30) or surgery (n = 25) within a 6 month time frame. CMR sequences included axial black blood, axial, coronal oblique and sagittal oblique cine balanced steady-state free precession (bSSFP), and contrast-enhanced magnetic resonance angiography (MRA) with multiplanar reformatting in axial, coronal oblique, sagittal oblique, and cross-sectional planes. Maximal branch PA and stenosis (if present) diameter were measured. Comparisons of PA size on CMR were made to reference methods: (1) catheterization measurements performed in the anteroposterior plane at maximal expansion, and (2) surgical measurement obtained from a maximal diameter sound which could pass through the lumen. The mean differences (Δ) and intra class correlation (ICC) were used to determine agreement between different modalities. CMR branch PA measurements were compared to the corresponding cardiac catheterization measurements in 30 children (7.6 ± 5.6 years). Reformatted MRA showed better agreement for branch PA measurement (ICC > 0.8) than black blood (ICC 0.4-0.6) and cine sequences (ICC 0.6-0.8). Coronal oblique MRA and maximal cross sectional MRA provided the best correlation of right PA (RPA) size with ICC of 0.9 (Δ -0.1 ± 2.1 mm and Δ 0.5 ± 2.1 mm). Maximal cross sectional MRA and sagittal oblique MRA provided the best correlate of left PA (LPA) size (Δ 0.1 ± 2.4 and Δ -0.7 ± 2.4 mm). For stenoses, the best correlations were from coronal oblique MRA of right pulmonary artery (RPA) (Δ -0.2 ± 0.8 mm, ICC 0

  10. Grading More Accurately

    Science.gov (United States)

    Rom, Mark Carl

    2011-01-01

    Grades matter. College grading systems, however, are often ad hoc and prone to mistakes. This essay focuses on one factor that contributes to high-quality grading systems: grading accuracy (or "efficiency"). I proceed in several steps. First, I discuss the elements of "efficient" (i.e., accurate) grading. Next, I present analytical results…

  11. Comparison of device models for organic solar cells: Band-to-band vs. tail states recombination

    Energy Technology Data Exchange (ETDEWEB)

    Soldera, Marcos; Taretto, Kurt [Departamento de Electrotecnia, Universidad Nacional del Comahue, Buenos Aires, Neuquen (Argentina); Kirchartz, Thomas [Department of Physics, Imperial College London, South Kensington (United Kingdom)

    2012-01-15

    The efficiency-limiting recombination mechanism in bulk-heterojunction (BHJ) solar cells is a current topic of investigation and debate in organic photovoltaics. In this work, we simulate state-of-the-art BHJ solar cells using two different models. The first model takes into account band-to-band recombination and field dependent carrier generation. The second model assumes a Shockley-Read-Hall (SRH) recombination mechanism via tail states and field independent carrier generation. Additionally, we include in both cases optical modelling and, thus, position-dependent exciton generation and non-ideal exciton collection. We explore both recombination mechanisms by fitting light and dark current-voltage (JV) characteristics of BHJ cells of five materials: P3HT, MDMO-PPV, MEH-PPV, PCDTBT and PF10TBT, all blended with fullerene derivatives. We show that although main device parameters such as short circuit current, open circuit voltage, fill factor and ideality factor are accurately reproduced by both Langevin and tail recombination, only tail recombination reproduces also the ideality factor of dark characteristics accurately. Nevertheless, the model with SRH recombination via tail states needs the inclusion of external circuitry to account for the heavy shunt present in all the blends, except P3HT:PCBM, when illuminated. Finally, we propose a means to find analytical expressions for the short circuit current by assuming a linear relation between the recombination rate and the concentration of free minority carriers. The model reproduces experimental data of P3HT cells at various thickness values using realistic parameters for this material. Dark JV measurement (circles) of a PCDTBT:PC{sub 70}BM solar cell (Park et al., Nature Photon. 3, 297 (2009) [1]), the fit with the model including recombination via tail states (solid line) and the fit with the model reported by (Koster et al., Phys. Rev. B 72, 085205 (2005) [2]) that includes bimolecular band-to-band recombination

  12. Combined measurement of fetal lung volume and pulmonary artery resistance index is more accurate for prediction of neonatal respiratory distress syndrome in preterm fetuses: a pilot study.

    Science.gov (United States)

    Laban, Mohamed; Mansour, Ghada M; El-Kotb, Ahmed; Hassanin, Alaa; Laban, Zina; Saleh, Abdelrahman

    2017-10-12

    The objective of this study is to estimate optimal cut-off values for mean fetal lung volume (FLV) and pulmonary artery resistance index (PA-RI) as non-invasive measures to predict neonatal respiratory distress syndrome (RDS) in preterm fetuses. A prospective study conducted at Ain Shams University Maternity Hospital, Egypt from May 2015 to July 2017: 80 eligible women diagnosed with preterm labor were recruited at 32-36 weeks' gestation. Before delivery, three-dimensional ultrasound was used to estimate FLV using virtual organ computer-aided analysis (VOCAL), while PA-RI was measured by Doppler ultrasonography. A total of 80 women were examined. Thirty-seven (46%) of the newborns developed neonatal RDS. FLV was significantly lower in neonates who developed RDS (p = .04), whereas PARI was significantly higher in those who did not (p = .02). Cut-off values of FLV ≤27.2 cm3 and PARI ≥0.77 predicted the subsequent development of RDS. Combining both cut-offs generated a more sensitive and specific methodical approach for the prediction of RDS (sensitivity 100%, specificity 88.5%). Measurement of FLV or PA-RI can predict RDS in preterm fetuses. Combined use of both measures bolstered their predictive significance.

  13. Accurate frequency domain measurement of the best linear time-invariant approximation of linear time-periodic systems including the quantification of the time-periodic distortions

    Science.gov (United States)

    Louarroudi, E.; Pintelon, R.; Lataire, J.

    2014-10-01

    Time-periodic (TP) phenomena occurring, for instance, in wind turbines, helicopters, anisotropic shaft-bearing systems, and cardiovascular/respiratory systems, are often not addressed when classical frequency response function (FRF) measurements are performed. As the traditional FRF concept is based on the linear time-invariant (LTI) system theory, it is only approximately valid for systems with varying dynamics. Accordingly, the quantification of any deviation from this ideal LTI framework is more than welcome. The “measure of deviation” allows us to define the notion of the best LTI (BLTI) approximation, which yields the best - in mean square sense - LTI description of a linear time-periodic LTP system. By taking into consideration the TP effects, it is shown in this paper that the variability of the BLTI measurement can be reduced significantly compared with that of classical FRF estimators. From a single experiment, the proposed identification methods can handle (non-)linear time-periodic [(N)LTP] systems in open-loop with a quantification of (i) the noise and/or the NL distortions, (ii) the TP distortions and (iii) the transient (leakage) errors. Besides, a geometrical interpretation of the BLTI approximation is provided, leading to a framework called vector FRF analysis. The theory presented is supported by numerical simulations as well as real measurements mimicking the well-known mechanical Mathieu oscillator.

  14. A new accurate 3D measurement tool to assess the range of motion of the tongue in oral cancer patients: a standardized model

    NARCIS (Netherlands)

    van Dijk, Simone; van Alphen, M.J.A.; Jacobi, Irene; Smeele, Ludwig E.; van der Heijden, Ferdinand; Balm, Alfonsus Jacobus Maria; Balm, Alfons J.M.

    2016-01-01

    In oral cancer treatment, function loss such as speech and swallowing deterioration can be severe, mostly due to reduced lingual mobility. Until now, there is no standardized measurement tool for tongue mobility and pre-operative prediction of function loss is based on expert opinion instead of

  15. Radioactive Body Burden Measurements in 131Iodine Therapy for Differentiated Thyroid Cancer: Effect of Recombinant Thyroid Stimulating Hormone in Whole Body 131Iodine Clearance

    OpenAIRE

    Ravichandran, Ramamoorthy; Al Saadi, Amal; Al Balushi, Naima

    2014-01-01

    Protocols in the management of differentiated thyroid cancer, recommend adequate thyroid stimulating hormone (TSH) stimulation for radioactive 131I administrations, both for imaging and subsequent ablations. Commonly followed method is to achieve this by endogenous TSH stimulation by withdrawal of thyroxine. Numerous studies worldwide have reported comparable results with recombinant human thyroid stimulating hormone (rhTSH) intervention as conventional thyroxine hormone withdrawal. Radiation...

  16. Accurate measurement of {sup 3}J{sub HNHα} couplings in small or disordered proteins from WATERGATE-optimized TROSY spectra

    Energy Technology Data Exchange (ETDEWEB)

    Roche, Julien; Ying, Jinfa; Bax, Ad, E-mail: bax@nih.gov [National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Laboratory of Chemical Physics (United States)

    2016-01-15

    Provided that care is taken in adjusting the WATERGATE element of a {sup 1}H–{sup 15}N TROSY-HSQC experiment, such that neither the water magnetization nor the {sup 1}H{sup α} protons are inverted by its final 180° pulse, {sup 3}J{sub HNHα} couplings can be measured directly from splittings in the {sup 1}H dimension of the spectrum. With band-selective {sup 1}H decoupling, very high {sup 15}N resolution can be achieved. A complete set of {sup 3}J{sub HNHα} values, ranging from 3.4 to 10.1 Hz was measured for the 56-residue third domain of IgG-binding protein G (GB3). Using the H–N–C{sup α}–H{sup α} dihedral angles extracted from a RDC-refined structure of GB3, {sup 3}J{sub HNHα} values predicted by a previously parameterized Karplus equation agree to within a root-mean-square deviation (rmsd) of 0.37 Hz with the experimental data. Values measured for the Alzheimer’s implicated Aβ{sup 1−40} peptide fit to within an rmsd of 0.45 Hz to random coil {sup 3}J{sub HNHα} values.

  17. Accurate 238U(n , 2 n )237U reaction cross-section measurements from 6.5 to 14.8 MeV

    Science.gov (United States)

    Krishichayan, Bhike, M.; Tornow, W.; Tonchev, A. P.; Kawano, T.

    2017-10-01

    The cross section for the 238U(n ,2 n )237U reaction has been measured in the incident neutron energy range from 6.5 to 14.8 MeV in small energy steps using an activation technique. Monoenergetic neutron beams were produced via the 2H(d ,n )3He and 3H(d ,n )4He reactions. 238U targets were activated along with Au and Al monitor foils to determine the incident neutron flux. The activity of the reaction products was measured in TUNL's low-background counting facility using high-resolution γ -ray spectroscopy. The results are compared with previous measurements and latest data evaluations. Statistical-model calculations, based on the Hauser-Feshbach formalism, have been carried out using the CoH3 code and are compared with the experimental results. The present self-consistent and high-quality data are important for stockpile stewardship and nuclear forensic purposes as well as for the design and operation of fast reactors.

  18. Accurate Assessment of the Oxygen Reduction Electrocatalytic Activity of Mn/Polypyrrole Nanocomposites Based on Rotating Disk Electrode Measurements, Complemented with Multitechnique Structural Characterizations

    Directory of Open Access Journals (Sweden)

    Patrizia Bocchetta

    2016-01-01

    Full Text Available This paper reports on the quantitative assessment of the oxygen reduction reaction (ORR electrocatalytic activity of electrodeposited Mn/polypyrrole (PPy nanocomposites for alkaline aqueous solutions, based on the Rotating Disk Electrode (RDE method and accompanied by structural characterizations relevant to the establishment of structure-function relationships. The characterization of Mn/PPy films is addressed to the following: (i morphology, as assessed by Field-Emission Scanning Electron Microscopy (FE-SEM and Atomic Force Microscope (AFM; (ii local electrical conductivity, as measured by Scanning Probe Microscopy (SPM; and (iii molecular structure, accessed by Raman Spectroscopy; these data provide the background against which the electrocatalytic activity can be rationalised. For comparison, the properties of Mn/PPy are gauged against those of graphite, PPy, and polycrystalline-Pt (poly-Pt. Due to the literature lack of accepted protocols for precise catalytic activity measurement at poly-Pt electrode in alkaline solution using the RDE methodology, we have also worked on the obtainment of an intralaboratory benchmark by evidencing some of the time-consuming parameters which drastically affect the reliability and repeatability of the measurement.

  19. An Accurate and Efficient Algorithm for Detection of Radio Bursts with an Unknown Dispersion Measure, for Single-dish Telescopes and Interferometers

    Science.gov (United States)

    Zackay, Barak; Ofek, Eran O.

    2017-01-01

    Astronomical radio signals are subjected to phase dispersion while traveling through the interstellar medium. To optimally detect a short-duration signal within a frequency band, we have to precisely compensate for the unknown pulse dispersion, which is a computationally demanding task. We present the “fast dispersion measure transform” algorithm for optimal detection of such signals. Our algorithm has a low theoretical complexity of 2{N}f{N}t+{N}t{N}{{Δ }}{{log}}2({N}f), where Nf, Nt, and NΔ are the numbers of frequency bins, time bins, and dispersion measure bins, respectively. Unlike previously suggested fast algorithms, our algorithm conserves the sensitivity of brute-force dedispersion. Our tests indicate that this algorithm, running on a standard desktop computer and implemented in a high-level programming language, is already faster than the state-of-the-art dedispersion codes running on graphical processing units (GPUs). We also present a variant of the algorithm that can be efficiently implemented on GPUs. The latter algorithm’s computation and data-transport requirements are similar to those of a two-dimensional fast Fourier transform, indicating that incoherent dedispersion can now be considered a nonissue while planning future surveys. We further present a fast algorithm for sensitive detection of pulses shorter than the dispersive smearing limits of incoherent dedispersion. In typical cases, this algorithm is orders of magnitude faster than enumerating dispersion measures and coherently dedispersing by convolution. We analyze the computational complexity of pulsed signal searches by radio interferometers. We conclude that, using our suggested algorithms, maximally sensitive blind searches for dispersed pulses are feasible using existing facilities. We provide an implementation of these algorithms in Python and MATLAB.

  20. Micrometry combined with profile mapping for the absolute measurement of Integrated Column Density (ICD) and for accurate X-ray mass attenuation coefficients using XERT

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M. Tauhidul; Rae, Nicholas A.; Glover, Jack L.; Barnea, Zwi [School of Physics, University of Melbourne, Victoria 3010 (Australia); Chantler, Christopher T., E-mail: chantler@physics.unimelb.edu.a [School of Physics, University of Melbourne, Victoria 3010 (Australia)

    2010-07-21

    Absolute values of the column densities [{rho}t]{sub c} of four gold foils were measured using micrometry combined with the 2D X-ray attenuation profile. The absolute calibration of [{rho}t]{sub c} was made with a reference foil and the [{rho}t]{sub c} of other foils were determined following the thickness transfer method. By this method, we obtain absolute calibration to 0.1% or better which was not possible using only the X-ray map of a single foil over its central region.

  1. Radioactive body burden measurements in (131)iodine therapy for differentiated thyroid cancer: effect of recombinant thyroid stimulating hormone in whole body (131)iodine clearance.

    Science.gov (United States)

    Ravichandran, Ramamoorthy; Al Saadi, Amal; Al Balushi, Naima

    2014-01-01

    Protocols in the management of differentiated thyroid cancer, recommend adequate thyroid stimulating hormone (TSH) stimulation for radioactive (131)I administrations, both for imaging and subsequent ablations. Commonly followed method is to achieve this by endogenous TSH stimulation by withdrawal of thyroxine. Numerous studies worldwide have reported comparable results with recombinant human thyroid stimulating hormone (rhTSH) intervention as conventional thyroxine hormone withdrawal. Radiation safety applications call for the need to understand radioactive (131)I (RA(131)I) clearance pattern to estimate whole body doses when this new methodology is used in our institution. A study of radiation body burden estimation was undertaken in two groups of patients treated with RA(131)I; (a) one group of patients having thyroxine medication suspended for 5 weeks prior to therapy and (b) in the other group retaining thyroxine support with two rhTSH injections prior to therapy with RA(131)I. Sequential exposure rates at 1 m in the air were measured in these patients using a digital auto-ranging beta gamma survey instrument calibrated for measurement of exposure rates. The mean measured exposure rates at 1 m in μSv/h immediately after administration and at 24 h intervals until 3 days are used for calculating of effective ½ time of clearance of administered activity in both groups of patients, 81 patients in conventionally treated group (stop thyroxine) and 22 patients with rhTSH administration. The (131)I activities ranged from 2.6 to 7.9 GBq. The mean administered (131)I activities were 4.24 ± 0.95 GBq (n = 81) in "stop hormone" group and 5.11 ± 1.40 GBq (n = 22) in rhTSH group. The fall of radioactive body burden showed two clearance patterns within observed 72 h. Calculated T½eff values were 16.45 h (stop hormone group) 12.35 h (rhTSH group) for elapsed period of 48 h. Beyond 48 h post administration, clearance of RA(131)I takes place with T½eff> 20 h in both groups

  2. A simple, fast and accurate in-situ method to measure the rate of transport of redox species through membranes for lithium batteries

    Science.gov (United States)

    Meddings, Nina; Owen, John R.; Garcia-Araez, Nuria

    2017-10-01

    Lithium ion conducting membranes are important to protect the lithium metal electrode and act as a barrier to crossover species such as polysulphides in Li-S systems, redox mediators in Li-O2 cells or dissolved cathode species or electrolyte oxidation products in high voltage Li-ion batteries. We present an in-situ method for measuring permeability of membranes to crossover redox species. The method employs a 'Swagelok' cell design equipped with a glassy carbon working electrode, in which redox species are placed initially in the counter electrode compartment only. Permeability through the membrane, which separates working and counter electrodes, is determined using a square wave voltammetry technique that allows the concentration of crossover redox species to be evaluated over time with very high precision. We test the method using a model and well-behaved electrochemical system to demonstrate its sensitivity, reproducibility and reliability relative to alternative approaches. This new method offers advantages in terms of small electrolyte volume, and simple, fast, quantitative and in-situ measurement.

  3. Technical note: Can the sulfur hexafluoride tracer gas technique be used to accurately measure enteric methane production from ruminally cannulated cattle?

    Science.gov (United States)

    Beauchemin, K A; Coates, T; Farr, B; McGinn, S M

    2012-08-01

    An experiment was conducted to determine whether using ruminally cannulated cattle affects the estimate of enteric methane (CH(4)) emissions when using the sulfur hexafluoride (SF(6)) tracer technique with samples taken from a head canister. Eleven beef cattle were surgically fitted with several types of ruminal cannula (2C, 3C, 3C+washer, 9C; Bar Diamond, Parma, ID). The 2C and 3C models (outer and inner flanges with opposite curvature) had medium to high leakage, whereas the 9C models (outer and inner flanges with the same curvature) provided minimum to moderate leakage of gas. A total of 48 cow-day measurements were conducted. For each animal, a permeation tube containing sulfur hexafluoride (SF(6)) was placed in the rumen, and a sample of air from around the nose and mouth was drawn through tubing into an evacuated canister (head canister). A second sample of air was collected from outside the rumen near the cannula into another canister (cannula canister). Background concentrations were also monitored. The methane (CH(4)) emission was estimated from the daily CH(4) and SF(6) concentrations in the head canister (uncorrected). The permeation SF(6) release rate was then partitioned based on the proportion of the SF(6) concentration measured in the head vs. the cannula canister. The CH(4) emissions at each site were calculated using the two release rates and the two CH(4):SF(6) concentration ratios. The head and cannula emissions were summed to obtain the total emission (corrected). The difference (corrected - uncorrected) in CH4 emission was attributed to the differences in CH(4):SF(6) ratio at the 2 exit locations. The proportions of CH(4) and SF(6) recovered at the head were greater (P 0.05; 2C, 6% and 4%; 3C, 17% and 15%; 3C+washer, 19% and 14%). Uncorrected CH(4) emissions were ± 10% of corrected emissions for 53% of the cow-day measurements. Only when more than 80% of the SF(6) escaped via the rumen did the difference between the uncorrected and corrected

  4. Dispersive and steady-state recombination in organic disordered semiconductors

    Science.gov (United States)

    Hofacker, Andreas; Neher, Dieter

    2017-12-01

    Charge carrier recombination in organic disordered semiconductors is strongly influenced by the thermalization of charge carriers in the density of states (DOS). Measurements of recombination dynamics, conducted under transient or steady-state conditions, can easily be misinterpreted when a detailed understanding of the interplay of thermalization and recombination is missing. To enable adequate measurement analysis, we solve the multiple-trapping problem for recombining charge carriers and analyze it in the transient and steady excitation paradigm for different DOS distributions. We show that recombination rates measured after pulsed excitation are inherently time dependent since recombination gradually slows down as carriers relax in the DOS. When measuring the recombination order after pulsed excitation, this leads to an apparent high-order recombination at short times. As times goes on, the recombination order approaches an asymptotic value. For the Gaussian and the exponential DOS distributions, this asymptotic value equals the recombination order of the equilibrated system under steady excitation. For a more general DOS distribution, the recombination order can also depend on the carrier density, under both transient and steady-state conditions. We conclude that transient experiments can provide rich information about recombination in and out of equilibrium and the underlying DOS occupation provided that consistent modeling of the system is performed.

  5. New experimental methodology, setup and LabView program for accurate absolute thermoelectric power and electrical resistivity measurements between 25 and 1600 K: application to pure copper, platinum, tungsten, and nickel at very high temperatures.

    Science.gov (United States)

    Abadlia, L; Gasser, F; Khalouk, K; Mayoufi, M; Gasser, J G

    2014-09-01

    In this paper we describe an experimental setup designed to measure simultaneously and very accurately the resistivity and the absolute thermoelectric power, also called absolute thermopower or absolute Seebeck coefficient, of solid and liquid conductors/semiconductors over a wide range of temperatures (room temperature to 1600 K in present work). A careful analysis of the existing experimental data allowed us to extend the absolute thermoelectric power scale of platinum to the range 0-1800 K with two new polynomial expressions. The experimental device is controlled by a LabView program. A detailed description of the accurate dynamic measurement methodology is given in this paper. We measure the absolute thermoelectric power and the electrical resistivity and deduce with a good accuracy the thermal conductivity using the relations between the three electronic transport coefficients, going beyond the classical Wiedemann-Franz law. We use this experimental setup and methodology to give new very accurate results for pure copper, platinum, and nickel especially at very high temperatures. But resistivity and absolute thermopower measurement can be more than an objective in itself. Resistivity characterizes the bulk of a material while absolute thermoelectric power characterizes the material at the point where the electrical contact is established with a couple of metallic elements (forming a thermocouple). In a forthcoming paper we will show that the measurement of resistivity and absolute thermoelectric power characterizes advantageously the (change of) phase, probably as well as DSC (if not better), since the change of phases can be easily followed during several hours/days at constant temperature.

  6. New experimental methodology, setup and LabView program for accurate absolute thermoelectric power and electrical resistivity measurements between 25 and 1600 K: Application to pure copper, platinum, tungsten, and nickel at very high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Abadlia, L.; Mayoufi, M. [Laboratoire de Chimie des Matériaux Inorganiques, Université Badji-Mokhtar Annaba, BP12, 23000 Annaba (Algeria); Gasser, F.; Khalouk, K.; Gasser, J. G., E-mail: jean-georges.gasser@univ-lorraine.fr [Laboratoire de Chimie et Physique - Approche Multi-échelle des Milieux Complexes (LCP-A2MC) Institut de Chimie, Physique et Matériaux, Université de Lorraine, 1 Boulevard Arago - 57078 Metz cedex 3 (France)

    2014-09-15

    In this paper we describe an experimental setup designed to measure simultaneously and very accurately the resistivity and the absolute thermoelectric power, also called absolute thermopower or absolute Seebeck coefficient, of solid and liquid conductors/semiconductors over a wide range of temperatures (room temperature to 1600 K in present work). A careful analysis of the existing experimental data allowed us to extend the absolute thermoelectric power scale of platinum to the range 0-1800 K with two new polynomial expressions. The experimental device is controlled by a LabView program. A detailed description of the accurate dynamic measurement methodology is given in this paper. We measure the absolute thermoelectric power and the electrical resistivity and deduce with a good accuracy the thermal conductivity using the relations between the three electronic transport coefficients, going beyond the classical Wiedemann-Franz law. We use this experimental setup and methodology to give new very accurate results for pure copper, platinum, and nickel especially at very high temperatures. But resistivity and absolute thermopower measurement can be more than an objective in itself. Resistivity characterizes the bulk of a material while absolute thermoelectric power characterizes the material at the point where the electrical contact is established with a couple of metallic elements (forming a thermocouple). In a forthcoming paper we will show that the measurement of resistivity and absolute thermoelectric power characterizes advantageously the (change of) phase, probably as well as DSC (if not better), since the change of phases can be easily followed during several hours/days at constant temperature.

  7. New experimental methodology, setup and LabView program for accurate absolute thermoelectric power and electrical resistivity measurements between 25 and 1600 K: Application to pure copper, platinum, tungsten, and nickel at very high temperatures

    Science.gov (United States)

    Abadlia, L.; Gasser, F.; Khalouk, K.; Mayoufi, M.; Gasser, J. G.

    2014-09-01

    In this paper we describe an experimental setup designed to measure simultaneously and very accurately the resistivity and the absolute thermoelectric power, also called absolute thermopower or absolute Seebeck coefficient, of solid and liquid conductors/semiconductors over a wide range of temperatures (room temperature to 1600 K in present work). A careful analysis of the existing experimental data allowed us to extend the absolute thermoelectric power scale of platinum to the range 0-1800 K with two new polynomial expressions. The experimental device is controlled by a LabView program. A detailed description of the accurate dynamic measurement methodology is given in this paper. We measure the absolute thermoelectric power and the electrical resistivity and deduce with a good accuracy the thermal conductivity using the relations between the three electronic transport coefficients, going beyond the classical Wiedemann-Franz law. We use this experimental setup and methodology to give new very accurate results for pure copper, platinum, and nickel especially at very high temperatures. But resistivity and absolute thermopower measurement can be more than an objective in itself. Resistivity characterizes the bulk of a material while absolute thermoelectric power characterizes the material at the point where the electrical contact is established with a couple of metallic elements (forming a thermocouple). In a forthcoming paper we will show that the measurement of resistivity and absolute thermoelectric power characterizes advantageously the (change of) phase, probably as well as DSC (if not better), since the change of phases can be easily followed during several hours/days at constant temperature.

  8. The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: single-probe measurements from DR12 galaxy clustering - towards an accurate model

    Science.gov (United States)

    Chuang, Chia-Hsun; Pellejero-Ibanez, Marcos; Rodríguez-Torres, Sergio; Ross, Ashley J.; Zhao, Gong-bo; Wang, Yuting; Cuesta, Antonio J.; Rubiño-Martín, J. A.; Prada, Francisco; Alam, Shadab; Beutler, Florian; Eisenstein, Daniel J.; Gil-Marín, Héctor; Grieb, Jan Niklas; Ho, Shirley; Kitaura, Francisco-Shu; Percival, Will J.; Rossi, Graziano; Salazar-Albornoz, Salvador; Samushia, Lado; Sánchez, Ariel G.; Satpathy, Siddharth; Slosar, Anže; Thomas, Daniel; Tinker, Jeremy L.; Tojeiro, Rita; Vargas-Magaña, Mariana; Vazquez, Jose A.; Brownstein, Joel R.; Nichol, Robert C.; Olmstead, Matthew D.

    2017-10-01

    We analyse the broad-range shape of the monopole and quadrupole correlation functions of the Baryon Oscillation Spectroscopic Survey Data Release 12 (DR12) CMASS and LOWZ galaxy sample to obtain constraints on the Hubble expansion rate H(z), the angular-diameter distance DA(z), the normalized growth rate f(z)σ8(z) and the physical matter density Ωm h2. We adopt wide and flat priors on all model parameters in order to ensure the results are those of a 'single-probe' galaxy clustering analysis. We also marginalize over three nuisance terms that account for potential observational systematics affecting the measured monopole. However, such Monte Carlo Markov Chain analysis is computationally expensive for advanced theoretical models. We develop a new methodology to speed up the analysis. Using the range 40 h-1 Mpc < s < 180 h-1 Mpc, we obtain {DA(z)rs,fid/rs (Mpc), H(z)rs/rs,fid km s-1 Mpc-1, f(z)σ8(z), Ωm h2} = {956 ± 28, 75.0 ± 4.0, 0.397 ± 0.073, 0.143 ± 0.017} at z = 0.32 and {1421 ± 23, 96.7 ± 2.7, 0.497 ± 0.058, 0.137 ± 0.015} at z = 0.59 where rs is the comoving sound horizon at the drag epoch and rs,fid = 147.66 Mpc for the fiducial cosmology used in this study. Combining our measurements with Planck data, we obtain Ωm = 0.306 ± 0.009, H0 = 67.9 ± 0.7 km s-1 Mpc-1 and σ8 = 0.815 ± 0.009 assuming Λcold dark matter (CDM); Ωk = 0.000 ± 0.003 and w = -1.02 ± 0.08 assuming owCDM. Our results show no tension with the flat ΛCDM cosmological paradigm. This paper is part of a set that analyses the final galaxy clustering data set from Baryon Oscillation Spectroscopic Survey.

  9. Accurate Measurement in the Field of the Earth of the General-Relativistic Precession of the LAGEOS II Pericenter and New Constraints on Non-Newtonian Gravity

    Science.gov (United States)

    Lucchesi, David M.; Peron, Roberto

    2010-12-01

    The pericenter shift of a binary system represents a suitable observable to test for possible deviations from the Newtonian inverse-square law in favor of new weak interactions between macroscopic objects. We analyzed 13 years of tracking data of the LAGEOS satellites with GEODYN II software but with no models for general relativity. From the fit of LAGEOS II pericenter residuals we have been able to obtain a 99.8% agreement with the predictions of Einstein’s theory. This result may be considered as a 99.8% measurement in the field of the Earth of the combination of the γ and β parameters of general relativity, and it may be used to constrain possible deviations from the inverse-square law in favor of new weak interactions parametrized by a Yukawa-like potential with strength α and range λ. We obtained |α|≲1×10-11, a huge improvement at a range of about 1 Earth radius.

  10. Toward Robust Climate Baselining: Objective Assessment of Climate Change Using Widely Distributed Miniaturized Sensors for Accurate World-Wide Geophysical Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Teller, E; Leith, C; Canavan, G; Marion, J; Wood, L

    2001-11-13

    A gap-free, world-wide, ocean-, atmosphere-, and land surface-spanning geophysical data-set of three decades time-duration containing the full set of geophysical parameters characterizing global weather is the scientific perquisite for defining the climate; the generally-accepted definition in the meteorological community is that climate is the 30-year running-average of weather. Until such a tridecadal climate base line exists, climate change discussions inevitably will have a semi-speculative, vs. a purely scientific, character, as the baseline against which changes are referenced will be at least somewhat uncertain. The contemporary technology base provides ways-and-means for commencing the development of such a meteorological measurement-intensive climate baseline, moreover with a program budget far less than the {approx}$2.5 B/year which the US. currently spends on ''global change'' studies. In particular, the recent advent of satellite-based global telephony enables real-time control of, and data-return from, instrument packages of very modest scale, and Silicon Revolution-based sensor, data-processing and -storage advances permit 'intelligent' data-gathering payloads to be created with 10 gram-scale mass budgets. A geophysical measurement system implemented in such modern technology is a populous constellation 03 long-lived, highly-miniaturized robotic weather stations deployed throughout the weather-generating portions of the Earths atmosphere, throughout its oceans and across its land surfaces. Leveraging the technological advances of the OS, the filly-developed atmospheric weather station of this system has a projected weight of the order of 1 ounce, and contains a satellite telephone, a GPS receiver, a full set of atmospheric sensing instruments and a control computer - and has an operational life of the order of 1 year and a mass-production cost of the order of $20. Such stations are effectively &apos

  11. Electrical Detection of C-Reactive Protein Using a Single Free-Standing, Thermally Controlled Piezoresistive Microcantilever for Highly Reproducible and Accurate Measurements

    Directory of Open Access Journals (Sweden)

    Long-Sun Huang

    2013-07-01

    Full Text Available This study demonstrates a novel method for electrical detection of C-reactive protein (CRP as a means of identifying an infection in the body, or as a cardiovascular disease risk assay. The method uses a single free-standing, thermally controlled piezoresistive microcantilever biosensor. In a commonly used sensing arrangement of conventional dual cantilevers in the Wheatstone bridge circuit, reference and gold-coated sensing cantilevers that inherently have heterogeneous surface materials and different multilayer structures may yield independent responses to the liquid environmental changes of chemical substances, flow field and temperature, leading to unwanted signal disturbance for biosensing targets. In this study, the single free-standing microcantilever for biosensing applications is employed to resolve the dual-beam problem of individual responses in chemical solutions and, in a thermally controlled system, to maintain its sensor performance due to the sensitive temperature effect. With this type of single temperature-controlled microcantilever sensor, the electrical detection of various CRP concentrations from 1 µg/mL to 200 µg/mL was performed, which covers the clinically relevant range. Induced surface stresses were measured at between 0.25 N/m and 3.4 N/m with high reproducibility. Moreover, the binding affinity (KD of CRP and anti-CRP interaction was found to be 18.83 ± 2.99 µg/mL, which agreed with results in previous reported studies. This biosensing technique thus proves valuable in detecting inflammation, and in cardiovascular disease risk assays.

  12. How accurate is our misinformation? A randomized comparison of four survey interview methods to measure risk behavior among young adults in the Dominican Republic

    Directory of Open Access Journals (Sweden)

    Sigrid Vivo

    Full Text Available Objective: To identify the most effective survey interview method for measuring risk behavior among young adults in the Dominican Republic. Methods: 1200 young adults were randomized to one of four different survey interview methods: two interviewer-assisted methods [face-to-face interview (FTFI, and computer-assisted telephone interview (CATI], and two self-administered methods [self-administered interview (SAI, and audio computer-assisted, self-administered interview (ACASI]. Youth were asked about a wide range of youth-specific risk behaviors, including violence, substance use, as well as sexual and reproductive health. Quality of data collected was examined by looking at how the survey was administered, including identifying two sources of errors that typically threaten data quality11 This study assumes that bias does not change with sample size. In order to increase the sample size, the data collection period was extended, leaving everything else unchanged. It is, therefore, assumed that the decreasing effects of the learning curve are negligible.: (i errors at the individual level with regards to survey methodology performance and cognitive difficulties [measured with the Response Consistency Index (RCI]; and (ii errors at the aggregate level (how desirability bias, interviewer gender, and interview privacy settings affect responses. Results: No statistically significant differences in participant non-response rates were found at the individual level across all survey interview methods. At the individual question level, self-completion methods generated higher non-response and error rates than assisted methods. The SAI method showed the poorest performance of all four methods in terms of non-response rate (1.6%22 Percentage of data with non-response values at the question level. and RCI (83.0%.At the aggregate level, the prevalence of several key risk indicators was statistically significant between methods. Using means-adjustment for

  13. Surface recombination velocity of silicon wafers by photoluminescence

    Science.gov (United States)

    Baek, D.; Rouvimov, S.; Kim, B.; Jo, T.-C.; Schroder, D. K.

    2005-03-01

    Photoluminescence (PL) and optical reflection measurements, obtained in the two-wavelength SiPHER PL instrument, are used to determine the surface recombination velocity of silicon wafers. Local measurements and contour maps are possible allowing surface recombination maps to be displayed. This instrument also allows doping and trap density measurements. Surface recombination velocities from 10 to 106cm/s can be measured on low or high resistivity polished and epitaxial wafers.

  14. An Immunoassay to Rapidly Measure Acetaminophen Protein Adducts Accurately Identifies Patients With Acute Liver Injury or Failure.

    Science.gov (United States)

    Roberts, Dean W; Lee, William M; Hinson, Jack A; Bai, Shasha; Swearingen, Christopher J; Stravitz, R Todd; Reuben, Adrian; Letzig, Lynda; Simpson, Pippa M; Rule, Jody; Fontana, Robert J; Ganger, Daniel; Reddy, K Rajender; Liou, Iris; Fix, Oren; James, Laura P

    2017-04-01

    A rapid and reliable point-of-care assay to detect acetaminophen protein adducts in the serum of patients with acute liver injury could improve diagnosis and management. AcetaSTAT is a competitive immunoassay used to measure acetaminophen protein adducts formed by toxic metabolites in serum samples from patients. We compared the accuracy of AcetaSTAT vs high-pressure liquid chromatography with electrochemical detection (HPLC-EC; a sensitive and specific quantitative analytic assay) to detect acetaminophen protein adducts. We collected serum samples from 19 healthy individuals (no liver injury, no recent acetaminophen use), 29 patients without acetaminophen-associated acute liver injury, and 33 patients with acetaminophen-associated acute liver injury participating in the Acute Liver Failure Study Group registry. Each serum sample was analyzed by AcetaSTAT (reported as test band amplitude) and HPLC-EC (the reference standard). We also collected data on patient age, sex, weight, level of alanine aminotransferase on test day and peak values, concentration of acetaminophen, diagnoses (by site investigator and causality review committee), and outcome after 21 days. Differences between groups were analyzed using the Fisher exact test for categoric variables and the Kruskal-Wallis test or rank-sum test for continuous variables. AcetaSTAT discriminated between patients with and without acetaminophen-associated acute liver injury; the median AcetaSTAT test band amplitude for patients with acetaminophen-associated acute liver injury was 584 (range, 222-1027) vs 3678 (range, 394-8289) for those without (P acetaminophen-associated acute liver injury with 100% sensitivity, 86.2% specificity, a positive predictive value of 89.2%, and a negative predictive value of 100%. Results from AcetaSTAT were positive in 4 subjects who received a causality review committee diagnosis of non-acetaminophen-associated acute liver injury; HPLC-EC and biochemical profiles were consistent with

  15. Accurate determination of antenna directivity

    DEFF Research Database (Denmark)

    Dich, Mikael

    1997-01-01

    The derivation of a formula for accurate estimation of the total radiated power from a transmitting antenna for which the radiated power density is known in a finite number of points on the far-field sphere is presented. The main application of the formula is determination of directivity from power......-pattern measurements. The derivation is based on the theory of spherical wave expansion of electromagnetic fields, which also establishes a simple criterion for the required number of samples of the power density. An array antenna consisting of Hertzian dipoles is used to test the accuracy and rate of convergence...

  16. Peel resistance of adhesive bonds accurately measured

    Science.gov (United States)

    1965-01-01

    Strength of adhesive bond between layers of laminated material is tested by peel force to the facing with a tensile testing machine. Testing jig has stainless steel rollers which constrain material to move horizontally while maintaining free end of facing at constant 90 deg angle.

  17. Accurate test limits under prescribed consumer risk

    NARCIS (Netherlands)

    Albers, Willem/Wim; Arts, G.R.J.; Kallenberg, W.C.M.

    1997-01-01

    Measurement errors occurring during inspection of manufactured parts force producers to replace specification limits by slightly more strict test limits. Here accurate test limits are presented which maximize the yield while limiting the fraction of defectives reaching the consumer.

  18. Interaction of Reactive Gas Flows and Ceramics at High Temperature - Experimental Methods for the Measurement of Species Recombination during Planetary Entry

    Science.gov (United States)

    2006-02-01

    Species Recombination during Planetary Entry Marianne BALAT-PICHELIN Laboratoire Procédés, Matériaux et Energie Solaire , PROMES-CNRS, UPR 8521 rue du...PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Laboratoire Procédés, Matériaux et Energie Solaire , PROMES-CNRS, UPR 8521 rue du four solaire 66120...four solaire 66120 Font-Romeu Odeillo France Tél : +33 468 307 768 Fax : +33 468 302 940 balat@promes.cnrs.fr 1. INTRODUCTION During the

  19. Studies with an immobilized metal affinity chromatography cassette system involving binuclear triazacyclononane-derived ligands: automation of batch adsorption measurements with tagged recombinant proteins.

    Science.gov (United States)

    Petzold, Martin; Coghlan, Campbell J; Hearn, Milton T W

    2014-07-18

    This study describes the determination of the adsorption isotherms and binding kinetics of tagged recombinant proteins using a recently developed IMAC cassette system and employing automated robotic liquid handling procedures for IMAC resin screening. These results confirm that these new IMAC resins, generated from a variety of different metal-charged binuclear 1,4,7-triaza-cyclononane (tacn) ligands, interact with recombinant proteins containing a novel N-terminal metal binding tag, NT1A, with static binding capacities similar to those obtained with conventional hexa-His tagged proteins, but with significantly increased association constants. In addition, higher kinetic binding rates were observed with these new IMAC systems, an attribute that can be positively exploited to increase process productivity. The results from this investigation demonstrate that enhancements in binding capacities and affinities were achieved with these new IMAC resins and chosen NT1A tagged protein. Further, differences in the binding performances of the bis(tacn) xylenyl-bridged ligands were consistent with the distance between the metal binding centres of the two tacn moieties, the flexibility of the ligand and the potential contribution from the aromatic ring of the xylenyl group to undergo π/π stacking interactions with the tagged proteins. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Accurate Modeling of Advanced Reflectarrays

    DEFF Research Database (Denmark)

    Zhou, Min

    of the incident field, the choice of basis functions, and the technique to calculate the far-field. Based on accurate reference measurements of two offset reflectarrays carried out at the DTU-ESA Spherical NearField Antenna Test Facility, it was concluded that the three latter factors are particularly important...... to the conventional phase-only optimization technique (POT), the geometrical parameters of the array elements are directly optimized to fulfill the far-field requirements, thus maintaining a direct relation between optimization goals and optimization variables. As a result, better designs can be obtained compared...... using the GDOT to demonstrate its capabilities. To verify the accuracy of the GDOT, two offset contoured beam reflectarrays that radiate a high-gain beam on a European coverage have been designed and manufactured, and subsequently measured at the DTU-ESA Spherical Near-Field Antenna Test Facility...

  1. Determination of the trap-assisted recombination strength in polymer light emitting diodes

    NARCIS (Netherlands)

    Kuik, M.; Nicolai, H.T.; Lenes, M.; Wetzelaer, G.-J.A.H.; Lu, M.; Blom, P.W.M.

    2011-01-01

    The recombination processes in poly(p -phenylene vinylene) based polymer light-emitting diodes (PLEDs) are investigated. Photogenerated current measurements on PLED device structures reveal that next to the known Langevin recombination also trap-assisted recombination is an important recombination

  2. Expression of Recombinant Antibodies

    OpenAIRE

    André eFrenzel; Michael eHust; Thomas eSchirrmann

    2013-01-01

    Recombinant antibodies are highly specific detection probes in research, diagnostics, and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transg...

  3. Groundwater recharge: Accurately representing evapotranspiration

    CSIR Research Space (South Africa)

    Bugan, Richard DH

    2011-09-01

    Full Text Available Groundwater recharge is the basis for accurate estimation of groundwater resources, for determining the modes of water allocation and groundwater resource susceptibility to climate change. Accurate estimations of groundwater recharge with models...

  4. Recombination hotspots and host susceptibility modulate the adaptive value of recombination during maize streak virus evolution

    Directory of Open Access Journals (Sweden)

    Monjane Adérito L

    2011-12-01

    - of the breakpoints required to re-create MSV-MatA. Although the MSV-sensitive maize genotype gave rise to the greatest variety of recombinants, the measured fitness of each of these recombinants correlated with their similarity to MSV-MatA. Conclusions The mechanistic predispositions of different MSV genomic regions to recombination can strongly influence the accessibility of high-fitness MSV recombinants. The frequency with which the fittest recombinant MSV genomes arise also correlates directly with the escalating selection pressures imposed by increasingly MSV-resistant maize hosts.

  5. Products of Dissociative Recombination in the Ionosphere

    Science.gov (United States)

    Cosby, Philip

    1996-01-01

    SRI International undertook a novel experimental measurement of the product states formed by dissociative recombination (DR) of O2(+), NO(+), and N2(+) as a function of both electron energy and reactant ion vibrational level. For these measurements we used a recently developed experimental technique for measuring dissociation product distributions that allows both the branching ratios to be accurately determined and the electronic and rovibrational state composition of the reactant ions to be specified. DR is the dominant electron loss mechanism in all regions of the ionosphere. In this process, electron attachment to the molecular ion produces an unstable neutral molecule that rapidly dissociates. For a molecular ion such as O2(+), the dissociation recombination reaction is (1) O2(+) + e yields O + O + W. The atomic products of this reaction, in this case two oxygen atoms, can be produced in a variety of excited states and with a variety of kinetic energies, as represented by W in Eq. (1). These atoms are not only active in the neutral chemistry of the ionosphere, but are also especially important because their optical emissions are often used to infer in situ concentrations of the parent molecular ion and ambient electron densities. Many laboratory measurements have been made of DR reaction rates under a wide range of electron temperatures, but very little is known about the actual distributions among the final states of the atomic products. This lack of knowledge seriously limits the validity and effectiveness of efforts to model both natural and man-made ionospheric disturbances. Bates recently identified major deficiencies in the currently accepted branching ratios for O2(+) as they relate to blue and green line emission measurements in the nocturnal F-region. During our two-year effort, we partially satisfied our ambitious goals. We constructed and operated a variable pressure, electron-impact ion source and a high pressure, hollow-cathode discharge ion

  6. Antagonistic experimental coevolution with a parasite increases host recombination frequency

    Directory of Open Access Journals (Sweden)

    Kerstes Niels AG

    2012-02-01

    Full Text Available Abstract Background One of the big remaining challenges in evolutionary biology is to understand the evolution and maintenance of meiotic recombination. As recombination breaks down successful genotypes, it should be selected for only under very limited conditions. Yet, recombination is very common and phylogenetically widespread. The Red Queen Hypothesis is one of the most prominent hypotheses for the adaptive value of recombination and sexual reproduction. The Red Queen Hypothesis predicts an advantage of recombination for hosts that are coevolving with their parasites. We tested predictions of the hypothesis with experimental coevolution using the red flour beetle, Tribolium castaneum, and its microsporidian parasite, Nosema whitei. Results By measuring recombination directly in the individuals under selection, we found that recombination in the host population was increased after 11 generations of coevolution. Detailed insights into genotypic and phenotypic changes occurring during the coevolution experiment furthermore helped us to reconstruct the coevolutionary dynamics that were associated with this increase in recombination frequency. As coevolved lines maintained higher genetic diversity than control lines, and because there was no evidence for heterozygote advantage or for a plastic response of recombination to infection, the observed increase in recombination most likely represented an adaptive host response under Red Queen dynamics. Conclusions This study provides direct, experimental evidence for an increase in recombination frequency under host-parasite coevolution in an obligatory outcrossing species. Combined with earlier results, the Red Queen process is the most likely explanation for this observation.

  7. Monitoring homologous recombination in rice (Oryza sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Yang Zhuanying; Tang Li [Guangdong Provincial Key Lab of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631 (China); Li Meiru [South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650 (China); Chen Lei; Xu Jie [Guangdong Provincial Key Lab of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631 (China); Wu Goujiang [South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650 (China); Li Hongqing, E-mail: hqli@scnu.edu.cn [Guangdong Provincial Key Lab of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631 (China)

    2010-09-10

    Here we describe a system to assay homologous recombination during the complete life cycle of rice (Oryza sativa L.). Rice plants were transformed with two copies of non-functional GUS reporter overlap fragments as recombination substrate. Recombination was observed in all plant organs examined, from the seed stage until the flowering stage of somatic plant development. Embryogenic cells exhibited the highest recombination ability with an average of 3 x 10{sup -5} recombination events per genome, which is about 10-fold of that observed in root cells, and two orders of that observed in leaf cells. Histological analysis revealed that recombination events occurred in diverse cell types, but preferentially in cells with small size. Examples of this included embryogenic cells in callus, phloem cells in the leaf vein, and cells located in the root apical meristem. Steady state RNA analysis revealed that the expression levels of rice Rad51 homologs are positively correlated with increased recombination rates in embryogenic calli, roots and anthers. Finally, radiation treatment of plantlets from distinct recombination lines increased the recombination frequency to different extents. These results showed that homologous recombination frequency can be effectively measured in rice using a transgene reporter assay. This system will facilitate the study of DNA damage signaling and homologous recombination in rice, a model monocot.

  8. Characterization of the Key Aroma Compounds in Chinese Vidal Icewine by Gas Chromatography-Olfactometry, Quantitative Measurements, Aroma Recombination, and Omission Tests.

    Science.gov (United States)

    Ma, Yue; Tang, Ke; Xu, Yan; Li, Ji-Ming

    2017-01-18

    The key aroma compounds of Chinese Vidal icewine were characterized by means of gas chromatography-olfactometry (GC-O) coupled with mass spectrometry (MS) on polar and nonpolar columns, and their flavor dilution (FD) factors were determined by aroma extract dilution analysis (AEDA). A total of 59 odor-active aroma compounds in three ranks of Vidal icewines were identified, and 28 odorants (FD ≥ 9) were further quantitated for aroma reconstitution and omission tests. β-Damascenone showed the highest FD value of 2187 in all icewines. Methional and furaneol were first observed as important odorants in Vidal icewine. Aroma recombination experiments revealed a good similarity containing the 28 important aromas. Omission tests corroborated the significant contribution of β-damascenone and the entire group of esters. Besides, 4-hydroxy-2,5-dimethyl-3(2H)-furanone (furaneol) and 3-(methylthio)-1-propanal (methional) also had significant effects on icewine character, especially on apricot, caramel, and tropical fruit characteristics.

  9. Bioenergetics of the calf muscle in Friedreich ataxia patients measured by 31P-MRS before and after treatment with recombinant human erythropoietin.

    Directory of Open Access Journals (Sweden)

    Wolfgang Nachbauer

    Full Text Available Friedreich ataxia (FRDA is caused by a GAA repeat expansion in the FXN gene leading to reduced expression of the mitochondrial protein frataxin. Recombinant human erythropoietin (rhuEPO is suggested to increase frataxin levels, alter mitochondrial function and improve clinical scores in FRDA patients. Aim of the present pilot study was to investigate mitochondrial metabolism of skeletal muscle tissue in FRDA patients and examine effects of rhuEPO administration by phosphorus 31 magnetic resonance spectroscopy (31P MRS. Seven genetically confirmed FRDA patients underwent 31P MRS of the calf muscles using a rest-exercise-recovery protocol before and after receiving 3000 IU of rhuEPO for eight weeks. FRDA patients showed more rapid phosphocreatine (PCr depletion and increased accumulation of inorganic phosphate (Pi during incremental exercise as compared to controls. After maximal exhaustive exercise prolonged regeneration of PCR and slowed decline in Pi can be seen in FRDA. PCr regeneration as hallmark of mitochondrial ATP production revealed correlation to activity of complex II/III of the respiratory chain and to demographic values. PCr and Pi kinetics were not influenced by rhuEPO administration. Our results confirm mitochondrial dysfunction and exercise intolerance due to impaired oxidative phosphorylation in skeletal muscle tissue of FRDA patients. MRS did not show improved mitochondrial bioenergetics after eight weeks of rhuEPO exposition in skeletal muscle tissue of FRDA patients.EU Clinical Trials Register2008-000040-13.

  10. Gateway Recombinational Cloning.

    Science.gov (United States)

    Reece-Hoyes, John S; Walhout, Albertha J M

    2018-01-02

    The Gateway recombinatorial cloning system was developed for cloning multiple DNA fragments in parallel (e.g., in 96-well formats) in a standardized manner using the same enzymes. Gateway cloning is based on the highly specific integration and excision reactions of bacteriophage λ into and out of the Escherichia coli genome. Because the sites of recombination (" att " sites) are much longer (25-242 bp) than restriction sites, they are extremely unlikely to occur by chance in DNA fragments. Therefore, the same recombination enzyme can be used to robustly clone many different fragments of variable size in parallel reactions. © 2018 Cold Spring Harbor Laboratory Press.

  11. Recombination and chiasmata: few but intriguing discrepancies.

    Science.gov (United States)

    Sybenga, J

    1996-06-01

    The paradigm that meiotic recombination and chiasmata have the same basis has been challenged, primarily for plants. High resolution genetic mapping frequently results in maps with lengths far exceeding those based on chiasma counts. In addition, recombination between specific homoeologous chromosomes derived from interspecific hybrids is sometimes much higher than can be explained by meiotic chiasma frequencies. However, almost the entire discrepancy disappears when proper care is taken of map inflation resulting from the shortcomings of the mapping algorithm and classification errors, the use of dissimilar material, and the difficulty of accurately counting chiasmata. Still, some exchanges, especially of short interstitial segments, cannot readily be explained by normal meiotic behaviour. Aberrant meiotic processes involving segment replacement or insertion can probably be excluded. Some cases of unusual recombination are somatic, possibly premeiotic exchange. For other cases, local relaxation of chiasma interference caused by small interruptions of homology disturbing synaptonemal complex formation is proposed as the cause. It would be accompanied by a preference for compensating exchanges (negative chromatid interference) resulting from asymmetry of the pairing chromatid pairs, so that one side of each pair preferentially participates in pairing. Over longer distances, the pairing face may switch, causing the normal random chromatid participation in double exchanges and the relatively low frequency of short interstitial exchanges. Key words : recombination frequency, map length, chiasmata, discrepancy, chromatid interference.

  12. Meiotic versus Mitotic Recombination: Two Different Routes for Double-Strand Break Repair

    Science.gov (United States)

    Andersen, Sabrina L.; Sekelsky, Jeff

    2011-01-01

    Summary Studies in the yeast Saccharomyces cerevisiae have validated the major features of the double-strand break repair (DSBR) model as an accurate representation of the pathway through which meiotic crossovers are produced. This success has led to this model being invoked to explain double-strand break (DSB) repair in other contexts. However, most non-crossover recombinants generated during S. cerevisiae meiosis do not arise via a DSBR pathway. Furthermore, and it is becoming increasing clear that DSBR is a minor pathway for recombinational repair of DSBs that occur in mitotically proliferating cells; rather, the synthesis-dependent strand annealing (SDSA) model appears to describe mitotic DSB repair more accurately. Fundamental dissimilarities between meiotic and mitotic recombination are not unexpected, since meiotic recombination serves a very different purpose (accurate chromosome segregation, which requires crossovers) than mitotic recombination (repair of DNA damage, which typically generates non-crossovers). PMID:20967781

  13. Charge Recombination Suppressed by Destructive Quantum Interference in Heterojunction Materials.

    Science.gov (United States)

    Tempelaar, Roel; Koster, L Jan Anton; Havenith, Remco W A; Knoester, Jasper; Jansen, Thomas L C

    2016-01-07

    We show that charge recombination in ordered heterojunctions depends sensitively on the degree of coherent delocalization of charges at the donor-acceptor interface. Depending on the relative sign of the electron and hole transfer integrals, such delocalization can dramatically suppress recombination through destructive quantum interference. This could explain why measured recombination rates are significantly lower than predictions based on Langevin theory for a variety of organic bulk heterojunctions. Moreover, it opens up a design strategy for photovoltaic devices with enhanced efficiencies through coherently suppressed charge recombination.

  14. Heterogeneous recombination among Hepatitis B virus genotypes.

    Science.gov (United States)

    Castelhano, Nadine; Araujo, Natalia M; Arenas, Miguel

    2017-10-01

    The rapid evolution of Hepatitis B virus (HBV) through both evolutionary forces, mutation and recombination, allows this virus to generate a large variety of adapted variants at both intra and inter-host levels. It can, for instance, generate drug resistance or the diverse viral genotypes that currently exist in the HBV epidemics. Concerning the latter, it is known that recombination played a major role in the emergence and genetic diversification of novel genotypes. In this regard, the quantification of viral recombination in each genotype can provide relevant information to devise expectations about the evolutionary trends of the epidemic. Here we measured the amount of this evolutionary force by estimating global and local recombination rates in >4700 HBV complete genome sequences corresponding to nine (A to I) HBV genotypes. Counterintuitively, we found that genotype E presents extremely high levels of recombination, followed by genotypes B and C. On the other hand, genotype G presents the lowest level, where recombination is almost negligible. We discuss these findings in the light of known characteristics of these genotypes. Additionally, we present a phylogenetic network to depict the evolutionary history of the studied HBV genotypes. This network clearly classified all genotypes into specific groups and indicated that diverse pairs of genotypes are derived from a common ancestor (i.e., C-I, D-E and, F-H) although still the origin of this virus presented large uncertainty. Altogether we conclude that the amount of observed recombination is heterogeneous among HBV genotypes and that this heterogeneity can influence on the future expansion of the epidemic. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. NNLOPS accurate associated HW production

    CERN Document Server

    Astill, William; Re, Emanuele; Zanderighi, Giulia

    2016-01-01

    We present a next-to-next-to-leading order accurate description of associated HW production consistently matched to a parton shower. The method is based on reweighting events obtained with the HW plus one jet NLO accurate calculation implemented in POWHEG, extended with the MiNLO procedure, to reproduce NNLO accurate Born distributions. Since the Born kinematics is more complex than the cases treated before, we use a parametrization of the Collins-Soper angles to reduce the number of variables required for the reweighting. We present phenomenological results at 13 TeV, with cuts suggested by the Higgs Cross Section Working Group.

  16. Efficient Inference of Recent and Ancestral Recombination within Bacterial Populations.

    Science.gov (United States)

    Mostowy, Rafal; Croucher, Nicholas J; Andam, Cheryl P; Corander, Jukka; Hanage, William P; Marttinen, Pekka

    2017-05-01

    Prokaryotic evolution is affected by horizontal transfer of genetic material through recombination. Inference of an evolutionary tree of bacteria thus relies on accurate identification of the population genetic structure and recombination-derived mosaicism. Rapidly growing databases represent a challenge for computational methods to detect recombinations in bacterial genomes. We introduce a novel algorithm called fastGEAR which identifies lineages in diverse microbial alignments, and recombinations between them and from external origins. The algorithm detects both recent recombinations (affecting a few isolates) and ancestral recombinations between detected lineages (affecting entire lineages), thus providing insight into recombinations affecting deep branches of the phylogenetic tree. In simulations, fastGEAR had comparable power to detect recent recombinations and outstanding power to detect the ancestral ones, compared with state-of-the-art methods, often with a fraction of computational cost. We demonstrate the utility of the method by analyzing a collection of 616 whole-genomes of a recombinogenic pathogen Streptococcus pneumoniae, for which the method provided a high-resolution view of recombination across the genome. We examined in detail the penicillin-binding genes across the Streptococcus genus, demonstrating previously undetected genetic exchanges between different species at these three loci. Hence, fastGEAR can be readily applied to investigate mosaicism in bacterial genes across multiple species. Finally, fastGEAR correctly identified many known recombination hotspots and pointed to potential new ones. Matlab code and Linux/Windows executables are available at https://users.ics.aalto.fi/~pemartti/fastGEAR/ (last accessed February 6, 2017). © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  17. Photoionization and electron-ion recombination of P II

    Science.gov (United States)

    Nahar, Sultana N.

    2017-08-01

    A study of the inverse processes of photoionization and electron-ion recombination of P II is reported. Phosphorus, a little studied cosmic element, requires atomic parameters such as those presented here for spectral analysis. The unified method of Nahar and Pradhan, which incorporates two methods of recombination - radiative recombination (RR) and dielectronic recombination (DR) - and the interference between them, is used to obtain the total electron-ion recombination. This method implements the framework of the {R}-matrix close-coupling approximation. The present results include the partial photoionization cross-sections σPI(Jπ) leaving the residual ion in the ground level and level-specific recombination rate coefficients, αRC(Jπ), of 475 fine-structure levels of P II with n ≤10. In photoionization of the ground and many excited levels, a sharp resonance is found to form at the ionization threshold from couplings of relativistic fine-structure channels. These, with other resonances in the near-threshold energy region, yield a slight curvature, in contrast to typical smooth decay, at a very low temperature of about 330 K in the total recombination rate coefficient αRC. The presence of other Rydberg and Seaton resonances in the photoionization cross-section introduces features in the level-specific recombination rate coefficients and a DR bump at high temperature at 105 K for the total recombination rate coefficient. Considerable interference between RR and DR is noted around 6700 K. The recombination spectrum with respect to photoelectron energy αRC(E) is also presented. The results are expected to provide accurate models for astrophysical plasmas up to ˜1 MK.

  18. Trap-assisted recombination in disordered organic semiconductors

    NARCIS (Netherlands)

    Kuik, M.; Koster, L.J.A.; Wetzelaer, G.A.H.; Blom, P.W.M.

    2011-01-01

    The trap-assisted recombination of electrons and holes in organic semiconductors is investigated. The extracted capture coefficients of the trap-assisted recombination process are thermally activated with an identical activation energy as measured for the hole mobility μp. We demonstrate that the

  19. Biophysical characterisation of GlycoPEGylated recombinant human factor VIIa

    DEFF Research Database (Denmark)

    Plesner, Bitten; Westh, Peter; Nielsen, Anders D.

    2011-01-01

    The effects of GlycoPEGylation on the structural, kinetic and thermal stability of recombinant human FVIIa were investigated using rFVIIa and linear 10 kDa and branched 40 kDa GlycoPEGylated® recombinant human FVIIa derivatives. The secondary and tertiary structure of rFVIIa measured by circular...

  20. Comparison of the Genetic Recombination Rates of Human Immunodeficiency Virus Type 1 in Macrophages and T Cells†

    OpenAIRE

    Chen, Jianbo; Rhodes, Terence D.; Hu, Wei-Shau

    2005-01-01

    Human immunodeficiency virus type 1 (HIV-1) exhibits a high level of genetic variation generated by frequent mutation and genetic recombination during reverse transcription. We have measured HIV-1 recombination rates in T cells in one round of virus replication. It was recently proposed that HIV-1 recombines far more frequently in macrophages than in T cells. In an attempt to delineate the mechanisms that elevate recombination, we measured HIV-1 recombination rates in macrophages at three dif...

  1. Site directed recombination

    Science.gov (United States)

    Jurka, Jerzy W.

    1997-01-01

    Enhanced homologous recombination is obtained by employing a consensus sequence which has been found to be associated with integration of repeat sequences, such as Alu and ID. The consensus sequence or sequence having a single transition mutation determines one site of a double break which allows for high efficiency of integration at the site. By introducing single or double stranded DNA having the consensus sequence flanking region joined to a sequence of interest, one can reproducibly direct integration of the sequence of interest at one or a limited number of sites. In this way, specific sites can be identified and homologous recombination achieved at the site by employing a second flanking sequence associated with a sequence proximal to the 3'-nick.

  2. Nonradiative recombination in semiconductors

    CERN Document Server

    Abakumov, VN; Yassievich, IN

    1991-01-01

    In recent years, great progress has been made in the understandingof recombination processes controlling the number of excessfree carriers in semiconductors under nonequilibrium conditions. As a result, it is now possible to give a comprehensivetheoretical description of these processes. The authors haveselected a number of experimental results which elucidate theunderlying physical problems and enable a test of theoreticalmodels. The following topics are dealt with: phenomenological theory ofrecombination, theoretical models of shallow and deep localizedstates, cascade model of carrier captu

  3. More Accurate Definition of Clinical Target Volume Based on the Measurement of Microscopic Extensions of the Primary Tumor Toward the Uterus Body in International Federation of Gynecology and Obstetrics Ib-IIa Squamous Cell Carcinoma of the Cervix

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wen-Jia [Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong Province (China); Wu, Xiao [Department of Pathology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong Province (China); Xue, Ren-Liang; Lin, Xiang-Ying [Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong Province (China); Kidd, Elizabeth A. [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Yan, Shu-Mei [Department of Pathology, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong Province (China); Zhang, Yao-Hong [Department of Radiation Oncology, Chaozhou Hospital of Chaozhou City, Guangdong Province (China); Zhai, Tian-Tian; Lu, Jia-Yang; Wu, Li-Li; Zhang, Hao [Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong Province (China); Huang, Hai-Hua [Department of Pathology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong Province (China); Chen, Zhi-Jian; Li, De-Rui [Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong Province (China); Xie, Liang-Xi, E-mail: xieliangxi1@qq.com [Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong Province (China)

    2015-01-01

    Purpose: To more accurately define clinical target volume for cervical cancer radiation treatment planning by evaluating tumor microscopic extension toward the uterus body (METU) in International Federation of Gynecology and Obstetrics stage Ib-IIa squamous cell carcinoma of the cervix (SCCC). Patients and Methods: In this multicenter study, surgical resection specimens from 318 cases of stage Ib-IIa SCCC that underwent radical hysterectomy were included. Patients who had undergone preoperative chemotherapy, radiation, or both were excluded from this study. Microscopic extension of primary tumor toward the uterus body was measured. The association between other pathologic factors and METU was analyzed. Results: Microscopic extension toward the uterus body was not common, with only 12.3% of patients (39 of 318) demonstrating METU. The mean (±SD) distance of METU was 0.32 ± 1.079 mm (range, 0-10 mm). Lymphovascular space invasion was associated with METU distance and occurrence rate. A margin of 5 mm added to gross tumor would adequately cover 99.4% and 99% of the METU in the whole group and in patients with lymphovascular space invasion, respectively. Conclusion: According to our analysis of 318 SCCC specimens for METU, using a 5-mm gross tumor volume to clinical target volume margin in the direction of the uterus should be adequate for International Federation of Gynecology and Obstetrics stage Ib-IIa SCCC. Considering the discrepancy between imaging and pathologic methods in determining gross tumor volume extent, we recommend a safer 10-mm margin in the uterine direction as the standard for clinical practice when using MRI for contouring tumor volume.

  4. Analysis of accurate 13C and 18O isotope measurements of CO2 in CARIBIC aircraft air samples from the tropical troposphere, and the upper troposphere/lowermost stratosphere

    Science.gov (United States)

    Assonov, S. S.; Brenninkmeijer, C. A. M.; Schuck, T. J.; Taylor, P.

    2010-03-01

    The project CARIBIC (http://caribic-atmospheric.com) aims to study atmospheric chemistry and transport by regularly measuring many compounds in the free troposphere (FT) and the upper troposphere/lowermost stratosphere (UT/LMS) by using passenger aircraft. Here CO2 concentrations and highly accurate isotope results are presented in detail together with supporting trace gas data. 509 CARIBIC-2 samples (highest precision and accuracy δ13C(CO2) and δ18O(CO2) data) from June 2007 until March 2009, together with CARIBIC-1 samples (flights between November 1999 and April 2002, 350 samples in total, 270 for NH, mostly δ13C(CO2) data) give a fairly extensive, unique data set for the NH free troposphere and the UT/LMS region. To compare data from different years a de-trending is applied. In the UT/LMS region δ13C(CO2), δ18O(CO2) and CO2 are found to correlate well with stratospheric tracers, in particular N2O. These correlations are in good agreement with current understanding of stratospheric circulation. δ18O(CO2) appears to be a useful, hitherto unused, tracer of atmospheric transport in the UT/LMS region. By filtering out the LMS data (based on N2O distribution), the isotope variations for the free and upper troposphere are obtained. These show however little latitudinal gradient, if any, and are in good agreement with the data of selected NOAA stations in NH tropics. Correlations between δ13C(CO2) and CO2 are observed both within single flight(s) covering long distances and for certain seasons. The overall variability in de-trended δ13C(CO2) and CO2 for CARIBIC-1 and CARIBIC-2 are similar and basically agree with each other, which also underscores the high quality of measurement. Based on all correlations, we discuss that CO2 distribution in the NH FT and UT (at CARIBIC flight routes) is regulated by uplift and pole-wards transport of tropical air up to approximately 50° N. The main reasons for variability of signals in FT and UT (which is larger for the high

  5. Bacterial Recombineering: Genome Engineering via Phage-Based Homologous Recombination.

    Science.gov (United States)

    Pines, Gur; Freed, Emily F; Winkler, James D; Gill, Ryan T

    2015-11-20

    The ability to specifically modify bacterial genomes in a precise and efficient manner is highly desired in various fields, ranging from molecular genetics to metabolic engineering and synthetic biology. Much has changed from the initial realization that phage-derived genes may be employed for such tasks to today, where recombineering enables complex genetic edits within a genome or a population. Here, we review the major developments leading to recombineering becoming the method of choice for in situ bacterial genome editing while highlighting the various applications of recombineering in pushing the boundaries of synthetic biology. We also present the current understanding of the mechanism of recombineering. Finally, we discuss in detail issues surrounding recombineering efficiency and future directions for recombineering-based genome editing.

  6. A double epitope tag for quantification of recombinant protein using fluorescence resonance energy transfer.

    Science.gov (United States)

    Enomoto, Koji; Uwabe, Ken-Ichiro; Naito, Shoichi; Onoda, Jyunji; Yamauchi, Akira; Numata, Yoshito; Takemoto, Hiroshi

    2008-09-15

    The expression of recombinant proteins is a well-accepted technology, but their detection and purification often require time-consuming and complicated processes. This paper describes the development of a novel double epitope tag (GEPGDDGPSGAEGPPGPQG) for rapid and accurate quantification of recombinant protein by a homogeneous immunoassay based on fluorescence resonance energy transfer. In our double epitope tagging system, recombinant proteins can be simply measured on a microtiter plate by addition of a pair of fluorophore-labeled monoclonal antibodies (their epitopes; GEPGDDGPS and GPPGPQG). The sensitivity of the immunoassay with an incubation time of only 5 min is almost equal to that of labor-intensive Western blotting. In addition, culture media and extracts of host cells generally used for protein expression have little effect on this immunoassay. To investigate the utility of our proposed tag for protein production, several different proteins containing this tag were practically expressed and purified. The data presented demonstrate that the double epitope tag is a reliable tool that can alleviate the laborious and troublesome processes of protein production.

  7. Rapid monitoring of recombinant antibody production by mammalian cell cultures using fourier transform infrared spectroscopy and chemometrics.

    Science.gov (United States)

    Sellick, Christopher A; Hansen, Rasmus; Jarvis, Roger M; Maqsood, Arfa R; Stephens, Gill M; Dickson, Alan J; Goodacre, Royston

    2010-06-15

    Fourier transform infrared (FT-IR) spectroscopy combined with multivariate statistical analyses was investigated as a physicochemical tool for monitoring secreted recombinant antibody production in cultures of Chinese hamster ovary (CHO) and murine myeloma non-secreting 0 (NS0) cell lines. Medium samples were taken during culture of CHO and NS0 cells lines, which included both antibody-producing and non-producing cell lines, and analyzed by FT-IR spectroscopy. Principal components analysis (PCA) alone, and combined with discriminant function analysis (PC-DFA), were applied to normalized FT-IR spectroscopy datasets and showed a linear trend with respect to recombinant protein production. Loadings plots of the most significant spectral components showed a decrease in the C-O stretch from polysaccharides and an increase in the amide I band during culture, respectively, indicating a decrease in sugar concentration and an increase in protein concentration in the medium. Partial least squares regression (PLSR) analysis was used to predict antibody titers, and these regression models were able to predict antibody titers accurately with low error when compared to ELISA data. PLSR was also able to predict glucose and lactate amounts in the medium samples accurately. This work demonstrates that FT-IR spectroscopy has great potential as a tool for monitoring cell cultures for recombinant protein production and offers a starting point for the application of spectroscopic techniques for the on-line measurement of antibody production in industrial scale bioreactors. 2010 Wiley Periodicals, Inc.

  8. Expression of recombinant Antibodies

    Directory of Open Access Journals (Sweden)

    André eFrenzel

    2013-07-01

    Full Text Available Recombinant antibodies are highly specific detection probes in research, diagnostics and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transgenic plants and animals. Currently, almost all therapeutic antibodies are still produced in mammalian cell lines in order to reduce the risk of immunogenicity due to altered, non-human glycosylation patterns. However, recent developments of glycosylation-engineered yeast, insect cell lines and transgenic plants are promising to obtain antibodies with human-like post-translational modifications. Furthermore, smaller antibody fragments including bispecific antibodies without any glycosylation are successfully produced in bacteria and have advanced to clinical testing. The first therapeutic antibody products from a non-mammalian source can be expected in coming next years. In this review, we focus on current antibody production systems including their usability for different applications.

  9. Expression of Recombinant Antibodies

    Science.gov (United States)

    Frenzel, André; Hust, Michael; Schirrmann, Thomas

    2013-01-01

    Recombinant antibodies are highly specific detection probes in research, diagnostics, and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transgenic plants and animals. Currently, almost all therapeutic antibodies are still produced in mammalian cell lines in order to reduce the risk of immunogenicity due to altered, non-human glycosylation patterns. However, recent developments of glycosylation-engineered yeast, insect cell lines, and transgenic plants are promising to obtain antibodies with “human-like” post-translational modifications. Furthermore, smaller antibody fragments including bispecific antibodies without any glycosylation are successfully produced in bacteria and have advanced to clinical testing. The first therapeutic antibody products from a non-mammalian source can be expected in coming next years. In this review, we focus on current antibody production systems including their usability for different applications. PMID:23908655

  10. A theoretical study of the dissociative recombination of SH+ with electrons through the 2Π states of SH.

    Science.gov (United States)

    Kashinski, D O; Talbi, D; Hickman, A P; Di Nallo, O E; Colboc, F; Chakrabarti, K; Schneider, I F; Mezei, J Zs

    2017-05-28

    A quantitative theoretical study of the dissociative recombination of SH+ with electrons has been carried out. Multireference, configuration interaction calculations were used to determine accurate potential energy curves for SH+ and SH. The block diagonalization method was used to disentangle strongly interacting SH valence and Rydberg states and to construct a diabatic Hamiltonian whose diagonal matrix elements provide the diabatic potential energy curves. The off-diagonal elements are related to the electronic valence-Rydberg couplings. Cross sections and rate coefficients for the dissociative recombination reaction were calculated with a stepwise version of the multichannel quantum defect theory, using the molecular data provided by the block diagonalization method. The calculated rates are compared with the most recent measurements performed on the ion Test Storage Ring (TSR) in Heidelberg, Germany.

  11. A high etendue spectrometer suitable for core charge eXchange recombination spectroscopy on ITER

    Energy Technology Data Exchange (ETDEWEB)

    Jaspers, R. J. E.; Scheffer, M. [Science and Technology of Nuclear Fusion, Eindhoven University of Technology, Eindhoven (Netherlands); Kappatou, A. [FOM Institute DIFFER - Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM, Nieuwegein (Netherlands); Valk, N. C. J. van der; Durkut, M.; Snijders, B. [TNO Science and Industry, P.O. Box 155, 2600 AD Delft (Netherlands); Marchuk, O.; Biel, W. [Institut fuer Energie und Klimaforschung-IEK-4 Forschungszentrum, Juelich GmbH, 52425 Juelich (Germany); Pokol, G. I. [Institute of Nuclear Techniques, Budapest University of Technology and Economics, EURATOM Association, P. O. Box 91, H-1521 Budapest (Hungary); Erdei, G. [Department of Atomic Physics, Budapest University of Technology and Economics, EURATOM Association, P. O. Box 91, H-1521 Budapest (Hungary); Zoletnik, S.; Dunai, D. [WIGNER RCP, RMKI, EURATOM Association, P. O. Box 91, H-1521 Budapest (Hungary)

    2012-10-15

    A feasibility study for the use of core charge exchange recombination spectroscopy on ITER has shown that accurate measurements on the helium ash require a spectrometer with a high etendue of 1mm{sup 2}sr to comply with the measurement requirements [S. Tugarinov et al., Rev. Sci. Instrum. 74, 2075 (2003)]. To this purpose such an instrument has been developed consisting of three separate wavelength channels (to measure simultaneously He/Be, C/Ne, and H/D/T together with the Doppler shifted direct emission of the diagnostic neutral beam, the beam emission (BES) signal), combining high dispersion (0.02 nm/pixel), sufficient resolution (0.2 nm), high efficiency (55%), and extended wavelength range (14 nm) at high etendue. The combined measurement of the BES along the same sightline within a third wavelength range provides the possibility for in situ calibration of the charge eXchange recombination spectroscopy signals. In addition, the option is included to use the same instrument for measurements of the fast fluctuations of the beam emission intensity up to 2 MHz, with the aim to study MHD activity.

  12. A high etendue spectrometer suitable for core charge eXchange recombination spectroscopy on ITERa)

    Science.gov (United States)

    Jaspers, R. J. E.; Scheffer, M.; Kappatou, A.; van der Valk, N. C. J.; Durkut, M.; Snijders, B.; Marchuk, O.; Biel, W.; Pokol, G. I.; Erdei, G.; Zoletnik, S.; Dunai, D.

    2012-10-01

    A feasibility study for the use of core charge exchange recombination spectroscopy on ITER has shown that accurate measurements on the helium ash require a spectrometer with a high etendue of 1mm2sr to comply with the measurement requirements [S. Tugarinov et al., Rev. Sci. Instrum. 74, 2075 (2003)], 10.1063/1.1537443. To this purpose such an instrument has been developed consisting of three separate wavelength channels (to measure simultaneously He/Be, C/Ne, and H/D/T together with the Doppler shifted direct emission of the diagnostic neutral beam, the beam emission (BES) signal), combining high dispersion (0.02 nm/pixel), sufficient resolution (0.2 nm), high efficiency (55%), and extended wavelength range (14 nm) at high etendue. The combined measurement of the BES along the same sightline within a third wavelength range provides the possibility for in situ calibration of the charge eXchange recombination spectroscopy signals. In addition, the option is included to use the same instrument for measurements of the fast fluctuations of the beam emission intensity up to 2 MHz, with the aim to study MHD activity.

  13. Microbial factories for recombinant pharmaceuticals

    National Research Council Canada - National Science Library

    Ferrer-Miralles, Neus; Domingo-Espín, Joan; Corchero, José Luis; Vázquez, Esther; Villaverde, Antonio

    2009-01-01

    ...-translational modifications, proteolytic instability, poor solubility and activation of cell stress responses, among others, they represent convenient and powerful tools for recombinant protein production...

  14. Sex recombination, and reproductive fitness: an experimental study using Paramecium

    Energy Technology Data Exchange (ETDEWEB)

    Nyberg, D.

    1982-08-01

    The effect of sex and recombination on reproductive fitness are measured using five wild stocks of Paramecium primaurelia. Among the wild stocks there were highly significant differences in growth rates. No hybrid had as low a fitness as the least fit parental stock. Recombination produced genotypes of higher fitness than those of either parent only in the cross between the two stocks of lowest fitness. The increase in variance of fitness as a result of recombination was almost exclusively attributable to the generation lines with low fitness. The fitness consequences of sexuality and mate choice were stock specific; some individuals leaving the most descendants by inbreeding, others by outcrossing. For most crosses the short-term advantage of sex, if any, accrue from the fusion of different gametes (hybrid vigor) and not from recombination. Since the homozygous genotype with the highest fitnes left the most progeny by inbreeding (no recombination), the persistence of conjugation in P. primaurelia is paradoxical. (JMT)

  15. Distribution of meiotic recombination events: Talking to your neighbors

    Science.gov (United States)

    Martinez-Perez, Enrique; Colaiácovo, Monica P.

    2009-01-01

    Accurate chromosome segregation during meiosis is essential for a species' survival. Therefore, a series of events unfold during meiosis, including pairing, synapsis and recombination between homologous chromosomes, to ultimately ensure the successful completion of this task. This review will focus on how the regulation of crossover recombination events between homologous chromosomes plays a key role in promoting faithful segregation. Although our understanding of the molecular mechanisms by which crossovers are formed has increased significantly, the mechanisms governing the distribution of crossovers along meiotic chromosomes remain largely mysterious. Here, we review the different levels of apparent control of meiotic crossover formation and distribution. PMID:19328674

  16. Dynamics of HIV-1 recombination in its natural target cells.

    Science.gov (United States)

    Levy, David N; Aldrovandi, Grace M; Kutsch, Olaf; Shaw, George M

    2004-03-23

    Genetic recombination is believed to assist HIV-1 diversification and escape from host immunity and antiviral therapies, yet this process remains largely unexamined within the natural target-cell populations. We developed a method for measuring HIV-1 recombination directly that employs reporter viruses bearing functional enhanced yellow fluorescent protein (YFP) and enhanced cyan fluorescent protein (CFP) genes in which recombination produces a modified GFP gene and GFP fluorescence in the infected cells. These reporter viruses allow simultaneous quantification of the dynamics of HIV-1 infection, coinfection, and recombination in cell culture and in animal models by flow-cytometric analysis. Multiround infection assays revealed that productive cellular coinfection was subject to little functional inhibition. As a result, generation of recombinants proceeded according to the square of the infection rate during HIV-1 replication in T lymphocytes and within human thymic grafts in severe combined immunodeficient (SCID)-hu (Thy/Liv) mice. These results suggest that increases in viral load may confer a compounding risk of virus escape by means of recombinational diversification. A single round of replication in T lymphocytes in culture generated an average of nine recombination events per virus, and infection of macrophages led to approximately 30 crossover events, making HIV-1 up to an order of magnitude more recombinogenic than recognized previously and demonstrating that the infected cell exerts a profound influence on the frequency of recombination.

  17. When Is Network Lasso Accurate?

    Directory of Open Access Journals (Sweden)

    Alexander Jung

    2018-01-01

    Full Text Available The “least absolute shrinkage and selection operator” (Lasso method has been adapted recently for network-structured datasets. In particular, this network Lasso method allows to learn graph signals from a small number of noisy signal samples by using the total variation of a graph signal for regularization. While efficient and scalable implementations of the network Lasso are available, only little is known about the conditions on the underlying network structure which ensure network Lasso to be accurate. By leveraging concepts of compressed sensing, we address this gap and derive precise conditions on the underlying network topology and sampling set which guarantee the network Lasso for a particular loss function to deliver an accurate estimate of the entire underlying graph signal. We also quantify the error incurred by network Lasso in terms of two constants which reflect the connectivity of the sampled nodes.

  18. Accurate Accident Reconstruction in VANET

    OpenAIRE

    Kopylova, Yuliya; Farkas, Csilla; Xu, Wenyuan

    2011-01-01

    Part 9: Short Papers; International audience; We propose a forensic VANET application to aid an accurate accident reconstruction. Our application provides a new source of objective real-time data impossible to collect using existing methods. By leveraging inter-vehicle communications, we compile digital evidence describing events before, during, and after an accident in its entirety. In addition to sensors data and major components’ status, we provide relative positions of all vehicles involv...

  19. Emergence of recombinant forms of HIV: dynamics and scaling.

    Directory of Open Access Journals (Sweden)

    Gajendra W Suryavanshi

    2007-10-01

    Full Text Available The ability to accelerate the accumulation of favorable combinations of mutations renders recombination a potent force underlying the emergence of forms of HIV that escape multi-drug therapy and specific host immune responses. We present a mathematical model that describes the dynamics of the emergence of recombinant forms of HIV following infection with diverse viral genomes. Mimicking recent in vitro experiments, we consider target cells simultaneously exposed to two distinct, homozygous viral populations and construct dynamical equations that predict the time evolution of populations of uninfected, singly infected, and doubly infected cells, and homozygous, heterozygous, and recombinant viruses. Model predictions capture several recent experimental observations quantitatively and provide insights into the role of recombination in HIV dynamics. From analyses of data from single-round infection experiments with our description of the probability with which recombination accumulates distinct mutations present on the two genomic strands in a virion, we estimate that approximately 8 recombinational strand transfer events occur on average (95% confidence interval: 6-10 during reverse transcription of HIV in T cells. Model predictions of virus and cell dynamics describe the time evolution and the relative prevalence of various infected cell subpopulations following the onset of infection observed experimentally. Remarkably, model predictions are in quantitative agreement with the experimental scaling relationship that the percentage of cells infected with recombinant genomes is proportional to the percentage of cells coinfected with the two genomes employed at the onset of infection. Our model thus presents an accurate description of the influence of recombination on HIV dynamics in vitro. When distinctions between different viral genomes are ignored, our model reduces to the standard model of viral dynamics, which successfully predicts viral load

  20. Accurate phase-shift velocimetry in rock.

    Science.gov (United States)

    Shukla, Matsyendra Nath; Vallatos, Antoine; Phoenix, Vernon R; Holmes, William M

    2016-06-01

    Spatially resolved Pulsed Field Gradient (PFG) velocimetry techniques can provide precious information concerning flow through opaque systems, including rocks. This velocimetry data is used to enhance flow models in a wide range of systems, from oil behaviour in reservoir rocks to contaminant transport in aquifers. Phase-shift velocimetry is the fastest way to produce velocity maps but critical issues have been reported when studying flow through rocks and porous media, leading to inaccurate results. Combining PFG measurements for flow through Bentheimer sandstone with simulations, we demonstrate that asymmetries in the molecular displacement distributions within each voxel are the main source of phase-shift velocimetry errors. We show that when flow-related average molecular displacements are negligible compared to self-diffusion ones, symmetric displacement distributions can be obtained while phase measurement noise is minimised. We elaborate a complete method for the production of accurate phase-shift velocimetry maps in rocks and low porosity media and demonstrate its validity for a range of flow rates. This development of accurate phase-shift velocimetry now enables more rapid and accurate velocity analysis, potentially helping to inform both industrial applications and theoretical models. Copyright © 2016. Published by Elsevier Inc.

  1. Accurate Calculation of Electric Fields Inside Enzymes.

    Science.gov (United States)

    Wang, X; He, X; Zhang, J Z H

    2016-01-01

    The specific electric field generated by a protease at its active site is considered as an important source of the catalytic power. Accurate calculation of electric field at the active site of an enzyme has both fundamental and practical importance. Measuring site-specific changes of electric field at internal sites of proteins due to, eg, mutation, has been realized by using molecular probes with CO or CN groups in the context of vibrational Stark effect. However, theoretical prediction of change in electric field inside a protein based on a conventional force field, such as AMBER or OPLS, is often inadequate. For such calculation, quantum chemical approach or quantum-based polarizable or polarized force field is highly preferable. Compared with the result from conventional force field, significant improvement is found in predicting experimentally measured mutation-induced electric field change using quantum-based methods, indicating that quantum effect such as polarization plays an important role in accurate description of electric field inside proteins. In comparison, the best theoretical prediction comes from fully quantum mechanical calculation in which both polarization and inter-residue charge transfer effects are included for accurate prediction of electrostatics in proteins. © 2016 Elsevier Inc. All rights reserved.

  2. Cell biology of mitotic recombination

    DEFF Research Database (Denmark)

    Lisby, Michael; Rothstein, Rodney

    2015-01-01

    Homologous recombination provides high-fidelity DNA repair throughout all domains of life. Live cell fluorescence microscopy offers the opportunity to image individual recombination events in real time providing insight into the in vivo biochemistry of the involved proteins and DNA molecules as w...

  3. An experiment to measure accurately the lifetime of the $D^{0}, D^{\\pm}, F^{\\pm}, \\Lambda_{c}$-charm particles and to study their hadronic production and decay properties

    CERN Multimedia

    2002-01-01

    We propose to use the EHS with the hydrogen bubble chamber HOLEBC equipped with classical optics to accumulate statistics of several hundred fully reconstructed $D^{0}$ and $D^{\\pm}$ and several tens of $F^{\\pm}$ and $\\Lambda_{c}$ decays produced by 360 GeV/c $\\pi^{-}$ and 360 GeV/c proton beams. The main aim of the experiment is to determine accurately the lifetime of these particles. Interesting information will also be obtained on branching ratios, decay modes and hadronic production mechanisms.

  4. A role for histone acetylation in the developmental regulation of VDJ recombination.

    Science.gov (United States)

    McMurry, M T; Krangel, M S

    2000-01-21

    VDJ recombination is developmentally regulated in vivo by enhancer-dependent changes in the accessibility of chromosomal recombination signal sequences to the recombinase, but the molecular nature of these changes is unknown. Here histone H3 acetylation was measured along versions of a transgenic VDJ recombination reporter and the endogenous T cell receptor alpha/delta locus. Enhancer activity was shown to impart long-range, developmentally regulated changes in H3 acetylation, and H3 acetylation status was tightly linked to VDJ recombination. H3 hyperacetylation is proposed as a molecular mechanism coupling enhancer activity to accessibility for VDJ recombination.

  5. The Accurate Particle Tracer Code

    CERN Document Server

    Wang, Yulei; Qin, Hong; Yu, Zhi

    2016-01-01

    The Accurate Particle Tracer (APT) code is designed for large-scale particle simulations on dynamical systems. Based on a large variety of advanced geometric algorithms, APT possesses long-term numerical accuracy and stability, which are critical for solving multi-scale and non-linear problems. Under the well-designed integrated and modularized framework, APT serves as a universal platform for researchers from different fields, such as plasma physics, accelerator physics, space science, fusion energy research, computational mathematics, software engineering, and high-performance computation. The APT code consists of seven main modules, including the I/O module, the initialization module, the particle pusher module, the parallelization module, the field configuration module, the external force-field module, and the extendible module. The I/O module, supported by Lua and Hdf5 projects, provides a user-friendly interface for both numerical simulation and data analysis. A series of new geometric numerical methods...

  6. Superposition Principle in Auger Recombination of Charged and Neutral Multicarrier States in Semiconductor Quantum Dots.

    Science.gov (United States)

    Wu, Kaifeng; Lim, Jaehoon; Klimov, Victor I

    2017-08-22

    Application of colloidal semiconductor quantum dots (QDs) in optical and optoelectronic devices is often complicated by unintentional generation of extra charges, which opens fast nonradiative Auger recombination pathways whereby the recombination energy of an exciton is quickly transferred to the extra carrier(s) and ultimately dissipated as heat. Previous studies of Auger recombination have primarily focused on neutral and, more recently, negatively charged multicarrier states. Auger dynamics of positively charged species remains more poorly explored due to difficulties in creating, stabilizing, and detecting excess holes in the QDs. Here we apply photochemical doping to prepare both negatively and positively charged CdSe/CdS QDs with two distinct core/shell interfacial profiles ("sharp" versus "smooth"). Using neutral and charged QD samples we evaluate Auger lifetimes of biexcitons, negative and positive trions (an exciton with an extra electron or a hole, respectively), and multiply negatively charged excitons. Using these measurements, we demonstrate that Auger decay of both neutral and charged multicarrier states can be presented as a superposition of independent elementary three-particle Auger events. As one of the manifestations of the superposition principle, we observe that the biexciton Auger decay rate can be presented as a sum of the Auger rates for independent negative and positive trion pathways. By comparing the measurements on the QDs with the "sharp" versus "smooth" interfaces, we also find that while affecting the absolute values of Auger lifetimes, manipulation of the shape of the confinement potential does not lead to violation of the superposition principle, which still allows us to accurately predict the biexciton Auger lifetimes based on the measured negative and positive trion dynamics. These findings indicate considerable robustness of the superposition principle as applied to Auger decay of charged and neutral multicarrier states

  7. Immunoglobulin class-switch recombination deficiencies.

    Science.gov (United States)

    Durandy, Anne; Kracker, Sven

    2012-07-30

    Immunoglobulin class-switch recombination deficiencies (Ig-CSR-Ds) are rare primary immunodeficiencies characterized by defective switched isotype (IgG/IgA/IgE) production. Depending on the molecular defect in question, the Ig-CSR-D may be combined with an impairment in somatic hypermutation (SHM). Some of the mechanisms underlying Ig-CSR and SHM have been described by studying natural mutants in humans. This approach has revealed that T cell-B cell interaction (resulting in CD40-mediated signaling), intrinsic B-cell mechanisms (activation-induced cytidine deaminase-induced DNA damage), and complex DNA repair machineries (including uracil-N-glycosylase and mismatch repair pathways) are all involved in class-switch recombination and SHM. However, several of the mechanisms required for full antibody maturation have yet to be defined. Elucidation of the molecular defects underlying the diverse set of Ig-CSR-Ds is essential for understanding Ig diversification and has prompted better definition of the clinical spectrum of diseases and the development of increasingly accurate diagnostic and therapeutic approaches.

  8. Comparison of immunoglobulin E measurements on IMMULITE and ImmunoCAP in samples consisting of allergen-specific mouse-human chimeric monoclonal antibodies towards allergen extracts and four recombinant allergens

    DEFF Research Database (Denmark)

    Szecsi, Pal B; Stender, Steen

    2013-01-01

    Specific immunoglobulin E (IgE) antibody in vitro tests are performed on enzyme immunoassay systems. Poor agreement among systems has been reported and comparisons have been made exclusively with allergen extracts - not with recombinant allergens. Here we compare the ImmunoCAP and the IMMULITE...

  9. Controlled release from recombinant polymers.

    Science.gov (United States)

    Price, Robert; Poursaid, Azadeh; Ghandehari, Hamidreza

    2014-09-28

    Recombinant polymers provide a high degree of molecular definition for correlating structure with function in controlled release. The wide array of amino acids available as building blocks for these materials lend many advantages including biorecognition, biodegradability, potential biocompatibility, and control over mechanical properties among other attributes. Genetic engineering and DNA manipulation techniques enable the optimization of structure for precise control over spatial and temporal release. Unlike the majority of chemical synthetic strategies used, recombinant DNA technology has allowed for the production of monodisperse polymers with specifically defined sequences. Several classes of recombinant polymers have been used for controlled drug delivery. These include, but are not limited to, elastin-like, silk-like, and silk-elastinlike proteins, as well as emerging cationic polymers for gene delivery. In this article, progress and prospects of recombinant polymers used in controlled release will be reviewed. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Three Decades of Recombinant DNA.

    Science.gov (United States)

    Palmer, Jackie

    1985-01-01

    Discusses highlights in the development of genetic engineering, examining techniques with recombinant DNA, legal and ethical issues, GenBank (a national database of nucleic acid sequences), and other topics. (JN)

  11. Controlled Release from Recombinant Polymers

    Science.gov (United States)

    Price, Robert; Poursaid, Azadeh; Ghandehari, Hamidreza

    2014-01-01

    Recombinant polymers provide a high degree of molecular definition for correlating structure with function in controlled release. The wide array of amino acids available as building blocks for these materials lend many advantages including biorecognition, biodegradability, potential biocompatibility, and control over mechanical properties among other attributes. Genetic engineering and DNA manipulation techniques enable the optimization of structure for precise control over spatial and temporal release. Unlike the majority of chemical synthetic strategies used, recombinant DNA technology has allowed for the production of monodisperse polymers with specifically defined sequences. Several classes of recombinant polymers have been used for controlled drug delivery. These include, but are not limited to, elastin-like, silk-like, and silk-elastinlike proteins, as well as emerging cationic polymers for gene delivery. In this article, progress and prospects of recombinant polymers used in controlled release will be reviewed. PMID:24956486

  12. Recombinant snake venom prothrombin activators

    OpenAIRE

    L?vgren, Ann

    2012-01-01

    Three prothrombin activators; ecarin, which was originally isolated from the venom of the saw-scaled viper Echis carinatus, trocarin from the rough-scaled snake Tropidechis carinatus, and oscutarin from the Taipan snake Oxyuranus scutellatus, were expressed in mammalian cells with the purpose to obtain recombinant prothrombin activators that could be used to convert prothrombin to thrombin. We have previously reported that recombinant ecarin can efficiently generate thrombin without the need ...

  13. Heterogeneity in recombinant protein production

    DEFF Research Database (Denmark)

    Schalén, Martin; Johanson, Ted; Lundin, Luisa

    2012-01-01

    contribute to make a population in a fermenter heterogeneous, resulting in cell-to-cell variation in physiological parameters of the microbial culture. Our study aims at investigating how population heterogeneity and recombinant protein production is affected by environmental gradients in bioreactors...... are simulated in small bioreactors and the population heterogeneity can be visualised by analysing single cells with flow cytometry. This can give new insights to cell physiology and recombinant protein production at the industrial scale....

  14. The accurate particle tracer code

    Science.gov (United States)

    Wang, Yulei; Liu, Jian; Qin, Hong; Yu, Zhi; Yao, Yicun

    2017-11-01

    The Accurate Particle Tracer (APT) code is designed for systematic large-scale applications of geometric algorithms for particle dynamical simulations. Based on a large variety of advanced geometric algorithms, APT possesses long-term numerical accuracy and stability, which are critical for solving multi-scale and nonlinear problems. To provide a flexible and convenient I/O interface, the libraries of Lua and Hdf5 are used. Following a three-step procedure, users can efficiently extend the libraries of electromagnetic configurations, external non-electromagnetic forces, particle pushers, and initialization approaches by use of the extendible module. APT has been used in simulations of key physical problems, such as runaway electrons in tokamaks and energetic particles in Van Allen belt. As an important realization, the APT-SW version has been successfully distributed on the world's fastest computer, the Sunway TaihuLight supercomputer, by supporting master-slave architecture of Sunway many-core processors. Based on large-scale simulations of a runaway beam under parameters of the ITER tokamak, it is revealed that the magnetic ripple field can disperse the pitch-angle distribution significantly and improve the confinement of energetic runaway beam on the same time.

  15. Immunoassays for the measurement of IGF-II, IGFBP-2 and -3, and ICTP as indirect biomarkers of recombinant human growth hormone misuse in sport. Values in selected population of athletes.

    Science.gov (United States)

    Abellan, Rosario; Ventura, Rosa; Palmi, Ilaria; di Carlo, Simonetta; Bacosi, Antonella; Bellver, Montse; Olive, Ramon; Pascual, Jose Antonio; Pacifici, Roberta; Segura, Jordi; Zuccaro, Piergiorgio; Pichini, Simona

    2008-11-04

    Insulin-like growth factor-II (IGF-II), insulin-like growth factor binding proteins (IGFBPs) -2 and -3 and C-terminal telopeptide of type I collagen (ICTP) have been proposed, among others, as indirect biomarkers of the recombinant human growth hormone misuse in sport. An extended intra- and inter-laboratory validation of commercially available immunoassays for biomarkers detection was performed. ELISA assays for total IGF-II, IGFBP-2 and IGFBP-3 (IGF-II/ELISA1: DSLabs, IGFBP-2/ELISA2: Biosource, and IGFBP-3/ELISA3: BioSource) and an EIA assay for ICTP (ICTP/EIA: Orion Diagnostica) were evaluated. The inter- and intra-laboratory precision values were acceptable for all evaluated assays (maximum imprecision of 30% and 66% were found only for the lowest quality control samples of IGF-II and IGFBP-3). Correct accuracy was obtained for all inter-laboratory immunoassays and for IGFBP-2 intra-laboratory immunoassay. The range of concentrations found in serum samples under investigation was always covered by the calibration curves of the studied immunoassays. However, 11% and 15% of the samples felt below the estimated LOQ for IGF-II and ICTP, respectively, in the zone where lower precision was obtained. Although the majority of evaluated assays showed an overall reliability not always suitable for antidoping control analysis, relatively high concordances between laboratory results were obtained for all assays. Evaluated immunoassays were used to measure serum concentrations of IGF-II, IGFBP-2 and -3 and ICTP in elite athletes of various sport disciplines at different moments of the training season; in recreational athletes at baseline conditions and finally in sedentary individuals. Serum IGF-II was statistically higher both in recreational and elite athletes compared to sedentary individuals. Elite athletes showed lower IGFBP-2 and higher IGFBP-3 concentration with respect to recreational athletes and sedentary people. Among elite athletes, serum IGFBP-3 (synchronized

  16. Recombinant vaccine for canine parvovirus in dogs.

    Science.gov (United States)

    López de Turiso, J A; Cortés, E; Martínez, C; Ruiz de Ybáñez, R; Simarro, I; Vela, C; Casal, I

    1992-01-01

    VP2 is the major component of canine parvovirus (CPV) capsids. The VP2-coding gene was engineered to be expressed by a recombinant baculovirus under the control of the polyhedrin promoter. A transfer vector that contains the lacZ gene under the control of the p10 promoter was used in order to facilitate the selection of recombinants. The expressed VP2 was found to be structurally and immunologically indistinguishable from authentic VP2. The recombinant VP2 shows also the capability to self-assemble, forming viruslike particles similar in size and appearance to CPV virions. These viruslike particles have been used to immunize dogs in different doses and combinations of adjuvants, and the anti-CPV responses have been measured by enzyme-linked immunosorbent assay, monolayer protection assays, and an assay for the inhibition of hemagglutination. A dose of ca. 10 micrograms of VP2 was able to elicit a good protective response, higher than that obtained with a commercially available, inactivated vaccine. The results indicate that these viruslike particles can be used to protect dogs from CPV infection. Images PMID:1313899

  17. RECOMBINANT HORSERADISH PEROXIDASE FOR ANALYTICAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    А.M. Egorov

    2012-08-01

    Full Text Available The article deals with prospects of using recombinant horseradish peroxidase in analytical biochemistry and biotechnology. Problems of recombinant horseradish peroxidase cloning in different expression systems, possible approaches to their solution, advantages of recombinant recombinant horseradish peroxidase and recombinant horseradish peroxidase-fusion proteins for immunoassays are considered. Possibility for development of mediatorless bienzyme biosensor for peroxide and metabolites, yielding hydrogen peroxide during their transformations, based on co-adsorption of recombinant horseradish peroxidase and the appropriate oxidase was demonstrated. The possibility to produce a fully active recombinant conjugate of recombinant horseradish peroxidase with human heart-type fatty acid binding protein, which may be used in competitive immunoassay for clinical diagnosis of acute myocardial infarction, and recombinant conjugates (N- and C-terminus of recombinant horseradish peroxidase with Fab-fragments of the antibody against atrazine, which may be applied for atrazine pesticides detection, are demonstra ted for the first time.

  18. Effective and Accurate Colormap Selection

    Science.gov (United States)

    Thyng, K. M.; Greene, C. A.; Hetland, R. D.; Zimmerle, H.; DiMarco, S. F.

    2016-12-01

    Science is often communicated through plots, and design choices can elucidate or obscure the presented data. The colormap used can honestly and clearly display data in a visually-appealing way, or can falsely exaggerate data gradients and confuse viewers. Fortunately, there is a large resource of literature in color science on how color is perceived which we can use to inform our own choices. Following this literature, colormaps can be designed to be perceptually uniform; that is, so an equally-sized jump in the colormap at any location is perceived by the viewer as the same size. This ensures that gradients in the data are accurately percieved. The same colormap is often used to represent many different fields in the same paper or presentation. However, this can cause difficulty in quick interpretation of multiple plots. For example, in one plot the viewer may have trained their eye to recognize that red represents high salinity, and therefore higher density, while in the subsequent temperature plot they need to adjust their interpretation so that red represents high temperature and therefore lower density. In the same way that a single Greek letter is typically chosen to represent a field for a paper, we propose to choose a single colormap to represent a field in a paper, and use multiple colormaps for multiple fields. We have created a set of colormaps that are perceptually uniform, and follow several other design guidelines. There are 18 colormaps to give options to choose from for intuitive representation. For example, a colormap of greens may be used to represent chlorophyll concentration, or browns for turbidity. With careful consideration of human perception and design principles, colormaps may be chosen which faithfully represent the data while also engaging viewers.

  19. Recombination drives vertebrate genome contraction.

    Science.gov (United States)

    Nam, Kiwoong; Ellegren, Hans

    2012-01-01

    Selective and/or neutral processes may govern variation in DNA content and, ultimately, genome size. The observation in several organisms of a negative correlation between recombination rate and intron size could be compatible with a neutral model in which recombination is mutagenic for length changes. We used whole-genome data on small insertions and deletions within transposable elements from chicken and zebra finch to demonstrate clear links between recombination rate and a number of attributes of reduced DNA content. Recombination rate was negatively correlated with the length of introns, transposable elements, and intergenic spacer and with the rate of short insertions. Importantly, it was positively correlated with gene density, the rate of short deletions, the deletion bias, and the net change in sequence length. All these observations point at a pattern of more condensed genome structure in regions of high recombination. Based on the observed rates of small insertions and deletions and assuming that these rates are representative for the whole genome, we estimate that the genome of the most recent common ancestor of birds and lizards has lost nearly 20% of its DNA content up until the present. Expansion of transposable elements can counteract the effect of deletions in an equilibrium mutation model; however, since the activity of transposable elements has been low in the avian lineage, the deletion bias is likely to have had a significant effect on genome size evolution in dinosaurs and birds, contributing to the maintenance of a small genome. We also demonstrate that most of the observed correlations between recombination rate and genome contraction parameters are seen in the human genome, including for segregating indel polymorphisms. Our data are compatible with a neutral model in which recombination drives vertebrate genome size evolution and gives no direct support for a role of natural selection in this process.

  20. Towards an accurate bioimpedance identification

    Science.gov (United States)

    Sanchez, B.; Louarroudi, E.; Bragos, R.; Pintelon, R.

    2013-04-01

    This paper describes the local polynomial method (LPM) for estimating the time-invariant bioimpedance frequency response function (FRF) considering both the output-error (OE) and the errors-in-variables (EIV) identification framework and compare it with the traditional cross— and autocorrelation spectral analysis techniques. The bioimpedance FRF is measured with the multisine electrical impedance spectroscopy (EIS) technique. To show the overwhelming accuracy of the LPM approach, both the LPM and the classical cross— and autocorrelation spectral analysis technique are evaluated through the same experimental data coming from a nonsteady-state measurement of time-varying in vivo myocardial tissue. The estimated error sources at the measurement frequencies due to noise, σnZ, and the stochastic nonlinear distortions, σZNL, have been converted to Ω and plotted over the bioimpedance spectrum for each framework. Ultimately, the impedance spectra have been fitted to a Cole impedance model using both an unweighted and a weighted complex nonlinear least square (CNLS) algorithm. A table is provided with the relative standard errors on the estimated parameters to reveal the importance of which system identification frameworks should be used.

  1. Accurate measurement of the energy dependence of the process $e^{+} + e^{-} \\to e^{\\pm} + e^{\\mp}$, in the s-range 1.44-9.0 $GeV^{2}$

    CERN Document Server

    Bernardini, M; Brunini, P L; Fiorentino, E; Massam, Thomas; Monari, L; Palmonari, F; Rimondi, F; Zichichi, A

    1973-01-01

    The analysis of 12827 e/sup +/+e/sup -/ to e/sup +or-/+e/sup -or+/ events observed in the s-range 1.44-9.0 GeV/sup 2/ allows measurement of the energy dependence of the cross-section for the most typical QED process, with +or-2% accuracy. Within this limit the data follow QED, with first-order radiative corrections included.

  2. Accurate lineshape spectroscopy and the Boltzmann constant.

    Science.gov (United States)

    Truong, G-W; Anstie, J D; May, E F; Stace, T M; Luiten, A N

    2015-10-14

    Spectroscopy has an illustrious history delivering serendipitous discoveries and providing a stringent testbed for new physical predictions, including applications from trace materials detection, to understanding the atmospheres of stars and planets, and even constraining cosmological models. Reaching fundamental-noise limits permits optimal extraction of spectroscopic information from an absorption measurement. Here, we demonstrate a quantum-limited spectrometer that delivers high-precision measurements of the absorption lineshape. These measurements yield a very accurate measurement of the excited-state (6P1/2) hyperfine splitting in Cs, and reveals a breakdown in the well-known Voigt spectral profile. We develop a theoretical model that accounts for this breakdown, explaining the observations to within the shot-noise limit. Our model enables us to infer the thermal velocity dispersion of the Cs vapour with an uncertainty of 35 p.p.m. within an hour. This allows us to determine a value for Boltzmann's constant with a precision of 6 p.p.m., and an uncertainty of 71 p.p.m.

  3. Accurate metacognition for visual sensory memory representations.

    Science.gov (United States)

    Vandenbroucke, Annelinde R E; Sligte, Ilja G; Barrett, Adam B; Seth, Anil K; Fahrenfort, Johannes J; Lamme, Victor A F

    2014-04-01

    The capacity to attend to multiple objects in the visual field is limited. However, introspectively, people feel that they see the whole visual world at once. Some scholars suggest that this introspective feeling is based on short-lived sensory memory representations, whereas others argue that the feeling of seeing more than can be attended to is illusory. Here, we investigated this phenomenon by combining objective memory performance with subjective confidence ratings during a change-detection task. This allowed us to compute a measure of metacognition--the degree of knowledge that subjects have about the correctness of their decisions--for different stages of memory. We show that subjects store more objects in sensory memory than they can attend to but, at the same time, have similar metacognition for sensory memory and working memory representations. This suggests that these subjective impressions are not an illusion but accurate reflections of the richness of visual perception.

  4. Measurement of the (pressure, density, temperature) relation of two (methane + nitrogen) gas mixtures at temperatures between 240 and 400 K and pressures up to 20 MPa using an accurate single-sinker densimeter

    Energy Technology Data Exchange (ETDEWEB)

    Chamorro, C.R. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47071 Valladolid (Spain)]. E-mail: cescha@eis.uva.es; Segovia, J.J. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47071 Valladolid (Spain); Martin, M.C. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47071 Valladolid (Spain); Villamanan, M.A. [Grupo de Termodinamica y Calibracion (TERMOCAL), Dpto. Ingenieria Energetica y Fluidomecanica, E.T.S. de Ingenieros Industriales, Universidad de Valladolid, E-47071 Valladolid (Spain); Estela-Uribe, J.F. [Facultad de Ingenieria, Universidad Javeriana-Cali, Calle 18, 118-250 Cali (Colombia); Trusler, J.P.M. [Department of Chemical Engineering, Imperial College London, London SW7 2AZ (United Kingdom)

    2006-07-15

    Comprehensive (p, {rho}, T) measurements on two gas mixtures of (0.9CH{sub 4} + 0.1N{sub 2}) and (0.8CH{sub 4} + 0.2N{sub 2}) have been carried out at six temperatures between 240 and 400 K and at pressures up to 20 MPa. A total of 108 (p, {rho}, T) data for the first mixture and 134 for the second one are given. These measurements were performed using a compact single-sinker densimeter based on Archimedes' buoyancy principle. The overall uncertainty in density {rho} is estimated to be (1.5 . 10{sup -4} . {rho} + 2 . 10{sup -3} kg . m{sup -3}) (coverage factor k = 2), the uncertainty in temperature T is estimated to be 0.006 K (coverage factor k = 2), and the uncertainty in pressure p is estimated to be 1 . 10{sup -4}.p (coverage factor k = 2). The equipment has been previously checked with pure nitrogen over the whole temperature and pressure working ranges and experimental results (35 values) are given and a comparison with the reference equation of state for nitrogen is presented.

  5. Accurate stopping power measurements for (0.21–2.68) MeV/u {sup 1}H{sup +} and {sup 4}He{sup +} ions crossing thin Al foils; extraction of the (I, b) parameters

    Energy Technology Data Exchange (ETDEWEB)

    Moussa, D., E-mail: djamelmoussa@gmail.com [Université des Sciences et Technologie H. Boumediene (USTHB), Laboratoire SNIRM, Faculté de Physique, B.P. 32, 16111 Bab-Ezzouar, Algiers (Algeria); Damache, S. [Division de Physique, CRNA, 02 Bd. Frantz Fanon, B.P. 399 Alger-gare, Algiers (Algeria); Ouichaoui, S., E-mail: souichaoui@gmail.com [Université des Sciences et Technologie H. Boumediene (USTHB), Laboratoire SNIRM, Faculté de Physique, B.P. 32, 16111 Bab-Ezzouar, Algiers (Algeria)

    2015-01-15

    The stopping powers of thin Al foils for H{sup +} and {sup 4}He{sup +} ions have been measured over the energy range E=(206.03–2680.05) keV/amu with an overall relative uncertainty better than 1% using the transmission method. The derived S(E) experimental data are compared to previous ones from the literature, to values derived by the SRIM-2008 code or compiled in the ICRU-49 report, and to the predictions of Sigmund–Schinner binary collision stopping theory. Besides, the S(E) data for H{sup +} ions together with those for He{sup 2+} ions reported by Andersen et al. (1977) have been analyzed over the energy interval E>1.0 MeV using the modified Bethe–Bloch stopping theory. The following sets of values have been inferred for the mean excitation potential, I, and the Barkas–Andersen parameter, b, for H{sup +} and He{sup +} projectiles, respectively: {(I=164±3)) eV, (b=1.40} and {(I=163±2.5)) eV, (b=1.38}. As expected, the I parameter is found to be independent of the projectile electronic structure presumably indicating that the contribution of charge exchange effects becomes negligible as the projectile velocity increases. Therefore, the I parameter must be determined from precise stopping power measurements performed at high projectile energies where the Bethe stopping theory is fully valid.

  6. Extensive recombination due to heteroduplexes generates large amounts of artificial gene fragments during PCR.

    Directory of Open Access Journals (Sweden)

    Jia Liu

    Full Text Available Artificial recombinants can be generated during PCR when more than two genetically distinct templates coexist in a single PCR reaction. These recombinant amplicons can lead to the false interpretation of genetic diversity and incorrect identification of biological phenotypes that do not exist in vivo. We investigated how recombination between 2 or 35 genetically distinct HIV-1 genomes was affected by different PCR conditions using the parallel allele-specific sequencing (PASS assay and the next generation sequencing method. In a standard PCR condition, about 40% of amplicons in a PCR reaction were recombinants. The high recombination frequency could be significantly reduced if the number of amplicons in a PCR reaction was below a threshold of 10(13-10(14 using low thermal cycles, fewer input templates, and longer extension time. Heteroduplexes (each DNA strand from a distinct template were present at a large proportion in the PCR products when more thermal cycles, more templates, and shorter extension time were used. Importantly, the majority of recombinants were identified in heteroduplexes, indicating that the recombinants were mainly generated through heteroduplexes. Since prematurely terminated extension fragments can form heteroduplexes by annealing to different templates during PCR amplification, recombination has a better chance to occur with samples containing different genomes when the number of amplicons accumulate over the threshold. New technologies are warranted to accurately characterize complex quasispecies gene populations.

  7. Accurate Alignment of Plasma Channels Based on Laser Centroid Oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl; Geddes, Cameron; Toth, Csaba; Esarey, Eric; Leemans, Wim

    2011-03-23

    A technique has been developed to accurately align a laser beam through a plasma channel by minimizing the shift in laser centroid and angle at the channel outptut. If only the shift in centroid or angle is measured, then accurate alignment is provided by minimizing laser centroid motion at the channel exit as the channel properties are scanned. The improvement in alignment accuracy provided by this technique is important for minimizing electron beam pointing errors in laser plasma accelerators.

  8. Radiative and temperature effects of aerosol simulated by the COSMO-Ru model for different atmospheric conditions and their testing against ground-based measurements and accurate RT simulations

    Science.gov (United States)

    Chubarova, Nataly; Poliukhov, Alexei; Shatunova, Marina; Rivin, Gdali; Becker, Ralf; Muskatel, Harel; Blahak, Ulrich; Kinne, Stefan; Tarasova, Tatiana

    2017-04-01

    We use the operational Russian COSMO-Ru weather forecast model (Ritter and and Geleyn, 1991) with different aerosol input data for the evaluation of radiative and temperature effects of aerosol in different atmospheric conditions. Various aerosol datasets were utilized including Tegen climatology (Tegen et al., 1997), updated Macv2 climatology (Kinne et al., 2013), Tanre climatology (Tanre et al., 1984) as well as the MACC data (Morcrette et al., 2009). For clear sky conditions we compare the radiative effects from the COSMO-Ru model over Moscow (55.7N, 37.5E) and Lindenberg/Falkenberg sites (52.2N, 14.1E) with the results obtained using long-term aerosol measurements. Additional tests of the COSMO RT code were performed against (FC05)-SW model (Tarasova T.A. and Fomin B.A., 2007). The overestimation of about 5-8% of COSMO RT code was obtained. The study of aerosol effect on temperature at 2 meters has revealed the sensitivity of about 0.7-1.1 degree C per 100 W/m2 change in shortwave net radiation due to aerosol variations. We also discuss the radiative impact of urban aerosol properties according to the long-term AERONET measurements in Moscow and Moscow suburb as well as long-term aerosol trends over Moscow from the measurements and Macv2 dataset. References: Kinne, S., O'Donnel D., Stier P., et al., J. Adv. Model. Earth Syst., 5, 704-740, 2013. Morcrette J.-J.,O. Boucher, L. Jones, eet al, J.GEOPHYS. RES.,VOL. 114, D06206, doi:10.1029/2008JD011235, 2009. Ritter, B. and Geleyn, J., Monthly Weather Review, 120, 303-325, 1992. Tanre, D., Geleyn, J., and Slingo, J., A. Deepak Publ., Hampton, Virginia, 133-177, 1984. Tarasova, T., and Fomin, B., Journal of Atmospheric and Oceanic Technology, 24, 1157-1162, 2007. Tegen, I., Hollrig, P., Chin, M., et al., Journal of Geophysical Research- Atmospheres, 102, 23895-23915, 1997.

  9. A Mechanistic Model of a Passive Autocatalytic Hydrogen Recombiner

    Directory of Open Access Journals (Sweden)

    Rożeń Antoni

    2015-03-01

    Full Text Available : A passive autocatalytic hydrogen recombiner (PAR is a self-starting device, without operator action or external power input, installed in nuclear power plants to remove hydrogen from the containment building of a nuclear reactor. A new mechanistic model of PAR has been presented and validated by experimental data and results of Computational Fluid Dynamics (CFD simulations. The model allows to quickly and accurately predict gas temperature and composition, catalyst temperature and hydrogen recombination rate. It is assumed in the model that an exothermic recombination reaction of hydrogen and oxygen proceeds at the catalyst surface only, while processes of heat and mass transport occur by assisted natural and forced convection in non-isothermal and laminar gas flow conditions in vertical channels between catalyst plates. The model accounts for heat radiation from a hot catalyst surface and has no adjustable parameters. It can be combined with an equation of chimney draft and become a useful engineering tool for selection and optimisation of catalytic recombiner geometry.

  10. Accurate Emission Line Diagnostics at High Redshift

    Science.gov (United States)

    Jones, Tucker

    2017-08-01

    How do the physical conditions of high redshift galaxies differ from those seen locally? Spectroscopic surveys have invested hundreds of nights of 8- and 10-meter telescope time as well as hundreds of Hubble orbits to study evolution in the galaxy population at redshifts z 0.5-4 using rest-frame optical strong emission line diagnostics. These surveys reveal evolution in the gas excitation with redshift but the physical cause is not yet understood. Consequently there are large systematic errors in derived quantities such as metallicity.We have used direct measurements of gas density, temperature, and metallicity in a unique sample at z=0.8 to determine reliable diagnostics for high redshift galaxies. Our measurements suggest that offsets in emission line ratios at high redshift are primarily caused by high N/O abundance ratios. However, our ground-based data cannot rule out other interpretations. Spatially resolved Hubble grism spectra are needed to distinguish between the remaining plausible causes such as active nuclei, shocks, diffuse ionized gas emission, and HII regions with escaping ionizing flux. Identifying the physical origin of evolving excitation will allow us to build the necessary foundation for accurate measurements of metallicity and other properties of high redshift galaxies. Only then can we expoit the wealth of data from current surveys and near-future JWST spectroscopy to understand how galaxies evolve over time.

  11. Accurate measurement of the essential micronutrients methionine, homocysteine, vitamins B6, B12, B9 and their metabolites in plasma, brain and maternal milk of mice using LC/MS ion trap analysis.

    Science.gov (United States)

    Oosterink, J Efraim; Naninck, Eva F G; Korosi, Aniko; Lucassen, Paul J; van Goudoever, Johannes B; Schierbeek, Henk

    2015-08-15

    Methionine, homocysteine, vitamins B6, B12, B9, and their metabolites are crucial co-factors and substrates for many basic biological pathways including one-carbon metabolism, and they are particularly important for brain function and development and epigenetic mechanisms. These are essential nutrients that cannot be synthesized endogenously and thus need to be taken in via diet. A novel method was developed that enables simultaneous assessment of the exact concentrations of these essential micronutrients in various matrices, including maternal milk, plasma, and brain of neonatal mice. The protocol for analysis of these components in the various matrices consists of a cleanup step (i.e. lipid extraction followed by protein precipitation) combined with a liquid chromatography mass spectrometry (LC/MS) ion trap method with high sensitivity and selectivity (SRM mode). This novel method enables the measurement of these essential nutrients with good recoveries (69-117%), and high intra-day (<10%) and high intra-day precision (defined as <15% for compounds with an isotopologue and <20% for compounds without an isotopologue as internal standard) in plasma, maternal milk, and brain of mice at low and high levels. In addition, lower limits of quantitation (LOQ) were determined for the various matrices in the range for methionine (700-2000nmol/L), homocysteine (280-460-nmol/L), vitamins B6 (5-230nmol/L), B12 (7-11nmol/L), B9 (20-30nmol/L). Degradation of vitamins and oxidation of homocysteine is limited to a minimum, and only small sample volumes (30μL plasma, 20mg brain and maternal milk) are needed for simultaneous measurement. This method can help to understand how these nutrients are transferred from mother to offspring via maternal milk, as well as how these nutrients are absorbed by the offspring and eventually taken up in various tissues amongst the brain in preclinical and clinical research settings. Therefore the method can help to explore critical periods in

  12. High Interspecimen Variability in Nucleic Acid Extraction Efficiency Necessitates the Use of Spike-In Control for Accurate qPCR-based Measurement of Plasma Cell-Free DNA Levels.

    Science.gov (United States)

    O'Connell, Grant C; Chantler, Paul D; Barr, Taura L

    2017-11-08

    To assess the interspecimen variability associated with plasma DNA extraction in order to provide insight regarding the necessity to use an exogenous spike-in control when measuring cell-free DNA (cfDNA) levels using quantitative polymerase chain reaction (qPCR). Plasma specimens were obtained from 8 healthy individuals, 20 patients with cardiovascular disease risk factors, and 54 patients diagnosed with acute stroke. Specimens were spiked with an exogenous oligonucleotide fragment, and total DNA was extracted via automated solid phase anion exchange. We determined recovery of the exogenous fragment via qPCR and used this information to calculate DNA extraction efficiency. Plasma DNA extraction efficiencies varied dramatically between specimens, ranging from 22.9% to 88.1%, with a coefficient of variance of 28.9%. No significant differences in DNA extraction efficiencies were observed between patient populations. We strongly recommend the use of an exogenous spike-in control to account for variance in plasma DNA extraction efficiency when assessing cell free DNA (cfDNA) levels by qPCR in future biomarker investigations.

  13. Influenza Vaccine, Inactivated or Recombinant

    Science.gov (United States)

    ... die from flu, and many more are hospitalized.Flu vaccine can:keep you from getting flu, make flu ... What is inactivated or recombinant influenza vaccine?A dose of flu vaccine is recommended every flu season. Children 6 months through 8 years of age may need two ...

  14. Molecular Mechanism for Genetic Recombination

    Science.gov (United States)

    Sobell, Henry M.

    1972-01-01

    Symmetry considerations of proteinnucleic acid interaction suggest the existence of an alternate branched configuration for DNA induced by binding specific structural proteins to symmetrically arranged polynucleotide base sequences. The concept that such sequences exist at the ends of genes or operons leads to a molecular model for genetic recombination in eukaryotic cells. PMID:4115953

  15. Genetic recombination and molecular evolution.

    Science.gov (United States)

    Charlesworth, B; Betancourt, A J; Kaiser, V B; Gordo, I

    2009-01-01

    Reduced rates of genetic recombination are often associated with reduced genetic variability and levels of adaptation. Several different evolutionary processes, collectively known as Hill-Robertson (HR) effects, have been proposed as causes of these correlates of recombination. Here, we use DNA sequence polymorphism and divergence data from the noncrossing over dot chromosome of Drosophila to discriminate between two of the major forms of HR effects: selective sweeps and background selection. This chromosome shows reduced levels of silent variability and reduced effectiveness of selection. We show that neither model fits the data on variability. We propose that, in large genomic regions with restricted recombination, HR effects among nonsynonymous mutations undermine the effective strength of selection, so that their background selection effects are weakened. This modified model fits the data on variability and also explains why variability in very large nonrecombining genomes is not completely wiped out. We also show that HR effects of this type can produce an individual selection advantage to recombination, as well as greatly reduce the mean fitness of nonrecombining genomes and genomic regions.

  16. Recombination in immunoglobulin gene loci

    Directory of Open Access Journals (Sweden)

    Komisarenko S. V.

    2009-02-01

    Full Text Available Gene network of the lymphoid cell differentiation coordinates precisely the recombination process in immunoglobulin gene loci. In our opinion, cellular microRNAs can contribute to the allelic exclusion through microRNA-directed DNA methylation and participate in retargeting recombinases activity from the gene loci of heavy immunoglobulin chains to the gene loci of light chains

  17. Atomic Data for Neutron-capture Elements I. Photoionization and Recombination Properties of Low-charge Selenium Ions

    Science.gov (United States)

    Sterling, N. C.; Witthoeft, Michael

    2011-01-01

    We present multi-configuration Breit-Pauli AUTOSTRUCTURE calculations of distorted-wave photoionization (PI) cross sections. and total and partial final-state resolved radiative recombination (RR) and dielectronic recombination (DR) rate coefficients for the first six ions of the trans-iron element Se. These calculations were motivated by the recent detection of Se emission lines in a large number of planetary nebulae. Se is a potentially useful tracer of neutron-capture nucleosynthesis. but accurate determinations of its abundance in photoionized nebulae have been hindered by the lack of atomic data governing its ionization balance. Our calculations were carried out in intermediate coupling with semi re1ativistic radial wavefunctions. PI and recombination data were determined for levels within the ground configuration of each ion, and experimental PI cross-section measurements were used to benchmark our results. For DR, we allowed (Delta)n = 0 core excitations, which are important at photoionized plasma temperatures. We find that DR is the dominant recombination process for each of these Se ions at temperatures representative of photoionized nebulae (approx.10(exp 4) K). In order to estimate the uncertainties of these data, we compared results from three different configuration-interaction expansions for each ion, and also tested the sensitivity of the results to the radial scaling factors in the structure calculations. We find that the internal uncertainties are typically 30-50% for the direct PI cross sections and approx.10% for the computed RR rate coefficients, while those for low-temperature DR can be considerably larger (from 15-30% up to two orders of magnitude) due to the unknown energies of near-threshold autoionization resonances. These data are available at the CDS, and fitting coefficients to the total RR and DR rate coefficients are presented. The results are suitable for incorporation into photoionization codes used to numerically simulate

  18. Initiation of meiotic recombination in Ustilago maydis

    National Research Council Canada - National Science Library

    Kojic, Milorad; Sutherland, Jeanette H; Pérez-Martín, José; Holloman, William K

    2013-01-01

    .... Ustilago maydis, a biotrophic fungus that parasitizes maize, has long been utilized as an experimental system for studying recombination, but it has not been clear when in the life cycle meiotic recombination initiates. U...

  19. GARD: a genetic algorithm for recombination detection

    National Research Council Canada - National Science Library

    Kosakovsky Pond, Sergei L; Posada, David; Gravenor, Michael B; Woelk, Christopher H; Frost, Simon D W

    2006-01-01

    .... We developed a likelihood-based model selection procedure that uses a genetic algorithm to search multiple sequence alignments for evidence of recombination breakpoints and identify putative recombinant sequences...

  20. Accurate intelligence assessments in social interactions: mediators and gender effects.

    Science.gov (United States)

    Murphy, Nora A; Hall, Judith A; Colvin, C Randal

    2003-06-01

    Research indicates that people can assess a stranger's measured intelligence more accurately than expected by chance, based on minimal information involving appearance and behavior. The present research documents behavioral correlates of perceived and measured intelligence and identifies behaviors that mediate the relationship between perceived and measured intelligence. In particular, when judges rated targets with video and auditory stimuli available, responsiveness to conversation partner, eye-gaze, and looking at partner while speaking were each significant mediators in the accurate assessment of intelligence. Each of those behaviors, as well as the percentage of looking at partner while speaking as a function of the target's own speaking time, were significant mediators in the video silent condition. Additionally, judge and target gender contributed to accurate intelligence assessments.

  1. Is the segmented plasma excitation recombination laser a recombination laser

    Energy Technology Data Exchange (ETDEWEB)

    Apollonov, V.V.; Sirotkin, A.A. (Institut Obshchei Fiziki, Moscow (USSR))

    1989-10-01

    The role of plasmachemical reactions in the formation of active media in lasers with a sectional plasma source for metal vapor is investigated. It is shown that the population of ionic levels in Cd II and Zn II occurs under recharging with He(+) and in the process of Penning ionization. It is found that these processes are more efficient than recombination and electron impact. 13 refs.

  2. Accurate quantitation of circulating cell-free mitochondrial DNA in plasma by droplet digital PCR.

    Science.gov (United States)

    Ye, Wei; Tang, Xiaojun; Liu, Chu; Wen, Chaowei; Li, Wei; Lyu, Jianxin

    2017-04-01

    To establish a method for accurate quantitation of circulating cell-free mitochondrial DNA (ccf-mtDNA) in plasma by droplet digital PCR (ddPCR), we designed a ddPCR method to determine the copy number of ccf-mtDNA by amplifying mitochondrial ND1 (MT-ND1). To evaluate the sensitivity and specificity of the method, a recombinant pMD18-T plasmid containing MT-ND1 sequences and mtDNA-deleted (ρ 0 ) HeLa cells were used, respectively. Subsequently, different plasma samples were prepared for ddPCR to evaluate the feasibility of detecting plasma ccf-mtDNA. In the results, the ddPCR method showed high sensitivity and specificity. When the DNA was extracted from plasma prior to ddPCR, the ccf-mtDNA copy number was higher than that measured without extraction. This difference was not due to a PCR inhibitor, such as EDTA-Na 2 , an anti-coagulant in plasma, because standard EDTA-Na 2 concentration (5 mM) did not significantly inhibit ddPCR reactions. The difference might be attributable to plasma exosomal mtDNA, which was 4.21 ± 0.38 copies/μL of plasma, accounting for ∼19% of plasma ccf-mtDNA. Therefore, ddPCR can quickly and reliably detect ccf-mtDNA from plasma with a prior DNA extraction step, providing for a more accurate detection of ccf-mtDNA. The direct use of plasma as a template in ddPCR is suitable for the detection of exogenous cell-free nucleic acids within plasma, but not of nucleic acids that have a vesicle-associated form, such as exosomal mtDNA. Graphical Abstract Designs of the present work. *: Module 1, #: Module 2, &: Module 3.

  3. Genome-wide fine-scale recombination rate variation in Drosophila melanogaster.

    Science.gov (United States)

    Chan, Andrew H; Jenkins, Paul A; Song, Yun S

    2012-01-01

    Estimating fine-scale recombination maps of Drosophila from population genomic data is a challenging problem, in particular because of the high background recombination rate. In this paper, a new computational method is developed to address this challenge. Through an extensive simulation study, it is demonstrated that the method allows more accurate inference, and exhibits greater robustness to the effects of natural selection and noise, compared to a well-used previous method developed for studying fine-scale recombination rate variation in the human genome. As an application, a genome-wide analysis of genetic variation data is performed for two Drosophila melanogaster populations, one from North America (Raleigh, USA) and the other from Africa (Gikongoro, Rwanda). It is shown that fine-scale recombination rate variation is widespread throughout the D. melanogaster genome, across all chromosomes and in both populations. At the fine-scale, a conservative, systematic search for evidence of recombination hotspots suggests the existence of a handful of putative hotspots each with at least a tenfold increase in intensity over the background rate. A wavelet analysis is carried out to compare the estimated recombination maps in the two populations and to quantify the extent to which recombination rates are conserved. In general, similarity is observed at very broad scales, but substantial differences are seen at fine scales. The average recombination rate of the X chromosome appears to be higher than that of the autosomes in both populations, and this pattern is much more pronounced in the African population than the North American population. The correlation between various genomic features-including recombination rates, diversity, divergence, GC content, gene content, and sequence quality-is examined using the wavelet analysis, and it is shown that the most notable difference between D. melanogaster and humans is in the correlation between recombination and diversity.

  4. Accurate Biomass Estimation via Bayesian Adaptive Sampling

    Science.gov (United States)

    Wheeler, K.; Knuth, K.; Castle, P.

    2005-12-01

    Typical estimates of standing wood derived from remote sensing sources take advantage of aggregate measurements of canopy heights (e.g. LIDAR) and canopy diameters (segmentation of IKONOS imagery) to obtain a wood volume estimate by assuming homogeneous species and a fixed function that returns volume. The validation of such techniques use manually measured diameter at breast height records (DBH). Our goal is to improve the accuracy and applicability of biomass estimation methods to heterogeneous forests and transitional areas. We are developing estimates with quantifiable uncertainty using a new form of estimation function, active sampling, and volumetric reconstruction image rendering for species specific mass truth. Initially we are developing a Bayesian adaptive sampling method for BRDF associated with the MISR Rahman model with respect to categorical biomes. This involves characterizing the probability distributions of the 3 free parameters of the Rahman model for the 6 categories of biomes used by MISR. Subsequently, these distributions can be used to determine the optimal sampling methodology to distinguish biomes during acquisition. We have a remotely controlled semi-autonomous helicopter that has stereo imaging, lidar, differential GPS, and spectrometers covering wavelengths from visible to NIR. We intend to automatically vary the way points of the flight path via the Bayesian adaptive sampling method. The second critical part of this work is in automating the validation of biomass estimates via using machine vision techniques. This involves taking 2-D pictures of trees of known species, and then via Bayesian techniques, reconstructing 3-D models of the trees to estimate the distribution moments associated with wood volume. Similar techniques have been developed by the medical imaging community. This then provides probability distributions conditional upon species. The final part of this work is in relating the BRDF actively sampled measurements to species

  5. ORIGINAL ARTICLE ORIG Is airway diameter measured accurately ...

    African Journals Online (AJOL)

    tracheal or bronchial stenoses includes bronchoscopy and CT (computed tomography).2 This process affords the opportunity to study aspects of CT relating to airway stenosis. Axial CT scans produce excellent resolution in the horizontal plane, but the extent of airway disease may be underestimated if only axial images are ...

  6. Accurate measurement of microscopic forces and torques using optical tweezers

    CSIR Research Space (South Africa)

    McLaren, M

    2011-09-01

    Full Text Available , Dholakia K, Allen L, Padgett MJ. Mechanical equivalence of spin and orbital angular momentum of light: An optical spanner. Opt Lett. 1997;22:52?54. doi:10.1364/OL.22.000052, PMid:18183100 17. Allen L, Beijersbergen MW, Spreeuw RJC, Woerdman JP. Orbital...

  7. Low-Cost Sensors Deliver Nanometer-Accurate Measurements

    Science.gov (United States)

    2015-01-01

    As part of a unique partnership program, Kennedy Space Center collaborated with a nearby business school to allow MBA students to examine and analyze the market potential for a selection of NASA-patented technologies. Following the semester, a group of students decided to form Winter Park, Florida-based Juntura Group Inc. to license and sell a technology they had worked with: a sensor capable of detecting position changes as small as 10 nanometers-approximately the thickness of a cell wall.

  8. Microbial factories for recombinant pharmaceuticals

    OpenAIRE

    Domingo-Espín Joan; Ferrer-Miralles Neus; Corchero José; Vázquez Esther; Villaverde Antonio

    2009-01-01

    Abstract Most of the hosts used to produce the 151 recombinant pharmaceuticals so far approved for human use by the Food and Drug Administration (FDA) and/or by the European Medicines Agency (EMEA) are microbial cells, either bacteria or yeast. This fact indicates that despite the diverse bottlenecks and obstacles that microbial systems pose to the efficient production of functional mammalian proteins, namely lack or unconventional post-translational modifications, proteolytic instability, po...

  9. Workshop on Radio Recombination Lines

    CERN Document Server

    1980-01-01

    Since their first detection 15 years ago, radio recombination lines from several elements have been observed in a wide variety of objects including HII regions, planetary nebulae, molecular clouds, the diffuse interstellar medium, and recently, other galaxies. The observations span almost the entire range from 0.1 to 100 GHz, and employ both single­ djsh and aperture synthesis techniques. The theory of radio recombination lines has also advanced strongly, to the point where it is perhaps one of the best-understood in astro­ physics. In a parallel development, it has become possible over the last decade to study these same highly-excited atoms in the laboratory; this work provides further confirmation of the theoretical framework. However there has been continuing controversy over the astrophysical interpre­ tation of radio recombination line observations, especially regarding the role of stimulated emission. A workshop was held in Ottawa on 24-25 August, 1979, bringing together many of the active scientist...

  10. Production systems for recombinant antibodies.

    Science.gov (United States)

    Schirrmann, Thomas; Al-Halabi, Laila; Dübel, Stefan; Hust, Michael

    2008-05-01

    Recombinant antibodies are the fastest growing class of therapeutic proteins. Furthermore, antibodies are key detection reagents in research and diagnostics. The increasing demand for antibodies with regards to amount and quality resulted in the development of a variety of recombinant production systems employing gram-negative and gram-positive bacteria, yeast and filamentous fungi, insect cell lines as well as mammalian cell lines. More recently, antibodies were also successfully produced in transgenic plants and animals. Currently, the production of recombinant antibodies for therapy is performed in mammalian cell lines to reduce the risk of immunogenicity caused by non-human post-translational modifications, in particular glycosylation. However, novel strategies already allow human-like glycosylation patterns in yeast, insect cell lines and transgenic plants. Furthermore, therapeutic strategies not requiring glycosylation of the Fc portion have been conceived, most prominently using bispecific antibodies or scFv fusion proteins, which can be produced in bacteria. Here, we review all current antibody production systems considering their advantages and limitations with respect to intended applications.

  11. The landscape of recombination in African Americans

    Science.gov (United States)

    Hinch, Anjali G.; Tandon, Arti; Patterson, Nick; Song, Yunli; Rohland, Nadin; Palmer, Cameron D.; Chen, Gary K.; Wang, Kai; Buxbaum, Sarah G.; Akylbekova, Meggie; Aldrich, Melinda C.; Ambrosone, Christine B.; Amos, Christopher; Bandera, Elisa V.; Berndt, Sonja I.; Bernstein, Leslie; Blot, William J.; Bock, Cathryn H.; Boerwinkle, Eric; Cai, Qiuyin; Caporaso, Neil; Casey, Graham; Cupples, L. Adrienne; Deming, Sandra L.; Diver, W. Ryan; Divers, Jasmin; Fornage, Myriam; Gillanders, Elizabeth M.; Glessner, Joseph; Harris, Curtis C.; Hu, Jennifer J.; Ingles, Sue A.; Isaacs, Williams; John, Esther M.; Kao, W. H. Linda; Keating, Brendan; Kittles, Rick A.; Kolonel, Laurence N.; Larkin, Emma; Le Marchand, Loic; McNeill, Lorna H.; Millikan, Robert C.; Murphy, Adam; Musani, Solomon; Neslund-Dudas, Christine; Nyante, Sarah; Papanicolaou, George J.; Press, Michael F.; Psaty, Bruce M.; Reiner, Alex P.; Rich, Stephen S.; Rodriguez-Gil, Jorge L.; Rotter, Jerome I.; Rybicki, Benjamin A.; Schwartz, Ann G.; Signorello, Lisa B.; Spitz, Margaret; Strom, Sara S.; Thun, Michael J.; Tucker, Margaret A.; Wang, Zhaoming; Wiencke, John K.; Witte, John S.; Wrensch, Margaret; Wu, Xifeng; Yamamura, Yuko; Zanetti, Krista A.; Zheng, Wei; Ziegler, Regina G.; Zhu, Xiaofeng; Redline, Susan; Hirschhorn, Joel N.; Henderson, Brian E.; Taylor, Herman A.; Price, Alkes L.; Hakonarson, Hakon; Chanock, Stephen J.; Haiman, Christopher A.; Wilson, James G.; Reich, David; Myers, Simon R.

    2011-01-01

    Recombination, together with mutation, is the ultimate source of genetic variation in populations. We leverage the recent mixture of people of African and European ancestry in the Americas to build a genetic map measuring the probability of crossing-over at each position in the genome, based on about 2.1 million crossovers in 30,000 unrelated African Americans. At intervals of more than three megabases it is nearly identical to a map built in Europeans. At finer scales it differs significantly, and we identify about 2,500 recombination hotspots that are active in people of West African ancestry but nearly inactive in Europeans. The probability of a crossover at these hotspots is almost fully controlled by the alleles an individual carries at PRDM9 (P<10−245). We identify a 17 base pair DNA sequence motif that is enriched in these hotspots, and is an excellent match to the predicted binding target of African-enriched alleles of PRDM9. PMID:21775986

  12. Nondisjunction of chromosome 15: Origin and recombination

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, W.P.; Bernasconi, F.; Schinzel, A.A.; Mutirangura, A.; Ledbetter, D.H. (Baylor College of Medicine, Houston, TX (United States)); Langlois, S. (Univ. of Britisch Columbia, Vancouver (Canada)); Morris, M.A.; Malcolm, S.

    1993-09-01

    Thirty-two cases of uniparental disomy (UPD), ascertained from Prader-Willi syndrome patients (N=27) and Angelman syndrome patients (N-5), are used to investigate the pattern of recombination associated with nondisjunction of chromosome 15. In addition, the meiotic stage of nondisjunction is inferred by using markers mapping near the centromere. Two basic approaches to the analysis of recombination in specific pairwise intervals along the chromosome. This method shows a significant reduction in recombination for two of five intervals examined. Second, the observed frequency of each recombinant class (i.e., zero, one, two, three, or more observable crossovers) is compared with expected values. This is useful for testing whether the reduction in recombination can be attributed solely to a proportion of cases with no recombination at all (because of asynapsis), with the remaining groups showing normal recombination (or even excess recombination), or whether recombination is uniformly reduced. Analysis of maternal UPD(15) data shows a slight reduction in the multiple-recombinant classes, with a corresponding increase in both the zero- and one-recombinant classes over expected values. The majority, more than 82%, of the extra chromosomes in maternal UPD(15) cases are due to meiotic I nondisjunction events. In contrast, more paternal UPD(15) cases so far examined appear to have a postzygotic origin of the extra paternal chromosome. 33 refs., 1 fig., 7 tabs.

  13. Consequences of recombination on traditional phylogenetic analysis

    DEFF Research Database (Denmark)

    Schierup, M H; Hein, J

    2000-01-01

    We investigate the shape of a phylogenetic tree reconstructed from sequences evolving under the coalescent with recombination. The motivation is that evolutionary inferences are often made from phylogenetic trees reconstructed from population data even though recombination may well occur (mt......DNA or viral sequences) or does occur (nuclear sequences). We investigate the size and direction of biases when a single tree is reconstructed ignoring recombination. Standard software (PHYLIP) was used to construct the best phylogenetic tree from sequences simulated under the coalescent with recombination....... With recombination present, the length of terminal branches and the total branch length are larger, and the time to the most recent common ancestor smaller, than for a tree reconstructed from sequences evolving with no recombination. The effects are pronounced even for small levels of recombination that may...

  14. Chemical inactivation of recombinant vaccinia viruses and the effects on antigenicity and immunogenicity of recombinant simian immunodeficiency virus envelope glycoproteins.

    NARCIS (Netherlands)

    E.G.J. Hulskotte (Ellen); M.E.M. Dings (Marlinda); S.G. Norley (Stephen); A.D.M.E. Osterhaus (Albert)

    1997-01-01

    textabstractThe efficiency of paraformaldehyde (PFA) and binary ethylenimine (BEI) in inactivating recombinant vaccinia virus (rVV), present in baby hamster kidney cells expressing simian immunodeficiency virus envelope glycoproteins (SIV-Env), was measured in a series of inactivation studies. Both

  15. Important Nearby Galaxies without Accurate Distances

    Science.gov (United States)

    McQuinn, Kristen

    2014-10-01

    The Spitzer Infrared Nearby Galaxies Survey (SINGS) and its offspring programs (e.g., THINGS, HERACLES, KINGFISH) have resulted in a fundamental change in our view of star formation and the ISM in galaxies, and together they represent the most complete multi-wavelength data set yet assembled for a large sample of nearby galaxies. These great investments of observing time have been dedicated to the goal of understanding the interstellar medium, the star formation process, and, more generally, galactic evolution at the present epoch. Nearby galaxies provide the basis for which we interpret the distant universe, and the SINGS sample represents the best studied nearby galaxies.Accurate distances are fundamental to interpreting observations of galaxies. Surprisingly, many of the SINGS spiral galaxies have numerous distance estimates resulting in confusion. We can rectify this situation for 8 of the SINGS spiral galaxies within 10 Mpc at a very low cost through measurements of the tip of the red giant branch. The proposed observations will provide an accuracy of better than 0.1 in distance modulus. Our sample includes such well known galaxies as M51 (the Whirlpool), M63 (the Sunflower), M104 (the Sombrero), and M74 (the archetypal grand design spiral).We are also proposing coordinated parallel WFC3 UV observations of the central regions of the galaxies, rich with high-mass UV-bright stars. As a secondary science goal we will compare the resolved UV stellar populations with integrated UV emission measurements used in calibrating star formation rates. Our observations will complement the growing HST UV atlas of high resolution images of nearby galaxies.

  16. Precise and Accurate Density Determination of Explosives Using Hydrostatic Weighing

    Energy Technology Data Exchange (ETDEWEB)

    B. Olinger

    2005-07-01

    Precise and accurate density determination requires weight measurements in air and water using sufficiently precise analytical balances, knowledge of the densities of air and water, knowledge of thermal expansions, availability of a density standard, and a method to estimate the time to achieve thermal equilibrium with water. Density distributions in pressed explosives are inferred from the densities of elements from a central slice.

  17. Fast and Accurate Residential Fire Detection Using Wireless Sensor Networks

    NARCIS (Netherlands)

    Bahrepour, M.; Meratnia, Nirvana; Havinga, Paul J.M.

    2010-01-01

    Prompt and accurate residential fire detection is important for on-time fire extinguishing and consequently reducing damages and life losses. To detect fire sensors are needed to measure the environmental parameters and algorithms are required to decide about occurrence of fire. Recently, wireless

  18. Novel multi-beam radiometers for accurate ocean surveillance

    DEFF Research Database (Denmark)

    Cappellin, C.; Pontoppidan, K.; Nielsen, P. H.

    2014-01-01

    Novel antenna architectures for real aperture multi-beam radiometers providing high resolution and high sensitivity for accurate sea surface temperature (SST) and ocean vector wind (OVW) measurements are investigated. On the basis of the radiometer requirements set for future SST/OVW missions...

  19. Dynamic weighing for accurate fertilizer application and monitoring

    NARCIS (Netherlands)

    Bergeijk, van J.; Goense, D.; Willigenburg, van L.G.; Speelman, L.

    2001-01-01

    The mass flow of fertilizer spreaders must be calibrated for the different types of fertilizers used. To obtain accurate fertilizer application manual calibration of actual mass flow must be repeated frequently. Automatic calibration is possible by measurement of the actual mass flow, based on

  20. Electronic ampere-hour integrator is accurate to one percent

    Science.gov (United States)

    Paulkovich, J.

    1965-01-01

    Electronic ampere-hour integrator is based on current-to-frequency conversion. It operates on low power and is accurate to one percent. This device can measure the ampere-hour capacity of batteries and can be adapted for other functions.

  1. Use of Recombination-Mediated Genetic Engineering for Construction of Rescue Human Cytomegalovirus Bacterial Artificial Chromosome Clones

    Directory of Open Access Journals (Sweden)

    Kalpana Dulal

    2012-01-01

    Full Text Available Bacterial artificial chromosome (BAC technology has contributed immensely to manipulation of larger genomes in many organisms including large DNA viruses like human cytomegalovirus (HCMV. The HCMV BAC clone propagated and maintained inside E. coli allows for accurate recombinant virus generation. Using this system, we have generated a panel of HCMV deletion mutants and their rescue clones. In this paper, we describe the construction of HCMV BAC mutants using a homologous recombination system. A gene capture method, or gap repair cloning, to seize large fragments of DNA from the virus BAC in order to generate rescue viruses, is described in detail. Construction of rescue clones using gap repair cloning is highly efficient and provides a novel use of the homologous recombination-based method in E. coli for molecular cloning, known colloquially as recombineering, when rescuing large BAC deletions. This method of excising large fragments of DNA provides important prospects for in vitro homologous recombination for genetic cloning.

  2. Steady-state photoluminescent excitation characterization of semiconductor carrier recombination

    Energy Technology Data Exchange (ETDEWEB)

    Bhosale, J. S. [Intel Corporation, Hillsboro, Oregon 97124 (United States); Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Moore, J. E.; Wang, X.; Bermel, P.; Lundstrom, M. S. [Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2016-01-15

    Photoluminescence excitation spectroscopy is a contactless characterization technique that can provide valuable information about the surface and bulk recombination parameters of a semiconductor device, distinct from other sorts of photoluminescent measurements. For this technique, a temperature-tuned light emitting diode (LED) has several advantages over other light sources. The large radiation density offered by LEDs from near-infrared to ultraviolet region at a low cost enables efficient and fast photoluminescence measurements. A simple and inexpensive LED-based setup facilitates measurement of surface recombination velocity and bulk Shockley-Read-Hall lifetime, which are key parameters to assess device performance. Under the right conditions, this technique can also provide a contactless way to measure the external quantum efficiency of a solar cell.

  3. Influence of sequence identity and unique breakpoints on the frequency of intersubtype HIV-1 recombination

    Directory of Open Access Journals (Sweden)

    Abreha Measho

    2006-12-01

    Full Text Available Abstract Background HIV-1 recombination between different subtypes has a major impact on the global epidemic. The generation of these intersubtype recombinants follows a defined set of events starting with dual infection of a host cell, heterodiploid virus production, strand transfers during reverse transcription, and then selection. In this study, recombination frequencies were measured in the C1-C4 regions of the envelope gene in the presence (using a multiple cycle infection system and absence (in vitro reverse transcription and single cycle infection systems of selection for replication-competent virus. Ugandan subtypes A and D HIV-1 env sequences (115-A, 120-A, 89-D, 122-D, 126-D were employed in all three assay systems. These subtypes co-circulate in East Africa and frequently recombine in this human population. Results Increased sequence identity between viruses or RNA templates resulted in increased recombination frequencies, with the exception of the 115-A virus or RNA template. Analyses of the recombination breakpoints and mechanistic studies revealed that the presence of a recombination hotspot in the C3/V4 env region, unique to 115-A as donor RNA, could account for the higher recombination frequencies with the 115-A virus/template. Single-cycle infections supported proportionally less recombination than the in vitro reverse transcription assay but both systems still had significantly higher recombination frequencies than observed in the multiple-cycle virus replication system. In the multiple cycle assay, increased replicative fitness of one HIV-1 over the other in a dual infection dramatically decreased recombination frequencies. Conclusion Sequence variation at specific sites between HIV-1 isolates can introduce unique recombination hotspots, which increase recombination frequencies and skew the general observation that decreased HIV-1 sequence identity reduces recombination rates. These findings also suggest that the majority of

  4. Detection of biomarkers using recombinant antibodies coupled to nanostructured platforms

    Directory of Open Access Journals (Sweden)

    Michael R. Kierny

    2012-07-01

    Full Text Available The utility of biomarker detection in tomorrow's personalized health care field will mean early and accurate diagnosis of many types of human physiological conditions and diseases. In the search for biomarkers, recombinant affinity reagents can be generated to candidate proteins or post-translational modifications that differ qualitatively or quantitatively between normal and diseased tissues. The use of display technologies, such as phage-display, allows for manageable selection and optimization of affinity reagents for use in biomarker detection. Here we review the use of recombinant antibody fragments, such as scFvs and Fabs, which can be affinity-selected from phage-display libraries, to bind with both high specificity and affinity to biomarkers of cancer, such as Human Epidermal growth factor Receptor 2 (HER2 and Carcinoembryonic antigen (CEA. We discuss how these recombinant antibodies can be fabricated into nanostructures, such as carbon nanotubes, nanowires, and quantum dots, for the purpose of enhancing detection of biomarkers at low concentrations (pg/mL within complex mixtures such as serum or tissue extracts. Other sensing technologies, which take advantage of ‘Surface Enhanced Raman Scattering’ (gold nanoshells, frequency changes in piezoelectric crystals (quartz crystal microbalance, or electrical current generation and sensing during electrochemical reactions (electrochemical detection, can effectively provide multiplexed platforms for detection of cancer and injury biomarkers. Such devices may soon replace the traditional time consuming ELISAs and Western blots, and deliver rapid, point-of-care diagnostics to market.

  5. Help!!! Theory for H3+ recombination still needed

    Directory of Open Access Journals (Sweden)

    Oka Takeshi

    2015-01-01

    In the meantime, the importance of the DR of in the H3+ diffuse interstellar medium has grown further as astronomical observations of H3+ developed rapidly in the last decade. It has been established that H3+ is the best probe to measure intensities of low energy cosmic rays. The rate constant for the DR of H3+ is crucial in the measurement. We still desperately need the theory for the dissociative recombination of H3+!

  6. Development of an indirect ELISA method for the parallel measurement of IgG and IgM antibodies against Crimean-Congo haemorrhagic fever (CCHF) virus using recombinant nucleoprotein as antigen.

    Science.gov (United States)

    Dowall, S D; Richards, K S; Graham, V A; Chamberlain, J; Hewson, R

    2012-02-01

    Recombinant nucleoprotein from Crimean-Congo Haemorrhagic Fever (CCHF) virus was successfully derived from a baculovirus expression system and purified for use in a novel enzyme-linked immunosorbent assay (ELISA) diagnostic test. Comparable tests were used for detection of IgG and IgM antibodies, thus allowing efficient detection of both antibodies in parallel. The major benefits of the assay also included removing any requirement for polyclonal sera, thus eliminating variation in preparations and allowing standardisation between laboratories. The assay was successfully tested using a panel of positive sera supplied from samples identified as being positive in Turkey, Tajikistan and Kosovo and shown to be sensitive and specific. It is envisaged that this simple diagnostic ELISA for CCHF virus infection which removes the reliance on polyclonal antibody preparations, will be accessible to a wider range of laboratories enabling them to carry out routine diagnosis. This will improve the efficiency of diagnosis and subsequent management of infected patients. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  7. CRMAGE: CRISPR Optimized MAGE Recombineering

    DEFF Research Database (Denmark)

    Ronda, Carlotta; Pedersen, Lasse Ebdrup; Sommer, Morten Otto Alexander

    2016-01-01

    A bottleneck in metabolic engineering and systems biology approaches is the lack of efficient genome engineering technologies. Here, we combine CRISPR/Cas9 and λ Red recombineering based MAGE technology (CRMAGE) to create a highly efficient and fast method for genome engineering of Escherichia coli...... that are assembled by a USER-cloning approach enabling quick and cost efficient gRNA replacement. CRMAGE furthermore utilizes CRISPR/Cas9 for efficient plasmid curing, thereby enabling multiple engineering rounds per day. To facilitate the design process, a web-based tool was developed to predict both the λ Red...

  8. Mass spectrometric analysis of innovator, counterfeit, and follow-on recombinant human growth hormone.

    Science.gov (United States)

    Jiang, Haitao; Wu, Shiaw-Lin; Karger, Barry L; Hancock, William S

    2009-01-01

    We have performed a detailed characterization of recombinant human growth hormone that included the identification of the entire sequence with disulfide linkages as well as subtle modifications by a sensitive liquid chromatography coupled online with tandem mass spectrometry (LC-MS) approach using the accurate peptide mass (FTICR MS) and sequence assignment (MS/MS measurement). The extent of oxidation, deamidation, and chain cleavages were measured by the ratio of peak areas of the nonmodified peptide vs. the sum of peak area of the nonmodified and modified peptides in the same LC-MS analysis. The subtle but distinct differences were found in the recombinant human growth from the three manufacturers (the follow-on, counterfeit, and the original innovator products). In relative comparison, the follow-on product had the highest degree of oxidation at methionine residues, followed by the counterfeit product, and the original innovator product had the least amount of oxidation at all three sites with the similar oxidation order. In cases, the oxidation order was Met14 > Met125 > Met170. In contrast, the follow-on had the least amount of deamidation at aspargine (Asn149), and the counterfeit had the highest degree of deamidation at this site. For the chain cleavage, the follow-on product had the highest cleavage occurring at T 10 peptide (between Asn99 and Ser100), the counterfeit had the highest cleavage on T4 peptide, (between Glu30 and Phe31), and the original innovator product with the least amount of cleavages on both sites. These subtle but distinct differences are likely because of nonidentical manufacturing, formulation procedures, and storage conditions.

  9. Optimizing cell arrays for accurate functional genomics.

    Science.gov (United States)

    Fengler, Sven; Bastiaens, Philippe I H; Grecco, Hernán E; Roda-Navarro, Pedro

    2012-07-17

    Cellular responses emerge from a complex network of dynamic biochemical reactions. In order to investigate them is necessary to develop methods that allow perturbing a high number of gene products in a flexible and fast way. Cell arrays (CA) enable such experiments on microscope slides via reverse transfection of cellular colonies growing on spotted genetic material. In contrast to multi-well plates, CA are susceptible to contamination among neighboring spots hindering accurate quantification in cell-based screening projects. Here we have developed a quality control protocol for quantifying and minimizing contamination in CA. We imaged checkered CA that express two distinct fluorescent proteins and segmented images into single cells to quantify the transfection efficiency and interspot contamination. Compared with standard procedures, we measured a 3-fold reduction of contaminants when arrays containing HeLa cells were washed shortly after cell seeding. We proved that nucleic acid uptake during cell seeding rather than migration among neighboring spots was the major source of contamination. Arrays of MCF7 cells developed without the washing step showed 7-fold lower percentage of contaminant cells, demonstrating that contamination is dependent on specific cell properties. Previously published methodological works have focused on achieving high transfection rate in densely packed CA. Here, we focused in an equally important parameter: The interspot contamination. The presented quality control is essential for estimating the rate of contamination, a major source of false positives and negatives in current microscopy based functional genomics screenings. We have demonstrated that a washing step after seeding enhances CA quality for HeLA but is not necessary for MCF7. The described method provides a way to find optimal seeding protocols for cell lines intended to be used for the first time in CA.