Science.gov

Sample records for resonance parameter evaluations

  1. Evaluation of Silicon Neutron Resonance Parameters in the Energy Range Thermal to 1800 keV

    SciTech Connect

    Derrien, H.

    2002-09-30

    The evaluation of the neutron cross sections of the three stable isotopes of silicon in the energy range thermal to 20 MeV was performed by Hetrick et al. for ENDF/B-VI (Evaluated Nuclear Data File). Resonance parameters were obtained in the energy range thermal to 1500 keV from a SAMMY analysis of the Oak Ridge National Laboratory experimental neutron transmission data. A new measurement of the capture cross section of natural silicon in the energy range 1 to 700 keV has recently been performed at the Oak Ridge Electron Linear Accelerator. Results of this measurement were used in a SAMMY reevaluation of the resonance parameters, allowing determination of the capture width of a large number of resonances. The experimental data base is described; properties of the resonance parameters are given. For the first time the direct neutron capture component has been taken into account from the calculation by Rauscher et al. in the energy range from thermal to 1 MeV. Results of benchmark calculations are also given. The new evaluation is available in the ENDF/B-VI format.

  2. Resonance Parameter Adjustment Based on Integral Experiments

    DOE PAGESBeta

    Sobes, Vladimir; Leal, Luiz; Arbanas, Goran; Forget, Benoit

    2016-06-02

    Our project seeks to allow coupling of differential and integral data evaluation in a continuous-energy framework and to use the generalized linear least-squares (GLLS) methodology in the TSURFER module of the SCALE code package to update the parameters of a resolved resonance region evaluation. We recognize that the GLLS methodology in TSURFER is identical to the mathematical description of a Bayesian update in SAMMY, the SAMINT code was created to use the mathematical machinery of SAMMY to update resolved resonance parameters based on integral data. Traditionally, SAMMY used differential experimental data to adjust nuclear data parameters. Integral experimental data, suchmore » as in the International Criticality Safety Benchmark Experiments Project, remain a tool for validation of completed nuclear data evaluations. SAMINT extracts information from integral benchmarks to aid the nuclear data evaluation process. Later, integral data can be used to resolve any remaining ambiguity between differential data sets, highlight troublesome energy regions, determine key nuclear data parameters for integral benchmark calculations, and improve the nuclear data covariance matrix evaluation. Moreover, SAMINT is not intended to bias nuclear data toward specific integral experiments but should be used to supplement the evaluation of differential experimental data. Using GLLS ensures proper weight is given to the differential data.« less

  3. Neutron Resonance Parameters for Ra-226 (Radium)

    NASA Astrophysics Data System (ADS)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Volume 24 `Neutron Resonance Parameters' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides the neutron resonance parameters for the isotope Ra-226 (Radium).

  4. Integral data analysis for resonance parameters determination

    SciTech Connect

    Larson, N.M.; Leal, L.C.; Derrien, H.

    1997-09-01

    Neutron time-of-flight experiments have long been used to determine resonance parameters. Those resonance parameters have then been used in calculations of integral quantities such as Maxwellian averages or resonance integrals, and results of those calculations in turn have been used as a criterion for acceptability of the resonance analysis. However, the calculations were inadequate because covariances on the parameter values were not included in the calculations. In this report an effort to correct for that deficiency is documented: (1) the R-matrix analysis code SAMMY has been modified to include integral quantities of importance, (2) directly within the resonance parameter analysis, and (3) to determine the best fit to both differential (microscopic) and integral (macroscopic) data simultaneously. This modification was implemented because it is expected to have an impact on the intermediate-energy range that is important for criticality safety applications.

  5. Rho resonance parameters from lattice QCD

    NASA Astrophysics Data System (ADS)

    Guo, Dehua; Alexandru, Andrei; Molina, Raquel; Döring, Michael

    2016-08-01

    We perform a high-precision calculation of the phase shifts for π -π scattering in the I =1 , J =1 channel in the elastic region using elongated lattices with two mass-degenerate quark flavors (Nf=2 ). We extract the ρ resonance parameters using a Breit-Wigner fit at two different quark masses, corresponding to mπ=226 MeV and mπ=315 MeV , and perform an extrapolation to the physical point. The extrapolation is based on a unitarized chiral perturbation theory model that describes well the phase shifts around the resonance for both quark masses. We find that the extrapolated value, mρ=720 (1 )(15 ) MeV , is significantly lower that the physical rho mass and we argue that this shift could be due to the absence of the strange quark in our calculation.

  6. Resonance parameter measurements and analysis of gadolinium

    SciTech Connect

    Leinweber, G.; Barry, D. P.; Trbovich, M. J.; Burke, J. A.; Drindak, N. J.; Knox, H. D.; Ballad, R. V.; Block, R. C.; Danon, Y.; Severnyak, L. I.

    2006-07-01

    The purpose of the present work is to measure the neutron cross sections of gadolinium accurately. Gd has the highest thermal absorption cross section of any natural element. Therefore it is an important element for thermal reactor applications Neutron capture and transmission measurements were performed by the time-of-flight technique at the Rensselaer Polytechnic Inst. (RPI) LINAC facility using metallic and liquid Gd samples. The liquid samples were isotopically-enriched in either {sup 155}Gd or {sup 157}Gd. The capture measurements were made at the 25-m flight station with a sodium iodide detector, and the transmission measurements were performed at 15- and 25-m flight stations with {sup 6}Li glass scintillation detectors. The multilevel R-matrix Bayesian code SAMMY was used to extract resonance parameters. The results of the thermal region analysis are significant. Resonance parameters for the low energy doublet, at 0.025 and 0.032 eV, are presented. The thermal (2200 m/s) capture cross section of {sup 157}Gd has been measured to be 11% smaller than that calculated from ENDF/B-VI updated through release 8. Thermal capture cross sections and capture resonance integrals for each isotope as well as elemental gadolinium are presented. In the epithermal region, natural metal samples were measured in capture and transmission. Neutron interaction data up to 300 eV have been analyzed. Substantial improvement to the understanding of gadolinium cross sections is presented, particularly above 180 eV where the ENDF resolved region for {sup 155}Gd ends. (authors)

  7. Systematics of Hot Giant Dipole Resonance Parameters

    NASA Astrophysics Data System (ADS)

    Schiller, Andreas; Thoennessen, Michael; McAlpine, Katherine

    2008-10-01

    The dependence of the Giant Dipole Resonance (GDR) width on spin and temperature is a much debated subject in the literature. A universal scaling law has been proposed by Kusnezov et al. [D. Kusnezov et al. Phys. Rev. Lett. 81,42 (1998)]@. Recently, we completed a literature survey of GDR parameters which provided us with a data set about five times as big as the one which was used by Kusnezov et al. [A. Schiller and M. Thoennessen, At. Data Nucl. Data Tables 93,49 (2007)]@. The Kusnezov scaling law is tested over this larger data set. The data is also broken down into subsets of data with common characteristics such as deformation. We will discuss the limits of applicability of the Kusnezov scaling law.

  8. RESONANT EXTRACTION PARAMETERS FOR THE AGS BOOSTER.

    SciTech Connect

    BROWN,K.A.; CULLEN,J.; GLENN,J.W.; MAPES,M.; MARNERIS,I.; TSOUPAS,N.; SNYDSTRUP,L.; VAN ASSELT,W.

    2001-06-18

    Brookhaven's AGS Booster is the injector for the AGS. It is being modified to send resonant extracted heavy ions to a new beam line, the Booster Applications Facility (BAF). The design of the resonant extraction system for BAF was described in [1]. This note will give a more detailed description of the system and describe the predicted resonant beam time structure. We will describe tune space manipulations necessary to extract the resonant beam at the maximum Booster rigidity, schemes for performing resonant extraction, and describe the modifications required to perform bunched beam extraction to the BAF facility.

  9. Single-level resonance parameters fit nuclear cross-sections

    NASA Technical Reports Server (NTRS)

    Drawbaugh, D. W.; Gibson, G.; Miller, M.; Page, S. L.

    1970-01-01

    Least squares analyses of experimental differential cross-section data for the U-235 nucleus have yielded single level Breit-Wigner resonance parameters that fit, simultaneously, three nuclear cross sections of capture, fission, and total.

  10. 239Pu Resonance Evaluation for Thermal Benchmark System Calculations

    NASA Astrophysics Data System (ADS)

    Leal, L. C.; Noguere, G.; de Saint Jean, C.; Kahler, A. C.

    2014-04-01

    Analyses of thermal plutonium solution critical benchmark systems have indicated a deficiency in the 239Pu resonance evaluation. To investigate possible solutions to this issue, the Organisation for Economic Co-operation and Development (OECD) Nuclear Energy Agency (NEA) Working Party for Evaluation Cooperation (WPEC) established Subgroup 34 to focus on the reevaluation of the 239Pu resolved resonance parameters. In addition, the impacts of the prompt neutron multiplicity (νbar) and the prompt neutron fission spectrum (PFNS) have been investigated. The objective of this paper is to present the results of the 239Pu resolved resonance evaluation effort.

  11. Measurement of the parameters of the psi(3770) resonance

    SciTech Connect

    Schindler, R.H.; Siegrist, J.L.; Alam, M.S.; Boyarski, A.M.; Breidenbach, M.; Burke, D.L.; Dorenbosch, J.; Dorfan, J.M.; Feldman, G.J.; Franklin, M.E.B.; Hanson, G.; Hayes, K.G.; Himel, T.; Hitlin, D.G.; Hollebeek, R.J.; Innes, W.R.; Jaros, J.A.; Jenni, P.; Larsen, R.R.; Lueth, V.; Perl, M.L.; Richter, B.; Scharre, D.L.; Schwitters, R.F.; Taureg, H.; Tonutti, M.; Vidal, R.A.; Weiss, J.M.; Zaccone, H.; Abrams, G.S.; Blocker, C.A.; Carithers, W.C.; Chinowsky, W.; Coles, M.W.; Cooper, S.; Dieterle, W.E.; Dillon, J.B.; Eaton, M.W.; Gidal, G.; Goldhaber, G.; Johnson, A.D.; Kadyk, J.A.; Lankford, A.J.; Millikan, R.E.; Nelson, M.E.; Pang, C.Y.; Patrick, J.F.; Strait, J.; Trilling, G.H.; Vella, E.N.; Videau, I.

    1980-05-01

    We present a measurement of the cross section for hadron production by e/sup +/e/sup -/ annihilation in the vicinity of the previously observed resonance near 3.77 GeV. The data are used to determine the parameters of the psi(3770) resonance. The values found are: mass, 3764 +- 5 MeV/c/sup 2/, total width, 23.5 +- 5 MeV, and partial width to electron pairs, 276 +- 50 eV.

  12. Hafnium Resonance Parameter Analysis Using Neutron Capture and Transmission Experiments

    SciTech Connect

    Trbovich, M J; Barry, D P; Slovacek, R E; Danon, Y; Block, R C; Francis, N C; Lubert, M; Burke, J A; Drindak, N J; Lienweber, G; Ballad, R

    2007-02-06

    The focus of this work is to determine the resonance parameters for stable hafnium isotopes in the 0.005 - 200 eV region, with special emphasis on the overlapping {sup 176}Hf and {sup 178}Hf resonances near 8 eV. Accurate hafnium cross sections and resonance parameters are needed in order to quantify the effects of hafnium found in zirconium, a metal commonly used in reactors. The accuracy of the cross sections and the corresponding resonance parameters used in current nuclear analysis tools are rapidly becoming the limiting factor in reducing the overall uncertainty on reactor physics calculations. Experiments measuring neutron capture and transmission are routinely performed at the Rensselaer Polytechnic Institute (RPI) LINAC using the time-of flight technique. {sup 6}Li glass scintillation detectors were used for transmission experiments at flight path lengths of 15 and 25 m, respectively. Capture experiments were performed using a sixteen section NaI multiplicity detector at a flight path length of 25 m. These experiments utilized several thicknesses of metallic and isotope-enriched liquid Hf samples. The liquid Hf samples were designed to provide information on the {sup 176}Hf and {sup 178}Hf contributions to the 8 eV doublet without saturation. Data analyses were performed using the R-matrix Bayesian code SAMMY. A combined capture and transmission data analysis yielded resonance parameters for all hafnium isotopes from 0.005 - 200 eV. Additionally, resonance integrals were calculated, along with errors for each hafnium isotope, using the NJOY and INTER codes. The isotopic resonance integrals calculated were significantly different than previous values. The {sup 176}Hf resonance integral, based on this work, is approximately 73% higher than the ENDF/B-VI value. This is due primarily to the changes to resonance parameters in the 8 eV resonance, the neutron width presented in this work is more than twice that of the previous value. The calculated elemental

  13. 95Mo nuclear magnetic resonance parameters of molybdenum hexacarbonyl from density functional theory: appraisal of computational and geometrical parameters.

    PubMed

    Cuny, Jérôme; Sykina, Kateryna; Fontaine, Bruno; Le Pollès, Laurent; Pickard, Chris J; Gautier, Régis

    2011-11-21

    Solid-state (95)Mo nuclear magnetic resonance (NMR) properties of molybdenum hexacarbonyl have been computed using density functional theory (DFT) based methods. Both quadrupolar coupling and chemical shift parameters were evaluated and compared with parameters of high precision determined using single-crystal (95)Mo NMR experiments. Within a molecular approach, the effects of major computational parameters, i.e. basis set, exchange-correlation functional, treatment of relativity, have been evaluated. Except for the isotropic parameter of both chemical shift and chemical shielding, computed NMR parameters are more sensitive to geometrical variations than computational details. Relativistic effects do not play a crucial part in the calculations of such parameters for the 4d transition metal, in particular isotropic chemical shift. Periodic DFT calculations were tackled to measure the influence of neighbouring molecules on the crystal structure. These effects have to be taken into account to compute accurate solid-state (95)Mo NMR parameters even for such an inorganic molecular compound.

  14. Measuring the Dielectric Parameters of Frozen Sand in Microwave Resonators

    NASA Astrophysics Data System (ADS)

    Bordonsky, G. S.; Orlov, A. O.; Filippova, T. G.

    2004-04-01

    We measure the dielectric parameters of frozen sand by using a rectangular cavity resonator at frequencies 5.3-8.4 GHz. The transmission spectrum of the resonator completely filled with frozen sand shows supplementary resonances absent in the case where the resonator is filled with dry homogeneous sand. The difference of the resonance curves was observed for the cases of wetting the sand by ordinary (H2O) and heavy (D2O) water. It is supposed that the observed effects are related to percolation due to the existence and specific properties of the conducting liquid films of water on the surfaces of mineral particles. To verify this assumption, we performed measurements for the special medium consisting of a mixture of dry sand and small metal particles. This experiment showed that supplementary resonant peaks in the transmission spectrum of the resonator arise for a certain concentration of metal particles. The same effect is also observed in the case of incomplete filling of the resonator with dry sand. These anomalies can be explained by the appearance of negative dispersion of waves in the waveguide.

  15. Neutron Resonance Parameters and Covariance Matrix of 239Pu

    SciTech Connect

    Derrien, Herve; Leal, Luiz C; Larson, Nancy M

    2008-08-01

    In order to obtain the resonance parameters in a single energy range and the corresponding covariance matrix, a reevaluation of 239Pu was performed with the code SAMMY. The most recent experimental data were analyzed or reanalyzed in the energy range thermal to 2.5 keV. The normalization of the fission cross section data was reconsidered by taking into account the most recent measurements of Weston et al. and Wagemans et al. A full resonance parameter covariance matrix was generated. The method used to obtain realistic uncertainties on the average cross section calculated by SAMMY or other processing codes was examined.

  16. Studying the ρ resonance parameters with staggered fermions

    NASA Astrophysics Data System (ADS)

    Fu, Ziwen; Wang, Lingyun

    2016-08-01

    We deliver a lattice study of ρ resonance parameters with p -wave π π scattering phases, which are extracted by finite-size methods at one center-of-mass frame and four moving frames for six lattice ensembles from the MILC Collaboration with pion masses ranging from 346 to 176 MeV. The effective range formula is applied to describe the scattering phases as a function of the energy covering the resonance region; this allows us to extract ρ resonance parameters and to investigate the quark-mass dependence. Lattice studies with three flavors of Asqtad-improved staggered fermions enable us to use the moving-wall source technique on large lattice spatial dimensions (L =64 ) and small light u /d quarks. Numerical computations are carried out at two lattice spacings, a ≈0.12 and 0.09 fm.

  17. Determination of Resonance Parameters and their Covariances from Neutron Induced Reaction Cross Section Data

    SciTech Connect

    Schillebeeckx, P.; Becker, B.; Danon, Y.; Guber, K.; Harada, H.; Heyse, J.; Junghans, A.R.; Kopecky, S.; Massimi, C.; Moxon, M.C.; Otuka, N.; Sirakov, I.; Volev, K.

    2012-12-15

    Cross section data in the resolved and unresolved resonance region are represented by nuclear reaction formalisms using parameters which are determined by fitting them to experimental data. Therefore, the quality of evaluated cross sections in the resonance region strongly depends on the experimental data used in the adjustment process and an assessment of the experimental covariance data is of primary importance in determining the accuracy of evaluated cross section data. In this contribution, uncertainty components of experimental observables resulting from total and reaction cross section experiments are quantified by identifying the metrological parameters involved in the measurement, data reduction and analysis process. In addition, different methods that can be applied to propagate the covariance of the experimental observables (i.e. transmission and reaction yields) to the covariance of the resonance parameters are discussed and compared. The methods being discussed are: conventional uncertainty propagation, Monte Carlo sampling and marginalization. It is demonstrated that the final covariance matrix of the resonance parameters not only strongly depends on the type of experimental observables used in the adjustment process, the experimental conditions and the characteristics of the resonance structure, but also on the method that is used to propagate the covariances. Finally, a special data reduction concept and format is presented, which offers the possibility to store the full covariance information of experimental data in the EXFOR library and provides the information required to perform a full covariance evaluation.

  18. Hafnium Resonance Parameter Analysis using Neutron Capture and Transmission Experiments

    SciTech Connect

    Trbovich, Michael J.; Barry, Devin P.; Burke, John A.; Drindak, Noel J.; Leinweber, Greg; Ballad, Robert V.; Slovacek, Rudy E.; Danon, Yaron; Block, Robert C.

    2005-05-24

    The focus of this work is to determine resonance parameters for stable hafnium isotopes in the 0.005-200 eV region, with special emphasis on the overlapping 176Hf and 178Hf resonances near 8 eV. The large neutron cross section of hafnium, combined with its corrosion resistance and excellent mechanical properties, make it a useful material for controlling nuclear reactions.Experiments measuring neutron capture and transmission were performed at the Rensselaer Polytechnic Institute (RPI) electron linear accelerator (LINAC) using the time of flight method. 6Li glass scintillation detectors were used for transmission experiments at flight path lengths of 15 and 25 m. Capture experiments were done using a sixteen-section NaI(Tl) multiplicity detector at a flight path length of 25 m. These experiments utilized various thicknesses of metallic and isotopically enriched liquid samples. The liquid samples were designed to provide information on the 176Hf and 178Hf contributions to the 8-eV doublet without saturation.Data analysis was done using the R-matrix Bayesian code SAMMY version M6 beta. SAMMY is able to account for experimental resolution effects for each of the experimental setups at the RPI LINAC, and also can correct for multiple scattering effects in neutron capture yield data. The combined capture and transmission data analysis yielded resonance parameters for all hafnium isotopes from 0.005-200 eV. Resonance integrals were calculated along with errors for each hafnium isotope using the NJOY and INTER codes. The isotopic resonance integrals calculated were significantly different than previously published values; however the calculated elemental hafnium resonance integral changed very little.

  19. Statistical parameters for gloss evaluation

    SciTech Connect

    Peiponen, Kai-Erik; Juuti, Mikko

    2006-02-13

    The measurement of minute changes in local gloss has not been presented in international standards due to a lack of suitable glossmeters. The development of a diffractive-element-based glossmeter (DOG) made it possible to detect local variation of gloss from planar and complex-shaped surfaces. Hence, a demand for proper statistical gloss parameters for classifying surface quality by gloss, similar to the standardized surface roughness classification, has become necessary. In this letter, we define statistical gloss parameters and utilize them as an example in the characterization of gloss from metal surface roughness standards by the DOG.

  20. Evaluation and Treatment of Resonance Disorders.

    ERIC Educational Resources Information Center

    Kummer, Ann W.; Lee, Linda

    1996-01-01

    Resonance disorders can have a variety of causes but the appropriate evaluation includes a speech pathology evaluation and may require a videofluoroscopic speech study or nasopharyngoscopy assessment. Treatment may include surgery or the use of prosthetic devices, and usually speech therapy. An interdisciplinary approach is best. (Author/DB)

  1. On the Methodology to Calculate the Covariance of Estimated Resonance Parameters

    SciTech Connect

    Becker, B.; Kopecky, S.; Schillebeeckx, P.

    2015-01-15

    Principles to determine resonance parameters and their covariance from experimental data are discussed. Different methods to propagate the covariance of experimental parameters are compared. A full Bayesian statistical analysis reveals that the level to which the initial uncertainty of the experimental parameters propagates, strongly depends on the experimental conditions. For high precision data the initial uncertainties of experimental parameters, like a normalization factor, has almost no impact on the covariance of the parameters in case of thick sample measurements and conventional uncertainty propagation or full Bayesian analysis. The covariances derived from a full Bayesian analysis and least-squares fit are derived under the condition that the model describing the experimental observables is perfect. When the quality of the model can not be verified a more conservative method based on a renormalization of the covariance matrix is recommended to propagate fully the uncertainty of experimental systematic effects. Finally, neutron resonance transmission analysis is proposed as an accurate method to validate evaluated data libraries in the resolved resonance region.

  2. Comments on extracting the resonance strength parameter from yield data

    NASA Astrophysics Data System (ADS)

    Croft, Stephen; Favalli, Andrea

    2015-10-01

    The F(α,n) reaction is the focus of on-going research in part because it is an important source of neutrons in the nuclear fuel cycle which can be exploited to assay nuclear materials, especially uranium in the form of UF6 [1,2]. At the present time there remains some considerable uncertainty (of the order of ±20%) in the thick target integrated over angle (α,n) yield from 19F (100% natural abundance) and its compounds as discussed in [3,4]. An important thin target cross-section measurement is that of Wrean and Kavanagh [5] who explore the region from below threshold (2.36 MeV) to approximately 3.1 MeV with fine energy resolution. Integration of their cross-section data over the slowing down history of a stopping α-particle allows the thick target yield to be calculated for incident energies up to 3.1 MeV. This trend can then be combined with data from other sources to obtain a thick target yield curve over the wider range of interest to the fuel cycle (roughly threshold to 10 MeV to include all relevant α-emitters). To estimate the thickness of the CaF2 target they used, Wrean and Kavanagh separately measured the integrated yield of the 6.129 MeV γ-rays from the resonance at 340.5 keV (laboratory α-particle kinetic energy) in the 19F(p,αγ) reaction. To interpret the data they adopted a resonance strength parameter of (22.3±0.8) eV based on a determination by Becker et al [6]. The value and its uncertainty directly affects the thickness estimate and the extracted (α,n) cross-section values. In their citation to Becker et al's work, Wrean and Kavanagh comment that they did not make use of an alternative value of (23.7±1.0) eV reported by Croft [7] because they were unable to reproduce the value from the data given in that paper. The value they calculated for the resonance strength from the thick target yield given by Croft was 21.4 eV. The purpose of this communication is to revisit the paper by Croft published in this journal and specifically to

  3. Modification of piezoelectric vibratory gyroscope resonator parameters by feedback control.

    PubMed

    Loveday, P W; Rogers, C A

    1998-01-01

    A method for analyzing the effect of feedback control on the dynamics of piezoelectric resonators used in vibratory gyroscopes has been developed. This method can be used to determine the feasibility of replacing the traditional mechanical balancing operations, used to adjust the resonant frequency, by displacement feedback and for determining the velocity feedback required to produce a particular bandwidth. Experiments were performed on a cylindrical resonator with discrete piezoelectric actuation and sensing elements to demonstrate the principles. Good agreement between analysis and experiment was obtained, and it was shown that this type of resonator could be balanced by displacement feedback. The analysis method presented also is applicable to micromachined piezoelectric gyroscopes. PMID:18244281

  4. R-MATRIX RESONANCE ANALYSIS AND STATISTICAL PROPERTIES OF THE RESONANCE PARAMETERS OF 233U IN THE NEUTRON ENERGY RANGE FROM THERMAL TO 600 eV

    SciTech Connect

    Leal, L.C.

    2001-02-27

    The R-matrix resonance analysis of experimental neutron transmission and cross sections of {sup 233}U, with the Reich-Moore Bayesian code SAMMY, was extended up to the neutron energy of 600 eV by taking advantage of new high resolution neutron transmission and fission cross section measurements performed at the Oak Ridge Electron Linear Accelerator (ORELA). The experimental data base is described. In addition to the microscopic data (time-of-flight measurements of transmission and cross sections), some experimental and evaluated integral quantities were included in the data base. Tabulated and graphical comparisons between the experimental data and the SAMMY calculated cross sections are given. The ability of the calculated cross sections to reproduce the effective multiplication factors k{sub eff} for various thermal, intermediate, and fast systems was tested. The statistical properties of the resonance parameters were examined and recommended values of the average s-wave resonance parameters are given.

  5. Evaluation of Tungsten Neutron Cross Sections in the Resolved Resonance Regions

    SciTech Connect

    Pigni, Marco T; Leal, Luiz C; Dunn, Michael E; Guber, Klaus H; Emiliani, F.; Kopecky, S.; Lampoudis, C.; Schillebeeckx, P.; Siegler, P.

    2014-01-01

    We generated a preliminary set of resonance parameters for 182-184,186W in the neutron energy range of thermal up to several keV. The evaluation methodology uses the Reich-Moore approximation to t, with the R-matrix code SAMMY, the high-resolution measurements performed in 2010 and 2012 at the GEel LINear Accelerator (GELINA) facility. Particularly for 183W, the transmission data and the capture cross sections calculated with the set of resonance parameters are compared with the experimental values, and some of the average properties of the resonance parameters are discussed. In the analyzed energy range, this work almost doubles the existing resolved resonance evaluations in the ENDF/B-VII.1 library. The analysis of the performance of the calculated cross sections based on criticality benchmarks is still in progress and it is only briefly discussed.

  6. Evaluation of Tungsten Neutron Cross Sections in the Resolved Resonance Region

    NASA Astrophysics Data System (ADS)

    Pigni, M. T.; Leal, L. C.; Dunn, M. E.; Guber, K. H.; Trkov, A.; Žerovnik, G.; Emiliani, F.; Kopecky, S.; Lampoudis, C.; Schillebeeckx, P.; Siegler, P.

    2014-04-01

    We generated a preliminary set of resonance parameters for 182,183,184,186W in the neutron energy range of thermal up to several keV. The evaluation methodology uses the Reich-Moore approximation to fit with the R-matrix code SAMMY, the high-resolution measurements performed in 2010 and 2012 at the Geel linear accelerator facility. For 183W, the transmission data and capture cross sections calculated with the set of resonance parameters are compared with the experimental values, and some of the average properties of the resonance parameters are discussed. In the analyzed energy range, this work almost doubles the existing resolved resonance evaluations in the ENDF/B-VII.1 library. A preliminary analysis of the performance of the calculated cross sections based on Lead slowing-down benchmarks is presented and briefly discussed.

  7. Chronic liver disease: evaluation by magnetic resonance

    SciTech Connect

    Stark, D.D.; Goldberg, H.I.; Moss, A.A.; Bass, N.M.

    1984-01-01

    Magnetic resonance (MR) imaging distinguished hepatitis from fatty liver and cirrhosis in a woman with a history of alcohol abuse. Anatomic and physiologic manifestations of portal hypertension were also demonstrated by MR.

  8. Resonance analysis and evaluation of the sup 235 U neutron induced cross sections

    SciTech Connect

    Leal, L.C.

    1990-06-01

    Neutron cross sections of fissile nuclei are of considerable interest for the understanding of parameters such as resonance absorption, resonance escape probability, resonance self-shielding,and the dependence of the reactivity on temperature. In the present study, new techniques for the evaluation of the {sup 235}U neutron cross sections are described. The Reich-Moore formalism of the Bayesian computer code SAMMY was used to perform consistent R-matrix multilevel analyses of the selected neutron cross-section data. The {Delta}{sub 3}-statistics of Dyson and Mehta, along with high-resolution data and the spin-separated fission cross-section data, have provided the possibility of developing a new methodology for the analysis and evaluation of neutron-nucleus cross sections. The results of the analysis consists of a set of resonance parameters which describe the {sup 235}U neutron cross sections up to 500 eV. The set of resonance parameters obtained through a R-matrix analysis are expected to satisfy statistical properties which lead to information on the nuclear structure. The resonance parameters were tested and showed good agreement with the theory. It is expected that the parametrization of the {sub 235}U neutron cross sections obtained in this dissertation represents the current state of art in data as well as in theory and, therefore, can be of direct use in reactor calculations. 44 refs., 21 figs., 8 tabs.

  9. Relativistic calculations of magnetic resonance parameters: background and some recent developments.

    PubMed

    Autschbach, Jochen

    2014-03-13

    This article outlines some basic concepts of relativistic quantum chemistry and recent developments of relativistic methods for the calculation of the molecular properties that define the basic parameters of magnetic resonance spectroscopic techniques, i.e. nuclear magnetic resonance shielding, indirect nuclear spin-spin coupling and electric field gradients (nuclear quadrupole coupling), as well as with electron paramagnetic resonance g-factors and electron-nucleus hyperfine coupling. Density functional theory (DFT) has been very successful in molecular property calculations, despite a number of problems related to approximations in the functionals. In particular, for heavy-element systems, the large electron count and the need for a relativistic treatment often render the application of correlated wave function ab initio methods impracticable. Selected applications of DFT in relativistic calculation of magnetic resonance parameters are reviewed.

  10. Efimov Resonance and Three-Body Parameter in a Lithium-Rubidium Mixture

    NASA Astrophysics Data System (ADS)

    Maier, R. A. W.; Eisele, M.; Tiemann, E.; Zimmermann, C.

    2015-07-01

    We study collisional heating in a cold 7Li-87Rb mixture near a broad Feshbach resonance at 661 G. At the high field slope of the resonance, we find an enhanced three-body recombination rate that we interpret as a heteronuclear Efimov resonance. With improved Feshbach spectroscopy of two further resonances, a model for the molecular potentials has been developed that now consistently explains all known Feshbach resonances of the various Li-Rb isotope mixtures. The model is used to determine the scattering length of the observed Efimov state. Its value of -1870 a0 Bohr radii supports the currently discussed assumption of universality of the three-body parameter also in heteronuclear mixtures.

  11. Radio frequency spectral characterization and model parameters extraction of high Q optical resonators

    PubMed Central

    Abdallah, Zeina; Boucher, Yann G.; Fernandez, Arnaud; Balac, Stéphane; Llopis, Olivier

    2016-01-01

    A microwave domain characterization approach is proposed to determine the properties of high quality factor optical resonators. This approach features a very high precision in frequency and aims to acquire a full knowledge of the complex transfer function (amplitude and phase) characterizing an optical resonator using a microwave vector network analyzer. It is able to discriminate between the different coupling regimes, from the under-coupling to the selective amplification, and it is used together with a model from which the main resonator parameters are extracted, i.e. coupling factor, intrinsic losses, phase slope, intrinsic and external quality factor. PMID:27251460

  12. Anomaly of the rotational nonergodicity parameter of glass formers probed by high field electron paramagnetic resonance

    NASA Astrophysics Data System (ADS)

    Bercu, V.; Martinelli, M.; Massa, C. A.; Pardi, L. A.; Rössler, E. A.; Leporini, D.

    2008-08-01

    Exploiting the high angular resolution of high field electron paramagnetic resonance measured at 95, 190, and 285 GHz we determine the rotational nonergodicity parameter of different probe molecules in the glass former o-terphenyl and polybutadiene in a model-independent way. Our results clearly show a characteristic change in the temperature of the nonergodicity parameter proving a rather sharp dynamic crossover in both systems, in contrast to previous results from other techniques.

  13. 'Coulomb' description of basic relaxation parameters of isobar analog and charge-exchange giant monopole resonances

    SciTech Connect

    Gorelik, M. L.; Rykovanov, V. S.; Urin, M. G.

    2010-12-15

    Within a semimicroscopic approach, basic relaxation parameters of the isobaric analog resonance and of the charge-exchange giant monopole resonance, which is an overtone of the isobaric analog resonance, are interpreted in terms of the mean Coulomb field of a nucleus. The continuum version of the random-phase approximation, allowance for an approximate isospin conservation in nuclei in an explicit form, and a phenomenological description of the fragmentation effect are basic ingredients of the approach used. The aforementioned parameters were calculated for a number of magic and near-magic nuclei by using a partly self-consistent phenomenological nuclear mean field and the isovector part of the Landau-Migdal interaction in the particle-hole channel. The results of the calculations are compared with corresponding experimental data.

  14. Pumping test evaluation of stream depletion parameters.

    PubMed

    Lough, Hilary K; Hunt, Bruce

    2006-01-01

    Descriptions are given of a pumping test and a corresponding analysis that permit calculation of all five hydrogeological parameters appearing in the Hunt (2003) solution for stream depletion caused by ground water abstraction from a well beside a stream. This solution assumes that flow in the pumped aquifer is horizontal, flow in the overlying aquitard or system of aquitards is vertical, and the free surface in the top aquitard is allowed to draw down. The definition of an aquitard in this paper is any layer with a vertical hydraulic conductivity much lower than the horizontal hydraulic conductivity of the pumped aquifer. These "aquitards" may be reasonably permeable layers but are distinguished from the pumped aquifer by their hydraulic conductivity contrast. The pumping test requires a complete set of drawdown measurements from at least one observation well. This well must be deep enough to penetrate the pumped aquifer, and pumping must continue for a sufficient time to ensure that depleted streamflow becomes a significant portion of the well abstraction rate. Furthermore, two of the five parameters characterize an aquitard that overlies the pumped aquifer, and values for these parameters are seen to be dependent upon the initial water table elevation in the aquitard. The field test analyzed herein used a total of eight observation wells screened in the pumped aquifer, and measurements from these wells gave eight sets of parameters that are used in a sensitivity analysis to determine the relative importance of each parameter in the stream depletion calculations. PMID:16857031

  15. New Resolved Resonance Region Evaluation for 63Cu and 65Cu for Nuclear Criticality Safety Program

    SciTech Connect

    Sobes, Vladimir; Leal, Luiz C; Guber, Klaus H; Forget, Benoit; Kopecky, S.; Schillebeeckx, P.; Siegler, P.

    2014-01-01

    A new resolved resonance region evaluation of 63Cu and 65Cu was done in the energy region from 10-5 eV to 99.5 keV. The R-Matrix SAMMY method using the Reich-Moore approximation was used to create a new set of consistent resonance parameters. The new evaluation was based on three experimental transmission data sets; two measured at ORELA and one from MITR, and two radiative capture experimental data sets from GELINA. A total of 141 new resonances were identied for 63Cu and 117 for 65Cu. The corresponding set of external resonances for each isotope was based on the identied resonances above 99.5 keV from the ORELA transmission data. The negative external levels (bound levels) were determined to match the dierential thermal cross section measured at the MITR. Double dierential elastic scattering cross sections were calculated from the new set of resonance parameters. Benchmarking calculations were carried out on a set of ICSBEP benchmarks. This work is in support of the DOE Nuclear Criticality Safety Program.

  16. The precision of pharmacokinetic parameters in dynamic contrast-enhanced magnetic resonance imaging: the effect of sampling frequency and duration

    NASA Astrophysics Data System (ADS)

    Aerts, Hugo J. W. L.; Jaspers, K.; Backes, Walter H.

    2011-09-01

    Dynamic contrast-enhanced magnetic resonance imaging is increasingly applied for tumour diagnosis and early evaluation of therapeutic responses over time. However, the reliability of pharmacokinetic parameters derived from DCE-MRI is highly dependent on the experimental settings. In this study, the effect of sampling frequency (fs) and duration on the precision of pharmacokinetic parameters was evaluated based on system identification theory and computer simulations. Both theoretical analysis and simulations showed that a higher value of the pharmacokinetic parameter Ktrans required an increasing sampling frequency. For instance, for similar results, a relatively low fs of 0.2 Hz was sufficient for a low Ktrans of 0.1 min-1, compared to a high fs of 3 Hz for a high Ktrans of 0.5 min-1. For the parameter ve, a decreasing value required a higher sampling frequency. A sampling frequency below 0.1 Hz systematically resulted in imprecise estimates for all parameters. For the Ktrans and ve parameters, the sampling duration should be above 2 min, but durations of more than 7 min do not further improve parameter estimates.

  17. Use of Magnetic Resonance in the Evaluation of Cranial Trauma.

    PubMed

    Altmeyer, Wilson; Steven, Andrew; Gutierrez, Juan

    2016-05-01

    MR imaging is an extremely useful tool in the evaluation of traumatic brain injury in the emergency department. Although CT still plays the dominant role in urgent patient triage, MR imaging's impact on traumatic brain injury imaging continues to expand. MR imaging has shown superiority to CT for certain traumatic processes, such as diffuse axonal injury, cerebral contusion, and infarction. Magnetic resonance angiography and magnetic resonance venography allow emergent vascular imaging for patients that should avoid ionizing radiation or intravenous contrast. PMID:27150321

  18. Evaluation of Control Parameters for the Activated Sludge Process

    ERIC Educational Resources Information Center

    Stall, T. Ray; Sherrard, Josephy H.

    1978-01-01

    An evaluation of the use of the parameters currently being used to design and operate the activated sludge process is presented. The advantages and disadvantages for the use of each parameter are discussed. (MR)

  19. Methodological aspects in the calculation of parity-violating effects in nuclear magnetic resonance parameters.

    PubMed

    Weijo, Ville; Bast, Radovan; Manninen, Pekka; Saue, Trond; Vaara, Juha

    2007-02-21

    We examine the quantum chemical calculation of parity-violating (PV) electroweak contributions to the spectral parameters of nuclear magnetic resonance (NMR) from a methodological point of view. Nuclear magnetic shielding and indirect spin-spin coupling constants are considered and evaluated for three chiral molecules, H2O2, H2S2, and H2Se2. The effects of the choice of a one-particle basis set and the treatment of electron correlation, as well as the effects of special relativity, are studied. All of them are found to be relevant. The basis-set dependence is very pronounced, especially at the electron correlated ab initio levels of theory. Coupled-cluster and density-functional theory (DFT) results for PV contributions differ significantly from the Hartree-Fock data. DFT overestimates the PV effects, particularly with nonhybrid exchange-correlation functionals. Beginning from third-row elements, special relativity is of importance for the PV NMR properties, shown here by comparing perturbational one-component and various four-component calculations. In contrast to what is found for nuclear magnetic shielding, the choice of the model for nuclear charge distribution--point charge or extended (Gaussian)--has a significant impact on the PV contribution to the spin-spin coupling constants. PMID:17328593

  20. Simulation of parameter scaling in electron cyclotron resonance ion source plasmas using the GEM code

    SciTech Connect

    Cluggish, B.; Zhao, L.; Kim, J. S.

    2010-02-15

    Although heating power and gas pressure are two of the two of primary experimental ''knobs'' available to users of electron cyclotron resonance ion sources, there is still no clear understanding of how they interact in order to provide optimal plasma conditions. FAR-TECH, Inc. has performed a series of simulations with its generalized electron cyclotron resonance ion source model in which the power and pressure were varied over a wide range. Analysis of the numerical data produces scaling laws that predict the plasma parameters as a function of the power and pressure. These scaling laws are in general agreement with experimental data.

  1. Trojan resonant dynamics, stability, and chaotic diffusion, for parameters relevant to exoplanetary systems

    NASA Astrophysics Data System (ADS)

    Páez, Rocío Isabel; Efthymiopoulos, Christos

    2015-02-01

    The possibility that giant extrasolar planets could have small Trojan co-orbital companions has been examined in the literature from both viewpoints of the origin and dynamical stability of such a configuration. Here we aim to investigate the dynamics of hypothetical small Trojan exoplanets in domains of secondary resonances embedded within the tadpole domain of motion. To this end, we consider the limit of a massless Trojan companion of a giant planet. Without other planets, this is a case of the elliptic restricted three body problem (ERTBP). The presence of additional planets (hereafter referred to as the restricted multi-planet problem, RMPP) induces new direct and indirect secular effects on the dynamics of the Trojan body. The paper contains a theoretical and a numerical part. In the theoretical part, we develop a Hamiltonian formalism in action-angle variables, which allows us to treat in a unified way resonant dynamics and secular effects on the Trojan body in both the ERTBP or the RMPP. In both cases, our formalism leads to a decomposition of the Hamiltonian in two parts, . , called the basic model, describes resonant dynamics in the short-period (epicyclic) and synodic (libration) degrees of freedom, while contains only terms depending trigonometrically on slow (secular) angles. is formally identical in the ERTBP and the RMPP, apart from a re-definition of some angular variables. An important physical consequence of this analysis is that the slow chaotic diffusion along resonances proceeds in both the ERTBP and the RMPP by a qualitatively similar dynamical mechanism. We found that this is best approximated by the paradigm of `modulational diffusion'. In the paper's numerical part, we then focus on the ERTBP in order to make a detailed numerical demonstration of the chaotic diffusion process along resonances. Using color stability maps, we first provide a survey of the resonant web for characteristic mass parameter values of the primary, in which the

  2. Evaluation Parameters for Computer-Adaptive Testing

    ERIC Educational Resources Information Center

    Georgiadou, Elisabeth; Triantafillou, Evangelos; Economides, Anastasios A.

    2006-01-01

    With the proliferation of computers in test delivery today, adaptive testing has become quite popular, especially when examinees must be classified into two categories (passfail, master nonmaster). Several well-established organisations have provided standards and guidelines for the design and evaluation of educational and psychological testing.…

  3. Parameter-induced stochastic resonance based on spectral entropy and its application to weak signal detection.

    PubMed

    Zhang, Jinjing; Zhang, Tao

    2015-02-01

    The parameter-induced stochastic resonance based on spectral entropy (PSRSE) method is introduced for the detection of a very weak signal in the presence of strong noise. The effect of stochastic resonance on the detection is optimized using parameters obtained in spectral entropy analysis. Upon processing employing the PSRSE method, the amplitude of the weak signal is enhanced and the noise power is reduced, so that the frequency of the signal can be estimated with greater precision through spectral analysis. While the improvement in the signal-to-noise ratio is similar to that obtained using the Duffing oscillator algorithm, the computational cost reduces from O(N(2)) to O(N). The PSRSE approach is applied to the frequency measurement of a weak signal made by a vortex flow meter. The results are compared with those obtained applying the Duffing oscillator algorithm. PMID:25725879

  4. Parameter-induced stochastic resonance based on spectral entropy and its application to weak signal detection

    SciTech Connect

    Zhang, Jinjing; Zhang, Tao

    2015-02-15

    The parameter-induced stochastic resonance based on spectral entropy (PSRSE) method is introduced for the detection of a very weak signal in the presence of strong noise. The effect of stochastic resonance on the detection is optimized using parameters obtained in spectral entropy analysis. Upon processing employing the PSRSE method, the amplitude of the weak signal is enhanced and the noise power is reduced, so that the frequency of the signal can be estimated with greater precision through spectral analysis. While the improvement in the signal-to-noise ratio is similar to that obtained using the Duffing oscillator algorithm, the computational cost reduces from O(N{sup 2}) to O(N). The PSRSE approach is applied to the frequency measurement of a weak signal made by a vortex flow meter. The results are compared with those obtained applying the Duffing oscillator algorithm.

  5. Parameter-induced stochastic resonance based on spectral entropy and its application to weak signal detection.

    PubMed

    Zhang, Jinjing; Zhang, Tao

    2015-02-01

    The parameter-induced stochastic resonance based on spectral entropy (PSRSE) method is introduced for the detection of a very weak signal in the presence of strong noise. The effect of stochastic resonance on the detection is optimized using parameters obtained in spectral entropy analysis. Upon processing employing the PSRSE method, the amplitude of the weak signal is enhanced and the noise power is reduced, so that the frequency of the signal can be estimated with greater precision through spectral analysis. While the improvement in the signal-to-noise ratio is similar to that obtained using the Duffing oscillator algorithm, the computational cost reduces from O(N(2)) to O(N). The PSRSE approach is applied to the frequency measurement of a weak signal made by a vortex flow meter. The results are compared with those obtained applying the Duffing oscillator algorithm.

  6. Practice Parameter for Child and Adolescent Forensic Evaluations

    ERIC Educational Resources Information Center

    Journal of the American Academy of Child & Adolescent Psychiatry, 2011

    2011-01-01

    This Parameter addresses the key concepts that differentiate the forensic evaluation of children and adolescents from a clinical assessment. There are ethical issues unique to the forensic evaluation, because the forensic evaluator's duty is to the person, court, or agency requesting the evaluation, rather than to the patient. The forensic…

  7. Non-destructive evaluation of YIG Films by ferromagnetic resonance

    SciTech Connect

    Adams, J.D.; Talisa, S.H.; Kerestes, J.A. . Research and Development Center)

    1989-09-01

    A new technique for evaluating thick YIG films by measuring the ferromagnetic resonance (FMR) line-width on a localized area of the wafer is presented. The technique is based on the excitation of magnetostatic wave (MSW) resonances in a small area of the YIG film under a bias magnetic field well. The well is created by a small hole in a soft-iron plate in close proximity with the YIG film surface. The MSWs are excited by the electromagnetic fields emanating from a hole on the side of a waveguide. The technique is simple and straightforward and allows FMS measurements of different areas of a film.

  8. RIPL - Reference Input Parameter Library for Calculation of Nuclear Reactions and Nuclear Data Evaluations

    SciTech Connect

    Capote, R. , E-Mail: r.capotenoy@iaea.org; Herman, M.; Oblozinsky, P.; Young, P.G.; Goriely, S.; Belgya, T.; Ignatyuk, A.V.; Koning, A.J.; Hilaire, S.; Plujko, V.A.; Avrigeanu, M.; Bersillon, O.; Chadwick, M.B.; Fukahori, T.; Ge, Zhigang; Han, Yinlu; Kailas, S.; Kopecky, J.; Maslov, V.M.; Reffo, G.

    2009-12-15

    We describe the physics and data included in the Reference Input Parameter Library, which is devoted to input parameters needed in calculations of nuclear reactions and nuclear data evaluations. Advanced modelling codes require substantial numerical input, therefore the International Atomic Energy Agency (IAEA) has worked extensively since 1993 on a library of validated nuclear-model input parameters, referred to as the Reference Input Parameter Library (RIPL). A final RIPL coordinated research project (RIPL-3) was brought to a successful conclusion in December 2008, after 15 years of challenging work carried out through three consecutive IAEA projects. The RIPL-3 library was released in January 2009, and is available on the Web through (http://www-nds.iaea.org/RIPL-3/). This work and the resulting database are extremely important to theoreticians involved in the development and use of nuclear reaction modelling (ALICE, EMPIRE, GNASH, UNF, TALYS) both for theoretical research and nuclear data evaluations. The numerical data and computer codes included in RIPL-3 are arranged in seven segments: MASSES contains ground-state properties of nuclei for about 9000 nuclei, including three theoretical predictions of masses and the evaluated experimental masses of Audi et al. (2003). DISCRETE LEVELS contains 117 datasets (one for each element) with all known level schemes, electromagnetic and {gamma}-ray decay probabilities available from ENSDF in October 2007. NEUTRON RESONANCES contains average resonance parameters prepared on the basis of the evaluations performed by Ignatyuk and Mughabghab. OPTICAL MODEL contains 495 sets of phenomenological optical model parameters defined in a wide energy range. When there are insufficient experimental data, the evaluator has to resort to either global parameterizations or microscopic approaches. Radial density distributions to be used as input for microscopic calculations are stored in the MASSES segment. LEVEL DENSITIES contains

  9. RIPL-Reference Input Parameter Library for Calculation of Nuclear Reactions and Nuclear Data Evaluations

    SciTech Connect

    Capote, R.; Herman, M.; Capote,R.; Herman,M.; Oblozinsky,P.; Young,P.G.; Goriely,S.; Belgy,T.; Ignatyuk,A.V.; Koning,A.J.; Hilaire,S.; Pljko,V.A.; Avrigeanu,M.; Bersillon,O.; Chadwick,M.B.; Fukahori,T.; Ge, Zhigang; Han,Yinl,; Kailas,S.; Kopecky,J.; Maslov,V.M.; Reffo,G.; Sin,M.; Soukhovitskii,E.Sh.; Talou,P

    2009-12-01

    We describe the physics and data included in the Reference Input Parameter Library, which is devoted to input parameters needed in calculations of nuclear reactions and nuclear data evaluations. Advanced modelling codes require substantial numerical input, therefore the International Atomic Energy Agency (IAEA) has worked extensively since 1993 on a library of validated nuclear-model input parameters, referred to as the Reference Input Parameter Library (RIPL). A final RIPL coordinated research project (RIPL-3) was brought to a successful conclusion in December 2008, after 15 years of challenging work carried out through three consecutive IAEA projects. The RIPL-3 library was released in January 2009, and is available on the Web through http://www-nds.iaea.org/RIPL-3/. This work and the resulting database are extremely important to theoreticians involved in the development and use of nuclear reaction modelling (ALICE, EMPIRE, GNASH, UNF, TALYS) both for theoretical research and nuclear data evaluations. The numerical data and computer codes included in RIPL-3 are arranged in seven segments: MASSES contains ground-state properties of nuclei for about 9000 nuclei, including three theoretical predictions of masses and the evaluated experimental masses of Audi et al. (2003). DISCRETE LEVELS contains 117 datasets (one for each element) with all known level schemes, electromagnetic and {gamma}-ray decay probabilities available from ENSDF in October 2007. NEUTRON RESONANCES contains average resonance parameters prepared on the basis of the evaluations performed by Ignatyuk and Mughabghab. OPTICAL MODEL contains 495 sets of phenomenological optical model parameters defined in a wide energy range. When there are insufficient experimental data, the evaluator has to resort to either global parameterizations or microscopic approaches. Radial density distributions to be used as input for microscopic calculations are stored in the MASSES segment. LEVEL DENSITIES contains

  10. RIPL - Reference Input Parameter Library for Calculation of Nuclear Reactions and Nuclear Data Evaluations

    NASA Astrophysics Data System (ADS)

    Capote, R.; Herman, M.; Obložinský, P.; Young, P. G.; Goriely, S.; Belgya, T.; Ignatyuk, A. V.; Koning, A. J.; Hilaire, S.; Plujko, V. A.; Avrigeanu, M.; Bersillon, O.; Chadwick, M. B.; Fukahori, T.; Ge, Zhigang; Han, Yinlu; Kailas, S.; Kopecky, J.; Maslov, V. M.; Reffo, G.; Sin, M.; Soukhovitskii, E. Sh.; Talou, P.

    2009-12-01

    We describe the physics and data included in the Reference Input Parameter Library, which is devoted to input parameters needed in calculations of nuclear reactions and nuclear data evaluations. Advanced modelling codes require substantial numerical input, therefore the International Atomic Energy Agency (IAEA) has worked extensively since 1993 on a library of validated nuclear-model input parameters, referred to as the Reference Input Parameter Library (RIPL). A final RIPL coordinated research project (RIPL-3) was brought to a successful conclusion in December 2008, after 15 years of challenging work carried out through three consecutive IAEA projects. The RIPL-3 library was released in January 2009, and is available on the Web through http://www-nds.iaea.org/RIPL-3/. This work and the resulting database are extremely important to theoreticians involved in the development and use of nuclear reaction modelling (ALICE, EMPIRE, GNASH, UNF, TALYS) both for theoretical research and nuclear data evaluations. The numerical data and computer codes included in RIPL-3 are arranged in seven segments: MASSES contains ground-state properties of nuclei for about 9000 nuclei, including three theoretical predictions of masses and the evaluated experimental masses of Audi et al. (2003). DISCRETE LEVELS contains 117 datasets (one for each element) with all known level schemes, electromagnetic and γ-ray decay probabilities available from ENSDF in October 2007. NEUTRON RESONANCES contains average resonance parameters prepared on the basis of the evaluations performed by Ignatyuk and Mughabghab. OPTICAL MODEL contains 495 sets of phenomenological optical model parameters defined in a wide energy range. When there are insufficient experimental data, the evaluator has to resort to either global parameterizations or microscopic approaches. Radial density distributions to be used as input for microscopic calculations are stored in the MASSES segment. LEVEL DENSITIES contains

  11. Classification of hydrological parameter sensitivity and evaluation of parameter transferability across 431 US MOPEX basins

    NASA Astrophysics Data System (ADS)

    Ren, Huiying; Hou, Zhangshuan; Huang, Maoyi; Bao, Jie; Sun, Yu; Tesfa, Teklu; Ruby Leung, L.

    2016-05-01

    The Community Land Model (CLM) represents physical, chemical, and biological processes of the terrestrial ecosystems that interact with climate across a range of spatial and temporal scales. As CLM includes numerous sub-models and associated parameters, the high-dimensional parameter space presents a formidable challenge for quantifying uncertainty and improving Earth system predictions needed to assess environmental changes and risks. This study aims to evaluate the potential of transferring hydrologic model parameters in CLM through sensitivity analyses and classification across watersheds from the Model Parameter Estimation Experiment (MOPEX) in the United States. The sensitivity of CLM-simulated water and energy fluxes to hydrological parameters across 431 MOPEX basins are first examined using an efficient stochastic sampling-based sensitivity analysis approach. Linear, interaction, and high-order nonlinear impacts are all identified via statistical tests and stepwise backward removal parameter screening. The basins are then classified according to their parameter sensitivity patterns (internal attributes), as well as their hydrologic indices/attributes (external hydrologic factors) separately, using Principal component analysis (PCA) and expectation-maximization (EM) - based clustering approach. Similarities and differences among the parameter sensitivity-based classification system (S-Class), the hydrologic indices-based classification (H-Class), and the Koppen climate classification systems (K-Class) are discussed. Within each parameter sensitivity-based classification system (S-Class) with similar parameter sensitivity characteristics, similar inversion modeling setups can be used for parameter calibration, and the parameters and their contribution or significance to water and energy cycling may also be more transferrable. This classification study provides guidance on identifiable parameters, and on parameterization and inverse model design for CLM but the

  12. Note: Modified π-type Butterworth-Van Dyke model for dual-mode Lamb-wave resonator with precise two-port Y-parameter characterizations

    NASA Astrophysics Data System (ADS)

    Wang, Yong; Hong, Yan; Goh, Wang Ling; Mu, Xiaojing

    2016-10-01

    Dual-mode Lamb-wave resonator has become a powerful component for clock reference and sensing applications, enabling efficient compensations of temperature effects, concurrent measurements of multiple environmental parameters, etc. An equivalent circuit model for the dual-mode Lamb-wave resonator is indispensable as it provides a means as well as being an effective tool for evaluating device characteristics and to aid the designing of circuitry for the resonators. This could be the first time ever that an efficient equivalent-circuit model, i.e., modified π-type Butterworth-Van Dyke model for dual-mode Lamb-wave resonators is reported. Evaluated by experiments, this model attains noteworthy agreements on both the magnitudes and phases of Y11 and Y21 of the measurement results. Compared to literature, the proposed model is capable of modeling the dual resonances efficiently. Moreover, this work also proves more accurate when viewing the Y-parameters across a wide frequency range. The gained features of this model are most beneficial for the analysis of the dual-mode Lamb-wave resonator and also for the designing of circuits.

  13. A novel parameter-induced stochastic resonance phenomena in fractional Fourier domain

    NASA Astrophysics Data System (ADS)

    Lin, Lifeng; Wang, Huiqi; Lv, Wangyong; Zhong, Suchuan

    2016-08-01

    The parameter-induced stochastic resonance (SR) phenomenon in a novel self-adaptive dynamical system driven by linear frequency modulated (LFM) signal and additive noise is considered from the view of the signal-to-noise ratio (SNR). It is found that the dynamical system can be perfectly analyzed by equivalently transforming it into a traditional first-order linear dynamical system driven by periodic signal and additive noise in fractional Fourier transform (FrFT) domain with an optimal rotated angle, and the theoretical analysis and simulation results show that output SNR exhibits the SR behavior when it is plotted as a function of the system parameter. Furthermore, the optimal value of adjusted parameter is obtained, and the possible area of SNR gain is theoretically determined only by center-frequency and modulated frequency of the driving LFM signal.

  14. JUPITER PROJECT - JOINT UNIVERSAL PARAMETER IDENTIFICATION AND EVALUATION OF RELIABILITY

    EPA Science Inventory

    The JUPITER (Joint Universal Parameter IdenTification and Evaluation of Reliability) project builds on the technology of two widely used codes for sensitivity analysis, data assessment, calibration, and uncertainty analysis of environmental models: PEST and UCODE.

  15. Parameter allocation of parallel array bistable stochastic resonance and its application in communication systems

    NASA Astrophysics Data System (ADS)

    Liu, Jian; Wang, You-Guo; Zhai, Qi-Qing; Liu, Jin

    2016-10-01

    In this paper, we propose a parameter allocation scheme in a parallel array bistable stochastic resonance-based communication system (P-BSR-CS) to improve the performance of weak binary pulse amplitude modulated (BPAM) signal transmissions. The optimal parameter allocation policy of the P-BSR-CS is provided to minimize the bit error rate (BER) and maximize the channel capacity (CC) under the adiabatic approximation condition. On this basis, we further derive the best parameter selection theorem in realistic communication scenarios via variable transformation. Specifically, the P-BSR structure design not only brings the robustness of parameter selection optimization, where the optimal parameter pair is not fixed but variable in quite a wide range, but also produces outstanding system performance. Theoretical analysis and simulation results indicate that in the P-BSR-CS the proposed parameter allocation scheme yields considerable performance improvement, particularly in very low signal-to-noise ratio (SNR) environments. Project supported by the National Natural Science Foundation of China (Grant No. 61179027), the Qinglan Project of Jiangsu Province of China (Grant No. QL06212006), and the University Postgraduate Research and Innovation Project of Jiangsu Province (Grant Nos. KYLX15_0829, KYLX15_0831).

  16. Practical magnetic resonance imaging evaluation of peripheral nerves in children: magnetic resonance neurography.

    PubMed

    Cortes, Cesar; Ramos, Yanerys; Restrepo, Ricardo; Restrepo, Jose Andres; Grossman, John A I; Lee, Edward Y

    2013-07-01

    Magnetic resonance (MR) imaging is an excellent tool for the evaluation of peripheral nerves in children not only because of its excellent soft tissue contrast resolution but also because it is noninvasive and does not use ionizing radiation. In nonconclusive cases, MR neurography can be complementary to physical examination and electromyography in identifying a specific affected nerve and the site of the lesion. This article reviews the MR imaging technique used in the evaluation of peripheral nerves (ie, MR neurography), its major indications, and the common pathologic conditions encountered in the pediatric population.

  17. Relationships between nuclear magnetic resonance parameters used to characterize weathering spilled oil and soil toxicity in central Patagonia.

    PubMed

    Ríos, Stella Maris; Barquin, Mercedes; Katusich, Ofelia; Nudelman, Norma

    2014-01-01

    Oil spill in the Central Patagonian zone was studied to evaluate if any relationship exists between the parameters used to characterize weathering spilled oil and soil toxicity for two plant species and to evaluate if the phytotoxicity to local species would be a good index for the soil contamination. Nuclear magnetic resonance (NMR) structural indexes and column chromatography compositional indexes were determined to characterize the oil spill in the soil samples. Bioassays were also carried out using Lactuca sativa L (reference) and Atriplex lampa (native species) as test organisms. Measurements of the total petroleum hydrocarbon (TPH) and the electrical conductivity (EC) of the soil were carried out to evaluate the effect on the bioassays. The principal components analysis of the parameters determined by NMR, compositional indexes, EC, TPH, and toxicology data shows that the first three principal components accounted for the 78% of the total variance (40%, 25%, and 13% for the first, second, and third PC, respectively). A good agreement was found between information obtained by compositional indexes and NMR structural indexes. Soil toxicity increases with the increase of EC and TPH. Other factors, such as, the presence of branched and aromatic hydrocarbons is also significant. The statistical evaluation showed that the Euclidean distances (3D) between the background and each one of the samples might be a better indicator of the soil contamination, compared with chemical criterion of TPH. PMID:25145179

  18. Relationships between nuclear magnetic resonance parameters used to characterize weathering spilled oil and soil toxicity in central Patagonia.

    PubMed

    Ríos, Stella Maris; Barquin, Mercedes; Katusich, Ofelia; Nudelman, Norma

    2014-01-01

    Oil spill in the Central Patagonian zone was studied to evaluate if any relationship exists between the parameters used to characterize weathering spilled oil and soil toxicity for two plant species and to evaluate if the phytotoxicity to local species would be a good index for the soil contamination. Nuclear magnetic resonance (NMR) structural indexes and column chromatography compositional indexes were determined to characterize the oil spill in the soil samples. Bioassays were also carried out using Lactuca sativa L (reference) and Atriplex lampa (native species) as test organisms. Measurements of the total petroleum hydrocarbon (TPH) and the electrical conductivity (EC) of the soil were carried out to evaluate the effect on the bioassays. The principal components analysis of the parameters determined by NMR, compositional indexes, EC, TPH, and toxicology data shows that the first three principal components accounted for the 78% of the total variance (40%, 25%, and 13% for the first, second, and third PC, respectively). A good agreement was found between information obtained by compositional indexes and NMR structural indexes. Soil toxicity increases with the increase of EC and TPH. Other factors, such as, the presence of branched and aromatic hydrocarbons is also significant. The statistical evaluation showed that the Euclidean distances (3D) between the background and each one of the samples might be a better indicator of the soil contamination, compared with chemical criterion of TPH.

  19. Symmetric Resonance Charge Exchange Cross Section Based on Impact Parameter Treatment

    NASA Technical Reports Server (NTRS)

    Omidvar, Kazem; Murphy, Kendrah; Atlas, Robert (Technical Monitor)

    2002-01-01

    Using a two-state impact parameter approximation, a calculation has been carried out to obtain symmetric resonance charge transfer cross sections between nine ions and their parent atoms or molecules. Calculation is based on a two-dimensional numerical integration. The method is mostly suited for hydrogenic and some closed shell atoms. Good agreement has been obtained with the results of laboratory measurements for the ion-atom pairs H+-H, He+-He, and Ar+-Ar. Several approximations in a similar published calculation have been eliminated.

  20. Longitudinal NMR parameter measurements of Japanese pear fruit during the growing process using a mobile magnetic resonance imaging system

    NASA Astrophysics Data System (ADS)

    Geya, Yuto; Kimura, Takeshi; Fujisaki, Hirotaka; Terada, Yasuhiko; Kose, Katsumi; Haishi, Tomoyuki; Gemma, Hiroshi; Sekozawa, Yoshihiko

    2013-01-01

    Longitudinal nuclear magnetic resonance (NMR) parameter measurements of Japanese pear fruit (Pyrus pyrifolia Nakai, Kosui) were performed using an electrically mobile magnetic resonance imaging (MRI) system with a 0.2 T and 16 cm gap permanent magnet. To measure the relaxation times and apparent diffusion coefficients of the pear fruit in relation to their weight, seven pear fruits were harvested almost every week during the cell enlargement period and measured in a research orchard. To evaluate the in situ relaxation times, six pear fruits were longitudinally measured for about two months during the same period. The measurements for the harvested samples showed good agreement with the in situ measurements. From the measurements of the harvested samples, it is clear that the relaxation rates of the pear fruits linearly change with the inverse of the linear dimension of the fruits, demonstrating that the relaxation mechanism is a surface relaxation. We therefore conclude that the mobile MRI system is a useful device for measuring the NMR parameters of outdoor living plants.

  1. A magnetic resonance imaging study on the articulatory and acoustic speech parameters of Malay vowels

    PubMed Central

    2014-01-01

    The phonetic properties of six Malay vowels are investigated using magnetic resonance imaging (MRI) to visualize the vocal tract in order to obtain dynamic articulatory parameters during speech production. To resolve image blurring due to the tongue movement during the scanning process, a method based on active contour extraction is used to track tongue contours. The proposed method efficiently tracks tongue contours despite the partial blurring of MRI images. Consequently, the articulatory parameters that are effectively measured as tongue movement is observed, and the specific shape of the tongue and its position for all six uttered Malay vowels are determined. Speech rehabilitation procedure demands some kind of visual perceivable prototype of speech articulation. To investigate the validity of the measured articulatory parameters based on acoustic theory of speech production, an acoustic analysis based on the uttered vowels by subjects has been performed. As the acoustic speech and articulatory parameters of uttered speech were examined, a correlation between formant frequencies and articulatory parameters was observed. The experiments reported a positive correlation between the constriction location of the tongue body and the first formant frequency, as well as a negative correlation between the constriction location of the tongue tip and the second formant frequency. The results demonstrate that the proposed method is an effective tool for the dynamic study of speech production. PMID:25060583

  2. A simple method for extracting material parameters of multilayered MEMS structures using resonance frequency measurements

    NASA Astrophysics Data System (ADS)

    Sun, Chao; Zhou, Zai-Fa; Li, Wei-Hua; Huang, Qing-An

    2014-07-01

    Multilayered structures are increasingly used in MEMS. Based on the resonant frequency of the doubly-clamped multilayered beam, the Young’s modulus and residual stress for an individual layer have been measured by designing beam test structures for each layer with different widths. Taking into account the buckling or no buckling problem of the multilayered beam, this paper introduces a model for the resonant frequency of the beam. An approach to extract the Young’s modulus and residual stress for the individual layer is developed. The validity of this approach has been studied using finite element modeling. As a multilayered example, test structures for a gold/polysilicon bilayer beam were fabricated. A scanning laser Doppler vibrometer system was used to measure the resonant frequency of the beam. The extracted parameters are that the average value of Young’s modulus of polysilicon and gold are 133.7 GPa and 78.6 GPa with standard deviation being 4.2 GPa and 11.5 GPa, respectively; the average value of residual stress of polysilicon and gold are 13.9 MPa (compressive) and 19.7 MPa (tensile) with standard deviation being 0.47 MPa and 4.4 MPa, respectively.

  3. Hydrogeological Parameter Estimation Using Low-Field Proton Nuclear Magnetic Resonance: Lessons from the Laboratory

    NASA Astrophysics Data System (ADS)

    Keating, K.; Falzone, S.; Osterman, G. K.; Wallace, D. S.

    2014-12-01

    Geophysical methods can provide a non-invasive method for estimating spatial variability in hydrogeological parameters such as water content, hydraulic conductivity, and matric potential. Proton nuclear magnetic resonance (NMR) is unique amongst geophysical methods in that it is directly sensitive to water, via the initial signal magnitude, and thus provides a robust estimate of water content. In addition, the NMR relaxation time is sensitive to pore geometry, allowing it to be used to predict the hydraulic conductivity and to determine water retention curves. While NMR measurements are considered a mature technology in the petroleum industry, the strength of NMR data for hydrogeophysical studies is still being realized. The major ongoing challenge is to generate a functional mapping of the relationship between pore geometry and relaxation time, while accounting for pore chemistry. In our research, we are developing and refining quantitative petrophysical models that relate NMR parameters to hydrogeological parameters. Here we present laboratory measurements that highlight our recent successes in using NMR measurements to estimate several hydrogeological parameters and overcome the limitations of the standard petrophysical models. We examine these relationships by collecting NMR measurements on synthetic and geologic materials with carefully controlled or quantified pore properties, i.e., pore surface-area-to-volume ratio (S/V), pore size and surface iron concentration, and relate these variables to hydrogeological parameters including water content, hydraulic conductivity, and/or the water retention curve. Our major results include developing a relationship between the NMR relaxation times and water saturation across diverse chemical environments, and showing that for materials with rough surfaces, S/V, and not average pore diameter, is the relevant parameter in the interpretation of NMR data. Despite the many challenges in interpreting the measurements, valuable

  4. Enhancement of the efficiency and control of emission parameters of an unstable-resonator chemical oxygen-iodine laser

    SciTech Connect

    Boreisho, A S; Lobachev, V V; Savin, A V; Strakhov, S Yu; Trilis, A V

    2007-07-31

    The outlook is considered for the development of a high-power supersonic flowing chemical oxygen-iodine laser operating as an amplifier and controlled by radiation from a master oscillator by using an unstable resonator with a hole-coupled mirror. The influence of the seed radiation intensity, the coupling-hole diameter, the active-medium length, and the magnification factor on the parameters of laser radiation is analysed. It is shown that the use of such resonators is most advisable in medium-power oxygen-iodine lasers for which classical unstable resonators are inefficient because of their low magnification factors. The use of unstable resonators with a hole-coupled mirror and injection provides the control of radiation parameters and a considerable increase in the output power and brightness of laser radiation. (control of laser radiation parameters)

  5. Estimation of water retention parameters from nuclear magnetic resonance relaxation time distributions

    PubMed Central

    Costabel, Stephan; Yaramanci, Ugur

    2013-01-01

    [1] For characterizing water flow in the vadose zone, the water retention curve (WRC) of the soil must be known. Because conventional WRC measurements demand much time and effort in the laboratory, alternative methods with shortened measurement duration are desired. The WRC can be estimated, for instance, from the cumulative pore size distribution (PSD) of the investigated material. Geophysical applications of nuclear magnetic resonance (NMR) relaxometry have successfully been applied to recover PSDs of sandstones and limestones. It is therefore expected that the multiexponential analysis of the NMR signal from water-saturated loose sediments leads to a reliable estimation of the WRC. We propose an approach to estimate the WRC using the cumulative NMR relaxation time distribution and approximate it with the well-known van-Genuchten (VG) model. Thereby, the VG parameter n, which controls the curvature of the WRC, is of particular interest, because it is the essential parameter to predict the relative hydraulic conductivity. The NMR curves are calibrated with only two conventional WRC measurements, first, to determine the residual water content and, second, to define a fixed point that relates the relaxation time to a corresponding capillary pressure. We test our approach with natural and artificial soil samples and compare the NMR-based results to WRC measurements using a pressure plate apparatus and to WRC predictions from the software ROSETTA. We found that for sandy soils n can reliably be estimated with NMR, whereas for samples with clay and silt contents higher than 10% the estimation fails. This is the case when the hydraulic properties of the soil are mainly controlled by the pore constrictions. For such samples, the sensitivity of the NMR method for the pore bodies hampers a plausible WRC estimation. Citation: Costabel, S., and U. Yaramanci (2013), Estimation of water retention parameters from nuclear magnetic resonance relaxation time distributions, Water

  6. Thoracic magnetic resonance imaging for the evaluation of pulmonary emphysema.

    PubMed

    Lee, Sang Min; Seo, Joon Beom; Hwang, Hye Jeon; Kim, Eun Young; Oh, Sang Young; Kim, Ji-Eun

    2013-05-01

    Pulmonary emphysema is a pathologic condition characterized by permanently enlarged airspaces distal to the terminal bronchiole with destruction of the alveolar walls. Functional information of the lungs is important to understand the pathophysiology of emphysema and that of chronic obstructive pulmonary disease. With the recent developments in magnetic resonance imaging (MRI) techniques, functional MRI with variable MR sequences can be used for the evaluation of different physiological and anatomic changes seen in cases of pulmonary emphysema. In this review article, we will focus on a brief description of each method, results of some of the most recent work, and the clinical application of such knowledge.

  7. Resonance parameters of the first 1/2+ state in Be9 and astrophysical implications

    NASA Astrophysics Data System (ADS)

    Burda, O.; von Neumann-Cosel, P.; Richter, A.; Forssén, C.; Brown, B. A.

    2010-07-01

    Spectra of the Be9(e,e') reaction have been measured at the Superconducting Darmstadt Electron Linear Accelerator at an electron energy of E0=73 MeV and scattering angles of 93° and 141° with high-energy resolution up to excitation energies of Ex=8 MeV. The astrophysically relevant resonance parameters of the first excited 1/2+ state of Be9 have been extracted in a one-level approximation of R-matrix theory, resulting in resonance energy ER=1.748(6) MeV and width ΓR=274(8) keV, which are in good agreement with the latest Be9(γ,n) experiment but with considerably improved uncertainties. However, the reduced B(E1) transition strength deduced from an extrapolation of the (e,e') data to the photon point is smaller by a factor of two. Implications of the new results for possible production of C12 in neutron-rich astrophysical scenarios are discussed.

  8. Autoionization Resonances in Orientation and Alignment Parameters for Excited Ions after Electron Impact Ionization.

    NASA Astrophysics Data System (ADS)

    Balashov, Vselovod; Bartschat, Klaus; Marchalant, Pascale

    1997-04-01

    We have extended previous work for alignment and orientation parameters in simultaneous ionization-excitation [1] to include the effect of autoionizing resonances. The expected effect is similar to that suggested for photoionization via autoionizing states [2]. Special emphasis is given to the process e + He --> e_scattered+e_ejected +He^+(2p), followed by He^+(2p) --> He^+(1s) + γ where the scattered electron and the emitted photon are detected in coincidence. 1. R. Schwienhorst, A. Raeker, K. Bartschat and K. Blum (1996), 1. J. Phys. B 29, 2305 2. V.V. Balashov, N.M. Kabachnik and V.S. Senashenko (1983), 2. Book of Abstracts ICPEAC XIII, 23 permanent address: Moscow State University

  9. Determination of molecular spectroscopic parameters and energy-transfer rates by double-resonance spectroscopy

    NASA Technical Reports Server (NTRS)

    Steinfeld, J. I.; Foy, B.; Hetzler, J.; Flannery, C.; Klaassen, J.; Mizugai, Y.; Coy, S.

    1990-01-01

    The spectroscopy of small to medium-size polyatomic molecules can be extremely complex, especially in higher-lying overtone and combination vibrational levels. The high density of levels also complicates the understanding of inelastic collision processes, which is required to model energy transfer and collision broadening of spectral lines. Both of these problems can be addressed by double-resonance spectroscopy, i.e., time-resolved pump-probe measurements using microwave, infrared, near-infrared, and visible-wavelength sources. Information on excited-state spectroscopy, transition moments, inelastic energy transfer rates and propensity rules, and pressure-broadening parameters may be obtained from such experiments. Examples are given for several species of importance in planetary atmospheres, including ozone, silane, ethane, and ammonia.

  10. Evaluation of trapping parameters of annealed natural quartz

    NASA Astrophysics Data System (ADS)

    Zhou, Rui; Wei, Ming-Jian; Song, Bo; Zhang, Yan; Zhao, Qiu-Yue; Pan, Bao-Lin; Li, Teng-Fei

    2016-05-01

    The thermoluminescence (TL) trapping parameters of annealed quartz have been investigated. The apparent TL peaks observed at temperatures of 133 °C, 211 °C, 266 °C and 405 °C, respectively, were named Peak I, Peak II, Peak III and Peak IV. The Tm - Tstop method is applied to investigate the number of peaks and their positions, and to obtain the trap distributions in the quartz. Peak shape (PS), Hoogenstraaten method (Various Heating Rates Method, VHR), and Computerized Glow Curve Deconvolution (CGCD) are used to evaluate the trapping parameters of the annealed quartz. The glow curve can be considered as a superposition of at least nine overlapping peaks. These peaks show up at 133 °C, 211 °C, 266 °C, 308 °C, 333 °C, 384 °C, 441 °C, 466 °C and 484 °C. The PS method can be only used in evaluating the parameters for Peaks I. The VHR method can be used in evaluating the trapping parameters for the first three peaks. CGCD method is complementary to obtaining parameters for the sub-peaks, and the thermal quenching correction with the Urbach's method is necessary. The Urbach's coefficient for the quartz is 30.03 kTm.

  11. A Novel Parameter for Ramp Metering and Evaluation

    NASA Astrophysics Data System (ADS)

    Li, Jian; Jia, Yuanhua; Zhang, Yong; Chen, Feng; Ao, Guchang

    Real and scientific traffic flow parameter are the basis to make efficient traffic control strategy and establish control function and this will leads to an appropriate and impartial reflection to efficiency and equity of control property. Intelligent control is a new development where the control problem is to find the combination of control measures that result in the best road performance and control effectiveness. The problems of intelligent metering evaluation for local ramp are considered. In this paper, a novel ramp queuing parameter-the reduplicated waiting time was posed using the queuing theory. With in-situ traffic flow data, comparison between the novel and previous parameters are made to clarify the advantages of the novel parameter.

  12. Elbow magnetic resonance imaging: imaging anatomy and evaluation.

    PubMed

    Hauptfleisch, Jennifer; English, Collette; Murphy, Darra

    2015-04-01

    The elbow is a complex joint. Magnetic resonance imaging (MRI) is often the imaging modality of choice in the workup of elbow pain, especially in sports injuries and younger patients who often have either a history of a chronic repetitive strain such as the throwing athlete or a distinct traumatic injury. Traumatic injuries and alternative musculoskeletal pathologies can affect the ligaments, musculotendinous, cartilaginous, and osseous structures of the elbow as well as the 3 main nerves to the upper limb, and these structures are best assessed with MRI.Knowledge of the complex anatomy of the elbow joint as well as patterns of injury and disease is important for the radiologist to make an accurate diagnosis in the setting of elbow pain. This chapter will outline elbow anatomy, basic imaging parameters, compartmental pathology, and finally applications of some novel MRI techniques. PMID:25835585

  13. Nuclear magnetic resonance evaluation of stroke: a preliminary report

    SciTech Connect

    Bryan, R.N.; Willcott, M.R.; Schneiders, N.J.; Ford, J.J.; Derman, H.S.

    1983-10-01

    Nine patients who had acute and subacute stroke were examined by nuclear magnetic resonance (NMR) using a 6-MHz Bruker Instruments proton scanner. A modified Carr-Purcell-Meiboom-Gill pulse sequence was used for signal detection. The resultant string of spin-echoes was Fourier transformed into projections that were subsequently back-projected to a series of spin-echo images. From these images, spin density and T/sub 2/ were calculated for each pixel. The NMR scans revealed stroke in each of the patients, while CT demonstrated only eight of the lesions. T/sub 2/ was prolonged in all of the ischemic regions and is the most sensitive NMR parameter in detecting stroke. These preliminary results suggest that NMR scanning of patients who have acute stroke may be cliniclly useful, and that the T/sub 2/ component of the NRM signal is most important.

  14. Elbow magnetic resonance imaging: imaging anatomy and evaluation.

    PubMed

    Hauptfleisch, Jennifer; English, Collette; Murphy, Darra

    2015-04-01

    The elbow is a complex joint. Magnetic resonance imaging (MRI) is often the imaging modality of choice in the workup of elbow pain, especially in sports injuries and younger patients who often have either a history of a chronic repetitive strain such as the throwing athlete or a distinct traumatic injury. Traumatic injuries and alternative musculoskeletal pathologies can affect the ligaments, musculotendinous, cartilaginous, and osseous structures of the elbow as well as the 3 main nerves to the upper limb, and these structures are best assessed with MRI.Knowledge of the complex anatomy of the elbow joint as well as patterns of injury and disease is important for the radiologist to make an accurate diagnosis in the setting of elbow pain. This chapter will outline elbow anatomy, basic imaging parameters, compartmental pathology, and finally applications of some novel MRI techniques.

  15. Evaluation of hail suppression programme effectiveness using radar derived parameters

    NASA Astrophysics Data System (ADS)

    Tani, Satyanarayana; Paulitsch, Helmut; Teschl, Reinhard; Süsser-Rechberger, Barbara

    2016-04-01

    The objective of this study is evaluating "the operational hail suppression programme" in the province of Styria, Austria "for the year 2015". For the evaluation purpose the HAILSYS software tool was developed by integrating single polarization C-band weather radar data, aircraft trajectory, radiosonde freezing level data, hail events and crop damages information from the ground. The hail related radar derived parameters are: hail mass aloft, hail mass flux, probability of hail, vertical integrated hail mass, hail kinetic energy flux, and storm severity index. The spatial maps of hail kinetic energy and hail mass were developed to evaluate the seeding effect. The time history plots of vertical integrated hail mass, hail mass aloft and the probability of hail are drawn over an entire cell lifetime. The sensitivity and variation of radar hail parameters over time and associated changes due to cloud seeding will be presented.

  16. Parameter Sensitivity Evaluation of the CLM-Crop model

    NASA Astrophysics Data System (ADS)

    Drewniak, B. A.; Zeng, X.; Mametjanov, A.; Anitescu, M.; Norris, B.; Kotamarthi, V. R.

    2011-12-01

    In order to improve carbon cycling within Earth System Models, crop representation for corn, spring wheat, and soybean species has been incorporated into the latest version of the Community Land Model (CLM), the land surface model in the Community Earth System Model. As a means to evaluate and improve the CLM-Crop model, we will determine the sensitivity of various crop parameters on carbon fluxes (such as GPP and NEE), yields, and soil organic matter. The sensitivity analysis will perform small perturbations over a range of values for each parameter on individual grid sites, for comparison with AmeriFlux data, as well as globally so crop model parameters can be improved. Over 20 parameters have been identified for evaluation in this study including carbon-nitrogen ratios for leaves, stems, roots, and organs; fertilizer applications; growing degree days for each growth stage; and more. Results from this study will be presented to give a better understanding of the sensitivity of the various parameters used to represent crops, which will help improve the overall model performance and aid with determining future influences climate change will have on cropland ecosystems.

  17. Extracting the resonance parameters from experimental data on scattering of charged particles

    NASA Astrophysics Data System (ADS)

    Vaandrager, P.; Rakityansky, S. A.

    2016-02-01

    A new parametrization of the multi-channel S-matrix is used to fit scattering data and then to locate the resonances as its poles. The S-matrix is written in terms of the corresponding “in” and “out” Jost matrices which are expanded in the Taylor series of the collision energy E around an appropriately chosen energy E0. In order to do this, the Jost matrices are written in a semi-analytic form where all the factors (involving the channel momenta and Sommerfeld parameters) responsible for their “bad behavior” (i.e., responsible for the multi-valuedness of the Jost matrices and for branching of the Riemann surface of the energy) are given explicitly. The remaining unknown factors in the Jost matrices are analytic and single-valued functions of the variable E and are defined on a simple energy plane. The expansion is done for these analytic functions and the expansion coefficients are used as the fitting parameters. The method is tested on a two-channel model, using a set of artificially generated data points with typical error bars and a typical random noise in the positions of the points.

  18. Achieving high bit rate logical stochastic resonance in a bistable system by adjusting parameters

    NASA Astrophysics Data System (ADS)

    Yang, Ding-Xin; Gu, Feng-Shou; Feng, Guo-Jin; Yang, Yong-Min; Ball, Andrew

    2015-11-01

    The phenomenon of logical stochastic resonance (LSR) in a nonlinear bistable system is demonstrated by numerical simulations and experiments. However, the bit rates of the logical signals are relatively low and not suitable for practical applications. First, we examine the responses of the bistable system with fixed parameters to different bit rate logic input signals, showing that an arbitrary high bit rate LSR in a bistable system cannot be achieved. Then, a normalized transform of the LSR bistable system is introduced through a kind of variable substitution. Based on the transform, it is found that LSR for arbitrary high bit rate logic signals in a bistable system can be achieved by adjusting the parameters of the system, setting bias value and amplifying the amplitudes of logic input signals and noise properly. Finally, the desired OR and AND logic outputs to high bit rate logic inputs in a bistable system are obtained by numerical simulations. The study might provide higher feasibility of LSR in practical engineering applications. Project supported by the National Natural Science Foundation of China (Grant No. 51379526).

  19. Blind Source Parameters for Performance Evaluation of Despeckling Filters.

    PubMed

    Biradar, Nagashettappa; Dewal, M L; Rohit, ManojKumar; Gowre, Sanjaykumar; Gundge, Yogesh

    2016-01-01

    The speckle noise is inherent to transthoracic echocardiographic images. A standard noise-free reference echocardiographic image does not exist. The evaluation of filters based on the traditional parameters such as peak signal-to-noise ratio, mean square error, and structural similarity index may not reflect the true filter performance on echocardiographic images. Therefore, the performance of despeckling can be evaluated using blind assessment metrics like the speckle suppression index, speckle suppression and mean preservation index (SMPI), and beta metric. The need for noise-free reference image is overcome using these three parameters. This paper presents a comprehensive analysis and evaluation of eleven types of despeckling filters for echocardiographic images in terms of blind and traditional performance parameters along with clinical validation. The noise is effectively suppressed using the logarithmic neighborhood shrinkage (NeighShrink) embedded with Stein's unbiased risk estimation (SURE). The SMPI is three times more effective compared to the wavelet based generalized likelihood estimation approach. The quantitative evaluation and clinical validation reveal that the filters such as the nonlocal mean, posterior sampling based Bayesian estimation, hybrid median, and probabilistic patch based filters are acceptable whereas median, anisotropic diffusion, fuzzy, and Ripplet nonlinear approximation filters have limited applications for echocardiographic images. PMID:27298618

  20. Blind Source Parameters for Performance Evaluation of Despeckling Filters

    PubMed Central

    Biradar, Nagashettappa; Dewal, M. L.; Rohit, ManojKumar; Gowre, Sanjaykumar; Gundge, Yogesh

    2016-01-01

    The speckle noise is inherent to transthoracic echocardiographic images. A standard noise-free reference echocardiographic image does not exist. The evaluation of filters based on the traditional parameters such as peak signal-to-noise ratio, mean square error, and structural similarity index may not reflect the true filter performance on echocardiographic images. Therefore, the performance of despeckling can be evaluated using blind assessment metrics like the speckle suppression index, speckle suppression and mean preservation index (SMPI), and beta metric. The need for noise-free reference image is overcome using these three parameters. This paper presents a comprehensive analysis and evaluation of eleven types of despeckling filters for echocardiographic images in terms of blind and traditional performance parameters along with clinical validation. The noise is effectively suppressed using the logarithmic neighborhood shrinkage (NeighShrink) embedded with Stein's unbiased risk estimation (SURE). The SMPI is three times more effective compared to the wavelet based generalized likelihood estimation approach. The quantitative evaluation and clinical validation reveal that the filters such as the nonlocal mean, posterior sampling based Bayesian estimation, hybrid median, and probabilistic patch based filters are acceptable whereas median, anisotropic diffusion, fuzzy, and Ripplet nonlinear approximation filters have limited applications for echocardiographic images. PMID:27298618

  1. Parameter Diversity Induced Multiple Spatial Coherence Resonances and Spiral Waves in Neuronal Network with and Without Noise

    NASA Astrophysics Data System (ADS)

    Li, Yu-Ye; Jia, Bing; Gu, Hua-Guang; An, Shu-Cheng

    2012-05-01

    Diversity in the neurons and noise are inevitable in the real neuronal network. In this paper, parameter diversity induced spiral waves and multiple spatial coherence resonances in a two-dimensional neuronal network without or with noise are simulated. The relationship between the multiple resonances and the multiple transitions between patterns of spiral waves are identified. The coherence degrees induced by the diversity are suppressed when noise is introduced and noise density is increased. The results suggest that natural nervous system might profit from both parameter diversity and noise, provided a possible approach to control formation and transition of spiral wave by the cooperation between the diversity and noise.

  2. Evaluation of muscle injury using magnetic resonance imaging

    NASA Technical Reports Server (NTRS)

    LeBlanc, A. D.; Jaweed, M.; Evans, H.

    1993-01-01

    The objective of this study was to investigate spin echo T2 relaxation time changes in thigh muscles after intense eccentric exercise in healthy men. Spin echo and calculated T2 relaxation time images of the thighs were obtained on several occasions after exercise of one limb; the contralateral limb served as control. Muscle damage was verified by elevated levels of serum creatine kinase (CK). Thirty percent of the time no exercise effect was discernible on the magnetic resonance (MR) images. In all positive MR images (70%) the semitendinosus muscle was positive, while the biceps femoris, short head, and gracilis muscles were also positive in 50% and 25% of the total cases, respectively. The peak T2 relaxation time and serum CK were correlated (r = 0.94, p<0.01); temporal changes in muscle T2 relaxation time and serum CK were similar, although T2 relaxation time remained positive after serum CK returned to background levels. We conclude that magnetic resonance imaging can serve as a useful tool in the evaluation of eccentric exercise muscle damage by providing a quantitative indicator of damage and its resolution as well as the specific areas and muscles.

  3. Performance Evaluation and Parameter Identification on DROID III

    NASA Technical Reports Server (NTRS)

    Plumb, Julianna J.

    2011-01-01

    The DROID III project consisted of two main parts. The former, performance evaluation, focused on the performance characteristics of the aircraft such as lift to drag ratio, thrust required for level flight, and rate of climb. The latter, parameter identification, focused on finding the aerodynamic coefficients for the aircraft using a system that creates a mathematical model to match the flight data of doublet maneuvers and the aircraft s response. Both portions of the project called for flight testing and that data is now available on account of this project. The conclusion of the project is that the performance evaluation data is well-within desired standards but could be improved with a thrust model, and that parameter identification is still in need of more data processing but seems to produce reasonable results thus far.

  4. High-performance lighting evaluated by photobiological parameters.

    PubMed

    Rebec, Katja Malovrh; Gunde, Marta Klanjšek

    2014-08-10

    The human reception of light includes image-forming and non-image-forming effects which are triggered by spectral distribution and intensity of light. Ideal lighting is similar to daylight, which could be evaluated by spectral or chromaticity match. LED-based and CFL-based lighting were analyzed here, proposed according to spectral and chromaticity match, respectively. The photobiological effects were expressed by effectiveness for blue light hazard, cirtopic activity, and photopic vision. Good spectral match provides light with more similar effects to those obtained by the chromaticity match. The new parameters are useful for better evaluation of complex human responses caused by lighting.

  5. Density functional theory computation of Nuclear Magnetic Resonance parameters in light and heavy nuclei

    NASA Astrophysics Data System (ADS)

    Sutter, Kiplangat

    This thesis illustrates the utilization of Density functional theory (DFT) in calculations of gas and solution phase Nuclear Magnetic Resonance (NMR) properties of light and heavy nuclei. Computing NMR properties is still a challenge and there are many unknown factors that are still being explored. For instance, influence of hydrogen-bonding; thermal motion; vibration; rotation and solvent effects. In one of the theoretical studies of 195Pt NMR chemical shift in cisplatin and its derivatives illustrated in Chapter 2 and 3 of this thesis. The importance of representing explicit solvent molecules explicitly around the Pt center in cisplatin complexes was outlined. In the same complexes, solvent effect contributed about half of the J(Pt-N) coupling constant. Indicating the significance of considering the surrounding solvent molecules in elucidating the NMR measurements of cisplatin binding to DNA. In chapter 4, we explore the Spin-Orbit (SO) effects on the 29Si and 13C chemical shifts induced by surrounding metal and ligands. The unusual Ni, Pd, Pt trends in SO effects to the 29Si in metallasilatrane complexes X-Si-(mu-mt)4-M-Y was interpreted based on electronic and relativistic effects rather than by structural differences between the complexes. In addition, we develop a non-linear model for predicting NMR SO effects in a series of organics bonded to heavy nuclei halides. In chapter 5, we extend the idea of "Chemist's orbitals" LMO analysis to the quantum chemical proton NMR computation of systems with internal resonance-assisted hydrogen bonds. Consequently, we explicitly link the relationship between the NMR parameters related to H-bonded systems and intuitive picture of a chemical bond from quantum calculations. The analysis shows how NMR signatures characteristic of H-bond can be explained by local bonding and electron delocalization concepts. One shortcoming of some of the anti-cancer agents like cisplatin is that they are toxic and researchers are looking for

  6. Severe Pulmonary Arterial Hypertension: Comprehensive Evaluation by Magnetic Resonance Imaging

    PubMed Central

    Ibrahim, El-Sayed H.; Bajwa, Abubakr A.

    2015-01-01

    Pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary artery (PA) pressure, which negatively affects the right ventricular (RV) function. This report shows a patient with severe PAH, on whom a comprehensive MRI exam was performed to evaluate both PA and RV. New imaging sequences were implemented for obtaining additional parameters about the patient's condition. The results show the capabilities of the developed exam of providing complete picture of the cardiovascular system in PAH, which helps the physician optimize treatment. PMID:26435871

  7. Treatment time reduction through parameter optimization in magnetic resonance guided high intensity focused ultrasound treatments

    NASA Astrophysics Data System (ADS)

    Coon, Joshua

    Magnetic Resonance guided High Intensity Focused Ultrasound (MRgHIFU) treatments are a promising modality for cancer treatments in which a focused beam of ultrasound energy is used to kill tumor tissue. However, obstacles still exist to its widespread clinical implementation, including long treatment times. This research demonstrates reductions in treatment times through intelligent selection of the user-controllable parameters, including: the focal zone treatment path, focal zone size, focal zone spacing, and whether to treat one or several focal zone locations at any given time. Several treatments using various combinations of these parameters were simulated using a finite difference method to solve the Pennes bio-heat transfer equation for an ultrasonically heated tissue region with a wide range of acoustic, thermal, geometric, and tumor properties. The total treatment time was iteratively optimized using either a heuristic method or routines included in the Matlab software package, with constraints imposed for patient safety and treatment efficacy. The results demonstrate that large reductions in treatment time are possible through the intelligent selection of user-controllable treatment parameters. For the treatment path, treatment times are reduced by as much as an order of magnitude if the focal zones are arranged into stacks along the axial direction and a middle-front-back ordering is followed. For situations where normal tissue heating constraints are less stringent, these focal zones should have high levels of adjacency to further decrease treatment times; however, adjacency should be reduced in some cases where normal tissue constraints are more stringent. Also, the use of smaller, more concentrated focal zones produces shorter treatment times than larger, more diluted focal zones, a result verified in an agar phantom model. Further, focal zones should be packed using only a small amount of overlap in the axial direction and with a small gap in the

  8. Cardiac Magnetic Resonance Parameters Predict Transplantation-Free Survival in Patients With Fontan Circulation

    PubMed Central

    Rathod, Rahul H.; Prakash, Ashwin; Kim, Yuli Y.; Germanakis, Ioannis E.; Powell, Andrew J.; Gauvreau, Kimberlee; Geva, Tal

    2014-01-01

    Background Several clinical risk factors for death and heart transplantation have been identified in patients with Fontan circulation. It is unknown whether cardiac magnetic resonance (CMR) measurements of ventricular size and function are independently associated with these outcomes and further improve risk stratification. Methods and Results Data on Fontan patients who had a CMR study from 1/2002 to 1/2011 were retrospectively reviewed. The endpoint was time to death or listing for heart transplantation after the CMR study. The median age of the 215 patients was 18.3 years [25th, 75th percentiles: 14, 26] with a median age at Fontan of 3.6 years [2.3, 7.1]. Over a median post-CMR follow-up period of 4.1 years [2.6, 6.2], 24 patients (11%) reached the endpoint: 20 deaths, 3 transplants, and 1 transplant listing. In a multivariable Cox regression model with clinical parameters only, protein losing enteropathy (PLE) was associated with transplant-free survival. A multivariable model including clinical and CMR parameters showed that in addition to PLE, ventricular end-diastolic volume (EDVi) >125 mL/BSA1.3 was associated with transplant-free survival. A likelihood-ratio test comparing the 2 models showed that the addition of EDVi resulted in a significantly improved endpoint prediction (P<0.001) — C-index increased from 0.63 to 0.79. Conclusions CMR-derived ventricular EDVi is an independent predictor of transplant-free survival late after the Fontan operation and adds incremental value over clinical symptoms alone for risk stratification. PMID:24619103

  9. Crossing resonance of wave fields in a medium with an inhomogeneous coupling parameter

    SciTech Connect

    Ignatchenko, V. A. Polukhin, D. S.

    2013-11-15

    The dynamic susceptibilities (Green functions) of the system of two coupled wave fields of different physical natures in a medium with an arbitrary relation between the mean value ε and rms fluctuation Δε of the coupling parameter have been examined. The self-consistent approximation involving all diagrams with noncrossing correlation lines has been developed for the case where the initial Green’s function of the homogeneous medium describes the system of coupled wave fields. The analysis has been performed for spin and elastic waves. Expressions have been obtained for the diagonal elements G{sub mm} and G{sub uu} of the matrix Green’s function, which describe spin and elastic waves in the case of magnetic and elastic excitations, and for the off-diagonal elements G{sub mu} and G{sub um}, which describe these waves in the case of cross excitation. Change in the forms of these elements has been numerically studied for the case of one-dimensional inhomogeneities with an increase in Δε and with a decrease in ε under the condition that the sum of the squares of these quantities is conserved: two peaks in the frequency dependences of imaginary parts of G{sub mm} and G{sub uu} are broadened and then joined into one broad peak; a fine structure appears in the form of narrow resonance at the vertex of the Green’s function of one wave field and narrow antiresonance at the vertex of the Green function of the other field; peaks of the fine structure are broadened and then disappear with an increase in the correlation wavenumber of the inhomogeneities of the coupling parameter; and the amplitudes of the off-diagonal elements vanish in the limit ε → 0.

  10. A Mathematical Assessment of the Precision of Parameters in Measuring Resonance Spectra

    NASA Astrophysics Data System (ADS)

    Golding, Elke M.; Golding, Raymund M.

    1998-12-01

    The accurate interpretation ofin vivomagnetic resonance spectroscopy (MRS) spectra requires a complete understanding of the associated noise-induced errors. In this paper, we address the effect of complex correlated noise patterns on the measurement of a set ofpeakparameters. This is examined initially at the level of a single spectral analysis followed by addressing the noise-induced errors associated with determining thesignalparameters from thepeakparameters. We describe a relatively simple method for calculating these errors for any correlated noise pattern in terms of the noise standard deviation and correlation length. The results are presented in such a way that an estimate of the errors may be made from a single MRS spectrum. We also explore how, under certain circumstances, the lineshape of the signal may be determined. We then apply these results to reexamine a set ofin vivo31P MRS spectra obtained from rat brain prior to and following moderate fluid percussion injury. The approach outlined in this paper will demonstrate how meaningful results may be obtained from spectra where the signal-to-noise ratio (SNR) is quite small and where knowledge of the precise shape of the signal and the detail of the noise pattern is unknown. In essence, we show how to determine the expected errors in the spectral parameters from an estimate of the SNR from a single spectrum, thereby allowing a more discriminative interpretation of the data.

  11. Measurement of Resonance Parameters of Orbitally Excited Narrow B^0 Mesons

    SciTech Connect

    Aaltonen, : T.

    2008-09-01

    The authors report a measurement of resonance parameters of the orbitally excited (L = 1) narrow B{sup 0} mesons in decays to B{sup (*)+}{pi}{sup -} using 1.7 fb{sup -1} of data collected by the CDF II detector at the Fermilab Tevatron. The mass and width of the B*{sub 2}{sup 0} state are measured to be m(B*{sub 2}{sup 0}) = 5740.2{sub -1.8}{sup +1.7}(stat.){sub -0.8}{sup +0.9}(syst.) MeV/c{sup 2} and {Lambda}(B*{sub 2}{sup 0}) = 22.7{sub -3.2}{sup +3.8}(stat.){sub -10.2}{sup +3.2}(syst.) MeV/c{sub 2}. The mass difference between the B*{sub 2}{sup 0} and B{sub 1}{sup 0} states is measured to be 14.9{sub -2.5}{sup +2.2}(stat.){sub -1.4}{sup +1.2}(syst.) MeV/c{sup 2}, resulting in a B{sub 1}{sup 0} mass of 5725.3{sub -2.2}{sup +1.6}(stat.){sub -1.5}{sup +1.4}(syst.) MeV/c{sup 2}. This is currently the most precise measurement of the masses of these states and the first measurement of the B*{sub 2}{sup 0} width.

  12. Characterization of plasma parameters, first beam results, and status of electron cyclotron resonance source

    SciTech Connect

    Jain, S. K.; Jain, Akhilesh; Hannurkar, P. R.; Kotaiah, S.

    2007-05-15

    Electron cyclotron resonance (ECR) plasma source at 50 keV, 30 mA proton current has been designed, fabricated, and assembled. Its plasma study has been done. Plasma chamber was excited with 350 W of microwave power at 2450 MHz, along with nitrogen and hydrogen gases. Microwave power was fed to the plasma chamber through waveguide. Plasma density and electron temperature were studied under various operating conditions, such as magnetic field, gas pressure, and transversal distance. Langmuir probe was used for plasma characterization using current-voltage variation. The nitrogen plasma density calculated was approximately 4.5x10{sup 11} cm{sup -3}, and electron temperatures of 3-10 eV (cold) and 45-85 eV (hot) were obtained. The total ion beam current of 2.5 mA was extracted, with two-electrode extraction geometry, at 15 keV beam energy. The optimization of the source is under progress to extract 30 mA proton beam current at 50 keV beam energy, using three-electrode extraction geometry. This source will be used as an injector to continuous wave radio frequency quadrupole, a part of 100 MeV proton linac. The required root-mean-square normalized beam emittance is less than 0.2{pi} mm mrad. This article presents the study of plasma parameters, first beam results, and status of ECR proton source.

  13. Characterization of plasma parameters, first beam results, and status of electron cyclotron resonance source.

    PubMed

    Jain, S K; Jain, Akhilesh; Hannurkar, P R; Kotaiah, S

    2007-05-01

    Electron cyclotron resonance (ECR) plasma source at 50 keV, 30 mA proton current has been designed, fabricated, and assembled. Its plasma study has been done. Plasma chamber was excited with 350 W of microwave power at 2450 MHz, along with nitrogen and hydrogen gases. Microwave power was fed to the plasma chamber through waveguide. Plasma density and electron temperature were studied under various operating conditions, such as magnetic field, gas pressure, and transversal distance. Langmuir probe was used for plasma characterization using current-voltage variation. The nitrogen plasma density calculated was approximately 4.5 x 10(11) cm(-3), and electron temperatures of 3-10 eV (cold) and 45-85 eV (hot) were obtained. The total ion beam current of 2.5 mA was extracted, with two-electrode extraction geometry, at 15 keV beam energy. The optimization of the source is under progress to extract 30 mA proton beam current at 50 keV beam energy, using three-electrode extraction geometry. This source will be used as an injector to continuous wave radio frequency quadrupole, a part of 100 MeV proton linac. The required root-mean-square normalized beam emittance is less than 0.2pi mm mrad. This article presents the study of plasma parameters, first beam results, and status of ECR proton source.

  14. Measurement of resonance parameters of orbitally excited narrow B0 mesons.

    PubMed

    Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; González, B Alvarez; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzurri, P; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beringer, J; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burke, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Chwalek, T; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cordelli, M; Cortiana, G; Cox, C A; Cox, D J; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Derwent, P F; di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Elagin, A; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Genser, K; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; da Costa, J Guimaraes; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Han, B-Y; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hays, C; Heck, M; Heijboer, A; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhr, T; Kulkarni, N P; Kurata, M; Kusakabe, Y; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, E; Lee, H S; Lee, S W; Leone, S; Lewis, J D; Lin, C-S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lucchesi, D; Luci, C; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Merkel, P; Mesropian, C; Miao, T; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moggi, N; Moon, C S; Moore, R; Morello, M J; Morlok, J; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Nett, J; Neu, C; Neubauer, M S; Neubauer, S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Griso, S Pagan; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Peiffer, T; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Rekovic, V; Renton, P; Renz, M; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Stuart, D; Suh, J S; Sukhanov, A; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Tourneur, S; Trovato, M; Tsai, S-Y; Tu, Y; Turini, N; Ukegawa, F; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wagner-Kuhr, J; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Weinelt, J; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Würthwein, F; Wynne, S M; Xie, S; Yagil, A; Yamamoto, K; Yamaoka, J; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zhang, X; Zheng, Y; Zucchelli, S

    2009-03-13

    We report a measurement of resonance parameters of the orbitally excited (L=1) narrow B0 mesons in decays to B;{(*)+}pi;{-} using 1.7 fb;{-1} of data collected by the CDF II detector at the Fermilab Tevatron. The mass and width of the B_{2};{*0} state are measured to be m(B_{2};{*0})=5740.2_{-1.8};{+1.7}(stat)-0.8+0.9(syst) MeV/c;{2} and Gamma(B_{2};{*0})=22.7_{-3.2};{+3.8}(stat)-10.2+3.2(syst) MeV/c;{2}. The mass difference between the B_{2};{*0} and B10 states is measured to be 14.9_{-2.5};{+2.2}(stat)-1.4+1.2(syst) MeV/c;{2}, resulting in a B10 mass of 5725.3_{-2.2};{+1.6}(stat)-1.5+1.4(syst) MeV/c;{2}. This is currently the most precise measurement of the masses of these states and the first measurement of the B_{2};{*0} width.

  15. A laboratory study to estimate pore geometric parameters of sandstones using complex conductivity and nuclear magnetic resonance for permeability prediction

    NASA Astrophysics Data System (ADS)

    Osterman, Gordon; Keating, Kristina; Binley, Andrew; Slater, Lee

    2016-06-01

    We estimate parameters from the Katz and Thompson permeability model using laboratory complex electrical conductivity (CC) and nuclear magnetic resonance (NMR) data to build permeability models parameterized with geophysical measurements. We use the Katz and Thompson model based on the characteristic hydraulic length scale, determined from mercury injection capillary pressure estimates of pore throat size, and the intrinsic formation factor, determined from multisalinity conductivity measurements, for this purpose. Two new permeability models are tested, one based on CC data and another that incorporates CC and NMR data. From measurements made on forty-five sandstone cores collected from fifteen different formations, we evaluate how well the CC relaxation time and the NMR transverse relaxation times compare to the characteristic hydraulic length scale and how well the formation factor estimated from CC parameters compares to the intrinsic formation factor. We find: (1) the NMR transverse relaxation time models the characteristic hydraulic length scale more accurately than the CC relaxation time (R2 of 0.69 and 0.33 and normalized root mean square errors (NRMSE) of 0.16 and 0.21, respectively); (2) the CC estimated formation factor is well correlated with the intrinsic formation factor (NRMSE=0.23). We demonstrate that that permeability estimates from the joint-NMR-CC model (NRMSE=0.13) compare favorably to estimates from the Katz and Thompson model (NRMSE=0.074). This model advances the capability of the Katz and Thompson model by employing parameters measureable in the field giving it the potential to more accurately estimate permeability using geophysical measurements than are currently possible.

  16. Orbital cavernous hemangiomas: ultrasound and magnetic resonance imaging evaluation.

    PubMed

    Diamantopoulou, A; Damianidis, Ch; Kyriakou, V; Kotziamani, N; Emmanouilidou, M; Goutsaridou, F; Tsitouridis, I

    2010-03-01

    Cavernous hemangioma is the most common intraorbital lesion in adults. The aim of our study was to evaluate the magnetic resonance imaging (MRI) and ultrasound (US) characteristics of cavernous hemangioma and their role in the differential diagnosis of orbital tumors. Eight patients with orbital cavernous hemangiomas, five women and three men with a mean age of 48 years were examined in a period of six years. All patients underwent MRI examination and four patients were also evaluated by US. In all cases MRI depicted a well-defined intraconal tumor. The lesions were homogeneous, isointense to muscle on T1-weighted sequence and hyperintense to muscle on T2-weighted sequence in six patients. In one patient the mass was isointense on T1WI with heterogeneous signal intensity on T2WI and in one patient the lesion had heterogeneous signal intensity on both T1- and T2-weighted sequences. After intravenous contrast medium administration, the tumors showed initial inhomogeneous enhancement with progressive accumulation of contrast material on delayed images in seven patients and initial homogeneous enhancement in one patient. On ultrasonography, the orbital masses appeared slightly hyperechoic, heterogeneous with small areas of slow blood flow. The analysis of imaging characteristics of a well-defined intraconal lesion in an adult patient with painless progressive proptosis can be highly suggestive of the diagnosis of cavernous hemangioma.

  17. Computer-assisted evaluation of contrast kinetics for detection of hepatocellular carcinoma on magnetic resonance imaging.

    PubMed

    Chaturvedi, Abhishek; Bhargava, Puneet; Kolokythas, Orpheus; Mitsumori, Lee M; Maki, Jeffrey H

    2015-01-01

    The purpose of this study was to assess the use of semiquantitative contrast-enhanced parameter analysis as an objective criteria for improving the magnetic resonance (MR) evaluation of hepatocellular carcinoma (HCC) in patients with cirrhosis. Contrast-enhanced MR examination findings from 19 patients with 21 pathologically proven HCC were evaluated using a dedicated liver image postprocessing workstation. Contrast-enhancement kinetic curves were created for each lesion, and 4 enhancement parameters (arterial wash-in slope, arterial-portal slope, arterial-equilibrium slope, and portal-equilibrium slope) were defined from the signal intensity-time plots. The accuracy of each enhancement parameter for the characterization of HCC was assessed. Statistical analysis revealed that an arterial-phase wash-in slope percentage value >1.35 per sec had a sensitivity of 86%, a specificity of 71%, and an accuracy of 79% for the correct characterization of HCC, whereas an arterial-equilibrium wash-out slope percentage value<0.05 per sec had a sensitivity of 86%, a specificity of 81%, and an accuracy of 83%. Although there were significant differences among all groups, the greatest accuracy for differentiation based on receiver operating curve analysis appears to be with arterial and arterial-equilibrium phases. Semiquantitative analysis of lesion contrast kinetics could provide objective parameters to improve the characterization of HCC on contrast-enhanced MR images.

  18. TRITOX: a multiple parameter evaluation of tritium toxicity

    SciTech Connect

    Carsten, A.L.

    1982-01-01

    The increased use of nuclear reactors for power generation will lead to the introduction of tritium into the environment. The need for assessing possible immediate and long-term effects of exposure to this tritium led to the development of a broad program directed towards evaluating the possible somatic and genetic effects of continuous exposure to tritiated water (HTO). Among the parameters measured are the genetic, cytogenetic, reproductive efficiency, growth, nonspecific lifetime shortening, bone marrow cellularity and stem cell content, relative biological effectiveness as compared to /sup 137/Cesium gamma exposure, and related biochemical and microdosimetric evaluations. These parameters have been evaluated on animals maintained on HTO at 10 to 100 times the maximum permissible concentration (0.03 - 3.0 ..mu..Ci/ml) for HTO. Dominant lethal mutations, chromosome aberrations in regenerating liver, increased sister chromatid exchanges in bone marrow and reduction in bone marrow stem cell content have been observed at the higher concentrations. The relative biological effectiveness for HTO ingestion as compared to external /sup 137/Cesium gamma exposures has been found to be between 1 and 2.

  19. Evaluating Iron Content and Tissue Microstructure with Off-Resonance Saturation MRI

    NASA Astrophysics Data System (ADS)

    Fahmy, Sherif R.

    We present three magnetic resonance imaging (MRI) studies, each focused on applying off-resonance saturation (ORS) imaging to a different context or application. Particularly, we are interested in using ORS to evaluate the uptake of superparamagnetic MRI contrast agents in biological tissue, and to evaluate endogenous iron content. This relies on ORS being applied at low off-resonance frequency offsets where most of the negative contrast is due to signal loss from direct saturation of the water content of the sample. Additionally, we wish to combine this information with magnetization transfer contrast, which is obtained by applying ORS at offsets that are far from the resonance frequency, where magnetization transfer (MT) becomes the dominant effect rather than direct saturation (DS). In the first study, we observed the uptake of ultra-small superparamagnetic iron oxide (USPIO) nanoparticles in a simple model system by imaging the uptake in healthy murine liver in vivo, and by testing different metrics to quantify the uptake. Through this process, we discovered an approach that provides high sensitivity and specificity in low-signal scenarios. In the second study, we evaluated image contrast between brain regions in healthy human adults, and related these to the expected iron content in different regions based on age. Images were evaluated based on different MRI contrast mechanisms including quantitative transverse relaxation rates, as well as parameters obtained from ORS imaging. We also performed a field inhomogeneity adjustment on low-offset ORS data using the information obtained from the coarsely sampled ORS spectrum, and this was sufficient to correct for the inhomogeneities. In the third study, we used transverse relaxation, DS - which is strongly dependent on iron content, and MT contrast, in order to classify ex vivo brain samples having Alzheimer's disease pathology and normal controls, and were able to find strong classifiers. The three studies helped

  20. Assessment of uncertainty in parameter evaluation and prediction.

    PubMed

    Meinrath, G; Ekberg, C; Landgren, A; Liljenzin, J O

    2000-02-01

    Like in all experimental science, chemical data is affected by the limited precision of the measurement process. Quality control and traceability of experimental data require suitable approaches to express properly the degree of uncertainty. Noise and bias are nuisance effects reducing the information extractable from experimental data. However, because of the complexity of the numerical data evaluation in many chemical fields, often mean values from data analysis, e.g. multi-parametric curve fitting, are reported only. Relevant information on the interpretation limits, e.g. standard deviations or confidence limits, are either omitted or estimated. Modern techniques for handling of uncertainty in both parameter evaluation and prediction are strongly based on the calculation power of computers. Advantageously, computer-intensive methods like Monte Carlo resampling and Latin Hypercube sampling do not require sophisticated and often unavailable mathematical treatment. The statistical concepts are introduced. Applications of some computer-intensive statistical techniques to chemical problems are demonstrated. PMID:18967855

  1. Evaluation of selected biomechanical parameters in female team sports players.

    PubMed

    Pietraszewski, Bogdan; Struzik, Artur

    2013-01-01

    The aim of this research was to evaluate the biomechanical parameters of lower limbs and their influence on height of vertical jump. The research was conducted on a group of females practicing basketball and volleyball. The following equipment was used during the experiment: a force plate by Kistler, a Biometrics electrogoniometer and a specially designed chair to measure static torque by OPIW Opole. The results indicated that the jumping abilities of the examined athletes were poor. No statistically significant correlations were observed between knee static torque and heights of vertical jumps: CMJ and DJ. The authors suggest modification of the McClymont index (RSI) to evaluate the selection of platform height during plyometric training. Such modification would enable better choice of loads and better training control of the subject.

  2. Analytical modeling of Schumann resonance and ELF propagation parameters on Mars with a multi-layered ground

    NASA Astrophysics Data System (ADS)

    Kozakiewicz, Joanna; Kulak, Andrzej; Mlynarczyk, Janusz

    2015-11-01

    Two electrically conductive planetary spheres, the ionosphere and the ground, form a spherical waveguide. Within such a planetary cavity a phenomenon called Schumann resonance (SR) can occur. It is a resonance of extremely low frequency (ELF) electromagnetic waves. The resonance parameters are strongly related to the electromagnetic properties of the cavity. On Mars, as there is no liquid water at the planetary surface, the ground has a low conductivity. In such a situation, ELF waves penetrate into the planetary subsurface up to many kilometers depth. To examine the influence of low-conductivity grounds on ELF propagation, we have introduced a recently developed analytical method, which enables to estimate the propagation parameters and explicate their dependence of the ground properties. Since the presented model is fully analytical, it is computationally efficient and can be very useful in finding inverse solutions. To demonstrate the potential of the method, we present the relationship between individual ground properties and the parameters of Schumann resonance. The obtained results indicate that Martian exploration performed by one ELF station located at the planetary surface can reveal, along with the properties of the ionosphere, the existence of liquid water under the Martian surface.

  3. A high-fidelity Monte Carlo evaluation of CANDU-6 safety parameters

    SciTech Connect

    Kim, Y.; Hartanto, D.

    2012-07-01

    Important safety parameters such as the fuel temperature coefficient (FTC) and the power coefficient of reactivity (PCR) of the CANDU-6 (CANada Deuterium Uranium) reactor have been evaluated by using a modified MCNPX code. For accurate analysis of the parameters, the DBRC (Doppler Broadening Rejection Correction) scheme was implemented in MCNPX in order to account for the thermal motion of the heavy uranium nucleus in the neutron-U scattering reactions. In this work, a standard fuel lattice has been modeled and the fuel is depleted by using the MCNPX and the FTC value is evaluated for several burnup points including the mid-burnup representing a near-equilibrium core. The Doppler effect has been evaluated by using several cross section libraries such as ENDF/B-VI, ENDF/B-VII, JEFF, JENDLE. The PCR value is also evaluated at mid-burnup conditions to characterize safety features of equilibrium CANDU-6 reactor. To improve the reliability of the Monte Carlo calculations, huge number of neutron histories are considered in this work and the standard deviation of the k-inf values is only 0.5{approx}1 pcm. It has been found that the FTC is significantly enhanced by accounting for the Doppler broadening of scattering resonance and the PCR are clearly improved. (authors)

  4. Comprehensive evaluation of fracture parameters by dual laterolog data

    NASA Astrophysics Data System (ADS)

    Saboorian-Jooybari, Hadi; Dejam, Morteza; Chen, Zhangxin; Pourafshary, Peyman

    2016-08-01

    Reservoir quality and productivity of tight formations depend heavily on the degree of fracture development. In fact, hard and dense carbonate formations may not be considered as net pay without the presence of fractures that convey fluids towards the wellbore. The evaluation of fractures is key to effective reservoir characterization for purposes like well drilling and completion as well as development and simulation of fractured reservoirs. Although imaging technologies such as Formation Micro-Scanners and Imagers (FMS and FMI) provide useful information about fracture properties (i.e., dip angle, porosity, aperture, and permeability), they are very expensive and may not be available in all wells. In this work, fracture parameters are estimated using conventional dual laterolog (DLL) resistivity which includes shallow (LLS) and deep (LLD) responses. This technique is based on electrical resistivity anomalies resulting from the separation of shallow and deep laterolog curves. Fracture parameters that can be calculated by DLL include dip angle, aperture, porosity, permeability, and cementation factor. The accuracy of the parameters calculated using DLL data is validated by the results of FMI in a well in one of the Iranian fractured reservoirs. Contrary to the image logs, the conventional DLL is run routinely in all drilled wells. Therefore, if a reservoir has limited and insufficient data of image logs, as it is often the case, the DLLs can be used as a reliable replacement in the construction of fracture models. Furthermore, DLL has an advantage of deeper evaluation of fractures in comparison with the immediate borehole investigation of image logs.

  5. Evaluation of stable and unstable resonator configurations for efficient second-harmonic laser systems

    NASA Technical Reports Server (NTRS)

    Williams-Byrd, Julie A.; Barnes, Norman P.

    1992-01-01

    A comparative evaluation of a stable resonator, self-filtering unstable resonator, and an unstable resonator with a graded reflectivity mirror (GRM) as the output coupler is presented. The GRM resonator produced a slope efficiency of 1.4 percent, best beam quality (1.4 times diffraction limit), and highest conversion efficiency (50 percent). Other accomplishments include determination of the importance of measuring thermal focusing when designing unstable resonators, development of techniques in measuring thermal focusing and birefringence in laser materials, and development of a high brightness laser system for efficient second harmonic conversion.

  6. Neutron Cross Section Processing Methods for Improved Integral Benchmarking of Unresolved Resonance Region Evaluations

    NASA Astrophysics Data System (ADS)

    Walsh, Jonathan A.; Forget, Benoit; Smith, Kord S.; Brown, Forrest B.

    2016-03-01

    In this work we describe the development and application of computational methods for processing neutron cross section data in the unresolved resonance region (URR). These methods are integrated with a continuous-energy Monte Carlo neutron transport code, thereby enabling their use in high-fidelity analyses. Enhanced understanding of the effects of URR evaluation representations on calculated results is then obtained through utilization of the methods in Monte Carlo integral benchmark simulations of fast spectrum critical assemblies. First, we present a so-called on-the-fly (OTF) method for calculating and Doppler broadening URR cross sections. This method proceeds directly from ENDF-6 average unresolved resonance parameters and, thus, eliminates any need for a probability table generation pre-processing step in which tables are constructed at several energies for all desired temperatures. Significant memory reduction may be realized with the OTF method relative to a probability table treatment if many temperatures are needed. Next, we examine the effects of using a multi-level resonance formalism for resonance reconstruction in the URR. A comparison of results obtained by using the same stochastically-generated realization of resonance parameters in both the single-level Breit-Wigner (SLBW) and multi-level Breit-Wigner (MLBW) formalisms allows for the quantification of level-level interference effects on integrated tallies such as keff and energy group reaction rates. Though, as is well-known, cross section values at any given incident energy may differ significantly between single-level and multi-level formulations, the observed effects on integral results are minimal in this investigation. Finally, we demonstrate the calculation of true expected values, and the statistical spread of those values, through independent Monte Carlo simulations, each using an independent realization of URR cross section structure throughout. It is observed that both probability table

  7. Neutron resonance parameters in 155Gd measured with the DANCE γ-ray calorimeter array

    NASA Astrophysics Data System (ADS)

    Baramsai, B.; Mitchell, G. E.; Agvaanluvsan, U.; Bečvář, F.; Bredeweg, T. A.; Chyzh, A.; Couture, A.; Dashdorj, D.; Haight, R. C.; Jandel, M.; Keksis, A. L.; Krtička, M.; O'Donnell, J. M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Walker, C. L.

    2012-02-01

    The 155Gd(n,γ) reaction was measured with the DANCE γ-ray calorimeter at the Los Alamos Neutron Science Center. Spins were determined for the s-wave resonances by analysis of the γ-ray multiplicity distributions. The analysis was performed with a pattern recognition method. The resulting level densities for the J=1 and 2 resonances are in qualitative agreement with the expected 2J + 1 dependence. The average s-wave resonance spacing was determined to be D0=1.62 ± 0.15 eV. Analysis of the neutron resonances with the code sammy yielded the s-wave strength function S0=1.99±0.28×10-4 and the average total radiative width Γγ = 120 ± 3 meV.

  8. Experimental evaluation of the twofold electromagnetic enhancement theory of surface-enhanced resonance Raman scattering

    SciTech Connect

    Yoshida, Ken-ichi; Itoh, Tamitake; Biju, Vasudevanpillai; Ishikawa, Mitsuru; Ozaki, Yukihiro

    2009-02-15

    We examined an electromagnetic (EM) theory of surface-enhanced resonance Raman scattering (SERRS) using single Ag nanoaggregates. The SERRS-EM theory is characterized by twofold EM enhancement induced by the coupling of plasmon resonance with both excitation and emission of Raman scattering plus fluorescence. The total emission cross-section spectra of enhanced Raman scattering and enhanced fluorescence were calculated using the following parameters: the spectrum of enhancement factor induced by plasmon resonance, resonance Raman scattering overlapped with fluorescence, and excitation wavelengths. The calculations well agreed with experimental total emission cross-section spectra, thus providing strong indications that the SERRS-EM theory is quantitatively correct.

  9. Evaluating parasite densities and estimation of parameters in transmission systems.

    PubMed

    Heinzmann, D; Torgerson, P R

    2008-09-01

    Mathematical modelling of parasite transmission systems can provide useful information about host parasite interactions and biology and parasite population dynamics. In addition good predictive models may assist in designing control programmes to reduce the burden of human and animal disease. Model building is only the first part of the process. These models then need to be confronted with data to obtain parameter estimates and the accuracy of these estimates has to be evaluated. Estimation of parasite densities is central to this. Parasite density estimates can include the proportion of hosts infected with parasites (prevalence) or estimates of the parasite biomass within the host population (abundance or intensity estimates). Parasite density estimation is often complicated by highly aggregated distributions of parasites within the hosts. This causes additional challenges when calculating transmission parameters. Using Echinococcus spp. as a model organism, this manuscript gives a brief overview of the types of descriptors of parasite densities, how to estimate them and on the use of these estimates in a transmission model.

  10. Evaluation of colour parameters and antioxidant activities of fruit wines.

    PubMed

    Kalkan Yildirim, Hatice

    2006-01-01

    The evaluation of oenological colorimetric indexes, CIELAB parameters, total phenols and antioxidant activities has been studied in different fruit wines made from black mulberry, blackberry, quince, apple, apricot, melon, red raspberry, bilberry, sour cherry and strawberry. The highest value of antioxidant activities and total phenolic contents were determined in bilberry, blackberry and black mulberry wines (61.80%, 1161 mg/l gallic acid equivalents; 60.00%, 1232 mg/l gallic acid equivalents; 58.10%, 1081 mg/l gallic acid equivalents), respectively. The highest values for A420 nm, A520 nm, A620 nm, the proportion of blue, wine colour, wine total colour of pigments, wine polymeric pigment colour and K-K values logarithmic colour intensity) were determined in bilberry fruit wine. Positive correlation was found between antioxidant activities and total phenols (r=0.958, P = 0.001). The results of grouping of different parameters in n-dimensional space with different fruit wines demonstrated the importance of bilberry, blackberry and black mulberry wines as natural antioxidants and colourants. PMID:16849114

  11. Dependence of nuclear quadrupole resonance transitions on the electric field gradient asymmetry parameter for nuclides with half-integer spins

    NASA Astrophysics Data System (ADS)

    Cho, Herman

    2016-09-01

    Allowed transition energies and eigenstate expansions have been calculated and tabulated in numerical form as functions of the electric field gradient asymmetry parameter for the zero field Hamiltonian of quadrupolar nuclides with I = 3 / 2 , 5 / 2 , 7 / 2, and 9 / 2. These results are essential to interpret nuclear quadrupole resonance (NQR) spectra and extract accurate values of the electric field gradient tensors. Applications of NQR methods to studies of electronic structure in heavy element systems are proposed.

  12. Dependence of nuclear quadrupole resonance transitions on the electric field gradient asymmetry parameter for nuclides with half-integer spins

    DOE PAGESBeta

    Cho, Herman

    2016-02-28

    Allowed transition energies and eigenstate expansions have been calculated and tabulated in numerical form as functions of the electric field gradient asymmetry parameter for the zero field Hamiltonian of quadrupolar nuclides with I = 3/2,5/2,7/2, and 9/2. These results are essential to interpret nuclear quadrupole resonance (NQR) spectra and extract accurate values of the electric field gradient tensors. Furthermore, applications of NQR methods to studies of electronic structure in heavy element systems are proposed.

  13. Evaluated 182,183,184,186W Neutron Cross Sections and Covariances in the Resolved Resonance Region

    SciTech Connect

    Pigni, Marco T; Leal, Luiz C

    2015-01-01

    Oak Ridge National Laboratory (ORNL) has recently completed the resonance parameter evaluation of four tungsten isotopes, i.e., 182,183,184,186W, in the neutron energy range of thermal up to several keV. This nuclear data work was performed with support from the US Nuclear Criticality Safety Program (NCSP) in an effort to provide improved tungsten cross section and covariance data for criticality safety analyses. The evaluation methodology uses the Reich-Moore approximation of the R-matrix formalism of the code SAMMY to fit high-resolution measurements performed in 2010 and 2012 at the Geel linear accelerator facility (GELINA), as well as other experimental data sets on natural tungsten available in the EXFOR library. In the analyzed energy range, this work nearly doubles the resolved resonance region (RRR) present in the latest US nuclear data library ENDF/B-VII.1. In view of the interest in tungsten for distinct types of nuclear applications and the relatively homogeneous distribution of the isotopic tungsten—namely, 182W(26.5%), 183W(14.31%), 184W(30.64%), and 186W(28.43%) - the completion of these four evaluations represents a significant contribution to the improvement of the ENDF library. This paper presents an overview of the evaluated resonance parameters and related covariances for total and capture cross sections on the four tungsten isotopes.

  14. Neutron Resonance Parameters of 238U and the Calculated Cross Sections from the Reich-Moore Analysis of Experimental Data in the Neutron Energy Range from 0 keV to 20 keV

    SciTech Connect

    Derrien, H

    2005-12-05

    The neutron resonance parameters of {sup 238}U were obtained from a SAMMY analysis of high-resolution neutron transmission measurements and high-resolution capture cross section measurements performed at the Oak Ridge Electron Linear Accelerator (ORELA) in the years 1970-1990, and from more recent transmission and capture cross section measurements performed at the Geel Linear Accelerator (GELINA). Compared with previous evaluations, the energy range for this resonance analysis was extended from 10 to 20 keV, taking advantage of the high resolution of the most recent ORELA transmission measurements. The experimental database and the method of analysis are described in this report. The neutron transmissions and the capture cross sections calculated with the resonance parameters are compared with the experimental data. A description is given of the statistical properties of the resonance parameters and of the recommended values of the average parameters. The new evaluation results in a slight decrease of the effective capture resonance integral and improves the prediction of integral thermal benchmarks by 70 pcm to 200 pcm.

  15. Evaluation of Hemodynamic Parameters as Predictors of Glaucoma Progression

    PubMed Central

    Janulevičiene, Ingrida; Ehrlich, Rita; Siesky, Brent; Nedzelskienė, Irena; Harris, Alon

    2011-01-01

    Purpose. To evaluate hemodynamic parameters as possible predictors for glaucoma progression. Methods. An 18-month randomized double-masked cohort study including 30 open-angle glaucoma patients receiving fixed-combination treatment with Dorzolamide/Timolol (DTFC) or Latanoprost/Timolol (LTFC) (n = 15 per group) was performed. Intraocular pressure (IOP), arterial blood pressure (BP), ocular and diastolic perfusion pressures (OPP, DPP), color Doppler imaging, pulsatile ocular blood flow analysis, scanning laser polarimetry, and Humphrey visual field evaluations were included. Results. Both treatments showed statistically similar IOP reduction. Six patients in DTFC and 7 in LTFC group met glaucoma progression criteria. DTFC group had higher OPP, DPP, and lower vascular resistivity indices as compared to the LTFC. Progressing patients had higher nerve fiber index, lower systolic BP, OPP, DPP, higher ophthalmic and central retinal artery vascular resistance, and lower pulse volume (P < .05; t-test). Conclusions. Structural changes consistent with glaucoma progression correlate with non-IOP-dependent risk factors. PMID:21577269

  16. Brain magnetic resonance imaging, aerobic power, and metabolic parameters among 30 asymptomatic scuba divers.

    PubMed

    Tripodi, D; Dupas, B; Potiron, M; Louvet, S; Geraut, C

    2004-11-01

    The aim of the study was to evaluate the presence of cerebral lesions in asymptomatic scuba divers and explain the causes of them: potential risk factors associating cardiovascular risk factors, low aerobic capacity, or characteristics of diving (maximum depth, ascent rate). Experienced scuba divers, over 40 years of age, without any decompression sickness (DCS) history were included. We studied 30 scuba divers (instructors) without any clinical symptoms. For all of them, we carried out a clinical examination with fatty body mass determination and we questioned them about their diving habits. A brain Magnetic Resonance imaging (MRI), an assessment of maximal oxygen uptake, glycemia, triglyceridemia, and cholesterolemia were systematically carried out. Cerebral spots of high intensity were found at 33 % in the scuba diving group and 30 % in the control group. In the diving group, abnormalities were related to unsafe scuba-diving or metabolic abnormalities. In our study, we did not find a significant relationship between the lesions of the central nervous system, and the age, depth of the dives, number of dives, and ergometric performances (maximal oxygen uptake, V.O (2max), serum level of blood lactate). Nevertheless, we found a significant relationship between the lesions of the central nervous system and ascent rate faster than 10 meters per minute (r = 0.57; p = 0.003) or presence of high level of cholesterolemia (r = 0.6; p = 0.001). We found concordant results using the Cochran's Test: meaningful link between the number of brain lesions and the speed of decompression (Uexp = 14 < Utable = 43; alpha = 0.05, p < 0.01). We concluded that hyperintensities can be explained by preformed nitrogen gas microbubbles and particularly in presence of cholesterol, when the ascent rate is up to 10 meters per minute. So, it was remarkable to note that asymptomatic patients practicing scuba diving either professionally or recreationally, presented lesions of the central nervous

  17. Evaluation of Handwriting Movement Kinematics: From an Ecological to a Magnetic Resonance Environment

    PubMed Central

    Bisio, Ambra; Pedullà, Ludovico; Bonzano, Laura; Ruggeri, Piero; Brichetto, Giampaolo; Bove, Marco

    2016-01-01

    Writing is a means of communication which requires complex motor, perceptual, and cognitive skills. If one of these abilities gets lost following traumatic events or due to neurological diseases, handwriting could deteriorate. Occupational therapy practitioners provide rehabilitation services for people with impaired handwriting. However, to determine the effectiveness of handwriting interventions no studies assessed whether the proposed treatments improved the kinematics of writing movement or had an effect at the level of the central nervous system. There is need to find new quantitative methodologies able to describe the behavioral and the neural outcomes of the rehabilitative interventions for handwriting. In the present study we proposed a combined approach that allowed evaluating the kinematic parameters of handwriting movements, acquired by means of a magnetic resonance-compatible tablet, and their neural correlates obtained simultaneously from a functional magnetic resonance imaging examination. Results showed that the system was reliable in term of reproducibility of the kinematic data during a test/re-test procedure. Further, despite the modifications with respect to an ecological writing movement condition, the kinematic parameters acquired inside the MR-environment were descriptive of individuals’ movement features. At last, the imaging protocol succeeded to show the activation of the cerebral regions associated with the production of writing movement in healthy people. From these findings, this methodology seems to be promising to evaluate the handwriting movement deficits and the potential alterations in the neural activity in those individuals who have handwriting difficulties. Finally, it would provide a mean to quantitatively assess the effect of a rehabilitative treatment. PMID:27746727

  18. Electrochemical evaluation of glutathione S-transferase kinetic parameters.

    PubMed

    Enache, Teodor Adrian; Oliveira-Brett, Ana Maria

    2015-02-01

    Glutathione S-transferases (GSTs), are a family of enzymes belonging to the phase II metabolism that catalyse the formation of thioether conjugates between the endogenous tripeptide glutathione and xenobiotic compounds. The voltammetric behaviour of glutathione (GSH), 1-chloro-2,4-dinitrobenzene (CDNB) and glutathione S-transferase (GST), as well as the catalytic conjugation reaction of GSH to CDNB by GST was investigated at room temperature, T=298.15K (25°C), at pH6.5, for low concentration of substrates and enzyme, using differential pulse (DP) voltammetry at a glassy carbon electrode. Only GSH can be oxidized; a sensitivity of 0.14nA/μM and a LOD of 6.4μM were obtained. The GST kinetic parameter electrochemical evaluation, in relation to its substrates, GSH and CDNB, using reciprocal Michaelis-Menten and Lineweaver-Burk double reciprocal plots, was determined. A value of KM~100μM was obtained for either GSH or CDNB, and Vmax varied between 40 and 60μmol/min per mg of GST.

  19. A new method of evaluating tight gas sands pore structure from nuclear magnetic resonance (NMR) logs

    NASA Astrophysics Data System (ADS)

    Xiao, Liang; Mao, Zhi-qiang; Xie, Xiu-hong

    2016-04-01

    Tight gas sands always display such characteristics of ultra-low porosity, permeability, high irreducible water, low resistivity contrast, complicated pore structure and strong heterogeneity, these make that the conventional methods are invalid. Many effective gas bearing formations are considered as dry zones or water saturated layers, and cannot be identified and exploited. To improve tight gas sands evaluation, the best method is quantitative characterizing rock pore structure. The mercury injection capillary pressure (MICP) curves are advantageous in predicting formation pore structure. However, the MICP experimental measurements are limited due to the environment and economy factors, this leads formation pore structure cannot be consecutively evaluated. Nuclear magnetic resonance (NMR) logs are considered to be promising in evaluating rock pore structure. Generally, to consecutively quantitatively evaluate tight gas sands pore structure, the best method is constructing pseudo Pc curves from NMR logs. In this paper, based on the analysis of lab experimental results for 20 core samples, which were drilled from tight gas sandstone reservoirs of Sichuan basin, and simultaneously applied for lab MICP and NMR measurements, the relationships of piecewise power function between nuclear magnetic resonance (NMR) transverse relaxation T2 time and pore-throat radius Rc are established. A novel method, which is used to transform NMR reverse cumulative curve as pseudo capillary pressure (Pc) curve is proposed, and the corresponding model is established based on formation classification. By using this model, formation pseudo Pc curves can be consecutively synthesized. The pore throat radius distribution, and pore structure evaluation parameters, such as the average pore throat radius (Rm), the threshold pressure (Pd), the maximum pore throat radius (Rmax) and so on, can also be precisely extracted. After this method is extended into field applications, several tight gas

  20. Magnetic Resonance Imaging (MRI) Evaluation of Perianal Fistulae with Surgical Correlation

    PubMed Central

    Singh, Navdeep; Thukral, CL; Singh, Kunwar Pal; Bhalla, Varun

    2014-01-01

    Aims: The purpose of the study was to evaluate the role of Magnetic Resonance Imaging in detection and characterization of perianal fistulae and correlating it with surgical findings. Methods: Fifty consecutive patients with suspected perianal fistulae having one or more external openings were prospectively selected for MRI evaluation. Previously operated or patients with recurrent perianal disease were excluded from the study. MRI findings were recorded according to “St. James’s University Hospital MR Imaging Classification of Perianal Fistulae” and correlated with surgical observations. Finally, comparison between T2-weighted fat saturated and postcontrast T1-weighted fat saturated sequences was done. Results: Amongst the total of 50 patients, per-operative findings confirmed perianal fistulae in 45 patients. The sensitivity and specificity of MRI in correctly detecting and grading the primary tract was found to be 95.56% and 80% respectively; for abscess, it was 87.50% and 95.24% respectively. High sensitivity was also discerned in identification of secondary tract (93.75%), correct localization of internal opening (95.83%) and for correctly detecting the horse-shoeing (87.50%). Our assumption of null hypothesis was accepted on comparing results of T2-weighted fat saturated sequences and postcontrast T1-weighted fat saturated sequences. Conclusion: Magnetic Resonance Imaging (MRI) was highly accurate in assessment of surgically important parameters (primary tract and its grading, internal opening, secondary tract, abscess, horseshoeing) of perianal fistulae. Comparison of results of imaging findings on T2-weighted and postcontrast T1-weighted fat saturated sequences were statistically similar, so contrast study can be omitted, particularly while evaluating primary / previously unoperated perianal fistulae. PMID:25121040

  1. Generalized Parameter-Adjusted Stochastic Resonance of Duffing Oscillator and Its Application to Weak-Signal Detection.

    PubMed

    Lai, Zhi-Hui; Leng, Yong-Gang

    2015-01-01

    A two-dimensional Duffing oscillator which can produce stochastic resonance (SR) is studied in this paper. We introduce its SR mechanism and present a generalized parameter-adjusted SR (GPASR) model of this oscillator for the necessity of parameter adjustments. The Kramers rate is chosen as the theoretical basis to establish a judgmental function for judging the occurrence of SR in this model; and to analyze and summarize the parameter-adjusted rules under unmatched signal amplitude, frequency, and/or noise-intensity. Furthermore, we propose the weak-signal detection approach based on this GPASR model. Finally, we employ two practical examples to demonstrate the feasibility of the proposed approach in practical engineering application. PMID:26343671

  2. Generalized Parameter-Adjusted Stochastic Resonance of Duffing Oscillator and Its Application to Weak-Signal Detection

    PubMed Central

    Lai, Zhi-Hui; Leng, Yong-Gang

    2015-01-01

    A two-dimensional Duffing oscillator which can produce stochastic resonance (SR) is studied in this paper. We introduce its SR mechanism and present a generalized parameter-adjusted SR (GPASR) model of this oscillator for the necessity of parameter adjustments. The Kramers rate is chosen as the theoretical basis to establish a judgmental function for judging the occurrence of SR in this model; and to analyze and summarize the parameter-adjusted rules under unmatched signal amplitude, frequency, and/or noise-intensity. Furthermore, we propose the weak-signal detection approach based on this GPASR model. Finally, we employ two practical examples to demonstrate the feasibility of the proposed approach in practical engineering application. PMID:26343671

  3. Generalized Parameter-Adjusted Stochastic Resonance of Duffing Oscillator and Its Application to Weak-Signal Detection.

    PubMed

    Lai, Zhi-Hui; Leng, Yong-Gang

    2015-08-28

    A two-dimensional Duffing oscillator which can produce stochastic resonance (SR) is studied in this paper. We introduce its SR mechanism and present a generalized parameter-adjusted SR (GPASR) model of this oscillator for the necessity of parameter adjustments. The Kramers rate is chosen as the theoretical basis to establish a judgmental function for judging the occurrence of SR in this model; and to analyze and summarize the parameter-adjusted rules under unmatched signal amplitude, frequency, and/or noise-intensity. Furthermore, we propose the weak-signal detection approach based on this GPASR model. Finally, we employ two practical examples to demonstrate the feasibility of the proposed approach in practical engineering application.

  4. Surface Plasmon Resonance Evaluation of Colloidal Metal Aerogel Filters

    NASA Technical Reports Server (NTRS)

    Smith, David D.; Sibille, Laurent; Cronise, Raymond J.; Noever, David A.

    1997-01-01

    Surface plasmon resonance imaging has in the past been applied to the characterization of thin films. In this study we apply the surface plasmon technique not to determine macroscopic spatial variations but rather to determine average microscopic information. Specifically, we deduce the dielectric properties of the surrounding gel matrix and information concerning the dynamics of the gelation process from the visible absorption characteristics of colloidal metal nanoparticles contained in aerogel pores. We have fabricated aerogels containing gold and silver nanoparticles. Because the dielectric constant of the metal particles is linked to that of the host matrix at the surface plasmon resonance, any change 'in the dielectric constant of the material surrounding the metal nanoparticles results in a shift in the surface plasmon wavelength. During gelation the surface plasmon resonance shifts to the red as the average or effective dielectric constant of the matrix increases. Conversely, formation of an aerogel or xerogel through supercritical extraction or evaporation of the solvent produces a blue shift in the resonance indicating a decrease in the dielectric constant of the matrix. From the magnitude of this shift we deduce the average fraction of air and of silica in contact with the metal particles. The surface area of metal available for catalytic gas reaction may thus be determined.

  5. Angiogenesis of uterine cervical carcinoma: characterization by pharmacokinetic magnetic resonance parameters and histological microvessel density with correlation to lymphatic involvement.

    PubMed

    Hawighorst, H; Knapstein, P G; Weikel, W; Knopp, M V; Zuna, I; Knof, A; Brix, G; Schaeffer, U; Wilkens, C; Schoenberg, S O; Essig, M; Vaupel, P; van Kaick, G

    1997-11-01

    Dynamic studies of Gd-based contrast agents in magnetic resonance imaging (MRI) are increasingly being used for tumor characterization as well as therapy response monitoring. Because detailed knowledge regarding the pathophysiological properties, which in turn are responsible for differences in contrast enhancement, remains fairly undetermined, it was the aim of this project to: (a) examine the relationship between contrast-enhanced dynamic MRI-derived characteristics and histological microvessel density counts, a recognized surrogate of tumor angiogenesis, from primary or recurrent cancers of the uterine cervix; and (b) correlate these parameters with lymphatic involvement to characterize tumor aggressiveness in terms of lymphatic spread. Pharmacokinetic parameters (amplitude, A; exchange rate constant, k21) were calculated from a contrast-enhanced dynamic MRI series in 55 patients (ages 25-72 years; mean, 50 years) with biopsy-proven primary (n = 42) or recurrent (n = 13) uterine cervical cancer. Both pharmacokinetic parameters were correlated to histologically determined microvessel density counts (factor VIII-related antigen) and other pathological tumor characteristics obtained from the operative specimens after radical surgery. In addition, the magnetic resonance and histological data were correlated to the presence or absence of lymphatic system involvement. Pharmacokinetic MRI-derived parameters (A and k21) increased with increasing histological microvessel density counts with r = 0.41 and 0.50, respectively. Lymphatic involvement was more comprehensibly assessed by the pharmacokinetic parameter k21 compared with histological microvessel density, resulting in a higher sensitivity, overall accuracy, and comparable specificity. Contrast-enhanced MRI parameters might prove to be applicable for estimation of tumor angiogenesis in uterine cervical cancer; thus, MRI may become an additional tool to characterize malignant progression in terms of lymphatic

  6. Design parameters of a resonant infrared photoconductor with unity quantum efficiency

    NASA Technical Reports Server (NTRS)

    Farhoomand, Jam; Mcmurray, Robert E., Jr.

    1991-01-01

    This paper proposes a concept of a resonant infrared photoconductor that has characteristics of 100 percent quantum efficiency, high photoconductive gain, and very low noise equivalent power. Central to this concept is an establishment of a high-finesse absorption cavity internal to the detector element. A theoretical analysis is carried out, demonstrating this concept and providing some design guidelines. A Ge:Ga FIR detector is presently being fabricated using this approach.

  7. Harvesting rockfall hazard evaluation parameters from Google Earth Street View

    NASA Astrophysics Data System (ADS)

    Partsinevelos, Panagiotis; Agioutantis, Zacharias; Tripolitsiotis, Achilles; Steiakakis, Chrysanthos; Mertikas, Stelios

    2015-04-01

    Rockfall incidents along highways and railways prove extremely dangerous for properties, infrastructures and human lives. Several qualitative metrics such as the Rockfall Hazard Rating System (RHRS) and the Colorado Rockfall Hazard Rating System (CRHRS) have been established to estimate rockfall potential and provide risk maps in order to control and monitor rockfall incidents. The implementation of such metrics for efficient and reliable risk modeling require accurate knowledge of multi-parametric attributes such as the geological, geotechnical, topographic parameters of the study area. The Missouri Rockfall Hazard Rating System (MORH RS) identifies the most potentially problematic areas using digital video logging for the determination of parameters like slope height and angle, face irregularities, etc. This study aims to harvest in a semi-automated approach geometric and qualitative measures through open source platforms that may provide 3-dimensional views of the areas of interest. More specifically, the Street View platform from Google Maps, is hereby used to provide essential information that can be used towards 3-dimensional reconstruction of slopes along highways. The potential of image capturing along a programmable virtual route to provide the input data for photogrammetric processing is also evaluated. Moreover, qualitative characterization of the geological and geotechnical status, based on the Street View images, is performed. These attributes are then integrated to deliver a GIS-based rockfall hazard map. The 3-dimensional models are compared to actual photogrammetric measures in a rockfall prone area in Crete, Greece while in-situ geotechnical characterization is also used to compare and validate the hazard risk. This work is considered as the first step towards the exploitation of open source platforms to improve road safety and the development of an operational system where authorized agencies (i.e., civil protection) will be able to acquire near

  8. Mechanical design parameters for detection of nuclear signals by magnetic resonance force microscopy

    SciTech Connect

    Moore, G.J.; Hanlon, J.A.; Lamartine, B.; Hawley, M.; Solem, J.C.; Signer, S.; Jarmer, J.J.; Penttila, S.; Sillerud, L.O.; Pryputniewicz, R.J.

    1993-10-01

    Recent theoretical work has shown that mechanical detection of magnetic resonance from a single nuclear spin is in principle possible. This theory has recently been experimentally validated by the mechanical detection of electron spin resonance signals using microscale cantilevers. Currently we are extending this technology in an attempt to detect nuclear signals which are extending this technology in an attempt to detect nuclear signals which are three orders of magnitude lower in intensity than electron signals. In order to achieve the needed thousand-fold improvement in sensitivity we have undertaken the development of optimized mechanical cantilevers and highly polarized samples. Finite element modeling is used as a tool to simulate cantilever beam dynamics and to optimize the mechanical properties including Q, resonant frequency, amplitude of vibration and spring constant. Simulations are compared to experiments using heterodyne hologram interferometry. Nanofabrication of optimized cantilevers via ion milling will be directed by the outcome of these simulations and experiments. Highly polarized samples are developed using a three-fold approach: (1) high magnetic field strength (2.5T), (2) low temperature (1K), and (3) use of samples polarized by dynamic nuclear polarization. Our recent experiments have demonstrated nuclear polarizations in excess of 50% in molecules of toulene.

  9. Electrostatic Generation of Bulk Acoustic Waves and Electrical Parameters of Si-MEMS Resonators.

    PubMed

    Dulmet, Bernard; Ivan, Mihaela Eugenia; Ballandras, Sylvain

    2016-02-01

    This paper proposes an analytical approach to model the generation of bulk acoustic waves in an electrostatically excited silicon MEMS structure, as well as its electromechanical response in terms of static and dynamic displacements, electromechanical coupling, and motional current. The analysis pertains to the single-port electrostatic drive of trapped-energy thickness-extensional (TE) modes in thin plates. Both asymmetric single-side and symmetric double-side electrostatic gap configurations are modeled. Green's function is used to describe the characteristic of the static displacement of the driven surface of the structure versus the dc bias voltage, which allows us to determine the electrical response of the resonator. Optical and electrical characterizations have been performed on resonator samples operating at 10.3 MHz on the fundamental of TE mode under single-side electrostatic excitation. The various figures of merit depend on the dc bias voltage. Typical values of 9000 for the Q-factor, and of 10(-5) for the electromechanical coupling factor k(2) have been obtained with [Formula: see text] for [Formula: see text]-thick gaps. Here-considered modes have a typical temperature coefficients of frequency (TCF) close to -30 ppm/(°)C. We conclude that the practical usability of such electrostatically excited bulk acoustic waves (BAW) resonators essentially depends on the efficiency of the compensation of feed-through capacitance.

  10. Electrostatic Generation of Bulk Acoustic Waves and Electrical Parameters of Si-MEMS Resonators.

    PubMed

    Dulmet, Bernard; Ivan, Mihaela Eugenia; Ballandras, Sylvain

    2016-02-01

    This paper proposes an analytical approach to model the generation of bulk acoustic waves in an electrostatically excited silicon MEMS structure, as well as its electromechanical response in terms of static and dynamic displacements, electromechanical coupling, and motional current. The analysis pertains to the single-port electrostatic drive of trapped-energy thickness-extensional (TE) modes in thin plates. Both asymmetric single-side and symmetric double-side electrostatic gap configurations are modeled. Green's function is used to describe the characteristic of the static displacement of the driven surface of the structure versus the dc bias voltage, which allows us to determine the electrical response of the resonator. Optical and electrical characterizations have been performed on resonator samples operating at 10.3 MHz on the fundamental of TE mode under single-side electrostatic excitation. The various figures of merit depend on the dc bias voltage. Typical values of 9000 for the Q-factor, and of 10(-5) for the electromechanical coupling factor k(2) have been obtained with [Formula: see text] for [Formula: see text]-thick gaps. Here-considered modes have a typical temperature coefficients of frequency (TCF) close to -30 ppm/(°)C. We conclude that the practical usability of such electrostatically excited bulk acoustic waves (BAW) resonators essentially depends on the efficiency of the compensation of feed-through capacitance. PMID:26642450

  11. US-based Drug Cost Parameter Estimation for Economic Evaluations

    PubMed Central

    Levy, Joseph F; Meek, Patrick D; Rosenberg, Marjorie A

    2014-01-01

    Introduction In the US, more than 10% of national health expenditures are for prescription drugs. Assessing drug costs in US economic evaluation studies is not consistent, as the true acquisition cost of a drug is not known by decision modelers. Current US practice focuses on identifying one reasonable drug cost and imposing some distributional assumption to assess uncertainty. Methods We propose a set of Rules based on current pharmacy practice that account for the heterogeneity of drug product costs. The set of products derived from our Rules, and their associated costs, form an empirical distribution that can be used for more realistic sensitivity analyses, and create transparency in drug cost parameter computation. The Rules specify an algorithmic process to select clinically equivalent drug products that reduce pill burden, use an appropriate package size, and assume uniform weighting of substitutable products. Three diverse examples show derived empirical distributions and are compared with previously reported cost estimates. Results The shapes of the empirical distributions among the three drugs differ dramatically, including multiple modes and different variation. Previously published estimates differed from the means of the empirical distributions. Published ranges for sensitivity analyses did not cover the ranges of the empirical distributions. In one example using lisinopril, the empirical mean cost of substitutable products was $444 (range $23–$953) as compared to a published estimate of $305 (range $51–$523). Conclusions Our Rules create a simple and transparent approach to create cost estimates of drug products and assess their variability. The approach is easily modified to include a subset of, or different weighting for, substitutable products. The derived empirical distribution is easily incorporated into one-way or probabilistic sensitivity analyses. PMID:25532826

  12. Magnetic resonance imaging evaluation of lipodystrophy in HIV-positive patients receiving highly active antiretroviral therapy.

    PubMed

    Eichler, K; Bickel, T M; Klauke, S; Eisen, J; Vogl, T J; Zangos, S

    2015-07-01

    We evaluated retrospectively an automated method for the separate detection of subcutaneous and visceral fat in the abdominal region by magnetic resonance studies in HIV-positive patients on highly active antiretroviral therapy. The patients were divided into four different groups: lipoatrophy, lipohypertrophy, mixed and the control group. The use of software for the automated detection of abdominal compartment visceral adipose tissue (VAT), total adipose tissue (TAT) and subcutaneous adipose tissue (SAT) was compared to manual evaluation methods (fuzzy C-mean). The results of ROC analysis showed that the parameters, particularly the VAT, are better than the VAT/TAT and at identifying patients with the symptoms of abdominal fat accumulation. A sensitivity of 80.3% and a specificity of 79.5% resulted from a threshold VAT value of >87 cm(2). Moreover, the manual evaluation method was shown to provide greater values for VAT and the VAT/TAT ratio than those given by the automated method. In the present study, a rapid MRI protocol for the detection and assessment of the course of lipodystrophy was presented and tested on a group of patients with signs of HALS, as well as on an antiretroviral naïve control group.

  13. An Analysis Method for Superconducting Resonator Parameter Extraction with Complex Baseline Removal

    NASA Technical Reports Server (NTRS)

    Cataldo, Giuseppe

    2014-01-01

    A new semi-empirical model is proposed for extracting the quality (Q) factors of arrays of superconducting microwave kinetic inductance detectors (MKIDs). The determination of the total internal and coupling Q factors enables the computation of the loss in the superconducting transmission lines. The method used allows the simultaneous analysis of multiple interacting discrete resonators with the presence of a complex spectral baseline arising from reflections in the system. The baseline removal allows an unbiased estimate of the device response as measured in a cryogenic instrumentation setting.

  14. Two statistics for evaluating parameter identifiability and error reduction

    USGS Publications Warehouse

    Doherty, John; Hunt, Randall J.

    2009-01-01

    Two statistics are presented that can be used to rank input parameters utilized by a model in terms of their relative identifiability based on a given or possible future calibration dataset. Identifiability is defined here as the capability of model calibration to constrain parameters used by a model. Both statistics require that the sensitivity of each model parameter be calculated for each model output for which there are actual or presumed field measurements. Singular value decomposition (SVD) of the weighted sensitivity matrix is then undertaken to quantify the relation between the parameters and observations that, in turn, allows selection of calibration solution and null spaces spanned by unit orthogonal vectors. The first statistic presented, "parameter identifiability", is quantitatively defined as the direction cosine between a parameter and its projection onto the calibration solution space. This varies between zero and one, with zero indicating complete non-identifiability and one indicating complete identifiability. The second statistic, "relative error reduction", indicates the extent to which the calibration process reduces error in estimation of a parameter from its pre-calibration level where its value must be assigned purely on the basis of prior expert knowledge. This is more sophisticated than identifiability, in that it takes greater account of the noise associated with the calibration dataset. Like identifiability, it has a maximum value of one (which can only be achieved if there is no measurement noise). Conceptually it can fall to zero; and even below zero if a calibration problem is poorly posed. An example, based on a coupled groundwater/surface-water model, is included that demonstrates the utility of the statistics. ?? 2009 Elsevier B.V.

  15. Cooperative effects of parameter heterogeneity and coupling on coherence resonance in unidirectional coupled brusselator system

    NASA Astrophysics Data System (ADS)

    Li, Qian-Shu; Shi, Jian-Cheng

    2007-01-01

    Two unidirectional coupled brusselator systems, subject to common and uncorrelated multiplicative noise, are investigated, respectively. It can be found that, the parameter heterogeneity effect may be destroyed above critical coupling strength. Synchronization occurs between subsystems subjected to common noise, but cannot achieve by means of uncorrelated noise.

  16. Evaluation of performance parameters of indigenously developed roots pumping system

    NASA Astrophysics Data System (ADS)

    Maqsood, M.; Usman, A.; Bodla, M. F.; Ali, J.

    2016-08-01

    Roots pumping systems are widely used in industries to generate vacuum with high pumping speed. In the present work, the performance parameters of indigenously developed Roots pumping system have been studied. The performance parameters being studied are the ultimate pressure, working temperature, compression ratio and pumping speed. Ultimate pressure of the Roots pump after continuous running of eight hours is found to be 1.1x10-3 mbar. The most important parameter of the roots pump is the zero-gas flow compression Ratio (Ko) which is found to be 18 for the pumping system under study. Efficiency of Roots pump is found to be 76% which is in good agreement as reported in the literature.

  17. Anomalous Solute Transport in Saturated Porous Media: Linking Transport Model Parameters to Electrical and Nuclear Magnetic Resonance Properties

    NASA Astrophysics Data System (ADS)

    Swanson, R. D.; Binley, A. M.; Keating, K.; France, S.; Osterman, G. K.; Day-Lewis, F. D.; Singha, K.

    2013-12-01

    The advection-dispersion equation fails to describe non-Fickian solute transport in saturated porous media, necessitating the use of other models. The dual-domain mass transfer (DDMT) model partitions the total porosity into mobile and less-mobile domains with solute exchange between the domains; consequently, the DDMT model can produce a better fit to breakthrough curves (BTCs) in systems defined by more- and less-mobile components. However, direct experimental estimation of DDMT model parameters such as rate of exchange and the mobile and less-mobile porosities remains elusive. Consequently, model parameters are often calculated purely as a model fitting exercise. There is a clear need for material characterization techniques that can offer some insight into the pore space geometrical arrangement, particularly if such techniques can be extended to the field scale. Here, we interpret static direct-current (DC) resistivity, complex resistivity (CR) and nuclear magnetic resonance (NMR) geophysical measurements in the characterization of mass transfer parameters. We use two different samples of the zeolite clinoptilolite, a material shown to demonstrate solute mass transfer due to a significant intragranular porosity, along with glass beads as a control. We explore the relation between geophysical and DDMT parameters in conjunction with supporting material characterization methods. Our results reveal how these geophysical measurements can offer some insight into the pore structures controlling the observed anomalous transport behavior.

  18. Magnetic resonance evaluation of hydronephrosis in the dog

    SciTech Connect

    Thickman, D.; Kundel, H.; Biery, D.

    1984-07-01

    The ability of magnetic resonance (MR) imaging to detect and distinguish various stages of obstruction in the canine kidney was investigated. MR images were obtained at acute, subacute, and chronic stages of experimentally produced hydronephrosis. The renal cortex was distinguished from the renal medulla in the normal dog and in the acute and subacute stages of hydronephrosis. T1 relaxation times of the renal cortex and medulla were measured in vitro in 14 normal and nine experimental animals. These values were used to compute the amount of tissue contrast between the cortex and medulla and were compared with the degree of corticomedullary differentiation seen in the image. A relationship was noted between increasing T1 values and increasing water content. Corticomedullary contrast decreased with obstruction. The variation in corticomedullary image contracts may be useful for assessing the duration of hydronephrosis.

  19. Magnetic resonance imaging in the evaluation of cognitive function.

    PubMed

    Bigler, Erin D

    2014-10-01

    Image quality of magnetic resonance imaging (MRI) scans of the brain currently approximate gross anatomy as would be viewed at autopsy. During the first decade of the 21st Century incredible advances in image processing and quantification have occurred permitting more refined methods for studying brain-behavior-cognitive functioning. The current presentation overviews the current status of MRI methods for routine clinical assessment of brain pathology, how these techniques identify neuropathology and how pathological findings are quantified. Diffusion tensor imaging (DTI), functional MRI (fMRI), and resting state fMRI are all reviewed, emphasizing how these techniques permit an examination of brain function and connectivity. General regional relationships of brain function associated with cognitive control will be highlighted.

  20. Sexual dimorphism in tooth morphometrics: An evaluation of the parameters

    PubMed Central

    Banerjee, Abhishek; Kamath, Venkatesh V.; Satelur, Krishnanand; Rajkumar, Komali; Sundaram, Lavanya

    2016-01-01

    Aims and Objectives: Sexual dimorphism refers to the variations in tooth size and shape between the sexes. The consistency of these variations is valuable in the identification of the sex of an individual in times of mass disaster when whole body parts get destroyed or are unavailable. There exist differences in the expression of these variables across races and regions. This study aims to tabulate and identify the variations in tooth measurements using standarized reference points in an attempt to establish parameters of sexual dimorphism. Materials and Methods: 100 individuals (50 of each sex) in the age group 19-23 years were assessed for standard morphometric parameters of the maxillary central incisor, canine, premolar and molar. Odontometric measurements of established parameters were recorded from impression casts of the maxillary jaws. The mesiodistal width (MDW), the bucco-ligual width (BLW), the crown length (CL) and the cervical angle (CA) were charted among the teeth. The consistency of the variations was statistically analyzed and a logistic regression table was prepared to identify the sex of the individual from the tooth measurements. Results and Conclusions: The BLW, MDW and CL reflected significant variations among all the teeth to be effective in establishing sexual dimorphism. CA as a parameter was inadequate across all the teeth. The permanent maxillary canine was the most important tooth to be reflective of the gender and statistically significant to be utilized for gender determination. PMID:27051219

  1. The Evaluation of the Parameters in the van Deemter Equation.

    ERIC Educational Resources Information Center

    Moody, Harvey W.

    1982-01-01

    Describes experiment expanding on principles behind measuring efficiency of chromatographic columns and allowing calculation of parameters in the van Deemter equation. Easily accomplished in a three-hour period using a gas chromatograph in which gas flow can be changed and measured. Mathematical solutions can be attained with programmable…

  2. Evaluation of a microwave resonator for predicting grain moisture independent of bulk density

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This work evaluated the ability of a planar whispering mode resonator to predict moisture considering moisture and densities expected in an on-harvester application. A calibration model was developed to accurately predict moisture over the moisture, density and temperature ranges evaluated. This mod...

  3. Determination of GLUT1 Oligomerization Parameters using Bioluminescent Förster Resonance Energy Transfer

    PubMed Central

    Looyenga, Brendan; VanOpstall, Calvin; Lee, Zion; Bell, Jed; Lodge, Evans; Wrobel, Katherine; Arnoys, Eric; Louters, Larry

    2016-01-01

    The facilitated glucose transporter GLUT1 (SLC2A1) is an important mediator of glucose homeostasis in humans. Though it is found in most cell types to some extent, the level of GLUT1 expression across different cell types can vary dramatically. Prior studies in erythrocytes—which express particularly high levels of GLUT1—have suggested that GLUT1 is able to form tetrameric complexes with enhanced transport activity. Whether dynamic aggregation of GLUT1 also occurs in cell types with more modest expression of GLUT1, however, is unclear. To address this question, we developed a genetically encoded bioluminescent Förster resonance energy transfer (BRET) assay using the luminescent donor Nanoluciferase and fluorescent acceptor mCherry. By tethering these proteins to the N-terminus of GLUT1 and performing saturation BRET analysis, we were able to demonstrate the formation of multimeric complexes in live cells. Parallel use of flow cytometry and immunoblotting further enabled us to estimate the density of GLUT1 proteins required for spontaneous oligomerization. These data provide new insights into the physiological relevance of GLUT1 multimerization as well as a new variant of BRET assay that is useful for measuring the interactions among other cell membrane proteins in live cells. PMID:27357903

  4. Qualitative Parameters for Evaluation Procedures of Non-Formal and Informal Learning Achievements

    ERIC Educational Resources Information Center

    Stasiunaitiene, Egle; Kaminskiene, Lina

    2009-01-01

    The article introduces evaluation principles of non-formal and informal learning that determine the quality of evaluation, describes stages of the evaluation procedure, differentiates their qualitative parameters and defines their criteria and indicators. It also brings in the discussion that consideration of qualitative parameters for the…

  5. [Theoretical Investigation of the Electron Paramagnetic Resonance Parameters and Local Structures for Zinc Phosphate Glass Doped with VO2+].

    PubMed

    Li, Chao-ying; Yuang, Xian-Kai; Tu, Qiu; Wang, Wei-yang; Zheng, Xue-mei

    2015-07-01

    As an important model system, 3d(1) ions (VO2+, V4+ et al) have been extensively investigated by means of electron paramagnetic resonance (EPR), and many experimental results of EPR parameters were also measured. The optical absorption and EPR parameters (g factors g||, g⊥ and hyperfine structure constants A||, A⊥) of a tetragonal V4+ center in zinc phosphate glass are theoretically investigated, using the perturbation formulas for a 3d(1) ion in tetragonally compressed octahedra. Since the spin-orbit coupling parameter r (150 cm(-1)) of ligand O2- is close to that ξp(0) (≈248 cm(-1)) of the central 3d(1) ion in zinc phosphate glass doped VO2+, the effect of the spin-orbit coupling parameter ξp(0) on the EPR spectra and optical absorption spectra should be taken into account. In this work, the relationship between the EPR parameters as well as the optical absorption spectra and the local structure of the impurity center are established based on the superposition model. By fitting the calculated EPR parameters and optical absorption spectra for V4+ center in zinc phosphate glass to the experimental data, the local structure parameters of [VO6](8-) cluster are obtained. According to the investigation, the magnitudes of the metal-ligand distances parallel and perpendicular to the C4-axis of [VO6](8-) cluster are, respectively, R|| ≈ 0.175 nm and R⊥ ≈ 0.197 nm, the local structure around the V4+ ions possesses a compressed tetragonal distortion along C4 axis. Theoretical results of EPR parameters and optical absorption spectra are in good agreement with experimental data, the validity of the calculated results has also been discussed. Thus, perturbation method is effective to the studies the EPR parameters and optical spectra of transition-metal 3d ions in crystals. In addition, based on the studies of the hyperfine structure constants (All and A1), one can found that the large value of kappa indicates a large contribution to the hyperfine constant by the

  6. Experimental evaluation of a modal parameter based system identification procedure

    NASA Astrophysics Data System (ADS)

    Yu, Minli; Feng, Ningsheng; Hahn, Eric J.

    2016-02-01

    Correct modelling of the foundation of a rotor bearing foundation system (RBFS) is an invaluable asset for the balancing and efficient running of turbomachinery. Numerical experiments have shown that a modal parameter based identification approach could be feasible for this purpose but there is a lack of experimental verification of the suitability of such a modal approach for even the simplest systems. In this paper the approach is tested on a simple experimental rig comprising a clamped horizontal bar with lumped masses. It is shown that apart from damping, the proposed approach can identify reasonably accurately the relevant modal parameters of the rig; and that the resulting equivalent system can predict reasonably well the frequency response of the rig. Hence, the proposed approach shows promise but further testing is required, since application to identifying the foundation of an RBFS involves the additional problem of accurately obtaining the force excitation from motion measurements.

  7. Anharmonic vibrational frequencies and vibrationally averaged structures and nuclear magnetic resonance parameters of FHF-.

    PubMed

    Hirata, So; Yagi, Kiyoshi; Perera, S Ajith; Yamazaki, Shiori; Hirao, Kimihiko

    2008-06-01

    The anharmonic vibrational frequencies of FHF(-) were computed by the vibrational self-consistent-field, configuration-interaction, and second-order perturbation methods with a multiresolution composite potential energy surface generated by the electronic coupled-cluster method with various basis sets. Anharmonic vibrational averaging was performed for the bond length and nuclear magnetic resonance indirect spin-spin coupling constants, where the latter computed by the equation-of-motion coupled-cluster method. The calculations placed the vibrational frequencies at 580 (nu(1)), 1292 (nu(2)), 1313 (nu(3)), 1837 (nu(1) + nu(3)), and 1864 cm(-1) (nu(1) + nu(2)), the zero-point H-F bond length (r(0)) at 1.1539 A, the zero-point one-bond spin-spin coupling constant [(1)J(0)(HF)] at 124 Hz, and the bond dissociation energy (D(0)) at 43.3 kcal/mol. They agreed excellently with the corresponding experimental values: nu(1) = 583 cm(-1), nu(2) = 1286 cm(-1), nu(3) = 1331 cm(-1), nu(1) + nu(3) = 1849 cm(-1), nu(1) + nu(2) = 1858 cm(-1), r(0) = 1.1522 A, (1)J(0)(HF) = 124+/-3 Hz, and D(0) = 44.4+/-1.6 kcal/mol. The vibrationally averaged bond lengths matched closely the experimental values of five excited vibrational states, furnishing a highly dependable basis for correct band assignments. An adiabatic separation of high- (nu(3)) and low-frequency (nu(1)) stretching modes was examined and found to explain semiquantitatively the appearance of a nu(1) progression on nu(3). Our calculations predicted a value of 186 Hz for experimentally inaccessible (2)J(0)(FF).

  8. Thoughts on standardization of parameters for image evaluation

    NASA Technical Reports Server (NTRS)

    Billingsley, F. C.

    1976-01-01

    Images received for image processing and analysis are obtained from a wide variety of sources and with a wide variety of sensors. Because it is desirable to have image processing algorithms be as universally applicable as possible, they should be designed, where possible, to be insensitive to the parametric variations of the source material. Where this is not possible, these variations must be taken into account. Therefore, it is necessary to consider what parameters may be defined in common across a suite of image types. Objective parameters or measurements of images which, in the proper combinations, may serve as surrogates for real images may be pixel-specific, location dependent, or combinations thereof. Parameters which have proven useful in defining the characteristics of images include the gray scale linearity, granularity of the quantization, spectral content, geometrical fidelity, resolution of the system expressed as either the point spread function or the modulation transfer function, and the spatial frequency content and characteristics of the data itself.

  9. The evaluation of radiation damage parameter for CVD diamond

    NASA Astrophysics Data System (ADS)

    Grilj, V.; Skukan, N.; Jakšić, M.; Pomorski, M.; Kada, W.; Kamiya, T.; Ohshima, T.

    2016-04-01

    There are a few different phenomenological approaches that aim to track the dependence of signal height in irradiated solid state detectors on the fluence of damaging particles. However, none of them are capable to provide a unique radiation hardness parameter that would reflect solely the material capability to withstand high radiation environment. To extract such a parameter for chemical vapor deposited (CVD) diamond, two different diamond detectors were irradiated with proton beams in MeV energy range and subjected afterwards to ion beam induced charge (IBIC) analysis. The change in charge collection efficiency (CCE) due to defects produced was investigated in context of a theoretical model that was developed on the basis of the adjoint method for linearization of the continuity equations of electrons and holes. Detailed modeling of measured data resulted with the first known value of the kσ product for diamond, where k represents the number of charge carriers' traps created per one simulated primary lattice vacancy and σ represents the charge carriers' capture cross section. As discussed in the text, this product could be considered as a true radiation damage parameter.

  10. Optimized Pulse Parameters for Reducing Quantitation Errors Due to Saturation Factor Changes in Magnetic Resonance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Galbán, Craig J.; Spencer, Richard G. S.

    2002-06-01

    We present an analysis of the effects of chemical exchange and changes in T1 on metabolite quantitation for heart, skeletal muscle, and brain using the one-pulse experiment for a sample which is subject to temporal variation. We use an optimization algorithm to calculate interpulse delay times, TRs, and flip angles, θ, resulting in maximal root-mean-squared signal-to-noise per unit time ( S/ N) for all exchanging species under 5 and 10% constraints on quantitation errors. The optimization yields TR and θ pairs giving signal-to-noise per unit time close or superior to typical literature values. Additional simulations were performed to demonstrate explicitly the dependence of the quantitation errors on pulse parameters and variations in the properties of the sample, such as may occur after an intervention. We find that (i) correction for partial saturation in accordance with the usual analysis neglecting variations in metabolite concentrations and rate constants may readily result in quantitation errors of 15% or more; the exact degree of error depends upon the details of the system under consideration; (ii) if T1's vary as well, significantly larger quantitation errors may occur; and (iii) optimal values of pulse parameters may minimize errors in quantitation with minimal S/ N loss.

  11. Evaluation of magnetic resonance sequences in imaging mediastinal tumors

    SciTech Connect

    Webb, W.R.; Gamsu, G.; Stark, D.D.; Moon, K.L. Jr.; Moore, E.H.

    1984-10-01

    Ten patients having a mediastinal tumor were studied with magnetic resonance imaging (MRI) using from two to four imaging sequences. Seven had bronchial carcinoma and three had benign lesions. The sequences included the spin-echo technique with repetition time (TR) values of 0.5, 1.0, and 2.0 sec and echo time (TE) values of 28 and 56 msec, and the inversion-recovery technique. The signal-intensity ratios of the mediastinal mass and mediastinal fat, which are a measure of image contrast, were compared for the different imaging sequences. Also signal-to-noise ratios were measured relative to both mediastinal fat and mediastinal mass. With spin-echo imaging, decreasing the TR value resulted in an increase in mass/fat contrast in all patients, making the masses easier to detect, but this also resulted in decreased signal-to-noise ratios. Inversion-recovery imaging with the sequence used resulted in a greatly increased mass/fat contrast, because of a relative decrease in signal from the mass. Spin-echo imaging with both short and long TR values provides good tissue contrast and good signal-to-noise ratios.

  12. Preliminary resolved resonance region evaluation of copper-63 from 0 to 300 keV

    SciTech Connect

    Sobes, V.; Forget, B.; Leal, L.; Guber, K.

    2012-07-01

    A new preliminary evaluation of Cu-63 was done in the energy region from 0 to 300 keV extending the resolved resonance region of the previous, ENDF/B-VII.0, evaluation three-fold. The new evaluation was based on three experimental transmission data sets; two measured at the Oak Ridge Electron Linear Accelerator (ORELA) and one from the Massachusetts Inst. of Technology Nuclear Reactor (MITR). A total of 275 new resonances were identified and a corresponding set of external resonances was approximated to mock up the external levels. The negative external levels (bound level) were modified to match the thermal cross section values. A preliminary benchmarking calculation was made using 11 ICSBEP benchmarks. This work is in support of the DOE Nuclear Criticality Safety Program. (authors)

  13. A femtogram resolution mass sensor platform, based on SOI electrostatically driven resonant cantilever. Part I: electromechanical model and parameter extraction.

    PubMed

    Teva, J; Abadal, G; Torres, F; Verd, J; Pérez-Murano, F; Barniol, N

    2006-01-01

    A microcantilever based platform for mass detection in the femtogram range has been integrated in the doped top silicon layer of a SOI substrate. The on-plane fundamental resonance mode of the cantilever is excited electrostatically and detected capacitively by means of two parallel placed electrodes in a two port configuration. An electromechanical model of the cantilever-electrodes transducer and its implementation in a SPICE environment are presented. The model takes into account non-linearities from variable cantilever-electrode gap, fringing field contributions and real deflection shape of the cantilever for the calculation of the driving electrostatic force. A fitting of the model to the measured S(21) transmitted power frequency response is performed to extract the characteristic sensor parameters as Young modulus, Q factor, electrical parasitics and mass responsivity.

  14. The far-infrared laser magnetic resonance spectrum of the SiH radical and determination of ground state parameters

    NASA Technical Reports Server (NTRS)

    Brown, J. M.; Curl, R. F.; Evenson, K. M.

    1984-01-01

    The far-infrared laser magnetic resonance spectrum of the SiH radical in the v = O level of its X2Pi state has been recorded. The signals are rather weak. The molecules were generated in the reaction between fluorine atoms and SiH4. Rotational transitions have been detected in both 2Pi1/2 and 2Pi3/2 spin components but no fine structure transitions between the spin components were observed. Proton hyperfine splittings were resolved on some lines. The measurements have been analyzed, subjected to a least-squares fit using an effective Hamiltonian, and the appropriate molecular parameters determined. The weakness of the spectrum and the failure of attempts to power saturate favorable lines are both consistent with a small value for the electric dipole moment for SiH.

  15. Approximating large resonance parameter covariance matrices with group-wise covariance matrices for advanced nuclear fuel cycle applications

    SciTech Connect

    Dunn, Michael E; Leal, Luiz C; Wiarda, Dorothea; Arbanas, Goran

    2008-01-01

    The large size of resonance parameter covariance matrices (RPCM) in the actinide region often renders them impractical for dissemination via ENDF. Therefore, a method of approximating the RPCM by a much smaller group-wise covariance matrix (GWCM) is described, implemented, and examined. In this work, 233U RPCM is used to generate GWCM's for the 44 group AMPX, 100 group GE, 171 group VITAMIN-C, and 240 group CSWEG. Each of these GWCM's is then used to compute group-wise uncertainties for the groups of the remaining group structures. The group-wise uncertainties thus obtained are compared with those obtained from a full RPCM, i.e. without the approximation. A systematic comparison of group-wise uncertainties based on GWCM's vs. RPCM, for a variety of group structures, will shed light on the validity of this approximation and may suggest which group structure(s) yield a GWCM that could be used in lieu of the RPCM.

  16. Noncontact nonlinear resonant ultrasound spectroscopy to evaluate creep damage in an austenitic stainless steel

    NASA Astrophysics Data System (ADS)

    Ohtani, T.; Kusanagi, Y.; Ishii, Y.

    2013-01-01

    In this paper, we described an evaluating technique of creep damage in an austenitic stainless steel by the combination with an electromagnetic acoustic transducer (EMAT) and the nonlinear resonant ultrasound spectroscopy (NRUS), which was a resonance-based technique exploiting the significant nonlinear behavior of damaged materials. In NRUS, the resonant frequency of an object is studied as a function of the excitation level. As the excitation level increases, the elastic nonlinearity was manifest by a shift in the resonance frequency. The nonlinearity with NRUS showed a peak at 50 % and a minimum at 70 % of the total creep life. This nonlinearity measurement has a potential to assess creep damage advance and predict the creep remaining life of metals.

  17. Evaluation of magnetic resonance safety of veterinary radiofrequency identification devices at 1 T.

    PubMed

    Baker, Martin A; MacDonald, Iain

    2011-01-01

    Implants containing metallic components have the potential to become heated or move within the patient while in the magnetic resonance (MR) environment. Despite containing a ferromagnetic core and having been in use for over 20 years, no information is available on the safety of veterinary radiofrequency identification devices during MR examinations. These devices are the most commonly encountered metallic implants in dogs and cats undergoing MR imaging. Three commercial veterinary microchips were evaluated for safety in the MR environment at 1 T. Parameters tested were translational force, torque, heating, artifact production, and function. Translation and torque were larger than that expected from normal activity under normal gravity. No significant heating was observed. Signal void artifacts may affect diagnosis if they are too close to the area of clinical importance. Microchip function was unaffected by routine clinical MR imaging. Capsule formation around devices is a major factor in counteracting translation and torque. Our findings support that is acceptable for patients to undergo MR imaging with this 1 T system following an interval of 3 months postimplantation to allow capsule growth. Because of the complex interactions involved, these observations may not be translatable to MR scanners of different field strength and/or manufacturer. Further safety testing of these and other radiofrequency identification devices is therefore recommended at different field strengths and equipment specifications.

  18. Evaluation of Parameters for High Efficiency Transformation of Acinetobacter baumannii

    PubMed Central

    Yildirim, Suleyman; Thompson, Mitchell G.; Jacobs, Anna C.; Zurawski, Daniel V.; Kirkup, Benjamin C.

    2016-01-01

    Acinetobacter baumannii is an emerging, nosocomial pathogen that is poorly characterized due to a paucity of genetic tools and methods. While whole genome sequence data from several epidemic and environmental strains have recently become available, the functional characterization of genes is significantly lagging. Efficient transformation is one of the first steps to develop molecular tools that can be used to address these shortcomings. Here we report parameters allowing high efficiency transformation of A. baumannii. Using a multi-factorial experimental design we found that growth phase, voltage, and resistance all significantly contribute to transformation efficiency. The highest efficiency (4.3 × 108 Transformants/μg DNA) was obtained at the stationary growth phase of the bacterium (OD 6.0) using 25 ng of plasmid DNA under 100 Ohms resistance and 1.7 kV/cm voltage. The optimized electroporation parameters reported here provide a useful tool for genetic manipulation of A. baumannii. PMID:26911658

  19. Subsecond magnetic resonance angiography and the evaluation of abnormal arteriovasuclar communications

    NASA Astrophysics Data System (ADS)

    Zachariah, Anish B.; Pereles, F. S.; Kaliney, Ryan; Carr, James C.; Collins, Jeremy D.; Wood, Cecil; Finn, John P.

    2003-05-01

    Magnetic resonance (MR) angiography is becoming widely accepted in the diagnosis of vascular diseases. When used for evaluation of arterial stenoses, aneurysm, thrombosis, or occlusion, MR angiography is a robust and accurate technique. Traditional techniques for contrast-enhanced magnetic resonance angiography (MRA) offer the benefit of high spatial resolution in characterizing vascular malformations, but have lacked the temporal resolution to describe dynamic flow events. The purpose of this project is to demonstrate the potential role of a novel technique, sub-second MRA, in the evaluation of abdominal arteriovenous malformation.

  20. Tabletop magnetic resonance elastography for the measurement of viscoelastic parameters of small tissue samples

    NASA Astrophysics Data System (ADS)

    Ipek-Ugay, Selcan; Drießle, Toni; Ledwig, Michael; Guo, Jing; Hirsch, Sebastian; Sack, Ingolf; Braun, Jürgen

    2015-02-01

    We demonstrate the feasibility of low-cost tabletop MR elastography (MRE) for quantifying the complex shear modulus G∗ of small soft biological tissue samples as provided by pathologists. The MRE system was developed based on a tabletop MRI scanner equipped with a 0.5 T permanent magnet and a tissue sample holder mounted to a loudspeaker. A spin echo sequence was enhanced with motion-encoding gradients of 250 mT/m amplitude synchronized to acoustic vibration frequencies. Shear wave images suitable for elastography were acquired between vibration frequencies of 0.5 and 1 kHz in agarose, ultrasound gel, porcine liver, porcine skeletal muscle, and bovine heart with a spatial resolution of 234 μm pixel edge length. The measured frequency dependence of G∗ agreed well with previous work based on high-field MR systems. The ratio between loss and storage moduli was highest in liver and ultrasound gel, followed by muscle tissue and agarose gel while ultrasound gel and liver showed similarly low storage moduli compared to the other samples. The shear wave to noise ratio is an important imaging criteria for MRE and was about 4.2 times lower for the preliminary setup of the 0.5 T tabletop system compared to a 7 T animal scanner. In the future, the new tabletop MRE system may serve as a low cost device for preclinical research on the correlation of viscoelastic parameters with histopathology of biological samples.

  1. Resolution of the multichannel anomaly in the extraction of S-matrix resonance-pole parameters

    SciTech Connect

    Ceci, Sasa; Stahov, Jugoslav; Svarc, Alfred; Zauner, Branimir; Watson, Shon

    2008-06-01

    Within the framework of a mathematically well-defined coupled-channel T-matrix model we have improved the existing multichannel pole-extraction procedure based on the numerical analytic continuation of the channel propagator, and for the first time we present the full set of pole parameters for already published amplitudes. Standard single-channel pole-extraction method (speed plot) was then applied to those amplitudes and resulting sets of T-matrix poles were inspected. The anomaly has been established that in some partial waves the pole values extracted using the standard single-channel methods differ not only from the values obtained using the analytic continuation method, but also change from one reaction to another. Inspired by this peculiarity, we have developed a new single-channel pole-extraction method based solely on the assumption of the partial wave analyticity. Since the speed plot turns out to be the lowest order term of the proposed method, the anomaly is understood and resolved.

  2. Evaluation parameters for the alkaline fuel cell oxygen electrode

    NASA Technical Reports Server (NTRS)

    Singer, J.; Srinivasan, V.

    1985-01-01

    Studies were made of Pt- and Au-catalyzed porous electrodes, designed for the cathode of the alkaline H2/O2 fuel cell, employing cyclic voltammetry and the floating half-cell method. The purpose was to obtain parameters from the cyclic voltammograms which could predict performance in the fuel cell. It was found that a satisfactory relationship between these two types of measurement could not be established; however, useful observations were made of relative performance of several types of carbon used as supports for noble metal catalysts and of some Au catalysts. The best half-cell performance with H2/O2 in a 35 percent KOH electrolyte at 80 C was given by unsupported fine particle Au on Teflon; this electrode is used in the Orbiter fuel cell.

  3. Evaluating System Parameters on a Dragonfly using Simulation and Visualization

    SciTech Connect

    Bhatele, Abhinav; Jain, Nikhil; Livnat, Yarden; Pascucci, Valerio; Bremer, Peer-Timo

    2015-04-24

    The dragon y topology is becoming a popular choice for build- ing high-radix, low-diameter networks with high-bandwidth links. Even with a powerful network, preliminary experi- ments on Edison at NERSC have shown that for communica- tion heavy applications, job interference and thus presumably job placement remains an important factor. In this paper, we explore the e ects of job placement, job sizes, parallel workloads and network con gurations on network through- put to better understand inter-job interference. We use a simulation tool called Damsel y to model the network be- havior of Edison and study the impact of various system parameters on network throughput. Parallel workloads based on ve representative communication patters are used and the simulation studies on up to 131,072 cores are aided by a new visualization of the dragon y network.

  4. Relativistic theory of nuclear magnetic resonance parameters in a Gaussian basis representation

    SciTech Connect

    Kutzelnigg, Werner; Liu Wenjian

    2009-07-28

    The calculation of NMR parameters from relativistic quantum theory in a Gaussian basis expansion requires some care. While in the absence of a magnetic field the expansion in a kinetically balanced basis converges for the wave function in the mean and for the energy with any desired accuracy, this is not necessarily the case for magnetic properties. The results for the magnetizability or the nuclear magnetic shielding are not even correct in the nonrelativistic limit (nrl) if one expands the original Dirac equation in a kinetically balanced Gaussian basis. This defect disappears if one starts from the unitary transformed Dirac equation as suggested by Kutzelnigg [Phys. Rev. A 67, 032109 (2003)]. However, a new difficulty can arise instead if one applies the transformation in the presence of the magnetic field of a point nucleus. If one decomposes certain contributions, the individual terms may diverge, although their sum is regular. A controlled cancellation may become difficult and numerical instabilities can arise. Various ways exist to avoid these singularities and at the same time get the correct nrl. There are essentially three approaches intermediate between the transformed and the untransformed formulation, namely, the bispinor decomposition, the decomposition of the lower component, and the hybrid unitary transformation partially at operator and partially at matrix level. All three possibilities were first considered by Xiao et al. [J. Chem. Phys. 126, 214101 (2007)] in a different context and in a different nomenclature. Their analysis and classification in a more general context are given here for the first time. Use of an extended balanced basis has no advantages and has other drawbacks and is not competitive, while the use of a restricted magnetic balance basis can be justified.

  5. Optimization of Regularization Parameters in Compressed Sensing of Magnetic Resonance Angiography: Can Statistical Image Metrics Mimic Radiologists' Perception?

    PubMed

    Akasaka, Thai; Fujimoto, Koji; Yamamoto, Takayuki; Okada, Tomohisa; Fushumi, Yasutaka; Yamamoto, Akira; Tanaka, Toshiyuki; Togashi, Kaori

    2016-01-01

    In Compressed Sensing (CS) of MRI, optimization of the regularization parameters is not a trivial task. We aimed to establish a method that could determine the optimal weights for regularization parameters in CS of time-of-flight MR angiography (TOF-MRA) by comparing various image metrics with radiologists' visual evaluation. TOF-MRA of a healthy volunteer was scanned using a 3T-MR system. Images were reconstructed by CS from retrospectively under-sampled data by varying the weights for the L1 norm of wavelet coefficients and that of total variation. The reconstructed images were evaluated both quantitatively by statistical image metrics including structural similarity (SSIM), scale invariant feature transform (SIFT) and contrast-to-noise ratio (CNR), and qualitatively by radiologists' scoring. The results of quantitative metrics and qualitative scorings were compared. SSIM and SIFT in conjunction with brain masks and CNR of artery-to-parenchyma correlated very well with radiologists' visual evaluation. By carefully selecting a region to measure, we have shown that statistical image metrics can reflect radiologists' visual evaluation, thus enabling an appropriate optimization of regularization parameters for CS. PMID:26744843

  6. Optimization of Regularization Parameters in Compressed Sensing of Magnetic Resonance Angiography: Can Statistical Image Metrics Mimic Radiologists' Perception?

    PubMed Central

    Akasaka, Thai; Fujimoto, Koji; Yamamoto, Takayuki; Okada, Tomohisa; Fushumi, Yasutaka; Yamamoto, Akira; Tanaka, Toshiyuki; Togashi, Kaori

    2016-01-01

    In Compressed Sensing (CS) of MRI, optimization of the regularization parameters is not a trivial task. We aimed to establish a method that could determine the optimal weights for regularization parameters in CS of time-of-flight MR angiography (TOF-MRA) by comparing various image metrics with radiologists’ visual evaluation. TOF-MRA of a healthy volunteer was scanned using a 3T-MR system. Images were reconstructed by CS from retrospectively under-sampled data by varying the weights for the L1 norm of wavelet coefficients and that of total variation. The reconstructed images were evaluated both quantitatively by statistical image metrics including structural similarity (SSIM), scale invariant feature transform (SIFT) and contrast-to-noise ratio (CNR), and qualitatively by radiologists’ scoring. The results of quantitative metrics and qualitative scorings were compared. SSIM and SIFT in conjunction with brain masks and CNR of artery-to-parenchyma correlated very well with radiologists’ visual evaluation. By carefully selecting a region to measure, we have shown that statistical image metrics can reflect radiologists’ visual evaluation, thus enabling an appropriate optimization of regularization parameters for CS. PMID:26744843

  7. Doppler echocardiographic parameters of evaluation of left ventricular systolic function.

    PubMed

    Drăgulescu, S I; Roşu, D; Abazid, J; Ionac, A

    1993-01-01

    The authors suggest a new method using Doppler echocardiography for the evaluation of cardiac performance. Doppler echocardiography permits the calculation of left ventricular (LV) ejection force (according to Newton's second law of motion). The ejection force was calculated in 36 patients with heart failure subgrouped into 3 groups based on ejection fraction (EF) (> 60%; 41-60%; < 40%) compared to 11 normal subjects. The LV ejection force showed a good linear correlation with LV ejection fraction (r = 0.86). Data of the study suggest that the LV ejection force is a valuable and accurate index for the assessment of cardiac performance, especially in early stages of disease.

  8. Stokes parameters of resonance lines scattered by a moving, magnetic medium. Theory of the two-level atom

    NASA Astrophysics Data System (ADS)

    Raouafi, N.-E.

    2002-05-01

    The aim of the present work is to present theoretical results on the Stokes parameters of a resonance spectral line, scattered by moving atoms (or ions) in the presence of a local magnetic field. We assume that the scattered line is sensitive to the Hanle effect due to the magnetic field and also to Doppler redistribution due to the atomic motions. The present theory is developed for a two-level atom, in the framework of the density matrix formalism Blum (1981). Analogous results given in Sahal-Bréchot et al. (1986) for the magnetic-field effect alone, and in Sahal-Bréchot et al. (\\cite{Sahal98}) for the velocity-field effect alone, can be obtained from our theory by cancelling in the equations, respectively, the velocity field or the magnetic field. The results of our theory are general and can be used for astrophysical studies concerning the Hanle effect and the Doppler redistribution effect on the linear polarization parameters of the scattered radiation. They can be used particularly to interpret linear polarization of coronal spectral lines to get a complete determination of vectorial quantities such as the coronal magnetic field and the solar wind velocity field vectors. As an application, the atomic velocity field distribution is supposed to be Maxwellian with a drift velocity field vector. This latter describes the macroscopic motion of the scattering atoms. In the solar corona, it can be assimilated into the solar wind velocity field vector.

  9. Quantifying Uranium Isotope Ratios Using Resonance Ionization Mass Spectrometry: The Influence of Laser Parameters on Relative Ionization Probability

    SciTech Connect

    Isselhardt, Brett H.

    2011-09-01

    Resonance Ionization Mass Spectrometry (RIMS) has been developed as a method to measure relative uranium isotope abundances. In this approach, RIMS is used as an element-selective ionization process to provide a distinction between uranium atoms and potential isobars without the aid of chemical purification and separation. We explore the laser parameters critical to the ionization process and their effects on the measured isotope ratio. Specifically, the use of broad bandwidth lasers with automated feedback control of wavelength was applied to the measurement of 235U/238U ratios to decrease laser-induced isotopic fractionation. By broadening the bandwidth of the first laser in a 3-color, 3-photon ionization process from a bandwidth of 1.8 GHz to about 10 GHz, the variation in sequential relative isotope abundance measurements decreased from >10% to less than 0.5%. This procedure was demonstrated for the direct interrogation of uranium oxide targets with essentially no sample preparation. A rate equation model for predicting the relative ionization probability has been developed to study the effect of variation in laser parameters on the measured isotope ratio. This work demonstrates that RIMS can be used for the robust measurement of uranium isotope ratios.

  10. Evaluation of brain edema using magnetic resonance proton relaxation times

    SciTech Connect

    Fu, Y.; Tanaka, K.; Nishimura, S. )

    1990-01-01

    Experimental and clinical studies on the evaluation of water content in cases of brain edema were performed in vivo, using MR proton relaxation times (longitudinal relaxation time, T1; transverse relaxation time, T2). Brain edema was produced in the white matter of cats by the direct infusion method. The correlations between proton relaxation times obtained from MR images and the water content of white matter were studied both in autoserum-infused cats and in saline-infused cats. The correlations between T1 as well as T2 and the water content in human vasogenic brain edema were also examined and compared with the data obtained from the serum group. T1 and T2 showed good correlations with the water content of white matter not only in the experimental animals but also in the clinical cases. The quality of the edema fluid did not influence relaxation time and T1 seemed to represent almost solely the water content of the tissue. T2, however, was affected by the nature of existence of water and was more sensitive than T1 in detecting extravasated edema fluid. It seems feasible therefore to evaluate the water content of brain edema on the basis of T1 values.

  11. Key Parameters Evaluation for Hip Prosthesis with Finite Element Analysis

    NASA Astrophysics Data System (ADS)

    Guo, Hongqiang; Li, Dichen; Lian, Qin; Li, Xiang; Jin, Zhongmin

    2007-09-01

    Stem length and cross section are two key parameters that influence the stability and longevity of metallic hip prosthesis in the total hip arthroplasty (THA). In order to assess their influence to the stress and fatigue behavior of hip prosthesis, a series model of hip prosthesis with round-shaped or drum-shaped cross section, and with different stem lengths were created. These models were analyzed under both static and dynamic loading conditions with finite element analysis, and dynamic loading represents normal walking was used in the dynamic analysis. The stress on the metallic stem, cement, and adjacent bone were got, micromotion on the cement-metal interface were got too. Safety factors for fatigue life of the hip prothesis were calculated based on data obtained from dynamic analysis. Static analysis shows that drum-shaped cross section can decrease the displacement of the stem, that stress on drum-shaped stem focus on the corner of the femoral neck and the distal part of hip prosthesis, whereas the stress on the round-shaped stem distributes evenly over most part of the stem, and maximum stress on stem prosthesis fluctuates with stem length bottoming out at stem length range from 80 mm to 110 mm, that drum-shaped stems with drum height 8 mm generate more stress at the distal part of stem than drum-shaped stems with drum height 10 mm and round stems do. Dynamic and fatigue analysis shows that drum-shaped stem with drum height 10 mm and stem length 90 mm has the greatest safety factor therefore long fatigue life.

  12. Neurocysticercosis: evaluation with advanced magnetic resonance techniques and atypical forms.

    PubMed

    do Amaral, Lázaro Luís Faria; Ferreira, Rafael Martins; da Rocha, Antônio José; Ferreira, Nelson Paes Diniz Fortes

    2005-04-01

    Neurocysticercosis (NCC) is the most common helminthic infection of the central nervous system, but its diagnosis remains difficult. The purpose of this article is to perform a critical analysis of the literature and show our experience in the evaluation of NCC. We discuss the advanced MR technique applications such as diffusion and perfusion-weighted imaging, spectroscopy, cisternography with FLAIR, and supplemental O2 and 3D-CISS. The typical manifestations of NCC are described; emphasis is given to the unusual presentations. The atypical forms of neurocysticercosis were divided into: intraventricular, subarachnoid, spinal, orbital, and intraparenchymatous. Special attention was also given to reactivation of previously calcified lesions and neurocysticercosis associated with mesial temporal sclerosis.

  13. The Evaluation of Empirical Resonance Energies as Reaction Enthalpies with Particular Reference to Benzene.

    ERIC Educational Resources Information Center

    George, Philip; And Others

    1984-01-01

    Discusses the nature of experimental resonance energy, explaining how its magnitude depends upon choice of reference molecules from which bond energies are derived. Also explains how it can be evaluated more simply, without recourse to bond energies, as enthalpy change for a reaction predetermined by choice of reference molecules. (JN)

  14. Clinical parameters for evaluating biological response modifier therapy.

    PubMed

    Hamblin, T J

    1989-01-01

    Evaluating response in cancer is a well established practice, depending on the recognition of complete response, partial response, stable disease and progressive disease. For chemotherapeutic drugs, only those patients achieving a complete response experience an increase in survival. Partial response merely indicates that the drug has some activity in that disease. What the patient wants is not active drugs but prolonged survival with good quality of life. It is well recognised that tumours may remain dormant for many years, and that even those patients with complete responses to chemotherapy usually have minimal residual disease. It is assumed that such minimal disease is controlled and held in check by a biological process. The principal aim of biological response modifiers is to enhance this effect so as to control an even larger tumour load. It therefore follows that removal of all tumour is not the only benefit, and that stable disease and even slower progression might translate to longer survival. Survival curves are the acid test and we should expect longer survival even for those patients failing to achieve complete response if we are to establish that life imprisonment is as effective in cancer treatment as capital punishment.

  15. [Magnetic resonance in the evaluation of Mullerian duct anomalies].

    PubMed

    Fischetti, S G; Politi, G; Lomeo, E; Garozzo, G

    1995-01-01

    Müllerian duct alterations in development or fusion in the embryo cause congenital uterine anomalies which may be responsible for decreased fertility or problems in carrying out a normal pregnancy. In this study, the MR findings in uterine agenesis (1 case), unicornuate (2 cases), didelphys (3 cases), bicornuate (3 cases), arcuate (6 cases) and septate uterus (8 cases) are described, together with the optimal section planes for their demonstration. The examinations were performed with an 0.5-T superconductive magnet, the spin-echo technique and mostly T2-weighted sequences. The anomalies were grouped according to Buttram and Gibbons classification, which is the most used in clinics. In particular, the bicornuate uterus was distinguished from the septate uterus, the latter associated with the highest spontaneous abortion rates, on the basis of external fundal outline appearance. In such anomalies, the muscular or fibrotic nature of any intracavitary septum was assessed based on septal thickness more than on signal intensity at this level. MR diagnostic accuracy in 23 patients with Müllerian anomalies, compared with surgical, hysteroscopic, laparotomic and laparoscopic findings, was 100%. Nevertheless, if Müllerian duct anomalies responsible for gynecologic-obstetric problems are known or suspected, MRI should always be used, on the basis of a close gynecologist-radiologist collaboration, for classification agreement and the evaluation of any intracavitary septum morpho-biometric appearance and possibly nature, to discuss treatment options.

  16. [Optimal imaging parameters and the advantage of cerebrospinal fluid flow image using time-spatial labeling inversion pulse at 3 tesla magnetic resonance imaging: comparison of image quality for 1.5 tesla magnetic resonance imaging].

    PubMed

    Ozasa, Masaya; Yahata, Seiji; Yoshida, Ayako; Takeyama, Mamoru; Eshima, Mitsuhiro; Shinohara, Maiko; Yamamoto, Takao; Abe, Kayoko

    2014-12-01

    Cerebrospinal fluid (CSF) imaging by time-spatial labeling inversion pulse (Time-SLIP) technique is labeled by CSF with a selective inversion recovery (IR) pulse as internal tracer, thus making it possible to visualize CSF dynamics non-invasively. The purpose of this study was to clarify labeled CSF signals during various black blood time to inversion (BBTI) values at 3 tesla (T) and 1.5 T magnetic resonance imaging (MRI) and to determine appropriate CSF imaging parameters at 3 T MRI in 10 healthy volunteers. To calculate optimal BBTI values, ROIs were set in untagged cerebral parenchyma and CSF on the image of the CSF flow from the aqueduct to the fourth ventricle in 1.5 T and 3 T MRI. Visual evaluation of CSF flow also was assessed with changes of matrix and echo time (TE) at 3 T MRI. The mean BBTI value at null point of untagged CSF in 3 T MRI was longer than that of 1.5 T. The MR conditions of the highest visual evaluation were FOV, 14 cm×14 cm; Matrix, 192×192; and TE, 117 ms. CSF imaging using Time-SLIP at 3 T MRI is expected visualization of CSF flow and clarification of CSF dynamics in more detail by setting the optimal conditions because 3 T MRI has the advantage of high contrast and high signal-to-noise ratio.

  17. White LED compared with other light sources: age-dependent photobiological effects and parameters for evaluation.

    PubMed

    Rebec, Katja Malovrh; Klanjšek-Gunde, Marta; Bizjak, Grega; Kobav, Matej B

    2015-01-01

    Ergonomic science at work and living places should appraise human factors concerning the photobiological effects of lighting. Thorough knowledge on this subject has been gained in the past; however, few attempts have been made to propose suitable evaluation parameters. The blue light hazard and its influence on melatonin secretion in age-dependent observers is considered in this paper and parameters for its evaluation are proposed. New parameters were applied to analyse the effects of white light-emitting diode (LED) light sources and to compare them with the currently applied light sources. The photobiological effects of light sources with the same illuminance but different spectral power distribution were determined for healthy 4-76-year-old observers. The suitability of new parameters is discussed. Correlated colour temperature, the only parameter currently used to assess photobiological effects, is evaluated and compared to new parameters. PMID:26647954

  18. Nondestructive evaluation of explosively welded clad rods by resonance acoustic spectroscopy.

    PubMed

    Fan, Y; Tysoe, B; Sim, J; Mirkhani, K; Sinclair, A N; Honarvar, F; Sildva, Harry; Szecket, Alexander; Hardwick, Roy

    2003-07-01

    A resonance acoustic spectroscopy technique is assessed for nondestructive evaluation of explosively welded clad rods. Each rod is modeled as a two-layered cylinder with a spring-mass system to represent a thin interfacial layer containing the weld. A range of interfacial profiles is generated in a set of experimental samples by varying the speed of the explosion that drives the copper cladding into the aluminum core. Excellent agreement is achieved between measured and calculated values of the resonant frequencies of the system, through appropriate adjustment of the interfacial mass and spring constants used in the wave scattering calculations. Destructive analysis of the interface in the experimental specimens confirms that key features of the interfacial profile may be inferred from resonance acoustic spectroscopy analysis applied to ultrasonic measurements.

  19. Resonance wood [Picea abies (L.) Karst.]--evaluation and prediction of violin makers' quality-grading.

    PubMed

    Buksnowitz, Christoph; Teischinger, Alfred; Müller, Ulrich; Pahler, Andreas; Evans, Robert

    2007-04-01

    The definition of quality in the field of resonance wood for musical instrument making has attracted considerable interest over decades but has remained incomplete. The current work compares the traditional knowledge and practical experience of violin makers with a material-science approach to objectively characterize the properties of resonance wood. Norway spruce [Picea abies (L.) Karst.] has earned a very high reputation for the construction of resonance tops of stringed instruments and resonance boards of keyboard instruments, and was therefore chosen as the focus of the investigation. The samples were obtained from numerous renowned resonance wood regions in the European Alps and cover the whole range of available qualities. A set of acoustical, anatomical, mechanical and optical material properties was measured on each sample. These measurements were compared with subjective quality grading by violin makers, who estimated the acoustical, optical and overall suitability for violin making. Multiple linear regression models were applied to evaluate the predictability of the subjective grading using the measured material characteristics as predictors. The results show that luthiers are able to estimate wood quality related to visible features, but predictions of mechanical and acoustical properties proved to be very poor. PMID:17471750

  20. Resonance wood [Picea abies (L.) Karst.]--evaluation and prediction of violin makers' quality-grading.

    PubMed

    Buksnowitz, Christoph; Teischinger, Alfred; Müller, Ulrich; Pahler, Andreas; Evans, Robert

    2007-04-01

    The definition of quality in the field of resonance wood for musical instrument making has attracted considerable interest over decades but has remained incomplete. The current work compares the traditional knowledge and practical experience of violin makers with a material-science approach to objectively characterize the properties of resonance wood. Norway spruce [Picea abies (L.) Karst.] has earned a very high reputation for the construction of resonance tops of stringed instruments and resonance boards of keyboard instruments, and was therefore chosen as the focus of the investigation. The samples were obtained from numerous renowned resonance wood regions in the European Alps and cover the whole range of available qualities. A set of acoustical, anatomical, mechanical and optical material properties was measured on each sample. These measurements were compared with subjective quality grading by violin makers, who estimated the acoustical, optical and overall suitability for violin making. Multiple linear regression models were applied to evaluate the predictability of the subjective grading using the measured material characteristics as predictors. The results show that luthiers are able to estimate wood quality related to visible features, but predictions of mechanical and acoustical properties proved to be very poor.

  1. Modeling of Resonant Ultrasound Spectroscopy Based Nondestructive Evaluation Using the "XYZ-Algorithm"

    SciTech Connect

    Ahmed, Salahuddin; Bond, Leonard J.

    2007-05-03

    Resonant ultrasound spectroscopy (RUS) is employed as a nondestructive evaluation (NDE) tool in a number of metal/ceramic forming industries [1]. The presence of volumetric defects in an otherwise flaw-free object affects the resonance characteristics of the object. The changes in resonance behavior depend on the number, locations, volume, and material properties of the defects. Since the normal modes of an object depend on its geometry and the position-dependent material properties, namely the density and the complex elastic stiffness tensor, by accurate measurement of a specimen’s resonance frequencies and amplitudes, one can detect and characterize flaws embedded within it. A correct forward mathematical model to predict resonance characteristics is vital to the required analyses. In this paper, we present several computational results depicting the influence of the presence of embedded flaws/defects in a test specimen having simple geometrical shape. The mathematical model is based on the computationally efficient “XYZ Algorithm” of Visscher et al.

  2. Infrared and far-infrared laser magnetic resonance spectroscopy of the GeH radical - Determination of ground state parameters

    NASA Technical Reports Server (NTRS)

    Brown, J. M.; Evenson, K. M.; Sears, T. J.

    1985-01-01

    The GeH radical has been detected in its ground 2 Pi state in the gas phase reaction of fluorine atoms with GeH4 by laser magnetic resonance techniques. Rotational transitions within both 2 Pi 1/2 and 2 Pi 3/2 manifolds have been observed at far-infrared wavelengths and rotational transitions between the two fine structure components have been detected at infrared wavelengths (10 microns). Signals have been observed for all five naturally occurring isotopes of germanium. Nuclear hyperfine structure for H-1 and Ge-73 has also been observed. The data for the dominant isotope (/Ge-74/H) have been fitted to within experimental error by an effective Hamiltonian to give a set of molecular parameters for the X 2 Pi state which is very nearly complete. In addition, the dipole moment of GeH in its ground state has been estimated from the relative intensities of electric and magnetic dipole transitions in the 10 micron spectrum to be 1.24(+ or - 0.10) D.

  3. Parameters of nasal airway anatomy on magnetic resonance imaging correlate poorly with subjective symptoms of nasal patency.

    PubMed

    Saunders, M W; Jones, N S; Kabala, J E

    1999-09-01

    Forty-four patients undergoing magnetic resonance imaging (MRI) head scans for non-nasal disease were asked to complete a questionnaire immediately after the scan. Subjective patency was scored for each nasal airway, patients were also asked about other nasal symptoms, hay fever, upper respiratory tract infections, medication and any history of nasal surgery or trauma. The following measurements from MRI scans were made: the cross-sectional area of the nasal airway at the anterior end of the middle turbinate, the horizontal width of the inferior turbinate and maximum septal mucosal thickness. In addition the presence of any septal deviation and the thickness or the mucosa of the paranasal sinuses was assessed. Correlation between subjective airway patency and the anatomical parameters studied was generally very weak. However, patients with sinus mucosal thickening on MRI scanning had significantly lower subjective patency scores (left P = 0.003, right P = 0.029) for both nasal airways. Assessment of the nasal airway on MRI correlates poorly with symptoms of nasal obstruction. However, patients with sinus mucosal thickening (> 5 mm) had significantly more symptoms of nasal obstruction on both sides.

  4. TI-205 nuclear magnetic resonance determination of the thermodynamic parameters for the binding of monovalent cations to gramicidins A and C.

    PubMed Central

    Hinton, J F; Fernandez, J Q; Shungu, D C; Whaley, W L; Koeppe, R E; Millett, F S

    1988-01-01

    Thermodynamic parameters for the binding of the monovalent cations, Li+, Na+, K+, Rb+, Cs+, NH4+, TI+, and Ag+, to gramicidin A and for the binding of TI+ to gramicidin C, incorporated into lysophosphatidylcholine, have been determined using a combination of TI-205 nuclear magnetic resonance spectroscopy and competition binding. The thermodynamic parameters, enthalpy and entropy, are discussed in terms of a process involving the transfer of cations from an aqueous to amide environment. PMID:2462930

  5. Criteria for first- and second-order vibrational resonances and correct evaluation of the Darling-Dennison resonance coefficients using the canonical Van Vleck perturbation theory

    SciTech Connect

    Krasnoshchekov, Sergey V.; Isayeva, Elena V.; Stepanov, Nikolay F.

    2014-12-21

    The second-order vibrational Hamiltonian of a semi-rigid polyatomic molecule when resonances are present can be reduced to a quasi-diagonal form using second-order vibrational perturbation theory. Obtaining exact vibrational energy levels requires subsequent numerical diagonalization of the Hamiltonian matrix including the first- and second-order resonance coupling coefficients. While the first-order Fermi resonance constants can be easily calculated, the evaluation of the second-order Darling-Dennison constants requires more complicated algebra for seven individual cases with different numbers of creation-annihilation vibrational quanta. The difficulty in precise evaluation of the Darling-Dennison coefficients is associated with the previously unrecognized interference with simultaneously present Fermi resonances that affect the form of the canonically transformed Hamiltonian. For the first time, we have presented the correct form of the general expression for the evaluation of the Darling-Dennison constants that accounts for the underlying effect of Fermi resonances. The physically meaningful criteria for selecting both Fermi and Darling-Dennison resonances are discussed and illustrated using numerical examples.

  6. BUILDING MODEL ANALYSIS APPLICATIONS WITH THE JOINT UNIVERSAL PARAMETER IDENTIFICATION AND EVALUATION OF RELIABILITY (JUPITER) API

    EPA Science Inventory

    The open-source, public domain JUPITER (Joint Universal Parameter IdenTification and Evaluation of Reliability) API (Application Programming Interface) provides conventions and Fortran-90 modules to develop applications (computer programs) for analyzing process models. The input ...

  7. A COMPUTATIONAL FRAMEWORK FOR EVALUATION OF NPS MANAGEMENT SCENARIOS: ROLE OF PARAMETER UNCERTAINTY

    EPA Science Inventory

    Utility of complex distributed-parameter watershed models for evaluation of the effectiveness of non-point source sediment and nutrient abatement scenarios such as Best Management Practices (BMPs) often follows the traditional {calibrate ---> validate ---> predict} procedure. Des...

  8. Update on Magnetic Resonance Imaging and Ultrasound Evaluation of Crohn's Disease.

    PubMed

    Deepak, Parakkal; Kolbe, Amy B; Fidler, Jeff L; Fletcher, Joel G; Knudsen, John M; Bruining, David H

    2016-04-01

    Magnetic resonance enterography (MRE) and abdominal ultrasound are integral parts of multimodality assessments for patients with inflammatory bowel disease. Applications include assessing Crohn's disease (CD) extent and severity, differentiating CD from ulcerative colitis, detecting CD complications, evaluating response to therapy, and demonstrating postoperative recurrence. Magnetic resonance imaging protocols are being developed that may reduce or eliminate the need for intravenous contrast agents and better differentiate inflammatory from fibrotic strictures. MRE scoring systems have been created to objectively quantify disease activity and response to therapy. By utilizing advanced sonographic imaging techniques, including ultrasound contrast and Doppler assessments, the role of abdominal ultrasonography in the evaluation and management of CD continues to expand. Abdominal ultrasound may function as a low-cost, point-of care assessment tool, especially in CD restricted to the terminal ileum and ileocolic anastomosis. PMID:27231453

  9. Update on Magnetic Resonance Imaging and Ultrasound Evaluation of Crohn’s Disease

    PubMed Central

    Deepak, Parakkal; Kolbe, Amy B.; Fidler, Jeff L.; Fletcher, Joel G.; Knudsen, John M.

    2016-01-01

    Magnetic resonance enterography (MRE) and abdominal ultrasound are integral parts of multimodality assessments for patients with inflammatory bowel disease. Applications include assessing Crohn’s disease (CD) extent and severity, differentiating CD from ulcerative colitis, detecting CD complications, evaluating response to therapy, and demonstrating postoperative recurrence. Magnetic resonance imaging protocols are being developed that may reduce or eliminate the need for intravenous contrast agents and better differentiate inflammatory from fibrotic strictures. MRE scoring systems have been created to objectively quantify disease activity and response to therapy. By utilizing advanced sonographic imaging techniques, including ultrasound contrast and Doppler assessments, the role of abdominal ultrasonography in the evaluation and management of CD continues to expand. Abdominal ultrasound may function as a low-cost, point-of care assessment tool, especially in CD restricted to the terminal ileum and ileocolic anastomosis. PMID:27231453

  10. Improved Estimation of Cardiac Function Parameters Using a Combination of Independent Automated Segmentation Results in Cardiovascular Magnetic Resonance Imaging.

    PubMed

    Lebenberg, Jessica; Lalande, Alain; Clarysse, Patrick; Buvat, Irene; Casta, Christopher; Cochet, Alexandre; Constantinidès, Constantin; Cousty, Jean; de Cesare, Alain; Jehan-Besson, Stephanie; Lefort, Muriel; Najman, Laurent; Roullot, Elodie; Sarry, Laurent; Tilmant, Christophe; Frouin, Frederique; Garreau, Mireille

    2015-01-01

    This work aimed at combining different segmentation approaches to produce a robust and accurate segmentation result. Three to five segmentation results of the left ventricle were combined using the STAPLE algorithm and the reliability of the resulting segmentation was evaluated in comparison with the result of each individual segmentation method. This comparison was performed using a supervised approach based on a reference method. Then, we used an unsupervised statistical evaluation, the extended Regression Without Truth (eRWT) that ranks different methods according to their accuracy in estimating a specific biomarker in a population. The segmentation accuracy was evaluated by estimating six cardiac function parameters resulting from the left ventricle contour delineation using a public cardiac cine MRI database. Eight different segmentation methods, including three expert delineations and five automated methods, were considered, and sixteen combinations of the automated methods using STAPLE were investigated. The supervised and unsupervised evaluations demonstrated that in most cases, STAPLE results provided better estimates than individual automated segmentation methods. Overall, combining different automated segmentation methods improved the reliability of the segmentation result compared to that obtained using an individual method and could achieve the accuracy of an expert. PMID:26287691

  11. Improved Estimation of Cardiac Function Parameters Using a Combination of Independent Automated Segmentation Results in Cardiovascular Magnetic Resonance Imaging

    PubMed Central

    Lebenberg, Jessica; Lalande, Alain; Clarysse, Patrick; Buvat, Irene; Casta, Christopher; Cochet, Alexandre; Constantinidès, Constantin; Cousty, Jean; de Cesare, Alain; Jehan-Besson, Stephanie; Lefort, Muriel; Najman, Laurent; Roullot, Elodie; Sarry, Laurent; Tilmant, Christophe

    2015-01-01

    This work aimed at combining different segmentation approaches to produce a robust and accurate segmentation result. Three to five segmentation results of the left ventricle were combined using the STAPLE algorithm and the reliability of the resulting segmentation was evaluated in comparison with the result of each individual segmentation method. This comparison was performed using a supervised approach based on a reference method. Then, we used an unsupervised statistical evaluation, the extended Regression Without Truth (eRWT) that ranks different methods according to their accuracy in estimating a specific biomarker in a population. The segmentation accuracy was evaluated by estimating six cardiac function parameters resulting from the left ventricle contour delineation using a public cardiac cine MRI database. Eight different segmentation methods, including three expert delineations and five automated methods, were considered, and sixteen combinations of the automated methods using STAPLE were investigated. The supervised and unsupervised evaluations demonstrated that in most cases, STAPLE results provided better estimates than individual automated segmentation methods. Overall, combining different automated segmentation methods improved the reliability of the segmentation result compared to that obtained using an individual method and could achieve the accuracy of an expert. PMID:26287691

  12. Magnetic resonance cholangiographic evaluation of intrahepatic and extrahepatic bile duct variations

    PubMed Central

    Sureka, Binit; Bansal, Kalpana; Patidar, Yashwant; Arora, Ankur

    2016-01-01

    Biliary anatomy and its common and uncommon variations are of considerable clinical significance when performing living donor transplantation, radiological interventions in hepatobiliary system, laparoscopic cholecystectomy, and liver resection (hepatectomy, segmentectomy). Because of increasing trend found in the number of liver transplant surgeries being performed, magnetic resonance cholangiopancreatography (MRCP) has become the modality of choice for noninvasive evaluation of abnormalities of the biliary tract. The purpose of this study is to describe the anatomic variations of the intrahepatic and extrahepatic biliary tree. PMID:27081220

  13. Application of Advanced Magnetic Resonance Imaging Techniques in Evaluation of the Lower Extremity

    PubMed Central

    Braun, Hillary J.; Dragoo, Jason L.; Hargreaves, Brian A.; Levenston, Marc E.; Gold, Garry E.

    2012-01-01

    Synopsis This article reviews current magnetic resonance imaging techniques for imaging the lower extremity, focusing on imaging of the knee, ankle, and hip joints. Recent advancements in MRI include imaging at 7 Tesla, using multiple receiver channels, T2* imaging, and metal suppression techniques, allowing more detailed visualization of complex anatomy, evaluation of morphological changes within articular cartilage, and imaging around orthopedic hardware. PMID:23622097

  14. Magnetic resonance imaging in the evaluation of sports injuries of the foot and ankle: a pictorial essay.

    PubMed

    Riley, Geoffrey M

    2007-01-01

    Magnetic resonance imaging is playing an increasingly important role in evaluation of the injured athlete's foot and ankle. Magnetic resonance imaging allows accurate detection of bony abnormalities, such as stress fractures, and soft-tissue abnormalities, including ligament tears, tendon tears, and tendinopathy. The interpreter of magnetic resonance images should systematically review the images, noting normal structures and accounting for changes in soft-tissue and bony signal. PMID:17218626

  15. Dose-Volume Histogram Parameters and Late Side Effects in Magnetic Resonance Image-Guided Adaptive Cervical Cancer Brachytherapy

    SciTech Connect

    Georg, Petra; Lang, Stefan; Dimopoulos, Johannes C.A.; Doerr, Wolfgang; Sturdza, Alina E.; Berger, Daniel; Georg, Dietmar; Kirisits, Christian; Poetter, Richard

    2011-02-01

    Purpose: To evaluate the predictive value of dose-volume histogram (DVH) parameters for late side effects of the rectum, sigmoid colon, and bladder in image-guided brachytherapy for cervix cancer patients. Methods and Materials: A total of 141 patients received external-beam radiotherapy and image-guided brachytherapy with or without chemotherapy. The DVH parameters for the most exposed 2, 1, and 0.1 cm{sup 3} (D{sub 2cc}, D{sub 1cc}, and D{sub 0.1cc}) of the rectum, sigmoid, and bladder, as well as International Commission on Radiation Units and Measurements point doses (D{sub ICRU}) were computed. Total doses were converted to equivalent doses in 2 Gy by applying the linear-quadratic model ({alpha}/{beta} = 3 Gy). Late side effects were prospectively assessed using the Late Effects in Normal Tissues-Subjective, Objective, Management and Analytic score. The following patient groups were defined: Group 1: no side effects (Grade 0); Group 2: side effects (Grade 1-4); Group 3: minor side effects (Grade 0-1); and Group 4: major side effects (Grade 2-4). Results: The median follow-up was 51 months. The overall 5-year actuarial side effect rates were 12% for rectum, 3% for sigmoid, and 23% for bladder. The mean total D{sub 2cc} were 65 {+-} 12 Gy for rectum, 62 {+-} 12 Gy for sigmoid, and 95 {+-} 22 Gy for bladder. For rectum, statistically significant differences were observed between Groups 1 and 2 in all DVH parameters and D{sub ICRU}. Between Groups 3 and 4, no difference was observed for D{sub 0.1cc.} For sigmoid, significant differences were observed for D{sub 2cc} and D{sub 1cc}, but not for D{sub 0.1cc} in all groups. For bladder, significant differences were observed for all DVH parameters only comparing Groups 3 and 4. No differences were observed for D{sub ICRU}. Conclusions: The parameters D{sub 2cc} and D{sub 1cc} have a good predictive value for rectal toxicity. For sigmoid, no prediction could be postulated because of limited data. In bladder, DVH

  16. Acute Cardiac Impairment Associated With Concurrent Chemoradiotherapy for Esophageal Cancer: Magnetic Resonance Evaluation

    SciTech Connect

    Hatakenaka, Masamitsu; Yonezawa, Masato; Nonoshita, Takeshi; Nakamura, Katsumasa; Yabuuchi, Hidetake; Shioyama, Yoshiyuki; Nagao, Michinobu; Matsuo, Yoshio; Kamitani, Takeshi; Higo, Taiki; Nishikawa, Kei; Setoguchi, Taro; Honda, Hiroshi

    2012-05-01

    Purpose: To evaluate acute cardiac effects of concurrent chemoradiotherapy (CCRT) for esophageal cancer. Methods and Materials: This prospective study was approved by the institutional review board, and written informed consent was obtained from all participants. The left ventricular function (LVF) of 31 patients with esophageal cancer who received cisplatin and 5-fluorouracil-based CCRT was evaluated using cardiac cine magnetic resonance imaging. The patients were classified into two groups according to mean LV dose. The parameters related to LVF were compared between before and during (40 Gy) or between before and after CCRT using a Wilcoxon matched-pairs single rank test, and parameter ratios (during/before CCRT, after/before CCRT) were also compared between the groups with a t test. Data were expressed as mean {+-} SE. Results: In the low LV-dose group (n = 10; mean LV dose <0.6 Gy), LV ejection fraction decreased significantly (before vs. during vs. after CCRT; 62.7% {+-} 2.98% vs. 59.8% {+-} 2.56% vs. 60.6% {+-} 3.89%; p < 0.05). In the high LV-dose group (n = 21; mean LV dose of 3.6-41.2 Gy), LV end-diastolic volume index (before vs. after CCRT; 69.1 {+-} 2.93 vs. 57.0 {+-} 3.23 mL/m{sup 2}), LV stroke volume index (38.6 {+-} 1.56 vs. 29.9 {+-} 1.60 mL/m{sup 2}), and LV ejection fraction (56.9% {+-} 1.79% vs. 52.8% {+-} 1.15%) decreased significantly (p < 0.05) after CCRT. Heart rate increased significantly (before vs. during vs. after CCRT; 66.8 {+-} 3.05 vs. 72.4 {+-} 4.04 vs. 85.4 {+-} 3.75 beats per minute, p < 0.01). Left ventricle wall motion decreased significantly (p < 0.05) in segments 8 (before vs. during vs. after CCRT; 6.64 {+-} 0.54 vs. 4.78 {+-} 0.43 vs. 4.79 {+-} 0.50 mm), 9 (6.88 {+-} 0.45 vs. 5.04 {+-} 0.38 vs. 5.27 {+-} 0.47 mm), and 10 (9.22 {+-} 0.48 vs. 8.08 {+-} 0.34 vs. 8.19 {+-} 0.56 mm). The parameter ratios of LV end-diastolic volume index, stroke volume index, wall motion in segment 9, and heart rate showed significant difference

  17. Profiles of ion beams and plasma parameters on a multi-frequencies microwaves large bore electron cyclotron resonance ion source with permanent magnets

    SciTech Connect

    Kato, Yushi; Sakamoto, Naoki; Kiriyama, Ryutaro; Takenaka, Tomoya; Kurisu, Yosuke; Nozaki, Dai; Sato, Fuminobu; Iida, Toshiyuki

    2012-02-15

    In order to contribute to various applications of plasma and beams based on an electron cyclotron resonance, a new concept on magnetic field with all magnets on plasma production and confinement has been proposed with enhanced efficiency for broad and dense ion beam. The magnetic field configuration consists of a pair of comb-shaped magnet surrounding plasma chamber cylindrically. Resonance zones corresponding for 2.45 GHz and 11-13 GHz frequencies are positioned at spatially different positions. We launch simultaneously multiplex frequencies microwaves operated individually, try to control profiles of the plasma parameters and the extracted ion beams, and to measure them in detail.

  18. Evaluation of kinetic constants of biomolecular interaction on optical surface plasmon resonance sensor with Newton Iteration Method

    NASA Astrophysics Data System (ADS)

    Zhao, Yuanyuan; Jiang, Guoliang; Hu, Jiandong; Hu, Fengjiang; Wei, Jianguang; Shi, Liang

    2010-10-01

    In the immunology, there are two important types of biomolecular interaction: antigens-antibodies and receptors-ligands. Monitoring the response rate and affinity of biomolecular interaction can help analyze the protein function, drug discover, genomics and proteomics research. Moreover the association rate constant and dissociation rate constant of receptors-ligands are the important parameters for the study of signal transmission between cells. Recent advances in bioanalyzer instruments have greatly simplified the measurement of the kinetics of molecular interactions. Non-destructive and real-time monitoring the response to evaluate the parameters between antigens and antibodies can be performed by using optical surface plasmon resonance (SPR) biosensor technology. This technology provides a quantitative analysis that is carried out rapidly with label-free high-throughput detection using the binding curves of antigens-antibodies. Consequently, the kinetic parameters of interaction between antigens and antibodies can be obtained. This article presents a low cost integrated SPR-based bioanalyzer (HPSPR-6000) designed by ourselves. This bioanalyzer is mainly composed of a biosensor TSPR1K23, a touch-screen monitor, a microprocessor PIC24F128, a microflow cell with three channels, a clamp and a photoelectric conversion device. To obtain the kinetic parameters, sensorgrams may be modeled using one of several binding models provided with BIAevaluation software 3.0, SensiQ or Autolab. This allows calculation of the association rate constant (ka) and the dissociation rate constant (kd). The ratio of ka to kd can be used to estimate the equilibrium constant. Another kind is the analysis software OriginPro, which can process the obtained data by nonlinear fitting and then get some correlative parameters, but it can't be embedded into the bioanalyzer, so the bioanalyzer don't support the use of OriginPro. This paper proposes a novel method to evaluate the kinetic parameters

  19. Cassette Sync Recorders. Parameter for Evaluation. Laboratory Test Findings. EPIE Report Number 86e.

    ERIC Educational Resources Information Center

    Educational Products Information Exchange Inst., Stony Brook, NY.

    This quarterly report by the Educational Products Information Exchange (EPIE) analyzes cassette sync recorders, giving parameters for evaluation and laboratory test findings. The report offers evaluations of the compatibility of different models and the standards for audio and cue tones. It also discusses national and international standards, EPIE…

  20. Improved Quantification of Cerebral Hemodynamics Using Individualized Time Thresholds for Assessment of Peak Enhancement Parameters Derived from Dynamic Susceptibility Contrast Enhanced Magnetic Resonance Imaging

    PubMed Central

    Nasel, Christian; Kalcher, Klaudius; Boubela, Roland; Moser, Ewald

    2014-01-01

    Purpose Assessment of cerebral ischemia often employs dynamic susceptibility contrast enhanced magnetic resonance imaging (DSC-MRI) with evaluation of various peak enhancement time parameters. All of these parameters use a single time threshold to judge the maximum tolerable peak enhancement delay that is supposed to reliably differentiate sufficient from critical perfusion. As the validity of this single threshold approach still remains unclear, in this study, (1) the definition of a threshold on an individual patient-basis, nevertheless (2) preserving the comparability of the data, was investigated. Methods The histogram of time-to-peak (TTP) values derived from DSC-MRI, the so-called TTP-distribution curve (TDC), was modeled using a double-Gaussian model in 61 patients without severe cerebrovascular disease. Particular model-based zf-scores were used to describe the arterial, parenchymal and venous bolus-transit phase as time intervals Ia,p,v. Their durations (delta Ia,p,v), were then considered as maximum TTP-delays of each phase. Results Mean-R2 for the model-fit was 0.967. Based on the generic zf-scores the proposed bolus transit phases could be differentiated. The Ip-interval reliably depicted the parenchymal bolus-transit phase with durations of 3.4 s–10.1 s (median = 4.3s), where an increase with age was noted (∼30 ms/year). Conclusion Individual threshold-adjustment seems rational since regular bolus-transit durations in brain parenchyma obtained from the TDC overlap considerably with recommended critical TTP-thresholds of 4 s–8 s. The parenchymal transit time derived from the proposed model may be utilized to individually correct TTP-thresholds, thereby potentially improving the detection of critical perfusion. PMID:25521121

  1. Magnetic resonance imaging of the chest in the evaluation of cancer patients: state of the art

    PubMed Central

    Guimaraes, Marcos Duarte; Hochhegger, Bruno; Santos, Marcel Koenigkam; Santana, Pablo Rydz Pinheiro; Sousa, Arthur Soares; Souza, Luciana Soares; Marchiori, Edson

    2015-01-01

    Magnetic resonance imaging (MRI) has several advantages in the evaluation of cancer patients with thoracic lesions, including involvement of the chest wall, pleura, lungs, mediastinum, esophagus and heart. It is a quite useful tool in the diagnosis, staging, surgical planning, treatment response evaluation and follow-up of these patients. In the present review, the authors contextualize the relevance of MRI in the evaluation of thoracic lesions in cancer patients. Considering that MRI is a widely available method with high contrast and spatial resolution and without the risks associated with the use of ionizing radiation, its use combined with new techniques such as cine-MRI and functional methods such as perfusion- and diffusion-weighted imaging may be useful as an alternative tool with performance comparable or complementary to conventional radiological methods such as radiography, computed tomography and PET/CT imaging in the evaluation of patients with thoracic neoplasias. PMID:25798006

  2. Magnetic resonance imaging of the chest in the evaluation of cancer patients: state of the art.

    PubMed

    Guimaraes, Marcos Duarte; Hochhegger, Bruno; Santos, Marcel Koenigkam; Santana, Pablo Rydz Pinheiro; Sousa, Arthur Soares; Souza, Luciana Soares; Marchiori, Edson

    2015-01-01

    Magnetic resonance imaging (MRI) has several advantages in the evaluation of cancer patients with thoracic lesions, including involvement of the chest wall, pleura, lungs, mediastinum, esophagus and heart. It is a quite useful tool in the diagnosis, staging, surgical planning, treatment response evaluation and follow-up of these patients. In the present review, the authors contextualize the relevance of MRI in the evaluation of thoracic lesions in cancer patients. Considering that MRI is a widely available method with high contrast and spatial resolution and without the risks associated with the use of ionizing radiation, its use combined with new techniques such as cine-MRI and functional methods such as perfusion- and diffusion-weighted imaging may be useful as an alternative tool with performance comparable or complementary to conventional radiological methods such as radiography, computed tomography and PET/CT imaging in the evaluation of patients with thoracic neoplasias.

  3. Appearance of monoclonal plasma cell diseases in whole-body magnetic resonance imaging and correlation with parameters of disease activity.

    PubMed

    Kloth, Jost K; Hillengass, Jens; Listl, Karin; Kilk, Kerstin; Hielscher, Thomas; Landgren, Ola; Delorme, Stefan; Goldschmidt, Hartmut; Kauczor, Hans-Ulrich; Weber, Marc-André

    2014-11-15

    The aim of our study was to assess in which way different infiltration patterns of monoclonal plasma cell diseases in whole-body (wb) magnetic resonance imaging (MRI) are associated with clinical stages, plasma cell content in bone marrow samples and established serum markers of disease activity. Institutional review board approval was obtained. We performed wb-MRI in 547 consecutive, unselected and untreated patients with monoclonal gammopathy of undetermined significance (MGUS, n=138), smoldering myeloma (SMM, n=157) and multiple myeloma (MM, n=252) on two 1.5 T MRI-scanners with body array coils. The studies were evaluated in consensus by two experienced radiologists blinded to the diagnosis. We observed focal lesions in 23.9% (MGUS), 34.4% (SMM) and 81.3% (MM), respectively. A diffuse infiltration pattern was detected in 38.4%, 45.9% and 71%, respectively. The differences between all infiltration patterns were significant (p<0.0001). The presence of focal lesions and the presence of a diffuse bone marrow infiltration was associated with an increased plasma cell percentage in bone marrow samples (median 22% vs. 14%, 26% vs. 10%, both p<0.0001) and monoclonal protein concentration (median 18 g/dl vs. 13 g/dl, p=0.003, 20 g/dl vs. 11 g/dl, p<0.0001). Further categorization of the diffuse infiltration patterns in wb-MRI into "salt-and-pepper," moderate and severe identified significant associations with M-protein (median g/dl for S+P/moderate/severe 23/18/25, p=0.04), plasma cell percentage in the bone marrow (median 25%/24%/40%, p=0.02), and age (median years 67/60/57, p<0.0001). Bone marrow infiltration in wb-MRI is significantly different between the various stages of plasma cell disease and correlates well with established markers of disease activity. PMID:24706394

  4. Magnetic resonance imaging of the liver: New imaging strategies for evaluating focal liver lesions

    PubMed Central

    Coenegrachts, Kenneth

    2009-01-01

    The early detection of focal liver lesions, particularly those which are malignant, is of utmost importance. The resection of liver metastases of some malignancies (including colorectal cancer) has been shown to improve the survival of patients. Exact knowledge of the number, size, and regional distribution of liver metastases is essential to determine their resectability. Almost all focal liver lesions larger than 10 mm are demonstrated with current imaging techniques but the detection of smaller focal liver lesions is still relatively poor. One of the advantages of magnetic resonance imaging (MRI) of the liver is better soft tissue contrast (compared to other radiologic modalities), which allows better detection and characterization of the focal liver lesions in question. Developments in MRI hardware and software and the availability of novel MRI contrast agents have further improved the diagnostic yield of MRI in lesion detection and characterization. Although the primary modalities for liver imaging are ultrasound and computed tomography, recent studies have suggested that MRI is the most sensitive method for detecting small liver metastatic lesions, and MRI is now considered the pre-operative standard method for diagnosis. Two recent developments in MRI sequences for the upper abdomen comprise unenhanced diffusion-weighted imaging (DWI), and keyhole-based dynamic contrast-enhanced (DCE) MRI (4D THRIVE). DWI allows improved detection (b = 10 s/mm2) of small (< 10 mm) focal liver lesions in particular, and is useful as a road map sequence. Also, using higher b-values, the calculation of the apparent diffusion coefficient value, true diffusion coefficient, D, and the perfusion fraction, f, has been used for the characterization of focal liver lesions. DCE 4D THRIVE enables MRI of the liver with high temporal and spatial resolution and full liver coverage. 4D THRIVE improves evaluation of focal liver lesions, providing multiple arterial and venous phases, and

  5. Sperm motility parameters to evaluate the seminal quality of Boa constrictor occidentalis, a threatened snake species.

    PubMed

    Tourmente, M; Cardozo, G A; Guidobaldi, H A; Giojalas, L C; Bertona, M; Chiaraviglio, M

    2007-02-01

    Semen quality analysis constitutes a powerful tool to evaluate the fertility potential of males in threatened species. The Argentine boa constrictor or lampalagua (Boa constrictor occidentalis) is a threatened snake species and has been included in Appendix I of CITES. The objective of this work is to characterize the sperm of B. c. occidentalis on the bases of dynamic parameters to improve this species conservation. Dynamic parameters were measured in sperm samples using videomicroscopy and image analysis software. The sperm population showed a high degree of heterogeneity in velocity parameter values and 95% of the cells showed a linear pattern of movement. Studies in other species indicate that the number of motile spermatozoa and their movement speed is directly correlated with fertilization success. This work will help to establish basic parameter values for the evaluation of the reproductive potential of populations of B. c. occidentalis and to resolve questions referred to its reproductive strategies.

  6. Recent results of the parameters A and R measurements in the resonance region of the πN-elastic scattering and subsequent investigations.

    NASA Astrophysics Data System (ADS)

    Sumachev, V. V.; Beloglazov, Yu. A.; Filimonov, E. A.; Kovalev, A. I.; Kozlenko, N. G.; Kruglov, S. P.; Kulbardis, A. A.; Lopatin, I. V.; Novinsky, D. V.; Shchedrov, V. A.; Trautman, V. Yu.; Alekseev, I. G.; Budkovsky, P. E.; Kanavets, V. P.; Koroleva, L. I.; Morozov, B. V.; Nesterov, V. M.; Ryltsov, V. V.; Sulimov, A. D.; Svirida, D. N.; Bazhanov, N. A.; Bunyatova, E. I.

    2008-10-01

    The existing models of baryons usually predict considerably more resonance (three or more in number) than it was found by investigation of elastic pion-nucleon scattering. This disagreement invites further investigation of the pion-nucleon interaction and among other things the measurement of spin rotation parameters A and R in the elastic pion-nucleon scattering. Recent experiments of the PNPI and PNPI-ITEP collaborations resolved a part of twofold ambiguities of the existing partial wave analyses (PWA). These results were used in the last PWA of the George Washington University group SP06. The proposal for the additional spin rotation parameters A and R measurement in the resonance region is motivated. Such additional measurements are necessary to resolve remaining twofold ambiguities of the existing PWAs.

  7. Recent results of the parameters A and R measurements in the resonance region of the {pi}N-elastic scattering and subsequent investigations

    SciTech Connect

    Sumachev, V. V.; Beloglazov, Yu. A.; Filimonov, E. A.; Kovalev, A. I.; Kozlenko, N. G.; Kruglov, S. P.; Kulbardis, A. A.; Lopatin, I. V.; Novinsky, D. V.; Shchedrov, V. A.; Trautman, V. Yu.; Alekseev, I. G.; Budkovsky, P. E.; Kanavets, V. P.; Koroleva, L. I.; Morozov, B. V.; Nesterov, V. M.; Ryltsov, V. V.; Sulimov, A. D.; Svirida, D. N.

    2008-10-13

    The existing models of baryons usually predict considerably more resonance (three or more in number) than it was found by investigation of elastic pion-nucleon scattering. This disagreement invites further investigation of the pion-nucleon interaction and among other things the measurement of spin rotation parameters A and R in the elastic pion-nucleon scattering.Recent experiments of the PNPI and PNPI-ITEP collaborations resolved a part of twofold ambiguities of the existing partial wave analyses (PWA). These results were used in the last PWA of the George Washington University group SP06. The proposal for the additional spin rotation parameters A and R measurement in the resonance region is motivated. Such additional measurements are necessary to resolve remaining twofold ambiguities of the existing PWAs.

  8. Evaluation of intragranular misorientation parameters measured by EBSD in a hot worked austenitic stainless steel.

    PubMed

    Jorge-Badiola, D; Iza-Mendia, A; Gutiérrez, I

    2007-12-01

    An extensive characterization of hot deformed austenitic stainless steel was carried out using the electron backscatter diffraction technique. Special emphasis was given to the misorientation parameters related to different length scales. These parameters show a behaviour that is sensitive to the amount of applied strain and also lead to increasing values for both the strain and the scale length. At the same time, the use of different thresholds and scan steps in the evaluation of the parameters were analyzed in order to assess the validity of the results. PMID:18045332

  9. Evaluation of toroidal torque by non-resonant magnetic perturbations in tokamaks for resonant transport regimes using a Hamiltonian approach

    NASA Astrophysics Data System (ADS)

    Albert, Christopher G.; Heyn, Martin F.; Kapper, Gernot; Kasilov, Sergei V.; Kernbichler, Winfried; Martitsch, Andreas F.

    2016-08-01

    Toroidal torque generated by neoclassical viscosity caused by external non-resonant, non-axisymmetric perturbations has a significant influence on toroidal plasma rotation in tokamaks. In this article, a derivation for the expressions of toroidal torque and radial transport in resonant regimes is provided within quasilinear theory in canonical action-angle variables. The proposed approach treats all low-collisional quasilinear resonant neoclassical toroidal viscosity regimes including superbanana-plateau and drift-orbit resonances in a unified way and allows for magnetic drift in all regimes. It is valid for perturbations on toroidally symmetric flux surfaces of the unperturbed equilibrium without specific assumptions on geometry or aspect ratio. The resulting expressions are shown to match the existing analytical results in the large aspect ratio limit. Numerical results from the newly developed code NEO-RT are compared to calculations by the quasilinear version of the code NEO-2 at low collisionalities. The importance of the magnetic shear term in the magnetic drift frequency and a significant effect of the magnetic drift on drift-orbit resonances are demonstrated.

  10. Evaluation of Three Methods for Determining EMG-Muscle Force Parameter Estimates for the Shoulder Muscles

    PubMed Central

    Gatti, Christopher J.; Doro, Lisa Case; Langenderfer, Joseph E.; Mell, Amy G.; Maratt, Joseph D.; Carpenter, James E.; Hughes, Richard E.

    2008-01-01

    Background Accurate prediction of in vivo muscle forces is essential for relevant analyses of musculoskeletal biomechanics. The purpose of this study was to evaluate three methods for predicting muscle forces of the shoulder by comparing calculated muscle parameters, which relate electromyographic activity to muscle forces. Methods Thirteen subjects performed sub-maximal, isometric contractions consisting of six actions about the shoulder and two actions about the elbow. Electromyography from 12 shoulder muscles and internal shoulder moments were used to determine muscle parameters using traditional multiple linear regression, principal-components regression, and a sequential muscle parameter determination process using principal-components regression. Muscle parameters were evaluated based on their sign (positive or negative), standard deviations, and error between the measured and predicted internal shoulder moments. Findings It was found that no method was superior with respect to all evaluation criteria. The sequential principal-components regression method most frequently produced muscle parameters that could be used to estimate muscle forces, multiple regression best predicted the measured internal shoulder moments, and the results of principal-components regression fell between those of sequential principal-components regression and multiple regression. Interpretation The selection of a muscle parameter estimation method should be based on the importance of the evaluation criteria. Sequential principal-components regression should be used if a greater number of physiologically accurate muscle forces are desired, while multiple regression should be used for a more accurate prediction of measured internal shoulder moments. However, all methods produced muscle parameters which can be used to predict in vivo muscle forces of the shoulder. PMID:17945401

  11. Non-Destructive Evaluation of Kissing Bonds using Local Defect Resonance (LDR) Spectroscopy: A Simulation Study

    NASA Astrophysics Data System (ADS)

    Delrue, S.; Tabatabaeipour, M.; Hettler, J.; Van Den Abeele, K.

    With the growing demand from industry to optimize and further develop existing Non-Destructive Testing & Evaluation (NDT&E) techniques or new methods to detect and characterize incipient damage with high sensitivity and increased quality, ample efforts have been devoted to better understand the typical behavior of kissing bonds, such as delaminations and cracks. Recently, it has been shown experimentally that the nonlinear ultrasonic response of kissing bonds could be enhanced by using Local Defect Resonance (LDR) spectroscopy. LDR spectroscopy is an efficient NDT technique that takes advantage of the characteristic fre- quencies of the defect (defect resonances) in order to provide maximum acoustic wave-defect interaction. In fact, for nonlinear methodologies, the ultrasonic excitation of the sample should occur at either multiples or integer ratios of the characteristic defect resonance frequencies, in order to obtain the highest signal-to-noise response in the nonlinear LDR spectroscopy. In this paper, the potential of using LDR spectroscopy for the detection, localization and characterization of kissing bonds is illustrated using a 3D simulation code for elastic wave propagation in materials containing closed but dynamically active cracks or delaminations. Using the model, we are able to define an appropriate method, based on the Scaling Subtraction Method (SSM), to determine the local defect resonance frequencies of a delamination in a composite plate and to illustrate an increase in defect nonlinearity due to LDR. The simulation results will help us to obtain a better understanding of the concept of LDR and to assist in the further design and testing of LDR spectroscopy for the detection, localization and characterization of kissing bonds.

  12. Radiological evaluation by magnetic resonance of the 'new anatomy' of transsexual patients undergoing male to female sex reassignment surgery.

    PubMed

    Brunocilla, E; Soli, M; Franceschelli, A; Schiavina, R; Borghesi, M; Gentile, G; Pultrone, C V; Martorana, G; Orrei, M G; Colombo, F

    2012-09-01

    Magnetic resonance (MR) is the best way to assess the new anatomy of the pelvis after male to female (MtF) sex reassignment surgery. The aim of the study was to evaluate the radiological appearance of the small pelvis after MtF surgery and to compare it with the normal women's anatomy. Fifteen patients who underwent MtF surgery were subjected to pelvic MR at least 6 months after surgery. The anthropometric parameters of the small pelvis were measured and compared with those of ten healthy women (control group). Our personal technique (creation of the mons Veneris under the pubic skin) was performed in all patients. In patients who underwent MtF surgery, the mean neovaginal depth was slightly superior than in women (P=0.009). The length of the inferior pelvic aperture and of the inlet of pelvis was higher in the control group (P<0.005). The inclination between the axis of the neovagina and the inferior pelvis aperture, the thickness of the mons Veneris and the thickness of the rectovaginal septum were comparable between the two study groups. MR consents a detailed assessment of the new pelvic anatomy after MtF surgery. The anthropometric parameters measured in our patients were comparable with those of women.

  13. Important Physiological Parameters and Physical Activity Data for Evaluating Exposure Modeling Performance: a Synthesis

    EPA Science Inventory

    The purpose of this report is to develop a database of physiological parameters needed for understanding and evaluating performance of the APEX and SHEDS exposure/intake dose rate model used by the Environmental Protection Agency (EPA) as part of its regulatory activities. The A...

  14. SENSITIVE PARAMETER EVALUATION FOR A VADOSE ZONE FATE AND TRANSPORT MODEL

    EPA Science Inventory

    This report presents information pertaining to quantitative evaluation of the potential impact of selected parameters on output of vadose zone transport and fate models used to describe the behavior of hazardous chemicals in soil. The Vadose 2one Interactive Processes (VIP) model...

  15. Electrical and ionic conductivity effects on magic-angle spinning nuclear magnetic resonance parameters of CuI.

    PubMed

    Yesinowski, James P; Ladouceur, Harold D; Purdy, Andrew P; Miller, Joel B

    2010-12-21

    We investigate experimentally and theoretically the effects of two different types of conductivity, electrical and ionic, upon magic-angle spinning NMR spectra. The experimental demonstration of these effects involves (63)Cu, (65)Cu, and (127)I variable temperature MAS-NMR experiments on samples of γ-CuI, a Cu(+)-ion conductor at elevated temperatures as well as a wide bandgap semiconductor. We extend previous observations that the chemical shifts depend very strongly upon the square of the spinning-speed as well as the particular sample studied and the magnetic field strength. By using the (207)Pb resonance of lead nitrate mixed with the γ-CuI as an internal chemical shift thermometer we show that frictional heating effects of the rotor do not account for the observations. Instead, we find that spinning bulk CuI, a p-type semiconductor due to Cu(+) vacancies in nonstoichiometric samples, in a magnetic field generates induced AC electric currents from the Lorentz force that can resistively heat the sample by over 200 °C. These induced currents oscillate along the rotor spinning axis at the spinning speed. Their associated heating effects are disrupted in samples containing inert filler material, indicating the existence of macroscopic current pathways between micron-sized crystallites. Accurate measurements of the temperature-dependence of the (63)Cu and (127)I chemical shifts in such diluted samples reveal that they are of similar magnitude (ca. 0.27 ppm/K) but opposite sign (being negative for (63)Cu), and appear to depend slightly upon the particular sample. This relationship is identical to the corresponding slopes of the chemical shifts versus square of the spinning speed, again consistent with sample heating as the source of the observed large shift changes. Higher drive-gas pressures are required to spin samples that have higher effective electrical conductivities, indicating the presence of a braking effect arising from the induced currents produced by

  16. Electrical and ionic conductivity effects on magic-angle spinning nuclear magnetic resonance parameters of CuI

    NASA Astrophysics Data System (ADS)

    Yesinowski, James P.; Ladouceur, Harold D.; Purdy, Andrew P.; Miller, Joel B.

    2010-12-01

    We investigate experimentally and theoretically the effects of two different types of conductivity, electrical and ionic, upon magic-angle spinning NMR spectra. The experimental demonstration of these effects involves 63Cu, 65Cu, and 127I variable temperature MAS-NMR experiments on samples of γ-CuI, a Cu+-ion conductor at elevated temperatures as well as a wide bandgap semiconductor. We extend previous observations that the chemical shifts depend very strongly upon the square of the spinning-speed as well as the particular sample studied and the magnetic field strength. By using the 207Pb resonance of lead nitrate mixed with the γ-CuI as an internal chemical shift thermometer we show that frictional heating effects of the rotor do not account for the observations. Instead, we find that spinning bulk CuI, a p-type semiconductor due to Cu+ vacancies in nonstoichiometric samples, in a magnetic field generates induced AC electric currents from the Lorentz force that can resistively heat the sample by over 200 °C. These induced currents oscillate along the rotor spinning axis at the spinning speed. Their associated heating effects are disrupted in samples containing inert filler material, indicating the existence of macroscopic current pathways between micron-sized crystallites. Accurate measurements of the temperature-dependence of the 63Cu and 127I chemical shifts in such diluted samples reveal that they are of similar magnitude (ca. 0.27 ppm/K) but opposite sign (being negative for 63Cu), and appear to depend slightly upon the particular sample. This relationship is identical to the corresponding slopes of the chemical shifts versus square of the spinning speed, again consistent with sample heating as the source of the observed large shift changes. Higher drive-gas pressures are required to spin samples that have higher effective electrical conductivities, indicating the presence of a braking effect arising from the induced currents produced by rotating a

  17. Inverse modeling approach for evaluation of kinetic parameters of a biofilm reactor using tabu search.

    PubMed

    Kumar, B Shiva; Venkateswarlu, Ch

    2014-08-01

    The complex nature of biological reactions in biofilm reactors often poses difficulties in analyzing such reactors experimentally. Mathematical models could be very useful for their design and analysis. However, application of biofilm reactor models to practical problems proves somewhat ineffective due to the lack of knowledge of accurate kinetic models and uncertainty in model parameters. In this work, we propose an inverse modeling approach based on tabu search (TS) to estimate the parameters of kinetic and film thickness models. TS is used to estimate these parameters as a consequence of the validation of the mathematical models of the process with the aid of measured data obtained from an experimental fixed-bed anaerobic biofilm reactor involving the treatment of pharmaceutical industry wastewater. The results evaluated for different modeling configurations of varying degrees of complexity illustrate the effectiveness of TS for accurate estimation of kinetic and film thickness model parameters of the biofilm process. The results show that the two-dimensional mathematical model with Edward kinetics (with its optimum parameters as mu(max)rho(s)/Y = 24.57, Ks = 1.352 and Ki = 102.36) and three-parameter film thickness expression (with its estimated parameters as a = 0.289 x 10(-5), b = 1.55 x 10(-4) and c = 15.2 x 10(-6)) better describes the biofilm reactor treating the industry wastewater.

  18. The role of magnetic resonance imaging in the evaluation of transfusional iron overload in myelodysplastic syndromes

    PubMed Central

    Petrou, Emmanouil; Mavrogeni, Sophie; Karali, Vasiliki; Kolovou, Genovefa; Kyrtsonis, Marie-Christine; Sfikakis, Petros P.; Panayiotidis, Panayiotis

    2015-01-01

    Myelodysplastic syndromes represent a group of heterogeneous hematopoietic neoplasms derived from an abnormal multipotent progenitor cell, characterized by a hyperproliferative bone marrow, dysplasia of the cellular hemopoietic elements and ineffective erythropoiesis. Anemia is a common finding in myelodysplastic syndrome patients, and blood transfusions are the only therapeutic option in approximately 40% of cases. The most serious side effect of regular blood transfusion is iron overload. Currently, cardiovascular magnetic resonance using T2 is routinely used to identify patients with myocardial iron overload and to guide chelation therapy, tailored to prevent iron toxicity in the heart. This is a major validated non-invasive measure of myocardial iron overloading and is superior to surrogates such as serum ferritin, liver iron, ventricular ejection fraction and tissue Doppler parameters. The indication for iron chelation therapy in myelodysplastic syndrome patients is currently controversial. However, cardiovascular magnetic resonance may offer an excellent non-invasive, diagnostic tool for iron overload assessment in myelodysplastic syndromes. Further studies are needed to establish the precise indications of chelation therapy and the clinical implications of this treatment on survival in myelodysplastic syndromes. PMID:26190429

  19. The role of magnetic resonance imaging in the evaluation of transfusional iron overload in myelodysplastic syndromes.

    PubMed

    Petrou, Emmanouil; Mavrogeni, Sophie; Karali, Vasiliki; Kolovou, Genovefa; Kyrtsonis, Marie-Christine; Sfikakis, Petros P; Panayiotidis, Panayiotis

    2015-01-01

    Myelodysplastic syndromes represent a group of heterogeneous hematopoietic neoplasms derived from an abnormal multipotent progenitor cell, characterized by a hyperproliferative bone marrow, dysplasia of the cellular hemopoietic elements and ineffective erythropoiesis. Anemia is a common finding in myelodysplastic syndrome patients, and blood transfusions are the only therapeutic option in approximately 40% of cases. The most serious side effect of regular blood transfusion is iron overload. Currently, cardiovascular magnetic resonance using T2 is routinely used to identify patients with myocardial iron overload and to guide chelation therapy, tailored to prevent iron toxicity in the heart. This is a major validated non-invasive measure of myocardial iron overloading and is superior to surrogates such as serum ferritin, liver iron, ventricular ejection fraction and tissue Doppler parameters. The indication for iron chelation therapy in myelodysplastic syndrome patients is currently controversial. However, cardiovascular magnetic resonance may offer an excellent non-invasive, diagnostic tool for iron overload assessment in myelodysplastic syndromes. Further studies are needed to establish the precise indications of chelation therapy and the clinical implications of this treatment on survival in myelodysplastic syndromes.

  20. Relating objective measurements to expert evaluation of voice quality in Western classical singing: critical perceptual parameters.

    PubMed

    Ekholm, E; Papagiannis, G C; Chagnon, F P

    1998-06-01

    Communication between voice pedagogues and voice scientists is often impeded by reliance on colorful and sometimes seemingly contradictory descriptions of vocal production and voice quality. A recent study identified perceptual criteria which are generally used by voice experts for the assessment of voice quality in classical singing. In the present study, performances by singers of various voice types and levels of accomplishment were rated by panels of expert voice teachers according to four perceptual criteria: "resonance/ring," "color/warmth," "clarity/focus," and "appropriate vibrato." Subjective ratings were related to objective measurements taken from acoustic analysis of the voice signal. Possible acoustic correlates of critical perceptual parameters influencing judgments of voice quality were thus identified. Results could help bridge the terminology gap between vocal artists and scientists, and help to promote understanding of the way in which acoustic stimuli influence perception of voice quality. PMID:9649074

  1. An infant with diaphragmatic hernia, anophthalmia and cardiac defect: evaluation by magnetic resonance imaging autopsy.

    PubMed

    Ceylaner, S; Gozer, H E; Ceylaner, G; Ertas, I E; Kizilates, S U; Edguer, T

    2006-01-01

    We present an infant with diaphragmatic hernia, anophthalmia and cardiac defect evaluated by magnetic resonance imaging (MRI) autopsy. This female infant was born at 39th weeks by vaginal delivery and presented with diaphragmatic hernia, anophthalmia, cardiac defect and died due to respiratory problems at 28th hours of life. MRI autopsy showed internal organ abnormalities including congenital hernia of the left diaphragm, secondary hypoplasia of the left lung, atrial and ventricular septal defect, dilatation of calices of the kidneys, bilateral anophthalmia, hypoplasia of the optic nerves, hyperintensity of pituitary gland possibly due to bleeding and a cyst of the septum pellucidum. This article shows that MRI autopsy is a valuable method for the evaluation of cases with congenital anomalies if autopsy is not possible.

  2. Evaluation of Possible Nuclear Magnetic Resonance Diagnostic Techniques for Tokamak Experiments

    SciTech Connect

    S.J. Zweben; T.W. Kornack; D. Majeski; G. Schilling; C.H. Skinner; R. Wilson

    2002-08-05

    Potential applications of nuclear magnetic resonance (NMR) diagnostic techniques to tokamak experiments are evaluated. NMR frequencies for hydrogen isotopes and low-Z nuclei in such experiments are in the frequency range approximately equal to 20-200 MHz, so existing RF [radio-frequency] antennas could be used to rotate the spin polarization and to make the NMR measurements. Our tentative conclusion is that such measurements are possible if highly spin polarized H or (superscript)3He gas sources (which exist) are used to fuel these plasmas. In addition, NMR measurements of the surface layers of the first wall (without plasma) may also be possible, e.g., to evaluate the inventory of tritium inside the vessel.

  3. Evaluation Of Automated Low-Field Nuclear Magnetic Resonance (NMR) Relaxometry For Analysis Of Silicone Polymers

    SciTech Connect

    M. H. Wilson

    2009-10-02

    Screening studies and Design of Experiments (DoE) were performed to evaluate measurement variation of a new, non-destructive Nuclear Magnetic Resonance (NMR) test system designed to assess age-induced degradation of Outer Pressure Pads (OPP). The test method and results from 54,275 measurements are described. A reduction in measurement error was obtained after metal support struts were replaced with plastic support struts adjacent to the front position of the test chamber. However, remaining interference and a lack of detecting any age-related degradation prevent the use of the NMR system as a non-destructive surveillance test for OPPs. A cursory evaluation of the system with cellular silicone samples obtained more uniform results with increased error as measurements approached the sample’s edge.

  4. Radar target identification by natural resonances: Evaluation of signal processing algorithms

    NASA Astrophysics Data System (ADS)

    Lazarakos, Gregory A.

    1991-09-01

    When a radar pulse impinges upon a target, the resultant scattering process can be solved as a linear time-invariant (LTI) system problem. The system has a transfer function with poles and zeros. Previous work has shown that the poles are independent on the target's structure and geometry. This thesis evaluates the resonance estimation performance of two signal processing techniques: the Kumaresan-Tufts algorithm and the Cadzow-Solomon algorithm. Improvements are made to the Cadzow-Solomon algorithm. Both algorithms are programmed using MATLAB. Test data used to evaluate these algorithms includes synthetic and integral equation generated signals, with and without additive noise, in addition to new experimental scattering data from a thin wire, aluminum spheres, and scale model aircraft.

  5. Numerical evaluation of aperture coupling in resonant cavities and frequency perturbation analysis

    NASA Astrophysics Data System (ADS)

    Dash, R.; Nayak, B.; Sharma, A.; Mittal, K. C.

    2014-01-01

    This paper presents a general formulation for numerical evaluation of the coupling between two identical resonant cavities by a small elliptical aperture in a plane common wall of arbitrary thickness. It is organized into two parts. In the first one we discuss the aperture coupling that is expressed in terms of electric and magnetic dipole moments and polarizabilities using Carlson symmetric elliptical integrals. Carlson integrals have been numerically evaluated and under zero thickness approximation, the results match with the complete elliptical integrals of first and second kind. It is found that with zero wall thickness, the results obtained are the same as those of Bethe and Collin for an elliptical and circular aperture of zero thickness. In the second part, Slater's perturbation method is applied to find the frequency changes due to apertures of finite thickness on the cavity wall.

  6. Impact of gamma analysis parameters on dose evaluation using Gafchromic EBT2 films

    NASA Astrophysics Data System (ADS)

    Lee, Seu-Ran; Park, Ji-Yeon; Suh, Tae-Suk; Park, Hae-Jin; Lee, Jeong-Woo; Jung, Won-Gyun

    2012-10-01

    To recommend optimal gamma analysis parameters (grid size and search range) for detecting dose errors, we evaluated the impact of gamma models and parameters on dose verification in volumetric modulated fields. Delivered doses were verified under open, 45° wedged, and volumetric modulated fields for prostate, anal, head and neck, and brain cancer by using Gafchromic EBT2 films for gamma evaluation. Two gamma models (a conventional method and a modified method to compensate for unintended dose errors caused by misalignments between reference and evaluated matrixes) were employed. The variation in the detected dose errors was evaluated in each gamma model for different grid sizes (0.5, 1, and 2 mm) and search ranges (1, 2, and 4 mm) applied to determine distant-to-agreement. The dose discrepancy of each evaluation was qualitatively and quantitatively evaluated using a pass ratio in analysis software developed in-house. The modified gamma model with a small search range and grid size showed a higher pass ratio than the conventional model in volumetric modulated arc therapy. The pass ratio for 2 mm grid size decreased by over 40% as compared to that for 1 mm grid size. The pass ratio decreased by more than 30% as the search range was increased from 1 mm to 4 mm. Therefore, 1 mm grid size and 1 mm search range may be appropriate to evaluate dose errors in modulated fields after using the modified gamma model.

  7. Evaluation of the effectiveness of the new tooth wear measurement parameters

    PubMed Central

    Lee, Sang-Hak; Nam, Shin-Eun

    2015-01-01

    Nowadays, there has been an increasing interest in the preservation of natural dentition and the proper occlusion related to tooth wear for quality of life. To overcome the problems of the existing qualitative tooth wear analysis method, virtual three-dimensional models have been used. This study was designed to develop and validate a new quantitative method using tooth wear measurement parameters with angles obtained from virtual vectors and planes of the three-dimensional models. Sixteen parameters were evaluated in the virtual models of 20 students (7.57±1.55 years old) and 20 adults (56.85±6.34 years old). There were 12 angle and 4 height parameters, and the number of parameters measured from the virtual planes and vectors were 10 and 6, respectively. For each parameter, means and standard deviations were calculated, and an unpaired sample t test was performed to compare the young and the adult groups. Also, differences between the means were determined and expressed as percentages. The results were statistically significant between the two groups (P<0.001). In general, parameters using virtual vectors showed greater change than virtual plane. Although there were statistically significant differences among all parameters using virtual planes (P<0.001), the changes of the three angles were similar, except distolingual cusp angle. It was found that the parameters using virtual vectors were effective and tooth wear took place in both buccal and lingual cusps. Likewise, the validation of the new measurement parameters suggests that they can also be applied in the assessment of tooth wear related to dental biomaterials. PMID:26770880

  8. Evaluation and interpretation of Thematic Mapper ratios in equations for estimating corn growth parameters

    NASA Technical Reports Server (NTRS)

    Dardner, B. R.; Blad, B. L.; Thompson, D. R.; Henderson, K. E.

    1985-01-01

    Reflectance and agronomic Thematic Mapper (TM) data were analyzed to determine possible data transformations for evaluating several plant parameters of corn. Three transformation forms were used: the ratio of two TM bands, logarithms of two-band ratios, and normalized differences of two bands. Normalized differences and logarithms of two-band ratios responsed similarly in the equations for estimating the plant growth parameters evaluated in this study. Two-term equations were required to obtain the maximum predictability of percent ground cover, canopy moisture content, and total wet phytomass. Standard error of estimate values were 15-26 percent lower for two-term estimates of these parameters than for one-term estimates. The terms log(TM4/TM2) and (TM4/TM5) produced the maximum predictability for leaf area and dry green leaf weight, respectively. The middle infrared bands TM5 and TM7 are essential for maximizing predictability for all measured plant parameters except leaf area index. The estimating models were evaluated over bare soil to discriminate between equations which are statistically similar. Qualitative interpretations of the resulting prediction equations are consistent with general agronomic and remote sensing theory.

  9. Analytical Methods for Characterizing Magnetic Resonance Probes

    PubMed Central

    Manus, Lisa M.; Strauch, Renee C.; Hung, Andy H.; Eckermann, Amanda L.; Meade, Thomas J.

    2012-01-01

    SUMMARY The efficiency of Gd(III) contrast agents in magnetic resonance image enhancement is governed by a set of tunable structural parameters. Understanding and measuring these parameters requires specific analytical techniques. This Feature describes strategies to optimize each of the critical Gd(III) relaxation parameters for molecular imaging applications and the methods employed for their evaluation. PMID:22624599

  10. Large-scale biomedical concept recognition: an evaluation of current automatic annotators and their parameters

    PubMed Central

    2014-01-01

    Background Ontological concepts are useful for many different biomedical tasks. Concepts are difficult to recognize in text due to a disconnect between what is captured in an ontology and how the concepts are expressed in text. There are many recognizers for specific ontologies, but a general approach for concept recognition is an open problem. Results Three dictionary-based systems (MetaMap, NCBO Annotator, and ConceptMapper) are evaluated on eight biomedical ontologies in the Colorado Richly Annotated Full-Text (CRAFT) Corpus. Over 1,000 parameter combinations are examined, and best-performing parameters for each system-ontology pair are presented. Conclusions Baselines for concept recognition by three systems on eight biomedical ontologies are established (F-measures range from 0.14–0.83). Out of the three systems we tested, ConceptMapper is generally the best-performing system; it produces the highest F-measure of seven out of eight ontologies. Default parameters are not ideal for most systems on most ontologies; by changing parameters F-measure can be increased by up to 0.4. Not only are best performing parameters presented, but suggestions for choosing the best parameters based on ontology characteristics are presented. PMID:24571547

  11. Reference range evaluation of complete blood count parameters with emphasis on newer research parameters on the complete blood count analyzer Sysmex XE-2100.

    PubMed

    Sehgal, Kunal K; Tina, Dadu; Choksey, Urmi; Dalal, Reeta J; Shanaz, Khodaiji J

    2013-01-01

    Since the advent of automation in the field of hematological cell counters there has been a constant refinement of the technology and increase in the number of newer parameters available on CBC analysers. Many novel parameters are being put into routine clinical use and both clinical evaluation and monitoring critically depend on knowledge of laboratory reference ranges. Here, we present reference interval for the Sysmex XE-2100, with emphasis on the novel or newer research parameters. Blood samples from a total of 122 clinically asymptomatic and apparently healthy subjects were evaluated and a final of 100 subjects (54-M, 46-F) were included in the study. A broad spectrum of parameters available with the analyser was assessed and reference ranges for the same evaluated. PMID:24056647

  12. Use of Electron Paramagnetic Resonance Spectroscopy to Evaluate the Redox State In Vivo

    PubMed Central

    SWARTZ, HAROLD M.; KHAN, NADEEM; KHRAMTSOV, VALERY V.

    2009-01-01

    The aim of this article is to provide an overview of how electron paramagnetic resonance (EPR) can be used to measure redox-related parameters in vivo. The values of this approach include that the measurements are made under fully physiological conditions, and some of the measurements cannot be made by other means. Three complementary approaches are used with in vivo EPR: the rate of reduction or reactions of nitroxides, spin trapping of free radicals, and measurements of thiols. All three approaches already have produced unique and useful information. The measurement of the rate of decrease of nitroxides technically is the simplest, but difficult to interpret because the measured parameter, reduction in the intensity of the nitroxide signal, can occur by several different mechanisms. In vivo spin trapping can provide direct evidence for the occurrence of specific free radicals in vivo and reflect relative changes, but accurate absolute quantification remains challenging. The measurement of thiols in vivo also appears likely to be useful, but its development as an in vivo technique is at an early stage. It seems likely that the use of in vivo EPR to measure redox processes will become an increasingly utilized and valuable tool. PMID:17678441

  13. A preliminary evaluation of an F100 engine parameter estimation process using flight data

    NASA Technical Reports Server (NTRS)

    Maine, Trindel A.; Gilyard, Glenn B.; Lambert, Heather H.

    1990-01-01

    The parameter estimation algorithm developed for the F100 engine is described. The algorithm is a two-step process. The first step consists of a Kalman filter estimation of five deterioration parameters, which model the off-nominal behavior of the engine during flight. The second step is based on a simplified steady-state model of the compact engine model (CEM). In this step, the control vector in the CEM is augmented by the deterioration parameters estimated in the first step. The results of an evaluation made using flight data from the F-15 aircraft are presented, indicating that the algorithm can provide reasonable estimates of engine variables for an advanced propulsion control law development.

  14. A preliminary evaluation of an F100 engine parameter estimation process using flight data

    NASA Technical Reports Server (NTRS)

    Maine, Trindel A.; Gilyard, Glenn B.; Lambert, Heather H.

    1990-01-01

    The parameter estimation algorithm developed for the F100 engine is described. The algorithm is a two-step process. The first step consists of a Kalman filter estimation of five deterioration parameters, which model the off-nominal behavior of the engine during flight. The second step is based on a simplified steady-state model of the 'compact engine model' (CEM). In this step the control vector in the CEM is augmented by the deterioration parameters estimated in the first step. The results of an evaluation made using flight data from the F-15 aircraft are presented, indicating that the algorithm can provide reasonable estimates of engine variables for an advanced propulsion-control-law development.

  15. Monte Carlo evaluation of biological variation: Random generation of correlated non-Gaussian model parameters

    NASA Astrophysics Data System (ADS)

    Hertog, Maarten L. A. T. M.; Scheerlinck, Nico; Nicolaï, Bart M.

    2009-01-01

    When modelling the behaviour of horticultural products, demonstrating large sources of biological variation, we often run into the issue of non-Gaussian distributed model parameters. This work presents an algorithm to reproduce such correlated non-Gaussian model parameters for use with Monte Carlo simulations. The algorithm works around the problem of non-Gaussian distributions by transforming the observed non-Gaussian probability distributions using a proposed SKN-distribution function before applying the covariance decomposition algorithm to generate Gaussian random co-varying parameter sets. The proposed SKN-distribution function is based on the standard Gaussian distribution function and can exhibit different degrees of both skewness and kurtosis. This technique is demonstrated using a case study on modelling the ripening of tomato fruit evaluating the propagation of biological variation with time.

  16. Evaluation and optimization of the structural parameter of diesel nozzle basing on synchrotron radiation imaging techniques

    NASA Astrophysics Data System (ADS)

    Wu, Z.; Gao, Y.; Gong, H.; Li, L.

    2016-04-01

    Lacking of efficient methods, industry currently uses one only parameter—fuel flow rate—to evaluate the nozzle quality, which is far from satisfying the current emission regulations worldwide. By utilizing synchrotron radiation high energy X-ray in Shanghai Synchrotron Radiation Facility (SSRF), together with the imaging techniques, the 3D models of two nozzles with the same design dimensions were established, and the influence of parameters fluctuation in the azimuthal direction were analyzed in detail. Results indicate that, due to the orifice misalignment, even with the same design dimension, the inlet rounding radius of orifices differs greatly, and its fluctuation in azimuthal direction is also large. This difference will cause variation in the flow characteristics at orifice outlet and then further affect the spray characteristics. The study also indicates that, more precise investigation and insight into the evaluation and optimization of diesel nozzle structural parameter are needed.

  17. A parameter estimation algorithm for spatial sine testing - Theory and evaluation

    NASA Technical Reports Server (NTRS)

    Rost, R. W.; Deblauwe, F.

    1992-01-01

    This paper presents the theory and an evaluation of a spatial sine testing parameter estimation algorithm that uses directly the measured forced mode of vibration and the measured force vector. The parameter estimation algorithm uses an ARMA model and a recursive QR algorithm is applied for data reduction. In this first evaluation, the algorithm has been applied to a frequency response matrix (which is a particular set of forced mode of vibration) using a sliding frequency window. The objective of the sliding frequency window is to execute the analysis simultaneously with the data acquisition. Since the pole values and the modal density are obtained from this analysis during the acquisition, the analysis information can be used to help determine the forcing vectors during the experimental data acquisition.

  18. Analysis and Experimental Evaluation of Power Line Transmission Parameters for Power Line Communication

    NASA Astrophysics Data System (ADS)

    Mlynek, P.; Misurec, J.; Koutny, M.; Fujdiak, R.; Jedlicka, T.

    2015-04-01

    The article describes a way of evaluating the power line channel frequency response and input impedance by means of the linear time-invariant (LTI) power line generator. Two possible methods are introduced for the calculation of primary parameters: the first method depends on the physical realization and physical dimension of the cable, and the second method is derived from the data provided by typical electrical cable manufacturers. Based on these methods, a comparison of transfer functions was made. This is followed by measurement evaluation and numerical verification on a simple topology

  19. New parameters for a better evaluation of vegetative bioremediation, leaching, and phytodesalination.

    PubMed

    Rabhi, Mokded; Atia, Abdallah; Abdelly, Chedly; Smaoui, Abderrazak

    2015-10-21

    Vegetative bioremediation of calcareous sodic and saline-sodic soils is a biological approach for soil desalination by plants. It is based on three main processes: (i) sodium release from cation exchange sites, (ii) its leaching, and/or (iii) phytodesalination (Na(+) uptake by plant roots and its accumulation in shoots). Leaching needs sufficient rainfall and/or adequate irrigation. Thus, under non-leaching conditions, phytodesalination is the only existing process in terms of sodium removal. Several works tried to evaluate these processes; used plants were grown in field, in lysimeters, or in non-perforated pots. The evaluation of vegetative bioremediation, leaching, and phytodesalination was mainly based on plant analyses (including biomass production, sodium accumulation, test culture, and co-culture) and soil analyses (porosity, salinity, sodicity...). Nevertheless, used parameters are not enough to ensure comparisons between results found in different investigations. The present study introduces new parameters like phytodesalination efficiency, yield, and rate as well as vegetative bioremediation and leaching yields and rates. Our study is also illustrated by an estimation of all parameters for several previously-published data from our own works and those of other authors. Obtained results showed usefulness of these parameters and some of them can be extended to heavy metal phytoexraction. PMID:26254216

  20. New parameters for a better evaluation of vegetative bioremediation, leaching, and phytodesalination.

    PubMed

    Rabhi, Mokded; Atia, Abdallah; Abdelly, Chedly; Smaoui, Abderrazak

    2015-10-21

    Vegetative bioremediation of calcareous sodic and saline-sodic soils is a biological approach for soil desalination by plants. It is based on three main processes: (i) sodium release from cation exchange sites, (ii) its leaching, and/or (iii) phytodesalination (Na(+) uptake by plant roots and its accumulation in shoots). Leaching needs sufficient rainfall and/or adequate irrigation. Thus, under non-leaching conditions, phytodesalination is the only existing process in terms of sodium removal. Several works tried to evaluate these processes; used plants were grown in field, in lysimeters, or in non-perforated pots. The evaluation of vegetative bioremediation, leaching, and phytodesalination was mainly based on plant analyses (including biomass production, sodium accumulation, test culture, and co-culture) and soil analyses (porosity, salinity, sodicity...). Nevertheless, used parameters are not enough to ensure comparisons between results found in different investigations. The present study introduces new parameters like phytodesalination efficiency, yield, and rate as well as vegetative bioremediation and leaching yields and rates. Our study is also illustrated by an estimation of all parameters for several previously-published data from our own works and those of other authors. Obtained results showed usefulness of these parameters and some of them can be extended to heavy metal phytoexraction.

  1. Temperature evaluation of traveling-wave ultrasonic motor considering interaction between temperature rise and motor parameters.

    PubMed

    Li, Shiyang; Ou, Wenchu; Yang, Ming; Guo, Chao; Lu, Cunyue; Hu, Junhui

    2015-03-01

    In this paper, a novel model for evaluating the temperature of traveling-wave ultrasonic motor (TWUSM) is developed. The proposed model, where the interaction between the temperature rise and motor parameters is considered, differs from the previous reported models with constant parameters. In this model, losses and temperature rises of the motor were evaluated based on the temperature-related varying parameters: the feedback voltage Vaux of the stator, dielectric permittivity ɛ and dielectric loss factor tanδ. At each new temperature, Vaux, ɛ and tanδ were updated. The feasibility and effectiveness of this proposed model was verified by comparing the predicted temperatures with the measured one. The effects of driving voltage, driving frequency and ambient temperature on the predicted temperature were also analyzed. The results show that the proposed model has more accurate predicted temperature than that with constant parameters. This will be very useful for the optimal design, reducing the heat loss, improvement of control and reliability life of TWUSM.

  2. Evaluation of kinetic parameters for water soluble crystals by thermo gravimetric analysis

    NASA Astrophysics Data System (ADS)

    Rama, S.; Surendra Dilip, C.; Perumal, Rajesh Narayana

    2015-01-01

    This work elevates the relevance of kinetic parameters of nucleation and thermal decomposition for water soluble crystals. The positive soluble Potassium Dihydrogen Phosphate (KDP) and negative soluble Lithium Sulfate Monohydrate (LSMH) materials were chosen for the kinetic evaluation. The results obtained from the classical nucleation theory are verified with the kinetic parameters which are evaluated from thermo gravimetric analysis. Nucleation parameters of a crystallization process such as interfacial energy (σ), volume free energy (ΔGv), critical energy barrier for nucleation (ΔG*), radius of the critical nucleus (r*) and nucleation rate (J) of the positive (KDP) and negative solubility (LSMH) crystals are determined from the classical nucleation theory of solubility-enthalpy relation. The kinetic parameters viz. the order of reaction, enthalpy, Gibbs free energy of activation, frequency factor, and entropy of activation are obtained from the TG based models viz. Horowitz-Metzger, Coats-Redfern and Piloyan-Novikova. The effect of varying temperature with relative variation on Gibbs free energy for both positive and negative solubility crystals is also discussed. The developed model holds good for both positive and negative solubility crystals.

  3. Effects of chiral fragrances on human autonomic nervous system parameters and self-evaluation.

    PubMed

    Heuberger, E; Hongratanaworakit, T; Böhm, C; Weber, R; Buchbauer, G

    2001-03-01

    The effects of chiral fragrances (enantiomers of limonene and carvone) on the human autonomic nervous system (ANS) and on self-evaluation were studied in 20 healthy volunteers. Each fragrance was administered to each subject by inhalation using an A-A-B design. Individuals were tested in four separate sessions; in one session one fragrance was administered. ANS parameters recorded were skin temperature, skin conductance, breathing rate, pulse rate, blood oxygen saturation and systolic as well as diastolic blood pressure. Subjective experience was assessed in terms of mood, calmness and alertness on visual analog scales. In addition, fragrances were rated in terms of pleasantness, intensity and stimulating property. Inhalation of (+)-limonene led to increased systolic blood pressure, subjective alertness and restlessness. Inhalation of (-)-limonene caused an increase in systolic blood pressure but had no effects on psychological parameters. Inhalation of (-)-carvone caused increases in pulse rate, diastolic blood pressure and subjective restlessness. After inhalation of (+)-carvone increased levels of systolic as well as diastolic blood pressure were observed. Correlational analyses revealed that changes in both ANS parameters and self-evaluation were in part related to subjective evaluation of the odor and suggest that both pharmacological and psychological mechanisms are involved in the observed effects. In conclusion, the present study indicates that: (i) prolonged inhalation of fragrances influences ANS parameters as well as mental and emotional conditions; (ii) effects of fragrances are in part based on subjective evaluation of odor; (iii) chirality of odor molecules seems to be a central factor with respect to the biological activity of fragrances.

  4. An information-measuring system for evaluating performance parameters of lighting devices

    NASA Astrophysics Data System (ADS)

    Abulkhanov, Stanislav R.; Kharitonov, Sergey I.

    2016-04-01

    We propose the design of an information-measuring system for evaluating performance parameters of lighting devices. The system comprises four basic components: a software-hardware complex for designing lighting devices, an emulator of natural and technogeneous effects on an optical surface, an optical surface condition analyzer, and a lighting-device laboratory test unit. With this system, the duration of optical device certification tests can be reduced by several orders of magnitude when compared to full-scale tests.

  5. Evaluation of Lauha bhasma on classical analytical parameters - A pilot study.

    PubMed

    Sarkar, Prasanta Kumar; Choudhary, A K; Prajapati, P K

    2008-01-01

    Lauha Bhasma is the most widely used bhasma preparation in therapeutics, but till date the temperature pattern to prepare Lauha Bhasma in electric muffle furnace is not fixed. So in this pilot study an attempt has been made to confirm the appropriate temperature pattern to prepare Lauha Bhasma. And emphasis has been given to evaluate this prepared Lauha Bhasma on classical analytical parameter, which reflects the physical and chemical properties of the Bhasma. PMID:22557274

  6. Evaluation of Lauha bhasma on classical analytical parameters – A pilot study

    PubMed Central

    Sarkar, Prasanta Kumar; Choudhary, A. K.; Prajapati, P. K.

    2008-01-01

    Lauha Bhasma is the most widely used bhasma preparation in therapeutics, but till date the temperature pattern to prepare Lauha Bhasma in electric muffle furnace is not fixed. So in this pilot study an attempt has been made to confirm the appropriate temperature pattern to prepare Lauha Bhasma. And emphasis has been given to evaluate this prepared Lauha Bhasma on classical analytical parameter, which reflects the physical and chemical properties of the Bhasma. PMID:22557274

  7. [Nuclear magnetic resonance based metabolic phenotyping for patient evaluations in operating rooms and intensive care units].

    PubMed

    Blaise, B J; Gouel-Chéron, A; Floccard, B; Monneret, G; Plaisant, F; Chassard, D; Javouhey, E; Claris, O; Allaouchiche, B

    2014-03-01

    Metabolic phenotyping consists in the identification of subtle and coordinated metabolic variations associated with various pathophysiological stimuli. Different analytical methods, such as nuclear magnetic resonance, allow the simultaneous quantification of a large number of metabolites. Statistical analyses of these spectra thus lead to the discrimination between samples and the identification of a metabolic phenotype corresponding to the effect under study. This approach allows the extraction of candidate biomarkers and the recovery of perturbed metabolic networks, driving to the generation of biochemical hypotheses (pathophysiological mechanisms, diagnostic tests, therapeutic targets…). Metabolic phenotyping could be useful in anaesthesiology and intensive care medicine for the evaluation, monitoring or diagnosis of life-threatening situations, to optimise patient managements. This review introduces the physical and statistical fundamentals of NMR-based metabolic phenotyping, describes the work already achieved by this approach in anaesthesiology and intensive care medicine. Finally, potential areas of interest are discussed for the perioperative and intensive management of patients, from newborns to adults.

  8. Hepatic hemangiomas: evaluation by magnetic resonance imaging and technetium-99m red blood cell scintigraphy

    SciTech Connect

    Brown, R.K.; Gomes, A.; King, W.; Pusey, E.; Lois, J.; Goldstein, L.; Busuttil, R.W.; Hawkins, R.A.

    1987-11-01

    A study was performed to evaluate and compare the sensitivity of magnetic resonance imaging (MRI) and radionuclide blood-pool scanning in the detection of hepatic hemangiomas. All patients had known hemangiomas which were first detected on either ultrasound or computed tomography. Sixteen patients with a total of 23 lesions were investigated. Eleven patients had both MRI and blood-pool scans performed. In the group studied by both modalities, 18 lesions were detected ranging in size from 1 to 11 cm. All lesions were detected by both techniques. However, two of the 18 lesions had an atypical appearance on MRI. Our experience to date indicates that the anatomic location and specific diagnosis of hemangiomas can be made with a high degree of certainty when both MRI and blood-pool scanning techniques are utilized.

  9. Assessment of cardiac parameters in evaluation of cardiac functions in patients with thalassemia major.

    PubMed

    Oztarhan, Kazim; Delibas, Yavuz; Salcioglu, Zafer; Kaya, Guldemet; Bakari, Suleyman; Bornaun, Helen; Aydogan, Gonul

    2012-04-01

    The aim of the study was to evaluate cardiac function and early cardiac dysfunction of patients followed as thalassemia major. In this study, the authors compared 100 patients, diagnosed as thalassemia major with mean age 11.84 ± 4.35, with 60 healthy control subjects at the same age between 2008 and 2011. Early diagnosis of iron overload that may occur after repeated transfusions is important in this patient group. To detect early iron accumulation, the authors compared ferritin with the echo findings, the 24-hour Holter, and cardiac magnetic resonance imaging (MRI) T2* values in the patients of same age and sex, treated with chelators, without heart failure, nonsplenectomized, and do not differ in the presence of hepatitis C. Ferritin levels, left ventricular systolic functions (ejection fraction [EF], shortening fraction [SF]), left ventricular measurements, left ventricular diastolic functions, T2* image on cardiac magnetic resonance, heart rate variables in 24 hours, and Holter rhythm were evaluated to show the early failure of cardiac functions. In this study the authors confirmed that iron-related cardiac toxicity damages electrical activity earlier than myocardial contractility. Left ventricular diastolic diameter (LVDd), left ventricular mass (LVM), and LV systolic diameter (LVDs) levels were significantly higher in the patient group with ectopia. Patients with ectopia are the ones in whom LVM and LVDd are increased. In thalassemia major patients with ectopia, LF/HF ratio was markedly increased, QTc dispersion was clearly found higher in patients with ectopia rather than nonectopic patients. The standard deviation all normal RR interval series (SDNN) was found clearly lower in thalassemia major group with ectopia than control group because it is assumed that increase in cardiac sympathetic neuronal activity is related to exposure to chronic diastolic and systolic failure.

  10. Subsonic flight test evaluation of a propulsion system parameter estimation process for the F100 engine

    NASA Technical Reports Server (NTRS)

    Orme, John S.; Gilyard, Glenn B.

    1992-01-01

    Integrated engine-airframe optimal control technology may significantly improve aircraft performance. This technology requires a reliable and accurate parameter estimator to predict unmeasured variables. To develop this technology base, NASA Dryden Flight Research Facility (Edwards, CA), McDonnell Aircraft Company (St. Louis, MO), and Pratt & Whitney (West Palm Beach, FL) have developed and flight-tested an adaptive performance seeking control system which optimizes the quasi-steady-state performance of the F-15 propulsion system. This paper presents flight and ground test evaluations of the propulsion system parameter estimation process used by the performance seeking control system. The estimator consists of a compact propulsion system model and an extended Kalman filter. The extended Laman filter estimates five engine component deviation parameters from measured inputs. The compact model uses measurements and Kalman-filter estimates as inputs to predict unmeasured propulsion parameters such as net propulsive force and fan stall margin. The ability to track trends and estimate absolute values of propulsion system parameters was demonstrated. For example, thrust stand results show a good correlation, especially in trends, between the performance seeking control estimated and measured thrust.

  11. Evaluation of unconfined-aquifer parameters from pumping test data by nonlinear least squares

    USGS Publications Warehouse

    Heidari, M.; Moench, A.

    1997-01-01

    Nonlinear least squares (NLS) with automatic differentiation was used to estimate aquifer parameters from drawdown data obtained from published pumping tests conducted in homogeneous, water-table aquifers. The method is based on a technique that seeks to minimize the squares of residuals between observed and calculated drawdown subject to bounds that are placed on the parameter of interest. The analytical model developed by Neuman for flow to a partially penetrating well of infinitesimal diameter situated in an infinite, homogeneous and anisotropic aquifer was used to obtain calculated drawdown. NLS was first applied to synthetic drawdown data from a hypothetical but realistic aquifer to demonstrate that the relevant hydraulic parameters (storativity, specific yield, and horizontal and vertical hydraulic conductivity) can be evaluated accurately. Next the method was used to estimate the parameters at three field sites with widely varying hydraulic properties. NLS produced unbiased estimates of the aquifer parameters that are close to the estimates obtained with the same data using a visual curve-matching approach. Small differences in the estimates are a consequence of subjective interpretation introduced in the visual approach.

  12. Evaluation of Net Infiltration Uncertainty for Multiple Uncertain Input Parameters Using Latin Hypercube Sampling

    NASA Astrophysics Data System (ADS)

    Faybishenko, B.; McCurley, R. D.; Wang, J. Y.

    2004-12-01

    To assess, via numerical simulation, the effect of 12 uncertain input parameters (characterizing soil and rock properties and boundary [meteorological] conditions), on net infiltration uncertainty, the Latin Hypercube Sampling (LHS) technique (a modified Monte Carlo approach using a form of stratified sampling) was used. Each uncertain input parameter is presented using a probability distribution function, characterizing the epistemic uncertainty (which arises from the lack of knowledge about parameters-an uncertainty that can be reduced as new information becomes available). One hundred LHS realizations (using the code LHS V2.50 developed at Sandia National Laboratories) of the uncertain input parameters were used to simulate the net infiltration over the Yucca Mountain repository footprint. Simulations were carried out using the code INFIL VA-2.a1 (a modified USGS code INFIL V2.0). The results of simulations were then used to determine the net infiltration probability distribution function. According to theoretical considerations, for 12 uncertain input parameters, from 15 to 36 realizations using the LHS technique should be sufficient to get meaningful results. In this presentation, we will show that the theoretical considerations may significantly underestimate the required number of realizations for the evaluation of the correlation between the net infiltration and uncertain input parameters. We will demonstrate that the calculated net infiltration rate (presented as a probability distribution function) oscillates as a function of simulation runs, and that the correlation between net infiltration rate and the uncertain input parameters depends on the number of simulation runs. For example, the correlation coefficient between the soil (or rock) permeability and net infiltration stabilizes only after 60-80 realizations. The results of the correlation analysis show that the correlation to net infiltration is highest for precipitation, bedrock permeability

  13. Anatomic and Functional Evaluation of Central Lymphatics With Noninvasive Magnetic Resonance Lymphangiography

    PubMed Central

    Kim, Eun Young; Hwang, Hye Sun; Lee, Ho Yun; Cho, Jong Ho; Kim, Hong Kwan; Lee, Kyung Soo; Shim, Young Mog; Zo, Jaeil

    2016-01-01

    Abstract Accurate assessment of the lymphatic system has been limited due to the lack of optimal diagnostic methods. Recently, we adopted noncontrast magnetic resonance (MR) lymphangiography to evaluate the central lymphatic channel. We aimed to investigate the feasibility and the clinical usefulness of noninvasive MR lymphangiography for determining lymphatic disease. Ten patients (age range 42–72 years) with suspected chylothorax (n = 7) or lymphangioma (n = 3) who underwent MR lymphangiography were included in this prospective study. The thoracic duct was evaluated using coronal and axial images of heavily T2-weighted sequences, and reconstructed maximum intensity projection. Two radiologists documented visualization of the thoracic duct from the level of the diaphragm to the thoracic duct outlet, and also an area of dispersion around the chyloma or direct continuity between the thoracic duct and mediastinal cystic mass. The entire thoracic duct was successfully delineated in all patients. Lymphangiographic findings played a critical role in identifying leakage sites in cases of postoperative chylothorax, and contributed to differential diagnosis and confirmation of continuity with the thoracic duct in cases of lymphangioma, and also in diagnosing Gorham disease, which is a rare disorder. In patients who underwent surgery, intraoperative findings were matched with lymphangiographic imaging findings. Nonenhanced MR lymphangiography is a safe and effective method for imaging the central lymphatic system, and can contribute to differential diagnosis and appropriate preoperative evaluation of pathologic lymphatic problems. PMID:27015184

  14. Anatomic and Functional Evaluation of Central Lymphatics With Noninvasive Magnetic Resonance Lymphangiography.

    PubMed

    Kim, Eun Young; Hwang, Hye Sun; Lee, Ho Yun; Cho, Jong Ho; Kim, Hong Kwan; Lee, Kyung Soo; Shim, Young Mog; Zo, Jaeil

    2016-03-01

    Accurate assessment of the lymphatic system has been limited due to the lack of optimal diagnostic methods. Recently, we adopted noncontrast magnetic resonance (MR) lymphangiography to evaluate the central lymphatic channel. We aimed to investigate the feasibility and the clinical usefulness of noninvasive MR lymphangiography for determining lymphatic disease.Ten patients (age range 42-72 years) with suspected chylothorax (n = 7) or lymphangioma (n = 3) who underwent MR lymphangiography were included in this prospective study. The thoracic duct was evaluated using coronal and axial images of heavily T2-weighted sequences, and reconstructed maximum intensity projection. Two radiologists documented visualization of the thoracic duct from the level of the diaphragm to the thoracic duct outlet, and also an area of dispersion around the chyloma or direct continuity between the thoracic duct and mediastinal cystic mass.The entire thoracic duct was successfully delineated in all patients. Lymphangiographic findings played a critical role in identifying leakage sites in cases of postoperative chylothorax, and contributed to differential diagnosis and confirmation of continuity with the thoracic duct in cases of lymphangioma, and also in diagnosing Gorham disease, which is a rare disorder. In patients who underwent surgery, intraoperative findings were matched with lymphangiographic imaging findings.Nonenhanced MR lymphangiography is a safe and effective method for imaging the central lymphatic system, and can contribute to differential diagnosis and appropriate preoperative evaluation of pathologic lymphatic problems. PMID:27015184

  15. Thermodynamic parameters for the binding of divalent cations to gramicidin A incorporated into a lipid environment by Tl-205 nuclear magnetic resonance.

    PubMed Central

    Hinton, J F; Fernandez, J Q; Shungu, D C; Millett, F S

    1989-01-01

    Thermodynamic parameters, enthalpy and entropy, for the binding of the divalent cations, Mg+2, Ca+2, Sr+2, Ba+2, and Cd+2, to gramicidin A, incorporated into lysophosphatidylcholine, have been determined using a combination of Tl-205 nuclear magnetic resonance spectroscopy and competition binding. The binding process is thermodynamically driven by the enthalpy and not the entropy. The enthalpy values are related to the process involving the transfer of cations from an aqueous environment to an amide environment. A comparison is made between the thermodynamic parameters for the binding of monovalent and divalent cations to gramicidin A to illustrate the channel blocking ability of the divalent cations with respect to monovalent cation transport. PMID:2469486

  16. Correlation of magnetic resonance signal characteristics and perfusion parameters assessed by volume perfusion computed tomography in hepatocellular carcinoma: Impact on lesion characterization

    PubMed Central

    Grözinger, Gerd; Bitzer, Michael; Syha, Roland; Ketelsen, Dominik; Nikolaou, Konstantin; Lauer, Ulrich; Horger, Marius

    2016-01-01

    AIM To find out if magnetic resonance (MR)-signal characteristics of hepatocellular carcinomas (HCC) correlate with perfusion parameters assessed by volume perfusion computed tomography (VPCT). METHODS From October 2009 to January 2014, 26 (mean age, 69.3 years) patients with 36 HCC lesions who underwent both VPCT and MR liver imaging were analysed. We compared signal intensity in the T1w- and T2w-images and wash-in/wash-out kinetics on post-contrast MR images with mean values of blood flow (BF, mL/100 mL per minute), blood volume (BV, mL/100 mL), k-trans (mL/100 mL per minute), arterial liver perfusion (mL/100 mL per minute), portal venous perfusion and hepatic perfusion index (HPI, %) obtained by VPCT. Signal intensity on magnetic resonance imaging (MRI) was classified hyper/iso/hypointense compared with surrounding liver parenchyma. RESULTS Signal intensity on native T1w- and T2w-images was hyper/iso/hypo in 4/16/16 and 21/14/1 lesions, respectively. Wash-in and wash-out contrast kinetics were found on MRI in 33 of 36 lesions (91.7%) and 25 of 36 lesions (69.4%), respectively. The latter was observed significantly more often in higher graded lesions (P < 0.005). HPI was 94.7% ± 6.5%. There was no significant relationship between lesion’s MR-signal intensity, MR signal combinations, size and any of the VPCT-perfusion parameters. However HPI was constantly high in all HCC lesions. CONCLUSION VPCT parameters add limited value to MR-lesion characterization. However in HCC lesions with atypical MR signal characteristics HPI can add a parameter to ensure HCC diagnosis. PMID:27551338

  17. Evaluation of shoulder balance in the normal adolescent population and its correlation with radiological parameters.

    PubMed

    Akel, Ibrahim; Pekmezci, Murat; Hayran, Mutlu; Genc, Yasemin; Kocak, Ozgur; Derman, Orhan; Erdoğan, Ilkay; Yazici, Muharrem

    2008-03-01

    A descriptive clinical study in healthy adolescents was done to evaluate the clinical shoulder balance and analyze the correlation between clinical and radiological parameters which are currently used to evaluate shoulder balance. In addition to trunk shift and rib hump, shoulder balance is one of the criteria that are used to evaluate the outcomes in spinal deformity surgery. Several methods have been proposed to evaluate the shoulder balance in scoliotic patients; however, there is no uniformity to these methods in the current literature. Patients who applied to pediatric clinic without musculoskeletal pathology formed the patient population. Volunteers were asked to fill out a questionnaire assessing shoulder balance perception and had their clinical photograph taken simultaneously with a P-A chest X-ray. The clinical shoulder balance was evaluated through analysis of the clinical photograph. The X-rays were used to evaluate the radiological shoulder balance. The evaluated parameters included coracoid height difference (CHD), clavicular angle (CA), the clavicle-rib cage intersection difference (CRID), clavicular tilt angle difference (CTAD), and T1-tilt. The study group was composed of 48 male and 43 female patients with an average age of 13.6 +/- 2.1 (10-18) years. In the questionnaire, all patients stated that their shoulders were level. The digital photographs revealed that only 17(18.7%) adolescents had absolutely level shoulders. The average height difference between shoulders was 7.5 +/- 5.8 mm. The average CHD was 6.9 +/- 5.8 mm, average CA was 2.2 +/- 1.7 degrees , average CRID was 4.8 +/- 3.6 mm, average CTAD was 4 +/- 3.2 degrees , and average T1-tilt was 1.3 +/- 1.4 degrees . CHD, CA, and CRID demonstrated high correlation with clinical pictures, whereas CTAD demonstrated moderate and T1-tilt demonstrated only mild correlation. The radiological parameters used to evaluate the shoulder balance correlate with the clinical appearance. Contrary to popular

  18. Lineshape of {psi}(3770) and low-lying vector charmonium resonance parameters in e{sup +}e{sup -{yields}}DD

    SciTech Connect

    Zhang Yuanjiang; Zhao Qiang

    2010-02-01

    We investigate the DD production in e{sup +}e{sup -} annihilations near threshold in an effective Lagrangian approach. This shows that the lineshape of the cross section near threshold is sensitive to the contributions from {psi}{sup '}, though it is below the DD threshold. The recent experimental data from the BES and Belle collaborations allow us to determine the {psi}{sup '}DD coupling constant, which appears to be consistent with other theoretical studies. As a consequence, the {psi}{sup '}-{psi}(3770) mixing parameter can be extracted around the {psi}(3770) mass region. Resonance parameters for {psi}(3770), X(3900), {psi}(4040), and {psi}(4160) are also investigated. The X(3900) appears as an enhancement at around 3.9 GeV in the Belle data. In addition to treating it as a resonance, we also study the mechanism through which the enhancement is produced by the DD*+c.c. open channel effects. Our result shows that such a possibility cannot be eliminated.

  19. Measurement and calculation of the Stark-broadening parameters for the resonance lines of singly ionized calcium and magnesium.

    NASA Technical Reports Server (NTRS)

    Jones, W. W.; Sanchez, A.; Greig, J. R.; Griem, H. R.

    1972-01-01

    The electron-impact-broadened profiles of the resonance lines of singly ionized calcium and magnesium have been measured using an electromagnetically driven shock tube and a rapid-scanning Fabry-Perot spectrometer. For an electron density of 10 to the 17th power per cu cm and a temperature of 19,000 K, we found the Lorentzian half-width of the Ca+ line to be 0.086 A plus or minus 10% and of the Mg+ line to be 0.044 A plus or minus 10%. Using the quantum-mechanical theory of Barnes and Peach and our semiclassical calculation for the calcium lines, we found that the temperature dependence of the theoretical curves is close to that measured, although both theories predict actual values which are somewhat large.

  20. Predictive parameters for medical expulsive therapy in ureteral stones: a critical evaluation.

    PubMed

    Sahin, Cahit; Eryildirim, Bilal; Kafkasli, Alper; Coskun, Alper; Tarhan, Fatih; Faydaci, Gokhan; Sarica, Kemal

    2015-06-01

    To evaluate the predictive value of some certain radiological as well as stone-related parameters for medical expulsive therapy (MET) success with an alpha blocker in ureteral stones. A total 129 patients receiving MET for 5 to 10 mm ureteral stones were evaluated. Patients were divided into two subgroups where MET was successful in 64 cases (49.61%) and unsuccessful in 65 cases (50.39%). Prior to management, stone size, location, position in the ureter, degree of hydronephrosis, diameter of ureteral lumen proximal to the stone, ureteral wall thickness along with patient's demographics including body mass index (BMI) values were evaluated and recorded. The possible predictive values of these parameters for stone expulsion (and stone expulsion time) were evaluated in a comparative manner between two groups. The overall mean patient age and stone size values were 38.02 ± 0.94 years and 40.31 ± 1.13 mm(2), respectively. Regarding the predictive values of these parameters for MET-success, while stone size and localization, degree of hydronephrosis, proximal ureteral diameter and ureteral wall thickness were found to be highly predictive for MET-success, patients age, BMI values and stone density had no predictive value on this aspect. Our findings indicated that some stone and anatomical factors may be used to predict the success of MET in an effective manner. With this approach unnecessary use of these drugs that may cause a delay for stone removal will be avoided and the possible adverse effects of obstruction as well as stone-related clinical symptoms could be minimized.

  1. Using experimental design to evaluate processing parameters in soft ferrite manufacture

    SciTech Connect

    Taylor, J.A.T.; Reczek, S.T.; Rosen, A.

    1995-09-01

    The manufacture of soft ferrites is a complex process that involves multitudinous, interrelated steps. Seldom can one variable, such as the effect of the particle size of a raw material, be evaluated without considering other parameters. The particle size of hematite, for example, may affect reaction rate during calcination and consequently the spinel formation. Spinel content affects hardness and is reflected in grinding time. Grinding time affects the amount of iron introduced from the milling media, and so on. To optimize a process, the primary effect of a parameter and the interactions of that affect with other variables should be evaluated. This can be accomplished by using an experimental design that maximizes the information that can be obtained from each set of samples. The purpose of this study was to investigate the impact of several processing parameters on the magnetic properties of MnZn spinels. An experimental design using an orthogonal array of three variables at two levels was used to examine sintering time, atmosphere containment and part size effects. Four and eight hours at the maximum firing temperature were used for this investigation. Atmosphere containment was achieved by covering saggers with shielding of the same composition as the cores. Size effects, which could result from surface to volume ratio differences, were addressed by comparing the data for large and small cores. The surface to volume ratio of small cores was 1.4 times that of large cores.

  2. Evaluation of multivariate linear regression and artificial neural networks in prediction of water quality parameters

    PubMed Central

    2014-01-01

    This paper examined the efficiency of multivariate linear regression (MLR) and artificial neural network (ANN) models in prediction of two major water quality parameters in a wastewater treatment plant. Biochemical oxygen demand (BOD) and chemical oxygen demand (COD) as well as indirect indicators of organic matters are representative parameters for sewer water quality. Performance of the ANN models was evaluated using coefficient of correlation (r), root mean square error (RMSE) and bias values. The computed values of BOD and COD by model, ANN method and regression analysis were in close agreement with their respective measured values. Results showed that the ANN performance model was better than the MLR model. Comparative indices of the optimized ANN with input values of temperature (T), pH, total suspended solid (TSS) and total suspended (TS) for prediction of BOD was RMSE = 25.1 mg/L, r = 0.83 and for prediction of COD was RMSE = 49.4 mg/L, r = 0.81. It was found that the ANN model could be employed successfully in estimating the BOD and COD in the inlet of wastewater biochemical treatment plants. Moreover, sensitive examination results showed that pH parameter have more effect on BOD and COD predicting to another parameters. Also, both implemented models have predicted BOD better than COD. PMID:24456676

  3. Evaluation of multivariate linear regression and artificial neural networks in prediction of water quality parameters.

    PubMed

    Zare Abyaneh, Hamid

    2014-01-01

    This paper examined the efficiency of multivariate linear regression (MLR) and artificial neural network (ANN) models in prediction of two major water quality parameters in a wastewater treatment plant. Biochemical oxygen demand (BOD) and chemical oxygen demand (COD) as well as indirect indicators of organic matters are representative parameters for sewer water quality. Performance of the ANN models was evaluated using coefficient of correlation (r), root mean square error (RMSE) and bias values. The computed values of BOD and COD by model, ANN method and regression analysis were in close agreement with their respective measured values. Results showed that the ANN performance model was better than the MLR model. Comparative indices of the optimized ANN with input values of temperature (T), pH, total suspended solid (TSS) and total suspended (TS) for prediction of BOD was RMSE = 25.1 mg/L, r = 0.83 and for prediction of COD was RMSE = 49.4 mg/L, r = 0.81. It was found that the ANN model could be employed successfully in estimating the BOD and COD in the inlet of wastewater biochemical treatment plants. Moreover, sensitive examination results showed that pH parameter have more effect on BOD and COD predicting to another parameters. Also, both implemented models have predicted BOD better than COD. PMID:24456676

  4. Evaluation of Coronal Shock Wave Velocities from the II Type Radio Bursts Parameters

    NASA Astrophysics Data System (ADS)

    Galanin, V. V.; Isaeva, E. A.; Kravetz, R. O.

    The work presents the results of research of connection between the coronal shock waves and the parameters of type II (mII) meter-decameter bursts in 25-180 MHz band for 66 solar proton events. The velocities of coronal shock waves for this two cases where determined. In the first case the velocities of the shock waves was evaluated according to the Newkirck model and in the second case - directly from the type II radio burst parameters. The calculated values of shock waves velocity was compared with the same velocity values that is published on NGDC site. The comparative analysis showed that precision of coronal shock waves velocity estimation which gets directly from type II radio bursts parameters was higher than the same one which used the Newkirck model. Research showed that there is exist the sufficiently strong connection between the shock wave velocity and the delay of type II burst intensity maximum on the second harmonica. Correlation coefficient between the studied parameters was equal to ≍ 0.65.

  5. Evaluation of multivariate linear regression and artificial neural networks in prediction of water quality parameters.

    PubMed

    Zare Abyaneh, Hamid

    2014-01-01

    This paper examined the efficiency of multivariate linear regression (MLR) and artificial neural network (ANN) models in prediction of two major water quality parameters in a wastewater treatment plant. Biochemical oxygen demand (BOD) and chemical oxygen demand (COD) as well as indirect indicators of organic matters are representative parameters for sewer water quality. Performance of the ANN models was evaluated using coefficient of correlation (r), root mean square error (RMSE) and bias values. The computed values of BOD and COD by model, ANN method and regression analysis were in close agreement with their respective measured values. Results showed that the ANN performance model was better than the MLR model. Comparative indices of the optimized ANN with input values of temperature (T), pH, total suspended solid (TSS) and total suspended (TS) for prediction of BOD was RMSE = 25.1 mg/L, r = 0.83 and for prediction of COD was RMSE = 49.4 mg/L, r = 0.81. It was found that the ANN model could be employed successfully in estimating the BOD and COD in the inlet of wastewater biochemical treatment plants. Moreover, sensitive examination results showed that pH parameter have more effect on BOD and COD predicting to another parameters. Also, both implemented models have predicted BOD better than COD.

  6. [Evaluation of inverse gas chromatography (IGC) methods to measure astragaloside solubility parameter from Buyang Huanwu decoction].

    PubMed

    Tang, Yu; Hu, Chao; Liao, Qiong; Liu, Wen-long; Yang, Yan-tao; He, Hong; He, Fu-yuan

    2015-01-01

    The solubility parameter determination of astrageloside from Buyang Huanwu decoction with inverse gas chromatography (IGC) method evaluation was investigated in this paper. Di-n-octyl phthalate Kwai alternative sample was used to carry out methodological study. The accuracy of the measured correlation coefficient was 0.992 1. Experimental precision measured by IGC experiments showed that the results were accurate and reliable. The sample was uniformly coated on the surface of an inert carrier and N2 gas was carrier gas, a variety of polar solvents such as isopropanol, toluene, acetone, chloroform, cyclohexane as probes. TCD detector temperature was 150 degrees C, gas room temperature was 120 degrees C. Similar headspace method was used whichever over 1 μL gas into the GC measurement, Retention time t(R), t(0) and all the parameters of air and probes molecules within the column were tested. Astragaloside solubility parameter was (21.02 ± 2.4) [J x cm(-3)] ½, literature value was 19.24 [J x cm(-3)] ½, and relevant coefficient was 0.984 5. IGC method is effective and accurate to measure ingredients solubility parameter. PMID:26080552

  7. Evaluation of Traumatic Spine by Magnetic Resonance Imaging and Correlation with Neurological Recovery

    PubMed Central

    Magu, Sarita; Yadav, Rohtas Kanwar; Bala, Manju

    2015-01-01

    Study Design Prospective study. Purpose To compare magnetic resonance imaging (MRI) findings with clinical profile and neurological status of the patient and to correlate the MRI findings with neurological recovery of the patients and predict the outcome. Overview of Literature Previous studies have reported poor neurological recovery in patients with cord hemorrhage, as compared to cord edema in spine injury patients. High canal compromise, cord compression along with higher extent of cord injury also carries poor prognostic value. Methods Neurological status of patients was assessed at the time of admission and discharge in as accordance with the American Spine Injury Association (ASIA) impairment scale. Mean stay in hospital was 14.11±5.74 days. Neurological status at admission and neurological recovery at discharge was compared with various qualitative cord findings and quantitative parameters on MRI. In 27 patients, long-term follow-up was done at mean time of 285.9±43.94 days comparing same parameters. Results Cord edema and normal cord was associated with favorable neurological outcome. Cord contusion showed lesser neurological recovery, as compared to cord edema. Cord hemorrhage was associated with worst neurological status at admission and poor neurological recovery. Mean canal compromise (MCC), mean spinal cord compression (MSCC) and lesion length values were higher in patients presenting with ASIA A impairment scale injury and showed decreasing trends towards ASIA E impairment scale injury. Patients showing neurological recovery had lower mean MCC, MSCC, and lesion length, as compared to patients showing no neurological recovery (p<0.05). Conclusions Cord hemorrhage, higher MCC, MSCC, and lesion length values have poor prognostic value in spine injury patients. PMID:26435794

  8. Pineapple juice as a negative oral contrast agent in magnetic resonance cholangiopancreatography: a preliminary evaluation.

    PubMed

    Riordan, R D; Khonsari, M; Jeffries, J; Maskell, G F; Cook, P G

    2004-12-01

    The quality of magnetic resonance cholangiopancreatography (MRCP) images is frequently degraded by high signal from the gastrointestinal tract. The aim of this study is to evaluate pineapple juice (PJ) as an oral negative contrast agent in MRCP. Preliminary in vitro evaluation demonstrated that PJ shortened T(2) relaxation time and hence decreased T(2) signal intensity on a standard MRCP sequence to a similar degree to a commercially available negative contrast agent (ferumoxsil). Electrothermal atomic absorption spectrometry assay demonstrated a high manganese concentration in PJ of 2.76 mg dl(-1), which is likely to be responsible for its T(2) imaging properties. MRCP was subsequently performed in 10 healthy volunteers, before and at 15 min and 30 min following ingestion of 400 ml of PJ. Images were assessed blindly by two Consultant Radiologists using a standard grading technique based on contrast effect (degree of suppression of bowel signal), and image effect (diagnostic quality). There were statistically significant improvements in contrast and image effect between pre and post PJ images. There was particularly significant improvement in visualization of the pancreatic duct, but no significant difference between 15 min and 30 min post PJ images. Visualization of the ampulla, common bile duct, common hepatic and central intrahepatic ducts were also significantly improved at 15 min following PJ. Our results demonstrate that PJ, may be used as an alternative to commercially available negative oral contrast agent in MRCP.

  9. Contribution of cardiovascular magnetic resonance in the evaluation of coronary arteries

    PubMed Central

    Mavrogeni, Sophie; Markousis-Mavrogenis, George; Kolovou, Genovefa

    2014-01-01

    Cardiovascular magnetic resonance (CMR) allows the nonradiating assessment of coronary arteries; to achieve better image quality cardiorespiratory artefacts should be corrected. Coronary MRA (CMRA) at the moment is indicated only for the detection of abnormal coronary origin, coronary artery ectasia and/or aneurysms (class I indication) and coronary bypass grafts (class II indication). CMRA utilisation for coronary artery disease is not yet part of clinical routine. However, the lack of radiation is of special value for the coronary artery evaluation in children and women. CMRA can assess the proximal part of coronary arteries in almost all cases. The best results have been observed in the evaluation of the left anterior descending and the right coronary artery, while the left circumflex, which is located far away from the coil elements, is frequently imaged with reduced quality, compared to the other two. Different studies detected an increase in wall thickness of the coronaries in patients with type I diabetes and abnormal renal function. Additionally, the non-contrast enhanced T1-weighed images detected the presence of thrombus in acute myocardial infarction. New techniques using delayed gadolinium enhanced imaging promise the direct visualization of inflamed plaques in the coronary arteries. The major advantage of CMR is the potential of an integrated protocol offering assessment of coronary artery anatomy, cardiac function, inflammation and stress perfusion-fibrosis in the same study, providing an individualized clinical profile of patients with heart disease. PMID:25349650

  10. Quantitative morphologic evaluation of magnetic resonance imaging during and after treatment of childhood leukemia

    PubMed Central

    Reddick, Wilburn E.; Laningham, Fred H.; Glass, John O.; Pui, Ching-Hon

    2008-01-01

    Introduction Medical advances over the last several decades, including CNS prophylaxis, have greatly increased survival in children with leukemia. As survival rates have increased, clinicians and scientists have been afforded the opportunity to further develop treatments to improve the quality of life of survivors by minimizing the long-term adverse effects. When evaluating the effect of antileukemia therapy on the developing brain, magnetic resonance (MR) imaging has been the preferred modality because it quantifies morphologic changes objectively and noninvasively. Method and results Computer-aided detection of changes on neuroimages enables us to objectively differentiate leukoencephalopathy from normal maturation of the developing brain. Quantitative tissue segmentation algorithms and relaxometry measures have been used to determine the prevalence, extent, and intensity of white matter changes that occur during therapy. More recently, diffusion tensor imaging has been used to quantify microstructural changes in the integrity of the white matter fiber tracts. MR perfusion imaging can be used to noninvasively monitor vascular changes during therapy. Changes in quantitative MR measures have been associated, to some degree, with changes in neurocognitive function during and after treatment Conclusion In this review, we present recent advances in quantitative evaluation of MR imaging and discuss how these methods hold the promise to further elucidate the pathophysiologic effects of treatment for childhood leukemia. PMID:17653705

  11. Can we evaluate cranial aneurysms on conventional brain magnetic resonance imaging?

    PubMed Central

    Caliskan, Emine; Pekcevik, Yeliz; Kaya, Adnan

    2016-01-01

    Purpose: To evaluate the contribution of conventional brain magnetic resonance imaging (MRI) for the determination of intracranial aneurysms. Materials and Methods: Brain MRI and computed tomography angiography (CTA) of 45 patients (29 women and 16 men; age range, 32–80 years) with aneurysm were analyzed. A comparison was made between brain MRI and CTA based on size and presence of aneurysm. The comparisons between MRI and CTA were investigated through Bland-Altman graphics, receiver operating characteristic curve, and Kappa statistics. Results: Fifty-seven aneurysms were evaluated. Forty-five percent of 57 aneurysms on CTA were detected on conventional brain MRI. A significant correlation was found between CTA and brain MRI in the diagnosis of aneurysm (P < 0.05). In an analysis of the size measurement, a significant correlation was observed between CTA and brain MRI. Seventy-seven percent of aneurysms <4 mm was not detected and the efficiency of MRI in the detection of aneurysms <4 mm was found to be low. Conclusion: Aneurysms can also be appreciated on conventional brain MRI, and vascular structures should be reviewed carefully while analyzing brain MRI. PMID:26933351

  12. Evaluation of DNA damage using 3 comet assay parameters in workers occupationally exposed to lead.

    PubMed

    Kayaaltı, Zelıha; Yavuz, İlknur; Söylemez, Esma; Bacaksız, Ayşegül; Tutkun, Engın; Sayal, Ahmet; Söylemezoğlu, Tülın

    2015-01-01

    The aim of this study was to investigate the association between DNA damage and blood lead levels in individuals occupationally exposed to lead. To evaluate this association, 61 workers exposed to lead were monitored in terms of DNA damage in blood lymphocytes. The levels of DNA damage were measured according to 3 comet assay parameters, including tail intensity (TI), tail moment (TM), and DNA tail (DNAt). A statistically significant positive correlation was found between the lead levels and TI, TM, and DNAt (p < .01). Smoking had independent effects on DNA damage. A statistically significant difference was observed between smokers and nonsmokers in regards to DNA damage parameters (p < .05). In addition, the lead and DNA damage levels in smokers were found to be significantly higher than the levels observed in nonsmoking workers (p < . 05). Our results show that exposure to lead induces genotoxic effects in peripheral lymphocytes, as measured by comet assays.

  13. Evaluation of Experimental Parameters in the Accelerated Aging of Closed-Cell Foam Insulation

    SciTech Connect

    Stovall, Therese K; Vanderlan, Michael; Atchley, Jerald Allen

    2012-12-01

    The thermal conductivity of many closed-cell foam insulation products changes over time as production gases diffuse out of the cell matrix and atmospheric gases diffuse into the cells. Thin slicing has been shown to be an effective means of accelerating this process in such a way as to produce meaningful results. Efforts to produce a more prescriptive version of the ASTM C1303 standard test method led to the ruggedness test described here. This test program included the aging of full size insulation specimens for time periods of five years for direct comparison to the predicted results. Experimental parameters under investigation include: slice thickness, slice origin (at the surface or from the core of the slab), thin slice stack composition, product facings, original product thickness, product density, and product type. The test protocol has been completed and this report provides a detailed evaluation of the impact of the test parameters on the accuracy of the 5-year thermal conductivity prediction.

  14. Evaluation of the Ecochemical Status of the Danube in Serbia in Terms of Water Quality Parameters

    PubMed Central

    Takić, Ljiljana; Mladenović-Ranisavljević, Ivana; Vuković, Milovan; Mladenović, Ilija

    2012-01-01

    The Danube is an international river passing partly through Serbia. The protection of the environment and sustainable use of water resources is a primary task that implies constant monitoring of the quality status and evaluation of ecochemical status of the water in the Danube basin. The investigation includes calculation of all-inclusive water quality by the Serbian water quality index (SWQI) method and an evaluation of eco-chemical status of the Danube water in terms of water quality parameters from the entry to the exit point along its course through Serbia in the year of 2009. The results show that the overall quality of the Danube water on the territory of Serbia corresponds to the descriptive indicator of “very good” water. According to the Council Directive75/440/EEC, the evaluation of the ecostatus, with slight deviation of individual parameters at Pančevo, corresponds to A1 category of the surface water quality intended for the abstraction of drinking water supplies in member states. PMID:22645471

  15. Acoustic evaluation of the Helmholtz resonator treatment in the NASA Lewis 8- by 6-foot supersonic wind tunnel

    NASA Technical Reports Server (NTRS)

    Heidelberg, Laurence J.; Gordon, Elliot B.

    1989-01-01

    The acoustic consequences of sealing the Helmholtz resonators of the NASA Lewis 8- by 6-Foot Supersonic Wind Tunnel (8x6 SWT) were experimentally evaluated. This resonator sealing was proposed in order to avoid entrapment of hydrogen during tests of advanced hydrogen-fueled engines. The resonators were designed to absorb energy in the 4- to 20-Hz range; thus, this investigation is primarily concerned with infrasound. Limited internal and external noise measurements were made at tunnel Mach numbers ranging from 0.5 to 2.0. Although the resonators were part of the acoustic treatment installed because of a community noise problem their sealing did not seem to indicate a reoccurrence of the problem would result. Two factors were key to this conclusion: (1) A large bulk treatment muffler downstream of the resonators was able to make up for much of the attenuation originally provided by the resonators, and (2) there was no noise source in the tunnel test section. The previous community noise problem occurred when a large ramjet was tested in an open-loop tunnel configuration. If a propulsion system producing high noise levels at frequencies of less than 10 Hz were tested, the conclusion on community noise would have to be reevaluated.

  16. Multi-Group Formulation of the Temperature-Dependent Resonance Scattering Model and its Impact on Reactor Core Parameters

    SciTech Connect

    Ghrayeb, Shadi Z.; Ougouag, Abderrafi M.; Ouisloumen, Mohamed; Ivanov, Kostadin N.

    2014-01-01

    A multi-group formulation for the exact neutron elastic scattering kernel is developed. It incorporates the neutron up-scattering effects, stemming from lattice atoms thermal motion and accounts for it within the resulting effective nuclear cross-section data. The effects pertain essentially to resonant scattering off of heavy nuclei. The formulation, implemented into a standalone code, produces effective nuclear scattering data that are then supplied directly into the DRAGON lattice physics code where the effects on Doppler Reactivity and neutron flux are demonstrated. The correct accounting for the crystal lattice effects influences the estimated values for the probability of neutron absorption and scattering, which in turn affect the estimation of core reactivity and burnup characteristics. The results show an increase in values of Doppler temperature feedback coefficients up to -10% for UOX and MOX LWR fuels compared to the corresponding values derived using the traditional asymptotic elastic scattering kernel. This paper also summarizes the results done on this topic to date.

  17. Evaluation of the acromiohumeral distance by means of magnetic resonance imaging umerus☆

    PubMed Central

    de Oliveira França, Flávio; Godinho, André Couto; Ribeiro, Elísio José Salgado; Falster, Lorenzo; Búrigo, Lucas Emanuel Gava; Nunes, Rafael Berenstein

    2016-01-01

    Objective To demonstrate the relationship between the size, degree of retraction and topography of rotator cuff injuries and the degree of rise of the humeral head, and to evaluate the influence of gravity, using magnetic resonance imaging (MRI). Methods We evaluated 181 shoulder MRIs from 160 patients aged over 45 years, between November 2013 and July 2014. The patients were divided into two groups: one control (no lesion or partial damage to the rotator cuff); and the other with complete tears of the rotator cuff. We measured the acromiohumeral distance in the sagittal plane, and established the shortest distance between the apex of the head and the acromion. Results In this study, 96 examinations on female patients (53.04%) and 58 on male patients (46.96%) were evaluated. The mean age was 63.27 years: in the control group, 61.46; and in the group with injuries, 65.19. From analysis on the measurements of the subacromial space, we observed significantly higher values in the control group (7.71 mm) than in the group with injuries (6.99). In comparing the control group with some specific subgroup, i.e. posterosuperior (6.77), anteroposterior-superior (4.16) and retraction Patte III (5.01), we confirmed the importance of topography and degree of retraction in relation to the rise of the humeral head. Conclusion The rise of the humeral head was directly related to the size, degree of retraction and topography of the rotator cuff injuries, with greater degrees of rise in cases of superior and posterior lesions and anteroposterior-superior (massive) lesions. The assessment using MRI was not influenced by the force of gravity. PMID:27069885

  18. Analytical evaluation of resonant response of spiral bevel gears in the RAH-66 helicopter Fantail transmission

    NASA Astrophysics Data System (ADS)

    Drago, R. J.; Brown, F. W.

    1992-07-01

    Consideration is given to an analytical approach to the dual problems of defining the occurrence of a potentially damaging resonance and modifying the design of a gear to avoid the resonance. Resonant frequencies were determined for the RAH-66 Fantail gears. A dynamic response level was predicted on the basis of frequency response analyses. The method and criteria utilized indicate acceptable performance without incorporation of axillary damping provisions.

  19. An evaluation of neural networks for identification of system parameters in reactor noise signals

    SciTech Connect

    Miller, L.F.

    1991-01-01

    Several backpropagation neural networks for identifying fundamental mode eigenvalues were evaluated. The networks were trained and tested on analytical data and on results from other numerical methods. They were then used to predict first mode break frequencies for noise data from several sources. These predictions were, in turn, compared with analytical values and with results from alternative methods. Comparisons of results for some data sets suggest that the accuracy of predictions from neural networks are essentially equivalent to results from conventional methods while other evaluations indicate that either method may be superior. Experience gained from these numerical experiments provide insight for improving the performance of neural networks relative to other methods for identifying parameters associated with experimental data. Neural networks may also be used in support of conventional algorithms by providing starting points for nonlinear minimization algorithms.

  20. An evaluation of neural networks for identification of system parameters in reactor noise signals

    SciTech Connect

    Miller, L.F.

    1991-12-31

    Several backpropagation neural networks for identifying fundamental mode eigenvalues were evaluated. The networks were trained and tested on analytical data and on results from other numerical methods. They were then used to predict first mode break frequencies for noise data from several sources. These predictions were, in turn, compared with analytical values and with results from alternative methods. Comparisons of results for some data sets suggest that the accuracy of predictions from neural networks are essentially equivalent to results from conventional methods while other evaluations indicate that either method may be superior. Experience gained from these numerical experiments provide insight for improving the performance of neural networks relative to other methods for identifying parameters associated with experimental data. Neural networks may also be used in support of conventional algorithms by providing starting points for nonlinear minimization algorithms.

  1. Numerical approach for the evaluation of Weibull distribution parameters for hydrologic purposes

    NASA Astrophysics Data System (ADS)

    Pierleoni, A.; Di Francesco, S.; Biscarini, C.; Manciola, P.

    2016-06-01

    In hydrology, the statistical description of low flow phenomena is very important in order to evaluate the available water resource especially in a river and the related values can be obviously considered as random variables, therefore probability distributions dealing with extreme values (maximum and/or minimum) of the variable play a fundamental role. Computational procedures for the estimation of the parameters featuring these distributions are actually very useful especially when embedded into analysis software [1][2] or as standalone applications. In this paper a computational procedure for the evaluation of the Weibull[3] distribution is presented focusing on the case when the lower limit of the distribution is not known or not set to a specific value a priori. The procedure takes advantage of the Gumbel[4] moment approach to the problem.

  2. A possible parameter for gait clinimetric evaluation in Parkinson’s disease patients

    NASA Astrophysics Data System (ADS)

    Lescano, C. N.; Rodrigo, S. E.; Christian, D. A.

    2016-04-01

    The strength and usefulness of a rating scale for describing disease evolution relies on the accurate determination of variations representing clinically relevant changes. In this sense, the habitually used Hoehn-Yahr (HY) Scale for Parkinson Disease (PD) in its modified version distinguishes between the 2 and 2.5 stages to explain if the bilateral involvement is or is not accompanied by body balance impairment. Nevertheless, this scaling does not allow for differentiating the symptoms and signs associated with each stage accurately. Considering this difference, this work aims at analyzing some gait parameters-stance and swing phase times and magnitude of the vertical component of ground reaction force during the gait cycle-of PD patients classified as HY=2 and HY=2.5 in contrast with healthy subjects (HY=0), with the purpose of assessing whether there is a statistically significant difference among all these HY categories. For all gait parameters evaluated, the results indicated significant differences between HY=0 and HY=2.5. However, only the magnitude of the vertical component of ground reaction force presented relevant differences between HY=2 and 2.5. As expected, therefore, these results show the potential of such parameter to clinimetrically identify the level of gait impairment/disability in PD patients on the Hoehn-Yahr Scale.

  3. Evaluation of Anaerobic Biofilm Reactor Kinetic Parameters Using Ant Colony Optimization.

    PubMed

    Satya, Eswari Jujjavarapu; Venkateswarlu, Chimmiri

    2013-09-01

    Fixed bed reactors with naturally attached biofilms are increasingly used for anaerobic treatment of industry wastewaters due their effective treatment performance. The complex nature of biological reactions in biofilm processes often poses difficulty in analyzing them experimentally, and mathematical models could be very useful for their design and analysis. However, effective application of biofilm reactor models to practical problems suffers due to the lack of knowledge of accurate kinetic models and uncertainty in model parameters. In this work, an inverse modeling approach based on ant colony optimization is proposed and applied to estimate the kinetic and film thickness model parameters of wastewater treatment process in an anaerobic fixed bed biofilm reactor. Experimental data of pharmaceutical industry wastewater treatment process are used to determine the model parameters as a consequence of the solution of the rigorous mathematical models of the process. Results were evaluated for different modeling configurations derived from the combination of mathematical models, kinetic expressions, and optimization algorithms. Analysis of results showed that the two-dimensional mathematical model with Haldane kinetics better represents the pharmaceutical wastewater treatment in the biofilm reactor. The mathematical and kinetic modeling of this work forms a useful basis for the design and optimization of industry wastewater treating biofilm reactors.

  4. Evaluation of Anaerobic Biofilm Reactor Kinetic Parameters Using Ant Colony Optimization

    PubMed Central

    Satya, Eswari Jujjavarapu; Venkateswarlu, Chimmiri

    2013-01-01

    Abstract Fixed bed reactors with naturally attached biofilms are increasingly used for anaerobic treatment of industry wastewaters due their effective treatment performance. The complex nature of biological reactions in biofilm processes often poses difficulty in analyzing them experimentally, and mathematical models could be very useful for their design and analysis. However, effective application of biofilm reactor models to practical problems suffers due to the lack of knowledge of accurate kinetic models and uncertainty in model parameters. In this work, an inverse modeling approach based on ant colony optimization is proposed and applied to estimate the kinetic and film thickness model parameters of wastewater treatment process in an anaerobic fixed bed biofilm reactor. Experimental data of pharmaceutical industry wastewater treatment process are used to determine the model parameters as a consequence of the solution of the rigorous mathematical models of the process. Results were evaluated for different modeling configurations derived from the combination of mathematical models, kinetic expressions, and optimization algorithms. Analysis of results showed that the two-dimensional mathematical model with Haldane kinetics better represents the pharmaceutical wastewater treatment in the biofilm reactor. The mathematical and kinetic modeling of this work forms a useful basis for the design and optimization of industry wastewater treating biofilm reactors. PMID:24065871

  5. A highly-efficient technique for evaluating bond-orientational order parameters

    NASA Astrophysics Data System (ADS)

    Winczewski, Szymon; Dziedzic, Jacek; Rybicki, Jarosław

    2016-01-01

    We propose a novel, highly-efficient approach for the evaluation of bond-orientational order parameters (BOPs). Our approach exploits the properties of spherical harmonics and Wigner 3 j-symbols to reduce the number of terms in the expressions for BOPs, and employs simultaneous interpolation of normalised associated Legendre polynomials and trigonometric functions to dramatically reduce the total number of arithmetic operations. Using realistic test cases, we show how the above, combined with a CPU-cache-friendly data structure, leads to a 10 to 50-fold performance increase over approaches currently in use, depending on the size of the interpolation grids and the machine used. As the proposed approach is an approximation, we demonstrate that the errors it introduces are well-behaved, controllable and essentially negligible for practical grid sizes. We benchmark our approach against other structure identification methods (centro-symmetry parameter (CSP), common neighbour analysis (CNA), common neighbourhood parameter (CNP) and Voronoi analysis), generally regarded as much faster than BOPs, and demonstrate that our formulation is able to outperform them for all studied systems.

  6. A path model for evaluating dosing parameters for children with cerebral palsy.

    PubMed

    Gannotti, Mary E; Christy, Jennifer B; Heathcock, Jill C; Kolobe, Thubi H A

    2014-03-01

    Dosing of pediatric rehabilitation services for children with cerebral palsy (CP) has been identified as a national priority. Establishing dosing parameters for pediatric physical therapy interventions is critical for informing clinical decision making, health policy, and guidelines for reimbursement. The purpose of this perspective article is to describe a path model for evaluating dosing parameters of interventions for children with CP. The model is intended for dose-related and effectiveness studies of pediatric physical therapy interventions. The premise of the model is: Intervention type (focus on body structures, activity, or the environment) acts on a child first through the family, then through the dose (frequency, intensity, time), to yield structural and behavioral changes. As a result, these changes are linked to improvements in functional independence. Community factors affect dose as well as functional independence (performance and capacity), influencing the relationships between type of intervention and intervention responses. The constructs of family characteristics; child characteristics (eg, age, level of severity, comorbidities, readiness to change, preferences); plastic changes in bone, muscle, and brain; motor skill acquisition; and community access warrant consideration from researchers who are designing intervention studies. Multiple knowledge gaps are identified, and a framework is provided for conceptualizing dosing parameters for children with CP.

  7. An evaluation of earthquake hazard parameters in the Iranian Plateau based on the Gumbel III distribution

    NASA Astrophysics Data System (ADS)

    Mohammadi, Hiwa; Bayrak, Yusuf

    2016-04-01

    The Gumbel's third asymptotic distribution (GIII) of the extreme value method is employed to evaluate the earthquake hazard parameters in the Iranian Plateau. This research quantifies spatial mapping of earthquake hazard parameters like annual and 100-year mode beside their 90 % probability of not being exceeded (NBE) in the Iranian Plateau. Therefore, we used a homogeneous and complete earthquake catalogue during the period 1900-2013 with magnitude M w ≥ 4.0, and the Iranian Plateau is separated into equal area mesh of 1° late × 1° long. The estimated result of annual mode with 90 % probability of NBE is expected to exceed the values of M w 6.0 in the Eastern part of Makran, most parts of Central and East Iran, Kopeh Dagh, Alborz, Azerbaijan, and SE Zagros. The 100-year mode with 90 % probability of NBE is expected to overpass the value of M w 7.0 in the Eastern part of Makran, Central and East Iran, Alborz, Kopeh Dagh, and Azerbaijan. The spatial distribution of 100-year mode with 90 % probability of NBE uncovers the high values of earthquake hazard parameters which are frequently connected with the main tectonic regimes of the studied area. It appears that there is a close communication among the seismicity and the tectonics of the region.

  8. Evaluation of voice pathology based on the estimation of vocal fold biomechanical parameters.

    PubMed

    Gómez-Vilda, P; Fernández-Baillo, R; Nieto, A; Díaz, F; Fernández-Camacho, F J; Rodellar, V; Alvarez, A; Martínez, R

    2007-07-01

    Voice disorders are a source of increasing concern as normal voice quality is a social demand for at least one third of the population in developed countries in cases where voice is an essential resource in professional exercise. In addition, the growing exposure to certain pathogenic factors such as smoking, alcohol abuse, air pollution, and acoustic contamination, and other problems such as gastro-esopharyngeal reflux or allergy as well as aging, aggravate voice disorders. Voice pathologies justify the assignment of larger resources to prevention policies, early detection, and less aggressive treatments. Traditional pathology detection relies on perceptive evaluation methods (GRABS), acoustic analysis, and visual inspection (indirect laryngoscopy, and modern fibro-endo-stroboscopy). This article describes a method for voice pathology detection based on the noninvasive estimation of vocal cord biomechanical parameters derived from voice using specific signal processing methods. Preliminary results using records from patients showing four frequent causes of voice pathology (nodules, polyps, chronic laryngitis, and Reinke's edema) are given. The results show that the alteration (distortion, unbalance, or deviation) of cord biomechanical parameters may serve as an indicator of pathology. Statistical methods based on hierarchical clustering and principal component analysis reveal that combining biomechanical estimates with classic perturbation parameters increases the accuracy of acoustic analysis, improving the detection of voice pathology. This research could open new possibilities for noninvasive screening of vocal fold pathologies and could be used in the implantation of e-health voice care services. PMID:16549321

  9. A Path Model for Evaluating Dosing Parameters for Children With Cerebral Palsy

    PubMed Central

    Christy, Jennifer B.; Heathcock, Jill C.; Kolobe, Thubi H.A.

    2014-01-01

    Dosing of pediatric rehabilitation services for children with cerebral palsy (CP) has been identified as a national priority. Establishing dosing parameters for pediatric physical therapy interventions is critical for informing clinical decision making, health policy, and guidelines for reimbursement. The purpose of this perspective article is to describe a path model for evaluating dosing parameters of interventions for children with CP. The model is intended for dose-related and effectiveness studies of pediatric physical therapy interventions. The premise of the model is: Intervention type (focus on body structures, activity, or the environment) acts on a child first through the family, then through the dose (frequency, intensity, time), to yield structural and behavioral changes. As a result, these changes are linked to improvements in functional independence. Community factors affect dose as well as functional independence (performance and capacity), influencing the relationships between type of intervention and intervention responses. The constructs of family characteristics; child characteristics (eg, age, level of severity, comorbidities, readiness to change, preferences); plastic changes in bone, muscle, and brain; motor skill acquisition; and community access warrant consideration from researchers who are designing intervention studies. Multiple knowledge gaps are identified, and a framework is provided for conceptualizing dosing parameters for children with CP. PMID:24231231

  10. Evaluation of voice pathology based on the estimation of vocal fold biomechanical parameters.

    PubMed

    Gómez-Vilda, P; Fernández-Baillo, R; Nieto, A; Díaz, F; Fernández-Camacho, F J; Rodellar, V; Alvarez, A; Martínez, R

    2007-07-01

    Voice disorders are a source of increasing concern as normal voice quality is a social demand for at least one third of the population in developed countries in cases where voice is an essential resource in professional exercise. In addition, the growing exposure to certain pathogenic factors such as smoking, alcohol abuse, air pollution, and acoustic contamination, and other problems such as gastro-esopharyngeal reflux or allergy as well as aging, aggravate voice disorders. Voice pathologies justify the assignment of larger resources to prevention policies, early detection, and less aggressive treatments. Traditional pathology detection relies on perceptive evaluation methods (GRABS), acoustic analysis, and visual inspection (indirect laryngoscopy, and modern fibro-endo-stroboscopy). This article describes a method for voice pathology detection based on the noninvasive estimation of vocal cord biomechanical parameters derived from voice using specific signal processing methods. Preliminary results using records from patients showing four frequent causes of voice pathology (nodules, polyps, chronic laryngitis, and Reinke's edema) are given. The results show that the alteration (distortion, unbalance, or deviation) of cord biomechanical parameters may serve as an indicator of pathology. Statistical methods based on hierarchical clustering and principal component analysis reveal that combining biomechanical estimates with classic perturbation parameters increases the accuracy of acoustic analysis, improving the detection of voice pathology. This research could open new possibilities for noninvasive screening of vocal fold pathologies and could be used in the implantation of e-health voice care services.

  11. Litchi freshness rapid non-destructive evaluating method using electronic nose and non-linear dynamics stochastic resonance model

    PubMed Central

    Ying, Xiaoguo; Liu, Wei; Hui, Guohua

    2015-01-01

    In this paper, litchi freshness rapid non-destructive evaluating method using electronic nose (e-nose) and non-linear stochastic resonance (SR) was proposed. EN responses to litchi samples were continuously detected for 6 d Principal component analysis (PCA) and non-linear stochastic resonance (SR) methods were utilized to analyze EN detection data. PCA method could not totally discriminate litchi samples, while SR signal-to-noise ratio (SNR) eigen spectrum successfully discriminated all litchi samples. Litchi freshness predictive model developed using SNR eigen values shows high predictive accuracy with regression coefficients R2 = 0 .99396. PMID:25920547

  12. Evaluation of demographic parameters of native rodent populations and implications for control

    PubMed Central

    French, Norman R.

    1975-01-01

    The ecology of the multimammate mouse ,Mastomys natalensis, is reviewed and approximations are derived for the parameters governing population growth. By means of computer simulation, the relative importance of the timing of reproduction, the age class distribution or age structure of the population, the competition between Mastomys and Rattus, and the interaction with a predator are evaluated. Although each of these demographic or ecological factors modifies the fate of the Mastomys population, the greatest single impact results from a reproductive season that is divided into two parts rather than a single continuous reproductive season. Division into two parts, correlated with a similar distribution of rainfall, allows time for maturing of the young born early in the season and for production of young by them, thus adding to the momentum of population increase. The interaction of density-dependent factors controlling population growth, competition with another rodent, or predation by a Viverrid predator, may increase the growth rate of the Mastomys population or may depress population growth rate, even to the point of extinction. These simulation studies demonstrate the necessity for critical evaluation of the demographic parameters and ecological characteristics of a particular Mastomys population before an effective control programme can be designed. They also demonstrate, however, that if the programme is based upon sound ecological theory control can be effected. PMID:1085223

  13. Evaluating the electrical discharge machining (EDM) parameters with using carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Sari, M. M.; Noordin, M. Y.; Brusa, E.

    2012-09-01

    Electrical discharge machining (EDM) is one of the most accurate non traditional manufacturing processes available for creating tiny apertures, complex or simple shapes and geometries within parts and assemblies. Performance of the EDM process is usually evaluated in terms of surface roughness, existence of cracks, voids and recast layer on the surface of product, after machining. Unfortunately, the high heat generated on the electrically discharged material during the EDM process decreases the quality of products. Carbon nanotubes display unexpected strength and unique electrical and thermal properties. Multi-wall carbon nanotubes are therefore on purpose added to the dielectric used in the EDM process to improve its performance when machining the AISI H13 tool steel, by means of copper electrodes. Some EDM parameters such as material removal rate, electrode wear rate, surface roughness and recast layer are here first evaluated, then compared to the outcome of EDM performed without using nanotubes mixed to the dielectric. Independent variables investigated are pulse on time, peak current and interval time. Experimental evidences show that EDM process operated by mixing multi-wall carbon nanotubes within the dielectric looks more efficient, particularly if machining parameters are set at low pulse of energy.

  14. Evaluation of Toxicity Effects of Asafetida on Biochemical, Hematological, and Histological Parameters in Male Wistar Rats

    PubMed Central

    Bagheri, Seyyed Majid; Yadegari, Maryam; Mirjalily, Aghdas; Rezvani, Mohammd Ebrahim

    2015-01-01

    Objectives: Asafetida is traditionally used in folklore medicine for the treatment of various ailments. To validate its use in traditional medicine, it is important to evaluate its toxicity in the animal system. Therefore, this study aimed to evaluate the toxicological effects of asafetida in Wistar albino rats. Materials and Methods: Acute toxicity tests were conducted by the oral administration of 250, 500, and 1,000 mg/kg body weight of the animal. In chronic study, animals were administered with various doses of asafetida (25, 50, 100, and 200 mg/kg body weight) for a period of 6 weeks. At end of experiment, the effects of asafetida on hematological, renal, and hepatic markers and histological parameters were analyzed. Results: In acute toxicity study, no mortality was seen up to 72 h of the administration of asafetida. No signs of neurological and behavioral changes were noticed within 24 h. In the chronic study, the asafetida intake has changed the hematological parameters such as red blood cell (RBC), white blood cell (WBC), hematocrit (HCT), and platelets. Aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were significantly increased in treated animals. The plasma level of urea and creatinine were not altered by the administration of asafetida throughout the study. Histopathology study indicates hepatotoxicity, but no signs of prominent pathological changes in kidney. Conclusions: Asafetida did not show any acute toxicity, but chronic administration could have undesirable effects on hepatocytes and hematological factors. PMID:26862262

  15. Evaluating an Online Resourcefulness Training Intervention Pilot Test Using Six Critical Parameters.

    PubMed

    Musil, Carol M; Zauszniewski, Jaclene A; Burant, Christopher J; Toly, Valerie B; Warner, Camille B

    2015-12-01

    Few resources are available to help grandmother caregivers to grandchildren manage their complex family situations that may have immediate and long-term consequences for themselves and their families. Resourcefulness training is an intervention designed to help grandmothers improve their ability to deal with these problems. The purpose of this pilot study was to evaluate the necessity, feasibility, acceptability, fidelity, safety, and effectiveness (i.e., effect sizes) of an online, computer-based resourcefulness training intervention that was adapted from a face-to-face intervention. Twelve grandmothers raising or living with grandchildren participated in the pilot intervention that included (a) watching an instructional video on resourcefulness, (b) completing two online questionnaires over a 6-week time period, and (c) writing in an online journal every day for 4 weeks. Data are evaluated within the context of the six parameters important to intervention development. Qualitative and quantitative results provide initial support for all six parameters. Recommendations to improve aspects of the intervention are discussed. PMID:26738997

  16. Markers/parameters for the evaluation of natural resistance status of small ruminants against gastrointestinal nematodes.

    PubMed

    Saddiqi, H A; Sarwar, M; Iqbal, Z; Nisa, M; Shahzad, M A

    2012-06-01

    The high prevalence of anthelmintic-resistant gastrointestinal nematodes (GINs) throughout the world has led to the need for alternative worm control strategies. One of the possible substitutes to reduce the problems of drug resistance and residue is the evaluation/breeding of small ruminants for greater resistance to the GINs (organically produced), which in turn would be a helpful tool to predict the performance of an animal. At present, the existing diversity in the genetic potential to resist/tolerate GINs infection both within and between breeds has been validated. Successful selection of animals to define the genotype and identified resistance is related to the employed markers. A number of phenotypic traits such as faecal egg count (FEC), worm burden, serum antibodies, peripheral eosinophilia, packed cell volume, live weight, serum protein and albumin concentrations have been used for this purpose both in natural and artificial infections. Relatively resistant/tolerant animals have also been found to have mastocytosis, globule leucocytes, high levels of histamine and immunoglobulin (Ig) A and IgE concentrations. Of these traits, the principal and most practical measurement used to assess resistance status in animals undergoing similar parasite challenges is FEC. FEC has a positive/negative correlation with other biochemical, cellular and immunological parameters; however, the reliability of individual trial is often questioned and valuable information regarding the genetic makeup can be obtained from pooled data of a large number of trials and parameters. This paper covers all the aspects reported in the literature on various parameters considered to evaluate the resistance status of a range of small ruminant breeds. PMID:22558970

  17. Parameter Choice and Constraint in Hydrologic Models for Evaluating Land Use Change

    NASA Astrophysics Data System (ADS)

    Jackson, C. R.

    2011-12-01

    Hydrologic models are used to answer questions, from simple, "what is the expected 100-year peak flow for a basin?", to complex, "how will land use change alter flow pathways, flow time series, and water chemistry?" Appropriate model structure and complexity depend on the questions being addressed. Numerous studies of simple transfer models for converting climate signals into streamflows suggest that only three or four parameters are needed. The conceptual corollary to such models is a single hillslope bucket with storage, evapotranspiration, fast flow, and slow flow. While having the benefit of low uncertainty, such models are ill-suited to addressing land use questions. Land use questions require models that can simulate effects of changes in vegetation, alterations of soil characteristics, and resulting changes in flow pathways. For example, minimum goals for a hydrologic model evaluating bioenergy feedstock production might include: 1) calculate Horton overland flow based on surface conductivities and saturated surface flow based on relative moisture content in the topsoils, 2) allow reinfiltration of Horton overland flow created by bare soils, compacted soils, and pavement (roads, logging roads, skid trails, landings), 3) account for root zone depth and LAI in transpiration calculations, 4) allow mixing of hillslope flows in the riparian aquifer, 5) allow separate simulation of the riparian soils and vegetation and upslope soils and vegetation, 6) incorporate important aspects of topography and stratigraphy, and 7) estimate residence times in different flow paths. How many parameters are needed for such a model, and what information beside streamflow can be collected to constrain the parameters? Additional information that can be used for evaluating and testing watershed models are in-situ conductivity measurements, soil porosity, soil moisture dynamics, shallow perched groundwater behavior, interflow occurrence, groundwater behavior, regional ET estimates

  18. Controlling precise magnetic field configuration around electron cyclotron resonance zone for enhancing plasma parameters and beam current

    SciTech Connect

    Yano, Keisuke Kurisu, Yosuke; Nozaki, Dai; Kimura, Daiju; Imai, Youta; Kumakura, Sho; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki

    2014-02-15

    Multi-charged ion source which has wide operating conditions is required in various application fields. We have constructed tandem type ECR ion source (ECRIS); one of the features of its main stage is an additional coil for controlling magnetic field distribution around the mirror bottom precisely. Here the effect of magnetic field variation caused by the additional coil is experimentally considered in terms of plasma parameters and beam current as the first investigation of the main stage plasma. Furthermore, behavior of magnetic lines of force flowing from the ECR zone is calculated, and is compared with measurement results aiming for better understanding of interrelationship between plasma production and ion beam generation on the ECRIS.

  19. Radiographic Evaluation of Valvular Heart Disease With Computed Tomography and Magnetic Resonance Correlation.

    PubMed

    Lempel, Jason K; Bolen, Michael A; Renapurkar, Rahul D; Azok, Joseph T; White, Charles S

    2016-09-01

    Valvular heart disease is a group of complex entities with varying etiologies and clinical presentations. There are a number of imaging tools available to supplement clinical evaluation of suspected valvular heart disease, with echocardiography being the most common and clinically established, and more recent emergence of computed tomography and magnetic resonance imaging as additional supportive techniques. Yet even with these newer and more sophisticated modalities, chest radiography remains one of the earliest and most common diagnostic examinations performed during the triage of patients with suspected cardiac dysfunction. Recognizing the anatomic and pathologic features of cardiac radiography including the heart's adaptation to varying hemodynamic changes can provide clues to the radiologist regarding the underlying etiology. In this article, we will elucidate several principles relating to chamber modifications in response to pressure and volume overload as well as radiographic appearances associated with pulmonary fluid status and cardiac dysfunction. We will also present a pattern approach to optimize analysis of the chest radiograph for valvular heart disease, which will help guide the radiologist down a differential diagnostic pathway and create a more meaningful clinical report. PMID:27548877

  20. Magnetic resonance enterography for the evaluation of the deep small intestine in Crohn's disease.

    PubMed

    Ohtsuka, Kazuo; Takenaka, Kento; Kitazume, Yoshio; Fujii, Toshimitsu; Matsuoka, Katsuyoshi; Kimura, Maiko; Nagaishi, Takashi; Watanabe, Mamoru

    2016-04-01

    For the control of Crohn's disease (CD) a thorough assessment of the small intestine is essential; several modalities may be utilized, with cross-sectional imaging being important. Magnetic resonance (MR) enterography, i.e., MRE is recommended as a modality with the highest accuracy for CD lesions. MRE and MR enteroclysis are the two methods performed following distension of the small intestine. MRE has sensitivity and specificity comparable to computed tomography enterography (CTE); although images obtained using MRE are less clear compared with CTE, MRE does not expose the patient to radiation and is superior for soft-tissue contrast. Furthermore, it can assess not only static but also dynamic and functional imaging and reveals signs of CD, such as abscess, comb sign, fat edema, fistula, lymph node enhancement, less motility, mucosal lesions, stricture, and wall enhancement. Several indices of inflammatory changes and intestinal damage have been proposed for objective evaluation. Recently, diffusion-weighted imaging has been proposed, which does not need bowel preparation and contrast enhancement. Comprehension of the characteristics of MRE and other modalities is important for better management of CD. PMID:27175112

  1. Magnetic resonance enterography for the evaluation of the deep small intestine in Crohn's disease

    PubMed Central

    Takenaka, Kento; Kitazume, Yoshio; Fujii, Toshimitsu; Matsuoka, Katsuyoshi; Kimura, Maiko; Nagaishi, Takashi; Watanabe, Mamoru

    2016-01-01

    For the control of Crohn's disease (CD) a thorough assessment of the small intestine is essential; several modalities may be utilized, with cross-sectional imaging being important. Magnetic resonance (MR) enterography, i.e., MRE is recommended as a modality with the highest accuracy for CD lesions. MRE and MR enteroclysis are the two methods performed following distension of the small intestine. MRE has sensitivity and specificity comparable to computed tomography enterography (CTE); although images obtained using MRE are less clear compared with CTE, MRE does not expose the patient to radiation and is superior for soft-tissue contrast. Furthermore, it can assess not only static but also dynamic and functional imaging and reveals signs of CD, such as abscess, comb sign, fat edema, fistula, lymph node enhancement, less motility, mucosal lesions, stricture, and wall enhancement. Several indices of inflammatory changes and intestinal damage have been proposed for objective evaluation. Recently, diffusion-weighted imaging has been proposed, which does not need bowel preparation and contrast enhancement. Comprehension of the characteristics of MRE and other modalities is important for better management of CD. PMID:27175112

  2. Evaluation of crocin and curcumin affinity on mushroom tyrosinase using surface plasmon resonance.

    PubMed

    Patil, Sushama; Srinivas, Sistla; Jadhav, Jyoti

    2014-04-01

    Tyrosinase inhibitors have potential applications in the cosmetics and food industries for preventing browning reactions and also as therapeutic drugs for neurodegenerative diseases such as Parkinson's. In this article, crocin and curcumin were evaluated as mushroom tyrosinase inhibitors. Results showed that, both compounds strongly inhibited the diphenolase activity than monophenolase. The IC50 values for diphenolase activity were estimated to be 0.11 mM and 0.18 mM for crocin and curcumin respectively. The binding kinetics of crocin and curcumin was studied with mushroom tyrosinase using surface plasmon resonance (SPR). Tyrosinase was immobilized on the gold surface of a Biacore sensor chip through amine coupling. Binding of inhibitors was analyzed by SPR without the need to further modify the surface or the use of other reagents. The binding constant KD (M) for mushroom tyrosinase obtained was 1.21×10(-4) M for crocin and 1.64×10(-4) M for curcumin, while showing a higher affinity for L-DOPA 1.95×10(-8) M, a substrate for tyrosinase (positive control). The study reveals the SPR sensor's ability to detect binding of the inhibitors.

  3. Magnetic resonance imaging in the evaluation of tibial eminence fractures in adults.

    PubMed

    Monto, Raymond Rocco; Cameron-Donaldson, Michelle L; Close, Matthew A; Ho, Charles P; Hawkins, Richard J

    2006-07-01

    Proton density and T2-weighted sagittal, axial, coronal, and inversion recovery fat suppression magnetic resonance imaging (MRI) sequences were reviewed in 21 adults (10 men and 11 women) with 22 tibial eminence fractures. Average patient age was 43 years (range: 19-62 years). There were 3 type I, 3 type II, 12 type III, and 4 type IV fractures. The average fracture fragment size was 21 x 23 mm, and the average displacement was 5.5 mm (range: 0-12 mm). The MRI disclosed anterior cruciate ligament (ACL) insertional avulsions in 20 (91%), distal posterior cruciate ligament (PCL) avulsions in 4 (18%), intrasubstance ACL damage in 9 (41%), intrasubstance PCL injury in 3 (14%), medial collateral ligament (MCL) tears in 9 (41%) knees, retinacular injury in 8 (36%), posterolateral corner damage in 8 (36%), medial meniscal tears in 5 (23%), and 4 (18%) had lateral meniscal tears. Occult subchondral osseous injuries were seen in the posterolateral tibial plateau in 13 (59%) knees, anterolateral femoral condyle in 4 (18%), and posteromedial tibial plateau in 5 (23%) knees. Discrete osteochondral fractures were present in 7 (32%) knees. Significant osseous, cartilaginous, meniscal, and ligamentous damage was discovered in all patients. Based on these findings, we recommend MRI evaluation of all tibial eminence fractures to accurately detect all knee damage.

  4. Early characteristic findings in bowleg deformities: evaluation using magnetic resonance imaging.

    PubMed

    Mukai, S; Suzuki, S; Seto, Y; Kashiwagi, N; Hwang, E S

    2000-01-01

    We used magnetic resonance imaging (MRI) to evaluate bowleg deformities in infancy. Twenty-five tibiae of 13 infants were examined and divided into two groups based on MRI findings: group A had high intensity area in the medial epiphyseal cartilage on T2-weighted images. Group B had depression of medial physis and abnormal signal in the perichondrial region in addition to the epiphyseal lesion. At the final follow-up, all cases in group A demonstrated normal lower leg alignments, whereas five cases in group B showed characteristic roentogenographic findings of Blount's disease. The improvement rate of metaphyseal-diaphyseal angle was correlated with this classification. These findings suggested that abnormal findings in physis and perichondrial region might be preliminary findings in early stage of Blount's disease. The high intensity areas in the medial epiphyseal cartilage were commonly found among the cases with bowing deformities, which suggested that there might be a common pathomechanism between physiologic bowing and infantile Blount's disease. PMID:11008740

  5. Evaluation of crocin and curcumin affinity on mushroom tyrosinase using surface plasmon resonance.

    PubMed

    Patil, Sushama; Srinivas, Sistla; Jadhav, Jyoti

    2014-04-01

    Tyrosinase inhibitors have potential applications in the cosmetics and food industries for preventing browning reactions and also as therapeutic drugs for neurodegenerative diseases such as Parkinson's. In this article, crocin and curcumin were evaluated as mushroom tyrosinase inhibitors. Results showed that, both compounds strongly inhibited the diphenolase activity than monophenolase. The IC50 values for diphenolase activity were estimated to be 0.11 mM and 0.18 mM for crocin and curcumin respectively. The binding kinetics of crocin and curcumin was studied with mushroom tyrosinase using surface plasmon resonance (SPR). Tyrosinase was immobilized on the gold surface of a Biacore sensor chip through amine coupling. Binding of inhibitors was analyzed by SPR without the need to further modify the surface or the use of other reagents. The binding constant KD (M) for mushroom tyrosinase obtained was 1.21×10(-4) M for crocin and 1.64×10(-4) M for curcumin, while showing a higher affinity for L-DOPA 1.95×10(-8) M, a substrate for tyrosinase (positive control). The study reveals the SPR sensor's ability to detect binding of the inhibitors. PMID:24444880

  6. Microvascular Obstruction Evaluation Using Cardiovascular Magnetic Resonance (CMR) in ST-Elevated Myocardial Infarction (STEMI) Patients

    PubMed Central

    Piotrowska-Kownacka, Dorota; Kownacki, Łukasz; Kochman, Janusz; Kołodzińska, Agnieszka; Kobylecka, Małgorzata; Królicki, Leszek

    2015-01-01

    Summary Backround Restoration of blood flow in epicardial coronary artery in patients with acute myocardial infarction can, but does not have to restore efficient blood flow in coronary circulation. The aim of the study was a direct comparison of microvascular obstruction (MVO) detected by rest and stress perfusion imaging and gadolinium enhancement obtained 2 min. (early MVO) and 15 min. (delayed MVO) post contrast. Material/Methods 106 patients with first anterior myocardial infarction were studied. Cardiovascular magnetic resonance (CMR) was performed 5±2 days after primary percutaneous coronary intervention (pPCI). Stress and rest perfusion imaging was performed as well as early and delayed gadolinium enhancement and systolic function assessment. Scoring of segmental function, perfusion defect, MVO and scar transmurality was performed in 16 segment left ventricular model. Results The prevalence of MVO varies significantly between imaging techniques ranging from 48.8% for delayed MVO to 94% with stress perfusion. Median sum of scores was significantly different for each technique: stress perfusion 13 (7; 18), rest perfusion 3 (0.5; 6), early MVO 3 (0; 8), delayed MVO 0 (0; 4); p<0.05. Infarct size, stress and rest perfusion defects were independent predictors of LV EF at discharge from hospital. Conclusions Imaging protocol has a significant impact on MVO results. The study is the first to describe a stress-induced MVO in STEMI patients. Further research is needed to evaluate its impact on a long term prognosis. PMID:26740825

  7. Magnetic resonance imaging evaluation of meniscoid superior labrum: normal variant or superior labral tear*

    PubMed Central

    Simão, Marcelo Novelino; Vinson, Emily N.; Spritzer, Charles E.

    2016-01-01

    Objective The objective of this study was to determine the incidence of a "meniscoid" superior labrum. Materials and Methods This was a retrospective analysis of 582 magnetic resonance imaging examinations of shoulders. Of those 582 examinations, 110 were excluded, for a variety of reasons, and the final analysis therefore included 472 cases. Consensus readings were performed by three musculoskeletal radiologists using specific criteria to diagnose meniscoid labra. Results A meniscoid superior labrum was identified in 48 (10.2%) of the 472 cases evaluated. Arthroscopic proof was available in 21 cases (43.8%). In 10 (47.6%) of those 21 cases, the operative report did not include the mention a superior labral tear, thus suggesting the presence of a meniscoid labrum. In only one of those cases were there specific comments about a mobile superior labrum (i.e., meniscoid labrum). In the remaining 11 (52.4%), surgical correlation demonstrated superior labral tears. Conclusion A meniscoid superior labrum is not an infrequent finding. Depending upon assumptions and the requirement of surgical proof, the prevalence of a meniscoid superior labrum in this study was between 2.1% (surgically proven) and 4.8% (projected). However, superior labral tears are just as common and are often confused with meniscoid labra. PMID:27777474

  8. [Evaluation of the risk of overheating and displacement of orthodontic devices in magnetic resonance imaging].

    PubMed

    Yassi, K; Ziane, F; Bardinet, E; Moinard, M; Veyret, B; Chateil, J F

    2007-02-01

    The use of magnetic resonance imaging (MRI) in the exploration of the orofacial region of patients who have orthodontic appliances can be disturbed by artifacts, with a theoretical risk of displacement and overheating of the different materials used in odontology. The purpose of this study was to evaluate the thermal effects and the risk of displacement induced by MRI on certain metallic devices used in orthodontics. The results show a very moderate increase in temperature of the materials during MRI exposure, less than 1 degrees C, in particular in the metal wire linking the brackets. The maximal forces observed were on the order of 0.27 N. The risk of detachment and displacement seems to be nonexistent at 1.5 Tesla when the usual recommendations are respected. Temporary removal of the wire and verification of the adhesive is recommended. However, priority should be given to nonmagnetic or slightly magnetic material to limit artifacts as much as possible when exploring the head region.

  9. Evaluation of expert criteria for preoperative magnetic resonance imaging of newly diagnosed breast cancer.

    PubMed

    Behrendt, Carolyn E; Tumyan, Lusine; Gonser, Laura; Shaw, Sara L; Vora, Lalit; Paz, I Benjamin; Ellenhorn, Joshua D I; Yim, John H

    2014-08-01

    Despite 2 randomized trials reporting no reduction in operations or local recurrence at 1 year, preoperative magnetic resonance imaging (MRI) is increasingly used in diagnostic workup of breast cancer. We evaluated 5 utilization criteria recently proposed by experts. Of women (n = 340) newly diagnosed with unilateral breast cancer who underwent bilateral MRI, most (69.4%) met at least 1 criterion before MRI: mammographic density (44.4%), under consideration for partial breast irradiation (PBI) (19.7%), genetic-familial risk (12.9%), invasive lobular carcinoma (11.8%), and multifocal/multicentric disease (10.6%). MRI detected occult malignant lesion or extension of index lesion in 21.2% of index, 3.3% of contralateral, breasts. No expert criterion was associated with MRI-detected malignant lesion, which associated instead with pre-MRI plan of lumpectomy without PBI (48.2% of subjects): Odds Ratio 3.05, 95% CI 1.57-5.91 (p adjusted for multiple hypothesis testing = 0.007, adjusted for index-vs-contralateral breast and covariates). The expert guidelines were not confirmed by clinical evidence.

  10. Benchmark Testing of a New 56Fe Evaluation for Criticality Safety Applications

    SciTech Connect

    Leal, Luiz C; Ivanov, E.

    2015-01-01

    The SAMMY code was used to evaluate resonance parameters of the 56Fe cross section in the resolved resonance energy range of 0–2 MeV using transmission data, capture, elastic, inelastic, and double differential elastic cross sections. The resonance analysis was performed with the code SAMMY that fits R-matrix resonance parameters using the generalized least-squares technique (Bayes’ theory). The evaluation yielded a set of resonance parameters that reproduced the experimental data very well, along with a resonance parameter covariance matrix for data uncertainty calculations. Benchmark tests were conducted to assess the evaluation performance in benchmark calculations.

  11. Can a combination of ultrasonographic parameters accurately evaluate concussion and guide return-to-play decisions?

    PubMed

    Cartwright, Michael S; Dupuis, Janae E; Bargoil, Jessica M; Foster, Dana C

    2015-09-01

    Mild traumatic brain injury, often referred to as concussion, is a common, potentially debilitating, and costly condition. One of the main challenges in diagnosing and managing concussion is that there is not currently an objective test to determine the presence of a concussion and to guide return-to-play decisions for athletes. Traditional neuroimaging tests, such as brain magnetic resonance imaging, are normal in concussion, and therefore diagnosis and management are guided by reported symptoms. Some athletes will under-report symptoms to accelerate their return-to-play and others will over-report symptoms out of fear of further injury or misinterpretation of underlying conditions, such as migraine headache. Therefore, an objective measure is needed to assist in several facets of concussion management. Limited data in animal and human testing indicates that intracranial pressure increases slightly and cerebrovascular reactivity (the ability of the cerebral arteries to auto-regulate in response to changes in carbon dioxide) decreases slightly following mild traumatic brain injury. We hypothesize that a combination of ultrasonographic measurements (optic nerve sheath diameter and transcranial Doppler assessment of cerebrovascular reactivity) into a single index will allow for an accurate and non-invasive measurement of intracranial pressure and cerebrovascular reactivity, and this index will be clinically relevant and useful for guiding concussion diagnosis and management. Ultrasound is an ideal modality for the evaluation of concussion because it is portable (allowing for evaluation in many settings, such as on the playing field or in a combat zone), radiation-free (making repeat scans safe), and relatively inexpensive (resulting in nearly universal availability). This paper reviews the literature supporting our hypothesis that an ultrasonographic index can assist in the diagnosis and management of concussion, and it also presents limited data regarding the

  12. Can a combination of ultrasonographic parameters accurately evaluate concussion and guide return-to-play decisions?

    PubMed

    Cartwright, Michael S; Dupuis, Janae E; Bargoil, Jessica M; Foster, Dana C

    2015-09-01

    Mild traumatic brain injury, often referred to as concussion, is a common, potentially debilitating, and costly condition. One of the main challenges in diagnosing and managing concussion is that there is not currently an objective test to determine the presence of a concussion and to guide return-to-play decisions for athletes. Traditional neuroimaging tests, such as brain magnetic resonance imaging, are normal in concussion, and therefore diagnosis and management are guided by reported symptoms. Some athletes will under-report symptoms to accelerate their return-to-play and others will over-report symptoms out of fear of further injury or misinterpretation of underlying conditions, such as migraine headache. Therefore, an objective measure is needed to assist in several facets of concussion management. Limited data in animal and human testing indicates that intracranial pressure increases slightly and cerebrovascular reactivity (the ability of the cerebral arteries to auto-regulate in response to changes in carbon dioxide) decreases slightly following mild traumatic brain injury. We hypothesize that a combination of ultrasonographic measurements (optic nerve sheath diameter and transcranial Doppler assessment of cerebrovascular reactivity) into a single index will allow for an accurate and non-invasive measurement of intracranial pressure and cerebrovascular reactivity, and this index will be clinically relevant and useful for guiding concussion diagnosis and management. Ultrasound is an ideal modality for the evaluation of concussion because it is portable (allowing for evaluation in many settings, such as on the playing field or in a combat zone), radiation-free (making repeat scans safe), and relatively inexpensive (resulting in nearly universal availability). This paper reviews the literature supporting our hypothesis that an ultrasonographic index can assist in the diagnosis and management of concussion, and it also presents limited data regarding the

  13. Can a Combination of Ultrasonographic Parameters Accurately Evaluate Concussion and Guide Return-to-Play Decisions?

    PubMed Central

    Cartwright, Michael S.; Dupuis, Janae E.; Bargoil, Jessica M.; Foster, Dana C.

    2015-01-01

    Mild traumatic brain injury, often referred to as concussion, is a common, potentially debilitating, and costly condition. One of the main challenges in diagnosing and managing concussion is that there is not currently an objective test to determine the presence of a concussion and to guide return-to-play decisions for athletes. Traditional neuroimaging tests, such as brain magnetic resonance imaging, are normal in concussion, and therefore diagnosis and management are guided by reported symptoms. Some athletes will under-report symptoms to accelerate their return-to-play and others will over-report symptoms out of fear of further injury or misinterpretation of underlying conditions, such as migraine headache. Therefore, an objective measure is needed to assist in several facets of concussion management. Limited data in animal and human testing indicates that intracranial pressure increases slightly and cerebrovascular reactivity (the ability of the cerebral arteries to auto-regulate in response to changes in carbon dioxide) decreases slightly following mild traumatic brain injury. We hypothesize that a combination of ultrasonographic measurements (optic nerve sheath diameter and transcranial Doppler assessment of cerebrovascular reactivity) into a single index will allow for an accurate and non-invasive measurement of intracranial pressure and cerebrovascular reactivity, and this index will be clinically relevant and useful for guiding concussion diagnosis and management. Ultrasound is an ideal modality for the evaluation of concussion because it is portable (allowing for evaluation in many settings, such as on the playing field or in a combat zone), radiation-free (making repeat scans safe), and relatively inexpensive (resulting in nearly universal availability). This paper reviews the literature supporting our hypothesis that an ultrasonographic index can assist in the diagnosis and management of concussion, and it also presents limited data regarding the

  14. Magnetic resonance imaging and ultrasound evaluation of "healthy" joints in young subjects with severe haemophilia A.

    PubMed

    Di Minno, M N D; Iervolino, S; Soscia, E; Tosetto, A; Coppola, A; Schiavulli, M; Marrone, E; Ruosi, C; Salvatore, M; Di Minno, G

    2013-05-01

    Magnetic resonance imaging (MRI) and ultrasonography (US) are increasingly used in haemophilia A (HA) to detect early joint changes. A total of 40 clinically asymptomatic joints, never involved by bleeding events ["healthy joints" (HJ)], were evaluated by MRI and, in parallel, by US in 20 young subjects with severe HA (22.45 ± 2.72 years old; no history of arthritides, of viral infections or of inhibitors against factor VIII). The same joints were evaluated in 20 matched non-haemophilic (no-HA) subjects (mean age 23.90 ± 2.31 years, P = 0.078 vs. HA subjects). US images were obtained with specific probe positions according to validated procedures. A validated US score and progressive (P-MRI) and additive (A-MRI) MRI scores were employed for data collection and analysis. The US score was higher in HA than in no-HA subjects (3.40 ± 1.72 vs. 0.80 ± 1.10, P < 0.001). Taking into account only moderate/severe alterations, joint effusion was found in 55% of HA and in 5% of no-HA joints (P < 0.001); synovial hypertrophy was found in 20% of HA and in none of the no-HA joints; cartilage erosion was found in 30% of HA and in none of no-HA joints. MRI examinations confirmed these findings and the US score correlated with the A-MRI (r = 0.732, P < 0.001) and with the P-MRI (r = 0.598, P < 0.001) scores. MRI and US data significantly correlated as to effusion (r = 0.819, P = 0.002), synovial hypertrophy (r = 0.633, P = 0.036) and cartilage erosion (r = 0.734, P = 0.010). Despite inherent limitations, joint US examination identified subclinical abnormalities of HJ in young subjects with severe HA.

  15. Evaluation of an Automated Analysis Tool for Prostate Cancer Prediction Using Multiparametric Magnetic Resonance Imaging

    PubMed Central

    Roethke, Matthias C.; Kuru, Timur H.; Mueller-Wolf, Maya B.; Agterhuis, Erik; Edler, Christopher; Hohenfellner, Markus; Schlemmer, Heinz-Peter; Hadaschik, Boris A.

    2016-01-01

    Objective To evaluate the diagnostic performance of an automated analysis tool for the assessment of prostate cancer based on multiparametric magnetic resonance imaging (mpMRI) of the prostate. Methods A fully automated analysis tool was used for a retrospective analysis of mpMRI sets (T2-weighted, T1-weighted dynamic contrast-enhanced, and diffusion-weighted sequences). The software provided a malignancy prediction value for each image pixel, defined as Malignancy Attention Index (MAI) that can be depicted as a colour map overlay on the original images. The malignancy maps were compared to histopathology derived from a combination of MRI-targeted and systematic transperineal MRI/TRUS-fusion biopsies. Results In total, mpMRI data of 45 patients were evaluated. With a sensitivity of 85.7% (with 95% CI of 65.4–95.0), a specificity of 87.5% (with 95% CI of 69.0–95.7) and a diagnostic accuracy of 86.7% (with 95% CI of 73.8–93.8) for detection of prostate cancer, the automated analysis results corresponded well with the reported diagnostic accuracies by human readers based on the PI-RADS system in the current literature. Conclusion The study revealed comparable diagnostic accuracies for the detection of prostate cancer of a user-independent MAI-based automated analysis tool and PI-RADS-scoring-based human reader analysis of mpMRI. Thus, the analysis tool could serve as a detection support system for less experienced readers. The results of the study also suggest the potential of MAI-based analysis for advanced lesion assessments, such as cancer extent and staging prediction. PMID:27454770

  16. Evaluation of aortic stenosis by cardiovascular magnetic resonance imaging: comparison with established routine clinical techniques

    PubMed Central

    Kupfahl, C; Honold, M; Meinhardt, G; Vogelsberg, H; Wagner, A; Mahrholdt, H; Sechtem, U

    2004-01-01

    Objective: To evaluate whether direct planimetry of aortic valve area (AVA) by cardiac magnetic resonance (CMR) imaging is a reliable tool for determining the severity of aortic stenosis compared with transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), and cardiac catheterisation. Methods: 44 symptomatic patients with severe aortic stenosis were studied. By cardiac catheterisation AVA was calculated by the Gorlin equation. AVA was measured with CMR from steady state free precession (true fast imaging with steady state precession) by planimetry. AVA was also determined from TOE images by planimetry and from TTE images by the continuity equation. Results: Bland-Altman analysis evaluating intraobserver and interobserver variability showed a very small bias for both (−0.016 and 0.019, respectively; n  =  20). Bias and limits of agreement between CMR and TTE were 0.05 (−0.35, 0.44) cm2 (n  =  37), between CMR and TOE 0.02 (−0.39, 0.42) cm2 (n  =  32), and between CMR and cardiac catheterisation 0.09 (−0.30, 0.47) cm2 (n  =  36). The sensitivity and specificity of CMR to detect AVA ⩽ 0.80 cm2 measured by cardiac catheterisation was 78% and 89%, of TOE 70% and 70%, and of TTE 74% and 67%, respectively. Conclusion: CMR planimetry is highly reliable and reproducible. Further, CMR planimetry had the best sensitivity and specificity of all non-invasive methods for detecting severe aortic stenosis in comparison with cardiac catheterisation. Therefore, CMR planimetry of AVA with steady state free precession is a new powerful diagnostic tool, particularly for patients with uncertain or discrepant findings by other modalities. PMID:15253962

  17. Self-sustained oscillation limit of tube bundle resonant noise. (Phase 1: Evaluation equation of oscillation limit)

    SciTech Connect

    Nishimura, M.; Fujita, K.; Hasegawa, N.

    1995-12-01

    Self-sustained oscillation limit of tube bundle resonant noise is studied in this paper. Excited acoustic energy and dissipating one in tube bundle are derived theoretically. In the exciting stage, the acoustic field is considered to be fed back to the flow field as the inlet flow fluctuation. And the acoustic damping is considered to induce the dissipating energy. Based on the energy balance of both and dimensional analysis, a new simple evaluation equation of self-sustained oscillation limit is proposed concerning on tube bundle resonant noise. A typical experimental results are evaluated based on this equation. The results are roughly good, but this suggests that model analysis of both exciting energy and dissipating one is necessary for more precise evaluation.

  18. Evaluation of the Prostate Bed for Local Recurrence After Radical Prostatectomy Using Endorectal Magnetic Resonance Imaging

    SciTech Connect

    Liauw, Stanley L.; Pitroda, Sean P.; Eggener, Scott E.; Stadler, Walter M.; Pelizzari, Charles A.; Vannier, Michael W.; Oto, Aytek

    2013-02-01

    Purpose: To summarize the results of a 4-year period in which endorectal magnetic resonance imaging (MRI) was considered for all men referred for salvage radiation therapy (RT) at a single academic center; to describe the incidence and location of locally recurrent disease in a contemporary cohort of men with biochemical failure after radical prostatectomy (RP), and to identify prognostic variables associated with MRI findings in order to define which patients may have the highest yield of the study. Methods and Materials: Between 2007 and 2011, 88 men without clinically palpable disease underwent eMRI for detectable prostate-specific antigen (PSA) after RP. The median interval between RP and eMRI was 32 months (interquartile range, 14-57 months), and the median PSA level was 0.30 ng/mL (interquartile range, 0.19-0.72 ng/mL). Magnetic resonance imaging scans consisting of T2-weighted, diffusion-weighted, and dynamic contrast-enhanced imaging were evaluated for features consistent with local recurrence. The prostate bed was scored from 0-4, whereby 0 was definitely normal, 1 probably normal, 2 indeterminate, 3 probably abnormal, and 4 definitely abnormal. Local recurrence was defined as having a score of 3-4. Results: Local recurrence was identified in 21 men (24%). Abnormalities were best appreciated on T2-weighted axial images (90%) as focal hypointense lesions. Recurrence locations were perianastomotic (67%) or retrovesical (33%). The only risk factor associated with local recurrence was PSA; recurrence was seen in 37% of men with PSA >0.3 ng/mL vs 13% if PSA {<=}0.3 ng/mL (P<.01). The median volume of recurrence was 0.26 cm{sup 3} and was directly associated with PSA (r=0.5, P=.02). The correlation between MRI-based tumor volume and PSA was even stronger in men with positive margins (r=0.8, P<.01). Conclusions: Endorectal MRI can define areas of local recurrence after RP in a minority of men without clinical evidence of disease, with yield related to PSA

  19. Incorporating doubly resonant W ± data in a global fit of SMEFT parameters to lift flat directions

    NASA Astrophysics Data System (ADS)

    Berthier, Laure; Bjørn, Mikkel; Trott, Michael

    2016-09-01

    We calculate the double pole contribution to two to four fermion scattering through W ± currents at tree level in the Standard Model Effective Field Theory (SMEFT). We assume all fermions to be massless, U(3)5 flavour and CP symmetry. Using this result, we update the global constraint picture on SMEFT parameters including LEPII data on these charged current processes, and also modifications to our fit procedure motivated by a companion paper focused on W ± mass extractions. The fit reported is now to 177 observables and emphasises the need for a consistent inclusion of theoretical errors, and a consistent treatment of observables. Including charged current data lifts the two-fold degeneracy previously encountered in LEP (and lower energy) data, and allows us to set simultaneous constraints on 20 of 53 Wilson coefficients in the SMEFT, consistent with our assumptions. This allows the model independent inclusion of LEP data in SMEFT studies at LHC, which are projected into the SMEFT in a consistent fashion. We show how stronger constraints can be obtained by using some combinations of Wilson coefficients, when making assumptions on the UV completion of the Standard Model, or in an inconsistent analysis. We explain why strong bounds at the per-mille or sub-per-mille level on some combinations of Wilson coefficients in the Effective Lagrangian can be artificially enhanced in fits of this form in detail. This explains some of the different claims present in the literature.

  20. Modifications in Dynamic Contrast-Enhanced Magnetic Resonance Imaging Parameters After α-Particle-Emitting {sup 227}Th-trastuzumab Therapy of HER2-Expressing Ovarian Cancer Xenografts

    SciTech Connect

    Heyerdahl, Helen; Røe, Kathrine; Brevik, Ellen Mengshoel; Dahle, Jostein

    2013-09-01

    Purpose: The purpose of this study was to investigate the effect of α-particle-emitting {sup 227}Th-trastuzumab radioimmunotherapy on tumor vasculature to increase the knowledge about the mechanisms of action of {sup 227}Th-trastuzumab. Methods and Materials: Human HER2-expressing SKOV-3 ovarian cancer xenografts were grown bilaterally in athymic nude mice. Mice with tumor volumes 253 ± 36 mm{sup 3} (mean ± SEM) were treated with a single injection of either {sup 227}Th-trastuzumab at a dose of 1000 kBq/kg body weight (treated group, n=14 tumors) or 0.9% NaCl (control group, n=10 tumors). Dynamic T1-weighted contrast-enhanced magnetic resonance imaging (DCEMRI) was used to study the effect of {sup 227}Th-trastuzumab on tumor vasculature. DCEMRI was performed before treatment and 1, 2, and 3 weeks after therapy. Tumor contrast-enhancement curves were extracted voxel by voxel and fitted to the Brix pharmacokinetic model. Pharmacokinetic parameters for the tumors that underwent radioimmunotherapy were compared with the corresponding parameters of control tumors. Results: Significant increases of k{sub ep}, the rate constant of diffusion from the extravascular extracellular space to the plasma (P<.05), and k{sub el,} the rate of clearance of contrast agent from the plasma (P<.01), were seen in the radioimmunotherapy group 2 and 3 weeks after injection, compared with the control group. The product of k{sub ep} and the amplitude parameter A, associated with increased vessel permeability and perfusion, was also significantly increased in the radioimmunotherapy group 2 and 3 weeks after injection (P<.01). Conclusions: Pharmacokinetic modeling of MRI contrast-enhancement curves evidenced significant alterations in parameters associated with increased tumor vessel permeability and tumor perfusion after {sup 227}Th-trastuzumab treatment of HER2-expressing ovarian cancer xenografts.

  1. Evaluation of an active magnetic resonance tracking system for interstitial brachytherapy

    SciTech Connect

    Wang, Wei; Pan, Li; Tokuda, Junichi; Schmidt, Ehud J.; Seethamraju, Ravi T.; Dumoulin, Charles L.

    2015-12-15

    Purpose: In gynecologic cancers, magnetic resonance (MR) imaging is the modality of choice for visualizing tumors and their surroundings because of superior soft-tissue contrast. Real-time MR guidance of catheter placement in interstitial brachytherapy facilitates target coverage, and would be further improved by providing intraprocedural estimates of dosimetric coverage. A major obstacle to intraprocedural dosimetry is the time needed for catheter trajectory reconstruction. Herein the authors evaluate an active MR tracking (MRTR) system which provides rapid catheter tip localization and trajectory reconstruction. The authors assess the reliability and spatial accuracy of the MRTR system in comparison to standard catheter digitization using magnetic resonance imaging (MRI) and CT. Methods: The MRTR system includes a stylet with microcoils mounted on its shaft, which can be inserted into brachytherapy catheters and tracked by a dedicated MRTR sequence. Catheter tip localization errors of the MRTR system and their dependence on catheter locations and orientation inside the MR scanner were quantified with a water phantom. The distances between the tracked tip positions of the MRTR stylet and the predefined ground-truth tip positions were calculated for measurements performed at seven locations and with nine orientations. To evaluate catheter trajectory reconstruction, fifteen brachytherapy catheters were placed into a gel phantom with an embedded catheter fixation framework, with parallel or crossed paths. The MRTR stylet was then inserted sequentially into each catheter. During the removal of the MRTR stylet from within each catheter, a MRTR measurement was performed at 40 Hz to acquire the instantaneous stylet tip position, resulting in a series of three-dimensional (3D) positions along the catheter’s trajectory. A 3D polynomial curve was fit to the tracked positions for each catheter, and equally spaced dwell points were then generated along the curve. High

  2. Evaluation of breast cancer chemotherapy efficacy with multifractal spectrum analysis of magnetic resonance image.

    PubMed

    Li, Li; Hu, Wen-yong; Liu, Li-zhi; Pang, Ya-chun; Shao, Yuan-zhi

    2014-01-01

    Multifractal spectrum analysis of dynamic contrast enhanced (DCE) breast MR images was used to establish a new quantitative analysis method for solid tumor blood perfusion and to explore its applicability in evaluating efficacy of breast cancer chemotherapy. Five randomly selected patients suffering from newly diagnosed malignant breast nodule lesions were enrolled in this study, and four of them were treated with neoadjuvant chemotherapy. Their DCE breast MR images were collected before and after treatment. Chemotherapeutic efficacy was analyzed using international response evaluation criteria for solid tumors (RECIST). Sandbox method for statistical number density was employed to measure and calculate multifractal spectra of DCE breast MR images with spatiotemporal characteristics. Multifractal spectral data of malignant lesions before and after chemotherapy were compared. Multifractal spectra of malignant lesions show an asymmetric bell-shape. Chemotherapy efficacy was assessed to be partial remission (PR) for three patients and their multifractal spectral width significantly increased after chemotherapy while to be stable disease (SD) for other patient and of her changed slightly. Multifractal spectral width correlates with blood-supply condition of tumor lesion before and after chemotherapy, providing a potential suitable characteristic parameter for evaluating chemotherapeutic efficacy quantitatively.

  3. Quantifiable Imaging Biomarkers for Evaluation of the Posterior Cruciate Ligament Using 3-T Magnetic Resonance Imaging

    PubMed Central

    Wilson, Katharine J.; Surowiec, Rachel K.; Ho, Charles P.; Devitt, Brian M.; Fripp, Jurgen; Smith, W. Sean; Spiegl, Ulrich J.; Dornan, Grant J.; LaPrade, Robert F.

    2016-01-01

    Background: Quantitative magnetic resonance imaging (MRI) techniques, such as T2 and T2 star (T2*) mapping, have been used to evaluate ligamentous tissue in vitro and to identify significant changes in structural integrity of a healing ligament. These studies lay the foundation for a clinical study that uses quantitative mapping to evaluate ligaments in vivo, particularly the posterior cruciate ligament (PCL). To establish quantitative mapping as a clinical tool for identifying and evaluating chronic or acute PCL injuries, T2 and T2* values first must be determined for an asymptomatic population. Purpose: To quantify T2 and T2* mapping properties, including texture variables (entropy, variance, contrast, homogeneity), of the PCL in an asymptomatic population. It was hypothesized that biomarker values would be consistent throughout the ligament, as measured across 3 clinically relevant subregions (proximal, middle, and distal thirds) in the asymptomatic cohort. Study Design: Cross-sectional study; Level of evidence, 4. Methods: Unilateral knee MRI scans were acquired for 25 asymptomatic subjects with a 3.0-T MRI system using T2 and T2* mapping sequences in the sagittal plane. The PCL was manually segmented and divided into thirds (proximal, middle, and distal). Summary statistics for T2 and T2* values were calculated. Intra- and interrater reliability was assessed across 3 raters to 2 time points. Results: The asymptomatic PCL cohort had mean T2 values of 36.7, 29.2, and 29.6 ms in the distal, middle, and proximal regions, respectively. The distal PCL exhibited significantly higher mean, variance, and contrast and lower homogeneity of T2 values than the middle and proximal subregions (P < .05). T2* results exhibited substantial positive skew and were therefore presented as median and quartile (Q) values. Median T2* values were 7.3 ms (Q1-Q3, 6.8-8.9 ms), 7.3 ms (Q1-Q3, 7.0-8.5 ms), and 7.3 ms (Q1-Q3, 6.4-8.2 ms) in the distal, middle, and proximal subregions

  4. Evaluation of the toxic and genotoxic potential of acid mine drainage using physicochemical parameters and bioassays.

    PubMed

    Netto, E; Madeira, R A; Silveira, F Z; Fiori, M A; Angioleto, E; Pich, C T; Geremias, R

    2013-05-01

    Carboniferous activity generates acid mine drainage (AMD) which is capable of unleashing toxic effects on the exposed biota. The aim of this study was to evaluate the toxic and genotoxic potential of untreated-AMD and AMD treated with calcinated sediment, using physicochemical parameters and bioassays. Results revealed that untreated-AMD presented low pH values and elevated concentrations of the metals Fe, Al, Mn, Zn and Cu. High acute toxicity was observed in Artemia sp. and Daphnia magna, and sub-chronic toxicity and genotoxicity in Allium cepa L. as well as scission of plasmid DNA exposed to untreated-AMD. Treatment of AMD with calcinated sediment promoted the reduction of acidity and the removal of metals, as well as a reduction in toxic and genotoxic effects. In conclusion, the calcinated sediment can be used as an alternative AMD treatment.

  5. Calculation of parameters for inspection planning and evaluation: mixed-oxide fuel fabrication facilities

    SciTech Connect

    Reardon, P.T.; Mullen, M.F.

    1982-08-01

    As part of Task C.35 (Calculation of Parameters for Inspection Planning and Evaluation) of the US Program of Technical Assistance to IAEA Safeguards, Pacific Northwest Laboratory has performed some quantitative analyses of IAEA inspection activities for mixed-oxide fuel fabrication facilities. There were four distinct efforts involved in this task. These were as follows: show the effect on a material balance verification of using two variables measurement methods in some strata; perform additional calculations for the reference facility described in STR-89; modify the INSPECT computer programs to be used as an after-inspection analysis tool, as well as a preinspection planning tool; provide written comments and explantations of text and graphs of the first draft of STR-89, Safeguards Considerations for Mixed-Oxide Fuel Element Fabrication Facilities, by W. Bahm, T. Shea, and D. Tolchenkov, System Studies Section, IAEA.

  6. Evaluation of the toxic and genotoxic potential of acid mine drainage using physicochemical parameters and bioassays.

    PubMed

    Netto, E; Madeira, R A; Silveira, F Z; Fiori, M A; Angioleto, E; Pich, C T; Geremias, R

    2013-05-01

    Carboniferous activity generates acid mine drainage (AMD) which is capable of unleashing toxic effects on the exposed biota. The aim of this study was to evaluate the toxic and genotoxic potential of untreated-AMD and AMD treated with calcinated sediment, using physicochemical parameters and bioassays. Results revealed that untreated-AMD presented low pH values and elevated concentrations of the metals Fe, Al, Mn, Zn and Cu. High acute toxicity was observed in Artemia sp. and Daphnia magna, and sub-chronic toxicity and genotoxicity in Allium cepa L. as well as scission of plasmid DNA exposed to untreated-AMD. Treatment of AMD with calcinated sediment promoted the reduction of acidity and the removal of metals, as well as a reduction in toxic and genotoxic effects. In conclusion, the calcinated sediment can be used as an alternative AMD treatment. PMID:23518284

  7. Calculation of parameters for inspection planning and evaluation: low enriched uranium conversion and fuel fabrication facilities

    SciTech Connect

    Reardon, P.T.; Mullen, M.F.; Harms, N.L.

    1981-02-01

    As part of Task C.35 (Calculation of Parameters for Inspection Planning and Evaluation) of the US Program of Technical Assistance to IAEA Safeguards, Pacific Northwest Laboratory has performed some quantitative analyses of IAEA inspection activities at low-enriched uranium (LEU) conversion and fuel fabrication facilities. This report presents the results and conclusions of those analyses. Implementation of IAEA safeguards at LEU conversion and fuel fabrication facilities must take into account a variety of practical problems and constraints. One of the key concerns is the problem of flow verification, especially product verification. The objective of this report is to help put the problem of flow verification in perspective by presenting the results of some specific calculations of inspection effort and probability of detection for various product measurement strategies. In order to provide quantitative information about the advantages and disadvantages of the various strategies, eight specific cases were examined.

  8. Evaluation of higher order statistics parameters for multi channel sEMG using different force levels.

    PubMed

    Naik, Ganesh R; Kumar, Dinesh K

    2011-01-01

    The electromyograpy (EMG) signal provides information about the performance of muscles and nerves. The shape of the muscle signal and motor unit action potential (MUAP) varies due to the movement of the position of the electrode or due to changes in contraction level. This research deals with evaluating the non-Gaussianity in Surface Electromyogram signal (sEMG) using higher order statistics (HOS) parameters. To achieve this, experiments were conducted for four different finger and wrist actions at different levels of Maximum Voluntary Contractions (MVCs). Our experimental analysis shows that at constant force and for non-fatiguing contractions, probability density functions (PDF) of sEMG signals were non-Gaussian. For lesser MVCs (below 30% of MVC) PDF measures tends to be Gaussian process. The above measures were verified by computing the Kurtosis values for different MVCs.

  9. Evaluation of crack parameters by a nonlinear frequency-mixing laser ultrasonics method.

    PubMed

    Mezil, Sylvain; Chigarev, Nikolay; Tournat, Vincent; Gusev, Vitalyi

    2016-07-01

    The local evaluation of several parameters of a crack is realized with a nonlinear laser ultrasonic method. The method is based on the sample excitation by two laser beams, independently intensity modulated at two cyclic frequencies ωH and ωL (ωH≫ωL) and on the detection of nonlinear frequency-mixing ultrasonic components at frequencies ωH±nωL (n an integer). Frequency-mixing is a nonlinear process originating from the modulation of the crack state at low frequency ωL by laser-induced thermo-elastic stresses, which causes in turn the modulation of the acoustic waves at frequency ωH reflected/transmitted by the crack. We carry experiments with increasing laser power and observe a non-monotonous variation in the amplitude of up to 6 nonlinear sidelobes. We also improve a previously introduced theoretical model which leads to interpreting the experimental observations by the combined action on the crack of the thermo-elastic waves at low frequency ωL and of the stationary thermo-elastic stresses at ω=0. The latter are induced by the average laser power absorbed by the sample. While thermo-elastic wave can periodically modulate the parameters of the crack up to its periodic opening/closing, the stationary heating could cause complete local closure of the crack. By fitting the experimental amplitude evolutions for all monitored sidelobes with the theoretically predicted ones, various local parameters of the crack are extracted, including its local width and effective rigidity.

  10. Evaluating the Surface Topography of Pyrolytic Carbon Finger Prostheses through Measurement of Various Roughness Parameters.

    PubMed

    Naylor, Andrew; Talwalkar, Sumedh C; Trail, Ian A; Joyce, Thomas J

    2016-01-01

    The articulating surfaces of four different sizes of unused pyrolytic carbon proximal interphalangeal prostheses (PIP) were evaluated though measuring several topographical parameters using a white light interferometer: average roughness (Sa); root mean-square roughness (Sq); skewness (Ssk); and kurtosis (Sku). The radii of the articulating surfaces were measured using a coordinate measuring machine, and were found to be: 2.5, 3.3, 4.2 and 4.7 mm for proximal, and 4.0, 5.1, 5.6 and 6.3 mm for medial components. ANOVA was used to assess the relationship between the component radii and each roughness parameter. Sa, Sq and Ssk correlated negatively with radius (p = 0.001, 0.001, 0.023), whilst Sku correlated positively with radius (p = 0.03). Ergo, the surfaces with the largest radii possessed the better topographical characteristics: low roughness, negative skewness, high kurtosis. Conversely, the surfaces with the smallest radii had poorer topographical characteristics.

  11. Introduction of Environmentally Degradable Parameters to Evaluate the Biodegradability of Biodegradable Polymers

    PubMed Central

    Yang, Chao; Song, Cunjiang; Geng, Weitao; Li, Qiang; Wang, Yuanyuan; Kong, Meimei; Wang, Shufang

    2012-01-01

    Environmentally Degradable Parameter (EdK) is of importance in the describing of biodegradability of environmentally biodegradable polymers (BDPs). In this study, a concept EdK was introduced. A test procedure of using the ISO 14852 method and detecting the evolved carbon dioxide as an analytical parameter was developed, and the calculated EdK was used as an indicator for the ultimate biodegradability of materials. Starch and polyethylene used as reference materials were defined as the EdK values of 100 and 0, respectively. Natural soil samples were inoculated into bioreactors, followed by determining the rates of biodegradation of the reference materials and 15 commercial BDPs over a 2-week test period. Finally, a formula was deduced to calculate the value of EdK for each material. The EdK values of the tested materials have a positive correlation to their biodegradation rates in the simulated soil environment, and they indicated the relative biodegradation rate of each material among all the tested materials. Therefore, the EdK was shown to be a reliable indicator for quantitatively evaluating the potential biodegradability of BDPs in the natural environment. PMID:22675455

  12. A comparative evaluation of semen parameters in pre- and post-Hurricane Katrina human population

    PubMed Central

    Baran, Caner; Hellstrom, Wayne J; Sikka, Suresh C

    2015-01-01

    A natural disaster leading to accumulation of environmental contaminants may have substantial effects on the male reproductive system. Our aim was to compare and assess semen parameters in a normospermic population residing in the Southern Louisiana, USA area pre- and post-Hurricane Katrina. We retrospectively evaluated semen analyses data (n = 3452) of 1855 patients who attended the Tulane University Andrology/Fertility Clinic between 1999 and 2013. The study inclusion criteria were men whose semen analyses showed ≥ 1.5 ml volume; ≥15 million ml-1 sperm concentration; ≥39 million total sperm count; ≥40% motility; >30% morphology, with an abstinence interval of 2–7 days. After the inclusion criteria applied to the population, 367 normospermic patients were included in the study. Descriptive statistics and group-based analyses were performed to interpret the differences between the pre-Katrina (Group 1, 1999–2005) and the post-Katrina (Group 2, 2006–2013) populations. There were significant differences in motility, morphology, number of white blood cell, immature germ cell count, pH and presence of sperm agglutination, but surprisingly there were no significant differences in sperm count between the two populations. This long-term comparative analysis further documents that a major natural disaster with its accompanied environmental issues can influence certain semen parameters (e.g., motility and morphology) and, by extension, fertility potential of the population of such areas. PMID:25677132

  13. A comparative evaluation of semen parameters in pre- and post-Hurricane Katrina human population.

    PubMed

    Baran, Caner; Hellstrom, Wayne J; Sikka, Suresh C

    2015-01-01

    A natural disaster leading to accumulation of environmental contaminants may have substantial effects on the male reproductive system. Our aim was to compare and assess semen parameters in a normospermic population residing in the Southern Louisiana, USA area pre- and post-Hurricane Katrina. We retrospectively evaluated semen analyses data (n = 3452) of 1855 patients who attended the Tulane University Andrology/Fertility Clinic between 1999 and 2013. The study inclusion criteria were men whose semen analyses showed ≥ 1.5 ml volume; ≥15 million ml -1 sperm concentration; ≥39 million total sperm count; ≥40% motility; >30% morphology, with an abstinence interval of 2-7 days. After the inclusion criteria applied to the population, 367 normospermic patients were included in the study. Descriptive statistics and group-based analyses were performed to interpret the differences between the pre-Katrina (Group 1, 1999-2005) and the post-Katrina (Group 2, 2006-2013) populations. There were significant differences in motility, morphology, number of white blood cell, immature germ cell count, pH and presence of sperm agglutination, but surprisingly there were no significant differences in sperm count between the two populations. This long-term comparative analysis further documents that a major natural disaster with its accompanied environmental issues can influence certain semen parameters (e.g., motility and morphology) and, by extension, fertility potential of the population of such areas. PMID:25677132

  14. A comparative evaluation of semen parameters in pre- and post-Hurricane Katrina human population.

    PubMed

    Baran, Caner; Hellstrom, Wayne J; Sikka, Suresh C

    2015-01-01

    A natural disaster leading to accumulation of environmental contaminants may have substantial effects on the male reproductive system. Our aim was to compare and assess semen parameters in a normospermic population residing in the Southern Louisiana, USA area pre- and post-Hurricane Katrina. We retrospectively evaluated semen analyses data (n = 3452) of 1855 patients who attended the Tulane University Andrology/Fertility Clinic between 1999 and 2013. The study inclusion criteria were men whose semen analyses showed ≥ 1.5 ml volume; ≥15 million ml -1 sperm concentration; ≥39 million total sperm count; ≥40% motility; >30% morphology, with an abstinence interval of 2-7 days. After the inclusion criteria applied to the population, 367 normospermic patients were included in the study. Descriptive statistics and group-based analyses were performed to interpret the differences between the pre-Katrina (Group 1, 1999-2005) and the post-Katrina (Group 2, 2006-2013) populations. There were significant differences in motility, morphology, number of white blood cell, immature germ cell count, pH and presence of sperm agglutination, but surprisingly there were no significant differences in sperm count between the two populations. This long-term comparative analysis further documents that a major natural disaster with its accompanied environmental issues can influence certain semen parameters (e.g., motility and morphology) and, by extension, fertility potential of the population of such areas.

  15. Evaluating the Surface Topography of Pyrolytic Carbon Finger Prostheses through Measurement of Various Roughness Parameters

    PubMed Central

    Naylor, Andrew; Talwalkar, Sumedh C.; Trail, Ian A.; Joyce, Thomas J.

    2016-01-01

    The articulating surfaces of four different sizes of unused pyrolytic carbon proximal interphalangeal prostheses (PIP) were evaluated though measuring several topographical parameters using a white light interferometer: average roughness (Sa); root mean-square roughness (Sq); skewness (Ssk); and kurtosis (Sku). The radii of the articulating surfaces were measured using a coordinate measuring machine, and were found to be: 2.5, 3.3, 4.2 and 4.7 mm for proximal, and 4.0, 5.1, 5.6 and 6.3 mm for medial components. ANOVA was used to assess the relationship between the component radii and each roughness parameter. Sa, Sq and Ssk correlated negatively with radius (p = 0.001, 0.001, 0.023), whilst Sku correlated positively with radius (p = 0.03). Ergo, the surfaces with the largest radii possessed the better topographical characteristics: low roughness, negative skewness, high kurtosis. Conversely, the surfaces with the smallest radii had poorer topographical characteristics. PMID:27089375

  16. Evaluation of earthquake parameters used in the Indonesian Tsunami Early Warning System

    NASA Astrophysics Data System (ADS)

    Madlazim; Prastowo, Tjipto

    2016-02-01

    Twenty-two of a total of 30 earthquake events reported by the Indonesian Agency for Geophysics, Climatology and Meteorology during the time period 2007-2010 were falsely issued as tsunamigenic by the Indonesian Tsunami Early Warning System (Ina-TEWS). These 30 earthquakes were of different magnitudes and occurred in different locations. This study aimed to evaluate the performance of the Ina-TEWS using common earthquake parameters, including the earthquake magnitude, origin time, depth, and epicenter. In total, 298 datasets assessed by the Ina-TEWS and the global centroid moment tensor (CMT) method were assessed. The global CMT method is considered by almost all seismologists to be a reference for the determination of these parameters as they have been proved to be accurate. It was found that the earthquake magnitude, origin time, and depth provided by the Ina-TEWS were significantly different from those given in the global CMT catalog, whereas the latitude and longitude positions of the events provided by both tsunami assessment systems were coincident. The performance of the Ina-TEWS, particularly in terms of accuracy, remains questionable and needs to be improved.

  17. Evaluation and optimisation of propofol pharmacokinetic parameters in cats for target-controlled infusion.

    PubMed

    Cattai, A; Pilla, T; Cagnardi, P; Zonca, A; Franci, P

    2016-05-14

    The aim of this study was to develop and evaluate a pharmacokinetic model-driven infusion of propofol in premedicated cats. In a first step, propofol (10 mg/kg) was administered intravenously over 60 seconds to induce anaesthesia for the elective neutering of seven healthy cats, premedicated intramuscularly with 0.3 mg/kg methadone, 0.01 mg/kg medetomidine and 2 mg/kg ketamine. Venous blood samples were collected over 240 minutes, and propofol concentrations were measured via a validated high-performance liquid chromatography assay. Selected pharmacokinetic parameters, determined by a three-compartment open linear model, were entered into a computer-controlled infusion pump (target-controlled infusion-1 (TCI-1)). In a second step, TCI-1 was used to induce and maintain general anaesthesia in nine cats undergoing neutering. Predicted and measured plasma concentrations of propofol were compared at specific time points. In a third step, the pharmacokinetic parameters were modified according to the results from the use of TCI-1 and were evaluated again in six cats. For this TCI-2 group, the median values of median performance error and median absolute performance error were -1.85 per cent and 29.67 per cent, respectively, indicating that it performed adequately. Neither hypotension nor respiratory depression was observed during TCI-1 and TCI-2. Mean anaesthesia time and time to extubation in the TCI-2 group were 73.90 (±20.29) and 8.04 (±5.46) minutes, respectively. PMID:27044652

  18. Evaluation of cesium-137 conversion models and parameter sensitivity for erosion estimation.

    PubMed

    John Zhang, X C; Zhang, G H; Wei, X; Guan, Y H

    2015-05-01

    The Cs technique has been widely used to provide soil redistribution estimates since the 1970s. However, most Cs-conversion models remain theoretical and largely unvalidated. Our objectives were to validate the four widely used conversion models, examine model parameter sensitivity, and evaluate the potential of using kriging to improve soil redistribution estimation. Soil loss was measured from a 1.6-ha plot since 1978. Winter wheat ( L.) was grown primarily under conventional tillage. Soil samples in a 10-m grid were taken from the plot to estimate the Cs inventory. Soil redistribution rates were estimated using four models and were further interpolated using ordinary kriging. The parameter sensitivity analyses at the 95% confidence limits showed that reference inventory had the most impact on estimated water erosion, followed by particle size correction for erosion and tillage depth, with minimal impacts from mass depth, bulk density, and particle size correction for deposition. Compared with the measured water erosion, the relative errors of the mean net water erosion estimates across the entire plot without and with kriging were 28 and -17% for the proportional model (PM), 141 and 106% for the simplified mass balance model, 133 and 100% for the improved mass balance model (MBM2), and 109% for the extended MBM2 with tillage erosion (MBM3). Results indicated that the PM performed better than the mass balance models under the study conditions and that kriging improved mean soil redistribution estimates. However, the full potential of the MBM2 and MBM3 needs to be further evaluated under conditions where loss of newly deposited Cs exists.

  19. Evaluating the safety of intracameral bevacizumab application using oxidative stress and apoptotic parameters in corneal tissue

    PubMed Central

    Akal, Ali; Ulas, Turgay; Goncu, Tugba; Guldur, Muhammet Emin; Kocarslan, Sezen; Taskin, Abdullah; Sezen, Hatice; Ozkan, Kudret; Yilmaz, Omer Faruk; Buyukhatipoglu, Hakan

    2015-01-01

    AIM To investigate the possible effects of intracameral bevacizumab on oxidative stress parameters and apoptosis in corneal tissue. METHODS In total, 30 rats were assigned randomly into the following three groups of 10 rats each: a sham group (Group 1; n=10), a control group [Group 2; balanced salt solution (BSS) was administered at 0.01 mL; n=10], and a treatment group (Group 3; bevacizumab was administered at 0.25 mg/0.01 mL; n=10). The total antioxidant status (TAS) and the total oxidant status (TOS) in the corneal tissue and blood samples were measured, and the oxidative stress index (OSI) was calculated. Additionally, corneal tissue histopathology was evaluated for caspase-3 and -8 staining and apoptotic activity. RESULTS In the blood samples, the TAS, TOS, and OSI levels were not significantly different (all P>0.05). Compared with the sham and control groups, the TOS and OSI levels in the corneal tissues were significantly different in the bevacizumab group (all P<0.05). No statistically significant differences were observed between the sham and control groups (all P>0.05). However, compared with the sham and control groups, greater immunohistochemical staining for caspases-3 and -8 and an elevated level of apoptotic activity were observed in the bevacizumab group. CONCLUSION This study revealed that intracameral bevacizumab injections seemed to be systemically safe but may have elicited local toxic effects in the corneal tissue, as indicated by the oxidative stress parameters and histopathological evaluations. PMID:26309865

  20. Fiber-optic sensors for monitoring patient physiological parameters: a review of applicable technologies and relevance to use during magnetic resonance imaging procedures

    NASA Astrophysics Data System (ADS)

    Dziuda, Łukasz

    2015-01-01

    The issues involved with recording vital functions in the magnetic resonance imaging (MRI) environment using fiber-optic sensors are considered in this paper. Basic physiological parameters, such as respiration and heart rate, are fundamental for predicting the risk of anxiety, panic, and claustrophobic episodes in patients undergoing MRI examinations. Electronic transducers are generally hazardous to the patient and are prone to erroneous operation in heavily electromagnetically penetrated MRI environments; however, nonmetallic fiber-optic sensors are inherently immune to electromagnetic effects and will be crucial for acquiring the above-mentioned physiological parameters. Forty-seven MRI-tested or potentially MRI-compatible sensors have appeared in the literature over the last 20 years. The author classifies these sensors into several categories and subcategories, depending on the sensing element placement, method of application, and measurand type. The author includes five in-house-designed fiber Bragg grating based sensors and shares experience in acquiring physiological measurements during MRI scans. This paper aims to systematize the knowledge of fiber-optic techniques for recording life functions and to indicate the current directions of development in this area.

  1. Fiber-optic sensors for monitoring patient physiological parameters: a review of applicable technologies and relevance to use during magnetic resonance imaging procedures.

    PubMed

    Dziuda, Łukasz

    2015-01-01

    The issues involved with recording vital functions in the magnetic resonance imaging (MRI) environment using fiber-optic sensors are considered in this paper. Basic physiological parameters, such as respiration and heart rate, are fundamental for predicting the risk of anxiety, panic, and claustrophobic episodes in patients undergoing MRI examinations. Electronic transducers are generally hazardous to the patient and are prone to erroneous operation in heavily electromagnetically penetrated MRI environments; however, nonmetallic fiber-optic sensors are inherently immune to electromagnetic effects and will be crucial for acquiring the above-mentioned physiological parameters. Forty-seven MRI-tested or potentially MRI-compatible sensors have appeared in the literature over the last 20 years. The author classifies these sensors into several categories and subcategories, depending on the sensing element placement, method of application, and measure and type. The author includes five in-house-designed fiber Bragg grating based sensors and shares experience in acquiring physiological measurements during MRI scans. This paper aims to systematize the knowledge of fiber-optic techniques for recording life functions and to indicate the current directions of development in this area. PMID:25594625

  2. An analytical method for estimating the {sup 14}N nuclear quadrupole resonance parameters of organic compounds with complex free induction decays for radiation effects studies

    SciTech Connect

    Iselin, L.H.

    1992-12-31

    The use of {sup 14}N nuclear quadrupole resonance (NQR) as a radiation dosimetry tool has only recently been explored. An analytical method for analyzing {sup 14}N NQR complex free induction decays is presented with the background necessary to conduct pulsed NQR experiments. The {sup 14}N NQR energy levels and possible transitions are derived in step-by-step detail. The components of a pulsed NQR spectrometer are discussed along with the experimental techniques for conducting radiation effects experiments using the spectrometer. Three data analysis techniques -- the power spectral density Fourier transform, state space singular value decomposition (HSVD), and nonlinear curve fitting (using the downhill simplex method of global optimization and the Levenberg-Marquart method) -- are explained. These three techniques are integrated into an analytical method which uses these numerical techniques in this order to determine the physical NQR parameters. Sample data sets of urea and guanidine sulfate data are used to demonstrate how these methods can be employed to analyze both simple and complex free induction decays. By determining baseline values for biologically significant organics, radiation effects on the NQR parameters can be studied to provide a link between current radiation dosimetry techniques and the biological effects of radiation.

  3. Evaluation of Angiographic and Technical Aspects of Carotid Stenting with Diffusion-Weighted Magnetic Resonance Imaging

    SciTech Connect

    Blasel, Stella Hattingen, Elke; Berkefeld, Joachim; Kurre, Wiebke; Morawe, Gerald; Zanella, Friedhelm; Rochemont, Richard Du Mesnil de

    2009-07-15

    The detection of clinically silent ischemic lesions on postprocedural diffusion-weighted magnetic resonance images has become a preferred method for the description of embolic risks. The purpose of this single-center study was to evaluate whether diffusion-weighted imaging (DWI) could determine material related or technical risk factors of filter-protected carotid stenting. Eighty-four patients with symptomatic severe ({>=}60%) carotid artery stenoses received filter-protected carotid stenting. Standard DWI (b = 1000) was performed within 48 h before and after carotid stenting. The occurrence and load of new postinterventional DWI lesions were assessed. Multivariate analysis was performed to determine risk factors associated with DWI lesions, with emphasis on technical factors such as use of different access devices (guiding catheter method vs. long carotid sheath method), type of stent (open-cell nitinol stent vs. closed-cell Wallstent), and protective device (filters with 80-{mu}m vs. 110-120-{mu}m pore size). Markers for generalized atherosclerosis and for degree and site of stenosis were assessed to allow comparison of adequate risk profiles. Access, protective device, and stent type were not significantly associated with new embolic DWI lesions when we compared patients with equivalent risk profiles (long carotid sheath method 48% [11 of 23] vs. guiding catheter method 44% [27 of 61], Wallstent 47% [15 of 32] vs. nitinol stent 44% [23 of 52], and small pore size filter 61% [11 of 18] vs. large pore size filter 41% [27 of 66]). Single-center DWI studies with a moderate number of cases are inadequate for proper assessment of the embolic risk of technical- or material-related risk factors in carotid stenting. Larger multicenter studies with more cases are needed.

  4. Further Evaluation of the Neutron Resonance Transmission Analysis (NRTA) Technique for Assaying Plutonium in Spent Fuel

    SciTech Connect

    J. W. Sterbentz; D. L. Chichester

    2011-09-01

    This is an end-of-year report (Fiscal Year (FY) 2011) for the second year of effort on a project funded by the National Nuclear Security Administration's Office of Nuclear Safeguards (NA-241). The goal of this project is to investigate the feasibility of using Neutron Resonance Transmission Analysis (NRTA) to assay plutonium in commercial light-water-reactor spent fuel. This project is part of a larger research effort within the Next-Generation Safeguards Initiative (NGSI) to evaluate methods for assaying plutonium in spent fuel, the Plutonium Assay Challenge. The second-year goals for this project included: (1) assessing the neutron source strength needed for the NRTA technique, (2) estimating count times, (3) assessing the effect of temperature on the transmitted signal, (4) estimating plutonium content in a spent fuel assembly, (5) providing a preliminary assessment of the neutron detectors, and (6) documenting this work in an end of the year report (this report). Research teams at Los Alamos National Laboratory (LANL), Lawrence Berkeley National Laboratory (LBNL), Pacific Northwest National Laboratory (PNNL), and at several universities are also working to investigate plutonium assay methods for spent-fuel safeguards. While the NRTA technique is well proven in the scientific literature for assaying individual spent fuel pins, it is a newcomer to the current NGSI efforts studying Pu assay method techniques having just started in March 2010; several analytical techniques have been under investigation within this program for two to three years or more. This report summarizes work performed over a nine month period from January-September 2011 and is to be considered a follow-on or add-on report to our previous published summary report from December 2010 (INL/EXT-10-20620).

  5. Aerobic Training after Myocardial Infarction: Remodeling Evaluated by Cardiac Magnetic Resonance

    PubMed Central

    Izeli, Nataly Lino; dos Santos, Aurélia Juliana; Crescêncio, Júlio César; Gonçalves, Ana Clara Campagnolo Real; Papa, Valéria; Marques, Fabiana; Pazin-Filho, Antônio; Gallo-Júnior, Lourenço; Schmidt, André

    2016-01-01

    Background Numerous studies show the benefits of exercise training after myocardial infarction (MI). Nevertheless, the effects on function and remodeling are still controversial. Objectives To evaluate, in patients after (MI), the effects of aerobic exercise of moderate intensity on ventricular remodeling by cardiac magnetic resonance imaging (CMR). Methods 26 male patients, 52.9 ± 7.9 years, after a first MI, were assigned to groups: trained group (TG), 18; and control group (CG), 8. The TG performed supervised aerobic exercise on treadmill twice a week, and unsupervised sessions on 2 additional days per week, for at least 3 months. Laboratory tests, anthropometric measurements, resting heart rate (HR), exercise test, and CMR were conducted at baseline and follow-up. Results The TG showed a 10.8% reduction in fasting blood glucose (p = 0.01), and a 7.3-bpm reduction in resting HR in both sitting and supine positions (p < 0.0001). There was an increase in oxygen uptake only in the TG (35.4 ± 8.1 to 49.1 ± 9.6 mL/kg/min, p < 0.0001). There was a statistically significant decrease in the TG left ventricular mass (LVmass) (128.7 ± 38.9 to 117.2 ± 27.2 g, p = 0.0032). There were no statistically significant changes in the values of left ventricular end-diastolic volume (LVEDV) and ejection fraction in the groups. The LVmass/EDV ratio demonstrated a statistically significant positive remodeling in the TG (p = 0.015). Conclusions Aerobic exercise of moderate intensity improved physical capacity and other cardiovascular variables. A positive remodeling was identified in the TG, where a left ventricular diastolic dimension increase was associated with LVmass reduction. PMID:26959403

  6. Preoperative evaluation of the ulnar collateral ligament by magnetic resonance imaging and computed tomography arthrography. Evaluation in 25 baseball players with surgical confirmation.

    PubMed

    Timmerman, L A; Schwartz, M L; Andrews, J R

    1994-01-01

    A prospective study was completed on 25 baseball players with medial side elbow pain. They were evaluated preoperatively with both computed tomography arthrogram and magnetic resonance imaging examinations of the elbow to assess the ulnar collateral ligament. At surgery, 16 of 25 patients had an abnormal ulnar collateral ligament and 9 patients had a normal ulnar collateral ligament. The computed tomography arthrogram detected abnormalities in 12 of the 14 patients with ulnar collateral ligament tearing (sensitivity, 86%). The magnetic resonance imaging scan indicated abnormalities in 8 of 14 patients (sensitivity, 57%). The specificity of the computed tomography arthrogram was 91% and the magnetic resonance imaging was 100%. A newly described "T-sign" was seen on the computed tomography arthrogram in the patients with an undersurface tear of the ulnar collateral ligament. This represented the dye leaking around the detachment of the ulnar collateral ligament from its bony insertion but remaining contained within the intact superficial layer of the ulnar collateral ligament and capsule. Both the computed tomography arthrogram and the magnetic resonance imaging scan were accurate in diagnosing a complete tear of the ulnar collateral ligament preoperatively in all cases. The main advantage of the computed tomography arthrogram was in evaluating the partial undersurface tear.

  7. In vivo quantitative evaluation of vascular parameters for angiogenesis based on sparse principal component analysis and aggregated boosted trees

    NASA Astrophysics Data System (ADS)

    Zhao, Fengjun; Liu, Junting; Qu, Xiaochao; Xu, Xianhui; Chen, Xueli; Yang, Xiang; Cao, Feng; Liang, Jimin; Tian, Jie

    2014-12-01

    To solve the multicollinearity issue and unequal contribution of vascular parameters for the quantification of angiogenesis, we developed a quantification evaluation method of vascular parameters for angiogenesis based on in vivo micro-CT imaging of hindlimb ischemic model mice. Taking vascular volume as the ground truth parameter, nine vascular parameters were first assembled into sparse principal components (PCs) to reduce the multicolinearity issue. Aggregated boosted trees (ABTs) were then employed to analyze the importance of vascular parameters for the quantification of angiogenesis via the loadings of sparse PCs. The results demonstrated that vascular volume was mainly characterized by vascular area, vascular junction, connectivity density, segment number and vascular length, which indicated they were the key vascular parameters for the quantification of angiogenesis. The proposed quantitative evaluation method was compared with both the ABTs directly using the nine vascular parameters and Pearson correlation, which were consistent. In contrast to the ABTs directly using the vascular parameters, the proposed method can select all the key vascular parameters simultaneously, because all the key vascular parameters were assembled into the sparse PCs with the highest relative importance.

  8. Magnetic Resonance Imaging (MRI) Evaluation of Developmental Delay in Pediatric Patients

    PubMed Central

    Syed, Naziya P.; Murthy, G.S.N.; Nori, Madhavi; Abkari, Anand; Pooja, B.K.; Venkateswarlu, J.

    2015-01-01

    Introduction: Developmental delay is defined as significant delay in one or more developmental domains. Magnetic Resonance Imaging (MRI) is the best modality to investigate such patients. Evaluation of a child with developmental delay is important not only because it allows early diagnosis and treatment but also helpful for parental counseling regarding the outcome of their child and to identify any possible risk of recurrence in the siblings. Thus this study was undertaken to evaluate the developmental delay in Indian children which will help the clinicians in providing an estimation of the child’s ultimate developmental potential and organize specific treatment requirement and also relieve parental apprehension. Aims and Objectives: To study the prevalence of normal and abnormal MRI in pediatric patients presenting with developmental delay and further categorize the abnormal MRI based on its morphological features. Materials and Methods: It is a prospective, observational & descriptive study of MRI Brain in 81 paediatric patients (46 Males and 35 Females), aged between three months to 12 years; presenting with developmental delay in Deccan College of Medical Sciences, Hyderabad; over a period of three years (Sept 2011 to Sept 2014). MRI brain was done on 1.5T Siemens Magnetom Essenza & 0.35T Magnetom C with appropriate sequences and planes after making the child sleep/sedated/ anesthetized. Various anatomical structures like Ventricles, Corpus callosum, etc were systematically assessed. The MRI findings were divided into various aetiological subgroups. Results: Normal MRI findings were seen in 32% cases and 68% had abnormal findings of which the proportion of Traumatic/ Neurovascular Diseases, Congenital & Developmental, Metabolic and Degenerative, neoplastic and non specific were 31%, 17%, 10%, 2.5% and 7.5% respectively. The ventricles and white matter mainly the corpus callosum were the most commonly affected anatomical structures. The diagnostic yield was

  9. Interference effect in the dipole and nondipole anisotropy parameters of the Kr 4p photoelectrons in the vicinity of the Kr (3d){sup -1{yields}}np resonant excitations

    SciTech Connect

    Ricz, S.; Ricsoka, T.; Holste, K.; Borovik, A. Jr.; Bernhardt, D.; Schippers, S.; Mueller, A.; Koever, A.; Varga, D.

    2010-04-15

    The angular distribution of the Kr 4p photoelectrons was investigated in the photon energy range of the (3d){sup -1{yields}}np resonant excitations. The experimental dipole ({beta}) and nondipole ({gamma} and {delta}) anisotropy parameters were determined for the spin-orbit components of the Kr 4p shell. A simple theoretical model was developed for the description of the photoionization and excitation processes. An interference effect was observed between the direct photoionization and the resonant excitation participator Auger decay processes in the photon energy dependence of the experimental anisotropy parameters.

  10. Quantitative evaluation of ozone and selected climate parameters in a set of EMAC simulations

    NASA Astrophysics Data System (ADS)

    Righi, M.; Eyring, V.; Gottschaldt, K.-D.; Klinger, C.; Frank, F.; Jöckel, P.; Cionni, I.

    2014-10-01

    Four simulations with the ECHAM/MESSy Atmospheric Chemistry (EMAC) model have been evaluated with the Earth System Model Validation Tool (ESMValTool) to identify differences in simulated ozone and selected climate parameters that resulted from (i) different setups of the EMAC model (nudged vs. free-running) and (ii) different boundary conditions (emissions, sea surface temperatures (SSTs) and sea-ice concentrations (SICs)). To assess the relative performance of the simulations, quantitative performance metrics are calculated consistently for the climate parameters and ozone. This is important for the interpretation of the evaluation results since biases in climate can impact on biases in chemistry and vice versa. The observational datasets used for the evaluation include ozonesonde and aircraft data, meteorological reanalyses and satellite measurements. The results from a previous EMAC evaluation of a model simulation with weak nudging towards realistic meteorology in the troposphere have been compared to new simulations with different model setups and updated emission datasets in free-running timeslice and nudged Quasi Chemistry-Transport Model (QCTM) mode. The latter two configurations are particularly important for chemistry-climate projections and for the quantification of individual sources (e.g. transport sector) that lead to small chemical perturbations of the climate system, respectively. With the exception of some specific features which are detailed in this study, no large differences that could be related to the different setups of the EMAC simulations (nudged vs. free-running) were found, which offers the possibility to evaluate and improve the overall model with the help of shorter nudged simulations. The main differences between the two setups is a better representation of the tropospheric and stratospheric temperature in the nudged simulations, which also better reproduce stratospheric water vapour concentrations, due to the improved simulation of

  11. Quantitative evaluation of ozone and selected climate parameters in a set of EMAC simulations

    NASA Astrophysics Data System (ADS)

    Righi, M.; Eyring, V.; Gottschaldt, K.-D.; Klinger, C.; Frank, F.; Jöckel, P.; Cionni, I.

    2015-03-01

    Four simulations with the ECHAM/MESSy Atmospheric Chemistry (EMAC) model have been evaluated with the Earth System Model Validation Tool (ESMValTool) to identify differences in simulated ozone and selected climate parameters that resulted from (i) different setups of the EMAC model (nudged vs. free-running) and (ii) different boundary conditions (emissions, sea surface temperatures (SSTs) and sea ice concentrations (SICs)). To assess the relative performance of the simulations, quantitative performance metrics are calculated consistently for the climate parameters and ozone. This is important for the interpretation of the evaluation results since biases in climate can impact on biases in chemistry and vice versa. The observational data sets used for the evaluation include ozonesonde and aircraft data, meteorological reanalyses and satellite measurements. The results from a previous EMAC evaluation of a model simulation with nudging towards realistic meteorology in the troposphere have been compared to new simulations with different model setups and updated emission data sets in free-running time slice and nudged quasi chemistry-transport model (QCTM) mode. The latter two configurations are particularly important for chemistry-climate projections and for the quantification of individual sources (e.g., the transport sector) that lead to small chemical perturbations of the climate system, respectively. With the exception of some specific features which are detailed in this study, no large differences that could be related to the different setups (nudged vs. free-running) of the EMAC simulations were found, which offers the possibility to evaluate and improve the overall model with the help of shorter nudged simulations. The main differences between the two setups is a better representation of the tropospheric and stratospheric temperature in the nudged simulations, which also better reproduce stratospheric water vapor concentrations, due to the improved simulation of

  12. 2H nuclear magnetic resonance order parameter profiles suggest a change of molecular shape for phosphatidylcholines containing a polyunsaturated acyl chain.

    PubMed Central

    Holte, L. L.; Peter, S. A.; Sinnwell, T. M.; Gawrisch, K.

    1995-01-01

    Solid-state 2H nuclear magnetic resonance spectroscopy was used to determine the orientational order parameter profiles for a series of phosphatidylcholines with perdeuterated stearic acid, 18:0d35, in position sn-1 and 18:1 omega 9, 18:2 omega 6, 18:3 omega 3, 20:4 omega 6, 20:5 omega 3, or 22:6 omega 3 in position sn-2. The main phase transition temperatures were derived from a first moment analysis, and order parameter profiles of sn-1 chains were calculated from dePaked nuclear magnetic resonance powder patterns. Comparison of the profiles at 37 degrees C showed that unsaturation causes an inhomogenous disordering along the sn-1 chain. Increasing sn-2 chain unsaturation from one to six double bonds resulted in a 1.6-kHz decrease in quadrupolar splittings of the sn-1 chain in the upper half of the chain (or plateau region) and maximum splitting difference of 4.4 kHz at methylene carbon 14. The change in chain order corresponds to a decrease in the 18:0 chain length of 0.4 +/- 0.2 A with 18:2 omega 6 versus 18:1 omega 9 in position sn-2. Fatty acids containing three or more double bonds in sn-2 showed a decrease in sn-1 chain length of 0.7 +/- 0.2 A compared with 18:1 omega 9. The chain length of all lipids decreased with increasing temperature. Highly unsaturated phosphatidylcholines (three or more double bonds in sn-2) had shorter sn-1 chains, but the chain length was somewhat less sensitive to temperature. The profiles reveal that the sn-1 chain exhibits a selective increase in motional freedom in a region located toward the bottom half of the chain as sn-2 unsaturation is increased. This corresponds to an area increase around carbon atom number 14 that is three to four times greater than the increase for the top part of the chain. A similar asymmetric decrease in order, largest toward the methyl end of the chain, was observed when 1 -palmitoyl-2-oleoylphosphatidylethanolamine goes from a lamellar to an inverse hexagonal (H,,) phase. This is consistent with a

  13. LUMPED-PARAMETER MODEL ANALYSES OF DATA FROM THE 1992 NEW HOUSE EVALUATION PROJECT - FLORIDA RADON RESEARCH PROGRAM

    EPA Science Inventory

    The report documents analyses of Phase 2 data from the Florida Radon Research Program's New House Evaluation Project (NHEP) that were performed using a lumped-parameter model. The houses evaluated in Phase 2 were monitored by the Florida Solar Energy Center (FSEC) and the Univers...

  14. Potential inert matrix materials: Materials synthesis and evaluation of in-service engineering parameters

    NASA Astrophysics Data System (ADS)

    Xu, Peng

    Containing no fertile materials, inert matrix fuel (IMF) has been introduced as a potential transmutation solution for the increasing inventory of both weapon grade and reactor grade plutonium (Pu). In the present work, the MgO-pyrochlore (Nd2Zr2O7) composites and spinel magnesium stannate (Mg2SnO4) were selected as potential inert matrix (IM) materials. A comprehensive investigation was conducted on evaluation of the engineering parameters of the potential IM materials. The MgO-Nd2Zr2O7 composites and Mg 2SnO4 were fabricated through conventional solid state processing. The crystal structure and microstructure of the synthesized composites and Mg2SnO4 were studied. The irradiation tolerance of the potential IM materials was first assessed. The resistance of Mg2SnO 4 against irradiation induced amorphization was assessed experimentally using in situ TEM technique. The critical amorphization doses for Mg2SnO4 irradiated by 1 MeV Kr2+ ions were determined to be 5.5 dpa at 50 K and 11.0 dpa at 150 K, respectively. The obtained results were compared with other spinels especially MgAl 2O4, and the radiation tolerance of spinels were discussed. The next evaluation was water corrosion resistance of the potential IM materials. Homogeneous MgO-Nd2Zr2O7 composites exhibited an improved hydrothermal corrosion resistance than inhomogeneous composites and pure MgO. Even though spinel Mg2SnO4 was not stable in water at 300°C and saturation pressure, the corrosion was limited only to the surface, and the volume and mass changes were less than 1 % after 720 h corrosion. Feasibility of aqueous reprocessing was evaluated by studying the dissolution behavior of the potential IM materials in acidic solutions, with an emphasis on nitric acid. Dissolution of the MgO-Nd2Zr2O 7 composites in HNO3 resulted in a selective dissolution of MgO. Mechanical agitation such as magnetic bar stirring was necessary to achieve a completed dissolution of MgO and disintegration of porous Nd 2Zr2O7

  15. Use of Noninvasive Parameters to Evaluate Swiss Webster Mice During Trypanosoma cruzi Experimental Acute Infection.

    PubMed

    Campos, Jerônimo D S; Hoppe, Luanda Y; Duque, Thabata L A; de Castro, Solange Lisboa; Oliveira, Gabriel M

    2016-04-01

    Until now, there has been neither an agreed-upon experimental model nor descriptors of the clinical symptoms that occur over the course of acute murine infection. The aim of this work is to use noninvasive methods to evaluate clinical signs in Swiss Webster mice that were experimentally infected with the Y strain of Trypanosoma cruzi during acute phase (Inf group). Infected mice showed evident clinical changes beginning in the second week of infection (wpi) when compared to the noninfected group (NI): (1) animals in hunched postures, closed eyes, lowered ears, peeling skin, increased piloerection, prostration, and social isolation; (2) significant decrease in body weight (Inf: 26.2 ± 2.6 g vs. NI: 34.2 ± 2.5 g) and in chow (1.5 ± 0.3 vs. 6.3 ± 0.5 mg) and water (2.4 ± 0.5 vs. 5.8 ± 0.7 ml) intake; (3) significant decrease of spontaneous activity as locomotor parameters: distance (0.64 ± 0.06 vs. 1.8 ± 0.13 m), velocity (1.9 ± 0.3 vs. 6.7 ± 1.5 cm/sec), and exploratory behavior by frequency (1.0 ± 0.5 vs. 5.7 ± 1.0 events) and duration (1.4 ± 0.3 vs. 5.1 ± 0.5 sec in central arena region); (4) significant increase in the PR (41.7 ± 8.7 vs. 27.6 ± 1.9 msec) and QT intervals (39.7 ± 2.0 vs. 27.5 ± 4.0 msec), and a decreased cardiac frequency (505 ± 52.8 vs. 774 ± 17.8 msec), showing a marked sinus bradycardia and an atrioventricular block. At 3 and 4 wpi, the surviving animals showed a tendency of recovery in body weight, food intake, locomotor activity, and exploratory interest. Through the use of noninvasive parameters, we were able to monitor the severity of the infection in individuals prior to death. Our perspective is the application of noninvasive methods to describe clinical signs over the course of acute infection complementing the preclinical evaluation of new agents, alone or in combination with benznidazole.

  16. Use of Noninvasive Parameters to Evaluate Swiss Webster Mice During Trypanosoma cruzi Experimental Acute Infection.

    PubMed

    Campos, Jerônimo D S; Hoppe, Luanda Y; Duque, Thabata L A; de Castro, Solange Lisboa; Oliveira, Gabriel M

    2016-04-01

    Until now, there has been neither an agreed-upon experimental model nor descriptors of the clinical symptoms that occur over the course of acute murine infection. The aim of this work is to use noninvasive methods to evaluate clinical signs in Swiss Webster mice that were experimentally infected with the Y strain of Trypanosoma cruzi during acute phase (Inf group). Infected mice showed evident clinical changes beginning in the second week of infection (wpi) when compared to the noninfected group (NI): (1) animals in hunched postures, closed eyes, lowered ears, peeling skin, increased piloerection, prostration, and social isolation; (2) significant decrease in body weight (Inf: 26.2 ± 2.6 g vs. NI: 34.2 ± 2.5 g) and in chow (1.5 ± 0.3 vs. 6.3 ± 0.5 mg) and water (2.4 ± 0.5 vs. 5.8 ± 0.7 ml) intake; (3) significant decrease of spontaneous activity as locomotor parameters: distance (0.64 ± 0.06 vs. 1.8 ± 0.13 m), velocity (1.9 ± 0.3 vs. 6.7 ± 1.5 cm/sec), and exploratory behavior by frequency (1.0 ± 0.5 vs. 5.7 ± 1.0 events) and duration (1.4 ± 0.3 vs. 5.1 ± 0.5 sec in central arena region); (4) significant increase in the PR (41.7 ± 8.7 vs. 27.6 ± 1.9 msec) and QT intervals (39.7 ± 2.0 vs. 27.5 ± 4.0 msec), and a decreased cardiac frequency (505 ± 52.8 vs. 774 ± 17.8 msec), showing a marked sinus bradycardia and an atrioventricular block. At 3 and 4 wpi, the surviving animals showed a tendency of recovery in body weight, food intake, locomotor activity, and exploratory interest. Through the use of noninvasive parameters, we were able to monitor the severity of the infection in individuals prior to death. Our perspective is the application of noninvasive methods to describe clinical signs over the course of acute infection complementing the preclinical evaluation of new agents, alone or in combination with benznidazole. PMID:26741817

  17. Evaluation of Parameter Uncertainty Reduction in Groundwater Flow Modeling Using Multiple Environmental Tracers

    NASA Astrophysics Data System (ADS)

    Arnold, B. W.; Gardner, P.

    2013-12-01

    Calibration of groundwater flow models for the purpose of evaluating flow and aquifer heterogeneity typically uses observations of hydraulic head in wells and appropriate boundary conditions. Environmental tracers have a wide variety of decay rates and input signals in recharge, resulting in a potentially broad source of additional information to constrain flow rates and heterogeneity. A numerical study was conducted to evaluate the reduction in uncertainty during model calibration using observations of various environmental tracers and combinations of tracers. A synthetic data set was constructed by simulating steady groundwater flow and transient tracer transport in a high-resolution, 2-D aquifer with heterogeneous permeability and porosity using the PFLOTRAN software code. Data on pressure and tracer concentration were extracted at well locations and then used as observations for automated calibration of a flow and transport model using the pilot point method and the PEST code. Optimization runs were performed to estimate parameter values of permeability at 30 pilot points in the model domain for cases using 42 observations of: 1) pressure, 2) pressure and CFC11 concentrations, 3) pressure and Ar-39 concentrations, and 4) pressure, CFC11, Ar-39, tritium, and He-3 concentrations. Results show significantly lower uncertainty, as indicated by the 95% linear confidence intervals, in permeability values at the pilot points for cases including observations of environmental tracer concentrations. The average linear uncertainty range for permeability at the pilot points using pressure observations alone is 4.6 orders of magnitude, using pressure and CFC11 concentrations is 1.6 orders of magnitude, using pressure and Ar-39 concentrations is 0.9 order of magnitude, and using pressure, CFC11, Ar-39, tritium, and He-3 concentrations is 1.0 order of magnitude. Data on Ar-39 concentrations result in the greatest parameter uncertainty reduction because its half-life of 269

  18. Practice Parameters for the Clinical Evaluation and Treatment of Circadian Rhythm Sleep Disorders

    PubMed Central

    Morgenthaler, Timothy I.; Lee-Chiong, Teofilo; Alessi, Cathy; Friedman, Leah; Aurora, R. Nisha; Boehlecke, Brian; Brown, Terry; Chesson, Andrew L.; Kapur, Vishesh; Maganti, Rama; Owens, Judith; Pancer, Jeffrey; Swick, Todd J.; Zak, Rochelle

    2007-01-01

    The expanding science of circadian rhythm biology and a growing literature in human clinical research on circadian rhythm sleep disorders (CRSDs) prompted the American Academy of Sleep Medicine (AASM) to convene a task force of experts to write a review of this important topic. Due to the extensive nature of the disorders covered, the review was written in two sections. The first review paper, in addition to providing a general introduction to circadian biology, addresses “exogenous” circadian rhythm sleep disorders, including shift work disorder (SWD) and jet lag disorder (JLD). The second review paper addresses the “endogenous” circadian rhythm sleep disorders, including advanced sleep phase disorder (ASPD), delayed sleep phase disorder (DSPD), irregular sleep-wake rhythm (ISWR), and the non–24-hour sleep-wake syndrome (nonentrained type) or free-running disorder (FRD). These practice parameters were developed by the Standards of Practice Committee and reviewed and approved by the Board of Directors of the AASM to present recommendations for the assessment and treatment of CRSDs based on the two accompanying comprehensive reviews. The main diagnostic tools considered include sleep logs, actigraphy, the Morningness-Eveningness Questionnaire (MEQ), circadian phase markers, and polysomnography. Use of a sleep log or diary is indicated in the assessment of patients with a suspected circadian rhythm sleep disorder (Guideline). Actigraphy is indicated to assist in evaluation of patients suspected of circadian rhythm disorders (strength of recommendation varies from “Option” to “Guideline,” depending on the suspected CRSD). Polysomnography is not routinely indicated for the diagnosis of CRSDs, but may be indicated to rule out another primary sleep disorder (Standard). There is insufficient evidence to justify the use of MEQ for the routine clinical evaluation of CRSDs (Option). Circadian phase markers are useful to determine circadian phase and confirm

  19. Evaluating Swallowing Muscles Essential for Hyolaryngeal Elevation by Using Muscle Functional Magnetic Resonance Imaging

    SciTech Connect

    Pearson, William G.; Hindson, David F.; Langmore, Susan E.; Zumwalt, Ann C.

    2013-03-01

    Purpose: Reduced hyolaryngeal elevation, a critical event in swallowing, is associated with radiation therapy. Two muscle groups that suspend the hyoid, larynx, and pharynx have been proposed to elevate the hyolaryngeal complex: the suprahyoid and longitudinal pharyngeal muscles. Thought to assist both groups is the thyrohyoid, a muscle intrinsic to the hyolaryngeal complex. Intensity modulated radiation therapy guidelines designed to preserve structures important to swallowing currently exclude the suprahyoid and thyrohyoid muscles. This study used muscle functional magnetic resonance imaging (mfMRI) in normal healthy adults to determine whether both muscle groups are active in swallowing and to test therapeutic exercises thought to be specific to hyolaryngeal elevation. Methods and Materials: mfMRI data were acquired from 11 healthy subjects before and after normal swallowing and after swallowing exercise regimens (the Mendelsohn maneuver and effortful pitch glide). Whole-muscle transverse relaxation time (T2 signal, measured in milliseconds) profiles of 7 test muscles were used to evaluate the physiologic response of each muscle to each condition. Changes in effect size (using the Cohen d measure) of whole-muscle T2 profiles were used to determine which muscles underlie swallowing and swallowing exercises. Results: Post-swallowing effect size changes (where a d value of >0.20 indicates significant activity during swallowing) for the T2 signal profile of the thyrohyoid was a d value of 0.09; a d value of 0.40 for the mylohyoid, 0.80 for the geniohyoid, 0.04 for the anterior digastric, and 0.25 for the posterior digastric-stylohyoid in the suprahyoid muscle group; and d values of 0.47 for the palatopharyngeus and 0.28 for the stylopharyngeus muscles in the longitudinal pharyngeal muscle group. The Mendelsohn maneuver and effortful pitch glide swallowing exercises showed significant effect size changes for all muscles tested, except for the thyrohyoid. Conclusions

  20. Magnetic resonance imaging and BMB score in the evaluation of bone involvement in Gaucher’s disease patients*

    PubMed Central

    de Mello, Ricardo Andrade Fernandes; Mello, Melissa Bozzi Nonato; Pessanha, Laís Bastos

    2015-01-01

    Objective To evaluate by magnetic resonance imaging changes in bone marrow of patients undergoing treatment for type I Gaucher’s disease. Materials and Methods Descriptive, cross-sectional study of Gaucher’s disease patients submitted to 3 T magnetic resonance imaging of femurs and lumbar spine. The images were blindly reviewed and the findings were classified according to the semiquantitative bone marrow burden (BMB) scoring system. Results All of the seven evaluated patients (three men and four women) presented signs of bone marrow infiltration. Osteonecrosis of the femoral head was found in three patients, Erlenmeyer flask deformity in five, and no patient had vertebral body collapse. The mean BMB score was 11, ranging from 9 to 14. Conclusion Magnetic resonance imaging is currently the method of choice for assessing bone involvement in Gaucher’s disease in adults due to its high sensitivity to detect both focal and diffuse bone marrow changes, and the BMB score is a simplified method for semiquantitative analysis, without depending on advanced sequences or sophisticated hardware, allowing for the classification of the disease extent and assisting in the treatment monitoring. PMID:26379319

  1. Evaluation of control parameters for Spray-In-Air (SIA) aqueous cleaning for shuttle RSRM hardware

    NASA Technical Reports Server (NTRS)

    Davis, S. J.; Deweese, C. D.

    1995-01-01

    HD-2 grease is deliberately applied to Shuttle Redesigned Solid Rocket Motor (RSRM) D6AC steel hardware parts as a temporary protective coating for storage and shipping. This HD-2 grease is the most common form of surface contamination on RSRM hardware and must be removed prior to subsequent surface treatment. Failure to achieve an acceptable level of cleanliness (HD-2 calcium grease removal) is a common cause of defect incidence. Common failures from ineffective cleaning include poor adhesion of surface coatings, reduced bond performance of structural adhesives, and failure to pass cleanliness inspection standards. The RSRM hardware is currently cleaned and refurbished using methyl chloroform (1,1,1-trichloroethane). This chlorinated solvent is mandated for elimination due to its ozone depleting characteristics. This report describes an experimental study of an aqueous cleaning system (which uses Brulin 815 GD) as a replacement for methyl chloroform. Evaluation of process control parameters for this cleaner are discussed as well as cleaning mechanisms for a spray-in-air process.

  2. Evaluating the Spatio-Temporal Factors that Structure Network Parameters of Plant-Herbivore Interactions

    PubMed Central

    López-Carretero, Antonio; Díaz-Castelazo, Cecilia; Boege, Karina; Rico-Gray, Víctor

    2014-01-01

    Despite the dynamic nature of ecological interactions, most studies on species networks offer static representations of their structure, constraining our understanding of the ecological mechanisms involved in their spatio-temporal stability. This is the first study to evaluate plant-herbivore interaction networks on a small spatio-temporal scale. Specifically, we simultaneously assessed the effect of host plant availability, habitat complexity and seasonality on the structure of plant-herbivore networks in a coastal tropical ecosystem. Our results revealed that changes in the host plant community resulting from seasonality and habitat structure are reflected not only in the herbivore community, but also in the emergent properties (network parameters) of the plant-herbivore interaction network such as connectance, selectiveness and modularity. Habitat conditions and periods that are most stressful favored the presence of less selective and susceptible herbivore species, resulting in increased connectance within networks. In contrast, the high degree of selectivennes (i.e. interaction specialization) and modularity of the networks under less stressful conditions was promoted by the diversification in resource use by herbivores. By analyzing networks at a small spatio-temporal scale we identified the ecological factors structuring this network such as habitat complexity and seasonality. Our research offers new evidence on the role of abiotic and biotic factors in the variation of the properties of species interaction networks. PMID:25340790

  3. Estimation of parameters for evaluating subsurface microcracks in glass with in-line digital holographic microscopy.

    PubMed

    Wu, Xiupin; Gao, Wanrong; He, Yong

    2016-01-20

    In this work, a new method for imaging subsurface damage (SSD) is proposed, which is, to the best of our knowledge, the first application of the in-line digital holographic microscopy (IDHM) to the reconstruction of the subsurface damage in glass. By combination of the in-line arrangement and an objective lens to image the hologram on the CCD surface, the method is characterized by its high resolution in both the lateral and depth directions. Then the three-dimensional reconstruction of the microcracks within the glass was realized by numerically focusing en-face images at different depths, and the sizes of SSD along the transversal and depth directions were estimated. Based on the experimental results, the cracks can be divided into two categories: one is that the cracks begin from the surface of optical elements, the other is totally within the components. To indicate the propagation or development trajectory of the cracks and predict the magnitude of the laser-induced damage threshold, the relative intensity distributions of the light scattered by the cracks compared with the ones without cracks were also reconstructed. In this case all the required parameters for evaluating SSD are obtained with our IDHM system, so that the SSD produced in the manufacturing process can be reduced or removed more easily to optimize the performance of the optical component and extend its lifetime. These results provide the guidance for the optical system design of precision measurements. PMID:26835955

  4. Low-level laser therapy on skeletal muscle inflammation: evaluation of irradiation parameters

    NASA Astrophysics Data System (ADS)

    Mantineo, Matías; Pinheiro, João P.; Morgado, António M.

    2014-09-01

    We evaluated the effect of different irradiation parameters in low-level laser therapy (LLLT) for treating inflammation induced in the gastrocnemius muscle of rats through cytokines concentration in systemic blood and analysis of muscle tissue. We used continuous (830 and 980 nm) and pulsed illuminations (830 nm). Animals were divided into five groups per wavelength (10, 20, 30, 40, and 50 mW), and a control group. LLLT was applied during 5 days with a constant irradiation time and area. TNF-α, IL-1β, IL-2, and IL-6 cytokines were quantified by ELISA. Inflammatory cells were counted using microscopy. Identical methodology was used with pulsed illumination. Average power (40 mW) and duty cycle were kept constant (80%) at five frequencies (5, 25, 50, 100, and 200 Hz). For continuous irradiation, treatment effects occurred for all doses, with a reduction of TNF-α, IL-1β, and IL-6 cytokines and inflammatory cells. Continuous irradiation at 830 nm was more effective, a result explained by the action spectrum of cytochrome c oxidase (CCO). Best results were obtained for 40 mW, with data suggesting a biphasic dose response. Pulsed wave irradiation was only effective for higher frequencies, a result that might be related to the rate constants of the CCO internal electron transfer process.

  5. Stability evaluation of parameter estimation of multi-Rayleigh model for ultrasound B-mode image of liver fibrosis

    NASA Astrophysics Data System (ADS)

    Mori, Shohei; Ohashi, Minori; Hirata, Shinnosuke; Hachiya, Hiroyuki

    2016-07-01

    A diagnosis of liver fibrosis using an ultrasound B-mode image has the advantages of real-time observation and noninvasive properties. In our previous study, a multi-Rayleigh model was proposed to express a probability density function (PDF) of echo amplitudes from a fibrotic liver. From the multi-Rayleigh model, fibrosis parameters, such as the amount of fibrotic tissue and its progressive ratio, can be extracted. To quantitatively evaluate liver fibrosis using the multi-Rayleigh model, it is important to evaluate the stability of the estimation method of multi-Rayleigh model parameters. In this study, a numerical simulation using random variables following the multi-Rayleigh model was performed and the estimation stability of the parameters of the multi-Rayleigh model with two components was examined. From the simulation results, it was found that estimation becomes unstable under a certain condition owing to statistical variations of moments, which are inputs in the estimation algorithm. The instability of estimated parameters could be evaluated by focusing on changes in moments upon changes in multi-Rayleigh model parameters. It was indicated that we can evaluate the reliability of the estimated parameters of the multi-Rayleigh model only from the estimated values.

  6. Measurement of the CP-Violation Parameter sin2Φ₁ with a New Tagging Method at the Υ(5S) Resonance

    SciTech Connect

    Sato, Y.; Yamamoto, H.; Aihara, H.; Asner, D. M.; Aulchenko, V.; Aushev, T.; Aziz, T.; Bakich, A. M.; Bhardwaj, V.; Bhuyan, B.; Bischofberger, M.; Bondar, A.; Bozek, A.; Bračko, M.; Browder, T. E.; Chang, P.; Chen, P.; Cheon, B. G.; Chilikin, K.; Chistov, R.; Cho, I.-S.; Cho, K.; Choi, S.-K.; Choi, Y.; Dalseno, J.; Doležal, Z.; Drásal, Z.; Eidelman, S.; Epifanov, D.; Fast, J. E.; Gaur, V.; Gabyshev, N.; Goh, Y. M.; Golob, B.; Haba, J.; Hara, T.; Hayasaka, K.; Hayashii, H.; Horii, Y.; Hoshi, Y.; Hou, W.-S.; Hyun, H. J.; Ishikawa, A.; Itoh, R.; Iwabuchi, M.; Iwasaki, Y.; Iwashita, T.; Julius, T.; Kapusta, P.; Kawasaki, T.; Kichimi, H.; Kiesling, C.; Kim, H. J.; Kim, H. O.; Kim, J. B.; Kim, J. H.; Kim, K. T.; Kim, M. J.; Kim, S. K.; Kim, Y. J.; Kinoshita, K.; Ko, B. R.; Kobayashi, N.; Kodyš, P.; Korpar, S.; Križan, P.; Krokovny, P.; Kuhr, T.; Kumar, R.; Kumita, T.; Kuzmin, A.; Kwon, Y.-J.; Lange, J. S.; Lee, S.-H.; Li, J.; Li, Y.; Liu, C.; Liu, Z. Q.; Louvot, R.; McOnie, S.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Mohanty, G. B.; Moll, A.; Muramatsu, N.; Nakano, E.; Nakao, M.; Nakazawa, H.; Natkaniec, Z.; Nishida, S.; Nishimura, K.; Nitoh, O.; Ogawa, S.; Ohshima, T.; Okuno, S.; Olsen, S. L.; Onuki, Y.; Ostrowicz, W.; Pakhlov, P.; Pakhlova, G.; Park, C. W.; Park, H.; Park, H. K.; Pedlar, T. K.; Petrič, M.; Piilonen, L. E.; Poluektov, A.; Röhrken, M.; Ryu, S.; Sahoo, H.; Sakai, Y.; Sanuki, T.; Schneider, O.; Schwanda, C.; Schwartz, A. J.; Seidl, R.; Senyo, K.; Seon, O.; Sevior, M. E.; Shapkin, M.; Shen, C. P.; Shibata, T.-A.; Shiu, J.-G.; Shwartz, B.; Sibidanov, A.; Simon, F.; Smerkol, P.; Sohn, Y.-S.; Sokolov, A.; Solovieva, E.; Stanič, S.; Starič, M.; Stypula, J.; Sumihama, M.; Sumiyoshi, T.; Tanaka, S.; Tatishvili, G.; Teramoto, Y.; Trabelsi, K.; Uchida, M.; Uglov, T.; Unno, Y.; Uno, S.; Urquijo, P.; Varner, G.; Varvell, K. E.; Wang, C. H.; Wang, M.-Z.; Wang, P.; Wang, X. L.; Watanabe, M.; Watanabe, Y.; Wicht, J.; Won, E.; Yabsley, B. D.; Yamashita, Y.; Yusa, Y.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.

    2012-04-23

    We report a measurement of the CP-violation parameter sin2Φ₁ at the Υ(5S) resonance using a new tagging method, called “B-π tagging.” In Υ(5S) decays containing a neutral B meson, a charged B, and a charged pion, the neutral B is reconstructed in the J/ψK0SCP-eigenstate decay channel. The initial flavor of the neutral B meson at the moment of the Υ(5S) decay is opposite to that of the charged B and may thus be inferred from the charge of the pion without reconstructing the charged B. From the asymmetry between B-π⁺ and Bπ⁻ tagged J/ψK0S yields, we determine sin2Φ₁=0.57±0.58(stat)±0.06(syst). The results are based on 121 fb⁻¹ of data recorded by the Belle detector at the KEKB e⁺e⁻ collider.

  7. Measurement of the CP-Violation Parameter sin2Φ₁ with a New Tagging Method at the Υ(5S) Resonance

    DOE PAGESBeta

    Sato, Y.; Yamamoto, H.; Aihara, H.; Asner, D. M.; Aulchenko, V.; Aushev, T.; Aziz, T.; Bakich, A. M.; Bhardwaj, V.; Bhuyan, B.; et al

    2012-04-23

    We report a measurement of the CP-violation parameter sin2Φ₁ at the Υ(5S) resonance using a new tagging method, called “B-π tagging.” In Υ(5S) decays containing a neutral B meson, a charged B, and a charged pion, the neutral B is reconstructed in the J/ψK0SCP-eigenstate decay channel. The initial flavor of the neutral B meson at the moment of the Υ(5S) decay is opposite to that of the charged B and may thus be inferred from the charge of the pion without reconstructing the charged B. From the asymmetry between B-π⁺ and Bπ⁻ tagged J/ψK0S yields, we determine sin2Φ₁=0.57±0.58(stat)±0.06(syst). The resultsmore » are based on 121 fb⁻¹ of data recorded by the Belle detector at the KEKB e⁺e⁻ collider.« less

  8. Evaluation of ventricular geometry and performance in congenital heart disease utilizing magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Fogel, Mark A.

    1994-05-01

    We have recently embarked on a systematic evaluation of the regional and global mechanical processes of the systemic, morphologic right ventricle (RV) which is in either a single or dual chambered circulation as well as single left ventricles (LV). An MRI tagging technique which lays down 2 sets of parallel stripes perpendicular to each other on the myocardium as well as standard cine MRI were utilized. Finite strain analysis was applied to the grid lines to derive principle strains and the motion of the intersection points were tracked through systole to determine regional radial shortening and twist. Cine sequences were used to derive the various parameters of ventricular geometry and performance as well as visualizing flow profiles in the aorta. We noted a marked decrease in vol, EF, and CO in the Fontan group of patients when compared to other surgical subgroups. It is hypothesized that atrial stiffening by surgical placement of baffles may contribute to the observed changes in ventricular mechanics. Aortic flow profiles in the reconstructed aorta were noted to be heterogenous across the aortic diameter.

  9. Resonant Ultrasound Spectroscopy, as Applied to Nondestructive Evaluation and Characterization of Carbon Fiber Reinforced Epoxy Composite Materials.

    NASA Astrophysics Data System (ADS)

    Whitney, Timothy Marvin

    1996-08-01

    Resonant ultrasound spectroscopy (RUS) can be an elegantly simple nondestructive evaluation tool. The resonance spectrum of any specimen is dependent on, and sensitive at ppm levels to, its density, geometry, elastic and thermal properties, and boundary conditions. The measurement of spectrum is fast, taking between 15 and 90 seconds with state-of-the-art instrumentation, making it appropriate for following properties as a function of temperature. Parts per million changes in specimen density, geometry, elastic moduli, temperature, and boundary conditions are detected with RUS. A novel apparatus is presented for driving and detecting the mechanical resonance of objects with major dimensions ranging from 0.1 cm to 33 cm. The noise floor of the apparatus is characterized using a high Q titanium alloy and a low Q graphite/epoxy composite. The apparatus is used to measure the amplitude/frequency resonance spectra of right rectangular parallelepiped (RRP) specimens of four different lay-ups of AS4/3501-6 carbon fiber reinforced epoxy (CFRE) composite material at room temperature and at one degree C intervals between -177^circC and 25 ^circC. It is important to know the mechanical properties of this material at low temperatures for underwater, polar, and space applications. The temperature dependence of the second order elastic moduli are calculated from the resonance spectra of the AS4/3501-6 RRPs. High power ultrasound is used to enhance the cure of AS4/3501-6 CFRE composite. Composite panels are insonified through the caul plate, by a high power ultrasonic horn, while curing. Stiffness enhancements of five percent are observed. The resonance spectrum of a steel caul plate is used to monitor the degree of cure of AS4/3501-6 CFRE composite panels in real time. Because the curing composite acts to change the boundary conditions, the resonance spectrum changes as the composite cures. RUS is used to screen a variety of high precision engineered parts for mechanical defects

  10. Estimation of Ecosystem Parameters of the Community Land Model with DREAM: Evaluation of the Potential for Upscaling Net Ecosystem Exchange

    NASA Astrophysics Data System (ADS)

    Hendricks Franssen, H. J.; Post, H.; Vrugt, J. A.; Fox, A. M.; Baatz, R.; Kumbhar, P.; Vereecken, H.

    2015-12-01

    Estimation of net ecosystem exchange (NEE) by land surface models is strongly affected by uncertain ecosystem parameters and initial conditions. A possible approach is the estimation of plant functional type (PFT) specific parameters for sites with measurement data like NEE and application of the parameters at other sites with the same PFT and no measurements. This upscaling strategy was evaluated in this work for sites in Germany and France. Ecosystem parameters and initial conditions were estimated with NEE-time series of one year length, or a time series of only one season. The DREAM(zs) algorithm was used for the estimation of parameters and initial conditions. DREAM(zs) is not limited to Gaussian distributions and can condition to large time series of measurement data simultaneously. DREAM(zs) was used in combination with the Community Land Model (CLM) v4.5. Parameter estimates were evaluated by model predictions at the same site for an independent verification period. In addition, the parameter estimates were evaluated at other, independent sites situated >500km away with the same PFT. The main conclusions are: i) simulations with estimated parameters reproduced better the NEE measurement data in the verification periods, including the annual NEE-sum (23% improvement), annual NEE-cycle and average diurnal NEE course (error reduction by factor 1,6); ii) estimated parameters based on seasonal NEE-data outperformed estimated parameters based on yearly data; iii) in addition, those seasonal parameters were often also significantly different from their yearly equivalents; iv) estimated parameters were significantly different if initial conditions were estimated together with the parameters. We conclude that estimated PFT-specific parameters improve land surface model predictions significantly at independent verification sites and for independent verification periods so that their potential for upscaling is demonstrated. However, simulation results also indicate

  11. A laser gyro with a four-mirror square resonator: formulas for simulating the dynamics of the synchronisation zone parameters of the frequencies of counterpropagating waves during the device operation in the self-heating regime

    SciTech Connect

    Bondarenko, E A

    2014-04-28

    For a laser gyro with a four-mirror square resonator we have developed a mathematical model, which allows one to simulate the temporal behaviour of the synchronisation zone parameters of the frequencies of counterpropagating waves in a situation when the device operates in the self-heating regime and is switched-on at different initial temperatures. (laser gyroscopes)

  12. Radiation-Induced Damage to Microstructure of Parotid Gland: Evaluation Using High-Resolution Magnetic Resonance Imaging

    SciTech Connect

    Kan, Tomoko; Kodani, Kazuhiko; Michimoto, Koichi; Fujii, Shinya; Ogawa, Toshihide

    2010-07-15

    Purpose: To elucidate the radiation-induced damage to the microstructure of the parotid gland using high-resolution magnetic resonance imaging. Methods and Materials: High-resolution magnetic resonance imaging of the parotid gland was performed before radiotherapy (RT) and during the RT period or {<=}3 weeks after RT completion for 12 head-and-neck cancer patients using a 1.5-T scanner with a microscopy coil. The maximal cross-sectional area of the gland was evaluated, and changes in the internal architecture of the gland were assessed both visually and quantitatively. Results: Magnetic resonance images were obtained at a median parotid gland dose of 36 Gy (range, 11-64). According to the quantitative analysis, the maximal cross-sectional area of the gland was reduced, the width of the main duct was narrowed, and the intensity ratio of the main duct lumen to background was significantly decreased after RT (p <.0001). According to the visual assessment, the width of the main duct tended to narrow and the contrast of the duct lumen tended to be decreased, but no significant differences were noted. The visibility of the duct branches was unclear in 10 patients (p = .039), and the septum became dense in 11 patients (p = .006) after RT. Conclusion: High-resolution magnetic resonance imaging is a noninvasive method of evaluating radiation-induced changes to the internal architecture of the parotid gland. Morphologic changes in the irradiated parotid gland were demonstrated during the RT course even when a relatively small dose was delivered to the gland.

  13. [Isovolumic relaxation flow patterns evaluated by pulsed Doppler echocardiography: comparison with invasive parameters].

    PubMed

    Kuroiwa, N; Nakamura, K; Kawahira, M; Sanada, J; Hashimoto, S

    1986-03-01

    Left ventricular relaxation property was evaluated by pulsed Doppler echocardiography. The indices obtained from Doppler signals within the left ventricle (LV) during the isovolumic relaxation period (IRF) were compared with the hemodynamic parameters obtained from cardiac catheterization studies. Subjects of this study were four patients with hypertrophic cardiomyopathy, four with hypertensive heart disease, three with angina pectoris, and seven normal subjects. All of them had no wall motion abnormalities and their ejection fractions were more than 0.60. The three indices of IRF were the time interval from the start of IRF to the time immediately before the rapid filling flow (isovolumic relaxation time; IRT), the time interval from the start to the peak (acceleration time; AcT), and the slope from the start to the peak (acceleration rate; AcR). The peak pressure (peak P) was measured at the same time. The positive and negative deflections of the first derivative of left ventricular (LV) pressure (+dp/dt and -dp/dt) and the time constant of LV pressure fall (time constant T) were calculated from LV pressure using a micromanometer-tipped angiocatheter. The end-diastolic volume index (EDVI), end-systolic volume index (ESVI), and ejection fraction (EF) were calculated from the LV angiogram. There were no significant correlations between the three IRF indices (IRT, AcT and AcR) and the hemodynamic parameters (peak P, EDVI, +dp/dt and -dp/dt). However, the time constant T, which is a good index of LV relaxation property and which is relatively free from afterload and preload, correlated well with IRT (r = 0.75, p less than 0.001), AcT (r = 0.60, p less than 0.01), and AcR (r = -0.66, p less than 0.01). It was concluded that the indices obtained from the blood flow patterns of the left ventricle during isovolumic relaxation were useful for estimating left ventricular relaxation property non-invasively and quantitatively.

  14. Evaluation of Sensitivity and Robustness of Geothermal Resource Parameters Using Detailed and Approximate Stratigraphy

    NASA Astrophysics Data System (ADS)

    Whealton, C.; Jordan, T. E.; Frone, Z. S.; Smith, J. D.; Horowitz, F. G.; Stedinger, J. R.

    2015-12-01

    Accurate assessment of the spatial variation of geothermal heat is key to distinguishing among locations for geothermal project development. Resource assessment over large areas can be accelerated by using existing subsurface data collected for other purposes, such as petroleum industry bottom-hole temperature (BHT) datasets. BHT data are notoriously noisy but in many sedimentary basins their abundance offsets the potential low quality of an individual BHT measurement. Analysis requires description of conductivity stratigraphy, which for thousands of wells with BHT values is daunting. For regional assessment, a streamlined method is to approximate the thickness and conductivity of each formation using a set of standard columns rescaled to the sediment thickness at a location. Surface heat flow and related geothermal resource metrics are estimated from these and additional parameters. This study uses Monte Carlo techniques to compare the accuracy and precision of thermal predictions at single locations by the streamlined approach to well-specific conductivity stratigraphy. For 77 wells distributed across the Appalachian Basin of NY, PA, and WV, local geological experts made available detailed information on unit thicknesses . For the streamlined method we used the Correlation of Stratigraphic Units of North America (COSUNA) columns. For both data sets, we described thermal conductivity of the strata using generic values or values from the geologically similar Anadarko Basin. The well-specific surface heat flow and temperature-at-depth were evaluated using a one-dimensional conductive heat flow model. This research addresses the sensitivity of the estimated geothermal output to the model inputs (BHT, thermal conductivity) and the robustness of the approximate stratigraphic column assumptions when estimating the geothermal output. This research was conducted as part of the Dept. of Energy Geothermal Play Fairway Analysis program.

  15. A critical evaluation of the relevant parameters for drug redispersion from adhesive mixtures during inhalation.

    PubMed

    de Boer, A H; Dickhoff, B H J; Hagedoorn, P; Gjaltema, D; Goede, J; Lambregts, D; Frijlink, H W

    2005-04-27

    In this paper, the parameters that are relevant to the drug redispersion from adhesive mixtures during inhalation are discussed and evaluated. The results obtained with air classifier technology give strong evidence for a dominating influence of carrier surface properties on the fraction of drug detached during inhalation at a low carrier payload (< or =1%, w/w), versus a dominating effect of carrier bulk properties at higher payloads. Furthermore, the results indicate that there is a fundamental difference between so-called active carrier sites and large surface discontinuities. The difference refers to the saturation concentrations, the rates of saturation and their effects on drug detachment during inhalation. The degree of saturation of the active sites appears to be proportional with the square root of the carrier surface payload (after 10 min mixing time in a Turbula mixer at 90 rpm). The storage volume of the discontinuities seems largely independent of the carrier diameter for particles derived from the same batch of crystalline lactose. Saturation of these discontinuities is completed at a much lower carrier surface payload than saturation of the active sites. Relatively large discontinuities are beneficial to de-agglomeration principles that make use of inertial separation forces during inhalation, as they provide shelter from inertial and frictional press-on forces during mixing which increase the strength of the interparticulate bonds in the powder mixture. For de-agglomeration principles generating frictional, drag or lift forces, carrier surface depressions and projections are disadvantageous however, as they also provide shelter from these removal forces. PMID:15814242

  16. Prospective evaluation of healthy Ragdoll cats for chronic kidney disease by routine laboratory parameters and ultrasonography.

    PubMed

    Paepe, Dominique; Bavegems, Valérie; Combes, Anaïs; Saunders, Jimmy H; Daminet, Sylvie

    2013-10-01

    Ragdoll breeder organisations often forewarn Ragdoll cat owners that renal problems may develop as a result of polycystic kidney disease (PKD), chronic interstitial nephritis, familial renal dysplasia or nephrocalcinosis. Healthy Ragdoll and non-Ragdoll cats were prospectively evaluated by measuring serum creatinine and urea concentrations, routine urinalysis and abdominal ultrasonography. All Ragdoll cats also underwent genetic PKD testing. One hundred and thirty-three Ragdoll and 62 control cats were included. Ragdoll cats had significantly lower serum urea concentrations and higher urinary specific gravity. However, median creatinine concentration, median urinary protein-to-creatinine ratio, and the proportion of cats with serum creatinine or urea concentration exceeding the reference interval did not differ. One or more renal ultrasonographical changes were detected in 66/133 (49.6%) Ragdoll and in 25/62 (40%) control cats. Ragdoll cats showed significantly more frequent segmental cortical lesions (7.5% versus 0%), abnormal renal capsule (19.5% versus 8%) and echogenic urine (51.9% versus 25.8%). Chronic kidney disease (CKD) was ultrasonographically suspected in 7/133 (5.3%) Ragdoll and in none of the control cats, which approached significance. Laboratory parameters confirmed kidney dysfunction only in 1/7 of these Ragdoll cats. All Ragdoll cats were PKD negative. In conclusion, first, breed-specific serum creatinine reference intervals are not likely required for Ragdoll cats. Second, renal ultrasonographical abnormalities are common, both in Ragdoll and non-Ragdoll cats. Third, healthy young Ragdoll cats are uncommonly affected by PKD and CKD, but an increased susceptibility of Ragdoll cats to develop CKD cannot be excluded. Finally, Ragdoll cats are predisposed to segmental cortical lesions, which may indicate renal infarction or cortical scarring.

  17. Radiation Pneumonitis After Hypofractionated Radiotherapy: Evaluation of the LQ(L) Model and Different Dose Parameters

    SciTech Connect

    Borst, Gerben R.; Ishikawa, Masayori; Nijkamp, Jasper

    2010-08-01

    Purpose: To evaluate the linear quadratic (LQ) model for hypofractionated radiotherapy within the context of predicting radiation pneumonitis (RP) and to investigate the effect if a linear (L) model in the high region (LQL model) is used. Methods and Materials: The radiation doses used for 128 patients treated with hypofractionated radiotherapy were converted to the equivalent doses given in fractions of 2 Gy for a range of {alpha}/{beta} ratios (1 Gy to infinity) according to the LQ(L) model. For the LQL model, different cut-off values between the LQ model and the linear component were used. The Lyman model parameters were fitted to the events of RP grade 2 or higher to derive the normal tissue complication probability (NTCP). The lung dose was calculated as the mean lung dose and the percentage of lung volume (V) receiving doses higher than a threshold dose of xGy (V{sub x}). Results: The best NTCP fit was found if the mean lung dose, or V{sub x}, was calculated with an {alpha}/{beta} ratio of 3 Gy. The NTCP fit of other {alpha}/{beta} ratios and the LQL model were worse but within the 95% confidence interval of the NTCP fit of the LQ model with an {alpha}/{beta} ratio of 3 Gy. The V{sub 50} NTCP fit was better than the NTCP fit of lower threshold doses. Conclusions: For high fraction doses, the LQ model with an {alpha}/{beta} ratio of 3 Gy was the best method for converting the physical lung dose to predict RP.

  18. Solitary fibrous tumor of the liver: magnetic resonance imaging evaluation and treatment with transarterial chemoembolization.

    PubMed

    El-Khouli, Riham H; Geschwind, Jean-Francois H; Bluemke, David A; Kamel, Ihab R

    2008-01-01

    Solitary fibrous tumor (SFT) is an uncommon neoplasm first described as a tumor of mesenchymal origin that rarely involves the liver. This report presents a rare case of unresectable SFT of the liver and documents the first use of transarterial chemoembolization in its treatment. Three sessions of chemoembolization were performed aiming to reduce the tumor size or at least stabilize it. Subsequent follow-up magnetic resonance imaging examinations were performed to assess imaging response to treatment. We recommend further studies to be done to assess both the use of transarterial chemoembolization in the treatment of unresectable SFT and the use of contrast-enhanced and diffusion-weighted magnetic resonance imaging for assessment of the tumor response to treatment.

  19. Parasitic analysis and π-type Butterworth-Van Dyke model for complementary-metal-oxide-semiconductor Lamb wave resonator with accurate two-port Y-parameter characterizations

    NASA Astrophysics Data System (ADS)

    Wang, Yong; Goh, Wang Ling; Chai, Kevin T.-C.; Mu, Xiaojing; Hong, Yan; Kropelnicki, Piotr; Je, Minkyu

    2016-04-01

    The parasitic effects from electromechanical resonance, coupling, and substrate losses were collected to derive a new two-port equivalent-circuit model for Lamb wave resonators, especially for those fabricated on silicon technology. The proposed model is a hybrid π-type Butterworth-Van Dyke (PiBVD) model that accounts for the above mentioned parasitic effects which are commonly observed in Lamb-wave resonators. It is a combination of interdigital capacitor of both plate capacitance and fringe capacitance, interdigital resistance, Ohmic losses in substrate, and the acoustic motional behavior of typical Modified Butterworth-Van Dyke (MBVD) model. In the case studies presented in this paper using two-port Y-parameters, the PiBVD model fitted significantly better than the typical MBVD model, strengthening the capability on characterizing both magnitude and phase of either Y11 or Y21. The accurate modelling on two-port Y-parameters makes the PiBVD model beneficial in the characterization of Lamb-wave resonators, providing accurate simulation to Lamb-wave resonators and oscillators.

  20. Parasitic analysis and π-type Butterworth-Van Dyke model for complementary-metal-oxide-semiconductor Lamb wave resonator with accurate two-port Y-parameter characterizations.

    PubMed

    Wang, Yong; Goh, Wang Ling; Chai, Kevin T-C; Mu, Xiaojing; Hong, Yan; Kropelnicki, Piotr; Je, Minkyu

    2016-04-01

    The parasitic effects from electromechanical resonance, coupling, and substrate losses were collected to derive a new two-port equivalent-circuit model for Lamb wave resonators, especially for those fabricated on silicon technology. The proposed model is a hybrid π-type Butterworth-Van Dyke (PiBVD) model that accounts for the above mentioned parasitic effects which are commonly observed in Lamb-wave resonators. It is a combination of interdigital capacitor of both plate capacitance and fringe capacitance, interdigital resistance, Ohmic losses in substrate, and the acoustic motional behavior of typical Modified Butterworth-Van Dyke (MBVD) model. In the case studies presented in this paper using two-port Y-parameters, the PiBVD model fitted significantly better than the typical MBVD model, strengthening the capability on characterizing both magnitude and phase of either Y11 or Y21. The accurate modelling on two-port Y-parameters makes the PiBVD model beneficial in the characterization of Lamb-wave resonators, providing accurate simulation to Lamb-wave resonators and oscillators. PMID:27131699

  1. Evaluation of whole-animal data using the ion parametric resonance model

    SciTech Connect

    Blanchard, J.P.; House, D.E.; Blackman, C.F.

    1995-09-01

    Changes observed in the behavioral response of land snails from exposure to parallel ac and dc magnetic fields demonstrate limited agreement with the predictions of an interaction model proposed by Lednev and the predictions of a recently proposed ion parametric resonance (IPR) model. However, the inadequate number of reported data points, particularly in a critical exposure range, prevents unambiguous application of either the Lednev or the IPR model.

  2. A comparison of magnetic resonance imaging sequences in evaluating pathological changes in the canine spinal cord.

    PubMed

    Adamiak, Z; Pomianowski, A; Zhalniarovich, Y; Kwiatkowska, M; Jaskólska, M; Bocheńska, A

    2011-01-01

    This paper discusses 28 canine patients subjected to low-field magnetic resonance imaging (MRI) of the spinal cord for neurological indications. The authors describe and compare the used MRI sequences with an indication of the most effective sequences in MRI examinations that require short scanning time. The most effective sequences supporting a quick diagnosis of spinal diseases in dogs were SE (spin echo), FSE (fast spin echo) and 3D HYCE (hybrid contrast enhancement). PMID:21957746

  3. In vitro evaluation of genotoxic effects under magnetic resonant coupling wireless power transfer.

    PubMed

    Mizuno, Kohei; Shinohara, Naoki; Miyakoshi, Junji

    2015-04-01

    Wireless power transfer (WPT) technology using the resonant coupling phenomenon has been widely studied, but there are very few studies concerning the possible relationship between WPT exposure and human health. In this study, we investigated whether exposure to magnetic resonant coupling WPT has genotoxic effects on WI38VA13 subcloned 2RA human fibroblast cells. WPT exposure was performed using a helical coil-based exposure system designed to transfer power with 85.4% efficiency at a 12.5-MHz resonant frequency. The magnetic field at the positions of the cell culture dishes is approximately twice the reference level for occupational exposure as stated in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. The specific absorption rate at the positions of the cell culture dishes matches the respective reference levels stated in the ICNIRP guidelines. For assessment of genotoxicity, we studied cell growth, cell cycle distribution, DNA strand breaks using the comet assay, micronucleus formation, and hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene mutation, and did not detect any significant effects between the WPT-exposed cells and control cells. Our results suggest that WPT exposure under the conditions of the ICNIRP guidelines does not cause detectable cellular genotoxicity. PMID:25853218

  4. Validation of Supervised Automated Algorithm for Fast Quantitative Evaluation of Organ Motion on Magnetic Resonance Imaging

    SciTech Connect

    Prakash, Varuna; Stainsby, Jeffrey A.; Satkunasingham, Janakan; Craig, Tim; Catton, Charles; Chan, Philip; Dawson, Laura; Hensel, Jennifer; Jaffray, David; Milosevic, Michael; Nichol, Alan; Sussman, Marshall S.; Lockwood, Gina; Menard, Cynthia

    2008-07-15

    Purpose: To validate a correlation coefficient template-matching algorithm applied to the supervised automated quantification of abdominal-pelvic organ motion captured on time-resolved magnetic resonance imaging. Methods and Materials: Magnetic resonance images of 21 patients across four anatomic sites were analyzed. Representative anatomic points of interest were chosen as surrogates for organ motion. The point of interest displacements across each image frame relative to baseline were quantified manually and through the use of a template-matching software tool, termed 'Motiontrack.' Automated and manually acquired displacement measures, as well as the standard deviation of intrafraction motion, were compared for each image frame and for each patient. Results: Discrepancies between the automated and manual displacements of {>=}2 mm were uncommon, ranging in frequency of 0-9.7% (liver and prostate, respectively). The standard deviations of intrafraction motion measured with each method correlated highly (r = 0.99). Considerable interpatient variability in organ motion was demonstrated by a wide range of standard deviations in the liver (1.4-7.5 mm), uterus (1.1-8.4 mm), and prostate gland (0.8-2.7 mm). The automated algorithm performed successfully in all patients but 1 and substantially improved efficiency compared with manual quantification techniques (5 min vs. 60-90 min). Conclusion: Supervised automated quantification of organ motion captured on magnetic resonance imaging using a correlation coefficient template-matching algorithm was efficient, accurate, and may play an important role in off-line adaptive approaches to intrafraction motion management.

  5. In Vitro Evaluation of Genotoxic Effects under Magnetic Resonant Coupling Wireless Power Transfer

    PubMed Central

    Mizuno, Kohei; Shinohara, Naoki; Miyakoshi, Junji

    2015-01-01

    Wireless power transfer (WPT) technology using the resonant coupling phenomenon has been widely studied, but there are very few studies concerning the possible relationship between WPT exposure and human health. In this study, we investigated whether exposure to magnetic resonant coupling WPT has genotoxic effects on WI38VA13 subcloned 2RA human fibroblast cells. WPT exposure was performed using a helical coil-based exposure system designed to transfer power with 85.4% efficiency at a 12.5-MHz resonant frequency. The magnetic field at the positions of the cell culture dishes is approximately twice the reference level for occupational exposure as stated in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. The specific absorption rate at the positions of the cell culture dishes matches the respective reference levels stated in the ICNIRP guidelines. For assessment of genotoxicity, we studied cell growth, cell cycle distribution, DNA strand breaks using the comet assay, micronucleus formation, and hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene mutation, and did not detect any significant effects between the WPT-exposed cells and control cells. Our results suggest that WPT exposure under the conditions of the ICNIRP guidelines does not cause detectable cellular genotoxicity. PMID:25853218

  6. Relationship between levodopa-independent symptoms and central atrophy evaluated by magnetic resonance imaging in Parkinson's disease.

    PubMed

    Durif, F; Pollak, P; Hommel, M; Ardouin, C; Le Bas, J F; Crouzet, G; Perret, J

    1992-01-01

    Thirty patients with Parkinson's disease were studied for the purpose of investigation relations between motor symptoms and cerebral atrophy evaluated by magnetic resonance imaging (MRI). Axial symptoms (gait disorder, postural instability and difficulty in arising from a chair), assessed at the time of maximum clinical improvement, were significantly correlated with frontal atrophy, while no correlation was found between the basal parkinsonian disability score and cerebral atrophy. It is suggested that frontal atrophy observed by MRI is linked with axial motor symptoms resulting from non-dopaminergic lesions. The origin of this atrophy is unknown. PMID:1563452

  7. Using an ensemble smoother to evaluate parameter uncertainty of an integrated hydrological model of Yanqi basin

    NASA Astrophysics Data System (ADS)

    Li, Ning; McLaughlin, Dennis; Kinzelbach, Wolfgang; Li, WenPeng; Dong, XinGuang

    2015-10-01

    Model uncertainty needs to be quantified to provide objective assessments of the reliability of model predictions and of the risk associated with management decisions that rely on these predictions. This is particularly true in water resource studies that depend on model-based assessments of alternative management strategies. In recent decades, Bayesian data assimilation methods have been widely used in hydrology to assess uncertain model parameters and predictions. In this case study, a particular data assimilation algorithm, the Ensemble Smoother with Multiple Data Assimilation (ESMDA) (Emerick and Reynolds, 2012), is used to derive posterior samples of uncertain model parameters and forecasts for a distributed hydrological model of Yanqi basin, China. This model is constructed using MIKESHE/MIKE11software, which provides for coupling between surface and subsurface processes (DHI, 2011a-d). The random samples in the posterior parameter ensemble are obtained by using measurements to update 50 prior parameter samples generated with a Latin Hypercube Sampling (LHS) procedure. The posterior forecast samples are obtained from model runs that use the corresponding posterior parameter samples. Two iterative sample update methods are considered: one based on an a perturbed observation Kalman filter update and one based on a square root Kalman filter update. These alternatives give nearly the same results and converge in only two iterations. The uncertain parameters considered include hydraulic conductivities, drainage and river leakage factors, van Genuchten soil property parameters, and dispersion coefficients. The results show that the uncertainty in many of the parameters is reduced during the smoother updating process, reflecting information obtained from the observations. Some of the parameters are insensitive and do not benefit from measurement information. The correlation coefficients among certain parameters increase in each iteration, although they generally

  8. Evaluation of second-order texture parameters for sea ice classification from radar images

    NASA Astrophysics Data System (ADS)

    Shokr, Mohammed E.

    1991-06-01

    With the advent of airborne and spaceborne synthetic aperture radar (SAR) systems, sea ice classification from SAR images has become an important research subject. Since gray tone alone has proven to be of limited capability in differentiating ice types, texture has naturally become an attractive avenue to explore. Accordingly, performance of texture quantification parameters as related to their ability to discriminate ice types has to be examined. SAR image appearance depends on radar parameters involved in the image construction procedures from the doppler history record. Therefore the feasibility of using universal texture/ice type relationships that hold for all combinations of radar parameters also has to be investigated. To that end, imagery data from three different SAR systems were used in this study. Five conventional texture parameters, derived from the gray level co-occurrence matrix (GLCM), were examined. Two of them were modified to ensure their invariant character under linear gray tone transformations. Results indicated that all parameters were highly correlated. The parameters did not, in general, vary with the computational variables used in generating co-occurrence matrices. Ice types can be identified uniquely by the mean value of any texture parameter. The relatively high variability of texture parameters, however, confuses ice discrimination, particularly of smoother ice types. Ice classification was conducted using a per-pixel maximum likelihood supervised scheme. When texture was combined with gray tone, the overall average classification accuracy was improved. Texture was successful in improving the classification accuracy of multiyear ice but was less promising in discriminating first-season ice types. The best two GLCM texture parameters, according to the computed overall average classification accuracies, were the inverse difference moment and the entropy. A brief description of GLCM texture parameters as related to ice's physical

  9. Evaluation of Magnetic Resonance Imaging-Compatible Needles and Interactive Sequences for Musculoskeletal Interventions Using an Open High-Field Magnetic Resonance Imaging Scanner

    SciTech Connect

    Wonneberger, Uta; Schnackenburg, Bernhard; Streitparth, Florian Walter, Thula Rump, Jens Teichgraeber, Ulf K. M.

    2010-04-15

    In this article, we study in vitro evaluation of needle artefacts and image quality for musculoskeletal laser-interventions in an open high-field magnetic resonance imaging (MRI) scanner at 1.0T with vertical field orientation. Five commercially available MRI-compatible puncture needles were assessed based on artefact characteristics in a CuSO4 phantom (0.1%) and in human cadaveric lumbar spines. First, six different interventional sequences were evaluated with varying needle orientation to the main magnetic field B0 (0{sup o} to 90{sup o}) in a sequence test. Artefact width, needle-tip error, and contrast-to-noise ratio (CNR) were calculated. Second, a gradient-echo sequence used for thermometric monitoring was assessed and in varying echo times, artefact width, tip error, and signal-to-noise ratio (SNR) were measured. Artefact width and needle-tip error correlated with needle material, instrument orientation to B0, and sequence type. Fast spin-echo sequences produced the smallest needle artefacts for all needles, except for the carbon fibre needle (width <3.5 mm, tip error <2 mm) at 45{sup o} to B0. Overall, the proton density-weighted spin-echo sequences had the best CNR (CNR{sub Muscle/Needle} >16.8). Concerning the thermometric gradient echo sequence, artefacts remained <5 mm, and the SNR reached its maximum at an echo time of 15 ms. If needle materials and sequences are accordingly combined, guidance and monitoring of musculoskeletal laser interventions may be feasible in a vertical magnetic field at 1.0T.

  10. Treatment of Locally Advanced Vaginal Cancer With Radiochemotherapy and Magnetic Resonance Image-Guided Adaptive Brachytherapy: Dose-Volume Parameters and First Clinical Results

    SciTech Connect

    Dimopoulos, Johannes C.A.; Schmid, Maximilian P.; Fidarova, Elena; Berger, Daniel; Kirisits, Christian; Poetter, Richard

    2012-04-01

    Purpose: To investigate the clinical feasibility of magnetic resonance image-guided adaptive brachytherapy (IGABT) for patients with locally advanced vaginal cancer and to report treatment outcomes. Methods and Materials: Thirteen patients with vaginal cancer were treated with external beam radiotherapy (45-50.4 Gy) plus IGABT with or without chemotherapy. Distribution of International Federation of Gynecology and Obstetrics stages among patients were as follows: 4 patients had Stage II cancer, 5 patients had Stage III cancer, and 4 patients had Stage IV cancer. The concept of IGABT as developed for cervix cancer was transferred and adapted for vaginal cancer, with corresponding treatment planning and reporting. Doses were converted to the equivalent dose in 2 Gy, applying the linear quadratic model ({alpha}/{beta} = 10 Gy for tumor; {alpha}/{beta} = 3 for organs at risk). Endpoints studied were gross tumor volume (GTV), dose-volume parameters for high-risk clinical target volume (HRCTV), and organs at risk, local control (LC), adverse side effects, and survival. Results: The mean GTV ({+-} 1 standard deviation) at diagnosis was 45.3 ({+-}30) cm{sup 3}, and the mean GTV at brachytherapy was 10 ({+-}14) cm{sup 3}. The mean D90 for the HRCTV was 86 ({+-}13) Gy. The mean D2cc for bladder, urethra, rectum, and sigmoid colon were 80 ({+-}20) Gy, 76 ({+-}16) Gy, 70 ({+-}9) Gy, and 60 ({+-}9) Gy, respectively. After a median follow-up of 43 months (range, 19-87 months), one local recurrence and two distant metastases cases were observed. Actuarial LC and overall survival rates at 3 years were 92% and 85%. One patient with Stage IVA and 1 patient with Stage III disease experienced fistulas (one vesicovaginal, one rectovaginal), and 1 patient developed periurethral necrosis. Conclusions: The concept of IGABT, originally developed for treating cervix cancer, appears to be applicable to vaginal cancer treatment with only minor adaptations. Dose-volume parameters for HRCTV and

  11. Ultrasonic evaluation of the Jahn-Teller effect parameters. Application to ZnSe:Cr2 +

    NASA Astrophysics Data System (ADS)

    Gudkov, V. V.; Bersuker, I. B.; Zhevstovskikh, I. V.; Korostelin, Yu V.; Landman, A. I.

    2011-03-01

    A method is constructed that uses ultrasonic experiments to evaluate the parameters of the Jahn-Teller (JT) effect in impurity centers in crystals. The method is based on measurements of temperature dependent attenuation and phase velocity and does not require assumptions about mechanisms of relaxation. The results are illustrated by measurements performed on the impurity system ZnSe:Cr2 + , in which the Cr2 + ion has a threefold degenerate T term in the ground state, subject to the T\\otimes (e+t_2) JT problem. Ultrasound propagation anomalies show that the main JT distortions of the tetrahedral environment of the Cr2 + ion are of tetragonal E type and hence the lowest branch of the adiabatic potential energy surface (APES) is formed in accordance with the T\\otimes e problem. With dopant concentration 3.8 × 1018 cm - 3 the modulus of the constant of linear vibronic coupling to tetragonal E type vibrations is determined by two independent experiments: |FE| = 5.49 × 10 - 5 dyn revealed from attenuation measurements, while a slightly different value |FE| = 5.57 × 10 - 5 dyn emerges from phase velocity measurements. Contributions of other active vibronic modes to the elastic modulus Cl = (C11 + C12 + 2C44)/2 are analyzed and it is shown that the influence of the totally symmetric mode is negligible. Using additional information about this system obtained from independent sources, we also estimated the primary force constant in the E direction (KE≈(1.4-4.2) × 104 dyn cm - 1) and orthorhombic and trigonal saddle points of the APES in the five-dimensional space of the tetragonal and trigonal coordinates, their stabilization energies being EJTO≈81-450 cm - 1 and EJTT≈48-417 cm - 1, respectively (the variations of the KE, EJTO and EJTT values are due to different literature data for EJTE). With these data the APES of the JT linear T\\otimes (e+t_2) problem for the Cr2 + ion in the ZnSe:Cr2 + system is revealed.

  12. Bench-scale evaluation of drinking water treatment parameters on iron particles and water quality.

    PubMed

    Rahman, M Safiur; Gagnon, Graham A

    2014-01-01

    Discoloration of water resulting from suspended iron particles is one of the main customer complaints received by water suppliers. However, understanding of the mechanisms of discoloration as well as role of materials involved in the process is limited. In this study, an array of bench scale experiments were conducted to evaluate the impact of the most common variables (pH, PO4, Cl2 and DOM) on the properties of iron particles and suspensions derived from the oxygenation of Fe(II) ions in NaHCO3 buffered synthetic water systems. The most important factors as well as their rank influencing iron suspension color and turbidity formation were identified for a range of water quality parameters. This was accomplished using a 2(4) full factorial design approach at a 95% confidence level. The statistical analysis revealed that phosphate was found to be the most significant factor to alter color (contribution: 37.9%) and turbidity (contribution: 45.5%) in an iron-water system. A comprehensive study revealed that phosphate and chlorine produced iron suspension with reduced color and turbidity, made ζ-potential more negative, reduced the average particle size, and increased iron suspension stability. In the presence of DOM, color was observed to increase but a reverse trend was observed to decrease the turbidity and to alter particle size distribution. HPSEC results suggest that higher molecular weight fractions of DOM tend to adsorb onto the surfaces of iron particles at early stages, resulting in alteration of the surface charge of iron particles. This in turn limits particles aggregation and makes iron colloids highly stable. In the presence of a phosphate based corrosion inhibitor, this study demonstrated that color and turbidity resulting from suspended iron were lower at a pH value of 6.5 (compared to pH of 8.5). The same trend was observed in presence of DOM. This study also suggested that iron colloid suspension color and turbidity in chlorinated drinking water

  13. Simplified evaluation of PEM-fuel cells by reduction of measurement parameters and using optimised measurement algorithms

    NASA Astrophysics Data System (ADS)

    Purmann, M.; Styczynski, Z.

    PEM-fuel cells operated with hydrogen and air offer promising possibilities for the decentralised energy supply in stationary and mobile applications. But, there is still a remarkable need for more research for the optimisation of the single components even though the research, especially the development of membrane-electrode units and bipolar plates, has made considerable progress within recent years. This also applies to the definition of suitable test algorithms and parameters for recording the characteristics as well as long time tests. The investigations for single cells or stacks can thereby be subdivided into investigations in the stationary and the dynamic state. This paper shows a simplified approach for the evaluation and modelling of PEM-fuel cell stacks for the stationary state. Based on the definition of regression approaches for the dependence of several parameters the number of stack parameters is initially reduced to a sufficient number of values. The remaining parameters are used to form an energy model which can be combined with the energy models of auxiliary components like air compressors and sinus inverters [1]. Algorithms for recording the parameters still have to be defined. Therefore, the tests for the preparation of a set of characteristic curves can be very time consuming because of the multitude of variable parameters. This paper presents and discusses optimised measurement algorithms for the evaluation of PEM-fuel cell stacks to reduce this time exposure.

  14. Quantitative non-destructive evaluation of composite materials based on ultrasonic parameters

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1987-01-01

    Research into the nondestructive evaluation of advanced reinforced composite laminates is summarized. The applicability of the Framers-Kronig equations to the nondestructive evaluation of composite materials is described.

  15. Approximate evaluation of loading parameters in composite materials with strong shock waves

    SciTech Connect

    Pai, V.V.; Kuz`min, G.E.; Yakovlev, I.V.

    1995-11-01

    A simple and sufficiently accurate method is proposed for estimating the parameters of shockwave loading of porous materials under conditions of complete compaction of the material to the density of a monolith.

  16. GRS Method for Uncertainties Evaluation of Parameters in a Prospective Fast Reactor

    NASA Astrophysics Data System (ADS)

    Peregudov, A.; Andrianova, O.; Raskach, K.; Tsibulya, A.

    2014-04-01

    A number of recent studies have been devoted to the uncertainty estimation of reactor calculation parameters by the GRS (Generation Random Sampled) method. This method is based on direct sampling input data resulting in formation of random sets of input parameters which are used for multiple calculations. Once these calculations are performed, statistical processing of the calculation results is carried out to determine the mean value and the variance of each calculation parameter of interest. In our study this method is used to estimate the uncertainty of calculation parameters (keff, power density, dose rate) of a prospective sodium-cooled fast reactor. Neutron transport calculations were performed by the nodal diffusion code TRIGEX and Monte Carlo code MMK.

  17. Remote detection of trace effluents using Resonance Raman spectroscopy: Field results and evaluation

    SciTech Connect

    Sedlacek, A.J.; Chen, C.L.

    1995-10-01

    Resonance Raman spectroscopy (RRS) possesses many characteristics that are important for detecting, identifying and monitoring chemical effluents. Raman scattering is a coherent, inelastic, two-photon scattering process where an exciting photon of energy h{nu} promotes a molecule to a virtual level and the subsequently emitted photon is shifted in frequency in accordance with the rotational-vibrational structure of the irradiated species, thereby providing a unique fingerprint of the molecule. Under resonance enhancement, the Raman scattering cross-sections have been observed to increase up to 6 orders of magnitude above the normal scattering cross-sections, thereby providing the practical basis for a remote chemical sensor. Some of the other advantages that a Raman sensor possesses are: (1) very high selectivity (chemical specific fingerprints), (2) independence of the spectral fingerprint on the excitation wavelength (ability to monitor in the solar blind region), (3) chemical mixture fingerprints are the sum of its individual components (no spectral cross-talk), (4) near independence of the Raman fingerprint to its physical state (very similar spectra for gas, liquid, solid or solutions), (5) no absolute calibration is necessary because all Raman signals observed from a given species can be compared with the Raman signal for N{sub 2}, whose concentration is known very accurately, and (6) insensitivity of the Raman signature to environmental conditions (no quenching, or interference from water vapor). In this presentation, the technology of resonance Raman spectroscopy as applied to the detection of narcotics production activities will be presented along with some recent experimental results.

  18. Evaluation of immunological and physiological parameters associated with an infectious bovine rhinotracheitis viral challenge in beef steers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To evaluate the effects infectious bovine rhinotracheitis virus (IBRV) has on immunological and physiological parameters of cattle; 12 Angus crossbred steers (228.82 ± 22.15 kg) were randomly assigned to either a Control group or an IBRV challenged group. Prior to the challenge, steers were fitted w...

  19. FitSpace explorer: an algorithm to evaluate multidimensional parameter space in fitting kinetic data.

    PubMed

    Johnson, Kenneth A; Simpson, Zachary B; Blom, Thomas

    2009-04-01

    Fitting several sets of kinetic data directly to a model based on numerical integration provides the best method to extract kinetic parameters without relying on the simplifying assumptions required to achieve analytical solutions of rate equations. However, modern computer programs make it too easy to enter an overly complex model, and standard error analysis grossly underestimates errors when a system is underconstrained and fails to reveal the full degree to which multiple parameters are linked through the complex relationships common in kinetic data. Here we describe the application of confidence contour analysis obtained by measuring the dependence of the sum square error on each pair of parameters while allowing all remaining parameters to be adjusted in seeking the best fit. The confidence contours reveal complex relationships between parameters and clearly outline the space over which parameters can vary (the "FitSpace"). The utility of the method is illustrated by examples of well-constrained fits to published data on tryptophan synthase and the kinetics of oligonucleotide binding to a ribozyme. In contrast, analysis of alanine racemase clearly refutes claims that global analysis of progress curves can be used to extract the free energy profiles of enzyme-catalyzed reactions.

  20. Modern techniques of magnetic resonance in the evaluation of primary central nervous system lymphoma: contributions to the diagnosis and differential diagnosis

    PubMed Central

    da Rocha, Antonio José; Sobreira Guedes, Bruno Vasconcelos; da Silveira da Rocha, Talita Maira Bueno; Maia Junior, Antonio Carlos Martins; Chiattone, Carlos Sérgio

    2015-01-01

    In addition to findings from conventional magnetic resonance imaging, modern magnetic resonance imaging techniques have provided important information about tumor metabolism, in vivo metabolite formation, water molecule diffusion, microvascular density, and blood-brain barrier permeability, all of which have improved the in vivo diagnostic accuracy of this method in the evaluation of primary central nervous system lymphoma. These nonconventional magnetic resonance techniques are useful in the clinical practice because they enhance conventional magnetic resonance imaging by reinforcing the possibility of a diagnosis and by allowing the early detection of disease recurrence. This report is a review of the most relevant contributions of nonconventional magnetic resonance techniques to the imaging diagnosis of primary central nervous system lymphoma, the differential diagnosis of this disease, and the prognosis of patients. This paper aims to describe a wide range of presentations of primary central nervous system lymphoma, their appearance in imaging, and the differential diagnoses of this disease. PMID:26969774

  1. Evaluation of moving-coil loudspeaker and passive radiator parameters using normal-incidence sound transmission measurements: theoretical developments.

    PubMed

    Leishman, Timothy W; Anderson, Brian E

    2013-07-01

    The parameters of moving-coil loudspeaker drivers are typically determined using direct electrical excitation and measurement. However, as electro-mechano-acoustical devices, their parameters should also follow from suitable mechanical or acoustical evaluations. This paper presents the theory of an acoustical method of excitation and measurement using normal-incidence sound transmission through a baffled driver as a plane-wave tube partition. Analogous circuits enable key parameters to be extracted from measurement results in terms of open and closed-circuit driver conditions. Associated tools are presented that facilitate adjacent field decompositions and derivations of sound transmission coefficients (in terms of driver parameters) directly from the circuits. The paper also clarifies the impact of nonanechoic receiving tube terminations and the specific benefits of downstream field decompositions.

  2. Profiling human blood serum metabolites by nuclear magnetic resonance spectroscopy: a comprehensive tool for the evaluation of hemodialysis efficiency.

    PubMed

    Kromke, Marika; Palomino-Schätzlein, Martina; Mayer, Horst; Pfeffer, Stefan; Pineda-Lucena, Antonio; Luy, Burkhard; Hausberg, Martin; Muhle-Goll, Claudia

    2016-05-01

    Hemodialysis remains the standard therapy to treat patients affected with end-stage renal disease by removing metabolites accumulated in blood plasma. The efficiency of hemodialysis is mainly monitored by urea clearance, which is routinely checked in clinical laboratory practice. However, there is mounting evidence that the clearance behavior of selected single metabolites is not sufficient to predict long-term outcome of treatment. To address this problem, we evaluated the potential of nuclear magnetic resonance spectroscopy for monitoring hemodialysis efficiency by comprehensive profiling of blood serum metabolites. We carried out a pilot study with a cohort of end-stage chronic kidney disease patients (n = 29), analyzing their serum prior and immediately after hemodialysis. To account for supposed variability in the accumulation of metabolites and efficiency of hemodialysis, patients' blood sera were repeatedly collected over a period of several months. Our results revealed that the metabolic profile in terms of concentrations varied considerably between patients but was comparably constant on the patient's level over the period of 4 months. Interestingly, also the individual clearance of the metabolites was characteristic for each patient. Thus, it is conceivable that the observed patient-dependent clearance patterns reflect to some extent the patients' long-term perspectives. We conclude that nuclear magnetic resonance spectroscopy is an optimal tool to complement traditional clinical methods based on a single variable, providing comprehensive and much more global information, which is crucial for patient evaluation and the development of improved treatments of kidney failure.

  3. Utilizing magnetic resonance imaging logs, openhole logs, and sidewall core analyses to evaluate shaly sands for water-free production

    SciTech Connect

    Taylor, D.A.; Morganti, J.K.; White, H.J. ); Noblett, B.R. )

    1996-01-01

    Nuclear magnetic resonance (NMR) logging using the new C Series Magnetic Resonance Imaging Log (MRIL) system is rapidly enhancing formation evaluation throughout the industry. By measuring irreducible water saturations, permeabilities, and effective porosities, MRIL data can help petrophysicists evaluate low-resistivity pays. In these environments, conventional openhole logs may not define all of the pay intervals. The MRIL system can also reduce the number of unnecessary completions in zones of potentially high water cut. MRIL tool theory and log presentations used with conventional logs and sidewall cores are presented along with field examples. Scanning electron microscope (SEM) analysis shows good correlation of varying grain size in sandstones with the T2 distribution and bulk volume irreducible water determined from the MRIL measurements. Analysis of each new well drilled in the study area shows how water-free production zones were defined. Because the MRIL data were not recorded on one of the wells, predictions from the conventional logs and the MRIL data collected on the other two wells were used to estimate productive zones in the first well. Discussion of additional formation characteristics, completion procedures, actual production, and predicted producibility of the shaly sands is presented. Integrated methodologies resulted in the perforation of 3 new wells for a gross initial potential of 690 BOPD and 0 BWPD.

  4. Utilizing magnetic resonance imaging logs, openhole logs, and sidewall core analyses to evaluate shaly sands for water-free production

    SciTech Connect

    Taylor, D.A.; Morganti, J.K.; White, H.J.; Noblett, B.R.

    1996-12-31

    Nuclear magnetic resonance (NMR) logging using the new C Series Magnetic Resonance Imaging Log (MRIL) system is rapidly enhancing formation evaluation throughout the industry. By measuring irreducible water saturations, permeabilities, and effective porosities, MRIL data can help petrophysicists evaluate low-resistivity pays. In these environments, conventional openhole logs may not define all of the pay intervals. The MRIL system can also reduce the number of unnecessary completions in zones of potentially high water cut. MRIL tool theory and log presentations used with conventional logs and sidewall cores are presented along with field examples. Scanning electron microscope (SEM) analysis shows good correlation of varying grain size in sandstones with the T2 distribution and bulk volume irreducible water determined from the MRIL measurements. Analysis of each new well drilled in the study area shows how water-free production zones were defined. Because the MRIL data were not recorded on one of the wells, predictions from the conventional logs and the MRIL data collected on the other two wells were used to estimate productive zones in the first well. Discussion of additional formation characteristics, completion procedures, actual production, and predicted producibility of the shaly sands is presented. Integrated methodologies resulted in the perforation of 3 new wells for a gross initial potential of 690 BOPD and 0 BWPD.

  5. P-31 magnetic resonance spectroscopy and near-infrared spectroscopy provide unique quantitative data for evaluation of exercising muscles

    NASA Astrophysics Data System (ADS)

    Park, Jane H.; Golwyn, Daniel; Olsen, Nancy J.; Newman, John H.; Powers, Alvin C.; Davis, Beverly C.; Rader, Kara; Chance, Britton

    1994-09-01

    P-31 magnetic resonance spectroscopy (MRS) and near-infra spectroscopy (NIRS) have been used to characterize the dynamic aspects of human muscle contraction. P-31 MRS is a non- invasive method for measuring ATP, phosphocreatine (PCr), and pH in exercising muscles and thereby provides information regarding oxidative and glycolytic capacities for generating high energy phosphate compounds. NIRS evaluates kinetic changes in oxygen levels in muscles during exercise and recovery. These two methods provide unique quantitative data for studies of normal muscle contraction and for more complex investigations of muscle diseases. Non-invasive MRS and NIRS examinations are readily repeatable and yield important data for longitudinal patient evaluation and therapeutic management.

  6. Magnetic resonance imaging is superior to radiography in evaluating spinal cord trauma in three bald eagles (Haliaeetus leucocephalus).

    PubMed

    Stauber, Erik; Holmes, Shannon; DeGhetto, Darlene L; Finch, Nickol

    2007-09-01

    Three bald eagles (Haliaeetus leucocephalus) found along highways and unable to fly were presented for evaluation. All eagles exhibited sternal recumbency, as well as flaccid hind limb and tail paralysis. Vertebral column and spinal cord trauma were suspected as the cause. One bird died, whereas the remaining 2 birds were stabilized for diagnostic imaging studies. All 3 birds were evaluated by radiography and magnetic resonance imaging (MRI) for diagnosis and for prognosis in the live birds. Radiographic findings in all 3 birds were inconclusive, whereas MRI results showed extensive damage of the spinal cord and vertebral column, precluding functional recovery. The 2 surviving birds were euthanatized. In all birds, MRI assessments correlated well with necropsy and histopathologic findings.

  7. Magnetic resonance imaging is superior to radiography in evaluating spinal cord trauma in three bald eagles (Haliaeetus leucocephalus).

    PubMed

    Stauber, Erik; Holmes, Shannon; DeGhetto, Darlene L; Finch, Nickol

    2007-09-01

    Three bald eagles (Haliaeetus leucocephalus) found along highways and unable to fly were presented for evaluation. All eagles exhibited sternal recumbency, as well as flaccid hind limb and tail paralysis. Vertebral column and spinal cord trauma were suspected as the cause. One bird died, whereas the remaining 2 birds were stabilized for diagnostic imaging studies. All 3 birds were evaluated by radiography and magnetic resonance imaging (MRI) for diagnosis and for prognosis in the live birds. Radiographic findings in all 3 birds were inconclusive, whereas MRI results showed extensive damage of the spinal cord and vertebral column, precluding functional recovery. The 2 surviving birds were euthanatized. In all birds, MRI assessments correlated well with necropsy and histopathologic findings. PMID:18087936

  8. Quantitative Evaluation of Left Ventricular Wall Motion in Patient with Coronary Artery Bypass Grafting Using Magnetic Resonance Tagging Technique

    NASA Astrophysics Data System (ADS)

    Inaba, Tadashi; Nakano, Takahiro; Tsutsumi, Masakazu; Kawasaki, Shingo; Kinosada, Yasutomi; Tokuda, Masataka

    Left ventricular wall motions during systole were investigated from a mechanical perspective by using a magnetic resonance tagging technique. Subjects were 7 patients with coronary artery bypass grafting (CABG). First, by analyzing strain in the left ventricular wall, cardiac contractility was evaluated in the patients with CABG. Next, by calculating displacement in the myocardial wall, paradoxical movements following CABG were quantitatively evaluated. Strain analysis showed local decreases in circumferential strain in 4 of 7 subjects. The results of displacement analysis clarified that following CABG, the degree of radial displacement was small in the septal wall and large in the lateral wall, and circumferential displacement towards the septal wall occurred in the anterior and posterior walls. Since this behavior was seen in both reduced and normal cardiac contractility groups, paradoxical movements in the present patients were not caused by reduced cardiac contractility, but rather by rigid-body motion of the entire heart.

  9. Endometrium evaluation with high-field (3-Tesla) magnetic resonance imaging in patients submitted to uterine leiomyoma embolization

    PubMed Central

    Jacobs, Monica Amadio Piazza; Nasser, Felipe; Zlotnik, Eduardo; Messina, Marcos de Lorenzo; Baroni, Ronaldo Hueb

    2013-01-01

    ABSTRACT Objective: To evaluate the endometrial alterations related to embolization of uterine arteries for the treatment of symptomatic uterine leiomyomatosis (pelvic pain and/or uterine bleeding) by means of high-field (3-Tesla) magnetic resonance. Methods: This is a longitudinal and prospective study that included 94 patients with a clinical and imaging diagnosis of symptomatic uterine leiomyomatosis, all of them treated by embolization of the uterine arteries. The patients were submitted to evaluations by high-field magnetic resonance of the pelvis before and 6 months after the procedure. Specific evaluations were made of the endometrium on the T2-weighted sequences, and on the T1-weighted sequences before and after the intravenous dynamic infusion of the paramagnetic contrast. In face of these measures, statistical analyses were performed using Student's t test for comparison of the results obtained before and after the procedure. Results: An average increase of 20.9% was noted in the endometrial signal on T2-weighted images obtained after the uterine artery embolization procedure when compared to the pre-procedure evaluation (p=0.0004). In the images obtained with the intravenous infusion of paramagnetic contrast, an average increase of 18.7% was noted in the post-embolization intensity of the endometrial signal, compared to the pre-embolization measure (p<0.035). Conclusion: After embolization of the uterine arteries, there was a significant increase of the endometrial signal on the T2-weighted images and on the post-contrast images, inferring possible edema and increased endometrial flow. Future studies are needed to assess the clinical impact of these findings. PMID:23579745

  10. Model inversion by parameter fit using NN emulating the forward model: evaluation of indirect measurements.

    PubMed

    Schiller, Helmut

    2007-05-01

    The usage of inverse models to derive parameters of interest from measurements is widespread in science and technology. The operational usage of many inverse models became feasible just by emulation of the inverse model via a neural net (NN). This paper shows how NNs can be used to improve inversion accuracy by minimizing the sum of error squares. The procedure is very fast as it takes advantage of the Jacobian which is a byproduct of the NN calculation. An example from remote sensing is shown. It is also possible to take into account a non-diagonal covariance matrix of the measurement to derive the covariance matrix of the retrieved parameters.

  11. The Effect of Temperature Dependent Frequency Factor on the Evaluated Trapping Parameters of TSL Glow Curves

    NASA Astrophysics Data System (ADS)

    Yazici, A. N.; Öztürk, Z.

    1998-01-01

    The effect of temperature dependency on frequency factor and its relationship to trapping parameters is discussed by using the peak shape method. The coefficients appearing in the peak shape formula for the calculation of the activation energy have been determined and tabulated for the symmetry factor mg(X) for x=0.50 and 0.75 of the peak intensity. It is found that significant errors occur in the value of the trapping parameters if the temperature dependecy of the frequency factor is not consider.

  12. Study of the influence of reference system in surface finishing parameters evaluation

    NASA Astrophysics Data System (ADS)

    Sanz, A.; Fernández, R.; Pindado, S.; Núñez, P.

    2012-04-01

    In the present paper the influence of the reference system with regard to the characterization of the surface finishing is analyzed. The effect of the reference system's choice on the most representative surface finishing parameters (e.g. roughness average Ra and root mean square values Rq) is studied. The study can also be applied to their equivalent parameters in waviness and primary profiles. Based on ISO and ASME standards, three different types of regression lines (central, mean and orthogonal) are theoretically and experimentally analyzed, identifying the validity and applicability fields of each one depending on profile's geometry.

  13. Simultaneous evaluation of acoustic nonlinearity parameter and attenuation coefficients using the finite amplitude method

    SciTech Connect

    Zhang, Shuzeng; Li, Xiongbing; Jeong, Hyunjo Cho, Sungjong

    2015-07-15

    A novel method to determine acoustic parameters involved in measuring the nonlinearity parameter of fluids or solids is proposed. The approach is based on the measurement of fundamental and second harmonic pressures with a calibrated receiver, and on a nonlinear least squares data-fitting to multi-Gaussian beam (MGB) equations which explicitly define the attenuation and diffraction effects in the quasilinear regime. Results obtained in water validate the proposed method. The choice of suitable source pressure is discussed with regard to the quasilinear approximation involved. The attenuation coefficients are also acquired in nonlinear regime and their relations are discussed.

  14. Supplementation of Antipsychotic Treatment with the Amino Acid Sarcosine Influences Proton Magnetic Resonance Spectroscopy Parameters in Left Frontal White Matter in Patients with Schizophrenia

    PubMed Central

    Strzelecki, Dominik; Podgórski, Michał; Kałużyńska, Olga; Gawlik-Kotelnicka, Oliwia; Stefańczyk, Ludomir; Kotlicka-Antczak, Magdalena; Gmitrowicz, Agnieszka; Grzelak, Piotr

    2015-01-01

    Dysfunction of the glutamatergic system, the main stimulating system in the brain, has a major role in pathogenesis of schizophrenia. The frontal white matter (WM) is partially composed of axons from glutamatergic pyramidal neurons and glia with glutamatergic receptors. The natural amino acid sarcosine, a component of a normal diet, inhibits the glycine type 1 transporter, increasing the glycine level. Thus, it modulates glutamatergic transmission through the glutamatergic ionotropic NMDA (N-methyl-d-aspartate) receptor, which requires glycine as a co-agonist. To evaluate the concentrations of brain metabolites (NAA, N-acetylaspartate; Glx, complex of glutamate, glutamine, and γ-aminobutyric acid (GABA); mI, myo-inositol; Cr, creatine; Cho, choline) in the left frontal WM, Proton Nuclear Magnetic Resonance (1H-NMR) spectroscopy was used. Twenty-five patients randomly chosen from a group of fifty with stable schizophrenia (DSM-IV-TR) and dominant negative symptoms, who were receiving antipsychotic therapy, were administered 2 g of sarcosine daily for six months. The remaining 25 patients received placebo. Assignment was double blinded. 1H-NMR spectroscopy (1.5 T) was performed twice: before and after the intervention. NAA, Glx and mI were evaluated as Cr and Cho ratios. All patients were also assessed twice with the Positive and Negative Syndrome Scale (PANSS). Results were compared between groups and in two time points in each group. The sarcosine group demonstrated a significant decrease in WM Glx/Cr and Glx/Cho ratios compared to controls after six months of therapy. In the experimental group, the final NAA/Cr ratio significantly increased and Glx/Cr ratio significantly decreased compared to baseline values. Improvement in the PANSS scores was significant only in the sarcosine group. In patients with schizophrenia, sarcosine augmentation can reverse the negative effect of glutamatergic system overstimulation, with a simultaneous beneficial increase of NAA

  15. [New technique of magnetic resonance imaging to evaluate peripheral circulation in diabetic patients].

    PubMed

    Suzuki, Eiji

    2006-11-01

    Waveform analysis at the popliteal artery using the new technique of gated two-dimensional cine-mode phase-contrast magnetic resonance imaging is beneficial to assess peripheral circulation in both normal and diseased arteries. The normal subjects had a typically triphasic waveform, which could be clearly separated into systolic, and early and late diastolic phases of the cardiac cycle. Diabetic patients are reported to have two types of insufficient arterial blood flow to the lower limbs associated with the vessel wall properties. Firstly, patients with atherosclerotic occlusion in the lower-leg arteries distal to the aortic bifurcation, resulting in a low ankle-brachial index, show an abnormal monophasic waveform. Secondly, patients with stiffer arteries characteristically show abnormal flow reversal in late diastole, suggesting higher vascular resistance.

  16. Surface Plasmon Resonance (SPR) for the Evaluation of Shear-Force-Dependent Bacterial Adhesion

    PubMed Central

    Zagorodko, Oleksandr; Bouckaert, Julie; Dumych, Tetiana; Bilyy, Rostyslav; Larroulet, Iban; Yanguas Serrano, Aritz; Alvarez Dorta, Dimitri; Gouin, Sebastien G.; Dima, Stefan-Ovidiu; Oancea, Florin; Boukherroub, Rabah; Szunerits, Sabine

    2015-01-01

    The colonization of Escherichia coli (E. coli) to host cell surfaces is known to be a glycan-specific process that can be modulated by shear stress. In this work we investigate whether flow rate changes in microchannels integrated on surface plasmon resonance (SPR) surfaces would allow for investigating such processes in an easy and high-throughput manner. We demonstrate that adhesion of uropathogenic E. coli UTI89 on heptyl α-d-mannopyranoside-modified gold SPR substrates is minimal under almost static conditions (flow rates of 10 µL·min−1), and reaches a maximum at flow rates of 30 µL·min−1 (≈30 mPa). This concept is applicable to the investigation of any ligand-pathogen interactions, offering a robust, easy, and fast method for screening adhesion characteristics of pathogens to ligand-modified interfaces. PMID:26018780

  17. Early evaluation of magnetic resonance imaging guided focused ultrasound sonication in the treatment of uterine fibroids

    PubMed Central

    Himabindu, Y.; Sriharibabu, M.; Nyapathy, Vinay; Mishra, Anindita

    2014-01-01

    Background & objectives: Uterine leiomyomas (fibroids) are common cause of morbidity in women of reproductive age group. High intensity focused ultrasound with the imaging guidance of magnetic resonance imaging (MRI) known as magnetic resonance guided focused ultrasound sonication (MRgFUS) is now available. However, there are no available studies with this non invasive modality of treatment in Indian subjects. The objective of this study was to determine the safety and clinical efficacy of MRgFUS in the treatment of uterine fibroids. Methods: This prospective study included 32 consecutive women with clinically symptomatic uterine fibroids who were treated with MRgFUS from February 2011 to October 2011. Pre and post treatment symptom severity scores (SSS) were assessed at the time of enrolment and at one, three and six months follow up using a validated uterine fibroid symptom - quality of life questionnaire (UFS-QOL). Pre and post treatment fibroid volumes were compared immediately after treatment and at six months follow up using contrast enhanced MRI scan. Non perfused volume (NPV) ratios were calculated and correlated with fibroid volume reductions immediately after the treatment and at the end of six months follow up. Results: This procedure was well tolerated by the patients and procedure related adverse effects were non significant. Significant reductions in SSS were seen at one, three and six month intervals after the treatment (P<0.01). Significant reductions were noticed in fibroid volumes at six months follow up compared to pretreatment fibroid volumes (P<0.01). Significant positive correlations were observed between NPV ratios and reduction in fibroid volumes at six months follow-up (r=0.659, P<0.01). Interpretation & conclusions: MRgFUS is relatively a safe and effective non invasive treatment modality for treating uterine fibroids in selected patients. Its long term efficacy is yet to be tested and compared with other available minimally invasive

  18. Evaluation of the effects of photodynamic therapy with phosphorus 31 magnetic resonance spectroscopy

    PubMed Central

    Nishiwaki, M; Fujise, Y; Yoshida, T O; Matsuzawa, E; Nishiwaki, Y

    1999-01-01

    Magnetic resonance spectroscopy in situ was used to study changes in phosphorus 31 metabolism after photodynamic therapy (PDT) of transplanted HeLa cell tumours. Tumours were irradiated 2 h after administration of ATX-S10 (8-formyloximethylidene-7-hydroxy-3-ethenyl-2,7,12,18, tetramethyl-porphyrin-13,17-bispropionil aspartate), a new photosensitizer and chlorin derivative. Nuclear magnetic resonance spectra were measured prior to illumination and 1, 3, 7, 14, 21 and 28 days after PDT on each mouse. A drastic decrease in adenosine triphosphate (ATP) and a concomitant increase in inorganic phosphate (Pi) were evident on the first day after PDT in all cases. The β-ATP/total phosphate (P) ratio was 0.64 ± 0.29% (average ± s.d.) in complete response, 0.67 ± 0.30% in recurrence and 2.45 ± 0.93% in partial response. Comparison of this ratio to the histological findings revealed that the β-ATP/total P ratio reflects the HeLa cell tumours which survived PDT. In other words, partial response on the one hand was distinguished from complete response and recurrence on the other with this ratio 1 day after PDT (P < 0.05). In addition, the ratio of phosphomonoester (PME) to Pi rose beyond 1.0 when macroscopic recurrence occurred, while it stayed under 1.0 in complete response. This finding suggests that the recurrence of HeLa cell tumours can be detected by the PME/Pi ratio. © 1999 Cancer Research Campaign PMID:10389989

  19. Evaluation of sample preparation methods for nuclear magnetic resonance metabolic profiling studies with Eisenia fetida.

    PubMed

    Brown, Sarah A E; Simpson, André J; Simpson, Myrna J

    2008-04-01

    The earthworm Eisenia fetida is frequently used in ecotoxicological studies; however, it has not yet been investigated using proton nuclear magnetic resonance ((1)H NMR) metabolic profiling methods. The present study investigates the impact of depuration time, sample homogenization, and different extraction solvents on the quality and reproducibility of the (1)H NMR spectra of E. fetida with the goal of determining whether this species is suitable for future metabonomic studies. A depuration time of 96 h, followed by intact lyophilization before homogenization and extraction into a deuterium oxide (D(2)O)-based phosphate buffer, was found to produce extracts with excellent (1)H NMR reproducibility. The D(2)O buffer extracted the largest quantity of the widest variety of earthworm metabolites, which is consistent with the results from other studies using different earthworm species. Nuclear magnetic resonance assignments of the major metabolites in the D(2)O-based buffer also were performed and found to be similar to those for other earthworm species, such as Eisenia veneta, but also to have characteristic attributes in E. fetida. The major metabolites identified include amino acids (alanine, arginine, glutamic acid, glutamine, glycine, leucine, lysine, phenylalanine, serine, tyrosine, and valine), two sugars (glucose and maltose), the sugar alcohol mannitol, and the polyalcohol inositol. Two other earthworm species (Lumbricus rubellus and Lumbricus terrestris) also were examined using protocols developed for E. fetida, and of the three species, the (1)H NMR spectra of E. fetida had the least variation, indicating this species is well-suited for future metabolomic-based ecotoxicity studies. PMID:18333692

  20. A Three Parameter Model for Planning, Monitoring and Evaluating Human Services Field Experience. EDIC Monograph.

    ERIC Educational Resources Information Center

    Feringer, F. Richard; Jacobs, Edward

    A model for planning, monitoring, and evaluating human service internships and field experiences is described. The model is organized around work roles and can easily be adopted for general job evaluation beyond intern placements. Since the curriculum should contain the generalists' skills plus specialized skills representative of defined job…

  1. Evaluation of Structural Equation Mixture Models: Parameter Estimates and Correct Class Assignment

    ERIC Educational Resources Information Center

    Tueller, Stephen; Lubke, Gitta

    2010-01-01

    Structural equation mixture models (SEMMs) are latent class models that permit the estimation of a structural equation model within each class. Fitting SEMMs is illustrated using data from 1 wave of the Notre Dame Longitudinal Study of Aging. Based on the model used in the illustration, SEMM parameter estimation and correct class assignment are…

  2. Frequentist evaluation of intervals estimated for a binomial parameter and for the ratio of Poisson means

    NASA Astrophysics Data System (ADS)

    Cousins, Robert D.; Hymes, Kathryn E.; Tucker, Jordan

    2010-01-01

    Confidence intervals for a binomial parameter or for the ratio of Poisson means are commonly desired in high energy physics (HEP) applications such as measuring a detection efficiency or branching ratio. Due to the discreteness of the data, in both of these problems the frequentist coverage probability unfortunately depends on the unknown parameter. Trade-offs among desiderata have led to numerous sets of intervals in the statistics literature, while in HEP one typically encounters only the classic intervals of Clopper-Pearson (central intervals with no undercoverage but substantial over-coverage) or a few approximate methods which perform rather poorly. If strict coverage is relaxed, some sort of averaging is needed to compare intervals. In most of the statistics literature, this averaging is over different values of the unknown parameter, which is conceptually problematic from the frequentist point of view in which the unknown parameter is typically fixed. In contrast, we perform an (unconditional) average over observed data in the ratio-of-Poisson-means problem. If strict conditional coverage is desired, we recommend Clopper-Pearson intervals and intervals from inverting the likelihood ratio test (for central and non-central intervals, respectively). Lancaster's mid- P modification to either provides excellent unconditional average coverage in the ratio-of-Poisson-means problem.

  3. Evaluation in medical education: A topical review of target parameters, data collection tools and confounding factors

    PubMed Central

    Schiekirka, Sarah; Feufel, Markus A.; Herrmann-Lingen, Christoph; Raupach, Tobias

    2015-01-01

    Background and objective: Evaluation is an integral part of education in German medical schools. According to the quality standards set by the German Society for Evaluation, evaluation tools must provide an accurate and fair appraisal of teaching quality. Thus, data collection tools must be highly reliable and valid. This review summarises the current literature on evaluation of medical education with regard to the possible dimensions of teaching quality, the psychometric properties of survey instruments and potential confounding factors. Methods: We searched Pubmed, PsycINFO and PSYNDEX for literature on evaluation in medical education and included studies published up until June 30, 2011 as well as articles identified in the “grey literature”. Results are presented as a narrative review. Results: We identified four dimensions of teaching quality: structure, process, teacher characteristics, and outcome. Student ratings are predominantly used to address the first three dimensions, and a number of reliable tools are available for this purpose. However, potential confounders of student ratings pose a threat to the validity of these instruments. Outcome is usually operationalised in terms of student performance on examinations, but methodological problems may limit the usability of these data for evaluation purposes. In addition, not all examinations at German medical schools meet current quality standards. Conclusion: The choice of tools for evaluating medical education should be guided by the dimension that is targeted by the evaluation. Likewise, evaluation results can only be interpreted within the context of the construct addressed by the data collection tool that was used as well as its specific confounding factors. PMID:26421003

  4. Förster resonance energy transfer, absorption and emission spectra in multichromophoric systems. III. Exact stochastic path integral evaluation

    SciTech Connect

    Moix, Jeremy M.; Ma, Jian; Cao, Jianshu

    2015-03-07

    A numerically exact path integral treatment of the absorption and emission spectra of open quantum systems is presented that requires only the straightforward solution of a stochastic differential equation. The approach converges rapidly enabling the calculation of spectra of large excitonic systems across the complete range of system parameters and for arbitrary bath spectral densities. With the numerically exact absorption and emission operators, one can also immediately compute energy transfer rates using the multi-chromophoric Förster resonant energy transfer formalism. Benchmark calculations on the emission spectra of two level systems are presented demonstrating the efficacy of the stochastic approach. This is followed by calculations of the energy transfer rates between two weakly coupled dimer systems as a function of temperature and system-bath coupling strength. It is shown that the recently developed hybrid cumulant expansion (see Paper II) is the only perturbative method capable of generating uniformly reliable energy transfer rates and emission spectra across a broad range of system parameters.

  5. Change in resonance parameters of a linear molecule as it bends: Evidence in electron-impact vibrational transitions of hot COS and CO2 molecules*

    NASA Astrophysics Data System (ADS)

    Hoshino, Masamitsu; Ishijima, Yohei; Kato, Hidetoshi; Mogi, Daisuke; Takahashi, Yoshinao; Fukae, Katsuya; Limão-Vieira, Paulo; Tanaka, Hiroshi; Shimamura, Isao

    2016-04-01

    Inelastic and superelastic electron-impact vibrational excitation functions of hot carbonyl sulphide COS (and hot CO2) are measured for electron energies from 0.5 to 3.0 eV (1.5 to 6.0 eV) and at a scattering angle of 90°. Based on the vibrational populations and the principle of detailed balance, these excitation functions are decomposed into contributions from state-to-state vibrational transitions involving up to the second bending overtone (030) in the electronically ground state. Both the 2Π resonance for COS around 1.2 eV and the 2Πu resonance for CO2 around 3.8 eV are shifted to lower energies as the initial vibrational state is excited in the bending mode. The width of the resonance hump for COS changes only little as the molecule bends, whereas that of the overall boomerang resonance for CO2 becomes narrower. The angular distribution of the electrons resonantly scattered by hot COS and hot CO2 is also measured. The different shapes depending on the vibrational transitions and gas temperatures are discussed in terms of the symmetry of the vibrational wave functions. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.

  6. An Evaluation of the Permittivity of Two Different Rock Types Using Microwave Resonator and Waveguide Cutoff Principles

    NASA Astrophysics Data System (ADS)

    Olkkonen, Martta-Kaisa; Eskelinen, Pekka; Huuskonen-Snicker, Eeva; Pellinen, Terhi; Olmos Martinez, Pablo

    2015-01-01

    Methods of measuring the complex permittivity of different rock types are demonstrated in the frequency range from 6 GHz to 17 GHz. The used methods are based on the cylindrical resonator and waveguide cutoff frequency principles. This study is part of a larger research project that aims to characterize the electrical properties of asphalt for road surveying purposes. The studied rock types are metavolcanic rock with intermediate composition and pegmatite. The permittivity values gained with the resonator method are 6.2 for the metavolcanic rock and 4.5 for the pegmatite rock type, whereas the imaginary parts are 0.04 and 0.02. The permittivity values gained with the cutoff frequency method are 6.17 and 4.76 respectively. A reference measurement was made only for the metavolcanic rock in a transmission configuration with two antennas and the permittivity result was 6.21. The three different methods provide consistent permittivity values and are suitable for reliable permittivity evaluation.

  7. Biomechanical evaluation of oversized drilling technique on primary implant stability measured by insertion torque and resonance frequency analysis

    PubMed Central

    Santamaría-Arrieta, Gorka; Brizuela-Velasco, Aritza; Fernández-González, Felipe J.; Chávarri-Prado, David; Chento-Valiente, Yelko; Solaberrieta, Eneko; Diéguez-Pereira, Markel; Yurrebaso-Asúa, Jaime

    2016-01-01

    Background This study evaluated the influence of implant site preparation depth on primary stability measured by insertion torque and resonance frequency analysis (RFA). Material and Methods Thirty-two implant sites were prepared in eight veal rib blocks. Sixteen sites were prepared using the conventional drilling sequence recommended by the manufacturer to a working depth of 10mm. The remaining 16 sites were prepared using an oversize drilling technique (overpreparation) to a working depth of 12mm. Bone density was determined using cone beam computerized tomography (CBCT). The implants were placed and primary stability was measured by two methods: insertion torque (Ncm), and RFA (implant stability quotient [ISQ]). Results The highest torque values were achieved by the conventional drilling technique (10mm). The ANOVA test confirmed that there was a significant correlation between torque and drilling depth (p<0.05). However, no statistically significant differences were obtained between ISQ values at 10 or 12 mm drilling depths (p>0.05) at either measurement direction (cortical and medullar). No statistical relation between torque and ISQ values was identified, or between bone density and primary stability (p >0.05). Conclusions Vertical overpreparation of the implant bed will obtain lower insertion torque values, but does not produce statistically significant differences in ISQ values. Key words:Implant stability quotient, overdrilling, primary stability, resonance frequency analysis, torque. PMID:27398182

  8. A Method for Evaluating Electron Transport Parameters on a Pulsed Townsend Experiment

    SciTech Connect

    Ridenti, M. A.; Pascholati, P. R.; Vivaldini, T. C.; Lima, I. B.

    2010-05-21

    In this work, we present a physical model that links fundamental theory of electron kinetics on weakly ionized gases to direct measurements of induced pulsed signals in a Resistive Plate Chamber. It is also presented preliminary measurements of electron transport parameters in nitrogen obtained for reduced electric fields ranging from 129 Td up to 216 Td. These parameters were indirectly determined by fitting the proposed model to the time dependent pulse current induced on the parallel plate chamber electrodes by an electron avalanche triggered near the cathode by a N{sub 2} laser pulse. Experimental results are compared with previous measurements, Monte Carlo simulation results from Magboltz and results from classical two-term expansion Boltzmann equation solution from Bolsig+.

  9. Effects of Cream Containing Ficus carica L. Fruit Extract on Skin Parameters: In vivo Evaluation

    PubMed Central

    Khan, H.; Akhtar, N.; Ali, A.

    2014-01-01

    This study was aimed to investigate the effects of cream containing Ficus carica L. fruit (Fig) extract on various skin parameters such as skin melanin, erythema, moisture content, trans-epidermal water loss and sebum. For this purpose, formulation with 4% concentrated extract of F. carica fruit and base without extract were developed. Base served as a control. Both base and formulation were applied to the cheeks of human volunteers for 8 weeks to investigate the effects on different skin parameters using non-invasive bioengineering instruments. Formulation decreased the skin melanin, trans-epidermal water loss and skin sebum significantly. Formulation increased the skin hydration significantly and insignificant effects on skin erythema. We concluded that a stable topical cream (w/o emulsion) containing F. carica fruit extract have effects on skin melanin, trans-epidermal loss, hydration values and sebum content and possibly could be used against for hyper pigmentation, acne, freckles and wrinkle. PMID:25593393

  10. Clinical evaluation of nares-vocal cord distance and its correlation with various external body parameters

    PubMed Central

    Sareen, Bhuwan; Kapur, Anu; Gupta, Sanjay Kumar; Sareen, Parul Bansal; Nischal, Hitesh

    2015-01-01

    Background and Aims: The optimal visualisation of vocal cords during fibreoptic intubation may be utilised for the nares-vocal cord distance (NVD) estimation. The present study was conducted to measure NVD and to correlate with various external body parameters. Methods: This study was conducted on 50 males and 50 females. We measured NVD and analysed its relationship with height, nares to tragus of ear distance (NED), nares to angle of mandible distance (NMD), sternal length (SL), thyro-mental distance (TMD), sterno-mental distance (SMD) and arm span (AS). Results: The mean NVD of the males was 18.5 ± 1.5 cm, and that of the females was 15.9 ± 1.1 cm. The relationship between the NVD and body height (males P = 0.001, r = 0.463, females P = 0.000, r = 0.555), SL (males P = 0.000, r = 0.463, females P < 0.000, r = 0.801) or AS (males P = 0.000, r = 0.561, females P = 0.000, r = 0.499) showed a significant correlation but NED, NMD, TMD, SMD did not. After combining male and female groups, (n = 100), the correlation of NVD with external body parameters is as follows SL (r = 0.887), height (r = 0.791), AS (r = 0.769), weight (r = 0.531), SMD (r = 0.466), NED (r = 0.459), NMD (r = 0.391), TMD (r = 0.379). Conclusion: The relationship of NVD to external body parameters had strong correlation in all parameters in the combined group; whereas when gender was taken into consideration NVD correlated significantly only with SL, height and AS. PMID:25937646

  11. Using three-parameter models to evaluate the Good Cents(TM) program in College Station, Texas

    NASA Astrophysics Data System (ADS)

    Ellingson, Lee Allen

    Integrated Resource Planning (IRP) refers to a comprehensive strategy adopted by many utility companies that addresses both the supply and demand of energy. Activities that focus on the demand for energy are called Demand Side Management (DSM). This study is an evaluation of a DSM program sponsored by College Station, Texas, called the Good CentsspTM Program. The Good Cents Program is designed to encourage builders to build more energy-efficient homes. One difficulty with evaluating this type of program is that energy use not related to outdoor air temperature introduces a large amount of unexplained variability into total energy use. This study uses a statistical method that separates energy related to outdoor temperature from energy not related to outdoor temperature. Three-parameter models have proven to be very useful in modeling residential energy use. This study uses parameter estimates of three-parameter models to compare a treatment group of Good Cents houses to a control group of non-Good Cents houses. Parameters used are cooling slope, heating slope, and Normalized Annual Consumption (NAC). In addition, independent variables are regressed against the cooling and heating slopes to determine which variables correlate to energy efficiency.

  12. Redistribution of renal blood flow after SWL evaluated by Gd-DTPA-enhanced magnetic resonance imaging.

    PubMed

    Mostafavi, M R; Chavez, D R; Cannillo, J; Saltzman, B; Prasad, P V

    1998-02-01

    Extracorporeal shockwave lithotripsy (SWL) is currently accepted as an effective noninvasive treatment for a wide variety of urinary tract calculi. However, the bioeffects of high-energy shockwaves on renal parenchyma have yet to be fully elucidated. The objective of this study was to measure the acute changes in regional renal hemodynamics associated with SWL utilizing dynamic gadolinium-DTPA-enhanced magnetic resonance imaging (MRI). Seven patients who underwent SWL for renal calculi had an MRI study within 4 hours after the treatment. To assess renal hemodynamics, a bolus of Gd DTPA (0.03 mmol/kg) was administered, and dynamic contrast enhanced images was obtained. Regions of interest (ROI) were defined over the cortex and medulla to obtain signal intensity-v-time curves. The contralateral kidney in each patient was used as the control. The initial slope of the contrast-enhanced signal intensity-v-time curve was used as a measure of the perfusion index (PI). In six patients, perfusion imaging showed a consistent trend of decreased cortical flow (29+/-8%) and a concomitant increase in medullary flow (34+/-14%) in the region of the kidney that was targeted with SWL in six patients (86%). This study shows that renal hemodynamics are modified by SWL. We hypothesize that this change represents a shunting of flow from cortex to medulla in an attempt to prevent ischemia of the medulla.

  13. Dosimetric evaluation for exposure of patient to a z-gradient coil in magnetic resonance imaging

    SciTech Connect

    Lu Mai; Ueno, Shoogo

    2011-04-01

    In magnetic resonance imaging, time-varied gradient magnetic fields may stimulate nerves and muscles by inducing electric fields and currents in patients, which may potentially cause health problems. In this paper, a realistic z-gradient coil was numerically designed and the exposure level in a 3D real human man model was calculated by using the impedance method. It was found that the z-gradient coil produces a magnetic flux density (B-field) with two regions of good homogeneity along the coil length, separated by a very weak B-field in the middle of the coil. The spatially averaged B-field is 281 times greater than that of the International Commission on Non-Ionizing Radiation Protection's (ICNIRP) reference level. The 1-cm{sup 2}-averaged induced current density in the central nervous system is 87 times greater than that of the ICNIRP's basic restriction. The maximum current density in all of the body tissues is above the nerve stimulation threshold.

  14. Dosimetric evaluation for exposure of patient to a z-gradient coil in magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Lu, Mai; Ueno, Shoogo

    2011-04-01

    In magnetic resonance imaging, time-varied gradient magnetic fields may stimulate nerves and muscles by inducing electric fields and currents in patients, which may potentially cause health problems. In this paper, a realistic z-gradient coil was numerically designed and the exposure level in a 3D real human man model was calculated by using the impedance method. It was found that the z-gradient coil produces a magnetic flux density (B-field) with two regions of good homogeneity along the coil length, separated by a very weak B-field in the middle of the coil. The spatially averaged B-field is 281 times greater than that of the International Commission on Non-Ionizing Radiation Protection's (ICNIRP) reference level. The 1-cm2-averaged induced current density in the central nervous system is 87 times greater than that of the ICNIRP's basic restriction. The maximum current density in all of the body tissues is above the nerve stimulation threshold.

  15. Evaluation of Gastric Volumes: Comparison of 3-D Ultrasound and Magnetic Resonance Imaging.

    PubMed

    Buisman, Wijnand J; Mauritz, Femke A; Westerhuis, Wouter E; Gilja, Odd Helge; van der Zee, David C; van Herwaarden-Lindeboom, Maud Y A

    2016-07-01

    To investigate gastric accommodation, accurate measurements of gastric volumes are necessary. An excellent technique to measure gastric volumes is dynamic magnetic resonance imaging (MRI). Unfortunately, dynamic MRI is expensive and not always available. A new 3-D ultrasound (US) method using a matrix transducer was developed to measure gastric volumes. In this prospective study, 14 healthy volunteers underwent a dynamic MRI and a 3-D US. Gastric volumes were calculated with intra-gastric liquid content and total gastric volume. Mean postprandial liquid gastric content was 397 ± 96.5 mL. Mean volume difference was 1.0 mL with limits of agreement of -8.9 to 10.9 mL. When gastric air was taken into account, mean total gastric volume was 540 ± 115.4 mL SD. Mean volume difference was 2.3 mL with limits of agreement of -21.1 to 26.4 mL. The matrix 3-D US showed excellent agreement with dynamic MRI. Therefore matrix 3-D US is a reliable alternative to measure gastric volumes. PMID:27067418

  16. Evaluation of a rabbit rectal VX2 carcinoma model using computed tomography and magnetic resonance imaging

    PubMed Central

    Liang, Xin-Mei; Tang, Guang-Yu; Cheng, Ying-Sheng; Zhou, Bi

    2009-01-01

    AIM: To establish a rabbit rectal VX2 carcinoma model for the study of rectal carcinoma. METHODS: A suspension of VX2 cells was injected into the rectum wall under the guidance of X-ray fluoroscopy. Computed tomography (CT) and magnetic resonance imaging (MRI) were used to observe tumor growth and metastasis at different phases. Pathological changes and spontaneous survival time of the rabbits were recorded. RESULTS: Two weeks after VX2 cell implantation, the tumor diameter ranged 4.1-5.8 mm and the success implantation rate was 81.8%. CT scanning showed low-density foci of the tumor in the rectum wall, while enhanced CT scanning demonstrated asymmetrical intensification in tumor foci. MRI scanning showed a low signal of the tumor on T1-weighted imaging and a high signal of the tumor on T2-weighted imaging. Both types of signals were intensified with enhanced MRI. Metastases to the liver and lung could be observed 6 wk after VX2 cell implantation, and a large area of necrosis appeared in the primary tumor. The spontaneous survival time of rabbits with cachexia and multiple organ failure was about 7 wk after VX2 cell implantation. CONCLUSION: The rabbit rectal VX2 carcinoma model we established has a high stability, and can be used in the study of rectal carcinoma. PMID:19418587

  17. Evaluation of nonlinear impact resonance spectroscopy method for detecting delayed ettringite formation

    NASA Astrophysics Data System (ADS)

    Rashidi, M. M. N.; Paul, A.; Kim, J.-Y.; Jacobs, L. J.; Kurtis, K. E.

    2015-03-01

    The use of the Nonlinear Impact Resonance Acoustic Spectroscopy (NIRAS) method to monitor the evolution of damage due to delayed ettringite formation (DEF) is examined. In practice, the temperature of concrete during casting of precast concrete members or massive concrete structures may reach higher than 70°C which can provide suitable conditions for damage to occur due to DEF, particularly in concrete which is subsequently exposed to wet environments. While expansion - often in excess of 1% - is characteristic of DEF, the evolution of damage begins with microcracking. Unfortunately, there is no standard to test the susceptibility of materials or material combinations to DEF. On the other hand, NIRAS shows great sensitivity to the detection of microcracks and has been successfully applied to concrete to detect thermal and alkali silica reaction in concrete. In this preliminary research, the NIRAS method is used to discriminate among mortar samples which are relatively undamaged and those in the early stages of DEF. The results show that NIRAS could be a reliable and robust method in the detection of microcracks due to DEF.

  18. Synthesis and in vivo magnetic resonance imaging evaluation of biocompatible branched copolymer nanocontrast agents

    PubMed Central

    Jackson, Alexander W; Chandrasekharan, Prashant; Shi, Jian; Rannard, Steven P; Liu, Quan; Yang, Chang-Tong; He, Tao

    2015-01-01

    Branched copolymer nanoparticles (Dh =20–35 nm) possessing 1,4,7, 10-tetraazacyclododecane-N,N′,N″,N‴-tetraacetic acid macrocycles within their cores have been synthesized and applied as magnetic resonance imaging (MRI) nanosized contrast agents in vivo. These nanoparticles have been generated from novel functional monomers via reversible addition–fragmentation chain transfer polymerization. The process is very robust and synthetically straightforward. Chelation with gadolinium and preliminary in vivo experiments have demonstrated promising characteristics as MRI contrast agents with prolonged blood retention time, good biocompatibility, and an intravascular distribution. The ability of these nanoparticles to perfuse and passively target tumor cells through the enhanced permeability and retention effect is also demonstrated. These novel highly functional nanoparticle platforms have succinimidyl ester-activated benzoate functionalities within their corona, which make them suitable for future peptide conjugation and subsequent active cell-targeted MRI or the conjugation of fluorophores for bimodal imaging. We have also demonstrated that these branched copolymer nanoparticles are able to noncovalently encapsulate hydrophobic guest molecules, which could allow simultaneous bioimaging and drug delivery. PMID:26425088

  19. Evaluation of congenital heart disease by cine magnetic resonance imaging (MRI)

    SciTech Connect

    Feiglin, D.H.I.; Moodie, D.S.; O'Donnell, J.K.; Go, R.T.; Sterba, R.; MacIntyre, W.J.

    1985-05-01

    The authors studied 11 adult patients (pts) with atrial septal defect (ASD) and 4 adult pts with ventricular septal defect (VSD) using cine magnetic resonance. All studies were performed using a .6T superconducting magnet with ECG gating and electronic axial rotation when appropriate. Repeated multislice image with no change in physiologic delay of the spin echo pulse sequence, but varying the time by offsetting one slice at each imaging stage allowed for an N x N collection of data where N is the number of slices in one collection set and is equal to the number of sets collected. Algebraic manipulation of the T1 weighted images (TE=30mSec TR

  20. Magnetic Resonance Imaging as an Adjunct to Ultrasound in Evaluating Cesarean Scar Ectopic Pregnancy

    PubMed Central

    Wu, Rebecca; Klein, Michelle A.; Mahboob, Sabrina; Gupta, Mala; Katz, Douglas S.

    2013-01-01

    Cesarean scar pregnancies (CSPs) are a relatively rare form of ectopic pregnancy in which the embryo is implanted within the fibrous scar of a previous cesarean section. A greater number of cases of CSPs are currently being reported as the rates of cesarean section are increasing globally and as detection of scar pregnancy has improved with use of transvaginal ultrasound (TVUS) with color Doppler imaging. Delayed diagnosis and management of this potentially life-threatening condition may result in complications, predominantly uterine rupture and hemorrhage with significant potential maternal morbidity. Diagnosis of a cesarean scar pregnancy (CSP) requires a high index of clinical suspicion, as up to 40% of patients may be asymptomatic. TVUS has a reported sensitivity of 84.6% and has become the imaging examination of choice for diagnosis of a CSP. Magnetic resonance imaging (MRI) has been used in a small number of patients as an adjunct to TVUS. In the present report, MRI is highlighted as a problem-solving tool capable of more precisely identifying the relationship of a CSP to adjacent structures, thereby providing additional information critical to directing appropriate patient management and therapy. PMID:23814688

  1. Comparison of Intravoxel Incoherent Motion Parameters across MR Imagers and Field Strengths: Evaluation in Upper Abdominal Organs.

    PubMed

    Barbieri, Sebastiano; Donati, Olivio F; Froehlich, Johannes M; Thoeny, Harriet C

    2016-06-01

    Purpose To determine the reproducibility of intravoxel incoherent motion (IVIM) parameters measured in upper abdominal organs with magnetic resonance (MR) imagers from different vendors and with different field strengths. Materials and Methods This prospective study was approved by the independent ethics committees of Kanton Bern and Kanton Zurich, and signed informed consent was obtained from all participants. Abdominal diffusion-weighted images in 10 healthy men (mean age, 37 years ± 8 [standard deviation]) were acquired by using 1.5- and 3.0-T MR imagers from three different vendors. Two readers independently delineated regions of interest that were used to measure IVIM parameters (diffusion coefficient [Dt], perfusion fraction [Fp], and pseudodiffusion coefficient [Dp]) in the left and right lobes of the liver, and in the pancreas, spleen, renal cortex, and renal medulla. Measurement reproducibility between readers was assessed with intraclass correlation coefficients (ICCs). Variability across MR imagers was analyzed by using between- and within-subject coefficients of variation (CVs) and analysis of variance (ANOVA). Results Between-reader reproducibility was high for Dt (ICC, 94.6%), intermediate for Fp (ICC, 81.7%), and low for Dp (ICC, 69.5%). Between- and within-subject CVs of Dt were relatively high (>20%) in the left lobe of the liver and relatively low (<10%) in the renal cortex and renal medulla. CVs generally exceeded 15% for Fp values and 20% for Dp. ANOVA indicated significant differences (P < .05) between MR imagers. Conclusion IVIM parameters in the upper abdomen may differ substantially across MR imagers. (©) RSNA, 2015 Online supplemental material is available for this article. PMID:26678455

  2. [A case of pentalogy of Fallot with numerous collaterals evaluated by magnetic resonance imaging: a report of an adult case].

    PubMed

    Fukuzawa, S; Kagaya, A; Kuramoto, M; Kudo, K; Katagiri, M; Ozawa, S; Momata, S; Watanabe, S; Masuda, Y; Inagaki, Y

    1985-12-01

    In this report, the diagnostic value of magnetic resonance imaging (MRI) was compared with that of two-dimensional echocardiography, computed tomography and cardiac catheterization in a patient with pentalogy of Fallot who survived to her fortieth year. The advantages and disadvantages of MRI in diagnosing the present case were as follows: The cardiovascular system, with the exception of atrial septal defect, was evaluated precisely. Collateral vessels were detected using MRI, but impossible with other non-invasive methods. MRI was particularly suitable for imaging the cardiovascular system because of the high contrast between the lower intensity signal of the blood and higher intensity signal of the myocardium and blood vessel walls. Using MRI, data acquisition time was 1.5 min per section. Gated MRI required more time for data acquisition. However, various oblique tomographic projections and very clear static images could be obtained using gated MRI. MRI should be one of the best diagnostic techniques for diagnosing congenital heart disease.

  3. Do biometric parameters of the hand differentiate schizophrenia from other psychiatric disorders? A comparative evaluation using three mental health modules.

    PubMed

    Zvi Shamir, Eyal; Levy, Anat; Morris Cassan, Stanley; Lifshitz, Tova; Shefler, Gaby; Tarrasch, Ricardo

    2015-08-30

    The link between schizophrenia and anomalies in the distal upper limb is well documented. Preliminary studies have identified a number of biometric parameters of the hand by which schizophrenics can be distinguished from matched controls. The current study seeks to determine whether patients with schizophrenia can be singled out from a disparate group of other mental disorders by using the same parameters. We studied three groups, totaling 134 men: 51 diagnosed with schizophrenia, 29 with anxiety and mood disorders, and 54 comprising a control group. Seven parameters were studied: the proximal interphalangeal joint, the eponychia of the middle and ring digits, two dermatoglyphic features, and two constitutional factors. Examiners evaluated the parameters based on photographs and prints. An initial Mann Whitney comparison showed no significant difference between the control group and those identified with anxiety and mood disorders. We therefore accounted for them as a single group. In a discriminant analysis, an overall accuracy of 78.4% was established with a sensitivity of 80.4% (schizophrenics identified correctly) and a specificity of 77.1% (controls identified correctly). These results suggest that the biometric parameters employed may be useful in identifying patients with schizophrenia from a disparate group of other mental disorders.

  4. Evaluation of Effecting Parameters on Optimum Arrangement of Urban Land Uses and Assessment of Their Compatibility Using Adjacency Matrix

    NASA Astrophysics Data System (ADS)

    Vaezi, S.; Mesgari, M. S.; Kaviary, F.

    2015-12-01

    Todays, stability of human life is threatened by a set of parameters. So sustainable urban development theory is introduced after the stability theory to protect the urban environment. In recent years, sustainable urban development gains a lot of attraction by different sciences and totally becomes a final target for urban development planners and managers to use resources properly and to establish a balanced relationship among human, community, and nature. Proper distribution of services for decreasing spatial inequalities, promoting the quality of living environment, and approaching an urban stability requires an analytical understanding of the present situation. Understanding the present situation is the first step for making a decision and planning effectively. This paper evaluates effective parameters affecting proper arrangement of land-uses using a descriptive-analytical method, to develop a conceptual framework for understanding of the present situation of urban land-uses, based on the assessment of their compatibility. This study considers not only the local parameters, but also spatial parameters are included in this study. The results indicate that land-uses in the zone considered here are not distributed properly. Considering mentioned parameters and distributing service land-uses effectively cause the better use of these land-uses.

  5. Collinear Cluster Tripartition as a Neutron Source--Evaluation of the Setup Parameters

    SciTech Connect

    Kamanin, D. V.; Kuznetsova, E. A.; Aleksandrov, A. A.; Aleksandrova, I. A.; Borzakov, S. B.; Chelnokov, M. L.; Pham Minh, D.; Kondratyev, N. A.; Kopach, Yu. N.; Panteleev, Ts.; Penionzhkevich, Yu. E.; Svirikhin, A. I.; Sokol, E. A.; Testov, D. A.; Zhuchko, V. E.; Yeremin, A. V.; Pyatkov, Yu. V.; Jacobs, N.; Ryabov, Yu. V.

    2010-04-30

    Forthcoming experiments aimed at studying the mechanism of collinear cluster tripartition are planning to be performed with the new facility. Charged products will be registered with the double arm time-of-flight spectrometer composed of mosaics of PIN -diodes and MCP (micro channel plates) based timing detectors. Several tens of {sup 3}He-filled counters will be gathered round the {sup 252}Cf source. In order to choose an optimal configuration of the neutron detector and other parameters of the experiment special modeling has performed using both 'neutron barrel' and known MCNP code. The first test run of the new facility is in progress also its 'neutron skin' in under construction.

  6. Intermediate-term evaluation of a pratical chelation protocol based on stratification of thalassemic patients by serum ferritin and magnetic resonance imaging cardiac t2*.

    PubMed

    Ha, Shau-Yin; Mok, Amanda Sio-Peng; Chu, Winnie Chiu-Wing; Rasalkar, Darshana Dattatray; Cheuk, Daniel Ka-Leung; Chiang, Alan Kwok-Shing; Ho, Marco Hok-Kung; Chan, Godfrey Chi-Fung

    2011-01-01

    A standardized chelation protocol was applied by stratifying transfusion-dependent thalassemic patients into three groups, namely well chelated group (A), inadequately chelated group without (B) or with (C) risk of cardiac complications based on serum ferritin (SF) levels and magnetic resonance imaging (MRI) cardiac T2* measurements. Group A patients were advised to continue with deferoxamine (DFO) (Regimen Ic). Group B patients were given options of either intensification of DFO alone (Regimen Ii), deferiprone (L1) alone (Regimen II) or combined therapy with L1 and DFO (Regimen III). Group C patients were advised to take either Regimen Ii or Regimen III. The 1-year result showed that the combined therapy (Regimen III) significantly reduced SF level, cardiac and liver iron in the groups of inadequately chelated patients. The same set of outcome parameters was repeated at 2.5 years of treatment so as to evaluate the intermediate-term effects of this risk stratified chelation protocol. The number of patients with cardiac T2* <20 ms decreased from 34 (60%) at baseline to 17 (30%) of the whole cohort of 57 patients at the end of the study. There were further improvements in SF, cardiac and liver T2* in Group C patients. Significant improvement in left ventricular ejection fraction (LVEF) was demonstrated after 2.5 years of the combined therapy group in which the change was not initially apparent after the first year of assessment.

  7. Evaluating the Aging of Multiple Emulsions Using Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry.

    PubMed

    Tsuda, Yukihiro; Uchimura, Tomohiro

    2016-01-01

    Resonance-enhanced multiphoton ionization time-of-flight mass spectrometry was applied to measurements of multiple emulsions with no pretreatment; a method for the quantitative evaluation of aging was proposed. We prepared water-in-oil-in-water (W/O/W) multiple emulsions containing toluene and m-phenylenediamine. The samples were measured immediately following both preparation and after having been stirred for 24 h. Time profiles of the peak areas for each analyte species were obtained, and several intense spikes for toluene could be detected from each sample after stirring, which suggests that the concentration of toluene in the middle phase had increased during stirring. On the other hand, in the case of a W/O/W multiple emulsion containing phenol and m-phenylenediamine, spikes for m-phenylenediamine, rather than phenol, were detected after stirring. In the present study, the time-profile data were converted into a scatter plot in order to quantitatively evaluate the aging. As a result, the ratio of the plots where strong signal intensities of toluene were detected increased from 8.4% before stirring to 33.2% after stirring for 24 h. The present method could be a powerful tool for evaluating multiple emulsions, such as studies on the kinetics of the encapsulation and release of active ingredients. PMID:27396662

  8. Comparison of intravenous urography and magnetic resonance urography in preoperative evaluation of pelvi-ureteric junction obstruction in children

    PubMed Central

    Sharma, Alok; Sodhi, Kushaljit Singh; Saxena, Akshay Kumar; Bhatia, Anmol; Menon, Prema; Rao, Katragadda L. N.; Khandelwal, Niranjan

    2016-01-01

    Aims: To compare intravenous urography (IVU) and magnetic resonance urography (MRU) in the preoperative evaluation of pelvi-ureteric junction obstruction (PUJO) in children. Materials and Methods: A total of 35 children up to 10 years of age in whom unilateral or bilateral PUJO were suspected on ultrasonography were enrolled in this prospective study. All children underwent IVU and MRU, and the findings were compared. Results: Of the 70 kidneys evaluated, 14 (20%) were not visualized on IVU because of nonexcretion of contrast, whereas all the 70 (100%) kidneys were visualized on MRU. On IVU, nephrogram was not visualized in 66 (94.2%) of the 70 kidneys, whereas MRU showed prompt and homogeneous nephrogram in 68 (97.1%) of the 70 kidneys. No evidence of PUJO was seen in 31 (44.2%) kidneys on both IVU and MRU. IVU showed PUJO in 26 (37.1%) kidneys, whereas MRU showed it in 38 (54.2%) kidneys. MRU detected two duplex systems that were missed on IVU. A focal renal lesion and two incidental extra renal abnormalities were detected on MRU, which were not visualized on IVU. Conclusion: MRU is better than IVU, especially in case of poorly functioning kidneys which are not visualized on IVU. MRU also provides anatomic details of the ureter and vessels with better evaluation of renal parenchyma. It also has an additional advantage of detecting incidental extra renal abnormalities, if present. PMID:27695208

  9. Comparison of intravenous urography and magnetic resonance urography in preoperative evaluation of pelvi-ureteric junction obstruction in children

    PubMed Central

    Sharma, Alok; Sodhi, Kushaljit Singh; Saxena, Akshay Kumar; Bhatia, Anmol; Menon, Prema; Rao, Katragadda L. N.; Khandelwal, Niranjan

    2016-01-01

    Aims: To compare intravenous urography (IVU) and magnetic resonance urography (MRU) in the preoperative evaluation of pelvi-ureteric junction obstruction (PUJO) in children. Materials and Methods: A total of 35 children up to 10 years of age in whom unilateral or bilateral PUJO were suspected on ultrasonography were enrolled in this prospective study. All children underwent IVU and MRU, and the findings were compared. Results: Of the 70 kidneys evaluated, 14 (20%) were not visualized on IVU because of nonexcretion of contrast, whereas all the 70 (100%) kidneys were visualized on MRU. On IVU, nephrogram was not visualized in 66 (94.2%) of the 70 kidneys, whereas MRU showed prompt and homogeneous nephrogram in 68 (97.1%) of the 70 kidneys. No evidence of PUJO was seen in 31 (44.2%) kidneys on both IVU and MRU. IVU showed PUJO in 26 (37.1%) kidneys, whereas MRU showed it in 38 (54.2%) kidneys. MRU detected two duplex systems that were missed on IVU. A focal renal lesion and two incidental extra renal abnormalities were detected on MRU, which were not visualized on IVU. Conclusion: MRU is better than IVU, especially in case of poorly functioning kidneys which are not visualized on IVU. MRU also provides anatomic details of the ureter and vessels with better evaluation of renal parenchyma. It also has an additional advantage of detecting incidental extra renal abnormalities, if present.

  10. Quantitative evaluation of sonophoresis efficiency and its dependence on sonication parameters and particle size.

    PubMed

    Lee, Kun Loong; Zhou, Yufeng

    2015-03-01

    Transdermal drug delivery makes a critical contribution to medical practice and some advantages over conventional oral administration and hypodermic injection. Enhancement of percutaneous absorption or penetration of therapeutic agents (ie, drugs and macromolecules) by ultrasound, termed sonophoresis, has been applied and studied for decades. In this study, the penetration percentage through porcine ear skin specimens was determined quantitatively by measuring the fluorescence from nanoparticles of 60, 220, and 840 nm in size in a receptor chamber at different sonication parameters (ie, duty cycle, 20%-100%; acoustic intensity, 0.3-1.0 W/cm(2); duration, 7-30 minutes; and frequency, 1 MHz). In general, the sonophoresis efficiency increased with the acoustic intensity, duty cycle, and sonication duration but decreased with the particle size (mean ± SD, 62.6% ± 5.4% for 60-nm versus 11.9% ± 1.1% for 840-nm polystyrene nanospheres after 30 minutes of sonication at 0.5 W/cm(2) and a 100% duty cycle; P < .05). On scanning electron microscopy the pore size remained the same (≈100 μm), but more flakes were observed with the progress of sonication. In summary, sonophoresis efficiency is dependent on the ultrasound parameters and particle size. Sufficient sonication would lead to satisfactory penetration of even submicrometer objects through the pores. PMID:25715372

  11. Quantitative evaluation of susceptibility effects caused by dental materials in head magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Strocchi, S.; Ghielmi, M.; Basilico, F.; Macchi, A.; Novario, R.; Ferretti, R.; Binaghi, E.

    2016-03-01

    This work quantitatively evaluates the effects induced by susceptibility characteristics of materials commonly used in dental practice on the quality of head MR images in a clinical 1.5T device. The proposed evaluation procedure measures the image artifacts induced by susceptibility in MR images by providing an index consistent with the global degradation as perceived by the experts. Susceptibility artifacts were evaluated in a near-clinical setup, using a phantom with susceptibility and geometric characteristics similar to that of a human head. We tested different dentist materials, called PAL Keramit, Ti6Al4V-ELI, Keramit NP, ILOR F, Zirconia and used different clinical MR acquisition sequences, such as "classical" SE and fast, gradient, and diffusion sequences. The evaluation is designed as a matching process between reference and artifacts affected images recording the same scene. The extent of the degradation induced by susceptibility is then measured in terms of similarity with the corresponding reference image. The matching process involves a multimodal registration task and the use an adequate similarity index psychophysically validated, based on correlation coefficient. The proposed analyses are integrated within a computer-supported procedure that interactively guides the users in the different phases of the evaluation method. 2-Dimensional and 3-dimensional indexes are used for each material and each acquisition sequence. From these, we drew a ranking of the materials, averaging the results obtained. Zirconia and ILOR F appear to be the best choice from the susceptibility artefacts point of view, followed, in order, by PAL Keramit, Ti6Al4V-ELI and Keramit NP.

  12. Evaluation of the RF heating of a generic deep brain stimulator exposed in 1.5 T magnetic resonance scanners.

    PubMed

    Cabot, Eugenia; Lloyd, Tom; Christ, Andreas; Kainz, Wolfgang; Douglas, Mark; Stenzel, Gregg; Wedan, Steve; Kuster, Niels

    2013-02-01

    The radio frequency (RF) electromagnetic field of magnetic resonance (MR) scanners can result in significant tissue heating due to the RF coupling with the conducting parts of medical implants. The objective of this article is to evaluate the advantages and shortcomings of a new four-tier approach based on a combined numerical and experimental procedure, designed to demonstrate safety of implants during MR scans. To the authors' best knowledge, this is the first study analyzing this technique. The evaluation is performed for 1.5 T MR scanners using a generic model of a deep brain stimulator (DBS) with a straight lead and a helical lead. The results show that the approach is technically feasible and provides sound and conservative information about the potential heating of implants. We demonstrate that (1) applying optimized tools results in reasonable uncertainties for the overall evaluation; (2) each tier reduces the overestimation by several dB at the cost of more demanding evaluation steps; (3) the implant with the straight lead would cause local temperature increases larger than 18 °C at the RF exposure limit for the normal operating mode; (4) Tier 3 is not sufficient for the helical implant; and (5) Tier 4 might be too demanding to be performed for complex implants. We conclude with a suggestion for a procedure that follows the same concept but is between Tier 3 and 4. In addition, the evaluation of Tier 3 has shown consistency with current scan practice, namely, the resulting heat at the lead tip is less than 3.5 °C for the straight lead and 0.7 °C for the helix lead for scans at the current applied MR scan restrictions for deep brain stimulation at a head average SAR of 0.1 W/kg.

  13. Evaluation of Sedimentary and Terrain Parameters from MARDI Camera Imaging and Stereogrammetry at Gale Crater

    NASA Astrophysics Data System (ADS)

    Minitti, M. E.; Garvin, J. B.; Yingst, R. A.; Maki, J.

    2014-12-01

    The Mars Descent Imager (MARDI) provides mm-resolution imaging of an ~0.92 m by 0.64 cm patch of the Martian surface beneath the rover. Since Sol 310, MARDI has acquired images under twilight illumination to optimize image quality for quantitative sedimentology analysis. This imaging, carried out after each rover drive, permits systematic measurement of clast size distribution, inter-clast spacing distribution, and surface areal coverage. Sedimentological parameters derived from these observations include clast sorting (mean/var of size) and other characteristics related to transport mechanisms or in-place weathering. Measured surface parameters (e.g., clast sorting) can be correlated with surface units qualitatively defined (e.g., smooth, rocky, outcrop) in images obtained by HiRISE, MSL Mastcam and MSL Navcam. In addition, a preliminary longitudinal analysis has been conducted to examine possible source regions for the bulk of the gravels by correlating sedimentary parameters with distance from either Peace Valles or Mt. Sharp, with evidence of trends associated with inter-clast spacing. Sets of stereo MARDI images that allow the creation of high vertical precision (±2 mm) digital elevation models (DEMs) have also been acquired via two techniques. First, MARDI images taken at each step of comprehensive wheel imaging activities yield 5 MARDI images with ~50% overlap. Second, two MARDI sidewalk video imaging mode (SVIM) experiments yielded a continuous set of images during a rover drive with 75-82% overlap. DEMs created via either technique can be used to quantify terrain properties and measure clast cross-sectional shapes. The microtopographic properties of the Sol 651 surface (e.g., mean/sigma of local elevation and slopes) and its sub-cm texture as measured in the SVIM-derived DEM are consistent with the characterization of the terrain as smooth with few rocks >20 cm. Characterization of the Sol 691 surface as rockier than the Sol 651 surface is supported by a

  14. Evaluation of Periodontal Parameters in Patients with Early Stage Chronic Lymphocytic Leukemia

    PubMed Central

    Božić, Darko; Rinčić, Goran; Gaćina, Petar; Plančak, Darije

    2016-01-01

    Objective To assess periodontal conditions in patients with early stage CLL and to compare it with the periodontal status of age matched healthy controls and to analyze the relationship between periodontal and hematological parameters in CLL patients. Materials and Methods 60 subjects were examined: 30 patients with CLL Rai 0 (test group) and 30 age-matching healthy individuals (control group). The exclusion criteria were: presence of other systemic disease or condition (e.g. diabetes), history of treatment for periodontitis, use of antibiotics during the last 3 months, use of medications. Socio-demographic data were obtained by means of a questionnaire. Participants with at least 8 teeth underwent a full mouth examination assessing API, PBI, PPD, REC and CAL. Medical data for CLL patients were collected from the patients’ records, while hematological data were obtained from the hemogram. Results Difference between groups was statistically significant for age, number of teeth and frequency of dental checkups (p<0.05). Patients with CLL had significantly higher average values of periodontal indices (API 0.81±0.18; PBI 2.72±0.68; PPD 3.40±0.53; REC 1.95±0.87, CAL 4.37±0.80) compared to the control group (API 0.69±0.15; PBI 1.91±0.45; PPD 2.51±0.40; REC 0.99±0.54; CAL 3.00±0.58). The correlation coefficients between age and periodontal indices showed statistically significance between age and REC (r=0.357; p<0.01), and age and CAL (r=0.295; p<0.05). Age was not statistically significant covariate for CAL (F=2.205; p>0.05), only for REC (F=4.601; p<0.05). After the removal of the statistical effect of age, the difference in REC between CLL and control group remained statistically significant (F=19.732; p<0.01; eta2=0.287). Statistically significant association between periodontal and hematological parameters in CLL patients was not found (p>0.05). Conclusion The results of this study showed that patients with CLL had worse periodontal status compared to

  15. Evaluation of Periodontal Parameters in Patients with Early Stage Chronic Lymphocytic Leukemia

    PubMed Central

    Božić, Darko; Rinčić, Goran; Gaćina, Petar; Plančak, Darije

    2016-01-01

    Objective To assess periodontal conditions in patients with early stage CLL and to compare it with the periodontal status of age matched healthy controls and to analyze the relationship between periodontal and hematological parameters in CLL patients. Materials and Methods 60 subjects were examined: 30 patients with CLL Rai 0 (test group) and 30 age-matching healthy individuals (control group). The exclusion criteria were: presence of other systemic disease or condition (e.g. diabetes), history of treatment for periodontitis, use of antibiotics during the last 3 months, use of medications. Socio-demographic data were obtained by means of a questionnaire. Participants with at least 8 teeth underwent a full mouth examination assessing API, PBI, PPD, REC and CAL. Medical data for CLL patients were collected from the patients’ records, while hematological data were obtained from the hemogram. Results Difference between groups was statistically significant for age, number of teeth and frequency of dental checkups (p<0.05). Patients with CLL had significantly higher average values of periodontal indices (API 0.81±0.18; PBI 2.72±0.68; PPD 3.40±0.53; REC 1.95±0.87, CAL 4.37±0.80) compared to the control group (API 0.69±0.15; PBI 1.91±0.45; PPD 2.51±0.40; REC 0.99±0.54; CAL 3.00±0.58). The correlation coefficients between age and periodontal indices showed statistically significance between age and REC (r=0.357; p<0.01), and age and CAL (r=0.295; p<0.05). Age was not statistically significant covariate for CAL (F=2.205; p>0.05), only for REC (F=4.601; p<0.05). After the removal of the statistical effect of age, the difference in REC between CLL and control group remained statistically significant (F=19.732; p<0.01; eta2=0.287). Statistically significant association between periodontal and hematological parameters in CLL patients was not found (p>0.05). Conclusion The results of this study showed that patients with CLL had worse periodontal status compared to

  16. Evaluation of concepts and methods for extraction of flow parameters from laser transit anemometry data

    NASA Technical Reports Server (NTRS)

    Humphreys, W. M., Jr.; Hunter, W. W., Jr.

    1988-01-01

    A Monte-Carlo type simulation system was developed to test concepts and associated algorithms proposed by Mayo and Smart (1984) for the extraction of two-dimensional flow parameters from laser transit anemometry data sets. The Monte-Carlo LTA simulation program models a flow field as well as the sample volume geometry of the LTA system, thereby permitting simulation of two-dimensional data acquisition in a three-dimensional flow field. The results of these tests on the proposed processing concepts suggest that the instrument is capable of measuring mean velocities to less than +0.15 percent error and flow angles to less then +0.3 percent for turbulence intensities of up to 15.0 percent.

  17. Evaluation of parameters influencing the molecular delivery by biodegradable microsphere-mediated perforation using femtosecond laser

    NASA Astrophysics Data System (ADS)

    Mitsuhashi, Tatsuki; Terakawa, Mitsuhiro

    2014-01-01

    The parameters critically influencing the delivery rate on the biodegradable microsphere-mediated femtosecond (fs) laser perforation are investigated in detail with the aim of developing efficient molecular delivery. Cell membrane was perforated by the irradiation of weakly focused fs laser pulses to the spherical polylactic acid microspheres conjugated to the cell membrane. The delivery of fluorescein isothiocyanate-dextran and fluorescent silica particles to A431 cells is investigated in detail. The increase in the number of irradiated laser pulses had resulted in the increase of delivery rate. The delivery rate depends on the size and functionalization of fluorescent silica particles in which silica particles of 100 nm in diameter were able to be delivered into 20% of the irradiated cells, suggesting that the pore sizes are large enough for the delivery of therapeutic agents into cells. These findings contribute to the development of an efficient and safe phototherapy and drug delivery.

  18. Evaluation of third order nonlinear optical parameters of CdS/PVA nanocomposite

    SciTech Connect

    Sharma, Mamta; Tripathi, S. K. E-mail: surya-tr@yahoo.com

    2015-06-24

    CdS nanoparticles dispersed in PVA are prepared by Chemical method at room temperature. The nonlinear optical parameters such as nonlinear absorption (β), nonlinear refractive index (n{sub 2}) and nonlinear susceptibility (χ{sup 3}) are calculated for this sample by using Z-scan technique. CdS/PVA samples show the two photon absorption mechanism. The third order nonlinear susceptibility is calculated from n{sub 2} and β and is found to be of the order of 10{sup −7} – 10{sup −8} m{sup 2}/V{sup 2}. The larger value of third order nonlinear susceptibility is due to dielectric and quantum confinement effect.

  19. Selected immunological parameters in clinical evaluation of patients with atopic dermatitis

    PubMed Central

    Czarnecka-Operacz, Magdalena; Adamski, Zygmunt

    2016-01-01

    Introduction It has been suggested that soluble immune receptors (SIRs) such as sCD25 and sCD30 may serve as potential biomarkers in evaluation of atopic dermatitis (AD). Previous studies clearly indicated that serum levels of interleukin (IL)-13 and total IgE (tIgE) might be potentially useful in the evaluation of patents with AD. Aim To evaluate whether serum levels of sCD25 and sCD30 are suitable biomarkers of AD. Moreover, we have decided to estimate the usefulness of tIgE and IL-13 serum level determination in the evaluated population. Material and methods A group of 102 AD patients was investigated. Serum concentrations of sCD30, sCD25, IL-13 and tIgE were measured. The clinical phenotype of AD was classified as extrinsic (ADe) or intrinsic (ADi) based on the presence of IgE. Statistical analysis was performed to estimate correlations between obtained results and clinical features of the population such as AD phenotype, age, disease extent and severity. Results Extrinsic AD was diagnosed in 71% of patients, while ADi phenotype was observed in 29% of the investigated population. A negative correlation between serum levels of sCD25 and sCD30 and disease severity as well patients’ age was established. Serum levels of IL-13 did not reach the cut-off point set by the manufacturer. A positive correlation between serum levels of total IgE and disease severity and patients’ age was observed. Conclusions This paper shows that serum levels of sCD25 and sCD30 as well as tIgE are age dependent. Determination of serum levels of sCD25, sCD30 and IL-13 is not useful in everyday practice. PMID:27512357

  20. Evaluation of the effects of fructose on oxidative stress and inflammatory parameters in rat brain.

    PubMed

    Lopes, Abigail; Vilela, Thais Ceresér; Taschetto, Luciane; Vuolo, Franciele; Petronilho, Fabricia; Dal-Pizzol, Felipe; Streck, Emilio Luiz; Ferreira, Gustavo Costa; Schuck, Patrícia Fernanda

    2014-12-01

    Hereditary fructose intolerance is an autosomal recessive disorder characterized by the accumulation of fructose in tissues and biological fluids of patients. The disease results from a deficiency of aldolase B, responsible for metabolizing fructose in the liver, kidney, and small intestine. We investigated the effect of acute fructose administration on oxidative stress and neuroinflammatory parameters in the cerebral cortex of 30-day-old Wistar rats. Animals received subcutaneous injection of sodium chloride (0.9 %) (control group) or fructose solution (5 μmol/g) (fructose group). One hour later, the animals were euthanized and the cerebral cortex was isolated. Oxidative stress (levels of thiobarbituric acid-reactive substances (TBA-RS), carbonyl content, nitrate and nitrite levels, 2',7'-dihydrodichlorofluorescein (DCFH) oxidation, glutathione (GSH) levels, as well as the activities of catalase (CAT) and superoxide dismutase (SOD)) and neuroinflammatory parameters (TNF-α, IL-1β, and IL-6 levels and myeloperoxidase (MPO) activity) were investigated. Acute fructose administration increased levels of TBA-RS and carbonyl content, indicating lipid peroxidation and protein damage. Furthermore, SOD activity increased, whereas CAT activity was decreased. The levels of GSH, nitrate, and nitrite and DCFH oxidation were not altered by acute fructose administration. Finally, cytokines IL-1β, IL-6, and TNF-α levels, as well as MPO activity, were not altered. Our present data indicate that fructose provokes oxidative stress in the cerebral cortex, which induces oxidation of lipids and proteins and changes of CAT and SOD activities. It seems therefore reasonable to propose that antioxidants may serve as an adjuvant therapy to diets or to other pharmacological agents used for these patients, to avoid oxidative damage to the brain.

  1. Magnetic resonance imaging evaluation of acetabular orientation in normal Chinese children.

    PubMed

    Li, YiQiang; Liu, YuanZhong; Zhou, QingHe; Chen, WeiDong; Li, JingChun; Yu, LingJia; Xu, HongWen; Xie, DengHui

    2016-09-01

    There are no data regarding the acetabular orientation on magnetic resonance imaging (MRI); this study investigates the changes of acetabular orientation with age in normal Chinese children.We retrospectively analyzed the medical records of children who underwent hip MRI examination at our hospital from January 2009 to December 2015. A total of 180 patients with normal MRI reading of the hip joints were included and were divided into 14 groups according to age: from 6 months of age and then for each year from 1 to 16 years. The bony and cartilage acetabular anteversion angle (AAA), acetabular inclination angle (AIA), and acetabular index (AI) were measured. Total bony and cartilage femoral head coverage angles were measured on axial section total femoral head coverage angle (a-TCA) and coronal section total femoral head coverage angle (c-TCA).The mean bony AAA and AIA were 12.2 ± 2.5° and 50.9 ± 2.5°, respectively; both of them stayed constant from the age of 6 months to 16 years. Similar results were found in cartilage AAA (12.1 ± 2.5°) and AIA (41.2 ± 3.0°). There was no difference between bony and cartilage AAA, but bony AIA was significantly larger than cartilage AIA. Bony AI was 24.1 ± 2.4° at the age of 6 months, decreasing to 12.5 ± 2.3° by 12 to 13 years of age; cartilage AI (5.9 ± 1.7°) maintained a steady value with age. The mean bony a-TCA and c-TCA at 6 months were 117.0 ± 5.8° and 127.5 ± 5.1°, increasing to 144.5 ± 4.6° and 140.7 ± 2.5° at the age of 16 years. However, the cartilage a-TCA (145.2 ± 7.2°) and c-TCA (154.1 ± 5.7°) did not change significantly with age.Both bony and cartilage AAA and AIA remain constant up to the age of 16 years in normal Chinese pediatric population. Although the cartilage coverage of femoral head by the acetabulum remains unchanged with age, the bony coverage of femoral head increases. PMID:27631258

  2. Resonances and resonance widths

    SciTech Connect

    Collins, T.

    1986-05-01

    Two-dimensional betatron resonances are much more important than their simple one-dimensional counterparts and exhibit a strong dependence on the betatron phase advance per cell. A practical definition of ''width'' is expanded upon in order to display these relations in tables. A primarily pedagogical introduction is given to explain the tables, and also to encourage a wider capability for deriving resonance behavior and wider use of ''designer'' resonances.

  3. Liver steatosis (LS) evaluated through chemical-shift magnetic resonance imaging liver enzymes in morbid obesity; effect of weight loss obtained with intragastric balloon gastric banding.

    PubMed

    Folini, Laura; Veronelli, Annamaria; Benetti, Alberto; Pozzato, Carlo; Cappelletti, Marco; Masci, Enzo; Micheletto, Giancarlo; Pontiroli, Antonio E

    2014-01-01

    The aim of this study was to evaluate in morbid obesity clinical and metabolic effects related to weight loss on liver steatosis (LS), measured through chemical-shift magnetic resonance imaging (MRI) and liver enzymes. Forty obese subjects (8 M/32 W; BMI 42.8 ± 7.12 kg/m(2), mean ± SD) were evaluated for LS through ultrasound (US-LS), chemical-shift MRI (MRI-LS), liver enzymes [aspartate aminotransferase (AST), alanine aminotransferase (ALT), γ-glutamyltransferase (GGT), alkaline phosphatase (ALP)], anthropometric parameters [weight, BMI, waist circumference (WC)], lipids, insulin, insulin resistance (HOMA-IR), glycated hemoglobin (HbA1c), oral glucose tolerance test, and body composition [fat mass (FM) and fat-free mass (FFM) at bio-impedance analysis (BIA)]. Anthropometric measures, MRI-LS, BIA, and biochemical parameters were reevaluated 6 months later in 18 subjects undergoing restrictive bariatric approach, i.e., intragastric balloon (BIB, n = 13) or gastric banding (LAGB, n = 5), and in 13 subjects receiving hypocaloric diet. At baseline, US-LS correlates only with MRI-LS, and the latter correlates with ALT, AST, and GGT. After 6 months, subjects undergoing BIB or LAGB had significant changes of BMI, weight, WC, ALT, AST, GGT, ALP, HbA1c, insulin, HOMA-IR, FM, FFM, and MRI-LS. Diet-treated obese subjects had no significant change of any parameter under study; change of BMI, fat mass, and fat-free mass was significantly greater in LAGB/BIB subjects than in diet-treated subjects. Change of MRI-LS showed a significant correlation with changes in weight, BMI, WC, GGT, ALP, and basal MRI-LS. Significant weight loss after BIB or LAGB is associated with decrease in chemical-shift MRI-LS and with reduction in liver enzymes; chemical-shift MRI and liver enzymes allow monitoring of LS in follow-up studies.

  4. Evaluation of range parameters of the cameras for security system protecting the selected critical infrastructure of seaport

    NASA Astrophysics Data System (ADS)

    Kastek, Mariusz; Barela, Jaroslaw; Zyczkowski, Marek; Dulski, Rafal; Trzaskawka, Piotr; Firmanty, Krzysztof; Kucharz, Juliusz

    2012-10-01

    There are many separated infrastructural objects within a harbor area that may be considered "critical", such as gas and oil terminals or anchored naval vessels. Those objects require special protection, including security systems capable of monitoring both surface and underwater areas, because an intrusion into the protected area may be attempted using small surface vehicles (boats, kayaks, rafts, floating devices with weapons and explosives) as well as underwater ones (manned or unmanned submarines, scuba divers). The cameras used in security systems operate in several different spectral ranges in order to improve the probability of detection of incoming objects (potential threats). The cameras should then have adequate range parameters for detection, recognition and identification and those parameters, both measured and obtained through numerical simulations, will be presented in the paper. The range parameters of thermal cameras were calculated using NVTherm software package. Parameters of four observation thermal cameras were also measured on a specialized test stand at Institute of Optoelectronics, MUT. This test stand makes it also possible to test visual cameras. The parameters of five observation cameras working in the visual range were measured and on the basis of those data the detection, recognition and identification ranges were determined. The measurement results and simulation data will be compared. The evaluation of range parameters obtained for the tested camera types will define their usability in the real security system for the protection of selected critical infrastructure of a seaport.small surface objects (such as RIB boats) by a camera system and real test results in various weather conditions will also be presented.

  5. Clinical value of real-time elastography quantitative parameters in evaluating the stage of liver fibrosis and cirrhosis

    PubMed Central

    GE, LAN; SHI, BAOMIN; SONG, YE; LI, YUAN; WANG, SHUO; WANG, XIUYAN

    2015-01-01

    The aim of the present study was to assess the value of real-time elastography (RTE) quantitative parameters, namely the liver fibrosis (LF) index and the ratio of blue area (%AREA), in evaluating the stage of liver fibrosis. RTE quantitative analysis software was used to examine 120 patients with chronic hepatitis in order to obtain the values for 12 quantitative parameters from the elastic images. The diagnostic performance of two such parameters, the LF index and %AREA, were assessed with a receiver operating characteristic (ROC) curve to determine the optimal diagnostic cut-off values for liver cirrhosis and fibrosis. A good correlation was observed between the LF index and %AREA with the fibrosis stage. The areas under the ROC curve for the LF index were 0.985 for the diagnosis of liver cirrhosis and 0.790 for liver fibrosis. With regard to %AREA, the areas under the ROC curve for the diagnosis of liver cirrhosis and fibrosis were 0.963 and 0.770, respectively. An LF index of >3.25 and a %AREA of >28.83 for the diagnosis of cirrhosis stage resulted in sensitivity values of 100 and 100%, specificity values of 88.9 and 85.9% and accuracy values of 90.8 and 88.3%, respectively. The LF index and %AREA parameters exhibited higher reliability in the diagnosis of liver cirrhosis compared with the diagnosis of the liver fibrosis stage. However, the two parameters possessed a similar efficacy in the diagnosis of liver cirrhosis and the stage of liver fibrosis. Therefore, the quantitative RTE parameters of the LF index and %AREA may be clinically applicable as reliable indices for the early diagnosis of liver cirrhosis, without the requirement of an invasive procedure. PMID:26622426

  6. Evaluation of transverse dispersion effects in tank experiments by numerical modeling: parameter estimation, sensitivity analysis and revision of experimental design.

    PubMed

    Ballarini, E; Bauer, S; Eberhardt, C; Beyer, C

    2012-06-01

    Transverse dispersion represents an important mixing process for transport of contaminants in groundwater and constitutes an essential prerequisite for geochemical and biodegradation reactions. Within this context, this work describes the detailed numerical simulation of highly controlled laboratory experiments using uranine, bromide and oxygen depleted water as conservative tracers for the quantification of transverse mixing in porous media. Synthetic numerical experiments reproducing an existing laboratory experimental set-up of quasi two-dimensional flow through tank were performed to assess the applicability of an analytical solution of the 2D advection-dispersion equation for the estimation of transverse dispersivity as fitting parameter. The fitted dispersivities were compared to the "true" values introduced in the numerical simulations and the associated error could be precisely estimated. A sensitivity analysis was performed on the experimental set-up in order to evaluate the sensitivities of the measurements taken at the tank experiment on the individual hydraulic and transport parameters. From the results, an improved experimental set-up as well as a numerical evaluation procedure could be developed, which allow for a precise and reliable determination of dispersivities. The improved tank set-up was used for new laboratory experiments, performed at advective velocities of 4.9 m d(-1) and 10.5 m d(-1). Numerical evaluation of these experiments yielded a unique and reliable parameter set, which closely fits the measured tracer concentration data. For the porous medium with a grain size of 0.25-0.30 mm, the fitted longitudinal and transverse dispersivities were 3.49×10(-4) m and 1.48×10(-5) m, respectively. The procedures developed in this paper for the synthetic and rigorous design and evaluation of the experiments can be generalized and transferred to comparable applications. PMID:22575873

  7. Evaluation of transverse dispersion effects in tank experiments by numerical modeling: parameter estimation, sensitivity analysis and revision of experimental design.

    PubMed

    Ballarini, E; Bauer, S; Eberhardt, C; Beyer, C

    2012-06-01

    Transverse dispersion represents an important mixing process for transport of contaminants in groundwater and constitutes an essential prerequisite for geochemical and biodegradation reactions. Within this context, this work describes the detailed numerical simulation of highly controlled laboratory experiments using uranine, bromide and oxygen depleted water as conservative tracers for the quantification of transverse mixing in porous media. Synthetic numerical experiments reproducing an existing laboratory experimental set-up of quasi two-dimensional flow through tank were performed to assess the applicability of an analytical solution of the 2D advection-dispersion equation for the estimation of transverse dispersivity as fitting parameter. The fitted dispersivities were compared to the "true" values introduced in the numerical simulations and the associated error could be precisely estimated. A sensitivity analysis was performed on the experimental set-up in order to evaluate the sensitivities of the measurements taken at the tank experiment on the individual hydraulic and transport parameters. From the results, an improved experimental set-up as well as a numerical evaluation procedure could be developed, which allow for a precise and reliable determination of dispersivities. The improved tank set-up was used for new laboratory experiments, performed at advective velocities of 4.9 m d(-1) and 10.5 m d(-1). Numerical evaluation of these experiments yielded a unique and reliable parameter set, which closely fits the measured tracer concentration data. For the porous medium with a grain size of 0.25-0.30 mm, the fitted longitudinal and transverse dispersivities were 3.49×10(-4) m and 1.48×10(-5) m, respectively. The procedures developed in this paper for the synthetic and rigorous design and evaluation of the experiments can be generalized and transferred to comparable applications.

  8. Comprehensive Evaluation of Personal, Clinical, and Radiation Dosimetric Parameters for Acute Skin Reaction during Whole Breast Radiotherapy

    PubMed Central

    Yang, Dae Sik; Lee, Jung Ae; Lee, Nam Kwon; Park, Young Je; Lee, Suk; Kim, Chul Yong; Son, Gil Soo

    2016-01-01

    Skin reaction is major problem during whole breast radiotherapy. To identify factors related to skin reactions during whole breast radiotherapy, various personal, clinical, and radiation dosimetric parameters were evaluated. From January 2012 to December 2013, a total of 125 patients who underwent breast conserving surgery and adjuvant whole breast irradiation were retrospectively reviewed. All patients had both whole breast irradiation and boost to the tumour bed. Skin reaction was measured on the first day of boost therapy based on photography of the radiation field and medical records. For each area of axilla and inferior fold, the intensity score of erythema (score 1 to 5) and extent (score 0 to 1) were summed. The relationship of various parameters to skin reaction was evaluated using chi-square and linear regression tests. The V100 (volume receiving 100% of prescribed radiation dose, p < 0.001, both axilla and inferior fold) and age (p = 0.039 for axilla and 0.026 for inferior fold) were significant parameters in multivariate analyses. The calculated axilla dose (p = 0.003) and breast separation (p = 0.036) were also risk factors for axilla and inferior fold, respectively. Young age and large V100 are significant factors for acute skin reaction that can be simply and cost-effectively measured. PMID:27579310

  9. Implementation and Evaluation of the Virtual Fields Method: Determining Constitutive Model Parameters From Full-Field Deformation Data.

    SciTech Connect

    Kramer, Sharlotte Lorraine Bolyard; Scherzinger, William M.

    2014-09-01

    The Virtual Fields Method (VFM) is an inverse method for constitutive model parameter identication that relies on full-eld experimental measurements of displacements. VFM is an alternative to standard approaches that require several experiments of simple geometries to calibrate a constitutive model. VFM is one of several techniques that use full-eld exper- imental data, including Finite Element Method Updating (FEMU) techniques, but VFM is computationally fast, not requiring iterative FEM analyses. This report describes the im- plementation and evaluation of VFM primarily for nite-deformation plasticity constitutive models. VFM was successfully implemented in MATLAB and evaluated using simulated FEM data that included representative experimental noise found in the Digital Image Cor- relation (DIC) optical technique that provides full-eld displacement measurements. VFM was able to identify constitutive model parameters for the BCJ plasticity model even in the presence of simulated DIC noise, demonstrating VFM as a viable alternative inverse method. Further research is required before VFM can be adopted as a standard method for constitu- tive model parameter identication, but this study is a foundation for ongoing research at Sandia for improving constitutive model calibration.

  10. Comprehensive Evaluation of Personal, Clinical, and Radiation Dosimetric Parameters for Acute Skin Reaction during Whole Breast Radiotherapy.

    PubMed

    Yang, Dae Sik; Lee, Jung Ae; Yoon, Won Sup; Lee, Nam Kwon; Park, Young Je; Lee, Suk; Kim, Chul Yong; Son, Gil Soo

    2016-01-01

    Skin reaction is major problem during whole breast radiotherapy. To identify factors related to skin reactions during whole breast radiotherapy, various personal, clinical, and radiation dosimetric parameters were evaluated. From January 2012 to December 2013, a total of 125 patients who underwent breast conserving surgery and adjuvant whole breast irradiation were retrospectively reviewed. All patients had both whole breast irradiation and boost to the tumour bed. Skin reaction was measured on the first day of boost therapy based on photography of the radiation field and medical records. For each area of axilla and inferior fold, the intensity score of erythema (score 1 to 5) and extent (score 0 to 1) were summed. The relationship of various parameters to skin reaction was evaluated using chi-square and linear regression tests. The V 100 (volume receiving 100% of prescribed radiation dose, p < 0.001, both axilla and inferior fold) and age (p = 0.039 for axilla and 0.026 for inferior fold) were significant parameters in multivariate analyses. The calculated axilla dose (p = 0.003) and breast separation (p = 0.036) were also risk factors for axilla and inferior fold, respectively. Young age and large V 100 are significant factors for acute skin reaction that can be simply and cost-effectively measured. PMID:27579310

  11. Theoretical studies of the local structures and electron paramagnetic resonance parameters for Cu2+ center in Zn(C3H3O4)2(H2O)2 single crystal

    NASA Astrophysics Data System (ADS)

    Zhang, Hua-Ming; Xiao, Wen-Bo; Wan, Xiong

    2014-07-01

    The electron paramagnetic resonance (EPR) parameters (g factors gxx, gyy, gzz and hyperfine structure constants Axx, Ayy, Azz) are interpreted by taking account of the admixture of d-orbitals in the ground state wave function of the Cu2+ ion in a Zn(C3H3O4)2(H2O)2 (DABMZ) single crystal. Based on the calculation, local structural parameters of the impurity Cu2+ center were obtained (i.e. Ra≈1.92 Å, Rb≈1.96 Å, Rc≈1.99 Å). The theoretical EPR parameters based on the above Cu2+-O2- bond lengths in the DABMZ crystal show good agreement with the observed values and some improvements have been made as compared with those in the previous studies.

  12. Comparing a simple methodology to evaluate hydrodynamic parameters with rainfall simulation experiments

    NASA Astrophysics Data System (ADS)

    Di Prima, Simone; Bagarello, Vincenzo; Bautista, Inmaculada; Burguet, Maria; Cerdà, Artemi; Iovino, Massimo; Prosdocimi, Massimo

    2016-04-01

    Studying soil hydraulic properties is necessary for interpreting and simulating many hydrological processes having environmental and economic importance, such as rainfall partition into infiltration and runoff. The saturated hydraulic conductivity, Ks, exerts a dominating influence on the partitioning of rainfall in vertical and lateral flow paths. Therefore, estimates of Ks are essential for describing and modeling hydrological processes (Zimmermann et al., 2013). According to several investigations, Ks data collected by ponded infiltration tests could be expected to be unusable for interpreting field hydrological processes, and particularly infiltration. In fact, infiltration measured by ponding give us information about the soil maximum or potential infiltration rate (Cerdà, 1996). Moreover, especially for the hydrodynamic parameters, many replicated measurements have to be carried out to characterize an area of interest since they are known to vary widely both in space and time (Logsdon and Jaynes, 1996; Prieksat et al., 1994). Therefore, the technique to be applied at the near point scale should be simple and rapid. Bagarello et al. (2014) and Alagna et al. (2015) suggested that the Ks values determined by an infiltration experiment carried applying water at a relatively large distance from the soil surface could be more appropriate than those obtained with a low height of water pouring to explain surface runoff generation phenomena during intense rainfall events. These authors used the Beerkan Estimation of Soil Transfer parameters (BEST) procedure for complete soil hydraulic characterization (Lassabatère et al., 2006) to analyze the field infiltration experiment. This methodology, combining low and high height of water pouring, seems appropriate to test the effect of intense and prolonged rainfall events on the hydraulic characteristics of the surface soil layer. In fact, an intense and prolonged rainfall event has a perturbing effect on the soil surface

  13. Rainfall-induced release of microbes from manure: model development, parameter estimation, and uncertainty evaluation on small plots.

    PubMed

    Kim, Keewook; Whelan, Gene; Molina, Marirosa; Purucker, S Thomas; Pachepsky, Yakov; Guber, Andrey; Cyterski, Michael J; Franklin, Dorcas H; Blaustein, Ryan A

    2016-06-01

    A series of simulated rainfall-runoff experiments with applications of different manure types (cattle solid pats, poultry dry litter, swine slurry) was conducted across four seasons on a field containing 36 plots (0.75 × 2 m each), resulting in 144 rainfall-runoff events. Simulating time-varying release of Escherichia coli, enterococci, and fecal coliforms from manures applied at typical agronomic rates evaluated the efficacy of the Bradford-Schijven model modified by adding terms for release efficiency and transportation loss. Two complementary, parallel approaches were used to calibrate the model and estimate microbial release parameters. The first was a four-step sequential procedure using the inverse model PEST, which provides appropriate initial parameter values. The second utilized a PEST/bootstrap procedure to estimate average parameters across plots, manure age, and microbe, and to provide parameter distributions. The experiment determined that manure age, microbe, and season had no clear relationship to the release curve. Cattle solid pats released microbes at a different, slower rate than did poultry dry litter or swine slurry, which had very similar release patterns. These findings were consistent with other published results for both bench- and field-scale, suggesting the modified Bradford-Schijven model can be applied to microbial release from manure. PMID:27280610

  14. Rainfall-induced release of microbes from manure: model development, parameter estimation, and uncertainty evaluation on small plots.

    PubMed

    Kim, Keewook; Whelan, Gene; Molina, Marirosa; Purucker, S Thomas; Pachepsky, Yakov; Guber, Andrey; Cyterski, Michael J; Franklin, Dorcas H; Blaustein, Ryan A

    2016-06-01

    A series of simulated rainfall-runoff experiments with applications of different manure types (cattle solid pats, poultry dry litter, swine slurry) was conducted across four seasons on a field containing 36 plots (0.75 × 2 m each), resulting in 144 rainfall-runoff events. Simulating time-varying release of Escherichia coli, enterococci, and fecal coliforms from manures applied at typical agronomic rates evaluated the efficacy of the Bradford-Schijven model modified by adding terms for release efficiency and transportation loss. Two complementary, parallel approaches were used to calibrate the model and estimate microbial release parameters. The first was a four-step sequential procedure using the inverse model PEST, which provides appropriate initial parameter values. The second utilized a PEST/bootstrap procedure to estimate average parameters across plots, manure age, and microbe, and to provide parameter distributions. The experiment determined that manure age, microbe, and season had no clear relationship to the release curve. Cattle solid pats released microbes at a different, slower rate than did poultry dry litter or swine slurry, which had very similar release patterns. These findings were consistent with other published results for both bench- and field-scale, suggesting the modified Bradford-Schijven model can be applied to microbial release from manure.

  15. Hemoglobin levels and circulating blasts are two easily evaluable diagnostic parameters highly predictive of leukemic transformation in primary myelofibrosis.

    PubMed

    Rago, Angela; Latagliata, Roberto; Montanaro, Marco; Montefusco, Enrico; Andriani, Alessandro; Crescenzi, Sabrina Leonetti; Mecarocci, Sergio; Spirito, Francesca; Spadea, Antonio; Recine, Umberto; Cicconi, Laura; Avvisati, Giuseppe; Cedrone, Michele; Breccia, Massimo; Porrini, Raffaele; Villivà, Nicoletta; De Gregoris, Cinzia; Alimena, Giuliana; D'Arcangelo, Enzo; Guglielmelli, Paola; Lo-Coco, Francesco; Vannucchi, Alessandro; Cimino, Giuseppe

    2015-03-01

    To predict leukemic transformation (LT), we evaluated easily detectable diagnostic parameters in 338 patients with primary myelofibrosis (PMF) followed in the Latium region (Italy) between 1981 and 2010. Forty patients (11.8%) progressed to leukemia, with a resulting 10-year leukemia-free survival (LFS) rates of 72%. Hb (<10g/dL), and circulating blasts (≥1%) were the only two independent prognostic for LT at the multivariate analysis. Two hundred-fifty patients with both the two parameters available were grouped as follows: low risk (none or one factor)=216 patients; high risk (both factors)=31 patients. The median LFS times were 269 and 45 months for the low and high-risk groups, respectively (P<.0001). The LT predictive power of these two parameters was confirmed in an external series of 270 PMF patients from Tuscany, in whom the median LFS was not reached and 61 months for the low and high risk groups, respectively (P<.0001). These results establish anemia and circulating blasts, two easily and universally available parameters, as strong predictors of LT in PMF and may help to improve prognostic stratification of these patients particularly in countries with low resources where more sophisticated molecular testing is unavailable. PMID:25636356

  16. In vivo evaluation of a breast-specific magnetic resonance guided focused ultrasound system in a goat udder model

    PubMed Central

    Payne, A.; Todd, N.; Minalga, E.; Wang, Y.; Diakite, M.; Hadley, R.; Merrill, R.; Factor, R.; Neumayer, L.; Parker, D. L.

    2013-01-01

    Purpose: This work further evaluates the functionality, efficacy, and safety of a new breast-specific magnetic resonance guided high intensity focused ultrasound (MRgFUS) system in an in vivo goat udder model. Methods: Eight female goats underwent an MRgFUS ablation procedure using the breast-specific MRgFUS system. Tissue classification was achieved through the 3D magnetic resonance imaging (MRI) acquisition of several contrasts (T1w, T2w, PDw, 3-point Dixon). The MRgFUS treatment was performed with a grid trajectory executed in one or two planes within the glandular tissue of the goat udder. Temperature was monitored using a 3D proton resonance frequency (PRF) MRI technique. Delayed contrast enhanced-MR images were acquired immediately and 14 days post MRgFUS treatment. A localized tissue excision was performed in one animal and histological analysis was performed. Animals were available for adoption at the conclusion of the study. Results: The breast-specific MRgFUS system was able to ablate regions ranging in size from 0.4 to 3.6 cm3 in the goat udder model. Tissue damage was confirmed through the correlation of thermal dose measurements obtained with realtime 3D MR thermometry to delayed contrast enhanced-MR images immediately after the treatment and 14 days postablation. In general, lesions were longer in the ultrasound propagation direction, which is consistent with the dimensions of the ultrasound focal spot. Thermal dose volumes had better agreement with nonenhancing areas of the DCE-MRI images obtained 14 days after the MRgFUS treatment. Conclusions: The system was able to successfully ablate lesions up to 3.6 cm3. The thermal dose volume was found to correlate better with the 14-day postablation nonenhancing delayed contrast enhanced-MR image volumes. While the goat udder is not an ideal model for the human breast, this study has proven the feasibility of using this system on a wide variety of udder shapes and sizes, demonstrating the flexibility that

  17. A pendulum test as a tool to evaluate viscous friction parameters in the equine fetlock joint.

    PubMed

    Noble, Prisca; Lumay, Geoffroy; Coninx, Marc; Collin, Bernard; Magnée, Adrien; Lecomte-Beckers, Jacqueline; Denoix, Jean M; Serteyn, Didier

    2011-05-01

    An equine fetlock joint pendulum test was studied and the influence of post mortem time and intra-articular lipid solvent on the viscous frictional response examined. Fresh equine digits (group 1, n=6 controls; group 2, n=6 lipid solvent) were mounted on a pendulum tribometer. Assuming that pendular joint damping could be modelled by a harmonic oscillator fluid damping (HOFD), damping time (τ), viscous damping coefficient (c) and friction coefficient (μ) were monitored for 5h under experimental conditions (400N; 20°C). In all experiments, pendular joint damping was found to follow an exponential decay function (R(2)=0.99714), which confirmed that joint damping was fluid. The evolution of τ, c and μ was found to be significantly (P<0.05) different in the two groups, with a decrease in τ and an increase in c and μ that was faster and more prominent in digits from group 2. It was concluded that pendular joint damping could be modelled by a HOFD model. The influence of post mortem time on results suggested that, ideally, joint mechanical properties should only be tested on fresh cadavers at the same post mortem time. Moreover, the addition of lipid solvent was found to be responsible for upper viscous friction parameters and for a reduced damping time, which suggested that articular lubricating ability was compromised. This equine pendulum test could be used to test the efficacy of various bio-lubricant treatments.

  18. A pendulum test as a tool to evaluate viscous friction parameters in the equine fetlock joint.

    PubMed

    Noble, Prisca; Lumay, Geoffroy; Coninx, Marc; Collin, Bernard; Magnée, Adrien; Lecomte-Beckers, Jacqueline; Denoix, Jean M; Serteyn, Didier

    2011-05-01

    An equine fetlock joint pendulum test was studied and the influence of post mortem time and intra-articular lipid solvent on the viscous frictional response examined. Fresh equine digits (group 1, n=6 controls; group 2, n=6 lipid solvent) were mounted on a pendulum tribometer. Assuming that pendular joint damping could be modelled by a harmonic oscillator fluid damping (HOFD), damping time (τ), viscous damping coefficient (c) and friction coefficient (μ) were monitored for 5h under experimental conditions (400N; 20°C). In all experiments, pendular joint damping was found to follow an exponential decay function (R(2)=0.99714), which confirmed that joint damping was fluid. The evolution of τ, c and μ was found to be significantly (P<0.05) different in the two groups, with a decrease in τ and an increase in c and μ that was faster and more prominent in digits from group 2. It was concluded that pendular joint damping could be modelled by a HOFD model. The influence of post mortem time on results suggested that, ideally, joint mechanical properties should only be tested on fresh cadavers at the same post mortem time. Moreover, the addition of lipid solvent was found to be responsible for upper viscous friction parameters and for a reduced damping time, which suggested that articular lubricating ability was compromised. This equine pendulum test could be used to test the efficacy of various bio-lubricant treatments. PMID:20413334

  19. An evaluation of the critical parameters for abiotic peptide synthesis in submarine hydrothermal systems.

    PubMed

    Cleaves, H J; Aubrey, A D; Bada, J L

    2009-04-01

    It has been proposed that oligopeptides may be formed in submarine hydrothermal systems (SHSs). Oligopeptides have been synthesized previously under simulated SHS conditions which are likely geochemically implausible. We have herein investigated the oligomerization of glycine under SHS-like conditions with respect to the limitations imposed by starting amino acid concentration, heating time, and temperature. When 10(-1) M glycine solutions were heated at 250 degrees C for < 20 min glycine oligomers up to tetramers and diketopiperazine (DKP) were detectable. At 200 degrees C, less oligomerization was noted. Peptides beyond glycylglycine (gly2) and DKP were not detected below 150 degrees C. At 10(-2) M initial glycine concentration and below, only gly2, DKP, and gly3 were detected, and then only above 200 degrees C at < 20 min reaction time. Gly3 was undetectable at longer reaction times. The major parameters limiting peptide synthesis in SHSs appear to be concentration, time, and temperature. Given the expected low concentrations of amino acids, the long residence times and range of temperatures in SHSs, it is unlikely that SHS environments were robust sources of even simple peptides. Possible unexplored solutions to the problems presented here are also discussed. PMID:19037745

  20. Performance evaluation and parameter sensitivity of energy-harvesting shock absorbers on different vehicles

    NASA Astrophysics Data System (ADS)

    Guo, Sijing; Liu, Yilun; Xu, Lin; Guo, Xuexun; Zuo, Lei

    2016-07-01

    Traditional shock absorbers provide favourable ride comfort and road handling by dissipating the suspension vibration energy into heat waste. In order to harvest this dissipated energy and improve the vehicle fuel efficiency, many energy-harvesting shock absorbers (EHSAs) have been proposed in recent years. Among them, two types of EHSAs have attracted much attention. One is a traditional EHSA which converts the oscillatory vibration into bidirectional rotation using rack-pinion, ball-screw or other mechanisms. The other EHSA is equipped with a mechanical motion rectifier (MMR) that transforms the bidirectional vibration into unidirectional rotation. Hereinafter, they are referred to as NonMMR-EHSA and MMR-EHSA, respectively. This paper compares their performances with the corresponding traditional shock absorber by using closed-form analysis and numerical simulations on various types of vehicles, including passenger cars, buses and trucks. Results suggest that MMR-EHSA provides better ride performances than NonMMR-EHSA, and that MMR-EHSA is able to improve both the ride comfort and road handling simultaneously over the traditional shock absorber when installed on light-damped, heavy-duty vehicles. Additionally, the optimal parameters of MMR-EHSA are obtained for ride comfort. The optimal solutions ('Pareto-optimal solutions') are also obtained by considering the trade-off between ride comfort and road handling.

  1. Effects of some lubricants and evaluation of compression parameters on directly compressible powders.

    PubMed

    Uğurlu, Timuçin; Halaçoğlu, Mekin Doğa

    2014-05-01

    The objective of this study was to investigate the effects of conventional lubricants including a new candidate lubricant "Hexagonal boron nitride (HBN)" on direct compression powders. Lubricants such as magnesium stearate, glyceryl behenate, stearic acid, talc and polyethylene glycol6000 were studied in this article. Tablets were manufactured on an instrumented tablet press with various lubricant concentrations. Bulk and tapped densities, and Carr's index parameters were calculated for powders. Tensile strength, cohesion index, lower punch ejection force and lubricant effectiveness values were investigated for tablets. The deformation mechanisms of tablets were studied during compression from the Heckel plots with or without lubricants. Powders formulated with MGST and HBN showed better flow properties based on Carr's index. MGST was found to be the most effective lubricant based on lubricant effectiveness for tablets. HBN was found very close to MGST with the same concentrations. Other lubricants showed less effectiveness than that of MGST and HBN. It is observed that an increase in the concentration of HBN leads to decreased tensile strength and cohesion index values because of its surface-covering property. Despite covering property, HBN had no significant effect on disintegration time. Based on the Heckel plots at the level of 1%, HBN showed the most pronounced plastic character.

  2. Combining incidence and demographic modelling approaches to evaluate metapopulation parameters for an endangered riparian plant

    PubMed Central

    Charney, Noah D.; Record, Sydne

    2016-01-01

    Metapopulations are a central concept in ecology and conservation biology; however, estimating key parameters such as colonization rates presents a substantial obstacle to modelling metapopulations in many species. We develop spatial and non-spatial simulation models that combine incidence- and demographic-based approaches to build a relationship between observed patch occupancy, habitat turnover rates, colonization rates and dispersal scales. Applying these models to long-term observations of Pedicularis furbishiae (Furbish’s lousewort), a rare plant endemic to the Saint John River, we predict that observed habitat patches averaging 550 m in length receive colonizing seedlings with a yearly probability of 0.45 or 0.54, based on two different models. Predictions are consistent with a standard analytic metapopulation formulation modified to partition extinction drivers during the early and the late phases of a population’s life cycle. While the specific results rest on several simplifying assumptions, the models allow us to understand the impact that increasing rates of habitat turnover would have on the future survival of this species. PMID:27339047

  3. Cognitive Behavior Evaluation Based on Physiological Parameters among Young Healthy Subjects with Yoga as Intervention

    PubMed Central

    Nagendra, H.; Kumar, Vinod; Mukherjee, S.

    2015-01-01

    Objective. To investigate the effect of yoga practice on cognitive skills, autonomic nervous system, and heart rate variability by analyzing physiological parameters. Methods. The study was conducted on 30 normal young healthy engineering students. They were randomly selected into two groups: yoga group and control group. The yoga group practiced yoga one and half hour per day for six days in a week, for a period of five months. Results. The yoga practising group showed increased α, β, and δ EEG band powers and significant reduction in θ and γ band powers. The increased α and β power can represent enhanced cognitive functions such as memory and concentration, and that of δ signifies synchronization of brain activity. The heart rate index θ/α decreased, neural activity β/θ increased, attention resource index β/(α + θ) increased, executive load index (δ + θ)/α decreased, and the ratio (δ + θ)/(α + β) decreased. The yoga practice group showed improvement in heart rate variability, increased SDNN/RMSSD, and reduction in LF/HF ratio. Conclusion. Yoga practising group showed significant improvement in various cognitive functions, such as performance enhancement, neural activity, attention, and executive function. It also resulted in increase in the heart rate variability, parasympathetic nervous system activity, and balanced autonomic nervous system reactivity. PMID:25759746

  4. Combining incidence and demographic modelling approaches to evaluate metapopulation parameters for an endangered riparian plant.

    PubMed

    Charney, Noah D; Record, Sydne

    2016-01-01

    Metapopulations are a central concept in ecology and conservation biology; however, estimating key parameters such as colonization rates presents a substantial obstacle to modelling metapopulations in many species. We develop spatial and non-spatial simulation models that combine incidence- and demographic-based approaches to build a relationship between observed patch occupancy, habitat turnover rates, colonization rates and dispersal scales. Applying these models to long-term observations of Pedicularis furbishiae (Furbish's lousewort), a rare plant endemic to the Saint John River, we predict that observed habitat patches averaging 550 m in length receive colonizing seedlings with a yearly probability of 0.45 or 0.54, based on two different models. Predictions are consistent with a standard analytic metapopulation formulation modified to partition extinction drivers during the early and the late phases of a population's life cycle. While the specific results rest on several simplifying assumptions, the models allow us to understand the impact that increasing rates of habitat turnover would have on the future survival of this species. PMID:27339047

  5. [Comparison of clinical assessment and invasive evaluation of hemodynamic parameters in septic shock].

    PubMed

    Vucić, N; Pilas, V

    1995-06-01

    The authors compare, in this prospective study, the accuracy of their own clinical assessment of hemodynamic parameters and severity of disease with the findings obtained by right heart catheterization in 50 patients with septic shock. The purpose of the study was to determine whether Swan-Ganz catheter insertion was necessary in all patients with septic shock. As soon as the diagnosis was established, the value of pulmonary capillary wedge pressure was estimated, as well as presence or absence of pathological uptake/supply dependency in all patients. The latter is an excellent indicator of severity of disease. The accurate assessment was noted in 27 (54%) patients (1. investigator), and in 30 (60%) patients (2. investigator). The sensitivity of detection of pathological uptake/supply dependency amounted to 53% and 65%; specificity was 73% and 79%, respectively. The therapy was altered in 21 patients (42%) after catheter insertion. The results were tested with chi2-test (p < 0.01). The findings of this study warrant catheter insertion in patients with septic shock. PMID:8649145

  6. Effects of some lubricants and evaluation of compression parameters on directly compressible powders.

    PubMed

    Uğurlu, Timuçin; Halaçoğlu, Mekin Doğa

    2014-05-01

    The objective of this study was to investigate the effects of conventional lubricants including a new candidate lubricant "Hexagonal boron nitride (HBN)" on direct compression powders. Lubricants such as magnesium stearate, glyceryl behenate, stearic acid, talc and polyethylene glycol6000 were studied in this article. Tablets were manufactured on an instrumented tablet press with various lubricant concentrations. Bulk and tapped densities, and Carr's index parameters were calculated for powders. Tensile strength, cohesion index, lower punch ejection force and lubricant effectiveness values were investigated for tablets. The deformation mechanisms of tablets were studied during compression from the Heckel plots with or without lubricants. Powders formulated with MGST and HBN showed better flow properties based on Carr's index. MGST was found to be the most effective lubricant based on lubricant effectiveness for tablets. HBN was found very close to MGST with the same concentrations. Other lubricants showed less effectiveness than that of MGST and HBN. It is observed that an increase in the concentration of HBN leads to decreased tensile strength and cohesion index values because of its surface-covering property. Despite covering property, HBN had no significant effect on disintegration time. Based on the Heckel plots at the level of 1%, HBN showed the most pronounced plastic character. PMID:23590449

  7. An Evaluation of the Critical Parameters for Abiotic Peptide Synthesis in Submarine Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Cleaves, H. J.; Aubrey, A. D.; Bada, J. L.

    2009-04-01

    It has been proposed that oligopeptides may be formed in submarine hydrothermal systems (SHSs). Oligopeptides have been synthesized previously under simulated SHS conditions which are likely geochemically implausible. We have herein investigated the oligomerization of glycine under SHS-like conditions with respect to the limitations imposed by starting amino acid concentration, heating time, and temperature. When 10-1 M glycine solutions were heated at 250°C for < 20 min glycine oligomers up to tetramers and diketopiperazine (DKP) were detectable. At 200°C, less oligomerization was noted. Peptides beyond glycylglycine (gly2) and DKP were not detected below 150°C. At 10-2 M initial glycine concentration and below, only gly2, DKP, and gly3 were detected, and then only above 200°C at < 20 min reaction time. Gly3 was undetectable at longer reaction times. The major parameters limiting peptide synthesis in SHSs appear to be concentration, time, and temperature. Given the expected low concentrations of amino acids, the long residence times and range of temperatures in SHSs, it is unlikely that SHS environments were robust sources of even simple peptides. Possible unexplored solutions to the problems presented here are also discussed.

  8. Evaluation of synergistic antioxidant potential of complex mixtures using oxygen radical absorbance capacity (ORAC) and electron paramagnetic resonance (EPR).

    PubMed

    Parker, Tory L; Miller, Samantha A; Myers, Lauren E; Miguez, Fernando E; Engeseth, Nicki J

    2010-01-13

    Previous research has demonstrated that certain combinations of compounds result in a decrease in toxic or pro-oxidative effects, previously noted when compounds were administered singly. Thus, there is a need to study many complex interactions further. Two in vitro techniques [electron paramagnetic resonance (EPR) and oxygen radical absorbance capacity (ORAC) assays] were used in this study to assess pro- and antioxidant capacity and synergistic potential of various compounds. Rutin, p-coumaric acid, abscisic acid, ascorbic acid, and a sugar solution were evaluated individually at various concentrations and in all 26 possible combinations at concentrations found in certain foods (honey or papaya), both before and after simulated digestion. EPR results indicated sugar-containing combinations provided significantly higher antioxidant capacity; those combinations containing sugars and ascorbic acid demonstrated synergistic potential. The ORAC assay suggested additive effects, with some combinations having synergistic potential, although fewer combinations were significantly synergistic after digestion. Finally, ascorbic acid, caffeic acid, quercetin, and urate were evaluated at serum-achievable levels. EPR analysis did not demonstrate additive or synergistic potential, although ORAC analysis did, principally in combinations containing ascorbic acid.

  9. Evaluation of synergistic antioxidant potential of complex mixtures using oxygen radical absorbance capacity (ORAC) and electron paramagnetic resonance (EPR).

    PubMed

    Parker, Tory L; Miller, Samantha A; Myers, Lauren E; Miguez, Fernando E; Engeseth, Nicki J

    2010-01-13

    Previous research has demonstrated that certain combinations of compounds result in a decrease in toxic or pro-oxidative effects, previously noted when compounds were administered singly. Thus, there is a need to study many complex interactions further. Two in vitro techniques [electron paramagnetic resonance (EPR) and oxygen radical absorbance capacity (ORAC) assays] were used in this study to assess pro- and antioxidant capacity and synergistic potential of various compounds. Rutin, p-coumaric acid, abscisic acid, ascorbic acid, and a sugar solution were evaluated individually at various concentrations and in all 26 possible combinations at concentrations found in certain foods (honey or papaya), both before and after simulated digestion. EPR results indicated sugar-containing combinations provided significantly higher antioxidant capacity; those combinations containing sugars and ascorbic acid demonstrated synergistic potential. The ORAC assay suggested additive effects, with some combinations having synergistic potential, although fewer combinations were significantly synergistic after digestion. Finally, ascorbic acid, caffeic acid, quercetin, and urate were evaluated at serum-achievable levels. EPR analysis did not demonstrate additive or synergistic potential, although ORAC analysis did, principally in combinations containing ascorbic acid. PMID:19957934

  10. Magnetic Resonance Imaging Versus Computed Tomography and Different Imaging Modalities in Evaluation of Sinonasal Neoplasms Diagnosed by Histopathology

    PubMed Central

    Gomaa, Mohammed A.; Hammad, Moustafa S.; Abdelmoghny, Abobakr; Elsherif, Ashraf M.; Tawfik, Heba M.

    2013-01-01

    Objective The study purpose was to detect the value of magnetic resonance imaging (MRI) compared to computed tomography (CT) and different imaging modalities as conventional radiology in evaluation of sinonasal neoplasms diagnosed by Histopathology. Methods Thirty patients (16 males and 14 females) were complaining of symptoms related to sinonasal tract. After thorough clinical and local examination, the patients were subjected to the following: conventional radiography, CT, MRI, and histopathological examination. Results The nasal cavity was the most commonly involved site with sinonasal malignancies followed by the maxillary sinuses. The least commonly affected site was the frontal sinuses. Benign sinonasal tumors were present in 14 cases. The most common benign lesion was juvenile nasopharyngeal angiofibroma (6 cases), followed by inverted papilloma (3 cases). While malignant sinonasal tumors were present in 16 cases, squamous cell carcinoma was present in 5 cases, and undifferentiated carcinoma, in 3 cases. Lymphoepithelioma and non-Hodgkin lymphomas were present in 2 cases each, while adenocarcinoma, chondrosarcoma, adenoid cystic carcinoma, and rhabdomyosarcoma were present in 1 case each. Conclusion MRI with its superior soft tissue contrast and multiplanar capability is superior to CT in pretreatment evaluation of primary malignant tumors of sinonasal cavity. PMID:24179408

  11. Magnetic resonance evaluation of acetabular residual dysplasia in developmental dysplasia of the hip: a preliminary study of 27 patients.

    PubMed

    Douira-Khomsi, Wièm; Smida, Mahmoud; Louati, Hela; Hassine, Lilia Ben; Bouchoucha, Sami; Saied, Walid; Ladeb, Mohamed-Fethi; Ghachem, Maher Ben; Bellagha, Ibtissem

    2010-01-01

    Thirty-one hips in 27 young girls, treated for developmental dysplasia of the hip in the authors' institute since 2003, showed persistent radiographic evidence of residual acetabular dysplasia. These hips were registered as candidates for pelvic osteotomy. A prospective study was conducted and these hips were evaluated by magnetic resonance imaging (MRI); the average age of the patients was 5 years. MRI measurement of acetabular angle and acetabular head index in 2 different landmarks (bone and cartilage) was performed. The results were correlated with plain radiographic film evolution. MRI studies revealed sufficient cartilaginous acetabular coverage in 27 hips, cartilaginous acetabular dysplasia in 2 hips, and short acetabulum in 2 others. The 27 hips with thick cartilage of the acetabular roof were subsequently followed up by plain radiographs. The average follow-up period was 2.1 years. The authors observed a spontaneous progressive ossification of the cartilaginous acetabular roof in all the 27 cases. In 4 cases, the correction of the acetabular angle was complete. They concluded that MRI promotes more accurate selection of patients for pelvic osteotomy and aids in the choice of the most appropriate type of osteotomy. Clinical imaging examples are presented and need to be further evaluated.

  12. Diffusion-Weighted Magnetic Resonance Imaging to Evaluate Major Salivary Gland Function Before and After Radiotherapy

    SciTech Connect

    Dirix, Piet Keyzer, Frederik de; Vandecaveye, Vincent; Stroobants, Sigrid; Hermans, Robert; Nuyts, Sandra

    2008-08-01

    Purpose: To evaluate diffusion-weighted (DW)-MRI as a noninvasive tool to investigate major salivary gland function before and after radiotherapy (RT) for head and neck cancer (HNC). Methods and Materials: DW-MRI was performed in 8 HNC patients before and after parotid-sparing RT (mean dose to the contralateral parotid gland <26 Gy). A DW sequence was performed once at rest and then repeated continuously during salivary stimulation. Apparent diffusion coefficient (ADC) maps for both parotid and submandibular glands were calculated. Findings were compared with salivary gland scintigraphy. Results: Before RT, the mean ADC value at rest was significantly lower in the parotid than in the submandibular glands. During the first 5 min of stimulation, the ADC value of the salivary glands showed a decrease, followed by a steady increase until a peak ADC, significantly higher than the baseline value, was reached after a median of 17 min. The baseline ADC value at rest was significantly higher after RT than before RT in the nonspared salivary glands but not in the spared parotid glands. In the contralateral parotid glands, the same response was seen as before RT. This pattern was completely lost in the nonspared glands. These results corresponded with remaining or loss of salivary function, respectively, as confirmed by salivary gland scintigraphy. Conclusions: Diffusion-weighted-MRI allows noninvasive evaluation of functional changes in the major salivary glands after RT and is a promising tool for investigating radiation-induced xerostomia.

  13. Evaluation of functional severity of coronary artery disease and fluid dynamics' influence on hemodynamic parameters: A review.

    PubMed

    Govindaraju, Kalimuthu; Badruddin, Irfan Anjum; Viswanathan, Girish N; Ramesh, S V; Badarudin, A

    2013-05-01

    Coronary Artery Disease (CAD) is responsible for most of the deaths in patients with cardiovascular diseases. Diagnostic coronary angiography analysis offers an anatomical knowledge of the severity of the stenosis. The functional or physiological significance is more valuable than the anatomical significance of CAD. Clinicians assess the functional severity of the stenosis by resorting to an invasive measurement of the pressure drop and flow. Hemodynamic parameters, such as pressure wire assessment fractional flow reserve (FFR) or Doppler wire assessment coronary flow reserve (CFR) are well-proven techniques to evaluate the physiological significance of the coronary artery stenosis in the cardiac catheterization laboratory. Between the two techniques mentioned above, the FFR is seen as a very useful index. The presence of guide wire reduces the coronary flow which causes the underestimation of pressure drop across the stenosis which leads to dilemma for the clinicians in the assessment of moderate stenosis. In such condition, the fundamental fluid mechanics is useful in the development of new functional severity parameters such as pressure drop coefficient and lesion flow coefficient. Since the flow takes place in a narrowed artery, the blood behaves as a non-Newtonian fluid. Computational fluid dynamics (CFD) allows a complete coronary flow simulation to study the relationship between the pressure and flow. This paper aims at explaining (i) diagnostic modalities for the evaluation of the CAD and valuable insights regarding FFR in the evaluation of the functional severity of the CAD (ii) the role of fluid dynamics in measuring the severity of CAD. PMID:22704601

  14. An optimized wild bootstrap method for evaluation of measurement uncertainties of DTI-derived parameters in human brain.

    PubMed

    Zhu, Tong; Liu, Xiaoxu; Connelly, Patrick R; Zhong, Jianhui

    2008-04-15

    Evaluation of measurement uncertainties (or errors) in diffusion tensor-derived parameters is essential to quantify the sensitivity and specificity of these quantities as potential surrogate biomarkers for pathophysiological processes with diffusion tensor imaging (DTI). Computational methods such as the Monte Carlo simulation have provided insights into characterization of the measurement uncertainty in DTI. However, due to the complexity of real brain data as well as different sources of variations during the image acquisition, a robust estimator for DTI measurement uncertainty in human brain is required. Recent studies have shown that wild bootstrap, a novel nonparametric statistical method, can potentially provide effective estimations of DTI measurement uncertainties in human brain DTI data. In this study, we further optimized the DTI application of the wild bootstrap method for typical clinical applications. We evaluated the validity of wild bootstrap utilizing numerical simulations with different combinations of DTI protocol parameters and wild bootstrap experimental designs, and quantitatively compared estimates of uncertainties from wild bootstrapping with those from Monte Carlo simulations. Our results demonstrate that a wild bootstrap implementation using at least 1000 wild bootstrap iterations with a type II or type III heteroskedasticity consistent covariance matrix estimator provides robust evaluations of most DTI protocols.

  15. Genetic parameters of three methods of temperament evaluation of Brahman calves.

    PubMed

    Schmidt, S E; Neuendorff, D A; Riley, D G; Vann, R C; Willard, S T; Welsh, T H; Randel, R D

    2014-07-01

    The objective of this study was to estimate the heritability of 3 measures of temperament in Brahman and Brahman-influenced calves (n = 1,209). Individual animal pen scores (PS) were determined by a trained observer who evaluated groups of 5 or 4 calves at a time for willingness to be approached by a human. Exit velocity (EV) was the rate (m/s) at which each calf exited a squeeze chute. Temperament score (TS) was calculated individually as (PS + EV)/2. Temperament was evaluated at 5 different times of record (28 d preweaning, weaning, 28 d postweaning, 56 d postweaning, and yearling). Contemporary groups (n = 34) comprised calves of the same sex born in the same season of the same year. There were an average of 36 calves per contemporary group and group size ranged from 3 to 78 calves. Average weaning age (186 d) ranged from 105 to 304 d. Calves were born from 2002 through 2012. Random effects included additive genetic and the permanent environmental variance. The fixed effects analyzed were age of dam, sex of calf, contemporary group, fraction of Brahman (2 levels: 1 and 0.5), age of calf at record, and weaning age. At weaning, the mean PS was 2.68 ± 0.1, the mean EV was 2.41 ± 0.1, and the mean TS was 2.48 ± 0.1. The PS was affected by fraction of Brahman (P = 0.034) and tended to be affected by age of dam (P = 0.06). The EV was affected by contemporary group (P < 0.001) and tended to be affected by weaning age (P = 0.074). Contemporary group affected TS (P < 0.001). All 3 methods of temperament evaluation were affected by time of record (P < 0.001). The regression coefficients for PS, EV, and TS were 0.0023 ± 0.0014, 0.0022 ± 0.0012, and 0.0015 ± 0.0012 m·s(-1)·d(-1) of age, respectively. Estimates of maternal genetic effects were always 0 and omitted from final models. Estimates of heritability were 0.27 ± 0.1, 0.49 ± 0.1, and 0.43 ± 0.1 for EV, PS, and TS, respectively. Estimates of permanent environmental variances as proportions of phenotypic

  16. Genetic parameters of three methods of temperament evaluation of Brahman calves.

    PubMed

    Schmidt, S E; Neuendorff, D A; Riley, D G; Vann, R C; Willard, S T; Welsh, T H; Randel, R D

    2014-07-01

    The objective of this study was to estimate the heritability of 3 measures of temperament in Brahman and Brahman-influenced calves (n = 1,209). Individual animal pen scores (PS) were determined by a trained observer who evaluated groups of 5 or 4 calves at a time for willingness to be approached by a human. Exit velocity (EV) was the rate (m/s) at which each calf exited a squeeze chute. Temperament score (TS) was calculated individually as (PS + EV)/2. Temperament was evaluated at 5 different times of record (28 d preweaning, weaning, 28 d postweaning, 56 d postweaning, and yearling). Contemporary groups (n = 34) comprised calves of the same sex born in the same season of the same year. There were an average of 36 calves per contemporary group and group size ranged from 3 to 78 calves. Average weaning age (186 d) ranged from 105 to 304 d. Calves were born from 2002 through 2012. Random effects included additive genetic and the permanent environmental variance. The fixed effects analyzed were age of dam, sex of calf, contemporary group, fraction of Brahman (2 levels: 1 and 0.5), age of calf at record, and weaning age. At weaning, the mean PS was 2.68 ± 0.1, the mean EV was 2.41