26 CFR 1.148-3 - General arbitrage rebate rules.

Code of Federal Regulations, 2011 CFR

2011-04-01

... at the end of any period is determined using the economic accrual method and equals the value of that..., when added to the future value, as of the computation date, of previous rebate payments made for the... any date, the rebate amount for an issue is the excess of the future value, as of that date, of all...

Finite-size scaling study of the two-dimensional Blume-Capel model

NASA Astrophysics Data System (ADS)

Beale, Paul D.

1986-02-01

The phase diagram of the two-dimensional Blume-Capel model is investigated by using the technique of phenomenological finite-size scaling. The location of the tricritical point and the values of the critical and tricritical exponents are determined. The location of the tricritical point (Tt=0.610+/-0.005, Dt=1.9655+/-0.0010) is well outside the error bars for the value quoted in previous Monte Carlo simulations but in excellent agreement with more recent Monte Carlo renormalization-group results. The values of the critical and tricritical exponents, with the exception of the leading thermal tricritical exponent, are in excellent agreement with previous calculations, conjectured values, and Monte Carlo renormalization-group studies.

Administrative database code accuracy did not vary notably with changes in disease prevalence.

PubMed

van Walraven, Carl; English, Shane; Austin, Peter C

2016-11-01

Previous mathematical analyses of diagnostic tests based on the categorization of a continuous measure have found that test sensitivity and specificity varies significantly by disease prevalence. This study determined if the accuracy of diagnostic codes varied by disease prevalence. We used data from two previous studies in which the true status of renal disease and primary subarachnoid hemorrhage, respectively, had been determined. In multiple stratified random samples from the two previous studies having varying disease prevalence, we measured the accuracy of diagnostic codes for each disease using sensitivity, specificity, and positive and negative predictive value. Diagnostic code sensitivity and specificity did not change notably within clinically sensible disease prevalence. In contrast, positive and negative predictive values changed significantly with disease prevalence. Disease prevalence had no important influence on the sensitivity and specificity of diagnostic codes in administrative databases. Copyright © 2016 Elsevier Inc. All rights reserved.

Sphericity determination using resonant ultrasound spectroscopy

DOEpatents

Dixon, Raymond D.; Migliori, Albert; Visscher, William M.

1994-01-01

A method is provided for grading production quantities of spherical objects, such as roller balls for bearings. A resonant ultrasound spectrum (RUS) is generated for each spherical object and a set of degenerate sphere-resonance frequencies is identified. From the degenerate sphere-resonance frequencies and known relationships between degenerate sphere-resonance frequencies and Poisson's ratio, a Poisson's ratio can be determined, along with a "best" spherical diameter, to form spherical parameters for the sphere. From the RUS, fine-structure resonant frequency spectra are identified for each degenerate sphere-resonance frequency previously selected. From each fine-structure spectrum and associated sphere parameter values an asphericity value is determined. The asphericity value can then be compared with predetermined values to provide a measure for accepting or rejecting the sphere.

Sphericity determination using resonant ultrasound spectroscopy

DOEpatents

Dixon, R.D.; Migliori, A.; Visscher, W.M.

1994-10-18

A method is provided for grading production quantities of spherical objects, such as roller balls for bearings. A resonant ultrasound spectrum (RUS) is generated for each spherical object and a set of degenerate sphere-resonance frequencies is identified. From the degenerate sphere-resonance frequencies and known relationships between degenerate sphere-resonance frequencies and Poisson's ratio, a Poisson's ratio can be determined, along with a 'best' spherical diameter, to form spherical parameters for the sphere. From the RUS, fine-structure resonant frequency spectra are identified for each degenerate sphere-resonance frequency previously selected. From each fine-structure spectrum and associated sphere parameter values an asphericity value is determined. The asphericity value can then be compared with predetermined values to provide a measure for accepting or rejecting the sphere. 14 figs.

Method and System for Temporal Filtering in Video Compression Systems

NASA Technical Reports Server (NTRS)

Lu, Ligang; He, Drake; Jagmohan, Ashish; Sheinin, Vadim

2011-01-01

Three related innovations combine improved non-linear motion estimation, video coding, and video compression. The first system comprises a method in which side information is generated using an adaptive, non-linear motion model. This method enables extrapolating and interpolating a visual signal, including determining the first motion vector between the first pixel position in a first image to a second pixel position in a second image; determining a second motion vector between the second pixel position in the second image and a third pixel position in a third image; determining a third motion vector between the first pixel position in the first image and the second pixel position in the second image, the second pixel position in the second image, and the third pixel position in the third image using a non-linear model; and determining a position of the fourth pixel in a fourth image based upon the third motion vector. For the video compression element, the video encoder has low computational complexity and high compression efficiency. The disclosed system comprises a video encoder and a decoder. The encoder converts the source frame into a space-frequency representation, estimates the conditional statistics of at least one vector of space-frequency coefficients with similar frequencies, and is conditioned on previously encoded data. It estimates an encoding rate based on the conditional statistics and applies a Slepian-Wolf code with the computed encoding rate. The method for decoding includes generating a side-information vector of frequency coefficients based on previously decoded source data and encoder statistics and previous reconstructions of the source frequency vector. It also performs Slepian-Wolf decoding of a source frequency vector based on the generated side-information and the Slepian-Wolf code bits. The video coding element includes receiving a first reference frame having a first pixel value at a first pixel position, a second reference frame having a second pixel value at a second pixel position, and a third reference frame having a third pixel value at a third pixel position. It determines a first motion vector between the first pixel position and the second pixel position, a second motion vector between the second pixel position and the third pixel position, and a fourth pixel value for a fourth frame based upon a linear or nonlinear combination of the first pixel value, the second pixel value, and the third pixel value. A stationary filtering process determines the estimated pixel values. The parameters of the filter may be predetermined constants.

Decree-Law No. 199/88, 31 May 1988.

PubMed

1988-01-01

This Decree-Law establishes criteria for the determination of final compensation for expropriation or nationalization of land or agricultural capital. The lack of legal definition of criteria for the determination of such final compensation was a gap in recent Portuguese legislation on land reform. Although the holdings of many landlords and farmers had been nationalized or expropriated after 11 March 1975, the compensation obtained prior to the enactment of this Decree-Law was provisional and reflected outdated values. This Decree-Law closes this gap by establishing the criteria for the determination of final compensation with adjusted value. Under it, any farmer whose land or capital has been nationalized or expropriated since March 1975 may apply for final compensation, from which shall be deducted the value of any provisional compensation previously obtained and any property previously devolved as a "right of reserve" pursuant to pertinent legislation (see Law No. 109/88 of 26 September 1988 and Decree No. 44/88 of 14 December 1988). The final compensation shall be determined by administrative procedure in which the Ministry of Agriculture, Fisheries, and Food; the Ministry of Finance; and the applicant are represented. full text

A Boltzmann constant determination based on Johnson noise thermometry

NASA Astrophysics Data System (ADS)

Flowers-Jacobs, N. E.; Pollarolo, A.; Coakley, K. J.; Fox, A. E.; Rogalla, H.; Tew, W. L.; Benz, S. P.

2017-10-01

A value for the Boltzmann constant was measured electronically using an improved version of the Johnson Noise Thermometry (JNT) system at the National Institute of Standards and Technology (NIST), USA. This system is different from prior ones, including those from the 2011 determination at NIST and both 2015 and 2017 determinations at the National Institute of Metrology (NIM), China. As in all three previous determinations, the main contribution to the combined uncertainty is the statistical uncertainty in the noise measurement, which is mitigated by accumulating and integrating many weeks of cross-correlated measured data. The second major uncertainty contribution also still results from variations in the frequency response of the ratio of the measured spectral noise of the two noise sources, the sense resistor at the triple-point of water and the superconducting quantum voltage noise source. In this paper, we briefly describe the major differences between our JNT system and previous systems, in particular the input circuit and approach we used to match the frequency responses of the two noise sources. After analyzing and integrating 50 d of accumulated data, we determined a value: k~=1.380 642 9(69)× {{10}-23} J K-1 with a relative standard uncertainty of 5.0× {{10}-6} and relative offset -4.05× {{10}-6} from the CODATA 2014 recommended value.

SCS-CN parameter determination using rainfall-runoff data in heterogeneous watersheds. The two-CN system approach

NASA Astrophysics Data System (ADS)

Soulis, K. X.; Valiantzas, J. D.

2011-10-01

The Soil Conservation Service Curve Number (SCS-CN) approach is widely used as a simple method for predicting direct runoff volume for a given rainfall event. The CN values can be estimated by being selected from tables. However, it is more accurate to estimate the CN value from measured rainfall-runoff data (assumed available) in a watershed. Previous researchers indicated that the CN values calculated from measured rainfall-runoff data vary systematically with the rainfall depth. They suggested the determination of a single asymptotic CN value observed for very high rainfall depths to characterize the watersheds' runoff response. In this paper, the novel hypothesis that the observed correlation between the calculated CN value and the rainfall depth in a watershed reflects the effect of the inevitable presence of soil-cover complex spatial variability along watersheds is being tested. Based on this hypothesis, the simplified concept of a two-CN heterogeneous system is introduced to model the observed CN-rainfall variation by reducing the CN spatial variability into two classes. The behavior of the CN-rainfall function produced by the proposed two-CN system concept is approached theoretically, it is analyzed systematically, and it is found to be similar to the variation observed in natural watersheds. Synthetic data tests, natural watersheds examples, and detailed study of two natural experimental watersheds with known spatial heterogeneity characteristics were used to evaluate the method. The results indicate that the determination of CN values from rainfall runoff data using the proposed two-CN system approach provides reasonable accuracy and it over performs the previous original method based on the determination of a single asymptotic CN value. Although the suggested method increases the number of unknown parameters to three (instead of one), a clear physical reasoning for them is presented.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hess, Peter

An improved microscopic cleavage model, based on a Morse-type and Lennard-Jones-type interaction instead of the previously employed half-sine function, is used to determine the maximum cleavage strength for the brittle materials diamond, tungsten, molybdenum, silicon, GaAs, silica, and graphite. The results of both interaction potentials are in much better agreement with the theoretical strength values obtained by ab initio calculations for diamond, tungsten, molybdenum, and silicon than the previous model. Reasonable estimates of the intrinsic strength are presented for GaAs, silica, and graphite, where first principles values are not available.

Quantitative Comparison of Human Parainfluenza Virus Hemagglutinin-Neuraminidase Receptor Binding and Receptor Cleavage

PubMed Central

Tappert, Mary M.; Porterfield, J. Zachary; Mehta-D'Souza, Padmaja; Gulati, Shelly

2013-01-01

The human parainfluenza virus (hPIV) hemagglutinin-neuraminidase (HN) protein binds (H) oligosaccharide receptors that contain N-acetylneuraminic acid (Neu5Ac) and cleaves (N) Neu5Ac from these oligosaccharides. In order to determine if one of HN′s two functions is predominant, we measured the affinity of H for its ligands by a solid-phase binding assay with two glycoprotein substrates and by surface plasmon resonance with three monovalent glycans. We compared the dissociation constant (Kd) values from these experiments with previously determined Michaelis-Menten constants (Kms) for the enzyme activity. We found that glycoprotein substrates and monovalent glycans containing Neu5Acα2-3Galβ1-4GlcNAc bind HN with Kd values in the 10 to 100 μM range. Km values for HN were previously determined to be on the order of 1 mM (M. M. Tappert, D. F. Smith, and G. M. Air, J. Virol. 85:12146–12159, 2011). A Km value greater than the Kd value indicates that cleavage occurs faster than the dissociation of binding and will dominate under N-permissive conditions. We propose, therefore, that HN is a neuraminidase that can hold its substrate long enough to act as a binding protein. The N activity can therefore regulate binding by reducing virus-receptor interactions when the concentration of receptor is high. PMID:23740997

Statistical analysis of effective singular values in matrix rank determination

NASA Technical Reports Server (NTRS)

Konstantinides, Konstantinos; Yao, Kung

1988-01-01

A major problem in using SVD (singular-value decomposition) as a tool in determining the effective rank of a perturbed matrix is that of distinguishing between significantly small and significantly large singular values to the end, conference regions are derived for the perturbed singular values of matrices with noisy observation data. The analysis is based on the theories of perturbations of singular values and statistical significance test. Threshold bounds for perturbation due to finite-precision and i.i.d. random models are evaluated. In random models, the threshold bounds depend on the dimension of the matrix, the noisy variance, and predefined statistical level of significance. Results applied to the problem of determining the effective order of a linear autoregressive system from the approximate rank of a sample autocorrelation matrix are considered. Various numerical examples illustrating the usefulness of these bounds and comparisons to other previously known approaches are given.

International Christian Schoolteachers' Traits, Characteristics, and Qualities Valued by Third Culture Kids

ERIC Educational Resources Information Center

Linton, Dale B.

2015-01-01

In this qualitative grounded theory study, 24 participants, referred to as "third culture kids" (or TCKs), ages 18-30 years, who had previously attended international Christian schools were interviewed to determine the dispositions they valued in their teachers. Incorporating principles of grounded theory, a series of rigorous steps were…

Determination of zircon/melt trace element partition coefficients from SIMS analysis of melt inclusions in zircon

NASA Astrophysics Data System (ADS)

Thomas, J. B.; Bodnar, R. J.; Shimizu, N.; Sinha, A. K.

2002-09-01

Partition coefficients ( zircon/meltD M) for rare earth elements (REE) (La, Ce, Nd, Sm, Dy, Er and Yb) and other trace elements (Ba, Rb, B, Sr, Ti, Y and Nb) between zircon and melt have been calculated from secondary ion mass spectrometric (SIMS) analyses of zircon/melt inclusion pairs. The melt inclusion-mineral (MIM) technique shows that D REE increase in compatibility with increasing atomic number, similar to results of previous studies. However, D REE determined using the MIM technique are, in general, lower than previously reported values. Calculated D REE indicate that light REE with atomic numbers less than Sm are incompatible in zircon and become more incompatible with decreasing atomic number. This behavior is in contrast to most previously published results which indicate D > 1 and define a flat partitioning pattern for elements from La through Sm. The partition coefficients for the heavy REE determined using the MIM technique are lower than previously published results by factors of ≈15 to 20 but follow a similar trend. These differences are thought to reflect the effects of mineral and/or glass contaminants in samples from earlier studies which employed bulk analysis techniques. D REE determined using the MIM technique agree well with values predicted using the equations of Brice (1975), which are based on the size and elasticity of crystallographic sites. The presence of Ce 4+ in the melt results in elevated D Ce compared to neighboring REE due to the similar valence and size of Ce 4+ and Zr 4+. Predicted zircon/meltD values for Ce 4+ and Ce 3+ indicate that the Ce 4+/Ce 3+ ratios of the melt ranged from about 10 -3 to 10 -2. Partition coefficients for other trace elements determined in this study increase in compatibility in the order Ba < Rb < B < Sr < Ti < Y < Nb, with Ba, Rb, B and Sr showing incompatible behavior (D M < 1.0), and Ti, Y and Nb showing compatible behavior (D M > 1.0). The effect of partition coefficients on melt evolution during petrogenetic modeling was examined using partition coefficients determined in this study and compared to trends obtained using published partition coefficients. The lower D REE determined in this study result in smaller REE bulk distribution coefficients, for a given mineral assemblage, compared to those calculated using previously reported values. As an example, fractional crystallization of an assemblage composed of 35% hornblende, 64.5% plagioclase and 0.5% zircon produces a melt that becomes increasingly more enriched in Yb using the D Yb from this study. Using D Yb from Fujimaki (1986) results in a melt that becomes progressively depleted in Yb during crystallization.

Determination of kinetic parameters for 123-I thyroid uptake in healthy Japanese

NASA Astrophysics Data System (ADS)

Kusuhara, Hiroyuki; Maeda, Kazuya

2017-09-01

The purpose of this study was to compare the kinetic parameters for iodide thyroid accumulation in Japanese today with previously reported values. We determined the thyroid uptake of 123-I at 24 hours after the oral administration in healthy male Japanese without any diet restriction. The mean value was 16.1±5.4%, which was similar or rather lower than those previously reported in Japan (1958-1972). Kinetic model analysis was conducted to obtain the clearance for thyroid uptake from the blood circulation. The thyroid uptake clearance of 123-I was 0.540±0.073 ml/min, which was almost similar to those reported previously. There is no obvious difference in the thyroid uptake for 24 hours, and kinetic parameters in healthy Japanese for these 50 years. The fraction of distributed to the thyroid gland is lower than the ICRP reference man, and such difference must be taken into consideration to estimate the radiation exposure upon Fukushima accident in Japan.

Experimental determination of the turbulence in a liquid rocket combustion chamber

NASA Technical Reports Server (NTRS)

Hara, J.; Smith, L. O.; Partus, F. P.

1972-01-01

The intensity of turbulence and the Lagrangian correlation coefficient for a liquid rocket combustion chamber were determined experimentally using the tracer gas diffusion method. The results indicate that the turbulent diffusion process can be adequately modeled by the one-dimensional Taylor theory; however, the numerical values show significant disagreement with previously accepted values. The intensity of turbulence is higher by a factor of about two, while the Lagrangian correlation coefficient which was assumed to be unity in the past is much less than unity.

Comparing quantitative values of two generations of laser-assisted indocyanine green dye angiography systems: can we predict necrosis?

PubMed

Phillips, Brett T; Fourman, Mitchell S; Rivara, Andrew; Dagum, Alexander B; Huston, Tara L; Ganz, Jason C; Bui, Duc T; Khan, Sami U

2014-01-01

Several devices exist today to assist the intraoperative determination of skin flap perfusion. Laser-Assisted Indocyanine Green Dye Angiography (LAICGA) has been shown to accurately predict mastectomy skin flap necrosis using quantitative perfusion values. The laser properties of the latest LAICGA device (SPY Elite) differ significantly from its predecessor system (SPY 2001), preventing direct translation of previous published data. The purpose of this study was to establish a mathematical relationship of perfusion values between these 2 devices. Breast reconstruction patients were prospectively enrolled into a clinical trial where skin flap evaluation and excision was based on quantitative SPY Q values previously established in the literature. Initial study patients underwent mastectomy skin flap evaluation using both SPY systems simultaneously. Absolute perfusion unit (APU) values at identical locations on the breast were then compared graphically. 210 data points were identified on the same patients (n = 4) using both SPY systems. A linear relationship (y = 2.9883x + 12.726) was identified with a high level or correlation (R(2) = 0.744). Previously published values using SPY 2001 (APU 3.7) provided a value of 23.8 APU on the SPY Elite. In addition, postoperative necrosis in these patients correlated to regions of skin identified with the SPY Elite with APU less than 23.8. Intraoperative comparison of LAICGA systems has provided direct correlation of perfusion values predictive of necrosis that were previously established in the literature. An APU value of 3.7 from the SPY 2001 correlates to a SPY Elite APU value of 23.8.

Comparing Quantitative Values of Two Generations of Laser-Assisted Indocyanine Green Dye Angiography Systems: Can We Predict Necrosis?

PubMed Central

Fourman, Mitchell S.; Rivara, Andrew; Dagum, Alexander B.; Huston, Tara L.; Ganz, Jason C.; Bui, Duc T.; Khan, Sami U.

2014-01-01

Objective: Several devices exist today to assist the intraoperative determination of skin flap perfusion. Laser-Assisted Indocyanine Green Dye Angiography (LAICGA) has been shown to accurately predict mastectomy skin flap necrosis using quantitative perfusion values. The laser properties of the latest LAICGA device (SPY Elite) differ significantly from its predecessor system (SPY 2001), preventing direct translation of previous published data. The purpose of this study was to establish a mathematical relationship of perfusion values between these 2 devices. Methods: Breast reconstruction patients were prospectively enrolled into a clinical trial where skin flap evaluation and excision was based on quantitative SPY Q values previously established in the literature. Initial study patients underwent mastectomy skin flap evaluation using both SPY systems simultaneously. Absolute perfusion unit (APU) values at identical locations on the breast were then compared graphically. Results: 210 data points were identified on the same patients (n = 4) using both SPY systems. A linear relationship (y = 2.9883x + 12.726) was identified with a high level or correlation (R2 = 0.744). Previously published values using SPY 2001 (APU 3.7) provided a value of 23.8 APU on the SPY Elite. In addition, postoperative necrosis in these patients correlated to regions of skin identified with the SPY Elite with APU less than 23.8. Conclusion: Intraoperative comparison of LAICGA systems has provided direct correlation of perfusion values predictive of necrosis that were previously established in the literature. An APU value of 3.7 from the SPY 2001 correlates to a SPY Elite APU value of 23.8. PMID:25525483

System for determining the type of nuclear radiation from detector output pulse shape

DOEpatents

Miller, William H.; Berliner, Ronald R.

1994-01-01

A radiation detection system determines the type of nuclear radiation received in a detector by producing a correlation value representative of the statistical cross correlation between the shape of the detector signal and pulse shape data previously stored in memory and characteristic of respective types of radiation. The correlation value is indicative of the type of radiation. The energy of the radiation is determined from the detector signal and is used to produce a spectrum of radiation energies according to radiation type for indicating the nature of the material producing the radiation.

System for determining the type of nuclear radiation from detector output pulse shape

DOEpatents

Miller, W.H.; Berliner, R.R.

1994-09-13

A radiation detection system determines the type of nuclear radiation received in a detector by producing a correlation value representative of the statistical cross correlation between the shape of the detector signal and pulse shape data previously stored in memory and characteristic of respective types of radiation. The correlation value is indicative of the type of radiation. The energy of the radiation is determined from the detector signal and is used to produce a spectrum of radiation energies according to radiation type for indicating the nature of the material producing the radiation. 2 figs.

Thermodynamic characterization of tandem mismatches found in naturally occurring RNA

PubMed Central

Christiansen, Martha E.; Znosko, Brent M.

2009-01-01

Although all sequence symmetric tandem mismatches and some sequence asymmetric tandem mismatches have been thermodynamically characterized and a model has been proposed to predict the stability of previously unmeasured sequence asymmetric tandem mismatches [Christiansen,M.E. and Znosko,B.M. (2008) Biochemistry, 47, 4329–4336], experimental thermodynamic data for frequently occurring tandem mismatches is lacking. Since experimental data is preferred over a predictive model, the thermodynamic parameters for 25 frequently occurring tandem mismatches were determined. These new experimental values, on average, are 1.0 kcal/mol different from the values predicted for these mismatches using the previous model. The data for the sequence asymmetric tandem mismatches reported here were then combined with the data for 72 sequence asymmetric tandem mismatches that were published previously, and the parameters used to predict the thermodynamics of previously unmeasured sequence asymmetric tandem mismatches were updated. The average absolute difference between the measured values and the values predicted using these updated parameters is 0.5 kcal/mol. This updated model improves the prediction for tandem mismatches that were predicted rather poorly by the previous model. This new experimental data and updated predictive model allow for more accurate calculations of the free energy of RNA duplexes containing tandem mismatches, and, furthermore, should allow for improved prediction of secondary structure from sequence. PMID:19509311

Enzymatic fractionation of SAA-pretreated barley straw for production of fuel ethanol and astaxanthin as a value-added co-product

USDA-ARS?s Scientific Manuscript database

Barley straw was used to demonstrate a process for production of ethanol and astaxanthin as a value-added co-product. Barley straw was pretreated by soaking in aqueous ammonia (SAA) using the previously determined optimum conditions. The pretreated barley straw was first hydrolyzed with Accellerase®...

Rotational Velocity Determinations for 118 δ Scuti Variables

NASA Astrophysics Data System (ADS)

Bush, Tabitha C.; Hintz, Eric G.

2008-09-01

A calibration method is presented for the determination of projected rotational velocities of 118 δ Scuti variables from FWHM measurements of metal lines near 4500 Å. The calibration relation used was derived from measurements of 29 stars. Of the 44 stars brighter than 8th magnitude and north of -1° declination which did not have values in the Rodríguez catalog (Rodríguez, E., López González, M. J., & López de Coca, P. 2000, A&AS, 144, 469) we present values for 38. In addition, we present new projected rotational velocity, vsin i, values for 10 stars south of -1° or fainter than 8th magnitude for a total of 48 vsin i values for stars with no previously published values.

Lipophilicity assessment of basic drugs (log P(o/w) determination) by a chromatographic method.

PubMed

Pallicer, Juan M; Sales, Joaquim; Rosés, Martí; Ràfols, Clara; Bosch, Elisabeth

2011-09-16

A previously reported chromatographic method to determine the 1-octanol/water partition coefficient (log P(o/w)) of organic compounds is used to estimate the hydrophobicity of bases, mainly commercial drugs with diverse chemical nature and pK(a) values higher than 9. For that reason, mobile phases buffered at high pH to avoid the ionization of the solutes and three different columns (Phenomenex Gemini NX, Waters XTerra RP-18 and Waters XTerra MS C(18)) with appropriate alkaline-resistant stationary phases have been used. Non-ionizable substances studied in previous works were also included in the set of compounds to evaluate the consistency of the method. The results showed that all the columns provide good estimations of the log P(o/w) for most of the compounds included in this study. The Gemini NX column has been selected to calculate log P(o/w) values of the set of studied drugs, and really good correlations between the determined log P(o/w) values and those considered as reference were obtained, proving the ability of the procedure for the lipophilicity assessment of bioactive compounds with very different structures and functionalities. Copyright © 2011 Elsevier B.V. All rights reserved.

Factors influencing the robustness of P-value measurements in CT texture prognosis studies

NASA Astrophysics Data System (ADS)

McQuaid, Sarah; Scuffham, James; Alobaidli, Sheaka; Prakash, Vineet; Ezhil, Veni; Nisbet, Andrew; South, Christopher; Evans, Philip

2017-07-01

Several studies have recently reported on the value of CT texture analysis in predicting survival, although the topic remains controversial, with further validation needed in order to consolidate the evidence base. The aim of this study was to investigate the effect of varying the input parameters in the Kaplan-Meier analysis, to determine whether the resulting P-value can be considered to be a robust indicator of the parameter’s prognostic potential. A retrospective analysis of the CT-based normalised entropy of 51 patients with lung cancer was performed and overall survival data for these patients were collected. A normalised entropy cut-off was chosen to split the patient cohort into two groups and log-rank testing was performed to assess the survival difference of the two groups. This was repeated for varying normalised entropy cut-offs and varying follow-up periods. Our findings were also compared with previously published results to assess robustness of this parameter in a multi-centre patient cohort. The P-value was found to be highly sensitive to the choice of cut-off value, with small changes in cut-off producing substantial changes in P. The P-value was also sensitive to follow-up period, with particularly noisy results at short follow-up periods. Using matched conditions to previously published results, a P-value of 0.162 was obtained. Survival analysis results can be highly sensitive to the choice in texture cut-off value in dichotomising patients, which should be taken into account when performing such studies to avoid reporting false positive results. Short follow-up periods also produce unstable results and should therefore be avoided to ensure the results produced are reproducible. Previously published findings that indicated the prognostic value of normalised entropy were not replicated here, but further studies with larger patient numbers would be required to determine the cause of the different outcomes.

Small-volume potentiometric titrations: EPR investigations of Fe-S cluster N2 in mitochondrial complex I.

PubMed

Wright, John J; Salvadori, Enrico; Bridges, Hannah R; Hirst, Judy; Roessler, Maxie M

2016-09-01

EPR-based potentiometric titrations are a well-established method for determining the reduction potentials of cofactors in large and complex proteins with at least one EPR-active state. However, such titrations require large amounts of protein. Here, we report a new method that requires an order of magnitude less protein than previously described methods, and that provides EPR samples suitable for measurements at both X- and Q-band microwave frequencies. We demonstrate our method by determining the reduction potential of the terminal [4Fe-4S] cluster (N2) in the intramolecular electron-transfer relay in mammalian respiratory complex I. The value determined by our method, E m7 =-158mV, is precise, reproducible, and consistent with previously reported values. Our small-volume potentiometric titration method will facilitate detailed investigations of EPR-active centres in non-abundant and refractory proteins that can only be prepared in small quantities. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

SCS-CN parameter determination using rainfall-runoff data in heterogeneous watersheds - the two-CN system approach

NASA Astrophysics Data System (ADS)

Soulis, K. X.; Valiantzas, J. D.

2012-03-01

The Soil Conservation Service Curve Number (SCS-CN) approach is widely used as a simple method for predicting direct runoff volume for a given rainfall event. The CN parameter values corresponding to various soil, land cover, and land management conditions can be selected from tables, but it is preferable to estimate the CN value from measured rainfall-runoff data if available. However, previous researchers indicated that the CN values calculated from measured rainfall-runoff data vary systematically with the rainfall depth. Hence, they suggested the determination of a single asymptotic CN value observed for very high rainfall depths to characterize the watersheds' runoff response. In this paper, the hypothesis that the observed correlation between the calculated CN value and the rainfall depth in a watershed reflects the effect of soils and land cover spatial variability on its hydrologic response is being tested. Based on this hypothesis, the simplified concept of a two-CN heterogeneous system is introduced to model the observed CN-rainfall variation by reducing the CN spatial variability into two classes. The behaviour of the CN-rainfall function produced by the simplified two-CN system is approached theoretically, it is analysed systematically, and it is found to be similar to the variation observed in natural watersheds. Synthetic data tests, natural watersheds examples, and detailed study of two natural experimental watersheds with known spatial heterogeneity characteristics were used to evaluate the method. The results indicate that the determination of CN values from rainfall runoff data using the proposed two-CN system approach provides reasonable accuracy and it over performs the previous methods based on the determination of a single asymptotic CN value. Although the suggested method increases the number of unknown parameters to three (instead of one), a clear physical reasoning for them is presented.

Determination of the Gravitational Constant with a Beam Balance

NASA Astrophysics Data System (ADS)

Schlamminger, St.; Holzschuh, E.; Kündig, W.

2002-09-01

The Newtonian gravitational constant G was determined by means of a novel beam-balance experiment with an accuracy comparable to that of the most precise torsion-balance experiments. The gravitational force of two stainless steel tanks filled with 13 521kg mercury on 1.1kg test masses was measured using a commercial mass comparator. A careful analysis of the data and the experimental error yields G=6.674 07(22)×10-11 m3 kg-1 s-2. This value is in excellent agreement with most values previously obtained with different methods.

On determining the most appropriate test cut-off value: the case of tests with continuous results

PubMed Central

Habibzadeh, Parham; Yadollahie, Mahboobeh

2016-01-01

There are several criteria for determination of the most appropriate cut-off value in a diagnostic test with continuous results. Mostly based on receiver operating characteristic (ROC) analysis, there are various methods to determine the test cut-off value. The most common criteria are the point on ROC curve where the sensitivity and specificity of the test are equal; the point on the curve with minimum distance from the left-upper corner of the unit square; and the point where the Youden’s index is maximum. There are also methods mainly based on Bayesian decision analysis. Herein, we show that a proposed method that maximizes the weighted number needed to misdiagnose, an index of diagnostic test effectiveness we previously proposed, is the most appropriate technique compared to the aforementioned ones. For determination of the cut-off value, we need to know the pretest probability of the disease of interest as well as the costs incurred by misdiagnosis. This means that even for a certain diagnostic test, the cut-off value is not universal and should be determined for each region and for each disease condition. PMID:27812299

78 FR 4919 - Self-Regulatory Organizations; NYSE Arca, Inc.; Order Instituting Proceedings To Determine...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-23

... respective barrier price, a cash settlement payment in an amount equal to the difference between the strike... options sold, then decremented by cash settlements of any down-and-in put options expiring in-the-money... end of the previous quarter; Option Value is the settlement value of each of the 20 down-and-in put...

Application of Artificial Neural Network to Optical Fluid Analyzer

NASA Astrophysics Data System (ADS)

Kimura, Makoto; Nishida, Katsuhiko

1994-04-01

A three-layer artificial neural network has been applied to the presentation of optical fluid analyzer (OFA) raw data, and the accuracy of oil fraction determination has been significantly improved compared to previous approaches. To apply the artificial neural network approach to solving a problem, the first step is training to determine the appropriate weight set for calculating the target values. This involves using a series of data sets (each comprising a set of input values and an associated set of output values that the artificial neural network is required to determine) to tune artificial neural network weighting parameters so that the output of the neural network to the given set of input values is as close as possible to the required output. The physical model used to generate the series of learning data sets was the effective flow stream model, developed for OFA data presentation. The effectiveness of the training was verified by reprocessing the same input data as were used to determine the weighting parameters and then by comparing the results of the artificial neural network to the expected output values. The standard deviation of the expected and obtained values was approximately 10% (two sigma).

A Framework for Assessing the Value of Investments in Nonclinical Prevention

PubMed Central

Roehrig, Charles; Russo, Pamela

2015-01-01

We present a high-level framework to show the process by which an investment in primary prevention produces value. We define primary prevention broadly to include investments in any of the determinants of health. Although it builds on previously developed frameworks, ours incorporates several additional features. It distinguishes direct and upstream determinants of health, a distinction that can help identify, describe, and track the impact of a policy or program on health and health care costs. It recognizes multiple dimensions of value, including the need to establish the nonhealth value of investments whose objectives are not limited to improvements in health (and whose costs should not be attributed solely to the health benefits). Finally, it emphasizes the need to describe value from the perspectives of the multiple stakeholders that can influence such investments. PMID:26652216

A Framework for Assessing the Value of Investments in Nonclinical Prevention.

PubMed

Miller, George; Roehrig, Charles; Russo, Pamela

2015-12-10

We present a high-level framework to show the process by which an investment in primary prevention produces value. We define primary prevention broadly to include investments in any of the determinants of health. Although it builds on previously developed frameworks, ours incorporates several additional features. It distinguishes direct and upstream determinants of health, a distinction that can help identify, describe, and track the impact of a policy or program on health and health care costs. It recognizes multiple dimensions of value, including the need to establish the nonhealth value of investments whose objectives are not limited to improvements in health (and whose costs should not be attributed solely to the health benefits). Finally, it emphasizes the need to describe value from the perspectives of the multiple stakeholders that can influence such investments.

The Lateral Stability of Equal-flanged Aluminum-alloy I-beams Subjected to Pure Bending

NASA Technical Reports Server (NTRS)

Dumont, C; Hill, H N

1940-01-01

Equal-flange beams of a special extruded I-section of 27ST aluminum alloy were tested in pure bending. Complete end fixity was not attained. Loading was continued until a definite maximum value had been reached. Tensile tests were made on specimens cut from the flanges and the web of each beam. Compressive stress-strain characteristics were determined by pack compression tests on specimens cut from the flanges. Values computed from an equation previously suggested by one of the authors for the critical stress at which such beams become unstable were found to be in good agreement with values computed from experimentally determined critically bending moments.

Nucleophilic Participation in the Solvolyses of (Arylthio)methyl Chlorides and Derivatives: Application of Simple and Extended Forms of the Grunwald-Winstein Equations

PubMed Central

Kevill, Dennis N.; Park, Young Hoon; Park, Byoung-Chun; D’Souza, Malcolm J.

2012-01-01

The specific rates of solvolysis of chloromethyl phenyl sulfide [(phenylthio)methyl chloride] and its p-chloro-derivative have been determined at 0.0 °C in a wide range of hydroxylic solvents, including several containing a fluroalcohol. Treatment in terms of a two-term Grunwald-Winstein equation, incorporating terms based on solvent ionizing power (YCl) and solvent nucleophilicity (NT) suggest a mechanism similar to that for the solvolyses of tert-butyl chloride, involving in the rate-determining step a nucleophilic solvation of the incipient carbocation in an ionization process. A previous suggestion, that a third-term governed by the aromatic ring parameter (I) is required, is shown both for the new and for the previously studied related substrates to be an artifact, resulting from an appreciable degree of multicollinearity between I values and a linear combination of NT and YCl values. PMID:22711999

Accounting for between-study variation in incremental net benefit in value of information methodology.

PubMed

Willan, Andrew R; Eckermann, Simon

2012-10-01

Previous applications of value of information methods for determining optimal sample size in randomized clinical trials have assumed no between-study variation in mean incremental net benefit. By adopting a hierarchical model, we provide a solution for determining optimal sample size with this assumption relaxed. The solution is illustrated with two examples from the literature. Expected net gain increases with increasing between-study variation, reflecting the increased uncertainty in incremental net benefit and reduced extent to which data are borrowed from previous evidence. Hence, a trial can become optimal where current evidence is sufficient assuming no between-study variation. However, despite the expected net gain increasing, the optimal sample size in the illustrated examples is relatively insensitive to the amount of between-study variation. Further percentage losses in expected net gain were small even when choosing sample sizes that reflected widely different between-study variation. Copyright © 2011 John Wiley & Sons, Ltd.

Microcomputer Assisted Interpretative Reporting of Sequential Creatine Kinase (CK) and Lactate Dehydrogenase (LDH) Isoenzyme Determination

PubMed Central

Talamo, Thomas S.; Losos, Frank J.; Mercer, Donald W.

1984-01-01

We have developed a microcomputer based system for interpretative reporting of creatine kinase (CK) and lactate dehydrogenase (LDH) isoenzyme studies. Patient demographic data and test results (total CK, CK-MB, LD-1, and LD-2) are entered manually through the keyboard. The test results are compared with normal range values and an interpretative report is generated. This report consists of all pertinent demographic information with a graphic display of up to 12 previous CK and LDH isoenzyme determinations. Diagnostic interpretative statements are printed beneath the graphic display following analysis of previously entered test results. The combination of graphic data display and interpretations based on analysis of up to 12 previous specimens provides useful and accurate information to the cardiologist.

Determination of Global Stability of the Slosh Motion in a Spacecraft via Num Erical Experiment

NASA Astrophysics Data System (ADS)

Kang, Ja-Young

2003-12-01

The global stability of the attitude motion of a spin-stabilized space vehicle is investigated by performing numerical experiment. In the previous study, a stationary solution and a particular resonant condition for a given model were found by using analytical method but failed to represent the system stability over parameter values near and off the stationary points. Accordingly, as an extension of the previous work, this study performs numerical experiment to investigate the stability of the system across the parameter space and determines stable and unstable regions of the design parameters of the system.

Electron electric dipole moment and hyperfine interaction constants for ThO

NASA Astrophysics Data System (ADS)

Fleig, Timo; Nayak, Malaya K.

2014-06-01

A recently implemented relativistic four-component configuration interaction approach to study P- and T-odd interaction constants in atoms and molecules is employed to determine the electron electric dipole moment effective electric field in the Ω=1 first excited state of the ThO molecule. We obtain a value of Eeff=75.2GV/cm with an estimated error bar of 3% and 10% smaller than a previously reported result (Skripnikov et al., 2013). Using the same wavefunction model we obtain an excitation energy of TvΩ=1=5410 (cm), in accord with the experimental value within 2%. In addition, we report the implementation of the magnetic hyperfine interaction constant A|| as an expectation value, resulting in A||=-1339 (MHz) for the Ω=1 state in ThO. The smaller effective electric field increases the previously determined upper bound (Baron et al., 2014) on the electron electric dipole moment to |de|<9.7×10-29e cm and thus mildly mitigates constraints to possible extensions of the Standard Model of particle physics.

Efficacy ranking of triterpenoids as inducers of a cytoprotective enzyme and as inhibitors of a cellular inflammatory response via their electron affinity and their electrophilicity index

PubMed Central

Bensasson, René V.; Zoete, Vincent; Berthier, Gaston; Talalay, Paul; Dinkova-Kostova, Albena T.

2010-01-01

Electron affinity (EA) and electrophilicity index (ω) of 16 synthetic triterpenoids (TP), previously identified as inducers of cytoprotective enzymes and as inhibitors of cellular inflammatory responses, have been calculated by the molecular orbital method. Linear correlations were obtained by plotting the values of EA, as well as those of ω versus (i) the potencies of induction of NAD(P)H quinone reductase (NQO1, EC 1.6.99.2), a cytoprotective enzyme, expressed via the concentration of TP required to double the specific activity of NQO1 (CD value) and (ii) the values of their anti-inflammatory activity expressed via the IC-50 of TP for suppression of upregulation of inducible nitric oxide synthase (iNOS, EC 1.14.13.39), both previously experimentally determined. The observed correlations demonstrate quantitatively for a series of triterpenoids that their electrophilicity is a major factor determining their potency as inducers of the cytoprotective phase 2 response and as inhibitors of inflammatory processes. PMID:20433811

Paleointensity determination on Neoarchaean dikes within the Vodlozerskii terrane of the Karelian craton

NASA Astrophysics Data System (ADS)

Shcherbakova, V. V.; Lubnina, N. V.; Shcherbakov, V. P.; Zhidkov, G. V.; Tsel'movich, V. A.

2017-09-01

The results of paleomagnetic studies and paleointensity determinations from two Neoarchaean Shala dikes with an age of 2504 Ma, located within the Vodlozerskii terrane of the Karelian craton, are presented. The characteristic components of primary magnetization with shallow inclinations I = -5.7 and 1.9 are revealed; the reliability of the determinations is supported by two contact tests. High paleointensity values are obtained by the Thellier-Coe and Wilson techniques. The calculated values of the virtual dipole moment (11.5 and 13.8) × 1022 A m2 are noticeably higher than the present value of 7.8 × 1022 A m2. Our results, in combination with the previous data presented in the world database, support the hypothesized existence of a period of high paleointensity in the Late Archaean-Early Proterozoic.

Determination of Dimensionless Attenuation Coefficient in Shaped Resonators

NASA Technical Reports Server (NTRS)

Daniels, C.; Steinetz, B.; Finkbeiner, J.; Raman, G.; Li, X.

2003-01-01

The value of dimensionless attenuation coefficient is an important factor when numerically predicting high-amplitude acoustic waves in shaped resonators. Both the magnitude of the pressure waveform and the quality factor rely heavily on this dimensionless parameter. Previous authors have stated the values used, but have not completely explained their methods. This work fully describes the methodology used to determine this important parameter. Over a range of frequencies encompassing the fundamental resonance, the pressure waves were experimentally measured at each end of the shaped resonators. At the corresponding dimensionless acceleration, the numerical code modeled the acoustic waveforms generated in the resonator using various dimensionless attenuation coefficients. The dimensionless attenuation coefficient that most closely matched the pressure amplitudes and quality factors of the experimental and numerical results was determined to be the value to be used in subsequent studies.

Determination of the Avogadro constant by the XRCD method using a 28Si-enriched sphere

NASA Astrophysics Data System (ADS)

Kuramoto, Naoki; Mizushima, Shigeki; Zhang, Lulu; Fujita, Kazuaki; Azuma, Yasushi; Kurokawa, Akira; Okubo, Sho; Inaba, Hajime; Fujii, Kenichi

2017-10-01

To determine the Avogadro constant N A by the x-ray crystal density method, the density of a 28Si-enriched crystal was determined by absolute measurements of the mass and volume of a 1 kg sphere manufactured from the crystal. The mass and volume were determined by an optical interferometer and a vacuum mass comparator, respectively. The sphere surface was characterized by x-ray photoelectron spectroscopy and spectroscopic ellipsometry to derive the mass and volume of the Si core of the sphere excluding the surface layers. From the mass and volume, the density of the Si core was determined with a relative standard uncertainty of 2.3  ×  10-8. By combining the Si core density with the lattice constant and the molar mass of the sphere reported by the International Avogadro Coordination (IAC) project in 2015, a new value of 6.022 140 84(15)  ×  1023 mol-1 was obtained for N A with a relative standard uncertainty of 2.4  ×  10-8. To make the N A value determined in this work usable for a future adjustment of the fundamental constants by the CODATA Task Group on Fundamental Constants, the correlation of the new N A value with the N A values determined in our previous works was examined. The correlation coefficients with the values of N A determined by IAC in 2011 and 2015 were estimated to be 0.07 and 0.28, respectively. The correlation of the new N A value with the N A value determined by IAC in 2017 using a different 28Si-enriched crystal was also examined, and the correlation coefficient was estimated to be 0.21.

Comparison study of two procedures for the determination of emamectin benzoate in medicated fish feed.

PubMed

Farer, Leslie J; Hayes, John M

2005-01-01

A new method has been developed for the determination of emamectin benzoate in fish feed. The method uses a wet extraction, cleanup by solid-phase extraction, and quantitation and separation by liquid chromatography (LC). In this paper, we compare the performance of this method with that of a previously reported LC assay for the determination of emamectin benzoate in fish feed. Although similar to the previous method, the new procedure uses a different sample pretreatment, wet extraction, and quantitation method. The performance of the new method was compared with that of the previously reported method by analyses of 22 medicated feed samples from various commercial sources. A comparison of the results presented here reveals slightly lower assay values obtained with the new method. Although a paired sample t-test indicates the difference in results is significant, this difference is within the method precision of either procedure.

SPECTROSCOPIC ORBITS FOR 15 LATE-TYPE STARS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Willmarth, Daryl W.; Abt, Helmut A.; Fekel, Francis C.

2016-08-01

Spectroscopic orbital elements are determined for 15 stars with periods from 8 to 6528 days with six orbits computed for the first time. Improved astrometric orbits are computed for two stars and one new orbit is derived. Visual orbits were previously determined for four stars, four stars are members of multiple systems, and five stars have Hipparcos “G” designations or have been resolved by speckle interferometry. For the nine binaries with previous spectroscopic orbits, we determine improved or comparable elements. For HD 28271 and HD 200790, our spectroscopic results support the conclusions of previous authors that the large values of their massmore » functions and lack of detectable secondary spectrum argue for the secondary in each case being a pair of low-mass dwarfs. The orbits given here may be useful in combination with future interferometric and Gaia satellite observations.« less

Rotational Velocity Determinations for 118 δ Scuti Variables

NASA Astrophysics Data System (ADS)

Bush, Tabitha C.; Hintz, E. G.

2009-01-01

We present a calibration method used for the determination of projected rotational velocities (vsin i) of 118 δ Scuti variables from FWHM measurements of metal lines near 4500 Å. The calibration relation used was derived from measurements of 29 stars. Of the 44 stars brighter than 8th magnitude and north of -1° declination which did not have values in the Rodríguez catalog (Rodríguez, E., López González, M. J., & López de Coca, P. 2000, A&AS, 144, 469), we present values for 38. In addition, we present new vsin i values for 10 stars south of -1° or fainter than 8th magnitude for a total of 48 vsin i values for stars with no previously published values. We acknowledge the Dominion Astrophysical Observatory for making available the 1.2-m and 1.8-m telescopes to aid in this research.

Experimental Determination of pK[subscript a] Values by Use of NMR Chemical Shifts, Revisited

ERIC Educational Resources Information Center

Gift, Alan D.; Stewart, Sarah M.; Bokashanga, Patrick Kwete

2012-01-01

This laboratory experiment, using proton NMR spectroscopy to determine the dissociation constant for heterocyclic bases, has been modified from a previously described experiment. A solution of a substituted pyridine is prepared using deuterium oxide (D[subscript 2]O) as the solvent. The pH of the solution is adjusted and proton NMR spectra are…

Development of unauthorized airborne emission source identification procedure

NASA Astrophysics Data System (ADS)

Shtripling, L. O.; Bazhenov, V. V.; Varakina, N. S.; Kupriyanova, N. P.

2018-01-01

The paper presents the procedure for searching sources of unauthorized airborne emissions. To make reasonable regulation decisions on airborne pollutant emissions and to ensure the environmental safety of population, the procedure provides for the determination of a pollutant mass emission value from the source being the cause of high pollution level and the search of a previously unrecognized contamination source in a specified area. To determine the true value of mass emission from the source, the minimum of the mean-root-square mismatch criterion between the computed and measured pollutant concentration in the given location is used.

Precision measurement of the electromagnetic dipole strengths in Be11

NASA Astrophysics Data System (ADS)

Kwan, E.; Wu, C. Y.; Summers, N. C.; Hackman, G.; Drake, T. E.; Andreoiu, C.; Ashley, R.; Ball, G. C.; Bender, P. C.; Boston, A. J.; Boston, H. C.; Chester, A.; Close, A.; Cline, D.; Cross, D. S.; Dunlop, R.; Finlay, A.; Garnsworthy, A. B.; Hayes, A. B.; Laffoley, A. T.; Nano, T.; Navrátil, P.; Pearson, C. J.; Pore, J.; Quaglioni, S.; Svensson, C. E.; Starosta, K.; Thompson, I. J.; Voss, P.; Williams, S. J.; Wang, Z. M.

2014-05-01

The electromagnetic dipole strength in Be11 between the bound states has been measured using low-energy projectile Coulomb excitation at bombarding energies of 1.73 and 2.09 MeV/nucleon on a Pt196 target. An electric dipole transition probability B(E1;1/2-→1/2+)=0.102(2) e2fm was determined using the semi-classical code Gosia, and a value of 0.098(4) e2fm was determined using the Extended Continuum Discretized Coupled Channels method with the quantum mechanical code FRESCO. These extracted B(E1) values are consistent with the average value determined by a model-dependent analysis of intermediate energy Coulomb excitation measurements and are approximately 14% lower than that determined by a lifetime measurement. The much-improved precisions of 2% and 4% in the measured B(E1) values between the bound states deduced using Gosia and the Extended Continuum Discretized Coupled Channels method, respectively, compared to the previous accuracy of ˜10% will help in our understanding of and better improve the realistic inter-nucleon interactions.

2H NMR and 13C-IRMS analyses of acetic acid from vinegar, 18O-IRMS analysis of water in vinegar: international collaborative study report.

PubMed

Thomas, Freddy; Jamin, Eric

2009-09-01

An international collaborative study of isotopic methods applied to control the authenticity of vinegar was organized in order to support the recognition of these procedures as official methods. The determination of the 2H/1H ratio of the methyl site of acetic acid by SNIF-NMR (site-specific natural isotopic fractionation-nuclear magnetic resonance) and the determination of the 13C/12C ratio, by IRMS (isotope ratio mass spectrometry) provide complementary information to characterize the botanical origin of acetic acid and to detect adulterations of vinegar using synthetic acetic acid. Both methods use the same initial steps to recover pure acetic acid from vinegar. In the case of wine vinegar, the determination of the 18O/16O ratio of water by IRMS allows to differentiate wine vinegar from vinegars made from dried grapes. The same set of vinegar samples was used to validate these three determinations. The precision parameters of the method for measuring delta13C (carbon isotopic deviation) were found to be similar to the values previously obtained for similar methods applied to wine ethanol or sugars extracted from fruit juices: the average repeatability (r) was 0.45 per thousand, and the average reproducibility (R) was 0.91 per thousand. As expected from previous in-house study of the uncertainties, the precision parameters of the method for measuring the 2H/1H ratio of the methyl site were found to be slightly higher than the values previously obtained for similar methods applied to wine ethanol or fermentation ethanol in fruit juices: the average repeatability was 1.34 ppm, and the average reproducibility was 1.62 ppm. This precision is still significantly smaller than the differences between various acetic acid sources (delta13C and delta18O) and allows a satisfactory discrimination of vinegar types. The precision parameters of the method for measuring delta18O were found to be similar to the values previously obtained for other methods applied to wine and fruit juices: the average repeatability was 0.15 per thousand, and the average reproducibility was 0.59 per thousand. The above values are proposed as repeatability and reproducibility limits in the current state of the art. On the basis of this satisfactory inter-laboratory precision and on the accuracy demonstrated by a spiking experiment, the authors recommend the adoption of the three isotopic determinations included in this study as official methods for controlling the authenticity of vinegar.

Eigen values in epidemic and other bio-inspired models

NASA Astrophysics Data System (ADS)

Supriatna, A. K.; Anggriani, N.; Carnia, E.; Raihan, A.

2017-08-01

Eigen values and the largest eigen value have special roles in many applications. In this paper we will discuss its role in determining the epidemic threshold in which we can determine if an epidemic will decease or blow out eventually. Some examples and their consequences to controling the epidemic are also discusses. Beside the application in epidemic model, the paper also discusses other example of appication in bio-inspired model, such as the backcross breeding for two age classes of local and exotic goats. Here we give some elaborative examples on the use of previous backcross breeding model. Some future direction on the exploration of the relationship between these eigenvalues to different epidemic models and other bio-inspired models are also presented.

The Br+HO 2 reaction revisited: Absolute determination of the rate constant at 298 K

NASA Astrophysics Data System (ADS)

Laverdet, G.; Le Bras, G.; Mellouki, A.; Poulet, G.

1990-09-01

The absolute determination of the rate constant for the reaction Br+HO 2→HBr+O 2 has been done at 298 K using the discharge-flor EPR method. The value k1 = (1.5±0.2) × 10 -12 cm 3 molecule -1 s -1 was obtained. Previous indirect measurements of k1 from a discharge-flow, LIF/mass spectrometric study of the Br/H 2CO/O 2 system have been reinterpreted, leading to values for k1 ranging from 1.0 × 10 -12 to 2.2 × 10 -12 cm 3 molecule -1 s -1 at 298 K. These results are discussed and compared with other literature values.

Investigating the procedural variables that determine whether rats will display negative anticipatory contrast or positive induction.

PubMed

Weatherly, Jeffrey N; Nurnberger, Jeri T; Hanson, Brent C

2005-08-31

Previous studies have demonstrated that consumption of a low-valued food substance may decrease if access to a high-valued substance will soon be available (negative anticipatory contrast). Research has also demonstrated that responding for a low-valued reinforcer may increase if responding for a high-valued reinforcer will soon be possible (positive induction). The present experiment employed rats to respond in a procedure similar to that typically used to produce negative anticipatory contrast. The goal was to determine what factors contribute to when a contrast or an induction effect will occur. Based on previous research, the influence of auditory cues, temporal delays, food deprivation, and location of substance delivery were investigated. Auditory cues and temporal delays did little to influence whether subjects increased or decreased their consumption of 1% sucrose when access to 32% sucrose was upcoming. The appearance of contrast or induction was related to level of deprivation, with deprivation promoting induction. Which effect occurred also depended on whether subjects consumed the two substances from one spout in one location (induction) or from two different spouts in two different locations (contrast). The present results help identify the procedural link(s) between these two effects. They also provide insight to why positive induction may occur (i.e., higher-order place conditioning).

High-Precision Half-Life and Branching Ratio Measurements for the Superallowed β+ Emitter 26Alm

NASA Astrophysics Data System (ADS)

Finlay, P.; Svensson, C. E.; Demand, G. A.; Garrett, P. E.; Green, K. L.; Leach, K. G.; Phillips, A. A.; Rand, E. T.; Ball, G.; Bandyopadhyay, D.; Djongolov, M.; Ettenauer, S.; Hackman, G.; Pearson, C. J.; Leslie, J. R.; Andreoiu, C.; Cross, D.; Austin, R. A. E.; Grinyer, G. F.; Sumithrarachchi, C. S.; Williams, S. J.; Triambak, S.

2013-03-01

High-precision half-life and branching-ratio measurements for the superallowed β+ emitter 26Alm were performed at the TRIUMF-ISAC radioactive ion beam facility. An upper limit of ≤ 15 ppm at 90% C.L. was determined for the sum of all possible non-analogue β+/EC decay branches of 26Alm, yielding a superallowed branching ratio of 100.0000+0-0.0015%. A value of T1/2 = 6:34654(76) s was determined for the 26Alm half-life which is consistent with, but 2.5 times more precise than, the previous world average. Combining these results with world-average measurements yields an ft value of 3037.58(60) s, the most precisely determined for any superallowed emitting nucleus to date. This high-precision ft value for 26Alm provides a new benchmark to refine theoretical models of isospin-symmetry-breaking effects in superallowed β decays.

Rapid Determination of Surfactant Critical Micelle Concentrations Using Pressure-Driven Flow with Capillary Electrophoresis Instrumentation

PubMed Central

Stanley, F. E.; Warner, A. M.; Schneiderman, E.; Stalcup, A. M.

2009-01-01

This work demonstrates a novel, convenient utilization of capillary electrophoresis (CE) instrumentation for the determination of critical micelle concentrations (CMCs). Solution viscosity differences across a range of surfactant concentrations were monitored by hydrodynamically forcing an analyte towards the detector. Upon reaching the surfactant's CMC value, migration times were observed to change drastically. CMC values for four commonly employed anionic surfactants were determined - sodium dodecyl sulfate: 8.1 mM; sodium caprylate- 300 mM; sodium decanoate- 86 mM; sodium laurate- 30 mM; and found to be in excellent agreement with values previously reported in the literature. The technique was then applied to the less well-characterized nonionic surfactants poly(oxyethylene) 8 myristyl ether (CMC ~ 9 μM), poly(oxyethylene) 8 decyl ether (CMC ~ 0.95 mM) and poly(oxyethylene) 4 lauryl ether. PMID:19836753

Thermodynamics and Human Population

NASA Astrophysics Data System (ADS)

Cordry, Sean M.

2010-09-01

This paper discusses a Fermi-problem exercise through which I take students in several of my college courses. Students work in teams, determining the average daily Caloric needs per person. Then they use insolation values to determine the size of a collection area needed to absorb the previously determined daily energy requirements. Adjustments to the size of the collection area are made based on energy absorption per biological trophic level, as well as the consideration that most diets are a mixture of plant- and animal-derived elements. Finally, using the total amount of farmland available on the planet, students calculate a maximum population value. Although the maximum population values derived herewith should not be considered authoritative, the exercise has three beneficial purposes: 1) a chance to talk about the modeling process and extrapolations, 2) an unexpected application of physics to social contexts, and 3) raising student awareness of population and energy issues.

Correlates of Leadership Decision Patterns of High School Pupils Socio-Economic Status, High School Grade, and Connotative Meaning of the Word "Leadership."

ERIC Educational Resources Information Center

McMillion, Martin B.

In a previous study by the investigator, it was determined that the lowest socioeconomic strata of pupils valued leadership significantly higher than did the upper socioeconomic group. This follow-up study attempted to determine whether pupils with similar connotations of leadership were more likely to be democratic leaders or autocratic leaders,…

The Perceived Value of Education and Educational Aspirations in the Czech Republic: Changes in the Determination of Educational Aspirations between 1989 and 2003

ERIC Educational Resources Information Center

Mateju, Petr; Smith, Michael L.

2009-01-01

This article compares the changes in the determination of educational aspirations from the end of the communist period in 1989 to 2003, focusing on a single postcommunist country, the Czech Republic. The Czech case is particularly relevant for comparative research on educational inequality and aspirations, as previous studies have shown…

Lead and Arsenic Bioaccessibility and Speciation as a Function of Soil Particle Size

EPA Science Inventory

Bioavailability research of soil metals has advanced considerably from default values to validated in vitro bioaccessibility (IVBA) assays for site-specific risk assessment. Previously, USEPA determined that the soil-size fraction representative of dermal adherence and consequent...

Family and home characteristics correlate with mold in homes

EPA Science Inventory

Previously, we demonstrated that infants exposed to higher Environmental Relative Moldiness Index (ERMI) value homes were more likely to develop asthma by age seven. The purpose of this analysis was to determine what family and home characteristics were associated with higher ER...

Atherogenic lipid phenotype in a general group of subjects.

PubMed

Van, Joanne; Pan, Jianqiu; Charles, M Arthur; Krauss, Ronald; Wong, Nathan; Wu, Xiaoshan

2007-11-01

The atherogenic lipid phenotype is a major cardiovascular risk factor, but normal values do not exist derived from 1 analysis in a general study group. To determine normal values of all of the atherogenic lipid phenotype parameters using subjects from a general study group. One hundred two general subjects were used to determine their atherogenic lipid phenotype using polyacrylamide gradient gels. Low-density lipoprotein (LDL) size revealed 24% of subjects express LDL phenotype B, defined as average LDL peak particle size 258 A or less; however, among the Chinese subjects, the expression of the B phenotype was higher at 44% (P = .02). For the total group, mean LDL size was 265 +/- 11 A (1 SD); however, histograms were bimodal in both men and women. After excluding subjects expressing LDL phenotype B, because they are at increased cardiovascular risk and thus are not completely healthy, LDL histograms were unimodal and the mean LDL size was 270 +/- 7 A. A small, dense LDL concentration histogram (total group) revealed skewing; thus, phenotype B subjects were excluded, for the rationale described previously, and the mean value was 13 +/- 9 mg/dL (0.33 +/- 0.23 mmol/L). High-density lipoprotein (HDL) cholesterol histograms were bimodal in both sexes. After removing subjects as described previously or if HDL cholesterol levels were less than 45 mg/dL, histograms were unimodal and revealed a mean HDL cholesterol value of 61 +/- 12 mg/dL (1.56 +/- 0.31 mmol/L). HDL 2, HDL 2a, and HDL 2b were similarly evaluated. Approximate normal values for the atherogenic lipid phenotype, similar to those derived from cardiovascular endpoint trials, can be determined if those high proportions of subjects with dyslipidemic cardiovascular risk are excluded.

The Atomization Energy of Mg4

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Arnold, James O. (Technical Monitor)

1999-01-01

The atomization energy of Mg4 is determined using the MP2 and CCSD(T) levels of theory. Basis set incompleteness, basis set extrapolation, and core-valence effects are discussed. Our best atomization energy, including the zero-point energy and scalar relativistic effects, is 24.6+/-1.6 kcal per mol. Our computed and extrapolated values are compared with previous results, where it is observed that our extrapolated MP2 value is good agreement with the MP2-R12 value. The CCSD(T) and MP2 core effects are found to have the opposite signs.

Interstitial water studies on small core samples, Deep Sea Drilling Project, Leg 6

USGS Publications Warehouse

Manheim, F. T.; Sayles, F.L.

1971-01-01

Sediments from Leg 6 sites, west of the Hawaiian Islands, consisted primarily of various combinations of deep-sea biogenic oozes, volcanic ash, and its breakdown products. Pore fluids from most of the sites were similar in composition to present day ocean water, and in some sties almost identical. However, interstitial fluids from Site 53 (Philippine Sea) showed changes in ionic composition which were beyond those previously considered attributable to diagenetic influence. These samples show the beginnings of metamorphism by dramatic increases in calcium concentrations and corresponding decreases in alkali concentrations. Analytical methods were similar to those outlined in previous Leg Reports. However, obvious contamination of aliquots for sodium determination in the laboratory made it necessary to determine all sodium values by difference between anion and cation balances. These values are, if anything, more accurate than direct determinations which have been discussed in earlier legs. However, the authors will continue to analyze sodium directly, and in the future they may be able to improve the precision of the determinations to the point where small losses and gains of sodium in the pore fluids may be established accurately. Agreement between colorimetric and spectrometric determinations of silicon has improved, but there are still occasional marked differences for which the writers have no explanation. T. Takahashi has allowed the authors to compare total Carbon Dioxide (CO2) measurements from his laboratory with their alkalinity determinations: both sets of data were obtained from fluids from the same squeezings of sediments and should give similar values at the indicated pH levels. Some disturbingly large discrepancies in the two sets of data are evident. The authors do not think that their back-titration alkalinity technique alone is responsible for the differences. However, they have not evaluated the possible influence of the heat-sealed polyethylene pipes on the alkalinity values; this should be considered a potential source of error. The pH data from water samples processed and measured on shipboard are reported here. In view of the major changes in pressure and temperature (laboratory temperatures were reported to be 26 to 28°C) and the sediments to new gaseous regimes prior to pH measurement, these values should be interpreted mainly as applying to the squeezed effluents, not to in situ values.

Direct URCA process in neutron stars

NASA Technical Reports Server (NTRS)

Lattimer, James M.; Prakash, Madappa; Pethick, C. J.; Haensel, Pawel

1991-01-01

It is shown that the direct URCA process can occur in neutron stars if the proton concentration exceeds some critical value in the range 11-15 percent. The proton concentration, which is determined by the poorly known symmetry energy of matter above nuclear density, exceeds the critical value in many current calculations. If it occurs, the direct URCA process enhances neutrino emission and neutron star cooling rates by a large factor compared to any process considered previously.

Ultra-precise single-ion atomic mass measurements on deuterium and helium-3

NASA Astrophysics Data System (ADS)

Zafonte, S. L.; Van Dyck, R. S., Jr.

2015-04-01

The former University of Washington Penning Trap Mass Spectrometer (UW-PTMS), now located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany, was used in the decade before the move to determine new values for the deuteron atomic mass, M (2H+) = 2.013 553 212 745(40) u, and the deuterium atomic mass, M (2H) = 2.014 101 778 052(40) u, both of which are now more than an order-of-magnitude more accurate than the previous best 1994-MIT measurements of these quantities. The new value for the deuteron’s mass can then be used with the accepted 2010-CODATA proton mass and the most recent 1999-measurement of the 2.2 MeV gamma-ray binding energy of the deuteron to refine the neutron’s mass to mn = 1.008 664 916 018(435) u which has about half the uncertainty relative to the value computed using that previous 1994-MIT deuterium measurement. As a result, further improvements of mn must now come from a more accurate determination of the wavelength of this gamma ray. In this same period of time, this spectrometer has also been used to determine new values for the helion atomic mass, M (3He2+) = 3.014 932 246 668(43) u, and the neutral helium-3 atomic mass, M (3He) = 3.016 029 321 675(43) u, which are both about 60 times more accurate than the 2006-SMILETRAP measurements, but disagree with the 4.4-times less-accurate 2015-Florida-State measurements by 0.76 nu. It is expected that these helium-3 results will be used in the future 3H/3He mass ratio (to be determined by the Heidelberg, Germany version of the old UW-PTMS) in order to generate a more accurate value for the tritium atomic mass.

Application of an automatic approach to calibrate the NEMURO nutrient-phytoplankton-zooplankton food web model in the Oyashio region

NASA Astrophysics Data System (ADS)

Ito, Shin-ichi; Yoshie, Naoki; Okunishi, Takeshi; Ono, Tsuneo; Okazaki, Yuji; Kuwata, Akira; Hashioka, Taketo; Rose, Kenneth A.; Megrey, Bernard A.; Kishi, Michio J.; Nakamachi, Miwa; Shimizu, Yugo; Kakehi, Shigeho; Saito, Hiroaki; Takahashi, Kazutaka; Tadokoro, Kazuaki; Kusaka, Akira; Kasai, Hiromi

2010-10-01

The Oyashio region in the western North Pacific supports high biological productivity and has been well monitored. We applied the NEMURO (North Pacific Ecosystem Model for Understanding Regional Oceanography) model to simulate the nutrients, phytoplankton, and zooplankton dynamics. Determination of parameters values is very important, yet ad hoc calibration methods are often used. We used the automatic calibration software PEST (model-independent Parameter ESTimation), which has been used previously with NEMURO but in a system without ontogenetic vertical migration of the large zooplankton functional group. Determining the performance of PEST with vertical migration, and obtaining a set of realistic parameter values for the Oyashio, will likely be useful in future applications of NEMURO. Five identical twin simulation experiments were performed with the one-box version of NEMURO. The experiments differed in whether monthly snapshot or averaged state variables were used, in whether state variables were model functional groups or were aggregated (total phytoplankton, small plus large zooplankton), and in whether vertical migration of large zooplankton was included or not. We then applied NEMURO to monthly climatological field data covering 1 year for the Oyashio, and compared model fits and parameter values between PEST-determined estimates and values used in previous applications to the Oyashio region that relied on ad hoc calibration. We substituted the PEST and ad hoc calibrated parameter values into a 3-D version of NEMURO for the western North Pacific, and compared the two sets of spatial maps of chlorophyll- a with satellite-derived data. The identical twin experiments demonstrated that PEST could recover the known model parameter values when vertical migration was included, and that over-fitting can occur as a result of slight differences in the values of the state variables. PEST recovered known parameter values when using monthly snapshots of aggregated state variables, but estimated a different set of parameters with monthly averaged values. Both sets of parameters resulted in good fits of the model to the simulated data. Disaggregating the variables provided to PEST into functional groups did not solve the over-fitting problem, and including vertical migration seemed to amplify the problem. When we used the climatological field data, simulated values with PEST-estimated parameters were closer to these field data than with the previously determined ad hoc set of parameter values. When these same PEST and ad hoc sets of parameter values were substituted into 3-D-NEMURO (without vertical migration), the PEST-estimated parameter values generated spatial maps that were similar to the satellite data for the Kuroshio Extension during January and March and for the subarctic ocean from May to November. With non-linear problems, such as vertical migration, PEST should be used with caution because parameter estimates can be sensitive to how the data are prepared and to the values used for the searching parameters of PEST. We recommend the usage of PEST, or other parameter optimization methods, to generate first-order parameter estimates for simulating specific systems and for insertion into 2-D and 3-D models. The parameter estimates that are generated are useful, and the inconsistencies between simulated values and the available field data provide valuable information on model behavior and the dynamics of the ecosystem.

Actinide abundances in ordinary chondrites

USGS Publications Warehouse

Hagee, B.; Bernatowicz, T.J.; Podosek, F.A.; Johnson, M.L.; Burnett, D.S.; Tatsumoto, M.

1990-01-01

Measurements of 244Pu fission Xe, U, Th, and light REE (LREE) abundances, along with modal petrographic determinations of phosphate abundances, were carried out on equilibrated ordinary chondrites in order to define better the solar system Pu abundance and to determine the degree of variation of actinide and LREE abundances. Our data permit comparison of the directly measured Pu/ U ratio with that determined indirectly as (Pu/Nd) ?? (Nd/U) assuming that Pu behaves chemically as a LREE. Except for Guaren??a, and perhaps H chondrites in general, Pu concentrations are similar to that determined previously for St. Se??verin, although less precise because of higher trapped Xe contents. Trapped 130Xe 136Xe ratios appear to vary from meteorite to meteorite, but, relative to AVCC, all are similar in the sense of having less of the interstellar heavy Xe found in carbonaceous chondrite acid residues. The Pu/U and Pu/Nd ratios are consistent with previous data for St. Se??verin, but both tend to be slightly higher than those inferred from previous data on Angra dos Reis. Although significant variations exist, the distribution of our Th/U ratios, along with other precise isotope dilution data for ordinary chondrites, is rather symmetric about the CI chondrite value; however, actinide/(LREE) ratios are systematically lower than the CI value. Variations in actinide or LREE absolute and relative abundances are interpreted as reflecting differences in the proportions and/or compositions of more primitive components (chondrules and CAI materials?) incorporated into different regions of the ordinary chondrite parent bodies. The observed variations of Th/U, Nd/U, or Ce/U suggest that measurements of Pu/U on any single equilibrated ordinary chondrite specimen, such as St. Se??verin, should statistically be within ??20-30% of the average solar system value, although it is also clear that anomalous samples exist. ?? 1990.

Alpha-cluster preformation factor within cluster-formation model for odd-A and odd-odd heavy nuclei

NASA Astrophysics Data System (ADS)

Saleh Ahmed, Saad M.

2017-06-01

The alpha-cluster probability that represents the preformation of alpha particle in alpha-decay nuclei was determined for high-intensity alpha-decay mode odd-A and odd-odd heavy nuclei, 82 < Z < 114, 111 < N < 174. This probability was calculated using the energy-dependent formula derived from the formulation of clusterisation states representation (CSR) and the hypothesised cluster-formation model (CFM) as in our previous work. Our previous successful determination of phenomenological values of alpha-cluster preformation factors for even-even nuclei motivated us to expand the work to cover other types of nuclei. The formation energy of interior alpha cluster needed to be derived for the different nuclear systems with considering the unpaired-nucleon effect. The results showed the phenomenological value of alpha preformation probability and reflected the unpaired nucleon effect and the magic and sub-magic effects in nuclei. These results and their analyses presented are very useful for future work concerning the calculation of the alpha decay constants and the progress of its theory.

Extraction, Scrub, and Strip Test Results for the Salt Waste Processing Facility Caustic Side Solvent Extraction Solvent Sample

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T. B.

An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D( Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D( Cs) measured 12.5, exceeding the required value of 8. This value is consistent with resultsmore » from previous ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges. This revision was created to correct an error. The previous revision used an incorrect set of temperature correction coefficients which resulted in slight deviations from the correct D( Cs) results.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bachman, D., E-mail: bachman@ualberta.ca; Fedosejevs, R.; Tsui, Y. Y.

An optical damage threshold for crystalline silicon from single femtosecond laser pulses was determined by detecting a permanent change in the refractive index of the material. This index change could be detected with unprecedented sensitivity by measuring the resonant wavelength shift of silicon integrated optics microring resonators irradiated with femtosecond laser pulses at 400 nm and 800 nm wavelengths. The threshold for permanent index change at 400 nm wavelength was determined to be 0.053 ± 0.007 J/cm{sup 2}, which agrees with previously reported threshold values for femtosecond laser modification of crystalline silicon. However, the threshold for index change at 800 nm wavelength was found to be 0.044 ± 0.005 J/cm{supmore » 2}, which is five times lower than the previously reported threshold values for visual change on the silicon surface. The discrepancy is attributed to possible modification of the crystallinity of silicon below the melting temperature that has not been detected before.« less

Fuzzy difference-of-Gaussian-based iris recognition method for noisy iris images

NASA Astrophysics Data System (ADS)

Kang, Byung Jun; Park, Kang Ryoung; Yoo, Jang-Hee; Moon, Kiyoung

2010-06-01

Iris recognition is used for information security with a high confidence level because it shows outstanding recognition accuracy by using human iris patterns with high degrees of freedom. However, iris recognition accuracy can be reduced by noisy iris images with optical and motion blurring. We propose a new iris recognition method based on the fuzzy difference-of-Gaussian (DOG) for noisy iris images. This study is novel in three ways compared to previous works: (1) The proposed method extracts iris feature values using the DOG method, which is robust to local variations of illumination and shows fine texture information, including various frequency components. (2) When determining iris binary codes, image noises that cause the quantization error of the feature values are reduced with the fuzzy membership function. (3) The optimal parameters of the DOG filter and the fuzzy membership function are determined in terms of iris recognition accuracy. Experimental results showed that the performance of the proposed method was better than that of previous methods for noisy iris images.

Level of endogenous formaldehyde in maple syrup as determined by spectrofluorimetry.

PubMed

Lagacé, Luc; Guay, Stéphane; Martin, Nathalie

2003-01-01

The level of endogenous formaldehyde in maple syrup was established from a large number (n = 300) of authentic maple syrup samples collected during 2000 and 2001 in the province of Quebec, Canada. The average level of formaldehyde from these authentic samples was measured at 0.18 mg/kg in 2000 and 0.28 mg/kg in 2001, which is lower than previously published. These average values can be attributed to the improved spectrofluorimetric method used for the determination. However, the formaldehyde values obtained demonstrate a relatively large distribution with maximums observed at 1.04 and 1.54 mg/kg. These values are still under the maximum tolerance level of 2.0 mg/kg paraformaldehyde pesticide residue. Extensive heat treatment of maple syrup samples greatly enhanced the formaldehyde concentration of the samples, suggesting that extensive heat degradation of the sap constituents during evaporation could be responsible for the highest formaldehyde values in maple syrup.

Understanding unemployed people's job search behaviour, unemployment experience and well-being: a comparison of expectancy-value theory and self-determination theory.

PubMed

Vansteenkiste, Maarten; Lens, Willy; De Witte, Hans; Feather, N T

2005-06-01

Previous unemployment research has directly tested hypotheses derived from expectancy-value theory (EVT; Feather, 1982, 1990), but no comparative analysis has been executed with another motivational framework. In one large study with 446 unemployed people, separate analyses provided good evidence for predictions derived from both EVT and self-determination theory (SDT; Deci & Ryan, 1985, 2000). Comparative analyses indicated that the type of people's job search motivation, as conceptualized through the notions of autonomous versus controlled motivation within SDT, is an important predictor of people's unemployment experience and wellbeing, beyond people's strength of motivation assessed within EVT through expectancies of finding a job and employment value. The importance of simultaneously testing two theoretical frameworks is discussed.

Modelling the stochastic nature of the available coefficient of friction at footwear-floor interfaces.

PubMed

Gragg, Jared; Klose, Ellison; Yang, James

2017-07-01

The available coefficient of friction (ACOF) is a measure of the friction available between two surfaces, which for human gait would be the footwear-floor interface. It is often compared to the required coefficient of friction (RCOF) to determine the likelihood of a slip in gait. Both the ACOF and RCOF are stochastic by nature meaning that neither should be represented by a deterministic value, such as the sample mean. Previous research has determined that the RCOF can be modelled well by either the normal or lognormal distributions, but previous research aimed at determining an appropriate distribution for the ACOF was inconclusive. This study focuses on modelling the stochastic nature of the ACOF by fitting eight continuous probability distributions to ACOF data for six scenarios. In addition, the data were used to study the effect that a simple housekeeping action such as sweeping could have on the ACOF. Practitioner Summary: Previous research aimed at determining an appropriate distribution for the ACOF was inconclusive. The study addresses this issue as well as looking at the effect that an act such as sweeping has on the ACOF.

Calibration strategies for the determination of stable carbon absolute isotope ratios in a glycine candidate reference material by elemental analyser-isotope ratio mass spectrometry.

PubMed

Dunn, Philip J H; Malinovsky, Dmitry; Goenaga-Infante, Heidi

2015-04-01

We report a methodology for the determination of the stable carbon absolute isotope ratio of a glycine candidate reference material with natural carbon isotopic composition using EA-IRMS. For the first time, stable carbon absolute isotope ratios have been reported using continuous flow rather than dual inlet isotope ratio mass spectrometry. Also for the first time, a calibration strategy based on the use of synthetic mixtures gravimetrically prepared from well characterised, highly (13)C-enriched and (13)C-depleted glycines was developed for EA-IRMS calibration and generation of absolute carbon isotope ratio values traceable to the SI through calibration standards of known purity. A second calibration strategy based on converting the more typically determined delta values on the Vienna PeeDee Belemnite (VPDB) scale using literature values for the absolute carbon isotope ratio of VPDB itself was used for comparison. Both calibration approaches provided results consistent with those previously reported for the same natural glycine using MC-ICP-MS; absolute carbon ratios of 10,649 × 10(-6) with an expanded uncertainty (k = 2) of 24 × 10(-6) and 10,646 × 10(-6) with an expanded uncertainty (k = 2) of 88 × 10(-6) were obtained, respectively. The absolute carbon isotope ratio of the VPDB standard was found to be 11,115 × 10(-6) with an expanded uncertainty (k = 2) of 27 × 10(-6), which is in excellent agreement with previously published values.

High-precision half-life measurements of the T =1 /2 mirror β decays 17F and 33Cl

NASA Astrophysics Data System (ADS)

Grinyer, J.; Grinyer, G. F.; Babo, M.; Bouzomita, H.; Chauveau, P.; Delahaye, P.; Dubois, M.; Frigot, R.; Jardin, P.; Leboucher, C.; Maunoury, L.; Seiffert, C.; Thomas, J. C.; Traykov, E.

2015-10-01

Background: Measurements of the f t values for T =1 /2 mirror β+ decays offer a method to test the conserved vector current hypothesis and to determine Vud, the up-down matrix element of the Cabibbo-Kobayashi-Maskawa matrix. In most mirror decays used for these tests, uncertainties in the f t values are dominated by the uncertainties in the half-lives. Purpose: Two precision half-life measurements were performed for the T =1 /2 β+ emitters, 17F and 33Cl, in order to eliminate the half-life as the leading source of uncertainty in their f t values. Method: Half-lives of 17F and 33Cl were determined using β counting of implanted radioactive ion beam samples on a moving tape transport system at the Système de Production d'Ions Radioactifs Accélérés en Ligne low-energy identification station at the Grand Accélérateur National d'Ions Lourds. Results: The 17F half-life result, 64.347 (35) s, precise to ±0.05 % , is a factor of 5 times more precise than the previous world average. The half-life of 33Cl was determined to be 2.5038 (22) s. The current precision of ±0.09 % is nearly 2 times more precise compared to the previous world average. Conclusions: The precision achieved during the present measurements implies that the half-life no longer dominates the uncertainty of the f t values for both T =1 /2 mirror decays 17F and 33Cl.

PROGNOSTIC VALUE OF SHAPE-DESCRIPTIVE FACTORS FOR THE PROGRESSION OF GEOGRAPHIC ATROPHY SECONDARY TO AGE-RELATED MACULAR DEGENERATION.

PubMed

Pfau, Maximilian; Lindner, Moritz; Goerdt, Lukas; Thiele, Sarah; Nadal, Jennifer; Schmid, Matthias; Schmitz-Valckenberg, Steffen; Sadda, SriniVas R; Holz, Frank G; Fleckenstein, Monika

2018-05-16

To systematically compare the prognostic value of multiple shape-descriptive factors in the natural course of the disease. A total of 296 eyes of 201 patients (female patients 130; mean age: 72.2 ± 13.08 years) with a median follow-up of 2.38 years from 2 prospective, noninterventional natural history studies (Fundus-Autofluorescence-in-Age-related-Macular-Degeneration [clinicaltrials.gov identifier NCT00393692], Directional-Spread-in-Geographic-Atrophy [NCT02051998]) were included in the analysis. Serial fundus autofluorescence images were annotated using semiautomated image analysis software to determine the lesion area, circularity, perimeter, and caliper diameters. These variables and the fundus autofluorescence phenotype were evaluated for prediction of the future square root progression rates using linear mixed-effects models. For the combined model, leave-one-out cross validation on patient level (Scenario 1: previously unknown patient) resulted in a goodness-to-fit (R value) of 0.244 and leave-one-out cross validation on visit level (Scenario 2: previous observation of the patient) in a R value of 0.391. This indicated that shape-descriptive factors could explain 24.4% of the variance in geographic atrophy progression in previously unknown patients and 39.1% in patients with previous observation. These findings confirm the relevance of shape-descriptive factors and previous progression as prognostic variables for geographic atrophy progression. However, a substantial part of the remaining variation in geographic atrophy progression seems to depend on other variables, some of which are visible in optical coherence tomography.

Are Einstein's transition probabilities for spontaneous emission constant in plasmas?

NASA Technical Reports Server (NTRS)

Griem, H. R.; Huang, Y. W.; Wang, J.-S.; Moreno, J. C.

1991-01-01

An investigation is conducted with a ruby laser to experimentally confirm the quenching of spontaneous emission coefficients and propose a mechanism for the phenomenon. Results of previous experiments are examined to determine the consistency and validity of interpretations of the spontaneous emissions. For the C IV 3s-3p and 2s-3p transitions, the line-intensity ratios are found to be dependent on the separation of the laser from the target. Density gradients and Stark broadening are proposed to interpret the results in a way that does not invalidate the Einstein A values. The interpretation is extended to C III and N V, both of which demonstrate similar changes in A values in previous experiments. The apparent quenching of Ar II by photon collisions is explained by Rabi oscillations and power broadening in the argon-ion laser cavity. It is concluded that the changes in A values cannot result from dense plasma effects.

THE INCLINATION OF THE SOFT X-RAY TRANSIENT A0620-00 AND THE MASS OF ITS BLACK HOLE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cantrell, Andrew G.; Bailyn, Charles D.; Orosz, Jerome A.

2010-02-20

We analyze photometry of the soft X-ray transient A0620 - 00 spanning nearly 30 years, including previously published and previously unpublished data. Previous attempts to determine the inclination of A0620 using subsets of these data have yielded a wide range of measured values of i. Differences in the measured value of i have been due to changes in the shape of the light curve and uncertainty regarding the contamination from the disk. We give a new technique for estimating the disk fraction and find that disk light is significant in all light curves, even in the infrared. We also findmore » that all changes in the shape and normalization of the light curve originate in a variable disk component. After accounting for this disk component, we find that all the data, including light curves of significantly different shapes, point to a consistent value of i. Combining results from many separate data sets, we find i = 51.{sup 0}0 +- 0.{sup 0}9, implying M = 6.6 +- 0.25 M{sub sun}. Using our dynamical model and zero-disk stellar VIH magnitudes, we find d = 1.06 +- 0.12 kpc. Understanding the disk origin of nonellipsoidal variability may assist with making reliable determinations of i in other systems, and the fluctuations in disk light may provide a new observational tool for understanding the three-dimensional structure of the accretion disk.« less

The Inclination of the Soft X-Ray Transient A0620-00 and the Mass of its Black Hole

NASA Astrophysics Data System (ADS)

Cantrell, Andrew G.; Bailyn, Charles D.; Orosz, Jerome A.; McClintock, Jeffrey E.; Remillard, Ronald A.; Froning, Cynthia S.; Neilsen, Joseph; Gelino, Dawn M.; Gou, Lijun

2010-02-01

We analyze photometry of the soft X-ray transient A0620 - 00 spanning nearly 30 years, including previously published and previously unpublished data. Previous attempts to determine the inclination of A0620 using subsets of these data have yielded a wide range of measured values of i. Differences in the measured value of i have been due to changes in the shape of the light curve and uncertainty regarding the contamination from the disk. We give a new technique for estimating the disk fraction and find that disk light is significant in all light curves, even in the infrared. We also find that all changes in the shape and normalization of the light curve originate in a variable disk component. After accounting for this disk component, we find that all the data, including light curves of significantly different shapes, point to a consistent value of i. Combining results from many separate data sets, we find i = 51fdg0 ± 0fdg9, implying M = 6.6 ± 0.25 M sun. Using our dynamical model and zero-disk stellar VIH magnitudes, we find d = 1.06 ± 0.12 kpc. Understanding the disk origin of nonellipsoidal variability may assist with making reliable determinations of i in other systems, and the fluctuations in disk light may provide a new observational tool for understanding the three-dimensional structure of the accretion disk.

Precision half-life measurement of 11C: The most precise mirror transition F t value

NASA Astrophysics Data System (ADS)

Valverde, A. A.; Brodeur, M.; Ahn, T.; Allen, J.; Bardayan, D. W.; Becchetti, F. D.; Blankstein, D.; Brown, G.; Burdette, D. P.; Frentz, B.; Gilardy, G.; Hall, M. R.; King, S.; Kolata, J. J.; Long, J.; Macon, K. T.; Nelson, A.; O'Malley, P. D.; Skulski, M.; Strauss, S. Y.; Vande Kolk, B.

2018-03-01

Background: The precise determination of the F t value in T =1 /2 mixed mirror decays is an important avenue for testing the standard model of the electroweak interaction through the determination of Vu d in nuclear β decays. 11C is an interesting case, as its low mass and small QE C value make it particularly sensitive to violations of the conserved vector current hypothesis. The present dominant source of uncertainty in the 11CF t value is the half-life. Purpose: A high-precision measurement of the 11C half-life was performed, and a new world average half-life was calculated. Method: 11C was created by transfer reactions and separated using the TwinSol facility at the Nuclear Science Laboratory at the University of Notre Dame. It was then implanted into a tantalum foil, and β counting was used to determine the half-life. Results: The new half-life, t1 /2=1220.27 (26 ) s, is consistent with the previous values but significantly more precise. A new world average was calculated, t1/2 world=1220.41 (32 ) s, and a new estimate for the Gamow-Teller to Fermi mixing ratio ρ is presented along with standard model correlation parameters. Conclusions: The new 11C world average half-life allows the calculation of a F tmirror value that is now the most precise value for all superallowed mixed mirror transitions. This gives a strong impetus for an experimental determination of ρ , to allow for the determination of Vu d from this decay.

Improvement of determinating seafloor benchmark position with large-scale horizontal heterogeneity in the ocean area

NASA Astrophysics Data System (ADS)

Uemura, Y.; Tadokoro, K.; Matsuhiro, K.; Ikuta, R.

2015-12-01

The most critical issue in reducing the accuracy of seafloor positioning system, GPS/Acoustic technique, is large-scale thermal gradient of sound-speed structure [Muto et al., 2008] due to the ocean current. For example, Kuroshio Current, near our observation station, forms this structure. To improve the accuracy of seafloor benchmark position (SBP), we need to directly measure the structure frequently, or estimate it from travel time residual. The former, we repeatedly measure the sound-speed at Kuroshio axis using Underway CTD and try to apply analysis method of seafloor positioning [Yasuda et al., 2015 AGU meeting]. The latter, however, we cannot estimate the structure using travel time residual until now. Accordingly, in this study, we focus on azimuthal dependence of Estimated Mean Sound-Speed (EMSS). EMSS is defined as distance between vessel position and estimated SBP divided by travel time. If thermal gradient exists and SBP is true, EMSS should have azimuthal dependence with the assumption of horizontal layered sound-speed structure in our previous analysis method. We use the data at KMC located on the central part of Nankai Trough, Japan on Jan. 28, 2015, because on that day KMC was on the north edge of Kuroshio, where we expect that thermal gradient exists. In our analysis method, the hyper parameter (μ value) weights travel time residual and rate of change of sound speed structure. However, EMSS derived from μ value determined by Ikuta et al. [2008] does not have azimuthal dependence, that is, we cannot estimate thermal gradient. Thus, we expect SBP has a large bias. Therefore, in this study, we use another μ value and examine whether EMSS has azimuthal dependence or not. With the μ value of this study, which is 1 order of magnitude smaller than the previous value, EMSS has azimuthal dependence that is consistent with observation day's thermal gradient. This result shows that we can estimate the thermal gradient adequately. This SBP displaces 25.6 cm to the north and 11.8 cm to the east compared to previous SBP. This displacement reduces the bias of SBP and RMS of horizontal component in time series to 1/3. Therefore, determination of SBP is suitable when the thermal gradient exists on observation day and EMSS has azimuthal dependence for redetermination of μ value.

Sensitivity of solar-cell performance to atmospheric variables. 1: Single cell

NASA Technical Reports Server (NTRS)

Klucher, T. M.

1976-01-01

The short circuit current of a typical silicon solar cell under direct solar radiation was measured for a range of turbidity, water vapor content, and air mass to determine the relation of the solar cell calibration value (current-to-intensity ratio) to those atmospheric variables. A previously developed regression equation was modified to describe the relation between calibration value, turbidity, water vapor content, and air mass. Based on the value of the constants obtained by a least squares fit of the data to the equation, it was found that turbidity lowers the value, while increase in water vapor increases the calibration value. Cell calibration values exhibited a change of about 6% over the range of atmospheric conditions experienced.

The Instructional Values of Humanistic Educators: An Expanded, Empirical Analysis.

ERIC Educational Resources Information Center

Shapiro, Stewart B.

1987-01-01

Expanded a previous factorial study of the writings of 40 humanistic educators by including 89 educators. Revealed two new factors--self-determined evaluation and a spiritual-transpersonal factor--as important principles of humanistic education. Confirmed the original factors, a general humanistic instructional paradigm, democratically induced…

Isotope-coded, iodoacetamide-based reagent to determine individual cysteine pKa values by MALDI-TOF mass spectrometry

PubMed Central

Nelson, Kimberly J.; Day, Amanda E.; Zeng, Bubing B.; King, S. Bruce; Poole, Leslie B.

2008-01-01

Cysteine reactivity in enzymes is imparted to a large extent by the stabilization of the deprotonated form of the reduced cysteine (i.e. the thiolate) within the active site. While this is likely to be an important chemical attribute of many thiol-based enzymes including cysteine-dependent peroxidases (peroxiredoxins) and proteases, only relatively few pKa values have been determined experimentally. Presented here is a new technique for determining the pKa value of cysteine residues through quantitative mass spectrometry following chemical modification with an iodoacetamide-based reagent over a range of pH buffers. This isotope-coded reagent, N-phenyl iodoacetamide (iodoacetanilide), is readily prepared in deuterated (d5) and protiated (d0) versions and is more reactive toward free cysteine than is iodoacetamide. Using this approach, the pKa values for the two cysteine residues in Escherichia coli thioredoxin were determined to be 6.5 and > 10, in good agreement with previous reports using chemical modification approaches. This technique allows the pKa of specific cysteine residues to be determined in a clear, fast, and simple manner and, because cysteine residues on separate tryptic peptides are measured separately, is not complicated by the presence of multiple cysteines within the protein of interest. PMID:18162165

Value-Based Standards Guide Sexism Inferences for Self and Others.

PubMed

Mitamura, Chelsea; Erickson, Lynnsey; Devine, Patricia G

2017-09-01

People often disagree about what constitutes sexism, and these disagreements can be both socially and legally consequential. It is unclear, however, why or how people come to different conclusions about whether something or someone is sexist. Previous research on judgments about sexism has focused on the perceiver's gender and attitudes, but neither of these variables identifies comparative standards that people use to determine whether any given behavior (or person) is sexist. Extending Devine and colleagues' values framework (Devine, Monteith, Zuwerink, & Elliot, 1991; Plant & Devine, 1998), we argue that, when evaluating others' behavior, perceivers rely on the morally-prescriptive values that guide their own behavior toward women. In a series of 3 studies we demonstrate that (1) people's personal standards for sexism in their own and others' behavior are each related to their values regarding sexism, (2) these values predict how much behavioral evidence people need to infer sexism, and (3) people with stringent, but not lenient, value-based standards get angry and try to regulate a sexist perpetrator's behavior to reduce sexism. Furthermore, these personal values are related to all outcomes in the present work above and beyond other person characteristics previously used to predict sexism inferences. We discuss the implications of differing value-based standards for explaining and reconciling disputes over what constitutes sexist behavior.

Canine Antithrombin-III: Some Biochemical and Biologic Properties

DTIC Science & Technology

1987-06-02

performing amino acid analyses, amino acid sequence analysis, and differential refractometry . I thank Ms. Kerry Singer for her excellent typing and...previously determined by differential refractometry at 546 nm, with a value of 0.186 ml/g for dn/dc (refractive index increment) (69). 20 •, "• 11...J ;,.-0 t.! ’ > ~ +-’ :I c: ... Q) :::J ~ w Protein concentration by refractometry = 8.29 mg/ml O.D. value at 280 nm (1:10 dilution

Olfactory Threshold of Chlorine in Oxygen.

DTIC Science & Technology

1977-09-01

The odor threshold of chlorine in oxygen was determined. Measurements were conducted in an altitude chamber, which provided an odor-free and noise...free background. Human male volunteers, with no previous olfactory acuity testing experience, served as panelists. Threshold values were affected by...time intervals between trials and by age differences. The mean threshold value for 11 subjects was 0.08 ppm obtained by positive responses to the lowest detectable level of chlorine in oxygen, 50% of the time. (Author)

QED test and nuclear radius determination of helium atom by laser spectroscopy

NASA Astrophysics Data System (ADS)

Pavone, F. S.

1995-01-01

The 23S1-33P0 4He transition at λ = 389 nm is measured with respect to a previously frequency calibrated 87Rb two-photon transition at 2λ = 778 nm. The 4He absolute frequency is 770 732 839 058 (190) kHz, with an accuracy of 2.4 parts in 1010. A Lamb shift value of + 4057.61 (79) MHz, with 600 kHz uncertainty arising from the theoretical position of the 33P0 energy level, is extracted for the 23S1. This value is more than two orders of magnitude more accurate than the current best theoretical predictions. By means of a novel heterodyne spectrometer using only one laser tuned at the atomic frequency, we have measured for the first time the 3He-4He isotope separation for the 23S1-33P0 transition at 389 nm. Our experimental result of 45 394 425 (140) kHz, for the F = 1/2-1/2 3He component, is compared with the theoretical prediction which has similar accuracy and depends also on the rms nuclear radius of 3He. For this we determine a preliminary value of 1.923 (37) fm which shows a slight discrepancy with previous values obtained by extrapolation to zero momentum transfer from high energy scattering measurements.

Correlation of the Rates of Solvolysis of i-Butyl Fluoroformate and a Consideration of Leaving-Group Effects

PubMed Central

Lee, Yelin; Park, Kyoung-Ho; Seong, Mi Hye; Kyong, Jin Burm; Kevill, Dennis N.

2011-01-01

The specific rates of solvolysis of isobutyl fluoroformate (1) have been measured at 40.0 °C in 22 pure and binary solvents. These results correlated well with the extended Grunwald-Winstein (G-W) equation, which incorporated the NT solvent nucleophilicity scale and the YCl solvent ionizing power scale. The sensitivities (l and m-values) to changes in solvent nucleophilicity and solvent ionizing power, and the kF/kCl values are very similar to those observed previously for solvolyses of n-octyl fluoroformate, consistent with the additional step of an addition-elimination pathway being rate-determining. The solvent deuterium isotope effect value (kMeOH/kMeOD) for methanolysis of 1 was determined, and for solvolyses in ethanol, methanol, 80% ethanol, and 70% TFE, the values of the enthalpy and the entropy of activation for the solvolysis of 1 were also determined. The results are compared with those reported earlier for isobutyl chloroformate (2) and other alkyl haloformate esters and mechanistic conclusions are drawn. PMID:22174633

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cassata, W. S.; Velsko, C. A.; Stoeffl, W.

We determined fission yields of xenon ( 133mXe, 135Xe, 135mXe, 137Xe, 138Xe, and 139Xe) resulting from 14 MeV neutron induced fission of depleted uranium at the National Ignition Facility. Measurements begin approximately 20 s after shot time, and yields have been determined for nuclides with half-lives as short as tens of seconds. We determined the relative independent yields of 133mXe, 135Xe, and 135mXe to significantly higher precision than previously reported. The relative fission yields of all nuclides are statistically indistinguishable from values reported by England and Rider (ENDF-349. LA-UR-94-3106, 1994), with exception of the cumulative yield of 139Xe. Furthermore, considerablemore » differences exist between our measured yields and the JEFF-3.1 database values.« less

Heat Capacity Anomaly Near the Lower Critical Consolute Point of Triethylamine-Water

NASA Technical Reports Server (NTRS)

Flewelling, Anne C.; DeFonseka, Rohan J.; Khaleeli, Nikfar; Partee, J.; Jacobs, D. T.

1996-01-01

The heat capacity of the binary liquid mixture triethylamine-water has been measured near its lower critical consolute point using a scanning, adiabatic calorimeter. Two data runs are analyzed to provide heat capacity and enthalpy data that are fitted by equations with background terms and a critical term that includes correction to scaling. The critical exponent a was determined to be 0.107 +/- 0.006, consistent with theoretical predictions. When alpha was fixed at 0.11 to determine various amplitudes consistently, our values of A(+) and A(-) agreed with a previous heat capacity measurement, but the value of A(-) was inconsistent with values determined by density or refractive index measurements. While our value for the amplitude ratio A(+)/ A(-) = 0.56 +/- 0.02 was consistent with other recent experimental determinations in binary liquid mixtures, it was slightly larger than either theoretical predictions or recent experimental values in liquid-vapor systems. The correction to scaling amplitude ratio D(+)/D(-) = 0.5 +/- 0.1 was half of that predicted. As a result of several more precise theoretical calculations and experimental determinations, the two-scale-factor universality ratio X, which we found to be 0.019 +/- 0.003, now is consistent among experiments and theories. A new 'universal' amplitude ratio R(sup +/-)(sub Bcr) involving the amplitudes for the specific heat was tested. Our determination of R(sup +/-)(sub Bcr) = -0.5 +/- 0.1 and R(sup -)(sub Bcr) = 1.1 +/- 0.1 is smaller in magnitude than predicted and is the first such determination in a binary fluid mixture.

Administrative Compensation: An Investigation of Factors Accounting for Salary Differentials.

ERIC Educational Resources Information Center

Tracy, Saundra J.; Sheehan, Robert

A study was done to determine whether administrator salaries in 14 Ohio school districts were a reflection of administrator responsibilities or of length of service, and to find what factors accounted for salary differentials. Although previous research suggests factors for assigning value to administrative positions, traditional salary structures…

[Occupational risk as a criterion determining economic responsibility of employers].

PubMed

Subbotin, V V; Tkachev, V V

2003-01-01

The authors suggested a new method to calculate discounts and increments, value of assurance collection, that is based on differentiation of insurers, but not of economic branches. Occupational risk class should be set according to the previous results with consideration of work safety parameters described in the article.

An Evaluation of a Stimulus Preference Assessment of Auditory Stimuli for Adolescents with Developmental Disabilities

ERIC Educational Resources Information Center

Horrocks, Erin; Higbee, Thomas S.

2008-01-01

Previous researchers have used stimulus preference assessment (SPA) methods to identify salient reinforcers for individuals with developmental disabilities including tangible, leisure, edible and olfactory stimuli. In the present study, SPA procedures were used to identify potential auditory reinforcers and determine the reinforcement value of…

The effect of changing gravity and weightlessness of vasopressin control systems

NASA Technical Reports Server (NTRS)

Moran, W. H.

1972-01-01

An immunoassay to determine the effects of changing gravity and weightlessness on vasopressin control system is discussed. Seven extracts from persons known to have inappropriate ADH syndrome secondary to pulmonary oat cell cancer were examined. The extracts had previously been subject to bioassay in rats. The intent of the examination was to determine if the vasopressin content could be confirmed immunologically. The results compared favorably with the values obtained by biological assay.

Determination of gaseous fission product yields from 14 MeV neutron induced fission of 238U at the National Ignition Facility

DOE PAGES

Cassata, W. S.; Velsko, C. A.; Stoeffl, W.; ...

2016-01-14

We determined fission yields of xenon ( 133mXe, 135Xe, 135mXe, 137Xe, 138Xe, and 139Xe) resulting from 14 MeV neutron induced fission of depleted uranium at the National Ignition Facility. Measurements begin approximately 20 s after shot time, and yields have been determined for nuclides with half-lives as short as tens of seconds. We determined the relative independent yields of 133mXe, 135Xe, and 135mXe to significantly higher precision than previously reported. The relative fission yields of all nuclides are statistically indistinguishable from values reported by England and Rider (ENDF-349. LA-UR-94-3106, 1994), with exception of the cumulative yield of 139Xe. Furthermore, considerablemore » differences exist between our measured yields and the JEFF-3.1 database values.« less

Rapid determination of octanol-water partition coefficient using vortex-assisted liquid-liquid microextraction.

PubMed

Román, Iván P; Mastromichali, Anna; Tyrovola, Konstantina; Canals, Antonio; Psillakis, Elefteria

2014-02-21

Vortex-assisted liquid-liquid microextraction (VALLME) coupled with high-performance liquid chromatography (HPLC) is proposed here for the rapid determination of octanol-water partitioning coefficients (Kow). VALLME uses vortex agitation, a mild emulsification procedure, to disperse microvolumes of octanol in the aqueous phase thus increasing the interfacial contact area and ensuring faster partitioning rates. With VALLME, 2min were enough to achieve equilibrium conditions between the octanolic and aqueous phases. Upon equilibration, separation was achieved using centrifugation and the octanolic microdrop was collected and analyzed in a HPLC system. Six model compounds with logKow values ranging between ∼0.5 and 3.5 were used during the present investigations. The proposed method produced logKow values that were consistent with previously published values and the recorded uncertainty was well within the acceptable log unit range. Overall, the key features of the proposed Kow determination procedure comprised speed, reliability, simplicity, low cost and minimal solvent consumption. Copyright © 2014 Elsevier B.V. All rights reserved.

Receiver Operating Characteristic Curve Analysis of Beach Water Quality Indicator Variables

PubMed Central

Morrison, Ann Michelle; Coughlin, Kelly; Shine, James P.; Coull, Brent A.; Rex, Andrea C.

2003-01-01

Receiver operating characteristic (ROC) curve analysis is a simple and effective means to compare the accuracies of indicator variables of bacterial beach water quality. The indicator variables examined in this study were previous day's Enterococcus density and antecedent rainfall at 24, 48, and 96 h. Daily Enterococcus densities and 15-min rainfall values were collected during a 5-year (1996 to 2000) study of four Boston Harbor beaches. The indicator variables were assessed for their ability to correctly classify water as suitable or unsuitable for swimming at a maximum threshold Enterococcus density of 104 CFU/100 ml. Sensitivity and specificity values were determined for each unique previous day's Enterococcus density and antecedent rainfall volume and used to construct ROC curves. The area under the ROC curve was used to compare the accuracies of the indicator variables. Twenty-four-hour antecedent rainfall classified elevated Enterococcus densities more accurately than previous day's Enterococcus density (P = 0.079). An empirically derived threshold for 48-h antecedent rainfall, corresponding to a sensitivity of 0.75, was determined from the 1996 to 2000 data and evaluated to ascertain if the threshold would produce a 0.75 sensitivity with independent water quality data collected in 2001 from the same beaches. PMID:14602593

New Measurement of the 60Fe Half-Life.

PubMed

Rugel, G; Faestermann, T; Knie, K; Korschinek, G; Poutivtsev, M; Schumann, D; Kivel, N; Günther-Leopold, I; Weinreich, R; Wohlmuther, M

2009-08-14

We have made a new determination of the half-life of the radioactive isotope 60Fe using high precision measurements of the number of 60Fe atoms and their activity in a sample containing over 10(15) 60Fe atoms. Our new value for the half-life of 60Fe is (2.62+/-0.04) x 10(6) yr, significantly above the previously reported value of (1.49+/-0.27) x 10(6) yr. Our new measurement for the lifetime of 60Fe has significant implications for interpretations of galactic nucleosynthesis, for determinations of formation time scales of solids in the early Solar System, and for the interpretation of live 60Fe measurements from supernova-ejecta deposits on Earth.

Half-lives of 132La and 135La

NASA Astrophysics Data System (ADS)

Abel, E. P.; Clause, H. K.; Fonslet, J.; Nickles, R. J.; Severin, G. W.

2018-03-01

The half-lives of 135La and 132La were determined via serial gamma spectroscopy, and the half-life of 135La was further determined by a high-precision ionization-chamber measurement. The results are 18.91(2) hr for 135La and 4.59(4) hr for 132La compared with the previously compiled values of 19.5(2) hr and 4.8(2) hr, respectively. These lanthanum isotopes comprise a medically interesting system with positron emitter 132La and Auger-electron emitter 135La forming a theranostic pair for internal diagnostics and therapeutics. The precise half-lives are necessary for proper evaluation of their value in medicine and for a more representative tabulation of nuclear data.

Indirect Determination of the Thermodynamic Temperature of a Gold Fixed-Point Cell

NASA Astrophysics Data System (ADS)

Battuello, M.; Girard, F.; Florio, M.

2010-09-01

Since the value T 90(Au) was fixed on the ITS-90, some determinations of the thermodynamic temperature of the gold point have been performed which form, with other renormalized results of previous measurements by radiation thermometry, the basis for the current best estimates of ( T - T 90)Au = 39.9 mK as elaborated by the CCT-WG4. Such a value, even if consistent with the behavior of T - T 90 differences at lower temperatures, is quite influenced by the low values of T Au as determined with few radiometric measurements. At INRIM, an independent indirect determination of the thermodynamic temperature of gold was performed by means of a radiation thermometry approach. A fixed-point technique was used to realize approximated thermodynamic scales from the Zn point up to the Cu point. A Si-based standard radiation thermometer working at 900 nm and 950 nm was used. The low uncertainty presently associated to the thermodynamic temperature of fixed points and the accuracy of INRIM realizations, allowed scales with an uncertainty lower than 0.03 K in terms of the thermodynamic temperature to be realized. A fixed-point cell filled with gold, 99.999 % in purity, was measured, and its freezing temperature was determined by both interpolation and extrapolation. An average T Au = 1337.395 K was found with a combined standard uncertainty of 23 mK. Such a value is 25 mK higher than the presently available value as derived by the CCT-WG4 value of ( T - T 90)Au = 39.9 mK.

Effects of education and experience on nurses' value of ulcer prevention.

PubMed

Samuriwo, Ray

Few studies have focused on the value that nurses place on pressure ulcer prevention, even though values are a key determinant of a person's behaviour and actions. Previous studies have reported that the value that a nurse places on pressure ulcer prevention is linked to the skin care that they deliver. This article describes a study that was undertaken to determine the value that nurses place on pressure ulcer prevention, which also identified how this value is formed. The participants in this study (n=16), were recruited from non-acute adult medical wards of 14 hospitals in one NHS trust, and a university. Data was gathered via semi-structured interviews and interpreted through Straussian grounded theory. The findings of this study show how the participants underwent a transition from placing a low to a high value on pressure ulcer prevention and how this affected patient care. The key point in this transition appears to be an encounter with a patient with a high grade pressure ulcer, which caused the nurses to reappraise their values. Looking after patients with pressure ulcers seems to increase the value that a nurse places on pressure ulcer prevention. The education that nurses receive on pressure ulcer prevention only appears to alter their values when they have some experience of looking after patients with pressure ulcers.

The caffeine breath test and caffeine urinary metabolite ratios in the Michigan cohort exposed to polybrominated biphenyls: A preliminary study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lambert, G.H.; Schoeller, D.A.; Kotake, A.N.

1990-11-01

A field biochemical epidemiology study was conducted using the Michigan cohort consisting of 51 rural residents exposed to polybrominated biphenyls (PBB). The study had three major objectives: (a) to determine the serum half-life of the major PBB congener, hexabromobiphenyl (HBB), in the human, (b) to determine if the PBB-exposed subjects had elevated cytochrome P-450I function as determined by the caffeine breath test (CBT) and the caffeine urinary metabolite ratio (CMR), and (c) to determine the applicability of the CBT and CMR in field studies. PBB serum levels were detected in 36 of the 51 PBB-exposed subjects. The serum half-life ofmore » HBB was determined by comparing the current serum HBB values to the subject's previous serum values obtained 5 to 8 years earlier. The median HBB half-life was 12 years (range 4-97 years). The CBT and CMR were elevated in the subjects exposed to PBBs as compared to the values obtained from urban nonsmokers and were similar to those found in adults who smoke. A gender effect was seen in the PBB-exposed subjects. There was a correlation between the CBT and the HBB serum values but not between CMR and HBB serum values. The CBT and CMR were easily conducted in the field and appear to be useful metabolic probes of cytochrome P-450I activity in human environmental toxicology.« less

Temperature dependent lattice constant of InSb above room temperature

NASA Astrophysics Data System (ADS)

Breivik, Magnus; Nilsen, Tron Arne; Fimland, Bjørn-Ove

2013-10-01

Using temperature dependent X-ray diffraction on two InSb single crystalline substrates, the bulk lattice constant of InSb was determined between 32 and 325 °C. A polynomial function was fitted to the data: a(T)=6.4791+3.28×10-5×T+1.02×10-8×T2 Å (T in °C), which gives slightly higher values than previously published (which go up to 62 °C). From the fit, the thermal expansion of InSb was calculated to be α(T)=5.062×10-6+3.15×10-9×T K-1 (T in °C). We found that the thermal expansion coefficient is higher than previously published values above 100 °C (more than 10% higher at 325 °C).

The problem with value

PubMed Central

O’Doherty, John P.

2015-01-01

Neural correlates of value have been extensively reported in a diverse set of brain regions. However, in many cases it is difficult to determine whether a particular neural response pattern corresponds to a value-signal per se as opposed to an array of alternative non-value related processes, such as outcome-identity coding, informational coding, encoding of autonomic and skeletomotor consequences, alongside previously described “salience” or “attentional” effects. Here, I review a number of experimental manipulations that can be used to test for value, and I identify the challenges in ascertaining whether a particular neural response is or is not a value signal. Finally, I emphasize that some non-value related signals may be especially informative as a means of providing insight into the nature of the decision-making related computations that are being implemented in a particular brain region. PMID:24726573

Why I Believe I Achieve Determines Whether I Achieve

ERIC Educational Resources Information Center

Siegle, Del; McCoach, D. Betsy; Roberts, Anne

2017-01-01

The beliefs and values students hold toward themselves, given tasks, and achievement itself can influence what tasks students seek, and whether they are able to obtain them. On the basis of previous research on underachievement and motivation, we developed the Achievement Orientation Model (AOM) to explore the issue of student achievement. The…

Public Participation in Insect Research through the Use of Pheromones

ERIC Educational Resources Information Center

Harvey, Deborah; Hedenström, Erik; Finch, Paul

2017-01-01

In a project to determine the UK distribution of a conservation-status beetle "Elater ferrugineus", 300 volunteers were recruited and supplied with traps containing a female pheromone that is an effective attractant for adult males. The occurrence and distribution of the insect were extended from previously estimated values and shown to…

STUDY OF VARIABLES ASSOCIATED WITH FINAL GRADES IN MATHEMATICS COURSES.

ERIC Educational Resources Information Center

DAVIS, ELTON C.; RISSER, JOHN J.

THIS STUDY WAS CONDUCTED IN ORDER TO DETERMINE THE RELATIVE VALUE OF PREVIOUS GRADES IN MATHEMATICS COURSES, THE OVERALL HIGH SCHOOL GRADE POINT AVERAGE, AND THE PLACEMENT TEST IN MATHEMATICS DEVELOPED AT THE COLLEGE AS PREDICTORS OF ACHIEVEMENT IN INTRODUCTORY AND INTERMEDIATE ALGEBRA, IN COLLEGE ALGEBRA, IN TRIGONOMETRY, AND IN ANALYTIC GEOMETRY…

Half-lives of 101Rh g and 108Ag m

DOE PAGES

Shugart, Howard A.; Browne, Edgardo; Norman, Eric B.

2018-02-20

Using long-term gamma-ray spectroscopy with high resolution germanium detectors and a ratio method, the half-lives of 101Rh g and 108Ag m have been determined to be 4.07 ± 0.05 years and 448 ± 27 years, respectively. These results are then compared with previously reported values.

NONINTELLECTIVE VARIABLES RELATED TO ACADEMIC ACHIEVEMENT OF BRIGHT JUNIOR HIGH SCHOOL BOYS.

ERIC Educational Resources Information Center

RINGNESS, THOMAS A.

IN PREVIOUS STUDIES, A NUMBER OF PERSONALITY VARIABLES, INCLUDING ADJUSTMENT, MOTIVE-TO-ACHIEVE, MOTIVE-TO-AFFILIATE, ACCEPTANCE OF SELF AND OTHERS, AND ACCEPTANCE OF ADULT VALUES HAVE BEEN STUDIED TO DETERMINE THEIR RELATIONSHIPS TO SCHOOL ACHIEVEMENT. INTERRELATIONSHIPS AMONG THESE VARIABLES WERE EXAMINED IN THIS STUDY. THE CALIFORNIA TEST OF…

Half-lives of 101Rh g and 108Ag m

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shugart, Howard A.; Browne, Edgardo; Norman, Eric B.

Using long-term gamma-ray spectroscopy with high resolution germanium detectors and a ratio method, the half-lives of 101Rh g and 108Ag m have been determined to be 4.07 ± 0.05 years and 448 ± 27 years, respectively. These results are then compared with previously reported values.

Half-lives of 101 Rh g and 108 Ag m

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shugart, H.; Browne, E.; Norman, E.

Using long-term gamma-ray spectroscopy with high resolution germanium detectors and a ratio method, the half-lives of 101Rhg and 108Agm have been determined to be 4.07 ± 0.05 years and 448 ± 27 years, respectively. These results are compared with previously reported values.

Branch breakage under snow and ice loads.

PubMed

Cannell, M G; Morgan, J

1989-09-01

Measurements were made on branches and trunks of Picea sitchensis (Bong.) Carr. to determine the relationship between (i) the bending moment at the bases of branches that cause breakage, and (ii) midpoint diameter cubed. The theory for cantilever beams was then used to calculate the basal bending moments and midpoint diameters of branches with different numbers of laterals and endpoint deflections, given previously measured values of Young's modulus, taper and weights of foliage and wood. Snow and ice loads (equal to 2 and 4 g cm(-1) of shoot, respectively) were then included in the calculation to determine whether the basal bending moments exceeded the breakage values. The likelihood of breakage increased with an increase in (i) number of laterals, and (ii) endpoint deflection under self weight (without snow or ice)-features that had previously been shown to lessen the amount of branch wood required to support a unit of foliage. However, branches which deflected moderately (> 10% of their length) under their own weight deflected greatly under snow or ice loads and might shed powdery snow before breakage occurs.

Precision Effects for Solar Image Coordinates Within the FITS World Coordinate System

NASA Technical Reports Server (NTRS)

Thompson, W. T.

2010-01-01

The FITS world coordinate system (WCS) provides a number of tools for precisely specifying the spatial coordinates of an image. Many of the finer details that the WCS addresses have not historically been taken into account in solar image processing. This paper examines various effects which can affect the expression of coordinates in FITS headers, to determine under what conditions such effects need to be taken into account in data analysis, and under what conditions they can be safely ignored. Effects which are examined include perspective, parallax, spherical projection, optical axis determination, speed-of-light effects, stellar aberration, gravitational deflection, and scattering and refraction at radio wavelengths. Purely instrumental effects, such as misalignment or untreated optical aberrations, are not considered. Since the value of the solar radius is an experimental quantity, the effect of adopting a specific radius value is also examined. These effects are examined in the context of a previous paper outlining a WCS standard for encoding solar coordinates in FITS files. Aspects of that previous paper are clarified and extended in the present work.

Precise Measurements of the Masses of Cs, Rb and Na A New Route to the Fine Structure Constant

NASA Astrophysics Data System (ADS)

Rainville, Simon; Bradley, Michael P.; Porto, James V.; Thompson, James K.; Pritchard, David E.

2001-01-01

We report new values for the atomic masses of the alkali 133Cs, 87Rb, 85Rb, and 23Na with uncertainties ≤ 0.2 ppb. These results, obtained using Penning trap single ion mass spectrometry, are typically two orders of magnitude more accurate than previously measured values. Combined with values of h/m atom from atom interferometry measurements and accurate wavelength measurements for different atoms, these values will lead to new ppb-level determinations of the molar Planck constant N A h and the fine structure constant α. This route to α is based on simple physics. It can potentially achieve the several ppb level of accuracy needed to test the QED determination of α extracted from measurements of the electron g factor. We also demonstrate an electronic cooling technique that cools our detector and ion below the 4 K ambient temperature. This technique improves by about a factor of three our ability to measure the ion's axial motion.

Tmax Determined Using a Bayesian Estimation Deconvolution Algorithm Applied to Bolus Tracking Perfusion Imaging: A Digital Phantom Validation Study.

PubMed

Uwano, Ikuko; Sasaki, Makoto; Kudo, Kohsuke; Boutelier, Timothé; Kameda, Hiroyuki; Mori, Futoshi; Yamashita, Fumio

2017-01-10

The Bayesian estimation algorithm improves the precision of bolus tracking perfusion imaging. However, this algorithm cannot directly calculate Tmax, the time scale widely used to identify ischemic penumbra, because Tmax is a non-physiological, artificial index that reflects the tracer arrival delay (TD) and other parameters. We calculated Tmax from the TD and mean transit time (MTT) obtained by the Bayesian algorithm and determined its accuracy in comparison with Tmax obtained by singular value decomposition (SVD) algorithms. The TD and MTT maps were generated by the Bayesian algorithm applied to digital phantoms with time-concentration curves that reflected a range of values for various perfusion metrics using a global arterial input function. Tmax was calculated from the TD and MTT using constants obtained by a linear least-squares fit to Tmax obtained from the two SVD algorithms that showed the best benchmarks in a previous study. Correlations between the Tmax values obtained by the Bayesian and SVD methods were examined. The Bayesian algorithm yielded accurate TD and MTT values relative to the true values of the digital phantom. Tmax calculated from the TD and MTT values with the least-squares fit constants showed excellent correlation (Pearson's correlation coefficient = 0.99) and agreement (intraclass correlation coefficient = 0.99) with Tmax obtained from SVD algorithms. Quantitative analyses of Tmax values calculated from Bayesian-estimation algorithm-derived TD and MTT from a digital phantom correlated and agreed well with Tmax values determined using SVD algorithms.

An accurate redetermination of the 118Sn binding energy

NASA Astrophysics Data System (ADS)

Borzakov, S. B.; Chrien, R. E.; Faikow-Stanczyk, H.; Grigoriev, Yu. V.; Panteleev, Ts. Ts.; Pospisil, S.; Smotritsky, L. M.; Telezhnikov, S. A.

2002-03-01

The energy of well-known strong γ line from 198Au, the "gold standard", has been modified in the light of new adjustments in the fundamental constants and the value of 411.80176(12) keV was determined, which is 0.29 eV lower than the latest 1999 value. An energy calibration procedure for determining the neutron binding energy, Bn, from complicated (n, γ) spectra has been developed. A mathematically simple minimization function consisting only of terms having as parameters the coefficients of the energy calibration curve (polynomial) is used. A priori information about the relationships among the energies of different peaks on the spectrum is taken into account by a Monte-Carlo simulation. The procedure was used in obtaining Bn for 118Sn. The γ-ray spectrum from thermal neutron radiative capture by 117Sn has been measured on the IBR-2 pulsed reactor. γ-rays were detected by a 72 cm 3 HPGe detector. For a better determination of Bn it was important to determine Bn for 64Cu. This value was obtained from two γ-spectra. One spectrum was measured on the IBR-2 by the same detector. The other spectrum was measured with a pair spectrometer at the Brookhaven High Flux Beam Reactor. From these two spectra, Bn for 64Cu was determined to be equal to 7915.52(8) keV. This result essentially differs from the previous value of 7915.96(11) keV. The mean value of the two most precise results of the Bn for 118Sn, was determined to be 9326.35(9) keV. The Bn for 57Fe was determined to be 7646.08(9) keV.

Veterinary software application for comparison of thermograms for pathology evaluation

NASA Astrophysics Data System (ADS)

Pant, Gita; Umbaugh, Scott E.; Dahal, Rohini; Lama, Norsang; Marino, Dominic J.; Sackman, Joseph

2017-09-01

The bilateral symmetry property in mammals allows for the detection of pathology by comparison of opposing sides. For any pathological disorder, thermal patterns differ compared to the normal body part. A software application for veterinary clinics has been under development to input two thermograms of body parts on both sides, one normal and the other unknown, and the application compares them based on extracted features and appropriate similarity and difference measures and outputs the likelihood of pathology. Here thermographic image data from 19° C to 40° C was linearly remapped to create images with 256 gray level values. Features were extracted from these images, including histogram, texture and spectral features. The comparison metrics used are the vector inner product, Tanimoto, Euclidean, city block, Minkowski and maximum value metric. Previous research with the anterior cruciate ligament (ACL) pathology in dogs suggested any thermogram variation below a threshold of 40% of Euclidean distance is normal and above 40% is abnormal. Here the 40% threshold was applied to a new ACL image set and achieved a sensitivity of 75%, an improvement from the 55% sensitivity of the previous work. With the new data set it was determined that using a threshold of 20% provided a much improved 92% sensitivity metric. However, this will require further research to determine the corresponding specificity success rate. Additionally, it was found that the anterior view provided better results than the lateral view. It was also determined that better results were obtained with all three feature sets than with just the histogram and texture sets. Further experiments are ongoing with larger image datasets, and pathologies, new features and comparison metric evaluation for determination of more accurate threshold values to separate normal and abnormal images.

Quantitative In Vivo Fluorescence Cross-Correlation Analyses Highlight the Importance of Competitive Effects in the Regulation of Protein-Protein Interactions

PubMed Central

Sadaie, Wakako; Harada, Yoshie; Matsuda, Michiyuki

2014-01-01

Computer-assisted simulation is a promising approach for clarifying complicated signaling networks. However, this approach is currently limited by a deficiency of kinetic parameters determined in living cells. To overcome this problem, we applied fluorescence cross-correlation spectrometry (FCCS) to measure dissociation constant (Kd) values of signaling molecule complexes in living cells (in vivo Kd). Among the pairs of fluorescent molecules tested, that of monomerized enhanced green fluorescent protein (mEGFP) and HaloTag-tetramethylrhodamine was most suitable for the measurement of in vivo Kd by FCCS. Using this pair, we determined 22 in vivo Kd values of signaling molecule complexes comprising the epidermal growth factor receptor (EGFR)–Ras–extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP) kinase pathway. With these parameters, we developed a kinetic simulation model of the EGFR-Ras-ERK MAP kinase pathway and uncovered a potential role played by stoichiometry in Shc binding to EGFR during the peak activations of Ras, MEK, and ERK. Intriguingly, most of the in vivo Kd values determined in this study were higher than the in vitro Kd values reported previously, suggesting the significance of competitive bindings inside cells. These in vivo Kd values will provide a sound basis for the quantitative understanding of signal transduction. PMID:24958104

Extraction-Scrub-Strip test results from the interim Salt Disposition Program Macrobatch 9 Tank 21H qualification samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T.

2016-02-23

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 9 for the Interim Salt Disposition Program (ISDP). The Salt Batch 9 characterization results were previously reported. An Extraction-Scrub-Strip (ESS) test was performed to determine cesium distribution ratios (D (Cs)) and cesium concentration in the strip effluent and decontaminated salt solution (DSS) streams; this data will be used by Tank Farm Engineering to project a cesium decontamination factor (DF). This test used actual Tank 21H material, and a blend solvent prepared by SRNL that mimics the solvent composition currently being used atmore » the Modular Caustic-Side Solvent Extraction Unit (MCU). The ESS test showed acceptable performance with an extraction D (Cs) value of 52.4. This value is consistent with results from previous salt batch ESS tests using similar solvent formulations. This compares well against the predicted value of 56.5 from a recently created D (Cs) model« less

Extraction, -scrub, -strip test results from the interim salt disposition program macrobatch 10 tank 21H qualification samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T. B.

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 10 for the Interim Salt Disposition Program (ISDP). The Salt Batch 10 characterization results were previously reported.ii,iii An Extraction, -Scrub, -Strip (ESS) test was performed to determine cesium distribution ratios (D(Cs)) and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Tank Farm Engineering to project a cesium decontamination factor (DF). This test used actual Tank 21H material, and a sample of the NGS Blend solvent currently being used at the Modularmore » Caustic-Side Solvent Extraction Unit (MCU). The ESS test showed acceptable performance with an extraction D(Cs) value of 110. This value is consistent with results from previous salt batch ESS tests using similar solvent formulations. This is better than the predicted value of 39.8 from a recently created D(Cs) model.« less

Rejection of reclassification of Lactobacillus kimchii and Lactobacillus bobalius as later subjective synonyms of Lactobacillus paralimentarius using comparative genomics.

PubMed

Yang, Seung-Jo; Kim, Byung-Yong; Chun, Jongsik

2017-11-01

Lactobacillus bobalius, Lactobacillus kimchii and Lactobacillus paralimentarius belong to the genus Lactobacillus and show close phylogenetic relationships. In a previous study, L. bobalius and L. kimchii were proposed to be reclassified as later heterotypic synonyms of L. paralimentarius using high 16S rRNA gene sequence similarities (≥99.5 %) and DNA-DNA hybridization values (≥82 %). We determined high quality whole genome assemblies of the type strains of L. bobalius and L. kimchii, which were then compared with that of L. paralimentarius. Average nucleotide identity values among three genomes ranged from 91.4 to 92.3 % which are clearly below 95~96 %, the generally recognized cutoff value for bacterial species boundaries. On the basis of comparative genomic evidence, L. bobalius, L. kimchii, and L. paralimentarius should stand as separate species in the genus Lactobacillus. We therefore suggest rejecting the previous proposal to combine these three species into a single species.

Hydrodynamic aspects of shark scales

NASA Technical Reports Server (NTRS)

Raschi, W. G.; Musick, J. A.

1986-01-01

Ridge morphometrices on placoid scales from 12 galeoid shark species were examined in order to evaluate their potential value for frictional drag reduction. The geometry of the shark scales is similar to longitudinal grooved surfaces (riblets) that have been previously shown to give 8 percent skin-friction reduction for turbulent boundary layers. The present study of the shark scales was undertaken to determine if the physical dimensions of the ridges on the shark scales are of the right magnitude to be used by the sharks for drag reduction based on previous riblet work. The results indicate that the ridge heights and spacings are normally maintained between the predicted optimal values proposed for voluntary and burst swimming speeds throughout the individual's ontogeny. Moreover, the species which might be considered to be the faster posses smaller and more closely spaced ridges that based on the riblet work would suggest a greater frictional drag reduction value at the high swimming speeds, as compared to their more sluggish counterparts.

A refined 'standard' thermal model for asteroids based on observations of 1 Ceres and 2 Pallas

NASA Technical Reports Server (NTRS)

Lebofsky, Larry A.; Sykes, Mark V.; Tedesco, Edward F.; Veeder, Glenn J.; Matson, Dennis L.

1986-01-01

An analysis of ground-based thermal IR observations of 1 Ceres and 2 Pallas in light of their recently determined occultation diameters and small amplitude light curves has yielded a new value for the IR beaming parameter employed in the standard asteroid thermal emission model which is significantly lower than the previous one. When applied to the reduction of thermal IR observations of other asteroids, this new value is expected to yield model diameters closer to actual values. The present formulation incorporates the IAU magnitude convention for asteroids that employs zero-phase magnitudes, including the opposition effect.

Numerical analysis of the asymptotic two-point boundary value solution for N-body trajectories.

NASA Technical Reports Server (NTRS)

Lancaster, J. E.; Allemann, R. A.

1972-01-01

Previously published asymptotic solutions for lunar and interplanetary trajectories have been modified and combined to formulate a general analytical boundary value solution applicable to a broad class of trajectory problems. In addition, the earlier first-order solutions have been extended to second-order to determine if improved accuracy is possible. Comparisons between the asymptotic solution and numerical integration for several lunar and interplanetary trajectories show that the asymptotic solution is generally quite accurate. Also, since no iterations are required, a solution to the boundary value problem is obtained in a fraction of the time required for numerically integrated solutions.

Scale Determinants of Fiscal Investment in Geological Exploration: Evidence from China

PubMed Central

Lu, Linna; Lei, Yalin

2013-01-01

With the continued growth in demand for mineral resources and China's efforts in increasing investment in geological prospecting, fiscal investment in geological exploration becomes a research hotspot. This paper examines the yearly relationship among fiscal investment in geological exploration of the current term, that of the last term and prices of mining rights over the period 1999–2009. Hines and Catephores' investment acceleration model is applied to describe the scale determinants of fiscal investment in geological exploration which are value-added of mining rights, value of mining rights and fiscal investment in the last term. The results indicate that when value-added of mining rights, value of mining rights or fiscal investment in the last term moves at 1 unit, fiscal investment in the current term will move 0.381, 1.094 or 0.907 units respectively. In order to determine the scale of fiscal investment in geological exploration for the current year, the Chinese government should take fiscal investment in geological exploration for the last year and the capital stock of the previous investments into account. In practice, combination of government fiscal investment in geological exploration with its performance evaluation can create a virtuous circle of capital management mechanism. PMID:24204652

Scale determinants of fiscal investment in geological exploration: evidence from China.

PubMed

Lu, Linna; Lei, Yalin

2013-01-01

With the continued growth in demand for mineral resources and China's efforts in increasing investment in geological prospecting, fiscal investment in geological exploration becomes a research hotspot. This paper examines the yearly relationship among fiscal investment in geological exploration of the current term, that of the last term and prices of mining rights over the period 1999-2009. Hines and Catephores' investment acceleration model is applied to describe the scale determinants of fiscal investment in geological exploration which are value-added of mining rights, value of mining rights and fiscal investment in the last term. The results indicate that when value-added of mining rights, value of mining rights or fiscal investment in the last term moves at 1 unit, fiscal investment in the current term will move 0.381, 1.094 or 0.907 units respectively. In order to determine the scale of fiscal investment in geological exploration for the current year, the Chinese government should take fiscal investment in geological exploration for the last year and the capital stock of the previous investments into account. In practice, combination of government fiscal investment in geological exploration with its performance evaluation can create a virtuous circle of capital management mechanism.

The electrical conductivity of in vivo human uterine fibroids.

PubMed

DeLonzor, Russ; Spero, Richard K; Williams, Joseph J

2011-01-01

The purpose of this study was to determine the value of electrical conductivity that can be used for numerical modelling in vivo radiofrequency ablation (RFA) treatments of human uterine fibroids. No experimental electrical conductivity data have previously been reported for human uterine fibroids. In this study electrical data (voltage) from selected in vivo clinical procedures on human uterine fibroids were used to numerically model the treatments. Measured versus calculated power dissipation profiles were compared to determine uterine fibroid electrical conductivity. Numerical simulations were conducted utilising a wide range of values for tissue thermal conductivity, heat capacity and blood perfusion coefficient. The simulations demonstrated that power dissipation was insensitive to the exact values of these parameters for the simulated geometry, treatment duration, and power level. Consequently, it was possible to determine tissue electrical conductivity without precise knowledge of the values for these parameters. Results of this study showed that an electrical conductivity for uterine fibroids of 0.305 S/m at 37°C and a temperature coefficient of 0.2%/°C can be used for modelling Radio Frequency Ablation of human uterine fibroids at a frequency of 460 kHz for temperatures from 37°C to 100°C.

Gravitational parameters of the Jupiter system from the Doppler tracking of Pioneer 10

NASA Technical Reports Server (NTRS)

Anderson, J. D.; Null, G. W.; Wong, S. K.

1974-01-01

Preliminary analyses of Doppler data from Pioneer 10 during its encounter with Jupiter indicate that the mass of Io is about 20% greater than previously thought and that Io's mean density is about 3.5 grams per cubic centimeter. A determination of the dynamical flattening of Jupiter (a - b)/a (where a is the semimajor axis and b is the semiminor axis) is found to lie in the neighborhood of 0.065, which agrees with the value determined from satellite perturbations.

Influence of Temperature, Relative Humidity, and Soil Properties on the Soil-Air Partitioning of Semivolatile Pesticides: Laboratory Measurements and Predictive Models.

PubMed

Davie-Martin, Cleo L; Hageman, Kimberly J; Chin, Yu-Ping; Rougé, Valentin; Fujita, Yuki

2015-09-01

Soil-air partition coefficient (Ksoil-air) values are often employed to investigate the fate of organic contaminants in soils; however, these values have not been measured for many compounds of interest, including semivolatile current-use pesticides. Moreover, predictive equations for estimating Ksoil-air values for pesticides (other than the organochlorine pesticides) have not been robustly developed, due to a lack of measured data. In this work, a solid-phase fugacity meter was used to measure the Ksoil-air values of 22 semivolatile current- and historic-use pesticides and their degradation products. Ksoil-air values were determined for two soils (semiarid and volcanic) under a range of environmentally relevant temperature (10-30 °C) and relative humidity (30-100%) conditions, such that 943 Ksoil-air measurements were made. Measured values were used to derive a predictive equation for pesticide Ksoil-air values based on temperature, relative humidity, soil organic carbon content, and pesticide-specific octanol-air partition coefficients. Pesticide volatilization losses from soil, calculated with the newly derived Ksoil-air predictive equation and a previously described pesticide volatilization model, were compared to previous results and showed that the choice of Ksoil-air predictive equation mainly affected the more-volatile pesticides and that the way in which relative humidity was accounted for was the most critical difference.

10 CFR 431.264 - Uniform test method for the measurement of flow rate for commercial prerinse spray valves.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., the water consumption flow rate of commercial prerinse spray valves. (b) Testing and Calculations. The test procedure to determine the water consumption flow rate for prerinse spray valves, expressed in... the previous step. Round the final water consumption value to one decimal place as follows: (1) A...

The Value of Academic Libraries: Library Services as a Predictor of Student Retention

ERIC Educational Resources Information Center

Murray, Adam; Ireland, Ashley; Hackathorn, Jana

2016-01-01

This study examined the predictive relationship between library use by individual students and their retention status in university settings. The methodology builds on a small number of previous studies to examine library use at the individual level to determine if use of specific library services is predictive of retention for freshmen and…

Trajectories of Anxiety during Elementary-School Years and the Prediction of High School Noncompletion

ERIC Educational Resources Information Center

Duchesne, Stephane; Vitaro, Frank; Larose, Simon; Tremblay, Richard E.

2008-01-01

Previous research has provided mixed results regarding the effect of anxiety on academic achievement. Building on this body of research, the present longitudinal study pursued two goals. The first goal was to describe trajectories of anxiety during elementary-school years. The second goal was to determine the predictive value of these trajectories…

A reassessment of the compressive strength properties of southern yellow pine bark

Treesearch

Thomas L. Eberhardt

2007-01-01

Samples of southern yellow pine outer bark and wood were tested in compression to determine values for modulus of elasticity, stress at proportional limit, and maximum crushing strength. Results reported here resolve inconsistencies in the compressive strength data previously reported by others for pine bark. Testing of solvent-treated bark blocks suggests that...

Abnormal cerebrospinal fluid protein indices in schizophrenia.

PubMed

Kirch, D G; Kaufmann, C A; Papadopoulos, N M; Martin, B; Weinberger, D R

1985-10-01

Determinations of albumin and immunoglobulin G (IgG) were performed in paired cerebrospinal fluid (CSF) and serum samples from 24 subjects with schizophrenia. These determinations allowed calculation of two indices, one that is an indicator of integrity of the blood-brain barrier and the other a measure of selective IgG production within the central nervous system (CNS). In comparison with previously determined reference values, 7 of 24 (29%) subjects showed increased blood-brain barrier permeability, and 8 of 24 (33%) demonstrated elevated endogenous CNS IgG production. One of these eight also demonstrated oligoclonal banding on high-resolution protein electrophoresis of the CSF.

Novel measuring strategies in neutron interferometry

NASA Astrophysics Data System (ADS)

Bonse, Ulrich; Wroblewski, Thomas

1985-04-01

Angular misalignment of a sample in a single crystal neutron interferometer leads to systematic errors of the effective sample thickness and in this way to errors in the determination of the coherent scattering length. The misalignment can be determined and the errors can be corrected by a second measurement at a different angular sample position. Furthermore, a method has been developed which allows supervision of the wavelength during the measurements. These two techniques were tested by determining the scattering length of copper. A value of bc = 7.66(4) fm was obtained which is in excellent agreement with previous measurements.

Determination of as-discarded methane potential in residential and commercial municipal solid waste.

PubMed

Chickering, Giles W; Krause, Max J; Townsend, Timothy G

2018-06-01

Methane generation potential, L 0 , is a primary parameter of the first-order decay (FOD) model used for prediction and regulation of landfill gas (LFG) generation in municipal solid waste (MSW) landfills. The current US EPA AP-42 default value for L 0 , which has been in place for almost 20 years, is 100 m 3 CH 4 /Mg MSW as-discarded. Recent research suggests the yield of landfilled waste could be less than 60 m 3 CH 4 /Mg MSW. This study aimed to measure the L 0 of present-day residential and commercial as-discarded MSW. In doing so, 39 waste collection vehicles were sorted for composition before samples of each biodegradable fraction were analyzed for methane generation potential. Methane yields were determined for over 450 samples of 14 different biodegradable MSW fractions, later to be combined with moisture content and volatile solids data to calculate L 0 values for each waste load. An average value of 80 m 3 CH 4 /Mg MSW was determined for all samples with 95% of values in the interval 74-86 m 3 CH 4 /Mg MSW as-discarded. While no statistically significant difference was observed, commercial MSW yields (mean 85, median 88 m 3 CH 4 /Mg MSW) showed a higher average L 0 than residential MSW (mean 75, median 71 m 3 CH 4 /Mg MSW). Many methane potential values for individual fractions described in previous work were found within the range of values determined by BMP in this study. Copyright © 2018 Elsevier Ltd. All rights reserved.

I/O values for determination of the origin of some indoor organic pollutants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Otson, R.; Zhu, J.

To reduce human health risks resulting from exposure to toxic chemicals, it is important to determine the origin of such substances. The ratio (I/O) of indoor to outdoor concentrations of selected airborne vapor phase organic compounds (VPOC) was used to estimate the contribution of indoor sources to levels of the compounds in the air of 44 homes selected randomly in the Greater Toronto Area (GTA). Average I/O values for all of the homes were greater 1.5 for 10 of the 20 detected target compounds, and it could be concluded that indoor VPOC sources had a greater impact on indoor airmore » quality than outdoor air in these instances. A significant finding, which aptly demonstrates the importance of indoor sources and pollution, was the overall I/O value of 5.2 for the 44 representative GTA homes. Possible indoor sources for most of the 10 compounds could be identified, based on information collected by means of a questionnaire, as well as from the scientific literature. However, possible sources for some compounds could not be determined as readily, probably because of the presence of multiple sources, and sources which had not been previously noted, such as foods and beverages. The sensitivity of I/O values to various factors (e.g., source strength, air exchange rates, precision of measurements, unanticipated sources), and the reliability of determining the origin of pollutants by use of I/O values alone were examined, with some examples. If used judiciously, the I/O value can be a useful tool for IAQ investigations.« less

[Effects of hyposalinity in Thalassia testudinum (Hydrocharitaceae) from Parque Nacional Morrocoy, Venezuela].

PubMed

Pérez, D; Galindo, L

2000-12-01

The year 1996 had a high pluviosity in Morrocoy National Park (western coastal zone, Venezuela) and low salinity in December 1996 affected the seagrass beds, dominated by Thalassia testudinum. Patches without T. testudinum were observed in localities of the park that used to have very dense populations of this plant. Sampling was done at Las Luisas to determine leaf productivity, turnover rate, short shoot density and relative biomass of plant sections, in order to compare with data obtained in September 1996, previous to the event. Green leaves, roots and rhizomes were the most affected parts. Mean green leaf biomass decreased in January and February 1997 to 5% of the plant's total biomass; mean root biomass decreased in March to 40% and mean rhi zome biomass decreased in February to 30%. The density of the active short shoots decreased to a minimum in February, but in April it reached a value similar to that of September 1996. The density of the inactive short shoots decreased to a minimum in March, and they dissappeared in April, matching the increasing density of the active short shoots between these two months. In February 1997, 56% of the inactive short shoots showed evidence of leaf initiation. In January 1997 the leaf productivity and turnover rate values (2.72 +/- 0.35 g/m2/d and 2.15% leaf DW/d) were similar to the annual mean previously determined from Las Luisas (2.35 +/- 0.72 g/m2/d and 1.96% leaf DW/d). Nevertheless, the values of productivity and turnover rate detected at Las Luisas in April 1997 (4.88 +/- 2.14 g/m2/d and 4.66% leaf DW/d) were higher than those values previously reported for this location. In response to the mortality episode, the leaf productivity and turnover rate of T. testudinum increased and the leaf initiation was activated in the inactive short shoots.

Digital gate pulse generator for cycloconverter control

DOEpatents

Klein, Frederick F.; Mutone, Gioacchino A.

1989-01-01

The present invention provides a digital gate pulse generator which controls the output of a cycloconverter used for electrical power conversion applications by determining the timing and delivery of the firing pulses to the switching devices in the cycloconverter. Previous gate pulse generators have been built with largely analog or discrete digital circuitry which require many precision components and periodic adjustment. The gate pulse generator of the present invention utilizes digital techniques and a predetermined series of values to develop the necessary timing signals for firing the switching device. Each timing signal is compared with a reference signal to determine the exact firing time. The present invention is significantly more compact than previous gate pulse generators, responds quickly to changes in the output demand and requires only one precision component and no adjustments.

Solubility Control of Technetium Release from Saltstone by Tc02•xH20

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cantrell, Kirk J.; Williams, Benjamin D.

2013-11-12

Saltstone leaching experiments were conducted using a modified single-pass flow-through method under anoxic conditions. The analytical results of leachates collected from these experiments were evaluated using thermodynamic modeling to determine if the data were consistent with potential solubility controlling phases. The results demonstrate that technetium concentrations in water in contact with Saltstone under anoxic conditions is controlled by the solubility of TcO2•xH2O (likely TcO2•1.6H2O). In our system equilibrium solubility appears to have been reached within two weeks at a concentration of approximately 1.5 x 10-6 M. This concentration is likely to vary as the composition of Saltstone pore fluid evolvesmore » over time. As the pH goes from the initial high values (~12.5-13) to lower values, the solubility of technetium will decrease significantly. The thermodynamic data used to determine the solubility of TcO2•1.6H2O were taken from the tabulation of critically selected thermodynamic data determined by the Nuclear Energy Agency. Solid phase characterization to demonstrate the presence of TcO2•xH2O was not possible due to the low concentrations of technetium in our samples. Previous solid phase characterization studies with cementitious waste forms that were very similar to our Saltstone samples as well as reaction products derived from reductive immobilization of TcO4- by amorphous FeS clearly indicate the presence of TcO2 with varying degrees of hydration. Although, the presence of TcSx or other reduced technetium sulfide phases in our samples cannot be ruled out, release of technetium from Saltstone will be controlled by TcO2•1.6H2O because of its higher solubility. Our results clearly demonstrate that the release mechanism of technetium from Saltstone under reducing conditions is solubility controlled by TcO2•xH2O (likely TcO2•1.6H2O); however, distribution coefficients (Kds), that describe sorption and not solubility, were calculated for comparison with past literature values. After 84 days of reaction under anoxic conditions, the average Kd value for technetium was determined to be 610 mL/g. This value is similar to a value determined previously for a similar saltstone sample under reducing conditions at 56 days (712 ± 81 mL/g).« less

Determination of the soil hazardous concentrations of bisphenol A using the species sensitivity approach.

PubMed

Kwak, Jin Il; Moon, Jongmin; Kim, Dokyung; Cui, Rongxue; An, Youn-Joo

2018-02-15

This study describes the determination of the species sensitivity distribution (SSD)-based soil hazardous contamination of bisphenol A for environmental risk assessment. We conducted a battery of bioassays, including acute assays using eight species from six different taxonomic groups and chronic assays using five species from four different taxonomic groups. We determined that our dataset satisfied Australia & New Zealand's guidelines for applying the SSD methodology. Finally, the chronic soil HC 5 and HC 50 values for bisphenol A were estimated to be 13.7 and 74.7mg/kg soil, respectively, for soil ecosystem protection against chronic exposure using the data generated from this and previous studies. Because the soil standard values of bisphenol A for protection of the soil ecosystem are not currently available, the HC values of bisphenol A that we suggested based on the SSD approach would be applied as fundamental data to establish soil standards of bisphenol A for soil ecosystem protection. To our knowledge, this is the first study reporting the soil hazardous concentration of bisphenol A for environmental risk assessment. Copyright © 2017 Elsevier B.V. All rights reserved.

Return period adjustment for runoff coefficients based on analysis in undeveloped Texas watersheds

USGS Publications Warehouse

Dhakal, Nirajan; Fang, Xing; Asquith, William H.; Cleveland, Theodore G.; Thompson, David B.

2013-01-01

The rational method for peak discharge (Qp) estimation was introduced in the 1880s. The runoff coefficient (C) is a key parameter for the rational method that has an implicit meaning of rate proportionality, and the C has been declared a function of the annual return period by various researchers. Rate-based runoff coefficients as a function of the return period, C(T), were determined for 36 undeveloped watersheds in Texas using peak discharge frequency from previously published regional regression equations and rainfall intensity frequency for return periods T of 2, 5, 10, 25, 50, and 100 years. The C(T) values and return period adjustments C(T)/C(T=10  year) determined in this study are most applicable to undeveloped watersheds. The return period adjustments determined for the Texas watersheds in this study and those extracted from prior studies of non-Texas data exceed values from well-known literature such as design manuals and textbooks. Most importantly, the return period adjustments exceed values currently recognized in Texas Department of Transportation design guidance when T>10  years.

Determination of mouse skeletal muscle architecture using three-dimensional diffusion tensor imaging.

PubMed

Heemskerk, Anneriet M; Strijkers, Gustav J; Vilanova, Anna; Drost, Maarten R; Nicolay, Klaas

2005-06-01

Muscle architecture is the main determinant of the mechanical behavior of skeletal muscles. This study explored the feasibility of diffusion tensor imaging (DTI) and fiber tracking to noninvasively determine the in vivo three-dimensional (3D) architecture of skeletal muscle in mouse hind leg. In six mice, the hindlimb was imaged with a diffusion-weighted (DW) 3D fast spin-echo (FSE) sequence followed by the acquisition of an exercise-induced, T(2)-enhanced data set. The data showed the expected fiber organization, from which the physiological cross-sectional area (PCSA), fiber length, and pennation angle for the tibialis anterior (TA) were obtained. The values of these parameters ranged from 5.4-9.1 mm(2), 5.8-7.8 mm, and 21-24 degrees , respectively, which is in agreement with values obtained previously with the use of invasive methods. This study shows that 3D DT acquisition and fiber tracking is feasible for the skeletal muscle of mice, and thus enables the quantitative determination of muscle architecture.

NIST Calibration of a Neutron Spectrometer ROSPEC.

PubMed

Heimbach, Craig

2006-01-01

A neutron spectrometer was acquired for use in the measurement of National Institute of Standards and Technology neutron fields. The spectrometer included options for the measurement of low and high energy neutrons, for a total measurement range from 0.01 eV up to 17 MeV. The spectrometer was evaluated in calibration fields and was used to determine the neutron spectrum of an Americium-Beryllium neutron source. The calibration fields used included bare and moderated (252)Cf, monoenergetic neutron fields of 2.5 MeV and 14 MeV, and a thermal-neutron beam. Using the calibration values determined in this exercise, the spectrometer gives a good approximation of the neutron spectrum, and excellent values for neutron fluence, for all NIST calibration fields. The spectrometer also measured an Americium-Beryllium neutron field in a NIST exposure facility and determined the field quite well. The spectrometer measured scattering effects in neutron spectra which previously could be determined only by calculation or integral measurements.

Critical layer thickness in In/sub 0. 2/Ga/sub 0. 8/As/GaAs single strained quantum well structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fritz, I.J.; Gourley, P.L.; Dawson, L.R.

1987-09-28

We report accurate determination of the critical layer thickness (CLT) for single strained-layer epitaxy in the InGaAs/GaAs system. Our samples were molecular beam epitaxially grown, selectively doped, single quantum well structures comprising a strained In/sub 0.2/Ga/sub 0.8/As layer imbedded in GaAs. We determined the CLT by two sensitive techniques: Hall-effect measurements at 77 K and photoluminescence microscopy. Both techniques indicate a CLT of about 20 nm. This value is close to that determined previously (--15 nm) for comparable strained-layer superlattices, but considerably less than the value of --45 nm suggested by recent x-ray rocking-curve measurements. We show by a simplemore » calculation that photoluminescence microscopy is more than two orders of magnitude more sensitive to dislocations than x-ray diffraction. Our results re-emphasize the necessity of using high-sensitivity techniques for accurate determination of critical layer thicknesses.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuvin, S. A.; Wuosmaa, A. H.; Lister, C. J.

Here, the rate of the T=1, 2+ to T=1, 0 + transition in 10B ( T=1, T z=0) is compared to the analog transitions in 10Be ( T=1, T z=–1) and 10C ( T=1, T z=+1) to provide constraints on ab initio calculations using realistic nuclear forces. The relevant state in 10B, at E x=5.164 MeV, is particle unbound. Therefore, a determination of the B( E2) electromagnetic transition rate requires a precise and accurate determination of the width of the state, as well as the α-particle and γ-ray branching ratios. Previous measurements of the α-particle branching ratio are just barelymore » in agreement. We report on a new study of the α-particle branch by studying the 10B(p,p') 10B* reaction in inverse kinematics with the HELIOS spectrometer. The α-particle branching ratio that we observe, 0.144±0.027, is in good agreement with the evaluated value and improves the associated uncertainty. The resulting experimental B( E2) value is 7.0±2.2 e 2fm 4 and is more consistent with a flat trend across the A=10 triplet than previously reported. This is inconsistent with Green's function Monte Carlo predictions using realistic three-nucleon Hamiltonians, which overpredict the B(E2) value in 10C and 10B.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuvin, S. A.; Wuosmaa, A. H.; Lister, C. J.

The rate of the T = 1, 2(+) to T = 1, 0(+) transition in B-10 (T = 1, T-z = 0) is compared to the analog transitions in Be-10 (T = 1, T-z = -1) and C-10 (T = 1, T-z = +1) to provide constraints on ab initio calculations using realistic nuclear forces. The relevant state in B-10, at E-x = 5.164 MeV, is particle unbound. Therefore, a determination of the B(E2) electromagnetic transition rate requires a precise and accurate determination of the width of the state, as well as the alpha-particle and gamma-ray branching ratios. Previous measurementsmore » of the a-particle branching ratio are just barely in agreement. We report on a new study of the alpha-particle branch by studying the B-10(p, p') B-10* reaction in inverse kinematics with the HELIOS spectrometer. The alpha-particle branching ratio that we observe, 0.144 +/- 0.027, is in good agreement with the evaluated value and improves the associated uncertainty. The resulting experimental B(E2) value is 7.0 +/- 2.2 e(2)fm(4) and is more consistent with a flat trend across the A = 10 triplet than previously reported. This is inconsistent with Green's functionMonte Carlo predictions using realistic three-nucleon Hamiltonians, which overpredict the B(E2) value in C-10 and B-10.« less

Temporal and spatial distributions of precursory seismicity rate changes in the Thailand-Laos-Myanmar border region: implication for upcoming hazardous earthquakes

NASA Astrophysics Data System (ADS)

Puangjaktha, Prayot; Pailoplee, Santi

2018-01-01

To study the prospective areas of upcoming strong-to-major earthquakes, i.e., M w ≥ 6.0, a catalog of seismicity in the vicinity of the Thailand-Laos-Myanmar border region was generated and then investigated statistically. Based on the successful investigations of previous works, the seismicity rate change (Z value) technique was applied in this study. According to the completeness earthquake dataset, eight available case studies of strong-to-major earthquakes were investigated retrospectively. After iterative tests of the characteristic parameters concerning the number of earthquakes ( N) and time window ( T w ), the values of 50 and 1.2 years, respectively, were found to reveal an anomalous high Z-value peak (seismic quiescence) prior to the occurrence of six out of the eight major earthquake events studied. In addition, the location of the Z-value anomalies conformed fairly well to the epicenters of those earthquakes. Based on the investigation of correlation coefficient and the stochastic test of the Z values, the parameters used here ( N = 50 events and T w = 1.2 years) were suitable to determine the precursory Z value and not random phenomena. The Z values of this study and the frequency-magnitude distribution b values of a previous work both highlighted the same prospective areas that might generate an upcoming major earthquake: (i) some areas in the northern part of Laos and (ii) the eastern part of Myanmar.

Adding glycaemic index and glycaemic load functionality to DietPLUS, a Malaysian food composition database and diet intake calculator.

PubMed

Shyam, Sangeetha; Wai, Tony Ng Kock; Arshad, Fatimah

2012-01-01

This paper outlines the methodology to add glycaemic index (GI) and glycaemic load (GL) functionality to food DietPLUS, a Microsoft Excel-based Malaysian food composition database and diet intake calculator. Locally determined GI values and published international GI databases were used as the source of GI values. Previously published methodology for GI value assignment was modified to add GI and GL calculators to the database. Two popular local low GI foods were added to the DietPLUS database, bringing up the total number of foods in the database to 838 foods. Overall, in relation to the 539 major carbohydrate foods in the Malaysian Food Composition Database, 243 (45%) food items had local Malaysian values or were directly matched to International GI database and another 180 (33%) of the foods were linked to closely-related foods in the GI databases used. The mean ± SD dietary GI and GL of the dietary intake of 63 women with previous gestational diabetes mellitus, calculated using DietPLUS version3 were, 62 ± 6 and 142 ± 45, respectively. These values were comparable to those reported from other local studies. DietPLUS version3, a simple Microsoft Excel-based programme aids calculation of diet GI and GL for Malaysian diets based on food records.

The Rydberg constant and proton size from atomic hydrogen

NASA Astrophysics Data System (ADS)

Beyer, Axel; Maisenbacher, Lothar; Matveev, Arthur; Pohl, Randolf; Khabarova, Ksenia; Grinin, Alexey; Lamour, Tobias; Yost, Dylan C.; Hänsch, Theodor W.; Kolachevsky, Nikolai; Udem, Thomas

2017-10-01

At the core of the “proton radius puzzle” is a four-standard deviation discrepancy between the proton root-mean-square charge radii (rp) determined from the regular hydrogen (H) and the muonic hydrogen (µp) atoms. Using a cryogenic beam of H atoms, we measured the 2S-4P transition frequency in H, yielding the values of the Rydberg constant R∞ = 10973731.568076(96) per meterand rp = 0.8335(95) femtometer. Our rp value is 3.3 combined standard deviations smaller than the previous H world data, but in good agreement with the µp value. We motivate an asymmetric fit function, which eliminates line shifts from quantum interference of neighboring atomic resonances.

Ionization chamber correction factors for MR-linacs

NASA Astrophysics Data System (ADS)

Pojtinger, Stefan; Steffen Dohm, Oliver; Kapsch, Ralf-Peter; Thorwarth, Daniela

2018-06-01

Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B. The purpose of this study is to systematically investigate k B for a typical reference setup for commercially available ionization chambers with different magnetic field strengths. The Monte Carlo simulation tool EGSnrc was used to simulate eight commercially available ionization chambers in magnetic fields whose magnetic flux density was in the range of 0–2.5 T. To validate the simulation, the influence of the magnetic field was experimentally determined for a PTW30013 Farmer-type chamber for magnetic flux densities between 0 and 1.425 T. Changes in the detector response of up to 8% depending on the magnetic flux density, on the chamber geometry and on the chamber orientation were obtained. In the experimental setup, a maximum deviation of less than 2% was observed when comparing measured values with simulated values. Dedicated values for two MR-linac systems (ViewRay MRIdian, ViewRay Inc, Cleveland, United States, 0.35 T/ 6 MV and Elekta Unity, Elekta AB, Stockholm, Sweden, 1.5 T/7 MV) were determined for future use in reference dosimetry. Simulated values for thimble-type chambers are in good agreement with experiments as well as with the results of previous publications. After further experimental validation, the results can be considered for definition of standard protocols for purposes of reference dosimetry in MRgRT.

Ionization chamber correction factors for MR-linacs.

PubMed

Pojtinger, Stefan; Dohm, Oliver Steffen; Kapsch, Ralf-Peter; Thorwarth, Daniela

2018-06-07

Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B . The purpose of this study is to systematically investigate k B for a typical reference setup for commercially available ionization chambers with different magnetic field strengths. The Monte Carlo simulation tool EGSnrc was used to simulate eight commercially available ionization chambers in magnetic fields whose magnetic flux density was in the range of 0-2.5 T. To validate the simulation, the influence of the magnetic field was experimentally determined for a PTW30013 Farmer-type chamber for magnetic flux densities between 0 and 1.425 T. Changes in the detector response of up to 8% depending on the magnetic flux density, on the chamber geometry and on the chamber orientation were obtained. In the experimental setup, a maximum deviation of less than 2% was observed when comparing measured values with simulated values. Dedicated values for two MR-linac systems (ViewRay MRIdian, ViewRay Inc, Cleveland, United States, 0.35 T/ 6 MV and Elekta Unity, Elekta AB, Stockholm, Sweden, 1.5 T/7 MV) were determined for future use in reference dosimetry. Simulated values for thimble-type chambers are in good agreement with experiments as well as with the results of previous publications. After further experimental validation, the results can be considered for definition of standard protocols for purposes of reference dosimetry in MRgRT.

High-Precision Half-Life Measurement for the Superallowed β+ Emitter Alm26

NASA Astrophysics Data System (ADS)

Finlay, P.; Ettenauer, S.; Ball, G. C.; Leslie, J. R.; Svensson, C. E.; Andreoiu, C.; Austin, R. A. E.; Bandyopadhyay, D.; Cross, D. S.; Demand, G.; Djongolov, M.; Garrett, P. E.; Green, K. L.; Grinyer, G. F.; Hackman, G.; Leach, K. G.; Pearson, C. J.; Phillips, A. A.; Sumithrarachchi, C. S.; Triambak, S.; Williams, S. J.

2011-01-01

A high-precision half-life measurement for the superallowed β+ emitter Alm26 was performed at the TRIUMF-ISAC radioactive ion beam facility yielding T1/2=6346.54±0.46stat±0.60systms, consistent with, but 2.5 times more precise than, the previous world average. The Alm26 half-life and ft value, 3037.53(61) s, are now the most precisely determined for any superallowed β decay. Combined with recent theoretical corrections for isospin-symmetry-breaking and radiative effects, the corrected Ft value for Alm26, 3073.0(12) s, sets a new benchmark for the high-precision superallowed Fermi β-decay studies used to test the conserved vector current hypothesis and determine the Vud element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.

Development of high temperature calorimeter: heat capacity measurement by direct heating pulse calorimetry

NASA Astrophysics Data System (ADS)

Arita, Yuji; Suzuki, Keisuke; Matsui, Tsuneo

2005-02-01

The temperature limit for heat capacity measurements with the direct heating pulse calorimeter has been increased up to 2000 K by means of the combination of an optical pyrometer to detect the relative temperature change with tungsten rhenium thermocouples to determine absolute temperatures. With this improved calorimeter the heat capacities were measured up to 1950 K, for SiC and B4C, and 2000 K for graphite. The heat capacity values obtained in this study were in good agreement, within the error of ±5%, with those previous values calculated from the enthalpy data by drop method. The electrical conductivities of SiC, B4C and graphite were also simultaneously determined from the inducted voltage and the current for heat capacity measurement.

Energy metabolism of Macaca mulatta during spaceflight

NASA Technical Reports Server (NTRS)

Hoban-Higgins, T. M.; Stein, T. P.; Dotsenko, M. A.; Korolkov, V. I.; Fuller, C. A.

2000-01-01

The mean daily energy expenditure rates of two rhesus monkeys (Macaca mulatta) were determined during spaceflight on the joint U.S./Russian Bion 11 mission by the doubly labeled water (DLW, 2H218O) method. Control values were obtained from two studies performed under flight-like conditions (n = 4). The mean inflight energy expenditure for the two Bion 11 monkeys was 81.3 kcal/kg/day, which was higher than that seen previously. The average energy expenditure (77.6 +/- 4.4 kcal/kg/day) for the four ground control monkeys was slightly lower than had been measured previously.

Quantitative in vivo fluorescence cross-correlation analyses highlight the importance of competitive effects in the regulation of protein-protein interactions.

PubMed

Sadaie, Wakako; Harada, Yoshie; Matsuda, Michiyuki; Aoki, Kazuhiro

2014-09-01

Computer-assisted simulation is a promising approach for clarifying complicated signaling networks. However, this approach is currently limited by a deficiency of kinetic parameters determined in living cells. To overcome this problem, we applied fluorescence cross-correlation spectrometry (FCCS) to measure dissociation constant (Kd) values of signaling molecule complexes in living cells (in vivo Kd). Among the pairs of fluorescent molecules tested, that of monomerized enhanced green fluorescent protein (mEGFP) and HaloTag-tetramethylrhodamine was most suitable for the measurement of in vivo Kd by FCCS. Using this pair, we determined 22 in vivo Kd values of signaling molecule complexes comprising the epidermal growth factor receptor (EGFR)-Ras-extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP) kinase pathway. With these parameters, we developed a kinetic simulation model of the EGFR-Ras-ERK MAP kinase pathway and uncovered a potential role played by stoichiometry in Shc binding to EGFR during the peak activations of Ras, MEK, and ERK. Intriguingly, most of the in vivo Kd values determined in this study were higher than the in vitro Kd values reported previously, suggesting the significance of competitive bindings inside cells. These in vivo Kd values will provide a sound basis for the quantitative understanding of signal transduction. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Color distribution of a shade guide in the value, chroma, and hue scale.

PubMed

Ahn, Jin-Soo; Lee, Yong-Keun

2008-07-01

Shade tabs in a shade guide are matched to teeth in the order of value, hue, and chroma; therefore, information on the distribution of shade tabs is essential for clinical application of a shade guide. However, there is limited information on the color distribution as sorted by these 3 parameters of a recently introduced shade guide. The purposes of this study were to determine the color distributions of tabs from a shade guide in the value (CIE L*), chroma (C*(ab)), and hue scale, and to determine the distribution of step intervals between adjacent tabs by value and chroma. The color of shade tabs (n=29) from a shade guide (Vitapan 3D-Master) was measured to determine the distribution of shade tabs by the value, chroma, hue angle, and CIE a* and b* values. The distribution of the ratios of the value and the chroma of each tab, when compared with the lowest value tab or the lowest chroma tab, was also determined. The data for each color parameter were analyzed by a 3-way ANOVA with the factors of value, chroma, and hue designations of the tabs (alpha=.05). The value, chroma, hue angle, and CIE a* and b* values were influenced by the value, chroma, and hue designations of shade tabs (P<.001). The distributions of the chroma of the tabs within the same value group were relatively ordered, but the values of different value groups overlapped in several instances. Distributions for the CIE a* and b* values reflected the chroma designations in each value group. In the same value group, L, M, and R hue designations corresponded with the manufacturer's stated hue, such as a yellow hue for the L designation and a red hue for the R designation. The distance in the value and chroma scales between adjacent tabs was not uniform. The color distribution of the Vitapan 3D-Master shade guide was more ordered than previously reported color distributions of other, traditional shade guides. However, the interval in the color parameters between adjacent tabs was not uniform; therefore, shade tabs spaced equally, according to the color parameters, should be studied based on the observer's response data.

Temperament, Select Home Environment Characteristics and Reading Readiness as Predictors of Reading Progress.

ERIC Educational Resources Information Center

Brown, T.J.

Progress in a primary-grade reading program was determined for 106 first-born, second-grade students at the end of the school year. Previous data available for this sample included Thomas-Chase-Birch temperament ratings, family intactness and socioeconomic status at age four, and Metropolitan Readiness Test scores at age six. The value of these…

Life Expectancy and Human Capital Investments: Evidence from Maternal Mortality Declines. NBER Working Paper No. 13947

ERIC Educational Resources Information Center

Jayachandran, Seema; Lleras-Muney, Adriana

2008-01-01

Longer life expectancy should encourage human capital accumulation, since a longer time horizon increases the value of investments that pay out over time. Previous work has been unable to determine the empirical importance of this life-expectancy effect due to the difficulty of isolating it from other effects of health on education. We examine a…

Reflection coefficients of permeant molecules in human red cell suspensions.

PubMed

Owen, J D; Eyring, E M

1975-08-01

The Staverman reflection coefficient, sigma for several permeant molecules was determined in human red cell suspensions with a Durrum stopped-flow spectrophotometer. This procedure was first used with dog, cat, and beef red cells and with human red cells. The stopped-flow technique used was similar to the rapid-flow method used by those who originally reported sigma measurements in human red cells for molecules which rapidly penetrate the red cell membrane. The sigma values we obtained agreed with those previously reported for most of the slow penetrants, except malonamide, but disagreed with all the sigma values previously reported for the rapid penetrants. We were unable to calculate an "equivalent pore radius" with our sigma data. The advantages of our equipment and our experimental procedure are discussed. Our sigma data suggest that sigma is indirectly proportional to the log of the nonelectrolyte permeability coefficient, omega. Since a similar trend has been previously shown for log omega and molar volume of the permeant molecules, a correlatioo was shown between sigma and molar volume suggesting the membrane acts as a sieve.

Medicine and the call for a moral epistemology, part II: constructing a synthesis of values.

PubMed

Tauber, Alfred I

2008-01-01

The demands and needs of an individual patient require diverse value judgments to interpret and apply clinical data. Indeed, objective assessment takes on particular meaning in the context of the social and existential status of the patient, and thereby a complex calculus of values determines therapeutic goals. I have previously formulated how this moral thread of care becomes woven into the epistemological project as a "moral epistemology." Having argued its ethical justification elsewhere, I offer another perspective here: clinical choices employ diverse values directed at an array of goals, some of which are derived from a universal clinical science and others from the particular physiological, psychological, and social needs of the patient. Integrating these diverse elements that determine clinical care requires a complex synthesis of facts and judgments from several domains. This constructivist process relies on clinical facts, as well as on personal judgments and subjective assessments in an ongoing negotiation between patient and doctor. A philosophy of medicine must account for the conceptual basis of this process by identifying and addressing the judgments that govern the complex synthesis of these various elements.

Maximal isometric muscle strength values obtained By hand-held dynamometry in children between 6 and 15 years of age.

PubMed

Escobar, Raul G; Munoz, Karin T; Dominguez, Angelica; Banados, Pamela; Bravo, Maria J

2017-01-01

In this study we aimed to determine the maximal isometric muscle strength of a healthy, normal-weight, pediatric population between 6 and 15 years of age using hand-held dynamometry to establish strength reference values. The secondary objective was determining the relationship between strength and anthropometric parameters. Four hundred normal-weight Chilean children, split into 10 age groups, separated by 1-year intervals, were evaluated. Each age group included between 35 and 55 children. The strength values increased with increasing age and weight, with a correlation of 0.83 for age and 0.82 for weight. The results were similar to those reported in previous studies regarding the relationships among strength, age, and anthropometric parameters, but the reported strength differed. These results provide normal strength parameters for healthy and normal-weight Chilean children between 6 and 15 years of age and highlight the relevance of ethnicity in defining reference values for muscle strength in a pediatric population. Muscle Nerve 55: 16-22, 2017. © 2016 Wiley Periodicals, Inc.

Application of New Partition Coefficients to Modeling Plagioclase

NASA Technical Reports Server (NTRS)

Fagan, A. L.; Neal, C. R.; Rapp, J. F.; Draper, D. S.; Lapen, T. J.

2017-01-01

Previously, studies that determined the partition coefficient for an element, i, between plagioclase and the residual basaltic melt (Di plag) have been conducted using experimental conditions dissimilar from the Moon, and thus these values are not ideal for modeling plagioclase fractionation in a lunar system. However, recent work [1] has determined partition coefficients for plagioclase at lunar oxygen fugacities, and resulted in plagioclase with Anorthite contents =An90; these are significantly more calcic than plagioclase in previous studies, and the An content has a profound effect on partition coefficient values [2,3]. Plagioclase D-values, which are dependent on the An content of the crystal [e.g., 2-6], can be determined using published experimental data and the correlative An contents. Here, we examine new experimental data from [1] to ascertain their effect on the calculation of equilibrium liquids from Apollo 16 sample 60635,2. This sample is a coarse grained, subophitic impact melt composed of 55% plagioclase laths with An94.4-98.7 [7,8], distinctly more calcic than of previous partition coefficient studies (e.g., [3-6, 9-10]). Sample 60635,2 is notable as having several plagioclase trace element analyses containing a negative Europium anomaly (-Eu) in the rare-earth element (REE) profile, rather than the typical positive Eu anomaly (+Eu) [7-8] (Fig. 1). The expected +Eu is due to the similarity in size and charge with Ca2+, thereby allowing Eu2+ to be easily taken up by the plagioclase crystal structure, in contrast to the remaining REE3+. Some 60635,2 plagioclase crystals only have +Eu REE profiles, some only have -Eu REE profiles, and some +Eu and -Eu analyses in different areas on a single crystal [7, 8]. Moreover, there does not seem to be any core-rim association with the +Eu or -Eu analyses, nor does there appear to be a correlation between the size, shape, or location of a particular crystal within the sample and the sign of its Eu anomaly, which suggests a complex evolution. In order to investigate this sample further, we can calculate the equilibrium liquids, but with An contents distinct from previous experimental studies, we must calculate the appropriate partition coefficients for each trace element analysis.

Dynamic estimator for determining operating conditions in an internal combustion engine

DOEpatents

Hellstrom, Erik; Stefanopoulou, Anna; Jiang, Li; Larimore, Jacob

2016-01-05

Methods and systems are provided for estimating engine performance information for a combustion cycle of an internal combustion engine. Estimated performance information for a previous combustion cycle is retrieved from memory. The estimated performance information includes an estimated value of at least one engine performance variable. Actuator settings applied to engine actuators are also received. The performance information for the current combustion cycle is then estimated based, at least in part, on the estimated performance information for the previous combustion cycle and the actuator settings applied during the previous combustion cycle. The estimated performance information for the current combustion cycle is then stored to the memory to be used in estimating performance information for a subsequent combustion cycle.

Manning's roughness coefficient for Illinois streams

USGS Publications Warehouse

Soong, David T.; Prater, Crystal D.; Halfar, Teresa M.; Wobig, Loren A.

2012-01-01

Manning's roughness coefficients for 43 natural and constructed streams in Illinois are reported and displayed on a U.S. Geological Survey Web site. At a majority of the sites, discharge and stage were measured, and corresponding Manning's coefficients—the n-values—were determined at more than one river discharge. The n-values discussed in this report are computed from data representing the stream reach studied and, therefore, are reachwise values. Presentation of the resulting n-values takes a visual-comparison approach similar to the previously published Barnes report (1967), in which photographs of channel conditions, description of the site, and the resulting n-values are organized for each site. The Web site where the data can be accessed and are displayed is at URL http://il.water.usgs.gov/proj/nvalues/.

Application of maximum entropy to statistical inference for inversion of data from a single track segment.

PubMed

Stotts, Steven A; Koch, Robert A

2017-08-01

In this paper an approach is presented to estimate the constraint required to apply maximum entropy (ME) for statistical inference with underwater acoustic data from a single track segment. Previous algorithms for estimating the ME constraint require multiple source track segments to determine the constraint. The approach is relevant for addressing model mismatch effects, i.e., inaccuracies in parameter values determined from inversions because the propagation model does not account for all acoustic processes that contribute to the measured data. One effect of model mismatch is that the lowest cost inversion solution may be well outside a relatively well-known parameter value's uncertainty interval (prior), e.g., source speed from track reconstruction or towed source levels. The approach requires, for some particular parameter value, the ME constraint to produce an inferred uncertainty interval that encompasses the prior. Motivating this approach is the hypothesis that the proposed constraint determination procedure would produce a posterior probability density that accounts for the effect of model mismatch on inferred values of other inversion parameters for which the priors might be quite broad. Applications to both measured and simulated data are presented for model mismatch that produces minimum cost solutions either inside or outside some priors.

Glycaemic index and glycaemic load values of commonly consumed foods in the United Arab Emirates.

PubMed

Al Dhaheri, Ayesha S; Henry, C Jeyakumar K; Mohamad, Maysm N; Ohuma, Eric O; Ismail, Leila Cheikh; Al Meqbaali, Fatima T; Jarrar, Amjad H

2017-04-01

Glycaemic index (GI) and glycaemic load (GL) values of some commonly consumed foods in the United Arab Emirates were determined with an aim of adding these values to the existing international table of GI and GL values. In all, eighteen test foods categorised into breads (n 5), entrée dishes (n 3), main dishes (n 5) and sweet dishes (n 5) were tested. For each test food, at least fifteen healthy participants consumed 25 or 50 g available carbohydrate portions of a reference food (glucose), which was tested three times, and a test food after an overnight fast, was tested once, on separate occasions. Capillary blood samples were obtained by finger-prick and blood glucose was measured using clinical chemistry analyser. A fasting blood sample was obtained at baseline and before consumption of test foods. Additional blood samples were obtained at 15, 30, 45, 60, 90 and 120 min after the consumption of each test food. The GI value of each test food was calculated as the percentage of the incremental area under the blood glucose curve (IAUC) for the test food of each participant divided by the average IAUC for the reference food of the same participant. The GI values of tested foods ranged from low (55 or less) to high (70 or more). The GI values of various breads and rice-containing dishes were comparable with previously published values. This study provides GI and GL values of previously untested traditional Emirati foods which could provide a useful guide on dietary recommendations for the Emirati population.

2007 California Aerosol Study: Evaluation of δ15N as a Tracer Of NOx Sources and Chemsitry

NASA Astrophysics Data System (ADS)

Katzman, T. L.

2017-12-01

Although stable isotopes of N are commonly used as a source tracer, how this tracer is applied is a point of contention. The "source" hypothesis argues that the δ15N value of NO3- reflects the δ15N value of NOx source inputs into the environment, and any observed variation is solely the result of differences in source contributions. Conversely, the "chemistry" hypothesis argues that N isotopes are influenced by chemical reactions, atmospheric or biologic processing, and post-depositional effects. Previous studies often apply the source hypothesis, writing off the chemistry hypothesis as "minor," but others have noted the impact chemistry should has on δ15N values. Given the known complications, this work seeks to assess the use of stable isotopes as tracers, specifically, the assumption that the δ15N value is a tracer of source alone without significant influence from chemical reactions. If the "source" hypothesis is correct, source emission data, known source δ15N values, and isotope mass balance should be able to approximate measured δ15NNO3 values and determine the δ15N value associated with wildfire derived NOx, which is currently unknown. Significant deviations from observed values would support the significance of equilibrium and kinetic isotope effects associated with chemical reactions and processing in the atmosphere. Aerosols collected in during 2007, emission data, and isotopic analysis were utilized to determine the utility of δ15N as tracer of NOx sources. San Diego, California is a coastal urban area influenced by sea salt aerosols, anthropogenic combustion emissions, and seasonal wildfires. Wildfires also have a significant influence on local atmospheric chemistry and 2007 was notable for being one of the worst fire seasons in the San Diego region on record. Isotopic analysis of collected NO3- has suggested that source δ15N values are likely not conserved as NOx is oxidized into NO3-. Given known source contributions and known δ15N values of NOx sources, isotope mass balance predicts that a NOx source with highly positive δ15N value must exist for the source hypothesis to be valid. Furthermore, isotopic analysis has also suggested that wildfire emissions may produce a depleted δ15N, disagreeing with previously predicted δ15N values.

Premature chromosome condensation studies in human leukemia. I. Pretreatment characteristics.

PubMed

Hittelman, W N; Broussard, L C; McCredie, K

1979-11-01

The phenomenon of premature chromosome condensation (PCC) was used to compare the bone marrow proliferation characteristics of 163 patients with various forms of leukemia prior to the initiation of new therapy. The proliferative potential index (PPI, or fraction of G1 cells in late G1 phase) and the fraction of cells in S phase was determined and compared to the type of disease and the bone marrow blast infiltrate for each patient. Previously untreated patients with acute leukemia exhibited an average PPI value three times that of normal bone marrow (37.5% for acute myeloblastic leukemia [AML], acute monomyeloblastic leukemia [AMML], or acute promyelocytic leukemia [APML] and 42% for acute lymphocytic leukemia [ALL] or acute undifferentiated leukemia [AUL]). Untreated chronic myelogenous leukemia (CML) patients showed intermediate PPI values (25.2%), whereas CML patients with controlled disease exhibited nearly normal PPI values (14.6%). On the other hand, blastic-phase CML patients exhibited PPI values closer to that observed in patients with acute leukemia (35.4%). Seven patients with chronic lymphocytic leukemia (CLL) exhibited even higher PPI values. No correlations were observed between PPI values, fraction of cells in S phase, and marrow blast infiltrate. For untreated acute disease patients, PPI values were prognostic for response only at low and high PPI values. These results suggest that the PCC-determined proliferative potential is a biologic reflection of the degree of malignancy within the bone marrow.

High frequency acoustic reflections from an air-snow interface

NASA Astrophysics Data System (ADS)

Courville, Z.; Albert, D. G.; Lieb-Lappen, R.; Fegyveresi, J. M.

2016-12-01

High frequency wave propagation methods can be used to determine in situ near surface micro-pore geometry parameters in real Earth materials including snow. To this end, we have been developing a portable ultrasonic transducer rig to make measurements of acoustic reflections from a variety of natural porous media. Fresh natural snow, in particular, is a difficult material to characterize, as any mechanical interaction is likely to damage the fragile pores and grain bonds. Because acoustic waves are sensitive to the porous material properties, they potentially can be used to measure snow properties in a non-destructive manner. Such methods have already been demonstrated on cohesive porous materials including manufactured foams, porous metals, and sintered glass beads. We conducted high frequency, oblique-angle and near vertical reflection measurements on snow samples in a cold room. We then compare the acoustically derived snow physical parameters, including porosity, with values determined from micro-computed tomography (μCT) and with standard (but destructive) laboratory measurements. Preliminary results using a manufactured open cell foam following previous work by Fellah et al., (2003) shows very good agreement between values of porosity determined from the acoustic measurements and the values determined from μCT image analysis and gravimetric determination. Similarly, preliminary results comparing acoustic measurements of natural, dry snow samples prepared in the laboratory show good agreement between acoustically-derived porosity values and porosity values derived through independent means. Fellah, Z.E.A., S. Berger, W. Lauriks, C. Depollier, C. Aristegui, and J.Y. Chapelon, (2003b), Measuring the porosity and tortuosity of porous materials via reflected waves at oblique incidence, J. Acous. Soc. Am., 113, 2424-2433.

Precision measurements of solar energetic particle elemental composition

NASA Technical Reports Server (NTRS)

Breneman, H.; Stone, E. C.

1985-01-01

Using data from the Cosmic Ray Subsystem (CRS) aboard the Voyager 1 and 2 spacecraft, solar energetic particle abundances or upper limits for all elements with 3 = Z = 30 from a combined set of 10 solar flares during the 1977 to 1982 time period were determined. Statistically meaningful abundances have been determined for the first time for several rare elements including P, Cl, K, Ti and Mn, while the precision of the mean abundances for the more abundant elements has been improved by typically a factor of approximately 3 over previously reported values.

Production, purification and molecular weight determination of the haemolysin of Treponema hyodysenteriae.

PubMed

Kent, K A; Lemcke, R M; Lysons, R J

1988-11-01

The production of haemolysin from Treponema hyodysenteriae was increased by an improved culture method and by repeated incubation of spirochaetes suspended in a buffer containing RNA-core. Ion exchange chromatography on DEAE cellulose followed by gel filtration on Sephadex G100 yielded purified haemolysin free from extraneous protein, as judged by silver-stained polyacrylamide gels. The mol. wt of the purified haemolysin, determined by gel filtration was 19,000, a value similar to that of streptolysin S, but much lower than that previously reported.

Mobilities of uranium and mercury ions in helium

NASA Technical Reports Server (NTRS)

Johnsen, R.; Biondi, M. A.

1972-01-01

The mobilities of mass-identified U(+) and Hg (+) ions in helium were determined in a drift tube-mass spectrometer. For uranium ions, a reduced mobility value is obtained at 305 K and a standard gas density of 2.69 x 10 to the 19th power/cu cm. The mobility of mercury ions is in agreement with two previous determinations. The effect of fast ion injection in drift mobility measurements is discussed, and a technique to circumvent these problems is described. The results are compared with existing theories of ion mobilities.

The fine-structure intervals of (N-14)+ by far-infrared laser magnetic resonance

NASA Technical Reports Server (NTRS)

Brown, John M.; Varberg, Thomas D.; Evenson, Kenneth M.; Cooksy, Andrew L.

1994-01-01

The far-infrared laser magnetic resonance spectra associated with both fine-structure transitions in (N-14)+ in its ground P-3 state have been recorded. This is the first laboratory observation of the J = 1 left arrow 0 transition and its frequency has been determined two orders of magnitude more accurately than previously. The remeasurement of the J = 2 left arrow 1 spectrum revealed a small error in the previous laboratory measurements. The fine-structure splittings (free of hyperfine interactions) determined in this work are (delta)E(sub 10) = 1461.13190 (61) GHz, (delta)E(sub 21) = 2459.38006 (37) GHz. Zero-field transition frequencies which include the effects of hyperfine structure have also been calculated. Refined values for the hyperfine constants and the g(sub J) factors have been obtained.

Characterization of Cladosporols from the Marine Algal-Derived Endophytic Fungus Cladosporium cladosporioides EN-399 and Configurational Revision of the Previously Reported Cladosporol Derivatives.

PubMed

Li, Hong-Lei; Li, Xiao-Ming; Mándi, Attila; Antus, Sándor; Li, Xin; Zhang, Peng; Liu, Yang; Kurtán, Tibor; Wang, Bin-Gui

2017-10-06

Four new cladosporol derivatives, cladosporols F-I (1-4), the known cladosporol C (5), and its new epimer, cladosporol J (6), were isolated and identified from the marine algal-derived endophytic fungus Cladosporium cladosporioides EN-399. Their structures were determined by detailed interpretation of NMR and MS data, and the absolute configurations were established on the basis of TDDFT-ECD and OR calculations. The configurational assignment of cladosporols F (1) and G (2) showed that the previously reported absolute configuration of cladosporol A and all the related cladosporols need to be revised from (4'R) to (4'S). Compounds 1-6 showed antibacterial activity against Escherichia coli, Micrococcus luteus, and Vibrio harveyi with MIC values ranging from 4 to 128 μg/mL. Compound 3 showed significant cytotoxicity against A549, Huh7, and LM3 cell lines with IC 50 values of 5.0, 1.0, and 4.1 μM, respectively, and compound 5 showed activity against H446 cell line with IC 50 value of 4.0 μM.

Summary of studies on the blue-green autofluorescence and light transmission of the ocular lens

NASA Astrophysics Data System (ADS)

Van Best, Jaap A.; Kuppens, Esmeralda V.

1996-07-01

This paper reviews previous work done to demonstrate the clinical relevance of the measurement of blue-green autofluorescence and light transmission of the ocular lens. These can be determined quantitatively with fluorophotometry in a few seconds. Autofluorescence and transmission values are determined in healthy volunteers, in patients with insulin-dependent diabetes mellitus, and in patients with untreated glaucoma or untreated ocular hypertension. The lens autofluorescence of healthy volunteers increased linearly and transmission decreased exponentially with age. Each year of diabetes induced an increase of autofluorescence equal to one extra year of age. Untreated glaucoma or ocular hypertension had no significant effect on lens autofluorescence and transmission. Increased autofluorescence and decreased transmission values in comparison with values of a healthy population are proved to be indicative for an increased risk of developing cataract and the clinical usefulness of these measures is demonstrated. Diabetes is a risk factor for developing cataracts while untreated glaucoma or ocular hypertension is not.

Classification of materials using nuclear magnetic resonance dispersion and/or x-ray absorption

DOE Office of Scientific and Technical Information (OSTI.GOV)

Espy, Michelle A.; Matlashov, Andrei N.; Schultz, Larry J.

Methods for determining the identity of a substance are provided. A classification parameter set is defined to allow identification of substances that previously could not be identified or to allow identification of substances with a higher degree of confidence. The classification parameter set may include at least one of relative nuclear susceptibility (RNS) or an x-ray linear attenuation coefficient (LAC). RNS represents the density of hydrogen nuclei present in a substance relative to the density of hydrogen nuclei present in water. The extended classification parameter set may include T.sub.1, T.sub.2, and/or T.sub.1.rho. as well as at least one additional classificationmore » parameter comprising one of RNS or LAC. Values obtained for additional classification parameters as well as values obtained for T.sub.1, T.sub.2, and T.sub.1.rho. can be compared to known classification parameter values to determine whether a particular substance is a known material.« less

An assessment of the skid resistance effect on traffic safety under wet-pavement conditions.

PubMed

Pardillo Mayora, José M; Jurado Piña, Rafael

2009-07-01

Pavement-tire friction provides the grip that is required for maintaining vehicle control and for stopping in emergency situations. Statistically significant negative correlations of skid resistance values and wet-pavement accident rates have been found in previous research. Skid resistance measured with SCRIM and crash data from over 1750km of two-lane rural roads in the Spanish National Road System were analyzed to determine the influence of pavement conditions on safety and to assess the effects of improving pavement friction on safety. Both wet- and dry-pavement crash rates presented a decreasing trend as skid resistance values increased. Thresholds in SCRIM coefficient values associated with significant decreases in wet-pavement crash rates were determined. Pavement friction improvement schemes were found to yield significant reductions in wet-pavement crash rates averaging 68%. The results confirm the importance of maintaining adequate levels of pavement friction to safeguard traffic safety as well as the potential of pavement friction improvement schemes to achieve significant crash reductions.

Carbon isotope ratios of selected volatiles in Citrus sinensis and in orange-flavoured food.

PubMed

Schipilliti, Luisa; Bonaccorsi, Ivana; Cotroneo, Antonella; Dugo, Paola; Mondello, Luigi

2015-11-01

Twenty genuine samples of industrially cold-pressed sweet orange essential oils, were analysed by gas chromatography-combustion-isotope ratio mass spectrometry to determine the values of the carbon isotope ratios (δ(13)C(VPDB)) of selected volatiles and assess the corresponding range of authenticity. Successively, four commercial orange-flavoured products were analysed under identical conditions to evaluate the authenticity of the orange flavour. The samples were extracted by solid-phase microextraction under optimised conditions. The evaluation was performed by using an internal standard procedure to neglect the contribution due to the original environment to the isotopic abundance of (13)C. The composition of the volatile fraction of the essential oils and of the flavoured products was determined by gas chromatography coupled to mass spectrometry with linear retention indices, and by gas chromatography with a flame ionisation detector. The δ(13)C(VPDB) values of seven secondary metabolites determined here were successfully used to characterise genuine orange essential oil. These values were used to evaluate the quality of orange-flavoured products, revealing the presence of compounds of different origin, not compatible with the values of genuine orange secondary metabolites. This study provides the range of authenticity of δ(13)C(VPDB) of seven different secondary metabolites in sweet orange genuine essential oil, useful for evaluating the genuineness of orange flavour. In accord with a previous study on different essential oils, the values determined here can be successfully applied for the evaluation of a large number of flavoured food stuffs and correlated with their origins. © 2014 Society of Chemical Industry.

Determination of free sulphydryl groups in wheat gluten under the influence of different time and temperature of incubation: method validation.

PubMed

Rakita, Slađana; Pojić, Milica; Tomić, Jelena; Torbica, Aleksandra

2014-05-01

The aim of the present study was to determine the characteristics of an analytical method for determination of free sulphydryl (SH) groups of wheat gluten performed with previous gluten incubation for variable times (45, 90 and 135min) at variable temperatures (30 and 37°C), in order to determine its fitness-for-purpose. It was observed that the increase in temperature and gluten incubation time caused the increase in the amount of free SH groups, with more dynamic changes at 37°C. The method characteristics identified as relevant were: linearity, limit of detection, limit of quantification, precision (repeatability and reproducibility) and measurement uncertainty, which were checked within the validation protocol, while the method performance was monitored by X- and R-control charts. Identified method characteristics demonstrated its acceptable fitness-for-purpose, when assay included previous gluten incubation at 30°C. Although the method repeatability at 37°C was acceptable, the corresponding reproducibility did not meet the performance criterion on the basis of HORRAT value (HORRAT<2). Copyright © 2013 Elsevier Ltd. All rights reserved.

Hyperfine structure measurements of neutral vanadium by laser-induced fluorescence spectroscopy in the wavelength range from 750 nm to 860 nm

NASA Astrophysics Data System (ADS)

Başar, Gü.; Güzelçimen, F.; Öztürk, I. K.; Er, A.; Bingöl, D.; Kröger, S.; Başar, Gö.

2017-11-01

The hyperfine structure of 57 spectral lines of neutral vanadium has been investigated using a hollow cathode lamp by laser-induced fluorescence spectroscopy in the wavelength range from 750 nm to 860 nm. New magnetic dipole hyperfine structure constants A have been determined for 14 atomic energy levels and new electric quadrupole hyperfine structure constants B for two levels. Additionally previously published hyperfine structure constants A of 56 levels have been measured again. In five cases, the old A values have been rejected and replaced by improved values.

24Na at Ex=4.7 -5.9 MeV from 22Ne(3He,p )

NASA Astrophysics Data System (ADS)

Fortune, H. T.

2018-04-01

Abstract. Analysis of data from the 22Ne(3He,p ) 24Na reaction has been extended to include 18 angular distributions for states between 4.7 and 5.9 MeV. A distorted-wave Born-approximation analysis allows the determination of ℓ value(s) for most of them. Results for Jπ are compared with previous information. In general, agreement is good. Some apparent disagreements between current and past results are indicative of population of a different state in this reaction than the nearby one listed in the compilation.

Heat flow and near-surface radioactivity in the Australian continental crust

USGS Publications Warehouse

Sass, J.H.; Jaeger, J.C.; Munroe, Robert J.

1976-01-01

Heat-flow data have been obtained at 44 sites in various parts of Australia. These include seven sites from the old (~ 2500 m.y.) Precambrian shield of Western Australia, seventeen from the younger (~ 600- 2000 m.y.) Precambrian rocks of South Australia, the Northern Territory, and Queensland, and twenty within the eastern Paleozoic and younger rocks. Thirty of the sites are located where no previous heat-flow data existed, and the remainder provide significant extensions or refinements of areas previously studied. Where the holes studied penetrated the crystalline basement rocks, or where the latter rocks were exposed within a few kilometers of the holes, the upper crustal radiogenic heat production has been estimated based on gamma-ray spectrometric determinations of U, Th, and K abundances. Three heat-flow provinces are recognized in Australia based on the linear relation (q = q* + DA0 ) between heat flow q and surface radioactivity A0. New data from the Western Australian shield support earlier studies showing that heat flow is low to normal with values ranging from 0.7 to 1.2 hfu and with the majority of values less than 1.0 hfu, and the parameters q* = 0.63 hfu and 0 = 4.5 km determined previously were confirmed. Heat flow in the Proterozoic shield of central Australia is quite variable, with values ranging between about l and 3 hfu. This variability is attributed mainly to variations in near-surface crustal radioactivity. The parameters of the heat-flow line are q* = 0.64 hfu and 0 = 11.1 km and moderately high temperatures are predicted for the lower crust and upper mantle. Previous suggestions of a band of l ow- to - normal heat flow near the coast in eastern Australia were confirmed in some areas, but the zone is interrupted in at least one region (the Sydney Basin), where heat flow is about 2.0 hfu over a large area. The reduced heat flow, q*, in the Paleozoic intrusive rocks of eastern Australia varies from about 0.8 to 2.0 hfu . This variability might be related to thermal transients associated with Late Tertiary and younger volcanic and tectonic activity, even though the relation between heat-flow values and the age of volcanism is not a simple one. Parts of the high heat-flow area in the southeast might be exploitable for geothermal energy.

Accurate oscillator strengths for interstellar ultraviolet lines of Cl I

NASA Technical Reports Server (NTRS)

Schectman, R. M.; Federman, S. R.; Beideck, D. J.; Ellis, D. J.

1993-01-01

Analyses on the abundance of interstellar chlorine rely on accurate oscillator strengths for ultraviolet transitions. Beam-foil spectroscopy was used to obtain f-values for the astrophysically important lines of Cl I at 1088, 1097, and 1347 A. In addition, the line at 1363 A was studied. Our f-values for 1088, 1097 A represent the first laboratory measurements for these lines; the values are f(1088)=0.081 +/- 0.007 (1 sigma) and f(1097) = 0.0088 +/- 0.0013 (1 sigma). These results resolve the issue regarding the relative strengths for 1088, 1097 A in favor of those suggested by astronomical measurements. For the other lines, our results of f(1347) = 0.153 +/- 0.011 (1 sigma) and f(1363) = 0.055 +/- 0.004 (1 sigma) are the most precisely measured values available. The f-values are somewhat greater than previous experimental and theoretical determinations.

The Adaptive Response to Intestinal Oxidative Stress in Mammalian Hibernation

DTIC Science & Technology

2003-10-24

redox status and pro- and anti- oxidant enzymes . a) Determination of oxidized lipids in intestinal mucosa: The tissue samples for these studies...hibernation season or between hibernating and summer squirrels. However, a strong trend was observed for lowest values of both enzyme activities in...depression involves moderate release of ROS that are detoxified by GSH-related enzymes . Although seemingly paradoxical, we have previously observed

Lateral control required for satisfactory flying qualities based on flight tests of numerous airplanes

NASA Technical Reports Server (NTRS)

Gilruth, R R; Turner, W N

1941-01-01

Report presents the results of an analysis made of the aileron control characteristics of numerous airplanes tested in flight by the National Advisory Committee for Aeronautics. By the use of previously developed theory, the observed values of pb/2v for the various wing-aileron arrangements were examined to determine the effective section characteristics of the various aileron types.

SU-F-BRA-10: Fricke Dosimetry: Determination of the G-Value for Ir-192 Energy Based On the NRC Methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salata, C; David, M; Rosado, P

Purpose: Use the methodology developed by the National Research Council Canada (NRC), for Fricke Dosimetry, to determine the G-value used at Ir-192 energies. Methods: In this study the Radiology Science Laboratory of Rio de Janeiro State University (LCR),based the G-value determination on the NRC method, using polyethylene bags. Briefly, this method consists of interpolating the G-values calculated for Co-60 and 250 kV x-rays for the average energy of Ir-192 (380 keV). As the Co-60 G-value is well described at literature, and associated with low uncertainties, it wasn’t measured in this present study. The G-values for 150 kV (Effective energy ofmore » 68 keV), 250 kV (Effective energy of 132 keV)and 300 kV(Effective energy of 159 keV)were calculated using the air kerma given by a calibrated ion chamber, and making it equivalent to the absorbed to the Fricke solution, using a Monte Carlo calculated factor for this conversion. Instead of interpolations, as described by the NRC, we displayed the G-values points in a graph, and used the line equation to determine the G- value for Ir-192 (380 keV). Results: The measured G-values were 1.436 ± 0.002 µmol/J for 150 kV, 1.472 ± 0.002 µmol/J for 250 kV, 1.497 ± 0.003 µmol/J for 300 kV. The used G-value for Co-60 (1.25 MeV) was 1,613 µmol/J. The R-square of the fitted regression line among those G-value points was 0.991. Using the line equation, the calculate G-value for 380 KeV was 1.542 µmol/J. Conclusion: The Result found for Ir-192 G-value is 3,1% different (lower) from the NRC value. But it agrees with previous literature results, using different methodologies to calculate this parameter. We will continue this experiment measuring the G-value for Co-60 in order to compare with the NRC method and better understand the reasons for the found differences.« less

α decay of the T = 1 ,   2 + state in B 10 and isospin symmetry breaking in the A = 10 triplet

DOE PAGES

Kuvin, S. A.; Wuosmaa, A. H.; Lister, C. J.; ...

2017-10-03

Here, the rate of the T=1, 2+ to T=1, 0 + transition in 10B ( T=1, T z=0) is compared to the analog transitions in 10Be ( T=1, T z=–1) and 10C ( T=1, T z=+1) to provide constraints on ab initio calculations using realistic nuclear forces. The relevant state in 10B, at E x=5.164 MeV, is particle unbound. Therefore, a determination of the B( E2) electromagnetic transition rate requires a precise and accurate determination of the width of the state, as well as the α-particle and γ-ray branching ratios. Previous measurements of the α-particle branching ratio are just barelymore » in agreement. We report on a new study of the α-particle branch by studying the 10B(p,p') 10B* reaction in inverse kinematics with the HELIOS spectrometer. The α-particle branching ratio that we observe, 0.144±0.027, is in good agreement with the evaluated value and improves the associated uncertainty. The resulting experimental B( E2) value is 7.0±2.2 e 2fm 4 and is more consistent with a flat trend across the A=10 triplet than previously reported. This is inconsistent with Green's function Monte Carlo predictions using realistic three-nucleon Hamiltonians, which overpredict the B(E2) value in 10C and 10B.« less

Determination of the Characteristic Values and Variation Ratio for Sensitive Soils

NASA Astrophysics Data System (ADS)

Milutinovici, Emilia; Mihailescu, Daniel

2017-12-01

In 2008, Romania adopted Eurocode 7, part II, regarding the geotechnical investigations - called SR EN1997-2/2008. However a previous standard already existed in Romania, by using the mathematical statistics in determination of the calculation values, the requirements of Eurocode can be taken into consideration. The setting of characteristics and calculations values of the geotechnical parameters was finally issued in Romania at the end of 2010 at standard NP122-2010 - “Norm regarding determination of the characteristic and calculation values of the geotechnical parameters”. This standard allows using of data already known from analysed area and setting the calculation values of geotechnical parameters. However, this possibility exist, it is not performed easy in Romania, considering that there isn’t any centralized system of information coming from the geotechnical studies performed for various objectives of private or national interests. Every company performing geotechnical studies tries to organize its own data base, but unfortunately none of them use existing centralized data. When determining the values of calculation, an important role is played by the variation ratio of the characteristic values of a geotechnical parameter. There are recommendations in the mentioned Norm, that could be taken into account, regarding the limits of the variation ratio, but these values are mentioned for Quaternary age soils only, normally consolidated, with a content of organic material < 5%. All of the difficult soils are excluded from the Norm even if they exist and affect the construction foundations on more than a half of the Romania’s surface. A type of difficult soil, extremely widespread on the Romania’s territory, is the contractile soil (with high swelling and contractions, very sensitive to the seasonal moisture variations). This type of material covers and influences the construction foundations in one over third of Romania’s territory. This work is proposing to be a step in determination of limits of the variation ratios for the contractile soils category, for the most used geotechnical parameters in the Romanian engineering practice, namely: the index of consistency and the cohesion.

Extending unified-theory-of-reinforcement neural networks to steady-state operant behavior.

PubMed

Calvin, Olivia L; McDowell, J J

2016-06-01

The unified theory of reinforcement has been used to develop models of behavior over the last 20 years (Donahoe et al., 1993). Previous research has focused on the theory's concordance with the respondent behavior of humans and animals. In this experiment, neural networks were developed from the theory to extend the unified theory of reinforcement to operant behavior on single-alternative variable-interval schedules. This area of operant research was selected because previously developed neural networks could be applied to it without significant alteration. Previous research with humans and animals indicates that the pattern of their steady-state behavior is hyperbolic when plotted against the obtained rate of reinforcement (Herrnstein, 1970). A genetic algorithm was used in the first part of the experiment to determine parameter values for the neural networks, because values that were used in previous research did not result in a hyperbolic pattern of behavior. After finding these parameters, hyperbolic and other similar functions were fitted to the behavior produced by the neural networks. The form of the neural network's behavior was best described by an exponentiated hyperbola (McDowell, 1986; McLean and White, 1983; Wearden, 1981), which was derived from the generalized matching law (Baum, 1974). In post-hoc analyses the addition of a baseline rate of behavior significantly improved the fit of the exponentiated hyperbola and removed systematic residuals. The form of this function was consistent with human and animal behavior, but the estimated parameter values were not. Copyright © 2016 Elsevier B.V. All rights reserved.

Combustion of coal gas fuels in a staged combustor

NASA Technical Reports Server (NTRS)

Rosfjord, T. J.; Mcvey, J. B.; Sederquist, R. A.; Schultz, D. F.

1982-01-01

Gaseous fuels produced from coal resources generally have heating values much lower than natural gas; the low heating value could result in unstable or inefficient combustion. Coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable nitrogen oxide exhaust emission levels. Previous investigations indicate that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low nitrogen oxide emission operation for coal-derived liquid fuels contaning up to 0.8-wt pct nitrogen. An experimental program was conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7 pct ammonia are presented.

Carbon and nitrogen abundances in metal-poor dwarfs of the solar neighborhood

NASA Technical Reports Server (NTRS)

Carbon, Duane F.; Barbuy, Beatrice; Kraft, Robert P.; Friel, Eileen D.; Suntzeff, Nicholas B.

1987-01-01

Intermediate-resolution C, N, and Fe abundance spectra for 83 subdwarfs in the lowest metallicity range (-1.5 to -3.2), obtained with the Lick Observatory 3.1-m Shane telescope, are analyzed. The effects of subgiants and binaries on the sample are examined. The relation between (B-V) and (V-K) and effective temperature is studied. C/Fe, N/Fe, and Fe/H abundances were determined using the model-atmosphere technique of spectrum synthesis. The derived abundance values are compared with data from previous investigations. It is observed that there is good correlation between the Fe/H abundance values derived from the intermediate-resolution spectra and those based on high-resolution spectra; C/Fe abundance values are constant; and there is an upturn in the C/Fe abundance values at the very lowest metallicities.

Thermal inactivation of ileal loop-reactive Clostridium perfringens type A strains in phosphate buffer and beef gravy.

PubMed

Bradshaw, J G; Peeler, J T; Twedt, R M

1977-09-01

The thermal resistance of spore crops produced from each of two ileal loop-reactive strains of Clostridium perfringens type A was determined in two suspending vehicles consisting of 0.067 M (pH 7.0) phosphate buffer and a commercial beef gravy. D115.6 values obtained in buffer and enumerated after pretreatment with sodium ethylenediaminetetraacetate and recovery in plating medium containing lysozyme were two- to threefold greater than those obtained without this treatment. D115.6 values obtained with beef gravy were less than those obtained in buffer with or without lysozyme; however, the D98.9 and D104.4 values were 1.3 to 2 times greater than those obtained in buffer with lysozyme. The z values were within the ranges reported by previous investigators.

Thermal inactivation of ileal loop-reactive Clostridium perfringens type A strains in phosphate buffer and beef gravy.

PubMed Central

Bradshaw, J G; Peeler, J T; Twedt, R M

1977-01-01

The thermal resistance of spore crops produced from each of two ileal loop-reactive strains of Clostridium perfringens type A was determined in two suspending vehicles consisting of 0.067 M (pH 7.0) phosphate buffer and a commercial beef gravy. D115.6 values obtained in buffer and enumerated after pretreatment with sodium ethylenediaminetetraacetate and recovery in plating medium containing lysozyme were two- to threefold greater than those obtained without this treatment. D115.6 values obtained with beef gravy were less than those obtained in buffer with or without lysozyme; however, the D98.9 and D104.4 values were 1.3 to 2 times greater than those obtained in buffer with lysozyme. The z values were within the ranges reported by previous investigators. PMID:199113

Decrease in the orbital period of Hercules X-1

NASA Technical Reports Server (NTRS)

Deeter, John E.; Boynton, Paul E.; Miyamoto, Sigenori; Kitamoto, Shunji; Nagase, Fumiaki; Kawai, Nobuyuki

1991-01-01

From a pulse-timing analysis of Ginga observations of the binary X-ray pulsar Her X-1 obtained during the interval 1989 April-June local orbital parameters are determined for a short high state. An orbital epoch is also determined in the adjacent main high state. By comparing these orbital solutions with previously published results, a decrease is detected in the orbital period for Her X-1 over the interval 1971-1989. The value is substantially larger than the value predicted from current estimates of the mass-transfer rate, and motivates consideration of other mechanisms of mass transfer and/or mass loss. A second result from these observations is a close agreement between orbital parameters determined separately in main high and short high states. This agreement places strong constraints on the obliquity of the stellar companion, HZ Her, if undergoing forced precession with a 35-day period. As a consequence further doubt is placed on the slaved-disk model as the underlying cause of the 35-day cycle in Her X-1.

Clinical and Genetic Determinants of Warfarin Pharmacokinetics and Pharmacodynamics during Treatment Initiation

PubMed Central

Gong, Inna Y.; Schwarz, Ute I.; Crown, Natalie; Dresser, George K.; Lazo-Langner, Alejandro; Zou, GuangYong; Roden, Dan M.; Stein, C. Michael; Rodger, Marc; Wells, Philip S.; Kim, Richard B.; Tirona, Rommel G.

2011-01-01

Variable warfarin response during treatment initiation poses a significant challenge to providing optimal anticoagulation therapy. We investigated the determinants of initial warfarin response in a cohort of 167 patients. During the first nine days of treatment with pharmacogenetics-guided dosing, S-warfarin plasma levels and international normalized ratio were obtained to serve as inputs to a pharmacokinetic-pharmacodynamic (PK-PD) model. Individual PK (S-warfarin clearance) and PD (Imax) parameter values were estimated. Regression analysis demonstrated that CYP2C9 genotype, kidney function, and gender were independent determinants of S-warfarin clearance. The values for Imax were dependent on VKORC1 and CYP4F2 genotypes, vitamin K status (as measured by plasma concentrations of proteins induced by vitamin K absence, PIVKA-II) and weight. Importantly, indication for warfarin was a major independent determinant of Imax during initiation, where PD sensitivity was greater in atrial fibrillation than venous thromboembolism. To demonstrate the utility of the global PK-PD model, we compared the predicted initial anticoagulation responses with previously established warfarin dosing algorithms. These insights and modeling approaches have application to personalized warfarin therapy. PMID:22114699

EFFECTS OF TRAMADOL ON THE MINIMUM ANESTHETIC CONCENTRATION OF ISOFLURANE IN WHITE-EYED PARAKEETS (PSITTACARA LEUCOPHTHALMUS).

PubMed

Escobar, André; da Rocha, Rozana Wendler; Midon, Monica; de Almeida, Ricardo Miyasaka; Filho, Darcio Zangirolami; Werther, Karin

2017-06-01

The aim of this study was to determine the minimum anesthetic concentration (MAC) of isoflurane, and to investigate if tramadol changes the isoflurane MAC in white-eyed parakeets (Psittacara leucophthalmus). Ten adult birds weighing 157 ± 9 g were anesthetized with isoflurane in oxygen under mechanical ventilation. Isoflurane concentration for the first bird was adjusted to 2.2%, and after 15 min an electrical stimulus was applied in the thigh area to observe the response (movement or nonmovement). Isoflurane concentration for the subsequent bird was increased by 10% if the previous bird moved, or decreased by 10% if the previous bird did not move. This procedure was performed serially until at least four sequential crossover events were detected. A crossover event was defined as a sequence of two birds with different responses (positive or negative) to the electrical stimulus. Isoflurane MAC was calculated as the mean isoflurane concentration value at the crossover events. After 1 wk, the same birds were reanesthetized with isoflurane and MAC was determined at 15 and 30 min after intramuscular administration of 10 mg/kg of tramadol using the same method. A paired t-test (P < 0.05%) was used to detect significant differences for MAC between treatments. Isoflurane MAC in this population of white-eyed parakeets was 2.47 ± 0.09%. Isoflurane MAC values 15 and 30 min after tramadol administration were indistinguishable from each other (pooled value was 2.50 ± 0.18%); they were also indistinguishable from isoflurane MAC without tramadol. The isoflurane MAC value in white-eyed parakeets is higher than reported for other bird species. Tramadol (10 mg/kg, i.m.) does not change isoflurane MAC in these birds.

a Theoretical Analysis of Physical Properties of Aqueous Trehalose with Borax

NASA Astrophysics Data System (ADS)

Sahara; Aniya, Masaru

2013-07-01

The temperature and composition dependence of the viscosity of aqueous trehalose and aqueous trehalose-borax mixtures has been investigated by means of the Bond Strength-Coordination Number Fluctuation (BSCNF) model. The result indicates that the variation in the fragility of the system is very small in the composition range analyzed. The values of the materials parameters determined are consistent with those of the trehalose-water-lithium iodide system which were analyzed in a previous study. Based on the analysis of the obtained parameters of the BSCNF model, the physical interpretation of the WLF parameters reported in a previous study is reconfirmed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Monaghan, P; Shneor, R; Subedi, R

The five-fold differential cross section for the 12C(e,e'p)11B reaction was determined over a missing momentum range of 200-400 MeV/c, in a kinematics regime with Bjorken x > 1 and Q2 = 2.0 (GeV/c)2. A comparison of the results and theoretical models and previous lower missing momentum data is shown. The theoretical calculations agree well with the data up to a missing momentum value of 325 MeV/c and then diverge for larger missing momenta. The extracted distorted momentum distribution is shown to be consistent with previous data and extends the range of available data up to 400 MeV/c.

Use of stable carbon isotope ratios to determine the source of cypermethrin in so-called natural plant extract formulations used for organic farming.

PubMed

Kawashima, Hiroto; Kariya, Takuro

2017-03-01

Some natural plant extract formulations (NPEFs, also referred to as essential oils) used in organic farming have been shown to contain synthetic pesticides. We obtained samples of four NPEFs (Muso, Hekiro, Kensogen-Ten, and Nurse Green) that were contaminated with the synthetic pyrethroid cypermethrin, and we used gas chromatography coupled with combustion, cryofocusing, and isotope ratio mass spectrometry to determine the stable carbon isotope ratios (δ 13 C) for the cypermethrin in the four NPEF samples, as well as in ten cypermethrin reagents and two commercial pesticide formulations (Agrothrin emulsion and Agrothrin water-dispersible powder). Our goal was to identify the source of the cypermethrin in the NPEFs. Cryofocusing markedly sharpened the cypermethrin peak and thus improved the accuracy and precision of the determined δ 13 C values. The δ 13 C values (± SD) of the 16 cypermethrin samples ranged from -28.3 ± 0.2 to -24.5 ± 0.2 ‰. Surprisingly, the four NPEFs showed similar δ 13 C values (-26.8 to -27.3 ‰), suggesting that the cypermethrin in all the samples came from the same source (either the same chemical reaction or the same primary material). This possibility was supported by previously published results. In addition, the δ 13 C values of the two commercial pesticides were similar to the values for the NPEFs, suggesting that the commercial pesticides had been diluted and sold as NPEFs.

Total Acid Value Titration of Hydrotreated Biomass Fast Pyrolysis Oil: Determination of Carboxylic Acids and Phenolics with Multiple End-Point Detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christensen, E.; Alleman, T. L.; McCormick, R. L.

Total acid value titration has long been used to estimate corrosive potential of petroleum crude oil and fuel oil products. The method commonly used for this measurement, ASTM D664, utilizes KOH in isopropanol as the titrant with potentiometric end point determination by pH sensing electrode and Ag/AgCl reference electrode with LiCl electrolyte. A natural application of the D664 method is titration of pyrolysis-derived bio-oil, which is a candidate for refinery upgrading to produce drop in fuels. Determining the total acid value of pyrolysis derived bio-oil has proven challenging and not necessarily amenable to the methodology employed for petroleum products duemore » to the different nature of acids present. We presented an acid value titration for bio-oil products in our previous publication which also utilizes potentiometry using tetrabutylammonium hydroxide in place of KOH as the titrant and tetraethylammonium bromide in place of LiCl as the reference electrolyte to improve the detection of these types of acids. This method was shown to detect numerous end points in samples of bio-oil that were not detected by D664. These end points were attributed to carboxylic acids and phenolics based on the results of HPLC and GC-MS studies. Additional work has led to refinement of the method and it has been established that both carboxylic acids and phenolics can be determined accurately. Use of pH buffer calibration to determine half-neutralization potentials of acids in conjunction with the analysis of model compounds has allowed us to conclude that this titration method is suitable for the determination of total acid value of pyrolysis oil and can be used to differentiate and quantify weak acid species. The measurement of phenolics in bio-oil is subject to a relatively high limit of detection, which may limit the utility of titrimetric methodology for characterizing the acidic potential of pyrolysis oil and products.« less

IMPROVED Ti II log(gf) VALUES AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, M. P.; Lawler, J. E.; Sneden, C.

2013-10-01

Atomic transition probability measurements for 364 lines of Ti II in the UV through near-IR are reported. Branching fractions from data recorded using a Fourier transform spectrometer (FTS) and a new echelle spectrometer are combined with published radiative lifetimes to determine these transition probabilities. The new results are in generally good agreement with previously reported FTS measurements. Use of the new echelle spectrometer, independent radiometric calibration methods, and independent data analysis routines enables a reduction of systematic errors and overall improvement in transition probability accuracy over previous measurements. The new Ti II data are applied to high-resolution visible and UVmore » spectra of the Sun and metal-poor star HD 84937 to derive new, more accurate Ti abundances. Lines covering a range of wavelength and excitation potential are used to search for non-LTE effects. The Ti abundances derived using Ti II for these two stars match those derived using Ti I and support the relative Ti/Fe abundance ratio versus metallicity seen in previous studies.« less

Translational MRI volumetry with NeuroQuant: Effects of version and normative data on relationships with memory performance in healthy older adults and patients with mild cognitive impairment

PubMed Central

Stelmokas, Julija; Yassay, Lance; Giordani, Bruno; Dodge, Hiroko H.; Dinov, Ivo D.; Bhaumik, Arijit; Sathian, K.; Hampstead, Benjamin M.

2018-01-01

NeuroQuant (NQ) is a fully-automated program that overcomes several existing limitations in the clinical translation of MRI-derived volumetry. The current study characterized differences between the original (NQ1) and an updated NQ version (NQ2) by (i) replicating previously identified relationships between neuropsychological test performance and medial temporal lobe volumes, (ii) evaluating the level of agreement between NQ versions, and (iii) determining if the addition of NQ2 age-/sex-based z-scores hold greater clinical utility for prediction of memory impairment than standard percent of intracranial volume (%ICV) values. Sixty-seven healthy older adults and 65 MCI patients underwent structural MRI and completed cognitive testing, including the Immediate and Delayed Memory indices from the RBANS. Results generally replicated previous relationships between key medial temporal lobe regions and memory test performance, though comparison of NQ regions revealed statistically different values that were biased toward one version or the other depending on the region. NQ2 hippocampal z-scores explained additional variance in memory performance relative to %ICV values. Findings indicate that NQ1/2 medial temporal lobe volumes, especially age- and sex-based z-scores, hold clinical value, though caution is warranted when directly comparing volumes across NQ versions. PMID:29060939

Fatigue of die cast zinc alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schrems, K.K.; Dogan, O.N.; Goodwin, F.E.

2006-04-01

The rotating bending fatigue limit of die cast zinc alloy 2, alloy 3, alloy 5, AcuZinc 5, and ZA-8 were determined as a part of an on-going program by ILZRO into the mechanical properties of die cast zinc. The stress-life (S-N) curves of alloys 3, 5, AcuZinc 5, and ZA-8 were determined previously. This presentation reports the results of the S-N curve for Alloy 2 and the calculated fatigue limits for all five alloys. During the previous stress-life testing, the samples were stopped at 10 million cycles and the fatigue limit for alloy 3, alloy 5, and AcuZinc 5 appearedmore » to be higher and the fatigue limit for ZA-8 appeared to be lower than the values reported in the literature. This was further investigated in alloy 5 and ZA-8 by testing continuous cast bulk alloy 5 and ZA-8.« less

Polarographic determination of lead hydroxide formation constants at low ionic strength

USGS Publications Warehouse

Lind, Carol J.

1978-01-01

Values of formation constants for lead hydroxide at 25 ??C were calculated from normal pulse polarographic measurements of 10-6 M lead in 0.01 M sodium perchlorate. The low concentrations simulate those found in many freshwaters, permitting direct application of the values when considering distributions of lead species. The precise evaluation of species distribution in waters at other ionic strengths requires activity coefficient corrections. As opposed to much of the previously published work done at high ionic strength, the values reported here were obtained at low ionic strength, permitting use of smaller and better defined activity coefficient corrections. These values were further confirmed by differential-pulse polarography and differential-pulse anodic stripping voltammetry data. The logs of the values for ??1??? ??2???, and ??3??? were calculated to be 6.59, 10.80, and 13.63, respectively. When corrected to zero ionic strength these values were calculated to be 6.77, 11.07, and 13.89, respectively.

Momentum and energy dependent resolution function of the ARCS neutron chopper spectrometer at high momentum transfer: Comparing simulation and experiment

NASA Astrophysics Data System (ADS)

Diallo, S. O.; Lin, J. Y. Y.; Abernathy, D. L.; Azuah, R. T.

2016-11-01

Inelastic neutron scattering at high momentum transfers (i.e. Q ≥ 20 A ˚), commonly known as deep inelastic neutron scattering (DINS), provides direct observation of the momentum distribution of light atoms, making it a powerful probe for studying single-particle motions in liquids and solids. The quantitative analysis of DINS data requires an accurate knowledge of the instrument resolution function Ri(Q , E) at each momentum Q and energy transfer E, where the label i indicates whether the resolution was experimentally observed i = obs or simulated i=sim. Here, we describe two independent methods for determining the total resolution function Ri(Q , E) of the ARCS neutron instrument at the Spallation Neutron Source, Oak Ridge National Laboratory. The first method uses experimental data from an archetypical system (liquid 4He) studied with DINS, which are then numerically deconvoluted using its previously determined intrinsic scattering function to yield Robs(Q , E). The second approach uses accurate Monte Carlo simulations of the ARCS spectrometer, which account for all instrument contributions, coupled to a representative scattering kernel to reproduce the experimentally observed response S(Q , E). Using a delta function as scattering kernel, the simulation yields a resolution function Rsim(Q , E) with comparable lineshape and features as Robs(Q , E), but somewhat narrower due to the ideal nature of the model. Using each of these two Ri(Q , E) separately, we extract characteristic parameters of liquid 4He such as the intrinsic linewidth α2 (which sets the atomic kinetic energy 〈 K 〉 ∼α2) in the normal liquid and the Bose-Einstein condensate parameter n0 in the superfluid phase. The extracted α2 values agree well with previous measurements at saturated vapor pressure (SVP) as well as at elevated pressure (24 bars) within experimental precision, independent of which Ri(Q , y) is used to analyze the data. The actual observed n0 values at each Q vary little with the model Ri(Q , E), and the effective Q-averaged n0 values are consistent with each other, and with previously reported values.

Temperature-dependent rate coefficients for the reactions of the hydroxyl radical with the atmospheric biogenics isoprene, alpha-pinene and delta-3-carene

NASA Astrophysics Data System (ADS)

Dillon, Terry J.; Dulitz, Katrin; Groß, Christoph B. M.; Crowley, John N.

2017-12-01

Pulsed laser methods for OH generation and detection were used to study atmospheric degradation reactions for three important biogenic gases: OH + isoprene (Reaction R1), OH +α-pinene (Reaction R2) and OH + Δ-3-carene (Reaction R3). Gas-phase rate coefficients were characterized by non-Arrhenius kinetics for all three reactions. For (R1), k1 (241-356 K) = (1.93±0.08) × 10-11exp{(466±12)/T} cm3 molecule-1 s-1 was determined, with a room temperature value of k1 (297 K) = (9.3±0.4) × 10-11 cm3 molecule-1 s-1, independent of bath-gas pressure (5-200 Torr) and composition (M = N2 or air). Accuracy and precision were enhanced by online optical monitoring of isoprene, with absolute concentrations obtained via an absorption cross section, σisoprene = (1.28±0.06) × 10-17 cm2 molecule-1 at λ = 184.95 nm, determined in this work. These results indicate that significant discrepancies between previous absolute and relative-rate determinations of k1 result in part from σ values used to derive the isoprene concentration in high-precision absolute determinations.

Similar methods were used to determine rate coefficients (in 10-11 cm3 molecule-1 s-1) for (R2)-(R3): k2 (238-357 K) = (1.83±0.04) × exp{(330±6)/T} and k3 (235-357 K) = (2.48±0.14) × exp{(357±17)/T}. This is the first temperature-dependent dataset for (R3) and enables the calculation of reliable atmospheric lifetimes with respect to OH removal for e.g. boreal forest springtime conditions. Room temperature values of k2 (296 K) = (5.4±0.2) × 10-11 cm3 molecule-1 s-1 and k3 (297 K) = (8.1±0.3) × 10-11 cm3 molecule-1 s-1 were independent of bath-gas pressure (7-200 Torr, N2 or air) and in good agreement with previously reported values. In the course of this work, 184.95 nm absorption cross sections were determined: σ = (1.54±0.08) × 10-17 cm2 molecule-1 for α-pinene and (2.40±0.12) × 10-17 cm2 molecule-1 for Δ-3-carene.

Red blood cell acetylcholinesterase activity among healthy dwellers of an agrarian region in Sri Lanka: a descriptive cross-sectional study.

PubMed

Rathish, Devarajan; Senavirathna, Indika; Jayasumana, Channa; Agampodi, Suneth

2018-06-21

Assessment of acetylcholinesterase-inhibitor insecticide (AChEII) toxicity depends on the measurement of red blood cell acetylcholinesterase (RBC-AChE) activity. Its interpretation requires baseline values which is lacking in scientific literature. We aim to find the measures of central tendency and variation for RBC-AChE activity among dwellers of Anuradhapura, where the use and abuse of AChEIIs were rampant for the last few decades. A descriptive cross-sectional study with a community-based sampling for 100 healthy non-farmers (male:female = 1:1) was done using pre-determined selection criteria. Duplicate measurements of RBC-AChE activity were performed according to the modified Ellman procedure. Pearson's correlation and regression analysis were sort for RBC-AChE activity against its possible determinants. RBC-AChE activity had a mean of 449.8 (SD 74.2) mU/μM Hb with a statistical power of 0.847. It was similar to values of "healthy controls" from previous Sri Lankan toxicological studies but was low against international reference value [586.1 (SD 65.1) mU/μM Hb]. None of the possible determinants showed a significant strength of relationship with RBC-AChE activity. The baseline RBC-AChE activity among people of Anuradhapura is low in comparison with international reference values. This arises a need to find a causative mechanism.

Changes in tissue water and indentation resistance of lymphedematous limbs accompanying low level laser therapy (LLLT) of fibrotic skin.

PubMed

Mayrovitz, H N; Davey, S

2011-12-01

Our goal was to determine effects of low-level-laser-therapy (LLLT) on skin water and tissue indentation resistance (TIR) in patients with arm (N = 38) or leg (N = 38) lymphedema. Skin water was determined from tissue dielectric constant (TDC) measurements and TIR determined from measurements of force resulting from tissue indentations of 3-4 mm. A limb-location with fibrosis was identified by palpation and treated with an LLLT device for one minute at each of five points within a 3 cm2 area. TDC and TIR at these sites and corresponding sites on the contralateral limb were measured prior to LLLT (pre-LLLT), immediately after LLLT (post-LLLT) and after a manual lymphatic drainage (MLD) session (post-MLD). Results, from arms and legs, showed that post-LLLT values of TIR and TDC were significantly less than pre-LLLT. TIR values remained significantly reduced at post-MLD whereas TDC values were not significantly different from pre-LLLT values. On follow-up visit, 17 previously LLLT treated legs were sham treated with an inactive LLLT unit and measurements replicated. A TIR and TDC change-pattern similar to that obtained with the active LLLT was obtained, but sham-related reductions in TIR and TDC immediately post sham-treatment were significantly less than achieved with the prior active LLLT treatment.

Effective pressure law for permeability of E-bei sandstones

NASA Astrophysics Data System (ADS)

Li, M.; Bernabé, Y.; Xiao, W.-I.; Chen, Z.-Y.; Liu, Z.-Q.

2009-07-01

Laboratory experiments were conducted to determine the effective pressure law for permeability of tight sandstone rocks from the E-bei gas reservoir, China. The permeability k of five core samples was measured while cycling the confining pressure pc and fluid pressure pf. The permeability data were analyzed using the response-surface method, a statistical model-building approach yielding a representation of k in (pc, pf) space that can be used to determine the effective pressure law, i.e., peff = pc - κpf. The results show that the coefficient κ of the effective pressure law for permeability varies with confining pressure and fluid pressure as well as with the loading or unloading cycles (i.e., hysteresis effect). Moreover, κ took very small values in some of the samples, even possibly lower than the value of porosity, in contradiction with a well-accepted theoretical model. We also reanalyzed a previously published permeability data set on fissured crystalline rocks and found again that the κ varies with pc but did not observe κ values lower than 0.4, a value much larger than porosity. Analysis of the dependence of permeability on effective pressure suggests that the occurrence of low κ values may be linked to the high-pressure sensitivity of E-bei sandstones.

Sensitivity and specificity of blood leukocyte counts as an indicator of mortality in horses after colic surgery.

PubMed

Salciccia, A; Sandersen, C; Grulke, S; de la Rebière de Pouyade, G; Caudron, I; Serteyn, D; Detilleux, J

2013-09-21

The objectives of this study were to describe and relate perioperative changes in blood leukocyte counts to the outcome of surgical colic horses, determine a cut-off value in the early postoperative period to obtain an indicator of the outcome, and compare the obtained value to a validation population of horses. Fifty-three horses undergoing colic surgery were included in the descriptive part of the study. Total leukocyte counts were performed before, during and serially after surgery. A receiver operating characteristic analysis was performed on the leukocyte counts of 45 of these horses to determine a cut-off value for the outcome. The results obtained were validated on a second set of 50 horses that underwent colic surgery in similar conditions. The kinetics of blood leukocytes in survivors was higher than in non-survivors during the first days. Non-survivor horses were more likely to have at least one blood leukocyte count ≤ 3.9 × 10(3)/mm(3) between 28 and 60 hours after surgery than survivor horses. This cut-off value was confirmed in the validation population. These results suggest that routine values of blood leukocyte counts can be used as an additional prognostic indicator after colic surgery alongside other predictors previously associated with the outcome.

Solubilities of noble gases in magnetite - Implications for planetary gases in meteorites.

NASA Technical Reports Server (NTRS)

Lancet, M. S.; Anders, E.

1973-01-01

Solubilities of noble gases in magnetite were determined by growing magnetite in a noble-gas atmosphere between 450 and 700 K. Henry's law is obeyed at pressures up to .01 atm for He, Ne, Ar and up to .00001 atm for Kr, Xe, with the following distribution coefficients at 500 K: He 0.042, Ne 0.016, Ar 3.6, Kr 1.3, Xe 0.88, some 100 to 100,000 times higher than previous determinations on silicate and fluoride melts. Apparent heats of solution are in sharp contrast with earlier determinations on melts which were small and positive, but are comparable to the values for clathrates. Presumably the gases are held in anion vacancies.

Low energy e-Ar momentum transfer cross-section

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brennan, M.J.

1992-12-01

Recent work has shown that solutions of the Boltzmann equation which use the so called {open_quotes}two-term{close_quotes} approximation provide an inadequate description of the transverse diffusion of electrons in argon gas at low values of E/N, contrary to earlier evidence. Previous determinations of the momentum transfer cross section for argon from the analysis of transport data have used two-term codes in good faith. Progress towards the determination of a new cross section in the energy range O - 4 eV, including an analysis of the energy dependence of the uncertainty in the derived cross section is reported.

Physiological Strain During Load Carrying: Effects of Mass and Type of Backpack

DTIC Science & Technology

2001-05-01

load did not significantly increase the EMG signal of the trapezius shoulder muscle (pars descenders). While walking, load carrying significantly...descending part of the right trapezius muscle was measured with two surface silver-silver chloride electrodes (PPG, Hellige), positioned on the distal...values using a previously determined RMS versus force relationship. This calibration curve between RMS of the EMG of the trapezius muscle and the force

Sediment Carbon Accumulation in Southern Latitude Saltmarsh Communities of Tasmania, Australia.

PubMed

Ellison, Joanna C; Beasy, Kim M

2018-05-02

Carbon sequestration values of wetlands are greatest in their sediments. Northern hemisphere research dominates the earlier saltmarsh carbon sequestration literature, recently augmented by analyses across mainland Australia where species assemblages, catchment histories and environmental settings differ. No previous assessment has been made for Tasmania. Carbon stores and accumulation rates in saltmarsh sediments of the Rubicon estuary, Tasmania, were investigated. Carbon was determined from sediment cores by Elemental Analyser, combined with analysis of organic content and bulk density. Carbon accumulation was determined using short-term and long-term sediment accretion indicators. Results showed carbon densities to be lower than global averages, with variation found between carbon stores of native and introduced species zones. Cores from introduced Spartina anglica indicated a trend of higher sediment carbon percentages relative to cores from native saltmarsh Juncus kraussii and Sarcocornia quinqueflora , and in finer grain sizes. Sediment carbon stock of 30 cm depths was 49.5 Mg C ha −1 for native saltmarsh and 55.5 Mg C ha −1 for Spartina . Carbon percentages were low owing to high catchment inorganic sediment yields, however carbon accumulation rates were similar to global averages, particularly under Spartina . Covering 85% of saltmarsh area in the estuary, Spartina contributes the majority to carbon stores, potentially indicating a previously unrecognized value for this invasive species in Australia.

Determination of the molar extinction coefficient for the ferric reducing/antioxidant power assay.

PubMed

Hayes, William A; Mills, Daniel S; Neville, Rachel F; Kiddie, Jenna; Collins, Lisa M

2011-09-15

The FRAP reagent contains 2,4,6-tris(2-pyridyl)-s-triazine, which forms a blue-violet complex ion in the presence of ferrous ions. Although the FRAP (ferric reducing/antioxidant power) assay is popular and has been in use for many years, the correct molar extinction coefficient of this complex ion under FRAP assay conditions has never been published, casting doubt on the validity of previous calibrations. A previously reported value of 19,800 is an underestimate. We determined that the molar extinction coefficient was 21,140. The value of the molar extinction coefficient was also shown to depend on the type of assay and was found to be 22,230 under iron assay conditions, in good agreement with published data. Redox titration indicated that the ferrous sulfate heptahydrate calibrator recommended by Benzie and Strain, the FRAP assay inventors, is prone to efflorescence and, therefore, is unreliable. Ferrous ammonium sulfate hexahydrate in dilute sulfuric acid was a more stable alternative. Few authors publish their calibration data, and this makes comparative analyses impossible. A critical examination of the limited number of examples of calibration data in the published literature reveals only that Benzie and Strain obtained a satisfactory calibration using their method. Copyright © 2011 Elsevier Inc. All rights reserved.

Validity of strong lensing statistics for constraints on the galaxy evolution model

NASA Astrophysics Data System (ADS)

Matsumoto, Akiko; Futamase, Toshifumi

2008-02-01

We examine the usefulness of the strong lensing statistics to constrain the evolution of the number density of lensing galaxies by adopting the values of the cosmological parameters determined by recent Wilkinson Microwave Anisotropy Probe observation. For this purpose, we employ the lens-redshift test proposed by Kochanek and constrain the parameters in two evolution models, simple power-law model characterized by the power-law indexes νn and νv, and the evolution model by Mitchell et al. based on cold dark matter structure formation scenario. We use the well-defined lens sample from the Sloan Digital Sky Survey (SDSS) and this is similarly sized samples used in the previous studies. Furthermore, we adopt the velocity dispersion function of early-type galaxies based on SDSS DR1 and DR5. It turns out that the indexes of power-law model are consistent with the previous studies, thus our results indicate the mild evolution in the number and velocity dispersion of early-type galaxies out to z = 1. However, we found that the values for p and q used by Mitchell et al. are inconsistent with the presently available observational data. More complete sample is necessary to withdraw more realistic determination on these parameters.

Risk factors for retained placenta in southwestern Nigeria.

PubMed

Owolabi, A T; Dare, F O; Fasubaa, O B; Ogunlola, I O; Kuti, O; Bisiriyu, L A

2008-07-01

This study aimed to determine the incidence of, and identify independent risk factors to retained placenta in Ile-Ife, southwestern Nigeria. This was a prospective case-control study involving 120 women with retained placenta after vaginal birth at the Obafemi Awolowo University Teaching Hospital, Ile-Ife, southwestern Nigeria over a period of seven years. Two consecutive normal deliveries after each retained placenta served as controls. Following a bivariate analysis, a multivariate logistic regression model was constructed in order to define independent risk factors for retained placenta while controlling for confounding variables. During the study period, there were 120 cases of retained placenta, and the total number of deliveries was 6,160, making the incidence 1.9 percent. Independent risk factors associated with retained placenta include non-use of antenatal care (odds-ratio [OR] 22.71, 95 percent confidence interval [CI] 10.5-49.12, p-value is less than 0.000), previous retained placenta (OR 15.22, 95 percent CI 3.30-70.19, p-value is less than 0.000), previous caesarean section (OR 12.00, 95 percent CI 2.05-70.19, p-value is less than 0.006), maternal age 35 years or more (OR 7.10, 95 percent CI 1.5-32.40, p-values is less than 0.012), grand multiparity (OR 6.63, 95 percent CI 1.88-23.40, p-value is less than 0.003), previous dilatation and curettage (OR 4.44, 95 percent CI 1.69-11.63, p-value is less than 0.002), preterm delivery (OR 3.12, 95 percent CI 1.12-8.68, p-value is less than 0.029) and placenta weight less than 501 g (OR 2.91, 95 percent CI 1.34-6.32, p-value is less than 0.007). Women with identifiable risk factors should be targeted for the prevention of retained placenta. There is a need for the training of birth attendants in the proper conduct of delivery and third stage of labour to prevent placenta retention and postpartum haemorrhage.

Comparison of liquid chromatography-isotope ratio mass spectrometry (LC/IRMS) and gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS) for the determination of collagen amino acid δ13C values for palaeodietary and palaeoecological reconstruction.

PubMed

Dunn, Philip J H; Honch, Noah V; Evershed, Richard P

2011-10-30

Results are presented of a comparison of the amino acid (AA) δ(13)C values obtained by gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS) and liquid chromatography-isotope ratio mass spectrometry (LC/IRMS). Although the primary focus was the compound-specific stable carbon isotope analysis of bone collagen AAs, because of its growing application for palaeodietary and palaeoecological reconstruction, the results are relevant to any field where AA δ(13)C values are required. We compare LC/IRMS with the most up-to-date GC/C/IRMS method using N-acetyl methyl ester (NACME) AA derivatives. This comparison involves the analysis of standard AAs and hydrolysates of archaeological human bone collagen, which have been previously investigated as N-trifluoroacetyl isopropyl esters (TFA/IP). It was observed that, although GC/C/IRMS analyses required less sample, LC/IRMS permitted the analysis of a wider range of AAs, particularly those not amenable to GC analysis (e.g. arginine). Accordingly, reconstructed bulk δ(13)C values based on LC/IRMS-derived δ(13)C values were closer to the EA/IRMS-derived δ(13)C values than those based on GC/C/IRMS values. The analytical errors for LC/IRMS AA δ(13)C values were lower than GC/C/IRMS determinations. Inconsistencies in the δ(13)C values of the TFA/IP derivatives compared with the NACME- and LC/IRMS-derived δ(13)C values suggest inherent problems with the use of TFA/IP derivatives, resulting from: (i) inefficient sample combustion, and/or (ii) differences in the intra-molecular distribution of δ(13)C values between AAs, which are manifested by incomplete combustion. Close similarities between the NACME AA δ(13)C values and the LC/IRMS-derived δ(13)C values suggest that the TFA/IP derivatives should be abandoned for the natural abundance determinations of AA δ(13)C values. Copyright © 2011 John Wiley & Sons, Ltd.

Feminine ideology and sexual assault: are more traditional college women at greater risk?

PubMed

Wigderson, Sara; Katz, Jennifer

2015-05-01

Previous research has not conclusively determined whether traditional femininity increases women's risk for sexual assault. Certain femininity beliefs, such as valuing deference, may increase risk for sexual assault by discouraging sexual refusal assertiveness (SRA). Other femininity beliefs, such as valuing purity, may promote self-protective behaviors. College women (N = 254) provided self-report data on these beliefs, risk and protective behaviors, and sexual assault experiences. Traditional femininity was not directly associated with experiencing sexual assault. However, specific traditional beliefs were related to behaviors directly associated with risk. High SRA and sexual abstinence simultaneously reduced the odds for sexual assault. © The Author(s) 2015.

A modified fall risk assessment tool that is specific to physical function predicts falls in community-dwelling elderly people.

PubMed

Hirase, Tatsuya; Inokuchi, Shigeru; Matsusaka, Nobuou; Nakahara, Kazumi; Okita, Minoru

2014-01-01

Developing a practical fall risk assessment tool to predict the occurrence of falls in the primary care setting is important because investigators have reported deterioration of physical function associated with falls. Researchers have used many performance tests to predict the occurrence of falls. These performance tests predict falls and also assess physical function and determine exercise interventions. However, the need for such specialists as physical therapists to accurately conduct these tests limits their use in the primary care setting. Questionnaires for fall prediction offer an easy way to identify high-risk fallers without requiring specialists. Using an existing fall assessment questionnaire, this study aimed to identify items specific to physical function and determine whether those items were able to predict falls and estimate physical function of high-risk fallers. The analysis consisted of both retrospective and prospective studies and used 2 different samples (retrospective, n = 1871; prospective, n = 292). The retrospective study and 3-month prospective study comprised community-dwelling individuals aged 65 years or older and older adults using community day centers. The number of falls, risk factors for falls (15 risk factors on the questionnaire), and physical function determined by chair standing test (CST) and Timed Up and Go Test (TUGT) were assessed. The retrospective study selected fall risk factors related to physical function. The prospective study investigated whether the number of selected risk factors could predict falls. The predictive power was determined using the area under the receiver operating characteristic curve. Seven of the 15 risk factors were related to physical function. The area under the receiver operating characteristic curve for the sum of the selected risk factors of previous falls plus the other risk factors was 0.82 (P = .00). The best cutoff point was 4 risk factors, with sensitivity and specificity of 84% and 68%, respectively. The mean values for the CST and TUGT at the best cutoff point were 12.9 and 12.5 seconds, respectively. In the retrospective study, the values for the CST and TUGT corresponding to the best cutoff point from the prospective study were 13.2 and 11.4 seconds, respectively. This study confirms that a screening tool comprising 7 fall risk factors can be used to predict falls. The values for the CST and TUGT corresponding to the best cutoff point for the selected 7 risk factors determined in our prospective study were similar to the cutoff points for the CST and TUGT in previous studies for fall prediction. We propose that the sum of the selected risk factors of previous falls plus the other risk factors may be identified as the estimated value for physical function. These findings may contribute to earlier identification of high-risk fallers and intervention for fall prevention.

Glycaemic index and glycaemic load values of cereal products and weight-management meals available in the UK.

PubMed

Henry, C Jeya K; Lightowler, Helen J; Dodwell, Lis M; Wynne, Jacqueline M

2007-07-01

There is currently an increased global interest in the published glycaemic index (GI) values of foods. The aim of the present work was to supplement a previous study on the glycaemic response of 140 foods available in the UK by studying a further forty-four foods. One hundred and twenty-two healthy subjects, with a mean age of 32.4 (sd 11.4) years and a mean BMI of 23.6 (sd 3.6) kg/m2, were recruited to the study. Subjects were served equivalent available carbohydrate amounts (50 or 30 g) of test foods (cereal products and weight-management meals) and a standard food (glucose) on separate occasions. Capillary blood glucose was measured from finger-prick samples in fasted subjects (0 min) and at 15, 30, 45, 60, 90 and 120 min after starting to eat each test food. For each test food, the GI value was determined, and the glycaemic load was calculated as the product of the GI and the amount of available carbohydrate in a reference serving size. The GI values of the foods tested ranged from 23 to 83. Of the forty-four foods tested, thirty-three were classified as low-GI, eight as medium-GI and three as high-GI foods. Most GI values of the foods tested compared well with previously published values for similar foods. In summary, this study provides reliable GI and glycaemic load values for a range of foods, further advancing our understanding of the glycaemic response of different foods. The data reported here make an important addition to published GI values.

Partitioning of fluorotelomer alcohols to octanol and different sources of dissolved organic carbon.

PubMed

Carmosini, Nadia; Lee, Linda S

2008-09-01

Interest in the environmental fate of fluorotelomer alcohols (FTOHs) has spurred efforts to understand their equilibrium partitioning behavior. Experimentally determined partition coefficients for FTOHs between soil/water and air/water have been reported, but direct measurements of partition coefficients for dissolved organic carbon (DOC)/water (K(doc)) and octanol/ water(K(ow)) have been lacking. Here we measured the partitioning of 8:2 and 6:2 FTOH between one or more types of DOC and water using enhanced solubility or dialysis bag techniques, and also quantified K(ow) values for 4:2 to 8:2 FTOH using a batch equilibration method. The range in measured log K(doc) values for 8:2 FTOH using the enhanced solubility technique with DOC derived from two soils, two biosolids, and three reference humic acids is 2.00-3.97 with the lowest values obtained for the biosolids and an average across all other DOC sources (biosolid DOC excluded) of 3.54 +/- 0.29. For 6:2 FTOH and Aldrich humic acid, a log K(doc) value of 1.96 +/- 0.45 was measured using the dialysis technique. These average values are approximately 1 to 2 log units lower than previously indirectly estimated K(doc) values. Overall, the affinity for DOC tends to be slightly lower than that for particulate soil organic carbon. Measured log K(ow) values for 4:2 (3.30 +/- 0.04), 6:2 (4.54 +/- 0.01), and 8:2 FTOH (5.58 +/- 0.06) were in good agreement with previously reported estimates. Using relationships between experimentally measured partition coefficients and C-atom chain length, we estimated K(doc) and K(ow) values for shorter and longer chain FTOHs, respectively, that we were unable to measure experimentally.

Determination of the pairing-strength constants in the isovector plus isoscalar pairing case

NASA Astrophysics Data System (ADS)

Mokhtari, D.; Fellah, M.; Allal, N. H.

2016-05-01

A method for the determination of the pairing-strength constants, in the neutron-proton (n-p) isovector plus isoscalar pairing case, is proposed in the framework of the BCS theory. It is based on the fitting of these constants to reproduce the experimentally known pairing gap parameters as well as the root-mean-squared (r.m.s) charge radii values. The method is applied to some proton-rich even-even nuclei. The single-particle energies used are those of a deformed Woods-Saxon mean field. It is shown that the obtained value of the ratio GnpT=0/G npT=1 is of the same order as the ones, arbitrary chosen, of some previous works. The effect of the inclusion of the isoscalar n-p pairing in the r.m.s matter radii is then numerically studied for the same nuclei.

Solving the Value Equation: Assessing Surgeon Performance Using Risk-Adjusted Quality-Cost Diagrams and Surgical Outcomes.

PubMed

Knechtle, William S; Perez, Sebastian D; Raval, Mehul V; Sullivan, Patrick S; Duwayri, Yazan M; Fernandez, Felix; Sharma, Joe; Sweeney, John F

Quality-cost diagrams have been used previously to assess interventions and their cost-effectiveness. This study explores the use of risk-adjusted quality-cost diagrams to compare the value provided by surgeons by presenting cost and outcomes simultaneously. Colectomy cases from a single institution captured in the National Surgical Quality Improvement Program database were linked to hospital cost-accounting data to determine costs per encounter. Risk adjustment models were developed and observed average cost and complication rates per surgeon were compared to expected cost and complication rates using the diagrams. Surgeons were surveyed to determine if the diagrams could provide information that would result in practice adjustment. Of 55 surgeons surveyed on the utility of the diagrams, 92% of respondents believed the diagrams were useful. The diagrams seemed intuitive to interpret, and making risk-adjusted comparisons accounted for patient differences in the evaluation.

High-Precision Half-Life Measurement for the Superallowed {beta}{sup +} Emitter {sup 26}Al{sup m}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finlay, P.; Svensson, C. E.; Green, K. L.

2011-01-21

A high-precision half-life measurement for the superallowed {beta}{sup +} emitter {sup 26}Al{sup m} was performed at the TRIUMF-ISAC radioactive ion beam facility yielding T{sub 1/2}=6346.54{+-}0.46{sub stat{+-}}0.60{sub syst} ms, consistent with, but 2.5 times more precise than, the previous world average. The {sup 26}Al{sup m} half-life and ft value, 3037.53(61) s, are now the most precisely determined for any superallowed {beta} decay. Combined with recent theoretical corrections for isospin-symmetry-breaking and radiative effects, the corrected Ft value for {sup 26}Al{sup m}, 3073.0(12) s, sets a new benchmark for the high-precision superallowed Fermi {beta}-decay studies used to test the conserved vector current hypothesismore » and determine the V{sub ud} element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.« less

Determination of mass and heat transfer parameters during freeze-drying cycles of pharmaceutical products.

PubMed

Hottot, A; Vessot, S; Andrieu, J

2005-01-01

The principal aim of this study was to evaluate the water vapour mass transfer resistance of the dried layer and the vial heat transfer coefficient values of a pharmaceutical product during the primary drying period. First, overall vial heat transfer coefficient values, Kv, were determined by a gravimetric method based on pure ice sublimation experiments. Thus, it was possible to set up a map of the total heat flux received by each vial throughout the plate surface of our pilot scale freeze-dryer. Important heterogeneities were observed for the vials placed at the plate edges and for the vials placed at the center of the plate. As well, the same gravimetric method was also used to precisely determine the influence of main lyophilization operating parameters (shelf temperature and gas total pressure) or the vial types and sizes on these overall heat transfer coefficient values. A semi-empirical relationship as a function of total gas pressure was proposed. The transient method by pressure rise analysis (PRA method) after interrupting the water vapour flow between the sublimation chamber and the condenser, previously set up and validated in our laboratory, was then extensively used with an amorphous BSA-based formulation to identify the dried layer mass transfer resistance values, Rp, the ice front temperature, and the total heat transfer coefficient values, Kv, with or without annealing treatment. It was proved that this method gave accurate and coherent data only during the first half of the sublimation period when the totality of the vials of the set was still sublimating. Thus, this rapid method allowed estimation of, on line and in situ, the sublimation front temperature and the characterization of the morphology and structure of the freeze-dried layer, all along the first part of the sublimation period. The estimated sublimation temperatures shown by the PRA model were about 2 degrees C lower than the experimental values obtained using thermocouples inserted inside the vial, in accordance with previous data given by this method for similar freeze-drying conditions. As well, by using this method we could confirm the homogenization of the dried layer porous structure by annealing treatment after the freezing step. Furthermore, frozen matrix structure analysis (mean pore diameter) using optical microscopy and mass transfer modelling of water vapour by molecular diffusion (Knudsen regime) allowed, in some cases, to predict the experimental values of this overall mass transfer resistance directly related to the freeze-dried cake permeability.

Variations of the relative abundances of He, (C,N,O) and Fe-group nuclei in solar cosmic rays and their relationship to solar particle acceleration

NASA Technical Reports Server (NTRS)

Bertsch, D. L.; Biswas, S.; Fichtel, C. E.; Pellerin, C. J.; Reames, D. V.

1973-01-01

Measurements of the flux of helium nuclei in the 24 January 1971 event and of helium and (C,N,O) nuclei in the 1 September 1971 event are combined with previous measurements to obtain the relative abundances of helium, (C,N,O), and Fe-group nuclei in these events. These data are then summarized together with previously reported results to show that, even when the same detector system using a dE/dx plus range technique is used, differences in the He/(C,N,O) value in the same energy/nucleon interval are observed in solar cosmic ray events. Further, when the He/(C,N,O) value is lower the He/(Fe-group nuclei) value is also systematically lower in these large events. When solar particle acceleration theory is analyzed, it is seen that the results suggest that, for large events, Coulomb energy loss probably does not play a major role in determining solar particle composition at higher energies (10 MeV). The variations in multicharged nuclei composition are more likely due to partial ionization during the acceleration phase.

Conditional Tests for Localizing Trait Genes

PubMed Central

Di, Yanming; Thompson, Elizabeth A.

2009-01-01

Background/Aims With pedigree data, genetic linkage can be detected using inheritance vector tests, which explore the discrepancy between the posterior distribution of the inheritance vectors given observed trait values and the prior distribution of the inheritance vectors. In this paper, we propose conditional inheritance vector tests for linkage localization. These conditional tests can also be used to detect additional linkage signals in the presence of previously detected causal genes. Methods For linkage localization, we propose to perform inheritance vector tests conditioning on the inheritance vectors at two positions bounding a test region. We can detect additional linkage signals by conducting a further conditional test in a region with no previously detected genes. We use randomized p values to extend the marginal and conditional tests when the inheritance vectors cannot be completely determined from genetic marker data. Results We conduct simulation studies to compare and contrast the marginal and the conditional tests and to demonstrate that randomized p values can capture both the significance and the uncertainty in the test results. Conclusions The simulation results demonstrate that the proposed conditional tests provide useful localization information, and with informative marker data, the uncertainty in randomized marginal and conditional test results is small. PMID:19439976

Anchorage in Orthodontics: Three-dimensional Scanner Input.

PubMed

Nabbout, Fidele; Baron, Pascal

2018-01-01

The aim of this article is to re-evaluate anchorage coefficient values in orthodontics and their influence in the treatment decision through the usage of three-dimensional (3D) scanner. A sample of 80 patients was analyzed with the 3D scanner using the C2000 and Cepha 3DT softwares (CIRAD Montpellier, France). Tooth anatomy parameters (linear measurements, root, and crown volumes) were then calculated to determine new anchorage coefficients based on root volume. Data were collected and statistically evaluated with the StatView software (version 5.0). The anchorage coefficient values found in this study are compared to those established in previous studies. These new values affect and modify our approach in orthodontic treatment from the standpoint of anchorage. The use of new anchorage coefficient values has significant clinical implications in conventional and in microimplants-assisted orthodontic mechanics through the selection and delivery of the optimal force system (magnitude and moment) for an adequate biological response.

Unraveling the Determinants of Protrusion Formation

PubMed Central

Varghese, Mita; Gorsevski, Peter; Cayer, Marilyn L.; Boudreau, Nancy S.; Heckman, Carol A.

2012-01-01

A computerized morphometric classification technique based on latent factors reveals major protrusion classes: factors 4, 5, and 7. Previous work showed that factor 4 represented filopodia, 5 the distribution of lamellar cytoplasm, and 7 a blunt protrusion. We explore the relationship of focal contact (FC) characteristics and their integrated actin cables to factors values. The results show that FC maturation/cytoskeletal integration affects factor 5, because FC elongation/integration was correlated with its values. On the contrary, 7 values decreased with maturation, so cable or FC size or their integration must be restricted to form these protrusions. Where integration did occur, the cables showed distinctive size and orientation, as indicated by correlation of 7 values with FC shape. Results obtained with myosin inhibitors support the interpretation that a central, isometric, contractile network puts constraints on both factor 5 and 7 protrusions. We conclude that cells establish functional domains by rearranging the cytoskeleton. PMID:22500172

Association between power law coefficients of the anatomical noise power spectrum and lesion detectability in breast imaging modalities

NASA Astrophysics Data System (ADS)

Chen, Lin; Abbey, Craig K.; Boone, John M.

2013-03-01

Previous research has demonstrated that a parameter extracted from a power function fit to the anatomical noise power spectrum, β, may be predictive of breast mass lesion detectability in x-ray based medical images of the breast. In this investigation, the value of β was compared with a number of other more widely used parameters, in order to determine the relationship between β and these other parameters. This study made use of breast CT data sets, acquired on two breast CT systems developed in our laboratory. A total of 185 breast data sets in 183 women were used, and only the unaffected breast was used (where no lesion was suspected). The anatomical noise power spectrum computed from two-dimensional region of interests (ROIs), was fit to a power function (NPS(f) = α f-β), and the exponent parameter (β) was determined using log/log linear regression. Breast density for each of the volume data sets was characterized in previous work. The breast CT data sets analyzed in this study were part of a previous study which evaluated the receiver operating characteristic (ROC) curve performance using simulated spherical lesions and a pre-whitened matched filter computer observer. This ROC information was used to compute the detectability index as well as the sensitivity at 95% specificity. The fractal dimension was computed from the same ROIs which were used for the assessment of β. The value of β was compared to breast density, detectability index, sensitivity, and fractal dimension, and the slope of these relationships was investigated to assess statistical significance from zero slope. A statistically significant non-zero slope was considered to be a positive association in this investigation. All comparisons between β and breast density, detectability index, sensitivity at 95% specificity, and fractal dimension demonstrated statistically significant association with p < 0.001 in all cases. The value of β was also found to be associated with patient age and breast diameter, parameters both related to breast density. In all associations between other parameters, lower values of β were associated with increased breast cancer detection performance. Specifically, lower values of β were associated with lower breast density, higher detectability index, higher sensitivity, and lower fractal dimension values. While causality was not and probably cannot be demonstrated, the strong, statistically significant association between the β metric and the other more widely used parameters suggest that β may be considered as a surrogate measure for breast cancer detection performance. These findings are specific to breast parenchymal patterns and mass lesions only.

The effects of 2.45 GHz radio frequency energy on neurological tissue genes using an unrestrained murine model in vivo

NASA Astrophysics Data System (ADS)

Stevens, Brandon William

The effects that radio frequency (RF) energy has on the body is currently an inconclusive and controversial topic. This is in part due to the differences and issues that can be found in previous studies. This thesis describes a study on the effect of continuous RF energy on the genome of in vivo mouse brain tissue for a duration of 31 days. To address the issues found in previous studies a new standardized procedure was followed. The genome of the brain tissue was quantified using RNA-seq and then analyzed using statistical combinations and empirical p-values. Transcripts with their respective p-values were uploaded into Integrity Pathway Analysis® to determine genes associated disease and function within the brain tissue. The results from this study provided evidence that supports RF energy induces changes in the genome. Additionally, the results provided evidence of the first reported case of a potential RF-controlled genetic transistor.

Temperature estimation from hydroxyl airglow emission in the Venus night side mesosphere

NASA Astrophysics Data System (ADS)

Migliorini, A.; Snels, M.; Gérard, J.-C.; Soret, L.; Piccioni, G.; Drossart, P.

2018-01-01

The temperature of the night side of Venus at about 95 km has been determined by using spectral features of the hydroxyl airglow emission around 3 μm, recorded from July 2006 to July 2008 by VIRTIS onboard Venus Express. The retrieved temperatures vary from 145.5 to about 198.1 K with an average value of 176.3 ± 14.3 K and are in good agreement with previous ground-based and space observations. The variability with respect to latitude and local time has been studied, showing a minimum of temperature at equatorial latitudes, while temperature values increase toward mid latitudes with a local maximum at about 35°N. The present work provides an independent contribution to the temperature estimation in the transition region between the Venus upper mesosphere and the lower thermosphere, by using the OH emission as a thermometer, following the technique previously applied to the high-resolution O2(a1Δg) airglow emissions observed from ground.

The Effect on Melanoma Risk of Genes Previously Associated With Telomere Length

PubMed Central

Bishop, D. Timothy; Taylor, John C.; Hayward, Nicholas K.; Brossard, Myriam; Cust, Anne E.; Dunning, Alison M.; Lee, Jeffrey E.; Moses, Eric K.; Akslen, Lars A.; Andresen, Per A.; Avril, Marie-Françoise; Azizi, Esther; Scarrà, Giovanna Bianchi; Brown, Kevin M.; Dębniak, Tadeusz; Elder, David E.; Friedman, Eitan; Ghiorzo, Paola; Gillanders, Elizabeth M.; Goldstein, Alisa M.; Gruis, Nelleke A.; Hansson, Johan; Harland, Mark; Helsing, Per; Hočevar, Marko; Höiom, Veronica; Ingvar, Christian; Kanetsky, Peter A.; Landi, Maria Teresa; Lang, Julie; Lathrop, G. Mark; Lubiński, Jan; Mackie, Rona M.; Martin, Nicholas G.; Molven, Anders; Montgomery, Grant W.; Novaković, Srdjan; Olsson, Håkan; Puig, Susana; Puig-Butille, Joan Anton; Radford-Smith, Graham L.; Randerson-Moor, Juliette; van der Stoep, Nienke; van Doorn, Remco; Whiteman, David C.; MacGregor, Stuart; Pooley, Karen A.; Ward, Sarah V.; Mann, Graham J.; Amos, Christopher I.; Pharoah, Paul D. P.; Demenais, Florence; Law, Matthew H.; Newton Bishop, Julia A.; Barrett, Jennifer H.

2014-01-01

Telomere length has been associated with risk of many cancers, but results are inconsistent. Seven single nucleotide polymorphisms (SNPs) previously associated with mean leukocyte telomere length were either genotyped or well-imputed in 11108 case patients and 13933 control patients from Europe, Israel, the United States and Australia, four of the seven SNPs reached a P value under .05 (two-sided). A genetic score that predicts telomere length, derived from these seven SNPs, is strongly associated (P = 8.92x10-9, two-sided) with melanoma risk. This demonstrates that the previously observed association between longer telomere length and increased melanoma risk is not attributable to confounding via shared environmental effects (such as ultraviolet exposure) or reverse causality. We provide the first proof that multiple germline genetic determinants of telomere length influence cancer risk. PMID:25231748

Estimating SPT-N Value Based on Soil Resistivity using Hybrid ANN-PSO Algorithm

NASA Astrophysics Data System (ADS)

Nur Asmawisham Alel, Mohd; Ruben Anak Upom, Mark; Asnida Abdullah, Rini; Hazreek Zainal Abidin, Mohd

2018-04-01

Standard Penetration Resistance (N value) is used in many empirical geotechnical engineering formulas. Meanwhile, soil resistivity is a measure of soil’s resistance to electrical flow. For a particular site, usually, only a limited N value data are available. In contrast, resistivity data can be obtained extensively. Moreover, previous studies showed evidence of a correlation between N value and resistivity value. Yet, no existing method is able to interpret resistivity data for estimation of N value. Thus, the aim is to develop a method for estimating N-value using resistivity data. This study proposes a hybrid Artificial Neural Network-Particle Swarm Optimization (ANN-PSO) method to estimate N value using resistivity data. Five different ANN-PSO models based on five boreholes were developed and analyzed. The performance metrics used were the coefficient of determination, R2 and mean absolute error, MAE. Analysis of result found that this method can estimate N value (R2 best=0.85 and MAEbest=0.54) given that the constraint, Δ {\\bar{l}}ref, is satisfied. The results suggest that ANN-PSO method can be used to estimate N value with good accuracy.

3D temporal subtraction on multislice CT images using nonlinear warping technique

NASA Astrophysics Data System (ADS)

Ishida, Takayuki; Katsuragawa, Shigehiko; Kawashita, Ikuo; Kim, Hyounseop; Itai, Yoshinori; Awai, Kazuo; Li, Qiang; Doi, Kunio

2007-03-01

The detection of very subtle lesions and/or lesions overlapped with vessels on CT images is a time consuming and difficult task for radiologists. In this study, we have developed a 3D temporal subtraction method to enhance interval changes between previous and current multislice CT images based on a nonlinear image warping technique. Our method provides a subtraction CT image which is obtained by subtraction of a previous CT image from a current CT image. Reduction of misregistration artifacts is important in the temporal subtraction method. Therefore, our computerized method includes global and local image matching techniques for accurate registration of current and previous CT images. For global image matching, we selected the corresponding previous section image for each current section image by using 2D cross-correlation between a blurred low-resolution current CT image and a blurred previous CT image. For local image matching, we applied the 3D template matching technique with translation and rotation of volumes of interests (VOIs) which were selected in the current and the previous CT images. The local shift vector for each VOI pair was determined when the cross-correlation value became the maximum in the 3D template matching. The local shift vectors at all voxels were determined by interpolation of shift vectors of VOIs, and then the previous CT image was nonlinearly warped according to the shift vector for each voxel. Finally, the warped previous CT image was subtracted from the current CT image. The 3D temporal subtraction method was applied to 19 clinical cases. The normal background structures such as vessels, ribs, and heart were removed without large misregistration artifacts. Thus, interval changes due to lung diseases were clearly enhanced as white shadows on subtraction CT images.

Accuracy and precision of as-received implant torque wrenches.

PubMed

Britton-Vidal, Eduardo; Baker, Philip; Mettenburg, Donald; Pannu, Darshanjit S; Looney, Stephen W; Londono, Jimmy; Rueggeberg, Frederick A

2014-10-01

Previous implant torque evaluation did not determine if the target value fell within a confidence interval for the population mean of the test groups, disallowing determination of whether a specific type of wrench met a standardized goal value. The purpose of this study was to measure both the accuracy and precision of 2 different configurations (spring style and peak break) of as-received implant torque wrenches and compare the measured values to manufacturer-stated values. Ten wrenches from 4 manufacturers, representing a variety of torque-limiting mechanisms and specificity of use (with either a specific brand or universally with any brand of implant product). Drivers were placed into the wrench, and tightening torque was applied to reach predetermined values using a NIST-calibrated digital torque wrench. Five replications of measurement were made for each wrench and averaged to provide a single value from that instrument. The target torque value for each wrench brand was compared to the 95% confidence interval for the true population mean of measured values to see if it fell within the measured range. Only 1 wrench brand (Nobel Biocare) demonstrated the target torque value falling within the 95% confidence interval for the true population mean. For others, the targeted torque value fell above the 95% confidence interval (Straumann and Imtec) or below (Salvin Torq). Neither type of torque-limiting mechanism nor designation of a wrench to be used as a dedicated brand-only product or to be used as a universal product on many brands affected the ability of a wrench to deliver torque values where the true population mean included the target torque level. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

A re-assessment of the oxidation state of iron in MORB glasses

NASA Astrophysics Data System (ADS)

Berry, Andrew J.; Stewart, Glen A.; O'Neill, Hugh St. C.; Mallmann, Guilherme; Mosselmans, J. Fred W.

2018-02-01

The oxidation state of Fe, Fe/+3 ΣFe (where ΣFe =Fe2+ +Fe3+), in glass samples of mid-ocean ridge basalt (MORB), from a wide range of localities, was determined by XANES spectroscopy to be 0.10(2) (n = 42). This value is lower than that reported previously by XANES, 0.16 (1) (n = 103), but consistent with the most recent value determined by redox titrations, 0.11 (2) (n = 104), all for similar sets of samples. We attribute the anomalously high XANES value of 0.16 to a calibration error resulting from the interpretation of Mössbauer spectra and the resulting Fe/+3 ΣFe values of the standards. Our alternative interpretation removes the problem of resolving Fe/+3 ΣFe values <∼0.1 in basaltic glasses, produces isomer shift and quadrupole splitting values for Fe3+ that are independent of Fe3+/ΣFe (as is the case for Fe2+), and gives Fe/+3 ΣFe values that are consistent with the thermodynamically expected dependence on oxygen fugacity (fO2). Fe/+3Fe2+ is related to fO2 for our synthetic MORB composition by the temperature independent expression ΔQFM = 4 log ⁡ (Fe3+ /Fe2+) + 4.23 (5), where ΔQFM is the fO2 in log units relative to the quartz-fayalite-magnetite buffer. The average fO2 of natural MORB was estimated to be QFM+0.1.

A special ionisation chamber for quality control of diagnostic and mammography X ray equipment.

PubMed

Costa, A M; Caldas, L V E

2003-01-01

A quality control program for X ray equipment used for conventional radiography and mammography requires the constancy check of the beam qualities in terms of the half-value layers. In this work, a special double-faced parallel-plate ionisation chamber was developed with inner electrodes of different materials, in a tandem system. Its application will be in quality control programs of diagnostic and mammography X ray equipment for confirmation of half-value layers previously determined by the conventional method. Moreover, the chamber also may be utilised for measurements of air kerma values (and air kerma rates) in X radiation fields used for conventional radiography and mammography. The chamber was studied in relation to the characteristics of saturation, ion collection efficiency, polarity effects, leakage current, and short-term stability. The energy dependence in response of each of the two faces of the chamber was determined over the conventional radiography and mammography X ray ranges (unattenuated beams). The different energy response of the two faces of the chamber allowed the formation of a tandem system useful for the constancy check of beam qualities.

Rapid determination of surfactant critical micelle concentration in aqueous solutions using fiber-optic refractive index sensing.

PubMed

Tan, Chun Hua; Huang, Zhen Jian; Huang, Xu Guang

2010-06-01

We describe a simple and rapid method for determining the critical micelle concentration (CMC) of surfactants from fiber-optic measurements of refractive index. The refractive index of an aqueous surfactant solution was monitored as the surfactant concentration was increased using an automated dispensing system. On reaching the surfactant's CMC value, an abrupt change was observed in the rate of increase of the refractive index with increasing concentration. The measurement system provides rapid semiautomatic data collection and analysis, increasing the precision, sensitivity, and range of applicability of the technique while substantially decreasing the amount of manual intervention required. Measurements of CMC for sodium dodecyl sulfate (8.10mM), cetyltrimethylammonium chloride (1.58mM), and Triton X-100 (0.21mM) were in excellent agreement with values previously reported in the literature. The method is applicable to cationic, anionic, and nonionic surfactants, and it offers a facile, in situ, and sensitive means of detecting micelle formation over a broad range of CMC values larger than 10(-1)mM. Copyright 2010 Elsevier Inc. All rights reserved.

From the Kochen-Specker theorem to noncontextuality inequalities without assuming determinism.

PubMed

Kunjwal, Ravi; Spekkens, Robert W

2015-09-11

The Kochen-Specker theorem demonstrates that it is not possible to reproduce the predictions of quantum theory in terms of a hidden variable model where the hidden variables assign a value to every projector deterministically and noncontextually. A noncontextual value assignment to a projector is one that does not depend on which other projectors-the context-are measured together with it. Using a generalization of the notion of noncontextuality that applies to both measurements and preparations, we propose a scheme for deriving inequalities that test whether a given set of experimental statistics is consistent with a noncontextual model. Unlike previous inequalities inspired by the Kochen-Specker theorem, we do not assume that the value assignments are deterministic and therefore in the face of a violation of our inequality, the possibility of salvaging noncontextuality by abandoning determinism is no longer an option. Our approach is operational in the sense that it does not presume quantum theory: a violation of our inequality implies the impossibility of a noncontextual model for any operational theory that can account for the experimental observations, including any successor to quantum theory.

Infrared Spectroscopy of Symbiotic Stars. XI. Orbits for Southern S-type Systems: Hen 3-461, SY Mus, Hen 3-828, AND AR Pav

NASA Astrophysics Data System (ADS)

Fekel, Francis C.; Hinkle, Kenneth H.; Joyce, Richard R.; Wood, Peter R.

2017-01-01

Employing new infrared radial velocities, we have computed spectroscopic orbits of the cool giants in four southern S-type symbiotic systems. The orbits for two of the systems, Hen 3-461 and Hen 3-828, have been determined for the first time, while orbits of the other two, SY Mus and AR Pav, have previously been determined. For the latter two systems, we compare our results with those in the literature. The low mass of the secondary of SY Mus suggests that it has gone through a common envelope phase. Hen 3-461 has an orbital period of 2271 days, one of the longest currently known for S-type symbiotic systems. That period is very different from the orbital period proposed previously from its photometric variations. The other three binaries have periods between 600 and 700 day, values that are typical for S-type symbiotic orbits. Basic properties of the M giant components and the distance to each system are determined.

INFRARED SPECTROSCOPY OF SYMBIOTIC STARS. XI. ORBITS FOR SOUTHERN S-TYPE SYSTEMS: HEN 3-461, SY MUS, HEN 3-828, AND AR PAV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fekel, Francis C.; Hinkle, Kenneth H.; Joyce, Richard R.

Employing new infrared radial velocities, we have computed spectroscopic orbits of the cool giants in four southern S-type symbiotic systems. The orbits for two of the systems, Hen 3-461 and Hen 3-828, have been determined for the first time, while orbits of the other two, SY Mus and AR Pav, have previously been determined. For the latter two systems, we compare our results with those in the literature. The low mass of the secondary of SY Mus suggests that it has gone through a common envelope phase. Hen 3-461 has an orbital period of 2271 days, one of the longest currently known for S-type symbiotic systems.more » That period is very different from the orbital period proposed previously from its photometric variations. The other three binaries have periods between 600 and 700 day, values that are typical for S-type symbiotic orbits. Basic properties of the M giant components and the distance to each system are determined.« less

Investigating the Metallicity–Mixing-length Relation

NASA Astrophysics Data System (ADS)

Viani, Lucas S.; Basu, Sarbani; Joel Ong J., M.; Bonaca, Ana; Chaplin, William J.

2018-05-01

Stellar models typically use the mixing-length approximation as a way to implement convection in a simplified manner. While conventionally the value of the mixing-length parameter, α, used is the solar-calibrated value, many studies have shown that other values of α are needed to properly model stars. This uncertainty in the value of the mixing-length parameter is a major source of error in stellar models and isochrones. Using asteroseismic data, we determine the value of the mixing-length parameter required to properly model a set of about 450 stars ranging in log g, {T}eff}, and [{Fe}/{{H}}]. The relationship between the value of α required and the properties of the star is then investigated. For Eddington atmosphere, non-diffusion models, we find that the value of α can be approximated by a linear model, in the form of α /{α }ȯ =5.426{--}0.101 {log}(g)-1.071 {log}({T}eff}) +0.437([{Fe}/{{H}}]). This process is repeated using a variety of model physics, as well as compared with previous studies and results from 3D convective simulations.

Normalized value coding explains dynamic adaptation in the human valuation process.

PubMed

Khaw, Mel W; Glimcher, Paul W; Louie, Kenway

2017-11-28

The notion of subjective value is central to choice theories in ecology, economics, and psychology, serving as an integrated decision variable by which options are compared. Subjective value is often assumed to be an absolute quantity, determined in a static manner by the properties of an individual option. Recent neurobiological studies, however, have shown that neural value coding dynamically adapts to the statistics of the recent reward environment, introducing an intrinsic temporal context dependence into the neural representation of value. Whether valuation exhibits this kind of dynamic adaptation at the behavioral level is unknown. Here, we show that the valuation process in human subjects adapts to the history of previous values, with current valuations varying inversely with the average value of recently observed items. The dynamics of this adaptive valuation are captured by divisive normalization, linking these temporal context effects to spatial context effects in decision making as well as spatial and temporal context effects in perception. These findings suggest that adaptation is a universal feature of neural information processing and offer a unifying explanation for contextual phenomena in fields ranging from visual psychophysics to economic choice.

The effects of forced small-wavelength, finite-bandwidth initial perturbations and miscibility on the turbulent Rayleigh–Taylor instability

DOE PAGES

Roberts, M. S.; Jacobs, J. W.

2015-12-07

Rayleigh–Taylor instability experiments are performed using both immiscible and miscible incompressible liquid combinations having a relatively large Atwood number ofmore » $$A\\equiv ({\\it\\rho}_{2}-{\\it\\rho}_{1})/({\\it\\rho}_{2}+{\\it\\rho}_{1})=0.48$$. The liquid-filled tank is attached to a test sled that is accelerated downwards along a vertical rail system using a system of weights and pulleys producing approximately$1g$$net acceleration. The tank is backlit and images are digitally recorded using a high-speed video camera. The experiments are either initiated with forced initial perturbations or are left unforced. The forced experiments have an initial perturbation imposed by vertically oscillating the liquid-filled tank to produce Faraday waves at the interface. The unforced experiments rely on random interfacial fluctuations, resulting from background noise, to seed the instability. The main focus of this study is to determine the effects of forced initial perturbations and the effects of miscibility on the growth parameter,$${\\it\\alpha}$$. Measurements of the mixing-layer width,$$h$$, are acquired, from which$${\\it\\alpha}$$is determined. It is found that initial perturbations of the form used in this study do not affect measured$${\\it\\alpha}$$values. However, miscibility is observed to strongly affect$${\\it\\alpha}$$, resulting in a factor of two reduction in its value, a finding not previously observed in past experiments. In addition, all measured$${\\it\\alpha}$values are found to be smaller than those obtained in previous experimental studies.« less

Development of a simple chromatographic method for the determination of piracetam in human plasma and its pharmacokinetic evaluation.

PubMed

Barkat, K; Ahmad, M; Minhas, M U; Malik, M Z; Sohail, M

2014-07-01

The objective of study was to develop an accurate and reproducible HPLC method for determination of piracetam in human plasma and to evaluate pharmacokinetic parameters of 800 mg piracetam. A simple, rapid, accurate, precise and sensitive high pressure liquid chromatography method has been developed and subsequently validated for determination of piracetam. This study represents the results of a randomized, single-dose and single-period in 18 healthy male volunteers to assess pharmacokinetic parameters of 800 mg piracetam tablets. Various pharmacokinetic parameters were determined from plasma for piracetam and found to be in good agreement with previous reported values. The data was analyzed by using Kinetica® version 4.4 according to non-compartment model of pharmacokinetic analysis and after comparison with previous studies, no significant differences were found in present study of tested product. The major pharmacokinetic parameters for piracetam were as follows: t1/2 was (4.40 ± 0.179) h; Tmax value was (2.33 ± 0.105) h; Cmax was (14.53 ± 0.282) µg/mL; the AUC(0-∞) was (59.19 ± 4.402) µg · h/mL. AUMC(0-∞) was (367.23 ± 38.96) µg. (h)(2)/mL; Ke was (0.16 ± 0.006) h; MRT was (5.80 ± 0.227) h; Vd was (96.36 ± 8.917 L). A rapid, accurate and precise high pressure liquid chromatography method was developed and validated before the study. It is concluded that this method is very useful for the analysis of pharmacokinetic parameters, in human plasma and assured the safety and efficacy of piracetam, can be effectively used in medical practice. © Georg Thieme Verlag KG Stuttgart · New York.

Surgical therapy of canine nasal tumors: A retrospective study (1982-1986)

PubMed Central

Laing, Elizabeth J.; Binnington, Allen G.

1988-01-01

The results of surgical therapy in 15 dogs with histologically confirmed nasal tumors were analyzed retrospectively and compared to previous reports. Median survival time for all dogs was seven months. When adjusted for nontumor-related deaths, median survival increased to nine months. These values are two to three times longer than previous reports. To determine possible prognostic indicators, tumor stage, location, and histological type were compared to survival time. Dogs with unilateral nasal tumors had a median survival of 11 months, as compared to three months for dogs with bilateral tumors (p = 0.005). Tumor stage and histological type were not significant factors in comparing survival times. PMID:17423139

Thermal expansion in UO 2 determined by high-energy X-ray diffraction

DOE PAGES

Guthrie, M.; Benmore, C. J.; Skinner, L. B.; ...

2016-06-24

In this study, we present crystallographic analyses of high-energy X-ray diffraction data on polycrystalline UO 2 up to the melting temperature. The Rietveld refinements of our X-ray data are in agreement with previous measurements, but are systematically located around the upper bound of their uncertainty, indicating a slightly steeper trend of thermal expansion compared to established values. This observation is consistent with recent first principles calculations.

Environmental Aspects of Artificial Aeration and Oxygenation of Reservoirs: A Review of Theory, Techniques, and Experiences.

DTIC Science & Technology

1982-05-01

Characteristics of USAE Reservoirs and Artificially Mixed Reservoirs 143 4 19 Correlation Matrix for USAE Reservoir Characteristics 149 20 Disadvantages...previously. The pH of water has additional roles in directly determining species distributions and in controlling activity of phytoplankton diseases. 143 ...see text under "Review of Mixing Experiences" for explanation). c Range of median values from three sampling dates during summer. 143

Refraction near the horizon

NASA Technical Reports Server (NTRS)

Schaefer, Bradley E.; Liller, William

1990-01-01

Variations in astronomical refraction near the horizon are examined. Sunset timings, a sextant mounted on a tripod, and a temperature profile are utilized to derive the variations in refraction data, collected from 7 locations. It is determined that the refraction ranges from 0.234 to 1.678 deg with an rms deviation of 0.16, and it is observed that the variation is larger than previously supposed. Some applications for the variation of refraction value are discussed.

Studies of CO oxidation on Pt/SnO2 catalyst in a surrogate CO2 laser facility

NASA Technical Reports Server (NTRS)

Batten, Carmen E.; Miller, Irvin M.; Paulin, Patricia A.; Schryer, Jacqueline

1987-01-01

Samples of 1% Pt/SnO2 catalyst were exposed to a stoichiometric gas mixture of 1% CO and 1.2% O2 in helium over a range of flowrates from 5 to 15 sccm and temperatures from 338 to 394 Kelvin. Reaction rate constants for the catalytic oxidation of carbon monoxide and their temperature dependence were determined and compared with previous literature values.

Quantitative Chemical Exchange Saturation Transfer MRI of Intervertebral Disc in a Porcine Model

PubMed Central

Zhou, Zhengwei; Bez, Maxim; Tawackoli, Wafa; Giaconi, Joseph; Sheyn, Dmitriy; de Mel, Sandra; Maya, Marcel M.; Pressman, Barry D.; Gazit, Zulma; Pelled, Gadi; Gazit, Dan; Li, Debiao

2017-01-01

Purpose Previous studies have associated low pH in interver-tebral discs (IVDs) with discogenic back pain. The purpose of this study was to determine whether quantitative CEST (qCEST) MRI can be used to detect pH changes in IVDs in vivo. Methods The exchange rate ksw between glycosaminoglycan (GAG) protons and water protons was determined from qCEST analysis. Its dependence on pH value was investigated in GAG phantoms with varying pH and concentrations. The relationship between ksw and pH was studied further in vivo in a porcine model on a 3T MR scanner and validated using a pH meter. Sodium lactate was injected into the IVDs to induce various pH values within the discs ranging from 5 to 7. Results Phantom and animal results revealed that ksw measured using qCEST MRI is highly correlated with pH level. In the animal studies, the relationship can be described as ksw =9.2 × 106 × 10−pH + 196.9, R2 = 0.7883. Conclusion The exchange rate between GAG and water protons determined from qCEST MRI is closely correlated with pH value. This technique has the potential to noninvasively measure pH in the IVDs of patients with discogenic pain. PMID:27670140

Selective visual attention and motivation: the consequences of value learning in an attentional blink task.

PubMed

Raymond, Jane E; O'Brien, Jennifer L

2009-08-01

Learning to associate the probability and value of behavioral outcomes with specific stimuli (value learning) is essential for rational decision making. However, in demanding cognitive conditions, access to learned values might be constrained by limited attentional capacity. We measured recognition of briefly presented faces seen previously in a value-learning task involving monetary wins and losses; the recognition task was performed both with and without constraints on available attention. Regardless of available attention, recognition was substantially enhanced for motivationally salient stimuli (i.e., stimuli highly predictive of outcomes), compared with equally familiar stimuli that had weak or no motivational salience, and this effect was found regardless of valence (win or loss). However, when attention was constrained (because stimuli were presented during an attentional blink, AB), valence determined recognition; win-associated faces showed no AB, but all other faces showed large ABs. Motivational salience acts independently of attention to modulate simple perceptual decisions, but when attention is limited, visual processing is biased in favor of reward-associated stimuli.

Soil conservation service curve number: How to take into account spatial and temporal variability

NASA Astrophysics Data System (ADS)

Rianna, M.; Orlando, D.; Montesarchio, V.; Russo, F.; Napolitano, F.

2012-09-01

The most commonly used method to evaluate rainfall excess, is the Soil Conservation Service (SCS) runoff curve number model. This method is based on the determination of the CN valuethat is linked with a hydrological soil group, cover type, treatment, hydrologic condition and antecedent runoff condition. To calculate the antecedent runoff condition the standard procedure needs to calculate the rainfall over the entire basin during the five days previous to the beginning of the event in order to simulate and then to use that volume of rainfall to calculate the antecedent moisture condition (AMC). This is necessary in order to obtain the correct curve number value. The value of the modified parameter is then kept constant throughout the whole event. The aim of this work is to evaluate the possibility of improving the curve number method. The various assumptions are focused on modifying those related to rainfall and the determination of an AMC condition and their role in the determination of the value of the curve number parameter. In order to consider the spatial variability we assumed that the rainfall which influences the AMC and the CN value does not account for the rainfall over the entire basin, but for the rainfall within a single cell where the basin domain is discretized. Furthermore, in order to consider the temporal variability of rainfall we assumed that the value of the CN of the single cell is not maintained constant during the whole event, but instead varies throughout it according to the time interval used to define the AMC conditions.

Accuracy and adequacy of waist circumference cut-off points currently recommended in Brazilian adults.

PubMed

Vianna, Carolina Avila; da Silva Linhares, Rogério; Bielemann, Renata Moraes; Machado, Eduardo Coelho; González-Chica, David Alejandro; Matijasevich, Alicia Manitto; Gigante, Denise Petrucci; da Silva Dos Santos, Iná

2014-04-01

To evaluate the adequacy and accuracy of cut-off values currently recommended by the WHO for assessment of cardiovascular risk in southern Brazil. Population-based study aimed at determining the predictive ability of waist circumference for cardiovascular risk based on the use of previous medical diagnosis for hypertension, diabetes mellitus and/or dyslipidaemia. Descriptive analysis was used for the adequacy of current cut-off values of waist circumference, receiver operating characteristic curves were constructed and the most accurate criteria according to the Youden index and points of optimal sensitivity and specificity were identified. Pelotas, southern Brazil. Individuals (n 2112) aged ≥20 years living in the city were selected by multistage sampling, since these individuals did not report the presence of previous myocardial infarction, angina pectoris or stroke. The cut-off values currently recommended by WHO were more appropriate in men than women, with overestimation of cardiovascular risk in women. The area under the receiver operating characteristic curve showed moderate predictive ability of waist circumference in men (0.74, 95% CI 0.71, 0.76) and women (0.75, 95% CI 0.73, 0.77). The method of optimal sensitivity and specificity showed better performance in assessing the accuracy, identifying the values of 95 cm in men and 87 cm in women as the best cut-off values of waist circumference to assess cardiovascular risk. The cut-off values currently recommended for waist circumference are not suitable for women. Longitudinal studies should be conducted to evaluate the consistency of the findings.

Assessment of interchangeability rate between 2 methods of measurements: An example with a cardiac output comparison study.

PubMed

Lorne, Emmanuel; Diouf, Momar; de Wilde, Robert B P; Fischer, Marc-Olivier

2018-02-01

The Bland-Altman (BA) and percentage error (PE) methods have been previously described to assess the agreement between 2 methods of medical or laboratory measurements. This type of approach raises several problems: the BA methodology constitutes a subjective approach to interchangeability, whereas the PE approach does not take into account the distribution of values over a range. We describe a new methodology that defines an interchangeability rate between 2 methods of measurement and cutoff values that determine the range of interchangeable values. We used a simulated data and a previously published data set to demonstrate the concept of the method. The interchangeability rate of 5 different cardiac output (CO) pulse contour techniques (Wesseling method, LiDCO, PiCCO, Hemac method, and Modelflow) was calculated, in comparison with the reference pulmonary artery thermodilution CO using our new method. In our example, Modelflow with a good interchangeability rate of 93% and a cutoff value of 4.8 L min, was found to be interchangeable with the thermodilution method for >95% of measurements. Modelflow had a higher interchangeability rate compared to Hemac (93% vs 86%; P = .022) or other monitors (Wesseling cZ = 76%, LiDCO = 73%, and PiCCO = 62%; P < .0001). Simulated data and reanalysis of a data set comparing 5 CO monitors against thermodilution CO showed that, depending on the repeatability of the reference method, the interchangeability rate combined with a cutoff value could be used to define the range of values over which interchangeability remains acceptable.

Application of the VALUE communication principles in ACTIVE hospice team meetings.

PubMed

Washington, Karla T; Wittenberg-Lyles, Elaine; Parker Oliver, Debra; Demiris, George; Shaunfield, Sara; Crumb, Edith

2013-01-01

The ACTIVE (Assessing Caregivers for Team Intervention through Video Encounters) intervention uses technology to enable family caregivers to participate in hospice interdisciplinary team (IDT) meetings from geographically remote locations. Previous research has suggested that effective communication is critical to the success of these meetings. The purpose of this study was to explore communication in ACTIVE IDT meetings involving family caregivers and to assess the degree to which hospice teams use specific communication principles (summarized in the mnemonic VALUE: value, acknowledge, listen, understand, and elicit), which have been supported in previous research in intensive care settings. Researchers analyzed team-family communication during 84 video- and/or audio-recorded care plan discussions that took place during ACTIVE team meetings, using a template approach to text analysis to determine the extent and quality of VALUE principles. The total content analyzed was 9 hours, 28 minutes in length. Hospice clinicians routinely employed the VALUE communication principles in communication during ACTIVE IDT meetings with family caregivers, but the quality of this communication was frequently rated moderate or poor. The majority of such communication was task-focused. Less often, communication centered on emotional concerns and efforts to gain a more holistic understanding of patients and families. This analysis suggests an opportunity for improving support for family members during ACTIVE IDT meetings. Members of hospice IDTs should remain aware of the opportunity for additional attention to the emotional realities of the hospice experience for family caregivers and could improve support for family caregivers during IDT meetings by ensuring that messages used to exemplify VALUE principles during team-family communication are of a high quality.

Influence of critical closing pressure on systemic vascular resistance and total arterial compliance: A clinical invasive study.

PubMed

Chemla, Denis; Lau, Edmund M T; Hervé, Philippe; Millasseau, Sandrine; Brahimi, Mabrouk; Zhu, Kaixian; Sattler, Caroline; Garcia, Gilles; Attal, Pierre; Nitenberg, Alain

2017-12-01

Systemic vascular resistance (SVR) and total arterial compliance (TAC) modulate systemic arterial load, and their product is the time constant (Tau) of the Windkessel. Previous studies have assumed that aortic pressure decays towards a pressure asymptote (P∞) close to 0mmHg, as right atrial pressure is considered the outflow pressure. Using these assumptions, aortic Tau values of ∼1.5seconds have been documented. However, a zero P∞ may not be physiological because of the high critical closing pressure previously documented in vivo. To calculate precisely the Tau and P∞ of the Windkessel, and to determine the implications for the indices of systemic arterial load. Aortic pressure decay was analysed using high-fidelity recordings in 16 subjects. Tau was calculated assuming P∞=0mmHg, and by two methods that make no assumptions regarding P∞ (the derivative and best-fit methods). Assuming P∞=0mmHg, we documented a Tau value of 1372±308ms, with only 29% of Windkessel function manifested by end-diastole. In contrast, Tau values of 306±109 and 353±106ms were found from the derivative and best-fit methods, with P∞ values of 75±12 and 71±12mmHg, and with ∼80% completion of Windkessel function. The "effective" resistance and compliance were ∼70% and ∼40% less than SVR and TAC (area method), respectively. We did not challenge the Windkessel model, but rather the estimation technique of model variables (Tau, SVR, TAC) that assumes P∞=0. The study favoured a shorter Tau of the Windkessel and a higher P∞ compared with previous studies. This calls for a reappraisal of the quantification of systemic arterial load. Crown Copyright © 2017. Published by Elsevier Masson SAS. All rights reserved.

The Measurement of Subjective Value and Its Relation to Contingent Valuation and Environmental Public Goods

PubMed Central

Khaw, Mel W.; Grab, Denise A.; Livermore, Michael A.; Vossler, Christian A.; Glimcher, Paul W.

2015-01-01

Environmental public goods—including national parks, clean air/water, and ecosystem services—provide substantial benefits on a global scale. These goods have unique characteristics in that they are typically “nonmarket” goods, with values from both use and passive use that accrue to a large number of individuals both in current and future generations. In this study, we test the hypothesis that neural signals in areas correlated with subjective valuations for essentially all other previously studied categories of goods (ventromedial prefrontal cortex and ventral striatum) also correlate with environmental valuations. We use contingent valuation (CV) as our behavioral tool for measuring valuations of environmental public goods. CV is a standard stated preference approach that presents survey respondents with information on an issue and asks questions that help policymakers determine how much citizens are willing to pay for a public good or policy. We scanned human subjects while they viewed environmental proposals, along with three other classes of goods. The presentation of all four classes of goods yielded robust and similar patterns of temporally synchronized brain activation within attentional networks. The activations associated with the traditional classes of goods replicate previous correlations between neural activity in valuation areas and behavioral preferences. In contrast, CV-elicited values for environmental proposals did not correlate with brain activity at either the individual or population level. For a sub-population of participants, CV-elicited values were correlated with activity within the dorsomedial prefrontal cortex, a region associated with cognitive control and shifting decision strategies. The results show that neural activity associated with the subjective valuation of environmental proposals differs profoundly from the neural activity associated with previously examined goods and preference measures. PMID:26221734

Identification and yields of 1,4-hydroxynitrates formed from the reactions of C8-C16 n-alkanes with OH radicals in the presence of NO(x).

PubMed

Yeh, Geoffrey K; Ziemann, Paul J

2014-09-25

A series of C8-C16 n-alkanes were reacted with OH radicals in the presence of NOx in an environmental chamber and particulate 1,4-hydroxynitrate reaction products were collected by filtration, extracted, and analyzed by high-performance liquid chromatography with UV absorption and electron ionization mass spectrometry (HPLC/UV/MS). Observed mass spectral patterns can be explained by using proposed ion fragmentation mechanisms, permitting the identification of each hydroxynitrate isomer. Reversed-phase retention of these compounds was dictated by the length of the longer of two alkyl chains attached to the 1,4-hydroxynitrate subunit. 1,4-Hydroxynitrates were quantified in particles using an authentic analytical standard for calibration, and the results were combined with gas chromatography measurements of the n-alkanes to determine the molar yields. Yields based on analyses of particles increased with increasing carbon number from 0.00 for C8 to an average plateau value of 0.130 ± 0.008 for C14-C16, due primarily to corresponding increases in gas-to-particle partitioning. The value at the plateau, where essentially all 1,4-hydroxynitrates were in particles, was equal to the average total yield of C14-C16 1,4-hydroxynitrates. The average branching ratio for the formation of C14-C16 1,4-hydroxynitrates from the reaction of NO with the corresponding 1,4-hydroxyperoxy radicals was 0.184 ± 0.011. This value is ∼20% higher than the plateau value of 0.15 for reactions of secondary 1,2-hydroxyperoxy radicals and ∼40% lower than the plateau value of 0.29 for reactions of secondary alkyl peroxy radicals, both of which were reported previously. The branching ratios determined here were used with values reported previously to calculate the yields of C7-C18 alkyl nitrates, 1,4-hydroxynitrates, and 1,4-hydroxycarbonyls, the three products formed from the reactions of these n-alkanes.

Charmed and light pseudoscalar meson decay constants from four-flavor lattice QCD with physical light quarks

DOE PAGES

Bazavov, A.; Bernard, C.; Komijani, J.; ...

2014-10-30

We compute the leptonic decay constants f D+, f Ds , and f K+, and the quark-mass ratios m c=m s and m s=m l in unquenched lattice QCD using the experimentally determined value of f π+ for normalization. We use the MILC Highly Improved Staggered Quark (HISQ) ensembles with four dynamical quark flavors -- up, down, strange, and charm -- and with both physical and unphysical values of the light sea-quark masses. The use of physical pions removes the need for a chiral extrapolation, thereby eliminating a significant source of uncertainty in previous calculations. Four different lattice spacing ranging from a ≈ 0:06 fm to 0:15 fm are included in the analysis to control the extrapolation to the continuum limit. Our primary results are f D+ = 212:6(0:4)more » $$(^{+1.0}_{-1.2})$$ MeV, f Ds = 249:0(0:3)$$(^{+1.1}_{-1.5})$$ MeV, and f Ds/f D+ = 1:1712(10)$$(^{+29}_{-32})$$, where the errors are statistical and total systematic, respectively. The errors on our results for the charm decay constants and their ratio are approximately two to four times smaller than those of the most precise previous lattice calculations. We also obtain f K+/ f π+ = 1:1956(10)$$(^{+26}_{-18})$$, updating our previous result, and determine the quark-mass ratios m s/m l = 27:35(5)$$(^{+10}_{-7})$$ and m c/m s = 11:747(19)$$(^{+59}_{-43})$$. When combined with experimental measurements of the decay rates, our results lead to precise determinations of the CKM matrix elements !Vus! = 0:22487(51)(29)(20)(5), !Vcd! = 0:217(1)(5)(1) and !Vcs! = 1:010(5)(18)(6), where the errors are from this calculation of the decay constants, the uncertainty in the experimental decay rates, structure-dependent electromagnetic corrections, and, in the case of !Vus!, the uncertainty in |Vud|, respectively.« less

Nuclear DNA Variation, Chromosome Numbers and Polyploidy in the Endemic and Indigenous Grass Flora of New Zealand

PubMed Central

MURRAY, B. G.; DE LANGE, P. J.; FERGUSON, A. R.

2005-01-01

• Background and Aims Little information is available on DNA C-values for the New Zealand flora. Nearly 85 % of the named species of the native vascular flora are endemic, including 157 species of Poaceae, the second most species-rich plant family in New Zealand. Few C-values have been published for New Zealand native grasses, and chromosome numbers have previously been reported for fewer than half of the species. The aim of this research was to determine C-values and chromosome numbers for most of the endemic and indigenous Poaceae from New Zealand. • Scope To analyse DNA C-values from 155 species and chromosome numbers from 55 species of the endemic and indigenous grass flora of New Zealand. • Key Results The new C-values increase significantly the number of such measurements for Poaceae worldwide. New chromosome numbers were determined from 55 species. Variation in C-value and percentage polyploidy were analysed in relation to plant distribution. No clear relationship could be demonstrated between these variables. • Conclusions A wide range of C-values was found in the New Zealand endemic and indigenous grasses. This variation can be related to the phylogenetic position of the genera, plants in the BOP (Bambusoideae, Oryzoideae, Pooideae) clade in general having higher C-values than those in the PACC (Panicoideae, Arundinoideae, Chloridoideae + Centothecoideae) clade. Within genera, polyploids typically have smaller genome sizes (C-value divided by ploidy level) than diploids and there is commonly a progressive decrease with increasing ploidy level. The high frequency of polyploidy in the New Zealand grasses was confirmed by our additional counts, with only approximately 10 % being diploid. No clear relationship between C-value, polyploidy and rarity was evident. PMID:16243852

Comparing the solar magnetic field in the corona and in the inner heliosphere during solar cycles 21-23

NASA Astrophysics Data System (ADS)

Virtanen, I. I.; Mursula, K.

2009-04-01

We compare the open solar magnetic field estimated by the PFSS model based on the WSO photospheric field observations, with the inner heliospheric magnetic field. We trace the observed radial HMF into the coronal PFSS boundary at 2.5 solar radii using the observed solar wind velocity, and determine the PFSS model field at the line-of-sight footpoint. Comparing the two field values, we calculate the power n of the apparent decrease of the radial field. According to expectations based on Maxwell's equations, also reproduced by Parker's HMF model, the radial HMF field should decrease with n=2. However, comparison gives considerably lower values of n, indicating the effect of HCS in the PFSS model and the possible superexpansion. The n values vary with solar cycle, being roughly 1.3-1.4 at minima and about 1.7 at maxima. Interestingly, the n values for the two HMF sectors show systematic differences in the late declining to minimum phase, with smaller n values for the HMF sector dominant in the northern hemisphere. This is in agreement with the smaller field value in the northern hemisphere and the southward shifted HCS, summarized by the concept of the bashful ballerina. We also find that the values of n during the recent years, in the late declining phase of solar cycle 23, are significantly larger than during the same phase of the previous cycles. This agrees with the exceptionally large tilt of the solar dipole at the end of cycle 23. We also find that the bashful ballerina appears even during SC 23 but the related hemispheric differences are smaller than during the previous cycles.

Determination of Earth rotation by the combination of data from different space geodetic systems

NASA Technical Reports Server (NTRS)

Archinal, Brent Allen

1987-01-01

Formerly, Earth Rotation Parameters (ERP), i.e., polar motion and UTI-UTC values, have been determined using data from only one observational system at a time, or by the combination of parameters previously obtained in such determinations. The question arises as to whether a simultaneous solution using data from several sources would provide an improved determination of such parameters. To pursue this reasoning, fifteen days of observations have been simulated using realistic networks of Lunar Laser Ranging (LLR), Satellite Laser Ranging (SLR) to Lageos, and Very Long Baseline Interferometry (VLBI) stations. A comparison has been done of the accuracy and precision of the ERP obtained from: (1) the individual system solutions, (2) the weighted means of those values, (3) all of the data by means of the combination of the normal equations obtained in 1, and (4) a grand solution with all the data. These simulations show that solutions done by the normal equation combination and grand solution methods provide the best or nearly the best ERP for all the periods considered, but that weighted mean solutions provide nearly the same accuracy and precision. VLBI solutions also provide similar accuracies.

Critical line of 2+1 flavor QCD

NASA Astrophysics Data System (ADS)

Cea, Paolo; Cosmai, Leonardo; Papa, Alessandro

2014-04-01

We determine the curvature of the (pseudo)critical line of QCD with nf = 2 + 1 staggered fermions at nonzero temperature and quark density by analytic continuation from imaginary chemical potentials. Monte Carlo simulations are performed by adopting the highly improved staggered quarks /tree action discretization, as implemented in the code by the MILC Collaboration, suitably modified to include a nonzero imaginary baryon chemical potential. We work on a line of constant physics, as determined in Ref. [1], adjusting the couplings so as to keep the strange quark mass ms fixed at its physical value, with a light to strange mass ratio of ml/ms=1/20. In the present investigation, we set the chemical potential at the same value for the three quark species, μl=μs≡μ. We explore lattices of different spatial extensions, 163×6 and 243×6, to check for finite size effects, and present results on a 323×8 lattice, to check for finite cutoff effects. We discuss our results for the curvature κ of the (pseudo)critical line at μ =0, which indicate κ=0.018(4), and compare them with previous lattice determinations by alternative methods and with experimental determinations of the freeze-out curve.

Determination of the fundamental properties of an M31 globular cluster from main-sequence photometry

NASA Astrophysics Data System (ADS)

Ma, Jun

2013-02-01

We determined the age of the M31 globular cluster B379 using isochrones of the Padova stellar evolutionary models. At the same time, the cluster's metal abundance, its distance modulus, and reddening value were also obtained. The results obtained in this paper are consistent with previous determinations, including the age. Brown et al. constrained the age of B379 by comparing its color-magnitude diagram with isochrones of the 2006 VandenBerg models. Therefore, this paper confirms the consistency of the age scale of B379 between the Padova isochrones and the 2006 VandenBerg isochrones. The results of B379 obtained in this paper are: metallicity [M/H] = log(Z/Z⊙) = -0.325 dex, age τ = 11.0 +/- 1.5 Gyr, reddening E(B - V) = 0.08 mag, and distance modulus (m - M)0 = 24.44 +/- 0.10 mag. Using the metallicity, the reddening value and the distance modulus obtained in this paper, we constrained the age of B379 by comparing its multicolor photometry with theoretical stellar population synthesis models. The age of B379 obtained is 10.6-0.76 +0.92 Gyr, which is in very good agreement with the determination from main-sequence photometry.

A new method to determine the interstellar reddening towards WN stars

NASA Technical Reports Server (NTRS)

Conti, Peter S.; Morris, Patrick W.

1990-01-01

An empirical approach to determine the redding in WN stars is presented, in which the measured strengths of the emission lines of He II at 1640 and 4686 A are used to estimate the extinction. The He II emission lines at these wavelengths are compared for a number of WN stars in the Galaxy and the LMC. It is shown that the equivalent width ratios are single valued and are independent of the spectral subtypes. The reddening for stars in the Galaxy is derived using a Galactic extinction law and observed line flux ratios, showing good agreement with previous determinations of reddening. The possible application of the method to study the absorption properties of the interstellar medium in more distant galaxies is discussed.

Determination of the thermal stability of fluids by tensimetry - Instrumentation and procedure

NASA Technical Reports Server (NTRS)

Helmick, Larry S.; Jones, William R., Jr.

1990-01-01

A computerized tensimeter and experimental procedure for determination of the thermal decomposition temperature (T sub d) of perfluoro alkylethers were developed and tested. Both the apparatus and the procedure are described in detail. Results of testing with bis(2-ethylhexyl) phthalate and trimethylolpropane triheptanoate demonstrate that the reciprocal of the decomposition temperature is a linear function of the logarithm of the gas volume/heated liquid volume ratio. The T sub d obtained for each compound at a gas volume/heated liquid volume ration of one was similar to the value previously reported using an isoteniscope technique. Results of testing with a polymer of hexafluoropropylene oxide demonstrate that this instrument and procedure can be used to determine the T sub d of perfluoro alkylethers.

Determination of the thermal stability of perfluoroalkylethers by tensimetry: Instrumentation and Procedure

NASA Technical Reports Server (NTRS)

Helmick, Larry S.; Jones, William R., Jr.

1989-01-01

A computerized tensimeter and experimental procedure for determination of the thermal decomposition temperature (T sub d) of perfluoro alkylethers were developed and tested. Both the apparatus and the procedure are described in detail. Results of testing with bis(2-ethylhexyl) phthalate and trimethylolpropane triheptanoate demonstrate that the reciprocal of the decomposition temperature is a linear function of the logarithm of the gas volume/heated liquid volume ratio. The T sub d obtained for each compound at a gas volume/heated liquid volume ration of one was similar to the value previously reported using an isoteniscope technique. Results of testing with a polymer of hexafluoropropylene oxide demonstrate that this instrument and procedure can be used to determine the T sub d of perfluoroalkylethers.

Motivational and emotional profiles in university undergraduates: a self-determination theory perspective.

PubMed

González, Antonio; Paoloni, Verónica; Donolo, Danilo; Rinaudo, Cristina

2012-11-01

Previous research has focused on specific forms of self-determined motivation or discrete class-related emotions, but few studies have simultaneously examined both constructs. The aim of this study on 472 undergraduates was twofold: to perform cluster analysis to identify homogeneous groups of motivation in the sample; and to determine the profile of each cluster for emotions and academic achievement. Cluster analysis configured four groups in terms of motivation: controlled, autonomous, both high, and both low. Each cluster revealed a distinct emotional profile, autonomous motivation being the most adaptable with high scores for academic achievement and pleasant emotions and low values for unpleasant emotions. The results are discussed in the light of their implications for academic adjustment.

Predicting the Performance of Chain Saw Machines Based on Shore Scleroscope Hardness

NASA Astrophysics Data System (ADS)

Tumac, Deniz

2014-03-01

Shore hardness has been used to estimate several physical and mechanical properties of rocks over the last few decades. However, the number of researches correlating Shore hardness with rock cutting performance is quite limited. Also, rather limited researches have been carried out on predicting the performance of chain saw machines. This study differs from the previous investigations in the way that Shore hardness values (SH1, SH2, and deformation coefficient) are used to determine the field performance of chain saw machines. The measured Shore hardness values are correlated with the physical and mechanical properties of natural stone samples, cutting parameters (normal force, cutting force, and specific energy) obtained from linear cutting tests in unrelieved cutting mode, and areal net cutting rate of chain saw machines. Two empirical models developed previously are improved for the prediction of the areal net cutting rate of chain saw machines. The first model is based on a revised chain saw penetration index, which uses SH1, machine weight, and useful arm cutting depth as predictors. The second model is based on the power consumed for only cutting the stone, arm thickness, and specific energy as a function of the deformation coefficient. While cutting force has a strong relationship with Shore hardness values, the normal force has a weak or moderate correlation. Uniaxial compressive strength, Cerchar abrasivity index, and density can also be predicted by Shore hardness values.

Translational MRI Volumetry with NeuroQuant: Effects of Version and Normative Data on Relationships with Memory Performance in Healthy Older Adults and Patients with Mild Cognitive Impairment.

PubMed

Stelmokas, Julija; Yassay, Lance; Giordani, Bruno; Dodge, Hiroko H; Dinov, Ivo D; Bhaumik, Arijit; Sathian, K; Hampstead, Benjamin M

2017-01-01

NeuroQuant (NQ) is a fully-automated program that overcomes several existing limitations in the clinical translation of MRI-derived volumetry. The current study characterized differences between the original (NQ1) and an updated NQ version (NQ2) by 1) replicating previously identified relationships between neuropsychological test performance and medial temporal lobe volumes, 2) evaluating the level of agreement between NQ versions, and 3) determining if the addition of NQ2 age-/sex-based z-scores hold greater clinical utility for prediction of memory impairment than standard percent of intracranial volume (% ICV) values. Sixty-seven healthy older adults and 65 mild cognitive impairment patients underwent structural MRI and completed cognitive testing, including the Immediate and Delayed Memory indices from the Repeatable Battery for the Assessment of Neuropsychological Status. Results generally replicated previous relationships between key medial temporal lobe regions and memory test performance, though comparison of NQ regions revealed statistically different values that were biased toward one version or the other depending on the region. NQ2 hippocampal z-scores explained additional variance in memory performance relative to % ICV values. Findings indicate that NQ1/2 medial temporal lobe volumes, especially age- and sex-based z-scores, hold clinical value, though caution is warranted when directly comparing volumes across NQ versions.

Scanning-slit topography in patients with keratoconus.

PubMed

Módis, László; Németh, Gábor; Szalai, Eszter; Flaskó, Zsuzsa; Seitz, Berthold

2017-01-01

To evaluate the anterior and posterior corneal surfaces using scanning-slit topography and to determine the diagnostic ability of the measured corneal parameters in keratoconus. Orbscan II measurements were taken in 39 keratoconic corneas previously diagnosed by corneal topography and in 39 healthy eyes. The central minimum, maximum, and astigmatic simulated keratometry (K) and anterior axial power values were determined. Spherical and cylindrical mean power diopters were obtained at the central and at the steepest point of the cornea both on anterior and on posterior mean power maps. Pachymetry evaluations were taken at the center and paracentrally in the 3 mm zone from the center at a location of every 45 degrees. Receiver operating characteristic (ROC) analysis was used to determine the best cut-off values and to evaluate the utility of the measured parameters in identifying patients with keratoconus. The minimum, maximum and astigmatic simulated K readings were 44.80±3.06 D, 47.17±3.67 D and 2.42±1.84 D respectively in keratoconus patients and these values differed significantly ( P <0.0001 for all comparisons) from healthy subjects. For all pachymetry measurements and for anterior and posterior mean power values significant differences were found between the two groups. Moreover, anterior central cylindrical power had the best discrimination ability (area under the ROC curve=0.948). The results suggest that scanning-slit topography and pachymetry are accurate methods both for keratoconus screening and for confirmation of the diagnosis.

Spin Vector and Shape of (6070) Rheinland and Their Implications

NASA Astrophysics Data System (ADS)

Vokrouhlický, David; Ďurech, Josef; Polishook, David; Krugly, Yurij N.; Gaftonyuk, Ninel N.; Burkhonov, Otabek A.; Ehgamberdiev, Shukhrat A.; Karimov, Rivkat; Molotov, Igor E.; Pravec, Petr; Hornoch, Kamil; Kušnirák, Peter; Oey, Julian; Galád, Adrián; Žižka, Jindřich

2011-11-01

Main belt asteroids (6070) Rheinland and (54827) 2001 NQ8 belong to a small population of couples of bodies that reside in very similar heliocentric orbits. Vokrouhlický & Nesvorný promoted the term "asteroid pairs," pointing out their common origin within the past tens to hundreds of kyr. Previous attempts to reconstruct the initial configuration of Rheinland and 2001 NQ8 at the time of their separation have led to the prediction that Rheinland's rotation should be retrograde. Here, we report extensive photometric observations of this asteroid and use the light curve inversion technique to directly determine its rotation state and shape. We confirm the retrograde sense of rotation of Rheinland, with obliquity value constrained to be >=140°. The ecliptic longitude of the pole position is not well constrained as yet. The asymmetric behavior of Rheinland's light curve reflects a sharp, near-planar edge in our convex shape representation of this asteroid. Our calibrated observations in the red filter also allow us to determine HR = 13.68 ± 0.05 and G = 0.31 ± 0.05 values of the H-G system. With the characteristic color index V - R = 0.49 ± 0.05 for S-type asteroids, we thus obtain H = 14.17 ± 0.07 for the absolute magnitude of (6070) Rheinland. This is a significantly larger value than previously obtained from analysis of astrometric survey observations. We next use the obliquity constraint for Rheinland to eliminate some degree of uncertainty in the past propagation of its orbit. This is because the sign of the past secular change of its semimajor axis due to the Yarkovsky effect is now constrained. The determination of the rotation state of the secondary component, asteroid (54827) 2001 NQ8, is the key element in further constraining the age of the pair and its formation process.

Attenuation and source properties at the Coso Geothermal area, California

USGS Publications Warehouse

Hough, S.E.; Lees, J.M.; Monastero, F.

1999-01-01

We use a multiple-empirical Green's function method to determine source properties of small (M -0.4 to 1.3) earthquakes and P- and S-wave attenuation at the Coso Geothermal Field, California. Source properties of a previously identified set of clustered events from the Coso geothermal region are first analyzed using an empirical Green's function (EGF) method. Stress-drop values of at least 0.5-1 MPa are inferred for all of the events; in many cases, the corner frequency is outside the usable bandwidth, and the stress drop can only be constrained as being higher than 3 MPa. P- and S-wave stress-drop estimates are identical to the resolution limits of the data. These results are indistinguishable from numerous EGF studies of M 2-5 earthquakes, suggesting a similarity in rupture processes that extends to events that are both tiny and induced, providing further support for Byerlee's Law. Whole-path Q estimates for P and S waves are determined using the multiple-empirical Green's function (MEGF) method of Hough (1997), whereby spectra from clusters of colocated events at a given station are inverted for a single attenuation parameter, ??, with source parameters constrained from EGF analysis. The ?? estimates, which we infer to be resolved to within 0.01 sec or better, exhibit almost as much scatter as a function of hypocentral distance as do values from previous single-spectrum studies for which much higher uncertainties in individual ?? estimates are expected. The variability in ?? estimates determined here therefore suggests real lateral variability in Q structure. Although the ray-path coverage is too sparse to yield a complete three-dimensional attenuation tomographic image, we invert the inferred ?? value for three-dimensional structure using a damped least-squares method, and the results do reveal significant lateral variability in Q structure. The inferred attenuation variability corresponds to the heat-flow variations within the geothermal region. A central low-Q region corresponds well with the central high-heat flow region; additional detailed structure is also suggested.

Half-value-layer increase owing to tungsten buildup in the x-ray tube: fact or fiction.

PubMed

Stears, J G; Felmlee, J P; Gray, J E

1986-09-01

The half-value layer (HVL) of an x-ray beam is generally believed to increase with x-ray tube use. This increase in HVL has previously been attributed to the hardening of the x-ray beam as a result of a buildup of tungsten on the x-ray tube glass window. Radiographs and HVL measurements were obtained to determine the effect of tungsten deposited on the x-ray tube windows. This work, along with the HVL data from approximately 200 functioning x-ray tubes used for all applications that were monitored for more than 8 years, indicated there is no significant increase in HVL with diagnostic x-ray tube use.

Fracture toughness of CIP-HIP (cold isostatic pressed - hot isostatic pressed) beryllium at elevated temperatures. Final report, 13 May 1980-13 February 1981

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barker, L.M.; Jones, A.H.

1986-04-01

The fracture toughness of CIP-HIP (cold isostatic pressed-hot isostatic pressed) beryllium was determined using the short-bar fracture-toughness (K/sub IcSB/) method. The K/sub IcSB/ value measured was 10.96 MPa x the square root of m at room temperature. This falls well within the expected range of 9 to 12 MPa x the square root of m as observed from previous fracture toughness measurements of beryllium. Toughness increased rapidly between 400 F and 500 F reaching a value of 16.7 MPa x the square root of m at 500 F.

Theory of retrieving orientation-resolved molecular information using time-domain rotational coherence spectroscopy

NASA Astrophysics Data System (ADS)

Wang, Xu; Le, Anh-Thu; Zhou, Zhaoyan; Wei, Hui; Lin, C. D.

2017-08-01

We provide a unified theoretical framework for recently emerging experiments that retrieve fixed-in-space molecular information through time-domain rotational coherence spectroscopy. Unlike a previous approach by Makhija et al. (V. Makhija et al., arXiv:1611.06476), our method can be applied to the retrieval of both real-valued (e.g., ionization yield) and complex-valued (e.g., induced dipole moment) molecular response information. It is also a direct retrieval method without using iterations. We also demonstrate that experimental parameters, such as the fluence of the aligning laser pulse and the rotational temperature of the molecular ensemble, can be quite accurately determined using a statistical method.

Determining Hβ Color Indices for 23 δ Scuti Variable Stars

NASA Astrophysics Data System (ADS)

Bush, Tabitha C.; Hintz, E. G.; Shreeve, D. K.; Jorgenson, K.

2010-01-01

Color index is a fundamental characteristic in the study of δ Scuti variable stars. The then comprehensive catalog of δ Scutis compiled by Rodriguez et al. (Rodriguez, E. Lopez Gonzalez, M. J., & Lopez de Coca, P. 2000, A&AS, 144, 469) contains 636 δ Scuti stars and several characteristics of these stars, including Hβ color index. Of the 417 stars in this catalog brighter than 13th magnitude, about 20% of them are missing Hβ color index values. We present 23 of these previously unpublished values, calculated from a calibration relation using spectroscopic observations obtained at the Dominion Astrophysical Observatory of 167 δ Scuti stars north of -01 degrees declination and brighter than 13th magnitude.

Effect of adsorption on the surface tensions of solid-fluid interfaces.

PubMed

Ward, C A; Wu, Jiyu

2007-04-12

A method is proposed for determining the surface tensions of a solid in contact with either a liquid or a vapor. Only an equilibrium adsorption isotherm at the solid-vapor interface needs to be added to Gibbsian thermodynamics to obtain the expressions for the solid-vapor and the solid-liquid surface tensions, gamma[1](SV) and gamma[1](SL), respectively. An equilibrium adsorption isotherm relation is formulated that has the essential property of not predicting an infinite amount adsorbed when the pressure is equal to the saturation-vapor pressure. Five different solid-vapor systems from the literature are examined, and found to be well described by the new isotherm relation. The surface-tension expressions obtained from the isotherm relation are examined by determining the surface tension of the solid in the absence of adsorption, gamma[1](S0), a material property of a solid surface. The value of gamma[1](S0) can be determined by adsorbing different vapors on the same solid, determining the isotherm parameters in each case, and then from the expression for gamma[1](SV) taking the limit of the pressure vanishing to determine gamma[1](S0). From previously reported measurements of benzene and of n-hexane adsorbing on graphitized carbon, the same value of gamma[1](S0) is obtained.

Fine-particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models

NASA Astrophysics Data System (ADS)

Song, Shaojie; Gao, Meng; Xu, Weiqi; Shao, Jingyuan; Shi, Guoliang; Wang, Shuxiao; Wang, Yuxuan; Sun, Yele; McElroy, Michael B.

2018-05-01

pH is an important property of aerosol particles but is difficult to measure directly. Several studies have estimated the pH values for fine particles in northern China winter haze using thermodynamic models (i.e., E-AIM and ISORROPIA) and ambient measurements. The reported pH values differ widely, ranging from close to 0 (highly acidic) to as high as 7 (neutral). In order to understand the reason for this discrepancy, we calculated pH values using these models with different assumptions with regard to model inputs and particle phase states. We find that the large discrepancy is due primarily to differences in the model assumptions adopted in previous studies. Calculations using only aerosol-phase composition as inputs (i.e., reverse mode) are sensitive to the measurement errors of ionic species, and inferred pH values exhibit a bimodal distribution, with peaks between -2 and 2 and between 7 and 10, depending on whether anions or cations are in excess. Calculations using total (gas plus aerosol phase) measurements as inputs (i.e., forward mode) are affected much less by these measurement errors. In future studies, the reverse mode should be avoided whereas the forward mode should be used. Forward-mode calculations in this and previous studies collectively indicate a moderately acidic condition (pH from about 4 to about 5) for fine particles in northern China winter haze, indicating further that ammonia plays an important role in determining this property. The assumed particle phase state, either stable (solid plus liquid) or metastable (only liquid), does not significantly impact pH predictions. The unrealistic pH values of about 7 in a few previous studies (using the standard ISORROPIA model and stable state assumption) resulted from coding errors in the model, which have been identified and fixed in this study.

HEMOLYSIS AND HYPERBILIRUBINEMIA IN ABO BLOOD GROUP HETEROSPECIFIC NEONATES

PubMed Central

Kaplan, Michael; Hammerman, Cathy; Vreman, Hendrik J; Wong, Ronald J; Stevenson, David K

2010-01-01

Objective We quantified hemolysis and determined the incidence of hyperbilirubinemia in direct antiglobulin titer (DAT) positive, ABO heterospecific neonates and compared variables among O-A and O-B subgroups. Study design Plasma total bilirubin (PTB) was determined predischarge and more frequently if clinically warranted, in DAT positive, blood group A or B neonates of group O mothers. Heme catabolism (and therefore bilirubin production) was indexed by blood carboxyhemoglobin corrected for inspired carbon monoxide (COHbc). Hyperbilirubinemia was defined as any PTB concentration >95th percentile on the hour-of-life-specific bilirubin nomogram. Results Of 164 neonates, 111 were O-A and 53 O-B. Overall, 85 (51.8%) developed hyperbilirubinemia, which tended to be more prevalent in the O-B than O-A neonates (62.3% vs. 46.8% respectively, p=0.053). Importantly, more O-B than O-A newborns developed hyperbilirubinemia at <24 hours (93.9% vs. 48.1%, p<0.0001). COHbc values were globally higher than our previously published newborn values. Babies who developed hyperbilirubinemia had higher COHbc values than the already high values of those non-hyperbilirubinemic, and O-B newborns tended to have higher values than O-A counterparts. Conclusions DAT positive, ABO heterospecificity is associated with increased hemolysis and a high incidence of neonatal hyperbilirubinemia. O-B heterospecificity tends to confer even higher risk than O-A counterparts. PMID:20598320

Selection of Suitable DNA Extraction Methods for Genetically Modified Maize 3272, and Development and Evaluation of an Event-Specific Quantitative PCR Method for 3272.

PubMed

Takabatake, Reona; Masubuchi, Tomoko; Futo, Satoshi; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Teshima, Reiko; Kurashima, Takeyo; Mano, Junichi; Kitta, Kazumi

2016-01-01

A novel real-time PCR-based analytical method was developed for the event-specific quantification of a genetically modified (GM) maize, 3272. We first attempted to obtain genome DNA from this maize using a DNeasy Plant Maxi kit and a DNeasy Plant Mini kit, which have been widely utilized in our previous studies, but DNA extraction yields from 3272 were markedly lower than those from non-GM maize seeds. However, lowering of DNA extraction yields was not observed with GM quicker or Genomic-tip 20/G. We chose GM quicker for evaluation of the quantitative method. We prepared a standard plasmid for 3272 quantification. The conversion factor (Cf), which is required to calculate the amount of a genetically modified organism (GMO), was experimentally determined for two real-time PCR instruments, the Applied Biosystems 7900HT (the ABI 7900) and the Applied Biosystems 7500 (the ABI7500). The determined Cf values were 0.60 and 0.59 for the ABI 7900 and the ABI 7500, respectively. To evaluate the developed method, a blind test was conducted as part of an interlaboratory study. The trueness and precision were evaluated as the bias and reproducibility of the relative standard deviation (RSDr). The determined values were similar to those in our previous validation studies. The limit of quantitation for the method was estimated to be 0.5% or less, and we concluded that the developed method would be suitable and practical for detection and quantification of 3272.

Revised and extended analysis of the eighth spectrum of platinum (Pt VIII)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azarov, Vladimir I., E-mail: vlad_azarov@yahoo.com; Gayasov, Robert R.

2017-05-15

The spectrum of platinum was observed in the 300–2100 Å wavelength region. Grazing and normal incidence VUV spectrographs have been used to record the spectrum. The (5d{sup 3}+5d{sup 2}6s)−5d{sup 2}6p transition array of seven times ionized platinum, Pt VIII, has been investigated. The configurations 5d{sup 3} and 5d{sup 2}6p had been previously studied, and all levels of these configurations (19 and 45 levels, respectively) had been established. The previous analysis was based on 178 classified spectral lines. In the current analysis we have confirmed identification of all previously found levels and all but 10 previously assigned spectral lines, although we havemore » detected a large (up to 35 mÅ) systematic shift in wavelength measurements used in the previous analysis. Based on new wavelength measurements, we have corrected the 5d{sup 3} and 5d{sup 2}6p energy level values (by up to 55 cm{sup −1}) and established for the first time 14 out of 16 theoretically possible 5d{sup 2}6s levels in Pt VIII. The total list of identified lines (including 180 new lines) contains 349 entries. The orthogonal operators technique was used to calculate the level structure and transition probabilities. The energy parameters have been determined by the least squares fit to the observed levels. Calculated transition probability and energy values, as well as LS-compositions obtained from the fitted parameters are presented.« less

Research and development for a ground-based hydrogen-maser system

NASA Technical Reports Server (NTRS)

1972-01-01

The results of a joint experiment aimed primarily at the determination of the frequency of the H(1) hyperfine transition are reported. The transition frequency value for Cs-133 hyperfine transition is found. The result is the mean of two independent evaluations against the cesium reference, which differ by 0.002 Hz. The one-sigma uncertainty of the value nu sub H is also estimated to be 0.002 Hz. One evaluation is based on wall shift experiments at Harvard University; the other is a result of new wall shift measurement using many storage bulbs of different sizes at the National Bureau of Standards. The experimental procedures and the applied corrections are described. Results for the wall shift and for the frequency of hydrogen are compared with previously published values, and error limits of the experiments are discussed.

Correlations of the Specific Rates of Solvolysis of Aromatic Carbamoyl Chlorides, Chloroformates, Chlorothionoformates, and Chlorodithioformates Revisited

PubMed Central

Kevill, Dennis N.; Koyoshi, Fumie; D’Souza, Malcolm J.

2007-01-01

Additional specific rates of solvolysis are determined for phenyl chloroformate. These values are combined with literature values to give a total of 49 data points, which are used within simple and extended Grunwald-Winstein treatments. Literature values are also brought together to allow treatments in more solvents than previously for three N-aryl-N-methylcarbamoyl chlorides, phenyl chlorothionoformate, phenyl chlorodithioformate, and N,N-diphenylcarbamoyl chloride. For the last two listed, moderately strong evidence for a meaningful inclusion of a term governed by the aromatic ring parameter (I) was indicated. No evidence was found requiring inclusion of this parameter for ionization reactions with only one aromatic ring on the nitrogen of carbamoyl chlorides or for the solvolyses of the chloroformate or chlorothionoformate proceeding by an addition-elimination (association-dissociation) mechanism.

Stress concentration in a cylindrical shell containing a circular hole.

NASA Technical Reports Server (NTRS)

Adams, N. J. I.

1971-01-01

The state of stress in a cylindrical shell containing a circular cutout was determined for axial tension, torsion, and internal pressure loading. The solution was obtained for the shallow shell equations by a variational method. The results were expressed in terms of a nondimensional curvature parameter which was a function of shell radius, shell thickness, and hole radius. The function chosen for the solution was such that when the radius of the cylindrical shell approaches infinity, the flat-plate solution was obtained. The results are compared with solutions obtained by more rigorous analytical methods, and with some experimental results. For small values of the curvature parameter, the agreement is good. For higher values of the curvature parameter, the present solutions indicate a limiting value of stress concentration, which is in contrast to previous results.

Anodonta imbecillis copper sulfate reference toxicant test, Clinch River - Environmental Restoration Program (CR-ERP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simbeck, D.J.

1997-06-01

Reference toxicant testing using juvenile freshwater mussels was conducted as part of the CR-ERP biomonitoring study of Clinch River sediments to assess the sensitivity of test organisms and the overall performance of the test. Tests were conducted using moderately hard synthetic water spiked with known concentrations of copper as copper sulfate. Toxicity testing of copper sulfate reference toxicant was conducted from May 12-21, 1993. The organisms used for testing were juvenile fresh-water mussels (Anodonta imbecillis). Results from this test showed an LC{sub 50} value of 1.12 mg Cu/L which is lower than the value of 2.02 mg Cu/L obtained inmore » a previous test. Too few tests have been conducted with copper as the toxicant to determine a normal range of values.« less

Identification and modification of dominant noise sources in diesel engines

NASA Astrophysics Data System (ADS)

Hayward, Michael D.

Determination of dominant noise sources in diesel engines is an integral step in the creation of quiet engines, but is a process which can involve an extensive series of expensive, time-consuming fired and motored tests. The goal of this research is to determine dominant noise source characteristics of a diesel engine in the near and far-fields with data from fewer tests than is currently required. Pre-conditioning and use of numerically robust methods to solve a set of cross-spectral density equations results in accurate calculation of the transfer paths between the near- and far-field measurement points. Application of singular value decomposition to an input cross-spectral matrix determines the spectral characteristics of a set of independent virtual sources, that, when scaled and added, result in the input cross spectral matrix. Each virtual source power spectral density is a singular value resulting from the decomposition performed over a range of frequencies. The complex relationship between virtual and physical sources is estimated through determination of virtual source contributions to each input measurement power spectral density. The method is made more user-friendly through use of a percentage contribution color plotting technique, where different normalizations can be used to help determine the presence of sources and the strengths of their contributions. Convolution of input measurements with the estimated path impulse responses results in a set of far-field components, to which the same singular value contribution plotting technique can be applied, thus allowing dominant noise source characteristics in the far-field to also be examined. Application of the methods presented results in determination of the spectral characteristics of dominant noise sources both in the near- and far-fields from one fired test, which significantly reduces the need for extensive fired and motored testing. Finally, it is shown that the far-field noise time history of a physically altered engine can be simulated through modification of singular values and recalculation of transfer paths between input and output measurements of previously recorded data.

Revisiting the Phadia/EliA cut-off values for anticardiolipin and anti-β2-glycoprotein I antibodies: a systematic evaluation according to the guidelines.

PubMed

Bor, M V; Jacobsen, I-L Søtang; Gram, J B; Sidelmann, J J

2018-01-01

Background Phadia/EliA fluorescence enzyme immunoassays are widely used automated assays for anticardiolipin (aCL) and anti-β2-glycoprotein I (aβ2GPI) antibodies. To date, cut-off values for these assays have not been evaluated systematically and the evidence behind manufacturer's recommended cut-off values is not clear. Objective To determine Phadia/EliA cut-off values for antiphospholipid antibodies (aPL) according to the procedures suggested by guidelines. Methods A total of 266 blood donors (135 females and 131 males) were included. The pre-handling and analysis of the samples were performed according to the International Society on Thrombosis and Hemostasis (ISTH) guideline for solid phase aPL assays. Cut-off values and corresponding 90% confidence intervals (CI) for each antibody were established and outliers were handled according to the Clinical and Laboratory Standards Institute (CLSI) guideline for reference intervals. Samples from 377 consecutive patients, referred to our thrombophilia center with evidence of thrombosis or pregnancy morbidity were included for aPL testing. Results The in-house 99th (97.5th) percentile cut-off values were 11 (8.7), 12 (6.9) 8.5 (5.0) AU/mL for aβ2GPI IgG, IgM and IgA, and 21 (13) GPL-U/mL and 41 (25) MPL-U/mL for aCL IgG and IgM, respectively. The prevalence of positive results (%) defined by these cut-off values in patients with evidence of thrombosis or pregnancy morbidity was 9.5 (12.2), 1.6 (2.9), and 7.0 (9.9), and 0.8 (3.8) for aβ2GPI IgG, IgM, and aCL IgG and IgM respectively. The use of in-house 99th percentile cut-off values compared to the manufacturer suggested cut-off values resulted in 1 and 39 fewer samples for aβ2GPI and aCL to be classified as positive for aPL, respectively. Conclusions We present Phadia/EliA cut-off values with 90% CI for aPL determined systematically according to the ISTH and CLSI guidelines. These values are different from values previously determined, suggesting variation of aPLs in different populations. Our findings indicate the need for each laboratory to determine/validate assay specific cut-off values for aPL.

A computational study on the role of chiral N-oxides in enantioselective Pauson-Khand reactions.

PubMed

Fjermestad, Torstein; Pericàs, Miquel A; Maseras, Feliu

2011-08-29

Density functional calculations were carried out to ascertain the origin of enantioselectivity in the brucine N-oxide (BNO)-assisted enantioselective Pauson-Khand reaction (PKR) of norbornene with 2-methyl-3-butyn-2-ol. The computed ee value in acetone is 68 % (R), which compares well to the previously reported experimental value of 58 % (R). In DME the computed ee value of 76 % (R) is in excellent agreement with the experimentally determined value of 78 % (R). The mechanism of enantioselectivity consists of several steps. First, the dicobalt complex is activated by BNO with chirality transfer from enantiopure BNO to the dicobalt complex. Second, competition occurs between a racemization process and complexation with the olefin reagent, which leads to the products. The lower ee value in acetone is due to the lower energy barrier of the racemization process. Calculations show that replacement of BNO by a hypothetical more enantioselective chiral N-oxide will hardly increase the ee value beyond 90 %. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Establishing reference intervals for electrolytes in newborns and infants using direct ISE analyzer

PubMed Central

2013-01-01

Background To generate clinically applicable reference intervals (RIs) for commonly requested electrolytes in Ethiopian newborns and infants that can help in early detection, close monitoring and correction of electrolyte abnormalities. Cord blood (from newborns, n = 60) and venous blood samples (from infants, n = 57) were collected and analyzed using direct ISE analyzer, AVL (9181). MedCalc® software was applied to determine the robust upper and lower end points covering 95% of the reference values of each electrolyte with respective 90% CIs. Findings This is an extension report of our recent study; and hence is resulted from the same data source. The level of Na+ and K+ showed difference in newborns and infants even though combined RIs were suggested by the Haris and Boyd rule as 126–143 mmol/l and 4.0-7.9 mmol/l respectively. However, Cl- values failed to show such a difference and thus a combined RI was determined to be 100–111 mmol/l. Almost all maternal, neonatal and infantile factors were not able to affect the values of the electrolytes. Conclusion Combined RIs are suggested for the interpretation of electrolyte values in newborns and infants without taking the effect of maternal, neonatal and infantile factors into account. Since the RIs were different from previously reported values, it will be appropriate to apply such RIs for the interpretation of electrolyte values in Ethiopian pediatric population. PMID:23688032

Measuring changes in lipid and blood glucose values in the health and wellness program of Prudential Financial, Inc.

PubMed

Short, Meghan E; Goetzel, Ron Z; Young, Jared S; Kowlessar, Niranjana M; Liss-Levinson, Rivka C; Tabrizi, Maryam J; Roemer, Enid Chung; Sabatelli, Adriano A; Winick, Keith; Montes, Myrtho; Crighton, K Andrew

2010-08-01

To determine the effect of health promotion programs of Prudential Financial, Inc on biometric measures of blood lipids and glucose. Using actual biometric and self-reported measures of blood lipids and glucose values for the employees of Prudential Financial, Inc, we examined 1) the extent to which self-reported lipid and blood glucose values correlate to laboratory data, 2) whether self-reported and measured lipid values differ for physically active and sedentary employees, and 3) whether participation in a disease management program affects employees' lipid measures. We found significant differences in self-reported and measured total cholesterol and low-density lipoprotein values, although these differences and those for all lipid and blood glucose values were not clinically meaningful. Supporting previous clinical studies, high-density lipoprotein values were significantly higher for fitness center users compared with sedentary employees. Finally, disease management participants showed a significant reduction in total cholesterol and low-density lipoprotein during a 3-year period compared with nonparticipants. On average, the employees of Prudential Financial, Inc were aware of and accurately reported their lipid and blood glucose levels. Results from this study support the value of evaluating corporate health promotion programs, using measured biometric outcomes.

Catholic hospital services for vulnerable populations: are system values sufficient determinants?

PubMed

White, Kenneth R; Chou, Tiang-Hong; Dandi, Roberto

2010-01-01

Catholic hospitals and health systems comprise a substantial segment of nonprofit, mission-driven, health care services, with accountability to institutional pressures of the Roman Catholic Church as well as economic pressures for solvency. Values are the way in which the organization expresses its faith-based institutional identity, which may used to select services that represent those values. The purpose of this study was to identify whether Catholic health systems' explicit values of justice or compassion (and derivatives of those words, known to have similar meaning) were associated with a greater number of system member hospitals' services aimed at vulnerable populations. Using information from Web sites of 41 Catholic health systems in 2007 and data describing their 452 hospitals from the American Hospital Association Annual Survey, the relationship of health system values with hospital services for vulnerable populations was examined while controlling for organizational, market, and demand variables. Although Catholic hospitals as a whole are more likely to provide services to vulnerable populations than to other ownership types, the results show that among Catholic hospitals, values of justice or compassion are not associated with more services (defined in this study) that reflect those values. System hospitals likely to have more services that represent the values of justice and compassion are larger, have a higher Medicaid payer mix, are located in less dense urban areas, and are members of geographically dispersed systems. Hospitals select services that may represent symbolic system values, but community need and financial means are stronger determinants. To bolster community benefit to justify tax exempt status, Catholic hospitals and systems may benefit from further defining, analyzing, and reporting the impact of access to relatively unprofitable services for previously underserved vulnerable populations.

Determination of the Pressure Drag of Airfoils by Integration of Surface Pressures

NASA Technical Reports Server (NTRS)

Phillips, William H.

1990-01-01

A study was conducted of the causes of pressure drag of subsonic airfoils. In a previous paper by the author, the pressure drag is obtained by calculating the total drag from the momentum defect in the boundary layer at the trailing edge and subtracting the friction drag obtained from integration of surface friction along the chord. Herein, the pressure drag is obtained by integrating the streamwise components of surface pressure around the airfoil. Studies were made to verify the accuracy of the integration procedure. The values of pressure drag were much smaller than those obtained by the previous method. This lack of agreement is attributed to the difficulty of calculating boundary layer conditions in the vicinity of the trailing edge and to the extreme sensitivity of the circulation and lift to the trailing edge conditions. The results of these studies are compared with those of previous investigations.

Usefulness of a 50-meter round walking test for fall prediction in the elderly requiring long-term care

PubMed Central

Hachiya, Mizuki; Murata, Shin; Otao, Hiroshi; Ihara, Takehiko; Mizota, Katsuhiko; Asami, Toyoko

2015-01-01

[Purpose] This study aimed to verify the usefulness of a 50-m round walking test developed as an assessment method for walking ability in the elderly. [Subjects] The subjects were 166 elderly requiring long-term care individuals (mean age, 80.5 years). [Methods] In order to evaluate the factors that had affected falls in the subjects in the previous year, we performed the 50-m round walking test, functional reach test, one-leg standing test, and 5-m walking test and measured grip strength and quadriceps strength. [Results] The 50-m round walking test was selected as a variable indicating fall risk based on the results of multiple logistic regression analysis. The cutoff value of the 50-m round walking test for determining fall risk was 0.66 m/sec. The area under the receiver operating characteristic curve was 0.64. The sensitivity of the cutoff value was 65.7%, the specificity was 63.6%, the positive predictive value was 55.0%, the negative predictive value was 73.3%, and the accuracy was 64.5%. [Conclusion] These results suggest that the 50-m round walking test is a potentially useful parameter for the determination of fall risk in the elderly requiring long-term care. PMID:26834327

Inhibitory Effects of Amorphigenin on the Mitochondrial Complex I of Culex pipiens pallens Coquillett (Diptera: Culicidae)

PubMed Central

Ji, Mingshan; Liang, Yaping; Gu, Zumin; Li, Xiuwei

2015-01-01

Previous studies in our laboratory found that the extract from seeds of Amorpha fruticosa in the Leguminosae family had lethal effects against mosquito larvae, and an insecticidal compound amorphigenin was isolated. In this study, the inhibitory effects of amorphigenin against the mitochondrial complex I of Culex pipiens pallens (Diptera: Culicidae) were investigated and compared with that of rotenone. The results showed that amorphigenin and rotenone can decrease the mitochondrial complex I activity both in vivo and in vitro as the in vivo IC50 values (the inhibitor concentrations leading to 50% of the enzyme activity lost) were determined to be 2.4329 and 2.5232 μmol/L, respectively, while the in vitro IC50 values were 2.8592 and 3.1375 μmol/L, respectively. Both amorphigenin and rotenone were shown to be reversible and mixed-I type inhibitors of the mitochondrial complex I of Cx. pipiens pallens, indicating that amorphigenin and rotenone inhibited the enzyme activity not only by binding with the free enzyme but also with the enzyme-substrate complex, and the values of KI and KIS for amorphigenin were determined to be 20.58 and 87.55 μM, respectively, while the values for rotenone were 14.04 and 69.23 μM, respectively. PMID:26307964

Diagnostic value of nested-PCR for identification of Malassezia species in dandruff

NASA Astrophysics Data System (ADS)

Jusuf, N. K.; Nasution, T. A.; Ullyana, S.

2018-03-01

Dandruff or pityriasis simplex is a condition of abnormal occurrence of formation of yellowish white scales from the scalp. Many factors play a role in the pathogenesis of dandruff, i.e.colonization of Malassezia species. Examination of Malassezia species previously done by culture as the gold standard. However, there are various difficulties in doing the culture. Identification method with anested-polymerase chain reaction (nested-PCR) is expected to provide quickly and easily detected. This study aimedto determine the diagnostic value of nested-PCR in the identification of Malassezia species in dandruff. From 21 subjects, scales from the scalp were taken and sent to the laboratory for nested-PCR identification. Statistical analysis of diagnostic test carried out to determine sensitivity, specificity, positive predictive value, and negative predictive value. The results showed nested-PCR detected 10 sample (47.6%) positive for Malassezia species consist of M. sympodialis (23.8%); M. slooffiae (9.5%); M. furfur (4.8%); M. globosa and M. furfur (4.8%); and M. restricta and M. sympodialis (4.8%). Detection of Malassezia species by nested-PCR has 100% in sensitivity whereas the specificity was 55%. Nested-PCR test has high sensitivity. Therefore nested-PCR may be considered for a faster and simpler alternative examination in identification for Malassezia species in dandruff.

Usefulness of a 50-meter round walking test for fall prediction in the elderly requiring long-term care.

PubMed

Hachiya, Mizuki; Murata, Shin; Otao, Hiroshi; Ihara, Takehiko; Mizota, Katsuhiko; Asami, Toyoko

2015-12-01

[Purpose] This study aimed to verify the usefulness of a 50-m round walking test developed as an assessment method for walking ability in the elderly. [Subjects] The subjects were 166 elderly requiring long-term care individuals (mean age, 80.5 years). [Methods] In order to evaluate the factors that had affected falls in the subjects in the previous year, we performed the 50-m round walking test, functional reach test, one-leg standing test, and 5-m walking test and measured grip strength and quadriceps strength. [Results] The 50-m round walking test was selected as a variable indicating fall risk based on the results of multiple logistic regression analysis. The cutoff value of the 50-m round walking test for determining fall risk was 0.66 m/sec. The area under the receiver operating characteristic curve was 0.64. The sensitivity of the cutoff value was 65.7%, the specificity was 63.6%, the positive predictive value was 55.0%, the negative predictive value was 73.3%, and the accuracy was 64.5%. [Conclusion] These results suggest that the 50-m round walking test is a potentially useful parameter for the determination of fall risk in the elderly requiring long-term care.

FPGA Accelerated Discrete-SURF for Real-Time Homography Estimation

DTIC Science & Technology

2015-03-26

allows for the sum of a group of pixels to be found with only four memory accesses, and a single calculation...of pixels are retrieved from memory and their Hessian determinant values are compared. If the center pixel of the 3x3 block is greater than the other...process- ing on the FPGA[5][24][31]. Third, previous approaches rely heavily on external memory and other components external to the FPGA, while a logic

Department of Defense Annual Report on Sexual Assault in the Military, Fiscal Year 2014

DTIC Science & Technology

2015-04-22

focused on the following objectives: • Determine whether club culture promotes or resists adherence to Army and USMA values, and why. • Obtain... firing range. The Subject would tell certain female trainees to spread their legs, and he would use the metal detector to touch the females in their...after she "gave up" attempting to resist after repeatedly telling him to stop during the previous progression of sexual contacts. Sexual Assault

VUV spectroscopic study of the ? state of H2

NASA Astrophysics Data System (ADS)

Dickenson, G. D.; Ubachs, W.

2014-04-01

Spectral lines, probing rotational quantum states J‧ = 0, 1, 2 of the inner well vibrations (υ‧ ≤ 8) in the ? state of molecular hydrogen, were recorded in high resolution using a vacuum ultraviolet Fourier transform absorption spectrometer in the wavelength range 73-86 nm. Accurate line positions and predissociation widths are determined from a fit to the absorption spectra. Improved values for the line positions are obtained, while the predissociation widths agree well with previous investigations.

He-accreting carbon-oxygen white dwarfs and Type Ia supernovae

NASA Astrophysics Data System (ADS)

Wang, Bo; Podsiadlowski, Philipp; Han, Zhanwen

2017-12-01

He accretion on to carbon-oxygen white dwarfs (CO WDs) plays a fundamental role when studying the formation of Type Ia supernovae (SNe Ia). Employing the MESA stellar evolution code, we calculated the long-term evolution of He-accreting CO WDs. Previous studies usually supposed that a WD can grow in mass to the Chandrasekhar limit in the stable He burning region and finally produce an SN Ia. However, in this study, we find that off-centre carbon ignition occurs in the stable He burning region if the accretion rate is above a critical value (∼2.05 × 10-6 M⊙ yr-1), resulting in accretion-induced collapse rather than an SN Ia. If the accretion rate is below the critical value, explosive carbon ignition will eventually happen in the centre producing an SN Ia. Taking into account the possibility of off-centre carbon ignition, we have re-determined the initial parameter space that produces SNe Ia in the He star donor channel, one of the promising channels to produce SNe Ia in young populations. Since this parameter space is smaller than was found in the previous study of Wang et al. (2009), the SN Ia rates are also correspondingly smaller. We also determined the chemical abundance profile of the He-accreting WDs at the moment of explosive carbon ignition, which can be used as initial input for SN Ia explosion models.

Liquid-liquid microextraction in a multicommuted flow system for direct spectrophotometric determination of iodine value in biodiesel.

PubMed

Pereira, Andréia C; Rocha, Fábio R P

2014-06-04

A flow-based procedure was developed for the direct spectrophotometric determination of the iodine value (IV) in biodiesel. The procedure was based on the microextraction/reaction of unsaturated compounds with triiodide ions in an aqueous medium by inserting the reagent solution between the aliquots of biodiesel without any pretreatment. The interaction occurred through the biodiesel film formed on the inner walls of the hydrophobic tube used as the reactor and at the aqueous/biodiesel interfaces. The spectrophotometric detection was based on the discoloration of the I3(-) reagent in the aqueous phase by using a glass tube coupled to a fiber-optic spectrophotometer as the detection cell. Reference solutions were prepared by dilution of biodiesel samples with previously determined IV in hexane. The analytical response was linear for IV from 13 to 135 g I2/100 g with a detection limit of 5 g I2/100 g. A coefficient of variation of 1.7% (n=10) and a sampling rate of 108 determinations per hour were achieved by consuming 224 μL of the sample and 200 μg of I2 per determination. The slopes of analytical curves obtained with three different biodiesel samples were in agreement (variations in slopes lower than 3.1%), thus indicating an absence of any matrix effects. Results for biodiesel samples from different sources agreed with the volumetric official procedure at the 95% confidence level. The proposed procedure is therefore a simple, fast, and reliable alternative for estimating the iodine value of biodiesel. Copyright © 2014. Published by Elsevier B.V.

Tissue oxygen measurement system

NASA Technical Reports Server (NTRS)

Soller, Babs R. (Inventor)

2004-01-01

A device and method in accordance with the invention for determining the oxygen partial pressure (PO.sub.2) of a tissue by irradiating the tissue with optical radiation such that the light is emitted from the tissue, and by collecting the reflected or transmitted light from the tissue to form an optical spectrum. A spectral processor determines the PO.sub.2 level in tissue by processing this spectrum with a previously-constructed spectral calibration model. The tissue may, for example, be disposed underneath a covering tissue, such as skin, of a patient, and the tissue illuminated and light collected through the skin. Alternatively, direct tissue illumination and collection may be effected with a hand-held or endoscopic probe. A preferred system also determines pH from the same spectrum, and the processor may determine critical conditions and issue warnings based on parameter values.

The lepton+jets Selection and Determination of the Lepton Fake Rate with the Full RunIIb Data Set

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meister, Daniel

2013-01-01

This thesis presents the combined single top andmore » $$ t\\overline{ }\\ t $$ lepton+jets selection for the full RunIIb dataset of the DØ detector. The selection uses the newest soft- ware versions including all standard central object identifications and corrections and has various additions and improvements compared to the previous 7 . 3 fb - 1 $$ t\\overline{ }\\ t $$ selection and the previous single top selection in order to accommodate even more different analyses. The lepton fake rate $$\\epsilon_{\\rm QCD}$$ and the real lepton efficiency $$\\epsilon_{\\rm sig}$$ are estimated using the matrix method and different variations are considered in order to determine the systematic errors. The calculation has to be done for each run period and every set of analysis cuts separately. In addition the values for the exclusive jet bins and for the new single top analysis cuts have been derived and the thesis shows numerous control plots to demonstrate the excellent agreement between data and Monte Carlo.« less

Spallation studies in Estane

NASA Astrophysics Data System (ADS)

Johnson, J. N.; Dick, J. J.

2000-04-01

Data are presented for the spall fracture of Estane. Estane has been studied previously to determine its low-pressure Hugoniot properties and high-rate viscoelastic response [J.N. Johnson, J.J. Dick and R.S. Hixson, J. Appl. Phys. 84, 2520-2529, 1998]. These results are used in the current analysis of spall fracture data for this material. Calculations are carried out with the characteristics code CHARADE and the finite-difference code FIDO. Comparison of model calculations with experimental data show the onset of spall failure to occur when the longitudinal stress reaches approximately 130 MPa in tension. At this point complete material separation does not occur, but rather the tensile strength in the material falls to approximately one-half the value at onset, as determined by CHARADE calculations. Finite-difference calculations indicate that the standard void-growth model (used previously to describe spall in metals) gives a reasonable approximation to the dynamic failure process in Estane. [Research supported by the USDOE under contract W-7405-ENG-36

A test method for determining adhesion forces and Hamaker constants of cementitious materials using atomic force microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lomboy, Gilson; Sundararajan, Sriram, E-mail: srirams@iastate.edu; Wang Kejin

2011-11-15

A method for determining Hamaker constant of cementitious materials is presented. The method involved sample preparation, measurement of adhesion force between the tested material and a silicon nitride probe using atomic force microscopy in dry air and in water, and calculating the Hamaker constant using appropriate contact mechanics models. The work of adhesion and Hamaker constant were computed from the pull-off forces using the Johnson-Kendall-Roberts and Derjagin-Muller-Toropov models. Reference materials with known Hamaker constants (mica, silica, calcite) and commercially available cementitious materials (Portland cement (PC), ground granulated blast furnace slag (GGBFS)) were studied. The Hamaker constants of the reference materialsmore » obtained are consistent with those published by previous researchers. The results indicate that PC has a higher Hamaker constant than GGBFS. The Hamaker constant of PC in water is close to the previously predicted value C{sub 3}S, which is attributed to short hydration time ({<=} 45 min) used in this study.« less

Revised ages for tuffs of the Yellowstone Plateau volcanic field: Assignment of the Huckleberry Ridge Tuff to a new geomagnetic polarity event

USGS Publications Warehouse

Lanphere, M.A.; Champion, D.E.; Christiansen, R.L.; Izett, G.A.; Obradovich, J.D.

2002-01-01

40Ar/39Ar ages were determined on the three major ash-flow tuffs of the Yellowstone Plateau volcanic field in the region of Yellowstone National Park in order to improve the precision of previously determined ages. Total-fusion and incremental-heating ages of sanidine yielded the following mean ages: Huckleberry Ridge Tuff-2.059 ?? 0.004 Ma; Mesa Falls Tuff-1.285 ?? 0.004 Ma; and Lava Creek Tuff-0.639 ?? 0.002 Ma. The Huckleberry Ridge Tuff has a transitional magnetic direction and has previously been related to the Reunion Normal-Polarity Subchron. Dating of the Reunion event has been reviewed and its ages have been normalized to a common value for mineral standards. The age of the Huckleberry Ridge Tuff is significantly younger than lava flows of the Reunion event on Re??union Island, supporting other evidence for a normal-polarity event younger than the Reunion event.

Physiology driven adaptivity for the numerical solution of the bidomain equations.

PubMed

Whiteley, Jonathan P

2007-09-01

Previous work [Whiteley, J. P. IEEE Trans. Biomed. Eng. 53:2139-2147, 2006] derived a stable, semi-implicit numerical scheme for solving the bidomain equations. This scheme allows the timestep used when solving the bidomain equations numerically to be chosen by accuracy considerations rather than stability considerations. In this study we modify this scheme to allow an adaptive numerical solution in both time and space. The spatial mesh size is determined by the gradient of the transmembrane and extracellular potentials while the timestep is determined by the values of: (i) the fast sodium current; and (ii) the calcium release from junctional sarcoplasmic reticulum to myoplasm current. For two-dimensional simulations presented here, combining the numerical algorithm in the paper cited above with the adaptive algorithm presented here leads to an increase in computational efficiency by a factor of around 250 over previous work, together with significantly less computational memory being required. The speedup for three-dimensional simulations is likely to be more impressive.

Clinical verification of a theory for predicting side branch stenosis after main vessel stenting in coronary bifurcation lesions.

PubMed

Vassilev, Dobrin; Gil, Robert

2008-12-01

To verify in a clinical scenario a theory for predicting side branch (SB) stenosis after main vessel stent implantation in coronary bifurcation lesions. Many unresolved issues remain regarding SB compromise when the parent vessel is stented. Bifurcation lesions (all Medina types) were subjected to angiographic analysis to determine the angle, defined as alpha, between the axes of the parent vessel and the SB. Using the prediction that the percent diameter stenosis (%DS) is equal to the cosine of angle alpha and relating it to a formula to determine the minimal lumen diameter (MLD) led to the following equation: MLD = ds x (1 -cos alpha); ds refers to the diameter of the SB. The predicted and observed SB stenosis values following angiography were compared. Fifty-two patients with 57 lesions were included in the analysis. Patient demographics and characteristics were similar to those in previous studies. There was a high coefficient of determination between the predicted and observed values of %DS (r(2)= 0.82, P < 0.001) and MLD (r(2)= 0.86, P < 0.001). We determined a cutoff value of 70% for predicted %DS for SB closure. When using multivariate regression analysis, the only predictor of SB ostial stenosis after stenting was alpha angle, whereas the predictors of MLD included the angle alpha and the RVD of the SB. Our analysis shows that the most powerful independent predictor of SB compromise is a new variable angle alpha.

Plasma osmolality reference values in African grey parrots (Psittacus erithacus erithacus), Hispaniolan Amazon parrots (Amazona ventralis), and red-fronted macaws (Ara rubrogenys).

PubMed

Beaufrère, Hugues; Acierno, Mark; Mitchell, Mark; Guzman, David Sanchez-Migallon; Bryant, Heather; Tully, Thomas N

2011-06-01

Birds are routinely presented to veterinarians for dehydration. Success with these cases ultimately depends on providing replacement fluids and re-establishing fluid homeostasis. Few studies have been done to determine reference ranges for plasma osmolality in birds. The goals of this study were to determine reference values for plasma osmolality in 3 species of parrots and to provide recommendations on fluid selection for replacement therapy in these species. Blood samples were collected from 21 adult Hispaniolan Amazon parrots (Amazona ventralis), 21 Congo African grey parrots (Psittacus erithacus erithacus), and 9 red-fronted macaws (Ara rubrogenys), and were placed into lithium heparin containers. Plasma osmolality was measured in duplicate with a freezing point depression osmometer. Summary statistics were computed from the average values. Reference ranges, calculated by using the robust method, were 288-324, 308-345, and 223-369 mOsm/kg in African grey parrots, Hispaniolan Amazon parrots, and red-fronted macaws, respectively. The mean +/- SD values were 306 +/- 7, 327 +/- 7, and 304 +/- 18 mOsm/kg in African grey parrots, Hispaniolan Amazon parrots, and red-fronted macaws, respectively. Comparisons with osmolality values in mammals and values previously reported for psittacine bird species suggest that plasma osmolality is slightly higher in parrots than in mammals, species-specific differences exist, and differences between reported values occur. Overall, fluids with an osmolarity close to 300-320 mOsm/L, such as Normosol-R, Plasmalyte-R, Plasmalyte-A, and NaCl 0.9%, can be recommended in parrots for fluid replacement therapy when isotonic fluids are required.

Reference values for airway resistance in newborns, infants and preschoolers from a Latin American population.

PubMed

Gochicoa, Laura G; Thomé-Ortiz, Laura P; Furuya, María E Y; Canto, Raquel; Ruiz-García, Martha E; Zúñiga-Vázquez, Guillermo; Martínez-Ramírez, Filiberto; Vargas, Mario H

2012-05-01

Several studies have determined reference values for airway resistance measured by the interrupter technique (Rint) in paediatric populations, but only one has been done on Latin American children, and no studies have been performed on Mexican children. Moreover, these previous studies mostly included children aged 3 years and older; therefore, information regarding Rint reference values for newborns and infants is scarce. Rint measurements were performed on preschool children attending eight kindergartens (Group 1) and also on sedated newborns, infants and preschool children admitted to a tertiary-level paediatric hospital due to non-cardiopulmonary disorders (Group 2). In both groups, Rint values were inversely associated with age, weight and height, but the strongest association was with height. The linear regression equation for Group 1 (n = 209, height 86-129 cm) was Rint = 2.153 - 0.012 × height (cm) (standard deviation of residuals 0.181 kPa/L/s). The linear regression equation for Group 2 (n = 55, height 52-113 cm) was Rint = 4.575 - 0.035 × height (cm) (standard deviation of residuals 0.567 kPa/L/s). Girls tended to have slightly higher Rint values than boys, a difference that diminished with increasing height. In this study, Rint reference values applicable to Mexican children were determined, and these values are probably also applicable to other paediatric populations with similar Spanish-Amerindian ancestries. There was an inverse relationship between Rint and height, with relatively large between-subject variability. © 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology.

δ15N values of atmospheric N species simultaneously collected using sector-based samplers distant from sources - Isotopic inheritance and fractionation

NASA Astrophysics Data System (ADS)

Savard, Martine M.; Cole, Amanda; Smirnoff, Anna; Vet, Robert

2017-08-01

The nitrogen isotope ratios (δ15N) of atmospheric N species are commonly suggested as indicators of N emission sources. Therefore, numerous research studies have developed analytical methodologies and characterized primary (gases) and secondary emission products (mostly precipitation and aerosols) from various emitters. These previous studies have generally collected either reduced or oxidized N forms, and sampled them separately prior to determining their δ15N values. Distinctive isotopic signals have been reported for emissions from various sources, and seasonality of the δ15N values has been frequently attributed to shifts in relative contributions from sources with different isotopic signals. However, theoretical concepts suggest that temperature effects on isotopic fractionation may also affect the δ15N values of atmospheric reaction products. Here we use a sector-based multi-stage filter system to simultaneously collect seven reduced and oxidized N species downwind from five different source types in Alberta, Canada. We report δ15N values obtained with a state-of-the-art gold-furnace pre-concentrator online with an isotope ratio mass spectrometer (IRMS) to provide representative results even for oxidized-N forms. We find that equilibrium isotope effects and their temperature dependence play significant roles in determining the δ15N values of the secondary emission products. In the end, seasonal δ15N changes here are mainly caused by temperature effects on fractionation, and the δ15N values of only two N species from one source type can be retained as potential fingerprints of emissions.

Integration of social perceptions, behaviors, and economic valuations of groundwater quality as an ecosystem service following exurban development

NASA Astrophysics Data System (ADS)

Godsey, S.; Larson, D. M.; Ohr, C. A.; Kobs-Nawotniak, S. E.; Lohse, K. A.; Lybecker, D.; Hale, R. L.; Stoutenborough, J.

2015-12-01

Millions of people rely on groundwater as a key, provisioning ecosystem service (ES). Our previous data suggested that drinking water nitrate concentrations and exurban development have significantly increased in the last three decades in Pocatello, Idaho, USA. Increased nitrate can lead to changes in ES and human values (such as water quality, people's knowledge, and housing values). We predicted people who tested their water quality would be aware of nitrate contamination and its potential to affect their housing prices, and they would choose to invest in home drinking water treatment systems. To test these hypotheses, we measured nitrate concentrations in hundreds of drinking water wells in years 1985, 1994, 2004, and 2015. We conducted a randomized public survey to determine the degrees to which: (1) people tested their private well water for nitrate and (2) were concerned about health issues related to contamination; (3) how important water quality is for determining local property values; and (4) if people treat their drinking water. We then developed a biophysical model to understand how exurban growth, local geology, and time influenced groundwater nitrate. Finally, we applied an economic, hedonic model to determine if groundwater nitrate concentrations negatively correlated to property values. Aquifer boundaries, slope, rock and soil type were significant predictors of nitrate (ordinary least squares, α <0.05). The hedonic model suggested that although nitrate and local housing values were spatially heterogeneous and increasing through time, exurban growth and nitrate alone were not strong predictors of water quality or property values. We also present an integrated biophysical, economic, and social model to better understand people's perceptions and behaviors of local nitrate pollution. Interdisciplinary ES and valuation may require multiple data types and integrated models to understand how ES and human values are influenced by exurban growth.

Potassium Isotopic Compositions of NIST Potassium Standards and 40Ar/39Ar Mineral Standards

NASA Technical Reports Server (NTRS)

Morgan, Leah; Tappa, Mike; Ellam, Rob; Mark, Darren; Higgins, John; Simon, Justin I.

2013-01-01

Knowledge of the isotopic ratios of standards, spikes, and reference materials is fundamental to the accuracy of many geochronological methods. For example, the 238U/235U ratio relevant to U-Pb geochronology was recently re-determined [1] and shown to differ significantly from the previously accepted value employed during age determinations. These underlying values are fundamental to accurate age calculations in many isotopic systems, and uncertainty in these values can represent a significant (and often unrecognized) portion of the uncertainty budget for determined ages. The potassium isotopic composition of mineral standards, or neutron flux monitors, is a critical, but often overlooked component in the calculation of K-Ar and 40Ar/39Ar ages. It is currently assumed that all terrestrial materials have abundances indistinguishable from that of NIST SRM 985 [2]; this is apparently a reasonable assumption at the 0.25per mille level (1s) [3]. The 40Ar/39Ar method further relies on the assumption that standards and samples (including primary and secondary standards) have indistinguishable 40K/39K values. We will present data establishing the potassium isotopic compositions of NIST isotopic K SRM 985, elemental K SRM 999b, and 40Ar/39Ar biotite mineral standard GA1550 (sample MD-2). Stable isotopic compositions (41K/39K) were measured by the peak shoulder method with high resolution MC-ICP-MS (Thermo Scientific NEPTUNE Plus), using the accepted value of NIST isotopic SRM 985 [2] for fractionation [4] corrections [5]. 40K abundances were measured by TIMS (Thermo Scientific TRITON), using 41K/39K values from ICP-MS measurements (or, for SRM 985, values from [2]) for internal fractionation corrections. Collectively these data represent an important step towards a metrologically traceable calibration of 40K concentrations in primary 40Ar/39Ar mineral standards and improve uncertainties by ca. an order of magnitude in the potassium isotopic compositions of standards.

The Role of Anthropogenic Activity and Climate on δ15N Values of Cave Bat Guano

NASA Astrophysics Data System (ADS)

Cleary, D. M.; Onac, B. P.; Forray, F. L.; Wynn, J. G.

2016-12-01

Interest in the use of bat guano, a paleoclimate and paleoenvironmental resource, has rapidly increased over the past decade. However, to this point the utility of the δ15N values of guano as a potential proxy remains poorly understood. In contrast to the preservation of the original carbon isotopic composition of guano, δ15N values have the potential to be altered as a result of processes of nitrogen (N) cycling such as denitrification. However, the probability of N loss is relatively diminished in younger guano. Here we present a 1.5 m guano core from Zidită Cave in western Romania that began accumulating at ca. 913 ± 30 yr BP. To determine the utility of N isotopes in guano studies, the δ15N time-series was compared to δ13C time series and pollen records of the same core to determine if the environmental impact (pollen) or water availability (δ13C values) has an effect on N cycling. Unlike to previous guano studies, the N content in the core is nearly constant (%N > 9 %) for over 1 m of the core, indicating limited diagenesis. Although major changes in anthropogenic activities may have influenced some δ15N variation, some inconsistencies suggest this is not the primary controller. However, the correlation between δ15N and δ13C values (p < 0.01) in this C3-plant dominated ecosystem has been interpreted to reflect variation driven largely by water availability. Wetter periods indicated by lower δ13C values correspond with higher δ15N values of guano. These results indicate that when the area surrounding the Zidită Cave receives an increase in rainfall the N-cycle becomes more open with a decreased rate of denitrification or other processes that accumulate 15N in the soil reservoir. A 10-year instrumental precipitation dataset agrees with the relationship found between δ13C and δ15N time series. These results suggest that guano δ15N values from Zidită Cave are a suitable proxy record of climate for this type of system, but we emphasize that this coupling of processes may not be universal. Over the past 60 years the δ15N values have decreased by 5.5 ‰, indicating that the N-cycle has been approaching a more conservative state in response to drier conditions. From this study it is clear that the potential utility of δ15N of guano (climate and state of the N-cycle) may have previously been overlooked.

Development of an Indirect ELISA Based on a Recombinant Chimeric Protein for the Detection of Antibodies against Bovine Babesiosis

PubMed Central

Jaramillo Ortiz, José Manuel; Montenegro, Valeria Noely; de la Fournière, Sofía Ana María; Sarmiento, Néstor Fabián; Farber, Marisa Diana; Wilkowsky, Silvina Elizabeth

2018-01-01

The current method for Babesia spp. serodiagnosis based on a crude merozoite antigen is a complex and time-consuming procedure. An indirect enzyme-linked immunosorbent assay (iELISA) based on a recombinant multi-antigen of Babesia bovis (rMABbO) was developed for detection of antibodies in bovines suspected of infection with this parasite. The multi-antigen comprises gene fragments of three previously characterized B. bovis antigens: MSA-2c, RAP-1 and the Heat Shock protein 20 that are well-conserved among geographically distant strains. The cutoff value for the new rMABbo-iELISA was determined using 75 known—positive and 300 known—negative bovine sera previously tested for antibodies to B. bovis by the gold-standard ELISA which uses a merozoite lysate. A cutoff value of ≥35% was determined in these samples by receiver operator characteristic (ROC) curve analysis, showing a sensitivity of 95.9% and a specificity of 94.3%. The rMABbo-iELISA was further tested in a blind trial using an additional set of 263 field bovine sera from enzootic and tick-free regions of Argentina. Results showed a good agreement with the gold standard test with a Cohen’s kappa value of 0.76. Finally, the prevalence of bovine babesiosis in different tick enzootic regions of Argentina was analyzed where seropositivity values among 68–80% were obtained. A certain level of cross reaction was observed when samples from B. bigemina infected cattle were analyzed with the new test, which can be attributed to shared epitopes between 2 of the 3 antigens. This new rMABbo-iELISA could be considered a simpler alternative to detect anti Babesia spp. antibodies and appears to be well suited to perform epidemiological surveys at the herd level in regions where ticks are present. PMID:29360801

Development of an Indirect ELISA Based on a Recombinant Chimeric Protein for the Detection of Antibodies against Bovine Babesiosis.

PubMed

Jaramillo Ortiz, José Manuel; Montenegro, Valeria Noely; de la Fournière, Sofía Ana María; Sarmiento, Néstor Fabián; Farber, Marisa Diana; Wilkowsky, Silvina Elizabeth

2018-01-23

The current method for Babesia spp. serodiagnosis based on a crude merozoite antigen is a complex and time-consuming procedure. An indirect enzyme-linked immunosorbent assay (iELISA) based on a recombinant multi-antigen of Babesia bovis (rMABbO) was developed for detection of antibodies in bovines suspected of infection with this parasite. The multi-antigen comprises gene fragments of three previously characterized B. bovis antigens: MSA-2c, RAP-1 and the Heat Shock protein 20 that are well-conserved among geographically distant strains. The cutoff value for the new rMABbo-iELISA was determined using 75 known-positive and 300 known-negative bovine sera previously tested for antibodies to B. bovis by the gold-standard ELISA which uses a merozoite lysate. A cutoff value of ≥35% was determined in these samples by receiver operator characteristic (ROC) curve analysis, showing a sensitivity of 95.9% and a specificity of 94.3%. The rMABbo-iELISA was further tested in a blind trial using an additional set of 263 field bovine sera from enzootic and tick-free regions of Argentina. Results showed a good agreement with the gold standard test with a Cohen's kappa value of 0.76. Finally, the prevalence of bovine babesiosis in different tick enzootic regions of Argentina was analyzed where seropositivity values among 68-80% were obtained. A certain level of cross reaction was observed when samples from B. bigemina infected cattle were analyzed with the new test, which can be attributed to shared epitopes between 2 of the 3 antigens. This new rMABbo-iELISA could be considered a simpler alternative to detect anti Babesia spp. antibodies and appears to be well suited to perform epidemiological surveys at the herd level in regions where ticks are present.

Kinetic measurement of 2-aminopurine X cytosine and 2-aminopurine X thymine base pairs as a test of DNA polymerase fidelity mechanisms.

PubMed Central

Watanabe, S M; Goodman, M F

1982-01-01

Enzyme kinetic measurements are presented showing that Km rather than maximum velocity (Vmax) discrimination governs the frequency of forming 2-aminopurine X cytosine base mispairs by DNA polymerase alpha. An in vitro system is used in which incorporation of dTMP or dCMP occurs opposite a template 2-aminopurine, and values for Km and Vmax are obtained. Results from a previous study in which dTTP and dCTP were competing simultaneously for insertion opposite 2-aminopurine indicated that dTMP is inserted 22 times more frequently than dCMP. We now report that the ratio of Km values KCm/KTm = 25 +/- 6, which agrees quantitatively with the dTMP/dCMP incorporation ratio obtained previously. We also report that VCmax is indistinguishable from VTmax. These Km and Vmax data are consistent with predictions from a model, the Km discrimination model, in which replication fidelity is determined by free energy differences between matched and mismatched base pairs. Central to this model is the prediction that the ratio of Km values for insertion of correct and incorrect nucleotides specifies the insertion fidelity, and the maximum velocities of insertion are the same for both nucleotides. PMID:6959128

Modeling subharmonic response from contrast microbubbles as a function of ambient static pressure

PubMed Central

Katiyar, Amit; Sarkar, Kausik; Forsberg, Flemming

2011-01-01

Variation of subharmonic response from contrast microbubbles with ambient pressure is numerically investigated for non-invasive monitoring of organ-level blood pressure. Previously, several contrast microbubbles both in vitro and in vivo registered approximately linear (5–15 dB) subharmonic response reduction with 188 mm Hg change in ambient pressure. In contrast, simulated subharmonic response from a single microbubble is seen here to either increase or decrease with ambient pressure. This is shown using the code BUBBLESIM for encapsulated microbubbles, and then the underlying dynamics is investigated using a free bubble model. The ratio of the excitation frequency to the natural frequency of the bubble is the determining parameter—increasing ambient pressure increases natural frequency thereby changing this ratio. For frequency ratio below a lower critical value, increasing ambient pressure monotonically decreases subharmonic response. Above an upper critical value of the same ratio, increasing ambient pressure increases subharmonic response; in between, the subharmonic variation is non-monotonic. The precise values of frequency ratio for these three different trends depend on bubble radius and excitation amplitude. The modeled increase or decrease of subharmonic with ambient pressure, when one happens, is approximately linear only for certain range of excitation levels. Possible reasons for discrepancies between model and previous experiments are discussed. PMID:21476688

Gas-Phase Lithium Cation Basicity: Revisiting the High Basicity Range by Experiment and Theory

NASA Astrophysics Data System (ADS)

Mayeux, Charly; Burk, Peeter; Gal, Jean-Francois; Kaljurand, Ivari; Koppel, Ilmar; Leito, Ivo; Sikk, Lauri

2014-09-01

According to high level calculations, the upper part of the previously published FT-ICR lithium cation basicity (LiCB at 373 K) scale appeared to be biased by a systematic downward shift. The purpose of this work was to determine the source of this systematic difference. New experimental LiCB values at 373 K have been measured for 31 ligands by proton-transfer equilibrium techniques, ranging from tetrahydrofuran (137.2 kJ mol-1) to 1,2-dimethoxyethane (202.7 kJ mol-1). The relative basicities (ΔLiCB) were included in a single self-consistent ladder anchored to the absolute LiCB value of pyridine (146.7 kJ mol-1). This new LiCB scale exhibits a good agreement with theoretical values obtained at G2(MP2) level. By means of kinetic modeling, it was also shown that equilibrium measurements can be performed in spite of the formation of Li+ bound dimers. The key feature for achieving accurate equilibrium measurements is the ion trapping time. The potential causes of discrepancies between the new data and previous experimental measurements were analyzed. It was concluded that the disagreement essentially finds its origin in the estimation of temperature and the calibration of Cook's kinetic method.

Computer-aided interpretation approach for optical tomographic images

NASA Astrophysics Data System (ADS)

Klose, Christian D.; Klose, Alexander D.; Netz, Uwe J.; Scheel, Alexander K.; Beuthan, Jürgen; Hielscher, Andreas H.

2010-11-01

A computer-aided interpretation approach is proposed to detect rheumatic arthritis (RA) in human finger joints using optical tomographic images. The image interpretation method employs a classification algorithm that makes use of a so-called self-organizing mapping scheme to classify fingers as either affected or unaffected by RA. Unlike in previous studies, this allows for combining multiple image features, such as minimum and maximum values of the absorption coefficient for identifying affected and not affected joints. Classification performances obtained by the proposed method were evaluated in terms of sensitivity, specificity, Youden index, and mutual information. Different methods (i.e., clinical diagnostics, ultrasound imaging, magnet resonance imaging, and inspection of optical tomographic images), were used to produce ground truth benchmarks to determine the performance of image interpretations. Using data from 100 finger joints, findings suggest that some parameter combinations lead to higher sensitivities, while others to higher specificities when compared to single parameter classifications employed in previous studies. Maximum performances are reached when combining the minimum/maximum ratio of the absorption coefficient and image variance. In this case, sensitivities and specificities over 0.9 can be achieved. These values are much higher than values obtained when only single parameter classifications were used, where sensitivities and specificities remained well below 0.8.

(210)Polonium and (210)lead content of marine birds from Southeastern Brazil.

PubMed

Godoy, José Marcus; Siciliano, Salvatore; de Carvalho, Zenildo Lara; Tavares, Davi C; de Moura, Jaílson Fulgencio; Godoy, Maria Luiza D P

2014-09-01

In this study, we report the (210)Po and (210)Pb concentrations of bone, muscle and liver samples that were obtained from twelve different marine bird species stranded on beaches in the central-north region of Rio de Janeiro State. Both radionuclides were highly concentrated in the liver samples; however, the lowest mean (210)Po/(210)Pb activity ratio (1.3) was observed in bones compared with liver and muscle (16.8 and 13.8, respectively). Among the species that were studied, Fregata magnificens, with a diet based exclusively on fish, had the lowest (210)Pb and (210)Po concentrations and the lowest (210)Po/(210)Pb activity ratio. The (210)Po concentrations in Puffinus spp. liver samples followed a log-normal distribution, with a geometric mean of 300 Bq kg(-1)wet weight. Only two references pertaining to (210)Po in marine birds were found in a Web of Science search of the literature, and each study reported a different concentration value. The values determined in this experiment are consistent with those in one of the previous studies, which also included one of the species studied in this work. No values for (210)Pb in marine birds have been published previously. Copyright © 2014 Elsevier Ltd. All rights reserved.

What determines patient preferences for treating low risk basal cell carcinoma when comparing surgery vs imiquimod? A discrete choice experiment survey from the SINS trial.

PubMed

Tinelli, Michela; Ozolins, Mara; Bath-Hextall, Fiona; Williams, Hywel C

2012-10-04

The SINS trial (Controlled Clinical Trials ISRCTN48755084; Eudract No. 2004-004506-24) is a randomised controlled trial evaluating long term success of excisional surgery vs. imiquimod 5% cream for low risk nodular and superficial basal cell carcinoma (BCC). The trial included a discrete choice experiment questionnaire to explore patient preferences of a cream versus surgery for the treatment of their skin cancer. The self-completed questionnaire was administered at baseline to 183 participants, measuring patients' strength of preferences when choosing either alternative 'surgery' or 'imiquimod cream' instead of a fixed 'current situation' option (of surgical excision as standard practice in UK). The treatments were described according to: cost, chance of complete clearance, side effects and appearance. Participants had to choose between various scenarios. Analysis was performed using a mixed logit model, which took into account the impact of previous BCC treatment and sample preference variability. The analysis showed that respondents preferred 'imiquimod cream' to their 'current situation' or 'surgery', regardless of previous experience of BCC symptoms and treatment. Respondents were more likely to be worried about their cosmetic outcomes and side effects they might experience over and above their chance of clearance and cost. Those with no experience of surgery (compared with experience) valued more the choice of 'imiquimod cream' (£1013 vs £781). All treatment characteristics were significant determinants of treatment choice, and there was significant variability in the population preferences for all of them. Patients with BCC valued more 'imiquimod cream' than alternative 'surgery' options, and all treatment characteristics were important for their choice of care. Understanding how people with a BCC value alternative interventions may better inform the development of health care interventions.

Nanostructural control of the release of macromolecules from silica sol–gels

PubMed Central

Radin, Shula; Bhattacharyya, Sanjib; Ducheyne, Paul

2013-01-01

The therapeutic use of biological molecules such as growth factors and monoclonal antibodies is challenging in view of their limited half-life in vivo. This has elicited the interest in delivery materials that can protect these molecules until released over extended periods of time. Although previous studies have shown controlled release of biologically functional BMP-2 and TGF-β from silica sol–gels, more versatile release conditions are desirable. This study focuses on the relationship between room temperature processed silica sol–gel synthesis conditions and the nanopore size and size distribution of the sol–gels. Furthermore, the effect on release of large molecules with a size up to 70 kDa is determined. Dextran, a hydrophilic polysaccharide, was selected as a large model molecule at molecular sizes of 10, 40 and 70 kDa, as it enabled us to determine a size effect uniquely without possible confounding chemical effects arising from the various molecules used. Previously, acid catalysis was performed at a pH value of 1.8 below the isoelectric point of silica. Herein the silica synthesis was pursued using acid catalysis at either pH 1.8 or 3.05 first, followed by catalysis at higher values by adding base. This results in a mesoporous structure with an abundance of pores around 3.5 nm. The data show that all molecular sizes can be released in a controlled manner. The data also reveal a unique in vivo approach to enable release of large biological molecules: the use more labile sol–gel structures by acid catalyzing above the pH value of the isoelectric point of silica; upon immersion in a physiological fluid the pores expand to reach an average size of 3.5 nm, thereby facilitating molecular out-diffusion. PMID:23643607

Viscous flux flow velocity and stress distribution in the Kim model of a long rectangular slab superconductor

NASA Astrophysics Data System (ADS)

Yang, Yong; Chai, Xueguang

2018-05-01

When a bulk superconductor endures the magnetization process, enormous mechanical stresses are imposed on the bulk, which often leads to cracking. In the present work, we aim to resolve the viscous flux flow velocity υ 0/w, i.e. υ 0 (because w is a constant) and the stress distribution in a long rectangular slab superconductor for the decreasing external magnetic field (B a ) after zero-field cooling (ZFC) and field cooling (FC) using the Kim model and viscous flux flow equation simultaneously. The viscous flux flow velocity υ 0/w and the magnetic field B* at which the body forces point away in all of the slab volumes during B a reduction, are determined by both B a and the decreasing rate (db a /dt) of the external magnetic field normalized by the full penetration field B p . In previous studies, υ 0/w obtained by the Bean model with viscous flux flow is only determined by db a /dt, and the field B* that is derived only from the Kim model is a positive constant when the maximum external magnetic field is chosen. This means that the findings in this paper have more physical contents than the previous results. The field B* < 0 can be kept for any value of B a when the rate db a /dt is greater than a certain value. There is an extreme value for any curve of maximum stress changing with decreasing field B a after ZFC if B* ≤ 0. The effect of db a /dt on the stress is significant in the cases of both ZFC and FC.

In vitro assessment of competitive and time-dependent inhibition of the nevirapine metabolism by nortriptyline in rats.

PubMed

Usach, Iris; Ferrer, José-Maria; Peris, José-Esteban

2018-04-17

Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor of human immunodeficiency virus type 1 (HIV-1) widely used as a component of High Active Antiretroviral Therapy (HAART) since it is inexpensive, readily absorbed after oral administration and non-teratogenic. In the present work, the mechanism of a previously described pharmacokinetic interaction between NVP and the antidepressant drug nortriptyline (NT) was studied using rat hepatic microsomes. The obtained results showed a competitive inhibition of the NVP metabolism by NT. The three main NVP metabolites (2-OH-NVP, 3-OH-NVP and 12-OH-NVP) where competitively inhibited with similar inhibitory constant values (K i  = 4.01, 3.97 and 4.40 μM, respectively). Time-dependent inhibition of the NVP metabolism was also detected, with a 2.5-fold reduction in the IC 50 values of NT for 2-, 3-, and 12-OH-NVP formation when NT was preincubated with the microsomal suspension in the presence of an NADPH-generating system. A concentration-dependent inhibition of the formation of NVP metabolites by the main NT metabolite (10-OH-NT) was also observed, however, the inhibitory potency of 10-OH-NT was much lower than that of the parent drug. The apparent hepatic intrinsic clearance of NVP determined in these in vitro experiments was used to predict the in vivo clearance of NVP using the "well-stirred" and the "parallel-tube" models, resulting in values close to those previously observed in vivo clearance. Finally, a good prediction of the increase in the plasma concentrations of NVP when co-administered with NT was obtained employing the inhibitory constant of NT determined in vitro and the estimated plasma concentration of NT entering the liver. Copyright © 2018. Published by Elsevier Inc.

Style-by-style analysis of two sporadic self-compatible Solanum chacoense lines supports a primary role for S-RNases in determining pollen rejection thresholds.

PubMed

Qin, Xike; Liu, Bolin; Soulard, Jonathan; Morse, David; Cappadocia, Mario

2006-01-01

A method for the quantification of S-RNase levels in single styles of self-incompatible Solanum chacoense was developed and applied toward an experimental determination of the S-RNase threshold required for pollen rejection. It was found that, when single style values are averaged, accumulated levels of the S(11)- and S(12)-RNases can differ up to 10-fold within a genotype, while accumulated levels of the S(12)-RNase can differ by over 3-fold when different genotypes are compared. Surprisingly, the amount of S(12)-RNase accumulated in different styles of the same plant can differ by over 20-fold. A low level of 160 ng S-RNase in individual styles of fully incompatible plants, and a high value of 68 ng in a sporadic self-compatible (SSC) line during a bout of complete compatibility was measured, suggesting that these values bracket the threshold level of S-RNase needed for pollen rejection. Remarkably, correlations of S-RNase values to average fruit sets in different plant lines displaying sporadic self-compatibility (SSC) to different extents as well as to fruit set in immature flowers, are all consistent with a threshold value of 80 ng S(12)-RNase. Taken together, these results suggest that S-RNase levels alone are the principal determinant of the incompatibility phenotype. Interestingly, while the S-RNase threshold required for rejection of S(12)-pollen from a given genetic background is the same in styles of different genetic backgrounds, it is different when pollen donors of different genetic backgrounds are used. These results reveal a previously unsuspected level of complexity in the incompatibility reaction.

Group Additivity Determination for Oxygenates, Oxonium Ions, and Oxygen-Containing Carbenium Ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dellon, Lauren D.; Sung, Chun-Yi; Robichaud, David J.

Bio-oil produced from biomass fast pyrolysis often requires catalytic upgrading to remove oxygen and acidic species over zeolite catalysts. The elementary reactions in the mechanism for this process involve carbenium and oxonium ions. In order to develop a detailed kinetic model for the catalytic upgrading of biomass, rate constants are required for these elementary reactions. The parameters in the Arrhenius equation can be related to thermodynamic properties through structure-reactivity relationships, such as the Evans-Polanyi relationship. For this relationship, enthalpies of formation of each species are required, which can be reasonably estimated using group additivity. However, the literature previously lacked groupmore » additivity values for oxygenates, oxonium ions, and oxygen-containing carbenium ions. In this work, 71 group additivity values for these types of groups were regressed, 65 of which had not been reported previously and six of which were newly estimated based on regression in the context of the 65 new groups. Heats of formation based on atomization enthalpy calculations for a set of reference molecules and isodesmic reactions for a small set of larger species for which experimental data was available were used to demonstrate the accuracy of the Gaussian-4 quantum mechanical method in estimating enthalpies of formation for species involving the moieties of interest. Isodesmic reactions for a total of 195 species were constructed from the reference molecules to calculate enthalpies of formation that were used to regress the group additivity values. The results showed an average deviation of 1.95 kcal/mol between the values calculated from Gaussian-4 and isodesmic reactions versus those calculated from the group additivity values that were newly regressed. Importantly, the new groups enhance the database for group additivity values, especially those involving oxonium ions.« less

Determination of hydrologic properties needed to calculate average linear velocity and travel time of ground water in the principal aquifer underlying the southeastern part of Salt Lake Valley, Utah

USGS Publications Warehouse

Freethey, G.W.; Spangler, L.E.; Monheiser, W.J.

1994-01-01

A 48-square-mile area in the southeastern part of the Salt Lake Valley, Utah, was studied to determine if generalized information obtained from geologic maps, water-level maps, and drillers' logs could be used to estimate hydraulic conduc- tivity, porosity, and slope of the potentiometric surface: the three properties needed to calculate average linear velocity of ground water. Estimated values of these properties could be used by water- management and regulatory agencies to compute values of average linear velocity, which could be further used to estimate travel time of ground water along selected flow lines, and thus to determine wellhead protection areas around public- supply wells. The methods used to estimate the three properties are based on assumptions about the drillers' descriptions, the depositional history of the sediments, and the boundary con- ditions of the hydrologic system. These assump- tions were based on geologic and hydrologic infor- mation determined from previous investigations. The reliability of the estimated values for hydro- logic properties and average linear velocity depends on the accuracy of these assumptions. Hydraulic conductivity of the principal aquifer was estimated by calculating the thickness- weighted average of values assigned to different drillers' descriptions of material penetrated during the construction of 98 wells. Using these 98 control points, the study area was divided into zones representing approximate hydraulic- conductivity values of 20, 60, 100, 140, 180, 220, and 250 feet per day. This range of values is about the same range of values used in developing a ground-water flow model of the principal aquifer in the early 1980s. Porosity of the principal aquifer was estimated by compiling the range of porosity values determined or estimated during previous investigations of basin-fill sediments, and then using five different values ranging from 15 to 35 percent to delineate zones in the study area that were assumed to be underlain by similar deposits. Delineation of the zones was based on depositional history of the area and the distri- bution of sediments shown on a surficial geologic map. Water levels in wells were measured twice in 1990: during late winter when ground-water with- drawals were the least and water levels the highest, and again in late summer, when ground- water withdrawals were the greatest and water levels the lowest. These water levels were used to construct potentiometric-contour maps and subsequently to determine the variability of the slope in the potentiometric surface in the area. Values for the three properties, derived from the described sources of information, were used to produce a map showing the general distribution of average linear velocity of ground water moving through the principal aquifer of the study area. Velocity derived ranged from 0.06 to 144 feet per day with a median of about 3 feet per day. Values were slightly faster for late summer 1990 than for late winter 1990, mainly because increased with- drawal of water during the summer created slightly steeper hydraulic-head gradients between the recharge area near the mountain front and the well fields farther to the west. The fastest average linear-velocity values were located at the mouth of Little Cottonwood Canyon and south of Dry Creek near the mountain front, where the hydraulic con- ductivity was estimated to be the largest because the drillers described the sediments to be pre- dominantly clean and coarse grained. Both of these areas also had steep slopes in the potentiometric surface. Other areas where average linear velocity was fast included small areas near pumping wells where the slope in the potentiometric surface was locally steepened. No apparent relation between average linear velocity and porosity could be seen in the mapped distributions of these two properties. Calculation of travel time along a flow line to a well in the southwestern part of the study area during the sum

A semi-micromethod for determination of oxalate in human plasma.

PubMed

Porowski, Tadeusz; Gałasiński, Władysław

2003-01-01

An enzymatic semi-micromethod for oxalate determination in human plasma was elaborated. The principle of the method depends on the oxalate isolation from deproteinized plasma, following determination by the calorimetric oxalate oxidase-peroxidase-indamine system. This method protects against internal oxalate losses and excludes an interference of contaminations. Results, obtained by this method, were reliable and ideally suited for use as real normal values (less than or equal to 6 microM) of oxalate content in the plasma of healthy individuals. The elaborated method, which can assay plasma oxalate accurately in normal individuals as well as in hyperoxalemic conditions is superior to those previously used. The procedure of semi-micromethod does not require expensive equipments and apparatus: it is simple and easy to perform in every laboratory and takes little time.

Characterization of the Distribution of Siderophile and Highly Siderophile Elements in the Milton and Eagle Station Pallasites

NASA Technical Reports Server (NTRS)

Hillebrand, J. T.; McDonough, W. F.; Walker, R. J.; Piccoli, P. M.

2004-01-01

We examine the partitioning characteristics of several siderophile elements and HSE in the Eagle Station and Milton pallasites to determine if the D(sup Metal/Silicate) in natural systems are comparable to the range of values determined for synthetic systems. Eagle Station and Milton are particularly appropriate for this type of study because previous studies have shown that bulk samples of these meteorites have much higher abundances of siderophile elements and HSE than bulk samples of main group pallasites or mesosiderites. Thus, the expectation that initiated this study was that the abundances of at least some elements of interest present in the silicate phases may be at levels sufficiently high to be determined via in situ spot analysis using laser ablation ICP-MS.

Anchorage in Orthodontics: Three-dimensional Scanner Input

PubMed Central

Nabbout, Fidele; Baron, Pascal

2018-01-01

Aims and Objectives: The aim of this article is to re-evaluate anchorage coefficient values in orthodontics and their influence in the treatment decision through the usage of three-dimensional (3D) scanner. Materials and Methods: A sample of 80 patients was analyzed with the 3D scanner using the C2000 and Cepha 3DT softwares (CIRAD Montpellier, France). Tooth anatomy parameters (linear measurements, root, and crown volumes) were then calculated to determine new anchorage coefficients based on root volume. Data were collected and statistically evaluated with the StatView software (version 5.0). Results: The anchorage coefficient values found in this study are compared to those established in previous studies. These new values affect and modify our approach in orthodontic treatment from the standpoint of anchorage. Conclusion: The use of new anchorage coefficient values has significant clinical implications in conventional and in microimplants-assisted orthodontic mechanics through the selection and delivery of the optimal force system (magnitude and moment) for an adequate biological response. PMID:29629323

Threshold network of a financial market using the P-value of correlation coefficients

NASA Astrophysics Data System (ADS)

Ha, Gyeong-Gyun; Lee, Jae Woo; Nobi, Ashadun

2015-06-01

Threshold methods in financial networks are important tools for obtaining important information about the financial state of a market. Previously, absolute thresholds of correlation coefficients have been used; however, they have no relation to the length of time. We assign a threshold value depending on the size of the time window by using the P-value concept of statistics. We construct a threshold network (TN) at the same threshold value for two different time window sizes in the Korean Composite Stock Price Index (KOSPI). We measure network properties, such as the edge density, clustering coefficient, assortativity coefficient, and modularity. We determine that a significant difference exists between the network properties of the two time windows at the same threshold, especially during crises. This implies that the market information depends on the length of the time window when constructing the TN. We apply the same technique to Standard and Poor's 500 (S&P500) and observe similar results.

EXPERIMENTAL INVESTIGATION OF THE ORTHO/PARA RATIO OF NEWLY FORMED MOLECULAR HYDROGEN ON AMORPHOUS SOLID WATER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gavilan, L.; Lemaire, J. L.; Dulieu, F.

2012-11-20

Several astronomical observations have shown that the ortho/para ratio (OPR) of H{sub 2} can differ from the expected statistical value of 3 or the local thermodynamic equilibrium (LTE) value at the gas or dust temperature. It is thus important to know the OPR of H{sub 2} newly formed on dust grain surfaces, in order to clarify the dependence of the observed OPR in space on the formation process. Using an experimental setup designed to mimic interstellar medium environments, we measured the OPR of H{sub 2} and D{sub 2} formed on the surface of porous amorphous water ice held at 10more » K. We report for the first time the OPR value for newly formed D{sub 2}, consistent with the expected LTE value at the high-temperature limit found by previous theoretical and experimental works on the determination of the OPR upon H{sub 2} formation on surfaces at low temperature.« less

Reference values of coplanar and non-coplanar PCBs in serum samples from two Italian population groups.

PubMed

Turci, Roberta; Finozzi, Enrico; Catenacci, Giovanni; Marinaccio, Alessandro; Balducci, Claudio; Minoia, Claudio

2006-04-10

The main goal of this study is to establish the reference values of individual Polychlorinated biphenyl (PCB) congeners in non-occupationally exposed subjects. Since the PCB pattern in human serum is related to the living area, two different population groups from North and Central Italy, were compared. Serum concentrations of both coplanar and non-coplanar PCB congeners were measured by using gas chromatography coupled with low-resolution mass spectrometry (HRGC-LRMS). A fast and reliable method for the determination of 60 congeners had been previously validated. Its reliability was further verified by using high-resolution mass spectrometry. Thirty-one congeners out of 60 were found at detectable concentrations in at least one sample. The mean value for total PCBs was found to be 2.48 and 3.93 microg/L for the two population groups. Eight dioxin-like PCBs were detected. In accordance with the findings from the literature, the most abundant congeners were found to be 153, 138, 180, and 170. Both univariate and multivariate analysis showed that age is a significant determinant of PCB concentrations. The correlation increased with increasing chlorination. Slight differences in the PCB pattern were observed in the two population groups.

On the relationship between NMR-derived amide order parameters and protein backbone entropy changes

PubMed Central

Sharp, Kim A.; O’Brien, Evan; Kasinath, Vignesh; Wand, A. Joshua

2015-01-01

Molecular dynamics simulations are used to analyze the relationship between NMR-derived squared generalized order parameters of amide NH groups and backbone entropy. Amide order parameters (O2NH) are largely determined by the secondary structure and average values appear unrelated to the overall flexibility of the protein. However, analysis of the more flexible subset (O2NH < 0.8) shows that these report both on the local flexibility of the protein and on a different component of the conformational entropy than that reported by the side chain methyl axis order parameters, O2axis. A calibration curve for backbone entropy vs. O2NH is developed which accounts for both correlations between amide group motions of different residues, and correlations between backbone and side chain motions. This calibration curve can be used with experimental values of O2NH changes obtained by NMR relaxation measurements to extract backbone entropy changes, e.g. upon ligand binding. In conjunction with our previous calibration for side chain entropy derived from measured O2axis values this provides a prescription for determination of the total protein conformational entropy changes from NMR relaxation measurements. PMID:25739366

Effects of delay and probability combinations on discounting in humans

PubMed Central

Cox, David J.; Dallery, Jesse

2017-01-01

To determine discount rates, researchers typically adjust the amount of an immediate or certain option relative to a delayed or uncertain option. Because this adjusting amount method can be relatively time consuming, researchers have developed more efficient procedures. One such procedure is a 5-trial adjusting delay procedure, which measures the delay at which an amount of money loses half of its value (e.g., $1000 is valued at $500 with a 10-year delay to its receipt). Experiment 1 (n = 212) used 5-trial adjusting delay or probability tasks to measure delay discounting of losses, probabilistic gains, and probabilistic losses. Experiment 2 (n = 98) assessed combined probabilistic and delayed alternatives. In both experiments, we compared results from 5-trial adjusting delay or probability tasks to traditional adjusting amount procedures. Results suggest both procedures produced similar rates of probability and delay discounting in six out of seven comparisons. A magnitude effect consistent with previous research was observed for probabilistic gains and losses, but not for delayed losses. Results also suggest that delay and probability interact to determine the value of money. Five-trial methods may allow researchers to assess discounting more efficiently as well as study more complex choice scenarios. PMID:27498073

Determination of rhenium content in molybdenite by ICP-MS after separation of the major matrix by solvent extraction with N-benzoyl-N-phenylhydroxalamine.

PubMed

Li, Jie; Zhong, Li-feng; Tu, Xiang-lin; Liang, Xi-rong; Xu, Ji-feng

2010-05-15

A simple and rapid analytical method for determining the concentration of rhenium in molybdenite for Re-Os dating was developed. The method used isotope dilution-inductively coupled plasma-mass spectrometry (ID-ICP-MS) after the removal of major matrix elements (e.g., Mo, Fe, and W) from Re by solvent extraction with N-benzoyl-N-phenylhydroxylamine (BPHA) in chloroform solution. The effect on extraction efficiency of parameters such as pH (HCl concentration), BPHA concentration, and extraction time were also assessed. Under the optimal experimental conditions, the validity of the separation method was accessed by measuring (187)Re/(185)Re values for a molybdenite reference material (JDC). The obtained values were in good agreement with previously measured values of the Re standard. The proposed method was applied to replicate Re-Os dating of JDC and seven samples of molybdenite from the Yuanzhuding large Cu-Mo porphyry deposit. The results demonstrate good precision and accuracy for the proposed method. The advantages of the method (i.e., simplicity, efficiency, short analysis time, and low cost) make it suitable for routine analysis.

The Lamb shift in muonic hydrogen and the proton radius

NASA Astrophysics Data System (ADS)

Antognini, A.; Pohl, R.; Amaro, F. D.; Biraben, F.; Cardoso, J. M. R.; Covita, D. S.; Dax, A.; Dhawan, S.; Fernandes, L. M. P.; Giesen, A.; Gouvea, A. L.; Graf, T.; Ḧansch, T. W.; Hildebrandt, M.; Indelicato, P.; Julien, L.; Kao, C.-Y.; Kirch, K.; Knowles, P.; Le Bigot, E.-O.; Liu, Y.-W.; Lopes, J. A. M.; Ludhova, L.; Monteiro, C. M. B.; Mulhauser, F.; Nebel, T.; Nez, F.; Rabinowitz, P.; dos Santos, J. M. F.; Schaller, L. A.; Schuhmann, K.; Schwob, C.; Taqqu, D.; Veloso, J. F. C. A.; Voss, A.; Kottmann, F.

By means of pulsed laser spectroscopy applied to muonic hydrogen (μ- p) we have measured the 2S F = 1 1/2 - 2PF = 2 3/2 transition frequency to be 49881.88(76) GHz. By comparing this measurement with its theoretical prediction based on bound-state QED we have determined a proton radius value of rp = 0.84184 (67) fm. This new value is an order of magnitude preciser than previous results but disagrees by 5 standard deviations from the CODATA and the electronproton scattering values. An overview of the present effort attempting to solve the observed discrepancy is given. Using the measured isotope shift of the 1S-2S transition in regular hydrogen and deuterium also the rms charge radius of the deuteron rd = 2.12809 (31) fm has been determined. Moreover we present here the motivations for the measurements of the μ 4He + and μ 3He + 2S-2P splittings. The alpha and triton charge radii are extracted from these measurements with relative accuracies of few 10 - 4. Measurements could help to solve the observed discrepancy, lead to the best test of hydrogen-like energy levels and provide crucial tests for few-nucleon ab-initio theories and potentials.

Determining the ventilation and aerosol deposition rates from routine indoor-air measurements.

PubMed

Halios, Christos H; Helmis, Costas G; Deligianni, Katerina; Vratolis, Sterios; Eleftheriadis, Konstantinos

2014-01-01

Measurement of air exchange rate provides critical information in energy and indoor-air quality studies. Continuous measurement of ventilation rates is a rather costly exercise and requires specific instrumentation. In this work, an alternative methodology is proposed and tested, where the air exchange rate is calculated by utilizing indoor and outdoor routine measurements of a common pollutant such as SO2, whereas the uncertainties induced in the calculations are analytically determined. The application of this methodology is demonstrated, for three residential microenvironments in Athens, Greece, and the results are also compared against ventilation rates calculated from differential pressure measurements. The calculated time resolved ventilation rates were applied to the mass balance equation to estimate the particle loss rate which was found to agree with literature values at an average of 0.50 h(-1). The proposed method was further evaluated by applying a mass balance numerical model for the calculation of the indoor aerosol number concentrations, using the previously calculated ventilation rate, the outdoor measured number concentrations and the particle loss rates as input values. The model results for the indoors' concentrations were found to be compared well with the experimentally measured values.

On the relationship between NMR-derived amide order parameters and protein backbone entropy changes.

PubMed

Sharp, Kim A; O'Brien, Evan; Kasinath, Vignesh; Wand, A Joshua

2015-05-01

Molecular dynamics simulations are used to analyze the relationship between NMR-derived squared generalized order parameters of amide NH groups and backbone entropy. Amide order parameters (O(2) NH ) are largely determined by the secondary structure and average values appear unrelated to the overall flexibility of the protein. However, analysis of the more flexible subset (O(2) NH  < 0.8) shows that these report both on the local flexibility of the protein and on a different component of the conformational entropy than that reported by the side chain methyl axis order parameters, O(2) axis . A calibration curve for backbone entropy vs. O(2) NH is developed, which accounts for both correlations between amide group motions of different residues, and correlations between backbone and side chain motions. This calibration curve can be used with experimental values of O(2) NH changes obtained by NMR relaxation measurements to extract backbone entropy changes, for example, upon ligand binding. In conjunction with our previous calibration for side chain entropy derived from measured O(2) axis values this provides a prescription for determination of the total protein conformational entropy changes from NMR relaxation measurements. © 2015 Wiley Periodicals, Inc.

New methods for B meson decay constants and form factors from lattice NRQCD

NASA Astrophysics Data System (ADS)

Hughes, C.; Davies, C. T. H.; Monahan, C. J.; Hpqcd Collaboration

2018-03-01

We determine the normalization of scalar and pseudoscalar current operators made from nonrelativistic b quarks and highly improved staggered light quarks in lattice quantum chromodynamics (QCD) through O (αs) and ΛQCD/mb. We use matrix elements of these operators to extract B meson decay constants and form factors, and then compare to those obtained using the standard vector and axial-vector operators. This provides a test of systematic errors in the lattice QCD determination of the B meson decay constants and form factors. We provide a new value for the B and Bs meson decay constants from lattice QCD calculations on ensembles that include u , d , s , and c quarks in the sea and those that have the u /d quark mass going down to its physical value. Our results are fB=0.196 (6 ) GeV , fBs=0.236(7 ) GeV , and fB s/fB=1.207 (7 ), agreeing well with earlier results using the temporal axial current. By combining with these previous results, we provide updated values of fB=0.190 (4 ) GeV , fBs=0.229(5 ) GeV , and fB s/fB=1.206 (5 ).

Effects of pore size and dissolved organic matters on diffusion of arsenate in aqueous solution.

PubMed

Wang, Yulong; Wang, Shaofeng; Wang, Xin; Jia, Yongfeng

2017-02-01

Presented here is the influence of membrane pore size and dissolved organic matters on the diffusion coefficient (D) of aqueous arsenate, investigated by the diffusion cell method for the first time. The pH-dependent diffusion coefficient of arsenate was determined and compared with values from previous studies; the coefficient was found to decrease with increasing pH, showing the validity of our novel diffusion cell method. The D value increased dramatically as a function of membrane pore size at small pore sizes, and then increased slowly at pore sizes larger than 2.0μm. Using the ExpAssoc model, the maximum D value was determined to be 11.2565×10 -6 cm 2 /sec. The presence of dissolved organic matters led to a dramatic increase of the D of arsenate, which could be attributed to electrostatic effects and ionic effects of salts. These results improve the understanding of the diffusion behavior of arsenate, especially the important role of various environmental parameters in the study and prediction of the migration of arsenate in aquatic water systems. Copyright © 2016. Published by Elsevier B.V.

Inorganic particle analysis of dental impression elastomers.

PubMed

Carlo, Hugo Lemes; Fonseca, Rodrigo Borges; Soares, Carlos José; Correr, Américo Bortolazzo; Correr-Sobrinho, Lourenço; Sinhoreti, Mário Alexandre Coelho

2010-01-01

The aim of this study was to determine quantitatively and qualitatively the inorganic particle fraction of commercially available dental elastomers. The inorganic volumetric fraction of two addition silicones (Reprosil Putty/Fluid and Flexitime Easy Putty/Fluid), three condensation silicones (Clonage Putty/Fluid, Optosil Confort/Xantopren VL and Silon APS Putty/Fluid), one polyether (Impregum Soft Light Body) and one polysulfide (Permlastic Light Body) was accessed by weighing a previously determined mass of each material in water before and after burning samples at 600 ºC, during 3 h. Unsettled material samples were soaked in acetone and chloroform for removal of the organic portion. The remaining filler particles were sputter-coated with gold evaluation of their morphology and size, under scanning electron microscopy (SEM). Flexitime Easy Putty was the material with the highest results for volumetric particle fraction, while Impregum Soft had the lowest values. Silon 2 APS Fluid presented the lowest mean filler size values, while Clonage Putty had the highest values. SEM micrographs of the inorganic particles showed several morphologies - lathe-cut, spherical, spherical-like, sticks, and sticks mixed to lathe-cut powder. The results of this study revealed differences in particle characteristics among the elastometic materials that could lead to different results when testing mechanical properties.

Implementation of Online Promethee Method for Poor Family Change Rate Calculation

NASA Astrophysics Data System (ADS)

Aji, Dhady Lukito; Suryono; Widodo, Catur Edi

2018-02-01

This research has been done online calculation of the rate of poor family change rate by using Preference Ranking Method of Organization Of Enrichment Evaluation (PROMETHEE) .This system is very useful to monitor poverty in a region as well as for administrative services related to poverty rate. The system consists of computer clients and servers connected via the internet network. Poor family residence data obtained from the government. In addition, survey data are inputted through the client computer in each administrative village and also 23 criteria of input in accordance with the established government. The PROMETHEE method is used to evaluate the value of poverty and its weight is used to determine poverty status. PROMETHEE output can also be used to rank the poverty of the registered population of the server based on the netflow value. The poverty rate is calculated based on the current poverty rate compared to the previous poverty rate. The rate results can be viewed online and real time on the server through numbers and graphs. From the test results can be seen that the system can classify poverty status, calculate the poverty rate change rate and can determine the value and poverty ranking of each population.

Effects of fungal deterioration on grain: nutritional value, toxicity, germination.

PubMed

Sauer, D B

1988-12-01

Moulds or fungi that grow in grains and seeds during storage and transport cause germination decrease, visible mouldiness, discoloration, musty or sour odours, caking, chemical and nutritional changes, reduction in processing quality, and form of mycotoxins. These deteriorative changes affect the grade and price of grain and contribute to customer dissatisfaction when the grain is marketed. The respiration of grain and fungi results in a loss in dry matter as well as the production of heat and moisture which contribute to further spoilage. Net changes in nutritional value and the risk of mycotoxin contamination are difficult to predict because they depend on a complex interaction of factors such as temperature, moisture, storage time, fungal species composition, kind of grain, and previous storage history. Moisture is the most important variable determining the rate of deterioration caused by fungi, with temperature being the second major factor. Problems with deterioration of grain in export shipments are not a recent development. They are related primarily to grain moisture at loading, and also to the extent of previous mould invasion.

Stable isotope analysis at the molecular level: A new approach for determining the origins of amino acids in the Murchison meteorite

NASA Technical Reports Server (NTRS)

Engel, M. H.; Macko, S. A.; Qian, Y.; Silfer, J. A.

1995-01-01

A combined gas chromatography/isotope ratio mass spectrometry (GC/IRMS) method has been developed that permits the direct stable carbon isotope analysis of N(O)-trifluoroacetyl-isopropyl esters of individual amino acids and their respective enantiomers at nanomole abundances. Calculation of the original delta C-13 values of the amino acids is accomplished via a correction for the carbon introduced during the derivatization process. Previous GC/IRMS analyses of individual amino acids in the non-hydrolyzed water extract of an interior sample of a Murchison meteorite stone revealed an enrichment in C-13 relative to terrestrial organic matter, in agreement with previous findings for bulk extracts. The range of amino acid delta C-13 values (+5 to +30 per mill, PDB) suggests possible kinetic effects during synthesis. In this study, an apparent kinetic isotope effect was also observed for the amino acid products of a spark discharge experiment. These preliminary resutls are supportive of a similar mechanism for the abiotic synthesis of amino acids in the Murchison meteorite.

Measurement of radiation exposure of astronauts by radiochemical techniques

NASA Technical Reports Server (NTRS)

Brodzinski, R. L.

1972-01-01

Only two of the fecal specimens collected inflight during the Apollo 15 mission were returned for analysis. Difficulty in obtaining reasonably accurate radiation dose estimates based on the cosmogenic radionuclide content of the specimens was encountered due to the limited sampling. The concentrations of Na-22, K-40, Cr-51, Fe-59, and Cs-137 are reported. The concentrations of 24 major, minor, and trace elements in these two specimens were determined. Most concentrations are typical of those observed previously. Major exceptions are extremely low values for selenium and extraordinarily high values for rare earth elements. The net Po-210 activities in the Apollo 11 and 12 Solar Wind Composition foils and in the Apollo 8 and 12 spacecraft reflective coatings due to lunar exposure have been determined. Equilibrium concentrations of 0.082 + or - 0.012 disintegrations /sq cm sec of Rn-222 in the lunar atmosphere and 0.0238 + or - 0.0035 disintegrations /sq cm sec of Po-210 on the lunar surface have been calculated for Oceanus Procellarum.

Determination of the critical surface tension of wetting of minerals treated with surfactants by shear flocculation approach.

PubMed

Ozkan, A

2004-09-15

This paper contributes the shear flocculation method as a new approach to determine the critical surface tension of wetting of minerals treated with surfactants. This newly developed approach is based on the decrease of the shear flocculation of the mineral suspension, with decreasing of the surface tension of the liquids used. The solution surface tension value at which shear flocculation does not occur can be defined as the critical surface tension of wetting (gamma c) of the mineral. By using the shear flocculation method, the critical surface tensions of wetting (gamma c) for calcite and barite minerals, treated with surfactants, were obtained as 30.9 and 35.0 mN/m, respectively. These values are in good agreement with data reported previously on the same minerals obtained by the contact angle measurement and flotation methods. The chemical agents used for the treatment of calcite and barite particles were sodium oleate and sodium dodecyl sulfate, respectively.

Astronomical Methods in Aerial Navigation

NASA Technical Reports Server (NTRS)

Beij, K Hilding

1925-01-01

The astronomical method of determining position is universally used in marine navigation and may also be of service in aerial navigation. The practical application of the method, however, must be modified and adapted to conform to the requirements of aviation. Much of this work of adaptation has already been accomplished, but being scattered through various technical journals in a number of languages, is not readily available. This report is for the purpose of collecting under one cover such previous work as appears to be of value to the aerial navigator, comparing instruments and methods, indicating the best practice, and suggesting future developments. The various methods of determining position and their application and value are outlined, and a brief resume of the theory of the astronomical method is given. Observation instruments are described in detail. A complete discussion of the reduction of observations follows, including a rapid method of finding position from the altitudes of two stars. Maps and map cases are briefly considered. A bibliography of the subject is appended.

IMPROVED V II log(gf) VALUES, HYPERFINE STRUCTURE CONSTANTS, AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, M. P.; Lawler, J. E.; Den Hartog, E. A.

2014-10-01

New experimental absolute atomic transition probabilities are reported for 203 lines of V II. Branching fractions are measured from spectra recorded using a Fourier transform spectrometer and an echelle spectrometer. The branching fractions are normalized with radiative lifetime measurements to determine the new transition probabilities. Generally good agreement is found between this work and previously reported V II transition probabilities. Two spectrometers, independent radiometric calibration methods, and independent data analysis routines enable a reduction in systematic uncertainties, in particular those due to optical depth errors. In addition, new hyperfine structure constants are measured for selected levels by least squares fittingmore » line profiles in the FTS spectra. The new V II data are applied to high resolution visible and UV spectra of the Sun and metal-poor star HD 84937 to determine new, more accurate V abundances. Lines covering a range of wavelength and excitation potential are used to search for non-LTE effects. Very good agreement is found between our new solar photospheric V abundance, log ε(V) = 3.95 from 15 V II lines, and the solar-system meteoritic value. In HD 84937, we derive [V/H] = –2.08 from 68 lines, leading to a value of [V/Fe] = 0.24.« less

An Admittance Survey of Large Volcanoes on Venus: Implications for Volcano Growth

NASA Technical Reports Server (NTRS)

Brian, A. W.; Smrekar, S. E.; Stofan, E. R.

2004-01-01

Estimates of the thickness of the venusian crust and elastic lithosphere are important in determining the rheological and thermal properties of Venus. These estimates offer insights into what conditions are needed for certain features, such as large volcanoes and coronae, to form. Lithospheric properties for much of the large volcano population on Venus are not well known. Previous studies of elastic thickness (Te) have concentrated on individual or small groups of edifices, or have used volcano models and fixed values of Te to match with observations of volcano morphologies. In addition, previous studies use different methods to estimate lithospheric parameters meaning it is difficult to compare their results. Following recent global studies of the admittance signatures exhibited by the venusian corona population, we performed a similar survey into large volcanoes in an effort to determine the range of lithospheric parameters shown by these features. This survey of the entire large volcano population used the same method throughout so that all estimates could be directly compared. By analysing a large number of edifices and comparing our results to observations of their morphology and models of volcano formation, we can help determine the controlling parameters that govern volcano growth on Venus.

In vitro activity of chloramphenicol, florfenicol and enrofloxacin against Chlamydia pecorum isolated from koalas (Phascolarctos cinereus).

PubMed

Black, L A; Higgins, D P; Govendir, M

2015-11-01

To determine the in vitro susceptibilities of koala isolates of Chlamydia pecorum to enrofloxacin and chloramphenicol, which are frequently used to treat koalas with chlamydiosis, and florfenicol, a derivative of chloramphenicol. The in vitro susceptibilities were determined by culturing three stored isolates and seven clinical swabs of C. pecorum. Susceptibility testing was undertaken using cycloheximide-treated buffalo green monkey kidney cells in 96 well microtitre plates. The minimum inhibitory concentrations (MICs) for all isolates were 0.25-0.50 µg/mL (enrofloxacin), 1-2 µg/mL (chloramphenicol), and 1-2 µg/mL (florfenicol). Minimum bactericidal concentration (MBC) values for five isolates were also determined and were within one two-fold dilution of MICs. The MICs and MBCs of these antimicrobials were within ranges previously reported for other chlamydial species. When combined with previously published pharmacokinetic data, the in vitro susceptibility results support chloramphenicol as a more appropriate treatment option than enrofloxacin for koalas with chlamydiosis. The susceptibility results also indicate florfenicol may be an appropriate treatment option for koalas with chlamydiosis, warranting further investigation. © 2015 Australian Veterinary Association.

Determination of the energy value of corn distillers dried grains with solubles containing different oil levels when fed to growing pigs.

PubMed

Li, Z-C; Li, P; Liu, D-W; Li, D-F; Wang, F-L; Su, Y-B; Zhu, Z-P; Piao, X-S

2017-04-01

This experiment used indirect calorimetry to determine the net energy (NE) content of five corn distillers dried grains with solubles (corn DDGS) containing different oil levels and to compare the NE obtained using indirect calorimetry with that calculated using previously published prediction equations. There were two samples of high-oil DDGS, one sample of medium-oil DDGS and two samples of low-oil DDGS. Twelve barrows (initial BW of 32.8 ± 2.0 kg) were used in a repeated 3 × 6 Youden square design with three periods and six diets. The diets were comprised of a corn-soybean meal basal diet and five diets containing 29.25% of one of the corn DDGS added at the expense of corn and soybean meal. During each period, the pigs were individually housed in metabolism crates for 16 days which included 7 days for adaption to feed and environmental conditions. On day 8, the pigs were transferred to respiration chambers and fed one of the six diets at 2300 kJ ME/kg BW 0.6 /day. Faeces and urine were collected from day 9 to 13 and heat production (HP) was also measured. From day 14 to 15, the pigs were fed 893 kJ ME/kg BW 0.6 /day to allow them to adapt from the fed to the fasted state. On the last day of each period (day 16), the pigs were fasted and fasting HP was measured. The digestible energy value was 16.0, 17.1 and 15.3 MJ/kg DM, the metabolizable energy value was 14.6, 15.5 and 13.7 MJ/kg DM and the NE value was 10.7, 11.0 and 9.4 MJ/kg DM, for the high-oil, medium-oil and low-oil corn DDGS, respectively. The NE obtained with indirect calorimetry in the present study did not differ from values calculated using previously published prediction equations. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

Fidelity of the representation of value in decision-making

PubMed Central

Dowding, Ben A.

2017-01-01

The ability to make optimal decisions depends on evaluating the expected rewards associated with different potential actions. This process is critically dependent on the fidelity with which reward value information can be maintained in the nervous system. Here we directly probe the fidelity of value representation following a standard reinforcement learning task. The results demonstrate a previously-unrecognized bias in the representation of value: extreme reward values, both low and high, are stored significantly more accurately and precisely than intermediate rewards. The symmetry between low and high rewards pertained despite substantially higher frequency of exposure to high rewards, resulting from preferential exploitation of more rewarding options. The observed variation in fidelity of value representation retrospectively predicted performance on the reinforcement learning task, demonstrating that the bias in representation has an impact on decision-making. A second experiment in which one or other extreme-valued option was omitted from the learning sequence showed that representational fidelity is primarily determined by the relative position of an encoded value on the scale of rewards experienced during learning. Both variability and guessing decreased with the reduction in the number of options, consistent with allocation of a limited representational resource. These findings have implications for existing models of reward-based learning, which typically assume defectless representation of reward value. PMID:28248958

Space shuttle engineering and operations support. Orbiter to spacelab electrical power interface. Avionics system engineering

NASA Technical Reports Server (NTRS)

Emmons, T. E.

1976-01-01

The results are presented of an investigation of the factors which affect the determination of Spacelab (S/L) minimum interface main dc voltage and available power from the orbiter. The dedicated fuel cell mode of powering the S/L is examined along with the minimum S/L interface voltage and available power using the predicted fuel cell power plant performance curves. The values obtained are slightly lower than current estimates and represent a more marginal operating condition than previously estimated.

Using Hysteretic Energy to Evaluate Damping Characteristics of Hard Coating on Titanium

DTIC Science & Technology

2013-03-21

Ivancic, Frank T. The Effect of a Hard Coating on the Damping and Fatigue Life of Titanium. Air Force Institute of Technology (AU), Wright-Patterson AFB... aluminum specimens to determine the effects of losses for different grip mechanisms, a suspected problem in previous work with this method. Peak...done in a vacuum, and the nature of the free-decay test also confines strain to relatively low values for coated specimens (< 1000 µε) (Reed 2007

Collisionless dissociation and isotopic enrichment of SF6 using high-powered CO2 laser radiation

NASA Technical Reports Server (NTRS)

Gower, M. C.; Billman, K. W.

1977-01-01

Dissociation of S-32F6 and the resultant isotopic enrichment of S-34F6 using high-powered CO2 laser radiation has been studied with higher experimental sensitivity than previously reported. Enrichment factors have been measured as a function of laser pulse number, wavelength, energy and time duration. A geometry independent dissociation cross section is introduced and measured values are presented. Threshold energy densities, below which no dissociation was observed, were also determined.

Intensity formulas for triplet bands

NASA Technical Reports Server (NTRS)

Budo, A.

1982-01-01

Previous work in this area is surveyed and the mathematics involved in determining the quantitative intensity measurements in triplet bands is presented. Explicit expressions for the intensity distribution in the branches of the 3 Sigma-3 Pi and 1 Sigma-3Pi bands valid for all values of the coupling constant Y of the 3 Pi terms are given. The intensity distribution calculated according to the formulas given is compared with measurements of PH, 3 Pi-3 Sigma. Good quantitative agreement is obtained.

Correlating cookoff violence with pre-ignition damage.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wente, William Baker; Hobbs, Michael L.; Kaneshige, Michael Jiro

Predicting the response of energetic materials during accidents, such as fire, is important for high consequence safety analysis. We hypothesize that responses of ener-getic materials before and after ignition depend on factors that cause thermal and chemi-cal damage. We have previously correlated violence from PETN to the extent of decom-position at ignition, determined as the time when the maximum Damkoehler number ex-ceeds a threshold value. We seek to understand if our method of violence correlation ap-plies universally to other explosive starting with RDX.

Determination of HART I Blade Structural Properties by Laboratory Testing

NASA Technical Reports Server (NTRS)

Jung, Sung N.; Lau, Benton H.

2012-01-01

The structural properties of higher harmonic Aeroacoustic Rotor Test (HART I) blades were measured using the original set of blades tested in the German-dutch wind tunnel (DNW) in 1994. the measurements include bending and torsion stiffness, geometric offsets, and mass and inertia properties of the blade. the measured properties were compared to the estimated values obtained initially from the blade manufacturer. The previously estimated blade properties showed consistently higher stiffness, up to 30 percent for the flap bending in the blade inboard root section.

Methods to determine pumped irrigation-water withdrawals from the Snake River between Upper Salmon Falls and Swan Falls Dams, Idaho, using electrical power data, 1990-95

USGS Publications Warehouse

Maupin, Molly A.

1999-01-01

Pumped withdrawals compose most of the irrigation-water diversions from the Snake River between Upper Salmon Falls and Swan Falls Dams in southwestern Idaho. Pumps at 32 sites along the reach lift water as high as 745 feet to irrigate croplands on plateaus north and south of the river. The number of pump sites at which withdrawals are being continuously measured has been steadily decreasing, from 32 in 1990 to 7 in 1998. A cost-effective and accurate means of estimating annual irrigation-water withdrawals at pump sites that are no longer continuously measured was needed. Therefore, the U.S. Geological Survey began a study in 1998, as part of its Water-Use Program, to determine power-consumption coeffi- cients (PCCs) for each pump site so that withdrawals could be estimated by using electrical powerconsumption and total head data. PCC values for each pump site were determined by using withdrawal data that were measured by the U.S. Geological Survey during 1990–92 and 1994–95, energy data reported by Idaho Power Company during the same period, and total head data collected at each site during a field inventory in 1998. Individual average annual withdrawals for the 32 pump sites ranged from 1,120 to 44,480 acre-feet; average PCC values ranged from 103 to 1,248 kilowatthours per acre-foot. During the 1998 field season, power demand, total head, and withdrawal at 18 sites were measured to determine 1998 PCC values. Most of the 1998 PCC values were within 10 percent of the 5-year average, which demonstrates that withdrawals for a site that is no longer continuously measured can be calculated with reasonable accuracy by using the PCC value determined from this study and annual power-consumption data. K-factors, coefficients that describe the amount of energy necessary to lift water, were determined for each pump site by using values of PCC and total head and ranged from 1.11 to 1.89 kilowatthours per acre-foot per foot. Statistical methods were used to define the relations among PCC values and selected pumpsite characteristics. Multiple correlation analysis between average PCC values and total head, total horsepower, and total number of pumps revealed the strongest correlation was between average PCC and total head. Linear regression of these two variables resulted in a strong coefficient of determination R2=0 .9 86) and a representative K-factor of 1.463. Pump sites were subdivided into two groups on the basis of total head—0 to 300 feet and greater than 300 feet. Regression of average PCC values for eight pump sites with total head less than 300 feet produced a good correlation of determination (R2=0.870) and a representative K-factor of 1.682. The second group consisted of 10 pump sites with total head greater than 300 feet; regression produced a correlation of R2=0.939 and a representative K-factor of 1.405. Data on pump-site characteristics were successfully used to determine individual PCC and K-factor values. Statistical relations between pumpsite characteristics and PCC values were defined and used to determine regression equations that resulted in good coefficients of determination and representative K-factors. The individual PCC values will be used in the future to calculate irrigation- water withdrawals at sites that are no longer continuously measured. The representative K-factors and regression equations will be used to calculate irrigation-water withdrawals at sites that have not been previously measured and where total head and power consumption are known.

Active Thermochemical Tables: The Adiabatic Ionization Energy of Hydrogen Peroxide.

PubMed

Changala, P Bryan; Nguyen, T Lam; Baraban, Joshua H; Ellison, G Barney; Stanton, John F; Bross, David H; Ruscic, Branko

2017-11-22

The adiabatic ionization energy of hydrogen peroxide (HOOH) is investigated, both by means of theoretical calculations and theoretically assisted reanalysis of previous experimental data. Values obtained by three different approaches: 10.638 ± 0.012 eV (purely theoretical determination), 10.649 ± 0.005 eV (reanalysis of photoelectron spectrum), and 10.645 ± 0.010 eV (reanalysis of photoionization spectrum) are in excellent mutual agreement. Further refinement of the latter two values to account for asymmetry of the rotational profile of the photoionization origin band leads to a reduction of 0.007 ± 0.006 eV, which tends to bring them into even closer alignment with the purely theoretical value. Detailed analysis of this fundamental quantity by the Active Thermochemical Tables approach, using the present results and extant literature, gives a final estimate of 10.641 ± 0.006 eV.

Enhanced collectivity along the N = Z line: Lifetime measurements in 44Ti, 48Cr, and 52Fe

NASA Astrophysics Data System (ADS)

Arnswald, K.; Braunroth, T.; Seidlitz, M.; Coraggio, L.; Reiter, P.; Birkenbach, B.; Blazhev, A.; Dewald, A.; Fransen, C.; Fu, B.; Gargano, A.; Hess, H.; Hirsch, R.; Itaco, N.; Lenzi, S. M.; Lewandowski, L.; Litzinger, J.; Müller-Gatermann, C.; Queiser, M.; Rosiak, D.; Schneiders, D.; Siebeck, B.; Steinbach, T.; Vogt, A.; Wolf, K.; Zell, K. O.

2017-09-01

Lifetimes of the 21+ states in 44Ti, 48,50Cr, and 52Fe were determined with high accuracy exploiting the recoil distance Doppler-shift method. The reduced E2 transition strengths of 44Ti and 52Fe differ considerably from previously known values. A systematic increase in collectivity is found for the N = Z nuclei compared to neighboring isotopes. The B (E2) values along the Ti, Cr, and Fe isotopic chains are compared to shell-model calculations employing established interactions for the 0 f 1 p shell, as well as a novel effective shell-model Hamiltonian starting from a realistic nucleon-nucleon potential. The theoretical approaches underestimate the B (E2) values for the lower-mass Ti isotopes. Strong indication is found for particle-hole cross-shell configurations, recently corroborated by similar results for the neighboring isotone 42Ca.

Active Thermochemical Tables: The Adiabatic Ionization Energy of Hydrogen Peroxide

DOE PAGES

Changala, P. Bryan; Nguyen, T. Lam; Baraban, Joshua H.; ...

2017-09-07

The adiabatic ionization energy of hydrogen peroxide (HOOH) is investigated, both by means of theoretical calculations and theoretically-assisted reanalysis of previous experimental data. Values obtained by three different approaches: 10.638 ± 0.012 eV (purely theoretical determination), 10.649 ± 0.005 eV (reanalysis of photoelectron spectrum) and 10.645 ± 0.010 eV (reanalysis of photoionization spectrum) are in excellent mutual agreement. Further refinement of the latter two values to account for asymmetry of the rotational profile of the photoionization origin band leads to a reduction of 0.007 ± 0.006 eV, which tends to bring them into even closer alignment with the purely theoreticalmore » value. As a result, detailed analysis of this fundamental quantity by the Active Thermochemical Tables (ATcT) approach, using the present results and extant literature, gives a final estimate of 10.641 ± 0.006 eV.« less

Facial tissue depths in children with cleft lip and palate.

PubMed

Starbuck, John M; Ghoneima, Ahmed; Kula, Katherine

2015-03-01

Cleft lip and palate (CLP) is a craniofacial malformation affecting more than seven million people worldwide that results in defects of the hard palate, teeth, maxilla, nasal spine and floor, and maxillodental asymmetry. CLP facial soft-tissue depth (FSTD) values have never been published. The purpose of this research is to report CLP FSTD values and compare them to previously published FSTD values for normal children. Thirty-eight FSTDs were measured on cone beam computed tomography images of CLP children (n = 86; 7-17 years). MANOVA and ANOVA tests determined whether cleft type, age, sex, and bone graft surgical status affect tissue depths. Both cleft type (unilateral/bilateral) and age influence FSTDs. CLP FSTDs exhibit patterns of variation that differ from normal children, particularly around the oronasal regions of the face. These differences should be taken into account when facial reconstructions of children with CLP are created. © 2014 American Academy of Forensic Sciences.

The influence of liberal political ideology on nursing science.

PubMed

Browne, A J

2001-06-01

Previous notions of science as impartial and value-neutral have been refuted by contemporary views of science as influenced by social, political and ideological values. By locating nursing science in the dominant political ideology of liberalism, the author examines how nursing knowledge is influenced by liberal philosophical assumptions. The central tenets of liberal political philosophy - individualism, egalitarianism, freedom, tolerance, neutrality, and a free-market economy - are primarily manifested in relation to: (i) the individualistic focus of our science; (ii) our view of society as essentially egalitarian and equitable; (iii) our preference for politically neutral knowledge development, and (iv) an economy of knowledge development that supports rather than challenges the status quo. I argue that exposing, rather than ignoring, the liberal ideological values inherent in nursing science will render these assumptions open to debate, stimulate ongoing development of critically oriented knowledge, and increase our capacity to influence the social, political and economic determinants of health.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Changala, P. Bryan; Nguyen, T. Lam; Baraban, Joshua H.

The adiabatic ionization energy of hydrogen peroxide (HOOH) is investigated, both by means of theoretical calculations and theoretically-assisted reanalysis of previous experimental data. Values obtained by three different approaches: 10.638 ± 0.012 eV (purely theoretical determination), 10.649 ± 0.005 eV (reanalysis of photoelectron spectrum) and 10.645 ± 0.010 eV (reanalysis of photoionization spectrum) are in excellent mutual agreement. Further refinement of the latter two values to account for asymmetry of the rotational profile of the photoionization origin band leads to a reduction of 0.007 ± 0.006 eV, which tends to bring them into even closer alignment with the purely theoreticalmore » value. As a result, detailed analysis of this fundamental quantity by the Active Thermochemical Tables (ATcT) approach, using the present results and extant literature, gives a final estimate of 10.641 ± 0.006 eV.« less

A unified relation for the solid-liquid interface free energy of pure FCC, BCC, and HCP metals.

PubMed

Wilson, S R; Mendelev, M I

2016-04-14

We study correlations between the solid-liquid interface (SLI) free energy and bulk material properties (melting temperature, latent heat, and liquid structure) through the determination of SLI free energies for bcc and hcp metals from molecular dynamics (MD) simulation. Values obtained for the bcc metals in this study were compared to values predicted by the Turnbull, Laird, and Ewing relations on the basis of previously published MD simulation data. We found that of these three empirical relations, the Ewing relation better describes the MD simulation data. Moreover, whereas the original Ewing relation contains two constants for a particular crystal structure, we found that the first coefficient in the Ewing relation does not depend on crystal structure, taking a common value for all three phases, at least for the class of the systems described by embedded-atom method potentials (which are considered to provide a reasonable approximation for metals).

A unified relation for the solid-liquid interface free energy of pure FCC, BCC, and HCP metals

NASA Astrophysics Data System (ADS)

Wilson, S. R.; Mendelev, M. I.

2016-04-01

We study correlations between the solid-liquid interface (SLI) free energy and bulk material properties (melting temperature, latent heat, and liquid structure) through the determination of SLI free energies for bcc and hcp metals from molecular dynamics (MD) simulation. Values obtained for the bcc metals in this study were compared to values predicted by the Turnbull, Laird, and Ewing relations on the basis of previously published MD simulation data. We found that of these three empirical relations, the Ewing relation better describes the MD simulation data. Moreover, whereas the original Ewing relation contains two constants for a particular crystal structure, we found that the first coefficient in the Ewing relation does not depend on crystal structure, taking a common value for all three phases, at least for the class of the systems described by embedded-atom method potentials (which are considered to provide a reasonable approximation for metals).

Radiative transfer in the surfaces of atmosphereless bodies. III - Interpretation of lunar photometry

NASA Technical Reports Server (NTRS)

Lumme, K.; Irvine, W. M.

1982-01-01

Narrowband and UBV photoelectric phase curves of the entire lunar disk and surface photometry of some craters have been interpreted using a newly developed generalized radiative transfer theory for planetary regoliths. The data are well fitted by the theory, yielding information on both macroscopic and microscopic lunar properties. Derived values for the integrated disk geometric albedo are considerably higher than quoted previously, because of the present inclusion of an accurately determined opposition effect. The mean surface roughness, defined as the ratio of the height to the radius of a typical irregularity, is found to be 0.9 + or - 0.1, or somewhat less than the mean value of 1.2 obtained for the asteroids. From the phase curves, wavelength-dependent values of the single scattering albedo and the Henyey-Greenstein asymmetry factor for the average surface particle are derived.

Spectral analysis of 87-lead body surface signal-averaged ECGs in patients with previous anterior myocardial infarction as a marker of ventricular tachycardia.

PubMed

Hosoya, Y; Kubota, I; Shibata, T; Yamaki, M; Ikeda, K; Tomoike, H

1992-06-01

There were few studies on the relation between the body surface distribution of high- and low-frequency components within the QRS complex and ventricular tachycardia (VT). Eighty-seven signal-averaged ECGs were obtained from 30 normal subjects (N group) and 30 patients with previous anterior myocardial infarction (MI) with VT (MI-VT[+] group, n = 10) or without VT (MI-VT[-] group, n = 20). The onset and offset of the QRS complex were determined from 87-lead root mean square values computed from the averaged (but not filtered) ECG waveforms. Fast Fourier transform analysis was performed on signal-averaged ECG. The resulting Fourier coefficients were attenuated by use of the transfer function, and then inverse transform was done with five frequency ranges (0-25, 25-40, 40-80, 80-150, and 150-250 Hz). From the QRS onset to the QRS offset, the time integration of the absolute value of reconstructed waveforms was calculated for each of the five frequency ranges. The body surface distributions of these areas were expressed as QRS area maps. The maximal values of QRS area maps were compared among the three groups. In the frequency ranges of 0-25 and 150-250 Hz, there were no significant differences in the maximal values among these three groups. Both MI groups had significantly smaller maximal values of QRS area maps in the frequency ranges of 25-40 and 40-80 Hz compared with the N group. The MI-VT(+) group had significantly smaller maximal values in the frequency ranges of 40-80 and 80-150 Hz than the MI-VT(-) group. These three groups were clearly differentiated by the maximal values of the 40-80-Hz QRS area map. It was suggested that the maximal value of the 40-80-Hz QRS area map was a new marker for VT after anterior MI.

A vacuum ultraviolet laser pulsed field ionization-photoion study of methane (CH 4): Determination of the appearance energy of methylium from methane with unprecedented precision and the resulting impact on the bond dissociation energies of CH 4 and CH 4 +

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Yih -Chung; Xiong, Bo; Bross, David H.

Here, we report on the successful implementation of a high-resolution vacuum ultraviolet (VUV) laser pulsed field ionization-photoion (PFI-PI) detection method for the study of unimolecular dissociation of quantum-state- or energy-selected molecular ions. As a test case, we have determined the 0 K appearance energy (AE 0) for the formation of methylium, CH 3 +, from methane, CH 4, as AE 0 (CH 3 +/CH 4) = 14.32271 ± 0.00013 eV. This value has a significantly smaller error limit, but is otherwise consistent with previous laboratory and/or synchrotron-based studies of this dissociative photoionization onset. Furthermore, the sum of the VUV lasermore » PFI-PI spectra obtained for the parent CH 4 + ion and the fragment CH 3 + ions of methane is found to agree with the earlier VUV pulsed field ionization-photoelectron (VUV-PFI-PE) spectrum of methane, providing unambiguous validation of the previous interpretation that the sharp VUV-PFI-PE step observed at the AE 0 (CH 3 +/CH 4) threshold ensues because of higher PFI detection efficiency for fragment CH 3 + than for parent CH 4 +. This, in turn, is a consequence of the underlying high- n Rydberg dissociation mechanism for the dissociative photoionization of CH 4, which was proposed in previous synchrotron-based VUV-PFI-PE and VUV-PFI-PEPICO studies of CH 4. The present highly accurate 0 K dissociative ionization threshold for CH 4 can be utilized to derive accurate values for the bond dissociation energies of methane and methane cation. For methane, the straightforward application of sequential thermochemistry via the positive ion cycle leads to some ambiguity because of two competing VUV-PFI-PE literature values for the ionization energy of methyl radical. The ambiguity is successfully resolved by applying the Active Thermochemical Tables (ATcT) approach, resulting in D 0 (H-CH 3) = 432.463 ± 0.027 kJ/mol and D 0(H-CH 3 +) = 164.701 ± 0.038 kJ/mol.« less

A vacuum ultraviolet laser pulsed field ionization-photoion study of methane (CH 4): Determination of the appearance energy of methylium from methane with unprecedented precision and the resulting impact on the bond dissociation energies of CH 4 and CH 4 +

DOE PAGES

Chang, Yih -Chung; Xiong, Bo; Bross, David H.; ...

2017-03-27

Here, we report on the successful implementation of a high-resolution vacuum ultraviolet (VUV) laser pulsed field ionization-photoion (PFI-PI) detection method for the study of unimolecular dissociation of quantum-state- or energy-selected molecular ions. As a test case, we have determined the 0 K appearance energy (AE 0) for the formation of methylium, CH 3 +, from methane, CH 4, as AE 0 (CH 3 +/CH 4) = 14.32271 ± 0.00013 eV. This value has a significantly smaller error limit, but is otherwise consistent with previous laboratory and/or synchrotron-based studies of this dissociative photoionization onset. Furthermore, the sum of the VUV lasermore » PFI-PI spectra obtained for the parent CH 4 + ion and the fragment CH 3 + ions of methane is found to agree with the earlier VUV pulsed field ionization-photoelectron (VUV-PFI-PE) spectrum of methane, providing unambiguous validation of the previous interpretation that the sharp VUV-PFI-PE step observed at the AE 0 (CH 3 +/CH 4) threshold ensues because of higher PFI detection efficiency for fragment CH 3 + than for parent CH 4 +. This, in turn, is a consequence of the underlying high- n Rydberg dissociation mechanism for the dissociative photoionization of CH 4, which was proposed in previous synchrotron-based VUV-PFI-PE and VUV-PFI-PEPICO studies of CH 4. The present highly accurate 0 K dissociative ionization threshold for CH 4 can be utilized to derive accurate values for the bond dissociation energies of methane and methane cation. For methane, the straightforward application of sequential thermochemistry via the positive ion cycle leads to some ambiguity because of two competing VUV-PFI-PE literature values for the ionization energy of methyl radical. The ambiguity is successfully resolved by applying the Active Thermochemical Tables (ATcT) approach, resulting in D 0 (H-CH 3) = 432.463 ± 0.027 kJ/mol and D 0(H-CH 3 +) = 164.701 ± 0.038 kJ/mol.« less

Noble gas isotopes in mineral springs within the Cascadia Forearc, Wasihington and Oregon

USGS Publications Warehouse

McCrory, Patricia A.; Constantz, James E.; Hunt, Andrew G.

2014-01-01

This U.S. Geological Survey report presents laboratory analyses along with field notes for a pilot study to document the relative abundance of noble gases in mineral springs within the Cascadia forearc of Washington and Oregon. Estimates of the depth to the underlying Juan de Fuca oceanic plate beneath the sample sites are derived from the McCrory and others (2012) slab model. Some of these springs have been previously sampled for chemical analyses (Mariner and others, 2006), but none currently have publicly available noble gas data. Helium isotope values as well as the noble gas values and ratios presented below will be used to determine the sources and mixing history of these mineral waters.

Apparatus And Method For Reconstructing Data Using Cross-Parity Stripes On Storage Media

DOEpatents

Hughes, James Prescott

2003-06-17

An apparatus and method for reconstructing missing data using cross-parity stripes on a storage medium is provided. The apparatus and method may operate on data symbols having sizes greater than a data bit. The apparatus and method makes use of a plurality of parity stripes for reconstructing missing data stripes. The parity symbol values in the parity stripes are used as a basis for determining the value of the missing data symbol in a data stripe. A correction matrix is shifted along the data stripes, correcting missing data symbols as it is shifted. The correction is performed from the outside data stripes towards the inner data stripes to thereby use previously reconstructed data symbols to reconstruct other missing data symbols.

Negative measurement sensitivity values of planar capacitive imaging probes

NASA Astrophysics Data System (ADS)

Yin, Xiaokang; Chen, Guoming; Li, Wei; Hutchins, David

2014-02-01

The measurement sensitivity distribution of planar capacitive imaging (CI) probes describes how effectively each region in the sensing area is contributing to the measured charge signal on the sensing electrode. It can be used to determine the imaging ability of a CI probe. It is found in previous work that, there are regions in the sensing area where the change of the charge output and the change of targeting physical parameter are of opposite trends. This opposite correlation implies that the measurement sensitivity values in such regions are negative. In this work, the cause of negative sensitivity is discussed. Experiments are also designed and performed so as to verify the existence of negative sensitivity and study the factors that may affect the negative sensitivity distributions.

Polarized photon scattering off 52Cr: Determining the parity of J =1 states

NASA Astrophysics Data System (ADS)

Krishichayan, Bhike, Megha; Tornow, W.; Rusev, G.; Tonchev, A. P.; Tsoneva, N.; Lenske, H.

2015-04-01

The photoresponse of 52Cr has been investigated in the energy range of 5.0-9.5 MeV using the photon scattering technique at the HI γ S facility of TUNL to complement previous work with unpolarized bremsstrahlung photon beams at the Darmstadt linear electron accelerator. The unambiguous parity determinations of the observed J =1 states provides the basis needed to better understand the structure of E 1 and M 1 excitations. Theoretical calculations using the quasiparticle phonon model incorporating self-consistent energy-density functional theory were performed to investigate the fragmentation pattern of the dipole strength below and around the neutron-emission threshold. These results compare very well with the experimental values.

Reliability analysis of composite laminates with load sharing

NASA Technical Reports Server (NTRS)

Wetherhold, Robert C.; Thomas, David J.

1991-01-01

By viewing a composite lamina as a homogeneous solid whose directional strengths are random variables, lamina reliability under multiaxial stresses may be determined using either an interactive or a noninteractive criterion. From the reliability values for the individual laminae comprising a given laminate, Thomas and Wetherhold (1991) have proposed a method for determining bounds for the overall laminate reliability. In this paper, simple physically plausible phenomenological rules are proposed for redistribution of load after a lamina has failed within the confines of a laminate. These rules are illustrated by application to (0/ +/-15)s and (90/ +/-45/0)s graphite/epoxy laminates, and the results are compared to the previously proposed bounds.

Determination of silicon in biological and botanical reference materials by epithermal INAA and Compton suppression

NASA Astrophysics Data System (ADS)

Landsberger, S.; Peshev, S.; Becker, D. A.

1994-12-01

Silicon determination in sixteen botanical and biological standard reference materials is described using the 29Si(n, p) 29Al reaction through instrumental epithermal neutron activation analysis and Compton suppression gamma-ray spectroscopy. By simultaneous utilization of both cadmium and boron epithermal filters along with anticoincidence gamma-counting, detection limits as low as 12 ppm were obtained for certain matrices, much lower than previously reported values for this type of analysis. The method is applicable to many botanical and biological matrices and is attractive with its interference free, purely instrumental nature, compared with methods using the 28Si(n, p) 28Al reaction or chemical separation techniques.

Determination of relative krypton fission product yields from 14 MeV neutron induced fission of 238U at the National Ignition Facility

DOE PAGES

Edwards, E. R.; Cassata, W. S.; Velsko, C. A.; ...

2016-09-22

Precisely-known fission yield distributions are needed to determine a fissioning isotope and the incident neutron energy in nuclear security applications. 14 MeV neutrons from DT fusion at the National Ignition Facility (NIF) induce fission in depleted uranium (DU) contained in the target assembly hohlraum. The fission yields of Kr isotopes (85m, 87, 88, and 89) are measured relative to the cumulative yield of 88Kr and compared to previously tabulated values. Here, the results from this experiment and England and Rider are in agreement, except for the 85mKr/ 88Kr ratio, which may be the result of incorrect nuclear data.

Challenging the ‘Big G’ measurement with atoms and light

NASA Astrophysics Data System (ADS)

Rosi, Gabriele

2016-10-01

The measurement of the Newtonian gravity constant G is a formidable task. Starting from the first determination made by Henry Cavendish in 1798, several attempts have been made in order to improve knowledge of its value. Nevertheless, despite these efforts, its uncertainty has decreased only by a factor of ten per century. Cold atom interferometry represents a conceptually different technique to challenge the G measurement, a feature that is crucial in order to identify discrepancies among previous measurements. In this review paper, after a short introduction on the traditional measurement techniques, I will describe and discuss past and ongoing G determination based on atom interferometry, highlighting for each of them the most significant aspects.

Precision islands in the Ising and O(N ) models

DOE PAGES

Kos, Filip; Poland, David; Simmons-Duffin, David; ...

2016-08-04

We make precise determinations of the leading scaling dimensions and operator product expansion (OPE) coefficients in the 3d Ising, O(2), and O(3) models from the conformal bootstrap with mixed correlators. We improve on previous studies by scanning over possible relative values of the leading OPE coefficients, which incorporates the physical information that there is only a single operator at a given scaling dimension. The scaling dimensions and OPE coefficients obtained for the 3d Ising model, (Δ σ , Δ ϵ , λ σσϵ , λ ϵϵϵ ) = (0.5181489(10), 1.412625(10), 1.0518537(41), 1.532435(19) , give the most precise determinations of thesemore » quantities to date.« less

High-resolution spectroscopy of the 1S-2S transition of atomic hydrogen and deuterium

NASA Astrophysics Data System (ADS)

Schmidt-Kaler, F.; Leibfried, D.; Seel, S.; Zimmermann, C.; König, W.; Weitz, M.; Hänsch, T. W.

1995-04-01

Two-photon spectroscopy of the hydrogen 1S-2S transition in a cold atomic beam has reached a resolution Δν/ν of 1 part in 1011 in hydrogen and 7 parts in 1012 in deuterium. The hydrogen and deuterium 1S-2S transition frequencies have been determined with a precision of 1 part in 1011. This leads to an accurate value for the Rydberg constant, while the 1S Lamb shift and the isotope shift are determined with order of magnitude improvements over previous measurements. We describe in detail the 1S-2S spectrometer, calculate the line shape of the resonance, and compare it to the experimental data.

Determination of relative krypton fission product yields from 14 MeV neutron induced fission of 238U at the National Ignition Facility.

PubMed

Edwards, E R; Cassata, W S; Velsko, C A; Yeamans, C B; Shaughnessy, D A

2016-11-01

Precisely-known fission yield distributions are needed to determine a fissioning isotope and the incident neutron energy in nuclear security applications. 14 MeV neutrons from DT fusion at the National Ignition Facility induce fission in depleted uranium contained in the target assembly hohlraum. The fission yields of Kr isotopes (85m, 87, 88, and 89) are measured relative to the cumulative yield of 88 Kr and compared to previously tabulated values. The results from this experiment and England and Rider are in agreement, except for the 85m Kr/ 88 Kr ratio, which may be the result of incorrect nuclear data.

Determination of elemental carbon in lake sediments using a thermal-optical transmittance (TOT) method

NASA Astrophysics Data System (ADS)

Khan, A. J.; Swami, Kamal; Ahmed, Tanveer; Bari, A.; Shareef, Akhtar; Husain, Liaquat

2009-12-01

An improved chemical oxidation pretreatment method has been developed for the determination of elemental carbon (EC) [also known as black carbon (BC) or soot] in lake sediments, using a thermal-optical transmittance (TOT) carbon analyzer. The method employs six steps: (1) removal of carbonates by treatment with HCl; (2) removal of silicates by treatment with HF + HCl; (3) removal of any remaining carbonates by treatment with HCl; (4) removal of humic acids by treatment with NaOH; and (5) oxidation of kerogens by K 2Cr 2O 7 + H 2SO 4. A critical step of zinc chloride treatment was added; this apparently changes EC's morphology and enhances retention on quartz fiber filter, resulting in several-fold increased chemical yield. EC was determined using the TOT method with modified combustion timings. Carbon black (acetylene) and four NIST standard reference materials (SRMs) were used for quality control, and to assess the precision of the analysis. The EC recoveries from 18 carbon black samples varied from 90 to 111%, with a mean value of 99 ± 6%. The high EC recoveries confirmed the validity of the method. Char reference materials (i.e. chestnut wood and grass char) were used to determine potential contribution to EC in our measurements. The char references containing about 700 mg total organic carbon (OC) contributed ˜1.5% EC. The measured EC values from four NIST standards were 17.0 ± 0.6, 24.2 ± 3.2, 5.6, and 1.9 ± 0.1 mg g dw-1 for SRM-1648, SRM-1649a, SRM-1941b and SRM-8704, respectively. These values in SRMs were in agreement (<±4%) with the previously reported values. The method was applied to determine the EC in sediment cores from an urban lake and a remote mountain lake in the Northeastern United States. The EC concentrations in two lakes mimic the model EC emissions from the industrial revolution in United States.

Steps toward identifying a biogeochemical signal in non-equilibrium methane clumped isotope measurements

NASA Astrophysics Data System (ADS)

Douglas, P. M.; Eiler, J. M.; Sessions, A. L.; Dawson, K.; Walter Anthony, K. M.; Smith, D. A.; Lloyd, M. K.; Yanay, E.

2016-12-01

Microbially produced methane is a globally important greenhouse gas, energy source, and biological substrate. Methane clumped isotope measurements have recently been developed as a new analytical tool for understanding the source of methane in different environments. When methane forms in isotopic equilibrium clumped isotope values are determined by formation temperature, but in many cases microbial methane clumped isotope values deviate strongly from expected equilibrium values. Indeed, we observe a very wide range of clumped isotope values in microbial methane, which are likely strongly influenced by kinetic isotope effects, but thus far the biological and environmental parameters controlling this variability are not understood. We will present data from both culture experiments and natural environments to explore patterns of variability in non-equilibrium clumped isotope values on temporal and spatial scales. In methanogen batch cultures sampled at different time points along a growth curve we observe significant variability in clumped isotope values, with values decreasing from early to late exponential growth. Clumped isotope values then increase during stationary growth. This result is consistent with previous work suggesting that differences in the reversibility of methanogenesis related to metabolic rates control non-equilibrium clumped isotope values. Within single lakes in Alaska and Sweden we observe substantial variability in clumped isotope values on the order of 5‰. Lower clumped isotope values are associated with larger 2H isotopic fractionation between water and methane, which is also consistent with a kinetic isotope effect determined by the reversibility of methanogenesis. Finally, we analyzed a time-series clumped isotope compositions of methane emitted from two seeps in an Alaskan lake over several months. Temporal variability in these seeps is on the order of 2‰, which is much less than the observed spatial variability within the lake. Comparing carbon isotope fractionation between CO2 and CH4 with clumped isotope data suggests the temporal variability may result from changes in methane oxidation.

Simultaneous determination of thirteen different steroid hormones using micro UHPLC-MS/MS with on-line SPE system.

PubMed

Márta, Zoltán; Bobály, Balázs; Fekete, Jenő; Magda, Balázs; Imre, Tímea; Mészáros, Katalin Viola; Bálint, Mária; Szabó, Pál Tamás

2018-02-20

Ultratrace analysis of sample components requires excellent analytical performance in terms of limits of quantitation (LOQ). Micro UHPLC coupled to sensitive tandem mass spectrometry provides state of the art solution for such analytical problems. Using on-line SPE with column switching on a micro UHPLC-MS/MS system allowed to decrease LOQ without any complex sample preparation protocol. The presented method is capable of reaching satisfactory low LOQ values for analysis of thirteen different steroid molecules from human plasma without the most commonly used off-line SPE or compound derivatization. Steroids were determined by using two simple sample preparation methods, based on lower and higher plasma steroid concentrations. In the first method, higher analyte concentrations were directly determined after protein precipitation with methanol. The organic phase obtained from the precipitation was diluted with water and directly injected into the LC-MS system. In the second method, low steroid levels were determined by concentrating the organic phase after steroid extraction. In this case, analytes were extracted with ethyl acetate and reconstituted in 90/10 water/acetonitrile following evaporation to dryness. This step provided much lower LOQs, outperforming previously published values. The method has been validated and subsequently applied to clinical laboratory measurement. Copyright © 2017 Elsevier B.V. All rights reserved.

Determination of Major Phenolic Compounds in Echinacea spp. Raw Materials and Finished Products by High-Performance Liquid Chromatography with Ultraviolet Detection: Single-Laboratory Validation Matrix Extension

PubMed Central

Brown, Paula N.; Chan, Michael; Paley, Lori; Betz, Joseph M.

2013-01-01

A method previously validated to determine caftaric acid, chlorogenic acid, cynarin, echinacoside, and cichoric acid in echinacea raw materials has been successfully applied to dry extract and liquid tincture products in response to North American consumer needs. Single-laboratory validation was used to assess the repeatability, accuracy, selectivity, LOD, LOQ, analyte stability (ruggedness), and linearity of the method, with emphasis on finished products. Repeatability precision for each phenolic compound was between 1.04 and 5.65% RSD, with HorRat values between 0.30 and 1.39 for raw and dry extract finished products. HorRat values for tinctures were between 0.09 and 1.10. Accuracy of the method was determined through spike recovery studies. Recovery of each compound from raw material negative control (ginseng) was between 90 and 114%, while recovery from the finished product negative control (maltodextrin and magnesium stearate) was between 97 and 103%. A study was conducted to determine if cichoric acid, a major phenolic component of Echinacea purpurea (L.) Moench and E. angustifolia DC, degrades during sample preparation (extraction) and HPLC analysis. No significant degradation was observed over an extended testing period using the validated method. PMID:22165004

Determination of major phenolic compounds in Echinacea spp. raw materials and finished products by high-performance liquid chromatography with ultraviolet detection: single-laboratory validation matrix extension.

PubMed

Brown, Paula N; Chan, Michael; Paley, Lori; Betz, Joseph M

2011-01-01

A method previously validated to determine caftaric acid, chlorogenic acid, cynarin, echinacoside, and cichoric acid in echinacea raw materials has been successfully applied to dry extract and liquid tincture products in response to North American consumer needs. Single-laboratory validation was used to assess the repeatability, accuracy, selectivity, LOD, LOQ, analyte stability (ruggedness), and linearity of the method, with emphasis on finished products. Repeatability precision for each phenolic compound was between 1.04 and 5.65% RSD, with HorRat values between 0.30 and 1.39 for raw and dry extract finished products. HorRat values for tinctures were between 0.09 and 1.10. Accuracy of the method was determined through spike recovery studies. Recovery of each compound from raw material negative control (ginseng) was between 90 and 114%, while recovery from the finished product negative control (maltodextrin and magnesium stearate) was between 97 and 103%. A study was conducted to determine if cichoric acid, a major phenolic component of Echinacea purpurea (L.) Moench and E. angustifolia DC, degrades during sample preparation (extraction) and HPLC analysis. No significant degradation was observed over an extended testing period using the validated method.

Determination of combined sibship indices "gray zone" using 15 STR loci for central Bosnian human population.

PubMed

Musanovic, Jasmin; Filipovska-Musanovic, Marijana; Kovacevic, Lejla; Buljugic, Dzenisa; Dzehverovic, Mirela; Avdic, Jasna; Marjanovic, Damir

2012-05-01

In our previous population studies of Bosnia and Herzegovina human population, we have used autosomal STR, Y-STR, and X-STR loci, as well as Y-chromosome NRY biallelic markers. All obtained results were included in Bosnian referent database. In order of future development of applied population molecular genetics researches of Bosnia and Herzegovina human population, we have examined the effectiveness of 15 STR loci system in determination of sibship by using 15 STR loci and calculating different cut-off points of combined sibship indices (CSI) and distribution of sharing alleles. From the perspective of its application, it is very difficult and complicated to establish strict CSI cut-off values for determination of the doubtless sibship. High statistically significant difference between the means of CSI values and in distribution of alleles sharing in siblings and non-siblings was noticed (P < 0.0001). After constructing the "gray zone", only one false positive result was found in three CSI cut-off levels with the highest percent of determined sibship/non-sibship at the CSI = 0.067, confirming its practical benefit. Concerning the distribution of sharing alleles, it is recommended as an informative estimator for its usage within Bosnia and Herzegovina human population.

The availability of prior ECGs improves paramedic accuracy in recognizing ST-segment elevation myocardial infarction.

PubMed

O'Donnell, Daniel; Mancera, Mike; Savory, Eric; Christopher, Shawn; Schaffer, Jason; Roumpf, Steve

2015-01-01

Early and accurate identification of ST-elevation myocardial infarction (STEMI) by prehospital providers has been shown to significantly improve door to balloon times and improve patient outcomes. Previous studies have shown that paramedic accuracy in reading 12 lead ECGs can range from 86% to 94%. However, recent studies have demonstrated that accuracy diminishes for the more uncommon STEMI presentations (e.g. lateral). Unlike hospital physicians, paramedics rarely have the ability to review previous ECGs for comparison. Whether or not a prior ECG can improve paramedic accuracy is not known. The availability of prior ECGs improves paramedic accuracy in ECG interpretation. 130 paramedics were given a single clinical scenario. Then they were randomly assigned 12 computerized prehospital ECGs, 6 with and 6 without an accompanying prior ECG. All ECGs were obtained from a local STEMI registry. For each ECG paramedics were asked to determine whether or not there was a STEMI and to rate their confidence in their interpretation. To determine if the old ECGs improved accuracy we used a mixed effects logistic regression model to calculate p-values between the control and intervention. The addition of a previous ECG improved the accuracy of identifying STEMIs from 75.5% to 80.5% (p=0.015). A previous ECG also increased paramedic confidence in their interpretation (p=0.011). The availability of previous ECGs improves paramedic accuracy and enhances their confidence in interpreting STEMIs. Further studies are needed to evaluate this impact in a clinical setting. Copyright © 2015 Elsevier Inc. All rights reserved.

Methanogenic degradation kinetics of phenolic compounds in aquifer-derived microcosms

USGS Publications Warehouse

Godsy, E.M.; Goerlitz, D.F.; Grbic-Galic, D.

1992-01-01

In this segment of a larger multidisciplinary study of the movement and fate of creosote derived compounds in a sand-and-gravel aquifer, we present evidence that the methanogenic degradation of the major biodegradable phenolic compounds and concomitant microbial growth in batch microcosms derived from contaminated aquifer material can be described using Monod kinetics. Substrate depletion and bacterial growth curves were fitted to the Monod equations using nonlinear regression analysis. The method of Marquardt was used for the determination of parameter values that best fit the experimental data by minimizing the residual sum of squares. The Monod kinetic constants (??max, Ks, Y, and kd) that describe phenol, 2-, 3-, and 4-methylphenol degradation and concomitant microbial growth were determined under conditions that were substantially different from those previously reported for microcosms cultured from sewage sludge. The Ks values obtained in this study are approximately two orders of magnitude lower than values obtained for the anaerobic degradation of phenol in digesting sewage sludge, indicating that the aquifer microorganisms have developed enzyme systems that are adapted to low nutrient conditions. The values for kd are much less than ??max, and can be neglected in the microcosms. The extremely low Y values, approximately 3 orders of magnitude lower than for the sewage sludge derived cultures, and the very low numbers of microorganisms in the aquifer derived microcosms suggest that these organisms use some unique strategies to survive in the subsurface environment. ?? 1992 Kluwer Academic Publishers.

Relation between D/H ratios and 18O /16O ratios in cellulose from linen and maize - Implications for paleoclimatology and for sindonology

NASA Astrophysics Data System (ADS)

DeNiro, Michael J.; Sternberg, Leonel D.; Marino, Bruno D.; Druzik, James R.

1988-09-01

The 18O /16O ratios of cellulose and the D/H ratios of cellulose nitrate were determined for linen, a textile produced from the fibers of the flax plant Linum usitatissimum, and for maize ( Zea mays) from a variety of geographic locations in Europe, the Middle East, and North and South America. The regression lines of δD values on δ 18O values had slopes of 5.4 and 5.8 for the two species. Statistical analysis of results reported in the only other study in which samples of a single species (the silver fir Abies pindrow) that grew under a variety of climatic conditions were analyzed yielded slopes of ~6 when δD values of cellulose nitrate were regressed on δ 18O values of cellulose. The occurrence of this previously unrecognized relationship in three species suggests it may obtain in other plants as well. Determining the basis for this relationship, which is not possible given current understanding of fractionation of the isotopes of oxygen and hydrogen by plants, should lead to increased understanding of how D/H and 18O /16O ratios in cellulose isolated from fossil plants are related to paleoclimates. The separation of most linen samples from Europe from those originating in the Middle East when δD values are plotted against δ 18O values suggests it may be possible to use the isotope ratios of cellulose prepared from the Shroud of Turin to resolve the controversy concerning its geographic origin.

Precise determination of cosmogenic Ne in CREU-1 quartz standard, using the Helix-MC Plus mass spectrometer

NASA Astrophysics Data System (ADS)

Hamilton, D.; Honda, M.; Zhang, X.; Phillips, D.; Matchan, E.

2017-12-01

The Helix-MC Plus multi-collector noble gas mass spectrometer at the Australian National University is uniquely equipped with three high mass resolution collectors on H2, Axial and L2 positions. Their mass resolution and mass resolving power are as high as 1,800 and 8,000, respectively. The Helix-MC Plus can totally separate 20Ne+ from 40Ar++ isobaric interference and also partially separate 21Ne+ from 20NeH+ and 22Ne+ from 12C16O2++. By adjusting collector positions, we are able to measure interference-free Ne isotope intensities and have re-determined the 21Ne abundance in air [1]. Analyses by Honda et al. [1] demonstrated that 20Ne1H contributes approximately 2% to previously determined atmospheric 21Ne values [2], and a new atmospheric 21Ne/20Ne ratio of 0.002906 was calculated. Using the Helix-MC Plus mass spectrometer, we measured Ne abundances in the CREU-1 quartz standard [3] and determined cosmogenic concentrations by subtraction of atmospheric Ne with the new atmospheric 21Ne/20Ne value. The average concentration of cosmogenic 21Ne determined from four repeated analyses is 338 ± 12 × 106 atom/g (2σ). This compares with the average concentration of 348 ± 10 × 106 atom/g (2σ) from 45 analyses determined by several laboratories [3], where Ne isotope analyses were undertaken by conventional low resolution mass spectrometers and atmospheric Ne was subtracted using the conventional atmospheric 21Ne/20Ne [2]. On this basis, for a sample with abundant cosmogenic Ne, like CREU-1 quartz, previously measured by low mass resolution mass spectrometers are likely valid and their geological implications are unaffected. However, for low 21Ne concentration samples, combining new generation of mass spectrometers as well as the new atmospheric ratio may have significance for cosmogenic 21Ne surface exposure dating. References: [1] Honda M., et. al., International Journal of Mass Spectrometry, 387, 1 (2015). [2] Eberhardt P., et. al., Zeitschrift fur Naturforschung, 20a, 623 (1965). [3] Vermeesch P., et. al., Quaternary Geochronology, 26, 20 (2015).

A mechanism for value-sensitive decision-making.

PubMed

Pais, Darren; Hogan, Patrick M; Schlegel, Thomas; Franks, Nigel R; Leonard, Naomi E; Marshall, James A R

2013-01-01

We present a dynamical systems analysis of a decision-making mechanism inspired by collective choice in house-hunting honeybee swarms, revealing the crucial role of cross-inhibitory 'stop-signalling' in improving the decision-making capabilities. We show that strength of cross-inhibition is a decision-parameter influencing how decisions depend both on the difference in value and on the mean value of the alternatives; this is in contrast to many previous mechanistic models of decision-making, which are typically sensitive to decision accuracy rather than the value of the option chosen. The strength of cross-inhibition determines when deadlock over similarly valued alternatives is maintained or broken, as a function of the mean value; thus, changes in cross-inhibition strength allow adaptive time-dependent decision-making strategies. Cross-inhibition also tunes the minimum difference between alternatives required for reliable discrimination, in a manner similar to Weber's law of just-noticeable difference. Finally, cross-inhibition tunes the speed-accuracy trade-off realised when differences in the values of the alternatives are sufficiently large to matter. We propose that the model, and the significant role of the values of the alternatives, may describe other decision-making systems, including intracellular regulatory circuits, and simple neural circuits, and may provide guidance in the design of decision-making algorithms for artificial systems, particularly those functioning without centralised control.

Model of the best-of-N nest-site selection process in honeybees.

PubMed

Reina, Andreagiovanni; Marshall, James A R; Trianni, Vito; Bose, Thomas

2017-05-01

The ability of a honeybee swarm to select the best nest site plays a fundamental role in determining the future colony's fitness. To date, the nest-site selection process has mostly been modeled and theoretically analyzed for the case of binary decisions. However, when the number of alternative nests is larger than two, the decision-process dynamics qualitatively change. In this work, we extend previous analyses of a value-sensitive decision-making mechanism to a decision process among N nests. First, we present the decision-making dynamics in the symmetric case of N equal-quality nests. Then, we generalize our findings to a best-of-N decision scenario with one superior nest and N-1 inferior nests, previously studied empirically in bees and ants. Whereas previous binary models highlighted the crucial role of inhibitory stop-signaling, the key parameter in our new analysis is the relative time invested by swarm members in individual discovery and in signaling behaviors. Our new analysis reveals conflicting pressures on this ratio in symmetric and best-of-N decisions, which could be solved through a time-dependent signaling strategy. Additionally, our analysis suggests how ecological factors determining the density of suitable nest sites may have led to selective pressures for an optimal stable signaling ratio.

Model of the best-of-N nest-site selection process in honeybees

NASA Astrophysics Data System (ADS)

Reina, Andreagiovanni; Marshall, James A. R.; Trianni, Vito; Bose, Thomas

2017-05-01

The ability of a honeybee swarm to select the best nest site plays a fundamental role in determining the future colony's fitness. To date, the nest-site selection process has mostly been modeled and theoretically analyzed for the case of binary decisions. However, when the number of alternative nests is larger than two, the decision-process dynamics qualitatively change. In this work, we extend previous analyses of a value-sensitive decision-making mechanism to a decision process among N nests. First, we present the decision-making dynamics in the symmetric case of N equal-quality nests. Then, we generalize our findings to a best-of-N decision scenario with one superior nest and N -1 inferior nests, previously studied empirically in bees and ants. Whereas previous binary models highlighted the crucial role of inhibitory stop-signaling, the key parameter in our new analysis is the relative time invested by swarm members in individual discovery and in signaling behaviors. Our new analysis reveals conflicting pressures on this ratio in symmetric and best-of-N decisions, which could be solved through a time-dependent signaling strategy. Additionally, our analysis suggests how ecological factors determining the density of suitable nest sites may have led to selective pressures for an optimal stable signaling ratio.

Cost-utility analysis of a multidisciplinary strategy to manage osteoarthritis of the knee: economic evaluation of a cluster randomized controlled trial study.

PubMed

Marra, Carlo A; Grubisic, Maja; Cibere, Jolanda; Grindrod, Kelly A; Woolcott, John C; Gastonguay, Louise; Esdaile, John M

2014-06-01

To determine if a pharmacist-initiated multidisciplinary strategy provides value for money compared to usual care in participants with previously undiagnosed knee osteoarthritis. Pharmacies were randomly allocated to provide either 1) usual care and a pamphlet or 2) intervention care, which consisted of education, pain medication management by a pharmacist, physiotherapy-guided exercise, and communication with the primary care physician. Costs and quality-adjusted life-years (QALYs) were determined for patients assigned to each treatment and incremental cost-effectiveness ratios (ICERs) were determined. From the Ministry of Health perspective, the average patient in the intervention group generated slightly higher costs compared with usual care. Similar findings were obtained when using the societal perspective. The intervention resulted in ICERs of $232 (95% confidence interval [95% CI] -1,530, 2,154) per QALY gained from the Ministry of Health perspective and $14,395 (95% CI 7,826, 23,132) per QALY gained from the societal perspective, compared with usual care. A pharmacist-initiated, multidisciplinary program was good value for money from both the societal and Ministry of Health perspectives. Copyright © 2014 by the American College of Rheumatology.

Physiological parameter values in greyhounds before and after high-intensity exercise.

PubMed

Pellegrino, Francisco Javier; Risso, Analía; Vaquero, Pablo G; Corrada, Yanina A

2018-01-01

Dog sports competitions have greatly expanded. The availability of reference values for each type of activity could help assess fitness accurately. Heart rate (HR), blood lactate (BL) and rectal temperature (RT) are relevant physiological parameters to determine the dogs response to effort. Previous studies in greyhounds have reported the effect of high-intensity exercise on many physiological parameters immediately after completing different racing distances and recovery times. However, there are no studies concerning physiological changes over shorter racing distances. We therefore assessed the effect of sprint exercise on HR, BL and RT in nine greyhounds performing sprint exercise over a 100-m distance chasing a lure. After the exercise, dogs underwent a passive 10-min recovery phase. Before the exercise, immediately after it and at 5 and 10 min during recovery, HR and RT were assessed and blood samples were collected for BL determination. HR, BL and RT values increased significantly after the exercise (P<0.01). Whereas HR returned to pre-exercise values at 10 min during the recovery phase (P>0.1), BL concentration and RT remained increased (P<0.01). The abrupt increase in HR, BL and RT values observed immediately after the exercise indicates the high intensity of the effort performed. Similarly, BL concentration after the exercise exceeded the 4 mmol/L lactate threshold, suggesting a predominant anaerobic metabolism during effort. Although HR returned to pre-exercise values 10 min after the exercise, a more extensive recovery phase would be necessary for a total return to resting values, particularly for BL and RT. In greyhounds subjected to high-intensity exercise, HR, BL and RT were reliable physiological parameters to accurately assess the physiological response to effort. The use of sprint exercises over short racing distances could be useful for appropriately monitoring fitness in sporting dogs.

The Development of Neuroendocrine Disturbances over Time: Longitudinal Findings in Patients after Traumatic Brain Injury and Subarachnoid Hemorrhage

PubMed Central

Kopczak, Anna; Krewer, Carmen; Schneider, Manfred; Kreitschmann-Andermahr, Ilonka; Schneider, Harald Jörn; Stalla, Günter Karl

2015-01-01

Previous reports suggest that neuroendocrine disturbances in patients with traumatic brain injury (TBI) or aneurysmal subarachnoid hemorrhage (SAH) may still develop or resolve months or even years after the trauma. We investigated a cohort of n = 168 patients (81 patients after TBI and 87 patients after SAH) in whom hormone levels had been determined at various time points to assess the course and pattern of hormonal insufficiencies. Data were analyzed using three different criteria: (1) patients with lowered basal laboratory values; (2) patients with lowered basal laboratory values or the need for hormone replacement therapy; (3) diagnosis of the treating physician. The first hormonal assessment after a median time of three months after the injury showed lowered hormone laboratory test results in 35% of cases. Lowered testosterone (23.1% of male patients), lowered estradiol (14.3% of female patients) and lowered insulin-like growth factor I (IGF-I) values (12.1%) were most common. Using Criterion 2, a higher prevalence rate of 55.6% of cases was determined, which correlated well with the prevalence rate of 54% of cases using the physicians’ diagnosis as the criterion. Intraindividual changes (new onset insufficiency or recovery) were predominantly observed for the somatotropic axis (12.5%), the gonadotropic axis in women (11.1%) and the corticotropic axis (10.6%). Patients after TBI showed more often lowered IGF-I values at first testing, but normal values at follow-up (p < 0.0004). In general, most patients remained stable. Stable hormone results at follow-up were obtained in 78% (free thyroxine (fT4) values) to 94.6% (prolactin values). PMID:26703585

Evaluating Uncertainties in Coronal Electron Temperature and Radial Speed Measurements Using a Simulation of the Bastille Day Eruption

NASA Astrophysics Data System (ADS)

Reginald, Nelson; St. Cyr, Orville; Davila, Joseph; Rastaetter, Lutz; Török, Tibor

2018-05-01

Obtaining reliable measurements of plasma parameters in the Sun's corona remains an important challenge for solar physics. We previously presented a method for producing maps of electron temperature and speed of the solar corona using K-corona brightness measurements made through four color filters in visible light, which were tested for their accuracies using models of a structured, yet steady corona. In this article we test the same technique using a coronal model of the Bastille Day (14 July 2000) coronal mass ejection, which also contains quiet areas and streamers. We use the coronal electron density, temperature, and flow speed contained in the model to determine two K-coronal brightness ratios at (410.3, 390.0 nm) and (423.3, 398.7 nm) along more than 4000 lines of sight. Now assuming that for real observations, the only information we have for each line of sight are these two K-coronal brightness ratios, we use a spherically symmetric model of the corona that contains no structures to interpret these two ratios for electron temperature and speed. We then compare the interpreted (or measured) values for each line of sight with the true values from the model at the plane of the sky for that same line of sight to determine the magnitude of the errors. We show that the measured values closely match the true values in quiet areas. However, in locations of coronal structures, the measured values are predictably underestimated or overestimated compared to the true values, but can nevertheless be used to determine the positions of the structures with respect to the plane of the sky, in front or behind. Based on our results, we propose that future white-light coronagraphs be equipped to image the corona using four color filters in order to routinely create coronal maps of electron density, temperature, and flow speed.

Q Value of the Superallowed Decay of {sup 46}V and Its Influence on V{sub ud} and the Unitarity of the Cabibbo-Kobayashi-Maskawa Matrix

DOE Office of Scientific and Technical Information (OSTI.GOV)

Savard, G.; Department of Physics, University of Chicago, Chicago, Illinois 60637; Buchinger, F.

2005-09-02

The masses of the radioactive nuclei {sup 46}V and its decay daughter {sup 46}Ti have been measured with the Canadian Penning Trap on-line Penning trap mass spectrometer to a precision of 1x10{sup -8}. A Q{sub EC} value of 7052.90(40) keV for the superallowed beta decay of {sup 46}V is obtained from the difference of these two masses. With this precise Q value, the Ft value for this decay is determined with improved precision. An investigation of an earlier Q-value measurement for {sup 46}V uncovers a set of 7 measurements that cannot be reconciled with modern data and affects previous evaluationsmore » of V{sub ud} from superallowed Fermi decays. A new evaluation, adding our new data and removing the discredited subset, yields new values for G{sub V} and V{sub ud}. When combined with recent results for V{sub us}, this yields modified constraints for the unitarity of the Cabibbo-Kobayashi-Maskawa matrix and other extensions of the standard model.« less

Sweat osmolarity shows intra-animal regional variation in the horse.

PubMed

Potts, Samantha; Thatcher, Rhys; Jones, Arwel W; Warren, Lori K; Tenbroeck, Saundra H; Nottage, Florence; McEwan, Neil R

2015-10-01

Sweating is important in regulating body temperature but can be a source of loss of both fluids and electrolytes. Although the process has been studied in horses, the variation in sweat osmolarity across the body has not. This work describes an investigation to determine if there is regional variation in the osmolarity of sweat across different anatomical regions of the horse. Ten horses were used in the study and were animals either stabled for riding lessons or had livery on-site. Sweat samples were collected from five regions on each horse following exercise and the osmolarity measurements were made using an Osmomat 030 (Gonotec, Berlin, Germany). Values were analysed by paired t-tests and analysis of variance. Samples from the back and ears had statistically (P < 0.05) lower osmolarity values than those seen for the neck and forelimb, with thigh values intermediate between the other two sets of values. Previous studies have used osmolarity values based on the sweat collected from the horse's back. The current work demonstrates that these values are probably an underestimation of electrolyte loss, which may have implications for the composition and administration of rehydration compounds. © 2015 ESVD and ACVD.

High-precision branching-ratio measurement for the superallowed β+ emitter 74Rb

NASA Astrophysics Data System (ADS)

Dunlop, R.; Ball, G. C.; Leslie, J. R.; Svensson, C. E.; Towner, I. S.; Andreoiu, C.; Chagnon-Lessard, S.; Chester, A.; Cross, D. S.; Finlay, P.; Garnsworthy, A. B.; Garrett, P. E.; Glister, J.; Hackman, G.; Hadinia, B.; Leach, K. G.; Rand, E. T.; Starosta, K.; Tardiff, E. R.; Triambak, S.; Williams, S. J.; Wong, J.; Yates, S. W.; Zganjar, E. F.

2013-10-01

A high-precision branching-ratio measurement for the superallowed β+ decay of 74Rb was performed at the TRIUMF Isotope Separator and Accelerator (ISAC) radioactive ion-beam facility. The scintillating electron-positron tagging array (SCEPTAR), composed of 10 thin plastic scintillators, was used to detect the emitted β particles; the 8π spectrometer, an array of 20 Compton-suppressed HPGe detectors, was used for detecting γ rays that were emitted following Gamow-Teller and nonanalog Fermi β+ decays of 74Rb; and the Pentagonal Array of Conversion Electron Spectrometers (PACES), an array of 5 Si(Li) detectors, was employed for measuring β-delayed conversion electrons. Twenty-three excited states were identified in 74Kr following 8.241(4)×108 detected 74Rb β decays. A total of 58 γ-ray and electron transitions were placed in the decay scheme, allowing the superallowed branching ratio to be determined as B0=99.545(31)%. Combined with previous half-life and Q-value measurements, the superallowed branching ratio measured in this work leads to a superallowed ft value of 3082.8(65) s. Comparisons between this superallowed ft value and the world-average-corrected Ft¯ value, as well as the nonanalog Fermi branching ratios determined in this work, provide guidance for theoretical models of the isospin-symmetry-breaking corrections in this mass region.

Radiolysis of water at elevated temperatures—III. Simulation of radiolytic products at 25 and 250°C under the irradiation with γ-rays and fast neutrons

NASA Astrophysics Data System (ADS)

Sunaryo, Geni R.; Katsumura, Yosuke; Ishigure, Kenkichi

1995-05-01

The G-values of water decomposition products under the irradiations with γ-rays and fast neutrons up to 250°C have been determined in previous studies. In order to clarify the characteristics of the determined G-values, computer simulations under the simplified conditions in nuclear reactors have been carried out. The recent G-values for γ-radiolysis reported by Elliot, Chenier and Quellete [(1990) Can. J. Chem.68, 712; (1993) J. Chem. Soc. Faraday Trans.89, 1193], Kent and Sims [(1992) Water Chemistry of Nuclear Reactor Systems 6, p. 153. BNES, London], and Sunaryo, Katsumura, Shirai, Hiroishi and Ishigure [(1994) Radiat. Phys. Chem.44, 273] and Sunaryo, Katsumura, Hiroishi and Ishigure [(1995) Radiat. Phys. Chem.45, 131] are almost equivalent from the point of simulations. On the contrary, G-values for fast neutron radiolysis give a significant influence to the result, which arises from the higher molecular yields and smaller radical yields of water decomposition in fast neutron radiolysis, and it has been revealed that the dose evaluation in the reactor is inevitably important. In addition, it was pointed out by the simulations that reverse reactions for H 2+ .OH→ .H+H 2O and e aq-+H +→ .H, be neglected at room temperature, become important at higher temperatures.

Determination of the molecular complexation constant between alprostadil and alpha-cyclodextrin by conductometry: implications for a freeze-dried formulation.

PubMed

Sheehy, Philip M; Ramstad, Tore

2005-10-04

The binding constant between alprostadil (PGE1) and alpha-cyclodextrin (alpha-CD) was determined at four temperatures using conductance measurements. Alpha-cyclodextrin is an excipient material in Caverject dual chamber syringe (DCS) that was added to enhance stability. The binding constant was used to calculate the amount of PGE1 free upon reconstitution and injection, since only the free drug is clinically active. The conductivity measurement is based on a decrease in specific conductance as alprostadil is titrated with alpha-CD. The change in conductivity was plotted versus free ligand concentration (alpha-CD) to generate a binding curve. As the value of the binding constant proved to be dependent on substrate concentration, it is really a pseudo binding constant. A value of 742+/-60 M(-1) was obtained for a 0.5 mM solution of alprostadil at 27 degrees C and a value of 550+/-52 M(-1) at 37 degrees C. These results compare favorably to values previously obtained by NMR and capillary electrophoresis. Calculation of the fraction PGE1 free upon reconstitution and injection show it to approach the desired outcome of one. Hence, the amount of drug delivered by Caverject DCS is nominally equivalent to that delivered by Caverject S. Po., a predecessor product that contains no alpha-cyclodextrin.

Validation of a portable, waterproof blood pH analyser for elasmobranchs.

PubMed

Talwar, Brendan; Bouyoucos, Ian A; Shipley, Oliver; Rummer, Jodie L; Mandelman, John W; Brooks, Edward J; Grubbs, R Dean

2017-01-01

Quantifying changes in blood chemistry in elasmobranchs can provide insights into the physiological insults caused by anthropogenic stress, and can ultimately inform conservation and management strategies. Current methods for analysing elasmobranch blood chemistry in the field are often costly and logistically challenging. We compared blood pH values measured using a portable, waterproof pH meter (Hanna Instruments HI 99161) with blood pH values measured by an i-STAT system (CG4+ cartridges), which was previously validated for teleost and elasmobranch fishes, to gauge the accuracy of the pH meter in determining whole blood pH for the Cuban dogfish ( Squalus cubensis ) and lemon shark ( Negaprion brevirostris ). There was a significant linear relationship between values derived via the pH meter and the i-STAT for both species across a wide range of pH values and temperatures (Cuban dogfish: 6.8-7.1 pH 24-30°C; lemon sharks: 7.0-7.45 pH 25-31°C). The relative error in the pH meter's measurements was ~±2.7%. Using this device with appropriate correction factors and consideration of calibration temperatures can result in both a rapid and accurate assessment of whole blood pH, at least for the two elasmobranch species examined here. Additional species should be examined in the future across a wide range of temperatures to determine whether correction factors are universal.

Associated with aerospace vehicles development of methodologies for the estimation of thermal properties

NASA Technical Reports Server (NTRS)

Scott, Elaine P.

1994-01-01

Thermal stress analyses are an important aspect in the development of aerospace vehicles at NASA-LaRC. These analyses require knowledge of the temperature distributions within the vehicle structures which consequently necessitates the need for accurate thermal property data. The overall goal of this ongoing research effort is to develop methodologies for the estimation of the thermal property data needed to describe the temperature responses of these complex structures. The research strategy undertaken utilizes a building block approach. The idea here is to first focus on the development of property estimation methodologies for relatively simple conditions, such as isotropic materials at constant temperatures, and then systematically modify the technique for the analysis of more and more complex systems, such as anisotropic multi-component systems. The estimation methodology utilized is a statistically based method which incorporates experimental data and a mathematical model of the system. Several aspects of this overall research effort were investigated during the time of the ASEE summer program. One important aspect involved the calibration of the estimation procedure for the estimation of the thermal properties through the thickness of a standard material. Transient experiments were conducted using a Pyrex standard at various temperatures, and then the thermal properties (thermal conductivity and volumetric heat capacity) were estimated at each temperature. Confidence regions for the estimated values were also determined. These results were then compared to documented values. Another set of experimental tests were conducted on carbon composite samples at different temperatures. Again, the thermal properties were estimated for each temperature, and the results were compared with values obtained using another technique. In both sets of experiments, a 10-15 percent off-set between the estimated values and the previously determined values was found. Another effort was related to the development of the experimental techniques. Initial experiments required a resistance heater placed between two samples. The design was modified such that the heater was placed on the surface of only one sample, as would be necessary in the analysis of built up structures. Experiments using the modified technique were conducted on the composite sample used previously at different temperatures. The results were within 5 percent of those found using two samples. Finally, an initial heat transfer analysis, including conduction, convection and radiation components, was completed on a titanium sandwich structural sample. Experiments utilizing this sample are currently being designed and will be used to first estimate the material's effective thermal conductivity and later to determine the properties associated with each individual heat transfer component.

Black Carbon Emissions from In-use Ships: Results from CalNex 2010

NASA Astrophysics Data System (ADS)

Buffaloe, Gina Marise

Black carbon (BC) mass emission factors (EFBC; g-BC (kg-fuel)--1) from a variety of ocean going vessels have been determined from measurements of BC and CO2 concentrations in ship plumes intercepted by the R/V Atlantis during the 2010 California Nexus (CalNex) campaign. The ships encountered were all operating within 24 nautical miles of the California coast and were utilizing relatively low sulphur fuels. Black carbon concentrations within the plumes, from which EFBC values are determined, were measured using four independent instruments: a photoacoustic spectrometer and a particle soot absorption photometer, which measure light absorption, and a single particle soot photometer and soot particle aerosol mass spectrometer, which measure the mass concentration of refractory BC directly. The measured EFBC have been divided into vessel type categories and engine type categories, from which averages have been determined. The geometric average EFBC, determined from over 71 vessels and 135 plumes encountered, was 0.31 g-BC (kg-fuel)--1. The most frequent engine type encountered was the slow speed diesel (SSD), and the most frequent SSD vessel type was the cargo ship sub-category. Average and median EF BC values from these two categories are compared to previous observations from the Texas Air Quality Study (TexAQS) in 2006, in which the ships encountered were predominately operating high sulphur fuels. There is some indication that the EFBC values for SSD vessels during CalNex were lower than during TexAQS, although ship-to-ship variability in these data sets makes it difficult to draw firm conclusions about the influence of fuel quality on EFBC.

Correlation between Volume of Apical Periodontitis Determined by Cone-beam Computed Tomography Analysis and Endotoxin Levels Found in Primary Root Canal Infection.

PubMed

Cardoso, Flávia G R; Ferreira, Nádia S; Martinho, Frederico C; Nascimento, Gustavo G; Manhães, Luiz R C; Rocco, Marco A; Carvalho, Cláudio A T; Valera, Marcia C

2015-07-01

This clinical study was conducted to correlate the levels of endotoxins and bacterial counts found in primary endodontic infection with the volume of periapical bone destruction determined by cone-beam computed tomography (CBCT) analysis. Moreover, the levels of bacteria and endotoxins were correlated with the development of clinical features. Twenty-four root canals with primary endodontic disease and apical periodontitis were selected. Clinical features such as pain on palpation, pain on percussion, and previous episode of pain were recorded. The volume (cubic millimeters) of periapical bone destruction was determined by CBCT analysis. Endotoxins and bacterial samplings were collected by using sterile/apyrogenic paper points. Endotoxins were quantified by using limulus amebocyte lysate assay (KQCL test), and bacterial count (colony-forming units [CFU]/mL) was determined by using anaerobic culture techniques. Data were analyzed by Pearson correlation and multiple logistic regression (P < .05). Endotoxins and bacteria were detected in 100% of the root canal samples (24 of 24), with median values of 10.92 endotoxin units (EU)/mL (1.75-128 EU/mL) and 7.5 × 10(5) CFU/mL (3.20 × 10(5)-8.16 × 10(6) CFU/mL), respectively. The median volume of bone destruction determined by CBCT analysis was 100 mm(3) (10-450 mm(3)). The multiple regression analysis revealed a positive correlation between higher levels of endotoxins present in root canal infection and larger volume of bone destruction (P < .05). Moreover, higher levels of endotoxins were also correlated with the presence of previous pain (P < .05). Our findings revealed that the levels of endotoxins found in root canal infection are related to the volume of periapical bone destruction determined by CBCT analysis. Moreover, the levels of endotoxin are related to the presence of previous pain. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Reddening and age for 13 southern Galactic open clusters determined from integrated spectra

NASA Astrophysics Data System (ADS)

Ahumada, A. V.; Clariá, J. J.; Bica, E.; Dutra, C. M.; Torres, M. C.

2001-10-01

In this study we present flux-calibrated integrated spectra in the range 3800-6800 Å for 13 concentrated open clusters with Galactic longitudes between 219deg and 316deg, nine of which have not been previously studied. Using the equivalent widths of the Balmer lines and comparing the cluster spectra with template spectra of Magellanic Clouds and Galactic star clusters with known parameters, we derive both foreground interstellar reddening values and age. For nine clusters these two parameters have been determined for the first time, while for the rest of the sample the results show good agreement with previous studies. The present analysis indicates four very young (Hogg 11, NGC 5606, vdB-RN 80 and Pismis 17), seven moderately young (ESO 429-SC13, Hogg 3, Hogg 12, Haffner 7, BH 87, NGC 2368 and Bochum 12) and two intermediate-age (Berkeley 75 and NGC 2635) open clusters. The derived foreground interstellar reddening values are in the range 0.00 <= E(B-V) <= 0.38. The age and reddening distributions of the present sample of relatively faint open clusters match those of open clusters with known parameters in a 90deg sector centered at l = 270deg. Based on observations made at Complejo Astronómico El Leoncito, which is operated under agreement between the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina and the National Universities of La Plata, Córdoba and San Juan, Argentina.

Predicting and analyzing the trend of traffic accidents deaths in Iran in 2014 and 2015.

PubMed

Mehmandar, Mohammadreza; Soori, Hamid; Mehrabi, Yadolah

2016-01-01

Predicting the trend in traffic accidents deaths and its analysis can be a useful tool for planning and policy-making, conducting interventions appropriate with death trend, and taking the necessary actions required for controlling and preventing future occurrences. Predicting and analyzing the trend of traffic accidents deaths in Iran in 2014 and 2015. It was a cross-sectional study. All the information related to fatal traffic accidents available in the database of Iran Legal Medicine Organization from 2004 to the end of 2013 were used to determine the change points (multi-variable time series analysis). Using autoregressive integrated moving average (ARIMA) model, traffic accidents death rates were predicted for 2014 and 2015, and a comparison was made between this rate and the predicted value in order to determine the efficiency of the model. From the results, the actual death rate in 2014 was almost similar to that recorded for this year, while in 2015 there was a decrease compared with the previous year (2014) for all the months. A maximum value of 41% was also predicted for the months of January and February, 2015. From the prediction and analysis of the death trends, proper application and continuous use of the intervention conducted in the previous years for road safety improvement, motor vehicle safety improvement, particularly training and culture-fostering interventions, as well as approval and execution of deterrent regulations for changing the organizational behaviors, can significantly decrease the loss caused by traffic accidents.

New determination of the gravitational constant G with time-of-swing method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tu Liangcheng; Li Qing; Wang Qinglan

A new determination of the Newtonian gravitational constant G is presented by using a torsion pendulum with the time-of-swing method. Compared with our previous measurement with the same method, several improvements greatly reduced the uncertainties as follows: (i) two stainless steel spheres with more homogeneous density are used as the source masses instead of the cylinders used in the previous experiment, and the offset of the mass center from the geometric center is measured and found to be much smaller than that of the cylinders; (ii) a rectangular glass block is used as the main body of the pendulum, whichmore » has fewer vibration modes and hence improves the stability of the period and reduces the uncertainty of the moment of inertia; (iii) both the pendulum and source masses are placed in the same vacuum chamber to reduce the error of measuring the relative positions; (iv) changing the configurations between the ''near'' and ''far'' positions is remotely operated by using a stepper motor to lower the environmental disturbances; and (v) the anelastic effect of the torsion fiber is first measured directly by using two disk pendulums with the help of a high-Q quartz fiber. We have performed two independent G measurements, and the two G values differ by only 9 ppm. The combined value of G is (6.673 49{+-}0.000 18)x10{sup -11} m{sup 3} kg{sup -1} s{sup -2} with a relative uncertainty of 26 ppm.« less

Solar-System Tests of Gravitational Theories

NASA Technical Reports Server (NTRS)

Shapiro, Irwin

1997-01-01

We are engaged in testing gravitational theory by means of observations of objects in the solar system. These tests include an examination of the Principle Of Equivalence (POE), the Shapiro delay, the advances of planetary perihelia, the possibility of a secular variation G in the "gravitational constant" G, and the rate of the de Sitter (geodetic) precession of the Earth-Moon system. These results are consistent with our preliminary results focusing on the contribution of Lunar Laser Ranging (LLR), which were presented at the seventh Marcel Grossmann meeting on general relativity. The largest improvement over previous results comes in the uncertainty for (eta): a factor of five better than our previous value. This improvement reflects the increasing strength of the LLR data. A similar analysis presented at the same meeting by a group at the Jet Propulsion Laboratory gave a similar result for (eta). Our value for (beta) represents our first such result determined simultaneously with the solar quadrupole moment from the dynamical data set. These results are being prepared for publication. We have shown how positions determined from different planetary ephemerides can be compared and how the combination of VLBI and pulse timing information can yield a direct tie between planetary and radio frames. We have continued to include new data in our analysis as they became available. Finally, we have made improvement in our analysis software (PEP) and ported it to a network of modern workstations from its former home on a "mainframe" computer.

Potential Use of {sup 18}F-fluorodeoxyglucose Positron Emission Tomography–Based Quantitative Imaging Features for Guiding Dose Escalation in Stage III Non-Small Cell Lung Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fried, David V., E-mail: dvfried@mdanderson.org; Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, Texas; Mawlawi, Osama

2016-02-01

Purpose: To determine whether previously identified quantitative image features (QIFs) based on {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG-PET) (co-occurrence matrix energy and solidity) are able to isolate subgroups of patients who would receive a benefit or detriment from dose escalation in terms of overall survival (OS) or progression-free survival (PFS). Methods and Materials: Subgroups of a previously analyzed 225 patient cohort were generated with the use of 5-percentile increment cutoff values of disease solidity and primary tumor co-occurrence matrix energy. The subgroups were analyzed with a log-rank test to determine whether there was a difference in OS and PFS betweenmore » patients treated with 60 to 70 Gy and those receiving 74 Gy. Results: In the entire patient cohort, there was no statistical difference in terms of OS or PFS between patients receiving 74 Gy and those receiving 60 to 70 Gy. It was qualitatively observed that as disease solidity and primary co-occurrence matrix energy increased, patients receiving 74 Gy had an improved OS and PFS compared with those receiving 60 to 70 Gy. The opposite trend (detriment of receiving 74 Gy) was also observed regarding low values of disease solidity and primary co-occurrence matrix energy. Conclusions: FDG-PET–based QIFs were found to be capable of isolating subgroups of patients who received a benefit or detriment from dose escalation.« less

Modeling the lag period and exponential growth of Listeria monocytogenes under conditions of fluctuating temperature and water activity values.

PubMed

Muñoz-Cuevas, Marina; Fernández, Pablo S; George, Susan; Pin, Carmen

2010-05-01

The dynamic model for the growth of a bacterial population described by Baranyi and Roberts (J. Baranyi and T. A. Roberts, Int. J. Food Microbiol. 23:277-294, 1994) was applied to model the lag period and exponential growth of Listeria monocytogenes under conditions of fluctuating temperature and water activity (a(w)) values. To model the duration of the lag phase, the dependence of the parameter h(0), which quantifies the amount of work done during the lag period, on the previous and current environmental conditions was determined experimentally. This parameter depended not only on the magnitude of the change between the previous and current environmental conditions but also on the current growth conditions. In an exponentially growing population, any change in the environment requiring a certain amount of work to adapt to the new conditions initiated a lag period that lasted until that work was finished. Observations for several scenarios in which exponential growth was halted by a sudden change in the temperature and/or a(w) were in good agreement with predictions. When a population already in a lag period was subjected to environmental fluctuations, the system was reset with a new lag phase. The work to be done during the new lag phase was estimated to be the workload due to the environmental change plus the unfinished workload from the uncompleted previous lag phase.

Injury tolerance and moment response of the knee joint to combined valgus bending and shear loading.

PubMed

Bose, Dipan; Bhalla, Kavi S; Untaroiu, Costin D; Ivarsson, B Johan; Crandall, Jeff R; Hurwitz, Shepard

2008-06-01

Valgus bending and shearing of the knee have been identified as primary mechanisms of injuries in a lateral loading environment applicable to pedestrian-car collisions. Previous studies have reported on the structural response of the knee joint to pure valgus bending and lateral shearing, as well as the estimated injury thresholds for the knee bending angle and shear displacement based on experimental tests. However, epidemiological studies indicate that most knee injuries are due to the combined effects of bending and shear loading. Therefore, characterization of knee stiffness for combined loading and the associated injury tolerances is necessary for developing vehicle countermeasures to mitigate pedestrian injuries. Isolated knee joint specimens (n=40) from postmortem human subjects were tested in valgus bending at a loading rate representative of a pedestrian-car impact. The effect of lateral shear force combined with the bending moment on the stiffness response and the injury tolerances of the knee was concurrently evaluated. In addition to the knee moment-angle response, the bending angle and shear displacement corresponding to the first instance of primary ligament failure were determined in each test. The failure displacements were subsequently used to estimate an injury threshold function based on a simplified analytical model of the knee. The validity of the determined injury threshold function was subsequently verified using a finite element model. Post-test necropsy of the knees indicated medial collateral ligament injury consistent with the clinical injuries observed in pedestrian victims. The moment-angle response in valgus bending was determined at quasistatic and dynamic loading rates and compared to previously published test data. The peak bending moment values scaled to an average adult male showed no significant change with variation in the superimposed shear load. An injury threshold function for the knee in terms of bending angle and shear displacement was determined by performing regression analysis on the experimental data. The threshold values of the bending angle (16.2 deg) and shear displacement (25.2 mm) estimated from the injury threshold function were in agreement with previously published knee injury threshold data. The continuous knee injury function expressed in terms of bending angle and shear displacement enabled injury prediction for combined loading conditions such as those observed in pedestrian-car collisions.

A novel device using the Nordic hamstring exercise to assess eccentric knee flexor strength: a reliability and retrospective injury study.

PubMed

Opar, David A; Piatkowski, Timothy; Williams, Morgan D; Shield, Anthony J

2013-09-01

Reliability and case-control injury study. To determine if a novel device designed to measure eccentric knee flexor strength via the Nordic hamstring exercise displays acceptable test-retest reliability; to determine normative values for eccentric knee flexor strength derived from the device in individuals without a history of hamstring strain injury (HSI); and to determine if the device can detect weakness in elite athletes with a previous history of unilateral HSI. HSI and reinjury are the most common cause of lost playing time in a number of sports. Eccentric knee flexor weakness is a major modifiable risk factor for future HSI. However, at present, there is a lack of easily accessible equipment to assess eccentric knee flexor strength. Thirty recreationally active males without a history of HSI completed the Nordic hamstring exercise on the device on 2 separate occasions. Intraclass correlation coefficients, typical error, typical error as a coefficient of variation, and minimal detectable change at a 95% confidence level were calculated. Normative strength data were determined using the most reliable measurement. An additional 20 elite athletes with a unilateral history of HSI within the previous 12 months performed the Nordic hamstring exercise on the device to determine if residual eccentric muscle weakness existed in the previously injured limb. The device displayed high to moderate reliability (intraclass correlation coefficient = 0.83-0.90; typical error, 21.7-27.5 N; typical error as a coefficient of variation, 5.8%-8.5%; minimal detectable change at a 95% confidence level, 60.1-76.2 N). Mean ± SD normative eccentric flexor strength in the uninjured group was 344.7 ± 61.1 N for the left and 361.2 ± 65.1 N for the right side. The previously injured limb was 15% weaker than the contralateral uninjured limb (mean difference, 50.3 N; 95% confidence interval: 25.7, 74.9; P<.01), 15% weaker than the normative left limb (mean difference, 50.0 N; 95% confidence interval: 1.4, 98.5; P = .04), and 18% weaker than the normative right limb (mean difference, 66.5 N; 95% confidence interval: 18.0, 115.1; P<.01). The experimental device offers a reliable method to measure eccentric knee flexor strength and strength asymmetry and to detect residual weakness in previously injured elite athletes.

Determination of Zn/Cu ratio and oligoelements in serum samples by total reflection X-ray fluorescence spectrometry for cancer diagnosis

NASA Astrophysics Data System (ADS)

Marcó P., L. M.; Jiménez, E.; Hernández C., E. A.; Rojas, A.; Greaves, E. D.

2001-11-01

The method of quantification using the Compton peak as an internal standard, developed in a previous work, was applied to the routine determination of Fe, Cu, Zn and Se in serum samples from normal individuals and cancer patients by total reflection X-ray fluorescence spectrometry. Samples were classified according to age and sex of the donor, in order to determine reference values for normal individuals. Results indicate that the Zn/Cu ratio and the Cu concentration could prove to be useful tools for cancer diagnosis. Significant differences in these parameters between the normal and cancer group were found for all age ranges. The multielemental character of the technique, coupled with the small amounts of sample required and the short analysis time make it a valuable tool in clinical analysis.

Thermometric studies on the Fe(III)-EDTA chelate.

PubMed

Dot, K

1978-02-01

A DeltaH of -11.5 +/- 0.5 kJ/mole has been determined for the formation of the Fe(III)-EDTA chelate at 25.0 degrees and mu = 0.1(= [HClO(4)] + [NaClO(4)]) by a direct thermometric titration procedure. The entropy change, DeltaS, has been calculated to be 440 J.mole(-1) .deg(-1) by combining the result of the heat measurements with the free energy change obtained from the stability constant previously determined. A relationship between the DeltaS values and the standard partial molal entropies of the tervalent metal ions is discussed. In addition, conditions for the thermometric titration of Fe(III) with NA(4)EDTA at room temperature have been investigated. Iron(III) can be determined in the presence of fairly large amounts of phosphate, Cr(III), Mn(II) and Al(III).

New constraints on Mars rotation determined from radiometric tracking of the Opportunity Mars Exploration Rover

NASA Astrophysics Data System (ADS)

Kuchynka, Petr; Folkner, William M.; Konopliv, Alex S.; Parker, Timothy J.; Park, Ryan S.; Le Maistre, Sebastien; Dehant, Veronique

2014-02-01

The Opportunity Mars Exploration Rover remained stationary between January and May 2012 in order to conserve solar energy for running its survival heaters during martian winter. While stationary, extra Doppler tracking was performed in order to allow an improved estimate of the martian precession rate. In this study, we determine Mars rotation by combining the new Opportunity tracking data with historic tracking data from the Viking and Pathfinder landers and tracking data from Mars orbiters (Mars Global Surveyor, Mars Odyssey and Mars Reconnaissance Orbiter). The estimated rotation parameters are stable in cross-validation tests and compare well with previously published values. In particular, the Mars precession rate is estimated to be -7606.1 ± 3.5 mas/yr. A representation of Mars rotation as a series expansion based on the determined rotation parameters is provided.

Validation of a Clinical Scoring System for Outcome Prediction in Dogs with Acute Kidney Injury Managed by Hemodialysis.

PubMed

Segev, G; Langston, C; Takada, K; Kass, P H; Cowgill, L D

2016-05-01

A scoring system for outcome prediction in dogs with acute kidney injury (AKI) recently has been developed but has not been validated. The scoring system previously developed for outcome prediction will accurately predict outcome in a validation cohort of dogs with AKI managed with hemodialysis. One hundred fifteen client-owned dogs with AKI. Medical records of dogs with AKI treated by hemodialysis between 2011 and 2015 were reviewed. Dogs were included only if all variables required to calculate the final predictive score were available, and the 30-day outcome was known. A predictive score for 3 models was calculated for each dog. Logistic regression was used to evaluate the association of the final predictive score with each model's outcome. Receiver operating curve (ROC) analyses were performed to determine sensitivity and specificity for each model based on previously established cut-off values. Higher scores for each model were associated with decreased survival probability (P < .001). Based on previously established cut-off values, 3 models (models A, B, C) were associated with sensitivities/specificities of 73/75%, 71/80%, and 75/86%, respectively, and correctly classified 74-80% of the dogs. All models were simple to apply and allowed outcome prediction that closely corresponded with actual outcome in an independent cohort. As expected, accuracies were slightly lower compared with those from the previously reported cohort used initially to develop the models. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Assessing the Value of Frost Forecasts to Orchardists: A Dynamic Decision-Making Approach.

NASA Astrophysics Data System (ADS)

Katz, Richard W.; Murphy, Allan H.; Winkler, Robert L.

1982-04-01

The methodology of decision analysis is used to investigate the economic value of frost (i.e., minimum temperature) forecasts to orchardists. First, the fruit-frost situation and previous studies of the value of minimum temperature forecasts in this context are described. Then, after a brief overview of decision analysis, a decision-making model for the fruit-frost problem is presented. The model involves identifying the relevant actions and events (or outcomes), specifying the effect of taking protective action, and describing the relationships among temperature, bud loss, and yield loss. A bivariate normal distribution is used to model the relationship between forecast and observed temperatures, thereby characterizing the quality of different types of information. Since the orchardist wants to minimize expenses (or maximize payoffs) over the entire frost-protection season and since current actions and outcomes at any point in the season are related to both previous and future actions and outcomes, the decision-making problem is inherently dynamic in nature. As a result, a class of dynamic models known as Markov decision processes is considered. A computational technique called dynamic programming is used in conjunction with these models to determine the optimal actions and to estimate the value of meteorological information.Some results concerning the value of frost forecasts to orchardists in the Yakima Valley of central Washington are presented for the cases of red delicious apples, bartlett pears, and elberta peaches. Estimates of the parameter values in the Markov decision process are obtained from relevant physical and economic data. Twenty years of National Weather Service forecast and observed temperatures for the Yakima key station are used to estimate the quality of different types of information, including perfect forecasts, current forecasts, and climatological information. The orchardist's optimal actions over the frost-protection season and the expected expenses associated with the use of such information are determined using a dynamic programming algorithm. The value of meteorological information is defined as the difference between the expected expense for the information of interest and the expected expense for climatological information. Over the entire frost-protection season, the value estimates (in 1977 dollars) for current forecasts were $808 per acre for red delicious apples, $492 per acre for bartlett pears, and $270 per acre for elberta peaches. These amounts account for 66, 63, and 47%, respectively, of the economic value associated with decisions based on perfect forecasts. Varying the quality of the minimum temperature forecasts reveals that the relationship between the accuracy and value of such forecasts is nonlinear and that improvements in current forecasts would not be as significant in terms of economic value as were comparable improvements in the past.Several possible extensions of this study of the value of frost forecasts to orchardists are briefly described. Finally, the application of the dynamic model formulated in this paper to other decision-making problems involving the use of meteorological information is mentioned.

Uptake and fate of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in coastal marine biota determined using a stable isotopic tracer, (15)N - [RDX].

PubMed

Ballentine, Mark L; Ariyarathna, Thivanka; Smith, Richard W; Cooper, Christopher; Vlahos, Penny; Fallis, Stephen; Groshens, Thomas J; Tobias, Craig

2016-06-01

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is globally one of the most commonly used military explosives and environmental contaminant. (15)N labeled RDX was added into a mesocosm containing 9 different coastal marine species in a time series experiment to quantify the uptake of RDX and assess the RDX derived (15)N retention into biota tissue. The (15)N attributed to munitions compounds reached steady state concentrations ranging from 0.04 to 0.67 μg (15)N g dw(-1), the bulk (15)N tissue concentration for all species was 1-2 orders of magnitude higher suggesting a common mechanism or pathway of RDX biotransformation and retention of (15)N. A toxicokinetic model was created that described the (15)N uptake, elimination, and transformation rates. While modeled uptake rates were within previous published values, elimination rates were several orders of magnitude smaller than previous studies ranging from 0.05 to 0.7 days(-1). These small elimination rates were offset by high rates of retention of (15)N previously not measured. Bioconcentration factors and related aqueous:organism ratios of compounds and tracer calculated using different tracer and non-tracer methods yielded a broad range of values (0.35-101.6 mL g(-1)) that were largely method dependent. Despite the method-derived variability, all values were generally low and consistent with little bioaccumulation potential. The use of (15)N labeled RDX in this study indicates four possible explanations for the observed distribution of compounds and tracer; each with unique potential implications for possible toxicological impacts in the coastal marine environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Human exposure to metals: levels in autopsy tissues of individuals living near a hazardous waste incinerator.

PubMed

Mari, Montse; Nadal, Martí; Schuhmacher, Marta; Barbería, Eneko; García, Francisco; Domingo, José L

2014-06-01

The concentrations of a number of metals were determined in the brain, bone, kidney, liver, and lung of 20 autopsied subjects who had lived, at least 10 years, in the neighborhood of a hazardous waste incinerator (HWI) in Tarragona (Catalonia, Spain). Results were compared with those obtained in 1998 (baseline survey) and previous surveys (2003 and 2007). Arsenic, Be, Ni, Tl, and V showed concentrations below the corresponding detection limits in all tissues. Cadmium showed the highest levels in the kidney, with a mean value of 21.15 μg/g. However, Cd was found below the detection limit in the brain and bone. Chromium showed similar concentrations in the kidney, brain, and lung (range of mean values, 0.57-0.66 μg/g) and higher in the bone (1.38 μg/g). In turn, Hg was below the detection limit in all tissues with the exception of the kidney, where the mean concentration was 0.15 μg/g (range, <0.05-0.58 μg/g). On the other hand, Mn could be detected in all tissues showing the highest levels in the liver and kidney (1.45 and 1.09 μg/g, respectively). Moreover, Pb showed the highest concentrations in bone (mean, 1.39 μg/g; range, <0.025-4.88 μg/g). Finally, Sn could be detected only in some tissue samples, reaching the highest values in the bone (0.17 μg/g). The current metal levels in human tissues from individuals living near the HWI of Tarragona are comparable and of a similar magnitude to previously reported results corresponding to general populations, as well as those of our previous surveys.

Partial least squares analysis of rocket propulsion fuel data using diaphragm valve-based comprehensive two-dimensional gas chromatography coupled with flame ionization detection.

PubMed

Freye, Chris E; Fitz, Brian D; Billingsley, Matthew C; Synovec, Robert E

2016-06-01

The chemical composition and several physical properties of RP-1 fuels were studied using comprehensive two-dimensional (2D) gas chromatography (GC×GC) coupled with flame ionization detection (FID). A "reversed column" GC×GC configuration was implemented with a RTX-wax column on the first dimension ((1)D), and a RTX-1 as the second dimension ((2)D). Modulation was achieved using a high temperature diaphragm valve mounted directly in the oven. Using leave-one-out cross-validation (LOOCV), the summed GC×GC-FID signal of three compound-class selective 2D regions (alkanes, cycloalkanes, and aromatics) was regressed against previously measured ASTM derived values for these compound classes, yielding root mean square errors of cross validation (RMSECV) of 0.855, 0.734, and 0.530mass%, respectively. For comparison, using partial least squares (PLS) analysis with LOOCV, the GC×GC-FID signal of the entire 2D separations was regressed against the same ASTM values, yielding a linear trend for the three compound classes (alkanes, cycloalkanes, and aromatics), yielding RMSECV values of 1.52, 2.76, and 0.945 mass%, respectively. Additionally, a more detailed PLS analysis was undertaken of the compounds classes (n-alkanes, iso-alkanes, mono-, di-, and tri-cycloalkanes, and aromatics), and of physical properties previously determined by ASTM methods (such as net heat of combustion, hydrogen content, density, kinematic viscosity, sustained boiling temperature and vapor rise temperature). Results from these PLS studies using the relatively simple to use and inexpensive GC×GC-FID instrumental platform are compared to previously reported results using the GC×GC-TOFMS instrumental platform. Copyright © 2016 Elsevier B.V. All rights reserved.

Stable isotope ratio analysis of breastfeeding and weaning practices of children from medieval Fishergate House York, UK.

PubMed

Burt, Nicole M

2013-11-01

Rib collagen of 51 juveniles and 11 adult females from the late medieval Fishergate House cemetery site (York, UK) were analyzed using nitrogen and carbon stable isotope ratio analysis to determine the weaning age for this population and to reconstruct diet. The juveniles' ages ranged from fetal to 5-6 years, while the females were of reproductive age. Previous researchers suggested that the children from Fishergate House might have been weaned later than the medieval British norm of 2 years, based on a mortality peak at 4-6 years of age. The results show weaning was complete by 2 years of age, agreeing with previous British weaning studies. The adult female δ(15) N values have a mean of 11.4‰ ± 1.1‰ and the δ(13) C values have a mean of -19.4‰ ± 0.4‰. These findings are consistent with previous isotopic studies of female diet in York during this period, though slightly lower. The weaned juvenile nitrogen values were found to be higher than the adult females (12.4‰ ± 1.0‰ for δ(15) N and -19.7‰ ± 0.5‰ for δ(13) C), which might indicate a dependence on higher trophic level proteins such as marine fish or pork. Marine fish is considered a high status food and children are considered low-status individuals at this time, making this a particularly interesting finding. Weaning does not appear to coincide with peak mortality, suggesting environment factors may be playing a larger role in child mortality at Fishergate House. Copyright © 2013 Wiley Periodicals, Inc.

Complementary sex determination substantially increases extinction proneness of haplodiploid populations.

PubMed

Zayed, Amro; Packer, Laurence

2005-07-26

The role of genetic factors in extinction is firmly established for diploid organisms, but haplodiploids have been considered immune to genetic load impacts because deleterious alleles are readily purged in haploid males. However, we show that single-locus complementary sex determination ancestral to the haplodiploid Hymenoptera (ants, bees, and wasps) imposes a substantial genetic load through homozygosity at the sex locus that results in the production of inviable or sterile diploid males. Using stochastic modeling, we have discovered that diploid male production (DMP) can initiate a rapid and previously uncharacterized extinction vortex. The extinction rate in haplodiploid populations with DMP is an order of magnitude greater than in its absence under realistic but conservative demographic parameter values. Furthermore, DMP alone can elevate the base extinction risk in haplodiploids by over an order of magnitude higher than that caused by inbreeding depression in threatened diploids. Thus, contrary to previous expectations, haplodiploids are more, rather than less, prone to extinction for genetic reasons. Our findings necessitate a fundamental shift in approaches to the conservation and population biology of these ecologically and economically crucial insects.

Fundamental data on the desorption of pure interstellar ices

NASA Astrophysics Data System (ADS)

Brown, Wendy A.; Bolina, Amandeep S.

2007-01-01

The desorption of molecular ices from grain surfaces is important in a number of astrophysical environments including dense molecular clouds, cometary nuclei and the surfaces and atmospheres of some planets. With this in mind, we have performed a detailed investigation of the desorption of pure water, pure methanol and pure ammonia ices from a model dust-grain surface. We have used these results to determine the desorption energy, order of desorption and the pre-exponential factor for the desorption of these molecular ices from our model surface. We find good agreement between our desorption energies and those determined previously; however, our values for the desorption orders, and hence also the pre-exponential factors, are different to those reported previously. The kinetic parameters derived from our data have been used to model desorption on time-scales relevant to astrophysical processes and to calculate molecular residence times, given in terms of population half-life as a function of temperature. These results show the importance of laboratory data for the understanding of astronomical situations whereby icy mantles are warmed by nearby stars and by other dynamical events.

Quantifying CD4 receptor protein in two human CD4+ lymphocyte preparations for quantitative flow cytometry.

PubMed

Wang, Meiyao; Misakian, Martin; He, Hua-Jun; Bajcsy, Peter; Abbasi, Fatima; Davis, Jeffrey M; Cole, Kenneth D; Turko, Illarion V; Wang, Lili

2014-01-01

In our previous study that characterized different human CD4+ lymphocyte preparations, it was found that both commercially available cryopreserved peripheral blood mononuclear cells (PBMC) and a commercially available lyophilized PBMC (Cyto-Trol™) preparation fulfilled a set of criteria for serving as biological calibrators for quantitative flow cytometry. However, the biomarker CD4 protein expression level measured for T helper cells from Cyto-Trol was about 16% lower than those for cryopreserved PBMC and fresh whole blood using flow cytometry and mass cytometry. A primary reason was hypothesized to be due to steric interference in anti- CD4 antibody binding to the smaller sized lyophilized control cells. Targeted multiple reaction monitoring (MRM) mass spectrometry (MS) is used to quantify the copy number of CD4 receptor protein per CD4+ lymphocyte. Scanning electron microscopy (SEM) is utilized to assist searching the underlying reasons for the observed difference in CD4 receptor copy number per cell determined by MRM MS and CD4 expression measured previously by flow cytometry. The copy number of CD4 receptor proteins on the surface of the CD4+ lymphocyte in cryopreserved PBMCs and in lyophilized control cells is determined to be (1.45 ± 0.09) × 10(5) and (0.85 ± 0.11) × 10(5), respectively, averaged over four signature peptides using MRM MS. In comparison with cryopreserved PBMCs, there are more variations in the CD4 copy number in lyophilized control cells determined based on each signature peptide. SEM images of CD4+ lymphocytes from lyophilized control cells are very different when compared to the CD4+ T cells from whole blood and cryopreserved PBMC. Because of the lyophilization process applied to Cyto-Trol control cells, a lower CD4 density value, defined as the copy number of CD4 receptors per CD4+ lymphocyte, averaged over three different production lots is most likely explained by the loss of the CD4 receptors on damaged and/or broken microvilli where CD4 receptors reside. Steric hindrance of antibody binding and the association of CD4 receptors with other biomolecules likely contribute significantly to the nearly 50% lower CD4 receptor density value for cryopreserved PBMC determined from flow cytometry compared to the value obtained from MRM MS.

Patient-specific dose calculations for pediatric CT of the chest, abdomen and pelvis

PubMed Central

Fraser, Nicholas D.; Carver, Diana E.; Pickens, David R.; Price, Ronald R.; Hernanz-Schulman, Marta; Stabin, Michael G.

2015-01-01

Background Organ dose is essential for accurate estimates of patient dose from CT. Objective To determine organ doses from a broad range of pediatric patients undergoing diagnostic chest–abdomen–pelvis CT and investigate how these relate to patient size. Materials and methods We used a previously validated Monte Carlo simulation model of a Philips Brilliance 64 multi-detector CT scanner (Philips Healthcare, Best, The Netherlands) to calculate organ doses for 40 pediatric patients (M:F=21:19; range 0.6–17 years). Organ volumes and positions were determined from the images using standard segmentation techniques. Non-linear regression was performed to determine the relationship between volume CT dose index (CTDIvol)-normalized organ doses and abdominopelvic diameter. We then compared results with values obtained from independent studies. Results We found that CTDIvol-normalized organ dose correlated strongly with exponentially decreasing abdominopelvic diameter (R2>0.8 for most organs). A similar relationship was determined for effective dose when normalized by dose-length product (R2=0.95). Our results agreed with previous studies within 12% using similar scan parameters (i.e. bowtie filter size, beam collimation); however results varied up to 25% when compared to studies using different bowtie filters. Conclusion Our study determined that organ doses can be estimated from measurements of patient size, namely body diameter, and CTDIvol prior to CT examination. This information provides an improved method for patient dose estimation. PMID:26142256

Changes in ecosystem service values in Zhoushan Island using remote sensing time series data

NASA Astrophysics Data System (ADS)

Zhang, Xiaoping; Qin, Yanpei; Lv, Ying; Zhen, Guangwei; Gong, Fang; Li, Chaokui

2017-10-01

The largest inhabited island, Zhoushan Island, is the center of economy, culture, shipping, and fishing in the Zhoushan Archipelago New Area. Its coastal wetland and tidal flats offer significant ecological services including floodwater storage, wildlife habitat, and buffers against tidal surges. Yet, large-scale land reclamation and new land development may dramatically change ecosystem services. In this research, we assess changes in ecosystem service values in Zhoushan Island during 1990-2000-2011. Three LANDSAT TM and/or ETM data sets were used to determine the spatial pattern of land use, and previously published value coefficients were used to calculate the ecosystem service values delivered by each land category. The results show that total value of ecosystem services in Zhoushan Island declined by 11% from 2920.07 billion Yuan to 2609.77 billion Yuan per year between 1990 and 2011. This decrease is largely attributable to the 51% loss of tidal flats. The combined ecosystem service values of woodland, paddy land and tidal flats were over 90% of the total values. The result indicates that future land-use policy should pay attention to the conservation of these ecosystems over uncontrolled reclamation and coastal industrial development, and that further coastal reclamation should be on rigorous environmental impact analyses.

Assigning Robust Default Values in Building Performance Simulation Software for Improved Decision-Making in the Initial Stages of Building Design.

PubMed

Hiyama, Kyosuke

2015-01-01

Applying data mining techniques on a database of BIM models could provide valuable insights in key design patterns implicitly present in these BIM models. The architectural designer would then be able to use previous data from existing building projects as default values in building performance simulation software for the early phases of building design. The author has proposed the method to minimize the magnitude of the variation in these default values in subsequent design stages. This approach maintains the accuracy of the simulation results in the initial stages of building design. In this study, a more convincing argument is presented to demonstrate the significance of the new method. The variation in the ideal default values for different building design conditions is assessed first. Next, the influence of each condition on these variations is investigated. The space depth is found to have a large impact on the ideal default value of the window to wall ratio. In addition, the presence or absence of lighting control and natural ventilation has a significant influence on the ideal default value. These effects can be used to identify the types of building conditions that should be considered to determine the ideal default values.

Assigning Robust Default Values in Building Performance Simulation Software for Improved Decision-Making in the Initial Stages of Building Design

PubMed Central

2015-01-01

Applying data mining techniques on a database of BIM models could provide valuable insights in key design patterns implicitly present in these BIM models. The architectural designer would then be able to use previous data from existing building projects as default values in building performance simulation software for the early phases of building design. The author has proposed the method to minimize the magnitude of the variation in these default values in subsequent design stages. This approach maintains the accuracy of the simulation results in the initial stages of building design. In this study, a more convincing argument is presented to demonstrate the significance of the new method. The variation in the ideal default values for different building design conditions is assessed first. Next, the influence of each condition on these variations is investigated. The space depth is found to have a large impact on the ideal default value of the window to wall ratio. In addition, the presence or absence of lighting control and natural ventilation has a significant influence on the ideal default value. These effects can be used to identify the types of building conditions that should be considered to determine the ideal default values. PMID:26090512

Water adsorption constrained Frenkel-Halsey-Hill adsorption activation theory: Montmorillonite and illite

NASA Astrophysics Data System (ADS)

Hatch, Courtney D.; Greenaway, Ann L.; Christie, Matthew J.; Baltrusaitis, Jonas

2014-04-01

Fresh mineral aerosol has recently been found to be effective cloud condensation nuclei (CCN) and contribute to the number of cloud droplets in the atmosphere due to the effect of water adsorption on CCN activation. The work described here uses experimental water adsorption measurements on Na-montmorillonite and illite clay to determine empirical adsorption parameters that can be used in a recently derived theoretical framework (Frenkel-Halsey-Hill Activation Theory, FHH-AT) that accounts for the effect of water adsorption on CCN activation. Upon fitting the Frenkel-Halsey-Hill (FHH) adsorption model to water adsorption measurements, we find FHH adsorption parameters, AFHH and BFHH, to be 98 ± 22 and 1.79 ± 0.11 for montmorillonite and 75 ± 17 and 1.77 ± 0.11 for illite, respectively. The AFHH and BFHH values obtained from water adsorption measurements differ from values reported previously determined by applying FHH-AT to CCN activation measurements. Differences in FHH adsorption parameters were attributed to different methods used to obtain them and the hydratable nature of the clays. FHH adsorption parameters determined from water adsorption measurements were then used to calculate the critical super-saturation (sc) for CCN activation using FHH-AT. The relationship between sc and the dry particle diameter (Ddry) gave CCN activation curve exponents (xFHH) of -0.61 and -0.64 for montmorillonite and illite, respectively. The xFHH values were slightly lower than reported previously for mineral aerosol. The lower exponent suggests that the CCN activity of hydratable clays is less sensitive to changes in Ddry and the hygroscopicity parameter exhibits a broader variability with Ddry compared to more soluble aerosols. Despite the differences in AFHH, BFHH and xFHH, the FHH-AT derived CCN activities of montmorillonite and illite are quite similar to each other and in excellent agreement with experimental CCN measurements resulting from wet-generated clay aerosol. This study illustrates that FHH-AT using adsorption parameters constrained by water adsorption is a simple, valid method for predicting CCN activation of fresh clay minerals and provides parameters that can be used in atmospheric models to study the effect of mineral dust aerosol on cloud formation and climate.

Measurement of the structure functions F 2 and xF 3 and comparison with QCD predictions including kinematical and dynamical higher twist effects

NASA Astrophysics Data System (ADS)

Varvell, K.; Cooper-Sarkar, A. M.; Parker, M. A.; Sansum, R. A.; Aderholz, M.; Armenise, N.; Baton, J. P.; Bullock, F. W.; Berggren, M.; Bertrand, D.; Brisson, V.; Burkot, W.; Calcchio, M.; Claytoh, E. F.; Coghen, T.; Erriquez, O.; Fitch, P. J.; Gerbier, G.; Guy, J.; Hulth, P. O.; Iaselli, G.; Jones, G. T.; Kasper, P.; Klein, H.; Kochowski, C.; Marage, P.; Mermikides, M.; Middleton, R. P.; Morrison, D. R. O.; Mobayyen, M. M.; Natali, S.; Neveu, M.; Nuzzo, S.; O'Neale, S. W.; Petiau, P.; Petrides, A.; Ruggieri, F.; Sacton, J.; Simopoulou, E.; Vallee, C.; Vayaki, A.; Venus, W. A.; Wachsmuth, H.; Wells, J.; Wittek, W.

1987-03-01

The isoscalar nucleon structure functions F 2( x, Q 2) and xF 3( x, Q 2) are measured in the range 0< Q 2<64 GeV2, 1.7< W 2<250 GeV2, x<0.7 using ν andbar v interactions on neon in BEBC. The data are used to evaluate possible higher twist contributions and to determine their impact on the evaluation of the QCD parameter Λ. In contrast to previous analyses reaching to such low W 2 values, it is found that a lowΛ _{overline {MS} } value in the neighbourhood of 100 MeV describes the data adequately and that the contribution of dynamical higher twist effects is small and negative.

Ku-band radar threshold analysis

NASA Technical Reports Server (NTRS)

Weber, C. L.; Polydoros, A.

1979-01-01

The statistics of the CFAR threshold for the Ku-band radar was determined. Exact analytical results were developed for both the mean and standard deviations in the designated search mode. The mean value is compared to the results of a previously reported simulation. The analytical results are more optimistic than the simulation results, for which no explanation is offered. The normalized standard deviation is shown to be very sensitive to signal-to-noise ratio and very insensitive to the noise correlation present in the range gates of the designated search mode. The substantial variation in the CFAR threshold is dominant at large values of SNR where the normalized standard deviation is greater than 0.3. Whether or not this significantly affects the resulting probability of detection is a matter which deserves additional attention.

The Heats of Formation of SiCl+n, for n=1-4

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Partridge, Harry; Arnold, James O. (Technical Monitor)

1997-01-01

The heats of formation of SiCl(sub n) and SiCl+(sub n), for n=1-4, have been determined using the G2(B3LYP/MP2/CC) approach. The results for the neutral systems are in very good agreement with previous work. High level calibration calculations show that ion results have about the same accuracy as the neutrals, and allow us to refine the G2(B3LYP/MP2/CC) values. The calculations show that the adiabatic IP of SiCl4 is about 7 kcal/mol smaller than the accepted value. Using a rigid rotor/harmonic oscillator approximation, the temperature dependence of the heat of formation, heat capacity, and entropy are computed for 300 to 4000 K and fit to a polynomial.

Revising the Evolutionary Stage of HD 163899: The Effects of Convective Overshooting and Rotation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ostrowski, Jakub; Daszyńska-Daszkiewicz, Jadwiga; Cugier, Henryk, E-mail: ostrowski@astro.uni.wroc.pl

We revise the evolutionary status of the B-type supergiant HD 163899 based on the new determinations of the mass–luminosity ratio, effective temperature, and rotational velocity, as well as on the interpretation of the oscillation spectrum of the star. The observed value of the nitrogen-to-carbon abundance fixes the value of the rotation rate of the star. Now, more massive models are strongly preferred than those previously considered, and it is very likely that the star is still in the main-sequence stage. The rotationally induced mixing manifests as the nitrogen overabundance in the atmosphere, which agrees with our analysis of the HARPSmore » spectra. Thus, HD 163899 probably belongs to a group of evolved nitrogen-rich main-sequence stars.« less

User-customized brain computer interfaces using Bayesian optimization

NASA Astrophysics Data System (ADS)

Bashashati, Hossein; Ward, Rabab K.; Bashashati, Ali

2016-04-01

Objective. The brain characteristics of different people are not the same. Brain computer interfaces (BCIs) should thus be customized for each individual person. In motor-imagery based synchronous BCIs, a number of parameters (referred to as hyper-parameters) including the EEG frequency bands, the channels and the time intervals from which the features are extracted should be pre-determined based on each subject’s brain characteristics. Approach. To determine the hyper-parameter values, previous work has relied on manual or semi-automatic methods that are not applicable to high-dimensional search spaces. In this paper, we propose a fully automatic, scalable and computationally inexpensive algorithm that uses Bayesian optimization to tune these hyper-parameters. We then build different classifiers trained on the sets of hyper-parameter values proposed by the Bayesian optimization. A final classifier aggregates the results of the different classifiers. Main Results. We have applied our method to 21 subjects from three BCI competition datasets. We have conducted rigorous statistical tests, and have shown the positive impact of hyper-parameter optimization in improving the accuracy of BCIs. Furthermore, We have compared our results to those reported in the literature. Significance. Unlike the best reported results in the literature, which are based on more sophisticated feature extraction and classification methods, and rely on prestudies to determine the hyper-parameter values, our method has the advantage of being fully automated, uses less sophisticated feature extraction and classification methods, and yields similar or superior results compared to the best performing designs in the literature.

Serum proteins by capillary zone electrophoresis: approaches to the definition of reference values.

PubMed

Petrini, C; Alessio, M G; Scapellato, L; Brambilla, S; Franzini, C

1999-10-01

The Paragon CZE 2000 (Beckman Analytical, Milan, Italy) is an automatic dedicated capillary zone electrophoresis (CZE) system, producing a five-zone serum protein pattern with quantitative estimation of the zones. With the view of substituting this instrument for two previously used serum protein electrophoresis techniques, we planned to produce reference values for the "new" systems leading to compatible interpretation of the results. High resolution cellulose acetate electrophoresis with visual inspection and descriptive reporting (HR-CAE) and five-zone cellulose acetate electrophoresis with densitometry (CAE-D) were the previously used techniques. Serum samples (n = 167) giving "normal pattern" with HR-CAE were assayed with the CZE system, and the results were statistically assessed to yield 0.95 reference intervals. One thousand normal and pathological serum samples were then assayed with the CAE-D and the CZE techniques, and the regression equations of the CAE-D values over the CZE values for the five zones were used to transform the CAE-D reference limits into the CZE reference limits. The two sets of reference values thereby produced were in good agreement with each other and also with reference values previously reported for the CZE system. Thus, reference values for the CZE techniques permit interpretation of results coherent with the previously used techniques and reporting modes.

Mass determination near N = 20 for Al and Na isotopes

DOE PAGES

Gallant, A. T.; Alanssari, M.; Bale, J. C.; ...

2017-08-31

We report on the mass measurements of 31;32Na and 29;34;35Al, performed with the TITAN Penning trap mass spectrometer at TRIUMF. The mass excesses were found to be 12246(14) keV and 18638(37) keV for 31;32Na and -18207:77(37) keV, -3000:5(29) keV, and -223:7(73) keV for 29;34;35Al, respectively. Our measurements con rm the observation of a crossover in the two-neutron separation energies of 33Mg and 34Al. We did not observe the recently reported, long-lived, isomeric state of 34Al, but, based on the previously measured half-lives, the mass value of the ground state was determined.

High-precision half-life determination for 21Na using a 4 π gas-proportional counter

NASA Astrophysics Data System (ADS)

Finlay, P.; Laffoley, A. T.; Ball, G. C.; Bender, P. C.; Dunlop, M. R.; Dunlop, R.; Hackman, G.; Leslie, J. R.; MacLean, A. D.; Miller, D.; Moukaddam, M.; Olaizola, B.; Severijns, N.; Smith, J. K.; Southall, D.; Svensson, C. E.

2017-08-01

A high-precision half-life measurement for the superallowed β+ transition between the isospin T =1 /2 mirror nuclei 21Na and 21Ne has been performed at the TRIUMF-ISAC radioactive ion beam facility yielding T1 /2=22.4506 (33 ) s, a result that is a factor of 4 more precise than the previous world-average half-life for 21Na and represents the single most precisely determined half-life for a transition between mirror nuclei to date. The contribution to the uncertainty in the 21Na F tmirror value due to the half-life is now reduced to the level of the nuclear-structure-dependent theoretical corrections, leaving the branching ratio as the dominant experimental uncertainty.

Pressure-induced luminescence quenching in KY(WO4)2:Pr3+

NASA Astrophysics Data System (ADS)

Mahlik, S.; Diaz, F.; Boutinaud, P.

2017-12-01

The quenching of the red Pr3+ (1D2 → 3H4) luminescence in a single crystal of KY(WO4)2 doped with Pr3+ is investigated at room temperature under high hydrostatic pressure. The quenching is ascribed to a pressure-induced downshift of the Pr3+ → W6+ metal-to-metal charge transfer (or impurity trapped exciton) state. The concomitant decrease of the 1D2 → 3H4 emission lifetime is reproduced using a phenomenological model. The fitting allows the determination of the pressure-induced shrinkage of the Pr3+(Y3+)-W6+ distance in the crystal. The value is consistent with the quantity previously determined in CaWO4 by means of X-ray diffraction.

Mars Pathfinder Near-Field Rock Distribution Re-Evaluation

NASA Technical Reports Server (NTRS)

Haldemann, A. F. C.; Golombek, M. P.

2003-01-01

We have completed analysis of a new near-field rock count at the Mars Pathfinder landing site and determined that the previously published rock count suggesting 16% cumulative fractional area (CFA) covered by rocks is incorrect. The earlier value is not so much wrong (our new CFA is 20%), as right for the wrong reason: both the old and the new CFA's are consistent with remote sensing data, however the earlier determination incorrectly calculated rock coverage using apparent width rather than average diameter. Here we present details of the new rock database and the new statistics, as well as the importance of using rock average diameter for rock population statistics. The changes to the near-field data do not affect the far-field rock statistics.

Optimization of the tungsten oxide technique for measurement of atmospheric ammonia

NASA Technical Reports Server (NTRS)

Brown, Kenneth G.

1987-01-01

Hollow tubes coated with tungstic acid have been shown to be of value in the determination of ammonia and nitric acid in ambient air. Practical application of this technique was demonstrated utilizing an automated sampling system for in-flight collection and analysis of atmospheric samples. Due to time constraints these previous measurements were performed on tubes that had not been well characterized in the laboratory. As a result the experimental precision could not be accurately estimated. Since the technique was being compared to other techniques for measuring these compounds, it became necessary to perform laboratory tests which would establish the reliability of the technique. This report is a summary of these laboratory experiments as they are applied to the determination of ambient ammonia concentration.

Nitrogen and triple oxygen isotopes in near-road air samples using chemical conversion and thermal decomposition.

PubMed

Smirnoff, Anna; Savard, Martine M; Vet, Robert; Simard, Marie-Christine

2012-12-15

The determination of triple oxygen (δ(18)O and δ(17)O) and nitrogen isotopes (δ(15)N) is important when investigating the sources and atmospheric paths of nitrate and nitrite. To fully understand the atmospheric contribution into the terrestrial nitrogen cycle, it is crucial to determine the δ(15)N values of oxidised and reduced nitrogen species in precipitation and dry deposition. In an attempt to further develop non-biotic methods and avoid expensive modifications of the gas-equilibration system, we have combined and modified sample preparation procedures and analytical setups used by other researchers. We first chemically converted NO(3)(-) and NH(4)(+) into NO(2)(-) and then into N(2)O. Subsequently, the resulting gas was decomposed into N(2) and O(2) and analyzed by isotope ratio mass spectrometry (IRMS) using a pre-concentration system equipped with a gold reduction furnace. The δ(17)O, δ(18)O and δ(15)N values of nitrate and nitrite samples were acquired simultaneously in one run using a single analytical system. Most importantly, the entire spectrum of δ(17)O, δ(18)O and/or δ(15)N values was determined from atmospheric nitrate, nitric oxide, ammonia and ammonium. The obtained isotopic values for air and precipitation samples were in good agreement with those from previous studies. We have further advanced chemical approaches to sample preparation and isotope analyses of nitrogen-bearing compounds. The proposed methods are inexpensive and easily adaptable to a wide range of laboratory conditions. This will substantially contribute to further studies on sources and pathways of nitrate, nitrite and ammonium in terrestrial nitrogen cycling. Copyright © 2012 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.

Exergy Analysis of Rocket Systems

NASA Technical Reports Server (NTRS)

Gilbert, Andrew; Mesmer, Bryan; Watson, Michael D.

2015-01-01

Exergy is defined as the useful work available from a system in a specified environment. Exergy analysis allows for comparison between different system designs, and allows for comparison of subsystem efficiencies within system designs. The proposed paper explores the relationship between the fundamental rocket equation and an exergy balance equation. A previously derived exergy equation related to rocket systems is investigated, and a higher fidelity analysis will be derived. The exergy assessments will enable informed, value-based decision making when comparing alternative rocket system designs, and will allow the most efficient configuration among candidate configurations to be determined.

The nuclear electric quadrupole moment of copper.

PubMed

Santiago, Régis Tadeu; Teodoro, Tiago Quevedo; Haiduke, Roberto Luiz Andrade

2014-06-21

The nuclear electric quadrupole moment (NQM) of the (63)Cu nucleus was determined from an indirect approach by combining accurate experimental nuclear quadrupole coupling constants (NQCCs) with relativistic Dirac-Coulomb coupled cluster calculations of the electric field gradient (EFG). The data obtained at the highest level of calculation, DC-CCSD-T, from 14 linear molecules containing the copper atom give rise to an indicated NQM of -198(10) mbarn. Such result slightly deviates from the previously accepted standard value given by the muonic method, -220(15) mbarn, although the error bars are superimposed.

Attenuation properties of diagnostic x-ray shielding materials.

PubMed

Archer, B R; Fewell, T R; Conway, B J; Quinn, P W

1994-09-01

Single- and three-phase broad-beam x-ray attenuation data have been obtained using lead, steel, plate glass, gypsum wallboard, lead acrylic, and wood. Tube voltages of 50, 70, 100, 125, and 150 kVp were employed and the resulting curves were compared to transmission data found in the literature. To simplify computation of barrier requirements, all data sets were parametrized by nonlinear least-squares fit to a previously described mathematical model. High attenuation half value layers and the lead equivalence of the alternate materials were also determined.

Thermodynamic measurement of the sound velocity of a Bose gas across the transition to Bose–Einstein condensation

NASA Astrophysics Data System (ADS)

Fritsch, A. R.; Tavares, P. E. S.; Vivanco, F. A. J.; Telles, G. D.; Bagnato, V. S.; Henn, E. A. L.

2018-05-01

We present an alternative method for determining the sound velocity in atomic Bose–Einstein condensates, based on thermodynamic global variables. The total number of trapped atoms was as a function of temperature carefully studied across the phase transition, at constant volume. It allowed us to evaluate the sound velocity resulting in consistent values from the quantum to classical regime, in good agreement with previous results found in literature. We also provide some insight about the dominant sound mode (thermal or superfluid) across a wide temperature range.

Determination of the STIS CCD Gain

NASA Astrophysics Data System (ADS)

Riley, Allyssa; Monroe, TalaWanda; Lockwood, Sean

2016-09-01

This report summarizes the analysis and absolute gain results of the STIS Cycle 23 special calibration program 14424 that was designed to measure the gain of amplifiers A, C and D at nominal gain settings of 1 and 4 e-/DN. We used the mean-variance technique and the results indicate a <3.5% change in the gain for amplifier D from when it was originally calculated pre-flight. We compared these values to previous measurements from Cycles 17 through 23. This report outlines the observations, methodology, and results of the mean-variance technique.

The effect of the rigidity of perfluoropolyether surfactant on its behavior at the water/supercritical carbon dioxide interface.

PubMed

Lu, Lanyuan; Berkowitz, Max L

2005-11-24

We performed a series of molecular dynamics simulations to study the PFPE (perfluoropolyether) and PE (polyether) surfactant monolayers at the water/supercritical carbon dioxide interface. Molecular differences between fluorocarbon surfactant PFPE and its hydrocarbon analogue PE were analyzed. We observed that values of intramolecular bonded interaction parameters which are related to chain rigidity determine the monolayer surface pressure. We show that "good" and "bad" properties of PFPE/PE surfactants are connected to conformational entropy. These results are consistent with our previous micellar simulations.

High-pressure phase transitions - Examples of classical predictability

NASA Astrophysics Data System (ADS)

Celebonovic, Vladan

1992-09-01

The applicability of the Savic and Kasanin (1962-1967) classical theory of dense matter to laboratory experiments requiring estimates of high-pressure phase transitions was examined by determining phase transition pressures for a set of 19 chemical substances (including elements, hydrocarbons, metal oxides, and salts) for which experimental data were available. A comparison between experimental and transition points and those predicted by the Savic-Kasanin theory showed that the theory can be used for estimating values of transition pressures. The results also support conclusions obtained in previous astronomical applications of the Savic-Kasanin theory.

Determination of human body burden baseline date of platinum through autopsy tissue analysis.

PubMed Central

Vandiver, F; Duffield, F V; Yoakum, A; Bumgarner, J; Moran, J

1976-01-01

Results of analysis for platinum in 97 autopsy sets are presented. Analysis was performed by a specially developed emission spectrochemical method. Almost half of the individuals studied were found to have detectable platinum in one or more tissue samples. Platinum was found to be deposited in 13 of 21 tissue types investigated. Surprisingly high values were observed in subcutaneous fat, previously not considered to be a target site for platinum deposition. These data will serve as a human tissue platinum burden baseline in EPA's Catalyst Research Program. PMID:1001291

[Hard to accurately determine the age of children seeking asylum].

PubMed

Hjern, Anders; Ascher, Henry

2015-10-12

Many unaccompanied asylum seeking young people in Europe lack documents proving their age. X rays of the wrist and wisdom teeth are often used by European migration authorities to assess age in this situation. The large inter-individual differences in physical maturation during adolescence create such large margins of error for these methods that their informative value is very limited. The Swedish National Board of Health and Welfare should reconsider its previous position on these methods and examine the possibility to include psychosocial methods in these age assessment procedures.

Isotopic fingerprints of anthropogenic molybdenum in lake sediments.

PubMed

Chappaz, Anthony; Lyons, Timothy W; Gordon, Gwyneth W; Anbar, Ariel D

2012-10-16

We measured the molybdenum isotope compositions (δ(98)Mo) of well-dated sediment cores from two lakes in eastern Canada in an effort to distinguish between natural and anthropogenic contributions to these freshwater aquatic systems. Previously, Chappaz et al. (1) ascribed pronounced 20th-century Mo concentration enrichments in these lakes to anthropogenic inputs. δ(98)Mo values in the deeper sediments (reflecting predominantly natural Mo sources) differ dramatically between the two lakes: -0.32 ± 0.17‰ for oxic Lake Tantare and +0.64 ± 0.09‰ for anoxic Lake Vose. Sediment layers previously identified as enriched in anthropogenic Mo, however, reveal significant δ(98)Mo shifts of ± 0.3‰, resulting in isotopically heavier values of +0.05 ± 0.18‰ in Lake Tantare and lighter values of +0.31 ± 0.03‰ in Lake Vose. We argue that anthropogenic Mo modifies the isotopic composition of the recent sediments, and we determine δ(98)Mo(anthropogenic) values of 0.1 ± 0.1‰ (Lake Vose) and 0.2 ± 0.2‰ (Lake Tantare). These calculated inputs are consistent with the δ(98)Mo of molybdenite (MoS(2)) likely delivered to the lakes via smelting of porphyry copper deposits (Lake Vose) or through combustion of coal and oil also containing Mo (Lake Tantare). Our results confirm the utility of Mo isotopes as a promising fingerprint of human impacts and perhaps the specific sources of contamination. Importantly, the magnitudes of the anthropogenic inputs are large enough, relative to the natural Mo cycles in each lake, to have an impact on the microbiological communities.

Normal results of post-race thallium-201 myocardial perfusion imaging in marathon runners with elevated serum MB creatine kinase levels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siegel, A.J.; Silverman, L.M.; Holman, B.L.

1985-10-01

Elevated cardiac enzyme values in asymptomatic marathon runners after competition can arise from skeletal muscle through exertional rhabdomyolysis, silent injury to the myocardium, or a combined tissue source. Peak post-race levels of the MB isoenzyme of creatine kinase are similar to values in patients with acute myocardial infarction. Previously reported normal results of infarct-avid myocardial scintigraphy with technetium 99m pyrophosphate in runners after competition suggest a non-cardiac source but cannot exclude silent injury to the myocardium. Therefore, thallium 201 myocardial perfusion imaging was performed in runners immediately after competition together with determination of sequential cardiac enzyme levels. Among 15 runnersmore » tested, the average peak in serum MB creatine kinase 24 hours after the race was 128 IU/liter with a cumulative MB creatine kinase release of 117 IU/liter; these values are comparable to those in patients with acute transmural myocardial infarction. Thallium 201 myocardial scintigraphic results were normal in five runners randomly selected from those who volunteered for determination of sequential blood levels. It is concluded that elevations of serum MB creatine kinase in marathon runners arise from a skeletal muscle source and that thallium 201 myocardial scintigraphy is useful to assess runners for myocardial injury when clinical questions arise.« less

New methods for B meson decay constants and form factors from lattice NRQCD

DOE PAGES

Hughes, C.; Davies, C. T.H.; Monahan, C. J.

2018-03-20

We determine the normalization of scalar and pseudoscalar current operators made from nonrelativistic b quarks and highly improved staggered light quarks in lattice quantum chromodynamics (QCD) through O(α s) and Λ QCD/m b. We use matrix elements of these operators to extract B meson decay constants and form factors, and then compare to those obtained using the standard vector and axial-vector operators. This provides a test of systematic errors in the lattice QCD determination of the B meson decay constants and form factors. We provide a new value for the B and B s meson decay constants from lattice QCDmore » calculations on ensembles that include u, d, s, and c quarks in the sea and those that have the u/d quark mass going down to its physical value. Our results are f B=0.196(6) GeV, f Bs=0.236(7) GeV, and f Bs/f B=1.207(7), agreeing well with earlier results using the temporal axial current. By combining with these previous results, we provide updated values of f B=0.190(4) GeV, f Bs=0.229(5) GeV, and f Bs/f B=1.206(5).« less

The cost of a small membrane bioreactor.

PubMed

Lo, C H; McAdam, E; Judd, S

2015-01-01

The individual cost contributions to the mechanical components of a small membrane bioreactor (MBR) (100-2,500 m3/d flow capacity) are itemised and collated to generate overall capital and operating costs (CAPEX and OPEX) as a function of size. The outcomes are compared to those from previously published detailed cost studies provided for both very small containerised plants (<40 m3/day capacity) and larger municipal plants (2,200-19,000 m3/d). Cost curves, as a function of flow capacity, determined for OPEX, CAPEX and net present value (NPV) based on the heuristic data used indicate a logarithmic function for OPEX and a power-based one for the CAPEX. OPEX correlations were in good quantitative agreement with those reported in the literature. Disparities in the calculated CAPEX trend compared with reported data were attributed to differences in assumptions concerning cost contributions. More reasonable agreement was obtained with the reported membrane separation component CAPEX data from published studies. The heuristic approach taken appears appropriate for small-scale MBRs with minimal costs associated with installation. An overall relationship of net present value=(a tb)Q(-c lnt+d) was determined for the net present value where a=1.265, b=0.44, c=0.00385 and d=0.868 according to the dataset employed for the analysis.

Effects of delay and probability combinations on discounting in humans.

PubMed

Cox, David J; Dallery, Jesse

2016-10-01

To determine discount rates, researchers typically adjust the amount of an immediate or certain option relative to a delayed or uncertain option. Because this adjusting amount method can be relatively time consuming, researchers have developed more efficient procedures. One such procedure is a 5-trial adjusting delay procedure, which measures the delay at which an amount of money loses half of its value (e.g., $1000 is valued at $500 with a 10-year delay to its receipt). Experiment 1 (n=212) used 5-trial adjusting delay or probability tasks to measure delay discounting of losses, probabilistic gains, and probabilistic losses. Experiment 2 (n=98) assessed combined probabilistic and delayed alternatives. In both experiments, we compared results from 5-trial adjusting delay or probability tasks to traditional adjusting amount procedures. Results suggest both procedures produced similar rates of probability and delay discounting in six out of seven comparisons. A magnitude effect consistent with previous research was observed for probabilistic gains and losses, but not for delayed losses. Results also suggest that delay and probability interact to determine the value of money. Five-trial methods may allow researchers to assess discounting more efficiently as well as study more complex choice scenarios. Copyright © 2016 Elsevier B.V. All rights reserved.

Use of the Keele injector for sample introduction for gas chromatographic analysis of vinclozolin in lettuces.

PubMed

Shim, J H; Lee, Y S; Kim, M R; Lee, C J; Kim, I S

2003-10-10

We examined a Keele injector for sample introduction for gas chromatographic analysis of vinclozolin treated in lettuces. Samples in milligram quantity were introduced into a glass tube in a Keele injector at a gas chromatograph injection port. The glass tube was then crushed to allow the sample to carry onto a capillary column in a normal manner. The standard calibration curve for quantitative detection of vinclozolin was obtained by determining vinclozolin spiked in samples at variable concentrations. The calibration curve showed a linear response to vinclozolin ranging from 0.05 to 1.0 microg/g, giving a slope value of 174.8, the y-intercept value of -2.8146 and the mean r2-value of 0.9994. Limit of quantification for vinclozolin was 0.05 microg/g by this method, comparable to 0.01 microg/g by a normal injector. When samples treated previously with vinclozolin were determined by the Keele injector, vinclozolin was found to be about 30% lower as compared to a normal method, suggesting about 70% recovery of the spiked vinclozolin by the Keele injector. From these results, the Keele injector was suggested to be potential for sample introduction in gas chromatographic analysis of vinclozolin in lettuce samples.

Biomonitoring of 33 Elements in Blood and Urine Samples from Coastal Populations in Sanmen County of Zhejiang Province.

PubMed

Zhang, Su-jing; Luo, Ru-xin; Ma, Dong; Zhuo, Xian-yi

2016-04-01

To determine the normal reference values of 33 elements, Ag, Al, As, Au, B, Ba, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Hg, Li, Mg, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, Th, Ti, Tl, U, V, Zn and Zr, in the blood and urine samples from the general population in Sanmen County of Zhejiang province, a typical coastal area of eastern China. The 33 elements in 272 blood and 300 urine samples were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The normality test of data was conducted using SPSS 17.0 Statistics. The data was compared with other reports. The normal reference values of the 33 elements in the blood and urine samples from the general population in Sanmen County were obtained, which of some elements were found to be similar with other reports, such as Co, Cu, Mn and Sr, while As, Cd, Hg and Pb were generally found to be higher than those previously reported. There was a wide variation between the reports from different countries in blood Ba. The normal reference values of the 33 elements in the blood and urine samples from the general population in Sanmen County are established, and successfully applied to two poisoning cases.

New methods for B meson decay constants and form factors from lattice NRQCD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hughes, C.; Davies, C. T.H.; Monahan, C. J.

We determine the normalization of scalar and pseudoscalar current operators made from nonrelativistic b quarks and highly improved staggered light quarks in lattice quantum chromodynamics (QCD) through O(α s) and Λ QCD/m b. We use matrix elements of these operators to extract B meson decay constants and form factors, and then compare to those obtained using the standard vector and axial-vector operators. This provides a test of systematic errors in the lattice QCD determination of the B meson decay constants and form factors. We provide a new value for the B and B s meson decay constants from lattice QCDmore » calculations on ensembles that include u, d, s, and c quarks in the sea and those that have the u/d quark mass going down to its physical value. Our results are f B=0.196(6) GeV, f Bs=0.236(7) GeV, and f Bs/f B=1.207(7), agreeing well with earlier results using the temporal axial current. By combining with these previous results, we provide updated values of f B=0.190(4) GeV, f Bs=0.229(5) GeV, and f Bs/f B=1.206(5).« less

Diphasic acido-basic properties of D(octylphenyl)phosphoric acid (DOPPA)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sella, C.; Cote, G.; Bauer, D.

1995-07-01

In the first part of this work, the diphasic acido-basic constant (pka*) of di(octylphenyl)phosphoric acid, denoted hereafter DOPPA or HL, is determined from its experimental diphasic neutralization curve. The pka* value of DOPPA appears to be equal to 2.6 in the presence of 1 mol/dm{sup 3} sodium salt. Such a value is significantly lower than that previously determined for di(2-ethylhexyl) phosphoric acid (DEHPA, pka* = 5.2), 2-ethylhexylphosphonic acid, mono-2-ethylhexyl ester (PC88A, pka* = 7.1) and di(2,4,4-trimethylpentyl)phosphinic acid (CYANEX 272, pka* = 8.7). DOPPA (HL) is definitely more acidic than the other organophosphorus acids because its acidic proton can be easilymore » exchanged with sodium cation to form Na{sup +}HL{sub 2}{sup -} species in organic phase. In the second and final part of the work, molecular modelling is used to model the dimers of various organophosphorus acids. A structure-activity relationship is obtained between the association energies of modelled dimers and their diphasic acido-basic constants. This relationship is then used for predicting the pka* values of DOPPOA and DOPPIA which are the phosphonic and phosphinic analogs of DOPPA, respectively. 16 refs., 5 figs., 4 tabs.« less

Triprotic site-specific acid-base equilibria and related properties of fluoroquinolone antibacterials.

PubMed

Rusu, Aura; Tóth, Gergő; Szőcs, Levente; Kökösi, József; Kraszni, Márta; Gyéresi, Árpád; Noszál, Béla

2012-07-01

The complete macro- and microequilibrium analyses of six fluoroquinolone drugs - ciprofloxacin, enrofloxacin, norfloxacin, pefloxacin, ofloxacin and moxifloxacin - are presented. Previous controversial literature data are straightened up, the protonation centers are unambiguously identified, and the protonation macro- and microconstant values are reported. The macroconstants were determined by (1)H NMR-pH titrations while the microconstants were determined by a multi-modal spectroscopic-deductive methodology, in which methyl ester derivatives were synthesized and their NMR-pH titration data contributed to the evaluation of all the microconstants. The full (1)H, (13)C and (15)N NMR assignments, NMR-pH profiles, macro- and microprotonation schemes and species-specific diagrams are included. Our studies show that the fluoroquinolones have three protonation centers: the carboxylate group, the N-1' and N-4' piperazine nitrogens and concentration of the uncharged microspecies is way below the values published earlier. The results could be well interpreted in terms of structural properties. The protonation macro- and microconstant values allow the pre-planned method development in techniques such as capillary zone electrophoresis and also, the interpretation of fluoroquinolone mechanism of biological action, including the pharmacokinetic properties, and antibacterial activities that are all heavily influenced by the states of protonation. Copyright © 2012 Elsevier B.V. All rights reserved.

Normal range of human dietary sodium intake: a perspective based on 24-hour urinary sodium excretion worldwide.

PubMed

McCarron, David A; Kazaks, Alexandra G; Geerling, Joel C; Stern, Judith S; Graudal, Niels A

2013-10-01

The recommendation to restrict dietary sodium for management of hypertensive cardiovascular disease assumes that sodium intake exceeds physiologic need, that it can be significantly reduced, and that the reduction can be maintained over time. In contrast, neuroscientists have identified neural circuits in vertebrate animals that regulate sodium appetite within a narrow physiologic range. This study further validates our previous report that sodium intake, consistent with the neuroscience, tracks within a narrow range, consistent over time and across cultures. Peer-reviewed publications reporting 24-hour urinary sodium excretion (UNaV) in a defined population that were not included in our 2009 publication were identified from the medical literature. These datasets were combined with those in our previous report of worldwide dietary sodium consumption. The new data included 129 surveys, representing 50,060 participants. The mean value and range of 24-hour UNaV in each of these datasets were within 1 SD of our previous estimate. The combined mean and normal range of sodium intake of the 129 datasets were nearly identical to that we previously reported (mean = 158.3±22.5 vs. 162.4±22.4 mmol/d). Merging the previous and new datasets (n = 190) yielded sodium consumption of 159.4±22.3 mmol/d (range = 114-210 mmol/d; 2,622-4,830mg/d). Human sodium intake, as defined by 24-hour UNaV, is characterized by a narrow range that is remarkably reproducible over at least 5 decades and across 45 countries. As documented here, this range is determined by physiologic needs rather than environmental factors. Future guidelines should be based on this biologically determined range.

Curve Number Application in Continuous Runoff Models: An Exercise in Futility?

NASA Astrophysics Data System (ADS)

Lamont, S. J.; Eli, R. N.

2006-12-01

The suitability of applying the NRCS (Natural Resource Conservation Service) Curve Number (CN) to continuous runoff prediction is examined by studying the dependence of CN on several hydrologic variables in the context of a complex nonlinear hydrologic model. The continuous watershed model Hydrologic Simulation Program-FORTRAN (HSPF) was employed using a simple theoretical watershed in two numerical procedures designed to investigate the influence of soil type, soil depth, storm depth, storm distribution, and initial abstraction ratio value on the calculated CN value. This study stems from a concurrent project involving the design of a hydrologic modeling system to support the Cumulative Hydrologic Impact Assessments (CHIA) of over 230 coal-mined watersheds throughout West Virginia. Because of the large number of watersheds and limited availability of data necessary for HSPF calibration, it was initially proposed that predetermined CN values be used as a surrogate for those HSPF parameters controlling direct runoff. A soil physics model was developed to relate CN values to those HSPF parameters governing soil moisture content and infiltration behavior, with the remaining HSPF parameters being adopted from previous calibrations on real watersheds. A numerical procedure was then adopted to back-calculate CN values from the theoretical watershed using antecedent moisture conditions equivalent to the NRCS Antecedent Runoff Condition (ARC) II. This procedure used the direct runoff produced from a cyclic synthetic storm event time series input to HSPF. A second numerical method of CN determination, using real time series rainfall data, was used to provide a comparison to those CN values determined using the synthetic storm event time series. It was determined that the calculated CN values resulting from both numerical methods demonstrated a nonlinear dependence on all of the computational variables listed above. It was concluded that the use of the Curve Number as a surrogate for the selected subset of HPSF parameters could not be justified. These results suggest that use of the Curve Number in other complex continuous time series hydrologic models may not be appropriate, given the limitations inherent in the definition of the NRCS CN method.

Quantification of elemental area densities in multiple metal layers (Au/Ni/Cu) on a Cr-coated quartz glass substrate for certification of NMIJ CRM 5208-a.

PubMed

Ariga, Tomoko; Zhu, Yanbei; Ito, Mika; Takatsuka, Toshiko; Terauchi, Shinya; Kurokawa, Akira; Inagaki, Kazumi

2018-04-01

Area densities of Au/Ni/Cu layers on a Cr-coated quartz substrate were characterized to certify a multiple-metal-layer certified reference material (NMIJ CRM5208-a) that is intended for use in the analysis of the layer area density and the thickness by an X-ray fluorescence spectrometer. The area densities of Au/Ni/Cu layers were calculated from layer mass amounts and area. The layer mass amounts were determined by using wet chemical analyses, namely inductively coupled plasma mass spectrometry (ICP-MS), isotope-dilution (ID-) ICP-MS, and inductively coupled plasma optical emission spectrometry (ICP-OES) after dissolving the layers with diluted mixture of HCl and HNO 3 (1:1, v/v). Analytical results of the layer mass amounts obtained by the methods agreed well with each another within their uncertainty ranges. The area of the layer was determined by using a high-resolution optical scanner calibrated by Japan Calibration Service System (JCSS) standard scales. The property values of area density were 1.84 ± 0.05 μg/mm 2 for Au, 8.69 ± 0.17 μg/mm 2 for Ni, and 8.80 ± 0.14 μg/mm 2 for Cu (mean ± expanded uncertainty, coverage factor k = 2). In order to assess the reliability of these values, the density of each metal layer calculated from the property values of the area density and layer thickness measured by using a scanning electron microscope were compared with available literature values and good agreement between the observed values and values obtained in previous studies.

Carbon stable isotope composition of DNA isolated from an incipient paleosol

NASA Astrophysics Data System (ADS)

Jahren, A. Hope; Kelm, Kellie; Wendland, Beverly; Petersen, Gitte; Seberg, Ole

2006-05-01

We determined the carbon isotope (δ13C) value of double-stranded DNA (dsDNA) isolated from the organic horizons of a Delaware soil that is actively being covered by an encroaching sand dune. The soil belongs to a Nymphaea odorata Ait. (water lily) wetland, and we regard its active acquisition of a thick (˜24 cm) surface mantle to embody the process of paleopedogenesis; therefore, we have termed it an “incipient paleosol.” In this study, we compared the δ13C value of paleosol dsDNA to the bulk δ13C value of N. odorata, as well as to the δ13C value of plants that had colonized the surface mantle. The isotopic offset between paleosol δ13CdsDNA and N. odorata δ13Ctissue was identical to the relationship between δ13CdsDNA and δ13Ctissue for tracheophytes, which we had previously determined. In contrast, the isotopic offset between paleosol δ13CdsDNA and the δ13Ctissue of plants colonizing the surface mantle differed from this relationship by as much as 4‰. Similarly, the δ13C value of bulk paleosol organic matter was extremely heterogeneous and varied across 6‰. All paleosol DNA polymerase chain reaction (PCR) products produced clear, sharp, 350 base-pair (bp) fragments of rbcL, a gene shared by all photosynthetic organisms. These results open the exciting possibility that stable isotope analysis of dsDNA isolated from paleosol organic matter can be used to infer the δ13C value of the plant that dominated the nucleic acid contribution.

Use of isotopic sulfur to determine whitebark pine consumption by Yellowstone bears: a reassessment

USGS Publications Warehouse

Schwartz, Charles C.; Teisberg, Justin E.; Fortin, Jennifer K.; Haroldson, Mark A.; Servheen, Christopher; Robbins, Charles T.; van Manen, Frank T.

2014-01-01

Use of naturally occurring stable isotopes to estimate assimilated diet of bears is one of the single greatest breakthroughs in nutritional ecology during the past 20 years. Previous research in the Greater Yellowstone Ecosystem (GYE), USA, established a positive relationship between the stable isotope of sulfur (δ34S) and consumption of whitebark pine (Pinus albicaulis) seeds. That work combined a limited sample of hair, blood clots, and serum. Here we use a much larger sample to reassess those findings. We contrasted δ34S values in spring hair and serum with abundance of seeds of whitebark pine in samples collected from grizzly (Ursus arctos) and American black bears (U. americanus) in the GYE during 2000–2010. Although we found a positive relationship between δ34S values in spring hair and pine seed abundance for grizzly bears, the coefficients of determination were small (R2 ≤ 0.097); we failed to find a similar relationship with black bears. Values of δ34S in spring hair were larger in black bears and δ34S values in serum of grizzly bears were lowest in September and October, a time when we expect δ34S to peak if whitebark pine seeds were the sole source of high δ34S. The relationship between δ34S in bear tissue and the consumption of whitebark pine seeds, as originally reported, may not be as clean a method as proposed. Data we present here suggest other foods have high values of δ34S, and there is spatial heterogeneity affecting the δ34S values in whitebark pine, which must be addressed.

Semi-automated and automated glioma grading using dynamic susceptibility-weighted contrast-enhanced perfusion MRI relative cerebral blood volume measurements.

PubMed

Friedman, S N; Bambrough, P J; Kotsarini, C; Khandanpour, N; Hoggard, N

2012-12-01

Despite the established role of MRI in the diagnosis of brain tumours, histopathological assessment remains the clinically used technique, especially for the glioma group. Relative cerebral blood volume (rCBV) is a dynamic susceptibility-weighted contrast-enhanced perfusion MRI parameter that has been shown to correlate to tumour grade, but assessment requires a specialist and is time consuming. We developed analysis software to determine glioma gradings from perfusion rCBV scans in a manner that is quick, easy and does not require a specialist operator. MRI perfusion data from 47 patients with different histopathological grades of glioma were analysed with custom-designed software. Semi-automated analysis was performed with a specialist and non-specialist operator separately determining the maximum rCBV value corresponding to the tumour. Automated histogram analysis was performed by calculating the mean, standard deviation, median, mode, skewness and kurtosis of rCBV values. All values were compared with the histopathologically assessed tumour grade. A strong correlation between specialist and non-specialist observer measurements was found. Significantly different values were obtained between tumour grades using both semi-automated and automated techniques, consistent with previous results. The raw (unnormalised) data single-pixel maximum rCBV semi-automated analysis value had the strongest correlation with glioma grade. Standard deviation of the raw data had the strongest correlation of the automated analysis. Semi-automated calculation of raw maximum rCBV value was the best indicator of tumour grade and does not require a specialist operator. Both semi-automated and automated MRI perfusion techniques provide viable non-invasive alternatives to biopsy for glioma tumour grading.

Patient doses from fluoroscopically guided cardiac procedures in pediatrics

NASA Astrophysics Data System (ADS)

Martinez, L. C.; Vano, E.; Gutierrez, F.; Rodriguez, C.; Gilarranz, R.; Manzanas, M. J.

2007-08-01

Infants and children are a higher risk population for radiation cancer induction compared to adults. Although some values on pediatric patient doses for cardiac procedures have been reported, data to determine reference levels are scarce, especially when compared to those available for adults in diagnostic and therapeutic procedures. The aim of this study is to make a new contribution to the scarce published data in pediatric cardiac procedures and help in the determination of future dose reference levels. This paper presents a set of patient dose values, in terms of air kerma area product (KAP) and entrance surface air kerma (ESAK), measured in a pediatric cardiac catheterization laboratory equipped with a biplane x-ray system with dynamic flat panel detectors. Cardiologists were properly trained in radiation protection. The study includes 137 patients aged between 10 days and 16 years who underwent diagnostic catheterizations or therapeutic procedures. Demographic data and technical details of the procedures were also gathered. The x-ray system was submitted to a quality control programme, including the calibration of the transmission ionization chamber. The age distribution of the patients was 47 for <1 year; 52 for 1-<5 years; 25 for 5-<10 years and 13 for 10-<16 years. Median values of KAP were 1.9, 2.9, 4.5 and 15.4 Gy cm2 respectively for the four age bands. These KAP values increase by a factor of 8 when moving through the four age bands. The probability of a fatal cancer per fluoroscopically guided cardiac procedure is about 0.07%. Median values of ESAK for the four age bands were 46, 50, 56 and 163 mGy, which lie far below the threshold for deterministic effects on the skin. These dose values are lower than those published in previous papers.